Endothelial NO synthase overexpression inhibits lesion formation in mouse model of vascular remodeling

NO produced by endothelial NO synthase (eNOS) plays important roles in the regulation of vascular tone and structure. The purpose of this study was to clarify the role of eNOS-derived NO on vascular remodeling by use of eNOS-transgenic (eNOS-Tg) mice. The common carotid artery was ligated just proximal to the carotid bifurcation. Four weeks later, the proximal carotid artery of the ligation site was histologically examined. In this vascular remodeling model, the endothelium remains uninjured, but neointimal and medial thickening occurs in combination with a reduction in vascular diameter at the proximal portion of the ligation. At 4 weeks after ligation, the respective neointimal and medial areas in wild-type mice were 17 200+/-1100 and 24 300+/-1500 microm(2), whereas both were reduced to 8000+/-1900 (P:<0.01) and 18 400+/-700 microm(2) (P:<0.01) in eNOS-Tg mice (n=8). Total vascular area was not different between the 2 genotypes. N:(G)-Nitro-L-arginine methyl ester treatment increased neointimal and medial areas to the same extent in both genotypes. Leukocyte infiltration was observed in the luminal side of the vessel, but the number of infiltrating cells was significantly attenuated in eNOS-Tg mice compared with wild-type mice. This reduction of leukocyte infiltration in eNOS-Tg mice was associated with reduced expressions of intracellular adhesion molecule-1 and vascular cellular adhesion molecule-1 on the endothelium. In conclusion, chronic eNOS overexpression in the endothelium reduced leukocyte infiltration and inhibited neointimal formation and medial thickening. Our data provide the evidence for the regulatory role of NO from the endothelium on vascular structure integrity.

Intravenous ketamine attenuates arterial pressure changes during the induction of anaesthesia with propofol

BACKGROUND AND OBJECTIVE

To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure.

METHODS

Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg-1 propofol and 0.5 mg kg-1 ketamine or 2 mg kg-1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg-1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation.

RESULTS AND CONCLUSIONS

Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.

Opioids inhibit febrile responses in humans, whereas epidural analgesia does not: an explanation for hyperthermia during epidural analgesia

BACKGROUND

Epidural analgesia is frequently associated with hyperthermia during labor and in the postoperative period. The conventional assumption is that hyperthermia is caused by the technique, although no convincing mechanism has been proposed. However, pain in the "control" patients is inevitably treated with opioids, which themselves attenuate fever. Fever associated with infection or tissue injury may then be suppressed by opioids in the "control" patients while being expressed normally in patients given epidural analgesia. The authors therefore tested the hypothesis that fever in humans is manifested normally during epidural analgesia, but is suppressed by low-dose intravenous opioid.

METHODS

The authors studied eight volunteers, each on four study days. Fever was induced each day by 150 IU/g intravenous interleukin 2. Volunteers were randomly assigned to: (1) a control day when no opioid or epidural analgesia was given; (2) epidural analgesia using ropivacaine alone; (3) epidural analgesia using ropivacaine in combination with 2 microg/ml fentanyl; or (4) intravenous fentanyl at a target plasma concentration of 2.5 ng/ml.

RESULTS

Fentanyl halved the febrile response to pyrogen, decreasing integrated core temperature from 7.0 +/- 3.2 degrees C. h on the control day, to 3.8 +/- 3.0 degrees C. h on the intravenous fentanyl day. In contrast, epidural ropivacaine and epidural ropivacaine-fentanyl did not inhibit fever. The fraction of core-temperature measurements that exceeded 38 degrees C was halved by intravenous fentanyl, and the fraction exceeding 38.5 degrees C was reduced more than fivefold.

CONCLUSIONS

These data support the authors' proposed mechanism for hyperthermia during epidural analgesia. Fever during epidural analgesia should thus not be considered a complication of the anesthetic technique per se.

Hepatocyte nuclear factor-1alpha inhibits insulin promoter factor 1-dependent transactivation of the human insulin gene

To investigate the regulational interaction of hepatocyte nuclear factor-1alpha (HNF-1alpha) and insulin promoter factor 1 (IPF1) on insulin gene expression, either or both of the expression vectors carrying each transcription factor were transiently transfected into HeLa cells, RINm5F cells and MIN6 cells together with the luciferase reporter construct driven by a human preproinsulin gene promoter (-1998 to +237) designated as, pINS-1998/luc. IPF1-transfection into HeLa cells strongly stimulated the luciferase activity to 725 fold that of the basal level. In contrast, HNF-1alpha-transfection resulted in only a 6.7 fold increase. In co-transfection experiments, increasing the amount of HNF-1alpha resulted in an 84.5% and 74.4% decrease in IPF1-stimulated luciferase activity in HeLa and RINm5F cells, respectively. Deletion constructs designated as pINS-248/luc, pINS-213/luc and pINS-185/luc were transfected into RINm5F cells to determine the role of the A3 element and its 5' flanking sequence in the inhibitory effect of HNF-1alpha. The results showed that the inhibiting effects of HNF-1alpha with pINS-213/luc and pINS-185/luc were significantly smaller than those with both pINS-1998/luc and pINS-248/luc. Transfection into MN6 cells with pINS-1998/luc in the absence of IPF1 resulted in constitutional transactivation of the insulin gene, and this transactivation was abolished by the co-transfection with HNF-1alpha. The present data indicate that IPF1 rather than HNF-1alpha predominantly transactivates the insulin gene, and that HNF-1alpha inhibits IPF1-dependent insulin gene transactivation mediated through the 5' flanking sequence of the A3 element. It is suggested that HNF-1alpha may be involved in insulin gene expression as a negative regulator.

Reduced hypoxic pulmonary vascular remodeling by nitric oxide from the endothelium

We examined whether overproduction of endogenous nitric oxide (NO) can prevent hypoxia-induced pulmonary hypertension and vascular remodeling by using endothelial NO-overexpressing (eNOS-Tg) mice. Male eNOS-Tg mice and their littermates (wild-type, WT) were maintained in normoxic or 10% hypoxic condition for 3 weeks. In normoxia, eNOS protein levels, Ca(2+)-dependent NOS activity, and cGMP levels in the lung of eNOS-Tg mice were higher than those of WT mice. Activity of eNOS and cGMP production in the lung did not change significantly by hypoxic exposure in either genotype. Chronic hypoxia did not induce iNOS expression nor increase its activity in either genotype. Plasma and lung endothelin-1 levels were increased by chronic hypoxia, but these levels were not significantly different between the 2 genotypes. In hemodynamic analysis, right ventricular systolic pressure (RVSP) in eNOS-Tg mice was similar to that in WT mice in normoxia. Chronic hypoxia increased RVSP and induced right ventricular hypertrophy in both genotypes; however, the degrees of these increases were significantly smaller in eNOS-Tg mice. Histological examination revealed that hypoxic mice showed medial wall thickening in pulmonary arteries. However, the increase of the wall thickening in small arteries (diameter <80 microm) by chronic hypoxia was inhibited in eNOS-Tg mice. Furthermore, muscularization of small arterioles was significantly attenuated in eNOS-Tg mice. Thus, we demonstrated directly that overproduction of eNOS-derived NO can inhibit not only the increase in RVSP associated with pulmonary hypertension but also remodeling of the pulmonary vasculature and right ventricular hypertrophy induced by chronic hypoxia.

Rainwater drainage management for urban development based on public-private partnership

The Urban Development Corporation (UDC) is one of the biggest implementation bodies for urban development in Japan. UDC has developed rainwater infiltration technology since 1975. This technology has effectively reduced runoff to a river and sewer system in the new town project areas. Recently, UDC has developed a new system which is defined as a "Rainwater Recycle Sewer System", which is supported by "Rainwater Storage and Infiltration Technology (RSIT)" applicable to new town creation and urban renewal. The new system consists of two elements: RSIT components based on Public-Private Partnership (PPP) and a stormwater drainage system. Herein, the private sector is responsible for the main part of RSIT, and the public sector is responsible for the stormwater drainage from the development area. As a result, the capacity of public facilities, such as rainwater sewers and stormwater reservoirs, can be reduced effectively. In parallel, the initial/running cost of public facilities is expected to be reduced. In conclusion, the authors would stress the importance of a co-maintenance system also based on PPP, which will be required especially in order to properly operate the whole system for the long term.

