Long-term performance of the IGRA to predict and prevent active tuberculosis development in HIV-infected patients

<sec id="st1"> <title>OBJECTIVE</title> To estimate the long-term performance of the interferon-gamma release assay (IGRA) in predicting active tuberculosis (ATB) development among human immunodeficiency virus (HIV) infected patients in an intermediate TB burden country. </sec> <sec id="st2"> <title>DESIGN</title> A retrospective cohort study was conducted. HIV-infected patients with 1 IGRA result but no current or previous ATB who had been retained in care for 1 year were enrolled and observed for ATB development from 2006 to 2016. </sec> <sec id="st3"> <title>RESULTS</title> Sixty-two IGRA-positive and 354 IGRA-negative patients were observed for a median period of 4.03 years. ATB incidence in IGRA-positive vs. negative patients was respectively 15.24/1000 person-years (py) (95%CI 4.15-39.02) vs. 0.67/1000 py (95%CI 0.01-3.68) (P = 0.001). The sensitivity, specificity and positive and negative predictive values of the IGRA were respectively 80.0% (28.4-99.5%), 85.9% (82.1-89.1%), 6.5% (4.0-10.2%) and 99.7% (98.4-99.9%). Among the 62 IGRA-positive patients, 25 were treated for latent tuberculous infection (LTBI) and 37 were not. Patients with LTBI treatment did not develop ATB, while four cases of ATB occurred among patients without LTBI treatment. Among the 257 IGRA-negative patients who received a follow-up IGRA, 34 (12.9%) patients converted to positive. No ATB developed in IGRA converters. </sec> <sec id="st4"> <title>CONCLUSION</title> Screening for LTBI using IGRAs and LTBI treatment can be useful to prevent ATB in an intermediate TB burden country. </sec>.

MicroRNA-30a-5p (miR-30a) regulates cell motility and EMT by directly targeting oncogenic TM4SF1 in colorectal cancer

PURPOSE

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide, and many oncogenes and tumor suppressor genes are involved in CRC. MicroRNAs (miRNAs) are small non-coding RNAs that can negatively regulate gene expression. Previous studies have revealed that miRNAs regulate the development and progression of many cancers. In this study, we investigated the role of microRNA-30a-5p (miR-30a) in CRC and its unknown mechanisms.

METHODS

qRT-PCR was used to detect miR-30a and TM4SF1 mRNA expression in CRC specimens and cell lines. CRC cell migration and invasion were assessed after transfection with miR-30a or TM4SF1 using wound healing and trans-well migration and invasion assays. Transmembrane-4-L-six-family protein (TM4SF1) was validated as a target of miR-30a in CRC through luciferase reporter assay and bioinformatics algorithms. Moreover, two EMT regulators, E-cadherin and VEGF, were also identified using Western blotting and immunohistochemistry.

RESULTS

We found that miR-30a was down-regulated in CRC tumor tissues and cell lines, and miR-30a was inversely associated with advanced stage and lymph node metastatic status compared with normal tissues. miR-30a decreased migration and invasion in CRC cell lines, and miR-30a overexpression not only down-regulated TM4SF1 mRNA and protein expression, but also inhibited the expression of VEGF and enhanced expression of E-cadherin. We also showed that TM4SF1 was up-regulated in CRC tumor specimens compared with adjacent normal tissues, and TM4SF1 expression was significantly associated with advanced stage and lymph node status compared with adjacent normal tissues.

CONCLUSIONS

These results suggest that miR-30a is an important regulator of TM4SF1, VEGF, and E-cadherin for CRC lymph node metastasis, a potential new therapeutic target in CRC.

Geographical Variation of Liver Cancer Mortality in Korea (1992-1998)

PURPOSE

The death rate of liver cancer in Korea has been reported as one of the highest in the world. This study was conducted to investigate geographical variations of liver cancer mortality in Korea in order to obtain insight into possible environmental factors related to liver cancer.

MATERIALS AND METHODS

The sex-specific standardized mortality ratios (SMRs) of liver cancer were calculated for 168 basic administrative units in Korea based upon the vital statistics for the seven years 1992 to 1998, as well as the sex- and age-specific population of each area for 1995. The SMRs were classified into six categories and depicted on a map for each sex.

RESULTS

The southern provinces showed clearly higher mortality rates as compared to the rest of the country in both males and females. Looking at the maps in detail, there was a geographical variation even within the southern provinces. The areas around large rivers, some costal areas, and costal islands showed a high mortality rate. Even in the middle and northern provinces, the eastern costal areas showed relatively higher mortality rates as compared to inland areas. Conversely, some southern areas known for low levels of pollution showed relatively lower mortality rates.

CONCLUSION

This finding suggests a possible relationship between liver cancer and water-related foods from polluted rivers or seas. Further studies should be performed in order to clarify which factors cause this geographical variation.

Anti-androgen receptor ASC-J9 versus anti-androgens MDV3100 (Enzalutamide) or Casodex (Bicalutamide) leads to opposite effects on prostate cancer metastasis via differential modulation of macrophage infiltration and STAT3-CCL2 signaling

Despite androgen deprivation therapy (ADT) suppression of prostate cancer (PCa) growth, its overall effects on PCa metastasis remain unclear. Using human (C4-2B/THP1) and mouse (TRAMP-C1/RAW264.7) PCa cells–macrophages co-culture systems, we found currently used anti-androgens, MDV3100 (enzalutamide) or Casodex (bicalutamide), promoted macrophage migration to PCa cells that consequently led to enhanced PCa cell invasion. In contrast, the AR degradation enhancer, ASC-J9, suppressed both macrophage migration and subsequent PCa cell invasion. Mechanism dissection showed that Casodex/MDV3100 reduced the AR-mediated PIAS3 expression and enhanced the pSTAT3-CCL2 pathway. Addition of CCR2 antagonist reversed the Casodex/MDV3100-induced macrophage migration and PCa cell invasion. In contrast, ASC-J9 could regulate pSTAT3-CCL2 signaling using two pathways: an AR-dependent pathway via inhibiting PIAS3 expression and an AR-independent pathway via direct inhibition of the STAT3 phosphorylation/activation. These findings were confirmed in the in vivo mouse model with orthotopically injected TRAMP-C1 cells. Together, these results may raise the potential concern about the currently used ADT with anti-androgens that promotes PCa metastasis and may provide some new and better therapeutic strategies using ASC-J9 alone or a combinational therapy that simultaneously targets androgens/AR signaling and PIAS3-pSTAT3-CCL2 signaling to better battle PCa growth and metastasis at castration-resistant stage.

