[Analysis of ROX Index, ROX-HR Index, and SpO2/FIO2 Ratio in Patients Who Received High-Flow Nasal Cannula Oxygen Therapy in Pediatric Intensive Care Unit]

PURPOSE

This study aimed to evaluate the use of the respiratory rate oxygenation (ROX) index, ROX-heart rate (ROX-HR) index, and saturation of percutaneous oxygen/fraction of inspired oxygen ratio (SF ratio) to predict weaning from high-flow nasal cannula (HFNC) in patients with respiratory distress in a pediatric intensive care unit.

METHODS

A total of 107 children admitted to the pediatric intensive care unit were enrolled in the study between January 1, 2017, and December 31, 2021. Data on clinical and personal information, ROX index, ROX-HR index, and SF ratio were collected from nursing records. The data were analyzed using an independent t-test, χ² test, Mann-Whitney U test, and area under the curve (AUC).

RESULTS

Seventy-five (70.1%) patients were successfully weaned from HFNC, while 32 (29.9%) failed. Considering specificity and sensitivity, the optimal cut off points for predicting treatment success and failure of HFNC oxygen therapy were 6.88 and 10.16 (ROX index), 5.23 and 8.61 (ROX-HR index), and 198.75 and 353.15 (SF ratio), respectively. The measurement of time showed that the most significant AUC was 1 hour before HFNC interruption.

CONCLUSION

The ROX index, ROX-HR index, and SF ratio appear to be promising tools for the early prediction of treatment success or failure in patients initiated on HFNC for acute hypoxemic respiratory failure. Nurses caring for critically ill pediatric patients should closely observe and periodically check their breathing patterns. It is important to continuously monitor three indexes to ensure that ventilation assistance therapy is started at the right time.

Experiences of Living Donors for Small Bowel Transplantation

INTRODUCTION

Along with developments in surgical and immunosuppression techniques, the success rate of small bowel transplantation has increased. In Korea, the incidence of small bowel transplantations has increased, and the longest surviving living donor recipient has now survived for over 12 years postsurgery. The purpose of this study was to assess the experiences of living donors for small bowel transplantation before, during, and after the transplantation.

METHODS

In one hospital, we conducted interviews, based on open-ended questions, with three small bowel donors. We asked them about experiences during small bowel donation. The living donor's statements were analyzed using interpretive phenomenological analysis.

RESULTS

Donors decided to donate because they felt "sorry for the suffering of a family member" and they had "faith in the medical staff." In the early phase after donation, living donors experienced physical changes in their body, including pain, fatigue, altered bowel habits, and abdominal discomfort. Despite temporary limitations in daily and social activities, support from family members allowed the donors to fully recover and return to normal physical, social, and psychological status. The donors mentioned they experienced love and support from their family, as well as satisfaction and pride from donation, during the entire process.

CONCLUSION

We hope that the physical, psychological, and social experience of living donors during small bowel transplantation deduced in this study will serve as a foundation for the establishment of an intervention method to provide education before donation and help recovery after donation.

Development and Effects of a Transition Nursing Program for Patients and Family Caregivers at a Neurological ICU in Korea

The purpose of this study was to develop a transition nursing program for patients and family caregivers in neurological intensive care units (ICUs) and to evaluate the effects of the program. A literature review, focus group interviews, analysis of medical records, confirmation of validity, and clinical applicability were used to develop the program, which was tested using a pre- and post-test quasi-experimental design. Participants were recruited in 2011. The experimental group (46 patients and their family caregivers) received the developed program before transferring from the neurological ICU to a ward, whereas the control group (48 patients and their family caregivers) received routine care. The results showed that patients and family caregivers in the experimental group had significantly higher transition readiness and satisfaction with transition nursing and lower transition anxiety and transition stress, and family caregivers in the experimental group had a significantly lower burden of caregiving.

[Effects of aromatherapy on changes in the autonomic nervous system, aortic pulse wave velocity and aortic augmentation index in patients with essential hypertension]

PURPOSE

To investigate the effectiveness of aromatherapy on blood pressure, heart rate variability, aortic pulse wave velocity and the aortic augmentation index of essential hypertensive patients.

