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Biomedical subjects

O P Almeida

Publications and source records attributed to O P Almeida.

At least 19 recordsLinked to original sources
PubMed2002

Evaluation of argyrophilic nucleolar organizer regions in oral tumor progression.

The aim of this study was to compare the presence of nucleolar organizer regions (NORs) in normal oral mucosa, dysplasia and microinvasive carcinoma. All histological specimens were reviewed according to the modified classification and staging system for oral leukoplakia described by van-der-Waal et al. [Oral Oncol. 36 (2000) 264]. NOR quantification was performed with an image analyzer after staining by the argyrophilic nucleolar region technique. The morphometric results were statistically different for normal mucosa, dysplasia and microinvasive carcinoma. It was concluded that an increase of NOR activity follows the disease progression and may reflect the degree of cellular proliferation and malignancy.

Disease Progression↗
PubMed2002

Immunohistochemical distinction of high-grade mucoepidermoid carcinoma and epidermoid carcinoma of the parotid region.

The correct diagnosis of high-grade mucoepidermoid (MEC), which is composed of solid islands of intermediate and squamous cells, may be challenging, due to its similarity to other tumours, mainly with squamous cell carcinoma (SCC). The present report employed immunohistochemical technique against different cytokeratins (CKs), in order to differentiate these two entities. : Six high-grade MEC and six SCC of the parotid region, retrieved from the files of both Oral Pathology Department of the School of Dentistry of University of São Paulo and Pathology Department of A.C. Camargo Hospital, were submitted immunohistochemical technique against Cks 7,8, 10, 13, 14 and 19. : High-grade MEC was positive for Cks 7, 8, 13, 14 and 19. The cases of SCC showed strong positivity for CK14, and CK10 was present only in focal areas. Our results highlight the use of CKs (especially CK14) to differentiate high-grade MEC and SCC.

Adult↗
PubMed2002

Basaloid squamous carcinoma of oral cavity: a histologic and immunohistochemical study.

Basaloid squamous carcinoma (BSC) is an aggressive variant of squamous cell carcinoma (SCC) with a predilection for the upper aerodigestive tract. In the English literature, approximately 40 cases of BSC have been described in the oral cavity. BSC has frequently been confused with adenoid cystic carcinoma (ACC), basal cell adenocarcinoma, and undifferentiated SCC. The purpose of the investigation was to examine the histological features and immunohistochemical expression of differentiation-related substances, including cytokeratin (CK) subtypes, vimentin, S-100, chromogranin, laminin, and type IV collagen, for the characterization of biological features of these tumours. We studied three cases of BSC of the oral cavity, three cases of ACC, and one case of basal cell adenocarcinoma. Well-differentiated and undifferentiated SCCs were also studied for comparison. The BSCs showed many histopathologic similarities to cases previously reported. Among the CK subtypes analyzed, CK14 was the only subtype expressed by all basaloid cells of BSC. Potentially useful for the differential diagnosis was the finding of CKs 7 and 19 expression in the basaloid cells of ACC, and CKs 7 and 8 in basal cell adenocarcinoma. In BSCs, laminin and type IV collagen were found in the microcystic spaces between basaloid cells, but neither ACCs nor basal cell adenocarcinoma showed this feature. These data suggest that immunohistochemical findings are helpful in distinguishing BSC of the oral cavity from other histopathologically similar tumours.

Adenocarcinoma↗
PubMed2002

Testosterone stimulates proliferation and inhibits interleukin-6 production of normal and hereditary gingival fibromatosis fibroblasts.