Coffee and fitness-coffee suppresses lipopolysaccharide-induced liver injury in rats

To clarify the relationship between coffee and fitness, we investigated the effect of coffee on weight gain and total cholesterol as well as production of cytokines and activities of GOT (aspartate aminotransferase; EC 2.6.1.1.) and GPT (alanine aminotransferase; EC 2.6.1.2.) as injected lipopolysaccharides. Forty-eight male Wistar rats were divided into three dietary groups (n=16), which were fed a stock diet (control group), the diet supplemented with freeze-dried coffee of 6.2 g/kg (0.62% coffee group), and the diet supplemented with freeze-dried coffee of 13.6 g/kg (1.36% coffee group). It was confirmed by HPLC analysis that the serum caffeine concentrations in both coffee groups became significantly higher in 140 days after the start of feeding. No significant differences in body weight and serum cholesterol were found between the coffee groups and control group, though the coffee groups tended to be somewhat high at cholesterol level. Activities of serum GOT and GPT increased at 2 h after LPS injection, but in the coffee groups were significantly suppressed (p<0.05). However, the coffee feeding could not suppress the increases of serum cytokine (TNF-alpha and IL-6) levels. These results suggest that coffee may serve as a preventive against liver injury.

Surface and flexoelectric polarization in a nematic liquid crystal directly measured by a pyroelectric technique

An alternative, pyroelectric effect based technique was developed for the direct measurement of the surface polarization in homogeneously and homeotropically oriented nematic cells as well as for the measurement of the flexoelectric polarization in hybrid aligned nematic cells. The pyroelectric response was measured with a modulated beam of a diode laser, absorbed by a dye incorporated in a standard liquid crystal 4-pentyl- 4(')-cyanobiphenyl. The dye provided a gradient of the temperature increment along the cell normal, which allowed for the separation of pyroelectric contributions from both the opposite surfaces and the bulk. The signs and absolute magnitude of the polarizations mentioned have been found over the entire temperature range of the nematic phase.

Attenuation of expression of gamma-glutamylcysteine synthetase by ribozyme transfection enhance insulin secretion by pancreatic beta cell line, MIN6

Low levels of intracellular antioxidant enzyme activities as well as glutathione (GSH) concentrations have been described in pancreatic beta cells. We examined the effects of intracellular GSH depletion on insulin secretion and the role of intracellular GSH in signal transduction in beta cell line, MIN6 cells. Anti-gamma-glutamylcysteine synthetase (gamma-GCS) heavy subunit ribozyme was stably transfected to MIN6 cells to reduce intracellular GSH concentration. In the presence of 10 mM glucose, ribozyme-transfected cells (RTC) increased insulin secretion from 0.58 microg/10(6) cells/h in control cells (CC) to 1.48 microg/10(6) cells/h. This was associated with increased intracellular Ca(2+) concentration in RTC, detected by fluo-3 staining. Our results demonstrated that intracellular GSH concentration might influence insulin secretion by MIN6 cells, and suggest that enhanced insulin secretion by beta cells conditioned by chronic depletion of GSH is mediated by increased intracellular Ca(2+) concentration.

Rac1 regulates stress-induced, redox-dependent heat shock factor activation

The signaling pathway by which environmental stresses activate heat shock factors (HSFs) is not completely understood. We show that the small GTPase rac1, and Rac1-regulated reactive oxygen species (ROS) play an important role in stress-stimulated heat shock response. A dominant-negative allele of Rac1 (Rac1N17) inhibits the hypoxia/reoxygenation and sodium arsenite-induced transcriptional activity of HSF-1 and the transcription of heat shock protein 70. Rac1N17 also suppresses the production of intracellular ROS induced by hypoxia/reoxygenation or sodium arsenite. Moreover, direct suppression of intracellular ROS levels by antioxidants decreases stress-stimulated HSF activity. However, expression of a constitutively active mutant of Rac1 (Rac1V12) in the absence of extracellular stresses does not increase intracellular ROS levels or induce the heat shock response. These results show that Rac1 is a necessary but insufficient component of the stress-induced signaling pathway that leads to ROS production, activation of HSFs, and transcription of heat shock proteins.

Comparison of endothelium-dependent relaxation in carotid arteries from Japanese white and Watanabe heritable hyperlipidemic rabbits

Modifications by atherosclerosis of endothelium-dependent and -independent relaxations were evaluated in carotid arteries isolated from Watanabe heritable hyperlipidemic (WHHL; age 20-29 months) and age-matched Japanese white (JW) rabbits. Marked, patchy atherosclerotic lesions were observed in all WHHL rabbit arteries. Endothelium-dependent relaxations induced by acetylcholine, partly depressed by N(G)-nitro-L-arginine (L-NA), were significantly inhibited in the WHHL rabbit arteries with atherosclerosis, compared with those in the arteries without atherosclerotic lesions from JW and WHHL rabbits. No difference was observed in the relaxation caused by superoxide dismutase in these arteries. Conversely, endothelium-dependent relaxations by substance P were greater in the arteries with and without atherosclerosis from WHHL rabbits than in the arteries from JW rabbits. Endothelium-independent relaxations elicited by sodium nitroprusside and 2,2-(hydroxynitrosohydrazino)bis-ethanamine (NOC18) did not differ in the arteries from JW and WHHL rabbits. The responses to acetylcholine and substance P of JW rabbit arteries with the endothelium were not attenuated by treatment with pertussis toxin. L-NA-resistant, endothelium-dependent relaxations by substance P were almost abolished by charybdotoxin, and atherosclerosis did not alter the response. It is concluded that endothelial functions, evaluated by substance P, in rabbit carotid arteries are not impaired by atherosclerosis and by long exposure to hyperlipidemia in vivo. Dysfunction of muscarinic receptors may be involved in the depressed response to acetylcholine. As far as the arteries used in the present study are concerned, responses mediated possibly by endothelium-derived hyperpolarizing factor (EDHF) are unlikely to be modulated by atherosclerosis.

[Guideline for the treatment of Hansen's disease in Japan]

Ad hoc committee of Japanese Leprosy Association recommends standard treatment protocol of leprosy in Japan, which is a modification of World Health Organization's multidrug therapy (WHO/MDT, 1997). For paucibacillary (PB) leprosy, 6 months treatment by rifampicin and dapsone (MDT/PB) is enough. However, for high bacterial load multibacillary (MB) leprosy, 12 months treatment seems insufficient. Thus, (A) For MB with bacterial index (BI) > or = 3 before treatment, 2 years treatment by rifampicin, dapsone and clofazimine (MDT/MB) is necessary. (A-1) When satisfactory decrease of BI (BI value decrease > or = 2 steps, or final BI < 3) is obtained after completion of 2 years MDT/MB, maintenance therapy by dapsone and clofazimine is recommended until BI negativity and loss of active lesions. (A-2) When BI decrease is not satisfactory (BI value decrease < 2 steps, or final BI > or = 3), MDT/MB should be continued until BI negativity and loss of active lesions. (B) For MB with BI < 3 or fresh MB (less than 6 months after the onset of the disease) with BI > or = 3, 1 year treatment by rifampicin, dapsone and clofazimine (MDT/MB) is necessary. (B-1) When BI become negative and active lesion is lost within one year, no maintenance therapy is necessary. (B-2) When BI is still positive or active lesion is remaining, additional therapy with MDT/MB for one more year is recommended. Brief summary of diagnosis, purpose of therapy, character of drugs, and prevention of deformity is also described.

