Frequent presence of HBV in the sera of HBsAg-negative, anti-HBc-positive blood donors

BACKGROUND

Recent studies have revealed that HBV may not be cleared even after the disappearance of serum HBsAg. The purpose of this study was to investigate whether the replication of HBV persists in HBsAg-negative blood donors who lack apparent liver disease.

STUDY DESIGN AND METHODS

Serum HBV was examined by using PCR coupled with Southern blotting in 50 blood donors who were identified to be HBsAg negative but anti-HBc positive.

RESULTS

HBV DNA was detected in the sera from 19 (38%) of 50 donors. In 11 of the 19, HBV existed exclusively as immune complexes, while HBV presumably did not exist as immune complexes in the remaining eight. The levels of HBV DNA were similar to those in patients who had recovered from acute HBV. Some nucleotide substitutions, which did not confer amino acid changes in the major epitope of HBsAg, were found in the preS-S regions.

CONCLUSION

The replication of HBV is ongoing in a substantial proportion of healthy blood donors who have anti-HBc. Blood from such donors may contain very low levels of HBV free of immune complex formation and should be excluded for transfusion. The fact that such blood donors apparently lacked liver disease suggests no pathogenicity of such "occult" HBV.

Increased telomerase activity and elevated hTERT mRNA expression during multistage carcinogenesis of squamous cell carcinoma of the lung

BACKGROUND

Telomerase activation is believed to play a critical role in the immortalization of cells and carcinogenesis. Telomerase activity is undetectable in normal somatic cells (except for those cells undergoing proliferation) but is expressed in the majority of human tumors including lung carcinoma. The expression of hTERT mRNA has been found to be correlated with telomerase activity. In the current study, the authors analyzed telomerase activity and hTERT mRNA expression in preinvasive bronchial lesions using biopsy specimens obtained by fluorescence bronchoscopy.

METHODS

The authors studied 150 bronchial biopsy specimens obtained by fluorescence bronchoscopy. The intensity of telomerase activity was determined by the fluorescence-based telomeric repeat amplification protocol method in 74 bronchial biopsy specimens (22 normal bronchial epithelium or bronchitis cases, 15 squamous metaplasia cases, 23 dysplasia cases, and 14 squamous cell carcinoma cases), and the level of hTERT mRNA was analyzed in another 76 specimens (24 normal bronchial epithelium or bronchitis cases, 15 squamous metaplasia cases, 20 dysplasia cases, and 17 squamous cell carcinoma cases) by real-time polymerase chain reaction.

RESULTS

The mean values (+/- the standard deviation [SD]) of telomerase activity in normal bronchial epithelium or bronchitis, squamous metaplasia, dysplasia, and squamous cell carcinoma cases were 6.2 +/- 7.5, 13.9 +/- 14.8, 18.5 +/- 20.8, and 54.5 +/- 22.3 U/microg protein, respectively. The upper limit of telomerase activity in normal bronchial epithelium or bronchitis was 21 U/microg protein (mean + 2SD). It is interesting to note that, 5 of 15 squamous metaplasia biopsies (33%), 8 of 23 dysplasia biopsies (35%), and all squamous cell carcinoma biopsies (100%) exhibited levels of telomerase activity that were > 21 U/microg protein. The mean levels of hTERT mRNA in normal bronchial epithelium or bronchitis, squamous metaplasia, dysplasia, and squamous cell carcinoma cases were 891 +/- 840, 1936 +/- 1704, 3019 +/- 2607, and 12965 +/- 18008 copies/microg total RNA, respectively. Telomerase activity and hTERT mRNA expression were found to increase in proportion to the severity of histologic change from normal bronchial epithelium or bronchitis to squamous cell carcinoma.

CONCLUSIONS

These results suggest that an increase in telomerase activity and hTERT mRNA expression are features of the early stages of the development of squamous cell carcinoma of the lung, with strong telomerase activity and hTERT mRNA expression being prominent during the latter stages.

