The content of carbohydrates in larval stages of Anisakis simplex (Nematoda, Anisakidae)

Summary The content of carbohydrates in L₃ and L₄ larvae of Anisakis simplex (defined by Rokicki J.) was studied. Glycogen and trehalose were their major reserve sugars. The concentration of saccharides in L₄ larvae was 2–3-times higher than in L₃ larvae. The content of glycogen was 3.68 ± 1.24 mg/g tissue in L₃ larvae and 11.68 ± 1.21 mg/g tissue in L₄ larvae. Trehalose represented 16.17 % of soluble sugars in L₃ larvae and 43.04 % in L₄ larvae. The contents of maltose, higher polymers of glucose (1.5-times) and myoinositol (1.2-times) in L₄ were higher than in L₃ larvae. After starving the L₃ larvae of the parasite for 48 h at 4°C, the contents of trehalose increased 5-fold and that of glycogen by 20 %, while at 37°C the contents of glycogen was ca. 30 % higher and that of trehalose 40 % less than in larvae freshly isolated from the host (p < 0.01). The data obtained during starving the L₃ larvae of A. simplex may be a consequence the role of trehalose as protective compound at stress condition. We suggest that probably in higher temperatures it acts as first a source of energy, and it also might serve to restore the levels of glycogen.     

The enzymes of carbohydrates metabolism from Cysttidicola farionis (Cystidicolidae)

The content of glycogen, glucose and trehalose was measured in larvae and adults of Cystidicola farionis, the parasite isolated from the swim bladder of Osmerus eperlanus from Vistula Lagoon. Activity of glycogen phosphorylase, alpha-amylase, glucoamylase, maltase, trehalase, and trehalose phosphorylase were measured. The highest activity was recorded for alpha-amylase 10.07 +/- 0.97 mu/mg and 7.47 +/- 0.24 mu/mg, next maltase 1.34 +/- 0.63 micromol/mg and 2.06 +/- 1.65 micronol/mg respectively for larvae and adults. The activity of glucoamylase was nearly the same for adults and larvae (about 0.20 micromol/mg). The trehalase activity was higher at adults (0.49 +/- 0.42 micromol/mg) than at larvae (0.18 +/- 0.12 micromol/mg). The activity of glycogen phosphorylase was much higher at larvae (3.58 +/- 1.49 micromol/mg) than at adults parasite (0.10 +/- 0.02 micromol/mg). The trehalose phosphorylase was present in both stages of parasite, but its activity was low. The content of glycogen and glucose was two-times higher in the adults' body than in larvae.     

低温对淡色库蚊海藻糖和海藻糖酶的影响

目的　了解低温环境对淡色库蚊体内海藻糖和海藻糖酶含量的影响。方法　在4 ℃环境中对淡色库蚊四龄初幼虫和雌成蚊分别冷处理0、1、3、6、12、18、24 h和0、1、3、6、12、18、24、36、48、72 h,采用酶联免疫吸附法测定低温处理不同时间淡色库蚊幼虫和成蚊体内海藻糖和海藻糖酶含量。结果　经低温处理后,淡色库蚊幼虫和雌成蚊体内海藻糖和海藻糖酶平均含量均明显增加。幼虫和雌成蚊体内海藻糖变化趋势一致,均在低温处理3 h达到最大值,平均值分别为（2.458 8 ± 0.379 2） mg/g 和（2.825 7 ± 0.211 1） mg /g。海藻糖和海藻糖酶在低温处理前6 h内变化幅度较大,经过一段时间适应后,稳定保持在相对较高水平。结论　低温能快速诱导淡色库蚊体内海藻糖和海藻糖酶产生,海藻糖和海藻糖酶在提高淡色库蚊抗寒性方面可能发挥重要作用。     

