PubMed · 12281821
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
V Thongthai. 1988. [Age misreporting].. https://pubmed.ncbi.nlm.nih.gov/12281821/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The objective of this study was to present a classification of the root development stage of female rat molar teeth and to evaluate the variation in the lactate dehydrogenase (LDH) activity and electrophoretic isoenzyme profile according to the stage of root development of the molar teeth. We also studied the LDH activity and isoenzymes of the pulp of incisor teeth. The stage of development of the rat first molar at the age of 15 days and that of the second molar at the age of 18 days was classified as the beginning of root formation. At the age of 15 days, the electrophoretic profile of the isoenzymes for the first molar showed a prevalence of LDH-1 followed by LDH-2. However, for the maxillary second molar there was a prevalence of LDH-4 followed by LDH-1, while for the mandibular second molar LDH-1 predominated followed by LDH-2 and LDH-4. From 18 days of age, the prevalence was always of LDH-1. The electrophoretic profile of LDH isoenzymes from the pulp of the incisor teeth at the ages studied (25 and 60 days) showed the following order of prevalence: LDH-1 > LDH-2 > LDH-3 > LDH-4 > LDH-5. These results suggest that there are variations in the prevalence of the various forms of LDH isoenzymes in the dental pulp of rats according to the developmental stage of the root.
Astrocytes are known to play an integral role in the development of compartmental boundaries in the brain and in the creation of trauma-induced boundaries. However, the physical relationship between astrocytes and such boundaries in the adult brain is less clear. If astrocytes do respect or play an ongoing role in maintaining such boundaries, a correlation between the position of such a boundary and the morphology of neighboring astrocytes might be observable. In this study, we examined the distribution of astrocytes with respect to the laminar boundaries compartmentalizing afferents to the dentate gyrus molecular layer. In addition, we attempted to determine whether astrocyte morphology is influenced by these laminar boundaries. To this end, protoplasmic astrocytes in the adult rat dentate gyrus were revealed with fluorescent tracer dyes and subsequently analyzed with respect to laminar boundaries demarcated by means of immunolabeling for the lamina-specific molecules EphA4 and neural cell adhesion molecule (N-CAM). We find that astrocyte distribution is influenced by the boundary separating the associational/commissural and perforant path afferents. In addition, we show that astrocytes in this region are polarized in their morphology, unlike typically stellate astrocytes, but that the laminar boundaries themselves do not appear to confer this morphology. This polarized morphology, however acquired, may have import for the functioning of astrocytes within the highly organized composition of the dentate gyrus molecular layer and for the overall microphysiology of this and other brain regions.
PURPOSE: To study the potential risk factors, including radiotherapy (RT) for contralateral breast cancer (CBC), in patients treated for early-stage breast cancer. METHODS AND MATERIALS: The Surveillance, Epidemiology, and End Results database (1973-1996) was used to study the incidence of CBC after breast cancer. The Cox proportional hazards regression model was used to estimate the relative risk (RR) of CBC, with adjustment for confounders, including age, race, histologic subtype, and use of RT. Information on the use of hormonal therapy and chemotherapy was not available in the Surveillance, Epidemiology, and End Results database. RESULTS: A CBC was documented in 5679 (4.2%) of the 134501 localized invasive or intraductal breast cancer patients surviving at least 3 months. The 10- and 20-year actuarial rate of CBC was 6.1% and 12%, respectively. In multivariate analysis, medullary carcinoma (RR = 1.18, 95% confidence interval [CI] 1.02-1.37), black race (RR = 1.20, 95% CI 1.08-1.33), and age >55 years at initial diagnosis (RR = 1.15, 95% CI 1.08-1.22) were associated with increased CBC risk. A total of 1234 (3.3%) of 37,379 patients who received RT developed CBC, and 4445 (4.6%) of 97122 patients who did not receive RT developed CBC. Overall, RT was not associated with an increased risk of CBC (RR = 1.04, 95% CI 0.97-1.10) in multivariate analysis. The CBC risk associated with RT varied substantially with the length of follow-up. During the first 5 years of follow-up, RT was not associated with an increased CBC risk (age-adjusted RR = 0.96, 95% CI 0.88-1.04). For patients surviving for >5 years, RT was associated with a 14% increase in CBC risk (RR = 1.14, 95% CI 1.03-1.26). The increased CBC risk with RT was evident in patients aged <45 years (RR = 1.32, p = 0.01) and >55 years (RR = 1.15, p = 0.04) at initial diagnosis. The 5-, 10-, 15-, and 20-year actuarial rate of CBC was 2.9%, 6.5%, 10.2%, and 13.4%, respectively, for patients with RT; the corresponding rates were 3.0%, 6.0%, 8.9%, and 11.8% for patients without RT. The absolute increase in CBC risk associated with RT was 0.5%, 1.3%, and 1.6% in the 10-, 15-, and 20-year actuarial rate, respectively. CONCLUSION: CBC is not uncommon after breast cancer, especially for certain subsets of patients. RT was associated with a very small increased long-term CBC risk. This minimal increase in CBC risk should not affect clinical decision-making in treatment selection for patients with localized invasive breast cancer or ductal carcinoma in situ. Unnecessary radiation exposure to the contralateral breast should be avoided for all patients with early-stage breast cancer.