Gigavalent Display of Proteins on Monodisperse Polyacrylamide Hydrogels as a Versatile Modular Platform for Functional Assays and Protein Engineering

The assembly of robust, modular biological components into complex functional systems is central to synthetic biology. Here, we apply modular "plug and play" design principles to a solid-phase protein display system that facilitates protein purification and functional assays. Specifically, we capture proteins on polyacrylamide hydrogel display beads (PHD beads) made in microfluidic droplet generators. These monodisperse PHD beads are decorated with predefined amounts of anchors, methacrylate-PEG-benzylguanine (BG) and methacrylate-PEG-chloroalkane (CA), that react covalently with SNAP-/Halo-tag fusion proteins, respectively, in a specific, orthogonal, and stable fashion. Anchors, and thus proteins, are distributed throughout the entire bead volume, allowing attachment of ∼10⁹ protein molecules per bead (⌀ 20 μm) -a higher density than achievable with commercial surface-modified beads. We showcase a diverse array of protein modules that enable the secondary capture of proteins, either noncovalently (IgG and SUMO-tag) or covalently (SpyCatcher, SpyTag, SnpCatcher, and SnpTag), in mono- and multivalent display formats. Solid-phase protein binding and enzymatic assays are carried out, and incorporating the photocleavable protein PhoCl enables the controlled release of modules via visible-light irradiation for functional assays in solution. We utilize photocleavage for valency engineering of an anti-TRAIL-R1 scFv, enhancing its apoptosis-inducing potency ∼50-fold through pentamerization.

A New Postharvest Fruit Rot in Apple and Pear Caused by Phacidium lacerum

During surveys for postharvest diseases of apple and pear, an unknown postharvest fruit rot was observed in Washington State. The disease appeared to originate from infection of the stem and calyx tissue of the fruit or wounds on the fruit. An unknown pycnidial fungus was consistently isolated from the decayed fruit. Isolates from apple and pear were characterized and identified by molecular phylogenetic analysis and morphology. Pathogenicity of representative isolates on apple and pear fruit was tested under laboratory or field conditions. A BLAST search in GenBank showed that isolates differed from Phacidium lacerum and its synonym, Ceuthospora pinastri, by only 0 to 4 bp in sequences within part of the combined large ribosomal subunit + internal transcribed spacer + small ribosomal subunit regions. The phylogenetic analysis confirmed the taxonomic placement of the unknown fungus in the genus Phacidium, with the highest match being C. pinastri (formerly anamorphic P. lacerum) and with closely related taxa from GenBank forming congeneric clades. The fungus grew at 0 to 30°C and formed unilocular to multilocular pycnidial conidiomata on artificial media after approximately 5 to 7 days at room temperature. On potato dextrose agar incubated for a 12-h photoperiod, semi-immersed globose to subglobose pycnidial conidiomata were 250 to 1,000 μm in diameter (mean = 350), with 1 to 3 nonpapillate to slightly papillate ostioles and a buff conidial matrix. Conidia produced on phialides were 8 to 13 by 1.5 to 2.5 μm, hyaline, aseptate, cylindrical, with an abruptly tapered, typically slightly protuberant base, 2 to 3 guttules, and sometimes with a mucilaginous, flexuous, unbranched appendage which is attached to the apex of the conidium and disappears with age. Conidiogenous cells were flask shaped and 6 to 15 ×1.5 to 3 μm. Colony characteristics included felt-like aerial white mycelium, gray olivaceous at the center becoming greenish to colorless toward the margin, in concentric rings, with pycnidia forming in 5 to 7 days originating from the center of the plate. Morphological characteristics of the fungus had the greatest conformity with the description for C. pinastri. Based on molecular and morphological data, the fungus is identified as P. lacerum. 'Fuji' apple fruit and 'd'Anjou' pear fruit that were wounded, inoculated with representative isolates, and incubated at 0°C yielded the same symptoms as seen on decayed fruit collected from commercial fruit packinghouses. Stem-end rot, calyx-end rot, and wound-associated rot developed on fruit inoculated in the orchard after 3 months of cold storage. The fungus was reisolated from the diseased fruit. This is the first report of a fruit rot in apple and pear caused by P. lacerum. We propose Phacidium rot as the name of this disease.

Is there any chlorine monoxide in the stratosphere?

A ground-based search for stratospheric chlorine monoxide was carried out during May and October 1981 with an infrared heterodyne spectrometer in the solar absorption mode. Lines due to stratospheric nitric acid and tropospheric carbonyl sulfide were detected at about 0.2 percent absorptance levels, but the expected 0.1 percent lines of chlorine monoxide in this same region were not seen. Stratospheric chlorine monoxide is less abundant by at least a factor of 7 than is indicated by in situ measurements, and the upper limit for the integrated vertical column density of chlorine monoxide is 2.3 x 10(13) molecules per square centimeter at the 95 percent confidence level. These results imply that the release of chlorofluorocarbons may be significantly less important for the destruction of stratospheric ozone than is currently thought.

Methodological innovations in data gathering: newborn screening linkage with live births records, Michigan, 1/2007-3/2008

OBJECTIVE

To match Michigan birth and newborn screening records to identify and follow-up potentially unscreened infants, assess data quality, and demonstrate the utility of Link Plus linkage software for matching MCH related administrative datasets.

METHODS

Birth and newborn screening records maintained by the Michigan Department of Community Health from January 2007 through March 2008 were used in this study. Link Plus, a freely-available probabilistic record linkage software program developed at the Centers for Disease Control and Prevention, was used to match records. Linkage performance was assessed by the linkage success rate (percentage of valid matches). Follow-up of un-matched records was conducted by the Michigan Newborn Screening Follow-up Program.

RESULTS

Nearly all (99.2%) of the 142,178 birth records included in this study were successfully matched to newborn screening records. Following a transition to a web-based electronic birth certificate system and inclusion of a newborn screening card identification number on the birth record in 2008, the linkage success rate increased to 99.6% based on analysis of approximately 18,000 records. Of approximately 600 un-matched records, nearly half had received a newborn screen. Approximately 8% of un-matched records were due to parental refusal of newborn screening. Nine children received an initial screen as a result of this study; one was confirmed as having sickle cell trait.

CONCLUSIONS

We have demonstrated that a freely available record linkage software, Link Plus, can be used to successfully match records of MCH databases thereby providing an opportunity for further research and quality assurance investigations.

Occurrence of Kluyveromyces marxianus var. marxianus Causing Onion Soft Rot in the Columbia Basin of Washington State

Kluyveromyces marxianus var. marxianus, a causal agent of onion (Allium cepa L.) soft rot, was originally isolated from Walla Walla sweet onion bulbs grown in Oregon and subsequently isolated from onion throughout the southeast Washington onion-growing area, but was not found to be infecting dry bulb storage onions grown in central Washington (1). During September of 2001, a yeast was isolated from dry storage onion bulbs (cv. Teton) grown under sprinkler irrigation in central Washington, exhibiting soft rot symptoms and identified to be K. marxianus var. marxianus (2). Koch's postulate was completed using cv. Teton bulbs surface disinfested with 0.5% NaOCl for 2 min. This isolate and four isolates of Kluyveromyces marxianus var. marxianus (1) were cultured on potato dextrose agar and resuspended to an OD₆₀₀ = 0.3 (approximately 10⁵ CFU/ml). One-half of a milliliter of each isolate was inoculated to onion using the cut bulb method with three replicates and incubated in a moist chamber at 25°C for 7 days. Onion slices inoculated with the new isolate exhibited soft rot symptoms similar to those caused by the known isolates while no symptoms were observed for the water control. The yeast reisolated from symptomatic tissue was confirmed to be K. marxianus var. marxianus (2). The identification of K. marxianus var. marxianus infecting dry bulb storage onions grown in the Columbia Basin is of interest because the disease can be confused with bacterial soft rot and could become a serious problem in this important storage onion-growing region. References: (1) D. A. Johnson et al. Plant Dis. 72:359, 1988. (2) N. J. W. Kreger-van Rig, ed. The Yeasts: A Taxonomic Study. Elsevier, Amsterdam, 1984.

