RESUMEN
Conventional endoscopic biopsy tests are not suitable for early detection of the acute onset and progression of peptic ulcer as well as various gastric complications. This also limits its suitability for widespread population-based screening and consequently, many people with complex gastric phenotypes remain undiagnosed. Here, we demonstrate a new non-invasive methodology for accurate diagnosis and classification of various gastric disorders exploiting a pattern-recognition-based cluster analysis of a breathomics dataset generated from a simple residual gas analyzer-mass spectrometry. The clustering approach recognizes unique breathograms and "breathprints" signatures that clearly reflect the specific gastric condition of an individual person. The method can selectively distinguish the breath of peptic ulcer and other gastric dysfunctions like dyspepsia, gastritis, and gastroesophageal reflux disease patients from the exhaled breath of healthy individuals with high diagnostic sensitivity and specificity. Moreover, the clustering method exhibited a reasonable power to selectively classify the early-stage and high-risk gastric conditions with/without ulceration, thus opening a new non-invasive analytical avenue for early detection, follow-up, and fast population-based robust screening strategy of gastric complications in the real-world clinical domain.
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Dispepsia , Gastritis , Úlcera Péptica , Humanos , Pruebas Respiratorias/métodos , Úlcera Péptica/complicaciones , Úlcera Péptica/diagnóstico , Dispepsia/complicaciones , Dispepsia/diagnóstico , Gastritis/diagnóstico , Gastritis/complicaciones , Sensibilidad y EspecificidadRESUMEN
Purulia is a malaria-prone district in West Bengal, India, with approximately half of the blocks defined as malaria endemic. We analyzed the malaria case in each block of the Purulia district from January 1, 2016, to December 31, 2020. As per the API, 20 blocks of Purulia were assigned to four different categories (0-3) and mapped using ArcGIS software. An exponential decay model was fitted to forecast the trend of malaria cases for each block of Purulia (2021-2025). There was a sharp decrease in total malaria cases and API from 2016 to 2020 due to the mass distribution of LLINs. The majority of cases (72.63%) were found in ≥ 15-year age group. Males were more prone to malaria (60.09%). Malaria was highly prevalent among Scheduled Tribes (48.44%). Six blocks were reported in Category 3 (high risk) and none in Category 0 (no risk) in 2016, while no blocks were determined to be in Category 3, and three blocks were in Category 0 in 2020. The exponential decay model prediction is oriented towards gaining malaria-free status in thirteen blocks of Purulia by 2025. This study will incite the government to uphold and strengthen the current efforts to meet the malaria elimination goals.
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MalariaRESUMEN
Thalassemia and hemoglobinopathies are the most common cause of high morbidity and mortality in India. Detection of carriers and premarital counseling play an important role in preventing the birth of a thalassemic child. The present study aimed to detect large numbers of asymptomatic carriers in rural areas of West Bengal, India. The present cross-sectional study was conducted over a period of 10 years. Thalassemia awareness programs and detection camps were organized at the community level. After signed written consent was obtained, the collected blood samples were subjected to a complete blood count (CBC) in an automated blood cell counter and then analyzed by high performance liquid chromatography (HPLC); in difficult cases, samples were sent to the reference laboratory for molecular characterization. Out of 287,258 samples collected, 32,921 (11.46%) cases revealed abnormal hemoglobins (Hbs); of these, 31,782 (11.06%) carried heterozygous states (carriers/traits), and the remainder were either homozygous or compound heterozygous for different hemoglobinopathies. Two common variants were revealed in the study, namely ß-thalassemia (ß-thal) (7.23%) and Hb E [ß26(B8)GluâLys, HBB: c.79G>A] (2.77%) traits. Among homozygous or compound heterozygous states, Hb E/ß-thal (0.14%) and ß-thal major (ß-TM) (0.12%) were predominant. In rural areas of West Bengal, the most common Hb variants detected were ß-thal and Hb E traits. In view of the high prevalence of hemoglobinopathies in this region, routine premarital screening and genetic counseling should be emphasized and encouraged to prevent the birth of a thalassemic child, and thus curtailing the burden on families and the health economy.