Circulating levels of vitamin K1, menaquinone-4, and menaquinone-7 in healthy elderly Japanese women and patients with vertebral fractures and patients with hip fractures

Recently, vitamin K has become increasingly of interest in the bone metabolism field because of its role as a cofactor in the carboxylation of osteocalcin. Although the role of osteocalcin is not clear, noncarboxylated osteocalcin is one risk factor in hip fractures. It has been reported that the circulating levels of vitamin K1 in osteoporotic patients were significantly lower than those of age-matched control subjects. In this study, we measured circulating levels of vitamin K1, menaquinone-4 (MK-4) and menaquinone-7 (MK-7) in 23 normal healthy women aged 52-93 years (mean +/- SD: 80.1 +/- 3.5), 13 female patients with vertebral fractures aged 66-93 years (80.3 +/- 7.8) and 38 female patients with hip fractures aged 76-87 years (79.8 +/- 9.2), (all Japanese), in order to make sure whether these vitamin K levels were different in these three groups. Serum circulating levels of MK-4 was undetectable in most subjects (only one out of 74). Appreciable numbers from these three groups had undetectable levels of MK-7 (52% of the control group, 23% of the vertebral fracture group and 24% of the hip fracture group). Eight subjects from the normal control group (35%) and five patients from the vertebral group (38%) had undetectable levels of vitamin K1. We did not find a significant difference in the measurable levels of vitamin K1, MK-4 and MK-7 in patients with vertebral fractures or patients with hip fractures compared to age-matched normal controls. Undetectable levels of measured vitamin K1, MK-4 and MK-7 in most of subjects may significantly affect the results.

Entropy-controlled solvolytic dissociation kinetics of lanthanide(III) complexes with polyaminocarboxylates in aqueous solutions

The factors involved in the formation of an inert complex in terms of solvolysis reaction have been studied for lanthanide(III)-acyclic polyaminocarboxylate complexes, as the basis for kinetically controlled selectivity used in analytical methodologies such as HPLC and HPCE. The rate constants for solvolysis and acid-assisted dissociation processes of the lanthanide complexes were determined in a batch system through metal- and ligand-exchange reactions. The reagents used were 8-amino-2-[(2-amino-5-methylphenoxy)methyl]-6-methoxyquinoline-N,N,N',N'-tetraacetic acid (Quin2) and O,O'-bis(2-aminophenyl)ethylene glycol-N,N,N',N'-tetraacetic acid (BAPTA) as octadentate ligands and trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) as a hexadentate ligand. It has been found that the rate constants for solvolysis vary from 5.7 x 10(-3) x s(-1) (La3+) to 1.7 x 10(-6) x s(-1) (Lu3+) depending on the ionic radii of Ln(III) ions for the Quin2 complexes, while no such monotonic dependence was observed for the BAPTA complexes. Among the parameters of activation, it is worth noting that there is a considerably large negative entropy of activation, of up to -250 J x mol(-1) x K(-1), and it is this which is responsible for the inertness of the Ln-polyaminocarboxylate complexes. Our data suggest that multiple ligation of the ligand in favor of the large coordination number of Ln(III) ions is of key importance for formation of the negative entropy of activation, in addition to the basicity of the ligand which also plays a significant role in the slow dissociation kinetics of the Ln(III) complexes.

The use of water structure breakers, urea and guanidium chloride, new mobile phase modifiers in reversed-phase partition high-performance liquid chromatography

Organic solvent-free mobile-phase systems in ion-pair reversed-phase partition high-performance liquid chromatography (IPRP-HPLC) are demonstrated; using urea at 3.0-7.0 molal (mol kg-1) as a modifier in a mobile phase on an octadecylsilanized silica column, four nitrophenolates and metal 4-(2-pyridilazo)resorcinol (PAR) chelates (in PAR chelates system an aqueous mobile phase with 15 wt% methanol was used) were separated rapidly within 6 min at no sacrifice to the separation efficiency. On the addition of urea in the mobile phase, reduced retention times of nitrophenolates and naphthalenesulfonates and also diminution of the height equivalent to a theoretical plate were observed. The addition of urea and guanidium chloride (GuCl) in the mobile phase gave rise to a decrease in the mobile phase volume; in turn, this meant an increased volume of the stationary phase. As the concentration of urea and GuCl in the mobile phase increased, the volume of the mobile phase in the column decreased within about 70% and 40% at 7.0 molal of urea and GuCl, respectively. A decrease in the mobile phase volume suggests an increase in the extent of solvation of the bonded hydrocarbon chain of the stationary phase. The possible explanations for the LC behavior with the urea and GuCl are turned into reduction of hydrophobic interaction in LC processes, solute partitioning and entangling of alkyl chain brushes, with the addition of urea. The water structure breakers, urea and GuCl, most likely affect the solvation states of both solute molecules and the hydrocarboneous stationary phase by changing the nature of the water solvent, which provides a new technique for fine tuning of the LC resolution of the analytes.

