Plasma total prion protein as a potential biomarker for neurodegenerative dementia: diagnostic accuracy in the spectrum of prion diseases.

AIMS: In the search for blood-based biomarkers of neurodegenerative diseases, we characterized the concentration of total prion protein (t-PrP) in the plasma of neurodegenerative dementias. We aimed to assess its accuracy in this differential diagnostic context. METHODS: Plasma t-PrP was measured in 520 individuals including healthy controls (HC) and patients diagnosed with neurological disease control (ND), Alzheimer's disease (AD), sporadic Creutzfeldt-Jakob disease (sCJD), frontotemporal dementia (FTD), Lewy body dementia (LBD) and vascular dementia (VaD). Additionally, t-PrP was quantified in genetic prion diseases and iatrogenic CJD. The accuracy of t-PrP discriminating the diagnostic groups was evaluated and correlated with demographic, genetic and clinical data in prion diseases. Markers of blood-brain barrier impairment were investigated in sCJD brains. RESULTS: Compared to HC and ND, elevated plasma t-PrP concentrations were detected in sCJD, followed by FTD, AD, VaD and LBD. In sCJD, t-PrP was associated neither with age nor sex, but with codon 129 PRNP genotype. Plasma t-PrP concentrations correlated with cerebrospinal fluid (CSF) markers of neuro-axonal damage, but not with CSF t-PrP. In genetic prion diseases, plasma t-PrP was elevated in all type of mutations investigated. In sCJD brain tissue, extravasation of immunoglobulin G and the presence of swollen astrocytic end-feet around the vessels suggested leakage of blood-brain barrier as a potential source of increased plasma t-PrP. CONCLUSIONS: Plasma t-PrP is elevated in prion diseases regardless of aetiology. This pilot study opens the possibility to consider plasma t-PrP as a promising blood-based biomarker in the diagnostic of prion disease.

[Minimally invasive anterior approach]. / Der minimal-invasive anteriore Zugang.

The minimally invasive direct anterior approach for total hip arthroplasty (THA) was first published in 1985. Since then the technique has been further improved and the indications have been extended. The approach utilizes the muscle gap between the tensor fasciae latae muscle on the lateral side and the sartorius muscle on the medial side. This muscle gap allows a direct and quick approach to the hip joint with good muscle preservation. During preparation of the femur the tensor fasciae latae muscle is at risk of being damaged. The lateral cutaneous nerve of the thigh (NCFL) and its branches are also in danger of being damaged during skin incision and dissection of the subcutaneous tissue. In this article the technique, risks and current clinical results of THA using the minimally invasive direct anterior approach are described. The results from the literature, as well as own results are compared to the traditional transgluteal lateral Bauer approach and discussed. Reviewing the literature, special attention has been given to the incidence of NCFL lesions, damage of the tensor fasciae latae muscle and positioning of the cup. Especially for the latter, the general view is hindered in the minimally invasive technique.

Distress in patients with newly diagnosed brain tumours.

OBJECTIVE: Patients with intracranial tumours often suffer from clinically relevant psychological distress. However, levels of distress and contributing factors have not been systematically evaluated for the early course of the disease. Using the National Comprehensive Cancer Network's Distress Thermometer (DT), we evaluated the extent and sources of distress within a population of patients with intracranial neoplasms. METHODS: One hundred and fifty-nine patients were included who underwent craniotomy for newly diagnosed intracranial tumours at our department. All patients completed the DT questionnaire, a single-item 11-point visual analogue scale measuring psychological distress. The appendant problem list (PL) consists of 40 items representing problems commonly experienced by cancer patients. Patients were asked to mark any experienced sources of distress. RESULTS: Percentage of patients suffering from relevant distress was 48.4% (cut-off ≥6). DT-scores were significantly associated with depression and anxiety as well as reported number of concerns. On average, patients reported 6.9 sources of cancer-related distress. Objective medical data (e.g. tumour stage) as well as sociodemographic data (e.g. gender, IQ) were not associated with psychological distress at this early phase. CONCLUSIONS: Prevalence of elevated distress is high shortly after primary neurosurgical treatment in patients with intracranial tumours and cannot be predicted by objective data. As a consequence, sources of distress can and should be routinely assessed and targeted in these individuals in this particular period. Further studies are needed to help to identify patients who are at risk of suffering from long-term emotional distress in order to enable targeted psychosocial intervention.

