"Loose folding" and "delayed oxidation" procedures successfully applied for refolding of fully reduced hen egg white lysozyme

Several factors and/or procedures were examined quantitatively to improve the refolding yields of hen egg white lysozyme from its fully denatured and reduced state. Firstly, we found that refolding treatments were better conducted at lower lysozyme concentrations. The refolding yield decreased from 70% to less than 5% by increasing the lysozyme concentration from 1 to 36 microM in the refolding solution, probably due to aggregation. Secondly, in order to reduce the aggregation and improve the efficiency of refolding, we applied the "loose folding" procedure which required the incubation in the presence of about 2 M urea. The refolding of the lysozyme, studied at 17.4 microM, increased the yield to 80% yield in the presence of 2 M urea compared with a 30% yield in the absence of urea. Furthermore, we obtained a dramatic refolding yield of more than 95% in an experiment conducted at a concentration of 1.1 microM lysozyme, in the presence of 2 M urea. Finally, we examined the "delayed oxidation" procedure which meant that conformational folding preceded formation of disulfide bonds. The application of this procedure resulted in increases of 5-10% in the refolding yield. These procedures are expected to be useful in improving the refolding yield of precipitated proteins, for example, formed during recombinant DNA protein syntheses.

Elevated serum leptin concentrations in women with components of multiple risk factor clustering syndrome

This cross sectional study was undertaken to determine whether serum leptin levels were associated with multiple risk factor (MRF) clustering syndrome. We examined the relationship between serum leptin concentrations and blood pressure (BP), serum lipids levels, calculated insulin resistance (HOMA-ratio) and adiposity among 581 Japanese adult women. The serum leptin was increased in female subjects with systolic (> or =160 mmHg) and diastolic > or =90 mmHg) hypertension compared with the normotensive females (mean+/-SE; 9.3+/-0.5 vs 7.7+/-0.3; 10.2+/-0.6 vs 7.1+/-0.3 ng/ml, both p<0.001). Serum leptin was elevated in those with hyper-cholesterolemia (C; > or =220 mg/dl) and triglyceridemia (TG; > or =150 mg/dl) compared with the normolipidemia (9.4+/-0.4 vs 7.8+/-0.3; 11.7+/-0.6 vs 7.5+/-0.2 ng/ml, both p <0.001). Serum leptin was also elevated in those with adiposity (BMI > or =26.4 kg/m2) and insulin resistance (HOMA-ratio > or =2.5) compared with the normal females (14.8+/-0.7 vs 5.2+/-0.2; 11.3+/-1.1 vs 7.1+/-0.4ng/ml, both p<0.001). Even after adjusting for BMI or percent body fat mass (BFM), leptin levels remained to be elevated significantly in all these diseases. There was a positive correlation between serum leptin and systolic, diastolic BP, TC, TG, BMI, BFM, IRI and HOMA-ratio (r=0.12, p=0.005; r=0.24, p<0.0001; r=0.19, p<0.0001; r=0.35, p<0.0001; r=0.72, p<0.0001; r=0.73, p<0.0001; r=0.47, p< 0.0001; r=0.44, p<0.0001), and a negative correlation with HDL-C levels (r= -0.20, p< 0.0001). These correlations were also observed in leptin levels after adjusting for the BMI or BFM. Multiple regression analysis showed that BFM, HOMA-ratio and TG were significant determinants of leptin concentration before (t=12.6, p<0.0001; t=3.33, p=0.001; t=3.22, p=0.001) and after adjusting for BMI or BFM. These results suggest that because serum leptin levels were elevated in components of MRF clustering syndrome, leptin may have a pathophysiological role in MRF clustering syndrome.

Support network utilization by breastfeeding mothers

The Utilization of Support Network Questionnaire (USNQ) was developed to determine how mothers utilize their network for successful breastfeeding. Sixty breastfeeding mothers completed the USNQ. Lactation consultants were the most utilized resources for providing expert information and answering questions. Husbands, friends, or family were important resources for closest personal facets of breastfeeding, including encouraging confidence. At two weeks postpartum, breastfeeding mothers had larger total support scores than non-breastfeeding mothers. USNQ reliably discriminated between professional and personal support for breastfeeding.

