Biomedical subjects

C C Tseng

Publications and source records attributed to C C Tseng.

At least 55 records · Page 3Linked to original sources

PubMed1998

Combination of bupivacaine scalp circuit infiltration with general anesthesia to control the hemodynamic response in craniotomy patients.

BACKGROUND: Sudden and overwhelming increases in blood pressure (BP) and heart rate (HR) during incision of the scalp may give rise to morbidity or mortality in patients with intracranial pathology undergoing neurosurgery. A modification of the method proposed by Labat to abate this circumstantiality was applied in a group of patients receiving craniotomy. The modified method was to combine scalp circuit infiltration of local anesthetic with general anesthesia to control the hemodynamic response to craniotomy. METHODS: Twenty-six patients scheduled to undergo craniotomy were randomly divided into two groups. Patients whose conditions or their current medication that might affect the stability of hemodynamics were excluded. In group A patients (N = 16) 25-30 ml of 0.25% bupivacaine was used for scalp circuit infiltration on the operation side, while in those of group B (N = 10) the same volume of 0.9% normal saline was used. After induction, anesthesia was maintained with 0.6% to 1.2% end-tidal isoflurane (ET-Iso) and 50% N2O in oxygen (N2O:O2 = 2 l/min:2 l/min). The end-tidal CO2 was kept within the range of 25-30 mmHg. BP and HR were recorded every five min before incision and then every two min after incision until one hour after induction. ET-Iso was also recorded every two min throughout a period of sixty min. If the BP and HR increased above 20% of the baseline (10 min before incision), thiopental 2.5 mg/kg and fentanyl 2 micrograms/kg were administered. If hypertension became sustained, the isoflurane concentration was adjusted until an acceptable level was obtained. RESULTS: The mean BP during the surgery was 92 +/- 1 mmHg in group A and 92 +/- 7 mmHg in group B. The difference in BP between incision to 6 min after incision was statistically significant (P < 0.05). The mean HR during surgery was 101 +/- 5 beats/min in group B and 91 +/- 2 beats/min in group A, the difference of which was not statistically significant. All of the patients in group B required a deepened anesthesia to keep the BP and HR within the normal range, but no patient in group A had such need. The average concentration of ET-Iso during the 60 min period was 0.95 +/- 0.12% in group B and 0.41 +/- 0.01% in group A, respectively. The difference was statistically significant (P < 0.05). CONCLUSIONS: Our results showed that scalp circuit infiltration with 0.25% bupivacaine significantly improved the cardiovascular stability and reduced the requirement of isoflurane during craniotomy. The routine use of bupivacaine scalp circuit infiltration in patients undergoing craniotomy should be considered.

Adult↗

PubMed1998

Oligodontia--a case report.

Oligodontia is defined as the congenital absence of six or more teeth, excluding the third molars. Genetic factors play an important role in oligodontia, which can occur as an isolated finding or as part of a syndrome. Characteristic dental symptoms are a reduced number of teeth, a reduction in tooth size, anomalies of tooth form, and delayed eruption. This article describes treatment of a 6-year-old girl with congenital absence of 16 permanent teeth. Her malocclusion was corrected by orthodontic therapy, and removable partial dentures were made to improve esthetics and chewing function.

Anodontia↗

PubMed1998

NitroG-L-arginine methyl ester decreases minimum alveolar concentration of isoflurane and reduces brain nitric oxide synthase activity in rats.

BACKGROUND: Nitric Oxide (NO), an endogenous messenger produced by the enzyme nitric oxide synthase (NOS), is recently introduced to be involved in inhalational anesthesia. We have previously reported that a specific NOS inhibitor, nitroG-L-arginine methyl ester (L-NAME), reduces the value of minimum alveolar concentration (MAC) for isoflurane anesthesia in rabbits. The purpose of this study is to evaluate the effects of the NOS inhibitor, L-NAME, on isoflurane MAC and NOS activity in rats. METHODS: Adult Wistar rats receiving isoflurane inhalation were randomly divided into two groups, with eight rats in each group. In the study group, L-NAME 30 mg/kg was given 60 min before the inhalation of isoflurane. Normal saline was given to the control group instead. The data of MAC, blood pressure (BP), and heart rate (HR) were recorded. The vital signs, such as EtCO2, PaO2, and temperature, were maintained within normal ranges. The activity of NOS in cerebellum was assessed by measuring the conversion of L-[3H] arginine to L-[3H] citrulline. All data were presented as mean +/- SD. Statistical analysis was performed using Student's t-test, where P < 0.05 was considered significant. RESULTS: In the presence of L-NAME (30 mg/kg), the MAC for isoflurane was markedly reduced from 1.6 +/- 0.20% (study group) to 1.0 +/- 0.09% (control group) (P < 0.05). The activity of cNOS in cerebellum was 220.09 +/- 23.64 (pmol/mg protein/30 min) in the control group, and in contrast a sharp reduction as low as to 115.40 +/- 24.85 (pmol/mg protein/30 min) was seen in the study group. CONCLUSIONS: The involvement of NO in the mechanism of isoflurane anesthesia can be demonstrated by the fact that the NOS inhibitor, L-NAME reduces the level of MAC and the cerebral NOS activity in rats.

