A common group I intron between a plant parasitic fungus and its host

The self-splicing RNAs known as group I introns exist in many organisms, but their distribution is difficult to explain. We hypothesize that group I introns have been transferred between a parasite and its host. We describe here the discovery of a common group I intron sequence between a plant-parasitic fungus, Protomyces inouyei, and its host, Youngia japonica. It strongly supports our theory that the group I intron had been transferred from the host plant to the parasitic fungus in the course of evolution.

Long-term results of coronary artery bypass grafting in elderly Japanese patients

BACKGROUND

This study was undertaken to examine long-term results of coronary artery bypass grafting in elderly Japanese patients.

METHODS

Of 1,425 coronary artery bypass grafting patients over the last 13 years, 137 patients were 70 or more years old and 1,288 were less than 70 years old. Mean number of distal anastomoses was similar in both groups. Postoperative survival and event-free proportion were estimated by the Kaplan-Meier actuarial method and compared among the groups by Cox-Mantel statistical analysis.

RESULTS

Operative mortality and the incidence of late cardiac death after coronary artery bypass grafting were equivalent between the elderly and younger groups, although the rates of left main trunk disease, acute myocardial infarction, and emergency operation in the elderly group were significantly higher than those in the younger group. Coronary artery bypass grafting in elderly patients had a relatively high hospital mortality and more late noncardiac deaths, but the incidence of postoperative cardiac intervention in elderly patients was lower than that in younger patients.

CONCLUSIONS

These results suggest that coronary artery bypass grafting for elderly patients is encouraged as well as is that for younger patients in a representative Japanese population.

[Examination of cardiac myxomas complicated with embolism]

Cardiac myxomas complicated with embolism were examined. Of 51 patients who underwent surgical excision of myxomas during the last 19 years, 10 patients (6 patients originated from left atrium, 4 patients originated from right atrium) had complications by embolisms. The embolism occurred in cerebral arteries (5 cases), a coronary artery (1 case), a retinal artery (1 case), and pulmonary arteries (4 cases). Patients were divided into an embolism group and a non-embolism group to investigate risk factors of embolism. Arrhythmia, diameter, narrow peducle, and tumor friability were thought to be major risk factors. Gelatinous and rough surface type tumor tended to cause embolism. Hypervascular tumors did not cause embolism. Among 10 patients, 2 patients had already had new embolism and another 2 patients had aggravated their symptoms before making diagnosis of myxoma. Myxomas should always be considered as a source of embolization, which need meticulous investigation and prompt indication of surgical resection.

Flow study of surgical coronary artery fistula as an alternative to sequential bypass

Surgical coronary artery fistula, in which the last anastomosis is created to a low-pressure cardiac chamber, was recently introduced as an alternative method to improve graft flow and patency in a sequential graft when coronary arteries are small or diffusely diseased. To assess graft flow, effect on haemodynamics, flow distribution and to determine proper size of the distal anastomosis, a saphenous vein was sequentially anastomosed from the ascending aorta to the left anterior descending artery and then to the left atrium in eight mongrel dogs. Graft flow was measured before and after opening the fistula to the left atrium between the ascending aorta and left anterior descending artery (flow A) and between the left anterior descending artery and left atrium (flow B). Left atrium pressure and systolic left ventricular pressure (mmHg) were recorded. The diameter of the distal anastomosis was regulated with a bulldog clamp. When distal anastomosis was at 2.5-3 mm mean(s.d.) flow A increased from 64.5(19.5) to 134.7(28.5) ml/min (P < 0.01) without significant left atrial pressure or left ventricular pressure change. With a distal anastomosis of 4 mm or more, flow A increased from 69.8(19.9) to 396.1(62.2) ml/min (P < 0.001). Left atrial pressure increased from 5.6(1.0) to 6.1(0.9) mmHg (P < 0.05) without a change in left ventricular pressure. In both sizes of distal anastomosis, flow to the left anterior descending artery did not change either before or after the shunt (flow B) was opened. Neither volume loading, rapid atrial pacing, neosynephrine or epinephrine infusions caused deleterious haemodynamic effects with the shunt open.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of an autoflow cruise control system for a centrifugal pump

To improve the ease of driving a centrifugal pump that is afterload dependent, we have developed an automatic flow control system for the Terumo Capiox centrifugal pump system. This system consists of an autoflow cruise control system with a safety cutoff. The Capiox Pump Console 3000 was controlled by a personal computer through a serial communication line. In the usual manual mode, the motor speed knob works as a pump speed control, and in the autoflow mode, the same knob works as a blood flow rate control. After selecting and obtaining the desired flow rate, the mode was changed from manual to autoflow mode. In the autoflow mode, the computer compares the desired flow rate with the actual flow measured by an ultrasonic Doppler flowmeter and adjusts the motor rotational speed accordingly. During both in vivo and in vitro testing, this autoflow mode was able to return the changed flow that was disrupted by either clamping and declamping of the tubing or by the bolus injection of a vasomotor drug to the selected flow rate within 10 s without any significant fluctuation. In conclusion, the newly developed computer controlled autoflow system was able to produce a reliable and effective flow regulation for a centrifugal pump.