Androgen receptor (AR) differential roles in hormone-related tumors including prostate, bladder, kidney, lung, breast and liver

The androgen receptor (AR) is expressed in many cell types and the androgen/AR signaling has been found to have important roles in modulating tumorigenesis and metastasis in several cancers including prostate, bladder, kidney, lung, breast and liver. However, whether AR has differential roles in the individual cells within these tumors that contain a variety of cell types remains unclear. Generation of AR knockout (ARKO) mouse models with deletion of AR in selective cells within tumors indeed have uncovered many unique AR roles in the individual cell types during cancer development and progression. This review will discuss the results obtained from various ARKO mice and different human cell lines with special attention to the cell type- and tissue-specific ARKO models. The understanding of various results showing the AR indeed has distinct and contrasting roles in each cell type within many hormone-related tumors (as stimulator in bladder, kidney and lung metastases vs as suppressor in prostate and liver metastases) may eventually help us to develop better therapeutic approaches by targeting the AR or its downstream signaling in individual cell types to better battle these hormone-related tumors in different stages.

Aryl hydrocarbon receptor (AHR)-active pharmaceuticals are selective AHR modulators in MDA-MB-468 and BT474 breast cancer cells

Leflunomide, flutamide, nimodipine, mexiletine, sulindac, tranilast, 4-hydroxytamoxifen, and omeprazole are pharmaceuticals previously characterized as aryl hydrocarbon receptor (AHR) agonists in various cell lines and animal models. In this study, the eight AHR-active pharmaceuticals were investigated in highly aggressive aryl hydrocarbon (Ah)-responsive BT474 and MDA-MB-468 breast cancer cell lines, and their effects on AHR protein, CYP1A1 (protein and mRNA), CYP1B1 (mRNA), and cell migration were determined. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was used as a positive control. The AHR agonist activities of the pharmaceuticals depended on structure, response, and cell context. Most compounds induced one or more AHR-mediated responses in BT474 cells, whereas in Ah-responsive MDA-MB-468 cells effects of the AHR-active pharmaceuticals were highly variable. 4-Hydroxytamoxifen, mexiletine, and tranilast did not induce CYP1A1 in MDA-MB-468 cells; moreover, in combination with TCDD, mexiletine was a potent AHR antagonist, tranilast was a partial antagonist, and 4-hydroxytamoxifen also exhibited some AHR antagonist activity. Omeprazole and, to a lesser extent, sulindac and leflunomide were full and partial AHR agonists, respectively, in both breast cancer cell lines. These data indicate that the AHR-active pharmaceuticals are selective AHR modulators, and applications of these drugs for targeting the AHR must be confirmed by studies using the most relevant cell context.

MDM2 regulates estrogen receptor α and estrogen responsiveness in breast cancer cells

Murine double minute clone 2 (MDM2) is a multifunctional protein, which modulates nuclear receptor-mediated transactivation. In this study, we show that MDM2 significantly enhanced estrogen receptor α (ERα) and ERα/specificity protein-mediated transactivation in MCF-7 and ZR-75 breast cancer cells. This was demonstrated by both MDM2 overexpression and knockdown experiments by RNA interference. ERα interacted with wild-type MDM2 and deletion mutants of MDM2 containing amino acids 1-342 (C-terminal deletion) and 134-490 (N-terminal deletion), but not 134-342. In contrast, only wild-type but not mutant MDM2 enhanced ERα-mediated transactivation. Protein-protein interactions in vitro were 17β-estradiol (E(2)) independent, whereas fluorescent resonance energy transfer experiments in living cells showed that E(2) enhanced ERα-MDM2 interactions. Subsequent RNA interference and mammalian two-hybrid experiments suggested that MDM2 did not directly interact with endogenous coactivators such as the steroid receptor coactivators but played a role in enhancing ERα-mediating gene expression and estrogen responsiveness through interactions with ERα.

Peroxisome proliferator-activated receptor gamma-dependent activity of indole ring-substituted 1,1-bis(3'-indolyl)-1-(p-biphenyl)methanes in cancer cells

PURPOSE

1,1-Bis(3-indolyl)-1-(p-substituted phenyl)methanes (C-DIMs) substituted in the phenyl ring with a para-, t-butyl, trifluoromethyl (DIM-C-pPhCF(3)) or phenyl (DIM-C-pPhC(6)H(5)) group activate peroxisome proliferator-activated receptor gamma (PPARgamma) in several cancer cell lines, and DIM-C-pPhCF(3) also activates the orphan receptor Nur77. In this study, we have examined the effects of 5,5'-dihydroxy, 5,5'-dimethyl, 5,5'-dibromo, 5,5'-dinitro and 5,5'-dimethoxyindole ring-substituted analogs of DIM-C-pPhC(6)H(5) on their activity as PPARgamma agonists.

METHODS

Various substituted C-DIM analogs were used to investigate their growth-inhibitory activities and activation of PPARgamma-mediated transactivation in colon and pancreatic cancer cells. Their structure-dependent induction of putative PPARgamma-responsive genes/proteins including p21, KLF-4 and caveolin1 were also determined by Western and Northern blot analysis.

RESULTS

Introduction of the 5,5'-dihydroxy and 5,5'-dimethyl substituents enhanced activation of PPARgamma in colon and pancreatic cancer cells. However, activation of p21 in Panc28 pancreatic cancer cells and induction of caveolin-1 and KLF4 in colon cancer cells by the C-DIM compounds were structure- and cell context-dependent.

CONCLUSIONS

The results demonstrate that DIM-C-pPhC(6)H(5) and indole ring-substituted analogs are selective PPARgamma modulators.

