Magnetic stimulation and movement-related cortical activity for acute stroke with hemiparesis.

BACKGROUND AND PURPOSE: This double-blind, randomized, placebo-controlled study investigated the beneficial effects of repetitive transcranial magnetic stimulation (rTMS) to patients with motor paresis in acute subcortical stroke on functional recovery and electrophysiological measures. METHODS: Twenty patients with acute stroke were randomized into real rTMS (n = 10) or sham (n = 10) groups. Patients received five daily sessions of rTMS with 1200 pulses at 1 Hz for 20 min or sham stimulation over the contralesional motor cortex. Movement-related cortical potential MRCP, consisting of the Bereitschaftpotential, negative slope (NS') and motor potential (MP), was recorded during self-paced wrist extension of the affected limb associated with assessment of the Fugl-Meyer assessment (FMA) of the upper extremity, the pegboard test and the grip strength before and after the rTMS session. RESULTS: Real rTMS improved the FMA and pegboard test scores compared to the sham group in the affected hand. This improvement was associated with increases in the MP and NS' over the front-central sites in the ipsilesional hemisphere, whereas the sham group did not show significant changes in MRCP components by rTMS. CONCLUSIONS: Our findings suggest that low-frequency rTMS to the contralesional motor cortex facilitates functional recovery of paretic limbs in acute stroke patients through enhancing the the neuronal activity of ipsilesional motor and pre-motor areas.

Seroprevalence survey on measles, mumps, rubella and varicella antibodies in healthcare workers in Japan: sex, age, occupational-related differences and vaccine efficacy.

A seroprevalence survey on measles, mumps, rubella and varicella was conducted on healthcare workers (HCWs) at Shimane University Hospital, Japan utilizing an enzyme immunoassay. Of 1811 HCWs tested, 91.8% were seropositive to measles, 92.1% to mumps, 89.5% to rubella and 96.3% to varicella. Sex-related differences in seroprevalence were found in rubella (males vs. females: 84.7 vs. 92.2%, P < 0.001). Moreover, males aged 30-39 years were most susceptible to rubella (22.4%), which may be attributed to the design of childhood immunization programmes in Japan. Individuals aged ≤ 29 years were more susceptible to measles (14.3%) and mumps (10.9%), compared to other age groups. There were no significant sex- and age-related differences in varicella seroprevalence. The physician occupational group was more susceptible to rubella, but no significant occupational-related difference was observed in the other diseases. Susceptible subjects, with negative or equivocal serological results were given a vaccine which induced seroconversion in most vaccinees. Seroconversion occurred more frequently in the equivocal group than in the negative group. These findings provide a new insight for the seroprevalence survey of vaccine-preventable diseases in Japanese HCWs with special reference to vaccine efficacy.

Immunocytochemical evidence for translocation of protein kinase C in human megakaryoblastic leukemic cells: synergistic effects of Ca2+ and activators of protein kinase C on the plasma membrane association.

Immunological analysis using monoclonal antibodies against subspecies of protein kinase C revealed the predominant expression of the isozyme, type II, in human megakaryoblastic leukemic cells. We investigated the effects of phorbol diester 12-O-tetradecanoyl phorbol-13-acetate (TPA), the Ca2+ ionophore ionomycin and synthetic diacylglycerol 1-oleoyl-2-acetylglycerol (OAG) on the immunocytochemical localization of protein kinase C in these cells. Indirect immunofluorescence techniques revealed the enzyme to be located in a diffuse cytosolic pattern, in the intact cells. When the cells were exposed to 100 nM TPA, the immunofluorescent staining was translocated from the cytoplasm to the plasma membrane. The translocation was protracted and staining on the membrane decreased in parallel with the Ca2+, phospholipid-dependent protein kinase activity. Treatment of the cells with 500 nM ionomycin caused an apparent translocation comparable with that seen with TPA, however, this translocation was transient and most of the cytosolic staining was within 60 min. We also found that 30 micrograms/ml OAG did not have significant effects on distribution of the staining, but rather acted synergistically on the translocation with the suboptimal concentration of 100 nM ionomycin. A similar synergism was also observed with 10 nM TPA and 100 nM ionomycin. These results obtained in situ provide evidence that intracellular Ca2+ and diacylglycerol regulate membrane binding of the enzyme in vivo.

Differential diagnosis of the infundibular dilation and aneurysm of internal carotid artery: assessment with fusion imaging of 3D MR cisternography/angiography.