Successive determinations of platinum(II) and selenium(IV) with 1,4-dibromo-2,3-diaminonaphthalene in aqueous micellar solutions

Highly sensitive successive determinations for PtII and SeIV ions have been developed based upon reactions with 1,4-dibromo-2,3-diaminonaphthalene (Br2DAN), which forms a near-infrared (NIR) absorbing complex (epsilon = 1.2 x 10(5) l mol-1 cm-1 at 800 nm) and an emissive complex (ex. 386 nm, em. 604 nm) for PtII and SeIV ions, respectively, in acidic aqueous micellar solutions. In the presence of a cationic surfactant, cetyltrimethylammonium chloride, the detection limits for PtII and SeIV ions are 1.2 ng ml-1 (3 sigma) and 0.98 ng ml-1 (S/N = 3), respectively. Hydrobromic acid plays a key role to enhance the color development of the NIR-absorbing PtII complex. The influences of CuII and ZnII ions at the normal human serum levels are readily tolerated, and interference from FeIII ion at 35 mumol l-1 is circumvented by the addition of 50 mumol l-1 of polyaminocarboxylates, such as EDTA.

[Clinical application and limitation of bone metabolic markers in osteoporosis treatment]

In recent years, bone metabolic markers have been one of the most important tools in osteoporosis treatment because of their usefulness of understanding current bone metabolic status, early judgment of osteoporosis treatment and their possibilities in the evaluation of fracture risk. It is important that we utilize bone metabolic markers for osteoporosis treatment in combination with the measurement of bone mineral density and the evaluation of fractures by X-ray photograph.

Fluorescence bronchoscopy in the detection of preinvasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy

BACKGROUND

A new strategy in the treatment of squamous cell carcinoma of the tracheobronchial tree is the detection and eradication of preinvasive bronchial lesions before they become invasive cancers. It is, however, difficult to detect preinvasive lesions by conventional white-light bronchoscopy alone.

PURPOSE

we conducted a detailed investigation on the use of fluorescence bronchoscopy in the detection of preinvasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy.

METHODS

64 participants with sputum cytology suspicious or positive for malignancy were examined with both white light and fluorescence bronchoscopy (LIFE group). Earlier to this study, before fluorescence bronchoscopy became available in our institute, 48 participants having sputum cytology suspicious or positive for malignancy were examined with white light bronchoscopy alone (control group). Biopsy specimens for pathological examinations were taken of all abnormal areas discovered by white light or fluorescence bronchoscopy examination.

RESULTS

In sputum cytology suspicious or positive for malignancy, the diagnosis of preinvasive bronchial lesions was greatly enhanced in the LIFE group as compared with the control group (45 vs. 7 lesions). The percentage of participants with preinvasive bronchial lesions was also significantly higher in the LIFE group than in the control group (40.6 vs. 12.5%, P = 0.00087, respectively).

CONCLUSIONS

Our study suggests that the use of fluorescence bronchoscopy in addition to conventional white-light examination could greatly enhance the detection and localization of preinvasive bronchial lesions in patients with sputum cytology suspicious or positive for malignancy.

