Characterization of the BcLF1 promoter in Epstein-Barr virus

The location of the BcLF1 promoter of Epstein-Barr virus (EBV) has been identified by primer extension, which indicates that the +1 site of the BcLF1 mRNA is located at nucleotide 137676 of the EBV genome. According to deletion analysis, the region upstream from nucleotide -38 is not essential for transcription of BcLF1. A 23 bp region in the promoter, from nucleotide -38 to -16, was identified as necessary for regulating the expression of BcLF1, i.e. the promoter activity is activated by 12-O-tetradecanoylphorbol 13-acetate but is repressed by phosphonoacetic acid. The results presented also demonstrate that the oriLyt sequence in cis is essential for enhancing the expression of BcLF1.

Helicobacter pylori infection and mode of transmission in a population at high risk of stomach cancer

BACKGROUND

Helicobacter pylori (H. pylori) is a recognized cause of chronic gastritis and peptic ulcer disease, and is strongly suspected to play a role in the aetiology of stomach cancer but little is known about the mode of transmission.

AIM

To determine the prevalence of H. pylori infection in children and investigate potential modes of transmission in rural China.

SUBJECTS AND SETTING

We examined 98 children aged 3-12 years and 289 adults aged 35-64 years in a village in Linqu County, China, which has one of the highest rates of stomach cancer in the world.

METHOD

H. pylori infection was determined by 13C-urea breath test in children and by an enzyme-linked immunosorbent assay in adults.

RESULTS

Among 98 tested children, 68 (69%) were H. pylori positive, but the prevalence rates varied as a function of age, rising from about 50% at ages 3-4 to 85% at ages 9-10 before falling to 67% at ages 11-12. Boys had a higher infection rate than girls (77.8% versus 59.1%, P < 0.05). Among 289 adults, 195 (68%) were H. pylori positive, with a somewhat higher rate of positivity in younger compared to older age groups. The prevalence of H. pylori infection clustered within families. In families with at least one infected parent, 85% of children were H. pylori positive, while in families with both parents uninfected, only 22% of children were H. pylori positive (odds ratio [OR] = 30.4, 95% CI : 4.0-232).

CONCLUSIONS

These findings demonstrate the acquisition of H. pylori infection during early childhood in a population at high risk of stomach cancer, in a manner consistent with a person-to-person mode of transmission between parents and children.

Factorial trial of three interventions to reduce the progression of precancerous gastric lesions in Shandong, China: design issues and initial data

In the fall of 1995, 3411 subjects in 13 rural villages in Linqu County, Shandong Province, China, began participating in a blinded, randomized 23 factorial trial to determine whether interventions can reduce the prevalence of dysplasia and other precancerous gastric lesions. One intervention is treatment for infection by Helicobacter pylori with amoxicillin and omeprazole. A second is dietary supplementation with capsules containing vitamin C, vitamin E, and selenium. A third is dietary supplementation with capsules containing steam-distilled garlic oil and Kyolic aged garlic extract. Investigators will evaluate histopathologic endpoints after gastroscopies with biopsies from seven standard sites in 1999. Initial data from pill counts and sampled blood levels of vitamin E, vitamin C, and S-allylcysteine indicate excellent compliance. Subjects have tolerated all interventions well, although 3.1% of those assigned to amoxicillin and omeprazole developed rashes, compared to 0.3% to those in the control group. Preliminary breath tests demonstrate substantial reductions in gastric urease activity, an indication of infection by Helicobacter pylori, among those assigned to amoxicillin and omeprazole.

Effect of hyperglycemia on brain cell membrane function and energy metabolism during hypoxia-ischemia in newborn piglets

