Search

The synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor 3 is described. This complex structure contains a tetrazole modified by a chiral hemiaminal carbonate prodrug. A reg...

High-throughput experimentation (HTE) has revolutionized the pharmaceutical industry, most notably allowing for rapid screening of compound libraries against therapeutic targets. The past decade ha...

Indole acids 1, 2, and 3 are potent 5′-adenosine monophosphate-activated protein kinase (AMPK) activators for the potential treatment of diabetic nephropathy. Compounds 1–3 were scaled to supply material for preclinical studies, and indole 3 was selected for advancement to first-in-human clinical trials and scaled to kilogram quantities. The progression of the synthesis strategy for these AMPK activators is described, as routes were selected for efficient structure–activity relationship generation and then improved for larger scales. The developed sequences employed practical isolations of intermediates and APIs, reproducible cross-coupling, hydrolysis, and other transformations, and enhanced safety and purity profiles and led to the production of 40–50 g of 1 and 2 and 2.4 kg of 3. Multiple polymorphs of 3 were observed, and conditions for the reproducible formation of crystalline material suitable for clinical development were identified.

Driven by the ever-increasing pace of drug discovery and the need to push the boundaries of unexplored chemical space, medicinal chemists are routinely turning to unusual strained bioisosteres such as bicyclo[1.1.1]pentane, azetidine, and cyclobutane to modify their lead compounds. Too often, however, the difficulty of installing these fragments surpasses the challenges posed even by the construction of the parent drug scaffold. This full account describes the development and application of a general strategy where spring-loaded, strained C–C and C–N bonds react with amines to allow for the “any-stage” installation of small, strained ring systems. In addition to the functionalization of small building blocks and late-stage intermediates, the methodology has been applied to bioconjugation and peptide labeling. For the first time, the stereospecific strain-release “cyclopentylation” of amines, alcohols, thiols, carboxylic acids, and other heteroatoms is introduced. This report describes the development, synthesis, scope of reaction, bioconjugation, and synthetic comparisons of four new chiral “cyclopentylation” reagents.

We examined the distribution and co-occurrence of the exotic digenetic trematode Centrocestus formosanus, its exotic intermediate host the red-rim melania snail Melanoides tuberculatus, and rates of infection of fish in 10 spring systems throughout western Texas during 1999 and 2011. Four of the spring systems (East Sandia Springs, Independence Creek, Big Bend National Park Refugium Pond, and Clear Creek) did not contain red-rim melania snails in 1999 and 2011. Four spring systems that were populated with snails (San Felipe Creek, San Solomon Springs, Phantom Lake, and Diamond Y Springs) contained the trematode and were positive for branchial infection in fish except Diamond Y Springs which contained uninfected snails and fish. Since 1999, two additional spring systems, Pinto Creek and Devils River, contained the trematode. We found a high prevalence of branchial infection for fish collected regardless of species. Seventeen of the 21 species of fish collected from the spring systems were positive...

The development and optimization of a scalable synthesis of sodium-dependent glucose cotransporter 2 inhibitor, ertugliflozin, for the treatment of type-2 diabetes is described. Highlights of the chemistry are a concise, four-step synthesis of a structurally complex API from known intermediate 4 via persilylation–selective monodesilylation, primary alcohol oxidation, aldol-crossed-Cannizzaro reaction, and solid-phase acid-catalyzed bicyclic ketal formation. The final API was isolated as the l-pyroglutamic acid cocrystal.

Here, we report the complete genome of a novel aquareovirus isolated from clinically normal fountain darters, Etheostoma fonticola , inhabiting the San Marcos River, Texas, USA. The complete genome consists of 23,958 bp consisting of 11 segments that range from 783 bp (S11) to 3,866 bp (S1).

The discovery of antidiabetic agent ertugliflozin is described. The compound belongs to a new class of SGLT2 inhibitors bearing a dioxa-bicyclo[3.2.1]octane motif. This article describes the critical role that organic synthesis played in both influencing our medicinal chemistry strategy and speeding up the progression of our program.

