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Biomedical subjects

J Seres

Publications and source records attributed to J Seres.

9 recordsLinked to original sources
PubMed2005

Laser technology: source of coherent kiloelectronvolt X-rays.

Generating X-rays that have the properties of laser light has been a long-standing goal for experimental science. Here we describe the emission of highly collimated, spatially coherent X-rays, at a wavelength of about 1 nanometre and at photon energies extending to 1.3 kiloelectronvolts, from atoms that have been ionized by a 5-femtosecond laser pulse. This means that a laboratory source of laser-like, kiloelectronvolt X-rays, which will operate on timescales relevant to many chemical, biological and materials problems, is now within reach.

Journal Article↗
PubMed2003

Differences in hormonal and inflammatory parameters in male Lewis and Long Evans rats with adjuvant arthritis.

The purpose of the present study was (i) to compare secretory responses of prolactin and corticosterone to the acute stress of immobilization in male rats of the Lewis and Long Evans strains and (ii) to compare secretion of the two hormones in rats with fully developed adjuvant arthritis (AA) and their relationship with the intensity of the inflammatory reaction. A short immobilization of 5 min induced equal elevations of both hormones in both strains, but 20-min immobilization produced significantly stronger responses in Long Evans rats than in Lewis rats. AA inhibited prolactin secretion equally in both strains (from 11.6 +/- 1.3 ng/ml to 4.2 +/- 0.6 ng/ml in Lewis rats, p < 0.01, and from 3.7 +/- 0.6 to 2.12 +/- 0.1 ng/ml in Long Evans rats, p < 0.05), but caused a conspiciously larger elevation of corticosterone in the Long Evans than in the Lewis animals (11.5 +/- 1.2 microg/dl in Long Evans rats versus 5.1 +/- 0.5 microg/dl in Lewis rats, p < 0.01) while basal levels were similar. The larger corticosterone response in the Long Evans rats was associated with a stronger inflammatory reaction assessed by hind paw swelling (2.3 +/- 0.1 ml for Long Evans rats versus 1.8 +/- 0.08 ml for Lewis rats, p < 0.01) and plasma levels of nitric oxide (47.5 +/- 5.7 microM for Long Evans rats versus 28.7 +/- 2.5 microM for Lewis rats, p < 0.01) than in the Lewis males with lower corticosterone levels. In conclusion, there are significant, obviously genetically based, differences in the corticosterone responses to both immobilization and AA between the two strains, with the Long Evans rats reacting more strongly than the Lewis rats. The lack of the expected inverse relationship between corticosterone levels and the intensity of the inflammation indicates that the activity of corticosterone is not its primary determinant and that other important factors are involved.

Animals↗
PubMed2002

Effects of chronic food restriction stress and chronic psychological stress on the development of adjuvant arthritis in male long evans rats.

The aim of the present experiments was to study the effect of stress of chronic food restriction (FR) and of repeated psychological challenge (PS) on the development of adjuvant arthritis in the Long Evans male rats. In the FR series, four groups of animals were compared: non-treated control (C) and arthritic (AA) rats, both with free access to food and water, and two analogous groups with a 40% food restriction-FR and AA-FR. All animals were killed 22 days after injection of cFA. In the PS series, stress was induced by random daily exposures of the rats to isolation, over-crowding, food/water deprivation, foot shock, tilting, fear for 14 days before cFA injection and 12 days thereafter (groups: C, AA, PS, and AA-PS). Arthritis causes swelling of the hindpaw, which was prevented in the AA-FR group. PS causes more severe disease symptoms: AA-PS rats had more severe hindpaw swelling than AA rats. Forty percent food restriction associated with elevated CORT levels mitigated inflammatory parameters activated during AA. PS worsened the disease. These results suggested that activated CORT is not the only cause of disease suppression, but some metabolic changes during FR play a role.

Animals↗
PubMed1989

Pericardial effusion as a clinical sign of Legionnaires' disease.

