Vitamin D and vitamin K1 as novel inhibitors of biofilm in Gram-negative bacteria.

BACKGROUND: The persistent surge in antimicrobial resistance represents a global disaster. The initial attachment and maturation of microbial biofilms are intimately related to antimicrobial resistance, which in turn exacerbates the challenge of eradicating bacterial infections. Consequently, there is a pressing need for novel therapies to be employed either independently or as adjuvants to diminish bacterial virulence and pathogenicity. In this context, we propose a novel approach focusing on vitamin D and vitamin K1 as potential antibiofilm agents that target Gram-negative bacteria which are hazardous to human health. RESULTS: Out of 130 Gram-negative bacterial isolates, 117 were confirmed to be A. baumannii (21 isolates, 17.9%), K. pneumoniae (40 isolates, 34.2%) and P. aeruginosa (56 isolates, 47.9%). The majority of the isolates were obtained from blood and wound specimens (27.4% each). Most of the isolates exhibited high resistance rates to ß-lactams (60.7-100%), ciprofloxacin (62.5-100%), amikacin (53.6-76.2%) and gentamicin (65-71.4%). Approximately 93.2% of the isolates were biofilm producers, with 6.8% categorized as weak, 42.7% as moderate, and 50.4% as strong biofilm producers. The minimum inhibitory concentrations (MICs) of vitamin D and vitamin K1 were 625-1250 µg mL-1 and 2500-5000 µg mL-1, respectively, against A. baumannii (A5, A20 and A21), K. pneumoniae (K25, K27 and K28), and P. aeruginosa (P8, P16, P24 and P27) clinical isolates and standard strains A. baumannii (ATCC 19606 and ATCC 17978), K. pneumoniae (ATCC 51503) and P. aeruginosa PAO1 and PAO14. Both vitamins significantly decreased bacterial attachment and significantly eradicated mature biofilms developed by the selected standard and clinical Gram-negative isolates. The anti-biofilm effects of both supplements were confirmed by a notable decrease in the relative expression of the biofilm-encoding genes cusD, bssS and pelA in A. baumannii A5, K. pneumoniae K28 and P. aeruginosa P16, respectively. CONCLUSION: This study highlights the anti-biofilm activity of vitamins D and K1 against the tested Gram-negative strains, which emphasizes the potential of these vitamins for use as adjuvant therapies to increase the efficacy of treatment for infections caused by multidrug-resistant (MDR) strains and biofilm-forming phenotypes. However, further validation through in vivo studies is needed to confirm these promising results.

Post-bariatric pregnancy is associated with vitamin K1 deficiency, a case control study.

BACKGROUND: Maternal obesity is associated with adverse outcome for pregnancy and childbirths. While bariatric surgery may improve fertility and reduce the risk of certain pregnancy-related complications such as hypertension and gestational diabetes mellitus, there is a lack of evidence on the optimal nutritional monitoring and supplementation strategies in pregnancy following bariatric surgery. We aimed to assess the impact of bariatric surgery on micronutrients in post-bariatric pregnancy and possible differences between gastric bypass surgery and sleeve gastrectomy. METHODS: In this prospective case control study, we recruited 204 pregnant women (bariatric surgery n = 59 [gastric bypass surgery n = 26, sleeve gastrectomy n = 31, missing n = 2] and controls n = 145) from Akershus university hospital in Norway. Women with previous bariatric surgery were consecutively invited to study participation at referral to the clinic for morbid obesity and the controls were recruited from the routine ultrasound screening in gestational week 17-20. A clinical questionnaire was completed and blood samples were drawn at mean gestational week 20.4 (SD 4.5). RESULTS: The women with bariatric surgery had a higher pre-pregnant BMI than controls (30.8 [SD 6.0] vs. 25.2 [5.4] kg/m2, p < 0.001). There were no differences between groups regarding maternal weight gain (bariatric surgery 13.3 kg (9.6) vs. control 14.8 kg (6.5), p = 0.228) or development of gestational diabetes (n = 3 [5%] vs. n = 7 [5%], p = 1.000). Mean levels of vitamin K1 was lower after bariatric surgery compared with controls (0.29 [0.35] vs. 0.61 [0.65] ng/mL, p < 0.001). Multiadjusted regression analyses revealed an inverse relationship between bariatric surgery and vitamin K1 (B -0.26 ng/mL [95% CI -0.51, -0.04], p = 0.047) with a fivefold increased risk of vitamin K1 deficiency in post-bariatric pregnancies compared with controls (OR 5.69 [1.05, 30.77] p = 0.044). Compared with sleeve gastrectomy, having a previous gastric bypass surgery was associated with higher risk of vitamin K1 deficiency (OR 17.1 [1.31, 223.3], p = 0.030). CONCLUSION: Post-bariatric pregnancy is negatively associated with vitamin K1 with a higher risk of vitamin K1 deficiency in pregnancies after gastric bypass surgery compared with after sleeve gastrectomy. Vitamin K1 deficiency in post-bariatric pregnancy have potential risk of hypocoaguble state in mother and child and should be explored in future studies.