低温对淡色库蚊海藻糖和海藻糖酶的影响

目的　了解低温环境对淡色库蚊体内海藻糖和海藻糖酶含量的影响。方法　在4 ℃环境中对淡色库蚊四龄初幼虫和雌成蚊分别冷处理0、1、3、6、12、18、24 h和0、1、3、6、12、18、24、36、48、72 h，采用酶联免疫吸附法测定低温处理不同时间淡色库蚊幼虫和成蚊体内海藻糖和海藻糖酶含量。结果　经低温处理后，淡色库蚊幼虫和雌成蚊体内海藻糖和海藻糖酶平均含量均明显增加。幼虫和雌成蚊体内海藻糖变化趋势一致，均在低温处理3 h达到最大值，平均值分别为（2.458 8 ± 0.379 2） mg/g 和（2.825 7 ± 0.211 1） mg /g。海藻糖和海藻糖酶在低温处理前6 h内变化幅度较大，经过一段时间适应后，稳定保持在相对较高水平。结论　低温能快速诱导淡色库蚊体内海藻糖和海藻糖酶产生，海藻糖和海藻糖酶在提高淡色库蚊抗寒性方面可能发挥重要作用。     

A comparative study of the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya (Caricaceae) on Heligmosomoides bakeri

ObjectiveTo assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya (Caricaceae) on the eggs and first stage larvae (L₁) of Heligmosomoides bakeri.MethodsEggs of this parasite were obtained from experimentally infested mice (Mus musculus) and larvae were from eggs after incubation at 25°C for about 72 hours. The eggs and larvae were exposed to ten different concentrations (0.125, 0.25, 0.375, 0.5, 0.75, 1.0, 1.25, 1.75, 2.25 and 2.75 mg/mL) of both aqueous and ethanolic extracts respectively for 72 hours. Distilled water and 0.05% ethanol used as placebo and negative control, respectively.ResultsPlacebo and negative control group all showed average 92% embryonnation, 98% egg hatching and 2% larval mortality, and did not affect development and larval survival. The extracts inhibited embryonic development, egg hatching and larval survival. In general, the ovicidal and larvicidal activities increased with increasing concentration of different extracts. The aqueous extract was found to be more potent on eggs than on larvae. At 2.75 mg/mL, only 8% of eggs embryonnated and 50% hatched to L₁ vs 57% embryonic development and 79% hatching occurred in the ethanolic extract. However, this later extract was more efficient in preventing larval development producing 96% mortality as against 68% with the aqueous extract.ConclusionsThese results shows the ovicidal and larvicidal properties of aqueous and ethanolic pawpaw seeds extracts.     

The effect of chronic lead acetate trihydrate intoxication in Wistar rats on experimental <Emphasis Type="Italic">Ascaris suum</Emphasis> infestation and immunity

Summary  SPF male Wistar rats were exposed for four months to lead acetate trihydrate present in drinking water (100 mg/l) and subsequently infested with 1000 ± 100 infective A. suum eggs. Metabolic activity of phagocytes and proliferative activity of T-lymphocytes were investigated on Day 4 and 8 after A. suum eggs infestation (Day 130 and 134 of lead acetate trihydrate exposition). The results demonstrated that treatment with lead acetate trihydrate led to increased susceptibility to infestation, manifested by increased average number of A. suum larvae in the lungs of exposed rats compared to unexposed ones. Moreover, migration of A. suum larvae on Day 8 was associated with significant increase in index of metabolic activity of phagocytes in unexposed rats in comparison with controls. In contrast, in rats exposed to the lead and infested by A. suum eggs a non-significant increase in the studied immunological parameters was recorded. Significant differences in immunological parameters were observed between unexposed, infested and infested and exposed groups of rats. In the unexposed group of animals Ascaris suum infestation caused a significant increase in the index of metabolic activity of phagocytes and stimulation index of lymphocytes in comparison with lead exposed rats.     

Content of saccharides and activity of alpha-glycosidases in Galleria mellonella larvae infected with entomopathogenic nematodes Heterorhabditis zealandica

Concentration of glycogen, maltose, and trehalose as well as the activity of hydrolases catabolising them: alpha-amylases, glucoamylase, maltase, and trehalase were studied during a 48 h infection of Galleria mellonella (Lepidoptera) instar larvae infected with infective Heterorhabditis zealandica (20 nematodes/insect). The content of trehalose in the infected insects during the first day of infection was higher (p < 0.05) than in the controls. The concentration of maltose and glycogen were similar in both groups despite the fact that the activity of all examined alpha-glycosidases was generally much higher in the infected insects than in the controls.     

