bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil carbon sequestration and density distribution in a Vertosol under different farming practices
Authors: Wang W. J. , Dalal R. C. , Moody P. W.
Published: December 2004

Abstract
Agricultural soils play an important role in the global carbon (C) cycling and can act as a significant C sink if managed properly. The long-term (33 years) effects of no till (NT) v. conventional till (CT), stubble retention (SR) v. stubble burning (SB), and N fertiliser application (NF) v. nil N fertilisation (N0) on soil organic C sequestration, and their seasonal variations during the fallow period, were studied in a winter cereal–summer fallow cropping system under semi-arid subtropical climate in Queensland, Australia. The function of different density fractions of soil organic C in determining total organic C (TOC) dynamics and sequestration was investigated. Significant effect of NT, SR, or NF on soil organic C level was observed only in the top 10 cm soil and when they were practiced together, with the TOC contents being 1.1 to 3.4 t/ha higher under NT + NF + SR than under other treatments. There were significant seasonal fluctuations in TOC contents at different stages of the fallow period, and the lowest levels of TOC and treatment effects were observed in the late fallow period. Density fractionation of soil organic C showed that light fraction C (<1.6 g/cm3) declined rapidly during the fallow period and did not accumulate substantially in soil. TOC dynamics, either as a consequence of seasonal variations or as a long-term response to different farming practices, were predominantly controlled by the changes in the heavy fraction C (>1.6 g/cm3).
Clay mineralogy effects on sodium fluoride pH of non-allophanic tropical soils
Authors: Alves M. E. , Lavorenti A.
Published: December 2004

Soil pH measured in 1 m NaF (pHNaF) can be a useful tool for soil classification and to provide better advice on the chemical management of agricultural soils in the tropics. In this study, we verified the effects of clay mineralogy on pHNaF values of non-allophanic soils of São Paulo State, Brazil. Fourteen subsurface soil samples were characterised for chemical properties, clay content, clay mineralogy, and for pHNaF values, which were measured in the whole soil and in both natural and deferrified (dithionite-treated) clay fractions. Regression and correlation analyses showed that both ammonium-oxalate-extractable Al (Alo) and gibbsite contents have positive relationships with both clay and soil pHNaF values. On the other hand, kaolinite is inversely related to the pHNaF measured in the clay and has nonsignificant effect on soil pHNaF. X-ray diffraction patterns of dithionite-treated clays did not show disruption of kaolinite or gibbsite after the treatment with 1 m NaF, suggesting that the displacement of surface OH groups by F– seems to be the main mechanism associated with the pH increase verified in the NaF solution after its contact with the deferrified clay fraction. The smaller influence of hematite on pHNaF seems to be due to its correlation to Alo. Goethite and ammonium-oxalate-extractable Fe (Feo) exert no effect on pHNaF. Finally, the relationships observed in the present study strongly suggest that pHNaF values <10.3 measured in non-allophanic kaolinitic soils with low levels of non-humified organic matter are essentially due to their smaller Alo and gibbsite contents, which agrees with the direct correlation verified between pHNaF and soil weathering degree.
Effect of soil properties on growth promotion of wheat by Penicillium radicum
Authors: Wakelin S. A. , Warren R. A. , Ryder M. H.
Published: December 2004

Penicillium radicum is a phosphate-solubilising fungus with plant growth promoting (PGP) activity. The widespread agronomic use of P. radicum as an inoculant is dependent on the accurate prediction of conditions where PGP response will occur. Therefore, the effect of soil physicochemical and biotic factors on PGP of wheat by P. radicum was investigated. In the first experiment, PGP was assayed in 10 soils with differing physicochemical properties. Each soil was tested with and without treatment with hydroxyapatite—an insoluble form of calcium phosphate used to increase the level of total inorganic P available for microbial solubilisation. Inoculation of wheat with P. radicum significantly (P < 0.05) increased plant growth in 4 of the 10 soils tested. The magnitude of the PGP response varied with soil type, and ranged from 8.5% (plant height, Avon soil) to 75% (plant weight, Mingenew soil). Most soil properties had little influence on PGP, with only low soil fertility (N and/or P) identified as a strong indicator of PGP by P. radicum. When detected, PGP was strongest in acidic soil conditions, although PGP was observed in neutral and alkaline soils. Virtually no interactions were detected between addition of hydroxyapatite to the soil and P. radicum inoculation. The second experiment tested PGP in 3 soils previously found to be non-responsive to inoculation, before and after sterilisation by γ-irradiation. Soil biological factors affected PGP by P. radicum in 2 of the 3 soils tested. In these soils, removal of biological factor(s) increased (P < 0.05 and P < 0.1) PGP by P. radicum. These experiments have shown that large and significant increases in plant growth promotion can be achieved through seed inoculation with P. radicum. However, both abiotic and biotic soil properties play a critical role in determining the success of inoculation. P. radicum-stimulated PGP occurred in infertile soils, with a stronger effect in acidic soil conditions. Furthermore, soil biological factors can have an important role in regulating PGP by P. radicum.
Response of field-grown cotton (Gossypium hirsutum L.) to phosphorus fertilisation on alkaline soils in eastern Australia
Authors: Dorahy C. G. , Rochester I. J. , Blair G. J.
Published: December 2004