Tolfenamic acid inhibits esophageal cancer through repression of specificity proteins and c-Met

The non-steroidal anti-inflammatory drug tolfenamic acid (TA) inhibits proliferation of SEG-1 and BIC-1 esophageal cancer cells with half-maximal growth inhibitory concentration values of 36 and 48 muM, respectively. TA also increased Annexin V staining in both cell lines, indicative of proapoptotic activity. Treatment of SEG-1 and BIC-1 cells with TA for up to 72 h decreased expression of specificity protein (Sp) transcription factors Sp1, Sp3 and Sp4 and this was accompanied by decreased expression of the well-characterized Sp-regulated genes cyclin D1, vascular endothelial growth factor and survivin. TA also decreased hepatocyte growth factor receptor, (c-Met), a receptor tyrosine kinase that is overexpressed in esophageal cancer cells and tumors and is an important drug target. Knockdown of Sp1, Sp3 and Sp4 by RNA interference in SEG-1 and BIC-1 cells also decreased c-Met expression, demonstrating that c-Met is an Sp-regulated gene in esophageal cancer cells. Sp1 was overexpressed in esophageal cancer cells and tumors and increased Sp1 staining was observed in esophageal tumors from patients. TA (20 mg/kg/day) also decreased tumor growth and weight in athymic nude mice bearing SEG-1 cells as xenografts and this was accompanied by increased apoptosis and decreased Sp1 and c-Met staining in tumors from treated mice. Thus, TA-dependent downregulation of Sp transcription factors and c-Met defines a novel chemotherapeutic approach for treatment of esophageal cancer.

Control of microorganisms and reduction of biogenic amines in chicken breast and thigh by irradiation and organic acids

The effect of irradiation or organic acid treatment of raw chicken breast and thigh meat to control inoculated microorganisms and the production of biogenic amines (BA) was studied. Bacillus cereus, Enterobacter cloacae, and Alcaligenes faecalis were selected and inoculated into raw ground chicken breast and thigh meat at approximately 10(7) cfu/g. The samples were irradiated at 0, 0.5, 1, and 2 kGy or mixed with a 0.2 M solution of acetic, citric, or lactic acid (1 mL for 10 g of meat sample) for 24 h at 4 degrees C. Viable cell counts and BA contents were determined. Irradiation was effective in reducing the inoculated bacteria: 0.5 kGy achieved approximately a 2-log reduction, and no viable cells were detected at a dose of 2 kGy. In contrast, only up to a 1-log reduction was achieved by organic acid treatment except for citric acid, which achieved approximately a 3-log reduction of E. cloacae. Both the irradiation and organic acid treatment of raw chicken breast and thigh reduced the BA content, but the rate of BA reduction differed by inoculated organism and treatment (irradiation or organic acid). Although irradiation was an excellent method for controlling inoculated microorganisms, the content of BA produced was similar to that of the organic acid treatment of raw chicken breast and thigh meat.

Some fungal endophytes from vegetable crops and their anti-oomycete activities against tomato late blight

AIMS

To isolate endophytic fungi from vegetable plants and examine their in vivo anti-oomycete activity against Phytophthora infestans in tomato plants.

METHODS AND RESULTS

Endophytic fungi were isolated from surface-sterilized plant tissues and anti-oomycete activity was measured by in vivo assay using tomato seedlings. Endophytic fungi showing potent anti-oomycete activity were identified by morphological characteristics and nuclear ribosomal ITS1-5.8S-ITS2 sequence analysis. A total of 152 isolates were obtained from 66 healthy tissue samples of cucumber, red pepper, tomato, pumpkin and Chinese cabbage and the fermentation broths of 23 isolates showed potent in vivo anti-oomycete activity against tomato late blight with control values over 90%. The Fusarium oxysporum strain EF119, which was isolated from roots of red pepper, showed the most potent disease control efficacy against tomato late blight. In dual-culture tests, it inhibited the growth of Pythium ultimum, P. infestans and Phytophthora capsici.

CONCLUSIONS

Among endophytic fungi isolated from healthy tissues of vegetable plants, F. oxysporum EF119 showed the most potent in vivo anti-oomycete activity against tomato late blight and in vitro anti-oomycete activity against several oomycete pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic fungi showing anti-oomycete activity in vitro and in vivo may be used as biocontrol agents particularly of tomato late blight.

MERTK polymorphisms associated with risk of haematological disorders among Korean SLE patients

OBJECTIVE

The MER receptor tyrosine kinase (MERTK) gene is critical for the efficient clearance of apoptotic cells and has implications for inflammation and autoimmune diseases such as systemic lupus erythematosus (SLE). We investigated the genetic polymorphisms in MERTK to evaluate it as a potential candidate gene for a host genetic study of SLE and clinical manifestations in patients with SLE.

METHODS

By resequencing the coding and flanking regions of the MERTK gene in 24 unrelated Koreans, 37 polymorphisms were identified. Based on gene position, minor allele frequency and inter-single-nucleotide polymorphism (SNP) linkage disequilibrium, six of these polymorphisms were selected for subsequent genotyping and association analysis with the risk of SLE and haematological disorders in 350 Korean SLE patients and 330 controls.

RESULTS

Although no significant associations with the risk of SLE were found, logistic regression analyses revealed that variants +465C > G (P = 0.05) and +130215insdelT (P = 0.0005) were significantly associated with decreased risk of leucopenia in SLE patients. Further, +465C > G, +95616G > A, +123157A > G and the haplotype ht1 also showed significant associations (P = 0.006-0.05) with a decreased risk of lymphopenia in SLE patients.

CONCLUSION

Our findings suggest that polymorphisms in MERTK might be one of the genetic risk factors for presenting leucopenia and lymphopenia in SLE patients.

E2F decoy oligodeoxynucleotides on neointimal hyperplasia in canine vein graft

Double-stranded DNA with high affinity to E2F as a decoy cis-element blocks the activation of genes mediating the cell cycle, resulting in effective suppression of the smooth muscle cell proliferation that causes intimal hyperplasia. To evaluate the effect of the E2F decoy to suppress neointimal hyperplasia autogenous venous bypass grafts were performed in dogs after incubation with heparin (group 1), with E2F decoy oligodeoxynucleotides (ODN) (groups 2 and 3), or with a random ODN (group 4) using a Japan-liposomeal method based on a hemagglutinating virus. The intimal and medial cross-sectional surface area of the anastomotic site was measured at 4 months after bypass surgery in groups 1, 3, and 4 by computerized planimetry and at 4 weeks in group 2 to compare the intimal/medial (I/M) area ratios. Autogenous vein grafts treated with E2F decoy showed a significant reduction in I/M area ratio (0.26 +/- 0.11) compared with the heparin-treated control group (1.49 +/- 0.29) or the mismatched ODN-treated group (1.61 +/- 0.28; P = .000). There was no difference in the I/M area ratio according to experimental periods (groups 2 vs 3: 0.26 +/- 0.11 vs 0.37 +/- 0.32; P = .446) or the anastomotic sites (proximal vs distal; P = .934). In conclusion, an E2F decoy can suppress neointimal hyperplasia in autogenous vein grafts, which may prolong patency by reducing graft stenosis.

