Changes in ultra-low and very low frequency heart rate variability after coronary artery bypass grafting

This study was performed to assess the effects of coronary artery bypass grafting (CABG) on the ultra-low (ULF) and very low (VLF) frequency components of heart rate variability (HRV). Forty-nine CABG patients (aged from 38 to 77 years) were examined by 24-h ambulatory electrocardiographic (AECG) monitoring, both preoperatively and 4 weeks after CABG. HRV spectral components were obtained by maximum entropy method analysis. Then the ULF, VLF, low frequency (LF), high frequency (HF) and total frequency (TF) components were compared before and after CABG. The average 24-h heart rate increased significantly after CABG (69+/-11.5 vs 82.9+/-10.9 beats per minute [bpm], P < 0.0001). The power of the ULF, VLF, and LF spectral components showed a decrease after surgery (2,859.9 vs 1,601.2 ms2, P<0.0001, 1,215.0 vs 572.3 ms2, P<0.0001, and 260.3 vs 125.9 ms2, P< 0.002, respectively), but the HF power did not show any significant change (98.7 vs 125.9 ms2, NS). Analysis of the normalized ratio of the ULF component (ULF/TF ratio) revealed a significant increase postoperatively (0.6496+/-0.0931 vs 0.7003+/-0.1338, P < 0.0001), but the VLF/TF and LF/TF ratios decreased after CABG (from 0.2671+/-0.0689 to 0.2040+/-0.0832, P< 0.0001 and from 0.0568+/-0.0290 to 0.0429+/-0.0232, P< 0.0088, respectively). In contrast, there was no significant alteration in the HF/TF ratio. These results suggest that recovery of cardiac autonomic activity is delayed after surgery. However, improvement of the ULF/TF ratio, one of the prognostic indicators for patients with cardiac disease, should be related to the relief of myocardial ischemia by CABG.

Identification of GFAT1-L, a novel splice variant of human glutamine: fructose-6-phosphate amidotransferase (GFAT1) that is expressed abundantly in skeletal muscle

Glutamine:fructose-6-phosphate amidotransferase (GFAT1) is the rate-limiting enzyme in the hexosamine biosynthetic pathway, which plays an important role in hyperglycemia-induced insulin resistance. To evaluate the role of GFAT1 expression, we analyzed the expression profiles of GFAT1 mRNA in various human tissues using reverse transcriptase-polymerase chain reaction. We report here the identification and cDNA cloning of a novel GFAT1 splice variant expressed abundantly in skeletal muscle and heart. This subtype, designated GFAT1-L, contains a 54-bp insertion within the GFAT1 coding sequence. Recombinant GFAT1-L protein possessed functional GFAT activities and biochemical characteristics similar to GFAT1. Previously, GFAT1 was considered a simplex enzyme. The identification of a novel GFAT1 subtype possessing functional enzymatic activity and tissue-specific expression should provide additional insight into the mechanism of skeletal muscle insulin resistance and diabetes complications.

[Coronary artery bypass-grafting using interrupted anastomosis with the U-clip]

For coronary artery anastomosis, the continuous suture technique is generally used because it is easy to perform, there is less anastomotic leakage, and a shorter anastomotic time compared with the interrupted suture technique. However, with this technique there is a potential risk of anastomotic stenosis caused by the purse-string effect, which does not occur with the interrupted suture technique. The U-Clip device was designed to facilitate the interrupted suture technique in coronary anastomosis by eliminating the need for suture management, knot tying, and surgical assistance. The device employs the superelastic properties of nitinol and two components: 1. a needle/suture delivery system, and 2. a detachable nitinol self-closing wire. We used this device successfully for LITA-LAD anastomosis in MIDCAB. When this device is applied to small caliber conduits, such as the internal thoracic arteries and the gastroepiploic artery, the side-to-side anastomosis can reduce the anastomotic leakage more efficiently, since the coronary incision and graft incision can be perfectly matched. The U-Clip facilitates coronary anastomosis by simplifying and decreasing the amount of manipulation and complexity required in minimally invasive CABG procedures. Nitinol technology also has potential in robotic and endoscopic surgical applications.

