Positive two-stage carcinogenesis in female sprague-dawley rats using 7,12-dimethylbenz(a)anthracene (DMBA) as initiator and 12-o-tetradecanoylphorbol-13-acetate (TPA) as promotor

Summary In contrast to a previous report by Shubik, the validity of the 2-stage skin carcinogenesis experiment was demonstrated in the rat. The modified experiment was carried out in female Sprague-Dawley rats using intragastrically administered DMBA as a carcinogen and the topically applied phorbol ester TPA as a promoter.Seven groups of animals were used. Two groups were treated with TPA only, two groups were initiated only with DMBA, two further groups were both initiated and promoted, and one group served as a control. Each of the initiated/promoted groups or only initiated or promoted groups contained one sub-group in which the animals had been bilaterally ovarectomized prior to the experiment.Hyperplasia of the dorsal epidermis occurred only in the promoted and in the initiated/promoted groups. Tumors of the back skin were observed exclusively after initiation/promotion. Ovarectomy — leading to a prolonged survival time of the animals — seems to be crucial for the manifestation of malignant skin tumors. Initiation/promotion also gives rise to tumors of the forestomach, the small intestine, the liver and the colon. Tumors in other organs (especially in the mammary gland and the Zymbal gland) were also be observed after initiation alone.Dedicated to Professor Wilhelm Doerr on the occasion of his 65th anniversary     

Anti-arthritic effect of GN1, a novel synthetic analog of glucosamine,in the collagen-induced arthritis model in rats

Objective  

Glucosamine is a naturally occurring amino monosaccharide that maintains the elasticity and strength of the cartilage tissues. It has been used to treat osteoarthritis in humans; however, in severe conditions of inflammation and pain, glucosamine alone is not enough, and it is important to improve its biological activity. Our research group has recently taken an interest in the synthetic manipulation of amino sugars to develop some efficient pharmacophores, e.g., β-d-glucosamine, to combat rheumatoid arthritis, and tested its anti-arthritic effects in the collagen-induced arthritis (CIA) model in rats.     

Immunohistochemical and ultrastructural studies of 2,6-dimethylaniline-induced nasal proliferative lesions in a rat two-stage nasal carcinogenesis model initiated with N-bis(2-hydroxypropyl)nitrosamine.

Proliferative lesions induced by 2,6-dimethylaniline (DMA) in a two-stage rat nasal carcinogenesis model were immunohistochemically and ultrastructurally investigated. Male F344 rats received diet containing 3,000 ppm DMA for 52 weeks after initiation with a single subcutaneous injection of 2400 mg/kg of N-bis(2-hydroxypropyl)nitrosamine (DHPN). Histopathologically, proliferation of Bowman's glands, glandular hyperplasias, dysplastic foci, adenomas, and carcinomas were observed in treated rats. These nasal lesions mostly arose in the olfactory mucosa of the nasal cavity. Immunohistochemically, they were positive for cytokeratin and/or collagen type IV antibodies. Ultrastructurally, intracytoplasmic dense secretory granules (200-850 nm in diameter), identical to those in normal Bowman's glands, were observed in all the lesions, providing further support from an origin from these glands. Based on their cellular characterization, growth pattern and/or proliferative activity, two morphological continua were evident, one from dysplastic foci to carcinomas and the other from proliferation of Bowman's glands to glandular hyperplasias and adenomas. These results suggest that dysplastic foci arise from Bowman's glands and progress to carcinomas, while proliferation of Bowman's glands result in glandular hyperplasias and adenomas.     

Antidiabetic and antiacetylcholinesterase effects of ethyl acetate fraction of Chaenomeles sinensis (Thouin) Koehne fruits in streptozotocin-induced diabetic rats

The present study was intended to examine the effects of the supplementation of active α-glucosidase, α-amylase and lipase inhibitory ethyl acetate (CSE) fraction from the fruits of Chaenomeles sinensis (Thouin) Koehne on blood glucose (BG), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), alanine aminotransferase (ALT), aspartate aminotransaminase (AST), acetylcholinesterase (AChE) and antioxidant levels. The diabetic rats were treated orally with CSE at the doses of 50 and 100 mg/kg bw for 14 days. BG, TC, TG, HDL-C, ALT, AST and AChE levels were significantly reduced; on the other hand antioxidant levels were significantly increased in the treated groups. These observations suggest protective effects of CSE against STZ-induced diabetic dementia model.     

