Hyperamylasemia and subclinical pancreatitis after cardiac surgery

Hyperamylasemia after cardiac surgery is common but typically causes no clinical concern because it consists mainly of the salivary isoenzyme. In this study we evaluated the incidence, source, and time course of postoperative hyperamylasemia with special attention to the possibility of subclinical pancreatitis. In 88 patients prospectively tested for serum amylase and lipase concentrations, elastase 1 activity, and amylase isoenzyme characteristics, 57 (64%) showed hyperamylasemia during the early postoperative period. In most cases early hyperamylasemia was not of pancreatic origin, but two patients were diagnosed with subclinical pancreatitis. Among the last 23 patients, 5 of 10 patients with early hyperamylasemia exceeding 1000 IU/L showed late hyperamylasemia on the seventh postoperative day, when it represented mainly the pancreatic isoenzyme. Lipase concentrations and elastase 1 activities were elevated in these cases. Late hyperamylasemia following cardiac surgery may be of pancreatic origin and indicative of subclinical pancreatitis, even if early hyperamylasemia was of salivary origin.

Guanylyl cyclase stimulatory coupling to K(Ca) channels

We coexpressed the human large-conductance, calcium-activated K (K(Ca)) channel (alpha- and beta-subunits) and rat atrial natriuretic peptide (ANP) receptor genes in Xenopus oocytes to examine the mechanism of guanylyl cyclase stimulatory coupling to the channel. Exposure of oocytes to ANP stimulated whole cell K(Ca) currents by 21 +/- 3% (at 60 mV), without altering current kinetics. Similarly, spermine NONOate, a nitric oxide donor, increased K(Ca) currents (20 +/- 4% at 60 mV) in oocytes expressing the channel subunits alone. Stimulation of K(Ca) currents by ANP was inhibited in a concentration-dependent manner by a peptide inhibitor of cGMP-dependent protein kinase (PKG). Receptor/channel stimulatory coupling was not completely abolished by mutating the cAMP-dependent protein kinase phosphorylation site on the alpha-subunit (S869; Nars M, Dhulipals PD, Wang YX, and Kotlikoff MI. J Biol Chem 273: 14920-14924, 1998) or by mutating a neighboring consensus PKG site (S855), but mutation of both residues virtually abolished coupling. Spermine NONOate also failed to stimulate channels expressed from the double mutant cRNAs. These data indicate that nitric oxide donors stimulate K(Ca) channels through cGMP-dependent phosphorylation and that two serine residues (855 and 869) underlie this stimulatory coupling.

How can Ca2+ selectively activate recoverin in the presence of Mg2+? Surface plasmon resonance and FT-IR spectroscopic studies

We investigated the relationship between metal ion selective conformational changes of recoverin and its metal-bound coordination structures. Recoverin is a 23 kDa heterogeneously myristoylated Ca(2+)-binding protein that inhibits rhodopsin kinase. Upon accommodating two Ca(2+) ions, recoverin extrudes a myristoyl group and associates with the lipid bilayer membrane, which was monitored by the surface plasmon resonance (SPR) technique. Large changes in SPR signals were observed for Sr(2+), Ba(2+), Cd(2+), and Mn(2+) as well as Ca(2+), indicating that upon binding to these ions, recoverin underwent a large conformational change to extrude the myristoyl group, and thereby interacted with lipid membranes. In contrast, no SPR signal was induced by Mg(2+), confirming that even though it accommodates two Mg(2+) ions, recoverin does not induce the large conformational change. To investigate the coordination structures of metal-bound Ca(2+) binding sites, FT-IR studies were performed. The EF-hands, Ca(2+)-binding regions each comprising 12 residues, arrange to coordinate Ca(2+) with seven oxygen ligands, two of which are provided by a conserved bidentate Glu at the 12th relative position in the EF-hand. FT-IR analysis confirmed that Sr(2+), Ba(2+), Cd(2+), and Mn(2+) were coordinated to COO(-) of Glu by a bidentate state as well as Ca(2+), while coordination of COO(-) with Mg(2+) was a pseudobridging state with six-coordinate geometry. These SPR and FT-IR results taken together reveal that metal ions with seven-coordinate geometry in the EF-hands induce a large conformational change in recoverin so that it extrudes the myristoyl group, while metal ions with six-coordinate geometry in the EF-hands such as Mg(2+) remain the myristoyl group sequestered in recoverin.