Fusion imaging of 3D MR cisternography/angiography was used for the assessment of the vascular bulging finding detected by MR angiography from the viewpoint of the outer wall configuration of the corresponding internal carotid artery depicted by MR cisternography. With a fusion image, useful information was obtained to distinguish an infundibular dilation and enlarged origin of the normal posterior communicating artery from an aneurysm. This imaging technique can be a feasible addition to a noninvasive screening of cerebrovascular lesions with MR angiography alone.

Endovascular treatment for elderly patients with ruptured aneurysm.

We report our results of endovascular treatment for elderly patients with ruptured aneurysm and discuss the indication for treatment. One hundred and thirty four consecutive patients with ruptured aneurysm treated in our institute during the last 4 years were retrospectively evaluated. Fifty eight patients were included in group A (over 70 years old), and 76 patients in group B (under 69 years old). In both groups, the outcome was strongly related to the preoperative Hunt & Kosnik grade. However, significant risk factors (i.e. pneumonia, rupture of extracranial aneurysm) which make prognosis poor were more common in group A. Group A showed poor outcome in grade III patients, although there were no outcome differences between the two groups in patients of other grades. Endovascular treatment for elderly patients with ruptured aneurysms seemed to be useful. Their outcome was strongly related to their preoperative condition. General risk factors should be evaluated before treatment, especially in elderly patients. Patients with low Hunt & Kosnik grade seem to be most suitable for endovascular treatment. On the other hand, outcome of patients with poor preoperative grade was worse despite the less invasive nature of endovascular treatment. An improvement of outcome in grade III patients is desirable.

Decoy administration of NF-kappaB into the subarachnoid space for cerebral angiopathy.

Subarachnoid hemorrhage (SAH), encephalitis, meningitis, and autoimmune diseases sometimes lead to cerebral angiopathy, characterized specifically by narrowing of vessels, morphological changes in the structure of vessel walls, and a concomitant decrease in cerebral blood flow. Many patients also develop delayed ischemic neurological deficits. Thus, preventing vascular reactions is of paramount importance in treating SAH. Although cerebral vasospasm has some relationship with the inflammatory reaction of major cerebral vessels against the autologous blood, and many trials have attempted to prevent angiopathy after SAH, an effective treatment has not yet been established. The purpose of this article is to evaluate the preventive effect of nuclear factor KB (NF-kappaB) decoy oligo-DNA after SAH; since NF-kappaB is closely related to inflammation. In the rabbit angiopathy model after SAH, we evaluated the effectiveness of the decoy oligo-DNA using the angiographic (digital subtraction angiography) and histological (hematoxylin-eosin and Masson's trichrome staining) methods. Moreover, a gel-shift assay for NF-kappaB was also performed in order to evaluate the activity of NF-kappaB. We describe a new concept for treating cerebral angiopathy after SAH and for successfully inhibiting cerebral vasospasm and morphological changes in vessel walls in a rabbit model. In this treatment, we used synthetic double-strand oligo-DNA with a high affinity for transcription factor NF-kappaB, and cationic liposome complex administered through the cerebrospinal fluid.

Different expression of protein kinase C isozymes in pancreatic islet cells.

To elucidate differential roles of protein kinase C isozymes in pancreatic islet cells, the precise localization of the isozymes in rabbit and rat islet endocrine cells was investigated using monoclonal antibodies specific for three types of the enzyme. We detected strong immunoreactivity for the type III protein kinase C in B cells. Immunoreactivity for the type II enzyme was seen in A cells, and no apparent immunoreactivity for type I was observed in the islet cells. The expression of the type III protein kinase C in B cells was confirmed using rat insulinoma cells. The predominant expression of the type III enzyme in these cells was shown by immunoblotting. Moreover, on the basis of an enzyme-linked sandwich immunoassay, the levels of protein kinase C isozymes were determined in these cells. The significant amounts of the type III enzyme was detected, but the contents of the type I and II enzyme were under detectable level. These results suggest that the type III protein kinase C is involved in the regulation of insulin release in pancreatic B cells.

The enhancement of myocardial protection through an acalcemic storage solution containing nicardipine, a potent calcium channel blocker. A basic study using rat ventricular myocytes.

