Identification and validation of quantitative trait loci conferring tan spot resistance in the bread wheat variety Ernie

Tan spot, caused by Pyrenophora tritici-repentis, is a foliar disease of wheat, and it can inflict serious reduction in grain yield and quality. The bread wheat variety Ernie was found to be immune to this disease in Australia, and its genetic control was investigated by quantitative trait loci (QTL) analysis using a doubled haploid population. Eight QTL were identified in this population from three independent trials, and four of them were derived from the parent Ernie. The most significant QTL was located on chromosome arm 2BS, explaining 38.2, 29.8 and 36.2% of the phenotypic variance, respectively, in these trials. The effects of the 2BS QTL were further validated in four additional populations. The presence of this single QTL reduced disease severity by between 29.2 and 67.1% with an average of 50.5%. The significant effects of this QTL and its consistent detection across all the trials with different genetic backgrounds make it an ideal target for breeding programmes as well as for its further characterization. Data from this study also showed that neither plant height nor heading date significantly affects tan spot resistance.

Plant height affects Fusarium crown rot severity in wheat

Effects of plant height on Fusarium crown rot (FCR) disease severity were investigated using 12 pairs of near-isogenic lines (NILs) for six different reduced height (Rht) genes in wheat. The dwarf isolines all gave better FCR resistance when compared with their respective tall counterparts, although the Rht genes involved in these NILs are located on several different chromosomes. Treating plants with exogenous gibberellin increased FCR severity as well as seedling lengths in all of the isolines tested. Analysis of the expression of several defense genes with known correlation with resistance to FCR pathogens between the Rht isolines following FCR inoculation indicated that the better resistance of the dwarf isolines was not due to enhanced defense gene induction. These results suggested that the difference in FCR severity between the tall and dwarf isolines is likely due to their height difference per se or to some physiological and structural consequences of reduced height. Thus, caution should be taken when considering to exploit any FCR locus located near a height gene.

Purification and characterization of an intracellular beta-glucosidase from the protoplast fusant of Aspergillus oryzae and Aspergillus niger

Protoplasts of Aspergillus oryzae 3.481 and Aspergillus niger 3.316 were prepared using cellulose and snail enzyme with 0.6 M NaCl as osmotic stabilizer. Protoplast fusion has been performed using 35% polyethylene glycol 4.000 with 0.01 mM CaCl2. The fused protoplasts have been regenerated on regeneration medium and fusants were selected for further studies. An intracellular beta-glucosidase (EC 3.2.1.21) was purified from the protoplast fusant of Aspergillus oryzae 3.481 and Aspergillus niger 3.316 and characterized. The enzyme was purified 138.85-fold by ammonium sulphate precipitation, DE-22 ion exchange and Sephadex G-150 gel filtration chromatography with a specific activity of 297.14 U/mg of protein. The molecular mass of the purified enzyme was determined to be about 125 kDa by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The enzyme had an optimum pH of 5.4 and temperature of 65 degrees C, respectively. This enzyme showed relatively high stability against pH and temperature and was stable in the pH range of 3.0-6.6. Na+, K+, Ca2+, Mg2+ and EDTA completely inhibited the enzyme activity at a concentration of 10 mM. The enzyme activity was accelerated by Fe3+. The enzyme activity was strongly inhibited by glucose, the end product ofglucoside hydrolysis. The K(m) and V(max) values against salicin as substrate were 0.035 mM and 1.7215 micromol min(-1), respectively.

Identification and validation of a major QTL conferring crown rot resistance in hexaploid wheat

Crown rot (CR), caused by various Fusarium species, is a chronic wheat disease in Australia. As part of our objective of improving the efficiency of breeding CR resistant wheat varieties, we have been searching for novel sources of resistance. This paper reports on the genetic control of one of these newly identified resistant genotypes, 'CSCR6'. A population derived from a cross between CSCR6 and an Australian variety 'Lang' was analyzed using two Fusarium isolates belonging to two different species, one Fusarium pseudograminearum and the other Fusarium graminearum. The two isolates detected QTL with the same chromosomal locations and comparable magnitudes, indicating that CR resistance is not species-specific. The resistant allele of one of the QTL was derived from 'CSCR6'. This QTL, designated as Qcrs.cpi-3B, was located on the long arm of chromosome 3B and explains up to 48.8% of the phenotypic variance based on interval mapping analysis. Another QTL, with resistant allele from the variety 'Lang', was located on chromosome 4B. This QTL explained up to 22.8% of the phenotypic variance. A strong interaction between Qcsr.cpi-3B and Qcsr.cpi-4B was detected, reducing the maximum effect of Qcrs.cpi-3B to 43.1%. The effects of Qcrs.cpi-3B were further validated in four additional populations and the presence of this single QTL reduced CR severity by up to 42.1%. The fact that significant effects of Qcrs.cpi-3B were detected across all trials with different genetic backgrounds and with the use of isolates belonging to two different Fusarium species make it an ideal target for breeding programs as well as for further characterization of the gene(s) involved in its resistance.