Moderate-intensity regular exercise decreases serum tumor necrosis factor-alpha and HbA1c levels in healthy women

OBJECTIVE

To evaluate the effects of moderate-intensity regular exercise on serum levels of tumor necrosis factor-alpha (TNF-alpha) and glucose and lipid metabolism parameters.

DESIGN

Longitudinal intervention study of a 5 month exercise training program (30-45 min/day, 4-5 days/week).

SUBJECTS

Forty-one healthy Japanese women aged 41-69 y at baseline; 27 participants in the exercise program.

MEASUREMENTS

Body mass index (BMI), waist-to-hip ratio (WHR), percentage body fat, and fasting levels for serum TNF-alpha, serum soluble TNF receptor p55 (TNF-RI) and TNF receptor p75 (TNF-RII), serum lipids, HbA1c, and serum insulin before and after exercise.

RESULTS

In overweight to obese subjects, serum levels of TNF-alpha, TNF-RI and TNF-RII were significantly higher than those in lean subjects. There were significant correlations between log serum TNF-alpha and BMI, percentage body fat, WHR, HbA1c and log insulin. TNF-RI was significantly correlated with BMI, percentage body fat, WHR and HbA1c. TNF-RII was also associated with BMI, percentage body fat and WHR. However, the correlation between TNF-RII and HbA1c did not reach statistical significance. Neither TNF-RI nor TNF-RII was correlated with log insulin. In contrast, TNF-alpha, TNF-RI and TNF-RII were negatively correlated with HDL cholesterol. Regular exercise decreased BMI, percentage body fat, HbA1c, serum TNF-alpha, TNF-RI and TNF-RII and increased HDL cholesterol levels. In addition, exercise-induced change in serum TNF-alpha was independently correlated with changes in HbA1c and serum insulin, after being adjusted for the change in fat-free mass.

CONCLUSION

Changes in serum TNF-alpha that occur with exercise may play an important role in improving glucose metabolism parameters.

Reciprocal changes in leptin and tumor necrosis factor-alpha with exercise in insulin resistant rats

Leptin and tumor necrosis factor--alpha(TNF-alpha) are important mediators of insulin resistance in obese subjects through their over-expression in adipose tissue. Secretion of leptin into the circulation is a signal for the brain in patients with hyperinsulinemia. Regulation of TNF-alpha affects adipocyte insulin sensitivity and lipid accumulation. Exercise training has been suggested for the prevention and treatment of such disorders. However, how exercise modifies secretion of leptin and TNF-alpha is not known. We investigated leptin and TNF-alpha in a rat model of insulin resistance induced by sucrose. After 4 weeks of sucrose feeding, 4 weeks of voluntary wheel running significantly reduced the concentrations of leptin in mesenteric (MS) and subcutaneous fat (SC) when compared to sedentary sucrose-feeding rats. These results suggest that exercise controls cytokine regulation of leptin and TNF-alpha. The increased TNF-alpha in adipose tissue may activate cytolysis for energy consumption.

Characterization of platelet-activating factor-induced cytosolic calcium mobilization in human eosinophils

BACKGROUND

Activated eosinophils play an important role in the pathogenesis of bronchial asthma and other allergic diseases, and platelet-activating factor (PAF) is a potent activator of eosinophils.

OBJECTIVE

To characterize the cytosolic Ca2+ ([Ca2+]i) mobilization in human eosinophils in response to PAF.

METHODS

[Ca2+]i responses to PAF were examined in human eosinophils using a microscopic fura-2 fluorescence-ratio imaging system.

RESULTS

PAF caused a significant and dose-dependent increase in (Ca2+)i, which consisted of an initial rapid rise followed by a sustained elevation. This PAF-induced (Ca2+)i rise was inhibited by WEB 2086, a specific PAF receptor antagonist. The addition of 5 mM EGTA or 1 mM Ni2+ to a nominally Ca2+-free solution did not appreciably reduce the initial rise but significantly inhibited the sustained rise. The application of a protein kinase C inhibitor, Ro31-8220, augmented the sustained increase by PAF. Thapsigargin, a microsomal Ca2+ ATPase inhibitor, induced no appreciable change in a nominally Ca2+-free solution but induced a marked increase in (Ca2+)i when changed to a Ca2+-containing solution.