Japanese individuals do not harbor the T594M mutation but do have the P592S mutation in the C-terminus of the beta-subunit of the epithelial sodium channel: the Ohasama study

OBJECTIVE

To assess the implications of polymorphisms of the amiloride-sensitive epithelial sodium channel in essential hypertension in the Japanese population by determining the incidence of the T594M mutation in the , subunit of the epithelial sodium channel, and by screening the C-terminus of the epithelial sodium channel.

METHODS

Single-strand confirmational polymorphism (SSCP) analysis using two sets of primers which cover the last two-thirds of the last exon coding the B epithelial sodium channel and modification of a specific enzyme restriction site (NlaIII) for the T594M mutation were performed on 803 Japanese subjects. They were randomly selected from the study participants representative of a general population of Ohasama, Japan, who measured their home blood pressure. Polymerase chain reaction (PCR) products presenting a shift in SSCP gel, as well as controls, were directly sequenced by autoanalyser to identify the mutation.

RESULTS

SSCP analysis identified altered migration in five subjects. Four SSCP variants found by sequencing were heterogeneous for the P592S (CCT to TCT) mutation conserving the PY motif, although it was not significantly associated with either home or casual blood pressure values. The resting polymorphism was at codon Thr 594, leading to no change in the amino acid sequence (ACG to ACA). None of the PCR products were modified by NlaIII, indicating the absence of the T594M mutation.

CONCLUSIONS

The epithelial sodium channel variants at the C-terminus are not involved in the common form of essential hypertension in Japanese.

Stable tRNA precursors in HeLa cells

Two tRNA precursors were isolated from 32P-labeled or unlabeled HeLa cells by two dimensional polyacrylamide gel electrophoresis, and were sequenced. These were the precursors of tRNAMet and tRNALeu, and both contained four extra nucleotides including 5'-triphosphates at their 5'-end and nine extra nucleotides including oligo U at their 3'-end. These RNAs are the first naturally occurring tRNA precursors from higher eukaryotes whose sequences have been determined. In these molecules, several modified nucleosides such as m2G, t6A and ac4C in mature tRNAs were undermodified. Two additional hydrogen bonds were formed in the clover leaf structures of these tRNA precursors. These extra hydrogen bonds may be responsible for the stabilities of these tRNA precursors.

Modeling the pressure inactivation dynamics of Escherichia coli

Escherichia coli, as a model microorganism, was treated in phosphate-buffered saline under high hydrostatic pressure between 100 and 300 MPa, and the inactivation dynamics was investigated from the viewpoint of predictive microbiology. Inactivation data were curve fitted by typical predictive models: logistic, Gompertz and Weibull functions. Weibull function described the inactivation curve the best. Two parameters of Weibull function were calculated for each holding pressure and their dependence on holding pressure was obtained by interpolation. With the interpolated parameters, inactivation curves were simulated and compared with the experimental data sets.

Effects of diethylstilbestrol on the cytogenesis of prolactin cells in the pars distalis of the pituitary gland of the mouse

This study was carried out to examine the developmental stage when prolactin cells differentiate in mice and to examine the effects of diethylstilbestrol on the development of prolactin cells in the fetal and neonatal pituitary glands. A small number of immunoreactive prolactin cells appeared first on embryonic day 15 in control (injected with oil) pituitary glands, whereas they did not increase in number until postnatal day 2. In diethylstilbestrol-treated mice (5 mg/kg body weight, 24 h before killing), a small number of immunoreactive prolactin cells were detectable as early as embryonic day 14, but not on day 13. They increased in number on embryonic days 15 and 16, and decreased markedly on days 17 and 18, followed by a rapid increase after birth. This transient reduction in the response to diethylstilbestrol was partially restored by treatment with metyrapone, a specific inhibitor of corticosteroid production. These results suggest that in the mouse: (1) differentiation of prolactin cells occurs between embryonic days 13 and 14, (2) prolactin gene expression is suppressed in the nascent prolactin cells presumably due to the presence of high levels of estrogen-binding protein, alpha-fetoprotein, and (3) prolactin gene expression is also suppressed by elevation of circulating glucocorticoids during the perinatal period. The present results suggest that, in the mouse, at least a proportion of prolactin cells are not derived from growth hormone cells, because the diethylstilbestrol-induced prolactin cells appear earlier than growth hormone gene expression.