An emerging epidemic of allergic contact dermatitis due to phytonadione epoxide (oxidised vitamin K1).

BACKGROUND: Reports of allergic contact dermatitis (ACD) to phytonadione epoxide (PE) in cosmetics suggest that PE is as powerful a sensitiser as its parent compound phytonadione. OBJECTIVE: To evaluate a case series of ACD to PE in Spain. METHODS: We reviewed the records of 20 patients with ACD to cosmetics containing PE diagnosed across Spain between January 2019 and June 2023. RESULTS: All 20 patients developed patch test (PT) or repeated open application test (ROAT) reactions to cosmetics containing PE. All involved women with eyelid eczema. PT or ROAT with PE preparations were positive in 17/20 (85%). PE at 1%, 5%, 10% and 20% in pet. was patch-tested in 8/17, 14/17, 11/17 and 8/17 patients; being positive in 6/8 (75%), 13/14 (92.85%), 11/11 (100%) and 8/8 (100%), respectively. CONCLUSION: Regulators should, not only ban the specific dangerous cosmetic ingredients, but also consider to ban or keep under close surveillance those closely related products or derivatives that might potentially cause similar harmful effects. PTs with PE are suggested to be performed at a 5% concentration in pet. Higher concentrations (10% pet.) should be tested whenever PTs with 5% pet. PE are negative.

Quantitative Study of Vitamin K in Plants by Pressurized Liquid Extraction and LC-MS/MS.

The health-promoting properties of vitamin K stimulate the growing interest in this compound, which translates into the development of new analytical methodologies for its determination. New, more efficient methods of its isolation are sought, paying increasingly more attention to the methods within currently available extraction techniques that, owing to the optimization of the process, not only increase the extraction efficiency but are also economical and environmentally friendly. This article proposes a procedure for the extraction and analysis of one of the vitamin K vitamers, i.e., vitamin K1, using PLE and LC-MS/MS. It has been shown that the PLE technique can be optimized with a mathematical model-accelerating and reducing the costs of the extraction process-which, together with process automation, bodes well for industrial applications. The optimized process was used to extract vitamin K1 from various vegetables, showing very different contents of the test compound ranging from 1.22 to 114.30 µg/g dry weight for avocado and spinach, respectively. In addition, by showing the effect of water within the material subjected to extraction on the variable yield of vitamin K1, attention was drawn to the need to standardize the analytical methods used in assessing the quality of food products.

Antioxidant Properties of Green Plants with Different Vitamin K Contents.

Vitamin K, as a natural protector of our blood, bones, kidneys, and brain, is essential for human health. It is also considered an effective anti-aging agent with comprehensive biological effects, including antifungal, antibacterial, anti-inflammatory, analgesic, and even antioxidant properties. Of these, the least is known about the antioxidant properties of natural vitamin K. To fill this gap, this study compared the antioxidant properties of extracts obtained from commonly consumed green plants with different vitamin K contents with the activity of vitamin K standard solutions at concentrations corresponding to the vitamin K contents in the extracts. Various measurement methods were used in the research (i.e., DPPH, FRAP, CUPRAC, and the ß-carotene bleaching test). Among the tested methods, the ß-carotene bleaching test is the most sensitive in the assessment of this unusual compound. In light of the data presented, the antioxidant response of vitamin K alone is dose-dependent. However, in extracts, the activity of this compound is modulated by other constituents present in them. As a result, the activity does not always correlate with vitamin K content. The presented data supplement the knowledge about the antioxidant properties with the contribution resulting from the presence of vitamin K in green plant extracts.

Development of a liquid chromatography mass spectrometry method for the determination of vitamin K1, menaquinone-4, menaquinone-7 and vitamin K1-2,3 epoxide in serum of individuals without vitamin K supplements.

