Decrease in an Inwardly Rectifying Potassium Conductance in Mouse Mammary Secretory Cells after Forced Weaning.

Mammary glands are physiologically active in female mammals only during nursing. Immediately after weaning, most lactation-related genes are downregulated and milk production ceases. In our previous study, we have detected an inwardly rectifying potassium channel (Kir) 2.1-like current in mammary secretory (MS) cells freshly isolated from lactating mice. This current is highly sensitive to external Ba2+. The potassium permeability of the Kir channels may contribute to the secretion and/or preservation of ions in milk. We hypothesized that the functions of the Kir channels in MS cells are regulated after weaning. To test this hypothesis, we examined the effect of forced weaning on the Ba2+-sensitive Kir current and Kir2.1 expression in the mouse mammary glands. Twenty-four hours after weaning, the lumina of mammary acini were histologically enlarged by milk accumulation. The whole-cell patch-clamp analyses showed that the Ba2+-sensitive Kir current in the post-weaning MS cells was smaller than in the lactating MS cells. The inward conductances of the current in the lactating and post-weaning cells were 4.25 ± 0.77 and 0.93 ± 0.34 nS, respectively. Furthermore, real-time PCR and Western blot analyses showed that Kir2.1 mRNA and protein expression decreased in the post-weaning mammary gland (mRNA, 90% reduction; protein, 47% reduction). Moreover, the local milk accumulation caused by teat sealing decreased Kir conductance in MS cells (2.74 ± 0.45 and 0.36 ± 0.27 nS for control and sealed mammary glands, respectively). This was concomitant with the reduction in the Kir2.1 mRNA expression. Our results suggest that milk stasis after weaning immediately decreases the Kir conductance in MS cells. This decrease in the Kir conductance may be partly caused by the reduction in the Kir2.1 mRNA and protein expression. These alterations during the post-weaning period may be involved in the cessation of ion secretion and/or preservation in the milk

Carotid calcifications in panoramic radiographs are associated with future stroke or ischemic heart diseases : a long-term follow-up study

OBJECTIVE: To assess if carotid calcifications detected in panoramic radiographs are associated with future events of stroke, and/or ischemic heart diseases over 10-13 years in individuals between 60 and 96 years. MATERIALS AND METHODS: Baseline (2001-2004) panoramic radiographs were assessed for evidence of carotid calcifications from individuals with no previous history of stroke and/or ischemic heart diseases. A radiopaque nodular mass adjacent to the cervical vertebrae, at or below the intervertebral space C3-C4, was interpreted as carotid calcification. Annual medical records were searched for ICD 10 codes through 2014. RESULTS: Signs of carotid calcification was demonstrated in 238/635 (37.5%) of the study individuals. Signs of carotid calcification was associated with future stroke and/or ischemic heart diseases (χ2 = 9.1, OR 1.6, 95% CI 1.2, 2.2, p < 0.002). In individuals 60-72 years, a significant association between radiographic signs of carotid calcification and stroke and/or ischemic heart diseases (χ2 = 12.4, OR 2.4, 95% CI 1.5, 4.0, p < 0.000) (adjusted for high blood pressure, diabetes type 2, BMI; OR 1.9, 95% CI 1.1, 3.5, p = 0.03). Individuals (60-72 years) with radiographic evidence of carotid calcifications had a mean cumulative stroke and/or ischemic heart diseases survival time of 12.1 years compared to those without such evidence (13.0 years) (log rank Mantel-Cox χ2 = 10.7, p = 0.001). CONCLUSIONS: Evidence of carotid calcifications in panoramic radiographs is associated with an event of stroke and/or ischemic heart diseases in 60-96-year-old individuals. CLINICAL RELEVANCE: Radiographic evidence of carotid calcifications is associated with stroke and/or ischemic heart diseases. Patients with signs of carotid calcifications should therefore be referred for medical examination

Diagnostic agreement between panoramic radiographs and color doppler images of carotid atheroma

The aim of this study was to investigate the agreement between diagnoses of calcified atheroma seen on panoramic radiographs and color Doppler images. Our interest stems from the fact that panoramic images can show the presence of atheroma regardless of the level of obstruction detected by color Doppler images. Panoramic and color Doppler images of 16 patients obtained from the archives of the Health Department of the city of Valença, RJ, Brazil, were analyzed in this study. Both sides of each patient were observed on the images, with a total of 32 analyzed cervical regions. The level of agreement between diagnoses was analyzed using the Kappa statistics. There was a high level of agreement, with a Kappa value of 0.78. In conclusion, panoramic radiographs can help detecting calcifications in the cervical region of patients susceptible to vascular diseases predisposing to myocardial infarction and cerebrovascular accidents. If properly trained and informed, dentists can refer their patients to a physician for a cardiovascular evaluation in order to receive proper and timely medical treatment