Well-differentiated thyroid carcinomas: p53 mutation status and microvessel density

BACKGROUND

Risk-stratification schemes exist for well-differentiated thyroid carcinoma and include prognostic factors such as age, sex, extent of tumor, size of tumor, and presence of metastasis. Controversy continues, however, over the aggressiveness of initial surgical intervention because of anecdotal experiences of poor clinical outcomes in low-risk patients. Our objective is to determine the prognostic significance of two biologic tumor markers, the p53 gene mutation and CD34 microvessel density (MVD) count, in well-differentiated tumors of thyroid gland.

METHODS

We selected 38 patients with well-differentiated thyroid carcinomas from the University of Illinois Tumor Registry. Patients had an average clinical follow-up of 10 years. Paraffin-embedded tumor specimens were available for all patients. Immunohistochemistry was performed to identify mutations of the p53 gene (Ab 1801) and to determine the MVD count (CD34).

RESULTS

There were significant increases in MVD counts within thyroid tumor tissue, when compared with surrounding, normal thyroid tissue. There was no significant correlation noted, however, between increased MVD and histology or recurrence rates. There was a trend toward higher MVD counts in tumor specimens of patients initially seen with metastatic lymphadenopathy. The incidence of p53 mutation expression was 28%, and there was no correlation between p53 status and histology, sex, recurrence rate, or survival.

CONCLUSIONS

This study supports the concept of tumor neovascularization but fails to correlate MVD with clinical behavior or pathologic features in well-differentiated thyroid carcinoma. Furthermore, we found that the p53 mutation status was not an independent prognosticator of tumor behavior in these lesions.

[Receptor-mediated endocytosis induced macrophage cytosolic acidification and exocytosis]

The effects of Con A, WGA, Zymosan A on macrophage cytosolic pH and outflow of lysosomal content through exocytosis were studied with SNAFL-calcein and FITC-Dextran on ACAS570. The results showed all three ligands could induce macrophage cytosolic acidification in about 10 min and kept at the same level hereafter; outflow of lysosomal fluorescent probe through exocytosis appeared in 15-20 min. In resting conditions, macrophage lysosomes mainly distributed in cell center; after stimulated for 15 min by three ligands, the number of lysosomes increased in membrane periphery, in 25-30 min lysosomes moved back toward cell center. We proposed that ligands induced lysosomal pH rises was a basic factor for outflow of lysosomal content through exocytosis, cytosolic acidification inhibited receptor-mediated endocytosis. Cytosolic acidification and outflow of lysosomal content through exocytosis were the results of cellular self-regulation and self-protection during receptor-mediated endocytosis.

Diastolic mitral regurgitation secondary to aortic regurgitation--a case report with emphasis on its mechanism

We report on a 68-year-old male case of mitral regurgitation secondary to aortic regurgitation diagnosed using transthoracic echocardiography. A different mechanism of mitral regurgitation secondary to aortic regurgitation is demonstrated in this report. Two-dimensional color Doppler echocardiography may be a useful tool for anatomic evaluation to define its mechanism.

Well-differentiated thyroid carcinomas: p53 mutation status and microvessel density

BACKGROUND

Risk-stratification schemes exist for well-differentiated thyroid carcinoma and include prognostic factors such as age, sex, extent of tumor, size of tumor, and presence of metastasis. Controversy continues, however, over the aggressiveness of initial surgical intervention because of anecdotal experiences of poor clinical outcomes in low-risk patients. Our objective is to determine the prognostic significance of two biologic tumor markers, the p53 gene mutation and CD34 microvessel density (MVD) count, in well-differentiated tumors of thyroid gland.

METHODS

We selected 38 patients with well-differentiated thyroid carcinomas from the University of Illinois Tumor Registry. Patients had an average clinical follow-up of 10 years. Paraffin-embedded tumor specimens were available for all patients. Immunohistochemistry was performed to identify mutations of the p53 gene (Ab 1801) and to determine the MVD count (CD34).

RESULTS

There were significant increases in MVD counts within thyroid tumor tissue, when compared with surrounding, normal thyroid tissue. There was no significant correlation noted, however, between increased MVD and histology or recurrence rates. There was a trend toward higher MVD counts in tumor specimens of patients initially seen with metastatic lymphadenopathy. The incidence of p53 mutation expression was 28%, and there was no correlation between p53 status and histology, sex, recurrence rate, or survival.

