Polyethyleneimine as a transmembrane carrier of fluorescently labeled proteins and antibodies.

Polyethyleneimine (PEI) has been used previously as a nonviral DNA transfer vector. In this article, we demonstrate its use as a vehicle for transmembrane delivery of proteins in cell culture conditions. Linking proteins to PEI required no other treatment beyond mixing them with PEI. The bond between PEI and protein combined at optimal ratios was maintained in electrophoresis, even in the presence of 2.5% sodium dodecyl sulfate (SDS). The optimal time for delivery of proteins was determined to be 24 h. We have successfully delivered an Alexa 488-labeled avidin protein into human glioblastoma cells. A functional antibody against the nuclear protein lamin was delivered into human fibroblasts and reacted with lamin inside live cells. PEI-based delivery of antibodies and fluorescently labeled proteins can be used for fluorescent detection, tracking, and evaluation of cellular protein function in vivo.

Transient speech compromise following sublabial transsphenoidal surgery: a case report and findings of a small preliminary study.

Sublabial transsphenoidal surgical removal of pituitary tumors is a common procedure with minimal complications. Although many investigators have reported oral sensory compromises following surgery, none has reported any postoperative compromise in speaking ability. In this article, we describe the case of a 33-year-old woman who developed transient but severe speech symptoms after she underwent sublabial transsphenoidal surgery. This case prompted us to undertake a brief retrospective analysis of our experience with this procedure in other patients, which revealed that speech compromise is far more common than heretofore realized.

Human and behavioral factors contributing to spine-based neurological cockpit injuries in pilots of high-performance aircraft: recommendations for management and prevention.

In high-performance aircraft, the need for total environmental awareness coupled with high-g loading (often with abrupt onset) creates a predilection for cervical spine injury while the pilot is performing routine movements within the cockpit. In this study, the prevalence and severity of cervical spine injury are assessed via a modified cross-sectional survey of pilots of multiple aircraft types (T-38 and F-14, F-16, and F/A-18 fighters). Ninety-five surveys were administered, with 58 full responses. Fifty percent of all pilots reported in-flight or immediate post-flight spine-based pain, and 90% of fighter pilots reported at least one event, most commonly (> 90%) occurring during high-g (> 5 g) turns of the aircraft with the head deviated from the anatomical neutral position. Pre-flight stretching was not associated with a statistically significant reduction in neck pain episodes in this evaluation, whereas a regular weight training program in the F/A-18 group approached a significant reduction (mean = 2.492; p < 0.064). Different cockpit ergonomics may vary the predisposition to cervical injury from airframe to airframe. Several strategies for prevention are possible from both an aircraft design and a preventive medicine standpoint. Countermeasure strategies against spine injury in pilots of high-performance aircraft require additional research, so that future aircraft will not be limited by the human in control.

Brain choline acetyltransferase and mental function in Alzheimer disease.

OBJECTIVE: To determine whether higher brain levels of choline acetyltransferase (ChAT) are associated with improved neuropsychological function in patients with Alzheimer disease (AD). DESIGN: Case series with single-blind post hoc analysis of biopsy specimens. SETTING: Urban hospital and medical school. PATIENTS: A consecutive sample of 8 patients with AD undergoing brain biopsy and surgical implantation of intraventricular pumps for administration of potential chemotherapeutic agents. INTERVENTIONS: Brain biopsy, surgical implantation of intraventricular pumps, and, in 1 patient, ventriculoperitoneal shunt placement. MAIN OUTCOME MEASURES: All patients underwent neuropsychological testing no more than 2 weeks before surgical biopsy. Levels of ChAT were determined in fresh brain tissue from biopsy samples. RESULTS: Significant positive correlations were found between ChAT levels and 2 neuropsychological test scores, Mini-Mental State Examination and the Logical Memory subtest of the Wechsler Memory Scale. CONCLUSION: Degeneration of the cholinergic system in vivo correlates with decreasing cognitive function in patients with AD.

Suppression of post-ischemic-induced fos protein expression by an antisense oligonucleotide to c-fos mRNA leads to increased tissue damage.