Multicomponent phenol hydroxylase-catalysed formation of hydroxyindoles and dyestuffs from indole and its derivatives

AIMS

To establish multicomponent phenol hydroxylases (mPHs) as novel biocatalysts for producing dyestuffs and hydroxyindoles such as 7-hydroxyindole (7-HI) from indole and its derivatives.

METHODS AND RESULTS

We have isolated Pseudomonas sp. KL33, which possesses a phenol degradation pathway similar to that found in Pseudomonas sp. CF600. Pseudomonas sp. KL28 is a strain that can grow on n-alkylphenols as a carbon and energy source. Escherichia coli strains expressing mPH from strain KL28 (mPH(KL28)) and strain KL33 (mPH(KL33)) catalysed the formation of indigo and 7-HI, respectively, from indole. In addition, both mPHs catalysed the production of dyestuffs and hydroxyindoles from indole derivatives. The mPH(KL28) has proved to be one of the most versatile biocatalysts that can accommodate a wide range of indole derivatives for catalysing the formation of dyestuffs.

CONCLUSIONS

The present work provides a new approach in producing various dyestuffs and hydroxyindoles from indole and its derivatives by mPHs.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results indicate that mPHs may serve as potential agents for organic syntheses as well as bioremediation.

Role of rho-kinase activity in angiotensin II-induced contraction of rabbit clitoral cavernosum smooth muscle

Isometric tension measurement using a selective Rho-kinase inhibitor (+)- (R)-trans4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide (Y-27632) and a selective myosin light chain kinase (MLCK) inhibitor 1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride (ML7) were used in rabbit clitoral cavernosum smooth muscle (CSM). N(G)-nitro-L-arginine methyl ester (L-NAME) was used to evaluate the relationship between NO release and Rho-kinase. Y-27632 significantly attenuated contractions induced by ANG II, dose-dependently. However, ML7 did not affect the contractile response to ANG II except in the high concentrations of ML7. Y-27632 inhibited contraction with phenylephrine (PhE), but ML7 did not inhibit contraction with PhE. Nitric oxide synthase inhibitor (NAME) did not affect the Y-27632-induced relaxation in the pre-contracted strip with PhE. The present study demonstrates that G-protein-coupled increase in myofilament Ca(2+) sensitivity mediated through the RhoA/Rho-kinase signal pathway is involved in the control by ANG II of the clitoral CSM tone. RhoA/Rho-kinase pathway acts in the ANG II-induced contraction independently of the NO pathway.

Primary antiphospholipid syndrome presenting with abdominal angina and splenic infarction

The antiphospholipid syndrome is an autoimmune hypercoagulability syndrome in which a wide variety of thromboembolic diseases may occur. Gastrointestinal manifestations associated with vascular occlusion include Budd-Chiari syndrome, hepatic and splenic infarction, pancreatitis, omental and intestinal infarction, and esophageal variceal bleeding due to portal vein thrombosis, but chronic mesenteric ischemia associated with mesenteric arterial thrombosis is very rare in this syndrome. We experienced a female patient with primary antiphospholipid syndrome with abdominal angina and splenic infarction associated with celiac trunk and mesenteric arterial thromboses. This is the first report describing chronic mesenteric ischemia and splenic infarction in a patient with primary antiphospholipid syndrome.

Activation of caspase-8 during N-(4-hydroxyphenyl)retinamide-induced apoptosis in Fas-defective hepatoma cells

We observed that N-(4-hydroxyphenyl)retinamide (4HPR), a chemopreventive and chemotherapeutic agent, effectively induced apoptosis in hepatoma cells. Interestingly, Fas-negative (Hep 3B and PLC/PRF/5) hepatoma cells were shown to be more susceptible to apoptosis induced by 4HPR than were Fas-positive (Hep G2 and SK-HEP-1) hepatoma cells. Thus, we explored the mechanisms underlying 4HPR-induced apoptosis in Fas-defective hepatoma cells. Hep 3B cells stably expressing the dominant-negative Fas-associated death domain (dnFADD) showed no alteration in 4HPR drug susceptibility, but when stably expressing E1B19K, Crm A, or dominant-negative FLICE (dnFLICE), Hep 3B cells were resistant, suggesting that 4HPR-induced apoptosis was mediated by caspase-8 activation. Furthermore, apoptosis could be completely blocked by Z-VAD-FMK (a general caspase inhibitor) or by IETD-CHO (a caspase-8 inhibitor), but was only partially blocked by Ac-DEVD-CMK (a caspase-3 inhibitor), by N-acetyl-L-cysteine (NAC) (an antioxidant), by N-acetyl-leucyl-leucyl-norleucinal (ALLN) (a calpain inhibitor I), or by Z-LEHD-FMK (a caspase-9 inhibitor). Time-sequence analysis of the induction of apoptosis by 4HPR revealed that an initial caspase-8 activation was followed by late mitochondrial cytochrome c release and minor caspase-9 activation, which suggested that caspase-8 activation is the primary upstream regulatory point. Activation of Bid or induction of proapoptotic Bax was not observed during apoptosis. In contrast, Bcl-xL expression was decreased during 4HPR-induced apoptosis. Taken together, these results indicate that 4HPR may be a potential chemotherapeutic drug, which is able to induce apoptosis in Fas-defective hepatoma cells through caspase-8 activation.

Low-level resistance to glycopeptides amongst staphylococcus species: surveillance in a university hospital and evaluation of a vancomycin screening agar

The prevalence of low-level resistance to glycopeptides (teicoplanin MIC > or = 8 microg/mL and vancomycin MIC > or = 4 microg/mL) among staphylococci was investigated over a 15 month period. A total of 2,279 isolates (1,519 S. aureus, 760 coagulase-negative staphylococcus (CNS)) were screened using inoculum of 10(6) CFU/mL and Mueller-Hinton agars supplemented with 8 microg/mL of teicoplanin. Of these, 218 isolates (136 S. aureus and 82 CNS) grew on the screening agar. For these isolates, teicoplanin and vancomycin MICs were determined by agar dilution method and a vancomycin agar screening method was evaluated. The prevalence of low-level resistance to teicoplanin and vancomycin was 7.8% and 0.1% for S. aureus and 8.8% and 0.8% for CNS, respectively. The brain heart infusion agar containing 4 microg/mL of vancomycin failed to detect two out of eight staphylococcal isolates with vancomycin MICs of 4 microg/mL. Furthermore, the method appeared to lack reproducibility. Considering the increasing incidence of vancomycin treatment failure in staphylococcal infection, a more reliable screening method is required.

