Chemical synthesis of grafted cyclotides using a "plug and play" approach.

Cyclotides are a diverse class of plant-derived cyclic, disulfide-rich peptides with a unique cyclic cystine knot topology. Their remarkable structural stability and resistance to proteolytic degradation can lead to improved pharmacokinetics and oral activity as well as selectivity and high enzymatic stability. Thus, cyclotides have emerged as powerful scaffold molecules for designing peptide-based therapeutics. The chemical engineering of cyclotides has generated novel peptide ligands of G protein-coupled receptors (GPCRs), today's most exploited drug targets. However key challenges potentially limit the widespread use of cyclotides in molecular grafting applications. Folding of cyclotides containing bioactive epitopes remains a major bottleneck in cyclotide synthesis. Here we present a modular 'plug and play' approach that effectively bypasses problems associated with the oxidative folding of cyclotides. By grafting onto a pre-formed acyclic cyclotide-like scaffold we show that difficult-to-graft sequences can be easily obtained and can target GPCRs with nanomolar affinities and potencies. We further show the suitability of this new method to graft other complex epitopes including structures with additional disulfide bonds that are not readily available via currently employed chemical methods, thus fully unlocking cyclotides to be used in drug design applications.

Knowledge, awareness, and perception of digital dentistry among Egyptian dentists: a cross-sectional study.

BACKGROUND: Digital dentistry has revolutionized the way dental treatment is offered to patients. It became essential for dental practitioners to be well-informed about this technology to improve the quality of care offered and increase patient satisfaction. This study aimed to assess the level of knowledge, awareness, and perception of Egyptian dentists toward digital dentistry. METHODS: An online-based cross-sectional study was conducted using social media platforms from November 2022 to March 2023. Our study sample included dentists with different levels of experience, specialties, and working in different health sectors in Egypt. A questionnaire arranged in 4 sections and 23 questions was used as the study data collection tool. The data were tabulated and analyzed using SPSS software. RESULTS: A total of 402 participants filled out this questionnaire. 50.7% of which were females, 42.8% were between 20-29 years old and 42.3% were general practitioners. Furthermore, the main practice of 27.6% was in governmental dental clinics. Moreover, 47.3% and 64.2% of participants had Moderate knowledge and awareness respectively. While 75.9% of them had a high perception of practicing digital dentistry. Females and practitioners in governmental clinics had significantly lower awareness scores, while faculty teaching staff had significantly higher scores (P ≤ 0.05). On the other hand, practicing in the Great Cairo region and urban areas was associated with significantly higher knowledge scores (P ≤ 0.05). Similarly, Prosthodontists, periodontists, and restorative dentists had significantly higher scores when compared with general dentists (P ≤ 0.05). CONCLUSIONS: About half of the study participants had Moderate knowledge and awareness levels, while about three-quarters of them had a high level of perception toward practicing digital dentistry. Therefore, more attention should be given to providing dental education programs in this important field at both the undergraduate and postgraduate levels by policymakers.

Characterization of lactic acid bacteria isolated from street pickles of Dhaka, Bangladesh.

Traditionally fermented pickles are a popular street food in Bangladesh famous for their unique flavors and health benefits. Pickles are often prepared by fermentation using lactic acid bacteria (LAB) that can act as probiotics. The study was aimed to isolate and characterize lactic acid bacteria from pickle samples collected from streets of Dhaka city, as well as assess the microbial quality of pickles for food safety. A total of 30 pickle samples of different kinds were collected from streets of Dhaka city. Isolation and identification were conducted using conventional cultural and biochemical tests, followed by molecular confirmation of identity. Antibiotic susceptibility of isolates was investigated against 7 antibiotics of different groups. Antimicrobial activity of LAB isolates was analyzed by well-diffusion assay and phenotypic enterocin activity assay. Physiological characterizations of LAB were performed to determine their tolerance to temperature, salt, pH, bile, carbohydrate fermentation pattern, proteolytic activity and biofilm formation. Fifty isolates were obtained from pickle samples, of which 18% was identified as LAB, including Enterococcus faecalis (6) and Enterococcus faecium (3). The rest included S. aureus (18), E. coli (11), Klebsiella spp. (5), Salmonella (3), Shigella (3) and Pseudomonas aeruginosa (1). Antibiotic resistance pattern revealed higher occurrence of resistance against azithromycin among the non-LAB isolates, but none of the LAB isolates were found to resist any of the antibiotics used. Antimicrobial activity of LAB isolates was not observed against the foodborne isolates. All LAB isolates fermented a wide range of carbohydrates and showed adequate tolerance to salt, pH, temperature and bile. Out of 9 isolates, 5 displayed proteolytic activity, and 6 were found as strong biofilm producer. These results suggest that although the LAB isolates from street pickles collected from Dhaka does not have antimicrobial activities, they still have potential to be used as probiotics. It also shows high occurrence of antibiotic resistant foodborne pathogens in pickles, indicating that consumption of such street food can be serious health hazard.

