A scoping review of graphene-based biomaterials for in vivo bone tissue engineering.

The growing demand for more efficient materials for medical applications brought together two previously distinct fields: medicine and engineering. Regenerative medicine has evolved with the engineering contributions to improve materials and devices for medical use. In this regard, graphene is one of the most promising materials for bone tissue engineering and its potential for bone repair has been studied by several research groups. The aim of this study is to conduct a scoping review including articles published in the last 12 years (from 2010 to 2022) that have used graphene and its derivatives (graphene oxide and reduced graphene) in preclinical studies for bone tissue regeneration, searching in PubMed/MEDLINE, Embase, Web of Science, Cochrane Central, and clinicaltrials.gov (to confirm no study has started with clinical trial). Boolean searches were performed using the defined key words "bone" and "graphene", and manuscript abstracts were uploaded to Rayyan, a web-tool for systematic and scoping reviews. This scoping review was conducted based on Joanna Briggs Institute Manual for Scoping Reviews and the report follows the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Extension for Scoping Reviews (PRISMA-ScR) statement. After the search protocol and application of the inclusion criteria, 77 studies were selected and evaluated by five blinded researchers. Most of the selected studies used composite materials associated with graphene and its derivatives to natural and synthetic polymers, bioglass, and others. Although a variety of graphene materials were analyzed in these studies, they all concluded that graphene, its derivatives, and its composites improve bone repair processes by increasing osteoconductivity, osteoinductivity, new bone formation, and angiogenesis. Thus, this systematic review opens up new opportunities for the development of novel strategies for bone tissue engineering with graphene.

Dental intervention prior to and subsequent to the diagnosis of acute myeloid leukemia: case report / Intervenção odontológica prévia e subsequente ao diagnóstico de leucemia mielóide aguda: relato de caso

ABSTRACT Leukemia's are characterized by the proliferation of immature white blood cells, called blasts, in the bone marrow and / or blood. Among them, we highlight the Monocytic Acute Myeloid Leukemia, which represents a malignant neoplasm whose unnatural monoblast proliferation results in suppression of myeloid series cells. Oral manifestations are common, arising at the onset of the disease and are also associated with chemotherapy during treatment leading to complications that compromise oncotherapy. The present study deals with a patient with this type of aggressive leukemia, with oral complications of the disease and later, oncological treatment. It also give prominence the performance of the dental surgeon in distinct phases of the treatment emphasizing the importance of maintaining oral health in cancer patients. The presence of the Dentist in the multi-professional team contributes to the reduction of manifestations that occur both due to the disease and the treatment, ensuring a better quality of life for cancer patients and avoiding higher expenses to the health system.

RESUMO As leucemias são caracterizadas pela proliferação de células imaturas da linhagem branca, denominadas blastos, na medula óssea e/ou sangue. Dentre elas destacamos a Leucemia Mielóide Aguda Monocítica, que representa uma neoplasia maligna, cuja proliferação anormal de monoblastos resulta na supressão das células da série mielóide. Manifestações orais são comuns, surgindo no início da doença e também associadas à quimioterapia durante o tratamento gerando complicações que comprometem a oncoterapia. O presente trabalho trata-se de um paciente portador deste tipo agressivo de leucemia, com complicações bucais da doença e posteriormente, do tratamento oncológico. Destaca ainda a atuação do cirurgião-dentista em fases distintas do tratamento realçando a importância da manutenção da saúde bucal em pacientes oncológicos. A presença do Cirurgião-Dentista na equipe multiprofissional contribui para diminuição das manifestações que ocorrem tanto devido à doença quanto ao tratamento, garantindo melhor qualidade de vida do paciente oncológico e evitando maiores gastos ao sistema de saúde.

Optical and Electrochemical Applications of Li-Doped NiO Nanostructures Synthesized via Facile Microwave Technique.

