Simultaneous determination of water-soluble whitening ingredients and adenosine in different cosmetic formulations by high-performance liquid chromatography coupled with photodiode array detection.

OBJECTIVE: The Korean Cosmetic Act regulates the use of functional cosmetics) by the law. Four functional cosmetic groups, whitening, anti-wrinkle, UV protection and combination of whitening and anti-wrinkle, were categorized according to the Korean Cosmetic Act and Functional Cosmetics Codex. In this study, high-performance liquid chromatography (HPLC) coupled with photodiode array detection (DAD) was employed for the simultaneous detection of arbutin (and its decomposition product, hydroquinone), niacinamide, ascorbyl glucoside, ethyl ascorbyl ether and adenosine in functional cosmetic products such as creams, emulsions and lotions. METHODS: Separation by HPLC-DAD was conducted using a C18 column with a gradient elution of 5 mm KH2PO4 buffer (containing 0.1% phosphoric acid) and methanol (containing 0.1% phosphoric acid). The wavelengths for the detection of arbutin, hydroquinone, niacinamide, adenosine, ascorbyl glucoside and ethyl ascorbyl ether were 283, 289, 261, 257, 238 and 245 nm, respectively. RESULTS: This method exhibited good linearity (R(2) ≥ 0.999), precision (expressed as relative standard deviation (RSD) < 2%) and mean recoveries (89.42-104.89%). The results obtained by monitoring 100 market samples showed that the detected levels of the tested materials are within the acceptable authorized concentration. CONCLUSION: The method developed herein is simple and can be used for market survey and quality control of functional cosmetics.

Simultaneous determination of arbutin and its decomposed product hydroquinone in whitening creams using high-performance liquid chromatography with photodiode array detection: Effect of temperature and pH on decomposition.

OBJECTIVE: Arbutin is an effective agent for the treatment of melanin disorders. Arbutin may be converted to hydroquinone under conditions of high temperature, ultraviolet (UV) radiation and dilute acid. The aim of the current study was to develop an analytical method to determine the levels of arbutin and hydroquinone in whitening cosmetic products using high-performance liquid chromatography with photodiode array detection (HPLC-DAD). In addition, we investigated the effects of high temperature and pH on the decomposition of arbutin. METHODS: Samples extracted using two-step sonications were separated on a C18 column using a gradient mobile phase consisting of water and methanol. A 60-mm (40 µL) DAD cell was used to enhance the sensitivity of hydroquinone determination. Thermal decomposition of arbutin was evaluated at temperatures ranging from 60 to 120°C for 1-36 h. RESULTS: The method showed good linearity (R(2) ≥ 0.9997), precision (relative standard deviation, RSD < 5%) and acceptable extraction recovery (90-102.6%). The limits of quantitation for arbutin and hydroquinone were 0.0085 and 0.0119 µg mL(-1) , respectively. One sample of 21 cosmetic products tested contained arbutin at a concentration 1.61 g 100 g(-1) cream and 0.12 g 100 g(-1) cream of hydroquinone. Arbutin (327.18 ppm) decomposed after 6 h at 120°C and produced 10.73 ppm of hydroquinone. CONCLUSION: The developed method is simple to detect both arbutin and hydroquinone simultaneously in cosmetic products, at an adequate level of sensitivity. Notably, temperature and pH did not influence the decomposition of arbutin to hydroquinone in a 2% arbutin cream.

The Chlamydomonas cell wall: characterization of the wall framework.