CONCLUSIONS

This study supports the concept of tumor neovascularization but fails to correlate MVD with clinical behavior or pathologic features in well-differentiated thyroid carcinoma. Furthermore, we found that the p53 mutation status was not an independent prognosticator of tumor behavior in these lesions.

Bcl-xL functions downstream of caspase-8 to inhibit Fas- and tumor necrosis factor receptor 1-induced apoptosis of MCF7 breast carcinoma cells

Stimulation of the Fas or tumor necrosis factor receptor 1 (TNFR1) cell surface receptors leads to the activation of the death effector protease, caspase-8, and subsequent apoptosis. In some cells, Bcl-xL overexpression can inhibit anti-Fas- and tumor necrosis factor (TNF)-alpha-induced apoptosis. To address the effect of Bcl-xL on caspase-8 processing, Fas- and TNFR1-mediated apoptosis were studied in the MCF7 breast carcinoma cell line stably transfected with human Fas cDNA (MCF7/F) or double transfected with Fas and human Bcl-xL cDNAs (MCF7/FB). Bcl-xL strongly inhibited apoptosis induced by either anti-Fas or TNF-alpha. In addition, Bcl-xL prevented the change in cytochrome c immunolocalization induced by anti-Fas or TNF-alpha treatment. Using antibodies that recognize the p20 and p10 subunits of active caspase-8, proteolytic processing of caspase-8 was detected in MCF7/F cells following anti-Fas or TNF-alpha, but not during UV-induced apoptosis. In MCF7/FB cells, caspase-8 was processed normally while processing of the downstream caspase-7 was markedly attenuated. Moreover, apoptosis induced by direct microinjection of recombinant, active caspase-8 was completely inhibited by Bcl-xL. These data demonstrate that Bcl-xL can exert an anti-apoptotic function in cells in which caspase-8 is activated. Thus, at least in some cells, caspase-8 signaling in response to Fas or TNFR1 stimulation is regulated by a Bcl-xL-inhibitable step.

[Effects of receptor-mediated endocytosis on macrophage membrane potential, cytosolic pH and lysosomal pH]

The effects of Con A, WGA, Zymosan A on membrane potential, cytosolic pH and lysosomal pH of cultured mouse macrophages were measured with fluorescence method. The results showed all the three kinds of ligands caused macrophage membrane potential hyperpolarization, cytosolic acidification and lysosomal alkalization, but reached their stabilized conditions at different times. The acidification of cytosl might inhibit further endocytosis. Alkalization of lysosomes was a basic factor for exocytosis of lysosomal contents. These receptor-mediated induced changes reflected cellular self-regulation and self-protection.

Diagnostic value of anti-hepatitis D virus (HDV) antibodies revisited: a study of total and IgM anti-HDV compared with detection of HDV-RNA by polymerase chain reaction

A high serum titre (> or = 1000 or > or = 5000) of total antibody to hepatitis D virus (anti-HDV) and positive for immunoglobulin (Ig)M anti-HDV have been used to represent HDV replication, while reverse transcription-polymerase chain reaction (RT-PCR) is currently the most sensitive assay for detecting HDV viraemia. The aim of the present study was to re-evaluate the correlation of total anti-HDV and IgM anti-HDV with HDV viraemia based on RT-PCR and to assess the clinical significance of these markers in acute and chronic HDV superinfection. Chronic HDV infection was defined as positive HDV-RNA by RT-PCR for more than 6 months, while total anti-HDV titre was defined by serial dilution. Of 178 hepatitis B virus (HBV) carrier patients studied, 119 cases had been anti-HDV positive for more than 6 months. Two-thirds (79/119) were positive for HDV viraemia by RT-PCR. Only half the chronic HDV viraemic patients had a high titre (> or = 1000) of total anti-HDV, and there was only moderate agreement (kappa = 0.41) between total anti-HDV titre/IgM anti-HDV and HDV-RNA and chronic HDV viraemia. Based on cross-sectional and longitudinal follow-up analyses, serum total anti-HDV titres > or = 100 appeared to be an excellent cut-off titre (kappa = 0.91) in differentiating chronic from acute HDV infection among viraemic patients. In summary, IgM and a high titre total of anti-HDV are not good markers of HDV viraemia, but an anti-HDV titre of > or = 100 appears to be an excellent marker for the differentiation of acute from chronic HDV superinfection.

