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Biomedical subjects

J M Gee

Publications and source records attributed to J M Gee.

At least 73 records · Page 4Linked to original sources
PubMed1994

Immunocytochemical localization of BCL-2 protein in human breast cancers and its relationship to a series of prognostic markers and response to endocrine therapy.

The protein product of the bcl-2 gene is though to be involved in inhibition of apoptosis; it may therefore be important in the modulation of hormonal/anti-hormonal responsiveness exhibited by tumours. This study immunocytochemically investigates (i) relationships between bcl-2 protein expression in primary breast cancers and other markers of prognostic and therapeutic value and (ii) associations of the bcl-2 protein with breast cancer responsiveness to endocrine therapy. The bcl-2 protein was found within the tumour epithelial cell cytoplasm of 32/46 breast cancer specimens; inter-patient staining was heterogeneous. Immunostaining for steroid hormone receptors was strongly associated with that for the bcl-2 protein, and it is thus possible that this protein, like progesterone receptor, is under oestrogen regulation via oestrogen receptor. The protein was inversely related to 2 markers of endocrine insensitivity, epidermal growth factor receptor (EGFR) and c-erbB-2 oncoprotein, while no associations were observed with either transforming growth factor (TGF)-alpha or Ki-67 proliferative status. A highly significant relationship was observed between response to endocrine therapy and the presence of bcl-2 protein. Indeed, bcl-2 immunostaining proved to be a more accurate predictor of response than oestrogen receptor status. Patients with elevated bcl-2 immunostaining (particularly those who coexpressed high oestrogen receptor levels) appeared to derive the greatest benefit from endocrine therapy. Our results are paradoxical since it was expected that the bcl-2 protein would counteract the tumour inhibitory effects of endocrine therapies as it is thought to prevent programmed cell death.

Apoptosis↗
PubMed1994

Transforming growth factor-alpha and endocrine sensitivity in breast cancer.

The expression of transforming growth factor-alpha (TGF-alpha) has been evaluated in 51 breast cancers of known responsiveness to endocrine therapy using immunohistochemistry. High levels of TGF-alpha were observed in 65% of tumors and showed no relationship with tumor estrogen receptor or epidermal growth factor receptor status or Ki67 immunostaining. TGF-alpha levels did, however, relate to the endocrine sensitivity of the disease, with unresponsive tumors frequently showing high levels of TGF-alpha immunoreactivity. This relationship was observed in estrogen receptor-positive disease and was independent of the epidermal growth factor receptor status of the tumor. No quantitative association between TGF-alpha and Ki67 immunostaining was observed in any of the subcategories of tumors. These data infer a role for TGF-alpha in the development of endocrine insensitivity in estrogen receptor-positive breast cancer by mechanisms which appear independent of tumor growth fraction, as determined by Ki67 immunostaining.

Biomarkers, Tumor↗
PubMed1994

Epidermal growth factor receptor expression in breast cancer: association with response to endocrine therapy.

106 previously untreated breast cancer patients have been immunohistochemically analysed for EGF-R, ER, Ki67, and c-erbB-2 product. All patients received assessable endocrine therapy following disease progression. Significant associations were observed between EGF-R and ER (inverse) and Ki67 (direct). No association was observed between EGF-R and the c-erbB-2 product. EGF-R expression was significantly associated with the loss of endocrine sensitivity in breast cancer. This was observed in both ER positive and negative disease. In ER positive breast cancers, EGF-R expression had no significant influence on the quality of tumour remissions. Further sub-classification of the ER/EGF-R data by Ki67 immunostaining showed that in ER+/EGF-R-disease, increasing proportions of Ki67 positive cells were associated with a decline in the numbers of women experiencing good quality tumour remissions. A similar trend was also observed in ER+/EGF-R+ tumours. The presence of c-erbB-2 protein product did not influence endocrine sensitivity in any of the ER/EGF-R sub-groups.

Biomarkers, Tumor↗
PubMed1994

Oestrogen-regulated genes in breast cancer: association of pLIV1 with lymph node involvement.

