The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice.

The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans.

The pharmacokinetics and metabolism of lumiracoxib in chimeric humanized and murinized FRG mice.

The pharmacokinetics and metabolism of lumiracoxib were studied, after administration of single 10mg/kg oral doses to chimeric liver-humanized and murinized FRG mice. In the chimeric humanized mice, lumiracoxib reached peak observed concentrations in the blood of 1.10±0.08µg/mL at 0.25-0.5h post-dose with an AUCinf of 1.74±0.52µgh/mL and an effective half-life for the drug of 1.42±0.72h (n=3). In the case of the murinized animals peak observed concentrations in the blood were determined as 1.15±0.08µg/mL at 0.25h post-dose with an AUCinf of 1.94±0.22µgh/mL and an effective half-life of 1.28±0.02h (n=3). Analysis of blood indicated only the presence of unchanged lumiracoxib. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles obtained in humanized mice were different compared to murinized animals with e.g., a higher proportion of the dose detected in the form of acyl glucuronide metabolites and much reduced amounts of taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57bl/6J mice and humans, revealed a greater though not complete match between chimeric humanized mice and humans, such that the liver-humanized FRG model may represent a useful approach to assessing the biotransformation of such compounds in humans.

Predicting the diagnosis of autism in adults using the Autism-Spectrum Quotient (AQ) questionnaire.

BACKGROUND: Many adults with autism spectrum disorder (ASD) remain undiagnosed. Specialist assessment clinics enable the detection of these cases, but such services are often overstretched. It has been proposed that unnecessary referrals to these services could be reduced by prioritizing individuals who score highly on the Autism-Spectrum Quotient (AQ), a self-report questionnaire measure of autistic traits. However, the ability of the AQ to predict who will go on to receive a diagnosis of ASD in adults is unclear. METHOD: We studied 476 adults, seen consecutively at a national ASD diagnostic referral service for suspected ASD. We tested AQ scores as predictors of ASD diagnosis made by expert clinicians according to International Classification of Diseases (ICD)-10 criteria, informed by the Autism Diagnostic Observation Schedule-Generic (ADOS-G) and Autism Diagnostic Interview-Revised (ADI-R) assessments. RESULTS: Of the participants, 73% received a clinical diagnosis of ASD. Self-report AQ scores did not significantly predict receipt of a diagnosis. While AQ scores provided high sensitivity of 0.77 [95% confidence interval (CI) 0.72-0.82] and positive predictive value of 0.76 (95% CI 0.70-0.80), the specificity of 0.29 (95% CI 0.20-0.38) and negative predictive value of 0.36 (95% CI 0.22-0.40) were low. Thus, 64% of those who scored below the AQ cut-off were 'false negatives' who did in fact have ASD. Co-morbidity data revealed that generalized anxiety disorder may 'mimic' ASD and inflate AQ scores, leading to false positives. CONCLUSIONS: The AQ's utility for screening referrals was limited in this sample. Recommendations supporting the AQ's role in the assessment of adult ASD, e.g. UK NICE guidelines, may need to be reconsidered.

Clonal diversity in biofilm formation by Enterococcus faecalis in response to environmental stress associated with endodontic irrigants and medicaments.

AIM: To determine whether clonal diversity within E. faecalis affects biofilm formation when exposed to antimicrobial compounds found in endodontic medicaments and irrigants. METHODOLOGY: Five human isolates of E. faecalis were compared; biofilms were grown in microtitre trays in the presence of sodium hypochlorite, calcium hydroxide, chlorhexidine, tetracycline or clindamycin. Biofilms were quantified by staining with crystal violet and optical density determined with a microplate reader. Slime production (an amorphous extracellular matrix comprising polysaccharides, glycoproteins and glycolipids loosely attached to the cell surface) was determined qualitatively by growth on Congo red agar plates. Linear mixed models were used to examine whether medicaments affected biofilm growth of the isolates in the presence of the medicaments or irrigants. RESULTS: Overall, different endodontic antimicrobials significantly altered biofilm growth in E. faecalis isolates. Two E. faecalis isolates significantly (P < 0.0001) increased biofilm formation in the presence of tetracycline and one in the presence of NaOCl (P = 0.018). Qualitatively, slime production also varied between isolates and correlated with biofilm production. CONCLUSIONS: When subjected to sub-minimum inhibitory concentration (MIC) levels of antimicrobial compounds found in endodontic medicaments, E. faecalis isolates demonstrated significant clonal variation in their capacity to form biofilms. Interestingly, there was a correlation between slime production and the ability of isolates to form a biofilm in the presence of antimicrobials. The results indicate that isolates of E. faecalis that form biofilms in response to endodontic medicaments may be more likely to survive endodontic treatment.

