CEREBROSIDE MAY BE FALSELY IDENTIFIED AS A SOLUBLE ''BRAIN SPECIFIC PROTEIN''

—Injection of a soluble protein fraction from mouse brain into rabbits gave rise to an antibody which was specific for galactocerebroside. The antigen had the following characteristics: (1) it was present in the soluble fraction of a mouse brain homogenate but absent from the soluble fraction of homogenates of mouse liver, spleen, kidney and testis; (2) it was non-dialysable; (3) it voided from a Sephadex G200 column; (4) on immunodiffusion with antibody directed against it, it gave a sharp single precipitin band; (5) it bound to DEAE cellulose column and was eluted with high salt. Given these characteristics the antigen might have been identified as a ‘brain specific protein’. However, the lipid nature of the antigen was revealed when it was found that it was not destroyed by Pronase digestion and could be quantitatively extracted with chloroform-methanol. The antigen has been identified as a galaetocerebroside and is 100 times more abundant in the myelin fraction than in the soluble fraction of the mouse brain homogenates. The antigen could have been falsely identified as a ‘brain specific protein’ if the antigenicity and macromolecular behaviour of lipids was overlooked.     

Enterobacter agglomerans: the clinically important plant pathogen.

During a 5-month period Enterobacter agglomerans, now described as a member of the phytopathogenic genus Erwinia, was isolated from 13 patients in a general hospital; in 1 patient it was isolated from two sites. In six instances the organism was the sole pathogen isolated, in two instances it may have contributed to infection and in the remaining instances it was probably a transient saprophyte. The strains showed some variation in biochemical reactions but were similar in colonial morphology and were consistently sensitive to several antibiotics. Although this organism is prevalent in the general environment and usually relatively benign, it does have a potential for nosocomial infection.     

Studies on the Metabolism of Fluoroacetate in the Liver of a Rat

In a rat poisoned with sodium fluoroacetate no accumulation of citrate was found in the liver, while in that of a frog fluoroacetate adtninistration was found to cause a marked increase of citrate. In this paper, it was shown that even in a rat when it was treated with insulin before fluoroacetate administration, citrate accuillulation could be found in the liver. In the experiments in vitro using slices of a rat liver it was also shown that fluoroacetate could cause an accumulation of citrate and inhibited the oxidation of malate in the slices of a normal as well as an insulinized liver.     

Ring chromosome 15 in child with a minor dysmorphism of phenotype

Summary The analysis of a karyotype of a girl with slight mental retardation, without significant dysmorphism, showed the presence of a ring chromosome in group 13–15. By the application of G technique it was discovered that in this case it was an aberrant chromosome 15.Besides retardation in growth and a slight mental backwardness in this case, it was confirmed that in cases of ring 15 syndrome no preponderant change appears in phenotype.     

A spontaneous outbreak of polycholorinated biphenyl (PCB) toxicity in rhesus monkeys (Macaca mulatta): toxicopathology.

Polychlorinated biphenyls (PCBs) were shown to be the cause of a wasting syndrome and reproductive dysfunction in a group of rhesus monkeys (Macaca mulatta). The polychlorinated biphenyls were found by gas chromatographic analysis in high amounts in the superficial layers of concrete slab floors in the housing facility. The concrete sealant was suspected as the original source although it is not known whether it contained polychlorinated biphenyls before it was applied or if it was contaminated later. Histopathologic findings for the most part were confined to epithelial tissues where squamous metaplasia of several glandular tissues was observed. A striking finding was severe hypertrophy of the glandular stomach and a similar but less severe lesion in the colon. The lesions may be related in part to impaired vitamin A metabolism, but not to a dietary deficiency.     

An unstable giant satellite associated with chromosomes 21 and 22 in the same individual.

The short arms of the acrocentric chromosomes are among the most common sites in which to find human chromosomal heteromorphisms. Heteromorphic chromosomes are noted for their variability between individuals and populations; however, they generally are consistent within an individual. Contrary to this general rule, a normal female was found to have a giant satellite on the short arm of a chromosome 22 in most lymphocytes and fibroblasts, but in other cells, it was attached to a chromosome 21. Furthermore, in some cells, it was found on multiple chromosomes, that is, on both 22's or on a 21 and a 22. The familial nature of this heteromorphism was established when it was found in the woman's mother, where it was confined exclusively to chromosome 22. These results suggest an unstable giant satellite associated with both G-group chromosomes of a normal individual. Results are discussed in the light of the patient's occupational exposure to insecticides at a mushroom farm.     

