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PubMed1998

[Migration and transposition of Oesophagostomum quadrispinulatum larvae from feces].

Investigations on the migration and translation of free-living stages of Oesophagostomum quadrispinulatum, using faeces containing eggs as starting material, revealed that mostly third stage larvae and very few second stage larvae migrated out of faeces, whereas first stage larvae remained in the faeces. The emigration rates depended on ambient relative humidity. Compared with the control, third stage larvae emigrated out of faeces at rates of 0.3%, 1.6% and 12.2% at 50%, 75% and 100% relative humidity, respectively. Offering helminth-free faeces, emigrated third stage larvae returned into faces at rates of 0.4-1.2%, 5.8-17.7%, 39.0-52.7%, and 45.2-60.7% after 1 h, 24 h, 5 days and 14 days, respectively. After a period of 1, 2, 3 or 4 weeks staying out of faeces, emigrated third stage larvae returned into faeces at rates of 23.3%, 8.8%, 22.1% and 6.0%, respectively. An examination of the horizontal translation revealed that most of the third stage larvae migrated distances up to 80 cm and a few even up to 150 cm returning into helminth-free faeces.

Animals↗
PubMed2003

Integrating stress physiology, environmental change, and behavior in free-living sparrows.

As weather deteriorates, breeding animals have a diverse array of options to ensure survival. Because of their mobility, birds can easily abandon territories to seek out benign conditions away from the breeding site. The timing of abandonment, however, may have repercussions for territory size, mate quality, reproductive success, and survival. There is a large body of evidence indicating that the adrenocortical response to stress plays a role in mediating the onset and maintenance of this behavioral switch. Here we develop a model describing the interactions of weather, food availability, body condition, and stress physiology in initiating departure from the breeding site. We tested the model using a population of white-crowned sparrows breeding at high elevation in the Sierra Nevada, where severe weather at the beginning of the breeding season often induces temporary abandonment of breeding territories and facultative altitudinal migration to lower elevation refugia. The data show that (1). during inclement weather, exogenous corticosterone delays return to the breeding site after territory abandonment; (2). during good weather, exogenous corticosterone alone does not induce territory abandonment, but does increase activity range around the breeding site; and (3). the magnitude of the corticosteroid response to stress is inversely related to body condition of the sparrow.

Adipose Tissue↗
PubMed2004

Tyrosine hydroxylase and dopamine transporter expression following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurodegeneration of the mouse nigrostriatal pathway.

Administration of the neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to C57BL/6 mice targets nigrostriatal dopaminergic neurons, leading to cell death and the depletion of striatal dopamine. After MPTP lesioning in young adult mice, surviving nigrostriatal dopaminergic neurons display robust and reproducible return of striatal dopamine weeks to months after injury. Thus, the mouse provides an excellent model with which to investigate the mechanisms underlying neuroplasticity of the nigrostriatal system following neurotoxic injury. The purpose of this study was to analyze proteins and mRNA transcripts of genes involved in dopamine biosynthesis (tyrosine hydroxylase; TH) and uptake (dopamine transporter; DAT) with regard to time course (7-90 days) after MPTP lesioning. Molecular analysis using immunohistochemistry and Western immunoblotting techniques demonstrated an increase in striatal TH by 30-60 days postlesioning that returned to near-control (prelesioned) levels by 60-90 days. In situ hybridization histochemistry indicated that this increase in TH protein might be due in part to increased TH mRNA expression in surviving nigrostriatal dopaminergic neurons. Analysis of TH protein at 7, 30, 60, and 90 days postlesioning with two-dimensional polyacrylamide gel electrophoresis in conjunction with Western immunoblotting revealed altered TH protein isoforms migrating at isoelectric points different from those of the native isoform. In contrast to TH protein, which returned to prelesioned levels by 60 days, DAT protein analysis showed that increased expression of striatal DAT protein did not return to near-prelesion levels until 90 days postlesioning. These results suggest that TH and DAT may differ in their time course of expression in surviving dopaminergic neurons and may play a role in mediating the return of striatal dopamine.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1982

In situ demonstration of actin in normal and injured ocular tissues using 7-nitrobenz-2-oxa-1,3-diazole phallacidin.

