Dehydroepiandrosterone and melatonin prevent Bacillus anthracis lethal toxin-induced TNF production in macrophages

The lethal toxin of Bacillus anthracis, which is composed of two separate proteinaceous exotoxins, namely protective antigen and lethal factor, is central to the pathogenesis of anthrax. Low levels of this toxin are known to induce release of cytokines such as tumor necrosis factor alpha (TNF-alpha). In the present study we investigated the effect of dehydroepiandrosterone (DHEA), melatonin (MLT), or DHEA + MLT on production of lethal toxin-induced TNF-alpha in mouse peritoneal macrophages. We found that treatment with DHEA significantly inhibited the TNF-alpha production caused by anthrax lethal toxin. Exposure of MLT to anthrax lethal toxin-treated macrophages also decreased the release of TNF-alpha to the extracellular medium as compared to the control. However, combined use of DHEA and MLT also inhibited TNF-alpha release, but not more than single therapies. These results suggest that DHEA and MLT may have a therapeutic role in reducing the increased cytokine production induced by anthrax lethal toxin.

A single point mutation in HIV-1 V3 loop alters the immunogenic properties of rgp120

The results of the study presented in this report show that clones of env derived from genetically divergent HIV-1 field isolates fall into two major subsets based on the predicted secondary structure of the V3 region in gp120. One subset exemplified by the clones A-UG06c, B-RT3.12 and C-UG045 is predicted to assume a beta-turn conformation in the V3 loop and comprises the GPGX residues. The other subset exemplified by the clones D-UG23c and D-UG042 (GXGX) are deficient in the expression of the beta-turn in the loop. Since secondary conformations are highly likely to confer antigenic properties in a protein backbone at least for B cells, we have used nucleic acid immunization to test the effect of the beta-turn deficiency on the immunogenic potential of rgp120 encoded in these field isolates. As hypothesized, inoculation of BALB/c mice with the env plasmid encoding the beta-turn expressing rgp120 molecules resulted in the development of a vigorous antibody response to the homologous V3 loop peptides. In contrast, immunization with an rgp120 clone deficient in the beta-turn in the V3 loop showed no evidence of antibody development to the V3 loop. Instead, the latter clones triggered T cell proliferative responses and markedly increased the level of IL-2 and IFN-gamma production by T cells. Significantly, reconstitution of the beta-turn conformation by site-directed mutagenesis of a single V3 loop residue yielded rgp120 molecules which restored antibody production while diminishing the cell-mediated immune (CMI) responses to the V3 residue. These observations demonstrate the marked impact of a single amino acid substitution on the immunogenic properties of V3 region in gp120 encoded by divergent HIV-1 field isolates.

Intracellular calcium antagonist protects cultured peritoneal macrophages against anthrax lethal toxin-induced cytotoxicity

The lethal toxin of Bacillus anthracis is central to the pathogenesis of anthrax. Using primary cultures of mouse peritoneal macrophages, we have demonstrated that intracellular calcium release inhibitors protect against anthrax lethal toxin-induced cytotoxicity. The cytolytic effect of anthrax lethal toxin was markedly reduced by dantrolene, an inhibitor of calcium release from intracellular calcium stores. Pretreatment of macrophages with cyclosporin A, which has been shown to be a potent inhibitor of calcium release from mitochondria, also protected cells against cytotoxicity. These results indicate that calcium release from intracellular store may be an essential step for the propagation of anthrax lethal toxin-induced cell damage in macrophages. Thus our findings suggest that dantrolene, cyclosporin A, and possibly other drugs affecting intracellular calcium pools might be effectively preventing the toxicity from anthrax lethal toxin.

Hypersensitivity pneumonitis caused by Fusarium napiforme in a home environment

BACKGROUND

We report a case of hypersensitivity pneumonitis (HP) in a 17-year-old male student caused by Fusarium napiforme found in his home environment.

METHODS

The patient was diagnosed according to history, chest radiograph, spirometry, high-resolution chest CT, and transbronchial lung biopsy. To identify the causative agent, cultured aeromolds were collected by the open-plate method. From the main fungi cultured, fungal antigens were prepared, and immunoblot analysis with the patient's serum and each fungal antigen was performed.

RESULTS

Five fungal species were isolated from the patient's home. Immunoblotting analysis with the patient's serum demonstrated more than 10 IgG-binding fractions to F. napiforme extract only, while little binding was noted with the other fungal antigens.