The cell wall of the biflagellate alga Chlamydomonas reinhardtii is a multilayered, extracellular matrix composed of carbohydrates and 20-25 polypeptides. To learn more about the forces responsible for the integrity of this cellulose-deficient cell wall, we have begun studies to identify and characterize the framework of the wall and to determine the effects of the cell wall-degrading enzyme, lysin, on framework structure and protein composition. In these studies we used walls released into the medium by mating gametes. When isolated shed walls are degraded by exogenously added lysin, no changes are detected in the charge or molecular weight of the 20-25 wall proteins and glycoproteins when analyzed on one- and two-dimensional polyacrylamide gels, which suggests that degradation of these shed walls is due either to cleavage of peptide bonds very near the ends of polypeptides or that degradation occurs via a mechanism other than proteolysis. Incubation of walls with Sarkosyl-urea solutions removes most of the proteins and yields thin structures that appear to be the frameworks of the walls. Analysis by polyacrylamide gel electrophoresis shows that the frameworks are highly enriched in a polypeptide of Mr 100,000. Treatment of frameworks with lysin leads to their degradation, which indicates that this part of the wall is a substrate for the enzyme. Although lysin converts the Mr 100,000 polypeptide from an insoluble to a soluble form, there is no detectable change in Mr of the framework protein. Solubilization in the absence of lysin requires treatment with SDS and dithiothreitol at 100 degrees C. These results suggest that the Chlamydomonas cell wall is composed of two separate domains: one containing approximately 20 proteins held together by noncovalent interactions and a second domain, containing only a few proteins, which constitutes the framework of the wall. The result that shed walls can be solubilized by boiling in SDS-dithiothreitol indicates that disulfide linkages are critical for wall integrity. Using an alternative method for isolating walls from mechanically disrupted gametes, we have also shown that a wall-shaped portion of these unshed walls is insoluble under the same conditions in which shed walls are soluble. One interpretation of these results is that wall release during mating and the wall degradation that follows may involve distinct biochemical events.

Pharmacokinetics and milk distribution characteristics of orbifloxacin following intravenous and intramuscular injection in lactating ewes.

The purpose of the current investigation is to elucidate the pharmacokinetic profiles of orbifloxacin (OBFX) in lactating ewes (n = 6) following intravenous (i.v.) and intramuscular (i.m.) administrations of 2.5 mg/kg W. In a crossover study, frequent blood, milk, and urine samples were drawn for up to 48 h after the end of administration, and were then assayed to determine their respective drug concentrations through microbiological assay using Klebsiella pneumoniae as the test micro-organism. Plasma pharmacokinetic parameters were derived from plasma concentration-time data using a compartmental and noncompartmental analysis, and validated a relatively rapid elimination from the blood compartment, with a slope of the terminal phase of 0.21 +/- 0.02 and 0.19 +/- 0.06 per hour and a half-life of 3.16 +/- 0.43 and 3.84 +/- 0.59 h, for i.v. and i.m. dosing, respectively. OBFX was widely distributed with a volume of distribution V((d(ss))) of 1.31 +/- 0.12 L/kg, as suggested by the low percentage of protein binding (22.5%). The systemic body clearance (Cl(B)) was 0.32 +/- 0.12 L/h x kg. Following i.m. administration, the maximum plasma concentration (C(max)) of 1.53 +/- 0.34 microg/mL was reached at t(max) 1.25 +/- 0.21 h. The drug was completely absorbed after i.m. administration, with a bioavailability of 114.63 +/- 11.39%. The kinetic milk AUC(milk)/AUC(plasma) ratio indicated a wide penetration of orbifloxacin from the bloodstream to the mammary gland. OBFX urine concentrations were higher than the concurrent plasma concentrations, and were detected up to 30 h postinjection by both routes. Taken together, these findings indicate that systemic administration of orbifloxacin could be efficacious against susceptible mammary and urinary pathogens in lactating ewes.

Co-prescribing of proton pump inhibitors among chronic users of NSAIDs in the UK.

OBJECTIVES: Co-prescribing of proton pump inhibitors (PPIs) with non-selective NSAIDs (nsNSAIDs) is recommended in patients at risk of gastrointestinal (GI) events. This study estimated usage of PPI co-therapy among chronic nsNSAID users and determined factors associated with concurrent nsNSAID-PPI use. METHODS: The retrospective study was based on the Intercontinental Marketing Services (IMS) Health UK MediPlus database and included subjects > or = 40 yrs of age who received their first oral nsNSAID prescription between July and December 2002 and who had > or = 60 days of nsNSAID supply during the following year. Days with nsNSAID-PPI overlap were calculated and logistic regression was used to identify factors associated with nsNSAID-PPI overlap. A generalized linear model was used to assess the degree of association of GI risk factors with the nsNSAID-PPI overlap ratio among PPI users. RESULTS: Of 16,344 patients included, 1586 received at least one PPI prescription. Among PPI users, PPIs were available on approximately 50% of the days with nsNSAID therapy. After multivariate adjustment, age > or = 65 yrs, history of any hospitalization and co-prescriptions for anti-coagulants or oral corticosteroids increased the odds of any nsNSAID-PPI overlap by 21-68%. Prior gastroprotective agent (GPA) use increased the odds of any PPI use during follow-up 16-fold and nsNSAID-PPI overlap 19-fold. Among PPI users, patients with prior use of any GPA had a 2.46 times higher nsNSAID-PPI overlap ratio. CONCLUSIONS: PPI utilization correlates poorly with nsNSAID use in the UK. GI safety of nsNSAID-PPI co-therapy observed in controlled trials may therefore not be achieved in clinical practice.