Hereditary gingival fibromatosis (HGF) is a rare oral condition characterized by a slow and progressive enlargement of the gingiva, involving both the maxilla and mandible. In vitro, HGF fibroblasts demonstrate a proliferative index significantly higher than fibroblasts from normal gingiva (NG). The objective of this study was to determine the effect of dihydrotestosterone on the proliferation of gingival fibroblasts derived from patients with HGF (n = 4) and from four healthy individuals. Additionally, we analyzed the effect of dihydrotestosterone on interleukin-6 (IL-6) production and determined the expression levels of androgen receptors in NG and HGF fibroblasts. Gingival fibroblasts from NG and HGF were incubated with increasing concentrations of dihydrotestosterone with or without androgen blockers, and cultured for 24 h, and the proliferation index was determined by automated cell counter. IL-6 production, in this system, was quantified using a "capture" enzyme-linked immunosorbent assay (ELISA). Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to measure the mRNA expression of androgen receptors. The results indicated that dihydrotestosterone simultaneously downregulates the production of IL-6 and upregulates the cell proliferation. Finasteride and cyprosterone acetate, two anti-androgens, partially reversed these effects. Androgen receptor mRNA expression was identified in both NG and HGF fibroblasts; however, the levels in NG were higher than those observed in HGF. These results show that testosterone coordinates the proliferation and production of IL-6 of normal and HGF fibroblasts.

5-alpha Reductase Inhibitors↗
PubMed2002

Morphological evaluation of combined effects of cyclosporin and nifedipine on gingival overgrowth in rats.

It has previously been shown that, while cyclosporin A (CsA) and nifedipine both cause gingival overgrowth in the rat, the combined use of these drugs increases the severity of overgrowth. The aim of this study was to describe the histometry and densities of fibroblasts, collagen fibers and vessels in the gingival tissue of rats that were treated with CsA and nifedipine, either alone or in combination. Rats were treated for 60 days with a daily subcutaneous injection of 10 mg/kg body weight of CsA and/or with 50 mg/kg body weight of nifedipine added to the chow. The results confirmed that CsA causes a more severe overgrowth than nifedipine, and that the combined use of these drugs increases the overgrowth severity. All the rat groups that were studied showed that, as the severity of overgrowth increased, there was a parallel increase in fibroblasts and collagen, and a decrease in vessel content. Therefore, independently of whether the gingival overgrowth was caused by CsA alone, nifedipine alone, or both treatments in combination, the fibroblast and collagen density increased in parallel with the severity of the overgrowth.

Analysis of Variance↗
PubMed2002

Solitary fibrous tumour of the mouth: report of two cases involving the tongue and cheek.

We describe two additional cases of solitary fibrous tumour (SFT) affecting the mouth. SFT is very uncommon in the oral cavity and we found only 14 cases reported in the literature. Our two cases were well circumscribed, slow growing tumours that, after surgical removal, did not recur. Case 1 was a 3 cm nodule on the right cheek. Hypo and hypercellular adjacent areas were mainly patternless, and the stroma was formed by thin collagen fibrils. Case 2 was a 4.8 cm mass in the anterior portion of the tongue. Microscopically it was formed by spindle cells embedded in a vascularized sclerotic collagen matrix. Some areas were hypercellular with scarce collagen fibrils. The immunohistochemical findings were similar in both cases, with strong immunoreactivity for vimentin, CD34, bcl-2, focal positivity for Ki-67 and negativity for other immunomarkers. Based on these clinical, microscopical and immunohistochemical features the final diagnosis of these two cases was SFT. Diagnosis of SFT is difficult and, although uncommon, it should be considered in the differential diagnosis of oral soft tissue tumours.

Adult↗
PubMed2002

APOE-epsilon4 and APOE -491A polymorphisms in individuals with subjective memory loss.

The accurate clinical diagnosis of Alzheimer's disease can only be made with a high degree of certainty in specialized centres. The identification of predictive or diagnostic genetic factors may improve accuracy of disease prediction or diagnosis. One major genetic risk factor, the epsilon4 allele of the apolipoprotein E gene, is universally recognised. We have recently shown that the A allele of the apolipoprotein E, -491A/T promoter polymorphism is also an important risk factor for Alzheimer's disease in an Australian population. We designed the present study to investigate the association between apolipoprotein E genotype, -491A/T polymorphism, plasma apoE levels and the subjective experience of memory decline among 98 subjects and 49 age, gender and education-matched normal controls. An increased frequency of the epsilon4 allele of apolipoprotein E was significantly associated with the 'memory complainers' group (OR = 2.35, P = 0.02) as was the A allele of the -491A/T polymorphism (OR = 2, P = 0.02). Among all subjects, only seven individuals were homozygous for both of these alleles, and six of these seven individuals belonged to the 'memory complainers' group. This sub-group also had relatively elevated plasma apolipoprotein E levels (P < 0.01) and tended to score lower on the Mini-Mental State Examination (MMSE) and Cambridge Cognition Test. These data suggest that the epsilon4 allele of apolipoprotein E and the -491A allele are over-represented among individuals who complain of memory difficulties. Follow-up studies should clarify whether these genotypes and phenotypes are useful in the prediction and/or diagnosis of Alzheimer's disease.