Special considerations and pitfalls for intracerebral bleeding followed COVID-19 case treated by ECMO.

COVID-19, or coronavirus infection, is an acute respiratory illness caused by the corona virus that can develop into a life-threatening form of ARDS. Extracorporeal membrane oxygenation (ECMO) is a highly effective treatment for life-threatening instances. One of the many complications associated with ECMO was bleeding. COVID patients are at risk for intracerebral bleeding due to several factors, including the drug's action on ACE2 receptors, leading to hypertension, as well as hypercoagulability, dysregulated immune response, DIC, and the use of anticoagulants.

Alterations in Inflammatory Markers and Cognitive Ability after Treatment of Pediatric Obstructive Sleep Apnea.

Background and Objectives: Determination of the impact of obstructive sleep apnea (OSA) on the cognitive function (CF), and serum tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and 1ß levels and the effect of OSA management on these variables in children. Materials and Methods: A total of 224 patients were evaluated using the Pediatric Sleep Questionnaire, the NEPSY score for CF, and polysomnography (PSG) to grade OSA severity according to the apnea/hypopnea index (AHI). Adentonsillectomy (AT) was performed for patients with adenotonsillar hypertrophy grade > 2. Patients with overweight or obesity with mild or moderate OSAS underwent a 6-month protocol of lifestyle intervention (LSI). Blood samples were obtained for an enzyme-linked immunosorbent assay (ELISA) estimation of cytokine levels. All variables were re-evaluated at the end of the 6-month follow-up period. Results: A total of 181 patients had surgical interference and 43 patients underwent a LSI trial; 15 patients failed to respond and underwent surgery. At the end of the follow-up, 33 patients had residual OSAS with a significantly higher incidence among patients with severe OSAS, the mean score of the pediatric sleep questionnaire was significantly decreased in all patients, 181 patients showed an improved NESPY score, and cytokine levels were decreased. The baseline NESPY score, AHI index and sleep questionnaire score were negatively correlated. The percentage of change in the NESPY score and serum cytokine levels showed a positive correlation. Conclusions: OSAS is associated with cognitive dysfunction that significantly improves after adenotonsillectomy. LSI as a therapeutic line is satisfactory for children with mild OSAS and minimal cognitive dysfunction and is of value preoperatively to improve the surgical outcomes of AT.

Variations in Polysomnographic Indices of Obstructive Sleep Apnea following Lingual Tonsil Hypertrophy Excision: Is the Difference Significant?

