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Biomedical subjects

G Blake

Publications and source records attributed to G Blake.

At least 19 recordsLinked to original sources
PubMed2007

Does adjuvant alpha-interferon improve outcome when combined with total skin irradiation for mycosis fungoides?

BACKGROUND: Patients with mycosis fungoides (MF) experience frequent disease recurrences following total skin electron irradiation (TSEI) and may benefit from adjuvant therapy. OBJECTIVES: To review the McGill experience with adjuvant alpha-interferon (IFN) in the treatment of MF. METHODS: From 1990 to 2000, 50 patients with MF were treated with TSEI: 31 with TSEI alone and 19 with TSEI + IFN. Median TSEI dose was 35 Gy. In the TSEI + IFN group, IFN was given subcutaneously at 3 x 10(6) units three times per week starting 2 weeks prior to start of TSEI, continued concurrently with the radiation and for an additional 12 months following TSEI. The TSEI alone group included 16 men and 15 women with a median age of 61 years (range 31-84). The TSEI + IFN group included 14 men and five women with a median age of 51 years (range 24-83). Clinical stage was IA, IB, IIA, IIB, III and IVA in 2, 9, 4, 8, 1 and 7 patients of the TSEI group and 0, 3, 3, 7, 4 and 2 patients of the TSEI + IFN group. RESULTS: Median follow up for living patients was 70 months. All patients responded to treatment. Complete response (CR) rate was 65% following TSEI and 58% following TSEI + IFN (P = 0.6). Median overall survival (OS) was 61 months following TSEI and 38 months following TSEI + IFN (P = 0.4). Acute grade II-III dermatitis was seen in all patients. Fever, chills or myalgia were seen in 32% of patients treated with TSEI + IFN. CONCLUSIONS: Concurrent IFN and TSEI is feasible, with acceptable toxicity. Even when controlling for disease stage, the addition of IFN did not appear to increase CR rate, disease-free survival or OS.

Adult↗
PubMed2006

[Analysis and speciation of metals in sediments of an artificial water reserve in a mining zone the case of Guenitra Dam, Algeria].

The distribution of Cd, Pb, Zn, Mn and Fe was studied in the sediments of Guenitra reservoir located in a mining zone in the northeast of Algeria. An analytical procedure involving sequential chemical extractions was used for the partitioning of metals in the fractions: exchangeable, bound to carbonates, bound to iron and manganese hydroxides, bound to organic matter and bound to mineral structures. Experimental results obtained, show that the metals investigated are distributed in all the compartments of the sediments. Except for iron, the quantity of each metal associated with the available fractions exceeded 70% of the total quantity. Cd and Zn mostly occurred in the oxidisable fraction and the hydroxide bound fraction dominated in the case of Pb.

Algeria↗
PubMed2006

Trends in incidence and histological subtypes of lung cancer, Kingston and St Andrew, Jamaica, 1968-1997.

Several scientific publications have reported a progressive shift in the distribution of the histologic subtypes of lung carcinoma in the latter decades of the 20th century, with adenocarcinoma now surpassing squamous cell carcinoma as the most commonly diagnosed morphologic pattern. A 30-year review (1968-1997) of lung cancer cases registered in the Jamaica cancer registry shows a similar trend among males in Kingston and St Andrew with a progressive increase in the documented cases of adenocarcinoma relative to squamous cell carcinoma. Similar changes were not observed in females.

Adenocarcinoma↗
PubMed2005

Deep Impact: observations from a worldwide Earth-based campaign.

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

Cosmic Dust↗
PubMed2003

Gynaecologic cancer incidence, Kingston and St Andrew, Jamaica, 1973-1997, and gynaecologic cancer mortality, Jamaica, 1999.

The incidence of gynaecologic cancers in women from Kingston and St Andrew for the period 1973-1997 were reviewed by analyzing data previously published by the Jamaica Cancer Registry. Gynaecologic cancer-related mortality statistics for the entire island for 1999 were compiled from data obtained from the Registrar General's Department (RGD) and the Statistical Institute of Jamaica (STATIN). Data were compared to gynaecologic cancer statistics for women from the United States of America for 1973-1997. A total of 2862 gynaecologic cancers were registered for the years 1973-1997, which represents 26.8% of all female cancers from Kingston and St Andrew. Cervical cancer accounted for 62% of these gynaecologic cancers. The 268 cancer-related deaths (168 due to cervical cancer) registered in Jamaican women for 1999 represent approximately 15% of all female cancer-related deaths. The present incidence (27.9 per 100,000) and mortality rate (15.8 per 100,000) of cervical cancer are much higher than that documented for American women--both African Americans and Caucasians--and signify the limited success, to date, of efforts to decrease the incidence and mortality of cervical cancer by the implementation of cervical cancer screening programmes. For the time period reviewed, an increase was noted in the incidence of cancer of the corpus uteri while decreases were recorded for the incidence of choriocarcinoma, ovarian cancer and cancers arising from the vulva, vagina and fallopian tube.

