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Biomedical subjects

B N Gray

Publications and source records attributed to B N Gray.

At least 55 records · Page 3Linked to original sources
PubMed1987

The profile of breast cancer in Western Australia.

Information concerning all 435 women who presented with primary breast cancer in Western Australia during 1984 was obtained by a review of the WA Cancer Registry, hospital, histopathological laboratory, and medical practitioner records. The age-standardized and cumulative incidence rates were 55.7 per 100,000 women and 6.4%, respectively. The probability that a woman would develop breast cancer during her lifetime (to the age of 74 years) was one in 15.6. There was a significant seasonal variation in the incidence of breast cancer, with a peak in spring (November) and a low in winter (July). The highest incidence rates occurred in women who had never had any children, those of professional status and those who lived in better socioeconomic areas. Stage-I disease accounted for only 22% of all breast cancers. A younger age was associated with a greater proportion of oestrogen-receptor-negative tumours and a longer symptom interval correlated with larger primary tumours. The findings support the concept that the characteristics of Australian women with breast cancer are similar to those that have been described in British and North American women.

Age Factors↗
PubMed1987

Distribution of different sized microspheres in experimental hepatic tumours.

The extent of embolization of different sized radioactive microspheres in experimental tumours and the homogeneity of their distribution in normal liver was examined in 25 rats. The ratio of arterially introduced microspheres lodging in tumour tissue compared to the surrounding normal hepatic parenchyma was measured for 15, 32.5 and 50 microns diameter tracer microspheres. The mean tumour to liver arterial perfusion ratio (T/L) for 15 and 32.5 microns spheres was approximately 3:1 in both cases and there was no significant difference between these values (P greater than 0.05). However, 50 microns microspheres did not preferentially lodge in malignant tissue (mean T/L ratio 1:1). The homogeneity of distribution of microspheres embolizing in the normal liver tissue was assessed for each microsphere size. As microsphere diameter increased from 15 to 50 microns, microspheres lodged more evenly throughout the liver substance. For 15 microns microspheres the coefficient of variation was 55.5% +/- 8.3 and 32.5 microns microspheres distributed with a coefficient of 35% +/- 16.8 while 50 microns spheres distributed most evenly with a coefficient of 19.7% +/- 6.8.

Animals↗
PubMed1987

Redistribution of blood flow in experimental hepatic tumours with noradrenaline and propranolol.

Noradrenaline induced changes in the distribution of blood flow in implanted tumour and normal liver tissue was measured using blood flow tracer microspheres. The ratio of embolised microspheres in tumour compared to normal tissue was determined before and after the intravenous infusion of noradrenaline, propranolol and a combination of the two drugs. The ratio was significantly decreased by noradrenaline alone but significantly increased when propranolol was added to the infusate. Propranolol had no effect on the ratio. The drug combination increased the tumour to normal ratio by approximately 69% and also doubled the proportion of microspheres entering the internal tumour circulation. This represents an enhanced relative blood supply to tumour and would provide a means of preferential carriage of blood borne cytotoxic agents to tumour tissue rather than normal tissue.

Animals↗
PubMed1987

Survey of the management of primary breast cancer in Western Australia.

A postal survey of all general surgeons in Western Australia was undertaken in order to document their current attitudes towards the management of primary breast cancer. The commonest surgical procedure preferred for stages I and II breast cancer was a modified radical mastectomy, although a substantial number (31%) of surgeons favour breast conserving procedures for primary tumours less than 2 cm in size. Few (3%) surgeons still perform a classical radical or extended radical mastectomy. There is a wide diversity of practices regarding pre-operative investigations and postoperative management. Although many surgeons (68%) use aspiration cytology to determine the histologic nature of breast lumps, the majority (62%) do not use mammography to monitor the contralateral breast. After breast conserving surgery, 60% of surgeons would not refer their patients for adjuvant radiotherapy and over 33% would not favour the use of adjuvant systemic therapy for women with stage II breast cancer. It is concluded that the wide diversity in the pattern of management reflects uncertainty regarding the best approach to this disease.

