The influence of portal blood upon lipid metabolism in normal and diabetic dogs and baboons

It has been reported that hyperlipidemia can be alleviated in human beings with an end to side portacaval shunt. Understanding the mechanism of the effect has important implications, including the possibility of devising other ways of lowering serum lipid levels. In this investigation, the influence of splanchnic venous blood on lipid metabolism was evaluated in dogs and baboons by altering the portal venous inflow to all, or portions, of the liver and by measuring the effects on different end points, including the serum lipid concentrations and the rate of hepatic lipid synthesis. In other studies, analyses have been made regarding the effect of alloxan induced insulinopenia and of total pancreatectomy on these processes. The results indicate that the effect of complete portal diversion upon serum lipids is mainly due to diversion of the hormone rich venous return from the upper splanchnic organs, although the bypass of the nutritionally rich blood returning from the intestines may play a secondary role. Therefore, a reduction of hepatic lipid synthesis is an important, although not necessarily the sole, factor in the antilipidemic influence of portacaval shunt. The effects upon synthesis and blood lipids are due more to the diversion of endogenous hormones than to the bypass of intestinal nutrients. The substances in portal venous blood that subserve hepatic lipid metabolism are presumably largely the same as the hepatotrophic factors which have been described before as profoundly affecting hepatic structure, function, and the capacity for regeneration. These portal blood factors are multiple and interrelated, but the single most important one seems to be insulin

從人到書，從書到人 : 對文學課本的反思與期望 = From man to book, and book to man : reflections and expectations towards literary textbooks

作者認為文學是教育中不可缺少的成分，它可説是社會、文化與人的「情感教育」。若果一個社會對文學教育不夠重視，它或會因此而有所缺失，甚至乎會喪失「集體回憶」。不同地區的文學教育的表達或體現可以是多形式，包括獨立課程，如香港，或融入語文課程之內，如內地及台灣。教材出版，則是體現課程、展現課程的工具，用以協助教與學，因此兩者的關係極為密切。已故的出版家及社會語言學家陳原曾著有一書：《書和人和我》（1994），以出版人的身份去談書與人的關係，以及彼此間的種種聯想與抒發。從來出版人的終極關心都是文化和人，作者在此書的啟發下，去思考文學教育的發展，並嘗試借用陳原的説法，從人出發。從人去看書，看人需要怎樣的書；再從書去看人，看書怎樣可形塑人

Non-Fermi Liquid behavior at the Orbital Ordering Quantum Critical Point in the Two-Orbital Model

The critical behavior of a two-orbital model with degenerate $d_{xz}$ and $d_{yz}$ orbitals is investigated by multidimensional bosonization. We find that the corresponding bosonic theory has an overdamped collective mode with dynamical exponent $z=3$, which appears to be a general feature of a two-orbital model and becomes the dominant fluctuation in the vicinity of the orbital-ordering quantum critical point. Since the very existence of this $z=3$ overdamped collective mode induces non-Fermi liquid behavior near the quantum critical point, we conclude that a two-orbital model generally has a sizable area in the phase diagram showing non-Fermi liquid behavior. Furthermore, we show that the bosonic theory resembles the continuous model near the d-wave Pomeranchuk instability, suggesting that orbital order in a two-orbital model is identical to nematic order in a continuous model. Our results can be applied to systems with degenerate $d_{xz}$ and $d_{yz}$ orbitals such as iron-based superconductors and bilayer strontium ruthenates Sr$_3$Ru$_2$O$_7$.Comment: 5 pages, 2 figure

Comprehension of noun phrase in Cantonese-speaking preschool children

Also available in print.Thesis (B.Sc)--University of Hong Kong, 2005.A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2005.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

The effect of diabetes mellitus on portal blood hepatotrophic factors in dogs

Ten nondiabetic dogs were submitted to a procedure called splanchnic division which directed the nutrient rich venous return from the intestines into the left lobes of the liver and the hormone rich pancreatico gastroduodeno splenic venous return into the right lobes. Two mth later, the right lobes had undergone the expected gross and microscopic hypertrophy. Compared with the abnormal shrunken and glycogen depleted hepatocytes of the left lobes, the large and otherwise normal hepatocytes of the right lobes had a higher rate of cell division as judged by microscopic examination, measurements of deoxyribonucleic acid synthesis and the results of autoradiography. Both sides had greater cell replication than in the livers of normal unaltered dogs. The dominance of the right lobes following splanchnic division was almost completely eliminated by the prior creation of alloxan induced diabetes in 4 dogs and by the performance of total pancreatectomy at the same time as splanchnic division in 6 dogs. In these 10 diabetic dogs, which were treated with Sc administered insulin for the 2 mth period of the postoperative study, hepatic lobar and cell size were nearly equal on both sides. By light and electron microscopy, the hepatocytes on both sides had abnormalities, somewhat less pronounced on the right. However, the most active cell division was now transferred to the left lobes. The results with alloxan induced diabetes were similar to those after total pancreatectomy, except that lipid deposits were less on both liver sides in the alloxan experiments, and the glycogen was selectively reduced in the right lobes. The latter finding presumably was due to the continued action of glucagon in dogs made diabetic with alloxan. 12 nondiabetic dogs had a procedure called partial portacaval transposition which directed systemic venous blood from the hindquarters, kidneys and adrenal glands into the left lobes of the liver and the total splanchnic venous return into the right lobes. Two mth later, the degree of relative hypertrophy and hyperplasia of the glycogen rich right lobes was even greater than after splanchnic division, as was the morphologic damage to the left lobar hepatocytes. The degree of right lobar hypertrophy following partial portacaval transposition was reduced but not eliminated by pre existing alloxan induced diabetes in 4 dogs and by concomitant total pancreatectomy in 6 more dogs. The dogs were Sc treated with insulin. Structurally, the hepatocytes on the right side after 2 mth were in better condition than were those on the left, although both were abnormal. The dominance of cell division on the right side was reduced, as judged by standard microscopy and by autoradiography, but there was not a shifting of sides. The biochemical analyses reflected the presence or absence of glucagon. These findings are consistent with the earlier multifactorial hypothesis which holds that portal hepatotrophic factors are mainly interreacting hormones generated by splanchnic organs and delivered straight to the liver and that the hormone interrelationships might have augmented significance because of the high concentration of nutritional substrate in the same venous blood. The observations also substantiate by direct testing the suggestion that insulin is the most important hepatotrophic factor and that it profoundly affects many aspects of liver cell structure, division and function