Clinical value of urinary and serum pseudouridine in diagnosis and monitoring of primary liver cancer

Urinary and serum pseudouridine concentrations were determined by high-performance liquid chromatography in 80 patients with primary liver cancer, 32 with benign space occupying lesions of the liver, 42 with liver cirrhosis and 40 healthy subjects. Their mean urinary and serum pseudouridine levels were 39.2 +/- 11.5 nmol/mumol creatinine and 3.4 +/- 1.3 mumol/L, 24.5 +/- 5.4 nmol/mumol creatinine and 2.5 +/- 0.5 mumol/L, 22.8 +/- 7.8 nmol/mumol creatinine and 2.3 +/- 0.4 mumol/L, 26.4 +/- 4.6 nmol/mumol creatinine and 2.3 +/- 0.4 mumol/L, respectively. Exceeding the mean plus 2SD of pseudouridine of healthy control was considered as positive value for the diagnosis of primary liver cancer. Thus the positivity of urinary and serum pseudouridine in hepatoma was 71.3% and 70.0%, respectively. The positive rate of combined pseudouridine and alpha-fetoprotein assay was 91.3% in patients with hepatoma. Besides, pseudouridine levels could elevate before positive localization and reduce to normal levels after tumor resection. The results showed that the determination of pseudouridine is of clinical significance in the diagnosis and monitoring of primary liver cancer.

[Nationwide survey of the distribution of human parasites in China--infection with parasite species in human population]

The infection rate of main species of parasites and their character by first nationwide survey of human parasites was made. The overall infection rate of human intestinal parasite and the infection rate of most species of parasites were higher in females than that in males. The infection rate according to the age group, the highest infection rate was found in the group aged 5-14 years. With regard to the relation between parasitic infections and occupations of the infected persons, the highest infection rates of Ascaris lumbricoides were exhibited in school children, of hookworm and Clonorchis sinensis were in halfpeasants and halfmerchant and vegetable grower; of Trichuris trichiura were in fishers, of Giardia lamblia, Entamoeba histolytica and Taenia were in herdsmen and halfherdsmen and halfpeasants. In this survey it is also shown that each nationality has their main species of parasites. The family clustering of some main parasites were proved by some province/autonomous region/municipality.

[Characteristics and recent trends in endemicity of human parasitic diseases in China]

An analysis of the nationwide survey of the distribution of human parasites in the light of the literature previously published, two major trends in the endemicity of parasitic diseases in China was observed. For one trend, the infection rate of E. histolytica, Fasciolopsis buski and soil-transmitted helminthasis etc. declined markedly. The second trend was that the prevalence of food-transmitted parasitic diseases (Trichinella spiralis, Clonorchis sinensis, Paragonimiasis, cysticercosis) and hydatidosis was increasing. The relationship between the social economic factors and the two trends were discussed.

Tissue IGFBP-3 proteolysis: contrasting pathophysiology to that in the circulation

Endogenous IGFBP-3 has been examined in the circulation and in four different extravascular fluids in normal healthy adults and in patients with psoriasis or arthritis. In all of these cases there was no apparent increase of IGFBP-3 protease activity in the circulation. In contrast, endogenous IGFBP-3 from normal skin interstititial fluid and synovial fluid from healthy adults was found to be predominantly in the 29 kDa proteolytically modified form. This indicated that in these extravascular fluids in normal healthy adults a protease was active which was similar, if not identical, to that found in the circulation in pregnancy and other conditions. This was confirmed by the fragmentation of recombinant IGFBP-3 when incubated with these fluids. When the skin interstitial fluid or synovial fluid were taken from abnormal tissues (psoriasis in the former and osteoarthritis or rheumatoid arthritis in the latter) there was a considerable reduction in the amount of endogenous IGFBP-3 in the 'clipped' form and a reduction in the protease activity. In psoriatic lesions, this reduction in IGFBP-3 protease activity was shown to be due to the presence of an inhibitor in the interstitial fluid but not in the circulation. In both peritoneal and follicular fluid, the ratio of intact to fragmented IGFBP-3 appeared to relate to the oestrogen status. In peritoneal fluid there was a decrease in intact IGFBP-3 during the late proliferative/early secretory phase of the endometrial cycle. In the ovary there was an increase in the amount of fragmented IGFBP-3 in the follicular fluid from the dominant follicle in comparison with atretic follicles from the same ovary. There is normally little proteo-lysis of IGFBP-3 in the circulation but this increases in many conditions where there is increased metabolic activity. The same enzyme(s) appear to be active in many extravascular fluids but under very different regulation. The activity in these extravascular fluids is normally high but can be decreased with local tissue inflammation; this decrease appears to be mediated by the induction of a local inhibitor.

