Crop production in the USA is frequently limited by a lack of pollinators.

Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.

Tension-free vaginal tape versus colposuspension for primary urodynamic stress incontinence: 5-year follow up.

OBJECTIVE: To compare the long-term outcomes of tension-free vaginal tape (TVT) and colposuspension as primary treatment for stress incontinence. STUDY DESIGN: Multicentre randomised controlled trial. SETTING: Secondary and tertiary care gynaecology, urology and urogynaecology departments in 14 centres in the UK and Eire. POPULATION: Women with urodynamically confirmed stress incontinence and who had previously failed to respond to conservative treatment were invited to participate. METHODS: Three hundred and forty-four women were randomised; 175 to TVT and 169 to colposuspension. This paper reports the 5-year outcomes. MAIN OUTCOME MEASURES: The primary outcome at 5 years was a 1-hour perineal pad test; other outcomes included clinical examination, Short Form-36 (SF-36) health status and Bristol Female Lower Urinary Tract Symptoms (BFLUTS) questionnaires. RESULTS: A negative 1-hour pad test was recorded in 58/72 (81%) women in the TVT group and 44/49 (90%) in the colposuspension group (P = 0.21, Fisher's exact test) at 5 years. There was an increase in enterocoele and rectocele in the colposuspension group; three late tape complications were seen in the TVT group. CONCLUSION: This study did not detect a significant difference between TVT and colposuspension for the cure of stress incontinence at 5 years. The effect of both procedures on cure of incontinence and improvement in quality of life is maintained in the long term. Vault and posterior vaginal wall prolapse are seen more commonly after colposuspension. Tape erosion may occur several years after surgery.

Molecular cloning and characterization of the murine bile salt export pump.

Hepatic bile salt secretion and bile formation are essential functions of the mammalian liver, and the rate-limiting step of hepatocellular secretion of bile salts is canalicular secretion. Recently, the rat sister-of-p-glycoprotein/bile salt export pump (spgp/BSEP) was demonstrated to encode for the rat ATP-dependent canalicular bile salt export protein, and mutations of human BSEP were identified as the cause of PFIC 2. Since mouse models are vital for studies in hepatocellular transport and metabolism, cloning and characterization of the murine gene are essential. In this study, we have cloned a full-length, functional cDNA for the mBsep. The deduced amino acid sequence encodes for a 1321-amino-acid protein and is 94% similar to rat and 89% similar to human bsep. Western immunoblotting using an antibody directed against a carboxy-terminal peptide of mbsep protein reveals a 160kDa protein, which is highly enriched in mouse canalicular membranes. Transfection of mBSEP into Sf-9 insect cells or mammalian Balb-3T3 cells confers functional transport of the bile salt taurocholate. The mBsep mRNA is expressed in murine liver, but not in other tissues. Hepatic mBsep levels appear highly regulated, being markedly diminished in both LPS and estrogen models of cholestasis. These data are important for further murine studies of hepatocellular transport physiology and metabolism.

Mammary gland lactose, plasma progesterone and lactogenesis in the marsupial Macropus eugenii.

Mammary gland lactose concentrations in pregnant tammar wallabies remained low at 115 +/- 24 (S.E.M.) micrograms/g wet weight of tissue until immediately before parturition, then increased to 1274 +/- 262 micrograms/g after birth. Concentrations in non-pregnant cyclic animals were generally low (143 +/- 36 micrograms/g), but were raised in three animals around the time of oestrus. Removal of the corpus luteum on day 18 of pregnancy or the oestrous cycle caused an increase in lactose concentrations in both lutectomized and sham-operated animals. This occurred despite a significant lowering of peripheral plasma progesterone concentration in only the lutectomized group. Plasma cortisol concentrations were high in some of these animals, but showed no consistent relationships with the raised lactose concentrations. The increased peripartum lactose concentration normally coincides with a sharp fall in peripheral plasma progesterone concentration, but artificial maintenance of high progesterone levels had no effect on the increase of mammary gland lactose at parturition. Mammary gland lactose concentrations in tammar wallabies are therefore a useful indicator of biosynthetic activity and as an index of lactogenesis but the role, if any, of progesterone withdrawal in lactogenesis remains unclear.

Factors affecting the degradation rate of poly(lactide-co-glycolide) microspheres in vivo and in vitro.

