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.

Helicobacter pylori-seronegative gastric carcinoma: a subset of gastric carcinoma with distinct clinicopathologic features

BACKGROUND/AIMS

The frequent association of gastric atrophy and intestinal metaplasia in gastric cancer (GC) might preclude serologic detection of Helicobacter pylori (H. pylori) infection in GC. By using polymerase chain reaction (PCR) for detection, we would like to determine whether there exists a subset of genuinely H. pylori-negative GC patients, and whether they have distinct clinicopathologic features or not.

METHODOLOGY

IgG antibodies against H. pylori were determined by ELISA in sera, and H. pylori DNA was detected by PCR in resected gastric specimens from 160 GC patients. Clinicopathologic characteristics were then compared among group A: seropositive, group B: seronegative but PCR-positive, and group C: seronegative and PCR-negative.

RESULTS

Among 160 patients, 105 (65.6%) were classified as group A, 25 (15.6%) as group B, and 30 (18.8%) as group C. Group B patients were older and had more infiltrative tumor growth than group A. Group C had a significantly higher frequency of female predominance, and their cancers were of a more cardiac location and of the diffuse histologic subtype than those of groups A and B.

CONCLUSIONS

A significant portion (15.6%) was negative to ELISA but positive to PCR, suggesting that older ages and infiltrative tumor growth might preclude serologic detection of H. pylori infection by impairing humoral responses. Although the majority (81.2%) has a strong association with H. pylori infection, an H. pylori-negative subset indeed exists and has distinct clinicopathologic features, supporting that causes other than H. pylori infection are involved in GC carcinogenesis.

Role of regulator of G protein signaling in desensitization of the glucose-dependent insulinotropic peptide receptor

The glucose-dependent insulinotropic peptide receptor (GIP-R) is a member of the G protein-coupled receptors. Recent studies have indicated that elevated serum GIP concentrations in type II diabetic patients might induce desensitization of the GIP-R, and this mechanism could contribute to impaired insulin secretion. The cellular and molecular mechanisms governing GIP desensitization are unknown. Here, we report the results of studies on a new family of proteins known as regulators of G protein signaling (RGS) that have been shown to mediate the desensitization process of other receptors. GIP-R and RGS1, -2, -3, and -4 complementary DNAs were cotransfected into human embryonic kidney cells (L293). GIP-stimulated cAMP generation in control cells and in those coexpressing RGS1, -3, and -4 displayed a dose-dependent increase 10 min after GIP treatment. In contrast, RGS2 expression inhibited the GIP-induced cAMP response by 50%, a response similar to that of cells desensitized by preincubation with 10(-7) M GIP. In betaTC3 cells, preincubation of GIP attenuated GIP-induced insulin release by 45% at 15 min and by 55% at 30 min. Expression of RGS2 in the betaTC3 cells significantly decreased GIP-stimulated insulin secretion, whereas glucose-induced insulin release was not affected. RGS2 messenger RNA was identified by Northern blot analysis to be expressed endogenously in betaTC3 and L293 cells, and its level was significantly induced by GIP treatment in betaTC3 cells. Moreover, RGS2 bound Gs alpha protein in an in vitro system, suggesting that RGS2 attenuated the Gs-adenylate cyclase signaling pathway. These results suggest a potential role for RGS2 in modulating GIP-mediated insulin secretion in pancreatic islet cells.

Dens invaginatus. Review of formation and morphology with 2 case reports

Dens invaginatus manifests itself with an aberrant morphologic character because of altered patterns of tooth formation. Presented in this article are 2 cases of dens invaginatus in maxillary lateral incisors that were successfully treated nonsurgically. In the first case, a circular main canal was clearly observed surrounding the invaginated canal. The involved tooth in the second case responded to electric pulp testing, though a periapical radiolucency was evident; root canal treatment of the invaginated canal failed to resolve the pathosis. Debridement of both the main canal and the invaginated canal produced resolution. The complex morphologic nature of these root canal systems and the close relationship between the invaginated and main canals is demonstrated and discussed.

The small subunit ribosomal RNA gene sequence of Pleistophora anguillarum and the use of PCR primers for diagnostic detection of the parasite

Using the polymerase chain reaction (PCR) and two primers for conserved regions of the small subunit ribosomal RNA (SSU-rRNA) of Microsporidia, a DNA segment about 1,195 base pairs long was amplified from a DNA template prepared from purified spores of the microsporidian species Pleistophora anguillarum. These spores had been isolated from adult eels (Anguilla japonica) with "Beko Disease." A comparison of sequence data from other microsporidian species showed P. anguillarum SSU-rRNA to be most similar to Vavraia oncoperae. When juvenile eels were artificially infected with P. anguillarum, enzyme-linked immunosorbent assay could detect a positive infection only 12 days post-infection. However, when suitable PCR primers were used, a DNA fragment of about 0.8 kb was detected from these juvenile eels after only 3 days post infection. No PCR product was obtained with templates prepared from clinically healthy control animals.

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.

