Digitalization and Tele-Health Care Concept of Complementary of Traditional Medical practices by Using BIOCERAMIC Technique

Objective: Tele-health care service of alternative practice for chronic pain disease is worthwhile of developing, especially in the period of COVID-19 pandemic. Targeting on myofascial trigger points, this study was performed to assess the possible short-term pain relief and functional improvement in patients by applying the device of BIOCERAMIC material enhanced by frequencies of tempo sound and visible light spectrum (BioS&L).<br><br>Methods: Fourteen patients who participated in the procedure for the selection of trigger points for the BioS&L treatment, assessment of pain levels using a visual analog scale (VAS) analysis, and detection of abnormal resonance of 12 harmonic frequencies using a quantum resonance spectrometer (QRS).<br><br>Results: Comparing the pre-and post-treatment of BioS&L on pain score of 12 HFs(V1-V12) as measured by VAS estimated by mixed model showed 91.7% (11/12) improvement with statistically significant results. The distribution of differences in the QRS score estimated by the mixed model among participants with pre-test QRS level ≥ 2 showed 83.3% (15/16) of HFs with statistically significant results.<br><br>Conclusion: Treatment of BioS&L at trigger points providing pain relief is explained by the hypothesis of microvascular physiology and physics of wave propagation. This study provides a workshop with a concept of digitalization of complementarity and traditional medical service and tele-health care, which fulfils distant data connection and remote practice. In the period of epidemic spread, it helps to decrease close contact on both health care providers and patients.

Base on concept of traditional Chinese medicine: Experimental studies on efficacy of BIOCERAMIC Resonance to alleviate drug withdrawal symptoms

Those who are challenged by dependency on prescription drugs or suffer drug addictions have few options available to them for recovery, such as psychotherapy and physiotherapy. Here we present a new approach with clinical examples involving stimulant addiction or overdose of hypnotic drugs that were received BIOCERAMIC Resonance, which was developed based on concept of 12 meridian channels of traditional Chinese medicine, and has successful withdrawal or dose reduction benefits. We describe the whole process and the clinical outcome. And by help of our previous publication on functional MRI, we discuss the possible brain locations response to BIOCERAMIC Resonance that may be corresponding to the beneficial effects of relief of depression, sleep deprivation and other mental symptoms that associate with substance abuse and withdrawal effects. We suggest this could be potentially widely application on substances abuse.

Establishment of a basic medical science system for Traditional Chinese medicine education: A suggestion based on the experience of BIOCERAMIC technology

The aim of this review study is to present an integrated and systematic approach to meridian channels and Ashi acupuncture points based on scientific evidence. We herein establish a framework of basic medical science to explain meridian channels based on the(1) Concepts of Traditional Chinese medicine(TCM) approach using physics and physiology: (i) the physical theory of pulse sound and cardiovascular physiology: resonance of harmonic sounds and the specific frequencies arising from heartbeats, which form pathways of different meridian channels to enhance microcirculation; (ii) standing wave hypothesis to explain meridian channels; (iii) Ashi acupuncture or trigger points caused by ischemia due to inappropriate harmonic resonance of standing waves; and (2)the TCM concept strengthened by BIOCERAMIC technology: (i) ‘wave-induced flow characteristics of meridians’; (ii) the ‘Propagated sensation along meridian’ phenomenon; (iii) clinical observations of the different chief complaints of candidates in which sensation was induced along specific meridian channels; (iv) generates ‘biofield’ phenomenon composed of virtual channels of interconnecting ‘feet-hands-ears’ to different internal organs/tissues that support the principles of reflexology.

Inhibition of breast cancer with transdermal tamoxifen-encapsulated lipoplex

Background

Tamoxifen is currently used for the treatment of both early and advanced estrogen receptor (ER) positive breast cancer in pre- and post-menopausal women. However, using tamoxifen routinely to inhibit endogenous or exogenous estrogen effects is occasionally difficult because of its potential side effects.

Objectives

The aim of this study is to design a local drug delivery system to encapsulate tamoxifen for observing their efficacy of skin penetration, drug accumulation and cancer therapy.

Methods

A cationic liposome-PEG-PEI complex (LPPC) was used as a carrier for the encapsulation of tamoxifen and forming ‘LPPC/TAM’ for transdermal release. The cytotoxicity of LPPC/TAM was analyzed by MTT. The skin penetration, tumor growth inhibition and organ damages were measured in xenograft mice following transdermal treatment.

Results

LPPC/TAM had an average size less than 270 nm and a zeta-potential of approximately 40 mV. LPPC/TAM displayed dramatically increased the cytotoxic activity in all breast cancer cells, especially in ER-positive breast cancer cells. In vivo, LPPC drug delivery helped the fluorescent dye penetrating across the skim and accumulating rapidly in tumor area. Administration of LPPC/TAM by transdermal route inhibited about 86 % of tumor growth in mice bearing BT474 tumors. This local treatment of LPPC/TAM did not injury skin and any organs.

Conclusion

LPPC-delivery system provided a better skin penetration and drug accumulation and therapeutic efficacy. Therefore, LPPC/TAM drug delivery maybe a useful transdermal tool of drugs utilization for breast cancer therapy.

Evaluation of Reflexology by "BIOCERAMIC Resonance" Operation producing Weak Force Field during Simultaneous Acupoint Stimulation of Urinary Bladder Point on Subject's Ear Resulting in Electric Current Change on Urinary Bladder reflex Point on Subject's Hands, and Related New Research Finding

OBJECTIVE

It was postulated in our previous publications that the meridian channels as conceived in Traditional Chinese Medicine (TCM) are various standing waves arising from harmonic rhythmic sound frequencies originating from the human heart beat. BIOCERAMIC is an artificial material able to produce a weak force field causing different biophysical and systemic health benefits, with the key characteristics of hydrogen bonds weakening and microcirculation enhancement. Since discovering that the effects of a BIOCERAMIC field can be transmitted via sound waves propagation, we then also developed a BIOCERAMIC Resonance device to produce weak force field throughout the body, and achieve resonance with the body's meridian channels to reinforce microcirculation.

METHODS

Since our previous research proved BIOCERAMIC can produces changes in ectodermal current levels, the present evaluation on reflexology is done by the application of Electric Current Detection (ECD) to the palmar surface of the hands matching correlative organs and glands loci to reflex points according to standard reflexology. The procedure will compare changes in the electrical current observed before and after a session of BIOCERAMIC Resonance treatment on the soles of the subjects' feet. We also conducted a procedure using corona discharge (Kirlian) photography of the hands to examine whether the coronal intensities could be affected by application of the BIOCERAMIC patch. Intensities are shown on the screen of a computer using special software that categorizes intensities into five zones.

