Comparison of dynamic ultrasound and stress radiology for assessment of inferior glenohumeral laxity in asymptomatic shoulders

OBJECTIVE

To determine the level of agreement between dynamic ultrasound imaging and stress radiography used for the measurement of inferior glenohumeral laxity in asymptomatic shoulders, and to determine the repeatability of the dynamic ultrasound technique.

MATERIALS AND METHODS

Using a custom-made stress device to apply an inferior displacement force of 90 N, we assessed 20 asymptomatic male subjects for inferior glenohumeral laxity, using stress radiography and dynamic ultrasound. Paired differences between the two methods were evaluated by the 95% limits of agreement method. At a separate session, 19 subjects had inferior glenohumeral laxity assessed by two observers, using dynamic ultrasound. Inter- and intra-observer repeatability was determined for the ultrasound technique.

RESULTS

The mean [(+/-standard deviation (SD)] inferior translation was 4.7+/-4.1 mm by stress radiography and 4.4+/-2.3 mm by dynamic ultrasound. The 95% limits of agreement showed good agreement between the two methods. The paired difference between the two measurement methods varied with the magnitude of the measurement (P<0.001). Intra-observer repeatability of dynamic ultrasound was determined by the use of intra-class correlation coefficients and was 0.94 and 0.89 for the two investigators. Inter-observer repeatability was 0.85. The standard error of the measurement was 0.60 mm and 0.66 mm, for repeated measurements by the two investigators, and 0.85 mm between investigators. Repeatability coefficients demonstrated excellent consistency of measurement between sessions and good consistency between observers.

CONCLUSION

Dynamic ultrasound is a valid and reproducible method for the assessment and quantification of inferior glenohumeral laxity.

Once-weekly intravenous paricalcitol in the treatment of secondary hyperparathyroidism in hemodialysis patients

BACKGROUND

Paricalcitol, a vitamin D analog, is commonly administered three times weekly to control secondary hyperparathyroidism in hemodialysis patients. Less frequent dosing would be more convenient, require less nursing time, and be an option in other dialysis modalities. No studies have examined the efficacy of once-weekly dosing of paricalcitol.

METHODS

Chronic hemodialysis patients receiving a stable dose of paricalcitol three times weekly with intact PTH (iPTH) 100-500 ng/l were monitored during a two-week baseline, then were converted to a single mid-week paricalcitol dose equal to the previous cumulative weekly dose. Serum calcium and phosphorus were monitored weekly and iPTH levels determined during study Weeks 4 and 8. A single paricalcitol dose adjustment was made during study Week 5 based on iPTH to achieve a target value of 150-300 ng/l. Phosphate binders and calcium dialysate bath were kept constant during the study.

RESULTS

In the 25 patients, mean iPTH was 295 +/- 107 ng/l at baseline, and not significantly different at Week 4 (307 +/- 111 ng/l) or Week 8 (285 +/- 98 ng/l). Paricalcitol dose increases mid-study were almost exclusively in patients with iPTH > 300 ng/l. Calcium, phosphorus, and calcium x phosphorus product were not significantly different on weekly therapy. (Only one patient developed a calcium > 2.55 mmol/l during the study.)

CONCLUSION

Once-weekly dosing of paricalcitol is an effective option in treatment of secondary hyperparathyroidism. Less frequent dosing may better allocate nursing time and potentially benefit other patient populations with CKD and ESRD.

Investigation of the use of drained blood reinfusion after total knee arthroplasty: a prospective randomised controlled study

PURPOSE

To compare the use of a blood salvage and reinfusion system with standard allogeneic blood transfusion after total knee arthroplasty--a procedure associated with significant postoperative blood loss.

METHODS

Between June 2002 and May 2004, 60 patients undergoing total knee arthroplasty were randomly allocated into a reinfusion group (n = 26) or a control group (n = 34). Patients in the reinfusion group had their blood reinfused from drains within 6 hours of surgery. Both groups received allogeneic blood transfusions according to specified transfusion criteria if the haemoglobin level fell below 90 g/l, or in the presence of severe anaemic symptoms. Haemoglobin levels and drain output were recorded daily for 3 consecutive days after surgery.