The purpose of this study was to test the hypothesis that hyperglycemia ameliorates changes in brain cell membrane function and preserves cerebral high energy phosphates during hypoxia-ischemia in newborn piglets. A total of 42 ventilated piglets were divided into 4 groups, normoglycemic/normoxic(group 1, n=9), hyperglycemic/normoxic(group 2, n=8), normoglycemic/hypoxic-ischemic(group 3, n=13) and hyperglycemic/hypoxic-ischemic(group 4, n=12) group. Cerebral hypoxia-ischemia was induced by occlusion of bilateral common carotid arteries and simultaneous breathing with 8% oxygen for 30 min. Hyperglycemia (blood glucose 350-400 mg/dl) was maintained for 90 min before and throughout hypoxia-ischemia using modified glucose clamp technique. Changes in cytochrome aa3 were continuously monitored using near infrared spectroscopy. Blood and CSF glucose and lactate were monitored. Na+, K+-ATPase activity, lipid peroxidation products (conjugated dienes), tissue high energy phosphates (ATP and phosphocreatine) levels and brain glucose and lactate levels were determined biochemically in the cerebral cortex. During hypoxia-ischemia, glucose levels in blood and CSF were significantly elevated in hyperglycemic/hypoxic-ischemic group compared with normoglycemic/hypoxic-ischemic group, but lactate levels in blood and CSF were not different between two groups. At the end of hypoxia-ischemia of group 3 and 4, triangle up Cyt aa3, Na+, K+-ATPase activity, ATP and phosphocreatine values in brain were significantly decreased compared with normoxic groups 1 and 2, but were not different between groups 3 and 4. Levels of conjugated dienes and brain lactate were significantly increased in groups 3 and 4 compared with groups 1 and 2, and were significantly elevated in group 4 than in group 3 (0.30+/-0.11 vs. 0.09+/-0.02 micromol g-1 protein, 26.4+/-7.6 vs. 13.1+/-2.6 mmol kg-1, p<0.05). These findings suggest that hyperglycemia does not reduce the changes in brain cell membrane function and does not preserve cerebral high energy phosphates during hypoxia-ischemia in newborn piglets. We speculate that hyperglycemia may be harmful during hypoxia-ischemia due to increased levels of lipid peroxidation in newborn piglet.

Effect of induced hyperglycemia on brain cell membrane function and energy metabolism during the early phase of experimental meningitis in newborn piglets

This study was done to elucidate the mechanism of hypoglycorrhachia and elevated lactate concentrations leading to neuronal dysfunction in neonatal meningitis, and to determine the effects of induced hyperglycemia on these disturbances. Thirty-eight newborn piglets were divided into three groups: 12 in the control group (CG), 12 in the normoglycemic meningitis group (NG), and 14 in the hyperglycemic meningitis group (HG). Meningitis was induced by intracisternal injection of 108 cfu of Escherichia coli. Hyperglycemia (blood glucose 300-400 mg dl-1) was induced and maintained for 60 min before induction of meningitis and throughout the experiment using modified glucose clamp technique. CSF-to-blood glucose ratio decreased significantly in NG. In HG, baseline CSF-to-blood glucose ratio was lower than two other groups, but increased at 1 h after induction of meningitis. CSF lactate concentration was increased progressively in both meningitis groups, and positively correlated with CSF leukocyte numbers (r=0.41, p<0.001) and TNF-alpha level (r=0.43, p<0.001). Brain glucose concentration was significantly increased in HG and showed inverse correlation with CSF leukocyte numbers (r=-0.59, p<0.01). Brain lactate concentration was not significantly different among three groups and positively correlated with the CSF TNF-alpha level (r=0.51, p<0.05). Lipid peroxidation products were increased in NG. Na+,K+-ATPase activity, ATP/PCr concentrations were not different among three groups. Increased intracranial pressure, CSF pleocytosis (214+/-59 vs. 437+/-214/mm3, p<0.02) and increased lipid peroxidation products observed in NG were reduced in HG. These results suggest that hypoglycorrhachia and elevated lactate concentration in the CSF during meningitis originates primarily from the increased anaerobic glycolysis in the subarachnoid space, induced by TNF-alpha and leukocytes. Induced hyperglycemia attenuates the inflammatory responses of meningitis and might be beneficial by providing an increased glucose delivery to meet its increased demand in meningitis.

Dopamine transporter imaging with [123I]-beta-CIT demonstrates presynaptic nigrostriatal dopaminergic damage in Wilson's disease

OBJECTIVES

The most common neurological manifestations in Wilson's disease are parkinsonism and dystonia. These are assumed to be due to striatal injury, which has been repeatedly demonstrated by pathology and CT or MRI. The substantia nigra has not been shown to be damaged in pathological studies. However, there have been clinical and imaging studies suggesting presynaptic nigrostriatal injury. (1r)-2Beta-carbomethoxy-3beta-(4-iodophenyl)tropane (beta-CIT) is a specific ligand that binds to the dopamine transporter (DAT), and can examine the integrity of dopaminergic nerve terminals. Evidence for presynaptic nigrostriatal dopaminergic damage in Wilson's disease was searched for using [123I]-beta-CIT SPECT.

METHODS

Six patients with Wilson's disease were studied, together with 15 healthy normal controls, and six patients with Parkinson's disease. After injection of [123I]-beta-CIT, SPECT studies were done at 18 hours. Specific striatal/occipital binding ratio (S/O ratio) was calculated as (striatal binding-occipital binding)/occipital binding.

RESULTS

The specific S/O ratios were 6.22 (1.32) (mean (SD)) in normal volunteers, 3.78 (0.65) in Parkinson's disease, and 3.60 (0.49) in Wilson's disease.