RESULTS

Under the continuous treatment of BIOCERAMIC Resonance on soles of the feet and simultaneous stimulation on the specific point on the surface of the ear representing the urinary bladder. The electrical current (Aji ampere) on the areas in the hands are decreased from the beginning of the experiment, but only the specific area on the surface of the ear representing the urinary bladder was exhibited increased of the electrical current (Aji ampere), with statistically significant difference (p<0.05). To the other study we evaluated the validity of reflexology and corona discharge (Kirlian) photography by applying BIOCERAMIC Resonance and small adhesive patches made from the BIOCERAMIC material. Significant differences were evident on four out of five different zones of the computerized images.

CONCLUSION

Our findings suggest the existence of presupposed virtual channels or reflex points on the skin surface of the feet, hands, and ears that connect or somehow reflect back to specific internal organs, as mapped out on standard charts found in reflexology. Furthermore, the depicted corona intensities from five zones shown on a computer screen of corona discharge photography seem to indicate that the volunteer subjects are affected by the BIOCERAMIC patches. This study demonstrates the operation of the BIOCERAMIC Resonance device is able to produce weak force field through the body, which is objectively measurable and thereby scientifically integrating the concepts of reflexology, meridian channels and biofield therapy.

Efficacy of gradual pressure-decline compressing stockings in Asian patients with lower leg varicose veins: analysis by general measurements and magnetic resonance image

AIM

Most applications of gradual pressure-decline compressing stockings (GPDCS) are used in the United States and Western European countries, with over a decade of clinical experiments. Up to know, there is no standard establishment of gradual pressure-decline compressing stockings for Asian patients with venous insufficiency and varicose vein formations.

METHODS

We collected data on volunteer candidates of varicose vein for general measurements and assessments and magnetic resonance imaging (MRI) by non-contrast enhanced MRV techniques, and for post processing data analysis.

RESULTS

Clinical use of GPCDS provide a mild to moderate improvement in the varicose vein conditions of patients with deep venous insufficiency by improving their deep vein circulation, by general measurements; recording major symptoms and complaint; comfort and stretching/flexibility to the candidates after using GPDCS; and area changes/flow velocity changes/available hemoglobin changes in deep veins monitored by MRI.

CONCLUSION

The benefits and data collected in these results may help in developing compression stockings standards in Taiwanese and Asian countries, and to establishing criterias for product sizes, compression levels, and related parameters.

Magnetic resonance venography evaluating veins flow for legs by application of long stretch elastic bandage

AIM

Varicose veins are a common feature of chronic venous disease that causes pain and swelling of legs. Long stretch elastic bandages are one of the methods used to prevent and treat venous disease, but diagnostic benefit by magnetic resonance imaging (MRI) is not widely promoted. This study aims to evaluate the effects of long stretch elastic bandages using a non-contrast magnetic resonance venographic (MRV) technique by detecting influence on circumferences and flow velocities of varicose and deep veins, before and immediately after application of long stretch elastic bandages.

METHODS

Twelve patients presenting with visible varicose veins underwent MRV. The level of the superficial varicose and deep veins before and after wearing long stretch elastic bandages was recorded.

RESULTS

By comparing before and after long stretch elastic bandages, all 12 cases showed statistical significant decrease of the superficial venous flow areas; 9 out of 12 cases showed statistical significant change of the superficial (decreased) and deep (increased) venous flow rates. However, due to technical limitation, over half of the cases could not record the change of the deep venous flow areas.

CONCLUSION

The non-contrast MRV technique with Cine phase contrast, is capable to detect the short term beneficial effects of long stretch elastic bandages by measuring change of the superficial venous flow areas and superficial and deep venous flow rates.

Rupture de l'artère pulmonaire par cathéter de Swan-Ganz au cours de la chirurgie cardiaque : conduite à tenir et stratégie

Pulmonary artery catheterization is almost uniformly used nowadays in cardiac surgery. Although rare, rupture of the pulmonary artery following catheterization is highly lethal. This review examines ways of avoiding its occurrence and means of improving outcomes in case of rupture.

Effects of angiotensin-converting enzyme inhibition on the development of the atrial fibrillation substrate in dogs with ventricular tachypacing-induced congestive heart failure

BACKGROUND

Atrial structural remodeling creates a substrate for atrial fibrillation (AF), but the underlying signal transduction mechanisms are unknown. This study assessed the effects of ACE inhibition on arrhythmogenic atrial remodeling and associated mitogen-activated protein kinase (MAPK) changes in a dog model of congestive heart failure (CHF).

METHODS AND RESULTS

Dogs were subjected to various durations of ventricular tachypacing (VTP, 220 to 240 bpm) in the presence or absence of oral enalapril 2 mg. kg(-1). d(-1). VTP for 5 weeks induced CHF, local atrial conduction slowing, and interstitial fibrosis and prolonged atrial burst pacing-induced AF. Atrial angiotensin II concentrations and MAPK expression were increased by tachypacing, with substantial changes in phosphorylated forms of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38-kinase. Enalapril significantly reduced tachypacing-induced changes in atrial angiotensin II concentrations and ERK expression. Enalapril also attenuated the effects of CHF on atrial conduction (conduction heterogeneity index reduced from 3.1+/-0.4 to 1.9+/-0.2 ms/mm, P<0.05), atrial fibrosis (from 11.9+/-1.1% to 7.5+/-0.4%, P<0.01), and mean AF duration (from 651+/-164 to 218+/-75 seconds, P<0.05). Vasodilator therapy of a separate group of VTP dogs with hydralazine and isosorbide mononitrate did not alter CHF-induced fibrosis or AF promotion.

CONCLUSIONS

CHF-induced increases in angiotensin II content and MAPK activation contribute to arrhythmogenic atrial structural remodeling. ACE inhibition interferes with signal transduction leading to the AF substrate in CHF and may represent a useful new component to AF therapy.

Obstruction of left ventricular outflow tract by vegetation and periaortic abscess

Echocardiography is the modality of choice for the noninvasive recognition of vegetations and abscesses that complicate endocarditis. Vegetation size is highly variable, and it has been suggested that large vegetations are related to a more complicated course. The case we present is unusual in that the echocardiographically detected vegetation was very large, highly mobile, and caused severe obstruction of the left ventricular outflow tract, which led to impaction and cardiac arrest.

Preliminary investigation of the effects of surface treatments on biological response to shape memory NiTi stents

Nickel-titanium (NiTi) offers many advantages for the fabrication of coronary stents: shape memory, superelasticity, and radiopacity. However, many authors highlighted the selective dissolution of Ni from the alloy during the corrosion process that could lead to potential toxicity. The improvement of the NiTi stent's corrosion resistance by different surface treatments (electropolishing, heat treatment, and nitric acid passivation) was reported in a previous article. In the present study a comparative biocompatibility evaluation of such stents was performed through in vitro and in vivo assays. A cell proliferation test was completed to evaluate the cytotoxicity of surface treated NiTi using human fibroblasts. Then a stent implantation was performed in rabbit paramuscular muscle to study the inflammatory response generated by the same implants. Cell proliferation tests generally indicated an in vitro biocompatibility of our samples similar to the control group. An in vivo implantation study demonstrated the gradual overall reduction with time of the fibrocellular capsule thickness surrounding the implants. After a 12-week implantation period, the fibrous capsules surrounding the different implants tended toward the same value of 0.07 mm, which suggested that all surface treatments produced a similar biological response. This low value of the fibrocellular capsule indicated that our NiTi surface treated implants were relatively inert.