Elucidating therapeutic effects on patients with hepatocellular carcinoma and main portal vein thrombosis

BACKGROUND/AIMS

The survival duration for patients diagnosed with hepatocellular carcinoma (HCC) with main portal vein thrombosis (MPVT) was usually less than 3 months. The aim of this study is to elucidate whether treatment can prolong the survival for such patients.

METHODOLOGY

Retrospectively we analyzed the clinical features and outcomes of 63 patients with HCC and MPVT over a 7-year period. Three therapeutic modalities--transcatheter arterial chemotherapy (TAC) with or without radiotherapy (RT), and systemic chemotherapy--were applied.

RESULTS

The patients were divided into two groups: 34 (54%) patients were treated, while the remaining 29 (46%) were not. Multivariate analysis revealed that Child-Pugh class, Okuda stage for HCC and the presence of treatment were the principal factors to predict survival. The survival was significantly longer in treated patients than those untreated both in the Child-Pugh class A or B patients. Significantly longer survival is evident in patients treated by TAC combing RT compared to those underwent TAC alone, systemic chemotherapy or no treatment.

CONCLUSIONS

The survival of Child-Pugh class A or B patients can be extended by the use of an appropriate therapeutic modality. TAC combined with RT did the best benefit to prolong survival in such patients.

The p200 family protein p204 as a modulator of cell proliferation and differentiation: a brief survey

The expression of the murine p200 family protein p204 in numerous tissues can be activated by a variety of distinct, tissue-specific transcription factors. p204 modulates cell proliferation, cell cycling, and the differentiation of various tissues, including skeletal muscle myotubes, beating cardiac myocytes, osteoblasts, chondrocytes, and macrophages. This protein modulates these processes in various ways, such as by (1) blocking ribosomal RNA synthesis in the nucleolus, (2) inhibiting Ras signaling in the cytoplasm, (3) promoting the activity of particular transcription factors in the nucleus by forming complexes with them, and (4) overcoming the block of the activity of other transcription factors by inhibitor of differentiation (Id) proteins. Much remains to be learned about p204, particularly with respect to its expected involvement in the differentiation of several as yet unexplored tissues.

Combined trabeculectomy and cataract extraction versus trabeculectomy alone in primary angle-closure glaucoma

AIMS

To compare the long-term efficacy and safety of combined trabeculectomy and cataract extraction versus trabeculectomy alone in primary angle-closure glaucoma (PACG).

METHODS

Hospital files were retrospectively examined for 99 Chinese PACG patients; 75 patients underwent combined surgery and 24 underwent trabeculectomy alone. Success rates were assessed with the Kaplan-Meier survival analysis. The main outcome was the complete success rate defined as either a >20% reduction in intraocular pressure (IOP) or an IOP that remained below 15 mm Hg, with no medications required.

RESULTS

Patients in the combined group and trabeculectomy group had a mean follow-up period of 25.8 (SD 10.8) months and 31.4 (8.9) months, respectively. Survival analysis showed that the complete success rate at 3 years was 56% in the combined group and 54% in the trabeculectomy group (p = 0.903). There were no significant differences between groups in either IOP or the number of glaucoma medications throughout the 3-year follow-up. The incidences of postoperative complications were similar between groups (p = 0.232). No additional IOP-lowering surgical procedures were required in the combined group, while 13 (54%) eyes in the trabeculectomy group required either cataract extraction or further IOP-lowering surgical procedures (p <0.001).

CONCLUSION

In patients with PACG, the long-term IOP-lowering effect and surgical complications of combined trabeculectomy and cataract extraction are comparable with those of trabeculectomy alone. However, the combined surgery incurred fewer subsequent surgical interventions.