Activation of c-fos, an immediate early gene, and the subsequent upregulation of Fos protein expression occur following neural injury, including focal cerebral ischemia (fci). Fos and Jun form a heterodimer known as activator protein 1, which regulates the expression of many late effector genes. To study the downstream effects of c-fos expression following ischemia, we suppressed the translation of c-fos by administering an antisense oligonucleotide (AO) to c-fos mRNA. Eighteen hours prior to fci, male, Long Evans (LE) rats received intraventricular injections of AO, mismatched AO (MS) or artificial cerebrospinal fluid (aCSF). Fci was induced by permanent right middle cerebral artery occlusion. At 24-h post-occlusion, neurological function was assessed, and the animals were sacrificed. The brains were removed and stained with triphenyltetrazolium chloride for infarct volume determination. Fos immunohistochemistry was performed in separate animals to determine the effects of treatment on Fos expression number of Fos positive cells. AO administration reduced the number of cells with fci-induced Fos expression by approximately 75%. No differences in neurological scores existed between any of the groups. AO-treated LE developed larger infarcts (40.1+/-1.0%, mean+/-S.D., p<0.001) than MS- or aCSF-treated controls (34.3+/-1.0%, 34.6+/-1.0%, respectively). These results suggest that c-fos activation and subsequent Fos protein expression exerts a neuroprotective effect, which is likely via upregulation of neurotrophins, following focal cerebral ischemia. This response, among others, may contribute to brain adaptation to injury that underlies functional recovery after stroke.

Cloning and characterization of CRF, a novel C1q-related factor, expressed in areas of the brain involved in motor function.

We have isolated and characterized a novel cDNA, C1q-Related Factor (CRF), that is predicted to encode a 258 amino acid polypeptide with a hydrophobic signal sequence, a collagenous region, and a globular domain at the carboxy terminus that shares homology to the C1q signature domain. Human CRF transcript is expressed at highest levels in the brain, particularly in the brainstem. In situ hybridization to mouse brain sections demonstrated that CRF transcripts are most abundant in areas of the nervous system involved in motor function, such as the Purkinje cells of the cerebellum, the accessory olivary nucleus, the pons and the red nucleus. The mouse CRF homolog is highly similar to the human gene at both the nucleotide and protein level, suggesting an important conserved role for this protein.

Pituitary adenoma in children.

Pituitary adenoma is an uncommon intracranial tumor of children. The authors retrospectively reviewed the records of 10 patients younger than 17 years of age with pituitary adenoma. Five patients had visual loss at presentation. Four of these five patients with visual loss and extrasellar tumor extension were adolescents (12-15 years of age). Seven of 10 patients underwent neurosurgery. Of the five patients with visual loss, three patients experienced visual improvement, one patient was unchanged, and one patient did not have follow-up. The visual loss in these patients tended to be more severe and more likely to be associated with optic atrophy than adult patients. Although they are relatively uncommon, ophthalmologists should be aware that pituitary adenomas may occur in children and that these tumors when present in the pubertal period may be more likely to exhibit extrasellar extension or invasiveness.

Penetration of dynorphin 1-13 across the blood-brain barrier.

Previous studies have demonstrated neuroprotective effects of the opioid peptide dynorphin (dyn) 1-13 in focal cerebral ischemia. The passage of dyn 1-13 across the blood-brain barrier (BBB) was studied by a modification of the Oldendorf technique in the normal rat and cat, as well as in a feline model of experimentally induced focal cerebral ischemia. In the rat, dyn 1-13 penetration of the BBB could not be detected by this technique, even in the presence of peptidase inhibitors. In contrast, dyn 1-13 did cross the BBB into the normal cat hippocampus, cortex and cerebellum. The passage of dyn 1-13 across the BBB was greater in cats with experimentally induced focal cerebral ischemia. Some of the tritium-labeled material which crossed the BBB was confirmed by high performance liquid chromatography to be dyn 1-13. These studies support the hypothesis that the therapeutic effects observed after the peripheral administration of dyn 1-13 to cats with focal cerebral ischemia can be produced by a central mechanism of action.

