BACKGROUND: This study was aimed to observe the changes in body weight, water intake and hematological data during and after long-term head-down suspension (HDS) in rats. HDS rats induced by tail suspension has evolved as a useful model for the simulation of a microgravity or zero-gravity environment. METHODS: Unanesthetized, unrestrained, male Sprague-Dawley rats, weighing 230-270 g, were subjected to either a hori-zontal position (control horizontal, CH rats) or a 45 degreeshead-down suspension (HDS rats) for 4 weeks. We deter-mined the body weight and daily water intake in both CH and HDS rats. Hematological data including white and red blood cell counts, hemoglobin concentration and hematocrit were measured. The characteristics of red blood cell were also calculated from above hematological data in the both rats after 4 weeks of observa-tion. RESULT: In CH rats, body weight was significantly increased (P<0.05) after 4 weeks of experiment, where-as the body weight of HDS rats was only showed a small increase but was significantly decreased (P<0.05) after 4 weeks of HDS compared with that of CH rats. Daily water intake was increased (P<0.05) after 2 week in HDS rats but the overall changes of the rest period were no difference between both CH and HDS rats. White blood cell counts did not show any changes in both rat groups while red blood cell counts showed a decreas-ing trend after 4 weeks HDS. After HDS, hemoglobin concentration, hematocrit and mean corpuscular hemoglobin were significantly decreased (P<0.05) compared with CH rats. CONCLUSION: These results represent that the long-term HDS could attenuate the increase in body weight of young rats and induce the decrease in hemato-logical data, especially in the characteristics of red blood cell.
Animals ; Body Weight* ; Drinking* ; Erythrocyte Count ; Erythrocyte Indices ; Erythrocytes ; Hematocrit ; Hindlimb Suspension ; Humans ; Leukocyte Count ; Male ; Rats* ; Rats, Sprague-Dawley ; Water* ; Weightlessness

In the therapeutic or the nutritional aspects, Zn2+ has been used as a supplement in a variety of drugs. Most of divalent or trivalent cations affect ion channels in the cell membranes of various organs. In particular, Zn2+ has been regarded as a potassium (K+) channel blocker in the field of electrophysiology. ATP-sensitive K+ (KATP) channel, which is a kind of inward rectifier K+ channel, resides in the cell membrane of pancreatic beta cells and plays an important role in glucose-induced insulin secretion. The glucose increases intracellular ATP concentration, and this inhibits KATP channels. The inhibition of KATP channels activity depolarizes the cell, and subsequently, insulin is released by Ca2+ influx through the voltage- gated Ca2+ channels. Here, we demonstrate that KATP channels in the pancreatic beta cells are also the targets of extracellular Zn2+ blockade and its blockade is dependent on intracellular ATP concentration. This may be a compensatory mechanism preventing the oversecretion of insulin from the Pancreatic beta cells triggered by Zn2+ intake in a physiologically fasting condition.
Adenosine Triphosphate* ; Cations ; Cell Membrane ; Electrophysiology ; Fasting ; Glucose ; Insulin ; Insulin-Secreting Cells* ; Ion Channels ; KATP Channels* ; Potassium ; Potassium Channels, Inwardly Rectifying

BACKGROUND: Head-down suspension (HDS) of rats has been used as a model for simulation of a microgravity environment. C-type natriuretic peptides (CNP) and atrial natriuretic peptide (ANP) are produced in the central nervous system, especially in hypothalamus, to complement their peripheral natriuretic effects. Therefore, this study investigated the changes in the central adaptations of hypothalamic ANP and CNP syntheses to 4 weeks of HDS in rats. METHODS: Unanesthetized, unrestrained, male Sprague-Dawley rats were subjected to either a horizontal position (control rats) or a -45 degrees head-down tilt using the tail-traction technique (HDS rats). We determined the hypothalamic syntheses of natriuretic peptides as an expression of ANP and CNP mRNA. The expression of natriuretic peptide mRNA was measured by reverse transcription-polymerase chain reaction with [32P]-dCTP following 4 weeks of HDS in the hypothalamus of control and HDS rats. RESULTS: After 4 weeks of HDS, the expression of ANP mRNA showed a decreasing trend in the hypothalamus of HDS rats. In contrast with ANP, CNP mRNA expression was significantly (p<0.01) increased in the hypothalamus of HDS rats. There were different changes in the hypothalamic CNP and ANP mRNA expressions of HDS rats compared with that of the control rats.CONCLUSION: These results represent that the hypothalamic syntheses of natriuretic peptides are differently responded and the role of CNP is augmented to compensate for the decrement of ANP action in the central nervous system following 4 weeks of HDS.
Animals ; Atrial Natriuretic Factor ; Central Nervous System ; Complement System Proteins ; Head-Down Tilt ; Humans ; Hypothalamus ; Male ; Natriuretic Agents ; Natriuretic Peptides ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger* ; Weightlessness

