Effect of posture on bronchial reactivity to inhaled methacholine in patients with mitral valve stenosis

To compare the effects of posture on bronchial reactivity in 12 patients with mitral valve stenosis (MS) and 10 with bronchial asthma (BA), a methacholine inhalation test was performed 2 h after being in either a supine or sitting position. All patients showed bronchial hyperreactivity to inhaled methacholine before the study. In MS patients, logarithmic values of the cumulative dose producing a 35 percent decrease in respiratory conductance (log PD35Grs) were significantly lower 2 h after being in a supine position than in those after being in a sitting position (0.71 +/- 0.78, 1.02 +/- 0.53 log units, respectively, p < 0.05). In BA patients, however, log PD35Grs did not show significant changes (0.42 +/- 0.51, 0.58 +/- 0.48 log units, respectively). Variables of pulmonary function tests showed no significant differences between the two positions in both patients with MS and BA. We conclude that the bronchial hyperreactivity in MS is enhanced after the supine position for 2 h and that the supine posture may play an important role in the pathogenesis of cardiac asthma.

[A case of pulmonary tuberculosis developed immediately after a chest wall injury]

A 75-year-old female was admitted to our hospital for further examination of the cause of blood-stained sputum and abnormal shadow on chest radiogram which had developed immediately after an injury of right chest wall. The bacteriological examination of sputum on admission revealed negative Gaffky score, but positive PCR, and Mycobacterium tuberculosis was isolated by culture. Her symptoms and chest radiogram were improved by the administration of isoniazid, ethambutol and rifampicin. Although development of pulmonary tuberculosis induced by chest wall injury is rare, in case of the aged persons such possibility should be considered. PCR may be useful for rapid diagnosis of tuberculosis, even in such case.

[Transcranial Doppler measurement of middle cerebral artery blood flow during continuous retrograde cerebral perfusion]

This is the first report of cerebral blood flow measurement with transcranial Doppler (TCD) during aortic arch reconstruction using continuous retrograde cerebral perfusion (CRCP) with deep hypothermia. Cerebral blood flow velocity was measured in 6 patients. CRCP was performed via the superior vena cava (SVC) at 30 cmH2O of internal juglar vein pressure and at 18 degrees C or lower of minimum bladder temperature. During the operation, the flow velocity of the middle cerebral artery (MCA) was continuously measured with TCD fixed on the temple. The cerebral blood flow during CRCP was different in each of the 6 patient. The retrograde MCA flow could be measured during CRCP in 3 patients, and the flow velocity was 11-60% of the MCA flow velocity before cardiopulmonary bypass. In the other 3 patients, retrograde MCA flow could not be detected during CRCP, but antegrade MCA flow could be found after antegrade perfusion was resumed. The antegrade flow velocity right after CRCP became more than the MCA flow before CRCP, which was regarded as a reaction due to cerebral ischemia. All the patients awoke within several (2-9) hours after operations and had no permanent neurological complications. But 2 patients developed drowsiness for several days after the operations; their CRCP times were 127 and 131 minutes. It is concluded that CRCP is a simple technique for brain protection, but the cerebral blood flow during CRCP is a simple technique for brain protection, but the cerebral blood flow during CRCP is different in each patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunogenicity of the C-terminal 19-kDa fragment of the Plasmodium falciparum merozoite surface protein 1 (MSP1), YMSP1(19) expressed in S. cerevisiae

The immunogenicity of the C-terminal 19-kDa fragment of Plasmodium falciparum MSP1 expressed in yeast as a nonfusion product, YMSP1(19), was studied. Immunization with YMSP1(19) in rabbits induced high titers of Abs specific for native conformational epitopes on parasite MSP1. In mice, immunogenicity was dependent on the mouse strain and the adjuvant formulation. This suggests that different adjuvants may alter the immunogenicity of MSP1(19) in a genetically diverse population. Although YMSP1(19) induced anti-MSP1 Abs, they did not inhibit in vitro parasite growth. This contrasts with the strong inhibitory activities of Abs produced against a recombinant MSP1(42) (BVp42), which contains the entire MSP1(19) coding sequence. Further analyses showed that YMSP1(19) was the target of the inhibitory, anti-BVp42 Abs because YMSP1(19) could completely block binding of anti-BVp42 Abs to parasite MSP1 or BVp42. Moreover, depletion of YMSP1(19)-specific Abs completely abolished the parasite inhibitory activities of anti-BVp42 sera. Anti-YMSP1(19) sera did not block the inhibitory activities of anti-BVp42 sera, suggesting that inhibitory epitopes were not in close structural proximity with noninhibitory epitopes. The finding that YMSP1(19) possessed inhibitory epitopes but induced anti-MSP1 Abs that were not inhibitory suggests that although the T-epitope(s) produced by immunization with YMSP1(19) could provide help for Ab production, it did not induce an effective inhibitory Ab response. We hypothesize that the nature/specificity of T helper epitopes on MSP1 may be crucial in efficient induction of biologically relevant and/or protective Abs.