Legionnella often causes systemic manifestations. The clinical spectrum now includes cardiac legionnellosis. The first case of pericardial effusion was reported in September, 1981. To date, few additional cases have been reported. We hereby report a case of asymptomatic pericardial effusion with simultaneous pulmonary involvement. Pericardial involvement, if sought, would probably be more frequent than supposed in Legionnaires' disease.

Electrocardiography↗
PubMed1977

[Synthesis and properties of bromocriptine (author's transl)].

The bromination of alpha-ergokryptine, a genuine ergot alkaloid of the peptide type, in position 2 of the indol nucleus to 2-bromo-alpha-ergokryptine is described. Its transformation to the methanesulfonate led to the prolactin inhibitor bromocriptine-methanesulfonate, Parlodel.

Bromocriptine↗
PubMedDate not supplied

The effects of a supervised toothbrushing programme on the caries increment of primary school children, initially aged 5-6 years.

Children in the London Boroughs of Kensington, Chelsea and Westminster have one of the highest levels of caries in England and Wales. In 1997/98, the mean dmft for 5-year-old children was 2.83 with only 45.9% of the children being caries free. The aim of this study was to determine whether teacher-supervised toothbrushing, once a day, at school, during term time, with commercial toothpaste containing 1,450 ppm fluoride, could reduce dental caries in primary school children when compared with children from the same community who did not receive this intervention. A total of 517 children (mean age 5.63 years) were recruited for the study. Class teachers were trained individually by the same dental hygienist in an appropriate toothbrushing technique for young children. Children in the intervention group brushed once a day at school. All examinations were by visual assessment only. All teeth present were assessed using the BASCD criteria. For children in the intervention group, the overall caries increment (2.60) was significantly less (10.9%; p < 0.001) than for children in the non-intervention group (2.92). Among different tooth surfaces, the difference in caries increment between the intervention group (0.78) and the non-intervention group (1.03) was greatest for the proximal surfaces (21.4%; p < 0.01). In conclusion, this study suggests that a programme of daily teacher-supervised toothbrushing with fluoride toothpaste can be effectively targeted into socially deprived communities and a significant reduction in dental caries can thereby be achieved especially among caries-susceptible children.

Cariostatic Agents↗
PubMedDate not supplied

Stress of chronic food restriction attenuates the development of adjuvant arthritis in male Long Evans rats.

OBJECTIVE: To study the effect of the stress of chronic food restriction on the development of adjuvant arthritis in Long Evans male rats. METHODS: Four groups of animals were compared: non-treated control (C) and arthritic (AA) rats, both with free access to food and water and two analogous groups with a 40% food restriction, i.e. non-treated (FR) and arthritic (AA-FR) animals. All rats were killed 22 days following the injection of complete Freund's adjuvant. The parameters measured were: serum levels of albumin (ALB), nitrate, glucose, insulin, corticosterone (CORT), prolactin (PRL) and PRL mRNA in the adenopituitaries. In addition the activity of gamma-glutamyl transpeptidase (GGTP) was measured in the spleen. The pain threshold was determined by the tailflick method. The body weight of the animals was recorded on day 0, 3, 7, 11, 15 and 18 of the disease. RESULTS: Arthritis caused swelling of the hind paw (2.37 +/- 0.15 ml vs 1.1 +/- 0.05ml in controls, p < 0.01) which was prevented in the AA-FR group (1.44 +/- 0.13 ml, not significant against controls). Arthritis increased serum NO and reduced ALB levels; both changes were significantly restored in the FR-AA group. Food restriction did not alter the activation of GGTP, or the decrease of PRL mRNA observed in the AA group. Serum CORT was elevated in rats with food restriction (15.49 +/- 2.1 vs. 3.7 +/- 0.87 microg/dL) and remained enhanced to the same extent in AA and FR-AA groups. The tailflick latency prolonged in the AA group was reduced by food restriction. CONCLUSION: These results show that 40% food restriction associated with elevated CORT levels mitigated the inflammatory parameters activated during AA.

Animals↗