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N P Rowell

Publications and source records attributed to N P Rowell.

24 records · Page 2Linked to original sources
PubMed1990

Quantitative in vivo measurements of tumor perfusion using rubidium-81 and positron emission tomography.

Rubidium-81 (t1/2 = 4.58 hr) was investigated as a tumor perfusion tracer in the VX2 carcinoma implanted into rabbit thigh muscle using a large-area, multiwire proportional chamber positron emission tomography (PET) system. Perfusion was determined using the arterial reference sample method, and the results from PET imaging were compared with postmortem tissue sampling. Absolute quantitation of tumor perfusion was achieved using external probes to estimate local extraction fraction. Redistribution of rubidium-81 (81Rb) was investigated using a dual-tracer technique. Average perfusion was found to be 13.5 and 3.7 ml/min/100 g in tumor and normal muscle, respectively. The extraction fraction as estimated from a two-compartment model ranged from 0.94 to 1.00. No significant redistribution of 81Rb was observed in these tissues. Nine patients with malignancies were studied using 81Rb and PET. Tumor perfusion in four patients with carcinoma of the breast was elevated by a factor of 1.8 (range 1.2-2.3) compared to contralateral normal breast.

Animals↗
PubMed1989

Technetium-99m HMPAO and SPECT in the assessment of blood flow in human lung tumours.

In order to assess the blood flow patterns through human lung tumours, 20 patients received 400-750 MBq 99TcmHMPAO intravenously 10 min before single photon emission computed tomography (SPECT). Ratios of uptake in the whole tumour relative to normal lung ranged from 0.35 to 1.53 (mean 1.01) with eight tumours showing less uptake than normal lung and ten showing greater uptake. In one patient the tumour was not distinguishable from surrounding lung and in another a large pleural effusion prevented evaluation. Tumour: lung ratios for central tumour regions ranged from 0 to 1.83 (mean 0.80) with 13 showing lower uptake than normal lung and five showing greater uptake. Duplicate scans were performed in eight patients demonstrating satisfactory reproducibility. This technique provides a simple and reproducible method for the assessment of tumour blood flow.

Adult↗
PubMed1989

99Tcm-labelled meso-HMPAO and glutathione content of human lung tumours.

Levels of reduced glutathione (GSH) are increased in some types of malignant tumours and are known to influence the response to radio- and chemotherapy. In vitro studies suggest a correlation between cellular GSH concentration and retention of the meso form of hexamethyl propyleneamineoxime (HMPAO). This study investigates the relationship between in vivo tissue retention of 99Tcm-labelled HMPAO and GSH concentration in ten patients referred for thoracotomy for possible lung cancer. Retention of 99Tcm-HMPAO was measured using single photon emission computed tomography (SPECT). The tumour and normal lung concentration of reduced glutathione (GSH) was measured in tissue specimens collected peroperatively. Malignancy was confirmed in eight patients. Of seven patients undergoing curative resection for carcinoma, tumour GSH concentration was higher (mean 2.76 mM) than normal lung (mean 1.04 mM). In one neurofibroma, the GSH concentration was 1.80 mM. No correlation was found between 99Tcm meso-HMPAO retention and either the tumour GSH concentration or the tumour:lung GSH ratio. The results from this small series demonstrate that the intracellular GSH concentration of malignant lung tumours is generally higher than that in normal lung but that meso-HMPAO retention could not be used to predict these levels.

Carcinoma, Non-Small-Cell Lung↗
PubMed1987

Aminoglutethimide as second-line hormonal therapy in advanced breast cancer: response and toxicity.

Seventy-nine postmenopausal patients received aminoglutethimide (AG; 750 mg daily) and hydrocortisone therapy for metastatic or locally recurrent breast cancer following the failure of other hormonal therapy. Fourteen of 64 patients, tolerating the drug and assessable for response, achieved a complete or partial response. Disease stabilisation occurred in a further 2 patients giving a response rate of 25% in these patients. Median duration of response was 10 months. Response rates to AG were not significantly different whether or not there had been a response to previous hormonal therapy but a trend to higher response rates in ER rich tumours was observed. Those with a longer interval from first relapse to the start of AG appeared more likely to respond. Side-effects were noted in 35 patients overall (44%) and in 70% of those over the age of 65 years. Treatment was discontinued because of toxicity in 10 patients and there was one death due to agranulocytosis. AG is active in postmenopausal breast cancer following failure of first-line hormonal therapy, toxicity limiting its use earlier in the disease.

Adult↗
PubMed1984

Myxoedema presenting as epilepsy.

A case of myxoedema presenting as epilepsy is described. In myxoedematous patients without demonstrable cause for their fits, the epilepsy commonly responds to thyroid replacement therapy alone. In this patient, control of hypertension was ineffective in eradicating fits. The association between myxoedema and epilepsy, though previously reported, is surprisingly uncommon and represents a good prognosis within new epileptics.

Aged↗