In vitro bioactivity evaluation of titanium and niobium metals with different surface morphologies.

Current orthopaedic biomaterials research mainly focuses on designing implants that could induce controlled, guided and rapid healing. In the present study, the surface morphologies of titanium (Ti) and niobium (Nb) metals were tailored to form nanoporous, nanoplate and nanofibre-like structures through adjustment of the temperature in the alkali-heat treatment. The in vitro bioactivity of these structures was then evaluated by soaking the treated samples in simulated body fluid (SBF). It was found that the morphology of the modified surface significantly influenced the apatite-inducing ability. The Ti surface with a nanofibre-like structure showed better apatite-inducing ability than the nanoporous or nanoplate surface structures. A thick dense apatite layer formed on the Ti surface with nanofibre-like structure after 1 week of soaking in SBF. It is expected that the nanofibre-like surface could achieve good apatite formation in vivo and subsequently enhance osteoblast cell adhesion and bone formation.

Atom probe tomography data analysis procedure for precipitate and cluster identification in a Ti-Mo steel.

An atom probe tomography data analysis procedure for identification of particles in a Ti-Mo steel is presented. This procedure has been used to characterise both carbide precipitates (larger particles) and solute clusters (smaller particles), as reported in an accompanying Mater. Sci. Eng. A paper [1]. Particles were identified using the maximum separation method (cluster-finding algorithm) after resolving peak overlaps at several locations in the mass spectrum. The cluster-finding algorithm was applied to the data in a two-stage process to properly identify particles having a bimodal size distribution. Furthermore, possible misidentification of matrix atoms (mainly Fe) due to the local magnification effect (from the difference in field evaporation potential between the matrix and precipitates) has been resolved using an atomic density approach, comparing that measured experimentally using APT to the theoretical density of both the matrix and particles.

Hydroxyapatite/titania sol-gel coatings on titanium-zirconium alloy for biomedical applications.

A simple sol-gel method was developed for hydroxyapatite/titania (HA/TiO(2)) coatings on non-toxic titanium-zirconium (TiZr) alloy for biomedical applications. The HA/TiO(2)-coated TiZr alloy displayed excellent bioactivity when soaked in a simulated body fluid (SBF) for an appropriate period. Differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy-energy dispersive spectrometry were used to characterize the phase transformations and the surface structures and to assess the in vitro tests. The HA/TiO(2) layers were spin-coated on the surface of TiZr alloy at a speed of 3000rpm for 15s, followed by a heat treatment at 600 degrees C for 20min in an argon atmosphere sequentially. The TiO(2) layer exhibited a cracked surface and an anatase structure and the HA layer displayed a uniform dense structure. Both the TiO(2) and HA layers were 25microm thick, and the total thickness of the HA/TiO(2) coatings was 50microm. The TiZr alloy after the above HA/TiO(2) coatings displayed excellent bone-like apatite-forming ability when soaked in SBF and can be anticipated to be a promising load-bearing implant material.

Exposing the impact of Citizens Advice Bureau services on health: a realist evaluation protocol.

INTRODUCTION: Welfare advice services can be used to address health inequalities, for example, through Citizens Advice Bureau (CAB). Recent reviews highlight evidence for the impact of advice services in improving people's financial position and improving mental health and well-being, daily living and social relationships. There is also some evidence for the impact of advice services in increasing accessibility of health services, and reducing general practitioner appointments and prescriptions. However, direct evidence for the impact of advice services on lifestyle behaviour and physical health is currently much less well established. There is a need for greater empirical testing of theories around the specific mechanisms through which advice services and associated financial or non-financial benefits may generate health improvements. METHODS AND ANALYSIS: A realist evaluation will be conducted, operationalised in 5 phases: building the explanatory framework; refining the explanatory framework; testing the explanatory framework through empirical data (mixed methods); development of a bespoke data recording template to capture longer term impact; and verification of findings with a range of CAB services. This research will therefore aim to build, refine and test an explanatory framework about how CAB services can be optimally implemented to achieve health improvement. ETHICS AND DISSEMINATION: The study was approved by the ethics committee at Northumbria University, UK. Project-related ethical issues are described and quality control aspects of the study are considered. A stakeholder mapping exercise will inform the dissemination of results in order to ensure all relevant institutions and organisations are targeted.