Cell-free entry of human T-cell leukemia virus type 1 to mouse cells

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia and HTLV-1-associated myelopathy / tropical spastic paraparesis. Recently we infected newborn mice by inoculating HTLV-1-producing human cells, and found that T-cells, B-cells and granulocytes were infected in vivo. To understand the mechanism of viral-cell interaction and the pathogenesis of HTLV-1 using the mouse model, it is important to clarify the cellular tropism using a cell-free HTLV-1 transmission system. We employed a highly transmissible cell-free HTLV-1 produced by a feline kidney cell line, c77, and studied the susceptibility of 9 kinds of mouse cell lines, EL4, RLm1, CTLL-2, J774.1, DA-1, Ba / F3, WEHI-3, NIH3T3 and B1, and two kinds of human cell lines, Molt-4 and Hut78. HTLV-1 proviral sequence was found by PCR in all 9 mouse cell lines as well as in 2 human cell lines and viral entry was blocked with sera from an HTLV-1 carrier and an adult T-cell leukemia patient. Unexpectedly, mouse cell lines EL4 and RLm1 and human cell lines Molt-4 and Hut78 showed similar efficiency for viral entry. These results suggest a wide distribution of HTLV-1 receptor in mouse cells.

Local structure of silver clusters in the channels of zeolite 4A

The Ag K-edge EXAFS measurements have been carried out at 50 K for fully Ag+-exchanged zeolite 4A (Ag-4A) dehydrated at different temperatures under vacuum. In the Fourier transforms of the EXAFS oscillation the two distinct peaks appear around 2.2 A and 3.0 A, and a shoulder around 2.8 A. The structural parameters (distance, coordination number and root mean square displacement) were derived by a three-shell (two Ag-O contacts and Ag-Ag contact) curve-fitting analysis. It is found that a silver cluster is formed with Ag-Ag distance 2.82+/-0.02 A and coordination number 4.9+/-0.2. When the silver cluster is formed 6 Ag0 atoms and 8 Ag+ ions are arranged in a cubic closed-packed manner in the cage of the Ag-4A zeolite. The 8 Ag+ ions and 6 Ag0 atoms are confined in the framework of oxygens at distances of 2.28+/-0.02 and 2.88+/-0.02 A, respectively.

CD4-Dependent and CD4-independent utilization of coreceptors by human immunodeficiency viruses type 2 and simian immunodeficiency viruses

More than 10 G protein-coupled receptors (GPCRs) have been reported to act as coreceptors for entry of human and simian immunodeficiency viruses (HIV and SIV). We investigated the utilization of six GPCRs as coreceptors by T-cell-line-adapted HIV-2 strains (CBL-20, CBL-21, CBL-23, GH-1, ROD, and SBL6669) and SIV strains (SIVagmTYO-1, SIVmac251, and SIVmndGB-1). NP-2/CD4 cells were transduced with CCR3, CCR5, CCR8, CXCR4, GPR1, or APJ, and examined for susceptibilities to cell-free HIV/SIV. HIV-2 strains were grouped into two types by their coreceptor usage. The first group, CBL-20 and CBL-21, used CXCR4 exclusively; the other four strains used a few or all of the six coreceptors. These strains could further infect CD4-negative NP-2/CXCR4 or NP-2/CCR5 cells in the presence (all strains) or absence (SBL6669 and ROD strains) of soluble CD4. SIVagm and SIVmnd infected NP-2/CD4/GPR1 cells. The coreceptors CCR3, CCR8, GPR1, and APJ did not mediate the CD4-independent infection. Although HIV-2ROD and SIVmnd infected both NP-2/CD4/CXCR4 and NP-2/CD4/CCR5 cells, only CXCR4 and CCR5, respectively, were used in CD4-independent infection. Binding of virions to CD4-negative cells occurred at 4 degrees C. These findings suggest that there may be a correlation between the promiscuous use of coreceptors by HIV-2/SIV strains and their ability to infect CD4-negative cells.

