Effectiveness of intravesical ozone in interstitial cystitis by the O'Leary-Sant symptom index.

INTRODUCTION AND HYPOTHESIS: A prospective clinical, preliminary study was performed in patients with interstitial cystitis/bladder pain syndrome (IC/BPS) who were nonresponders to conventional treatment and received intravesical ozone as a therapeutic alternative. METHODS: Sixteen patients received six applications of intravesical ozone at a concentration of 41 µg/mL. We evaluated therapeutic efficacy by the percentage reduction of Interstitial Cystitis Symptom and Problem Index scores (ICSI/ICPI-the O'Leary-Sant symptom index), recurrence rate, nonresponse, and side effects in scores collected on admission (pre-treatment), at the end of the therapeutic protocol (post-treatment), and 180 days (follow-up) after the last ozone application. RESULTS: The mean age of women was 52.9 years (SD: 15.5), and the duration of symptoms was 5.7 years (SD: 7.1). The median ICSI on admission was 17 (IQR: 14.25-19.5) and at follow-up was 0.5 (IQR: 0-2), with a reduction of 97.5% (CI: 85.7-100). The median ICSI/ICPI on admission was 31.5 (IQR: 29-35.2) and at follow-up was 2.0 (IQR: 0-3.75), with a reduction of 92.3% (CI: 88.8-100). The recurrence rate was only 6.25%, and no patients were nonresponders to the treatment. CONCLUSIONS: The application of intravesical ozone was effective in the treatment of patients with IC/BPS who were nonresponders to conventional therapy, showing a progressive and safe effect, at least in the short term.

Cardiopulmonary and hematological effects of infrared LED photobiomodulation in the treatment of SARS-COV2.

BACKGROUND: COVID-19 disease is caused by SARS-CoV-2 which can trigger acute respiratory syndrome, which presents with dense alveolar and interstitial infiltrates and pulmonary edema, causing severe hypoxemia and significant alteration to pulmonary mechanics with reduced pulmonary compliance. The photobiomodulation technique alters cellular and molecular metabolism, showing promising results regarding the reduction of acute pulmonary inflammation. OBJECTIVE: To compare the photomodulation technique using near-infrared LED to conventional respiratory physiotherapy treatment in patients with COVID-19 in reversing acute conditions, reducing hospitalization time, and decreasing the need for oxygen therapy. METHODOLOGY: The cohort was comprised of 30 patients undergoing COVID-19 treatment who were divided and allocated into two equal groups randomly: the LED group (LED), treated with infrared LED at 940 nm and conventional therapy, and the control group (CON), who received conventional treatment (antibiotic therapy for preventing superimposed bacterial infections, and physiotherapy) with LED irradiation off. Phototherapy used a vest with an array of 300 LEDs (940 nm) mounted on a 36 cm × 58 cm area and positioned in the patient's anterior thoracic and abdominal regions. The total power was 6 W, with 15 min irradiation time. Cardiopulmonary functions and blood count were monitored before and after treatment. The patients were treated daily for 7 days. Statistical analysis was conducted using a two-tailed unpaired Student's t-test at a significance level of α = 0.05. RESULTS: Post-treatment, the LED group showed a reduction in hospital discharge time and a statistically significant improvement for the following cardiopulmonary functions: Partial Oxygen Saturation, Tidal Volume, Maximum Inspiratory, and Expiratory Pressures, Respiratory Frequency, Heart Rate, and Systolic Blood Pressure (p < 0.05). Regarding blood count, it was observed that post-treatment, the LED group presented with significant differences in the count of leukocytes, neutrophils, and lymphocytes. CONCLUSION: Photobiomodulation therapy can be used as a complement to conventional treatment of COVID-19, promoting the improvement of cardiopulmonary functions, and minimization of respiratory symptoms.

Biochemical Analysis of Urine Samples from Diabetic and Hypertensive Patients without Renal Dysfunction Using Spectrophotometry and Raman Spectroscopy Techniques Aiming Classification and Diagnosis.

