The method of mouse embryoid body establishment affects structure and developmental gene expression.

To investigate formation of the three primary germ layers in mouse embryoid bodies (EBs), we observed changes in structure and gene expression over a 7-day culture period. We compared these changes using two methods for EB formation: hanging drop (HD) and static suspension culture (SSC). Light microscopy showed that a stratified columnar epithelial layer developed on the surface of EBs formed using the HD method. From Day 3 in culture, ultrastructural changes occurred in the aligned cellular membranes. Condensation of actin filaments was followed by formation of complicated adherent junctions and dilatation of intercellular canaliculi containing well-developed microvilli. These changes were more marked in EBs formed by the HD method than the SSC method. On Day 5 of culture, Brachyury gene expression, a marker for mesoderm formation, was detected only with the HD method. Nestin, an ectoderm marker, and Foxa2, an endoderm marker, were expressed with both methods. These results suggest that in EBs formed with the HD method, actin formation and Brachyury gene expression mark the transition from two to three primary germ layers. Additionally, the HD method promotes more rapid and complete development of mouse EBs than does the SSC method. While the SSC method is simple and easy to use, it needs improvement to form more complete EBs.

Restoration of wild-type p16 down-regulates vascular endothelial growth factor expression and inhibits angiogenesis in human gliomas.

Recent studies have indicated that the loss of p16 is a frequent event in the progression of malignant gliomas. The loss of p16 promotes the acquisition of malignant characteristics in gliomas, which are among the most angiogenic of all human tumors. High-grade gliomas are distinguished from low-grade gliomas by intense angiogenesis in addition to their frequent loss of p16. New therapeutic strategies aimed at inhibiting tumor angiogenesis on the basis of molecular mechanisms are theoretically attractive. Here we evaluate the effect of p16 gene replacement on the angiogenesis of gliomas. Infection with a recombinant replication-defective adenovirus vector containing the cDNA of wild-type p16 significantly reduced the expression of vascular endothelial growth factor, which is thought to be a pivotal mediator of tumor angiogenesis, in p16-deleted glioma cells. Restoring wild-type p16 expression into p16-deleted glioma cells markedly inhibited angiogenesis induced by tumor cells in vivo. Furthermore, wild-type p16 inhibited neovascularization more potently than did wild-type p53 transfer. These findings indicate that the p16 gene plays an important role in the regulation of glioma angiogenesis, suggesting a novel function of the p16 gene.

Experimental and theoretical studies of Si-Cl and Ge-Cl σ-bond activation reactions by iridium-hydride.

We report the iridium hydride-mediated Si-Cl and Ge-Cl σ-bond activation in a low-polarity toluene solution owing to diphosphine-chelation, in which the Si-Cl and Ge-Cl σ-bonds are readily cleaved through an SN2-type pathway via the formation of a free chloride anion.

Preoperative left ventricular function: minimal requirement for successful late results of valve replacement for aortic regurgitation.

Postoperative survival and left ventricular function were studied in 62 patients who underwent aortic valve replacement for isolated, chronic aortic regurgitation between 1978 and 1985. The average follow-up period was 3.8 years. There were three in-hospital and six late deaths. Five (56%) of the nine postoperative deaths were of cardiac-related causes. The mean 7 year survival rate was 83 +/- 5%. Preoperative left ventricular end-systolic volume index was the most important indicator (p less than 0.001) for subsequent cardiac death. The 6.5 year survival rate was 92 +/- 4% for patients with an end-systolic volume index less than 200 ml/m2 compared with 51 +/- 16% for those whose index was greater than 200 ml/m2. None of the 48 patients with an end-systolic volume index less than 200 ml/m2 died of cardiac-related causes. Twenty-three of the 48 patients with an end-systolic volume index less than 200 ml/m2 (Group 1) and 6 of the 12 patients with a higher index (Group 2) underwent repeat catheterization 26 months postoperatively. Preoperative afterload, assessed by end-systolic wall stress, was elevated in both groups, but decreased postoperatively, becoming identical to the afterload in 20 normal control subjects. Although the preoperative ejection fraction was depressed in both groups, the great majority of patients in Group 1, compared with none in Group 2, exhibited normal ejection fraction postoperatively. Thus, in patients who recently underwent surgery for aortic regurgitation, satisfactory late results in both long-term survival and reversal of left ventricular dysfunction were obtained when the preoperative end-systolic volume index was less than 200 ml/m2.

Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source.

The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd.

Free radical reaction and biological defense mechanism in the pathogenesis of prolonged vasospasm in experimental subarachnoid hemorrhage.

The relationship between free radical reactions and the defense mechanisms against them was investigated in the pathogenesis of prolonged vasospasm following experimental subarachnoid hemorrhage (SAH) in dogs. The concentration of lipid peroxides in the cerebro spinal fluid (CSF) increased markedly up to the eighth day following SAH; the concentrations also rose in the arterial wall (p less than 0.01) and the gray matter of the temporal lobe where the subarachnoid blood clots were (p less than 0.01). On the other hand, the activity of superoxide dismutase (SOD) decreased significantly up to the eighth day after SAH (p less than 0.01), and there was a gradual increase of glutathione peroxidase (GSH-px) in the CSF. In the arterial wall, there was a slight decrease in the activity of SOD, a significant decrease in the activity of GSH-px (p less than 0.01), and also a significant decrease in the concentration of glutathione (p less than 0.01) up to the eighth day following SAH. In conclusion, lipid peroxidation with insufficient biological defense mechanisms against it in the arterial wall, concomitant with that in the CSF, might take part in the genesis of prolonged vasospasm following SAH.

Improvement in local cerebral blood flow measurement in gerbil brains by prevention of postmortem diffusion of [14C]iodoantipyrine.

Postmortem diffusion of [14C]iodoantipyrine, which distorts the image of cerebral blood flow, can occur in at least three steps; from decapitation until the brain is frozen, while frozen sections on coverslips are thawed, and when dried sections are applied to x-ray film. In the present study, the first two steps were modified to reduce the time during which brain tissue was wet. When the brains of gerbils were taken out of the skulls and immersed in chilled isopentane (-45 degrees C), 90-95 s elapsed between decapitation until the brain tissues were frozen. However, immersion of whole heads in liquid nitrogen after decapitation decreased the time to 25 s. The autoradiograms had better contrast after the freezing procedure with liquid nitrogen than after that with chilled isopentane. The drying time of the thawed sections was markedly reduced by blowing hot air across the sections on a hot plate, and this resulted in clearer images on autoradiograms. In most of the tissues with values of cerebral blood flow over 100 ml 100 g-1 min-1 as measured using the conventional drying method, the corresponding values were higher if the modified method was used. In contrast, in tissues with values less than 100 ml 100 g-1 min-1, the corresponding values were lower. Moreover, the differences between flows in adjacent small brain structures were less clear if the sections were dried by the conventional method. Reducing the time during which postmortem brains or sections are wet can help prevent [14C]iodoantipyrine diffusion artifacts.

Outcome in acute stroke with successful intra-arterial thrombolysis and predictive value of initial single-photon emission-computed tomography.

