Search Results (67)

Background: Pityriasis versicolor (PV) is a common superficial mycosis caused by Malassezia species. To describe the clinical and epidemiological characteristics of PV in Acapulco, Mexico, and to identify the associated Malassezia species using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). Methods: A cross-sectional study was conducted in 2024 at Acapulco General Hospital and a private dermatology clinic. Patients with clinically suspected PV and no recent antifungal or immunosuppressive treatment were enrolled. Skin scales were examined microscopically and cultured on modified Dixon agar. Isolates were identified using conventional methods and PCR-RFLP with HhaI and BstCI enzymes. Results: Sixty-nine patients were included; 68.1% were male, and the most affected age group was 11–20 years (34.8%). The hypochromic variant predominated (63.8%). PCR-RFLP identified M. globosa (33.3%) and M. furfur (31.9%) as the most frequent species, followed by M. restricta, M. sympodialis, and M. slooffiae. Species identification was unsuccessful in 11.6% of isolates. No statistically significant associations were found between clinical variants, gender, or species distribution. Conclusions: M. globosa and M. furfur were the predominant species in this tropical Mexican cohort. PCR-RFLP is a practical option for species-level identification, highlighting the diversity of Malassezia in PV. Full article

This work presents a detailed study of the coordination of Eu(III) with tartrate and oxalate ligands in aqueous solutions. The following techniques were employed: potentiometric titrations, 1D ¹H, ¹³C multinuclear NMR spectroscopy, 2D NMR experiments (COSY, HMQC, HMBC), and UV-Vis spectroscopy. Overall (cumulative) formation constants (logβ) were determined at ionic strengths of 0.1, 0.5, and 1.0, M KNO₃ over the temperature range 298–318 K. At 298 K, the oxalate complexes are significantly more stable (logβ = 7.63→15.70 as the ionic strength increases from 0.1 to 1.0 M) than the corresponding tartrate species (logβ = 5.11→8.87). Analysis of the temperature dependence of logβ shows that the Gibbs free energy change comprises both temperature-dependent terms and an approximately temperature-independent covalent contribution, the latter becoming strongly negative values in the tartrate system. The NMR data support a bidentate coordination mode involving deprotonated hydroxyl and carboxylate groups, whereas ¹⁷O NMR monitors the mechanism of water exchange within the Eu(III) hydration sphere. In the UV-Vis domain, a distinct blue shift in the absorption band is observed at 0.1 M KNO₃, while at 1.0 M KNO₃, the band shows a pronounced decrease in intensity, a hypochromic effect. This behavior can be attributed to increased structural distortion and a partial loss of coplanarity within the tartrate coordination environment. By contrast, the oxalate system behaves differently: the spectra, together with the thermodynamic data, support a more covalent Eu–O interaction, consistent with stabilization of Eu(III) by two dicarboxylate ligands adopting distinct coordination modes. Full article

Siderophores are low-molecular-weight chelating agents secreted by microorganisms under iron-limiting conditions, playing a crucial role in metal bioavailability and microbial survival. In this study, siderophores produced by Glutamicibacter sp. strain Al-Teq-24-F2, isolated from plant-associated samples, were characterized through a combination of spectroscopic and analytical methods. ESI-MS analysis of the crude extract revealed several abundant ions between 175 and 800 m/z, suggesting a mixture of secondary metabolites. After chromatographic purification, FT-IR and NMR analyses indicated the presence of amide, hydroxyl, and carboxylate functional groups. Integrating these data allowed for the proposal of a siderophore structure with a molecular weight of 438.25 Da. Thermogravimetric analysis showed thermal stability below 115 °C. During Fe (III) complexation, the zeta potential shifted from −21.15 mV to +42 mV, confirming strong interaction between the ligand and the metal. UV–Vis and fluorescence spectroscopy displayed characteristic bathochromic and hypochromic shifts, together with pronounced fluorescence quenching upon iron binding. These findings provide new insight into the structural and physicochemical properties of siderophores produced by Glutamicibacter sp. and highlight their potential applications in biosensing and metal chelation processes. Full article