cGMP-independent inotropic effects of nitric oxide and peroxynitrite donors: potential role for nitrosylation

Nitric oxide (NO) has concentration-dependent biphasic myocardial contractile effects. We tested the hypothesis, in isolated rat hearts, that NO cardiostimulation is primarily non-cGMP dependent. Infusion of 3-morpholinosydnonimine (SIN-1, 10(-5) M), which may participate in S-nitrosylation (S-NO) via peroxynitrite formation, increased the rate of left ventricular pressure rise (+dP/dt; 19 +/- 4%, P < 0.001, n = 11) without increasing effluent cGMP or cAMP. Superoxide dismutase (SOD; 150 U/ml) blocked SIN-1 cardiostimulation and led to cGMP elaboration. Sodium nitroprusside (10(-10)-10(-7) M), an iron nitrosyl compound, did not augment +dP/dt but increased cGMP approximately eightfold (P < 0.001), whereas diethylamine/NO (DEA/NO; 10(-7) M), a spontaneous NO. donor, increased +dP/dt (5 +/- 2%, P < 0.05, n = 6) without augmenting cGMP. SIN-1 and DEA/NO +dP/dt increase persisted despite guanylyl cyclase inhibition with 1H-(1,2,4)oxadiazolo-(4,3,-a)quinoxalin-1-one (10(-5) M, P < 0.05 for both donors), suggesting a cGMP-independent mechanism. Glutathione (5 x 10(-4) M, n = 15) prevented SIN-1 cardiostimulation, suggesting S-NO formation. SIN-1 also produced SOD-inhibitable cardiostimulation in vivo in mice. Thus peroxynitrite and NO donors can stimulate myocardial contractility independently of guanylyl cyclase activation, suggesting a role for S-NO reactions in NO/peroxynitrite-positive inotropic effects in intact hearts.

"Deep-forehead" temperature correlates well with blood temperature

PURPOSE

To evaluate the accuracy and precision of "deep-forehead" temperature with rectal, esophageal, and tympanic membrane temperatures, compared with blood temperature.

METHODS

We studied 41 ASA physical status 1 or 2 patients undergoing abdominal and thoracic surgery scheduled to require at least three hours. "Deep-forehead" temperature was measured using a Coretemp thermometer (Terumo, Tokyo, Japan). Blood temperature was measured with a thermistor of a pulmonary artery. Rectal, tympanic membrane, and distal esophageal temperatures were measured with thermocouples. All temperatures were recorded at 20 min intervals after the induction of anesthesia. We considered blood temperature as the reference value. Temperatures at the other four sites were compared with blood temperature using correlation, regression, and Bland and Altman analyses. We determined accuracy (mean difference between reference and test temperatures) and precision (standard deviation of the difference) of 0.5 degrees C to be clinically acceptable.

RESULTS

"Deep-forehead" temperature correlated well with blood temperature as well as other temperatures, the determination coefficients (r2) being 0.85 in each case. The bias for the "deep-forehead" temperature was 0.0 degrees C, which was the same as tympanic membrane temperature and was smaller than rectal and esophageal temperatures. The standard deviation of the differences for the "deep-forehead" temperature was 0.3 degrees C, which was the same as rectal temperature.

CONCLUSIONS

We have demonstrated that the "deep-forehead" temperature has excellent accuracy and clinically sufficient precision as well as other three core temperatures, compared with blood temperature.

[Meningococcemia associated with C7 deficiency]

We report a 20-year-old woman who developed meningococcemia. The patient developed fever, vomiting and skin rash, then was sent to our hospital for shock. Physical and laboratory examination revealed septic shock and DIC. Her blood culture grew Neisseria meningitidis (W135). She recovered promptly with PCG, gabexate mesilate and intensive care for shock. Hemolytic activities of the patient's complement were less than 12/CH50 during the course. Screening for each component of the complements suggested that this patient had deficiency of C7. Meningococcal disease has seldom seen in Japan. Early recognition is essential so that appropriate antibiotic therapy and supportive care can be promptly started because shock and death may ensure within hours after onset of symptoms.

Rac1 inhibits TNF-alpha-induced endothelial cell apoptosis: dual regulation by reactive oxygen species

Reactive oxygen species (ROS) have been implicated as mediators of tumor necrosis factor-alpha (TNF) -induced apoptosis. In addition to leading to cell death, ROS can also promote cell growth and/or survival. We investigated these two roles of ROS in TNF-induced endothelial cell apoptosis. Human umbilical vein endothelial cells (HUVECs) stimulated with TNF produced an intracellular burst of ROS. Adenoviral-mediated gene transfer of a dominant negative form of the small GTPase Rac1 (Rac1N17) partially suppressed the TNF-induced oxidative burst without affecting TNF-induced mitochondrial ROS production. HUVECs were protected from TNF-induced apoptosis. Expression of Rac1N17 blocked TNF-induced activation of nuclear factor-kappa B (NF-kappaB), increased activity of caspase-3, and markedly augmented endothelial cell susceptibility to TNF-induced apoptosis. Direct inhibition of NF-kappaB through adenoviral expression of the super repressor form of inhibitor of kappaBalpha (I-kappaB S32/36A) also increased susceptibility of HUVECs to TNF-induced apoptosis. Rotenone, a mitochondrial electron transport chain inhibitor, suppressed TNF-induced mitochondrial ROS production, proteolytic cleavage of procaspase-3, and apoptosis. These findings show that Rac1 is an important regulator of TNF-induced ROS production in endothelial cells. Moreover, they suggest that Rac1-dependent ROS, directly or indirectly, lead to protection against TNF-induced death, whereas mitochondrial-derived ROS promote TNF-induced apoptosis.

[Use of modified infrared aural canal thermometers during cardiac surgery]

Two kinds of modified infrared aural canal thermometers (Mimippi, Superthermo) are currently available in Japan. We therefore evaluated their accuracy and precision for clinical use. For the purpose of this investigation, we considered accuracy to be the mean difference between the test thermometers and the reference thermocouple. Precision was examined from the standard deviation of the difference between the test and reference values. We evaluated ten patients for cardiopulmonary bypass surgery under mild hypothermia (approximately 32 degrees C). Aural canal temperatures were measured in a random order with each infrared thermometer, and compared with readings from a thermocouple positioned at the contralateral tympanic membrane. Compared with the thermocouple, the Mimippi had regression slope 0.87 and correlation coefficient 0.79. In contrast, slope of the Superthermo regression was 0.74. The correlation coefficient for the Superthermo was 0.71. The accuracy (offset, or bias) was 0.91 degree C with the Mimippi. In contrast, it was 1.32 degrees C with the Superthermo. The precision (standard deviation) of the Mimippi was 0.65. In contrast, it was 0.73 degree C with the Superthermo. We conclude that both thermometers were moderately accurate and precise for perioperative use.

Predictive value of remnant-like particle cholesterol as an indicator of coronary artery stenosis in patients with normal serum triglyceride levels

OBJECTIVE

We designed the present study to evaluate the association of various lipid and fibrinolytic components with coronary artery stenosis with respect to the triglyceride (TG) level.

METHODS

Levels of TG, remnant-like particle cholesterol (RLP-C), total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein-(a), uric acid, blood glucose, tissue plasminogen activator (t-PA), t-PA inhibitor type 1, antithrombin III, and protein C were measured in 208 patients who underwent diagnostic coronary angiograms.

PATIENTS

Of these 208 patients, 59 were hypertriglyceridemic (150 mg/dl or higher) and 149 were normotriglyceridemic.

RESULTS

Both LDL-C and HDL-C showed significant differences between patients with and those without coronary artery stenosis in both hypertriglyceridemic and normotriglyceridemic patient subgroups. However, RLP-C showed a significant difference in the normotriglyceridemic patient subgroup (p=0.012) but not in the hypertriglyceridemic patient subgroup (p=0.736).