Transvenous catheter ice mapping and cryoablation of the atrioventricular node in dogs

While radiofrequency catheter ablation is very effective, it does not allow for prediction of success prior to full delivery of the energy. We investigated the use of cryoablation using a new catheter on the AV node to determine (1) if a successful site might be identified prior to the ablation itself, and (2) the parameters of cryoablation of the AV node using a new cryocatheter. In eight dogs, the cryoablation catheter was advanced to the AV node to produce transient high degree AV block by lowering the temperature to a minimum of -40 degrees C (ice mapping). Transient high degree AV node block was obtained in seven of eight animals at a mean temperature of -39.9 +/- 11.6 degrees C. No significant pathological modification was found in all animals but one and, in all cases, electrophysiological parameters of the AV node measured before, 20 minutes, 60 minutes, and up to 56 days after cryoapplication were not significantly different. In the 12 other dogs, after ice mapping, cryoablation of the AV node was attempted with a single freeze-thaw cycle in 6 dogs (group I) and a double freeze-thaw cycle in the other 6 dogs (group II). Chronic complete AV block was obtained in only one animal in group I compared to all animals in group II. Ablation of the AV node is effective with a double freeze-thaw cycle using a percutaneous catheter cryoablation system. Ice mapping of the area allows for identification of the targeted site.

Promotion of atrial fibrillation by heart failure in dogs: atrial remodeling of a different sort

BACKGROUND

Studies of atrial fibrillation (AF) due to atrial tachycardia have provided insights into the remodeling mechanisms by which "AF begets AF" but have not elucidated the substrate that initially supports AF before remodeling occurs. We studied the effects of congestive heart failure (CHF), an entity strongly associated with clinical AF, on atrial electrophysiology in the dog and compared the results with those in dogs subjected to rapid atrial pacing (RAP; 400 bpm) with a controlled ventricular rate (AV block plus ventricular pacemaker at 80 bpm).

METHODS AND RESULTS

CHF induced by 5 weeks of rapid ventricular pacing (220 to 240 bpm) increased the duration of AF induced by burst pacing (from 8+/-4 seconds in control dogs to 535+/-82 seconds; P<0.01), similar to the effect of 1 week of RAP (713+/-300 seconds). In contrast to RAP, CHF did not alter atrial refractory period, refractoriness heterogeneity, or conduction velocity at a cycle length of 360 ms; however, CHF dogs had a substantial increase in the heterogeneity of conduction during atrial pacing (heterogeneity index in CHF dogs, 2. 76+/-0.16 versus 1.46+/-0.10 for control and 1.51+/-0.06 for RAP dogs; P<0.01) owing to discrete regions of slow conduction. Histological examination revealed extensive interstitial fibrosis (connective tissue occupying 12.8+/-1.9% of the cross-sectional area) in CHF dogs compared with control (0.8+/-0.3%) and RAP (0. 9+/-0.2%) dogs.

CONCLUSIONS

Experimental CHF strongly promotes the induction of sustained AF by causing interstitial fibrosis that interferes with local conduction. The substrates of AF in CHF are very different from those of atrial tachycardia-related AF, with important potential implications for understanding, treating, and preventing AF related to CHF.

Manganese mineral interactions in brain

Manganese (Mn) is an essential mineral but is toxic when taken in excess. However, whether its interactions with other minerals in organs and cells are involved in mechanisms underlying Mn toxicity is poorly understood. We designed a developmental rat model of chronic Mn treatment (Group A: 1 mg MnCl2.4H2O per ml of drinking water; Group B: 10 mg MnCl2.4H2O per ml of drinking water; Group C: 20 mg MnCl2.4H2O per ml of drinking water; Control Group given water without manganese addition). Employing the model and instrumental neutron activation analysis, we investigated two hypotheses: (i) chronic manganese treatment alters the brain regional distribution of manganese and this altered manganese distribution also leads to region-specific changes of other metals; (ii) chronic manganese treatment induces differential changes in subcellular distributions of metals and electrolytes. In the treated rats, brain Mn level showed dose-related increases, the most pronounced being noted in striatum, hypothalamus, and hippocampus: these increases also led to alterations in regional distribution pattern of Mn. In the treated rats, Fe level was increased in hypothalamus, cerebellum, hippocampus, pons and medulla, and striatum. Cu level was increased in pons and medulla, hippocampus, midbrain, and striatum. Se level was increased in cerebellum, striatum, midbrain, hypothalamus, and pons and medulla. Zn level was increased in hypothalamus and striatum. Ca level was increased in midbrain but decreased in cerebellum; however, Mg and Al levels were not markedly affected. In brains of Mn-treated rats, Mn levels in subcellular fractions were all increased, being especially marked in nuclei, mitochondria, and synaptosomes; the subcellular distributions of Fe, Cu, Zn, and Mg were differentially altered although those of Al and Ca were minimally affected. These results are consistent with our hypotheses and may have implications in manganese neurotoxicity. The cellular and molecular mechanisms underlying manganese-mineral interactions in brain are still poorly defined and merit further investigation.

Hypercalcemic cardiomyopathy associated with primary hyperparathyroidism mimicking primary obstructive hypertrophic cardiomyopathy

A 72-year-old woman presented to hospital with rapidly progressive dyspnea and chest pain on exertion. Physical findings included a grade 3/6 systolic murmur increased by the Valsalva manoeuvre. Transthoracic echocardiography revealed concentric left ventricular hypertrophy, systolic anterior motion of the mitral valve and critical dynamic outflow tract obstruction. The myocardium was strikingly heterogeneous with hyperdynamic left ventricular systolic function. Laboratory findings included severe hypercalcemia secondary to primary hyperparathyroidism. The patient's outcome was unfavourable with nephrogenic diabetes insipidus, pancreatitis, shock, severe acidosis and death. Postmortem examination confirmed the presence of severe concentric left ventricular hypertrophy, a narrowed left ventricular outflow tract and localized endocardial fibrosis of the left interventricular septum. Microscopic findings showed diffuse calcium deposits of the myocardium, coronary arteries, kidneys and lungs. This appears to be the first report of two-dimensional and Doppler echocardiographic findings in hypercalcemic cardiomyopathy mimicking obstructive hypertrophic cardiomyopathy.