A requirement for ARF6 in Fcgamma receptor-mediated phagocytosis in macrophages

Phagocytosis requires extension of F-actin-rich pseudopods and is accompanied by membrane fusion events. Members of the ARF family of GTPases are essential for many aspects of membrane trafficking. To test a role for this family of proteins in Fcgamma receptor-mediated phagocytosis, we utilized the fungal metabolite brefeldin A (BFA). The addition of 100 microM BFA to a subclone of RAW 264.7 macrophages disrupted the appearance and function of the Golgi apparatus as indicated by altered immunofluorescent distribution of beta-COP and reduced efflux of BODIPY C5-ceramide, a phospholipid that normally accumulates in the Golgi apparatus. In contrast, BFA had no effect on phagocytosis of IgG-coated erythrocytes. These results suggested that activation of BFA-sensitive ARFs is not required for phagocytosis. ARF6 is unique among members of the ARF family in that its membrane association is unaffected by BFA. Expression of ARF6 mutants defective in either GTP hydrolysis (Q67L) or binding (T27N) inhibited phagocytosis of IgG-coated erythrocytes and attenuated the focal accumulation of F-actin beneath the test particles. These results indicate a requirement for ARF6 in Fcgamma receptor-mediated phagocytosis and suggest that ARF6 is an important mediator of cytoskeletal alterations after Fcgamma receptor activation.

The cysteine of the cytoplasmic tail of glucose-dependent insulinotropic peptide receptor mediates its chronic desensitization and down-regulation

The glucose-dependent insulinotropic peptide receptor (GIP-R) is a member of G-protein-coupled, seven transmembrane-spanning receptors. Recent studies have shown that elevated serum GIP level in diabetic patients may induce chronic desensitization of the GIP-R, and that this mechanism could contribute to impaired insulin secretion. The cellular basis of down-regulation and chronic desensitization of GIP-R is unclear. To explore the role of the carboxyl terminus of the GIP-R in mediating these processes, five truncated GIP-Rs (T395, T399, T420, T431, T455) were created to delete consecutive serines from the carboxyl end. All mutants except T395 exhibit an identical ligand-binding affinity to the WT receptor. The T395 mutant, which had the entire carboxyl tail removed, does not bind to ligand. Down-regulation and desensitization was assessed by measuring the receptor number and the ability of agonist-induced cAMP or [Ca2+] generation after pre-exposure to 10(-7) M GIP for 24 h. The wild-type (WT) and T421, T431, T455 mutant GIP-Rs are maximally down-regulated by GIP preincubation, whereas T399 mutant does not, indicating that the sequence between amino acids 399 and 420 is critical for this process. Mutation analysis of this area by alanine scanning mutagenesis reveals two critical residues: serine 406 and cysteine 411. Replacement of serine 406 with arginine (S406R) or alanine (S406A) partly attenuates agonist-induced down-regulation and desensitization. In contrast, mutation of the cysteine 411 to glycine (C411G) or alanine (C411A) markedly attenuates both processes. Mutant SCRG, in which both serine 406 and cysteine 411 are mutated, behaves similar to C411G or C4111A. The data suggest that chronic desensitization and down-regulation of the GIP-R may be mediated by similar mechanisms, and that the cysteine in the carboxyl terminus plays an essential role in regulating both processes.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Shortening and superlon-wrapping the downstream tube can increase the useful range of the blood warmer

BACKGROUND

Hypothermia occurs frequently in clinical anesthesia. Many apparatus were introduced to keep intravenous fluid warm. But at low to medium flow rates little effects have been achieved because of heat lost along the tube. Superlon, an industrial heat-preserving material widely used in air conditioning to prevent temperature change, has never been used in the blood warmer.

METHODS

The study was performed in three groups group I using standard (120 cm) unwrapped tube (Animac AM-4 set), group II using a shortened downstream tube (60 cm), and group III using the downstream tube which was further wrapped with superlon (Super LTD). The blood warmer used was identical in all 3 groups. We recorded the fluid temperatures at different points downstream at various flow rates. The values were then compared among groups.

RESULTS

The fluid temperatures before entering the warmer were around 20 degrees C and 37 degrees C at the 2 cm post-warmer points at various flow rates. The end point temperatures rose with flow rates and were the highest in group III and lowest in group I at each flow rate (p < 0.01). In group III the temperature could be kept above 32 degrees C at a very low flow rate (150 ml/h) and above 35 degrees C at 300 ml/h. In group I, 1,000 to 2,000 ml/h were needed to keep the same temperature.

CONCLUSIONS

These refinements increase the useful range of the Animac AM-4 warmer and make it useful in pediatric rapid fluid resuscitation and current fluid management. Moreover, they are easy to set up, inexpensive, and can be applied to any kind of blood warmers.

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.

[Post-obstructive pulmonary edema following extubation--report of two cases]

Pulmonary edema may develop in healthy patients after anesthesia. It usually results from upper airway obstruction which may be caused by laryngospasm or aspiration. Increased inspiratory effort following airway obstruction significantly produces negative intrathoracic pressure that may lead to pulmonary edema. We reported two cases of post-obstructive pulmonary edema following extubation. They were essentially healthy young males, one of whom received urethroplasty and the other received pulmonary blebectomy. Their hemodynamic and ventilatory conditions had been kept stable during surgery. Upper airway obstruction followed by pulmonary edema developed immediately after extubation, which was successfully treated without any sequelae.