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Hemoglobinopatías/epidemiología , Población Rural , Talasemia alfa/epidemiología , Talasemia beta/epidemiología , Alelos , Biomarcadores , Cromatografía Líquida de Alta Presión , Estudios Transversales , Índices de Eritrocitos , Genotipo , Hemoglobinopatías/diagnóstico , Hemoglobinopatías/etiología , Humanos , India/epidemiología , Tamizaje Masivo , Vigilancia de la Población , Prevalencia , Globinas alfa/genética , Talasemia alfa/diagnóstico , Talasemia alfa/etiología , Globinas beta/genética , Talasemia beta/diagnóstico , Talasemia beta/etiologíaRESUMEN
Water, the major body fluid in humans, has four main naturally occurring isotopologues, H216O, H217O, H218O, and H2H16O (i.e., HD16O) with different masses. The underlying mechanisms of the isotope-specific water-metabolism in the human gastrointestinal (GI) tract and respiratory system are largely unknown and remained illusive for several decades. Here, a new strategy has been demonstrated that provides direct quantitative experimental evidence of triple-isotopic signatures of water-metabolism in the human body in response to the individual's water intake habit. The distribution of water isotopes has been monitored in drinking water (DW; δD = -36.59 ± 10.64 (SD), δ18O = -5.41 ± 1.47 (SD), and δ17O = -2.92 ± 0.79 (SD)), GI fluid (GF; δD = -35.91 ± 7.30 (SD), δ18O = -3.98 ± 1.29 (SD), and δ17O = -2.37 ± 0.57 (SD)), and human exhaled breath (EB; δD = -119.63 ± 7.27 (SD), δ18O = -13.69 ± 1.23 (SD), and δ17O = -8.77 ± 0.98 (SD)) using a laser-based off-axis integrated cavity output spectroscopy (OA-ICOS) technique. This study explored a new analytical method to disentangle the competing effects of isotopic fractionations of water during respiration in humans. In addition, our findings revealed that deuterium-enriched exhaled semiheavy water, i.e., HD16O is a new marker of the noninvasive assessment of the ulcer-causing H. pylori gastric pathogen. We also clearly showed that the water-metabolism-derived triple-isotopic compositions due to impaired water absorption in the GI tract can be used as unique tracers to track the onset of various GI dysfunctions. These findings are thus bringing a new analytical methodology to better understand the isotope-selective water-metabolism that will have enormous applications for clinical testing purposes.
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Líquidos Corporales/química , Agua Potable/análisis , Sistema Respiratorio/química , Agua/análisis , Adolescente , Adulto , Anciano , Deuterio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isótopos de Oxígeno , Análisis Espectral , Adulto JovenRESUMEN
We report on the development of a simple, linear optical cavity-based system combining evanescent wave (EW) with high-sensitive cavity ring-down spectroscopy (CRDS) technique using a diode laser at 644 nm and a right-angled prism for evanescent field generation on prism surface. We characterized the setup in detail and achieved an optimum ring-down time of 159.4 ns and a minimum absorption coefficient of αmin = 1.67 × 10-6 cm-1. We utilized this setup to investigate the salt-induced aggregation kinetics of gold (Au) and silver (Ag) nanoparticles (NPs) at the prism interface with high-sensitivity. We evaluated the extinction rates on the surface due to Au and Ag NPs aggregation and examined the variations due to their respective concentrations. To demonstrate the applicability of the developed EW-CRDS prototype setup to different molecular systems, we investigated the urease-bound aggregation kinetics of the Au and Ag NPs which has not been explored earlier by this linear cavity geometry. We finally illustrated the aggregation dynamics through surface imaging, thus demonstrating an alternative analytical approach to monitor interfacial phenomena using EW-CRDS technique.
