Comparative anatomy of the ophthalmic rete and its relationship to ocular blood flow in three species of marine mammal.

OBJECTIVE: To examine the blood supply to the eyes of bottlenose dolphin (Tursiops truncatus), spotted seal (Phoca largha), and California sea lion (Zalophus californianus). Emphasis is placed on exploring the anatomic function in the context of aquatic life. PROCEDURE: Methyl methacrylate casts were prepared and studied using a scanning electron microscope. Infrared images of the eye were recorded using a thermocamera. RESULTS: In all three marine species, blood is supplied to the ophthalmic rete. The main source of blood supply to the rete is the basilar rete via the spinal rete in the dolphin and via the ophthalmic artery in the seal and sea lion. The retinal and choroidal arteries are derived from the rete. The dolphin rete showed a very well-developed arterial network occupying most of the orbit. The rete in pinnipeds was less developed with several entwining arteries, unlike that in cetaceans. Thermographic examination revealed that the eye shows a higher degree of thermal emission than adjacent areas of the skin in these 3 species. DISCUSSION: The role of the rete in aquatic mammals appears to conserve ocular temperature so that the appropriate operating temperature for photoreceptors and ocular muscles can be maintained in a cold ambient temperature. Additionally, the rete might have a flow-damping effect by maintaining resistance to blood flow in the orbit. This study highlights the special nature of ocular vascular anatomy and function that enabled the unique adaptation of aquatic mammals to life in aquatic habitats.

Prevention of limb amputation in patients with limbs ulcers by autologous peripheral blood mononuclear cell implantation.

There are many cases of amputation of ischemic limbs of dialysis patients due to diabetes, despite the availability of medicine therapy and vascular by-pass operations. As there is extensive ruin of the vascular bed due to diabetes, vascular regeneration therapy by stem cell implantation is effective. Thirty patients with ischemic limbs due to diabetes (not including type-I) and on dialysis for chronic renal failure (19 cases), diabetes (5 cases), dialysis patients without diabetes (4 cases), and arteriosclerosis obliterans (ASO, 2 cases) were treated by autologous peripheral blood stem cell (PBSC) implantation where imminent amputation was under consideration. Granulocyte Colony Stimulate Factor (G-CSF: 5 microg/kg/day) was administered subcutaneously for 4 days before PBSC collection, that was carried out using a centrifuge (Spectra and/or CS3000) via the vein. The collected PBSC, containing 4.2 x 10(7) of CD 34 positive cells, was divided into units of 0.5-1.0 mL and implanted, without any purification, to the ischemic area of the limbs in about 65 points. In 21 cases, normalization of limb temperature was observed by thermograph, and symptoms also improved. The result of this first attempt of PBSC implantation is that we were able to save 22 ischemic limbs. This is the first large report of the application of regenerative medicine to peripheral ischemic limbs.

Senile plaques and cerebral amyloid angiopathy in an aged California sea lion (Zalophus californianus).

Senile plaques (SPs) and cerebral amyloid angiopathy (CAA) consisting of ß-amyloid (Aß) are major features in the brain of Alzheimer's disease (AD) patients and elderly humans and animals. In this study, we report the finding of SPs and CAA in an aged sea lion (30 years), which is the first demonstration of AD-related pathological changes in a marine animal. Histologically, SPs were observed at the cerebral cortex, most frequently at the frontal lobe, with two morphologically different types: the small round type and the large granular type. Only the small round SPs were positive for Congo red staining. The SPs were equally immunoreactive to Aß40 and Aß42 and were mainly composed of Aß with an N-terminal pyroglutamate residue at position 3. Amyloid depositions at vessel walls were noted at the meninges and within the parenchyma. Interestingly, double immunofluorescence staining for Aß40 and Aß42 showed that the two subtypes were deposited segmentally in different parts of the vessel walls. The lesions observed in the sea lion suggest that Aß deposition is widely present in various animal species, including marine mammals; however, the peculiar deposits similar to cotton wool plaques and the specific pattern of CAA are characteristic features of this animal.

Different growth capacity between infant and adult mouse hepatocytes in vitro correlates to the cyclin D1 level without relation to oxidative DNA damage.

BACKGROUND: Proliferating capacity of hepatocytes is rapidly decreased during growth into maturity, but its exact reason(s) are not well known. METHODS: Hepatocytes isolated from infant (10-14 days old) and adult (10-13 months old) B6C3F1 mice were cultivated in the medium containing epidermal growth factor and insulin. Proliferative capacity, apoptosis, morphological changes, cell cycle proteins and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were compared between the two hepatocyte populations. RESULTS: Although adult hepatocytes rapidly underwent cellular crisis characterized by extended morphology and multiple nuclei without proliferation, infant hepatocytes could proliferate with less crisis. Cyclin D1 was much more abundant in the infant than adult cells, but there was no difference according to the expression of cdk4, cdk2, cyclin E and cdk inhibitors (p16(Ink4) (p16), p21(Cip1/Waf1) (p21) and p27(Kip1) (p27)). 8-OHdG became high soon after cultivation, while it rapidly went down after day 2 both in the infant and adult cells. CONCLUSIONS: The high growth capacity of infant hepatocytes in vitro was dependent on the cyclin D1 level, but there was no relation to 8-OHdG.