PolyQ-Expanded Mutant Huntingtin Forms Inclusion Body Following Transient Cold Shock in a Two-Step Aggregation Mechanism

Age-dependent formation of insoluble protein aggregates is a hallmark of many neurodegenerative diseases. We are interested in the cell chemistry that drives the aggregation of polyQ-expanded mutant Huntingtin (mHtt) protein into insoluble inclusion bodies (IBs). Using an inducible cell model of Huntington's disease, we show that a transient cold shock (CS) at 4 °C followed by recovery incubation at temperatures of 25-37 °C strongly and rapidly induces the compaction of diffuse polyQ-expanded HuntingtinExon1-enhanced green fluorescent protein chimera protein (mHtt) into round, micron size, cytosolic IBs. This transient CS-induced mHtt IB formation is independent of microtubule integrity or de novo protein synthesis. The addition of millimolar concentrations of sodium chloride accelerates, whereas urea suppresses this transient CS-induced mHtt IB formation. These results suggest that the low temperature of CS constrains the conformation dynamics of the intrinsically disordered mHtt into labile intermediate structures to facilitate de-solvation and hydrophobic interaction for IB formation at the higher recovery temperature. This work, along with our previous observation of the effects of heat shock protein chaperones and osmolytes in driving mHtt IB formation, underscores the primacy of mHtt structuring and rigidification for H-bond-mediated cross-linking in a two-step mechanism of mHtt IB formation in living cells.

HSF1, Aging, and Neurodegeneration

Heat shock factor 1 (HSF1) is a master transcription regulator that mediates the induction of heat shock protein chaperones for quality control (QC) of the proteome and maintenance of proteostasis as a protective mechanism in response to stress. Research in this particular area has accelerated dramatically over the past three decades following successful isolation, cloning, and characterization of HSF1. The intricate multi-protein complexes and transcriptional activation orchestrated by HSF1 are fundamental processes within the cellular QC machinery. Our primary focus is on the regulation and function of HSF1 in aging and neurodegenerative diseases (ND) which represent physiological and pathological states of dysfunction in protein QC. This chapter presents an overview of HSF1 structural, functional, and energetic properties in healthy cells while addressing the deterioration of HSF1 function viz-à-viz age-dependent and neuron-specific vulnerability to ND. We discuss the structural domains of HSF1 with emphasis on the intrinsically disordered regions and note that disease proteins associated with ND are often structurally disordered and exquisitely sensitive to changes in cellular environment as may occur during aging. We propose a hypothesis that age-dependent changes of the intrinsically disordered proteome likely hold answers to understand many of the functional, structural, and organizational changes of proteins and signaling pathways in aging - dysfunction of HSF1 and accumulation of disease protein aggregates in ND included.Structured AbstractsIntroduction: Heat shock factor 1 (HSF1) is a master transcription regulator that mediates the induction of heat shock protein chaperones for quality control (QC) of the proteome as a cyto-protective mechanism in response to stress. There is cumulative evidence of age-related deterioration of this QC mechanism that contributes to disease vulnerability.

OBJECTIVES

Herein we discuss the regulation and function of HSF1 as they relate to the pathophysiological changes of protein quality control in aging and neurodegenerative diseases (ND).

METHODS

We present an overview of HSF1 structural, functional, and energetic properties in healthy cells while addressing the deterioration of HSF1 function vis-à-vis age-dependent and neuron-specific vulnerability to neurodegenerative diseases.

RESULTS

We examine the impact of intrinsically disordered regions on the function of HSF1 and note that proteins associated with neurodegeneration are natively unstructured and exquisitely sensitive to changes in cellular environment as may occur during aging.

CONCLUSIONS

We put forth a hypothesis that age-dependent changes of the intrinsically disordered proteome hold answers to understanding many of the functional, structural, and organizational changes of proteins - dysfunction of HSF1 in aging and appearance of disease protein aggregates in neurodegenerative diseases included.

Dexmedetomidine infusion for sedation in a patient with myotonic dystrophy

Myotonic dystrophy type 1 is the most common muscular dystrophy in adults. Anaesthetic management should take into consideration the numerous body systems affected, including the musculoskeletal; respiratory; cardiovascular; gastro-intestinal; and central nervous systems. A 42-year-old man with myotonic dystrophy presented for septoplasty and bilateral inferior turbinate reductions. He had severe upper and lower extremity myotonia and weakness, pulmonary impairment with non-obstructive patterns and first-degree atrioventricular block with reduced ejection fraction. He used bilevel positive airway pressure, a cough assist device and was paced 3% of the time with a single-chamber pacemaker. To reduce potential complications associated with opioid use and general anaesthetics, an opioid-free technique was planned using local anaesthetic infiltration and sedation with a dexmedetomidine infusion. The patient maintained spontaneous ventilation and haemodynamic stability, and had an uneventful postoperative course. Dexmedetomidine is a highly selective α2-adrenergic receptor agonist that has the ability to provide sedation, analgesia and anxiolysis with a stable haemodynamic profile. Avoiding both opioids and general anaesthetics in these patients may decrease the risk of peri-operative complications.

Maternal plasma and breastmilk viral loads are associated with HIV-1-specific cellular immune responses among HIV-1-exposed, uninfected infants in Kenya

Infants exposed to maternal HIV-1 provide an opportunity to assess correlates of HIV-1-specific interferon (IFN)-γ responses and may be informative in the development of HIV-1 vaccines. HIV-1-infected women with CD4 counts 200-500 cells/mm(3) were randomized to short-course zidovudine/nevirapine (ZDV/NVP) or highly active anti-retroviral therapy (HAART) between 2003 and 2005. Maternal plasma and breastmilk HIV-1 RNA and DNA were quantified during the first 6-12 months postpartum. HIV-1 gag peptide-stimulated enzyme-linked immunospot (ELISPOT) assays were conducted in HIV-1-exposed, uninfected infants (EU), and correlates were determined using regression and generalized estimating equations. Among 47 EU infants, 21 (45%) had ≥1 positive ELISPOT result during follow-up. Infants had a median response magnitude of 177 HIV-1-specific spot-forming units (SFU)/106 peripheral blood mononuclear cells (PBMC) [interquartile range (IQR)=117-287] directed against 2 (IQR = 1-3) gag peptide pools. The prevalence and magnitude of responses did not differ by maternal anti-retroviral (ARV) randomization arm. Maternal plasma HIV-1 RNA levels during pregnancy (P=0.009) and breastmilk HIV-1 DNA levels at 1 month (P=0.02) were associated with a higher magnitude of infant HIV-1-specific ELISPOT responses at 1 month postpartum. During follow-up, concurrent breastmilk HIV-1 RNA and DNA (cell-free virus and cell-associated virus, respectively) each were associated positively with magnitude of infant HIV-1-specific responses (P=0.01). Our data demonstrate the importance of antigenic exposure on the induction of infant HIV-1-specific cellular immune responses in the absence of infection.

