Mutagenic analysis of AMP nucleosidase from Escherichia coli. Deletion of a region similar to AMP deaminase and peptide characterization by mass spectrometry

AMP nucleosidase (EC 3.2.2.4) from Escherichia coli and AMP deaminase (EC 3.5.4.6) from bakers' yeast are proposed to regulate cellular AMP levels under allosteric control of the activator ATP and the inhibitor, PO4. Both enzymes contain catalytic sites which bind AMP and regulatory sites which bind ATP. The deduced amino acid sequences of the proteins revealed only one region of homology in which six of eight amino acids are identical. A similar sequence is found in glyceraldehyde-3-phosphate dehydrogenase, phoE, ras proteins, RNA polymerase, K(+)-ATPase, nucleolin, and other proteins expected to have nucleotide or phosphate binding properties. In the crystal structure of glyceraldehyde-3-phosphate dehydrogenase, this sequence is part of the NAD(+)-binding site. The function of these amino acids was explored with a deletion mutant of AMP nucleosidase. The protein was over-produced in a pTZ construct using the AMP nucleosidase promoter which resulted in approximately 30% of the total protein as the desired enzyme. The mutation was characterized by DNA sequence analysis and by direct analysis of the peptides using high performance liquid chromatography-mass spectrometry. Deletion of amino acids 128-135, corresponding to DGSELTLD, produced an enzyme with a 20-fold decrease in Vmax but with smaller changes in substrate saturation kinetics, activation by MgATP, inhibition by inorganic phosphate, and inhibition by the tight-binding inhibitor, formycin 5-phosphate. The deletion mutant of AMP nucleosidase exhibits hysteresis in establishing a steady-state rate of product formation which is most pronounced in the absence of MgATP. These results establish that the sequence DGSELTLD in E. coli AMP nucleosidase is not required for binding of AMP, MgATP, or inorganic phosphate. However, the mutant enzyme has a structural defect related to the polymerization state which delays the onset of catalysis and decreases the catalytic efficiency.

Purification and characterization of a nuclear DNA-binding factor complex containing topoisomerase II and chromosome scaffold protein 2

In a search for factors that influence the process of erythroid differentiation at the molecular level, we have identified UB2, a nuclear protein factor that was originally observed for its ability to bind to a very specific and highly conserved sequence motif present in human, mouse, rabbit, and chicken beta-globin genes, as well as carbonic anhydrase I, c-myb, and the immunoglobulin heavy chain enhancer region. It was also observed for its appearance in undifferentiated but not differentiated mouse erythroleukemia cells. Purification of UB2 by DEAE-cellulose chromatography and repeated passages through a DNA affinity column, revealed a complex pattern with three major components of 170, 116, and 48 kDa, respectively. The 170-kDa protein was identified as topoisomerase (topo) II by Western blot analysis, catalytic assays, and antibody interference with UB2 binding. The complex topo II in UB2, however, has a more stringent sequence requirement for DNA binding than does topo II. The 116-kDa protein has been determined to be a proteolytic product of topo II. The chromosome scaffold protein 2 (135 kDa) copurified with UB2, and anti-scaffold protein 2 serum inhibited UB2 binding to DNA.

Interaction of heparin with polyallylamine-immobilized surfaces

A new method to bind ionically and remove heparin from solution and dilute serum is described. Utilizing cellulose diacetate (CA) as the polymer substrate, a cationic polymer chain--poly(allylamine)-PALA--was immobilized directly onto the CA surface and onto the surface using poly(ethylene glycol) (PEG) spacer groups. The ionic interaction between the anionic heparin molecule and the cationic PALA polymer is specific and effective to remove heparin from the bulk solution. The binding properties of heparin onto the PALA and PEG-PALA surfaces were examined. The effects of PEG spacers on heparin binding onto the PALA-immobilized surface were investigated by varying the Mw of PEG spacers. PALA (Mw 8500)-immobilized surfaces exhibited enhanced heparin binding. The maximum heparin binding was observed in the region of PEG Mw 2000-4000. For the high-molecular-weight PALA (Mw 50,000)-immobilized surfaces, heparin binding was independent of the molecular weight of PEG. PEG spacers were also evaluated for their ability to prevent or decrease protein (albumin) adsorption. It was observed that at high albumin concentrations, the adsorption of proteins decreased with increasing chain length of PEG, up to Mw 3400. These observations suggest that low-molecular-weight PALA (Mw 8500)-immobilized CA surfaces with PEG spacers (Mw 3400) may provide increased heparin binding capacity and decreased protein adsorption.