Abstract. Seventeen field experiments were conducted on alkaline soils in eastern Australia between 1997 and 2000 to evaluate irrigated cotton response to phosphorus (P) fertilisation. Only 3 experiments demonstrated significant (P < 0.05) increases in crop P uptake or lint yield with P application. Comparison of several soil P tests revealed that Colwell (bicarbonate) P provided the best correlation with P uptake at early flowering and lint yield. Soil P may limit cotton growth where Colwell-P concentrations are <6 mg/kg. Soil P concentrations at most of the sites were well above this critical limit, so P fertiliser application was not required. Average P uptake at physiological cut-out and P removal in seed cotton was 21 and 15 kg P/ha, respectively. Apparent P fertiliser recovery was variable (0–67%) and may have contributed to the lack of response that was observed in 14 out of the 17 experiments. It is recommended that at least 40 kg P/ha be applied to soils with Colwell-P concentrations <6 mg/kg to increase soil P reserves. Application rates of at least 20 kg P/ha are recommended where Colwell-P falls between 6 and 12 mg/kg to maintain soil P fertility.
Interactions between antecedent climate and wildfire variability across south-eastern Arizona
Authors: Crimmins Michael A. , Comrie Andrew C.
Published: December 2004

Long-term antecedent climate conditions are often overlooked as important drivers of wildfire variability. Fuel moisture levels and fine-fuel productivity are controlled by variability in precipitation and temperature at long timescales (months to years) before wildfire events. This study examines relationships between wildfire statistics (total area burned and total number of fires) aggregated for south-eastern Arizona and antecedent climate conditions relative to 29 fire seasons (April–May–June) between 1973 and 2001. High and low elevation fires were examined separately to determine the influence of climate variability on dominant fuel types (low elevation grasslands with fine fuels v. high elevation forests with heavy fuels). Positive correlations between lagged precipitation and total area burned highlight the importance of climate in regulating fine fuel production for both high and low elevation fires. Surprisingly, no significant negative correlations between precipitation and seasonal wildfire statistics were found at any seasonal lag. Drought conditions were not associated with higher area burned or a greater number of fires. Larger low elevation fires were actually associated with wet antecedent conditions until just before the fire season. Larger high elevation fires were associated with wet conditions during seasons up to 3 years before the fire season.
Gene transduction in skin cells: Preventing cancer in xeroderma pigmentosum mice
Authors: Marchetto Maria Carolina N. , Muotri Alysson R. , Burns Dennis K. , Friedberg Errol C. , Menck Carlos F. M.
Published: December 2004

UV radiation is the most common risk factor for skin cancer. Patients with the autosomal recessive DNA repair disorder xeroderma pigmentosum (XP) suffer high incidence of skin cancer after sunlight exposure. XP-mutant mice are attractive models to study this syndrome, as they, too, develop UV radiation-induced skin tumors, mimicking the human phenotype. Recombinant adenovirus carrying the human
XPA
gene was used for
in vivo
gene therapy in UVB-irradiated skin of such mice. Virus s.c. injection led to the expression of the XPA protein in basal keratinocytes and prevented deleterious effects in the skin, including late development of squamous cell carcinoma. Thus, efficient adenovirus gene delivery to the skin is a promising tool for reconstitution of specific DNA repair defects in XP patients.
Massive horizontal transfer of mitochondrial genes from diverse land plant donors to the basal angiosperm
Amborella
Authors: Bergthorsson Ulfar , Richardson Aaron O. , Young Gregory J. , Goertzen Leslie R. , Palmer Jeffrey D.
Published: December 2004

Several plants are known to have acquired a single mitochondrial gene by horizontal gene transfer (HGT), but whether these or any other plants have acquired many foreign genes is entirely unclear. To address this question, we focused on
Amborella trichopoda
, because it was already known to possess one horizontally acquired gene and because it was found in preliminary analyses to contain several more. We comprehensively sequenced the mitochondrial protein gene set of
Amborella
, sequenced a variable number of mitochondrial genes from 28 other diverse land plants, and conducted phylogenetic analyses of these sequences plus those already available, including the five sequenced mitochondrial genomes of angiosperms. Results indicate that
Amborella
has acquired one or more copies of 20 of its 31 known mitochondrial protein genes from other land plants, for a total of 26 foreign genes, whereas no evidence for HGT was found in the five sequenced genomes. Most of the
Amborella
transfers are from other angiosperms (especially eudicots), whereas others are from nonangiosperms, including six striking cases of transfer from (at least three different) moss donors. Most of the transferred genes are intact, consistent with functionality and/or recency of transfer.
Amborella
mtDNA has sustained proportionately more HGT than any other eukaryotic, or perhaps even prokaryotic, genome yet examined.
Argan (Argania spinosa) oil lowers blood pressure and improves endothelial dysfunction in spontaneously hypertensive rats
Authors: Berrougui Hicham , de Sotomayor Maria Alvarez , Pérez-Guerrero Concepción , Ettaib Abdelkader , Hmamouchi Mohamed , Marhuenda Elisa , Herrera Maria Dolores
Published: December 2004

Traditionally hand-pressed argan oil, obtained from Argania spinosa seeds, is eaten raw in south-west Morocco; its rich composition of tocopherols, MUFA and PUFA make a study of its actions on risk factors for CVD, such as hypertension, interesting. The effects of 7 weeks of treatment with argan oil (10ml/kg) on the blood pressure and endothelial function of spontaneously hypertensive rats (SHR) and normotensive Wistar–Kyoto rats were investigated. Systolic blood pressure and heart rate were measured every week by the tail-cuff method and endothelial function was assessed by carbachol (10−8 to 10−4m)-induced relaxations of aortic rings and small mesenteric arteries pre-contracted with phenylephrine. Argan-oil administration reduced the mean blood pressure of SHR after the fifth week of treatment (P<0·05) and increased (P<0·01) the endothelial responses of arteries from SHR. The NO synthase inhibitor, l-N-ω-nitroarginine (3×10−5m) revealed a greater participation of NO in the relaxant effect after the treatment. When cyclooxygenase (COX) was blocked with indomethacin (10−5m), an involvement of COX products in the endothelium-dependent response was characterized. Enzyme immunoassay of thromboxane B2 showed a significant decrease (P<0·05) in the release of thromboxane A2 in both aorta and small mesenteric artery after argan-oil treatment of SHR. Experiments in the presence of the thromboxane A2–prostaglandin H2 receptor antagonist ICI 192, 605 (10−5m) confirmed this result. Results after incubation with the antioxidants superoxide dismutase and catalase suggested that a decreased oxidative stress might contribute to explain the beneficial effects of argan-oil treatment.
Polybromo protein BAF180 functions in mammalian cardiac chamber maturation
Authors: Wang Zhong , Zhai Weiguo , Richardson James A. , Olson Eric N. , Meneses Juanito J. , Firpo Meri T. , Kang Chulho , Skarnes William C. , Tjian Robert
Published: December 2004