Effects of halothane, alpha-chloralose, and pCO2 on injury volume and CSF beta-endorphin levels in focal cerebral ischemia.

Anesthetic agent, arterial pCO2 level, and opioid peptides have all been implicated in the pathophysiology of experimental stroke models. The effects of halothane, alpha-chloralose, and differing concentrations of arterial pCO2 on injury volume and CSF beta-endorphin levels were studied in a feline model of experimental focal cerebral ischemia. The type of anesthetic agent used had no effect on injury volume following 6 h of focal cerebral ischemia. Over a 6-h period, beta-endorphin levels significantly increased from 10.1 +/- 5.0 fmol/mL at zero time to 14.4 +/- 7.2 fmol/mL at 6 h under halothane anesthesia (p < 0.05), whereas they did not significantly change (10.1 +/- 6.7 to 7.8 +/- 4.7 fmol/mL) under alpha-chloralose anesthesia. In contrast, hypercapnia had no effect on beta-endorphin levels, but significantly increased injury volume from 30.6 +/- 5.7% of the ipsilateral hemisphere under normocapnic conditions to 37.1 +/- 5.9% under hypercapnic conditions (p < 0.05). These results suggest that hypercapnia increases injury volume in a feline model of focal cerebral ischemia, and pCO2 should be controlled in experimental focal cerebral ischemia models.

Time-dependent variability of infarct size and hemispheric volume in experimental focal cerebral ischemia in the rabbit.

Studies measuring the volume of infarcted tissue and survival after pharmacologic intervention in stroke are complicated by the potential effect of survival time on infarct volume. In this study, the volume of infarcted tissue as defined by 2,3,5-triphenyltetrazolium chloride staining was determined in rabbits at 28 h, 7 days, and 3 weeks after permanent middle cerebral artery occlusion. Compared to values at 28 h, infarcted tissue volume did not change at 7 days after occlusion, but decreased significantly by three weeks after occlusion (p < 0.01). Infarcted tissue volume expressed as a percent of hemispheric volume did not significantly change at either timepoint (p < 0.08). Immunocytochemical staining for glial fibrillary acidic protein (GFAP) indicated that infarct volume changes were not due to glial infiltration. Total hemispheric volume decreased by 7 days (p < 0.01) and 3 weeks (p < 0.01) after occlusion. These results suggest that changes in hemispheric volume may confound comparison of injury volumes in animals at differing times after occlusion. In experiments where drug treatments increase survival after focal cerebral ischemia, comparisons of the absolute infarct volume may not be valid if drug-treated animals survive greater than 1 week and untreated animals do not.

Brown-Sequard syndrome produced by cervical disc herniation: case report and literature review.

BACKGROUND: The Brown-Sequard Syndrome is most commonly described in conjunction with a traumatic injury to the spinal cord. the condition involves ipsilateral loss of motor function, proprioception, and vibratory sensation, combined with contralateral loss of pain and temperature sensation. CASE REPORT: A 56 year-old female developed left thigh discomfort and numbness. Over the next five months, this spread to involve her left leg and chest to the axilla. Physical examination revealed myelopathy. Also present were motor, proprioceptive, and vibratory deficits in the right leg. A left sensory level to T2 was present. An MRI scan showed a large right cervical herniated disc with unilateral spinal cord compression. Following anterior cervical discectomy and fusion, the patient's symptoms have steadily improved. CONCLUSIONS: The Brown-Sequard Syndrome can be caused by a herniated cervical disc. MRI scans should be employed early in the diagnostic evaluation of such patients, particularly in the absence of penetrating trauma or other obvious causes of the syndrome.

Fatal subarachnoid hemorrhage from the rupture of a totally intracavernous carotid artery aneurysm: case report.

Intracavernous carotid artery aneurysms usually cause symptoms because of gradual expansion without rupture. Most such aneurysms that do rupture lead to a carotid-cavernous fistula. Very few cases of rupture leading to subarachnoid hemorrhage have been reported. We report a case in which rupture of an entirely intracavernous carotid artery aneurysm led to death from a massive subarachnoid hemorrhage.