CONCLUSIONS

We should be aware that HP may be caused by F. napiforme in the home environment.

Pharmacokinetics of theophylline and caffeine after intravenous administration of aminophylline to premature neonates in Korea

Theophylline has been widely used to treat apnea of premature neonates. The purpose of this study was to compare the pharmacokinetic parameters of theophylline and caffeine after intravenous administration of aminophylline to seven Korean low-birthweight neonates with apnea to those in other countries. The serum concentrations of theophylline and caffeine were measured simultaneously by high-performance liquid-chromatography (HPLC). The mean (+/- S.E.M.) birth weight and gestational period were 1190 +/- 253 g and 31.5 +/- 1.99 weeks, respectively. The mean (+/- S.E.M.) theophylline maintenance dosage was 1.28 +/- 0.15 mg/kg (given as equivalent aminophylline solution) every six hours. The mean (+/- S.E.M.) volume of distribution, 0.937 +/- 0.232 l/kg, elimination rate constant, 0.0249 +/- 0.0095/h, elimination half-life, 32.1 +/- 12.1 h, and total body clearance, 21.7 +/- 6.18 ml/h/kg, of theophylline in Korean premature neonates were comparable to the values of neonates in other countries. For caffeine, the mean (+/- S.E.M.) elimination half-life was 95.1 +/- 25.4 h and the elimination rate constant was 0.0079 +/- 0.0024/h. The mean (+/- S.E.M.) serum concentrations of theophylline and caffeine on the sixth day after aminophylline infusion were 10.4 +/- 2.28 microg/ml (range, 6.38-13.4 microg/ml) and 2.94 +/- 0.98 microg/ml (range, 1.80-4.44 microg/ml), respectively. The mean (+/- S.E.M.) caffeine to theophylline concentration ratio on the day after discontinuation of aminophylline infusion was 0.71 +/- 0.23 (range, 0.39-1.03).

Carotid artery stenting in patients with symptomatic coronary artery disease

Carotid artery stenting has been accepted as a potential alternative to carotid endarterectomy in patients with significant carotid artery stenosis. The objective of this study was to evaluate the feasibility, safety and long-term outcome of percutaneous stenting of carotid artery stenosis in patients with coexisting symptomatic coronary disease. Between May 1996 and May 1999, we performed carotid artery stenting at 48 lesions in 36 patients with carotid stenosis of 60% and symptomatic coronary artery stenosis. Twenty-one patients (58%) had neurologic symptoms. Carotid stenting was performed in 43 internal, 2 external and 3 common carotid lesions. We used Wallstent in 46 lesions, Palmaz stent in 2 lesions and Microstent II in 1 lesion. Staged or combined coronary intervention was performed in 18 patients (50%) and staged coronary artery bypass surgery was performed in 6 patients (17%). In the other 12 patients (33%), medical treatments were performed. Carotid stenting was successful in all lesions. Simultaneous bilateral carotid stenting was performed in 11 patients (31%). One major and 1 minor stroke developed during the procedure. There were no deaths during the procedures and within 30 days post-procedure. During the follow-up of 14 +/- 7 (3 to 40) months, there were no deaths or neurological events. On follow-up (6 +/- 1 months) angiography and/or duplex sonography of 44 eligible lesions in 32 patients, there were 2 cases of asymptomatic restenosis (4.5%) which developed in Palmaz stents implanted at the external carotid artery and the common carotid artery, respectively. In conclusion, carotid artery stenting in patients with coexistent carotid and coronary artery disease is feasible, safe and shows favorable follow-up outcomes.

Radiation-induced lung disease and the impact of radiation methods on imaging features

Although radiologic findings in radiation-induced lung disease are well described in the literature, the influence exerted on these findings by different radiation methods is not well understood. Radiation treatment of non-small cell lung cancer varies depending on the location and extent of disease. Irradiation with oblique beam angles results in unusual distribution of radiation-induced lung disease. Small cell lung cancer is treated with irradiation concurrent with or following chemotherapy, and portal arrangements are controversial. In breast cancer, use of tangential beam portals may induce radiation pneumonitis or fibrosis at the peripheral lung anterolaterally. Use of supraclavicular portals may produce lesions in the lung apex that appear similar to pulmonary tuberculosis. In esophageal cancer, radiation portals with a 5-6-cm margin above and below the tumor are generally recommended, and computed tomography (CT) frequently demonstrates radiation-related lung damage adjacent to the mediastinum. In mediastinal tumors, the mantle field includes all the major lymph node regions above the diaphragm. Radiation pneumonitis varies from minimal to extremely marked change in the paramediastinal areas and in both apices. CT is more sensitive to radiation-induced lung disease than chest radiography and demonstrates related changes earlier. Furthermore, it more clearly depicts the precise distribution and pattern of disease. Familiarity with the imaging findings in radiation-induced lung disease produced by different radiation methods will help radiologists interpret abnormalities seen at chest radiography and CT in affected patients.