BAF and PBAF are two related mammalian chromatin remodeling complexes essential for gene expression and development. PBAF, but not BAF, is able to potentiate transcriptional activation in vitro mediated by nuclear receptors, such as RXRα, VDR, and PPARγ. Here we show that the ablation of PBAF-specific subunit BAF180 in mouse embryos results in severe hypoplastic ventricle development and trophoblast placental defects, similar to those found in mice lacking RXRα and PPARγ. Embryonic aggregation analyses reveal that in contrast to PPARγ-deficient mice, the heart defects are likely a direct result of BAF180 ablation, rather than an indirect consequence of trophoblast placental defects. We identified potential target genes for BAF180 in heart development, such as S100A13 as well as retinoic acid (RA)-induced targets RARβ2 and CRABPII. Importantly, BAF180 is recruited to the promoter of these target genes and BAF180 deficiency affects the RA response for CRABPII and RARβ2. These studies reveal unique functions of PBAF in cardiac chamber maturation.
CHOP induces death by promoting protein synthesis and oxidation in the stressed endoplasmic reticulum
Authors: Marciniak Stefan J. , Yun Chi Y. , Oyadomari Seiichi , Novoa Isabel , Zhang Yuhong , Jungreis Rivka , Nagata Kazuhiro , Harding Heather P. , Ron David
Published: December 2004

Unfolded and malfolded client proteins impose a stress on the endoplasmic reticulum (ER), which contributes to cell death in pathophysiological conditions. The transcription factor C/EBP homologous protein (CHOP) is activated by ER stress, and CHOP deletion protects against its lethal consequences. We find that CHOP directly activates GADD34, which promotes ER client protein biosynthesis by dephosphorylating phospho-Ser 51 of the α-subunit of translation initiation factor 2 (eIF2α) in stressed cells. Thus, impaired GADD34 expression reduces client protein load and ER stress in CHOP-/- cells exposed to perturbations that impair ER function. CHOP-/- and GADD34 mutant cells accumulate less high molecular weight protein complexes in their stressed ER than wild-type cells. Furthermore, mice lacking GADD34-directed eIF2α dephosphorylation, like CHOP-/- mice, are resistant to renal toxicity of the ER stress-inducing drug tunicamycin. CHOP also activates ERO1α, which encodes an ER oxidase. Consequently, the ER of stressed CHOP-/- cells is relatively hypo-oxidizing. Pharmacological and genetic manipulations that promote a hypo-oxidizing ER reduce abnormal high molecular weight protein complexes in the stressed ER and protect from the lethal consequences of ER stress. CHOP deletion thus protects cells from ER stress by decreasing ER client protein load and changing redox conditions within the organelle.
Class III Homeodomain-Leucine Zipper Gene Family Members Have Overlapping, Antagonistic, and Distinct Roles in Arabidopsis Development
Authors: Prigge Michael J. , Otsuga Denichiro , Alonso José M. , Ecker Joseph R. , Drews Gary N. , Clark Steven E.
Published: December 2004

The Arabidopsis thaliana genome contains five class III homeodomain-leucine zipper genes. We have isolated loss-of-function alleles for each family member for use in genetic analysis. This gene family regulates apical embryo patterning, embryonic shoot meristem formation, organ polarity, vascular development, and meristem function. Genetic analyses revealed a complex pattern of overlapping functions, some of which are not readily inferred by phylogenetic relationships or by gene expression patterns. The PHABULOSA and PHAVOLUTA genes perform overlapping functions with REVOLUTA, whereas the PHABULOSA, PHAVOLUTA, and CORONA/ATHB15 genes perform overlapping functions distinct from REVOLUTA. Furthermore, ATHB8 and CORONA encode functions that are both antagonistic to those of REVOLUTA within certain tissues and overlapping with REVOLUTA in other tissues. Differences in expression patterns explain some of these genetic interactions, whereas other interactions are likely attributable to differences in protein function as indicated by cross-complementation studies.
Activation ofCRABS CLAWin the Nectaries and Carpels of Arabidopsis
Authors: Lee Ji-Young , Baum Stuart F. , Alvarez John , Patel Amita , Chitwood Daniel H. , Bowman John L.
Published: December 2004