In order to isolate markers of oestrogen responsiveness in breast cancer, we have cloned a number of oestrogen-regulated genes. Two of these, pLIV1 and pLIV2 (pS2), have been shown to be predominantly expressed in oestrogen receptor (ER)+ tumours. In this study, we examined their expression in relation to various clinical and histopathological features of breast cancer, and showed that pLIV1, but not pS2, is significantly associated with lymph node involvement (P < 0.01), while pS2 is more frequently observed in premenopausal patients (P < 0.05). Subdivision of the pLIV1 data by ER and nodal status of the tumour identified a highly significant association between pLIV1 expression and lymph node involvement in ER-positive disease, with 15/24 (63%) ER+ pLIV1+ tumours showing nodal involvement. Conversely, 20/23 (87%) ER+ pLIV1- patients were lymph node-negative (P < 0.001). Subdivision of the pS2 data by ER status did not reach significance. The application of pLIV1 as a marker of lymph node involvement was further exemplified in small tumours (< < 2 cm), where 11/12 (92%) lymph node-positive patients expressed pLIV1, while 17/22 (77%) node-negative patients were pLIV1 negative (P < 0.001). Similarly, pLIV1 expression identified lymph node involvement in moderately differentiated tumours (P < 0.01), but was independent of vascular invasion. pLIV1 may, therefore, represent a candidate gene for metastatic spread in ER+ breast cancer.

Breast Neoplasms↗
PubMed1994

Validation of a simple technique for the detection of abnormal mucosal cell replication in humans.

Abnormal intestinal crypt cell proliferation is considered to be an important early risk marker for colorectal cancer but measurement of the rate and spatial distribution of cell division by histochemical localization of DNA synthesis is labour-intensive and expensive. We developed and evaluated a simpler technique for measurement of these parameters using direct visual analysis of mitotic figures in microdissected crypts. The direct crypt analysis technique was applied to colorectal biopsies from patients with ulcerative colitis or no mucosal abnormality. A characteristic shift of cell division toward the intestinal lumen was detected in patients with ulcerative colitis. The direct method was validated using rats fed diets containing cellulose, or guar gum to stimulate mucosal cell proliferation. The crypt cell proliferation rate (CCPR) was measured by the metaphase-arrest technique and the results were compared with direct crypt analysis. There was a fivefold range of CCPR values at three sampling sites across the dietary groups. An excellent linear correlation between the results by the two techniques was obtained (r = 0.98; P < 0.001). In a second experiment the spatial distribution of dividing cells between five zones in colonic crypts, determined by the new method or by staining with BrdU, was compared. Good agreement was again achieved. Visual analysis of intact crypts is a valid technique for the measurement of crypt cell cytokinetics and it is particularly suited for use in a clinical environment.

Animals↗
PubMed1993

Presence and possible significance of immunocytochemically demonstrable metallothionein over-expression in primary invasive ductal carcinoma of the breast.

Metallothioneins (MTs) are ubiquitous low-molecular-weight proteins with a high affinity for heavy metal ions such as zinc, copper and cadmium. MT over-expression has been associated with resistance against anticancer drugs. In the present study we investigated 86 cases (45 cases of tumour category pT1 and 41 of category pT2) of routinely fixed and paraffin-embedded primary breast carcinomas immunohistochemically with a monoclonal antibody to an epitope of MT shared by its I and II isoforms. Immunohistochemically demonstrated MT over-expression was found in the invasive components of 7 of 32 pT1 and 17 of 28 pT2 invasive ductal carcinomas, whereas all 26 invasive lobular carcinomas gave weak or negative results. Fourteen of 17 pT2 and 2 of 7 pT1 invasive ductal carcinomas with MT over-expression developed metastases during follow-up with poor prognostic outcome. In contrast only 3 of 11 pT2 and none of the 25 pT1 cases without MT over-expression had a poor clinical course (P < 0.001). It is concluded that MT over-expression is associated with significantly poor prognosis particularly in pT2 invasive ductal breast carcinomas.

Adult↗
PubMed1993

The role of four oestrogen-responsive genes, pLIV1, pS2, pSYD3 and pSYD8, in predicting responsiveness to endocrine therapy in primary breast cancer.