Gas chromatography-mass spectrometry method for rapid identification and differentiation of Burkholderia pseudomallei and Burkholderia mallei from each other, Burkholderia thailandensis and several members of the Burkholderia cepacia complex.

AIMS: To develop a simple gas chromatography-mass spectrometry (GC-MS) method for the detection and differentiation of Burkholderia pseudomallei and Burkholderia mallei from each other, Burkholderia thailandensis and several members of the Burkholderia cepacia complex. METHODS AND RESULTS: Biomarkers were generated by one-step thermochemolysis (TCM) and analysed using a GC-MS system. Fragments of poly-3-hydroxybutyrate-co-hydroxyvalerate [poly(3HBA-co-3HVA)] produced by TCM were useful biomarkers. Several cellular fatty acid methyl esters were important in differentiating the various Burkholderia species. A statistical discrimination algorithm was constructed using a combination of biomarkers. The identities of four B. pseudomallei strains, four B. mallei strains and one strain of each near neighbour were confirmed in a statistically designed test using the algorithm. The detection limit for this method was found to be approximately 4000 cells. CONCLUSIONS: The method is fast, accurate and easy to use. The algorithm is robust against different growth conditions (medium and temperature). SIGNIFICANCE AND IMPACT OF THE STUDY: This assay may prove beneficial in a clinical diagnostic setting, where the rapid identification of B. pseudomallei is essential to effective treatment. This method could also be easily employed after a biological attack to confirm the presence of either B. pseudomallei or B. mallei.

Scaffolds with a standardized macro-architecture fabricated from several calcium phosphate ceramics using an indirect rapid prototyping technique.

Calcium phosphate ceramics, commonly applied as bone graft substitutes, are a natural choice of scaffolding material for bone tissue engineering. Evidence shows that the chemical composition, macroporosity and microporosity of these ceramics influences their behavior as bone graft substitutes and bone tissue engineering scaffolds but little has been done to optimize these parameters. One method of optimization is to place focus on a particular parameter by normalizing the influence, as much as possible, of confounding parameters. This is difficult to accomplish with traditional fabrication techniques. In this study we describe a design based rapid prototyping method of manufacturing scaffolds with virtually identical macroporous architectures from different calcium phosphate ceramic compositions. Beta-tricalcium phosphate, hydroxyapatite (at two sintering temperatures) and biphasic calcium phosphate scaffolds were manufactured. The macro- and micro-architectures of the scaffolds were characterized as well as the influence of the manufacturing method on the chemistries of the calcium phosphate compositions. The structural characteristics of the resulting scaffolds were remarkably similar. The manufacturing process had little influence on the composition of the materials except for the consistent but small addition of, or increase in, a beta-tricalcium phosphate phase. Among other applications, scaffolds produced by the method described provide a means of examining the influence of different calcium phosphate compositions while confidently excluding the influence of the macroporous structure of the scaffolds.

Attention to social stimuli and facial identity recognition skills in autism spectrum disorder.

BACKGROUND: Previous research suggests that individuals with autism spectrum disorder (ASD) have a reduced preference for viewing social stimuli in the environment and impaired facial identity recognition. METHODS: Here, we directly tested a link between these two phenomena in 13 ASD children and 13 age-matched typically developing (TD) controls. Eye movements were recorded while participants passively viewed visual scenes containing people and objects. Participants also completed independent matching tasks for faces and objects. RESULTS AND CONCLUSIONS: Behavioural data showed that participants with ASD were impaired on both face- and object-matching tasks relative to TD controls. Eye-tracking data revealed that both groups showed a strong bias to orient towards people. TD children spent proportionally more time looking at people than objects; however, there was no difference in viewing times between people and objects in the ASD group. In the ASD group, an individual's preference for looking first at the people in scenes was associated with level of face recognition ability. Further research is required to determine whether a causal relationship exists between these factors.