RESULTS

There was no significant difference between the 2 groups in demographic data, drain output, total blood loss, and mean postoperative haemoglobin levels. Significantly more allogeneic blood was required by the control group than by the reinfusion group (p = 0.022).

CONCLUSION

Postoperative reinfusion of drained blood reduced the need for blood transfusion after total knee arthroplasty, while having an effect on postoperative haemoglobin level equivalent to standard allogeneic blood transfusion.

Semiparametric estimation of proportional mean residual life model in presence of censoring

A mean residual life function is the average remaining life of a surviving subject, as it varies with time. The proportional mean residual life model was proposed by Oakes and Dasu (1990, Biometrika77, 409-410) in regression analysis to study its association with related covariates in absence of censoring. In this article, we develop some semiparametric estimation procedures to take censoring into account. The proposed methodology is evaluated via simulation studies, and further applied to a clinical trial of chemotherapy in postoperative radiotherapy of lung cancer patients.

Use of reconstruction nails to manage ipsilateral displaced femoral neck-shaft fractures: assessment of a new approach

PURPOSE

Owing to unpredictable femoral neck reduction, reconstruction nails are not suitable for fixation of group 3 ipsilateral femoral neck-shaft fractures. We developed a new one-step fixation technique to overcome this problem. This study aims to assess this new technique at the Orthopaedic Department, Chi-Mei Foundation Medical Center, Tainan.

METHODS

Of 31 consecutive patients with femoral fractures treated by reconstruction nails, five patients had group 3 ipsilateral femoral neck-shaft fractures, 4 of whom were treated by a new surgical technique. Two 5.0-mm drills were firstly inserted to tether the trochanter fragment, and distal locking screws were secondly applied to immobilise the shaft fracture. The neck-shaft angle was then restored in a closed fashion and proximal cephalomedullary screws were attached. Patients were followed up by post-operative radiography.

RESULTS

All 5 cases of group 3 ipsilateral femoral neck-shaft fracture obtained radiographic union without significant surgical sequelae. Three of the patients had implants removed. No patients presented with osteonecrosis at the 3-year follow-up.

CONCLUSION

The new approach to manage ipsilateral femoral neck-shaft fractures by using reconstruction nails obtains relatively good clinical results.

Identification and characterization of mutations underlying Sanfilippo syndrome type A (mucopolysaccharidosis type IIIA)

Sanfilippo syndrome type A (mucopolysaccharidosis type IIIA; MPS IIIA) is caused by a deficiency of the lysosomal enzyme haparan N-sulphatase (NS). The genomic DNA segments of the NS gene from two Chinese patients with MPS IIIA were amplified by polymerase chain reaction, followed by DNA sequencing to study the molecular lesions. Four mutations (i.e. N42K, D235N, P293S and R377C) and five polymorphisms (i.e. IVS2-72A --> G, IVS2-26T --> C, IVS5+17C --> T, IVS5-37GC --> CTGT and R456H) were identified. Transfection of COS-7 cells with cDNA mutagenized to the corresponding mutations did not yield active enzyme, demonstrating the deleterious nature of the mutations. Western blot analysis revealed a 62-kDa precursor and 56-kDa mature forms for cells transfected with wild-type and polymorphic R456H enzymes. For cells transfected with mutant enzymes, the reduction in precursor and mature forms suggests an increased degradation of the mutant enzymes. The polymorphic DNA haplotype of the NS gene was analysed in 52 unrelated subjects. All five polymorphisms were in Hardy-Weinberg equilibrium. The strong non-random association among the five polymorphisms suggests little or no recombination in the NS gene.

Statistical versus fuzzy measures of variable interaction in patients with stroke

Evidence-based medicine, founded in probability-based statistics, applies what is the case for the collective to the individual patient. An intuitive approach, however, would define structure in the (physiologic) system of interest, the human being, directly relevant to other systems (patients) composed of similar variables. A difference in measure of variable interaction in the patient from that in the collective would show how extrapolation of information from the latter to the single patient is counterintuitive.