Feasibility of cardiac cryoablation using a transvenous steerable electrode catheter

We investigated the feasibility of using cryogenic technology in an electrode catheter for percutaneous ablation of cardiac tissue. Despite its high success rate, radiofrequency catheter ablation has important limitations especially with regards to the treatment of ventricular arrhythmias associated with a chronic scar. Arrhythmia surgery experience has shown that freezing with a hand held probe can permanently ablate the arrhythmogenic substrate of ventricular tachycardia associated with an old scar. Moreover, cryosurgery also allows for reversible "ice mapping," in which the area likely responsible for the arrhythmia can be evaluated by suppressing its electrophysiologic properties prior to the creation of an irreversible state. A new steerable cryoablation catheter using Halocarbon 502 as a refrigerant was utilized in six dogs. Serial cryoapplications were performed in the right and left ventricles. In two dogs, we attempted reversible ice mapping of the AV node. Pathological evaluation of the lesions was done acutely in all the animals. Forty-two cryoapplications were delivered at a mean temperature of -45 +/- 9.8 degrees C. No lesion was found at pathological evaluation for 16 cryoapplications which did not achieve a temperature of less (colder) than -30 degrees C. The remaining applications resulted in 26 lesions which were hemorrhagic and sharply demarcated from normal myocardium. Histological evaluation revealed contraction band necrosis. Reversible ice mapping of the AV node was successfully achieved in two animals. Cryoablation is feasible using an electrode catheter with multiple electrodes. This technology has the potential to allow for reversible ice mapping to confirm a successful ablation target before definitive ablation.

Mycotic aneurysm of the palmar arch after endocarditis

Mycotic pseudoaneurysms of upper extremities are an infrequent complication of endocarditis. We describe a case of mycotic pseudoaneurysm of the superficial palmar arch in a patient who had acute bacterial endocarditis. We discuss operative and pathologic findings and briefly review the literature on the subject.

The orally active ET(A) receptor antagonist (+)-(S)-2-(4,6-dimethoxy-pyrimidin-2-yloxy)-3-methoxy-3,3-diphe nyl-propionic acid (LU 135252) prevents the development of pulmonary hypertension and endothelial metabolic dysfunction in monocrotaline-treated rats

Pulmonary hypertension is associated with endothelial dysfunction that may mediate or contribute to the disease process; among those abnormalities is an increase in circulating endothelin-1 levels. We investigated the effect of the orally active endothelin A receptor antagonist LU 135252 (LU) on the development of monocrotaline (MCT)-induced pulmonary hypertension and endothelial metabolic dysfunction. Rats were assigned to four groups by receiving a single dose of MCT or saline, followed by once-daily gavage with LU (50 mg/kg) or saline for 3 weeks. Plasma immunoreactive endothelin-1 levels doubled after MCT and were unaffected by LU therapy. The MCT-induced increase in right ventricular systolic pressure (72.5 +/- 15.9 mmHg) and hypertrophy (right ventricle/[left ventricle plus septum weight]; 0.58 +/- 0.08) were reduced by LU to 42.7 +/- 8.5 mmHg (P < .01) and 0.42 +/- 0.05 (P < .01), respectively. LU, however, did not modify MCT-induced pulmonary artery medial hypertrophy. Pulmonary vascular endothelial metabolic activity was evaluated in isolated lungs by measuring endothelium-bound angiotensin-converting enzyme activity using a synthetic angiotensin-converting enzyme substrate, 3H-benzoyl-phenylalanly-glycyl-proline. MCT reduced fractional 3H-benzoyl-phenylalanly-glycyl-proline hydrolysis (0.488 +/- 0.051, P < .01) which was normalized by LU therapy (0.563 +/- 0.050). LU treatment alone had no significant effect on any of these parameters. We conclude that the endothelin A antagonist LU reduces MCT-induced pulmonary hypertension and right ventricular hypertrophy and restores endothelial metabolic function. These results support the development of endothelin antagonists for the treatment of pulmonary hypertension and associated endothelial metabolic abnormalities.

Swine model of coronary restenosis: effect of a second injury

Looking for a coronary artery restenosis model closer to human pathology, a protocol of balloon injury/reinjury (plaque of dilatation) in swine coronary artery was designed. Pig coronary arteries (n = 24) were dilated for this study: 12, group 1, once (sacrifice at 10.0 +/- 2.2 weeks); 6, group 2, twice at 2-wk intervals (sacrifice at 5.2 +/- 0.2 wk); 6, group 3, twice at 4-wk intervals (sacrifice at 9.3 +/- 1.9 wk). A single overdilatation resulted in an eccentric neointimal hyperplasia representing half of the wall area (group 1, 45.6 +/- 5.1%). In animals (groups 2 and 3) subjected to redilatation, fracture length, ratio of fracture length to internal elastic lamina (IEL) circumference, and neointimal hyperplasia response were similar to those observed in group 1. In group 3, the shape of the lesion appeared more concentric and the fracture of the IEL more fragmented than in group 1. Although this model of injury/reinjury did not lead to more severe intimal hyperplasia, performing a second angioplasty at the same site did lead to a more concentric intimal response, related to multiple fractures of the IEL.

Clinical trial of retrograde warm blood reperfusion versus standard cold topical irrigation of transplanted hearts

BACKGROUND

A prospective, randomized clinical study involving 34 patients undergoing heart transplantation compared myocardial preservation of donor hearts maintained with continuous reperfusion with retrograde warm blood cardioplegia during surgical implantation versus the standard cold topical irrigation.

METHODS

Hearts in both groups were arrested with a standard crystalloid solution and maintained in a cold saline solution during transportation. In the retrograde group, cardioplegia was administered through a catheter in the coronary sinus during surgical implantation. An average of 471 +/- 30 mL of hyperkalemic crystalloid solution diluted 1:4 in warm blood from the oxygenator was infused. In the standard group, the heart was kept cold by topical irrigation of cold saline solution and was reperfused only when the ascending aorta was unclamped.

RESULTS

Preoperative characteristics of donors and recipients were similar in the two cohorts. Ischemic time average 139 +/- 12 minutes in the retrograde group compared with 130 +/- 11 minutes in the standard group (p = 0.57). Cardiopulmonary bypass time averaged 89 +/- 4 minutes in the retrograde group and 110 +/- 12 minutes in the standard group (p = 0.12). Defibrillation at reperfusion was performed in 4 patients (4/17, 24%) in the retrograde group and 12 patients (12/18, 67%) in the standard group (p = 0.01). There were no deaths in the retrograde group (0/17), whereas in the standard group, 3 patients (3/17) died of early graft failure (p = 0.11). Four early graft failures occurred in the standard group (p = 0.06). Two patients (2/17, 12%) were weaned from bypass with ventricular assist devices in the standard group. The number of subendocardial necrotic cells in the first two weekly endomyocardial biopsy specimens averaged 2.7 +/- 0.8 cells/mm2 in the retrograde group and 5.9 +/- 2.4 cells/mm2 in the standard group (p = 0.12).

