Estimation of the kinetic-optimized stimulus intensity envelope for drop foot gait rehabilitation.

The purpose of present study is to estimate the optimal stimulus intensity envelope for drop foot rehabilitation based on a kinetic perspective. The voluntary and electric-stimulated elicited dorsiflexion torque responses of 11 healthy subjects were measured. During dorsiflexion, we recorded the tibialis anterior (TA) electromyography (EMG) or the stimulation intensity at four angles of the ankle joint. From these measurements, we derived two approximate equations that estimate dorsiflexion produced by either voluntary contraction or by electrical stimulation using a sigmoid function and a stepwise-regression analysis. We then tested the predictive capability of the model using Pearson correlation. Both equations indicated high correlation coefficients. Finally, we derived a relation between the TA EMG amplitude and stimulation intensity. From the obtained equation, we determined the optimal stimulus amplitude. We assume that the derived stimulus intensity envelope, calculated from EMG amplitude and angle of ankle joint, satisfies kinetic demand.

Effect of voluntary contraction with electrical stimulation to antagonist muscle on agonist H-reflex.

OBJECTIVE: Hybrid exercise (HE) was designed to use the force generated by an electrically stimulated antagonist to provide resistance to a volitionally contracting agonist. The purpose of this study was to measure and compare the soleus H-reflex before and after HE or conventional resistance exercise (CRE). METHODS: The experiments were carried out in 18 healthy subjects (5 men and 13 women; 19-30 yr), who were divided into 2 groups of 9 for each protocol (HE or CRE). The exercise sessions lasted for 15 consecutive minutes. The soleus Hmax/Mmax was measured before and after the HE or the CRE. RESULTS: In the HE group, although there was no significant difference, the soleus Hmax/Mmax after the exercise increased compared with before the exercise (54.7 +/- 10.2% to 59.0 +/- 14.5%). On the other hand, the soleus Hmax/Mmax decreased in the CRE group (61.8 +/- 14.9% to 55.7 +/- 16.1%). In the rate of change of the soleus Hmax/Mmax, the result for the HE group was significantly higher than in the CRE group (108.0 +/- 11.7% and 89.1 +/- 8.0%, respectively) (p < 0.001). CONCLUSION: Our results show a clear difference of the neurophysiological mechanism between HE and CRE. Thus, HE might not be an alternative method for CRE.

Detoxification mechanism of heavy metals in marine mammals and seabirds: interaction of selenium with mercury, silver, copper, zinc, and cadmium in liver.

Subcellular distribution of mercury, selenium, silver, copper, zinc, and cadmium was determined in the liver of northern fur seals (Callorhinus ursinus), black-footed albatrosses (Diomedea nigripes), and Dall's porpoises (Phocoenoides dalli). Mercury, selenium, and silver were preferentially accumulated in nuclear, lysosomal, and mitochondrial fraction with an increase in their hepatic concentrations, whereas copper, zinc, and cadmium were accumulated mainly in cytosol with an increase in the hepatic concentrations for all three species. To gain insight into the existing state of the metals, they were extracted with four extractants--sodium dodecylsulfate (SDS); 2-mercaptoethanol; 2-mercaptoethanol + guanidinium thiocyanate; and copper sulfate (CuSO4)--at several concentrations from nuclear, lysosomal, and mitochondrial fraction in liver from a specimen of northern fur seal. Extraction efficiencies of the metals for 2-mercaptoethanol + guanidinium thiocyanate and CuSO4 were much higher than those for SDS and 2-mercaptoethanol. Also, for all individuals of the three species, metals were extracted by the three extractants--2% SDS; 0.25 mol/L 2-mercaptoethanol + 5 mol/L guanidinium thiocyanate; and 0.1 mol/L CuSO4--from nuclear, lysosomal, and mitochondrial fraction of liver. In the northern fur seals with higher concentration of mercury, the molar ratio of selenium to mercury approached unity in the nonextractable fraction of 0.25 mol/L 2-mercaptoethanol + 5 mol/L guanidinium thiocyanate, suggesting the possible formation of mercuric selenide (HgSe) with increasing hepatic concentration. Because the nonextractable content of mercury and its distribution were larger for black-footed albatross than those for the other two species, it was suggested that the black-footed albatross has a stronger ability to form a stable compound(s) of mercury in the liver. It is notable that the existing state of silver was similar to that of mercury as judged by their subcellular distribution and the extraction tests, suggesting that silver also interacted with selenium in the liver of marine animals used in this study.