Design and fabrication of standardized hydroxyapatite scaffolds with a defined macro-architecture by rapid prototyping for bone-tissue-engineering research.

This investigation describes the production and characterization of calcium phosphate scaffolds with defined and reproducible porous macro-architectures and their preliminary in vitro and in vivo bone-tissue-engineered response. Fugitive wax molds were designed and produced using a rapid prototyping technique. An aqueous hydroxyapatite slurry was cast in these molds. After sintering at 1250 degrees C and then cleaning, dimensional and material characterizations of the scaffolds were performed. The resulting scaffolds represented the design, and their dimensions were remarkably consistent. A texture inherent to the layer-by-layer production of the mold was impressed onto the vertical surfaces of the scaffolds. The surface roughness (R(a)) of the textured surfaces was significantly greater than that of the nontextured surfaces. Material analyses revealed a beta-TCP phase in addition to hydroxyapatite for the molded ceramics. Non-molded control ceramics exhibited only hydroxyapatite. Thirty scaffolds were seeded with culture-expanded goat bone-marrow stromal cells (BMSCs) and implanted subcutaneously in nude mice for 4 or 6 weeks. Histology revealed mineralized bone formation in all the scaffolds for both implantation periods. After 4 weeks, bone was present primarily as a layer on scaffold surfaces. After 6 weeks, the surface bone formation was accompanied by bone budding from the surface and occasional bridging of pores. This budding and bridging bone formation almost always was associated with textured scaffold surfaces. However, the area percentage of bone in pores was similar for the 4- and 6-week implantation periods.

Viable osteogenic cells are obligatory for tissue-engineered ectopic bone formation in goats.

In this study we investigated the bone-forming capacity of tissue-engineered (TE) constructs implanted ectopically in goats. As cell survival is questionable in large animal models, we investigated the significance of vitality, and thus whether living cells instead of only the potentially osteoinductive extracellular matrix are required to achieve bone formation. Vital TE constructs of porous hydroxyapatite (HA) covered with differentiated bone marrow stromal cells (BMSCs) within an extracellular matrix (ECM) were compared with identical constructs that were devitalized before implantation. The devitalized implants did contain the potentially osteoinductive ECM. Furthermore, we evaluated HA impregnated with fresh bone marrow and HA only. Two different types of HA granules with a volume of approximately 40 microm were investigated: HA70/800, a microporous HA with 70% interconnected macroporosity and an average pore size of 800 microm, and HA60/400, a smooth HA with 60% interconnected macropores and an average size of 400 microm. Two granules of each type were combined and then treated as a single unit for cell seeding, implantation, and histology. The tissue-engineered samples were obtained by seeding culture-expanded goat BMSCs on the HA and subsequently culturing these constructs for 6 days to allow cell differentiation and ECM formation. To devitalize, TE constructs were frozen in liquid nitrogen according to a validated protocol. Fresh bone marrow impregnation was performed perioperatively (4 mL per implant unit). All study groups were implanted in bilateral paraspinal muscles. Fluorochromes were administered at three time points to monitor bone mineralization. After 12 weeks the units were explanted and analyzed by histology of nondecalcified sections. Bone formation was present in all vital tissue-engineered implants. None of the other groups showed any bone formation. Histomorphometry indicated that microporous HA70/800 yielded more bone than did HA60/400. Within the newly formed bone, the fluorescent labels showed that mineralization had occurred before 5 weeks of implantation and was directed from the HA surface toward the center of the pores. In conclusion, tissue-engineered bone formation in goats can be achieved only with viable constructs of an appropriate scaffold and sufficient BMSCs.

Evaluating 3D bone tissue engineered constructs with different seeding densities using the alamarBlue assay and the effect on in vivo bone formation.