The osmium(II) polypyridyl complex [Os(tpy)(pydppn)]²⁺ (tpy = 2,2′:6′,2″-terpyridine; pydppn = 3-(pyrid-2′-yl)-4,5,9,16-tetraaza-dibenzo[a,c]naphthacene) was synthesized and characterized to evaluate the effect of an extended planar π-system on photophysical properties and DNA interactions. This complex represents the π-expanded analog of the previously studied [Os(tpy)(pydppz)]²⁺ system. Electrochemical studies revealed a reversible Os(II)/Os(III) oxidation at +0.99 V vs. SCE and five ligand-centered reductions, generally less negative than those of the smaller pydppz analog, consistent with enhanced electron-accepting ability. In acetonitrile, the complex exhibits UV absorption bands at 328 and 473 nm and near-infrared emission at 840 nm, assigned to a long-lived ³MLCT state (τ = 110 ns, Φ = 0.02). Upon titration with calf-thymus DNA, [Os(tpy)(pydppn)]²⁺ shows a pronounced light-switch effect, hypochromism, red-shifted MLCT bands, induced circular dichroism, and an increase in DNA melting temperature (ΔT_m = 8.9 ± 0.5 °C), consistent with intercalative binding. Viscometric titrations further support intercalation, with a binding constant K_B ≈ 1.2 × 10⁶ M⁻¹. Transient absorption spectroscopy indicates that DNA binding prolongs the excited-state lifetime and modifies vibrational relaxation pathways. These results highlight how π-system extension in Os(II) complexes modulates photophysical behavior and DNA affinity, offering insights for the rational design of NIR-emitting, DNA-targeted luminescent probes and potential phototherapeutic agents. Full article

Oligo(arylene ethynylene)s (OAEs) containing 4,5-(diethynylaryl)-1,2,3-triazoles with 3(OMe) and NR₂ substituents at the 5-position and bis-1,4-dialkoxybenzene moieties as spacers at the 4-position were obtained using the retro-Favorskii reaction as a key step. The most intense fluorescence was observed for OAEs with a trimethoxyphenyl substituent in THF solutions, with a quantum yield of up to 88%. Increasing the solvent polarity had minimal effect on the emission of trimethoxyphenyl substituted derivatives. A notable red shift in emission spectra was observed with increasing solvent polarity for OAEs 10a,g containing para-dimethylaminophenyl group. Their emission spectra in aqueous organic solutions revealed that an increase in water fraction in THF/water mixtures led to a bathochromic shift in emission spectra maxima accompanied by a hypochromic effect. An increase in intensity was observed in aqueous acetonitrile and DMSO. The maximum intensity was observed in DMSO solutions containing 30% water, which is attributed to aggregate-induced emission enhancement. Dynamic light scattering data also confirmed the formation of nanoscale aggregates in aqueous organic mixtures. Full article

Introduction: In hemoglobinopathies, the amount of globin synthesis in hemoglobin (Hb) or its structure is altered. Clinical features are related to the rate and kind of structural aberrations. The heterozygous form of the Lepore syndrome resembles minor thalassemia both clinically and hematologically. On electrophoresis, abnormal Hb Lepore fractions are found at a rate of 5–15%, with a mildly higher percentage of HbF and lower HbA. In general, Hb Lepore heterozygotes are asymptomatic. Case presentation: A 32-year-old male was admitted to our hospital with complaints of pain and swelling in multiple large joints and high-grade fever for 11 days. His past history was unremarkable; one of his sisters had the β-thalassemia trait. On physical examination, he was moderately anemic, with mild hepatomegaly and normal spleen; both knees and ankles were tender and swollen. Laboratory showed mild microcytic hypochromic anemia with variables similar to the thalassemia trait and signs of inflammation with very high CRP, serum ferritin, and leukocytosis. Blood sugars were increased. Hb electrophoresis showed an abnormal pattern with mild elevation in HbS, normal Hb F, mild reduction in HbA, and high HbA2, compatible with heterozygosity for the Hb Lepore beta chain variant. He was initially diagnosed with diabetes (treated with insulin) and sepsis from unknown origin, but fever and joint pains did not respond to NSAIDs or antibiotics. He had very good response on high-dose methylprednisolone. Undifferentiated arthritis was diagnosed in the patient with Hb Lepore, and he was treated with oral prednisolone and sulfasalazine (SSZ). At follow up, the patient was doing well. He refused further investigations and did not allow testing on his family members. In summary: Hb Lepore is a rare hemoglobinopathy linked to thalassemia, which may manifest with musculoskeletal problems. Our patient with the Hb Lepore trait presented with undifferentiated polyarthritis and fever, but in our case, a causal relationship remains unclear. This is one of the first adult cases of Hb Lepore in Bangladesh and the first with arthritis of unknown origin. The prevalence of Hb Lepore in Bangladesh is unknown. Full article

