The geography of kidney transplantation in the United States.

The distance kidney transplant patients live from the centers where they undergo transplantation could affect long-term care and outcomes, but little is known about this distance and its associations. We used data from the United States Renal Data System to examine distance between home and transplant center for 92 224 adults undergoing kidney transplantation in 1995-2003. The 5th, 25th, 50th, 75th and 95th percentiles for distances were 2.4, 8.4, 23.0, 67.3 and 213.7 miles, respectively. Compared to whites (median distance 28.5 miles), African Americans (11.5 miles) and Asians (13.5 miles) lived closer to their centers, while Native Americans lived farther away (90.1 miles). Hispanics lived closer (14.7 miles) than non-Hispanics (24.3 miles). Even after adjusting for center density, we found substantial regional variability, with median distance of 15.1 miles for patients living in the Northeast and 40.6 miles for those in the Southeast. Distance was also associated with center size, median zip code income, listing on more than one deceased-donor waiting list and other factors, but greater distance (adjusted for these other factors) was not associated with worse patient or graft survival. The substantial variability in geographical access to kidney transplantation could have important implications for long-term care.

Hyperlipidemia following treatment with antipsychotic medications.

OBJECTIVE: This study attempted to estimate the relative risk of developing hyperlipidemia after treatment with antipsychotics in relation to no antipsychotic treatment. METHOD: A matched case-control analysis was performed with pharmacy and claims data from California Medicaid (Medi-Cal). Patients were excluded if they were treated for medical disorders or prescribed medications known to increase their risk of hyperlipidemia. Cases were ages 18 to 64 years with schizophrenia, major depression, bipolar disorder, or other affective psychoses and incident hyperlipidemia. Cases were matched to up to six control subjects by age, sex, race, and psychiatric diagnosis. Both groups were prescribed either no antipsychotic medication or had two or more prescriptions for one and only one antipsychotic medication during the 60 days prior to the first indication of hyperlipidemia (cases) or matched index date (controls) in the billing record. Conditional logistic regressions were used to derive odds ratios and 95% confidence intervals (95% CIs) of each antipsychotic medication in relation to no antipsychotic medication. RESULTS: A total of 13,133 incident cases of hyperlipidemia were matched to 72,140 control subjects. As compared with no antipsychotic medication, treatment with clozapine (odds ratio: 1.82, 95% CI: 1.61-2.05), risperidone (odds ratio: 1.53, 95% CI: 1.43-1.64), quetiapine (odds ratio: 1.52, 95% CI: 1.40-1.65), olanzapine (odds ratio: 1.56, 95% CI: 1.47-1.67), ziprasidone (odds ratio: 1.40, 95% CI: 1.19-1.65), and first-generation antipsychotics (odds ratio: 1.26, 95% CI: 1.14-1.39), but not aripiprazole (odds ratio: 1.19, 95% CI: 0.94-1.52) was associated with a significant increase in risk of incident hyperlipidemia. CONCLUSIONS: These findings suggest that most commonly prescribed antipsychotic medications increase the risk of developing hyperlipidemia in patients with schizophrenia or mood disorders.

Lobucavir is phosphorylated in human cytomegalovirus-infected and -uninfected cells and inhibits the viral DNA polymerase.

Lobucavir (LBV) is a deoxyguanine nucleoside analog with broad-spectrum antiviral activity. LBV was previously shown to inhibit herpes simplex virus (HSV) DNA polymerase after phosphorylation by the HSV thymidine kinase. Here we determined the mechanism of action of LBV against human cytomegalovirus (HCMV). LBV inhibited HCMV DNA synthesis to a degree comparable to that of ganciclovir (GCV), a drug known to target the viral DNA polymerase. The expression of late proteins and RNA, dependent on viral DNA synthesis, was also inhibited by LBV. Immediate-early and early HCMV gene expression was unaffected, suggesting that LBV acts temporally coincident with HCMV DNA synthesis and not through cytotoxicity. In vitro, the triphosphate of LBV was a potent inhibitor of HCMV DNA polymerase with a Ki of 5 nM. LBV was phosphorylated to its triphosphate form intracellularly in both infected and uninfected cells, with phosphorylated metabolite levels two- to threefold higher in infected cells. GCV-resistant HCMV isolates, with deficient GCV phosphorylation due to mutations in the UL97 protein kinase, remained sensitive to LBV. Overall, these results suggest that LBV-triphosphate halts HCMV DNA replication by inhibiting the viral DNA polymerase and that LBV phosphorylation can occur in the absence of viral factors including the UL97 protein kinase. Furthermore, LBV may be effective in the treatment of GCV-resistant HCMV.