OBJECTIVES: Vitamin K and metabolites have a beneficial role in blood coagulation, bone metabolism and growth. However, the determination of vitamin K concentrations in the blood in patients consuming a diet with naturally occurring vitamin K is currently challenging. We aim to develop a cost-effective and rapid method to measure vitamin K metabolites with potential application for clinics and research. METHODS: We developed a simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of vitamin K1, menaquinone-4 (MK-4), menaquinone-7 (MK-7) and vitamin K1-2,3 epoxide in human serum and validated the method in a study cohort of 162 patients tested for carbohydrate malabsorption and in 20 patients with oral phenprocoumon intake. RESULTS: The overall precision (CVs) ranged between 4.8 and 17.7% in the specified working range (0.06-9.0 nmol/L for all analytes except for MK-7 with 0.04-6.16 nmol/L). In the malabsorption cohort samples, measured values were obtained for all different vitamin K metabolites except for vitamin K1-2,3 epoxide. This metabolite could be detected only in patients with phenprocoumon intake. The good performance of the method is especially achieved by the interaction of three factors: the use of lipase in the sample preparation, the use of an atypical fluorinated reversed phase column, and a logarithmic methanol gradient. CONCLUSIONS: The described method is able to determine the concentration of four vitamin K metabolites in a time-efficient, simple and cost-effective manner. It can be suitable for both routine clinics and research.

New Insight into Vitamins E and K1 as Anti-Quorum-Sensing Agents against Pseudomonas aeruginosa.

Today, antivirulence compounds that attenuate bacterial pathogenicity and have no interference with bacterial viability or growth are introduced as the next generation of antibacterial agents. However, the development of such compounds that can be used by humans is restricted by various factors, including the need for extensive economic investments, the inability of many molecules to penetrate the membrane of Gram-negative bacteria, and unfavorable pharmacological properties and cytotoxicity. Here, we take a new and different look into two frequent supplements, vitamin E and K1, as anti-quorum-sensing agents against Pseudomonas aeruginosa, a pathogen that is hazardous to human life and responsible for several diseases. Both vitamins showed significant anti-biofilm activity (62% and 40.3% reduction by vitamin E and K1, respectively), and the expression of virulence factors, including pyocyanin, pyoverdine, and protease, was significantly inhibited, especially in the presence of vitamin E. Cotreatment of constructed biofilms with these vitamins plus tobramycin significantly reduced the number of bacterial cells sheltered inside the impermeable matrix (71.6% and 69% by a combination of tobramycin and vitamin E or K1, respectively). The in silico studies, besides the similarities of chemical structures, reinforce the possibility that both vitamins act through inhibition of the PqsR protein. This is the first report of the antivirulence and antipathogenic activity of vitamin E and K1 against P. aeruginosa and confirms their potential for further research against other multidrug-resistant bacteria.

Randomized, placebo-controlled trial of orally administered vitamin K1 for warfarin-associated coagulopathy in Chinese patients with mechanical heart valves.

PURPOSE: Warfarin-associated coagulopathy commonly occurs in patients undergoing treatment with this anticoagulant. This trial aimed to determine the efficacy of using low-dose orally administered vitamin K1 to lower international normalized ratio (INR) values into the target range in a cohort of Chinese patients with mechanical heart valves. METHODS: This was a double-blind, placebo-controlled, randomized trial. Chinese patients with mechanical heart valves who were undergoing warfarin treatment and who had INR values from 4.0 to 10.0 without bleeding were the subjects of this study. These patients were randomized into two treatment groups and were orally administered either vitamin K1 (2.5 mg) or placebo. Warfarin was discontinued in both groups until INR values were ≤ 2.5. INR values on the day following treatment were the primary study outcome, with INR values on the following days and adverse clinical events over a 3-month follow-up serving as secondary study outcomes. RESULTS: In total, 80 patients were enrolled in the present study, and 40 patients each were assigned to the placebo and vitamin K1 treatment groups. Patients administered vitamin K1 exhibited a quick reduction in INR values relative to patients administered placebo (29 of 40 [72.5%] vs. 0 of 44 [0%] patients exhibiting INR values from 1.5-2.5 on the day following treatment, respectively, p = 0.000). Lower bleeding incidence was observed among patients administered vitamin K1 relative to those administered placebo during follow-up (4 [10%] vs. 12 [30%] patients, respectively, p = 0.045). There were no instances of thromboembolic complications or warfarin resistance in either group. CONCLUSION: Low-dose oral vitamin K1 can be effectively administered to Chinese patients with mechanical heart valves taking warfarin to rapidly reduce elevated INR values.

