Investigation of trophic level and niche partitioning of 7 cetacean species by stable isotopes, and cadmium and arsenic tissue concentrations in the western Pacific Ocean.

A total of 24 stranded or bycatch cetaceans, including Balaenoptera omurai, Lagenodelphis hosei, Kogia sima, Stenella attenuata, Grampus griseus, Neophocaena phocaenoides, and Sousa chinensis, were collected from 2001 to 2011 in Taiwan. Using the muscular δ(13)C and δ(15)N data, three ecological groups were identified as the oceanic baleen whale, the neritic, and the coastal toothed whale groups, coinciding with their taxonomy, feeding habits and geographical distribution. A horizontal inshore to offshore distribution was found for the sympatric neritic toothed dolphins, G. griseus, K. sima, S. attenuata, and L. hosei in the outermost offshore waters, accompanying their growth. For the first time we identify Taiwan's Chinese white dolphin, S. chinensis, as an exclusive fish eater. Cd and As bioaccumulated in the G. griseus, L. hosei and S. attenuata increase as they grow. Prey-derived As- and Cd-induced health threats were found in L. hosei, and G. griseus.

Cytotoxic effect of pingyangmycin on cultured KB cells.

The antitumour antibiotic pingyangmycin (PYM; bleomycin A5) was isolated from many components of bleomycin (BLM) produced by Streptomyces pingyangensisn. PYM has a similar chemical structure to that of BLM but the terminal amine moiety is different. Therefore, it would be of significance to demonstrate the antitumour effect and action mechanism of PYM on cultivated tumour cells. In this study, we used the cell growth curve, plating efficiency, and DNA synthesis inhibition assay to demonstrate the cytotoxicity of PYM on cultured KB cells. In the meantime, the morphological variations of drug-treated cells were also observed. In addition, we used the DNA precipitation assay, a simple and rapid assay, for detecting DNA damage caused by PYM on cultured KB cells for potential genotoxicity. Our results indicate that the effect of PYM significantly inhibits the cell growth, colonyforming ability, and DNA synthesis of KB cells in a dose-dependent manner. Furthermore, when treated with 5 micrograms/ml of PYM for 24 h on cultured KB cells, DNA strand breaks can be induced (P < 0.05). Therefore, it is considered that the action mechanism of PYM is due to its ability to inhibit the synthesis of DNA and split the DNA chains.

Placing the trailing foot closer to an obstacle reduces flexion of the hip, knee, and ankle to increase the risk of tripping.

This study was performed to test the hypothesis that reducing the horizontal distance between the trailing foot (foot crossing the obstacle last) and obstacle, during stance just prior to stepping over the obstacle, would reduce flexion of the hip, knee, and ankle joints of the trailing limb when the toe is over the obstacle to reduce the vertical toe-obstacle clearance and increase the risk of tripping. Fourteen healthy young adults stepped over an obstacle of 51, 102, 153, and 204 mm height in a self-selected manner (i.e., toe-obstacle distance was not controlled) and for toe-obstacle distance targets of 10, 20, 30, and 40% of their step lengths measured during unobstructed gait. The reductions in toe-obstacle distance resulted in linear decreases in flexion of the hip, knee, and ankle when the toe was over the obstacle. Toe-obstacle clearance of the trailing limb decreased significantly as toe-obstacle distance decreased. The reductions in toe-obstacle distance led to contact of the trailing (but not the leading) foot with the obstacle, the closer the obstacle the greater the number of contacts. The reductions also resulted in linear decreases in swing time of the trailing limb from toe-off to when the toe was over the obstacle. The height of the hip was not affected by toe-obstacle distance. Angular velocity of knee flexion was found to increase linearly as toe-obstacle distance decreased and appears to be of primary importance in avoiding obstacle contact.

Stepping over an obstacle increases the motions and moments of the joints of the trailing limb in young adults.