METHODS

We compare statistical to 'fuzzy' measures of variable interaction. Three diagnostic variables are considered in 30 stroke patients who underwent the same diagnostic tests. 'Fit' (fuzzy information) values [0, 1] for degree of variable severity were expertly assigned by 2 blinded raters for real and fabricated patients. Fabricated patients were composed of real-patient 'fit' values after shuffling. Real and fabricated patients were each numerically represented as a set. Three groups of fabricated patients and the real patient group were studied. Statistical [Pearson's product-moment (regression analysis) and Spearman's rank correlation] and three different fuzzy measures of variable interaction were applied to patient data.

RESULTS

Interaction for blood-vessel measured strong in real patients, and weak after one shuffle, using all fuzzy measures. By comparison, the same interaction was found in real patients by only 1 rater (Rater 2) using 1 statistical technique (Spearman's rank correlation) which, as did Pearson product-moment correlation, found a 'significant' interaction between blood-heart in fabricated patients.

CONCLUSION

Our study suggests that the measure of variable interaction in nature - as combined in the individual (real) patient - is captured robustly by fuzzy measures and not so by standard statistical measures.

A humanized monoclonal antibody constructed from intronless expression vectors targets human hepatocellular carcinoma cells

An anti-human hepatocellular carcinoma (HCC) monoclonal antibody, hHP-1, was genetically humanized from a murine monoclonal antibody. In this study, a concept of positional template approach was applied to design the amino acid sequence of hHP-1's variable region, and synthetic DNA fragments for protein expression were produced through overlapping PCR from single strand oligonucleotides. Synthetic DNA fragments and human antibody constant region cDNA were used to construct two CMV promotor-based expression vectors for the antibody light and heavy chains, in which the variable region was connected directly to the constant region without an intron sequence. Completely assembled humanized antibody was successfully expressed in mammalian cells as IgG1 kappa molecules and purified using protein A affinity column. The immunogenicity of the hHP1 was estimated by the amino acid sequence and determined through a HAMA (human anti-murine antibody) serum reaction assay. Results indicated that the immunogenicity of hHP-1 was significantly reduced. In vitro binding activity assay showed that the hHP-1 had retained its binding function to a human HCC SMMC-7721 cell-line, without cross binding to other human normal tissues. Immunofluorescence staining showed that hHP-1 had a strong binding activity to SMMC cells. A competitive binding assay showed that the relative binding activity of hHP-1 was approximately 25% binding activity of the original murine antibody. Our results indicate that a humanized antibody could be produced using intronless vectors and expressed as a complete IgG1 kappa antibody. Hence we believe that hHP-1 could be a potential candidate for HCC treatment.

Taxol induced Bcl-2 protein phosphorylation in human hepatocellular carcinoma QGY-7703 cell line

Bcl-2 family proteins play a critical role in the regulation of apoptosis. Treatment of a human hepatocellular carcinoma cell line, QGY-7703, with Taxol induced apoptosis and Bcl-2 protein phosphorylation. Microscopic observation indicated that apoptotic bodies (0-15%) of Taxol-treated QGY cells appeared after 12 h of treatment, and apoptotic QGY cells gradually increased to 40% after 24 h and 70% after 48 h. A DNA fragmentation assay showed that Taxol induced genomic DNA cleavage into 200 bp DNA fragments. Bcl-2 protein was phosphorylated in Taxol-treated QGY cells within 3 h of treatment, and continued gradually up to 24 h. By 48 h, the protein was unphosphorylated. Other Bcl-2 family proteins, including Bax (a heterodimerization partner of Bcl-2), Bcl-XL, Bak and Bad, were expressed, but at constant levels. The results show a close correlation between Bcl-2 phosphorylation and apoptosis in QGY cells. The inactivation of Bcl-2 protein phosphorylation could be one of the key mechanisms needed for the induction of apoptosis in Taxol-treated QGY cells.