Adult rat ventricular myocytes were used as a model system for investigating the direct effects of nicardipine, a potent calcium-channel blocker, on preservation of the heart during periods of simple cold storage. Cells were stored at 4 degrees C for 24 hr with an acalcemic storage solution. The superfusate then was exchanged with hypoxic Tyrode solution (1.8 mmol/L CaCl2). After 2 hr of hypoxia at 20 degrees C, cells were reoxygenated and simultaneously warmed to 37 degrees C. The addition of nicardipine to both the storage solution and Tyrode solution resulted in the highest percentage of viable cells (70.5%). Using either the storage solution or Tyrode solution containing the compound, the percentages of viable myocytes were 51.9% and 52.2%, respectively. In the absence of the drug in either solution, the percentage was 38.0%. The effect of diltiazem, another potent calcium-channel blocker, was examined using the same experimental procedure. The addition of diltiazem to Tyrode solution elevated the viability of ventricular myocytes, but addition to the storage solution showed no cardioprotective effect. Moreover, the addition of 8-bromo cyclic GMP to the storage solution resulted in a cardioprotective effect. These results suggested that nicardipine exerts a direct effect on myocardial protection in hypothermic and acalcemic storage solution and that the pharmacological effect of nicardipine depends on a mechanism other than its calcium-channel blocking action.

A heparin-coated circuit maintains platelet aggregability in response to shear stress in an in vitro model of cardiopulmonary bypass.

Alterations in platelet aggregability may play a role in the pathogenesis of qualitative platelet defects associated with cardiopulmonary bypass (CPB). We circulated fresh heparinized whole blood through tubing sets coated with heparin (C group, n = 10) and through non-coated sets (N group, n = 10) as a simulated CPB circuit. Shear stress (108 dyne/cm2)-induced platelet aggregation (hSIPA), plasma von Willebrand factor (vWF) activity and platelet glycoprotein (GP) Ib expression were measured, before, during, and after this in vitro set up of circulation. In the two groups, the extent of hSIPA significantly decreased during circulation and was partially restored after circulation. Decreases in the extent of hSIPA were significantly less with use of heparin-coated circuits. There was an equivalent reduction in plasma vWF activity, in the two groups. Expression of platelet surface GP Ib decreased significantly during circulation and recovered after circulation. Reduction of surface GP Ib expression during circulation was significantly less in the C group than that in the N group. Decrease in surface GP Ib expression correlated (r = 0.88 in either group) with the magnitude of hSIPA, in the two groups. The progressive removal of surface GP Ib was mainly attributed to redistribution of GP Ib from the membrane skeleton into the cytoskeleton. Our observations suggest that use of heparin-coated circuits partly blocks the reduction of hSIPA, as a result of a lesser degree of redistribution of GP Ib.

An FTIR study on the structure of the oxygen-evolving Mn-cluster of Photosystem II in different spin forms of the S(2) state.

The S(2) state of the oxygen-evolving Mn-cluster of Photosystem II (PS II) is known to have different forms that exhibit the g =2 multiline and g = 4.1 EPR signals. These two spin forms are interconvertible at > 200 K and the relative amplitudes of the two signals are dependent on the species of cryoprotectant and alcohol contained in the medium. Also, it was recently found that the mutiline form can be converted to the g = 4.1 form by absorption of near-infrared light by the Mn-cluster itself at around 150 K [Boussac et al. (1996) Biochemistry 35: 6984-6989]. We have used light-induced Fourier transform infrared (FTIR) difference spectroscopy to study the structural difference in these two S(2) forms. FTIR difference spectra for S(2)/S(1) as well as for S(2)Q(A) (-)/S(1)Q(A) measured at cryogenic temperatures using PS II membranes in the presence of various cryoprotectants, and monohydric alcohols did not show any specific differences except for intensities of amide I bands, which were larger when ethylene glycol or glycerol was present in addition to sucrose. This result was interpreted due to more flexible movement of the protein backbones upon S(2) formation with a higher cryoprotectant content. Light-induced difference spectra measured at 150 K using either blue light without near-infrared light or red plus near-infrared light also did not show any detectable difference. In addition, a different spectrum upon near-infrared illumination at 150 K of the PS II sample in which the S(2) state had been photogenerated at 200 K exhibited no meaningful signals. These results indicate that the two S(2) forms that give rise to the multiline and g = 4.1 signals have only minor differences, if any, in the structures of amino-acid ligands and polypeptide backbones. This conclusion suggests that conversion between the two spin states is caused by a spin-state transition in the Mn(III) ion rather than valence swapping within the Mn-cluster that would considerably affect the vibrations of ligands.