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.

Changes of propofol levels in isolated cardiopulmonary bypass circuit

BACKGROUND

High dose fentanyl anesthesia in cardiac surgery has been supplemented with propofol to prevent patient's awareness and recall. It has been known that during cardiopulmonary bypass (CPB), fentanyl or midazolam concentration decreases, except for propofol where it remains unknown. This study evaluated the interaction between propofol and the CPB circuit in vitro.

METHODS

Three identical experiments were conducted. In each experiment we used a set of CPB circuit composed of a standard 3/8 inch PVC tubing trap, a reservoir and a pump. The reservoir was primed with 2,000 ml solution of 2.5% dextrose and 0.45% NaCl in which 20 mg propofol was added. The solution was circulated in the circuit at a flow rate of 2 L/min. The experimental period was 30 min. A 5 ml sample of the solution was taken from the venous sampling site of the circuit immediately prior to the experiment, and thereafter each from the arterial and venous sampling sites at 1, 3, 5, 10, 20 and 30 min after the start of the experiment. The samples were kept at 4 degrees C and assayed by HPLC.

RESULTS

The propofol concentrations decreased exponentially with the increase of experimental time. There were no significant differences in the concentrations and the rates of decrease between the arterial sampling site and the venous sampling site. The decrease was 20% at 1 min, 68% at 10 min, 83% at 20 min, and 92% at 30 min after the beginning of the experiment.

CONCLUSIONS

The results demonstrate the presence of propofol sequestration by the CPB circuit. Evaporation in the bubble oxygenator, absorption by and/or adherence to the circuit are suspected as the possible causative factors.

Verruciform xanthoma. Case report and literature review

Verruciform xanthoma is a relatively uncommon lesion. Half of the reported cases occurred in the gingiva or alveolar ridge. In most cases, the clinical impressions are papilloma or verrucous carcinoma, which demonstrates the importance of the clinical and pathological recognition of this lesion. The cause of pathogenesis is still unknown since the first report in 1971. There are some cases reported in conjunction with leukoplakia, carcinoma in situ, pemphigus, and discoid lupus erythematosus (DLE), which merits close evaluation of this disease. This article reports two cases of verruciform xanthoma and reviews the evidence of its pathogenesis from the available literature.

A parallel decoding algorithm for IFS codes without transient behavior

Iterated function systems (IFSs) have received great attention in encoding and decoding fractal images. Barnsley (1988) has shown that IFSs for image compression can achieve a very high compression ratio for a single image. However, the major drawback of such a technique is the large computation load required to both encode and decode a fractal image. We provide a novel algorithm to decode IFS codes. The main features of this algorithm are that it is very suitable for parallel implementation and has no transient behavior. Also, from the decoding process of this method we can understand the encoding procedure explicitly. One example is illustrated to demonstrate the quality of its performance.

Decrease of anesthetics activity by electroacupuncture on Jen-Chung point in rabbits

The effect of acupuncture at life-saving point on the central nervous depressive action of anesthetics was investigated in rabbits. Stimulation with electroacupuncture (EA) inserted in Jen-Chung point, which is located at the mid-point on the upper lip, decreased the sleeping time induced by pentobarbital or propofol. However, this action of acupuncture was not modified by naloxone at the doses sufficient to block opiate receptors. Plasma beta-endorphin detected by radioimmunoassay was also not markedly changed in rabbits which received similar electrostimulation. Moreover, pretreatment with para-chlorophenylalanine at a dose sufficient to deplete endogenous 5-hydroxytryptamine (5-HT) failed to influence the action of EA. Mediation of endogenous opioids and/or 5-HT in this action of EA was then ruled out. Prazosin reversed the sleeping time decreasing action of acupuncture in a dose-dependent manner. Also, the action of acupuncture was eliminated in rabbits which received intracerebroventricular injection of guanethidine at a dose which could block noradrenergic nerve terminals. It is suggested that stimulation of Jen-Chung point through EA can activate noradrenergic neurotransmission in the brain, which in turn reduces the central nervous depressive activity of anesthetics.

Glucose-dependent insulinotropic peptide (GIP) gene expression in the rat salivary gland

Previous studies have indicated that following nutrient ingestion, GIP is released principally from the upper small intestine. In addition to its presence in the rat small intestine, GIP transcripts have also been localized to the submandibular salivary gland (SSG). The present studies were directed to further characterize expression of the GIP gene in the SSG. Pregnant rats were sacrificed at gestational days 18 and 20, followed by the removal of rat fetuses. The duodenum pancreas, and SSG were then excised from the fetuses, as well as from neonatal pups at ages 1, 3, 7, 10, 14, and 21 days. RNA was extracted and measured by Northern blot analysis using specific rat GIP probes. GIP transcripts were first detected in the duodenum in the 18-day fetus and reached maximum levels at birth. In contrast, GIP mRNA was not observed in the SSG until 10 days postnatally and was not detected at all in either the fetal or neonatal pancreas. In situ hybridization of the SSG using an 35S-labelled antisense GIP RNA probe demonstrated expression of the GIP gene to be limited to ductal cells, with no transcripts present in acini. In separate experiments, rats fasted overnight were given water or 10% glucose. While no changes were detected in water-fed rats following oral glucose ingestion, small, but significant increases in SSG GIP gene expression were detected at 60 and 240 min. The results of these initial studies suggest the possibility of a functional role for GIP in the rat salivary gland by the demonstration of GIP mRNA in the SSG by Northern analysis and in situ hybridization, as well as by an increase in SSG GIP gene expression following a glucose meal.