METHODS

Using a coin toss, 22 participants were assigned to the experimental group and 20 to the control. The experimental group was given a blend of oils of lemon (Citrus limonum), lavender (Lavandula angustifolia), and ylang ylang (Cananga odorata) which were prepared in the ratio of 2:2:1, respectively. The control group was given an artificial lemon fragrance of Limonene (35 cc) and Citral (15 cc) mixture. The experiment, inhalation, was conducted for 3 weeks (2 min per inhalation, 2 times per day) to both groups.

RESULTS

There was a noticeable difference in systolic blood pressure between the groups (p=.001), however the difference in diastolic blood pressure between the two groups was not significant. There was a notable difference in sympathetic nerve system activity of heart rate variability (p=.047). However, the differences in aortic pulse wave velocity or the aortic augmentation index were not significant.

CONCLUSION

Aromatherapy is effective in lowering systolic blood pressure and sympathetic nerve system activity.

Effects of a bereavement intervention program on depression and life satisfaction in middle aged widows in Korea

PURPOSE

This study was designed to examine the effects of a bereavement intervention program on levels of depression and life satisfaction in middle aged widows in Korea.

METHODS

A quasi-experimental design with non-equivalent control-group pretest-posttest was used. The subjects (control group, n = 10; intervention group, n = 17) were bereaved less than 6 months in G City and J Province, Korea. The bereavement intervention program consisted of Dan-jeon breathing, self-help group activities and a health examination. The experimental group attended 10 sessions of a bereavement intervention program. The control group had a health examination without the intervention program. For both groups, the level of depression and life satisfaction levels were measured before and after the experiment.

RESULTS

The decrement of depression level in the experimental group was significantly greater than in the control group (p<.001). The increment in life satisfaction in the experimental group was significantly greater than in the control group (p<.001).

CONCLUSION

The results suggested that the bereavement intervention program was effective in decreasing level of depression and in increasing the life satisfaction of widows. Accordingly, a bereavement intervention program can be applied as an intervention to help widows.

Simulation and sensitivity analysis of phosphorylation of EGFR signal transduction pathway in PC12 cell model

The epidermal growth factor receptor (EGFR) signalling pathway is a complex signalling process with a wide network of interactions. The activation of the mitogen-activated protein kinases (MAPKs) cascade by this activated EGFR has been well studied. MAPKs form a highly integrated network, which is essential for certain specialised cell functions. This paper presents a kinetic model for the MAPK pathway downstream of the EGFR using a biochemical simulator. The model includes 30 signalling events and 29 signalling molecules. The time course data were examined for the activation of each signalling component. The simulation provides a large volume of data, by monitoring the kinetics of the signalling components, which were compared experimentally using the PC12 cell line. The kinetic model corresponded well with the experimental results observed in the EGFR induced activation of proteins. An examination of the kinetic analysis of the multiple signalling events provides a quantitative framework for representing the EGFR signalling network.

WITHDRAWN: Effectiveness of bedding control instruction for patients with respiratory allergies: A randomized controlled trial

Readers are asked to note that the International Journal of Nursing Studies has requested that this paper be withdrawn due to concerns relating to possible duplicate publication. The publishers, Elsevier, are keen to ensure that papers published in this journal maintain high levels of clinical accuracy and academic excellence in all papers accepted for publication.References: Gotsche (ref); Moon (response); Norman & Griffiths (editorial).

Effect of asthma management education program on stress and compliance of patients with allergic asthma to house dust mite

PURPOSE

This study was designed to examine the effect of asthma management education program applied to allergic asthma patients receiving immunotherapy due to house dust mite on their stress and compliance with health care regimens.

METHODS

A quasi experimental design with non-equivalent control group and non-synchronized design was used. The subjects of this study were 61 patients who were receiving immunotherapy at intervals of a week after their symptoms were diagnosed as house dust mite allergic asthma at the pulmonary department of a university hospital in Seoul. They were divided into an experimental group of 29 patients who received asthma management education and a control group of 32 patients. The asthma management education program was composed of group education (once) and reinforcement education (three times) with environmental therapy and immunotherapy to house dust mite.

