Progress in vitamin C biosynthesis related dehydrogenases / 生物工程学报

Vitamin C is an essential vitamin for human beings. It has a huge market in the fields of food and pharmaceuticals. 2-keto-L-gulonic acid is an important precursor to produce vitamin C by microbial fermentation in industrial. In microbial fermentations, the L-sorbose pathway and the D-gluconate pathway have been the focus of research because of high yield. This article aims at stating recent research progress in dehydrogenases related to biosynthesis of vitamin C in the L-sorbose pathway and the D-gluconate pathway. The properties of dehydrogenase in terms of localization, substrate specificity, cofactors, and electron transport carrier are elaborated. And then, the main problems and strategies are reviewed in the L-sorbose pathway and in the D-gluconate pathway. Finally, future research on the dehydrogenases in the biosynthesis of vitamin C through L-sorbose pathway and D-gluconate pathway is discussed.

Atividade in vitro do extrato etanólico de própolis e do digluconato de clorexidina sobre as espécies de Candida isoladas da mucosa bucal de pacientes internados em Unidade de Terapia Intensiva (UTI) / In vitro activity of ethanolic extract of propolis and chlorhexidine digluconate on Candida species isolated from the oral mucosa of patients hospitalized in the Intensive Care Unit (ICU)

Avaliou-se a atividade dos extratos de própolis e digluconato de clorexidina em Candida sp isoladas da mucosa bucal de pacientes em UTI. Foram determinadas as concentrações fungicidas mínimas (CFM) e comparadas, nas doses sub-inibitórias, à produção de exoenzimas proteinase e fosfolipase e formação de franjas. Em 72 isolados foram avaliadas a atividade antifúngica pela técnica de microdiluição em série, na “base 2”, a produção das exoenzimas proteinase e fosfolipase, e a formação de franjas, antes e após a exposição às própolis e clorexidina. Dos 72 isolados, 53 eram C. albicans, 11 C. tropicalis, quatro C. guilhermondii e quatro sugestivas de C. dubliniensis. CFM 90% do extrato de própolis foi de 5% para C. albicans, 20% C. tropicalis, 0,625% C. guilhermondii e 0,312% sugestivas de C. dubliniensis. CFM 90% da clorexidina foi de 0,0018% para C. albicans, 0,012% C. tropicalis, de 0,0018% C. guilhermondii e de 0,00375% sugestivas de C. dubliniensis. Ocorreu inibição das exoenzimas e franjas, em ambos os produtos. Apesar da inibição da clorexidina ser menor que a da própolis, seu uso diário não causa efeitos colaterais indesejáveis como manchas nos dentes e na língua, perda do paladar e sensação de queimação na mucosa bucal.

The activity of propolis extract and chlorhexidine digluconate on Candida sp isolated from oral mucosa of patients in ICU was evaluated. The minimum fungicidal concentrations (MFC) were determined, and also the production of proteinase and phospholipase exoenzymes and the fringe formation. Seventy-two isolates were used and identified by the API 20C AUX® System. The antifungal activity was evaluated by “at base 2” serial microdilution technique. Also the exoenzymes production (proteinase and phospholipase), the fringes formation, before and after being exposed to propolis and chlorhexidine, were analysed. Of 72 isolates, 53 were C. albicans, 11 C. tropicalis, four C. guilhermondii and four suggestive C. dubliniensis. The MFC 90% of propolis extract was 5% C. albicans, 20% C. tropicalis, 0.625% C. guilhermondii; and 0.312% suggestive of C. dubliniensis. MFC 90% of chlorhexidine was 0.0018% C. albicans, 0.012% C. tropicalis, 0.0018% C. guilhermondii and 0.00375% suggestive of C. dubliniensis. The inhibition of exoenzymes and fringes occurred in the both products. Although the inhibition of chlorhexidine is lower than that showed by propolis, its daily use neither cause undesirable side effects as blemishes on the teeth and tongue, nor the loss of the taste and the burning sensation in the oral mucosa.

