Guasha improves knee osteoarthritis by inhibiting chondrocyte apoptosis and regulating expression of autophagy-related genes and proteins in rats

OBJECTIVES

To observe the effect of Guasha on inflammation factors, apoptosis and autophagy in the cartilage tissue of knee joint in rats with knee osteoarthritis (KOA), so as to explore its mechanisms underlying improvement of KOA.

METHODS

A total of 51 male SD rats were randomized into three groups：blank control, KOA model and Guasha (n= 17 in each group) . The rats in the blank control group received intra-articular injection of 0.9% NaCl solution in the right knee joint. The KOA model was established by intraarticular injection of glutamate sodium iodoacetic acid in the right knee joint. For rats of the Guasha group, Guasha (at a frequency of 1 time/s, and an applied pressure of 0.3-0.5 kgf) was applied to "Yanglingquan" (GB34) and "Xuehai"(SP10) areas of the right leg, once every other day, for 7 consecutive sessions. The circumference of the right knee was measured, The histopathological changes of right knee cartilage were observed after H.E. staining. The contents of inflammatory factors interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the right knee articular cartilage tissue were assayed using ELISA. The expression levels of autophagy-related key molecule Beclin-1 (homologous series of yeast Atg6), light chain protease complication 3 type II/I (LC3II/LC3 I), ubiquitin binding factor 62 (P62) and cysteine aspartate protease-3 (Caspase-3) mRNAs and proteins of the right knee articular cartilage tissue were measured using real-time fluorescent quantitative PCR and Western blot, separately. The apoptosis of chondrocytes was assayed using TUNEL staining, and the immunoactivity of LC3 determined using immunofluorescence staining.

RESULTS

After modeling, the right knee circumfe-rence of the model and Guasha groups was significantly increased compared with the blank control group (P<0.01), and after the intervention, the knee circumference of the Guasha group was markedly decreased in comparison with that of the model group (P<0.05). Results of H.E. staining showed obvious degeneration and defects in the cartilage tissue, necrosis of a large number of chondrocytes, fibrous hyperplasia, accompanied by inflammatory cell infiltration, osteoclast increase, fibroplasia and bone trabecular destruction in the model group, which was relatively milder in the Guasha group. Compared with the blank control group, the expression of Beclin-1 and LC3 mRNAs and proteins, and LC immunofluorescence intensity in the right knee articular cartilage tissue were significantly down-regulated (P<0.01, P<0.001), whereas the expression of P62 and Caspase-3 mRNAs and proteins, the apoptosis rate, contents of IL-1β and TNF-α in the right knee articular cartilage tissue considerably increased (P<0.01, P<0.001) in the model group. In contrast to the model group, the Guasha group had an apparent increase in the expression levels of Beclin-1 and LC3 mRNAs and proteins and LC immunofluorescence intensity in the right knee articular cartilage tissue (P<0.05), and a pronounced decrease in the expression of P62 and Caspase-3 mRNAs and proteins, the apoptosis rate, and contents of IL-1β and TNF-α in the right knee articular cartilage tissue (P<0.05, P<0.01).

CONCLUSIONS

Guasha stimulation of GB34 and SP10 can improve joint cartilage damage in KOA rats, which may be associated with its functions in inhibiting the excessive release of inflammatory factors and apoptosis, possibly by down-regulating the expression of P62 and Caspase-3 mRNAs and proteins and up-regulating the expression of Beclin-1 and LC3 mRNAs and proteins, and by promoting autophagy of chondrocytes.

[Clinical effect of free posterior interosseous artery perforator flap carrying superficial vein for reconstructing severe perioral scar hyperplasia and contracture]

Objective: To observe the clinical effect of free posterior interosseous artery perforator flap carrying superficial vein for reconstructing severe perioral scar hyperplasia and contracture. Methods: The retrospective observational study method was used. From August 2019 to March 2023, 11 patients with severe perioral scar hyperplasia and contracture after severe facial burns who met the inclusion criteria were admitted to General Hospital of TISCO (the Sixth Hospital of Shanxi Medical University). All patients were male and aged 23 to 56 years, with an average age of 31.3 years. After the perioral scar was removed and released, the wound area was 3.0 cm×2.0 cm to 10.5 cm×2.0 cm. The free posterior interosseous artery perforator flap carrying superficial vein was used to repair the wound, and the flap incision area was 3.5 cm×2.5 cm to 11.0 cm×2.5 cm. Among them, 6 patients required repair of wounds after resecting scar around ipsilateral upper and lower lips, and the lobular treatment of the flap was conducted. The wound in the flap donor area was directly sutured. After surgery, the survival of the flap and the occurrence of vascular crisis were observed. During follow-up after surgery, the appearance, texture, and color of the flap, the appearance of the flap donor area, and improvements of crooked mouth, drooling, limited mouth opening, and lip valgus in patients were observed. Results: All the flaps in patients completely survived after surgery, with no occurrence of vascular crisis. During follow-up of 6 to 36 months after surgery, the flap was not significantly bloated, was soft in texture, and had a similar color to that of the normal facial skin. Only linear scars were left in the flap donor area, and crooked mouth, drooling, limited mouth opening, and lip valgus in patients were significantly improved. Conclusions: The free posterior interosseous artery perforator flap carrying superficial vein can reconstruct severe perioral scar hyperplasia and contracture, with low incidence of postoperative flap vascular crisis, and the lobular treatment of flaps can repair wounds around unilateral upper and lower lips at the same time. After surgery, the appearance and function of the perioral area are significantly improved. The flap is a good choice for repairing small area of severe perioral scar hyperplasia and contracture.

[Effect of moxibustion and scraping on bioactive substances changes of acupoints in knee osteoarthritis rats]

OBJECTIVE

To compare the effects of moxibustion and scraping of "Yanglingquan" (GB34) and "Xuehai" (SP10) area on changes of bioactive substances in the region of acupoints in rats with knee osteoarthritis (KOA).

METHODS

SD rats were randomly divided into blank, model, moxibustion, scraping, and moxibustion + scraping (combination) groups, with 8 rats in each group. The KOA model was established by injecting 50 μL 0.9% sodium chloride solution into the right knee cavity. Fourteen days after modeling, GB34 and SP10 on the right limb were stimulated by moxibustion (10 min) or scraping (till regional flush) once every other day for 7 times. The mechanical paw withdrawal threshold (PWT) and thermal withdrawal latency (TWL) were tested by Von Frey and hot stabbing instrument, separately. The pathological changes of the right knee joint were observed by HE staining. The serotonin (5-HT) contents of skin tissues in the region of acupoint GB34 and SP10 were detected by ELISA. The expression levels of substance P (SP) and calcitonin gene-related peptide (CGRP) in GB34 and SP10 region skin tissues were detected by Western blot.

