We examined the range of the accessory mental foramen [AMF] and its accessory mental nerve in three Japanese cadavers. The diameters of the AMF were relatively small: 0.74 mm, 0.80 mm and 0.89 mm. The distances between the mental foramen and AMF were: 0.67 mm, 2.1 mm and 5.74 mm. The distribution of the accessory mental nerve was different in the three cases. These nerves communicated with the branches of the facial and buccal nerves.
The parotid glands of 228 Japanese human cadavers were examined to determine the incidence and histological features of accessory parotid glands. The incidence was found to be 56% with no differences between right and left sides or between sexes. Thirty parotid glands and their associated accessory glands were examined histologically: eight of these accessory glands were found to be mixed secretory glands (i.e., containing both serous and mucous acini). Thus, the pattern of differentiation of a significant fraction of accessory glands differs from that of the main parotid gland: it appears that mixed acini, present in the early stages of development, persist into later life, and their presence may be related to tumors developing at these sites.
In an attempt to elucidate the effects of denervation on development and maintenance of the structure of the fungiform papilla, unilateral neurectomy of the chorda tympani-lingual nerve of rats was performed at day 1 and at weeks 1, 2, 3, 4, 7, and 10 after birth. Specimens were obtained at days 3, 7 and 10, weeks 2, 3, 4, 6, and 8, and months 3 and 4 after neurectomy for examination by light and scanning electron microscopy. At first, the fungiform papillae were atrophic, then progressed to forms resembling filiform papillae. When an immature fungiform papilla was denervated, it eventually changed to a papilla identical to normal filiform papillae. The elicited changes differed according to the time of neurectomy; it was found that early neurectomy resulted in a more rapid and marked morphological change of the fungiform papillae. The filiform-like papillae derived from the fungiform ones showed various shapes, sizes, and orientations and were rarely present on the unoperated control side of the lingual dorsum. Sections of the filiform-like papillae revealed that they had no taste buds. These findings suggest: (1) Morphogenesis and structural maintenance of the fungiform papillae require the presence of the chorda tympani and/or lingual nerve. (2) Completion of differentiation and maturation differ in time among fungiform papillae. (3) Fungiform papillae may be transformed filiform papillae induced and maintained by a neurotrophic factor or factors coming from the chorda tympani and/or lingual nerve. (4) Fungiform papillae are rarely innervated contralaterally.
Elevation in the temperature induces heat stress to both host cells and the invading pathogen. This study aimed to determine whether continuous mild heat stress (increased temperature without causing significant damage to host cells) can increase susceptibility of biofilm formation of the opportunistic fungal pathogen Candida albicans to low concentrations of three typical antifungal agents. In this way the side effects associated with higher concentrations of the antifungal agents on host cells would be reduced. Fluconazole and micafungin at concentrations ranging from 0.0625 to 2 µg/mL and amphotericin B at concentrations ranging from 0.0625 to 1 µg/mL inhibited less than 20% of cells in biofilm formation. Biofilm formation at 39 or 41°C compared to 37°C resulted in increased susceptibility to the three agents, but especially micafungin. These data suggest that mild heat stress (39°C) would be valuable for increasing the effectiveness of low concentrations of antifungal agents against C. albicans biofilm formation. Thus, the concept of continuous mild heat stress at the site of insertion of medical devices or catheters combined with antifungal agents could be beneficial.Key words mild heat stress; antifungal susceptibility; biofilm formation; Candida albicans Candida albicans is a commensal of human mucosal surfaces and an opportunistic pathogen. C. albicans can form biofilms on medical implants and intravascular catheters resulting in biofilm-related infections and systemic candidiasis.1,2) Fungal biofilms are more resistant to antifungal agents, in particular azoles and polyenes, than planktonic cells. 3)β-1,3-Glucan levels of biofilm-associated C. albicans cell walls increased compared to planktonic cells and those of exogenous biofilm matrix was also elevated.4) Azoles and polyenes bind to the biofilm extracellular matrix including β-1,3-glucans and are prevented from getting to their targets. 4,5) Echinocandins are better than azoles and polyenes for treating biofilms as they inhibit production of β-1,3-glucan. 6)Exogenous mild heat stress has been widely used as a physical therapy for treatment of muscle injury and malignant tumors. 7,8) On the other hand, endogenous mild heat stress (fever at around 39°C) that occurs during bacterial infections induced optimized cytokine expression and pathogen elimination.9) But fever at over 40°C would increase risk of collateral host injury in infected patients.10) Cowen and Lindquist 11) reported that high temperatures such as fever reduced resistance of planktonic cells of C. albicans clinical isolates to high concentrations of fluconazole in a defined medium. However, drug resistance of C. albicans in biofilm conditions is considered to occur through distinctly different mechanisms from the cells in planktonic conditions. 12)In this study, the effect of mild heat stress on the susceptibility of Candida albicans in biofilm formation to low concentrations of fluconazole, micafungin and amphotericin B was tested in vitro. MATERIALS AND METHODSC. albicans Strain C. al...
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