First case of variant Creutzfeldt-Jakob disease in Canada.
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Biomedical subjects
Publications and source records attributed to C Bergeron.
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OBJECTIVES: The purpose of this study focused on cervical neuroblastoma (NB) was to assess the prognosis, define the most suitable methods of investigation, and evaluate risk factors for complications following primary surgery. METHODS: Between 1990 and 1999, we conducted two consecutive prospective multicentric studies (NBL90 and NBL94) on localized NB. Because the first study (1990-1994) found surgery-related morbidity and mortality, several surgical risk factors (i.e. adhesion to major vessels, size, friability, and dumb bell tumor) were defined and used prospectively as criteria of resectability in the second study (1994-1999). RESULTS: Of 617 cases included in the two studies, 43 involved cervical NB including 17 cervicothoracic tumors. With a median follow-up of 4 years, overall survival and event-free survival rates were 91 and 81%, respectively with no significant difference between cervical or cervicothoracic NB. Seventeen patients were included in the second study; surgery was used as the first line treatment in 11. Full pre-operative work-up was performed in eight patients, demonstrating one or more risk factors in three. The remaining three patients underwent emergency surgery with no pre-operative work-up or only ultrasound: two developed serious complications. All three patients presenting documented risk factors developed post-operative complications versus only two of the eight patients who presented no risk factor (n = 5) or were inadequately evaluated (n = 3) (P = 0.06). None of the five patients in whom full work-up demonstrated no risk factor had post-operative complications (P = 0.02). CONCLUSIONS: Cervical neuroblastoma has a favorable prognosis. Surgery is the treatment of choice but there is a risk of complications. Appropriate pre-operative work-up is mandatory to evaluate resectability. The surgical risk factors defined for our second study seem to be significant predictors of post-operative complications.
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BACKGROUND: In bronchial mucosa, T cells are in close association with fibroblasts. This cell contact raises the possibility of cross-talk between the two cell types through cytokines, such as interleukin-4 (IL-4). OBJECTIVE: We postulated that IL-4 may modulate collagen synthesis and degradation in the fibroblasts of asthmatics. METHODS: Bronchial fibroblasts from asthmatics (BAF) and normal controls (BNF) were stimulated with IL-4. Procollagen I gene expression and protein production were measured by real-time PCR, RT-PCR, and radioimmunoassay. The effect of IL-4 on the regulation of procollagen I (alpha1) promoter was studied through transient cell transfections. The implication of Sp1 and AP-1 in regulating IL-4-induced procollagen I (alpha1) production was determined. The effect of IL-4 on metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) production and gene expression was evaluated. RESULTS: Following IL-4 stimulation, there was a significant increase in the expression of mRNA of procollagen I (alpha1) by human bronchial fibroblasts of asthmatics and controls. IL-4 has a dose-response effect on mRNA, with a maximal effect at 5 ng/mL, as determined by real-time PCR. The maximal increase in procollagen I (alpha1) was observed at 6 h after IL-4 stimulation in both BNF and BAF. BAFs have a greater increase in the procollagen I (alpha1)/beta2 microglobulin ratio after 6 h of IL-4 stimulation (4.1 x 10-2+/-0.03 to 20.8 x 10-2+/-0.1) compared with BNF (2.9 x 10-2+/-0.006 to 9.2 x 10-2+/-0.08) (P=0.001). In transient transfection experiments, IL-4 increased promoter activity by threefold in BAF and BNF. Sp1 was up-regulated after IL-4 stimulation and AP-1 was down-regulated as shown by electrophoretic mobility shift assay. IL-4 decreased MMP-2 protein and mRNA levels, and did not alter TIMP-2 production. CONCLUSIONS: IL-4 positively regulates procollagen I (alpha1) transcription by direct promoter activation and increases the TIMP-2/MMP-2 ratio, thereby supporting the profibrotic effect of this cytokine. Thus, this study emphasizes that IL-4 may be considered as a link between inflammation and collagen deposition observed in asthmatic airways.
