Cortical edema in moderate fluid percussion brain injury is attenuated by vagus nerve stimulation.

Development of cerebral edema (intracellular and/or extracellular water accumulation) following traumatic brain injury contributes to mortality and morbidity that accompanies brain injury. Chronic intermittent vagus nerve stimulation (VNS) initiated at either 2 h or 24 h (VNS: 30 s train of 0.5 mA, 20 Hz, biphasic pulses every 30 min) following traumatic brain injury enhances recovery of motor and cognitive function in rats in the weeks following brain injury; however, the mechanisms of facilitated recovery are unknown. The present study examines the effects of VNS on development of acute cerebral edema following unilateral fluid percussion brain injury (FPI) in rats, concomitant with assessment of their behavioral recovery. Two hours following FPI, VNS was initiated. Behavioral testing, using both beam walk and locomotor placing tasks, was conducted at 1 and 2 days following FPI. Edema was measured 48 h post-FPI by the customary method of region-specific brain weights before and after complete dehydration. Results of this study replicated that VNS initiated at 2 h after FPI: 1) effectively facilitated the recovery of vestibulomotor function at 2 days after FPI assessed by beam walk performance (P<0.01); and 2) tended to improve locomotor placing performance at the same time point (P=0.18). Most interestingly, results of this study showed that development of edema within the cerebral cortex ipsilateral to FPI was significantly attenuated at 48 h in FPI rats receiving VNS compared with non-VNS FPI rats (P<0.04). Finally, a correlation analysis between beam walk performance and cerebral edema following FPI revealed a significant inverse correlation between behavior performance and cerebral edema. Together, these results suggest that VNS facilitation of motor recovery following experimental brain injury in rats is associated with VNS-mediated attenuation of cerebral edema.

Comparative fos immunoreactivity in the brain after forebrain, brainstem, or combined seizures induced by electroshock, pentylenetetrazol, focally induced and audiogenic seizures in rats.

To help discern sites of focal activation during seizures of different phenotype, the numbers of Fos immunoreactive (FI) neurons in specific brain regions were analyzed following "brainstem-evoked," "forebrain-evoked" and forebrain/brainstem combination seizures induced by a variety of methods. First, pentylenetetrazol (PTZ, 50 mg/kg) induced forebrain-type seizures in some rats, or forebrain seizures that progressed to tonic/clonic brainstem-type seizures in other rats. Second, minimal electroshock induced forebrain seizures whereas maximal electroshock (MES) induced tonic brainstem-type seizures in rats. Third, forebrain seizures were induced in genetically epilepsy-prone rats (GEPRs) by microinfusion of bicuculline into the area tempestas (AT), while brainstem seizures in GEPRs were induced by audiogenic stimulation. A final set was included in which AT bicuculline-induced forebrain seizures in GEPRs were transiently interrupted by audiogenic seizures (AGS) in the same animals. These animals exhibited a sequence combination of forebrain clonic seizure, brainstem tonic seizure and back to forebrain clonic seizures. Irrespective of the methods of induction, clonic forebrain- and tonic/clonic brainstem-type seizures were associated with considerable Fos immunoreactivity in several forebrain structures. Tonic/clonic brainstem seizures, irrespective of the methods of induction, were also associated with FI in consistent brainstem regions. Thus, based on Fos numerical densities (FND, numbers of Fos-stained profiles), forebrain structures appear to be highly activated during both forebrain and brainstem seizures; however, facial and forelimb clonus characteristic of forebrain seizures are not observable during a brainstem seizure. This observation suggests that forebrain-seizure behaviors may be behaviorally masked during the more severe tonic brainstem seizures induced either by MES, PTZ or AGS in GEPRs. This suggestion was corroborated using the sequential seizure paradigm. Similar to findings using MES and PTZ, forebrain regions activated by AT bicuculline were similar to those activated by AGS in the GEPR. However, in the combination seizure group, those areas that showed increased FND in the forebrain showed even greater FND in the combination trial. Likewise, those areas of the brainstem showing FI in the AGS model, showed an even greater effect in the combination paradigm. Finally, the medial amygdala, ventral hypothalamus and cortices of the inferior colliculi showed markedly increased FND that appeared dependent upon activation of both forebrain and brainstem seizure activity in the same animal. These findings suggest these latter areas may be transitional areas between forebrain and brainstem seizure interactions. Collectively, these data illustrate a generally consistent pattern of forebrain Fos staining associated with forebrain-type seizures and a consistent pattern of brainstem Fos staining associated with brainstem-type seizures. Additionally, these data are consistent with a notion that separate seizure circuitries in the forebrain and brainstem mutually interact to facilitate one another, possibly through involvement of specific "transition mediating" nuclei.

