Focal cerebral ischemia in the mouse: description of a model and effects of permanent and temporary occlusion.

Our study is to demonstrate the advantages and disadvantages of middle cerebral artery occlusion (MCAO) model in the mouse. CD-1 mice had permanent MCAO for 24 h, or temporary occlusion for either 1 h followed by 23 h of reperfusion or 2 h of occlusion with 22 h of reperfusion. The infarct volume and blood-brain barrier disruption were smaller in the 1-h/23-h temporary occlusion than in either the 24-h permanent occlusion group or the 2-h/22-h temporary occlusion group (p<0.05). Our study demonstrates that blood flow, infarct volume, and blood-brain barrier disruption remain important markers of focal cerebral ischemia.

Computer-assisted measurement of lumbar spine radiographs.

RATIONALE AND OBJECTIVES: The authors evaluated a method for obtaining reproducible, reliable measurements from standard lumbar spine radiographs for determining the degree of spondylolisthesis, vertebral body height, intervertebral disk space height, disk space angle, and degree of vertebral body wedging. MATERIALS AND METHODS: Four to six easily defined points were identified on each vertebral body on anteroposterior and lateral plain radiographs of the lumbosacral spine of patients. From these points, the degree of spondylolisthesis, the vertebral body height, the intervertebral disk space height, the disk space angle, and the degree of vertebral body wedging were easily calculated by using well-known geometric relationships. This method requires the use of a personal computer and a standard spreadsheet program but does not require the use of any other specialized radiographic equipment, computer hardware, or custom software. RESULTS: Calculations of intra- and interobserver variability for the measurement of spondylolisthesis, disk space height, disk space angle, and vertebral body height measurement showed that the technique is extremely reproducible. CONCLUSION: This technique may prove useful in the prospective evaluation of potential candidates for lumbar spinal stenosis surgery.

Ophthalmological complications as a manifestation of burn injury.

Facial burns are a frequent component of the presentation of victims who have sustained thermal trauma, reportedly occurring in 20 per cent of burn patients. Even apparently 'f2p4r' facial injuries might well be associated with significant ocular trauma. A retrospective review of 865 patients admitted to our burn centre showed 22 per cent (192) with facial burns. Ocular involvement, defined as globe or eyelid pathology, was present in 15 per cent (127) of these patients. The aetiology and spectrum of ocular injuries is reviewed with lid burns and subsequent lid contractures, accounting for over 50 per cent of ocular complications. Serious ocular pathology necessitating enucleation occurred in only two patients. The difficulties encountered in performing a complete ophthalmological examination in the presence of facial burns are presented in conjunction with a recommended therapeutic plan.

Peroneal nerve entrapment in athletes.

Peroneal nerve entrapment is one of the less common causes of exercise-induced leg pain in competitive athletes. This type of lower extremity peripheral nerve dysfunction is usually associated with activities that subject the nerve to constant compression or repetitive trauma. Herein, we present our experience with 12 competitive athletes treated for peroneal nerve entrapment. Diagnostic electromyography results, intraoperative findings, and the results of cadaveric dissections are discussed.

Arch bar stabilization of endotracheal tubes in children with facial burns.

Endotracheal tube stabilization in children with facial burns can be difficult. Several methods rely on straps or complex devices that apply undesirable pressure to the face, potentially destroying skin grafts and making wound care difficult. Techniques that rely on a single wire or suture can be unreliable. Presented here is the arch bar method of endotracheal tube stabilization, which appears to be free of these problems. This method employs a standard dental arch bar secured to four maxillary teeth with 24-gauge stainless steel wire. The endotracheal tube is anchored to the arch bar with two pieces of wire or suture material. The arch bar method of endotracheal tube stabilization was used on three patients in the burn center at St. Christopher's Hospital for Children. Wound care and successful skin grafting were performed without difficulty. No complications related to the arch bars occurred.

Isolated avulsion of the flexor digitorum superficialis tendon.

Isolated, closed avulsion of the flexor digitorum superficialis tendon at its insertion is thought to be a rare diagnostic entity, with only six cases reported in the literature. However, we have diagnosed and treated 11 such cases, each presenting with a tender palmar mass and loss of active flexor digitorum superficialis function. Some patients had proximal interphalangeal joint contractures. Upon exploration, the retracted superficialis tendon was found to ensnare the profundus tendon at the level of the A1 pulley. Following tenolysis, flexor digitorum superficialis tendon excision, and in selected patients capsulotomies, each patient achieved good functional capacity.

Preischemic but not postischemic zinc protoporphyrin treatment reduces infarct size and edema accumulation after temporary focal cerebral ischemia in rats.