Immunogenicity of the C-terminal 19-kDa fragment of the Plasmodium falciparum merozoite surface protein 1 (MSP1), YMSP1(19) expressed in S. cerevisiae

The immunogenicity of the C-terminal 19-kDa fragment of Plasmodium falciparum MSP1 expressed in yeast as a nonfusion product, YMSP1(19), was studied. Immunization with YMSP1(19) in rabbits induced high titers of Abs specific for native conformational epitopes on parasite MSP1. In mice, immunogenicity was dependent on the mouse strain and the adjuvant formulation. This suggests that different adjuvants may alter the immunogenicity of MSP1(19) in a genetically diverse population. Although YMSP1(19) induced anti-MSP1 Abs, they did not inhibit in vitro parasite growth. This contrasts with the strong inhibitory activities of Abs produced against a recombinant MSP1(42) (BVp42), which contains the entire MSP1(19) coding sequence. Further analyses showed that YMSP1(19) was the target of the inhibitory, anti-BVp42 Abs because YMSP1(19) could completely block binding of anti-BVp42 Abs to parasite MSP1 or BVp42. Moreover, depletion of YMSP1(19)-specific Abs completely abolished the parasite inhibitory activities of anti-BVp42 sera. Anti-YMSP1(19) sera did not block the inhibitory activities of anti-BVp42 sera, suggesting that inhibitory epitopes were not in close structural proximity with noninhibitory epitopes. The finding that YMSP1(19) possessed inhibitory epitopes but induced anti-MSP1 Abs that were not inhibitory suggests that although the T-epitope(s) produced by immunization with YMSP1(19) could provide help for Ab production, it did not induce an effective inhibitory Ab response. We hypothesize that the nature/specificity of T helper epitopes on MSP1 may be crucial in efficient induction of biologically relevant and/or protective Abs.

[Relation between surgical outcome and preoperative end-systolic volume of the left ventricle in patients with regurgitant valvular heart disease]

The relation between the end-systolic volume index of the left ventricle (ESVI (ml/m2)) and the early and late results after valve replacement were reviewed in 249 patients with pure aortic regurgitation (AR) and 189 patients with pure mitral regurgitation (MR). The patients with AR were classified into 4 groups (A1-A4) and those with MR were classified into 3 groups (M1-M3) according to the ESVI. The ESVI, the number of patients (No of P), early mortality rate (EM) and the actuarial survival rate at 12 years after valve replacement (AS at 12 yr) in each group are shown in the following Table. [table: see text] The actuarial survival rate at 12 years after operation in A1 and A2 were significantly lower than that in A3 and A4. In 57% of the late deaths in A1 and A2 patients, the cause of the death was thought to be rhythm disturbance. In contrast, there were no differences in late survival among the three groups with MR (M1, M2 and M3). The minor axis of the left ventricle at end-diastole and at end-systole (Dd and Ds) and shortening fraction of the left minor axis (FS), evaluated by echocardiography, were normalized early after the operation in A1 patients only. The Dd, Ds and FS in A2 and A3 returned to normal late after the operation. However, in A4, these parameters still remained abnormal. Thus, patients with a deteriorated left ventricle can survive the operation. However, the long-term results in patients with AR with ESVI more than 150 ml/m2 were unsatisfactory.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of deep saturation diving on the lymphocyte subsets of healthy divers