Determination of pharmacokinetic parameters of vitamin K1 in rats after an intravenous infusion.

Pharmacokinetic parameters of vitamin K1 have a large range of values in different literature. The aim of this study was to determine the pharmacokinetic parameters of vitamin K1 following post-constant speed intravenous infusion (PCSII) to provide rational pharmacokinetic parameters of vitamin K1 and compare these with results of noncompartmental analysis following intravenous injection (IV). After 15 hours intravenous infusion of vitamin K1 in rats, the logarithmic concentration-time curve of vitamin K1 was fit to a linear equation following PCSII (R2  = 0.9599 ± 0.0096). Then, half-time (T1/2 ), apparent volume of distribution (Vd ), and clearance rate (CL) were estimated successively. T1/2 of vitamin K1 was 4.07 ± 0.41 hour, CL was 89.47 ± 3.60 mL/h, and Vd was 525.38 ± 54.45 mL in rats following PCSII. There was no significant difference in pharmacokinetic parameters of vitamin K1 among different sampling times. For noncompartmental analysis, T1/2 and mean residence time (MRTINF ) for a sampling duration of 6h were shorter than those of 12 hours or 24 hours sampling duration following IV (P < .05, P < .01). In addition, T1/2 of vitamin K1 was obviously different from MRT-equated half-time (T1/2,MRT )(P < .05). Vd and CL of vitamin K1 following PCSII were larger than those following IV based on noncompartmental analysis (P < .01). The results demonstrated that drug distribution in the body was balanced and the Napierian logarithmic concentration-time curve of vitamin K1 fit to a linear equation following PCSII. Vitamin K1 has a long T1/2 and a relatively large Vd following PCSII.

Extraction and Determination of Vitamin K1 in Foods by Ultrasound-Assisted Extraction, SPE, and LC-MS/MS.

Vitamin K1 is one of the important hydrophobic vitamins in fat-containing foods. Traditionally, lipase is employed in the determination of vitamin K1 to remove the lipids, which makes the detection complex, time-consuming, and insensitive. In this study, the determination of vitamin K1 in fat-containing foods was developed based on ultrasound-assisted extraction (UAE), solid-phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The optimal conditions for extraction of vitamin K1 were material-liquid ratio of 1:70 (g/mL), extraction temperature of 50 °C, extraction power of 700 W, extraction time of 50 min, material-wash fluid ratio of 1:60 (g/mL), and 8 mL of hexane/anhydrous ether (97:3, v/v) as the elution solvent. Then, vitamin K1 was analyzed on a ZORBAX SB-C18 column (50 mm × 2.1 mm, 1.8 µm) by gradient elution with water (0.01% formic acid) and methanol (0.01 formic acid + 2.5 mmol/L ammonium formate) as the mobile phase. The limit of detection (LOD) and limit of quantification (LOQ) were 0.05 and 0.16 µg/kg, respectively. Calibration curve was linear over the range of 10-500 ng/mL (R2 > 0.9988). The recoveries at three spiked levels were between 80.9% and 119.1%. The validation and application indicated that the proposed method was simple and sensitive in determination of vitamin K1 in fat-containing foods.

Vitamin K Deficiency Bleeding: An Ounce of Prevention.

Vitamin K is a fat-soluble vitamin essential for the formation of factors in the clotting cascade. Newborns are born with insufficient levels of vitamin K, resulting in high risk for vitamin K deficiency bleeding (VKDB). Vitamin K deficiency bleeding can occur in the first week of life ("classic" VKDB) and also between 2 weeks and 3 months of age ("late" VKDB). Vitamin K deficiency bleeding can present as bleeding in the skin or gastrointestinal tract, with as many as half of affected neonates experiencing intracranial bleeding. A single intramuscular injection of vitamin K effectively prevents both classic and late VKDB. Although intramuscular vitamin K is safe and effective, VKDB has reemerged because of decreased utilization. Parents refuse intramuscular vitamin K for a variety of reasons, including a disproven association with childhood cancer, the desire to avoid exposure to additives, and valid concerns about early neonatal pain. Many parents request oral vitamin K, an inferior alternative strategy that requires multiple doses utilizing products not designed for neonatal oral administration. In this setting, health care professionals must understand the epidemiology of VKDB and compassionately counsel parents to assuage concerns. Delivery of intramuscular vitamin K to all newborns remains a public health imperative, benefitting thousands of infants annually.