BACKGROUND AND PURPOSE: Zinc protoporphyrin (ZnPP) has multiple actions. It is an interleukin-1 antagonist as well as a hemeoxygenase inhibitor. Interleukin-1 is produced in ischemic brain and probably contributes to ischemic injury, although the role of heme oxygenase during ischemia is unknown. Whether ZnPP treatment is more effective before or after ischemia, as well as whether it is more protective in permanent or temporary cerebral ischemia, is also unknown. Therefore, we investigated the effect of ZnPP on infarction size and edema in a rodent model of temporary and permanent focal cerebral ischemia. METHODS: Two groups of adult male Sprague-Dawley rats were pretreated with either 50 mg/kg ZnPP IP or saline and subjected to permanent middle cerebral artery occlusion 30 minutes later. Four additional groups of animals were subjected to 2 hours of temporary middle cerebral artery occlusion followed by 22 hours of reperfusion. Two of these groups were pretreated 30 minutes before middle cerebral artery occlusion with either 50 mg/kg ZnPP IP or saline. The other groups received ZnPP at either 2 or 4 hours after middle cerebral artery occlusion. Regional cerebral blood flow in the ischemic cortex was monitored with laser Doppler flowmetry. Cerebral infarct size and brain water were measured 24 hours after the onset of either form of ischemia. RESULTS: Regional cerebral blood flow after occlusion was approximately 13% to 20% of baseline after either permanent or temporary ischemia. ZnPP had no effect on regional cerebral blood flow, infarct size, or edema formation in permanent ischemia. In contrast, pretreatment significantly reduced infarct size (17.2 +/- 6.6% in controls versus 6.2 +/- 2.9% in pretreated rats) and edema formation (center zone, 4.00 +/- 0.71% water in controls versus 1.18 +/- 0.26% water in pretreated rats) in the model of temporary ischemia, but treatment after occlusion had no effect. CONCLUSIONS: ZnPP treatment protected the brain when administered early in the temporary ischemia model.

Dispersion and insertion polymorphism in two small subfamilies of recently amplified human Alu repeats.

Newly isolated members of two recently propagated (young) Alu subfamilies were examined for sequence diversity and insertion polymorphism in primate genomes. The smaller subfamily (termed HS-2) is comprised of approximately 5 to 25 members, while the larger (termed Sb2) includes approximately 125 to 600 members. Individual members of these Alu subfamilies share distinguishing sets of diagnostic mutations, are well-conserved relative to each other, and have expanded in the human lineage. At least one member from each subfamily is known to be polymorphic in humans. Three newly characterized HS-2 Alu family members as well as three Sb2 Alu repeats are monomorphic (fixed) in humans. The existence of a number of Alu subfamilies that have amplified in parallel within the human genome provides compelling evidence for the simultaneous activity of multiple dispersed Alu source genes.

Outcome after laminectomy for lumbar spinal stenosis. Part I: Clinical correlations.

All patients who underwent decompressive lumbar laminectomy in the Washtenaw County, Michigan metropolitan area during a 7-year period were studied for the purpose of defining long-term outcome, clinical correlations, and the need for subsequent fusion. Outcome was determined by questionnaire and physical examination from a cohort of 119 patients with an average follow-up evaluation interval of 4.6 years. Patients graded their outcome as much improved (37%), somewhat improved (29%), unchanged (17%), somewhat worse (5%), and much worse (12%) compared to their condition before surgery. Poor outcome correlated with the need for additional surgery, but there were few additional significant correlations. No patient had a lumbar fusion during the study interval. The outcome after laminectomy was found to be less favorable than previously reported, based on a patient questionnaire administered to an unbiased patient population. Further randomized, controlled trials are therefore necessary to determine the efficacy of lumbar fusion as an adjunct to decompressive lumbar laminectomy.

Outcome after laminectomy for lumbar spinal stenosis. Part II: Radiographic changes and clinical correlations.

The pre- and postoperative lumbar spine radiographs of 119 patients who underwent decompressive lumbar laminectomy were studied to evaluate radiographic changes and to correlate them with clinical outcome. An accurate and reproducible method was used for measuring pre- and postoperative radiographs that were separated by an average interval of 4.6 years. Levels of the spine that underwent laminectomy showed greater change in spondylolisthesis, disc space angle, and disc space height than unoperated levels. Outcome correlated with radiographic changes at operated and unoperated levels. This study demonstrates that radiographic changes are greater at operated than at unoperated levels and that some postoperative symptoms do correlate with these changes. Lumbar fusion should be considered in some patients who undergo decompressive laminectomy. The efficacy of and unequivocal indications for lumbar fusion can only be determined from randomized, prospective, controlled trials, however, and these studies have not yet been undertaken.

