T-cell factor-4 and MHC upregulation in pigs receiving a live attenuated classical swine fever virus (CSFV) vaccine strain with interferon-gamma adjuvant

The effect of co-administration of interferon (IFN)-γ in pigs undergoing vaccination with an attenuated strain (LPC) of classical swine fever virus (CSFV) was investigated. Unvaccinated pigs demonstrated pyrexia and died 7-9 days after challenge with virulent CSFV. Pigs receiving the attenuated vaccine remained healthy after virus challenge, except for mild, transient pyrexia, whereas pigs receiving IFN-γ simultaneously with the vaccine demonstrated normal body temperatures after virus challenge. Examination by nested RT-PCR revealed greater viral load in the spleens of the pigs vaccinated with the attenuated CSFV, compared with those that had additionally received IFN-γ. Expression of major histocompatibility complex (MHC) class I and MHC class II molecules was upregulated in the spleens of the IFN-γ treated vaccinated pigs, demonstrated by immunohistochemistry. Based on Western blot analysis, anti-CSFV IgG2 antibodies were elevated in vaccinated pigs by co-administration of IFN-γ (IFN-γ(Hi): P < 0.01; IFN-γ(Lo): P <0.05). By employing the suppression subtractive hybridization technique, RT-PCR, in situ hybridization, and immunohistochemistry, T-cell factor-4 (Tcf-4) mRNA and protein expression were found to be upregulated in the spleens of vaccinated pigs that had received IFN-γ. This study suggests involvement of Tcf-4 in IFN-γ-mediated immune regulation following CSFV vaccination.

Reappraisal of the importance of mutations in the NS5A-PKR-binding domain of hepatitis C-1b virus in the era of optimally individualized therapy

Past studies have reported that mutations in the protein kinase R-binding domain (PKRBD) sequences of hepatitis C virus (HCV) NS5A proteins are correlated with response to fixed-duration interferon (IFN)-based therapy in patients infected with HCV-1b. In this study, we investigated whether the substitutions in PKRBD, including the IFN sensitivity-determining region (ISDR) and 26 additional downstream amino acids from ISDR, will have effects upon patients infected with chronic HCV-1b in the era of individualized therapy with peginterferon and ribavirin. Thirty-seven patients were treated with optimally tailored therapy guided by baseline viral load combined with rapid and early virological responses while 23 patients were treated without guidance and/or assigned suboptimal treatment duration. The amino acid sequences of the PKRBD were determined by PCR and sequencing. The overall sustained virological response (SVR) rate of patients who received optimally individualized therapy was 78.4%, which was better than the SVR rate of patients who received suboptimal therapy (47.8%, P = 0.015). Multivariate analysis showed that optimally individualized therapy (P = 0.019) and 80/80/80 adherence (P = 0.006) were independent favourable predictors of SVR in the entire cohort. Further sub-analysis of the predictive factors of SVR in patients treated with optimally individualized therapy showed that mutations in the 26-amino acid downstream from the ISDR (P = 0.024) were the only independent predictor of SVR. We concluded that mutations in 26-amino acid downstream portion from the ISDR remained a prognosticator of SVR in the era of optimally tailored therapy.

Use of a recombinant protein containing major epitopes of hnRNP G to detect anti-hnRNP G antibodies in dogs with systemic lupus erythematosus

The objective of this study was to express major epitopes of heterogeneous nuclear ribonucleoprotein G (hnRNP G) for detecting anti-hnRNP G antibodies in dogs with systemic lupus erythematosus (SLE). HnRNP G cDNA clone was isolated from HEp-2 cells, and a DNA fragment encoding immunodominant region (residues 189-272) of hnRNP G (hnRNP Gi) was subcloned into pET32 vector to construct a prokaryotic expression plasmid named pEThnRNPGi. After induction, Escherichia coli carrying pEThnRNPGi expressed a recombinant protein of 28 kDa, comprising recombinant hnRNP Gi and fusion tag. Purified recombinant hnRNP Gi protein was further analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and its identity was confirmed. Western blot analysis showed that recombinant hnRNP Gi was specifically recognized by anti-hnRNP G positive sera of SLE dogs, and not by negative control sera. In conclusion, recombinant hnRNP Gi protein expressed in this study may serve as a useful reagent to assist in the immunological diagnosis of canine SLE.

CXC chemokine receptor CXCR4 expression enhances tumorigenesis and angiogenesis of basal cell carcinoma

BACKGROUND

Chemokines and their receptors, well known for their ability to attract leucocytes, also play important roles for tumour progression.

OBJECTIVES

To investigate the possible involvement of chemokine receptors in the pathogenesis of cutaneous basal cell carcinoma (BCC).

METHODS

We performed an expression analysis of chemokine receptors using a well-characterized human BCC cell line. Upon the finding of CXCR4 expression by BCC, retroviral transduction of BCC cells with the CXCR4 gene was employed to address its functional significance for BCC in vitro and in vivo.

RESULTS

We found expression of the CXC chemokine receptor CXCR4 by a human cell line and a subset of tissue samples from BCC, especially in noduloulcerative and sclerosing types. Following treatment with CXCL12, the ligand for CXCR4, CXCR4-transduced BCC cells (CXCR4-BCC) showed increased proliferation under low serum concentration and resistance to apoptosis induced by ultraviolet B irradiation in vitro. Conditioned media from CXCR4-BCC preincubated with CXCL12 enhanced tubule formation of human endothelial cells in vitro. These responses of CXCR4-BCC were negated by cotreatment with either neutralizing antibodies or specific blocking peptides for CXCR4 in vitro. Moreover, xenograft tumour transplants produced by injection of CXCR4-BCC yielded significant tumour progression in nude mice, whereas additional serial injections of CXCR4-blocking peptides resulted in tumour regression.

CONCLUSIONS

CXCR4 expression may play a critical role in tumour progression and angiogenesis of certain subtypes of BCC with more aggressive nature, and functional blockade of CXCR4 could be a potential therapeutic strategy for these tumours.

Fatal pulmonary fibrosis associated with BCNU: the relative role of platelet-derived growth factor-B, insulin-like growth factor I, transforming growth factor-β1 and cyclooxygenase-2

Pulmonary fibrosis is a severe complication associated with bis-chloronitrosourea (BCNU) therapy. However, the pathogenetic mechanism has never been well investigated. We report here a 26-year-old female with diffuse large B-cell lymphoma who died of severe pulmonary fibrosis 81 days after the administration of high-dose BCNU (600 mg/m2). Thoracoscopic wedge resection of left upper lung performed 10 days before patient's death showed severe pulmonary fibrosis with prominent hyperplasia of alveolar macrophages and type II pneumocytes. We further used immunohistochemistry (IHC) to examine the relative role of platelet-derived growth factor-B (PDGF-B), insulin-like growth factor I (IGF-I), transforming growth factor-beta1 (TGF-beta1) and cyclooxygenase-2 (COX-2) in the pathogenesis of BCNU-related pulmonary fibrosis. Strong expressions of PDGF-B and IGF-1 on alveolar macrophages and type II pneumocytes were clearly demonstrated, but in contrast, the expressions of TGF-beta1 and COX-2 were almost undetectable. In conclusion, pulmonary fibrosis can develop early and progress rapidly after the administration of high-dose BCNU. The markedly increased expression of fibrogenic factors PDGF-B and IGF-1 on hyperplastic alveolar macrophages and hyperplastic type II pneumocytes may play an important role in the fibrogenesis of this disease. These novel findings may offer specific therapeutic targets in the treatment of BCNU-associated pulmonary fibrosis.

