Insulin degrading enzyme is expressed in the human cerebrovascular endothelium and in cultured human cerebrovascular endothelial cells

Insulin degrading enzyme (IDE) is found in the cytosol, peroxisomes and plasma membrane of many cells. Although it preferentially cleaves insulin it can also cleave many other small proteins with diverse sequences including the monomeric form of the amyloid beta peptide (A beta). In the brain, IDE has been reported to be expressed predominantly in neurons. In this study, IDE expression was detected in cultured human cerebrovascular endothelial cells. Using laser capture microdissection followed by PCR analysis, it was found that IDE mRNA is expressed in human brain blood vessels. Using immunofluorescence and multiphoton microscopy IDE was localized to the endothelium of the cerebrovascular blood vessels in human.

The evolution of breast surgery: where technology and compassion meet

The origins and development of The American Society of Breast Surgeons are closely tied to technology. Innovative technical progress means less-invasive procedures, more precise diagnoses, more outpatient services, and--with all of this--less pain and stress for our patients. It means more compassionate breast care for women. The Society's mission revolves around improving all aspects of patient care, and this is where technology and compassion meet.

Updates in breast ultrasound

Ultrasound is becoming an indispensable tool for the surgeon in the diagnosis and treatment of a variety of breast problems. Hands-on ultrasound education for surgeons and the ongoing improvements in imaging technology have made surgeon-performed breast ultrasound an effective method of identifying and diagnosing breast lesions and have increased the surgeon's ability to perform ultrasound-guided interventional procedures. This article reviews the current state of surgeon-performed breast ultrasound.

Escherichia coli Shiga toxin 1 and TNF-α induce cytokine release by human cerebral microvascular endothelial cells

Infection with Shiga toxin (Stx)-producing Escherichia coli can lead to development of hemolytic uremic syndrome (HUS). Patients with severe HUS often exhibit central nervous system (CNS) pathology, which is thought to involve damage to brain endothelium, a component of the blood-brain barrier. We hypothesized that this neuropathology occurs when cerebral endothelial cells of the blood-brain barrier, sensitized by exogenous TNF-alpha and stimulated by Stx1, produce and release proinflammatory cytokines. This was tested by measuring changes in cytokine mRNA and protein expression in human brain endothelial cells (hBEC) in vitro when challenged by TNF-alpha and/or Stx. High doses of Stx1 alone were somewhat cytotoxic to hBEC; Stx1-treated cells produced increased amounts of IL-6 mRNA and secreted this cytokine. IL-1beta and TNF-alpha mRNA, but not protein, were increased, and IL-8 secretion increased without an observed increase in mRNA. Cells pretreated with TNF-alpha were more sensitive to Stx1, displaying greater Stx1-induction of mRNA for TNF-alpha, IL-1beta, and IL-6, and secretion of IL-6 and IL-8. These observations suggest that in the pathogenesis of HUS, Stx can induce cytokine release from hBEC, which may contribute toward the characteristic CNS neuropathology.

cDNA microarray analysis of changes in gene expression associated with MPP+ toxicity in SH-SY5Y cells

cDNA microarray analysis of 1-methyl-4-phenyl-pyridinium (MPP+) toxicity (1 mM, 72 h) in undifferentiated SH-SY5Y cells identified 48 genes that displayed a signal intensity greater than the mean of all differentially expressed genes and a two-fold or greater difference in normalized expression. RT-PCR analysis of a subset of genes showed that c-Myc and RNA-binding protein 3 (RMB3) expression decreased by approximately 50% after 72 h of exposure to MPP+ (1 mM) but did not change after 72 h of exposure to 6-hydroxydopamine (25 microM), rotenone (50 nM), and hydrogen peroxide (600 microM). Exposure of retinoic acid (RA)-differentiated SH-SY5Y cells to MPP+ (1 mM, 72 h) also resulted in a decrease in RMB3 expression and an increase in GADD153 expression. In contrast, c-Myc expression was slightly increased in RA-differentiated cells. Collectively, these data provide new insights into the molecular mechanisms of MPP+ toxicity and show that MPP+ can elicit distinct patterns of gene expression in undifferentiated and RA-differentiated SH-SY5Y cells.

Low-risk palpable breast masses removed using a vacuum-assisted hand-held device

BACKGROUND

This study evaluates the safety, efficacy, and patient acceptance of a vacuum-assisted, hand-held biopsy device (Mammatome) in the percutaneous removal of breast masses using ultrasound guidance.