[Clinical utility of transcription mediated amplification-hybridization protection method(TMA-HPA) for the detection of HBV DNA: a comparison with the branched DNA probe assay]

The clinical utility of the TMA-HPA method for the detection of HBV DNA was evaluated by comparing results with the branched DNA probe(b-DNA) assay. Sera from 135 biopsy-confirmed HBV carriers were included in the study. Dilution tests with two representative sera revealed the sensitivity of the TMA-HPA method to be 100-fold higher than that of the b-DNA assay. Among the 135 test sera, HBV DNA measurements obtained by the two assays showed a high degree of correlation(r = 0.861, p < 0.0001). Of the 72 sera which tested positive for HBe antigen, 71 and 67 were positive for HBV DNA when tested by TMA-HPA and b-DNA assay, respectively. In contrast, of the 63 which tested negative for HBe antigen, 42 were positive for HBV DNA when tested by TMA-HPA, and only 19 were positive when tested by b-DNA assay(p < 0.05). Among HBe antigen-positive HBV carriers, HBV DNA levels as determined both TMA-HPA and b-DNA assay showed an inverse relationship with pathological stage, but among HBe antigen-negative HBV carriers, no such tendency was observed. Based on these results, it is felt that the detection of HBV DNA by TMA-HPA is useful for the evaluating anti-viral therapeutic effect in HBV carriers, and in estimating a prognosis.

Over-expression of p27kip1 induces growth arrest and apoptosis mediated by changes of pRb expression in lung cancer cell lines

p27kip1 is a cyclin-dependent kinase inhibitor which controls the G1 phase of the cell cycle in conjunction with pRb. p27 has been associated with cell-cycle arrest and apoptosis. In this study, we transferred the full-length human p27 cDNA using a replication-deficient recombinant adenoviral vector (Ax-p27) into lung cancer cell lines and evaluated the potential of this strategy for anti-cancer gene therapy. After infection with Ax-p27, the growth of H322, A549 and SQ-5 cells, which express pRb, was almost completely suppressed, though no such effect was found in H69 and Lu-135 cells, which do not express pRb. In addition, cell death from day 4 after infection with Ax-p27 was observed only in H322, A549 and SQ-5 cells but not in H69 and Lu-135 cells. The cell cycle of H322 cells treated with Ax-p27 became arrested at the G1 phase from day 1 to day 3 despite continued over-expression of p27. When we examined the changes in expression level of pRb and E2F-1, which play important roles in cell-cycle progression from G1 to S phase, down-regulation of pRb expression was detected in H322 cells 3 days after infection with Ax-p27. These data suggest that (i) the growth-inhibitory effect and induction of apoptosis by over-expression of p27 require expression of pRb and (ii) adenovirus-mediated p27 gene transfer may have promise as a novel strategy in cancer gene therapy.

Separation selectivity of anionic metal complexes of N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid in ion and ion electrokinetic chromatography

The complexes of Fe(III), Co(III), Mn(III), Al(III), Cu(II), Ni(II), Cd(II) and Zn(II) with N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) were separated by ion exchange in different modes: ion chromatography (IC) and ion electrokinetic chromatography (IEKC). In column IC these complexes were separated on an IonPac AS4a anion-exchange column (Dionex, USA). Parameters of the background electrolyte that were examined in IEKC mode include polymer, competing ion concentration and pH. The use of poly(diallyldimethylammonium chloride) (PDADMACl) as a modifier in IEKC provides separation selectivity only slightly different from that observed in IC on the IonPac AS4a column. Optimal separation conditions were found to be: 0.1 mM HBED, 50 mM PDADMAOH, 10 mM Na2 B4 O7, pH adjusted to 10 with acetic acid. The use of an aromatic ligand allowed a 10-fold decrease in detection limits of metal ions in comparison with previously studied EDTA. A separation efficiency up to 400,000 theoretical plates was demonstrated for IEKC.

Effects of low phosphate intake on bone and mineral metabolism in rats: evaluation by biochemical markers and pyridinium cross-link formation in bone

We have investigated the changes in biochemical markers and in pyridinium cross-links in bone in hypophosphatemic rats. Six-week-old female Wistar rats were divided into two groups (normal diet and a phosphate-deficient diet) and fed for 8 weeks. A low phosphate intake caused a significant difference in the concentrations of osteocalcin and alkaline phosphatase with advancing rachitis as well as an increase in bone resorption marker concentrations in urine. Femur biochemical analysis revealed a significant (p < 0.005) increase in deoxypyridinoline per mole collagen in the phosphate-deficient group which suggested that urinary excretions of pyridinium cross-links might reflect not only bone resorption but also increased pyridinium cross-links in bone matrix collagen. Our results demonstrate that a low phosphate intake causes an increase of pyridinium cross-link formation as well as a discrepancy between the circulation levels of alkaline phosphatase and osteocalcin with advancing rachitis. These alterations induced by low phosphate intake should be considered when interpreting the values of biochemical markers.

