The effect of poly-L-lysine, amiloride and methyl-L-lysine on gill ion transport and permeability in the rainbow trout

The action of poly-L-lysine (PLL) on Na and Cl transport across freshwater fish gills was studied. Low concentration (10-6M) were added to the external medium for brief periods (1--5 min), then removed. During the next 20 min there was a rapid net loss of Na (117+/17 muEquiv[100 g]-1hr-1) and Cl (129+/17 muEquiv[100 g]-1hr-1). Both values are an order of magnitude larger than unidirectional effluxes in control fish. The efflux of both ions decreased to control values within 60 min after application and removal of PLL. In contrast, unidirectional influxes (JCl in and JNa in) were inhibited by about 40+ and showed no sign of returning to the original rates for 3 hr. Thus, PLL has two independent actions, causing a large increase in gill permeability which is reversible within an hour and apartial inhibition of influx which showed no sign of reversing for 2--3 hr. When PLL was applied for a longer period (60 min, the results were qualitatively similar but the permeability change was larger and persisted longer. These effects were compared with those of the small organic amines, amiloride and methyl-L-lysine. The latter inhibited JNa in, but there was not other similarity to PLL. Neither affected sodium efflux, not did they have any effect on Cl movements, in or out, across the gill. Inhibition of JNa in, was rapidly and completely reversible, and amiloride was shown to act by competing with Na for an entry site.     

Effect of gonadal steroid hormones on plasma growth hormone concentrations in sexually immature rainbow trout, Oncorhynchus mykiss

Single-cell assays of cell migration, while yielding dynamic measurements of cell position and morphology, are predominantly limited by the time required for data collection and analysis. Computer-aided fluorescence time-lapse videomicroscopy (CAFTiV) was developed in order to facilitate the tracking and rapid examination of large numbers of motile cells. The system combines time-lapse videomicroscopy with epifluorescence capability, which allows full automation of image capture, sorting, and analysis due to the low background in the fluorescence images. Utilizing the CAFTiV system, data analysis time was reduced from over 125 h to less than 1 labor minute. In addition, fluorescence imaging permits cell tracking in small-volume chambers (<100 microL), which is useful should the addition of expensive reagents be required. It is anticipated that the ability to characterize both biochemical and biophysical properties responsible for cell movement will be enhanced by this methodology.     

Metformin therapy is associated with a decrease in plasma plasminogen activator inhibitor-1, lipoprotein(a), and immunoreactive insulin levels in patients with the polycystic ovary syndrome

Sixteen nondiabetic women with polycystic ovary syndrome (PCOS) aged 18 to 33 years were studied before and after 8 weeks on metformin (1.5 g/d) therapy to assess whether reducing hyperinsulinemia would reduce the levels of the major inhibitor of fibrinolysis, antigenic plasminogen activator inhibitor type 1 (PAI-1). Compared with six normal control women, PCOS women had a higher body mass index (BMI), waist to hip ratio, fasting insulin (Izero), insulin area under the curve during oral glucose tolerance testing (IA), glucose area under the curve during oral glucose tolerance testing (GA), IA/GA ratio, PAI-1, luteinizing hormone (LH) and ratio of LH to follicle-stimulating hormone (FSH), and free testosterone, and lower high-density lipoprotein (HDL) cholesterol (all P < .025). On metformin, BMI decreased 1.3% (P = .04), Izero 43% (P = .002), IA 31% (P = .03), GA 11% (P = .02), PAI-1 16% (P = .01), lipoprotein(a) [Lp(a)] 42% (P = .004), free testosterone 46% (P = .0006), LH 44% (P = .004), and the LH/FSH ratio 41% (P = .0001). On metformin, absolute and percent reductions in Izero correlated with absolute and percent reductions in PAI-1 (r = .60, P = .015 and r = .64, P = .008). On metformin, by stepwise multiple regression, the absolute reduction in Izero was a significant determinant of the absolute reduction in PAI-1 (partial R2 = 35%, P = .02), and the percent reduction in Izero was a significant determinant of the percent reduction in PAI-1 (partial R2 = 52%, P = .003). Metformin decreases Izero in hyperinsulinemic PCOS patients, reverses the hyperinsulinemia-driven endocrinopathy, decreases PAI-1, and decreases Lp(a), and should thus reduce the increased risk of atherothrombosis in PCOS.     