Breast Neoplasms↗
PubMed1986

Controlled clinical trial of ranitidine in bleeding peptic ulcer.

One hundred and two patients were entered into a controlled, randomized clinical trial to assess the value of ranitidine versus placebo, given immediately after entry to hospital to modify the outcome of patients admitted to hospital with acute bleeding from peptic ulceration of the stomach or duodenum. The results indicated that ranitidine could not significantly modify the blood requirements, rebleeding rate or operation rate in this patient population during the initial hospital admission.

Clinical Trials as Topic↗
PubMed1985

Manipulation of experimental rat and rabbit liver tumor blood flow with angiotensin II.

The effects of angiotensin II on the distribution of blood flow to experimental hepatic tumors in ten rats and rabbits were examined using blood flow tracer microspheres. The ratio of arterially introduced microspheres lodging in tumor tissue compared to the surrounding normal hepatic parenchyma was measured before and after i.v. infusion of angiotensin II-inducing incremental systemic responses. A significant elevation (P less than 0.05) in this ratio was described for both rats (3.0-fold) and rabbits (3.2-fold) following the drug infusion. Ratio elevation occurred in 37 of 40 tumors examined despite the lack of a clear dose-response relationship. In addition, angiotensin II was found to significantly (P less than 0.05) increase the number of microspheres gaining arterial access to the central portions of the tumors. In terms of internal radiation therapy, these results would indicate a substantially enhanced radiation dose reaching tumor tissue after angiotensin II infusion, while relatively sparing the surrounding normal tissue.

Angiotensin II↗
PubMed1984

Haematemesis and melaena at St. Vincent's Hospital, Melbourne.

One hundred and fifty-three patients with haematemesis and melaena were studied retrospectively. The majority were managed in general medical units. Fifty-one per cent had a past history of peptic ulcer and/or bleeding, and only 9% had no identifiable predisposing factors. Endoscopy was the major diagnostic tool, with a diagnostic rate of 85%. Nineteen per cent of patients had no diagnostic investigations performed for varied reasons. The operative rate was 15% overall, with an operative mortality of 17%. The presence of other serious disease states concomitant with the haematemesis and melaena, and the presence of oesophageal varices as the aetiology, were both shown to be associated with statistically worse prognoses. Age of greater than 50 years and transfusion of four or more units of blood were also associated with a worse prognosis. Overall mortality was 14%, comparable to or less than that at several institutions, but more than double that of a Haematemesis and Melaena Unit in another Melbourne hospital [Br. Med. J. 1, 1238-40 (1979)] Patient population should be considered closely when comparing mortalities from different series. It is felt that results could be improved using a combined medical and surgical approach, and a set protocol of management, and that such changes should be monitored via a prospective study.

Australia↗
PubMed1984

Value of CEA in breast cancer.

Plasma carcino-embryonic antigen (CEA) is elevated in a small percentage of patients with early breast cancer and in about 60% of patients when the disease is disseminated beyond regional lymph nodes. It is neither sufficiently sensitive or specific a test to be used for mass screening and is of limited use as a diagnostic aid. Monitoring of patients following mastectomy with serial estimations of plasma CEA is of little value in detecting disease recurrence before it becomes clinically apparent. Monitoring of CEA levels may be helpful in objectively assessing response to treatment in patients with disseminated breast cancer.

Breast Neoplasms↗
PubMed1983

Acute-phase reactant proteins and carcinoembryonic antigen in cancer of the colon and rectum.

One hundred and twenty-eight patients bearing primary malignancies of the large bowel were studied to ascertain the value of acute-phase reactant proteins (serum protein hexose, ceruloplasmin, transferrin, alpha-1-antitrypsin, seromucoid and haptoglobin) either alone or in conjunction with carcinoembryonic antigen to accurately reflect the disease status of patients both before and after resection of their large bowel malignancy. The results indicate that acute-phase reactant proteins have a higher diagnostic rate for the presence of malignancy than does CEA. Estimation of the serum protein hexose alone is of greater diagnostic value than a combination of acute-phase reactant proteins. Furthermore, serum protein hexose and CEA are complementary and when combined will reflect the presence of malignancy in a greater number of patients than either one alone. Following resection of primary large bowel cancer, acute-phase reactant proteins are as accurate as CEA in evaluating the disease-free status of patients and furthermore when combined with CEA increased the predictive value for the detection of patients with recurrent disease.