Saccharomyces cerevisiae checkpoint genes MEC1, RAD17 and RAD24 are required for normal meiotic recombination partner choice

Checkpoint gene function prevents meiotic progression when recombination is blocked by mutations in the recA homologue DMC1. Bypass of dmc1 arrest by mutation of the DNA damage checkpoint genes MEC1, RAD17, or RAD24 results in a dramatic loss of spore viability, suggesting that these genes play an important role in monitoring the progression of recombination. We show here that the role of mitotic checkpoint genes in meiosis is not limited to maintaining arrest in abnormal meioses; mec1-1, rad24, and rad17 single mutants have additional meiotic defects. All three mutants display Zip1 polycomplexes in two- to threefold more nuclei than observed in wild-type controls, suggesting that synapsis may be aberrant. Additionally, all three mutants exhibit elevated levels of ectopic recombination in a novel physical assay. rad17 mutants also alter the fraction of recombination events that are accompanied by an exchange of flanking markers. Crossovers are associated with up to 90% of recombination events for one pair of alleles in rad17, as compared with 65% in wild type. Meiotic progression is not required to allow ectopic recombination in rad17 mutants, as it still occurs at elevated levels in ndt80 mutants that arrest in prophase regardless of checkpoint signaling. These observations support the suggestion that MEC1, RAD17, and RAD24, in addition to their proposed monitoring function, act to promote normal meiotic recombination.

Germline mutations in the EXT1 and EXT2 genes in Korean patients with hereditary multiple exostoses

Hereditary multiple exostoses (EXT) is an autosomal dominantly inherited disease characterized by the formation of cartilage-capped prominences (exostoses) that develop from the juxtaepiphyseal regions of the long bones. Recently, EXT1 and EXT2 genes were cloned and germline mutations of EXT1 and EXT2 were identified in EXT families. In this study, we performed a mutational analysis of EXT1 and EXT2 genes in eight unrelated Korean EXT families by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis followed by direct DNA sequencing. As a result, we were able to identify one family (SNU-OC3) with the EXT1 mutation and another family (SNU-OC15) with the EXT2 mutation. The EXT1 mutation was a 10-bp deletion at the 3' end of exon 5 (CTAATTTAGg) including the splice site of this exon. The EXT2 mutation identified in the SNU-OC15 family was a missense mutation at codon 85 of exon 2 (TGC-->CGC), resulting in an amino acid change from cysteine to arginine. This missense mutation cosegregated with the disease phenotype in this family, suggesting that it is the disease-causing mutation. These two mutations identified in EXT1 and EXT2 are novel ones.

Prognostic factors in 2230 Korean colorectal cancer patients: analysis of consecutively operated cases

To define the prognostic factors in Korean colorectal cancer patients, univariate and multivariate analysis were performed on data from 2230 consecutive patients who underwent resection for colorectal cancer at the Seoul National University Hospital. The prognostic variables used for the analysis included patient's age, gender, bowel obstruction, bleeding, symptom duration, preoperative leukocyte count, preoperative serum carcinoembryonic antigen (CEA) level, Dukes' stage, tumor location, tumor size, depth of bowel wall invasion, number of lymph node metastases, histologic differentiation, and gross morphology of tumor. The overall 5-year survival rate was 62%. In the univariate analysis, all the factors except sex, symptom duration, and tumor size were associated with prognosis. Among the factors significant in the univariate analysis, Dukes' stage (p < 0.001), number of lymph node metastasis (p < 0.001), CEA level (p < 0.001), tumor location (p = 0.003), gross morphology of tumor (p = 0.017), and depth of bowel wall invasion (p = 0.031) were significant in the multivariate analysis. Several differences in prognostic factors between colon cancer and rectal cancer were observed. In the multivariate analysis, gross tumor morphology was significant only for colon cancer, and histologic differentiation was significant only for rectal cancer. Lymph node metastasis was an independent prognostic variable for both colon and rectal cancer, but its significance was more prominent for rectal cancer. Although Dukes' stage is the most reliable prognostic predictor, this study shows that other factors (preoperative CEA level, gross morphology of tumor, location of tumor, nodal status) also provide important information for the outcome of the patient.