RESUMEN
The underlying mechanisms of the triple-oxygen (16O, 17O, and 18O) isotopic content of deuterated (D) isotopologues of water in H-D exchange reactions in the gas phase remain elusive. Herein, we have demonstrated a high-resolution gas-phase spectral analysis of doubly (D2O) and singly (HDO) deuterated isotopologues of water in the region around 7.8 µm using quantum cascade laser-based cavity ring-down spectroscopy. Isotopic fractionations among doubly and singly deuterated species of water, D216O, HD16O, HD17O, and HD18O, in the gas phase were carried out by probing the fundamental and hot band transitions in the ν2 (bending) mode of D2O and the fundamental ν2 transitions for the other water isotopes. We subsequently investigated the fractionations of different D-enriched water isotopologues for the H-D exchange reaction using various mixtures of D2O in H2O. We explored the potential role of triple-oxygen isotopic contents through enrichments and depletions of HD16O, HD17O, and HD18O, involved in the H-D reaction. Our first clear, direct, and quantitative experimental evidence reveals a new picture of gas-phase isotopic fractionation chemistry in a mixture of light and heavy water (H2O-D2O).
RESUMEN
Over the past several decades, it has been generally believed that microbial nitrification and denitrification are not significant processes in the human gastrointestinal tract. Moreover, the underlying physiological link between exhaled nitrous oxide (N2O) and aerobic denitrification in the gastric environment is still largely unknown. In this report, we provide direct experimental evidence of the aerobic denitrification process in the human gastrointestinal tract by evaluating concentrations of dissolved N2O and its precursor nitrite ([Formula: see text]) ion in the gastric juice along with exhaled N2O concentration using a high-precision laser spectroscopy technique. Moreover, in vitro studies of gastric fluid in patients reveal a new mechanism of nitrification of ammonium ion ([Formula: see text]) followed by denitrification of [Formula: see text] leading to the formation of N2O in the gastric environment, which is eventually excreted in exhaled breath. This observation was subsequently validated under in vivo physiological conditions exploiting the urease activity of the gastric pathogen Helicobacter pylori. Consequently, our findings established a strong physiological link between exhaled N2O and bacterial infection in the stomach. This deepens our understanding of the unusual microbial denitrification in the gastric environment, providing new insight into the activities of human-associated microorganisms, which eventually affect the human physiology and health.
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Pruebas Respiratorias/métodos , Desnitrificación , Jugo Gástrico/metabolismo , Nitrificación , Óxido Nitroso/análisis , Tracto Gastrointestinal/microbiología , Helicobacter pylori/fisiología , Humanos , Redes y Vías Metabólicas , Análisis EspectralRESUMEN
Helicobacter pylori causes several gastrointestinal diseases and may also contribute to the development of type 2 diabetes (T2D). Several studies suggest that there might be a potential link between H. pylori infection and T2D, but it still remains the subject of debate. Here, we first report the cumulative effect of H. pylori infection and T2D by exploiting the excretion kinetics of 13C/12C and 18O/16O isotope ratios of exhaled breath CO2 in response to an oral dose of 13C-enriched glucose in individuals with T2D and non-diabetic controls (NDC) harbouring the H. pylori infection. Using a high-resolution integrated cavity output spectroscopy (ICOS) technique in the infrared region, we observed that the isotopic fractionations of 13C and 18O in breath CO2 are distinctly altered in H. pylori infected T2D patients as well as in H. pylori infected NDC. Several optimal diagnostic cut-off points of 13C and 18O isotopes of breath CO2 were also determined which exhibited the diagnostic sensitivity and specificity of â¼97â % and thus suggesting that breath 13C and 18O isotopes might be considered as potential biomarkers for the non-invasive assessment of the gastric pathogen prior to the onset of T2D. This may open a new diagnostic strategy for treating these common diseases in an alternative way.
