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Biomedical subjects

G J Duffy

Publications and source records attributed to G J Duffy.

At least 19 recordsLinked to original sources
PubMed2006

(18)FDG uptake during induction chemoradiation for oesophageal cancer fails to predict histomorphological tumour response.

To determine whether [(18)F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) could predict the pathological response in oesophageal cancer after only the first week of neoadjuvant chemoradiation. Thirty-two patients with localised oesophageal cancer had a pretreatment PET scan and a repeat after the first week of chemoradiation. The change in mean maximum standardised uptake value (SUV) and volume of metabolically active tissue (MTV) was compared with the tumour regression grade (TRG) in the final histology. Those who achieved a TRG of 1 and 2 were deemed responders and 3-5 nonresponders. In the responders (28%), the SUV fell from 12.6 (+/-6.3) to 8.1 (+/-2.9) after 1 week of chemoradiation (P=0.070). In nonresponders (72%), the results were 9.7 (+/-5.4) and 7.1 (+/-3.8), respectively (P=0.003). The MTV in responders fell from 36.6 (+/-22.7) to 22.3 (+/-10.4) cm(3) (P=0.180), while in nonresponders, this fell from 35.9 (+/-36.7) to 31.9 (+/-52.7) cm(3) (P=0.405). There were no significant differences between responders and nonresponders. The hypothesis that early repeat FDG-PET scanning may predict histomorphologic response was not proven. This may reflect an inflammatory effect of radiation that obscures tumour-specific metabolic changes at this time. This assessment may have limited application in predicting response to multimodal regimens for oesophageal cancer.

Adult↗
PubMed2004

Experimental investigation of early-time diffusion in the quantum kicked rotor using a Bose-Einstein condensate.

We report measurements of the early-time momentum diffusion for the atom-optical delta-kicked rotor. In this experiment a Bose-Einstein condensate provides a source of ultracold atoms with an ultranarrow initial momentum distribution, which is then subjected to periodic pulses (or "kicks") using an intense far-detuned optical standing wave. We characterize the effect of varying the effective Planck's constant for the system, while keeping all other parameters fixed. The observed behavior includes both quantum resonances (ballistic energy growth) and antiresonances (re-establishment of the initial state). Our experimental results are compared with theoretical predictions.

Journal Article↗
PubMed1991

Localization of recurrent medullary thyroid carcinoma with technetium-99m-methoxyisobutylnitrile scintigraphy: a case report.

This case report demonstrates the successful localization of metastatic medullary thyroid carcinoma with 99mTc-labeled methoxyisobutylnitrile (MIBI). Disease recurrence was initially localized using 201Tl and by immunoscintigraphy with 111In-labeled anti-carcinoembryonic antigen (anti-CEA) antibody fragments. Scintigraphy with 99mTc-MIBI yielded higher target-to-background ratios than 201Tl or 111In-anti-CEA. Technetium-99m-MIBI may be a useful agent in the localization of recurrent medullary thyroid carcinoma.

Carcinoma↗
PubMed1986

Semi-quantitative gallium-67 lung scanning as a measure of the intensity of alveolitis in pulmonary sarcoidosis.

Gallium-67 (67Ga) lung scanning has been applied for some years in pulmonary sarcoidosis to assess the activity of the alveolitis. Interpreting the scans, however, is difficult due to the low uptake of 67Ga in the disease process relative to background activity. In this study we have measured the mean parenchymal lung activity of 67Ga and have compared the lung activity to that at three remote sites, the liver, the abdomen and the thigh. The results obtained were compared with the percentage of lymphocytes in broncho-alveolar lavage fluid. There was a very good correlation with the lung-to-thigh uptake measurements and a much poorer correlation with the lung-to-liver and the lung-to-abdomen measurements. It was observed that steroid therapy reduced dramatically the correlation between the broncho-alveolar lavage findings and the 67Ga scan measurements. The results suggest that in patients not on steroid therapy, the 67Ga lung-to-thigh measurements may be used, similarly to the broncho-alveolar lavage lymphocyte counts, to identify those with high-intensity alveolitis from those with low-intensity alveolitis.

Adult↗
PubMed1983

Thyroid function in goitrous subjects with thyroxine binding globulin deficiency.

The co-existence of thyroxine binding globulin (TBG) deficiency and euthyroid goitre in the same family raised the possibility that the disorders might be related. However, although both disorders co-existed in some members of the family, other members had either but not both conditions. These observations exclude the possibility that goitre development was solely due to alterations in thyroid activity brought about by TBG deficiency. It is possible, however, that the defect in protein binding might have enhanced goitre development in predisposed individuals as the two largest goitres occurred in TBG deficient subjects. Of the conventional parameters used to assess thyroid hormone levels in TBG deficient subjects, only the free triiodothyronine index consistently reflected the euthyroid status of these patients as established by clinical examination and TSH levels.

Antibodies↗
PubMed1978

Multiple steroid receptors in male breast carcinomas.

Specific cytosol receptors for estradiol, progesterone and dihydrotestosterone were detected in human male breast carcinomas. Competition studies with excess unlabelled steroids showed that the receptors were distinct binding proteins. The properties and binding specificity of the estradiol receptor in a male breast carcinoma were very similar to those found in female breast tumors. The possible clinical significance of the presence of steroid receptors in male breast tumors is discussed.

Binding, Competitive↗
PubMed1977

Measurement of estradiol receptors in human breast tumors by polyacrylamide gel electrophoresis.

1. Specific estradiol receptors in cytosols from human breast tumors were measured by discontinuous polyacrylamide gel electrophoresis. 2. Binding of estradiol to contaminating sex hormone binding globulin was clearly separated from that due to the specific receptor. 3. The amount of estradiol bound by the receptor was linear with respect to the amount of protein added to gel. 4. The estradiol receptor peak of radioactivity showed saturability and specificity characteristic of an intracellular receptor. 5. The results show that polyacrylamide gel electrophoresis can be used to quantitate specific estradiol receptors in the presence of other high affinity binding components.

Breast Neoplasms↗
PubMed1977

Estradiol receptors and glucose-6-phosphate dehydrogenase activity in human breast tumors.

Estradiol receptors and glucose-6-phosphate dehydrogenase, an enzyme induced by estrogens, were measured in both benign and malignant human breast tumors. The mean glucose-6-phosphate dehydrogenase activity was higher in the malignant tumors than in the benign tumors. Tumors containing estradiol receptors contained higher activities of glucose-6-phosphate dehydrogenase than tumors without receptors. In breast carcinomas with and without estradiol receptors glucose-6-phosphate dehydrogenase gave 3 isoenzymes with very similar electrophoretic pattern after polyacrylamide gel electrophoresis. The results showed that although glucose-6-phosphate dehydrogenase was higher in estradiol receptor positive than in estradiol receptor negative tumors there was no significant correlation between the estradiol receptor concentration and glucose-6-phosphate dehydrogenase activity in human breast tumors.

Breast Neoplasms↗