Exercise-induced myocardial ischaemia complicated by paroxysmal complete atrioventricular block.

This study describes a case of exercise-induced myocardial ischaemia accompanied by complete atrioventricular block (CAVB). A 59-year-old man with major depression, treated with regular imipramine and lithium for 20 years, experienced syncope episodes during exercise. Exercise, testing initially, identified ST depression in the inferior leads, and later found CAVB resulting in syncope and seizure. The patient recovered completely after resuscitation. Myocardial ischaemic markers were negative, but 35% stenosis was detected in the distal left main coronary artery by angiography. The combined use of verapamil, nitrate and aspirin was treated as the possible coronary spasm. Repeat treadmill caused negative ischaemic study or exercise-induced arrhythmia, 7 days later. The pathophysiology of the very rare exercise-induced paroxysmal CAVB has been reviewed.

Chemical denaturation and elevated folding temperatures are required for wild-type activity and stability of recombinant Methanococcus jannaschii 20S proteasome.

The 20S proteasome from the extreme thermophile Methanococcus jannaschii (Mj) was purified and sequenced to facilitate production of the recombinant proteasome in E. coli. The recombinant proteasome remained in solution at a purity level of 80-85% (according to SDS PAGE) following incubation of cell lysates at 70 degrees C. Temperature-activity profiles indicated that the temperature optima of the wild-type and recombinant enzymes differed substantially, with optimal activities occurring at 119 degrees C and 95 degrees C, respectively. To ameliorate this discrepancy, two recombinant enzyme preparations were produced, each of which included denaturation of the proteasome by 4 M urea followed by high-temperature (85 degrees C) dialysis. The wild-type temperature optimum was restored, but only if proteasome subunits were denatured and refolded prior to assembly (a preparation designated as alpha & beta). In contrast, when proteasome assembly preceded denaturation (designated alpha + beta) the optimum temperature was raised to a lesser degree. Moreover, the alpha & beta and alpha + beta preparations had apparent thermal half-lives at 114 degrees C of 54.2 and 26.2 min, respectively, and the thermostability of the less stable enzyme was more sensitive to a reduction in pH. Attainment of wild-type activity and stability thus required the proper folding of both the alpha- and beta-subunits prior to proteasome assembly. Consistent with this behavior, dual-scanning calorimetry (DSC) measurements revealed differences in the reassembly efficiency of the two proteasome preparations. The ability to produce structural conformers with dramatically different thermal optima and thermostabilities may facilitate the determination of molecular forces and structural motifs responsible for enzyme thermostablity and high-temperature activity.

Noninvasive predictors of systemic embolism in mitral stenosis. An echocardiographic and clinical study of 500 patients.

Few predictors of systemic embolism in patients with mitral stenosis have been identified by noninvasive methods. This study used the most powerful noninvasive diagnostic tool, transthoracic echocardiography, as well as other noninvasive clinical information to look for predictors. Five hundred consecutive patients with a mitral valve area of 2 cm2 or less were studied. They were divided into two groups: group 1 consisted of 143 patients with a history of systemic embolism and group 2 consisted of 357 patients with no history of systemic embolism. Using a stepwise logistic regression on a random subsample of 400 patients, 4 independent predictors were found: the presence of atrial fibrillation (p = 0.003, relative risk [RR] = 2.3, 95% CI = 1.3, 4.2), the absence of significant tricuspid regurgitation (p = 0.008, RR = 2.5, 95% CI = 1.3, 4.9), the absence of aortic regurgitation (p = 0.022, RR = 2.2, 95% CI = 1.1, 4.2), and the presence of left atrial smoky echoes (p = 0.039, RR = 1.7, 95% CI = 1.1, 3.0). When the above model, together with significant interaction terms, was applied to the remaining 100 patients, both the Hosmer-Lemeshow and Brown goodness-of-fit statistics were not significant (p = 0.888 and p = 0.248, respectively), indicating that the fit was adequate and the model was validated. Thus, important noninvasive predictors of systemic embolism in patients with mitral stenosis can easily be obtained. Subgroups of patients with high risk of systemic embolism can be identified. This may refine our therapeutic strategies to prevent the catastrophe of systemic embolism.