Maturation of mast cell progenitors to mucosal mast cells during allergic pulmonary inflammation in mice

In contrast to resident constitutive mast cells (CMCs), mucosal MCs (MMCs) appear in the lung and trachea of sensitized mice only following inhalation challenge. We monitored the influx and maturation of MCs by their expression of Kit, FcɛRI, β7-integrin and side scatter (SSC) by flow cytometry. Influx of MC progenitors (MCps) (FcɛRI(lo), Kit(int), β7(hi), and SSC(lo)) peaks 1 day after challenges and subsides to baseline by day 7 after challenge. The mature MMCs appear as a distinct population on day 7 and peak at day 14 with higher SSC and FcɛRI expression, but lower β7 and Kit expression. A distinct transitional population is present between 1 and 7 days after challenge. Maturation occurs more rapidly in the trachea. The resident tracheal CMCs had higher SSC, FcɛRI, and Kit and lower β7-integrin expression than the MMCs. By histology, the MMCs follow similar kinetics to the flow cytometry-identified mature MMCs and are notably persistent for >42 days. Steroid treatment reduced inflammation and MCp influx but had no effect on established MMCs. Thus, changes in SSC, FcɛRI, and Kit together with the expression of αE/α4:β7-integrins characterizes the development of induced MMCs from MCps and distinguishes them from resident CMCs in the trachea and large airways.

[Interaction of DAXX and human papillomavirus type 16 E2 protein]

The aim of the study was to explore the interactions of human papilloma virus 16 (HPV16) E2 protein and Daxx. The location or co-localization of PML and E2 with Daxx in Caski cells was observed by indirect immunofluorescence test. The interaction of E2 and Daxx was analyzed by co-immunoprecipitation, Western-blot and yeast-two hybrid assay. In Caski cells the fluorescence of Daxx or PML was mainly distributed in the cytoplasm or nucleus, respectively, and in the align image their signals did not overlapped. However, when the red signal of HPV16 E2 and the green signal of Daxx in cyto- plasm of Caski cells were merged, the yellow signals appeared. The yeast co-transformed with pGBKT7/Daxx and pGADT7/E2 or pGADT7/E2 TAD can grow onto SD/-Trp-Leu-His and SD/-Trp-Leu-His-Ade plates. So Daxx wasn't co-located with PML but with HPV16 E2 mainly in the cytoplasm of Caski cells. On the base of the results one can propose that HPV16 E2, in particularly its transcription-activity domain (TAD), interacts with Daxx.

First Report of Gliocephalotrichum bulbilium Causing Fruit Rot of Posthavest Mangosteen in China

Mangosteen (Garcinia mangostana L., Guttiferae) is a tropical fruit renowned for its pleasant taste, rich nutrition, and medicinal value. Little research about mangosteen diseases during storage and transport has been reported. In June of 2012, fruit rots on mangosteens imported from Thailand were observed in Guangzhou, China. In infected fruits, pericarps showed an increased firmness, were discolored to deep pink, and the edible aril became brown and rotten. In order to search for the etiological agent of this rot symptom, infected mangosteens were analyzed. Diseased mangosteen tissues were surface-sterilized with 70% alcohol, then with 0.1% HgCl₂, dipped in sterilized water three times, and placed onto potato dextrose agar (PDA) at 26°C. The fungi isolated from tissues of the pericarp and aril were similar in morphology and grew rapidly, covering the plate surface (9 mm diameter) after 2 to 3 days of incubation at 26°C. The morphological characters of 10 single-spore isolates were observed. These isolates showed light yellow to light brown fertile colonies on PDA. On corn meal agar (CMA), conidiophores were erect, arising from wide hyphae; they were composed of a basal stipe ending in a penicillate conidiogenous apparatus with directly subtending sterile stipe extensions ranging from 74.5 to 195.0 μm long. Conidia were unicellular, smooth, oblong to elliptical, 6.3 to 8.5 × 2.5 to 3.0 μm, and accumulated in a mucilaginous mass. Chlamydospores were multicellular, dark brown, regular in shape and thick-walled, and 40.0 to 52.5 μm in diameter. On the basis of these morphological characters, these isolates were identified as Gliocephalotrichum bulbilium (2). To confirm the identity of this fungus, genomic DNA of two isolates was extracted, and fragments of ITS region and β-tubulin gene were amplified by PCR, sequenced, and compared with sequences of Gliocephalotrichum species available in NCBI GenBank. Both DNA regions (GenBank Accession Nos. KF716166 and KF716168) had sequence similarities of 99% and 97%, respectively, to other G. bulbilium sequences at GenBank. Pathogenicity tests were conducted on three detached fruits for two isolates. Fruits were inoculated using 5-mm mycelial disks with conidia taken from 3-day-old cultures of G. bulbilium isolate Gb1 and Gb10 grown on PDA. Controls were inoculated with PDA disks only. All treated fruits were kept individually in a humid chamber at 26°C. Tests were repeated twice. Three days after inoculation, white mycelial growth for Gb was observed at inoculation sites. Eight days after inoculation, mycelium of Gb nearly covered the fruit, causing fruit rot, and the pericarp became hard and light in color. The control fruit did not rot. G. bulbilium was re-isolated from diseased plant tissue, thus fulfilling Koch's postulates. G. bulbilium has been reported causing postharvest fruit rot of rambutan (Nephelium lappaceum) and guava (Psidium guajava) in some locations (3,4). Moreover, the fungus caused cranberry fruit rot in the United States (1). To our knowledge, this is the first report of G. bulbilium causing postharvest fruit rot of mangosteen in China. It is uncertain whether the fungus infected mangosteen in Thailand and was carried to China due to commercial relationship. References: (1) C. Constantelos et al. Plant Dis. 95:618, 2011. (2) C. Decock et al. Mycologia 98:488, 2006. (3) L. M. Serrato-Diaz et al. Plant Dis. 96:1225, 2012. (4) A. Sivapalan et al. Australas. Plant Pathol. 27:274, 1998.

Nonequilibrium "melting" of a charge density wave insulator via an ultrafast laser pulse

We employ an exact solution of the simplest model for pump-probe time-resolved photoemission spectroscopy in charge-density-wave systems to show how, in nonequilibrium, the gap in the density of states disappears while the charge density remains modulated, and then the gap reforms after the pulse has passed. This nonequilibrium scenario qualitatively describes the common short-time experimental features in TaS(2) and TbTe(3), indicating a quasiuniversality for nonequilibrium "melting" with qualitative features that can be easily understood within a simple picture.

Helping our patients take HIV pre-exposure prophylaxis (PrEP): a systematic review of adherence interventions

OBJECTIVES

Adherence is critical for maximizing the effectiveness of pre-exposure prophylaxis (PrEP) in preventing HIV infection. Strategies for promoting adherence to HIV treatment, and their potential application to PrEP adherence, have received considerable attention. However, adherence promotion strategies for prevention medications have not been well characterized and may be more applicable to PrEP. We aimed to identify adherence support interventions that have been effective in other prevention fields and could be applied in the HIV prevention context to support pill taking among PrEP users.

METHODS

To identify adherence support interventions that could be evaluated and applied in the PrEP context, we conducted a systematic review across the following prevention fields: hypertension, latent tuberculosis infection, hyperlipidaemia, oral contraceptives, osteoporosis, malaria prophylaxis, and post-exposure prophylaxis for HIV infection. We included randomized controlled trials that evaluated the efficacy of interventions to improve adherence to daily oral medications prescribed for primary prevention in healthy individuals or for secondary prevention in asymptomatic individuals.

RESULTS

Our searches identified 585 studies, of which 48 studies met the eligibility criteria and were included in the review; nine evaluated multiple strategies, yielding 64 separately tested interventions. Interventions with the strongest evidence for improving adherence included complex, resource-intensive interventions, which combined multiple adherence support approaches, and low-cost, low-intensity interventions that provided education or telephone calls for adherence support.