Effects of extracellular Ca2+ on phagocytosis and intracellular Ca2+ concentrations in polymorphonuclear leukocytes of postpartum dairy cows.

The aim of this study was to determine the effects of extracellular Ca(2+) concentration ([Ca(2+)](e)) on phagocytosis and intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine polymorphonuclear leukocytes (PMNs). The experiments were performed by using blood samples from parturient paretic and clinically normal parturient cows and manipulating the [Ca(2+)](e) in vitro. Phagocytosis by PMNs (with and without stimulation with phorbol myristate acetate and inhibition with cytochalasin B) and resting [Ca(2+)](i) were significantly lower in parturient paretic cows. Repletion of Ca(2+) in the extracellular media for the samples from these animals increased phagocytosis and resting [Ca(2+)](i). In the blood of clinically normal parturient cows, decreasing the [Ca(2+)](e) decreased phagocytosis and resting [Ca(2+)](i) in PMNs, but increasing the [Ca(2+)](e) did not affect phagocytosis. These results suggest that the hypocalcemic condition of parturient paretic cows in vivo causes decreased phagocytosis and resting [Ca(2+)](i) in PMNs, which may partly contribute to greater susceptibility to infection.

Synthesis and biological activity of KCB-328 and its analogues: novel class III antiarrhythmic agents with little reverse frequency dependence.

A series of 3,4-dimethoxyphenethylamine derivatives was prepared, and their prolongation effects on effective refractory period of contractile response (ERPc) and action potential duration (APD) in isolated guinea-pig papillary muscles at 1 Hz and 3 Hz were examined. SAR studies led to the identification of KCB-328 (51) which is a novel class III antiarrhythmic agent with little reverse frequency dependence.

Neonatal hyperbilirubinemia and a common mutation of the bilirubin uridine diphosphate-glucuronosyltransferase gene in Japanese.

Neonatal hyperbilirubinemia, which is prevalent among Asian peoples, has been considered as a physiological phenomenon, and its metabolic basis has not been clearly explained. Gilbert syndrome is a common inherited disease of unconjugated hyperbilirubinemia due to decreased bilirubin uridine diphosphate-glucuronosyltransferase (B-UGT), and its role in neonatal jaundice has recently been considered. We have previously reported that the Gly71Arg mutation of the B-UGT gene associated with Gilbert syndrome is prevalent in Japanese, Korean, and Chinese populations and was more frequently detected in neonates with severe hyperbilirubinemia than in control subjects. We have studied 159 Japanese full-term neonates, evaluating the relationship between the B-UGT genotype and the severity of jaundice, as assessed with a transcutaneous bilirubinometer. The gene frequency of the Gly71Arg mutation in these neonates was 0.19, and neonates carrying the Gly71Arg mutation had significantly increased bilirubin levels on days 2-4, manifested in a gene dose-dependent manner. The frequency of the Gly71Arg mutation was 0.47 in the neonates who required phototherapy (i.e., those with more severe hyperbilirubinemia), significantly higher than 0.16 in the neonates who did not require the therapy. The gene frequency of the TA repeat promoter polymorphism, the (TA)7 mutation, was 0.07, and neonates carrying this mutation did not have an increase in bilirubin. These results suggested that the Gly71Arg mutation contributes to the high incidence of neonatal hyperbilirubinemia in Japanese.

Antiarrhythmic effects of a novel class III drug, KCB-328, on canine ventricular arrhythmia models.

KCB-328 is a newly synthesized class III drug. To determine whether this drug has antiarrhythmic or proarrhythmic effects, we used canine ventricular arrhythmia models induced by coronary ligation and reperfusion, programmed electrical stimulation (PES), two-stage coronary ligation, digitalis, or epinephrine. KCB-328, in an intravenous infusion of 0.5 mg/kg/30 min, prolonged the QTc interval only 11%, but had antiarrhythmic effects on the reentry arrhythmias induced by PES (12 of 12 dogs with old myocardial infarction; p < 0.05). KCB-328, in an infusion of 1 mg/kg/h, suppressed the occurrence of fatal ventricular fibrillation (VF) induced by coronary ligation and reperfusion under either halothane anesthesia (p < 0.05) or pentobarbital anesthesia (p < 0.05). Under the halothane anesthesia, KCB-328 alone showed proarrhythmic effects [i.e., induction of ventricular premature contractions (VPCs)], but it did not induce a more severe effect such as torsades de pointes-type ventricular tachycardia (VT). In addition, KCB-328 had weak antiarrhythmic effects on the automaticity arrhythmias induced by 24-h coronary ligation but was effective neither on 48-h coronary ligation arrhythmias nor on the digitalis- and epinephrine-induced arrhythmias. Our results indicate that KCB-328 has powerful antiarrhythmic effects with fewer proarrhythmic potencies.