CONCLUSION

There was severe loss of the DAT in the striatum suggesting significant damage in presynaptic nigrostriatal dopaminergic nerve terminals. Therefore, a presynaptic lesion may contribute to neurological manifestations in Wilson's disease.

Transcriptional activation of NF-kappa B activity by Epstein-Barr virus (EBV) LMP1 as a selective therapeutic strategy for EBV-associated diseases

Epstein-Barr virus (EBV) has been known to be associated with many malignant tumors, including nasopharyngeal carcinoma (NPC). Previous studies have indicated that an EBV-encoded oncoprotein, latent membrane protein 1 (LMP1), is expressed in many NPC tissues. LMP1 has been shown to stimulate HIV LTR through the two NF-kappa B binding sites within this promoter. In this study, we examined the feasibility of using this property of LMP1 as a therapeutic strategy for the treatment of NPC. This therapy consists of the preferential killing of the LMP1-expressing cells by gene transfer using the NF-kappa B-mediated herpes simplex virus thymidine kinase (HSVtk)/ganciclovir (GCV) system. The 800-bp HIV-LTR, which contains two NF-kappa B binding sites, was used to drive the HSVtk gene. Stable C33A cell clones expressing the LMP1 and the HSVtk genes were subjected to the GCV sensitivity test. Results showed that cells expressing both the LMP1 and the HSVtk genes were highly sensitive to GCV treatment. These cells were introduced into nude mice subcutaneously and tumors became palpable within 2 weeks. GCV was then introduced intraperitoneally to these mice and the sizes of the tumors were measured daily. Results showed that the tumors regressed in the group of mice carrying cells that stably expressed both the LMP1 and the HSVtk genes, but not in mice carrying cells containing LMP1 or HSVtk alone. Our data indicate that the HSVtk gene expressed from a NF-kappa B-binding motif-containing promoter that is regulated by LMP1 may be used as an in vivo gene therapy strategy of EBV LMP1-expressing cancers such as NPC.

Influence of antithyroid antibodies in euthyroid women on in vitro fertilization-embryo transfer outcome

PROBLEM

To investigate whether antithyroid antibodies (ATAs) affect the pregnancy outcome in euthyroid women undergoing in vitro fertilization-embryo transfer (IVF-ET).

METHOD OF STUDY

Thyroid peroxidase antibody (TPOA) and thyroglobulin antibody (TGA) were measured by radioligand assay kits that were used as ATAs in 79 patients with tubal or unexplained infertility who were enrolled in an IVF-ET program. Women who were positive for antinuclear antibody, lupus anticoagulant, anticardiolipin antibody, and rheumatoid factor were excluded from our study. The study group comprised 28 (29.1%) euthyroid women who were positive for TPOAs, TGAs, or both. Fifty-one euthyroid women without ATAs served as control subjects. The results were analyzed with linear regression analysis, Student's t-test, Mann-Whitney U test, Kruskal-Wallis analysis of variance, chi 2 test, and Fisher's exact test.

RESULTS

There were no significant differences between the study group and the control group in patient characteristics such as age, infertility duration, and hormonal profile. There were also no significant differences between the two groups with respect to the number of retrieved oocytes, the fertilization rate, the number of embryos frozen, and the number of embryos transferred. There were no correlations between ATA (TPOA and TGA) titers and the fertilization rate. The clinical pregnancy rate per cycle was significantly lower in the study group, with 26.3% (10/38), compared with 39.3% (35/89) in the control group. The biochemical pregnancy rate per cycle and the miscarriage rate were significantly higher in the study group, 18.4% (7/38) and 40.0% (4/10), respectively, compared with 5.6% (5/89) and 11.4% (4/35), respectively, in the control group. In the study group, both TPOA and TGA titers were significantly higher in the biochemical pregnancy group than in the clinical pregnancy group or the nonpregnancy group. In 10 women with ATAs who achieved pregnancy after IVF-ET, both TPOA and TGA titers were significantly higher in the miscarriage group than in the ongoing pregnancy/delivery group.

CONCLUSION

ATAs in euthyroid women with tubal or unexplained infertility have an association with a poor pregnancy outcome after IVF-ET treatment.

Supercritical carbon dioxide extraction of podophyllotoxin from Dysosma pleiantha roots

Supercritical fluid extraction (SFE) was utilized to extract podophyllotoxin from the roots of Dysosma pleiantha. The extraction was carried out in the temperature range of 40-80 degrees C and the pressure range of 13.6-34.0 MPa with supercritical carbon dioxide. However, podophyllotoxin was not sufficiently extracted by pure supercritical carbon dioxide. Methanol was used as modifier to enhance the extraction yield of podophyllotoxin. As a result, SFE produced a higher recovery of podophyllotoxin than conventional 95% ethanol extraction.