CONCLUSIONS

Our review identified adherence interventions with strong evidence of efficacy across prevention fields and provides recommendations for evaluating these interventions in upcoming PrEP studies.

Pulsed laser assisted reduction of graphene oxide as a flexible transparent conducting material

In this paper, we use a simple and highly-effective pulsed laser reducing method to fabricate flexible, transparent and conducting graphene film. The pulsed laser reducing process was monitored by digital camera and UV-visible spectroscopy. The obtained reduced graphene oxide (r-GO) was characterized by Raman spectroscopy. Based on this reducing method, the resulting r-GO films possessed a transmittance varied from 29% to 74% and a sheet resistance varied from 2.1 MΩ/[square] to 840 Ω/[square], which was very close to chemically r-GO film.

Sjögren's syndrome in dermatology

Sjogren's Syndrome (SS) is a systemic autoimmune disease characterized by dry eyes (keratoconjunctivis sicca) and dry mouth (xerostomia). To fulfill diagnostic criteria, patients must have objective signs of dryness on examination and laboratory confirmation of an autoimmune process as evidenced by a positive autoantibody to SS-A antigen or a characteristic lip biopsy. SS may exist as a primary condition or in association with other systemic autoimmune disorders (termed secondary SS) such as rheumatoid arthritis, systemic lupus erythematous (SLE), progressive systemic sclerosis (scleroderma), or dermatomyositis. Exclusions to the diagnosis include pre-existing lymphoma, hepatitis C or HIV infection. Pathogenesis involves both genetic (especially HLA-DR) and environmental factors. Both T-cells and B-cells are involved in the generation of cytokines and chemokines within the glands. The epithelial cells of the glands also play a role in pathogenesis. The dermatologic manifestations range from drynessness (sicca) and its complications to vasculitis. There is a significant overlap in the clinical manifestations, as well as treatment, of SS and SLE. However, SS patients require special attention to the complications of ocular dryness (keratocojunctivitis sicca and blepharitis) and oral dryness (rapid tooth loss and oral candidiasis) SS patients have a markedly increased risk of lymphoma and enlarged lymph nodes or persistently enlarged parotid/submandibular glands that require further evaluation.

[Redox-dependent changes in structure and function of hHSF1]

To evaluate the effects of cysteine-SH-directed regents on the redox status, structure and function of human heat shock transcription factor 1 (hHSF1), treatment in vitro of hHSF1 with 0.3 0.5 mmol/L oxidizing reagent diamide (DM) and treatment in vivo of HeLa cells with 1 mmol/L buthionine sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, promoted the formation of a compact, intramolecularly disulfide-crosslinked, stable monomeric form of ox-hHSF1, and blocked the trimerization and activation of HSF1. The effects of diamine were dose-dependent and readily could be completely reversed by adding 0.4 0.5 mmol/L reducing reagent dithiothreitol (DTT) to the samples prior to gel electrophoresis. Computer modeling of the alpha-helical coiled-coil domains of the HSF1 monomer and trimer showed that the alignment of the N- and C-terminal hydrophobic repeats of HSF1 monomer could bring C(3)(Cys(153))close to C(4) and C(5)(Cys(373) and Cys(378), respectively), in positions permissible for disulfide bond formation under appropriate experimental conditions. The results suggest that redox-dependent thiol-disulfide exchange can provide a mechanism for regulation the conformation and activity of hHSF1.

JNK phosphorylates the HSF1 transcriptional activation domain: role of JNK in the regulation of the heat shock response

The role of c-Jun NH2-terminal kinase (JNK) signaling cascade in the stress-inducible phosphorylation of heat shock factor 1 (HSF1) was investigated using known agonists and antagonists of JNK. We showed that treatment of HeLa cells with MG132, a proteasome inhibitor and known INK activator, caused the transcriptional activation domain of HSF1 to be targeted and phosphorylated by JNK2 in vivo. Dose-response and time course studies of the effects of heat shock and anisomycin treatment showed a close correlation of the activation of JNK and hyperphosphorylation of HSF1. SB203580 inhibited INK at the 100 microM concentration and significantly reduced the amount of hyperphosphorylated HSF1 upon heat shock or anisomycin treatment. SB203580 and dominant-negative JNK suppress hsp70 promoter-driven reporter gene expression selectively at 45 degrees C but not at 42 degrees C heat stress, suggesting that JNK would be preferentially associated with the protective heat shock response against severe heat stress. The possibility that JNK-mediated phosphorylation of HSF1 may selectively stabilize the HSF1 protein and confers protection to cells under conditions of severe stress is discussed.

Human beta-defensin-2 production in keratinocytes is regulated by interleukin-1, bacteria, and the state of differentiation

Intact human epidermis resists invasion by pathogenic microbes but the biochemical basis of its resistance is not well understood. Recently, an antimicrobial peptide, human beta-defensin-2, was discovered in inflamed epidermis. We used a recombinant baculovirus/insect cell system to produce human beta-defensin-2 and confirmed that at micromolar concentrations it has a broad spectrum of antimicrobial activity, with the striking exception of Staphylococcus aureus. Immunostaining with a polyclonal antibody to human beta-defensin-2 showed that the expression of human beta-defensin-2 peptide by human keratinocytes required differentiation of the cells (either by increased calcium concentration or by growth and maturation in epidermal organotypic culture) as well as a cytokine or bacterial stimulus. Interleukin-1alpha, interleukin-1beta, or live Pseudomonas aeruginosa proved to be the most effective stimuli whereas other bacteria and cytokines had little or no ability to induce human beta-defensin-2 synthesis. In interleukin-1alpha-stimulated epidermal cultures, human beta-defensin-2 first appeared in the cytoplasm in differentiated suprabasal layers of skin, next in a more peripheral web-like distribution in the upper layers of the epidermis, and then over a few days migrated to the stratum corneum. By semiquantitative Western blot analysis of epidermal lysates, the average concentration of human beta-defensin-2 in stimulated organotypic epidermal culture reached 15--70 microg per gram of tissue, i.e., 3.5-16 microM, well within the range required for antimicrobial activity. Because of the restricted pattern of human beta-defensin-2 distribution in the epidermis, its local concentration must be much higher. Defensins and other antimicrobial peptides of inflamed epidermis are likely to play an important antimicrobial role in host defense against cutaneous pathogens.

Chromosome 11 copy number gains and Epstein-Barr virus-associated malignancies

Epstein-Barr virus (EBV) genome can be found in many malignant tumors in China. Previous data of interphase cytogenetics, by comparative genomic hybridization and/or fluorescence in situ hybridization, on nasopharyngeal carcinomas and natural killer cell-type non-Hodgkin lymphomas in Hong Kong have noted gains in chromosome 11. This study compares the frequency of chromosome 11 copy number gains in three different types of EBV-associated tumors in Hong Kong. Using alpha-satellite probes, the authors studied by fluorescence in situ hybridization 31 EBV-positive tumors comprising 10 EBV-positive gastric carcinomas, 8 lung lymphoepithelioma-like carcinomas, and 13 non-Hodgkin lymphomas. Trisomy or polysomy 11 was detected in 10 of 10 (100%) EBV-positive gastric carcinomas, 6 of 8 (75%) lung lymphoepithelioma-like carcinomas, and 4 of 13 (30.8%) non-Hodgkin lymphomas. Compared with the EBV-positive gastric carcinomas, the 10 EBV-negative gastric carcinomas that were also studied showed chromosome 11 copy number gains in 3 of 10 (30%), a significantly lower frequency. The authors conclude that gains in chromosome 11 are common in EBV-associated malignancies in Hong Kong, with the strongest association found in gastric carcinoma. There seems to be differences between EBV-associated tumors of different locations, and between gastric carcinomas with and without EBV.

