PubMed Health⌕ Search

Biomedical subjects

R C Borra

Publications and source records attributed to R C Borra.

10 recordsLinked to original sources
PubMed2005

Gene expression profiles reveal that DCN, DIO1, and DIO2 are underexpressed in benign and malignant thyroid tumors.

To investigate the molecular events involved in the pathogenesis and/or progression of thyroid tumors, we compared the gene expression profiles of three thyroid carcinoma cell lines, which represent major tumor subtypes of thyroid cancer and normal thyroid tissue. Using cDNA array methodology, we investigated the expression of 1807 open reading frame expressed sequence tags (ORESTES), selected from head and neck tumor libraries generated through the Brazilian Human Cancer Project-LICR/FAPESP. We found that 505 transcripts were differentially expressed in the thyroid carcinoma cell lines. Using a more stringent criterion, transcripts underexpressed or overexpressed more than fivefold in 1 of 3 or 3 of 3 carcinoma cell lines, a list of 55 ESTs were detected. Five candidate genes were further validated by quantitative polymerase chain reaction (qPCR) in an independent set of 52 thyroid tumors and 22 matched normal thyroid tissues. DCN was found underexpressed in a high percentage of the follicular thyroid adenomas, follicular thyroid carcinomas, and follicular variant of papillary thyroid carcinomas. DIO1 and DIO2 were underexpressed in nearly all papillary thyroid carcinomas. These genes not only could help to better define a tumor signature for thyroid tumors, but may, in part, also become useful as potential targets for thyroid tumor treatment.

Adenocarcinoma, Follicular↗
PubMed2005

Differential gene expression assessed by cDNA microarray analysis in breast cancer tissue under tamoxifen treatment.

Our purpose was to identify tamoxifen (TAM) responsive genes after 30 days of TAM treatment in tumor tissues obtained from women with breast cancer using microarray expression analysis. In our study, we identified 12 candidates to be considered as tamoxifen-modulated genes. Among them, we selected two candidates the TEGT BI-1 (testis enhanced gene transcript Bax Inhibitor-1) and the CD63 gene in order to further confirm their differential expression under tamoxifen effects. We observed that both were down-regulated in tumor tissues of patients during TAM treatment. TEGT is able to inhibit the expression of Bax, which is known to promote apoptosis. On the other hand, CD63 encodes a cell membrane protein and it seems to be involved in mechanisms of platelet activation, cell adhesion and cell motility. We therefore hypothesize that TAM would be able to modulate tumor growth by down-regulating genes involved in mechanisms such as cell cycle control, tumor invasion and metastasis.

Breast Neoplasms↗
PubMed2004

FTY720 impairs necrosis development after ischemia-reperfusion injury.

Ischemia-reperfusion (IR) injury is a common early feature that contributes to graft damage by impairing resident cell function. Our previous results showed that IR injury impaired renal function, by causing extensive tubular necrosis and increasing MHC class II and ICAM-1 molecule expression by mesangial cells (MC). MCs are likely candidates to come into close contact with immune cells such as monocytes or lymphocytes. It has been suggested that under inflammatory circumstances, there is increased MC expression of MHC class II, of adhesion molecules (such as ICAM-1), of cytokines receptors, and of molecules associated with cellular death (apoptosis). The immunosuppressive properties of FTY720 have been shown in clinical and experimental situations. It has also been shown to be protective against IR injury in rats. We sought to evaluate the role of FTY720 in a murine IR model by measuring renal function, tubular necrosis, and surface molecule expression by cultured mesangial cells. Intravenous administration of FTY720 (1 mg/kg) immediately before IR induction did not improve the short-term (24 hours) outcome of renal function or reduced MHC class II and ICAM-1 surface molecule expression. However, there was a decreased percentage of tubular necrosis in mice treated with FTY720 (51.3% +/- 1.6%) compared with vehicle-treated mice (66% +/- 5.5%). These results suggest a protective role of FTY720 in an IR injury model. More studies are required to identify the mechanisms involved in the protective activity of FTY720 in the IR injury model.

Analysis of Variance↗
PubMed2004

Canine paracoccidioidomycosis.

Paracoccidioidomycosis (PCM) is a severe disease caused by the dimorphic fungus Paracoccidioides brasiliensis, which is characterized by granulomatous pulmonary and systemic lesions, affecting mainly men between 20 and 60 years of age. Reports of PCM disease in animals are rare, but the disease has been described in armadillos. On the other hand, PCM infection of domestic and wild animals detected by serological or cutaneous tests in the absence of apparent disease has been frequently reported. We present here the case of a female adult Doberman that developed cervical lymphadenomegaly. Histopathological examination of a cervical biopsy specimen revealed active PCM, with an epithelioid, granulomatous inflammation containing numerous yeast-like, multiple budding fungal forms. The diagnosis of PCM was confirmed by immunohistochemistry using a specific antibody anti-gp43 and by nested PCR using primers for the amplification of the gp43 gene region. This is the first report of PCM disease occurring in a dog, an animal that has been shown to play an important role in the natural history of North American blastomycosis.

Animals↗
PubMed2004

The Th1 /Th2 immune-type response of the recurrent aphthous ulceration analyzed by cDNA microarray.