The purpose of this work was to study the degradation of poly(lactide-co-glycolide) (PLG) microspheres in vivo and in vitro. Degradation rate constants were determined by measuring the polymer molecular weight as a function of time by gel-permeation chromatography. The effects of PLG chemistry and the effects of encapsulating the sparingly soluble salt zinc carbonate and the protein recombinant human growth hormone (rhGH) on the degradation rate were assessed. It was found that in vivo degradation was faster than in vitro degradation. In addition, different types of PLGs were found to degrade at different rates depending on the chemistry of the polymer end group and, to a lesser extent, the molecular weight. Finally, zinc carbonate was found to retard the degradation of some PLGs. These degradation studies have proved valuable in the design of sustained release microsphere products.

Biocompatibility of poly (DL-lactide-co-glycolide) microspheres implanted into the brain.

The delivery of therapeutic molecules to the brain has been limited in part due to the presence of the blood-brain barrier. One potential solution is the implantation of biodegradable polymers with sustained release of drugs. Poly (DL-lactide-co-glycolide) (PLG) is a bioerodible polymer with a long and successful history of use as a suture material. More recently, PLG has been investigated for localized and sustained delivery of molecules into both peripheral sites and the brain. Despite its well-defined safety profile for parenteral applications, little information exists concerning the safety of PLG when implanted into the brain. To further characterize the biocompatibility of PLG in the brain, we examined the gliotic response following implants of PLG into the brains of rats. As a control, each animal received an injection of the suspension medium into the contralateral hemisphere. Following implantation, PLG was well tolerated. GFAP-positive astrocytes were observed throughout the cerebral cortex and striatum on both the implanted and control sides, with the reaction being greatest within the heavily myelinated fiber tracts of the corpus callosum. Quantitative analyses revealed that this reaction occurred within 1 h postsurgery, reached its peak at 1 week following surgery, and then decreased markedly by 1 month postsurgery. A minimal gliotic reaction was still present 1 year postsurgery but was localized to the needle tract. No differences in GFAP reactivity were seen between the polymer-implanted and control sides at any time point. Histological analysis determined that the majority of the PLG disappeared between 1 and 4 weeks. A set of parallel studies in which PLG samples were retrieved from the brain at various time points corroborated these findings and determined that the majority of PLG degraded within 2 weeks following implantation. Together, these results demonstrate that PLG is well tolerated following implantation into the CNS and that the astrocytic response to PLG is largely a consequence of the mechanical trauma that occurs during surgery. The biocompatibility of PLG implanted into the CNS provides further support for its use in a wide range of new therapeutic applications for sustained and localized drug delivery to the brain.

Attachment of E. coli-bearing K88 antigen to equine brush-border membranes.

Equine small intestinal brush-border membranes, from 40 adult horses were tested in vitro for the presence of receptors for the Escherichia coli adhesive antigens K88ab, K88ac and K99. Only K88-positive strains of E. coli adhered strongly to horse brush-border membranes. In contrast, a K88-negative mutant strain J2, 2 K99-positive strains and 3 E. coli strains isolated from foals failed to adhere to horse brush-border membranes. Purified K88ac pili when reacted with equine brush-border membranes inhibited to a great extent the adhesion of K88-positive E. coli. Similarly, K88-positive E. coli previously reacted with K88 antibody, did not attach to equine brush-border membranes. Oral inoculation of 4 newborn foals with strains of K88-positive enterotoxigenic E. coli, producing either heat-stable or heat-labile enterotoxin, caused diarrhoea in 1 animal.

Serum chlortetracycline concentrations in parrots fed mediated seed diets.

Various seed diets containing chlortetracycline were fed to large and small parrots to evaluate serum chlortetracycline concentrations. The substitution of dehulled sunflower seed for whole sunflower in the seed mix may have resulted in higher chlortetracycline concentrations in cockatoos and parrots. The serum chlortetracycline concentration achieved for all diets was less than the goal of 1 microgram/mL, but the concentrations attained may be useful for therapy.

Prenatal care utilization in Hawaii: did it improve during the last 16 years?