Alzheimer Disease↗
PubMed2002

Relation between medial temporal atrophy and functional brain activity during memory processing in Alzheimer's disease: a combined MRI and SPECT study.

OBJECTIVE: To investigate the relation between atrophy of the hippocampal region and brain functional patterns during episodic memory processing in Alzheimer's disease. PATIENTS AND METHODS: Whole brain structural magnetic resonance imaging (MRI) data and single photon emission computed tomography (SPECT) measures of regional cerebral blood flow (rCBF) were obtained during a verbal recognition memory task in nine subjects with mild Alzheimer's disease and 10 elderly healthy controls. Using the statistical parametric mapping approach, voxel based comparisons were made on the MRI data to identify clusters of significantly reduced grey matter concentrations in the hippocampal region in the Alzheimer patients relative to the controls. The mean grey matter density in the voxel cluster of greatest hippocampal atrophy was extracted for each Alzheimer subject. This measure was used to investigate, on a voxel by voxel basis, the presence of significant correlations between the degree of hippocampal atrophy and the rCBF SPECT measures obtained during the memory task. RESULTS: Direct correlations were detected between the hippocampal grey matter density and rCBF values in voxel clusters located bilaterally in the temporal neocortex, in the left medial temporal region, and in the left posterior cingulate cortex during the memory task in the Alzheimer's disease group (p < 0.001). Conversely, measures of hippocampal atrophy were negatively correlated with rCBF values in voxel clusters located in the frontal lobes, involving the right and left inferior frontal gyri and the insula (p < 0.001). CONCLUSIONS: Hippocampal atrophic changes in Alzheimer's disease are associated with reduced functional activity in limbic and associative temporal regions during episodic memory processing, but with increased activity in frontal areas, possibly on a compensatory basis.

Alzheimer Disease↗
PubMed2001

Efficacy of estradiol for the treatment of depressive disorders in perimenopausal women: a double-blind, randomized, placebo-controlled trial.

BACKGROUND: Results of previous studies suggest that estrogen improves somatic and mild depressive symptoms experienced by perimenopausal women. This study investigated the efficacy of 17beta-estradiol for the treatment of clinically significant depressive disorders in endocrinologically confirmed perimenopausal women. METHODS: Perimenopausal women (aged 40-55 years, with irregular menstrual periods and serum concentrations of follicle-stimulating hormone >25 IU/L), meeting criteria for major depressive disorder, dysthymic disorder, or minor depressive disorder, according to DSM-IV, were randomized to receive transdermal patches of 17beta-estradiol (100 microgram) or placebo in a 12-week, double-blind, placebo-controlled study. A 4-week washout period followed the 12-week treatment phase. Outcome measures were the Montgomery-Asberg Depression Rating Scale and Blatt-Kupperman Menopausal Index scores. RESULTS: Fifty women were enrolled in the study; 26 met DSM-IV criteria for major depressive disorder, 11 for dysthymic disorder, and 13 for minor depressive disorder. Remission of depression was observed in 17 (68%) women treated with 17beta-estradiol compared with 5 (20%) in the placebo group (P =.001). Subjects responded similarly to estradiol treatment, regardless of DSM-IV diagnosis. Patients treated with estradiol sustained antidepressant benefit of treatment after the 4-week washout period, although somatic complaints increased in frequency and intensity. Treatment was well tolerated and adverse events were rare in both groups. CONCLUSION: Transdermal estradiol replacement is an effective treatment of depression for perimenopausal women.