We examined the effect of deep saturation diving on the host defense mechanisms of five healthy volunteers using fluorescein-dye-conjugated monoclonal antibodies. Six divers engaged in a 440-m saturation diving simulation with total hyperbaric exposure of 30 days; five served as subjects. Change in the expression of surface molecules on the lymphocytes was analyzed during that period. Blood samples were serially taken on Days 4, 6, 8, 15, 22, 29, and after surfacing. The total number of lymphocytes showed no remarkable change. However, the fraction of T (CD3+) cells decreased from 68.0 +/- 3.3% to 55.8 +/- 5.8% (Day 8), and B cells increased reciprocally. In these T cells, the CD4:CD8 ratio (normally > 1.0) became less than 1.0 during compression and thereafter. In spite of the prophylactic use of anti-external otitis agents, one of the divers revealed a remarkable growth of Pseudomonas in the external auditory meatus, showing a high level of blood endotoxin (10.2 pg/ml). These results suggest that decrease in CD4+ fraction of T lymphocytes might explain in part the decreased resistance of divers to infective microorganisms in deep saturation diving.

Investigation of "signal" constituents for the evaluation of animal crude drugs. I. Free amino acids and total amino acids

The contents of free amino acids (FAA) and total amino acids (TAA; including peptide and protein forms) in 10 animal drugs were determined using precolumn-derivatization high performance liquid chromatography (HPLC). The results showed that the FAA and TAA content was characteristic for a particular animal crude drug. For example, Bezoar Bovis contained much more taurine relative to the FAA and TAA content compared with other crude drugs, and kokurozin contained much more TAA and much less secondary amino acids relative to TAA compared with koukuzin. FAA and TAA were proved to be "signal" constituents for the evaluation of animal crude drugs.

Electrochemical method for estimating the antioxidative effects of methanol extracts of crude drugs

The antioxidative effects of methanol extracts of crude drugs were estimated by an electrochemical method because there are many electrochemically-active substances in natural antioxidants. Twelve kinds of crude drugs, which had been reported to exhibit strong activity in an antioxidative test based on the air oxidation of linoleic acid, were studied. The oxidative capacity calculated from voltammograms of their methanol extracts were compared and examined together with data on their radical scavenging effects. The results showed that the electrochemical behavior in most cases correlated with the radical scavenging effect. Crude drugs which had clear oxidative peaks below +1.2 V and a large oxidative capacity were suggested to have strong radical scavenging effects. It was clear that substances oxidized at lower potentials had stronger radical scavenging effects than those oxidized at higher potentials. Therefore, this electrochemical method can be considered as a rapid and simple method for estimating the antioxidative effects as a radical scavenger.

[Reoperations on valvular disease: an analysis of outcome]

To evaluate risks and complications of reoperation on valvular disease, we reviewed data on 186 patients who underwent reoperations because of prosthetic valve malfunctions, pregression of valvular disease after open mitral commissulotomy and previous valvular replacement. Overall hospital mortality was 4.8% (9/186 patients). The common causes of death was low cardiac output syndrome (3 pts.) and respiratory failure (3 pts.) and others (3 pts). Hospital mortality was different according to the risk factors. There was no significant difference between the operative procedures; AVR (6.2%), MVR (3.2%), DVR (8%), TVR (0%) and MVR + TVR (9%). Furthermore, advanced age, valve position, renal failure, preoperative %FS, LVDd and diagnosis of prosthetic valve malfunction did not appear to be significant risk factor. However, preoperative respiratory failure and emergency operation showed significant increase of hospital mortality in comparison with other factors. On the basis of this reports, hospital mortality and late survival indicated that reoperation should be performed early as the potentially safe condition.

An internal thoracic artery homograft as a new small caliber vascular substitute

The authors have examined the possibility of usage of an internal thoracic artery (ITA) homograft as a new small caliber vascular substitute. Left subclavian artery to left atrial appendage shunts with fresh ITA homografts (n = 6) or ITA autografts (n = 5) were made by modified techniques of coronary artery bypass grafting in mongrel dogs (body weight, 11-16.5 kg). All recipient dogs had no anticoagulant therapy or immunosuppression. Inner diameter of the grafts was between 1.4 and 2.0 mm. Blood flow in ITA grafts was measured by electromagnetic flow meter. The graft flow was 6-14 ml/min before harvest and 67-220 ml/min just after implantation, and there was no significant difference between groups. Flow in the ITA homografts decreased significantly compared with ITA autografts 1 month after operation, but five of six ITA homografts were patent. Histopathology of the grafts showed vascular rejection in the homograft group. These results suggest that an ITA homograft with postoperative immunosuppression might be a new small caliber vascular substitute for coronary artery bypass grafting in ischemic heart disease and the systemic-pulmonary shunt operation in congenital heart diseases.