Myocardial oxygen consumption during experimental hypertrophy and congestive heart failure

The purpose of this investigation was to study the effects of experimental myocardial hypertrophy-congestive failure state on myocardial oxygen consumption (MV?O₂). Hypertrophy and heart failure were induced in nine adult cats by surgical banding of the main pulmonary artery to a lumen approximately 10% of normal (2.8 mm circumference clip). Twenty-five to 82 days later nine CHF and 12 control animals were studied, and right ventricular papillary muscles were mounted in a polarographic oxygen electrode muscle bath for simultaneous determination of myocardial mechanics and MV?O₂. Pulmonary arterial banding resulted in average peak systolic right ventricular pressure of 73 ± 7 mmHg and right ventricular/body weight ratio was increased from 0.54 ± 0.08 control to 1.22 ± 0.08 g/kg CHF (P < 0.001). Right ventricular end-diastolic pressure was increased from 1.9 ± 0.2 control to 9.0 ± 1.1 mmHg CHF (P < 0.001) while liver weight/body weight ratio was increased from 27.8 ± 1.1 control to 31.7 ± 1.5 g/kg CHF (P < 0.01). The average force velocity curve was depressed downward and to the left with maximal measured velocity (preload) changing from 1.35 ± 0.07 control to 0.62 ± 0.06 muscle lengths/s (P < 0.001). The extent of shortening and thus the external work performed was significantly depressed in CHF muscles. However, MV?O₂ of afterload contractions of CHF muscles was entirely normal. The length-active tension relationship was significantly depressed with peak developed tension at L_max in CHF muscles of 3.55 ± 0.53 g/mm² (control 6.19 ± 0.55, P < 0.01). Although the rate of tension development of isometric contractions was depressed from 34.1 ± 3.3 control to 14.7 ± 0.19 g/mm²/s CHF (P < 0.001), the MV?O₂ per gram of tension development was paradoxically increased from 0.56 to 1.17 μl/mg/contraction × 10^?3. Resting MV?O² was increased from 2.07 ± 0.19 control to 4.27 ± 0.53 μl/mg/h. The effect of acetylstrophanthidin 2 × 10^?7 g/ml was to increase both the contractile state and MV?O₂ of CHF muscles. These findings demonstrate an inefficiency of conversion of oxygen to tension development in experimental hypertrophy and congestive heart failure.     

Characterization of α,α-trehalase released in the intestinal lumen by the probiotic Saccharomyces boulardii

Objective. Trehalose intolerance due to α,α-trehalase deficiency has scarcely been studied. The purpose of this study was to measure α,α-trehalase activity in intestinal biopsy samples from 200 consecutive patients over a period of 6 months, and to characterize α,α-trehalase released by the probiotic Saccharomyces boulardii (S. boulardii). Material and methods. Enzyme activities were measured in human and rat intestinal mucosal samples using the micromethod of Messer & Dalqvist. α,α-trehalase from S. boulardii was immunoprecipitated and Western blotted using an IgG purified antibody raised against a 23 amino acid peptide of α,α-trehalase of S. cerevisiae. Results. Among 200 patients, most of whom complained of abdominal symptoms and diarrhoea, 18 (9%) had total α,α-trehalase deficiency (0–12 U/g mucosa) and 39 had partial deficiency (3–12 U/g mucosa). Only 4 patients (2%) presented selective α,α-trehalase deficiency with otherwise normal disaccharidases. Expressed per gram of powder, α,α-trehalase from S. boulardii delivered in vitro an activity 175 times higher than that of human trehalase per gram of intestinal mucosa. V_max (22±0.43 µmol) and K_m (5 mM) were close to that of the human enzyme, whereas Western blot revealed a signal of two subunits of 82 kDa. Finally, treatment of rats with S. boulardii resulted in increases in α,α-trehalase activities of 25 to 45% (p<0.01) in endoluminal fluid and intestinal mucosa compared with in controls. Conclusions. Our data suggest that α,α-trehalase deficiency is more common than is believed and that oral administration of S. boulardii could be beneficial in patients with digestive symptoms caused by trehalose intolerance.     

