Dynamic chemical equilibrium in a polar desert pond: a sensitive index of meteorological cycles.

The dramatic variation in the composition of a brine pond in Antarctica is a seasonal phenomenon. The phase relations of salts in solution are such that hydrologic conditions and temperature determine composition during the austral summer. Temperature is the primary determinant of composition during the winter.

Microfluidic large-scale integration on a chip for mass production of monodisperse droplets and particles.

In this study, we report the mass production of monodisperse emulsion droplets and particles using microfluidic large-scale integration on a chip. The production module comprises a glass microfluidic chip with planar microfabricated 16-256 droplet-formation units (DFUs) and a palm-sized stainless steel holder having several layers for supplying liquids into the inlets of the mounted chip. By using a module having 128 cross-junctions (i.e., 256 DFUs) arranged circularly on a 4 cm x 4 cm chip, we could produce droplets of photopolymerizable acrylate monomer at a throughput of 320.0 mL h(-1). The product was monodisperse, having a mean diameter of 96.4 microm, with a coefficient of variation (CV) of 1.3%. Subsequent UV polymerization off the module yielded monodisperse acrylic microspheres at a throughput of approximately 0.3 kg h(-1). Another module having 128 co-flow geometries could produce biphasic Janus droplets of black and white segments at 128.0 mL h(-1). The product had a mean diameter of 142.3 microm, with a CV of 3.3%. This co-flow module could also be applied in the mass production of homogeneous monomer droplets.

Modulation of motor cortex excitability by peripheral magnetic stimulation of different stimulus sites and frequencies.

Peripheral stimulation is known to influence the state of cortical excitability. The purpose of this study is to investigate whether peripheral magnetic stimulation has similar effects on cortical excitability to transcranial magnetic stimulation (TMS). A magnetic stimulator with a flat figure-of-eight coil was used for both TMS, and peripheral magnetic stimulation applied to the bilateral forearms. TMS was performed on the left primary motor cortex to evaluate influence of the peripheral magnetic stimulation, and motor evoked potential (MEP) was measured from the right first dorsal interosseous. Peripheral magnetic stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz, to the stimulus sites on the right and left supination of the forearm. The effects of peripheral magnetic stimulation were evaluated by comparing the mean MEP amplitude elicited by TMS before and after peripheral magnetic stimulation. We found that cortical excitability varied according to the stimulation site and frequency of the peripheral magnetic stimulation. The inhibition of cortical excitability was observed following 1 Hz peripheral magnetic stimulation over the right forearm (p<;0.001). In contrast, increased cortical excitability was observed using 1 Hz peripheral magnetic stimulation over the left forearm and 10 Hz stimulation over either the right or left forearms. We suggest that peripheral magnetic stimulation has a similar effect to TMS, and can induce both facilitation and inhibition of cortical excitability.

Effect of continuous application of shear stress on liver tissue: continuous application of appropriate shear stress has advantage in protection of liver tissue.

Rapid blood flow changes occur in the liver following a massive resection or in the grafted liver following transplantation, under which shear stress (SS) change induced by the flow change may determine the postoperative results. We observed changes in liver tissue structure and liver-specific function, and consequently assessed SS effect. The cultured liver tissue exposed to continuous application of moderate SS was shown to express and maintain a long-term liver-specific function. There was also evidence showing that destruction of the liver structure was inhibited. However, the cultured liver tissue not exposed to SS or exposed to high SS was shown to lose liver-specific function soon after expression. The liver structure was destroyed in the early stage of incubation. These results suggested that continuous application of appropriate SS has advantages over other types of stresses to protect liver tissue.

Effect of mechanical stress imposition on co-culture of hepatic parenchymal and nonparenchymal cells: possibility of stimulating production of regenerating factor.