The phytochemistry and biological activity of Scutellaria lateriflora L. (American skullcap) which has been traditionally used as a sedative and to treat various nervous disorders such as anxiety was studied. In vivo animal behaviour trials were performed to test anxiolytic effects in rats orally administered S. laterifolia extracts. Significant increases in the number of entries into the center of an "open-field arena"; number of unprotected head dips, number of entries and the length of time spent on the open arms of the Elevated Plus-Maze were found. The identification and quantification of the flavonoid, baicalin in a 50% EtOH extract (40 mg/g) and its aglycone baicalein in a 95% EtOH extract (33 mg/g), as well as the amino acids GABA in H2O and EtOH extracts (approximately 1.6 mg/g) and glutamine in a H2O extract (31 mg/g), was performed using HPLC. These compounds may play a role in anxiolytic activity since baicalin and baicalein are known to bind to the benzodiazepine site of the GABAA receptor and since GABA is the main inhibitory neurotransmitter.
BACKGROUND: Resistance to conventional chemotherapy is a major clinical problem for ovarian cancer, and long-term survival for patients with advanced-stage disease is rare. Other therapeutic strategies, such as gene therapy, have been explored but several limitations exist, which include low viral vector transduction efficiency, host immune response to the vector, and vector toxicity. METHODS: We developed a cell-based therapy that exploits human mesothelial cells to deliver anticancer modalities for treatment of ovarian cancer. As a proof of concept, we genetically engineered mesothelial with the herpes simplex virus thymidine kinase/ganciclovir (HSVTK/GCV) system to deliver cytotoxicity to human ovarian cancer cells. This system is well characterized, and has been widely used in different gene-therapy based strategies. RESULTS: Our results demonstrate that HSVTK-modified mesothelial cells are sensitive to GCV killing in vitro and support the HSVTK bystander effect. Engineered mesothelial cells can deliver the HSVTK bystander effect to human ovarian cancer cell-lines, as well as to primary ovarian cancer cells. A significant reduction of tumor growth and prolongation of survival in s.c. and i.p. xenograft mouse models of ovarian cancer are obtained with as little as 1% of HSVTK-expressing mesothelial cells. Intraperitoneal administration of HSVTK-expressing mesothelial cells in an established mouse model of ovarian cancer results in a statistically significant prolonged survival of treated animals. Importantly, distribution studies showed that mesothelial cells localize preferentially to tumor sites. DISCUSSION: Our study demonstrates the feasibility of using a mesothelial cell-based therapy for treatment of ovarian cancer, and suggests that this strategy should be further explored.
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Pick's disease (PiD) is characterized by the deposition of tau protein as three-repeat tau Pick bodies, whereas progressive supranuclear palsy (PSP) involves the deposition of four-repeat tau neurofibrillary tangles. PSP is associated with the tau H1 haplotype. The authors investigated a possible association between PiD and the tau H1 or H2 haplotype. There was no difference between the tau H2 haplotype or H2H2 genotype frequency in PiD cases and control subjects. No tau mutations were identified in pathologically typical cases of PiD, with antibody 12-E8-negative Pick bodies.
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Estrogens act through specific receptors located in the nuclei of epithelial and stromal cells of the endometrium. Estrogens stimulate the synthesis of these receptors and the progesterone inhibits their synthesis. Estrogens induce the proliferation of the mucosa during the proliferative phase. They also stimulate the synthesis of receptors for the progesterone, which is a prerequisite for progesterone activity. Hyperplasias most of the time do not contain cytological atypia and are developed under a hyperestrogenic background. They contain receptors for estrogen and progesterone, and are able to respond to progestogens. Hyperplasias with cytological atypia are precancerous lesions, associated with an hyperestrogenic or atrophic background. In the later case, they may be focal and are better diagnosed by hysteroscopy. They are best managed by simple hysterectomy. Progesterone may be used if the patient desires to conceive. Endometrial cancers are either associated with an hyperestrogenic or atrophic background. In the later case, they are often of serous or clear cell type. Endometrial effects of antiestrogens are known only for tamoxifene. Tamoxifene has an atrophic effect but sometimes may induce an estrogenic stimulation of the endometrial mucosa through the alpha and beta estrogenic receptors. Polyp is the most frequent abnormality diagnosed but endometrial cancer is significantly more frequently diagnosed than in a control population. It is well differentiated and does not modify the survival of the patient.