RESULTS

Stress significantly decreased in the experimental group compared to that in the control group. Compliance with health care regimens significantly increased in the experimental group compared to that in the control group.

CONCLUSIONS

The results suggested that the asthma management education program is effective for the management of stress and the improvement of compliance in patients with allergic asthma to house dust mite.

An individualized teaching program for atherosclerotic risk factor reduction in patients with myocardial infarction

This study was conducted to evaluate the effect of a teaching program on patients with myocardial infarction. Forty-five patients were randomly selected 22 were assigned to a teaching group and 23 to a control group. An individualized teaching program was delivered to the teaching group during the hospitalization period. It covered aspects such as: the characteristics of heart disease, the anatomy and physiology of the heart, risk factors of atherosclerosis, medication and diet and exercise therapy. When these subjects were discharged to their homes, they received regular supportive care via telephone or mail for 12 weeks. Atherosclerotic risk factors, including, smoking, exercise, blood lipid profile and BMI were measured before and after the teaching program. Post-testing revealed that the numbers of those who exercised and the number of non-smokers were significantly higher in the teaching group than in the control group. Increased HDL cholesterol (High-Density Lipoprotein cholesterol) was significantly greater in the teaching group than in the control group. The above findings suggest that this individualized teaching program might be helpful at reducing the risk factors of atherosclerosis in myocardial infarction patients.

Uncertainty analysis of absolute concentration measurement with continuous-wave cavity ringdown spectroscopy

To evaluate the uncertainty of concentration measurement using cavity ringdown spectroscopy, we analytically derived expressions for uncertainty for parameters, such as temperature, laser frequency, and ringdown time deviation, from the model equation. The uncertainties that are due to systematic errors in a practical cavity ringdown system were assessed through an experimental study of the PQ(35) transition in an A band of molecular oxygen. We found that, except for the line strength that is regarded as a reference value independent of the measurement, the laser frequency jitter is the largest uncertainty source in the system. Some practical requirements for minimizing the uncertainty in concentration measurements are discussed. We also demonstrated determination of the line strength of the PQ(35) transition line of oxygen to be 8.63(3) x 10(-27) cm(-1) with a relative uncertainty of less than 0.4%.

Competitive immunoassay for recombinant hirudin using capillary electrophoresis with laser-induced fluorescence detection

A competitive immunoassay based on capillary electrophoresis (CE) with laser-induced fluorescence (LIF) has been developed for the determination of recombinant hirudin (r-hirudin) in biological mixtures. Hirudin, a thrombin inhibitor, is a polypeptide of 65 amino acids. To check purity levels and perform pharmacokinetic studies of (r-hirudin), specific and reproducible analysis methods are demanded. The work involved the development of separation conditions allowing for routine analysis of plasma samples. In this study, r-hirudin was labeled with fluorescein isothiocyanate (FITC), and FITC-labeled r-hirudin was purified using high-performance liquid chromatography. The purified product was then mixed with the sample followed with the addition of anti-hirudin antibody. Free, antibody-bound, and tagged r-hirudin could be separated within 5 min by CE analysis using uncoated fused-silica capillary with high reproducibility. The developed method can be used to determine r-hirudin with good precision and a detection limit lower than 20 nM. This result demonstrates the feasibility of the CE-LIF immunoassay method for the determination of r-hirudin in plasma samples.

Capillary electrophoresis of high-molecular chitosan: the natural carbohydrate biopolymer

Due to its high resolving power and diverse application range, capillary electrophoresis (CE) has been successfully applied to the analysis of carbohydrates. In this paper, a method for the determination of high-molecular chitosan (Mr 200,000) using CE is presented. We studied the optimal condition of buffer pH and type, and column type for determination of chitosan. Optimal CE performance was found when employing 100 mM triethylamine (TEA)-phosphate buffer, pH 2.0 and untreated fused-silica capillary (50 microm x 27 cm) for the chitosan analysis. Under optimum conditions, excellent linear responses were obtained in the concentration range of 1.25-20 microM, with a linear correlation coefficient of 0.9983. The standard deviations of the migration time and peak area were found to be 2.5 and 6.4%, respectively. This method could be readily applied to chitosan determination in real biological samples and commercial products.