We report a modular three-component dynamic kinetic resolution (DKR) that affords enantiomerically enriched hemiaminal esters derived from azoles and aldehydes. The novel and scalable reaction can be used to synthesize valuable substituted azoles in a regioselective manner by capping (e.g., acylation) of the equilibrating azole-aldehyde adduct. With the use of a prolinol-derived DMAP catalyst as the chiral Lewis base, the products can be obtained in high chemical yield and with high enantiomeric excess. The DKR was performed on a multikilogram scale to produce a tetrazole prodrug fragment for a leading clinical candidate that posed formidable synthesis challenges.

We report a modular three-component dynamic kinetic resolution (DKR) that affords enantiomerically enriched hemiaminal esters derived from azoles and aldehydes. The novel and scalable reaction can be used to synthesize valuable substituted azoles in a regioselective manner by capping (e.g., acylation) of the equilibrating azole-aldehyde adduct. With the use of a prolinol-derived DMAP catalyst as the chiral Lewis base, the products can be obtained in high chemical yield and with high enantiomeric excess. The DKR was performed on a multikilogram scale to produce a tetrazole prodrug fragment for a leading clinical candidate that posed formidable synthesis challenges.

Opening one ring to tack on another Curious chemists have long sought to learn just how tightly carbon atoms can be bound together. For instance, it's possible to form a bond between two opposite corners of an already strained four-membered ring to make an edge-sharing pair of triangles. Gianatassio et al. have now devised a general use for these and related molecular curiosities. They show that appropriately modified nitrogen centers can pop open the most highly strained bond, leaving the more modestly strained ring motif intact. In this way, small rings can emerge as a convenient diversifying element in compounds, including new pharmaceutical candidates. Science , this issue p. 241

Process development and the multikilogram synthesis of a novel azetidinyl ketolide antibiotic is described. Starting with clarithromycin, the eight-step synthesis features several telescoped operations and direct isolations, which results in a significant improvement in throughput and a major reduction in solvent usage and waste stream volume over the first scale-up campaign. Particular highlights of this effort include the development of an efficient synthesis of 3-hydroxy-1,5-naphthyridine-4-carbaldehyde via a Skraup process and engineering a robust final API synthesis. We also discovered a crystalline monotosylate salt that addressed significant formulation and degradation issues experienced when using the noncrystalline freebase.

Ice-water and salt treatments were evaluated for disinfection of small immersible fisheries equipment contaminated with a nonindigenous tropical snail, the red-rim melania Melanoides tuberculatus. This introduced species can displace native snails and transmit trematodes directly to fish and indirectly to other animals, including humans. The red-rim melania has a well-developed operculum that protects it from desiccation and allows it to remain viable for days on dry fisheries equipment. Treatments were produced by adding 10 kg of salt and 33.3 kg of ice to 66.6 L of water (salt–ice-water [SIW]) or by adding 40 kg of ice to 32 L of water (ice-water only [IW]) and were tested for various periods (0.17 min to 24 h) to find exposures that would kill 100% of the treated snails. Temperatures produced in the test containers ranged from −6.3°C to −2.4°C for SIW and from 0°C to 4.9°C for IW. The survival of snails in saltwater-only (SW) treatments (10 kg of NaCl in 100 L of water) was also tested. Three ...

CE-178,253 benzenesulfonate (1) is a CB1 antagonist discovered by Pfizer medicinal chemists. Two syntheses of this compound are described. The first, based on the discovery synthesis, involves assembly of an aryl-substituted pyrazolotriazine core onto which the second aryl moiety is installed by a Suzuki coupling; this route has been scaled to provide up to 6 kg of API. A second, more convergent route is also described, which installs the pyrazolotriazine containing both aryl substituents by condensation of a bromoketone with a substituted thiosemicarbazide. This route has been demonstrated on laboratory scale and is viewed as the preferred bond-forming sequence.

The red-rim melania Melanoides tuberculata, a subtropical and tropical snail, is a nonindigenous species that has become established and is spreading in the United States. Of concern is the potential of the red-rim melania to displace native snail populations and to transmit trematodes that cause serious problems. One of these, a fish gill trematode, Centrocestus formosanus, has negatively affected U.S. commercial and wild fish stocks, including some endangered species. The snail has an operculum that can protect it from desiccation and can remain viable for days on dry fisheries equipment. Thus, contaminated fisheries equipment is suspected as one of the ways the snail is being moved from place to place. A study was conducted to find chemical treatments that would kill 100% of the red-rim melania. Thirteen different chemicals and chemical combinations were evaluated at different concentrations and for various exposure periods. Roccal-D-Plus, Hydrothol 191, niclosamide, and Virkon showed promise ...