Increased Levels of Soluble Tumour Necrosis Factor Receptor-I (P55) and Decreased IgG1 Reactivities in HIV-1 Patients with Cytomegalovirus Disease

The purpose of the study was to investigate potential associations between tumour necrosis factor (TNF), soluble TNF receptors (sTNF-Rs), immunoglobulin (Ig)G subclasses and development of cytomegalovirus (CMV) disease amongst human immunodeficiency virus (HIV)-1 patients. We enrolled HIV-1 patients with CD4 counts less than 100/μl in a prospective study and followed them over 1 year for development of CMV disease. Concentrations of TNF, sTNF-RI, sTNF-RII and IgG subclass reactivities were measured by ELISA; levels of CMV pp65 antigenaemia were determined as numbers of pp65 expressing cells/100 000 cells and were measured by staining of leucocytes; and HIV-1 RNA loads were measured by polymerase chain reaction (PCR). Eighteen patients studied with CMV disease had higher levels of sTNF-RI than 18 similar patients without CMV disease. Concentrations of sTNF-RI correlated with levels of CMV antigenaemia in blood samples collected before the development of CMV disease. Patients with CMV disease had lower levels of IgG₁ reactivities to CMV than patients without CMV disease. We conclude that increased levels of sTNF-RI and decreased IgG₁ reactivities are associated with an increased risk of development of CMV disease among HIV-1 patients.     

Restorative effect of Dendrophthoe falcata (L.f.) Ettingsh on lipids,lipoproteins, and lipid-metabolizing enzymes in DMBA-induced mammary gland carcinogenesis in Wistar female rats

Lipid, lipoproteins, and lipid-metabolizing enzymes are associated with breast cancer risk. In this study, the potential of hydroalcoholic extract (HEDF) of Dendrophthoe falcata (L.f) Ettingsh (Loranthaceae) for the management of lipid metabolism on 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma was investigated in Wistar female rats. Thirty female rats (55 days of age) were divided into five groups: control, DMBA (25 mg in 0.5 ml of olive oil by air pouch technique), DMBA?+?HEDF (250, 475, and 950 mg/kg). After 90 days of induction, HEDF was administered for 28 days by gastric intubations. The levels of lipids, lipid-metabolizing enzymes, and lipoproteins were analyzed in the plasma and liver of both control and experimental animals. Rats treated with DMBA showed an increase (p?<?0.05) in levels of phospholipids, triglycerides, free fatty acids, total cholesterol, and free cholesterol and a decrease (p?<?0.01) in levels of ester cholesterol in the plasma and liver. The levels of very low-density lipoprotein and low-density lipoprotein increased (p?<?0.01), while the levels of high-density lipoproteins decreased (p?<?0.001) in plasma. Moreover, there was a significant increase (p?<?0.001) in activities of total lipase, cholesterol ester hydrolase, cholesterol ester synthase but with a sharp decrease (p?<?0.01) in lecithin cholesterol-acyl transferase and lipoprotein lipase in animals with mammary cancer. HEDF treatment caused the activity of these alterations in biochemical parameters to return to almost normal control levels. Also, histopathological analysis of the breast tissue was analyzed by hematoxylin and eosin staining, and results revealed the cytoprotective role of HEDF against mammary carcinogenesis. The effects of HEDF were found to be dose dependent in nature.     