RESULTS

Compared with the blank group, the PWT and TWL of the rats in the model group were significantly decreased (P<0.001), while the contents of 5-HT and the expression levels of SP and CGRP in GB34 and SP10 region skin tissues were significantly increased (P<0.001, P<0.01). Following intervention and in comparison the with the model group, the TWL and PWT of rats in the three treatment groups were significantly increased (P<0.01), the content of 5-HT and the expression levels of SP and CGRP in GB34 and SP10 region skin tissues were significantly decreased (P<0.01, P<0.001, P<0.05). Except for the expression levels of CGRP, the above indexes of the combination group were significantly superior to those of the moxibustion and scraping groups (P<0.05, P<0.01). Findings of HE staining showed severe damaged cartilage, few chondrocytes on the surface, with subchondral neovascularization in the model group, which was relatively milder in the moxibustion, scraping, and combination groups.

CONCLUSION

Moxibustion and scraping can relieve knee joint pain in KOA rats, which may be associated with its function in down-regulating the expression levels of SP and CGRP, and the content of 5-HT. The therapeutic effect of moxibustion plus scraping is better than that of moxibustion and scraping alone.

[Associations between gene polymorphisms of signal transducer and activator of transcription 3 and the susceptibility to hepatitis B virus related liver cirrhosis]

To investigate the associations between gene polymorphisms of signal transducer and activator of transcription 3 (STAT3) and liver cirrhosis (LC) after hepatitis B virus (HBV) infection. A case-control study was conducted in 243 patients with hepatitis B cirrhosis (HBV-LC, case group) and 486 HBV-infected subjects without LC (non-LC, control group) collected from January 2018 to September 2020 at the Changsha Central Hospital Affiliated to Nanhua University. Three single nucleotide polymorphisms (SNPs) of STAT3 gene, including rs4796793C>G, rs2293152C>G, and rs1053004T>C were selected through literature and biological information database, and the genotypes were detected by real-time fluorescent quantitative PCR (RFQ-PCR). The distribution differences of STAT3 SNPs genotypes between the two groups were compared using Chi-square test and haplotype analysis was conducted by Shesis online. The proportion of HBV C genotype in HBV-LC patients was significantly higher than that in the control group (80.91% vs. 70.79%, χ²=7.109, P=0.008), while the logarithm of ALT was significantly lower than that of the control group (1.78±0.43 vs. 1.95±0.54, t=3.801, P=0.000). The genotypes distributions of rs4796793, rs2293152, and rs1053004 were not significantly different between HBV-LC and non-LC in overall analysis and stratified analysis by gender (χ²=2.610, 1.505, 0.586, 2.653, 2.685, 1.583, 0.351, 5.388, 0.339, respectively, P>0.05 for each). Among the subjects infected with HBV genotype C, rs1053004 CC (vs. TT) significantly increased the risk of HBV-LC [odds ratio (OR) = 1.40, 95% confidence interval (CI): 1.03-1.91]. Among the HBV-infected subjects with HBeAg negative, rs4796793 GG genotype (vs. CC) and G allele (vs. C) significantly increased the risks of HBV-LC (OR = 2.17, 95%CI: 1.11-4.23; OR = 1.45, 95%CI: 1.06-1.97, respectively). Haplotypes analysis showed that the frequency of haplotype C-G-T composed of rs4796793, rs2293152, and rs1053004 was significantly lower in HBV-LC than that in the control group (non-LC) (27.3% vs. 35.6%, χ²=9.949, P = 0.001). The correlation between STAT3 and HBV-LC is different in HBV-infected subjects with different infection status. The HBV-infected subjects carrying haplotype rs4796793C-rs2293152G-rs1053004T of STAT3 gene have significantly decreased risk of LC.

Effect of Interleukin-17 gene on glomerular ultrastructure and podocyte injury in adriamycin nephropathy rat models

The aim of this study was to investigate the mechanism of interleukin-17 (IL-17) gene in renal tissues of rats suffering from adriamycin (ADM) nephropathy and its effect on the expression level of characteristic proteins, such as Podocalyxin and Nephrin, in podocytes. Sprague-Dawley (SD) rats were randomly divided into a control group (treated with normal saline) and an ADM group (treated with adriamycin). ADM model rats were transfected with lentivirus and divided into a transfection group (transfected with recombinant plasmid IL-17-shRNA) and a negative control group (transfected with plasmid shNC). Coomassie brilliant blue G-250 (CBB) method was adopted to detect the levels of albumin in urine to validate the model. The ultrastructure of rat glomeruli was observed, and the ratio of T helper 17 cells/regulatory T cells (Th17/Treg) was measured by flow cytometry (FCM). The expression levels of IL-17, forkhead box P3 (Foxp3), Nephrin, and Podocalyxin were detected by real-time quantitative PCR (RT-qPCR) and western blot analysis. Results of the study showed that the proteinuria content of the ADM group was significantly higher than that of the control group (P<0.05). In the ADM group, the glomerular basement membrane had uneven thickness and incomplete structure, which showed foot process fusion and electron dense accumulation. However, the glomerular basal membrane in the transfected rats was thin and intact, and a small amount of epithelial foot process fusion and electron density accumulation were observed. The percentages of Th17 cells and IL-17 levels in the ADM group were significantly higher than those in the control group, while the percentages of Treg cells, Foxp3, Nephrin, and Podocalyxin levels were significantly lower than those in the control group (P<0.05). The percentages of Th17 cells, IL-17, Nephrin, and Podocalyxin in the transfection group were significantly higher than those in the ADM group and the negative control group, while the percentages of Treg cells and Foxp3 were significantly lower than those in the ADM group and the negative control group (P<0.05). The results of this study showed that abnormal activation of Th17/IL-17 cells caused podocyte injury and promoted the occurrence and progression of ADM nephropathy. In addition, inhibition of IL-17 gene expression could improve the imbalance of number of Th17 and Treg cells, which may be potentially applied in treatment of patients with primary nephrotic syndrome (PNS).

Anti-aging gene Klotho ameliorates diabetic nephropathy in mice by inhibiting FGF2 signaling pathway

The aim of this study was to observe the expression of Klotho in renal tissues of mice with diabetic ne¬phropathy (DN), and to further explore the effect of Klotho on DN in mice and its mechanism. The 10-week-old mice in this experiment were divided into three groups: heterozygous db/+ mouse group (db/+ group, n=20), homozygous db/db mouse group (db/db group, n=20) and homozygous db/db mice + Klotho group (db/db + Klotho group, n=20). Firstly, Western blotting and immunohistochemical staining were applied to detect the protein expression of Klotho in the renal tissues of diabetic and non-diabetic mice of different ages. Finally, the protein expressions of fibroblast growth factor 2 (FGF2) and E-cadherin in the renal tissues of mice in each group were examined by Western blotting. The protein expression level of Klotho in the renal tissues of mice aged 10 and 16 weeks in the db/db group was remarkably lower than that in yhedb/+ group. In addition, it was found that db/db + Klotho group exhibited a prominently lower degree of interstitial fi¬brosis and content of Collagen I and Collagen III in the renal tissues than db/db group. Furthermore, it was revealed that the overexpression of Klotho could significantly repress the protein expression level of FGF2 but elevate that of E-cadherin in the renal tissues of DN mice. Klotho protein may ameliorate the renal injury and fibrosis in diabetic mice by inhibiting FGF2, so it is expected to become a targeted drug for DN.

