[A case report of bentall type operation for annuloaortic ectasia with anomalous origin of the right coronary artery complicated by aortic dissection]

A 49-year-old woman of Marfan's syndrome, who had undergone replacement of the thoracoabdominal aorta for Stanford B type aortic dissection at 47 years of age, developed Stanford A type aortic dissection with annulo-aortic ectasia and aortic regurgitation. At the time of operation, anomalous origin of the right coronary artery from the left sinus of Valsalva and near site of the left coronary orifice were found. Then, composite graft replacement of the ascending aorta and aortic valve, in which a single graft of 16 mm in diameter was interposed between the coronary ostia and composite graft, was performed. Anomalous origin of the right coronary artery from the left sinus of Valsalva is a rare congenital abnormality. It is a matter how to reconstruct the coronary circulation for this type of operation. This technique was useful to reconstruct the aortic root even when an anomalous origin of the coronary artery existed.

Current strategy for severe heart failure with mechanical circulatory support

In the last 10 years, 37 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 12 patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB), and the remaining 4 received a left ventricular assist device (LVAD). Weaning and discharge rates of the patients by type of circulatory supports were 41.7 and 25.0% with VAB, 69.3 and 46.2% with BVB, 87.5 and 37.5% with LVB, 75.0 and 50.0% with LVAD, and 44.4 and 11.1% with PCPS, respectively. Concerning complications of postcardiotomy circulatory support, hemorrhage and ventricular arrhythmia postcardiotomy circulatory support, hemorrhage, and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports (i.e., LVB, LVAD). However, profound biventricular failure, infection, and multiple organ failure remain as possible complications with any type of assisted circulation. These results suggest that early application of circulatory support and appropriate selection of the mode of support and devices used are important for successful circulatory support.

Retrograde cerebral perfusion with hypothermic blood provides efficient protection of the brain: a neuropathological study

Retrograde cerebral perfusion is a method that is recently being used for protection of the brain during operations on the aortic arch. This method is useful but is said to provide a limited time for protecting the brain. We designed an experiment in dogs to investigate neuropathologically the effect of protecting the brain for 120 minutes under: (1) circulatory arrest (CA); (2) retrograde cerebral perfusion with moderately cooled blood (RCPMC); and (3) retrograde cerebral perfusion with deeply cooled blood (RCPDC). We calculated the number of the abnormal cells of 400 hippocampal neurons per dog light microscopically. The number was 199 +/- 23 (mean +/- 1 SD) in the CA group, 149 +/- 50 in the RCPMC group, and 72 +/- 33 in the RCPDC group. The difference between the CA group and the RCPMC group was not statistically significant (p < 0.05), but there was a significant difference between the RCPMC and RCPDC groups (p < 0.05). The degree of cerebral protection provided by retrograde cerebral perfusion for 120 minutes is not sufficient when using moderately cooled blood. If we use deeply cooled blood at a temperature of about 10 degrees C, we should obtain a sufficient degree of protection of the brain.

Extracellular concentration of endogenous free D-serine in the rat brain as revealed by in vivo microdialysis

Using an in vivo microdialysis technique, we have measured the extracellular concentration of endogenous free D-serine in comparison with that of L-serine, glycine and L-glutamate in the discrete brain areas of the freely moving rat. A high concentration of D-serine was observed in the dialysate obtained from the medial prefrontal cortex and striatum, whereas the cerebellar dialysate contained only a trace amount of the D-amino acid. The regional variation in the basal overflow of D-serine was proportional to that of its tissue levels which has been shown to closely correlate with the distribution of the N-methyl-D-aspartate type excitatory amino acid receptor. In contrast, the extracellular release of glycine and L-glutamate was higher in the cerebellum and very low in the striatum. The extracellular concentrations of L-serine were more than three times those of striatal D-serine in the three regions. Neither addition of a sodium channel blocker, tetrodotoxin (2 microM), nor deprivation of Ca2+ from the perfusate reduced the basal extracellular levels of the four amino acids tested in the medial prefrontal cortex. Furthermore, intra-frontal cortex perfusion of a sodium channel activator, veratrine (200 micrograms/ml), caused an increase in the extracellular release of glycine and L-glutamate but a slight decrease in that of D-serine in a tetrodotoxin-sensitive manner in the cortical region.(ABSTRACT TRUNCATED AT 250 WORDS)

[The validity and reliability of a Japanese version of Arthritis Impact Measurement Scales in patients with rheumatoid arthritis]

