[Relapse after video-assisted thoracoscopic surgery for spontaneous pneumothorax]

Postoperative relapse was noted in 8 (14.8%) of 54 patients who underwent video-assisted thoracoscopic surgery for spontaneous pneumothorax followed for more than one year. Five of the eight patients with relapse were among the 15 initial-stage cases. Concerning treatment, only drainage was performed in 1 patient, and thoracotomy was performed in 5 patients. Findings on additional surgery consisted of missed cystic lesions, in 2 patients, a small opening adjacent to a suture caused by an autosuture device in 1 patient, and a cyst around a suture in patients. There was no missed cystic lesion after the 15th case. In subsequent cases, there were changes at the periphery of a suture. In patients with other diseases, there were no changes observed when an autosuture device was used under thoracoscopic guidance. Therefore, the changes may be associated with hypertonus of the emphysematous lung at the periphery of the site where an autosuture device was used. Thoracoscopic surgery for spontaneous pneumothorax using an autosuture device has limitations such as the presence of a dead angle, insufficient evaluation of emphysematous changes in the collapse lung, a large volume of resected tissue, and hypertonus of the peripheral lung. These limitations may contribute to a high recurrence rate of spontaneous pneumothorax. To reduce the recurrence rate, conditions and problems in cases showing relapse should be clarified before selecting treatment including pleurodesis in individual cases.

Bni1p and Bnr1p: downstream targets of the Rho family small G-proteins which interact with profilin and regulate actin cytoskeleton in Saccharomyces cerevisiae

The RHO1 gene encodes a homologue of mammalian RhoA small G-protein in the yeast Saccharomyces cerevisiae. Rho1p is required for bud formation and is localized at a bud tip or a cytokinesis site. We have recently shown that Bni1p is a potential target of Rho1p. Bni1p shares the FH1 and FH2 domains with proteins involved in cytokinesis or establishment of cell polarity. In S. cerevisiae, there is an open reading frame (YIL159W) which encodes another protein having the FH1 and FH2 domains and we have named this gene BNR1 (BNI1 Related). Bnr1p interacts with another Rho family member, Rho4p, but not with Rho1p. Disruption of BNI1 or BNR1 does not show any deleterious effect on cell growth, but the bni1 bnr1 mutant shows a severe temperature-sensitive growth phenotype. Cells of the bni1 bnr1 mutant arrested at the restrictive temperature are deficient in bud emergence, exhibit a random distribution of cortical actin patches and often become multinucleate. These phenotypes are similar to those of the mutant of PFY1, which encodes profilin, an actin-binding protein. Moreover, yeast two-hybrid and biochemical studies demonstrate that Bni1p and Bnr1p interact directly with profilin at the FH1 domains. These results indicate that Bni1p and Bnr1p are potential targets of the Rho family members, interact with profilin and regulate the reorganization of actin cytoskeleton.

Double-outlet right ventricle with intact ventricular septum

An infant with double-outlet right ventricle (DORV) with intact ventricular septum (VS) is described. Hypoplastic left ventricle and mitral valve atresia were also associated. To the authors' knowledge, this appears to be the first case in which this rare form has been demonstrated with magnetic resonance imaging (MRI). The patient required balloon atrial septostomy (BAS) three times until 4 months of age because of progressive cyanosis. In such a form of DORV, surgical atrial septectomy should be performed instead of repeating BAS because the tendency to functional closure of the restrictive secundum arterial septal defect caused by incompetent foramen ovale seems to be prominent.