Elimination of AC interference in electrocardiogram using IIR notch filter with transient suppression

In this paper, a technique for suppressing the transient states of IIR notch filter is investigated. This technique uses the vector projection to find better initial values for notch filters. When a notch or comb filter is used to eliminate power line (AC) interference in the recording of electrocardiograms (ECG), the performance of the notch filter with transient suppression is better than that of the conventional notch filter with arbitrary initial condition. The improvements with this technique are at the cost of additional computation load at the beginning of filtering.

Correction of a large periradicular lesion and mucosal defect using combined endodontic and periodontal therapy: a case report

The successful treatment of a large endodontically induced periradicular defect and soft tissue fenestration by combined endodontic and periodontal therapy is described. Endodontics was performed on the mandibular left central incisor, the apex was resected, and a retrograde amalgam was placed. The defect was thoroughly debrided and the exposed root surface was planed with curettes. Demineralized freeze-dried bone allograft and a nonresorbable membrane were placed over the defect and the exposed root surface. The membrane was removed in 6 months and there appeared to be bone regeneration with complete closure of the soft tissue fenestration. Endodontic therapy in combination with guided tissue regeneration and bone grafting may provide another modality of treatment for endodontically related hard and soft tissue defects.

[Changes of arterial oxygen tension in supine position during one-lung anesthesia]

BACKGROUND

One-lung ventilation during anesthesia (one-lung anesthesia) in patients under lateral decubitus position to help performing intra-thoracic surgical procedures was well known to have larger alveolar-to-arterial oxygen tension difference and lower arterial oxygen tension (PaO2) as compared to two-lung ventilation. In the present study, we investigate the changes of arterial oxygen tension in the supine position during one-lung anesthesia.

METHODS

Forty-two patients of palmar hyperhidrosis, ASA class I-II, scheduled to receive bilateral transthoracic endoscopic sympathectomy were studied. After anesthetic induction (fentanyl, thiopental, and succinylcholine), a 35 (for female) or 37 (for male) French left-sided Robertshaw double-lumen endobronchial tube was intubated. Anesthesia was maintained with isoflurane 1.0-1.5% and 50% O2-N2O. They were changed to isoflurane 1.5-2.0% and 100% O2 during one-lung ventilation. Once the surgical operation is completed, they were changed to 100% O2 and two-lung ventilation. Arterial blood gases were measured at 4 phases: 5 min after endobronchial intubation (two-lung ventilation), 5 min after left one-lung ventilation, 5 min after right one-lung ventilation, and 5 min after accomplishing operation (two-lung ventilation).

RESULTS

The results showed PaO2 were significantly lower in left and right one-lung ventilation with 100% O2 as compared with that obtained from two-lung ventilation with 50% O2 5 min after endobronchial intubation (p < 0.05). Furthermore, right one-lung ventilation had a lower PaO2 than left one-lung ventilation (p < 0.05).

CONCLUSIONS

We conclude that arterial oxygen tension can be safely maintained during one-lung anesthesia with pure oxygen in healthy patients lying in a supine position.

Binding proteins on synaptic membranes for crotoxin and taipoxin, two phospholipases A2 with neurotoxicity

Crotoxin and taipoxin are both neurotoxic phospholipases A2 capable of affecting the presynaptic activity to bring about ultimate blockade of synaptic transmission. The enzymatic activity has generally been considered to be necessary but not sufficient for the blockade. Since many phospholipases A2 with comparable or even higher enzymatic activity are not toxic, it has been postulated that the difference lies in the affinity of binding to the presynaptic membrane. In confirmation of this proposition, we and others have previously shown that iodinated crotoxin and taipoxin bind specifically with high affinity to the isolated synaptic membrane fraction from guinea-pig brain, whereas specific binding is not detected with the nontoxic pancreatic phospholipase A2. Experiments based on photoaffinity labeling and simple chemical cross-linking techniques have led to the identification of three polypeptides preferentially present in neuronal membranes as (subunits of) the binding protein(s) for crotoxin and/or taipoxin. Some, but not all, other toxic phospholipases A2 also appear to be ligands for the three polypeptides. We now report studies on partial purification of these polypeptides using affinity chromatography and other techniques. In order to learn the normal physiological roles played by the toxin-binding proteins, the phospholipase-independent effects of the toxins on the synaptosomes have been sought. We have found that under Ca(2+)-free condition, taipoxin or crotoxin inhibits with IC50 of 20-1000 nM the Na(+)-dependent uptake of norepinephrine, dopamine and serotonin by the synaptosomes. In contrast, choline uptake is not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Different growth control of the two human thyroid cell lines of adenomatous goiter and papillary carcinoma