This paper examines the utilization of prenatal care in Hawaii from 1979 to 1994 to determine if early and adequate utilization of prenatal care has changed during this period. Birth certificates of single live born infants of resident women were the source of data for the study. During the study period, the proportion of women receiving prenatal care in the first trimester increased by nearly 5 percent but was still below the national and state Year 2000 health objective of 90 percent. Notwithstanding this improvement, the percentage of women who did not receive the recommended number of visits in spite of starting care early significantly increased. The overall proportion of women with 'intensive' prenatal care use markedly increased (134.7%). The proportion of women with 'inadequate' care use declined (10.3%), although the proportion of women with 'no care' use doubled. Complete reporting of use of care through birth certificates markedly deteriorated. The findings of this study indicate the need for changes in the targeting and provision of counseling and education on the part of health care providers. Public health leaders, policy makers, health care providers, and advocacy groups need to collectively review programmatic directions with an aim toward the development of innovative approaches to address the emerging health needs of mothers and infants in the state.

Effects of progesterone on parturition in the tammar, Macropus eugenii.

Tammar wallabies were treated with progesterone injections or implants during late pregnancy to determine whether progesterone withdrawal was essential for parturition. Neither physiological (implanted group) nor pharmacological (injected group) levels of circulating progesterone prevented parturition occurring at about the expected time in about two-thirds of animals that were pregnant. The neonates of both groups were normal in size and weight, but about a third of treated pregnant animals retained their fetuses or aborted. The retained fetuses were retarded in development. Therefore, progesterone treatment had no influence on the duration of gestation, or parturition, in the tammar wallaby, but high progesterone concentrations may interfere with the normal course of development and birth in a proportion of treated animals.

Functional expression of a high affinity mammalian hepatic choline/organic cation transporter.

Uptake by the liver of the organic cation and essential nutrient choline is required for the hepatic synthesis of phosphatidylcholine. Uptake of other organic cations is also important for the metabolism and secretion of numerous endobiotics and drugs. Although a high affinity mammalian hepatic choline transporter has been kinetically defined, it has not been previously identified. We have developed stable transfectants of BALB/3T3 cells, using a murine member of the organic cation transporter gene family (mOct1/Slc22a1), and used these cells to characterize the transport of the organic cation choline and model organic cation tetraethylammonium (TEA). Functional expression of mOct1/Slc22a1 in BALB/3T3 cells confers the saturable, temperature-dependent uptake of choline with a K(m) of 42 micrometer, and uptake of TEA with a K(m) of 43 micrometer. We subsequently used our cell culture uptake system to kinetically define in HepG2 cells a high affinity choline uptake process, which transports choline with a K(m) similar to that of mOct1/Slc22a1 protein. We also demonstrated that organic cation transport by mOct1/Slc22a1 is inhibited by several organic cations, and that the gene is expressed in the perinatal period, at a time when phosphatidylcholine synthesis increases. We conclude that mOct1/Slc22a1 encodes a high affinity mammalian hepatic choline/organic cation transporter. This transporter may be important for hepatic phosphatidylcholine synthesis, and for the metabolism and secretion of many organic cationic drugs.

Tension-free vaginal tape for primary genuine stress incontinence: a two-centre follow-up study.

OBJECTIVE: To assess the safety and efficacy of the tension-free vaginal tape procedure in the treatment of primary genuine stress incontinence. PATIENTS AND METHODS: A two-centre follow-up study was conducted on 40 women with urodynamically confirmed primary genuine stress incontinence who had a tension-free vaginal tape inserted under local anaesthesia with sedation. Operative details were recorded and all patients followed up both subjectively, and objectively with repeat urodynamic studies and pad testing. RESULTS: The mean (range) age of the women was 51.1 (33-86) years, the median parity 2 (0-4) and mean body mass index 25.1 (19-35). The mean anaesthesia and operative duration was 42 (25-65) min; 93% of the women resumed immediate spontaneous voiding with no need for catheterization. The mean inpatient stay was 2.2 (2-4) days (where 2 days is equivalent to one night in hospital). The follow-up was conducted at a mean interval of 12.3 (6-24) months. Subjectively, 80% of women were cured and 17.5% significantly improved; objectively, genuine stress incontinence was cured in 95%. Symptomatic postoperative detrusor instability was found in 15% of women and symptoms of voiding dysfunction identified in 5% of women. There were no defects in healing or tape rejection. CONCLUSION: The tension-free vaginal tape procedure is a promising new technique that, in this short-term analysis, appears to be safe and effective. Intra-operative complications are uncommon and both hospital stay and recovery are short. Voiding complications are rare but symptomatic postoperative detrusor instability had an incidence of 15%.