CRABS CLAW (CRC), a member of the YABBY gene family, is required for nectary and carpel development. To further understand CRC regulation in Arabidopsis thaliana, we performed phylogenetic footprinting analyses of 5′ upstream regions of CRC orthologs from three Brassicaceae species, including Arabidopsis. Phylogenetic footprinting efficiently identified functionally important regulatory regions (modules), indicating that CRC expression is regulated by a combination of positive and negative regulatory elements in the modules. Within the conserved modules, we identified putative binding sites of LEAFY and MADS box proteins, and functional in vivo analyses revealed their importance for CRC expression. Both expression and genetic studies demonstrate that potential binding sites for MADS box proteins within the conserved regions are functionally significant for the transcriptional regulation of CRC in nectaries. We propose that in wild-type flowers, a combination of floral homeotic gene activities, specifically the B class genes APETALA3 and PISTILLATA and the C class gene AGAMOUS act redundantly with each other and in combination with SEPALLATA genes to activate CRC in the nectaries and carpels. In the absence of B and C class gene activities, other genes such as SHATTERPROOF1/2 can substitute if they are ectopically expressed, as in an A class mutant background (apetala2). These MADS box proteins may provide general floral factors that must work in conjunction with specific factors in the activation of CRC in the nectaries and carpels.
Congenital panfollicular nevus: report of a new entity
Authors: Finn Laura S. , Argenyi Zsolt B.
Published: December 2004

The various forms of non‐melanocytic nevi (hamartomas) are usually encountered in pediatric patients, and nevus sebaceous of Jadassohn is the most common to have undifferentiated pilosebaceous units. We report a unique congenital follicular nevus that fails to meet the criteria of any previously described follicular neoplasm, despite the plethora of alternatives. Clinically considered a syringocystadenoma papilliferum, the excised lesion contained multiple dermal nodules that exhibited nearly all stages of follicular differentiation. The periodicity of the follicular proliferations was akin to normal terminal hair, and a prominent perifollicular sheath surrounded each. This benign lesion of abortive hair follicles was unassociated with any established genodermatous syndrome or other adnexal neoplasm.
Epstein–Barr virus‐ and human herpesvirus 8‐associated primary cutaneous plasmablastic lymphoma in the setting of renal transplantation
Authors: Verma Shannon , Nuovo Gerard J. , Porcu Pierluigi , Baiocchi Robert A. , Crowson A. Neil , Magro Cynthia M.
Published: December 2004

Background:  Plasmablastic lymphoma (PBL) is a recently recognized entity most often reported in the oral cavity, mainly in the setting of underlying human immunodeficiency viral infection whereby a role for Epstein–Barr virus (EBV) and more recently human herpesvirus 8 (HHV8) has been described. Although EBV has been implicated in a variety of lymphoproliferative lesions, until recently HHV8 has only been associated with primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma. We describe a case of PBL occurring in the setting of renal transplantation.

Methods:  We encountered a case of PBL occurring in the setting of renal transplantation. We characterized the tumor by routine immunohistochemistry and evaluated for the presence of immunoglobulin light chain restriction and EBV RNA by in situ hybridization. We assessed for the presence of HHV8 RNA by reverse transcriptase in situ hybridization.

Results:  The tumor showed a histomorphology compatible with a PBL. In addition, there was strong RNA expression in the neoplastic cells for EBER‐1, EBER‐2, and HHV8.

Conclusion:  This case suggests a possible role of both viruses in the pathogenesis of PBL in sites other than the oral cavity and expands the spectrum of post‐transplantation lymphoproliferative disease to include PBL.
Vacuolated cells in neurofibroma: an immunohistochemical study
Authors: Hattori Hideo
Published: December 2004

Background:  Vacuolated cells could be encountered in neurofibroma.

Objectives:  Frequency and immunohistochemical feature of vacuolated cells in neurofibroma.

Methods:  Sixty‐two lesions of neurofibroma including five plexiform neurofibromas were re‐evaluated for the search of vacuolated cells. Immunohistochemical analysis was performed for cases with vacuolated cells.

Results:  In five cases of plexiform neurofibroma and four cases of sporadic neurofibroma with endoneurial component, presence of vacuolated cells in the endoneurial mucoid area was noted. They were immunoreactive both with S‐100 protein and CD34, mostly negative for factor XIIIa and negative for epithelial membrane antigen. Vacuolated cells were found neither in the diffuse portion of plexiform neurofibroma nor in sporadic diffuse neurofibroma.

Conclusion:  Presence of vacuolated cells is a highly characteristic feature of endoneurial portion of neurofibroma. Considering immunoreactivity both with S‐100 protein and CD34 in the majority of vacuolated cells, they could be regarded as to represent endoneurial precursor cells in a certain stage of differentiation to Schwann cells.
Merkel cell carcinoma in situ
Authors: Ferringer Tammie , Rogers Hudson C. , Metcalf John S.
Published: December 2004

Background:  Merkel cell carcinoma (MCC) is a dermal small blue‐cell tumor that occurs in the elderly on the sun damaged head and neck. Epidermal involvement is unusual and MCC limited to the epidermis is very rare.

Case report:  A slightly tender pink hyperkeratotic papule was noted on the dorsal right hand of a 76‐year‐old man with a history of multiple skin cancers. An intraepidermal proliferation of small blue cells distributed in nests and single units at all levels of the epidermis was found within a solar keratosis and adjacent to an area of squamous cell carcinoma in situ. Cytokeratin 20 and neuron specific enolase highlighted these cells and failed to reveal dermal involvement. There was no residue on re‐excision.

