Glucagon-like peptide 1 has a physiological role in the control of postprandial glucose in humans: studies with the antagonist exendin 9-39

Glucagon-like peptide 1(7-36) amide (GLP-1) is postulated to be the major physiological incretin in humans, but evidence is indirect. We report the first studies examining the physiological role of GLP-1 in the postprandial state in humans using the GLP-1 antagonist exendin 9-39. Exendin 9-39 completely blocked GLP-1-induced glucose-stimulated insulin release from perifused human islets of Langerhans. In healthy fasted volunteers, intravenous infusion of exendin 9-39 at 500 pmol x kg(-1) x min(-1) in the hyperglycemic state abolished the insulinotropic effect of a physiological dose of GLP-1 and fully reversed the glucose-lowering effect of GLP-1. Nine healthy subjects consumed a 150-g oral glucose tolerance test and were infused with 500 pmol x kg(-1) x min(-1) exendin 9-39 or saline. Exendin 9-39 increased the peak postprandial glucose level (exendin 9-39, 8.67 +/- 0.35 vs. saline, 7.67 +/- 0.35 mmol/l, P < or = 0.005) and increased postprandial plasma glucose incremental area under the curve by 35% (exendin 9-39, 152 +/- 19 vs. saline, 113 +/- 16 mmol x min x l(-1), P < or = 0.05). This could be explained as partly secondary to the blockade of glucose-induced suppression of glucagon and maybe also to an increased rate of gastric emptying. Thus, in humans exendin 9-39 acts as an antagonist of GLP-1 both in vitro and in vivo. When infused alone, exendin 9-39 causes a deterioration in postprandial glycemic control, suggesting that GLP-1 may be important for maintenance of normal postprandial glucose homeostasis in humans.

Cell toxicity of superparamagnetic iron oxide nanoparticles

The performance of nanoparticles for biomedical applications is often assessed by their narrow size distribution, suitable magnetic saturation and low toxicity effects. In this work, superparamagnetic iron oxide nanoparticles (SPIONs) with different size, shape and saturation magnetization levels were synthesized via a co-precipitation technique using ferrous salts with a Fe(3+)/Fe(2+) mole ratio equal to 2. A parametric study is conducted, based on a uniform design-of-experiments methodology and a critical polymer/iron mass ratio (r-ratio) for obtaining SPION with narrow size distribution, suitable magnetic saturation, and optimum biocompatibility is identified. Polyvinyl alcohol (PVA) has been used as the nanoparticle coating material, owing to its low toxicity. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay is used to investigate the cell biocompatibility/toxicity effects of the samples. From the MTT assay results, it is observed that the biocompatibility of the nanoparticles, based on cell viabilities, can be enhanced by increasing the r-ratio, regardless of the stirring rate. This effect is mainly due to the growth of the particle hydrodynamic size, causing lower cell toxicity effects.

Use of CA-125 to define progression of ovarian cancer in patients with persistently elevated levels

PURPOSE

To determine an accurate definition for progression of ovarian cancer in patients with a persistently elevated serum CA-125.

PATIENTS AND METHODS

A retrospective analysis was performed on 300 patients with epithelial ovarian carcinoma with at least one measurement of CA-125. The date of progression according to clinical or radiologic criteria was ascertained in the 88 patients with persistently elevated CA-125 levels (> 23 U/mL). This was compared with the date of progression according to CA-125, defined as the date on which the CA-125 level first increased to >or= twice its nadir level, confirmed by a second sample also >or= twice the nadir.

RESULTS

Eighty of the 88 patients had evidence of progression by both standard and CA-125 criteria, giving a sensitivity of 94%. In six of these patients, no sample was taken to confirm CA-125 doubling. In 13 patients, CA-125 doubling occurred after the date of clinical progression. Only one patient had a false-positive prediction of progression according to CA-125; the patient died as a result of a myocardial infarct before evidence of clinical progression.

CONCLUSION

In patients whose CA-125 level decreases to normal after chemotherapy, a doubling from the upper limit of normal has been shown to predict progression. In those with persistently elevated levels, doubling of CA-125 from its nadir level has now been shown to accurately define progression. If confirmed, these CA-125 criteria should be used as additional end points in clinical trials.