To study the growth control of human thyroid cells in different stages of differentiation, we established two human thyroid cell lines of adenomatous goiter and papillary carcinoma. A 59-year-old female patient with adenomatous goiter was operated in September 1991, and a 27-year-old female patient with papillary carcinoma in May 1990. The thyroid cell lines were established by successive passage without cellular or genetic manipulations such as fusing other cell lines or oncogenic viral infection. These cell lines, human adenomatous goiter cells (hAG) and human papillary thyroid carcinoma cells (hPTC), exhibited a flattened polygonal shape and proliferated as a monolayer in cell culture. The doubling time of the hAG cells was 60 h in Ham's F12 medium supplemented with 10% fetal bovine serum, and that of the hPTC cells, 18 h in the same medium. Both cell lines expressed mRNA for TSH receptor and secreted cAMP into the medium during incubation with thyrotropin (TSH) at concentrations as low as 0.01 mU/mL. The effects of activators of protein kinase A (PKA), protein kinase C (PKC), tyrosine kinase (TK), and estradiol (E2) on proliferation of the hAG cells and the hPTC cells were assessed by measuring cellular DNA content in 24-well plates with diaminobenzoic acid. TSH stimulated proliferation of the hAG cells, but it inhibited proliferation of the hPTC cells. Since TSH activates two signaling pathways, the adenyl cyclase-PKA system and phospholipase C-PKC system, we tested effects of dibutylyl cAMP (dBC) and phorbol myristate 13-acetate (PMA), separately. dBC stimulated proliferation of the hAG cells, but it inhibited that of the hPTC cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Wavelet transform and scale space filtering of fractal images

In this correspondence, we consider wavelet transform and scale space filtering as special cases of general scale shift mapping (SSM). Then, the SSM is used as a tool for characterizing the geometrical complexity of uniform fractals. This tool can reveal the construction rule of fractals and estimate fractal dimension. Finally, we use the results obtained from scale shift mapping to estimate iterated function system (IFS) codes of a class of fractal images. Some examples have been illustrated to demonstrate its good performance.

Sclerotherapy on liver cirrhosis with esophageal variceal bleeding: eight years of experience

BACKGROUND

Patients with liver cirrhosis usually die of hepatic failure and variceal bleeding. Successful treatment of the latter can reduce mortality. Sclerotherapy is one method often used. This study compared (a) the successful rate of acute bleeding control; (b) short- and long-term survival rate between those with and without treatment with sclerotherapy to evaluate the clinical benefit of sclerotherapy for liver cirrhosis patients with esophageal variceal bleeding.

METHODS

Between August 1983 and December 1991, 183 cirrhotic patients with esophageal variceal bleeding receiving endoscopic injection sclerotherapy (EIS) was compared with 123 patients without sclerotherapy treatment retrospectively. The severity of underlying liver disease was classified using a modified Child's classification. Sclerotherapy was done within 48 hours after active bleeding in the sclerotherapy-treated group, while the medical treatment group received Sengstaken-Blakemore (SB) tube or pitressin infusion only.

RESULTS

Successful rate of acute bleeding control was 81.63% (120/147) in the EIS group and 59.35% (73/123) in the medical treatment group. The worse the hepatic function of the patients, the lower the success of acute bleeding control in both groups. Fifty subjects (74.63%) had varices eradicated in 67 sclerotherapy treatment patients with regular follow-up. Patients receiving EIS had a better long-term survival than those without treatment. Benefit of EIS on long-term survival was more significant in Child B patients and less in Child C and Child A patients. Death from variceal bleeding was lower in the EIS group than in the medical treatment group (32% vs 62.6%). Complications of EIS were rare. Eight patients died of aspiration pneumonia, spontaneous bacterial peritonitis or acute renal failure after sclerotherapy, and most were Child B and C patients. Sixteen patients had esophageal stricture. Four needed dilatation treatment.

CONCLUSIONS

The sclerotherapy-treated group had a higher control rate of acute bleeding and lower mortality rate from esophageal variceal bleeding compared with the medical-treated group. The procedure prolonged long-term survival in Child B patients but did so less frequently in Child A and Child C patients. The incidence of complications was low. As a whole, EIS is a safe and efficient method for control of esophageal variceal bleeding.

Anticancer chemosensitivity profile of freshly separated human pancreatic cancer cells assessed by DNA synthesis inhibition assay

The chemosensitivity of 49 freshly separated human pancreatic cancers to seven kinds of anticancer agents were assessed by a DNA synthesis (3H-thymidine incorporation) inhibition assay. DNA synthesis is higher in involved lymph nodes (n = 7), malignant effusion (n = 15), liver metastasis (n = 7), primary cancer (n = 15), and skin metastasis (n = 5). Chemosensitivity assay demonstrates that etoposide, 4-epirubicin, carboquone, and 5-fluorouracil are more effective than cisplatin, mitomycin-C, and Adriamycin. In general, metastatic lesions of pancreatic cancer tend to show higher chemosensitivity than primary lesions. Pathological analysis demonstrates that small primary pancreatic cancers tend to be more responsive than large primary cancers, and primary pancreatic cancers with no regional lymph node involvement also tend to be more responsive than those with nodal involvement. No significant differences are seen in terms of tumor spread, vascular involvement, sex of patient, and histological type. When chemosensitivity assay is not available, the results of the present study may be beneficial to choose the regimens.