Diffusion-weighted imaging in the evaluation of watershed hypoxic-ischemic brain injury in pediatric patients

The purpose of our study was to determine the usefulness of echo-planar diffusion-weighted imaging (EPDI) in the evaluation of watershed hypoxic-ischemic brain injury in pediatric patients. Eighteen patients ranging in age from 3 weeks to 12 years were evaluated for evidence of ischemic/infarction changes on conventional MR and EPDI. Included in the study group were five patients with sickle cell disease, four with congenital heart disease, four with hypotensive episodes with various etiologies, three with sepsis, and two with encephalitis or meningitis. Patients were examined 2 h to 6 days after the initial insult, with follow-up studies in four patients at 1 to 62 days after the initial examination. After conventional MR imaging (T1, FSE T2, and FLAIR), diffusion-weighted MR imaging was performed using high-speed, single-shot EP techniques with TR 6000, TE 144, matrix 96 x 128, FOV 23.3 x 31 and five b values of 0, 160, 360, 640, and 1,000 s/mm2. EPDI demonstrated abnormally increased signal in watershed ischemic/infarction zones in all initial cases. Apparent diffusion coefficients (ADC) were obtained in 59 lesions. When compared with radiographically normal (on EPDI) contralateral brain parenchyma, 45 demonstrated a relatively decreased ADC, while eight had normal ( +/- 10%) and six had increased ADC. In four cases, signal abnormalities on EPDI were not seen or exceeded that seen with conventional MR imaging. In the remaining cases, signal abnormalities were obvious on EPDI and more subtle on conventional MR imaging. Follow-up studies demonstrated resolution of abnormal EPDI signal with persistent abnormalities on conventional imaging in some cases, while others revealed an increase in size or number of EPDI signal abnormalities, suggesting ongoing acute ischemic/infarctive changes. EPDI is a rapid, sensitive technique for detecting watershed ischemic/infarction changes in pediatric patients with hypoperfusion episodes, at times before such changes are apparent on conventional MR images and/or are clinically apparent.

Hyperperfusion syndrome with hemorrhage after angioplasty for middle cerebral artery stenosis

Hyperperfusion syndrome is a well-documented complication of carotid endarterectomy, as well as internal carotid artery angioplasty and stent placement. We report a similar complication after distal intracranial (middle cerebral artery [MCA] M2 segment) angioplasty. To our knowledge, this is the first report of hyperperfusion syndrome after intracranial angioplasty of a distal MCA branch.

Characterization of cultured human prostatic epithelial cells by cluster designation antigen expression

Cultured prostatic epithelial cells have been extensively studied as a model of prostate biology. What is the lineage relationship of the cultured cells to the epithelial cell types in tissue? How different are cultured cells derived from tumor tissue to those derived from benign tissue? Expression of cluster designation (CD) cell surface molecules has been shown to be useful in characterizing cells according to lineage. A CD profile was therefore generated for cultured human prostatic epithelial cells and compared with those previously established for basal and luminal epithelial cells in the prostate. Presence of CD44, CD49b, CD49f, and CD104 and absence of CD57 suggests that cultured cells were derived from basal cells of prostatic tissues. However, expression of certain CD antigens characteristic of luminal epithelial cells was also observed in subpopulations of cultured cells. The pattern of CD antigens in cultured cells reflects a phenotype similar to that of transit-amplifying cells that have been described in the prostate. Several CD antigens were found expressed by both cultured prostatic epithelial and stromal cells, and are probably associated with cell proliferation. The CD profiles of cultured epithelial cell strains derived from normal compared with malignant tissues were notably similar to each other and to that of the prostate cancer cell line PC-3. We conclude that cells in culture retain expression of certain lineage-characteristic CD antigens. Furthermore, CD antigens can define subpopulations of cells with differential gene expression.

Gastric choriocarcinoma shows characteristics of adenocarcinoma and gestational choriocarcinoma: a comparative genomic hybridization and fluorescence in situ hybridization study

The authors report two cases of the rare primary gastric choriocarcinoma. These tumors showed an overwhelming predominance of cytotrophoblast- and syncytiotrophoblast-like tumor cells that were positive for beta-human chorionic gonadotrophin, with small foci of glandular differentiation. Beta-human chorionic gonadotrophin was also detected serologically in one patient. Comparative genomic hybridization study was performed on one specimen. Copy number gains of chromosomes 12, 17, 20, 22, and X, together with losses on 18q, were the major findings. Except for the gain of chromosome 12, which is known to be uncommon in primary gastric adenocarcinoma but frequently associated with choriocarcinoma, the remaining genomic imbalances were among the most common comparative genomic hybridization findings reported in primary gastric adenocarcinoma. Fluorescence in situ hybridization on paraffin sections of both specimens confirmed the presence of polysomy 17 and trisomy 12. These results suggest that primary gastric choriocarcinoma genetically possesses characteristics of both adenocarcinoma and gestational choriocarcinoma. The authors believe this is the first interphase cytogenetics study on this rare tumor, and that the results support the theory that gastric choriocarcinoma arises from alternate differentiation pathways of adenocarcinoma.

Beyond Eliashberg superconductivity in MgB2: anharmonicity, two-phonon scattering, and multiple gaps

Density-functional calculations of the phonon spectrum and electron-phonon coupling in MgB (2) are presented. The E(2g) phonons, which involve in-plane B displacements, couple strongly to the p(x,y) electronic bands. The isotropic electron-phonon coupling constant is calculated to be about 0.8. Allowing for different order parameters in different bands, the superconducting lambda in the clean limit is calculated to be significantly larger. The E(2g) phonons are strongly anharmonic, and the nonlinear contribution to the coupling between the E(2g) modes and the p(x,y) bands is significant.

Resolution, detection, and characterization of redox conformers of human HSF1

We describe here an experimental protocol for the resolution, detection, and quantitation of the reduced and oxidized conformers of human heat shock factor 1 (hHSF1) and report on the effects in vitro and in vivo of redox-active agents on the redox status, structure, and function of hHSF1. We showed that diamide, a reagent that promotes disulfide bond formation, caused a loss of immunorecognition of the monomeric hHSF1 protein in a standard Western blot detection procedure. Modification of the Western blot procedure to include dithiothreitol in the equilibration and transfer buffers after gel electrophoresis allowed for the detection of a compact, intramolecularly disulfide cross-linked oxidized hHSF1 (ox-hHSF1) in the diamide-treated sample. The effect of diamide was blocked by pretreatment with N-ethylmaleimide and was reversed by dithiothreitol added to the sample prior to gel electrophoresis. Incubation with nitrosoglutathione at 42 degrees C also promoted the conversion of HSF1 to ox-HSF1; at 25 degrees C, however, nitrosoglutathione was by itself without effect but blocked the formation of ox-hHSF1 in the presence of diamide. The disulfide cross-linked ox-hHSF1 was monomeric and resistant to the in vitro heat-induced trimerization and activation. The possibility that ox-HSF1 may occur in oxidatively stressed cells was evaluated. Treatment of HeLa cells with 2 mm l-buthionine sulfoximine promoted the formation of ox-HSF1 and blocked the heat-induced activation of HSF DNA binding activity. Our result suggests that hHSF1 may have integrated redox chemistry of cysteine sulfhydryl into its functional responses.