Is CuO Suitable for Improving the Electrochemical Properties of g-C₃N₄?

G-C₃N₄ has a bright application prospect as an electrode material of supercapacitors, which makes it a concern. In order to increase the specific capacitance of g-C₃N₄, we consider to combine it with a metal oxide with high theoretical specific capacitance and utilize the synergistic effect. As a common metal oxide, CuO has the characteristics of high theoretical capacitance, high chemical stability, simple preparation and environmental friendliness. A composite containing CuO nanobelts and graphitic C₃N₄ (g-C₃N₄) was successfully synthesized by a chemical precipitation method. Various testing methods were used to explore its composition, microstructure and electrochemical properties to discuss whether CuO is suitable for improving the electrochemical properties of g-C₃N₄.

[The differences of myringoplasty performed in active and inactive nflammatory stage]

Objective:Through comparing of simple underlay myringoplasty performed in active and inactive inflammatory stage of the chronic otitis media, to explore how the tympanic cavity inflammation affect the outcome of the myringoplasty.Method：Forty-six ears were enrolled in active inflammation group (group A,n=46), and 52 ears were enrolled in inactive inflammation group (group B,n=52). All the patients had received the simple underlay technique myringoplasty. The following-up with otoscope and auditory test had been done in post-operative 12 months.Result:There was no statistic difference of gender and age between two groups. The graft taken-up rate of the group A was 87,0%, that of group B was 90,4%, and there was no statistic difference between two groups(P>0.05).There was no statistic difference of auditory threshold in pre-operative period(P>0.05) and the ABG closure in post-operative period(P>0.05)between two groups. The re-perforation rate of the tympanic membrane also has no difference between two groups(P>0.05).Conclusion：There is no difference of the underlay technique myringoplasty between the active inflammatory stage and inactive inflammatory stage. The active inflammatory condition of the tympanic cavity is not the contraindication of the myringoplasty.

Liquid Exfoliation and Electrochemical Properties of WS₂ Nanosheets

Commercial WS2 powders were exfoliated in sodium dodecyl sulfate solution with a combination of ball-milling and sonication. WS2 nanosheets can be uniformly dispersed in the solution. The layers and thicknesses of WS2 nanosheets could be tailored via changing the ball-milling speed. The effects of the ball-milling speed on crystallinity and morphology of the samples were analyzed. The results show that the layer structure of WS2 nanosheets is destroyed and the crystallinity is decreased with increase of the ball-milling rate. The monolayer WS2 nanosheets at 200 rpm are obtained, which are mesoporous with the specific surface area as 5.419 m2 g-1. The specific capacitance and charge/discharge efficiency of WS2 nanosheets at 200 rpm are better than those of other samples. Its specific capacitance under the scanning rate of 20 mV s-1 and the current density of 0.5 A g-1 are 13.46 F g-1 and 22.50 F g-1, respectively. The charge/discharge curve of WS2 nanosheets at 200 rpm is a symmetrical triangle, which shows rapid charge and slow discharge. It means that WS2 nanosheets at 200 rpm has good electrochemical reversibility. The load transfer resistance and the internal series resistance of this sample are 84.60 Ω and 4.18 Ω, respectively.

[Comparison and application of two risk assessment methods for occupational lead exposure risk classification in a lead-acid battery enterprise]

Objective: To apply and compare two risk assessment methods for occupational lead exposure risk classification in a lead-acid battery enterprise. Methods: In April 2013, an occupational health survey was carried out in a lead-acid battery enterprise. Lead smoke and lead dust were tested in the workplace. The risk assessment index system for occupational chemical hazards that was established and optimized by the research group (referred to as "optimized index system" ) , as well as the Singapore semi-quantitative risk assessment model, was used for occupational lead exposure risk classification in the lead-acid battery enterprise. The two risk classification results were analyzed and compared. Results: In the lead smoke risk classification results, the optimized index system classified the raw material group and foundry group workshops as Class I hazardous and the assembling group workshop as Class II hazardous. The Singapore semi-quantitative risk assessment model classified the raw material group workshop as high risk and foundry group and assembling group workshops as extremely high risk. In the lead dust risk classification results, the optimized index system classified the raw material group workshop as Class I hazardous, while the plate painting group, plate cutting group, and assembling group workshops were classified as Class II hazardous. The Singapore semi-quantitative risk assessment model classified the raw material group workshop as medium risk, the plate painting group and plate cutting group workshops as high risk, and the assembling group workshop as extremely high risk. Conclusion: There are some differences in risk assessment of occupational lead exposure between the two risk assessment methods. The optimized index system is comparably more reasonable and feasible, and is highly operable.

Noncollinear magnetic order induced by Dzyaloshinskii-Moriya interaction in oxygen-assisted Pt nanojunctions

Motivated by recent measurement of the magnetism and conductance of the oxygen-assisted Pt nanojunctions, we performed first principle calculations of the magnetic order and electronic transport by explicitly including fully relativistic effects. Our results show that the spin alignment is a cycloidal spiral feature attributed to the Dzyaloshinskii-Moriya interaction, which indicates that the observed magnetism in experiments is of noncollinear nature. The oxygen concentration is the responsible for the switching of the rotational sense of the spiral magnetic order found in oxygen-assisted Pt nanojunctions. Furthermore, the magnetic moments and magnetoresistances vary with oxygen concentration in the chain, which can be used to tune the magnetism and magnetotransport. The oxygen-assisted Pt nanojunctions offer a possibility for spintronic applications in magnetic memory and quantum devices.

Association of methionine synthase gene polymorphisms with wool production and quality traits in Chinese Merino population

Methionine synthase (MTR) plays a crucial role in maintaining homeostasis of intracellular methionine, folate, and homocysteine, and its activity correlates with DNA methylation in many mammalian tissues. Our previous genomewide association study identified that 1 SNP located in the gene was associated with several wool production and quality traits in Chinese Merino. To confirm the potential involvement of the gene in sheep wool production and quality traits, we performed sheep tissue expression profiling, SNP detection, and association analysis with sheep wool production and quality traits. The semiquantitative reverse transcription PCR analysis showed that the gene was differentially expressed in skin from Merino and Kazak sheep. The sequencing analysis identified a total of 13 SNP in the gene from Chinese Merino sheep. Comparison of the allele frequencies revealed that these 13 identified SNP were significantly different among the 6 tested Chinese Merino strains ( < 0.001). Linkage disequilibrium analysis showed that SNP 3 to 11 were strongly linked in a single haplotype block in the tested population. Association analysis showed that SNP 2 to 11 were significantly associated with the average wool fiber diameter and the fineness SD and that SNP 4 to 11 were significantly associated with the CV of fiber diameter trait ( < 0.05). Single nucleotide polymorphism 2 and SNP 5 to 12 were weakly associated with wool crimp. Similarly, the haplotypes derived from these 13 identified SNP were also significantly associated with the average wool fiber diameter, fineness SD, and the CV of fiber diameter ( < 0.05). Our results suggest that is a candidate gene for sheep wool production and quality traits, and the identified SNP might be used in sheep breeding.