CONCLUSION

Our current retrospective study disclosed that RLP-C levels are closely associated with coronary artery stenosis in patients with normal TG levels.

Mechanisms of reduced nitric oxide/cGMP-mediated vasorelaxation in transgenic mice overexpressing endothelial nitric oxide synthase

NO, constitutively produced by endothelial NO synthase (eNOS), plays a key regulatory role in vascular wall homeostasis. We generated transgenic (Tg) mice overexpressing eNOS in the endothelium and reported the presence of reduced NO-elicited relaxation. The purpose of this study was to clarify mechanisms of the reduced response to NO-mediated vasodilators in eNOS-Tg mice. Thoracic aortas of Tg and control mice were surgically isolated for vasomotor studies. Relaxations to acetylcholine and sodium nitroprusside were significantly reduced in Tg vessels compared with control vessels. Relaxations to atrial natriuretic peptide and 8-bromo-cGMP were also significantly reduced in Tg vessels. Reduced relaxations to these agents were restored by chronic N(G)-nitro-L-arginine methyl ester treatment. Basal cGMP levels of aortas were higher in Tg mice than in control mice, whereas soluble guanylate cyclase (sGC) activity in Tg vessels was approximately 50% of the activity in control vessels. Moreover, cGMP-dependent protein kinase (PKG) protein levels and PKG enzyme activity were decreased in Tg vessels. These observations indicate that chronic overexpression of eNOS in the endothelium resulted in resistance to the NO/cGMP-mediated vasodilators and that at least 2 distinct mechanisms might be involved: one is reduced sGC activity, and the other is a decrease in PKG protein levels. We reported for the first time that increased NO release from the endothelium reduces sGC and PKG activity in mice. These data may provide a new insight into the mechanisms of nitrate tolerance and cross tolerance to nitrovasodilators.

Alfentanil reduces the febrile response to interleukin-2 in humans

OBJECTIVE

Manifestation of intraoperative fever is impaired by volatile anesthetics and muscle relaxants. Opioids are common anesthetic adjuvants and remain the dominant treatment for postoperative surgical pain and sedation of critically ill patients. The effect of opioids on normal thermoregulatory control is well established. However, the extent to which these drugs might inhibit fever remains unknown. Accordingly, we tested the hypothesis that relatively low plasma concentrations of the mu-receptor agonist alfentanil reduce fever magnitude.

DESIGN

Prospective, randomized, crossover study.

SETTING

Outcomes Research Laboratory, at the Department of Anesthesia and Perioperative Care, University of California, San Francisco.

PATIENTS

Eight healthy male volunteers, aged 25-31 yrs, each studied on three separate days.

INTERVENTION

Each volunteer was given an intravenous injection of 30 IU/g interleukin (IL)-2, followed 2 hrs later by 70 IU/g. One hour after the second dose, the volunteers were randomly assigned to three doses of alfentanil: a) none (control); b) a target plasma concentration of 100 ng/mL; and c) a target concentration of 200 ng/mL. Opioid administration continued for 5 hrs.

METHODS AND MAIN RESULTS

Alfentanil significantly reduced the febrile response to pyrogen, decreasing integrated tympanic membrane temperatures from 7.5+/-2.2 degrees C x hr on the control day, to 4.9+/-1.5 degrees C x hr with 100 ng/mL alfentanil, and to 5.1+/-1.7 degrees C x hr with 200 ng/mL alfentanil (p = .011). Peak temperatures were also significantly reduced from 38.5+/-0.4 degrees C on the control day, to 38.0+/-0.4 degrees C on the 100 ng/mL-alfentanil day and 38.0+/-0.6 degrees C on the 200-ng/mL day (p = .019). Plasma cytokine concentrations increased after IL-2 administration, roughly in proportion to the elevation in core temperature. However, cytokine concentrations did not differ significantly among the treatment groups.

CONCLUSION

Alfentanil significantly reduced the febrile response to IL-2 administration. However, the reduction was comparable at plasma concentrations near 100 and 200 ng/mL. These data indicate that concentrations of opioids commonly observed in critical care patients significantly inhibit the manifestation of fever.

Evaluation of insulin response in glucose tolerance test in a patient with Werner's syndrome: a 16-year follow-up study

To clarify the effect of Werner's syndrome (WS) on beta-islet cell function, the oral glucose tolerance test (OGTT) was repeatedly performed over a period of 16 years in one patient with WS. The data obtained on insulin secretion were assessed in this study. The patient was a 50-yr-old woman of consanguineous parentage. She presented with gray hair, cataracts, a beak-shaped nose and high-pitched voice. She was diagnosed as WS on the basis of her characteristic appearance. OGTT was performed 14 times during 9 admissions to our hospital. After ingestion of glucose, plasma glucose (PG) levels and immuno-reactive insulin (IRI) at 0, 30, 60, 90, 120 and 180 min were determined. PG levels during OGTT gradually increased during dietary therapy and, at the age of 48, insulin treatment was started [PG level at 120 min during OGTT at 46 yr (before treatment) was 1.5 times that at 34 yr]. Insulin secretion had also gradually decreased during the follow-up period (sum of IRI at 34 yr during OGTT post-treatment; 550.8 IU/ml, sum of IRI at 50 yr during OGTT post-treatment; 244.5 IU/ml). However, the insulinogenic indices were maintained at almost the same level value. Our results indicate that insufficient insulin secretion, which could not overcome insulin resistance, might play a crucial role in the pathophysiology and progression of diabetes in WS along with insulin resistance due to a post-receptor defect.

Preferential potentiation by nitric oxide of spontaneous inhibitory postsynaptic currents in rat supraoptic neurones

Magnocellular neurones in the supraoptic nucleus and paraventricular nucleus express mRNA for nitric oxide synthase (NOS) and the expression becomes more prominent when the release of vasopressin or oxytocin is stimulated. It has also been reported that NO donors inhibit the electrical activity of supraoptic nucleus neurones, but the mechanism involved in the inhibition remains unclear. In the present study, to know whether modulation of synaptic inputs into supraoptic neurones is involved in the inhibitory effect of NO, we measured spontaneous excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) from rat supraoptic nucleus neurones in slice preparations identified under a microscope using the whole-cell mode of the slice-patch-clamp technique. The NO donor, S-nitroso-N-acetylpenicillamine (SNAP), reversibly increased the frequency of spontaneous IPSCs mediated by GABAA receptors, without affecting the amplitude, indicating that NO potentiated IPSCs via a presynaptic mechanism. The NO scavenger, haemoglobin, suppressed the potentiation of IPSCs by SNAP. On the other hand, SNAP did not cause significant effects on EPSCs mediated by non-NMDA glutamate receptors. The membrane permeable analogue of cGMP, 8-bromo cGMP, caused a significant reduction in the frequency and amplitude of both IPSCs and EPSCs. The results suggest that NO preferentially potentiates the inhibitory synaptic inputs into supraoptic nucleus neurones by acting on GABA terminals in the supraoptic nucleus, possibly via a cGMP-independent mechanism. The potentiation may, at least in part, account for the inhibitory action of NO on the neural activity of supraoptic neurones.

Roles of neuregulin in synaptogenesis between mossy fibers and cerebellar granule cells

Neuregulins (NRGs), a large group of structurally related signaling proteins, are likely to have important roles in the development, maintenance and repair of the nervous system and other selected tissues. We have demonstrated, by using the major form of NRG cloned from the mouse cerebellum that both the soluble form and the membrane anchored form of NRG may serve different functions in synaptogenesis. The soluble form of NRG was produced by proteolytic cleavage of the membrane anchored form of NRG. The proteolytic cleavage was promoted by protein kinase activation. The cleaved form of NRG trans-synaptically regulated the expression of the NMDA (N-methyl-D-aspartate) receptor subunit NR2C as neurally-derived factors, whereas the membrane anchored form of NRG showed a homophilic binding activity between NRGbeta1s. In adult mice the membrane anchored form of NRG was concentrated in neuro-terminals of both granule cells and pontocerebellar mossy fibers. The fact that NRG can be functionally viewed as cell recognition molecules as well as neurotrophic agents suggests new possibilities for the important class of molecules.