The fluorescent derivative of the actin-binding toxin phallacidin, 7-nitrobenz-2-oxa-1,3 diazole phallacidin, has been used to cytologically demonstrate the presence of actin in lens epithelium, corneal endothelium, and retinal pigment epithelium. In these noninjured tissues, no stress fibers are observed and fluorescence is confined mainly to an area at or near the cell membrane, although some diffuse cytoplasmic staining can also be seen. However, following injury to either the lens epithelium or corneal endothelium of rats and frogs, stress fibers are detected, but only in those cells that migrate into the wound area. Cells on the periphery of each tissue do not partake in would repair and thus maintain their normal appearance. After the tissue has regenerated, stress fibers disappear, and those cells involved in the injury response return to their normal morphology. When rabbit corneal endothelium is placed in tissue culture, stress fibers are observed as the cells migrate away from the initial explant. Upon reaching confluency, these cells spread out and each is surrounded by thick actin-containing bands. Furthermore, they exhibit some stress cables within their cytoplasm. This is in contrast to their appearance in vivo where stress fibers are absent and fluorescence is limited to a region near the cell membrane.

Actins↗
PubMedDate not supplied

Digestive response to restricted feeding in migratory yellow-rumped warblers.

Smaller guts and slow initial mass gains at stopover sites have led to the idea that digestive physiology limits refueling rates in migrating birds. We tested the digestive-limitation hypothesis in yellow-rumped warblers using food restriction to simulate infrequent feeding during migration, which may cause a reduction in alimentary tract mass. Restricted birds had small intestine, pancreas, and liver masses 18%-22% lower than ad lib.-fed controls. Total activities of sucrase, maltase, aminopeptidase, and amylase were significantly lower in restricted birds, while those of trypsin and chymotrypsin were not. Only aminopeptidase mass-specific activity was significantly lower in restricted birds. Previously restricted birds were able to feed and digest at a high rate immediately following return to ad lib. feeding. Digestive efficiency did not differ between groups. These results suggest that before migration yellow-rumped warblers have some spare digestive capacity to compensate for declines in their digestive organ masses during migration.

Adaptation, Physiological↗
PubMed1987

Mitochondrial migration and Ca-ATPase modulation in secretory ameloblasts of fasted and calcium-loaded rats.

Migration of mitochondria and modulation of Ca-ATPase activity in secretory ameloblasts were investigated ultrastructurally and ultracytochemically by using lower incisors taken from normally fed, 30-hr-fasted, and calcium (Ca)-loaded rats. In normally fed rats, almost all mitochondria were localized in a narrow infranuclear compartment between the nucleus and proximal cell webs of secretory ameloblasts. In 30-hr-fasted rats, a prominent migration of many mitochondria into the supranuclear region of the cells was noted. Mitochondria returned to the infranuclear compartment and seldom appeared in the supranuclear region when fasted rats were Ca-loaded by transcardiac perfusion with physiological Ca solution. Normally, the mitochondria of secretory ameloblast exhibited moderate Ca-ATPase activity along their inner membranes. This mitochondrial Ca-ATPase was decreased by a 30-hr fast and became prominent again after Ca loading. Plasma-membrane Ca-ATPase was demonstrated in the entire cell surface of secretory ameloblasts. An especially abundant reaction was found along the invaginated cell surface of the Tomes process. This Ca-ATPase also became very weak and was almost abolished from the Tomes process after fasting, but Ca loading caused reappearance of an intense Ca-ATPase activity on the entire cell surface, including along Tomes's processes. These results suggest that 1) mitochondrial localization in secretory ameloblasts is influenced by the Ca concentration of the extracellular milieu, and 2) the level of mitochondrial and cell-membrane ATPase activity is responsive to the concentration of extracellular calcium.

Ameloblasts↗
PubMed1985

An immunohistochemical study of seasonal changes in luteinizing hormone-releasing hormone and vasotocin in the forebrain and the neurohypophysis of the toad, Bufo japonicus.

Seasonal changes in luteinizing hormone-releasing hormone (LH-RH) and arginine vasotocin (AVT) were examined immunohistochemically in the toad forebrains and neurohypophyses. Strongly immunoreactive (ir-) LH-RH perikarya, from which dense ir-LH-RH fibers project to the median eminence, were localized in the medial septal nucleus and the nucleus of the diagonal band of Broca in the animals captured in the spring and the autumn. While, in the animals collected in the summer, ir-LH-RH perikarya and fibers were sparse, and immunoreactivity in the median eminences was weak. Artificially induced hibernation decreased the density of ir-LH-RH in the median eminence, in contrast with strong immunoreactivity in the control animals kept at room temperature. The amounts of ir-LH-RH in the median eminences of hibernating toads which were captured shortly before the breeding period varied conspicuously among individuals. The median eminences in migrating toads showed relatively weak LH-RH immunoreactivity. After the breeding, the immunoreactivity returned to the strong level that was observed in the spring and the autumn. These seasonal changes in ir-LH-RH seem to correspond to seasonal reproductive activity in this species. However, significant seasonal variations were not found in ir-AVT.