A Japanese version of Arthritis Impact Measurement Scales (Japanese-AIMS) was developed after the original AIMS Version 2 (AIMS 2). We then conducted a Quality of Life measurement of 691 patients with Rheumatoid Arthritis (RA) with this newly developed questionnaire. Based on the data collected, the validity and reliability of the Japanese-AIMS was examined. The validity of the Japanese-AIMS, which was assessed by the examination of internal consistency among items and through factor analysis, was almost comparable with that of the original AIMS 2. QOL scales were also validated using internal standards based on the subject's responses to other items in the questionnaire. The test-retest reliability, which was the correlation of scale scores between two tests administered 4-5 weeks apart, was slightly lower than the original one. We conclude that the validity and reliability of the Japanese AIMS were comparable with those of the original one, though there could be possibly improved by the minor revision of phrasing. The large scale QOL measurement study with RA patients is under way, using the Japanese-AIMS with minor revision.

[A rapid susceptibility test of Mycobacterium tuberculosis using hybridization protection assay]

The conventional drug susceptibility tests of Mycobacterium tuberculosis are time-consuming and usually require 2 to 4 weeks to obtain final results. In this study, we attempted to develop a novel method for rapid detection of drug-resistant M. tuberculosis using hybridization protection assay (HPA). Clinically isolated strains of M. tuberculosis including seven isoniazid (INH) susceptible strains and six resistant strains were used. The organisms grown on Ogawa egg medium were inoculated into Middlebrook 7H9 broth and cultured at 37 degrees C for one week. Then, the inoculum of each strain was prepared as a tenfold dilution of bacterial suspension at McFarland No. 0.5. The inocula were mixed with INH solutions to yield final concentrations of 0.1 and 1.0 micrograms/ml, and the resulting bacterial suspensions with or without test drug were cultured on the swaying plate at 37 degrees C for up to 5 days. At intervals, 50 microliters of each sample was withdrawn and subjected to the protocol of the HPA using acridinium-ester (AE) labeled DNA probe, and then the relative light unit (RLU) was read in a luminometer. In the case of the susceptible strains, a significant difference in the mode of increase in RLU ratio (% of RLU on day x/RLU on day 0) was observed between the INH-treated and drug-free control sets within three days of cultivation, while no such differences were seen in the case of the resistant strains.(ABSTRACT TRUNCATED AT 250 WORDS)

[Successful mitral valve plasty for mitral regurgitation combined with dilated cardiomyopathy in Noonan's syndrome]

We have experienced a mitral valve plasty for mitral regurgitation combined with dilated cardiomyopathy in a 21-year-old male patient with Noonan's syndrome, who had suffered from recurrent congestive heart failure. In echocardiography, severe mitral regurgitation and prolapse of the posterior mitral leaflet were noted. The left ventricle was dilated and the function was severely deteriorated. The plasty consisted of plication of the prolapsed posterior leaflet and annuloplasty with Carpentier ring. Intraoperative biopsy of the myocardium of the left ventricle showed an appearance consisting with dilated cardiomyopathy. Postoperatively the mitral regurgitation disappeared and the patient returned to his ordinary life.

Free D-serine in post-mortem brains and spinal cords of individuals with and without neuropsychiatric diseases

We have measured the concentrations of free D-serine post-mortem in the prefrontal cortex, parietal cortex, cerebellum and spinal cord from individuals with and without (controls) neuropsychiatric diseases using high-performance liquid chromatography with fluorometric detection. The levels of D-serine were found to be high in the prefrontal and parietal cortex (around 100 nmol/g wet weight) and very low in the cerebellum and spinal cord (below 10 nmol/g wet weight). The uneven distribution of the D-amino acid in the human central nervous system (CNS) resembles that observed in rodents, suggesting that, as shown in the rat CNS, the regional variation of D-serine content in the human brain might also be closely correlated with those of the N-methyl-D-aspartate (NMDA) type excitatory amino acid receptor. In the prefrontal cortex, the gray and white matter had a similar concentration of D-serine. These findings, together with the selective action of D-serine at the NMDA-related glycine site and the non-neurogenic nature of extracellular D-serine release, add further support to the view that D-serine could be an intrinsic modulator of the NMDA receptor liberated from certain glial cells in the mammalian brain. Despite the anti-psychotogen activity of D-serine in the rat, there were no statistically significant differences between the D-serine contents in the prefrontal or parietal cortex of controls and those of patients with schizophrenia or dementia of the Alzheimer type.