Chronic intermittent ethanol treatment in rats increases GABA(A) receptor alpha4-subunit expression: possible relevance to alcohol dependence

Chronic administration of ethanol to rats on an intermittent regimen, for 60 repeated intoxicating doses and repeated withdrawal episodes, results in a long-lasting kindling phenomenon. This involves an increasing severity of withdrawal, including a reduced threshold to seizures produced by the GABA(A) antagonist, pentylenetetrazol. We have shown previously that muscimol-evoked 36Cl- efflux and paired-pulse inhibition (involving GABA(A)-mediated recurrent inhibition) were decreased persistently in the CA1 region of hippocampal slices from chronic intermittent ethanol (CIE)-treated rats. We now report elevated levels of mRNA in forebrain for the alpha4 subunit of the GABA(A) receptor (GABAR), considered to be a constituent of pharmacologically and physiologically novel subtypes of GABARs. Using in situ hybridization with digoxigenin-labeled RNA probes, we show that at 2 days withdrawal, 60-dose CIE leads to a significant 30% increase in alpha4 subunit mRNA levels in the dentate gyrus, 46% increase in the CA3, and 26% increase in the CA1 regions. In contrast, there was no significant change in the mRNAs for the alpha5 subunit or glutamic acid decarboxylase 67 in the same regions. This study suggests that GABAR subunit-selective alterations occur after CIE treatment, possibly resulting in the alteration of the subunit composition of GABARs, with presumably altered physiological functions. This plasticity of GABARs may contribute to the increased withdrawal severity, reduced hippocampal inhibition, and increased seizure susceptibility of this animal model of human alcohol dependence.

Current Developments in Antimicrobial Surface Coatings for Biomedical Applications

Bacterial adhesion and subsequent biofilm formation on material surfaces represent a serious problem in society from both an economical and health perspective. Surface coating approaches to prevent bacterial adhesion and biofilm formation are of increased importance due to the increasing prevalence of antibiotic resistant bacterial strains. Effective antimicrobial surface coatings can be based on an anti-adhesive principle that prevents bacteria to adhere, or on bactericidal strategies, killing organisms either before or after contact is made with the surface. Many strategies, however, implement a multifunctional approach that incorporates both of these mechanisms. For anti-adhesive strategies, the use of polymer chains, or hydrogels is preferred, although recently a new class of super-hydrophobic surfaces has been described which demonstrate improved anti-adhesive activity. In addition, bacterial killing can be achieved using antimicrobial peptides, antibiotics, chitosan or enzymes directly bound, tethered through spacer-molecules or encased in biodegradable matrices, nanoparticles and quaternary ammonium compounds. Notwithstanding the ubiquitous nature of the problem of microbial colonization of material surfaces, this review focuses on the recent developments in antimicrobial surface coatings with respect to biomaterial implants and devices. In this biomedical arena, to rank the different coating strategies in order of increasing efficacy is impossible, since this depends on the clinical application aimed for and whether expectations are short- or long term. Considering that the era of antibiotics to control infectious biofilms will eventually come to an end, the future for biofilm control on biomaterial implants and devices is likely with surface-associated modifications that are non-antibiotic related.

Dermatophytoses in Iran

A total of 12,150 cases of suspected dermatophytoses in different areas of Iran were studied between 1986 and 1991. The age groups most commonly infected were 1-9 and 20-29 years. Clinical diagnosis was confirmed in only 9345 cases by laboratory examination. Of these positive samples, 1633 cases were found to be positive by direct microscopic observation only, 429 by culture only and 7283 by both techniques. Scalp ringworm of children was the most common type of tinea. But according to the rate of infection, tinea corporis, tinea pedis, tinea cruris, tinea manuum, tinea unguium and tinea barbae were the next most prevalent in that order. The frequencies of dermatophytes isolated from patients were as follows: Microsporum canis 19.4%, Trichophyton rubrum 16.5%, Epidermophyton floccosum 14.9%, Trichophyton mentagrophytes var. interdigitale 14.6%, Trichophyton verrucosum 11.5%, Trichophyton mentagrophytes 6%, Trichophyton violaceum 8.7%, Trichophyton schoenleinii 5.5%, Trichophyton tonsurans 1.3%, Trichophyton erinacei 0.8% and Microsporum gallinae 0.2%.