CONCLUSIONS

Retrograde warm blood reperfusion appears to improve the initial recovery of transplanted hearts. The technique is easy to use and may be a useful approach to graft protection during surgical implantation.

Receptor-specific effects of acute rejection after heart transplantation on endothelium-dependent coronary relaxation in dogs

To establish the effects of acute rejection on coronary artery endothelial reactivity in a canine model of heart transplantation, we submitted seven mongrel dogs to heterotopic heart transplantation without immunosuppression for a period of 7 days. At harvesting, all transplanted hearts displayed a grade IV histologic rejection. Compared with native heart, the endothelium-dependent relaxation of the coronary arteries from the graft displayed an increased sensitivity to serotonin, a decreased sensitivity to thrombin, and no change in the response to acetylcholine and adenosine diphosphate; endothelium-independent relaxation to sodium nitroprusside was not affected. Therefore, in the canine heterotopic heart transplant model, acute rejection has no effect on endothelium-independent relaxation of coronary arteries but affects endothelium-dependent relaxation in a receptor-specific manner.

Angiosarcomas of the interatrial septum mimicking atrial myxomas

Angiosarcoma of the heart is a rare tumor. This tumor is most frequently located in the right atrium and pericardium. Localization of a tumor in the interatrial septum usually suggests atrial myxoma. We report two cases of angiosarcoma originating from the interatrial septum, one extending into the right atrium and the other into the left atrium, mimicking atrial myxomas. Transesophageal echocardiography allowed the diagnosis and comprehensive assessment of compromised structures.

Propionibacterium acnes endocarditis

Propionibacterium acnes endocarditis is a rare disease. A case of prosthetic valve endocarditis involving P acnes complicated by multiple mycotic aneurysms is reported. A brief review of the literature is presented.

[Coronary angioplasty in cardiac transplantation]

Coronary artery disease is a common complication of cardiac transplantation threatening long-term survival and its management is not well defined. Percutaneous transluminal coronary angioplasty has been proposed as a palliative and exceptional technique in some patients with limited lesions. Of 145 patients undergoing cardiac transplantation between April 1983 and January 1994, 7 underwent 10 coronary angioplasty procedures. The majority was performed in asymptomatic patients, 4 for angigraphic abnormalities alone and 3 for documented painless ischaemia. Primary angiographic success was obtained in 90% (9 out of 10) of lesions. Complication included one acute occlusion and one arteriovenous fistula. Three patients died, 1, 8 and 10 months after angioplasty. After an average of 24 months' follow-up, 3 (out of 7) patients had no cardiac events (myocardial infarction, second angioplasty, second transplantation or death). A multicentre prospective controlled trial is necessary to assess the impact of this procedure on graft and patient survival.

Increase of neutrophil adhesion and vasoconstriction with platelet deposition after deep arterial injury by angioplasty

Physiopathologic events after arterial injury are largely influenced by blood element reactions with the injured surface. To determine acute arterial reactivity to injury, simultaneous chromium 51-labeled platelet deposition and indium 111-labeled neutrophil adhesion were quantified at the site of different degrees of carotid arterial injury by balloon dilatation in 21 normal pigs. The degree of vasoconstriction distally to the dilated areas was also quantified angiographically. Arteries were classified histologically as (1) uninjured with intact endothelium; (2) mildly injured with endothelial desquamation; or (3) deeply injured with lesions extending beyond internal elastic lamina, exposing the media. We found that, compared to mild injury, deep injury was associated with greater platelet deposition (38.2 +/- 5.7 x 10(6)/cm2 vs 7.8 +/- 0.9 x 10(6)/cm2; p < 0.05), neutrophil adhesion (30.6 +/- 4.1 x 10(4)/cm2 vs 10.2 +/- 2.9 x 10(4)/cm2; p < 0.05), and vasoconstrictive response (45.5% +/- 3.2% vs 26.7% +/- 2.8%; p < 0.05). Although distally to both types of injuries, noninjured arterial segments with intact endothelium were thromboresistant to platelet deposition, neutrophil adhesion to intact endothelium was much higher after deep injury (2.2 +/- 0.4 x 10(4)/cm2) compared to mild injury (0.36 +/- 0.1 x 10(4)/cm2; p < 0.05). Like platelet deposition, neutrophil adhesion is influenced by the severity of arterial injury; both may therefore be implicated in thrombogenesis and vascular responsiveness after arterial injury in vivo.

Identification of the site of non-enzymatic glycation of glutathione peroxidase: rationalization of the glycation-related catalytic alterations on the basis of three-dimensional protein structure

Bovine erythrocyte glutathione peroxidase has been glycated in vitro by incubation in 0.05 M glucose at pH 7.4. Upon glycation the estimated KM for t-butylhydroperoxide reduction increased by approx. 3-fold in comparison to non-glycated glutathione peroxidase. The glycated protein fraction was stabilized by NaBH4 reduction and subjected to tryptic cleavage. Affinity chromatography of the tryptic digest on m-aminophenylboronate-Agarose resulted in the isolation of a single glycated peptide. The peptide was identified as T94-K117 by amino-acid composition comparison to the published amino-acid sequence for this enzyme. The glycation site has been identified as the epsilon-NH2 group of K110. Examination of the three-dimensional structure of bovine erythrocyte glutathione peroxidase indicates that K110 lies on the surface of the protein approximately 15 A away from the active site selenocysteine (SEC 45). Modeling studies indicate that K110 can communicate via H-bonded interactions with the alpha-helix containing the active site residues (SEC-45 and R50). The observed elevation of KM upon glycation of bovine glutathione peroxidase is discussed in terms of the disruption of the long range H-bonded interaction.

Mitral valve rupture following percutaneous mitral commissurotomy: existence of predictive factors

The purpose of this study was to describe the mechanism and determine predictive factors of mitral valve rupture requiring valve replacement following percutaneous mitral commissurotomy. Of the 350 consecutive patients treated by balloon mitral commissurotomy, the procedure was not completed in 16, and 11 developed acute severe mitral regurgitation requiring valve replacement: seven cases of anterior leaflet rupture, three cases of posterior leaflet rupture and one case of anterior chordal surface. These 27 group I patients were compared to the remaining 323 (group II) in whom the procedure was completed. The 11 excised valves were evaluated by an experienced pathologist. Eight of the 11 patients had an echocardiographic score < 8 (mean score 6.5 +/- 1), no valvular calcification at X-ray and double balloon percutaneous mitral commissurotomy. Microscopy in six patients showed focal fibrous thickening at the site of the rupture but no calcification. One patient developed severe mitral regurgitation due to chordal rupture with an Inoue balloon. The two remaining patients had an echo score of ten and valve calcification on X-ray. Microscopy revealed severe homogeneous chronic rheumatic mitral disease. In one of these two patients, leaflet rupture was related to an 'oversized balloon' (2 x 19 mm + 15 mm). Statistical analysis showed only echo score differences between the two groups (6.9 +/- 1.4 in group I vs 8.2 +/- 1.6 in group II, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Mediastinal and pericardial complications after heart transplantation. Not-so-unusual postoperative problems?