Achievement of renaturation of subtilisin BPN' by a novel procedure using organic salts and a digestible mutant of Streptomyces subtilisin inhibitor

The pro-sequences of proteases have been considered to be required for the refolding of denatured proteases. However, here we report achievement of almost complete restoration of enzymatic activity of subtilisin BPN' in the absence of its pro-sequence. The presence of 2 M potassium acetate in the folding medium enhanced the refolding efficiency of guanidine hydrochloride (GdnHCl)-denatured subtilisin BPN' by up to 28%, and other organic salts were also found to be useful, suggesting that general contribution of the bulky hydrophobic moieties of the salts to the formation of a favorable environment required for folding. This finding will provide new insights into the folding mechanisms not only of proteases but also of various other proteins. Almost complete restoration of enzymatic activity of denatured subtilisin in the organic salt solution was accomplished by further addition of mutated Streptomyces subtilisin inhibitor (SSI), which had been converted to a digestible temporary inhibitor by removal of the disulfide bridge near the reactive site.

Relationship of changes in serum concentrations of prolactin and testosterone during dopaminergic modulation in males

To evaluate the effect of PRL on the male pituitary-gonadal system, serum concentrations of PRL, testosterone, LH and FSH were determined in healthy young men daily before, during, and after 3-day oral administration of bromocriptine, metoclopramide or sulpiride. Bromocriptine (2.5 mg as a single dose) caused, concurrently with a marked suppression of serum PRL, a significant increase of serum testosterone and a transient decrease of serum LH. The changes of PRL and testosterone were negatively correlated. With metoclopramide (10 mg q.i.d.) serum PRL was increased and testosterone inversely decreased. There was no change in LH and FSH. Sulpiride (50 mg q.i.d.) evoked the elevation of serum PRL and LH, but no change in testosterone. A significant increase in serum concentration of testosterone was also observed in a patient with PRL-producing pituitary tumour and four out of seven patients with acromegaly during bromocriptine treatment. These results suggest an inhibitory effect of PRL on testosterone secretion at the gonadal level, or direct dopaminergic stimulatory control of testosterone secretion.

Participation of endodermal epithelial cells on the synthesis of plasma LDL and HDL in the chick yolk sac

We ultrastructually examined the chick yolk sac endodermal epithelium and evaluated our findings in combination with the biochemical analysis of serum and yolk lipoproteins. Twenty-five to 30 nm-sized particles were demonstrated to be a principal element of the extracellular yolk mass and these were determined to be yolk very low density lipoprotein (VLDL). The particles were shown to be taken up by the epithelial cells via coated pits and engulfed by plasma membrane invaginations together with yolk subdroplets, another element of the yolk mass. Through apical vacuoles, the two yolk elements were incorporated into yolk drops, which were identified to be one of the lysosomal structures by a cytochemical procedure using acid phosphatase (AcP)ase activity. During the last week of incubation, which is the final third of the incubation period, the digestion seemed to progress rapidly in the yolk drops, which came to resemble lipolysosomes; lipoprotein production became active as expressed by an enlarged Golgi apparatus. The newly produced lipoprotein particles were electron-lucent and irregular in size (50-120 nm). They were sequestered in secretory vacuoles and secreted from the vascular surface of the epithelial cells. Finally, the particles were thought to be taken into the vitelline circulation as plasma lipoproteins. The major component of lipoprotein in serum was determined to be low density lipoprotein (LDL) and high density lipoprotein (HDL), while cholesterol content was found to increase during incubation. We concluded that endodermal epithelial cells participate the synthesis of plasma LDL and HDL. For this synthesis the cells probably apply lipids and apo-protein generated from yolk VLDL degradation.

