Reduction of Kiss1 expression in the anteroventral periventricular nucleus is associated with atrazine-induced attenuation of the luteinizing hormone surge in female rats.

Atrazine, a commonly used herbicide, suppresses the luteinizing hormone (LH) surge in female rats, although the underlying mechanism remains unclear. Kisspeptin, encoded by the Kiss1 gene, is a hypothalamic peptide that controls gonadotropin-releasing hormone (GnRH) release from the GnRH neurons. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) are involved in regulating pre-ovulatory GnRH and LH surge.

Reduced responsiveness of kisspeptin neurons to estrogenic positive feedback associated with age-related disappearance of LH surge in middle-age female rats.

Age-related disappearance of the LH surge is one of major biomarkers of reproductive aging in female rats. Kisspeptin neurons in the hypothalamic anteroventral periventricular nucleus (AVPV) are proposed as the critical regulator of the preovulatory LH surge in response to estrogenic positive feedback. Here we investigated the possible involvement of the AVPV kisspeptin neurons in the disappearance of the LH surge in middle-age rats.

Traumatic injury to permanent tooth resulting in complete root resorption: a case report.

When a tooth is avulsed and replanted following traumatic dental injury, complications such as replacement and inflammatory resorption may occur. Ultimately, resorption may result in loss of the tooth. This case report describes a traumatic injury to a permanent tooth resulting in complete root resorption within a short period, which required surgery.

[An evaluation of virtual waxing up system with haptic interface].

Purpose: The purpose of this experiment was to construct a system of waxing pattern using virtual reality in the odontological field. The success of operation with feedback on the maniphalanx sense of waxing is reported.

Methods: The constructed device was a system based on PHANToM DESKTOP (SensAble Technologies Inc.

Improved technique for fetal heart examination in developmental toxicity studies in rats.

Bouin's or a 10% formalin solution has been used to fixate internal fetal observations for developmental toxicity studies in rats. However, these fixatives are known to cause contraction of the ventricle of the heart and arteries, which makes dissection and observation more difficult. Fetuses on day 20 of gestation from pregnant Crj:CD(SD)IGS rats were injected with 10 w/v% magnesium chloride/10 vol% neutral buffered formalin solution into the thoracic cavity, and then fixed in 10 vol% neutral buffered formalin.