Ultrafiltration of the priming blood before cardiopulmonary bypass attenuates inflammatory response and improves postoperative clinical course in pediatric patients.

The priming solution using in cardiopulmonary bypass (CPB) for infants undergoing cardiac surgery includes considerable amounts of stored blood. Our objective was to test the hypothesis that ultrafiltration (UF) of the stored blood before CPB reduces the unfavorable effects of stored blood and the production of inflammatory cytokines. Fifty pediatric patients with congenital heart defects took part in this study. The patients were randomly divided into two groups: the UF (27 pediatric patients who received UF) and control (23 pediatric patients who did not receive UF) groups. UF was performed with a polysulphone ultrafiltrator before CPB. Blood samples were collected immediately before, during, and 1 h after CPB. The levels of cytokines (TNF-alpha, IL-1beta, IL-8), NH3, and bradykinin were determined. The serum concentrations of NH3 and bradykinin decreased significantly after UF. Compared with the control group, the UF group had significantly lower cytokine production. Water balance in UF group was better than that of control group. The UF group received significantly less inotropic support and shorter duration of ventilator support and ICU stay. We conclude that removal of bradykinin and a decrease in the levels of NH3, potassium, and pH play a significant role in reducing water retention and postoperative lung injury. UF of the blood used to prime the circuit for CPB is a safe and efficient method for use in open heart surgery in small pediatric patients.

Erythropoietin in pediatric cardiac surgery: clinical efficacy and effective dose.

We assessed the clinical efficacy and determined the effective dose of erythropoietin (EPO) in 48 children scheduled for open heart surgery without blood transfusion. The children were divided into three groups: group 1 (n=21) was treated with 300 U/kg of EPO; group 2 (n=11) was treated with 150 U/kg of EPO; and group 3 (n=16) was not treated with EPO. EPO was administered on the day of hospital admission (6 to 7 days prior to surgery), on the following day, immediately after surgery, and on the following day. Immediately after surgery, the hemoglobin concentration in groups 1 and 2 was significantly higher than that in group 3. The reticulocyte count in groups 1 and 2 was significantly higher than that in group 3. Open heart surgery was completed without transfusion in all 21 patients in group 1 (100%), 10 of 11 in group 2 (90.9%), and 11 of 16 in group 3 (68.8%). EPO caused no adverse reactions. In conclusion, EPO was effective as an adjuvant therapy for open heart surgery without blood transfusion in children. Administration of a relatively high dose of EPO (300 U/kg) seems to be effective for pediatric patients.

Effects of inhaled nitric oxide in single lung transplantation in rats with monocrotaline-induced pulmonary hypertension.

BACKGROUND: The edema of grafted lungs during the early postoperative period is one of the serious complications of single lung transplantation for primary pulmonary hypertension. METHODS: The effectiveness of inhaled nitric oxide in single lung transplantation for primary pulmonary hypertension during the early postoperative period was evaluated with the use of rats with monocrotaline-induced pulmonary hypertension. In the inhaled nitric oxide group, rats were given 60 parts par million of nitric oxide for 24 hours just after left lung transplantation; in the no inhaled nitric oxide group, rats were kept without nitric oxide inhalation; in the control group, normal rats received left isografts. RESULTS: Three hours after transplantation, the mean pulmonary artery pressure of the no inhaled nitric oxide group (28.0 +/- 4.6) was significantly higher than that of the control group (23.3 +/- 0.9, p < 0.05) and the inhaled nitric oxide group (22.7 +/- 1.7, p < 0.05). On the first postoperative day, the mean left-to-right pulmonary blood flow ratio in the inhaled nitric oxide group was 0.34 +/- 0.03; it showed no significant difference to those of the other two groups, whereas that of the no inhaled nitric oxide group (0.42 +/- 0.14) was significantly elevated compared with that of the control group (0.14 +/- 0.03, p < 0.05). Histopathologically, the edema of the grafted lungs 24 hours after operation in the inhaled nitric oxide group was less severe than that in the no inhaled nitric oxide group. CONCLUSIONS: The postoperative use of inhaled nitric oxide is effective to reduce the pulmonary edema of the grafts in single lung transplantation for pulmonary hypertension by reducing acute pulmonary blood flow shift toward grafts after transplantation.