Surgical management of spinal cord haemangioblastoma.

BACKGROUND: The surgical management of spinal cord haemangioblastomas is distinct from that of other benign spinal cord tumours and optimal surgical strategy is still being determined because of the rarity of the condition. The aim of this study is to investigate factors that affect the outcome of surgical management. PATIENTS AND METHODS: We retrospectively analysed 24 operations for symptomatic spinal cord haemangioblastomas in 20 patients. Clinical features and surgical results were investigated by medical record review, telephone interviews, angiographic images, and magnetic resonance images (MRI). The mean follow-up period was 5.6 years (range 6 months to 13.6 years). RESULTS: Patients with cystic components showed pre-operative motor weakness and sensory change more commonly than those without cystic components. Post-operative function scale had a positive correlation with pre-operative function (R(2) = 0.727; p < 0.001) and no correlation with the extent of the surgery. All subtotally removed tumours recurred, whereas totally removed tumours recurred in only 3 patients. CONCLUSION: The cystic component of spinal cord haemangioblastomas is responsible for symptom generation and is helpful for dissecting tumours. Post-operative functional status is determined by pre-operative functional status. Total removal is feasible by using the correct surgical technique and is recommended to prevent recurrence.

Characterization of the pharmacokinetic disposition of levofloxacin in stallions after intravenous and intramuscular administration.

The target of the present study was to investigate the plasma disposition kinetics of levofloxacin in stallions (n = 6) following a single intravenous (i.v.) bolus or intramuscular (i.m.) injection at a dose rate of 4 mg/kg bwt, using a two-phase crossover design with 15 days as an interval period. Plasma samples were collected at appropriate times during a 48-h administration interval, and were analyzed using a microbiological assay method. The plasma levofloxacin disposition was best fitted to a two-compartment open model after i.v. dosing. The half-lives of distribution and elimination were 0.21 +/- 0.13 and 2.58 +/- 0.51 h, respectively. The volume of distribution at steady-state was 0.81 +/- 0.26 L/kg, the total body clearance (Cl(tot)) was 0.21 +/- 0.18 L/h/kg, and the areas under the concentration-time curves (AUCs) were 18.79 +/- 4.57 microg.h/mL. Following i.m. administration, the mean t(1/2el) and AUC values were 2.94 +/- 0.78 h and 17.21 +/- 4.36 microg.h/mL. The bioavailability was high (91.76% +/- 12.68%), with a peak plasma mean concentration (C(max)) of 2.85 +/- 0.89 microg/mL attained at 1.56 +/- 0.71 h (T(max)). The in vitro protein binding percentage was 27.84%. Calculation of efficacy predictors showed that levofloxacin might have a good therapeutic profile against Gram-negative and Gram-positive bacteria, with an MIC

Ultra-high mass multimer analysis of protein-1a capping domains by a silicon nanomembrane detector.

Conventional time of flight ion detectors are based on secondary electron multipliers encountering a significant loss in detection efficiency, sensitivity and resolution with protein mass above 50kDa. In this work we employ a silicon nanomembrane detector in a Matrix-Assisted Laser Desorption/Ionization coupled to time of flight (MALDI-TOF) mass spectrometer. The operating principle relies on phonon-assisted field emission with excellent performance in the high mass range from 0.001-2MDa. In addition to the analysis of standard proteins the nanomembrane detector (NMD) has the potential for the detection and structural investigation of complex macromolecular assemblies through non-covalent interactions. In order to investigate this hypothesis, the N-terminal capping/methyltransferase domain (CAP) of the Brome Mosaic Virus (BMV) 1a replication protein by MALDI-TOF-NMD is analyzed. The signals detected at the high m/z-ratios of 912.6/982.7 (×103) and 1333.3 (×103) could be modified species of CAP-tricta/tetractamer and the octadecamer. For the first time, the NMD is applied to detect biologically complex macromolecular protein assemblies. Hence, this technology overcomes the limitations of conventional TOF-detectors and increases the analytical range of MALDI-TOF. This technology will be a future alternative for the structural analysis of intact virus capsids that will complement other MS-based techniques such as native mass spectrometry.