The purpose of this study was to perform a comparative biochemical analysis between conventional spectrophotometry and Raman spectroscopy, techniques used for diagnoses, on the urine of healthy (CT) and diabetic and hypertensive patients (DM&HBP). Urine from 40 subjects (20 in the CT group and 20 in the DM&HBP group) was examined in a dispersive Raman spectrometer (an 830 nm excitation and a 350 mW power). The mean Raman spectra between both groups showed a significant difference in peaks of glucose; exploratory analysis by principal component analysis (PCA) identified spectral differences between the groups, with higher peaks of glucose and proteins in the DM&HBP group. A partial least squares (PLS) regression model estimated by the Raman data indicated the concentrations of urea, creatinine, glucose, phosphate, and total protein; creatinine and glucose were the biomarkers that presented the best correlation coefficient (r) between the two techniques analyzed (r = 0.68 and r = 0.98, respectively), both with eight latent variables (LVs) and a root mean square error of cross-validation (RMSecv) of 3.6 and 5.1 mmol/L (41 and 92 mg/dL), respectively. Discriminant analysis (PLS-DA) using the entire Raman spectra was able to differentiate the samples of the groups in the study, with a higher accuracy (81.5%) compared to the linear discriminant analysis (LDA) models using the concentration values of the spectrometric analysis (60.0%) and the concentrations predicted by the PLS regression (69.8%). Results indicated that spectral models based on PLS applied to Raman spectra may be used to distinguish subjects with diabetes and blood hypertension from healthy ones in urinalysis aimed at population screening.

Analysis of pain relief and functional recovery in patients with rotator cuff tendinopathy through therapeutic ultrasound and photobiomodulation therapy: a comparative study.

This study aimed to compare shoulder tendinopathy treatment with therapeutic ultrasound combined with LED photobiomodulation therapy using LED-infrared (850 nm) or LED-red (640 nm). The study assessed 75 patients, aged 45 to 70 years, distributed into five experimental groups (15 patients each): therapeutic ultrasound (US), infrared light irradiation (IR), visible red light irradiation (VR), infrared light and ultrasound combined (IR-US), and red light in conjunction with ultrasound (VR-US). The ultrasound parameters are 1 MHz, 0.5 W/cm2 (SATA), and 100 Hz repetition rate, applied for 4 min each session. LED irradiation protocols were as follows: 3 points, 7.5 J per point, IR-LED 750 mW, 10 s, VR-LED 250 mW, 30 s. LED irradiation is followed by ultrasound in the combined therapies. The efficiency of the five therapies was evaluated assessing 12 parameters: quality of life (Health Assessment Questionnaire, HAQ), pain intensity (Visual Analog Scale, VAS), articular amplitude of shoulder movement (flexion, extension, abduction, adduction, medial rotation, lateral rotation), muscle strength (abduction, lateral rotation), and electromyography (lateral rotation, abduction). Treatments comprised 12 sessions for 4 weeks. Intra-group analysis showed that the five therapies significantly improved the recovery of all parameters after treatment. Regarding the comparison of irradiated therapies and ultrasound, statistical analysis showed that IR-US was a better treatment than US for all 12 parameters. IR treatment exceeded US on 9 items, whereas that VR and VR-US therapies exceeded US in 7 and 10 parameters, respectively (p < 0.05). Because of that, IR-US shows to be the best treatment for rotator cuff tendinopathy. In conclusion, improvements in quality of life, pain intensity relief, shoulder amplitude motion, and muscle strength force obtained with ultrasound therapy are enhanced by adding infrared LED irradiation to ultrasound for patients suffering from rotator cuff tendinopathy. This study was registered with the Brazilian Registry of Clinical Trials (ReBEC) under Universal Trial Number (UTN) U1111-1219-3594 (2018/22/08).

Analytical performance of Raman spectroscopy in assaying biochemical components in human serum.

