237 research outputs found
The glycemic elemental profile of trichosanthes dioica: a LIBS-based study
The scientific evaluation of the antidiabetic efficacy of aqueous extract of Trichosanthes dioica fruits on streptozotocin-induced diabetic rats is being presented. The graded doses of the extract, viz., 500, 750, 1,000, and 1,250 mg/kg body weight (bw), were administered orally, and it was observed that the blood glucose concentration decreased in a dose-dependent manner. The dose of 1,000 mg/kg bw showed the maximum fall of 23.8% and 19.1% in blood glucose level (BGL) during fasting BGL and glucose tolerance test (GTT) studies, respectively, of nondiabetic rats. Whereas in the case of subdiabetic and mild diabetic models, the same dose showed reduction in BGL of 22.0% and 31.4% during GTT. The study also involves the first use of laser-induced breakdown spectroscopy as a sensitive analytical tool to detect the elemental profile responsible for the antidiabetic activity of aqueous extract of T. dioica fruits that exhibits the antidiabetic activity. High intensities of Ca, Mg, and Fe indicate large concentrations of these elements in the extract, since according to Boltzmann’s distribution law, intensities are directly proportional to concentrations. The higher concentrations of these glycemic elements, viz. Ca, Mg, and Fe, are responsible for the antidiabetic potential of T. dioica as well as other plant already reported by our research group
Application of LIBS in Detection of Antihyperglycemic Trace Elements in Momordica charantia
The present study exploits the information based on concentration of trace elements and minerals in understanding the role/mechanism of action of freeze-dried fruit powder suspended in distilled water of Momordica charantia (family: Cucurbitaceae) in diabetes treatment. Laser-induced break down spectroscopy (LIBS) spectra of plant product was recorded under optimized experimental conditions and analyzed. Several atomic lines such as Na, K, Mg, Ca, Fe, Al, etc. have been observed in the LIBS spectra of the above plant product. The concentrations of these minerals are determined by using calibration-free LIBS method. Correlation between the concentration of these elements/minerals and their defined role in diabetes management was studied in normal as well as diabetic animal model
LIBS-Based Detection of Antioxidant Elements in Seeds of Emblica officinalis
The aim of the study was to determine the effect of the elements of the extract of seed from Emblica officinalis on antioxidant enzymes and osmotic fragility of erythrocytes membrane in normal as well as streptozotocin-induced severely diabetic albino Wister rats. The results revealed that the untreated diabetic rats exhibited increase in oxidative stress as indicated by significantly diminished activities of free radical scavenging enzymes such as catalase (CAT) and superoxide dismutase (SOD) by 37.5% (p
Correlation of trans-Lycopene Measurements by the HPLC Method with the Optothermal and Photoacoustic Signals and the Color Readings of Fresh Tomato Homogenates
The trans-lycopene content of fresh tomato homogenates was assessed by means of the laser photoacoustic spectroscopy, the laser optothermal window, micro-Raman spectroscopy, and colorimetry; none of these methods require the extraction from the product matrix prior to the analysis. The wet chemistry method (high-performance liquid chromatography) was used as the absolute quantitative method. Analytical figures of merit for all methods were compared statistically; best linear correlation was achieved for the chromaticity index a* and chroma C*
Cryptococcus neoformans ex vivo capsule size is associated with intracranial pressure and host immune response in HIV-associated cryptococcal meningitis