An epidemic outbreak of hepatitis E in Yangon of Myanmar: antibody assay and animal transmission of the virus

An epidemic outbreak of hepatitis E occurred in an army recruit camp of Yangon, Myanmar, in October 1989. One hundred and eleven patients among 600 residents were hospitalized. As high as 83.7% of these patients were positive for the acute phase antibody against hepatitis E virus by an enzyme-linked immunosorbent assay developed in our laboratory. Also, 30.6% of 49 symptom-free residents examined were positive for the antibody. We prepared a stool extract from six patients and inoculated it into 10 rhesus monkeys for a series of three sub-passages. All of them developed acute biochemical hepatitis along with an elevation of antibody levels. A rechallenge with viruses of the present outbreak failed to provoke hepatitis in two monkeys that had previously recovered from acute hepatitis caused by an isolate of sporadic hepatitis E of the same area. Similarly, the rechallenge of the sporadic strain did not induce hepatitis in two monkeys that had been previously infected with the epidemic virus. These data suggested that the subjects would obtain neutralizing antibodies against the hepatitis E virus once infected, and many adult inhabitants of the endemic area had no protective antibodies and were still susceptible to hepatitis E infection.

Sequence and gene structure of the hepatitis E virus isolated from Myanmar

Hepatitis E virus (HEV) is a causative agent of enterically transmitted non-A, non-B hepatitis. Hepatitis E occurs not only in sporadic forms but also in epidemic outbreaks in the developing world. We have revealed the nucleotide and predicted amino acid sequences of full cDNA of HEV isolated from sporadic hepatitis E of Myanmar. The genome is 7194 nucleotides long, followed by a poly(A) tail, and has three open reading frames. The nonstructural gene is located in the 5' terminus, while the structural gene is situated in the 3' terminus. Our HEV strain has 98.5% nucleic acid identity with the HEV strain cloned by workers at Genelabs Incorporated from Myanmar. The difference is point nucleotide substitutions. There is a high degree of nucleotide relatedness among HEVs isolated from the same geographical location.

Nursing diagnoses for psychiatric patients in China

This report describes the development of a preliminary Chinese psychiatric classification system with nine categories and 211 separate diagnoses, and the corresponding diagnostic interview that enables psychiatric nurses in China to systematically assess the presence or absence of the various diagnoses. Using this interview with 30 representative inpatients, the authors identified 152 of the 211 (72%) diagnoses. On average, each patient was given 26 different nursing diagnoses. The interrater reliability of the four nurses who independently coded the diagnostic interview for these 30 patients was excellent: in over 77% of the identified diagnoses the generalized kappa was greater than 0.75. These findings show that further work on this classification of nursing diagnoses is warranted.

Protein tyrosine phosphorylation as an indicator of 2,3,7,8-tetrachloro-p-dioxin exposure in vivo and in vitro

A dose-dependent increase in tyrosine phosphorylation of five hepatic intracellular proteins with approximate molecular weights of 17, 21, 27, 29, and 34 kDa was seen 24 h after administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to C57BL/6J female mice. The ED50 values for tyrosylphosphorylation of these five proteins, respectively, were 0.26, 0.21, 0.26, 0.31, and 0.38 micrograms TCDD/Kg. TCDD induction of 7-ethoxyresorufin O-deethylase activity (EROD) was characterized by an ED50 of 2.5 micrograms/Kg. An eighteen h exposure of a human lymphoblastoma cell line (X3) to TCDD increased tyrosylphosphorylation status of ten proteins with approximate molecular weights of 16, 17, 24, 26, 27, 32, 33, 34, 35, and 36 kDa in a dose-dependent manner. The EC50 values for these TCDD-dependent tyrosylphosphorylation ranged from 0.01 to 0.07 nM TCDD. EROD induction by TCDD in X3 cells exhibited an EC50 of 0.14 nM. These data indicate that TCDD alters intracellular protein tyrosine phosphorylation and these changes are more sensitive biological indicators of TCDD exposure than induction of EROD.

