An improved low-formaldehyde embalming fluid to preserve cadavers for anatomy teaching

The desired properties required for successful embalming of cadavers for gross anatomy teaching include: (1) good long-term structural preservation of organs and tissues with minimal shrinkage or distortion; (2) prevention of over-hardening, while maintaining flexibility and suppleness of internal organs; (3) prevention of desiccation; (4) prevention of fungal or bacterial growth and spread within a specific cadaver and to other cadavers in the dissection room; (5) reduction of potential biohazards (spread of infection to dissection personnel and students); (6) reduction of environmental chemical hazards (especially from formaldehyde and phenol) in order to comply with increasingly severe health and safety regulations and a new awareness of possible dangers of these chemicals in the workplace; and (7) retention of colour of tissues and organs while minimising oxidation effects that result in 'browning'.     

Induced Concealed Dissimilar Atrial Rhythms

Electrophysiologic studies, including intra-atrial recordings and atrial stimulation, were performed in two patients with suspected sick sinus syndrome. Premature atrial stimuli induced atrial flutter in both patients. The arrhythmia was concealed, i.e., it was recordable only by intracavitary electrogram and invisible on surface electrocardiogram. In one case, simultaneous atrial fibrillation could be recorded in a segment of the right atrium. In this patient, the rhythm on the surface electrocardiogram changed during the study to "upper nodal" rhythm, though the atrial electrogram showed continuation of A waves at the same rate as before during sinus rhythm. It seems that atrial changes, which are frequently encountered in sick sinus syndrome, are a predisposing factor for spontaneous or inducible concealed atrial arrhythmias.     

Nonpharmacological Therapy of Supraventricular Arrhythmias: Surgery and Catheter Ablation Techniques

Treatment of supraventricular tachyarrhythmias has undergone substantial change and development over the past decade. Pharmacological approaches to management of supraventricular arrhythmias have been supplanted by nonpharmacological techniques. These nonpharmacological techniques are the subject of the present review. The first part of this review will concentrate on the nonpharmacological techniques available for the treatment of supraventricular tachycardia, excluding Wolff-Parkinson-White syndrome, whereas Part 2 will concentrate on the surgical and the ablative procedures for management of tachycardias associated with Wolff-Parkinson-White syndrome. Pacing techniques for termination of supraventricular tachycardias are beyond the scope of this article and will not be included in the discussion.     

Effects of Lidocaine on Shock-Induced Vulnerability

Introduction: Lidocaine is known to increase the defibrillation threshold (DFT) of monophasic shocks (MS) and have no effect on DFT of biphasic shocks (BS). The aim of this study was to enhance our understanding of the mechanisms of vulnerability and defibrillation through the investigation of this difference.
Methods and Results: We studied the effect of 15 μM lidocaine on shock-induced vulnerability using fluorescent imaging of Langendorff-perfused rabbit hearts. Vulnerability was assessed as vulnerable window with shock strengths of 15 to 150 V and vulnerable period (VP) with shock delivery phase of 0% to 100% of action potential duration (% APD). With MS, lidocaine caused a significant increase in both the upper limit of vulnerability (ULV, 71 ± 17 V vs 120 ± 1.5 V, P < 0.01) and upper limit of VP (91 ± 8.0% APD vs 110 ± 4.2% APD, P < 0.01). With BS, lidocaine had no effect on ULV (40 ± 3.4 V vs 45 ± 4.5 V) and did not increase the upper limit of VP (78 ± 8.9% APD vs 96 ± 12% APD, P < 0.01). Lidocaine caused reduction of the conduction velocity during pacing (0.58 ± 0.08 m/s vs 0.44 ± 0.05 m/s, P < 0.01), shock-induced break excitation (0.82 ± 0.17 m/s vs 0.30 ± 0.07 m/s, P < 0.01), and postshock reentry (0.34 ± 0.07 m/s vs 0.19 ± 0.08 m/s, P < 0.01). Lidocaine had no effect on shock-induced virtual electrode polarization.
Conclusion: Lidocaine increased MS ULV due to slowing of shock-induced break-excitation wavefronts, which resulted in enhanced probability of survival of virtual electrode induced phase singularity. Lidocaine had no effect on BS ULV because no break excitation was induced by BS. Reduction of conduction velocity by lidocaine resulted in increased dispersion of repolarization and led to upper limit of VP increase for both MS and BS. (J Cardiovasc Electrophysiol, Vol. 14, pp. S237-S248, October 2003, Suppl.)     

Substance P derivatives with photoactivatable labels in the N-terminal part of the molecule

Photoactivatable substance P (SP) derivatives containing the p-benzoylbenzoic moiety at the N-terminal α-amino group of Arg 1 or at the ε-amino group of Lys 3 were prepared. Both derivatives also had a p-hydroxyphenylpropionyl group for radioiodination. To obtain the analogue with the photolabel at Arg 1, SP was first reacted with N-hydroxysuccinimide p-hydroxyphenylpropionate, the Lys 3-modified derivative was isolated by reversed-phase high-performance liquid chromatography (HPLC), reacted with N-hydroxysuccinimide p-benzoylbenzoate and purified by HPLC. To place the photolabel at Lys 3, the order of the reactions was reversed. The structure of the derivatives obtained was confirmed by mass spectrometry. The interaction of the derivatives obtained and of their ¹²⁵I-labeled forms with the NK-1 neurokinin receptor from the rat brain, as well as with the nicotinic acetylcholine receptor from Torpedo electrocytes was analyzed. The results obtained supported by the data from the literature indicate that benzoylbenzoic acid derivatives should not be considered as universal photolabels, which ensure in all cases a high level of photo-cross-linking.     

Clinical Results with Electrophysiologist-Implanted Cardioverter-Defibrillators

With the advent of nonthoracotomy leads and smaller devices. implantation techniques for implantable cardioverters defibrillators (ICDs) have been simplified. We reviewed the outcome of pectoral ICD implantation by electrophysiologists in 51 consecutive patients, 47 males and 4 females, mean age 60 ± 12 years, presenting with aborted sudden cardiac death (14) and drug refractory hypotensive ventricular tachycardia (37). Patients were implanted with either the PCD Jewel^TM 7219D (37) or 72197C (14) Medtronic pectoral ICDs. The mean operative time was 98 ± 31 minutes. There was no operative mortality. Complications occurred in 2 (4%) patients: right ventricular lead dislodgement requiring lead repositioning occurred in 1 patient, and 1 patient treated with anticoagulants, who had received a subcutaneous patch lead, developed a hematoma not requiring surgical reintervention. The mean defibrillation threshold was 18.6 ± 5.5 J, but was significantly lower for the 7219C(14.1 ± 5.0 J) compared to the 7219D (20.6 ± 4.4J) device, P = 0.0001. A two-lead system consisting of a right ventricular electrode (RVA) and a superior vena caval lead (SVC) was utilized in 29, RVA/SVC-subcutaneous patch in 5 and active can in 17 patients, Patients were discharged after 4.3 ± 3 days. The procedure time was significantly shorter for the 7219C device (79.7 ± 18.9 vs 105.2 ± 32.8 minutes., P = 0.0035]. Over the fallow-up period of 8 ± 5 (range 1–20] months, 26% patients received appropriate therapy (95% antitachycardia pacing, 5% shock). Concomitant antiarrhythmic therapy was utilized in 41% of patients. Ninety-eight percent of patients are alive. One patient died of congestive heart failure. Clinical results with electrophysiologist-implanted pectoral ICDs demonstrate lou morbidity and no operative mortality in this clinical series and lower DFTs and shorter procedure times may be achieved with 7219C (active can) device.