Chromosaponin I stimulates the sugar taste receptor cells of the blowfly, Phormia regina

Chromosaponin I (CSI), a gamma-pyronyl-triterpenoid saponin isolated from pea and other leguminous plants, stimulates the growth of roots in a variety of plants. In the present work, we introduce CSI as a sugar taste substance for the blowfly, Phormia regina. The blowfly has taste chemosensilla on the labellum. The sensory receptor cells in the chemosensillum are highly specialized for the tastes of sugar, salt and water, respectively. Application of CSI induced the feeding response of blowflies including full proboscis extension. CSI also induced impulses of the sugar taste receptor cell in the LL-type sensillum. The optimum concentration of CSI in these responses was 0.1 mM which is much lower than that of sucrose. Based on the comparison of dose-response relationships, CSI is 100 times more effective than sucrose in stimulating the sugar taste receptor cells. CSI-induced impulses appeared after a significant latency compared with sucrose. As far as we know, this is the first report describing that a natural saponin induces sugar responses in insects. CSI is a unique saponin because of its bifunctional property in plants and insects.

Resistance to endotoxin shock in transgenic mice overexpressing endothelial nitric oxide synthase

BACKGROUND

Nitric oxide (NO) plays a central role in the pathogenesis of septic shock. However, the role of the NO produced by endothelial NO synthase (eNOS) in septic shock is still unclear. We examined the effect of chronic eNOS overexpression and the role of eNOS-derived NO in lipopolysaccharide (LPS)-induced septic shock using eNOS transgenic (Tg) mice.

METHODS AND RESULTS

LPS was intraperitoneally injected into Tg and control mice. No differences existed in the peak plasma nitrate and nitrate levels induced by LPS between the 2 genotypes. In LPS-treated control mice, blood pressure progressively declined and reached 60% of basal levels (from 97+/-3 to 59+/-3 mm Hg) 24 hours after LPS injection. In contrast, the blood pressure of LPS-treated Tg mice fell only 15% from basal levels (from 84+/-4 to 71+/-4 mm Hg) after the first 6 hours and, thereafter, it remained at this level. LPS-induced increases in the expression of the mRNA of both vascular cell adhesion molecule-1 and intracellular adhesion molecule-1 in the lungs were significantly lower in Tg mice than in control mice. LPS-induced pulmonary leukocyte infiltration and increases in lung water content were also significantly attenuated in Tg mice. Histological examination revealed that lung injury after LPS injection was milder in Tg mice. Furthermore, Tg mice exhibited enhanced survival from LPS-induced septic shock compared with control mice.

CONCLUSIONS

Chronic eNOS overexpression in the endothelium of mice resulted in resistance to LPS-induced hypotension, lung injury, and death. These effects are associated with the reduced vascular reactivity to NO and the reduced anti-inflammatory effects of NO.

Effect of chronic treatment with perindopril on endothelium-dependent relaxation of aorta and carotid artery in SHRSP

Endothelium-dependent relaxation of aorta and carotid artery from stroke-prone spontaneously hypertensive rats (SHRSP) and the effect of chronic treatment of SHRSP with perindopril, an angiotensin converting enzyme inhibitor, on endothelium-dependent relaxation were studied. Endothelium-dependent relaxation was induced by acetylcholine (ACh) in preparations of SHRSP and normotensive Wistar Kyoto rats (WKY) precontracted with noradrenaline. The ACh-induced relaxation in both preparations was abolished by L-nitroarginine. The ACh-induced relaxation was impaired in preparations from SHRSP and contraction was observed at high concentrations of ACh. In the presence of indomethacin, impairment of endothelium-dependent relaxation in SHRSP was minimized and the contraction was inhibited. The relaxation with sodium nitroprusside did not differ between the preparations from WKY and SHRSP. Treatment of SHRSP with perindopril (2 mg/kg/day) for 6 weeks decreased systolic blood pressure and improved the ACh-induced relaxation of aorta and carotid artery. The treatment inhibited the contraction by higher concentrations of ACh in the presence of L-nitroarginine. These results indicate that the impairment of endothelium-dependent relaxation in aorta and carotid artery of SHRSP may be caused by the reduced availability of nitric oxide. The perindopril-treatment may prevent these changes in SHRSP.

Inhibition of the Rac1 GTPase protects against nonlethal ischemia/reperfusion-induced necrosis and apoptosis in vivo

Reperfusion of ischemic tissue results in the generation of reactive oxygen species that contribute to tissue injury. The sources of reactive oxygen species in reperfused tissue are not fully characterized. We hypothesized that the small GTPase Rac1 mediates the oxidative burst in reperfused tissue and thereby contributes to reperfusion injury. In an in vivo model of mouse hepatic ischemia/reperfusion injury, recombinant adenoviral expression of a dominant negative Rac1 (Rac1N17) completely suppressed the ischemia/reperfusion-induced production of reactive oxygen species and lipid peroxides, activation of nuclear factor-kappa B, and resulted in a significant reduction of acute liver necrosis. Expression of Rac1N17 also suppressed ischemia/reperfusion-induced acute apoptosis. The protection offered by Rac1N17 was also evident in knockout mice deficient for the gp91phox component of the phagocyte NADPH oxidase. This work demonstrates the crucial role of a Rac1-regulated oxidase in mediating the production of injurious reactive oxygen species, which contribute to acute necrotic and apoptotic cell death induced by ischemia/reperfusion in vivo. Targeted inhibition of this oxidase, which is distinct from the phagocyte NADPH oxidase, should provide a new avenue for in vivo therapy aimed at protecting organs at risk from ischemia/reperfusion injury.-Ozaki, M., Deshpande, S. S., Angkeow, P., Bellan, J., Lowenstein, C. J., Dinauer, M. C., Goldschmidt-Clermont, P. J., Irani, K. Inhibition of the Rac1 GTPase protects against nonlethal ischemia/reperfusion-induced necrosis and apoptosis in vivo.

Comparison of infrared thermometer with thermocouple for monitoring skin temperature

OBJECTIVE

To test the hypothesis that the infrared thermometer (Genius) is comparably useful with thermocouples that are routinely used for skin temperature monitoring.

DESIGN

Prospective, controlled, not blinded study.

SETTING

Operating room of a university hospital.

SUBJECTS

Ten healthy male volunteers.

INTERVENTIONS

Volunteers were minimally clothed and were initially warmed by a forced air warmer until they became vasodilated at the finger and the foot for approximately 30 mins. Subsequently, they were kept in the room with no blanket.

MEASUREMENTS AND MAIN RESULTS

Skin temperatures were measured continuously with the Mon-a-Therm thermocouple and were also measured with the Genius thermometer just before and after the warming and subsequently every 10 mins for 70 mins. Forearm and finger-tip skin temperatures and skin-surface temperature gradients (from arm to finger and from calf to toe) measured by the Genius thermometer were compared with those measured by the Mon-a-Therm thermocouple using linear regression and Bland and Altman statistics. Forearm temperature and finger-tip temperature ranged from approximately 31 degrees to approximately 36.5 degrees C (87.8-97.7 degrees F) and approximately 22.5 degrees to approximately 36 degrees C (72.5-96.8 degrees F), respectively. Gradients (from arm to finger and from calf to toe) ranged from approximately -3 degrees to approximately 10 degrees C (26.6-50.0 degrees F) and approximately -3 degrees to approximately 11 degrees C (26.6-51.8 degrees F), respectively. Correlations between the temperatures measured by the Genius thermometer and those by the Mon-a-Therm thermocouple were similar and reliable. The correlation coefficients were as follows: 0.78 at forearm, 0.97 at finger-tip, and 0.97 at skin-surface temperature gradients.