AIMS: To determine the morphological and immunohistochemical profile of retiform Sertoli-Leydig cell tumours and to compare the observed profile with that of adult rete ovarii. METHODS AND RESULTS: Nineteen retiform Sertoli-Leydig cell tumours were studied, eight by immunohistochemistry, and five examples of rete ovarii from adult females were also evaluated immunohistochemically. The patients ranged in age from 3 to 74 years with a mean age of 31 years. Four patients were virilized and had an abdominal mass; two were virilized with amenorrhoea and two had amenorrhoea alone. Eight presented with an abdominal mass and one patient was pregnant. Two tumours were incidental findings. Information on stage was available in 16 patients: 14 tumours were stage 1, one was stage 2, and one was stage 3. Fifteen tumours were of intermediate differentiation and four were poorly differentiated. Papillary structures were evident grossly in four cases. Microscopically, all cases had a retiform pattern in addition to varying quantities of sex cord, gonadal stromal and heterologous elements. Heterologous elements were present in 13 cases and consisted of hepatocytes (n = 7), mucinous epithelium (n = 7) and skeletal muscle (n = 2). Immunohistochemical evaluation of eight tumours showed a more intense positivity for keratin in the retiform areas, whereas the gonadal stromal component had a more intense expression of inhibin. Inhibin stains Leydig cells strongly and hepatocytes moderately. Rete ovarii epithelium was positive for keratin and vimentin in the five cases studied, and for inhibin in one case. Follow-up was available on 13 patients. Three tumours behaved in a malignant fashion: one each was stage 1, 2, and 3 at diagnosis. CONCLUSIONS: Immunohistochemistry is useful in distinguishing retiform Sertoli-Leydig cell tumours from other tumours that they may resemble. Inclusion of inhibin is essential in a panel of antibodies to evaluate these tumours. The clinical behaviour of these neoplasms cannot always be predicted from their morphology or clinical stage.
A working group supported by the Office of Rare Diseases of the National Institutes of Health formulated neuropathologic criteria for corticobasal degeneration (CBD) that were subsequently validated by an independent group of neuropathologists. The criteria do not require a specific clinical phenotype, since CBD can have diverse clinical presentations, such as progressive asymmetrical rigidity and apraxia, progressive aphasia, or frontal lobe dementia. Cortical atrophy, ballooned neurons, and degeneration of the substantia nigra have been emphasized in previous descriptions and are present in CBD, but the present criteria emphasize tau-immunoreactive lesions in neurons, glia, and cell processes in the neuropathologic diagnosis of CBD. The minimal pathologic features for CBD are cortical and striatal tau-positive neuronal and glial lesions, especially astrocytic plaques and thread-like lesions in both white matter and gray matter, along with neuronal loss in focal cortical regions and in the substantia nigra. The methods required to make this diagnosis include histologic stains to assess neuronal loss, spongiosis and ballooned neurons, and a method to detect tau-positive neuronal and glial lesions. Use of either the Gallyas silver staining method or immunostains with sensitive tau antibodies is acceptable. In cases where ballooned neurons are sparse or difficult to detect, immunostaining for phospho-neurofilament or alpha-B-crystallin may prove helpful. Methods to assess Alzheimer-type pathology and Lewy body pathology are necessary to rule out other causes of dementia and Parkinsonism. Using these criteria provides good differentiation of CBD from other tauopathies, except frontotemporal dementia and Parkinsonism linked to chromosome 17, where additional clinical or molecular genetic information is required to make an accurate diagnosis.