Chronic non-infectious diseases are important to research as they are the main causes of death in Brazil and worldwide. One very important chronic non-infectious disease is cardiovascular disease, whose risk factors (diabetes, dyslipidemia, and renal failure) can be detected through assessments of serum biochemical components. The objective of this study was to evaluate the analytical performance of Raman spectroscopy for analysis of lipid profile (total cholesterol, triglycerides, and HDL cholesterol), non-protein nitrogenous compounds (urea and creatinine), and glucose in 242 human serum samples. Models to discriminate and quantify the samples were developed using the predicted concentration by quantitative regression model based on partial least squares (PLS). The analytical error for the "leave-one-out" cross-validation based on the predicted PLS concentration was 10.5 mg/dL for total cholesterol, 21.4 mg/dL for triglyceride, 13.0 mg/dL for HDL cholesterol, 4.9 mg/dL for urea, 0.21 mg/dL for creatinine, and 15.4 mg/dL for glucose. The Kappa coefficient indicate very good agreement for cholesterol (0.83), good for triglyceride (0.77), urea (0.70) and creatinine (0.66), and fair for HDL cholesterol (0.38) and glucose (0.30). The results of the analytical performance demonstrated that Raman spectroscopy can be considered an important methodology to screen the population, especially for serum triglycerides and cholesterol.

Systemic Effects of Photobiomodulation on Blood Components in the Treatment of Community-Acquired Pneumonia.

Background: The analysis of the complete blood count (CBC) of patients with community-acquired pneumonia (CAP) is an essential practice both for diagnosing the disease and for evaluating the patient's clinical evolution. It is proposed in the present study to analyze the hematological alterations resulting from photobiostimulation using near-infrared light-emitting diodes (LEDs) in patients with CAP. Methods: This was a clinical, prospective, blinded, and descriptive longitudinal study that involved 21 patients undergoing CAP treatment who were divided into two groups: LED, 11 patients who were treated with infrared LED and conventional treatment; and CON (control), 10 patients who received only conventional treatment (antibiotic therapy and physiotherapy). Physiotherapy was applied before LED irradiation in the LED group. The patients' CBCs were obtained before and after treatment, and erythrocyte counts, hemoglobin and hematocrit concentrations, and leukocyte and platelet counts were assessed. The phototherapy was performed with a vest with an array of 300 LEDs (940 nm) mounted on an area of 36 × 58 cm and positioned in the patient's anterior thoracic and abdominal regions. The total power was 6 W, with 15 min of irradiation time. The patients were treated daily for seven consecutive days. Statistical analyses of the intra- and intergroups of CBC data were done using Student's t-test and one-way ANOVA (analysis of variance), respectively, both at the significance level of α = 0.05. Results: There was a statistically significant recovery difference after treatment in the LED group compared with the CON group for erythrocytes, hemoglobin, leukocytes, segmented and band neutrophils, lymphocytes, and monocytes (p < 0.05). The greatest differences between the LED and CON groups were lymphocyte count reduction (60% vs. 16%), erythrocyte increase (86% vs. 35%), and leukocyte reduction (28% vs. 15%). Conclusions: The hematologic components of CAP patients recovered their normal values faster with conventional treatment associated with infrared LED therapy, thus indicating greater treatment efficiency when compared with the conventional therapy. This study was registered with the Brazilian Registry of Clinical Trials (ReBeC) under Universal Trial Number (UTN) U1111-1229-1296 (2019/06/05).

Association of Ang-(1-7) and des-Arg9BK as new biomarkers of obesity and cardiometabolic risk factors in adolescents.

Children with obesity have a high risk of developing cardiovascular disease and hypertension, which is associated with the renin-angiotensin system (RAS) activation and kallikrein-kinin system (KKS) inactivation. Although recent studies have identified several peptide-based biomarkers for obesity, circulating peptides from the RAS and KKS in adolescents with obesity have not been described. The aim of this study was to examine circulating levels of RAS and KKS peptides in adolescents with obesity to investigate the turnover of these peptides and their relationship to metabolic disorders resulting from weight gain. The subjects (n = 104) were divided into normal weight (NW), overweight (OW), obese (OB), and morbidly obese (MO) groups. Anthropometric profiles were created by measuring height, weight, blood pressure, and skinfolds. Plasma levels of Ang I, II, (1-7), BK, and des-Arg9BK were quantified by high-performance liquid chromatography. The levels were as follows: Ang-(1-7)-MO 58.3 ± 50, OB 223.2 ± 150, OW 318.6 ± 190, NW 479.1 ± 160 pmol/mL, and Bradykinin (BK)-MO 367.6 ± 103, OB 253.8 ± 130, OW 484 ± 279, NW 874.9 ± 385 pmol/mL. Ang-(1-7) correlated inversely with weight, body mass index, leptin, diastolic blood pressure, and systolic blood pressure. BK and Ang-(1-7) levels correlated inversely with skinfolds, waist-hip ratio (WHR), leptin, and arm circumference. BK levels correlated with adiponectin and Ang-(1-7) levels. Plasma Ang I levels were higher in the MO and OB groups than in the NW group, but plasma Ang II levels were similar in all groups. We suggest that Ang-(1-7) and des-Arg9BK metabolites are novel biomarkers of childhood obesity that are important for determining treatment strategies.

