The eukaryotic cell is compartmentalized by a series of vesicular organelles which constitute the endocytic and exocytic transport pathways. Each vesicular compartment has distinct sets of membrane proteins, structures and functions. Despite continuous vesicular transport, each vesicular compartment maintains its structure and function by use of retention and retrieval signal for its own resident proteins. Proteins in transit along the endocytic and exocytic pathway are transported without admixing with cytoplasmic constituents by successive steps of budding from the donor vesicles, formation of intermediate transport vesicles, transport, targeting to and fusion with acceptor vesicles. Specificity and fidelity of the vesicular transport are conferred by vesicular membrane proteins and small molecular weight GTP-binding proteins of the Rab subfamily. Proteins for export are packaged into specific vesicles for their final destinations. Insertion into and retrieval from the plasma membrane of transport proteins in response to cellular stimulus are a new paradigm of cellular regulatory mechanism. Secretion of neurotransmitters, hormones and enzymes by exocytosis involves a complex set of cytosolic proteins, G-proteins, proteins on the secretory granule membrane and plasma membrane. Much progress has been recently made in identifying proteins and factors involved in the exocytosis. But the molecular interactions among identified proteins and regulatory factors are unknown and remain to be elucidated. Finally our chemiosmotic hypothesis which involves the H+ electrochemical gradient across the secretory granule membrane generated by an ATP-dependent electrogenic H(+)-ATPase as the potential driving force for fusion and release of granule contents will be discussed.
Biological Transport ; *Exocytosis ; Human ; Organelles/*metabolism ; Support, Non-U.S. Gov't

Effect of varying hematocrit ratio on the gastric acid production was studied in the heart-stomach preparation of the frog. When the hematocrit ratio was raised by injecting packed red blood cells obtained from the same species of frog, the acid production was increased significantly as compared to the low hematocrit group in which hematocrit ratio was lowered by injecting frog's normal saline. When a small amount of histamine was added to the medium of 25degree C, the acid production was increased in all cases, but the difference in the acid production between the high and the low hematocrit groups was abolished. However, when the temperature of the medium was lowered to 15degree C, the differences in the acid production between the two groups became significant. When a large amount of acetazolamide was added to the medium at 25degree C, the acid production was decreased significantly in both groups without showing a significant difference between the two groups. The reason(s) responsible for the increased acid production in the high hematocrit group was discussed.

BACKGROUND: The effect of arterial carbon dioxide tension (PaCO2) during ischemia and reperfusion has been a controversial issue. In this study, the effect of PaCO2 during ischemia and reperfusion was evaluated by 31P magnetic resonance spectroscopy (MRS). METHODS: Incomplete global cerebral ischemia was induced by ligation of carotid artery under lowered mean blood pressure (mean blood pressure= 40 mmHg) for 30 minutes followed by 2 hours of reperfusion. Eighteen cats were divided into 3 groups: For group 1 (n=6) (control group), animals were subjected to normocarbia (PaCO2=28~33 mmHg) during ischemia and reperfusion, for group 2 (n=6), animals were subjected to hypocarbia (PaCO2=18~23 mmHg) during ischemia and reperfusion, and for group 3 (n=6), animals were subjected to normocarbia during ischemia and hypocarbia during reperfusion. RESULTS: For group 1, the energy metabolism measured by [PCr/Pi] was recovered about 74.7 6.4%. For group 2, the energy metabolism failed to be completely recovered by 120 minutes of reperfusion (69.3 7.3%), whereas for group 3, the energy matabolism was completely recovered by 120 minutes of reperfusion (97.6 2.4%). There were statistically significant differences between group 1 and group 3 (p<0.05). The changes in pH were not significantly different among the groups. CONCLUSION: In this study, a condition of hypocarbia during reperfusion seems better for the energy metabolism after incomplete global ischemia of cats.
Animals ; Blood Pressure ; Brain Ischemia ; Brain* ; Carbon Dioxide ; Carotid Arteries ; Cats* ; Energy Metabolism* ; Hydrogen-Ion Concentration ; Ischemia ; Ligation ; Magnetic Resonance Spectroscopy ; Reperfusion