Conclusion:  We report the third case of MCC in situ. These lesions have only been reported in association with squamous neoplasms on the extremities.
Indolent course of the cutaneous Hodgkin's disease
Authors: Jurišić Vladimir , Bogunović Marina , Čolovic Nataša , Čolović Milica
Published: December 2004

Abstract:  Skin involvement in Hodgkin's disease (HD) is most often a secondary phenomenon representing a rare, late manifestation of dissemination of the disease heralding a grave prognosis. Primary cutaneous HD is very unusual, being reported in 0.5–3.4% of all patients. Based on the introduction of immunohistochemistry for better detection and classification, we report a case with an ostensibly isolated primary cutaneous HD who developed multiple cutaneous lesions 5 years before enlargement of the lymph node involved during relapse. Pathohistology of skin lesions and the involved lymph node indeed showed the same subtype (mixed cellularity) of HD characterized by the presence of CD15+, CD30+, CD45RO– cell‐surface markers and by the presence of Epstein–Barr virus+ marker‐analyzed immunohistochemistry.
Pleiotrophin expression correlates with melanocytic tumor progression and metastatic potential
Authors: Wu H. , Barusevicius A. , Babb J. , Klein‐Szanto A. , Godwin A. , Elenitsas R. , Gelfand J. M. , Lessin S. , Seykora J. T.
Published: December 2004

Background:  Gene expression profiling of melanoma and nevic tissue has demonstrated that pleiotrophin (PTN) is significantly overexpressed in human melanomas.

Methods:  To further evaluate PTN expression in melanocytic lesions, protein immunohistochemistry was performed on the spectrum of melanocytic lesions.

Results:  Melanocytic nevi were consistently negative (n = 58). In contrast, the great majority of metastatic melanomas were positive (33/34, 97%). The analysis of 34 primary melanomas demonstrated PTN positivity in 20 lesions while 14 lesions were negative. Within the primary melanomas, PTN immunoreactivity was associated with metastasis (p = 0.0004) and decreased melanoma‐related survival (p = 0.0444). Univariate analysis of PTN immunoreactivity predicted an increased risk for metastasis (relative risk 9.1, p = 0.003).

Conclusions:  The results of this study confirm previous gene profiling data showing differential PTN expression between melanocytic nevi and melanomas. In addition, lesional PTN expression is associated with metastatic potential and may be a prognostic factor for melanomas.
Igloo‐like prepuce: a peculiar aspect of smooth‐muscle hamartoma of the genitalia?
Authors: Sbano Paolo , Sbano Elio , Alessandrini Carlo , Criscuolo Mario , Fimiani Michele
Published: December 2004

Abstract:  We report the case of a 16‐year‐old boy with ‘igloo‐like prepuce’ and hypospadia, successfully treated by asymmetrical antero‐posterior postectomy. Histopathological examination consisting of classical microscopy, immuno‐histochemistry and electronmicroscopy of the surgical material provided insights into the etiopathogenesis of this rare disease.
Epstein Barr Virus (EBV)‐Associated Diffuse Large B‐Cell Lymphoma (BCL) with Isolated Skin Involvement Associated with Combined Immunodeficiency and Multiple Opportunistic Infections
Authors: Burkemper N. , Bridges A.
Published: December 2004

A 72‐year‐old man presented with nausea, vomiting, cough, dyspnea, weight loss and an ulcerated nodule on the right calf of four month's duration. CT revealed multiple bilateral pulmonary nodules. Skin biopsy demonstrated an angiodestructive infiltrate with neutrophils, CD4+ T‐lymphocytes, CD20+ large, atypical lymphocytes and histiocytes in the reticular dermis and subcutis. The atypical lymphocytes were positive for EBV by ISH. PCR demonstrated a clonal immunoglobulin gene rearrangement. Lung biopsy showed histoplasmosis without evidence of a lymphoproliferative disorder or EBV infection. Further investigation revealed a low CD8 count, IgM deficiency and candidal esophagitis. Treatment consisted of itraconazole and rituximab. The cutaneous findings in this patient resemble lymphomatoid granulomatosis (LyG), an angiocentric and angiodestructive lymphoproliferative disorder involving extra‐nodal sites. While LyG can involve multiple organs, it primarily affects the lungs. The infiltrate consists of large, atypical EBV‐positive B‐cells admixed with reactive T‐cells. Although our patient's skin pathology resembles LyG, we favor the broader diagnosis of EBV‐associated diffuse large BCL since he had an isolated skin lesion without evidence of lung or other systemic involvement. We will compare the clinical and histologic findings in our patient to cases of LyG from our institution to help classify this entity among other cutaneous lymphoproliferative disorders.
Primary Cutaneous Paraganglioma (PCP) of the Scalp
Authors: Cernosek Sarka , Ram Ramin , Saadat Payam , Vadmal Manju
Published: December 2004

We report the first case of PCP in a 12‐year‐old boy who presented with a growing, bleeding nodule on his scalp. On physical examination a 1.5 × 1.5 × 1.0‐cm firm, red nodule on the right temporal scalp was observed. Histological examination revealed a dermal neoplasm composed of nests/lobules of uniform, polygonal cells separated by thin fibrous trabeculae. The cells had distinct cell borders, round nuclei with evenly dispersed chromatin and abundant fine, eosinophilic cytoplasm. No mitoses or necrosis were noted. The cells showed a strong positive immunoreaction for vimentin, NSE, chromogranin, synaptophysin, keratin AE3; and a negative immunoreaction for HMB45, melan‐A, muscle markers, AE1, CK20 and EMA. S‐100 protein stained sustentacular cells. Ultrastructural examination of the paraffin embedded tissue revealed electron dense neuroendocrine granules. A complete workup and skin examination for possible neoplasms elsewhere in the body was negative. Follow‐up of the patient, 6 months and 18 months post‐excision revealed no recurrence. In conclusion, we report the first case of PCP documented by histological, immunohistochemical and ultrastructural findings. The tumor described likely represents an aberrant migration of neural crest cells in their decent towards the branchial arches. It also highlights the complex interaction of the neural crest and branchial arches during embryogenesis.
Pigmented Olfactory Neuroblastoma, a Mimic of Melanoma
Authors: Han Amy , Gilliam Anita C. , Jacobs Gretta , Eisenberg Rosana
Published: December 2004