Acclimatization↗
PubMed1979

Effect of diethylcarbamazine on the concentration of Onchocerca volvulus microfilariae in hydrocoele fluid and urine.

The effect of graded doses of diethylcarbamazine on the concentration of microfilariae in the hydrocoele fluid, urine and skin of patients suffering from onchocerciasis was studied. The results showed that a significant number of microfilariae migrated into hydrocoele fluid and urine immediately after the drug was given and thereafter returned to pre-treatment levels rather more quickly in the former than the latter. The increase was found to be roughly directly proportional to the intensity of infection in the skin. By contrast the skin concentration of microfilariae fell sharply after treatment and remained significantly lower than pre-treatment levels for over four weeks. The potential use to which these observations could be put with respect to clinical screening of drugs in onchocerciasis is discussed.

Adult↗
PubMed1995

The olfactory system of migratory adult sea lamprey (Petromyzon marinus) is specifically and acutely sensitive to unique bile acids released by conspecific larvae.

Larval sea lamprey inhabit freshwater streams and migrate to oceans or lakes to feed after a radical metamorphosis; subsequently, mature adults return to streams to spawn. Previous observations suggested that lamprey utilize the odor of conspecific larvae to select streams for spawning. Here we report biochemical and electrophysiological evidence that this odor is comprised of two unique bile acids released by larvae. High performance liquid chromatography and mass spectrometry demonstrated that larval sea lamprey produce and release two unique bile acids, allocholic acid (ACA) and petromyzonol sulfate (PS). Electro-olfactogram (EOG) recording also demonstrated that the olfactory system of migratory adult sea lamprey is acutely and specifically sensitive to ACA and PS; detection thresholds for these compounds were approximately 10(-12) M. ACA and PS were the most potent of 38 bile acids tested and cross-adaptation experiments suggested that adult sea lamprey have specific olfactory receptor sites associated with independent signal transduction pathways for these bile acids. These receptor sites specifically recognize the key substituents of ACA and PS such as a 5 alpha-hydrogen, three axial hydroxyls, and a C-24 sulfate ester or carboxyl. In conclusion, the unique lamprey bile acids, ACA and PS, are potent and specific stimulants of the adult olfactory system, strongly supporting the hypothesis that these unique bile acids function as migratory pheromones in lamprey.

Animals↗
PubMed1994

Role of Na+:Ca2+ exchange current in Cs(+)-induced early afterdepolarizations in Purkinje fibers.

INTRODUCTION: The ionic mechanisms for early afterdepolarizations (EADs) have not been fully clarified. It has been suggested that L-type Ca2+ current (ICaL) is the primary current generating EADs that occur near the plateau level (E-EADs) of the membrane potential (Vm) when ICaL is enhanced. The purpose of these studies was to determine accurately the range of Vm at which EADs occur in Purkinje fibers with K+ currents blocked by Cs+ and to investigate the importance of Na+:Ca2+ exchange current (INa:Ca) as opposed to ICaL and other currents in the generation of EADs occurring later during repolarization (L-EADs). METHODS AND RESULTS: Shortened Purkinje strands from dogs and guinea pigs were superfused with physiologic solution containing Cs+ (3.6 mM) and a low [K+]o (3.0 or 2.0 mM) to induce EADs. The Vm of origin of EADs and their evolution were measured with the aid of phase plane plots of the rate of repolarization against Vm. L-EADs occurred over a wide range of Vm (-35 to -90 mV), generally more negative in guinea pig than in dog. Elevation of [Ca2+]o from 1.8 to 3.6 mM suppressed L-EADs within a few cycles, and they returned with continued exposure. After repeated exposures to high [Ca2+]o, L-EADs migrated toward less negative Vm when [Ca2+]o was reestablished to 1.8 mM in the presence of Cs+. Reduction of [Na+]o from 147.5 to 112.5 mM by substitution with Li+ or sucrose also rapidly depressed L-EADs. CONCLUSIONS: The observation of Cs(+)-induced L-EADs over a wide range of Vm indicates that there is not a single inward gated current as a common ionic mechanism for L-EADs but does not exclude an important role for INa:Ca, which can operate over a wide range of Vm. The rapid suppression of L-EADs with elevated [Ca2+]o and reduced [Na+]o and the migration of EADs to more positive Vm after exposures to high [Ca2+]o are compatible with INa:Ca as the major charge carrier for L-EADs.