Regulation of melatonin synthesis in rainbow trout (Oncorhyncus mykiss) pineal organs: effects of calcium depletion and calcium channel drugs

In a double-blind, randomized trial, 40 patients undergoing open anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft were randomly allocated to two groups: group A (n = 20) received an intra-articular instillation of 20 mL bupivacaine (0.25%) and a local infiltration of 20 mL bupivacaine (0.5%) 15 minutes before surgery. Group B (n = 20) received an injection of saline solution in the same manner. Patient-controlled on-demand analgesia (PCA) with intravenous piritramid was used for postoperative pain control. A significant decrease in pain scores on a visual analog scale (VAS scale, 0 to 10) was found in the bupivacaine group (group A) at bedrest on the day of surgery only (pain score, 5.5 v 7.3 (scale, 0 to 10), P < .05). At all other times, no significant differences were found. The overall supplemental opioid requirements were not different between the study groups (63.9 v 62.6 mg piritramid/72 hours). A long-lasting, clinically relevant, pain-reducing effect with infiltration of bupivacaine before surgery could not be shown with this study.     

Enkephalin hydrolysis in plasma is highly correlated with escape performance in the rat.

A very high correlation was found in rats between latency to escape on the first trial of an active avoidance task and the rate at which [leu]enkephalin is hydrolyzed in plasma. In addition, the rate of [leu]enkephalin hydrolysis is significantly altered following the first training trial. The results suggest that a regulatory enzyme system exists for [leu]enkephalin in plasma and that this system may be important for modulating behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regulation of the intracellular concentration of free calcium ions in pinealocytes of the rainbow trout and the rat

Together with cAMP, calcium ions play an important role in the regulation of melatonin synthesis in the pineal organ of all vertebrate species, irrespective of the conspicuous phylogenetic transformation of the melatonin-producing cell, the pinealocyte. Here we address the question how the intracellular concentration of free calcium ions [Ca2+]i is regulated in directly light-sensitive trout pinealocytes and in rat pinealocytes which have lost the direct light sensitivity and respond to norepinephrine. Isolated pinealocytes identified by the S-antigen immunoreaction were investigated by means of the fura-2 technique, image analysis and patch clamp recordings. Approximately 30% of the trout pinealocytes exhibited spontaneous [Ca2+]i oscillations that were not affected by light or dark adaptation of the cells. Removal of extracellular Ca2+ or application of 10 microM nifedipine caused a reversible breakdown of the [Ca2+]i oscillations. Treatments with 60 mM KCl and nifedipine suggest that voltage-gated L-type calcium channels play a major role in the regulation of [Ca2+]i in both oscillating and nonoscillating trout pinealocytes. Experiments with thapsigargin (2 microM) revealed the presence of intracellular calcium stores in 80% of the trout pinealocytes, but their role in the regulation of [Ca2+]i remains elusive. Norepinephrine had no apparent effect on [Ca2+]i in any trout pinealocyte. In rat pinealocytes, [Ca2+]i did not show spontaneous oscillations. Norepinephrine evoked a dramatic biphasic rise in [Ca2+]i in more than 95% of the cells via stimulation of alpha1-adrenergic receptors. The response reflects a combination of calcium mobilization from intracellular, thapsigargin-sensitive calcium stores and an increased calcium influx. Voltage-gated calcium channels of the L-type are present in the rat pinealocyte membrane, but they are not involved in the norepinephrine-induced calcium response. These channels, however, mediate the increase in calcium influx which is observed in virtually all rat pinealocytes upon stimulation with acetylcholine or nicotine. The results show that the mechanisms which regulate [Ca2+]i in pinealocytes are complex and differ considerably between poikilothermic and mammalian species.     