Decreasing striatal 6-FDOPA uptake with increasing duration of cocaine withdrawal

It has been hypothesized that a decrease in dopaminergic presynaptic activity during abstinence or withdrawal is related to relapse in cocaine-dependent subjects (Dackis and Gold 1985; Markou and Koob 1991). This study measured striatal 6-fluorodopa (6-FDOPA) uptake, an index of dopaminergic presynaptic activity, using positron emission tomography (PET) in 11 drug-free cocaine addicts compared to eight normal subjects. Middle abstinence cocaine addicts (n = 5, off cocaine 11-30 days) had significantly lower striatal 6-FDOPA uptake compared to normal controls or early abstinence cocaine addicts (n = 6, off cocaine 1-10 days). The cocaine-dependent subjects (n = 11) showed a significant negative correlation between days off cocaine and striatal 6-FDOPA uptake. The results suggest that during abstinence from cocaine there is a delayed decrease in dopamine terminal activity in the striatum.

Differential effects of adenosine on antegrade and retrograde fast pathway conduction in atrioventricular nodal reentry

Although adenosine depresses antegrade atrioventricular (AV) nodal conduction, the effects of adenosine on antegrade and retrograde fast pathway conduction in AV nodal reentry have not been determined. In 17 patients (five men, 12 women, mean age 49 +/- 12 years) with common slow-fast AV nodal reentrant tachycardia, the antegrade slow pathway conduction was selectively and completely ablated by radiofrequency catheter ablation while the antegrade and retrograde fast pathway conduction remained intact. During high right atrial pacing at a mean pacing cycle length of 474 +/- 36 msec, adenosine was rapidly injected intravenously at an initial dose of 0.5 mg followed by stepwise increases of 0.5 mg or 1.0 mg given at 5-minute intervals until second-degree AV block developed. During right ventricular apical pacing at the same pacing cycle lengths (mean 474 +/- 36 msec) as those in the study of antegrade conduction, intravenous injection of incremental doses of adenosine was repeated until ventriculoatrial (VA) block occurred. The adenosine-induced prolongation of VA conduction was also determined in the presence of verapamil (loading dose 0.15 mg/kg, maintenance dose 0.005 mg/kg/min) in seven of 17 patients. The dose of adenosine required to produce AV block, the increase in the atrio-His interval by 50% and the maximal response were 3.4 +/- 1.4 mg, 1.8 +/- 0.6 mg, and 58% +/- 5%, respectively. On the other hand, the dose of adenosine required to produce VA block, the increase in the VA interval by 50%, and the maximal response were 8.2 +/- 2.9 mg, 3.4 +/- 0.6 mg, and 20% +/- 5%, respectively, in the control and 3.7 +/- 0.5 mg, 3.5 +/- 0.7 mg, and 23% +/- 5%, respectively, in the presence of verapamil. In conclusion, adenosine has a differential potency to depress AV and VA conduction in patients with AV nodal reentry, with greater potency for slowing antegrade fast than retrograde fast pathway conduction. Verapamil had an additive effect to adenosine on slowing retrograde VA conduction, which further supports the evidence that the retrograde fast pathway in part involves an AV nodal-like structure.

Decreasing hepatitis D virus infection in Taiwan: an analysis of contributory factors

Superinfection of hepatitis D virus (HDV) among hepatitis B virus (HBV) carriers is mainly through heterosexual contact in Taiwan. This study investigated the change of HDV endemicity and its associated contributory factors. Seventy-seven patients with acute HDV superinfection among 527 consecutive exacerbating hepatitis B surface antigen (HBsAg) carriers were identified over the past 12 years. The prevalence decreased significantly by each 3-year period from June 1983 to May 1995 (23.7, 15.5, 13.1 and 4.2%, respectively, P < 0.001). This trend was more significant in the hepatitis B e antigen (HBeAg)-negative group (P < 0.001) than in the HBeAg-positive group (P = 0.073). Subjects with a history of paid sex and prostitutes were also recruited for analysis both in 1989 and 1996. Although not statistically significant, there was a trend showing a decrease in the prevalence of serum antibody against HDV (anti-HDV) in each risk group: it was lower in 1996 among HBsAg-positive brothel-goers (10.3 vs 6.9%), licensed prostitutes (54.5 vs 50%) and unlicensed prostitutes (36.1 vs 30.8%). Accumulation of anti-HDV-positive subjects in risk groups may mask the actual decrease of new HDV-infected cases. The prevalence of the HBsAg carrier rate among all prostitutes has significantly decreased (18.3 vs 12.2%, P = 0.015). The efficacy of each preventive strategy was examined and mapped with the trend. It was concluded that active preventive measures directed against promiscuity and sexually transmitted disease and the promotion of disposable needles may have contributed to the decrease in HDV endemicity.