Importance of adequate gas-mixing in contrast echocardiography.

Microbubble formation has been accepted as the mechanism producing contrast echoes. Comparisons of the contrast effects of various agents have been studied extensively, but the importance of gas-mixing has been less appreciated. To test the hypothesis that good gas-mixing, by facilitating microbubble formation, would enhance contrast effect, this study compared the contrast echocardiograms of ten adult patients before and after mixing carbon dioxide with various contrast agents. Contrast agents tested included a 5 percent glucose in water, vitamin B complex, vitamin C, and Cardiogreen solutions. First, we recorded echocardiograms by injecting each diluted contrast solution alone, then repeated the examinations using 10 ml of each diluted solution with 1 ml of carbon dioxide (CO2), mixed by means of a four-way stopcock. Satisfactory or excellent results were obtained in seven of ten, ten of ten, ten of ten, and ten of ten tests, respectively, after thorough gas-mixing, vs one of ten, seven of ten, eight of ten, and six of ten, respectively, before gas-mixing. We conclude that the addition of sufficient amounts of gas, followed by thorough mixing, is of great importance in contrast echocardiography. Consistently good results can be achieved with vitamin C, vitamin B or Cardiogreen solutions by this simple and safe method.

Vibroacoustic stimulation and intrauterine sound pressure levels.

The sound pressure level in amniotic fluid generated by vibroacoustic stimulation, assessed with a hydrophone placed close to the fetal head, was studied in 16 subjects. The mean recorded sound pressure level was 115 dB and the highest level was 129 dB. The range of the background noise was 63.5-80.5 dB. There was no obvious relationship between the distance from the stimulator to the hydrophone and the intrauterine sound pressure level. Although sound pressure levels are high, they are probably reduced before reaching the cochlea of the fetus because of the surrounding amniotic fluid and the fluid in the middle ear.

Effect of volume and concentration on the diffusion of botulinum exotoxin A.

OBJECTIVE: To investigate whether the volume of solution used to inject equivalent units of botulinum exotoxin A affects the diffusion of toxin and areas of rhytid diminution in the treatment of dynamic forehead lines. DESIGN: Ten volunteers with dynamic forehead lines were included. Each study patient received a single injection at a point 2.5 cm above the orbital rim on either side of the forehead with equivalent units, but in different volumes, of botulinum exotoxin A. The sides of injection were randomized; one side of the patient's forehead was injected first with 5 U of botulinum exotoxin A in 0.25 mL (2 U/0.1 mL) of preserved saline in the midpupillary line, followed by injection of the other side with 5 U in 0.05 mL of preserved saline (2 U/0.02 mL). There was a 5-fold difference in volume injected. Subjects were evaluated 14 days later for total area affected during visual inspection of the subjects' foreheads during active muscle contraction. SETTING: Private dermatology office. MAIN OUTCOME MEASURE: Visual inspection to measure the area of rhytid effacement in both height and width. RESULTS: The area affected by the botulinum exotoxin A injection was 50% greater in the side with the larger volume in 9 of 10 subjects. The average area affected was 6.05 cm(2) for the injection of the larger volume compared with 4.12 cm(2) for the injection with the smaller volume. The shape of rhytid effacement was oval, rather than round, with the average width longer than the average height. CONCLUSIONS: In this prospective, randomized, controlled study, we found that injection of botulinum exotoxin A in low concentration and higher volume resulted in greater diffusion and a larger affected area. The pattern of toxin spread is altered by muscular contraction in the injected sites. These results show that the dilution has implications on the desired effect of botulinum exotoxin A.

Importance of hyperhomocysteinemia as a risk factor for venous thromboembolism in a Taiwanese population. A case-control study.