Generation of novel rapamycin structures by microbial manipulations

A new rapamycin producing culture was isolated and designated as Actinoplanes sp. N902-109. The addition of a cytochrome P-450 inhibitor and precursor feeding using this culture, and biotransformation approaches generated new rapamycin analogs with modifications at C-4, C-9, C-16, C-27, C-28 and/or C-39. The immunosuppressive activity of the resulting analogs was established in the mixed lymphocyte reaction assay.

Current strategy for severe heart failure with mechanical circulatory support

In the last 10 years, 37 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 12 patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB), and the remaining 4 received a left ventricular assist device (LVAD). Weaning and discharge rates of the patients by type of circulatory supports were 41.7 and 25.0% with VAB, 69.3 and 46.2% with BVB, 87.5 and 37.5% with LVB, 75.0 and 50.0% with LVAD, and 44.4 and 11.1% with PCPS, respectively. Concerning complications of postcardiotomy circulatory support, hemorrhage and ventricular arrhythmia postcardiotomy circulatory support, hemorrhage, and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports (i.e., LVB, LVAD). However, profound biventricular failure, infection, and multiple organ failure remain as possible complications with any type of assisted circulation. These results suggest that early application of circulatory support and appropriate selection of the mode of support and devices used are important for successful circulatory support.

[Flow competition of right gastroepiploic artery graft in coronary artery bypass surgery]

We evaluated the competitive flow between the right gastroepiploic artery (RGEA) and native coronary artery in coronary artery bypass surgery with respect to anastomosis in a retrograde fashion and the relationship of the degree of proximal stenosis with the flow dependency. The RGEA has been used in 157 patients and was anastomosed in a retrograde fashion in 22 patients. There was no significant difference between the retrograde anastomosis and the antegrade anastomosis on revascularization to the left anterior descending coronary artery in terms of diameter (2.0 +/- 0.5, 1.68 +/- 0.2 mm), flow (21.8 +/- 13.2, 24.5 +/- 19.4 ml/min), early patency (100%, 100%) and string sign (0%, 0%). We examined angiographically the relationship between the preoperative degree of proximal stenosis and postoperative pattern of flow dependency in the right coronary artery distal to the RGEA anastomosis in 98 patients. With a proximal stenosis of 75% (n = 19), RGEA occlusion was observed in two patients (11%), native coronary-dependent flow in four (21%), balanced flow in nine (47%) and RGEA-dependent flow in four (21%). With a proximal stenosis of 90% (n = 16), native-dependent flow was observed in one (6%), balanced flow in six (38%) and RGEA-dependent flow in nine (56%) patients. With a proximal stenosis of 99%-100% (n = 63), RGEA occlusion was observed in three (5%) and RGEA-dependent flow in sixty (95%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Pyripyropenes, Novel ACAT inhibitors produced by Aspergillus fumigatus. III. Structure elucidation of pyripyropenes E to L

Eight new pyripyropenes, E to L, were isolated from the culture broth of Aspergillus fumigatus FO-1289-2501 selected as a higher producer by NTG mutation. Structural elucidation indicated that all the pyripyropenes have the same pyridino-alpha-pyrone sesquiterpene core as pyripyropenes A to D. Among them, pyripyropene L showed the most potent inhibition against acyl-CoA: cholesterol acyltransferase (ACAT) activity with an IC50 value of 0.27 microM in rat liver microsomes.