We assessed the effects of fluctuating temperature and gill parasitism on egg and larval production of the endangered fountain darter (Etheostoma fonticola). Fountain darters, with and without the exotic digenetic trematode Centrocestus formosanus. were exposed in the laboratory to constant (24°C) and fluctuating (24 to 26°C, 26 to 28°C, and 28 to 30°C) water temperatures for 21 d. No differences were detected between the number of eggs produced (P = 0.78) or number of larvae produced (P = 0.11) between fountain darters with and without trematodes. Total egg production was greatest at 24°C and decreased (P < 0.05) by 42% at fluctuating temperature of 24 to 26°C, 65% at fluctuating temperature of 26 to 28°C, and 99.6% at fluctuating temperature of 28 to 30°C. Likewise, larval production was greatest at 24°C and decreased (P < 0.05) by 63% at 24 to 26°C 99.9% at 26 to 28°C, and 100% at 28 to 30°C. Water temperature (24 to 26°C) that fluctuated within previously considered optimum temperature (< 27°...

We determined infestation rates for dead and surviving larval, juvenile, and adult fountain darters (Etheostoma fonticola) exposed to an exotic trematode, Centrocestus formosanus. Estimates from survival curves indicated that 50% of the larval fish (total length 9 to 13 mm) would die within 116 minutes and 50% of the juvenile fish (16 to 20 mm) within 330 minutes when exposed to approximately 555,000 cercariae/L. Less than 25% of the adult fish (36 to 41 mm) had died in 8 h of exposure. Number of metacercariae that caused mortality was directly related (P < 0.01) to fish length, although length alone did not explain the accelerated rate of mortality observed in smaller fish. Varying degrees of trematode tolerance among size groups suggested that larval and juvenile fish were more susceptible to mortality induced by C. formosanus infection than adults. This result has implications for population health as greater mortality in smaller fountain darters could limit the number of fish reaching sexual ...

Centrocestus formosanus, the gill trematode, has caused serious losses among fish raised by tropical fish producers since the early 1980s and is believed to be harmful to wild fish populations, including the federally listed endangered fountain darter (Etheostoma fonticola), in the Comal River near San Marcos, Texas. The parasite appears to infect in many fishes from Hawaii, Florida, Texas, and Utah. The gill trematode has a complex life cycle involving definitive hosts (aquatic birds and occasionally some mammals) and intermediate hosts (aquatic snails and several fish species). In the United States, the green heron (Butorides virescens) and the great egret (Ardea alba) serve as definitive hosts. The first intermediate host, the red-rim melania (Melanoides tuberculatus), an exotic snail, has been found in 15 southern and western states. This snail exhibits resistance to desiccation, molluscicides, and disinfectants and has been documented to out-compete established mollusks. Both the gill tremat...

The synthesis of the anti-cancer compound 2-methoxy-N-(3-{4-[3-methyl-4-(6-methyl-pyridin-3-yloxy)phenylamino]quinazolin-6-yl}-E-allyl)acetamide (CP-724,714) (1) on multikilogram scale using several different synthetic routes is described. Application of the Sonogashira, Suzuki, and Heck couplings to this synthesis was investigated to identify a safe, environmentally friendly, and robust process for the production of this drug candidate. A convergent and selective synthesis of the candidate was identified which utilizes a Heck coupling of a protected allylamine to install the critical olefin.

The red-rim melania Melanoides tuberculatus (family Thiaridae), a tropical, nonindigenous aquatic snail, has become established and is spreading in the United States. Concerns associated with the spread of this snail include its potential to displace native snail populations and to transmit trematodes. Of particular concern is the gill trematode Centrocestus formosanus now found in U.S. commercial and wild fish stocks. The snail survives year-round in subtropical ponds and constant-temperature spring runs in Florida and Texas and in geothermal waters of several western and midwestern states. Knowledge of the temperature tolerances of the snail will increase the ability to predict its potential range in North American waters and to control its spread. Under constant temperature conditions in the laboratory, all red-rim melania (15–25 mm shell height (SH)) were killed by exposure to 5°C for 1 d, 9°C for 2 d, 11°C for 8 d, and 13°C for 12 d. At 17°C and 32.5°C, about 10% of the snails died within 27...