The effect of mechanical stress generated within a three-dimensional bioreactor on the co-culture of hepatic parenchymal cells (PC) and hepatic nonparenchymal cells (NPC) was assessed to develop a bioartificial liver that can produce factors accelerating liver regeneration. A rotating radial flow bioreactor was used to provide mechanical stress to a co-culture of PC and NPC that were isolated from rats. They were co-cultured in the reactor under static or dynamic conditions. Albumin, interleukin-6 (IL-6), hepatocyte growth factor (HGF), and lactate dehydrogenase (LDH) were measured at intervals. Electron microscopy was also performed. LDH was not significantly different between the static and mechanical stress-loaded cultures, while albumin and interleukin-6 levels were higher in the latter at all sampling times. Only the co-cultures loaded with mechanical stress produced HGF in the early stage of culture (hours 3 and 6). Histologically, the cells retained their structure when cultured under dynamic conditions. These results suggested that an appropriate level of mechanical stress enabled co-cultures of PC and NPC to produce IL-6, HGF, and other factors that accelerate liver regeneration.

Organization of the human orphan nuclear receptor Nurr1 gene.

Recent reports have revealed that Nurr1 (also known as NOT/TINUR/RNR-1/HZF-3), a member of the steroid/thyroid hormone nuclear receptor superfamily, is predominantly expressed in the midbrain; substantia nigra (SN) and ventral tegmental area (VTA). Nurr1 null mice are born lethal, lacking the midbrain dopamine (DA) neurons, suggesting that Nurr1 is essential for the development and differentiation of midbrain DA neurons. Human Nurr1 gene has been mapped on chromosome 2q22-23, which is reported to associate weakly with schizophrenia. We cloned and sequenced the human Nurr1 gene, which is approximately 8.3kb long, consisting of eight exons and seven introns. Comparisons of the human Nurr1 with the mouse Nurr1, mouse Nur77 and human NOR-1 revealed that their genomic structures were highly conserved. The 5'-flanking region of the human Nurr1 included three transcriptional regulatory elements, cAMP-response element (CRE), CArG-like element and Sp-1 site, which were surrounded by CpG island, and showed a strong homology with the mouse Nurr1. We performed a primer extension analysis using mRNA from HeLa S3 cells stimulated with phorbol 12-myristate 13-acetate (PMA), Ca2+ ionophore A23187 and cycloheximide (CHX) in order to induce the Nurr1 mRNA expression, and determined one transcription initiation site within CRE. The transient transfection assay indicates that the regulatory elements in the 5'-flanking region are robust for mitogen-induced expression of the human Nurr1. Further analysis of the polymorphism of the human Nurr1 gene may reveal the association with diseases characterized by changes of the DA system, such as Parkinson's disease and schizophrenia.

Lack of an association between cystatin C gene polymorphisms in Japanese patients with Alzheimer's disease.

Associations between polymorphisms of the cystatin C gene (CST3) at 5' flanking region and exon 1 in Caucasian patients with late onset AD and exon 1 in a US study of late onset AD have been reported. Clinically diagnosed Japanese patients with AD and Japanese normal control subjects were assessed for the presence of polymorphisms of CST3. The authors could not confirm the previously reported association between CST3 polymorphisms and AD in Japan. Age had no effect on the CST3 genotype.

Decreased GlcNAc 6-O-sulfotransferase activity in the cornea with macular corneal dystrophy.

PURPOSE: Macular corneal dystrophy (MCD) is an autosomal recessive inherited disorder that is accompanied by corneal opacity. Explants from MCD-affected corneas have been reported to synthesize low-sulfated KS, suggesting that sulfate groups attached to KS may play critical roles in maintaining corneal transparency. To clear the biosynthetic defect in the MCD cornea, sulfotransferase activities were determined that are presumably involved in the biosynthesis of KS: galactose-6-sulfotransferase (Gal6ST) activity and N-acetylglucosamine 6-O-sulfotransferase (GlcNAc6ST) activity. METHODS: Gal6ST and GlcNAc6ST activities, which were contained in the corneal extracts from corneas affected by MCD and keratoconus and from normal control corneas, were determined by measuring the transfer of (35)SO(4) from [(35)S]3'-phosphoadenosine 5'-phosphosulfate into the Gal residue of partially desulfated KS and the nonreducing terminal GlcNAc residue of GlcNAcbeta1-3Galbeta1-4GlcNAc (oligo A), respectively. RESULTS: The level of Gal6ST activity in corneal extracts from eyes with MCD, which was measured by using partially desulfated KS as an acceptor, was nearly equal to that in eyes with keratoconus and normal control eyes. In contrast, GlcNAc6ST activity in the extracts from MCD-affected corneas, which was measured by using oligo A as an acceptor, was much lower than in those in corneas with keratoconus and in normal control corneas. CONCLUSIONS: The decrease in GlcNAc6ST activity in the cornea with MCD may result in the occurrence of low- or nonsulfated KS and thereby cause corneal opacity.