Influence of buffer composition and sample pretreatment on efficiency separation for monitoring neuropeptides in plasma using capillary electrophoresis

More efficient and faster separation conditions for qualitative as well as quantitative analysis of neuropeptides in human plasma using capillary zone electrophoresis (CZE) have been developed. The analysis method for neuropeptides has been improved specifically to study thyroid hormone related neuropetides for the regulation of thyroid disease. In this study, we investigated the pretreatment methods, composition of the running buffer and rinsing procedures between runs in order to obtain more sensitive and faster separation of trace neuropeptides in plasma by CZE. The tested neuropeptides were somatostatin (SOMA), vasopressin (VP), neurotensin (NT), and thyrotropin-releasing hormone (TRH). Plasma samples were pretreated by deproteinization and solid-phase extraction method. The fraction of neuropeptides was reconstituted in 40% acetonitrile followed by ultrafiltration, and then analyzed by CZE. Resolution and sensitivity was improved using the separation buffer composition with 100 mM Tris-phosphate buffer (pH 2.0) while the sensitivity was further improved via a stacking method using the sample buffer of 40% acetonitrile. These sample pretreatment methods and buffer condition permit quantitative analysis on tested neuropeptides at the 20 ng/mL level. The rinsing procedures between runs using 90% ethanol dramatically shortened the rinsing time to 30 min.

Measurement of testosterone and pregnenolone in nails using gas chromatography-mass spectrometry

An efficient method for the determination of testosterone and pregnenolone in human nails using gas chromatography-mass spectrometry (GC-MS) with d3-testosterone as an internal standard is described. The method involves alkaline digestion and liquid-liquid extraction, with subsequent conversion to mixed pentafluoropenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive analysis in the selected-ion monitoring (SIM) mode. The limit of detection (LOD) and limit of quantification (LOQ) were lowered to 0.1 and 0.2 pg/g, respectively, when 100 mg of nail-clippings were used. The mean recoveries of testosterone and pregnenolone were 89.8 and 86.7%, respectively, while good overall precision (% C.V.; 4.5-9.5) and accuracy (% bias; 3.9-8.4) were demonstrated. Linearity as a correlation coefficient was 0.9913 (testosterone) and 0.9965 (pregnenolone). When applied to fingernail and toenail samples from seven healthy men and nine healthy women, testosterone and pregnenolone were positively detected in the concentration range of 0.24-5.80 ng/g. The levels of two steroids studied in the nails were found to be higher in the male subjects than in the female subjects, and except for the toenails of the females, the levels of testosterone were higher than those of pregnenolone.

Biochemical roles of testosterone and epitestosterone to 5 alpha-reductase as indicators of male-pattern baldness

In establishing a theory to predict male-pattern baldness, we investigated the correlation of testosterone, epitestosterone, and dihydrotestosterone with 5alpha-reductase in hair using gas chromatography-mass spectrometry. One hundred milligram hair samples were obtained from a group of balding subjects and their sons, as well as from a corresponding aged-matched, nonbalding group. The ratio of testosterone to epitestosterone was significantly greater (mean 46.41, p < 0.001; mean 35.83, p < 0.001, respectively) in the hair of balding fathers (n = 19, age 28-50 y) and their sons (n = 16, age 8-16 y) than in the hair of the nonbalding control subjects (mean 9.17 and 10.47, respectively). These findings demonstrate that analysis of terminal hair may not only provide a basis for predicting baldness when the subject is still young, but also for preventing and treating male-pattern baldness by controlling the steroid hormone balance.

Phlegmonous enteritis in a patient with congestive heart failure and colon cancer

Phlegmonous enteritis is a rare infective inflammatory disease of the intestine, predominantly involving the submucosal layer. It is difficult to diagnose and often fatal. Its association with alcoholism and various liver diseases, although rarely reported, is well documented. We report a case of phlegmonous enteritis in a male patient with congestive heart failure and colon cancer, and describe the ultrasonographic and CT findings.