The expression of four oestrogen-responsive genes in 118 immunohistochemically defined primary breast tumours has been determined by northern analysis. While all the genes are induced by oestrogen in oestrogen receptor (ER)-positive cell lines, their behaviour is different in breast tumour biopsies. This behaviour can be divided into two groups; the first containing the genes, pLIV1 and pLIV2 (pS2), which both show a significant association with ER status (P = 0.001) and a corresponding inverse relationship with epidermal growth factor receptors (EGFR) (P = 0.01 and P = 0.08, respectively). In addition, the mRNA levels of both pLIV1 and pS2 are greater in ER-positive compared to ER-negative disease (P = 0.001). While a small number of ER-negative tumours were positive for either pLIV1 (12%) or pS2 (9%), we failed to observe co-expression of pLIV1 and pS2 in ER-negative disease. In ER-positive disease, four tumour populations were identified; ER+pLIV1-pS2-, ER+pLIV1-pS2+, ER+pLIV1+pS2- and ER+pLIV1+pS2+. Interestingly, the levels of pLIV1 and pS2 when co-expressed were significantly greater in ER+pLIV1+pS2+ tumours compared to either of the ER+pLIV1+pS2- (P = 0.03) or ER+pLIV1-pS2+ (P = 0.01) mixed phenotypes. Unlike pLIV1 and pS2, pSYD3 and pSYD8 belong to a group of genes which are expressed in the majority of tumours regardless of ER and EGFR status. However, lower pSYD8 mRNA levels were detected in moderately EGFR-positive disease (P = 0.06) while both pSYD3 positivity (P = 0.01) and mRNA levels (P = 0.001) were increased in highly proliferating tumours as shown by Ki67 immunostaining. These genes provide additional markers which, in conjunction with other parameters, may help to determine the likelihood of a given tumour to respond to endocrine therapy.

Biomarkers, Tumor↗
PubMed1993

'Determination' of sugar alcohol and Polydextrose absorption in humans by the breath hydrogen (H2) technique: the stoichiometry of hydrogen production and the interaction between carbohydrates assessed in vivo and in vitro.

The production of hydrogen from substrates and substrate mixture of sugar alcohols and Polydextrose was determined, both in vivo using the breath hydrogen test, and in vitro, using human faecal microorganisms in anaerobic culture. One objective was to test a previous assumption that the stoichiometry of hydrogen production from different alternative carbohydrates is similar. Another objective was to discover whether hydrogen responses from mixtures of substrates were simply additive, or whether interactions occurred. The breath tests were performed in a 10 subject x 10 substrate factorial design with substrates and substrate mixtures (5-11 g) administered in 42 g chocolate confectionery. Incorporation of the alternative carbohydrates lactitol (L), Isomalt (I) and Polydextrose (P) into otherwise conventional confectionery increased breath hydrogen production by approximately 112, 73 and 11%/g respectively. There was no interaction between L and I or between P and I, but a combination of L and P approximately doubled the breath hydrogen anticipated from their individual contributions (P < 0.05). Anaerobic cultures showed a sixfold range in the efficiency of converting individual substrates and mixtures to hydrogen gas (0.003-0.018 kJ H2 per kJ carbohydrate). The positive interaction between L and P, and the lack of interaction between L and I, and between P and I, found in vivo were reproduced in vitro. The work showed that interpretation of the hydrogen breath test is confounded by differing stoichiometries for hydrogen production, by interaction between substrates and by an uncertain extent to which small intestinal hydrolysis yielding species with a fermentation stoichiometry that differs from the parent substrate.

Absorption↗
PubMed1992

Dietary corn oil and guar gum stimulate intestinal crypt cell proliferation in rats by independent but potentially synergistic mechanisms.

The effects of corn oil, guar gum and cellulose on mucosal proliferation were investigated in rats. Animals were allocated to three groups and fed a fiber-free diet or diets containing 100 g/kg of cellulose or guar gum. Each group was subdivided to receive corn oil at 40 or 80 g/kg. The crypt cell production rate (CCPR) was determined after 28 d. Consumption of guar gum or corn oil led to greater CCPR in the ileum and cecum. In a second experiment, animals were allocated to two groups and fed diets containing either cellulose or guar gum (100 g/kg). Each group was again subdivided to receive either corn oil (80 g/kg) or minimal lipid (linolenic acid, 10 g/kg). The trophic effect of guar gum occurred even in the low lipid-fed group, indicating that guar gum exerts a positive effect on cell turnover independently of any interaction with luminal lipid. However, the highest CCPR occurred in animals fed guar gum and corn oil. Postprandial enteroglucagon and gastrin concentrations were highest in animals fed both guar gum and corn oil. Thus, corn oil and guar gum exert independent trophic effects on the intestinal mucosa. The combination of effects led to a three- to four-fold increase in colon mucosal CCPR.