Enhancement of phase separation using a drop coalescer in an aqueous two-phase system

The effect of a drop coalescer on phase separation in a PEG/salt aqueous two-phase system (ATPS) in the absence and presence of protein has been investigated. Raschig rings of ceramic, PTFE and glass were used as a drop coalescer in order to separate the mixture into two phases. Among the three materials PTFE is the most effective in coalescing the dispersed drops, with the throughput with PTFE being twice that without the coalescer. Random packing gives good results for phase separation. Two types of fiber mesh coated with PTFE were also used as drop coalescers, one in a spirally folded form and the other in a three-dimensional lattice-form. Throughput in the PEG/salt system with the three-dimensional lattice-form is 1.2 times as high as that with the spirally folded form. Throughput with the coalescer formed by compiling PTFE Raschig rings and fiber mesh in lattice form is 1.6 and 1.2 times as high as the case of separate use of the fiber mesh and the PTFE Raschig rings, respectively. The hydrophobic surface of PTFE in the compiled coalescer has no significant effect on the recovery fraction of the protein in ATPS.

Coexistence of lung cancer and hamartoma

We present a rare case of a synchronous primary lung cancer adjacent to a hamartoma. A 71-year-old woman was admitted with congestive heart failure due to acute myocardial infarction. A chest radiogram on admission showed pulmonary edema with a tumor shadow in the right upper lung field. Because histological diagnosis was not obtained preoperatively, a wedge resection of the lung was conducted using video-assisted thoracoscopic surgery. The histopathological examination confirmed the coexistence of an adenocarcinoma with a chondromatous hamartoma. Right upper lobectomy was performed followed by excision of the mediastinal lymph nodes. Although hamartoma is generally considered to be a benign neoplasm, there have been several reports of increased risk to lung cancer in patients with a chondromatous hamartoma. Therefore, we recommend that patients with a hamartoma should be submitted to a complete evaluation and to regular follow-up, considering the risk to associated synchronous malignancy.

[The effect of celiprolol hydrochloride for lipid metabolism--especially for the low density lipoprotein particle size]

Recently, much attention has been paid to small sized low density lipoprotein (LDL) as a risk factor for ischemic heart disease. We investigated the effect of celiprolol hydrochloride (CH), which is a beta 1 selective beta-blocker with high intrinsic sympathomimetic activity (ISA), on the LDL particle size. We treated 41 hypertensive patients with CH and studied the change in LDL particle size according to the score of fast beta lipoprotein and LDL relative mobility value (LDL-Rm) measured by lipoprotein polyacrylamide gel disc electrophoresis (PAGE). We also studied changes in blood pressure, total cholesterol (TC), trygiyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and midband on PAGE. Systolic and dyastolic blood pressure and pulse significantly decreased during treatment. TC levels were significantly decreased at 8 weeks in all subjects and at 4, 8 and 12 weeks in patients with a TC value of over 220 mg/dl. TG levels were significantly decreased at 4 and 8 weeks in patients with initial levels of over 150 mg/dl, and significantly increased at 4 and 8 weeks in those with initial levels of under 150 mg/dl of TG. HDL-C levels did not significantly change during treatment. LDL-C levels were significantly decreased at 4, 8 and 12 weeks in patients with initial levels of over 150 mg/dl. Apo AI, AII, B, CII, CIII and E levels did not significantly change during treatment. Fast beta lipoprotein scores did not significantly change overall during treatment, but were significantly decreased at 4 and 8 weeks in patients initial TG levels of over 150 mg/dl and at 4 and 12 weeks in those with initial levels of over 220 mg/dl of TC. LDL-Rm scores did not significantly change during treatment. Midband scores were significantly reduced overall at 8 weeks, and after 4 and 8 weeks in patients with initial TG levels of over 150 mg/dl and at 4, 8 and 12 weeks in those with initial TC levels of over 220 mg/dl. These results indicated that CH did not change LDL particle size. It was suggested that CH might be a beneficial beta-blocker from the standpoint of prevention for atherosclerosis.