Bisubstrate inhibitors of farnesyltransferase: a novel class of specific inhibitors of ras transformed cells.

We describe the biological properties of a new class of potent farnesyltransferase (FT) inhibitors designed as bisubstrate analog inhibitors. These inhibitors incorporate the structural motifs of both farnesyl pyrophosphate and the CAAX tetrapeptide, the two substrates of the reaction catalyzed by FT. Both the phosphinate inhibitor, BMS-185878, and the phosphonate inhibitor, BMS-184467, exhibited higher in vitro FT selectivity than some of the previously reported CVFM peptidomimentics and benzodiazepine analogs. Xenopus oocyte maturation induced by microinjected oncogenic Ras proteins was blocked by coinjected BMS-184467 and BMS-185878. However, both inhibitors showed poor cell activity presumably because of the doubly charged nature of the compounds. Thus, masking the charge on the carboxylate ion markedly improved the cell permeability of BMS-185878, leading to BMS-186511, the methyl carboxyl ester prodrug. BMS-186511 inhibited FT activity in whole cells as determined by inhibition of p21 Ras protein processing, inhibition of farnesylation of proteins including Ras and the accumulation of unfarnesylated Ras proteins in the cytosolic fraction. While the cellular effects of these bisubstrate analog inhibitors had no significant effect on growth of untransformed NIH3T3 cells, they produced pronounced inhibition of Ras transformed cell growth. Both the anchorage dependent and independent growth of ras transformed cells were severely curtailed by micromolar concentrations of BMS-186511. We also found that both H-ras and K-ras transformed cells are affected by this bisubstrate inhibitor. However, K-ras transformed cells appear to be less sensitive. The inhibition of FT activity in cells and the ensuing inhibition of ras transformed cell growth is further manifested in distinct morphological changes in cells. Cells flattened, became less refractile and grew in contact inhibited monolayer. Moreover, the highly diffused character of the actin cytoskeleton in the ras transformed cells was dramatically reverted to an organized network of stress cables crisscrossing the entire cells upon treatment with BMS-186511. All of these effects of BMS-186511 are limited to ras transformed cells that utilize farnesylated Ras, but are not seen in transformed cells that use geranylgeranyl Ras or myristoyl Ras. Significantly, these FT inhibitors did not produce any signs of gross cytotoxicity in untransformed, ras transformed cells or other oncogene transformed cells.

Synthesis and antiviral activity of 1-cyclobutyl-5-(2-bromovinyl)uracil nucleoside analogues and related compounds.

A series of racemic (1 alpha (E), 2 beta, 3 alpha)-1-[2,3-bis(hydroxymethyl)cyclobutyl]-5-(2-halovinyl)uracils was synthesized and evaluated in cell culture. The bromovinyl, iodovinyl, and chlorovinyl analogues, 13, 15, and 16, respectively, are all potent inhibitors of varicella zoster virus (VZV), but are less inhibitory to the replication of human cytomegalovirus (HCMV) and herpes simplex viruses 1 and 2 (HSV-1, HSV-2). The excellent anti-VZV activities of 13, 15, and 16 coupled with their virtual inability to inhibit WI-38 cell growth indicate high in vitro therapeutic indices. VZV thymidine kinase readily converts these compounds to their respective monophosphates but not to their corresponding diphosphates. Compound 13a, the (1'R) enantiomer of the bromovinyl analogue 13, was also synthesized, and its potency is comparable to that of the racemate. A lower homologue 14, (1 alpha (E),2 beta, 3 alpha)-1-[2-hydroxy-3-(hydroxymethyl)cyclobutyl]-5- (2-bromovinyl)uracil, was found to be inactive against VZV, HCMV, HSV-1, and HSV-2.

Oral bioavailability and anti-simian varicella virus efficacy of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (BV-araU) in monkeys.