Economic consequences of diagnostic imaging for vocal cord paralysis

RATIONALE AND OBJECTIVES

The purpose of this retrospective study was to estimate the economic consequences of evaluating suspected vocal cord paralysis with magnetic resonance (MR) imaging and computed tomography (CT).

MATERIALS AND METHODS

Reports from MR imaging (n = 30) or CT (n = 19) studies of the neck in 49 patients were retrospectively reviewed for causes of vocal cord paralysis. The patients were divided into high-suspicion (n = 20) and low-suspicion (n = 29) groups, based on the presence or absence of a clinically detectable abnormality other than vocal cord immobility. Clinic and inpatient charts were examined to determine the work-up in all cases. The Medicare Resource-based Relative Value Scale was used to estimate the costs of most procedures.

RESULTS

The high-clinical-suspicion group included nine true-positive, four false-positive, seven true-negative, and no false-negative cases. Further work-up was performed in seven true-positive, three false-positive, and one true-negative cases. The total cost of immediate diagnostic work-up in these 20 patients, including MR imaging and/or CT, was $20,737 ($2,304 per true-positive case). The low-suspicion group included two true-positive, nine false-positive, 18 true-negative, and no false-negative cases. Further work-up was performed in both true-positive, four false-positive, and two true-negative cases. The total cost of immediate diagnostic work-up in these 29 patients was $21,698, (mean, $748; $10,849 per true-positive case).

CONCLUSION

The average cost of finding space-occupying lesions in patients with vocal cord paralysis is more than 4.5 times higher in patients without suspicious antecedent clinical findings than in those with such a history. The benefits of obtaining negative findings and of detecting a small number of space-occupying lesions should be weighed against the costs of such examinations and of additional work-up for false-positive findings.

Pervanadate induces the hyperphosphorylation but not the activation of human heat shock factor 1

In this study, we evaluated the effects of pervanadate, a tyrosine phosphatase inhibitor, on the regulation and function of heat-shock factor 1 (HSF1) in HeLa cells. We showed that 50-100 microM pervanadate induced the hyperphosphorylation of the latent HSF1, as demonstrated by a retarded mobility of the HSF1 protein in SDS-polyacrylamide gel electrophoresis and as supported by the reversal of this mobility shift upon treatment of the cell extract with acid phosphatase. Pervanadate by itself had no effect on the monomeric stoichiometry and DNA-binding activity of HSF1. Upon heat shock, the pervanadate-induced hyperphosphorylated HSF1 formed DNA-binding trimers and translocated into the nuclear compartment. At high concentration (approximately 500 microM), pervanadate also induced the tyrosine phosphorylation of many cellular proteins and blunted the heat-induced transcription of hsp 70. N-acetyl cysteine inhibited these effects of pervanadate, suggesting a redox-based mechanism for its activity. Analysis of the activation of mitogen-activated protein kinases (MAPKs) using antibodies specific for the phospho-form (activated) of the kinases in Western blot showed that pervanadate activated extracellular signal-regulated kinase (ERK1/2), c-Jun-N-terminal kinase 1/2 (JNK1/2), and p-38 kinase. Pharmacological inhibitors of the ERK1/2 kinase pathway or the p38 kinase had little or no effect on the pervanadate-induced hyperphosphorylation of HSF1. Our results show that hyperphosphorylation of hHSF1 can occur prior to and independent of other events involved in the activation of hHSF1. The possibility that activation of the MAPK signaling cascade, notably JNK, may contribute to the hyperphosphorylation of human HSF1 (hHSF1) is discussed.

Changes in cell surface molecules associated with in vitro culture of prostatic stromal cells

BACKGROUND

Prostate stromal cells can be readily cultured in vitro. Are these proliferating cells representative of stromal cells in situ? Since the expression of cell surface molecules, like the cluster of differentiation (CD) antigens, can be affected by changes in physiological conditions cultured stromal cells may differ from uncultured stromal cells in their complement of CD molecules.

METHODS

Prostate stromal cells were prepared from tissue specimens and cultured. Flow cytometry was used to analyze the expression of 107 CD molecules in the resultant cells. Expression of the CD molecules by prostate cells in situ was done by immunohistochemistry.

RESULTS

The expression of a number of cell surface molecules such as CD10, CD13, CD26, and CD44 is elevated in prostatic stromal cells cultured in vitro. These are markers of epithelial cells in tissue. Other molecules expressed by the cultured stromal cells include CD29, CD49a, CD49b, CD49d, CD49f, CD51/61, CD54, CD55, CD56, CD58, CD59, CD61, CD71, CD79b, CD81, CD82, CD90, CD95, CD107a, CD130, and CD147. Among these are stromal, epithelial, and nonstromal/nonepithelial markers as defined by tissue immunohistochemistry.

CONCLUSION

Cultured stromal cells express a number of CD molecules normally found in other cell types of the prostate. Cells can express different CD molecules under different conditions.

Activation of heat shock factor 1 by hyperosmotic or hypo-osmotic stress is drastically attenuated in normal human fibroblasts during senescence

We have previously reported that osmotic stress prominently induces the DNA binding activity of the heat shock transcription factor 1 (HSF1). In the present study, we examined the effects of medium osmolarity on both the activation of HSF1 and the programmed cell death in normal human fibroblasts during cellular senescence. The activation of HSF1 occurred rapidly in presenescent (early passage) IMR-90 cells when exposed to either hypo-osmotic or hyperosmotic stress. In contrast, the activation of HSF1 was significantly attenuated in senescent cells. Western blot analysis indicated that equal amounts of HSF1 were present as monomers in the cytoplasm of both presenescent and senescent cells in normal growth medium. Under either hypo-osmotic or hyperosmotic stress, trimerization and nuclear localization of HSF1 occurred in presenescent cells but not in senescent cells. More than 80% of HSF1 in senescent cells remained as monomers in the cytoplasm under osmotic stress, suggesting a defect in the signal transduction pathways that lead to HSF1 trimerization or a dysfunction in the HSF1 protein itself. Possible involvement of mitogen-activated protein kinase (MAPK) signal transduction pathways in the activation HSF1 was investigated by monitoring the activation of the three MAPKs, ERK1/2, JNK1/2, and p38, in cells exposed to hypo-osmotic or hyperosmotic stress. All three MAPKs were activated by hyperosmotic stress but not hypo-osmotic stress, suggesting that the MAPK signal transduction pathways may not be directly linked to the osmotic stress-induced activation of HSF1. In contrast to the rapid heat shock transcription factor (HSF) activation, apoptosis occurred only after long-term exposure to hypo-osmotic or hyperosmotic stress. Despite the prominent induction of HSF1 activation, the presenescent cells were more sensitive than the senescent cells to the osmotic stress-induced apoptosis.

Differential expression of cell surface molecules in prostate cancer cells

The expression of 119 cell surface molecules was catalogued for three prostate cancer cell lines, LNCaP, PC3, and DU145, all of which were established from metastases. Many of these molecules are common to all three cell lines, whereas some are differentially expressed. More prostate basal epithelial cell-specific than luminal epithelial cell-specific molecules are detected, especially in DU145 and PC3 cells. The cancer cells also express molecules that are not normally associated with prostate epithelial cells. As a population, expression of these molecules appears to be heterogeneous. This heterogeneity may be an inherent property of the population.