Phacidiopycnis washingtonensis--a new species associated with pome fruits from Washington State

A new species of Phacidiopycnis associated with pome fruits is described. The fungus causes fruit rot on apples during storage and is associated with a twig dieback and canker disease of crabapple trees and dead twigs of pear trees. To characterize the biology of the fungus and compare it with Ph. piri, the type species of the genus, effects of nine media and light on mycelial growth and pycnidial production, mycelial growth in response to temperature and mode of conidial germination in response to nutrient were determined. Apple-juice agar, pear-juice agar, prune-juice agar, potato-dextrose agar (PDA) and malt-extract agar, Czapek-Dox agar and oatmeal agar (OMA) favored mycelial growth. Cornmeal agar (CMA) did not favor mycelial growth. Light effect on pycnidial formation was medium dependent. Abundant pycnidia with mature conidia formed in 14 d old PDA and OMA cultures at 20 C, regardless of light, whereas none or very few pycnidia formed on other media in the dark. Fluorescent light stimulated formation of pycnidia except on CMA. The fungus grew at -3-25 C, with optimum growth at 15-20 C. Conidia germinated either by forming germ tubes or less often by budding. Budding of conidia occurred in 1 and 10% pear-juice solutions but not in 100% pear-juice solution. Six isolates of Ph. washingtonensis from different species of pome fruits had identical ITS sequences. The sizes of the ITS region were the same for both Ph. washingtonensis and Ph. piri, and four polymorphic nucleotide sites were found in the ITS region between Ph. washingtonensis and Ph. piri. The similarity in ITS sequences between these two taxa is confirmatory evidence for the erection of the new species of Phacidiopycnis associated with pome fruits we describe here.

Influence of culture media and environmental factors on mycelial growth and pycnidial production of Sphaeropsis pyriputrescens

Sphaeropsis pyriputrescens, the causal agent of Sphaeropsis rot of pears and apples, is a recently described species. In this study the effects of culture media, temperature, water potential, pH and light on mycelial growth and pycnidial production of S. pyriputrescens were evaluated. Apple juice agar and pear juice agar were most suitable for mycelial growth of all six isolates tested. Cornmeal agar was not suitable for either mycelial growth or pycnidial production. The fungus grew from -3 to 25 C, with optimum growth at 20 C and no growth at 30 C. The fungus grew at water potential as low as -5.6 MPa on potassium chloride-amended potato-dextrose agar (PDA). Hyphal extension was not observed at -7.3 MPa after 10 d incubation, but growth resumed when the inoculum plugs were placed on PDA. The fungus grew at pH 3.3-6.3 and optimum growth was at pH 3.3-4.2. No mycelial growth was observed at pH above 7.2 after 10 d incubation, but growth resumed when the inoculum plugs were transferred onto PDA. Regardless of medium tested, few pycnidia formed at 20 C in the dark. Pycnidial production was enhanced significantly by fluorescent light, but continuous light appeared to reduce pycnidial production, depending on the medium. Oatmeal agar (OMA) was most suitable for production of pycnidia and conidia. Pycnidia that formed on 3 wk old OMA cultures at 20 C under 12 h light/12 h dark produced abundant conidia, and the technique is recommended for inoculum production.

Pharmacokinetics of total and unbound ertapenem in healthy elderly subjects

Ertapenem is a new once-a-day parenteral carbapenem antimicrobial agent. The pharmacokinetics of unbound and total concentrations of ertapenem in plasma were investigated in elderly subjects and compared with historical data from young adults. In a single- and multiple-dose study, healthy elderly males and females (n = 14) 65 years old or older were given a 1-g intravenous (i.v.) dose once daily for 7 days. Plasma and urine samples collected for 24 h on days 1 and 7 following administration of the 1-g doses were analyzed by reversed-phase high-performance liquid chromatography. Areas under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) for elderly females and males were similar following administration of 1-g single i.v. doses, and thus, the genders were pooled in subsequent analyses. Concentrations in plasma and the half-life of ertapenem were generally higher and longer, respectively, in elderly subjects than in young adults. The mean AUC(0- infinity ) of total ertapenem in the elderly was 39% higher than that in young subjects following administration of a 1-g dose. The differences were slightly greater for the mean AUC(0- infinity ) of unbound ertapenem (71%). The unbound fraction of ertapenem in elderly subjects ( approximately 5 to 11%) was generally greater than that in young adults ( approximately 5 to 8%). As in young adults, ertapenem did not accumulate upon multiple dosing in the elderly. The pharmacokinetics of ertapenem in elderly subjects, while slightly different from those in young adults, do not require a dosage adjustment for elderly patients.

First Report of a New Postharvest Fruit Rot on Apple Caused by Sphaeropsis pyriputrescens

During March to July 2003, a postharvest fruit rot was observed on 'Golden Delicious', 'Granny Smith', and 'Red Delicious' apples (Malus × domestica Borkh.) sampled from commercial packinghouses in Washington State. Losses as high as 24% in storage bins were observed in July on 'Red Delicious'. The disease started at the stem bowl area or the calyx end of the fruit. Decayed fruit was apparently not wounded. Decayed areas were brown and firm. Internal decayed flesh appeared yellowish brown. On 'Red Delicious' apples, decayed fruit was apparently discolored from red to brown. As the disease advanced, pycnidia of a fungus might form on the stem, sepals, or the surface of decayed fruit. Pycnidia were 0.3 to 0.7 mm in diameter, black, and partially immersed in decayed tissues. To isolate the causal agent, decayed fruit was lightly sprayed with 70% ethanol and air dried. Fragments of diseased tissue were removed from the margin of diseased and healthy tissue and plated on acidified potato dextrose agar (PDA). A fungus was consistently isolated from decayed fruit with the symptoms described above. On PDA, the colonies of the fungus first appeared with dense hyaline mycelium and later turned light yellow to yellow. Black pycnidia of the fungus formed on 2- to 3-week-old oatmeal agar cultures at 20°C under 12-h alternating cycles of fluorescent light and dark. The fungus was identified as Sphaeropsis pyriputrescens Xiao & J. D. Rogers, based on the description of the fungus (1). Voucher specimens were deposited at the WSU Mycological Herbarium. Two isolates of the fungus recovered from decayed apples were tested for pathogenicity on apple. Fruit of 'Golden Delicious' and 'Gala' were surface-disinfested for 5 min in 0.5% NaOCl, rinsed, and air dried. Fruit was wounded with a sterile 4-mm-diameter nail head. A 4-mm-diameter plug from the leading edge of a 3-day-old PDA culture or plain PDA (control) was placed in the wound of each of 10 replicate fruit for each isolate or control. Fruit was tray packed with polyethylene liners and stored in cardboard boxes in air at 3°C, and decay was evaluated 2 weeks after inoculation. Five decayed fruits from each treatment were selected for reisolation of the causal agent. The experiment was conducted twice. In a separate pathogenicity test, two isolates (one each from apple and pear) were included in the test. Fruit of 'Red Delicious' apple was prepared and inoculated as the same manner described above, but fruit was stored in air at 0°C. The experiment was conducted twice. All fruit that were inoculated with the fungus developed decay symptoms. No decay developed on fruit in the controls. The same fungus was reisolated from decayed fruit. This indicates that isolates from apple and pear were pathogenic to apple. S. pyriputrescens is the causal agent of a newly reported postharvest disease on 'd'Anjou' pears (1). To our knowledge, this is the first report of this fungus causing postharvest fruit rot on apple. We propose 'Sphaeropsis rot' as the name of this new disease on apple and pear. Preliminary evidence suggests that infection of fruit by this fungus occurred in the orchard prior to storage. Reference: (1) C. L. Xiao and J. D. Rogers. Plant Dis. 88:114, 2004.

A Postharvest Fruit Rot in d'Anjou Pears Caused by Sphaeropsis pyriputrescens sp. nov

During a survey of postharvest diseases in stored pears conducted in the 2001-02 storage season, a new postharvest fruit rot in d'Anjou pears was discovered in Washington State. Symptoms of this disease were stem-end rot, calyx-end rot, and wound-associated rot, which presumably originated from infections of stem, calyx, and wounds on the fruit surfaces, respectively. The decayed area on the fruit was firm or spongy and appeared brown. During the late storage period from March to May 2002, this disease was observed in 19 of 39 lots and accounted for 2 to 21% of all decayed fruit. The causal agent, Sphaeropsis sp., was consistently recovered from decayed fruit with the symptoms described above. Two isolates of the fungus were used for pathogenicity tests on pear fruit. Decay symptoms developed on fruit inoculated with spore suspensions of the fungus on the stem, calyx, and wounds on the fruit surface. The fungus was reisolated from these decayed fruit. The fungus, Sphaeropsis pyriputrescens sp. nov., was characterized and described. On potato dextrose agar (PDA), oatmeal agar, and pear juice agar at 20°C, the fungus grew at mean rates of 21, 15, and 24 mm day^-1 in colony diameter, respectively. On PDA, the fungus formed a circular colony with dense, hyaline hyphae and a few or some aerial mycelia. Colonies appeared light yellow to yellow on 2-week-old PDA cultures. The fungus grew at temperatures from 0 to 25°C, with optimum growth between 15 and 20°C, little or no growth at 30°C, and no growth at 35°C. This is a low-temperature species.