Analysis of the tumor staining obtained by preoperative IV-DSA for breast cancer patients: density and metastasis correlation

We examined the density of tumor enhancement on intravenous digital subtraction angiography (IV-DSA) in patients with breast cancer in relation to disease-free survival. The subjects of the present study consisted of 103 patients with invasive ductal carcinoma measuring 5 cm or less treated from July 1988 to September 1993. In the 103 patients, 15 had distant metastasis. The region of interest was set in the areas enhanced by IV-DSA of the breast. The maximum density (MAX) was calculated by the time-density curve. When the patients were divided according to three classes of MAX, i.e., 0-5.0 pixels (group A, n = 23), 5.1-9.0 pixels (group B, n = 50), 9.1 pixels or more (group C, n = 30), disease-free survival was highest in group A followed by group B and C, respectively. The disease-free survival rate in group C was significantly lower than that of group A or B (p < 0.05). Thus, high values of MAX were associated with low rates of disease-free survival. Since the value of MAX was found to be independent from other prognostic factors by multivariate analysis, these results indicate that MAX has a close correlation with metastasis or recurrence of breast cancer, making IV-DSA a promising prognostic factor.

Effects of extended cold preservation and transplantation on the rat liver microcirculation

Liver sinusoidal endothelial cell impairment and/or microcirculatory disturbances are thought to induce storage-related graft failure; however, the respective roles of changes induced by extended cold preservation and transplantation, as well as their interactions, are still unknown. To this end, the alterations of the liver microcirculation and of hepatocyte and sinusoidal endothelial cell functions induced by extended cold preservation and/or transplantation were assessed using an isolated perfused rat liver model combined to an orthotopic rat liver transplantation model. Liver microcirculation remained minimally altered following extended cold ischemia alone, despite a marked deterioration of sinusoidal endothelial cell function, while liver microcirculation alterations were mainly characterized by areas of no-reflow following transplantation alone. It was only when both procedures were associated that hepatocyte function became markedly compromised, without further deterioration in liver microcirculation. It is concluded that extended cold preservation and transplantation as such are not associated with lethal liver injury. However, the sinusoidal cell impairment and the liver microcirculatory disturbances, induced by both conditions combined, are important factors leading to secondary hepatic nonfunction, which might be triggered by extrahepatic events.

Serial recording of somatosensory and myoelectric motor evoked potentials: role in assessing functional recovery after graded spinal cord injury in the rat

Accurate functional outcome measures are essential in assessing therapeutic interventions after experimental spinal cord injury (SCI). We examined the hypothesis that serial recording of somatosensory (SSEP) and myoelectric motor evoked potentials (mMEPs) would provide complementary information to standard methods of behavioral analysis in a rat model of SCI and would allow objective discrimination of functional recovery in sensory and motor tracts. Clip compression injury of varying severity (sham, 23 g, 34 g, 56 g) and transections were performed at T1 in adult rats. SSEPs were recorded from the right sensorimotor cortex (SMC) after stimulation of the contralateral hind paw; mMEPs were recorded from the paraspinal, quadriceps, and the tibialis anterior muscles after anodal stimulation of the SMC. The inclined plane and Tarlov techniques were used to assess clinical neurological function. All outcome measures were assessed weekly prior to and up to 6 weeks following injury. Changes in clinical neurological function as assessed by the inclined plane and Tarlov methods varied with increasing injury severity (R = -0.72 and R = -0.73, respectively). SSEP latency was strongly correlated with injury severity (R = 0.92) and with clinical behavioral scores (R = -0.93 for inclined plane). The tibialis anterior mMEP correlated significantly, though weakly, with changes in inclined plane (R = 0.49) and Tarlov scores (R = 0.41). Although the mMEPs were sensitive to the presence of SCI, these recordings did not discriminate between severities of injury. We conclude that serial recording of SSEPs but not myoelectric MEPs correlates closely with the extent and temporal course of clinical neurological recovery after graded SCI in the rat.