The relationship between pentosidine and hemodialysis-related connective tissue disorders

Dialysis-related amyloidosis (DRA), such as destructive spondyloarthropathy (DSA) and carpal tunnel syndrome (CTS), occurs in the connective tissues of patients on long-term hemodialysis (HD). Recently, it was suggested that advanced glycation end products (AGEs) and beta2-microglobulin (beta2m) modified with AGEs are related to DRA. The aim of this study is to elucidate whether serum levels of pentosidine, which is an AGE, relate to the occurrence of DRA in patients with long-term HD. 127 end-stage renal failure patients, with DSA or CTS and undergoing HD, were examined. Serum pentosidine was measured by the HPLC method with column switching. Beta2m and intact parathyroid hormone (i-PTH) were measured. Pentosidine levels were significantly elevated in the DSA, CTS, and DRA groups (patients in the DRA group had either DSA and/or CTS). There were no significant differences in the beta2m and i-PTH levels between any group. The duration of HD did not correlate with either pentosidine or beta2m levels, but did with i-PTH. Receiver-operating characteristic (ROC) analysis was performed to examine the discriminatory ability of pentosidine, beta2m, and i-PTH for DRA. The area under the ROC curve was the greatest for pentosidine. Serum beta2m levels were not related with the occurrence of DRA. The fact that serum pentosidine was higher in DRA than in non-DRA indicates that it has potential as an indicator of the occurrence of DRA in long-term HD patients.

Weekly CODE chemotherapy with recombinant human granulocyte colony-stimulating factor for relapsed or refractory small cell lung cancer

We used cisplatin, vincristine, doxorubicin, and etoposide (CODE) plus recombinant human granulocyte colony-stimulating factor (rhG-CSF) weekly for salvage chemotherapy in relapsed or refractory small cell lung cancer (SCLC). We reviewed the medical charts of patients between January 1993 and December 1996 at the National Nishi-Gunma Hospital. Twenty patients were treated with salvage chemotherapy. The overall response rate was 55.0%. The median survival time of extensive disease patients from the start of CODE therapy was 23 weeks and the 1-year survival rate was 21.0%. Toxicities were severe, especially in myelosuppression. CODE could be selected as a salvage therapy for chemotherapy- relapsed SCLC cases.

[Estimation of sympathetic skin response using DC servo-amplifier]

The aims of this paper are to make clear the characteristics of sympathetic skin response(SSR) wave. The records of SSR wave were obtained using a DC servo-amplifier with the frequency response of DC to 30 Hz and drift level of 10 microV/10 min. The SSR from the palm of 10 normal control subjects(6 males and 4 females, age range 21-25 yrs) were elicited by electrical stimulation of the median nerve at upper arm. The results that the peak latency and the duration of SSR were approximately 6.32 +/- 2.5 s and 47.5 +/- 7.5 s respectively were obtained experimentally with the amplifier, though the results of AC recordings with time constant of 0.3 s were about 1.0 s and 2.0 s respectively. It can be considered that exact peak latency and duration of SSR are much longer than those data of previous studies. These findings suggest that electric stimulation should be applied at longer intervals than 60 s for rejection of the remaining potential level of SSR and the habituation.