Numerical simulation for the propagation of nonlinear pulsatile waves in arteries

The behavior of nonlinear pulsatile flow of incompressible blood contained in an elastic tube is examined. The theory takes into account the nonlinear convective terms of the Navier-Stokes equations. The motion of the arterial wall is characterized by a set of linearized differential equations. The region bounded by the flexible arterial wall is mapped into a fixed area in which numerical discretization takes place. The finite element method (Galerkin weighted residual approach) is used for the solution of this nonlinear system. The results obtained are pressure distribution, velocity profile, flow rate and wall displacements along the elastic tube (20 cm long).

High-isolation optical isolator using a BiCalnVIG single crystal

To the best of our knowledge this is the first time a new optical isolator has been developed that uses BiCaInVIG, a non-rare-earth iron garnet. The device has high isolation > 40 dB with an insertion loss of 1.0 dB at 1.3-microm wavelength and > 43 dB with 1.1 dB at 1.52-microm wavelength, including Fresnel reflection losses of ~0.8 dB for two polarizers. In addition, the device is inexpensive. In order to adjust maximum isolation when the isolator is assembled, a theoretical basis is presented, and the calculated values are in good agreement with the experimental results.

Sequence comparison of the capsid region of hepatitis E viruses isolated from Myanmar and China

Hepatitis E viruses (HEVs) were isolated during epidemics, one from Myanmar (formerly called Burma) and one from China and were partially sequenced. Another HEV Myanmar strain from sporadic hepatitis was previously sequenced by us. A cDNA sequence comparison was performed among them in the 3'-terminal region, approximately 750-base long. This region contained at least two immunological epitopes and was considered to correspond to the structural protein. The nucleotide sequence identity was 97.2% between the two Myanmar strains and 93.3 and 92.5% between the two Myanmar and the China strain. The deduced amino acid sequence identity ranged from 98.4 to 100.0% among the three strains. Thus this segment was well conserved on the amino acid level among the different strains isolated from these two Asian countries, although the China strain diverged more from the Myanmar strains on the nucleotide sequence level. This data may provide important information for the development of a vaccine and for identification of the virological link between different geographical locations.

Urinary catecholamine excretion and severity of PTSD symptoms in Vietnam combat veterans

In the present study, we replicated and extended our previous findings of increased 24-hour urinary catecholamine excretion in posttraumatic stress disorder (PTSD). Dopamine, norepinephrine, and epinephrine concentrations were measured in 22 male patients with PTSD (14 inpatients and eight outpatients) and in 16 nonpsychiatric normal males. The PTSD inpatients showed significantly higher excretion of all three catecholamines compared with both outpatients with PTSD and normal controls. Dopamine and norepinephrine, but not epinephrine, levels were significantly correlated with severity of PTSD symptoms in the PTSD group as a whole. In particular, these catecholamines seemed related to intrusive symptoms. None of the catecholamines were correlated with severity of depression. The findings support the hypothesis of an enhanced sympathetic nervous system activation in PTSD, and suggest that increased sympathetic arousal may be closely linked to severity of certain PTSD symptom clusters.

[Mechanisms of protective action of radix Salviae miltiorrhizae (RSM) against experimental hepatic injury in rats]

The results indicated that RSM could significantly inhibit the lipid peroxidation of normal livers and cultured hepatocytes of rats, induce liver microsomal cytochrome P450 in normal rats, increase nucleic acids, proteins, urea and cerolloplasmin of damaged cultured hepatocytes of rats, relieve ultrastructural damage of cultured hepatocytes induced by CCl4. The pharmacological actions mentioned above should be considered as important mechanisms of RSM against liver injury.

In vitro and in vivo evaluation of microencapsulated porcine islets

To provide a plentiful supply of pancreatic islets for future clinical transplants into diabetic patients, the authors have developed a simple and consistent method of isolation of porcine islets. Both in vitro and in vivo studies demonstrated that the islets were viable and functional. Xenotransplants of 1.5 x 10(3) - 2.5 x 10(3) of microencapsulated porcine islets into diabetic mice resulted in restoration of normoglycemia in 13 of 18 experimental animals for up to 10 months. A xenograft of 50 x 10(3) microencapsulated porcine islets into a spontaneously diabetic monkey normalized hyperglycemia for more than 150 days. This experiment indicated that the transplantation of encapsulated porcine islets has great potential as a clinical treatment in diabetes mellitus.