High-dose therapy with peripheral blood stem cell (PBSC) support using an innovative mobilization regimen in patients with high-risk primary or chemoresponsive metastatic breast cancers

High-dose therapy followed by peripheral blood stem cell (PBSC) support was performed in 29 patients with primary high-risk (Group I) or chemoresponsive metastatic (Group II) breast cancer patients. Group I patients had received PBSC mobilization within 4 weeks of modified radical mastectomy. Group II patients had to achieve minimal residual disease (MRD) by induction chemotherapy before being considered eligible for PBSC mobilization and high-dose therapy. An innovative FE120C regimen (5-FU 600 mg/m2, i.v., day 1; epirubicin 120 mg/m2, i.v., day 1; cyclophosphamide 600 mg/m2, i.v., day 1) plus G-CSF (300 microg/day, subcutaneous injection for 9 days, from day 4 post-FE120C) was used to mobilize PBSCs. After high-dose CTCb (cyclophosphamide 6,000 mg/m2, thiothepa 500 mg/m2, carboplatin 800 mg/m2, in 4 days), patients received PBSC infusion and daily C-CSF 300 microg subcutaneous injection. There were 19 and 16 patients enrolled into Group I and Group II, respectively. Ten of the Group II patients had achieved minimal residual disease (MRD) after induction chemotherapy. The median numbers of mobilized total CD34 + cells for Group I and Group II patients were 27.3 (9.2 to 114.1) x 10(6)/kg and 17.1 (5.9 to 69.1) x 10(6)/kg respectively. The median time to neutrophil recovery (ANC > or = 500/microL) was 8 and 9 days in Group I and II, respectively. The median time to platelet recovery (> or = 50,000/microL) was 10 and 15 days in Group I and II, respectively. No major treatment-related toxicities were noted. In Group I, 13 out of 19 patients (68.4%; 43-87%, 95% C.I.) remained recurrence-free with a median follow-up of 31 months (6 + to 55 + months). In Group II, 3 out of 10 patients (30%; 7-65%, 95% C.I.) remained progression-free at 33 +, 35 +, 39 + months from induction therapy. We suggest that the FE120C plus G-CSF is an effective and innovative regimen for PBSC mobilization in breast cancer patients, and high-dose CTCb therapy with PBSC support is a safe and well-tolerated treatment modality.

Dopamine transporter density measured by [123I]beta-CIT single-photon emission computed tomography is normal in dopa-responsive dystonia

The clinical distinction between dopa-responsive dystonia (DRD) and juvenile Parkinson's disease JPD) can pose a diagnostic challenge. Both conditions are dopa responsive. However, long-term L-dopa benefit is very different between the two. The difference in the prognosis is due to presence or absence of nigral cell loss. In JPD, there is degenerative nigral cell loss, whereas there are enzymatic defects in dopamine synthesis without cell loss in DRD. Mutations have been found in the GTP cyclohydrolase I (GCH-I) and tyrosine hydroxylase genes in DRD. As the discovered mutations are multiple and more are expected to be found, it is difficult to confirm or exclude DRD by mutation studies. Measurement of cerebrospinal fluid (CSF) neopterin will detect DRD from mutations in the GCH-I gene but not from mutations in tyrosine hydroxylase. The dopamine transporter (DAT) is a protein in the dopaminergic nerve terminals. (1R)-2beta-Carbomethoxy-3beta-(4-[123I]iodophenyl)tropane ([123I]beta-CIT) is a ligand for the DAT, and it was shown to be a useful nuclear imaging marker for neurons that degenerate in Parkinson's disease (PD). As DRD was shown to have a normal DAT without nigral cell loss in a postmortem study, we predicted that the DAT measured in vivo by nuclear imaging will be normal in DRD and will differentiate DRD from JPD. Therefore, we performed [123I]beta-CIT single-photon emission computed tomography ([123I]beta-CIT SPECT) in clinically diagnosed DRD, PD, and JPD, and examined whether DAT imaging can differentiate DRD from PD and JPD. We then examined whether DAT imaging can provide a screening tool for molecular genetic studies, by studying mutations in the candidate gene GCH-I and measuring CSF neopterin. Five females (4 from two families, and 1 sporadic) were diagnosed as DRD based on early-onset foot dystonia and progressive parkinsonism beginning at ages 7 to 12. All patients were functioning normally on L-dopa 100 to 250 mg/day for up to 8 years. SPECT imaging was obtained after intravenous injection of [123I]beta-CIT; 15 healthy volunteers served as normal control, and 6 PD and 1 JPD as disease controls. [123I]beta-CIT striatal binding was normal in DRD, whereas it was markedly decreased in PD and JPD. Gene analysis showed a novel nonsense mutation in the GCH-I gene in one family. No mutation was found in the other family or in the sporadic case. CSF neopterin was markedly decreased in the 4 tested patients. [123I]beta-CIT SPECT is a sensitive method for probing the integrity of nigrostriatal dopaminergic nerve terminals. A normal striatal DAT in a parkinsonian patient is evidence for a nondegenerative cause of parkinsonism and differentiates DRD from JPD. Finding a new mutation in one family and failure to demonstrate mutations in the putative gene in other cases supports the usefulness of DAT imaging in diagnosing DRD.