Huge biliary cystadenoma mimicking cholecystic lymphangioma in subhepatic space

Biliary cystadenoma is a rare cystic neoplasm and constitutes only 5% of all intrahepatic cysts of biliary origin. We report a case of a 44-year-old woman with huge biliary cystadenoma in the subhepatic space, mimicking a cholecystic lymphangioma. Findings of various imaging modalities including reconstructed CT image are presented and correlated with surgical and pathologic findings.

Measurement of ultralow supermirror birefringence by use of the polarimetric differential cavity ringdown technique

We demonstrate a novel technique for measuring ultralow linear birefringence of supermirrors (high-reflectivity dielectric mirror coatings). The polarimetric cavity ringdown technique is used in conjunction with the differential detection scheme with circular polarization to enhance the measurement sensitivity. The technique could, in principle, provide the convenience and reliability of linear detection signals and a reasonable tolerance to experimental imperfections. Phase retardation and orientation of each cavity mirror can be determined separately without the influence of the other mirror. The minimum detectable phase retardation achieved experimentally with this technique is ~6 x 10(-8) rad.

Isolation and characterization of a tetrachloroethylene dechlorinating bacterium, Clostridium bifermentans DPH-1

A tetrachloroethylene (PCE)-degrading gram-positive, endospore forming, anaerobic bacterium, strain DPH-1, was isolated from a contaminated site. The organism was identified as Clostridium bifermentans by 16S rRNA gene sequence analysis and based on its physiological characteristics. Strain DPH-1 could dechlorinate high concentrations of PCE (0.9 mM), via trichloroethylene (TCE) to cis-1,2-dichloroethylene (cDCE) at a rate of 0.43 micromol/h.mg protein, as well as a number of other halogenated aliphatic compounds.

Characterization of epidermal growth factor receptor function in lysophosphatidic acid signaling in PC12 cells

Lysophosphatidic acid (LPA) is a lipid metabolite that induces the activation of mitogen-activated protein kinase (MAPK) through binding to the G protein-coupled receptor in a number of cell lines and cultures. Recent studies have revealed that LPA is able to rapidly induce the phosphorylation of MAPK through an epidermal growth factor (EGF) receptor-dependent pathway. We investigated the role of the EGF receptor in the signaling pathway initiated by LPA stimulation in nerve growth factor (NGF)-responsive PC12 cells well known to transiently retract their own neurites upon LPA stimulation. LPA-stimulated MAPK signaling was suppressed by the selective EGF receptor inhibitor and in the dominant negative mutant EGF receptor cell line. As in the EGF signaling pathway, the complex of EGF receptor with adapter proteins Shc and Sos was formed in response to LPA stimulation, suggesting there is an intracellular mechanism for transactivation. A neurite retraction assay was also performed to examine the role of the EGF receptor in PC12 cell differentiation, which related to the involvement of LPA-induced neurite retraction. These results suggest that the receptor tyrosine kinase can be activated in a ligand-independent manner through intracellular crosstalk between the signaling pathways.

Two interaction modes of the gp41-derived peptides with gp41 and their correlation with antimembrane fusion activity

Peptides derived from gp41 effectively block the gp41-mediated cell fusion or HIV infection. A 36-mer (naDP178), 51-mer (C51) and 27-mer peptide (C27) from the membrane proximal region of gp41 have been examined their interaction modes with the coiled-coil motif of gp41 presented in thioredoxin (Trx-N) or the bacterially expressed ectodomain of gp41 (Ec-gp41ec). All of these peptides effectively inhibited the gp41-mediated membrane fusion, however, they showed distinct interaction modes with Ec-gp41ec or Trx-N. C51 peptide bound tightly to Trx-N, and it increased the solubility of Ec-gp41ec. naDP178 showed very weak binding affinity to Trx-N, however, it effectively solubilized Ec-gp41ec. In contrast, C27 peptide showed significant binding to Trx-N; however, it did not affect the solubility of Ec-gp41ec. These interaction modes of C-peptides were assumed to be related to their different inhibitory mechanism against gp41-mediated cell fusion.