Serum N-acetyl-beta-D-glucosaminidase activity in predicting the development of hypertension

We conducted a prospective study in residents of a small farming community in southwestern Japan to determine whether elevated serum N-acetyl-beta-D-glucosaminidase (NAG) activity would predict future hypertension. The 505 normotensive subjects (blood pressure, < 140/90 mm Hg; mean age, 52 +/- 12 years) were reexamined after 7 years; 111 (22%) had become hypertensive (defined as blood pressure > or = 140/90 mm Hg and/or taking antihypertensive medication at follow-up). After adjustment for age and sex, the development of hypertension was significantly related to body mass index (P < .002), the sum of skinfolds (P < .001), baseline blood pressure (P < .0001), serum cholesterol (P < .01), serum uric acid level (P < .0001), and serum NAG activity (P < .005). Elevated NAG activity showed an independent relationship to future hypertension (P < .005) after adjustments for age, sex, baseline blood pressure (systolic, diastolic, or mean), uric acid level, and the sum of skinfolds. Therefore, elevated serum NAG activity was an effective indicator of future hypertension, and it might therefore be related to functional and/or structural changes in the cardiovascular system.

Abnormal cardiac histology in severe intrauterine growth retardation infants

Four infants with severe intrauterine growth retardation (IUGR) weighing less than 1000 g at birth developed heart failure and died in our unit, where heart failure of IUGR infants is the main reason of death in extremely low birth-weight infants. The causes of their heart failure are one of the main themes in current neonatal medicine. The subjects of this study were four small for gestational age infants; all died due to heart failure 5 to 10 days after birth. Microscopic specimens of hearts from autopsies were evaluated with respect to the following characteristics: thickness of myocardial fibers, maturation of nuclei, presence of dysgenesis or necrosis in myocardium, and amount of glycogen in the heart. Neither dysgenesis nor infarction of the heart was found but hypoplasia in myocardial fibers and decreased glycogen levels were observed. Maturation delay in myocytes' nuclei did not appear to be severe. We conclude that these infants' hearts failed to adapt to postnatal hemodynamic changes because of inadequate myocardial function and inadequate glycogen reserves.

Evoked otoacoustic emissions and electrocochleography in a patient with multiple sclerosis

A 24-year-old woman with multiple sclerosis had right-sided hearing impairment with tinnitus. She underwent electrocochleography (ECochG) and examination of evoked otoacoustic emissions (EOAEs) to assess cochlear function. An acoustic probe to measure EOAEs was inserted into the external ear canal. The ECochG action potential and cochlear microphonics were recorded by a transtympanic needle electrode technique. Both fast and slow components of EOAEs appeared in either the period of deteriorated hearing acuity or when it was improved. They showed normal detection thresholds and input-output curves during both periods. Cochlear microphonics with almost normal detection thresholds and input-output functions were obtained during the period of deteriorated hearing acuity. Action potential (N1) input-output curves during relapse with hearing loss were notably lower in amplitude and longer in latency than those obtained at the time hearing impairment showed improvement. The EOAE and ECochG findings suggested that this patient had almost normal cochlear function, and we assumed from the magnetic resonance imaging and auditory brain stem response findings as well as the ECochG that the hearing impairment was caused by dysfunction of auditory pathways in the brain stem, including structures that contribute to generation of the N1 potential of the ECochG.

[Cochlear microphonic potential (CM) recordable at non-shielded bedside--with reference to the development of a new earphone (NC-3)]

By making several improvements in current hearing aid earphones, a new earphone (NC-3) for CM measurement in electrocochleography (ECochG) has been developed. A silicone tube with a 1.5mm inside diameter, 175mm in length, was attached to the acoustic hole side of the earphone. The earphone proper was shielded with aluminum foil and one end of the foil was connected to a low noise cable. Human forearm was used as a dummy ear and the electrode HN-5 was fixed thereon, and a sound stimulus of 90dBnHL was delivered by the earphone (NC-3). No measurable artifacts, such as electromagnetic conductions and the CM-like mechanical vibrations generated by the acoustic output system, were recorded. By placing the earphone (NC-3) from a right-angle to a diagonal direction toward the electrode circuit, electromagnetic conduction contamination was prevented. With an extratympanic procedure using the electrode HN-5, ECochG-CM was recorded from normal hearing subjects in both a shielded sound-proof room and a non-shielded ordinary but quiet room. Short tone bursts at 1 and 4kHz were employed as acoustic stimuli and delivered by the earphone (NC-3). In the non-shielded quiet room, no electromagnetic conduction contamination or mechanical vibration was observed and there were no differences in CM responses between the two rooms. These results suggest that this earphone (NC-3), making CM recordings possible at the ordinary bedside without shielding, may contribute significantly to the subsequent spread of ECochG-CM measurement, by compensating for the disadvantages of a loudspeaker.