CONCLUSIONS

The initial rapid rise and the following sustained rise in (Ca2+)i by PAF depends on Ca2+ release from the intracellular Ca2+ stores and Ca2+ influx, respectively, which are regulated by protein kinase C in human eosinophils. Furthermore, the so called Ca2+-capacitative entry is possibly involved in the Ca2+ influx from the extracellular solution in human eosinophils.

Suppression of maxi-K channel and membrane depolarization by synthetic polycations in single tracheal myocytes

Polycationic proteins, e.g., major basic protein from eosinophils or cathepsin G from neutrophils, have been shown to increase nonspecific airway responsiveness. Along with several indirect manners of action, polycations were reported to contract smooth-muscle strips and to raise the cellular Ca(2+) concentration as a direct action on airway smooth muscle. However, the mechanistic basis for the direct behavior remains to be elucidated. To address this issue, we examined the effects of synthetic cationic polypeptides poly-L-arginine and poly-L-lysine on fresh single smooth-muscle cells from bovine trachea using a patch-clamp technique. Both of the polycations significantly depolarized the membrane from a baseline of about -40 to -20 mV in a dose-dependent manner. The polycations also suppressed whole-cell spontaneous transient outward currents as well as both the conductance (from a baseline of about 130 to 70 pS) and open-state probability (about 25% of control values) of large-conductance Ca(2+)-dependent K(+) channel (maxi-K channel) on excised outside-out patch membranes. The polycations were without effect on the whole-cell Ca(2+) currents induced by depolarizing voltage pulses. We concluded that the synthetic polycations had at least two sites of action; one is the delayed rectifier K(+) channel that is responsible for the membrane depolarization that increases Ca(2+) influx, and the other is the maxi-K channel the suppression of which inhibits muscle relaxation. These results may explain the direct contractile action and, therefore, one of the mechanisms underlying the airway hyperresponsiveness induced by various polycationic proteins.

[A case of codon 232 mutation-induced Creutzfeldt-Jakob disease visualized by the MRI-FLAIR images with atypical clinical symptoms]

A 50-year-old man was admitted to our hospital because of disorientation and nocturnal restlessness. The patient presented chronically progressive dementia. No myoclonus or periodic synchronous discharge (PSD) was found over time, with abnormal evidence in MRI-FLAIR (fluid-attenuated inversion recovery) images alone. Brain biopsy and prion protein gene analysis led to the final diagnosis of Creutzfeldt-Jakob disease (CJD) induced by the point mutation at codon 232 (Met to Arg). To date the cases of M232R mutation-induced CJD have been reported to present clinical symptoms and pathological evidences similar to sporadic CJD cases, and differential diagnosis between the types has been believed to be difficult. Our case suggests that some types of CJD induced by point mutation at codon 232 cannot be easily inferred from clinical findings.

Assessment of between-instrument variations in a HPLC method for serum lipoproteins and its traceability to reference methods for total cholesterol and HDL-cholesterol

BACKGROUND

The main purpose of this study was to evaluate the between-instrument variation of the HPLC method for the measurement of total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), VLDL-cholesterol (VLDL-C), chylomicron cholesterol (CM-C), LDL size, and HDL size. Furthermore, the accuracy of the HPLC was assessed for the determination of TC and HDL-C, compared with CDC reference methods.

METHODS

We used four HPLC instruments with different column-load numbers from 250 to 5000. For accuracy assessment of TC and HDL-C, we used the reference methods recommended by the CDC.

RESULTS

The values measured by the four instruments were highly correlated with each other (mean r = 0.965), and the absolute mean differences were 4-43 mg/L for TC, 4-30 mg/L for HDL-C, 0-48 mg/L for LDL-C, 7-66 mg/L for VLDL-C, 0-7 mg/L for CM-C, 0.1-0.3 nm for LDL size, and 0-0.1 nm for HDL size. For TC, the HPLC instruments showed high correlation and good agreement with the reference method: r = 0.997; total error <6.6%; absolute mean bias <1.2%. For HDL-C, the results from the HPLC method were significantly higher (10.8% absolute mean bias) than those of the CDC reference method, in spite of good correlation between the two methods (r = 0.998).