The genome of Hantaan virus, the prototype of the hantavirus genus, is composed of three segmented, single stranded negative sense RNA genome. The 5' and 3' termini of the Hantaan virus RNA genome contain noncoding regions (NCRs) that are highly conserved and complementary to form panhandle stuctures. There are some reports that these NCRs seems to control gene expression and viral replication in influenza virus and vesicular stomatitis virus. In this study, we examined whether NCRs in Hantaan virus play a role in expression of the viral nucleocapsid protein (Np) and foreign (luciferase) gene. The 5' and/or 3' NCR-deleted mutants were constructed and analysed. The Np expression of 5' NCR-deleted clone, it showed 40% reduction. To investigate the role of NCR in foreign gene expression, the clones which are replaced ORF of Hantaan viral Np gene with that of luciferase gene were constructed. The results were similar to those of the experiments using Np gene. These results suggest that 3' NCR is more important than 5' NCR in protein expression. To find out a critical region of 3' NCR in more important than 5' NCR in protein expression. To find out a critical region of 3' NCR in protein expression, several clones with a deleted part of 3' NCR were constructed and analyzed. The deletion of the conserved region in 3' NCR showed 20~30% decrease in Np expression. However there were no change in luciferase activities between clones with or without non-conserved region of 3' NCR. These results suggest that the 3' NCR of Hantaan virus S genome, especially conserved region in 3' NCR, plays and important role in the expression of Hantaan viral Np and foreign genes.
Animals ; Clone Cells ; Ecthyma, Contagious ; Gene Expression ; Genome* ; Hantaan virus ; Hantavirus ; Luciferases ; Nucleocapsid Proteins* ; Nucleocapsid* ; Orthomyxoviridae ; RNA ; Vesicular Stomatitis

No abstract available.
Acidosis, Renal Tubular*

No abstract available.
Humans ; Staphylococcal Infections*

A 43-year-old male presenting with headache and dizziness underwent craniotomy and gross total resection of an extraaxial tumor was achieved via left occipital interhemispheric approach. The tumor was diagnosed as papillary meningioma arising from the left falcotentorium with such pathologic characteristics of bronchoalveolar adenocarcinoma. At postoperative day 40, he developed generalized tonic clonic seizure and then progressed to a status epilepticus pattern. Brain magnetic resonance imaging showed irregular leptomeningeal enhancement with a significant peritumoral area. Through a cerebrospinal fluid (CSF) study, we identified the meningioma cells of the papillary type from the CSF. At the postoperative day 60, he fell into semicomatose state, and the computed tomography imaging showed low density on both cerebral hemispheres, except the basal ganglia and cerebellum, with overall brain swelling and an increased intracranial pressure. He died on the following day. We experienced a rare case of a papillary meningioma with leptomeningeal seeding.
Adenocarcinoma ; Adult ; Basal Ganglia ; Brain ; Brain Edema ; Cerebellum ; Cerebrum ; Craniotomy ; Dizziness ; Headache ; Humans ; Intracranial Pressure ; Magnetic Resonance Imaging ; Male ; Meningioma ; Seeds ; Seizures ; Status Epilepticus

BACKGROUND: Incorrect infusion of dopamine can be potentially life threatening. If the actual volume of a 100 ml intravenous bag or bottle used to mix dopamine solutions is greater than the labeled volume, overdilution of dopamine can occur, resulting in ineffective hemodynamic response. To determine the significance of dopamine overdilution induced by the excessive volume, dopamine concentration and hemodynamic effect were compared in the manually mixed dopamine and the manufactured premixed dopamine. METHODS: For 5% dextrose water (D5W) 100 ml intravenous bottle mixed with 160 mg (4 ml) of dopamine (group 1), D5W 96 ml mixed with 160 mg of dopamine (group 2), premixed dopamine with 1.6 mg/ml of concentration manufactured 2 months ago (group 3), premixed dopamine with 1.6 mg/ml of concentration manufactured 6 months ago (group 4), and D5W 100 ml intravenous bottle mixed with 160 mg (4 ml) of dopamine after removal of 4 ml dextrose water (group 5), dopamine concentration was measured by High performance liquid chromatography (HPLC). Hemodynamic data was obtained from 10 mongrel dogs for each group at baseline (T1), 15 minutes after dopamine infusion at a rate of 3 microgram/kg/min (T2), 8 microgram/kg/min (T3), and 15 microgram/kg/min (T4). RESULTS: Dopamine concentrations of group 1, 2, 3, 4, and 5 were 1.51+/- 0.09, 1.60 +/- 0.10, 1.63 +/- 0.06, 1.57+/- 0.08 and 1.57+/- 0.07 mg/ml, respectively. Group 1 showed a significantly low concentration (p< 0.05). There was no significant differences in all hemodynamic data between group 1, 2, 3, and 4. In group 1, however, there was no significant increase in both mean blood pressure at T4 and mixed venous oxygen saturation at T3 compared with T1. CONCLUSIONS: The actual volume of D5W in 100 ml intravenous bottle is greater than the labeled, and therefore can cause significant overdilution of dopamine. Premixed dopamine, however, has the same concentration and hemodynamic effects as the dopamine mixed manually but precisely.
Animals ; Blood Pressure ; Chromatography, Liquid ; Dogs ; Dopamine* ; Glucose ; Hemodynamics* ; Oxygen ; Water