OBJECTIVES: Manganese is cytotoxic to the central nervous system including basal ganglia. Its toxic mechanism is related to oxidative stress, mediated by toxic free radicals but is specultives. In the present study, we have investigated to manifest apoptosis in manganese-induced cytotoxicity in primary neuronal cell culture of rat basal ganglia. METHOD: To detect apoptotic neuronal cells were stained by the terminal deoxynu-cleotide(TdT)-mediated dUTP nick end-labelling(TUNEL) method and apoptotic changes in nuclei of neurons were observed by electron microscopy. RESULTS: We showed that TUNEL immunostain showed brownish signal in the nuclei of apoptotic cells and the proportions of apoptotic cells in Manganese treatment groups were more higher than controls. On transmission electron microscopy, there were chromatine condensation with margination toward nuclear membrane and condensation of cytoplasm in the treated with luM MnC1, for 48 hours in a basal ganglia neurons. Apoptotic bodies were found and consisted of semilunar-like condensed nuclei with relatively intact cytoplasmic organelles. CONCLUSIONS: Apoptosis appears to be one mechanism in the manganese-induced neuronal cell death. Manganese intoxication is a convenient model for apoptosis study.
Animals ; Apoptosis* ; Basal Ganglia* ; Cell Culture Techniques* ; Cell Death ; Central Nervous System ; Chromatin ; Cytoplasm ; Free Radicals ; In Situ Nick-End Labeling ; Manganese* ; Microscopy, Electron ; Microscopy, Electron, Transmission ; Neurons* ; Nuclear Envelope ; Organelles ; Oxidative Stress ; Rats

GABA (-aminobutyric acid) is one of the important neurotransmitters in the central nervous system of mammals and its action is variable according to the maturation phases of neurons. The neurons of early cultural days (less than 7 days) have been used for a developing neuronal model, while the neurons of later days (over 3 weeks) used for a mature model. This study was performed to investigate the electrophysiological property of GABAergic synapses in the hippocampal neurons cultured for 10 to 14 days which are considered to be transitional period between the developing and the mature phases. Membrane potential was depolarized and a inward transmembrane current was induced by 20 M GABA infusion. Frequency and amplitude of spontaneous postsynaptic currents (PSCs) were inhibited during the GABA infusion, but decay time constant was not affected significantly. In most hippocampal neurons, no GABAergic PSCs were observed during the administration of 0.5 M TTX, 50 M APV and 10 M CNQX. In the neurons counting 25% approximately, however, small persisted PSCs showed the existence of GABAergic synapses which were blocked by 10 M bicuculine. As the functional property of isolated GABAergic synapses, amplitude of GABAergic PSCs were diminished, and decay time constants and rising times were prolonged during the 20 M GABA infusion in all recorded neurons. In conclusion, approximately 25% of the hippocmpal neurons cultured 10 to 14 days used GABA as well as glutamate as a neurotransmitter. It seems that the GABAergic synapses composed of functionally homogenous GABAA receptors act as inhibitory modulator of the excitatory signal transmission.
6-Cyano-7-nitroquinoxaline-2,3-dione ; Animals ; Central Nervous System ; gamma-Aminobutyric Acid* ; Glutamic Acid ; Mammals ; Membrane Potentials ; Neurons* ; Neurotransmitter Agents ; Rats* ; Synapses ; Synaptic Potentials

BACKGROUND: This study was performed to evaluate the effects of a ProSeal laryngeal mask airway (PLMA) on intraoperative ventilation and blood pressure, and postoperative sore throat in laparoscopic cholecystectomy (LC). METHODS: Sixty, ASA 1 or 2 adults scheduled for elective LC were randomly allocated into two groups; i.e., endotracheal tube (ETT) or PLMA groups. General anesthesia was administered in the usual fashion. Blood pressure and heart rate were measured before and after the induction of anesthesia. Blood pressure, heart rate, peak inspiratory pressure (PIP) and end-tidal CO2 (ETCO2) also were measured before and after intraabdominal CO2 insufflation (pneumoperitoneum) at 5 minutes intervals over 30 minutes. Sore throat, nausea and vomiting were evaluated at 6 and 24 hours postoperatively. RESULTS: Blood pressure and heart rate were higher in the ETT group than in the PLMA group after induction (P < 0.05), however, no differences were observed during pneumoperitoneum. Following the induction of pneumoperitoneum, ETCO2 increased significantly, but without the group differences. PIP was less increased in the PLMA group. No significant differences were observed in incidences of postoperative sore throat, nausea or vomiting in the two groups. CONCLUSIONS: We conclude that PLMA is a useful alternative to ETT in LC. Furthermore, PLMA seems to be more useful for hypertensive patients.
Adult ; Anesthesia ; Anesthesia, General ; Blood Pressure* ; Cholecystectomy, Laparoscopic* ; Heart Rate ; Humans ; Incidence ; Insufflation ; Laryngeal Masks* ; Nausea ; Pharyngitis* ; Pneumoperitoneum ; Ventilation* ; Vomiting