Anodization parameters influencing the morphology and electrical properties of TiO2 nanotubes for living cell interfacing and investigations.

Nanotube structures have attracted tremendous attention in recent years in many applications. Among such nanotube structures, titania nanotubes (TiO2) have received paramount attention in the medical domain due to their unique properties, represented by high corrosion resistance, good mechanical properties, high specific surface area, as well as great cell proliferation, adhesion and mineralization. Although lot of research has been reported in developing optimized titanium nanotube structures for different medical applications, however there is a lack of unified literature source that could provide information about the key parameters and experimental conditions required to develop such optimized structure. This paper addresses this gap, by focussing on the fabrication of TiO2 nanotubes through anodization process on both pure titanium and titanium alloys substrates to exploit the biocompatibility and electrical conductivity aspects, critical factors for many medical applications from implants to in-vivo and in-vitro living cell studies. It is shown that the morphology of TiO2 directly impacts the biocompatibility aspects of the titanium in terms of cell proliferation, adhesion and mineralization. Similarly, TiO2 nanotube wall thickness of 30-40nm has shown to exhibit improved electrical behaviour, a critical factor in brain mapping and behaviour investigations if such nanotubes are employed as micro-nano-electrodes.

Molecular cloning of troponin I expressed in fast white muscle of a teleost fish, the Atlantic herring (Clupea harengus L.).

By cDNA cloning and 5'-RACE analysis we characterised a Clupea harengus troponin I mRNA expressed in larvae and in adult white (fast) muscle, but not in red (slow) or cardiac muscle. The mRNA encodes a TnI protein of the short chain length (176 residues) N-terminally truncated type previously observed only in tetrapod skeletal muscles. Despite its expression specificity the herring TnI does not particularly resemble the tetrapod fast skeletal muscle isoform in sequence but appears to be outside of the tetrapod TnIfast/Tnslow/TnIcardiac isoform family. Surprisingly, the actin/TnC-binding sequence resembles that of arthropod, rather than tetrapod vertebrate, troponin I's and has, besides, unique features not seen in any other troponin I's, vertebrate or invertebrate.

ADL 8-2698, a trans-3,4-dimethyl-4-(3-hydroxyphenyl) piperidine, prevents gastrointestinal effects of intravenous morphine without affecting analgesia.

ADL-8-2698 is a novel peripherally restricted opioid antagonist that may selectively prevent opioid-induced gastrointestinal effects without reversing analgesia. Gastrointestinal transit time (lactulose hydrogen breath test) was measured in 14 volunteers with oral and intravenous placebo, oral placebo and intravenous morphine (0.05 mg x kg(-1)), and oral ADL 8-2698 (4 mg) and intravenous morphine (0.05 mg x kg(-1)) in a double blind, cross-over study. Morphine prolonged gastrointestinal transit time from 69 to 103 minutes (P = .005); this was prevented by ADL 8-2698 (P = .004). Postoperatively, 45 patients were randomly assigned in a double-blind fashion to receive ADL 8-2698 (4 mg) or placebo and intravenous morphine (0.15 mg/kg) or to receive oral and intravenous placebo. Analgesia and pupil constriction were measured. Morphine analgesia and pupil constriction were unaffected by ADL 8-2698 and differed from placebo (P < .002). We conclude that ADL 8-2698 prevents morphine-induced increases in gastrointestinal transit time by means of selective peripheral opioid anitagonism without affecting central opioid analgesia.

Nutrient intake and serum cholesterol level in normal children 6 to 16 years of age.

A study of 103 healthy, white schoolchildren who were between 6 and 16 years of age revealed no positive correlation between the level of serum cholesterol and the mean daily amount of total calories, cholesterol, fat, saturated fat, or sugar in the diet.

The geographic distribution and host range of Capillaria hepatica (Bancroft) (Nematoda) in Australia.