Post-marketing surveillance study of the efficacy and safety of vardenafil among patients with erectile dysfunction in primary care.

To evaluate the safety and efficacy of vardenafil in primary care, we undertook a post-marketing surveillance study in 384 men with erectile dysfunction (ED), enrolled by 22 family physicians in Korea, from July 2004 to August 2005. Of the 384 patients enrolled, 343 (89.3%) returned for efficacy assessment and safety evaluation. Among the latter, 279 patients (81.3%) reported that their erectile function improved, 292 (92.1%) showed enhanced IIEF (International Index of Erectile Function)-5 scores and 265 (77.9%) responded that they were 'very satisfied' or 'satisfied' with vardenafil treatment. The most frequent reason for patient satisfaction with vardenafil was erectile potency (62.4%), followed by safety (42.4%), rapid onset (35.3%), adequate duration of efficacy (28.5%) and easy administration (25.9%). A total of 23 adverse events were observed in 18 patients, with the most frequent being hot flushes (3.2%), followed by headache (1.2%), nasal congestion (0.6%), color vision disturbance (0.3%), dizziness (0.3%), dry mouth (0.3%), dyspepsia (0.3%), nausea (0.3%) and diarrhea (0.3%). Only one patient discontinued vardenafil as a direct result of an adverse event. These results suggest that vardenafil prescribed by primary care physicians improved erectile function and was well tolerated by patients with ED.

Cervical arthroplasty in a patient with Klippel-Feil syndrome.

This is the first published report of a patient with Klippel-Feil syndrome treated with cervical arthroplasty. A 36-year-old man presented with posterior neck pain and myelopathic symptoms. A radiograph demonstrated congenital fusion of the vertebral bodies at C2-3, C4-5 and C5-6. On MRI, the spinal cord was compressed by a protruding cervical disc and bony spurs at C6-7. After anterior discectomy and decompression of the spinal cord at the C6-7 level, the disc was replaced with the Bryan cervical disc system (Medtronic Sofamor Danek, Memphis, TN, USA) to restore normal motion. The absence of adjacent segment degeneration and the preservation of cervical motion were noted 2 years after surgery. Arthroplasty may be performed in selected patients with Klippel-Feil syndrome in order to restore motion and to prevent degeneration of the adjacent segment by reducing hypermobility.

Outcome of surgery for a symptomatic herniated thoracic disc in relation to preoperative characteristics of the disc.

BACKGROUND: This report presents general information on herniated thoracic discs, their clinical manifestations as well as surgical treatment, and examines the differences in the surgical outcome based on disc characteristics. METHODS: This study includes 33 thoracic discectomies in 29 patients with a ventrally situated herniated thoracic disc reaching to the thoracic cord. Using preoperative computed tomography scanning and magnetic resonance imaging, the direction of the disc was classified as either central or lateral, and disc consistency classified as either soft or hard. Clinical outcome was assessed according to the Japanese Orthopedic Association (JOA) Score for thoracic myelopathy. The score was obtained by analysing motor, sensory and bladder function. Recovery rate was assessed, comparing preoperative and postoperative status based on disc characteristics. The correlations between outcome, symptom duration and recovery rate were also investigated. FINDINGS: Clinical outcome according to the JOA Score showed significant postoperative improvement, increasing from 7.0 +/- 3.1 points to 8.2 +/- 2.7 points postoperatively (p < 0.01). The mean recovery rate was 12.4 +/- 56.9%, and 16 patients (55.2%) showed improvement. In the soft disc group, there was improvement in all categories, but the hard disc group showed no improvement. The central disc group showed improvement in sensory function, but the lateral disc group showed little improvement. Regression analysis revealed a statistically significant correlation between the preoperative and postoperative score, symptom duration and recovery rate. CONCLUSIONS: Clinical outcome after surgery of a herniated thoracic disc proved successful, especially when the disc was considered to have a soft consistency. In order to decide the optimal surgical strategy and prospective surgical outcome, disc characteristics, including consistency and direction of prolapse should be considered preoperatively.

