A possible critical dosing period of p-cumylphenol for development of cystic kidneys in rat neonates

In accordance with a previous report on cystic kidneys induced in rat neonates when dosed with p-cumylphenol (PCP) for 18 days from postnatal day (PND) 4, 3 rat neonates were dosed with PCP once a day for 14 days, either from PND 14, 21, 28, 35, or 42 as W2, W3, W4, W5, and W6 groups, respectively, to investigate whether dosing periods in different PNDs influenced the development of cystic renal tubules. The lesion was striking in the W2 group and at a lesser magnitude in the W3 group, whereas either kidney was unaffected when dosing was initiated beyond PND 28. These findings, together with the results from the previous study, suggested that PND 14-28 is a critical dosing period for PCP to develop cystic kidneys in rat neonates. The lining epithelium of the cystic tubules was immunohistochemically positive for AQP2. This finding and the anatomical location indicated that the cystic tubules were of collecting duct origin. Either obstruction, fluid accumulation, or reparative hyperplasia of the lining epithelium was unlikely to be involved in the formation of cystic tubules lined with a monolayer of cuboidal or columnar epithelium with a high nuclear density. Thus, the follow-up investigation on PCP suggested a critical dosing period of PND 14-28 in rat neonates for the development of cystic dilation of renal collecting ducts. This study further supports that additive hyperplasia of the lining epithelium is a fundamental basis of this unique lesion.     

Downregulation of the expression of inhibin α subunit and betaglycan in porcine cystic follicles

Inhibins, as members of the transforming growth factor beta (TGF-β) superfamily, downregulate the synthesis and secretion of follicle-stimulating hormone (FSH) in an endocrine manner. The role of inhibin/betaglycan in the ovary regulation recently gained attention. To date, no data exist on the function of inhibin α subunit and betaglycan in cystic follicles. In this study, the expressions of inhibin α subunit and betaglycan in cystic follicles were investigated using immunohistochemistry, real-time PCR and Western blot analysis. Both inhibin α subunit and betaglycan immunoreactivities were mainly localized in the granulosa cells of follicles. Expression of inhibin α subunit and betaglycan was inferior in cystic follicles compared with that in normal large follicles. However, the result of enzyme-linked immunosorbent assay showed no significant difference in the decreasing in concentration of inhibin α subunit in cystic follicular fluid compared with the control (P>0.05). In this study, we explored the effects of FSH on betaglycan expression in granulosa cells in vitro. As expected, a significant increase in the expressions of betaglycan mRNA and protein in granulosa cells was observed in response to exogenous FSH (30 ng/ml) (P<0.05) compared with the control. Consequently, this study provides evidence that the expressions of inhibin α subunit and betaglycan are inferior in cystic follicles, and this may be caused by the decrease in FSH in the presence of a cystic follicle.     

Oxygen delivery to the fish eye: blood flow in the pseudobranchial artery of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)

Similar to gas secretion into the swimbladder, some teleosts also exhibit ocular gas secretion to supply their thick and avascular retina with oxygen. The process in the eye, however, is complicated by the fact that the retina is supplied with arterial blood only indirectly through the pseudobranch, a reduced gill arch of still unknown function. Approaches for closer analysis of the physiological implications of this serial blood supply arrangement and the associated process of O₂ release include complete unilateral vascular isolation of eye and/or pseudobranch while maintaining normal blood flow characteristics for undisturbed operation of the counter-current rete mirabile.Blood flow velocity in the afferent pseudobranchial artery (aPA; essentially equal to ophthalmic artery flow) of rainbow trout was measured by application of ultrasonic Doppler techniques. Accurate determination of flow rate in the untouched vessel was facilitated by mounting the Doppler crystal with a custom-made holder on the bone of the jaw and raw signal analysis by Fast Fourier Transformation for improved signal/noise ratio. Normal unilateral aPA blood flow was 746 l min^–1 kg^–1 body weight, (1.6% of cardiac output), the tissue-weight-specific blood flow was 3.6 ml min^–1 g^–1 for pseudobranch and 2.3 ml min^–1 g^–1 for the retina. Only about 28% of the oxygen potentially available with maximal activation of the Root effect is actually consumed in pseudobranch and retina. This generous supply of blood and the implicit safety margin may serve minimization of pH disturbances of retinal tissues, but may also come suitable during unilateral occlusion of supplying arteries for continued oxygen supply to the retinae. During contralateral occlusion, flow through the ipsilateral aPA increased to 136%. According to the normally low O₂ extraction, a minimal flow of 36% through bilateral anastomosis and contralateral ophthalmic artery may maintain complete contralateral oxygen supply.     

TENESMUS AND STRANGURIA FROM A CYSTIC UTERINE REMNANT

A 14-year-old domestic short hair spayed female cat was examined for tenesmus and stranguria. The abdominal mass discovered was removed and found to be a cystic uterine remnant. Tenesmus and stranguria resolved following mass removal.     

奶牛卵巢囊肿的研究进展

本文从卵巢囊肿的影响因素、发病机理、研究方法展开论述,使读者对该病的认识进一步加深,并且为今后深入研究此病提供更多的理论基础：     

Congenital orbital cysts of neural tissue in two dogs

A 3-month-old English Cocker Spaniel and a 6-month-old miniature poodle presented with clinical signs related to an abnormal right eye since birth. In both dogs, the right globe could not be identified and was replaced by a fluctuant intraorbital mass covered by a vascularized mucous membrane. Ultrasonography demonstrated that both masses were cystic structures markedly larger in size than the normal contralateral globes. In both cases, surgical excision revealed a multilobular cyst filling the whole orbital cavity. Histopathologic examination and immunostaining for glial fibrillary acid protein and S100 protein supported a diagnosis of neural cysts associated with ocular dysplasia. The definitive diagnosis was congenital cystic eye and microphthalmos with cyst for the Cocker Spaniel and miniature poodle, respectively. Karyotype was normal in both dogs. Congenital cystic eye and microphthalmos with cyst result from defects in early embryonic life that arise following formation of the optic vesicle and prior to closure of the optic fissure. To the authors' knowledge neither has been reported in the canine species. They should be considered in the differential diagnosis of orbital cysts in dogs.