Effects of digoxin-specific antibody Fab fragment (Digibind) on blood pressure and renal water-sodium metabolism in 5/6 reduced renal mass hypertensive rats.

The importance of increased endogenous digitalis-like factor (EDLF) in volume-expanded hypertension has been generally agreed. To further clarify the role of EDLF on the development of hypertension and renal water-sodium handling in 5/6 reduced renal mass hypertensive rats (RRM), we studied the effects of acute administration of digoxin-specific antibody Fab fragment (Digibind) in the early phase and the chronic phase of hypertension in RRM. RRM and sham-operated rats were given 1% saline for 1 or 4 weeks. RRM were injected Digibind (60 mg/kg) or vehicle (0.9% saline) intravenously in the first or fourth week under thiobutabarbital anesthesia. All sham-operated rats were administered Digibind under the same condition. Digibind altered neither blood pressure, heart rate, urine volume, nor urinary sodium excretion in sham-operated rats. However, Digibind produced a gradual but significant decline in mean arterial pressure to the level slightly above that in sham-operated rats from 153 +/- 5 to 131 +/- 5 mm Hg in the first week and from 181 +/- 6 to 129 +/- 4 mm Hg in the fourth week without any significant change in heart rate. The decrease in mean arterial pressure at 160 min after Digibind administration in the fourth week (-48 +/- 5 mm Hg) was greater than that in the first week (-22 +/- 4 mm Hg). No differences were observed in urine volume, urinary sodium excretion, or plasma norepinephrine concentration between Digibind and vehicle-treated RRM in either week. These data suggest that EDLF would contribute to both the early and chronic phase in the development of hypertension in RRM.

The effects of an angiotensin-converting enzyme inhibitor and an angiotensin II receptor antagonist on insulin resistance in fructose-fed rats.

The aim of this study was to compare the effects of an angiotensin-converting enzyme (ACE) inhibitor and an angiotensin II receptor (AT) antagonist on insulin resistance, especially on muscle fiber composition in fructose-induced insulin-resistant and hypertensive rats. Six-week-old male Sprague-Dawley rats were fed either normal rat chow (control) or a fructose-rich diet (FFR). For the last two weeks of a six-week period of either diet, the rats were treated with gum arabic solution as a vehicle (control or FFR), angiotensin-converting enzyme inhibitor (FFR+ACE), temocapril (1 mg/kg/ day) or an angiotensin II receptor antagonist (FFR+AT), CS-866 (0.3 mg/kg/day), by gavage, and then the euglycemic hyperinsulinemic glucose clamp technique was performed to evaluate insulin sensitivity. At the end of the glucose clamp, the soleus muscle was dissected for determination of the muscle fiber composition by ATPase methods. Blood pressure at the glucose clamp in the FFR group was significantly higher than that of the control group, and both temocapril and CS-866 significantly lowered the blood pressure of the FFR group. The average rate of glucose infusion during the glucose clamp, as a measure of insulin sensitivity (M value), was significantly lower in the FFR rats compared to the controls (15.4 +/- 0.4, 10.9 +/- 0.6 mg/kg/min, for control and FFR, respectively, P < .01). Both temocapril and CS-866 partially improved the M values compared to FFR (13.2 +/- 0.7, 12.8 +/- 0.5 mg/kg/min, for FFR+ACE, FFR+AT, respectively, P < .01 compared with FFR, P < .05 compared with control). The composite ratio of type I fibers of the soleus muscle was decreased significantly in the FFR rats compared with the controls (82% +/- 2%, 75% +/- 2%, for control and FFR, respectively, P < .01), and both temocapril and CS-866 restored a composite ratio of type I fibers to the same level as that of the controls (81% +/- 1%, 80% +/- 1% for FFR+ACE and FFR+AT, respectively). The M value was significantly correlated with the composition of type I and type II fibers. These results suggest that the fiber composition of skeletal muscle is correlated to insulin resistance, and that both ACE inhibitors and AT antagonists may modulate the muscle fiber composition in a hypertensive and insulin-resistant animal model, fructose-fed rats, to the same extent.