Bone temperature estimation during orthopaedic round bur milling operations.

Heat generation during orthopaedic bone cutting operations may cause thermal bone damage. During the bone cutting, the maximum temperature occurs at the point of contact between the bone and the cutting tool. However, this temperature is difficult to measure. Many researchers have attempted to measure this temperature using a thermocouple; however, limitations of the thermocouple makes it difficult to determine the maximum temperature at the point of contact. In order to solve this problem, in this study, two infrared thermometers are used to measure the fresh-milled surface temperature, and the maximum temperature was extrapolated by a moving plane heat source solution. The estimated maximum temperature increment varied from 49 to 115 degrees C under various cutting conditions. These results showed that the thermal damage may reach up to 1.9 mm in depth during round bur milling. A larger feed rate and a smaller cutting depth decreased the maximum temperature.

The 5'-untranslated region of GM-CSF mRNA suppresses translational repression mediated by the 3' adenosine-uridine-rich element and the poly(A) tail.

Granulocyte-macrophage colony stimulating factor (GM-CSF) mRNA levels are controlled post-transcriptionally by the 3'-untranslated region (UTR) adenosine-uridine-rich element (ARE). In untransformed, resting cells, the ARE targets GM-CSF mRNA for rapid degradation, thereby significantly suppressing protein expression. We used a rabbit reticulocyte lysate (RRL) cell-free system to examine translational regulation of GM-CSF expression. We uncoupled decay rates from rates of translation by programming the RRL with an excess of mRNAs. Capped, full-length, polyadenyl-ated human GM-CSF mRNA (full-length 5'-UTR AUUUA+A90) and an ARE-modified version (full-length 5'-UTR AUGUA+A90) produced identical amounts of protein. When the 5'-UTR was replaced with an irrelevant synthetic leader sequence (syn 5'-UTR), translation of syn 5'-UTR AUUUA+A90 mRNA was suppressed by >20-fold. Mutation of the ARE or removal of the poly(A) tail relieved this inhibition. Thus, in the absence of a native 5'-UTR, the ARE and poly(A) tail act in concert to block GM-CSF mRNA translation. Substitutions of different regions of the native 5'-UTR revealed that the entire sequence was essential in maintaining the highest rates of translation. However, shorter 10-12 nt contiguous 5'-UTR regions supported 50-60% of maximum translation. The 5'-UTR is highly conserved, suggesting similar regulation in multiple species and in these studies was the dominant element regulating GM-CSF mRNA translation, overriding the inhibitory effects of the ARE and the poly(A) tail.

Phenotype and genotype of advanced premalignant head and neck lesions after chemopreventive therapy.

BACKGROUND: The goal of chemoprevention is to reduce the risk of cancer development by reversing or blocking the tumorigenic process through the use of pharmacologic or natural agents. To determine the potential role of genetic alterations in assessing cancer risk and in evaluating the efficacy of chemopreventive agents, we studied 22 patients with advanced premalignant lesions of the head and neck who were part of a prospective cancer prevention trial that is investigating a regimen of 13-cis-retinoic acid, interferon alfa, and alpha-tocopherol administered for 12 months or until disease progression. METHODS: We used polymerase chain reaction analysis of microsatellite DNA sequences in cells from precancerous lesions to determine the frequencies of genetic alterations--namely, loss of heterozygosity (LOH) and microsatellite instability--at chromosomal loci that are commonly deleted in head and neck cancer. RESULTS: Prior to treatment, 17 (81%) of 21, eight (44%) of 18, and eight (42%) of 19 patients who were informative (i.e., heterozygous) at chromosomes 9p21, 3p14, and 17p13, respectively, exhibited LOH in at least one of their lesion biopsy specimens. Among nine patients who exhibited LOH at chromosome 9p21 in pretreatment biopsy specimens and who had completed at least 5 months of therapy, the genetic loss persisted in eight--including three of the four patients who exhibited complete histologic responses (i.e., no evidence of dysplasia in their biopsy specimens). IMPLICATION: Our data suggest that clinical and histologic assessments of the response to chemopreventive agents may be insufficient to determine their efficacy and that critical genetic alterations could be used as independent biomarkers to augment the ability to evaluate the efficacy of such agents.