This study investigates retrospectively, in selected patients, the ischemic outcome (reversible ischemia, infarction, and hemorrhage) and neurologic outcome of acute stroke treated with intra-arterial thrombolysis and the predictive value of pretreatment single-photon emission-computed tomography (SPECT). Thirty patients with complete recanalization within 12 hours were analyzed. The extent of ischemia was outlined on SPECT, and two CBF parameters were calculated: the ratio of ischemic regional activity to CBF in the cerebellum and the asymmetry index. Reversible ischemia, infarction, and hemorrhage were identified by comparing SPECT and follow-up computed tomography. Nine patients (30%) had no or small infarction, 14 (47%) had medium or large infarction, and seven (23%) had hemorrhage. Forty-two lesions were identified (22 reversible ischemia, 13 infarction, and 7 hemorrhage). Duration of ischemia, urokinase dose, disease type, and occlusion site were nonsignificant factors, whereas neurologic outcome and CBF parameters were significant among the three patient groups and three types of ischemic lesions. Ischemic tissue with CBF greater than 55% of cerebellar flow still may be salvageable, even with treatment initiated 6 hours after onset of symptoms. Ischemic tissue with CBF greater than 35% of cerebellar flow still may be salvageable with early treatment (less than 5 hours). Ischemic tissue with with CBF less than 35% of cerebellar flow may be at risk for hemorrhage within the critical time window. Pretreatment SPECT can provide useful parameters to increase the efficacy of thrombolysis by reducing hemorrhagic complications and improving neurologic outcome.

Role of protein kinase C in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage.

This study investigated the role of protein kinase C (PKC) in the pathogenesis of vasospasm after experimental subarachnoid hemorrhage (SAH). PKC activation by intracisternal injection of a phorbol ester [12-O-tetradecanoylphorbol-13-acetate (TP)] induced dose-dependent, slowly developing, severe contraction of the basilar artery. A single intracisternal injection of TP (5 x 10(-9) M in the CSF) induced sustained contraction lasting over 3 days, which almost paralleled the changes of membrane-bound PKC activity in the basilar arterial wall. In a two-hemorrhage SAH model, membrane-bound PKC activity in the basilar artery increased up to day 4 and returned to the control level by day 14, whereas angiographic contraction reached a maximum on day 7 and still persisted at a moderate level on day 14. Thus, there was a discrepancy between arterial PKC activity and arterial contraction. Multiple intracisternal injections of TP produced 30-40% sustained contraction of the basilar artery lasting for more than 10 days along with sustained activation of PKC to levels compatible with that observed in the SAH model. However, TP injection caused considerably milder histological changes in the basilar artery than those noted in the SAH model. We concluded that cerebral vasospasm after SAH cannot be explained solely on the basis of activation of the PKC pathway.

Changes in protein synthesis and calcium homeostasis in the thalamus of spontaneously hypertensive rats with focal cerebral ischemia.

The thalamus has been shown to undergo secondary degeneration after cerebrocortical ischemia. However, little is known about the time course of the retrograde thalamic degeneration. The present study was designed to investigate time-dependent changes in the morphology, protein synthesis and calcium metabolism of thalamic neurons in middle cerebral artery (MCA)-occluded spontaneously hypertensive stroke-prone rats that showed primary focal ischemia in the temporoparietal cortex after permanent occlusion of the left distal MCA. In the histologic study by light and electron microscopy, swelling of the nucleus and shrinkage of the perikarya were seen in some neurons of the ventroposterior (VP) thalamic nucleus on the lesioned side at 5 days after ischemia. At the same time, the incorporation of radiolabeled leucine in VP thalamic neurons began to decrease significantly with concomitant a decrease in the number of polyribosomes in the neurons. Conspicuous 45Ca accumulation was noted at 3 days after ischemia and persisted up to 1 month in the VP thalamic nucleus on the lesioned side. These findings suggest that the secondary thalamic degeneration after cortical infarction starts with disruption of calcium homeostasis in situ at the third day after MCA occlusion, followed by a decrease in polyribosomes but not by disaggregation of polyribosomes as seen in hippocampal CA1 neurons subjected to transient forebrain ischemia.

Impairment in biochemical level of arterial dilative capability of a cyclic nucleotides-dependent pathway by induced vasospasm in the canine basilar artery.