CONCLUSIONS

The infrared thermometer with a special probe is useful to measure the change of skin-surface temperatures and to evaluate the severity of shock in patients.

Association of remnant-like particle cholesterol with coronary artery disease in patients with normal total cholesterol levels

BACKGROUND

Limited information is available as to whether there is a difference in the association of lipid and fibrinolytic variables with coronary artery disease according to the presence or absence of elevated serum total cholesterol. We examined the levels of various lipid and fibrinolytic variables including remnant-like particle cholesterol (RLP-C). RLP-C is a recently established simple assay method for the estimation of triglyceride-rich lipoprotein remnants.

METHODS AND RESULTS

Levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride, lipoprotein(a), RLP-C, uric acid, blood glucose, tissue plasminogen activator, tissue plasminogen activator inhibitor type 1, antithrombin III, and protein C were measured in 208 patients who underwent diagnostic coronary angiograms. Of these 208 patients, 57 were hypercholesterolemic (> or =220 mg/dL) and 151 were normocholesterolemic. HDL-C showed significant differences between patients with and those without angiographically determined coronary artery stenosis in both hypercholesterolemic and normocholesterolemic patients (P =.0025 and P =.0003, respectively). Both RLP-C and uric acid showed significant differences only in the normocholesterolemic subgroup (P =.0006 and P =.0060, respectively). This difference in uric acid was not significant by multivariable analysis. The ratio of RLP-C/HDL-C was demonstrated to be highly significantly (P <.0001) associated with coronary artery stenosis in patients with normal total cholesterol, whereas there was no statistically significant association in the hypercholesterolemic patient subgroup.

CONCLUSIONS

Our current study disclosed that RLP-C levels are strongly associated with coronary artery disease, especially in patients with normal total cholesterol levels. Moreover, RLP-C/HDL-C ratio may be even more significantly associated with the presence of coronary artery stenosis in normocholesterolemic patients.

Anti-insulin receptor autoantibodies in a patient with type B insulin resistance and fasting hypoglycemia

We studied a patient with systemic lupus erythematosus and type B insulin resistance who showed almost complete normalization of postprandial plasma glucose in 3 months and a transient occurrence of fasting hypoglycemia from day 35 (i.e. the 35th day of hospitalization) to day 77. To determine the clinical relevance of the biological ability of anti-insulin receptor antibodies (anti-IRAb), we made multiple preparations of the patient's dialyzed serum and IgG. Dialyzed serum prepared on day 1 showed 95% inhibition of insulin binding. The binding inhibition was, however, decreased parallel to the normalization of insulin sensitivity. For 2DG uptake, 6.2 microM IgG purified on 3 different days (days 7, 35 and 78, designated IgG-NOV, -JAN, and -FEB, respectively) stimulated 2DG uptake into CHO-hIR at 3.4-, 3.1-, and 1.5-fold, respectively. Phosphotyrosine immunoblotting revealed that apparent insulin receptor autophosphorylation was visible only with IgG-NOV, not with the IgG-JAN or -FEB. Mutation of tyrosine-960 or lysine-1018 of the insulin receptor failed to transduce the IgG's stimulatory effect. IgG-NOV was not able to stimulate the autophosphorylation of the human IGF-I receptor. In the present study, the insulin binding inhibitory activities of the dialyzed sera prepared at different time points were shown to be altered parallel to insulin sensitivity in vivo. Stimulatory activities of the patient's IgG were, however, discordant for the occurrence of fasting hypoglycemia observed in vivo. Other pathogenic factors or mechanisms in addition to the insulin-like action of the anti-IRAb may be also required to fully understand the development of fasting hypoglycemia in type B insulin resistance.

Characteristics of post-tetanic contraction induced by naloxone in guinea pig ileum

The characteristics of isolated guinea-pig ileal contractions of basal tension after tetanic stimulation in the presence of a high concentration of naloxone (NLX) [post-tetanic contraction] were investigated. The post-tetanic contraction did not occur in the absence of NLX, but did occur in a concentration-dependent manner in the presence of a high concentration of NLX (5 x 10(-7), 10(-6), 10(-5) and 5 x 10(-5) M), the concentration of which was higher than that required for antagonizing post-tetanic twitch inhibition. The contraction in the presence of 10(-6) M NLX was diminished by washing NLX from the preparation with Krebs-bicarbonate solution. The contraction under 10(-6) M NLX occurred in a frequency-dependent manner (5, 10 and 20 Hz), but not at 0.1 Hz. Tetanic stimulation (5, 10 and 20 Hz) without NLX did not induce this contraction. The post-tetanic contraction with 10(-6) M NLX had a tendency to be antagonized in the presence of 5 x 10(-6) M atropine. Methysergide (5 x 10(-5) M) had no effect on this contraction. Spantide (10(-5) M) largely inhibited the contraction, and indomethacin (5 x 10(-6) M) and tetrodotoxin (5 x 10(-7) M) completely inhibited this contraction. These results indicate that tetanic stimulation in the presence of a high concentration of NLX induces contraction of the ileal muscle due to the release of endogenous ileal contractile substances (substance P, prostaglandins and acetylcholine), and suggests that these contractions are closely linked to the endogenous opioid system induced by tetanic stimulation in the ileum.

Identification and functional analysis of mutations in the hepatocyte nuclear factor-1alpha gene in anti-islet autoantibody-negative Japanese patients with type 1 diabetes

Mutations in the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene are the cause of maturity-onset diabetes of the young type 3 (MODY 3), which is characterized by a severe impairment of insulin secretion and early onset of the disease. Although the majority of patients with type 1 diabetes have type 1A, immune-mediated diabetes, there is a significant percentage of the patients who have no evidence of an autoimmune disorder at the onset of disease. The aim of this study was to estimate the prevalence of MODY 3 in antiislet autoantibody negative patients with type 1 diabetes. From a large population-based sample of unrelated Japanese patients with type 1 diabetes, 28 patients who lacked autoantibodies to glutamic acid decarboxylase, islet cell antigen 512/insulinoma-associated antigen-2, phogrin (phosphate homolog of granules of insulinoma)/insulinoma-associated antigen-2beta, and insulin at the onset of type 1 diabetes were examined by PCR-based direct sequencing of the 10 exons, flanking introns, and the promoter region of the HNF-1alpha gene. Two (7.1%) of 28 autoantibody-negative patients with type 1 diabetes were identified as carrying mutations in the HNF-1alpha gene. One patient carried a frameshift mutation (Pro379fsdelCT) in exon 6, and another patient carried a novel 2-bp substitution at nucleotides +45 (G to A) and +46 (C to A) from the transcriptional site of the promoter region. These mutations were identified in heterozygous form and were not identified in 64 unrelated healthy control subjects or 54 unrelated islet autoantibody-positive patients with type 1 diabetes. Functional analysis of the mutant HNF-1alpha gene indicated that the Pro379fsdelCT mutation had no transcriptional trans-activation activity and acted in a dominant negative manner. The +45/46 GC to AA mutation in the promoter region showed reduced promoter activity by 10-20% compared to the wild-type sequence. In conclusion, about 7% of Japanese diabetic patients lacking antiislet autoantibodies initially classified as having type 1 diabetes could have diabetes caused by mutations in the HNF-1alpha gene.