Animals↗
PubMed1992

The effect of ranitidine on urine mucus concentration in patients with enterocystoplasty.

We describe the effect of ranitidine in reducing mucus in urine in 8 patients with enterocystoplasty and present a simple technique for measuring the concentration of mucus in urine. After a 10-day course of ranitidine (300 mg daily in divided doses) the concentration of mucus had fallen significantly from an initial level of 1.38 +/- 0.18 to 0.39 +/- 0.04 mg/ml.

Female↗
PubMed1992

Dietary fat intake and plasma lipid levels in adolescents.

The relationship between dietary fat intake and fasting plasma lipid levels was assessed in 35 female and 19 male adolescents recruited from two local education authority schools in Norwich, UK. Dietary intakes were assessed using a 7-day weighed dietary record method, coupled with the collection of duplicate diets. Fat and energy intakes calculated using food composition tables were compared with values obtained by direct analysis of duplicate diets. Fasting plasma lipid levels (total, HDL and LDL cholesterol and triglycerides) were measured and compared with total dietary lipids and fatty acid intakes. The average proportion of energy consumed as fat was higher than is currently considered desirable but lower than previous studies have reported for adults. Mean serum total cholesterol values were 4.2 (SEM 0.1) mmol for females and 4.5 (SEM 0.2) mmol for males; this difference was not statistically significant. In male subjects the dietary fatty acid profiles were significantly correlated with several parameters of plasma lipid status which are thought to be risk factors for coronary heart disease, and in particular with the ratio of total:HDL cholesterol.

Adolescent↗
PubMed1991

Physiological effects of retrograded, alpha-amylase-resistant cornstarch in rats.

Retrograded amylose was prepared by gelatinization of high amylose cornstarch, followed by storage at 1 degrees C for 48 h. The insoluble residue, which resisted hydrolysis with porcine amylase, was dried and fed to male Wistar rats for 14 d in powdered semisynthetic diet. Control rats received a similar diet containing sucrose in place of resistant starch. Fecal collections were performed throughout the feeding period. After 14 d the animals were killed. The small intestine and cecum were removed for morphological examination, measurement of small intestinal crypt cell production rate (CCPR) and analysis of luminal carbohydrate content. Blood samples were collected for analysis of cholesterol, glucagon, and enteroglucagon. In the starch-fed rats, fecal bulk and excretion of starch were higher than in the controls, but they declined markedly over the feeding period. Cecal size and contents were also greater in the starch-fed rats, and cecal pH was significantly lower. The CCPR was 66% higher in the ileum of the starch-fed rats (P less than 0.001), but there was no difference in the jejunum. There were no differences in serum cholesterol or enteroglucagon levels. We conclude that retrograded amylose is partially degraded in the alimentary tract of rats, but it contributes significantly to fecal bulk.

Amylose↗
PubMed1991

Use of the dinitrophenyl hapten sandwich staining procedure (DHSS) to localize estrogen receptors in paraffin-embedded tissues.

To date, reliable and sensitive methods to localize the estrogen receptor (ER) in rat tissues and human breast cancers have required the use of frozen sections. This not only incurs poor tissue structure but also precludes the study of small breast lesions that are usually paraffin embedded for histological evaluation. We have developed and optimized a dinitrophenyl hapten sandwich staining (DHSS) immunocytochemical procedure to demonstrate ER in paraffin-embedded, hormone-sensitive tissues of the rat and in human breast cancers. The method was applicable to formalin- and Bouins-fixed material, with trypsinization of sections being essential. The immunocytochemical system utilized a dinitrophenyl (DNP) hapten-labeled monoclonal antibody to the receptor. Mouse IgM anti-DNP was used secondarily, followed by a DNP/peroxidase complex, diaminobenzidine/hydrogen peroxide chromogen, and silver intensification. This highly sensitive method localized the ER within paraffin-embedded rat uterus, fallopian tube, vagina, and normal and cancerous mammary gland. Furthermore, excellent staining was generated in human breast cancers in accordance with their ER-ICA status. Control sections involving simultaneous incubation with DNP-labeled and unlabeled H222 were background free, while uteri from castrated rats demonstrated reduced receptor immunostaining. Staining was also absent in ER-negative human breast tumors.