Potential of ethylenediaminedi(o-hydroxyphenylacetic acid) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid for the determination of metal ions by capillary electrophoresis

Two aromatic polyaminocarboxylate ligands, ethylenediaminedi(o-hydroxyphenylacetic acid) (EDDHA) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED), were applied for the separation of transition and heavy metal ions by the ion-exchange variant of electrokinetic chromatography. EDDHA structure contains two chiral carbon centers. It makes it impossible to use the commercially available ligand. All the studied metal ions showed two peaks, which correspond to meso and rac forms of the ligand. The separation of metal-HBED chelates was performed using poly(diallyldimethylammonium) polycations in mixed acetate-hydroxide form. Simultaneous separation of nine single- and nine double-charged HBED chelates, including In(III), Ga(III), Co(II)-(III) and Mn(II)-(III) pairs demonstrated the efficiency of 40,000-400,000 theoretical plates. The separation of Co(III), Fe(III) complexes with different arrangements of donor groups and oxidation of Co(II), Mn(H), Fe(II) ions in reaction with HBED have been discussed.

Infection of mesangial cells with HIV and SIV: identification of GPR1 as a coreceptor

BACKGROUND

Mesangial cells are an important component of the glomerulus. Dysfunction of mesangial cells is thought to be involved in the development of human immunodeficiency virus type 1 (HIV-1)-associated nephropathy (HIVAN). HIVAN is a structural renal failure frequently observed in patients with acquired immune deficiency syndrome. However, the susceptibility of mesangial cells to HIV-1 is disputable. More than ten G protein-coupled receptors, including chemokine receptors, have been shown to act as HIV-1 coreceptors that determine the susceptibilities of cells to HIV-1 strains with specific cell tropisms.

METHODS

We examined the susceptibility of mesangial cells to various HIV-1, HIV type 2 (HIV-2) and simian immunodeficiency virus (SIV) strains. Expression of CD4 and HIV/SIV coreceptors was examined by Western blotting and polymerase chain reaction.

RESULTS

Mesangial cells were found to be susceptible to HIV-1 variant and mutants that infect brain-derived cells, but highly resistant to T-tropic (X4), M-tropic (R5) or dual-tropic (X4R5) HIV-1 strains. In addition, mesangial cells were also susceptible to HIV-2 and SIV strains that infect the brain-derived cells. Among HIV/SIV coreceptors we tested, the expression of GPR1 mRNA was detected in mesangial cells. Expression of CD4 mRNA and protein was also detected in them. Mesangial cells and GPR1-transduced CD4-positive cells showed similar susceptibilities to the HIV-1 variant and mutants and HIV-2 and SIV strains.

CONCLUSIONS

CD4 and GPR1 mRNAs were detected in mesangial cells. Mesangial cells were susceptible to HIV/SIV strains that use GPR1 as a coreceptor. Our findings suggest that an orphan G protein-coupled receptor, GPR1, is a coreceptor expressed in mesangial cells. It remains to be investigated whether the interaction of mesangial cells with specific HIV-1 strains through GPR1 plays a role in the development of HIVAN.

Rapid tumor formation and development of neutrophilia and splenomegaly in nude mice transplanted with human cells expressing human T cell leukemia virus type I or Tax1

Human T cell leukemia virus type I (HTLV-I) or its transcriptional transactivator, Tax1, was introduced into a human osteosarcoma cell line, HOS, and a Moloney murine sarcoma virus-positive HOS cell line, S+L-HOS. These HTLV-I- or Tax1-expressing cells were injected subcutaneously into nude mice to investigate the effects of HTLV-I on their tumorigenicities. HOS cells did not form any tumors even in the presence of HTLV-I or Tax1. S+L-HOS cells did form small tumors in two-thirds of nude mice. Infection of S+L-HOS cells with HTLV-I, or transduction of Tax1 into S+L-HOS cells markedly facilitated the tumor formation, and the tumor-bearing mice showed marked splenomegaly and neutrophilia. Elevated levels of granulocyte colony-stimulating factor (G-CSF) were detected in sera of these mice and also in the culture supernatants of Tax1-expressing human cells, suggesting that G-CSF in the mouse sera was produced by the human cells. In sera of some mice with splenomegaly and neutrophilia, high levels of murine granulocyte-macrophage colony-stimulating factor (mGM-CSF) were observed, suggesting that Tax1 produced by human cells induced mouse cells to produce mGM-CSF. Only S+L-HOS cell lines expressing Tax1 showed high tumorigenicity in nude mice. Thus, this system will be a useful model of tumor formation, splenomegaly and neutrophilia dependent on Tax1.