[Inferior mini-sternotomy for off-pump CABG using bilateral internal thoracic arteries]

Case 1: A 72-year-old woman with effort angina underwent coronary artery bypass grafting. A preoperative coronary angiogram showed 90% stenosis in the proximal main RCA, and total occlusion in the proximal LAD, distal of which was an area well supplied by collaterals from the RCA. This patient had previously undergone right upper lobectomy due to lung cancer. With a skin incision of 8 cm, the LITA was inserted into the LAD and the RITA was inserted into the mid RCA through an inferior mini-sternotomy while the heart was beating. Case 2: A 69-year-old man with effort angina underwent CABG. A preoperative coronary angiogram showed 90% stenosis in the proximal main RCA, 75% stenosis in the PDA and total occlusion in the proximal LAD, distal of which was an area well supplied by collaterals from the RCA. With a skin incision of 11 cm, the LITA was inserted into the LAD, the RITA into the mid-RCA and the radial artery graft attached to the RITA was grafted to the PDA through an inferior mini-sternotomy while the heart was beating. In both cases, the sternum was not cut transversely in order to prevent injury to the ITAs and pseudo-joint formation. With the use of this technique, exposure of the LAD and RCA was excellent. Postoperative recovery in both patients was uneventful and postoperative angiograms revealed widely patent grafts. This technique was very useful when performing off-pump CABG using bilateral ITAs.

Surgically treated aortic root aneurysm following aortic valve replacement

A 65-year-old man with aortic regurgitation underwent aortic valve replacement with a St. Jude Medical prosthetic valve about 6 years ago. At that time, the aortic root was slightly dilated at about 40 mm in diameter and the ascending aorta was within the normal range. This year, the man was diagnosed with an aortic root aneurysm in regular follow-up echocardiography. Chest-enhanced computed tomography and chest aortography at our hospital demonstrated a pear-like aortic root aneurysm about 60 mm in diameter. Elective operation for the aortic root aneurysm was conducted September 29, 1999, based on the Bentall procedure. Composite graft replacement with coronary reconstruction was conducted using a 28-mm Hemashield prosthetic graft and a 23-mm St. Jude Medical prosthetic valve under cardiopulmonary bypass. An 8-mm Hemashield graft was interposed on the left main coronary artery and the right coronary artery was directly anastomosed using a Carrel patch method. The postoperative course was uneventful and post-operative examination demonstrated good surgical results. Histological findings of the aortic aneurysm wall showed cystic medial necrosis. Surgical cases of aortic root aneurysm after aortic valve replacement are rare, but serious complications with the possibility of rupture or dissection warrant surgical intervention.

Polygodial, a potent attachment-inhibiting substance for the blue mussel, Mytilus edulis galloprovincialis from Tasmannia lanceolata

A highly potent attachment-inhibitor, polygodial, was isolated from a hexane extract of the leaves of Tasmannia lanceolata. The attachment-inhibiting activity of polygodial against the blue mussel was increased 4-fold when used in combination with sorbic acid, anethole, and indole.

Twenty-two-year follow-up of saphenous vein grafts in pediatric Kawasaki disease

We describe 2 Kawasaki disease patients with excellent long-term patency of saphenous vein grafts, who underwent coronary artery bypass at age 7 and 9 years, respectively, and demonstrated normal growth during 22 years of follow-up. The grafts showed no deterioration and played an important role in coronary blood supply.

Tricuspid valve replacement after cardiac transplantation

Tricuspid regurgitation, a fairly common finding after cardiac transplantation, is generally mild or moderate, and is not clinically significant. The etiology of tricuspid regurgitation is not entirely understood, and experience with valve replacement after cardiac transplantation is limited. We describe a case of progressively severe tricuspid regurgitation ultimately requiring tricuspid valve replacement. At operation, the ruptured chordae of the posterior part of anterior and septal leaflet with resulting partially flail leaflets were found. Examination of the papillary muscle showed origins of several of the ruptured chordae. Damage to the tricuspid subvalvular apparatus at endomyocardial biopsy appeared to be a possible cause. A 31-mm Carpentier-Edwards porcine valve was implanted. This was because replacement with a mechanical prosthesis would prevent future right-side heart catheterization and endomyocardial biopsy and in valve repair, the patient remains exposed to the risk of the recurrence of chordal rupture. We discuss proposed causes and choices in surgical technique.