[Simultaneous determination of 25-hydroxyvitamin D and vitamin K_1 in serum by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for analysis of 25-hydroxylvitamin D_2(25(OH)D_2), 25-hydroxylvitamin D_3(25(OH)D_3)and vitamin K_1 in serum by ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS), which can be applied in diagnosis of vitamin deficiency and estimation on the nutritional status of people. METHODS: Serum samples mixed with d_6-25(OH)D_3, d_7-vitamin K_1(internal standard)were precipitated with acetonitrile and extracted with n-hexane. The sample solution was separated using BEH C_(18) column(2. 1 mm×100 mm, 1. 7 µm) with gradient elution using methanol-water containing 0. 1% formic acid as mobile phase. The target molecule was detected in positive electrospray ionization(ESI~+) and multiple reaction monitoring. RESULTS: The concentration of 25(OH)D_2, 25(OH)D_3 and vitamin K_1 showed good linearity in the range 5. 0-75. 0 ng/mL, 2. 0-81. 5 ng/mL and 0. 3-12. 0 ng/mL, respectively, with the correlation coefficients greater than 0. 995. The limits of detection(LOD) of 25(OH)D_2, 25(OH)D_3 and vitamin K_1 were 1, 0. 25 and 0. 1 ng/mL, and the limits of quantification(LOQ) for 25(OH)D_2, 25(OH)D_3 and vitamin K_1were 3, 0. 75 and 0. 3 ng/mL, respectively. The recoveries of three levels in the matrix were 98. 5%-104. 3%, the relative standard deviation(RSD) were all less than 5. 0%(n=6). CONCLUSION: An UPLC-MS/MS method for analysis of 25(OH)D_2, 25(OH)D_3 and vitamin K_1 in serum is sensitive, rapid, accurate and suitable for the nutritional surveillance of vitamin D and K_1 in the population.

A potential biotechnological process for the sustainable production of vitamin K1.

The primary objective of this review is to propose an approach for the biosynthesis of phylloquinone (vitamin K1) based upon its known sources, its role in photosynthesis and its biosynthetic pathway. The chemistry, health benefits, market, and industrial production of vitamin K are also summarized. Vitamin K compounds (K vitamers) are required for the normal function of at least 15 proteins involved in diverse physiological processes such as coagulation, tissue mineralization, inflammation, and neuroprotection. Vitamin K is essential for the prevention of Vitamin K Deficiency Bleeding (VKDB), especially in neonates. Increased vitamin K intake may also reduce the severity and/or risk of bone fracture, arterial calcification, inflammatory diseases, and cognitive decline. Consumers are increasingly favoring natural food and therapeutic products. However, the bulk of vitamin K products employed for both human and animal use are chemically synthesized. Biosynthesis of the menaquinones (vitamin K2) has been extensively researched. However, published research on the biotechnological production of phylloquinone is restricted to a handful of available articles and patents. We have found that microalgae are more suitable than plant cell cultures for the biosynthesis of phylloquinone. Many algae are richer in vitamin K1 than terrestrial plants, and algal cells are easier to manipulate. Vitamin K1 can be efficiently recovered from the biomass using supercritical carbon dioxide extraction.

Vitamin K1 Inhibition of Renal Crystal Formation through Matrix Gla Protein in the Kidney.