[Effects of ischemic preconditioning on the recovery of myocardial function after unprotected ischemia and cardioplegia in the isolated and crystalloid perfused rat hearts]

Preconditioning with repetitive brief periods of ischemic (IPC) is known to induce myocardial protection against a subsequent more prolonged period of ischemia. We investigated whether IPC can offer similar beneficial effects on myocardial function after cardioplegic preservation in isolated and crystalloid-perfused rat hearts. IPC was produced by 5 periods of 1 min ischemia followed by 5 min reperfusion before 25 min of unmodified ischemia or 40 min of cardioplegia. IPC had no significant effect on the time to contractile arrest (control: 211 +/- 27 sec, IPC: 240 +/- 32 sec) after unmodified ischemia, while the time to electrical asystole was significantly (p < 0.05) shortened by IPC (676 +/- 107 sec) compared to control (1021 +/- 197 sec). However, rapid contractile arrest concomitant with electrical asystole was induced by infusion of St. Thomas' Hospital solution in control as well as in IPC-treated hearts without a significant intergroup difference (control: 33 +/- 7 sec, IPC 39 +/- 9 sec). Although myocardial ATP was significantly reduced by IPC, IPC-treated hearts showed a significantly higher ATP level after 25 min of unprotected ischemia. Accumulation of myocardial lactate after 25 min of unprotected ischemia was significantly (p < 0.05) inhibited by IPC. However, the levels of myocardial ATP and lactate after 40 min of cardioplegia were comparable between control and IPC-treated hearts. Left ventricular developed pressure (LVDP) at 30 min reperfusion after unprotected ischemia was significantly improved by IPC, while the recovery of LVDP at 30 min reperfusion after cardioplegia was comparable between control and IPC-treated hearts. The onset of ischemic contracture, i.e., a rise of left ventricular end-diastolic pressure (LVEDP), was significantly accelerated and its magnitude was significantly greater in IPC-treated hearts during unprotected ischemia and also during cardioplegia. However, a significant decrease of LVEDP during reperfusion compared to control hearts was observed only after unprotected ischemia. The amounts of creatine kinase (CK) released during 30 min reperfusion after unprotected ischemia was significantly greater in control than in IPC-treated hearts, but there was no significant difference in CK release between control and IPC-treated hearts during reperfusion after cardioplegia. These results suggest that IPC-induced cardioprotection may be induced via inhibition of anaerobic energy metabolism through a negative chronotropic effect during unprotected ischemia, but such a beneficial effect is dissipated with cardioplegia by which rapid electrical asystole is induced. It is, therefore, concluded that IPC may not provide additional myocardial protection over conventional hyperkalemic cardioplegia.

Heterogeneity of DNA content in multiple synchronous hepatocellular carcinomas

Heterogeneity of DNA content in multiple hepatocellular carcinomas (HCCs) was investigated by flow cytometry in 62 tumours from 26 patients who had undergone surgical treatment for multiple synchronous HCCs. Heterogeneity of DNA content was defined (a) when tumours had a different DNA ploidy pattern or (b) when the difference in the DNA index of the aneuploid clone was more than 0.1. A tumour with DNA aneuploidy was observed in 17 (66%) of the 26 patients. Heterogeneity of the DNA content was demonstrated in 12 (46%) out of 26 patients: in ten cases by definition (a) and in two cases by definition (b). Histological examination revealed that, of the 12 patients with a heterogeneous tumour DNA content, seven (58%) had a heterogeneous and the remaining five (42%) had a homogeneous type and grade of differentiation among the tumours, showing the absence of a relationship between histological heterogeneity and DNA content. The present results suggest the clinical relevance of DNA content analysis for identifying the clonal origin of multiple HCCs.