A 23 year‐old man presented with a mass in the nasal cavity, initially diagnosed as malignant melanoma. The diagnosis was based on the presence of tumor cells arranged in nests of varying sizes with some cells containing brown pigment and scattered pigmented macrophages. Immunostaining revealed focal positivity for S100 and vimentin and a negative HMB‐45 stain. The patient was referred to our institution for further evaluation. Upon reviewing the case, a fibrillary background within some nests of tumor cells was noted and additional work‐up was initiated. Immunohistochemistry demonstrated positivity for CD56, synaptophysin, and calretinin. Electron microscopy showed dendritic processes containing neurosecretory granules and no melanosomes or premelanosomes in the tumor cells. Given the findings, a diagnosis of pigmented olfactory neuroblastoma was rendered. The differential diagnosis of nasopharyngeal neoplasms includes olfactory neuroblastoma and malignant melanoma. The usual problem is in distinguishing amelanotic melanomas from olfactory neuroblastomas. The difficulty in our case resided in the fact that the olfactory neuroblastoma contained pigment. In either case, close attention to histologic features, use of immunohistochemistry, and in selected cases, electron microscopy, can lead to the correct diagnosis.
Marginal Zone Lymphoma with a Dual Cutaneous and Leukemic Presentation and an Aberrant Myeloid‐Monocytic Phenotype
Authors: Keehn C. , Cualing H.
Published: December 2004

A 69‐year‐old man with heart failure was hospitalized with worsening dyspnea. At the time of admission he also complained of a “rash” of three weeks duration over the left neck. Multiple erythematous plaques were noted. There was no lymphadenopathy or hepatosplenomegaly. The white blood cell count was elevated at 37,700/uL, with 70% composed of atypical monocytoid lymphocytes with abundant pale‐staining cytoplasm. Skin biopsy showed a superficial and deep nodular dermal lymphoid infiltrate. Bone marrow aspirate and biopsy showed nodules of similar cells. Flow cytometry identified a monoclonal B cell population with light chain restriction, with positivity for CD19, CD20, HLA‐DR, CD11c, FMC7, CD71, and the myeloid‐monocytic marker CD13. There was no expression of CD5 or CD10. B cell receptor gene rearrangement was identified. A diagnosis of extranodal marginal zone lymphoma was made. He was treated for congestive heart failure and discharged. The patient has had an indolent course without chemotherapy, with waxing and waning of the skin lesions. This case is unusual, as leukemic involvement is rare in marginal zone lymphoma and is typically only seen in patients with severe widespread disease with an aggressive clinical course. This is also the first reported case with aberrant expression of myeloid‐monocytic markers.
Secondary Syphilis Presenting as Cutaneous T‐Cell Lymphoma in an HIV‐Positive Patient
Authors: Laungani A. , McDonnell J. , Bergfeld W. , Sellheyer K.
Published: December 2004

We present the case of an HIV‐positive 38‐year‐old Caucasian male with a history of fevers, chills, and disseminated nonpruritic erythematous papules that began on his abdomen. An initial skin biopsy revealed a lymphohistiocytic infiltrate at the dermoepidermal junction, exocytosis of atypical lymphocytes, and minimal spongiosis. Immunohistochemistry showed increased CD8‐positive cells but only scattered CD30‐positive cells. PCR analysis demonstrated T‐cell receptor gamma gene rearrangement. RPR, blood and tissue cultures were all negative. The patient was thought to have a cytotoxic cutaneous T‐cell lymphoma. Over time, the lesions progressed to the palms and soles and the patient remained febrile. Repeat biopsy demonstrated a lichenoid interface dermatitis with a superficial and deep perivascular, interstitial, and periadnexal lymphohistiocytic infiltrate and the formation of epithelioid granulomas throughout the dermis. The epidermis showed blurring of the dermoepidermal junction, spongiosis, and exocytosis of lymphocytes and neutrophils. Few spirochetes were demonstrated by Steiner stain. Repeat RPR and FTA‐Abs serologies were positive. The patient was diagnosed with late secondary syphilis and was successfully treated with benzathine penicillin. This case demonstrates that atypical lymphoid infiltrates can simulate mycosis fungoides in an HIV‐positive patient with secondary syphilis and also reiterates that syphilis is a great mimicker of other entities.
NK/T‐Cell Lymphoma Presenting as Subcutaneous Nodules in a Previously Healthy Young Woman: an Unusual Granulomatous Component Found on Biopsy
Authors: Rubin A. , Husain S.
Published: December 2004

A 27‐year‐old previously healthy woman presented with an acute onset of multiple tender subcutaneous nodules and nasal congestion. Biopsy of an arm nodule revealed an atypical, dense, diffuse cellular infiltrate, predominantly involving the deep dermis and the subcutaneous fat lobules. The infiltrate consisted of a spectrum of small, medium to large sized lymphocytes with the large lymphocytes predominating. The lymphoid cells showed irregular nuclear contours, fine chromatin, and indistinct nucleoli. Mitoses were frequent. A significant granulomatous component was present. In foci the infiltrate revealed an angiotropic and angiodestructive pattern. Large areas of tumor cell necrosis were noted. The subcutaneous infiltration was reminiscent of a lobular panniculitis, with areas resembling subcutaneous panniculitis‐like T‐cell lymphoma. Special stains for infectious organisms were negative. The neoplastic cells were CD2+, CD7+, CD3‐, CD5‐, CD8+, CD56+, CD52+, TIA‐1+, perforin+, granzyme‐B+, and LMP‐1‐. The infiltrate was EBV+. Flow cytometry showed 93% of cells to be NK cells. Workup revealed many nodules in the abdominal wall, lungs, and liver as well as sinusitis. The patient failed CHOP and ICE chemotherapy. The nodules resolved after three cycles of L‐aspariginase, vincristine, and dexamethasone. NK/T‐cell lymphoma usually affects middle‐aged and older adults. This case contains an unusual granulomatous component on biopsy.
A Case of Kaposiform Hemangioendothelioma and Kasabach‐Merritt Phenomenon
Authors: Shackelford K. , Tamburro J. , Billings S.D.
Published: December 2004