[The German version of parents' postoperative pain measure (PPPM-D). Validation on children 2-12 years old]. / Die deutsche Version des Parents' Postoperative Pain Measure (PPPM-D). Validierung an Kindern im Alter von 2 bis 12 Jahren.

BACKGROUND: Parents become increasingly more responsible for the postoperative pain management of their children. Useful and valid pain assessments for parents may improve pain measurement. The aim of this study was to evaluate a German version of the parents' postoperative pain measure (PPPM-D). METHODS: After translation of the PPPM into German 52 children between 2 and 12 years of age, undergoing orthopedic and trauma surgery, were included in a prospective study. At least one of the parents completed the PPPM-D on the preoperative day and the day of surgery until postoperative day 5. Both, the children's and infants postoperative pain scale (CHIPPS) for children between 2 and 4 years and the faces pain scale revised (FPS-R) for children between 5 and 12 years were also assessed. Moreover, the acceptance of the PPPM-D by the parents was assessed. RESULTS: The PPPM-D showed satisfactory reliability (Cronbach's α values = 0.77-0.87). Construct validity was demonstrated with strong correlations with the CHIPPS and the FPS-R. Discriminative validity was shown by both statistically and clinically significant differences between minor, medial and major surgeries on the first 3 days after surgery. The examination of sensitivity to change yielded promising results. The PPPM-D was well accepted by the participating parents. CONCLUSIONS: The results of this study provide evidence of the reliability, validity and high acceptance of the PPPM-D as an assessment tool of postoperative pain among children aged 2 through to 12 years of age after orthopedic or trauma surgery.

[Perioperative pain therapy in interventions for elbow stiffness]. / Perioperative Schmerztherapie bei Eingriffen wegen Ellenbogengelenksteife.

Conservative treatment and surgical release of a stiff elbow requires correct pain management which should be oriented to the individual needs of the patient. Regional anesthesia in combination with opioids is necessary postoperatively to obtain sufficient pain relief. There is a need for prospective randomized studies to develop an optimal pain therapy concept following operations for elbow stiffness.

[Elevated postoperative pain levels following orthopedic surgery. Depression as a strong predictor]. / Erhöhter postoperativer Schmerz nach orthopädischen Operationen. Depression als starker Prädiktor.

The aim of this study was to examine whether depression is a strong predictor of elevated postoperative pain levels following orthopedic surgery and whether the implementation of standardized pain management is more beneficial for patients with depression. We performed a non-randomized, prospective study with two different groups of patients who underwent orthopedic surgery. Group 1 (n=249) received non-standardized pain therapy whereas group 2 (n = 243) was treated with a standardized pain management concept. Effects of the treatment were monitored with a VAS-based pain assessment protocol. Depression was measured preoperatively with the self-reported Patient Health Questionnaire (PHQ-9). Patients with the probable diagnosis of a current episode of major depression showed significantly higher postoperative pain than patients without a depressive episode. On the other hand, patients with depression benefited from the implementation of standardized pain management. Our data suggest a predictive value of depression for severe postoperative pain. Patients with depression benefited from standardized postoperative pain therapy, but were still suffering from significantly higher postoperative pain.

Carcinoembryonic antigens: alternative splicing accounts for the multiple mRNAs that code for novel members of the carcinoembryonic antigen family.

