Gap junction protein beta 1 (GJB1) mutations and central nervous system symptoms in X-linked Charcot-Marie-Tooth disease

OBJECTIVES

To clarify the clinical variability, including central nervous system (CNS) involvement, in X-linked Charcot-Marie-Tooth disease (CMTX) patients.

MATERIAL AND METHODS

We clinically, pathologically and genetically studied six CMTX patients with distinct symptoms and four different GJB1 mutations.

RESULTS

One patient with Val63Ile had deafness, low intelligence, saccadic eye movement, upper extremity distal dominant muscle weakness and normal sensation. Another patient with Glu186Lys had severe sensorineural deafness at the age of 6 years, but did not develop muscle weakness until the age of 20 years. Two patients with Arg22Gln had typical CMT1A-like clinical features, no CNS symptoms and obvious onion bulb formations. Two siblings with deletion of the entire GJB1 gene had mild to moderate lower extremity muscle weakness and sensory disturbance without CNS involvement.

CONCLUSION

These findings suggest that some gain of function mutations of GJB1 may be related to CNS symptoms because the patients with GJB1 deletion only had peripheral neuropathy, although other unknown associated factors may contribute to their clinical phenotypes.

Current techniques of hyperthermic isolated limb perfusion for malignant melanoma

A retrospective study was conducted examining 25 patients with malignant melanoma who were treated by our new protocol for hyperthermic isolated limb perfusion. The characteristics of our techniques include: a lower priming volume of the extracorporeal circuit; a therapeutic temperature range of 40-41 degrees C with 60 min hyperthermic perfusion; a nominal perfusion flow rate of 500 ml/min in the lower limb and 200 ml/min in the upper limb; and combined carboplatin with interferon-beta as the adjuvant chemotherapy drug. In the lower extremity group, the arterial cannula size ranged from 8 to 14 F, while the venous cannula size ranged from 14 to 16 F. In the upper limb group, the arterial cannula size ranged from 6 to 8F and the venous cannula size ranged from 10 to 12F. No patient required any homologous blood transfusion postoperatively. No operative death or major complications occurred during the early postoperative period, confirming the safety of this treatment. Both optimal cannula size selection and maintaining perfusion temperature below 41 degrees C were judged to be important in elimination of vascular and deep tissue injury.

[Tracheopulmonary-subcutaneous fistula associated with anaerobic subcutaneous abscess on mechanical ventilator support in a patient with Duchenne muscular dystrophy]

A 29-year-old Japanese man with Duchenne muscular dystrophy was placed on a mechanical ventilator support at 23 years of age and admitted to our hospital at 25 years of age. He had severe neck contracture deviated to the left side which resulted in dysphagia and microaspiration. At 29 years of age, he developed left lobar pneumonia accompanied by slight fever, back pain and a foul odor from the patient's sputum. Although the patient received broad spectrum antibiotics, pneumonia disseminated to the right lung. A week later, chest computed tomography was conducted which revealed tracheopulmonary-subcutaneous fistula, and a massive subcutaneous abscess with free air production. Drainage from the subcutaneous abscess was done through a chest tube; however, respiratory hypercapnia was not corrected and the patient died. From the culture of drained fluid, anaerobic bacteria including peptostreptococcus sp. were detected. This tracheopulmonary-subcutaneous fistula was thought to be caused by chronic microaspiration of mouth anaerobes, mechanical injury of the trachea under long term ventilator support, and decreased deep back muscle bulk with substitution of adipose tissue around the chest.

Risk factors for posttransfusion graft versus host disease, mediastinitis, and late cardiac tamponade in heart surgery. Survey of 119 Japanese institutions

OBJECTIVE

Correlations and risk factors remain to be unclarified for post-heart-surgery posttransfusion graft-versus-host disease, mediastinitis, and late cardiac tamponade caused by deteriorated host-defense mechanisms due to cardiopulmonary bypass both with and without steroid usage.

METHODS

We sent questionnaires to 298 Japanese cardiovascular institutions asking for institution profiles, including infection control, steroid use in cardiopulmonary bypass, and prevalence of mediastinitis, late cardiac tamponade, and posttransfusion graft-versus-host disease during 1994. The overall prevalence of posttransfusion graft-versus-host disease since the start of service (from establishment of institution to date) was also requested.

RESULTS

The number of pump cases at the 119 institutions responding (40%) were 91.6 +/- 67.9 cases/institution (total = 10,904). The prevalence of mediastinitis was 1.2 +/- 1.8 and that of late cardiac tamponade 1.0 +/- 1.8%. Posttransfusion graft-versus-host disease occurred in 1 of 10,904 patients (0.01%) during 1994 at an institution where steroids and nonirradiated blood were used in surgery. The simple institutional mean prevalence of posttransfusion graft-versus-host disease since establishing institutions was 0.08 +/- 0.13%. Of the 119 institutions surveyed, 86 used steroids in all pump cases (72%); 11 institutions used steroids in a limited number of cases (9%). The institutional mean of methylprednisolone-converted steroid dose was 21.5 +/- 16.4 mg/kg (n = 119). In multivariate regression analysis, operation time (p = 0.005) for mediastinitis, steroid usage (all, limited, or no cases) (p = 0.01) and % aneurysm (p = 0.05) for late cardiac tamponade, and steroid dosage (p = 0.002) for posttransfusion graft-versus-host disease were identified as significant risk factors.

CONCLUSION

Our results suggest that massive steroid administration for cardiopulmonary bypass may increase the risk of posttransfusion graft-versus-host disease and late cardiac tamponade, but not mediastinitis.

Fractionated dosing of cyclophosphamide for establishing long-lasting skin allograft survival, stable mixed chimerism, and intrathymic clonal deletion in mice primed with allogeneic spleen cells

BACKGROUND

Injection of allo-spleen cells (SC) followed by a single dose of cyclophosphamide (CP) can induce tolerance of tumor and/or skin allografts in mice. To minimize the damage caused by CP, fractionation of CP that can establish long-lasting skin graft survival, stable mixed chimerism, and intrathymic clonal deletion in the host was investigated in the present study.

METHODS

Allo-SC (10(8)) were given intravenously on day 0. CP at 200 mg/kg was given intraperitoneally on day 2 in a single dose (CP 200x1 group). CP at 100, 66, 50, 40, and 33 mg/kg was given daily from day 1 through days 2, 3, 4, 5 and 6, respectively, in the fractionated doses (CP 100x2, 66x3, 50x4, 40x5, and 33x6 groups; total dose=200 mg/kg). Allografting was performed on day 14.

RESULTS

In a fully allogeneic combination of C57BL/6 (H2b)-->AKR (H2k, Mls-1a), an EL-4 tumor (H2b) was specifically accepted to kill the AKR mice in all of the SC+CP 200x1, 100x2, 66x3, 50x4, 40x5, and 33x6 groups (n=6), but C57BL/6 skin graft survival was not prolonged in any of the tumor-tolerant groups. In an H2-identical combination of AKR-->C3H (H2k, Mls-1b), AKR skin graft survival was prolonged remarkably (80-90 days) in the SC+CP 200x1, 100x2, and 66x3 groups (n=5-11), but was prolonged moderately (20-60 days) in the SC+CP 50x4 and 40x5 groups. In both of the SC+CP 200x1 and 66x3 groups in the AKR-->C3H combination, mixed chimerism was maintained for as long as 100 days after tolerance induction in both the spleen and thymus, associated with intrathymic clonal deletion of Vbeta6+ T cells. The decreases in leukocyte count, hemoglobin level, spleen weight, SC count, and body weight were significantly smaller in the SC+CP 66x3 group than in the SC+CP 200x1 group.