Temperature-controlled down-conversion luminescence behavior of Eu3+ -doped transparent MF2 (M = Ba, Ca, Sr) glass ceramics

Eu³⁺ -doped transparent glass ceramics containing MF₂ (M = Ba, Ca, Sr) nanocrystals were fabricated using a melt-quenching method, and the resulting structures were studied using X-ray diffraction. Levels ⁵ D₁ and ⁵ D₀ of Eu³⁺ ions were verified as thermally coupled levels using the fluorescence intensity ratio method. The fluorescence intensity ratios, optical temperature sensitivity and thermal quenching ratios of the transparent glass ceramics were studied as a function of temperature. With an increase in temperature, the relative sensitivity (S_R ) decreased sharply at first, then slowly increased, before finally decreasing. The minimum S_R values of GCBaF₂ (GCB), GCCaF₂ (GCC) and GCSrF₂ (GCS) were 2.8 × 10^-4 , 0.8 × 10^-4 and 1.9 × 10^-4  K^-1 at 360, 269 and 319 K, respectively. Glass ceramics with an intense emission intensity can be used to convert the measured spectrum into temperature and may have an important role in temperature detectors.

Proteomics approach to analyze protein profiling related with ADME/Tox in rat treated with Scutellariae radix and Coptidis rhizoma as well as their compatibility

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellariae radix (Scutellaria baicalensis Georgi) and Coptidis rhizoma (Coptis chinensis Franch), known as traditional Chinese medicine (TCM), have been widely used with the effects of suppressing fever, dispelling dampness, purging fire and removing toxicosis. Owing to their unimaginable complexity, it is difficult to understand their pharmacokinetic properties in detail. The aim of this study was to develop an optimal proteomics approach to analyze the protein profiling related with ADME/Tox in rat liver treated with S. radix and C. rhizoma as well as their compatibility.

MATERIALS AND METHODS

Male rats were respectively administered the extracts of S. radix, C. rhizoma and their mixture for 7 days, and their liver tissue samples were prepared for the comparative proteomic analysis. The significantly differentially expressed proteins between the experimental groups and the control group were found and identified by 2-DE and MALDI-TOF-MS analyses. To validate the proteomic analysis results, glutathion peroxidase, catalase and betaine homocysteine methyl transferase were selected and confirmed by western blotting.

RESULTS

Seventy eight significantly differentially expressed proteins between the experimental groups and the control group were found and identified. By querying the relational databases, the identified differentially expressed proteins were summarized and classified into three groups, phase I drug metabolic enzymes, phase II drug metabolic enzymes and the rest proteins which mainly involve in energy metabolism, signal transduction and cytoskeleton. These proteins involved in ADME/Tox may be the targets for metabolic studies or markers for toxicity.

CONCLUSIONS

Our findings indicated S. radix and C. rhizoma as well as their compatibility can assuredly influence the expression of the proteins in rat liver. After administration, the majority of these expressions presented a downward trend, which may be closely related to the pharmacological properties of the medicine. The method in this study may open up a new road for the complementary tests for ADME/Tox properties of S. radix and C. rhizoma as well as their compatibility.

Long-term antiviral treatment improves hepatic fibrosis in chronic hepatitis B patients

AIM: To observe the impact of long-term antiviral treatment on the degree of liver fibrosis in patients with chronic hepatitis B (CHB).

METHODS: Fifty-six patients with CHB underwent liver biopsy to stage liver fibrosis and received effective antiviral therapy. Five years later, all the patients underwent liver transient elastography to determine FibroScan (FS) value.

RESULTS: HBV DNA was undetectable in 56 patients after treatment, and the percentages of patients with significant fibrosis ( ≥ S2 or F2) (32.1% vs 62.5%, P < 0.01), severe fibrosis ( ≥ S3 or F3) (10.7% vs 33.9%, P < 0.01) and early cirrhosis (S4 or F4) (0% vs 8.9%, P < 0.01) were significantly decreased after treatment. The changes of liver fibrosis degree in patients achieving complete response and incomplete response showed no significant difference (P > 0.05).

CONCLUSION: Long-term effective antiviral treatment can improve liver fibrosis and even reverse early cirrhosis in CHB patients.

Coverage effect on reactivity can be more complicated than what you believe: H2 dissociation on H-precovered Pd(111)

A systematic investigation based on density-functional-theory calculations is presented for elucidating the effect of adatoms on the energetics of H2 dissociation on H-precovered Pd(111) surfaces. Surprisingly, we found that the H-adatoms do not only have a poisoning effect but can also promote H2 dissociation when they are adsorbed on sites which are sufficiently far from the dissociating H2 molecule. The presence of these antagonistic effects produces many crossovers of the minimum energy profiles for H2 dissociation when coverage is varied and thus leads to a quite perplexing picture for the adatom effects. We devised a sorting procedure which allows for rationalizing nicely the influence of H-adatoms on the energetics of H2 dissociation on H-precovered Pd(111) surfaces.

Towards bond selective chemistry from first principles: methane on metal surfaces

Controlling bond-selective chemical reactivity is of great importance and has a broad range of applications. Here, we present a molecular dynamics study of bond selective reactivity of methane and its deuterated isotopologues (i.e., CH(4-x)D(x), x=0,1,2,3,4) on Ni(111) and Pt(111) from first principles calculations. Our simulations allow for reproducing the full C-H bond selectivity recently achieved experimentally via mode-specific vibrational excitation and explain its origin. Moreover, we also predict the hitherto unexplored influence of the molecular translational energy on such a selectivity as well as the conditions under which the full selectivity can be realized for the a priori less active C-D bond.

Revisiting properties of ferroelectric and multiferroic thin films under tensile strain from first principles

First-principles calculations are performed to revisit properties of (001) epitaxial BiFeO(3) (BFO) and PbTiO(3) thin films under tensile strain. While these two films possess different ground states when experiencing no misfit strain, they both exhibit the same, previously unknown phase for tensile strains above ≃5% at T = 0 K. This novel state is of orthorhombic Pmc2(1) symmetry and is macroscopically characterized by a large in-plane polarization coexisting with oxygen octahedra tilting in-phase about the out-of-plane direction. On a microscopic point of view, this Pmc2(1) state exhibits short atomic bonds and zigzag cation displacement patterns, unlike conventional ferroelectric phases and typical domains. Such unusual inhomogeneous patterns originate from the coexistence of polar and antiferroelectric distortions having the same magnitude and lead BFO films to be the first known material for which orbital ordering coexists with a large polarization. Furthermore, this Pmc2(1) state is also found in other perovskite films under tensile strain, which emphasizes its generality.