The recent cloning of complete cDNAs encoding carcinoembryonic antigen (CEA) and non-specific cross-reacting antigen has revealed the existence of a new gene family belonging to the immunoglobulin gene superfamily. We have reported the isolation of a partial CEA cDNA and of L-cell transfectant cell lines that express human antigens cross-reactive with commercial antibodies directed to native CEA (Kamarck, M., J. Elting, J. Hart, S. Goebel, P. M. M. Rae, J. Nedwin, and T. Barnett. 1987. Proc. Natl. Acad. Sci. USA. 84:5350-5354). In this study, we describe the identification and cloning of 3.9-, 3.7-, 2.2-, and 1.8-kb cDNAs and a 23-kb genomic transcription unit, which code for new members of the CEA gene family. DNA sequence analysis of these cloned DNAs establishes the existence of a set of four alternatively spliced mRNAs which are expressed in several tumor cell lines, in human fetal liver, and in L-cell transfectants. Deduced amino acid sequences of the encoded isoantigens show extensive similarity to CEA and nonspecific cross-reacting antigens, but in addition demonstrate transmembrane and cytoplasmic domains. We designate members of this antigen family transmembrane CEAs. The transmembrane CEA isoantigens share general structural characteristics with members of the immunoglobulin gene superfamily and can be specifically compared to the cell adhesion molecules, N-CAM (neural cell adhesion molecule) and MAG (myelin-associated glycoprotein).

[Implementation of standardized postoperative pain therapy for orthopaedic patients. Comparison between unsystematic and standardized pain therapy]. / Implementierung einer standardisierten Schmerztherapie bei postoperativen orthopädischen Patienten. Vergleich einer unsystematischen mit einer standardisierten Schmerztherapie.

BACKGROUND: The painless clinic and postoperative pain therapy are currently major issues in the management of surgical procedures. The aim of this study was to evaluate the benefit of a standardized pain therapy on the postoperative pain level after orthopaedic procedures. PATIENTS AND METHODS: We investigated two different groups of patients who underwent an orthopaedic surgical procedure. Group 1 (n = 249) received a pain therapy which was based on an individual and surgery-dependent concept whereas group 2 (n = 243) was treated with a standardized pain therapy concept. The effect of the treatment was monitored with a VAS-based protocol. RESULTS: Up to day 9 after surgery there was a significant difference between the two groups in regard to the postoperative pain. The patients of group 2 had less pain but had more unwanted side effects caused by the pain therapy during the first 3 days after surgery. Mobility and mental disposition were positively affected. CONCLUSION: The implementation of a standardized pain therapy is successful in reducing postoperative pain. Mobility and mental disposition are also influenced positively. As a consequence the incidence of unwanted side effects is rising.

Deep brain stimulation for movement disorders and its neuropsychological implications.

Deep brain stimulation (DBS) has gained increasing attention as a therapy for movement disorders. Neuropsychological alterations can accompany the disease evolution and medical therapy of PD. Also, interfering abruptly with the biological balance by means of a surgical intervention into complex circuits with motor but also cognitive and limbic functions, could potentially cause severe problems. Because cognitive or emotional impairments may have an even stronger impact on quality of life, than motor symptoms, care must be taken to perform surgery in the safest possible way to exclude adverse effects in these domains. Detailed neuropsychological evaluations may become helpful to further understand the mechanisms underlying some aspects of the clinical pictures both pre- and postoperatively and to define risk populations, that should be excluded from this intervention.

Investigations of the potential risk factors associated with cases of bovine spongiform encephalopathy in Bavaria, Germany.

In order to identify the management and feeding practices that might have contributed to the occurrence of bovine spongiform encephalopathy (BSE) in Bavaria, Germany, information from 110 dairy farms on which a case of BSE had been reported was compared with information derived from a questionnaire sent to approximately 10,000 Bavarian farms on which no case of BSE had been reported up to February 2003. Representative information was obtained from 4006 dairy farms. The results indicated that in comparison with these control farms a higher proportion of the BSE farms had also kept pigs or poultry, although the difference was not significant, and that a significantly higher proportion of the BSE farms had fed proprietary concentrates and/or milk replacers to their calves.

Identical clonality of sporadic gastrinomas at multiple sites.