Different functional recovery of the left ventricle after valve replacement for aortic regurgitation: correlation between grade of ventricular arrhythmia and long-term mortality

Although aortic valve replacement for aortic regurgitation relieves left ventricular volume overload, ventricular size often remains abnormal after operation, particularly in the setting of marked or prolonged preoperative left ventricular dysfunction. The aim of this study is to assess the relationship between the grade of ventricular arrhythmias before operation and the recovery of left ventricular function after aortic valve replacement. Between January 1980 and August 1993, 229 patients with pure aortic regurgitation underwent aortic valve replacement at our institution. In this group, 50 patients (21.8%) who showed left ventricular end-systolic volume index (LVESVI) of 150 ml/m2 or greater received 24-hour ambulatory electrocardiographic recordings before and after operation. According to the preoperative grade of ventricular arrhythmias, the patients were divided into three groups. Group A included 20 patients with severe and frequent ventricular premature beats (VPBs). Group B included nine patients with severe and non-frequent ventricular premature beats (VPBs). Group C included 21 patients with non-severe and non-frequent VPBs. Left ventricular end-systolic dimension (LVDs), end-diastolic dimension (LVDd) and fractional shortening (LVFS) were measured in each echocardiogram before, and one year and five years after operation. LVDd significantly decreased at one year after operation in all three groups. At one year after operation, LVDs significantly decreased in group B (42.0 +/- 7.6 mm) and group C (42.6 +/- 8.6 mm), while LVDs showed no significant change in Group A (55.4 +/- 11.1 mm). After five postoperative years, further significant decrease of LVDs was found in group C (32.4 +/- 7.1 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

[Change in the treatment procedures for mitral valve disease]

This study investigated the changes in treatment procedures for mitral stenosis (MS) and mitral regurgitation (MR) against the background of a decrease in the incidence of rheumatic valvular disease. The study included 3,955 patients with MS undergoing closed mitral commissurotomy (CMC), open mitral commissurotomy (OMC), mitral valve replacement (MVR), or percutaneous transvenous mitral commissurotomy (PTMC) between 1952 and 1991, and 478 patients with MR undergoing MVR or mitral valvuloplasty in the Heart Institute of Japan, Tokyo Women's Medical College. The number of patients with MS undergoing surgical or catheter interventions has decreased and is now about 80 per year, a half of that experienced in the 1960s. CMC and OMC have been replaced by PTMC since the 1990s. The most popular treatment procedure is now MVR. The number of patients with MR undergoing surgery has increased to about 30 per year. Eighty percent of operations for MR are MVR and the others are mitral valvoplasty. Survey of the etiology of MR shows decreased rheumatic disease and increased degenerative disease. The incidence of MR due to ischemic heart disease and hypertrophic obstructive cardiomyopathy has slightly increased.

Operation for type B aortic dissection: introduction of left heart bypass

Various support techniques for surgical treatment of type B aortic dissection have been used and recommended in many medical centers. In the last 21 years, 55 patients with type B aortic dissection underwent 65 operations including 10 reoperations, and 10 cases showed Marfan's syndrome. As circulatory support during operation, venoarterial bypass mainly was used until March 1987 (period I) and low-dose heparinized left heart bypass was applied since April 1987 (period II). Surgical results were compared among subgroups by the Kaplan-Meier actuarial method and Cox-Mantel statistical analysis. After the operation, early mortality was 27.3% in 33 patients in period I and 9.4% in 32 patients in period II (p = 0.06). The incidence of fatal hemorrhagic complications was decreased significantly by using the left heart bypass technique (p < 0.02). The 5-year actuarial survival of type B dissection was 60.6% in period I and 79.2% in period II (p = 0.07). These results suggest that surgical results of type B aortic dissection in this series might be improved with the introduction of left heart bypass and extended surgical procedures.

Operation for type A aortic dissection: introduction of retrograde cerebral perfusion

Circulatory support during operation for type A aortic dissection is controversial among many medical centers. In the last 21 years, 100 patients with type A aortic dissection underwent 102 operations including 2 reoperations, and 29 patients showed Marfan's syndrome. During operation, no cerebral perfusion technique was used through February 1985 (period I), antegrade cerebral perfusion was applied since March 1985 (period II), and retrograde cerebral perfusion was introduced in November 1990 (period III). Surgical results were compared among these subgroups. Operative mortality was 12.1% in 33 chronic and 57.1% in 7 acute patients in period I, 11.1% in 27 chronic and 54.5% in 11 acute patients in period II, and 6.7% in 15 chronic and 0% in 9 acute patients in period III (period II versus III; p = 0.04). Retrograde cerebral perfusion decreased permanent brain complications. The 5-year actuarial survival was 59.7% in period I and 63.2% in period II (not significant), and the 3-year survival of period III was 91.7%. Actuarial survival of period III was significantly higher than those of periods I and II (p < 0.05). Surgical repair of aortic arch with cerebral perfusion techniques reduced the residual aneurysms. These results show that surgical results of type A aortic dissection in this series improved with the introduction of retrograde cerebral perfusion and extended surgical procedures.