Vasodilatory effect of aerosol histamine during pulmonary vasoconstriction in unanesthetized sheep

The effects of aerosol histamine on pulmonary vascular resistance during pulmonary vasoconstriction were studied in 12 unanesthetized sheep. Sheep were chronically instrumented with Silastic catheters in the pulmonary artery and left atrium, thermodilution Swan-Ganz catheter in the main pulmonary artery for measurement of cardiac output, and tracheostomy for delivery of hypoxic gas and/or aerosol histamine. Seven minutes of isocapnic hypoxia (Fl_O2 = 0.12) caused pulmonary artery pressure (P_PA) to increase from 17.2 ± 0.4 to 27.0 ± 1.0 cm H₂O (X¯ ± SEM, P < 0.05) and pulmonary vascular resistance (PVR) to increase from 3.94 ± 0.33 to 4.71 ± 0.38 cm H₂O · L^?1. min (P < 0.05). When sheep breathed a combination of aerosol histamine (5 mg/ml) and 12% O₂, P_PA rose only to 21.3 ± 1.11 cm H₂O and PVR decreased to 3.51 ± 0.31 cm H₂O · L^?1. min. This was a significantly (P < 0.05) smaller response compared to hypoxia alone. Aerosol histamine alone had no significant effect on P_PA or PVR. Meclofenamate did not restore the histamine-induced loss of hypoxic vasoconstriction. Aerosol histamine significantly blunted the pulmonary vasoconstriction caused by intravenous serotonin (8 μg/kg/min) and intravenous prostaglandin H₂-analog (0.74 μg/kg/min). It was concluded that in the awake sheep aerosol histamine acted as a pulmonary vasodilator only in the presence of pulmonary vasoconstriction. Pediatr Pulmonol 1987; 3:94–100 .     

Changes in the activity and properties of trehalase during early germination of yeast ascospores: Correlation with trehalose breakdown as studied by in vivo13C NMR

The regulation of trehalose breakdown during dormancy and the induction of germination in yeast ascospores was studied both by in vivo high-resolution NMR spectroscopy and in vitro assays of trehalase activity. Natural-abundance ¹³C NMR spectra taken during the induction of germination with glucose and phosphate showed a rapid breakdown of part of the trehalose content. The presence of both glucose and phosphate was important for maximal trehalose breakdown. The ¹³C NMR spectra showed that the externally added glucose and the internal trehalose were metabolized mainly to glycerol and ethanol. Under these conditions of nitrogen deprivation, full germination is not possible and trehalose breakdown stopped after ≈1 hr. At this moment resynthesis of trehalose occurred while glycerol and ethanol production from the exogenous glucose continued. In complex media where full spore germination can occur, trehalose breakdown was more pronounced. Measurements of trehalase activity in spore extracts made after addition of varying amounts of glucose and phosphate to the spores revealed a sudden 10-fold increase in the activity of trehalase, within the first minutes of spore germination. The activation was transient: after reaching a maximum between 5 and 10 min, the activity declined back to low values during the next hours. The increase in trehalase activity was not inhibited by cycloheximide or by anaerobic conditions. The decline in trehalase activity that occurred after the initial activation could be correlated with the extent of trehalose breakdown as measured by ¹³C NMR. In addition to the increase in trehalase activity, differences in the control properties were found between the enzymes from dormant and germinating spores. Trehalase from dormant spores was strongly inhibited by ATP at a concentration of ≈0.5 mM, which corresponds with the ATP concentration found in dormant spores. On the other hand, trehalase from germinating spores was not inhibited by ATP up to the much higher ATP concentrations that are found in germinating spores. It is suggested that the low activity and the stringent ATP feedback inhibition of trehalase from dormant spores are responsible for the very slow mobilization of the huge amount of trehalose in dormant spores. Therefore, dormancy seems to be caused primarily by extreme curtailment of the energy production within the spore at one selective and primary point. The switch towards high activity and low ATP inhibition upon induction of germination is suggested to be responsible for the breaking of dormancy and for the rapid breakdown of trehalose that occurs during the initial phase of germination.     