Reorganization of a novel vimentin-associated protein in 3T3-L1 cells during adipose conversion

We have found that the antibody A2, a marker for the capsule of steroidogenic lipid droplets, reacts with an intermediate filament-associated protein, P200, in 3T3-L1 preadipocytes. Supporting evidence came from the colocalization pattern of P200 with vimentin in double label experiments. The association of P200 with vimentin was further confirmed by its copurification with vimentin after high salt extraction and colocalization of these two proteins in high salt-extracted and vinblastine-treated cells. In preadipocytes this protein was distributed on the vimentin filament network. At the early stage of adipose conversion, this protein was found to encircle nascent lipid droplets ranging from 0.1 to 0.2 micron, accompanied with a decreased distribution on the vimentin filament system. This infers a possible translocation of P200 from the vimentin filaments to the droplet surface. Meanwhile, the vimentin filaments remained in a normal distribution in the cytoplasm and were apparently not associated with the nascent droplet. The association of vimentin filaments to droplet surfaces became prominent in lipid droplets larger than 0.2 micron, forming a typical vimentin cage. Immunogold staining also confirmed the translocation of P200 immunoreactivity from the droplet surface to the vimentin cage. The relocation of P200 from the cytoplasmic vimentin filaments to the droplet surface prior to the formation of the vimentin cage, as well as the reorganization of this protein in the vimentin cage, suggests a stabilizing role in the lipid droplet formation and an inducing function of this protein in the formation of the vimentin cage.

Predicting RNA H-type pseudoknots with the massively parallel genetic algorithm

MOTIVATION

Using the genetic algorithm (GA) for RNA folding on a massively parallel supercomputer, MasPar MP-2 with 16,384 processors, we successfully predicted the existence of H-type pseudoknots in several sequences.

RESULTS

The GA is applied to folding the tRNA-like 3' end of turnip yellow mosaic virus (TYMV) RNA sequence with 82 nucleotides, the 3' UTRs of satellite tobacco necrosis virus (STNV)-2 RNA sequence with 619 nucleotides and STNV-I RNA sequence with 622 nucleotides, and the bacteriophage T2, T4 and T6 gene 32 mRNA sequences with 946, 1340 and 946 nucleotides, respectively. The GA's results match the phylogenetically supported tertiary structures of these sequences.

Clinical study of cryoglobulinaemia in Chinese patients with chronic hepatitis C

Cryoglobulinaemia is the most common immunological disorders seen in patients with chronic hepatitis C virus (HCV) infection. We evaluated the incidence and clinical significance of cryoglobulinaemia in 122 Chinese patients with chronic hepatitis C. The pathogenic roles of HCV genotypes and viraemia in this phenomenon were also evaluated. Fifty-four (44%) of the 122 patients with chronic hepatitis C had cryoglobulinaemia. Eleven (20%) of the patients with cryoglobulinaemia had symptoms and signs of cutaneous vasculitis, arthralgia, neuropathy and renal involvement. The patients with cryoglobulinaemia were predominantly female and had a significantly higher mean serum level of rheumatoid factor and a lower mean serum C4 level compared with patients without cryoglobulinaemia (50 vs 29%, 23 vs 15 IU/mL, 25 vs 31 mg/dL, respectively, P < 0.05). The mean serum HCV RNA level, HCV genotype, the presence of serum auto-antibodies, and the rate of cirrhosis were not significantly different between the two groups. Univariate logistic regression analysis showed female serum levels of alanine aminotransferase (> 90 U/L), rheumatoid factor (> 15 IU/mL), C3c (< 100 mg/dL) and C4 (< 20 mg/dL) to be significant predictors of cryoglobulinaemia in chronic hepatitis C patients. However, multivariate analysis showed only serum C4 levels (< 20 mg/dL) as a significantly independent predictor. We concluded that 44% of Chinese patients with chronic hepatitis C had cryoglobulinaemia. Serum C4 levels were significantly lower in chronic hepatitis C patients with cryoglobulinaemia and the serum C4 level was the only clinical independent predictor associated with this phenomenon. Hepatitis C virus genotype and serum viral load were not clinical independent predictors.