Effectiveness of a new non-hydrogen peroxide bleaching agent after single use - a double-blind placebo-controlled short-term study

Abstract Tooth whitening represents perhaps the most common aesthetic procedure in dentistry worldwide. The efficacy of bleaching depends on three aspects: bleaching agent, bleaching method, and tooth color. Objective: This in vivo study aimed to examine whitening effects on frontal teeth of the upper and lower jaws using an over-the-counter (OTC) non-hydrogen peroxide bleaching agent in comparison to a placebo after one single use. Material and methods: Forty subjects (25 female; 15 male) participated in this double-blind randomized placebo-controlled trial. The subjects were randomly allocated to two groups (n=20). The test group received the OTC product (iWhite Instant) and the placebo group received an identically composed product except for the active agents. Each subject was treated with a prefilled tray containing iWhite Instant or the placebo for 20 minutes. The tooth shade of the front teeth (upper and lower jaws) was assessed before (E_0), immediately after (E_1) and 24 h after treatment (E_2), using a shade guide (VITA classical). Statistical testing was accomplished using the Mann-Whitney U test (p<0.001). The dropout rate was 0%. Results: There were no significant differences at E_0 between placebo and test groups regarding the tooth color. Differences in tooth color changes immediately after (ΔE1_0) and 24 h after treatment (ΔE2_0) were calculated for both groups. The mean values (standard deviations) of tooth color changes for ΔE1_0 were 2.26 (0.92) in the test group and 0.01 (0.21) in the placebo group. The color changes for ΔE2_0 showed mean values of 2.15 (1.10) in the test group and 0.07 (0.35) in the placebo group. For ΔE1_0 and ΔE2_0 significant differences were found between the groups. Conclusion: In this short-term study, the results showed that a non-hydrogen peroxide bleaching agent has significant whitening effects immediately and 24 h after a single-use treatment.

Effect of piglet castration with nonsurgical sterilant on the zootechnical performance and pork carcass quality / Efeito da castração de leitões com esterilizante não cirúrgico no desempenho zootécnico e na qualidade da carcaça suína

A non-surgical sterilant (NSS) was used with the objective of assessing the zootechnical performance, carcass and meat quality, and hormone levels. 90 male piglets were selected with birthweights varying between 1.5kg to 2.0kg. The control group was constituted of 45 males castrated by the conventional surgical method, at the seventh day of age, and the treated group was constituted of 45 males castrated with NSS (active principle of zinc gluconate in the concentration of 26.2mg/mL associated to the dimethyl sulfoxide at 0.5%), with the application of the first dose on the seventh day of age and the second dose on the fourteenth day of age. The zootechnical assessments were carried out on the farm and consisted: weight gain in the periods per animal and feed conversion. The slaughter of the animals and the assessment of the carcass and meat quality and hormone levels were carried out in a slaughterhouse and the municipality of Campinas (SP). The study demonstrated that the use of NSS was a viable alternative in relation to the zootechnical performance and the carcass quality. In relation to the meat quality there was no significant difference in the majority of the assessed parameters.(AU)

Foi utilizado esterilizante não cirúrgico (ENC) com o objetivo de se avaliar o desempenho zootécnico e a qualidade de carcaça, de carne e de níveis hormonais. Foram selecionados 90 leitões machos de peso entre 1,5kg e 2,0kg ao nascimento. O grupo controle foi constituído por 45 machos castrados pelo método cirúrgico convencional, ao sétimo dia de idade, e o grupo tratado foi constituído por 45 machos castrados com ENC (princípio ativo de gluconato de zinco na concentração de 26,2mg/mL associado ao dimetil sulfóxido a 0,5%), com primeira dose de aplicação ao sétimo dia de idade e a segunda dose ao 14° dia de idade. As avaliações consistiram de: ganho de peso nos períodos por animal e conversão alimentar. O abate dos animais e a avaliação da carne e de níveis hormonais foram realizados em um frigorífico, na cidade de Campinas (SP). O uso de ENC foi uma alternativa viável em relação ao desempenho zootécnico e à qualidade da carcaça. Em relação à qualidade da carne, não houve diferença significativa na maioria dos parâmetros avaliados.(AU)

Optimization of the fermentation conditions for 5-keto-D-gluconic acid production / 生物工程学报

Gluconobacter oxydans converts glucose to gluconic acid and subsequently to 5-keto-D-gluconic acid (5-KGA), a precursor of industrially important L(+)-tartaric acid. To increase the yield of 5-KGA, fermentation conditions of 5-KGA production was optimized. Under the optimum medium and culture conditions in the shake flask, the highest 5-KGA production reached 19.7 g/L, increased by 43.8% after optimization. In a 5-L bioreactor, the pH was controlled at 5.5 and dissolved oxygen (DO) at 15%, 5-KGA production reached 46.0 g/L, raised at least 1.3 times than in the shake flask. Glucose feeding fermentation process was further developed, and the highest 5-KGA production of 75.5 g/L with 70% of yield was obtained, 32.0% higher than the highest reported value. Therefore, this newly developed fermentation process provided a practical and effective alternative for the commercial production of 5-KGA, and further of L(+)-tartaric acid.