Amylase-binding proteins A (AbpA) and B (AbpB) differentially affect colonization of rats' teeth by Streptococcus gordonii

Streptococcus gordonii produces two alpha-amylase-binding proteins, AbpA and AbpB, that have been extensively studied in vitro. Little is known, however, about their significance in oral colonization and cariogenicity (virulence). To clarify these issues, weanling specific pathogen-free Osborne-Mendel rats, TAN : SPFOM(OM)BR, were inoculated either with wild-type strains FAS4-S or Challis-S or with strains having isogenic mutations of abpA, abpB, or both, to compare their colonization abilities and persistence on the teeth. Experiments were done with rats fed a sucrose-rich diet containing low amounts of starch or containing only starch. The mutants and wild-types were quantified in vivo and carious lesions were scored. In 11 experiments, S. gordonii was a prolific colonizer of the teeth when rats were fed the sucrose (with low starch)-supplemented diet, often dominating the flora. Sucrose-fed rats had several-fold higher recoveries of inoculants than those eating the sucrose-free, starch-supplemented diet, regardless of inoculant type. The strain defective in AbpB could not colonize teeth of starch-only-eating rats, but could colonize rats if sucrose was added to the diet. Strains defective in AbpA surprisingly colonized better than their wild-types. A double mutant deficient in both AbpA and AbpB (abpA/abpB) colonized like its wild-type. Wild-types FAS4-S and Challis-S had no more than marginal cariogenicity. Notably, in the absence of AbpA, cariogenicity was slightly augmented. Both the rescue of colonization by the AbpB- mutant and the augmentation of colonization by AbpA- mutant in the presence of dietary sucrose suggested additional amylase-binding protein interactions relevant to colonization. Glucosyltransferase activity was greater in mutants defective in abpA and modestly increased in the abpB mutant. It was concluded that AbpB is required for colonization of teeth of starch-eating rats and its deletion is partially masked if rats eat a sucrose-starch diet. AbpA appears to inhibit colonization of the plaque biofilm in vivo. This unexpected effect in vivo may be associated with interaction of AbpA with glucosyltransferase or with other colonization factors of these cells. These data illustrate that the complex nature of the oral environment may not be adequately modelled by in vitro systems.

Pharmacokinetics of ertapenem in healthy young volunteers

Ertapenem (INVANZ) is a new once-a-day parenteral beta-lactam antimicrobial shown to be effective as a single agent for treatment of various community-acquired and mixed infections. The single- and multiple-dose pharmacokinetics of ertapenem at doses up to 3 g were examined in healthy young men and women volunteers. Plasma and urine samples collected were analyzed using reversed-phase high-performance liquid chromatography with UV detection. Ertapenem is highly bound to plasma protein. The protein binding changes from approximately 95% bound at concentrations of <50 micro g/ml to approximately 92% bound at concentrations of 150 micro g/ml (concentration at the end of a 30-min infusion following the 1-g dose). The nonlinear protein binding of ertapenem resulted in a slightly less than dose proportional increase in the area under the curve from 0 h to infinity (AUC(0- infinity )) of total ertapenem. The single-dose AUC(0- infinity ) of unbound ertapenem was nearly dose proportional over the dose range of 0.5 to 2 g. The mean concentration of ertapenem in plasma ranged from approximately 145 to 175 micro g/ml at the end of a 30-min infusion, from approximately 30 to 34 micro g/ml at 6 h, and from approximately 9 to 11 micro g/ml at 12 h. The mean plasma t(1/2) ranged from 3.8 to 4.4 h. About 45% of the plasma clearance (CL(P)) was via renal clearance. The remainder of the CL(P) was primarily via the formation of the beta-lactam ring-opened metabolite that was excreted in urine. There were no clinically significant differences between the pharmacokinetics of ertapenem in men and women. Ertapenem does not accumulate after multiple once-daily dosing.

A rapid and sensitive liquid chromatography/negative ion tandem mass spectrometry method for the determination of an indolocarbazole in human plasma using 96-well diatomaceous earth plates for solid-liquid extraction [correction of using internal standard (IS) 96-well diatomaceous earth plates for solid-liquid extraction]

A sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the quantitation of a novel topoisomerase I inhibitor (indolocarbazole derivative I) in human plasma was developed to support clinical studies. Drug and internal standard were isolated from plasma by solid-liquid extraction using 96-well diatomaceous earth plates. Various extraction solvents were evaluated for extraction of I and 9% isopropyl alcohol (IPA) in methyl-tert-butyl ether (MtBE) was chosen as the optimal extraction solvent. The sensitivity of this LC/MS/MS method is 10x higher in negative ion mode using alkaline conditions than in positive ion mode using a wide range of pH's. A mobile phase with 2 mM ammonium hydroxide enhanced the sensitivity in negative ion mode over other volatile bases. The calibration curve for compound I is linear over the range 0.05-200 ng/mL in plasma and the lower limit of quantification (LLOQ) of the assay is 0.05 ng/mL, when 0.25 mL of plasma is processed. The method was fully validated and successfully applied to plasma samples from clinical studies. Performing chromatography at high pH, for enhanced negative ion sensitivity, eliminates the need for post-column addition of base. Furthermore, the 96-well diatomaceous earth plate extraction offers the following advantages over liquid-liquid extraction (LLE) or solid-phase extraction (SPE): clean sample extracts with reduced sample preparation time; increased sample throughput; no conditioning or washing steps; and a neutral eluate applicable to acid/base labile compounds.

Role of Streptococcus gordonii amylase-binding protein A in adhesion to hydroxyapatite, starch metabolism, and biofilm formation

Interactions between bacteria and salivary components are thought to be important in the establishment and ecology of the oral microflora. alpha-Amylase, the predominant salivary enzyme in humans, binds to Streptococcus gordonii, a primary colonizer of the tooth. Previous studies have implicated this interaction in adhesion of the bacteria to salivary pellicles, catabolism of dietary starches, and biofilm formation. Amylase binding is mediated at least in part by the amylase-binding protein A (AbpA). To study the function of this protein, an erythromycin resistance determinant [erm(AM)] was inserted within the abpA gene of S. gordonii strains Challis and FAS4 by allelic exchange, resulting in abpA mutant strains Challis-E1 and FAS4-E1. Comparison of the wild-type and mutant strains did not reveal any significant differences in colony morphology, biochemical metabolic profiles, growth in complex or defined media, surface hydrophobicity, or coaggregation properties. Scatchard analysis of adhesion isotherms demonstrated that the wild-type strains adhered better to human parotid-saliva- and amylase-coated hydroxyapatite than did the AbpA mutants. In contrast, the mutant strains bound to whole-saliva-coated hydroxyapatite to a greater extent than did the wild-type strains. While the wild-type strains preincubated with purified salivary amylase grew well in defined medium with potato starch as the sole carbohydrate source, the AbpA mutants did not grow under the same conditions even after preincubation with amylase. In addition, the wild-type strain produced large microcolonies in a flow cell biofilm model, while the abpA mutant strains grew much more poorly and produced relatively small microcolonies. Taken together, these results suggest that AbpA of S. gordonii functions as an adhesin to amylase-coated hydroxyapatite, in salivary-amylase-mediated catabolism of dietary starches and in human saliva-supported biofilm formation by S. gordonii.

Interactions between simvastatin and troglitazone or pioglitazone in healthy subjects

Two randomized, two-period crossover studies were conducted to evaluate the effects of repeat oral dosing of troglitazone (Study I) and pioglitazone (Study II) on the pharmacokinetics of plasma HMG-CoA reductase inhibitors following multiple oral doses of simvastatin and of simvastatin on the plasma pharmacokinetics of troglitazone (Study I) in healthy subjects. In both studies, each subject received two treatments. Treatment A consisted of once-daily oral doses of troglitazone 400 mg (Study I) or pioglitazone 45 mg (Study II) for 24 days with coadministration of once-daily doses of simvastatin 40 mg (Study I) or 80 mg (Study II) on Days 15 through 24. Treatment B consisted of once-daily oral doses of simvastatin 40 mg (Study I) or 80 mg (Study II) for 10 days. In Study I, the area under the plasma concentration-time profiles (AUC) and maximum plasma concentrations (Cmax) of HMG-CoA reductase inhibitors in subjects who received both troglitazone and simvastatin were decreased modestly (by approximately 30% for Cmax and approximately 40% for AUC), but time to reach Cmax (tmax) did not change, as compared with those who received simvastatin alone. Simvastatin, administered orally as a 40 mg tablet daily for 10 days, did not affect the AUC or tmax (p > 0.5) but caused a small but clinically insignificant increase (approximately 25%) in Cmax for troglitazone. In Study II, pioglitazone, at the highest approved dose for clinical use, did not significantly alter any of the pharmacokinetic parameters (AUC, Cmax, and tmax) of simvastatin HMG-CoA reductase inhibitory activity. For all treatment regimens, side effects were mild and transient, suggesting that coadministration of simvastatin with either troglitazone or pioglitazone was well tolerated. The modest effect of troglitazone on simvastatin pharmacokinetics is in agreement with the suggestion that troglitazone is an inducer of CYP3A. The insignificant effect of simvastatin on troglitazone pharmacokinetics is consistent with the conclusion that simvastatin is not a significant inhibitor for drug-metabolizing enzymes. The lack of pharmacokinetic effect of pioglitazone on simvastatin supports the expectation that this combination may be used safely.

