-
Nature Communications Sep 2023Catalytic asymmetric α-alkylation of carbonyl compounds represents a long-standing challenge in synthetic organic chemistry. Herein, we advance a dual biocatalytic...
Catalytic asymmetric α-alkylation of carbonyl compounds represents a long-standing challenge in synthetic organic chemistry. Herein, we advance a dual biocatalytic platform for the efficient asymmetric alkylation of α-keto acids. First, guided by our recently obtained crystal structures, we develop SgvM as a general biocatalyst for the enantioselective methylation, ethylation, allylation and propargylation of a range of α-keto acids with total turnover numbers (TTNs) up to 4,600. Second, we mine a family of bacterial HMTs from Pseudomonas species sharing less than 50% sequence identities with known HMTs and evaluated their activities in SAM regeneration. Our best performing HMT from P. aeruginosa, PaHMT, displays the highest SAM regeneration efficiencies (TTN up to 7,700) among HMTs characterized to date. Together, the synergistic use of SgvM and PaHMT affords a fully biocatalytic protocol for asymmetric methylation featuring a record turnover efficiency, providing a solution to the notorious problem of asymmetric alkylation.
Topics: Methyltransferases; Alkylation; Biocatalysis; Engineering; Keto Acids; Methenamine; Pseudomonas aeruginosa
PubMed: 37709735
DOI: 10.1038/s41467-023-40980-w -
Acta Tropica Jun 2024A clinical case of an adult horse with invasive, ulcerative, proliferative, pyogranulomatous disease of the skin (tumor) in the shoulder region is presented. The mass...
A clinical case of an adult horse with invasive, ulcerative, proliferative, pyogranulomatous disease of the skin (tumor) in the shoulder region is presented. The mass had a granulomatous and crater-shaped appearance, with serosanguinous discharge and the presence of fistulas with caseous material. The tumor was removed by surgery and sent to the laboratory for diagnosis. Histopathology was performed using Grocott-Gomori methenamine silver stain. The presence of necrotic material, fibrosis, infiltrated cells, and brown-colored hyphae, characteristic of members of the genus Pythium, were observed. To identify the infecting species, conventional PCRs for the amplification of the ITS-1 was carried out. Histopathological and PCR tests confirmed infection by a Pythium insidiosum strain closely associated with previous records from the US and Central America. Our report represents the first molecularly confirmed case of equine pythiosis in Mexico.
Topics: Animals; Pythiosis; Horses; Pythium; Horse Diseases; Mexico; Polymerase Chain Reaction; DNA, Ribosomal Spacer; Male; Histocytochemistry; Skin
PubMed: 38548212
DOI: 10.1016/j.actatropica.2024.107195 -
International Journal of Surgical... Feb 2024Lipoprotein glomerulopathy is an infrequent glomerular disorder that culminates in nephrotic syndrome and often progresses to kidney failure. Whereas most patients have...
Lipoprotein glomerulopathy is an infrequent glomerular disorder that culminates in nephrotic syndrome and often progresses to kidney failure. Whereas most patients have been reported in Japan and China, limited reports have been documented outside these regions. This patient represents the first report of lipoprotein glomerulopathy in Pakistan. A 25-year-old male patient, hypertensive for 2 years, presented with progressive body edema, frothy urine, and fatigue. Examination revealed elevated blood pressure, bilateral pedal edema, and positive shifting dullness. Laboratory results showed significant proteinuria and elevated cholesterol and triglyceride levels. Renal biopsy revealed enlarged glomeruli with a dilated capillary lumen filled with pale-staining mesh-like material "lipoprotein thrombi." Mild tubular atrophy and interstitial inflammation were observed. No interstitial fibrosis was evident. Electron microscopy detailed the lipoprotein thrombi with lipid granules and vacuoles of various sizes. A diagnosis of lipoprotein glomerulopathy was rendered. Treatment with fenofibrate, rosuvastatin, and captopril led to notable improvements in symptoms, blood pressure, and lipid levels during a 6-month follow-up. Subsequent biopsy showed complete resolution of the lipoprotein thrombi and a significant reduction in subendothelial granular densities. However, the flocculent subendothelial material persisted to some extent despite the complete resolution of lipoprotein thrombi. This report underscores the rarity of lipoprotein glomerulopathy in Pakistan and contributes valuable insights into its histopathologic features and global epidemiology. This unique instance aims to raise awareness among healthcare professionals, aiding in improved recognition of this rare entity. The favorable response to fenofibrate treatment underscores its effectiveness in managing lipoprotein glomerulopathy.