[Geometrical study on intra-arterial aortoinfundibuloplasty]

Newly-developed procedure for aortic annular enlargement was geometrically examined on its optimal annular augmentation. Valve prosthesis is accommodated by anterior annular split extending into aortopulmonary and infundibular septum and, eventually, protrudes into pulmonary valvular orifice in this procedure. Relationship between residual pulmonary valvular area (PVA) and aortic annular incremental radius (x) is given by: PVA = (r+x)2 [pi - 2 pi x/(r+x) + sin (2 pi x/(r+x))], where r is original aortic annular radius. Optimal aortic annular augmentation maximizing PVA and saving original PVA is 1.33 times and 1.70 times of original diameter respectively. Animal experiments employing six mongrel dogs demonstrated no significant increase of systolic peak pressure gradient in right ventricular outflow tract after the procedure standardized by this geometrical idea. Our procedure would bear radical enlargement of small aortic annulus.

[Clinical significance of transesophageal echocardiography for evaluation of patients after Bentall's operation: detection of graft failure]

Leakage from the composite graft at the site of coronary anastomosis into the perigraftal space (pseudoaneurysm) is an important complication of Bentall's operation. The clinical value of transesophageal echocardiography (TEE) for detecting this graft failure was evaluated in 30 patients who underwent Bentall's operation or Piehler's modification. Three patients (10%) had perigraftal leakage (pseudoaneurysm). TEE demonstrated the leakage site which was not clearly showed by computed tomography (CT) scan and aortography. The detection rate of the anastomosed native coronary artery was 89% (left: 100%, right: 67%). Interposition graft by Pichler's modification method was detected in 96% (left: 100%, right: 92%) of cases by TEE, but only in 43% (left: 57%, right: 29%) by CT scan (left: p < 0.005, right: p < 0.0001). The detection rate of the right coronary artery, interposition graft to right coronary artery, and their color signals were lower than those of the left coronary artery. TEE has considerable diagnostic value in evaluating patients after Bentall's operation.

[Relation between preoperative ventricular arrhythmias and postoperative results in aortic valve regurgitation]

Sudden death is a well known complication of aortic valve regurgitation and remains a common cause of late mortality after aortic valve replacement. Although malignant arrhythmias have been suggested as the cause of these outcome, there has been little information concerning the frequency and severity of ventricular arrhythmias in patients with aortic valve regurgitation. In order to evaluate the relation between the severity and/or frequency of ventricular arrhythmias and late postoperative results in patients with pure aortic valve regurgitation, 24-hour ambulatory electrocardiographic recordings were obtained before surgery in 107 patients without coronary artery disease. Grading of ventricular arrhythmias was based on a Lown method and compared with hemodynamic data. Ventricular premature beats were observed in 101 patients (94.4%) before operation. Multiformity was found in 10 patients (9.3%) couplets in 19 patients (17.8%) and ventricular tachycardia in 32 patients (29.9%). Patients with severe ventricular arrhythmias (Lown grade 3 or 4: 57.0%) had a higher left ventricular end systolic volume index (LVESVI) 153.1 +/- 76.4 ml/m2 vs 96.5 +/- 35.0 ml/m2 (p = 0.0001); a higher left ventricular end diastolic volume index (LVEDVI) 257.0 +/- 85.4 ml/m2 vs 206.5 +/- 58.3 ml/m2 (p = 0.0009); a lower left ventricular ejection fraction (LVEF) 43.4 +/- 12.5% vs 54.2 +/- 9.8% (p = 0.0001). LVESVI was not related to the severity of ventricular arrhythmias, but was significantly related to the frequency (p < 0.05). All patients with late death were belonging to Lown grade 3 or 4 in severity and more than 30 beats per hour in frequency (28.6%). This study indicates that ventricular arrhythmias are common in patients with aortic valve regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Surgical treatment of aortico-left ventricular communication due to infective endocarditis]

A 51-year-old woman was referred to our institute for surgical treatment from an other hospital where she was diagnosed as having a mycotic aneurysm located at the aortic annulus due to infective endocarditis. The aneurysm communicated with the left ventricle, with aortic stenosis and regurgitation, mitral stenosis and tricuspid regurgitation caused by rheumatic fever. On admission to our institute, the infective endocarditis was at the healed stage. The mycotic aneurysm was located at the aortic annulus of the right coronary cusp, and was closed using a prosthetic patch with mattress sutures. Aortic valve replacement with a 19-mm St. Jude Medical prosthesis was then performed on this patch. The mitral and tricuspid valves were also replaced with 27-mm and 29-mm St. Jude Medical prostheses, respectively. The patient is doing well 1 year after surgery.