Determination of a beta(3)-agonist in human plasma by LC/MS/MS with semi-automated 48-well diatomaceous earth plate

Methods for the determination of a beta(3)-agonist (A) in human plasma were developed and compared based on high-performance liquid chromatography (HPLC) with tandem mass spectrometric (MS/MS) detection using a turbo ion spray (TIS) interface. Drug and internal standard were isolated from plasma by three sample preparation methods, liquid-liquid extraction, Chem Elut cartridges and 48-well diatomaceous earth plates, that successively improved sample throughput for LC/MS/MS. MS/MS detection was performed on a PE Sciex API 365 tandem mass spectrometer operated in positive ion mode and using multiple reaction monitoring (MRM). The precursor/product ion combinations of m/z 625/607 and 653/515 were used to quantify A and internal standard, respectively, after chromatographic separation of the analytes. Using liquid-liquid extraction and Chem Elut cartridges, the assay concentration range was 0.5-100 ng/ml. Using diatomaceous earth plates, the concentration range of the assay was extended to 0.5-200 ng/ml. For all three assays, the statistics for precision and accuracy is comparable. The assay accuracy ranged from 91-107% and intraday precision as measured by the coefficient of variation (CV) ranged 2-10%. The sample throughput was tripled when the diatomaceous earth plate method was compared with the original liquid-liquid extraction method.

Pharmacokinetics of rizatriptan in healthy elderly subjects

OBJECTIVE

Rizatriptan is a serotonin 5-HT1B/1D receptor agonist for acute treatment of migraine. Its pharmacokinetics were assessed in healthy elderly males and females receiving a single 10 mg tablet oral dose. The pharmacokinetic data (AUC(0-infinity) and Cmax) for the elderly in this study were compared with historical data from previous studies for healthy young adults (n = 65).

METHODS

In a double-blind, parallel, placebo-controlled study, healthy elderly female and male subjects aged 65 or older (n = 8 each) received a single oral dose of 10 mg rizatriptan. Plasma and urine concentrations of drug were determined by HPLC with tandem mass spectrometry detection at several collection time points or intervals starting at predose and postdose over 24 h.

RESULTS

In elderly subjects, the geometric mean values for AUC(0-infinity) and Cmax were 77.7 ng/h/ml and 21.9 ng/ml; the average values for tmax, half-life (t 1/2), renal clearance (Clr), and percent urinary excretion of dose (Ue) were 1.2 h, 1.8 h, 197 ml/min and 9.3%, respectively. The AUC(0-infinity) and Cmax of rizatriptan were similar in elderly and young subjects. The geometric mean AUC ratio of elderly to young was 0.96 with 90% confidence interval (0.83, 1.11), p > 0.25. The geometric mean Cmax ratio was 0.89 with 90% confidence interval (0.72, 109), p > 0.25. No significant pharmacokinetic differences were observed between elderly males and females.

CONCLUSIONS

The plasma pharmacokinetics of rizatriptan appear to be similar in the elderly and young. In the elderly, the pharmacokinetics of rizatriptan do not appear to differ between male and female to a clinically significant extent.

RegG, a CcpA homolog, participates in regulation of amylase-binding protein A gene (abpA) expression in Streptococcus gordonii

The amylase-binding protein A (AbpA) of Streptococcus gordonii was found to be undetectable in supernatants of mid-log-phase cultures containing >1% glucose but abundant in supernatants of cultures made with brain heart infusion (BHI), which contains 0.2% glucose. A 10-fold decrease in the level of abpA mRNA in S. gordonii cells cultured in BHI was noted after the addition of glucose to 1%. Analysis of the abpA sequence revealed a potential catabolite responsive element CRE 153 bp downstream of the putative translational start site. A catabolite control protein A gene (ccpA) homolog from S. gordonii, designated regG, was cloned. A regG mutant strain demonstrated moderately less repression of abpA transcription in the presence of 1% glucose. Diauxic growth with glucose and lactose was not affected in the RegG mutant compared to the wild-type parental strain. These results suggest that while RegG plays a role in abpA expression, other mechanisms of catabolite repression are present.

Montelukast dose selection in children ages 2 to 5 years: comparison of population pharmacokinetics between children and adults

Montelukast, a leukotriene receptor antagonist, has demonstrated efficacy and tolerability in the treatment of asthma in patients age 6 years and older. The purpose of this open, one-period, multicenter population pharmacokinetic study was to identify a chewable tablet (CT) dose of montelukast for administration to children ages 2 to 5 years with asthma, yielding a single-dose pharmacokinetic profile (area under the plasma concentration-time curve [AUC]) comparable to that of the 10 mg film-coated tablet (FCT) dose in adults. Because patient numbers were small and the volume of blood that could be collected from individual 2- to 5-year-old patients was limited, a population pharmacokinetic approach was used to estimate population AUC (AUCpop). The 4 mg CT dose of montelukast was well tolerated and yielded an AUCpop (2721 ng.h/mL) similar to that of the adult AUCpop (2595 ng.h/mL) observed after a 10 mg FCT dose. These results support the selection of a 4 mg once-daily CT dose of montelukast for future efficacy and safety studies in children ages 2 to 5 years with asthma.

Oral colonization and cariogenicity of Streptococcus gordonii in specific pathogen-free TAN:SPFOM(OM)BR rats consuming starch or sucrose diets

The significance of Streptococcus gordonii in dental caries is undefined, as is that of other alpha-amylase-binding bacteria (ABB) commonly found in the mouth. To clarify the ecological and cariological roles of S. gordonii our specific pathogen-free Osborne-Mendel rats, TAN:SPFOM(OM)BR, were fed either diet 2000 (containing 56% confectioner's sugar, most of which is sucrose) or diet 2000CS (containing 56% cornstarch, in lieu of confectioner's sugar) and inoculated with S. gordonii strains. Uninoculated rats were free of both indigenous mutans streptococci (MS) and ABB, including S. gordonii, as shown by culture on mitis salivarius and blood agars of swabs and sonicates of dentitions after weanlings had consumed these diets for 26 days. ABB were detected by radiochemical assay using [125I]-amylase reactive to alpha-amylase-binding protein characteristic of the surface of S. gordonii and other ABB. No ABB were detected (detection limit < 1 colony-forming units in 10(6) colony-forming units). Thus the TAN:SPFOM(OM)BR colony presents a 'clean animal model' for subsequent study. Consequently, S. gordonii strains Challis or G9B were used to inoculate weanling rat groups consuming either the high-sucrose diet 2000 or the cornstarch diet 2000CS. Two additional groups fed each of these diets remained unioculated. Recoveries of inoculants were tested 12 and 26 days later by oral swabs and sonication of the molars of one hemimandible of each animal, respectively. Uninoculated animals were reconfirmed to be free of ABB and mutans streptococci, but inoculated ones eating diet 2000CS had S. gordonii recoveries of 1-10% or, if eating diet 2000, 10-30% of total colony-farming units in sonicates. There were no statistically significant differences among the inoculated and uninoculated animal groups' caries scores when they ate the cornstarch diet. Lesion scores for sucrose-eating rats were, however, from 2.4-5.1-fold higher than for cornstarch-eating rats, P < 0.001, and were still higher if animals had been inoculated with either Challis (1.41-fold) or G9B (1.64-fold), than if uninoculated, both P < 0.001, so long as the rats ate the sucrose diet. Therefore, TAN:SPFOM(OM)BR rats do not harbour ABB or S. gordonii but can be colonized by S. gordonii. Colonization levels of S. gordonii on the teeth are higher in the presence of high sucrose than with high starch-containing diets. Caries scores are augmented by sucrose compared with starch, and are further augmented by S gordonii colonization. S. gordonii is thus cariologically significant in the presence of sucrose, at least in this rat.