An apolipoprotein-enriched biomolecular corona switches the cellular uptake mechanism and trafficking pathway of lipid nanoparticles

Following exposure to biological milieus (e.g. after systemic administration), nanoparticles (NPs) get covered by an outer biomolecular corona (BC) that defines many of their biological outcomes, such as the elicited immune response, biodistribution, and targeting abilities. In spite of this, the role of BC in regulating the cellular uptake and the subcellular trafficking properties of NPs has remained elusive. Here, we tackle this issue by employing multicomponent (MC) lipid NPs, human plasma (HP) and HeLa cells as models for nanoformulations, biological fluids, and target cells, respectively. By conducting confocal fluorescence microscopy experiments and image correlation analyses, we quantitatively demonstrate that the BC promotes a neat switch of the cell entry mechanism and subsequent intracellular trafficking, from macropinocytosis to clathrin-dependent endocytosis. Nano-liquid chromatography tandem mass spectrometry identifies apolipoproteins as the most abundant components of the BC tested here. Interestingly, this class of proteins target the LDL receptors, which are overexpressed in clathrin-enriched membrane domains. Our results highlight the crucial role of BC as an intrinsic trigger of specific NP-cell interactions and biological responses and set the basis for a rational exploitation of the BC for targeted delivery.

Nanoparticles-cell association predicted by protein corona fingerprints

In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a "protein corona" layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø≈ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells.

Atherogenesis: the role of inflammation and infection

Atherosclerosis is no longer considered a disorder of lipid accumulation, but a disease process characterized by the dynamic interaction between endothelial dysfunction, subendothelial inflammation and the 'wound healing response' of the vascular smooth muscle cells. Prospective epidemiological studies have unequivocally demonstrated increased vascular risk in individuals with elevated levels of (i) cytokines such as interleukin-6 and tumour necrosis factor-alpha, (ii) cell adhesion molecules such as intercellular adhesion molecule-1 and P-selectin, and (iii) acute-phase proteins such as C-reactive protein, fibrinogen and serum amyloid A. Furthermore, evidence from clinical trials have demonstrated that risk reduction achieved with anti-inflammatory agents such as statins is significantly greater in patients with evidence of inflammation. A number of risk factors for atherogenesis, including infectious agents, have been shown to exert their influence via inflammatory mechanisms. However, despite compelling experimental evidence, clinical studies looking at the role of infection in atherogenesis have lacked consistency. The clinical product of this dynamic process is variable and unpredictable between individuals, even those with apparently similar risk profiles.

Sick building syndrome. III. Stachybotrys chartarum

Increasingly, physicians are being asked to evaluate patients with putative environmentally associated illnesses. These can include a variety of problems, including infectious illnesses (Legionnaire's disease), chemical exposure in the workplace, and sick building syndromes. The latter has been an issue particularly in asthma because of the association of mold and increased bronchial responsiveness. Recently, attention has been focused on the mold Stachybotrys in human disease. Stachybotrys was first identified more than 60 years ago following an epidemic of stomatitis, rhinitis, conjunctivitis, pancytopenia, neurologic disorders, and death in horses. Since then, Stachybotrys has been identified in several outbreaks of disease in animals. It has also attracted attention as a possible agent in idiopathic pulmonary hemorrhage in infants. Stachybotrys is a relatively uncommon fungus but has been isolated from a variety of sources, including contaminated grains, tobacco, indoor air, insulator foams, and water-damaged buildings with high humidity. This fungus is particularly important because it is one of a series of fungi that produces trichothecenes mycotoxins; these mycotoxins are biologically active and can produce a variety of physiological and pathologic changes in humans and animals, including modulation of inflammation and altered alveolar surfactant phospholipid concentrations. The presence of Stachybotrys in a building does not necessarily imply a cause-and-effect relationship with illness, but should alert physicians and healthcare professionals to do more vigorous environmental testing. Guidelines are presented herein for intervention measures in the maintenance of heating, ventilation, and air-conditioning systems.