Gastrinomas are neuroendocrine neoplasms that occur sporadically and in patients with multiple endocrine neoplasia type 1 (MEN1). In MEN1, multiple gastrinomas have been shown to arise by independent clonal events (Debelenko, et al., Cancer Res., 57: 2238-2243, 1997). The purpose of the present study was to analyze clonality in 20 sporadic gastrinomas from eight patients in whom the tumor was present in at least two separate sites. A combination of methods was used to assess clonality, including MEN1 gene mutation analysis, loss of heterozygosity analysis of the MEN1 locus, and analysis of X-chromosome inactivation at the human androgen receptor locus (human androgen receptor analysis). In three patients, a somantic MEN1 gene mutation was detected in the tumor. Identical mutations were found in other tumors at different sites within the same patients. Human androgen receptor analysis in three informative patients and loss of heterozygosity analysis in five patients revealed identical clonal patterns in the tumors from multiple sites in each patient. We conclude that sporadic gastrinomas at multiple sites are monoclonal and that MEN1 gene alterations in gastrinomas occur before the development of tumor metastases.

Prospective study of the clinical course, prognostic factors, causes of death, and survival in patients with long-standing Zollinger-Ellison syndrome.

PURPOSE: The long-term clinical course of unselected patients with gastrinomas as well as other functional pancreatic endocrine tumors (PETs) in whom the excess-hormone state is controlled is largely unknown. To address this issue, patients with gastrinomas were assessed. PATIENTS AND METHODS: Two hundred twelve patients with Zollinger-Ellison syndrome (ZES) were prospectively studied. All had controlled acid hypersecretion and were assessed yearly, with a mean follow-up period of 13.8+/-0.6 years (range, 0.1 to 31 years). Annual assessments of possible factors that might affect prognosis or treatment approaches were performed, such as those for tumor size and location; the presence, location, and extent of metastases; and the occurrence of ectopic Cushing's syndrome or another PET syndrome. Deaths were categorized as ZES-related or non-ZES-related and classified into different causes. RESULTS: Thirty-one percent of patients died, all of non-acid-related causes. One half died of a ZES-related cause; they differed from those who died of non-ZES deaths by having a large primary tumor, more frequently a pancreatic tumor; lymph node, liver, or bone metastases; ectopic Cushing's syndrome; or higher gastrin levels. The extent of liver metastases correlated with survival rate. The presence of liver metastases alone only moderately decreased survival time; however, the additional development of bone metastases or ectopic Cushing's syndrome markedly decreased survival rate. CONCLUSIONS: In ZES, gastrinoma growth is now the main single determinant of long-term survival, with one half of patients dying a gastrinoma-related death and none an acid-related death. Large primary tumors that are pancreatic in location, the development of liver metastases, (especially if associated with bone metastases or Cushing's syndrome), and the extent of liver metastases are all important prognostic factors. The identification of these factors allows the recognition of subgroups that can be used to tailor antitumor treatment approaches.

Indirect evidence to suggest that prolactin mediates the adrenal action of haloperidol to stimulate aldosterone and corticosterone secretion in rats.

The effect of dopamine-antagonists on steroid secretion has revealed conflicting results regarding the confirmation of in vivo findings in vitro. In order to discriminate in vivo systemic and local action of the dopamine-antagonist haloperidol (HAL) on aldosterone and corticosterone secretion, microdialysis of the adrenal cortex in conscious, freely moving rats was employed. The effects of 2.5 mg HAL ip or intraadrenal dialysis of 20 micrograms/ml HAL in rats with an intact pituitary gland on PRL, aldosterone, and corticosterone secretion were examined. Systemic HAL application resulted in a 40-fold increase in PRL secretion and stimulated aldosterone and corticosterone production significantly. In contrast, intraadrenal dialysis of HAL had no effect on the secretory pattern of PRL or either steroid hormone, indicating no direct drug action on cells of the rat adrenal cortex. Similarly, ip injection of 2.5 mg HAL in hypophysectomized rats did not alter PRL or steroid hormone levels. We conclude that the dopamine-antagonist HAL stimulates aldosterone and corticosterone secretion in rats through a pituitary factor, probably PRL, but not through direct effects at the adrenal cortex.

Alterations in the p16INK4a/CDKN2A tumor suppressor gene in gastrinomas.