6-Methylsulfinylhexyl isothiocyanate and its homologues as food-originated compounds with antibacterial activity against Escherichia coli and Staphylococcus aureus.

Cruciferae plants, banana and coriander each showed antibacterial activity. The highest activity among the food-stuffs tested was found in the stems of wasabi. An ethereal extract from wasabi stems had potent antibacterial activity and we isolated the active compound from the extract. Instrumental analysis identified the compound as 6-methylsulfinylhexyl isothiocyanate. Some homologues of 6-methylsulfinylhexyl isothiocyanate were also active against Escherichia coli and Staphylococcus aureus.

Facilitation of passive avoidance response by newly synthesized cationized arginine vasopressin fragment 4-9 in rats.

The effects of a newly synthesized cationized arginine vasopressin fragment 4-9 analogue (C-AVP-(4-9)) on learning and memory in rats were studied by the passive avoidance test. C-AVP-(4-9) and its parent peptide, arginine vasopressin fragment 4-9 (AVP-(4-9)), a well known potent neuropeptide, were subcutaneously injected 1.5 hr prior to the retention test. The most effective doses of C-AVP-(4-9) and AVP-(4-9) were 8.6 x 10(-2) and 1.3 nmol/kg, respectively. To evaluate the distribution of C-AVP-(4-9) in the control nervous system (CNS), apparent tissue-plasma concentration rations (Kp.app) of intravenously administered radioiodinated C-AVP-(4-9) (125I-C-AVP-(4-9)) in the CNS in mice were determined. At the apparent steady state of plasma concentration of 125I-C-AVP-(4-9), the Kp.app values of the 125I-C-AVP-(4-9) in the cerebrum, cerebellum and spinal cord were over 12 times higher than that of the vascular space marker which slightly penetrates the BBB. Moreover, the rat cerebral homogenate converted C-AVP-(4-9) into its parent peptide AVP-(4-9). These results suggest that the potent effects of C-AVP-(4-9) on learning and memory may be due to AVP-(4-9) generated as a result of distribution and metabolism of peripherally administered C-AVP-(4-9) in the CNS.

[Cross-reactivity between bromelain and soluble fraction from wheat flour].

It is revealed that patients allergic to a water-soluble fraction from wheat flour were sensitive to pineapple enzyme, bromelain. Since bromelain has a high similarity to other SH-proteases such as papain, it may imply that the patients may recognize varieties of other SH-proteases as the epitope.

Modification of wheat flour with bromelain and baking hypoallergenic bread with added ingredients.

Based on the wheat glutenin IgE-binding epitope, Gln-Gln-Gln-Pro-Pro, a practical method is proposed for the production of hypoallergenic wheat flour. Bromelain was found effective for decomposing the epitope structure. In practice, soft flour was mixed with water dissolving bromelain and the mixture was incubated at 37 degrees C for 4 h. The result of IgE-ELISA (enzyme-linked immunosorbent assay) suggested negative allergenicity. A mixture of bromelain-modified flour, glucose, citric, acid, a surfactant and sodium hydrogen carbonate was baked to produce hypoallergenic bread, resembling English muffins.

Analysis of the t(6;11)(q27;q23) in leukemia shows a consistent breakpoint in AF6 in three patients and in the ML-2 cell line.

The t(6;11)(q27;23) is one of the most common translocations observed in patients with acute myeloid leukemia (AML). The translocation breakpoint involves the MLL gene, which is the human homolog of the Drosophila trithorax gene, at 11q23 and the AF6 gene at 6q27. Reverse transcriptase-polymerase chain reaction (RT-PCR) using an MLL sense primer and an AF6 antisense primer detected the MLL/AF6 fusion cDNA from three leukemia patients with the t(6;11) [two AML and one T-acute lymphoblastic leukemia (ALL)] and one cell line. The fusion point in the AF6 cDNA from these cases is identical, regardless of the leukemia phenotype. The ML-2 cell line, which was established from a patient with AML that developed after complete remission of T-cell lymphoma, has retained an 11q23-24 deletion from the lymphoma stage and has acquired the t(6;11) with development of AML. The ML-2 cells have no normal MLL gene on Southern blot analysis, which indicates that an intact MLL gene is not necessary for survival of leukemic cells.

Effect of supplemental lactoferrin with ferrous iron on iron status of newborn calves.