Background and Objectives: Obstructive sleep apnea (OSA) is a sleep-related respiratory disorder that affects between 5% and 20% of the population. In obstructive sleep apnea, lingual tonsillar hypertrophy (LTH) has been suggested as a contributing factor to airway blockage. Objectives: The aim of this work is to demonstrate the polysomnographic indices and their values in OSA patients with LTH before and after the surgical intervention. Materials and Methods: The study was conducted on eighteen patients endoscopically diagnosed as having LTH, with the main complaints being snoring, sleep apnea, and/or sleep disturbance. Clinical examination, grading of LTH, body mass index (BMI), endoscopic assessment using Muller's maneuver, and sleep endoscopy were recorded for all patients. The Epworth Sleepiness Scale (ESS) and overnight sleep polysomnography (PSG) were conducted before and after the surgical removal of LTH. All data were submitted for statistical analysis. Results: The mean ± SD of the AHI decreased from 33.89 ± 26.8 to 20.9 ± 19.14 postoperatively, and this decrease was of insignificant statistical value. The average SpO2 (%) mean ± SD was 91.14 ± 5.96, while the mean ± SD of the desaturation index was 34.64 ± 34.2. Following surgery, these indices changed to 96.5 ± 1.47 and 9.36 ± 7.58, respectively. The mean ± SD of the ESS was changed after the surgery, from 17.27 ± 6.48 to 7.16 ± 3.56. The mean ± SD of sleep efficacy was 71.2 ± 16.8 and the snoring index mean ± SD was 277.6 ± 192.37, and both improved postoperatively, to become 88.17 ± 9.1 and 62.167 ± 40.01, respectively. Conclusions: The AHI after lingual tonsillectomy showed no statistically significant change. The changes in the average SpO2 (%), desaturation index, sleep efficiency, snoring index, and Epworth Sleepiness Scale following the surgery were statistically significant.

Vaginal Laser Therapy for Stress Urinary Incontinence:A Systematic Review of Prospective Randomized Clinical Trials

The most common type of urinary incontinence in women is stress urinary incontinence (SUI) which negatively impacts several aspects of life.The newly introduced vaginal laser therapy is being considered for treating SUI. This systematic review aimed to evaluate the efficacy of vaginal laser therapy for stress urinary incontinence in menopausal women. We searched the following databases: MEDLINE (via PubMed), EMBASE, Cochrane Library databases, Web of Science, clinical trial registry platforms, and Google Scholar, using the MeSH terms and keywords [Urinary Incontinence, Stress] and [(lasers) OR laser]. In our systematic review, prospective randomized clinical studies on women diagnosed with SUI as per the International Continence Society’s diagnostic criteria were included. The Cochrane Risk-of-Bias assessment tool for randomized clinical trials was used to evaluate the quality of studies. A total of 256 relevant records in literature databases and registers and 25 in additional searches were found. Following a review of the titles, abstracts, and full texts, four studies involving 431 patients were included. Three studies used CO2-lasers, and one used Erbium: YAG-laser. The results of all four studies revealed the short-term improvement of SUI following both the Erbium: YAG-laser and CO2-laser therapy. SUI treatment with CO2-laser and Erbium: YAG-laser therapy is a quick, intuitive, well-tolerated procedure that successfully improves incontinence-related symptoms. The long-term impact of such interventions has not been well established as most trials focused on the short-term effects.

Effect of Rot-, Fire-, and Water-Retardant Treatments on Jute Fiber and Their Associated Thermoplastic Composites: A Study by FTIR.

Natural renewable materials can play a big role in reducing the consumption of synthetic materials for environmental sustainability. Natural fiber-reinforced composites have attracted significant research and commercial importance due to their versatile characteristics and multi-dimensional applications. As the natural materials are easily rotten, flammable, and moisture absorbent, they require additional chemical modification for use in sustainable product development. In the present research, jute fibers were treated with rot-, fire-, and water-retardant chemicals and their corresponding polymer composites were fabricated using a compression molding technique. To identify the effects of the chemical treatments on the jute fiber and their polymeric composites, a Fourier transformed infrared radiation (FTIR) study was conducted and the results were analyzed. The presence of various chemicals in the post-treated fibers and the associated composites were identified through the FTIR analysis. The varying weight percentage of the chemicals used for treating the fibers affected the physio-mechanical properties of the fiber as well as their composites. From the FTIR analysis, it was concluded that crystallinity increased with the chemical concentration of the treatment which could be contributed to the improvement in their mechanical performance. This study provides valuable information for both academia and industry on the effect of various chemical treatments of the jute fiber for improved product development.

Targeting hydrogen sulphide signaling in breast cancer.