METHODS

A multicenter, nonrandomized study evaluated 216 women with low-risk palpable lesions. Lesions 1.5 to 3.0 cm in size were removed using an 8-gauge probe. Those lesions <1.5 cm were removed with the 11-gauge probe. Follow-up evaluation was performed at 10 days and 6 months after biopsy.

RESULTS

A total of 127 patients had biopsies using the 8-gauge probe, and 89 patients had biopsies using the 11-gauge probe. At 6-month follow-up, 98% of the lesions remained nonpalpable, 73% with no ultrasonographically visible evidence of the original lesion. Most complications were mild and anticipated. Most patients (98%) were satisfied with incision appearance, and 92% of patients would recommend the procedure to others.

CONCLUSIONS

Percutaneous removal of palpable benign breast masses using the Mammotome system is feasible and safe, and yields high patient satisfaction. The results at 6 months after biopsy demonstrated the effectiveness of benign lesion removal, with correlative clinical data demonstrating lack of palpability and no need for additional procedures. Continuing evaluation of long-term efficacy is ongoing.

Percutaneous removal of benign breast masses using a vacuum-assisted hand-held device with ultrasound guidance

BACKGROUND

This study evaluates the safety, efficacy, and patient acceptance of a vacuum-assisted, hand-held biopsy device (Mammotome) in percutaneous removal of breast masses using ultrasound guidance.

METHODS

A multicenter, nonrandomized study evaluated 124 women with low-risk palpable lesions. Lesions <or=1.5 cm and those >1.5 cm but <or=3.0 cm were removed using 1-gauge or 8-gauge probes, respectively. Follow-up evaluation was performed at 10 days postbiopsy.

RESULTS

The 8-guage probe was used to obtain biopsies from 75 patients, and the 11-gauge was used for 49 patients. Complete removal of the imaged lesion was similar between groups (99% 8-gauge versus 96% 11-gauge). Most complications were mild and anticipated. Most patients (97%) were satisfied with incision appearance, and 98% of patients would recommend the procedure to others.

CONCLUSIONS

Percutaneous removal of palpable benign breast masses using the Mammotome system is feasible, safe, and yields high patient satisfaction. Long-term efficacy is being evaluated in the ongoing study.

Specific up-regulation of GADD153/CHOP in 1-methyl-4-phenyl-pyridinium-treated SH-SY5Y cells

Growth arrest DNA damage-inducible 153 (GADD153) expression was increased in 1-methyl-4-phenyl-pyridinium (MPP(+))-treated human SH-SY5Y neuroblastoma cells as determined by gene microarray analysis. GADD153 expression increased after 24 hr of MPP(+) (1 mM) exposure and preceded activation of caspase 3. Comparison of GADD153 expression among cultures treated with other toxins whose primary mode of action is either via mitochondrial impairment (rotenone) or via oxidative stress (6-hydroxydopamine or hydrogen peroxide) showed that GADD153 was uniquely up-regulated by MPP(+). Together these data suggest that a cellular mechanism distinct from mitochondrial impairment or oxidative stress contributes significantly to the up-regulation of GADD153 by MPP(+) and that GADD153 may function as an inducer of apoptosis following MPP(+) exposure. Published 2002 Wiley-Liss, Inc.

Amyloid beta binds trimers as well as monomers of the 75-kDa neurotrophin receptor and activates receptor signaling

p75(NTR), a nerve growth factor co-receptor that has been implicated in apoptosis of neurons, is structurally related to Fas and the receptors for tumor necrosis factor-alpha that display ligand independent assembly into trimers. Using embryonic day 17 fetal rat cortical neurons and p75(NTR)-expressing NIH-3T3 cells, we now show that p75(NTR) exists as a trimer as well as a monomer. Furthermore, we have reported and others have confirmed that amyloid beta binds p75(NTR), and that this binding leads to apoptotic cell death. We now report that amyloid beta binds to trimers of p75(NTR) as well as to p75(NTR) monomers but not to the p140(trkA), the nerve growth factor co-receptor that mediates neuronal survival. Furthermore, amyloid beta activates p75(NTR), strongly inducing the transcription of c-Jun mRNA and stimulating the stress-activated c-Jun NH(2)-terminal kinase, as measured by phosphorylation of its substrate (glutathione S-transferase-c-Jun-(1-79)). Our data suggest that p75(NTR) may be present as a preformed trimer that binds amyloid beta to induce receptor activation, and support the hypothesis that p75(NTR) activation by amyloid beta is causally related to Alzheimer's disease.

A prospective study of the removal rate of imaged breast lesions by an 11-gauge vacuum-assisted biopsy probe system

BACKGROUND

More than 1,000,000 breast biopsies are performed each year as a result of abnormalities identified by imaging techniques. This prospective study was designed to determine whether complete removal of the imaged evidence of an abnormal mammogram or ultrasonogram could be achieved with percutaneous image-guided procedures using an 11-gauge vacuum-assisted biopsy probe.