The imbalance between coagulation and fibrinolysis is related to the severity of the illness and the prognosis in sepsis

OBJECTIVES

The coagulation and fibrinolytic system appears to be activated by the septic process independently, leading to the syndrome of disseminated intravascular coagulation (DIC). In this study, we investigated the changes within the hemostatic system related to the severity of the illness and the prognosis in patients with sepsis.

METHODS

Plasma thrombin-antithrombin III (TAT) and plasmin-alpha 2-antiplasmin (PAP) complexes were measured using ELISA methods in 32 patients with sepsis and 20 controls and were analyzed according to the APACHE III scores and survival of the patients.

RESULTS

Plasma TAT and PAP in patients with sepsis were significantly higher than controls. Nonsurvivors showed greater levels of TAT (21.7 +/- 22.3 ng/mL) and lower levels of PAP (628.4 +/- 378.1 ng/mL) than survivors (TAT: 11.1 +/- 11.2 ng/mL; PAP: 857.1 +/- 364.1 ng/mL). The imbalance between coagulation and fibrinolysis described as TAT/PAP ratio was closely related with APACHE III scores in patients with sepsis (r = 0.47) and the TAT/PAP ratio in nonsurvivors was significantly higher compared with survivors (34.4 +/- 21.4 vs. 14.4 +/- 13.8).

CONCLUSION

In sepsis, both coagulation and the fibrinolysis system are activated and the imbalance between coagulation and fibrinolysis predisposes to the hypercoagulation state and is closely related to the severity of the disease and the prognosis.

Suspected hereditary nonpolyposis colorectal cancer: International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer (ICG-HNPCC) criteria and results of genetic diagnosis

PURPOSE

The aim of this study was to determine the frequency of mutations in the mismatch repair genes in families suspected of having hereditary nonpolyposis colorectal cancer.

METHODS

We devised two criteria for families suspected of having hereditary nonpolyposis colorectal cancer (Criteria I and II). Criteria I consist of at least two first-degree relatives affected with colorectal cancer with at least one of the following: development of multiple colorectal tumors including adenomatous polyp, at least one colorectal cancer case diagnosed before the age of 50, and occurrence of a hereditary nonpolyposis colorectal cancer extracolonic cancer (endometrium, urinary tract, small intestine, stomach, hepatobiliary system, or ovary) in family members. Criteria II consist of one colorectal cancer patient with at least one of the following: early age of onset (<40 years); endometrial, urinary tract, or small intestine cancer in the index patient or a sibling (one aged <50 years); and two siblings with other integral hereditary nonpolyposis colorectal cancer extracolonic cancers (one aged <50 years). A questionnaire was mailed to members of the International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer to determine the mutation detection rate in mismatch repair genes from the families fulfilling these criteria. For comparison the mutation detection rate for families fulfilling the Amsterdam hereditary nonpolyposis colorectal cancer criteria in each institution was also obtained.

RESULTS

Data were obtained from eight different institutions (in 7 different countries). In a total of 123 patients from 123 families (67 families fulfilling Criteria I and 56 families fulfilling Criteria II), genetic testing for germline mismatch repair gene variants was performed. Germline mutations of the hMLH1 or hMSH2 genes were identified in 24 families (20 percent). Of these, the mutation detection rate for families fulfilling Criteria I was 28 percent (19/67). The mutation detection rate for families fulfilling Criteria II was 9 percent (5/56). In these eight institutions, the overall mutation detection rate for families fulfilling the Amsterdam hereditary nonpolyposis colorectal cancer criteria was 50 percent (77/154).

CONCLUSION

The Criteria I for suspected hereditary nonpolyposis colorectal cancer have the advantages that they can be applied to nuclear families and they can include extracolonic cancers. The results of this study suggest that families fulfilling Criteria I should be offered genetic testing. The relatively low mutation detection rate in those families fulfilling Criteria II suggests that, using current techniques, genetic testing in these families is not practical.

Quantitation of emphysema with three-dimensional CT densitometry: comparison with two-dimensional analysis, visual emphysema scores, and pulmonary function test results

PURPOSE

To compare lung densitometric measurements that use a three-dimensional (3D) reconstruction of the lungs with those obtained from analysis of two-dimensional (2D) computed tomographic (CT) images, visual emphysema scores, and data from pulmonary function tests.