Past disturbance of eggs or larvae of dusky darters Percina sciera has resulted in almost 100% mortality of the larvae within 9 d of hatch. Photoperiod and water temperature were manipulated to induce dusky darters collected from the wild to spawn in the laboratory. Eggs spawned in gravel spawning trays were transferred while in the trays to specially designed egg incubators. Dusky darter larvae were collected after they emerged from the gravel and swam out of the incubator. Groups of larvae were offered ground TetraMin (≤0.3 mm), zooplankton (≤0.3 mm), or a combination of both foods in aquariums that had circulated or noncirculated water. The highest mean survival per treatment was for zooplankton and no circulation (71%); the lowest mean survival was for TetraMin with no circulation (3%). A dusky darter growth curve from egg to first spawn, approximately 1 year, was developed. Dusky darters reared in the laboratory from eggs were successfully spawned.

Five of 18 blackside darter Percina maculata larvae and 3 of 18 leopard darter P. pantherina larvae collected in light traps from the Glover River, McCurtain County, Oklahoma, contained ingested items. The maximum diameter of prey ingested was between 0.27 and 0.37 mm and was 70–90% of their gape widths. None of the larvae that contained prey items possessed a visible yolk sac. Forty-three of 48 laboratory-reared larval dusky darters P. sciera offered zooplankton (≤0.30 mm in diameter; harvested from hatchery ponds) contained ingested items. The dominant prey was Ceriodaphnia spp. adults and neonates. The maximum number of Ceriodaphnia consumed by an individual larva was 20. Calanoid copepods were abundant in the zooplankton offered but were not found in any but the 18-d-old larvae. Rotifers in low densities also were offered, but none were observed in any of the alimentary canals. We conclude that small (≤0.30-mm), pond- reared cladocerans such as Ceriodaphnia and Bosmina are suitable food for t...

Centrocestus formosanus, an exotic digenetic trematode that was recently found infecting wild fish in Texas, was evaluated to determine whether it could infect four propagated warmwater fish species. Channel catfish Ictalurus punctatus, sunshine bass (the hybrid of female white bass Morone chrysops and male striped bass Morone saxatilis), golden shiners Notemigonus crysoleucas, and fathead minnows Pimephales promelas were experimentally infected with cercariae of C. formosanus. The trematodes were embedded along the gill filament cartilage. Cyst production, cartilage displacement, and hyperplasia of the lamellar epithelium were observed in wet mounts of sunshine bass and fathead minnow gills. These pathological changes also occurred in golden shiners and channel catfish but appeared to be delayed and less pronounced. Histological examination showed that the parasites were encased in cartilage, and distorted areas were evident in the filament cartilage. Because this trematode has the ability to in...

Gills of 194 fountain darters Etheostoma fonticola collected from the Comal River in Texas from May 1997 through May 1998 were found to be parasitized with 8–1,524 metacercarial cysts of a heterophyid trematode tentatively identified as Centrocestus formosanus. The intensity of infection varied among three sites on the Comal River. In contrast, of 130 darters from the nearby San Marcos River that were examined, only 4 (3%) were infected, and these had 1–2 cysts per fish. Of 2,279 Melanoides tuberculata snails from the Comal River that were examined, 139 (6.1%) were infected with the trematode. Only 1 snail in 2,241 from the San Marcos River that were examined was infected. The presence of metacercariae in darters was associated with flared opercula, shortened or thickened gill filaments, epithelial hyperplasia, and engorged lamellae. The normal cartilage support of the filaments was distorted and displaced, leading to severe deformities of filament structure. Gill damage was severe and possibly l...

Palladium-catalyzed rearrangement of the deuterium labeled vinylogous carbonate 1 furnished the β-formyl esters 3a/b in 68% yield, while the Z-vinylogous sulfonate (Z-VINS) 2 under analogous reaction conditions led to reversible O-alkylation and isomerization to afford the E-VINS 4a/b in 61% yield. This observation prompted the development of the vinylogous sulfonate as an improved leaving group for a variety of palladium-catalyzed allylic substitution reactions.