METHODS

Forty-five women over the age of 18 years entered the study; 50 breast lesions were identified by ultrasonography or mammography. Biopsies were obtained using an 11-gauge vacuum-assisted probe. At 6 months after biopsy, ultrasonography or mammography examinations of the biopsy site were performed.

RESULTS

Forty-five lesions (90%) were completely removed. At 6 months after biopsy, 82% of the sites were lesion free. The percentage of nonrecurring lesions at 6 months after surgery was inversely related to the size of the original lesion.

CONCLUSION

This device allows biopsies to be successfully combined with complete removal of the imaged lesion in a one-step minimally invasive procedure.

Decreased expression of the NADH:ubiquinone oxidoreductase (complex I) subunit 4 in 1-methyl-4-phenylpyridinium -treated human neuroblastoma SH-SY5Y cells

Oxidative stress and mitochondrial dysfunction have been implicated in Parkinson's disease (PD) pathology. NADH:ubiquinone oxidoreductase (complex I) (EC 1.6.99.3) enzyme activity is aberrant in both PD and 1-methyl-4-phenylpyridinium (MPP(+)) models of PD. Reverse transcription polymerase chain reaction of RNA isolated from MPP(+)-treated human neuroblastoma SH-SY5Y cells identified changes in steady-state mRNA levels of the mitochondrial transcript for subunit 4 of complex I (ND4). Expression of ND4 decreased to nearly 50% after 72 h of MPP(+) (1 mM) exposure. The expression of other mitochondrial transcripts did not change significantly under the same conditions. Pre-incubation of cells with the free-radical spin-trap, N-tert-butyl-alpha-(2-sulfophenyl)-nitrone prior to MPP(+) exposure, prevented decreases in cell viability and ND4 expression. This suggests that functional defects in complex I enzyme activity in PD and MPP(+) toxicity may result from changes in steady-state mRNA levels and that free radicals may be important in this process.

Calreticulin functions as a molecular chaperone for the β-amyloid precursor protein 1 1Abbreviations used: Aβ, β-amyloid peptide; AD, Alzheimer’s disease; APP, β-amyloid precursor protein; CHAPS, 3-[(3-Cholamidopropyl)-dimethylammonio]-1-propanesulfonate; Crt, calreticulin; DMEM, Dulbecco’s Modified Eagle Medium; DMJ, deoxymannojirimycin; DTSSP, 3,3′-Dithio bis (sulfosuccinimidylpropionate); ECL, Enhanced Chemiluminescence; ER, endoplasmic reticulum; FBS, fetal bovine serum; HRP, horseradish peroxidase; kDa, kiloDaltons; MES, 2-(N-Morpholino) ethane sulfonic acid; NRS, normal rabbit serum; PBS, PBS; PMSF, phenymethylsulfonyl fluoride; PVDF, polyvinylidene fluoride

Processing of the beta-amyloid precursor protein (APP) in the endoplasmic reticulum and the Golgi apparatus may be critical in generating the beta-amyloid molecules linked to the pathogenesis of Alzheimer's disease. Since chaperone molecules such as calreticulin (Crt) have been shown to be important in the maturation of many glycoproteins, we investigated the interaction between Crt and APP. We show that APP binds transiently to Crt in a manner that is pH, divalent cation, and N-linked glycosylation-dependent. Both immature APP (containing only N-linked sugars) and mature APP (containing both N-linked and O-linked sugars) bind to Crt. Both proteins are part of a complex that appears to be large enough to accommodate other proteins as well. However, while most of the immature form is associated with the complexes, very little of the mature form is. The interaction between APP and Crt is likely to be of physiological significance with respect to APP maturation since Crt is involved in quality control of nascent glycoproteins in the secretory pathway.

Postmastectomy radiotherapy: clinical practice guidelines of the American Society of Clinical Oncology

OBJECTIVE

To determine indications for the use of postmastectomy radiotherapy (PMRT) for patients with invasive breast cancer with involved axillary lymph nodes or locally advanced disease who receive systemic therapy. These guidelines are intended for use in the care of patients outside of clinical trials.

POTENTIAL INTERVENTION

The benefits and risks of PMRT in such patients, as well as subgroups of these patients, were considered. The details of the PMRT technique were also evaluated.

OUTCOMES

The outcomes considered included freedom from local-regional recurrence, survival (disease-free and overall), and long-term toxicity.