[Lidocaine metabolism associated with epidural anesthesia in patients for hepatic surgery]

We measured plasma concentrations of lidocaine and its principal metabolite, monoethylglycinexylidide (MEGX) associated with thoracic epidural anesthesia using continuous infusion of lidocaine in 10 patients for hepatectomy and other 10 patients for elective abdominal surgery as a control. Plasma concentrations of lidocaine and MEGX were analysed by fluorescence polarization immunoassay and high performance liquid chromatography, respectively. Plasma lidocaine concentration increased gradually, and peaked to 5.1 +/- 2.3 micrograms.ml-1 (mean +/- SD) at the end of surgery in the hepatectomy group, but not in the control group. No significant differences were observed in plasma MEGX concentration between these two groups. Our findings suggest that MEGX formation by the hepatic cytochrome P-450 system might be impaired associated with hepatic surgery. Hypoperfusion of the liver induced by surgical manipulation may have contributed to this impaired metabolism.

A recurrent case of BT leprosy with widely spread skin lesions showing a histopathology of indeterminate group after 4.5-years irregular treatment, Bangladesh

A 29 year-old Bengali male case is presented in this paper which was a borderline tuberculoid leprosy (BT) at detection. His father contracted a lepromatous leprosy of G = 2 deformity. He took anti-leprosy drugs including MDT/MB regimen irregularly and had maculae widely-spread with anesthesia 16 months after being released from treatment (RFT). The histopathology of the maculae unexpectedly showed that of an indeterminate group of leprosy. The recurrent skin lesions were susceptive to a four-week regimen of Rifampicin and Ofloxacin. This case can not be defined as a relapsed case, because slit skin smears were always negative. It would be called a recurrent case after MDT/MB regimen. Though the reason recurrent skin lesions occur is unknown, it is reasonable to assume that the recurrent lesions are caused by dormant persisters which are originally drug sensitive. The recurrent skin lesions can not be classified because the clinical features can not be matched to their histology. Such recurrent cases might occur among the defaulters of MDT in future.

CTLA4 gene polymorphism correlates with the mode of onset and presence of ICA512 Ab in Japanese type 1 diabetes

Recently, the association of CTLA4 gene polymorphism with type 1 diabetes and AITD has been reported in several populations. CTLA4 was originally reported to regulate T-cell activity and T-B cognate interaction. To investigate the role of CTLA4 in autoimmune diseases, we examined the correlation between CTLA4 gene polymorphism and the clinical characteristics of Japanese patients with type 1 diabetes, including the mode of onset of diabetes and presence of islet-specific autoantibodies (GAD, ICA 512 Ab) in the serum. We studied 111 patients with type 1 diabetes and 445 normal subjects. CTLA4 exon 1 position 49 (A/G: codon 17: Thr/Ala) polymorphism was defined, employing PCR-RFLP. Sixty-three (57%) patients had AITD. The allele frequencies of G and A in both 111 patients (G: 65%; A: 35%) and 63 patients (G: 62%; A: 38%) were not significantly different from the control subjects (G: 63%; A: 37%). Serum samples of 69 patients were obtained within a year after onset and used for pancreas specific autoantibodies analysis. These samples were also used for further analysis between CTLA4 gene polymorphism and clinical characteristics. The allele frequencies of G and A in patients who presented with diabetic ketoacidosis (DK+) (G: 75%; A: 25%) were significantly different from those in DK- patients (G: 50%, A: 50%, P = 0.003). Allele and genotype analyses showed significant differences between DK+ patients and control subjects (P = 0.014, P = 0.046, respectively). Allele frequencies of G and A were not significant between patients who were positive and negative for GAD Ab, but significant for ICA 512 Ab (G: 83%, A:17% versus G: 59%, A: 41%: positive patients versus negative patients, P = 0.004). Our results showed a significant correlation between CTLA4 gene polymorphism and ICA 512 Ab. Our results also indicated that CTLA4 gene polymorphism is associated with the onset mode of Japanese type 1 diabetes and the presence of ICA512 Ab. Further analysis of this polymorphism is necessary to fully understand the pathogenesis and progression of type 1 diabetes.

Thermoregulatory thresholds for vasoconstriction in patients anesthetized with various 1-minimum alveolar concentration combinations of xenon, nitrous oxide, and isoflurane

BACKGROUND

Nitrous oxide limits intraoperative hypothermia because the vasoconstriction threshold with nitrous oxide is higher than with equi-minimum alveolar concentrations of sevoflurane or isoflurane, presumably because of its stimulating actions on the sympathetic nervous system. Xenon, in contrast, does not cause sympathetic activation. Therefore, the authors tested the hypothesis that the vasoconstriction threshold during xenon-isoflurane anesthesia is less than during nitrous oxide-isoflurane anesthesia or isoflurane alone.

METHODS

Fifteen patients each were randomly assigned to one of three 1-minimum alveolar concentration anesthetic regimens: (1) xenon, 43% (0.6 minimum alveolar concentration) and isoflurane, 0.5% (0.4 minimum alveolar concentration); (2) nitrous oxide, 63% (0.6 minimum alveolar concentration) and isoflurane 0.5%; or (3) isoflurane, 1.2%. Ambient temperature was maintained near 23 degrees C and the patients were not actively warmed. Thermoregulatory vasoconstriction was evaluated using forearm-minus-fingertip skin temperature gradients. A gradient exceeding 0 degrees C indicated significant vasoconstriction. The core-temperature threshold that would have been observed if skin had been maintained at 33 degrees C was calculated from mean skin and distal esophageal temperatures at the time of vasoconstriction.

RESULTS

The patients' demographic variables, preinduction core temperatures, ambient operating room temperatures, and fluid balance were comparable among the three groups. Heart rates were significantly less during xenon anesthesia than with nitrous oxide. The calculated vasoconstriction threshold was lowest with xenon (34.6+/-0.8 degrees C, mean +/- SD), intermediate with isoflurane alone (35.1+/-0.6 degrees C), and highest with nitrous oxide (35.7+/-0.6 degrees C). Each of the thresholds differed significantly.

CONCLUSIONS

Xenon inhibits thermoregulatory control more than isoflurane, whereas nitrous oxide is the least effective in this respect.

A new noninvasive method to measure blood pressure: results of a multicenter trial

BACKGROUND

Blood pressure (BP) monitoring with arterial waveform display requires an arterial cannula. We evaluated a new noninvasive device, Vasotrac (Medwave, Arden Hills, MN) that provides BP measurements approximately every 12-15 beats and displays pulse rate and a calibrated arterial waveform for each BP measurement.

METHODS

Surgical and critically ill patients (n = 80) served as subjects for the study. BPs, pulse waveforms, and pulse rates measured via a radial artery catheter were compared with those obtained by the Vasotrac from the opposite radial artery. Data were analyzed to determine agreement between the two systems of measurement.

RESULTS

Blood pressure measured noninvasively by the Vasotrac demonstrated excellent correlation (P<0.01) with BP measured via a radial arterial catheter (systolic r2 = 0.93; diastolic r2 = 0.89; mean r2 = 0.95). Differences in BP measured by the Vasotrac versus the radial arterial catheter were small. The mean+/-SD bias and precision were as follows: systolic BP 0.02+/-5.4 mm Hg and 3.9+/-3.7 mm Hg; diastolic BP -0.39+/-3.9 mm Hg and 2.7+/-2.8 mm Hg; mean BP -0.21+/-3.0 mm Hg and 2.1+/-2.2 mm Hg compared with radial artery measurements. The Vasotrac pulse rates were almost identical to those measured directly (r2 = 0.95). The Vasotrac BP waveform resembled those directly obtained radial artery pulsatile waveforms.

CONCLUSIONS

In surgical and critically ill patients, the Vasotrac measured BP, pulse rate, and displayed radial artery waveform, which was similar to direct radial arterial measurements. It should be a suitable device to measure BP frequently in a noninvasive fashion.