Long-term outcomes after carotid stent placement treatment of carotid artery dissection

OBJECTIVE

To assess the long-term outcomes after stent placement for the treatment of carotid artery dissections.

METHODS

Between 1992 and 1998, seven patients underwent stenting procedures for treatment of extracranial carotid artery dissections resulting from various causes, including trauma (n = 2), iatrogenesis (n = 2), spontaneous development (n = 2), and fibromuscular dysplasia (n = 1). Stenting procedures were performed for large, nonhealing, dissection-induced pseudoaneurysms (four cases) or severe preocclusive stenosis (three cases). A total of 11 stents were placed (Palmaz stents, n = 8; Wallstents, n = 3). Radiological follow-up examinations were performed after a mean period of 17.7 months (range, 1-67 mo), using conventional or computed tomographic angiography. Clinical follow-up data were obtained after a mean period of 42.9 months (range, 13-72 mo).

RESULTS

All stent placements resulted in complete resolution of dissection-induced stenosis. For two of the four patients with aneurysms, the lesions occluded spontaneously at the time of the procedure. The third patient required coil embolization of the pseudoaneurysm. One patient exhibited progressive shrinkage of the aneurysm in serial follow-up examinations, with healing after 18 months. No clinical complications were associated with the procedures. One patient exhibited progression to asymptomatic occlusion 3 months after stenting. The remaining six patients exhibited no significant changes in luminal diameters. All patients remained in clinically stable condition, with no ischemic symptoms, during more than 3.5 years (mean period) of follow-up monitoring.

CONCLUSION

This experience suggests that stents placed for treatment of extracranial carotid artery dissections remain patent and patients remain free of symptoms on a long-term basis. Additional studies will be required to determine the optimal types of stents and intervals for follow-up monitoring using imaging.

Traumatic brain injury: diffusion-weighted MR imaging findings

BACKGROUND AND PURPOSE

Diffuse axonal injury (DAI) accounts for a significant portion of primary intra-axial lesions in cases of traumatic brain injury. The goal of this study was to use diffusion-weighted MR imaging to characterize DAI in the setting of acute and subacute traumatic brain injury.

METHODS

Nine patients ranging in age from 26 to 78 years were examined with conventional MR imaging (including fast spin-echo T2-weighted, fluid-attenuated inversion-recovery, and gradient-echo sequences) as well as echo-planar diffusion-weighted MR imaging 1 to 18 days after traumatic injury. Lesions were characterized as DAI on the basis of their location and their appearance on conventional MR images. Trace apparent diffusion coefficient (ADC) maps were computed off-line with the diffusion-weighted and base-line images. Areas of increased signal were identified on the diffusion-weighted images, and regions of interests were used to obtain trace ADC values.

RESULTS

In the nine patients studied, isotropic diffusion-weighted images showed areas of increased signal with correspondingly decreased ADC. In one case, decreased ADC was seen 18 days after the initial event.

CONCLUSION

Decreased ADC can be demonstrated in patients with DAI in the acute setting and may persist into the subacute period, beyond that described for cytotoxic edema in ischemia.

Analysis and sorting of prostate cancer cell types by flow cytometry

BACKGROUND

Prostate tumor heterogeneity as manifested by differential expression of markers can be attributed to multiple types of cancer cells populating a tumor. Does the composition differ between primary tumor and metastasis? How can one isolate the different cancer cell types to study? What is the relationship among cancer cell types?

METHODS

Flow cytometry keying on the prostate epithelial cell surface markers CD57 and CD44 was applied to analyze and sort single cells prepared from tumor tissue samples by collagenase digestion. In normal tissue, CD57 is found on luminal cells and CD44 on basal cells.

RESULTS

CD57(+) and CD44(+) cells were sorted from various prostate tumor tissue specimens. The CD57(+) cancer cell type was found to predominate in primary tumors, while the CD44(+) cancer cell type was found to predominate in two visceral metastases. All tumors could be characterized by a ratio of CD57(+) and CD44(+) cancer cells.

CONCLUSIONS

Two types of prostate cancer cells, CD57(+) and CD44(+), were identified. The finding that most primary tumors contain a predominantly CD57(+) cancer cell population agrees with the argument that cancer cells arise from the transformation of CD57(+) luminal cells. However, CD44(+) cancer cells are also present in some primary tumors; and in some metastases, they, and not CD57(+) cells, constitute a predominant population.

Percutaneous transfemoral embolization of an indirect carotid-cavernous fistula with cortical venous access to the cavernous sinus. Case report

The authors present the case of a 61-year-old man with an indirect carotid-cavernous fistula (CCF). Many now advocate a primary transvenous approach to deal with such lesions, with packing and thrombosis of the cavernous sinus leading to fistula obliteration. Transvenous access to the cavernous sinus via the inferior petrosal sinus is the usual route of access; both surgical and transfemoral superior ophthalmic vein approaches are also well described. In the case presented, the anatomy of the CCF was unfavorable for these approaches and its dominant venous egress was via a single enlarged arterialized cortical vein. The cavernous sinus was accessed with a transfemoral retrograde approach to the cortical draining vein. Successful CCF embolization was documented radiographically and clinically. To the authors' knowledge, this procedure has not been previously described in the English literature.

Hevin, an antiadhesive extracellular matrix protein, is down-regulated in metastatic prostate adenocarcinoma

Hevin, a gene closely related to the extracellular matrix protein SPARC, is an acidic cysteine-rich glycoprotein shown to be important for the adhesion and trafficking of cells through the endothelium. Through the use of differential display and differential EST analysis, we identified Hevin as a gene whose transcription is down-regulated in transformed prostate epithelial cell lines and metastatic prostate adenocarcinoma. These results were confirmed by comparing expression levels between normal and neoplastic human prostate tissues using Northern analysis. In situ hybridization with an 35S-labeled antisense riboprobe demonstrated the loss of Hevin expression in metastatic prostate carcinoma. The expression pattern of Hevin in transformed and metastatic epithelium may provide further insights into the complex cell adhesion events involved in the metastatic progression of prostate carcinoma.

An expressed-sequence-tag database of the human prostate: sequence analysis of 1168 cDNA clones

The human prostate is a complex glandular organ with functional development under hormonal regulation. Diseases of the prostate result in significant morbidity and mortality in the form of benign prostatic hypertrophy and prostate adenocarcinoma. The characterization of the molecular framework of the human prostate at the level of expressed genes will facilitate the understanding of normal and pathological prostate biology. The purposes of this study were to acquire an initial assessment of the qualitative and quantitative diversity of gene expression in the normal human prostate and to determine the extent that genes with prostate-restricted expression can be assessed using an expressed sequence tag approach. We have constructed a directional cDNA library from normal adult human prostate tissue and partially sequenced the 5' end of 1168 randomly selected cDNA clones, resulting in more than 400 kb of DNA sequence. Homology searches of the sequenced cDNAs against the GenBank and dbEST databases revealed that 43% of the sequences are identical to human genes whose functions are known, 5% are similar but not identical to known genes in humans or lower organisms, 5% match the mitochondrial genome, 9% are composed of interspersed DNA repeats, 30% are homologous to sequences in the dbEST database without a described function, and 6% are novel sequences. A total of 780 distinct species were identified. In addition to the 74 novel transcripts, 4 genes, prostate-specific antigen (PSA), prostate secretory protein (PSP), prostate acid phosphatase (PAP), and human glandular kallekrein 2 (HK2), have no homologous sequences in the databases that originate from sources other than prostate and thus may represent genes with prostate-restricted expression. Sequences matching PSA, PSP, and PAP each accounted for > 1% of the total ESTs and represent highly abundant transcripts, correlating with the abundance of these proteins in the prostate gland. No novel transcripts were represented by more than one EST and thus are expressed at levels much lower than the known prostate-specific genes.