Clinical benefit of nomogram for predicting positive resection margins in breast conserving surgery.

PURPOSE: Previously, we reported a nomogram for the prediction of positive resection margin (RM) after breast conserving surgery (BCS). This study was conducted to evaluate the clinical usefulness of the nomogram. METHODS: Prospective patients who underwent operations using the nomogram between July 2012 and August 2013 (nomogram group; N = 260) were compared with past control patients who underwent operations between July 2010 and October 2011 and underwent frozen section biopsy (FSB) without use of the nomogram (N = 266). In the nomogram group, an intraoperative assessment of RM using FSB was only performed when the nomogram score was higher than predefined cut-off (>80). In addition, we conducted retrospective analysis of additional 181 patients who received BCS in another institute (Kyoto University Hospital). These patients did not undergo FSBs for RMs. RESULTS: Of 260 patients, 161 (61.9%) presented low nomogram scores and avoided FSB. The surgical decision to use the nomogram did not significantly increase reoperation rate due to positive RM compared with the control FSB group (4.6% vs. 3.8%, p = 0.47). The surgery time was significantly reduced by 18.1% (mean 14.7 min) in nomogram group (p < 0.001). Of 99 nomogram high-score patients, 14 presented with positive RM on FSB and 11 of them avoided reoperation. In the Kyoto cohort, the reoperation rate was significantly lower in low-score patients than in high-score patients (2.7% vs. 11.4%, p < 0.001). CONCLUSIONS: We showed that our nomogram is useful to reduce FSBs without increasing reoperation rate for surgeons who perform routine FSBs. For most surgeons, it can give useful information about the possibility of tumor-positive RMs.

Substance p plays a critical role in photic resetting of the circadian pacemaker in the rat hypothalamus.

Glutamate is considered to be the primary neurotransmitter in the retinohypothalamic tract (RHT), which delivers photic information from the retina to the suprachiasmatic nucleus (SCN), the locus of the mammalian circadian pacemaker. However, substance P (SP) also has been suggested to play a role in retinohypothalamic transmission. In this study, we sought evidence that SP from the RHT contributes to photic resetting of the circadian pacemaker and further explored the possible interaction of SP with glutamate in this process. In rat hypothalamic slices cut parasagittally, electrical stimulation of the optic nerve in early and late subjective night produced a phase delay (2.4 +/- 0.5 hr; mean +/- SEM) and advance (2.6 +/- 0.3 hr) of the circadian rhythm of SCN neuronal firing activity, respectively. The SP antagonist L-703,606 (10 microm) applied to the slices during the nerve stimulation completely blocked the phase shifts. Likewise, a cocktail of NMDA (2-amino-5-phosphonopentanoic acid, 50 microm) and non-NMDA (6,7-dinitroquinoxaline-2,3-dione, 10 microm) antagonists completely blocked the shifts. Exogenous application of SP (1 microm) or glutamate (100 microm) to the slices in early subjective night produced a phase delay ( approximately 3 hr) of the circadian firing activity rhythm of SCN neurons. Coapplication of the NMDA and non-NMDA antagonist cocktail (as well as L-703,606) resulted in a complete blockade of the SP-induced phase delay, whereas L-703,606 (10 microm) had no effect on the glutamate-induced delay. These results suggest that SP, as well as glutamate, has a critical role in photic resetting. Furthermore, the results suggest that the two agonists act in series, SP working upstream of glutamate.

The secondary structure of myelin P2 protein derived by secondary structure prediction methods, circular dichroism, and 400-MHz 1H-NMR spectroscopy: implications for tertiary structure.

The various methods used to study the secondary and tertiary structure of myelin P2 protein, and one of its peptides (CN1), in aqueous solution, indicate that the native protein contains a significant fraction of alpha-helix, suggesting that the current prediction of an all-beta tertiary structure requires revision.

Dynamic equilibrium unfolding pathway of human tumor necrosis factor-alpha induced by guanidine hydrochloride.

