Evaluation of 2,3,5-triphenyltetrazolium chloride as a stain for detection and quantification of experimental cerebral infarction in rats.

We have evaluated the use of 2,3,5-triphenyltetrazolium chloride (TTC) as an histopathologic stain for identification of infarcted rat brain tissue. The middle cerebral artery (MCA) of 35 normal adult rats was occluded surgically. At various times after surgical occlusion, rats were sacrificed and brain slices were obtained and stained with TTC or hematoxolin and eosin (H & E); the size of the area of infarcted tissue stained by each method was quantified.

Is computed tomographic scanning necessary in patients with tentorial herniation? Results of immediate surgical exploration without computed tomography in 100 patients.

Computed tomographic (CT) scans are performed on virtually all patients with severe head injury at the time of admission. Because of the time involved in obtaining these studies, the evacuation of significant intracranial mass lesions is delayed. To avoid such delays, the authors performed burr-hole exploration for the diagnosis of intracranial hematomas before CT scans were obtained in 100 consecutive head-injured patients with clinical signs of tentorial herniation or upper brain stem dysfunction upon admission to the emergency room.

Traumatic intracerebral hematomas: timing of appearance and indications for operative removal.

Immediate and delayed traumatic intracerebral hematomas (ICH) can produce devastating secondary brain damage after severe head injury. The relationship between the initial injury and eventual occurrence, size, and time of appearance of such hematomas is not well understood, but has great importance since delayed appearance may necessitate delayed surgical decompression of developing lesions not present on early CT scans. We reviewed the records of 35 consecutive patients with operated post-traumatic ICH to document when these lesions appeared on CT, what were the indications for surgery, and what was eventual outcome.

Rat middle cerebral artery occlusion: evaluation of the model and development of a neurologic examination.

We have examined the incidence and size of infarction after occlusion of different portions of the rat middle cerebral artery (MCA) in order to define the reliability and predictability of this model of brain ischemia. We developed a neurologic examination and have correlated changes in neurologic status with the size and location of areas of infarction. The MCA was surgically occluded at different sites in six groups of normal rats.

Nuclear magnetic resonance imaging and spectroscopy in experimental brain edema in a rat model.

Many aspects of the use of high-resolution nuclear magnetic resonance (NMR) imaging in the examination of brain edema have not been fully explored. These include the quantitation of edema fluid, the ability to distinguish between various types of edema, and the extent to which tissue changes other than a change in water content can affect NMR relaxation times. The authors have compared NMR relaxation times obtained by both in vivo magnetic resonance imaging (MRI) and in vitro NMR spectroscopy of brain-tissue samples from young adult rats with cold lesions, fluid-percussion injury, hypoxic-ischemic injury, bacterial cerebritis, and cerebral tumor.

Magnetic resonance imaging in the evaluation of nimodipine-treated acute experimental focal cerebral ischemia.

We evaluated the sensitivity of magnetic resonance (MR) imaging in documenting effects of nimodipine in experimental focal cerebral ischemia. Twenty-five Sprague Dawley rats underwent unilateral occlusion of the middle cerebral artery and were imaged at different intervals thereafter. Neuropathologic and neurologic data were correlated with MR imaging results.

Combined magnetic resonance imaging and spectroscopy in experimental regional injury of the brain. Ischemia and impact trauma.

Combined magnetic resonance imaging (MRI) and spectroscopy (MRS) allows unique experimental insights into the central nervous system (CNS) disorders. Clinical applications are forthcoming. In order to address the potential clinical uses of MRI/MRS, experimentally induced focal brain lesions were evaluated with this modality.

Experiments on the efficacy and toxicity of locoregional chemotherapy of liver tumors with 5-fluoro-2'-deoxyuridine (FUDR) and 5-fluorouracil (5-FU) in an animal model.

For the investigation of locoregional chemotherapy of liver neoplasms we developed a standardized animal model in the rat. Continuous infusion therapy or repeated bolus injections of FUDR or 5-FU were given via the hepatic artery, the portal vein or the vena cava in tumor-bearing animals. The efficacy of the treatment was determined by measuring the tumor volume 3 weeks after tumor cell implantation.

NMR imaging and spectroscopy of experimental brain edema.