Prognostic significance of nm23-H1 expression in oral squamous cell carcinoma

Recent studies indicated nm23-H1 played a role in cancer progression. Therefore, we investigated clinical significance of nm23-H1 expression in oral squamous cell carcinoma (OSCC). In total, 86 OSCC specimens were immunohistochemically stained with nm23-H1-specific monoclonal antibodies. Immunohistochemical staining of nm23-H1 was confirmed by immunoblotting. The relations between nm23-H1 expression and clinicopathologic variables were evaluated by chi(2) analysis. As increased size of primary tumour could escalate metastatic potential and the data of patients at the late T stage might confound statistical analyses, we thus paid special attention to 54 patients at the early T stage of OSCC. Statistical difference of survival was compared by a log-rank test. Immunohistochemically, nm23-H1 expression was detected in 48.8% (42 out of 86) of tumorous specimens. It positively correlated with larger primary tumour size (P=0.03) and inversely with cigarette-smoking habit (P=0.042). In patients at the early T stage, decreased nm23 expression was associated with increased incidence of lymph node metastasis (P=0.004) and indicated poor survival (P=0.014). Tumour nm23-H1 expression is a prognostic factor for predicting better survival in OSCC patients at the early T stage, which may reflect antimetastatic potential of nm23. Therefore, modulation of nm23-H1 expression in cancer cells can provide a novel possibility of improving therapeutic strategy at this stage. In addition, our results further indicated cigarette smoking could aggravate the extent of nm23-H1 expression and possibly disease progression of OSCC patients.

Cyclooxygenase-2 in human non-small cell lung cancer

AIM

Recent studies report that the expression of cyclooxygenase (COX) in non-small cell lung cancer (NSCLC) is increased, especially in adenocarcinoma. Platelet activating factor (PAF), n-sodium butyrate (n-BT), and phorbol myristate acetate (PMA) are important mediators of the inflammatory process.

METHOD

Expression of COX-2 in 67 stage 1 NSCLC paraffin-embedded tumor samples was determined by immunohistochemistry (IHC). Four NSCL cell lines were incubated and stimulated by PAF, n-BT and PMA for 48 h. Expression of COX-2 was determined by IHC, immunoblotting, and reverse transcription-polymerase chain reaction (RT-PCR).

RESULT

IHC showed increasing immunoreactivity in 35 of 67 (52%) in stage I NSCLC, 31 of 53 (59%) in adenocarcinoma and 13 of 15 (87%) in bronchoalveolar cell carcinoma, but only 2 of 12 (17%) in epidermoid carcinoma. The COX-2 expression in NSCLC cells was 75% (3/4) and the COX-1 expression in NSCLC cells was 100% (4/4). After stimulation with PMA, n-BT, PAF and n-BT + PAF, the COX-2 expression in NSCLC cells was significantly increased in all cell lines.

CONCLUSIONS

The expression of COX-2 in NSCLC cells is high and was up-regulated by PMA, n-BT and PAF. We consider that COX-2 inhibitors will play an important role in the therapy of NSCLC.

Increased expression of dihydrodiol dehydrogenase induces resistance to cisplatin in human ovarian carcinoma cells

We employed cDNA microarrays to identify the differentially expressed genes in a cisplatin-sensitive parental (2008) human ovarian carcinoma cell line and its cisplatin-resistant variant (2008/C13*). Differential expression of five genes was found in the 2008/C13* cells, a result confirmed by semi-quantitative reverse transcription-PCR. The five genes were identified as fibroblast muscle-type tropomyosin and skeletal muscle-type tropomyosin, dihydrodiol dehydrogenase, apolipoprotein J and glucose-6-phosphate dehydrogenase variant-A. Treatment of the 2008 cells with cisplatin (at its IC(50) concentration of 2 microm) induced expression of these genes, as determined by semi-quantitative reverse transcription-PCR analysis using gene-specific primers. In contrast, treatment of the drug-resistant 2008/C13* cells with cisplatin (at its IC(50) concentration of 20 microm) did not lead to the induction of any of the aforementioned genes. Most importantly, constitutive overexpression of dihydrodiol dehydrogenase (but not the other genes) in the 2008 cells led to induction of cisplatin resistance, clearly indicating its role in the development of the resistance phenotype in the 2008/C13* cells. The development of cisplatin resistance in the transfected cells was associated with an increase in the dihydrodiol dehydrogenase enzyme activity. Although at present it is not clear how dihydrodiol dehydrogenase is involved in cisplatin resistance, the identification of this gene as a causal factor suggests the existence of a hitherto undefined pathway resulting in cisplatin resistance.

Effects of platelet activating factor, butyrate and interleukin-6 on cyclooxygenase-2 expression in human esophageal cancer cells

BACKGROUND

Epidemiological studies have indicated that non-steroidal anti-inflammatory drugs (NSAIDs) can reduce the risk of esophageal squamous cell carcinoma (ESCC) by taking cyclooxygenase (COX) as the target enzyme. The pathophysiological regulation of COX-2 may play a role in carcinogenesis and in disease progression of esophageal carcinoma.

METHODS

59 ESCC samples were used to assess COX-2 expression in the tumor cells and four ESCC cell lines to investigate the effects of phorbol myristate acetate (PMA), platelet activating factor (PAF), n-sodium butyrate (n-BT) and interleukin-6 (IL-6) on the expression of COX-2. Expression of COX-2 was determined by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). Production of PGE2 was measured by a competitive enzyme immunoassay (CEIA).

RESULTS

COX-2 expression was detected in 54.2% (32/59) of the pathological sections by IHC. COX-2 expression in ESCC cells was significantly increased following treatment with PAF and n-BT. Increased production of PGE2 was detected in the culture media, and the secreted PGE2 in the culture media was proportional to the increased COX-2 expression. The addition of IL-6 could also enhance COX-2 expression in ESCC cells. While NSAIDs could inhibit enzymatic activity of COX-2, they did not inhibit COX-2 gene expression in ESCC cells. PKC inhibitor, however, could abrogate PMA-induced COX-2 gene expression, but it did not block IL-6-induced COX-2 expression.

CONCLUSIONS

Our data suggest that COX-2 expression in ESCC cells could be upregulated by PMA, PAF, n-BT and IL-6. Nonetheless, IL-6-induced COX-2 expression could be independent of PKC activation.

Effect of platelet activating factor and butyrate on the expression of interleukin-2 receptor alpha in nasopharyngeal carcinoma cells

Serum level of soluble interleukin-2 receptor alpha (sIL-2Ralpha) has been shown to correlate with disease progression and prognosis of cancer patients. However, the available information about the source and the pathophysiological regulation of IL-2Ralpha in cancer cells is limited. This study addressed the questions of prognostic value and the source of sIL-2Ralpha in patients with nasopharyngeal carcinoma (NPC). Biological regulation of IL-2Ralpha was characterized in NPC cell lines. Serum sIL-2Ralpha levels of 113 NPC patients were measured by enzyme-linked immunosorbent assay (ELISA). Levels of sIL-2Ralpha in NPC patients were significantly higher than that in the healthy controls, and sIL-2Ralpha levels were correlated with disease progression and patient survival. IL-2Ralpha was identified in cancer cells by immunocytochemistry. In vitro, IL-2Ralpha expression was markedly increased following treatment with platelet activating factor and/or n-sodium butyrate. Increased secretion of IL-2Ralpha was also detected in the culture media. The secreted IL-2Ralpha could functionally bind IL-2. These results indicate that elevated sIL-2Ralpha was often detected in patients with advanced NPC. The elevated sIL-2Ralpha could be shed from NPC cells by a yet to be determined mechanism and IL-2Ralpha expression in NPC cells could be upregulated by platelet activating factor and butyrate.