Anesthetics, Inhalation↗

PubMed1997

Purification and partial amino acid sequence of a novel protein of the reticulocalbin family.

Binding proteins in neuronal membranes for a phospholipase A2 with presynaptic neurotoxicity have been purified. Three polypeptides of 87, 65, and 50 K Da were obtained from the synaptic membrane fraction of guinea pig brain utilizing an immobilized crotoxin (a phospholipase A2) column. For large scale purification, porcine brain was used instead, and two polypeptides of 50 and 18 K Da were found. The 65 and 18 K polypeptides may represent hitherto unidentified components of the crotoxin-binding proteins. Partial N-terminal amino acid sequence and a partial sequence for an internal peptide fragment have been determined for the 50 K polypeptide. Search of protein data bank reveals that this polypeptide or protein is a novel member of the reticulocalbin family of calcium-binding proteins.

Amino Acid Sequence↗

PubMed1997

Attenuation of the catecholamine responses by electroacupuncture on Jen-Chung point during postoperative recovery period in humans.

In this study, Jen-Chung (J-C) point was stimulated by electroacupuncture (EA) in 10 patients, and by placebo treatment in 10 controls, immediately after termination of inhalation for 15 min. During the postoperative recovery period, plasma catecholamine (CA) levels were assessed before (0) and 15 and 30 min after treatment. The time from cessation of inhalation to the first eye opening and to extubation did not differ between groups. The plasma catecholamine levels increased by 30% from 0 to 15 min in the control group but decreased by 6% in the EA group. The levels at 30 min were approximately the same as at time 0. The change in catecholamine levels from 0 to 15 min was significantly lower (P < 0.02) in the EA groups than the control group.

Acupuncture Points↗

PubMed1997

A point mutation in the glucose-dependent insulinotropic peptide receptor confers constitutive activity.

The glucose-dependent insulinotropic peptide receptor (GIP-R) is a member of the secretin and parathyroid hormone (PTH) family of seven transmembrane-spanning receptors. Point mutations of a histidine at the junction between the first intracellular loop and the second membrane-spanning domain and a threonine in the sixth membrane-spanning domain of the human PTH-receptor have been reported to be associated with constitutive activation of the PTH receptor in Jansen-type metaphyseal chondrodysplasia. In this study, we explored whether such mutations in the GIP-R might similarly induce constitutive, ligand-independent activation of the receptor. Single amino acid substitutions in the GIP receptor were made by site-directed mutagenesis and receptor binding and cAMP levels were measured in transfected human embryonal kidney cell line (L293). Mutation of the threonine at position 340 in the sixth transmembrane spanning domain to proline (T340P) led to agonist-independent constitutive activity and exhibited a four-fold increase in basal cAMP level as compared to the wild-type GIP-R. The increase in cAMP level in T340P mutant was proportional to the amount of transfected plasmid and corresponded to the receptor number on the cell surface. Despite its high basal cAMP level, the T340P mutant could be further stimulated by GIP, with maximal cAMP generation comparable to the wild-type receptor. The change of amino acid histidine at position 169 to arginine (H169R), however, behaved like the wild type receptor and did not possess constitutive activity. These results illustrate that a point mutation of threonine to proline at position 340 results in constitutive activation of the GIP receptor, without affecting its sensitivity to agonist stimulation.

Amino Acid Sequence↗

PubMed1997

Decreased production of nitric oxide by LPS-treated J774 macrophages in high-glucose medium.

We investigated the effect of high glucose levels on nitric oxide (NO) production by J774 macrophages treated with LPS. High concentrations of glucose inhibited the accumulation of nitrite, an indicator of NO production, and the steady state levels of inducible NO synthase mRNA were significantly reduced. While phorbol myrystate acetate mimicked the inhibition of NO production by glucose, the aldose reductase inhibitor ONO2235 did not alter NO production under normal or high glucose conditions. High glucose levels also prevented the increase in cellular levels of tetrahydrobiopterin, an essential cofactor of NO synthase. The reduction of inducible NO production by elevated glucose levels may therefore be involved in the pathophysiology of diabetes.