OBJECTIVE: To determine the current status of hyperhomocysteinemia, which is a known risk for venous thrombosis (DVT), in Taiwan. SUBJECTS: 101 unselected patients with a minimum of one episode of deep leg DVT, either initial inpatients or current compliant outpatients in a teaching hospital. METHODS: Various thrombophilic risks, gene polymorphism and clinical predisposition were evaluated. RESULTS AND CONCLUSIONS: Patients presented higher fast total plasma homocysteine (hcy) levels than age- and sex-matched controls did (14.1 vs. 9.94 microM). Based on the 95th percentile of control values, hyperhomocysteinemia had a four- to nine-fold risk for DVT, irrespective of clinical predisposition, as well as other thrombophilic risks surveyed. Polymorphism of a metabolizing enzyme, methylenetetrahydrofolate reductase (MTHFR), was not associated with DVT, although homozygous thermolabile mutation tended to have higher plasma hcy levels. Factor V Leiden was absent in analysis of 80 patients. In complete evaluation (hcy, antithrombin (AT), protein S (PS), protein C (PC), lupus anticoagulant (LA), anticardiolipin antibody) of a subset of 83 patients hyperhomocysteinemia was the most prevalent risk (33.7%), with PC or PS deficiencies following (22.9%). Thus, hyperhomocysteinemia is a prominent risk for DVT in Taiwan.

Critical appraisal of exercise variables: a treadmill study.

BACKGROUND: New criteria for diagnosing ischemic response to treadmill exercise testing (TET) have continuously been proposed. Simultaneous comparison of test performances according to these criteria is likely contributory to interpreting TET and needs to be updated time after time. This study was conducted to accomplish this end. METHODS: A comparison of test performances of various TET variables for a cohort of 107 clinical normals and 139 angiographic patients with normal resting electrocardiograms was performed. Angiographic references included enumeration of diseased coronary vessels, Gensini's and Duke's coronary scores, left ventricular wall motion score and ejection fraction at rest. RESULTS: The ST-segment-related variables (depression, integral, and heart-rate-adjusted slope or index) outdid non-ST-segment variables (changes in R amplitude, the Athens QRS score, peak exercise blood pressure increment and recovery pressure ratios; most P < 0.05) in diagnosing coronary artery disease. Among them the heart-rate-adjusted ST-segment depression performed still better. This trend was not evident in identifying left main and three-vessel disease. However, correlation to the coronary scores favored the ST-segment-related criteria (r = 0.18-0.39, P < 0.05 to P < 0.001 versus r = 0.05-0.23, NS to P < 0.01) for evaluating severity of coronary artery disease. CONCLUSIONS: For patients with normal resting electrocardiograms, the adjustment of ST-segment depression for heart rate is valuable for evaluating coronary artery disease.

Endpoints of treadmill exercise testing for functional evaluation of patients with mitral stenosis.

The study was performed on 122 patients proved by catheterization to have dominant mitral stenosis so as to define proper endpoints of exercise testing for functional evaluation. This represents the 14-year experience with mitral stenosis in our exercise laboratory. Of them, we investigated 126 who completed clinically event-free Naughton treadmill exercise tests. Excess peak exercise heart rates (over 150 beats per minute, 63%) and exertional hypotensive responses (59%, probably including factitious responses due to unreliable indirect pressure readings) did not correlate with the severity of mitral stenosis. Without limiting symptoms and major ventricular arrhythmias, either of the above as endpoints may cause the test to be halted prematurely in half the cases. Ventricular arrhythmias (60%; in complex forms, 20%; possibly contaminated by aberrancy in atrial fibrillation and aggravated by digitalis/diuretics) did not correlate with severity of stenosis either, but the only one major complication we met was secondary to ventricular tachyarrhythmia. Limiting symptoms (83%; of them 94% being dyspnea/fatigue correlating with severity at P less than 0.01) and complex ventricular arrhythmias as endpoints terminated 85% of the tests safely in this series. Atrial thrombuses (34%, all non-floating) did not cause any related complications. Thus, we concluded that limiting symptoms and complex ventricular arrhythmias are the proper endpoints in evaluating the exercise capacity of patients with mitral stenosis after prior echocardiographic exclusion of those with potentially risky floating thrombus.