The geographic distribution, host range and prevalence of Capillaria hepatica were recorded in 4629 house mice, Mus domesticus, 263 black rats, Rattus rattus, and 58 Norway rats, R. norvegicus. The parasite was found at five localities, all in or near large towns along the coast. The two Rattus species appeared to be the primary hosts of C. hepatica in Australia. Published and unpublished data on helminth infections of Australian native mammals from 1162 murids (26 species), 3018 marsupials (67 species) and 99 monotremes (two species) were compiled. Only seven animals from three murid species were infected with C. hepatica; all were from the same rainforest in northern Queensland. C. hepatica was distributed widely, occurring in the house mouse, black rat and Norway rat on a 10,850 ha farm but there was no infection in cattle, sheep or goats (abattoir records). Also, 52 rabbits, four cats and one fox (shot samples) and 27 marsupial mice, Sminthopsis crassicaudata (museum specimens), had no sign of C. hepatica infection. Overall, the results indicate that transmission of C. hepatica to native, domestic and feral mammals is rare, presumably because of ecological constraints on egg embryonation and survival. In the light of these findings, the potential use of C. hepatica as a biological agent to control mouse plagues in Australia is discussed.

Cholesterol and triglycerides in serum lipoproteins of young persons in Rochester, Minnesota.

Cholesterol and triglyceride levels in whole sera and in the major lipoprotein fractions are presented for 2,421 children and youths in Rochester, Minnesota, ranging in age from 6 to 18 years. This cross-sectional study revealed subtle changes associated with puberty and the occurrence of certain additional sex-specific changes related to age. Hyperlipoproteinemia was detected in 101 youngsters; those cases exemplified types IIa (61 cases), IIb (5 cases), III (5 cases), and IV (30 cases). One case of type V hyperlipoproteinemia was observed in a second and comparable population sample of 1,245 young persons.

Comparison of serum cholesterol in children fed high, moderate, or low cholesterol milk diets during neonatal period.

The long-term effects of milk diets in infancy on the blood serum cholesterol concentrations were studied in 97 school children 7-12 yr of age. Detailed histories were available for these children with respect to their diets during infancy. The major criterion for inclusion in the study was milk (human milk, cow's milk, or commercial formula) as the exclusive source of diet cholesterol during the first 3 mo of life. Fasting blood cholesterol and triglycerides were measured in these 97 school children, and the current diets of 29 of the 97 were evaluated for daily cholesterol intake. A 7-day diet diary was recorded, the food intake was measured and analyzed for nutrients, and validity of the diets was verified by determination of urinary nitrogen excretion. Results of the study showed that the school children fed a low cholesterol formula during infancy had a mean serum cholesterol value 7-12 yr later that was lower than the mean values of the groups fed greater amounts of cholesterol in infancy. Analysis of current diets of 29 of the 97 school children showed that their current dietary intake of cholesterol was low. Dietary intake of cholesterol did not have a noticeable effect on the serum cholesterol levels of the 29 children.

Maturation of porcine tracheal cholinergic and inhibitory non-adrenergic, non-cholinergic innervation.

It is known that both excitatory cholinergic neural activity and nitric oxide (NO) release from inhibitory non-adrenergic, non-cholinergic (iNANC) nerves are important determinants of adult human airway smooth muscle tone. However, the level of cholinergic and iNANC activity in the newborn is unknown. Therefore, isolated trachealis muscle strips were obtained from neonatal, 10-day-old, and adult pigs. To quantify cholinergic nerve activity, isometric contractions were elicited by stimulating the nicotinic receptors of the cholinergic intramural ganglia with dimethyl-phenyl-piperazinium (DMPP). After ganglionic blockade with hexamethonium, the post-ganglionic cholinergic nerves were subjected to electrical field stimulation (EFS). To assess whether DMPP and EFS were also stimulating nitric oxide release from iNANC nerves, the stimulations were repeated after NO-synthase inhibition with 3 x 10(-5) M NG-monomethyl-L-arginine acetate (LNMMA). All responses were expressed as a percentage of maximal response to 10(-4) M acetylcholine. Although no significant age-related differences in the contractile responses to DMPP were demonstrated between the three age groups, the EFS responses were significantly different. At EFS frequencies of 1 and 2 Hz the responses of all three groups were different (P < 0.05, unpaired t-test). At frequencies of 0.125 and 0.5 Hz the contractile responses in the neonatal and 10-day-old groups were less than in the adult animal tissues (P < 0.05, unpaired t-test). At 4 Hz and above, the responses of the 10-day-old and adult groups became greater than the neonatal (P < 0.05, unpaired t-test). LNMMA did not significantly increase the contractile responses to DMPP at any age. Only in the neonatal rat and 10-day-old groups was a significant increase of the EFS frequency responses by LNMMA demonstrated (140.4 +/- 38.2% and 144.2 +/- 41.2%, respectively, at 0.5 Hz, ANOVA, P < 0.001). In conclusion, the DMPP responses suggest that the neonatal porcine cholinergic innervation is mature at birth. This contrasts with a frequency-dependent increase in EFS responses from birth. This may be due in part to a relative increase in iNANC modulation of post-ganglionic cholinergic activity at birth. This mechanism is not responsible for the increase in higher EFS frequency responses with post-natal maturation. Inhibitory iNANC activity may serve a protective role in the newborn, given the reported hyper-responsiveness of airway smooth muscle, small airway caliber, and high chest wall compliance at this age.