Embolization of the hepatic falciform artery to prevent supraumbilical skin rash during transcatheter arterial chemoembolization for hepatocellular carcinoma

A dilated hepatic falciform artery (HFA) arising from the left hepatic artery was demonstrated on arteriography prior to chemoembolization of an unresectable hepatocellular carcinoma (HCC) located predominantly in the left lobe of the liver. The HFA was occluded by microcoils to prevent a possible toxic supraumbilical skin rash following chemoembolization of the HCC via the left hepatic artery. There were no postprocedure complications. We consider this procedure useful for improving the safety of chemoembolization.

[Evaluation of anastomosis between intrahepatic or extrahepatic vessels by intra-arterial digital subtraction angiography using carbon dioxide]

Carbon dioxide (CO2) intraarterial subtraction angiography (IADSA) was performed in 31 patients with various hepatobiliary diseases. The injection sites of CO2 were proper hepatic artery (10/31; group A), segmental hepatic artery (18/31; group B), and peripheral inferior phrenic artery (3/31; group C), respectively. In group A, only the third order branches of the portal venous system were visualized anterogradely in 8 of 10 patients. In group B, the microcatheter was placed coaxially through a 5 French guiding catheter at the main arterial supply of the tumor in 7 patients and at the peripheral segmental branch of the hepatic artery in 11 patients. The portal venous system was visualized retrogradely in all of the patients regardless of the injection site. The injected CO2 may flow back into the portal vein through the anastomosis known as the peribiliary or periportal plexus. In group C, not only the portal vein but also the pulmonary artery or pericardial vein were visualized by this method. CO2-IADSA was useful to image the minute communications between the various vessels, which have been not hitherto visualized by iodinated contrast medium.

Oxygenator with built-in hemoconcentrator: a new concept

A hemoconcentrator is an instrument essential for open heart surgery without blood transfusion. In order to simplify the extracorporeal blood circuit and to facilitate handling of cardiopulmonary bypass, we have combined a hollow fiber unit for gas exchange and that for hemofiltration into one component and developed a new membrane oxygenator with the function of a hemoconcentrator. The cylindrical device consists of a hollow fiber for hemofiltration with another fiber for gas exchange provided outside. Both of them adopt the blood outside perfusion system. Blood enters and flows through the central hole for hemofiltration and then flows into the oxygenator. By applying the flow mode to the device, blood is allowed to flow from the center of the core toward the hollow fiber around it. Therefore, even distribution of blood flow to the entire fiber is realized, and the performance of the device is improved. The oxygen transfer rate was 317 ml/min at a flow rate of 6 L/min, and the ultrafiltration rate was 7 L/h at a flow rate of 4 L/min with a hematocrit of 25%. The combined structure of the two units has not caused any adverse effects. In conclusion, by combining an oxygenator and a hemoconcentrator, excellent and simplified hemoconcentration is made available as the blood outside flow mode is adopted, which is one of the unique aspects of this device.

Effects of fatty acyl coenzyme A esters on lipoxygenase and cyclooxygenase metabolism of arachidonic acid in rabbit platelets

The effects of fatty acyl coenzyme A (CoA) esters (palmitoyl-, stearoyl-, oleoyl-, linoleoyl- and arachidonoyl--CoA) on the activities of lipoxygenase and cyclooxygenase in rabbit platelets were examined. Palmitoyl-, stearoyl-, oleoyl- and linoleoyl- CoA were potent inhibitors of platelet lipoxygenase activity. In addition to the lipoxygenase, the four fatty acyl-CoA esters elicited inhibitory activity on platelet cyclooxygenase, although the inhibition was a little weaker. The CoA derivative of the icosanoid precursor arachidonic acid (AA) showed little inhibition on lipoxygenase and cyclooxygenase. Palmitic, stearic and oleic acids had little or no effect on lipoxygenase and cyclooxygenase, in contrast with their CoA derivatives. Linoleic acid was more potent than linoleoyl-CoA as an inhibitor of the cyclooxygenase, but it was a weak inhibitor of the lipoxygenase. These results suggest that the CoA derivatives of palmitic, stearic, oleic and linoleic acids have the potential to modulate both platelet lipoxygenase and cyclooxygenase activities and may have functional effects within platelets.

Inhibitory effect of Mg2+ on the protonophoric activity of palmitic acid

To discriminate whether fatty acids are uncouplers that cause acceleration of State-4 respiration, associated with a decrease in the protonmotive force, or decouplers that increase respiration without associated decrease in the protonmotive force, we examined the effect of palmitate on functions of rat-liver mitochondria under various conditions. We found that palmitate itself increases State-4 respiration, releases oligomycin-inhibited State-3 respiration, inhibits ATP synthesis and ATP<->Pi exchange reaction, and increases H+ permeability in mitochondrial and model bilayer phospholipid membranes. Thus, palmitate is a classical uncoupler of oxidative phosphorylation. However, these effects were inhibited by Mg2+, due to rapid formation of a stable complex between palmitate and Mg2+.