CONCLUSIONS

Fractionated CP is effective in ameliorating the compromised state induced by a single dose of CP. To induce a long-lasting skin allograft survival associated with stable mixed chimerism and intrathymic clonal deletion in an H2-identical combination, 200 mg/kg of CP can be divided into three or fewer fractions.

Kinetics of immunological parameters in patients with malignant melanoma treated with hyperthermic isolated limb perfusion

Kinetics of immunological parameters such as natural killer (NK) cell activity and tritium-thymidine uptake rate of T lymphocytes by phytohemagglutinin stimulation were investigated using peripheral leukocyte fractions of melanoma patients treated with hyperthermic isolated limb perfusion (HILP). Also, serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) were quantified during and after HILP. It was found that NK cell activity was augmented during HILP, and T lymphocyte function was stimulated 24 h and 1 week after HILP with statistical significance. NK cell activities in the cells isolated from perfused and non-perfused circulations were equally augmented during HILP in two patients examined. Serum concentrations of sICAM-1 in the patients who received HILP also increased 24 h or even 1 week after HILP. The stimulation of these immune competent cells and upregulation of sICAM-1 by HILP were independent of the stages of melanoma patients at the time of HILP or the doses of agents which were used for the infusion during HILP. The origin of cells which shed sICAM-1 into the serum of the patients who received HILP remains to be further investigated.

Synergistic immunosuppression caused by high-dose methylprednisolone and cardiopulmonary bypass

BACKGROUND

Steroid use during cardiac operations may reduce the risk of postperfusion lung syndrome, but both cardiopulmonary bypass and steroids are immunosuppressive. The synergistic effects of the bypass and steroids on patients' immunologic activities, hemodynamics, and metabolisms during and after heart operations have not been clarified systematically.

METHODS

Twenty-four patients undergoing valve replacement were studied in a randomized, double-blind trial. Twelve of these patients (S group) received bolus methylprednisolone, 20 mg/kg body weight, and the remaining 12 patients (C group) received a placebo intravenously before and after bypass. Blood cell count, C-reactive protein, lymphocyte surface markers (CD3, CD4, CD8, CD16, and CD20), phytohemagglutinin response, interleukin-2 production, and natural killer cell activity were examined on admission through day 7. Cardiac output, blood gas, electrolyte, lactate, and serum glucose levels were examined perioperatively.

RESULTS

The peak white blood cell count in the S group was higher than that in the C group (analysis of variance: p [group] = 0.0436). The peak C-reactive protein level was higher in the C group than in the S group (p [group] < 0.0001). From the analysis of the surface markers, the steroid increased the natural killer cells before and soon after bypass (p [group] = 0.0117), and later tended to increase the CD4+ T and B cells during the postoperative recovery period. The phytohemagglutinin response in both groups decreased after bypass (p [time] < 0.0001), but the steroid caused exaggerated decreases before (p < 0.01 by Student's t test) and soon after (p < 0.001) bypass in the S group (analysis of variance: p [group] = 0.0127). The interleukin-2 production was suppressed by bypass alone after the bypass in the C group, but was further suppressed by the steroid before and after bypass in the S group (p [group] = 0.0446). The cardiac index, water balance, electrolytes, arterial oxygen tension, and timing of extubation were not different between the groups. In contrast, the glucose (p [group] = 0.0486) and lactate (p [group] = 0.0525) levels were higher in the S group than those in the C group.

CONCLUSIONS

T-cell functions are synergistically suppressed by cardiopulmonary bypass and high-dose methylprednisolone in heart operations. The hemodynamic benefits of the steroid are negligible, whereas glucose tolerance is worsened by the steroid during bypass.

[Cyclophosphamide-induced immunological tolerance: an overview]

A cyclophosphamide (CP)-induced tolerance system in mice that primarily consists of donor cell injection followed by CP-treatment was found useful for inducing a long-lasting allo- or xeno-tolerance to various solid organs. In the cells-followed-by-CP system, the sequential mechanisms of the tolerance were clarified using the specific correlation between superantigens and certain T cell receptor (TCR) V beta segments. Those include the clonal destruction of antigen-stimulated mature T cells, the peripheral clonal deletion associated with peripheral chimerism, the intrathymic clonal deletion associated with intrathymic chimerism, and the clonal anergy. The generation of suppressor T cells was another important mechanism of the tolerance in the late stage. Special care taken to overcome the "hard" barriers of allo-or xeno-combinations by reducing the "split tolerance" produced through the clonal destruction mechanism. For this purpose, the tolerogen, antimitotic drug their doses, timing, route of administration, combined immunosuppressants, and supportive treatment were all crucial for successful induction of a long-lasting skin tolerance. This system may be applicable to human transplantation.

Use of automatic mode change between DDD and AAI to facilitate native atrioventricular conduction in patients with sick sinus syndrome or transient atrioventricular block

The benefits of the automatic DDD (DDD/AMC) mode in the Chorus II pacemaker (Chorus 6234; Ela Medical Inc.), which automatically switches the modes between DDD and AAI to respect spontaneous AV conduction as much as possible in AAI while preserving safety pacing in DDD during paroxysmal AV block (AVB) only, remain unproven. This study examined the functions of the DDD/AMC mode in 12 patients with sick sinus syndrome (SSS; n = 10) or paroxysmal complete AVB (n = 2). A short-term (24 hours) comparative study between simple DDD mode and the DDD/AMC mode was performed in 8 of the 12 patients, and a medium-term (55.2 +/- 54.6 days) follow-up of the DDD/AMC mode was completed in all 12 patients. A comparative pair of 24-hour surface Holter ECGs was obtained in 6 of the 8 patients in the short-term study. Telemetry and built-in Holter histograms were collected in the outpatient clinic in all 12 patients. Although the percentage atrial pacing of the telemetry increased from 59.2 +/- 35.4 in DDD to 70.4 +/- 31.8 in DDD/AMC (P < 0.009; n = 8), the percentage ventricular pacing decreased from 64.6 +/- 37.7 in DDD to 36.2 +/- 43.1 in DDD/AMC (P < 0.027) in the short-term study. In particular, the reduction of percentage ventricular pacing to < 10% was observed in four patients with SSS not associated with > or = first-degree (1 degree) AVB on preoperative ECGs. Between the two modes a significant difference in arrhythmic events was not observed by the 24-hour surface Holter ECGS taken from the six patients in the short-term study. AAI-DDD switching associated with automatic modulation of AV delay and AV hysteresis occurred in all patients in the medium-term study. From the medium-term study, the total AV delay (AV delay plus AV hysteresis) exceeded 300 ms in 6 of the 12 patients in DDD/AMC, and usually became longest during nighttime. From the short- or medium-term study in the 12 patients, two patients preferred the DDD/AMC mode while one preferred the DDD mode. These results suggest that the DDD/AMC mode is useful, at least in SSS patients without > or = 1 degree AVB, by reducing the percentage ventricular pacing.