Prevalence and risk factor analysis of GBV-C/HGV infection in prostitutes

GB virus-C (GBV-C) and Hepatitis G virus (HGV) are variants of a recently cloned virus transmitted parenterally. It is unclear if sexual contact also transmits this virus. In this study, we detected serum GBV-C/HGV RNA in 140 prostitutes by reverse transcription polymerase chain reaction (RT-PCR) using different primers. Thirty (21%) were found with GBV-C RNA by nested PCR although only 22 (73%) had HGV RNA by single round RT-PCR. Both assays had a nearly perfect agreement (kappa value, 0.812). The prevalence of GBV-C RNA in prostitutes was significantly higher than the control group (30/140 vs. 2/40, P < 0.02). Multivariate analysis revealed that a frequency of paid sex more than 120 times per month was the only factor significantly associated with positive GBV-C RNA in prostitutes (P < 0.003). In summary, prostitutes are a high risk group and reservoir of GBV-C/HGV infection due to high frequency of paid-sex.

Clinicopathological comparison of resectable hepatocellular carcinoma between the young and the elderly patients

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common cancers in many parts of the world. In Taiwan it is the leading cause of death in male cancer patients. The peak age of onset of HCC varies according to geographic barriers, which indicates different hepatocarcinogenesis among different age groups. This study aims to evaluate whether there exists significantly different clinicopathological features between young and elderly HCC patients.

METHODS

During a six-year period, a total of 248 patients with HCC underwent liver curative resection at Veterans General Hospital-Taipei, Taiwan. Among them, 22 patients were younger than 40 years of age, and 43 patients were older than 70 years of age. Important clinicopathological characteristics of the patients (including sex, family history of HCC, smoking habits and alcohol consumption patterns, hepatitis B or C infection, indocyanine-green retention rate at 15 minutes (ICGR-15), serum alpha-fetoprotein value, tumor size, tumor number, tumor venous invasion, capsular formation, tumor staging, cirrhosis, and tumor DNA ploidy) and postresectional prognosis were compared between young and elderly HCC patients.

RESULTS

The frequency of presence of family history (22.7% versus 4.7%), hepatitis B surface antigen carrier rate (81.8% versus 48.8%), and patients with large-sized tumors (31.8% versus 7.0%) were significantly higher in young patients than in elderly patients. The male:female ratio (4.5:1 versus 42:1), degree of liver damage (reflected by the ICGR-15 value, 5.6 +/- 5.0% versus 13.1 +/- 8.8%) and the incidences of liver cirrhosis (18.2% versus 48.8%) were significantly lower in young patients than in elderly patients. However, there were no significant differences in postresectional survival rates between these two groups.

CONCLUSIONS

There are age-related differences in clinicopathological characteristics of HCC patients. Accordingly, different mechanisms of hepatocarcinogenesis may exist between young and elderly HCC patients.

Two proximal activating protein-1-binding sites are sufficient to stimulate transcription of the ovine follicle-stimulating hormone-beta gene

FSH is an important regulator of mammalian gametogenesis and the female reproductive cycle. Although little is known about the transcriptional regulation of the beta-subunit (the rate-limiting subunit of FSH synthesis), sequence analysis of the ovine FSHbeta promoter has revealed a number of potential activating protein-1 (AP-1; Jun/Fos)-binding sites. To determine whether the gene encoding the beta-subunit of ovine FSH (oFSHbeta) is responsive to AP-1 transcriptional complexes, chimeric constructs containing deleted portions of the oFSHbeta promoter fused to a luciferase reporter were transiently transfected along with c-Jun and c-Fos expression constructs into JAR cells. Analysis of these deletion constructs revealed that the proximal promoter of oFSHbeta is highly stimulated by c-Jun and c-Fos proteins (typically 20-fold with a reporter construct containing oFSHbeta sequences from -215 to +759 bp). This stimulation was lost when a similar construct containing sequences from -84 to +759 bp was tested. Transcriptional start site analysis using reverse transcription-PCR verified that the transcriptional initiation of the -215-bp deletion construct, with or without cotransfected c-Jun/c-Fos, was the same as that observed in vivo. Computer analysis of oFSHbeta sequences from -215 to +1 bp identified four putative AP-1-like elements, located at -155, -120, -83, and -10 bp. Gel retardation experiments using oligonucleotides corresponding to the four putative AP-1-like sites revealed that only -120 and -83 sites in oFSHbeta bound AP-1 proteins in vitro. Site-directed mutagenesis of the -120 and -83 sites showed that each element was required for stimulation by c-Jun and c-Fos proteins as well as 12-O-tetradecanoyl phorbol-13-acetate in transient transfection assays. Finally, immunocytochemical dual labeling was used to show that more than 75% of all FSHbeta-containing cells in ovine pituitary sections from cycling ewes contained nuclear c-Jun, JunB, JunD, and Fos proteins. These data, taken together, show that oFSHbeta transcription can be stimulated by c-Jun and c-Fos proteins via two functionally linked AP-1-like sites in the oFSHbeta proximal promoter and that these sites are likely to be important regulators of FSH production in vivo.