Triptolide induced cytotoxic effects on human promyelocytic leukemia, T cell lymphoma and human hepatocellular carcinoma cell lines

Triptolide, a traditional Chinese medicine, has been reported to be effective in the treatment of auto-immune diseases, and it can also induce anti-neoplastic activity on several human tumor cell lines. This study investigates the cytotoxic function and the functional mechanism of triptolide on tumor cells. Promyelocytic leukemia, (HL-60), T cell lymphoma (Jurkat), and human hepatocelluar carcinoma (SMMC-7721) cells were subjected to triptolide treatment, and cell growth inhibition was examined by XTT cell viability assay. Cell death mechanism (apoptosis) was confirmed through DNA fragmentation and DAPI staining. Triptolide inhibited 50% of cell growth (IC(50)) on HL-60 cells at 7.5 nM, Jurkat cells at 27.5 nM and SMMC cells at 32 nM. Characteristic apoptotic features including internucleosomal DNA fragmentation and chromatin condensation were observed in triptolide treated cells. Data from the study indicates that triptolide could induce apoptosis in human tumor cell lines and it may be applicable as a potential chemotherapeutic agent for cancer treatment.

Association of hypertriglyceridemia and insulin resistance in uremic patients undergoing CAPD

OBJECTIVE

Hyperlipidemia is frequently encountered in uremic patients and may be worsened by continuous ambulatory peritoneal dialysis (CAPD) treatment. The lipid abnormalities in these patients may be multifactorial. Insulin resistance (or its compensatory hyperinsulinemia) is commonly observed in uremic patients, but its association with hyperlipidemia in these patients has not been studied.

PATIENTS AND METHODS

Lipid profiles of 35 nondiabetic nonobese patients undergoing CAPD for more than 1 year (mean 52.3 months) were studied. Current laboratory data and parameters related to peritoneal dialysis (PD) within the previous 3 months were recorded. After overnight fasting and interruption of PD, an oral 75-g glucose tolerance test (OGTT) was examined.

RESULTS

After CAPD treatment for more than 12 months, these patients had higher serum triglyceride (TG) (p = 0.001) and total cholesterol (p = 0.0058) levels than their values before commencing CAPD. Twelve of 14 patients with serum TG higher than 200 mg/dL (high-TG) were diagnosed de novo, in contrast with only 1 patient diagnosed of de novo hypercholesterolemia (total cholesterol > 240 mg/dL). There was no difference in age, gender, body mass index (BMI), duration of PD treatment, serum albumin, hematocrit, intact serum parathyroid hormone (iPTH), peritoneal glucose load, solute transport, or weekly Kt/V urea between normal-TG and high-TG patients. After adjusting for age, gender, BMI, weekly Kt/V urea, and iPTH, the high-TG patients had higher levels of area under the curve for glucose (AUC(Glu)), area under the curve for insulin (AUC(Ins)), and AUC(Ins)/AUC(Glu) ratios (F = 10.63, 10.14, and 8.65; p = 0.0029, 0.0035, and 0.0065, respectively), indicating that the high-TG patients were more insulin resistant. There were 24 patients with normal glucose tolerance (NGT), and 11 patients with impaired glucose tolerance (IGT). The IGT group had higher serum TG (F = 10.43, p = 0.003) and total cholesterol (F = 8.05, p = 0.009) than the NGT group, after adjusting for BMI, duration of CAPD treatment, peritoneal glucose load, solute transport, serum albumin, and lipid levels before PD treatment. TheTG levels after CAPD treatment were positively correlated with AUC(Glu), AUC(Ins), and AUC(Ins)/AUC(Glu) ratio (r = 0.48, 0.53, and 0.49; p = 0.0037, 0.001, and 0.0028, respectively).

CONCLUSIONS

These results indicate that insulin resistance is an important factor in the development of hypertriglyceridemia in CAPD patients.