INTRODUCTION: Hydrogen sulphide (H2S) has been established as a key member of the gasotransmitters family that recently showed a pivotal role in various pathological conditions including cancer. OBJECTIVES: This study investigated the role of H2S in breast cancer (BC) pathogenesis, on BC immune recognition capacity and the consequence of targeting H2S using non-coding RNAs. METHODS: Eighty BC patients have been recruited for the study. BC cell lines were cultured and transfected using validated oligonucleotide delivery system. Gene and protein expression analysis was performed using qRT-PCR, western blot and flow-cytometry. In-vitro analysis for BC hallmarks was performed using MTT, BrdU, Modified Boyden chamber, migration and colony forming assays. H2S and nitric oxide (NO) levels were measured spectrophotometrically. Primary natural killer cells (NK cells) and T cell isolation and chimeric antigen receptor transduction (CAR T cells) were performed using appropriate kits. NK and T cells cytotoxicity was measured. Finally, computational target prediction analysis and binding confirmation analyses were performed using different software and dual luciferase assay kit, respectively. RESULTS: The H2S synthesizing enzymes, cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE), exhibited elevated levels in the clinical samples that correlated with tumor proliferation index. Knock-down of CBS and CSE in the HER2+ BC and triple negative BC (TNBC) cells resulted in significant attenuation of BC malignancy. In addition to increased susceptibility of HER2+ BC and TNBC to the cytotoxic activity of HER2 targeting CAR T cells and NK cells, respectively. Transcriptomic and phosphoprotein analysis revealed that H2S signaling is mediated through Akt in MCF7, STAT3 in MDA-MB-231 and miR-155/ NOS2/NO signaling in both cell lines. Lastly, miR-4317 was found to function as an upstream regulator of CBS and CSE synergistically abrogates the malignancy of BC cells. CONCLUSION: These findings demonstrate the potential role of H2S signaling in BC pathogenesis and the potential of its targeting for disease mitigation.

Thymoquinone alleviates mitochondrial viability and apoptosis in diclofenac-induced acute kidney injury (AKI) via regulating Mfn2 and miR-34a mRNA expressions.

The current study was prepared to assess the underlying mechanism of diclofenac (Diclo)-stimulated renal oxidative damage (50 mg/kg/day for two consecutive days I.P) and antioxidative, and antiapoptotic effects of Thymoquinone (20 mg/kg/day for 21 days P.O). Exposure of rats to Diclo significantly increased serum urea and creatinine, decreased GSH, catalase, and total antioxidant capacity with a concomitant increase of lipid peroxidation. Diclo significantly decreased renal mitochondrial viability %, increased DNA fragmentation %, caspase 3 activity, and cytochrome C (Cyt C) concentration. Molecular investigations revealed that Diclo administration caused a significant reduction of mitofusin-2 (Mfn2) and increase of microRNA-34a (miR-34a) mRNA expressions with a concomitant decrease of Nrf2 and HO-1 mRNA expressions/protein levels and increase of NF-κB mRNA expressions. Thymoquinone restored renal oxidative/antioxidant redox. Thymoquinone significantly increased the renal mitochondrial viability % and reduced renal DNA fragmentation %, caspase 3 activity, and Cyt C. Moreover, thymoquinone modulated renal Mfn2 and miR-34a as compared to Diclo group. Our findings were confirmed by immunohistochemical assays for detecting the iNOS and NOX4 in renal tissue as well as histopathological investigations. Obtained results demonstrated that thymoquinone possess a potential antioxidant, antiapoptotic defense and exhibited a strong nephroprotective activity against Diclo-induced toxicity.

The Prevalence and Predictors of Post-Stroke Depression and Anxiety During COVID-19 Pandemic.