Operative management of incidental cholelithiasis.

Incidental cholelithiasis was encountered at the time of celiotomy in 56 patients. Thirty-three of the patients underwent concomitant cholecystectomy. The overall morbidity and mortality were 27 and 3 percent, respectively, but only one complication (3 percent) was clearly related to the cholecystectomy. Cholecystectomy was not performed in 23 patients. Within 6 months of primary celiotomy, acute cholecystitis developed in 11 patients, 3 had attacks of biliary colic, and 2 became jaundiced. Fifteen patients (65 percent) underwent cholecystectomy and 6 of the 15 (40 percent) required common bile duct exploration. Concomitant cholecystectomy adds minimal morbidity to the operation and should be performed unless specific contraindications exist. Left untreated, cholelithiasis becomes symptomatic and leads to subsequent operation in most patients, which may require a more extensive procedure producing greater morbidity.

The many uses of the U tube.

U tube placement was employed as an adjunct to complicated biliary procedures in 14 patients. We found the transhepatic tubes to be useful for stenting biliary anastomoses, maintaining biliary drainage, delivering localized irradiation, and acting as permanent external conduits. The tubes remained in placed an average of 15 months and as long as 40 months. The frequency of cholangitis was minimized by frequent tube exchange. The U-shaped configuration makes tube exchange easy and inexpensive to perform.

Increased incidence of pancreas-related complications in patients with postoperative pancreatitis.

The incidence and significance of pancreas-related complications (pseudocysts, abscesses, and fistulas) were evaluated in 100 patients with acute pancreatitis. Alcoholic (40 percent), biliary (20 percent), and postoperative (15 percent) pancreatitis were seen most frequently. Eighteen patients had severe pancreatitis (3 or more Ranson's criteria). The overall mortality rate was 8 percent, and there were 16 pancreas-related complications. Pancreas-related complications developed in eight patients (53 percent), including two pseudocysts, four abscesses, and two fistulas. The incidence of pancreas-related complications was significantly greater in the postoperative group than in the overall 9 percent incidence in the other groups (p less than 0.005). Half of these patients required operation for their complications. Patients with postoperative pancreatitis are at a markedly increased risk of pancreas-related complications. Since these complications occur even in apparently mild cases of pancreatitis, these patients should be followed closely to detect pancreas-related complications.

Value of pneumoperitoneum in the diagnosis of visceral perforation.

The presence or absence of pneumoperitoneum may not be as reliable an indicator of visceral perforation as commonly thought. Visceral perforation as commonly thought. Visceral perforation resulted in pneumoperitoneum in only 51 percent of patients in this study. Pneumoperitoneum occurred in 14 percent of patients in whom the extraalimentary intraperitoneal air had sources other than a perforated viscus. These patients' clinical findings were often indistinguishable from those of patients with a perforated viscus, and three patients underwent celiotomy unnecessarily. The routine use of the left lateral decubitus film to detect pneumoperitoneum and the judicious use of gastrointestinal contrast studies should be part of the optimal management of patients with suspected visceral perforation.

The many faces of food--as seen through the eyes of the artist.