A major QTL conferring crown rot resistance in barley and its association with plant height

Crown rot (CR) is one of the most destructive diseases of barley and wheat. Fusarium species causing CR survive in crop residue and a growing acceptance of stubble retention practices has exacerbated disease severity and yield loss. Growing resistant cultivars has long been recognised as the most effective way to reduce CR damage but these are not available in barley. In a routine screening of germplasm, a barley landrace from China gave the best CR resistance among the genotypes tested. Using a doubled haploid population derived from this landrace crossed to Franklin, we demonstrate that the CR resistance of TX9425 was conditioned by a major QTL. The QTL, designated as Qcrs.cpi-3H, was mapped near the centromere on the long arm of chromosome 3H. Its effect is highly significant, accounting for up to 63.3% of the phenotypic variation with a LOD value of 14.8. The location of Qcrs.cpi-3H was coincident with a major QTL conferring plant height (PH) and the effect of PH on CR reaction was also highly significant. When the effect of PH was accounted for by covariance analysis, the Qcrs.cpi-3H QTL remained highly significant, accounting for over 40% of the phenotypic variation. The existence of such a major QTL implies that breeding barley cultivars with enhanced CR resistance should be feasible.

Fabrication of high-aspect-ratio Fresnel zone plates by e-beam lithography and electroplating

The fabrication of gold Fresnel zone plates, by a combination of e-beam lithography and electrodeposition, with a 30 nm outermost zone width and a 450 nm-thick structure is described. The e-beam lithography process was implemented with a careful evaluation of applied dosage, tests of different bake-out temperatures and durations for the photoresist, and the use of a developer without methylisobutylketone. Electrodeposition with a pulsed current mode and with a specially designed apparatus produced the desired high-aspect-ratio nanostructures. The fabricated zone plates were examined by electron microscopy and their performances were assessed using a transmission X-ray microscope. The results specifically demonstrated an image resolution of 40 nm.

Construction and characterization of the first bacterial artificial chromosome library for the cotton species Gossypium barbadense L

As the second most widely cultivated cotton, Gossypium barbadense is well known for its superior fiber properties and its high levels of resistance to Fusarium and Verticillium wilts. To enhance our ability to exploit these properties in breeding programs, we constructed the first bacterial artificial chromosome (BAC) library for this species. The library contains 167 424 clones (49 920 BamHI and 117 504 HindIII clones), with an estimated average insert size of 130 kb. About 94.0% of the clones had inserts over 100 kb, and the empty clones accounted for less than 4.0%. Contamination of the library with chloroplast clones was very low (0.2%). Screening the library with locus-specific probes showed that BAC clones represent 6.5-fold genome equivalents. This high-quality library provides an additional asset with which to exploit genetic variation for cotton improvement.

Overexpression of PrPC and its antiapoptosis function in gastric cancer

Cellular prion protein (PrP(C)), a glycosylphosphatidylinositol-anchored membrane protein, was found in our lab to be widely expressed in gastric cancer cell lines. In order to evaluate its biological significance in human gastric cancer, we investigated its expression in a large series of gastric tissue samples (n = 124) by immuno histochemical staining with the monoclonal antibody 3F4. Compared with normal tissues, gastric adenocarcinoma showed increased PrP(C) expression, correlated with the histopathological differentiation (according to the WHO and Lauren classifications) and tumor progression (as documented by pTNM staging). To better understand the underlying mechanism, we introduced the PrP(C) and two pairs of RNAi into the poorly differentiated gastric cancer cell line AGS and found that PrP(C) suppressed ROS and slowed down apoptosis in transfected cells. Further study proved that the apoptosis-related protein Bcl-2 was upregulated whereas p53 and Bax were downregulated in the PrP(C)-transfected cells. A reverse effect was observed in PrP(C) siRNA-transfected cells. These results strongly suggested that PrP(C) might play a role as an effective antiapoptotic protein through Bcl-2-dependent apoptotic pathways in gastric cancer cells. Further study into the mechanism of these relationships might enrich the knowledge of PrP, better our understanding of the nature of gastric carcinoma, and further develop possible strategies to block or reverse the development of gastric carcinoma.