<p>Background. The Cryptococcus neoformans polysaccharide capsule is a well-characterised virulence factor with immunomodulatory properties. The organism and/or shed capsule is postulated to raise intracranial pressure(ICP) in cryptococcal meningitis(CM) by mechanical obstruction of cerebrospinal fluid(CSF) outflow. Little is known regarding capsule phenotype in human cryptococcosis. We investigated the relationship of ex vivo CSF capsular phenotype with ICP and CSF immune response, as well as in vitro phenotype.</p>
<p>Methods. 134 HIV-infected Ugandan adults with CM had serial lumbar punctures with measurement of CSF opening pressures, quantitative cultures, ex vivo capsule size and shedding, viscosity, and CSF cytokines. 108 had complete data. Induced capsular size and shedding were measured in vitro for 48 C. neoformans isolates.</p>
<p>Results. Cryptococcal strains producing larger ex vivo capsules in the baseline(pre-treatment) CSF correlated with higher ICP(P=.02), slower rate of fungal clearance(P=.02), and paucity of CSF inflammation, including decreased CSF white blood cell(WBC) count(P<.001), interleukin(IL)-4(P=.02), IL-6(P=.01), IL-7(P=.04), IL-8(P=.03), and interferon-gamma(P=.03). CSF capsule shedding did not correlate with ICP. On multivariable analysis, capsule size remained independently associated with ICP. Ex vivo capsular size and shedding did not correlate with that of the same isolates grown in vitro.</p>
<P>Conclusions. Cryptococcal capsule size ex vivo is an important contributor to virulence in human cryptococcal meningitis.</P>
Jednostavna i brza metoda određivanja udjela ukupnih karotenoida u liofiliziranoj marelici (Prunus armeniaca L.) pomoću refleksne kolorimetrije i fotoakustične spektroskopije
Photoacoustic spectroscopy (PAS) and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and high-performance liquid chromatography (HPLC). Best correlations were found between the total carotenoid (TC) content (obtained by VIS spectrophotometry: 1.2–3.4 mg per 100 g of fresh mass) and colorimetric index a* (a* represents the redness of the investigated sample), as well as either argon-ion laser- or xenon-lamp-based PAS. In all three cases linear correlations were comparable. However, according to the sensitivity and precision data, expressed via limit of detection (LOD) and measurement repeatability, the Xe-lamp-based PAS is a preferred approach, followed by colorimetric index a* and Ar-ion laser PAS. Both PAS methods exhibit practically the same Pearson\u27s correlation coefficient (R=0.987 and R=0.991) values. Nevertheless, residual sum of squares (RSS) and residual standard deviation of the linear regression (sy/x) differ markedly. For Xe-lamp-based PAS these parameters were much lower than in the case of Ar-ion laser PAS. Likewise, analysis imprecision amounted to relative standard deviation (RSD) of 1–3 % for Xe-lamp PAS and 2–6 % for Ar-ion laser PAS. On the other hand, as expected, the calibration sensitivity achieved for the PAS signal induced by an Ar-ion laser at 481 nm was substantially higher than that of a Xe-lamp at 470 nm. Nevertheless, according to much lower sy/x, the corresponding LOD for Xe-lamp PAS was still two times lower than that of Ar-ion-based laser PAS (0.59 vs. 1.10 mg per 100 g). Unlike this, Ar-ion laser PAS showed more favourable instrumental precision and standard error of the weighed mean when compared to the Xe-lamp PAS (0.1–0.6 and 0.1–0.3 % vs. 0.5–8.0 and 0.4–1.7 %, respectively). As far as colorimetric indices are concerned, only a* proved to be analytically useful; excellent R but rather modest RSS and sy/x resulted in LOD value of 0.70 mg per 100 g and acceptable analysis imprecision of up to 3 %. The outcome of this research provides sufficient amount of evidence that analytical methods such as reflectance colorimetry and PAS without the use of any chemicals are feasible for reliable quantification of total carotenoids in freeze-dried apricot homogenates.Fotoakustična spektroskopija (PAS) i refleksna kolorimetrija predložene su kao nove metode određivanja udjela ukupnih karotenoida u liofiliziranom prahu marelice. Rezultati