Acute-Phase Proteins↗
PubMed1983

Hepatic metastases--a physiological approach to treatment.

Hepatic metastases derived from primary malignancy of the gastrointestinal tract have a grave prognosis, with median survival rates varying from 3 to 11 months. Surgery for isolated metastases and intrahepatic artery chemotherapy are the most effective treatment options currently available. We have explored the potential use of radioactive microspheres delivered into the liver by the hepatic artery as a form of internally irradiating metastatic liver cancer. Microspheres containing radioactive Yttrium injected into the hepatic artery concentrate in the metastases rather than normal liver parenchyma, due to the fact that the blood supply of metastases is derived preferentially from the hepatic artery. Using a rabbit tumour model, radioactive microspheres delivered into the hepatic artery have been shown to lodge preferentially in tumour tissue. The therapeutic application of this phenomenon is that metastases may receive many times the radiation dose delivered to normal liver parenchyma when radioactive microspheres are delivered into the hepatic artery. This would mean that a mean dose of 30 Gy delivered to normal liver tissue would result in greater than 150 Gy being delivered to tumour tissue. Current results in experiments suggest that this form of treatment may have considerable potential for prolonging survival of patients with hepatic metastases.

Animals↗
PubMed1983

Peripheral blood lymphocyte levels in large-bowel cancer.

The relationship between peripheral blood lymphocyte levels and monitoring and assessment of prognosis of patients with large-bowel cancer has been assessed. There does not appear to be a correlation between the absolute lymphocyte count and the state of disease. Furthermore, the preresection and postresection lymphocyte levels do not accurately predict the likelihood of recurrent cancer subsequently developing, and the serial monitoring of patients with peripheral blood lymphocyte levels adds no important new information to clinical follow-up.

Adenocarcinoma↗
PubMed1983

Internal radiotherapy for hepatic metastases I: The homogeneity of hepatic arterial blood flow.

Internal radiotherapy, in the form of arterially infused yttrium-90-labeled microspheres, theoretically appears encouraging as a method of treatment for hepatic metastases. Previous investigators have assumed a homogeneous distribution of these microspheres and given dosages of isotope based solely on an estimated liver mass. The purpose of this study has been to establish the homogeneity of isotope distribution in liver substance when 15 micrometers microspheres are arterially injected. This has been done in three mammalian species, with the results expressed as a mean percentage coefficient of variation of 28 +/- 5%. Also demonstrated is the fact that 15 micrometers particles, while not penetrating to the venous circulation, achieve a more homogeneous spread throughout the liver than larger particles. It has been demonstrated that to achieve this maximum homogeneity distribution, 4000 beads/g of liver tissue are required. This equates in the therapeutic situation to a maximum activity of 4 Ci/g of infused microspheres. These results are considered significant in that they indicate criteria necessary to achieve the maximum homogeneity of therapeutic agent within liver substance when it is administered by this method, and will allow confidence limits to be attached to direct in vivo measurement of hepatic irradiation.

Animals↗
PubMed1983

Internal radiotherapy for hepatic metastases II: The blood supply to hepatic metastases.