A 'Chinese Spring' wheat (Triticum aestivum L.) bacterial artificial chromosome library and its use in the isolation of SSR markers for targeted genome regions

A bacterial artificial chromosome (BAC) library was constructed from the bread wheat (Triticum aestivum L.) genotype 'Chinese Spring' ('CS'). The library consists of 395,136 clones with an estimated average insert size of 157 kb. This library provides an estimated 3.4-fold genome coverage for this hexaploid species. The genome coverage was confirmed by RFLP analysis of single-copy RFLP clones. The CS BAC library was used to develop simple sequence repeat (SSR) markers for targeted genome regions using five sequence-tagged-site (STS) markers designed from the chromosome arm of 3BS. The SSR markers for the targeted genome region were successfully obtained. However, similar numbers of new SSR markers were also generated for the other two homologous group 3 chromosomes. This data suggests that BAC clones belonging to all three chromosomes of homologous group 3 were isolated using the five STS primers. The potential impacts of these results on marker isolation in wheat and on library screening in general are discussed.

Construction of bacterial artificial chromosome libraries and their application in developing PCR-based markers closely linked to a major locus conditioning bruchid resistance in mungbean (Vigna radiata L. Wilczek)

Bacterial artificial chromosome (BAC) libraries have been widely used in different aspects of genome research. In this paper we report the construction of the first mungbean (Vigna radiata L. Wilczek) BAC libraries. These BAC clones were obtained from two ligations and represent an estimated 3.5 genome equivalents. This correlated well with the screening of nine random single-copy restriction fragment length polymorphism probes, which detected on average three BACs each. These mungbean clones were successfully used in the development of two PCR-based markers linked closely with a major locus conditioning bruchid (Callosobruchus chinesis) resistance. These markers will be invaluable in facilitating the introgression of bruchid resistance into breeding programmes as well as the further characterisation of the resistance locus.

Identification of a major locus conferring resistance to powdery mildew (ErysiphepolygoniDC) in mungbean (VignaradiataL. Wilczek) by QTL analysis

A major locus conferring resistance to the causal organism of powdery mildew, Erysiphe polygoni DC, in mungbean (Vigna radiata L. Wilczek) was identified using QTL analysis with a population of 147 recombinant inbred individuals. The population was derived from a cross between 'Berken', a highly susceptible variety, and ATF 3640, a highly resistant line. To test for response to powdery mildew, F7and F8lines were inoculated by dispersing decaying mungbean leaves with residual conidia of E. polygoni amongst the young plants to create an artificial epidemic and assayed in a glasshouse facility. To generate a linkage map, 322 RFLP clones were tested against the two parents and 51 of these were selected to screen the mapping population. The 51 probes generated 52 mapped loci, which were used to construct a linkage map spanning 350 cM of the mungbean genome over 10 linkage groups. Using these markers, a single locus was identified that explained up to a maximum of 86% of the total variation in the resistance response to the pathogen.Key words: mungbean, powdery mildew, Erysiphe polygoni, QTL, molecular markers.

Increased frequency of the mannose-binding lectin LX haplotype in Chinese systemic lupus erythematosus patients

Mannose-binding lectin (MBL) is an important complement-activating protein of the human immune system. As a result of one of three structural gene mutations in exon 1 (variants B, C and D) and/or the presence of a low-efficiency promoter polymorphism, MBL deficiency may be associated with increased susceptibility to infectious diseases and to autoimmune disorders, including systemic lupus erythematosus (SLE). Using a combined approach of heteroduplex generator and polymerase chain reaction, a systematic search for mutations in exon 1 and the promoter region of the MBL gene was performed in a Chinese study population comprising 41 SLE patients and 111 healthy controls. Two alleles, a wild-type allele A and a variant allele B (a previously reported mutation of GGC to GAC at codon 54), were identified in MBL exon 1. The frequency of the B allele (0.15) was higher in the SLE patients than in the healthy controls (0.09), but the difference did not attain statistical significance (P > 0.05). However, for two polymorphisms at positions -550 and -221 in the promoter region, the frequency of the low-MBL-producing haplotype (LX) in the patients (0.2073) was significantly higher than that in the controls (0.0855) (P = 0.003, relative risk = 2.79). Our results suggest that the LX haplotype represents a strong risk factor among Chinese SLE patients. Although of lesser importance, the MBL B allele also may be a risk component in the developing process of SLE in Chinese patients.