Sheep pox, caused by sheep pox virus (SPV), is a transboundary disease that threatens sheep production and trade. This study aimed to identify genetic, immunological, and biochemical markers associated with susceptibility to SPV in Barki ewes. A total of 100 adult ewes were examined, including 50 clinically healthy and 50 naturally infected animals. PCR detected SPV DNA in 60% of suspected scab samples, highlighting diagnostic challenges in field investigations. Blood samples were analyzed for hematological indices, cytokine profiles, acute phase proteins, oxidative stress biomarkers, iron metabolism, and hormonal parameters. Expression profiles and single-nucleotide polymorphisms (SNPs) in 15 immune and antioxidant genes were characterized from cDNA-derived sequences. Infected animals exhibited microcytic hypochromic anemia, leukocytosis, elevated proinflammatory cytokines, and reduced IL-10. Acute phase proteins, oxidative stress markers, and cortisol were increased, whereas antioxidant capacity and transferrin were reduced. Twenty-three SNPs were identified, including non-synonymous variants, which showed promising but unvalidated associations with disease status. These findings highlight immune, oxidative, and genetic alterations in SPV-infected sheep, but further longitudinal and cross-validated studies are needed to establish their diagnostic or breeding utility. Full article

A novel near-infrared (NIR) squaraine-based chemosensor, SQ-68, has been designed and synthesized for the sensitive and selective detection of Cu²⁺ and Ag⁺ ions, offering a compact solution for multi-analyte sensing. SQ-68 demonstrates high selectivity, with its performance influenced by the solvent environment: It selectively detects Cu²⁺ in acetonitrile and Ag⁺ in an ethanol–water mixture. Upon binding with either ion, SQ-68 undergoes significant absorption changes in the NIR region, accompanied by visible color changes, enabling naked-eye detection. Spectroscopic studies confirm a 1:1 binding stoichiometry with both Cu²⁺ and Ag⁺, accompanied by hypochromism. The detection limits are 0.09 μM for Cu²⁺ and 0.38 μM for Ag⁺, supporting highly sensitive quantification. The sensor’s practical applicability was validated in real water samples (sea, lake, and tap water), with recovery rates ranging from 73–95% for Cu²⁺ to 59–99% for Ag⁺. These results establish SQ-68 as a reliable and efficient chemosensor for environmental monitoring and water quality assessment. Its dual-analyte capability, solvent-tunable selectivity, and visual detection features make it a promising tool for rapid and accurate detection of heavy metal ions in diverse aqueous environments. Full article

Background: Seasonal influenza viruses are primarily known for causing respiratory illness, but rare hematologic complications can occur, especially in young children. While influenza A is more commonly linked to severe manifestations, influenza B can similarly precipitate life-threatening cytopenias, particularly in toddlers. Case Presentation: We report the case of a previously healthy 1-year-and-8-months-old girl who presented with a high fever, cough, and marked pallor during peak influenza season. Laboratory tests revealed significant microcytic, hypochromic anemia and severe thrombocytopenia. Rapid antigen testing was positive for influenza B. An extensive workup for other causes of bicytopenia, including leukemia, hemolysis, aplastic anemia, and other viral infections, yielded negative results. The child was managed with urgent red blood cell and platelet transfusions, oseltamivir antiviral therapy, broad-spectrum antibiotics, corticosteroids, and supportive care. Bone marrow aspiration was deferred in light of the rapid hematologic recovery. Her hemoglobin greatly improved, and her platelet count reached normal values at discharge. Conclusions: Our case underscores the need to consider influenza in the differential diagnosis of unexplained cytopenias during flu season. This case illustrates that influenza B can mimic hematologic malignancies. Rapid diagnosis and supportive treatment are essential to avoid fatal outcomes. Influenza vaccination plays a significant role in preventing severe complications, such as those we encountered. Full article