Effects of carbon and nitrogen sources on 5-keto-gluconic acid production / 生物工程学报

Gluconobacter oxydans is known to oxidize glucose to gluconic acid (GA), and subsequently, to 2-keto-gluconic acid (2KGA) and 5-keto-gluconic acid (5KGA), while 5KGA can be converted to L-(+)-tartaric acid. In order to increase the production of 5KGA, Gluconobacter oxydans HGI-1 that converts GA to 5KGA exclusively was chosen in this study, and effects of carbon sources (lactose, maltose, sucrose, amylum and glucose) and nitrogen sources (yeast extract, fish meal, corn steep liquor, soybean meal and cotton-seed meal) on 5KGA production were investigated. Results of experiment in 500 mL shake-flask show that the highest yield of 5KGA (98.20 g/L) was obtained using 100 g/L glucose as carbon source. 5KGA reached 100.20 g/L, 109.10 g/L, 99.83 g/L with yeast extract, fish meal and corn steep liquor as nitrogen source respectively, among which the optimal nitrogen source was fish meal. The yield of 5KGA by corn steep liquor is slightly lower than that by yeast extract. For the economic reason, corn steep liquor was selected as nitrogen source and scaled up to 5 L stirred-tank fermentor, and the final concentration of 5KGA reached 93.80 g/L, with its maximum volumetric productivity of 3.48 g/(L x h) and average volumetric productivity of 1.56 g/(L x h). The result obtained in this study showed that carbon and nitrogen sourses for large-scale production of 5KGA by Gluconobacter oxydans HGI-1 were glucose and corn steep liquor, respectively, and the available glucose almost completely (85.93%) into 5KGA.

Two Cases of Iatrogenic Calcinosis Cutis Following Extravasation of Calcium Gluconate in Neonates / 대한피부과학회지

No abstract available.

Bisphosphonate-induced Severe Hypocalcemia: A Case Report

Bisphosphonate generally seems to be safe, but hypocalcemia may occasionally develop in the course of bisphosphonate treatment. Hypocalcemia induced by bisphosphonate is usually mild and asymptomatic, but unrecognized or poorly treated hypocalcemia can lead to life-threatening state. A 78-year-old woman who had a history of hip arthroplasty and intravenous zoledronate treatment for femur neck fracture was presented to emergency department with altered mental status. It turned out that her symptom was due to severe hypocalcemia which was caused by intravenous zoledronate treatment. She also had renal dysfunction. She was treated by intravenous calcium gluconate and calcitriol administration. This case supports the need for evaluation of renal dysfunction, vitamin D deficiency and parathyroid gland dysfunction before bisphosphonate treatment and accurate monitoring of plasma calcium and creatinine levels. In addition, vitamin D and calcium supply during treatment with bisphosphonate is mandatory.

Proton-Pump Inhibitor-Induced Hypocalcemia and Hypomagnesemia

A 7-day-old female neonate who visited emergency depar tment due to generalized tonic seizure. Laboratory test results showed hypocalcemia (5.7 mg/dL), hypomagnesemia (0.55 mmol/L), low parathyroid hormone (7.5 pg/mL), and normal 25(OH) vitamin D3. Symptom and metabolic abnormalities were normalized with intravenous calcium gluconate and magnesium sulfate. Discharged with supplement of oral calcium, vitamin D, phenobarbital, and lansoprazol, she was re-admitted with hypocalcemia (4.8 mg/dL) with normal level of parathyroid hormone (12.3 pg/mL). Hypocalcemia was resolved with discontinuation of proton pump inhibitor. We report a case of recurrent hypocalcemia and hypomagnesemia due to proton-pump inhibitor.