Nanostructured NiO and Li-ion doped NiO have been synthesized via a facile microwave technique and simulated using the first principle method. The effects of microwaves on the morphology of the nanostructures have been studied by Field Emission Spectroscopy. X-ray diffraction studies confirm the nanosize of the particles and favoured orientations along the (111), (200) and (220) planes revealing the cubic structure. The optical band gap decreases from 3.3 eV (pure NiO) to 3.17 eV (NiO doped with 1% Li). Further, computational simulations have been performed to understand the optical behaviour of the synthesized nanoparticles. The optical properties of the doped materials exhibit violet, blue and green emissions, as evaluated using photoluminescence (PL) spectroscopy. In the presence of Li-ions, NiO nanoparticles exhibit enhanced electrical capacities and better cyclability. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results show that with 1% Li as dopant, there is a marked improvement in the reversibility and the conductance value of NiO. The results are encouraging as the synthesized nanoparticles stand a better chance of being used as an active material for electrochromic, electro-optic and supercapacitor applications.

Abstracts of the 24th international isotope society (UK group) symposium: synthesis and applications of labelled compounds 2015.

The 24th annual symposium of the International Isotope Society's United Kingdom Group took place at the Møller Centre, Churchill College, Cambridge, UK on Friday 6th November 2015. The meeting was attended by 77 delegates from academia and industry, the life sciences, chemical, radiochemical and scientific instrument suppliers. Delegates were welcomed by Dr Ken Lawrie (GlaxoSmithKline, UK, chair of the IIS UK group). The subsequent scientific programme consisted of oral presentations, short 'flash' presentations in association with particular posters and poster presentations. The scientific areas covered included isotopic synthesis, regulatory issues, applications of labelled compounds in imaging, isotopic separation and novel chemistry with potential implications for isotopic synthesis. Both short-lived and long-lived isotopes were represented, as were stable isotopes. The symposium was divided into a morning session chaired by Dr Rebekka Hueting (University of Oxford, UK) and afternoon sessions chaired by Dr Sofia Pascu (University of Bath, UK) and by Dr Alan Dowling (Syngenta, UK). The UK meeting concluded with remarks from Dr Ken Lawrie (GlaxoSmithKline, UK).

[Aseptic acetabular necrosis with recurrent luxation of a bipolar hemiarthroplasty into the retroperitoneum]. / Aseptische Azetabulumnekrose mit rezidivierender Luxation eines Duokopfs in das Retroperitoneum.

In comparison to aseptic osteonecrosis of the femoral head, the occurrence of aseptic acetabular osteonecrosis is extremely rare. This article reports the case of a 77-year-old woman with a large defect of the posterior acetabular wall (type 3 AAOS/D'Antonio score). We present an option for treatment in cases of a combination of osteonecrosis with implanted bipolar hemiarthroplasty.

[Nickel allergy and painful unicondylar knee arthroplasty]. / Nickelallergie und schmerzhafte monokondyläre Kniegelenksschlittenprothese.

A 56-year-old woman with unicondylar knee arthroplasty (Oxford III, Biomet) complained of persistent, burning pain in her knee. The arthroplasty failure was caused by a nickel allergy. The diagnosis was confirmed by positive patch testing, lymphocyte transformation test and histological analysis of the neosynovia around the implant. The unicondylar knee arthroplasty was explanted and replaced by a titanium-coated knee prosthesis (INNEX CR, Zimmer).

Disposition and metabolism of the colchicine derivative [14C]-ZD6126 in rat and dog.

1. The tissue distribution, disposition and metabolism of ZD6126, a novel vascular targeting agent, were investigated in rat and dog. This paper comprises the findings of several investigations, including rat quantitative whole-body autoradiography (QWBA), rat and dog balance and metabolism (both in intact and bile-duct-cannulated animals), rat enterohepatic recirculation, and comparison of metabolism between young and mature rats. 2. Following intravenous administration of [(14)C]-ZD6126 to rats, quantitative whole-body autoradiography showed that radioactivity was widely distributed, then rapidly eliminated from the body. 3. ZD6126-related material was eliminated primarily in the faeces (approximately 86%) of both species, indicating the importance of biliary clearance. 4. Metabolite profiles from intact and bile-duct-cannulated animals suggest that ZD6126 is cleared primarily by metabolism. In rat, the major metabolites were ZD6126 phenol, its glucuronide and other metabolites consistent with O-demethylation and conjugation. ZD6126 was more extensively metabolized by male than female rats, and also in young compared with mature rats. In dog, metabolism occurred primarily via direct glucuronidation of the active species, ZD6126 phenol. 5. Following intraduodenal infusion of bile containing [(14)C]-ZD6126-related material to bile-duct-cannulated rats, 30% of the radioactivity was subsequently recovered in bile and urine, showing that one or more components in bile are reabsorbed and undergo enterohepatic recirculation.