Significance of bronchial mucosal blood flow for the monitoring of acute rejection in lung transplantation.

Bronchial mucosal blood flow (BMBF) was measured with a laser-Doppler flowmeter in a canine model (n = 20), and the measurement was evaluated to see if it was a useful method for diagnosing allografted lung rejection. The ratio of the value of BMBF at the level of the donor second carina against that at the level of carina (the L/C ratio, an index of BMBF of donor bronchus) decreased in accordance with the extent of lung rejection, and it increased and entered the normal range with the reversal of lung rejection. Compared with the L/C ratio and the rejection grade by histologic changes in open-lung biopsy, the L/C ratio at grade 0 (latent phase) was 0.91 +/- 0.07; at grade Ia (early vascular phase), 0.86 +/- 0.05; at grade Ib (late vascular phase), 0.68 +/- 0.10; at grade II (early alveolar phase), 0.60 +/- 0.14; and at grade III (late alveolar phase), 0.50 +/- 0.15. A significant difference was noted between grades Ia and Ib (p less than 0.01) and between grades Ib and III (p less than 0.01). The sensitivity and the specificity in the detection of early rejection before grade Ib were 96% and 92%, with only one false-negative and two false-positives resulting from 51 measurements of BMBF. In three cases of serious lung infections, the L/C ratio did not fall, and the rejection could be distinguished from infection. These results suggest that measurement of the BMBF is useful for detecting the early rejection of transplanted lungs.

Anti-gizzard MLCK monoclonal antibody MM13 inhibits superprecipitation and phosphorylation of bovine aortic smooth muscle actomyosin.

We prepared monoclonal antibodies directed against chicken gizzard myosin light chain kinase (MLCK) and used them to study the contractile system of aortic smooth muscle. One monoclonal antibody, MM13, dose dependently inhibited actomyosin superprecipitation of bovine aortic smooth muscle, in accord with the suppression of 20 kDa myosin light chain phosphorylation by endogenous kinase. Immunoblotting analysis demonstrated that MM13 cross-reacted with the 150,000 Mr peptide of bovine aortic actomyosin preparation. The bovine aortic MLCK was purified approximately 2,400-fold to apparent homogeneity by three steps of column chromatography. The purified enzyme has a molecular weight of 150,000 and a slower mobility than chicken gizzard MLCK (130,000 Mr), as determined by SDS-polyacrylamide gel electrophoresis. MM13 also cross-reacted with purified bovine aortic MLCK and inhibited the kinase activity, in vitro. We interpret these findings to mean that binding of the anti-gizzard MLCK monoclonal antibody directly to aortic smooth muscle MLCK (150,000 Mr) decreases the phosphorylation of the 20 kDa myosin light chain, thus suppressing the aortic smooth muscle myosin-actin interaction.

Monoclonal antibody assessment of tissue- and species-specific myosin light chain kinase isozymes.

Monoclonal antibodies raised against chicken gizzard smooth muscle myosin light chain kinase were used for immunological and structural studies of this enzyme. Epitope mapping of trypsin-digested chicken gizzard enzyme showed that MM-1, 2, 3, 4, 5, 6, and 7 bind to 65 kDa (trypsin-digested) and 60 kDa (chymotrypsin-digested) fragments which contain the catalytic domain of the kinase. Kinetic analysis demonstrated that MM-7 inhibited kinase activity competitively with respect to ATP and noncompetitively with respect to myosin light chain, thereby indicating that MM-7 binds at or near the ATP binding site of the enzyme. Immunoblot analysis revealed that all these antibodies (MM-1 to 12) reacted with the enzyme (130 kDa) from intestinal and vascular smooth muscles, whereas 5 (MM-1, 3, 4, 6, and 9) or 3 (MM-1, 3, and 4) of 12 antibodies did not cross-react with chicken cardiac muscle or with blood platelet myosin light chain kinase (130 kDa), respectively. None of these antibodies showed cross-reactivity against skeletal muscle myosin light chain kinase. As for mammalian species, MM-11 and 12 reacted with myosin light chain kinase of vascular smooth muscle (140 kDa) and MM-11 cross-reacted with the enzyme (140 kDa) from cardiac muscle of rat and rabbit. These data suggest the existence of at least 4 subspecies of myosin light chain kinase in chicken tissues and the heterogeneity of tissue- and species-specific isozyme forms.

