Scalp electrode placement by EC2 adhesive paste in long-term video-EEG monitoring.

OBJECTIVE: To evaluate the usefulness of an adhesive paste named EC2 (Grass-Telefactor) in comparison with collodion, for scalp electrodes placement in patients with drug resistant partial epilepsy monitored by long-term video-EEG. METHODS: A total of 40 patients with drug resistant partial epilepsy participated in the study. In 20 patients, electrode placement on the scalp was made with collodion (group C) whereas in the remaining patients EC2 was used (Group P). After the electrode placement (T1) and after 24 h of recording (T2), the impedance of the electrodes was measured. Moreover, the time required to apply the electrodes and for their daily maintenance was calculated and recorded for all patients who entered the study. RESULTS: At each observation, group C showed mean values of electrode impedance significantly higher that the group P (T1: 16.8 k omega; T2: 6.5 k omega vs T1: 2.4 k omega; T2: 4.0 k omega, respectively) (P < 1 x 10(-5)). The time required to make the montage and to provide its daily maintenance was significantly shorter in group P than in group C [20.8 and 10.5 min vs 44.3 and 19.7 min, respectively (P < 1 x 10(-5))]. CONCLUSIONS: We found that the use of EC2 paste in scalp electrode attachment is less time consuming, with better recording quality as a result of lower electrode impedance values, than the use of collodion. SIGNIFICANCE: EC2 paste may substitute collodion in electrode placement for long-term video-EEG monitoring, with an optimal cost-benefit ratio in terms of recording performance, time consumption, and safety.

Controlled release of anti-inflammatory agent alpha-MSH from neural implants.

Si-multi-electrode arrays implanted into brain tissue for long-term recording lose electrical connectivity due to the post-implantation inflammatory reaction. This inflammatory reaction creates a physical and electrical gap between the electrode and the surrounding neurons. In this study, novel nitrocellulose-based coatings were developed for the sustained delivery of the anti-inflammatory neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH). alpha-MSH was incorporated in micron-scale nitrocellulose coatings and slow, sustained release over 21 days was attained in vitro. The alpha-MSH released on day 21 was still bioactive, and successfully inhibited nitric oxide (NO) production by LPS-stimulated microglia. The amount of initial drug loading directly affected the release rate, with higher initial loading increasing the mass released but not the percent of drug released. The surface morphology and thickness of the coatings were examined by scanning electron microscopy (SEM) and profilometry. In addition, impedance measurement showed that the alpha-MSH loaded nitrocellulose coatings reduced the magnitude of electrode impedance at the biologically relevant frequency of 1 kHz. In conclusion, nitrocellulose-based, bioactive coatings that release anti-inflammatory agents without increasing the impedence of the electrode were successfully fabricated. These coatings have the potential to reduce inflammation at the electrode-brain interface in vivo, and facilitate long-term recordings from Si-multi-electrode arrays.

Preparation of (188) Re-labeled paper for treating skin cancer.

For homogeneous delivery of beta radiation to skin cancer, we developed a simple method for preparing (188) Re-labeled nitrocellulose paper. The homogeneity and stability of the labeled paper were investigated. Absorbed dose estimates were calculated using the Monte-Carlo method. A 74-MBq (188) Re-labeled paper with 1-cm diameter delivered 147.2 Gy up to 1-mm depth after 2-h irradiation. Animal experiments on tumor-bearing mice showed that 50 Gy is an adequate dose for treating skin cancer. Tumors disappeared 7 days after irradiation in all the groups irradiated by 50 or 100 Gy. The (188) Re-labeled paper provided a convenient, economical, effective, and non-invasive method of treating skin cancer.

Prevention of intraoperative contamination from large ulcerative cutaneous lesions.

A method for managing head and neck malignancies with cutaneous ulceration prior to excision is described. At our institution all lesions with cutaneous extension and erosion have been treated in this manner prior to excision. The exact number of treated cases, however, is unknown, since this number is not placed in the medical record. Although the risk of tumor "take" resulting from the spillage or implantation of tumor cells from an ulcerated lesion is probably small, the previously described technique is simple and inexpensive and should be employed as a precautionary measure to further minimize this risk.

The problem of dehydration and healing of burn wounds.

In an experiment on rats, a partial thickness burn wound 20 mm in diameter was produced on the dorsum. Half the wound area was left untreated, the other half painted with elastic collodion. Examination on the 10th day following the intervention confirmed that prevention of dehydration can save a good proportion of thermally damaged tissue. It was also shown that prevention of dehydration results in a marked delay in wound healing.

Ingrown toenail treated with cotton collodion insert.

Separating the distal anterior tip and lateral edges of an ingrown toenail from the adjacent soft tissue with a wisp of absorbent cotton coated with collodion gives immediate relief of pain and provides a firm runway for further growth of the nail. The collodion coating fixes the cotton in place, waterproofs, and permits bathing. This simple office method was successfully used on 86 private patients. It is not applicable in patients with infected acute paronychia.

Allergic contact dermatitis to colophony included in the formulation of flexible collodion BP, the vehicle of a salicylic and lactic acid wart paint.

The authors describe two cases of allergic contact dermatitis to colophony included in the formulation of flexible collodion BP, the vehicle of a wart paint. Patch and repeated open application tests confirmed absence of contact allergy to other constituents. The patients were known to be allergic to various adhesive plasters. The use of flexible collodion USP, which does not contain colophony, is highly advisable whenever possible.

Immunization of mice and rabbits by intrasplenic deposition of nanogram quantities of protein attached to Sepharose beads or nitrocellulose paper strips.

Two novel immunization methods designed for immunization with small quantities of antigen, immobilized on a solid matrix and without the use of adjuvant, are presented. The major test antigen used in order to evaluate these methods was bovine serum albumin (BSA). It was deposited in the spleen of mice and rabbits, either attached to Sepharose beads (Pharmacia Sepharose 4B) or to nitrocellulose (NC) paper strips (Millipore). BSA was attached to NC by direct application or by electroblotting after SDS-polyacrylamide gel electrophoresis. The antibody response in mouse and rabbit serum, after intrasplenic immunizations with various quantities of antigen, was analyzed in an ELISA standard procedure. In mice, an antibody response in serum was detected after three intrasplenic immunizations with a total quantity of 73.6 ng BSA bound to Sepharose beads and after two immunizations with a total quantity of 800 ng BSA attached to NC. Determination of the antigen-binding to NC and the clearance rate of antigen attached to NC deposited in the spleen of mice was performed with 125I-labeled BSA. In rabbits, an antibody response in serum was detected after a single intrasplenic immunization with 2.6 micrograms BSA attached to NC. When testing human insulin and sheep prolactin, attached to NC, as antigens in intrasplenic immunization of rabbits, an antibody response was found after a total quantity of 3.2 micrograms insulin and 10.5 micrograms prolactin, respectively.

Involuting common warts. Clinical and histopathologic findings.

Patterns of regression in common warts were studied. Patients with multiple verrucae vulgaris lesions applied topical agents to the warts and were observed at regular intervals until the lesions disappeared. Regression took place without the warts turning black in all but one instance. All warts did not disappear simultaneously; some lesions persisted weeks after others had disappeared. Microscopic examination in five patients of a wart persisting after most had regressed demonstrated mononuclear cell infiltration, exocytosis, and degenerative epidermal changes. Failure to demonstrate cellular infiltration in regressing common warts in earlier studies was probably due to concentration on studying only warts that had turned black. The regression of some of the warts in patients with multiple common warts may serve as an indicator that involution is in progress. Utilization of this observation to recognize clinically the period of involution may make possible studies during the critical phase of the involutionary process.