Determination of anti-virus drug, ganciclovir, in human serum by HPLC with precolumn fluorescence derivatization using phenylglyoxal

A selective and highly sensitive liquid chromatographic method for the determination of ganciclovir (anti-virus drug) in human serum was described. After ganciclovir and acyclovir (internal standard; IS) were extracted with solid-phase extraction cartridge from serum, they were converted into fluorescent derivatives by reaction with phenylglyoxal in a phosphate buffer (pH 5.8) at 20 degrees C for 30 min. The derivatives were separated by reversed-phase column with a mixture of acetonitrile-1 mM phosphate buffer (pH 6.2) (18:82, v/v), and were then detected spectrofluorometrically at 512 nm with excitation at 365 nm. Extraction recoveries were 87.0-91.6% for ganciclovir and 86.8-92.3% for IS. The detection limit for ganciclovir spiked to serum was 5 ng ml-1 serum (306 fmol on column) at a signal-to-noise ratio of three. The accuracy and precision of this method were 7.6% and 5.0% even at low concentration (20 ng ml-1). The within- and between-day variations are lower than 7.6% and 8.1%, respectively.

Parathyroid hormone-related protein-(1-34) inhibits intrinsic pump activity of isolated murine lymph vessels

Parathyroid hormone-related protein (PTHrP) was originally found as a tumor-derived vasoactive factor and has also been known to produce significant relaxation of vascular smooth muscles. Thus effects of PTHrP-(1-34), a PTH receptor-binding domain, on spontaneous lymphatic pump activity was investigated in isolated pressurized lymph vessels of mice. Low concentrations (1 x 10(-10) and 3 x 10(-10) M) of PTHrP-(1-34) dilated lymph vessels and reduced the frequency of pump activity, whereas high concentrations (1 x 10(-9) to 1 x 10(-8) M) of PTHrP-(1-34) caused dilation with cessation of the lymphatic pump activity. N(omega)-nitro-L-arginine methyl ester (L-NAME; 3 x 10(-5) M) but not indomethacin (1 x 10(-5) M) significantly reduced the PTHrP-(1-34)-induced inhibitory responses of the lymphatic pump activity. In the presence of L-NAME (3 x 10(-5) M) and L-arginine (1 x 10(-3) M), the L-NAME-induced inhibition in the PTHrP-(1-34)-mediated responses was significantly reduced. Glibenclamide (1 x 10(-6) M) significantly suppressed the inhibitory responses of the lymphatic pump activity induced by PTHrP-(1-34) and S-nitroso-N-acetyl-penicillamine. The PTHrP-(1-34)-mediated inhibitory responses were significantly reduced by treatment with PTHrP-(7-34) (1 x 10(-7) M). These results suggest that PTHrP-(1-34) inhibits spontaneous pump activity of the isolated lymph vessels via PTH receptors and that production and release of endogenous nitric oxide and activation of ATP-sensitive K(+) channels in the lymph vessels contribute to the PTHrP-(1-34)-mediated inhibitory responses of the lymphatic pump activity.

Morbilliviruses use signaling lymphocyte activation molecules (CD150) as cellular receptors

Morbilliviruses comprise measles virus, canine distemper virus, rinderpest virus, and several other viruses that cause devastating human and animal diseases accompanied by severe immunosuppression and lymphopenia. Recently, we have shown that human signaling lymphocyte activation molecule (SLAM) is a cellular receptor for measles virus. In this study, we examined whether canine distemper and rinderpest viruses also use canine and bovine SLAMs, respectively, as cellular receptors. The Onderstepoort vaccine strain and two B95a (marmoset B cell line)-isolated strains of canine distemper virus caused extensive cytopathic effects in normally resistant CHO (Chinese hamster ovary) cells after expression of canine SLAM. The Ako vaccine strain of rinderpest virus produced strong cytopathic effects in bovine SLAM-expressing CHO cells. The data on entry with vesicular stomatitis virus pseudotypes bearing measles, canine distemper, or rinderpest virus envelope proteins were consistent with development of cytopathic effects in SLAM-expressing CHO cell clones after infection with the respective viruses, confirming that SLAM acts at the virus entry step (as a cellular receptor). Furthermore, most measles, canine distemper, and rinderpest virus strains examined could any use of the human, canine, and bovine SLAMs to infect cells. Our findings suggest that the use of SLAM as a cellular receptor may be a property common to most, if not all, morbilliviruses and explain the lymphotropism and immunosuppressive nature of morbilliviruses.