MATERIALS AND METHODS

Thoracic helical CT scans were obtained in 60 adult patients (35 with no visual evidence of emphysema and 25 with emphysema). The lungs were reconstructed as a 3D model on a commercial workstation, with a threshold of -600 HU. By analysis of histograms, the proportions of lung volumes with attenuation values below -950, -910, and -900 HU were measured, in addition to mean lung attenuation. These values were compared with lung densitometric results obtained from 2D CT images, visual emphysema scores, and data from pulmonary function tests.

RESULTS

Quantitation of emphysema with 3D reconstruction was efficient and accurate. Correlation was good among densitometric quantitation with 3D analysis, that obtained with 2D analysis (r = 0.98-0.99), and visual scoring (r = 0.74-0.82). Correlation was reasonable between 3D densitometric quantitation and the diffusing capacity of the lungs for carbon monoxide (DLCO) (r = -0.57 to -0.64), total lung capacity (r = 0.62-0.71), forced expiratory volume in 1 second (FEV1) (r = -0.57 to -0.60), and the ratio of FEV1 to forced vital capacity (FVC) (r = -0.75 to -0.82). The visual CT quantitation of emphysema correlated best with DLCO (r = -0.82) and FEV1/FVC (r = -0.89).

CONCLUSION

Lung densitometry with 3D reconstruction of helical CT data is a fast and accurate method for quantifying emphysema.

Cell cycle arrest mediated by hepatitis delta antigen

Hepatitis delta antigen (HDAg) is the only viral-encoded protein of the hepatitis delta virus (HDV). This protein has been extensively characterized with respect to its biochemical and functional properties. However, the molecular mechanism responsible for persistent HDV infection is not yet clear. Previously, we reported that overexpression of HDAg protects insect cells from baculovirus-induced cytolysis [Hwang, S.B. Park, K.-J. and Kim, Y.S. (1998) Biochem. Biophys. Res. Commun. 244, 652-658]. Here we report that HDAg mediates cell cycle arrest when overexpressed in recombinant baculovirus-infected insect cells. Flow cytometry analysis has shown that HDAg expression in Spodoptera frugiperda cells causes an accumulation of substantial amounts of polyploid DNA in the absence of cell division. This phenomenon may be partly responsible for the persistent infection of chronic HDV patients.

Experience of 1446 rectal cancer patients in Korea and analysis of prognostic factors

In order to investigate the changing pattern of rectal cancers in Korea and to identify prognostic factors, we investigated the case histories of 1446 rectal cancer patients who had received surgical treatment. During the study period there were trends toward a decrease in the ratio of rectal cancer to colon cancer, earlier detection (more Dukes' stages A and B and fewer C), a decrease in the number of abdominoperineal resections, and an increase in the number of sphincter-preserving operations. Univariate analysis of prognostic factors showed that gender, obstruction symptoms, preoperative serum carcinoembryonic antigen (CEA) level, tumor size, depth of bowel wall invasion, lymph node metastases (presence and number), tumor differentiation, operative method, and date of operation were significant, but age, symptom duration, and tumor location were not. The use of sphincter-saving operations did not adversely affect the clinical outcome. Multivariate analysis showed lymph node metastasis factor to be the most significant factor (P < 0.001); the depth of bowel wall invasion, differentiation, CEA level, and date of operation were also significant (0.001 < P < 0.05). This study shows that although anatomical extent of disease (depth of invasion and lymph node metastasis) is the most reliable prognostic predictor in rectal cancer, other factors such as preoperative CEA level and tumor differentiation also provide important information on the outcome and use of an anal-preserving operation does not adversely affect the patient survival.