EVIDENCE

An expert multidisciplinary panel reviewed pertinent information from the published literature through July 2000; certain investigators were contacted for more recent and, in some cases, unpublished information. A computerized search was performed of MEDLINE data; directed searches based on the bibliographies of primary articles were also performed.

VALUES

Levels of evidence and guideline grades were assigned by the Panel using standard criteria. A "recommendation" was made when level I or II evidence was available and there was consensus as to its meaning. A "suggestion" was made based on level III, IV, or V evidence and there was consensus as to its meaning. Areas of clinical importance were pointed out where guidelines could not be formulated due to insufficient evidence or lack of consensus.

RECOMMENDATIONS

The recommendations, suggestions, and expert opinions of the Panel are described in this article.

VALIDATION

Seven outside reviewers, the American Society of Clinical Oncology (ASCO) Health Services Research Committee members, and the ASCO Board of Directors reviewed this document.

Tumor necrosis factor alpha increases human cerebral endothelial cell Gb3 and sensitivity to Shiga toxin

Hemolytic uremic syndrome (HUS) is associated with intestinal infection by enterohemorrhagic Escherichia coli strains that produce Shiga toxins. Globotriaosylceramide (Gb3) is the functional receptor for Shiga toxin, and tumor necrosis factor alpha (TNF-alpha) upregulates Gb3 in both human macrovascular umbilical vein endothelial cells and human microvascular brain endothelial cells. TNF-alpha treatment enhanced Shiga toxin binding and sensitivity to toxin. This upregulation was specific for Gb3 species containing normal fatty acids (NFA). Central nervous system (CNS) pathology in HUS could involve cytokine-stimulated elevation of endothelial NFA-Gb3 levels. Differential expression of Gb3 species may be a critical determinant of Shiga toxin toxicity and of CNS involvement in HUS.

Isolation and characterization of substance P-containing dense core vesicles from rabbit optic nerve and termini

In neurons, neuropeptides and other synaptic components are transported down the axon to the synapse in vesicles using molecular motors of the kinesin family. In the synapse, these neuropeptides are found in dense core vesicles (DCVs), and, following calcium-mediated exocytosis, they interact with receptors on the target cell. We have developed a rapid, large-scale technique for purifying peptide-containing DCVs from specific nuclei in the central nervous system. By using differential velocity gradient and equilibrium gradient centrifugation, neuropeptide-containing DCVs can be separated by size and density from optic nerve (ON) and its termini, the lateral geniculate nuclei and the superior colliculi. Isolated DCVs contain neuropeptides (substance P and brain-derived neurotrophic factor), synaptic vesicle (SV) membrane proteins (SV2, synaptotagmins, synaptophysin, Rab3 and synaptobrevin), SV-associated proteins (alpha-synuclein), secretory markers for DCVs previously isolated (secretogranin II), and beta-amyloid precursor protein. By using electron microscopic techniques, DCV were also visualized and shown to be immunoreactive for neuropeptides, neurotrophins, and SV membrane proteins. Because of the interesting group of physiological and potentially pathophysiological proteins associated with these vesicles; this isolation procedure, applicable to other CNS nuclei, should represent an important research tool.

Beta amyloid fragments derived from activated platelets deposit in cerebrovascular endothelium: usage of a novel blood brain barrier endothelial cell model system

Amyloid precursor protein (A betaPP) processing results in generation of amyloid beta peptide (A beta) which deposits in the brain parenchyma and cerebrovasculature of patients with Alzheimer's disease (AD). Evidence that the vascular deposits derive in part from A betaPP fragments originating from activated platelets includes findings that individuals who have had multiple small strokes have a higher prevalence of AD compared to individuals who have taken anti-platelet drugs. Thus, determination of whether platelet A betaPP fragments are capable of traversing the blood-brain barrier (BBB) is critical. We have established that activated platelets from patients with AD retain more surface transmembrane-bound A betaPP (mA betaPP) than control platelets. We report here that this mA betaPP can be cleaved to A beta-containing fragments which pass through a novel BBB model system. This model utilizes human BBB endothelial cells (BEC) isolated from brains of patients with AD. These BEC, after exposure to activated platelets which have been surface-labeled with fluorescein and express surface-retained mA betaPP, cleave fluorescein-tagged surface proteins, including mA betaPP, resulting in passage to the BEC layer The data confirm that BEC contribute to processing of platelet-derived mA betaPP and show that the processing yields A beta containing fragments which could potentially contribute to cerebrovascular A beta deposition.