Synthesis and antifungal activities of novel 1,3-beta-D-glucan synthase inhibitors. Part 2

Highly potent 1,3-beta-D-glucan synthase inhibitors, 7b, 10a, 10b and 12, have been identified by the chemical modification of the ornithine residue of a fungicidal macrocyclic lipopeptidolactone, RO-09-3655 (1), isolated from the cultured broth of Deuteromycotinia spp. These compounds showed stronger antifungal activity against systemic candidiasis as well as pulmonary aspergillosis in mice, and less hepatotoxicity as compared with 1.

Measles viruses on throat swabs from measles patients use signaling lymphocytic activation molecule (CDw150) but not CD46 as a cellular receptor

Both CD46 and signaling lymphocytic activation molecule (SLAM) have been shown to act as cellular receptors for measles virus (MV). The viruses on throat swabs from nine patients with measles in Japan were titrated on Vero cells stably expressing human SLAM. Samples from all but two patients produced numerous plaques on SLAM-expressing Vero cells, whereas none produced any plaques on Vero cells endogenously expressing CD46. The Edmonston strain of MV, which can use either CD46 or SLAM as a receptor, produced comparable titers on these two types of cells. The results strongly suggest that the viruses in the bodies of measles patients use SLAM but probably not CD46 as a cellular receptor.

Successful treatment for bronchial bleeding from invasive pulmonary metastasis of hepatocellular carcinoma: a case report

Pulmonary metastasis is frequently seen in patients with advanced hepatocellular carcinoma. However, information is limited concerning life-threatening complications and effective treatment of pulmonary metastasis because of the poor prognosis of patients with advanced hepatocellular carcinoma. Recent remarkable progress in detection and treatment of hepatocellular carcinoma has improved prognosis, making management of pulmonary metastasis an important clinical issue. We describe a 68-year-old man with pulmonary metastasis of hepatocellular carcinoma and sudden onset of hemoptysis from bronchial invasion. Transcatheter embolization was performed successfully via the bronchial artery with disappearance of bloody sputum. Peribronchial pulmonary metastasis of hepatocellular carcinoma can cause life-threatening hemoptysis. Transcatheter arterial embolization may be one of therapeutics for hemoptysis from invasive pulmonary metastasis of hepatocellular carcinoma.

Catheter-associated urinary tract infections: impact of catheter materials on their management

Infection associated with an indwelling catheter is a representative type of biofilm infection occurring in the urinary tract. Since the most effective way to control this intractable infection is the prevention of bacterial attachment and subsequent biofilm formation on the catheter, the importance of catheter materials and anti-bacterial coating cannot be underestimated. The difference in the degree of bacterial attachment among standard catheter materials, the efficacy of silver-coating of catheters in preventing infection and the potency and effectiveness of a new lecithin/silver coating are discussed.

A moderate interaction of maltosyl-alpha-cyclodextrin with Caco-2 cells in comparison with the parent cyclodextrin