Administration, Cutaneous↗
PubMed2001

Clinical characteristics of individuals with subjective memory loss in Western Australia: results from a cross-sectional survey.

Subjective memory complaint is common in later life. Its relationship to future risk of dementia is unclear, although many reports have found a positive association. We designed the present cross-sectional survey to investigate the clinical features associated with subjective memory impairment. One hundred and eight volunteers and 38 non-complainers acting as age-matched controls were recruited. Eleven subjects with memory complaints were excluded because of prior stroke or low MMSE score. The CAMCOG was used to measure cognition; complainers had significantly lower scores (p<0.001). Univariate analysis showed that complainers had greater prevalence of depression, anxiety, insomnia, psychotic phenomenon, difficulties with ADL and word-finding difficulties. The frequency distribution of the apolipoprotein E epsilon4 allele was similar for both groups (p=0.469). Logistic regression analysis indicated that CAMCOG scores (p=0.002) and word-finding difficulty (p=0.002) were independently associated with memory complaints. These results show that memory complainers have worse cognitive performance than non-complainers and support the findings of other studies that suggest that subjective memory loss may be a reliable indicator of cognitive decline.

Activities of Daily Living↗
PubMed2001

Antidepressant efficacy and safety of low-dose sertraline and standard-dose imipramine for the treatment of depression in older adults: results from a double-blind, randomized, controlled clinical trial.

This study compared the efficacy and tolerability of 150 mg/day imipramine and 50 mg/day sertraline for the treatment of a major depressive episode (DSM-IV) in older adults (N = 55) in an 8-week, randomized, double-blind, controlled clinical trial. Intention-to-treat analysis (last observation carried forwards) showed a reduction of 50% or more on the baseline scores of the Montgomery-Asberg Rating Scale (MADRS) in 60.7% and 55.6% of patients receiving imipramine and sertraline, respectively (p = .698). Full remission of symptoms (MADRS < 9) was observed in 50.0% and 51.8% of patients, respectively (p = .891). Side effects were more frequent among patients treated with imipramine (86.7%) than among patients treated with sertraline (42.1%) (p = .008). Dropout rates were high in both groups (46.4% and 29.6% respectively, p =.200). These results indicate that imipramine and sertraline are equally effective for the treatment of major depression in later life, although adverse reactions are more frequent among subjects treated with imipramine than with sertraline.

Aged↗
PubMed2001

Simultaneous occurrence of lymphoepithelial cysts, cytomegalovirus and mycobacterial infections in the intraparotid lymph nodes of a patient with AIDS.

We report the unusual simultaneous occurrence of lymphoepithelial cysts, cytomegalovirus (CMV) and mycobacterial infections in the intraparotid lymph nodes of a 52-year-old AIDS patient who died of disseminated mycobacteriosis. Although cytomegalovirosis is a common finding in the salivary glands of HIV patients, the association of CMV inclusions with lymphoepithelial cyst (LC) has not been previously reported. Parotid mycobacterial infection is an uncommon finding, despite its usual disseminated presentation in HIV patients. These data emphasize that in immunosuppressed patients, simultaneous diseases of the parotid gland may occur and should be considered for diagnosis and treatment.

AIDS-Related Opportunistic Infections↗
PubMed2001

Morphometric evaluation of gingival overgrowth and regression caused by cyclosporin in rats.

Cyclosporin A is a selective immunosuppressant, used in organ transplants to prevent graft rejection. Cyclosporin A can cause various side effects including gingival overgrowth. The aim of this work was to evaluate gingival overgrowth of rats treated daily with 10 mg/kg bodyweight of cyclosporin A for 60 days, as well as the regression after the interruption of treatment. All rats treated with cyclosporin A developed gingival overgrowth, with increased thickness of the epithelium, height and width of the connective tissue. The density of fibroblasts and collagen fibers also increased. Five to 90 days after the interruption of treatment with cyclosporin A, there was a progressive reduction of the gingival volume and of collagen fibers and fibroblast densities. The reduction was more pronounced in the initial periods and after 90 days did not return to the normal values.

Animals↗