Specific inhibition of delta antigen by in vitro system by antisense oligodeoxynucleotide: implications for translation mechanism and treatment

Synthetic antisense oligodeoxynucleotides (ODNs) and a system containing transcription and translation coupled rabbit reticulocyte lysate were used to develop a new model modulating the synthesis of small delta antigen which, in turn, inhibits the replication of HDV (hepatitis D virus). The ODN was stable for at least 50 min in this system at 37 degrees C. Unmodified 15-mer antisense D3 and D4, complementary to translation initiation region and coding region, respectively, inhibit the synthesis of small delta antigen by 95% at a concentration of 5 microM, whereas antisenses complementary to 5' noncoding region, stop codon region and polyadenylation site were less effective. This system also showed a dose-dependent inhibitory effect of antisense D3 on the production of the target protein. However, the synthesis of E6 protein, an internal control, was not affected. These observations imply that this in vitro system is convenient for rapid screening of effective antisense compounds and offers a promising perspective for the investigation of translation mechanisms and for the inhibition of HDV replication by antisense strategy.

D2 dopamine receptor polymorphism and brain regional glucose metabolism

Positron emission tomography (PET) studies have shown decreased glucose metabolism in brain regions of detoxified alcoholics and cocaine abusers. However, it is not clear whether this decrease is due to chronic drug abuse or a pre-existing condition. Molecular genetic studies have found an association of the D2 dopamine receptor (DRD2) A1 allele with alcoholism and drug abuse. Moreover, reduced central dopaminergic function has been suggested in subjects who carry the A1 allele (A1+) compared with those who do not (A1-). In the present study, using 18F-deoxyglucose, regional glucose metabolism was determined in healthy nonalcohol/nondrug-abusing subjects with the A1+ or A1- allele. The mean relative glucose metabolic rate (GMR) was significantly lower in the A1+ than the A1- group in many brain regions, including the putamen, nucleus accumbens, frontal and temporal gyri and medial prefrontal, occipito-temporal and orbital cortices. Decreased relative GMR in the A1+ group was also found in Broca's area, anterior insula, hippocampus, and substantia nigra. A few brain areas, however, showed increased relative GMR in the A1+ group. Since polymorphism of the DRD2 gene is commonly observed in humans, the importance of differentiating A1+ and A1- alleles subjects in PET studies is suggested.

Hepatitis B infection and changes in interferon-alpha and -gamma production in patients with systemic lupus erythematosus in Taiwan