In vitro metabolism of a triclyclic alkaloid (M445526) in human liver microsomes and hepatocytes.

The in vitro metabolism of M445,526 (ZD6,126 phenol) was investigated by incubating [(14)C]-M445,526 at a concentration of 10 microg ml(-1) with human hepatic microsomes (4 mg ml(-1)) or human hepatocytes (2 x 10(6) cells ml(-1)) for up to 180 min. Following incubation with microsomes and hepatocytes, up to 78% and 40% of [(14)C]-M445,526 was metabolized after 180 and 120 min, respectively. High-performance liquid chromatography (HPLC) with radiochemical detection confirmed extensive metabolism of [(14)C]-M445,526 by microsomes and hepatocytes. Mass spectrometry and (1)H-NMR spectroscopy enabled structural identification of up to eight metabolites. Human liver microsomes formed one major (O-desmethyl) and three minor (a further O-desmethyl and two different hydroxylated) phase I metabolites. Human hepatocytes produced one major metabolite, a sulphate conjugate of the major O-desmethyl metabolite formed by microsomes. Four minor metabolites were also formed, primarily by O-demethylation with subsequent glucuronidation. Taken collectively, [(14)C]-M445,526 underwent extensive in vitro metabolism by human liver fractions. These data were confirmed by subsequent human in vivo studies.

The application of microbore UPLC/oa-TOF-MS and 1H NMR spectroscopy to the metabonomic analysis of rat urine following the intravenous administration of pravastatin.

The metabonomic effects of hepatotoxic doses of pravastatin on the urinary metabolic profiles of female rats have been investigated using ultra performance liquid chromatography (UPLC)-oa-TOF-MS and, independently, by (1)H NMR spectroscopy. UPLC was performed using a 1 mm microbore column packed with 1.7 microm particles. Examination of the data obtained from the individual animals, aided by statistical interpretation of the data, made it possible to identify potential markers for toxicological effects, with both NMR and UPLC-MS analysis highlighting distinct changes in the urinary metabolite profiles. These markers, which included elevated taurine and creatine, as well as bile acids, were consistent with hepatotoxicity in some animals, and this hypothesis was supported by histopathological and clinical chemistry findings. The analytical data from both techniques could be used to define a metabolic "trajectory" as toxicity developed and to provide an explanation for the lack of hepatotoxicity for one of the animals. The two analytical approaches (UPLC-MS and NMR) were found to be complementary whilst the use of a 1mm i.d. x 100 mm column reduced the amount of sample required for analysis to 2 microL, compared with 10 microL for a 2.1mm i.d. x 100 mm column. The 1mm i.d. column also provided increased signal-to-noise without loss of chromatographic efficiency.

HPLC-NMR with severe column overloading: fast-track metabolite identification in urine and bile samples from rat and dog treated with [14C]-ZD6126.