BV-araU (1-beta-D-arabinofuranosyl-E-5-[2-bromovinyl]uracil) has potent antiviral activity against varicella zoster virus in cell culture and is undergoing clinical evaluation. In the present study, pharmacokinetic parameters and the efficacy of BV-araU against infection with simian varicella virus (SVV) were evaluated in African green monkeys. Pharmacokinetic parameters were determined by analysis of the BV-araU content of sera obtained after oral and intravenous administration to normal monkeys. Peak serum concentrations showed dose proportionality, with the 0.1 mg/kg dose resulting in a peak serum concentration of 0.05 micrograms/ml, the approximately ED50 value for the SVV inoculum in cell culture. BV-araU administered orally twice daily at 0.1 mg/kg for 10 days starting 48 h after intratracheal SVV infection prevented vesicular rash development and suppressed viremia. Effective therapy could be initiated 96 h after infection. Taken together, these results indicate that BV-araU is effective oral therapy at doses that achieve peak serum levels equivalent to the ED50 for SVV in cell culture.

Selective activity and cellular pharmacology of (1R-1 alpha,2 beta,3 alpha)-9-[2,3-bis(hydroxymethyl)cyclobutyl]guanine in herpesvirus-infected cells.

The cycloburtane nucleoside analog (1R-1 alpha,2 beta,3 alpha)-9-[2,3-bis(hydroxymethyl)cyclobutyl]guanine [(R)-BHCG or SQ 34,514] was recently synthesized and shown to be the active enantiomer of (+/-)-BHCG (SQ 33,054), a potent inhibitor of several strains of herpesviruses [J. Med. Chem 34:1415-1421 (1991); Antiviral Res. 13:41-52 (1990)]. In plaque reduction assays, (R)-BHCG was about 1000 times more active than its S-enantiomer on herpes simplex virus type I (HSV-1) and over 200 times more active against a thymidine kinase-deficient mutant HSV-1 and human cytomegalovirus (HCMV). We now show that both (R)-BHCG and (S)-BHCG are efficiently phosphorylated to their mono-, di-, and triphosphates by HSV-1-infected cells, in a manner similar to that of acyclovir [Proc. Natl. Acad. Sci. USA 74:5716-5720 (1977)]. The uptake of both enantiomers was greatly increased upon infection; however, (S)-BHCG was taken up to about twice the extent of (R)-BHCG and accumulated primarily as the mono- and diphosphates. (R)-BHCG accumulated primarily as the triphosphate, and accumulation was linear with both time and added drug concentration. The triphosphate had an apparent half-life of about 10 hr. Metabolic studies using HCMV-infected cells showed only a small degree of phosphorylation of (R)-BHCG and none of (S)-BHCG. When cells were labeled with 25 microM (R)-BHCG, the amount of (R)-BHCG triphosphate formed was less than 0.5 pmol/10(6) cells. Interestingly, the ED50 value of (R)-BHCG is about 100-fold higher against HCMV than against HSV-1, and the relative levels of (R)-BHCG triphosphate formed in cells infected by the two viruses are roughly proportional to the antiviral activities.

Evaluation of SQ 34,514: pharmacokinetics and efficacy in experimental herpesvirus infections in mice.

The new antiviral nucleoside SQ 34,514 [(1R-1 alpha, 2 beta, 3 alpha)-2-amino-9- [2,3-bis(hydroxymethyl)cyclobutyl]-6H-purin-6-one], the active R isomer of racemic SQ 33,054 (cyclobut-G), was evaluated for efficacy in the treatment of herpesvirus infections in mice. SQ 34,514 was orally efficacious in a herpes simplex virus type 1 (HSV-1) systemic infection, an intracerebral HSV-2 infection, a vaginally induced HSV-2 infection in ovariectomized mice, and in a systemic murine cytomegalovirus infection. SQ 34,514 compared favorably with acyclovir and ganciclovir in the treatment of these experimental infections. In mice, SQ 34,514 had an oral bioavailability of 80% based on urinary excretion. SQ 34,514 may have potential value in the therapy of HSV and cytomegalovirus infections in humans.

(+-)-(1 alpha,2 beta,3 alpha)-9-[2,3-bis(hydroxymethyl)-cyclobutyl] guanine [(+-)-BHCG or SQ 33,054]: a potent and selective inhibitor of herpesviruses.

