Biomedical subjects

D J Kraus

Publications and source records attributed to D J Kraus.

5 recordsLinked to original sources

PubMed1999

Abnormal liver metabolism in cancer patients detected by (31)P MR spectroscopy.

There is accumulating evidence indicating that the presence of malignant disease is accompanied by profound changes of liver metabolism in the cancer-bearing host. We previously reported [P. C. Dagnelie, J. D. Bell, -S. C. R. Williams, T. E. Bates, P. D. Abel and C. S. Foster, Br. J. Cancer 67, 1303-1309 (1993)] marked (31)P MRS-detected alterations in phosphorylation status as well as in phospholipid and glucose metabolism in the liver of rats bearing Dunning prostate tumours. The aim of the present study was first to define abnormalities in liver metabolism in patients with a distant malignancy using (31)P MRS, and second to explore the value of including long-TR sequences in clinical (31)P MRS studies of the liver. Liver metabolite levels were expressed relative to total MR-detectable phosphate. In weight-losing (WL, n = 10), but not in weight-stable (WS, n = 13) cancer patients, liver phosphomonoester (PME) levels were significantly elevated, whereas phosphodiester (PDE) levels were reduced when compared with age-matched healthy subjects (n = 12). The TR 20:1 s ratio of PDE was increased in WS and WL cancer patients, suggesting longer T(1). At TR 20 s, but not at TR 1 s, ATP levels were significantly reduced in in WS and WL cancer patients compared with healthy subjects; similarly, P(i) levels were reduced in WL patients at TR 20 and 5s, but not at TR 1 s. ATP:P(i) ratios were unchanged regardless of TR. pH values increased in the order: healthy < cancer-WS < cancer-WL. The PME chemical shift had significantly moved downfield in cancer patients, reflecting increased contributions from glycolytic/gluconeogenic intermediates. The observed changes in PME are consistent with previous reports suggesting increased gluconeogenesis in the liver of patients with a distant malignant tumour. Furthermore, our data support the use of including long-TR sequences in clinical (31)P MRS liver studies.

Adenosine Triphosphate↗

PubMed1996

Management of thyroid ophthalmopathy.

The pathogenesis of thyroid ophthalmopathy and its relation to thyroid gland dysfunction defies elucidation, and thus only palliative therapy exists. If and how antithyroid therapy affects the course of thyroid eye disease remains controversial. Research continues to try to reveal a subset of patients who respond best to corticosteroid or radiation treatment. Innovations in the surgical correction of upper eyelid retraction, orbital decompression technique, and the approach to restrictive myopathy help improve outcome. Preliminary knowledge concerning octreotide suggests that it may play a role in thyroid ophthalmopathy treatment and prevention. Future studies still need to answer basic questions about the treatment of thyroid ophthalmopathy.

Combined Modality Therapy↗

PubMed1993

Treatment of thyroid ocular myopathy with adjustable and nonadjustable suture strabismus surgery.

Our results pooled with those of others demonstrate a statistically significant improvement in outcome when adjustable sutures are implemented in the treatment of thyroid ocular myopathy. To our knowledge, this degree of significance has not been reported previously. We believe the value of adjustable suture strabismus surgery lies mainly in the prevention of large undercorrections and overcorrections. However, one cannot guarantee fusion or long-term alignment stability, especially without prism use. A randomized, prospective, controlled study to compare the nonadjustable and adjustable techniques for the treatment of thyroid ocular myopathy has yet to be performed. The success of any type of strabismus surgery relies on many factors. Future endeavors should implement the quantified adjustable suture technique to better define how preoperative conditions influence the response to strabismus surgery in Graves' patients.

Adult↗

PubMed1984

Effects of luminance and flicker on ocular dominance shift in kitten visual cortex.

We raised monocularly deprived kittens in visual environments with low level illumination that was either steady or flickering. With steady scotopic luminance ocular dominance shifted as it does in normal photopic lighting. In flickering light with an average frequency of 2 Hz there was virtually no ocular dominance shift, while in flickering light averaging 0.1 Hz there was a significant shift. Recordings from the 2 Hz flicker-reared were similar to the dark-reared recordings. The flickering illumination was produced in one case by a high contrast-low brightness TV near the cage, and in another case, by a low voltage incandescent bulb driven by a pseudo-random sequence generator. This circuit delivered either a maximum ON time of 1.7 s or a maximum of 40 s, for the 2 Hz and 0.1 Hz respectively. Both the TV and flickering bulb produced average illumination comparable to the dim (0.01 cd/m2) steady scotopic illumination. We conclude that dim flickering light is not a sufficient stimulus for promoting ocular dominance shift in kittens in the critical period unless the flicker rate approaches 0.1 Hz. Furthermore results from the TV rearing suggest that flicker may be capable of preventing an ocular dominance shift expected from a concurrent steady low light level background.

Animals↗

PubMed1984

A possible indication for red cell lithium determinations: a case report.

The recommended prophylactic lithium levels in the treatment of manic depressive patients differ from study to study. In this paper, we present a patient who was maintained euthymic on lower plasma levels than those recommended. However, we theorize that the reason for this may be due to the fact that she had a high RBC/plasma ratio. We recommend that in those patients whose plasma lithium levels are consistently low, this point should be kept in mind before considering them as noncompliant.

Adult↗