Ascobotryozyma americana gen. nov. et sp. nov. and its anamorph Botryozyma americana, an unusual yeast from the surface of nematodes

A new teleomorphic genus Ascohotryozyma, with a single species, A. americana, is proposed. Its anamorph is a Botryozyma that differs from the type species, B. nematodophila, on distributional, physiological, and molecular criteria; it is described as Botryozyma americana, anam. sp. nov. Ascobotryozyma is characterized by globose asci bearing four lunate ascospores. Fusion of thallus cells precedes ascus formation. Ascobotryozyma americana was isolated from the surface of nematodes (Panagrellus dubius) associated with galleries of the poplar borer (Saperda calcarata) in trembling aspen (Populus tremuloides) in eastern Washington, USA. The teleomorph has not been produced in pure culture.

Average volume of alcohol consumption, patterns of drinking, and all-cause mortality: results from the US National Alcohol Survey

The objective of this study was to investigate the effects of an average volume of alcohol consumption and drinking patterns on all-cause mortality. The sample (n = 5,072) was drawn from the 1984 National Alcohol Survey, representative of the US population living in households. Follow-up time was until the end of 1995, with 532 people deceased during this period. The authors found a significant influence of drinking alcohol on mortality with a J-shaped association for males and an insignificant relation of the same shape for females. When the largest categories of equivalent average volume of consumption were divided into people with and without heavy drinking occasions, serving as an indicator of drinking pattern, this differentiation proved important in predicting mortality. Light to moderate drinkers had higher mortality risks when they reported heavy drinking occasions (defined by either eight drinks per occasion or getting drunk at least monthly). Similarly, when the category of exdrinkers was divided into people who did or did not report heavy drinking occasions in the past, people with heavy drinking occasions had a higher mortality risk. Finally, indicating alcohol problems in the past was related to higher mortality risk. Results emphasized the importance of routinely including measures of drinking patterns into future epidemiologic studies on alcohol-related mortality.

Reports of alcohol-related harm: telephone versus face-to-face interviews

OBJECTIVE

To assess the effect of mode of administration in alcohol surveys (telephone vs face-to-face interviews), prevalence rates of self-reported harms due to alcohol were compared for two datasets with equivalent measures.

METHOD

Two national alcohol surveys were used: the 1990 Warning Labels Survey, in which random digit dialing was used to generate a sample of 2,000 adults interviewed by telephone, and the 1990 National Alcohol Survey (face-to-face interviews), a probability sample of U.S. adults living in households (N = 2,058). Both surveys included identical items on five areas of alcohol-related harm, yielding one composite index of any harm reported in the last 12 months that was compared between the two surveys for current drinkers.

RESULTS

After controlling for demographic characteristics and alcohol use, the telephone survey yielded significantly higher rates of alcohol-related health harm, work harm and "any harm" as compared to the in-person survey. The interaction between heavier drinking (five or more drinks during 1 day, weekly or more often) and method of data collection was significant for health harm and any harm. Respondents in the telephone survey who drank 5+ less than weekly were more likely than those interviewed in person to report health harm due to alcohol use; those in the telephone survey who drank 5+ weekly or more often were more likely to report any harm.

CONCLUSIONS

Possible explanations for differences between the surveys include anonymity and fewer social desirability issues associated with telephone surveys, as well as potentially differing cognitive requirements in telephone versus face-to-face interviews.

S-Adenosyl-Methionine improves depression in patients with Parkinson's disease in an open-label clinical trial

We report a pilot study of S-adenosyl-methionine (SAM) in 13 depressed patients with Parkinson's disease. All patients had been previously treated with other antidepressant agents and had no significant benefit or had intolerable side effects. SAM was administered in doses of 800 to 3600 mg per day for a period of 10 weeks. Eleven patients completed the study, and 10 had at least a 50% improvement on the 17-point Hamilton Depression Scale (HDS). One patient did not improve. Two patients prematurely terminated participation in the study because of increased anxiety. One patient experienced mild nausea, and another two patients developed mild diarrhea, which resolved spontaneously. The mean HDS score before treatment was 27.09 +/- 6.04 (mean +/- standard deviation) and was 9.55 +/- 7.29 after SAM treatment (p < 0.0001). Although uncontrolled and preliminary, this study suggests that SAM is well tolerated and may be a safe and effective alternative to the antidepressant agents currently used in patients with Parkinson's disease.

Simvastatin does not affect CYP3A activity, quantified by the erythromycin breath test and oral midazolam pharmacokinetics, in healthy male subjects

Potential for inhibition of CYP3A activity by simvastatin, an HMG-CoA reductase inhibitor, was evaluated in 12 healthy male subjects who received placebo or 80 mg of simvastatin, the maximal recommended dose, once daily for 7 consecutive days. On day 7, an intravenous injection of 3 microCi [14C N-methyl]erythromycin for the erythromycin breath test (EBT) was coadministered with a 2 mg oral solution of midazolam. The values for percent 14C exhaled during the first hour (for EBT) and the pharmacokinetic parameters of midazolam (AUC, Cmax, t1/2) were not affected following multiple once-daily oral doses of simvastatin 80 mg. The 95% confidence interval was 0.97 to 1.18 for EBT and 0.99 to 1.23 for midazolam AUC. In addition, the total urinary recoveries of midazolam and its 1'-hydroxy metabolites (free plus conjugate) obtained from both treatments were not statistically different (p > 0.200). These data demonstrate that multiple dosing of simvastatin, at the highest recommended clinical dose, does not significantly alter the in vivo hepatic or intestinal CYP3A4/5 activity as measured by the commonly used EBT and oral midazolam probes.

Breast and cervical carcinoma mortality among women in the Appalachian region of the U.S., 1976-1996

BACKGROUND

Previous studies have shown high cervical carcinoma mortality and increasing breast carcinoma mortality in the Appalachian region of the U.S. (which includes parts of 12 states and all of West Virginia). In the current study the authors report trends in breast and cervical carcinoma death rates among women in Appalachia for 1976-1996.

METHODS

Death rates were calculated from information provided on death certificates and reported to the National Center for Health Statistics for Appalachian women and for women living elsewhere in the U.S. ("other U.S. women"). Trends were examined with joinpoint regression techniques overall and by age and race. Average annual mortality rates were calculated by state for 1992-1996 for each state's Appalachian and non-Appalachian areas.

RESULTS

Overall breast carcinoma mortality was lower among Appalachian women than among other U.S. women throughout the study period; however, after rates decreased among both groups in the 1990s, the difference appears to have narrowed. No such decline was observed for women age >/= 70 years. Overall cervical carcinoma mortality was higher among Appalachian women than among other U.S. women but decreased during the study period to rates closer to those for other U.S. women. No significant decrease was observed among women age < 50 years. Overall, for both black and white women, breast carcinoma mortality was lower and cervical carcinoma mortality higher among women in Appalachia compared with their counterparts elsewhere in the U.S. For both breast and cervical carcinoma, the average annual death rates (1992-1996) varied by geographic areas within the Appalachian states, but most differences were not significant.

CONCLUSIONS

Analysis of mortality trends in breast and cervical carcinoma may provide guidance for prevention and control activities to reduce premature mortality from these diseases.

Montelukast adult (10-mg film-coated tablet) and pediatric (5-mg chewable tablet) dose selections

Montelukast is a selective leukotriene receptor antagonist that has been shown to be effective in the treatment of chronic asthma. It is approved in more than 70 countries for patients 6 years of age and older. For adults (> or = 15 years of age), a 10-mg film-coated tablet (FCT) is available, and for children (aged 6 to 14 years), a 5-mg chewable tablet (CT) is available. The adult montelukast dose (10-mg FCT) was selected on the basis of classic dose-ranging studies as the lowest dose that produces maximal improvement in both measures of airway function and patient-reported outcomes in chronic asthma and in the attenuation of exercise-induced bronchoconstriction. The strategy used for the pediatric dose selection for montelukast was based on the determination of a CT dose that would provide an overall systemic exposure to montelukast in children similar to that in adults who receive a 10-mg FCT dose. Because montelukast was to be given chronically for the treatment of asthma, the area under the plasma concentration-time curve was considered to be the pharmacokinetic measurement that best represented systemic exposure to the drug. A 5-mg CT yielded a comparable single-dose area under the plasma concentration-time curve profile to that of the adult 10-mg FCT dose and, therefore, was selected as the pediatric dose for children aged 6 to 14 years with asthma. Subsequently, 2 studies of efficacy and tolerability validated the choice of the 5-mg CT dose.