Absence of mutation in the region (nt. 710-1010) of pbp4 gene in clinical isolates of Staphylococcus aureus with low-level teicoplanin resistance

Resistance to teicoplanin in clinical isolates of Staphylococcus aureus has increased in frequency. Detection is difficult due to heterogeneous phenotypes of these strains. Two mutations in pbp4 have recently been identified in glycopeptide resistant laboratory strains. We investigated to determine if these mutations could be used to screen clinical isolates for teicoplanin resistance. Of 41 clinical isolates screened, none contained the mutations in pbp4 indicating these mutations cannot be used as a molecular diagnostic tool for glycopeptide resistance.

Palliation of postoperative gastrointestinal anastomotic malignant strictures with flexible covered metallic stents: preliminary results

PURPOSE

To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer.

METHODS

Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48-76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated.

RESULTS

Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2-31 weeks (mean 8.5 weeks) there were no major complications.

CONCLUSION

These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer.

Involvement of an extracellular protease in algicidal activity of the marine bacterium Pseudoalteromonas sp. strain A28

The marine bacterium Pseudoalteromonas sp. strain A28 was able to kill the diatom Skeletonema costatum strain NIES-324. The culture supernatant of strain A28 showed potent algicidal activity when it was applied to a paper disk placed on a lawn of S. costatum NIES-324. The condensed supernatant, which was prepared by subjecting the A28 culture supernatant to ultrafiltration with a 10,000-M(w)-cutoff membrane, showed algicidal activity, suggesting that strain A28 produced extracellular substances capable of killing S. costatum cells. The condensed supernatant was then found to have protease and DNase activities. Two Pseudoalteromonas mutants lacking algicidal activity, designated NH1 and NH2, were selected after N-methyl-N'-nitrosoguanidine mutagenesis. The culture supernatants of NH1 and NH2 showed less than 15% of the protease activity detected with the parental strain, A28. The protease was purified to homogeneity from A28 culture supernatants by using ion-exchange chromatography followed by preparative gel electrophoresis. Paper-disk assays revealed that the purified protease had potent algicidal activity. The purified protease had a molecular mass for 50 kDa, and the N-terminal amino acid sequence was determined to be Ala-Thr-Pro-Asn-Asp-Pro. The optimum pH and temperature of the protease were found to be 8.8 and 30 degrees C, respectively, by using succinyl-Ala-Ala-Pro-Phe-p-nitroanilide as a substrate. The protease activity was strongly inhibited by phenylmethylsulfonyl fluoride, diisopropyl fluorophosphate, antipain, chymostatin, and leupeptin. No significant inhibition was detected with EDTA, EGTA, phenanthroline or tetraethylenepentamine. These results suggest that Pseudoalteromonas sp. strain A28 produced an extracellular serine protease which was responsible for the algicidal activity of this marine bacterium.

Synthesis and antimicrobial activity of squalamine analogue

Synthesis and antimicrobial activity of squalamine analogue 2 are reported. The synthesis of 2 was accomplished from bisnoralcohol 3. The spermidine moiety was introduced via reductive amination of an appropriately functionalized 3beta-aminosterol with spermidinyl aldehyde 17 utilizing sodium triacetoxyborohydride as the reducing agent. Compound 2 shows weaker antimicrobial activity than squalamine.

Purification and characterization of biosurfactants from Nocardia sp. L-417

The Nocardia sp. L-417 strain grown with n-hexadecane as a carbon source produced two types of biosurfactant that have different characteristics. These biosurfactants were purified by procedures that included ammonium sulphate fractionation, chilled acetone and hexane treatments, silica-gel column chromatography and Sephadex LH-20 gel filtration. The purified biosurfactants were very stable over a broad range of pHs (2-12) and temperatures (100 degrees C, 3 h). The biosurfactant type I had strong properties as an emulsifying agent and as an emulsion-stabilizing agent, whereas type II had a strong ability to reduce surface tension.

Screening method for detecting staphylococci with reduced susceptibility to teicoplanin

The incidence of infections caused by staphylococci with decreased susceptibility to teicoplanin (MIC>/=8 microg/ml) is increasing, but the disk diffusion test has difficulty detecting this low level of resistance. In addition, detection is complicated because of the heterogeneous phenotypes for teicoplanin. In this study, we evaluated an agar screening method to detect staphylococci with decreased susceptibility to teicoplanin or heterogeneous resistance. First, to investigate the inoculum density and teicoplanin concentration of screening agar, we used 10(5) and 10(6) CFU/ml and Mueller-Hinton agars supplemented with 6 and 8 microg of teicoplanin/ml to test 39 genetically distinct staphylococcal strains (15 strains with teicoplanin MICs>/=8 microg/ml and 24 strains with teicoplanin MICs</=4 microg/ml). On the basis of the results obtained, a final inoculum of 10(6) CFU/spot and a teicoplanin concentration of 8 microg/ml were selected. By this screening method, all strains having teicoplanin MICs>/=8 microg/ml or showing heteroresistance could be detected. These findings indicate that the method can be used as a reliable screening method for detecting staphylococci with reduced susceptibility to teicoplanin.