Background/Objectives: Aberrant expression of c-MYC drives aggressive cancers. A guanine-rich promoter sequence (Pu27) folds into a transcriptionally repressive G-quadruplex (G4). Epigallocatechin gallate (EGCG), the main green tea polyphenol, displays anticancer activity, but clear, easily replicated evidence for direct binding to the c-MYC G4 is lacking. We therefore obtained the first biophysical confirmation of an EGCG–c-MYC G4 interaction using routine UV–visible spectroscopy. Methods: A pre-annealed Pu27 G4 (5 µM) in potassium-rich buffer was titrated with freshly prepared EGCG (0–20 µM) at 25 °C. Full-range UV–Vis spectra (220–400 nm) were recorded after each addition, and absorbance variations at the DNA (260 nm) and ligand (275 nm) maxima were quantified across three independent replicates. Results: EGCG induced pronounced, concentration-dependent hyperchromicity at 260 nm, reaching ~8–10% above baseline at a 4:1 ligand/DNA ratio and exhibiting saturable binding behaviour. Concurrently, the 275 nm band displayed relative hypochromicity coupled with a subtle bathochromic shift. These reciprocal perturbations—absent in buffer-only controls—constitute definitive evidence of a specific EGCG•G4 complex most consistent with external π-stacking or groove engagement rather than intercalation. Conclusions: This study delivers the first rigorous, quantitative UV–Vis confirmation that a readily consumed dietary polyphenol directly targets the c-MYC promoter G4. By marrying conceptual elegance with methodological accessibility, it provides a compelling molecular rationale for EGCG’s anti-oncogenic repertoire, inaugurates an expedient platform for screening G4-reactive nutraceuticals, and paves the way for structural and cellular investigations en route to next-generation c-MYC-directed therapies. Full article

This paper presents a systematic absorption and circular dichroism spectroscopy study of short single strands of DNA, from 2 to 20 bases. They are composed of a sequence-specific nucleobase composition, either adenine (A), thymine (T), or AT repeats. The absorption spectra hypochromism and the circular dichroism one show butterfly-shaped spectra. Data analysis conducted on the spectra of these oligomers provides evidence for the formation of excitons and their delocalization length along the strand of DNA in relation to how many bases are involved in the excitonic coupling. In particular, the extent of this coupling is limited to adjacent nucleobases in the case of pure adenine strands but spans multiple nucleobases in the case of pure thymine strands. Predictably, AT repeats show a mixed behavior between the two. Full article

Background/Objectives. Iron deficiency is one of the most common nutritional deficiencies worldwide and is the leading cause of anemia in the pediatric population (microcytic, hypochromic anemia due to iron deficiency). Moreover, untreated iron deficiency can lead to various systemic consequences and can disrupt the child’s development. Methods/Results. Therefore, a team of experts from the Polish Pediatric Society, the Polish Society of Pediatric Oncology and Hematology, the Polish Neonatology Society, and the Polish Society of Family Medicine, based on a review of the current literature, their own clinical experience, and critical discussion, has developed updated guidelines for the diagnosis, prevention, and treatment of iron deficiency in children from birth to 18 years of age. These recommendations apply to the general population and do not take into account the specifics of individual conditions and diseases. Full article