Measurement of activities of human serum sulfotransferases which transfer sulfate to the galactose residues of keratan sulfate and to the nonreducing end N-acetylglucosamine residues of N-acetyllactosamine trisaccharide: comparison between normal controls and patients with macular corneal dystrophy.

Human serum sulfotransferase activities were measured in normal controls and patients with macular corneal dystrophy (MCD), an inherited disorder characterized by the decreased sulfation of keratan sulfate in the corneal stroma and serum, using two kinds of acceptor: partially desulfated keratan sulfate and a trisaccharide with a GlcNAc residue at the nonreducing terminal, GlcNAcbeta1-3Galbeta1-4GlcNAc. When partially desulfated keratan sulfate was used as the acceptor, only sulfotransferase activity which transfers sulfate to position 6 of the Gal residues was detected. In contrast, when GlcNAcbeta1-3Galbeta1-4GlcNAc was used as the acceptor, sulfotransferase activity which transfers sulfate to position 6 of the nonreducing terminal GlcNAc residue could be detected. Although keratan sulfate levels in the sera of MCD patients determined by ELISA were much lower than those in normal controls, there were no detectable differences in either the sulfotransferase activity responsible for the sulfation of position 6 of Gal residues or that responsible for the sulfation of position 6 of nonreducing end GlcNAc residues between normal controls and MCD patients. These results suggest that the sulfotransferase involved in the sulfation of keratan sulfate, which is assumed to be deficient in MCD patients, may not be secreted into the serum, and that direct measurement of the sulfotransferase activity present in affected tissues such as the cornea instead of serum may be necessary to confirm the postulated deficiency in the biosynthesis of keratan sulfate in MCD.

Effects of the Chinese medicine, TSJN on insulin resistance and hypertension in fructose-fed rats.

The aim of this study was to determine the effect of Tang-Shen-Jiao-Nang (TSJN), a Chinese medicine used to treat diabetes mellitus, on insulin resistance and hypertension in fructose-fed rats (FFR). Six-week-old male Sprague-Dawley rats were fed either normal rat chow (control) or a fructose-rich chow (FFR) for 6 wk. For the last 2 or 4 wk of a 6-wk period of either diet, the rats were treated by gavage with gum arabic solution as a vehicle (control or FFR) or TSJN (800 mg/kg/d; FFR+TS), and then we performed the euglycemic hyperinsulinemic glucose clamp technique to estimate insulin sensitivity. Systolic blood pressure was measured weekly for 6 wk. At the end of the glucose clamp, the soleus muscle was dissected out for determination of muscle fiber composition by ATPase methods. Systolic blood pressure was elevated at 2 wk after the start of the fructose-rich chow feeding and persisted thereafter throughout the study. Systolic blood pressure during the glucose clamp in the FFR group was significantly higher than that in the control group. Although there was no effect on systolic blood pressure in rats treated with TSJN for the last 2 wk of their 6-wk diet, those treated with TSJN for the last 4 wk of their 6-wk diet had lower systolic blood pressure than did the rats in the FFR group. The average rate of glucose infusion during the glucose clamp, as a measure of insulin sensitivity (M value), was significantly lower in the FFR than in the controls (10.9 +/- 0.6 and 15.4 +/- 0.4, mg/kg/min, for FFR and controls, respectively; p< 0.01). Treatment with TSJN for 2 wk significantly improved the M value compared to that of the control level (15.1 +/- 0.5 mg/kg/min). The composite ratio of type I fibers in the soleus muscle was significantly decreased in the FFR compared to controls (75.0 +/- 1.7 and 81.7 +/- 1.5%, for FFR and controls, respectively; p< 0.01), and treatment with TSJN for 2 wk led to a recovery composite ratio of type I fiber to the same level as that of the control group (78.7 +/- 1.7% in FFR + TS). The M value was significantly correlated with the compositions of type I and type II fibers (for type I fibers, r= 0.45, p < 0.01, for type II fibers, r= -0.44, p< 0.05). These results suggest that the Chinese medicine TSJN may improve insulin resistance, lower the systolic blood pressure, and modulate muscle fiber composition in hypertensive and insulin-resistant fructose-fed rats.