Molecular epidemiology of hepatitis B viral serotypes and genotypes in taiwan

Subtypes of hepatitis B virus (HBV) have specific geographic distributions and can serve as epidemiological markers. The relationship of HBV serotypes and genotypes in Taiwan and their correlation with the domiciles of origin in 122 patients with chronic HBV infection were investigated. The serotype of HBV was determined by comparing the surface gene encoding amino acids 22-148 of the major surface protein with published sequences. Genotyping of HBV was performed by polymerase chain reaction-restriction fragment length polymorphism. Serotype adw accounted for 70% (85/122) of all HBVs, with the remaining belonging to serotype adr. All adr HBVs were genotype C, regardless of the patient's domicile. Of the 85 adw HBVs, 69 (81%) were genotype B, 10 (12%) were genotype C, 5 (6%) were genotype F and only 1 (1%) was genotype A. In the 31 patients originating from mainland China, the prevalence of adr/genotype C was higher than in the 91 Taiwanese patients (15/31 vs. 22/91; p < 0.05). The distribution of the HBV serotypes and genotypes was not significantly different between 17 patients born in Taiwan (6 adw/genotype B, 2 adw/genotype C, 1 adw/genotype F and 8 adr/genotype C) and 14 patients born in mainland China (5 adw/genotype B, 2 adw/genotype C and 7 adr/genotype C). Our results indicate that in Taiwan, most HBVs of serotype adw are genotype B, and all HBVs of serotype adr are genotype C. Patients with origins in mainland China have a higher proportion of serotype adr/genotype C infection.

Molecular epidemiology of hepatitis B viral serotypes and genotypes in taiwan

Subtypes of hepatitis B virus (HBV) have specific geographic distributions and can serve as epidemiological markers. The relationship of HBV serotypes and genotypes in Taiwan and their correlation with the domiciles of origin in 122 patients with chronic HBV infection were investigated. The serotype of HBV was determined by comparing the surface gene encoding amino acids 22-148 of the major surface protein with published sequences. Genotyping of HBV was performed by polymerase chain reaction-restriction fragment length polymorphism. Serotype adw accounted for 70% (85/122) of all HBVs, with the remaining belonging to serotype adr. All adr HBVs were genotype C, regardless of the patient's domicile. Of the 85 adw HBVs, 69 (81%) were genotype B, 10 (12%) were genotype C, 5 (6%) were genotype F and only 1 (1%) was genotype A. In the 31 patients originating from mainland China, the prevalence of adr/genotype C was higher than in the 91 Taiwanese patients (15/31 vs. 22/91; p < 0.05). The distribution of the HBV serotypes and genotypes was not significantly different between 17 patients born in Taiwan (6 adw/genotype B, 2 adw/genotype C, 1 adw/genotype F and 8 adr/genotype C) and 14 patients born in mainland China (5 adw/genotype B, 2 adw/genotype C and 7 adr/genotype C). Our results indicate that in Taiwan, most HBVs of serotype adw are genotype B, and all HBVs of serotype adr are genotype C. Patients with origins in mainland China have a higher proportion of serotype adr/genotype C infection.

Direct interaction with contactin targets voltage-gated sodium channel Na(v)1.9/NaN to the cell membrane

The mechanisms that target various sodium channels within different regions of the neuronal membrane, which they endow with different physiological properties, are not yet understood. To examine this issue we studied the voltage-gated sodium channel Na(v)1.9/NaN, which is preferentially expressed in small sensory neurons of dorsal root ganglia and trigeminal ganglia and the nonmyelinated axons that arise from them. Our results show that the cell adhesion molecule contactin binds directly to Na(v)1.9/NaN and recruits tenascin to the protein complex in vitro. Na(v)1.9/NaN and contactin co-immunoprecipitate from dorsal root ganglia and transfected Chinese hamster ovary cell line, and co-localize in the C-type neuron soma and along nonmyelinated C-fibers and at nerve endings in the skin. Co-transfection of Chinese hamster ovary cells with Na(v)1.9/NaN and contactin enhances the surface expression of the sodium channel over that of Na(v)1.9/NaN alone. Thus contactin binds directly to Na(v)1.9/NaN and participates in the surface localization of this channel along nonmyelinated axons.