CONCLUSIONS

The between-instrument variation in serum lipoprotein analysis by HPLC was confirmed to be very small. This method met the US National Cholesterol Education Program's performance criteria for TC but not for HDL-C.

Reduction of leptin precedes fat loss from running exercise in insulin-resistant rats

Serum concentrations of leptin, a hormone secreted into the circulation by adipocytes, correlate with body mass index. Circulating of leptin is thought to signal the brain in patients with hyperinsulinemia, a condition reported to be preventable and testable by exercise training. In the present experiments, sucrose-fed rats had reduced concentrations of leptin in portal venous blood after 4 weeks of nonforced wheel-running exercise (1.1 +/- 0.1 vs. 6.2 +/- 1.8 ng/mL, in nonexercised sucrose-fed rats, P < 0.05). Mesenteric and subcutaneous fat stores were similar between groups. After 12 weeks of exercise, portal vein levels of leptin concentrations (5.2 +/- 2.1 vs. 9.9 +/- 0.8 ng/mL, P < 0.05) and mesenteric and subcutaneous fat all were reduced in the exercise group. These results suggest that short-term running exercise reduces circulating leptin before any reduction of adipose mass, and this reduction in the concentration of leptin available to its receptors has beneficial effects on the metabolism of fat and carbohydrates.

Low-potassium University of Wisconsin solution for cardioplegia: improved protection of the isolated ischemic neonatal rabbit heart

Recovery of cardiac function and high-energy phosphates following ischemia and reperfusion were determined for hearts perfused with low potassium University of Wisconsin solution, high potassium University of Wisconsin solution, St Thomas' solution, or subjected to hypothermia alone. Isolated hearts were arrested for either 3 h at 15 degrees C or 6 h at 20 degrees C (n = 7 for each group) with one of the four solutions and then reperfused. Aortic flow after ischemic arrest at 20 degrees C was 40.3 +/- 13.3%, 79.3 +/- 10.0%, 64.3 +/- 11.9% and 43.9 +/- 15.9% of control values for high potassium University of Wisconsin solution, low potassium University of Wisconsin solution, St Thomas' solution and hypothermia alone, respectively. Similar results were observed in hearts subjected to ischemic arrest at 15 degrees C. Myocardial adenosine triphosphate and creatine phosphate after reperfusion tended to be higher in the low potassium University of Wisconsin solution group. It is concluded that low potassium University of Wisconsin solution may provide reliable cardioplegia during surgery that requires prolonged cardiac arrest in neonates and infants.

Experimental determination of the safe minimum perfusion flow rate for low-flow hypothermic cardiopulmonary bypass

This study investigated the safe minimum perfusion flow rate for low-flow hypothermic cardiopulmonary bypass in a canine model. The adequacy of cerebral oxygenation was determined from the adenosine concentration, the oxygen saturation of cerebral venous blood and brain oxyhemoglobin level. In experiment 1, nine beagles were cooled on bypass to a nasopharyngeal temperature of 18 degrees C and the perfusion flow rate was reduced in a stepwise fashion every 30 min from 100 to 50, 30, 20 and 10 ml/kg per min. In experiment 2, six beagles were cooled on bypass as in experiment 1, and flow was maintained at 30 ml/kg per min for 120 min. At a perfusion flow rate of 30 ml/kg per min, adequate cerebral oxygenation was maintained for 120 min. In contrast, perfusion flow rates of 20 and 10 ml/kg per min were associated with cerebral ischemia.

Running exercise increases tumor necrosis factor-alpha secreting from mesenteric fat in insulin-resistant rats