Of a total of 133 patients who underwent heart transplantation, 16(12%) had pericardial and mediastinal complications. Non-infectious pericardial complications, pericardial effusion and constriction were noted in ten patients, and infectious pericarditis or mediastinitis in six. Cardiac echocardiography, catheterization and magnetic resonance imaging were useful in assessing these problems. All patients underwent surgical treatment, pericardial drainage, pericardectomy or muscle flap closure. Twelve (75%) of these 16 patients are long-term survivors. In conclusion, pericardial and mediastinal complications are common after heart transplantation, and aggressive surgical treatment is most often effective in their control.

Heterogeneity of monoamine oxidase activities in synaptic and non-synaptic mitochondria derived from three brain regions: some functional implications

The heterogeneity of monoamine oxidase (MAO; EC 1.4.3.4) activities was studied in two fractions of synaptic mitochondria (SM & SM2) and one fraction of non-synaptic ("free") mitochondria (M) isolated from three rat brain regions (cerebral cortex, striatum, and pons & medulla) by the Lai and Clark (1979, 1989) method in order to elucidate the heterogeneity of MAO at the subcellular and brain regional levels. The activities toward serotonin (MAO-A), benzylamine (MAO-B), and dopamine (MAO-DA) in SM2 from all three regions were different from the corresponding values in SM. In addition, the various MAO activities in SM and SM2 showed heterogeneous distribution with respect to the three brain regions investigated. Both the distribution of MAO-A and MAO-B in non-synaptic mitochondria (M) did not show marked regional differences although MAO-DA in M varied depending on the region. These results clearly demonstrate that the distribution of MAO activities toward different substrates is heterogeneous both at the subcellular and the brain regional levels. The MAO-A:MAO-B ratios in the various mitochondrial fractions also showed trends that are consistent with this hypothesis. Furthermore, in fraction SM of synaptic mitochondria, this ratio was consistently higher than values in the other two mitochondrial fractions (SM2 & M) irrespective of the region from which they were isolated. In view of the functional importance of MAO in the regulation and compartmentation of amine metabolism, the heterogeneity of MAO at subcellular and regional levels may assume pathophysiological importance in neurological diseases (e.g., Parkinsonism) with which altered amine metabolism is associated.

Asymptomatic heterotopic thyroid tumour in the right ventricular infundibulum

An asymptomatic thyroid cardiac tumour was discovered in the right ventricular infundibulum of a 63-year-old female investigated for angina. The results of the investigation are presented: coronary angiography, echocardiography, magnetic resonance imaging, resting radioactive 201-thallium scintigraphy, dipyridamole-thallium scintigraphy, nuclear isotopic ventriculography. The tumour was successfully removed at surgery for coronary bypass. Anatomopathological description is also included.

Coronary restenosis: evaluation of a restenosis injury index in a swine model

To investigate the mechanisms of restenosis and detect useful interventions to prevent it, reliable quantitative measurements must be evaluated. Coronary arteries of domestic and minipigs (n = 18) were mechanically injured by balloon overstretching and killed at different intervals (2 to 25 weeks) after quantitative angiographic analysis. Morphometric measurements evaluated intimal hyperplasia at 0.59 +/- 0.42 mm without relation to artery size or balloon/artery ratio. Intimal hyperplasia, expressed as the ratio of neointimal area to total wall area (A), is directly related to the injury, assessed by the ratio of internal elastic lamina (IEL) fracture length to IEL circumference (B), r = 0.84, p = 0.002. Restenosis injury index, defined as A/B, provides a useful tool for the quantitative assessment of future angioplasty-related restenosis interventions.

Right ventricular rupture. A complication of postoperative mediastinitis

Mediastinitis-related right ventricular rupture is an unusual but potentially life-threatening complication of cardiac operations. Between January 1981 and December 1990, a total of 10,182 patients underwent heart operations for ischemic, valvular, and congenital heart disease at the Montreal Heart Institute. Forty-eight patients (0.5%) had postoperative mediastinitis necessitating surgical exploration and sternal debridement. The mediastinum was left open for daily irrigation with povidone-iodine and chest reconstruction was postponed. During treatment, seven patients (0.07%) had right ventricular rupture necessitating immediate surgical repair. All had ischemic heart disease before the operation. There were five women and two men, ages ranging from 52 to 65 years (mean 58 +/- 5 years). Surgical repair consisted of autologous patch covered with omentoplasty assisted with cardiopulmonary bypass. Two patients died, one during the operation of massive hemorrhage and the other 10 days after the operation of uncontrolled sepsis. Five patients survived 2 to 29 months (mean 23 +/- 10 months) after right ventricular rupture, with an overall survival of 71%. Obesity was more frequent in the patients with right ventricular rupture and was found to be a significant risk factor (multivariate analysis, p < 0.05, relative risk 3.22). Histologic examination of the right ventricle in the patient who died after a successful repair revealed fatty infiltration of the right ventricular wall. This may have predisposed the patient toward ventricular rupture. In conclusion, right ventricular rupture, an unusual event in heart surgery, is related to open sternal debridement. Favorable outcome of this complication depends on immediate surgical management, autologous repair, and the use of omentoplasty.

Brain regional distributions of monoamine oxidase activities in postnatal development in normal and chronically manganese-treated rats

To investigate the hypothesis that manganese toxicity may affect the development of the monoamine oxidases (MAOs) in brain, the regional distributions of the A (serotonin-oxidizing) and B (benzylamine-oxidizing) forms of MAO were determined in manganese-treated (1 mg or 10 mg of MnCl2.4H2O per ml of drinking water from conception onwards until the rats were used for experiments) and untreated male rats during various stages of postnatal development. The age-related variations in regional MAO-A activities (especially in pons and medulla and in cerebellum) were more marked than those in regional MAO-B activities. The MAO-A:MAO-B activity ratios decreased in all regions during development. Chronic manganese treatment (at the specified doses) did not significantly alter the age-related changes in regional MAO-A and MAO-B activities; nor were the A:B activity ratios affected. The results suggest that there is differential expression of MAO isoforms in various brain regions during postnatal development but the expression is not affected by chronic manganese toxicity.