Influence of residual antegrade coronary blood flow on the long-term prognosis of medically treated patients with myocardial infarction and single-vessel disease

We assessed the influence of residual antegrade coronary perfusion on long-term mortality and morbidity in 262 patients (256 men and 6 women, aged 52.3 +/- 9.8 years) with medically treated old myocardial infarction and single-vessel disease who were followed for 117.0 +/- 39.8 months. Partial or complete antegrade coronary perfusion of the infarct artery was present in 165 patients (group I); no or minimal antegrade perfusion of the infarct artery was present in 97 patients (group II). There was no significant difference in survival between group I (5-year survival rate, 96.9% and 10-year survival rate, 90.7%) and group II (93.8% and 92.7%, respectively). There was also no significant difference in the event free survival rate between group I (5-year, 92.6% and 10-year, 79.7%) and group II (89.5% and 74.8%, respectively). The extent of left ventricular dysfunction was an important determinant of prognosis: 10-year survival rates in patients with ejection fractions of > 60%, 40-60% and < 40% were 94.8%, 90.6% and 74.8%, respectively. In the majority of patients the subsequent cardiac events were related to the progression of atherosclerosis in previously nonstenotic coronary arteries. Thus the presence or absence of residual antegrade coronary flow in the chronic phase of myocardial infarction did not significantly influence the long-term prognosis of patients with single-vessel disease.

[Bronchogenic carcinoma located in the aortic window]

In the patients with invasion to the aortic window, we performed operation via median sternotomy combined with anteroaxillar thoracotomy. In such patients with T4 invasion, conventional pneumonectomy could not be performed because of the extensive invasion near the main pulmonary artery trunk. In these patients in this study, complete resection of the involved pulmonary artery could be performed using a vascular clamp without CP bypass. Operative technique was as follows: first, the pericardium was opened and taping of the aorta was applied. When the uninvolved part of the intrapericardial pulmonary artery was long enough to cut, we could use a stapling device, but the stapling device could not be used in many cases because the length of the uninvolved segment was too short to cut the left pulmonary artery. In order to carry out complete resection, it was necessary to clamp the central part of the main pulmonary artery diagonally from the left lower side to the right upper side. The pulmonary arterial stump was closed with continuous 4-0 monofilament mattress and over and over suture. We recommend an aggressive surgical approach for the tumor with invasion to the aortic window, because the prognosis is dismal in nonresected locally advanced lung cancer.

Interleukin 1 beta and stromelysin (MMP3) activity of synovial fluid as possible markers of osteoarthritis in the temporomandibular joint

PURPOSE

This study investigated the early signs of synovitis and cartilage degradation by means of synovial fluid analysis in temporomandibular joints (TMJs) with internal derangement (closed lock) or osteoarthritis (OA).

PATIENTS AND METHODS

Synovial fluid was obtained from 25 TMJs in 22 patients diagnosed with closed lock and from 15 asymptomatic TMJs of 12 normal controls. IL-1 beta concentrations were measured using enzyme-linked immunosorbent assay (ELISA), and proteinase activity was detected by means of gelatin enzymography.

RESULTS

Nine of the 25 TMJs with closed lock (CL group) exhibited osteolytic changes on the surface of the condyle. TMJs in the normal control group did not show any bony changes. Mean IL-1 beta concentration in the synovial fluid (SF) protein in the CL group was 330.1 +/- 347.7 pg per 100 micrograms protein, which was significantly higher than in the normal control (76.7 +/- 95.3 pg/100 micrograms SF-protein). Synovial fluid from the TMJs with osteolytic changes contained higher levels of IL-1 beta (531.8 +/- 379.6 pg/100 micrograms SF-protein) than those without bony changes (216.7 +/- 280.1 pg/100 micrograms SF-protein). Matrix metalloproteinase (MMP) activity with a molecular weight of 50 kd (stromelysin or MMP3) was detected in a highly augmented form in two synovial fluid samples of seven closed lock patients.

CONCLUSION

The results suggest that IL-1 beta levels in synovial fluid of the TMJ have a positive correlation with OA change. The MMP3 activity detected was greatly increased in patients with cartilage degradation. These findings suggest that both changes may be important markers of early bone deterioration in TMJs that are undetectable by radiograph imaging.