The contribution of nitric oxide to diuretic and natriuretic effects of renal kinins in normotensive rats.

We have reported that diuresis and natriuresis due to increase in renal kinins induced by the neutral endopeptidase 24.11 (NEP) inhibitor were attenuated by nitric oxide (NO) synthase inhibitor. To further clarify the water-sodium excretory mechanism of renal kinins, we estimated NO2+NO3 (NOx) and cGMP in plasma and urine with and without a specific NEP inhibitor, thiorphan. P-aminohippuric acid (PAH) and inulin were injected into male Sprague-Dawley rats. Vehicle (n = 8) or thiorphan (30 mg/kg, n = 10) was injected after the control period. Mean blood pressure (MBP), plasma and urinary PAH, inulin, NOx and cGMP, urinary volume (UV) and urinary sodium excretion (UNaV) were measured before and after injection of the reagents. MBP, renal plasma flow and glomerular filtration rate were not affected by thiorphan. Plasma NOx and cGMP with thiorphan did not differ from the vehicle, while urinary NOx and cGMP increased. None of the variables were affected by vehicle. UV and UNaV were higher with thiorphan than with vehicle. Positive correlation was found between urinary deltaNOx and deltacGMP. Each urinary deltaNOx and deltacGMP was significantly correlated to both deltaUV and deltaUNaV. Urinary NOx and cGMP were increased while maintaining correlations to UV and UNaV, but plasma NOx and cGMP were not affected by thiorphan. This implies that the mechanism of water-sodium excretion induced by NEP inhibitor is mediated by renal NO. Therefore, renal NO may contribute to the diuretic and natriuretic effects of renal kinins.

Renal dopaminergic activity in patients with primary aldosteronism.

To clarify the role of renal dopaminergic activity in patients with primary aldosteronism (PA), urinary excretion of free dopamine (DA) and the conversion ratio of DA from l-dopa in the kidney were investigated in 8 patients with PA and 10 normotensive subjects (NT). All subjects were hospitalized and received a standard diet (Na 120 mEq, K 75 mEq/day) and 2 h renal clearance test was performed. Plasma l-dopa concentration (p-DOPA), creatinine clearance (Ccr), urinary excretion of sodium (UNaV) and DA (uDA) as well as fractional excretion of sodium (FENa) were measured. No significant difference was found in UNaV or FENa between NT and PA, or between before and after adrenalectomy (Adx) in PA. UDA was significantly higher in PA than NT, and decreased significantly after Adx. There was no difference in the product of Ccr X p-DOPA between NT and PA, or between before and after Adx in PA. The ratio of uDA/(Ccr X p-DOPA) was significantly higher in PA than NT. After Adx this ratio decreased significantly to the normal range. These results suggest that (1) renal dopaminergic activity is augmented and contributes to the escape phenomenon in PA, and (2) augmented renal DA production in PA might be caused by an increase of conversion to DA from l-dopa at the renal proximal tubules.

Melatonin inhibits Arg-vasopressin release via MT(2) receptor in the suprachiasmatic nucleus-slice culture of rats.

The effect of melatonin on the release of Arg-vasopressin (AVP) was analyzed in a suprachiasmatic nucleus-slice explant culture. The release of AVP into the culture medium exhibited a circadian rhythm, with higher level during the subjective day and lower level during the subjective night. Melatonin (500 nM) inhibited the release of AVP. Luzindole, a MT(2) (Mel 1b) melatonin receptor antagonist, attenuated the effect of melatonin on the AVP release. Results indicate that the inhibition of AVP release by melatonin in the suprachiasmatic nucleus-slice culture depends at least in part on the melatonin MT(2) receptor.

Selective concentration of gold in water to a polystyrene-embedded fiber disk with polyoxyethylene(10)-p-isononylphenyl ether.

A new surfactant-mediated separation method was developed for concentrating traces of gold ion in water. The methodology is based on the combination of selective complexation of gold(III) with polyoxyethylene(10)-p-isononylphenyl ether, PONPE-10, and strong binding of surfactant complex to hydrophobic polystyrene resins embedded in a PTFE fiber disk (Empore disk). A 400-fold concentration of gold(III) was achieved by 400 ml load of the sample containing 0.01% (w/v) PONPE-10 and 0.10 M nitric acid and by the subsequent elution with 1.0 ml of aqueous buffer solution of 0.01 M N-(dithiocarboxyl)sarcosine diammonium. Traces of gold (0.40 ng/l) in river water samples were successfully determined with inductively coupled plasma MS.