Spinal epidural lipomatosis: two new idiopathic cases and a review of the literature.

Thoracic spinal epidural lipomatosis, a rare cause of myelopathy, is most commonly associated with exogenous corticosteroid use. The authors present the clinical, magnetic resonance imaging, computed tomography, and surgical findings for two patients with idiopathic epidural lipomatosis, successfully treated with decompressive laminectomy accompanied by fatty debulking, followed for > 3 postoperative years. They review the literature on idiopathic spinal epidural lipomatosis as well as cases associated with exogenous steroid use.

Stereotactic management of benign pineal region cysts: report of two cases.

Recent case reports describing the open resection of symptomatic benign cysts of the pineal region have noted that the results of stereotactic management of such cysts have not been reported. We report the results of the stereotactic aspiration of benign pineal region cysts in two patients with symptomatic ventriculomegaly secondary to obstruction of the aqueduct. Stereotactic aspiration produced several cubic centimeters of brown-to-yellow fluid that was negative for tumor on cytological examination. Ventriculomegaly and symptoms were relieved without complications by the procedure in one patient who remains asymptomatic after 30 months of follow-up. In the second patient, persistent ventriculomegaly demonstrated on computed tomography resulted in the placement of a ventriculoperitoneal shunt; however, this was removed several months later during an episode of appendicitis and the patient remained asymptomatic without the shunt. The symptoms and ventriculomegaly recurred 71 months postaspiration, and the cyst was reaspirated. Ten months later, she remains asymptomatic. Options for managing such patients include open resection, shunting, and stereotactic aspiration. The relative merits of each approach are discussed.

Endoscopic Nd-YAG laser treatment of colorectal neoplasms. A four-year longitudinal study.

In order to gain a longitudinal perspective of the benefits, complications, and role of the neodymium yttrium aluminum garnet (Nd-YAG) laser in the treatment of colorectal neoplasms, we performed a review of endoscopies using the laser during a 53-month period ending in January 1989. We reviewed the records of 100 patients for details of the endoscopic procedure and demographic data. Performance status and survival were critically assessed. We performed 275 procedures on 57 men and 43 women with an average age of 76.5 years. An average of 2.75 procedures, each lasting an average of 45 minutes, were performed per patient. Half of the patients had fulgurations of rectal tumors with the common indication being bleeding. Thirteen morbid events and no deaths occurred. Ninety-six per cent of the procedures were performed with the patient under intravenous sedation. The Karnofsky performance scale applied to surviving patients revealed that 90 per cent were able to care for themselves and scored greater than 70. Average survival was 5.58 months. Our results indicate that the Nd-YAG is a safe and effective tool in the treatment of colorectal neoplasms offering palliation as well as maintenance of quality of life.

Fractures of the scaphoid bone. How to handle this common wrist injury.

A combination of forces makes the scaphoid bone susceptible to fracture. The common mechanism of trauma is a force applied to the palmar aspect of the wrist while it is in extreme dorsiflexion. Because early fracture diagnosis by x-ray study is difficult, all patients with a suspicious wrist injury and tenderness in the scaphoid region should be treated as if they have a fracture until radiographs at two and four weeks are normal. Treatment usually consists of immobilization using a long or short plaster arm cast. Various treatment methods, including electrical stimulation, are used when nonunion occurs. It is important to remember that patients are mainly concerned with results, not means, as long as such means are fast, safe, and minimally disabling.

Visually elicited reaching in neonates.

Infants aged 8-16 days were shown a small ball, a picture of a ball, and a homogeneous stimulus card. Their reaching behavior was scored for each stimulus condition. a reach was defined using the following 3 criteria: (1) lateral extension of the arm, (2) arcing movement of the arm toward midline, and (3) flexion of the arm toward the upper half of the body. The mean rates of reaching per minute for the ball, the picture, and the homogeneous or blank card were 2.94, 2.78, and 1.83, respectively. t tests showed significant differences between the ball and blank-card conditions (p less than .002) and between the picture and blank-card conditions (p less than .007), but not between the ball and picture conditions. Thus, arm movements resembling reaching can be visually elicited in neonates, but they are elicited as readily by 2-dimensional as by 3-dimensional stimuli. Furthermore, infants do not refrain from reaching when a large central area of their visual field is blank. These results suggest only that the probability of reaching-like behavior is increased by the presence of a patterned visual stimulus.