Preparation of a Completely Oriented Molecular Sieve Membrane

Growth of oriented seed crystals on a substrate led to a completely oriented and continuous membrane of LTA-type zeolite. The seed crystals of cubic morphology were dip-coated onto a tilted substrate (see schematic diagram) with the zeolite channels normal to the surface. The substrate was hydrothermally treated in a reaction mixture containing the organic ligand 2,2-bis(hydroxymethyl)-2,2',2"-nitrilotriethanol, which lowers the degree of supersaturation of [Al(OH)(4)](-) ions and preferentially facilitates the intergrowth of the seed crystals.

Reactive oxygen species play an important role in the activation of heat shock factor 1 in ischemic-reperfused heart

BACKGROUND

The myocardial protective role of heat shock protein (HSP) has been demonstrated. Recently, we reported that ischemia/reperfusion induced a significant activation of heat shock factor (HSF) 1 and an accumulation of mRNA for HSP70 and HSP90. We examined the role of reactive oxygen species (ROSs) in the induction of stress response in the ischemic-reperfused heart.

METHODS AND RESULTS

Rat hearts were isolated and perfused with Krebs-Henseleit buffer by the Langendorff method. Whole-cell extracts were prepared for gel mobility shift assay using oligonucleotides containing the heat shock element. Induction of mRNA for HSP70 and HSP90 was examined by Northern blot analysis. Repetitive ischemia/reperfusion, which causes recurrent bursts of free radical generation, resulted in burst activation of HSF1, and this burst activation was significantly reduced with either allopurinol 1 mmol/L (an inhibitor of xanthine oxidase) or catalase 2x10(5) U/L (a scavenger of H2O2). Significant activation of HSF1 was observed on perfusion with buffer containing H2O2 150 micromol/L or xanthine 1 mmol/L plus xanthine oxidase 5 U/L. The accumulation of mRNA for HSP70 or HSP90 after repetitive ischemia/reperfusion was reduced with either allopurinol or catalase.

CONCLUSIONS

Our findings demonstrate that ROSs play an important role in the activation of HSF1 and the accumulation of mRNA for HSP70 and HSP90 in the ischemic-reperfused heart.

Identification and characterization of nuclear pore subcomplexes in mitotic extract of human somatic cells

In higher eukaryotic cells, it is generally thought that nuclear pore complex disassembles at the beginning of mitosis and reassembles at the end. Using a monoclonal antibody that recognizes nuclear pore antigens, we found that, at mitosis of mammalian somatic Hela cells, the nuclear pore complex disassembles into at least three subcomplexes, termed subcomplexes A, B and C (molecular mass; 2 MDa<, approximately 660 kDa, and approximately 440 kDa, respectively). The direct partial amino acid sequencing of the components of these subcomplexes indicates that the A subcomplex contains CAN/Nup214/p250 and p62 and the B subcomplex also contains p62, indicating that p62 is contained in two different subcomplexes. Subcomplex C was shown to consist of Nup98 and human RAE1, a human homolog of yeast Rae1p/Gle2p. Since Nup98 and Rae1p/Gle2p have been reported to be involved in mRNA export, this suggests that some of the mitotic subcomplex may be formed by functionally related proteins.

Evaluation of a compressive-type skeletal muscle pump for cardiac assistance

BACKGROUND

Recent investigations have focused on using the latissimus dorsi muscle for cardiac assistance. Although cardiomyoplasty has been applied clinically, other procedures remain experimental, but promising, modes of cardiac assistance. We assessed the latissimus dorsi muscle as an in situ energy source for circulatory assist devices.

METHODS

We developed a pneumatic chamber as a compressive-type muscle actuator. The chamber was implanted under the latissimus dorsi muscle and converted contractile power into pneumatic pressure. The effect of chamber position and size and the influence on muscle blood flow were examined. After muscle conditioning, the pump performance of a circulatory assist device driven by the chamber was evaluated.

RESULTS

The chamber functioned better when placed in the proximal position of the latissimus dorsi muscle. The size affected the generated pneumatic pressure, and the higher resting pressure of the chamber reduced the muscle blood flow. The maximum stroke work of the circulatory assist device was greater than that of the right ventricle but less than that of the left ventricle. The chamber could drive the circulatory assist device against the systemic range of afterload in which a high preload was available. Long-term adhesion surrounding the chamber reduced the pressure generation capability.

CONCLUSIONS

The compressive-type muscle actuator using the latissimus dorsi muscle generated acceptable hemodynamic work for right ventricular bypass or aortic counterpulsation.