PubMed: 38327135
DOI: 10.1177/10668969241228298 -
The European Physical Journal. E, Soft... Dec 2023It is well established that deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) exhibit a reentrant condensation (RC) phase behavior in the presence of the trivalent...
It is well established that deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) exhibit a reentrant condensation (RC) phase behavior in the presence of the trivalent hexamine cobalt(III) cations (Hac) which can be important for their packing and folding. A similar behavior can be observed for negatively charged globular proteins in the presence of trivalent metal cations, such as Y or La. This phase behavior is mainly driven by charge inversion upon an increasing salt concentration for a fixed protein concentration (c). However, as Hac exhibits structural differences compared to other multivalent metal cations, with six ammonia ligands (NH) covalently bonded to the central cobalt atom, it is not clear that Hac can induce a similar phase behavior for proteins. In this work, we systematically investigate whether negatively charged globular proteins β-lactoglobulin (BLG), bovine serum albumin (BSA), human serum albumin (HSA) and ovalbumin (OVA) feature Hac-induced RC. Effective protein-protein interactions were investigated by small-angle X-ray scattering. The reduced second virial coefficient (B/B) was obtained as a function of salt concentration. The virial coefficient analysis performed confirms the reentrant interaction (RI) behavior for BLG without actually inducing RC, given the insufficient strengths of the interactions for the latter to occur. In contrast, the strength of attraction for BSA, HSA and OVA are too weak to show RC. Model free analysis of the inverse intensity [Formula: see text] also supports this finding. Looking at different q-range by employing static (SLS) and dynamic light scattering experiments, the presence of RI behavior can be confirmed. The results are further discussed in view of metal cation binding sites in nucleic acids (DNA and RNA), where Hac induced RC phase behavior.
Topics: Humans; Chlorides; Cobalt; Methenamine; Serum Albumin, Bovine; Cations; DNA; RNA; Solutions
PubMed: 38051398
DOI: 10.1140/epje/s10189-023-00376-6 -
BMJ Open Apr 2024To estimate the cost-effectiveness of methenamine hippurate compared with antibiotic prophylaxis in the management of recurrent urinary tract infections. (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
Cost-effectiveness of methenamine hippurate compared with antibiotic prophylaxis for the management of recurrent urinary tract infections in secondary care: a multicentre, open-label, randomised, non-inferiority trial.
OBJECTIVES
To estimate the cost-effectiveness of methenamine hippurate compared with antibiotic prophylaxis in the management of recurrent urinary tract infections.
DESIGN
Multicentre, open-label, randomised, non-inferiority trial.
SETTING
Eight centres in the UK, recruiting from June 2016 to June 2018.
PARTICIPANTS
Women aged ≥18 years with recurrent urinary tract infections, requiring prophylactic treatment.
INTERVENTIONS
Women were randomised to receive once-daily antibiotic prophylaxis or twice-daily methenamine hippurate for 12 months. Treatment allocation was not masked and crossover between arms was allowed.
PRIMARY AND SECONDARY OUTCOME MEASURES
The primary economic outcome was the incremental cost per quality-adjusted life year (QALY) gained at 18 months. All costs were collected from a UK National Health Service perspective. QALYs were estimated based on responses to the EQ-5D-5L administered at baseline, 3, 6, 9, 12 and 18 months. Incremental costs and QALYs were estimated using an adjusted analysis which controlled for observed and unobserved characteristics. Stochastic sensitivity analysis was used to illustrate uncertainty on a cost-effectiveness plane and a cost-effectiveness acceptability curve. A sensitivity analysis, not specified in the protocol, considered the costs associated with antibiotic resistance.