Evaluation of delayed treatment of focal cerebral ischemia with three selective kappa-opioid agonists in cats.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the therapeutic efficacy of three kappa-opioid agonists used for delayed treatment of experimental focal cerebral ischemia. METHODS: Forty halothane-anesthetized cats underwent permanent occlusion of the right intracranial internal carotid, middle cerebral, and anterior cerebral arteries via a transorbital, microsurgical approach. Six hours after occlusion, animals received a blinded bolus injection, and a subcutaneous osmotic pump was implanted to provide continuous release for 7 days. The injection and pump contained either saline or one of three kappa-agonists: dynorphin (1-13), U-50,488, or DuP E3800. Survival, neurological function, tissue damage, and brain weight were assessed. RESULTS: As a group, kappa-agonist-treated animals had higher survival (P < .02), less tissue damage (P < .02), and lower brain weight (P < .05) than saline controls. U-50,488 more effectively improved survival (P < .03) than dynorphin (P < .07) or E3800 (P < .07). Each of the three kappa compounds improved tissue damage (dynorphin, P < .02; U-50,488, P < .05; E3800, P < .05). Greater improvement in neurological function was seen after treatment with dynorphin (P < .05) than with U-50,488 (P < .6) or E3800 (P < .7). The only significant reduction in brain weight was seen after dynorphin treatment (P < .01). CONCLUSIONS: Compounds that act at the kappa subclass of opiate receptors are effective in increasing survival, improving neurological function, and decreasing tissue damage and edema in a cat model of focal cerebral ischemia. The current study provides support for the benefits of treatment of acute cerebrovascular ischemia with kappa-opioid agonists. The agents may prove to be of superior clinical utility because of efficacy even when administered 6 hours after the onset of stroke.

Scalp hibernoma: case report and literature review.

Hibernomas are uncommon, benign neoplasms derived from the remnants of fetal brown adipose tissue. A review of the world literature revealed 105 cases, with the interscapular location the most common. Typically, hibernomas are asymptomatic and slow-growing. Adequate treatment usually consists of simple excision. We describe the second documented case of a scalp hibernoma.

U50488 reduces the severity of tissue damage in a rabbit model of focal cerebral ischemia.

Many pharmacotherapies for stroke that have been successful in the laboratory have proven to be ineffective in the clinical setting, often because patients do not arrive for treatment until hours after the onset of the ischemic insult. Kappa opioid treatment of cerebral ischemia has been successful in the cat and mouse with treatment delays of up to 6 h. The purpose of the present study was to develop a model of delayed kappa opioid treatment of cerebral ischemia in the rabbit. Fourteen rabbits underwent permanent, unilateral occlusion of the internal carotid, middle cerebral, and anterior cerebral arteries via a transorbital, microsurgical approach. At 6 h postocclusion, animals received a blinded bolus injection and continuous infusion of either saline or the kappa agonist, U50488. Survival was not improved after U50488 treatment. U50488 treatment did, however, reduce areas of severe tissue damage and increase areas of modest tissue damage. This suggests U50488 arrested the progression of damage from noninfarcted to fully infarcted tissue. The present results show beneficial effects of delayed treatment with kappa agonists in a species similar in vasculature to humans, and much less costly than primates or cats.

Development of a model for Parkinson's disease in sheep using unilateral intracarotid injection of MPTP via slow continuous infusion.