Detection of cytomegalovirus infection in a patient with febrile ulceronecrotic Mucha-Habermann's disease

BACKGROUND

Febrile ulceronecrotic Mucha-Habermann's disease (FUMHD) is a severe and very rare variant of pityriasis lichenoides et varilioformis acuta, which is characterized by large coalescing, and ulceronecrotic maculopapules or plaques. Morphological changes of the skin accompanied by persistent high fever and several constitutional symptoms have suggested virus infection in patients with FUMHD. However, the available information of viral origin is limited. In this study we investigated the relationship of cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 8 (HHV8), type I human T-cell lymphotropic virus (HTLV-I), and parvovirus B19 (PVB19) with FUMHD in a Taiwanese patient.

METHODS

The existence of CMV, EBV, HHV8, HTLV-I, and PVB19 was determined by polymerase chain reaction (PCR). The presence of CMV in the endothelial cells was characterized by in situ hybridization (ISH) and immunohistochemistry (IHC).

RESULTS

Serologic immunoglobulin to CMV and IHC identification of CMV late gene in the biopsy specimen indicated that the patient was infected with CMV. Detection of CMV was confirmed by PCR and ISH.

CONCLUSIONS

These results indicate that FUMHD is associated with dermal CMV manifestation. Nonetheless, the induction mechanism of FUMHD with CMV infection has yet to be determined.

Repeated intestinal perforation caused by an incomplete form of Behçet's syndrome

Behçet's disease, as initially described, is a triad of recurrent oral and genital ulcers and relapsing uveitis. The incomplete form, in which there is no ocular involvement, has been described in Japan and Korea, but this is not commonly recognized in the southern Chinese. We reported herein a rare case of repeated intestinal perforations caused by an incomplete form of Behçet's syndrome in a southern Chinese man.

Phase II trial of systemic recombinant interleukin-2 in the treatment of refractory nasopharyngeal carcinoma

BACKGROUND

Interleukin-2 (IL-2) is a cytokine produced by activated T cells, which has shown powerful immunostimulatory and antineoplastic properties. Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated cancer with abundant lymphocyte infiltration histologically. The activity of IL-2 in the treatment of NPC patients is currently unknown. A phase II study was, therefore, initiated to evaluate the efficacy, toxicity and immunological consequences of intravenous bolus IL-2 in patients with recurrent/metastatic NPC.

METHODS

Between November 1996 and April 1997, 14 patients with recurrent/metastatic NPC were entered into the study. Recombinant IL-2 (Proleukin, Chiron) was injected by intravenous bolus every 8 h at 72,000 IU/kg for a maximum of 15 doses. After 7 days, patients were retreated with a second identical cycle of therapy. Those patients who were stable or responding to treatment 5-6 weeks later went on to receive another course (two cycles) of therapy. All patients received prophylactic antibiotics and antipyretic medicine. Response and toxicities were evaluated. Serial plasma level of TNF-alpha, IL-6, soluble IL-2 receptor, IL-10 and soluble CD8 were determined.

RESULTS

Fourteen patients received a total of 34 cycles of therapy. No response was observed. Fifty percent had stable disease, 50% had progressive disease after a median of two cycles of therapy. There was one treatment-related death from acute myocardial infarction. Body weight increase (>5%) occurred in 80% of cycles, and hypotension (BP <80 mm Hg systolic) occurred in 53%. Serum creatinine increase (>2 mg%) occurred in 24% of cycles, and SGOT/SGPT increase (>3x) in 10% of cycles. Symptoms of somnolence, general malaise, nausea and vomiting, pruritus, xerostomia, desquamation were generally mild to moderate but rapidly reversible.

CONCLUSION

The single modality of intravenous bolus IL-2 at the dose level of 72,000 IU/kg is clinically ineffective in NPC patients. Potential mechanisms of the ineffectiveness of IL-2 therapy on NPC patients are discussed.

Overexpression of dihydrodiol dehydrogenase as a prognostic marker of non-small cell lung cancer

By using mRNA differential display to examine specimens of non-small cell lung cancer (NSCLC), we have identified overexpression of dihydrodiol dehydrogenase (DDH) that was not detected in the corresponding normal lung tissue. Normally DDH is associated with catalysis of polycyclic aromatic hydrocarbons (PAHs) in the liver; in NSCLC cells, DDH expression would implicate an association with disease progression. In this study we investigated the prognostic significance of DDH expression in patients with NSCLC. By using immunohistochemistry, we measured DDH expression in 381 patients with NSCLC. The relationship between DDH expression and clinicopathological parameters (age, gender, smoking history, mitotic index, histological type, stage, cell differentiation, and lymphovascular invasion) was analyzed by chi2 analysis. Survival curves were plotted with the method of Kaplan-Meier, and statistical difference of survivals between different groups was compared by a log-rank test. Our results showed that DDH overexpression could be detected in 317 (83.2%) of 381 pathological sections and in 77.9% (60 of 77) of metastatic lymph nodes. Expression of DDH was confirmed by immunoblotting. Compared with patients with DDH overexpression in tumors, patients with low DDH expression had significantly lower incidence of early tumor recurrence and distant organ metastasis (46.7 versus 29.7%; P = 0.045). Interestingly, survival was also significantly better in patients with low DDH expression than in those with DDH overexpression (P = 0.0017). Using univariate analysis, we correlated three important factors, DDH overexpression, tumor stages, and gender, with poor prognosis for NSCLC patients. Nevertheless, biological function and involvement of DDH in the disease progression of NSCLC require additional studies.

Magnetic field exposure induces DNA degradation

In our earlier experiments, we discovered that magnetic field exposure could bring both stabilizing and destabilizing effects to the DNA of Escherichia coli, depending on our parameters of assessment, and both of these effects were associated with the induced synthesis of the heat shock proteins Hsp70/Hsp40 (DnaK/DnaJ). These contradicting results prompted us to explore in this study the effect of magnetic field exposure on the DNA stability in vivo when the heat shock response of the cell was suppressed. By using plasmid pUC18 in E. coli as the indicator, we found that without the protection of the heat shock response, magnetic field exposure indeed induced DNA degradation and this deleterious effect could be diminished by the presence of an antioxidant, Trolox C. In our in vitro test, we also showed that the magnetic field could potentiate the activity of oxidant radicals.

Bacterial infection in patients with transfusion-dependent beta-thalassemia in central Taiwan

The microorganisms, outcome of infections and the risk factors were evaluated in 39 patients with beta-thalassemia who received frequent blood transfusions. Among these patients, thirteen developed 22 episodes of infections, and bacteremia accounted for 72.7% (16/22) of all infections. Three patients developed meningitis, two patients had liver abscesses, three patients had soft tissue infections, one patient had a urinary tract infection and one patient had lobar pneumonia. Interestingly, a large proportion of the patients were infected by Gram-negative bacteria. Patients who were implanted with intravascular catheters were most susceptible to bacterial infection (1.70 episodes/patient) (P = 0.0069). So were patients with ferritin levels over 2,000 ng/mL (1.18 episodes/patient) (P = 0.028). The frequency of bacterial infections in patients with splenectomies (1.08 episode/patient) was also significantly higher than that of the average patient (P = 0.025). In conclusion, three major risk factors for bacterial infection were identified in this group of patients: intravascular catheterization, high serum ferritin levels (> or = 2,000 ng/mL) and splenectomy. The infection rate of these patients (0.45 episode/100 patient-year) is about 20-fold higher than that of general pediatric patients (0.023 episode/100 patient-year).