The cytotoxicity of maltosyl-alpha-cyclodextrin (G2-alpha-CyD) and maltosyl-beta-cyclodextrin (G2-beta-CyD) toward Caco-2 cells was compared with that of natural alpha-cyclodextrin (alpha-CyD), beta-cyclodextrin (beta-CyD) and gamma-cyclodextrin (gamma-CyD). The degree of increase in cytotoxicity was dependent on the CyD's type and the concentration: the cytotoxicity of CyDs at the same concentration increased in the order of gamma-CyD<G2-beta-CyD<G2-alpha-CyD<<alpha-CyD, although beta-CyD could not be compared to other CyDs because of low solubility in water. Alpha-CyD decreased transepithelial electrical resistance (TEER) and increased the apical-to-basolateral (AP-to-BL) transport of [3H]mannitol, a paracellular transport marker, in a concentration-dependent manner, suggesting that alpha-CyD decreased the integrity of Caco-2 cell monolayers. In addition, alpha-CyD increased the AP-to-BL transport of rhodamine 123, a transcellular transport marker, under the experimental conditions being independent of P-glycoprotein. In contrast, G2-alpha-CyD, G2-betaCyD and gamma-CyD had slight effect on both TEER and the transport of mannitol and rhodamine 123 even at relatively high concentrations up to 150 mM. The inability of G2-alpha-CyD and G2-beta-CyD to effect TEER and the transport of mannitol and rhodamine 123 could be explained by the findings that these maltosylated CyDs released only a small amount of membrane constituents from Caco-2 cell monolayers and interacted only weakly with monolayers composed of L-alpha-dipalmitoylphosphatidylcholine (DPPC) formed on water. These results indicate that G2-alpha-CyD has less cytotoxicity and less disturbing ability toward Caco-2 cell monolayers than alpha-CyD, and G2-beta-CyD has, at least, comparable cytotoxicity to beta-CyD toward them. Thus, from the safety point of view, highly water-soluble G2-alpha-CyD and G2-beta-CyD may be particularly useful in various pharmaceutical formulations.

Oxidative stress in childhood meningitis: measurement of 8-hydroxy-2'-deoxyguanosine concentration in cerebrospinal fluid

To examine the involvement of reactive oxygen species, we measured the concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative stress, in cerebrospinal fluid samples from 63 children with and without meningitis. We observed that the mean concentration of 8-OHdG in samples obtained during the early phase of bacterial meningitis, but not aseptic meningitis, was significantly higher than that in control samples. Clinical and laboratory improvement was associated with a fall in the 8-OHdG concentration in the patients with bacterial meningitis. Our findings suggest the presence of enhanced oxidative stress in the central nervous system of children with bacterial meningitis.

V domain of human SLAM (CDw150) is essential for its function as a measles virus receptor

Human signaling lymphocytic activation molecule (SLAM; also known as CDw150) has been shown to be a cellular receptor for measles virus (MV). Chinese hamster ovary cells transfected with a mouse SLAM cDNA were not susceptible to MV and the vesicular stomatitis virus pseudotype bearing MV envelope proteins alone, indicating that mouse SLAM cannot act as an MV receptor. To determine the functional domain of the receptor, we tested the abilities of several chimeric SLAM proteins to function as MV receptors. The ectodomain of SLAM comprises the two immunoglobulin superfamily domains (V and C2). Various chimeric transmembrane proteins possessing the V domain of human SLAM were able to act as MV receptors, whereas a chimera consisting of human SLAM containing the mouse V domain instead of the human V domain no longer acted as a receptor. To examine the interaction between SLAM and MV envelope proteins, recombinant soluble forms of SLAM were produced. The soluble molecules possessing the V domain of human SLAM were shown to bind to cells expressing the MV hemagglutinin (H) protein but not to cells expressing the MV fusion protein or irrelevant envelope proteins. These results indicate that the V domain of human SLAM is necessary and sufficient to interact with the MV H protein and allow MV entry.

Analysis of the phase solubility diagram of a phenacetin/competitor/beta-cyclodextrin ternary system, involving competitive inclusion complexation

The competitive inclusion complexations in the ternary phenacetin/competitors/beta-cyclodextrin (beta-CyD) systems were investigated by the solubility method, where m-bromobenzoic acid (m-BBA) and o-toluic acid (o-TA) were used as competitors. The solubility changes of the drug and competitors as a function of beta-CyD concentration in the ternary systems were formulated using their stability constants and intrinsic solubilities. The decrease in solubility of phenacetin by the addition of competitors could be quantitatively simulated by the formulation, when both drug and competitor give A(L) type solubility diagrams. On the other hand, when one of the guests gives a B(S) type solubility diagram, its solubility change was clearly reflected in that of the another guest, i.e., phenacetin gave an A(L) type solubility diagram in the binary phenacetin/beta-CyD system and o-TA gave a B(S) type diagram in the binary o-TA/beta-CyD system, but in the ternary phenacetin/o-TA/beta-CyD system, a new plateau region appeared in the original A(L) type diagram of phenacetin. This was explained by the solubilization theory of Higuchi and Connors. The solubility analysis of the ternary drug/competitor/CyD systems may be particularly useful for determination of the stability constant of a drug whose physicochemical and spectroscopic analyses are difficult, because they can be calculated by monitoring the solubility change of a competitor, without monitoring that of a drug. Furthermore, the present results suggest that attention should be paid to the type of the phase solubility diagram, as well as the magnitude of the stability constant and the solubility of the complex, for a rational formulation design of CyD complexes.