A canine model of experimental brain edema utilizing the classic cold lesion technique was used to identify the optimal nuclear magnetic resonance (NMR) spin-echo imaging parameters needed to detect cerebral edema with maximum sensitivity. Each animal was studied with four separate spin-echo sequences, utilizing pulse intervals ranging from 0.5 to 2.

Outcome from severe head injury in children and adolescents.

A consecutive series of 37 children (17 years old and under) with severe head injury is presented. The data confirm that morbidity and mortality are lower in children than in adults: 51% of these young patients had a good recovery or moderate disability at 6 months. The mortality rate in this series (33%) is higher than in some reports, but probably more closely approximates the death rate from these injuries in an unselected pediatric population than do statistics from tertiary care hospitals.

Primary malignant melanoma of the oral cavity. A review of 20 cases.

Twenty patients with primary malignant melanoma of the oral cavity have been described. They formed 3.9 percent of the total number of patients with malignant neoplasms of the oral cavity.

Foreign bodies in the orbit. Review of 20 cases.

The interdisciplinary problem of foreign bodies in the orbit is presented on the basis of personal experience in the treatment of 20 patients. These foreign bodies often cause severe injuries to the organ of sight and even threaten life. Early removal of a foreign body is technically easy, prevents infection and facilitates anatomical reconstruction of the damaged structures.

Alfentanil as an anesthetic induction agent--a comparison with thiopental-lidocaine.

Alfentanil (0.175 mg/kg) and a combination of thiopental (3-4 mg/kg) and lidocaine (1.5 mg/kg) during anesthetic induction were compared.

NMR in experimental cerebral edema: value of T1 and T2 calculations.

In an experimental investigation, the efficacy of nuclear magnetic resonance (NMR) relaxation times in measuring brain water was studied. Cerebral edema was induced in four dogs with a freeze lesion, which was produced by contact with a steel cylinder cooled in liquid nitrogen and placed on the exposed dural surface of the brain. NMR proton imaging was performed 2, 3, 6, or 24 hr after production of the lesion, at a field strength of 0.

ED50 of alfentanil for induction of anesthesia in unpremedicated young adults.

This study determined the ED50 and ED90 of alfentanil for unconsciousness and anesthesia. A bolus of alfentanil was given to 28 healthy unpremedicated adults undergoing gynecologic or orthopedic procedures in one of four dosages: 100, 150, 200, or 250 micrograms/kg. Three indicators of induction were assessed 90 s later: eyelid reflex, response to verbal commands to breathe, and response to placement of a nasopharyngeal airway.

Proton nuclear magnetic resonance spectroscopy of normal and edematous brain tissue in vitro: changes in relaxation during tissue storage.

Proton nuclear magnetic resonance relaxation times, T1 and T2, of water in unfixed gray and white matter from normal and edematous rabbit brain tissues were measured in vitro at 23 degrees C and 100 MHz to evaluate the effects of the temperature (-25 degrees C to 37 degrees C) and duration (0 to 96 h) of tissue storage on relaxation times. T1 and T2 tended to decrease during storage, probably from slow dehydration of the tissue. This effect was greatest in tissues stored at 37 degrees C and least in those stored at 4 and -25 degrees C; decreases in T1 and T2 were greater in white matter than in gray matter.

Recovery of neuromuscular function in the perfused rat diaphragm after succinylcholine and pancuronium blockade.

The recovery of the rat diaphragm from neuromuscular blockade was studied in order to separate the contributions of drug binding and tissue washout. The in vitro rat diaphragm preparation was perfused with a cholinesterase-free solution via the phrenic vein and stimulated electrically via the phrenic nerve. Muscle paralysis was induced by infusion of a depolarizing blocker succinylcholine or by the nondepolarizing blocker pancuronium.

Pancuronium, unlike other nondepolarizing relaxants, retains potency at hypothermia.

The authors studied the pharmacodynamics of four nondepolarising relaxants, d-tubocurarine (dTC), pancuronium, metocurine, and gallamine, at 25 degrees C, 31 degrees C, and 37 degrees C. The rat phrenic nerve-hemidiaphragm preparation with vascular perfusion was used for these investigations. For each drug at each temperature, a dose-response curve for twitch depression was constructed.