Optimal two-stage designs for clinical trials based on safety and efficacy

In clinical trials designed to evaluate treatment efficacy, it is common practice to terminate a treatment arm in which the observed rate of an adverse event is unacceptably high. This practice may be formalized by a group-sequential test based on a multivariate outcome including both adverse and efficacy events. Recently, Thall and Cheng proposed a family of tests for randomized trials of an experimental treatment versus a standard where patient outcome is bivariate with entries characterizing efficacy and safety. The test is motivated by the idea that clinically meaningful improvements over the standard may be characterized by a two-dimensional parameter quantifying trade-offs between efficacy and safety. We provide optimal two-stage designs based on this test that minimize either the mean sample size under the null hypothesis of no treatment difference, or the maximum sample size if the trial continues to a second stage. A more general group-sequential version of the design also is described, an illustration is provided, and application to the special case of single-arm phase II trials is discussed.

Study of multi-drug resistant mechanisms in a taxol-resistant hepatocellular carcinoma QGY-TR 50 cell line

Cancer chemotherapy with taxol often fails due to acquired resistance of cancer cells, which is frequently associated with an overexpression of P-gp and alterations of beta-tubulin. A taxol-resistant cell line, QGY-TR50, derived from a human hepatocellular carcinoma (HCC) QGY-7703 cell line was used to investigate the mechanisms of taxol-resistance. QGY-TR50 cells showed more than 250-fold resistance to taxol and exhibited cross-resistance to other drugs including actinomycin D, doxorubicin, vinblastine, and vincristine. P-gp was highly expressed in QGY-TR50 cells. Expression levels of five human beta-tubulin isotypes (betaI-, betaII-,betaIII-, betaIva, and betaIvb-tubulin) were examined by real-time semi-quantitative PCR. Comparing with QGY-7703 cells, QGY-TR50 cells did not show any significant change in the expression levels of betaI-, betaIva, and betaIvb-tubulin. While a 1.2-fold increased in betaII-tubulin and a 0.5-fold decreased in betaIII-tubulin levels were observed. All results suggest that the P-glycoprotein could be one key factor involved in enhancing drug resistance in QGY-TR50 cells.

Identification and characterization of two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p

The yeast Saccharomyces cerevisiae Prp19p protein is an essential splicing factor and a spliceosomal component. It is not tightly associated with small nuclear RNAs (snRNAs) but is associated with a protein complex consisting of at least eight proteins. We have identified two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p. Like other identified components of the complex, both Ntc30p and Ntc20p are associated with the spliceosome in the same manner as Prp19p immediately after or concurrently with dissociation of U4, indicating that the entire complex may bind to the spliceosome as an intact form. Neither Ntc30p nor Ntc20p directly interacts with Prp19p, but both interact with another component of the complex, Ntc85p. Immunoprecipitation analysis revealed an ordered interactions of these components in formation of the Prp19p-associated complex. Although null mutants of NTC30 or NTC20 showed no obvious growth phenotype, deletion of both genes impaired yeast growth resulting in accumulation of precursor mRNA. Extracts prepared from such a strain were defective in pre-mRNA splicing in vitro, but the splicing activity could be restored upon addition of the purified Prp19p-associated complex. These results indicate that Ntc30p and Ntc20p are auxiliary splicing factors the functions of which may be modulating the function of the Prp19p-associated complex.

Plasmids encoding foot-and-mouth disease virus VP1 epitopes elicited immune responses in mice and swine and protected swine against viral infection

VP1 is a capsid protein of foot-and-mouth disease virus (FMDV) and contains epitopes of the virus. Plasmids encoding two VP1 epitopes (amino acid residues 141-160 and 200-213) and a host-self immunoglobulin molecule were constructed to produce a new type of FMD DNA vaccine. Two plasmids, namely, pCEIM and pCEIS, containing mouse immunoglobulin (IgG) or swine IgG were subjected to immunogenicity testing in mice and swine, respectively. In mice administrated pCEIM in the abdomen using a genegun, both FMDV-specific T-cell proliferation and neutralizing antibodies were detected. In swine immunized with pCEIS at the back of the ear, immune responses were achieved after the second administration. Swine showed a T-cell proliferative response with a stimulation index (SI) of up to 8.1 and a neutralizing antibody response that was able to protect suckling mice from 10(2) LD(50) (lethal dose 50) FMDV challenge. To compare the immunogenicity of the DNA-based vaccine candidate, versus the protein-based vaccine candidates, a second group of swine was immunized with the protein F1-scIgG, which was encoded by the plasmid pCEIS. Injection with F1-scIgG elicited a T-cell proliferative response of SI < 1.7 and a neutralizing antibody response that protected suckling mice from up to 10(5) LD(50) FMDV challenge. In the challenge test, three of three swine immunized with pCEIS were fully protected from FMDV challenge.