Effectiveness and limitations of the fallback I algorithm for transient supraventricular tachyarrhythmias in DDD pacing

To examine the function of the fallback I algorithm (Chorus I, Ela Medical Inc., Montrouge, France), which automatically changes the DDD mode to VDI during transient supraventricular tachyarrhythmias to prevent high-rate tracking of the venticule, a total of 45 patients who were preoperatively diagnosed with sick-sinus syndrome (SSS) (Group 1; n = 19) or with advanced or complete atrioventricular block (AVB) (Group 2; n = 26) were followed up and analyzed. Mean follow-up times (mean +/- SD) were 22.4 +/- 9.7 and 12.4 +/- 10.9 months, respectively. Each of the groups was further divided into subgroups according to the preoperative existence of of paroxysmal atrial fibrillation (PAF) or paroxysmal supraventricular tachyarrhythmia (PSVT). During follow-up, the fallback started through a given cycle of ventricular pacing at a upper-rate limit (URL) to avoid a continuous high-rate tracking during the arrhythmias specifically in the patients with PSVT (0/4) (p = 0.0004). The fallback, however, sometimes started in the patients who had AVB not associated with either PAF or PSVT (4/21) during normal exercise because the fallback algorithm did not distinguish a normal P wave from the abnormal atrial waves. To further clarify the behavior of the fallback, a treadmill test was conducted in 25 of the 45 patients. The fallback start was observed in 12 of the 17 patients with AVB (Group 2). In such patients, the use of a long fallback delay and/or a high URL setting prevented the fallback starts during normal exercise. These results suggest that, in DDD pacing, the algorithm in Chorus I is useful in patients with SSS or AVB to avoid highrate tracking of the ventricle during transient supraventricular tachyarrhythmias, but special care must be taken to avoid the fallback starts during the normal exercise in AVB patients.

Cyclophosphamide-induced immunological tolerance: an overview

A cyclophosphamide (CP)-induced tolerance system in mice that primarily consists of donor cell injection followed by CP-treatment was found useful for inducing a long-lasting allo- or xeno-tolerance to various solid organs. In the cells-followed-by-CP system, the sequential mechanisms of tolerance were clarified using the specific correlation between superantigens and certain T cell receptor (TCR) V beta segments. Those include the clonal destruction of antigen-stimulated mature T cells, the peripheral clonal deletion associated with peripheral chimerism, the intrathymic clonal deletion associated with intrathymic chimerism, and the clonal anergy. The generation of suppressor T cells was another important mechanism of tolerance in the late stage. Special care was taken to overcome the " hard" barriers of allo- or xeno-combinations by reducing the "split tolerance" produced through the clonal destruction mechanism. For this purpose, the tolerogen, antimitotic drugs, their doses, timing, route of administration, combined immunosuppressants, and supportive treatment were all crucial for successful induction of a long-lasting skin tolerance. This system may be applicable to human transplantation.

The relationship between functional class, pulmonary artery pressure and size in left atrial myxoma

To examine the correlation between the size of left atrial myxoma, the degree of pulmonary hypertension and the patient's New York Heart Association (NYHA) functional class, the records of 29 surgically treated patients with left atrial myxoma were reviewed. Of 29 patients, 23 were catheterized before surgery. As the preoperative NYHA functional class advanced, the preoperative mean pulmonary artery pressure (mmHg) was seen to increase. Moreover, the weight of the excised myxoma also correlated well with the preoperative pulmonary artery pressure value. In five patients inserted with a Swan-Ganz catheter, the mean pulmonary artery pressure decreased immediately after tumour excision. Postoperatively, the average NYHA class of the 29 patients significantly improved. These results confirmed the positive correlation between the size of the tumour, the pulmonary artery pressure, and NYHA class in patients with left atrial myxoma.

Donor-specific prolongation of rat skin graft survival induced by rat-donor cells and cyclophosphamide under coadministration of monoclonal antibodies against T cell receptor alpha beta and natural killer cells in mice

Because of the recent interest in human xenotransplantation, we investigated the possibility of inducing tolerance in a xenogeneic combination using cyclophosphamide (CP). Donor-specific prolongation of xenogeneic Fisher 344 (F344) rat skin graft survival for up to 60 days was induced in C57BL/6 (B6) mice by giving F344 bone marrow cells and spleen cells on day 0, CP on day 2, and monoclonal antibodies against murine TCR-alpha beta and NK1.1 on days--1 and 3. The inoculation of the xenogeneic cells brought accelerated repopulation of TCR-alpha beta+ T cells, even under the administration of anti-TCR-alpha beta mAb. The quick increase of the host TCR-alpha beta+ T cells caused by the xenogeneic cell injection was deeply suppressed by CP. Mixed lymphocyte reaction, CTL activity, and antibody production against donor F344 were profoundly suppressed for 50 days. Mixed xenogeneic chimerism was observed for 1 month after the inoculation of donor cells in the spleen and peripheral blood of the recipient B6 mice, but was never observed in the thymus. Moreover, when irradiated F344 cells were used in place of viable cells, chimerism was never detected and graft survival was only slightly prolonged. Clonal deletion of V beta 5- or V beta 11-bearing murine T cells was not observed on day 50 in the thymus or spleen of the recipient B6 mice. These results suggest that treatment with viable xenogeneic donor cells, CP, and mAbs against T and NK cells can induce a temporary peripheral mixed chimerism and donor-specific prolongation of xenogeneic skin graft survival. The destruction with CP of T and B cells that are xenoreactive and thus proliferating after antigen stimulation, followed by mechanism other than intrathymic clonal deletion, may be the mechanism of the hyporesponsiveness in the present system.

Two cases of metastatic malignant melanoma of the lower limb treated with hyperthermic isolated limb perfusion and concomitant infusion of either carboplatin or beta-interferon

Two cases of metastatic malignant melanoma of the lower limb who were treated successfully with hyperthermic isolated limb perfusion are reported. One patient was infused with cisdiammine (1.1-cyclobutanedicarboxylate) platinum (II) (carboplatin, Paraplatin, Bristol-Myers Squibb Company, New Jersey, USA), and the other was infused with human natural beta-interferon (Feron, Toray, Tokyo, Japan), via the external iliac artery. The first case showed a remarkable suppression of the growth of multiple metastatic melanoma nodules associated with numerous melanophage infiltrations, as shown histopathologically after the operation. The patient's serum level of 5-S-cysteinyl dopa decreased for the two months following the treatment. In the second case, new formation of metastatic melanoma nodules was completely suppressed for up to 12 months following the operation. Analysis of immunological parameters showed that the number of peripheral CD8+ lymphocytes gradually and constantly increased after the operation, while that of CD4+ lymphocytes transiently increased and then returned to the pre-operative level. Natural killer activity transiently decreased to a slight degree 4 days after the operation and then returned to the pre-operative level 21 days after the operation. Side effects, such as nausea, vomiting and leg discomfort, were seen in the patient (Case 1) treated with carboplatin, but were completely reversible. These results suggest that hyperthermic isolated limb perfusion with concomitant infusion of carboplatin or beta-interferon is effective in suppressing the growth of metastatic malignant melanomas of the lower limb.

Left atrial myxoma associated with severe congestive heart failure, pulmonary hypertension, and multiple organ insufficiency

We have experienced a case of left atrial (LA) myxoma with rapid progression of congestive heart failure and ensuing multiple organ insufficiency. After the tumor excision, the hemodynamic derangement was totally corrected and the patient dramatically recovered from kidney, liver, and lung insufficiency. Specifically, pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), and central venous pressure (CVP) significantly decreased in the intensive care unit. Administration of prostaglandin E1 (PGE1) was effective in treating residual pulmonary hypertension.