Occurrence of Loma cf. salmonae in brook, brown and rainbow trout from Buford trout hatchery, Georgia, USA

We retrospectively analysed the long-term treatment results (median 8 years) of 31 patients with macroprolactinoma. 17 patients were treated by pituitary surgery (group 1) followed by long-term dopamine agonist therapy whereas 14 patients received long-term dopamine agonist therapy alone (group 2). 2 patients of group 1 and 1 patient of group 2 had external pituitary irradiation because of progressive disease. The two groups were comparable with respect to age, gender and initial prolactin (PRL) levels. At the end of the observation period dopamine agonist dosage could be reduced by 50% in group 1 and by 39.3% in group 2. Pituitary function did not change substantially during therapy. Complete remissions (no visible tumour in CT or MRI, normal PRL levels under current dopamine agonist medication) were achieved in 23.5% of group 1 vs. 21.4% of group 2, partial remissions (reduction of PRL and tumour size) in 35.3% vs. 64.3%, stable disease in 23.5% vs. 7.1% and progressive disease in 17.7% vs. 7.1% (differences not significant). Visual field defects showed 28.4% remissions (complete and partial) in group 1 versus 50% in group 2. Dopamine agonist therapy could be stopped definitively in only 1 patient of group 2 with an invasive macroprolactinoma. Initial surgical reduction of tumour load followed by medical therapy does not seem to guarantee a better long-term outcome than dopamine agonist therapy alone if the patient responds to and tolerates dopamine agonist therapy. Surgery should be reserved for non-responders, drug-intolerant or non-compliant patients, and for those with acute severe neurological compromise.     

Neurite outgrowth stimulated by L1 requires calcium influx into neurons but is not associated with changes in steady state levels of calcium in growth cones

L1, NCAM and N-cadherin are cell adhesion molecules (CAMs), present on neuronal growth cones, which promote cell-contact dependent axonal growth by activating a second messenger pathway in neurons that requires calcium influx through L- and N-type calcium channels. In the present study we show that two of these CAMs, (L1 and N-cadherin) can stimulate neurite regeneration from axotomised adult dorsal root ganglion (DRG) neurons cultured in vitro and that this response can be fully inhibited by agents that block or negate the effect of calcium influx into the neurons. However although the response required calcium influx into neurons, it was not associated with an increase in the steady state levels of calcium in neuronal growth cones. These results suggest that small localised changes, or increases in the rate of calcium cycling, in growth cones and/or filopodia, are more important for regulating axonal growth than changes in the steady-state level of calcium.     

Serum calcium, magnesium and inorganic phosphorous levels during various phases of menstrual cycle

BACKGROUND/AIM: Hepatic tumors with elements of both hepatocellular and cholangiocellular carcinoma are occasionally encountered; however, the independent and simultaneous occurrence of different epithelial malignant tumors in different lobes is rare. This is a case report of resected double cancer in different lobes of the liver. MATERIALS AND METHODS: A 73 year old Japanese man, with hepatic mass and a history of peritonitis and hepatitis, underwent laparotomy and hepatic resection of the posterior inferior and the left lateral segment, and cholecystectomy for cholecystlithiasis with left-sided gallbladder at our hospital in 1991. RESULTS: The tumor, located in the posterior inferior segment, a yellow-white, round, highly circumscribed mass with a thick capsule, was about 9.0 by 8.0 cm in size. The other tumor located in the left lateral segment, grayish-white on the cut section, was approximately 5.0 by 4.0 cm. CONCLUSION: In our case, it is unlikely the tumor in the right lobe metastasized to the left lobe and transformed into a different type. The two tumors showed clearly different microscopic features. Improved imaging will increase the frequency and number of double cancer diagnosis. This additional data may shed light on the pathogenesis and etiology of double cancer.     

Thyroid dysfunction is not associated with alterations in serum leptin levels

To determine if serum leptin levels are affected by thyroid dysfunction, we measured its concentration in serum samples from 25 euthyroid controls and 25 subjects each with hypothyroidism and thyrotoxicosis collected over a 3-month period. Mean leptin levels in the euthyroid (24.1 +/- 8.3 microg/L), hypothyroid (22.7 +/- 7.0 microg/L) and thyrotoxic (23.3 +/- 4.3 microg/L) groups were not significantly different. Data were available to express leptin in terms of body mass index (BMI) in 11 euthyroid, and 6 untreated hypothyroid and thyrotoxic individuals. There was a significant positive correlation between BMI and leptin level (r = 0.60, p = .0002) for this subgroup, irrespective of their thyroid status. These data suggest that leptin levels are not affected by thyroid dysfunction.     