[The variations of PRL, LH, FSH and testosterone in renal disease]

Blood PRL was measured with RIA in 22 males and 19 females with various degrees of renal insufficiency. At the same time, blood LH, FSH, testosterone were studied in all the male patients and 20 sex-age matched healthy subjects. The results showed that the levels of PRL and LH were increased, and the level of testosterone was decreased significantly in male uremic patients. There was a significant negative correlation between PRL and testosterone. All the above parameters were measured again 8-25 days after continuous ambulatory peritoneal dialysis (CAPD) therapy in 5 male uremic patients. The BUN and Cr levels decreased and the clinical manifestations of uremia improved, but the levels of PRL, LH, FSH and testosterone showed no significant changes. The mechanisms of these variations were discussed.

[Preliminary study on soilless cultivation techniques of Panax quinquefolium L]

Our experiment has shown 1. Vermiculite with sand (volume 1:1) is a good substrate of soil for American Ginseng. The yield and contents of ginsenoside of American ginseng in this soilless substrate are a little higher than those in ordinary soil. 2. This kind of substrate can be used continuously with fewer occurrences of insect pest and plant diseases and contributes significantly to the reduction of production cost.

Pylorus and antroseromuscular flap-preserving gastrectomy--a new type of reconstruction after subtotal gastrectomy for treatment of gastroduodenal ulcer: clinical and experimental study

To avoid motility disturbances after Billroth gastrectomy, the authors designed pylorus and antroseromuscular flap-preserving subtotal gastrectomy (PAFPG). Results showed that gastric motility and emptying time of dogs after PAFPG were close to normal. PAFPG was applied to 125 consecutive patients with gastroduodenal ulcers (gastric ulcer, 15 patients; duodenal ulcer, 94 patients; and combined ulcers, 16 patients) confirmed by barium examination and fibro-gastroendoscopy. All patients recovered smoothly, none of them had postoperative complication. Gastric acid output reduction rates were as follows: basal acid output, 85.05% +/- 8.13%; maximal acid output, 81.76% +/- 10.85%; peak acid output, 81.42% +/- 10.15%. The incidence of postoperative enterogastric reflux (endoscopically) and the concentration of cholic acids in gastric juice were significantly lower in patients after PAFPG than after Billroth I or II gastrectomy. Results suggest that PAFPG reduced gastric acid outputs definitely and overcame adverse motility consequences after Billroth I or II gastrectomy desirably.

[The preservation capacity of water and fertility of soilless cultivation substrate for Panax quinquefolium L.)]

The preservation capacity of water and fertility of several soilless cultivation substrates for Panax quinquefolium was compared in a large area. The data indicate that vermiculite mixed with sand (volume 1:1) is the most suitable soilless substrate for P. quinquefolium, for it is loose and features good preservation of fertility, water retaining, drainage, and air permeability. Timely analysis of nutrient contents in the substrates during cultivating period may serve as a guideline for correct application of fertilizer.

An MRI perfusion model incorporating nonequilibrium exchange between vascular and extravascular compartments

A model of MRI signal intensity which is a function of perfusion is developed based upon the assumption that biological tissue can be represented by a blood and tissue compartment. The longitudinal magnetization is derived from the Bloch equations which are modified to model the magnetization in both the blood and tissue as a function of the following physiological parameters: blood flow velocity; perfusion fraction, which in the model is parameterized in terms of the ratio of the cross-sectional areas of the tissue and blood compartments; diffusion; rate of exchange between the blood and extravascular tissue compartments. Simulations of slice profiles excited by a repetitive sequence of 90 degrees slice-selective pulses show that the signal intensity in the blood and tissue compartments are modulated by the physiological parameters. A key factor in the modulation of the MRI signal is a time-of-flight effect whereby unexcited spins perfuse the excited region and exchange with blood and tissue compartments, thus immediately increasing the slice signal intensity but also delaying the spin exits from the slice, thereby decreasing their contribution to slice signal intensity in future repetitive pulse measurements.