Elevated tumor lactate concentrations predict for an increased risk of metastases in head-and-neck cancer.

PURPOSE: Hypoxia shifts the balance of cellular energy production toward glycolysis with lactate generation as a by-product. Quantitative bioluminescence imaging allows for the quantitation of lactate concentrations in individual tumors. We assessed the relationship between pretreatment tumor lactate concentrations and subsequent development of metastatic disease in patients with newly diagnosed head-and-neck cancer. METHODS AND MATERIALS: At the time of biopsy of the primary site, a separate specimen was taken and flash-frozen for subsequent quantitation of lactate concentration using a luciferase bioluminescence technique. The two-dimensional spatial distribution of the bioluminescence intensity within the tissue section was registered directly using a microscope and an imaging photon counting system. Photon intensity was converted to distributions of volume-related tissue concentrations (micromol per gram wet weight). Treatment consisted of either surgery and postoperative radiotherapy or primary radiotherapy, based on presenting disease stage and institutional treatment policies. The subsequent development of metastatic disease constituted the primary clinical endpoint. RESULTS: Biopsies obtained from 40 patients were evaluable in 34. The larynx was the most frequent primary site (n = 25). Other sites included oropharynx (n = 5), hypopharynx (n = 3), and oral cavity (n = 1). Most patients (74%) presented with an advanced stage T3 or T4 primary tumor. Nodal involvement was present in 19 (54%) patients. The median tumor lactate concentration was 7.1 micromol/g. Tumors were classified as having either low or high lactate concentrations according to whether these values were below or above the median. The median follow-up time for surviving patients is 27 months. Two-year actuarial survival was 90% for patients with low-lactate-concentration tumor vs. 35% for patients with high-lactate-concentration primaries (<0.0001). Two-year metastasis-free survival was adversely influenced by high tumor lactate concentrations (90% vs. 25%, p < 0.0001). The median lactate concentration for tumors that subsequently metastasized was 12.9 micromol/g vs. 4.8 micromol/g for patients who remained continuously free of disease (p < 0.005). Lactate concentration was not correlated with presenting T stage or N stage. DISCUSSION: Elevated tumor lactate concentrations are associated with the subsequent development of nodal or distant metastases in head-and-neck cancer patients. This more aggressive malignant phenotype is probably associated with hypoxia-mediated radioresistance and the upregulation of metastasis-associated genes.

Acute urinary toxicity following transperineal prostate brachytherapy using a modified Quimby loading method.

PURPOSE: To examine the acute urinary toxicity following transperineal prostate implant using a modified Quimby loading method with regard to time course, severity, and factors that may be associated with a higher incidence of morbidity. METHODS AND MATERIALS: One hundred thirty-nine patients with prostate adenocarcinoma treated with brachytherapy from 1997 through 1999 had follow-up records available for review. Patients considered for definitive brachytherapy alone included those with prostate specific antigen (PSA) < or = 6, Gleason score (GS) < or = 6, clinical stage < T2b, and prostate volumes generally less than 40 cc. Patients with larger prostate volumes were given neoadjuvant antiandrogen therapy. Those with GS > 6, PSA > 6, or Stage > T2a were treated with external beam radiation therapy followed by brachytherapy boost. Sources were loaded according to a modified Quimby method. At each follow-up, toxicity was graded based on a modified RTOG urinary toxicity scale. RESULTS: Acute urinary toxicity occurred in 88%. Grade I toxicity was reported in 23%, grade II in 45%, and grade III in 20%, with 14% requiring prolonged (greater than 1 week) intermittent or indwelling catheterization. Overall median duration of symptoms was 12 months. There was no difference in duration of symptoms between patients treated with I-125 or Pd-103 sources (p = 0.71). After adjusting for GS and PSA, multivariate logistic regression analysis showed higher incidence of grade 3 toxicity in patients with larger prostate volumes (p = 0.002), and those with more seeds implanted (p < 0.001). Higher incidence of prolonged catheterization was found in patients receiving brachytherapy alone (p = 0.01), with larger prostate volumes (p = 0.01), and those with more seeds implanted (p < 0.001). CONCLUSION: Interstitial brachytherapy for prostate cancer leads to a high incidence of acute urinary toxicity, most of which is mild to moderate in severity. A prolonged need for catheterization can occur in some patients. Patients receiving brachytherapy alone, those with prostate volumes greater than 30 cc, and those implanted with a greater number of seeds have the highest incidence of significant toxicity.