Role of Rta in the translation of bicistronic BZLF1 of Epstein-Barr virus

The BZLF1 gene of Epstein-Barr virus (EBV), which encodes a transcription factor, Zta, is transcribed into monocistronic and bicistronic mRNAs from two different promoters during the immediate-early stage of the EBV lytic cycle. It is generally accepted that the Zta protein translated from the monocistronic mRNA profoundly influences the activation of the EBV lytic cycle. In this study, we constructed a plasmid, pCMV-RZLUC, which can transcribe a bicistronic mRNA consisting of BRLF1 and a BZLF1-luc fusion gene under latent conditions. P3HR1 cells transfected with this plasmid produce a luciferase activity which is approximately 17-fold higher than the activity exhibited by pRZLUC, a plasmid incapable of transcribing the bicistronic mRNA. Genetic analyses indicated that mutations in BRLF1 not only can decrease the translation of the fusion gene from the bicistronic mRNA but can also be complemented by a functional BRLF1 gene in cis. This observation implies that the product of BRLF1, Rta, is involved in the translation of the downstream gene. Results presented herein also demonstrate that these mutations cannot be complemented in trans with a plasmid overexpressing Rta, suggesting that the amount of Rta in the vicinity of the intercistronic region may be crucial for the translation. Furthermore, our results correspond to those of previous investigations indicating that the Zta protein can be translated from the bicistronic mRNA and that, similar to the translation of bicistronic ZLUC, mutations in BRLF1 also hinder the translation of Zta from the BRLF1-BZLF1 bicistronic mRNA. Translation of Zta from the bicistronic mRNA may play an essential role in the activation of the EBV lytic cycle.

Chromosomal abnormalities of a new nasopharyngeal carcinoma cell line (NPC-BM1) derived from a bone marrow metastatic lesion

An epithelial cell line, NPC-BM1, was established from a bone marrow biopsy of a female Taiwanese patient with nasopharyngeal carcinoma (NPC). Histopathology of the bone marrow biopsy and xenografts grown in severe combined immunodeficiency mice showed that the tumor was a nonkeratinizing, poorly differentiated carcinoma. NPC-BM1 cells grown as monolayers had a doubling time of 28.5 hours. Chromosome analysis showed that NPC-BM1 had the following features: 1) hypotetraploidy with a modal chromosome number of 87 (84-90); 2) numerically and structurally normal chromosomes 18; 3) numerical abnormalities without apparent structural alterations on chromosomes 14, 16, 17, 19, and 20; 4) ten structural abnormalities, t(1;9)(p11;q11), t(3;?;4)(p13;?;q13), add(4p),del(6p), i(8) [corrected] (q10),der(?)t(?;12),(?;p12),[corrected] add(21)(p11), del(X)(q24), add(X)(q22), and marker 1 (M1), in all metaphases examined, which were found to be present in two to five cell lines from primary NPC tumors reported previously; and 5) four other abnormalities, t(2;?;2)(p11.2;?;q21),t(11;22)(q11;q11),i(22)(q10), and marker 2 (M2), unique to this metastatic cell line. To the best of our knowledge, NPC-BM1 is the first NPC cell line derived from a distant metastatic site. Further evaluation of this cell line and additional metastatic NPC cell lines as well as primary NPC cell lines with respect to relations between the timing, karyotypic anomalies, and immunobiological characteristics in NPC progression and metastasis is warranted.

Twelve-nucleotide repeat polymorphism of D4 dopamine receptor gene in Chinese familial schizophrenic patients

BACKGROUND

Disturbances in dopaminergic transmission have been implicated in the etiology of schizophrenia. Catalano et al reported an association between delusional disorder and the number of a 12-nucleotide (bp) repeat sequence in the first exon of dopamine D4 receptor gene (DRD4), which indicated a possible role of this polymorphism in the pathogenesis of psychotic disorders.

METHODS

DNA of 42 Chinese controls, 50 sporadic schizophrenic patients, and 30 familial schizophrenic probands were collected. Genotype of the 12-bp repeat polymorphism of DRD4 was determined with polymerase chain reaction and agarose gel electrophoresis. Genotypic and allelic frequencies were compared among the three groups using the chi-square test.