Asunto(s)
Pruebas Respiratorias/métodos , Isótopos de Carbono/análisis , Diabetes Mellitus Tipo 2/diagnóstico , Infecciones por Helicobacter/diagnóstico , Isótopos de Oxígeno/análisis , Adulto , Biomarcadores/análisis , Femenino , Helicobacter pylori/fisiología , Humanos , Cinética , Masculino , Persona de Mediana EdadRESUMEN
We report on the development of a mid-infrared cavity ring-down spectrometer (CRDS) coupled with a continuous wave (cw) external cavity quantum cascade laser (EC-QCL), operating between 6.0 µm and 6.3 µm, for high-resolution spectroscopic studies of ammonia (NH3) which served as a bench-mark molecule in this spectral region. We characterized the EC-QCL based CRDS system in detail and achieved a noise-equivalent absorption (NEA) coefficient of 2.11 × 10-9 cm-1 Hz-1/2 for a 100 Hz data acquisition rate. We thereafter exploited the system for high-resolution spectroscopic analysis of interference-free 10 transition lines of the ν4 fundamental vibrational band of NH3 centred at â¼6.2 µm. We probed the strongest interference-free absorption line RQ(4,3) of ν4, centred at 1613.370 cm-1 for highly-sensitive trace detection of NH3 and subsequently achieved a minimum detection sensitivity (1σ) of 2.78 × 109 molecules per cm3 which translated into the detection limit of 740 parts-per-trillion by volume (pptv/10-12) at a pressure of 115 Torr for an integration time of â¼167 seconds. To demonstrate the efficacy of the present system in real-life applications, we finally measured the mixing ratios of NH3 present in ambient air and human exhaled breath with high sensitivity and molecular specificity.
RESUMEN
Nitric oxide (NO) plays a key role in the development of peptic ulcer disease (PUD). Conversely, the gastric pathogen Helicobacter pylori colonizes the human stomach and contributes to the development of non-ulcer dyspepsia (NUD) and PUD. However, the underlying relation between molecular NO in exhaled breath and H. pylori-associated NUD and PUD remains largely unknown. Here, we found that the excretion kinetics of NO profiles in exhaled breath are altered markedly in H. pylori-infected NUD and PUD subjects. In our observations, PUD led to considerably higher enrichments of NO in exhaled breath compared to NUD, thus revealing a potential link between exhaled NO and ulcer and non-ulcer complications. Our findings therefore suggest that molecular NO in exhaled breath could be used as a potential biomarker for non-invasive diagnosis and selective differentiation of NUD from PUD. Our observations also highlight that alterations of NO in the gastric environment can play an important role in the pathogenesis of peptic ulcers and thus may provide a new strategy for precise evolution of the actual disease state without the need for endoscopic biopsy, even after the eradication of H. pylori infection.
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Dispepsia/diagnóstico , Espiración , Óxido Nítrico/análisis , Úlcera Péptica/diagnóstico , Biomarcadores/análisis , Pruebas Respiratorias , Dispepsia/complicaciones , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/fisiología , Humanos , Cinética , Úlcera Péptica/complicaciones , Curva ROC , Reproducibilidad de los ResultadosRESUMEN
The 13C-urea breath test (13C-UBT), developed a few decades ago, is widely used as a non-invasive diagnostic method to detect only the presence of the gastric pathogen Helicobacter pylori infection; however, the actual disease state, i.e. whether the person harbouring H. pylori has peptic ulcer disease (PUD) or non-ulcerous dyspepsia (NUD), is still poorly understood. Nevertheless, the present 13C-UBT has numerous limitations, drawbacks and pitfalls owing to the ingestion of 13C-labelled external urea. Here, we show that H. pylori is able to utilize the natural 13C and 18O-urea inherently present in the gastric juice in humans for its urease activity which has never been explored before. In vitro measurements of isotopic fractionations of gastric juice urea provide new insights into the actual state of the infection of PUD or NUD. We also provide evidence of the unusual 13C and 18O-isotopic fractionations of breath CO2 that are distinctively altered in individuals with PUD encompassing both gastric and duodenal ulcers as well as with NUD by the enzymatic activity of H. pylori in the gastric niche without oral administration of any 13C-enriched external urea. This deepens our understanding of the UBT exploiting the natural 13C and 18O-gastric juice urea in the pathogenesis of H. pylori infection, reveals the actual disease state of PUD or NUD and thus offers novel opportunities for a simple, robust, cost-effective and non-toxic global strategy devoid of any 13C-enriched urea for treating these common diseases by a single breath test. Graphical Abstract Urea breath test without any external urea.