RESULTS
Data on 205 participants were included in the economic analysis. On average, methenamine hippurate was less costly (-£40; 95% CI: -684 to 603) and more effective (0.014 QALYs; 95% CI: -0.05 to 0.07) than antibiotic prophylaxis. Over the range of values considered for an additional QALY, the probability of methenamine hippurate being considered cost-effective ranged from 51% to 67%.
CONCLUSIONS
On average, methenamine hippurate was less costly and more effective than antibiotic prophylaxis but these results are subject to uncertainty. Methenamine hippurate is more likely to be considered cost-effective when the benefits of reduced antibiotic use were included in the analysis.
TRIAL REGISTRATION NUMBER
ISRCTN70219762.
Topics: Humans; Urinary Tract Infections; Cost-Benefit Analysis; Female; Hippurates; Middle Aged; Methenamine; Quality-Adjusted Life Years; Adult; Antibiotic Prophylaxis; Recurrence; United Kingdom; Anti-Bacterial Agents; Aged
PubMed: 38684270
DOI: 10.1136/bmjopen-2023-074445 -
Gene Jun 2024Periodontitis is associated with Fusobacterium nucleatum (F.n) infection. Although the colonization of renal tissue by F.n is well documented, its specific role in...
OBJECTIVES
Periodontitis is associated with Fusobacterium nucleatum (F.n) infection. Although the colonization of renal tissue by F.n is well documented, its specific role in kidney disease has yet to be determined. This study aimed to investigate the potential association between F.n-induced periodontitis and renal interstitial fibrosis.
METHODS
The rat gingival sulcus was injected with F.n suspension, while the control group (NC) was injected with PBS. The levels of total protein (TP), albumin (ALB), creatinine, and urea nitrogen (BUN) in rat serum and/or urine were quantified using the appropriate kits. Renal interstitial fibrosis and epithelial-mesenchymal transition (EMT) were evaluated in rats using Masson staining, Periodic Schiff-Methenamine (PASM) staining, and immunohistochemical staining. The levels of fibrosis- and EMT-related proteins and the TGF-β/SMAD2/3 and β-catenin signaling pathways were determined using Western blot analysis. F.n in the kidney tissues was quantitatively determined using bacterial 16S rRNA technology.
RESULTS
Serum levels of TP, ALB, creatinine, and BUN were not significantly decreased in F.n-infected rats with periodontitis. The levels of creatinine and ALB in the urine were not statistically different between two groups. Masson and PASM staining showed that F.n-induced periodontitis could promote renal interstitial fibrosis in rats. The levels of collagen I, fibronectin (FN), vimentin, and α-SMA were upregulated in the kidney tissues of rats with F.n-induced periodontitis and in F.n-treated HK-2 cells. However, E-cadherin levels were reduced. F.n promoted renal interstitial and HK-2 cell fibrosis in rats by modulating the TGF-β/SMAD2/3 and β-catenin signaling pathways. F.n colonization increased renal interstitial fibrosis in rats.
CONCLUSION
F.n-induced periodontitis promoted EMT by activating the TGF-β/SMAD2/3 and β-catenin signaling pathways, thus promoting renal interstitial fibrosis in rats.
PubMed: 38936784
DOI: 10.1016/j.gene.2024.148729 -
BMC Infectious Diseases Jun 2024Malassezia restricta, a lipophilic and lipodependent yeast belonging to the basidiomycetes group, is an opportunistic fungal pathogen associated with various skin... (Review)
Review
BACKGROUND
Malassezia restricta, a lipophilic and lipodependent yeast belonging to the basidiomycetes group, is an opportunistic fungal pathogen associated with various skin diseases, including seborrheic dermatitis and dandruff. Typically, Malassezia infection in neonates manifests as fungemia or hematogenous dissemination to the bone or lungs. However, vertebral osteomyelitis caused by these fungi is rarely reported owing to non-specific clinical presentations and laboratory/imaging findings. The Pathogen Metagenomics Sequencing (PMseq) technique enables direct high-throughput sequencing of infected specimens, facilitating the rapid and accurate detection of all microorganisms in clinical samples through comprehensive reports.