Studies were conducted to determine the effects of water temperature on egg and larval production, larval survival, and juvenile growth of the endangered fountain darter Etheostoma fonticola. Adult fish were exposed to water temperatures of 14, 17, 20, 23 (control), 25, 27, and 29°C for 33 d. Egg production was significantly higher (P ≤ 0.05) for fish held at 14, 17, 20, 23, and 25°C than for fish held at 27 and 29°C. Percent hatch was significantly higher (P ≤ 0.05) at 17, 20, and 23°C than at 14, 25, 27, and 29°C. Larval production was significantly higher (P ≤ 0.05) at 14, 17, 20, and 23°C than at 25, 27, and 29°C. Estimated low and high temperatures to produce 50% mortality of larvae (24–72 h old) over a 24-h period were 3.8 and 31.9°C, respectively. Low survival and substantial variation in growth of controls prevented a meaningful assessment of temperature effects on juvenile growth.

Temperature (5–25°C) and photoperiod (daylight of 10–14 h) were manipulated to induce spawning in groups and individual pairs of longnose darters Percina nasuta. The fish were maintained in tanks for up to 6 years and were fed blackworms, zooplankton, and aquatic insects harvested from hatchery ponds. The fish were spawned four times between June 1994 and February 1996. Eight females released over 3,400 eggs, of which 73% were deposited on Spawntex mats. Various incubation methods were used, and 706 fry (20% hatch) were produced. Fry were offered brine shrimp Artemia sp., copepods, and cladocerans (0.053–0.212 mm in diameter) and rotifers (0.053–0.106 mm in diameter) under various culture conditions. Mortality of fry was 100% within 9 d.

A streamlined process for the synthesis of 3-amino-1-benzhydrylazetidine is described. Commercially available 1-benzhydrylazetidin-3-ol was reacted with methanesulfonyl chloride in the presence of triethylamine in acetonitrile, upon quench with water, the mesylate intermediate (3) was isolated by filtration. The wet filter cake was subsequently treated with ammonium hydroxide/isopropanol in a Parr reactor at ∼70°C. The procedure afforded the titled compound as mono acetate salt in 72–84% yield.

Treatment of 1,4-dimethoxynaphthalenes with iodosobenzene diacetate and trimethylsilyl chloride or bromide furnished the haloacetoxylated, acetoxylated, and halogenated 1,4-dimethoxynaphthalenes in excellent yield. The reaction pathway for each transformation was shown to be a function of reagent stoichiometry. A mechanistic hypothesis is presented that rationalizes the reaction pathways and explains the subtle differences in the halogenation reactions. The acetoxylation, for example, is thought to involve the formation of an iodonium ion that promotes the nucleophilic addition of acetate ion and subsequent 1,2-acetyl migration. Bromination occurs as a direct result of the oxidation of trimethylsilyl bromide to bromine, followed by electrophilic aromatic substitution. Chlorination is thought to proceed via a radical process and not the formation of molecular chlorine from the dissociation of iodosobenzene dichloride. The haloacetoxylation reaction also appears to be fairly specific for 1,4-dimethoxynaphth...

To describe current practice regarding the use of physician extenders (PEs) and the "fast track" (FT) concept in United States emergency departments (EDs), a telephone survey of 250 US health care facilities offering emergency services was conducted. Of the EDs surveyed, 21.6% were using PEs at the time of the survey, and of those not using PEs, 23.5% intended to do so within the next 2 years. Those using PEs had been using them for a mean duration of 3.5 years (the mode was 2 years). The mean number of hours of PE coverage was 11.4 hours on weekdays and 11.5 hours on weekends (the mode was 12 hours both on weekdays and weekends). In general, the use of PEs increased with increasing hospital size and ED census, in more urban settings, in teaching facilities, and in the Northeast region of the country. Thirty percent of EDs surveyed had FT, and of those that did not have FT at the time of the survey, 32.8% intended to institute FT within 2 years. Of those that had FT, the mean number of years in use was 2.4 (the mode was 2). The use of FT increased with increasing hospital size and ED census, in teaching hospitals, and in the Northeast region. FT was most common in the suburban setting. The mean estimated percentage of ED patients going through FT was 30.1%. The mean number of hours per day of FT operation was 13.4 hours on weekdays and 13.7 hours on weekends (the mode was 12 hours/day both on weekdays and weekends). Of hospitals using PEs in the ED, 56.0% had FT; of hospitals without PEs in the ED, 23.5% had FT.