Bone tissue engineering using patient derived cells seeded onto porous scaffolds has gained much attention in recent years. Evaluating the viability of these 3D constructs is an essential step in optimizing the process. The alamarBlue (aB) assay was evaluated for its potential to follow in vitro cell proliferation on architecturally standardized hydroxyapatite scaffolds. The impact of the aB assayed and seeding density on subsequent in vivo bone formation was investigated. Twelve scaffolds were seeded with various densities from 250 to 2.5x10(6) cells/scaffold and assay by aB at 5 time points during the 7-day culture period. Twelve additional scaffolds were seeded with 2.5x10(5) cells/scaffold. Two control and 2 aB treated scaffolds were subcutaneously implanted into each of 6 nude mice for 6 weeks. Four observers ranked bone formation using a pair wise comparison of histological sections form each mouse. The aB assay successfully followed cell proliferation, however, the diffusion kinetics of the 3D constructs must be considered. The influence of in vitro aB treatment on subsequent in vivo bone formation cannot be ruled out but was not shown to be significant in the current study. The aB assay appears to be quite promising for evaluating a maximum or end-point viability of 3D tissue engineered constructs. Finally, higher seeding densities resulted in more observed bone formation.

Cree infant care practices and sudden infant death syndrome.

OBJECTIVE: To identify contemporary Cree infant care practices and any risk factors associated with Sudden Infant Death Syndrome. METHODS: A questionnaire conducted and recorded in the homes of 70 Cree women (83% of sample available) with infants under 12 months of age, living full time on a Cree reserve. Participatory observation was also used with mothers who agreed to demonstrate certain features of Cree infant care. FINDINGS: 70% of mothers initiated breast-feeding and 43% nursed from 6 to 15 months. Cree infants are tightly swaddled and placed in a supine position for sleeping. Prenatal care is seldom utilized because of cultural beliefs that planning ahead constitutes bad luck during birth or results in deformed infants. CONCLUSIONS: Existing infant care practices include several that are considered protective to an infant in terms of reducing vulnerability to SIDS. Swaddling infants in very warm houses and smoking during pregnancy could contribute to a higher SIDS incidence.

Sudden infant death syndrome and Canadian Aboriginals: bacteria and infections.

Aboriginal populations in Canada, America and Australia have higher incidences of sudden infant death syndrome (SIDS) than non-Aboriginal groups. Canadian Aboriginal populations (known also as first nation, native or Indian) experience infant morbidity/mortality rates 3-7 times that of non-Aboriginals, with upper track respiratory infection and SIDS recorded as the leading causes. The aim of this investigation was to examine the home environment of Aboriginal infants, particularly during winter months when respiratory tract infections and SIDS are more common. Environmental bacteria, fungi and air particulates were examined in the residences of Aboriginal infants during visits to individual homes on an Aboriginal reserve. The physical histories of SIDS victims were gathered from medical files. Air and surfaces were sampled by agar strips which were processed by a commercial laboratory. The levels of fungi, bacteria and air particulate rates recorded in the reserve homes of Aboriginal infants registered levels considered to be detrimental to the health of the inhabitants. Such extreme levels could contribute to the high incidence of respiratory disease and SIDS experienced by Canadian Aboriginal infants.

Evidence of GnRH receptors in cultured pituitary cells of the winter flounder (Pseudopleuronectes americanus W.).

For continued studies of GnRH receptor regulation in the winter flounder, we have developed an in vitro system consisting of cultured pituitary cells dissociated by collagenase. Using immunocytochemical staining methods for gonadotropin, growth hormone, and prolactin, these cell types were represented at the levels of 25, 20, and 19.5% of total pituitary cell population, respectively. Receptors for GnRH were characterized in intact monolayered attached pituitary cells, maintained in RPMI culture medium. The cell GnRH receptor characteristics were compared with those previously described using pituitary homogenates. The cells were capable of binding GnRH in a similar manner on Day 2 or Day 3 of culture, indicating the integrity of GnRH receptors. The specificity of binding was demonstrated since only high doses of cold GnRHa competed with 125I-GnRHa uptake, different peptides being without effect. The specific binding is saturable and the data suggest the presence of a single class of high-affinity (apparent Ka = 1.50 x 10(9) M-1), high-capacity sites (binding capacity = 25.03 fmol/2.5 x 10(5) cells or 242.23 x 10(3) sites/gonadotroph) which is in accordance with the characteristics of GnRH receptors present in homogenates of pooled male and female pituitary glands. All these observations suggest that such an in vitro pituitary cell system would be appropriate for studying GnRH receptor characteristics under different physiological conditions.