73.6 Gy and beyond: hyperfractionated, accelerated radiotherapy for non-small-cell lung cancer.

PURPOSE: To assess results with twice-daily high-dose radiotherapy (RT) for non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Between 1991 and 1998, 94 patients with unresectable NSCLC were prescribed > or = 73.6 Gy via accelerated fractionation. Fifty were on a phase II protocol (P group); 44 were similarly treated off-protocol (NP group). The clinical target volume received 45 Gy at 1.25 Gy bid (6-hour interval). The gross target volume received 1.6 Gy bid to 73.6 to 80 Gy over 4.5 to 5 weeks using a concurrent boost technique. Overall survival (OS) and local progression-free survival (LPFS) were calculated by the Kaplan-Meier method. Median follow-up durations for surviving P and NP patients were 67 and 16 months, respectively. RESULTS: Total doses received were > or = 72 Gy in 97% of patients. The median OS by stage was 34, 13, and 12 months for stages I/II, IIIa, and IIIb, respectively. LPFS was significantly longer for patients with T1 lesions (median, 43 months) versus T2-4 (median, 7 to 10 months; P =.01). Results were similar in the P and NP groups. Acute grade > or = 3 toxicity included esophagus (14 patients; 15%), lung (three patients; 3% [one grade 5]), and skin (four patients; 4%). Grade > or = 3 late toxicity in 86 assessable patients included esophagus (three patients; 3%), lung (15 patients; 17% [three grade 5]), skin (five patients; 6%), heart (two patients; 2%), and nerve (one patient; 1%). CONCLUSION: This regimen yielded favorable survival results, particularly for T1 lesions. Acute grade > or = 3 toxicity seems greater than for conventional RT, though most patients recovered. Late grade > or = 3 pulmonary toxicity occurred in 17%. Because of continued locoregional recurrences, we are currently using doses > or = 86 Gy.

Radiation dose selection in Hodgkin's disease patients with large mediastinal adenopathy treated with combined modality therapy.

PURPOSE: To determine the effective dose of consolidation radiation in Hodgkin's disease (HD) patients with large mediastinal adenopathy (LMA) treated with combined modality therapy (CMT). METHODS AND MATERIALS: Eighty-three HD patients with LMA receiving CMT between 1983 and 1997 at Duke University and Yale University were identified. Patients underwent complete clinical staging. The staging breakdown was: IA, 4 patients; IB, 1 patient; IIA, 25 patients; IIB, 33 patients; IIIA, 3 patients; IIIB-6 patients; IVA, 2 patients; and IVB, 9 patients. All patients received induction chemotherapy (CT) as follows: MOPP/ABV(D), 31 patients; BCVPP, 15 patients; ABVD, 24 patients; MOPP, 3 patients; and other regimens, 10 patients. Following 6 cycles of CT, patients were restaged and classified as having either complete response (CR) or induction failure (IF). Post-CT gallium scans were obtained in 52 patients. Patients with residual radiographic abnormalities were classified as having CR if they were gallium-negative and clinically well otherwise. Following induction CT, 78 patients had a CR. There were 5 IFs. Consolidation irradiation was administered to all sites of initial involvement in patients who had achieved CR. RT dose varied. Patients were grouped into the following dose ranges: < or = 20 Gy, 12 patients; 20-25 Gy, 24 patients; 25-30 Gy, 30 patients; > or = 30 Gy, 12 patients. RESULTS: Overall survival and failure-free survival were both 76% at 10 years. Of the 78 CR patients, 15 failed. Patterns of failure were in-field alone, 8 patients; out of field alone, 2 patients; and combined, 5 patients. Failure patterns by RT dose were: < or = 20 Gy, 0/12; 20-25 Gy, 7/24; 25-30 Gy, 5/30; > or = 30 Gy, 3/11. There was no apparent correlation between RT dose and subsequent failure. Post chemotherapy gallium scans were helpful in predicting for failure. Of 48 patients in whom the gallium was negative after chemotherapy, there were 6 failures, compared with 9 failures among 30 patients in whom gallium was not done after chemotherapy (p = 0.066). Additionally, patients receiving adriamycin-based chemotherapy regimens had improved outcomes compared to those not receiving adriamycin (p = 0.03.) CONCLUSIONS: These retrospective data suggest that low-dose radiotherapy following CR achieved with induction chemotherapy (particularly when documented with gallium scanning) may be as effective as higher doses for bulky HD at presentation. Phase III trials are necessary for confirmation of this hypothesis.

Fos expression and 2-deoxyglucose uptake following seizures in developing genetically epilepsy-prone rats.