RESULTS

Forty-three (86%) sporadic schizophrenic patients, 25 (83.3%) familial schizophrenic probands, and 35 (83.3%) controls were A1 (two 12-bp repeat) homozygotes. One (2.0%) sporadic schizophrenic and 1 familial schizophrenic patient were A2 (one 12-bp repeat) homozygotes. There was no significant difference in allelic and genotypic distributions among the three groups.

CONCLUSIONS

The present data do not support an association between schizophrenia and any specific allele of the 12-bp repeat polymorphism of DRD4. Significance of familial/sporadic division of schizophrenia cannot be supported regarding this repeat polymorphism.

Three new flavonoids and antiallergic, anti-inflammatory constituents from the heartwood of Dalbergia odorifera

Three new flavonoids, (3R)-4'-methoxy-2',3,7-trihydroxyisoflavanone (11), 7-methoxy-3,3',4',6-tetrahydroxyflavone (18), and 2',7-dihydroxy-4',5'-dimethoxyisoflavone (22), were isolated from the heartwood of Dalbergia odorifera T. Chen. (Leguminosae), together with twenty-two known compounds, (S)-4-methoxydalbergione (1), cearoin (2), medicarpin (3), formononetin (4), sativanone (5), 3-hydroxy-9-methoxy-coumestan (6), meliotocarpan A (7), isoliquiritigenin (8), stevein (9), liquiritigenin (10), 3',4',7-trihydroxyflavanone (12), butein (13), 3'-hydroxymelanettin (14), koparin (15), bowdichione (16), fisetin (17), melanettin (19), sulfuretin (20), 3'-hydroxydaidzein (21), 3'-O-methylviolanone (23), xenognosin B (24), and dalbergin (25). These flavonoids were evaluated in antiallergic and anti-inflammatory tests. The results showed that (S)-4-methoxydalbergione (1) and cearoin (2) exhibited antiallergic activity while (S)-4-methoxydalbergione (1), cearoin (2), butein (13), koparin (15), bowdichione (16), 3'-O-methylviolanone (23), and xenognosin B (24) showed significant anti-inflammatory activity.

Molecular cloning and characterization of fengycin synthetase gene fenB from Bacillus subtilis

A fengycin synthetase gene, fenB, has been cloned and sequenced. The protein (FenB) encoded by this gene has a predicted molecular mass of 143.6 kDa. This protein was overexpressed in Escherichia coli and was purified to near homogeneity by affinity chromatography. Experimental results indicated that the recombinant FenB has a substrate specificity toward isoleucine with an optimum temperature of 25 degrees C, an optimum pH of 4.5, a Km value of 922 microM, and a turnover number of 236 s(-1). FenB also consists of a thioesterase domain, suggesting that this protein may be involved in the activation of the last amino acid of fengycin.

A27L protein mediates vaccinia virus interaction with cell surface heparan sulfate

Vaccinia virus has a wide host range and infects mammalian cells of many different species. This suggests that the cell surface receptors for vaccinia virus are ubiquitously expressed and highly conserved. Alternatively, different receptors are used for vaccinia virus infection of different cell types. Here we report that vaccinia virus binds to heparan sulfate, a glycosaminoglycan (GAG) side chain of cell surface proteoglycans, during virus infection. Soluble heparin specifically inhibits vaccinia virus binding to cells, whereas other GAGs such as condroitin sulfate or dermantan sulfate have no effect. Heparin also blocks infections by cowpox virus, rabbitpox virus, myxoma virus, and Shope fibroma virus, suggesting that cell surface heparan sulfate could be a general mediator of the entry of poxviruses. The biochemical nature of the heparin-blocking effect was investigated. Heparin analogs that have acetyl groups instead of sulfate groups also abolish the inhibitory effect, suggesting that the negative charges on GAGs are important for virus infection. Furthermore, BSC40 cells treated with sodium chlorate to produce undersulfated GAGs are more refractory to vaccinia virus infection. Taken together, the data support the notion that cell surface heparan sulfate is important for vaccinia virus infection. Using heparin-Sepharose beads, we showed that vaccinia virus virions bind to heparin in vitro. In addition, we demonstrated that the recombinant A27L gene product binds to the heparin beads in vitro. This recombinant protein was further shown to bind to cells, and such interaction could be specifically inhibited by soluble heparin. All the data together indicated that A27L protein could be an attachment protein that mediates vaccinia virus binding to cell surface heparan sulfate during viral infection.