Tumor necrosis factor-alpha (TNF-alpha) is an important mediator of insulin resistance in obese subjects, through its overexpression in fat tissue. However, how exercise can modify the expression of TNF-alpha is controversial. We examined TNF-alpha in adipose tissue using an animal model of insulin resistance that was produced by feeding rats a diet high in sucrose. The rats were allocated to one of three groups: those receiving a starch-based diet (control group): those fed a high-sucrose diet (sucrose-fed group): and those fed a high-sucrose diet and given wheel exercise (exercised group). The animals were allowed to eat and drink ad lib for 4 or 12 weeks (4 wk: control n=7, sucrose-fed n=7, exercised n=10; 12 wk: control n=5, sucrose-fed n=5, exercised n=9). The voluntary wheel exercise was initiated with the feeding of the high-sucrose diet. The rats in the exercise groups ran 15 +/- 3 km/week. We showed that 12-week voluntary running exercise significantly (P<0.05) increased both TNF-alpha protein (5-fold) and mRNA (1.4 fold) in the mesenteric fat of insulin-resistant rats compared to non-exercised sucrose-fed mice. Accordingly, in exercised group, plasma glucose (124 +/- 9 mEq/L vs 141 +/- 11 mEq/L). and free fatty acid (0.98 +/- 0.07 mEq/L vs 1.4 +/- 0.05 mEq/L) concentrating in portal vein blood were reduced compared to sucrose-fed group. The amounts of fatty tissue both in mesenteric and subcutaneous tissues were significantly (P<0.05) decreased through running exercise. We consider that up-regulation of TNF-alpha in mesenteric fat may be a compensatory mechanism for the reduction of fatty acid in adipose tissues and this change could control metabolic homeostasis during exercise to modulate a hyperinsulinemic state.

Results of screening for cancer in Japanese in the prime of life--an analysis of nationwide MHTS and human dry dock statistics--Preventive Medicine Committee of the Japan Hospital Association

The nationwide survey of institutions with MHTS and human dry dock capabilities was analyzed and the following results have been obtained. 1) The relative rates of cancer detection by sex and organ were the stomach > colon > rectum > lung > kidney > esophagus for men and the stomach > breast > uterus > colon > thyroid > lung for women. 2) Gastric cancer takes first place in the ranking of rates of cancer detection in the population of both sexes, followed by colon cancer. The difference in rate of detection between these cancers has been narrowed from year to year. In 1997, the ratio of gastric to colon cancers was 10:7. 3) Early cancers account for 74% of gastric cancer patients and 75% of colon cancer patients. 4) Since gastric and colon cancers are detected early, the proportions of persons with gastrointestinal symptoms are as low as 28% for gastric cancer patients and 26% for colon cancer patients. 5) The relative rates of cancer detection by the degree obesity are normal > obese > lean person. The rates of gastric and colon cancers are 2- and 3-fold higher for obese persons than for lean persons, respectively. Gastric and colon cancers are detected with higher frequency in well-nourished persons. The present review of the national MHTS and human dry dock statistics has confirmed the efficacy of MHTS and human dry dock, especially in the examination for gastrointestinal cancers.

Cholinomimetic action of macrolide antibiotics on airway gland electrolyte secretion

We investigated the acute effects of erythromycin (EM) and its derivatives on ionic currents in airway glands from feline tracheae. Therapeutic concentrations of EM or clarithromycin (CAM) attenuated the whole cell currents evoked by ACh in a competitive manner. The maximally stimulated inward Cl- currents were reduced to 54 and 83% and the outward K+ currents to 55 and 84% of control values by EM and CAM, respectively, whereas the responses induced by phenylephrine, norepinephrine, caffeine, or ionomycin were unaffected by EM, CAM, or EM523, a synthetic derivative of EM. K+ channels in excised outside-out patches were not influenced by macrolides. Although therapeutic concentrations of macrolides showed no effect on the baseline currents, high concentrations of macrolides alone evoked currents mimicking the ACh response, which were abolished completely by atropine. We concluded that macrolides act as a partial agonist on cholinergic receptors, resulting in a reduction of Cl- secretion at pharmacological doses of the agents, which may exhibit a pronounced effectiveness on hypertrophied and/or cholinergically sensitized submucosal glands in pathological airways.

Effects of histamine and endothelin-1 on membrane potentials and ion currents in bovine tracheal smooth-muscle cells

We tested the effects of tetraethylammonium (TEA), acetylcholine (ACh), histamine, and endothelin-1 on single airway smooth-muscle cells from bovine trachea, using the patch-clamp technique. Resting membrane potential was -48 +/- 1 mV (n = 47). Both TEA and ACh significantly depolarized the membrane, by +28 +/- 4 mV (P < 0.001, n = 12) and +21 +/- 2 mV (P < 0.01, n = 7), respectively, in the whole-cell configuration. In contrast, both histamine and endothelin-1 hyperpolarized the membrane, by -21 +/- 6 mV (P < 0.01, n = 8) and -15 +/- 2 mV (P < 0.01, n = 8), respectively. Calcium-dependent large-conductance K+-channels (127 pS) and small-conductance K+ channels (21 pS) were identified in excised patches. The small-conductance K+ channel was inhibited by 4-aminopyridine and activated by both histamine and endothelin-1. Furthermore, TEA did not alter the membrane hyperpolarization by these agonists, suggesting that the small-conductance K+ channel or delayed-rectifier K+ channel was involved in the membrane hyperpolarization. Membrane hyperpolarization by histamine and endothelin-1 suggests that activation of voltage-dependent calcium channels (VDCCs) or of calcium influx does not contribute substantially to the contractile response of airway smooth-muscle contraction to these agonists.