The authors investigated the changes and the potential of cyclic nucleotide-dependent signal transduction, which induces smooth muscle relaxation, in the basilar artery with severe vasospasm in dogs with double experimental subarachnoid hemorrhage (SAH) to explore at which biochemical level the arterial dilative capability was impaired. The amount of cyclic adenosine and guanosine monophosphates (cAMP and cGMP) decreased significantly in the basilar artery after SAH. The activities of adenylate and guanylate cyclases also were decreased significantly in the smooth muscle cells of the basilar artery 4 days after SAH. In addition to the failure of the pathways to produce cyclic nucleotides, the activities of cAMP- and cGMP-dependent protein kinases, which are representative actual enzymes that amplify the signal for vascular dilation, also significantly decreased together with the almost total loss of activation by cyclic nucleotides in the same basilar artery after SAH. It was revealed that the system for smooth muscle relaxation was impaired severely in the cerebral arteries with severe vasospasm after SAH, on the biochemical basis of significantly less vasodilative capability and in several of the steps to produce the cyclic nucleotides of intracellular signal transduction.

Calcium movement in ischemia-tolerant hippocampal CA1 neurons after transient forebrain ischemia in gerbils.

Hippocampal CA1 neurons exposed to a nonlethal period (2 min) of ischemia, acquired tolerance to a subsequent lethal 5-min period of ischemia, which usually causes delayed-type neuronal death. Intracellular Ca2+ movements before and after the 5 min of forebrain ischemia were evaluated in gerbil hippocampal CA1 pyramidal neurons, had acquired tolerance in comparison with nonischemia-tolerant CA1 neurons. Evaluation was performed by observing the ultrastructural intracellular Ca2+ distribution and the Ca2+ adenosine triphosphatase (Ca(2+)-ATPase) activity using electron microscopic cytochemistry. In comparison with nonischemia-tolerant CA1 neurons, mitochondria of ischemia-tolerant CA1 neurons sequestered more Ca2+ from the cytosomal fraction 15 min after the 5-min period of ischemia, and Ca2+ deposits in these mitochondria were rapidly decreased. Plasma membrane Ca(2+)-ATPase activities were already significantly elevated before the 5 min of ischemia, and remained at a higher level subsequently compared to nonischemia-tolerant CA1 neurons. Changes in the mitochondrial Ca2+ distribution and Ca(2+)-ATPase activities in ischemia-tolerant CA1 neurons after the 5-min period of ischemia showed a strong resemblance to those in CA3 neurons, which originally possess resistance to such periods of ischemia. These findings suggest that enhanced or maintained activities of mitochondrial Ca2+ sequenstration and plasma membrane Ca(2+)-ATPase reduced Ca2+ toxicity following 5-min ischemia in terms of time, resulting in escape from delayed neuronal death.

Protein synthesis and immunoreactivities of contraction-related proteins in smooth muscle cells of canine basilar artery after experimental subarachnoid hemorrhage.

We examined time-dependent changes in protein synthesis and in the immunoreactivities of representative contraction-related structural proteins in smooth muscle cells of canine basilar arteries after experimental subarachnoid hemorrhage (SAH). Protein synthesis was assessed by the percentage of polyribosome-forming ribosomes to total ribosomes (aggregation rate), a morphological index of the activity of protein synthesis. The aggregation rates in prostaglandin F2 alpha-(PGF 2 alpha) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced contracted basilar arteries were 70.0 +/- 7.0% and 71.4 +/- 8.7%, respectively, quite similar to the value in normal basilar artery (73.0 +/- 8.0%). In the single-SAH group with little delayed histological changes in the basilar arteries, the aggregation rate was significantly decreased to 30.5 +/- 6.4% by 24 h after the SAH, and recovered to 52.3 +/- 9.0% and 70.2 +/- 7.6% at 7 and 14 days postSAH, respectively, when the vasospasm was moderately and completely ameliorated. In contrast, in the double-SAH group in which the basilar arteries developed delayed smooth muscle cell death and long-lasting arterial contraction, a significant decrease in the aggregation rate (25.0 +/- 5.0% on day 4) persisted for 14 days. The in vitro incorporation of [3H]-leucine in the basilar arterial cells was also significantly suppressed 4 and 7 days after the initial SAH (1.2 +/- 0.4 and 1.4 +/- 0.3 x 10(3) dpm/mg protein) in the double-SAH group, as opposed to no significant decrease in the basilar artery at 7 days postSAH in the single-SAH group (1.9 +/- 0.6 x 10(3) dpm/mg protein). The immunoreactivity of alpha-smooth muscle actin, a contractile protein, demonstrated by immunohistochemistry and immunoblots, was not altered for up to 14 days even in the double-SAH group, but that of calponin and of h-caldesmon, contraction-inhibiting proteins, was markedly reduced 4-14 days after the initial SAH. Persistent impairment of protein synthesis and relative reduction of immunoreactivities of the contraction-inhibiting proteins were observed in arteries with severe vasospasm and loss of smooth muscle cells, as noted in the double-SAH subjects. These abnormalities may cooperate to cause cerebral arterial narrowing accompanied by degeneration of smooth muscle cells after SAH.