Effect of nodularin on the expression of glutathione S-transferase placental form and proliferating cell nuclear antigen in N-nitrosodiethylamine initiated hepatocarcinogenesis in the male Fischer 344 rat

The tumor-promoting effect of nodularin during carcinogenesis was investigated. Male Fischer 344 rats were injected with nodularin for 10 weeks from week 3 after N-nitrosodiethylamine initiation without partial hepatectomy. Rats were further maintained for 10 weeks after the cessation of nodularin and were periodically killed. In contrast to the minimal foci in the DEN and nodularin alone groups, treatment with DEN and nodularin produced four kinds of nodules with eosinophilic, clear, mixed and basophilic cells. After the cessation of nodularin, the maximally increased number, but not the area, of glutathione S-transferase placental form-positive [GST-P(+)] nodules at week 12 decreased significantly and the appearance of two types of hyperplastic nodules was noted by GST-P immunostaining; homogeneously stained dense nodules (DN) and heterogeneously stained pale nodules (PN), which appeared only after the cessation of nodularin. DN were well circumscribed by enzyme-altered cells, as opposed to poorly in PN. Moreover, normal-appearing hepatocytes replaced the enzyme-altered cells in PN. In contrast to the higher PCNA index in GST-P(+) DN, the background level returned to that of the control at week 15. PCNA indices in DN were significantly higher than in PN, which were still higher than the control, indicating that nodularin affected the PCNA index differentially in the altered and unaltered hepatocytes. However, nodularin without DEN initiation significantly increased the PCNA index through initial cell death and subsequent hepatocyte proliferation. These results suggest that: (i) nodularin has a promoting effect by inducing hepatocyte proliferation in both enzyme-altered hyperplastic nodules and the surrounding parenchyma; (ii) proliferation is transient in background cells but not in enzyme-altered hepatocytes; (iii) GST-P(+) DN can be regarded as progressive and GST-P(+) PN as regressive, revealed by both immunohistochemistry and PCNA index.

Purification and characterization of a levanbiose-producing levanase from Pseudomonas sp. No. 43

A levanbiose-accumulating levanase from Pseudomonas sp. No. 43 was purified to a homogeneous state by (NH4)2SO4 fractionation and by chromatography on DEAE-Toyopearl 650 M and phenyl-Toyopearl 650 M columns. The molecular mass and isoelectric point of the enzyme were estimated to be 36 kDa and 5.7 respectively; the optimal pH and temperature for the enzyme reaction were pH 7.0 and 40 degrees C respectively. The purified enzyme was stable in the pH range 6.0-8.0 at 20 degrees C and stable up to 50 degrees C at pH 7.0. The enzyme's activity was inhibited by MnCl2, CoCl2, AlCl3, EDTA and potassium permanganate. The levanase was specific towards the 2, 6-beta-D-fructosidic linkages of levan and did not hydrolyse other polysaccharides among those examined. The enzyme is an exohydrolase of levan and produced levanbiose as a sole product; the limits of hydrolysis of levans from Zymomonas mobilis and Serratia sp. were 65% and 80% respectively.

Distribution of rantes and interleukin-5 in allergic nasal mucosa and nasal polyps

Eosinophil-chemoattracting cytokines are thought to be important in the pathogenesis of allergic inflammation. However, little is known about the presence and significance of RANTES in nasal allergy and nasal polyps, two well-known rhinologic disorders characterized by eosinophil infiltration in the tissue. In order to evaluate the role of RANTES in eosinophil infiltration in vivo, the tissue distributions of RANTES and interleukin-5 (IL-5) and their correlation with eosinophil infiltration were investigated. Nasal mucosa specimens were obtained from 9 allergic and 12 control subjects, and nasal polyps from 6 allergic and 9 nonallergic subjects. All the subjects were divided into 4 groups: normal mucosa, allergic mucosa, nonallergic polyps, and allergic polyps. To identify the cellular localizations of RANTES and IL-5, we used specific immunohistochemical staining. We also investigated the differences in cytokine expression among the 4 groups, and the correlation between cytokine expression and eosinophil infiltration in the tissue. RANTES was expressed in the epithelium, endothelium, and some submucosal cells, while IL-5 was confined to the cells in the submucosa. Expression of both RANTES and IL-5 significantly increased in allergic mucosa and nasal polyps compared to normal mucosa; however, there was no significant difference in their expression between allergic and nonallergic polyps. Both cytokines had a significant correlation between their expression and either total or activated eosinophil numbers. The results of this study suggest that RANTES, as well as IL-5, plays a role in eosinophil recruitment in allergic nasal mucosa and nasal polyps in vivo.

The nitric oxide-producing properties of Ulmi radicis cortex extract

We investigated the effect of Ulmi radicis cortex extract (UrCE) on the production of nitric oxide (NO). Stimulation of mouse peritoneal macrophages with UrCE after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in the increased NO synthesis. UrCE had no effect on NO synthesis by itself. When UrCE was used in combination with rIFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. The optimal effect of UrCE on NO synthesis was shown 6 h after treatment with rIFN-gamma. NO production was inhibited by NG-monomethyl-L-arginine. The increased production of NO from rIFN-gamma plus UrCE-stimulated cells was decreased by the treatment of protein kinase C inhibitor such as staurosporin. In addition, synergy between rIFN-gamma and UrCE was mainly dependent on UrCE-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of UrCE were endotoxin free. These results suggest that the capacity or UrCE to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of UrCE-induced TNF-alpha secretion.

T cell subsets in chronic hepatitis B and the effect of prednisolone withdrawal and interferon alpha-2b

OBJECTIVES

The evaluations of the pathogenetic roles of cell mediated immunity and of the preventive effect for disease progression with interferon(IFN) treatment in patients with chronic active hepatitis-B(CAH-B) are the objectives of this study.

METHODS

Thirty-two patients with CAH-B were treated with interferon alpha-2b(IFN alpha-2b) with prednisolone withdrawal and 30 control patients were treated with conventional hepatotonics for 6 months. Peripheral total T cell fractions and T cell subsets of the patients with CAH-B, treated with IFN alpha-2b with prednisolone withdrawal, were examined 1 month before administration of prednisolone, and compared with 12 normal controls for assessing the potential role of cellular immunity in the development of CAH-B. To estimate the effectiveness of IFN therapy for the patients with CAH-B, levels of various liver function tests, HBsAg, anti-HBs, HBeAg, anti-HBe, HBV DNA, anti-HCV and others were assessed for the treatment group and compared with control patients at pre- and post-treatment period each.

RESULTS

The value of CD4 was significantly lower in patients with CAH-B than normal controls (36.3 +/- 7.7% vs 42.1 +/- 5.7%, p < 0.05) and the value of CD8 was significantly higher in patients with CAH-B than normal controls (30.6 +/- 10.3% vs 24.3 +/- 5.2%, p < 0.05) before prednisolone administration. The patients in responder group (n = 26) had significantly lower CD4 cells compared with normal controls, but non-responders (n = 6) did not have. The levels of liver function test(LFT) in the patients with IFN alpha-2b treatment with prednisolone withdrawal were not different from the control patient group at pretreatment, but significantly lower than control patient group's after treatment, regardless of response to IFN alpha-2b treatment with prednisolone withdrawal.