Surgical repair of extracardiac unruptured acquired Valsalva aneurysms.

Two cases of extracardiac unruptured Valsalva aneurysms due to rare causes are reported. One patient had been suffering from hyper eosinophilic syndrome. Operative corrections consisted of total replacement of the aortic root. The other patient had an aneurysm of just noncoronary sinus of Valsalva and a dilated ascending aorta due to cystic mucoid degeneration. Replacement of the ascending aorta with patch closure for the aneurysm was successfully performed.

Fulminant myasthenia gravis manifested after removal of anterior mediastinal tumor.

Myasthenia gravis developed in a 35-year-old man after removal of an encapsulated anterior mediastinal tumor that was preoperatively diagnosed as a teratoma based on a computed tomographic image. Postoperative pathologic diagnosis of the excised tumor was thymoma. The patient was in crisis after the initiation of immunosuppressive treatment. The therapy was changed to immunoadsorbent perfusion therapy because of concurrent severe pneumonia and an extremely high serum concentration of anti-acetylcholine receptor antibodies. Respiratory support was necessary for 2 months after reoperation.

Long-term follow-up after Carpentier-Edwards ring annuloplasty for tricuspid regurgitation.

BACKGROUND: Use of flexible rings for tricuspid ring annuloplasty is becoming popular. This study was undertaken to evaluate Carpentier-Edwards (C-E) rigid ring annuloplasty for tricuspid regurgitation (TR), secondary to mitral valve disease and clinical outcome on a long-term basis. METHODS: From December 1985 to March 1996, 45 patients with secondary TR underwent C-E ring annuloplasty. Thirty-nine patients (95.1%) were in New York Heart Association (NYHA) functional class III or IV. The mean follow-up was 96.7+/-48.5 months or 362.6 patient-years. RESULTS: There were three in-hospital and nine late deaths that were not related to tricuspid annuloplasty. Actuarial survival at 10 years was 68.3%. Echocardiographic studies showed that TR was well controlled within grade 2+ in all survivors. Residual pulmonary hypertension (PH) was recognized in 9 of 21 patients (42.9%) with preoperative PH, however, no TR was seen in 6 patients. A TR grade of 2+ was observed in 3 patients. Thirty of the total survivors (96.8%) were in NYHA class I and II, but 1 patient was in NYHA class III. The actuarial rate of freedom from tricuspid valve reoperation after 10 years was 97.5%. CONCLUSIONS: C-E ring annuloplasty is acceptable for repair of secondary TR and improvement in clinical status on a long-term basis.

Terminal warm blood cardioplegia improves cardiac function through microtubule repolymerization.

BACKGROUND: To elucidate the mechanisms responsible for the beneficial effects of terminal warm blood cardioplegia, we studied dynamic change in microtubules induced by cold cardioplegia followed by rewarming. Further, we investigated the relationship between cardiac function and morphologic changes in microtubules caused by hyperkalemic, hypocalcemic warm cardioplegia during initial reperfusion. METHODS: In protocol 1 isolated rat hearts were perfused at 37 degrees C with Krebs-Henseleit buffer (KHB). After 3 hours of hypothermic cardiac arrest at 10 degrees C, hearts were reperfused at 37 degrees C with one of two buffers: group C, 60-minute reperfusion with KHB (K+, 5.9 mmol/L; Ca2+, 2.5 mmol/L); and group TC, 10-minute initial reperfusion with modified KHB (K+, 15 mmol/L; Ca2+, 0.25 mmol/L), followed by 50 minutes of reperfusion with KHB. Cardiac function after reperfusion was determined as a percentage of the prearrest value. In protocol 2 hearts were perfused at 37 degrees C with KHB containing colchicine (10(-5) mol/L) for 60 minutes. RESULTS: There was spontaneous contractile recovery after 10 minutes of initial reperfusion in hearts from group TC as well as improved cardiac function after 15, 30, and 60 minutes of reperfusion compared with that in group C. Immunohistochemical staining and immunoblot analysis demonstrated microtubule depolymerization during hypothermic cardiac arrest and complete repolymerization after 10 minutes of reperfusion with warm buffers in both groups. Colchicine-induced microtubule depolymerization is associated with deterioration of cardiac function. CONCLUSIONS: One mechanism responsible for improved cardiac function mediated by terminal warm blood cardioplegia is the restart of contraction after complete microtubule repolymerization.