- Email: [email protected]
Considerations of improving survival from out-of-hospital cardiac arrest
647
CURRENT LITERATURE
treatment of facial tumors, in anesthesiology and in the diagnosis, treatment planning, and especially case presentation of orthognathic surgical procedures. The composite can also aid in the patients’ understanding of their functional and esthetic problems, and proposed surgical remedies, as they relate to the position of the corresponding hard and soft tissues. A detailed straightforward method for creating the composite is described using a single lens reflex camera and lateral ceph x-ray machine. The procedure as outlined involves minor modifications to the lateral cephalometric radiograph and requires interaction with a photographic laboratory for film exposure, enlargement and superimposition, but seems well within the realm of both private practice and institution-based oral and maxillofacial surgeon or orthodontist.-Guy L. LANZI Reprint requests to Dr. Acharia: Functional Photography, % David A. Silverman, 210 Crossways Park Drive, Woodbury, NY 11797.
Absorbable Gelatin Film Versus Silicone Rubber Sheeting in Orbital Fracture Treatment. Parkin J, Stevens M, Stringhan J. Laryngoscope 97: 1, 1987 The effects of an absorbable gelatin film (Gelfilm) and silicone rubber sheeting on healing of orbital fractures was evaluated in adult cats. Experimental defects were made in the medial orbital wall and anterior table of the frontal sinus and evaluated six to nine weeks postimplant for new bone formation, healing progress, and inflammatory response. The authors found that there was significantly less inflammatory response with the gelatin film than the silicone rubber, with a greater number of animals showing complete bony regeneration of the defect. The silicone implants were found to have significant migration by gross inspection, which was felt to contribute to the greater inflammatory response and less bony closure. The authors concluded that the absorbable gelatin film implants are able to enhance the healing process of orbital wall defects.-BRENTON
W. BURGER
Reprint requests to Dr. Perkin: Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of
Utah School of Medicine, Salt Lake City, UT 84132. Recognition of Protein Apparently Specific to Odontogenic Keratocyst Fluids. Douglas CW, Craig GT. J Clin Path01 39: 1108, 1986 Much attention has been directed toward investigating the odontogenic keratocyst due to its aggressive nature and tendency to recur. Previous studies have shown that the concentrations of total soluble protein in fluids aspirated from keratocysts were significantly lower than those found in fluids from nonkeratinising odontogenic cysts. However, these results are of limited value because the fluids are often infected or contaminated with blood, producing a falsely increased estimate of protein content. This study used immunological techniques to search for specific components of non-serum origin in cyst fluids. Fluids from 34 cysts (18 odontogenic keratocysts, eight dentigerous cysts, and eight radicular cysts) diagnosed microscopically from conventional criteria were subjected to crossed immunoelectrophoresis, column chromatography, SDS-Page, and Western blotting techniques. A major antigen (antigen X) was detected in all examples of keratocyst fluids and was not of
serum origin. No fluids from the other types of odontogenie cysts studied contained the antigen X. Although evidence was presented in favor of antigen X being a nonkeratin component, it remains a possibility that the antigen is a keratin not present in skin. Of the 26 keratocysts studied by publication time, 100% contained antigen X, thus offering a real prospect for improvement in the reliability of preoperative diagnosis for odontogenie keratocysts.-T. B. WELCH Reprint requests to Dr. Craig: Department of Oral Pathology, The Universitv of Sheffield. 31 Claremont Crescent, Sheffield, SlO 2TA, Engiand.
Considerations of Improving Survival From Out-of-Hospital Cardiac Arrest. Weaver WD, Cobb LA, Hallstrom AP, et al. Ann Emerg Med 15:1181, 1986 Factors influencing survival rates of out-of-hospital cardiac arrest in Seattle were examined in a series of 244 cases. For each of these cases, interview of bystanders established the time of collapse and time of initiation of cardiopulmonary resuscitation (CPR). Additionally, for each case the response time of the EMS personnel was known and a tape recording of the resuscitation event was available for review. The most common rhythm associated with out-of-hospital cardiac arrest was ventricular fibrillation (VF) with an average survival rate of 25%. However, patients discovered with asystole or electro-mechanical dissociation had extremely poor survival rates (1% and 6%, respectively) despite vigorous treatment. Factors identified that influence survival rates are both the delay until initiation of basic life support and the delay until defibrillation. Survival rates decreased about 3% with each minute of delay until initiation of CPR and continued to fall (4% per minute) during the period after initiation of basic life support to delivery of the first defibrillatory shock. When CPR was begun within three minutes and quickly followed by defibrillation, 70% survival was reported. The authors encourage reducing delays until initiation of CPR and defibrillation in patients with cardiac arrest from VF by further community training in CPR and providing first responders with the equipment and skills to effect rapid defibrillation.LESTER MACHADO
Reprint requests to Dr. Weaver: Division of Cardiology, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98184.
Jaw Opening Reflex Activity in the Inferior Head of the Lateral Pterygoid Muscle in Man. Widmer CG. Arch Oral Biol 32:13.5, 1987 A study was undertaken utilizing four males and four females in an attempt to measure masticatory muscle activity. Simultaneous recordings were obtained from the inferior head of the lateral pterygoid, anterior temporalis, masseter, and digastric muscles in response to electrical stimulation of the palate. Bipolar surface recording electrodes were placed on the skin overlying the muscle fibers of the anterior temporalis, masseter, and digastric muscles. Fine wire recording electrodes were placed directly into the inferior head of the lateral pterygoid muscle via an intraoral approach. Results obtained were consistent with a jaw opening reflex in the lateral pterygoid and digastric muscles in response to electrical stimulation of low threshold or mechanoreceptor afferents. Excitation of jaw-opening muscles occurred during si-
CURRENT LITERATURE
treatment of facial tumors, in anesthesiology and in the diagnosis, treatment planning, and especially case presentation of orthognathic surgical procedures. The composite can also aid in the patients’ understanding of their functional and esthetic problems, and proposed surgical remedies, as they relate to the position of the corresponding hard and soft tissues. A detailed straightforward method for creating the composite is described using a single lens reflex camera and lateral ceph x-ray machine. The procedure as outlined involves minor modifications to the lateral cephalometric radiograph and requires interaction with a photographic laboratory for film exposure, enlargement and superimposition, but seems well within the realm of both private practice and institution-based oral and maxillofacial surgeon or orthodontist.-Guy L. LANZI Reprint requests to Dr. Acharia: Functional Photography, % David A. Silverman, 210 Crossways Park Drive, Woodbury, NY 11797.