Prolongation of total permissible circulatory arrest duration by deep hypothermic intermittent circulatory arrest

OBJECTIVE

We determined whether the duration of permissible circulatory arrest could be prolonged by deep hypothermic intermittent circulatory arrest.

METHODS

Twenty-five beagles were cooled on bypass to 18 degrees C to initiate deep hypothermia that was maintained for 3 hours. Five protocols were then studied: group 1, uninterrupted bypass during hypothermia; group 2, arrest for 40 minutes during hypothermia; group 3, arrest for 60 minutes during hypothermia; group 4, arrest for 80 minutes during hypothermia; and group 5, intermittent circulatory arrest, consisting of six cycles of 20 minutes of arrest followed by 10 minutes of systemic recirculation during hypothermia (total, 120 minutes of arrest). The oxyhemoglobin concentration in the brain was measured with near infrared spectrophotometry.

RESULTS

In groups 2, 3, and 4, the oxyhemoglobin concentration in the brain decreased continuously after arrest, finally reaching a plateau after 24.9 +/- 1.2 minutes. This finding suggested that the available cerebral oxyhemoglobin was depleted. In contrast, the available cerebral oxyhemoglobin was not depleted during hypothermic intermittent arrest in group 5. The mitochondrial respiratory control index was significantly lower in group 4 than in the other groups (p < 0.05). However, there were no significant differences in the respiratory control index for groups 1, 2, 3, and 5. Moreover, the formation of brain edema was significantly lower in group 5 than in the other groups (p < 0.05).

CONCLUSIONS

These results indicate that deep hypothermic intermittent arrest can increase the duration of total permissible circulatory arrest and will be a useful modality when prolonged arrest is anticipated.

Reconstitution of beta-adrenergic modulation of large conductance, calcium-activated potassium (maxi-K) channels in Xenopus oocytes. Identification of the camp-dependent protein kinase phosphorylation site

The human large conductance, calcium-activated potassium (maxi-K) channel (alpha and beta subunits) and beta2-adrenergic receptor genes were coexpressed in Xenopus oocytes in order to study the mechanism of beta-adrenergic modulation of channel function. Isoproterenol and forskolin increased maxi-K potassium channel currents in voltage-clamped oocytes expressing the receptor and both channel subunits by 33 +/- 5% and 35 +/- 8%, respectively, without affecting current activation or inactivation. The percentage of stimulation by isoproterenol and forskolin was not different in oocytes coexpressing the alpha and beta subunits versus those expressing the only the alpha subunit, suggesting that the alpha subunit is the target for regulation. The stimulatory effect of isoproterenol was almost completely blocked by intracellular injection of the cyclic AMP dependent protein kinase (cAMP-PK) regulatory subunit, whereas injection of a cyclic GMP dependent protein kinase inhibitory peptide had little effect, indicating that cellular coupling of beta2-adrenergic receptors to maxi-K channels involves endogenous cAMP-PK. Mutation of one of several potential consensus cAMP-PK phosphorylation sites (serine 869) on the alpha subunit almost completely inhibited beta-adrenergic receptor/channel stimulatory coupling, whereas forskolin still stimulated currents moderately (16 +/- 4%). These data demonstrate that physiological coupling between beta2 receptors and maxi-K channels occurs by the cAMP-PK mediated phosphorylation of serine 869 on the alpha subunit on the channel.