An 18-mer peptide fragment of prosaposin ameliorates place navigation disability, cortical infarction, and retrograde thalamic degeneration in rats with focal cerebral ischemia.

It was previously reported that prosaposin possesses neurotrophic activity that is ascribed to an 18-mer peptide comprising the hydrophilic sequence of the rat saposin C domain. To evaluate the effect of the 18-mer peptide on ischemic neuronal damage, the peptide was infused in the left lateral ventricle immediately after occlusion of the left middle cerebral artery (MCA) in stroke-prone spontaneously hypertensive (SP-SH) rats. The treatment ameliorated the ischemia-induced space navigation disability and cortical infarction and prevented secondary thalamic degeneration in a dose-dependent manner. In culture experiments, treatment with the 18-mer peptide attenuated free radical-induced neuronal injury at low concentrations (0.002 to 2 pg/mL), and the peptide at higher concentrations (0.2 to 20 ng/mL) protected neurons against hypoxic insult. Furthermore, a saposin C fragment comprising the 18-mer peptide bound to synaptosomal fractions of the cerebral cortex, and this binding decreased at the 1st day after MCA occlusion and recovered to the preischemic level at the 7th day after ischemia. These findings suggest that the 18-mer peptide ameliorates neuronal damage in vivo and in vitro through binding to the functional receptor, although the cDNA encoding prosaposin receptor has not been determined yet.

Differential vulnerability in the hindbrain neurons and local cerebral blood flow during bilateral vertebral occlusion in gerbils.

Differential vulnerability in the hindbrain neurons was examined immunohistochemically during hindbrain ischemia in the gerbil. Hindbrain ischemia was produced by extracranial occlusion of the bilateral vertebral arteries just before their entry into the transverse foramen of the cervical vertebra. Local cerebral blood flow was measured by quantitative autoradiographic technique after 5 min of ischemia and was reduced to less than 5 ml/100 g per min in the cerebellum, the pons, and the medulla, indicating that severe and reproducible hindbrain ischemia was induced immediately after occlusion. For immunohistochemical investigation, four gerbils each were used for each ischemic period of 5, 10, 15, and 30 min. Immunohistochemical lesions, detected by the reaction for microtubule-associated protein 2, were visible in the lateral vestibular nucleus and the cerebellar interpositus nucleus even after 5 min of ischemia. These results suggested that these areas were more vulnerable than others, although blood flow was markedly reduced in various regions of the hindbrain. In contrast, areas related to respiratory or cardiovascular control were rather resistant to ischemia. The present study suggests that selective vulnerability during hindbrain ischemia depends mainly on different metabolic characteristics inherent to various neurons in the hindbrain.

Brainstem auditory evoked potentials during brainstem ischemia and reperfusion in gerbils.