CONCLUSIONS

The cellular immunity of the host may have a potential role in the pathogenesis of chronicity of hepatitis B infection. IFN alpha-2b treatment with prednisolone withdrawal may be regarded as one of the effective treatment modalities for the inhibition of disease progression in patients with CAH-B.

Purification and characterization of a novel levanoctaose-producing levanase from Pseudomonas strain K-52

Levan-assimilating micro-organisms from soil samples were screened for levanoligosaccharide-generating enzyme production. The isolated strain K-52 produced an extracellular levanoctaose-generating enzyme and was identified as belonging to genus Pseudomonas. The levanase was purified to homogeneity by (NH4)2SO4 fractionation and successive column chromatography on DEAE-cellulose, phenyl-Toyopearl 650 M, Sephadex G-100 and hydroxyapatite. The molecular mass of the enzyme was estimated as approx. 38 kDa by both SDS/PAGE and gel filtration, and its isoelectric point was approx. pH 4.8. The optimum temperature and pH for the enzyme reaction were 35 and 7.0 respectively. The enzyme was stable at a pH range of 6.0-9.0 at 4 degrees C and up to 40 degrees C at pH 6.8. The enzyme activity was inhibited by Fe2+, Cu2+, Hg2+ and Ag2+. The levanase was specific toward 2,6-beta-D-fructosidic linkages of levan and did not hydrolyse other polysaccharides such as inulin and dextran. Chemical modification on the levanase suggested that cysteine and histidine residues are essential for enzyme activity. The levanoctaose liberated by levanase reaction was used selectively only by the intestinal beneficial micro-organisms, such as Bifidobacterium and Lactobacillus spp.

Chaperone-like function of lipocortin 1

Lipocortin 1 (LC1) is a 37 kDa member of the annexin family of proteins. It has been proposed to act as a mediator of some of the actions of glucocorticoids in anti-inflammatory and immune suppressive functions. LC1 has been shown to play a role in cell proliferation, apoptosis, and differentiation. However, the exact biological functions of LC1 still remain obscure. Here it is shown that LC1 displays a chaperone-like function. Stoichiometric amounts of LC1 suppressed thermally induced inactivation and aggregation of the test enzymes citrate synthase and glutamate dehydrogenase. LC1 was also effective in refolding guanine hydrochloride-denatured glutamate dehydrogenase, as judged by circular dichroism spectroscopy.

Lipocortin 1 binding sites on human T-cells: the population of cells with the binding sites is larger in CD8+ T-lymphocytes than in CD4+ T-lymphocytes

Lipocortin 1 (LC1) is believed to be a mediator of glucocorticoids in displaying anti-inflammatory and immune suppressive responses. The existence of specific LC1 binding sites (putative receptor) on monocytes and neutrophils has been reported. We have studied the distribution of LC1 binding sites in human peripheral blood leukocytes by flow cytometry. The population of cells with LC1 binding sites was much larger in monocytes than in lymphocytes in both rheumatoid arthritis patients (93.1 +/- 2.3% vs 8.8 +/- 1.0%) and healthy volunteers (97.0 +/- 0.9% vs 9.9 +/- 1.5%). The LC1 binding cell population was larger in CD8+ T-lymphocytes than in CD4+ T-lymphocytes in both healthy volunteers (26.4 +/- 4.5% vs 10.6 +/- 2.0%) and rheumatoid arthritis patients (28.8 +/- 4.7% vs 8.7 +/- 2.1%). No difference in LC1 binding cell populations was found between rheumatoid arthritis patients and healthy controls.

Bioflocculant produced by Aspergillus sp. JS-42

A bioflocculant from a fungus, Aspergillus sp. JS-42, was purified by precipitations with acetone and cetylpyridinium chloride. The flocculating activity was not significantly affected by pH from 3 to 8, but was stimulated by the addition of CaCl2, and was effective only when the reaction mixture contained an adequate amount of flocculant. The flocculant could efficiently flocculate all tested solids suspended in aqueous solution, including various microorganisms, organic acids, and inorganic materials.

Enzymatic methylation of recombinant heterogeneous nuclear RNP protein A1. Dual substrate specificity for S-adenosylmethionine:histone-arginine N-methyltransferase

We have previously reported the existence of two different molecular species of protein methylase I (S-adenosylmethionine:protein-arginine N-methyltransferase, E.C. 2.1.1.23) in calf brain, one specific for myelin basic protein and the other for histone (Ghosh, S. K., Paik, W. K., and Kim, S. (1988) J. Biol. Chem. 263, 19024-19033). In the present study, however, we report that heterogeneous ribonucleoprotein particle protein A1 is most likely an in vivo substrate for the "histone-specific protein methylase I." The unmethylated recombinant protein A1 has been found to be a much superior methyl acceptor for the enzyme than histone with a Km value two orders of magnitude lower (0.19 microM) than that for histone (21 microM). Myelin basic protein, a specific inhibitor for histone protein methylase I, exhibited a lower IC50 for protein A1 methylation (IC50 = 33 microM) compared with histone methylation (IC50 = 220 microM) and competitively inhibited the former with a Ki value of 1.3 x 10(-6) M. The extent of inhibition of protein A1 and histone methylation by the polyclonal antibodies prepared against purified "histone protein methylase I" was identical. Maximally, 1.08-mol methyl groups were incorporated per mol of protein A1, which was 27-fold higher than that of histone (0.04 mol/mol of histone). HPLC analysis of the enzymatically methylated amino acid residues in protein A1 revealed the formation of NG-monomethylarginine and NG,NG-dimethylarginine. The ratio of NG,NG-dimethylarginine/NG-monomethylarginine increased as a function of incubation period; however, NG,N'G-dimethylarginine was not detectable. Proteolytic cleavage of the methyl-3H-labeled recombinant protein A1 by trypsin and Staphylococcus aureus V8 endoprotease indicated that protein A1 possesses multiple sites for methylation, one of which was identified as residue 194 arginine, which coincided with the in vivo methylation site.