(+-)-(1 alpha,2 beta,3 alpha)-9-[2,3-bis(hydroxymethyl)cyclobutyl] guanine [(+-)-BHCG or SQ 33,054] is a newly synthesized nucleoside analog with potent and selective antiviral activity against members of the herpesvirus group, including human cytomegalovirus. The activity against a thymidine kinase deficient HSV-2 mutant was 25-fold poorer than against the parent virus, suggesting that phosphorylation is an important prerequisite for antiviral activity against HSV-2. (+-)-BHCG is readily phosphorylated by purified HSV-1 thymidine kinase, and BHCG triphosphate synthesized enzymatically is a selective inhibitor of HSV-1 DNA polymerase. (+-)-BHCG did not inhibit host cell growth at concentrations at least 1000-fold higher than HSV-2 inhibitory concentrations. Subcutaneous administration of (+-)-BHCG was protective against HSV-1 systemic infections in mice. BHCG is an exciting antiviral agent and represents a new class of nucleoside analogs.

Broad-spectrum antiviral activity of the acyclic guanosine phosphonate (R,S)-HPMPG.

(R,S)-9-(3-hydroxy-2-phosphonomethoxypropyl)guanine [(R,S)-HPMPG] exhibits broad spectrum antiviral activity with an ED50 of less than 1 microM against herpes simplex virus (HSV) types 1 and 2, varicella zoster virus, human cytomegalovirus (HCMV) and vaccinia in plaque reduction assays. Wild type HSV-2 and its thymidine kinase deficient variant are equally sensitive to (R,S)-HPMPG. (R,S)-HPMPG is 100-fold more potent than acyclovir (ED50 = 0.45 microM vs. 44 microM, respectively) against HCMV in cell culture, and 10-fold more active than acyclovir in extending survival time in mice intraperitoneally infected with 70 LD50 HSV-1. However, (R,S)-HPMPG is toxic when administered repeatedly at 44 mg/kg/day in uninfected adult mice. The diphosphoryl derivative of HPMPG was enzymatically synthesized and is a competitive inhibitor of HSV-1 DNA polymerase relative to dGTP (K1 = 0.03 microM). HPMPG-PP is 70-fold less active at inhibiting HeLa DNA polymerase alpha than HSV-1 DNA polymerase. At concentrations between 0.3 and 1.5 microM (R,S)-HPMPG inhibited HSV-1 DNA replication greater than or equal to 50% in infected cells as measured by nucleic acid hybridization. Consistent with inhibition of viral DNA synthesis, 6 to 30 microM (R,S)-HPMPG reduces late viral polypeptide synthesis in HSV-1 infected cells. These data indicate that (R,S)-HPMPG is a thymidine kinase independent broad spectrum antiviral drug which is capable of inhibiting viral DNA polymerase.

Latex immunoassay for rapid detection of rotavirus.

A latex agglutination (LA) test was evaluated for the detection of human rotaviruses in stool specimens. Both antiserum and immunoglobulin G (IgG)-sensitized latex particles were used, with IgG-coated beads being more sensitive for human rotavirus antigen detection. Latex beads sensitized with anti-simian-SA-11 IgG were stable for at least 8 months when stored at 4 degrees C. The sensitivity of the test was compared with that of the Rotazyme (Abbott Laboratories, Diagnostics Div., North Chicago, Ill.) test. The least number of particles detected was 9.0 X 10(5) particles by the LA test versus 4.5 X 10(5) particles by the Rotazyme test. When 10 stool specimens were serially diluted for antigen endpoint determinations, the geometric mean titer by the LA test was 592 versus 1,280 by the Rotazyme test. Forty-three stool samples positive by the Rotazyme test were all positive by the LA test, and no false negative results were detected. Unconfirmed false positive reactions ranged between 8 and 24%. The LA test for rotavirus antigen detection is direct, easy to perform, sensitive, quick, and may have application for use in diagnostic laboratories, emergency rooms, and physician's offices.

Normal and dystrophic embryonic chicken pectoralis muscle cultures: III. Viral infection of normal cell cultures.

Twelve-day normal and dystrophic chick embryo breast muscle cells were cultured for up to 14 days, using normal embryo extract in the culture medium. Fluorodeoxyuridine was added on day 3 to suppress fibroblast overgrowth. Three of 6 experiments with normal cells were severely infected with avian leucosis/sarcoma (ALS) virus particles. The findings appear to lend support to the suggestion that the ALS virus is a mitochondriophage. Infected cultures demonstrated a depressed rate of total protein synthesis as reflected by incorporation of [3H]leucine. Extractable protein and total protein content were also depressed within several days after ALS particles were identified. These findings reinforce caution in acceptance of the common assumption that viral infections are an unavoidable and metabolically benign component of muscle cell cultures.