Juvenile genetically epilepsy-prone rats (GEPR)-3s display one of three types of seizures in response to sound: a typical class 3 seizure consisting of an explosive running/bouncing episode followed by a clonic seizure (audiogenic response score, ARS-3); an ARS-3 seizure followed by a forebrain seizure that includes facial and forelimb (F&F) clonus with rearing (ARS-3f); or, a running/bouncing episode followed by a severe tonic seizure with complete hindlimb extension (ARS-9) not accompanied with subsequent F&F clonus. The adult seizure phenotype, manifest in all GEPR-3s by age 45 days of age, consists of an ARS-3 not followed by F&F clonus or tonic extension. The present studies sought to determine the neuronal networks activated during these various developmental convulsive patterns by examining anatomical patterns of [(14)C]2-deoxyglucose (2-DG) uptake or immediate-early-gene (Fos) expression subsequent to seizures. Many, but not all, brain areas of control rats showed age-related increases in Fos expression in response to the acoustic stimulation. An age effect was not observed in 2-DG uptake. In GEPRs, the profiles of Fos expression and 2-DG uptake following seizures were often parallel; however, there were notable exceptions. For example, increased 2-DG uptake in the cochlear nuclei, central region of the inferior colliculi, and the substantia nigra were not accompanied by increased Fos expression in these areas regardless of the seizure phenotypes. Reciprocally, other regions, particularly in the amygdala, ventromedial hypothalamus and parabrachial areas, displayed intense seizure related Fos labeling without detectable increases in 2-DG uptake. Fos and 2-DG uptake patterns in response to acoustic stimulation varied according to brain region, seizure phenotype and severity. In general, the degree of 2-DG uptake correlated with seizure severity. For example, the ARS-9 seizures, being the most intense, resulted in significant increases in 2-DG uptake in almost all brain regions examined. 2-DG uptake following the ARS-3f and ARS-3 seizures, although increased, did not reach statistical significance in most brain areas. In contrast to the 2-DG findings, a seizure-severity dependent effect was not seen with Fos. Rather, the induction of Fos associated with acoustic stimulation and seizure was more associated with age and seizure-phenotype. Thus, the developmental profiles of Fos expression and 2-DG uptake in response to seizures are distinctly different and concurrent examination of both markers is useful in the identification of brain circuitry involved in seizure development.

Plasma transforming growth factor-beta1 level before radiotherapy correlates with long term outcome of patients with lung carcinoma.

BACKGROUND: Plasma transforming growth factor-beta1 (TGFbeta1) levels are increased in many malignancies at the time of diagnosis, including all forms of lung carcinoma. Therefore, the potential use of TGFbeta1 as a plasma marker to predict the long term outcome of lung carcinoma patients treated with radiotherapy (RT) was evaluated. METHODS: Plasma samples for 59 newly diagnosed lung carcinoma patients were assayed for TGFbeta1 before RT (pre RT), at the end of RT (end RT), and during follow-up after RT. TGFbeta1 was extracted from plasma using an acid-ethanol method. An enzyme-linked immunoadsorbent assay was used to quantify the plasma TGFbeta1 levels. The normal value for this assay is < or =7.5 ng/mL. Disease status at last follow-up was without knowledge of TGFbeta1 levels. Comparisons within groups and between groups were estimated using analysis of variance and the Student t test for unpaired data, respectively. RESULTS: The 59 patients were divided into 2 groups according to their disease status at last follow-up: those with no evidence of disease (NED) (n = 13) and those with disease (WD) (n = 46). The median follow up was 26.8 months and 12.4 months, respectively, for the NED and WD groups. No significant differences were found in the clinical characteristics between the two groups. The plasma TGFbeta1 level before RT was significantly higher in the WD group (mean +/- standard error of the mean [SEM] = 12.5+/-1.7 ng/mL; median = 8.6 ng/mL) compared with the NED group (mean +/- SEM = 6.0+/-1.0 ng/mL; median = 6.0 ng/mL) (P = 0.037). At the time of last follow-up, WD patients had a significantly higher plasma TGFbeta1 level (mean +/- SEM = 11.6+/-1.3 ng/mL; median = 9.6 ng/mL) compared with NED patients (mean +/- SEM = 3.7+/-0.5 ng/mL; median = 3.6 ng/mL) (P = 0.002). CONCLUSIONS: These data demonstrate that plasma TGFbeta1 may be a useful tumor marker in patients with lung carcinoma.

Morphological deficits in noradrenergic neurons in GEPR-9s stem from abnormalities in both the locus coeruleus and its target tissues.