INTRODUCTION: Stroke is associated with a rise in post-stroke depression (PSD) and anxiety (PSA). In this study, we evaluated the impact of COVID-19 pandemic on the rates of PSD and PSA. METHODS: All stroke admissions to two hospitals in Saudi Arabia during two months were prospectively evaluated for PSD and PSA. NIHSS and serum TSH assessed on admission. PSD and PSA were evaluated using Hospital Anxiety and Depression Scale (HADS). Post-stroke disability was assessed by mRS, while social support assessed by Multidimensional Scale of Perceived Social Support (MSPSS). RESULTS: Among 50 participants (28 males), clinically significant PSD was found in 36%, while PSA in 32%. PSD associated with higher NIHSS (P < 0.001); lower MSPSS (P = 0.003); higher mRS (P = 0.001); and discontinuation of rehabilitation (P = 0.02). PSA was associated with higher TSH (P = 0.01); lower MSPSS (P = 0.03); while discontinuation of rehabilitation was related to less PSA (P = 0.034). Multivariate analysis showed that NIHSS (OR: 1.58, 95% CI: 742-3.37; P = 0.01); and MSPSS score (OR: 0.66, 95% CI: 0.47-0.94; P = 0.002) were associated with PSD; while PSA was related to TSH level (OR: 8.32, 95% CI:1.42-47.23; P = 0.02), and discontinuation of rehabilitation (OR: -0.96, 95% CI: -1.90-0.02; P = 0.04). CONCLUSIONS: Our research shows that the rise in PSD is related to stroke severity and this has not changed significantly during the pandemic; however, PSA showed a noticeable peak. Social deprivation and the lacking levels of rehabilitation related significantly to both.

Prevalence of anxiety and depressive symptoms among emergency physicians in Libya after civil war: a cross-sectional study.

OBJECTIVES: We aimed to identify the prevalence of depression and anxiety among physicians working in the emergency departments of nine tertiary care centres in Libya. DESIGN: This was a cross-sectional study. SETTING: Nine main tertiary centres in Libya PARTICIPANTS: Emergency department doctors were surveyed between December 2018 and February 2019. INTERVENTION: The standardised Hospital Anxiety and Depression Scale (HADS) was selected as a measurement tool for analysing anxiety and depression symptoms; a HADS score of 8 indicated anxiety as well as depression symptoms. The primary outcomes were anxiety and depression, which were tabulated with independent sociodemographic variables. χ2 tests were conducted to compare the prevalence of anxiety and depression between the groups. Statistical analysis was performed using SPSS V.25. RESULTS: A total of 108 out of 150 (72%) emergency physicians from all levels participated in the study and took the survey. The emergency physicians had a mean±SD age of 31.2±4.5 years, and were predominantly males (74 out of 108, 68.5%). Overall, 49 (45.4%) physicians reached the cut-off score to define both depression and anxiety (ie, a score ≥8). In terms of violence, 71 (65.7%) reported incidents of verbal violence, while 26 (24.1%) reported physical violence or abuse by militias. In addition, 28 reported being threatened by militias. CONCLUSION: The high prevalence rate of anxiety and depression is of concern, and the high rate of physical and verbal abuse highlights the range of abuse endured by doctors in Libya. Therefore, screening for anxiety and depression at regular intervals is needed to avoid the deterioration of mental health, which can increase the risk of suicide and dropping out, and decrease the level of healthcare for patients.

Effect of a Self-Etch Adhesive Containing Nanobioglass on Postoperative Sensitivity of Posterior Composite Restorations - A Randomized Trial.

BACKGROUND: Postoperative sensitivity is one of the major problems regarding posterior resin composite restorations that causes patient discomfort, maybe a reason for replacement of the restoration with an additional office time. AIM: To evaluate the effect of the addition of a Nanobioglass to a self-etch adhesive on the reduction of post-operative sensitivity following composite restorations versus a self-etch adhesive that is free of Nanobioglass agent. MATERIALS AND METHODS: Sixteen patients having class II carious lesions were included in the study. After cavity preparation, each tooth was randomised to one of the following restorative treatments. Teeth in the control group were restored using self-etch adhesive (OptiBond All-In-One, Kerr) that is free of nanobioglass agent, and nano-hybrid resin composite (Herculite Ultra, Kerr). Restoration of teeth in the experimental group was similar to the control except that a nanobioglass agent was added to the self-etch adhesive. Patients were contacted for evaluation of postoperative sensitivity at 1 day, 1 week, 1 month, and 3 months. Data were analyzed using friedmann test followed by fisher exact test. RESULTS: The experimental group (self-etch adhesive containing nanobioglass) showed a significantly less postoperative sensitivity compared with the control group (Self-etch adhesive free of nanobioglass) at 1 day, and 1-week evaluation periods. While both groups did not possess any significant difference at 1 month, and 3 months periods. CONCLUSION: The problem of postoperative sensitivity following resin composite restorations could be solved by the addition of bioglass nanoparticles into dental adhesives.