Effect of zinc supplementation on insulin resistance and metabolic risk factors in obese Korean women

Zinc deficiency is known to be associated with insulin resistance in obese individuals. This study was performed to evaluate the effect of zinc supplementation on insulin resistance and metabolic risk factors in obese Korean women. Forty obese women (body mass index (BMI) > or = 25 kg/m2) aged 19-28 years were recruited for this study. Twenty women of the study group took 30 mg/day of supplemental zinc as zinc gluconate for 8 weeks and 20 women of control group took placebo. Usual dietary zinc intake was estimated from 3-day diet records. Insulin resistances were measured using Homeostasis model assessment (HOMA) indices, and insulin sensitivities Matsuda indices, which were calculated using oral glucose tolerance test data. Metabolic risk factors, such as waist circumference, blood pressure, fasting glucose, triglyceride, high density lipoprotein (HDL) cholesterol, and adipocyte hormones such as leptin, and adiponectin were also measured. At the beginning of study, dietary zinc averaged 7.31 mg/day and serum zinc averaged 12.98 micromol/L in the study group. Zinc supplementation increased serum zinc by 15% and urinary zinc by 56% (P < 0.05). HOMA values tended to decrease and insulin sensitivity increased slightly in the study group, but not significantly so. BMI, waist circumference, blood pressure, blood glucose, triglyceride, HDL cholesterol, and adipocyte hormones did not change in either the study or control group. These results suggest that zinc status may not affect insulin resistance and metabolic risk factors in obese Korean women. Further research is required on a larger cohort with a longer follow-up to determine the effects of zinc status on insulin resistance and metabolic variables.

Glycine- and GABA-mimetic Actions of Shilajit on the Substantia Gelatinosa Neurons of the Trigeminal Subnucleus Caudalis in Mice

Shilajit, a medicine herb commonly used in Ayurveda, has been reported to contain at least 85 minerals in ionic form that act on a variety of chemical, biological, and physical stressors. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) are involved in orofacial nociceptive processing. Shilajit has been reported to be an injury and muscular pain reliever but there have been few functional studies of the effect of Shilajit on the SG neurons of the Vc. Therefore, whole cell and gramicidin-perfotrated patch clamp studies were performed to examine the action mechanism of Shilajit on the SG neurons of Vc from mouse brainstem slices. In the whole cell patch clamp mode, Shilajit induced short-lived and repeatable inward currents under the condition of a high chloride pipette solution on all the SG neurons tested. The Shilajit-induced inward currents were concentration dependent and maintained in the presence of tetrodotoxin (TTX), a voltage gated Na+ channel blocker, CNQX, a non-NMDA glutamate receptor antagonist, and AP5, an NMDA receptor antagonist. The Shilajit-induced responses were partially suppressed by picrotoxin, a GABAA receptor antagonist, and totally blocked in the presence of strychnine, a glycine receptor antagonist, however not affected by mecamylamine hydrochloride (MCH), a nicotinic acetylcholine receptor antagonist. Under the potassium gluconate pipette solution at holding potential 0 mV, Shilajit induced repeatable outward current. These results show that Shilajit has inhibitory effects on the SG neurons of Vc through chloride ion channels by activation of the glycine receptor and GABAA receptor, indicating that Shilajit contains sedating ingredients for the central nervous system. These results also suggest that Shilajit may be a potential target for modulating orofacial pain processing.

Iron deficiency anemia in childhood

Iron deficiency anemia (IDA) frequently occurs in infants and adolescents. IDA is the result of an interplay between increased host requirements, limited external supply, and increased blood loss. In outpatient clinics, we often see children with iron deficiency anemia. Most cases in children are caused by incomplete nutrient supplements and growth spurts. However, we can occasionally see patients with poor response despite iron supplementation. Failure of iron therapy occurs when a child does not receive the prescribed medication, when iron is given in a form that is poorly absorbed, or when there is a continuing unrecognized blood loss such as intestinal or pulmonary loss, or loss with menstrual periods. In addition, the therapeutic failure of iron medication may indicate that the original diagnosis of nutritional iron deficiency was incorrect. In this situation, we have to evaluate other etiologies of anemia. Recently, many cases relating H.pylori infection to iron deficiency anemia have been described in the literature and H.pylori infection has emerged as a cause of refractory iron deficiency anemia that is unresponsive to oral iron therapy. Also, iron deficiency anemia induced by athletics in adolescent females has been reported several times. In this article, the author reviews various etiologies of childhood iron deficiency anemia. The most important consideration in treatment of iron deficiency anemia is disclosure of the underlying cause and its recovery. Dietary habits should also be corrected. To supplement iron, 6 mg/kg of oral iron supplements (elemental iron) is recommended in ferrous salt form. If oral administration is not feasible, intravenous supplementation is recommended using forms such as iron dextran, iron gluconate, or iron sucrose.