[Clinical uses of digital subtraction arthrography of the temporomandibular joint]

In the present study, digital subtraction arthrography of TMJ upper cavity was performed in 20 cases with TMJ dysfunction syndrome. It was found that digital subtraction arthrography of TMJ can eliminate various overlapping imaging interference of skull components and has great diagnostic value for TMJ dysfunction syndrome, especially for the diagnosis of small meniscus perforation and the location of meniscus perforation. If this technique can be combined with dynamic observation of TMJ arthrography, the diagnoses for various displacement of meniscus can be made more exactly. However, it is impossible to carry out dynamic observation for TMJ when we use this technique only. This is its disadvantage. Therefore, the best way is to combine arthrographic dynamic observation or arthrographic fluoroscopic observation with digital subtraction arthrography.

[Effects of sodium molybdate on guinea pig atria contractility]

Sodium molybdate (Mo) 10-1000 mumol/L markedly reduced the contratile force of left atria isolated from guinea pig. Mo 100 mumol/L obviously reduced the heart rates in right atria, markedly prolonged the functional refractory period from 185 +/- 12 to 245 +/- 4 ms and inhibited the resting potentiation. Mo 100 and 300 mumol/L reduced the frequency-dependent positive staircase phenomenon. However, verapamil 25 mumol/L reversed the frequency-dependent positive staircase phenomenon to negative one. The mechanism can be explained by the effect on Ca2+ movement in the heart atrium.

[Effects of concentration and ratio of N, P and K on seedlings of Panax quinquefolium L]

Results of the orthogonal experiment of N, P and K are as follows: (1) The highest growth rate occurs in treatment 4 (N100ppm, P25ppm, K250ppm) and other features are also good. So this treatment can be used in hydroponics of seedling of P. quinquefolium. (2) The influences of N, P and K concentration on the contents of ginsenosides in different parts of seedling are different. The content of ginsenosides in aerial part is 14.72-16.72%, higher than 3.24-4.00% in root.

Reflectance diagram-aided technique for optical coating design and monitoring

An amplitude reflectance diagram is a useful tool for visualizing the relationships between the performance of an optical coating and the optical parameters. This paper gives a brief description of the construction and characterization of the reflectance diagrams for different indices. Then, applications of reflectance diagramaided techniques to the design of both phase dispersion-induced narrow reflection and transmission filters, as well as to the optical monitoring of the symmetric multilayers of types (A2BA) and (AB2CBA), are illustrated. Some experimental results of phase dispersion-induced narrowband filters are reported.

Apolipoprotein A-I and A-II levels in an Australian population

Values for apolipoproteins A-I and A-II (apo A-I and apo A-II) are reported for 389 women and 390 men in the town of Busselton, Western Australia. Apo A-I levels were found to be relatively constant with age in men but to rise with age in women. Apo A-II levels remained constant with age in men until older age, when they declined, but rose with age in women, showing a fall in the oldest age group. Apo A-I levels were greater in women than in men, but apo A-II levels were lower in younger women than in younger men, and higher in older women than in older men. On stepwise multiple regression analysis, neither apo A-I nor apo A-II levels showed an independent relationship with age in women; the same was true for apo A-I in men. Alcohol consumption was directly associated with apo A-I and A-II levels in both sexes; adiposity was inversely associated with apo A-I levels in both sexes but with apo A-II only in women. Triglyceride levels showed an inverse association with apo A-II in women. Frequency of exercise was independently and directly associated with apo A-I and A-II levels in women only.

Contemporary rural-urban migration of the Chinese population

The author examines rural-urban migration in China. "The present article provides an estimate of the volume of this population flow since 1949, based on a survey of population flow statistics from 74 cities, and discusses the theories and policies on migration."

Study of different phases in growth cycle of human bone marrow cells and their growth speed, using rat-human cell hybridization, premature chromosome condensation, and sister chromatid differentiation techniques

The cytokinetic activity of bone marrow cells is an indication of hemopoietic status. In the routine examination of bone marrow smears, only M phase can be identified, whereas the different phases of the remainder of the cell cycle are not possible to determine. However, by using premature chromosome condensation and bromodeoxyuridine differential staining techniques, cell stage and cell kinetics can be easily determined. Ninety-eight samples of human bone marrow were collected, cells were hybridized with mitotic M3 cells, and 5016 randomly selected hybrid cells were analyzed for cell stage. Our data demonstrated that 80.37% of the cells were in G1 phase, 12.66% were in S phase, 5.29% were in G2 phase, and 1.68% were in M phase. In specimens that had been cultured for 48 h in the presence of bromodeoxyuridine, 57.46% had completed at least two rounds of DNA replication. In 72-h specimens, 69.27% of the cells had completed at least two S phases. In 96-h specimens, 2S and 2S+ cells occupied 74% of the cell population. The use of cell hybridization techniques, premature chromosome condensation, and bromodeoxyuridine-dependent differential staining revealed the phases of the cell cycle distinctly, as well as the kinetics of cell growth.