No abstract available.
Lymphoma, Large-Cell, Anaplastic*

BACKGROUND: This prospective, double-blind randomized study was performed to compare the characteristics of recovery after general anesthesia induced by target-controlled propofol and sevoflurane. METHODS: Sixty, ASA class 1 or 2 female patients scheduled for an elective total abdominal hysterectomy were randomly allocated to two groups of 30; i.e. Propofol or Sevoflurane groups. General anesthesia was induced using propofol plus a fentanyl bolus (1 microgram/kg), and maintained with 66% nitrous oxide and either propofol infusion or sevoflurane inhalation. Anesthetic depth was controlled under bispectral index (BIS) monitoring: propofol and sevoflurane concentrations were adjusted to achieve target BIS values, and were between 40-60 during surgery and 60-70 during the final 15-20 minutes. The two anesthetic agents were discontinued following subcutaneous layer closure. After skin closure, the patients were ventilated manually with 100% oxygen until extubation. Patients were evaluated in terms of level of consciousness and side effects at the end of anesthesia and at 5, 15, 30 and 120 min after anesthesia. RESULTS: There were no significant differences in recovery times. The incidences of side effects were similar in the two groups, though the incidence of postoperative nausea was higher in the sevoflurane group. CONCLUSIONS: These results suggest that sevoflurane inhalation anesthesia has an emergence similar to that of propofol, except for a higher incidence of postoperative nausea.
Anesthesia* ; Anesthesia, General ; Anesthesia, Inhalation ; Anesthetics ; Consciousness ; Female ; Fentanyl ; Humans ; Hysterectomy ; Incidence ; Inhalation ; Nitrous Oxide ; Oxygen ; Postoperative Nausea and Vomiting ; Propofol* ; Prospective Studies ; Skin

Skip lesion is not uncommon feature in osteosarcoma and considered to be importantly associated with poor prognosis factor, and thus, should be excised with the main mass. The accurate pre-operative evaluation of the intramedullary extent of osteosarcoma is essential, because it determines the level of bone resection. Among the reliable detection methods, bone scan has a drawback of high rate of false negative results and regional MRI has a difficulty to cover the whole involved lesions without clinical suspicion. The authors report a case of osteosarcoma of the distal femur with a proximal skip lesion that was not detected by either regional MR imaging or by bone scan, but which was visualized by FDG-PET/CT.
Complement System Proteins ; Femur ; Neoplasm Metastasis ; Osteosarcoma ; Prognosis

BACKGROUND: Cyclin-dependent kinase (CDK) inhibitors are family of molecules that regulate the cell cycle. The CDKN2, a CDK4 inhibitor, also called p16, has been implicated in human tumorigenesis. The CDKN2 inhibits the cyclin/CDK complexes which regulate the transition from G1 to S phase of cell cycle. There is a previous report that homozygous deletion of CDKN2 region on chromosome 9p21 was detected frequently in astrocytoma, glioma and osteosarcoma, less frequently in lung cancer, leukemia and ovarian cancer, but not detected in colon cancer and neuroblastoma. However, little is known about the relationship between CDKN2 and laryngeal cancer. Therefore this study was initiated to investigate the role of CDKN2 in human laryngeal squamous cell carcinoma development. MATERIALS AND METHODS: We used 5 human laryngeal carcinoma cell lines whether they have deletions or losses of CDKN2 gene expression by DNA-PCR or RT-PCR, respectively. We examined 8 fresh frozen human laryngeal cancer tissues to detect the loss of heterozygosity (LOH) of CDKN2. PCR was performed by using microsatellite markers of short arm of human chromosome 9 (D9S126, D9S144, D9S156, D9S161, D9S162, D9S166, D9S171, D9S200 and D9SIFNA). For informative cases, allelic loss was scored if the signal of one allele was significantly decreased in tumor DNA when compared to the same allele in normal DNA. RESULTS: The CDKN2 DNA deletion was observed in 3 cell lines. The CDKN2 mRNA expression was observed in only one cell line, which was very weak. LOH was detected in 7 cases (87.5%). CONCLUSION: These results suggest that CDKN2 plays a role in the carcinogenesis of human laryngeal squamous cell carcinoma.
Alleles ; Arm ; Astrocytoma ; Carcinogenesis ; Carcinoma, Squamous Cell* ; Cell Cycle* ; Cell Line* ; Chromosomes, Human ; Colonic Neoplasms ; DNA ; Genes, p16* ; Glioma ; Head* ; Humans ; Laryngeal Neoplasms ; Leukemia ; Loss of Heterozygosity ; Lung Neoplasms ; Microsatellite Repeats ; Neck* ; Neuroblastoma ; Osteosarcoma ; Ovarian Neoplasms ; Phosphotransferases ; Polymerase Chain Reaction ; RNA, Messenger ; S Phase