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OBJECTIVE: To analyze the association of polymorphisms in the tau gene with pathologically confirmed corticobasal degeneration (CBD). BACKGROUND: The authors previously described an extended tau haplotype (H1) that covers the human tau gene and is associated with the development of progressive supranuclear palsy (PSP). The authors now extend this analysis to CBD, a neurodegenerative condition with clinical and neuropathologic similarities to PSP. Like PSP, CBD is associated with accumulation of aggregates containing the 4-repeat isoforms of tau. Because of difficulty in diagnosis of CBD, the authors only analyzed cases with pathologically confirmed CBD. METHODS: The authors collected 57 unrelated, neuropathologically confirmed cases of CBD. Tau sequencing in these cases failed to show the presence of pathogenic mutations. Polymorphisms that spanned the tau gene were analyzed in all CBD cases and controls. RESULTS: Analyzing tau polymorphisms in CBD cases showed that the frequency of H1 and H1/H1 was significantly increased when analyzing all cases and when separating by country of origin. H1 frequency in all CBD cases was 0.921, compared with a control frequency of 0.766 (X(2) = 9.1, p = 0.00255 [1df], OR 3.56 [8.43 > CI 95% > 1.53]). The H1/H1 frequency was also significantly higher at 0.842 compared with 0.596 in age-matched controls (X(2) = 17.42, p = 0.00016, 2df), OR 3.61 [7.05 > CI 95% > 1.85]). CONCLUSIONS: The CBD tau association described here suggests that PSP and CBD share a similar cause, although the pathogenic mechanism behind the two diseases leads to a different clinical and pathologic phenotype.
We have created early-onset transgenic (Tg) models by exploiting the synergistic effects of familial Alzheimer's disease mutations on amyloid beta-peptide (Abeta) biogenesis. TgCRND8 mice encode a double mutant form of amyloid precursor protein 695 (KM670/671NL+V717F) under the control of the PrP gene promoter. Thioflavine S-positive Abeta amyloid deposits are present at 3 months, with dense-cored plaques and neuritic pathology evident from 5 months of age. TgCRND8 mice exhibit 3,200-4,600 pmol of Abeta42 per g brain at age 6 months, with an excess of Abeta42 over Abeta40. High level production of the pathogenic Abeta42 form of Abeta peptide was associated with an early impairment in TgCRND8 mice in acquisition and learning reversal in the reference memory version of the Morris water maze, present by 3 months of age. Notably, learning impairment in young mice was offset by immunization against Abeta42 (Janus, C., Pearson, J., McLaurin, J., Mathews, P. M., Jiang, Y., Schmidt, S. D., Chishti, M. A., Horne, P., Heslin, D., French, J., Mount, H. T. J., Nixon, R. A., Mercken, M., Bergeron, C., Fraser, P. E., St. George-Hyslop, P., and Westaway, D. (2000) Nature 408, 979-982). Amyloid deposition in TgCRND8 mice was enhanced by the expression of presenilin 1 transgenes including familial Alzheimer's disease mutations; for mice also expressing a M146L+L286V presenilin 1 transgene, amyloid deposits were apparent by 1 month of age. The Tg mice described here suggest a potential to investigate aspects of Alzheimer's disease pathogenesis, prophylaxis, and therapy within short time frames.
Metallothionein III (MT-III) is a functionally distinct member of the metallothionein family that displays neuroinhibitory activity and is involved in the repair of neuronal damage. Altered expression levels of MT-III have been observed in Alzheimer's disease (AD) which has led to suggestions that it could be a mitigating factor in AD-related neuronal dysfunction. However, conflicting results have been reported on this issue which may be due to methodological differences and/or sampling size. In the current study, we have assessed MT-III expression in a large number of AD cases through the quantification of mRNA as well as by immunohistochemistry and Western blotting using an MT-III specific antibody. The results of this comprehensive study indicate that the mononucleosome DNA encoding MT-III is occluded preventing transcription and that message levels are reduced by approximately 30%. In addition, protein levels were specifically decreased by approximately 55% in temporal cortex. These data support the conclusion that MT-III is significantly downregulated in AD and may contribute to the loss of its protective effects and/or repair functions that lead to an exacerbation of the pathogenic processes.