Animals↗
PubMed1991

Effects of conventional sucrose-based, fructose-based and isomalt-based chocolates on postprandial metabolism in non-insulin-dependent diabetics.

Milk chocolate is rich in both sucrose and fat, and is therefore considered unsuitable for diabetics. Nevertheless there is little information on the metabolic effects of conventional chocolate or specialized formulations with reduced sucrose content. In the present study six male non-insulin-dependent diabetes mellitus patients (age range 35-60 years; body-mass index less than 28) consumed test meals of chocolate (75 g) on three separate occasions. The control chocolate contained sucrose (45.5% w/w); the test chocolates contained either fructose (45.5% w/w) or isomalt (45.1% w/w). The latter is a sweet disaccharide alcohol which has no glycaemic effect when consumed as a pure compound. Venous blood samples were obtained at 30 min intervals for 5 h, and analysed for glucose, insulin, lactate and triglycerides. All three chocolates provoked a sustained rise in blood glucose, which reached a maximum at 90 min after ingestion and returned to baseline values by 5 h. The highest blood glucose levels occurred after conventional chocolate, and differences were statistically significant at 60 and 90 min (P less than 0.05). The area under the glycaemic curve for isomalt chocolate was 36% smaller than that for conventional chocolate (P less than 0.05), and there were differences in insulin and lactate levels, consistent with the lower glycaemic effect. The glycaemic response to the fructose-based chocolate was also lower than that to control chocolate but the difference was not significant. All three chocolates led to a similar sustained rise in serum triglyceride levels. Isomalt appears to be a palatable alternative sweetener capable of reducing the glycaemic effect of diabetic confectionary.

Adult↗
PubMed1990

The biological effects and digestible energy value of a sugar-beet fibre preparation in the rat.

A sugar-beet fibre preparation (SBF) was incorporated into a semi-synthetic rat diet at a level of 100 g/kg. The material caused no feed aversion, and gain of live weight was unimpaired. SBF appeared to be slightly more fermentable than wheat bran and only marginally less effective as a faecal bulking agent when compared with equalized intakes of non-starch polysaccharide. SBF did not stimulate mucosal cell turnover in the small intestine. Some enlargement of the caecum was observed in animals given SBF, but it was no greater than that of animals given wheat bran. Animals given SBF had a lower serum cholesterol concentration than both the fibre-free controls and those given wheat bran. This hypocholesterolaemic effect was less than that of guar gum however. The partial digestibility of energy for SBF was 0.64, and its partial digestible energy value was 11.3 kJ (2.7 kcal)/g. The partial digestibility of energy for non-starch polysaccharide in SBF was estimated to be 0.53 and its partial digestible energy value was 9.1 kJ (2.2 kcal)/g. This value was not significantly different from that expected for unavailable carbohydrate in mixed human diets.

Animals↗
PubMed1990

Estrogen deprivation in breast cancer. Clinical, experimental, and biological aspects.

The endocrinological and clinical effects of an LH-RH agonist, Zoladex, and an antiestrogen, Nolvadex, in patients with advanced breast cancer are outlined and their potential in the therapy of nonmalignant diseases of the breast and high-risk states is briefly discussed. Additional data are presented to indicate that new antiestrogens are now available for experimental studies that, unlike tamoxifen, do not possess partial estrogen-like activity and that show favorable antitumor properties against DMBA-induced mammary tumors and MCF-7 human breast cancer cells in culture. The lack of agonistic effects of this new class of pharmacological agents now allows a state of total estrogen deprivation to be approached, a previously unobtainable clinical goal.

Breast Neoplasms↗