Cyclodextrin-mediated micellar electrokinetic chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the enantiomer separation of racemorphan in human urine

Micellar electrokinetic chromatography (MEKC) was successfully and conveniently applied to the chiral separation with the addition of cyclodextrins (CDs) as chiral selector to the running buffer. Chiral separation depended on the type of CD; in particular, beta-CD was effective for the chiral separation of racemorphan. We investigated the optimal conditions of type and concentration of CD as chiral selector for the routine enantiomeric separation of racemorphan with good reproducibility. The effects of other parameters such as buffer pH and detection wavelength were also investigated to obtain the optimum conditions for the enantiomeric separation of racemorphan. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for confirmation of racemorphan. The optimal conditions for enantiomeric separation of the racemorphan were as follows: 50 mM borate buffer at pH 9.4 with 50 mM SDS, 10 mM beta-CD and 20% 1-propanol, 57 cm x 50 microns fused-silica capillary column, and UV detection at 192 nm. Based on the developed method, racemorphan in human urine was also separated and determined using solid-phase extraction and MEKC.

Determination of enzymatic activity and properties of secretory phospholipase A2 by capillary electrophoresis

A capillary electrophoretic (CE) system coupled with a diode array UV detector was used for the assay of secretory phospholipase A2 (sPLA2) activity. This method is based on monitoring both the breakdown of substrates and the formation of products simultaneously using micellar electrokinetic chromatographic techniques. Under our developed separation conditions, we analyzed the substrates and products quantitatively, and investigated enzyme activity as a function of reaction time and presence of enzyme activator or inhibitor. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was also utilized to confirm the phosphatidylcholine, a substrate of sPLA2. In order to test the feasibility of the developed method for measurement of enzymatic activity, we compared it to the conventional radioactive assay method for sPLA2. On the basis of our results, the conventional method can be complemented, or even replaced, by this new CE method which possesses the advantages of short analysis time, use of non-radiolabeled and inexpensive substrates, simple measurement of enzymatic activity, and exact quantitation of substrate and product.

Proliferation not apoptosis as a prognostic indicator in retinoblastoma

The balance between proliferation and cell death is the major determinant of tumour growth. We analysed the proliferative and apoptotic indices (PI and AI, respectively) of 33 children with retinoblastoma. PI and AI were assessed by immunohistochemistry for Ki-67 antigen and TUNEL staining, respectively. The mean PI was 21.0+/-21.1%, and higher PI was associated with more advanced tumour stage (P<0.0001) and poor clinical outcome (P<0.05). Patients in whom amplified N-myc oncogene was found (n=6) determined by the multiplex polymerase chain reaction tended to have a higher PI (37.6+/-27.2%) than those without amplified N-myc (n=27; PI=17.3+/-18.1). A PI value of over 40% was clearly associated with an unfavourable prognosis. The AI, however, did not correlate with any of the other variables analysed. The findings suggest that proliferation, but not apoptosis, is of critical significance in retinoblastoma biology. PI, as determined by the Ki-67 antigen labelling index, seems to be a relevant histopathological parameter that can predict the clinical outcome of retinoblastoma.

Measurement of the linewidth of a continuous-wave laser with a cavity-length modulation technique

We introduce a Fabry-Perot cavity-length modulation technique for measuring the linewidth of a continuous wave (cw) laser. We calculate the peak intensity of a cw laser transmitted through a Fabry-Perot cavity as a function of mirror speed. By fitting the experimental data to the results of the calculation, we determine the linewidth of a frequency-stabilized cw laser. The linewidth of a cw ring dye laser measured in the 570-590-nm wavelength range is approximately 170 +/- 20 kHz. We also demonstrate the use of this technique to measure the reflectivity of a high-reflectance mirror.

Cavity ringdown spectroscopy with a continuous-wave laser: calculation of coupling efficiency and a new spectrometer design

For the efficient operation of a cavity ringdown spectroscopy (CRDS) system utilized with a continuous-wave (cw) laser, we numerically analyze the coupling efficiency of a cw laser to a ringdown cavity in terms of changes in the scanning rate, the laser linewidth, and the mirror reflectivity. We also demonstrate a new simple design for a CRDS system that can produce a CRDS signal with only a piezoelectric transducer (PZT), without the acousto-optic modulator that is usually adopted to switch off the cw laser beam that enters the cavity. Furthermore, we investigate the feasibility of the cw CRDS technique with a fast-scanning PZT by recording a CRDS spectrum of acetylene overtones. The detection sensitivity that corresponds to the noise-equivalent absorption is found to be approximately 3 x 10(-9)/cm.