Heart rate, blood lactate responses and ratings of perceived exertion to 1,000 punches and 1,000 kicks in collegiate karate practitioners

The purpose of this study was: 1) to investigate the responses of heart rate (HR), blood lactate and ratings of perceived exertion (RPE) to 1,000 punches and 1,000 kicks in collegiate highly skilled (BB Group) and novice (WB Group) karate practitioners; and, 2) to compare RPE obtained from the subjects to RPE expected by their coaches. The mean values of HR, percent of maximal HR (% HRmax), percent of maximal HR reserve (% MHRR), blood lactate and RPE in 1,000 punches for the BB Group were 102.5 +/- 14.8 beats. min-1, 53.1 +/- 8.5%, 27.1 +/- 12.7%, 0.8 +/- 0.2 mmol.1-1 and 12.2 +/- 1.2 respectively, and for the WB Group were 116.1 +/- 17.9 beats. min-1, 58.1 +/- 7.7%, 35.2 +/- 13.3%, 1.2 +/- 0.6 mmol.1-1 and 12.8 +/- 1.2, respectively. Likewise, the mean values in 1,000 kicks for the BB Group were 127.4 +/- 12.4 beats. min-1, 66.0 +/- 8.0%, 47.0 +/- 12.5%, 1.3 +/- 0.4 mmol.1-1 and 14.2 +/- 1.2, respectively, and for the WB Group were 137.0 +/- 14.4 beats.min-1, 70.1 +/- 7.4%, 52.0 +/- 12.8%, 2.4 +/- 0.8 mmol. 1-1 and 16.3 +/- 1.5, respectively. These responses to 1,000 punches and 1,000 kicks were moderate, and the RPE for 1,000 punches in both BB and WB Groups and for 1,000 kicks in the BB Group were significantly lower than the RPE expected by their coaches.

Heart rate response and perceived exertion during twenty consecutive karate sparring matches

This study investigated the changes in heart rate (HR) and perceived exertion ratings (RPE) of 20 consecutive karate sparring matches each of 2 minutes duration. The resting and maximal HR (HRmax) responses to the maximal treadmill test were 69.8 +/- 2.9 beats.min-1 and 198.5 +/- 8.2 beats.min-1, respectively. The resting HR before the 20 sparring matches was 83.5 +/- 11.3 beats min-1. The mean HR during the 20 sparring matches was 191.8 +/- 9.4 beats.min-1 which was equal to 96.7 +/- 4.2% of HRmax. At the end of the 20 sparring matches, the mean RPE obtained was 19 +/- 2. The results of this study suggest that the subjects could continue the 20 sparring matches for about 40 minutes at the intensity close to the HRmax.

Bni1p implicated in cytoskeletal control is a putative target of Rho1p small GTP binding protein in Saccharomyces cerevisiae

The RHO1 gene encodes a homolog of mammalian RhoA small GTP binding protein in the yeast Saccharomyces cerevisiae. Rho1p is localized at the growth sites, including the bud tip and the cytokinesis site, and is required for bud formation. We have recently shown that Pkc1p, a yeast homolog of mammalian protein kinase C, and glucan synthase are targets of Rho1p. Using the two-hybrid screening system, we cloned a gene encoding a protein which interacted with the GTP-bound form of Rho1p. This gene was identified as BNI1, known to be implicated in cytokinesis or establishment of cell polarity in S.cerevisiae. Bni1p shares homologous domains (FH1 and FH2 domains) with proteins involved in cytokinesis or establishment of cell polarity, including formin of mouse, capu and dia of Drosophila and FigA of Aspergillus. A temperature-sensitive mutation in which the RHO1 gene was replaced by the mammalian RhoA gene showed a synthetically lethal interaction with the bni1 mutation and the RhoA bni1 mutant accumulated cells with a deficiency in cytokinesis. Furthermore, this synthetic lethality was caused by the incapability of RhoA to activate Pkc1p, but not glucan synthase. These results suggest that Rho1p regulates cytoskeletal reorganization at least through Bni1p and Pkc1p.