The subject of this study was the determination of the major urinary and biliary metabolites of [(14)C]-ZD6126 following i.v. administration to female and male bile duct cannulated rats at 10 mg/kg and 20 mg/kg, respectively, and male bile duct cannulated dogs at 6 mg/kg by HPLC-NMR spectroscopy. ZD6126 is a phosphorylated pro-drug, which is rapidly hydrolysed to the active metabolite, ZD6126 phenol. The results presented here demonstrate that [(14)C]-ZD6126 phenol is subsequently metabolised extensively by male dogs and both, male and female rats. Recovery of the dose in bile and urine was determined utilising the radiolabel, revealing biliary excretion as the major route of excretion (93%) in dog, with the majority of the radioactivity recovered in both biofluids in the first 6 h. In the rat, greater than 92% recovery was obtained within the first 24 h. The major route of excretion was via the bile 51-93% within the first 12 h. The administered phosphorylated pro-drug was not observed in any of the excreta samples. Metabolite profiles of bile and urine samples were determined by high performance liquid chromatography with radiochemical detection (HPLC-RAD), which revealed a number of radiolabelled components in each of the biofluids. The individual metabolites were subsequently identified by HPLC-NMR spectroscopy and HPLC-MS. In the male dog, the major component in urine and bile was the [(14)C]-ZD6126 phenol glucuronide, which accounted for 3% and 77% of the dose, respectively. [(14)C]-ZD6126 phenol was observed in urine at 1% of dose, but was not observed in bile. A sulphate conjugate of demethylated [(14)C]-ZD6126 phenol was identified in bile by HPLC-NMR and confirmed by HPLC-MS. In the rat, the bile contained two major radiolabelled components. One was identified as the [(14)C]-ZD6126 phenol glucuronide, the other as a glucuronide conjugate of demethylated [(14)C]-ZD6126 phenol. However, a marked difference in the proportions of these two components was observed between male and female rats, either due to a sex difference in metabolism or a difference in dose level. The glucuronide conjugate of the demethylated [(14)C]-ZD6126 phenol was present at higher concentration in the bile of male rats (4-34%), while the phenol glucuronide was present at higher concentration in the bile of female rats (8-70%) over a 0-6 h collection period. A third component was only observed in the bile samples (0-6 h and 6-12 h) of male rats. This was identified as being the same sulphate conjugate of demethylated [(14)C]-ZD6126 phenol as the one observed in dog bile. The rat urines contained two main metabolites in greatly varying concentrations, namely the demethylated [(14)C]-ZD6126 phenol glucuronide and the glucuronide of [(14)C]-ZD6126 phenol. Again, the differences in relative amounts between male and female rats were observed, the major metabolite in the urines from male rats being the demethylated [(14)C]-ZD6126 phenol (0-17% in 0-24 h), whilst the phenol glucuronide, accounting for 0.5-50% of the dose over 0-24 h, was the major metabolite in females. Methanolic extracts of the pooled biofluid samples were submitted for HPLC-NMR for the quick identification of the major metabolites. Following a single injection of the equivalent of 6-28 ml of the biofluids directly onto the HPLC-column with minimal sample preparation, the metabolites could be largely successfully isolated. Despite severe column overloading, the major metabolites of [(14)C]-ZD6126 could be positively identified, and the results are presented in this paper.

A multi-analytical platform approach to the metabonomic analysis of plasma from normal and Zucker (fa/fa) obese rats.

Plasma obtained from 20 week old normal Wistar-derived and Zucker (fa/fa) rats was analysed using a number of different analytical methodologies to obtain global metabolite profiles as part of metabonomic investigations of animal models of diabetes. Samples were analysed without sample pre-treatment using 1H NMR spectroscopy, after acetonitrile solvent protein precipitation by ultra-performance liquid chromatography-MS (UPLC-MS) and after acetonitrile protein precipitation and derivatisation for capillary gas chromatography-MS (GC-MS). Subsequent data analysis using principal components analysis revealed that all three analytical platforms readily detected differences between the plasma metabolite profiles of the two strains of rat. There was only limited overlap between the metabolites detected by the different methodologies and the combination of all three methods of metabolite profiling therefore provided a much more comprehensive profile than would have been provided by their use individually.

The comparative metabonomics of age-related changes in the urinary composition of male Wistar-derived and Zucker (fa/fa) obese rats.

The global metabolite profiles of endogenous compounds excreted in urine by male Wistar-derived and Zucker (fa/fa) obese rats were investigated from 4 to 20 weeks of age using both 1H NMR spectroscopy and HPLC-TOF/MS with electrospray ionisation (ESI). Multivariate data analysis was then performed on the resulting data which showed that the composition of the samples changed with age, enabling age-related metabolic trajectories to be constructed. At 4 weeks it was possible to observe differences between the urinary metabolite profiles from the two strains, with the difference becoming more pronounced over time resulting in a marked divergence in their metabolic trajectories at 8-10 weeks. The changes in metabolite profiles detected using 1H NMR spectroscopy included increased protein and glucose combined with reduced taurine concentrations in the urine of the Zucker animals compared to the Wistar-derived strain. In the case of HPLC-MS a number of ions were found to be present at increased levels in the urine of 20 week old Zucker rats compared to Wistar-derived rats including m/z 71.0204, 111.0054, 115.0019, 133.0167 and 149.0454 (negative ion ESI) and m/z 97.0764 and 162.1147 (positive ion ESI). Conversely, ions m/z 101.026 and 173.085 (negative ion ESI) and m/z 187.144 and 215.103 (positive ion ESI) were present in decreased amounts in urine from Zucker compared to Wistar-derived rats. Metabolite identities proposed for these ions include fumarate, maleate, furoic acid, ribose, suberic acid, carnitine and pyrimidine nucleoside. The utility of applying metabonomics to understanding disease processes and the biological relevance of some of the findings are discussed.