Quantification and synthesis of cocaine- and amphetamine-regulated transcript peptide (79-102)-like immunoreactivity and mRNA in rat tissues

The distribution of cocaine- and amphetamine-regulated transcript peptide (79-102)-like immunoreactivity (CART-LI) was quantified in brain and peripheral tissues of male and female Wistar rats, and male obese (fa/fa) and heterozygous (Fa/+) Zucker rats using a specific RIA. CART-LI tissue levels have not been quantified previously. The assay, using cocaine- and amphetamine-regulated transcript (CART) (79-102) as a standard and radioactive tracer and an antibody to CART (79-102) fragment, detected CART-LI in all brain regions examined, the anterior and posterior pituitary, the spinal cord and throughout the gastrointestinal tract of both male and female Wistar rats. The highest concentrations were found in the hypothalamus, duodenum, anterior pituitary and posterior pituitary (50.6+/-4.4, 26.1+/-4.2, 50.0+/-1.3 and 373.0+/-55.2 pmol/g wet tissue respectively, means+/- s.e.m., n=6-10 male animals). There was no significant variation between the sexes. The concentrations of CART-LI in hypothalami and anterior and posterior pituitaries from fa/fa rats were significantly (P<0002) lower than those of Fa/+ controls (35.9+/-2.1 vs 53.9+/-4.9,<0.6 vs 1.8+/-0.4 and 114+/-9.1 vs 255.5+/- 20.9 pmol/g wet tissue respectively, means+/- s.e.m., n=7). Gel permeation chromatography of regions of rat brain and gastrointestinal tract showed possible differential processing between regions. CART-LI was released from hypothalamic tissue slices in a calcium-dependent fashion by potassium-induced depolarisation. Northern blot analysis detected CART mRNA in the hypothalamus, anterior pituitary, brain stem, cerebellum and spinal cord. The pattern o! f distribution of CART mRNA and CART-LI in various neural and other tissues is in accord with a role for CART as a neurotransmitter.

Dermatophytes isolated from domestic animals in Iran

Between 1994 and 1998, a total of 790 feather, hair and skin specimens from a variety of animals with suspected dermatophytoses were studied, of which 248 (31.4%) yielded dermatophytes. The most frequent dermatophytes isolated were Microsporum canis (38.3%), Trichophyton verrucosum (31.8%), T. mentagrophytes (13.3%) and M. gypseum (7.7%). There was a significantly higher proportion of positive cultures from cats (54.8%) than dogs (8.2%), and M. canis was the most common species isolated (87.2 and 50% respectively). Trichophyton verrucosum was the most frequent causative agent of dermatophytoses in ruminants, M. equinum in horses, M. gypseum in rabbits, M. gallinae in chickens and T. mentagrophytes in pet squirrels.

Proinflammatory cytokine gene single nucleotide polymorphisms in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous group of primary immunodeficiency diseases. Cytokine production could be affected in CVID patients, whereas its alteration could be due to genetic polymorphisms within coding and promoter regions of the cytokine genes. This study was performed to analyse the proinflammatory cytokine single nucleotide polymorphisms in CVID. The allele and genotype frequencies of a number polymorphic genes coding tumour necrosis factor (TNF)-alpha, interleukin (IL)-1alpha, IL-1beta, IL-1R, IL-1RA and IL-6 were investigated and compared between two groups of CVID patients and controls. The IL-6 GA genotype at position nt565 was significantly over-represented in the patient group (P<0.001), while the IL-6 GG genotype at position -174 (P=0.006) and the GG genotype at position nt565 (P<0.001) were significantly lower than controls. The TNF-alpha AG genotype at position -308 in the patient group was increased significantly in comparison with controls (P=0.027), but the GG genotype at the same position was significantly decreased (P=0.011). IL-6 CA and GA haplotypes were the most frequent haplotypes in the patients (P<0.005), whereas TNF-alpha GA (P=0.002) and IL-6 GG (P<0.001) haplotypes were decreased significantly in the patients in comparison with controls. Cytokine single nucleotide polymorphisms could have a role in pathophysiology of CVID. High production of TNF-alpha is expected in some CVID patients based on the frequency of genotypes/haplotypes of these cytokine gene polymorphisms.

In vivo protein corona patterns of lipid nanoparticles

In vitro and in vivo biological identity of nanoparticles are substantially different.

Introductory Experience with the Continuous Glucose Monitoring System (CGMS®; Medtronic Minimed®) in Detecting Hyperglycemia by Comparing the Self-Monitoring of Blood Glucose (SMBG) in Non-Pregnant Women and in Pregnant Women with Impaired Glucose Tolerance and Gestational Diabetes

OBJECTIVE

To assess the detection rate of hyperglycemia with a continuous glucose monitoring system compared to a self-monitoring blood glucose profile in non-pregnant, non-diabetic pregnant women, and patients with impaired glucose tolerance or gestational diabetes..