Increased vulnerability of hypertrophied myocardium to ischemia and reperfusion injury. Relation to cardiac renin-angiotensin system

Hearts of pressure-overload hypertrophy show an increased activation of intracardiac renin-angiotensin system which may contribute to ischemia and reperfusion injury. The purpose of this study is to evaluate whether the hypertrophied myocardium is more vulnerable to ischemia and reperfusion injury and to find out its relation to the cardiac renin-angiotensin system. Hypertrophied rat hearts induced by abdominal aortic banding for 6 weeks were subjected to 2 hours of hypothermic ischemic arrest followed by 30 minutes of reperfusion, and their cardiac function recovery was compared with that of sham-operated normal control hearts. The cardiac renin activity and angiotensin II content before ischemia and after reperfusion were determined. It was found that both the pre-ischemic renin activity and angiotensin II level were higher in hypertrophied myocardium than those in the control: ischemia and reperfusion injury increased both renin activity and angiotensin II content in the two groups, but the renin activity and angiotensin II level were further elevated after reperfusion in the hypertrophied hearts than those in the control hearts. Meanwhile, the cardiac function recovery after 30 minutes reperfusion in the hypertrophied hearts was poorer than that in the control. Correlation analysis revealed that there was a negative correlation between the cardiac output recovery and the myocardial angiotensin II content (r = -0.8411, P < 0.001). It is concluded that ischemia and reperfusion injury can activate cardiac renin-angiotensin system in isolated rat heart, which may be responsible for the increased susceptibility of the hypertrophied myocardium to ischemia and reperfusion injury.

Glycoluril

The crystal structure of glycoluril [tetrahydroimidazo-[4,5-d]imidazole-2,5(1H,3H)-dione, C4H6N4O2] has been determined. The molecule has two equivalent planes containing urea moieties, and hence exhibits C2v symmetry. The dihedral angle is found to be 124.1 (4) degrees.

Phylogenetic inference under the pure drift model

When pairwise genetic distances are used for phylogenetic reconstruction, it is usually assumed that the genetic distance between two taxa contains information about the time after the two taxa diverged. As a result, upon an appropriate transformation if necessary, the distance usually can be fitted to a linear model such that it is expressed as the sum of lengths of all branches that connect the two taxa in a given phylogeny. This kind of distance is referred to as "additive distance." For a phylogenetic tree exclusively driven by random genetic drift, genetic distances related to coancestry coefficients (theta XY) between any two taxa are more suitable. However, these distances are fundamentally different from the additive distance in that coancestry does not contain any information about the time after two taxa split from a common ancestral population; instead, it reflects the time before the two taxa diverged. In other words, the magnitude of theta XY provides information about how long the two taxa share the same evolutionary pathways. The fundamental difference between the two kinds of distances has led to a different algorithm of evaluating phylogenetic trees when theta XY and related distance measures are used. Here we present the new algorithm using the ordinary-least-squares approach but fitting to a different linear model. This treatment allows genetic variation within a taxon to be included in the model. Monte Carlo simulation for a rooted phylogeny of four taxa has verified the efficacy and consistency of the new method. Application of the method to human population was demonstrated.

Interaction of tubulin with guanosine 5'-O-(1-thiotriphosphate) diastereoisomers: specificity of the alpha-phosphate binding region