The dynamic equilibrium unfolding pathway of human tumor necrosis factor-alpha (TNF-alpha) during denaturation at different guanidine hydrochloride (GdnHCl) concentrations (0-4.2 M) was investigated by steady-state fluorescence spectroscopy, potassium iodide (KI) fluorescence quenching, far-UV circular dichroism (CD), picosecond time-resolved fluorescence lifetime, and anisotropy decay measurements. We utilized the intrinsic fluorescence of Trp-28 and Trp-114 to characterize the conformational changes involved in the equilibrium unfolding pathway. The detailed unfolding pathway under equilibrium conditions was discussed with respect to motional dynamics and partially folded structures. At 0-0.9 M [GdnHCl], the rotational correlation times of 22-25 ns were obtained from fluorescence anisotropy decay measurements and assigned to those of trimeric states by hydrodynamic calculation. In this range, the solvent accessibility of Trp residues increased with increasing [GdnHCl], suggesting the slight expansion of the trimeric structure. At 1.2-2.1 M [GdnHCl], the enhanced solvent accessibility and the rotational degree of freedom of Trp residues were observed, implying the loosening of the internal structure. In this [GdnHCl] region, TNF-alpha was thought to be in soluble aggregates having distinct conformational characteristics from a native (N) or fully unfolded state (U). At 4.2 M [GdnHCl], TNF-alpha unfolded to a U-state. From these results, the equilibrium unfolding pathway of TNF-alpha, trimeric and all beta-sheet protein, could not be viewed from the simple two state model (N-->U).

Conjugation of low-molecular-weight heparin and deoxycholic acid for the development of a new oral anticoagulant agent.

BACKGROUND: Heparin administration is usually limited to intravenous or subcutaneous injection. Oral delivery of heparin is an alternative to this and has been in great demand for treating patients who are at a high risk of deep vein thrombosis or pulmonary embolism. In this study, new heparin derivatives were synthesized to enhance the oral absorption of heparin in the gastrointestinal tract. Methods and Results- By using heparin of 3000 Da [LMWH(3 kDa)], heparin of 6000 Da [LMWH(6 kDa)], and unfractionated heparin (UFH), we synthesized 3 kinds of conjugates of heparin and deoxycholic acid (DOCA): LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA. After oral administration of 100 mg/kg of heparin-DOCA, the maximum activated partial thromboplastin times of the LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA were 31.0+/-6.0, 87.8+/-11.1, and 51.0+/-8.7 seconds, respectively. The peak plasma concentrations of LMWH(3 kDa)-DOCA, LMWH(6 kDa)-DOCA, and UFH-DOCA were 0.06+/-0.02, 0.76+/-0.15, and 0.41+/-0.13 IU/mL, respectively. The bioavailability of LMWH(6 kDa)-DOCA at the 20-mg/kg dosage was calculated to be 7.8%. CONCLUSIONS: LMWH(6 kDa)-DOCA was found to have a high anticoagulant effect when administered orally and could be used as a new oral anticoagulant agent. Furthermore, the present work proposed a new method for oral delivery of macromolecules and polysaccharide drugs.

Catalysis of the oxidative folding of bovine pancreatic ribonuclease A by protein disulfide isomerase.

The major oxidative folding pathways of bovine pancreatic ribonuclease A at pH 8.0 and 25 degrees C involve a pre-equilibrium steady state among ensembles of intermediates with zero, one, two, three and four disulfide bonds. The rate-determining steps are the reshuffling of the unstructured three-disulfide ensemble to two native-like three-disulfide species, des-[65-72] and des-[40-95], that convert to the native structure during oxidative formation of the fourth disulfide bond. Under the same regeneration conditions, with oxidized and reduced DTT, used previously for kinetic oxidative-folding studies of this protein, the addition of 4 microM protein disulfide isomerase (PDI) was found to lead to catalysis of each disulfide-formation step, including the rate-limiting rearrangement steps in which the native-like intermediates des-[65-72] and des-[40-95] are formed. The changes in the distribution of intermediates were also determined in the presence and absence of PDI at three different temperatures (with the DTT redox system) as well as at 25 degrees C (with the glutathione redox system). The results indicate that the acceleration of the formation of native protein by PDI, which we observed earlier, is due to PDI catalysis of each of the intermediate steps without changing the overall pathways or folding mechanism.