Prevalence, risk factors, and clinical manifestations of schistosomiasis among school children in the White Nile River basin, Sudan.

BACKGROUND: We investigated the prevalence, risk factors, and clinical manifestations of schistosomiasis in White Nile State, Sudan, to determine the local characteristics of schistosomiasis in the White Nile River basin. METHODS: Urine and stool samples were collected from 338 students (176 boys, 162 girls) at three primary schools and were examined using the urine filtration method and the Kato-Katz technique, respectively. Of the students, 200 were interviewed using a semi-structured questionnaire to assess water-contact patterns and health conditions related with urinary schistosomiasis. RESULTS: Of the 338 students, egg-positive rates for S. haematobium and S. mansoni were 45.0% and 5.9%, respectively, and 4.4% were mixed. The intensities of S. haematobium and S. mansoni infection were 1.091 ± 0.744 log EP10 (eggs per 10 mL of urine, mean ± SD = 57 ± 172 EP10) and 1.787 ± 0.844 log EPG (eggs per gram of stool, mean ± SD = 156 ± 176 EPG), respectively. The prevalence and intensity of S. haematobium infection differed significantly among the three schools, but not by gender or age. Urinary schistosomiasis was significantly associated with the frequencies of contaminated water contact, taking baths, swimming, and wading the stream; however, frequencies of these events were not significantly correlated with infection intensity. Self-reported hematuria and dysuria also correlated significantly with urinary schistosomiasis. CONCLUSIONS: The overall prevalence of schistosomiasis, especially urinary schistosomiasis, is high in the White Nile River basin, Sudan, and is closely associated with frequencies of water contact, taking baths, swimming, and wading the stream. We strongly recommend implementation of an integrated schistosomiasis control program in this area.

Ocular involvement and visual outcome of herpes zoster ophthalmicus: review of 45 patients from Tunisia, North Africa.

BACKGROUND: Ocular complications of herpes zoster ophthalmicus (HZO) may lead to substantial visual impairment. The purpose of this study was to characterize and analyze ocular involvement and visual outcome of HZO in patients from Tunisia, North Africa. This study is a retrospective chart review of 51 eyes of 45 patients with HZO. RESULTS: Mean age was 44.5 years. Thirty patients (66.7%) were aged over 50 years. Twenty-four patients (53.3%) were male and 21 patients were female (46.7%). There was no statistically significant difference in gender distribution. Initial mean best corrected visual acuity (BCVA) was 20/50. Ocular manifestations included adnexal involvement (58.8%), keratitis (31.4%), keratouveitis (31.4%), isolated anterior uveitis (AU) (29.4%), intraocular pressure elevation (23.5%), oculomotor nerve palsy (5.8%), and optic neuritis (1.9%). Isolated AU (p < 0.001), isolated keratitis (p = 0.001), and intraocular pressure elevation (p = 0.013) were more likely to be concomitant to HZO active skin disease, while keratouveitis occurred more likely more than 1 month after HZO eruption (p < 0.001). AU and keratouveitis were more likely to be associated with age ≥ 50 years (p = 0.001 and p = 0.02, respectively). Ocular complications included neurotrophic keratopathy (1.9%), corneal opacity (5.9%), secondary glaucoma (7.8%), optic atrophy (1.9%), and postherpetic neuralgia (13.3%). Mean follow-up was 12 months. Mean final BCVA was 20/32; it was ≥ 20/40 in 78.4% of the eyes. CONCLUSIONS: Our study provided epidemiologic and clinical data of HZO in a Tunisian population. AU and keratitis were the most common ocular complications. Neurotrophic keratopathy was scarce. The overall visual outcome is good, with about three quarters of the treated patients maintaining VA of 20/40 or better.

Positive pregnancy tests in a nongravid, premenopausal woman due to hCG beta-chain production by multiple myeloma.