Antisense oligonucleotide sequences targeting the muscarinic type 2 acetylcholine receptor enhance performance in the Morris water maze

Blocking autoinhibitory muscarinic type 2 (m2) acetylcholine receptors in the central nervous system may increase the release of acetylcholine and improve learning and memory. Antisense oligonucleotides (OGNs) complementary to m2 receptor mRNA were synthesized and evaluated for their efficacy at decreasing receptor number and reversing deficits in a cognitive task. Three antisense OGNs, which decreased m2 receptor binding in NG108-15 cells, were continuously infused into the lateral cerebral ventricle of rats for 6 days at a rate of 0.5 micro1/h and a daily dose of 72 microg. Performance in the Morris water maze was compared to groups receiving control OGNs or vehicle alone. Decrements induced by 0.2 mg/kg of scopolamine i.p. were significantly reversed by 2 of the 3 antisense OGNs. Use of antisense OGNs targeting the m2 receptor may be a new strategy to increase cholinergic neurotransmission and improve learning and memory.

Toxicity of various amyloid beta peptide species in cultured human blood-brain barrier endothelial cells: increased toxicity of dutch-type mutant

The amyloid beta peptide (A beta) is the major component of the neuritic and cerebrovascular amyloid plaques that are one of the characteristic features of Alzheimer's disease (AD). This peptide has been shown to be toxic to several relevant cell types, including neurons, cerebrovascular smooth muscle cells, and endothelial cells. We have studied the toxic effects of both soluble and aggregated species of A beta(1-40) and the mutation A beta(1-40)Glu-->Gln(22), which is the major species deposited in the cerebrovascular blood vessels of victims of hereditary cerebral hemorrhage with amyloidosis, Dutch type. We find that aggregates of both peptides, as well as of A beta(1-42) and A beta(25-35), are toxic to cultured human cerebrovascular endothelial cells (hBEC) obtained from the brain of a victim of AD (at doses lower than those that are toxic to CNS neurons or leptomeningeal smooth muscle cells). Soluble A beta(1-40) Gln(22) is equally toxic to hBEC, whereas wild-type A beta(1-40) is toxic only at higher doses. This toxicity is seen at the lowest dose of A beta(1-40) Gln (22) used, 20 nM. The soluble A beta(1-40)Gln(22) aggregates on the surface of the cells, in contrast to A beta(1-40), and its toxicity can be blocked both by an inhibitor of free radical formation and by Congo red, which inhibits amyloid fibril formation. We discuss the possibility that the enhanced toxicity of A beta(1-40)Gln(22) is mediated by a A beta receptor on the endothelial cells.

Serum amyloid A is present in the capillaries and microinfarcts of hypertensive monkey brain: an immunohistochemical study

Serum amyloid A (SAA) is a major inducible acute phase protein characterized as a transient injury specific constituent of high density lipoprotein. We investigated whether the acute phase SAA (A-apoSAA), as a marker of inflammation, is present in the brain of monkeys with surgically induced hypertension of 39 months duration. Sections from brains of normotensive monkeys (systolic blood pressure < 124 mmHg) and hypertensive monkeys (systolic blood pressure > 185 mmHg) were processed for immunohistochemistry with a rabbit polyclonal antiserum to human A-apoSAA. We found that A-apoSAA was present in hypertensive but not in normotensive brain sections. Staining was localized to capillary endothelial cells and occasionally to the entire vessel wall of the prefrontal cortex. Staining was also observed in the capillaries and in medium size vessels of the corona radiata, the head of the caudate and, to a smaller extent, in the putamen. Additionally, the A-apoSAA was present in cells forming a circular configuration within microinfarcts. These findings suggest that high blood pressure in the brain can result in either local production of A-apoSAA in the capillaries and within microinfarcts or uptake of A-apoSAA from the blood

Serum amyloid A in Alzheimer's disease brain is predominantly localized to myelin sheaths and axonal membrane

Immunohistochemical localization of the injury specific apolipoprotein, acute phase serum amyloid A (A-apoSAA), was compared in brains of patients with neuropathologically confirmed Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD); Pick's disease (Pick's), dementia with Lewy bodies (DLB), coronary artery disease (CAD), and schizophrenia. Affected regions of both AD and MS brains showed intense staining for A-apoSAA in comparison to an unaffected region and non-AD/MS brains. The major site of A-apoSAA staining in both diseases was the myelin sheaths of axons in layers V and VI of affected cortex. A-apoSAA contains a cholesterol binding site near its amino terminus and is likely to have a high affinity for cholesterol-rich myelin. These findings, along with our recent evidence that A-apoSAA can inhibit lipid synthesis in vascular smooth muscle cells suggest that A-apoSAA plays a role in the neuronal loss and white matter damage occurring in AD and MS.