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Dispepsia/diagnóstico , Jugo Gástrico/química , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Úlcera Péptica/diagnóstico , Urea/análisis , Adolescente , Adulto , Anciano , Pruebas Respiratorias , Isótopos de Carbono/análisis , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isótopos de Oxígeno/análisis , Adulto JovenRESUMEN
The inability to envisage the acute onset and progression of type 1 diabetes (T1D) has been a major clinical stumbling block and an important area of biomedical research over the last few decades. Therefore there is a pressing need to develop a new and an effective strategy for early detection of T1D and to precisely distinguish T1D from type 2 diabetes (T2D). Here we describe the precise role of the enzymatic activity of carbonic anhydrase (CA) in erythrocytes in the pathogenesis of T1D and T2D. We show that CA activities are markedly altered during metabolism of T1D and T2D and this facilitates to the oxygen-18 (18O) isotopic fractionations of breath CO2. In our observations, T1D exhibited considerable depletions of 18O-isotopes of CO2, whereas T2D manifested isotopic enrichments of 18O in breath CO2, thus unveiling a missing link of breath18O-isotopic fractionations in T1D and T2D. Our findings suggest that the alterations in erythrocytes CA activities may be the initial step of altered metabolism of T1D and T2D, and breath 18O-isotope regulated by the CA activity is a potential diagnostic biomarker that can selectively and precisely distinguish T1D from T2D and thus may open a potential unifying strategy for treating these diseases.
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Dióxido de Carbono/metabolismo , Anhidrasas Carbónicas/metabolismo , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 2/diagnóstico , Eritrocitos/enzimología , Adolescente , Adulto , Pruebas Respiratorias , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Hemoglobina Glucada/análisis , Humanos , Marcaje Isotópico , Cinética , Masculino , Persona de Mediana Edad , Isótopos de Oxígeno/química , Espectrofotometría , Adulto JovenRESUMEN
The gastric pathogen Helicobacter pylori utilizes molecular hydrogen (H2) as a respiratory substrate during colonization in the gastric mucosa. However, the link between molecular H2 and the pathogenesis of peptic-ulcer disease (PUD) and non-ulcerous dyspepsia (NUD) by the enzymatic activity of H. pylori still remains mostly unknown. Here we provide evidence that breath H2 excretion profiles are distinctly altered by the enzymatic activity of H. pylori for individuals with NUD and PUD. We subsequently unravelled the potential molecular mechanisms responsible for the alteration of H2 in exhaled breath in association with peptic ulcers, encompassing both gastric and duodenal ulcers, along with NUD. We also established that carbon-isotopic fractionations in the acid-mediated bacterial environment regulated by bacterial urease activity cannot discriminate the actual disease state i.e. whether it is peptic ulcer or NUD. However, our findings illuminate the unusual molecular H2 in breath that can track the precise evolution of PUD and NUD, even after the eradication of H. pylori infection. This deepens our understanding of the pathophysiology of PUD and NUD, reveals non-invasively the actual disease state in real-time and thus offers a novel and robust new-generation strategy for treating peptic-ulcer disease together with non-ulcer related complications even when the existing (13)C-urea breath test ((13)C-UBT) fails to diagnose.
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Pruebas Respiratorias/métodos , Dispepsia/diagnóstico , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/fisiología , Hidrógeno/análisis , Úlcera Péptica/diagnóstico , Adolescente , Adulto , Anciano , Isótopos de Carbono , Espiración , Femenino , Humanos , Cinética , Masculino , Persona de Mediana Edad , Modelos Biológicos , Úlcera Péptica/complicaciones , Curva ROC , Adulto JovenRESUMEN
A high-resolution cavity ring-down spectroscopic (CRDS) system based on a continuous wave (cw) mode-hop-free (MHF) external-cavity quantum cascade laser (EC-QCL) operating at λâ¼5.2 µm has been developed for ultrasensitive detection of nitric oxide (NO). We report the performance of the high-resolution EC-QCL based cw-CRDS instrument by measuring the rotationally resolved Λ-doublet e and f components of the P(7.5) line in the fundamental band of NO at 1850.169 cm-1 and 1850.179 cm-1. A noise-equivalent absorption coefficient of 1.01×10-9 cm-1 Hz-1/2 was achieved based on an empty cavity ring-down time of τ0=5.6 µs and standard deviation of 0.11% with averaging of six ring-down time determinations. The CRDS sensor demonstrates the advantages of measuring parts per billion NO concentrations in N2, as well as in human breath samples with ultrahigh sensitivity and specificity. The CRDS system could also be generalized to measure simultaneously many other trace molecular species within the broad tuning range of cw EC-QCL, as well as for studying the rotationally resolved hyperfine structures.