Troglitazone reduces hyperglycaemia and selectively acute-phase serum proteins in patients with Type II diabetes

Aims/hypothesis. Inflammation could play a part in insulin resistance. Thiazolidinediones, new antidiabetic drugs, possess anti-inflammatory effects in vitro. We investigated if acute-phase serum proteins are increased in patients with Type II (non-insulin-dependent) diabetes mellitus who had been treated with insulin and whether troglitazone has anti-inflammatory effects in vivo.¶Methods. A total of 27 patients (age 63.0 ± 1.7 years, HbA_{1 c} 8.8 ± 0.3 %, BMI 32.7 ± 0.8 kg/m², duration 15.2 ± 1.4 years, insulin dose 73.3 ± 7.0 U/day) participated in the study. The patients received daily either 400 mg troglitazone or placebo for 16 weeks. Blood samples were taken at baseline, at the end of therapy and after a follow-up time of 23 ± 4 days.¶Results. The concentrations of serum amyloid A (6.2 ± 1.1 mg/l) and C-reactive protein (6.1 ± 1.1 mg/l) were increased (p < 0.001) and complement protein C3 (1.69 ± 0.05 g/l) was also above the reference range for healthy subjects. Placebo treatment had no effect on glucose or inflammation, whereas troglitazone reduced fasting glucose (from 10.4 ± 0.6 mmol/l to 8.1 ± 0.5 mmol/l, p < 0.01), HbA_{1 c} (from 8.7 ± 0.3 % to 7.5 ± 0.3 %, p < 0.01), insulin requirements (from 75 ± 10 U/day to 63 ± 10 U/day, p < 0.05), serum amyloid A (from 6.3 ± 1.5 mg/l to 4.0 ± 1.3 mg/l, p = 0.001), α-1-acid glycoprotein (from 906 ± 51 mg/l to 729 ± 52 mg/l, p = 0.001) and C3 (from 1.72 ± 0.07 g/l to 1.66 ± 0.06 g/l, p < 0.05) but not α-1-antitrypsin, ceruloplasmin, C-reactive protein or haptoglobin significantly. Concentrations of glucose and acute-phase reactants had returned to those before treatment at the follow-up visit.¶Conclusion/interpretation. In Type II diabetic patients serum amyloid A and complement protein C3 are raised. Troglitazone exerts a selective reversible action on some acute-phase proteins and C3 but not on others in conjunction with the improvement in glucose metabolism. [Diabetologia (1999) 42: 1433–1438]     

Content of glycogen and trehalose and activity of alpha-amylase and trehalase in Galleria mellonella larvae infected with entomopathogenic nematodes Steinernema affinis and S. feltiae

INTRODUCTION: The influence of infection with two species of entomopathogenic nematodes of Steinernematidae family on metabolism of glycogen and trehalose of the host was studied. MATERIAL AND METHODS: Last instar larvae (L7) of Galleria mellonella were experimentally infected with Steinernema affinis and S. feltiae. At 6, 12, 18 and 24 h after infection concentrations of trehalose and glycogen as well as activity of trehalase and alpha-amylase were determined. RESULTS: The content of glycogen was lower in insects infected with S. feltiae than in the controls and animals infected with S. affinis. The content of trehalose was higher in insects from both infected groups than in the controls. Its concentration was slightly higher in larvae infected with S. affinis than in those infected with S. feltiae. The activity of alpha-amylase after infection with S. affinis was low. It was significantly higher in insects infected with S. feltiae. In animals of both infected groups, following a significant reduction at 6 h, the activity of trehalase remained at a similar level, higher than in the controls. In the paper the effects of infection with (i) different species of entomopathogenic nematodes and (ii) the importance of the developmental stage of the insect-host for changes in its metabolism of glycogen and trehalose were discussed.     