The epileptic condition of the genetically epilepsy-prone rat (GEPR) appears to be caused partially by deficiencies in the locus coeruleus (LC) innervation of the superior colliculus (SC). Previous studies provide quantitative documentation of noradrenergic morphological deficits in the moderately epileptic GEPR-3. The present findings extend these studies by applying cell culture methodology to assessments of the severely epileptic GEPR-9. Our data show that total neurite length, the number of neurite branch points per cell, the cross-sectional area of cell bodies, and the cell perimeter are deficient in noradrenergic neurons in LC + SC cocultures derived exclusively from GEPR-9s compared to analogous cocultures obtained solely from nonepileptic control rats. Partial restoration of LC neuron morphology toward normal occurs when the GEPR-9 SC component of the coculture is replaced with nonepileptic control SC. Finally, when the GEPR-9 SC is cocultured with the control LC, a partial morphological deficit occurs in the otherwise normal noradrenergic neurons. However, the magnitude of this deficit is less than that observed in noradrenergic neurons of the GEPR-9 LC cocultured with the control SC. These data support the hypothesis that the developmental deficiencies of noradrenergic neurons of the GEPR-9 are derived from two sources, the LC and its target tissue, in this case, the SC. Also, intrinsic abnormalities of the LC appear to make a more pronounced contribution to the noradrenergic deficits than do those which reside in the SC.

Oxygenation of head and neck cancer: changes during radiotherapy and impact on treatment outcome.

BACKGROUND AND PURPOSE: To evaluate the long term clinical significance of tumor oxygenation in a population of head and neck cancer patients receiving radiotherapy and to assess changes in tumor oxygenation during the course of treatment. METHODS AND MATERIALS: Patients with head and neck cancer receiving primary RT underwent pretreatment polarographic tumor oxygen measurement of the primary site or a metastatic neck lymph node. Treatment consisted of once daily (2 Gy/fraction to a total dose of 66-70 Gy) or twice daily irradiation (1.25 Gy/fraction to 70-75 Gy) to the primary site. Twenty-seven patients underwent a second series of measurements early in the course of irradiation. RESULTS: Sixty-three patients underwent pretreatment tumor oxygen assessment (primary site, n = 24; nodes, n = 39). The median pO2 for primary lesions was 4.8 mmHg, and it was 4.3 mmHg for cervical nodes. There was a weak association between anemia and more poorly oxygened tumors, but many non-anemic patients still had poorly oxygenated tumors. Repeat assessments of tumor oxygenation after 10-15 Gy were unchanged compared to pretreatment baselines. Poorly oxygenated nodes pretreatment were more likely to contain viable residual disease at post-radiation neck dissection. Median follow-up time for surviving patients was 20 months (range 3-50 months). Hypoxia (tumor median pO2 <10 mmHg) adversely affected 2 year local-regional control (30 vs. 73%, P = 0.01), disease-free survival (26 vs. 73%, P = 0.005), and survival (35 vs. 83%, P = 0.02). CONCLUSION: Tumor oxygenation affects the prognosis of head and neck cancer independently of other known prognostic variables. This parameter may be a useful tool for the selection of patients for investigational treatment strategies.

Expression of Fos in the superior lateral subdivision of the lateral parabrachial (LPBsl) area after generalized tonic seizures in rats.

Generalized tonic-clonic seizures of brain stem origin in rats are associated with acute induction of neuronal Fos in several discrete regions of the brain. One particular site in the dorsal pons shows remarkable Fos induction following generalized tonic seizures induced by maximal electroshock in normal rats or by audiogenic stimulation in genetically epilepsy-prone rats (GEPRs). Although this area shows the most intense Fos induction of any brain area following generalized tonic seizures, its identity has been uncertain. Based on its general location, we hypothesized that this nucleus was either 1) a component of the pedunculopontine tegmentum nucleus-pars compacta (PPTn-pc) or 2) the superior lateral subnucleus of lateral parabrachial area (LPBsl). The present study used Fos-protein immunocytochemistry in combination with the reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry, cholecystokinin (CCK) immunocytochemistry, and neuronal tract-tracing to determine the identity of this cluster of Fos-immunoreactive neurons in the dorsal pons. Following maximal electroshock seizure (MES), Fos labeling was compared to NADPH diaphorase staining (a marker for cholinergic neurons of the PPTn-pc); retrograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected into the ventromedial nucleus of the hypothalamus (VMH; to identify the LPBsl) or CCK immunoreactivity (also a marker for LPBsl neurons). Results showed this cluster of Fos immunoreactive (FI) neurons to be closely associated, but not overlapping, with the lateral and most caudal aspect of the PPTn-pc. Alternatively, WGA-HRP retrograde-labeled neurons corresponded precisely with the seizure-induced FI neurons. Additionally, the location of CCK immunoreactive neurons directly overlapped with the FI neurons, although they were not nearly as prevalent. These results demonstrate that the seizure-induced FI neurons in this area are neurons of the LPBsl and not cholinergic neurons of the PPTn-pc. This is the first report of seizure-induced Fos expression specifically localized to the superior lateral subnucleus of the lateral parabrachial area.

Reproductive endocrinopathy in acute streptozotocin-induced diabetic male rats. Studies on LHRH.