Background: Iron deficiency anemia (IDA) and the β-thalassemia trait (BTT) are two main causes of hypochromic–microcytic anemia worldwide. Researchers have described many red blood cell (RBC) indices as screening tests for presumptive differentiation, based on differences observed in complete blood count (CBC) data for each condition. There are few BTT reports in Chile, and neither laboratories nor clinical staff have widely used these indices. Objective: The objective of this study was to evaluate the diagnostic performance of 29 RBC indices in 182 patients (51 BTT and 131 IDA) and compare CBC results in both groups. Methods: A retrospective search was carried out in the Laboratory Information System between January 2021 and February 2024 to collect results from CBC, and 29 RBC indices were calculated for each patient. Then, sensitivity, specificity, positive predictive value, negative predictive value, Youden’s index, positive likelihood ratio, negative likelihood ratio, and diagnostic accuracy were calculated using MedCalc©. Results: The Green and King, Wongprachum, and Keikhaei indices showed the best discriminatory power with Youden index values of 0.923, 0.908, and 0.896, respectively, and significant differences were observed in all CBC parameters between BTT and IDA patients (p < 0.001). Conclusions: The Green and King, Wongprachum, and Keikhaei indices showed the best performance; therefore, they can be used as screening for the differential diagnosis between BTT and IDA in order to improve diagnosis given the important therapeutic and epidemiological implications. In this way, clinical laboratories could have a main role in the investigation of these patients. Full article

In this study, we used ultraviolet-visible (UV-Vis), fluorescence, and circular dichroism (CD) techniques, as well as molecular modeling, to probe the interactions between carbazole derivatives and the G-quadruplex structure formed in the promoter region of gene Bcl-2. This gene is a rational target for anticancer therapy due to its high expression in a variety of tumors as well as resistance to chemotherapy-induced apoptosis. We employed a sequence with a specific dual G-to-T mutation that may form a mixed-type hybrid G-quadruplex structure in the Bcl-2 P1 promoter region. The three tested carbazole compounds differing in substitution on the nitrogen atom of carbazole interact with the Bcl-2 G-quadruplex by the same binding mode with the very comparable binding affinities in the order of 10⁵ M⁻¹. During absorption and fluorescence measurements, large changes in the ligand spectra were observed at higher G4 concentrations. The spectrophotometric titration results showed a two-step complex formation between the ligands and the G-quadruplex in the form of initial hypochromicity followed by hyperchromicity with a bathochromic shift. The strong fluorescence enhancement of ligands was observed after binding to the DNA. All of the used analytical techniques, as well as molecular modeling, suggested the π–π interaction between carbazole ligands and a guanine tetrad of the Bcl-2 G-quadruplex. Molecular modeling has shown differences in the interaction between each of the ligands and the tested G-quadruplex, which potentially had an impact on the binding strength. Full article

The effect of helminthiasis on host immunity is a neglected area of research, particularly in tuberculosis (TB) infection. This study aimed to evaluate the effect of helminthiasis on immunological and haematological parameters in newly diagnosed TB patients in Bobo-Dioulasso. After all biological analyses, we formed three subpopulations: group 1 (n = 82), as control, were participants without helminthic or Mycobacterium tuberculosis complex infection (Mtb−/Helm−), group 2 (n = 73) were TB patients without helminthic infection (Mtb+/Helm−), and group 3 (n = 22) were TB patients with helminthic infection (Mtb+/Helm+). The proportion of helminth coinfection was 23.16% (22/95) in TB patients, and Schistosoma mansoni infection was found in 77.3% (17/22) cases of helminthiasis observed in this study. A low CD4 T cell count and a low CD4:CD8 ratio were significantly associated with concomitant infection with helminths and the Mtb complex (Mtb+/Helm+) compared to the other groups (p < 0.05). However, there was no statistically significant difference in the CD8 median among the three participating groups (p > 0.05). Lymphopenia, monocytosis, thrombocytosis, and hypochromic microcytic anaemia were the haematological defects observed in the Mtb+/Helm+ and Mtb+/Helm− patients. Exploring these types of immune–haematological biomarkers would be a valuable aid in diagnosing and a better follow-up and monitoring of the tuberculosis–helminthiasis coinfection. Full article