[Surgical treatment of infective endocarditis in patients with congenital heart disease]

From 1981 to March 1993, 21 patients underwent surgical treatment for infective endocarditis (IE) associated with congenital heart disease (CHD). We evaluated the surgical results with regard to various factors, including microorganisms, pre- and postoperative complications, the correlation between CHD and the infective focus in the valve, the operative methods and surgical results. Underlying CHD included ventricular septal defect (VSD) in 15 (71.5%), persistent ductus arteriosus (PDA) in 2 (9.5%), tetralogy of Fallot (TF) in 2 (9.5%) and incomplete endocardial cushion defect (IECD) in 2 patients (9.5%). Microorganisms were detected in 71.4% of the patients, including streptococcus in 11 patients (52.4%), staphylococcus in 2 (9.5%) and gram-negative bacillin in 2 (9.5%). Embolism or infarction was noted preoperatively in 5 patients (23.8%) and was located in the kidney in 4 patients, the leg in 2, and in the liver and lung in 1 patient each. Among 15 patients with VSD, the lesion of IE was seen on the left side of the heart in 11 patients, on the right side in 3 and on both sides in 1. The PDA and IECD were seen on the left side in 2 patients each, but the IE focus of the 2 patients with TF was on the left side in one and on both sides in the other patient. Aortic valve replacement was performed in 17 patients, mitral valve replacement in 3, tricuspid valve plasty in 2, tricuspid annuloplasty in 1 and pulmonary valve resection in 2 patients. The operative mortality was 4.8% and there were no reoperations or late deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

[Long-term results after cardiac valve replacement: 16 years follow-up of 190 patients]

According to STS/AATS guidelines 1988, we compared the long-term results after cardiac valve replacement (ReAVR 26, ReMVR 127, ReDVR 35, ReTVR 2, total 190 patients) with those after initial valve replacement (AVR 760, MVR 1, 001, DVR 431, TVR 22, total 2,214 patients). Actuarial survival (AS), reoperation free (RF) and freedom from all valve-related events (EF) at the 10th postoperative year were 74.6%, 100%, 70.1% after ReAVR, 84.2%. 97.8%, 75.8% after AVR, 82.9%, 91.4%, 75.8% after ReMVR, 86.5%, 91.7%, 70.7% after MVR. 78.4%, 92.9%, 63.2% after ReDVR, 82.8%, 95.6%, 73.8% after DVR, respectively. There was no significant difference of AS, RF and EF between ReVR and initial VR in any valve position. These results justify our current strategy of cardiac valve re-replacement.

[Surgical treatment of ischemic mitral regurgitation]

Mitral regurgitation secondary to ischemic heart disease carries a significant mortality even after emergent open heart surgery. We report on 16 patients with mitral regurgitation associated with ischemic heart disease. The pathological findings were chorda elongation and papillary muscle dysfunction (PMD group) in 12 patients, and papillary muscle rupture (PR group in 4 patients. Preoperative characteristics were severe left ventricular failure in PMD group and high incidence of renal failure, in associated with high age in PR group. In PMD group, mitral plasty was performed in 10 patients out of 12 patients. In PR group all patients underwent mitral valve replacement. Thirteen patients underwent mitral surgery combined with coronary artery bypass grafting. No operative death was seen, one hospital death and 3 late deaths occurred. Three late deaths were seen in PMD group due to sudden death in 2 cases and arrhythmia in 1 case. One hospital death in PR group was due to multi-organ failure. We suggested incorporating these therapeutic concepts may introduce satisfactory results in surgical treatment for ischemic mitral regurgitation.

Effect of membrane surface potential on the uptake of anionic compounds by liposomes

The effect of membrane surface potential on the uptake of several anionic compounds by liposomes (large unilamellar vesicles), which contain various amounts of dipalmitoylphosphatidylserine (DPPS), was investigated. The uptake amount of four tested anionic compounds (cefixime, benzyloxyindoleacetic acid (BOIAA), ceftibuten and S-1006) decreased with an increase in the DPPS content of liposomes, and was correlated with the membrane surface potential monitored using a fluorescent dye, 8-anilino-1-naphthalene sulfonate (ANS). Moreover, for all of the tested anionic compounds, a good correlation was observed between the ratio of the uptake value (5 min) by each of the liposomes comprising various amounts of DPPS to the uptake value by liposomes containing 10% DPPS and a relative membrane surface potential monitored by ANS. On the other hand, the uptake of zwitterionic compounds (enoxacin, cephradine and benzyloxytryptophan (BOTP)) was independent of DPPS content. These results suggest that the uptake of tested anionic compounds by large unilamellar lipid vesicles is dependent on the membrane surface potential which originates in the surface negative charge.