The p16INK4a/CDKN2A gene (p16INK4a) is frequently altered by homozygous deletion, mutation, or methylation in many nonendocrine tumors, and these alterations may be predictive of recurrence, tumor growth, or aggressiveness. Whether this is true of neuroendocrine tumors such as gastrinomas is unclear. To address this question we analyzed the gastrinomas from 44 patients for p16INK4a gene mutations and correlated the results to the tumor's biological behavior, growth pattern, and aggressiveness. No gastrinomas had mutations of exon 1 or exon 2 of the p16INK4a gene, although polymorphisms were found in 54%. No homozygous deletions were found. In 52% of the gastrinomas, hypermethylation of a 5'-CpG island of the p16INK4a gene promoter was found. To assess the growth behavior of the gastrinomas, all patients were assessed yearly with at least three conventional imaging studies (computed tomography scan, magnetic resonance imaging, and ultrasound), and since 1994 have been assessed with radionuclide scanning using [111In-diethylenetriamine pentaacetic acid,DPhe1]octreotide. The mean follow-up was 5.1+/-0.4 yr (range, 1.2-11.7). The presence or absence of methylation of the p16INK4a gene did not correlate with clinical characteristics of the gastrinoma, biological behavior (gastrin release and basal or maximal acid output), the presence or absence of known prognostic factors (tumor size, gastrinoma location, lymph node metastases, liver metastases, and curability), or growth pattern of the gastrinoma postresection. These results indicate that methylation of the p16INK4a gene is the most common gene alteration described to date in gastrinomas. Furthermore, because it is independent of disease stage it is probably an early event in the pathogenesis and because it is independent of the primary gastrinoma location, which is now thought to have different origins, methylation of the p16INK4a gene is probably a central process in the molecular pathogenesis of these tumors.

Expression of the calcium-sensing receptor in gastrinomas.

Extracellular calcium levels are able to influence the secretion of gastrin by gastrinomas and possibly affect the growth pattern. The molecular mechanisms of these functions are not known. The purpose of the present study was to investigate the presence of the calcium-sensing receptor (CaR) in 10 gastrinomas and determine the extent of expression in the tumors. The amounts of CaR messenger ribonucleic acid in eight tumors were determined by quantitative RT-PCR. Protein expression was analyzed by Western blot and immunohistochemistry using a monoclonal antibody (ADD). CaR messenger ribonucleic acid was detected in all gastrinomas with levels ranging from 0.04-3.16 times the amount of beta-actin transcripts. The Western blot showed a major immunoreactive band at 250 kDa and a minor at 140 kDa, corresponding to the receptor dimer and monomer, respectively. Immunohistochemistry demonstrated variable membranous staining in all gastrinomas and normal pancreatic islets. No staining was observed in the normal liver, lymph node, or exocrine pancreas. We conclude that the CaR is present in all gastrinomas, with expression varying by 80-fold. It probably contributes to the calcium-stimulated gastrin release by gastrinomas. Whether the density of the CaR is a determining factor of the magnitude of this gastrin release or plays a role in regulating the growth pattern of the gastrinoma, as it does in other cells, remains unclear at present.

Genotype/phenotype correlation of multiple endocrine neoplasia type 1 gene mutations in sporadic gastrinomas.

Multiple endocrine neoplasia type 1 (MEN1) gene mutations are reported in some gastrinomas occurring in patients without MEN1 as well as in some other pancreatic endocrine tumors (PETs). In some inherited syndromes phenotype-genotype correlations exist for disease severity, location, or other manifestations. The purpose of the present study was to correlate mutations of the MEN1 gene in a large cohort of patients with sporadic gastrinomas to disease activity, tumor location, extent, and growth pattern. DNA was extracted from frozen gastrinomas from 51 patients and screened by dideoxyfinger-printing (ddF) for abnormalities in the 9 coding exons and adjacent splice junctions of the MEN1 gene. Tumor DNA exhibiting abnormal ddF patterns was sequenced for mutations. The findings were correlated with clinical manifestations of the disease, primary tumor site, disease extent, and tumor growth postoperatively. Tumor growth was determined by serial imaging studies. Sixteen different MEN1 gene mutations in the 51 sporadic gastrinomas (31%) were identified (11 truncating, 4 missense, and 1 in-frame deletion). Nine of the 16 mutations were located in exon 2 compared to 7 of 16 in the remaining 8 coding exons (P = 0.005 on a per nucleotide basis). Primary pancreatic or lymph node gastrinomas with a mutation had only exon 2 mutations, whereas duodenal tumors uncommonly harbored exon 2 mutations (P = 0.011). Similarly, small primary tumors (<1 cm) more frequently contained a nonexon 2 mutation (P = 0.02). There was no difference between patients with or without a mutation with respect to clinical characteristics, primary tumor site, disease extent, or proportion of patients disease free after surgery. Postoperative tumor growth tended to be more aggressive in patients with a mutation (P = 0.09). No correlation in the rate of disease-free status or postoperative tumor growth in patients with active disease to the location of the mutation was seen. These results demonstrate that the MEN1 gene is mutated in 31% of sporadic gastrinomas, and mutations are clustered between amino acids 66-166, which differs from patients with familial MEN1, in whom mutations occur throughout the gene. The presence of an MEN1 gene mutation does not correlate with clinical characteristics of patients with gastrinomas, gastrinoma extent, or growth pattern; however, the location of the mutation differed with gastrinoma location. These data suggest that mutations in the MEN1 gene are important in a proportion of sporadic gastrinomas, but the presence or absence of these mutations will not identify the clinically important subgroups with different growth patterns.