Release of plasminogen activator inhibitor-1 from human astrocytes is regulated by intracellular ceramide

The present study underscores a regulatory role of intracellular ceramide in astrocytes for the release of an extracellular serine protease, tissue-type plasminogen activator (t-PA), and its inhibitor, plasminogen activator inhibitor-1 (PAI-1). Treatment of cultured human astrocytes with N-acetylsphingosine, a cell-permeable short-chain ceramide analogue or daunorubicin that could increase intracellular ceramide via activation of ceramide synthase or sphingomyelin hydrolysis increased the release of t-PA and conversely decreased the PAI-1 release. Interestingly, treatment of the astrocytes with tumor necrosis factor (TNF)-alpha also increased the intracellular ceramide levels but caused the elevation of PAI-1 release without altering the t-PA release. These data suggest that the generation of ceramide in astrocytes is linked at least with the regulation of PAI-1 release. We also demonstrate that the suppression of PAI-1 release with daunorubicin accelerates the cell death of neuronally differentiated PC12 cells and suggest an antiapoptotic role of PAI-1 in the nervous system.

Self-maintenance and self-reproduction in an abstract cell model

Living cells must maintain their membranes by active metabolism. The membrane is not static but a dynamic structure that has evolved along with its internal reactions. When we reflect on the emergence and evolution of primitive cells, we should not forget the mutual dependency between membranes and metabolic cycles inside the cell. In this paper, we present a simple abstract model of the self-maintaining cell. A metabolic cycle will produce a self-assembling membrane that will enclose the metabolic cycle. We show that a self-maintaining cell has the potential to reproduce itself spontaneously. Further, we have demonstrated two different ways of cellular reproduction depending on the mobility of chemicals. In the first case, a cell releases autocatalytic chemicals that create new cells outside the mother cell. In the second case, a cell grows larger and divides itself into daughter cells by creating a new internal dividing membrane.

SLAM (CDw150) is a cellular receptor for measles virus

Measles virus continues to be a major killer of children, claiming roughly one million lives a year. Measles virus infection causes profound immunosuppression, which makes measles patients susceptible to secondary infections accounting for high morbidity and mortality. The Edmonston strain of measles virus, and vaccine strains derived from it, use as a cellular receptor human CD46 (refs 3, 4), which is expressed on all nucleated cells; however, most clinical isolates of measles virus cannot use CD46 as a receptor. Here we show that human SLAM (signalling lymphocyte-activation molecule; also known as CDw150), a recently discovered membrane glycoprotein expressed on some T and B cells, is a cellular receptor for measles virus, including the Edmonston strain. Transfection with a human SLAM complementary DNA enables non-susceptible cell lines to bind measles virus, support measles virus replication and develop cytopathic effects. The distribution of SLAM on various cell lines is consistent with their susceptibility to clinical isolates of measles virus. The identification of SLAM as a receptor for measles virus opens the way to a better understanding of the pathogenesis of measles virus infection, especially the immunosuppression induced by measles virus.

Lung abscess caused by Paecilomyces lilacinus

We report the case of a 57-year-old man who was referred to our department for further investigation of an abnormal chest shadow. Radiography on admission demonstrated a coin lesion in the right hilum. To make a final diagnosis, right middle lobectomy was performed and the mass was revealed to be a fungal abscess. Further examination confirmed that the fungus was Paecilomyces lilacinus. This is the first reported case of lung abscess caused by P. lilacinus in an otherwise healthy person.

Different turnover rate of hepatitis C virus clearance by different treatment regimen using interferon-beta

BACKGROUND/AIM

Since patients with high viral load and HCV subtype 1b are known to respond poorly to interferon (IFN) therapy, the viral dynamics of HCV RNA after initiation of interferon therapy were examined in the present study with respect to two different administration regimens, once vs. twice a day.