[Pulmonary hypertension in aortic valve disease]

144 surgical patients with isolated aortic valve disease were reviewed to determine the incidence and the mechanism of pulmonary hypertension (PH). The hemodynamic data revealed PH (pulmonary artery systolic pressure of 40 mmHg or more) in 18 patients (12.6%). There was a positive correlation between left ventricular end-diastolic pressure (LVEDP) and pulmonary artery pressure. After operation the pulmonary artery pressure normalized in all cases but 2 patients in early post-operative period. In patients with aortic stenosis with PH, LVEDP/LVEDVI ratio was higher than that of patients without PH, which showed left ventricular diastolic dysfunction. In patients with aortic regurgitation with PH, the cause of elevated LVEDP was not only severe long-standing regurgitation with ventricular dysfunction, but also the imbalancement of compensation by dilated ventricle with preserved left ventricular function.

Stereoselective antagonism by enantiomers of alanine and serine of phencyclidine-induced hyperactivity, stereotypy and ataxia in the rat

Intracerebroventricular injection of the D-forms of alanine (Ala; 2-200 micrograms/rat) and serine (Ser; 20-2000 micrograms/rat) caused a dose-dependent inhibition of the ability of 10 mg/kg of phencyclidine (PCP; given i.p.) to increase automatically quantitated locomotor counts and cumulated scores of locomotion, stereotypy and ataxia for 90 min after PCP administration. D-Ala and D-Ser were found to be more potent than the corresponding L-isomers in attenuating the PCP-induction of these behavioral abnormalities. Although L-, but not D-Ser, at moderate doses (400 micrograms/rat) produced a slight decrease in cumulative ataxia scores after a 10-mg/kg PCP administration, D-, but not L-Ser, reduced the behavioral scores at large doses (more than 1000 micrograms/rat). Similarly, bilateral i.c.v. infusion of D-Ala (140 micrograms/rat) reduced the increasing effects of a lower dose of PCP (5 mg/kg i.p.) on locomotion, stereotypy and ataxia scores, whereas the L-form of Ala (140 micrograms/rat) lacked the inhibitory influence. The stereo-selectivity of the antagonism by Ala and Ser of PCP-induced abnormal behavior parallels that of the potencies of these amino acids as agonists for the strychnine-insensitive glycine site linked to the N-methyl-D-aspartate type excitatory amino acid receptor. Furthermore, the decreasing effects of D-Ala (200 micrograms/rat i.c.v.) and D-Ser (2000 micrograms/rat i.c.v.) on PCP-induced hyperactivity were antagonized by i.c.v. application of 5,7-dichlorokynurenate and 7-chlorokynurenate which are selective antagonists of the glycine modulatory site.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical effect of the combined therapy of arbekacin and imipenem/cilastatin against methicillin-resistant Staphylococcus aureus]

We evaluated the efficacy of combined therapy of arbekacin (ABK) and imipenem/cilastatin (IPM/CS) against infections by methicillin-resistant Staphylococcus aureus (MRSA). The MICs of ampicillin, cefmetazole, cefotiam, cefuzonam, flomoxef, fosfomycin, ofloxacin, minocycline, ABK and IPM/CS against clinically isolated strains of MRSA were examined. Almost all strains of MRSA were resistant to these antibiotics except ABK. Furthermore, combination of ABK and IPM/CS showed smaller MICs than that of ABK or IPM/CS alone. All fractional inhibitory concentration indices (FIC indices) of ABK plus IPM/CS were lower than 0.75. The efficacy rate of combined therapy of ABK and IPM/CS in 22 patients with MRSA infections (15 patients with pneumonia, 3 patients with chronic bronchitis, 2 patients with sepsis, a patient with subcutaneous abscess and a patient with DPB) was 68%. And no patients had adverse reactions. Six (27%) of 22 strains of MRSA were eradicated. Significant correlations were found between bacteriological effect and severity of disease, and between serum albumin level and clinical effect.