Expression of fas ligand on bile ductule epithelium in biliary atresia--a poor prognostic factor

PURPOSE

The aim of this study was to investigate the possible role of Fas and Fas ligand system in biliary atresia.

METHODS

Immunohistochemical stains of Fas and Fas ligand (FasL) and in situ hybridization of Fas ligand messenger RNA (mRNA) were performed on paraffin-embedded liver specimens of 36 biliary atresia, 6 choledochal cysts, and 14 nontumorous parts of pediatric liver tumors. Apoptosis was detected by terminal deoxynucleotidyl transferase deoxy-UTP nick end labeling (TUNEL). The grade of liver fibrosis and results of bile drainage on the patients with biliary atresia were compared with the results of FasL expression.

RESULTS

Fas protein was positive on the hepatocytes and bile ductule epithelia of all the livers examined and also positive on some monocytes around the portal area in all the biliary atresia patients. FasL protein was positive on bile ductule epithelia in 10 biliary atresia patients and also positive on some monocytes in most of the biliary atresia patients. Positive signals of FasL mRNA were noted on hepatocytes in 4 biliary atresia, bile ductule epithelia in 19 biliary atresia patients, and some monocytes in most of the biliary atresia patients. Apoptotic nuclei were present among monocytes in all the biliary atresia livers but present among bile ductule epithelia only on the BA with positive FasL mRNA signals on ductule epithelium. The fibrosis grade was similar between biliary atresia with positive FasL mRNA signals and negative signals. The bile drainage was better in the biliary atresia without positive FasL mRNA signals.

CONCLUSIONS

Fas ligand expression on bile ductule epithelia in biliary atresia may be induced to counterattack the infiltrating lymphocytes. Although the factors for post-Kasai bile drainage are multiple, the authors suggest Fas ligand expression on bile ductule epithelia may be a poor prognostic factor by playing a role in the continuous damage and obliteration of intrahepatic bile ducts after Kasai operation.

Congenital enterovirus 71 infection: a case study with virology and immunohistochemistry

Previously reported enterovirus 71 (EV71) infections associated with hand-foot-mouth disease, aseptic meningitis, encephalitis, polio-like myelitis, and paralysis all have involved young children. We report a 28-year-old woman who possibly contracted EV71 infection during pregnancy. Obstetric ultrasonograms at 25 weeks of gestation revealed an abnormal placenta, as well as hepatosplenomegaly, liver calcification, excessive ascites, and mild hydrocephalus of the fetus. Presence of EV71 was determined by immunodot blotting, virus culture, and partial sequencing of the amplified product of nested reverse transcription-polymerase chain reaction. Postmortem immunohistochemistry further identified EV71 in the fetal midbrain and liver. The findings indicate that intrauterine EV71 infection is possible during pregnancy.

Virus infection in patients with histiocytic necrotizing lymphadenitis in Taiwan. Detection of Epstein-Barr virus, type I human T-cell lymphotropic virus, and parvovirus B19

The relationship of Epstein-Barr virus (EBV), type I human T-cell lymphotropic virus (HTLV-I), and parvovirus B19 to histiocytic necrotizing lymphadenitis was studied prospectively in 10 Taiwanese patients using materials obtained by fine-needle aspiration and lymph node biopsy. The presence of EBV was detected by in situ hybridization for EBV-encoded RNA expression. Immunocytochemistry was used to detect virus-encoded protein for EBV and parvovirus B19. DNA in situ hybridization and polymerase chain reaction were performed to determine the existence of HTLV-I provirus. Expressions of EBV-encoded RNA and Fas ligand were detected in all cases. Expression of EBV-encoded protein was identified in only 1 case. Neither HTLV-I nor parvovirus B19 was detected in any case.

Magnetic field exposure stimulates transposition through the induction of DnaK/J synthesis

Like some naturally occurring environmental stress factors such as heat shock and UV irradiation, magnetic field exposure is also stimulatory to transposition activity. This feature could be illustrated by a bacterial conjugation study using an Escherichia coli strain that carries the transposable element Tn5 as the donor. When the donor cultures were exposed to a low-frequency (50 Hz) magnetic field of 1.2 mT, Tn5 located on the bacterial chromosome was stimulated to transpose and settled on the extrachromosomal episome, and eventually transferred to the recipient cell through conjugation. Such transposition activity stimulation was mediated by the induced synthesis and accumulation of the heat shock proteins DnaK/J.

Clinical significance of serum soluble interleukin 2 receptor-alpha in esophageal squamous cell carcinoma

Although the serum level of soluble interleukin-2 receptor alpha (sIL-2Ralpha) has been shown to correlate with progression and prognosis of several cancers, data to support its clinical significance to esophageal squamous cell carcinoma (ESCC) are limited. This study was conducted to assess the prognostic value and source of sIL-2Ralpha in patients with ESCC. From January 1986 to June 1997, 125 patients with histopathologically confirmed ESCC were enrolled for study. Ninety-three patients underwent en bloc esophagectomy, and 32 patients with unresectable tumor underwent palliative surgery. Four (4.3%; 4 of 93) patients died of surgical complications. Serum levels of sIL-2Ralpha were measured by ELISA. Expression of IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma in the pathological section was determined, respectively, by immunohistochemistry (IHC) and in situ hybridization (ISH). Compared with the healthy control group (1020 +/-476 pg/ml, n = 103), ESCC patients tended to have significantly higher serum sIL-2Ralpha concentrations (1424 +/- 798 pg/ml, n = 121). The sIL-2Ralpha level was correlated with age, Tumor-Node-Metastasis classification, tumor stage, reading score of the IHC staining, and survival but not with the pathological grade or lymphovascular invasion. Prognosis was worse for patients with high sIL-2Ralpha levels (> or =1500 pg/ml) than for those with low serum sIL-2Ralpha levels (< 1500 pg/ml; P = 0.0209). It can be used as an independent prognostic factor of ESCC. In the pathological sections, expression of IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma was detected in 17 (18.1%), 83 (89.2%), and 83 (89.2%) cases, respectively, by IHC, and the message of IL-2Ralpha was identified in tumor cells by ISH in 30.1% (28 of 93) of the cases. Serum concentrations of sIL-2Ralpha are frequently elevated in ESCC patients and are correlated with disease progression and survival. These data indicate that, in addition to activated T cells, cancer cells could be an important source of sIL-2Ralpha in ESCC patients.