Coaxial nanocables of codoped double-walled carbon nanotubes

The electronic and optical properties of codoped double-walled carbon nanotubes (DWNTs), in which nucleophilic atoms (potassium) are adsorbed outside the outer tube and electrophilic molecules (NO(2)) are adsorbed inside the inner tube, are investigated by density functional theory. It is found that the inner core tube is p-type doped and the outer shell tube is n-type doped, forming a radial p-n junction of DWNTs. A type-II band energy alignment is formed at the interface of two constituting walls of codoped DWNTs. Moreover, optical calculations show that the band edge absorption is zero for pristine DWNTs, while it is pronounced for the codoped DWNTs. This absorption of codoped DWNTs leads to charge separation in the interface of two walls of DWNTs with holes located on core tube while electrons located on shell one. The properties of DWNT coaxial nanocables demonstrated here can find future applications in electronic and optoelectronic devices.

Duration of feeding linseed diet influences expression of inflammation-related genes and growth performance of growing-finishing barrows

The aim of the study was to investigate the effects of dietary linseed (rich in n-3 PUFA) on expression of inflammation-related genes and on growth performance of growing-finishing barrows. Two isoenergetic and isonitrogenous diets were formulated, one as the basal diet and the other containing 10% linseed. Twenty-four Landrace x Yorkshire barrows weighing 35 +/- 3.7 kg were randomly assigned to 1 of 4 treatment groups, with 6 pigs per group. During the entire experimental period of 90 d, these 4 groups of pigs were first fed the basal diet and then fed the linseed diet for 0, 30, 60, and 90 d before slaughter, respectively. Pig growth; messenger RNA (mRNA) expression of peroxisome proliferator-activated receptor-gamma (PPARgamma), IL-1beta0, IL-6, and tumor necrosis factor-alpha (TNF-alpha); and plasma concentrations of the 3 proinflammatory cytokines were measured and analyzed. Average daily feed intake did not differ among treatment groups (P > 0.05), but ADG (P < 0.05) and G:F (P < 0.01) responded quadratically to the duration of linseed diet feeding, and pigs in the 60-d treatment group had the greatest ADG and G:F. The mRNA expression of PPARgamma in loin muscle and spleen increased linearly (P < 0.01) with the duration of linseed diet feeding, whereas its expression in adipose tissue was not affected (P = 0.095). Tumor necrosis factor-alpha and IL-6 mRNA expression in muscle, adipose, and spleen, as well as serum concentration of TNF-alpha, decreased linearly (P < 0.01) with the duration of linseed diet feeding. Peroxisome proliferator-activated receptor-gamma mRNA abundance was negatively correlated with IL-1beta, IL-6, and TNF-alpha mRNA abundance both in muscle (R(2) = 0.63, P < 0.001) and in spleen (R(2) = 0.69, P < 0.001), and PPARgamma mRNA expression in spleen (R(2) = 0.59, P < 0.01) and muscle (R(2) = 0.52, P < 0.05) was negatively correlated with serum TNF-alpha concentration. There were also significant quadratic relations between ADG and expression of PPARgamma (P < 0.05) and splenic TNF-alpha (P < 0.05). These data suggest that intake of n-3 PUFA from the linseed diet led to significant decreases in the expression of proinflammatory cytokine genes, which may stimulate growth in growing-finishing barrows, at least in part, through a PPARgamma-dependent mechanism.

Localized gap-soliton trains of Bose-Einstein condensates in an optical lattice

We develop a systematic analytical approach to study the linear and nonlinear solitary excitations of quasi-one-dimensional Bose-Einstein condensates trapped in an optical lattice. For the linear case, the Bloch wave in the nth energy band is a linear superposition of Mathieu's functions ce_{n-1} and se_{n} ; and the Bloch wave in the nth band gap is a linear superposition of ce_{n} and se_{n} . For the nonlinear case, only solitons inside the band gaps are likely to be generated and there are two types of solitons-fundamental solitons (which is a localized and stable state) and subfundamental solitons (which is a localized but unstable state). In addition, we find that the pinning position and the amplitude of the fundamental soliton in the lattice can be controlled by adjusting both the lattice depth and spacing. Our numerical results on fundamental solitons are in quantitative agreement with those of the experimental observation [B. Eiermann, Phys. Rev. Lett. 92, 230401 (2004)]. Furthermore, we predict that a localized gap-soliton train consisting of several fundamental solitons can be realized by increasing the length of the condensate in currently experimental conditions.

Al7Ag and Al7Au Clusters with Large Highest Occupied Molecular Orbital−Lowest Unoccupied Molecular Orbital Gap

The candidate structures for the ground-state geometry of the Al(7)M (M = Li, Cu, Ag, and Au) clusters are obtained within the spin-polarized density functional theory. Absorption energy, vertical ionization potential, vertical electron affinity, and the energy gap between the highest occupied molecular orbital (HOMO) level and the lowest unoccupied molecular orbital (LUMO) level have been calculated to investigate the effects of doping. Doping with Ag or Au can lead to a large HOMO-LUMO gap, low electron affinity, and increased ionization potential of Al(7) cluster. In the lowest-energy structure of the Al(7)Au cluster, the Al atom binding to the Al(6)Au acts monovalent and the other six Al atoms are trivalent. Thus, the Al(7)Au cluster has 20 valence electrons, and its enhanced stability may be due to the electronic shell closure effect.

A density-functional study of Al-doped Ti clusters: TinAl (n=1–13)

Equilibrium geometries, stabilities, and electronic properties of TinAl (n = 1-13) clusters have been studied by using density-functional theory with local spin density approximation and generalized gradient approximation. The ground-state structures of TinAl clusters have been obtained. The resulting geometries show that the aluminum atom remains on the surface of clusters for n < 9, but is slowly getting trapped beyond n = 9, meanwhile, the Al atom exhibits a valent transition from monovalent to trivalent. The geometric effects and electronic effects clearly demonstrate the Ti4Al cluster to be endowed with special stability. The studies on the bonds indicate the change from ionic to metalliclike.

Improved method for measurement of human plasma xanthine oxidoreductase activity

The XOR activity in human plasma was measured by quantifying the XOR-derived uric acid (UA) in plasma using the high-performance liquid chromatography (HPLC) equipped with a UV detector. Chromatographic separation consisted of the mobile phase (a mixture of 0.1% trifluoroacetic acid in Milli-Q water and 0.085% trifluoroacetic acid in acetonitrile in a mix ratio of 99:1) running through a Zorbax StableBond SB-C(18) column at a flow-rate of 1 ml/min. Deproteinization with heat-treatment of plasma samples after the reaction was used in the assay to avoid splitting of the UA and xanthine peaks caused by acid deproteinization that could interfere the accurate determination of human plasma XOR activity in our case. Based on the examination of the dependence of XOR activity on added amounts of xanthine and reaction times, the amount of xanthine and reaction time for XOR activity assay were determined to prevent the errors caused by the limiting effect of substrates and plateau phase of the reaction. Using this method, human plasma XOR activities of 25 healthy people were measured. The average human plasma XOR activity was 2.1+/-0.8 (x10(-3) U/ml).