Metabonomics with 1H-NMR spectroscopy and liquid chromatography-mass spectrometry applied to the investigation of metabolic changes caused by gentamicin-induced nephrotoxicity in the rat.

The model nephrotoxin gentamicin was administered to male Wistar-derived rats daily, for 7 days, at 60 mg kg-1 day-1, subcutaneously, twice daily. Conventional clinical chemistry urinalysis showed a significant increase in N-acetyl-beta-D-glucosaminidase (NAG) activity from day 3. At necropsy on day 9, clear histological damage to the kidney was noted with all animals showing a generally severe nephropathy primarily focused on the proximal convoluted tubules. The urinary excretion pattern of endogenous metabolites over the time course of the study was studied using a combination of 1H-NMR spectroscopy and HPLC-TOF-MS/MS using electrospray ionization (ESI). Changes in the pattern of endogenous metabolites as a result of daily administration of gentamicin were readily detected by both techniques with significant perturbations of the urinary profile observed from day 7 onwards. The findings by 1H-NMR included raised glucose and reduced trimethylamine N-oxide (TMAO). Changes in metabonomic profiles were observed by HPLC-MS in both positive and negative ESI. The MS data showed reduced xanthurenic acid and kynurenic acid, whilst neutral loss experiments also revealed a changed pattern of sulphate conjugation on gentamicin administration.

Análise da rejeição nos pacientes transplantados por anemia aplástica severa condicionados com ciclofosfamida ou a associação desta ao bussulfano / Analysis of rejection in transplanted patients suffering severe aplastic anemia conditioned with cyclophosphamide alone or associated with busulfan

O transplante de medula óssea é um tratamento eficaz para pacientes com anemia aplástica severa (AAS) e é a modalidade terapêutica de escolha para pacientes jovens com doador aparentado HLA idêntico. A rejeição é uma importante complicação do transplante de medula, que, independentemente do tipo de tratamento imunossupressor pré e pós-transplante, ocorre em 55 por cento a 60 por cento dos pacientes. O serviço de TMO da Universidade Federal do Paraná (UFPR) acumula a experiência de 178 casos de AAS transplantados no período de 1993 a 2001, usando como condicionamento tanto a ciclofosfamida (CFA) como a combinação desta ao bussulfano (CFA + BU). Dentre eles, 39 apresentaram rejeição ou falha de pega. Dos pacientes condicionados com ciclofosfamida, 24 (46 por cento) apresentaram rejeição, sendo 3 (6 por cento) com falha primária de pega (FPP) e 21 (40 por cento) com pega transitória (PT). Entre os pacientes condicionados com BU+CFA, 15 (12 por cento) apresentaram rejeição, sendo 4 (3 por cento) com FPP e 11 (9 por cento) com pega transitória. Os pacientes condicionados com ciclofosfamida (200 mg/kg) que apresentaram rejeição tiveram uma sobrevida global alta (aproximadamente 80 por cento), pois conseguiram ser resgatados por um novo transplante ou pelo tratamento imunossupressor com ciclosporina. A sobrevida dos pacientes politransfundidos condicionados com a associação de ciclofosfamida e bussulfano foi de aproximadamente 35 por cento.

The metabonomics of aging and development in the rat: an investigation into the effect of age on the profile of endogenous metabolites in the urine of male rats using 1H NMR and HPLC-TOF MS.