Quantitation of simvastatin and its beta-hydroxy acid in human plasma by liquid-liquid cartridge extraction and liquid chromatography/tandem mass spectrometry

A sensitive and reliable procedure for the simultaneous determination of simvastatin (SV) and its active beta-hydroxy acid metabolite (SVA) in human plasma was developed and validated. The analytes were extracted simultaneously from 0.5 ml aliquots of human plasma samples by methyl tert-butyl ether (MTBE) via Chem Elut cartridge extraction [also called liquid-solid extraction (LSE) or liquid-liquid cartridge extraction (LLCE)], separated through a Kromasil C(18) column (50 x 2 mm i.d. 5 microm) and detected by tandem mass spectrometry with a turbo ionspray interface. Stable isotope-labeled SV and SVA, (13)CD(3)-SV and (13)CD(3)-SVA, were used as internal standards. SV and SVA were detected in positive and negative ion modes, respectively, via within-run polarity switching. The use of Chem Elut cartridges not only provided a simple and efficient means of plasma sample extraction but also successfully reduced the interconversion between SV and SVA to an undetectable (for lactonization of SVA) or negligible (<0.07%, for hydrolysis of SV) level. The method showed excellent reproducibility, with intra- and inter-assay precisions <4.5% (RSD), and intra- and inter-assay accuracy between 94% and 107% of nominal values, for both analytes. The extraction recoveries were 78% and 87% on average for SV and SVA, respectively. The analyte was found to be stable in plasma through three freeze (-70 degrees C)-thaw (4 degrees C) cycles and for at least 3 h under bench-top storage condition in an ice-bath (4 degrees C), and also in the reconstitution solution at 4 degrees C for at least 24 h. The method has a lower limit of quantitation (LOQ) of 50 pg ml(-1) with a linear calibration range of 0.05-50 ng ml(-1) for both analytes, and has proved to be very reliable for the analysis of clinical samples.

Electroconvulsive therapy for elderly patients with multiple system atrophy: a case series

Multiple system atrophy (MSA) is a progressive neurological illness associated with parkinsonism. Electroconvulsive therapy (ECT) improves motor function in Parkinson's disease and, thus, might be beneficial in MSA. Three cases of MSA treated with ECT are described. All patients improved neurologically, but none regained independent ambulation. A review, including previously reported cases, demonstrates that ECT can be safe and effective for depression associated with MSA. Reduced tremor and rigidity may occur, but substantial gait improvement cannot be expected.

Effects of telephone versus face-to-face interview modes on reports of alcohol consumption

AIMS AND DESIGN

In order to assess the effects of survey modality on alcohol consumption estimates, data from two surveys using different interview modes (face-to-face and telephone) were compared on several alcohol measures.

SETTING AND PARTICIPANTS

Face-to-face survey data were drawn from the 1990 National Alcohol Survey, while the telephone data came from the 1990 Warning Labels Survey. Both surveys used a probability sampling of the US adult general population in the 48 contiguous states.

MEASUREMENTS

Measures of alcohol use derived from an identical "graduated frequencies" series included estimates of any drinking in the past 12 months, overall volume, and heavy (5+) drinking days.

FINDINGS

Abstention rates did not differ by survey mode, nor did distributions of alcohol consumption by volume and reported frequency of drinking five or more drinks in a day. Multiple regression models including demographic-mode interaction terms were used to examine how mode effects might differ across demographic subgroups. Lower income respondents were under-represented in the telephone sample, and were associated with lower reports of volume and 5+ days, compared to respondents in the face-to-face mode.

CONCLUSIONS

The results suggest that although there are few differences in alcohol consumption estimates by interview mode, telephone samples may need to be supplemented or estimates adjusted by income level in order to attain equivalent results.

Disposition and pharmacokinetics of the antimigraine drug, rizatriptan, in humans

The absorption and disposition of rizatriptan (MK-0462, Maxalt(TM)), a selective 5-HT(1B/1D) receptor agonist used in the treatment of migraine headaches, was investigated in humans. In a two-period, single i.v. (3 mg, 30-min infusion), and single oral (10 mg) dose study with [(14)C]rizatriptan in six healthy human males, total recovery of radioactivity was approximately 94%, with unchanged rizatriptan and its metabolites being excreted mainly in the urine (89% i.v. dose, 82% p.o. dose). Approximately 26 and 14% of i.v. and oral rizatriptan doses, respectively, were excreted in urine as intact parent drug. In a second, high-dose study (60 mg p.o.), five metabolites excreted into urine were identified using liquid chromatography-tandem mass spectrometry and NMR methods. They were triazolomethyl-indole-3-acetic acid, rizatriptan-N(10)-oxide, 6-hydroxy-rizatriptan, 6-hydroxy-rizatriptan sulfate, and N(10)-monodesmethyl-rizatriptan. Urinary excretion of triazolomethyl-indole-3-acetic acid after i.v. and oral administrations of rizatriptan accounted for 35 and 51% of the dose, respectively, whereas the corresponding values for rizatriptan-N(10)-oxide were 4 and 2% of the dose. Plasma clearance (CL) and renal clearance (CL(r)) were 1325 and 349 ml/min, respectively, after i.v. administration. A similar CL(r) value was obtained after oral administration (396 ml/min). The primary route of rizatriptan elimination occurred via nonrenal route(s) (i.e., metabolism) because the CL(r) of rizatriptan accounted for 25% of total CL. Furthermore, the CL(r) was higher than normal glomerular filtration rate ( approximately 130 ml/min), indicating that this compound was actively secreted by renal tubules. The absorption of rizatriptan was approximately 90%, but it experienced a moderate first-pass effect, resulting in a bioavailability estimate of 47%.

A 10-year national trend study of alcohol consumption, 1984-1995: is the period of declining drinking over?

OBJECTIVES

Data from the 1984, 1990, and 1995 National Alcohol Surveys were used to investigate whether declines shown previously in drinking and heavy drinking across many demographic subgroups have continued.

METHODS

Three alcohol consumption indicators--current drinking (vs abstaining), weekly drinking, and weekly heavy drinking (5 or more drinks in a day)--were assessed for the total US population and for demographic subgroups.

RESULTS

Rates of current drinking, weekly drinking, and frequent heavy drinking, previously reported to have decreased between the 1984 and 1990 surveys, remained unchanged between 1990 and 1995. Separate analyses for each beverage type (beer, wine, and spirits) and most demographic subgroups revealed similar temporal patterns.

CONCLUSIONS

Alcohol consumption levels, declining since the early 1980s, may reach a minimum by the 21st century. Consumption levels should be monitored carefully over the next few years in the event that long-term alcohol consumption trends may be shifting.

Prevalence of the amylase-binding protein A gene (abpA) in oral streptococci

Salivary amylase binds specifically to a number of oral streptococcal species. This interaction may play an important role in dental plaque formation. Recently, a 585-bp gene was cloned and sequenced from Streptococcus gordonii Challis encoding a 20.5-kDa amylase-binding protein (AbpA). The goal of this study was to determine if related genes are present in other species of oral streptococci. Biotinylated abpA was used in Southern blot analysis to screen genomic DNA from several strains representing eight species of oral streptococci. This probe hybridized with a 4.0-kb HindIII restriction fragment from all 13 strains of S. gordonii tested. The probe did not appear to bind to any restriction fragments from other species of amylase-binding oral streptococci including Streptococcus mitis (with the exception of 1 of 14 strains), Streptococcus crista (3 strains), Streptococcus anginosus (1 strain), and Streptococcus parasanguinis (1 strain), or to non-amylase-binding oral streptococci including Streptococcus sanguinis (3 strains), Streptococcus oralis (4 strains), and Streptococcus mutans (1 strain). Primers homologous to sequences within the 3' and 5' ends of abpA yielded products of 400 bp following PCR of genomic DNA from the Southern blot-positive strains. Several of these PCR products were cloned and sequenced. The levels of similarity of these cloned products to the abpA of S. gordonii Challis ranged from 91 to 96%. These studies reveal that the abpA gene appears to be specific to S. gordonii and differs from genes encoding amylase-binding proteins from other species of amylase-binding streptococci.

Beer drinking accounts for most of the hazardous alcohol consumption reported in the United States

OBJECTIVE

Patterns and correlates of hazardous drinking, defined as occasions in which five or more drinks were consumed in a day, were compared for wine, beer and distilled spirits.

METHOD

From a probability sample of the U.S. adult household population, 2,817 respondents who had consumed at least one drink in the previous year were selected for analysis.

RESULTS

The results show that, in the U.S., beer accounts for the bulk of alcohol consumed by the heaviest drinkers. Beer also accounts for a disproportionate share of hazardous drinking. Logistic regression analyses revealed that drinkers who consume beer in a hazardous fashion at least monthly are more likely to be young, male and unmarried, and less likely to be black than are other drinkers. Hazardous beer consumption is more predictive of alcohol-related problems than hazardous consumption of wine or spirits.