Photobiomodulation: Shining Light on COVID-19.

Objective: To evaluate the hypothesis that light could reduce the lethality of COVID-19. Methods: Most models for projections of the spread and lethality of COVID-19 take into account the ambient temperature, neglecting light. Recent advances in understanding the mechanism of action of COVID-19 have shown that it causes a systemic infection that significantly affects the hematopoietic system and hemostasis, factors extremely dependent of light, mainly in the region of visible and infrared radiation. Results: In the COVID-19 patients hemoglobin is decreasing and protoporphyrin is increasing, generating an extremely harmful accumulation of iron ions in the bloodstream, which are able to induce an intense inflammatory process in the body with a consequent increase in C-reactive protein and albumin. Observing the unsaturation characteristics of the cyclic porphyrin ring allows it to absorb and emit radiation mainly in the visible region. This characteristic can represent an important differential to change this process in the event of an imbalance in this system, through the photobiomodulation to increase the production of adenosine triphosphate (ATP) using red and near-infrared radiation (R-NIR) and vitamin D using ultraviolet B (UVB) radiation. These two compounds have the primary role of activating the defense mechanisms of the immune system, enabling greater resistance of the individual against the attack by the virus. According to the theory of electron excitation in photosensitive molecules, similar to hemoglobin heme, after the photon absorption there would be an increase in the stability of the iron ion bond with the center of the pyrrole ring, preventing the losses of heme function oxygen transport (HbO2). The light is also absorbed by cytochrome c oxidase in the R-NIR region, with a consequent increase in electron transport, regulating enzyme activity and resulting in a significant increase of oxygen rate consumption by mitochondria, increasing ATP production. Conclusions: The most favorable range of optical radiation to operate in this system is between R-NIR region, in which cytochrome c oxidase and porphyrin present absorption peaks centered at 640 nm and HbO2 with absorption peak centered at 900 nm. Based on the mechanisms described earlier, our hypothesis is that light could reduce the lethality of COVID-19.

Diagnosing sickle cell disease and iron deficiency anemia in human blood by Raman spectroscopy.

This work proposed the diagnosis of iron deficiency anemia (IDA) and sickle cell disease (SCD) in human blood caused by iron deficiency and hemoglobin S (HbS), which are among the most common anemias, by means of Raman spectroscopy. Whole blood samples from patients diagnosed with IDA and HbS, as well as from normal subjects (HbA), were obtained and submitted to Raman spectroscopy (830 nm, 150 mW, 400-1800 cm-1 spectral range, 4 cm-1 resolution). Difference spectra of IDA-HbA showed spectral features of hemoglobin with less intensity in the IDA, whereas the difference spectra of SCD-HbA showed spectral features of deoxyhemoglobin increased and of oxyhemoglobin decreased in SCD. An exploratory analysis by principal components analysis (PCA) showed that the peaks referred to oxy- and deoxyhemoglobin markedly differentiated SCD and HbA, as well as the increased amount of hemoglobin features in the SCD group, suggesting increased erythropoiesis. The IDA group showed hemoglobin features with lower intensities as well as peaks referred to the iron bonding to the porphyrin ring with reduced intensities when compared to the HbA. Discriminant analysis based on partial least squares (PLS-DA) and PCA (PCA-DA) showed that the IDA and SCD anemias could be discriminated from the HbA spectra with 95.0% and 93.8% of accuracy, for the PLS and PCA respectively, with sensitivity/specificity of 93.8%/95.7% for the PLS-DA model. The iron depletion and the sickling of erythrocytes could be identified by Raman spectroscopy and a spectral model based on PLS accurately discriminated these IDA and SCD samples from the normal HbA.