Characteristics of two salmonid repetitive DNA families in rainbow trout, Oncorhynchus mykiss

DNA sequence and genomic location of two repetitive DNA families in rainbow trout (Oncorhynchus mykiss) were investigated to develop molecular markers for chromosome identification. DNA fragments with sequences similar to the tandem and interspersed elements described in other salmonids were isolated. One clone showed differential hybridization to 12 pairs of chromosomes and should be a useful marker for physical mapping.     

Toxicological and kinetic study of musk xylene in rainbow trout, Oncorhynchus mykiss

In a prospective study of 6301 surgical patients in a university hospital, we examined the strength of association between ASA physical status classification and perioperative risk factors, and postoperative outcome, using both univariate analysis and calculation of the odds ratio of the risk of developing a postoperative complication by means of a logistic regression model. Univariate analysis showed a significant correlation (P < 0.05) between ASA class and perioperative variables (intraoperative blood loss, duration of postoperative ventilation and duration of intensive care stay), postoperative complications and mortality rate. Univariate analysis of individual preoperative risk factors demonstrated their importance in the development of postoperative complications in the related organ systems. Estimating the increased risk odds ratio for single variables, we found that the risk of complication was influenced mainly by ASA class IV (risk odds ratio = 4.2) and ASA class III (risk odds ratio = 2.2). We conclude that ASA physical status classification was a predictor of postoperative outcome.     

Reproductive success of female rainbow trout (Oncorhynchus mykiss) in response to graded dietary ascorbyl monophosphate levels

Ascorbic acid is an essential nutrient in rainbow trout diets and has been shown to play an important role in fish reproduction. Recommended dietary levels are based on immature fish, and the specific requirements for brood stock are unknown. To establish the optimum dietary level for mature rainbow trout, six graded levels of ascorbyl-2-monophosphate were fed to groups of female fish over a period of 10 mo until spawning. Increasing dietary levels of ascorbyl monophosphate resulted in significantly increased ascorbic acid concentrations in liver, kidney, ovaries, and ovulated eggs. Liver and egg concentrations were saturable at 109.3 and 266.6 micrograms ascorbic acid/g tissue, respectively. Tissue saturation levels of 83.7% and 91.2%, respectively, were reached at the highest dietary level (870 mg ascorbyl monophosphate/kg diet) tested. Both fecundity and embryo survival increased significantly with dietary ascorbyl monophosphate levels. The results indicated that the present National Research Council recommended dietary level of 50 mg ascorbic acid/kg diet for rainbow trout is inadequate for brood stock fish. An amount 8 times higher is necessary to optimize tissue ascorbic acid levels and achieve maximum reproductive success.     

Leptin levels do not change acutely with food administration in normal or obese subjects, but are negatively correlated with pituitary-adrenal activity

Modern liver surgery is based upon deep knowledge of the surgical anatomy of the liver and improvements with ultrasounds imaging techniques have provided multidimensional interpretations of the liver anatomy intraoperatively. The technical advances with real-time scanning combined with the pioneering efforts of the Japanese liver surgeons have permitted the dynamic adaptation of the functional liver anatomy to the real anatomy, thus intimately aiding in segment oriented anatomical resection. Intraoperative ultrasound afford several advantages such as viewing the internal anatomy in direct relationship to the surface landmarks under the probe, enabling higher frequencies resulting in greater image resolution. The utilization of intraoperative ultrasound can modify the tactics involved with resection of both primary and metastatic liver tumours. The routine use of intraoperative ultrasound is strongly advocated since more complex procedures can be performed safely since the surgeon proceeds with complete knowledge of the real liver anatomy when deciding the feasibility and extent of liver resection.     