Simplified Manouguian's aortic annular enlargement for aortic valve replacement

A simplified Manouguian's aortic annular enlargement for aortic valve replacement with prosthetic valve was performed in a patient with severe aortic stenosis and mild regurgitation by preserving both the anterior mitral leaflet and the left atrial roof intact. This method minimized the operative risk by avoiding injury to the mitral valve, while inserting a possibly two-size-larger prosthetic valve. The inserted prosthetic valve was positioned parallel to the original aortic valve. Moreover, the incision from the top of the commissure between the noncoronary cusp and left coronary cusp through the interventricular fibrous trigone appears to be easily extended into the exact center of the anterior mitral leaflet if further enlargement is required.

Left ventricular-coronary sinus shunt through a septal aneurysm after mitral valve re-replacement

We describe a case in which a left ventricular-coronary sinus communication through a dissecting ventricular septal aneurysm developed after a redo mitral valve replacement. The outlet orifice of the communication was located in the side wall of the ostium of the coronary sinus. Both the communication and the aneurysm were successfully dealt with by performing a right atriotomy and by opening the aneurysm from its outlet orifice.

Hyperthermic isolated limb perfusion with intra-arterial administration of carboplatin and/or interferon-beta for the treatment of malignant melanoma of the leg

Our experiences of hyperthermic isolated limb perfusion with administration of carboplatin, interferon-beta or a combination of both are reported. Administration of high doses of these reagents was well tolerated by patients with melanoma without severe complications after the treatment. A total of 8 patients underwent this therapeutic modality. Remarkable clinical improvement was seen in the first patient, who was in Stage III at the time of the perfusion. Histopathological findings indicated severe damage to the melanoma cells after the operation. Prophylactic hyperthermic perfusion was performed in 6 other patients with Stage II-III melanoma of the lower limb. None of them have shown any signs of recurrence 1-10 months later. The activities of natural killer cells or T lymphocytes appeared to be increased when the perfusion was carried out with concomitant administration of both carboplatin and interferon-beta. These results suggest that hyperthermic isolated limb perfusion with carboplatin and/or interferon beta administration is effective in patients with advanced stage melanoma.

Drug infusion through a branch of the aortocoronary vein graft for refractory coronary spasm

We describe two cases of coronary artery spasm that occurred during open heart operations and were treated by coronary artery bypass grafting. Vasodilators and calcium antagonists were infused directly into the right coronary artery via the side branch of the saphenous vein graft. Both patients were weaned successfully from cardiopulmonary bypass.

The efficacy of fluconazole in treating prosthetic valve endocarditis caused by Candida glabrata: report of a case

A case of active prosthetic valve infective endocarditis (PVE) due to Candida glabrata was successfully treated by the systemic administration of fluconazole. A 66-year-old Japanese man with infective endocarditis of unknown etiology underwent aortic and mitral valve replacement to treat severe aortic and mitral regurgitation associated with multiple organ failure. Postsurgical cultures of arterial blood were repeatedly positive for C. glabrata, and therefore fluconazole was administered either intravenously or orally at a dose of 400 mg/day for 46 days. During that time the signs of inflammation including fever such as an elevated white blood cell count and the presence of C-reactive protein (CRP) all improved while the blood cultures became negative. Fluconazole is thus considered to be effective in treating PVE caused by C. glabrata. When administering this treatment, it is also important to monitor the patient's renal and liver function.

[Clinical assessment of complement activation and leukocyte kinetics during cardiopulmonary bypass: the effect of cepharanthine]

Complement activation and leukosequestration to the lung was studied during cardiopulmonary bypass in eleven patients undergoing cardiac operation without blood transfusion. Six patients (group I) received methylprednisolone before and after the bypass, and the other five (group II) received cepharanthine (biscoclaurin alkaloid) before the bypass associated with methylprednisolone therapy. Leukosequestration to the lung was observed at the time of reperfusion of the lung only in group I, although complement activation estimated by the increase of C 4 a and C 3 a was quite similar in both group. Cepharanthine prevented the sequestration of the leukocyte to the lung may be by its membrane stabilizing effect.

Use of a dual chamber pacemaker with a novel fallback algorithm as an effective treatment for sick sinus syndrome associated with transient supraventricular tachyarrhythmia

A dual chamber pacemaker having a fallback (FB) mode was utilized in nine patients with sick sinus syndrome (SSS) associated with transient supraventricular tachyarrhythmia (atrial fibrillation [Af] in three patients, atrial flutter [AF] in two, and paroxysmal atrial tachyarrhythmia [PAT] in four). Various degrees of abnormality of atrioventricular (AV) conduction were observed at the time of pacemaker implantation in five patients. In this pacemaker, a DDD mode was active during sinus rhythm, but the mode changed, through a given cycle of high rate tracking at an upper rate limit (URL), to VDI only during intrinsic atrial rate increases that were either normally or abnormally above the URL. The VDI mode automatically returned to DDD when the atrial rate fell below the URL. At follow-up periods of 7-12 months, this pacemaker appeared to be especially effective in those SSS patients with transient Af or AF. In the SSS patients with PAT, however, the FB mode was not active because the PAT rhythm was conducted to the ventricle without block (1:1 conduction) and thus the given cycles of ventricular tracking at the URL did not occur. From the repetitive FB starting tests that were performed during an Af period in one patient with transient Af, a 2:1 point setting of a given URL plus 30-50 ppm was required to quickly start the FB algorithm. Moreover, an atrial sensitivity setting that was less than half of the P wave amplitude was desirable.(ABSTRACT TRUNCATED AT 250 WORDS)

Collins' solution for cold storage of the heart for transplantation must be reversed with cardioplegic solution before reperfusion. A functional and metabolic study in the rat heart

The following hypotheses were tested using an isolated perfused working rat heart model: (1) Collins' solution for cold storage of the heart is harmful for the heart during reperfusion; (2) a "reverse" of the intracellular-type Collins' solution with an extracellular-type cardioplegic solution before reperfusion is able to prevent this disadvantage of Collins' solution. The following two major groups (I and II) and five subgroups (-a to -e) in each group were prepared. In group I (reversed group); the hearts were initially stored in Collins' solution but were reversed by a 1-minute flush with cardioplegic solution followed by storage in cardioplegic solution for the last 1 to 180 minutes of the total 3-hour storage, that is, groups I-a (reversed for 1 minute), I-b (10 minutes), I-c (30 minutes), I-d (90 minutes), and I-e (180 minutes). In group II (nonreversed control group); the hearts were stored in Collins' solution throughout 3 hours and were also divided into five subgroups of groups II-a, II-b, II-c, II-d, and II-e in which only a 1-minute flush with Collins' solution was performed at the point corresponding to group I. The coronary flow in any of group II showed a marked decrease during the early reperfusion period. In group I, however, the coronary flow increased significantly in proportion to the duration of the reversing phase. The recovery of the aortic flow and the cardiac output in group I showed a bell-shaped pattern in relation to the duration of the reversing phase, reaching their peak values when reversed for 30 minutes (group I-c). The prolonged reverse (180 minutes) resulted in a deterioration of functional recovery associated with a poorer preservation of high-energy phosphates and a larger enzyme leakage. These results suggest that the beneficial effects of intracellular-type Collins' solution for cold storage of the heart were further improved by reversing Collins' solution with the extracellular-type cardioplegic solution for the last 30 minutes of the 3-hour cold storage because the disadvantageous vasoconstriction due to Collins' solution during reperfusion was successfully prevented by the replacement of intravascular and extravascular Collins' solution with cardioplegic solution before the reperfusion.