Comparative analysis of the effects of ozone and ultrasound on Streptococcus mutans

Streptococcus mutans is one of the principal pathogens of the human oral habitat, being one of the principal etiological agents of carious lesions. Ozone is a powerful oxidant, it has the ability to inactivate microorganisms in general, and ultrasound is an acoustic system generated through a piezoelectric crystal that also presents microbicidal effects. In the present study, a comparative analysis was made of the damage caused to Streptococcus mutans in vitro by ultrasound and ozone, through scanning electron microscopy (SEM) and atomic force microscopy (AF) analysis. In addition, flow cytometry was used to determine microbial viability and the formation of Reactive Oxygen Species (ROS) after the application of different techniques. The data obtained by means of micro- scopic analysis reveal that both ozone and ultrasound produce morphological alterations in bacteria, which become rod-shaped organisms. In addition to this deformation, on the microbial surface it was possible to identify crater-like impressions. In contrast, the irregularity of protuber- ances on the surface of the microbial wall was only detected when ozone was employed. Regarding the formation of ROS, it was observed that that ozone induces a significant growth (p < .05) of these molecules, while ultrasound does not present this effect. Ozone and ultrasound present micro- bicidal effects, however, ozone is more efficient.

Analysis of damage on the Streptococcus mutans immersed in ozonated water: preliminary study for application as mouth rinse

Ozonated water has been demonstrated to induce significant results in terms of the elimination ofmicroorganisms. The present study assessed the damage toStreptococcusmutansafter exposureto ozonated water; the ozone generator was adjusted to provide an outlet concentration of60 mg/L, the samples were submitted to different ozonation times 1, 2, 4, 6, and 10 mi. Scanningelectron microscopy and atomic force images were obtained to identify damage to the bacteria,followed by reactive oxygen species (ROS) evaluation and microbial viability. The results showed asignificant reduction in viability and the images evidenced the generation of gaps on themicrobial wall and surface layer alterations. Ozone can induce significant damage toS.mutans,thus suggesting that the use of ozonated water to prevent carious lesion formation is extremelypromising.

Analysis of damage on the Streptococcus mutans immersed in ozonated water: preliminary study for application as mouth rinse

Ozonated water has been demonstrated to induce significant results in terms of the elimination ofmicroorganisms. The present study assessed the damage toStreptococcusmutansafter exposureto ozonated water; the ozone generator was adjusted to provide an outlet concentration of60 mg/L, the samples were submitted to different ozonation times 1, 2, 4, 6, and 10 mi. Scanningelectron microscopy and atomic force images were obtained to identify damage to the bacteria,followed by reactive oxygen species (ROS) evaluation and microbial viability. The results showed asignificant reduction in viability and the images evidenced the generation of gaps on themicrobial wall and surface layer alterations. Ozone can induce significant damage toS.mutans,thus suggesting that the use of ozonated water to prevent carious lesion formation is extremelypromising.

Influence of neural mobilization in the sympathetic slump position on the behavior of the autonomic nervous system

Abstract Introduction The neural mobilization technique in the sympathetic slump position (NMSS) was based on the slump test, whose purpose was to directly influence the sympathetic trunk and thus provide greater analgesia by sympathetic activation and treat pain syndromes caused by peripheral sympathetic changes. Therefore, as the autonomic nervous system (ANS) is responsible for extrinsic regulation of the cardiovascular system through sympathetic and parasympathetic action, the aim of this study was to investigate the influence of the NMSS technique on the systolic and diastolic blood pressure and heart rate variability in athlete and non-athlete men. Methods Twenty-eight subjects performed the procedure that was divided into three phases: rest; intervention and recovery, lasting 4 minutes and 30 seconds each, totaling a 13-minute and 30 seconds collection time. Results The results showed that the NMSS technique significantly influences the action/activity of the ANS, as there was predominant sympathetic activation during the application of the technique, which was observed by the increase in systolic blood pressure, low frequency (LF), LF/HF ratio and decreased values of high frequency (HF). Conclusion It may be concluded that the neural mobilization technique on the sympathetic slump (NMSS) significantly influences the ANS action/activity. Among the groups there was no statistically significant difference in heart rate variability. It is worth noting that patients with cardiovascular disorders may be at risk if the NMSS technique is applied, since there was an increase in SBP and sympathetic activation during its application in both groups.