dobiveni ispitivanjem sedam kultivara marelice ovim dvjema tehnikama uspoređeni su s onima dobivenim konvencionalnom vidljivom spektrofotometrijom i tekućinskom kromatografijom visoke djelotvornosti (HPLC). Najbolje su korelacije dobivene između udjela ukupnih karotenoida (vidljivom je spektrofotometrijom utvrđen udjel od 1,2 do 3,4 mg u 100 g svježe mase) i kolorimetrijskog indeksa a* (parametar crvenila ispitanog uzorka), te metodom PAS s argonskim laserom ili ksenonskom lampom kao izvorom zračenja. U sva su tri slučaja dobivene usporedljive linearne korelacije. Međutim, s obzirom na osjetljivost i preciznost rezultata izraženih pomoću granice detekcije i ponovljivosti mjerenja, najboljom se pokazala metoda PAS sa ksenonskom lampom, zatim kolorimetrijski indeks a* i naposljetku metoda PAS s argonskim laserom. Obje su metode PAS imale podjednake Pearsonove koeficijente korelacije (R=0,987 i R=0,991). Ipak, rezidualna suma kvadrata (RSS) i rezidualna standardna devijacija linijske regresije (sy/x) značajno su se razlikovale. Za metodu PAS sa ksenonskom lampom ovi su parametri bili znatno manji nego za metodu PAS s argonskim laserom. Također, nepreciznost je metode izražena pomoću relativne standardne devijacije (RSD) bila od 1 do 3 % za metodu PAS sa ksenonskom lampom i od 2 do 6 % za metodu PAS s argonskim laserom. S druge je pak strane, kao što je i bilo očekivano, kalibracijska osjetljivost postignuta za signal PAS induciran argonskim laserom pri 481 nm bila znatno niža od one dobivene ksenonskom lampom pri 470 nm. Ipak, zahvaljujući bitno nižoj vrijednosti sy/x, granica detekcije metode PAS sa ksenonskom lampom (0,59 mg u 100 g) bila je dvostruko manja od one metode PAS s argonskim laserom (1,10 mg u 100 g). Nasuprot tomu, metoda PAS s argonskim laserom imala je bolju preciznost instrumenta (nepreciznost mjerenja od samo 0,1-0,6 %) i standardnu pogrešku ponderirane sredine (0,1-0,3 %), u usporedbi s metodom PAS sa ksenonskom lampom (0,5-8,0 % odnosno 0,4-1,7 %). Među kolorimetrijskim indeksima samo je indeks a* bio koristan za analizu; odlične vrijednosti R, ali skromne vrijednosti RSS i sy/x rezultirale su granicom detekcije od 0,70 mg u 100 g i prihvatljivom nepreciznošću mjerenja od najviše 3 %. Rezultati ovog istraživanja pokazuju da se analitičke tehnike, poput refleksne kolorimetrije i fotoakustične spektroskopije mogu primijeniti za pouzdano određivanje udjela ukupnih karotenoida u liofiliziranim homogenatima marelice, i to bez uporabe reagenasa
Jednostavna i brza metoda određivanja udjela ukupnih karotenoida u liofiliziranoj marelici (Prunus armeniaca L.) pomoću refleksne kolorimetrije i fotoakustične spektroskopije
Photoacoustic spectroscopy (PAS) and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and high-performance liquid chromatography (HPLC). Best correlations were found between the total carotenoid (TC) content (obtained by VIS spectrophotometry: 1.2–3.4 mg per 100 g of fresh mass) and colorimetric index a* (a* represents the redness of the investigated sample), as well as either argon-ion laser- or xenon-lamp-based PAS. In all three cases linear correlations were comparable. However, according to the sensitivity and precision data, expressed via limit of detection (LOD) and measurement repeatability, the Xe-lamp-based PAS is a preferred approach, followed by colorimetric index a* and Ar-ion laser PAS. Both PAS methods exhibit practically the same Pearson\u27s correlation coefficient (R=0.987 and R=0.991) values. Nevertheless, residual sum of squares (RSS) and residual standard deviation of the linear regression (sy/x) differ markedly. For Xe-lamp-based PAS these parameters were much lower than in the case of Ar-ion laser PAS. Likewise, analysis imprecision amounted to relative standard deviation (RSD) of 1–3 % for Xe-lamp PAS and 2–6 % for Ar-ion laser PAS. On the other hand, as expected, the calibration sensitivity achieved for the PAS signal induced by an Ar-ion laser at 481 nm was