Action Potentials↗
PubMed2000

Reproductive ecology of the blue crab, Callinectes danae Smith, 1869 in the Conceição Lagoon system, Santa Catarina Isle, Brazil.

Abundance of ovigerous females, size of the first gonadal maturation and the possible migration, route of the blue crab Callinectes danae from the Conceição Lagoon system, Santa Catarina Isle, Brazil, are described. This lagoon is connected with the coastal area through a canal. A total of 1,124 crabs was caught during a 19 month sampling period. The reproduction and recruitment of juveniles occurred all year-round, with two peaks of abundance (February and September), correlated with the presence of ovigerous females (June and January). The mean carapace width at which the crabs attained gonadal maturity for the first time was 9.4 cm in males and 8.4 cm in females. The Conceição Lagoon is a growth, reproduction, and spawning area for the species. However, egg eclosion occurs outside the lagoon following migration of ovigerous females to the open sea. After hatching the eggs, some females return to the lagoon, but males stay there for most of their life cycle.

Animals↗
PubMed2005

Treatment of benign paroxysmal positional vertigo: necessity of postmaneuver patient restrictions.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo, resulting from migration of otoconia into the semicircular canals. Several treatment methods involving positioning maneuvers that return the otoconia to the utricle have been described. Following treatment, most patients are provided with a variety of activity restrictions. Previous studies suggest that, overall, BPPV treatment may be successful without these restrictions. The purpose of this study was to determine the necessity of postmaneuver restrictions using an experimental and control group with participants matched for age, gender, involved ear, and symptoms. A canalith repositioning maneuver was used to treat the BPPV. During postmaneuver instruction, the 21 participants assigned to the restricted group were provided with typical activity restrictions. Twenty-one participants assigned to the nonrestricted group were given no postmaneuver restrictions. Only one participant in the restricted group and two participants in the nonrestricted group were not clear at the one-week follow-up appointment. Results indicated that postmaneuver restrictions do not improve treatment efficacy.

Adult↗
PubMed1998

Visualization of internalization and recycling of the gastrin releasing peptide receptor-green fluorescent protein chimera expressed in epithelial cells.

Gastrin releasing peptide (GRP) regulates critical gastrointestinal functions via the GRP receptor (GRPR). GRPR internalization and recycling have been proposed to play an important role in the cellular response to GRP. Our aim was to develop a direct method for investigating GRPR trafficking in living cells. A chimeric protein, consisting of GRPR fused to green fluorescent protein (GFP), was expressed in epithelial cells. Ligand and receptor interactions were examined with radiolabeled agonist and fluorescent imaging. In comparison with epithelial cells expressing wild-type GRPR, the GRPR-GFP expressing cells showed similar ligand binding affinity, GRP-stimulated Ca2+ signaling, and GRP-initiated internalization. In GRPR-GFP expressing cells treated with fluorescently labeled ligand, receptor and ligand trafficking was directly visualized. Upon ligand binding, the receptor-ligand complex coalesced into vesicles prior to internalization and migration to the perinuclear space. Whereas a portion of the receptors were observed to return to the plasma membrane, the ligand remained in the perinuclear space. Hyperosmolar solution prevented ligand and receptor internalization, and bafilomycin inhibited receptor recycling. We demonstrate that GRPR-GFP is physiologically similar to wild-type GRPR, and permits direct visualization of intracellular trafficking processes in individual living cells with minimal toxicity over several hours.

Animals↗
PubMed1999

Subconjunctivally implanted micro-osmotic pumps for continuous ocular treatment in horses.

OBJECTIVE: To evaluate the feasibility of using a subconjunctivally implanted micro-osmotic pump for continuous delivery of medication to the eyes of horses- during a 7-day period. ANIMALS: 4 healthy adult horses. PROCEDURE: With horses restrained in a standing position, micro-osmotic pumps were implanted subconjunctivally in each eye for 7 days. The treatment eye received an atropine-loaded micro-osmotic pump (100 microl of 1.5% atropine), and the contralateral eye received a sterile saline-loaded pump (100 microl of 0.9% NaCl) as a control treatment. Pupil size was measured at 12-hour intervals until values returned to baseline. RESULTS: The micro-osmotic pumps were tolerated and did not migrate or become dislodged. During the 7-day treatment period, pupils were significantly larger in the eyes implanted with atropine-loaded pumps, compared with saline-implanted control eyes. CONCLUSIONS AND CLINICAL RELEVANCE: Micro-osmotic pumps were implanted and removed easily from standing horses and were not associated with complications during the 7-day treatment period. Therefore, subconjunctivally implanted micro-osmotic pumps can potentially be used when treating ophthalmic disease in horses.