Hypervariable 5'-terminus of hepatitis C virus E2/NS1 encodes antigenically distinct variants

Synthetic peptides representing sequences encoded at the 5'-terminus of E2/NS1 in hepatitis C virus (HCV) were constructed. Peptides synthesized based on the sequences of four distinct HCV isolates were used to develop enzyme immunoassays (EIAs) for detection of antibodies in chronic HCV patients and in HCV-infected plasma donors. HCV sequence-specific antibodies were detected among patients with chronic HCV from the United States and Italy at frequencies of 22.2% and 55.8%, respectively. Similarly, sequence-specific antibodies were detected in 54.6% of U.S. and 55.6% of Japanese commercial plasma donors who had previous evidence of HCV exposure. Our data support earlier findings of geographic variability among HCV variants. The region encoded by amino acids (aa) 380-436 was shown to contain at least one variant-specific and one conserved epitope. The data further indicate that a majority of patients chronically infected with HCV (58.1% U.S., 68.8% Italy) have antibodies directed to the 5'-terminus of the E2/NS1 gene product. We conclude that genotypic variability within the E2/NS1 gene of HCV results in antigenically distinct variants.

Successful treatment of severe heart failure caused by idiopathic giant cell myocarditis

A 53-year-old woman presented with increasing dyspnea over one month and signs of severe heart failure. A right ventricular biopsy revealed giant cell myocarditis. She was treated with a combination of cyclosporine, imuran and prednisone and improved dramatically--left ventricular ejection fraction increased from 13 to 66%. That such a response is possible has important implications with respect to both the etiology and treatment of this rare disorder.

Differential effects of metal ions on type A and type B monoamine oxidase activities in rat brain and liver mitochondria

To investigate the hypothesis that neurotoxic metals can exert their toxicity through the direct inhibition of monoamine oxidases (MAOs), the effects of several neurotoxic metal ions on type A (MAO-A) and type B (MAO-B) monoamine oxidase activities in rat forebrain nonsynaptic mitochondria and rat liver mitochondria were studied. At pathophysiological levels (10-100 microM), Cu2+ and Cd2+ are good inhibitors of brain mitochondrial MAO-A and, to a lesser extent, liver mitochondrial MAO-A. The inhibition of MAO-B activities in brain and liver mitochondria by Cu2+ and Cd2+ is only detected at the higher end of the concentration range (i.e., 50-100 microM). At the pathophysiological level of 0.5 mM, Al3+ only inhibits brain mitochondrial MAO-A but at the higher level of 2.5 mM, it inhibits both forms of MAO in brain as well as liver mitochondria. Even at toxic levels (e.g., 5 mM), neither Mn2+ nor Li+ inhibits the activities of MAO-A and MAO-B in brain and liver mitochondria. Our results are consistent with the hypothesis that some neurotoxic metals can exert their toxicity through the direct inhibition of the isoforms of MAO. Our data also suggest that the selective inhibition of brain MAO-A by Cu2+ and Cd2+ may assume pathophysiological importance in the neurotoxicity of copper and cadmium.

Neurochemical changes in rats chronically treated with a high concentration of manganese chloride

Several neurochemical parameters were studied in brain regions of rats chronically treated with a high concentration of manganese chloride (20 mg MnCl2.4H2O per ml. of drinking water) throughout development until adulthood. Large increases in Mn accumulation were found in all brain regions (hypothalamus, +530%; striatum, +479%; other regions, +152 to +250%) of Mn-treated adult rats. In these animals, Ca levels were decreased (-20 to -46%) in cerebellum, hypothalamus, and cerebral cortex but were increased (+186%) in midbrain. Mg levels were decreased (-12 to -32%) in pons and medulla, midbrain, and cerebellum. Fe levels were increased (+95%) in striatum but were decreased (-28%) in cerebral cortex. Cu levels were increased (+43 to +100%) in pons and medulla and striatum but Zn levels were decreased (-30%) in pons and medulla. Na levels were increased (+22%) in striatum but those of K and Cl remained unchanged. Type A monoamine oxidase activities were decreased (-13 to -16%) in midbrain, striatum, and cerebral cortex, but type B monoamine oxidase activities decreased (-13%) only in hypothalamus. Acetylcholinesterase activities were increased (+20 to +22%) in striatum and cerebellum. The results are consistent with our hypothesis that chronic manganese encephalopathy not only affects brain metabolism of Mn but also that of other metals.

Aortopulmonary fistula detected by echocardiography 12 years after aortoplasty for correction of ascending aorta aneurysm

We describe a case of aortopulmonary fistula in which the correct diagnosis was made by transthoracic echocardiography. The transesophageal approach, because of severe aortic dilatation, failed to provide the correct diagnosis, underlining the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms.

The human heat-shock genes HSPA6 and HSPA7 are both expressed and localize to chromosome 1

HSPA6 is a member of the human heat-shock protein gene family, encoding a basic 70-kDa protein, with unique induction characteristics (Leung et al., 1990, Biochem. J. 267: 125-132). Hybridization analyses with a somatic cell hybrid DNA panel localized the gene to chromosome 1q. The highly related HSPA7 DNA sequence (Voellmy et al., 1985, Proc. Natl. Acad. Sci. USA 82: 4949-4953) colocalized. Both HSPA6 and HSPA7 represent functional genes, as determined by analyses of mRNA from heat-shocked human cells using specific oligonucleotides, although their pattern of expression differed. Neither mRNA was detected in the absence of heat stress. A BamHI polymorphism in the HSPA7 gene was present in a predominantly Asian population.

Diabetes induced by streptozotocin causes reduced Na-K ATPase in the brain

Na-K ATPase activity in the brain decreased significantly after diabetes was induced with streptozotocin in rats. Largest decreases were observed in the hippocampus (-30%) and the cerebral cortex (-26%). Smaller decreases were observed in the thalamus (-13%), hypothalamus (-11%) and brain stem (-10%). Na-K ATPase activity in the striatum and the cerebellum were not significantly decreased. The varied decreases suggest that the regional variation of the enzyme is enhanced in the diabetic state. The enzymes of glucose metabolic pathway, namely hexokinase, lactate dehydrogenase and citrate synthase in the brain regions largely remained unchanged although increases in lactate dehydrogenase were observed in some regions. Acetylcholinesterase activity, a marker for the cholinergic system, remains unaltered in the brain during diabetes. The results are discussed with respect to the possible metabolic factors which alter the Na-K ATPase in the brain and its comparison with the peripheral nerve.

The expression of proteins and activities of metabolic enzymes in transplanted brain tissue

The middle three-fifths of the forebrains of 14-day-old embryos were obtained and transplanted into the cortical cavities of adult rats made 7 days prior to the transplantation. The expression of proteins, as revealed by 2-dimensional gel electrophoresis studies, and the activities of energy metabolizing enzymes in the mature allografts were compared with those in the 14-day-old embryonic forebrains and corresponding areas in the contralateral cerebral hemispheres of the hosts. They were shown to approach adult pattern and adult values after 10-12 weeks of growth. The biochemical findings were discussed and correlated with some of the anatomical observations.