CASE PRESENTATION
A 52-year-old male was admitted to our hospital on July 20, 2022 with a 3-month history of ambulatory difficulties and localized low back pain. Magnetic Resonance Imaging (MRI) examination of the spinal column revealed irregular bone destruction affecting the L2, L3, and L5 vertebral bodies. Additionally, low T1 and high T2 intensity lesions were observed at the intervertebral discs between L3 and L5. The presumptive diagnosis of tuberculous spondylitis was made based on the imaging findings, despite negative results in all mycobacterium tests. However, the patient exhibited no improvement after receiving regular anti-tuberculosis treatment for 3 months. Subsequent MRI revealed an expansive abnormal signal within the vertebral body, leading to progressive bone destruction. The absence of spinal tuberculosis or other infective microorganisms was confirmed through culture from blood and pathological tissue from the L4 vertebral body. Subsequently, PMseq was performed on the specimens, revealing M. restricta as the predominant pathogen with the highest relative abundance value. The pathological examination revealed the presence of fungal mycelium in the L4 vertebral body, with positive findings on periodic Schiff-methenamine and periodic acid-Schiff staining. The anti-tuberculosis treatment was discontinued, and an antifungal combination of fluconazole and voriconazole was administered. All symptoms were resolved after 7 consecutive months of treatment, and the patient was able to ambulate autonomously. Vertebral lesions were reduced on MRI during the 13-month follow-up.
CONCLUSIONS
M. restricta is not a commonly recognized pathogen associated with infectious vertebral osteomyelitis. However, PMseq can aid in diagnosis, timely treatment, and decision making for some non-specific infectious diseases.
Topics: Humans; Male; Osteomyelitis; Middle Aged; Malassezia; Metagenomics; Magnetic Resonance Imaging; Antifungal Agents; High-Throughput Nucleotide Sequencing
PubMed: 38926679
DOI: 10.1186/s12879-024-09512-9 -
Unique presentation of late-onset Pneumocystis pneumonia in a pediatric kidney transplant recipient.Pediatric Transplantation Sep 2023Restrictive lung disease leading to abnormal lung function in kidney transplant recipients is commonly associated with noninfectious complications or medications used...
BACKGROUND
Restrictive lung disease leading to abnormal lung function in kidney transplant recipients is commonly associated with noninfectious complications or medications used for post-transplant immunosuppression. Herein, we report an interesting case of pediatric kidney transplant recipient with weight loss and abnormal spirometry who was diagnosed to have late-onset Pneumocystis pneumonia.
CASE REPORT
A 17-year-old male patient with a history of allergic rhinitis, mild persistent asthma, and deceased donor kidney transplant, performed 18 months prior, presented for routine evaluation of his asthma to the pulmonology clinic. He was clinically asymptomatic except for a weight loss of 8 kg over 6-month period prior to presentation. Patient's spirometry was suggestive of a restrictive pattern and further investigation using a high-resolution computed tomography (HRCT) of the chest showed bilateral diffuse ground-glass reticulonodular opacities with subpleural sparing suggestive of interstitial pneumonitis. A bronchoscopy with bronchoalveolar lavage revealed organisms consistent with Pneumocystis jirovecii on gomori-methenamine-silver (GMS) staining. Beta-d-glucan testing in serum revealed a level of >500 pg/mL (normal 0-59 pg/mL) further supportive of Pneumocystis jirovecii infection. Patient was treated with a 6-week course of trimethoprim-sulfamethoxazole. His weight loss and beta-d-glucan levels improved over a course of 6 months, and he continues to be on trimethoprim-sulfamethoxazole prophylaxis.
CONCLUSION
Late-onset Pneumocystis jirovecii infection in kidney transplant recipients can have an atypical presentation. Treating physicians should consider PJP in the differential diagnosis of unexplained weight loss in pediatric kidney transplant recipients, especially those receiving a large cumulative burden of immunosuppression.