The exchangeable nucleotide-binding site of tubulin has been studied using diastereoisomers A (Sp) and B (Rp) of guanosine 5'-O-(1-thiotriphosphate) (GTP alpha S) in which the phosphorus atom to which sulfur is attached is chiral. GTP alpha S(A) (10 microM) nucleated assembly of purified tubulin (20 microM) into microtubules in buffer containing 0.1 M 2-(N-morpholino)ethanesulfonic acid with 3 mM Mg2+ and 1 mM EGTA, pH 6.6 at 37 degrees C. With 0.2 mM GTP alpha S(A), the critical concentration (Cc; minimum protein concentration required for assembly) was 8 microM tubulin. Neither 0.2 mM GTP nor GTP alpha S(B) promoted microtubule assembly in buffer with 0.5-6.75 mM Mg2+ and 20-70 microM tubulin. The Cc values for GTP alpha S-(A)-induced assembly of tubulin in buffer with 30% glycerol and of microtubule protein (tubulin and microtubule-associated proteins) in buffer were lower than for GTP. GTP alpha S(A)-induced microtubules were more stable to the cold and to Ca2+. GTP alpha S(A) and GTP but not GTP alpha S(B) bound tightly to tubulin at 4 degrees C. Although GTP alpha S(B) did not nucleate assembly, it did bind to tubulin since it was incorporated into the growing microtubule. Both isomers were hydrolyzed in the microtubules. These studies show that GTP alpha S(A) promotes tubulin assembly better than GTP and GTP alpha S(B) and that there is stereoselectivity at the alpha-phosphate binding region of tubulin. The stereoselectivity may be due to different MgGTP alpha S(A) and -(B) interactions with tubulin.

Intracellular trafficking in Mycobacterium tuberculosis and Mycobacterium avium-infected macrophages

Despite the potential role of the macrophage in the eradication of invading microbes, Mycobacterium species have evolved mechanisms to ensure their survival and replication inside the macrophage. Particles phagocytosed by macrophages normally will be delivered into acid lysosomal compartments for degradation. Mycobacterium must, in some way, avoid this fate by modulation of their phagosome. Immunoelectron microscopy of macrophages infected with Mycobacterium avium or Mycobacterium tuberculosis indicates that the vacuolar membrane surrounding the bacilli possesses the late endosomal/lysosomal marker, LAMP-1 (lysosomal-associated membrane protein-1), but lacks the vesicular proton-ATPase. Analysis of the intersection of the bacteria-containing vacuoles with the endocytic network of the macrophage supports previous studies indicating that these bacilli restrict the fusion capability of their intracellular compartments. The occurrence of vesicles containing lipoarabinomannan, discrete from those containing Mycobacterium, indicate that material does traffic out from the mycobacterial vacuole. To compensate for this loss of membrane, the vacuole must remain dynamic and fuse with LAMP-1-containing vesicles to maintain the density of this marker.

Intracellular trafficking in Mycobacterium tuberculosis and Mycobacterium avium-infected macrophages

Despite the potential role of the macrophage in the eradication of invading microbes, Mycobacterium species have evolved mechanisms to ensure their survival and replication inside the macrophage. Particles phagocytosed by macrophages normally will be delivered into acid lysosomal compartments for degradation. Mycobacterium must, in some way, avoid this fate by modulation of their phagosome. Immunoelectron microscopy of macrophages infected with Mycobacterium avium or Mycobacterium tuberculosis indicates that the vacuolar membrane surrounding the bacilli possesses the late endosomal/lysosomal marker, LAMP-1 (lysosomal-associated membrane protein-1), but lacks the vesicular proton-ATPase. Analysis of the intersection of the bacteria-containing vacuoles with the endocytic network of the macrophage supports previous studies indicating that these bacilli restrict the fusion capability of their intracellular compartments. The occurrence of vesicles containing lipoarabinomannan, discrete from those containing Mycobacterium, indicate that material does traffic out from the mycobacterial vacuole. To compensate for this loss of membrane, the vacuole must remain dynamic and fuse with LAMP-1-containing vesicles to maintain the density of this marker.

A new approach to gene diagnosis of Duchenne/Becker muscular dystrophy--amplified fragment length polymorphisms

Four (CA)n repeats, located in introns 44, 45, 49 and 50 of the dystrophin gene, were evaluated in Chinese. These loci are highly polymorphic, with polymorphism information contents of 0.872, 0.772, 0.870 and 0.718, respectively. All four loci can be easily amplified and labelled using two duplex PCR reactions with alpha-32P-dCTP and can be detected by denaturing polyacrylamide gel electrophoresis. Using these four loci and the two polymorphic (CA)n repeats located at the 5' and 3' ends of the dystrophin gene, we have developed a new PCR-based procedure--Amp-FLP (amplified fragment length polymorphism) linkage analysis for the gene diagnosis of DMD/BMD. This method can detect intragenic recombination rapidly and efficiently and greatly improves the success rate of carrier detection and prenatal diagnosis in non-deletion DMD/BMD families. All of the loci used in this procedure are intragenic. In addition, the loci in introns 44, 45, 49 and 50 are located in the deletion-prone region of the dystrophin gene, making them valuable and useful in the identification of deletion mutations. Here we report one case of deletion detection using these four loci.