To evaluate the reversibility of neural function in the brainstem following ischemia, we investigated the effect of transient brainstem ischemia on the brainstem auditory evoked potential in gerbils. Brainstem ischemia was produced by bilateral extracranial occlusion of vertebral arteries. Local cerebral blood flow was measured by quantitative autoradiography after 5 min of ischemia and was reduced to less than 3 ml/100 g per min in the pons and lower midbrain, indicating severe and reproducible brainstem ischemia. During brainstem ischemia, brainstem auditory evoked potential waveforms disappeared completely. After a brief ischemic insult (5 min), all four brainstem auditory evoked potential components recovered to normal. After longer ischemic insults (10-30 min), brainstem auditory evoked potential components never recovered to normal. Microtubule-associated protein 2 immunoreactivity revealed differential vulnerability of the acoustic relay nuclei in the brainstem. Neurons in the lateral lemniscus were most vulnerable, followed in order by neurons in the trapezoid body, the superior olive and the cochlear nucleus. We also demonstrated a close relationship between the reversibility of ischemia-induced changes on brainstem auditory evoked potential and ischemic lesions of these relay nuclei. These data may be useful for evaluating the therapeutic window of thrombolytic therapy during acute vertebrobasilar occlusion.

Kinetic behavior of technetium-99m-HMPAO in the human brain and quantification of cerebral blood flow using dynamic SPECT.

The kinetic behavior of 99mTc-hexamethylpropyleneamine oxime (HMPAO) in the human brain was investigated in 11 patients with various brain diseases (176 regions), using dynamic SPECT and a four-compartment model with five parameters (K1: rate constant for the transport of HMPAO from blood to brain, K2: backdiffusion from brain to blood, K3: conversion to a hydrophilic form in the brain, K5: conversion to a nondiffusible form in the blood, and fa: fraction of radioactivity attributable to the vascular compartment). Although K1 correlated well with cerebral blood flow (CBF) measured by the 133Xe inhalation method (Xe-CBF) (r = 0.888), its value was underestimated by 28.9% +/- 11.9%, indicating a low extraction fraction (E) for HMPAO. From E = K1/CBF, a regression equation of E = 0.857 - 0.00335. Xe-CBF was obtained. Significant correlations were observed for K2 versus Xe-CBF (r = 0.679), for K3 versus Xe-CBF (r = 0.483), for K3/(K2 + K3) versus Xe-CBF (r = -0.487), for K3/K2 versus Xe-CBF (r = -0.501), and for K2 + K3 versus Xe-CBF (r = 0.655), but not for K1/K2 versus Xe-CBF (r = 0.005). Thus, this model was useful for elucidating the kinetic behavior of HMPAO in the human brain, and correction for E appears to be indispensable for accurate CBF quantification using HMPAO.

Evaluation of regional myocardial perfusion in areas of old myocardial infarction after revascularization by means of intraoperative myocardial contrast echocardiography.

Because myocardial revascularization to areas of old myocardial infarction brings about functional recovery to some extent to myocytes in those areas, the assessment of regional myocardial perfusion on those areas after myocardial revascularization may allow myocardial viability to be estimated. Using intraoperative myocardial contrast echocardiography by direct injection of 2 ml sonicated 5% human albumin into saphenous vein grafts, we assessed regional myocardial perfusion in 16 revascularized areas of old myocardial infarction. We estimated the myocardial viability of areas with respect to myocardial perfusion, and we compared these results to both the improvement of regional wall motion after myocardial revascularization (increase in segmental wall thickening during systole) and relative thallium 201 activity obtained by quantitative analysis of preoperative exercise myocardial thallium 201 distribution on delayed images. The background-subtracted peak peak intensity of myocardial enhancement and the ratio of endocardial to epicardial intensity were determined in each revascularized area. An inverse correlation existed between peak intensity (18 +/- 7) and the endocardial/epicardial ratio (0.88 +/- 0.17) (r = -0.63, p < 0.01). A good correlation was found between peak intensity and both the percent increase in segmental wall thickening (r = 0.73, p < 0.005) and the relative thallium 201 activity (r = 0.81, p < 0.005). These results suggested that regional myocardial perfusion after myocardial revascularization in areas of old myocardial infarction distributed better to the epicardial halves than to the endocardial halves, and that the peak intensity could be related to myocardial viability.