Positive pregnancy test results occurred in a nongravid, premenopausal woman while she was receiving chemotherapy for multiple myeloma. We tested 2 hypotheses to account for this finding: (1) Heterophil antibodies caused positive interference in the immunoassays. (2) Genuine human chorionic gonadotropin (hCG) originated from a nonsyncytiotrophoblastic source. Paraprotein was eliminated as a source of positive interference because 3 different instruments with unique capture and signal antibodies gave similar results (83, 90, and 97 mIU/mL [83, 90, and 97 IU/L]). Human antimouse antibodies (HAMAs) were unlikely to cause positive interference because immunoreactivity was maintained after serum was treated to neutralize heterophil antibodies. Immunoassays performed after gel filtration of serum indicated that immunoreactivity was due to genuine hCG. The high-molecular-weight fraction (heterophil antibody) had 6 mIU/mL (6 IU/L) of hCG. The low-molecular-weight fraction (hCG) had 86 mIU/mL (86 IU/L) of hCG. Immunohistochemical stains revealed that myeloma cells expressed immunoreactive hCG. Hence, multiple myeloma caused positive pregnancy test results in a nongravid woman.

Formation of apolipoprotein AI-phosphatidylcholine core aldehyde Schiff base adducts promotes uptake by THP-1 macrophages.

OBJECTIVE: High-density lipoprotein (HDL) is believed to protect against development of atherosclerosis by inhibiting the accumulation of oxidized lipids in low-density lipoprotein (LDL). Paradoxically, HDL lipid is more susceptible to oxidation than LDL lipid. In the present study, we examined the effect of oxidized phospholipids on the uptake of HDL by macrophages. METHODS AND RESULTS: Oxidation of HDL increased formation of phosphatidylcholine core aldehydes that was paralleled by increased covalent binding of phospholipids to HDL protein from 0.96+/-0.44 to 8.5+/-1.76 phosphorus/HDL protein (mol/mol). Incubation of apolipoprotein AI with synthetically prepared phosphatidylcholine core aldehydes, 1-palmitoyl-2-[5-oxo]valeroyl-sn-glycero-3-phosphocholine or 1-palmitoyl-2-[9-oxo] nonanoyl-sn-glycero-3-phosphocholine, significantly increased the phosphorus:apolipoprotein AI ratio from 1.1+/-0.5 to 7.2+/-2.0 and from 0.9+/-0.6 to 8.5+/-0.8, respectively. The binding and uptake of phosphatidylcholine core aldehyde-apolipoprotein AI proteoliposomes, by THP-1 macrophages, was similar to that observed for oxidized HDL and oxidized LDL. CONCLUSION: We conclude that oxidation of HDL increased formation of phosphatidylcholine core aldehyde-apolipoprotein AI Schiff base adducts and enhanced uptake of oxidized HDL by THP-1 macrophages.

Paraoxonase-1 reduces monocyte chemotaxis and adhesion to endothelial cells due to oxidation of palmitoyl, linoleoyl glycerophosphorylcholine.

OBJECTIVE: High-density lipoprotein (HDL) is postulated to protect against the development of atherosclerosis, in part, by inhibiting the oxidation of low density lipoprotein (LDL) in the sub-endothelial space and thus inhibiting activation of the endothelium. The HDL-associated enzyme, paraoxonase-1, is proposed to be a major protective factor. However, HDL is also prone to oxidation when exposed to peroxynitrite and may therefore, once oxidized, have properties similar to oxidized LDL. METHODS AND RESULTS: We exposed human HDL to the peroxynitrite donor 3-morpholinosydnonimine and incubated oxidized HDL with human umbilical vein endothelial cells (HUVECs). Oxidized HDL increased monocyte binding (P<0.001) and enhanced chemotaxis (P<0.001). The major oxidized phospholipids were 1-palmitoyl (stearoyl)-2-[9-oxo]nanoyl(azelaoyl)-sn-glycero-phosphocholine, derived from linoleate-containing phosphatidylcholines, and 1-palmitoyl(stearoyl)-2-[5-oxo]valeroyl(glutaroyl)-sn-glycero-phosphocholine, derived from arachidonate-containing phosphatidylcholines. Incubation of HUVECs with synthetically prepared 1-palmitoyl-2-[9-oxo]nanoyl(azelaoyl)-sn-glycero-phosphocholine, or 1-palmitoyl-2-[5-oxo]valeroyl(glutaroyl)-sn-glycero-phosphocholine increased binding of monocytes (P<0.001) and chemotaxis (P<0.001). Purified paraoxonase-1 reduced monocyte adhesion and chemotaxis (P<0.001). CONCLUSIONS: (i) HDL can be a source of oxidatively-derived bioactive phospholipids; (ii) the fragmented phospholipids with a 9-carbon aldehyde or acid are as effective as a 5-carbon aldehyde or acid at inducing monocyte adhesion and chemotaxis; and (iii) paraoxonase-1 is effective at reducing the activity of these phospholipid oxidation products.