Aldehyde Reductase↗

PubMed1997

Mouth care for nasopharyngeal cancer patients undergoing radiotherapy.

A randomised trial was undertaken to compare the effect of three oral care protocols in delaying the onset of stomatitis and reducing oral injury in nasopharyngeal cancer patients undergoing radiotherapy, 30 eligible patients with a mean age of 56.2 years were recruited and evenly allocated to one of the three groups using a randomly permuted blocks method. Patients allocated to group E1 and group E2 were given the same instructions on oral care at 1 day, and 1 week before radiotherapy, respectively, while those allocated to the control group were given no instructions. We use the Oral Assessment Guide to assess the oral physical conditions of these patients daily. Our findings revealed that the patients in the E2 group not only had later onset of stomatitis than those in the control and the E1 groups, but also had lesser degree of oral injury measured by the overall assessment score. We thereby recommend the use of the E2 protocol for delaying the onset of stomatitis and reducing oral injury in nasopharyngeal cancer patients undergoing radiotherapy.

Adult↗

PubMed1997

Clinical application of transorotracheal tube tracheal insufflation of oxygen in patients undergoing simple video-assisted thoracoscopic surgery.

Video-assisted thoracoscopic surgery (VATS) has been performed during ganglionectomy and bullectomy and usually requires a collapsed or immobilized lung. Transtracheal insufflation of oxygen (TRIO) maintains an immobilized lung, adequate oxygenation, and partial CO2 elimination but has never been used for VATS. We have simplified the TRIO design with a catheter inserted through the lumen of the orotracheal tube in what we call "transorotracheal tube TRIO" (TRIO-TOTT) and investigated its clinical use on simple VATS. Eleven patients undergoing bullectomy for primary simple pneumothorax (PSP) were studied. During the performance of VATS, a 12-gauge suction catheter was inserted as our modification and connected to the gas outlet of an anesthetic machine. The flow rate of oxygen was maintained at 10 L/min. Blood gas was collected prior to TRIO-TOTT, during TRIO-TOTT at 5, 10, 15, and 20 min, and 5 min after TRIO-TOTT. The blood gas data showed excellent oxygenation while the PaCO2 increased at a rate of 1.2 mm Hg/min compared to 3-4 mm Hg/min for apnea oxygenation. After 20 min, the mean +/- SEM PaO2 and PaCO2 were 428 +/- 27 and 65.0 +/- 2.6 mm Hg, respectively. We conclude that TRIO-TOTT is a simple, safe, and effective ventilation method for simple VATS.

Adolescent↗

PubMed1997

Toothache with a multifactorial etiology: a case report.

A case report of orofacial pain originating from both dental and nondental conditions is presented. The spontaneous throbbing pain initiated from the left maxillary second premolar and spread throughout the entire upper part of the face to the frontoparietal area. Root canal treatment of the maxillary second premolar did not resolve the chief complaint. Magnetic resonance imaging examination revealed hypertrophy of the left inferior turbinate and soft tissue haziness in the left maxillary sinus floor. After antrostomy, submucosal turbinectomy, and endodontic treatment, the patient was free from pain. The final diagnosis of this case, in addition to pulpitis, was maxillary sinusitis with chronic rhinitis. The multiple factors associated with the etiology made the diagnosis difficult. The mechanism of referred pain from the maxillary sinus and paranasal mucosa to the maxillary teeth and face is discussed.

Chronic Disease↗

PubMed1997

Simultaneous team approach of a crown-lengthening procedure and an operative restoration: technique and long-term effect.

Traditionally, crown-lengthening procedures to expose subgingival caries for operative restorative work are carried out in a two-stage approach. A disadvantage of this procedure is that the gingival margin associated with the treated tooth moves apically; this may create an esthetic problem. Resin-modified glass-ionomer cement has been demonstrated to have good biocompatibility with dental hard and soft tissues. Surgical and restorative procedures were combined at the same appointment in an effort to achieve a restoration with minimal change in the gingival margin. Four patients have been treated with this one-stage team approach and followed for 8 to 13 months. The clinical results demonstrated this team approach procedure is excellent for the dentition when esthetics is a consideration.

Adult↗

PubMed1997

Ambulatory 24-hour esophageal manometry and pH-metry in patients with noncardiac chest pain, but no reflux symptoms.