Reconsiderations of indications for open mitral commissurotomy based on pathologic features of the stenosed mitral valve. A fourteen-year follow-up study in 347 consecutive patients.

From January 1972 to December 1984, 347 consecutive patients underwent open mitral commissurotomy for mitral stenosis. Commissurotomy was performed in 86% of 404 patients undergoing mitral valve operations for stenosis during the same period. These 347 patients had three different types of mitral stenosis: type I, mobile cusps without subvalvular changes (43 patients); type II, thickened cusps with subvalvular changes (210 patients); type III, rigid cusps with severe subvalvular changes (94 patients). Concomitant mild mitral regurgitation was seen in 87 patients (25.1%) and mild to moderate valve calcification in 61 patients (17.6%). There were eight early deaths (2.3%) and 12 late deaths (3.5%), yielding an actuarial survival rate of 94.6% (excluding early deaths) 14 years after operation. There were 17 reoperations (5.0%) The actuarial rates of freedom from reoperation were as follows: 83.8% at 14 years for the entire series; 73.5% for type I stenosis; 88.9% for type II; 84.0% for type III; 91.7% for mitral stenosis with calcification; 82.6% for stenosis without calcification; 90.6% for pure mitral stenosis; and 52.5% for stenosis combined with regurgitation (p less than 0.05). Postoperative effective mitral valve areas calculated according to the hydraulic formula were 2.52 cm2 (mean) at rest and 3.06 cm2 during exercise in six patients with type I stenosis, 2.21 and 2.48 cm2, respectively, in 10 with type II, and 1.85 and 1.87 cm2, respectively, in 14 with type III. Our data clearly demonstrated that open mitral commissurotomy provided excellent long-term results with acceptable valve function and a low incidence of reoperation in patients with pure mitral stenosis not combined with regurgitation, even when associated with severe subvalvular changes with or without mild to moderate valve calcification.

Evaluation of long-term results of bicuspidalization annuloplasty for functional tricuspid regurgitation. A seventeen-year experience with 133 consecutive patients.

Between 1968 and 1985, 133 consecutive patients underwent bicuspidalization annuloplasty for moderate to severe functional tricuspid regurgitation associated with mitral or combined mitral and aortic valve disease. Over this period, the incidence of tricuspid valve replacement was only 2.3% (3/136 patients). There were 18 early deaths (13.5%) in the entire series--three (5.0%) of 60 patients in the last 5 years of the study--and 10 late deaths (8.7%). Actuarial survival rate for the entire series, excluding early deaths, was 91.0% +/- 3.0% at 10 and 17 years. There were seven reoperations (6.1%) on the tricuspid valve, needed because of residual or recurrent mitral valve lesions after the initial operation. Actuarial rates of freedom from reoperation on the tricuspid valve were 93.6% +/- 3.0% (10 years) and 69.7% +/- 16% (17 years) for the entire series: 78% +/- 10% (15 years) for the open mitral commissurotomy plus tricuspid annuloplasty group (44 patients); 90% +/- 9.0% (15 years) for the mitral plus tricuspid annuloplasty group (10); 75.2% +/- 22% (17 years) for the mitral replacement plus tricuspid annuloplasty group (58); and 92.6% +/- 7.0% (16 years) for the combined aortic and mitral valve surgery plus tricuspid annuloplasty group (21). Ninety-eight percent of the survivors were in New York Heart Association class I or II postoperatively. Of 21 randomly selected patients investigated by pulsed Doppler echocardiography, 14 (67%) had no regurgitation or grade 1/4 tricuspid regurgitation and the remaining seven (33%) had grade 2/4 regurgitation postoperatively. Our experiences suggest that bicuspidalization annuloplasty can be a reliable method in the vast majority of patients with functional tricuspid regurgitation.