Radiofrequency catheter ablation of supraventricular tachycardias in patients with hypertrophic cardiomyopathy

Supraventricular tachycardias, as well as ventricular tachycardia, are critical patients with hypertrophic cardiomyopathy. Anti-arrhythmic agents often induce arrhythmias, known as pro arrhythmia. Radiofrequency catheter ablation has become a well-established therapy for the treatment of supraventricular tachycardia. The reported success rate is over 90%, although catheter mapping in the left ventricle is difficult in patients with hypertrophic cardiomyopathy because of the marked left ventricular wall thickening associated with bizarre myocardial hypertrophy with disorganization, the abundant capillary muscle networks, and annoying ventricular arrhythmias. This report documents catheter mapping technique of radio frequency ablation in patients with hypertrophic cardiomyopathy and supraventricular tachycardias.

Eosinophilia in premature infants: correlation with chronic lung disease

We attempted to clarify the possible pathophysiological significance of eosinophilia in bronchopulmonary dysplasia (BPD). The subjects studied were 17 premature infants, i.e. seven with respiratory distress syndrome (RDS) followed by bronchopulmonary dysplasia (the BPD group: four with stage IV and three with stage III BPD) and 10 infants without BPD (the non-BPD group), who comprised seven with RDS, two with meconium aspiration syndrome and one with transient tachypnea of the newborn. Peripheral eosinophil counts, the number of nuclei of eosinophils and serum eosinophilic cationic protein (ECP) levels, and ECP and polymorphonuclear leukocyte (PMN) elastase levels of intratracheal aspirates (TA) were determined once a week during the first 4 weeks of life. Peripheral eosinophil counts were higher in infants with BPD than those in the non-BPD group. Hypersegmented nuclei of peripheral eosinophils with more than four nuclei were more frequently present in the infants with BPD. A good correlation was observed between peripheral eosinophil counts and serum ECP levels. ECP levels of the TA in the infants with BPD were significantly elevated. There was a good correlation between ECP and PMN elastase levels of the TA. Lung tissue specimens of two infants of the BPD group, both of whom had patent ductus arteriosus (PDA), were obtained from the lower portion of the left lung when they underwent an operative procedure for PDA at 24 and 25 days of life, respectively. Immunohistochemical staining of eosinophil-derived granular major basic protein (MBP) was performed on the lung tissue specimens. Infiltration of a few MBP-staining eosinophils was observed on the specimens from both infants. Our results suggest that peripheral eosinophils in sick premature infants may be activated and appear to be correlated with the severity of BPD. Further studies will be needed to more clarify the physiological role of eosinophils in premature infants.

Atrioventricular junctional rhythm induced by sympathetic stimulation in E-4031-treated dog hearts

To investigate the role of delayed rectifier potassium current (IK) on the sympathetic control of the heart, we studied the effects of E-4031, a blocker of the rapidly activating type of IK (IKr), on the chronotropic, dromotropic, and inotropic responses to sympathetic nerve stimulation in the autonomically decentralized hearts of open-chest anesthetized dogs, E-4031 (0.01-3 mumol/kg intravenously, i.v.) decreased the heart rate (HR) dose dependently without affecting other cardiac functions. After E-4031 treatment, cardiac sympathetic nerve stimulation changed the sinus rhythm to the atrioventricular (AV) junctional rhythm in 6 of 11 anesthetized dogs (55%). In three of six junctional rhythm hearts, sinus rhythm supervened during sympathetic stimulation for 2 min. The number of pacemaker shifts to junctional rhythm increased as the dose of E-4031 was increased. However, E-4031 attenuated neither the positive chronotropic, dromotropic, nor right atrial and ventricular inotropic responses to sympathetic nerve stimulation. These results suggest that IKr inhibition may induce the AV junctional rhythm due to the combination of the different participation of IKr, the different resting potentials, and the different sensitivity to sympathetic activation among cardiac pacemaker cells.