CONCLUSIONS

Three potential explanations for the results are considered: advertising, beer-drinking subcultures and risk compensation. Additional research is urged in order to better specify the causal role of these and other factors in hazardous beer drinking.

Alcoholic beverage choice, risk perception and self-reported drunk driving: effects of measurement on risk analysis

AIMS

The present study examined effects of measurement on risk curve analysis in an application involving prediction of frequency and indicator measures of drunk driving with beverage-specific alcohol consumption and risk perception measures.

DESIGN AND PARTICIPANTS

From a 1995 in-person survey of the US adult household population (response rate = 77%) the responses of 1260 adult drivers who reported any drinking in the prior year were selected for analysis. Regression and graphical techniques were used to investigate relationships between drinking pattern, beverage choice, perception of risks of drinking before driving, and frequency of drunk driving.

MEASUREMENTS

Self-reported drunk driving (occurrence) was measured by a question assessing driving after drinking enough to be in trouble if stopped by the police within the prior 12 months; those affirming this (n = 191) were asked how many times they did so (frequency). Alcohol consumption was assessed by beverage and in combination. Risk perception was assessed as a factor score from three correlated measures. Demographic variables included age, ethnicity, education and income.

FINDINGS

Controlling for demographics, heavy beer consumption (p < 0.01) more than heavy wine (NS) or liquor/spirits (p < 0.05) intake was strongly predictive of risk perception. A regression analysis showed a significant interaction between heavy beer consumption and perceived risk (p < 0.001) in predicting reported frequency of drunk driving, after controlling for heavy beer consumption (p < 0.05), total alcohol consumption and risk perception (both ps < 0.001). No interactions were important in equivalent models predicting dichotomous occurrence. Graphic analysis showed the shape of the risk curve is altered when frequency of drunk driving is taken into account rather than simple occurrence.

CONCLUSIONS

Individuals' underestimation of beer's intoxicating effects, compared to other alcoholic beverage types, helps explain beer's over-representation in drinking driving violation reports. There is a need for creative public health campaigns designed to inform young men of beer's alcohol content and associated risks.

Grapefruit juice has minimal effects on plasma concentrations of lovastatin-derived 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors

OBJECTIVE

To evaluate the effect of regular-strength grapefruit juice, a cytochrome P4503A4 (CYP3A4) inhibitor, on the pharmacokinetics of a commonly prescribed regimen of oral lovastatin.

METHODS

In a randomized crossover study, 16 healthy subjects received a single 40 mg dose of lovastatin in the evening after each consumed an 8-ounce glass of regular-strength grapefruit juice or water with breakfast for 3 consecutive days. The effect of the same grapefruit juice and water regimen on the pharmacokinetics of midazolam (2 mg oral dose given 1 hour after the third day of grapefruit juice and water) was used as a positive control in the same subjects. Plasma concentrations of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors were determined by an enzyme inhibition assay, and concentrations of lovastatin, lovastatin acid, and midazolam were determined by liquid chromatography-tandem mass spectrometry.

RESULTS

The area under the plasma concentration-time profiles (AUC) and maximum plasma concentrations (Cmax) of HMG-CoA reductase inhibitors increased slightly (-30% for each) after consumption of grapefruit juice. Similar effects on AUC and Cmax (approximately 40% increase for each) were noted after analysis of samples of hydrolyzed plasma (which converts inactive lactones to active hydroxy acid species). The AUC and Cmax values for lovastatin approximately doubled in the presence of grapefruit juice, whereas the same parameters for lovastatin acid increased 1.6-fold. Grapefruit juice caused the AUC for midazolam to increase by a factor of approximately 2.4.

CONCLUSIONS

Daily consumption of a glass of regular-strength grapefruit juice has a minimal effect on plasma concentrations of HMG-CoA reductase inhibitors (approximately 30% to 40% increase) after a 40 mg evening dose of lovastatin.

Determination of L-753,037 in human plasma by liquid chromatography/turbo ionspray tandem mass spectrometry

A liquid chromatographic/turbo ionspray tandem mass spectrometric (LC/MS/MS) method was developed and validated for the determination of L-753,037, a potent endothelin receptor antagonist currently under development for the treatment of cardiovascular diseases, in human plasma. L-753,037 is extracted from 0.5 ml of human plasma using liquid-liquid extraction and analyzed by LC/MS/MS with a turbo ionspray interface. Method validation results showed that this method is very sensitive, reliable, selective and reproducible. L-753,048, an ethoxy analogue of L-753,037, was used as the internal standard. The method has a lower limit of quantitation (LOQ) of 50 pg ml(-1) with a linear calibration range of 0.05-50 ng ml(-1). The intra-day precision and accuracy (n = 5) were measured to be below 10% relative standard deviation (RSD) and between 97.4 and 102.8% of the nominal values, respectively, for all calibration standard concentrations within the calibration curve range. The inter-day precision and accuracy (n = 3 days, 5 replicates per day) were measured to be below 6.5% RSD and between 99.3 and 102.0% of the nominal values, respectively, for all quality control concentrations. The extraction recovery was determined to be approximately 99% on average. The analyte was found to be stable in plasma through three freeze-thaw cycles, for at least 4 h at ambient temperature and for up to 40 days under -20 degrees C freezer storage conditions. The analyte was also shown to be stable for at least 24 h in the reconstitution solution at room temperature and for up to 3 days as a dried extract at 4 degrees C. Additional variations in plasma concentration of the analyte due to the use of different sources of plasma were also evaluated.

Montelukast dose selection in 6- to 14-year-olds: comparison of single-dose pharmacokinetics in children and adults

Montelukast, an oral leukotriene-receptor antagonist, has demonstrated efficacy and tolerability for the treatment of chronic asthma in adults. A once-daily 10 mg dose (film-coated tablet) was selected as the optimal adult dose based on dose-ranging studies. Asthma is a similar disease and is treated with the same medications in children and adults. These observations suggested that a dose of montelukast in children providing overall drug exposure (i.e., montelukast plasma concentrations) similar to that of the 10 mg film-coated tablet dose in adults would be efficacious, well tolerated, and obviate the need for separate dose-ranging studies in children. Therefore, the dose of montelukast for 6- to 14-year-old children was selected by identifying the chewable tablet dose of montelukast yielding a single-dose area under the plasma concentration-time curve (AUC) comparable to that achieved with the adult 10 mg film-coated tablet dose. Based on this approach, which included dose normalization of data from several pediatric pharmacokinetic studies, a 5 mg chewable tablet dose of montelukast was selected for use in clinical efficacy studies in 6- to 14-year-old children with asthma.

Falling asleep at the wheel: motor vehicle mishaps in persons taking pramipexole and ropinirole

The authors report a new side effect of the dopamine agonists pramipexole and ropinirole: sudden irresistible attacks of sleep. Eight PD patients taking pramipexole and one taking ropinirole fell asleep while driving, causing accidents. Five experienced no warning before falling asleep. The attacks ceased when the drugs were stopped. Neurologists who prescribe these drugs and patients who take them should be aware of this possible side effect.

Sun protection behaviors among African Americans

The anatomic distribution of some skin cancers suggests that sun exposure may be an etiologic factor for skin cancer among African Americans. Yet little is known about sun protection behaviors among African Americans. We analyzed data from the 1992 National Health Interview Survey (N = 1,583) to determine the prevalence of sun protection behaviors and sun sensitivity. About 6% of African Americans reported being extremely sensitive to the sun and severe sunburning, and 9% reported mild burns. Overall, 53% of respondents (47% of men and 57% of women) reported that they were very likely to wear protective clothing, seek shade, or use sunscreen lotion. Women were more likely than men to report seeking shade and using sunscreen. Sun protection behaviors were more frequently reported by those who sunburn more easily and were positively associated with age. Use of sunscreen was positively associated with income and education. Education about sun protection and early detection may help reduce the morbidity and mortality of skin cancer among African Americans.

Pharmacokinetics and tolerability of oral rizatriptan in healthy male and female volunteers

AIMS

The pharmacokinetics and dose proportionality of rizatriptan single oral doses from 2.5 to 15 mg administered as solutions to healthy volunteers were studied.

METHODS

In a randomized, crossover study with four periods, twenty-four healthy volunteers (12 males and 12 females) took single oral doses of 2.5, 5, 10, and 15 mg rizatriptan in Periods 1-4. In a fifth period, subjects received 4 mg intravenous (i.v.) rizatriptan as a reference. Plasma and urine rizatriptan concentrations were determined at several timepoints/intervals for 12 and 24 h, respectively.