Tripping over obstacles is the most frequently mentioned causes of falls. Thus, this study was performed to test the hypotheses that when crossing obstacles, toe-obstacle clearance and the three-dimensional motions and moments at the hip, knee, and ankle of the trailing limb (limb crossing the obstacle last) increase with obstacle height. Data were collected using an optoelectronic digitizing system and force platform. Fourteen healthy young adults were tested during unobstructed level walking and when stepping over obstacles of 51, 102, 153, or 204 mm heights. Toe-obstacle clearances of the trailing foot increased from 31 mm during unobstructed gait to an average of 146 mm when stepping over obstacles of any of these heights. Obstacle height was not found to affect toe-obstacle clearance. When the toe of the trailing limb was over the obstacle, the flexion angles of the hip and knee increased linerly with obstacle height. Compared to flexion of the hip or ankle, flexion of the knee appears to be of primary importance when crossing obstacles with the trailing limb. The maximum extension moment at the hip joint during late stance decreased linearly with obstacle height. At the knee joint, the maximum flexion moment during early stance and the maximum adduction moment during late stance increased linearly with obstacle height. At the ankle joint, the maximum dorsiflexion moment during late stance increased linearly with obstacle height. These greater demands on motions and moments may affect the abilities of those elderly having decreased muscle strengths to step over obstacles.

Predicting the kinematics and kinetics of gait based on the optimum trajectory of the swing limb.

An algorithm was developed to predict the minimum energy consumption trajectory of the swing limb. The method of dynamic programming, a multistage optimization method, was applied to generate the optimum trajectory of the swing ankle which minimized the mechanical energy required to generate the moments of the joints of the lower extremities during the single support phase of gait. Predictions and measurements of gait were compared for six healthy subjects. The predicted hip and knee flexion angles of the swing limb were not significantly different from those experimentally measured except for hip flexion at times greater than 75% of the swing period. The predicted ground reaction forces were not significantly different from the measured ground reaction forces. Furthermore, the moments about the joints were not significantly different from those computed using the measured ground reaction forces and kinematics of the limbs. The results of this study support the hypothesis that human gait is energy efficient.

Minimum energy trajectories of the swing ankle when stepping over obstacles of different heights.

This study was performed to test the hypothesis that the motion of the lower extremities when stepping over obstacles is governed by the criterion of minimum mechanical energy. The trajectories of the swing ankle during level walking and when stepping over obstacles of 51, 102, 153, and 204 mm heights were predicted and measured for eight healthy young adults. The predictions were made with a planar, seven-link linkage model based on the criterion of minimum mechanical energy using the method of dynamic programming. When stepping over obstacles, the predicted trajectories of the swing ankle were just high enough for the swing toe to clear the obstacles. The clearances measured between the obstacle and toe were significantly larger than those predicted. When stepping over obstacles the levels of work required to generate the measured trajectories were significantly larger (p < or = 0.002) than those required to produce the predicted trajectories. The amount of work necessary to generate the measured or predicted trajectories increased linearly (significant at p < or = 0.022) with obstacle height and, except when predicting the trajectory for the lowest obstacle, was significantly greater than that required when walking on level ground (p < 0.02). Thus, conservation of energy was found to become a less dominant criterion for governing the motion of the body when crossing obstacles than when walking on level ground.

In vitro evaluation of the cytotoxicity and genotoxicity of root canal medicines on human pulp fibroblasts.

An intracanal medicine is often required because microorganisms in the dentinal tubes may be difficult to eliminate completely by instrumentation. Phenolic compounds are widely used in dental treatment as sedatives for the dental pulp or as disinfectants for caries and the root canal. In this study, propidium iodide fluorescence and DNA precipitation assay were used to investigated the cytotoxic and genotoxic effects of camphorated phenol and camphorated parachlorophenol on cultured human pulp fibroblasts in vitro. Both medicines reduced the content of double-stranded polynucleic acid of fibroblasts over a 24-h culture period in a concentration-dependent manner. Camphorated parachlorophenol was more cytotoxic than camphorated phenol. But, both medicines did not cause genotoxicity on pulp cells. The advantage of these experimental methods are simplicity and rapidity. Furthermore, this experimental system may be useful for preliminary cytotoxicity and genotoxicity screening of various dental medicines in vitro.

Effects of camphorated parachlorophenol on human periodontal ligament cells in vitro.