Kaposiform hemangioendothelioma (KH) is a vascular tumor of intermediate malignancy that occurs in childhood, of which 50% are present at birth. The tumor has a predilection for the trunk, extremities, and retroperitoneum. It is commonly associated with Kasabach‐Merritt phenomenon, a consumptive coagulopathy characterized by profound thrombocytopenia and hypofibrinogenemia. The histologic differential diagnosis of kaposiform hemangioendothelioma includes infantile hemangioma, tufted angioma, Kaposi's sarcoma, and spindle cell hemangioendothelioma. We present a case of a neonate with a soft tissue mass encompassing the proximal two‐thirds of the right thigh. After delivery by Ceasarean section for failure to progress, the patient developed repiratory failure, consumptive coagulopathy and intracranial hemorrhage. The initial clinical differential diagnosis included KH, infantile hemangioma, and infantile fibrosarcoma, all entities which have been associated with Kasabach‐Merritt phenomenon. An biopsy demonstrated a nodular vascular proliferation composed of grouped, spindled endothelial cells forming irregular, slit‐like vascular lumens. There were associated fragmented red blood cells and hemosiderin deposits. The tumor cells were focally positive for D2–40, an antigen specific for lymphatic endothelium and expressed by KH, and were negative for GLUT‐1, an antigen expressed in infantile hemangiomas but not KH. The histologic and immunohistochemical findings confirmed the diagnosis of KH.
Necrolytic Acral Erythema
Authors: Sharp M. , Abdallah M. , Hull C. , Horn T.D.
Published: December 2004

A 46‐year‐old hepatitis C‐positive African American woman presented with a several month history of worsening, well‐marginated, erythematous, dusky plaques on the dorsum of her feet and ankles. After an initial skin biopsy showed spongiotic dermatitis, she was treated with emollients, high potency topical steroids, and keratolytics, all of which were of no benefit. A punch biopsy from the dorsum of her foot showed acanthosis, individual keratinocyte necrosis, confluent upper epidermal necrosis, and a superficial and deep perivascular lymphocytic infiltrate. Given the patient's positive hepatitis C status and clinicopathological correlation, a diagnosis of necrolytic acral erythema was rendered. Empiric therapy with oral zinc sulfate was initiated despite a normal plasma zinc level, and the skin lesions resolved with post‐inflammatory hyperpigmentation. Necrolytic acral erythema, considered one of the necrolytic erythemas, is a cutaneous manifestation of hepatitis C virus infection. A total of nine cases have been reported in the literature, seven from Egypt and two from the United States. All reported patients have been hepatitis C positive. This case represents the third reported patient from the US with necrolytic acral erythema.
The Situational Interview as a Predictor of Academic and Team Performance: A Study of the Mediating Effects of Cognitive Ability and Emotional Intelligence
Authors: Christina Sue‐Chan , Latham Gary P.
Published: December 2004

The criterion‐related and construct validity of the situational interview (SI) was examined. Both the SI and cognitive ability had predictive validity for the academic performance of managers and professionals (n=75) in an executive MBA course. Only the SI predicted teamplaying behavior assessed by peers (r=.32, p<.05). The correlation between the SI and cognitive ability was not significant. Emotional intelligence completely mediated the relationship between the SI and teamplaying behavior.
Cell cycle arrest of human gingival fibroblasts and periodontal ligament cells by Actinobacillus actinomycetemcomitans: involvement of the cytolethal distending toxin
Authors: BELIBASAKIS G. N. , MATTSSON A. , WANG Y. , CHEN C. , JOHANSSON A.
Published: December 2004

The cytolethal distending toxin (Cdt) is produced by several Gram‐negative bacterial species and causes growth arrest and morphological alterations in mammalian cells. Actinobacillus actinomycetemcomitans, which is involved in the pathogenesis of localized aggressive periodontitis, also produces a Cdt that affects periodontal connective tissue cells. The aim of this study was to investigate in which phase of the cell cycle these cells are arrested and enlarged when challenged with A. actinomycetemcomitans, and to evaluate the involvement of its Cdt. Human gingival fibroblasts and periodontal ligament cells were challenged with A. actinomycetemcomitans extract, or with purified Cdt, and cell cycle analysis was performed by propidium iodide staining and flow cytometry. Cells exposed to an A. actinomycetemcomitans wild‐type strain, or to purified Cdt, were arrested in both G1 and G2/M phases, and appeared enlarged compared to the corresponding controls. The cellular enlargement occurred in both G1 and G2/M arrested cells. In contrast, cells exposed to an A. actinomycetemcomitanscdt‐knockout mutant strain showed cell cycle phase distribution and size similar to the controls. In conclusion, A. actinomycetemcomitans causes a combined G1 and G2/M growth arrest and enlargement in periodontal connective tissue cells, which is attributed to its Cdt.
Exacerbation of protracted‐relapsing experimental allergic encephalomyelitis in DA rats by gluten‐free diet
Authors: DI MARCO ROBERTO , MANGANO KATIA , QUATTROCCHI CINZIA , AMATO FILIBERTO , NICOLETTI FERDINANDO , BUSCHARD KARSTEN
Published: December 2004