Quantitative assessment of cerebral ventricular volumes in chronic fatigue syndrome

Previous qualitative volumetric assessment of lateral ventricular enlargement in chronic fatigue syndrome (CFS) has provided evidence for subtle structural changes in the brains of some individuals with CFS. The aim of this pilot study was to determine whether a more sensitive quantitative assessment of the lateral ventricular system would support the previous qualitative findings. In this study, we compared the total lateral ventricular volume, as well as the right and left hemisphere subcomponents in 28 participants with CFS and 15 controls. Ventricular volumes in the CFS group were larger than in control groups, a difference that approached statistical significance. Group differences in ventricular asymmetry were not observed. The results of this study provide further evidence of subtle pathophysiological changes in the brains of participants with CFS.

[Establishment of human neuroectodermal tumor cell line (PFSK) with stable expression of xanthine oxidoreductase]

Xanthine Oxidoreductase (XOR) is the key enzyme in purine metabolism and also produces oxygen free radicals. As a continuation of our previous work, in this study, we constructed a retrovirus expression vector (pLNCX2-XOR) containing full length of XOR cDNA. Retrovirus was produced by the virus package cell line PT-67 following the transfection of PT-67 with pLNCX2-XOR and used to infect the human primitive neuroectodermal tumor cell line (PFSK). Infected PFSK cells were selected by G418 to establish cell line with stable expression of XOR. The expression of XOR in the cell line we established was confirmed by RT-PCR, Immunocytochemistry and XOR activity assay.

[Determination of catechol-O-methyltransferase activity in human erythrocytes by high performance liquid chromatography]

A rapid assay method for catechol-O-methyltransferase (COMT) activity in human erythrocyts by high performance liquid chromatography (HPLC) with UV detection was established. Enzyme activity was determined from erythrocyte lysates using S-adenosyl-L-methionine (SAM) as methyl donor and 3, 4-dihydroxybenzoic acid (DBA) as substrate. The 3-O-methylated reaction products were measured by HPLC with UV detection. The linear range of COMT was from 1 U/mL to 60 U/mL with an average RSD < 10%, and the detection limit was 0.5 U/mL(S/N > or = 5).

[HPLC determination of PAHs from electric power plant by UVD-FLD connected in series]

An HPLC method of UVD-FLD connected in series was used to detect naphthalene, biphenyl, fluorene, phenanthrene, anthracene, fluoranthene, 2-methyl-anthracene, chrysene, benzanthracene, benzfluoranthene [b], benzfluoranthene[k], benzopyrene PAH compounds in electricity plant environment. A CLC-ODS column (150 mm x 6.0 mm i.d.) with acetonitrile-water(85:15, V/V) as mobile phase and UV detector set at 250 nm and fluorescent detector set at lambda ex295 nm and lambda em427 nm were used. These 12 PAHs can be separated completely by this method. The earlier eluted eight PAHs were detected by UVD and the rest were detected by FLD. The minimum detectable concentrations of the 12 PAHs were 0.002 mg/L-0.1 mg/L. Satisfactory results were obtained in the analysis of PAH compounds in waste water, flue gas and flyash from several electric power plant in Hunan Province.

Ciliogenesis and left-right axis defects in forkhead factor HFH-4-null mice

Cilia have been classified as sensory or motile types on the basis of functional and structural characteristics; however, factors important for regulation of assembly of different cilia types are not well understood. Hepatocyte nuclear factor-3/forkhead homologue 4 (HFH-4) is a winged helix/forkhead transcription factor expressed in ciliated cells of the respiratory tract, oviduct, and ependyma in late development through adulthood. Targeted deletion of the Hfh4 gene resulted in defective ciliogenesis in airway epithelial cells and randomized left-right asymmetry so that half the mice had situs inversus. In HFH-4-null mice, classic motile type cilia with a 9 + 2 microtubule ultrastructure were absent in epithelial cells, including those in the airways. In other organs, sensory cilia with a 9 + 0 microtubule pattern, such as those on olfactory neuroepithelial cells, were present. Ultrastructural analysis of mutant cells with absent 9 + 2 cilia demonstrated that defective ciliogenesis was due to abnormal centriole migration and/or apical membrane docking, suggesting that HFH-4 functions to direct basal body positioning or anchoring. Evaluation of wild-type embryos at gestational days 7.0 to 7.5 revealed Hfh4 expression in embryonic node cells that have monocilium, consistent with a function for this factor at the node in early determination of left- right axis. Analysis of the node of HFH-4 mutant embryos revealed that, in contrast to absent airway cilia, node cilia were present. These observations indicate that there are independent regulatory pathways for node ciliogenesis compared with 9 + 2 type ciliogenesis in airways, and support a central role for HFH-4 in ciliogenesis and left-right axis formation.

Forkhead transcription factor HFH-4 expression is temporally related to ciliogenesis

Members of the forkhead/winged-helix family of transcription factors are expressed in tissue-specific patterns and play critical roles in development and cell differentiation. The expression of forkhead family member hepatocyte nuclear factor-3/forkhead homologue 4 (HFH-4) has been localized by RNA-blot analysis and in situ hybridization to the proximal airway of the lung (trachea, bronchi, and bronchioles) with onset at mouse embryonic day (E) 14.5 and is present in the choroid plexus, ependymal cells, oviduct, and testis. We hypothesized that the restricted expression of HFH-4 messenger RNA suggests a function common to these tissues and therefore a cell-specific role for HFH-4. Accordingly, an anti-HFH-4 antibody was generated and used for cell-specific localization of protein expression to begin to identify the functions of HFH-4. We found HFH-4 expression in proximal airway ciliated epithelial cells, but not Clara cells or alveolar epithelial cells. HFH-4 was also expressed in ciliated epithelial cells of the nose and paranasal sinuses, choroid plexus, ependyma, and oviduct. In developing mouse lung, HFH-4 expression was initially detected in airway epithelial cells at E15.5, before the appearance of cilia, and at later stages was localized to epithelial cells with cilia. In the testis, HFH-4 expression in spermatids was coincident with stage-specific generation of flagella. The temporal relationship of HFH-4 expression to the development of cilia and flagella, and the restricted expression in ciliated epithelial cells, suggest that this transcription factor has a role in regulation and maintenance of the ciliated cell phenotype in epithelial cells.