Absorbable Gelatin Film Versus Silicone Rubber Sheeting in Orbital Fracture Treatment. Parkin J, Stevens M, Stringhan J. Laryngoscope 97: 1, 1987 The effects of an absorbable gelatin film (Gelfilm) and silicone rubber sheeting on healing of orbital fractures was evaluated in adult cats. Experimental defects were made in the medial orbital wall and anterior table of the frontal sinus and evaluated six to nine weeks postimplant for new bone formation, healing progress, and inflammatory response. The authors found that there was significantly less inflammatory response with the gelatin film than the silicone rubber, with a greater number of animals showing complete bony regeneration of the defect. The silicone implants were found to have significant migration by gross inspection, which was felt to contribute to the greater inflammatory response and less bony closure. The authors concluded that the absorbable gelatin film implants are able to enhance the healing process of orbital wall defects.-BRENTON
W. BURGER
Reprint requests to Dr. Perkin: Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of
Utah School of Medicine, Salt Lake City, UT 84132. Recognition of Protein Apparently Specific to Odontogenic Keratocyst Fluids. Douglas CW, Craig GT. J Clin Path01 39: 1108, 1986 Much attention has been directed toward investigating the odontogenic keratocyst due to its aggressive nature and tendency to recur. Previous studies have shown that the concentrations of total soluble protein in fluids aspirated from keratocysts were significantly lower than those found in fluids from nonkeratinising odontogenic cysts. However, these results are of limited value because the fluids are often infected or contaminated with blood, producing a falsely increased estimate of protein content. This study used immunological techniques to search for specific components of non-serum origin in cyst fluids. Fluids from 34 cysts (18 odontogenic keratocysts, eight dentigerous cysts, and eight radicular cysts) diagnosed microscopically from conventional criteria were subjected to crossed immunoelectrophoresis, column chromatography, SDS-Page, and Western blotting techniques. A major antigen (antigen X) was detected in all examples of keratocyst fluids and was not of
serum origin. No fluids from the other types of odontogenie cysts studied contained the antigen X. Although evidence was presented in favor of antigen X being a nonkeratin component, it remains a possibility that the antigen is a keratin not present in skin. Of the 26 keratocysts studied by publication time, 100% contained antigen X, thus offering a real prospect for improvement in the reliability of preoperative diagnosis for odontogenie keratocysts.-T. B. WELCH Reprint requests to Dr. Craig: Department of Oral Pathology, The Universitv of Sheffield. 31 Claremont Crescent, Sheffield, SlO 2TA, Engiand.
Considerations of Improving Survival From Out-of-Hospital Cardiac Arrest. Weaver WD, Cobb LA, Hallstrom AP, et al. Ann Emerg Med 15:1181, 1986 Factors influencing survival rates of out-of-hospital cardiac arrest in Seattle were examined in a series of 244 cases. For each of these cases, interview of bystanders established the time of collapse and time of initiation of cardiopulmonary resuscitation (CPR). Additionally, for each case the response time of the EMS personnel was known and a tape recording of the resuscitation event was available for review. The most common rhythm associated with out-of-hospital cardiac arrest was ventricular fibrillation (VF) with an average survival rate of 25%. However, patients discovered with asystole or electro-mechanical dissociation had extremely poor survival rates (1% and 6%, respectively) despite vigorous treatment. Factors identified that influence survival rates are both the delay until initiation of basic life support and the delay until defibrillation. Survival rates decreased about 3% with each minute of delay until initiation of CPR and continued to fall (4% per minute) during the period after initiation of basic life support to delivery of the first defibrillatory shock. When CPR was begun within three minutes and quickly followed by defibrillation, 70% survival was reported. The authors encourage reducing delays until initiation of CPR and defibrillation in patients with cardiac arrest from VF by further community training in CPR and providing first responders with the equipment and skills to effect rapid defibrillation.LESTER MACHADO
Reprint requests to Dr. Weaver: Division of Cardiology, Harborview Medical Center, 325 Ninth Avenue, Seattle, WA 98184.
Jaw Opening Reflex Activity in the Inferior Head of the Lateral Pterygoid Muscle in Man. Widmer CG. Arch Oral Biol 32:13.5, 1987 A study was undertaken utilizing four males and four females in an attempt to measure masticatory muscle activity. Simultaneous recordings were obtained from the inferior head of the lateral pterygoid, anterior temporalis, masseter, and digastric muscles in response to electrical stimulation of the palate. Bipolar surface recording electrodes were placed on the skin overlying the muscle fibers of the anterior temporalis, masseter, and digastric muscles. Fine wire recording electrodes were placed directly into the inferior head of the lateral pterygoid muscle via an intraoral approach. Results obtained were consistent with a jaw opening reflex in the lateral pterygoid and digastric muscles in response to electrical stimulation of low threshold or mechanoreceptor afferents. Excitation of jaw-opening muscles occurred during si-