Lack of Magainin-Like Activity in Human Cervical Tissue

PROBLEM : The cervix plays an integral role in innate immunity of the human reproductive tract. Magainins are antimicrobial and spermicidal peptides recently described in human submandibular glands. We investigated the human cervix for magainin-like peptides. METHOD : Histologic sections of frozen and paraffin embedded cervical tissue from nine subjects were separately incubated with two rabbit, polyclonal, anti-magainin antibodies (CB-2 and CB-7) to investigate for magainin-like activity in the human cervix. RESULTS : There was no specific staining of cervical columnar cells within the endocervical canal or in the endocervical crypts. Magainin-like immunoreactivity in the human submandibular gland confirmed previous observations. CONCLUSION : Antigen related to magainin-like peptides were not discovered in the human cervix.     

Multipolar Endocardial Mapping of the Right Heart Using a Basket Catheter: Acute and Chronic Animal Studies

The development of catheter-based ablative techniques for primary atrial and ventricular arrhythmias is likely to be assisted by improved techniques for systematic endocardial activation sequence mapping. RA mapping using a multielectrode basket catheter has been shown to be feasible with minimal acute toxicity in a prior study. The objectives of the current study are to investigate: (1) the utility of the basket catheter for mapping RV activation; and (2) the evolution of acute endocardial lesions produced by basket catheter use in both the RA and RV over 4–8 weeks time. A flexible, 5-spoke basket catheter bearing 25 electrode pairs was placed in the RA (n = 9) or the RV (n = 13) in 22 juvenile sheep (22–56 kg). The catheter was deployed for 0.1–4.1 hr (RA) and 0.3–3.9 hr (RV). In 20 of these 22 animals, 32 recordings were made of filtered (30–250 Hz) bipolar electrograms and surface ECG. Electrograms were timed and used to construct activation sequences based on a schematic of catheter geometry. Hearts were examined either acutely (4 RA and 9 RV studies) or 4–8 weeks after tbe procedure (5 RA and 4 RV studies). One animal undergoing RA placement had an air embolism resulting in cardiac arrest immediately prior to basket placement; all other animals were stable during placement. RA electrograms of sufficient quality to determine activation time were recorded from 82% of pairs in RA maps, and RV electrograms from 89% of pairs in RV maps. Mean activation sequence duration in RV was 16 ms versus 47 ms in RA (P < 0.0001), making construction of RV maps more difficult. Acute postmortem studies of RV placement revealed a silent apical RV puncture in one animal. Superficial abrasion or ecchymosis of RV endocardium and/or tricuspid valve were noted in six animals. Postmortem exams in both RA and RV chronic studies showed healed endocardial lesions, with only superficial scarring. Rapid RV activation mapping using a basket catheter is feasible, but requires precision recording techniques. Endocardial abrasions produced in lambs both by RA and RV placement of the catheter are healed in < 4–8 weeks, with trivial residua. The multielectrode basket catheter may be applicable to the mapping of tachycardias originating in or involving the right ventricle.     

Alternating Current Electrocution Detection and Termination by an Implantable Cardioverter Defibrillator

A patient with an ICD accidentally grasped a power line and was electrocuted. He was unable to release the cable during electrocution though he remained conscious. After receiving a shock from his ICD. the powerline was released. ICD interrogation revealed inappropriate detection of alternating current and delivery of a shock.