Vasopressor and Vasodepressor Hormone-Systems in Adolescent Hypertension

We investigated the activity of the renin-angiotensin-aldosterone-system, the secretion of catecholamines and the kallikrein-kinin-system in 126 adolescents randomly selected from a large study of 1342 young people examined in an epidemiological survey conducted in Cologne in 1975, 1976 and 1980. 73 of them with arterial blood pressures below 145/90 mm Hg were called “normotensives” (systolic blood pressure 127.2 ± 1.0 mm Hg, diastolic bp 79.7 ± 0.8 mm Hg). They were compared with 53 “hypertensives” (systolic blood pressure 147.2 ± 1.6 mm Hg, diastolic bp 93.7 ± 1.1 mm Hg).

Urinary catecholamines were significantly higher in the hypertensives (155.0 ± 13.3 μg/d) compared to the normotensives (100.7 ± 5.3 μg/d) (p < 0.001) whereas plasma levels of adrenaline and noradrenaline were similar. Serum aldosterone levels and plasmarenin-concentrations were not different between the two groups. Angiotensin-converting-enzyme-activity was slightly higher in the hypertensive group (107.1 ± 3.5 U/1 versus 98.0 ± 2.6 U/1, p < 0.001). Urinary kallikrein excretion was found to be modestly lower in hypertensives compared to normotensives (0.40 ± 0.05 versus 0.55 ± 0.06 mU/mg creatinine). Urinary excretion of sodium and potassium, blood levels of glucose, uric acid, cholesterol and triglycerides were similar in both groups. The results of the present study suggest an increased sympathetic activity in the early stage of hypertension in adolescents.     

Agonist-independent modulation of L-type Ca currents by basal Gs protein activities in single guinea pig ventricular myocytes

The modulation of L-type Ca²⁺ currents (I _Ca,L) by the basal activities of G proteins was studied in adult guinea pig ventricular myocytes by whole-cell patch-clamp techniques. With intrapipette guanosine triphosphate (GTP) (100 μM), a specific inhibition of G_i proteins by pertussis toxin (PTX) produced an increase in the basal density of I _Ca,L (from 11.0 ± 0.8, n = 13, to 25.0 ± 2.0 pA/pF, n = 11, at 0 mV test potential). In addition, PTX shifted the forskolin (Fsk) concentration–I _Ca,L response relation significantly leftward (EC₅₀ = 63.7 ± 12.5 vs 625 ± 75 nM). With intrapipette guanosine diphosphate (GDP)βS (1 mM), the Fsk–I _Ca,L relation was also shifted leftward (EC₅₀ = 197 ± 18.3 vs 781 ± 82.5 nM). However, chronic GDPβS dialysis accelerated the rundown of I _Ca,L significantly, suggesting a potential contribution of G_s proteins in maintaining basal I _Ca,L. In contrast, intra-pipette GTPγS (100 μM) produced a transient rise in I_Ca,L from 11.0 ± 3.0 to 22.8 ± 7.0 pA/pF (in 3.4 min after whole-cell formation at 0 mV, n = 9), presumably through the activation of G_s proteins. It was followed by a gradual decline in I _Ca,L (to 15.5 ± 3.5 pA/pF), which was still enhanced by Fsk (EC₅₀ = 1450 ± 98 nM), indicating that the current decay was not solely due to rundown but to activation of G_i proteins. G_s, in addition to G_i proteins, show sufficient basal activity to modulate I _Ca,L in an agonist-independent manner. Received: October 19, 2000 / Accepted: February 24, 2001     

Prostaglandins in colonic anastomotic healing

In this study we report the effects of flurbiprofen and prostaglandin E₂ on anastomotic tensile strength, collagen synthesis, and collagenolytic activity which are in a particularly fine balance in colonic healing. Colonic anastomoses were fashioned in 150 Sprague—Dawley rats which were allocated to receive either 20 mcg prostaglandin E₂ in 1 ml saline, 1 ml saline alone (control) intraperitoneally for three days postoperatively, or oral 2.5 mg/kg flurbiprofen daily. Anastomotic bursting pressures, collagen content and collagenolytic activity were measured at three, six, and ten days. It was found that prostaglandin E₂-treated animals had significantly weaker anastomoses at three days (102±6.1 mm Hg; m±SEM) compared with the control (126±7.3;P<0.02) or flurbiprofen group (128±4.6;P<0.01) with no differences at six and ten days. Collagen levels were higher in flurbiprofen-treated rats at three days (9.7±0.2 μg hydroxyproline/mg tissue) compared with the control (8.1±0.4 μg/mg;P 0.01) or prostaglandin E₂ group (7.2±0.5 μg/mg;P 0.001). These differences were unchanged at six days but were not statistically different at ten days. Collagenolytic activity showed no differences in the three groups during the study. It is concluded that flurbiprofen enhances colonic healing with improved collagen synthesis without affecting collagenolytic activity.     