RESULTS

The arithmetic mean AUC values following single oral doses of 2.5, 5, 10, and 15-mg rizatriptan were 16, 33, 72, and 127 ng ml-1 h, respectively, in males; and 19, 42, 97, and 161 ng ml-1 h, respectively, in females. The overall bioavailability (F ) of rizatriptan was approximately 40% in males. Following the 4 mg reference i.v. dose, the apparent plasma clearance (CL) and renal clearance (CLr ) were 1042 and 225 ml min-1, respectively, in males; and 821 and 174 ml min-1, respectively, in females.

CONCLUSIONS

The disposition kinetics of oral rizatriptan were linear for doses of 2. 5-10 mg in males, and for doses of 2.5-5 mg in females. However, the degree of nonlinearity for higher doses was minor for both genders. The plasma concentrations of rizatriptan were slightly greater in women compared to men but the difference was not considered to be clinically meaningful. Also, the clearance of rizatriptan appeared to be mainly nonrenal.

Update on the incidence and mortality from melanoma in the United States

BACKGROUND

Increases in the incidence of malignant melanoma have been among the largest of all cancers in the United States.

OBJECTIVE

We report updated trends in melanoma rates among the US white population.

METHODS

Incidence and mortality rates were calculated for 1973 to 1994. Trends were examined with stratification by state, age, and sex, and by anatomic site, stage, and melanoma thickness at diagnosis.

RESULTS

Melanoma incidence and mortality rates increased dramatically from 1973 to 1994, rising 120.5% and 38.9%, respectively. In recent years, however, rates for most age-sex groups appeared to stabilize or even decline. Male patients continued to have higher incidence and mortality rates than female patients, but for both male and female patients the largest increases by site were for the trunk. A large proportion of melanomas were detected in the local stage and with a thickness less than 0.75 mm.

CONCLUSION

Prevention of sun exposure is recommended to reverse the high incidence rates of melanoma.

Who drinks most of the alcohol in the US? The policy implications

OBJECTIVE

The concentration of alcohol consumption in the U.S. among the heaviest drinkers is analyzed with data from two recent probability samples of the adult population.

METHOD

Pooled data from four national telephone surveys (N = 7,049; 4,784 drinkers) with uniform methodology are used for the primary analysis, and data from an in-person national household survey (N = 2,058; 1,308 drinkers) are used for confirmatory analysis. Each survey systematically measured self-reported alcohol consumption during the prior year using a "graduated frequencies" approach designed to capture drinking at a series of amount-per-day levels.

RESULTS

The two studies produced very similar estimates: the top 2.5% of drinkers by volume account for 27% and 25% of the nation's total self-reported alcohol consumption in the telephone and in-person surveys, respectively; the top 5% account for 42% and 39%; and the top 20% of drinkers account for 89% and 87% in each survey, respectively. Men were overrepresented at the highest volumes, contributing about 76% of the country's total reported consumption. Similarly, young adults aged 18 to 29 are disproportionately represented in the heaviest drinking levels; constituting 27% of the population, they account for about 45% of overall adult drinking.

CONCLUSIONS

The bulk of the alcohol reported drunk in the U.S. is consumed by a relatively small population of very heavy drinkers. Prevention policies implied by this concentration include strengthening of social norms discouraging heavy consumption, restricting marketing practices that target heavy drinkers, and implementing measures to reduce consumption by the heaviest drinkers.

High-performance liquid chromatographic methods for the determination of a new carbapenem antibiotic, L-749,345, in human plasma and urine

A column-switching, reversed-phase high-performance liquid chromatographic (HPLC) method for the determination of a new carbapenem antibiotic assay using ultraviolet detection has been developed for a new carbapenem antibiotic L-749,345 in human plasma and urine. A plasma sample is centrifuged and then injected onto an extraction column using 25 mM phosphate buffer, pH 6.5. After 3 min, using a column-switching valve, the analyte is back-flushed with 10.5% methanol-phosphate buffer for 3 min onto a Hypersil 5 microm C18 BDS 100x4.6 mm analytical column and then detected by absorbance at 300 nm. The sample preparation and HPLC conditions for the urine assay are similar, except for a longer analytical column 150x4.6 mm. The plasma assay is specific and linear from 0.125 to 50 microg/ml; the urine assay is linear from 1.25 to 100 microg/ml.

Pharmacokinetics and tolerability of intravenous rizatriptan in healthy females

The pharmacokinetics and tolerability of intravenous (i.v.) rizatriptan (MK-0462), a novel 5-HT1D/1B receptor agonist for the acute oral treatment of migraine, were examined in an open, single-dose, four-period, randomized crossover study in healthy females. Results of this study indicated that i.v. rizatriptan (0.5-5 mg) was well tolerated. The disposition kinetics of rizatriptan were linear for i.v. doses up to and including 2.5 mg. Relative to the 0.5 mg dose, geometric mean dose-adjusted AUC ratios were 1.04, 1.09, and 1.18 for 1, 2.5, and 5 mg doses, respectively. Apparent plasma clearance (Cl) ranged between 859 and 941 mL min(-1) from 0.5 to 2.5 mg, but dropped to slightly below 800 mL min(-1) for the 5 mg dose. Therefore, the elimination of rizatriptan appears somewhat dose dependent at the high end of this dose range. Mean plasma half-life (t1/2) was 1.5-2.2 h across all doses while mean residence time in the body (MRT) and steady state volume of distribution (Vss) of rizatriptan remained relatively invariant across doses. Urinary excretion of rizatriptan (Ue) ranged from 14.5 to 34.6% of dose.

Species-specific oligonucleotides for enumeration of Pseudomonas putida F1, Burkholderia sp. strain JS150, and Bacillus subtilis ATCC 7003 in biodegradation experiments

Species-specific sequences were identified within the V4 variable region of 16S rRNA of two bacterial species capable of aromatic hydrocarbon metabolism, Pseudomonas putida F1 and Burkholderia sp. strain JS150, and a third, Bacillus subtilis ATCC 7003, that can function as a secondary degrader. Fluorescent in situ hybridization (FISH) with species-specific oligonucleotides was used for direct counting of these species throughout a phenol biodegradation experiment in batch culture. Traditional differential plate counting methods could not be used due to the similar metabolism and interactions of the primary degraders and difficulties in selecting secondary degraders in mixed culture. In contrast, the FISH method provided reliable quantitative results without interference from those factors.

Determination of pilocarpic acid in human plasma by capillary gas chromatography with mass-selective detection

A novel, highly sensitive method for the determination of pilocarpic acid (PA) in human plasma is described. In addition, the method provides for the conversion of the lactone, pilocarpine (P), to PA so that a total drug presence can be determined. Using novel high-performance liquid chromatographic conditions capable of separating P, isopilocarpine (I-P), PA and isopilocarpic acid (I-PA) from each other and from endogenous plasma impurities, it was confirmed that P exclusively and quantitatively converts to PA in heparinized human plasma during storage. For the determination of PA, the selective extraction of PA from protein-free plasma was accomplished using two different solid-phase extraction (SPE) cartridges in two consecutive SPE steps. After extraction, PA was lactonized with trifluoroacetic acid back to P, and both P and an internal standard were acylated using heptafluorobutyric anhydride (HFBA). The trifluoroacetylated derivatives were monitored using gas chromatography (GC) with mass spectrometric (MS) detection. This procedure allowed the sensitive and reliable determination of PA with a limit of quantification (LOQ) of 1 ng/ml, which could not be achieved using previously described methods. The assay was validated in the concentration range of 1 to 10 ng/ml with an intra-day precision (expressed as the coefficient of variation, C.V.) ranging from 9.9 to 0.5%. Inter-day precision for the quality control standard at 2.5 ng/ml showed a C.V. of 10.2%. Accuracy ranged from 94 to 102%. The assay was used to monitor the maximum systemic exposure to P, administered by the ocular route, in terms of total plasma PA (P and PA).

Sri Lanka. Political violence and ethnic conflict

In recent years, Sri Lanka has experienced 2 violent rebellions in which youths have played a prominent role, 1 in the majority Sinhala community and 1 in the minority Tamil community. The former was crushed, but the latter remains ongoing, with the Liberation Tigers of Tamil Eelam, who claim to represent the Tamil minority, battling the Sinhala-dominated government. Prospects for peace in the short- and medium term appear poor. These events have generated an impressive body of interdisciplinary interpretation, but several important topics have received relatively little attention. Most ongoing research is being carried out by anthropologists, historians, and political scientists, but psychological insights would offer important complementary perspectives.