Germline mutations of the APC gene in Korean familial adenomatous polyposis patients

We extensively analyzed genomic DNA and messenger RNA (mRNA) from 62 unrelated Korean patients with familial adenomatous polyposis (FAP) for identification of germline adenomatous polyposis coli (APC) gene mutations. We adopted both single-strand conformation polymorphism (SSCP) analysis and a method of analysis involving the reverse transcription-polymerase chain reaction (RT-PCR) followed by a protein truncation test (PTT). DNA sequencing confirmed all alterations represented by aberrant bands. Germline mutations were identified in 38 patients (61%). Nineteen of the detected mutations were presumed to be novel, thus emphasizing the heterogeneity of the mutational spectrum in Korean FAP patients. In the initial 48 patients, SSCP analysis was followed by PTT for those patients for whom no detectable mutations were found by SSCP. Using this combined approach, we identified germline APC gene mutations in 29 of the 48 FAP patients (60%), including 6 patients in whom SSCP analysis failed to distinguish the mutant allele. In the 14 later patients, we identified truncating mutations in 9 patients (64%) using PTT only. Our results confirm that the mutation detection rate with PTT was superior to that with SSCP, and suggest that PTT would be a more practical screening method to detect germline mutations of the APC gene in FAP patients.

A novel parvovirus isolated from Manchurian chipmunks

A novel parvovirus was identified in Manchurian chipmunks inhabiting Korea. Hepatitis B surface antigen (HBsAg) was detected in sera from 4 animals among 62 apparently healthy chipmunks. Electron microscopic examination of the HBsAg-positive sera revealed virus-like spherical particles 20-22 nm in diameter. Extraction of nucleic acid under annealing conditions from the serum samples containing virus-like particles yielded a single species of DNA molecule with the electrophoretic mobility of 5.6-kb double-stranded DNA. Four overlapping clones that encompassed almost the full-length viral genome, except both ends, were obtained. By sequencing these clones, we determined the sequence of 5097 nucleotides of the viral DNA. Two open reading frames were identified, with the left side open reading frame encoding a putative nonstructural protein and the right side open reading frame encoding a putative capsid protein. The nucleotide and amino acid sequences showed significant homology to parvovirus B19 and simian parvovirus, but showed little homology to other mammalian autonomous parvoviruses or adeno-associated viruses. These observations indicate that the virus isolated from Manchurian chipmunks is a novel parvovirus and may be a potentially useful animal model of human B19 infection as a new member of the Erythrovirus genus of the Parvoviridae.

Expression of inducible nitric oxide synthase in the brains of scrapie-infected mice

The neuronal cell damage caused by inducible nitric oxide synthase (iNOS) in brain has been reported to be associated, at least in part, with many neurodegenerative diseases including Alzheimer's disease. We recently observed vacuolation and astrocytosis in the brains of ME7 scrapie strain-infected C57BL mice. To investigate if these phenomena might have a relationship to iNOS, the level of iNOS expression was measured immunohistochemically and molecular biologically in the brains of scrapie-infected C57BL mice. The number and size of astrocytes were increased and immunoreactivity of glial fibrillary acidic protein (GFAP) was significantly enhanced. iNOS immunoreactivity was observed in the astrocytes of the scrapie-infected group, but not in the control group. iNOS mRNA levels were increased in scrapie-infected mice compared to the levels in non-infected mice of the same age. Our results suggest that iNOS induction in reactive astrocytes is a part of the neurodegenerative mechanisms in scrapie infection.

Pharmacokinetic and pharmacodynamic changes of azosemide after intravenous and oral administration of azosemide to uranyl nitrate-induced acute renal failure rats

The pharmacokinetic and pharmacodynamic differences of azosemide were investigated after intravenous (i.v.) and oral administration of azosemide, 10 mg kg-1, to the control and uranyl nitrate-induced acute renal failure (U-ARF) rats. After IV administration, the plasma concentrations of azosemide were significantly higher in the U-ARF rats and this resulted in a significant increase in AUC (2520 versus 3680 micrograms min mL-1) and significant decrease in Cl (3.96 versus 2.72 mL min-1 kg-1) of azosemide. The significant decrease in Cl in the U-ARF rats was due to the significant decrease in Clr of azosemide (1.55 versus 0.00913 mL min-1 kg-1) due to the decrease in kidney function in the U-ARF rats. After IV administration, the urine output (38.5 versus 8.45 mL 100 g-1 body weight) and urinary excretion of sodium (4.60 versus 0.420 mmol 100 g-1 body weight) decreased significantly in the U-ARF rats. After oral administration, the AUC0-8 h of azosemide decreased significantly (215 versus 135 micrograms min mL-1) in the U-ARF rats possibly due to the decreased GI absorption of azosemide. After oral administration, the 24-h urine output decreased considerably (16.1 versus 11.2 mL 100 g-1 body weight, p < 0.098) and the 24-h urinary excretion of sodium (1.74 versus 0.777 mmol 100 g-1 body weight) decreased significantly in the U-ARF rats. The i.v. and oral doses of azosemide needed to be modified in the acute renal failure patients if the present rat data could be extrapolated to humans.