Dynorphin A toxicity in striatal neurons via an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptor mechanism.

Dynorphin A (1-17) is an endogenous opioid peptide that is antinociceptive at physiological concentrations, but in excess can elicit a number of pathological effects. Both kappa-opioid and N-methyl-D-aspartate receptor antagonists modulate dynorphin toxicity, suggesting that dynorphin is acting directly or indirectly through these receptor types. We found in spinal cord neurons that the neurotoxic effects of dynorphin A and several dynorphin-derived peptide fragments are largely mediated by N-methyl-D-aspartate receptors. Despite these findings, aspects of dynorphin A toxicity could not be accounted for by opioid or N-methyl-D-aspartate receptor mechanisms. To address this issue, neurons enriched in kappa-opioid, N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors were isolated from embryonic day-15 mouse striata and the effects of extracellularly administered dynorphin A (1-17) and (13-17) on neuronal survival were examined in vitro. Unlike spinal cord neurons, N-methyl-D-aspartate receptors mature later than alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptors in striatal neurons, thus providing a strategy to elucidate non-N-methyl-D-aspartate receptor-mediated mechanisms of toxicity. Time-lapse photography was used to repeatedly follow the same neurons before and during experimental treatments. Dynorphin A (1-17 or 13-17; 10 microM) caused significant neuronal losses after 48 to 72 hours versus untreated controls. Dynorphin A or A (13-17) toxicity was unaffected by the opioid receptor antagonist naloxone (10 microM) or by dizocilpine (10 microM). In contrast, the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline- 2,3-dione (10 microM) significantly attenuated only dynorphin A (1-17)-induced neuronal losses and not that induced by dynorphin A (13-17). Dynorphin A (1-17) toxicity was accompanied by a proportional loss of R2 and R3 subunits of the AMPA receptor complex, but not non-N-methyl-D-aspartateR1, expressing neurons and was mimicked by the ampakine 1-(1,4-benzodioxan-6-ylcarbonyl)piperidine. Although it is unclear whether dynorphin A activates alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptors directly or indirectly via glutamate release, our culture conditions do not support glutamate retention or accumulation. Our findings suggest that dynorphin A (1-17) can exert toxic effects on striatal neurons via an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptor mechanism.

Dynorphin A (1-17) induces apoptosis in striatal neurons in vitro through alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptor-mediated cytochrome c release and caspase-3 activation.