Parvovirus B19 infection in a human immunodeficiency virus-infected patient with anemia

Anemia is generally attributed to zidovudine therapy in human immunodeficiency virus (HIV)-infected patients, although parvovirus B19 infection has been reported as a rare cause. We report on a 24-year-old homosexual man infected with HIV who presented with anemia. He had received aggressive daily antiretroviral therapy (zidovudine 600 mg, lamivudine 300 mg, and saquinavir 1,800 mg) for 2 years. At the time of admission, his CD4+ count was 10 x 10(6) cells/L. A bone marrow aspirate smear showed a marked decrease in erythropoiesis and immunocytochemical staining for parvovirus B19 was positive. Parvovirus B19 viral DNA was detected in the peripheral blood using a polymerase chain reaction-based assay. Serologic studies were positive for parvovirus B19 immunoglobulin (Ig)M antibodies, but negative for IgG antibodies. The patient was treated with packed red blood cell transfusion. Zidovudine was stopped and replaced with zalcitibine 2.25 mg daily after anemia occurred. He did not receive intravenous Ig therapy because of its cost. After discontinuation of zidovudine for 1 year, anemia persisted and the patient depended on regular blood transfusions to control the anemia. This case emphasizes that, in addition to drug-related causes, parvovirus B19 infection should be included in the differential diagnosis of chronic anemia in HIV-infected individuals.

Skip colonic ulceration in typhoid ileo-colitis

Colonic skip lesions are typically described in Crohn's colitis, but this phenomenon has been recognized in ulcerative colitis (skipped appendiceal involvement), Behcet's colitis, cytomegaloviral colitis, and even in Aeromonas hydrophilia and Histoplasma capsulatum infection. However, skip lesions in typhoid ileo-colitis have not been reported in the English-language literature. We report herein a patient with skip ulcers due to typhoid fever.

MR imaging findings of enteroviral encephaloymelitis: an outbreak in Taiwan

BACKGROUND AND PURPOSE

An outbreak of enterovirus infection occurred in Taiwan from late spring to early fall of 1998. Most of the pediatric infections presented as hand-foot-mouth disease (HFMD) and herpangina. A small portion of patients had symptoms of polio-like encephalitis and paralysis. The purpose of this study was to review the MR imaging findings in CNS involvement of enterovirus infection.

METHODS

Twenty patients who had HFMD and clinical encephalitis were examined with MR imaging. T1-weighted and T2-weighted MR images were obtained. From the rectum, throat, CSF, and peripheral blood, the presence of enterovirus 71 (EV 71) was determined by virus culture, immunofluorescent microscopy, immunologic dot blotting, and reverse-transcription polymerase chain reaction.

RESULTS

MR imaging studies of 20 patients showed hyperintensity in the brain stem and spinal cord in 15 patients, as seen on T2-weighted images. The major CNS lesions were in the medulla oblongata, pons, midbrain, and the dentate nuclei of the cerebellum. In some cases, the lesions involved the spinal cord (three cases) as well as the thalamus (two cases) and putamina (one case). Five patients had normal MR imaging results. After the appropriate management for tachycardia and tachypnea, 18 patients recovered within 1 to 2 weeks. In the follow-up MR imaging examination of five patients, the lesions completely disappeared within 2 weeks to 2 months. In two patients who were still respirator-dependent, MR imaging showed the tissue destruction in the posterior portions of the medulla, pons, and the ventral horns of cervical spinal cord. In one patient, most of midbrain was damaged. The presence of EV 71 was detected in specimens from 18 patients.

CONCLUSION

Because EV 71 was identified in 18 patients, and no other virus was detected, EV 71 was determined to be the major causative agent of this encephalomyelitis. Brain stem and cervical spinal cord involvement are characteristic findings of enteroviral encephalomyelitis.

Detection of Epstein-Barr virus in esophageal squamous cell carcinoma in Taiwan

OBJECTIVE

Recently, an association between viral infection and the development of esophageal carcinoma has been reported, particularly the human papilloma virus (HPV) and Esptein-Bar virus (EBV). However, geographic variation in carcinogenesis is realized. In this study, we investigate the viral carcinogenesis and the biologic effect of viral infection on esophageal squamous cell carcinoma (ESCC) in Taiwan.

METHODS

To determine the association of viral infection (EBV and HPV) with ESCC, we applied polymerase chain reaction (PCR), immunohistochemistry, and in situ hybridization (ISH) to examine 119 surgical specimens from different sites of esophagus in 31 ESCC patients. Additionally, an immunoperoxidase method was used to detect EBV latent membrane protein-1 (LMP-1), p53, CD45RO (UCHL-1), Fas ligand (Fas L), and RNA ISH with oligonucleotide sequences was used to detected interleukin-6 (IL-6) mRNA.

RESULTS

By PCR, EBV DNA was detected in 11 cases (35.5%). Expression of EBERs in ESCC was further confirmed with ISH. Nonetheless, no LMP-1 expression was detected. On the other hand, human papillomavirus (HPV) was identified in only one case (3.2%) of ESCC. Furthermore, HPV was located by ISH in the distant normal region rather than in tumor cells. In EBV-positive cases, accumulation of p53 protein was detected in 10 lesions (91%); CD45RO+ lymphocytes together with expressions of FasL and IL-6 were respectively identified in 100%, 63.6%, and 54.5% of 11 EBV-positive lesions. Interestingly, in the EBV-negative cases (n = 20), p53 protein was detected in 40% of lesions; CD45RO 30%; FasL 50%, and IL-6 10%.

CONCLUSIONS

In this study, no correlation was found between the presence of EBV in ESCC and the patients' age, sex, as well as survival. Although our results indicate that EBV could be associated with ESCC, the clinical role of EBV in ESCC remains to be determined.

Expression of Fas ligand in Langerhans' cell histiocytosis: A case report of a boy with multisystem involvement

Previous reports of patients with Langerhans' cell histiocytosis have shown characteristics of osteolytic lesion, visceral involvement and organ dysfunction. We report a 2-year-old boy who was diagnosed as Langerhans' cell histiocytosis with a prominent hepatomegaly. X-Radiogram, computed tomography and magnetic resonance imaging revealed the osteolysis of the right iliac bone, the absence of the left eighth rib as well as the right mandible, and an enhancing mass in the left cerebellum. The data of radiography were highly suggestive of Langerhans' cell lineage. The presence of large CD1a-positive mononuclear cells associated with inflammatory cells in peripheral blood smear and bone marrow aspirate further confirmed the diagnosis. In addition, expressions of S100, CD25, CD68, CD80, CD86, and Fas ligand were identified on these cells by immunocytochemical staining. The results indicate that although these cells are activated Langerhans' cells, progression of the disease and the bone destruction could be mediated by the overt FasL expression of the cells.

High alpha-fetoprotein level in HCV-related nodular liver cell dysplasia

The diagnosis of hepatocellular carcinoma is generally made in patients with a mass lesion in the cirrhotic liver if the alpha-fetoprotein level is >1,000 ng/L. Other causes of elevation of alpha-fetoprotein to this extreme degree include nonseminomatous germ cell tumor and hepatic metastasis. However, it is extremely rare for benign hepatic lesions to cause alpha-fetoprotein of > 1,000 ng/ml. We report a Chinese patient with spontaneous normalization of alpha-fetoprotein with an initial value > 10,000 ng/ml due to nodular dysplasia complicating hepatitis C-related liver cirrhosis. The alpha-fetoprotein was secreted from the dysplastic liver cells.