Topics: Male; Humans; Child; Adolescent; Pneumonia, Pneumocystis; Trimethoprim, Sulfamethoxazole Drug Combination; Kidney Transplantation; Pneumocystis carinii; Immunosuppression Therapy
PubMed: 37448256
DOI: 10.1111/petr.14576 -
Journal of Fluorescence Jan 2024Carbon quantum dots (CQDs) are a new type of fluorescent QDs that consists mainly of carbon atoms. In this research, CQDs were synthesized through harsh oxidizing...
Carbon quantum dots (CQDs) are a new type of fluorescent QDs that consists mainly of carbon atoms. In this research, CQDs were synthesized through harsh oxidizing conditions applied on carbon black and subsequent N-doping using hexamethylenetetramine (Hexamine) and polyethyleneimine (PEI). The synthesized CQDs were characterized using FTIR, AFM, UV-Visible spectroscopy, photoluminescence (PL) spectroscopy, and fluorescence imaging respectively. The AFM images showed that the dots are in the range of 2-8 nm. N-doping of the CQDs increased the PL intensity. The PL enhancement for the CQDs that were N-doped with PEI was higher compared to those N-doped with hexamine. The shift in PL by changing the excitation wavelength has been attributed to the nano-size of the CQDs, functional groups, defect traps, and quantum confinement effect. The in vitro fluorescence imaging revealed that N-doped CQDs can internalize into the cells and be used for fluorescent cell imaging.
Topics: Soot; Quantum Dots; Carbon; Methenamine
PubMed: 37191828
DOI: 10.1007/s10895-023-03252-w -
Archives of Pathology & Laboratory... Feb 2024The diagnosis of some infectious diseases requires their identification in tissue specimens. As institutions adopt digital pathology for primary diagnosis, the limits of...
Digital Pathology in the Detection of Infectious Microorganisms: An Evaluation of Its Strengths and Weaknesses Across a Panel of Immunohistochemical and Histochemical Stains Routinely Used in Diagnostic Surgical Pathology.
CONTEXT.—
The diagnosis of some infectious diseases requires their identification in tissue specimens. As institutions adopt digital pathology for primary diagnosis, the limits of microorganism detection from digital images must be delineated.
OBJECTIVE.—
To assess the reliability of microorganism detection from digitized images of histochemical and immunohistochemical stains commonly used in pathology.
DESIGN.—
Original glass slides from 620 surgical pathology cases evaluated for the presence of infectious microorganisms were digitized. Immunohistochemical stains included those for herpes simplex virus (n = 100), cytomegalovirus (n = 100), Helicobacter pylori (n = 100), and spirochetes (n = 80). Histochemical stains included mucicarmine for Cryptococcus spp (n = 20), Grocott methenamine silver for fungi (n = 100), Giemsa for H pylori (n = 100), and Ziehl-Neelsen for acid-fast bacilli (n = 20). The original diagnosis based on the glass slides was regarded as the reference standard. Six pathologists reviewed the digital images.
RESULTS.—
Digital review was generally associated with high (ie, ≥90%) specificity and positive predictive value owing to a low percentage of false positive reads, whereas a high percentage of false negatives contributed to low sensitivity and negative predictive value for many stains. Fleiss κ showed substantial interobserver agreement in the interpretation of Grocott methenamine silver and immunostains for herpes simplex virus, H pylori, and cytomegalovirus; moderate agreement for spirochete, Ziehl-Neelsen, and mucicarmine; and poor agreement for Giemsa.
CONCLUSIONS.—
Digital immunohistochemistry generally outperforms histochemical stains for microorganism detection. Digital interpretation of Ziehl-Neelsen and mucicarmine stains is associated with low scores for interrater reliability, accuracy, sensitivity, and negative predictive value such that it should not substitute for conventional review of glass slides.
PubMed: 38385999
DOI: 10.5858/arpa.2023-0214-OA