METHODS

Eight non-pregnant (NP) and 56 pregnant women (17 dietary-treated gestational diabetics (GDM), 15 women with impaired glucose tolerance (IGT), and 24 non-diabetic pregnant women (NDP)) underwent a 72-hour measurement with the CGMS (Medtronic Minimed, Northridge, CA, USA). Self-monitored blood glucose measurements, performed 30 minutes before and 120 minutes after each meal, were compared to the duration of hyperglycemia monitored by the continuous glucose monitoring system.

RESULTS

No clinically observable infection was found at the subcutaneous tissue where the electrode was placed. A statistically significant difference was found between the groups in body mass index, HbA1c, and in gestational age, but not in age or parity. Using the self-monitored blood glucose (SMBG), 88 % (7/8) of the NP and 54 % (13/24) of the NDP had no measurement above 6.7 mmol/l. However, 17 % (4/24) of the NDP and 40 % (6/15) of the IGT showed more than two measurements above 6.7 mmol/l compared to 24 % (4/17) of the dietary-treated GDM. The differences between these groups were not significant (p = 0.21). The mean durations (+/- SD) of hyperglycemia above 6.7 mmol/l/24 h were: NP 111 +/- 120 min, NDP 138 +/- 120 min, IGT 381.8 +/- 295 min, and GDM 190 +/- 155 min, p = 0.017; above 7.8 mmol/l/24 h NP 24 +/- 49 min, NDP 38 +/- 47 min, IGT 170.7 +/- 190 min, and GDM 64 +/- 88 min, p = 0.016; and above 8.9 mmol/l/24 h NP 9.3 +/- 25 min, NDP 7.5 +/- 14 min, IGT 59 +/- 77 min, and GDM 14 +/- 21 min, p = 0.026. There was no significant difference in the fetal outcome or rate of birth percentiles using the sensor data.

CONCLUSIONS

The use of the sensor in pregnant women is unproblematic. a) The CGMS detected more frequent and longer durations of hyperglycemia in GDM compared to non-diabetic pregnant women than the SMBG. b) Women with an IGT exhibited higher glucose levels than patients with gestational diabetes. c) The clinical importance of these hyperglycemic intervals, e.g. with respect to the risk for macrosomia, must be assessed in larger trials.

Zeolite Nanoparticles for Selective Sorption of Plasma Proteins

The affinity of zeolite nanoparticles (diameter of 8-12 nm) possessing high surface area and high pore volume towards human plasma proteins has been investigated. The protein composition (corona) of zeolite nanoparticles has been shown to be more dependent on the plasma protein concentrations and the type of zeolites than zeolite nanoparticles concentration. The number of proteins present in the corona of zeolite nanoparticles at 100% plasma (in vivo state) is less than with 10% plasma exposure. This could be due to a competition between the proteins to occupy the corona of the zeolite nanoparticles. Moreover, a high selective adsorption for apolipoprotein C-III (APOC-III) and fibrinogen on the zeolite nanoparticles at high plasma concentration (100%) was observed. While the zeolite nanoparticles exposed to low plasma concentration (10%) exhibited a high selective adsorption for immunoglobulin gamma (i.e. IGHG1, IGHG2 and IGHG4) proteins. The zeolite nanoparticles can potentially be used for selectively capture of APOC-III in order to reduce the activation of lipoprotein lipase inhibition during hypertriglyceridemia treatment. The zeolite nanoparticles can be adapted to hemophilic patients (hemophilia A (F-VIII deficient) and hemophilia B (F-IX deficient)) with a risk of bleeding, and thus might be potentially used in combination with the existing therapy.

Weekly cisplatin and oral etoposide as treatment for relapsed epithelial ovarian cancer

BACKGROUND

Response rates to chemotherapy in relapsed, platinum resistant epithelial ovarian cancer remain poor. We have explored the effectiveness of weekly cisplatin combined with prolonged oral etoposide in this patient group.