Sequencing and characterization of the citrus weevil, Diaprepes abbreviatus, trypsin cDNA. Effect of Aedes trypsin modulating oostatic factor on trypsin biosynthesis

Trypsin mRNA from the citrus weevil, Diaprepes abbreviatus, was reverse transcribed and amplified by PCR. A cDNA species of 513 bp was cloned and sequenced. The 3' and 5' ends of the gene (262 bp and 237 bp, respectively) were amplified by rapid amplification of cDNA ends, cloned and sequenced. The deduced sequence of the trypsin cDNA (860 bp) encodes for 250 amino acids including 11 amino acids of activation and signal peptides and exhibited 16.8% identity to trypsin genes of selected Lepidoptera and Diptera. A three-dimensional model of Diaprepes trypsin contained two domains of beta-barrel sheets as has been found in Drosophila and Neobellieria. The catalytic active site is composed of the canonical triad of His41, Asp92 and Ser185 and a specificity pocket occupied by Asp179 with maximal activity at pH 10.4. Southern blot analysis indicated that at least two copies of the gene are encoded by Diaprepes midgut. Northern blot analysis detected a single RNA band below 1.35 kb at different larval ages (28-100 days old). The message increased with age and was most abundant at 100 days. Trypsin activity, on the other hand, reached a peak at 50 days and fell rapidly afterwards indicating that the trypsin message is probably regulated translationally. Feeding of soybean trypsin inhibitor and Aedes aegypti trypsin modulating oostatic factor affected trypsin activity and trypsin biosynthesis, respectively. These results indicate that Diaprepes regulates trypsin biosynthesis with a trypsin modulating oostatic factor-like signal.

Selective induction of leukemia-associated fusion genes by high-dose ionizing radiation

There is strong clinical and epidemiological evidence that ionizing radiation can cause leukemia by inducing DNA damage. This crucial initiation event is believed to be the result of random DNA breakage and misrepair, whereas the subsequent steps, promotion and progression, must rely on mechanisms of selective pressure to provide the expanding leukemic population with its proliferative/renewal advantage. To investigate the susceptibility of human cells to external agents at the genetic recombination stage of leukemogenesis, we subjected two hematopoietic cell lines, KG1 and HL60, to high doses of gamma-irradiation. The irradiation induced the formation of fusion genes characteristic of leukemia in both cell lines, but at a much higher frequency in KG1 than in HL60. In KG1 cells, the AML1-ETO hybrid gene [associated with the t(8;21) translocation of acute myeloid leukemia] occurred significantly more often than the BCR-ABL [associated with t(9;22) chronic myeloid leukemia] or the DEK-CAN [associated with t(6;9) acute myeloid leukemia] fusion genes. These findings support the notion that ionizing radiation can directly generate leukemia-specific fusion genes but emphasize the differing susceptibility of different cell populations and the differing frequency with which the various fusion genes are formed. The selectivity observed at the primary level of gene fusion formation may explain at least in part the differential risk for development of some but not other forms of leukemia after high-dose radiation exposure.

[Determination of sinomenine HCl in serum and urine by HPLC and its pharmacokinetics in normal volunteers]

A RP-HPLC method was developed to determine the concentrations of sinomenine HCl in serum and urine and its pharmacokinetics was studied in healthy volunteers. C18H37 column was eluted with the mobile phase of acetonitrile--0.01 mol.L-1 sodium phosphate monobasic--N, N, N', N'-tetramethylenediamine (46:54:0.22 v/v, pH 6.9) and the ultraviolet absorbance was monitored at 263 nm. Triazolan was used as internal standard. The calibration curves were linear in the range of 6-480 ng.ml-1 in serum and 0.06-3 micrograms.ml-1 in urine, with mean recoveries of 75.46% and 91.38% respectively. The lowest detectable limits were 4 ng.ml-1 in serum and 40 ng.ml-1 in urine and the RSD for the intra-day and inter-day were less than 5%. A single oral dose of 80 mg sinomenine HCl tablet was given to 8 healthy male volunteers. The concentrations of sinomenine HCl in serum and urine were determined. The serum concentration--time curve was found to fit a two-compartment open model with first order elimination. The pharmacokinetic parameters were: T1/2 alpha 0.791 +/- 0.491 h, T1/2 beta 9.397 +/- 2.425 h, Tmax 1.040 +/- 0.274 h, Cmax 246.604 +/- 71.165 ng.ml-1, AUC 2651.158 +/- 1039.050 ng.h.ml-1, CL 0.033 +/- 0.010 ng.ml-1.

Expression of interferon regulatory factor (IRF) genes and response to interferon-alpha in chronic myeloid leukaemia

Interferon regulatory factors (IRF) 1 and 2 are DNA-binding proteins which control interferon (IFN) gene expression. IRF1 functions as an activator for IFN and IFN-inducible genes, whereas IRF2 represses the action of IRF1. Expression of the two regulatory genes is itself IFN-inducible. Because therapeutic responses of chronic myeloid leukaemia (CML) patients to IFN-alpha may be determined by intracellular levels of these two mutually antagonistic transcription factors, we have devised a competitive reverse-transcription polymerase chain reaction (RT-PCR) assay which provides an estimate of the ratio of IRF1 to IRF2 expression in a given cell population. Analysis of peripheral blood leucocytes from 25 normal individuals showed that the IRF1:IRF2 ratio varied between 1.13 and 2.30 (mean +/- s.d. 1.49 +/- 0.33). Similar values were obtained for normal bone marrow specimens, with no significant difference between CD34+ and CD34- cells. In contrast, the IRF1:IRF2 ratio in leucocytes from CML patients showed a much wider variation (0.53-5.11). Eleven out of 130 patients in chronic phase had ratios above the normal range, whereas none of the 33 blast crisis samples had a ratio >2.5. Analysis of diagnostic specimens in 59 CML patients treated subsequently with IFN-alpha showed a high IRF1:IRF2 ratio of 5.11 in one of two patients who became complete responders; all the 53 patients with minimal or no cytogenetic response had ratios below 2.5. In a separate series of 97 CML patients studied after IFN-alpha therapy a highly significant correlation was found between the IRF1:IRF2 ratio and both the cytogenetic and the molecular response (ie low concentration of BCR-ABL transcripts) to treatment: 53 out of 115 prospectively analysed samples of good cytogenetic responders had ratios above 2.0, as opposed to only 13 out of 91 samples from poor responders (P < 0.0001; chi2 test). We conclude that a high ratio of IRF1/IRF2 expression may be associated with good cytogenetic and molecular response to IFN-alpha in CML.

BCR-ABL-positive lymphoblastoid cells display limited proliferative capacity under in vitro culture conditions

We studied the kinetics of EBV-transformed B-cell lines from patients with chronic myeloid leukaemia (CML) using RT-PCR for BCR-ABL transcripts and immunoglobulin heavy chain (IgH) gene rearrangements. Peripheral blood mononuclear cells, obtained from four patients with CML in chronic phase and from one in accelerated phase, were incubated with supernatant from the B95-8 EBV producing cell line. In 11/25 (44%) B-cell cultures established we demonstrated the presence of BCR-ABL transcripts at intervals ranging from 32 to 125 d post EBV transformation. In all but two cases, evidence of BCR-ABL transcripts disappeared with time. Cultures were initially polyclonal with respect to IgH rearrangements but became progressively oligoclonal, suggesting the longer-term survival of fewer clones, all of which were BCR-ABL negative. We conclude that BCR-ABL-positive lymphoid cultures can be established in the short term from the majority of patients with CML but they have limited capacity to survive in the longer term. Therefore, in lymphoid cells the presence of the BCR-ABL chimaeric gene appears to confer no survival advantage.