Direct transaortic balloon valvuloplasty under cardiopulmonary bypass for neonatal critical aortic stenosis

A 1-day-old male infant with critical aortic valvular stenosis underwent balloon aortic valvuloplasty (BAV) under echocardiographic guidance during cardiopulmonary bypass. Left ventricular function dramatically improved after BAV. This technique combined with a surgical approach was safe and efficient.

[MRSA-induced prosthetic valve endocarditis complicated by synthetic graft infection that did not respond to repeated vancomycin administration but improved after surgery]

We performed AVR and OMC in a 55-year-old male with ASR complicated by MS and ASO. Postoperatively, an ulcer formed on the left lower extremity, resulting in methicillin-resistant Staphylococcus aureus (MRSA) infection. Axillo-bilateral-femoral artery bypass was performed using synthetic grafts. However, infection developed in the anastomosis site, leading to MRSA sepsis. Since MRSA is highly susceptible to vancomycin (VCM), this drug was administered at a dose of 1.5 g/day. With negative conversion of MRSA, the infected wound healed, and the general status improved. However, after discontinuation of VCM administration, sepsis recurred. VCM administration was resumed with prolongation of the administration period and an increase in the dose. Drug administration was discontinued 3 times after 2-4 weeks each, but recurrence was observed each time. During this period, AR due to prosthetic valve endocarditis (PVE) developed. AVR and MVR were performed again, and the synthetic graft was left in place. However, after discontinuation of postoperative VCM administration, infection of the synthetic graft was also demonstrated. The graft was removed, and revascularization was performed by another route. The patient improved after these procedures. When MRSA-induced PVE or synthetic graft infection develops, the infectious foreign material should be completely removed at an early stage before progression of tissue destruction or ulcer formation even if antibiotics are effective.

Mechanism of stereoselective serum binding of ketoprofen after hemodialysis

In vitro studies of serum protein binding were conducted to examine the influence of hemodialysis therapy on the stereoselectivity for ketoprofen (KP) in patients with renal dysfunction. In normal volunteers, only small differences in binding to undiluted serum were observed between the enantiomers of racemic KP (10 micrograms/mL). As compared with healthy volunteers, significantly impaired binding to undiluted serum was observed in uremic patients before they received dialysis. This reduced binding was not accompanied by alterations in stereoselectivity. At the end of dialysis, a similar extent of defective binding to undiluted serum was still observed, whereas interestingly, its stereoselectivity was significantly enhanced. These findings indicated that preferential inhibition for S-enantiomer serum binding was caused by changes that occurred during hemodialysis. Among various physiological parameters, only enantioselective inhibition of KP serum binding was correlated with heparin-induced increases in free fatty acids (FFA) levels and with unbound levels of uremic toxins with indole ring, indoxyl sulfate and indole acetate. To elucidate the effects of these accumulated endogenous substances in serum of patients, ultrafiltration was also used to study the binding of KP enantiomers to isolated human serum albumin under various conditions. After dialysis, mean albumin level and pH value in patients were slightly but significantly altered, but in vitro binding data indicated that these factors could clearly be ruled out as an explanation for the origin of the induced stereoselectivity. In contrast to palmitate, oleate and laurate markedly induced the stereoselective inhibition, which indicated that these fatty acids preferentially inhibited the binding of S-KP via a competitive and allosteric mechanism. Among the four uremic toxins, only indoxyl sulfate and indole acetate predominantly displaced the S-enantiomer rather than its antipode through competitive interaction. In addition, serum unbound levels of indole uremic toxins were correlated with elevated FFA levels. FFA displaced those indole uremic toxins in a manner similar to KP, which suggests that FFA also indirectly inhibits the S-enantiomer binding by increasing the unbound levels of indole uremic toxins. Thus it is likely that combined direct and cascade effects of transiently increased FFA and unbound indole uremic toxins contributed to the preferential elevation of the pharmacologically active S-KP fraction in uremic patients at the end of hemodialysis.