The myocardial recovery mode after cold storage for transplantation with Collins' solution and cardioplegic solution. A functional and metabolic study in the rat heart

Mechanisms and kinetics of the effects of the ionic composition of two different storage solutions, an intracellular type and an extracellular type, were analyzed by examining the myocardial functional and metabolic recovery processes during the early reperfusion periods after 3 hours of cold storage using an isolated perfused working rat heart model. The hearts were stored either in our own cardioplegic solution (group 1) or in Collins' solution (group 2) for 3 hours at 4 degrees C and were then reperfused. The electromechanical activity in group 1 was elevated, as indicated by a higher incidence of ventricular fibrillation at 5 minutes of reperfusion (group 1: 5/6; group 2: 0/5; p < 0.05). The coronary flow rate in group 2 was significantly lower, at least for the first 15 minutes after reperfusion, than that of group 1, suggesting the possible existence of vasoconstriction in group 2. Although myocardial oxygen uptake during this period was smaller in group 2, the recovery of myocardial high-energy phosphate levels was better and creatine kinase leakage was less in group 2. The recovery of aortic flow after 30 minutes of reperfusion was significantly better in group 2 (group 1, 59.1 +/- 5.8%; group 2, 71.7 +/- 6.0%; p < 0.01), although the early recovery was somewhat worse in group 2. These data suggest that the heart stored in an intracellular-type solution, compared with one stored in an extracellular-type solution, recovers in an electromechanically suppressed fashion during the early reperfusion phase, associated with a better metabolic recovery and a slower but larger functional recovery. The disadvantage of the intracellular-type solution, however, may be its effect on the increase of coronary vascular resistance during the early reperfusion period.

Pretreatment with H2 blocker famotidine to ameliorate protamine-induced hypotension in open-heart surgery

An antagonist to H1 histamine receptor and one to H2 histamine receptor were used to prevent protamine-induced hypotension in 126 Japanese patients undergoing open heart surgery. In a study comparing an H1 antagonist "diphenhydramine" and an H2 antagonist "famotidine", 103 patients were divided into four groups: 31 patients were given no drugs (Group 1), 25 patients were given 0.4 mg/kg of diphenhydramine (Group 2), 33 patients were given 0.4 mg/kg of famotidine (Group 3), and 14 patients were given both the drugs (Group 4) before protamine administration. Although the systolic arterial pressure decreased significantly after protamine administration in all groups, famotidine was found to be effective in reducing protamine-induced hypotension, whereas diphenhydramine was not effective. In order to further investigate the hemodynamic changes in a double-blinded fashion, 12 patients were given normal saline (Group 5), while 11 patients were given 0.4 mg/kg of famotidine (Group 6) before protamine administration. Again, the minimal systolic and mean arterial pressures after protamine injection were significantly higher in Group 6 than in Group 5, while left atrial pressure, central venous pressure, heart rate, and cardiac index were almost the same and remained constant in the two groups. These results strongly suggest that the H2 antagonist "famotidine" is beneficial in reducing protamine-induced hypotension after cardiopulmonary bypass, while the H1 antagonist "diphenhydramine" is not.

[Effects of open-heart surgery on renal function in patients with chronic renal failure--is hemodialysis during cardiopulmonary bypass really required?]

In 300 consecutive adult patients who underwent open-heart surgery in our department, 16 patients (ischemic heart disease in 8 patients, valvular heart disease in 7 and congenital heart disease in 1) were preoperatively complicated with chronic renal failure (CRF); creatinine clearance (Ccr) < 40 ml/min and serum creatinine (Scr) > 1.6 mg/dl. The effects of open-heart surgery on renal function were studied in these CRF patients who were divided into the following 3 groups according to their preoperative Ccr values: Group 1 (6 patients), 30 < Ccr < 40 ml/min; Group 2 (5 patients), 20 < Ccr < 30 ml/min; and Group 3 (5 patients, 4 of whom were on dialysis preoperatively), Ccr < 10 ml/min. In addition, Group C (38 patients, Ccr > 50 ml/min) was set up as normal controls. Instead of hemodialysis, the extracorporeal ultrafiltration method (ECUM) was employed for all patients during the cardiopulmonary bypass (CPB). The Ccr in Group 1 showed the lowest value of 24.2 +/- 12.0 ml/min on postoperative day (POD) 0 which then recovered to the preoperative level on POD 1. This quick recovery of the Ccr in Group 1 was similar to that in Group C. In contrast, the Ccr in Group 2 showed the lowest value of 13.0 +/- 6.0 ml/min on POD 1, followed by a delayed recovery that did not reach the preoperative level until POD 5. The Ccr in Group 3 was quite low (< 5 ml/min) throughout the test period.(ABSTRACT TRUNCATED AT 250 WORDS)

[Valve repair for mitral regurgitation due to ruptured chordae tendineae--repaired valve function and late results]

Among 21 consecutive patients with significant mitral regurgitation due to ruptured chordae tendineae operated by an author (K.M.) between March, 1980 and August, 1990, the 18 patients who underwent mitral valve repair were studied to assess the repaired valve function and late results of the repair. The chordal rupture was due to idiopathic degenerative disease in 14 patients, infective endocarditis in three and trauma in one. Patients' ages ranged from 35 to 70 years (mean age 52). Nine patients were in New York Heart Association class II and the remaining nine in class III. In three patients with ruptured chordae of the anterior mitral leaflet, reconstruction of the chordae with xenograft pericardium was performed in two patients and partial closure of a commissure in one. In 15 patients with ruptured chordae of the posterior leaflet, Kay's repair was performed in 13 patients and leaflet resection technique in two. In addition to the chordal and leaflet repairs, Kay's mitral annuloplasty was performed in all. There was no hospital death and all patients showed significant hemodynamic improvement (systolic pulmonary arterial pressure from 43 +/- 20 mmHg preoperatively to 24 +/- 4 mmHg postoperatively, and pulmonary arterial wedge pressure from 17 +/- 10 mmHg to 6 +/- 3 mmHg, p less than 0.001 respectively). The repaired valves showed mild pressure gradient of 3.1 +/- 1.2 mmHg which was significantly lower than the gradient of 6.6 +/- 3.5 mmHg of SJM prostheses. Residual murmur was documented in six patients, in three of whom, however, the murmur disappeared within one year following the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Constant intravenous infusion of chlorpromazine for both sedation and after-load reduction in postcardiotomy patients under intraaortic balloon pumping

Continuous intravenous infusion of chlorpromazine (CPZ) was used for both sedation and after-load reduction in 13 Japanese patients (Group 1) supported by an intraaortic balloon pump (IABP) after open-heart surgery. CPZ was initiated at a dose of 0.05 mg/kg/hr and was maintained in an approximate dose range of 0.1-0.3 mg/kg/hr depending on individual patient needs. The drug was administered until the IABP was removed and the blood gases were normalized. During this period, the patients slept well and the trigger lines for the IABP were sufficiently secured. In order to evaluate the hemodynamic changes in these patients, the 10 patients who were supported by the IABP and given continuous intravenous sodium thiamylal (ST) for sedation in an approximate dose range of 1-2 mg/kg/hr (Group 2) were employed as controls. After administration of CPZ, the systemic vascular resistance, central venous pressure, and left atrial pressure decreased, while the cardiac output increased. The predicted untoward effects of CPZ, such as tachycardia and hypotension, were minimal. In the ST group, by contrast, the cardiac output decreased somewhat in association with the increase in systemic vascular resistance. From these results, we conclude that constant intravenous CPZ is beneficial for postcardiotomy patients who have severe low cardiac output syndrome and are supported with IABP, by both successfully sedating the patients and reducing ventricular afterload.