The heat-shock transcription factor HSF1 is rapidly activated by either hyper- or hypo-osmotic stress in mammalian cells

Osmoregulation, the cellular response to environmental changes of osmolarity and ionic strength, is important for the survival of living organisms. We have demonstrated previously that an exposure of mammalian cells to hypo-osmotic stress, either in growth medium (30% growth medium and 70% water) or in binary solution containing sorbitol and water, prominently induced the DNA-binding activity of the heat-shock transcription factor (HSF1) [Huang, Caruccio, Liu and Chen (1995) Biochem. J. 307, 347-352]. Since hyperosmotic and hypo-osmotic stress usually elicit opposite biological responses, we wondered what would be the effect of hyperosmotic stress on HSF activation. In this study we have examined the HSF DNA-binding activity in HeLa cells maintained in the sorbitol/water binary solution over a wide concentration range (0.1-0.9 M) and in Dulbecco's medium supplemented with sorbitol or NaCl. We found that HSF-binding activity could be induced prominently under both hypo-osmotic (0.1-0.25 M) and hyperosmotic conditions (0.50-0.90 M). In both cases, HSF activation was observed within 5 min after changing the osmotic pressure. The activation was accompanied by both HSF trimerization and nuclear translocation, and appeared to be independent of protein synthesis. The effects of hypo- or hyper-osmotic stress on HSF activation could be reversed once the cells were returned to iso-osmotic conditions (0.30M) with a half-life (t12) of 25 min or less. This rapid turnover of the osmotic-stress-induced HSF-binding activity was inhibited by cycloheximide, a potent inhibitor of protein synthesis. Unlike heat shock, activation of HSF by either hypo- or hyper-osmotic stress did not lead to an accumulation of heat-shock protein 70 (HSP70) mRNA in HeLa cells. We propose that HSF activation during osmotic stress may serve physiological functions independent of the synthesis of heat-shock proteins.

Cell-cell interaction in prostate gene regulation and cytodifferentiation

To examine the role of intercellular interaction on cell differentiation and gene expression in human prostate, we separated the two major epithelial cell populations and studied them in isolation and in combination with stromal cells. The epithelial cells were separated by flow cytometry using antibodies against differentially expressed cell-surface markers CD44 and CD57. Basal epithelial cells express CD44, and luminal epithelial cells express CD57. The CD57+ luminal cells are the terminally differentiated secretory cells of the gland that synthesize prostate-specific antigen (PSA). Expression of PSA is regulated by androgen, and PSA mRNA is one of the abundant messages in these cells. We show that PSA expression by the CD57+ cells is abolished after prostate tissue is dispersed by collagenase into single cells. Expression is restored when CD57+ cells are reconstituted with stromal cells. The CD44+ basal cells possess characteristics of stem cells and are the candidate progenitors of luminal cells. Differentiation, as reflected by PSA production, can be detected when CD44+ cells are cocultured with stromal cells. Our studies show that cell-cell interaction plays an important role in prostatic cytodifferentiation and the maintenance of the differentiated state.

Relationship between the size and margin status of ductal carcinoma in situ of the breast and residual disease

BACKGROUND

For women with ductal carcinoma in situ (DCIS) of the breast who have been treated with breastconserving surgery, the usefulness of size and surgical margin status (i.e., presence or absence of disease at the point of excision) as prognostic factors for predicting residual disease has not been well established. This study was conducted to determine more clearly the relationship between size and margin status of mammary DCIS to residual disease.

METHODS

The pathology records of 232 consecutive patients with mammary DCIS who had been initially treated with lumpectomy at the University Hospitals of Cleveland were retrospectively reviewed. The size of the DCIS and the surgical margins of lumpectomy were analyzed. Residual disease was defined as the persistence of DCIS in the re-excision and/or mastectomy specimens.

RESULTS

Residual disease was found in 15 of 101 patients with DCIS of less than 1.0 cm in longest dimension, in 27 of 96 patients with DCIS of 1.0-2.4 cm in size, and in 24 of 35 patients with DCIS of greater than or equal to 2.5 cm in size (P<.001). Residual disease was found in 30 of 77 patients with DCIS and positive margins, in 11 of 59 patients with DCIS and close margins (< or =1mm), and in 10 of 73 patients with DCIS and negative margins (>1 mm) (P =.001). In multivariate analysis, the occurrence of residual disease was associated with large tumor size (i.e., > or =2.5 cm) (odds ratio [OR] = 7.7; 95% confidence interval [CI] = 3.13-20.00; two-sided P = .0001) and with positive margin status (OR = 2.2; 95% CI = 1.02-4.55; two-sided P = .04).

CONCLUSIONS

The size and margin status of DCIS each were found to be independent predictors of residual disease.

[Analysis of sedative effect of chloral hydrate and diazepam on children during CT examination]

Before CT examination, make those non-cooperation children take chloral hydrate or diazepam according to their ages can go beyond the limit to reduce the repeation and dose of taking medicine and shorten the waiting time. The author collected 204 samples and divided them into three groups of baby, infant and preschool children. Among them, there were 94 samples of taking orally chloral hydrate and 110 ones having intravenous injection with diazepam according to doctor's order. The author also compared the effect of sedation and the chi 2 test showed that chloral hydrate and diazepam had similar effect on babies (P > 0.05), while the sedative effect of diazepam on infants and preschool children was superior to that of chloral hydrate on them (P < 0.05, P < 0.01).

The results of intraoperative consultations in 181 ductal carcinomas in situ of the breast

BACKGROUND

The utility of frozen section (FS) examination in the intraoperative management of breast lesions is well established. The accuracy of FS in the diagnosis of borderline noninvasive or preinvasive breast lesions is uncertain.

METHODS

The authors retrospectively reviewed the results of intraoperative consultations/frozen section examinations of 181 ductal carcinomas in situ (DCIS) of the breast. Various clinical and pathologic factors were analyzed and correlated with FS diagnosis.

RESULTS

FS examination was performed on 153 cases (85%) and only macroscopic examination on 28 cases (15%). FS diagnoses were as follows: DCIS in 76 cases (50%), atypical ductal hyperplasia/suspicious for DCIS in 8 cases (5%), benign in 55 cases (36%), deferred in 13 cases (8%), and invasive carcinoma in 1 case. FS accuracy, false-negative rate, and false-positive rate were 55%, 36%, and 0.6%, respectively. Sampling error was the main reason for the low detection rate, and technical inadequacy was a major factor contributing to interpretive problems. In multivariate regression analysis, FS accuracy was significantly associated with the clinical presentation of a palpable mass (odds ratio [OR] = 4.16, 95% confidence interval [CI]: 2.04-8.45), the macroscopic finding of a mass (OR = 3.03, 95% CI: 1.45-6.67), and necrosis (OR = 3.13, 95% CI: 1.4-6.67).