Hearing-damage risk and communication interference in dental practice.

The use of high-speed air-turbine handpieces, operated at 300,000 to 400,000 revolutions per minute, has led to concern over the possibility of noise-induced hearing loss. Sound levels were measured in clinical settings and in a pre-clinical laboratory for estimation of hearing-damage risk among dentists, and the extent of communication interference. Octave-band sound pressure levels were obtained with use of a Fast-Fourier-Transform analyzer and associated instrumentation. The results of this study indicate that the sound energy contribution of a typical dental practice is about 8% to 12% of the dentist's average 24-hour noise exposure. However, noise levels during dental procedures result in an articulation index of 0.21 to 0.37, corresponding to understanding of about 18% to 48% of nonsense syllables and 52% to 90% of sentences. It appears that hearing-damage risk is slight among dentists using modern equipment. However, further noise control in handpieces is necessary so that error-free communication during dental procedures can be ensured.

Private long-term care insurance: after coverage restrictions is there anything left?

Private long-term care insurance has been suggested as a solution to the crushing burden of out-of-pocket expenditures for nursing home and home health care. This paper examines the effects of common policy restrictions among currently marketed policies, more than a million of which have been sold. Using a conditional probabilities model and data from the 1985 National Nursing Home Survey (NNHS), we estimate likelihood of policy compliance for 31 combinations of policy restrictions. Compliance estimates range from 8.5% to 91.9%. Results indicate that prior hospitalization and prior skilled care clauses represent significant stumbling blocks for policyholders seeking benefit payments.

Studies of the biological activity of LHRH analogs in the rainbow trout, landlocked salmon, and the winter flounder.

Studies of gonadotropic hormone (GtH) release bioactivity by mammalian and submammalian varieties of LHRH and LHRH analog were primarily conducted in vivo in testosterone-primed yearling (TPY) rainbow trout, a convenient test animal for LHRH bioassays in fish. Validation of these results, using sexually mature fish, was accomplished by examining LHRH agonist activities on release of GtH in vivo in spermiating landlocked salmon and by studying LHRH peptide hormone binding affinities using a flounder pituitary LHRH radioreceptor assay. Our surveys of LHRH analog bioactivity in vivo in TPY trout and salmon demonstrated that all types of fish, bird, and mammalian LHRH agonists possess superactive properties on the fish pituitary. The most active group of LHRH analogs, based upon both LHRH receptor binding affinity and in vivo release of gonadotropin, was judged to include [D-Nal(2)6,Pro9-NHEt]LHRH, [D-Nal(2)6-AzaGly10]LHRH, [D-Ala6,Pro9-NHEt]-LHRH, and the fish LHRH analogs, [D-Arg6,Trp7,Leu8,Pro9-NHEt]LHRH, [D-hArg(Et2(6),Trp7,Leu8,Pro9-NHEt]LHRH.

X-ray calcifications as the only basis for breast biopsy.

Two hundred fifty-one consecutive patients were treated between 1964 and 1982 with mammographic calcifications as the only reason for breast biopsy. Patients with either clinical or x-ray findings other than calcifications were excluded. A correlation of the x-ray, pathology, and clinical experience is the basis of this report. Specimen radiography with paraffin section histology (i.e., no frozen section) was performed on all biopsy material. The procedure of specimen radiography that was utilized is described. A team approach involving radiologists, pathologists, and surgeons has been essential both to confirm excision of the calcifications and localize them for pathology study. Carcinoma was found in 45 patients (17%). A retrospective study of the calcifications was also undertaken to determine characteristics that would permit definitive radiographic diagnosis of benign or malignant disease.

Uterus didelphys with unilateral imperforate vagina: spontaneous rupture of the vaginal septum.

A 13-year-old girl with abnormal vaginal bleeding was found to have uterus didelphys with unilateral imperforate vagina. A brief discussion of this rare anomaly and its treatment accompanies the case report.