Animals↗
PubMed1991

[Postoperative small intestinal motility after abdominal surgery].

After abdominal surgery there is a postoperative small bowel ileus. We evaluate whether the duration of the small bowel ileus is depending on the kind of surgery or not. Over a needle catheter jejunostomy a 3-tip transducer was placed into the distal jejunum. At the end of the operations a pressure detector was connected to measure the intraluminal pressure continuously over five days. Group A consisted of three patients undergoing explorative laparotomy because of inoperable gastric cardia cancer, and group B of eight patients who underwent gastrectomy. In none of the patients a normal empty stomach motility pattern, determined by the activity of a migrating myoelectric complex (MMC) was detectable. In group A the normal MMC-activity returned after 24 +/- 4.5 h and in group B after 82 +/- 25 h. Therefore the duration of the loss of the interdigestive myoelectric complex appeared to be dependent upon the type of surgery.

Cardia↗
PubMed1991

Expandable venous stents for treatment of the Budd-Chiari syndrome.

The goals of treatment of the Budd-Chiari syndrome are relief of portal hypertension, relief of inferior vena cava syndrome, if present, and preservation of hepatic function. This study presents a patient with clinical resolution of the Budd-Chiari syndrome after placement of expandable metallic stents in the inferior vena cava and hepatic veins. A 26-year-old man with severe ascites and lower extremity edema but with relatively preserved hepatic function had a small gradient across a suprahepatic caval web, large gradients across an intrahepatic caval stenosis and the left hepatic vein, and an occluded right hepatic vein. Under angiographic control, web and caval stenosis were balloon-dilated, and modified Gianturco expandable metallic stents were placed in the intrahepatic vena cava. The left hepatic vein was dilated twice and a stent was placed. All gradients were completely eliminated. There were no complications and after 1 year, the stents have fully expanded without migration, edema and ascites have resolved, hepatic function has normalized, and the patient has returned to work. This new technique provides a simple, safe, effective, relatively inexpensive, and potentially long-lasting treatment for selected patients with the Budd-Chiari syndrome.

Adult↗
PubMed1982

Distemper virus infection in ferrets: an animal model of measles-induced immunosuppression.

Distemper virus is very similar antigenically to measles virus, and the disease produced in ferrets by distemper is a systemic illness quite similar to measles infection in humans. Using an attenuated strain of distemper virus, we produced a mild systemic illness in ferrets and were able to study the effects of the viral infection on cell-mediated immunity (CMI). Beginning on day 5 after viral inoculation and continuing to day 30, infected ferrets showed a marked lymphopenia, with a reduction in total numbers of all lymphocyte subpopulations studied. Transformation of circulating lymphocytes to the mitogens phytohemagglutinin, concanavalin A, and pokeweed mitogen was suppressed on day 5, reached a nadir by days 8 to 11, and returned toward normal by days 23 to 30 after viral inoculation. Production of macrophage migration inhibitory factor by splenic macrophages was diminished during distemper infection. In contrast to marked suppression of these in vitro assays for CMI, delayed hypersensitivity skin test responses were only slightly diminished in animals infected with distemper virus. This model should prove useful in exploring the mechanisms of measles induced immunosuppression.

Animals↗
PubMed1982

[Trichinellosis with neurological complications. Case report and short overview].

A 53-year-old, previously healthy man developed persistent diarrhea 4 days after ingestion of smoked but uncooked pork sausages in the Southern Tyrol. On his return to Switzerland he ate the same sausages and was admitted to hospital with migrating muscle pain, fever and chills. While fever and diarrhea soon regressed, the patient exhibited neurologic symptoms and change of character. The leukocyte count was 14 000/mm3 with 39% eosinophils. 40 days after hospitalization a second muscle biopsy established the diagnosis of Trichinella spiralis infection. At the same time, serologic tests were positive for Trichinella spiralis. Epidemiology, parasitology, symptomatology, diagnosis, therapy, prophylaxis and prognosis of trichinellosis are briefly discussed.

Adrenal Cortex Hormones↗