Specific arrangement of three amino acid residues for flavin-binding barrel structures in NADH-cytochrome b5 reductase and the other flavin-dependent reductases

The structure of NADH-cytochrome b5 reductase from pig liver microsomes has been refined to a crystallographic R factor of 0.223 at 2.4 A resolution. A structural comparison between the flavin-binding beta barrel domain of NADH-cytochrome b5 reductase and those of the other flavin-dependent reductases, ferredoxin-NADP+ reductase, phthalate dioxygenase reductase and nitrate reductase, indicated that the overall barrel foldings are similar to each other and that the specific arrangement of three amino acid residues (Arg, Tyr and Ser/Thr) is usually necessary for flavin-binding. These conserved residues overlap each other in their three-dimensional structures and stabilize the flavin-binding site in the four flavin-dependent reductases.

Crystal structure of NADH-cytochrome b5 reductase from pig liver at 2.4 A resolution

The three-dimensional structure of NADH-cytochrome b5 reductase from pig liver microsomes has been determined at 2.4 A resolution by X-ray crystallography. The molecular structure reveals two domains, the FAD binding domain and the NADH domain. A large cleft lies between these two domains and contains the binding site for the FAD prosthetic group. The backbone structure of the FAD binding domain has a great similarity to that of ferredoxin-NADP+ reductase [Karplus, P. A., Daniels, M. J., & Herriott, J. R. (1991) Science 251, 60-65], in spite of the relatively low sequence homology (about 15%) between the two enzymes. On the other hand, the structure of the NADH domain has several structural differences from that of the NADP+ domain of ferredoxin-NADP+ reductase. The size of the cleft between the two domains is larger in NADH-cytochrome b5 reductase than in ferredoxin-NADP+ reductase, which may be responsible for the observed difference in the nucleotide accessibility in the two enzymes.

[Renal arterial embolization with iohexol-ethanol solution: an experimental study]

Experimental renal arterial embolization was undertaken with ethanol-iohexol solution in 17 mongrel dogs. Post embolization arteriography revealed that ethanol-iohexol solution and absolute ethanol were almost equal in embolic effect. With this solution, the interventional approach can be made much more easily and safely.

[Experimental study on organ perfusion by intraaortic balloon counterpulsation with double balloon catheter]

Newly-developed catheter for the intraaortic balloon counterpulsation with cardio-renal assist was examined on animal model. The catheter consists of two balloon segments between which the celiac trunk, the superior mesenteric artery and the renal artery are to be placed. Statistical comparison on each hemodynamic element was carried out between the catheter (DBC), conventional single balloon catheter (SBC) of the same balloon volume as DBC and no assist (None) groups. There were no significant changes between SBC and DBC in cardiac output, femoral arterial flow and central venous pressure. Renal arterial flow and urinary output were significantly increased in DBC (None 14.4 +/- 3.9, SBC 22.6 +/- 5.6, DBC 31.0 +/- 6.9 ml/min in renal arterial flow, None 33 +/- 9, SBC 64 +/- 14, DBC 78 +/- 20 ml/h in urinary output, p < or = 0.05). After the remodeling adjust to the human stature, a clinical application would be considered.

Current strategy of circulatory support for profound heart failure

The purpose of this study is to assess the current strategy of mechanical circulatory support for profound heart failure. In the last 10 years, 37 patients with profound heart failure underwent mechanical circulatory support after open heart surgery and 9 patients with non-cardiotomy cardiogenic shock received emergency circulatory support. All patients showed severe cardiac failure and/or fatal ventricular arrhythmia and required circulatory support as a life-saving measure. After cardiovascular surgery, 12 of those patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB) and the remaining 4 patients received left ventricular assist device (LVAD). And 9 patients with non-cardiotomy cardiogenic shock received percutaneous cardiopulmonary support (or PCPS) as an emergency assist system. Weaning and discharge rates of the patients by the type of circulatory supports were 41.7% and 25.0% with VAB, 69.3% and 46.2% with BVB, 87.5% and 37.5% with LVB, 75.0% and 50.0% with LVAD, and 44.4% and 11.1% with PCPS, respectively. Clinical results of post-cardiotomy circulatory support (64.9% of weaning and 37.8% of discharge) were acceptable, but the patients with non-cardiotomy cardiac failure needed early application of more advanced circulatory support.