According to previous reports, the prevalence of hepatitis B virus (HBV) infection in patients with systemic lupus erythematosus (SLE) is varied. There has been no report on Taiwan, a hyperendemic area for HBV infection. Furthermore, impaired production of interferon (IFN) in peripheral blood mononuclear cells (PBMC) has been reported to be potentially pathogenic to both chronic HBV infection and SLE. However, the production of IFN in patients with both diseases coexisting is unknown. The aims of this study were to evaluate the prevalence of HBV infection in lupus patients in Taiwan and to measure the production of IFN in patients with both diseases coexisting. One hundred and seventy-three consecutive lupus patients and a control group of 692 age- and sex-matched healthy subjects were included for evaluation of the prevalence of HBsAg. Four groups of subjects (patients with SLE and HbsAg, SLE, chronic hepatitis B and normal controls) were selected for evaluation of the in vitro production of IFN-alpha and -gamma. Six (3.5%) of the 173 SLE patients were positive for HBsAg, which was significantly lower than that of controls (14.7%; P < 0.0001). Patients with coexistent SLE and chronic HBV infection had less lupus activity, including less proteinuria (P = 0.02) and a lower serum titre of anti-double stranded DNA antibodies (anti-dsDNA; P = 0.04), than HBsAg-negative lupus patients. The in vitro production of IFN-alpha in patients with chronic hepatitis B was significantly lower than in those patients with SLE or in the normal control group (P < 0.01). The yields of IFN-alpha and -gamma in patients with coexistent SLE and chronic HBV infection were significantly different from those patients with SLE alone (P < 0.05), but close to those of patients with chronic HBV infection. In conclusion, the prevalence of HBsAg carriers is significantly lower in lupus patients in Taiwan. Patients with coexistent SLE and chronic HBV infection had less lupus activity. Interferon-alpha and -gamma may play a role in the above phenomenon.

The role of hepatitis G virus infection in patients with acute posttransfusion hepatitis in Taiwan

BACKGROUND & AIMS

Hepatitis G virus (HGV) has been recently identified as a new transfusion-transmissible agent. This study was performed to evaluate the role of HGV infection in patients with acute posttransfusion hepatitis in Taiwan.

METHODS

Sera from 63 patients with acute posttransfusion hepatitis and 61 patients with normal serum aminotransferase levels after transfusion were tested for HGV RNA by reverse-transcription polymerase chain reaction.

RESULTS

Six of the 63 patients (9.5%) with acute posttransfusion hepatitis were positive for HGV RNA in pretransfusion sera; 4 were superinfected with hepatitis C virus (HCV) after transfusion and 3 developed chronic hepatitis. Seven (12.3%) of the remaining 57 patients had acute posttransfusion HGV infection; 5 were coinfected with HCV and 2 infected with HGV alone. None with acute HGV infection alone developed chronic hepatitis, whereas 4 of 5 patients (80%) with acute HGV and HCV coinfection developed chronic hepatitis. The clinical course of acute HGV and HCV coinfection was similar to that of acute HCV infection alone. Four of 61 subjects (6.6%) with normal serum aminotransferase levels after transfusion were subclinically infected with HGV.

CONCLUSIONS

HGV infection accounted for 12.3% of acute posttransfusion hepatitis in Taiwan before anti-HCV screening of blood donors. The clinical course of acute posttransfusion HGV infection alone was relatively benign.

A nurse rostering system using constraint programming and redundant modeling

This paper describes the design and implementation of a constraint-based nurse rostering system using a redundant modeling approach. Nurse rostering is defined as the process of generating timetables for specifying the work shifts of nurses over a given period of time. This process is difficult because the human roster planner has to ensure that every rostering decision made complies with a mixture of hard hospital rules and soft nurse preference rules. Moreover, some nurse shift pre-assignments often break the regularity of wanted (or unwanted) shifts and reduce the choices for other unfilled slots. Soft constraints amount to disjunction, which can be modeled as choices in the search space. This approach, although straightforward, incurs overhead in the search of solution. To reduce search time, we propose redundant modeling, an effective way to increase constraint propagation through cooperations among different models for the same problem. Our problem domain involves around 25 to 28 nurses and 11 shift types. Experiments and pilot testing of the system confirm the effectiveness and efficiency of our method.

Experimental study of double-lumen, two-stage endotracheal tube during conventional mechanical ventilation in rabbits

OBJECTIVE

To evaluate the effects of a double-lumen, two-stage endotracheal tube on gas exchanges (ventilatory efficiency) during conventional mechanical ventilation, using a ventilator in rabbits.

DESIGN

Prospective, randomized, crossover laboratory animal trial.

SETTING

Research laboratory in the Beijing Children's Hospital.

SUBJECTS

Five adult New Zealand rabbits, weighing 3.2 to 3.7 kg.

INTERVENTIONS

A new type of endotracheal tube-the double-lumen two-stage endotracheal tube-was designed and tested for ventilation efficiency in rabbits with normal and injured lungs. The new tube (size 3.0 mm) was made out of two Portex endotracheal tubes (size 3.0 mm) by adhering two vertical cross-sections at the distal end of the two tubes. The new tube and a conventional endotracheal tube of the same size (inner diameter 3.0 mm) were randomly used in pressure control ventilation. Each trial was maintained for 30 mins.