The presence of RNA splicing signals in the cDNA construct of the E2 gene of classical swine fever virus affected its expression

E2 is the major neutralizing antigen for classical swine fever virus (CSFV) infection. Previously, we have cloned and sequenced the E2 cDNA of Taiwan strain p97 by the reverse transcription-polymerase chain reaction (RT-PCR) method from CSFV-infected tissue. The presence of RNA splicing donor and acceptor sites were found in the cDNA sequence. In this study, transfection of E2 cDNA into mammalian cells resulted in the production of a spliced RNA. Site-directed mutagenesis of the donor and acceptor sites prevented the RNA splicing event and generated a full length transcript in COS7 cells. Although the spliced E2 transcript has not been reported in natural infection of CSFV, this study suggested that the potential splicing sites affected the E2 gene expression when the plasmid-based E2 gene was introduced into mammalian cells.

Sequence variations between two Epstein-Barr virus LMP 1 variants have no effect on the activation of NF-kappaB activity

Previously, we reported that the LMP 1 gene of Epstein-Barr virus (EBV) derived from nasopharyngeal carcinoma (NPC) tissues (i.e., NLMP 1 gene) was able to transform BALB/c3T3 cells. On the other hand, LMP 1 gene of B95-8 strain (i.e., BLMP 1 gene) was not able to transform these cells (Chen et aL, 1992). Further studies indicated that a 10-amino-acid deletion in the carboxyl terminus of NLMP 1 played an important role in transformation (Li et al., 1996). In this study, we tested if this 10-amino-acid deletion affected the induction of NF-kappaB activity by LMP 1. The long terminal repeat of the human immunodeficiency virus type 1 (HIV-1 LTR) contained two copies of NF-kappaB sites and was used to construct the Luc gene-based reporter plasmid, p kappaB-Luc. Plasmid p kappaB-Luc was co-transfected with plasmids containing the NLMP 1 gene, BLMP 1 gene, and their chimeric or deletion constructs, respectively, into C-33A and BALB/c3T3 cells. The activation was then measured by the luciferase activity. Results showed that the full-length proteins induced a similar level of NF-kappaB activity, the two 3' mutants (R15delta and D4delta) still induced a relatively high level of activity, and the two 5' deletion mutants (delta3058 and delta3243) of NLMP 1 gene did not show any significant activation in C-33A cells. However, none of these LMP 1 proteins induced NF-kappaB activity in BALB/c3T3 cells. Using subcellular fractionation analysis and an immunocytostaining method, the truncated proteins of delta3058 and delta3243 were detected in the cytoplasm of the cells whereas the full-length NLMP 1 protein was located at the cytoplasmic membrane. Stable BALB/c3T3 cell clones that expressed both truncated proteins were established and then their ability to induce tumors in nude mice was examined. Data showed that both truncated NLMP 1 proteins still maintained partial transformation activity. Our results suggested that there was no direct correlation between NF-kappaB activation and transformation activity of LMP 1 in BALB/c3T3 cell transformation and that the amino-terminal membrane-spanning domain was important for maintaining both functions of LMP 1.

Microsurgical reversal of tubal sterilization: a report on 1,118 cases

OBJECTIVE

To review and evaluate a series of patients who underwent microsurgical anastomosis of previously sterilized fallopian tubes.

DESIGN

Retrospective clinical study.

SETTING

Tertiary care academic center.

PATIENT(S)

In the 134-month span from January 1980 to February 1991, 1,118 women were evaluated for microsurgical reversal of previous tubal sterilization.

MAIN OUTCOME MEASURE(S)

Clinical characteristics of patients, pregnancy rates (PRs), and factors influencing the outcome.

RESULT(S)

Of 1,118 patients, 633 (56.6%) had been sterilized by laparoscopic cautery. Loss of children was a leading reason for requesting tubal reversal. The mean interval between tubal sterilization and reversal was 51.9 months. Nine hundred twenty-two (82.5%) patients were followed up for > 5 years. The overall PR after microsurgical tubal anastomosis was 54.8% (505 of 922) with a delivery rate of 72.5% (366 of 505), and the estimated anatomical success rate was 88.2% (814 of 922). There was no statistically significant difference in the PR or in the interval from tubal reversal to conception among the different operative procedure groups. In addition, no statistically significant difference in the PR was observed regardless of the postoperative tubal length. However, the interval from operation to pregnancy decreased significantly as the postoperative tubal length increased. The pregnant patients (n = 505) were younger and had a longer postoperative tube than the nonpregnant patients (n = 417); these differences were statistically significant.

CONCLUSION(S)

The pregnancy rate after microsurgical reversal of tubal sterilization was not significantly correlated with the method and duration of sterilization, the operative procedure, or the postoperative tubal length.