Elicitor-induced association of isoflavone O-methyltransferase with endomembranes prevents the formation and 7-O-methylation of daidzein during isoflavonoid phytoalexin biosynthesis

The bioactive isoflavonoids of the Leguminosae often are methylated on the 4'-position of their B-rings. Paradoxically, reverse genetic evidence implicates alfalfa isoflavone O-methyltransferase (IOMT) in the biosynthesis of 4'-O-methylated isoflavonoids such as the phytoalexin medicarpin in vivo, whereas biochemical studies indicate that IOMT has strict specificity for methylation of the A-ring 7-hydroxyl of daidzein, the presumed substrate for O-methylation, in vitro. Radiolabeling and isotope dilution studies now confirm that daidzein is not an intermediate in isoflavonoid phytoalexin biosynthesis in alfalfa. Furthermore, protein gel blot analysis and confocal microscopy of a transiently expressed IOMT-green fluorescent protein fusion in alfalfa leaves show that the operationally soluble IOMT localizes to endomembranes after elicitation of the isoflavonoid pathway. We propose that IOMT colocalizes with the endoplasmic reticulum-associated isoflavone synthase cytochrome P450 to ensure rapid B-ring methylation of the unstable 2,4',7-trihydroxyisoflavanone product of isoflavone synthase, thereby preventing its dehydration to daidzein and subsequent A-ring methylation by free IOMT. In this way, metabolic channeling at the entry point into isoflavonoid phytoalexin biosynthesis protects an unstable intermediate from an unproductive metabolic conversion.

Catalytic nucleophilic acyl substitution of anhydrides by amphoteric vanadyl triflate

[reaction--see text] Among four vanadyl species examined, vanadyl triflate was the most efficient catalyst to facilitate nucleophilic acyl substitution of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. By using mixed-anhydride technique, one can achieve oleate and peptide syntheses. In marked contrast to common metal triflates, the amphoteric character of the V=O unit in vanadyl species was proven to be responsible for the catalytic profile in this process.

Molecular cloning and expression of woodchuck granulocyte-macrophage colony stimulating factor

Granulocyte-macrophage colony stimulating factor (GM-CSF) has immunoregulatory and antiviral effects, and may thus be promising for the treatment of chronic hepatitis B. Using woodchuck hepatitis virus (WHV)-infected woodchuck as an animal model to test the efficacy and safety of GM-CSF on the therapy of chronic hepatitis B, woodchuck GM-CSF will be required due to the apparent species-specific activity of GM-CSF. The cDNA of woodchuck GM-CSF was cloned using reverse transcription-polymerase chain reaction (RT-PCR) with primers deriving from highly conserved regions of GM-CSF genes from other species. The deduced amino acids, including the signal peptide, is 138 in length and its identities to human, murine, canine and bovine GM-CSFs are 63, 49, 63, and 63% respectively. The genomic DNA of woodchuck GM-CSF was also cloned by PCR. Its organization is highly homologous to that of human and murine GM-CSF genes, consisting of four exons and three introns. Cloned woodchuck GM-CSF was expressed transiently in 293T cells. The recombinant protein expressed was found to stimulate the growth and differentiation of woodchuck bone marrow cells, indicating the protein expressed by the cloned gene is functional. These results pave the way for future studies on the potential role of GM-CSF for the treatment of chronic hepatitis B by using this animal model.

Order parameter of MgB(2): a fully gapped superconductor

We have measured the low-temperature specific heat C(T) for polycrystalline MgB(2) prepared by high pressure synthesis. C(T) below 10 K vanishes exponentially, which unambiguously indicates a fully opened superconducting energy gap. However, this gap is found to be too small to account for T(c) of MgB(2). Together with the small specific heat jump Delta C/gamma(n)T(c) = 1.09, scenarios such as anisotropic s-wave or multicomponent order parameter are called for. The magnetic field dependence of gamma(H) is neither linear for a fully gapped s-wave superconductor nor H(1/2) for nodal order parameter. It seems that this intriguing behavior of gamma(H) is associated with the intrinsic electronic properties other than flux pinning.

Risk factors for ICU mortality in critically ill patients

BACKGROUND AND PURPOSE

Advances in critical care medicine have increased the chances of survival for patients with severe illness or trauma. However, such patients consume a large proportion of medical resources. This study sought risk factors for mortality that have potential to be modified among patients treated in medical or surgical intensive care units (ICUs).

METHODS

This 6-month prospective observational study was conducted in the medical and surgical ICUs of an 1,800-bed university hospital. All adult patients with an expected ICU stay of 48 hours or more were followed up regularly until discharge from the ICUs, or for 10 weeks during their stay in ICUs.