Prenatal diagnosis and carrier detection in mucopolysaccharidosis type II by mutation analysis. A 47,XXY male heterozygous for a missense point mutation

Identification of iduronate-2-sulphatase (IDS) gene mutations in patients with mucopolysaccharidosis type II (MPS II, Hunter syndrome) allows fast and reliable carrier detection and prenatal diagnosis. We describe here three cases of prenatal diagnosis by direct detection of the gene mutation. In addition to two affected male fetuses from two different families, a 47,XXY fetus carrying both the normal and the mutant allele was diagnosed in a third family. The latter pregnancy was carried to term and the child is obviously not affected by MPS II.

Genetic analysis of type 5 capsular polysaccharide expression by Staphylococcus aureus

Capsules are produced by over 90% of Staphylococcus aureus strains, and approximately 25% of clinical isolates express type 5 capsular polysaccharide (CP5). We mutagenized the type 5 strain Reynolds with Tn918 to target genes involved in CP5 expression. From a capsule-deficient mutant, we cloned into a cosmid vector an approximately 26-kb EcoRI fragment containing the transposon insertion. In the absence of tetracycline selection, Tn918 was spontaneously excised, thereby resulting in a plasmid containing 9.4 kb of S. aureus DNA flanking the Tn918 insertion site. The 9.4-kb DNA fragment was used to screen a cosmid library prepared from the wild-type strain. Positive colonies were identified by colony hybridization, and a restriction map of one clone (pJCL19 with an approximately 34-kb insert) carrying the putative capsule gene region was constructed. Fragments of pJCL19 were used to probe genomic DNA digests from S. aureus strains of different capsular serotypes. Fragments on the ends of the cloned DNA hybridized to fragments of similar sizes in most of the strains examined. Blots hybridized to two fragments flanking the central region of the cloned DNA showed restriction fragment length polymorphism. A centrally located DNA fragment hybridized only to DNA from capsular types 2, 4, and 5. DNA from pJCL19 was subcloned to a shuttle vector for complementation studies. A 6.2-kb EcoRI-ClaI fragment complemented CP5 expression in a capsule-negative mutant derived by mutagenesis with ethyl methanesulfonate. These experiments provide the necessary groundwork for identifying genes involved in CP5 expression by S. aureus.

N omega -monomethyl-L-arginine inhibits nitric oxide production in murine cardiac allografts but does not affect graft rejection

Endogenous nitric oxide biosynthesis in mice receiving allogeneic heterotopic heart transplants was monitored as a function of time post-transplant. Nitric oxide production was measured by daily urine nitrate levels and by formation of paramagnetic heme-nitrosyl complexes in the cardiac tissue. Exogenous sources of urine nitrate and EPR signal were minimized by maintaining the animals on a low nitrite/nitrate diet. Urine nitrate peaked on postoperative day 7. A heme-nitrosyl EPR signal also appeared in the cardiac tissue on postoperative day 7 and remained unchanged in size until rejection on postoperative day 9 at which time the peak height of the signal nearly tripled. Some of the animals in the study were treated with the nitric oxide synthase inhibitor, N omega-monomethyl-L-arginine which caused marked inhibition of urinary nitrate excretion and prevented heme-nitrosyl complex formation in beating hearts. However, administration of the inhibitor did not increase graft survival time. Low intensity heme-nitrosyl signals were identified in inhibitor-treated allogeneic hearts after rejection. Syngeneic heart transplants did not induce urinary nitrate excretion nor EPR signal formation. These results show that cytokine induced high output nitric oxide synthesis from L-arginine is a prominent biochemical component of the cell-mediated immune response to cardiac allografts in mice. However, nitric oxide production was not essential for rejection of cardiac allografts mismatched at the major histocompatibility locus.