Multiple substrates for paraoxonase-1 during oxidation of phosphatidylcholine by peroxynitrite.

Paraoxonase (PON-1) is a high-density lipoprotein (HDL)-bound enzyme with activity toward multiple substrates. It hydrolyzes organic phosphate and aromatic carboxylic acid esters. It also inhibits accumulation of oxidized phospholipids in plasma lipoproteins by a mechanism yet to be determined. Therefore, we subjected apolipoprotein A-I proteoliposomes containing either 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine or 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine to oxidation by a peroxynitrite generator, SIN-1, in the presence and absence of purified PON-1. PON-1 modified the proportion of oxidation products without affecting the overall extent of PC oxidation. However, in the presence of PON-1, phosphatidylcholine isoprostanes were hydrolyzed to lysophosphatidylcholine. In addition, PON-1 hydrolyzed the phosphatidylcholine core aldehydes 1-palmitoyl-2-(9-oxo)nonanoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-(5-oxo)valeroyl-sn-glycero-3-phosphocholine to lysophosphatidylcholine. This hydrolysis was not affected by pefabloc, a serine esterase inhibitor. There was no detectable release of linoleate, arachidonate, or their hydroperoxy or hydroxy derivatives in the presence of PON-1. We conclude that PON-1 minimizes the accumulation of phosphatidylcholine oxidation products by the hydrolysis of phosphatidylcholine isoprostanes and core aldehydes to lysophosphatidylcholine with a serine esterase-independent mechanism.

Oxidative stress is markedly elevated in lecithin:cholesterol acyltransferase-deficient mice and is paradoxically reversed in the apolipoprotein E knockout background in association with a reduction in atherosclerosis.

Complete lecithin:cholesterol acyltransferase (LCAT) deficiency is a rare cause of severe hypoalphalipoproteinemia, but the affected subjects are surprisingly not particularly prone to premature coronary heart disease. We studied oxidative stress in lcat-/- mice and their cross-breed with apolipoprotein-E knockout mice (apoE-/-xlcat-/-) by measuring vascular ring superoxide production and plasma phospholipid (PL)-bound F2-isoprostane levels and their relationship with aortic atherosclerosis. Compared with wild type control (lcat+/+), lcat-/- and lcat+/- mice showed a 4.9- (p = 0.003) and a 2.1-fold (p = 0.04) increase in plasma PL-F2-isoprostane levels, respectively. There was also a 3.6- (p < 0.0001) and 2.9-fold (p = 0.003) increase in the area under the curve for the aortic ring superoxide excursion by lucigenin-derived chemiluminescence. A comparison of apoE-/-xlcat+/+ mice with wild type control mice showed a more modest 2.1- (p = 0.04) and 2.2-fold (p < 0.00001) increase in these respective markers. Surprisingly, the apoE-/-xlcat-/- mice showed a paradoxical normalization in both oxidation markers. Furthermore, by fast protein liquid chromatography separation, we observed an associated retention and redistribution of serum paraoxonase activities to the non-high density lipoprotein fractions in both the apoE-/-xlcat-/- and apoE-/-xlcat+/- mice. Aortic atherosclerotic lesions in male apoE-/-xlcat-/- and apoE-/-xlcat+/- mice were reduced by 52 (p = 0.02) and 24% (p = 0.46), respectively. Our data suggest that LCAT-deficient mice are associated with an increased oxidative stress that is paradoxically reversed in a hyperlipidemic background, possibly due to the redistribution of paraoxonase. This modulation of oxidative stress may in part contribute to the reduced atherosclerosis seen in the apoE-/- xlcat-/- mice.