Pulmonary antiallergic and antiinflammatory effects of a novel,orallyactive phosphodiesterase IV inhibitor (WAY-127093B) in guinea pigs and rats

Inflammation Research -     

Daily rhythms in PER1 within and beyond the suprachiasmatic nucleus of female grass rats (Arvicanthis niloticus)

Although circadian rhythms of males and females are different in a variety of ways in many species, their mechanisms have been primarily studied in males. Furthermore, rhythms are dramatically different in diurnal and nocturnal animals but have been studied predominantly in nocturnal ones. In the present study, we examined rhythms in one element of the circadian oscillator, the PER1 protein, in a variety of cell populations in brains of diurnal female grass rats. Every 4 h five adult female grass rats kept on a 12-h light/dark (LD) cycle were perfused and their brains were processed for immunohistochemical detection of PER1. Numbers of PER1-labeled cells were rhythmic not only within the suprachiasmatic nucleus (SCN), the locus of the primary circadian clock in mammals, but also in the peri-suprachiasmatic region, the oval nucleus of the bed nucleus of the stria terminalis, the central amygdala, and the nucleus accumbens. In addition, rhythms were detected within populations of neuroendocrine cells that contain tyrosine hydroxylase. The phase of the rhythm within the SCN was advanced compared with that seen previously in male grass rats. Rhythms beyond the SCN were varied and different from those seen in most nocturnal species, suggesting that signals originating in the SCN are modified by its direct and/or indirect targets in different ways in nocturnal and diurnal species.     

鼻咽上皮癌变过程中端粒酶活性和端粒酶RNA的表达

目的 研究二亚硝基哌嗪（DNP）诱发大鼠鼻咽癌变过程中端料酶的表达规律。方法 以DNP诱导大鼠鼻咽癌：用PCR-ELISA和Nested RT-PCR检测DNP诱导大鼠鼻咽癌变不同阶段端粒酶活性和端料酶RNA的表达,同时作病理形态学检测。结果 DNP诱导大鼠鼻咽癌变过程中,端粒酶活性不断升高,端粒酶的变化与鼻咽癌变呈正相关,而且端粒酶中RNA表达先于端粒酶的表达。在大鼠鼻咽上皮细胞异型增生阶段即出现端粒酶的激活和端粒酶RNA的表达。结论 化学致癌物DNP诱导细胞癌变端粒酶的激活,且端粒酶的扩活和端粒酶RNA的表达是鼻咽上皮癌变的早发事件,与鼻咽癌的发生、发展有关。     

Immunoreactive luteinizing hormone releasing factor (LRF) in pituitary stalk plasma from female rats: effects of stimulating diencephalon, hippocampus and amygdala.

1. Previous studies on the effect of preoptic and median eminence stimulation on the immunoreactive LRF content of pituitary stalk blood from pro-oestrous rats have been extended. Stimulation of the suprachiasmatic nuclei and anterior hypothalamic area produced increments in LRF which were 66 and 18% respectively, of that produced by preoptic stimulation, and 38 and 9%, respectively, of that produced by stimulation of the median emience. Stimulation of the amygdala and hippocampus had no effect. 2. The LRF response was not affected significantly when preoptic stimulation was accompanied by stimulation of the hippocampus. 3. In animals subjected to section of the dorsal afferents of the diencephalon, the LRF response to preoptic stimulation was similar to that in intact rats. However, the facilitatory effect of oestrogen on the LRF response to preoptic stimulation was significantly reduced in the roof sectioned compared with intact animals. The post-operative resumption of oestrous cycles was delayed but not abolished by dorsal deafferentation.     

Altered expression of UPIa,UPIb, UPII,and UPIIIa during urothelial carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)nitrosamine in rats