LED phototherapy in full-thickness burns induced by CO2 laser in rats skin.

Many studies have been conducted on the treatment of burns because they are important in morbidity and mortality. These studies are mainly focused on improving care and quality of life of patients. The aim of this study was evaluate the LED phototherapy effects in rats skin full-thickness burns induced by CO2 laser. The animals were divided in NT group that did not received any treatment and LED group that received LED irradiation at 685 nm, 220 mW, and 4.5 J/cm2 during 40 s by burned area. Biopsies were obtained after 7, 14, and 21 days of treatment and submitted to histological and immunohistochemical analysis. The LED phototherapy shows anti-inflammatory effects, improves angiogenesis, and stimulates the migration and proliferation of fibroblasts. The T CD8+ lymphocytes were more common in burned areas compared to T CD4+ lymphocytes since statistically significant differences were observed in the LED group compared to the NT group after 7 days of treatment. These results showed that LED phototherapy performs positive influence in full-thickness burns repair from the healing process modulated by cellular immune response. The obtained results allowed inferring that burns exhibit a characteristic cell immune response and this cannot be extrapolated to other wounds such as incision and wounds induced by punch, among others.

Use of photodynamic therapy in the treatment of bovine subclinical mastitis.

BACKGROUND: Bovine mastitis is a disease that causes a severe drawback in dairy production. Conventional treatments with antibiotic could leave antibiotic residues in the milk. The aim of this study was to evaluate the effect of photodynamic therapy in the treatment of bovine subclinical mastitis to develop an in vivo therapeutic protocol that could be used in routine farm practice, favoring the early return to production. METHODS: Forty cows with subclinical mastitis (n = 40) were divided into 4 groups (control, photodynamic therapy - PDT, light irradiation - LED, and photosensitizer - PS). Control group received no treatment, PDT group received application of 1.0 mL of 2.5% toluidine blue photosensitizer followed by LED irradiation at λ = 635 nm, the LED group was treated with LED irradiation alone, and the PS group received only 2.5% toluidine blue dye. LED irradiation was applied to the mammary gland by means of an acrylic light guide coupled to the LED equipment. The PDT and LED groups were irradiated with 200 J/cm2 at three different positions inside the mammary gland. Milk samples were collected at 0 h, 12 h, 24 h after treatment for microbial identification and total bacterial count. RESULTS: The treatment of the PDT group showed significant difference p < 0.05, characterizing the efficiency of this technique with the reduction of the microorganisms Streptococcus dysgalactiae and coagulase-negative Staphylococcus. CONCLUSION: Photodynamic therapy was effective when applied in vivo for subclinical bovine mastitis. There was no need to separate the animal from production.

Raman spectroscopy applied to identify metabolites in urine of physically active subjects.

Raman spectroscopy is a rapid and non-destructive technique suitable for biological fluids analysis. In this work, dispersive Raman spectroscopy has been employed as a rapid and nondestructive technique to detect the metabolites in urine of physically active subjects before and after vigorous 30min pedaling or running compared to sedentary subjects. For so, urine samples from 9 subjects were obtained before and immediately after physical activities and submitted to Raman spectroscopy (830nm excitation, 250mW laser power, 20s integration time) and compared to urine from 5 sedentary subjects. The Raman spectra of urine from sedentary showed peaks related to urea, creatinine, ketone bodies, phosphate and other nitrogenous compounds. These metabolic biomarkers presented peaks with different intensities in the urine of physically active individuals after exercises compared to before, measured by the intensity of selected peaks the Raman spectra, which means different concentrations after training. These peaks presented different intensity values for each subject before physical activity, also behaving differently compared to the post-training: some subjects presented increase while others decrease the intensity. Raman spectroscopy may allow the development of a rapid and non-destructive test for metabolic evaluation of the physical training in active and trained subjects using urine samples, allowing nutrition adjustment with the sport's performance.

Discrimination model applied to urinalysis of patients with diabetes and hypertension aiming at diagnosis of chronic kidney disease by Raman spectroscopy.