RESULTS

Of 342 patients enrolled, 77 (22.5%) died during a median follow-up period of 5 days (range, 2-70 days). Among a range of variables at the time of ICU entry or developing during stay in ICUs, 17 were associated with higher mortality rate. Multivariate analysis using a logistic regression model demonstrated that the presence of systemic inflammatory response syndrome (SIRS) at the time of ICU entry (adjusted relative risk, ARR, 2.85; 95% confidence interval, CI, 1.16-7.05), Acute Physiological and Chronic Health Evaluation (APACHE) II score on ICU Day 4 (ARR 1.12 with increment of one score; 95% CI 1.01-1.24), Therapeutic Intervention Scoring System (TISS) score on Day 4 (ARR 1.13 with increment of one score; 95% CI 1.05-1.23), parenteral nutrition (ARR 4.97, 95% CI 1.73-14.26), and nosocomial Candida infection (ARR 3.39, 95% CI 1.12-10.23) were independently associated with ICU mortality.

CONCLUSIONS

In addition to SIRS and the APACHE II and TISS scores, this study found that nosocomial Candida infection and parenteral nutrition were independently associated with mortality after control for admission conditions, severity of illness scores, and interventions.

Lamivudine treatment for hepatitis B reactivation in HBsAg carriers after organ transplantation: a 4-year experience

BACKGROUND

Reactivation of hepatitis B after organ transplantation in hepatitis B surface antigen (HBsAg) carriers may be fatal. In this study, we reported our experience of lamivudine treatment in HBsAg carriers who had post-transplant reactivation of hepatitis B.

METHODS

The patients were 15 men and one woman. Nine received kidney transplants, six received heart transplants, and one received a lung transplant. They developed a reactivation of hepatitis B 1-101 months (median, 14 months) after transplantation. They received lamivudine 100 mg daily on a compassionate-use basis, and had regular follow ups. The median pretreatment total serum bilirubin level was 3.0 mg/dL, and the alanine aminotransferase level was 357 U/L. Four of the 16 patients were positive for HBeAg. The serum hepatitis B virus (HBV) DNA levels were > 3000 pg/mL in 13 (81%) patients. Three were coinfected with hepatitis C virus.

RESULTS

The overall survival rate was 75%. All four fatal cases had a pretreatment total serum bilirubin level of > or = 3 mg/dL. Serum HBV-DNA soon became undetectable in 12 survivors. Of the 12 survivors, after a median treatment period of 101 weeks, a lamivudine-resistant strain with variation in the YMDD motif of the HBV polymerase gene developed in three (25%). None had significant adverse reactions to lamivudine treatment.

CONCLUSIONS

These results indicated that lamivudine is effective in the treatment of post-transplant hepatitis B reactivation, including patients with dual chronic hepatitis B and C. Early recognition of HBV reactivation and prompt lamivudine treatment are important to prevent mortality.

Hepatitis B virus variants in patients receiving lamivudine treatment with breakthrough hepatitis evaluated by serial viral loads and full-length viral sequences

Both viral loads and genome variations have been implicated in the pathogenesis of acute exacerbation of chronic hepatitis B. Hepatitis B exacerbation in patients receiving lamivudine treatment represented a unique setting to clarify their importance. Three organ recipients with posttransplantation hepatitis B exacerbation and 3 patients with chronic hepatitis B were studied. All received lamivudine treatment and their alanine aminotransferase (ALT) levels and hepatitis B virus (HBV) loads were regularly followed. Full-length genomic sequences before and during lamivudine treatment were determined in patients who had breakthrough of serum HBV DNA or elevation of serum ALT. Breakthrough of serum HBV DNA occurred after 6 to 15 months of lamivudine treatment in all. A rapid increase of viral load accompanying the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) variant was followed by hepatitis B exacerbation in each patient. The mean number of nucleotide and amino acid substitutions per genome pair was equivalent in immunosuppressed or immunocompetent patients (6.3 vs. 6.3 for nucleotide, P >.05; 6.0 vs. 6.7 for amino acid, P >.05). Changes of nucleotide and amino acid beyond the YMDD motif were distributed along the whole HBV genome but none occurred within the known B-cell epitopes and human leukocyte antigen class I- or II-restricted T-cell epitopes. Our results suggest that a resurgence of viral load rather than changes of the known immunogenic viral epitopes is more closely associated with the development of hepatitis B exacerbation after the emergence of YMDD variants in patients receiving lamivudine treatment.