广东发现细裂玉凤花

2007年9月,对广东省惠州市新墟镇白云嶂进行植物学考察时,在一个斜坡上的一片次生阔叶林的潮湿林缘,发现了兰科植物细裂玉凤花Habenaria leptoloba Benth。此植物的模式产地为香港,第一次采集时间为1857年,后来虽在香港仍有发现,但事隔150年后才在广东发现。     

The murine Pes1 gene encodes a nuclear protein containing a BRCT domain

Pescadillo was originally identified in the zebrafish Danio rerio as a site of a retrovirus-insertion mutation that caused severe defects during embryogenesis. In particular, growth of the fetal zebrafish liver was significantly affected by loss of pescadillo function. To begin to understand the role of pescadillo during mammalian hepatogenesis we identified the murine homologue of pescadillo and named it Pes1. A single gene localized to chromosome 11 on the mouse genome encodes Pes1. Although Pes1 mRNA was detected in all tissues examined it was present at the highest levels in both adult and fetal liver. Analysis of the predicted amino acid sequence of Pes1 found it to contain a BRCT domain, which has previously been found in several proteins involved in cell-cycle checkpoints and DNA repair. Consistent with a putative role in these processes we found that when recombinant Pes1 protein was expressed in HepG2 cells it localized to the nucleus.     

Characterization of lipophorin binding to the fat body of Rhodnius prolixus

In insects, lipids are transported by a hemolymphatic lipoprotein, lipophorin. The binding of lipophorin to the fat body of the hematophagous insect Rhodnius prolixus was characterized in a fat body membrane preparation, obtained from adult females. For the binding assay, purified lipophorin was radiolabelled in the protein moiety (125I-HDLp), and it was shown that iodination did not affect the affinity of the membrane preparation for lipophorin. Under incubation conditions used, lipophorin binding to membranes achieved equilibrium after 40-60 min, but this time was longer when a low concentration of lipophorin was present in the medium. The capacity of the fat body membrane preparation to bind lipophorin was abolished when membranes were pre-treated with trypsin, and it was also affected by heat. When 125I-HDLp was incubated with increasing concentrations of membrane protein, corresponding increases in binding were observed. Lipophorin binding was sensitive to pH, and it was maximal between pH 6.0 and 7.0. The specific binding of lipophorin to the fat body membrane preparation was a saturable process, with a Kd of 2.1 +/- 0.4 x 10(-7)M and a maximal binding capacity of 289 +/- 88 ng lipophorin/microgram of membrane protein. Binding to the fat body membranes did not depend on calcium, but it was affected by ionic strength, being totally inhibited at high salt concentrations. Suramin also interfered with lipophorin binding and it was abolished in the presence of 2 mM suramin, but at concentrations of 0.05 and 0.1 mM it seemed to increase binding activity slightly. Fat body membrane preparation from Rhodnius prolixus was able to bind lipophorin from Manduca sexta larvae.     

广东发现细裂玉凤花

2007年9月,对广东省惠州市新墟镇白云嶂进行植物学考察时,在一个斜坡上的一片次生阔叶林的潮湿林缘,发现了兰科植物细裂玉凤花Habenaria leptoloba Benth.。此植物的模式产地为香港,第一次采集时间为1857年,后来虽在香港仍有发现,但事隔150年后才在广东发现。     