Diagnostic use of metoclopramide in hypertension caused by pheochromocytoma.

We studied 5-mg metoclopramide provocation in six pheochromocytomatous patients with different tumor locations, varying secretory patterns and large tumor sizes (> 12 g or equivalently) and in 14 patients with essential hypertension as part of diagnostic work-up, usually after screening with vanillylmandelic acid assay by the colorimetric method. Antihypertensive medication continued in three and five patients, respectively. Despite similar basal blood pressures patients with pheochromocytomas developed more prominent pressor responses in five of six patients than the nonpheochromocytomatous patients (P < 0.01), most (10) of the latter with negligible pressor responses. Basal plasma catecholamines were higher in each of the pheochromocytomatous patients of different secretory patterns. Further rises after provocation were seen in all pheochromocytomatous patients except one with early pressor response, and also in one nonpheochromocytomatous patient. All tests were well tolerated. Thus, we concluded that the metoclopramide test based upon joint pressor response and plasma catecholamine response can be safely used in the diagnosis of pheochromocytoma. A less stringent protocol including a short drug-off preparatory period may be a warranted compromise between feasibility and diagnostic accuracy.

Gender differences in baseline variables, therapies and outcomes in Chinese patients with acute myocardial infarction.

We prospectively studied the gender differences of baseline variables, therapies, and outcomes among a cohort of 369 Chinese patients with acute myocardial infarction from 1990 to 1995. There were 277 male and 92 female patients. The male gender had a younger mean (+/-SD) age (61.5+/-10.7 vs. 67.1+/-11.7 years, P<0.0001). Hypercholesterolemia (201.2+/-44.2 vs. 187.5+/-43.7 mg/dl, P=0.0111) and obesity (25.0 vs. 15.9%, P=0.0494) were more prominent in the female. Smoking was more prevalent in the male (78.3 vs. 18.5%, P<0.0001). The male group also had more frequent use of thrombolytic agents (19.1 vs. 9.8%, P=0.0377), beta-blockers (61.7 vs. 47.8%, P=0.0191) and heparin (25.3 vs. 12.0%, P=0.0075); but less use of angiotensin-converting enzyme inhibitors (6.9 vs. 15.2%, P=0.0149). The condition on admission was worse in the female group (Killip classification (1.5+/-0.9 vs. 1.9+/-1.0, P=0.0022), myocardial failure (8.7 vs. 2.9%, P=0.0178) and cardiomegaly (65.2 vs. 53.1%, P=0.0419). During a follow-up duration of 26.4+/-24.1 and 22.9+/-23.9 months respectively, the mortality rate was lower in the male (19.5 vs. 30.4%, P=0.0288). However after adjustment for the effect of age, the differences in Killip classification, myocardial failure, cardiomegaly and mortality became insignificant.

Extensive bullae formation in acute iliofemoral venous thrombosis.

A 58-year-old man presented with an acutely painful swollen left leg which was cyanotic and crowded with cutaneous bullae. After confirmation with color duplex ultrasound, intravenous streptokinase therapy was commenced with a bolus of 250,000 i.u. followed by maintenance infusion of 100,000 i.u. hourly for 72 hours. Treatment was changed to heparin for 14 days and then oral warfarin for another 6 months. Effacement of bullae accompanied subsidence of swelling of the leg. This case highlights the potential contribution of fluid retention in acute deep venous thrombosis to extensive bullae formation. This has not been previously reported in the literature.

Limited breast reduction by liposuction.

Traditionally, dermatologic surgeons have referred women seeking breast reduction to plastic surgeons for excisional mammoplasty. However, with recent advances in small cannula tumescent liposuction surgery, referral for such surgery may be unnecessary in some cases. Breast liposuction can reduce the size of female breasts that have essentially normal architecture with a minimum of visible scarring and an aesthetically pleasing result. We describe a method for liposuction reduction of female breasts that is safe, efficacious, and associated with high levels of patient satisfaction. Liposuction for breast reduction in women is an appropriate addition to the array of liposuction procedures available to the dermatologic surgeon.