PATIENTS AND METHODS

Forty-two women with relapsed, advanced ovarian cancer were treated with cisplatin 60 mg/m2 on days 1, 8, 15, 29, 36 and 43 and oral etoposide 50 mg given from day 1-14 and day 29-43. In those who were responding and tolerating treatment (n = 13) oral etoposide 50 mg was continued for two further cycles (days 1-21 repeated every 28 days). The interval since last platinum containing chemotherapy was > 6 months in 28 patients and < 6 months in 16 patients.

RESULTS

Thirty-six patients were evaluable for response according to CA 125 criteria giving an overall response rate of 44%. The response rate in evaluable patients declined with increasing numbers of previous treatments: 57% with one prior treatment, 42% with two, 40% with three or more. The response rate in patients who had received platinum chemotherapy within six months prior to treatment was 46%. The only significant non-haematological toxicity was nausea and vomiting in 4 patients who experienced greater than grade 2 toxicity. The number of patients experiencing haematological toxicity more than grade 2 was as follows: haemoglobin 3, white blood count 12, platelets 6. Sixteen patients had dose delays and two had dose reductions.

CONCLUSION

We conclude that this short but intensive regimen provides worthwhile response rates, even in those patients who would ordinarily be considered refractory to platinum, and has an acceptable toxicity profile.

Exploitation of nanoparticle–protein corona for emerging therapeutic and diagnostic applications

Exposure of nanoparticles (NPs) to biological fluids (e.g., plasma, interstitial fluid, and cytoplasm) leads to the absorption of proteins on the NP surface, forming a protein corona (PC) that drastically influences the NP physicochemical properties.

M2000 (β-D-Mannuronic Acid) as a Novel Antagonist for Blocking the TLR2 and TLR4 Downstream Signalling Pathway

To date, selective blockade of Toll-like receptor (TLR) signalling has been developed as a new approach for treatment for many inflammatory diseases. As β-D-mannuronic acid (M2000) has been known as an anti-inflammatory molecule in several experimental models, we investigated the antagonistic effects of M2000 on TLR2 and TLR4 downstream signalling transduction pathway in human embryonic kidney (HEK) 293 cell lines overexpressing TLR2/CD14 and the TLR4/MD2/CD14 complex, respectively. M2000 effectively inhibited mRNA expression of MyD88 and p65, major subunit of nuclear factor-κB, in HEK293 cells stimulated by lipoteichoic acid (LTA, a TLR2 agonist) and lipopolysaccharide (LPS, a TLR4 agonist) with no evidence of cytotoxicity. In addition, M2000 also suppressed LTA and LPS-induced production of TNF-α and IL-6 inflammatory cytokines in these cells. Furthermore, the results revealed that M2000 had no significant effect on Tollip mRNA expression as a negative regulator of TLR signalling in aforesaid cells. Overall, these data point to M2000 inhibitory effect on Toll-like receptor (TLR) 2, 4 signalling in HEK293 cells. This information might provide new insights into the possible roles of this small drug in order to introduce it as a TLR signalling pathway inhibitor. However, more studies are needed to confirm β-D-mannuronic acid antagonistic effects including the effects of M2000 on peritoneal isolated macrophages and also on blood cells in patients with inflammatory diseases such as ankylosing spondylitis.

Troponin-positive chest pain with unobstructed coronary arteries: definitive differential diagnosis using cardiac MRI

OBJECTIVE

The purpose of this study was to assess the outcome of cardiac MRI (CMRI) with late gadolinium enhancement (LGE) at outpatient follow-up in a consecutive series of patients with troponin-positive chest pain but unobstructed coronary arteries at the index admission.

METHODS

The study group comprised 91 consecutive patients who presented to our institution with cardiac chest pain, elevated troponin I and unobstructed coronary arteries on coronary angiography. All patients underwent an outpatient CMRI with LGE imaging in order to establish a definitive diagnosis.

RESULTS

The average time from coronary angiography to LGE-CMRI was 2 months. 73% of patients had no abnormality on their LGE-CMRI, 16% of patients had patchy late enhancement consistent with myocarditis and 11% had focal subendocardial or full thickness late enhancement consistent with myocardial infarction. There were no deaths in this cohort during a mean follow-up of 21 months.

CONCLUSION

LGE-CMRI is a useful tool for establishing whether such patients have definitive evidence of non-ST-segment elevation myocardial infarction (NSTEMI), and can make an important contribution to the long-term management strategy of these patients as an inappropriate diagnosis of NSTEMI carries important medical, social and financial implications.