Five-years experience with intravascular lead extraction. U.S. Lead Extraction Database.

From December 1988 to April 1994, the extraction of 2,195 intravascular pacing leads from 1,299 patients was attempted at 193 centers. Indications were: infection (54%, including 10% septicemia), pacemaker reoperation with removal of nonfunctional or incompatible leads (40%), and other causes (6%). Extraction was attempted via the implant vein using locking stylets and dilator sheaths, via the femoral vein using snares, retrieval baskets, and sheaths, or via both approaches.

Factors responsible for immunizations referrals to health departments in North Carolina.

Background: Despite the existence of Medicaid and other programs designed to eliminate cost as a barrier to immunization in physicians' offices, referrals to local health departments for immunizations are common. Many children leave their physicians' offices without receiving needed immunizations.

Purpose: To determine: 1) the frequency and determinants of immunization referrals to health departments in North Carolina, and 2) the factors associated with private physicians' decisions to immunize Medicaid children in their offices and participate in the state-funded vaccine replacement program.

Anaerobic biodegradability of cellulose and hemicellulose in excavated refuse samples using a biochemical methane potential assay.

Improved techniques are needed to predict potential methane generation from refuse buried in landfills. The Biochemical Methane Potential (BMP) test was used to measure the methane potential of ten refuse samples excavated from a Berkeley, CA, landfill. The test was conducted in 125-ml serum bottles containing phosphate-buffered medium and inoculated with anaerobically digested sewage sludge.

The quantitative relationship between olfactory axons and mitral/tufted cells in developing Xenopus with partially deafferented olfactory bulbs.

Partial deafferentation of the olfactory bulb in Xenopus embryos was performed to analyze the effects of afferent innervation on the development of the central olfactory structure. In an attempt to analyze a possible early inductive role of the olfactory axons, one olfactory placode was removed before differentiation of the neural tube began (stages 26-31). A morphological and quantitative analysis was performed on larvae at the onset of metamorphic climax (stage 58).

Clinical experience with the extrathoracic introducer insertion technique.

The extrathoracic approach to transvenous introducer insertion into the subclavian vein was initially described as an alternative approach in "Safe Introducer Technique for Pacemaker Lead Implantation." Since this technique was so successful as an alternative approach, it was tried as the primary approach in 213 consecutive cases. The subclavian vein was cannulated in all cases.

Morphological and quantitative evaluation of olfactory bulb development in Xenopus after olfactory placode transplantation.

We found previously that the number of olfactory axons is correlated with the number of mitral/tufted cells (output neurons of the olfactory bulb) during normal larval development. To examine the significance of this quantitative relationship, we evaluated the effects of transplanting an extra olfactory placode on the development of the larval olfactory bulb. We found that the transplanted tissue retained the normal, pseudostratified, columnar appearance and had the same cell types as normal olfactory epithelium, and the olfactory bulbs had the same laminar organization as control bulbs.

Neuroleptic malignant syndrome: a dangerous complication of neuroleptic therapy.

Neuroleptic malignant syndrome is a potentially fatal syndrome that can occur in patients taking neuroleptics or other psychotropic drugs. It is characterized by muscle rigidity, hyperthermia, altered mentation, autonomic dysfunction, increased CPK and leukocytosis. A primary factor in NMS may be a decrease in functioning of dopaminergic neurons.

Lead extraction. Indications and techniques.

Each of the extraction techniques and their ancillary tools was reported as used successfully; however, until now, no technique has been successful when used in more than a few isolated instances. The technique for intravascular countertraction and the associated tools described in this paper were devised and selected in an attempt to develop one technique to be used on all patients, with all types of leads, and with a very low complication rate. Its versatility permitted single or multiple lead extractions combined with the precision of selecting and extracting a specific lead.

Safe introducer technique for pacemaker lead implantation.

Over the last several years, an introducer approach for pacemaker lead insertion has evolved that eliminates most introducer-related complications. The approach consists of defining a safe region for intrathoracic cannulation of the subclavian vein. If specific conditions cannot be met for entering the "safe" region or if the vein cannot be found, the subclavian vein is cannulated extrathoracically.

Development of the olfactory bulb in the clawed frog, Xenopus laevis: a morphological and quantitative analysis.

The relationship between olfactory axons and the cells of the olfactory bulb during normal development was analyzed to determine whether olfactory afferent axons could play a role in the induction of olfactory bulb formation. The morphology of the olfactory bulb in Xenopus larvae from stages 26 to 58 and in adult frogs was analyzed with light and electron microscopy. Axons were first observed beneath the basal lamina of the neural tube at stages 30 and 32; at stage 32, neurons in this area of the neural tube began to differentiate.