Persistent increased lung response to methacholine after normobaric hyperoxia in rabbits

This study was performed to determine the occurrence and time course of airway hyperreactivity following exposure to normobaric hyperoxia. Twenty-six rabbits were studied. Twelve served as control (group 1), and 14 were exposed to normobaric hyperoxia (Fi_O2 ≥ 95%) for 48 h: 9 rabbits (group 2) were studied after 1 day of recovery in room air and 5 (group 3) after 7 days. The rabbits were anesthetized, curarized and artificially ventilated. Respiratory resistance (Rrs) and elastance (Ers) and their respective changes induced by cumulative doses of aerosolized methacholine were assessed by the multiple linear regression analysis of airway pressure, tidal flow and volume. Weight-specific Rrs and Ers were significantly higher in group 2 (respectively, 87.7 ± 6.5 cmH₂O·L⁻¹·sec·kg and 1100.2 ± 87.1 cmH₂O·L⁻¹·kg, mean ± SEM) than in group 1 (respectively, 65.2 ± 3.2 cmH₂O·L⁻¹·sec·kg and 904.4 ± 49.7 cmH₂O·L⁻¹·kg (P < 0.05)), but were not different from group 3 (79.4 ± 7.9 cmH₂O·L⁻¹·sec·kg and 952.3 ± 125.0 cmH₂O·L⁻¹·kg, respectively). The dose of methacholine required to increase Rrs by 50% (PD_Rrs50) was significantly lower in both treated groups: 0.37 ± 0.11 mg in group 2 and 0.51 ± 0.19 mg in group 3 vs 2.07 ± 0.51 mg in group 1 (P < 0.05)). PD_Ers50 was significantly lower in group 2 (0.45 ± 0.15 mg) and 3 (0.75 ± 0.43 mg) compared with controls (1.11 ± 0.26 mg (P < 0.05)). These results show that hyperoxia induces an increase in Rrs and Ers, and airway hyperreactivity in the rabbit. The latter is prolonged beyond the immediate post-exposure period.     

Bioactivity of sea grass against the malarial fever mosquito Culex quinquefasciatus

ObjectiveTo identify the larvicidal activity of the seagrass extracts against Culex quinquefasciatus (Cx. quinquefasciatus)MethodsSeagrass extracts, Halodule pinifolia (H. pinifolia), Cymodocea serrulata (C. serrulata) and Thalasia testudinum (T. testudinum) were dissolved in dimethylsulfoxide to prepare a graded series of concentration. Batches of 25 early 4th instars larvae of Cx. quinquefasciatus were transferred to 250 mL enamel bowl containing 199 mL of distilled water and 1 mL of plant extracts (0.01 mg−0.1 mg). After 24 h the mortality rate was identified with the formulae [(% of test mortality − % of control mortality)/(100 − % of control mortality)]×100. Each experiment was conducted with three replicates and a concurrent control group. A control group consisted of 1 mL of dimethylsulfoxide and 199 mL of distilled water only.ResultsThe root extract of H. pinifolia showed maximum larvicidal activity with minimum concentration of extract of LC₅₀ value of (0.614±0.006) μg/mL with lower confidence limit-upper confidence limit value of (0.052–0.072) and LC₉₀ value of 0.9120 μg/mL followed by leaf extract of C. serrulata LC₅₀ value of (0.074±0.008) μg/mL and LC₉₀ value of 0.1487 μg/mL. T. testudinum leaf extract showed LC₅₀ value of (0.082±0.006) μg/mL. The regression equation of root and leaf extract of H. pinifolia for 4 th instar larvae of Cx. quinquefasciatus were Y=5.229+1.36x (R²=0.993) and Y=2.369+1.21x (R²=0.878) respectively and analysis of variation was significant at P<0.05 level. The result of the preliminary phytochemical constituents showed the presence of saponin, steroids, terpenoid, phenols, protein and sugars.ConclusionsFrom the present study the ethanolic extracts of seagrass of H. pinifolia possess lead compound for development of larvicidal activity.     