[Experimental study on organ perfusion by intraaortic balloon counterpulsation with double balloon catheter]

Newly-developed catheter for the intraaortic balloon counterpulsation with cardio-renal assist was examined on animal model. The catheter consists of two balloon segments between which the celiac trunk, the superior mesenteric artery and the renal artery are to be placed. Statistical comparison on each hemodynamic element was carried out between the catheter (DBC), conventional single balloon catheter (SBC) of the same balloon volume as DBC and no assist (None) groups. There were no significant changes between SBC and DBC in cardiac output, femoral arterial flow and central venous pressure. Renal arterial flow and urinary output were significantly increased in DBC (None 14.4 +/- 3.9, SBC 22.6 +/- 5.6, DBC 31.0 +/- 6.9 ml/min in renal arterial flow, None 33 +/- 9, SBC 64 +/- 14, DBC 78 +/- 20 ml/h in urinary output, p < or = 0.05). After the remodeling adjust to the human stature, a clinical application would be considered.

Current strategy of circulatory support for profound heart failure

The purpose of this study is to assess the current strategy of mechanical circulatory support for profound heart failure. In the last 10 years, 37 patients with profound heart failure underwent mechanical circulatory support after open heart surgery and 9 patients with non-cardiotomy cardiogenic shock received emergency circulatory support. All patients showed severe cardiac failure and/or fatal ventricular arrhythmia and required circulatory support as a life-saving measure. After cardiovascular surgery, 12 of those patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB) and the remaining 4 patients received left ventricular assist device (LVAD). And 9 patients with non-cardiotomy cardiogenic shock received percutaneous cardiopulmonary support (or PCPS) as an emergency assist system. Weaning and discharge rates of the patients by the type of circulatory supports were 41.7% and 25.0% with VAB, 69.3% and 46.2% with BVB, 87.5% and 37.5% with LVB, 75.0% and 50.0% with LVAD, and 44.4% and 11.1% with PCPS, respectively. Clinical results of post-cardiotomy circulatory support (64.9% of weaning and 37.8% of discharge) were acceptable, but the patients with non-cardiotomy cardiac failure needed early application of more advanced circulatory support.

Detection of (1-3)-beta-D-glucan in a rat model of aspergillosis

The G test containing factor G, fractioned from the Limulus lysate, was used to detect (1-3)-beta-D-glucan in a rat model of aspergillosis. Aspergillus fumigatus strain MF-13, 1 x 10(4) conidia, were inoculated transtracheally into rats treated with cortisone acetate (100 mg/kg) and fed a low-protein (8%) diet. Increased serum (1-3)-beta-D-glucan was found on the sixth day after inoculation in concentrations of 370 +/- 178 pg/ml (mean +/- SD) in untreated controls, and 154 +/- 43 pg/ml in rats treated with 0.5 mg/kg of amphotericin B. On day 11 (1-3)-beta-D-glucan concentrations were 2,590 +/- 2,940 pg/ml and 448 +/- 442 pg/ml, respectively. The elevation in levels of (1-3)-beta-D-glucan increased in correlation with the elevation of galactomannan antigen titers; (1-3)-beta-D-glucan is thus measurable during experimental aspergillosis in rats.

Medium-term results after surgery for aortic arch aneurysm with hypothermic cerebral perfusion

We have used two techniques of hypothermic cerebral perfusion (CP) for the surgical treatment of aortic arch aneurysm in the last 10 years. Between March 1985 and December 1993, 83 patients underwent surgery for aortic arch aneurysm. Fifty-one cases had aortic dissection (AD) in the transverse arch and/or its branches, and 32 cases showed true aneurysm (TA) of the aortic arch. In those 83 patients, 37 cases received antegrade CP and 46 cases underwent retrograde CP. Surgical results were compared among the groups by Kaplan-Meier actuarial method and Cox-Mantel statistical analysis. The early mortality after surgery for aortic arch aneurysm was 11.8% in the AD group and 21.9% in the TA group. The early mortality was 21.6% with antegrade CP and 10.9% with retrograde CP. The 6-year actuarial survival rate was 71.7% in the TA group and 67.1% in the AD group. In the AD group, the 3-year survival rate was 93.9% with retrograde CP and 61.1% with antegrade CP (P < 0.005). In the TA group, the 3-year survival rate was similar for antegrade CP (73.3%) and retrograde CP (69.2%). These results suggest that current surgical results of aortic arch aneurysm with hypothermic CP are acceptable and the retrograde CP technique might be recommended, especially for surgery of aortic arch aneurysm with AD.