Risk factors and predictors of coronary arterial lesions in Japanese hypertensive patients

The morbidity rate of coronary artery disease has recently increased in Japan. This is attributable to changes from traditional to more westernized lifestyles. In this study, we therefore examined the risk factors and predictors of coronary arterial lesions in Japanese patients with essential hypertension. Coronary angiography was performed in 109 consecutive essential hypertension patients (57 men and 52 women; 66 +/- 8.0 years of age) with either angina pectoris or atypical chest pain, who were chosen from 485 consecutive hypertensive patients in a hypertension clinic in Sendai, Japan. Coronary arterial stenosis of greater than 50% was defined as significant and used as a dependent variable for the multiple regression analysis. Risk factors were defined as factors confirmed to have a causal relationship with coronary arterial lesions, whereas arteriosclerotic complications and hypertensive target organ damage were defined as predictors. Multiple logistic regression analysis was performed using these parameters as independent variables. Of 109 patients, 25 had a coronary arterial stenosis greater than 50%. A smoking habit (odds ratio (OR): 4.48; 95% confidence interval (CI): 1.13-17.82; p<0.05), hypercholesterolemia (OR: 5.34; 95% CI: 1.52-18.73; p<0.05), and 24-h diastolic blood pressure (OR: 2.33; 95% CI: 1.06-5.16; p<0.05) were significant risk factors, whereas carotid intima-media thickness (OR: 5.85; 95% CI: 1.48-23.2; p<0.05) was a significant predictor of coronary arterial lesion. When two of the major risk factors (a smoking habit, hypercholesterolemia, or impaired glucose tolerance including diabetes mellitus) were clustered in addition to the hypertension, the risk of coronary arterial lesions increased by 6.7 to 10.1 times. These findings indicate that the major risk factors established in Caucasians, i.e., a smoking habit, hypercholesterolemia and blood pressure level, are also risk factors for coronary arterial lesions in Japanese with essential hypertension. The presence of two or more risk factors increases the risk of coronary arterial lesions synergistically in the presence of hypertension.

Factors which affect the progression of osteoarthritis after rotational acetabular osteotomy

We have investigated the factors which affect the progression of osteoarthritis after rotational acetabular osteotomy (RAO). Between 1984 and 1998, we treated 60 dysplastic hips by RAO. The mean age at surgery was 31.6 years (13 to 51) and the mean period of follow-up was 4.6 years (2 to 9.5). The thickness of the articular cartilage on the weight-bearing area, pre- and postoperative acetabular cover, and the sphericity of the femoral head were used for radiological assessment. The osteoarthritis did not progress in 39 hips. Significant factors which affected the radiological grade included sphericity of the femoral head and the postoperative acetabular cover. The surgical approach and preoperative acetabular cover did not affect the progression of osteoarthritis. Patients were divided into two groups according to the surgical approach used, either conventional (23 hips) or modified (37 hips). Significant factors included the postoperative acetabular cover in the modified approach, and the sphericity of the femoral head in the conventional approach. It is critical that the postoperative cover is sufficient, especially when RAO is carried out using our modified technique.

Olopatadine hydrochloride suppresses the rebound phenomenon after discontinuation of treatment with a topical steroid in mice with chronic contact hypersensitivity

BACKGROUND

Olopatadine hydrochloride (olopatadine; Allelock) is one of the second-generation antihistamines that are treated for allergic disorders such as rhinitis, urticaria and eczema dermatitis. Olopatadine has recently been shown to have inhibitory effects on the chronic contact hypersensitivity induced by repeated application of oxazolone in mice. Although topical steroids have widely been prescribed for atopic dermatitis, a relapse often occurs within several days after discontinuation of their prolonged use.

OBJECTIVES

We investigated the possible efficacy of olopatadine against the relapse after discontinuation of prolonged use of topical prednisolone in the Balb/c mice with oxazolone-induced chronic contact hypersensitivity.

METHODS

Mice with the chronic contact hypersensitivity induced by repeated application of oxazolone were treated with olopatadine as a sequential therapeutic agent. The effects of olopatadine were quantified by measurements of ear-swelling, and levels of cytokines and histamine in the lesioned ear. Results Topical prednisolone (0.05 mg/ear/day) significantly inhibited the increases in ear swelling and production of IL-1beta, IL-4, IL-18, granulocyte-macrophage colony-stimulating factor (GM-CSF) and histamine. However, after discontinuation of the treatment with topical prednisolone, the inflammation relapsed and the IL-4 level exceeded the control one. The sequential treatment with olopatadine (10 mg/kg/day) after discontinuation of the treatment with topical prednisolone alone, or topical prednisolone with olopatadine, significantly inhibited the increases in ear swelling and levels of IL-1beta, IL-4, IL-18, GM-CSF, nerve growth factor and histamine.