Intravenous Alfacalcidol Once Versus Twice or Thrice Weekly in Hemodialysis Patients

Secondary hyperparathyroidism remains a serious problem in hemodialysis patients. The use of vitamin D analogs still constitutes a basis for its treatment. This study was carried out to evaluate the efficacy of intravenous administration of alfacalcidol once versus twice or thrice weekly in hemodialysis patients with secondary hyperparathyroidism. Twenty‐nine end‐stage renal disease patients maintained on hemodialysis for more than one year were included in this prospective study after signing the consent. These patients with secondary hyperparathyroidism had been on intravenous alfacalcidol twice or thrice per week and were followed up to 4 months (stage 1). Then they were shifted to intravenous alfacalcidol once weekly starting with the last total weekly intravenous dose for another 4 months (stage 2). The dose of alfacalcidol was adjusted according to intact parathyroid hormone, serum calcium and phosphorus levels, and calcium‐phosphorus product. Intact parathyroid hormone, calcium, phosphorus, calcium‐phosphorus product were measured monthly. Parathyroid ultrasound was done as a baseline and then repeated at the end of stage 1 and stage 2. The intact parathyroid hormone was reduced from 49.72 ± 2.72 pmol/L (mean ± standard error of the mean [SEM] during stage 1 to 42.13 ± 2.15 pmol/L during stage 2 (P = 0.005). Dose of alfacalcidol was reduced from 18.80 ± 1.15 µg/month (mean ± SEM) in stage 1 to 15.18 ± 1.27 µg/month in stage 2 (P = 0.008), and consequently the cost of alfacalcidol was reduced from 21.05 ± 1.25 US$/month (mean ± SEM) during stage 1 to 16.87 ± 1.40 US$/month during stage 2 (P = 0.008). Although the phosphorus level increased from 1.56 ± 0.36 mmol/L (mean ± SD) in stage 1 to 1.70 ± 0.46 mmol/ L in stage 2 (P = 0.003), and calcium‐phosphorus product increased from 3.48 ± 0.82 mmol²/L² (mean ± SD) in stage 1 to 3.76 ± 1.00 mmol²/L² in stage 2 (P = 0.017), they remained in the target levels recommended by the Kidney Disease Outcomes Quality Initiative guidelines. No serious effects were observed during stage 1 and stage 2, respectively. Intravenous alfacalcidol once weekly is effective, safe and less costly in suppressing intact parathyroid hormone compared to twice or thrice weekly administration in chronic hemodialysis patients.     

Evaluation of phytochemical and antioxidant activities of the different fractions of Hybanthus enneaspermus (Linn.) F. Muell. (Violaceae)

ObjectiveTo investigate the naturally occurring antioxidant for the first time from the different solvent fractions of Hybanthus enneaspermus (H. enneaspermus) Linn F. Muell. family (Violaceae).MethodsDifferent fractions of H. enneaspermus were tested for total phenolic content, and in vitro antioxidant activity was measured by total antioxidant assay, DPPH assay, reducing power, nitric oxide (NO), hydrogen peroxide (H₂O₂) scavenging assays.ResultsThe ethyl acetate (EA) fraction was found to have high levels of phenolic content [(212.15±0.79) mg GAE/g]. The EA fraction exhibited higher total antioxidant capacity, higher percentage of DPPH radical scavenging activity [(127.07±2.29) μg/mL], nitric oxide [(245.16±1.44) μg/mL], hydrogen peroxide [(227.38±7.18) μg/mL], deoxyribose [(270.61±8.72) μg/mL] and higher reducing power. There was a significant correlation between total phenolic content and total antioxidant activity (r²=0.972).ConclusionsThese results reveal that EA fraction of H. enneaspermus has strong antioxidant potential compared with other fractions. Our further study has been extended to the isolation of the possible compound that is responsible for having antioxidant property.