The induction of c-Fos in the NTS after taste aversion learning is not correlated with measures of conditioned fear.

The induction of c-Fos-like immunoreactivity (c-FLI) in the nucleus of the solitary tract (NTS) has been shown to be correlated with behavioral expression of a conditioned taste aversion (CTA). However, because this cellular response is also dependent on an intact amygdala, it may represent the activation of a stress-related autonomic response. The present experiments addressed this possibility by evaluating the correlation between c-FLI in the intermediate division of the NTS (iNTS) and 2 measures of conditioned fear: freezing and changes in mean arterial pressure (MAP) and heart rate (HR). Exposure to the taste conditioned stimulus (CS) resulted in a marked induction of c-FLI in the iNTS, whereas exposure to a fear CS did not. Further, exposure to a taste CS did not selectively lead to increases in MAP or HR. Results suggest that induction of c-FLI in the iNTS may reflect the activation of a cell population whose function is unique to the CTA paradigm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cytopathogenic effect in cardiac myocytes but not in cardiac fibroblasts is correlated with reovirus-induced acute myocarditis

A panel of reovirus strains was used to compare myocarditic potential with induction of cytopathic effect in primary cardiac myocyte and cardiac fibroblast cultures. The results suggest that viral cytopathogenicity in cardiac myocytes, but not in cardiac fibroblasts, is a determinant of reoviral myocarditis.     

Stimulatory effect of regucalcin on ATP-dependent calcium transport in rat liver plasma membranes

The effect of regucalcin, a calcium-binding protein isolated from rat liver cytoplasm, on ATP-dependent calcium transport in the plasma membrane vesicles of rat liver was investigated. (Ca(2+)- Mg2+)-ATPase activity in the liver plasma membranes was significantly increased by the presence of regucalcin (0.1-0.5 microM) in the enzyme reaction mixture. This increase was completely inhibited by the presence of sulfhydryl group modifying reagent Nethylmaleimide (5.0 mM NEM) or digitonin (0.04%), which can solubilize the membranous lipids. When ATP-dependent calcium uptake by liver plasma membrane vesicles was measured by using 45CaCl2, the presence of regucalcin (0.1-0.5 microM) in the reaction mixture caused a significant increase in the 45Ca2+ uptake. This increase was about 2-fold with 0.5 microM regucalcin addition. An appreciable increase was seen by 5 min incubation with regucalcin addition. The regucalcin-enhanced ATP-dependent 45Ca2+ uptake by the plasma membrane vesicles was completely inhibited by the presence of NEM (5.0 mM) or digitonin (0.04%). These results demonstrate that regucalcin activates (Ca(2+)-Mg2+)-ATPase in the liver plasma membranes and that it can stimulate ATP-dependent calcium transport across the plasma membranes.     

Ca2+ activated myosin-ATPase in cardiac myofibrils of rainbow trout, freshwater turtle, and rat

The effects of natural variation in the number of copies of the growth hormone (GH) gene on growth parameters, plasma GH profiles, and the response to GHRH challenge were compared in Coopworth ram lambs from selection lines differing in body composition and GH levels. Different genotypes at the GH locus carried two, three, or four copies of the GH gene and GH secretion was studied under ad libitum feeding conditions and in the fasted state. There were no significant effects of GH genotype on any parameters of growth or body composition. Basal serum GH concentration, GH pulse frequency, and GH pulse amplitude differed significantly with selection line and fasting, but did not differ significantly between the GH genotypes. Significant differences of subtle nature were found between the GH genotypes in their responsiveness to GHRH. For the ad libitum-fed Lean selection line animals, the first GHRH challenge resulted in a higher mean maximum response for GH1/GH1 than GH2/GH2 (P < 0.05). Between the first and the second challenges there was a decrease in maximum response for the GH1/GH1 genotype and an increase for the GH2/GH2 genotype (P < 0.05 for GH genotype main effect). The differences between GH genotypes in response to GHRH challenge suggest that polymorphism in the number of GH gene copies in sheep may have physiological implications for the function of the GH axis, which may be manifested in growing lambs only under specific genotype-environment combinations.