Overexpression of hepatitis delta antigen protects insect cells from baculovirus-induced cytolysis

Hepatitis delta virus (HDV) is a human pathogen causing fulminant hepatitis and liver cirrhosis. HDV has a circular single-stranded RNA genome, which encodes only a single protein, hepatitis delta antigen (HDAg), from the antigenomic strand. Although the functional roles of HDAg have been extensively studied, the molecular mechanism of persistent infection and pathogenesis of HDV are not yet understood. Here we report that overexpressed HDAg protects cells from death in baculovirus-infected insect cells. Using both wild-type and recombinant baculovirus-infected insect cells, we have demonstrated that HDAg inhibited wild-type baculovirus-induced cytolysis and thus extended the survival of virus-infected insect cells. By deletion analysis, we show that N-terminal 25 amino acids are essential for this function. From these data, we suggest that HDAg may play a major role in persistent infection of HDV.

Pulmonary asbestosis: radiologic-pathologic brief report

Pulmonary asbestosis is defined as bilateral diffuse interstitial fibrosis of the lungs caused by exposure to asbestos. Many occupations are at risk for asbestos exposure, particularly in the mining, milling, manufacturing, construction, shipbuilding, and automotive industries. Therefore, the prevalence of asbestosis should be fairly widespread. The diagnosis of asbestosis can be made on either clinical or pathological grounds. We recently encountered one case of asbestosis which was confirmed histologically. On HRCT, there was ground-glass opacity with irregular linear shadows, subpleural curvilinear lines and parenchymal bands. Neither plaque nor calcification were noted. The histologic findings observed on open-lung biopsy specimen were well in accord with those in HRCT. Many asbestos-coated bodies were present along with black dust.

Effects of the rate and composition of fluid replacement on the pharmacokinetics and pharmacodynamics of intravenous azosemide

The effects of differences in the rate and composition of intravenous fluid replacement for urine loss on the pharmacokinetics and pharmacodynamics of azosemide were evaluated using rabbit as the animal model. Each rabbit received a 4h constant intravenous infusion of 1 mg kg-1 azosemide with 0% replacement (treatment I, n = 4), 50% replacement (treatment II, n = 5), and 100% replacement (treatment III, n = 5) with lactated Ringer's solution, as well as with 100% replacement with 5% dextrose in water (D-5-W, treatment IV; n = 5). Renal clearance and urinary excretion rate of the drug in treatment III were considerably higher than those in treatments I, II, and IV. In spite of the similarities in kinetic properties, diuretic and/or natriuretic effects of azosemide were markedly different among the four treatments. For example, the mean 8 h urine output values were 98.2, 178, 733, and 237 mL for treatments I-IV, respectively, and the corresponding values for sodium excretion were 11.1, 19.4, 76.4, and 14.2 mmol, and for chloride 13.4, 23.8, 78.9, and 17.1 mmol. Except for treatment III, diuresis and/or natriuresis were found to be time dependent, generally decreasing with time until reaching a low plateau during the later hours of infusion. The present findings also show that (i) no fluid replacement and 100% replacement with D-5-W both produce the same degree (not significantly different) of severe acute tolerance in natriuresis, indicating the insignificance of water compensation in tolerance development; (ii) in treatment II, where neutral sodium balance was achieved, the development of acute tolerance in diuresis can mainly be attributed to negative water balance under this special condition; and (iii) at steady state the hourly diuresis and natriuresis can differ up to about 6.87- and 5.21-fold between treatments. Some implications for the bioequivalence evaluation of dosage forms of azosemide are discussed.

Hematogenous endophthalmitis in a patient with candidemia

Candidiasis has emerged as the most common opportunistic fungal disease over recent decades owing to the progressively increasing use of antibiotics, immunosuppressive and cytotoxic drugs, indwelling foreign bodies and organ transplantation. Hematogenous candida endophthalmitis, which has a characteristic finding of single or multiple fluffy white cotton ball-like chorioretinal lesions often extending into vitreous, is the most fulminant manifestation of systemic candidiasis and may result in blindness. These ocular lesions can be easily recognized on funduscopic examination and should be serially looked for in all patients with known and suspected systemic candidiasis. We report hematogenous candida endophthalmitis in a patient of systemic candidiasis and, to our knowledge, it is the first reported case in our country.