The effect of aging and development in male Wistar-derived rats on the profile of endogenous metabolites excreted in the urine was investigated using both (1)H NMR spectroscopy and HPLC-TOF MS using electrospray ionisation (ESI). The endogenous metabolites were profiled in samples collected from male rats every two weeks from just after weaning at 4 weeks up to 20 weeks of age. Multivariate data analysis enabled clusters to be visualised within the data according to age, with urine collected at 4 and 6 weeks showing the greatest differences by both analytical techniques. Markers detected by (1)H NMR spectroscopy included creatinine, taurine, hippurate and resonances associated with amino acids/fatty acids, which increased with age, whilst citrate and resonances resulting from glucose/myoinositol declined. A number of ions were detected by HPLC-MS that were only present in urine samples at 4 weeks of age in both positive and negative ESI, with a range of ions, including e.g. carnitine, increasing with age. Age predictions by PLS-regression modelling demonstrated an age-related trend within these data, between 4 and 12 weeks for HPLC-MS and 4-16 weeks for NMR. The possible utility of these techniques for metabonomic investigations of age-related changes in the rat is discussed and the importance of employing suitable control animals in pharmacological and toxicological studies is highlighted.

[Confronting the practice of surgery on differentiated thyroid cancer with current guidelines in Germany. A multicenter trial]. / Chirurgische Praxis und Leitlinien beim differenzierten Schilddrüsenkarzinom in Deutschland: ein multizentrischer Vergleich.

AIM: For the surgical therapy of differentiated thyroid cancer precise guidelines are applied by the German medical societies. In a retrospective multicenter study, we investigated the following issues: Are the current guidelines respected? Is there a difference concerning the surgical radicalism and the outcome? Does the perioperative morbidity increase with the higher radicalism of the procedure? PATIENTS, METHODS: Data gained from 102 patients from 17 regional referral hospitals who underwent surgery for thyroid cancer and a following rodioiodine treatment (mean follow up: 42.7 [24-79] months) were analyzed. At least 71 criterias were analyzed in a SPSS file. RESULTS: 46.1% of carcinomas were incidentally detected during goiter surgery. The thyroid cancer (papillary n = 78; follicular n = 24) occurred in 87% unilateral and in 13% bilateral. Papillary carcinomas < 1 cm were detected in 25 cases; in five of these cases (20%) contralateral carcinomas < 1 cm were found. There were significant differences concerning the surgical radicalism: a range from hemithyroidectomy to radical thyroidectomy with lateral neck dissection. Analysis of the histopathologic reports revealed that lymph node dissection was not performed according to guidelines in 55% of all patients. The perioperative morbidity was lower in departments with a high case load. The postoperative dysfunction of the recurrent laryngeal nerve (mean: 7.9% total / 4.9% nerves at risk) variated highly, depending on differences in radicalism and hospitals. Up to now these variations in surgical treatment have shown no differences in their outcome and survival rates, when followed by radioiodine therapy. CONCLUSION: Current surgical regimes did not follow the guidelines in more than 50% of all cases. This low acceptance has to be discussed. The actual discussion about principles of treatment regarding, the so-called papillary microcarcinomas (old term) has to be respected within the current guidelines.

D-Serine-induced nephrotoxicity: a HPLC-TOF/MS-based metabonomics approach.

HPLC-MS-based metabonomic analysis was used to investigate urinary metabolic perturbations associated with D-serine-induced nephrotoxicity. D-Serine causes selective necrosis of the proximal straight tubules in the rat kidney accompanied by aminoaciduria, proteinuria and glucosuria. Alderely Park (Wistar-derived) rats were dosed with either D-serine (250 mg/kg ip) or vehicle (deionised water) and urine was collected at 0-12, 12-24, 24-36 and 36-48 h post-dosing. Samples were analysed using a Waters Alliance HT 2795 HPLC system coupled to a Waters Micromass Q-ToF-micro equipped with an electrospray source operating in either positive or negative ion mode. Changes to the urinary profile were detected at all time points compared to control. In negative ion mode, increases were observed in serine (m/z=103.0077), m/z=104.0376 (proposed to be hydroxypyruvate) and glycerate (m/z=105.0215), the latter being metabolites of D-serine. Furthermore, an increase in tryptophan, phenylalanine and lactate and decreases in methylsuccinic acid and sebacic acid were observed. Positive ion analysis revealed a decrease in xanthurenic acid, which has previously been assigned and reported using HPLC-MS following exposure to mercuric chloride and cyclosporine A. A general aminoaciduria, including proline, methionine, leucine, tyrosine and valine was also observed as well as an increase in acetyl carnitine. Investigation of additional metabolites altered as a result of exposure to D-serine is on-going. Thus, HPLC-MS-based metabonomic analysis has provided information concerning the mechanism of D-serine-induced renal injury.