The effects of unilateral intracarotid administration of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) in sheep were studied with the goal of producing a non-primate, large animal model of Parkinson's Disease. Adult female sheep were given an acute (over 30 min) or chronic (over 1 week) injection of MPTP (0.4-5.0 mg/kg) via the common carotid artery. Both methods produced parkinsonian-like behavior. Turning contralateral to the side of injection was induced by apomorphine (APO) in both groups. However, amphetamine (AMP) induced ipsilateral turning only in the chronic treatment group. Acute and chronic MPTP treatment resulted in a loss of substantia nigra tyrosine hydroxylase immunoreactive (THIR) neurons with a significantly greater loss ipsilateral to the injection in each treatment group (acute p < 0.05; chronic p < 0.01). Caudate dopamine (DA) was depleted in both treatment groups, although the difference between ipsilateral and contralateral DA content was significant only in the chronic treatment group (p < 0.05). The best results were seen in those animals with chronic infusion with the occipital artery occluded to prevent entry of drug into the posterior circulation with subsequent bilateral distribution. Use of slow and continuous intracarotid administration of MPTP with the ipsilateral occipital artery occluded can prevent some of the bilateral effects of acute treatment, and results in statistically significant ipsilateral reduction of THIR neurons in the substantia nigra and reduction of tissue levels of DA in the caudate nucleus. Such treatment produces appropriate turning responses to both AMP and APO challenge not seen in the acute treatment group, and appears to be an effective method of producing parkinsonian-like behavior in a large animal.

Treatment of secretory pituitary adenoma with radiation therapy.

A retrospective review of 44 patients with secretory pituitary adenoma treated with radiation therapy (median total dose of 4,500 cGy with a median fraction size of 225 cGy) was performed to analyze response rates and possible variables associated with failure to respond and with complications. The treatment technique used for 75% of the patients was a combination field; an opposed-lateral fields technique was used for the remainder. Median follow-up was 78.5 months, with 59% followed up for more than 60 months and 34% for more than 120 months. Overall survival was 90%, and disease-free survival was 62%. Response rates were 86% for the group with prolactinoma, 67% for the group with acromegaly, and 50% for the group with Cushing disease; the overall response rate was 71%. Findings of suprasellar extension and those from treatment with opposed-lateral fields correlated significantly with failure to respond. A higher percentage of patients with invasive macroadenomas also failed to respond. More complications were found in patients treated with opposed-lateral fields, but the numbers were too small to reach significance. Radiation therapy remains an important adjunct for the treatment of many patients with secretory pituitary adenoma.

The effect of long-term high-dose naloxone infusion in experimental blunt spinal cord injury.

The effect of long-term continuous subcutaneous infusion of naloxone on blunt spinal cord injury in the rat was assessed using four tests of neurological function, seven histological categories, and two electrophysiological measures. All four neurological function tests showed a trend toward improvement in naloxone-treated animals: the degree of improvement was statistically significant in two of the four categories. A significant reduction in myelin sheath edema was found in the naloxone-treated animals. Although there was a decrease in corticomotor-evoked potentials complexity following injury, there was no significant difference in naloxone-treated animals. Somatosensory-evoked potentials were significantly increased in amplitude and latency in naloxone-treated animals. This increase was most apparent at 60 min: no difference was found by 3 weeks postinjury. These results confirm earlier reports that naloxone can ameliorate the functional neurological deficits of spinal cord injury. Naloxone also produces alterations in the somatosensory-evoked responses in the early phase of treatment and significantly reduces myelin sheath edema.

Variations in corticomotor and somatosensory evoked potentials: effects of temperature, halothane anesthesia, and arterial partial pressure of CO2.

The effects of temperature, halothane concentration, and arterial partial pressure of CO2 on corticomotor evoked potentials (CMEPs) and somatosensory evoked potentials (SSEPs) were studied. Hypothermia causes an increase in CMEP and SSEP latencies. Corticomotor evoked potential amplitude increases with hypothermia to reach a maximum at or below 28 degrees C. As the temperature decreases from 42 degrees C, SSEP amplitude initially increases to reach a maximum between 36 and 34 degrees C and then decreases with further reductions in temperature. Increased arterial partial pressure of CO2 decreases amplitude and increases latencies of the CMEPs and SSEPs. The concentration of halothane has no effect on CMEP amplitude or latency. However, SSEP amplitude is inversely related to halothane concentration, and SSEP latency is directly related to halothane concentration. These results suggest that physiologic variables must be carefully measured when evoked potentials are utilized in any animal or human study. Moreover, each type of evoked potential has a unique response to alterations of these variables.