Expression and up-regulation of interleukin-6 in oesophageal carcinoma cells by n-sodium butyrate

Recently, the serum level of interleukin (IL)-6 has been shown to correlate with disease progression and prognosis of cancer patients. However, the available information about the source and the pathophysiological regulation of IL-6 in cancer cells is limited. Thus, in this study, we tried to identify the source and the clinical roles of serum IL-6 in patients with oesophageal squamous cell carcinoma (ESCC), and then further to characterize the biological regulation of IL-6 in ESCC cell lines. Sera and tissue specimens from 80 consecutive patients with ESCC were collected between 1993 and 1997. Additionally, three ESCC cell lines were used for in vitro study. The concentration of serum IL-6 was measured by enzyme-linked immunosorbent assay (ELISA), and correlated the survival time with measured IL-6 level. Expressions of IL-6, IL-6R alpha (IL-6 receptor alpha) and gp130 in pathological sections and cell lines were characterized by immunological staining. Detection of IL-6 mRNA was determined by in situ hybridization (ISH) and reverse transcription-polymerase chain reaction (RT-PCR). Up-regulation of IL-6 by n-sodium butyrate (n-BT) was studied in ESCC cell lines. The levels of serum IL-6 in patients with ESCC were significantly higher than those in the healthy controls. Serum levels of IL-6 were also shown to correlate with disease progression and survival. However, sCD8 levels and lymphocyte counts in the peripheral blood were not parallel to the changed pattern of serum IL-6. In pathological sections and ESCC cell lines, message of IL-6 was identified by ISH in cancer cells. Expression of IL-6 mRNA was further confirmed with RT-PCR in ESCC cell lines. Although IL-6 was detected in some ESCC cell lines, IL-6 gene expression and protein production could be induced or enhanced by n-BT treatment in all three cell lines. The serum levels of IL-6 are frequently elevated at diagnosis of ESCC, and are associated with poor prognosis. IL-6 that could be produced by cancer cells is up-regulated by n-BT.

Prognosis of esophageal squamous cell carcinoma: analysis of clinicopathological and biological factors

OBJECTIVE

Esophageal squamous cell carcinoma (ESCC) is rather common among the Chinese, but the therapeutic outcome is dismal. Knowledge of the prognostic factors in cancerous patients may influence therapeutic strategy. However, systemic analyses of clinicopathological and biological factors for patients with ESCC are few, and the results are controversial.

METHODS

Between 1985 and 1996, 117 patients undergoing en bloc esophagectomy and gastric substitution were enrolled. None had neoadjuvant treatment. Postoperative adjuvant therapy was provided for patients at and beyond stages IIa. Clinical responses were followed routinely. Flow cytometry was used to measure DNA ploidy and synthesis-phase fraction (SPF) of the resected esophageal tissues from all patients. Immunohistochemistry was also used to examine the expression of proliferating cell nuclear antigen (PCNA), epidermoid growth factor receptor (EGFR), HER-2/neu, and p53 in the pathological sections. Clinical correlation was evaluated by chi2 with Fisher's exact test, and survival by log-rank test.

RESULTS

The overall survival rates were 74% for 1 yr, 48% for 3 yr, and 38% for 5 yr. TNM tumor staging, the number of diseased lymph nodes (N < or = 3 or N > 3), degree of cell differentiation, DNA ploidy, SPF, and lymphovascular invasion were more useful than biological markers, such as PCNA, EGFR, HER-2/neu, and p53, for the prognosis of ESCC. Multivariate analysis revealed significant correlation of tumor staging and number of diseased lymph nodes with patient survival after surgery.

CONCLUSIONS

En bloc esophagectomy may provide a rather satisfactory survival rate for patients with early stage ESCC. However, for patients with distant lymph node metastasis and those with more than three lymph nodes involved, radical surgical resection, even combined with postoperative chemoradiotherapy, cannot improve survival. The prognostic value of biological markers, including PCNA, EGFR, HER-2/neu, and p53, however, is limited.

Expression of nm23 in the primary tumor and the metastatic regional lymph nodes of patients with gastric cardiac cancer

Tumor recurrence and distant metastasis are major causes of treatment failure in gastric cardiac cancer (GCC). Rapid growth of tumor cells and reduced expression of nm23, a metastatic suppressor gene, in tumor cells have been suggested as two important mechanisms for disease progression of GCC. Therefore, to determine the prognostic value of nm23 expression in GCC, we used immunohistochemistry to examine the expression of nm23 in the pathological sections of both gastric cancer and metastatic lymph nodes from 24 stage III patients. Twenty-two patients had total gastrectomy, and two patients had proximal subtotal gastrectomy with a D2 dissection. Postoperative adjuvant therapy was provided, and the clinical responses were followed routinely. Clinical correlation was evaluated by chi2 with Fisher's exact test and survival by log-rank test. Our results show that the reduced nm23 expression in the primary tumor and in the nodal metastasis is the most useful marker for the poor prognosis of GCC following surgery.

Apoptosis in primary cutaneous amyloidosis

Amyloid deposits in primary cutaneous amyloidosis (PCA) may be initially derived from cytokeratin. possibly after keratinocyte death. However, the mechanism of keratinocyte death remains obscure. To investigate the potential role of apoptosis in the pathogenesis of PCA, a retrospective study was conducted on the skin tissues from 20 Chinese patients with PCA. We used a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) method for detecting the apoptotic cells. Immunohistochemical staining was performed to examine the expression of the B-cell leukemia/lymphoma-2 gene (bcl-2) and Fas. Apoptotic cells were shown in 11 of 20 cases (55%) by TUNEL. Histological sections showed that dyskeratotic cells and vacuolar alteration of the basal cells were more commonly observed in the TUNEL-positive group. In all cases of PCA, epidermal expression of bcl-2 was minimal, while expression of Fas was observed on keratinocytes in the basal to granular layers: however, these findings were not different from those in normal skin. Our results suggest that the keratinocyte destruction in PCA may occur as an initial result of apoptosis, which in turn leads to the amyloid formation.

Overexpression of dnaK/dnaJ and groEL confers freeze tolerance to Escherichia coli

Heat shock proteins not only can protect host cells against heat stress, they can also enable freeze tolerance as well. With respect to this unexpected feature, we are able to show that, at least in Escherichia coli, the heat shock proteins DnaK/DnaJ and GroEL play a very significant role. We found that the recovery rate of E. coli cultures that had been stored at -80 degreesC in the absence of any cryoprotectant was related to the abundance of these heat shock proteins accumulated before the freeze treatment. Before freezing, the DnaK in the bacterial cells was induced to accumulate to a level comparable to that produced in response to heat shock. After the freezing treatment, the recovery rate of the induced culture was very similar to that of the heat-shocked culture. Over production of GroEL was also protective but less effective. While freezing inevitably leads to protein denaturation, we propose that advance synthesis of DnaK/DnaJ and GroEL can accordingly prevent irreversible denaturation by chaperoning the unfolded polypeptides during freezing.

The significance of soluble interleukin-2 receptor in monitoring disease relapse in patients with nasopharyngeal cancer

BACKGROUND

Soluble interleukin-2 receptor alpha (sIL-2R alpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. However, the significance of sIL-2R alpha in monitoring disease relapse is unclear. This study was initiated to address this issue.

METHODS

Serum of 56 patients with NPC, which underwent either primary, salvage, or palliative treatments, from 1992 to 1993 at the Cancer Center, Veterans General Hospital-Taipei, were collected from our serum bank. According to their disease status at the time of study, at least two years after last treatments, the 56 patients were divided into four groups. The remission group represented those in remission at the time of study (n = 24). The metastasis group represented those with distant metastasis present at the time of study (n = 17). The recurrence group represented those with locoregional recurrence present at the time of study (n = 11). The combined group represented those with locoregional recurrence as well as distant metastasis (n = 4). The seral sIL-2R alpha concentrations of the 56 NPC patients were determined with enzyme-linked immunoabsorbent assay. The combined group was excluded in our statistical analysis. We performed statistical analysis on the differences of paired serum sIL-2R alpha concentrations between different periods of the diseases. The first analysis was on the differences of sIL-2R alpha concentrations between diagnosis and post-radiotherapy periods for 13 out of 24 patients in the remission group and 7 out of 11 patients in the recurrence group. The second analysis was on the differences of sIL-2R alpha concentration between follow-up before detection-of-relapse and after detection-of-relapse for 5 out of 17 patients in the metastasis group and six out of 11 patients in the recurrence group.