Metabonomics, dietary influences and cultural differences: a 1H NMR-based study of urine samples obtained from healthy British and Swedish subjects.

The aim of this study was to assess the feasibility and comparability of metabonomic data in clinical studies conducted in different countries without dietary restriction. A (1)H NMR-based metabonomic analysis was performed on urine samples obtained from two separate studies, both including male and female subjects. The first was on a group of healthy British subjects (n = 120), whilst the second was on healthy subjects from two European countries (Britain and Sweden, n = 30). The subjects were asked to provide single, early morning urine samples collected on a single occasion. The (1)H NMR spectra obtained for urine samples were visually inspected and analysed chemometrically using principal components analysis (PCA). These inspections highlighted outliers within the urine samples and displayed interesting differences, revealing characteristic dietary and cultural features between the subjects of both countries, such as high trimethylamine-N-oxide (TMAO)-excretion in the Swedish population and high taurine-excretion, due to the Atkins diet. This study suggests that the endogenous urinary profile is subject to distinct cultural and severe dietary influences and that great care needs to be taken in the interpretation of 'biomarkers of disease and response to drug therapy' for diagnostic purposes.

Cyclosporin A-induced changes in endogenous metabolites in rat urine: a metabonomic investigation using high field 1H NMR spectroscopy, HPLC-TOF/MS and chemometrics.

The model nephrotoxin cyclosporin A was administered to male Wistar-derived rats daily for 9 days at a dose level of 45 mg/kg per day. Urine samples were collected daily and the excretion pattern of low molecular mass organic molecules in the urine was studied using 1H NMR spectroscopy and HPLC-TOF/MS. Distinct changes in the pattern of endogenous metabolites, as a result of the daily administration of cyclosporin A, were observed by 1H NMR from day 7 onwards. The NMR-detected markers included raised concentrations of glucose, acetate, trimethylamine and succinate and reduced amounts of trimethylamine-N-oxide. In parallel studies by HPLC-TOF/MS a reduction in the quantities of kynurenic acid, xanthurenic acid, citric acid and riboflavin present in the urines was noted, together with reductions in a number of as yet unidentified compounds. In addition, signals resulting from the polyethylene glycol, present in the dosing vehicle, and cyclosporin A metabolites were detected by MS. However, these were excluded from the subsequent multivariate data analysis in order to highlight only changes to the endogenous metabolites. Analysis of both the 1H NMR and HPLC-MS spectroscopic data using pattern recognition techniques clearly identified the onset of changes due to nephrotoxicity.

A metabonomic investigation of the biochemical effects of mercuric chloride in the rat using 1H NMR and HPLC-TOF/MS: time dependent changes in the urinary profile of endogenous metabolites as a result of nephrotoxicity.

The effects of the administration of a single dose of the model nephrotoxin mercuric chloride (2.0 mg kg(-1), subcutaneous) to male Wistar-derived rats on the urinary metabolite profiles of a range of endogenous metabolites has been investigated using (1)H NMR and HPLC-MS. Urine samples were collected daily for 9 days from both dosed and control animals. Analysis of these samples revealed marked changes in the pattern of endogenous metabolites as a result of HgCl(2) toxicity. Peak disturbances in the urinary metabolite profiles were observed (using both NMR and HPLC-MS) at 3 days post dose. Thereafter the urinary metabolite profile gradually returned to a more normal composition. Markers of toxicity identified by (1)H NMR spectroscopy were raised concentrations of lactate, alanine, acetate, succinate, trimethylamine (TMA), and glucose. Reductions in the urinary excretion of citrate and alpha-ketoglutarate were also seen. Markers identified by HPLC-MS, in positive ion mode, were kynurenic acid, xanthurenic acid, pantothenic acid and 7-methylguanine which decreased after dosing. In addition an ion at m/z 188, probably 3-amino-2-naphthoic acid, was observed to increase after dosing. As well as these identified compounds other ions at m/z 297 and 267 decreased after dosing. In negative ion mode a range of sulfated compounds were observed, including phenol sulfate and benzene diol sulfate, which decreased after dosing. As well as the sulfated components an unidentified glucuronide at m/z 326 was also observed to decrease after dosing. The results of this study demonstrate the complementary nature of the NMR and MS-based techniques for metabonomic analysis.