Functional complementation of the adenovirus E1B 19-kilodalton protein with Bcl-2 in the inhibition of apoptosis in infected cells

Expression of the adenovirus E1A oncogene induces apoptosis which impedes both the transformation of primary rodent cells and productive adenovirus infection of human cells. Coexpression of E1A with the E1B 19,000-molecular-weight protein (19K protein) or the Bcl-2 protein, both of which have antiapoptotic activity, is necessary for efficient transformation. Induction of apoptosis by E1A in rodent cells is mediated by the p53 tumor suppressor gene, and both the E1B 19K protein and the Bcl-2 protein can overcome this p53-dependent apoptosis. The functional similarity between Bcl-2 and the E1B 19K protein suggested that they may act by similar mechanisms and that Bcl-2 may complement the requirement for E1B 19K expression during productive infection. Infection of human HeLa cells with E1B 19K loss-of-function mutant adenovirus produces apoptosis characterized by enhanced cytopathic effects (cyt phenotype) and degradation of host cell chromosomal DNA and viral DNA (deg phenotype). Failure to inhibit apoptosis results in premature host cell death, which impairs virus yield. HeLa cells express extremely low levels of p53 because of expression of human papillomavirus E6 protein. Levels of p53 were substantially increased by E1A expression during adenovirus infection. Therefore, E1A may induce apoptosis by overriding the E6-induced degradation of p53 and promoting p53 accumulation. Stable Bcl-2 overexpression in HeLa cells infected with the E1B 19K- mutant adenovirus blocked the induction of the cyt and deg phenotypes. Expression of Bcl-2 in HeLa cells also conferred resistance to apoptosis mediated by tumor necrosis factor alpha and Fas antigen, which is also an established function of the E1B 19K protein. A comparison of the amino acid sequences of Bcl-2 family members and that of the E1B 19K protein indicated that there was limited amino acid sequence homology between the central conserved domains of E1B 19K and Bcl-2. This domain of the E1B 19K protein is important in transformation and regulation of apoptosis, as determined by mutational analysis. The limited sequence homology and functional equivalency provided further evidence that the Bcl-2 and E1B 19K proteins may possess related mechanisms of action and that the E1B 19K protein may be the adenovirus equivalent of the cellular Bcl-2 protein.

Sclerotherapy for esophageal variceal bleeding in advanced hepatocellular carcinoma: an 8-year experience in Taiwan

Between August 1983 and December 1991 at the Taichung Veterans General Hospital, Taiwan, 65 advanced hepatocellular carcinoma (HCC) patients with esophageal variceal bleeding received endoscopic injection sclerotherapy (EIS) and 60 such patients received conservative medical treatment without EIS. The rate of successful control of acute bleeding was 72.5% (27/40 patients) in the EIS group and 56.7% (34/60 patients) in the non-EIS group. The rebleeding rate was lower in the EIS group than in the non-EIS group (26.9% vs 73.5%). Thirty-one of the EIS and 44 of the non-EIS treatment patients, mainly Child's B and C patients, died within 2 months after the first bleeding. In the short term, EIS decreased the mortality due to esophageal variceal bleeding, but the survivors still had to face hepatic failure and tumor growth. Thus, benefits of EIS were noted on short- but not on long-term survival. The mean survival times were 2.38 months for the EIS group and 1.79 months for the non-EIS group. Since EIS had no beneficial effects on long-term survival it is doubtful whether sclerotherapy applied to esophageal variceal bleeding in patients with advanced HCC would be worthwhile, as the endoscopic procedure would only add to their suffering.

Gene expression of tumor necrosis factor alpha and interferon gamma in the lungs of Mycoplasma pulmonis-infected mice

ICR mice were infected intranasally with Mycoplasma pulmonis isolated freshly from the lungs of a rat with pneumonia. We demonstrated with high reproducibility the expressions of messenger RNAs of cytokines, tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) in the lung tissue of M. pulmonis-infected mice by the reverse transcriptase-polymerase chain reaction and confirmed specific mRNA of the cytokines by restriction endonuclease digestion. Both the viable population of M. pulmonis in the lung tissue and the titers of the neutralizing antibody in the serum increased between 7 and 21 days, and reached their maximum 35 days after infection. The pneumonia in mice progresses with the development of lung lesions after 7 days of infection. The early lesions are characterized primarily by neutrophils and edema in the alveolar spaces. mRNAs prepared from the lung tissue of M. pulmonis-infected and -uninfected mice were also tested for the presence of messages specific to TNF alpha and IFN gamma by the reverse transcriptase-polymerase chain reaction. The expression of the genes encoding TNF alpha and IFN gamma was constitutively demonstrated from 24 hr through 35 days after the intranasal inoculation of M. pulmonis. Furthermore, cells of two types, adherent and nonadherent cells, in bronchoalveolar lavage fluids obtained from the mice 3 weeks after inoculation of M. pulmonis were also found to express the genes of TNF alpha and IFN gamma respectively. These data suggest that these cytokines would play a role in both stimulation in the development of pathological changes in mycoplasmal infection, affecting the inflammatory responses.