Synthetic osteochondral replacement of the femoral articular surface

We have studied damage to the tibial articular surface after replacement of the femoral surface in dogs. We inserted pairs of implants made of alumina, titanium and polyvinyl alcohol (PVA) hydrogel on titanium fibre mesh into the femoral condyles. The two hard materials caused marked pathological changes in the articular cartilage and menisci, but the hydrogel composite replacement caused minimal damage. The composite osteochondral device became rapidly attached to host bone by ingrowth into the supporting mesh. We discuss the clinical implications of the possible use of this material in articular resurfacing and joint replacement.

The immunotherapy during in vitro fertilization and embryo transfer cycles in infertile patients with endometriosis

OBJECTIVE

To investigate if the immunotherapy with corticosteroids would improve the pregnancy rate in infertile patients with endometriosis who undergo in vitro fertilization and embryo transfer (IVF-ET).

METHODS

Forty-two infertile patients with endometriosis plus tubal factor and 87 pure tubal infertility patients who underwent IVF-ET in our unit were allocated randomly to the corticosteroid treatment group and the control group.

RESULTS

The prevalence of autoantibodies (antinuclear antibody, lupus anticoagulant, anticardiolipin antibody, rheumatoid factor) was elevated significantly in patients with endometriosis plus tubal factor compared with pure tubal infertility patients (38.1% vs 2.3%). Twenty-one patients with endometriosis plus tubal factor underwent 54 cycles of IVF-ET, receiving corticosteroids. Forty-three patients with pure tubal factor underwent 81 cycles of IVF-ET, receiving corticosteroids. Twenty-one patients with endometriosis plus tubal factor who underwent 57 cycles of IVF-ET and 44 patients with pure tubal factor who underwent 84 cycles of IVF-ET served as controls, not receiving corticosteroids. In patients with endometriosis plus tubal factor, there was a significantly higher clinical pregnancy rate per cycle in the treatment group, with 42.6% (23/54) compared with 22.8% (13/57) in the control group but no differences between 2 groups in spontaneous abortion rate (21.7% vs 15.4%) and multiple pregnancy rate (17.4% vs 15.4%). In patients with pure tubal infertility, there were no significant differences between the treatment group and control group in clinical pregnancy rate (40.7% vs 34.5%), spontaneous abortion rate (12.1% vs 10.3%) or multiple pregnancy rate (18.2% vs 10.3%). In the endometriosis plus tubal infertility group with autoantibodies, the clinical pregnancy rate per cycle was significantly higher in the treatment group at 40.9% compared with 14.8% in the control group. In endometriosis plus tubal infertility group without autoantibodies, there was no significant difference between 2 groups with respect to the clinical pregnancy rate per cycle (43.8% vs 30.0%).

CONCLUSIONS

This study suggests that immunotherapy with corticosteroids could improve the clinical pregnancy rate in endometriosis patients undergoing IVF-ET and may be more effective in patients with positive autoantibodies.

Microvillus inclusion disease in two Korean infants

We report two cases of microvillus inclusion disease and these are the first cases in Korea. The two babies (one baby had a sibling who died of diarrhea in the neonatal period) had excreted their stools up to 200 ml/kg per day since several days after birth. Workup's included extensive infectious, immunologic, hormonal and rheumatologic studies, all of which were negative or normal. Diagnosis rested on the ultrastructural finding of intracytoplasmic inclusions that contained intact microvilli on electron microscopy. We tried somatostatin analogue (octreotide, 4 micrograms/kg/day), cholestyramine (up to 4g t.i.d.), steroid (prednisone, 2 mg/kg/day) and intravenous epidermal growth factor (100 ng/kg/hr for 2 weeks), but there was mild improvement with cholestyramine (decrease stool volume) and epidermal growth factor (increase the number of microvilli per cell) but no improvement was noted with the other treatments. Although it is a rare disorder and the prognosis of microvillus inclusion disease is poor, it must be considered if an infant has chronic secretory diarrhea.

Histologic comparison of tibial articular surfaces against rigid materials and artificial articular cartilage

After endoprosthetic replacement of the femoral head, marked pathologic changes of the acetabulum, such as penetration and ulceration, often occur. These changes are caused by the rigid material surface properties of the prosthesis and the lack of damping effects. In this study, we compared the time-dependent changes of tibial articular surfaces with three kinds of femoral implant under loading conditions in dogs. Marked pathologic changes of the menisci and tibial articular cartilage were observed from 8 weeks after implantation with hard material implants, whereas the tibial joint surface against an artificial articular cartilage was still intact 24 weeks postoperatively. These results showed clearly that marked pathologic changes of the articular cartilage against rigid materials occurred and were caused by the surface properties of the counterfaces and high friction coefficients of ceramic and metal materials used.