Data for 18 male and 18 female calves, born from primiparous and multiparous cows, were collected to determine the effect of supplemental lactoferrin and FeSO4 for 5 d after parturition on the Fe status of calves. Dietary treatments were 1) untreated, 2) 40 mg of Fe/d as FeSO4, and 3) 40 mg of Fe as FeSO4 plus 5 g of lactoferrin/d. Blood hematocrit and hemoglobin of calves born from primiparous cows at d 1 of age were lower than those of calves born from multiparous cows, but not different from those of their dams. Blood hematocrit and hemoglobin of male calves at d 1 of age were lower than those of female calves. Plasma Fe of primiparous cows at parturition was lower than that of multiparous cows, but plasma Fe of calves was not affected by parity of dam and sex of calf. Blood hematocrit and hemoglobin of untreated calves decreased from 1 to 10 d of age. Blood hematocrit and hemoglobin of calves treated with Fe of Fe plus lactoferrin increased from 2 to 10 d of age. Blood hematocrit and hemoglobin of calves treated with Fe plus lactoferrin were higher than those of calves treated with Fe at d 6 of age. Plasma Fe of calves treated with Fe or Fe plus lactoferrin increased temporarily at d 2 of age. Plasma Fe of calves treated with Fe plus lactoferrin at d 2 of age was lower than that of calves treated with Fe, but, at d 6 and 10 of age, plasma Fe of calves treated with Fe plus lactoferrin were higher.

Effect of twinning and supplemental iron-saturated lactoferrin on iron status of newborn calves.

Data from 53 calves by embryo transfer were collected to determine the effect of twinning and supplemental Fe-saturated lactoferrin or FeSO4 for 5 d after parturition on iron status of calves. Blood hematocrit and hemoglobin of multiple calves born from multiparous cows at d 1 postpartum were lower than those of single calves born from multiparous cows, although those of their dams were not different. Plasma Ca, inorganic P, Mg, Zn, and Cu were similar for single and multiple calves or for calves born from primiparous and multiparous cows. Blood hematocrit and hemoglobin of untreated calves decreased from 1 to 6 d postpartum. Blood hematocrit of calves treated with 40 mg of Fe/d as FeSO4 increased from 1 to 10 d postpartum, and blood hemoglobin of calves treated with 20 or 40 mg of Fe/d as ferrous Fe increased from 1 to 10 d postpartum. Blood hematocrit and hemoglobin of calves treated with 20 mg of Fe/d as Fe-saturated lactoferrin remained nearly constant for 10 d postpartum. Serum Fe of calves increased immediately after the treatment with 20 or 40 mg of Fe as FeSO4, but serum Fe of calves treated with lactoferrin was not affected. Thus, ferrous Fe may be more effective than Fe-saturated lactoferrin in elevating blood hematocrit and hemoglobin in newborn calves.

Most toxic and highly bioaccumulative PCB congeners in cod-liver oil of Baltic origin processed in Poland during the 1970s and 1980s, their TEQ-values and possible intake.

Five samples of cod-liver oil of Baltic origin, collected between 1971 and 1989, have been analysed for 15 selected polychlorinated biphenyl (PCB) congeners including the ten most toxic non-, mono-and di-ortho coplanar, IUPAC nos. 60, 77, 105, 118, 126, 138, 169 and 170 and another five highly bioaccumulative members (IUPAC nos. 28 + 32, 52, 101, 153 and 180). The method of measurement was capillary GC-MS. Cod-liver oils collected in 1971, 1975, 1980, 1985 and 1989 contained 3.0, 2.5, 6.7, 2.9 and 3.1 micrograms g-1 respectively, of selected PCBs (IUPAC nos. 28 + 32, 52, 101, 138, 153 and 180). The concentration of total PCBs in these oils were 8.0, 6.7, 17, 8.0 and 9.5 micrograms g-1, respectively for the years 1971-89, which indicates both persistency and steady state of these pollutants in the Baltic Sea. These cod-liver oils also showed high concentrations of the ten most toxic coplanar PCBs; their TEQ-values (Safe, 1990) were between 900 and 2300 micrograms g-1. 2,3', 4,4',5-pentachlorobiphenyl (IUPAC no. 118), 2,3,3', 4,4'-pentachlorobiphenyl (IUPAC no. 105) and 3,3',4,4',5-pentachlorobiphenyl (IUPAC no. 126) contributed most to the total TEQs of the ten coplanar members, occupying 47, 19 and 17%, respectively (totally 83%). A possible intake of these toxic PCBs from cod-liver oil by children or adults was estimated to be between 4.5 and 35 pg TEQ daily and for total PCBs between 34 and 260 micrograms daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of parity on colostral mineral concentrations of Holstein cows and value of colostrum as a mineral source for newborn calves.