SUMMARYCentrocestus formosanus is a digenetic trematode from Asia that parasitizes multiple hosts and is a concern in the Comal River, Texas, USA, because of its negative effects on the endangered fountain darter Etheostoma fonticola. To determine a practical sampling method to monitor C. formosanus in the Comal River, we evaluated three sampling methods using wild-caught fish, caged fish reared in the laboratory, and cercariometry. Cercariometry detected significant spatial and temporal patterns of cercarial density in river water that were similar with metacercarial intensity in caged fish, but inconsistent with metacercarial intensity in wild-caught fish. Our results also showed a positive correlation between cercarial density in river water and metacercarial intensity in caged fish. Conversely, the relationship was not significant between cercarial density and metacercarial intensity in wild-caught fish. Because cercariometry predicted similar trends with the caged fountain darter sampling method, cercariometry was useful in predicting C. formosanus gill infections, infection rate, and longevity in infected fountain darters. Although trends from cercariometry and caged fish sampling methods were similar, we recommend cercariometry because it was less expensive to use given the amount of sampling effort required and provides trends that can be used to make pro-active management decisions in C. formosanus-infested aquatic ecosystems.

Treatment of 1,3-diphenyl-2-propenyl acetate 1 with the sodium salt of dimethyl malonate and the palladium complex of the phosphino-1,3-oxazine ligand cis-3a gave the allylic substitution product 2 in 99% yield and 95% enantiomeric excess.

Treatment of 1,4-dimethoxynaphthalenes with iodosobenzene and trimethylsilyl chloride or bromide furnished the corresponding 2,3-haloacetoxylated-1,4-dimethoxynaphthalenes.

The palladium catalyzed cross-coupling of the organozinc reagent derived from 2-bromobenzaldehyde ethylene ketal 4 with the acyl chlorides 5 and 8 provides an expeditious route to the BCD 2 and BDCE 2 ring systems of Fredericamycin A 1 .

Toxicity tests evaluated chronic and sublethal effects of fog oil (FO) on a freshwater endangered fish. FO is released during military training as an obscurant smoke that can drift into aquatic habitats. Fountain darters, Etheostoma fonticola, of four distinct life stages were exposed under laboratory conditions to three forms of FO. FO was vaporized into smoke and allowed to settle onto water, violently agitated with water, and dosed onto water followed by photo-oxidization by ultraviolet irradiation. Single smoke exposures of spawning adult fish did not affect egg production, egg viability, or adult fish survival in 21-day tests. Multiple daily smoke exposures induced mortality after 5 days for larvae fish. Larvae and juvenile fish were more sensitive than eggs in 96-h lethal concentration (LC50) tests with FO–water mixtures and photo-oxidized FO. Water-soluble FO components photo-modified by ultraviolet radiation were the most toxic, thus indicating the value of examining weathering and aging of chemicals for the best determination of environmental impact.

We examined the gills of wild fish collected from central Texas for Centrocestus formosanus metacercariae to determine whether this temperature-restricted parasite had invaded the thermally dynamic Guadalupe River via an introduced population in its thermally stable tributary, the Comal River. We collected fish from three sites in the Guadalupe River near its confluence with the Comal River (upstream, at, and downstream) and one site in the Comal River. Centrocestus formosanus infected 14 of the 25 species examined (56.0%) and 171 of the individual fish (27.1%). Several of the infected fish represent new host records for the parasite, and two are listed as species of special concern by the state of Texas. Mean metacercarial intensities varied from 8 to 616 among species, and the highest recorded intensity was greater than 800 in two Guadalupe roundnose minnow Dionda nigrotaeniata. Among the 24 species examined from the Guadalupe River, 11 (45.8%) were infected with C. formosanus. Thorough surveys at the study sites yielded no living specimens of the first obligate intermediate snail host (red-rim melania Melanoides tuberculatus), which must be present to perpetuate the parasite. Thus, the infections were probably due to drifting cercariae that had been shed into the water column upstream of the study area in the Comal River. We therefore investigated spatial patterns in cercarial acquisition using caged fish to determine whether drifting cercariae were present in the water column at the study sites. Of 57 uninfected blacktail shiners Cyprinella venusta exposed to Guadalupe River water downstream from and at the confluence, 52 (91.2%) became infected with C. Formosanus metacercariae at a mean rate of 4 metacercariae/d. This finding extends the known geographic range of this invasive exotic parasite and is the first report of the life cycle being advanced in the fish assemblage of a thermally variable temperate stream in the USA.