The ontogeny of morphological differences in the mandible in two inbred strains of mice

We have analyzed the postnatal ontogeny of the mandible of two inbred strains of mice (C3HeB and C57/BL) with conventional statistical analysis of area traits and with Euclidian Distance Matrix Analysis (EDMA). The relative contribution of the distal tooth-bearing part of the mandible to the area of the whole mandible decreases over time. The most prominent differences in shape between mice of 10 days and 25 days postnatal age are found in the lower posterior part of the mandible. Between angular and condylar process intramembranous ossification proceeds at a high rate and gradually fills the space between these two processes. The position of the proximal end of the molar tooth-row is relocated ventrally during this period. Morphological differences between C3H and C57 are most pronounced at 15 days postnatal age. Regions that discriminate best between the two strains change during development. While differences in the coronoid process separate the two groups clearly at 10 and 25 days postnatal age, no significant differences in the coronoid process are found at 20 days postnatal age. Similarly, masseter area shows significant differences at 15 and 25 days postnatal age, while C57 and C3H mice are equivalent for this trait at the other times. The same qualitative results are obtained by Euclidian Distance Matrix Analysis (EDMA): regions of major differences between strains are not consistent among ages. These results suggest that the ontogeny of morphological differences between closely related taxa is quite an erratic process; development of morphometric differences does not proceed smoothly and continuously. This unpredictable pattern of development of morphometric differences is expected if development of the mandible is tightly integrated by epigenetic and regulatory processes.

Calibration of the scanning (atomic) force microscope with gold particles

Scanning force microscopy (SFM) holds great promise for biological research. Two major problems that have confronted imaging with the scanning force microscope have been the distortion of the image and overestimation in measurements of lateral size due to the varying geometry and characteristics of the scanning tip. In this study, spherical colloidal gold particles (10, 20 and 40 nm in diameter) were used to determine (1) tip parameters (size, shape and semi-vertical angle); (2) the distortion of the image caused by the tip; and (3) the overestimation or broadening of lateral dimensions. These gold particles deviate little in size, are rigid and have a size similar to biological macromolecules. Images of the colloidal gold particles by SFM were compared with those obtained by electron microscopy (EM). The height of the gold particles as measured by SFM and EM was comparable and was little affected by the tip geometry. The measurements of the lateral dimensions of colloidal gold, however, showed substantial differences between SFM and EM in that SFM resulted in an overestimate of the lateral dimensions. Moreover, the distortion of images and broadening of lateral dimensions were specific to the SFM tip used. The calibration of the SFM tip with mica provided little clue as to the type of distortion and the amount of lateral broadening observed when the larger gold particles were scanned. The SFM image also depended on the orientation of the tip with respect to the specimen. Our results suggest that quantitative SFM imaging requires calibration to identify and account for both the distortions and the magnitude of lateral broadening caused by the cantilever tip. Calibration with gold particles is fast and nondestructive to the tip. The raw imaging data of the specimen can be corrected for the tip effect and true structural information can be derived. In summary, we present a simple and practical method for the calibration of the SFM tip using gold particles with a size in the range of biomacromolecules that allows: (1) selection of a cantilever tip that produces an image with minimal distortion; (2) quantitative determination of tip parameters; (3) reconstruction of the shape of the tip at different heights from the tip apex; (4) appreciation of the type of distortion that may be introduced by a specific tip and quantification of the overestimation of the lateral dimensions; and (5) calculation of the true structure of the specimen from the image data. The significance is that such calibration will permit quantitative and accurate imaging with SFM.

Effect of buffer addition to high grain total mixed rations on rumen pH, feed intake, milk production, and milk composition

Lactating Holstein cows (n = 56) were fed high grain TMR in three feeding experiments to determine the effects of two rumen buffers on feed intake, milk production, and milk composition. The basal diet in Experiment 1 was 40% grass silage, 12% whole cottonseed, and 48% concentrate with treatments of 1) control (no added buffer), 2) 1.5% of dietary DM as Alkaten, and 3) 1.5% of dietary DM as Rumen 8. In Experiment 2, diets consisted of 12% corn and sunflower silage, 20% whole cottonseed, and 68% concentrate with treatments as in Experiment 1. The diets in Experiment 3 were identical to those in Experiment 2, except that buffers were increased to 2.2% of dietary DM. The DMI was greater for cows fed buffered diets than control diets in Experiments 2 and 3. Milk production was unaffected by treatment. Milk fat percentage was unaffected by diet in Experiment 1 and averaged 3.8%. Milk fat depression was alleviated for cows fed buffered diets in Experiments 2 and 3. No differences in rumen fluid pH or molar percentage of VFA were significant among treatments.