METHODS

Twenty-two patients with chronic hepatitis C confirmed by liver biopsy and with >1 Meq/ml of HCV RNA and HCV subtype 1b were randomly assigned to two different IFN administration regimens (6 million units of IFN once a day or 3 million units of IFN twice a day), and the serum HCV RNA level was serially measured.

RESULTS

Graphs of HCV RNA levels vs. treatment time showed an initial rapid fall, followed by a slower clearance phase. Fitting the data to a model for HCV decay proposed by Neumann et al. showed that the treatment efficacy was significantly higher with twice daily administration. Negativity for HCV RNA measured by Amplicor assay in the twice-a-day administration group was 18%, 73% and >89% at 1, 2 and 3 weeks, respectively, in contrast to 0%, 0%, and 18%, respectively, with once-a-day administration. However, a significant reduction of platelet count and albumin level, a marked increase in serum aspartate aminotransferase/alanine aminotransferase, and a high incidence of renal toxicity (proteinuria) were found in patients receiving IFN twice a day in comparison with those receiving it once a day.

CONCLUSION

The twice-a-day administration of IFN accelerated the clearance of HCV RNA from serum, leading to a more efficient virological response for patients with chronic hepatitis C, but with a high rate of renal toxicity.

Virus entry is a major determinant of cell tropism of Edmonston and wild-type strains of measles virus as revealed by vesicular stomatitis virus pseudotypes bearing their envelope proteins

The Edmonston strain of measles virus (MV) that utilizes the human CD46 as the cellular receptor produced cytopathic effects (CPE) in all of the primate cell lines examined. In contrast, the wild-type MV strains isolated in a marmoset B-cell line B95a (the KA and Ichinose strains) replicated and produced CPE in some but not all of the primate lymphoid cell lines. To determine the mechanism underlying this difference in cell tropism, we used a recently developed recombinant vesicular stomatitis virus (VSV) containing as a reporter the green fluorescent protein gene in lieu of the VSV G protein gene (VSVDeltaG*). MV glycoproteins were efficiently incorporated into VSVDeltaG*, producing the VSV pseudotypes. VSVDeltaG* complemented with VSV G protein efficiently infected all of the cell lines tested. The VSV pseudotype bearing the Edmonston hemagglutinin (H) and fusion (F) protein (VSVDeltaG*-EdHF) infected all cell lines in which the Edmonston strain caused CPE, including the rodent cell lines to which the human CD46 gene was stably transfected. The pseudotype bearing the wild-type KA H protein and Edmonston F protein (VSVDeltaG*-KAHF) infected all lymphoid cell lines in which the wild-type MV strains caused CPE as efficiently as VSVDeltaG*-EdHF, but it did not infect any of the cell lines resistant to infection with the KA strain. The results indicate that the difference in cell tropism between these MV strains was largely determined by virus entry, in which the H proteins of respective MV strains play a decisive role.

[Basic study on anti-bacterial urethral catheter. II. Potency of a new anti-bacterial catheter and its durability in experimental models]

The potency and effectiveness of an anti-bacterial catheter coated with a mixture of silver citrate, soybean lecithin and liquid silicon at the ratio of 2:2:8 were compared with those of commercially available anti-bacterial and conventional urethral catheters. This new anti-bacterial catheter showed a strong activity and excellent durability in ordinary in vitro experimental studies. In the present series we have developed new in vitro experimental models for the evaluation of anti-bacterial catheters in inhibiting bacterial ascent via intraluminal or extraluminal route. The characteristic features of the silver citrate/lecithin catheter, namely strong activity and excellent durability, were confirmed using these new models that mimic urinary catheter-associated clinical infections.

[Basic study on anti-bacterial urethral catheter. I. Development of a new anti-bacterial coating material for silicon catheters]

In order to develop a new anti-bacterial urethral catheter, we studied anti-bacterial and anti-adherent coating material suitable for silicon catheters. Several aspects of various silver compounds were examined, including anti-bacterial activity, chemical property and toxicity. Among silver citrate, silver phosphate and silver oxide, which were found to have excellent anti-bacterial activities, silver citrate was regarded as the material of choice for anti-bacterial coating in terms of durable activity and biological safety. It was also found that several surfactants inhibited bacterial adherence to the surface of silicon catheters. Among them soybean lecithin exhibited excellent anti-adherent activity in a dose dependent manner. Finally, a mixture of silver citrate, soybean lecithin and liquid silicon at the ratio of 2:2:8 was regarded as an ideal anti-bacterial coating material for silicon catheters.