Annual cycles of growth and reproduction of hatchery–reared Florida largemouth bass, Micropterus salmoides floridanus, were investigated. Animals were raised on either forage (goldfish, Carassius auratus) or a pelleted salmon feed. Male and female year–class 1 largemouth bass were sampled throughout one complete yearly cycle (January–December). A biphasic growth cycle was observed in both forage–fed and pellet–fed fish. No increase in body length or weight was observed until approximately midway through the spawning period (May), after which fish grew at a consistent rate for the remainder of the study. The reproductive cycle of forage–fed fish was characterized by a rapid increase in gonadosomatic index (GS1) between January and April, followed by a prolonged spawning period (April–July) during which GSI progressively declined. Fully regressed gonads were observed in September and October, and a resumption of gonadal recrudescence was observed between October and December. Visceral adipose deposits (expressed as mesenteric fat index; MFI) were resorbed during gonadal growth and the initial stages of the spawning period, and restored during the post–spawning phase. Fish raised on pelleted feed had growth and reproductive cycles that parallelled those of forage–fed fish, but several significant differences were observed between the two diet groups. During the growth phase of the cycle, pellet–fed largemouth bass grew significantly faster than forage–fed largemouth bass, and had significantly larger MFIs than forage–fed largemouth bass at all times of the year. Pellet–fed fish also had significantly larger GSIs than forage–fed fish. These data indicate that diet composition may be an important determinant of growth and reproductive function in this species.

Compound 4 (PF-04971729) belongs to a new class of potent and selective sodium-dependent glucose cotransporter 2 inhibitors incorporating a unique dioxa-bicyclo[3.2.1]octane (bridged ketal) ring system. In this paper we present the design, synthesis, preclinical evaluation, and human dose predictions related to 4. This compound demonstrated robust urinary glucose excretion in rats and an excellent preclinical safety profile. It is currently in phase 2 clinical trials and is being evaluated for the treatment of type 2 diabetes.

Survival of the fountain darter (Etheostoma fonticola), a U.S. federally listed endangered species, may depend on captive propagation. Studies were conducted to determine the effect of temperature on spawning and to develop methods for culture. The fountain darter spawned and produced viable offspring in aquaria at 27, 24, 21, 18, 15, 12, 9, and 6°C. The fish also spawned at 3 and 30°C but did not produce viable eggs. Daily egg production of individual fish held at 27, 21, 15, and 9°C was variable. The mean critical thermal maximum for the fountain darter was 34.8°C. Early life stages, 4–14 mm long, were offered a variety of live protozoans, rotifers, and microcrustaceans. Food selection varied with fish size and food size. Fountain darters reached sexual maturity in about 180 d when maintained at 21°C. Three-year-old darters produced viable offspring, and several lived longer than 4 years. Tricaine methanesulfonate was an effective anesthetic at 60 mg/L but was fatal to subadults at 100 mg/L.

Several acclimation periods and hormone treatments were tried to determine their effects on controlled spawning of 2-year-old Florida largemouth bass (Micropterus salmoides floridanus). During the first season, fish were acclimated to raceways for 0–8 weeks before spawning; males and females were separated during acclimation. There was an inverse relationship between the length of the acclimation period and latency of first spawn after the sexes were mixed. The longest acclimation periods resulted in the shortest latencies; however, once spawning began, the rate of spawning (interval between spawns) was similar across treatments. During the second season, unacclimated and 2-week-acclimated largemouth bass were injected with saline, human chorionic gonadotropin (HCG; 4,000 IU/kg body weight) or [D-ala6pro9-N-ethylamide]-luteinizing hormone releasing hormone (LHRH-A; 0.5 mg/kg body weight). Injections of HCG induced spawning quicker, and produced more spawns and fry, than injections of LHRH-A or sa...