Colostrum samples for 93 Holstein cows and blood samples of 49 newborn calves fed only colostrum for 1 wk postpartum were collected to clarify the effect of parity on colostral and plasma mineral concentration. The concentrations of colostral Ca, P, Mg, Na, Fe, Zn, Cu, and Mn were highest at parturition and decreased rapidly by 24 h postpartum. Three cows had an extremely low concentration of colostral Ca and P. Colostral Ca, P, and Mg at parturition decreased as lactation number increased and stabilized after the third lactation. Colostral Zn of primiparous cows at parturition tended to be higher than that of multiparous cows, but no effect on colostral Fe, Cu, and Mn was due to parity. Blood hematocrit and hemoglobin of newborn calves increased with greater lactation number of the dams, and the blood values were lowest at d 6 postpartum for calves born from primiparous cows. Plasma Ca of calves born from primiparous cows tended to be higher than those of calves from multiparous cows, and blood hemoglobin and plasma inorganic P concentrations of female calves were higher than those of males at d 1 postpartum. Blood hematocrit and hemoglobin and plasma Mg decreased with time postpartum, but plasma Zn and Cu increased. In general, lactation number was a major factor for alteration of colostral minerals of cows and mineral status of newborn calves.

Decreased hypothalamic and medullary GABA turnover in spontaneously hypertensive rats.

OBJECTIVE: The aim was to assess whether Gamma-aminobutyric acid (GABA) neurone activities in the central nervous system, especially in the hypothalamus and medulla oblangata, are altered in hypertension. METHODS: Central GABA content and turnover rate were measured in spontaneously hypertensive rats (SHR) and their normotensive Wistar Kyoto controls (WKY). GABA content was determined with high performance liquid chromatography, and in vivo GABA turnover rates were estimated by GABA accumulation after injection of amino-oxyacetic acid, a selective inhibitor of GABA degrading system. Two groups of nine week old male rats (32 SHR and 32 WKY) were used. RESULTS: GABA concentrations in cerebrospinal fluid were lower in SHR than in WKY. Since hypothalamus and medulla oblongata are the possible active sites of this system, basal GABA contents and in vivo GABA turnover rates were measured in hypothalamus and medulla oblongata. Basal GABA content in the medulla oblongata and hypothalamus was almost equal in SHR and WKY. On the other hand, GABA turnover rates were significantly lower in SHR than in WKY in both the hypothalamus and the medulla. CONCLUSIONS: Since it is known that GABA is an inhibitory neurotransmitter in the central nervous system and that it controls autonomic and cardiovascular activities, the findings suggest that the decreased hypothalamic and medullary GABAergic activities may permit sympathetic hyperactivity to contribute to the increase in blood pressure in SHR.

Cytoprotective effect of dilazep on hydrogen peroxide-perturbed vascular endothelial cells.

The effect of dilazep and dimethyl thiourea (DMTU) on the hydrogen peroxide-derived injury of culture pulmonary artery epithelial cells (CPAEC) was assessed by colorimetric assay of MTT formazan (MTT formazan assay). When CPAEC were treated with hydrogen peroxide, neither cell lysis nor detachment of the cells from surface of the well was observed. However, the MTT formazan formation was decreased in a time and dose dependent manner. The decrease in the formation was significantly suppressed in the presence of dilazep (0.1 to 10 microM) or DMTU (0.01 to 0.3 microM). CPAEC treated with hydrogen peroxide in the same way enhanced an activation of prothrombin, and this enhancement was significantly inhibited in the presence of dilazep (1 to 3 microM). These data indicate that dilazep exerts a cytoprotective effect against challenges of intracellular oxidant produced by hydrogen peroxide and suppresses augmented procoagulant activity of injured cells.

Increased extracellular concentration of norepinephrine in the hypothalamus by sinoaortic denervation.

To determine whether baroreflex can affect the norepinephrine system in the hypothalamus, the extracellular concentration of norepinephrine were measured by the brain dialysis technique in sinoaortic denervated rats (SAD). Twenty-four hours after sinoaortic denervation, systolic blood pressure and heart rate were significantly elevated, and norepinephrine concentration in perfusate of the posterior hypothalamus was significantly higher in SAD rats than in sham-operated rats. These results suggest that baroreflex could modify the activity of noradrenergic neuron projecting to the posterior hypothalamus.