The aim of this study is to determine the diagnostic value of 24-hour ambulatory esophageal manometry and pH-metry for patients with noncardiac chest pain (NCCP), but no reflux symptoms. Twenty-four hour ambulatory esophageal manometry and pH-metry was performed on 34 patients with NCCP, but no reflux symptoms. The pressure transducers were located 3, 8, and 13 cm above the lower esophageal sphincter (LES) and the pH probes were located 5 and 20 cm above the LES. An event marker was triggered by the patient for chest pain. Only 17 patients (50%) had at least one pain episode (total 81 episodes, range 1-19 episodes per person) during a 24-hour recording. Twenty-one chest pain episodes (26%) occurred during abnormal motility, whereas 4 episodes (5%) were associated with pH < 4, and 10 episodes (12%) had both abnormalities. The majority of chest pain episodes, 46 out of 81 events (57%), did not have any association with motility or pH abnormalities. Five of 7 patients (71%) with reflux-related chest pain and 8 of 11 patients (73%) with dysmotility-related chest pain had symptom association probability > 95%, indicating a significant association between chest pain and esophageal dysfunction. Our conclusion is that ambulatory esophageal manometry and pH-metry is a useful tool in the evaluation of NCCP, but only a few additional patients with reflux-related chest pain could be found in patients without reflux symptoms.

Adult↗

PubMed1997

NitroG-L-arginine methyl ester reduces the minimal alveolar concentration of isoflurane in rabbits.

BACKGROUND: Recently, some studies suggested that nitric oxide (NO) plays a role as a mediator in the central nociceptive pathways and is possibly involved the mechanisms of anesthesia and wakefulness. Inhibition of the L-arginine-NO pathway in the central nervous system may result in an anesthetic, analgesic, or sedative effect. The aim of the present study was to evaluate the effects of the nitric oxide synthase inhibitor (NOSI), nitroG-L-arginine methyl ester (L-NAME), on the threshold for isoflurane anesthesia in rabbits. METHODS: Sixteen New Zealand rabbits were randomly divided into two groups, with eight rabbits in each group. In the study group, a dose of L-NAME 30 mg/kg was injected i.v. daily as pretreatment on three consecutive days, and the fourth dose of L-NAME was given 30 min before the study began. Normal saline was given to the control group. Data of minimal alveolar concentration (MAC), blood pressure (BP), and heart rate (HR) were collected from both groups. Vital signs, such as EtCO2, O2 saturation, and temperature, were maintained within the normal range. All data were described as mean +/- SEM. Statistical analysis was performed using Student's t-test, where p < 0.05 was considered significant. RESULTS: MAC of isoflurane in the control group was 1.90 +/- 0.12%. MAC of the L-NAME group was 1.70 +/- 0.22%, significantly lower than the control group (p < 0.05). CONCLUSIONS: Our preliminary result shows that the MAC of isoflurane in animals treated with L-NAME was lower than that in the control group. It is suggested that inhibition of the nitric oxide pathway may enhance the effect of isoflurane.

Anesthetics, Inhalation↗

PubMed1996

Postprandial stimulation of insulin release by glucose-dependent insulinotropic polypeptide (GIP). Effect of a specific glucose-dependent insulinotropic polypeptide receptor antagonist in the rat.

Glucose-dependent insulinotropic polypeptide (GIP) is a 42-amino acid peptide produced by K cells of the mammalian proximal small intestine and is a potent stimulant of insulin release in the presence of hyperglycemia. However, its relative physiological importance as a postprandial insulinotropic agent is unknown. Using LGIPR2 cells stably transfected with rat GIP receptor cDNA, GIP (1-42) stimulation of cyclic adenosine monophosphate (cAMP) production was inhibited in a concentration-dependent manner by GIP (7-30)-NH2. Competition binding assays using stably transfected L293 cells demonstrated an IC50 for GIP receptor binding of 7 nmol/liter for GIP (1-42) and 200 nmol/liter for GIP (7-30)-NH2, whereas glucagonlike peptide-1 (GLP-1) binding to its receptor on ++betaTC3 cells was minimally displaced by GIP (7-30)-NH2. In fasted anesthetized rats, GIP (1-42) stimulated insulin release in a concentration-dependent manner, an effect abolished by the concomitant intraperitoneal administration of GIP (7-30)-NH2 (100 nmol/ kg). In contrast, glucose-, GLP-1-, and arginine-stimulated insulin release were not affected by GIP (7-30)-NH2. In separate experiments, GIP (7-30)-NH2 (100 nmol/kg) reduced postprandial insulin release in conscious rats by 72%. It is concluded that GIP (7-30)-NH2 is a GIP-specific receptor antagonist and that GIP plays a dominant role in mediating postprandial insulin release.