Artists through the ages have displayed an interest in food, not only for its nourishing value but also for its aesthetic nature. Consequently, the art world has endowed the field of nutrition with a colorful record of the artistic merits and heritage of food. In this article, the author explores some of the food lore depicted in various famous paintings. Such insights should be rewarding to anyone who enjoys pictorial art as an avocation--and especially to those whose vocation involves food. As knowledge of food and eating customs increases, so also does the appreciation for the theme of a painting, the intent of the artist, and the culture that nourished both his palate and palette.

Glucose determination by a pulsed photoacoustic technique: an experimental study using a gelatin-based tissue phantom.

A preliminary study of using a gelatin-based in vivo tissue model to investigate some of the near infrared photoacoustic characteristics that may influence the sensitivity of non-invasive photoacoustic detection of blood glucose in human tissue is described. It is shown that the optical absorption change due to glucose in the near infrared region is small and that the pulsed photoacoustic technique may offer a better detection sensitivity than other conventional optical transmission measurement systems being developed for blood glucose monitoring.

Hepatic fibrosis and cytochrome P450: experimental models of fibrosis compared to AHR knockout mice.

Hepatic fibrosis is characterized by abnormal collagen deposition resulting from increased collagen synthesis and decreased collagen degradation. Cytochrome P450 mediates major drug metabolizing enzyme activity in the liver and this activity is reduced in hepatic fibrosis. In this study we assess cytochrome P450 and CYP 1A mRNA in livers of animals that have been induced to hepatic fibrosis using the heterologous serum induced model of fibrosis in rats compared to controls. Fibrosis was confirmed by assessing the collagen in liver sections as quantified by Sirius red/Fast green staining, a quantitative measure of fibrosis as well as by visualization of the hepatic fibrosis. Collagen levels in the liver sections of heterologous serum induced fibrotic rats was increased by 33% compared to controls and a typical fibrotic pattern was seen. Messenger RNA was prepared from heterologous serum induced fibrotic rats and compared to controls. CYP 1A2 was assessed using a specific probe and the CYP 1A2 level was significantly reduced in the heterologous serum induced fibrotic rats compared to controls. These results further suggest that cytochrome P450 is reduced in the presence of hepatic fibrosis. Thus, in three well established experimental models of hepatic fibrosis which had clearly developed hepatic fibrosis (as shown by Sirius red/Fast green staining), cytochrome P450 mediated enzyme activity, or specifically, CYP 1A messenger RNA is decreased. We then investigated a transgenic mouse, deficient in the arylhydrocarbon hydroxylase receptor (AHR), which has undetectable levels of CYP 1A messenger RNA. We quantitated the collagen in liver sections obtained from AHR knockout mice compared to controls, as an indication of the presence of hepatic fibrosis. Collagen concentration was significantly increased by 53% (P<0.0005) in sections from Ahr-/- (knockout) mice compared to wild-type controls. Collagen in livers of the Ahr+/- heterozygous mice was not different from wild-type controls. The increase in collagen concentration in liver sections is an indication of fibrosis in Ahr-/- mice. Collagen protein deposition was also elevated in liver sections from bile duct ligated rats (by 44%) compared to sham operated controls, was elevated in liver sections from heterologous serum induced fibrosis in rats (33%) compared to controls, and was elevated in liver sections from yellow phosphorous induced hepatic fibrosis (74%) compared to vehicle treated controls. In conclusion, these results indicate that cytochrome P450 and specific subtypes of P450, the CYP 1A subgroup, are significantly reduced in three experimental models of hepatic fibrosis when there is evidence of increased collagen deposition in the livers. These results also indicate that mice that are deficient in CYP 1A have elevated levels of hepatic collagen protein, an indication of hepatic fibrosis.

Analogs of cell surface carbohydrates. Synthesis of D-galactose derivatives having an ethynyl, vinyl or epoxy residue at C-5.

Compounds derived from D-galactose having an ethynyl, vinyl, or epoxide residue at C-5, as well as 7,7-dibromo olefinic, isomeric 7,7-gem-bromofluoro olefinic, and 6,6-gem-difluoro derivatives were obtained from 1,2:3,4-di-O-iso-propylidene-alpha-D-galacto-hexodialdo-1,5- pyranose.