Deep hypothermic intermittent circulatory arrest--an adjunct technique for operations on aneurysms involving the aortic arch

Aneurysms involving the aortic arch were repaired in 12 patients using a technique known as deep hypothermic intermittent circulatory arrest (DHICA). This technique consists of repeated cycles of 20 min of circulatory arrest and 10 min of cerebral and systemic reperfusion. Aneurysms were of the following types: 2 true atherosclerotic aneurysm, 8 aortic dissections, and 2 traumatic aneurysm. There were 2 operative deaths caused by coagulopathy as a result of hepatic failure and difficulty with left ventricular venting. The frequency of circulatory arrest ranged from 2 to 5 cycles, and total circulatory arrest ranged from 20 to 71 min (mean 43.6 min). The lowest tympanic temperature ranged from 17.7 to 19.2 degrees C. No permanent cerebral complications occurred in 10 patients. We believe that this adjunct technique offers excellent results in the surgical treatment of aneurysms involving the aortic arch.

Combination of OK432 and human interferon-alpha for treating viral-induced diabetes mellitus in mice

We investigated the therapeutic effects of OK432 (picibanil; CAS39325-1-4), an immunomodulator that is derived from the Su strain of Streptococcus pyogenes. This agent was administered alone or combined with human interferon-alpha in a murine model of insulin-dependent diabetes mellitus. Interferon-alpha inhibits viral replication, reducing the incidence of virus-induced IDDM. Groups of DBA/2 mice (N = 25 per group) received an intraperitoneal injection of OK432 and interferon-alpha daily for 16 d beginning 1 d after inoculation with 500 plaque-forming units of encephalomyocarditis virus (EMCV). The dose of OK432 was one clinical unit (corresponding to 0.1 mg dried cells) per mouse, and that of interferon-alpha was 1 x 10(4) u/g. The animals were killed at random at 3 or 7 d after inoculation with EMCV. The survival rate of mice treated with the combination of OK432 and with interferon-alpha was significantly greater than that of the non-treated infected control animals (P < 0.01). Fasting levels of blood glucose were significantly lower in the mice administered the combination, than in the controls, both on day 3 (68 +/- 21 mg/dl vs. 270 +/- 135 mg/dl, P < 0.01) and on day 7 (101 +/- 29 mg/dl vs. 219 +/- 112 mg/dl, P < 0.01). Serum levels of insulin were significantly higher in the treated mice than in the controls (65 +/- 5 vs. 55 +/- 1 microU/ml, P < 0.05). However, in the mice treated with OK432 or interferon-alpha alone, the survival rate and the blood level of glucose and insulin did not differ from those of infected controls. Natural killer (NK) cell activity was significantly higher in the mice treated with the drug combination than in the controls on both days evaluated: day 3, 65 +/- 5 vs. 55 +/- 1%, n = 3, P < 0.05; day 7, 44 +/- 3 vs. 22 +/- 8%, n = 3, P < 0.05). Serum levels of murine interferon in the treated mice exceeded those in controls on both days evaluated (day 3, 671 U/ml vs. 442 U/ml; day 7, 57 U/ml vs. 43 U/ml). There were no significant differences in NK cell activity or in the interferon level in mice treated with either OK432 or interferon-alpha alone as compared with the infected, non-treated controls. Results suggest that the combination of OK432 and interferon-alpha protects against virally induced IDDM by increasing the activity of NK cells as well as the plasma level of interferon.

Fourier-transform infrared spectroscopic studies on the coordination of the side-chain COO- groups to Ca2+ in equine lysozyme

Interactions between Ca2+ and the Asp side chains in the Ca2+-binding site of equine lysozyme were investigated by Fourier-transform infrared (FT-IR) spectroscopy. In the spectrum of equine lysozyme, the intensities of the bands at about 1595 cm-1 and 1578 cm-1 in the region of the COO antisymmetric stretches increased upon Ca2+ binding. In the region of the COO- symmetric stretches, the loss of intensity at about 1388 cm-1 and gains of intensities at about 1423 cm-1 and 1403 cm-1 were observed due to Ca2+ binding to equine lysozyme. The spectral changes for equine lysozyme indicate that the COO- groups of Asp85, Asp90 and Asp91 in the Ca2+-binding site coordinate to Ca2+ in the pseudo-bridging mode, where divalent metal cation is bound to one of the two oxygens in the COO- group and a water molecule is hydrogen bonded to the other oxygen. The results presented here provide further evidence for a high degree of similarity between Ca2+-binding lysozyme and alpha-lactalbumin. The effects of Ca2+ binding on the main-chain conformation of equine lysozyme were compared with those of bovine alpha-lactalbumin and hen egg-white lysozyme.