RESUMEN
A residual gas analyzer (RGA) coupled with a high-vacuum chamber has been explored to measure atmospheric CO2 entrapped in aminosilane-modified clay nanotubes. Ambient CO2 uptake efficacy together with stability of these novel adsorbents composed of both primary and/or secondary amine sites has been demonstrated at standard ambient temperature and pressure. The unprecedented sensitivity and accuracy of the RGA-based mass spectrometry technique toward atmospheric CO2 measurement has been substantiated with a laser-based optical cavity-enhanced integrated cavity output spectroscopy. The adsorption kinetics of atmospheric CO2 on amine-functionalized clay nanotubes followed the fractional-order kinetic model compared to that of the pseudo-first-order or pseudo-second-order rate equations. The efficiency along with stability of these novel adsorbents has also been demonstrated by their repetitive use for CO2 capture in the oxidative environment. Our findings thus point to a fundamental study on the atmospheric CO2 adsorption by amine-loaded adsorbents using an easy handling and low-cost benchtop RGA-based mass spectrometer, opening a new strategy for CO2 capture and sequestering study.
RESUMEN
The gastric pathogen Helicobacter pylori utilize glucose during metabolism, but the underlying mechanisms linking to oxygen-18 ((18)O) and carbon-13 ((13)C)-isotopic fractionations of breath CO2 during glucose metabolism are poorly understood. Using the excretion dynamics of (18)O/(16)O and (13)C/(12)C-isotope ratios of breath CO2, we found that individuals with Helicobacter pylori infections exhibited significantly higher isotopic enrichments of (18)O in breath CO2 during the 2h-glucose metabolism regardless of the isotopic nature of the substrate, while no significant enrichments of (18)O in breath CO2 were manifested in individuals without the infections. In contrast, the (13)C-isotopic enrichments of breath CO2 were significantly higher in individuals with Helicobacter pylori compared to individuals without infections in response to (13)C-enriched glucose uptake, whereas a distinguishable change of breath (13)C/(12)C-isotope ratios was also evident when Helicobacter pylori utilize natural glucose. Moreover, monitoring the (18)O and (13)C-isotopic exchange in breath CO2 successfully diagnosed the eradications of Helicobacter pylori infections following a standard therapy. Our findings suggest that breath (12)C(18)O(16)O and (13)C(16)O(16)O can be used as potential molecular biomarkers to distinctively track the pathogenesis of Helicobacter pylori and also for eradication purposes and thus may open new perspectives into the pathogen's physiology along with isotope-specific non-invasive diagnosis of the infection.
Asunto(s)
Dióxido de Carbono/metabolismo , Isótopos de Carbono/metabolismo , Espiración , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/microbiología , Helicobacter pylori/metabolismo , Isótopos de Oxígeno/metabolismo , Adulto , Pruebas Respiratorias , Estudios de Casos y Controles , Femenino , Glucosa/metabolismo , Infecciones por Helicobacter/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Curva ROCRESUMEN
With the aim to capture and subsequent selective trapping of CO2, a nanocomposite has been developed through selective modification of the outer surface of the halloysite nanotubes (HNTs) with an organosilane to make the nanocomposite a novel solid-phase adsorbent to adsorb CO2 from the atmosphere at standard ambient temperature and pressure. The preferential adsorption of three major abundant isotopes of CO2 ((12)C(16)O2, (13)C(16)O2, and (12)C(16)O(18)O) from the ambient air by amine functionalized HNTs has been explored using an optical cavity-enhanced integrated cavity output spectroscopy. CO2 adsorption/desorption cycling measurements demonstrate that the adsorbent can be regenerated at relatively low temperature and thus, recycled repeatedly to capture atmospheric CO2. The amine grafted halloysite shows excellent stability even in oxidative environments and has high efficacy of CO2 capture, introducing a new route to the adsorption of isotope selective atmospheric CO2.