Streptozotocin-(STZ) treated diabetic male rats have significant reproductive endocrinopathy. To determine the functional responsiveness of luteinizing hormone-releasing hormone (LHRH) neurons in STZ-treated diabetic male rats, stimulated LHRH release was assessed using hypothalami from short-term STZ-treated, STZ-treated insulin-replaced, and control male rats. LHRH release from control, STZ-treated, and STZ-treated, insulin-replaced explants in response to an initial and second 30-min pulse of phenylephrine were not different. A terminal pulse, containing 45 mM KCl, a general secretogogue, also revealed no differences between groups in stimulated LHRH release. Glucose and testosterone levels in the controls and the diabetic rats were significantly different. Cell counts on serial brain sections processed for LHRH immunohistochemistry suggested that the number of LHRH neurons in the preoptic area (POA) and septal areas were not different between control and STZ-treated rats. Thus, the short-term STZ-treated rats of this study were diabetic, and they displayed associated endocrinopathy; however, explants obtained from control and STZ-treated rats exhibited a typical LHRH responsiveness to both phenylephrine and KCl, and appeared similar in LHRH neuron number. Therefore, these findings suggest that reproductive endocrinopathy accompanying short-term STZ-induced diabetes in male rats does not result from deficiency in LHRH neurons per se.

Neurite extension of developing noradrenergic neurons is impaired in genetically epilepsy-prone rats (GEPR-3s): an in vitro study on the locus coeruleus.

A primary determinant of seizure susceptibility and severity in genetically epilepsy-prone rats (GEPRs), is a generalized deficiency in the central noradrenergic system of these animals. In particular, this deficiency includes reduced numbers of norepinephrine (NE) synaptic terminals in several brain areas and distinctly fewer NE axons within the auditory tectum. Two strains of GEPRs have been developed: GEPR-3s that have moderately severe clonic seizures and GEPR-9s that have severe tonic seizures culminating in complete hindlimb extension. Seizures in animals of each substrain are preceded by a brief episode of wild running. The developmental profile of NE axonal growth in GEPRs compared to control rats is not known, but may be causally related to NE deficiencies in this seizure model. The present study compared developmental neurite extension of fetal NE neurons in vitro between GEPR-3s and Sprague-Dawley control rats, the strain from which GEPR-3s were originally derived. Neurite arborization of individual NE neurons was assessed by quantitative morphometry following immunocytochemical identification of tyrosine hydroxylase (TH). Preliminary studies using explant and dispersed-cell cultures of control-rat tissues showed that optimal culture parameters to support neuritogenesis of LC neurons included the use of dispersed-cell cultures, Pronectin-F substrate, day-14 gestation donor-tissue, no use of cytosine-arabinofuranoside (ARA-c, a glial mitotic inhibitor) and the presence of co-cultured tectal tissue. Compared to fetal control-rat NE neurons co-cultured with fetal control-rat tectum, NE neurons derived from fetal GEPR-3 LC in co-culture with GEPR-3 tectum exhibited only 30% of the neurite extension of control-rat LC neurons and GEPR-3 LC neurons had a similarly deficient amount of branching. This study suggests, but does not prove, that deficiency in tectal NE in GEPR-3s involves a developmental deficiency in neurite extension from GEPR-3 LC neurons. Hypothetically, this deficiency may also contribute to the well described NE deficiency in other regions of the adult GEPR brain.

Standard vs conformal radiation therapy for adenocarcinoma of the prostate: no difference.

Objective: To compare results of treatment of adenocardinoma of the prostate using Standard (2D) vs Conformal (3D) treatment planning. Methods: The records of all patients with adenocarcinoma of the prostate treated curatively with radiation therapy alone from July 1991 to June 1994 were reviewed. Acute and late complications were scored by the RTOG criteria. Biochemical failure was defined as a rising PSA of at least 10% on two measurements separated >/=1 month or either a PSA nadir >4 ng/ml or >1 ng/ml. Disease free survival (DFS) was defined as no evidence of local, distant, or biochemical failure. 2D planning included standard simulation with target volume drawn from the treatment planning or diagnostic CT. 3D planning included a CT in the treatment position with computer simulation using beam's-eye-view for field design. Results: Two-hundred and seventeen 2D and 45 3D patients had similar median age and pre-treatment PSA, T-stage, and dose to the prostate. The median follow-up periods for the 2D and 3D groups were 32.0 and 21.5 months, respectively. The two-year actuarial survival, local or biochemical control, and DFS were not different. The 3D group had a significantly higher incidence of acute bladder side effects of all grades and acute grade 1/2 rectal complications. There were no differences in the incidence of late bladder or rectal complications. Conclusions: Careful 2D planning for the treatment of localized adenocarcinoma of the prostate is an acceptable means of treatment. Within the dose range of 64-70 Gy, this preliminary analysis demonstrated no reduction in complications nor improvement in local or biochemical control, or DFS was seen with the the use of 3D treatment planning.