Impact of Plasma-Lyte pH 7.4 on acid-base status and hemodynamics in a model of controlled hemorrhagic shock

OBJECTIVE: Intravenous infusion of crystalloid solutions is a cornerstone of the treatment of hemorrhagic shock. However, crystalloid solutions can have variable metabolic acid-base effects, perpetuating or even aggravating shock-induced metabolic acidosis. The aim of this study was to compare, in a controlled volume-driven porcine model of hemorrhagic shock, the effects of three different crystalloid solutions on the hemodynamics and acid-base balance. METHODS: Controlled hemorrhagic shock (40 percent of the total blood volume was removed) was induced in 18 animals, which were then treated with normal saline (0.9 percent NaCl), Lactated Ringer's Solution or Plasma-Lyte pH 7.4, in a blinded fashion (n = 6 for each group). Using a predefined protocol, the animals received three times the volume of blood removed. RESULTS: The three different crystalloid infusions were equally capable of reversing the hemorrhage-induced low cardiac output and anuria. The Lactated Ringer's Solution and Plasma-Lyte pH 7.4 infusions resulted in an increased standard base excess and a decreased serum chloride level, whereas treatment with normal saline resulted in a decreased standard base excess and an increased serum chloride level. The Plasma-Lyte pH 7.4 infusions did not change the level of the unmeasured anions. CONCLUSION: Although the three tested crystalloid solutions were equally able to attenuate the hemodynamic and tissue perfusion disturbances, only the normal saline induced hyperchloremia and metabolic acidosis.

The subsidiary GntII system for gluconate metabolism in Escherichia coli: Alternative induction of the gntV gene

Two systems are involved in the transport and phosphorylation of gluconate in Escherichia coli. GntI, the main system, consists of high and low-affinity gluconate transporters and a thermoresistant gluconokinase for its phosphorylation. The corresponding genes, gntT, gntU and gntK at 76.5 min, are induced by gluconate. GntII, the subsidiary system, includes IdnT and GntV, which duplicate activities of transport and phosphorylation of gluconate, respectively. Gene gntV at 96.8 min is divergently transcribed from the idnDOTR operon involved in L-idonate metabolism. These genetic elements are induced by the substrate or 5-keto-D-gluconate. Because gntV is also induced in cells grown in gluconate, it was of interest to investigate its expression in this condition. E. coli gntK, idnOokan mutants were constructed to study this question. These idnO kan-cassete inserted mutants, unable to convert gluconate to 5-keto-D-gluconate, permitted examining gntV expression in the absence of this inducer and demonstrating that it is not required when the cells grow in gluconate. The results suggest that E. coli gntV gene is alternatively induced by 5-keto-D-gluconate or gluconate in cells cultivated either in idonate or gluconate. In this way, the control of gntV expression would seem to be involved in the efficient utilization of these substrates.

A Case of Successful Management of Inhalation Injury Caused by Hydrofluoric Acid Poisoning

Hydrofluoric acid (HFA) is an extremely corrosive fluid and should be handled very carefully. It penetrates tissue more quickly than typical acids, and has the systemic toxicity that can occur via dermal, ocular, inhalation, and oral routes. Furthermore, it interferes with nerve function, thus burns may not initially be painful but may become gradually painful. If the treatment is delayed, the extent and seriousness of injury and toxicity will be much more severe; HFA will be absorbed into the blood stream, react with serum calcium, and may cause arrhythmia or cardiac arrest. As the chemical industry grows, the frequency of HFA use is increasing, leading to increased incidences of HFA dermal burn. Yet, reports of HFA inhalation injury are rare. Presently, we treated one patient with HFA inhalation injury sustained during work at a cosmetic factory. The male presented an acutely ill appearance, shortness of breath, and cold sweating. At once, oxygen, IV antibiotics, and IV 20% calcium gluconate were administered, and the patient was closely monitored. The patient was admitted to the intensive care unit. Successful management led to discharge without any significant complications.