Dynorphin A (1-17), an endogenous opioid neuropeptide, can have pathophysiological consequences at high concentrations through actions involving glutamate receptors. Despite evidence of excitotoxicity, the basic mechanisms underlying dynorphin-induced cell death have not been explored. To address this question, we examined the role of caspase-dependent apoptotic events in mediating dynorphin A (1-17) toxicity in embryonic mouse striatal neuron cultures. In addition, the role of opioid and/or glutamate receptors were assessed pharmacologically using dizocilpine maleate (MK(+)801), a non-equilibrium N-methyl-D-aspartate (NMDA) antagonist; 6-cyano-7-nitroquinoxaline-2,3-dione, a competitive alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate antagonist; or (-)-naloxone, a general opioid antagonist. The results show that dynorphin A (1-17) (>or=10 nM) caused concentration-dependent increases in caspase-3 activity that were accompanied by mitochondrial release of cytochrome c and the subsequent death of cultured mouse striatal neurons. Moreover, dynorphin A-induced neurotoxicity and caspase-3 activation were significantly attenuated by the cell permeable caspase inhibitor, caspase-3 inhibitor-II (z-DEVD-FMK), further suggesting an apoptotic cascade involving caspase-3. AMPA/kainate receptor blockade significantly attenuated dynorphin A-induced cytochrome c release and/or caspase-3 activity, while NMDA or opioid receptor blockade typically failed to prevent the apoptotic response. Last, dynorphin-induced caspase-3 activation was mimicked by the ampakine CX546 [1-(1,4-benzodioxan-6-ylcarbonyl)piperidine], which suggests that the activation of AMPA receptor subunits may be sufficient to mediate toxicity in striatal neurons. These findings provide novel evidence that dynorphin-induced striatal neurotoxicity is mediated by a caspase-dependent apoptotic mechanism that largely involves AMPA/kainate receptors.

Specificity of somatostatin receptor scintigraphy: a prospective study and effects of false-positive localizations on management in patients with gastrinomas.

UNLABELLED: Somatostatin receptor scintigraphy (SRS) is being increasingly used both for localization and, in some cases, diagnosis of various diseases. There are no prospective studies of its specificity or occurrence of false-positive results and their effects on management. This study was designed to address both of these issues. METHODS: Over a 40-mo period, 146 consecutive patients with Zollinger-Ellison syndrome (ZES) undergoing 480 SRS examinations were studied prospectively. Patients were admitted at least yearly and underwent SRS as well as conventional imaging studies (ultrasonography, CT, MRI) and angiography, if necessary. All admissions were assigned to one of five different clinical categories in which imaging studies had different purposes. SRS localizations were classified as true-positive or false-positive based on preset criteria. A false-positive result was determined to change clinical management based on five preset criteria. RESULTS: Of all SRS examinations, 12% resulted in a false-positive localization for a neuroendocrine tumor or its metastases, resulting in a sensitivity of 71%, specificity of 86% and positive and negative predictive values of 85% and 52%, respectively. Extra-abdominal false-positive localizations (2/3) were more common than intra-abdominal (1/3). Thyroid disease, breast disease and granulomatosis lung disease were the most frequent causes of extra-abdominal false-positive localizations. Accessory spleens, localization to previous operative sites, renal parapelvic cysts and various procedural aspects were the most frequent causes of intra-abdominal false-positive localizations. Of all SRS studies, 2.7% resulted in a false-positive result that altered management. CONCLUSION: False-positive SRS localization occurs in 1 of 10 patients with ZES. By having a thorough understanding of diseases or circumstances that result in false-positive localization and comparing the SRS result with the clinical context, the percentage of patients in whom false-positive localization results in altered management can be reduced to below 3% and the correct diagnosis made in almost every case.

Influence of preoperative dexamethasone therapy on proliferating cell nuclear antigen (PCNA) expression in comparison to other parameters in meningiomas.

We conducted a trial in 42 benign and malignant meningiomas to assess a possible influence of preoperative dexamethasone therapy on mitotic index, labelling indices of proliferating cell nuclear antigen (PCNA), progesterone receptor, epidermal growth factor receptor (EGF-R), c-erbB-2 oncoprotein, cathepsin D, gamma-gamma enolase as well as the mean number of silver-stained nucleolar organizer region-associated proteins (AgNORs). Tumors with preceding dexamethasone therapy for more than 1 day display significantly less immunohistochemical staining for PCNA. A correlation between the labelling index of PCNA and the degree of malignancy could not be identified. There was no significant effect of preoperative dexamethasone therapy on the other parameters. Our data suggest that dexamethasone may selectively inhibit the expression of PCNA in the G1/S-phase of the cell cycle. Thus, we emphasize the necessity to heed factors, e.g. dexamethasone, which may affect the expression of proliferating markers.