Effects of chronic manganese treatment on rat brain regional sodium-potassium-activated and magnesium-activated adenosine triphosphatase activities during development

The effects of chronic manganese (Mn) treatments (1 and 10 mg MnCl2.4H2O per ml of drinking water) from conception onwards on brain regional development of sodium-potassium-activated and magnesium-activated adenosine triphosphatases (Na-K-ATPase and Mg-ATPase) were studied. The activities of these enzymes were determined in hypothalamus, cerebellum, pons and medulla, striatum, midbrain and cerebral cortex (which included the hippocampus) of Mn-treated and age-matched control rats at 5 postnatal ages. Both ATPase activities doubled in most brain regions between day 5 and day 20 postnatal. In pons and medulla, striatum, midbrain, and cerebral cortex, adult levels of both enzymatic activities were attained by day 20 postnatal. Na-K-ATPase activities transiently increased in the midbrain (+25%) at day 12 with the lower Mn dose and in the cerebral cortex (+31%) at day 20 with the higher Mn dose. With the higher Mn dose only, Mg-ATPase activities were increased in the hypothalamus (+20%) at day 12 and in the pons and medulla (+22%) at day 20 but were decreased in the pons and medulla (-20%) at day 60. Thus, only transient changes in enzymatic activities were observed despite dose-dependent increases in the brain levels of Mn resulting from the Mn treatment. A hypothesis regarding the role of early but transient changes in brain metabolism in the pathogenesis of the initial psychotic symptoms in Mn intoxication was proposed and discussed in relation to several other observations of a similar nature.

Coronary artery stenting after angioplasty with self-expanding parallel wire metallic stents

Parallel wire stents were implanted over exchange guide wires at percutaneous transluminal coronary angioplasty sites in 27 canine coronary arteries that were predilated with slightly oversized balloons. Stents were stainless steel, self-expandable, 3.5 to 4.5 mm in diameter, 9 to 12 mm in length, and were made of 10 wires that were longitudinally laser-welded in a zig-zag design. The compressible stent was delivered by the withdrawal of a Teflon outer catheter (4.2 to 4.9F) and the push of a polyethylene inner catheter. Aspirin, 80 mg per day, was given from the day before the study began, and heparin (150 U/kg) was administered during implantation. Quantitative angiography and pathologic examinations were performed at day 0 and at weeks 2, 4, 12, 26 and 52. The coronary angiographic diameter at the stent site immediately after stenting marginally increased from diameter before stenting: 3.22 +/- 0.40 mm versus 3.14 +/- 0.37 mm (p = 0.03), and during a mean of 14 weeks of follow-up, remained unaltered from immediate post-stenting: 3.29 +/- 0.43 mm versus 3.22 +/- 0.40 mm (p = NS) with no stent displacement. Comparisons of patency and thrombosis between heparin-coated and uncoated stents, between left anterior descending and circumflex arteries, and among the three different diameters of stents showed uniformly good results. At microscopy, the wires were oriented perfectly and embedded in the arterial wall, and by 2 weeks they were covered by mucopolysaccharide ground substance, smooth muscle cells, and an almost complete monolayer of neoendothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro and in vivo effects within the coronary sinus of nonarcing and arcing shocks using a new system of low-energy DC ablation

DC shocks within the coronary sinus have been abandoned because of the risk of cardiac rupture and tamponade. Catheter ablation using DC energy to electrodes straddling the ostium of the coronary sinus, when used clinically, has been reported to result in cardiac tamponade in as many as 16% of patients. A new system of energy delivery maximizes voltage while decreasing the undesirable effects caused by barotrauma. This system includes 1) a low-energy ablation power supply with a brief time-constant capacitive discharge that delivers up to 40 J and 3,000 V and 2) a low-energy ablation catheter with a contoured distal electrode. We performed in vitro and in vivo studies of this new system and compared arcing shocks with nonarcing shocks. Ablations were performed using unipolar distal shocks (D) and unipolar shocks to both electrodes made electrically common (P-D). In vitro studies were done in a large tank filled with physiological saline while recording voltage, current, and pressure. High-speed cinematography (32,000 frames/sec) of shocks of 10-40 J permitted detailed analysis of the vapor globe. Anodal shocks of less than 20 J showed no arcing or only minimal vapor globe formation. For D and P-D anodal shocks of 40 J, the diameters of the vapor globe were 31 and 22 mm, respectively, corresponding to pressure recordings of 11 and 4.9 atm. The pressure rise lasted less than 50 mu sec. In vivo studies involved 18 dogs that received nonarcing shocks (one to six shocks of 15 J) and 18 dogs that received arcing shocks (one to three shocks of 40 J). Each group was divided between D and P-D shocks; catheter ablation was performed at a mean +/- SEM distance of 2.94 +/- 0.92 cm within the coronary sinus. All dogs tolerated the procedure without cardiac rupture or tamponade. When killed 2-4 days later, the dogs had edema and hyperemia or hemorrhage in the area of the coronary sinus. We compared the effects of multiple (three to six) nonarcing shocks with the effects of one to three arcing shocks. Disruption or rupture of the coronary sinus within the epicardial fat space occurred in two of 12 dogs (17%) with multiple nonarcing shocks but in 13 of 18 dogs (72%) with arcing shocks (p less than 0.003). Occlusion of the coronary sinus occurred in two of 12 dogs (17%) with multiple nonarcing shocks and in nine of 18 dogs (50%) with arcing shocks (p less than 0.06).(ABSTRACT TRUNCATED AT 400 WORDS)

Neuronal and photoreceptor differentiation of retinoblastoma in culture

This study describes an in vitro system, which favors attachment and differentiation of primary retinoblastoma cells. Indeed, tumor cells from primary retinoblastomas were successfully grown as long-term monolayer cultures, using collagen type-1 coated flasks, preincubation of tumor cells in fetal calf serum and a medium richly supplemented with serum. This reliable system allowed growth and attachment and induced differentiation towards neuronal and photoreceptor morphology. Each of the nine tumors studied showed substantial cell proliferation and differentiation. Cells with glial characteristics were observed in lower numbers. Furthermore, in five cell-lines, some cell clusters showed pigmentation characteristic of pigment epithelial cells (PE). By electron microscopy, a significant proportion of cells showed conventional neuronal differentiation; others formed typical Flexner-Wintersteiner rosettes with individual photoreceptor cells showing a more highly differentiated pattern quite similar to fleurette inner segments. Immunohistochemical studies did not reveal evidence of transition between undifferentiated retinoblastoma cells and glial cells, although foci of multipolar cells were found resembling glial elements and containing glial fibrillary acidic protein. Thus no definite sign of glial differentiation was observed. These results show that most primary retinoblastoma cells can grow in attachment culture and differentiate into at least two distinct morphological cell types. This study also offers a potentially rewarding system to analyse the factors controlling growth and differentiation of human tumor cells in vitro.