[Postoperative complications and treatments after Bentall operation]

Postoperative complications of Bentall operation for the annuloaortic ectasia have frequently occurred, although the mortality has been reduced. To reduce complications after Bentall operation we have taken three major treatments since 1987. The first was reimplantation technique of coronary ostia in replacing the ascending aorta and the aortic valve with a tube graft. The second was the infusion technique of cardioplegic solution such as retrograde cardioplegia infusion. The third method was to save blood and reduce the blood transfusion by preserving autoblood preoperatively and using cell saving machine. The purpose of this study was to analyse 20 patients who underwent the Bentall procedure and to investigate the effect of our treatments in Bentall operation on the operative results. We divided our patients into two groups. Fourteen patients in the group 1 were operated before 1987, when our principles were not performed. Six patients in group II were operated under the principles mentioned above. There were no differences in cardiopulmonary bypass time and ischemic time between group I and II. Transfused blood volume in group II was remarkably less than that of group I. Postoperative complications occurred in all patients in group I (100%), while three patients in group II (50%) had complications (p less than 0.05). We, hence, conclude that our method could be useful for reducing postoperative complication rate in Bentall operation.

Novel method of valve replacement with interrupted sutures using protractor rings for the partitioning of a prosthetic sewing ring

Newly devised protractor rings that can equally partition a prosthetic valve sewing ring into 10-20 acrs have been used on 46 patients who underwent 59 aortic, mitral, and/or tricuspid valve replacement. After an appropriate number of interrupted mattress sutures were placed along the host annulus, one of the 11 protractor rings was chosen and used to copy the partition onto the sewing ring with a tissue pen. The interrupted mattress sutures kept on a suture holder were then passed through the prosthetic sewing ring directly from one end to the other. Based on ex vivo experiments in simulating valve replacement, it was evident that time required for placing sutures around the sewing ring was significantly shortened by the use of such protractor rings. The use of these protractor rings may thus be useful in decreasing valve replacement time as well as in potentially simplifying operative procedures.

Similarity and difference in the mechanisms of neonatally induced tolerance and cyclophosphamide-induced tolerance in mice

The mechanisms of cyclophosphamide (CP)-induced tolerance were investigated by comparing with those of neonatally induced tolerance. When C3H/He Slc (C3H; H-2k, Mls-1b) mice were given i.v. either AKR/J Sea (AKR; H-2k, Mls-1a) or (AKR x C3H)F1 (AKC3F1; H-2k, Mls-1a/b) spleen cells and treated i.p. with CP 2 days later, a long-lasting skin allograft tolerance to AKR was induced in each case without any signs of graft-vs-host disease (GVHD). However, typical signs of GVHD were observed in the C3H mice neonatally tolerized with AKR spleen cells, but not in those tolerized with AKC3F1 spleen cells. The expression of TCR V beta 6, which is strongly correlated with the reactivity to Mls-1a Ag (of donor AKR origin), in the periphery was quite different between the two types of tolerant C3H mice. Namely, in the lymph nodes of the C3H mice tolerized with AKR spleen cells and CP, only CD4(+)-V beta 6+, but not CD8(+)-V beta 6+, T cells selectively disappeared, whereas both of them were abrogated in the lymph nodes of the C3H mice neonatally tolerized of AKR. By contrast, in the thymus of the two types of tolerant C3H mice, both CD4+CD8- and CD4-CD8+ single-positive thymocytes expressing TCR V beta 6 were clonally deleted, suggesting that the thymic involvement was the same in each type of tolerance. These results suggest that the preferential disappearance of the CD4(+)-V beta 6+ T cells (of host origin) and the effector T cells of GVHD (of donor origin) occurred only in the periphery of the C3H mice tolerized with AKR spleen cells plus CP and was attributable to the destruction of Ag-stimulated T cells by the CP treatment. In contrast, the intrathymic clonal deletion of immature V beta 6+ T cells was a common mechanism for both of the tolerance induction systems.

Similarity and difference in the mechanisms of neonatally induced tolerance and cyclophosphamide-induced tolerance in mice

The mechanisms of cyclophosphamide (CP)-induced tolerance were investigated by comparing with those of neonatally induced tolerance. When C3H/He Slc (C3H; H-2k, Mls-1b) mice were given i.v. either AKR/J Sea (AKR; H-2k, Mls-1a) or (AKR x C3H)F1 (AKC3F1; H-2k, Mls-1a/b) spleen cells and treated i.p. with CP 2 days later, a long-lasting skin allograft tolerance to AKR was induced in each case without any signs of graft-vs-host disease (GVHD). However, typical signs of GVHD were observed in the C3H mice neonatally tolerized with AKR spleen cells, but not in those tolerized with AKC3F1 spleen cells. The expression of TCR V beta 6, which is strongly correlated with the reactivity to Mls-1a Ag (of donor AKR origin), in the periphery was quite different between the two types of tolerant C3H mice. Namely, in the lymph nodes of the C3H mice tolerized with AKR spleen cells and CP, only CD4(+)-V beta 6+, but not CD8(+)-V beta 6+, T cells selectively disappeared, whereas both of them were abrogated in the lymph nodes of the C3H mice neonatally tolerized of AKR. By contrast, in the thymus of the two types of tolerant C3H mice, both CD4+CD8- and CD4-CD8+ single-positive thymocytes expressing TCR V beta 6 were clonally deleted, suggesting that the thymic involvement was the same in each type of tolerance. These results suggest that the preferential disappearance of the CD4(+)-V beta 6+ T cells (of host origin) and the effector T cells of GVHD (of donor origin) occurred only in the periphery of the C3H mice tolerized with AKR spleen cells plus CP and was attributable to the destruction of Ag-stimulated T cells by the CP treatment. In contrast, the intrathymic clonal deletion of immature V beta 6+ T cells was a common mechanism for both of the tolerance induction systems.

A new aspect of coronary artery spasm induced by cardiac surgery

Five patients developed coronary artery spasm during open heart surgery in our institute between 1984 and 1988. One patient was undergoing coronary artery bypass grafting and the other four valvular surgery or surgery for congenital heart disease. In one of the patients undergoing non-coronary surgery, the preoperative induction of right coronary artery spasm by ergonovine had been documented angiographically while the remaining three patients did not possess organic or functional coronary disease. All five patients exhibited a sudden onset of hemodynamic collapse with ventricular tachyarrhythmias or ST elevation during the early period of reperfusion, the time to onset being 89.2 +/- 84.8 minutes after unclamping of the aorta. In addition, contraction of the right ventricular free wall was severely impaired. Although one patient died due to left ventricular rupture caused by direct cardiac massage, the early mortality thus being 20 per cent, the other four were successfully treated with the intravenous administration of nitroglycerin and diltiazem. Three patients required the assistance of intraaortic balloon pumping for severe cardiac failure. Thus, during open heart surgery, coronary artery spasm can occur even in patients without organic coronary lesions and the possible mechanisms of this condition are discussed herein.