Fos in locus coeruleus neurons following audiogenic seizure in the genetically epilepsy-prone rat: comparison to electroshock and pentylenetetrazol seizure models.

Seizures in genetically epilepsy-prone rats (GEPRs) may result from hypoactivity of locus coeruleus (LC) neurons during seizures. This study examined Fos-like-immunoreactivity (FLI) in the LC following audiogenic seizures in two strains of GEPRs (GEPR-9s and -3s), and following pentylenetetrazol (PTZ) or maximal electroshock seizures (MES) in normal rats. After tonic seizure, GEPR-9s showed an identical LC-FLI response to that of normal rats following tonic seizures induced by either PTZ or MES. GEPR-3s, having clonic seizures, had less FLI in the LC. Therefore, stimulus-transcription coupling in the GEPR LC is apparently normo-typic in its FLI response to seizure and thus is not likely the root cause of NE abnormalities in this seizure model.

Seizures and proto-oncogene expression of fos in the brain of adult genetically epilepsy-prone rats.

The mechanisms and brain circuitry that render genetically epilepsy-prone rats (GEPRs) susceptible to acoustically induced seizures are not completely known. The present study explores the neuroanatomy of acoustically induced seizures by immunohistochemical analysis of the proto-oncoprotein fos after intense acoustic stimulation (AS) with and without seizures. Acoustic stimulation induced tonic convulsions in GEPR-9s, but not in control rats. Locations of brain nuclei showing fos-like immunoreactive (FLI) neurons following AS with and without seizures were mapped. Semiquantitative methods were used to compare FLI neuron numerical densities in AS control rats and GEPRs. Many brain areas exhibited profound FLI in AS control rats and GEPRs. Unexpectedly, the cochlear nuclei and the central nucleus of the inferior colliculi (ICc), both of which are requisite for AGS initiation, exhibited a diminished fos expression in animals having seizures compared to AS controls. In contrast, GEPRs displayed a significant increase in FLI neurons within the dorsal cortex of the IC (ICd) compared to AS controls. This finding may suggest a seizure-related amplification of the auditory signal between the ICc and the ICd. Other nuclei, known to be involved in auditory transmission (i.e., superior olivary complex; trapezoid nucleus; dorsal nucleus of the lateral lemniscus, DNLL), did not show differential FLI densities between seizure and AS control animals. In contrast, seizure-induced FLI was observed in many nonauditory brain nuclei. Of particular interest was the identification of an intensely labeled nucleus in the GEPR. This nucleus resides in the most posterior and dorsal-lateral part of the pedunculopontine tegmental nucleus-pars compacta (PPTn-pc) immediately adjacent to the DNLL and extends posteriorly into the superior lateral subnucleus of the lateral parabrachial area (SLPBn). Therefore, we have tentatively termed this nucleus the PPSLPBn. The PPSLPBn lies in a region previously described as a mesencephalic locomotor region and a suspected functional involvement of this nucleus in display of seizure activity is under investigation. Other brain stem nuclei showing differential fos expression between GEPRs and AS control rats are also described.

Testing knowledge of human gross anatomy in medical school: an applied contextual-learning theory method.

The traditional gross anatomy laboratory experience, with modifications in evaluations that we outline later, meets the criteria of contextual-learning theory, expands the repertoire of core objectives we identify for our students, and may increase the likelihood of cognitive permanence of anatomical data. Our subjects included approximately 54 first-year medical students from each of three sequential class years (1996, 1997, 1998). As an alternative to more typical written and practical exams, examinations in a major portion of our gross anatomy program consist of two approximately 30 minute oral expositions by each student to his or her peers and a faculty member. Students demonstrate specific detail on cadaver, x-ray, cross sections, or a model. Clinical applications, spatial relationships, nomenclature, and functions are strongly emphasized. The results of this teaching approach to the utilization of anatomical knowledge in clinical situations requires further assessment: however, new attributes have been afforded our students with implementation of the present program: First, students learn anatomical detail equally well as the students of the more traditional system (based on board exam results). Second, students who completed the program indicate that this approach provides a useful simulation of what is expected later in their training. Third, students gradually gain confidence in verbal presentation, they demonstrate cognitive synthesis of separate conceptual issues, they retain information, and they are quite visibly more enthusiastic about anatomy and its importance in medicine. Our program demonstrates that the learning of applicable human anatomy is facilitated in a contextual-learning environment. Moreover, by learning anatomy in this way, other equally beneficial attributes are afforded the medical student, including, but not limited to, increases in communication skills, confidence in verbal presentation, synthesis of anatomical concepts, appreciation of the clinical importance of anatomy, and the general development of professionalism.

Effect of 5,7-dihydroxytryptamine on audiogenic seizures in genetically epilepsy-prone rats.