[Carcinoembryonic antigen assay in serum and pleural effusion of pulmonary malignancies and benign lesions]

Levels of carcinoembryonic antigen(CEA)in the serum and pleural effusion in malignancies (65) and benign (25) of lung were determined. There are 20 cases of adenocarcinoma, 16 undifferentiated carcinoma, 7 squamous cell carcinoma, 4 alveolar carcinoma, 12 unclassified carcinoma, 1 polymorphous adenoma, 1 mesothelioma, 1 thymoma, 1 metastatic cancer from kidney and 2 metastatic breast cancer. In the benign lesions, there are 20 tuberculosis, 2 heart failure, 1 pneumonia, 1 empyema and 1 cirrhosis. The mean of the CEA level in the serum of lung cancer group was 12.63 ng/ml as compared with that of the tuberculosis group, 3.01 ng/ml (P less than 0.01). The level of CEA in pleural fluid in the lung cancer group was 57.30 ng/ml as compared with that of tuberculosis group, 5.55 ng/ml (P less than 0.01). The content of CEA in the serum and pleural fluid in lung cancer group was remarkably different (P less than 0.01). CEA level in the serum of adenocarcinoma is the highest (mean 15.51 ng/ml). If we set 5 ng/ml as the margin of normal CEA level in serum, the positive rate for cancer would be 54.2%. It is suggested that the margin of CEA normal value be set at 10 ng/ml for the pleural fluid. Higher readings may imply cancer.

Analysis of mouse major urinary protein genes: variation between the exonic sequences of group 1 genes and a comparison with an active gene out with group 1 both suggest that gene conversion has occurred between MUP genes

Here we compare the exonic sequences of four Group 1 mouse major urinary protein (MUP) genes and four Group 1 cDNA sequences. These define seven different nucleotide sequences which differ from each other by 0.35% of bases on average, and which would code for seven different MUP proteins that could probably be resolved physically into at least five classes. The sequences differ at 13 nucleotide positions and at six codons, and although they are closely related their descent cannot be described by a simple series of duplications. We also describe the sequence of another liver cDNA (pMUP15) which has diverged from the Group 1 consensus sequence in 14.6% of bases. The divergence is much greater over exons 1-3 than over exons 4-6, suggesting that an ancestral gene conversion event has occurred. pMUP15 also differs from the Group 1 genes in having a longer signal peptide sequence and a different splice configuration between exons 6 and 7. Unlike the Group 1 sequences, pMUP15 contains a potential N-linked glycosylation site. Other published work has shown that a shorter cDNA clone which is identical over their common sequence to pMUP15 codes for MUP proteins that are unusually large in size and acidic in pI. We show here that mouse urine does indeed contain a glycosylated MUP protein with those properties, presumably the product of the gene that corresponds to pMUP15.

Synthesis of simian virus 40 chromosomes in nuclear extracts from dihydroxyanthraquinone-treated cells

The effect of dihydroxyanthraquinone (DHAQ), a new antitumor drug, on mammalian chromosome replication was investigated using simian virus 40 (SV40) as a model system. The maximum effect of inhibition on viral DNA synthesis was observed within 30-40 min after the addition of the drug. The extent of inhibition of viral DNA synthesis appeared to be directly related to the number of viral replicons which interact with DHAQ molecules in vivo. No apparent strand breakage of SV40 DNA was observed in infected cells treated with DHAQ ranging from 0.3 to 10 microM. However, strand breakage was induced upon cell lysis presumably by released nuclease. Repair of the damaged SV40 chromosomes in vitro resulted in the synthesis of completed supercoiled SV40 DNA. This repair synthesis was mostly confined to the region containing the replication origin of SV40 DNA as judged by the digestion of DNA with restriction endonucleases HindII and HindIII. Since SV40 DNA sequences close to the origin of replication are not complexed with histones to form a nucleosome structure, the results suggested that DHAQ may disturb chromosome structure by interacting preferentially to the nucleosome-free regions and causing the aberrant gene duplication and expression.