[Informed consent in cardiac surgery]

Recently, it has been recognized in Japan that informed consent is indispensable to make decisions for medical treatment, although it had been already confirmed in western countries for several decades of years. However, there may be some differences in the content of informed consent between Japan and western countries. We discussed the problems of informed consent in Japan concerning the choice of prosthetic valve, mechanical prosthesis or bioprosthesis, in patients to be undergone valve replacement. We conclude that informed consent should be the humane relationship between therapists and a patient.

Recombinant human granulocyte colony-stimulating factor improves the compromised state of recipient mice without affecting the induction of specific tolerance in the cyclophosphamide-induced tolerance system

The effects of recombinant human granulocyte CSF (rhG-CSF) on cyclophosphamide (CP)-induced tolerance was studied. In the recipient C57BL/10 Sn Slc (B10) mice given 1 x 10(8) B10.BR Sg Sn Slc (B10.BR) spleen cells (SC) on day -2 followed by 200 mg/kg CP on day 0, the number of leukocytes and neutrophils in the periphery declined to their minimum levels on day 4. When rhG-CSF in a dose of 200 micrograms/kg was given daily for 5 days to the B10 mice, which had been treated with B10.BR SC and CP, starting one day after the administration of CP, the leukocyte and neutrophil counts declined to the same levels as those in the B10 mice treated with B10.BR SC and CP alone on day 2. On day 4, however, the counts recovered to their normal levels. The nucleated cell count of the spleen in the B10 mice given B10.BR SC and CP followed by rhG-CSF decreased less and recovered faster than that in the B10 mice given B10.BR SC and CP. The case was found to be the same in bone marrow, and the difference did not reach statistical significance. When the recipient mice were inoculated i.p. with 4 x 10(4) Pseudomonas aeruginosa (GNB-139) on day 4, the survival of the B10 mice treated with B10.BR SC and CP was markedly improved by rhG-CSF administration. The administration of rhG-CSF did not affect either the prolongation or the specificity of skin allograft survival, as shown in an H-2 mis-matched combination of B10.BR----B10 and in an H-2 identical combination of AKR/J Sea(AKR)----C3H/HeN Crj (C3H). The tolerant state, which was demonstrated by various immune responses, such as CTL, delayed footpad reaction, and antibody, was also not affected by rhG-CSF. Furthermore, the basic mechanisms for inducing a long-lasting skin allograft tolerance in this system--namely, the specific destruction of Ag-stimulated and then proliferating mature T cells in the periphery, the establishment of mixed chimerism, and the intrathymic clonal deletion of immature T cells--were preserved even when rhG-CSF was given to C3H mice previously made tolerant of AKR.

Recombinant human granulocyte colony-stimulating factor improves the compromised state of recipient mice without affecting the induction of specific tolerance in the cyclophosphamide-induced tolerance system

The effects of recombinant human granulocyte CSF (rhG-CSF) on cyclophosphamide (CP)-induced tolerance was studied. In the recipient C57BL/10 Sn Slc (B10) mice given 1 x 10(8) B10.BR Sg Sn Slc (B10.BR) spleen cells (SC) on day -2 followed by 200 mg/kg CP on day 0, the number of leukocytes and neutrophils in the periphery declined to their minimum levels on day 4. When rhG-CSF in a dose of 200 micrograms/kg was given daily for 5 days to the B10 mice, which had been treated with B10.BR SC and CP, starting one day after the administration of CP, the leukocyte and neutrophil counts declined to the same levels as those in the B10 mice treated with B10.BR SC and CP alone on day 2. On day 4, however, the counts recovered to their normal levels. The nucleated cell count of the spleen in the B10 mice given B10.BR SC and CP followed by rhG-CSF decreased less and recovered faster than that in the B10 mice given B10.BR SC and CP. The case was found to be the same in bone marrow, and the difference did not reach statistical significance. When the recipient mice were inoculated i.p. with 4 x 10(4) Pseudomonas aeruginosa (GNB-139) on day 4, the survival of the B10 mice treated with B10.BR SC and CP was markedly improved by rhG-CSF administration. The administration of rhG-CSF did not affect either the prolongation or the specificity of skin allograft survival, as shown in an H-2 mis-matched combination of B10.BR----B10 and in an H-2 identical combination of AKR/J Sea(AKR)----C3H/HeN Crj (C3H). The tolerant state, which was demonstrated by various immune responses, such as CTL, delayed footpad reaction, and antibody, was also not affected by rhG-CSF. Furthermore, the basic mechanisms for inducing a long-lasting skin allograft tolerance in this system--namely, the specific destruction of Ag-stimulated and then proliferating mature T cells in the periphery, the establishment of mixed chimerism, and the intrathymic clonal deletion of immature T cells--were preserved even when rhG-CSF was given to C3H mice previously made tolerant of AKR.

Specific destruction of host-reactive mature T cells of donor origin prevents graft-versus-host disease in cyclophosphamide-induced tolerant mice

In cyclophosphamide (CP)-induced tolerance, a long lasting skin allograft tolerance was established in many H-2-identical strain combinations without graft vs host disease. Destruction of donor-reactive T cells of host origin, followed by intrathymic clonal deletion of these cells, has been revealed to be the chief mechanisms of this system. Here, we studied the fate of host-reactive populations in donor-derived T cells of C3H/He (C3H) (H-2k, Mls-1b, Mls-2a) mice rendered CP-induced tolerant to AKR/J (AKR) (H-2k, Mls-1a, Mls-2b), by assessing AKR-derived Thy-1.1+ T cells bearing TCR V beta 3 that are specifically reactive with Mls-2a-encoded Ag of the recipient C3H mice. In the AKR-derived Thy-1.1+ lymph node cells of the C3H mice that had been treated with AKR spleen cells plus CP, CD4(+)-V beta 3+ T cells were obviously decreased by day 10 after the CP treatment. At this stage, the Thy-1.1+ T cells were not detected in the C3H thymus, suggesting that the obvious decrease of CD4(+)-V beta 3+ T cells of AKR origin was not due to intrathymic clonal deletion in the recipient C3H mice. Therefore, the destruction of the host-reactive mature T cells of donor origin, as well as that of the donor-reactive mature T cells of host origin, occurred by the CP treatment at the induction phase. Furthermore, after the establishment of intrathymic mixed chimerism in the recipient C3H mice, V beta 3+ T cells were not detected among the Thy-1.1+ T cells of AKR origin in the mixed chimeric thymus, suggesting that the host-reactive immature T cells repopulated from the injected donor hematopoietic cells were clonally deleted in the recipient thymus. These two mechanisms appear to prevent graft vs host disease in CP-induced tolerance.