Direct sequencing of superoxide dismutase genes from two bacterial strains amplified by polymerase chain reaction

The nucleotides of the Mn-superoxide dismutase (SOD) gene of Bacillus circulans and the Fe-SOD gene of Aerobacter aerogenes were sequenced by PCR. These SOD genes were specifically amplified by using oligonucleotide primers corresponding to the amino-terminal amino acid sequences and the antisense strand primer corresponding to the common amino acid sequence near the carboxyl-terminus among various Mn- and Fe-SODs thus far sequenced. The PCR products amplified from B. circulans and A. aerogenes genes contained a 486-nucleotide sequence encoding 162 amino acids and a 507-nucleotide sequence encoding 169 amino acids, respectively. Each sequence seemed to contain most of the open reading frame encoding the SOD protein when compared with other sequenced SODs. The two amino acid sequences deduced from the nucleotide sequences of PCR products had an identity of 66.1%. However, the SODs from B. circulans and A. aerogenes were immunologically distinct from each other judging from an immunoprecipitation test. The two SODs had high homologies with other bacterial Mn-SODs, especially the highest homology of 75.4% and 66.7%, respectively, with the B. stearothermophilus Mn-SOD. Genomic Southern hybridization suggested that each PCR product of the bacterial genes that were synthesized and sequenced was the product of the sole SOD gene in each bacterium.

A case of agenesis of the right lobe of the liver

Agenesis of the right lobe of the liver is a rare congenital anomaly and only 29 cases have been reported in the literature. We encountered a patient with this anomaly diagnosed by ultrasonography, Computed tomography (CT), hepatobiliary scintigraphy, endoscopic retrograde cholangiopancreatography (ERCP) and celiac angiography. The radiological findings, differential diagnosis, and clinical significance of this anomaly are reviewed.

Hybrid myeloma cells which secrete heterodimeric IgG: a model to study the N-linked glycan

Fundamental questions remain unanswered regarding the effect of the acceptor polypeptide structure on the fine structure of the N-linked glycan of glycoproteins and conversely, the effect of the glycan structure of IgG on the function and structure of the protein. The construction of myeloma hybrids capable of secreting multiple IgG which differ with regard to the fine structure of their N-linked oligosaccharides would be a valuable model for studying these questions. P3X63Ag8 analogous glycan of the IgG2b secreted by Sp2/HLBu. Fusion hybrids of these cells secrete parental IgG1, and to a lesser degree IgG2b, as well as a heterodimeric IgG containing both the gamma 1 and gamma 2b chains. The oligosaccharide of each chain is identical in structure to the appropriate parental IgG. Such cells allow for the analysis of acceptor properties that influence glycan fine structure, as well as the role of glycan structure on the stability of the IgG.

Purification and characterization of superoxide dismutase from Aerobacter aerogenes

Superoxide dismutase (SOD) was purified from Aerobacter aerogenes IFO 3317 to an electrophoretically homogeneous state and partially characterized. SOD was purified by ammonium sulfate fractionation, column chromatography on DEAE-Sephadex A-50, gel filtration on Sephadex G-100, phenyl-Toyopearl 650 M hydrophobic chromatography, and hydroxyapatite adsorption chromatography. The molecular weight and subunit molecular weight of the purified enzyme were estimated to be 45,000 and 22,000, respectively. The isoelectric point of the enzyme was about pH 4.0. The purified enzyme remained stable at pH 7.0-11.0, 25 degrees C for 36 hrs, but was rapidly inactivated below pH 7.0. SOD was stable up to 35 degrees C at pH 7.0, but was inactivated at temperatures above that. The absorption maximum in the visible range was found at 360 nm, and the enzyme was insensitive to cyanide and fluoride, and sensitive to hydrogen peroxide and azide. These results suggest that the enzyme is an iron-containing SOD. The amino acid composition and the N-terminal sequence of the first 15 amino acids of the enzyme exhibited close homology with the other iron-containing SODs.

Delayed biliary-to-bowel transit in cholescintigraphy after cholecystokinin treatment

The authors assessed the influence of cholecystokinin (CCK), administered before cholescintigraphy, on the biliary-to-bowel transit time (BBTT) of technetium-99m disofenin. Fourteen healthy volunteers underwent two separate cholescintigraphic studies with and without CCK treatment. BBTT was less than 1 hour in all 14 studies of subjects not treated with CCK. In 14 subjects treated with CCK, there was no tracer activity in the bowel up to 2 hours in seven (50%) (P = .006). Eighty-three cholescintigrams obtained in patients with suspected acute cholecystitis were also retrospectively analyzed. In 53 of 83 patients in whom the gallbladder was visualized within 1 hour, significantly delayed BBTT was found in 14 of 29 (48%) who received CCK, compared with the BBTT in one of 24 patients (4%) who did not receive CCK (P less than .001). In the 30 patients in whom the gallbladder was never visualized (n = 28) or was visualized after 1 hour (n = 2), BBTT was less than 30 minutes, regardless of whether patients were treated with CCK. Results show that CCK treatment causes significantly delayed BBTT in many cases, and this finding should not be interpreted as abnormal.

The polypeptide of immunoglobulin G influences its galactosylation in vivo

To examine the nature of the factors influencing the galactosylation pattern of the heavy chain of murine immunoglobulin G (IgG), cell fusion was performed between a myeloma (P3x63Ag8) and a hybridoma (Sp2HL/Bu) cell line which secrete different IgGs possessing structurally distinct CH2-linked oligosaccharide moieties. The glycosylation patterns of the IgGs of the parental and fused cells were studied. Pronase digestion of the purified heavy chains and subsequent end labeling with fluorescein isothiocyanate produced fluoresceinated glycopeptides which were detected and purified by polyacrylamide gel electrophoresis. Structural information was obtained by enzymatic digestion, lectin affinity chromatography, and methylation analysis. IgGs from both parental lines possessed oligosaccharide units displaying microheterogeneity based upon a common symmetrical biantennary structure terminating in beta-GlcNAc. The structures of both IgGs, however, differed in the pattern of the mono- and digalactosylated components. Clones, selected following the fusion of the parental cells, were expanded; and the individual IgGs were purified. All clones produced homodimeric IgG1 and IgG2b as well as heterodimeric IgG possessing both the gamma 1 and gamma 2b heavy chains. Analysis of the carbohydrate moieties of the gamma 1 chain from the homodimeric and heterodimeric IgGs and of the gamma 2b chain from the heterodimeric molecule demonstrates that the polypeptide structure of the heavy chain influences the terminal galactosylation of the glycan unit at the conserved site of glycosylation of IgGs.