BACKGROUND AND OBJECTIVES: Vitamin K (VK) plays a major role in modifying the binding of calcium in bones and blood vessels. Understanding the effect of VK on crystal formation in the kidney would contribute to advancing the treatment and prevention of kidney stones. METHODS: Rats were treated with vitamin K1 (VK1) for 8 weeks. VK1 levels were detected and crystal formation were observed. HK2 cells were exposed to calcium oxalate monohydrate crystals. Apoptosis and cell viability were detected. Crystal deposition was analyzed using atomic absorption assay. The adenovirus vectors expressing matrix Gla protein (MGP) and siMGP were constructed to elucidate the effect and mechanism of VK1 on crystal formation. MGP expression in vivo and in vitro was analyzed by Western blot. The mRNA levels of monocyte chemoattractant protein-1 (MCP-1) and collagen I was measured by semiquantitative RT-PCR. RESULTS: The concentrations of VK1 in whole blood and kidney tissues rose under treatment with VK1. Crystal formation was inhibited from the second to the 6th week, the frequency and quality of crystal formation decreased significantly, and the location of crystal formation was limited to a greater extent in the rats treated by VK1 compared to the control group. Warfarin treatment in the crystals-exposed HK2 cells significantly increased the number of crystals adhering to cells and the number of apoptotic cells and reduced cell viability. VK1 treatment reversed warfarin's above influence. VK1 inhibited the upregulations of MCP-1 and collagen I in kidney tissues under crystal load. VK1 treatment increased MGP expression in vivo and in vitro, and MGP is necessary for VK1 to play a role in crystal deposition in cells. CONCLUSIONS: VK1 treatment can inhibit the formation of renal crystals in vivo. VK1 increases MGP expression and functions through MGP to reduce crystal deposition in cells and provide cell protection. Our findings suggest that VK1 treatment could be a potential strategy for the treatment and prevention of nephrolithiasis.

Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease.

Vitamin K is an essential bioactive compound required for optimal body function. Vitamin K can be present in various isoforms, distinguishable by two main structures, namely, phylloquinone (K1) and menaquinones (K2). The difference in structure between K1 and K2 is seen in different absorption rates, tissue distribution, and bioavailability. Although differing in structure, both act as cofactor for the enzyme gamma-glutamylcarboxylase, encompassing both hepatic and extrahepatic activity. Only carboxylated proteins are active and promote a health profile like hemostasis. Furthermore, vitamin K2 in the form of MK-7 has been shown to be a bioactive compound in regulating osteoporosis, atherosclerosis, cancer and inflammatory diseases without risk of negative side effects or overdosing. This review is the first to highlight differences between isoforms vitamin K1 and K2 by means of source, function, and extrahepatic activity.

The effects of vitamin K1 and vitamin K2 on the proliferation, cytokine production and regulatory T-cell frequency in peripheral blood mononuclear cells of paediatric atopic dermatitis patients.

We estimated the pharmacological efficacy of vitamin K1 (VK1 ) and VK2 on the mitogen-activated peripheral blood mononuclear cells (PBMCs) of paediatric atopic dermatitis (AD) patients. VK2 suppressed the in vitro proliferation of T-cell mitogen-activated PBMCs of AD patients. In contrast, VK1 had little effect on the PBMC proliferation. The IL-2 production from the activated PBMCs of AD patients significantly increased (P < .05), while the production significantly decreased by 100 µmol L-1 VK2 (P < .01). In addition, 100 µmol L-1 VK2 reduced the percentage of CD4+ and CD4+CD25+ cells in PBMCs. These results suggest that VK2 can modulate T-cell function in PBMCs of AD patients.

Development of a kelp powder (Thallus laminariae) Standard Reference Material.

A Standard Reference Material (SRM) of seaweed, SRM 3232 Kelp Powder (Thallus laminariae) has been developed to support food and dietary supplement measurements in compliance with the Food Safety Modernization Act (FSMA) and the Dietary Supplement Health and Education Act of 1994 (DSHEA). The material was characterized for nutritional minerals, arsenic species, isomers of vitamin K1, proximates, and toxic elements. Kelp is a rich source of vitamins and minerals, and it is an excellent source of dietary iodine. Kelp also contains a large amount of arsenic, which is toxic as inorganic species but much less so as organic species. To capture the dietary profile of kelp, certified values were issued for As, Ca, Cd, Cr, Cu, Fe, Hg, I, K, Mg, Mn, Mo, Na, Pb, and Zn. Reference values for proximates were assigned. For the first time, a certified value for iodine, reference values for isomers of vitamin K1, and reference values for arsenic species including arsenosugars were assigned in a seaweed. SRM 3232 fills a gap in Certified Reference Materials (CRMs) needed for quality assurance and method validation in the compositional measurements of kelp and similar seaweeds used as food and as dietary supplements. Graphical Absract Arsenic species and isomers of vitamin K1 were determined in the development of SRM 3232 Kelp Powder (Thallus laminariae).

Vitamin K1 and Vitamin K2 immunopharmacological effects on the peripheral lymphocytes of healthy subjects and dialysis patients, as estimated by the lymphocyte immunosuppressant sensitivity test.