The aim of this six-centre, split-sample study was to compare ThinPrep fluid-based cytology to the conventional Papanicolaou smear. Six cytopathology laboratories and 35 gynaecologists participated. 5428 patients met the inclusion criteria (age > 18 years old, intact cervix, informed consent). Each cervical sample was used first to prepare a conventional Pap smear, then the sampling device was rinsed into a PreservCyt vial, and a ThinPrep slide was made. Screening of slide pairs was blinded (n = 5428). All non-negative concordant cases (n = 101), all non-concordant cases (n = 206), and a 5% random sample of concordant negative cases (n = 272) underwent review by one independent pathologist then by the panel of 6 investigators. Initial (blinded) screening results for ThinPrep and conventional smears were correlated. Initial diagnoses were correlated with consensus cytological diagnoses. Differences in disease detection were evaluated using McNemar's test. On initial screening, 29% more ASCUS cases and 39% more low-grade squamous intraepithelial lesions (LSIL) and more severe lesions (LSIL+) were detected on the ThinPrep slides than on the conventional smears (P = 0.001), including 50% more LSIL and 18% more high-grade SIL (HSIL). The ASCUS:SIL ratio was lower for the ThinPrep method (115:132 = 0.87:1) than for the conventional smear method (89:94 = 0.95:1). The same trend was observed for the ASCUS/AGUS:LSIL ratio. Independent and consensus review confirmed 145 LSIL+ diagnoses; of these, 18% more had been detected initially on the ThinPrep slides than on the conventional smears (P = 0.041). The ThinPrep Pap Test is more accurate than the conventional Pap test and has the potential to optimize the effectiveness of primary cervical cancer screening.
OBJECTIVES: To determine the endometrial safety of oral 17beta-oestradiol combined continuously with dydrogesterone in preventing endometrial proliferation. METHODS: The low dose group comprised three 52-week (13 cycles of 28 days) studies (two of which were double blind) using a 17beta-oestradiol dose of 1 mg daily combined with dydrogesterone 2.5, 5, 10 or 20 mg daily. The high dose group comprised two 24-week double-blind studies using a 17beta-oestradiol dose of 2 mg daily combined with dydrogesterone 2.5, 5, 10 or 15 mg daily. Endometrial safety was verified by aspiration endometrial biopsies. Inadequate progestational response was defined as proliferative endometrium, endometrial polyp, hyperplasia and carcinoma. RESULTS: Data was evaluable from 650 healthy postmenopausal women in the low dose group and 310 in the high dose group. Endometrial protection was achieved with dydrogesterone at doses of 5 mg or higher combined with 1 or 2 mg 17beta-oestradiol. The success rate was 97%, 97% and 98% in women receiving 1/5, 1/10 and 1/20 mg, respectively, and 95%, 98% and 91% in women receiving 2/5, 2/10 and 2/15 mg, respectively. A lower success rate was achieved with the 2.5 mg dydrogesterone dosage (93% in the 1/2.5 mg group and 85% in the 2/2.5 mg group) due to more cases of proliferative endometrium. None of the women in the low dose group developed hyperplasia or carcinoma; five (0.7%) had endometrial polyps. In the high dose group, one woman given 2.5 mg dydrogesterone developed hyperplasia; there were no cases of carcinoma. CONCLUSION: 5 mg daily dydrogesterone appears to be the lowest effective dose to ensure endometrial safety in a continuous combined regimen with 1 or 2 mg 17beta-oestradiol.