Multicenter study of the safety and efficacy of a 585 nm pulsed-dye laser for the nonablative treatment of facial rhytides.

OBJECTIVE: The objective of this study was to assess the safety and efficacy of a 585 nm flashlamp pulsed-dye laser for the nonablative treatment of facial rhytides. METHODS: A multicenter prospective randomized controlled study on 58 volunteers was performed. A split-face approach was adopted, with one periorbital region acting as a control and the other receiving either one or two treatments. Patients were photographed and imaged three-dimensionally before and after treatment. Histologic sections were analyzed. RESULTS: Three-dimensional topographic evaluation showed improvements of 9.8% (p = .0022) and 15% (p = .0029) in surface roughness for single and double treatments, respectively. Histology revealed an increase in type I collagen messenger ribonucleic acid expression, type III procollagen, chondroitin sulfate, and grenz zone thickness. Two treatments resulted in greater improvement than one treatment. CONCLUSION: Clinical improvement was achieved following a single treatment. Further improvement was observed following a second treatment. The subjective evaluation of clinical improvement was consistent with both histologic and topographic quantitative measurements.

[Evaluation of the apical seal produced by a hybrid root canal filling method, combining lateral condensation and thermomechanical compaction].

The present study measured apical leakage to a dye in roots filled by a hybrid root canal filling method, combining lateral condensation and thermomechanical compaction. The canals of 52 extracted human maxillary anterior teeth were endodontically prepared and divided into 3 groups. Lateral condensation was used in one group. The roots of the second one were filled using thermomechanical compaction. The roots of the third group were filled using hybrid method. After immersion in Procion Brilliant Green, the roots were cleared for measuring the depth of penetration of the dye under stereomicroscope. The roots filled with the hybrid method leaked less than the lateral condensation group, yet the difference was not significant (P greater than 0.05). The roots filled with both hybrid method and lateral condensation leaked significantly less (p less than 0.05) than the thermomechanical compaction group.

Relationship between reestablishment of sarcolemma-glycocalyx ultrastructures and restoration of transmembrane potentials in cultured rat heart cells.

Simultaneous studies on sarcolemma-glycocalyx ultrastructures and electrophysiological properties of the trypsin-released rat heart cells were carried out in order to define the relationship between sarcolemmal membrane repair and transmembrane potential recovery in the long-term cultured heart cells. Based on electron microscopic observations of the trypsinized heart cells maintained in the long-term culture, serial alterations of sarcolemma-glycocalyx complex could be divided into three successive stages. A defective stage of the sarcolemma-glycocalyx complex was present in the cultured cells between day 3 and day 6 of incubation. A repaired stage of the sarcolemma-glycocalyx complex was observed in the cells from day 7 to day 9 of incubation. A well-organized stage of the sarcolemma-glycocalyx complex was seen in the cells after ten days of incubation. Sequential measurements of electrophysiological parameters of the cultured heart cells showed a diphasic evolution of maximum diastolic potential and action potential amplitude, with an initial decrease from day 3 to day 9 of incubation and a later return to normal range after ten days of incubation. There seemed a good correlation between electrophysiological properties and sarcolemma-glycocalyx ultrastructures. Thus, we conclude that restoration of the electrophysiological properties of the cultured cells is closely related to the reorganization of the defective sarcolemmal membrane.

Clinical features of familial histiocytosis.

The most commonly reported familial variant of histiocytosis is familial hemophagocytic lymphohistiocytosis. Clinically, this may be distinguished from other infantile forms by the absence of skin involvement and high incidence of leptomeningeal involvement. Eosinophilia, erythematous skin rash, alopecia, and opportunistic pulmonary infections suggest combined immunodeficiency with histiocytic response.