CONCLUSIONS

The authors concluded that the accuracy of FS diagnosis of DCIS was low, mainly due to sampling error. In general, FS examination should not be performed when no lesion/mass is identified by macroscopic examination.

Two-photon holographic recording in aluminosilicate glass containing silver particles

Recording of holographic gratings by 532-nm laser pulses in photochromic bulk aluminosilicate glass containing silver particles is demonstrated. A diffraction efficiency of 1.5% is achieved for readout at the same wavelength. The speed of grating formation as a function of pulse energy suggests that two-photon excitation is responsible for the recording. The light causes bleaching of an absorption peak near 417nm, which corresponds to the excitation of surface plasmons on the silver, and broad darkening throughout the visible to the near infrared. A likely mechanism for the photochromic effect is discussed.

Improved reverse transcriptase-polymerase chain reaction protocol with exogenous internal competitive control for prostate-specific antigen mRNA in blood and bone marrow

The possibility of improving diagnosis of micrometastases from prostate cancer by further enhancing the detection of prostate-specific antigen-producing cells in circulation is being evaluated. We have developed a reverse transcriptase-PCR protocol with the desirable characteristics of low limit of detection, high specificity, reproducibility of response, and ease of performance. Among the procedural alterations that have contributed to these improvements are longer PCR primers, a two-step amplification cycle, and hot-start PCR. We have lowered the limit of detection to one LNCaP prostate-cancer cell in 10(8) peripheral blood mononuclear cells, and samples of blood and bone marrow from healthy donors have yielded no false positives. Because PCR procedures frequently exhibit tube-to-tube variability, we have incorporated a set of internal and external controls into the protocol-a significant advance in assuring assay reliability.

Identification of differentially expressed prostate genes: increased expression of transcription factor ETS-2 in prostate cancer

BACKGROUND

Little is known about the genetic events in the malignant transformation of prostatic cells. This is due in large measure to the cellular heterogeneity of the prostate.

METHODS

An amplification method was devised to synthesize cDNA from small samples of cancer and benign tissues of the same resected glands. Differential gene expression of candidate informative markers between cancer and benign was screened by the polymerase chain reaction with gene-specific oligonucleotide primers.

RESULTS

The expression of a transcription factor, ETS-2, was shown to be elevated in some cancer specimens. Elevated expression was also noted for neuron-specific enolase (NSE) and another transcription factor, SEF2.

CONCLUSIONS

Our method can be used to identify quickly genes that are differentially expressed between benign and cancerous prostate cells. Transcription factors, such as ETS-2, may play a significant role in cancer progression.

Observation and thermal fixing of holographic gratings in lead barium niobate crystal

We report what we believe to be the first observation of photorefractive gratings in lead barium niobate (Pb(1-x)Ba (x)Nb(2)O>( 6) ; PBN). A diffraction efficiency of 9% and a beam-coupling coefficient of 9 cm(-1) are obtained. After thermal fixing a grating of 0.5% is revealed at room temperature. We can improve this diffraction efficiency by optimizing fixing temperature, timing, and material parameters.

The human NTT gene: identification of a novel 17-kb noncoding nuclear RNA expressed in activated CD4+ T cells

We describe the cloning and characterization of the NTT gene (noncoding transcript in T cells), identified by differential display RT-PCR based on the differential presence of its transcript in a subset of activated, human CD4+ T-cell clones. The full-length cDNA and genomic sequences were cloned and found to produce a 17-kb transcript that is polyadenylated, but is not spliced. Consistent with the transcript's nuclear predominance, NTT has no open reading frame larger than 270 bp. It is transcribed in a select subset of CD4+ T-cell clones propagated in vitro. Its transcription can also be induced in freshly isolated T cells by in vitro activation with PHA or with PMA and ionomycin. In vivo, NTT transcripts are found only in activated, but not resting, T cells. Transcripts were absent in a variety of lymphoid cell lines and transformed lines from other tissues. NTT is a new member of the small group of genes including XIST (X-specific transcript), H19, and IPW (imprinted gene in the Prader-Willi syndrome region), which are transcribed but not translated, and may have a role in the regulation of neighboring genes. XIST, H19, and IPW exhibit monoallelic expression, but both NTT alleles are expressed in CD4+ T-cell clones. Southern blot and fluorescence in situ hybridization analyses show that NTT is a single-copy gene residing in chromosome 6q23-q24, near the interferon-gamma receptor gene (IFN-gamma R). Their proximity and shared expression pattern suggest a possible functional relationship.

Heat shock response, heat shock transcription factor and cell aging

A characteristic feature of aging is a progressive impairment in the ability to adapt to environmental challenges. The purpose of this article is to review the evidence of an attenuated response to heat and physiological stresses in a number of mammalian aging model systems, including the human diploid fibroblasts in culture, whole animals and animal-derived cells and cell cultures, as well as peripheral blood mononuclear cells obtained from human donors. Analyses of the regulation and function of heat shock factor 1 (HSF1), a transcription factor that mediates the response to heat shock, showed that while the relative abundance of both the hsf1 transcript and the HSF1 protein did not change as a function of age, the responsiveness of HSF1 to heat-induced activation, as measured by its trimerization and ability to bind to the heat shock element consensus sequence, was inversely related to the age of the cells used. Given the fundamentally important role of heat shock proteins (HSPs) in many aspects of protein homeostasis and signal transduction it seems likely that the inability, or compromised ability, of aging cells and organisms to activate HSF1 and produce HSPs in response to stress would contribute to the well-known increase in morbidity and mortality of the aged when challenged.

Prostatic cell lineage markers: emergence of BCL2+ cells of human prostate cancer xenograft LuCaP 23 following castration

A model of prostate cancer progression based on the expression pattern of informative genes in the human prostate cancer xenograft LuCaP 23.1 is presented. Apparently, there are at least 2 tumor cell populations of LuCaP 23.1, representing 2 different phenotypes. One is NSE (neuron-specific enolase)-positive and the other NSE-negative. NSE-positive tumors were recovered after hormone-independent growth in castrated mice. These hormone-independent tumors also expressed BCL2, a gene product shown to inhibit apoptosis. With NSE, BCL2 and PSA (prostate-specific antigen) as identifying markers, the model specifies a putative progression sequence of the prostate cancer cell types. We also show a proposed lineage relationship among the 3 principal normal cell types found in the prostatic epithelium.

Attenuated heat shock transcriptional response in aging: molecular mechanism and implication in the biology of aging

A characteristic feature of aging is a progressive impairment in the ability to adapt to environmental challenges. The purpose of this review is to present the experimental evidence of an attenuated heat shock transcriptional response to heat and physiological stresses in a number of aging mammalian model systems. These include the human diploid fibroblasts in culture, whole animals and animal derived cells and cell cultures, as well as peripheral blood mononuclear cells obtained from human donors. The possibility that age-dependent changes in cellular redox status, as exemplified by the increased production of reactive oxygen inter-mediates and accumulation of oxidatively-modified proteins, affects the regulation and function of the heat shock factor 1 (HSF1) and contributes to the attenuated heat shock transcriptional response in aging cells and organisms is discussed. Given the fundamentally important role of HSPs in many aspects of protein homeostasis and signal transduction, it seems likely that the inability, or compromised ability, of aging cells and organisms to produce HSPs in response to stress would contribute to the well known increase in morbidity and mortality of the aged when challenged.