To date, there has been very little research into the possible effects of endodontic therapy on regeneration of a lost periodontal attachment. The objective of this study was to examine the effects of the endodontic medication, camphorated parachlorophenol (CMCP), on human periodontal ligament cells in vitro. The cytotoxic effects of CMCP were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay and cell proliferation using a [3H]thymidine incorporation assay. CMCP inhibited the human periodontal ligament cells viability and proliferation in a dose-dependent manner (p < 0.05). These data indicate that the use of CMCP in a root canal could cause periodontium damage. Although this study was conducted in vitro, the findings suggest that it may not be advisable to use CMCP as an interim medication when a periodontal surgical procedure, especially an attempt at regeneration or a new attachment procedure, is being considered in tissues adjacent to the endodontically involved tooth.

The effect of ankle disk training on muscle reaction time in subjects with a history of ankle sprain.

The purpose of this study was to determine whether 8 weeks of ankle disk training alters ankle muscle onset latency of patients with a history of lateral ankle sprain. The training was completed by eight minimally symptomatic subjects with a history of nonrehabilitated, unilateral, inversion ankle sprain sustained between 6 and 16 months before entry into the study. Ankle inversion perturbations monitored by fine-wire electromyography were performed in four lower extremity muscles (anterior tibialis, posterior tibialis, peroneus longus, and flexor digitorum longus) of all subjects on both the injured (experimental) and noninjured (control) legs. Testing was performed at study entry and after 8 weeks of ankle disk training on the previously injured ankle. Results revealed a statistically significant decrease in the anterior tibialis onset latency in both the experimental (67.6 +/- 20.3 to 51.7 +/- 17.6) and control (65.5 +/- 9.8 to 53.8 +/- 23.7) ankles after the training period. These findings indicate that muscle onset latency decreases in specific ankle muscle groups after ankle disk training in previously injured ankles. Both the experimental and control ankles demonstrated a significant change, which raises the question as to whether a proprioceptive cross-training effect occurred.

Motion of the whole body's center of mass when stepping over obstacles of different heights.

Tripping over obstacles and imbalance during gait were reported as two of the most common causes of falls in the elderly. Imbalance of the whole body during obstacle crossing may cause inappropriate movement of the lower extremities and result in foot-obstacle contact. Thus, this study was performed to investigate the effect of obstacle height on the motion of the whole body's center of mass (COM) and its interaction with the center of pressure (COP) of the stance foot while negotiating obstacles. Six healthy young adults were instructed to perform unobstructed level walking and to step over obstacles of heights corresponding to 2.5, 5, 10, and 15% of the subject's height, all at a comfortable self-selected speed while walking barefoot. A 13-link biomechanical model of the human body was used to compute the kinematics of the whole body's COM. Stepping over the higher obstacles resulted in significantly greater ranges of motion of the COM in the anterior-posterior and vertical directions, a greater velocity of the COM in the vertical direction, and a greater anterior-posterior distance between the COM and COP. In contrast, the motion of the COM in the medial-lateral direction was less likely to be affected when negotiating obstacles of different heights.

Biofilter treatment of aquaculture water for reuse applications.

Biotreatment of aquaculture water for recirculation purposes is a sensible mean to support the further growth of aquaculture industry without excessive water demands that are environmentally unsustainable. This study evaluates the efficacy of biofilter treatment of an eel (Anguilla japonica) culture pond water using different filter media and flow scheme arrangements. The experimental results demonstrate that biofilter systems packed with suitable filter media are capable of improving the quality of effluents for recirculation applications. The characteristics of the filter media appear to be more critical than biofilter flow scheme arrangements in affecting the efficacy of the biofilter treatment. Filter media with surface and structural characteristics are conducive to the development of biofilms and the capture of organic suspended matter are desirable to ensure good and consistent biofilter performance. Under such circumstances the bacterial "consortia" in the biofilter are capable of utilizing the captured organic suspended matter as an alternative substrate to support their metabolic activities when the concentration of the primary substrate (i.e., BOD) is low. For the eel pond water, a biofilter packed with filter media having cross-link structures and a high bed porosity, followed by another biofilter packed with a type of filter media having rough surfaces, produced the best results under the conditions tested. Moreover, a preliminary cost-benefit analysis confirms its cost advantages.

Diazepam facilitates reflex bradycardia in conscious rats.