[Anaerobic respiratory infection--evaluation of methods of obtaining specimens]

Anaerobic cultures were performed on various kinds of specimens obtained from 67 patients with respiratory infections. The infections consisted of 33 cases of pneumonia, 14 cases of lung abscess, 6 cases of pyothorax, 9 cases of chronic lower respiratory tract infection, and 5 cases of infection of pulmonary cyst. Specimens included bronchoscopic specimens obtained using a single tube or protected catheter brush (PCB), transtracheal aspirate, percutaneous lung aspirate, aspirate using a suction tube through the tracheostomy or intubation tube, and pleural fluid. Anaerobes were isolated in 80% of pyothorax, 43% of lung abscess, and 15% of pneumonia (42% of aspiration pneumonia), respectively. Anaerobes isolated frequently in respiratory infections included Prevotella spp., Fusobacterium spp., and Peptostreptococcus spp. In regard to the type of specimen, bronchial aspirate obtained by bronchoscopy was useful in examination of pneumonia, and was useful as percutaneous lung aspirate in examination of lung abscess. But there was discrepancy of culture results between specimens obtained by different methods in the same patient. To confirm anaerobes as pathogens in respiratory infections, it is necessary to select an appropriate method to obtain specimens and to interpret the culture results comprehensively.

Minute virus of canines (MVC, canine parvovirus type-1): pathogenicity for pups and seroprevalence estimate

Minute virus of canines (MVC, canine parvovirus type-1) caused inapparent to severe illness in neonatal specific-pathogen-free pups exposed by the oronasal route. The experimental disease was generally mild. Four of 21 infected pups had clinical signs of respiratory illness, but only 2 pups, not euthanized during the early postinoculation period, developed severe illness or died. Principal pathologic changes included bronchitis and interstitial pneumonia with various degrees of lymphadenitis. In contrast to the reported field cases, enteric signs were absent in the experimentally infected animals. Histopathologic changes in the small intestine were mild or absent. Bronchial, bronchiolar, and alveolar epithelial cells appeared to be the sites of initial and most extensive viral growth, reflecting the pattern of histopathologic changes. The disease caused by MVC was mild in comparison to that caused by canine parvovirus-type 2. MVC now appears to be established as a cause of illness in young pups and of transplacental infections with embryo resorption. The prevalence of MVC hemagglutination-inhibiting antibodies was high (approximately 50%) in adult dog sera from widely separated geographic areas of the United States.

Exercise-induced STV1 elevation: a sign of right ventricular dysfunction in recent inferior myocardial infarction

BACKGROUND

Little is known about exercise-induced electrocardiographic ST segment shift in right-sided precordial leads, especially elevated ST in patients with subacute inferior myocardial infarction.

OBJECTIVE

To test the clinical significance of exercise-induced STV1 deviation with special regard to right ventricular function and right ventricular involvement.

DESIGN

Sixty-eight patients with recent inferior myocardial infarction (without having a left descending arterial lesion) aged 30 to 73 years (mean +/- SD, 59.1 +/- 10.0) were investigated with respect to biventricular function observed in radionuclide ventriculography and treadmill stress electrocardiographic findings.

RESULT

STV1 shift during exercise (delta STV1) had a negative linear logarithmic relationship only with the right ventricular ejection fraction (RVEF) and no correlation with the left ventricular ejection fraction (delta STV1 = 6.7604-1.7528xlnRVEF, r = 0.709, P = 0.0001). Significant STV1 elevation (delta STV1 of 0.5 mm or more) predicted right ventricular dysfunction (RVEF of 40% or less) and right ventricular infarction with sensitivities of 76% and 77%, specificities of 88% and 92%, and accuracies of 84% and 77%, respectively. Twenty patients with STV1 elevation (0.5 mm or more) showed nearly identical rest and exercise electrocardiographic findings, exercise capacities and similar stenotic lesions on coronary angiography, to 43 patients without significant STV1 elevation. Elective balloon angioplasty reduced the delta STV1 during exercise in only three of six patients (50%) with right ventricular infarction.

CONCLUSION

Exercise-induced STV1 elevation may be a useful indicator of global right ventricular dysfunction and/or right ventricular infarction in the subacute phase of myocardial inferior infarction.