CONCLUSIONS

These results indicate that olopatadine is an antihistamine agent having inhibitory activities against the rebound phenomenon following the discontinuation of topical steroid therapy. Olopatadine is thus expected to be a sequential therapeutic agent after discontinuation of the chronic treatment with a topical steroid.

Isoprenoid enzyme systems of silkworm. I. Partial purification of isopentenyl pyrophosphate isomerase, farnesyl pyrophosphate synthetase, and geranylgeranyl pyrophosphate synthetase

Isopentenyl pyrophosphate isomerase, farnesyl pyrophosphate synthetase, and geranylgeranyl pyrophosphate synthetase were detected in cell-free extracts of Bombyx mori and were partially purified by hydroxyapatite and Sephadex G-100 chromatography. Two forms of farnesyl pyrophosphate synthetase were chromatographically separated. They were designated as farnesyl pyrophosphate synthetases I and II in the order of their elution from hydroxyapatite. Both enzymes catalyzed the exclusive formation of (E,E)-farnesyl pyrophosphate from isopentenyl pyrophosphate and either dimethylallyl pyrophosphate or geranyl pyrophosphate. However, they were not interconvertible, unlike the enzyme from pig liver. These two enzymes resembled each other in pH optima and molecular weights but differed in susceptibility to metal ions. Farnesyl pyrophosphate synthetase II was stimulated by Triton X-100 while synthetase I was inhibited by the same reagent.

Serum leptin and lipids in patients with thyroid dysfunction

This work was undertaken to examine the relationship between thyroid hormone and serum leptin concentration. This study included 368 Japanese female subjects (27 were affected with pretreatment hyperthyroidism, 68 with hyperthyroidism during treatment, 19 with pretreatment hypothyroidism, 57 with hypothyroidism during treatment and 197 euthyroid control subjects) and 60 control male subjects. In the control group, serum leptin levels in males were lower than those recorded in females (mean +/- SD; 4.6 +/- 4.1 vs 9.5 +/- 6.4 ng/ml, p < 0.001). The leptin values correlated well with body mass index (BMI) and body fat mass (BFM) in both control male and female subjects (p < 0.001 for each). The serum leptin levels in pretreatment female patients with hyperthyroidism were significantly lower than those in the pretreatment patients with primary hypothyroidism and control female subjects (6.4 +/- 3.0 vs 9.7 +/- 6.3, 9.5 +/- 6.4 ng/ml; p < 0.05, 0.02, respectively), but after adjusting for BMI and BFM, the difference was mainly due to the significantly different BMI and BFM. Furthermore, serum leptin did not change significantly during the treatment in hyper and hypothyroidism. There was no correlation between serum leptin and thyroid hormones or lipids levels in female patients with thyroid disorders. Adiposity and gender were the major determinants of leptin concentration, but thyroid hormones did not appear to play any relevant role in leptin synthesis and secretion in human.

Dynamical identification of a threshold instability in Si-doped heterofullerenes

We rationalize the origins of a threshold instability and the mechanism of finite temperature fragmentation in highly Si-doped C(60-m)Si(m) heterofullerenes via a first-principles approach. Cage disruption is driven by enhanced fluctuations of the most internal Si atoms. These are located within fully segregated Si regions neighboring the C-populated part of the cage. The predominance of inner Si atoms over those involved in Si-C bonds marks the transition from thermally stable to unstable C(60-m)Si(m) systems at m = 20.

Certified Reference Material for Analytical Quality Assurance of Minor and Trace Elements in Food and Related Matrixes Based on a Typical Japanese Diet: Interlaboratory Study

A Certified Reference Material (CRM) was prepared at the National Institute for Environmental Studies (NIES), Japan, in collaboration with the National Institute of Radiological Sciences (NIRS), Japan, for the analytical quality assurance of minor and trace elements in food and related matrixes. The starting material for the CRM was all food served in 29 households in Japan over two 3-day periods in 1997–1998, and thus the CRM represented a typical Japanese diet. All foods (meals, snacks, and beverages) were homogenized, freeze-dried, pulverized, blended, dispensed into 1100 bottles, and sterilized. The within- and between-bottle homogeneity of the prepared CRM was satisfactory for most of the elements. The concentrations of 14 elements (Na, Mg, K, Ca, Mn, Cu, Zn, As, Se, Sr, Cd, Sn, Ba, and U) were certified based on a collaborative analysis involving NIES, NIRS, and 20 other laboratories. Reference values were given for the concentrations of 12 additional elements (P, Cl, Fe, Co, Ni, Br, Rb, Mo, I, Cs, Pb, and Th). The elements certified and those given reference values include minerals, essential trace elements, contaminant elements, and long-lived radionuclides. Thus, this CRM is of practical value in the quality assurance of element analysis of foods and diets in nutritional, environmental, and radiological research.

