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Biomedical subjects

J H Todd

Publications and source records attributed to J H Todd.

At least 55 records · Page 3Linked to original sources

Static and dynamic imaging with indium-III labelled Bleomycin in the localization of squamous cell neoplasia.

Fifty two cases of squamous cell carcinoma were studied using indium-111 labelled Bleomycin. The overall accuracy of localization by static imaging alone was 80%. Detection of lung and gynaecological tumours was most consistent, while oesophageal tumours were the most commonly missed. Imaging within a few hours of administration of the radiopharmaceutical was found to be as effective as imaging at the recommended time of at least 24 hours. Inflammatory lesions giving false positive scans could be differentiated from tumour tissue by the technique of dynamic imaging. Maximum activity occurred in tumour tissue on average ten minutes after the peak for normal tissue. This difference was used to improve the detection of known tumours to 90%.

Adult↗

Cerebral blood flow changes in acute experimental haemorrhagic vasospasm.

Subarachnoid haemorrhage was produced in 26 dogs by injecting fresh homogenous blood into the cysterna chiasmatica. Two types of vasospasm were observed, firstly segmental arterial spasm closely related to the bleeding point and secondly generalized arterial vasospasm not directly related to the bleeding point and often occurring some way from the bleeding point. Reduction in CBF occurred in 61% of cases and was always accompanied by radiological vasospasm. However, in about one quarter of the cases with vasospasm there was no alteration in CBF.

Animals↗

Chemical communication in social behavior of a fish, the yellow bullhead (Ictalurus natalis).

Studies of behavior in yellow bullheads showed that they recognized individuals of their own species by means of pheromones. After training by reward and punishment, blinded bullheads were able to discriminate between the odors of two donor fish, but they lost this ability when deprived of their sense of smell. The main source of the intraspecific chemical stimuli involved in recognition is the mucus. A change in status after fighting was chemically communicated to other bullheads.

Animal Communication↗

Orientation by taste in fish of the genus Ictalurus.

Fish of the genus Ictalurus can find distant chemical clues by means of taste alone, and they exhibit true gradient searching in the absence of a current. Neither unilateral nor bilateral deprivation of the sense of smell impaired their searching ability, but unilateral deprivation of taste receptors which are spread over body and barbels of the animals caused pro nounced circling toward the intact side. The relation of swimming paths of the fish to the chemical in the water suggested that comparisons of concentrations were made in time and space.

Animals↗

Comparison of mastectomy with tamoxifen for treating elderly patients with operable breast cancer.

STUDY OBJECTIVE: Comparison of tamoxifen and mastectomy in treatment of breast cancer in elderly patients. DESIGN: Randomised trial of treatment of operable breast cancer by wedge mastectomy or tamoxifen, with median follow up 24 and 25 months respectively (range 1-63). SETTING: University hospital; most patients from primary catchment area. PATIENTS: 135 consecutive patients with breast cancer aged over 70 with operable tumours (less than 5 cm maximum diameter); 68 were allocated to tamoxifen group and 67 to mastectomy group. Histological diagnosis by biopsy. Two incorrect randomisations in each group. Patient characteristics similar in the two groups and all under care of one surgical team. INTERVENTIONS: Mastectomy group received wedge mastectomy plus excision of symptomatic axillary lymph nodes. Tamoxifen group received continuous treatment with tamoxifen 20 mg twice daily. Patients in tamoxifen group received wedge mastectomy if there was sign of local progression. Those in mastectomy group received further excision or radiotherapy for locoregional recurrence and when local treatments had been exhausted or metastatic disease diagnosed they received tamoxifen. END POINT: Treatment efficacy was assessed by local control of disease and by survival. MAIN RESULTS: Mortality from metastatic cancer in tamoxifen group was 7 (10.6%) and in mastectomy group 10 (15.3%) (NS). There was no difference in survival between the two groups. In mastectomy group 70% remained alive and free of local recurrence at 24 months; in tamoxifen group only 47% remained alive and free of local progression. In mastectomy group locoregional recurrence occurred in 16 patients and metastatic disease in 13; in tamoxifen group locoregional progression occurred in 29 patients and metastatic disease in seven. CONCLUSIONS: As a high proportion of patients treated with tamoxifen eventually required surgery treatment of elderly patients with breast cancer should include mastectomy. Optimum treatment may include both mastectomy and tamoxifen.

Aged↗

Tissue culture of human renal epithelial cells using a defined serum-free growth formulation.

BACKGROUND: Development of the culture of renal epithelial cells in a serum-free growth medium was driven by the need to examine the effects of hormones and other effector molecules on differentiated cell function without interference from the complex mixture of substances in serum. The present report details this laboratory's cumulative experience in the use of a defined growth medium for the propagation of epithelial cells from adult, fetal, and malignant human renal tissue. METHODS: Routine cell culture technology was used to determine the capability of a defined growth medium to support the growth of renal epithelial cells isolated by collagenase dissociation of tissue from adult and fetal kidneys, renal cell carcinoma, and Wilms' tumors. RESULTS: The defined growth medium formulation consistently allows the isolation and growth of transporting renal epithelial cells from both normal adult and fetal kidneys. This growth medium only rarely supports the growth of epithelial cells from renal cell carcinomas and Wilms' tumors. CONCLUSIONS: The method developed for the culture of human proximal tubule cells requires minimal cell culture expertise and equipment, and results in the repeatable isolation of transporting epithelial cell cultures that retain features of differentiated proximal tubule cells.

1-Methyl-3-isobutylxanthine↗