Higher blood pressure level and poor glycemic control in diabetic patients are considered progression factors that cause faster decline in kidney functions leading to kidney damage. The present study aimed to develop a quantification model of biomarkers creatinine, urea, and glucose by means of selected peaks of these compounds, measured by Raman spectroscopy, and to estimate the concentration of these analytes in the urine of normal subjects (G_N), diabetic patients with hypertension (G_WOL) patients with chronic renal failure doing dialysis (G_D). Raman peak intensities at 680 cm-1 (creatinine), 1004 cm-1 (urea), and 1128 cm-1 (glucose) from normal, diabetic, and hypertensive and doing dialysis patients, obtained with a dispersive 830 nm Raman spectrometer, were estimated through Origin software. Spectra of creatinine, urea, and glucose diluted in water were also obtained, and the same peaks were evaluated. A discrimination model based on Mahalanobis distance was developed. It was possible to determine the concentration of creatinine, urea, and glucose by means of the Raman peaks of the selected biomarkers in the urine of the groups G_N, G_WOL, and G_D (r = 0.9). It was shown that the groups G_WOL and G_D had lower creatinine and urea concentrations than the group G_N (p < 0.05). The classification model based on Mahalanobis distance applied to the concentrations of creatinine, urea, and glucose presented a correct classification of 89% for G_N, 86% for G_WOL, and 79% for G_D. It was possible to obtain quantitative information regarding important biomarkers in urine for the assessment of renal impairment in patients with diabetes and hypertension, and this information can be correlated with clinical criteria for the diagnosis of chronic kidney disease.

Quantifying glucose and lipid components in human serum by Raman spectroscopy and multivariate statistics.

Raman spectroscopy has been employed in the quantitative analysis of biochemical components in human serum. This study aimed to develop a spectral model to estimate the concentration of glucose and lipid fractions in human serum, thus evaluating the feasibility of Raman spectroscopy technique for diagnostic purposes. A total of 44 samples of blood serum were collected from volunteers submitted to routine blood biochemical assay analysis. The biochemical concentrations of glucose, triglycerides, cholesterol, and high-density and low-density lipoproteins (HDL and LDL) were obtained by colorimetric method. Serum samples (200 µL) were submitted to Raman spectroscopy (830 nm, 250 mW, 50-s accumulation). The spectra of sera present peaks related to the main constituents, particularly proteins and lipids. A quantitative model based on partial least squares (PLS) regression has been developed to estimate the concentration of these compounds, taking the biochemical concentrations assayed by the colorimetric method as sample's actual concentrations. The PLS model based on leave-one-out cross-validation approach estimated the concentration of triglycerides and cholesterol with r = 0.98 and 0.96, and root mean square error of 35.4 and 15.9 mg/dL, respectively. For the other biochemicals, the r was ranging from 0.75 to 0.86. These results evidenced the possibility of performing biochemical assay in blood serum samples by Raman spectroscopy and PLS regression and may be employed as a means of diagnosis in routine clinical analysis.

Estimating the concentration of urea and creatinine in the human serum of normal and dialysis patients through Raman spectroscopy.

Urea and creatinine are commonly used as biomarkers of renal function. Abnormal concentrations of these biomarkers are indicative of pathological processes such as renal failure. This study aimed to develop a model based on Raman spectroscopy to estimate the concentration values of urea and creatinine in human serum. Blood sera from 55 clinically normal subjects and 47 patients with chronic kidney disease undergoing dialysis were collected, and concentrations of urea and creatinine were determined by spectrophotometric methods. A Raman spectrum was obtained with a high-resolution dispersive Raman spectrometer (830 nm). A spectral model was developed based on partial least squares (PLS), where the concentrations of urea and creatinine were correlated with the Raman features. Principal components analysis (PCA) was used to discriminate dialysis patients from normal subjects. The PLS model showed r = 0.97 and r = 0.93 for urea and creatinine, respectively. The root mean square errors of cross-validation (RMSECV) for the model were 17.6 and 1.94 mg/dL, respectively. PCA showed high discrimination between dialysis and normality (95 % accuracy). The Raman technique was able to determine the concentrations with low error and to discriminate dialysis from normal subjects, consistent with a rapid and low-cost test.