[Surgical treatment of false aneurysms following Bentall's operation]

Between January 1973 and June 1993, 157 patients had Bentall's operation and its modifications for the surgical treatment of annuloaortic ectasia and dissecting aneurysm in our institute. Reoperation for false aneurysms following Bentall technique were performed 10 patients. There were 8 males and 2 females. This ages ranged from 29 to 57 years with an average of 41. The interval between initial and subsequent operation was from 3.7 to 18.4 years (median, 8.2 years). Prior to a median sternotomy, femoro vein-femoral artery partial cardiopulmonary bypass was instituted occationaly. Operative technique of repair of coronary detachment were direct closure in 6 and interposition graft technique in 4 patients. There were 2 hospital death caused by rupture at median aternotomy and graft infection. The actuarial freedom from reoperation at 10 years according to technique of coronary reattachment, for the patients with one lane suture was 69%, for those with two lane suture was 95% (p < 0.01), and for those with interposition graft technique was 100%. In conclusions, it was very important for repair of false aneurysms following Bentall procedure to expose aneurysms safely through proper approach. Interposition graft technique was preferable to repair coronary detachment. Our recent surgical results of Bentall procedure improved by the modification of the coronary reimplantation method.

[Rapid identification of mycobacteria by combined method of polymerase chain reaction and the gen-probe DNA hybridization system]

We developed the rapid detection and identification method of mycobacteria, involving amplification of mycobacterial 16S rRNA gene by nested PCR and identification of M. tuberculosis complex or M. avium-intracellulare complex (MAC) by hybridization protection assay (HPA) using the acridinium-ester (AE) labeled DNA probe. The specificity of the nested PCR combined with DNA probe test was excellent in terms of detection of mycobacterial organisms and identification of M. tuberculosis or MAC. The detection limits of the present method were 10 fg DNA for M. tuberculosis, and 100 fg DNA for MAC, respectively. We further investigated on the optimum temperature for hybridization in HPA with AE labeled DNA probe because there was the difference in the mode of DNA-RNA hybridization from that of DNA-DNA hybridization. In our method, the optimum temperature of hybridization was estimated as 55 +/- 1 degrees C. In preliminary experiments on two clinical cases, we practically detected and identified M. tuberculosis and MAC in clinical specimens, such as sputa, by using this newly devised method. We concluded that this method is useful for rapid detection and identification of M. tuberculosis and MAC in clinical specimens.

Isolated dissecting aneurysm of the common iliac artery: report of a case

Isolated dissecting aneurysms of the peripheral arteries which are not accompanied by a dissecting aneurysm of the aorta are rarely observed. We report herein the unusual case of a 54-year-old man in whom an isolated common iliac aneurysm was found to be caused by isolated dissecting aneurysms of the left common iliac artery.

Tricuspid valve replacement with the bileaflet St. Jude Medical valve prosthesis

Case histories of 39 patients who underwent tricuspid valve replacement with the St. Jude Medical prosthesis between June 1979 and August 1992 were reviewed in March 1993. The average patient age at the time of the operation was 46 +/- 11 years (range from 17 to 68 years). Concomitant mitral and/or aortic valve replacements were performed in 30 patients. All patients were given warfarin to maintain thrombotest between 10% to 25%. This number was between 2.8 to 1.6 times the control value in the International Normalized Ratio of prothrombin time. Three operative deaths occurred (7.7%). Among six late deaths, two patients died suddenly of unknown causes, and the remaining patient deaths were not valve-related. The actuarial survival rate at 14 years was 54.7%. Valve thrombosis occurred in one patient and was successfully treated with intravenous urokinase. This was the only valve-related complication (0.67%/patient-year). No reoperations were necessary in the tricuspid position. In conclusion, the St. Jude Medical valve is our choice of prosthesis for tricuspid valve replacement in adult patients who can receive proper anticoagulation therapy.