RESULTS

The first statistical analysis revealed no significant differences of sIL-2R alpha concentrations for the remission group (P = 0.946) and the recurrence group (P = 0.156) between diagnosis and post-radiotherapy periods. The second statistical analysis revealed no significant differences of sIL-2R alpha concentrations between before and after detection-of-relapse for the recurrence group, neither (P = 0.438). The results for the metastasis group were different. The sIL-2R alpha concentrations were shown to increase after the detection of metastasis for the 5 paired samples from the metastasis group, although the Wilcoxon signed ranks test on the differences only showed borderline significance (P = 0.063).

CONCLUSIONS

Our findings show that sIL-2R alpha would be of no value in monitoring the development of locoregional recurrence but might be useful in monitoring distant metastasis. Although our current limited data did not provide strong support for the role of sIL-2R alpha in monitoring metastasis, it might be delineated in the future by collecting more data.

Prognostic significance of HER-2/neu overexpression in stage I adenocarcinoma of lung

BACKGROUND

Even with early diagnosis and adequate resection, the 5-year survival rate for stage I lung cancer patients is around 60% to 70%. Overexpression of HER-2/neu protein is associated with poor prognosis in lung cancers. In this study, we evaluated the expression of HER-2/neu in cancer cells of lung and assessed their clinicopathologic and prognostic significance.

METHODS

From 1986 to 1995, clinical data on 42 consecutive patients who underwent complete surgical resection for stage I lung adenocarcinoma were collected. Expression of HER-2/neu in paraffin-embedded tumor samples was determined by immunohistochemistry and scored with a semiquantitative method.

RESULTS

Twenty-one of 42 patients were positive for HER-2/neu overexpression in tumor. Compared with patients with low HER-2/neu expression, patients with HER-2/neu overexpression had a significantly higher incidence of early tumor recurrence (p = 0.014). Survival was also significantly better in patients without HER-2/neu overexpression than in those with HER-2/neu overexpression (p = 0.0047). By univariate analysis, HER-2/neu overexpression and poor cell differentiation are two important factors correlated with poor prognosis.

CONCLUSIONS

Expression of HER-2/neu oncoprotein in stage I lung adenocarcinoma can predict the tumor's aggressiveness. Early tumor recurrence was frequently detected in patients with HER-2/neu overexpression. We recommend an individualized therapeutic strategy based on the level of HER-2/neu oncoprotein in the tumor cells.

Construction of an efficient Bacillus subtilis system for extracellular production of heterologous proteins

An efficient expression/secretion vector, designated pM2Veg, was constructed for extracellular production of heterologous proteins in Bacillus subtilis. To construct pM2Veg, a synthetic cassette, the Veg cassette carrying: (1) the strong vegetative vegI promoter from B. subtilis, (2) the Escherichia coli lac operator, (3) the B. subtilis consensus ribosome-binding site, (4) the Staphylococcal protein A leader sequence, (5) a cloning region for insertion of foreign genes, (6) translational stop codons in all three reading frames, and (7) the gnt transcriptional terminator, was cloned into a derivative of the stable pRB373 B. subtilis/E. coli shuttle plasmid, the pM2 vector. The application of pM2Veg to effect secretory production of heterologous proteins was illustrated using two widely different proteins: the endoglucanase (Eng) encoded by the cenA gene of Cellulomonas fimi and human epidermal growth factor (hEGF). Levels of Eng and hEGF measured in culture supernatant samples of B. subtilis transformants harboring recombinant constructs formed between pM2Veg and the cenA and hEGF genes were 8.3 U ml-1 and 7.0 mg l-1, respectively. The Eng activity is more than four times higher than the yield from the best cenA recombinant construct previously reported, and the hEGF data represents the first successful expression of the factor in B. subtilis.

Expression of Epstein-Barr virus in patients with Hodgkin's disease in Taiwan

BACKGROUND

The association of Epstein-Barr virus (EBV) with Hodgkin's disease (HD) is intimately related to socioeconomic status. The proportion of HD patients with EBV is high in developing countries but low in developed countries. The aim of this study was to delineate the association of EBV with HD in Taiwan.

METHODS

Tissues from 70 consecutive cases of HD were examined for the presence of EBV, for the latent membrane protein (LMP- 1) by immunohistochemistry, and for EBER-1 by in situ hybridization.

RESULTS

There were 53 males and 17 females, with a mean age of 42 years (range, 7-75 years). Histologic subtypes included nodular sclerosis in 36 cases (51.4%), mixed cellularity in 26 (37.1%), lymphocyte predominance in 6, and lymphocyte depletion in 2. Overall, EBV was expressed in 44 cases (62.9%), with EBER-1 expression detected in 40 (57.1%) and LMP-1 detected in 38 (54.3%). The following histologic subtypes were associated with EBV: lymphocyte predominance in 1 of 6 cases (16.7%), nodular sclerosis in 23 of 36 cases (63.9%), mixed cellularity in 18 of 26 cases (69.2%), and lymphocyte depletion in 2 of 2 cases (100%).

CONCLUSIONS

EBV association with HD is relatively high in Taiwan. Although EBV was detected in all subtypes and at all ages in this study, the low endemic incidence of HD in Taiwan suggests that other factors, besides EBV, play a role in the pathogenesis of HD.

p53 gene alternation in squamous cell carcinoma of the esophagus detected by PCR-cold SSCP analysis

Mutations of the p53 tumor suppressor gene play an important role in the development of common human malignancies. Previous reports revealed that the frequencies of p53 alternations in esophageal carcinoma varied from 26% to 87%. The clinical significance of p53 alternations is still disputed. In the present study, we used polymerase chain reaction--"cold" single-strand conformation polymorphism (PCR-"cold" SSCP)--to investigate p53 genetic alternations in 63 surgical specimens of esophageal squamous cell carcinoma (ESC). Our experiments showed that the optimum buffer temperature for "cold" SSCP analysis was 14 degrees C while the PCR products were around 200-300 bp in size. Among 63 tumorous samples, p53 alternations was detected in 47 tumors, or an incidence rate of 74.6%. For nontumorous mucosal samples, the incidence of p53 alternations was 55.5% (35/63 samples). Additionally, p53 alternations occurred most frequently at exon 6 (50.8%), followed by exon 7 (33.3%), exon 8 (17.5%) and exon 5 (12.7%). Multiple genetic alternations (> or = 2 exons) between p53 exons 5-8 in the same examined samples were found in 21 (33.3%) of 63 tumors, and in 8 (12.7%) of 63 nontumorous mucosal specimens. Our results further showed that p53 alternations did not correlate with age, depth of tumor invasion, lymph node metastasis, tumor stage, cell differentiation or lymphovascular invasion in ESC (P > 0.05). Moreover, the survival rate in patients with p53 alternations was similar to that in patients without p53 alternations (P > 0.05). In conclusion, PCR-"cold" SSCP is a rapid and sensitive method for identifying p53 genetic alternations. p53 genetic alternations occur with a relatively high incidence for ESC, but p53 abnormality has no impact on prognosis.