Given that metastatic hepatic malignancy remains as a significant cause of death, with a median survival after diagnosis of only 7 months despite treatment, there exists a need for some effective treatment modality. Internal radiotherapy in the form of yttrium-90 microspheres infused into the hepatic artery appears to be a promising method of therapy. One criterion required for the success of this treatment is that of a differentially greater arterial supply to tumor as opposed to liver tissue. This arterial hypervascularity of tumor has been demonstrated before. However, some conflict has been reported as to the maintenance of this state as tumor size increases. Using 15 micrometers Cobalt-57 microspheres for studying salivary adenocarcinoma implants in DA rat livers, these experiments have demonstrated a constant blood flow in the tumor periphery of 3.9 times that within the normal hepatic parenchyma, regardless of tumor size. Also demonstrated is a progressive decrease in central tumor arterial blood flow after a tumor diameter of 6 mm has been exceeded. Arterial hypervascularity of liver tissue adjacent to the tumor has been demonstrated while an intermediate zone of liver tissue appeared hypovascular, suggesting the presence of shunting. In three humans with metastatic liver disease, hepatic artery infusion of particulate radiotracer has demonstrated the peripheral tumor hypervascularity and relative central tumor hypovascularity with good correlation obtained with the images of the metastases on conventional colloidal hepatic scintigraphy. This method allows assessment of the patient's suitability for internal radiotherapy by enabling assessment of the tumor vascularity and the degree of potentially dangerous extrahepatic irradiation.

Animals↗
PubMed1983

Monitoring of patients with carcinoma of the large intestine by use of acute phase proteins and carcinoembryonic antigen.

Fifty-two patients with resectable carcinoma of the colon and rectum have been monitored by three monthly serial estimations of three APRP (serum protein hexose, transferrin and ceruloplasmin) together with CEA. In 36 patients, subsequent clinical evidence of a recurrence of the disease developed during the study period. Monitoring with APRP can detect a recurrence of the disease at the subclinical stage in the majority of patients and appears to be complimentary to monitoring with CEA. However, due to the low incidence of surgical removal of recurrent carcinoma, this does not give real benefit for patients.

Acute Disease↗
PubMed1982

Use of serum copper/zinc ratio in patients with large bowel cancer.

The serum copper/zinc ratio was measured in 44 patients bearing primary large bowel malignancies. Measurements were repeated following removal of the primary tumour and again at the time of development of clinical evidence of cancer recurrence in order to evaluate the clinical value of the ratio to accurately reflect the presence or absence of malignancy. Estimation of serum copper levels do reflect the presence of malignancy, but the copper/zinc ratio is of no added value. As other acute phase proteins have been shown to be superior to serum copper as markers for monitoring of cancer patients, it is concluded that in patients with large bowel cancer, monitoring with serum copper/zinc is of no clinical value.

Ceruloplasmin↗
PubMed1982

Tennessee antigen: the predictive value of preoperative and postoperative assays in large-bowel cancer.

Twenty-nine of 31 patients bearing resectable colorectal cancers had elevated levels of serum Tennessee antigen in comparison with only eight of 31 patients for carcinoembryonic antigen. This high detection rate is, however, of limited value since the level of serum Tennessee antigen is not specific for the presence of malignancy. There appeared to be no relationship between the level of preoperative serum Tennessee antigen and subsequent prognosis. Furthermore, in only nine of 31 patients did the serum Tennessee antigen level fall after removal of all macroscopic cancer. There also appeared to be no relationship between the level of serum TennaGen at three months after resection and subsequent prognosis. These findings are in contrast to estimations of serum carcinoembryonic antigen.

Antigens, Neoplasm↗
PubMed1982

Tennessee antigen: its value in the monitoring of patients with colorectal cancer.

Serial estimations of serum Tennessee antigen have been performed at regular three-month intervals on 35 patients with colorectal cancer who had undergone resection of all macroscopically obvious tumor but who were considered to be at high risk of developing subsequent metastases. The results were interpreted by a panel of surgeons in order to assess the clinical relevance of using serum Tennessee antigen for monitoring of patients. The serial estimation of serum Tennessee antigen was found to be very variable, difficult to interpret, and clinically unreliable as an accurate marker for the development of recurrent cancer in this group of patients. There are unacceptably high false-positive and false-negative diagnostic rates for serum Tennessee antigen estimations in comparison with serial estimations of carcinoembryonic antigen.

Antigens, Neoplasm↗