A Case of Successful Management of Inhalation Injury Caused by Hydrofluoric Acid Poisoning

Hydrofluoric acid (HFA) is an extremely corrosive fluid and should be handled very carefully. It penetrates tissue more quickly than typical acids, and has the systemic toxicity that can occur via dermal, ocular, inhalation, and oral routes. Furthermore, it interferes with nerve function, thus burns may not initially be painful but may become gradually painful. If the treatment is delayed, the extent and seriousness of injury and toxicity will be much more severe; HFA will be absorbed into the blood stream, react with serum calcium, and may cause arrhythmia or cardiac arrest. As the chemical industry grows, the frequency of HFA use is increasing, leading to increased incidences of HFA dermal burn. Yet, reports of HFA inhalation injury are rare. Presently, we treated one patient with HFA inhalation injury sustained during work at a cosmetic factory. The male presented an acutely ill appearance, shortness of breath, and cold sweating. At once, oxygen, IV antibiotics, and IV 20% calcium gluconate were administered, and the patient was closely monitored. The patient was admitted to the intensive care unit. Successful management led to discharge without any significant complications.

Hydrofluoric Acid Burns: A Case Report / 대한산업의학회지

BACKGROUND: Hydrofluoric acid_(HF) is widely used in many industrial and domestic settings such as etching glass, and polishing metals. HF is one of the most corrosive inorganic acids and can produce progressive and serious tissue necrosis with severe pain. Since HF chemical burns can be asymptomatic for the first few hours, it is crucial to understand its toxicity and the early use of antidote. CASE: A 37-year-old man presented with erythematous lesion and pain on his face, anterior neck, both forearms, both thighs, and left ankle after injury resulting from a chemical burn caused by HF. He showed normal vital signs and dyspnea, but complained of a sore throat. Liquid form of HF had splashed on his face and anterior neck first and run down his forearms and thighs while working at HF supply tanks. Some of the HF was splashed into his mouth. He immediately removed his clothes and showered with abundant water. A 4.5% calcium gluconate jel was applied to the involved area. He was given subcutaneous injection of 10% calcium gluconate solution. During 17 days of admission he didn't show any signs of systemic intoxication or deep tissue defects. CONCLUSIONS: Immediate cleansing of the affected area with running cold water is the first critical treatment for a chemical burn due to HF. Applying calcium gluconate gel within one hour was very effective for preventing further damage to the injured area as well as systemic injury. In order to reduce the risk of accident and perform first-aid treatment quickly, it is imperative to provide workers with safety education and establish safety facilities.

Analysis of the Adverse Effects Associated with Therapeutic Plasmapheresis / 대한수혈학회지

BACKGROUND: Although therapeutic plasmapheresis (TP) is a useful procedure in removing pathogenic antibodies and toxic substances from the patient, adverse reactions could arise from the use of replacement fluids and anticoagulants. Comprehensive analysis on those adverse effects had been rarely reported in Korea. METHODS: We retrospectively investigated the clinical records and the TP records from 3,962 TP sessions for 581 patients between January 1995 and October 2008 at Asan Medical Center, and we analyzed the adverse reactions related to TP. RESULTS: Adverse reactions were seen in 142 patients (24.4%) in 348 TP procedures (8.8%). Citrate toxicity was most frequently seen in 83 procedures (23.9%) followed by chills in 72 procedures (20.7%), allergic reactions in 69 procedures (19.8%) and hypotension in 60 procedures (17.2%). Citrate toxicity, chills and allergic reactions were seen more frequently in the TP procedures using FFP than in the TP procedures using albumin (P=0.001). The prevalence of citrate toxicity was significantly lower in the cases where calcium gluconate was administered (P<0.001), while it was significantly higher in the patients whose hematocrit was below 28.5% (P<0.001). In terms of severity, the mild, moderate and severe adverse reactions were 36.8%, 56.3% and 6.9%, respectively. CONCLUSION: TP is a relatively safe method of treatment, but it is important to predict and prevent adverse reactions and to respond appropriately to these adverse reactions.