Suppression of amplified spontaneous emission from a four-pass dye laser amplifier

We demonstrate a new design for a four-pass dye laser amplifier that can be used to reduce amplified spontaneous emission (ASE) in the amplifier output beam. Compared with the results obtained from normal operation of the four-pass dye laser amplifier without a frequency-selective device, by using a diffraction grating in the amplifier we can reduce the ASE ratio by a factor in excess of 10 and increase output energy by ~4%. The obtained ASE ratio of the four-pass amplifier system is <1.5%.

Application of capillary electrophoresis to determination of enzyme activity and other properties of phosphatidylinositol-specific phospholipase C

This paper describes a method for monitoring enzymatic activity using micellar electrokinetic chromatography (MEKC). MEKC is used to analyze the activity of phosphatidylinositol-specific phospholipase C (PI-PLC) with convenience and precision. PI specific PLC enzyme converts phosphatidylinositol (PI) to diacylglycerol (DAG) and inositol 1,2-cyclic phosphate (IP). The assay system developed is based on monitoring both the breakdown of substrate and the formation of products simultaneously. To obtain the best separation for the substrate PI and product DAG, we investigated changes in concentration of electrolyte buffer and SDS as well as in pH of the electrolyte buffer. Since the structures of the substrate and products are different, the reaction could be monitored easily by MEKC mostly based on hydrophobicity. Under the separation conditions developed, we investigated the enzymatic activity of PI-PLC depending on the concentrations of phosphatidylinositol, various divalent cations and the reaction temperature. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to confirm the molecular masses of the substrate PI and products DAG and IP. The results of this study show that capillary electrophoresis can be widely applied to analyze and characterize many other enzymes since capillary electrophoresis has several advantages as follows, simplicity, speed, no need for radiolabelled substrate, small sample volumes and sufficient accuracy.

Separation of gangliosides using cyclodextrin in capillary zone electrophoresis

Gangliosides are glycosphingolipids containing sialic acid. These glycolipids have been suggested to play important roles in biological processes such as cell growth, differentiation and malignant transformation. Based on these proposed biological functions, gangliosides can be used as diagnostic tools and therapeutics for various human diseases. In this study, capillary zone electrophoresis (CZE) was used to determine the major gangliosides GM1, GD1a, GD1b and GT1b in mammalian brains, in addition to GM3 and Lac. Enhancement of selectivity and efficiency of separation was obtained by using 50 mM borate-phosphate buffer containing 16.5 mM alpha-cyclodextrin (alpha-CD). Under this condition, several forms of gangliosides were successfully separated from extracts of deer antler, apricot seed and rat brain. The results demonstrate that the CD-modified CZE is a useful method for detecting glycolipids from various biological matrices.

The effect of thermal biofeedback and progressive muscle relaxation training in reducing blood pressure of patients with essential hypertension

In order to assess the effectiveness of the thermal biofeedback training combined with the progressive muscle relaxation therapy in the treatment of patients with essential hypertension, blood pressure decline was measured on the treatment group who had the combined thermal biofeedback and progressive muscle relaxation training (N = 11), and on the control group who had only the progressive muscle relaxation training (N = 8). Baseline blood pressure was measured four times for two weeks on both groups. For the treatment group, blood pressure was measured twice before and after each of eight sessions of thermal biofeedback training for four weeks. For the control group, blood pressure was measured every two visits to a clinic for progressive muscle relaxation self-training twice before and after the self-training. A significant decline of the systolic blood pressure by 20.6 mmHg and of the diastolic blood pressure by 14.4 mmhg was observed in the treatment group. There was a tendency for both blood pressures to increase in the control group.