In normal urothelium, superficial umbrella cells express four major integral membrane proteins, uroplakins UPIa, UPIb, UPII, and UPIIIa, which compose urothelial plaques. In the apical plasma membrane, urothelial plaques form microridges. During neoplastic changes, microridges are replaced by microvilli, while uroplakin expression is retained. We correlated individual uroplakin expression with apical plasma membrane structure, cytokeratin 20 expression, and urothelial cell proliferation (Ki-67). Male Wistar rats were treated with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water, which caused flat hyperplasia with mild dysplasia, low-grade papillary urothelial carcinoma, invasive low- and high-grade papillary urothelial carcinoma and invasive squamous cell carcinoma with extensive keratinization, grade 2. During urothelial carcinogenesis, UPII expression was the most decreased in all urothelial lesions, while UPIa, UPIb, and UPIIIa expression was differently altered in different types of lesions. Superficial cells were covered with microvilli and ropy ridges, while microridges were disappearing. The expression of cytokeratin 20 was decreased and limited to superficial urothelial cells. Proliferation indices were increased, except for invasive squamous cell carcinoma with extensive keratinization. Our results indicate that during urothelial carcinogenesis the expression of UPII is diminished, suggesting that UPIb/UPIIIa heterodimer can still be formed, while heterodimer UPIa/UPII formation is disrupted. Correlation between decreased level of UPII expression and changed apical plasma membrane structure suggests that diminished expression of UPII hinders the urothelial plaque formation.     

The effects of tualang honey on female reproductive organs,tibia bone and hormonal profile in ovariectomised rats - animal model for menopause

Background

Honey is a highly nutritional natural product that has been widely used in folk medicine for a number of therapeutic purposes. We evaluated whether Malaysian Tualang honey (AgroMas, Malaysia) was effective in reducing menopausal syndrome in ovariectomised female rats; an animal model for menopause.

Methods

The rats were divided into two control groups and three test groups. The control groups were sham-operated (SH) and ovariectomised (OVX) rats. The SH and OVX control rats were fed on 0.5 ml of distill water. The rats in the test groups were fed with low dose 0.2 g/kg (THL), medium dose, 1.0 g/kg (THM) and high dose 2.0 g/kg (THH) of Tualang honey in 0.5 ml of distill water. The administration was given by oral gavage once daily for 2 weeks. The reproductive organs (uterus and vagina), tibia bone and aorta were taken for histopathological examination while serum for hormonal assays.

Results

Administration of Tualang honey for 2 weeks to ovariectomised rats significantly increased the weight of the uterus and the thickness of vaginal epithelium, restored the morphology of the tibia bones and reduced the body weight compared to rats in the ovariectomised group. The levels of estradiol and progesterone, in honey treated groups were markedly lower than that in the OVX group. At low doses (0.2 g/kg; THL group) of Tualang honey there was an increased in serum free testosterone levels compared to OVX group (P < 0.01). Progesterone concentrations was significantly decreased in the OVX group as compared to SHAM group (P < 0.05).

Conclusions

Tualang honey was shown to have beneficial effects on menopausal (ovariectomised) rats by preventing uterine atrophy, increased bone density and suppression of increased body weight. Honey could be an alternative to HRT.

     

Ocular expression of vascular cell adhesion molecule (VCAM-1) in 2-butoxyethanol-induced hemolysis and thrombosis in female rats.

We demonstrated previously that exposure of rats to 2-butoxyethanol (BE) was associated with morphological changes in red blood cells, hemolytic anemia, and disseminated thrombosis and infarction in different organs including the eyes. In order to elucidate the mechanism of thrombosis formation, we examined in this study the histology and immunohistochemical expression of vascular cell adhesion molecule-1 (VCAM-1), endothelial intercellular adhesion molecule-1 (ICAM-1), and P-selectin in the eyes of the female F344 rat exposed to 2, 3, or 4 daily doses of BE/250 mg/kg body weight. In this BE hemolysis and thrombosis model, positive VCAM-1 expression occurred only in eyes of rats exposed to 3 and 4 doses and was localized in the iris (epithelium lining the posterior surface, anterior mesenchymal epithelium), ciliary processes (lining epithelium, stromal cells), and retina (hypertrophic retinal pigment epithelium). Only weak immunolabeling was seen in eyes exposed to 2 doses. The appearance of VCAM-1 immunostaining correlated with the development of thrombosis located in the same structures. No change in ICAM-1 or P-selectin expression was seen. This immunolabeling distribution suggests that VCAM-1 functions in the pathogenesis of BE-related thrombosis by promoting adhesion of erythrocytes to the endothelium.     