Autoantibodies to multiple islet autoantigens in patients with abrupt onset type 1 diabetes and diabetes diagnosed with urinary glucose screening

It has been reported that there is a heterogeneity in the clinical course of Japanese patients with type 1 diabetes. To elucidate the associations of expression of autoantibodies to multiple islet antigens with age of onset and mode of diagnosis of diabetes in Japanese patients with type 1 diabetes, autoantibodies against the protein tyrosine phosphatase-like molecules ICA512 (IA-2) and phogrin (IA-2beta) (ICA512/phogrin-A), GAD (GADA), insulin (IAA), and islet cell cytoplasm (ICA) were determined in sera from 73 Japanese patients with type 1 diabetes obtained within 14 days of diagnosis. Patients were divided into groups based on the age of onset (</=10 years, n=24 and >10 years, n=49) or the mode of onset (abrupt onset, n=59 and urinary screening identified, n=14). Of 73 new-onset patients with type 1 diabetes, 43 (59%) and 32 (44%) had ICA512A and phogrin-A levels exceeding the 99th percentile of 184 normal control subjects, respectively. Forty-five patients (62%) were positive for either ICA512A or phogrin-A. The frequencies for other autoantibodies were 71% for GADA, 48% for IAA, and 62% for ICA. The frequency of ICA512/phogrin-A was significantly higher in patients with an age of onset less than 10 years (83%) than in patients aged >10 years (51%, P<0.01). The positivity of ICA512/phogrin-A was less in patients whose diabetes was diagnosed by the urine glucose screening test (21%, P<0.001) than in abrupt onset patients (71%). Combined analysis (>/=1 antibody) of GADA, IAA, and ICA512/phogrin-A detected 88% of abrupt onset and 93% of screening-positive patients vs. 70% and 29%, respectively, for ICA (P<0.0005). These results indicate that the expression of ICA512/phogrin-A and cytoplasmic ICA is less in patients identified by urinary glucose testing but indicate that with combined autoantibody testing 90% of patients can be identified independent of the mode of diagnosis.

Intraoperative phenylephrine infusion decreases the magnitude of redistribution hypothermia

Core hypothermia during the first hour after induction of general anesthesia results largely from an internal core-to-peripheral redistribution of body heat. This redistribution results from both central inhibition of tonic thermoregulatory vasoconstriction in the arteriovenous shunt and anesthetic-induced vasodilation. We therefore tested the hypothesis that acute administration of phenylephrine, a pure alpha-adrenergic agonist, reduces the magnitude of anesthetic-induced core-to-peripheral redistribution of body heat. Patients undergoing minor oral surgery were randomly assigned to an infusion of 0.5 microgram.kg-1.min-1 phenylephrine i.v. or no treatment (control). The phenylephrine infusion was started immediately before anesthesia was induced with 2.5 mg/kg propofol i.v. Subsequently, anesthesia was maintained with sevoflurane and 60% nitrous oxide in oxygen. Calf minus toe, skin-temperature gradients < 0 degree C were considered indicative of significant arteriovenous shunt vasodilation. Ambient temperature and end-tidal concentrations of maintenance sevoflurane were comparable in each group. Although there were no significant differences in skin-temperature gradients, core temperatures in the untreated patients decreased significantly more (1.2 +/- 0.4 degrees C) than in those given phenylephrine (0.5 +/- 0.2 degree C, P < 0.001). These data suggest that maintaining precapillary vasoconstriction of blood vessels, not in the arteriovenous shunt reduces the magnitude of redistribution hypothermia.

IMPLICATIONS

Core hypothermia immediately after induction of general anesthesia results largely from core-to-peripheral redistribution of body heat. Core temperature reduction during the first hour of anesthesia decreased less in patients given phenylephrine than in untreated controls. These data suggest that maintaining precapillary vasoconstriction possibly reduces the magnitude of redistribution hypothermia.

Phospholipase A2 activity in ox-LDL-stimulated mesangial cells and modulation by alpha-tocopherol

BACKGROUND

Oxidized LDL increases the production of both prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) in rat mesangial cells. These increases were suppressed by antioxidants such as alpha-tocopherol (alpha-Toc) or probucol.

METHODS

We investigated the mechanism by which oxidized LDL leads to an increase in PGE2 production using rat mesangial cells in culture. We also examined how alpha-Toc supresses this augmentation, by measuring intracellular Ca2- and phospholipase A2 (PLA2) activity.

RESULTS

In rat mesangial cells, oxidized LDL increased PLA2 activity by increasing the intracellular calcium ion content, which resulted in the induction of PGE2 production. On the other hand, pretreatment of cells with alpha-Toc, which resulted in a large uptake of alpha-Toc in cell membranes, markedly suppressed the augmentation of PGE2 production and PLA2 activity by oxidized LDL in a dose dependent manner. However, cytosolic PLA2 partially purified from mesangial cells was not inhibited by alpha-Toc despite an increase of alpha-Toc.

CONCLUSION

These results suggest that the augmentation of PLA2 activity in mesangial cells by oxidized LDL in a result of oxidative stresses, and that the antioxidant action of alpha-Toc is responsible for the suppression of augmentation of PLA2 activity observed in mesangial cells exposed to oxidized LDL.

The effect of pyrogen administration on sweating and vasoconstriction thresholds during desflurane anesthesia

BACKGROUND

General anesthetics increase the sweating-to-vasoconstriction interthreshold range (temperatures not triggering thermoregulatory defenses), whereas fever is believed to only increase the setpoint (target core temperature). However, no data characterize thresholds (temperatures triggering thermoregulatory defenses) during combined anesthesia and fever. Most likely, the combination produces an expanded interthreshold range around an elevated setpoint. The authors therefore tested the hypothesis that thermoregulatory response thresholds during the combination of fever and anesthesia are simply the linear combination of the thresholds resulting from each intervention alone.

METHODS

The authors studied eight healthy male volunteers. Fever was induced on the appropriate days by intravenous injection of 30 IU/g human recombinant interleukin 2 (IL-2), followed 2 h later by an additional 70 IU/g. General anesthesia consisted of desflurane 0.6 minimum alveolar concentration (MAC). The volunteers were randomly assigned to the following groups: (1) control (no desflurane, no IL-2); (2) IL-2 alone; (3) desflurane alone; and (4) desflurane plus IL-2. During the fever plateau, volunteers were warmed until sweating was observed and then cooled to vasoconstriction. Sweating was evaluated from a ventilated capsule and vasoconstriction was quantified by volume plethysmography. The tympanic membrane temperatures triggering significant sweating and vasoconstriction identified the respective response thresholds. Data are presented as the mean +/- SD; P < 0.05 was considered significant.

RESULTS

The interthreshold range was near 0.40 degrees C on both the control day and during IL-2 administration alone. On the IL-2 alone day, however, the interthreshold range was shifted to higher temperatures. The interthreshold range increased significantly during desflurane anesthesia to 1.9+/-0.6 degrees C. The interthreshold range during the combination of desflurane and IL-2 was 1.2+/-0.6 degrees C, which was significantly greater than on the control and IL-2 alone days. However, it was also significantly less than during desflurane alone.

CONCLUSION

The combination of desflurane and IL-2 caused less thermoregulatory inhibition than would be expected based on the effects of either treatment alone. Fever-induced activation of the sympathetic nervous system may contribute by compensating for a fraction of the anesthetic-induced thermoregulatory impairment.

Isotype-specific changes in the amount of beta-tubulin RNA in synchronized tobacco BY2 cells

The 3'-ends of the beta-tubulin cDNA were amplified from tobacco BY2 polyA+ RNA. According to the differences in the predicted amino acid sequence at the extreme C-terminal, they were grouped into three different isotypes, NTB1 in which "EEGDYYEEDEEDLNEA", NTB2 in which "EEEYYEDEEEA QED" and NTB3 in which "DECEYEEEEEYDHEGN" follows the conservative "YQQYQDATAD" sequence. Using unique 3'-untranslated regions as probes, changes in the RNA levels of each beta-tubulin isotype were determined by dot-blot hybridization. The levels exhibited characteristic rhythms in the cell cycle. NTB1 RNA was highest in S phase in comparison to NTB2 RNA level which was highest in late G2. On the other hand, NTB3 RNA level was highest in early G2.