Specific destruction of host-reactive mature T cells of donor origin prevents graft-versus-host disease in cyclophosphamide-induced tolerant mice

In cyclophosphamide (CP)-induced tolerance, a long lasting skin allograft tolerance was established in many H-2-identical strain combinations without graft vs host disease. Destruction of donor-reactive T cells of host origin, followed by intrathymic clonal deletion of these cells, has been revealed to be the chief mechanisms of this system. Here, we studied the fate of host-reactive populations in donor-derived T cells of C3H/He (C3H) (H-2k, Mls-1b, Mls-2a) mice rendered CP-induced tolerant to AKR/J (AKR) (H-2k, Mls-1a, Mls-2b), by assessing AKR-derived Thy-1.1+ T cells bearing TCR V beta 3 that are specifically reactive with Mls-2a-encoded Ag of the recipient C3H mice. In the AKR-derived Thy-1.1+ lymph node cells of the C3H mice that had been treated with AKR spleen cells plus CP, CD4(+)-V beta 3+ T cells were obviously decreased by day 10 after the CP treatment. At this stage, the Thy-1.1+ T cells were not detected in the C3H thymus, suggesting that the obvious decrease of CD4(+)-V beta 3+ T cells of AKR origin was not due to intrathymic clonal deletion in the recipient C3H mice. Therefore, the destruction of the host-reactive mature T cells of donor origin, as well as that of the donor-reactive mature T cells of host origin, occurred by the CP treatment at the induction phase. Furthermore, after the establishment of intrathymic mixed chimerism in the recipient C3H mice, V beta 3+ T cells were not detected among the Thy-1.1+ T cells of AKR origin in the mixed chimeric thymus, suggesting that the host-reactive immature T cells repopulated from the injected donor hematopoietic cells were clonally deleted in the recipient thymus. These two mechanisms appear to prevent graft vs host disease in CP-induced tolerance.

[A case of 67-year-old female with multiple giant pulmonary arteriovenous fistula combined with mitral regurgitation]

The patient was a 67-year-old female, complaining of cyanosis, clubbed finger and anoxic spell-like symptom. She was diagnosed as pulmonary arteriovenous fistula combined with mitral regurgitation. The fistula was giant and multiple, and was located in the right middle-lower lobe. Right to left shunt ratio was 27%, SO2 was 58.2%, %VC was 60%, mean pulmonary arterial pressure was 19 mmHg. Mitral regurgitation was mild (II). Ligation of the middle-lower branch of right pulmonary artery and the right lower pulmonary vein was performed through a median sternotomy. All of her symptom improved.

Long term effects of adult-thymectomy on natural killer activity and spontaneous tumor incidence

Long term effects of adult-thymectomy on both natural killer (NK) activity and spontaneous tumor incidence were investigated in C57BL/6 mice maintained in specific pathogen free atmosphere. As compared with the age matched sham-thymectomized mice, a substantially low incidence of spontaneous tumour (6%) and a high level of splenic NK activity were noted one and a half year later in C57BL/6 mice thymectomized at 6 weeks of age. In contrast, sham-thymectomized mice showed a high incidence of the spontaneous tumor (57%) associated with a low level of splenic NK activity. These results suggest that NK cells play a critical role to prevent the occurrence of spontaneous tumor in vivo.

The requirement of intrathymic mixed chimerism and clonal deletion for a long-lasting skin allograft tolerance in cyclophosphamide-induced tolerance

Mechanisms of cyclophosphamide (CY)-induced tolerance were studied. When C3H/He Slc (C3H; H-2k, Mls-1b) mice were primed i.v. with 1 x 10(8) viable spleen cells from H-2-identical AKR/J Sea (AKR; H-2k, Mls-1a) mice and treated with 200 mg/kg of CY 2 days later, a long-lasting skin allograft tolerance to AKR was established. When [C57BL/6 Sea (B6; H-2b, Mls-1b) x AKR]F1 (B6AKF1) cells were used as the tolerogen, however, only a moderate, but not long-lasting, skin tolerance to AKR was observed. In the C3H mice treated with AKR cells and CY, the intrathymic clonal deletion of V beta 6+ T cells, which are strongly correlated with reactivity to Mls-1a antigens, was observed in the chimeric thymus on day 35, although neither the clonal deletion of V beta 6-bearing T cells nor the mixed chimerism was observed in the thymus on day 14. In the C3H mice treated with B6AFKF1 cells followed by CY, however, neither the clonal deletion of V beta 6+ T cells nor the mixed chimerism was observed in the thymus throughout the test period. In the lymph nodes of the C3H mice treated with AKR cells and CY, only CD4+ V beta 6+ T cells, bur not CD8+V beta 6+ T cells, had selectively decreased by day 14, and they were hardly detectable on day 35. The selective decrease of CD4+V beta 6+ T cells in the lymph nodes was also observed by day 14 when B6AKF1 cells were used as the tolerogen, although CD4+V beta 6+ T cells gradually increased on day 35, at which time almost all skin grafts from AKR had already been rejected. These results strongly support the necessity of the intrathymic mixed chimerism and clonal deletion of donor-reactive T cells for a long-lasting skin allograft tolerance in CY-induced tolerance.

Sequential mechanisms of cyclophosphamide-induced skin allograft tolerance including the intrathymic clonal deletion followed by late breakdown of the clonal deletion

The cellular basis of the transplantation tolerance in a model system of BALB/c (Mls-1b) mice rendered cyclophosphamide (CP)-induced tolerant to DBA/2 (Mls-1a) skin allograft was investigated by assessing V beta 6+ T cells. From our results, three major mechanisms that are essential to the CP-induced skin allograft tolerance were sequentially elucidated. The first mechanism was destruction of donor-Ag-stimulated T cells in the periphery by CP treatment. The second mechanism was intrathymic clonal deletion of donor-reactive T cells, such as V beta 6+ T cells, correlating strongly with intrathymic mixed chimerism. The clonal deletion, however, was not always essential for the maintenance of the skin allografts, because DBA/2 skin survived even after the clonal deletion terminated and V beta 6+ T cells reappeared in the periphery of the recipient BALB/c mice. The third mechanism was generation of tolerogen-specific suppressor T cells, especially in the late stage of the tolerance. In contrast, the clonal anergy that is evidenced by the specific suppression of mixed lymphocyte reaction in the recipient BALB/c mice after injecting with DBA/2 spleen cells alone was not considered as a significant mechanism in prolonging skin allograft survival because such anergic mice showed accelerated rejection of the skin allografts. These results may suggest practical hierarchy of the mechanisms of CP-induced allograft tolerance.

Sequential mechanisms of cyclophosphamide-induced skin allograft tolerance including the intrathymic clonal deletion followed by late breakdown of the clonal deletion

The cellular basis of the transplantation tolerance in a model system of BALB/c (Mls-1b) mice rendered cyclophosphamide (CP)-induced tolerant to DBA/2 (Mls-1a) skin allograft was investigated by assessing V beta 6+ T cells. From our results, three major mechanisms that are essential to the CP-induced skin allograft tolerance were sequentially elucidated. The first mechanism was destruction of donor-Ag-stimulated T cells in the periphery by CP treatment. The second mechanism was intrathymic clonal deletion of donor-reactive T cells, such as V beta 6+ T cells, correlating strongly with intrathymic mixed chimerism. The clonal deletion, however, was not always essential for the maintenance of the skin allografts, because DBA/2 skin survived even after the clonal deletion terminated and V beta 6+ T cells reappeared in the periphery of the recipient BALB/c mice. The third mechanism was generation of tolerogen-specific suppressor T cells, especially in the late stage of the tolerance. In contrast, the clonal anergy that is evidenced by the specific suppression of mixed lymphocyte reaction in the recipient BALB/c mice after injecting with DBA/2 spleen cells alone was not considered as a significant mechanism in prolonging skin allograft survival because such anergic mice showed accelerated rejection of the skin allografts. These results may suggest practical hierarchy of the mechanisms of CP-induced allograft tolerance.