Twelve years' experience with the St. Jude Medical valve prosthesis

Since July 1978, 1,284 patients have received the St. Jude Medical prosthesis (425 aortic, 636 mitral, and 223 double aortic-mitral), and the results in these patients were reviewed according to guidelines of the Society of Thoracic Surgeons. Follow-up was complete in 98%. Of 80 late deaths, 29% were valve related. The actuarial survival rate, including operative deaths, at 12 years was 81.7% and 87.1%, respectively, for aortic and mitral valve replacement, and it was 82.6% at 11 years after double valve replacement. All patients were anticoagulated with warfarin to maintain the thrombotest value between 10% and 25%, which is equivalent to between 2.8 and 1.6 times the control according to the international normalized ratio of the prothrombin time. The linearized rate of complication for aortic, mitral, and double valve replacement, respectively (expressed as the percent per patient-year), was as follows: structural deterioration, 0; non-structural dysfunction, 0.16, 0.30, and 0.20; valve thrombosis, 0.05, 0.09, and 0; thromboembolism, 1.35, 1.63, and 0.79; anticoagulant-related hemorrhage, 0.10, 0.18, and 0.10; and prosthetic valve endocarditis, 0.21, 0.06, and 0.20. Reoperation was performed in 16 patients. The freedom from reoperation rate at 12 years was 99.5% and 98.0% for aortic and mitral valve replacement, respectively, and it was 99.1% at 11 years for double valve replacement. Thus, during the 12-year follow-up in patient who received the St. Jude Medical prosthesis, the valve performed satisfactorily and with an acceptable risk of late complication even though patients were anticoagulated using a lower dose of warfarin.

Changes in the permeation rate of organic anions through the intestinal brush-border membrane with membrane surface potential

The effects of membrane surface potential on the uptake of anionic compounds by rat intestinal brush-border membrane vesicles were investigated. The uptake amount of all tested anionic compounds (ceftibuten, cefixime, benzylpenicillin, s-1006 and rentiapril) in the neutral medium (pH 7.5) was lower than that in the acidic medium (pH 5.5). Changes in surface potential of brush-border membrane vesicles were monitored using a fluorescence dye, 8-anilino-1-naphthalenesulfonate (ANS), and the results suggested an increase of a negative charge on the membrane surface proportional to the increase of the pH of medium. A good correlation was observed between the initial uptake rate of all tested anionic compounds and relative membrane surface potential monitored by ANS. Moreover, the uptake of cefixime by artificial liposome made from PC containing various amount of DPPS was measured. The uptake value of cefixime was decreased in proportion to an increase of DPPS content. These results suggest that the permeation of anionic compounds across intestinal brush-border membrane is dependent on surface potential originate in the surface negative charge.

[Directions for reoperation of patients with Björk-Shiley convexo-concave valve prosthesis, based on long-term experience]

Although a high incidence of strut fracture of the Björk-Shiley convexo-concave (C-C) valve prosthesis has been reported, it is still controversial whether the prosthesis functioning normally should be replaced electively. To clarify our policy for this issue, we reviewed 28 patients who had undergone mitral valve replacement with a C-C valve prosthesis, and evaluated long-term results according to STS guidelines. The incidence of valve-related complications expressed as % patient-year were; structural deterioration 0.30, nonstructural dysfunction 0.30, thromboembolism 1.20. There were no thrombosed valves, anticoagulant-related hemorrhage or prosthetic valve endocarditis. The actuarial free rate after valve replacement with the C-C at 10 years, constructed by the Kaplan-Meier method, were compared with those with St. Jude Medical (SJM) valve prosthesis. (1) Actuarial survival: 77.9 vs 87.3 (NS), (2) Reoperation-free: 91.6 vs 98.0 (p < 0.05), (3) thromboembolism-free: 83.7 vs 83.9 (NS), (4) Event-free (hospital death+reoperation+valve-related complications: 71.2 vs 77.7 (NS). The long-term results with the C-C were compatible to those with a SJM valve prosthesis. However, if a strut fracture occurs, it is very difficult to save the patient's life. The hospital mortality of re-replacement of valve prosthesis during the last 10 years, at our institute, was 2.6%, which is almost equal to the cumulative risk of strut fracture of the C-C valve after 10 years (3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)