The Role of Temporal Information in Perisaccadic Mislocalization

In dynamic environments, it is crucial to accurately consider the timing of information. For instance, during saccades the eyes rotate so fast that even small temporal errors in relating retinal stimulation by flashed stimuli to extra-retinal information about the eyes’ orientations will give rise to substantial errors in where the stimuli are judged to be. If spatial localization involves judging the eyes’ orientations at the estimated time of the flash, we should be able to manipulate the pattern of mislocalization by altering the estimated time of the flash. We reasoned that if we presented a relevant flash within a short rapid sequence of irrelevant flashes, participants’ estimates of when the relevant flash was presented might be shifted towards the centre of the sequence. In a first experiment, we presented five bars at different positions around the time of a saccade. Four of the bars were black. Either the second or the fourth bar in the sequence was red. The task was to localize the red bar. We found that when the red bar was presented second in the sequence, it was judged to be further in the direction of the saccade than when it was presented fourth in the sequence. Could this be because the red bar was processed faster when more black bars preceded it? In a second experiment, a red bar was either presented alone or followed by two black bars. When two black bars followed it, it was judged to be further in the direction of the saccade. We conclude that the spatial localization of flashed stimuli involves judging the eye orientation at the estimated time of the flash.     

Spermiogenesis in the rainbow trout (Salmo gairdneri)

In an ultrastructural study on the spermiogenesis of the rainbow trout (Salmo gairdneri R.) four spermatogenetic stages were identified. In young round spermatids, the nuclear chromatin was first heterogeneous (euchromatin and heterochromatin). Subsequently, it became more homogeneous and started to condense in the form of coarse granules and fibers and then into fibrils associated in ribbon-like elements which eventually partly fused together. During early spermiogenesis, a juxtanuclear vacuole appeared in the area where the nuclear envelope was specialized due to condensation of material between the two envelopes and a slight accumulation of nuclear material. This area was finally located in the anterior part of spermatids and spermatozoa; it probably plays a role during fertilization. A flagellar rootlet appeared early in spermiogenesis; it may play a role in the attachment of the flagellum to the nucleus since it persisted until the centriolar complex was definitively fixed in the implantation fossa. The flagellum did not display a plasma membrane and was first located in the cytoplasm, but when it was later extruded from the cell, it acquired a membrane. The cytoplasm was rich in ribosomes (free or in small groups) but poor in membranous organelles. The few mitochondria polarized around the centriolar complex were finally organized into an annular mid-piece. The spermatids remained connected by intercellular bridges until the end of spermiogenesis. The complexity of trout spermiogenesis is intermediate between that in poecilids and that in carp and pike, which have very simple spermatozoa. The role of the material from the nucleus and the cytoplasm reaching the Sertoli cell in the control of spermatogenesis has been discussed.     

联合荧光光谱与寿命法检测多次高温加热油

三维荧光光谱法检测多次高温加热植物油,该方法能快速、准确的获得待测样品的三维荧光光谱特征图,但只是定性的分析。当荧光强度变化较小的时候,容易出现误检、漏检的情况。先用三维荧光光谱技术分析植物油样品的光谱信息,然后再通过荧光寿命法,计算多次高温加热植物油中荧光光子的寿命,通过与未加热油荧光寿命的对比,检测多次高温加热植物油。二者联合,进一步提高了检测的准确度,有利于解决误检、漏检的问题,从而为高温加热油的检测提供有力的参考。     

Origin of the v. portae and variability of its tributaries in laboratory animals. II. The guinea pig (Cavia aperea f. porcellus)

The authors investigated the origin of the v. portae and variability of its main tributaries in 30 adult guinea pigs (Cavia aperea f. porcellus). The venous bed was visualized by means of blue-dyed latex. The v. portae was formed the most frequently - in 17 cases (56.7%) - by the confluence of three veins - the v. mesenterica cranialis, the v. lienalis and the v. gastroepiploica dextra; less often it was formed from four or five tributaries and in one case only it was formed by union of the v. mesenterica cranialis and the v. lienalis. The v. gastrica sinistra was a tributary of the v. lienalis in 24 cases (80.0%). It arose on the ventral and the dorsal surface of the stomach, in the region adjacent to the curvatura minor ventriculi. In 21 cases (70.0%) it was joined by an independent v. cardiaca. The v. lienalis originated in the hilus lienis, usually as a result of the union of two venous trunks. Inter-organ anastomoses were found in 26 cases (86.7%); in 10 cases (33.3%) they occurred simultaneously between the spleen and the stomach and between the spleen and the pancreas, while in 16 cases (53.3%) they connected the superior pole of the spleen with the stomach. An independent v. gastroepiploica dextra was present in 19 cases (63.3%) as a tributary of the v. portae. In 22 cases it was joined by the v. pylorica. A v. pancreaticoduodenalis cranialis was present in 27 cases (90.0%). In 18 cases (60.0%) it united with the v. gastroepiploica dextra to form a common trunk, the v. gastroduodenalis, which joined the v. portae; in two cases (6.7%) it was an independent tributary of the v. portae. In six cases it was connected with the v. lienalis and in three cases (10.0%) it was replaced by a few vv. pancreaticae emptying into the v. lienalis. A typical v. pancreaticoduodenalis caudalis, as a tributary of the a. mesenterica cranialis, was found in 19 cases (63.3%). In two cases, together with the v. pancreaticoduodenalis cranialis, it formed a single trunk (the v. pancreaticoduodenalis communis). A comparison of the v. portae and its tributaries in the guinea pig and the cat has so far not brought to light any significant morphological differences relative to their different zoological classification and their different modes of life.     