The incidence of recurrent penetrating trauma in an urban trauma center.

In spite of the fact that penetrating trauma is an increasingly frequent cause of death and disability in America, little epidemiologic information is available on the recurrence rate or natural history of patients sustaining such injuries. The current study therefore was carried out to determine the recurrence rate of penetrating trauma in our institution. During the 12-month study period (August 1984 through July 1985), 556 (2%) of the 26,728 patients examined in our surgical emergency department had sustained penetrating trauma.

Probing the activation of the replicative origin of broad host-range plasmid R1162 with Tus, the E.coli anti-helicase protein.

The E.coli Tus protein is an anti-helicase involved in the termination of chromosome replication. The binding site for this protein, ter, was cloned into derivatives of the broad host-range plasmid R1162.

Intravascular techniques for extraction of permanent pacemaker leads.

Intravascular techniques were used to extract 226 leads from 124 patients. Indications for lead extraction were life-threatening septicemia (30%), complications of free-floating leads (2%), abandonment of pockets (40%), and replacement of malfunctioning leads (28%). Extraction tools included flexible, telescoping sheaths advanced over the lead to dilate scar tissue and apply countertraction, deflection catheters, and wire basket snares.

Development of a new technique for explantation of chronic transvenous pacemaker leads: five initial case studies.

Transvenous removal of chronic pacing leads was attempted using a special locking stylet and dilator sheaths. In five initial cases, three of seven leads were infected; six of seven leads were removed. The stylet was inserted into the conductor lumen and locked into the tip to reinforce and control the lead, permitting retraction without stretching the conductor.

Intravascular lead extraction using locking stylets and sheaths.

Chronic lead extraction using intravascular countertraction techniques was studied in patients with over 65 different lead models including passive and active fixation devices. Indications for removal of 115 leads implanted 5 days to 264 months (mean 58 months) in 62 patients (mean 65 years) included septicemia, subcutaneous tissue infection, preerosion, free-floating lead, lead trapped in valve, too many leads, pain, and vein thrombosis. The superior vena cava (SVC) approach was attempted in 101 leads and was successful in 82 attempts (71% of total leads).

Intravascular lead extraction using locking stylets, sheaths, and other techniques.

Unlabelled: Septicemia necessitates extraction of chronic pacemaker leads. Using locking stylets and sheaths to extract leads via the implantation vein (subclavian, cephalic, or jugular) and maneuvering devices, sheaths, and retrieval baskets via the femoral approach, extraction of 228 leads implanted 5 days to 240 months (mean 55 months) was attempted in 136 patients (mean 62 years) at 34 institutions. In addition to septicemia (9%) and infection (39%), total 48%, indications included prophylaxis/replacement (40%), and other (12%).

Transatrial implantation of transvenous pacing leads as an alternative to implantation of epicardial leads.

State-of-the-art pacing modalities are not readily utilized with conventional epicardial pacing lead implantation techniques. A transatrial implantation technique was developed combining a limited surgical approach with transvenous leads. Six patients who were poor candidates for transvenous implants have received DDD or DDDR pacemakers by this approach.

Computerized pacemaker patient analysis.

We have developed computer hardware and software that imports analog waveforms and other measured data from a patient into the PaceBase database system supported by any IBM PC/AT compatible. The programmable A/D converter has the capacity to acquire the pacemaker artifact from the surface ECG leads. Analysis of the pacemaker artifact permits confirmation of pulse width as well as programmability and facilitates discovery of pacemaker hardware failures otherwise undetectable.

Effect of abx, bx and pbx mutations on expression of homeotic genes in Drosophila larvae.

We have examined the patterns of expression of the homeotic gene Ubx in imaginal discs of Drosophila larvae carrying mutations in the abx, bx and pbx regulatory domains. In haltere discs, all five bx insertion mutations examined led to a general reduction in Ubx expression in the anterior compartment; for a given allele, the strength of the adult cuticle phenotype correlated with the degree of Ubx reduction. Deletions mapping near or overlapping the sites of bx insertions, including three abx alleles and the bx34e-prv(bx-prv) allele, showed greatly reduced Ubx expression in parts of the anterior compartment of the haltere disc; however, anterior patches of strong Ubx expression often remained, in highly variable patterns.

DDD pacemakers maximize hemodynamic benefits and minimize complications for most patients.

A 44-month retrospective analysis was performed on 666 pacemakers implanted at Mt. Sinai Medical Center. Mapping techniques and endocardial waveform analyses were used during lead positioning to ensure the best electrical environment.