Interaction of the Na+-K+ pump and Na+-Ca2+ exchange via [Na+]i in a restricted space of guinea-pig ventricular cells

1. The whole-cell Na+-K+ pump current (INa-K) and Na+-Ca2+ exchange current (INa-Ca) were recorded in guinea-pig ventricular myocytes to study the interaction between the two Na+ transport mechanisms. 2. INa-K was isolated as an external K+-induced current, and INa-Ca as an external Ca2+- induced or Ni2+-sensitive current. The experimental protocol used for one ion carrier did not affect the other. 3. The amplitude of INa-K decreased to 54 +/- 17 % of the initial peak during continuous application of K+ with 20 mM Na+ in the pipette. The outward INa-Ca, which was intermittently activated by brief applications of Ca2+, decreased during activation of INa-K, and recovered after cessation of INa-K activation. These findings revealed a dynamic interaction between INa-K and INa-Ca via a depletion of Na+ under the sarcolemma. 4. To estimate changes in Na+ concentration ([Na+]i) under the sarcolemma, the reversal potential (Vrev) of INa-Ca was measured. Unexpectedly, Vrev hardly changed during activation of INa-K. However, when INa-Ca was blocked by Ni2+ at the same time that INa-K was activated, Vrev changed markedly, maximally by +100 mV, immediately after the removal of Ni2+ and K+. 5. Subsarcolemmal [Na+]i was calculated from the Vrev of INa-Ca on the assumption that the subsarcolemmal Ca2+ concentration ([Ca2+]i) was fixed with EGTA, and mean [Na+]i was calculated from both the time integral of INa-K and the cell volume. The subsarcolemmal [Na+]i was about seven times greater than the mean [Na+]i. 6. The interaction between the Na+-K+ pump and Na+-Ca2+ exchange was well simulated by a diffusion model, in which Na+ diffusion was restricted to one-seventh (14 %) of the total cell volume.

Localization of the apoptosis-inducing activity of lupus anticoagulant in an annexin V-binding antibody subset

Lupus anticoagulant (LAC) is associated with arterial and venous thrombosis, thrombocytopenia, and recurrent fetal loss. We have reported previously that plasma with LAC activity induces apoptosis in endothelial cells and binds annexin V (Nakamura, N., Y. Shidara, N. Kawaguchi, C. Azuma, N. Mitsuda, S. Onishi, K. Yamaji, and Y. Wada. 1994. Biochem. Biophys. Res. Commun. 205:1488-1493). In this study, we separated two IgG antibody fractions, one with and one without affinity for annexin V, from 10 patients with LAC. LAC and apoptotic activities were localized in the annexin V-binding fraction in all 10 patients. DNA fragmentation was dose-dependent, paralleling the amount of IgG added to the human umbilical vein endothelial cell culture medium, and was inhibited by preincubation with annexin V. Removal of the antiphospholipid antibodies from patient IgG with phospholipid liposomes did not abolish the apoptosis-inducing activities or binding to annexin V. These results imply that patients with LAC often have antibodies that do not bind phospholipids and are responsible for the induction of apoptosis in endothelial cells.

Temporal lobe epilepsy in a genius of natural history: MRI volumetric study of postmortem brain

Kumagusu Minakata (1867-1941), a Japanese genius devoted to natural history and folklore, is famous for his immense range of works, including his discovery of many new varieties of mycetozoa, or slime molds. His diary reveals that he was affected by epilepsy. In this study of his brain, we adopted a method of measuring the volume of the hippocampi by MRI of postmortem brain and found evidence of right hippocampal atrophy. This finding, together with the striking parallels between his behavior and the known behavioral syndrome in temporal lobe epilepsy (TLE), suggests that he was affected by TLE. The postmortem imaging analysis of brain, as performed in this study, offers a bridge between neuroscience and classic psychopathologic approaches to the creativity of geniuses.