BACKGROUND: Lidocaine is a well known antiarrhythmic agent. However, recent reports indicate that indocaine has myocardial protective effects on acute myocardial ischemia and reperfusion. The exact mechanism of myocardial protection of lidocaine is still not clearly understood. In this study we intended to assess the effects of lidocaine on high energy phosphate metabolism in cats subjected to myocardial ischemia-reperfusion by using 31P MR spectroscopy. Effect of lidocaine on size of infarct will also be evaluated by 2, 3, 5-triphenyltetrazolium chloride(TTC) staining. METHODS: Twenty-seven cats were used for this study. The animals were divided into three groups : for group 1(n=10) and group 2(n=7), animals were subjected to a 90 min of LAD occlusion followed by a 90 min of reperfusion ; for group 3(n=10), a 20 min of occlusion followed by a 90 min of reperfusion. In group 2 and group 3, lidocaine(5mg/kg/hr) was infused continuously during the occlusion and reperfusion periods with an initial bolus injection(1mg/kg) before ligation of LAD. In-vivo MR spectroscopy was performed on a 4.7T Biospec System(Bruker, Switzerland). A home-made surface coil(diameter : 1.5cm) was used to receive31p signals from the myocardium underwent ischemic and reperfusion damage. RESULTS: Decrease of PCr during ischemic period was not different between each groups : PCr showed less than 30% of the baseline value at L-30 in group 1 and group 2 and at L-20 in group 3. More than 90% recovery of PCr was achieved at R-30 in group 2 and group 3, whereas less than 50% of PCr was recovered in group 1. Decrease of ATP during ischemic period was less pronounced in group 2 than in group 1 : in group 2 ATP depleted down to 25% of the baseline at L-90, whereas in group 1 ATP decreased to 50% of the baseline. Recovery of ATP during reperfusion period was not signiflcant in all three groups. On TTC staining, evidence of infarct was seen in all cases of group 1 : the area of infarct was 12.3+/-2.7% of the left ventricular mass and 23.9+/-6.1% of the area at risk. On the contrary, there was no evidence of infact in any case of group 2 and group 3. CONCLUSION: In this study, we found that lidocaine has myocardial protecitve effects on ischemia-reperfusion in cats. Lidocaine improves high energy phosphorous metabolism during ischemia and reperfusion as well as reduces infarct size.
Adenosine Triphosphate ; Animals ; Cats* ; Ischemia ; Lidocaine* ; Ligation ; Magnetic Resonance Spectroscopy ; Metabolism ; Myocardial Ischemia ; Myocardium ; Polymerase Chain Reaction ; Reperfusion ; Reperfusion Injury

Aniskiasis is caused by the accidental infestation of human by larvae of marine mammals found in saltwater fish and squid. The clinical picture may be severe enough to stimulate an acute surgical abdomen. More commonly, colicky pain, diffuse abdominal tenderness, nausea, vomiting, fever, and leukocytosis are seen. Gastroscopically, 2-to 4-cm larvae can be seen penetrating the mucosa. More characteristically, the larvae burrow into the mucosa of the stomach. Here they produce eosinophilic granulomatous tumors with edema, thickening, and induration which may be mistaken for gastric canceer. The pathalogic changes are thought to be the result of a hypersensitivity reaction. We report a case of chronic gastric anisakiasis, which was diagnosed as submucosal tumor with massive bleeding.
Abdomen ; Anisakiasis* ; Abdominal Pain ; Decapodiformes ; Edema ; Eosinophils ; Fever ; Hemorrhage* ; Humans ; Hypersensitivity ; Larva ; Leukocytosis ; Mammals ; Mucous Membrane ; Nausea ; Stomach ; Vomiting