Detection of Epstein-Barr virus and HTLV-I in T-cell lymphomas of skin in Taiwan

Viral etiology has been associated with the pathogenesis of T-cell lymphomas of skin (TCLS). Therefore, we studied the presence of Epstein-Barr virus (EBV) and type I human T-cell lymphotropic virus (HTLV-I) in tumor cells of TCLS to determine the significance of these viruses with the disease. A retrospective study was conducted on the skin tissues from 28 Chinese patients with TCLS. We used in situ hybridization, immunohistochemistry, and polymerase chain reaction to determine the presence of viruses. Among the 28 cases, HTLV-I was only detected in two cases with adult T-cell leukemia/lymphoma, not in other cases of TCLS. This suggests that HTLV-I may not play a significant role in the oncogenesis of TCLS in Chinese patients. Conversely, EBV was detected in 12 cases (42.9%), including the secondary TCLS, large cell lymphoma, mycosis fungoides, adult T-cell leukemia/lymphoma, and angiocentric lymphoma. Nevertheless, latent membrane protein 1 was not detected in any of the EBV-positive cases. Neither was any correlation found between the presence of EBV in TCLS and the prognosis or the severity of the skin lesion. Although there is a close association of EBV with a portion of TCLS, its pathogenic role needs further investigation.

Catalase prevents estradiol-induced chondrocyte cytotoxicity

Osteoarthritis is a common geriatric disease and estrogen may play an important role in this disease. Estradiol may cause chondrocyte damage as suggested by in vitro and in vivo data. One of the possible mechanisms of estradiol-induced chondrocyte damage was thought to be related to free radicals. Whether catalase, a known free radical scavenger, can prevent estradiol-induced chondrocyte damage was tested using a chondrocyte culture system. The results of this study suggest that catalase can significantly reduce the estradiol-induced damage to chondrocytes. Apparently, catalase alters the molecular structure of estradiol as indicated by the absorption spectrum of estradiol with time. The modified estradiol may decrease its toxicity to the chondrocytes. However, the contents of free radicals in the treated chondrocytes have no significant difference from the untreated control cells. Studies to further investigate the mechanism or prevention of estradiol-induced chondrocyte damage in osteoarthritis are warranted.

Penicillium marneffei infection and solitary pulmonary nodule

We report on a patient infected with human immunodeficiency virus who presented with fever, a solitary pulmonary nodule, and cervical lymphadenopathy. The diagnosis of Penicillium marneffei infection was made from an excisional lymph node biopsy and a sputum culture. The microbiology, pathology, diagnosis, and treatment of the case are discussed. A high level of clinical suspicion is necessary for making an early diagnosis and improving the outcome of infection.

Expression of DNA topoisomerase II alpha and multidrug resistance p-glycoprotein in acute leukemia

BACKGROUND

Drug resistance is a major cause of treatment failure in acute leukemia. Overexpression of multidrug resistance gene and decreased activity of topoisomerase II alpha are suggested as two important mechanisms for this resistance.

METHODS

We used immunohistochemical method to determine the expressions of both topoisomerase II alpha (topo II alpha) and p-glycoprotein (gp-170) in bone marrow biopsy specimens from 68 cases of acute leukemia. Patients were divided into four groups: (1) leukemia cells with high score for topo II alpha and negative for gp-170; (2) leukemia cells with high score for topo II alpha and positive for gp-170; (3) leukemia cells with low score for topo II alpha and negative for gp-170; and (4) leukemia cells with low score for topo II alpha and positive for gp-170. The clinical responses were then followed as routine, and the clinical correlation was evaluated by analysis of variance and Pearson Chi-Square test.

RESULTS

The measure of the single parameter (either topo II alpha or gp-170 alone) did not show a significant difference in the overall survival. However, the complete response rate was much higher in the first group patients whose bone marrow reading score was high in topo II alpha and negative for gp-170 expression. Survival duration increased with the increase in the complete response rate.

CONCLUSIONS

Combined parameters of topo II alpha and gp-170 are more useful than any individual parameter for the prognosis of acute leukemia.

Occult gastric cancer presenting as cor pulmonale resulting from tumor cell microembolism

Cor pulmonale resulting from tumor emboli is a rare presentation of gastric cancer, and only six similar cases have been reported in the English literature. We report the case of a 37-yr-old woman presenting with dyspnea who died of cor pulmonale. Autopsy revealed signet cell carcinoma of te stomach with intra-abdominal metastasis and right ventricular hypertrophy. There were no macroscopic pulmonary emboli or parenchymal lesions, but more than 60% of the small pulmonary arteries and arterioles were occluded. In most vessels, fibrocellular intimal proliferation was the major finding with only a few entrapped tumor cells.

Detection of Epstein-Barr virus in primary cutaneous amyloidosis

To determine the association of Epstein-Barr virus (EBV) with primary cutaneous amyloidosis (PCA), a retrospective study was conducted on skin tissue from 27 Chinese patients with lichen amyloidosus and macular amyloidosis. In situ hybridization with oligonucleotide probes was used to detect the expression of EBV-encoded RNAs (EBERs). Eleven of 27 cases (40.7%) were found to contain the EBV genome. No EBV genome was detected in the skin of the control groups, including three cases of secondary cutaneous amyloidosis, two cases of primary systemic amyloidosis, and four cases of lichen simplex chronicus. Our study showed no correlation between the presence of EBV in PCA patients and the patients' age, sex, clinical type or severity of the skin lesions. Although our results suggest that EBV may be associated with some cases of PCA, the true aetiological role of EBV in PCA remains unknown.

Serum responses to the combination of Epstein-Barr virus antigens from both latent and acute phases in nasopharyngeal carcinoma: complementary test of EBNA-1 with EA-D

Elevated serum IgA to antigens of EBV is associated with nasopharyngeal carcinoma (NPC). We have tested 620 NPC sera by ELISA for the presence of antibodies to EBV-encoded DNA binding protein, EBV-specific DNA polymerase, early antigen-diffused (EA-D), EBV nuclear antigen 1 (EBNA-1), EBV-specific thymidine kinase, and BamHI Z fragment EBV replication antigen. Sensitivity of these proteins was in the range of 51.5-79.5% for IgA and 69.4-82.8% for IgG. The complementary use of EBNA-1 with EA-D, however, could increase the sensitivity significantly to 98.1%. Western blot analysis further showed that the combination of EBNA-1 and EA-D is most useful for the detection of NPC. This is the first report of using double biomarkers including EBV gene products from both latent and active infections. The results of this study suggest that EBV in NPC may not be latent alone and that the method may be valuable for the early detection, early treatment, and better survival rate of patients with NPC. Because the application of recombinant EBV protein in ELISA is cost-effective and feasible for mass screening, the method may be of worth for further clinical investigation.

Isolation and characterization of the Bacillus subtilis tryptophanyl-tRNA synthetase gene (trpS) conferring 5-fluorotryptophan resistance and temperature sensitivity

The mutant trpS gene of Bacillus subtilis encoding a thermosensitive tryptophanyl-tRNA synthetase that also confers resistance to growth inhibition by 5-fluorotryptophan at permissive temperature has been isolated and characterized. A point mutation at codon 82 of the gene from a wild-type TCA codon for Ser to a TTA codon for Leu has been identified.