Effects of Bcl-2 and Bcl-XL protein levels on chemoresistance of hepatoblastoma HepG2 cell line

The ratio between apoptotic promoters and repressors in the Bcl-2 family determines the chemosensitivity of cells to apoptotic stimuli. This study examines the chemoresistance of a transfected human hepatoblastoma HepG2 cell-line during Taxol and Doxorubicin application. Sense bcl-2, and anti-sense bcl-XL gene fragments were separately inserted into HepG2 cells via stable transfection. The expression profile of the Bcl-2 family proteins was determined by Western blot analysis. Chemosensitivity of the transfected cells was measured by Trypan blue exclusion assay and XTT reduction assay during drug application. In the absence of Bax protein, HepG2 cells with elevated Bcl-2 protein levels did not exhibit any significant increase in chemosensitivity towards the drugs. Transfected cells with reduced Bcl-XL levels became more sensitive to the drugs, and a significant difference in IC50 values was observed. The chemosensitivity of HepG2 cells to Taxol and Doxorubicin was not affected by Bcl-2 levels, while reduction of Bcl-XL levels rendered the cells more sensitive to the drugs. This suggests that the Bcl-2 protein alone could not protect HepG2 cells from drug-induced apoptosis, and that the Bcl-XL protein may be a target for gene therapy in hepatoblastoma treatment.

An immunoglobulin G based chimeric protein induced foot-and-mouth disease specific immune response in swine

Epitopes containing the residues 141aa-160aa and 200aa-213aa from foot-and-mouth disease (FMD) serotype O1K HK type FMDV VP1 were joined to a swine immunoglobulin G single heavy chain constant region (scIgG), creating a novel chimeric protein, named F1-scIgG. In this study, inoculation with F1-scIgG induced both FMD virus-neutralizing antibody response and T cell response in swine. Antisera from these F1-scIgG-inoculated swine protected suckling mice against 1000 lethal dose 50 (1000LD(50)) FMD challenge. F1-scIgG-inoculated swine were also fully protected against 50LD(50) FMD virus challenge. The present study demonstrates the clear potential for viral epitopes linked with self-Ig in novel FMD vaccine design.

Bim1p/Yeb1p mediates the Kar9p-dependent cortical attachment of cytoplasmic microtubules

In Saccharomyces cerevisiae, positioning of the mitotic spindle depends on the interaction of cytoplasmic microtubules with the cell cortex. In this process, cortical Kar9p in the bud acts as a link between the actin and microtubule cytoskeletons. To identify Kar9p-interacting proteins, a two-hybrid screen was conducted with the use of full-length Kar9p as bait, and three genes were identified: BIM1, STU2, and KAR9 itself. STU2 encodes a component of the spindle pole body. Bim1p is the yeast homologue of the human microtubule-binding protein EB1, which is a binding partner to the adenomatous polyposis coli protein involved in colon cancer. Eighty-nine amino acids within the third quarter of Bim1p was sufficient to confer interaction with Kar9p. The two-hybrid interactions were confirmed with the use of coimmunoprecipitation experiments. Genetic analysis placed Bim1p in the Kar9p pathway for nuclear migration. Bim1p was not required for Kar9p's cortical or spindle pole body localization. However, deletion of BIM1 eliminated Kar9p localization along cytoplasmic microtubules. Furthermore, in the bim1 mutants, the cytoplasmic microtubules no longer intersected the cortical dot of Green Fluorescent Protein-Kar9p. These experiments demonstrate that the interaction of cytoplasmic microtubules with the Kar9p cortical attachment site requires the microtubule-binding protein Bim1p.