Magnetic resonance imaging of neurogenic tumors of the thoracic inlet: determination of the parent nerve

To investigate the value of magnetic resonance imaging (MRI) in determining the parent nerves of neurogenic tumors in the thoracic inlet, analysis of MR images was performed in nine patients with surgically resected neurogenic tumors in the thoracic inlet (two neurofibromas and one schwannoma of the vagus nerve, three schwannomas of the brachial plexus, and two schwannomas and one ganglioneuroma of the sympathetic nerves). These MR images were compared with surgical and pathologic findings. The multidirectional capability and excellent tissue contrast of MRI facilitated recognition of the location, shape, and extent of the tumors. MRI, which permitted an easy understanding of the spatial relation between the tumors and the subclavian vessels, scalenus muscles, and brachial plexus, was useful in determining the nerves of origin. Two neurofibromas, four of six schwannomas, and one ganglioneuroma were recognized to extend along the axes of the parent nerves on MR images. MRI is useful in determining the parent nerve of neurogenic tumors in the thoracic inlet and is helpful in planning surgical treatment of these tumors.

Prevention of pulmonary embolism by a foot sole pump

We carried out a prospective, randomised study of 62 patients to determine the efficacy of a foot sole pump (the A-V Impulse System) for the prevention of pulmonary embolism (PE) after hip surgery. PE was assessed by pulmonary perfusion scintigraphy before and after operation. We defined a PE as any new scintigraphic defect which was larger than a bronchopulmonary segment. The incidence of PE was 55% in the control group and 21% in the treatment group. The foot sole pump significantly reduced the incidence of PE (p = 0.008) and we encountered no side-effects from its use.

Renaturation of the mature subtilisin BPN' immobilized on agarose beads

We report here another example of renaturation of subtilisin BPN'(Sbtl) by using an immobilized preparation instead of applying a digestible mutant of Streptomyces subtilisin inhibitor (SSI), a proteinaceous inhibitor of Sbtl [M. Matsubara et al. (1994) FEBS Letters 342, 193-196]. The mature Sbtl was immobilized on agarose beads employing the amino group of the protein. After thorough washing, the immobilized Sbtl was subjected to denaturation in 6 M guanidine hydrochloride (GdnHCl) at pH 2.4 for 4 h, followed by renaturation in 2 M potassium acetate at pH 6.5 for 24 h. This denaturation/renaturation cycle was repeated five times. The recovered activity of the renatured immobilized Sbtl settled at a constant level after the third denaturation/renaturation cycle, demonstrating that almost 100% renaturation was attained by use of the immobilized Sbtl. This immobilized Sbtl preparation could well be utilized for the mechanistic study of protein folding. We then found that 2 M potassium acetate was superior to 2 M potassium chloride as a refolding medium and that the ability of SSI to induce the correct shape of the mature Sbtl was lacking in several refolding media in both thermodynamic and kinetic criteria. Thus the main cause for the increase of refolding yield of Sbtl by coexistence of SSI was prevention of the autolysis of Sbtl.

Responses of pituitary and adrenal medulla to insulin-induced hypoglycemia in patients with anorexia nervosa

The responses of pituitary and adrenomedullary hormones to insulin-induced hypoglycemia were studied in 10 patients with anorexia nervosa and 7 control females of comparable age. The increases in plasma GH and PRL were significantly smaller in the patients, while the responses of GH to arginine and of PRL to TRH were indistinguishable. Plasma cortisol attained similar peak levels in both groups with higher basal levels and smaller increments in the patients. The response of plasma epinephrine was markedly lower in the patients, although urinary epinephrine showed similar increase in both groups. These results suggest the possibility that the process by which hypoglycemic stimulus causes pituitary and adrenomedullary hormone secretion is deranged in patients with anorexia nervosa.