Clot dissolution with restoration of infarct-related artery blood flow is the likely mechanism for the improved prognosis and mortality reduction seen after thrombolytic therapy of acute myocardial infarction. A pilot study has suggested that 100 mg of recombinant tissue-type plasminogen activator (rt-PA) infused over 90 min may lead to higher patency rates than the current standard of 100 mg over 3 h. In this multicenter, randomized, open label trial, 281 patients with acute myocardial infarction received 100 mg of rt-PA according to either the standard 3-h infusion regimen (an initial 10-mg bolus followed by 50 mg for the 1st h, then 20 mg/h for 2 h) or an accelerated 90-min regimen (15-mg bolus followed by 50 mg over 30 min, then 35 mg over 60 min). All patients also received intravenous heparin and oral aspirin during and alter rt-PA infusion.At 60 min after initiation of the rt-PA infusion, the observed angiographic patency rates were 76% (95% confidence intervals 65% to 84%) in the accelerated regimen group and 63% in the control group (52% to 73%, p = 0.03). At 90 min these rates were 81% (73% to 87%) and 77% (68% to 84%). respectively (p = 0.21). Both randomized groups experienced similar rates of recurrent ischemia, reinfarction, angiographic reocclusion, other complications of myocardial infarction (including stroke and death) and bleeding complications. Fifteen percent of the patients who had a patent artery at 60 min had recurrent ischemia compared with 33% of those who had an occluded artery at 60 min and a patent artery at 90 min.These data indicate that an accelerated 100-mg dose of rt-PA. can produce more rapid reperfusion rates without an apparent change in the safety profile from the standard regimen. Subset analysis suggests that different serial angiographic profiles may predict different prognoses. Larger trials will determine whether increasing the frequency and speed of reperfusion will lead to improved prognosis after myocardial infarction.

The E- and Z-vinylogous sulfonates of β-phenylcinnamyl alcohol derivatives 1 and 2 undergo rapid and enantioselective palladium-catalyzed allylic alkylation (≥90% ee) with the palladium complex of ...

An analytical method for the determination of albendazole (ABZ) residues in bovine milk was developed using one of its major metabolites, albendazole-2-aminosulfone (ABZ2NH2) as the marker. The method involved acid hydrolysis of milk followed by liquid-liquid extraction and solid-liquid phase clean-up of the extract. A reversed-phase HPLC with fluorometric detection was used to quantitate the marker residue. The method exhibited a high degree of precision and good accuracy as demonstrated by a relative standard deviation (R.S.D.) < 5% for the replicate analyses and 91.8 to 104.1% recovery of the fortification level (25-200 ng/ml), respectively. The ratio of the concentrations of the marker and total residues in milk over a 36-120 h withdrawal period was found to be steady at 43.1 indicating a definite relationship between the marker and the total residues of ABZ. The analytical method was used successfully to determine total residues in milk of cattle treated with ABZ.

Thirteen diets were offered to largemouth bass (Micropterus salmoides) fry (10 mm long and larger) for nine or more days. Survival was used as an indication of feed acceptance. Whole eggs of common carp (Cyprinus carpio) were used as the control diet. Five prepared diets contained from 10 to 97% carp eggs. Seven other diets contained a variety of ingredients and were of various feed types: dry pellets, semimoist pellets, moist pellets, and flakes. Carp eggs, collected over several months, were fed to determine if maturity of eggs had any effect on acceptance. Washings and extracts from several fishery products were tested as fry attractants. Diets containing 97-100% carp eggs were the only diets that were well accepted (supporting 56-81% survival) by the fry. The only other diet that resulted in more than 4% survival was a commercially available flaked fish food (18% survival). Maturity of carp eggs did not affect acceptance by fry. Largemouth bass fry exhibited no noticeable attraction to the wa...

The potential impact of commercial bait harvest from small streams was studied in Rich Creek, West Virginia. A mail survey and personal interviews of bait dealers in the mountain areas of this state established typical harvest pressures exerted by commercial operations. Bait fish and crayfish in 50-m sections of Rich Creek were harvested three times every two weeks from May 15 until September 15, 1973, via seine and minnow traps. Treatments consisted of no harvest, a harvest simulating a typical bait dealer, and a harvest pressure twice that of a commercial dealer; all treatments were in triplicate. The effects of the harvests were determined by comparisons over time within treatments, comparisons between treatments and comparisons with final population indices. No significant differences in these comparisons were found to occur for the bait species or for the game fish species inhabiting the study sections. The different harvesting pressures did not appear to affect the densities of the bait and...