Animals↗

PubMed1996

Preliminary X-ray crystallographic analysis of human salivary cystatin.

Human salivary cystatin, a thiol proteinase inhibitor, has been implicated in potential antimicrobial and antiviral functions of saliva. A variant of human salivary cystatin SN expressed and purified in an Escherichia coli expression system lacking residues 12-16 near the N-terminus (Delta12-16) has been crystallized by the vapor-diffusion technique. The crystals are of the hexagonal space group P622 and have cell constants of a = 85.41, b = 85.41, c = 131.6 A, alpha = beta = 90, gamma = 120 degrees, and contain two molecules of molecular weight 13 500 per asymmetric unit. The crystals diffract up to a resolution of 2.2 A and are suitable for X-ray diffraction analysis.

Journal Article↗

PubMed1996

A new approach to the treatment of true-combined endodontic-periodontic lesions by the guided tissue regeneration technique.

Clinicians often have difficulty in the diagnosis and treatment of the combined endodontal and periodontal (endo-perio) lesion. A case of an endo-perio true-combined lesion on a maxillary premolar was first treated with conventional endodontic therapy. Periodontal surgery was then completed, which included scaling and root planing and apical curettage on the tooth. The facial bony defect was then filled with a decalcified freeze-dried bone allograft mixed with tetracycline powder. A non-resorbable Teflon membrane was then used to cover the bone material and the periodontal flap sutured over this. This combined treatment resulted in minimal probing depth (2 mm), maximal clinical attachment gain (8 mm), as well as radiographic evidence of alveolar bone gain. This case report demonstrates that proper diagnosis, followed by removal of etiological factors and utilizing the guided tissue regeneration technique combined with osseous grafting, will restore health and function to a tooth with severe attachment loss caused by an endo-perio lesion.

Adult↗

PubMed1996

Effect of cycloheximide on the expression of LPS-inducible iNOS, IFN-beta, and IRF-1 genes in J774 macrophages.

The effect of cycloheximide (CHX) on the gene expression for inducible NO synthase (iNOS), interferon (IFN)-beta, and IFN regulatory factor (IRF)-1 was examined in LPS-stimulated J774 macrophages. LPS caused increased expression of mRNAs specific for iNOS, IFN-beta, and IRF-1 with different kinetics. Addition of CHX resulted in inhibition of the LPS-induced iNOS gene expression and parallel decrease in NO production. In contrast, expression of IFN-beta and IRF-1 genes in response to LPS was potentiated in the presence of CHX. These results indicate that de novo protein synthesis is not required for IFN-beta and IRF-1 gene expression and that ongoing protein synthesis including IFN-beta and IRF-1 may be involved in the induction process of iNOS in mouse macrophages.

Animals↗

PubMed1996

Chronic desensitization of the glucose-dependent insulinotropic polypeptide receptor in diabetic rats.

Rats were rendered diabetic by streptozotocin, after which serum glucose-dependent insulinotropic polypeptide (GIP) levels, duodenal mucosal GIP content, and GIP mRNA levels were nine times, 50% and 80%, respectively, greater than in control rats. To determine whether an increase in GIP gene expression might induce chronic desensitization of its receptor, normal rats were subjected to continuous intravenous GIP infusion. Serum GIP levels increased gradually in GIP-infused rats, and by 4 h a threefold increase was detected. In response to GIP infusion, the serum insulin concentration increased at 30 min, followed by a gradual decrease, and at 4 h, no increase in insulin levels was detected despite a sustained elevated serum GIP level. The response to glucagon-like peptide-1 (GLP-1) was preserved, a reporter cell line (LGIPR2) stably transfected with rat GIP receptor cDNA was studied. GIP stimulated adenosine 3', 5'-cyclic monophosphate (cAMP) production in LGIPR2 cells, which was first detected after 1 h of stimulation, reached maximum level at 4 h, and returned to basal concentrations by 16 h. Additional stimulation with GIP at 16 h did not affect cAMP generation, indicating desensitization of the GIP receptor by the ligand. In contrast, a response to prostaglandin E1 or forskolin in GIP-desensitization was a receptor-specific process. The results of these studies indicate that GIP gene expression is enhanced in diabetic animals and that elevated serum GIP level induces chronic desensitization of the GIP receptor in vivo and in a stably transfected cell line.

Animals↗