Age Factors↗
PubMed2002

Jamaica cancer mortality statistics, 1999.

A total of 2697 cancer-related deaths were documented among Jamaicans for the year 1999, accounting for 17.7% of all deaths. Males accounted for 1466 and females for 1231. The age-adjusted cancer mortality rate was 171.7 per 100,000 for males, 122.0 per 100,000 for females and 140.5 per 100,000 for the total population. Leading cancer mortality sites for males were prostate, lung and stomach and in females, breast, cervix uteri and large bowel. Most deaths were recorded in the 55-64 and 65-74 year-age groups. Despite well-established cervical cancer screening programmes, the calculated mortality rate for cancer of the cervix uteri in Jamaican females (15.8 per 100,000) is approximately two and a half times that seen in African-American females.

Adult↗
PubMed2001

Biodegradation of anthracene and fluoranthene by fungi isolated from an experimental constructed wetland for wastewater treatment.

Pilot-scale constructed wetlands were used to treat water contaminated by polycyclic aromatic hydrocarbons (PAHs), particularly fluoranthene, and the possible role of fungi present in these ecosystems was investigated. A total of 40 fungal species (24 genera) were isolated and identified from samples (gravel and sediments) from a contaminated wetland and a control wetland. All of them were assayed for their ability to remove anthracene (AC) and fluoranthene (FA) from liquid medium. FA was degraded efficiently by 33 species while only 2 species were able to remove AC over 70%. A selection of 10 strains of micromycetes belonging to various taxonomic groups was further investigated for FA and AC degradation, toxicity assays and phenoloxidases (POx) detection. Interesting and not previously reported species were revealed (Absidia cylindrospora, Cladosporium sphaerospermum, and Ulocladium chartarum). They were all able to highly degrade the PAH-model compounds chosen. An interesting inducibility was noted for Ulocladium chartarum. Degradative ability of fungi was not related to their extracellular POx activity. This study may contribute to the improvement of constructed wetlands for water treatment, which may be enriched in efficient fungi.

Anthracenes↗
PubMed2001

Single and combined effects of sediment-associated PAHs on three species of freshwater macroinvertebrates.

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous pollutants of sediments. Sediment quality criteria often use toxicity data for individual PAHs. However, PAHs always occur in field sediments as a complex mixture of compounds. In this study, the toxicity of phenanthrene (P), fluoranthene (FLA) and benzo(k)-fluoranthene (B), alone or in combination, was assessed using monospecific sediment tests of acute toxicity (between 24 h and 14 days). The test sediments were spiked formulated sediments. Toxicity of PAHs was determined on a freshwater pelagic organism, Daphnia magna, on an epibenthic organism, Hyalella azteca, and on a benthic organism, Chironomus riparius. The phototoxicity of fluoranthene and phenanthrene was verified. Benzo(k)fluoranthene was not phototoxic and presented no toxicity for the three organisms tested up to 300 mg/kg, concentration rarely found in the environment. For all PAHs, the toxicity towards Daphnia magna was two-fold higher in the sediment toxicity tests than in the water-only standard tests, probably due to suspended contaminated particles and contact of daphnids with sediment. For phenanthrene, the LC50s found were 50, 15 and 20 mg/kg dry weight sediment, respectively for Daphnia magna, Hyalella azteca and Chironomus riparius. The bioassays on fluoranthene yielded LC50s of 10, 5 and 15 mg/kg dw respectively for Daphnia magna, Hyalella azteca and Chironomus riparius. LC50s of the PAHs mixture (1/3 of each compound by weight) were around 10 mg/kg dry weight sediment for Hyalella azteca and 20 mg/kg for Chironomus riparius. The effects of PAHs in the mixture seemed to be synergistic. This study gives new data about PAH toxicity and showed that the additivity of PAH effects could be inadequate to assess the environmental risk.

Animals↗
PubMed2001

Age-specific incidence of cancer in Kingston and St Andrew, Jamaica, 1993-1997.

