Effects of Blood Pressure and Intraocular Pressure on Ocular Arterial Blood Flow: Studies on in vitro Models

Placed in 1st Place in the category of Cell Biology and Physiology, Denman ForumGlaucoma is the second leading cause of blindness around the world. Diagnosis of this disease often occurs after the detection of noticeable symptoms, by which point irreversible damage has already been incurred. Glaucoma develops when stress factors induce retinal ganglion cell death, resulting in vision loss. In particular, prolonged reduction in blood flow into the eye may lead to ocular tissue malnutrition and hypoxia, eventually leading to cell death. The posterior ciliary arteries are the main blood supply to the optic nerve head, where glaucoma damages occur first. These arteries traverse the posterior peripapillary sclera to penetrate the eye. This study aims to investigate the effects that different combinations of intraocular pressure, blood pressure, and scleral stiffness have on blood flow of in vitro posterior ciliary artery models. To perform this study, a modeling system of the peripapillary sclera was developed. A number of different polymers (including agarose, polydimethylsiloxane, and industrial TC-5005 gels) were explored to model scleral tissues with various compressive moduli. Multiple models of industrial TC-5005 and agarose were made to mimic sclera of increasing stiffness. The polymers were molded and cured into wall-less vessels and placed into a perfusion chamber where pressure was separately applied to the outside (intraocular) and inside (blood) the vessel at different combinations. Five models of stiffness ranging from 30 – 415 kPa were fabricated for flow tests. The resulting change in fluid flow rate was recorded to determine the combinatory effects of the two pressures through these phantoms. It was found that across all combinations of pressures, the fluid flow would initially increase with stiffness, then upon reaching ~60 kPa achieve a maximum flow. For models much stiffer than 60 kPa, a significant decrease in fluid flow as much as 87% was observed. The initial increase in fluid flow from 30 to 60 kPa may be evidence of the protective effects of scleral stiffening predicted in previous research. This study represents a first step in understanding the potential impacts of the scleral compressive modulus on the fluid flow rate under biological effects by IOP and BP, supporting the hypothesis that sclera stiffness may play an important role in glaucomatous development.Research is partially supported by NIHRO1EY020929A one-year embargo was granted for this item.Academic Major: Biomedical Engineerin

Silver hair market in Japan? Good quality of (whose) life with silver-to-black consumption?

Japanese Society (Silver Market?): Exceptionalism in Socio-Economic Sense? What You See is Not What it is in Japan! This question was my Japanese colleagues and informants confronting me, and I concur with them as I completing this brief…. Perhaps this synopsis could help to realize the limited understanding of we have on another Asia society (despite frequent travels and information exchange in the mobile-Internet age), par­ticularly the enigma about Japanese society’s traditionalism embedded into its supra-modernization trajectories of socio-economic development since 1868! 日本社会（银发市场？）：社会经济的例外主义？ 你所见的并不是真实的日本！这是我提出这问题时，我的日本同事跟消息提供者对我的反驳，而我完成这篇概论后也认同他们的理据……也许这篇概论能帮助我们意识到自己对另一个亚洲社会的认知是如此有限（即使我们经常到日本旅游，而且又身处这信息交流发达的年代），特别是自1868年起，深嵌于社会经济发展超现代化进程中的日本传统主义，对我们来说真的有如谜一样

Biochemical and haematological aspects of ethanol metabolism in humans : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University, New Zealand

Macrocytosis or raised mean cell volume (MCV) (which as measured by the Coulter S counter) is one of the results of alcohol abuse. There is a need to identify (chronic) alcoholics by laboratory tests. The obvious measurement of blood alcohol is not suitable as ethanol is so rapidly cleared from the body. It is usually undetectable 2 – 3 hours after drinking. To this the following battery of tests: MCV, fast haemoglobin, gamma glutamyl transferase and thiamine, have been examined These tests which were performed, on a population consisting of 115 random hospital patients, 14 patients attending diabetic clinic and 13 'normal' volunteers. For ethical reasons it was not possible to obtain samples from known alcoholics. Instead those samples which contained red cells above 92 fl of MCV were suspected of including alcoholics and correlated with other parameter which may be assumed to be elevated in alcoholics. The results showed that there were 23 abnormal findings likely to be associated with heavy drinkings in 70 bloods selected for high MCV

Preparation of bioactive surface via gel oxidation on titanium for biomedical application (hip joint replacement)

Titanium and its alloys are widely used as implant in biomedical applications. They have good mechanical and chemical properties, biocompatibility and biointegration with human body, but they have no ability to bond directly to natural bone. Therefore, alkali and heat treatments (gel oxidation) were introduced to improve the bioactivity of titanium by forming a mixture of sodium titanate and rutile on the surface of titanium. This method enables titanium to possess a bioactive surface which is essential to induce the apatite formation. This study aims to investigate the effects of alkali, sodium removal and heat treatments on in vitro bioactivity of titanium. UV light irradiation was used to study the effect on in vitro bioactivity of titanium. Alkalitreated titanium subjected to heat treatment in air have shown better overall in vitro performance than those treated in argon atmosphere. Therefore, the sodium removal treatment (dilute hydrochloric acid (HCl) treatment) was introduced to convert sodium titanate into anatase to improve the bioactivity of titanium treated in argon atmosphere. Thus, four samples (AT-0.5-HT500R, AT-0.5-HT600R, AT-5-HT500R and AT-5- HT600R) with different ratios of anatase to rutile were produced by varying the concentration of HCl acid treatment and heating temperature in argon atmosphere. It was found that the incorporation of sodium removal treatment has reduced two times the duration of apatite formation as compared with the conventional alkali and heat treatments. In order to further enhance the bioactivity, these samples were subjected to six different conditions of ultraviolet light irradiation and followed by in vitro bioactivity test. As a result, AT-5-HT500R (82.2% anatase and 17.8% rutile) was proven to deliver the best performance. It was confirmed that UV light irradiation enhances the bioactivity by removing hydrocarbon, inducing superhydrophilicity and forming OH groups. It was discovered that the duration of apatite formation was shortened to 7 days. Furthermore, the continuous UVA irradiation during in vitro test resulted in the acceleration of bonelike apatite formation in 3 days. It can be concluded that the sodium removal treatment and UV light irradiation give very significant impact to the formation of bonelike apatite on the titanium surfaces for biomedical applications