RESUMEN
Carbonic anhydrase (CA), a well-characterized metalloenzyme, is associated with oxygen-18 ( (18)O)-isotopic fractionations of CO2. To investigate how CA activity links the (18)O of breath CO2 to pre-diabetes (PD) and type 2 diabetes (T2D) during metabolism, we studied pre- and post-dose CA activities in erythrocytes with simultaneous monitoring of (18)O/ (16)O-isotope ratios of breath CO2 and thereafter elucidated potential metabolic pathways underlying CA alteration in the pathogenesis of T2D. Here we show that the post-dose CA activity in both T2D and PD was markedly enhanced, whereas the non-diabetic controls (NDC) exhibited a considerable reduction in post-dose CA activity when compared with their basal CA activities. However, T2D and PD exhibited isotopic enrichments of (18)O in breath CO2, while a marked depletion of (18)O in CO2 was manifested in NDC. Thus, the isotopic enrichments and depletions of (18)O in breath CO2 were well correlated with the changes in CA activities for controls, PD and T2D. Our findings suggest the changes in CA activities in erythrocytes may contribute to the pathogenesis of T2D and the breath C (18)O (16)O regulated by the CA activity as a potential biomarker for non-invasive assessment of T2D, and thus may open a new method for treating T2D.
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Pruebas Respiratorias/métodos , Dióxido de Carbono/metabolismo , Anhidrasas Carbónicas/metabolismo , Diabetes Mellitus Tipo 2/diagnóstico , Eritrocitos/enzimología , Estado Prediabético/diagnóstico , Adulto , Biomarcadores/metabolismo , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/sangre , Ayuno/sangre , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Masculino , Redes y Vías Metabólicas , Isótopos de Oxígeno , Estado Prediabético/sangre , Estado Prediabético/enzimologíaRESUMEN
We report, for the first time, the clinical feasibility of a novel residual gas analyzer mass spectrometry (RGA-MS) method for accurate evaluation of the (13)C-glucose breath test ((13)C-GBT) in the diagnosis of pre-diabetes (PD) and type 2 diabetes mellitus (T2D). In T2D or PD, glucose uptake is impaired and results in blunted isotope enriched (13)CO2 production in exhaled breath samples. Using the Receiver operating characteristics (ROC) curve analysis, an optimal diagnostic cut-off point of the (13)CO2/(12)CO2 isotope ratios expressed as the delta-over-baseline (DOB) value, was determined to be δDOB(13)C = 28.81 for screening individuals with non-diabetes controls (NDC) and pre-diabetes (PD), corresponding to a sensitivity of 100% and specificity of 94.4%. We also determined another optimal diagnostic cut-off point of δDOB(13)C = 19.88 between individuals with PD and T2D, which exhibited 100% sensitivity and 95.5% specificity. Our RGA-MS methodology for the (13)C-GBT also manifested a typical diagnostic positive and negative predictive value of 96% and 100%, respectively. The diagnostic accuracy, precision and validity of the results were also confirmed by high-resolution optical cavity enhanced integrated cavity output spectroscopy (ICOS) measurements. The δDOB(13)C values measured with RGA-MS method, correlated favourably (R(2) = 0.979) with those determined by the laser based ICOS method. Moreover, we observed that the effects of endogenous CO2 production related to basal metabolic rates in individuals were statistically insignificant (p = 0.37 and 0.73) on the diagnostic accuracy. Our findings suggest that the RGA-MS is a valid and sufficiently robust method for the (13)C-GBT which may serve as an alternative non-invasive point-of-care diagnostic tool for routine clinical practices as well as for large-scale diabetes screening purposes in real-time.