Rat cluster of differentiation 1 molecule: expression on the surface of intestinal epithelial cells and hepatocytes

BACKGROUND/AIMS

Cluster of differentiation 1 (CD1) is a family of nonpolymorphic, major histocompatibility complex class I-like molecules with prominent expression in the liver and intestinal epithelium of humans and mice. Models of intestinal and hepatobiliary inflammation and experimental liver transplantation are conducted in the rat, yet nothing is known of CD1 expression in this species.

METHODS

Monoclonal antibodies against murine CD1 were used to identify a rat CD1 homologue. Tissue messenger RNA expression was confirmed by Northern blot analysis with a murine CD1 complementary DNA probe.

RESULTS

Immunoperoxidase staining detected CD1 in intestinal epithelial and liver cells but not in the thymus. Immunofluorescence of isolated hepatocytes and a rat fetal intestinal cell line, SLC-44, showed cell surface expression of CD1. Metabolic labeling and immunoprecipitation of the SLC-44 cell line and a mouse intestinal epithelial cell line, MODE-K, showed a protein of 55 kilodaltons. Immunoblotting of CD1 in isolated intestinal epithelial cells and hepatocytes showed a molecule of 55 kilodaltons. Northern blot analysis showed a single message of approximately 2.2 kilobases in hepatocytes.

CONCLUSIONS

A CD1 homologue exists in the rat. Expression in the rat intestine and liver are similar to those in the human and mouse. The rat may be useful as a model for the study of CD1 function.

Regulation of glucose-dependent insulinotropic peptide gene expression by a glucose meal

Glucose-dependent insulinotropic peptide (GIP) enhances insulin secretion by pancreatic beta-islet cells. Its release has been demonstrated predominantly after the ingestion of carbohydrate and fat. We have recently cloned a rat intestinal GIP cDNA and in the present studies have used this cDNA as a probe for measuring rat duodenal GIP mRNA after nutrient administration. Rats were fasted overnight, after which they were permitted to drink water or 10% glucose. The duodenum was then removed, GIP mRNA was measured by Northern hybridization analysis, and duodenal mucosa and serum GIP levels were determined by radioimmunoassay. In response to oral 10% glucose, duodenal mucosal GIP mRNA concentrations increased from 2 to 4 h, and at the end of 4 h a threefold increase was detected. Serum and mucosal GIP concentrations increased earlier, starting at 60 min, and levels remained elevated at 4 h. In separate studies, nuclear run-on assays were performed to compare the effects of glucose and water ingestion on transcription of the GIP gene. Whereas no increase in GIP gene transcription was detected in rats ingesting water, the rate of transcription doubled in glucose-fed rats. Actin gene transcription was nearly identical in both groups, indicating genomic specificity. The results of these studies indicate that duodenal GIP gene expression is stimulated at both the pre- and posttranslational levels by glucose-containing meals. These studies further suggest that the release of GIP from cellular storage granules might account for the initial increase in serum GIP levels after oral glucose ingestion.

Cocaine toxicity and the calcium channel blockers nifedipine and nimodipine in rats

Two dihydropyridine type calcium channel blockers (CCBs) were studied for any protective or therapeutic effect upon cocaine-induced toxicity and death in rats. To test for the protective effects, rats were pretreated with vehicle (control), nifedipine or nimodipine, intraperitoneally (IP) 30 minutes prior to an LD85 of cocaine, or intravenously (IV) 10 minutes prior to cocaine administration. Animals receiving IP control vehicle developed seizures in 5.6 +/- 1.0 minutes and respiratory arrest in 9.8 +/- 1.4 minutes. Animals pretreated IP with nifedipine or nimodipine developed seizures and respiratory arrest significantly sooner than the controls, although the overall incidences of seizures and respiratory arrest were not significantly different. Pretreatment with IV CCBs resulted in similar findings. To test the therapeutic effect of CCBs given following cocaine overdose, rats were administered cocaine IP and then treated with IV nifedipine or nimodipine once seizures occurred. In these animals, there was no significant difference in the incidence or time to respiratory arrest compared to vehicle controls. This study demonstrates that neither pretreatment nor posttreatment with the CCBs nifedipine or nimodipine reduces cocaine toxicity in this rodent model.

Met-8 of the beta 1-bungarotoxin phospholipase A2 subunit is essential for the phospholipase A2-independent neurotoxic effect

beta 1-Bungarotoxin consists of a phospholipase A2 subunit and a non-phospholipase A2 subunit. The toxin was oxidized with a 100-fold molar excess of chloramine T with respect to the methionine content of the protein in 0.1 M Tris/HCl at pH 8.5 and at room temperature. Reactivities of the two methionine (Met-6 and Met-8 of the phospholipase A2 subunit), five histidine, 14 tyrosine and one tryptophan residues of one toxin molecule with chloramine T were assessed from the change in intrinsic fluorescence and amino acid composition of the protein. Met-8 and one tyrosine on the phospholipase A2 subunit and less than one histidine were oxidized, while Met-6 remained intact after 30 min of reaction. One histidine and approx. two tyrosine residues were oxidized when both methionine residues were oxidized after 90 min of reaction. The sole tryptophan was oxidized slightly throughout the reaction. The chloramine T oxidation did not destroy the two Ca(2+)-binding domains, though it modified the toxin to become less effective at binding Ca2+. The modified toxin obtained after 30 or 90 min reaction time retained 65% or 40% of the phospholipase A2 activity of the parent toxin, but both were not lethal to mice and showed a very weak ability to induce the indirectly evoked contraction of chick biventer cervicis muscle. It is suggested that Met-8 may play an important role in the phospholipase A2-independent interaction with the nerve terminal membrane during the neurotoxic effect of beta 1-bungarotoxin.