MEASUREMENTS AND MAIN RESULTS

Effects from the two endotracheal tubes on pulmonary mechanics, hemodynamics, and gas exchange were observed. We measured peak inspiratory pressure, positive end-expiratory pressure (PEEP), intrinsic PEEP, mean airway pressure, and arterial blood and mixed expired gas variables (Pao2, Paco2, pH, and mixed expired gas Pco2). The new endotracheal tube acutely increased CO2 elimination in all animals with normal and injured lungs. Paco2 decreased from 46 +/- 4 to 36 +/- 5 torr (6.1 +/- 0.5 to 4.8 +/- 0.7 kPa; p < .01) in normal lungs and from 48 +/- 5 to 36 +/- 5 (6.4 +/- 0.7 to 4.8 +/- 0.7 kPa; p < .01). Meanwhile, tidal volume fraction decreased from 0.48 +/- 0.07 to 0.35 +/- 0.05 (p < .01) and from 0.56 +/- 0.07 to 0.40 +/- 0.07 (p < .01) in normal and injured lungs, respectively. Intrinsic PEEP of the new tube slightly increased, but there were no significant differences in comparison with the conventional tube.

CONCLUSION

Compared with the conventional endotracheal tube, the new double-lumen, two-stage endotracheal tube reduced Paco2 by decreasing anatomical deadspace in rabbits with normal and injured lungs under pressure control ventilation, thus enhancing ventilatory efficiency and reducing ventilator-induced injury.

Increased dopamine activity associated with stuttering

Position emission tomography using 6-FDOPA as a marker of presynaptic dopaminergic activity was used to investigate the role of the dopamine system in stuttering. Three patients with moderate to severe developmental stuttering were compared with six normal controls. Stuttering subjects showed significantly higher 6-FDOPA uptake than normal controls in medial prefrontal cortex, deep orbital cortex, insular cortex, extended amygdala, auditory cortex and caudate tail. Elevated 6-FDOPA uptake in ventral limbic cortical and subcortical regions is compatible with the hypothesis that stuttering is associated with an overactive presynaptic dopamine system in brain regions that modulate verbalization.

Hepatocellular carcinoma in the caudate lobe: early diagnosis and active treatment may result in long-term survival

Hepatocellular carcinoma (HCC) in the caudate lobe is rare and the prognosis of patients with HCC in the caudate lobe has been reported to be poor. Resection for HCC in the caudate lobe has carried a higher rate of surgical risk and early recurrence. The effect of transcatheter arterial embolization (TAE) in treating HCC in the caudate lobe remains unknown. With the wide application of modern diagnostic modalities, we can now detect HCC at an earlier stage for active treatment (surgery or TAE). The aim of the present study was to analyse the effect of different treatments for HCC in the caudate lobe. From 1985 to 1994, 15 patients with HCC in the caudate lobe were retrospectively studied. Another 264 consecutive patients with newly diagnosed HCC treated by TAE were selected as the control group. Two patients underwent surgical resection and survived well without recurrence after 43 and 136 months, respectively. Ten patients underwent TAE and their survival rate was similar to that of the 264 consecutively TAE-treated controls with HCC not in the caudate lobe (P = 0.19). The 1, 3 and 5 year survival rates for TAE-treated patients in the caudate lobe were 67.7, 31.1 and 12.6%, respectively, while in controls these figures were 53.0, 18.4 and 9.1%, respectively. Two of the three patients receiving supportive treatment died within 1 month after diagnosis. Those patients having a smaller solitary tumour without intrahepatic metastasis tended to survive longer. In conclusion, HCC in the caudate lobe does not always indicate a poor prognosis so long as early detection and active treatment (surgery or TAE) are available. Transcatheter arterial embolization may act as an alternative treatment modality for patients with HCC in the caudate lobe.

Rationally designed inhibitors of inosine monophosphate dehydrogenase

Functionalized 2-alkyl derivatives of inosinic acid have been synthesized to serve as reversible as well as irreversible inhibitors of the human type II enzyme inosine monophosphate dehydrogenase. These compounds were designed to react with Cys-331 of the enzyme to form covalent bonds so as to interfere with the normal enzyme mechanism which involves attack of Cys-331 at C-2 of the substrate. Mass spectrometric analysis of the reaction products after enzymatic degradation confirmed the appropriateness of the inhibitor design.