The effects of diazepam on cardiovascular function were assessed in conscious rats. Intravenous administration of diazepam (1-30 mg kg-1) produced a dose-dependent decrease in both the mean arterial pressure and the heart rate. Also, reflex bradycardia was produced in rats by intravenous infusion of adrenaline (1.25-2.5 micrograms kg-1). Intravenous pretreatment of the rats with diazepam, although causing no change in the adrenaline-induced pressor effect, did enhance the adrenaline-induced reflex bradycardia. However, the diazepam enhancement of adrenaline-induced reflex bradycardia was antagonized by pretreatment of rats with an intravenous dose of picrotoxin (an agent blocks chloride channels by binding to sites associated with the benzodiazepine-GABA-chloride channel macromolecular complex). The data indicate that diazepam acts through the benzodiazepine-GABA-chloride channel macromolecular complex within the central nervous system to facilitate reflex bradycardia mediated through baroreceptor reflexes in response to an acute increase in arterial pressure.

The protection against and treatment of a liquid propane freeze injury: an experimental model.

Liquid propane causes a severe, deep thermal injury in unprotected tissue. Delayed surgical intervention, as for thermal burns, has been the gold standard of treatment. An animal model of liquid-propane injury was devised to document injury, to demonstrate a better method of protection, and to define an appropriate management protocol. Twenty-eight rats were classified into four groups: unprotected tissue (n = 8), skin covered with wool (n = 8), skin covered with Neoprene (Wm. H. Horn & Brothers Inc., Philadelphia, Pa.) (n = 8), and skin covered with wool plus Neoprene (n = 4). Each group was subdivided into two exposure times: 6 seconds and 30 seconds. The mean temperatures +/- standard error of the mean of the various tissue levels initially and at 6 and 30 seconds of exposure were determined. Histologic examination demonstrated that full-thickness tissue necrosis occurred in unprotected and wool-covered tissue. Areas that were covered with Neoprene showed intact skin and subcutaneous tissue with underlying muscle necrosis. Examination of the tissue that was covered with wool plus Neoprene showed no histologic damage. There was no sign of tissue regeneration at the wound periphery, and there was no histologic difference in any group, whether the examination took place at 1 or 5 days after injury. This study demonstrated that the best form of protection appears to be a wool glove liner covered with a Neoprene glove. The histologic evidence suggests that a liquid-propane injury to unprotected tissue should be managed aggressively with early excision and grafting.

Rare earth filters for intraoral radiography: exposure reduction as a function of kV(p) with comparisons of image quality.

Radiographs of phantoms were produced using E-speed film and various rare earth X-ray beam filters. The rare earth filters considerably reduced the amount of radiation needed to produce diagnostic quality images and, in many cases, improved image quality. These filters can be implemented easily and inexpensively in a clinical setting, resulting in radiation exposure reductions of up to 71%.

Effects of intra-raphe injection of amino acids on cardiovascular function in rats.

The effects of microinjection of an excitatory amino acid (glutamate, 10 micrograms) or several inhibitory amino acids (taurine 10 micrograms, GABA 10 ug or glycine 10 ug) into the dorsal raphe region on cardiovascular function were assessed in rats under pentobarbital sodium. Intra-raphe administration of glutamate, but not saline, caused an increase in the mean arterial pressure. By contrast, intra-raphe administration of taurine, GABA or glycine, but not saline, caused a decrease in both the mean arterial pressure and the heart rate. The glutamate-induced hypertension or both the hypotension and the bradycardia induced by taurine, GABA or glycine was antagonized by pretreatment with intra-raphe injection of a serotonergic receptor antagonist (1 ug cyproheptadine). In addition, the vasopressor and bradycardia responses to an intravenous dose of epinephrine (2.5 ug/kg) were assessed in saline-treated rats and amino acid-treated rats. Intra-raphe injection of glutamate produced a significant decrease in reflex bradycardia compared to the controls. On the other hand, administration of taurine, GABA or glycine into the dorsal raphe region led to an enhancement of epinephrine-induced bradycardia. Again, the reduction or the facilitation of the epinephrine-induced bradycardia following administration of these amino acids was antagonized by pretreatment with cyproheptadine. The results suggest that the serotonergic receptor mechanisms in the dorsal raphe region play a role in the elaboration or modulation of the cardiovascular responses to amino acids (including glutamate, taurine, GABA and glycine).