Gene for autosomal dominant congenital stationary night blindness maps to the same region as the gene for the beta-subunit of the rod photoreceptor cGMP phosphodiesterase (PDEB) in chromosome 4p16.3

We studied a large multigeneration Danish family with autosomal dominant congenital stationary night blindness. Both electrophysiological and psychophysical findings in affected family members were identical to those reported in patients from the 'Nougaret family'. The disease locus in the Danish family has now been mapped by demonstrating close linkage without recombination (Q = 0.00 at Zmax = 14.4) to the locus for alpha-L-iduronidase assigned to chromosome 4p16.3. Interestingly the gene for the beta-subunit of the rod photoreceptor cGMP-specific phosphodiesterase maps to the very same chromosomal region.

Partial and conditional maximum likelihood for variance-component estimation

SUMMARY

Patterson and Thompson's idea of 'error contrasts' (or restricted maximum likelihood) (1971) was extended to multiple sets of linear contrasts for variance component estimtion. The error contrasts were established in such a way that only errors are retained in the model. The error variance was then estimated by maximizing the likelihood function obtained from the error contrasts. More sets of linear contrasts were then progressively established such that each set of linear contrasts contains only one class of random effects and the errors. A likelihood function was constructed and maximized for each variance of random effects given the error variance held at its estimated value. The likelihood function for estimating the covariance component between two classes of random effects was established such that all other random effects are treated as fixed effects. The likelihood function was then maximized with respect to the covariance given the two variance components fixed at their estimated values. The multidimensional optimization problem in the traditional restricted maximum-likelihood problem was then turned into several one-dimensional optimization problems by using this technique. Inasmuch as the error variance was estimated using a partial likelihood function and the other variance components are estimated using likelihood functions conditional on the estimated error variance, the method is referred to as partial and conditional maximum likelihood (PCML). ZUSAMMENFASSUNG: Partielle und bedingte Maximum Likelihood zur Schätzung von Varianzkomponenten Die Patterson und Thompson Vorstellungen von 'Fehlerkontrasten' (1971) (oder beschränkte maximale Likelihood) wurde auf multiple Gruppen linearer Kontraste für Varianzkomponenten- schätzung ausgedehnt. Die Fehlerkontraste erfolgen in der Form, daß nur Fehler im Modell verbleiben. Die Fehlervarianz wurde dann durch Maximierung der Likelihood Funktion von Fehlerkontrasten geschätzt. Weitere Gruppen linearer Kontraste wurden nacheinander etabliert dergestalt, daß jede Gruppe linearer Kontraste nur eine Klasse zufälliger Wirkungen und die Fehler enthält. Eine Likelihood Funktion wurde konstruiert und für jede Varianz von Zufallsgrößen maximiert unter der Voraussetzung, daß die Fehlervarianz auf ihrem geschätzten Wert verbleibt. Die Likelihood Funktion zur Schätzung der Ko-Varianzkomponenten zwischen zwei Klassen zufälliger Wirkungen wurde in der Form aufgestellt, daß alle anderen Zufallswirkungen als fixe behandelt werden. Die Likelihood Funktion wurde maximiert im Hinblick auf Ko-Varianz bei gegebenen geschätzten Varianzkomponenten. Das multidimensionale Optimierungsproblem der traditionellen restringierten Maximum Likelihood wurde auf diese Weise in ein eindimensionales Optimierungsproblem verwandelt. Nachdem die Fehlervarianz aus der partiellen Likelihood Funktion und die anderen Varianzkomponenten unter Verwendung der bedingten Likelihood Funktionen geschätzt worden waren, wurde die Methode als partielle und bedingte Maximum Likelihood (pcml) bezeichnet.

Nuclear relaxation of liquids in confinements

We study theoretically the effects of geometrical confinement on the dipolar relaxation of a non-interacting liquid in porous media. Application to the 1H relaxation of methylcyclohexane liquid in porous silica glasses is given. The case of an interacting liquid is considered by molecular dynamics simulations. Geometrical confinement and surface interaction lead to similar frequency behaviour of relaxation rates according to the layering of local density and anisotropy of the molecular mobility.