BACKGROUND: The reduced ability to activate oral tolerance plays a role in the pathogenesis of some gastrointestinal inflammatory diseases. This activation may reflect a preferential reduction of a T-helper (Th)2- or Th3-type response. In recurrent aphthous ulceration (RAU), genetic and environmental factors may contribute to low tolerance, permitting a cytotoxic reaction against the oral epithelium. The cytokine profile has not permitted the definition of RAU as resulting from enhanced Th1 or Th2 responses. A cDNA microarray study would allow the identification of differentially expressed genes and provide a basis for classification of the immune response. METHODS: The cDNA from 29 samples of aphthae and from 11 samples of normal mucosa from aphthae-free volunteers were hybridized on microarray membranes with 1176 genes. RESULTS: Forty-one differentially expressed genes were identified, and a higher expression level of the Th1 gene cluster in RAU was found. CONCLUSIONS: Microarrays permitted us definition of the gene expression profile of the lesion and identify an increased Th1 activity in RAU lesions.

Adolescent↗
PubMed2002

Estrogen regulation of uterine genes in vivo detected by complementary DNA array.

INTRODUCTION: In the present study, our aim was to identify differentially expressed genes involved in estrogen actions at the endometrium level in rats. METHODS: Thirty adult rats were ovariectomized four days prior to drug administration for 48 days. Rats were divided in 2 groups: I, control and II, conjugated equine estrogens (CCE). Total RNA was isolated from uterus, and differential expression was analyzed by array technology and RT-PCR. RESULTS: A total of 32 candidate genes were shown to be upregulated or downregulated in groups I or II. Among them, differential expression was already confirmed by RT-PCR for IGFBP5, S12, c-kit, and VEGF, genes whose expression was up regulated during CCE therapy, and casein kinase II and serine kinase expression was the same level in both groups. CONCLUSION: We have demonstrated that cDNA array represents a powerful approach to identify key molecules in the estrogens therapy. A number of the candidates reported here should provide new markers that may contribute to the detection of target estrogen receptor. This information may also aid the development of new approaches to therapeutic intervention.

Algorithms↗
PubMed2002

Estrogen and selective estrogen receptor modulator regulation of insulin-like growth factor binding protein 5 in the rat uterus.

Insulin-like growth factor (IGF) binding protein 5 (IGFPB-5) is abundant in the uterus and is implicated in the sex steroid-induced growth of this tissue. The purpose of this study was to investigate the potential for modulation of the action of IGFPB-5 at the uterus level in the rat by estrogen and selective estrogen receptor modulators (SERMs). One hundred and twenty adult rats, 2-3 months of age, were included. Among them 100 animals were ovariectomized 4 days prior to the use of drugs for 48 days. Rats were divided into six groups: non-ovariectomized (group 1); ovariectomized (group 2); and those receiving conjugated equine estrogens, 50 microg/day (group 3), tamoxifen 250 microg/day (group 4), raloxifene 3 mg/kg (group 5) and toremifene 2.5 mg/kg (group 6). Total RNA was isolated from the uterus and IGFBP-5 mRNA levels were assessed by the semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Our results demonstrate that conjugated equine estrogens were able to up-regulate mRNA levels of the IGFBP-5 gene, while oophorectomy alone as well as associated with hormone therapy such as tamoxifen, raloxifene and toremifene resulted in down-regulation of uterine IGFBP-5 gene expression. The up-regulation of IGFBP-5 expression induced by estrogens suggests that, in vivo, the uterotrophic effects of estrogen replacement therapy are mediated, at least inpart, by the IGF pathways. On the other hand, the use of SERMs (tamoxifen, raloxifene and toremifene) was associated with severe down-regulation of this gene at the transcription level.

Animals↗
PubMed1997

p53 In biopsies of oral squamous cell carcinoma. A comparative study with a malignancy grading system.

The relationship between the histological grading of malignancy and p53 protein expression was studied in 40 biopsies of oral squamous cell carcinomas. An immunohistochemical analysis was carried out using the streptavidin method preceded by a treatment with citric acid in a microwave oven. All cases were classified according to the histological malignancy grading system proposed by Anneroth et al. (Scandinavian Journal of Dental Research 1987, 95, 229-249). The expression of p53 was found in 62.5% of the carcinomas studied. Positivity of p53 staining showed a correlation with the histological grade of malignancy and with the degree of keratinisation, nuclear polymorphism and number of mitoses.

Aged↗
PubMedDate not supplied

[Computer-assisted image processing for quantifying histopathologic variables in the healing of colonic anastomosis in dogs].

BACKGROUND: The authors present the experimental results of the computerized quantifying of tissular structures involved in the reparative process of colonic anastomosis performed by manual suture and biofragmentable ring. The quantified variables in this study were: oedema fluid, myofiber tissue, blood vessel and cellular nuclei. MATERIAL AND METHODS: An image processing software developed at Laboratório de Informática Dedicado à Odontologia (LIDO) was utilized to quantifying the pathognomonic alterations in the inflammatory process in colonic anastomosis performed in 14 dogs. The results were compared to those obtained through traditional way diagnosis by two pathologists in view of counterproof measures. The criteria for these diagnoses were defined in levels represented by absent, light, moderate and intensive which were compared to analysis performed by the computer. RESULTS: There was significant statistical difference between two techniques: the biofragmentable ring technique exhibited low oedema fluid, organized myofiber tissue and higher number of alongated cellular nuclei in relation to manual suture technique. CONCLUSION: The analysis of histometric variables through computational image processing was considered efficient and powerful to quantify the main tissular inflammatory and reparative changing.

Anastomosis, Surgical↗