[Re-sternotomy]

The indications and techniques for an pitfalls to avoid which might result in complications after resternotomy are reviewed. The relationship between anterio mediastinal structures and the posterior aspect of the sternum (as visualized on chest, films, CT, or tomography), and other approach(es) including the pros and cons of the contemplated procedure must be assessed carefully. Preparations for emergency F-F cardiopulmonary bypass must be completed before resternotomy. The Wires of the previous operation are undone, but kept in place as safeguards during sternal division using an oscillating (not reciprocating) bone saw. After their removal, the pericardium or other mediastinal structures adhering to the posterior aspect of the sternum are freed before applying a small sternal retractor. The pericardial dissection plane is developed at the cardiophrenic angle, advanced cephalad and laterally on the surface of the right ventricle and atrium. Cephalad dissection starts with imnominate vein identification down the superior vent cave, keeping in mind the location of the right phyenic nerve, and toward the anterior aspect of the great vessels. Repairing small ventricular or aerial lacerations should not be attempted before releasing the tension by sharp dissection of the adhesions surrounding the laceration, and repair of great vessel injuries is best done under cardiopulmonary bypass.

[A successful case of minimally invasive direct coronary artery bypass (MIDCAB) followed by PTCA]

A 70-year-old man who developed angina pectoris underwent cardiac catheterization, which showed total occlusion of the left anterior descending coronary artery (LAD), associated with 75% stenosis of the right coronary artery (RCA) and 90% stenosis of the small circumflex coronary artery (CX). The LAD received good collateral flow from the RCA. The patient was scheduled to undergo the MIDCAB for the LAD using the internal thoracic artery (ITA), combined with percutaneous transluminal coronary angioplasty (PTCA) for the RCA subsequently. A left anterior submammarian skin incision of 10 cm in length was made. The fifth costal cartilage was removed. The left ITA was directly harvested from the chest wall from the 4th to 7th intercostal space, and was anastomosed to the midportion of the LAD without cardiopulmonary bypass. The patient was quickly recovered after the operation. On the 8th postoperative day, the patient successfully underwent the PTCA for the RCA after the ITA-LAD graft had been verified to be patent. The MIDCAB could be indicated for multivessel coronary disease in conjunction with the PTCA.

[A successful surgical repair of congenital mitral stenosis due to commissural papillary muscle fusion]

A case of congenital mitral stenosis, patent ductus arteriosus, pulmonary hypertension was reported. At one year of age, the patient underwent surgical division of PDA because of persistent left heart failure. She went well after the operation. At seven year of age, she was readmitted to our hospital for easy fatigability. The cardiac catheterization revealed remarkably elevated pulmonary arterial pressure and pulmonary capillary wedged pressure. She underwent a surgical intervention for the mitral stenosis at eight year of age. At operation, the mitral valve exhibited the characteristics of type IIc according to Carpentier's classification: thickened and dysplastic leaflet, extremely short chordae tendanae fused with papillary muscles, obliteration of interchordal space and hypertrophic two papillary muscles. We replaced the valve with 23 mm Carbomedicus prosthetic valve because it seemed to be difficult to repair the native valve satisfactorily without residual stenosis or insufficiency. Her postoperative course was uneventful and the pulmonary arterial pressure and pulmonary capillary wedged pressure decreased remarkably one year after the operation.

Surgical repair for supravalvular aortic stenosis: intermediate to long-term follow-up

BACKGROUND AND AIM OF THE STUDY

Supravalvular aortic stenosis (SAS) has been surgically treated by either single-sinus or bisinus patch repair. This article reviews intermediate to long-term results of repair in patients with SAS at our institute.

METHODS

Between 1974 and 1995, eight patients underwent surgical repair for SAS. The age range was 1.3 to 14 years (mean 7.3 years). The morphology was the discrete type in seven patients and the diffuse type in one patient. The pressure gradient across the obstruction was 20 to 105 mmHg (mean 68 mmHg). Two patients in the early period of the series underwent single-sinus patch repair, and six underwent bisinus patch repair (pantaloon-shaped patch, extended aortoplasty).

RESULTS

There were no operative deaths, and the mean pressure gradient was reduced to 23 mmHg (p < 0.001) in the early postoperative period. The median follow-up period was 8.0 years (1.8-17.3 years). One patient with diffuse type SAS required reoperation 12.8 years later due to progression of the stenosis, and died after the operation. The remaining seven patients were alive and well at the last follow-up, when the pressure gradient ranged from 6 to 31 mmHg (reoperation excluded).

CONCLUSION

Surgical repair for discrete type SAS provides satisfactory results in the intermediate to long-term follow-up.