Avoidance of bone marrow suppression using A-5021 as a nucleoside analog for retrovirus-mediated herpes simplex virus type I thymidine kinase gene therapy

Gene therapy using the herpes simplex virus thymidine kinase (HSV-TK) gene combined with an anti-herpes drug, ganciclovir (GCV), has been applied for human diseases, especially for cancer treatment. However, bone marrow toxicity has been the most consistent adverse effect of GCV treatment in clinical settings. We evaluated the cytotoxic activity of a novel guanosine analog, (1'S,2'R)-9[[1',2'-bis(hydroxymethyl)cycloprop-1'-yl]methyl]guanin e (A-5021), against retrovirus-mediated HSV-TK gene-transduced human lung cancer cells. The bone marrow toxicity of A-5021 and GCV was studied by colony formation assay in both rodent and human bone marrow specimens. We demonstrated that A-5021 had potent cytotoxic activity equal to that of GCV against the retroviral vector-mediated HSV-TK gene-transduced lung cancer cell lines. Further, phosphorylated A-5021 could be transferred to neighboring cells, and this analog killed HSV-TK- neighboring cells, as was the case for GCV. In contrast, A-5021 did not exhibit an inhibitory effect on bone marrow progenitor cells and colony formation (the 50% inhibitory concentration of the colony-forming units in culture = >100 microg/mL in human bone marrow specimens and >66 microg/mL in rodent bone marrow specimens). These results indicate that A-5021 has potent cytotoxic activity as a nucleoside analog for gene therapy using HSV-TK gene, and can be used much more safely than GCV.

[Second reconstructions after failure of free-tissue transfer in the head and neck region]

A retrospective study was performed on 74 patients seen in our hospital between 1990 and 1999 who underwent head and neck reconstructive surgery involving a free flap. Reconstructive surgery was unsuccessful in 5 cases (6.8%). A pedicled myocutaneus flap was used in two cases for the second reconstruction attempt, while a second free flap (jejunum) was used in two other patients. In these cases, a bilateral neck dissection was performed prior to the second free flap reconstruction and neck infection was found. The head and neck artery and vein were unsuitable as recipient vessels in the second operation. Instead, the cephalic vein was used as a source of vein grafts and as a recipient vein.

A simultaneous monitoring of Lens culinaris agglutinin A-reactive alpha-fetoprotein and des-gamma-carboxy prothrombin as an early diagnosis of hepatocellular carcinoma in the follow-up of cirrhotic patients

To elucidate the risk factors for developing hepatocellular carcinoma (HCC) during the follow-up of patients with liver cirrhosis (LC), outpatients with LC were examined periodically by means of serum biochemical assessments, ultrasonography, and computed tomography. Risk factors for HCC were statistically analyzed. We also examined an efficacy of Lens culinaris agglutinin A-reactive profiles of alpha-fetoprotein (AFP-L3%) and des-gamma-carboxy prothrombin (DCP) value using a highly sensitive DCP determination kit (ED036) for the early recognition of HCC. The AFP-L3% and the ED036 value were retrospectively determined with stored serum samples. HCC was diagnosed in 21 of the 78 patients with LC during the follow-up period (mean follow-up period: 42 months). The estimated cumulative incidence of HCC was 25% with 3 years and 48% with 5 years. The most significant risk factor for the development of HCC in LC patients was found to be the mean serum AFP concentration from the year before the HCC detection (p=0.02). At the time of the recognition of HCC, the positive rates of the tumor markers were: serum AFP concentration 14%, serum DCP value 5%, AFP-L3% was 33%, and that of ED036 43%. The positive rate in collaborative use of AFP-L3% and ED036 was 67%. The simultaneous determination of the AFP-L3% and the ED036 value was shown to be effective for the early detection of HCC.