substantially higher than that of a Xe-lamp at 470 nm. Nevertheless, according to much lower sy/x, the corresponding LOD for Xe-lamp PAS was still two times lower than that of Ar-ion-based laser PAS (0.59 vs. 1.10 mg per 100 g). Unlike this, Ar-ion laser PAS showed more favourable instrumental precision and standard error of the weighed mean when compared to the Xe-lamp PAS (0.1–0.6 and 0.1–0.3 % vs. 0.5–8.0 and 0.4–1.7 %, respectively). As far as colorimetric indices are concerned, only a* proved to be analytically useful; excellent R but rather modest RSS and sy/x resulted in LOD value of 0.70 mg per 100 g and acceptable analysis imprecision of up to 3 %. The outcome of this research provides sufficient amount of evidence that analytical methods such as reflectance colorimetry and PAS without the use of any chemicals are feasible for reliable quantification of total carotenoids in freeze-dried apricot homogenates.Fotoakustična spektroskopija (PAS) i refleksna kolorimetrija predložene su kao nove metode određivanja udjela ukupnih karotenoida u liofiliziranom prahu marelice. Rezultati dobiveni ispitivanjem sedam kultivara marelice ovim dvjema tehnikama uspoređeni su s onima dobivenim konvencionalnom vidljivom spektrofotometrijom i tekućinskom kromatografijom visoke djelotvornosti (HPLC). Najbolje su korelacije dobivene između udjela ukupnih karotenoida (vidljivom je spektrofotometrijom utvrđen udjel od 1,2 do 3,4 mg u 100 g svježe mase) i kolorimetrijskog indeksa a* (parametar crvenila ispitanog uzorka), te metodom PAS s argonskim laserom ili ksenonskom lampom kao izvorom zračenja. U sva su tri slučaja dobivene usporedljive linearne korelacije. Međutim, s obzirom na osjetljivost i preciznost rezultata izraženih pomoću granice detekcije i ponovljivosti mjerenja, najboljom se pokazala metoda PAS sa ksenonskom lampom, zatim kolorimetrijski indeks a* i naposljetku metoda PAS s argonskim laserom. Obje su metode PAS imale podjednake Pearsonove koeficijente korelacije (R=0,987 i R=0,991). Ipak, rezidualna suma kvadrata (RSS) i rezidualna standardna devijacija linijske regresije (sy/x) značajno su se razlikovale. Za metodu PAS sa ksenonskom lampom ovi su parametri bili znatno manji nego za metodu PAS s argonskim laserom. Također, nepreciznost je metode izražena pomoću relativne standardne devijacije (RSD) bila od 1 do 3 % za metodu PAS sa ksenonskom lampom i od 2 do 6 % za metodu PAS s argonskim laserom. S druge je pak strane, kao što je i bilo očekivano, kalibracijska osjetljivost postignuta za signal PAS induciran argonskim laserom pri 481 nm bila znatno niža od one dobivene ksenonskom lampom pri 470 nm. Ipak, zahvaljujući bitno nižoj vrijednosti sy/x, granica detekcije metode PAS sa ksenonskom lampom (0,59 mg u 100 g) bila je dvostruko manja od one metode PAS s argonskim laserom (1,10 mg u 100 g). Nasuprot tomu, metoda PAS s argonskim laserom imala je bolju preciznost instrumenta (nepreciznost mjerenja od samo 0,1-0,6 %) i standardnu pogrešku ponderirane sredine (0,1-0,3 %), u usporedbi s metodom PAS sa ksenonskom lampom (0,5-8,0 % odnosno 0,4-1,7 %). Među kolorimetrijskim indeksima samo je indeks a* bio koristan za analizu; odlične vrijednosti R, ali skromne vrijednosti RSS i sy/x rezultirale su granicom detekcije od 0,70 mg u 100 g i prihvatljivom nepreciznošću mjerenja od najviše 3 %. Rezultati ovog istraživanja pokazuju da se analitičke tehnike, poput refleksne kolorimetrije i fotoakustične spektroskopije mogu primijeniti za pouzdano određivanje udjela ukupnih karotenoida u liofiliziranim homogenatima marelice, i to bez uporabe reagenasa
Genomic epidemiology of Cryptococcus yeasts identifies adaptation to environmental niches underpinning infection across an African HIV/AIDS cohort