Six-month effects of the Groningen active living model (GALM) on physical activity, health and fitness outcomes in sedentary and underactive older adults aged 55-65

OBJECTIVE: To determine the effects on energy expenditure, health and fitness outcomes in sedentary older adults aged 55-65 after 6-month participation in the GALM program. METHODS: In three Dutch communities, subjects from matched neighbourhoods were assigned to an intervention (n = 79) or a waiting-list control group (n = 102). The GALM program consisted of fifteen 60 min sessions once a week emphasising moderate-intensity recreational sports activities. RESULTS: The intervention group showed significant increases in energy expenditure for recreational sports activities, other leisure-time physical activity, health indicators, and perceived and performance-based fitness. Contrary to our expectations, the same increases were found for the control group. Consequently, only significant between-group differences, favouring the intervention group, were obtained for sleep, diastolic blood pressure, perceived fitness score and grip strength. CONCLUSION: The increases in energy expenditure for physical activity from the GALM program, especially for the more intensive recreational sports activities, look promising and are in line with the expected amounts necessary to improve health. Further research is needed to evaluate long-term effects of participation in the GALM program. PRACTICE IMPLICATIONS: These results underline that GALM can be considered successful in stimulating leisure-time physical activity and improving health and fitness in older adults.     

Twelve-month effects of the Groningen active living model (GALM) on physical activity, health and fitness outcomes in sedentary and underactive older adults aged 55-65

OBJECTIVE: To determine the effects on energy expenditure, health and fitness outcomes after 12 months of GALM. METHODS: Subjects from matched neighbourhoods were assigned to an intervention (IG) (n=79) or a waiting-list control group (CG) (n=102). During the 12 months the IG attended two series of 15 moderately intensive GALM sessions once a week and the CG attended one series after a 6-month waiting-list period. RESULTS: Significant time effects were found for energy expenditure for recreational sports activities (EE(RECSPORT)), other leisure-time physical activity (EE(LTPA)) and total physical activity (EE(TOTAL)). EE(RECSPORT) increased over 12 months for both groups while the significant time x group interaction for EE(LTPA) revealed that the CG continuously increased over 12 months and the IG improved in the first 6 months but decreased from 6 to 12 months. Further significant time effects were found for performance-based fitness but no group effects. CONCLUSION: Participation in GALM improved EE(RECSPORT) after 12 months, which was reflected in increases in performance-based fitness. The increase in EE(LTPA) seemed to be a short-term effect (6 months), which may explain the lack of improvement in other health indicators. PRACTICE IMPLICATIONS: To further increase EE(LTPA), more attention should be paid to behavioural skill-building during the GALM program.     

Metabolic rate in female Culex tarsalis (Diptera: Culicidae): age, size, activity, and feeding effects

We used flow-through respirometry on female mosquitoes to observe individual ventilatory pattern and to measure metabolic rate at rest, during activity and after a blood-meal. At rest, young adult females of the species Culex tarsalis ventilated cyclically with an average VCO2 of 6.5 nl/min and frequency of 45 mHz. Both resting metabolic rate and body mass of females increased between emergence and 4 d, but only body mass continued to increase until 12 d. Mating status had no effect on the body mass or resting metabolic rate of the females. Both lipid and carbohydrate stores strongly increased during the first week of adult life, in particular between emergence and 4 d, in which lipid mass increased 8.3-fold and carbohydrate mass increased 3.6-fold. Hourly metabolic rate after a blood or sugar meal was measured over a 6-d period in two groups of 14 females. Sugar-fed mosquitoes remained calm during the day and had nocturnal increases in metabolic rate associated with flight activity. Blood feeding elicited a specific dynamic action lasting approximately 55 h, at the peak of which metabolic rate of the blood-fed females was twice that of the sugar-fed group. Eggs were laid on the third night. The increase in metabolic rate presumably reflected the cost of blood digestion and egg production. The females were not active during digestion, so that although their metabolic rate was increased, the overall energy expenditure of the blood-fed group was not very different from that of the sugar-fed group.