Anticancer agents adsorbed by activated carbon particles, a new form of dosage enhancing efficacy on lymphnodal metastases.

A new dosage form consisting of small activated carbon particles which adsorb Aclacinomycin A, Adriamycin, Mitomycin C or Pepleomycin was prepared in order to deliver larger amounts of anticancer agents to the lymph nodes through the high ability of lymphatics to adsorb particles. Animal experiments showed that: The LD50 values of the new dosage form were higher than those of the dosage in solution. The concentration of agents in lymph nodes was maintained at a higher level in the new dosage form than in solution form. Clinically 33% of lymphnodal metastatic lesions became degenerative or inflammatory after a single administration.

Local injection of anti-cancer drugs bound to carbon particles for early gastric cancer--a pilot study.

BACKGROUND/AIMS: A new dosage formulation consisting of an anti-cancer drug bound to activated carbon particles was developed for a local injection against early gastric cancer so that the dosage formulation yields chemotherapeutic effects selectively to the lymph node metastases as well as to the primary lesion. METHODOLOGY: As a pilot study, the new dosage formulation, total of 50-200 mg of methotrexate only or total of 200 mg of methotrexate plus 8 mg of mitomycin C, was injected into the primary lesions and the adjacent gastric wall of 8 patients with early gastric cancer, guided by a gastrofiberscope before gastrectomy. The surgically resected specimens were examined histologically for the therapeutic effects on the primary lesion and its nodal metastasis. RESULTS: The therapeutic effects were seen in 2 of 4 lymph node metastases (50%) and 5 of 8 of the primary lesions (63%), as confirmed histologically with degeneration and/or necrosis. CONCLUSIONS: Preoperative local injection of the new dosage formulation will be useful to give chemotherapeutic effects on the potential metastases in the regional nodes as well as to the primary lesion.

Differential diagnosis of adrenal tumour and upper pole renal tumour by I-131 cholesterol adrenocortical scintigraphy.

A 27-year-old housewife with right hypochondralgia was admitted for treatment of a huge right adrenal or upper pole renal tumour. The tumour measured 10 x 8 x 8 cm and was hypovascular. The main blood supply derived from the right adrenal artery which originated from the abdominal aorta just proximal to the right renal artery. Although several diagnostic imaging studies suggested that the tumour arose from the right adrenal gland, the bilateral adrenal glands were equally visualized on I-131 cholesterol adrenocortical scintigraphy. After surgery and pathological examination, the tumour proved to be a renal cell cancer, while the right adrenal gland was intact. This case demonstrates that adrenocortical scintigraphy is useful in the differentiation of adrenal and renal tumours when a large tumour occupies the upper pole of the kidney or adrenal gland.

Clinical results of tubeless cutaneous ureterostomy by Toyoda's method.

Tubeless cutaneous ureterostomy by Toyoda's method was conducted in 67 ureters from 43 patients during the last 9 years. Subjects included 30 males and 13 females, with an average age of 61.4 years. Most of them were afflicted with malignant tumors in the bladder, rectum, prostate, or uterus. For bilateral ureterostomy, the double-barrel method was performed in which the stoma was made at the same site in both the right and left ureters. Among 60 ureters in which pre- and postoperative changes in the renal pelvis could be traced by IVP, satisfactory results were obtained in 16 of 20 ureters treated by unilateral surgery. Of the 40 ureters treated by the double-barrel method, moderate or severe pyeloectasis was observed in 3 of the 20 ureters on the side of the stoma, while moderate pyeloectasis was seen in 3 of 20 ureters of the side opposite the stoma, and severe pyeloectasis or loss of renal function was noted in 5. Thus, renal function on the side opposite the stoma was frequently influenced by the procedure. A patient who died of disseminated intravascular coagulation syndrome soon after the operation was excluded from analysis. Tubeless cutaneous ureterostomy could be conducted in 39 of 42 patients (92.8%), excluding one whose stoma and its periphery were covered with severe inflammatory granulation and 2 with ureteral constriction.