Effects of L-glutamic acid on acid secretion and mucosal blood flow in the rat stomach.

The effect of intravenous administration of L-glutamic acid (L-Glu) on gastric acid secretion and gastric mucosal blood flow (GMBF) in anesthetized rats were investigated. Infusion with synthetic L-Glu alone had no effect on spontaneous acid secretion. However, L-Glu reduced histamine- (2 mg/kg/hr) or oxotremorine- (1 microg/kg/hr) stimulated acid secretion, whereas L-Glu had no effect on acid secretion induced by pentagastrin (8 microg/kg/hr). Furthermore, this inhibitory effect of L-Glu on histamine- or oxotremorine-stimulated acid secretion was blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX), a non-NMDA receptor antagonist. The effect of L-Glu on gastric mucosal microcirculation in the anesthetized rats was evaluated by using Laser Doppler Flowmetry (LDF). The results showed that L-Glu did not significantly reduce both mucosal and serosal blood flow in stomach. No significant modulatory effect on histamine- or oxotremorine-stimulated increase in GMBF was noted after infusion with L-Glu. It is concluded that L-glutamic acid is capable of the modulating of gastric acid secretion via ionotropic non-NMDA receptors, but do not affect on GMBF. However, L-glutamic acid showed no effect on acid secretion by itself.

Protein gene product 9.5-immunoreactive neurons in the retina of striped dolphin (Stenella coeruleoalba) and Fraser dolphin (Lagenodelphis hosei).

This study demonstrates immunocytochemically that protein gene product 9.5 (PGP 9.5), a neuronal marker, is expressed by various populations of retinal cells in Stenella coeruleoalba (striped dolphin) and Lagenodelphis hosei (Fraser dolphin): one in the retinal ganglion cells and the other in the inner nuclear layer, resembling horizontal and amacrine cells. The specific distribution of PGP 9.5 in a dolphin closely resembles that in rodents and carnivores; however, some differences arise among these animals. In a dolphin's retina, for example, only a few of giant ganglion cells are immunoreacted while almost all the small ganglion cells are stained strongly. The processes of horizontal cells, identified according to their localization, appear not to connect entirely in a dolphin. Instead, PGP 9.5 positive cells are widely distributed in the small to moderate ganglion cells and have distinct processes which are ramified extensively in the outer plexiform layer in rodents and carnivores. The high levels of PGP 9.5 expressing in the inner part of dolphin retina, including ganglion cells and their axons as well as distinct sublamination in the inner plexiform layer, indicate that this molecule markedly influences the retinal system, possibly in visual connection. Although mammals have various visual behavior, i.e., living marine vs. terrestrial environment, and active during daytime vs. in the night, the retina is a common model to characterize the neurochemical properties.

Attentional deficits in concussion.

PRIMARY OBJECTIVE: The purpose of the present study was to examine deficits in the alerting, orienting and executive components of attention in individuals who have recently suffered a concussion. RESEARCH DESIGN: A group design was used in which the performance by individuals with concussion was compared to control subjects matched for age, height, weight and activity level. METHODS AND PROCEDURES: Participants completed the Attentional Network Test (ANT) that breaks down attention into alerting, orienting and executive components. Reaction time and response accuracy were the dependent variables. MAIN OUTCOMES AND RESULTS: It was found that only the orienting and executive components of attention were affected by concussion, whereas the alerting component was normal. Furthermore, participants with concussion required a significantly longer time than controls to initiate correct responses. CONCLUSIONS: These results suggest that the orienting and executive components of attention are most susceptible to the effects of concussion.

Ganglioneuroma of the mandible.

This article reports a very rare case of ganglioneuroma within the mandible. The patient, 15 years of age at first diagnosis, has now had 17 years of followup and remains generally healthy, despite the continued presence of the tumor. Possible origin of the lesion, histologic differentiation of this tumor from normal ganglia, and recommendations for management are discussed. Two reported cases of ganglioneuroma that occurred centrally in the mandible are also reviewed.