Reverse transcription/polymerase chain reaction (RT/PCR) amplification of very small numbers of transcripts: the risk in misinterpreting negative results

Technical modifications of the reverse-transcription/polymerase chain reaction (RT/PCR) amplification method now permit its use to detect amplified products from as few as one abnormal cell, either isolated or mixed with a larger number of normal cells. We studied the reproducibility of such results using as targets low numbers of cells from chronic myeloid leukaemia (CML) patients and CML cell lines in quintuplicate two-step RT/PCR designed to amplify BCR-ABL sequences. When one K562 or KYO1 cell was diluted in 10(3) non-CML HL60 cells, an amplification product was obtained in each test; at greater dilutions BCR-ABL transcripts were detected erratically. Titration of cDNA synthesised from 5 x 10(7) cells from four CML patients showed that whereas positive BCR-ABL sequences could be amplified in some tests starting with as little as a 1 in 10(7) dilution of cDNA template (corresponding to 5-10 cells), the dilution threshold for reproducible amplification was around 1 to 5 in 10(5) (100-500 cells). Quantitative PCR analysis revealed that reactions from 1 in 10(7) diluted cDNA contained less than 10 BCR-ABL transcripts as the starting template. The stochastic nature of the amplification from such small numbers of transcripts was illustrated by results of 10 replicate PCR tests on cDNA from a patient expressing both b3a2 and b2a2 transcripts: dilutions of cDNA up to 1 in 10(5) yielded dual transcript amplification in all 10 tests, but the 1 in 10(7) cDNA dilution resulted in b3a2 and b2a2 products in three tests, b3a2 only in three, b2a2 only in one and no amplification in three tests. We conclude that this 'sampling effect' may yield false-negative results and thus misinterpretation of data regarding assessment of gene expression when the quantity of target material available for study is very small.

Lack of correlation between ABL-BCR expression and response to interferon-alpha in chronic myeloid leukaemia

Interferon-alpha (IFN-alpha) is useful in the treatment of Philadelphia (Ph)-positive chronic myeloid leukaemia (CML). There is, however, a marked heterogeneity among CML patients in relation to their response to IFN-alpha treatment, the reasons for which are unknown. Since the reciprocal ABL-BCR gene is transcriptionally active in only a proportion of CML patients, it has been suggested that response to IFN-alpha may correlate with ABL-BCR expression. In the present study we have tested 209 Ph-positive CML patients for expression of ABL-BCR, BCR-ABL and the normal BCR and ABL genes by reverse transcriptase/polymerase chain reaction (RT/PCR). Whereas BCR-ABL, BCR and ABL transcripts were detected in all the patients, ABL-BCR expression was observed in 59% of the cases. A group of 105 patients within this series was treated with IFN-alpha; 33% achieved a complete or major cytogenetic response (< 35% Ph-positive metaphases) and the remaining 67% showed minimal or no response to IFN-alpha. The proportions of patients who were ABL-BCR positive (63%) and ABL-BCR negative (37%) were the same for good responders and poor responders, suggesting that there is no correlation between ABL-BCR expression and cytogenetic response to IFN-alpha in CML.

Singles transmission in volume-imaging PET with a 137Cs source

The feasibility of a new method of attenuation correction in PET has been investigated, using a single-photon emitter for the transmission scan. The transmission scan is predicted to be more than a factor of ten faster with the singles method than the standard coincidence method, for comparable statistics. Thus, a transmission scan be completed in 1-2 min, rather than 10-20 min, as is common practice with the coincidence method. In addition, a potential advantage of using the single-photon source 137Cs, which has an energy of 662 keV, is that postinjection transmission studies can be performed using energy discrimination to separate the transmission from the emission data at 511 keV. In order to compensate for the energy difference of the attenuation coefficients at 662 keV compared to 511 keV, the transmission images are segmented into two compartments, tissue and lung, and known values (for 511 keV) of attenuation are inserted into these compartments. This technique also compensates for the higher amount of scatter present with the singles method, since it is not possible to use a position gate (based on collinearity of the source and two detector positions) as is commonly done with a positron-emitting source. We have demonstrated, with experimental phantom studies, that the singles transmission method combined with segmentation gives results equivalent both qualitatively and quantitatively to the coincidence method, but requires significantly less time.

Balanced parental contribution to the ABL component of the BCR-ABL gene in chronic myeloid leukemia

Genomic imprinting has recently been associated with the reciprocal t(9;22) chromosome translocation of chronic myeloid leukaemia (CML). This translocation gives rise to a 22q-, or Philadelphia (Ph), chromosome and a derivative 9q+. Based on heterochromatin polymorphisms, it was reported that the former is of maternal and the latter of paternal origin in every case of CML. This parental bias led to the hypothesis that the genes disrupted by the translocation, BCR and ABL, were themselves imprinted, and that in CML the BCR-ABL gene was formed by BCR sequences of maternal and ABL sequences of paternal origin. We have identified a BstNl restriction fragment length polymorphism in the ABL coding sequence which enabled us to investigate directly the expression and inheritance of the two ABL alleles in heterozygous CML patients. Amplification of the specific BCR-ABL and normal ABL mRNA messages by reverse transcriptase-polymerase chain reaction in these patients showed that the ABL moiety of the BCR-ABL gene has an even chance of being the paternal or the maternal copy. We conclude therefore that there is no parental bias in the origin of the translocated ABL gene and no evidence for genomic imprinting of ABL in CML.

Enhanced immunogenicity in mice with hepatitis B vaccine complexed to human hepatitis B immunoglobulin

Purified human hepatitis B immunoglobulin (HBIG) was complexed to plasma derived hepatitis B vaccine (HBVac) at different concentrations and used to immunize Balb/c mice. An enhanced humoral immune response was observed when HBVac was complexed to HBIG in excess of antigen, compared to that immunized with the vaccine alone. Proliferation of splenic lymphocytes was detected when mice were immunized with HBIG complexed to HBVac (0.2-1 microgram), whereas in mice immunized only with HBVac at one microgram, no lymphocyte proliferation was observed. The enhanced immunogenicity of HBIG: HBVac is T cell dependent. The importance of using critical ratio of HBIG and HBVac is indicated, and future application of this complex for vaccination of low- or nonresponders to the present HBVac, as well as for treatment of chronic hepatitis B patients is discussed.

Temperature and Size Variabilities of the Western Pacific Warm Pool

Variabilities in sea-surface temperature and size of the Western Pacific Warm Pool were tracked with 10 years of satellite multichannel sea-surface temperature observations from 1982 to 1991. The results show that both annual mean sea-surface temperature and the size of the warm pool increased from 1983 to 1987 and fluctuated after 1987. Possible causes of these variations include solar irradiance variabilities, EI Niño-Southern Oscillation events, volcanic activities, and global warming.