Neural regulation of phenylethanolamine N-methyltransferase in vivo: transcriptional and translational changes

The hypothesis that neural regulation of rat adrenal medullary phenylethanolamine N-methyltransferase (PNMT, EC 2.1.1.28) occurs through transcriptional control is examined by following temporal changes in PNMT mRNA expression using paradigms of acute and chronic reserpine treatment. Concommitant changes in PNMT activity and protein were also measured to determine if reserpine induced changes depend solely on gene activation. Further, changes in adrenal corticosterone were measured to examine whether mRNA and enzyme responses might be mediated via reserpine induced changes in ACTH, and hence, corticosterone. Steady-state levels of PNMT mRNA peaked at approximately 8-fold normal by 6 h after a single reserpine injection (10 mg/kg i.p.), and then declined to control values. With continued treatment, a second, slower rise occurred after three alternate day injections (approximately 3-fold basal levels). Enzyme activity and protein rose simultaneously but were attenuated in magnitude and time course by comparison to message. With both acute and chronic treatment, activity increased 2.0-fold, peaking at 12 h after a single dose of reserpine and again after four doses of the drug. Protein, as measured by immunotitration, was elevated 1.2-and 1.4-fold, respectively. Adrenal corticosterone rose approximately 8-fold at 6 h, declined slightly at 12 h, rose again, and remained elevated thereafter. Comparison of the time courses for the various indices demonstrated that the early parallel bursts in PNMT mRNA and corticosterone are consistent with an increase in transcriptional activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Probing the function of conserved RNA structures in the 30S subunit of Escherichia coli ribosomes

Ribosomes play an active role in protein biosynthesis. Ribosomal RNA conformation in ribosomal subunits, intramolecular interactions between different rRNA sequences within the confinement of the particles, and intermolecular interactions are presumed necessary to support efficient and accurate protein synthesis. Here we report an analysis of the disposition of 16S rRNA conserved zones centered about positions 525, 1400, and 1500 in 30S subunits. Complementary oligodeoxyribonucleotides in conjunction with nuclease S1 digestion were used to do this. All of the sequences examined in 30S subunits are accessible to DNA probes of 9 to 12 nucleotide residues in length. However, the kinetic characteristics of the respective DNA interactions with 30S particles vary significantly. In addition to the investigation of normal 30S particles, a four base deletion within the 1400 region of 16S rRNA was analyzed. The deletion was made by using synthetic DNAs to target the deletion site for RNase H digestion. The direct in vitro procedure for manipulating rRNA conserves nucleotide modifications. The alteration causes a significant change in the disposition of 16S rRNA in 30S subunits, suggesting a reduction in the freedom of movement of the altered zone in the particle. In a factor-dependent in vitro protein synthesis system primed with MS2 mRNA and altered 30S subunits, there was a 50% decrease in phage coat protein synthesis. The reduction could be due to a decrease in the rate of translation or premature termination of translation. We present evidence here, based on isotopic studies, which supports the latter possibility.

Genotoxicity of beryllium, gallium and antimony in short-term assays

The genotoxicity of beryllium, gallium and antimony compounds was studied with the rec, Salmonella mutagenicity and SCE assays. In the rec assay, all the salts of the metals, BeCl2, Be(NO3)2, GaCl3, Ga(NO3)3, SbCl3, SbCl5, and an oxide, Sb2O3, had DNA-damaging activity. None of the compounds was mutagenic to Salmonella. In the SCE assays using V79 cells, 2 antimony(III) compounds, SbCl3 and Sb2O3, and 2 beryllium compounds, BeCl2 and Be(NO3)2, induced SCEs significantly. Sb2O3, slightly soluble in water, was positive in both the rec assay and the SCE assay at very low doses.

Primary structure of bovine adrenal phenylethanolamine N-methyltransferase

Bovine adrenal medullary phenylethanolamine N-methyltransferase (E.C. 2.1.1.28) was sequenced to determine if primary structure or post-translational processing accounts for the charged isozymes. A blocked NH2-terminus precluded amino terminal sequencing. Therefore, cyanogen bromide and tryptic peptide fragments were isolated and subjected to gas phase/gas-liquid phase sequencing. Primary structure was identified for 45% of the protein. At least two polypeptide chains exist with alternative amino acids representing conservative changes or single-base changes in amino acid codons by comparison to the cDNA sequence for the enzyme.