Acute cocaine toxicity: the effect of agents in non-seizure-induced death

Death from cocaine intoxication results from one or more of the multiple mechanisms including seizures, cardiovascular collapse, or apnea. In the free-moving rat model, continuous seizures are a major cause of death. To study other mechanisms of death unrelated to seizures in this model, we suppressed lethal seizures with diazepam (DZP) and investigated the effect of several pharmacological agents. Rats were pretreated with vehicle alone, diazepam 5 mg/kg alone, or a combination of DZP plus either nifedipine (NIFD) 2 mg/kg, propranolol (PROP) 10 mg/kg, or prazosin (PRAZ) 5 mg/kg. Five minutes after pretreatment, all animals received cocaine 100 mg/kg. Each test group consisted of 15 animals and all agents were given IP. Two animals in each group had cortical electrodes implanted. Animals that received vehicle followed by cocaine had 100% incidence of seizures and death. Those rats that received DZP alone followed by cocaine had no seizures and 53% death. Rats that received DZP plus NIFD or DZP plus PROP had suppression of seizures but no significant change in the incidence of death. The group that received DZP and PRAZ followed by cocaine had no seizures and 13% incidence of death (p < 0.001). Electroencephalogram recordings showed cortical electrical spike activity or spike-and-wave afterdischarges in all animals clinically observed to have seizures. In the absence of clinical seizure activity, no significant cortical spike activity was noted. It is concluded that animals protected from seizures with diazepam can still have nonseizure deaths after high-dose cocaine. The incidence of death in these animals is not reduced with nifedipine or propranolol pretreatment but is reduced with prazosin pretreatment.

In vitro and in vivo activities of Q-35, a new fluoroquinolone, against Mycoplasma pneumoniae

The in vitro potency and in vivo efficacy of Q-35, a new fluoroquinolone, against Mycoplasma pneumoniae were investigated by pharmacokinetic studies with M. pneumoniae-infected hamsters. By using fluoroquinolones, macrolides, and tetracyclines as references, Q-35 was found to possess the greatest mycoplasmacidal activity. The MIC for 90% of strains tested (MIC90) and the MIC50 were 0.78 and 0.39 microgram/ml, respectively, and the MBC for 90% of strains tested (MBC90) and the MBC50 were 3.13 and 0.78 microgram/ml, respectively. The MBC50-to-MIC50 ratio for Q-35 was 2. Furthermore, only Q-35 continued to be effective against 19 strains of erythromycin-resistant mutants of M. pneumoniae. The efficacies of fluoroquinolones against M. pneumoniae were also investigated by using an experimental hamster pneumonia model to measure the CFU of M. pneumoniae in the lungs. Q-35 and ofloxacin were efficacious following oral administration of 200 mg/kg/day for 5 days, initiated 24 h after infection, while ciprofloxacin was not active. Continuous administration of Q-35 for 10 days significantly reduced numbers of viable M. pneumoniae in the lungs. These results suggest that both Q-35 and ofloxacin are effective in the early phase of infection and, moreover, that Q-35 is also effective in the middle stage of infection, when progressive lung alterations and continuous increases in mycoplasmal growth occur. Peak levels of Q-35 in sera and lungs after oral administration were higher than those of ciprofloxacin but lower than those of ofloxacin. On the basis of these results, Q-35 appears to be a promising antimicrobial agent in chemotherapy of mycoplasmal infection.

Oral health conditions among people visiting a medical center for health checkups

The purpose of this study was to evaluate the oral health conditions of subjects in a southern Taiwan health checkup program. One half of the examinees were selected randomly for oral examination during a two-year period. There were 537 subjects, including 286 men and 251 women with mean ages of 49.7 +/- 13.5 years and 50.2 +/- 12.1 years, respectively. Oral examinations included periodontal condition and existence of dental caries. The periodontal treatment needs of all examinees were evaluated using the Community Periodontal Index of Treatment Needs system and the World Health Organization periodontal probe. Dental caries examination was performed by the visual-tactile method with a mouth mirror and explorer. No radiographs were taken. All clinical evaluations were performed by the first author, who has experience in all of the indices. The results showed that only 0.7% of the subjects had no need of periodontal treatment, 6.7% had bleeding after gentle probing, and 75.2% presented with calculus, overhanging restorations, or pockets of 4 or 5 mm. The remaining 17.3% had pocket depths of 6 mm or deeper. There was no statistically significant difference between males and females in periodontal treatment needs and the mean number of decayed teeth (D). According to this hospital-based observation, most of the people in the health checkup program were in need of periodontal treatment, including oral hygiene instruction, prophylaxis and root planing. Approximately one-fifth of the subjects needed complex periodontal treatment; there were no differences in the treatment needs of males and females.(ABSTRACT TRUNCATED AT 250 WORDS)