WHAT IS KNOWN AND OBJECTIVE: Renal transplant recipients receive immunosuppressive therapy to prevent acute rejection. We evaluated the immunopharmacological efficacy of vitamin K1 (VK1) and vitamin K2 (VK2) on T-cell mitogen-activated-peripheral lymphocytes of dialysis patients and healthy subjects. METHODS: The effects of VK1 and VK2 on the T-cell mitogen-stimulated proliferation of peripheral blood mononuclear cells (PBMCs) obtained from 12 healthy subjects and 12 dialysis patients were estimated. Seven cytokines produced from the activated PBMCs were measured by a BD Cytometric Beads Array kit. Regulatory T cells (Tregs) in PBMCs were analysed as CD4 + CD25 + FoxP3 +  lymphocytes by flow cytometry. RESULTS: VK2 dose-dependently suppressed the concanavalin A-stimulated proliferation of PBMCs from healthy subjects and dialysis patients, whereas VK1 had no significant effect on the PBMC proliferation. VK1 and VK2 did not influence the production of most of the Th1/Th2/Th17 cytokines from the activated PBMCs of these subjects, although VK2 increased the IL-4 production from PBMCs of healthy subjects. The Treg percentages in the PBMCs of dialysis patients were markedly decreased compared to healthy PBMCs after the treatment with relatively low concentrations of VK2. WHAT IS NEW AND CONCLUSION: The present data suggest that VK2 has immunosuppressive efficacy. VK2 may enhance the immunosuppressive efficacies of glucocorticoids while preventing osteoporosis caused by glucocorticoids.

Increased matrix stiffness promotes tumor progression of residual hepatocellular carcinoma after insufficient heat treatment.

Aggravated behaviors of hepatocellular carcinoma (HCC) will occur after inadequate thermal ablation. However, its underlying mechanisms are not fully understood. Here, we assessed whether the increased matrix stiffness after thermal ablation could promote the progression of residual HCC. Heat-treated residual HCC cells were cultured on tailorable 3D gel with different matrix stiffness, simulating the changed physical environment after thermal ablation, and then the mechanical alterations of matrix stiffness on cell phenotypes were explored. Increased stiffness was found to significantly promote the proliferation of the heat-treated residual HCC cells when the cells were cultured on stiffer versus soft supports, which was associated with stiffness-dependent regulation of ERK phosphorylation. Heat-exposed HCC cells cultured on stiffer supports showed enhanced motility. More importantly, vitamin K1 reduced stiffness-dependent residual HCC cell proliferation by inhibiting ERK phosphorylation and suppressed the in vivo tumor growth, which was further enhanced by combining with sorafenib. Increased matrix stiffness promotes the progression of heat-treated residual HCC cells, proposing a new mechanism of an altered biomechanical environment after thermal ablation accelerates HCC development. Vitamin K1 plus sorafenib can reverse this protumor effect.

Warfarin Poisoning with Delayed Rebound Toxicity.

BACKGROUND: Intentional poisoning with warfarin is not the same as over-anticoagulation, for which guidelines exist. The coagulopathy resulting from a warfarin overdose is reversed with vitamin K1, the dose and timing of which is often guided by experience with the management of over-anticoagulation with warfarin therapy, rather than acute overdose. CASE REPORT: We report a case of a 50-year-old man who ingested an unknown amount of his warfarin, venlafaxine, and paracetamol. He presented with an international normalized ratio (INR) of 2.5, which steadily increased over 24 h to 7, despite receiving an initial 1 mg of vitamin K1. He was then treated with 5 mg vitamin K1, and once the INR returned to 4.5, 40 h post ingestion, he was discharged home. He was also treated with a full course of acetylcysteine for the paracetamol overdose. The following day his INR rebounded to 8.5 and he suffered a spontaneous epistaxis requiring readmission; he was treated with low titrated doses of vitamin K1. The warfarin concentration was 74.6 µg/mL 26 h post ingestion and decreased to 3.7 µg/mL over 72 h. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Our case highlights the risk of a rebound elevated INR even 3 days after acute warfarin overdose despite treatment with vitamin K1. Understanding the pharmacokinetics of vitamin K1 in comparison with warfarin, repeat INR testing, and continued treatment with oral vitamin K1 may help avoid complications of rebound coagulopathy in warfarin overdose.