To further assess the role of 5-HT in the modulation of audiogenic seizures (AGS) in the Genetically Epilepsy-Prone Rat (GEPR), changes in AGS severity after widespread chronic depletion of brain 5-HT by intracerebroventricular administration of 5,7-dihydroxytryptamine (5,7-DHT) were examined in moderate seizure GEPRs (GEPR-3s). Following treatment with 5,7-DHT (150 micrograms/30 microliters), a significant increase in seizure severity was observed at 2, 3 and 4 weeks as compared to vehicle-injected controls. The increase in seizure severity was evidenced by a significant increase in the incidence of tonic convulsions in 5,7-DHT treated animals (53% in treated animals compared to 0% in vehicle treated controls) over the testing period. Interestingly, the latency to wild running was increased in 5,7-DHT treated GEPRs, suggesting that depletion of brain 5-HT may slow initiation of AGS. Neurochemical analysis revealed marked depletion of 5-HT in the cortex (-96%), hippocampus (-94%), thalamus (-80%), hypothalamus (-62%), midbrain (-51%) and pons-medulla (-52%) in animals that received 5,7-DHT. However, no significant reductions in brain norepinephrine content were observed in any of the regions assayed due to the pretreatment of all animals with protriptyline. The present findings lend further support for an inhibitory action of brain 5-HT on audiogenic seizures in GEPRs.

Effects of intraventricular locus coeruleus transplants on seizure severity in genetically epilepsy-prone rats following depletion of brain norepinephrine.

Audiogenic seizures (AGS) in genetically epilepsy-prone rats (GEPR) of the moderate-seizure substrain (GEPR-3s) were investigated to determine whether norepinephrine (NE) depletion induced by 6-hydroxydopamine (6-OHDA) microinfusion into the locus coeruleus (LC) could alter the efficacy of intraventricular NE tissue grafts in promoting reductions in seizure severity in AGS. GEPR-3s were stereotaxically infused with 6-OHDA (4 micrograms/side/rat), or vehicle into the region of the LC. Following 6-OHDA treatment all animals were subjected to 3 AGS tests. GEPR-3s seizure severities were increased in 39.5% of the animals after microinfusion of 6-OHDA into the region of the LC. Following the third AGS test, each rat was stereotaxically implanted with 17 gestational day rat fetal tissue obtained from the dorsal pons and containing the primordia of the LC or with tissue obtained from the neocortex or were sham-grafted. Subsequent to grafting, rats were subjected to 3 additional AGS tests. 53% (10/19) of 6-OHDA treated GEPRs showed a significant reduction in seizure severity following transplantation of fetal LC tissue. In contrast, only 20% (1/5) of GEPRs infused with saline rather than 6-OHDA showed a reduction of seizure severity following fetal LC transplantation. NE content in the cortex and pons/medulla was decreased by 78% and 46% respectively following 6-OHDA microinfusion into the LC. Prominent grafts with numerous TH positive neurons and neurites were present within the third ventricle of grafted animals, while cortex grafts contained no TH immunostained structures. These findings suggest that the efficacy of fetal LC tissue to promote reductions in seizure severity in GEPRs is increased following depletion of central NE by microinfusion of 6-OHDA.

Prolactin response to anesthetic stress and beta-endorphin is altered in female rats treated neonatally with monosodium glutamate.

MSG (4 mg/g, sc) or saline was administered to neonatal female rats on days 1, 3, 5, 7 and 9. Study 1) Prl levels were assessed at 30, 60 and 75 days after birth to monitor possible development of hyperprolactinemia. No hyperprolactinemia was observed at any time studied. Study 2) MSG and control rats were administered pentobarbital anesthesia at 2 months of age. At 20, 60 and 90 min following anesthesia, plasma was collected for assay of Prl. 20 min prior to the 90 min bleeding, BE (5 micrograms/5 ul) was stereotaxically administered, into the third ventricle. MSG-treated rats had an attenuated Prl response to the stress of anesthesia (bleeding 1). Prl levels in control and MSG-treated rats were similar at 60 min post-anesthesia (bleeding 2) which represented a return of Prl levels to baseline after stress-induced elevation of Prl. Control and MSG-treated rats exhibited an increase in plasma Prl following intracerebroventricular BE; however, the amplitude of this response was markedly attenuated in the MSG-treated animals (bleeding 3). Thus, an observed loss of TH-positive neurons in the arcuate nucleus of the hypothalamus following MSG treatment and the attenuated response of Prl to anesthesia-stress and BE administration suggests that Prl secretion in response to these agents is operative through inhibition of the TIDA system. Furthermore, these studies show that the Prl response to these agents (anesthetic and BE) is intact but sub-operational in MSG-treated rats.