Arsanilic acid-Sepharose chromatography of pyruvate kinase from KB cells

In the present study, arsanical-based affinity chromatography for pyruvate kinase (PK) isolation was explored. p-Arsanilic acid (4-aminophenyl arsonic acid), which contains an arsonic acid moiety structurally similar to inorganic pentavalent arsenate, was conjugated to Sepharose 4B via its para-amino group to form an As(V)-Sepharose matrix. The cellular proteins from KB cells bound to arsonic acid moieties were eluted by 50 mM sodium arsenate in Tris-HCl buffer (50 mM, pH 7.6). A single protein band with a molecular mass of 58 kDa was shown on a sodium dodecyl sulfate-polyacrylamide gel. By immunoblotting, amino acid sequencing and enzymatic analysis, the sodium arsenate-eluted 58-kDa protein was demonstrated to be a human PK (type M2). By using this one-step As(V)-Sepharose chromatography, PK from KB cells was purified 35.4-fold with a specific activity of 153.15 U/mg protein in the presence of 6 mM fructose-1,6-biphosphate. Although PK was eluted from an As(V)-Sepharose column with sodium arsenate, PK activity was apparently inhibited by the used eluent system, but not by p-arsanilic acid, indicating a specific interaction of As(V) to PK. In summary, our results indicate that As(V)-Sepharose can serve as a simple and efficient chromatographic support for PK purification from KB cells.

Expression of Bcl-2 family proteins during chemotherapeutic agents-induced apoptosis in the hepatoblastoma HepG2 cell line

This study demonstrates that two anticancer drugs, taxol and doxorubicin (Dox), can kill human hepatoblastoma HepG2 cells in a dose-dependent manner via the induction of apoptosis. Characteristic events, including externalization of phosphatidylserine, cytoplasmic shrinkage, chromatin condensation and DNA degradation, were observed in a large majority of the drug-treated cells. DNA fragmentation showed that a ladder of DNA fragments of approximately 200 bp multiples was observed in taxol-treated, but not in Dox-treated, cells. In addition, the expression patterns of Bcl-2 family members during taxol or Dox treatment were investigated. Results from Western blot analysis indicated that HepG2 cells did not express either the death repressor Bcl-2, or the death promoters Bcl-XS and Bax. However, during the apoptotic process one death repressor, Bcl-XL, and two death promoters, Bak and Bad, were expressed. The expression levels of Bcl-XL and Bak remained unchanged, whereas the level of Bad was down-regulated. As the ratio between death repressors and death promoters in the Bcl-2 family will determine the sensitivity of cells to apoptotic stimuli, the findings suggest that the changed expression patterns of Bcl-2 family proteins caused by anticancer drugs in liver cancer cells may be involved in chemoresistance.

Endobronchial mass in a patient with Burkholderia pseudomallei infection

INTRODUCTION

Burkholderia pseudomallei infection, the great mimicker of infectious diseases, has protean clinical manifestations.

CLINICAL PICTURE

A 37-year-old man who presented with community-acquired pneumonia affecting the right upper lobe had unremitting fever. Bronchoscopy showed an endobronchial mass in the right upper lobe bronchus.

TREATMENT

Intravenous ceftriaxone and oral erythromycin, with empiric antituberculous treatment added later. This was subsequently switched to intravenous ceftazidime and oral doxycycline after the diagnosis was made.

OUTCOME

There was resolution of the endobronchial mass.

CONCLUSION

This case illustrates a unique and unreported presentation of melioidosis.

Confidence bands for cumulative incidence curves under the additive risk model

In the context of competing risks, the cumulative incidence function is often used to summarize the cause-specific failure-time data. As an alternative to the proportional hazards model, the additive risk model is used to investigate covariate effects by specifying that the subject-specific hazard function is the sum of a baseline hazard function and a regression function of covariates. Based on such a formulation, we present an approach to constructing simultaneous confidence intervals for the cause-specific cumulative incidence function of patients with given risk factors. A melanoma data set is used for the purpose of illustration.