Emerging infections caused by fungi have become a widely recognized global phenomenon and are causing an increasing burden of disease. Genomic techniques are providing new insights into the structure of fungal populations, revealing hitherto undescribed fine-scale adaptations to environments and hosts that govern their emergence as infections. Cryptococcal meningitis is a neglected tropical disease that is responsible for a large proportion of AIDS-related deaths across Africa; however, the ecological determinants that underlie a patient's risk of infection remain largely unexplored. Here, we use genome sequencing and ecological genomics to decipher the evolutionary ecology of the aetiological agents of cryptococcal meningitis, Cryptococcus neoformans and Cryptococcus gattii, across the central African country of Zambia. We show that the occurrence of these two pathogens is differentially associated with biotic (macroecological) and abiotic (physical) factors across two key African ecoregions, Central Miombo woodlands and Zambezi Mopane woodlands. We show that speciation of Cryptococcus has resulted in adaptation to occupy different ecological niches, with C. neoformans found to occupy Zambezi Mopane woodlands and C. gattii primarily recovered from Central Miombo woodlands. Genome sequencing shows that C. neoformans causes 95% of human infections in this region, of which over three-quarters belonged to the globalized lineage VNI. We show that VNI infections are largely associated with urbanized populations in Zambia. Conversely, the majority of C. neoformans isolates recovered in the environment belong to the genetically diverse African-endemic lineage VNB, and we show hitherto unmapped levels of genomic diversity within this lineage. Our results reveal the complex evolutionary ecology that underpins the reservoirs of infection for this, and likely other, deadly pathogenic fungi
A Prospective Longitudinal Study of the Clinical Outcomes from Cryptococcal Meningitis following Treatment Induction with 800 mg Oral Fluconazole in Blantyre, Malawi
Introduction: Cryptococcal meningitis is the most common neurological infection in HIV infected patients in Sub Saharan Africa, where gold standard treatment with intravenous amphotericin B and 5 flucytosine is often unavailable or difficult to administer. Fluconazole monotherapy is frequently recommended in national guidelines but is a fungistatic drug compromised by uncertainty over optimal dosing and a paucity of clinical end-point outcome data.
Methods: From July 2010 until March 2011, HIV infected adults with a first episode of cryptococcal meningitis were
recruited at Queen Elizabeth Central Hospital, Blantyre, Malawi. Patients were treated with oral fluconazole monotherapy 800 mg daily, as per national guidelines. ART was started at 4 weeks. Outcomes and factors associated with treatment failure were assessed 4, 10 and 52 weeks after fluconazole initiation.
Results: Sixty patients were recruited. 26/60 (43%) died by 4 weeks. 35/60 (58.0%) and 43/56 (77%) died or failed treatment by 10 or 52 weeks respectively. Reduced consciousness (Glasgow Coma Score ,14 of 15), moderate/severe neurological disability (modified Rankin Score .3 of 5) and confusion (Abbreviated Mental Test Score ,8 of 10) were all common at baseline and associated with death or treatment failure. ART prior to recruitment was not associated with better outcomes.
Conclusions: Mortality and treatment failure from cryptococcal meningitis following initiation of treatment with 800 mg oral fluconazole is unacceptably high. To improve outcomes, there is an urgent need for better therapeutic strategies and point-of-care diagnostics, allowing earlier diagnosis before development of neurological deficit
AIDS-Related Mycoses: Current Progress in the Field and Future Priorities.
Opportunistic fungal infections continue to take an unacceptably heavy toll on the most disadvantaged living with HIV-AIDS, and are a major driver for HIV-related deaths. At the second EMBO Workshop on AIDS-Related Mycoses, clinicians and scientists from around the world reported current progress and key priorities for improving outcomes from HIV-related mycoses
- …