The genetic legacy of the Mongols

We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: approximately 8% of the men in this region carry it, and it thus makes up approximately 0.5% of the world total. The pattern of variation within the lineage suggested that it originated in Mongolia approximately 1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior.     

The 3' terminal sequence of chicken ovalbumin messenger RNA and its comparison with other messenger RNA molecules.

The subcellular distribution of actin in embryonic chick fibroblasts and brain was examined biochemically. Several gentle extraction procedures, which did not cause the breakdown of muscle filamentous actin, caused the release of large amounts of “cytoplasmic actin” in a monomeric form. This did not behave as a precursor or degradation product of filamentous actin in pulse label experiments and failed to form filaments under the same conditions as muscle actin. However, when it was purified and concentrated it was able to form aggregates which were very similar to paracrystals of muscle filamentous actin. These results suggest that cytoplasmic actin is at a higher concentration than muscle actin before it will polymerize, and that in the cell much of it is either monomeric or in a labile state.     

The failure of morphology to contribute to the modern synthesis

How much, if anything, morphology contributed to the modern synthesis is partly a matter of how one defines that term. In the strict sense, morphology is a purely formal discipline and had very little to contribute. Morphology may also be considered a kind of data, and when it becomes functional a better case can be made for its role in evolutionary studies. Be that as it may, the incorporation of morphology into the synthesis was a later development. The initial focus was at the populational level, including the problems of speciation, which makes sense because that was where the opportunities seemed to be. As the synthesis evolved and matured it expanded its horizons and incorporated a larger range of topics. Very little discussion of morphology occurs in the canonical writings of the so-called architects. At the time when the synthesis was supposedly complete, which was around 1950, the incorporation of morphology into it was just beginning.     

Syphilis in renaissance Europe: rapid evolution of an introduced sexually transmitted disease?

When syphilis first appeared in Europe in 1495, it was an acute and extremely unpleasant disease. After only a few years it was less severe than it once was, and it changed over the next 50 years into a milder, chronic disease. The severe early symptoms may have been the result of the disease being introduced into a new host population without any resistance mechanisms, but the change in virulence is most likely to have happened because of selection favouring milder strains of the pathogen. The symptoms of the virulent early disease were both debilitating and obvious to potential sexual partners of the infected, and strains that caused less obvious or painful symptoms would have enjoyed a higher transmission rate.     

宁夏盐池长芒草草原和苜蓿人工草地水分利用研究

 本文用离体快速称重法对宁夏盐池长芒草天然草地和苜蓿人工草地的水分利用状况进行了比较研究。研究发现：很干旱的苜蓿草地具有较高的生物量,而在水分条件相对较好的长芒草草地中生产力却很低。苜蓿草地的蒸腾耗水量占蒸散量的86.9%,而长芒草草地中只占40.7%。水分利用强度苜蓿草地为137.32%,而长芒草草地为88.72%,而且有迹象表明,苜蓿草地的水分利用深度超过了180cm,而长芒草草地则保持在180cm范围之内。两草地的蒸腾效率在整个生长季中基本一致,而蒸散效率苜蓿草地为0.82‰,长芒草草地为0.54‰。经过一个生长季,苜蓿草地水分亏缺达-101.8mm,而长芒草草地为-17.6mm。