A total of 4285 malignant neoplasms were recorded in Kingston and St. Andrew during the period 1993-1997, 2344 in females and 1941 in males. The crude incidence rate per 100,000 (CIR) for males was 121.6 and for females 129.2. Age standardized rates per 100,000 (ASR) were 156.7 and 176.7 for males and females respectively. In males, the leading sites for cancer were prostate (619 cases), bronchus (265 cases) and large bowel (144 cases) while in females the leading sites were breast (627 cases) cervix uteri (376 cases) and large bowel (204 cases). The crude and age standardized incidence rates have remained stable as compared to those for the previous five year period (1998-1992). The leading sites for both males and females have also been maintained in the same order but there was a marked increase in prostate cancer (ASR 56.4 versus 36). Invasive cervical cancer has shown no significant change in incidence (ASR 25.2 versus 26.3) but the rate for in-situ cancers has decreased (ASR 27.4 versus 43.8). The incidence of cancer of the female breast has remained relatively stable (ASR 43.2 versus 47.1). The trends exhibited by both prostate cancer and in-situ cervical cancer probably represent the influence of screening methods for prostate cancer and ablative management for low grade dysplastic lesions of the cervix uteri respectively.

Adult↗
PubMed2001

Design and performance of experimental constructed wetlands treating coke plant effluents.

Reed beds were chosen to treat effluents from a coke plant in France (Usinor-Sollac, Fos/mer). The pilot is composed by a two-stage gravel bed with subsurface flow and Phragmites australis as plant. This experimental constructed wetland was monitored for one year at steady-state conditions. The composition of influent shows high concentrations of organic compounds. The hydraulic residence time was close to 10-12 days with a plug flow with longitudinal dispersion. Results show that global removal of nitrogen ranged from 54 to 94% of load removal efficiency, but corresponds easily to the regulation recommendations. Because of wintertime, the denitrification process was inhibited by aerobic conditions observed in the gravel bed with oxygen concentrations higher than 2-3 mg/L, and by small amounts of biodegradable carbon. The fate of mineral pollutants are linked to the complex ferric hydroxides balance and a lack of phosphorus was observed for reed plants, as this nutrient is dependent on iron compounds. Some necrosis was observed on plant tissues corresponding with anthocyanic pigments accumulation caused by phosphorus absorption deficiency due to its co-precipitation with iron.

Coke↗
PubMed2000

Tumour necrosis factor-alpha (TNF-alpha) enhances lymphocyte migration into rheumatoid synovial tissue transplanted into severe combined immunodeficient (SCID) mice.

Adhesion mechanisms play a major role in the recruitment of peripheral blood lymphocytes (PBL) which characteristically infiltrate rheumatoid arthritis (RA) synovium and other chronically inflamed tissues. Through a sequential series of complex integrated adhesion and signalling events, 'multistep model of migration', specific subsets of PBL are recruited into inflamed tissues. In this process both leucocyte receptors and microvascular endothelial (MVE) counter-receptors play a critical role. The MVE in particular, during an inflammatory state, is the target of various inflammatory mediators that cause the up-regulation of several cell adhesion molecules (CAM). One of the most important factors known to be a powerful inducer of MVE CAM is TNF-alpha. Conversely, blocking TNF-alpha causes a down-modulation of CAM expression. To test directly the capacity of TNF-alpha to induce cell migration into RA synovium we adapted a model in which synovial grafts were implanted into SCID mice subcutaneously. Using this model we demonstrate that: (i) transplants remain viable and become vascularized and fed by mouse subdermal vessels; (ii) the mouse vasculature connects to the transplant vasculature which maintains the ability to express human CAM; (iii) intragraft injections of TNF-alpha up-regulate the expression of human CAM, following the down-regulation which occurred 4 weeks post-transplantation; and (iv) the up-regulation of graft CAM is associated with increased human PBL migration into the transplants. This study provides direct evidence in vivo of the capacity of TNF-alpha to induce cell migration. In addition, it provides the experimental background for the optimal use of this model.

Animals↗
PubMed1999

Radiation dose to the patient and operator from a peripheral dual X-ray absorptiometry system.

Although peripheral dual X-ray absorptiometry (pDXA) scanners for measuring bone mineral density (BMD) in the forearm are known to produce an exceptionally low radiation dose to the patient, quantitative assessment of patient dose from pDXA procedures is important for reassuring patients about their safety. We have estimated the effective dose of radiation (ICRP-60) to the patient and also the scattered dose to the operator from a forearm BMD examination performed on a DTX-200 pDXA system (Osteometer Meditech, Hoersholm, Denmark). Measurements were performed using thermoluminescent dosimeters (TLD's) attached to the forearm phantom supplied by the manufacturer. The effective dose to a patient was estimated to be 0.1 microSv. At a distance of 1 m from the center of the forearm, the time-averaged scattered dose to the operator assuming scanning five patients per hour was measured to be <0.1 microSv/h. The dose rate over the outside surface of the DTX-200 in line with the primary X-ray beam was measured to be 1.4 microSv/h. These figures compare with a natural background radiation in the United Kingdom of 7 microSv/d. In conclusion the radiation doses from forearm pDXA to both patients and operator were found to be truly trivial.

Absorptiometry, Photon↗