The observation of neurological dysfunctions resembling multiple sclerosis (MS) seen clinically and/or by MRI in patients with celiac disease has focused attention on the possibility that cryptic gluten sensitivity may be involved in the pathogenesis of MS. Here we study the effects of a gluten‐free diet on the course of protracted‐relapsing EAE in DA rats, serving as a preclinical model of human MS. The data show not only that this nutritional approach failed to ameliorate development of the disease but rather that it exacerbated the course.
Quantum tunneling time
Authors: Davies P. C. W.
Published: December 2004

A simple model of a quantum clock is applied to the old and controversial problem of how long a particle takes to tunnel through a quantum barrier. The model has the advantage of yielding sensible results for energy eigenstates and does not require the use of time-dependent wave packets. Although the treatment does not forbid superluminal tunneling velocities, there is no implication of faster-than-light signaling because only the transit duration is measurable, not the absolute time of transit. A comparison is given with the weak-measurement post-selection calculations of Steinberg.
bdrF
2

of Lyme Disease Spirochetes Is Coexpressed with a Series of Cytoplasmic Proteins and Is Produced Specifically during Early Infection
Authors: Zhang Hongming , Raji Abayami , Theisen Michael , Hansen Paul R. , Marconi Richard T.
Published: December 2004

The Bdr proteins are polymorphic inner membrane proteins produced by most
Borrelia
species. In
Borrelia burgdorferi
B31MI, the18
bdr
genes form three subfamilies,
bdrD
,
bdrE
, and
bdrF
. The production of at least one of the Bdr paralogs, BdrF
2
, is up-regulated in host-adapted spirochetes, suggesting a role for the protein in the mammalian environment. Here, we demonstrate using reverse transcriptase (RT) PCR that BBG29, BBG30, BBG31, and BBG32, which reside upstream of

bdrF
2

, are cotranscribed with

bdrF
2

as a five-gene operon. While the functions of most of these proteins are unknown, BBG32 encodes a putative DNA helicase. Real-time RT-PCR analyses demonstrated higher levels of

bdrF
2

transcript relative to other genes of the operon, suggesting that

bdrF
2

may also be transcribed independently from an internal promoter. Internal promoters were detected using the 5′ rapid amplification of cDNA ends system. The putative promoter associated with

bdrF
2

was found to be highly similar in sequence to the multiple promoters associated with the
ospC
gene. Real-time RT-PCR analyses, performed to assess the expression of these genes in infected mice, revealed that genes of the

bdrF
2

locus are expressed only during early infection, suggesting a role in the establishment of infection. To further characterize the proteins encoded by the

bdrF
2

locus, which have unknown functions, the cellular localizations of these proteins were determined by Triton X-114 extraction and phase partitioning. BBG29 and BBG31 were found to be cytoplasmic. To determine if these proteins elicit an antibody (Ab) response during infection, immunoblot analyses were performed. Abs to these proteins were not detected. Based on the analyses presented here, we offer the hypothesis that BdrF
2
and other proteins encoded by the operon form an inner-membrane-associated protein complex that may interact with DNA and which carries out its functional role during transmission or the early stages of infection.
Intersubunit Complementation of Sugar Signal Transduction in VirA Heterodimers and Posttranslational Regulation of VirA Activity inAgrobacterium tumefaciens
Authors: Wise Arlene A. , Voinov Luba , Binns Andrew N.
Published: December 2004

The VirA/VirG two-component regulatory system ofAgrobacterium tumefaciensregulates expression of the virulence (vir) genes that control the infection process leading to crown gall tumor disease on susceptible plants. VirA, a membrane-bound homodimer, initiatesvirgene induction by communicating the presence of molecular signals found at the site of a plant wound through phosphorylation of VirG. Inducing signals include phenols, monosaccharides, and acidic pH. While sugars are not essential for gene induction, their presence greatly increasesvirgene expression when levels of the essential phenolic signal are low. Reception of the sugar signal depends on a direct interaction between ChvE, a sugar-binding protein, and VirA. Here we show that the sugar signal received in the periplasmic region of one subunit within a VirA heterodimer can enhance the kinase function of the second subunit. However, sugar enhancement ofvirgene expression was vector dependent.virAalleles expressed from pSa-derived vectors inhibited signal transduction by endogenous VirA. Inhibition was conditional, depending on the induction medium and thevirAallele tested. Moreover, constitutive expression ofvirGovercame the inhibitory effect of some but not allvirAalleles, suggesting that there may be more than one inhibitory mechanism.
Methionine Sulfoxide Reduction and Assimilation in
Escherichia coli
: New Role for the Biotin Sulfoxide Reductase BisC
Authors: Ezraty Benjamin , Bos Julia , Barras Frédéric , Aussel Laurent
Published: December 2004

Methionine ranks among the amino acids most sensitive to oxidation, which converts it to a racemic mixture of methionine-
S
-sulfoxide (Met-S-SO) and methionine-
R
-sulfoxide (Met-R-SO). The methionine sulfoxide reductases MsrA and MsrB reduce free and protein-bound MetSO, MsrA being specific for Met-S-SO and MsrB for Met-R-SO. In the present study, we report that an

Escherichia coli metB
1

auxotroph lacking both
msrA
and
msrB
is still able to use either of the two MetSO enantiomers. This indicates that additional methionine sulfoxide reductase activities occur in
E. coli
. BisC, a poorly characterized biotin sulfoxide reductase, was identified as one of these new methionine sulfoxide reductases. BisC was purified and found to exhibit reductase activity with free Met-S-SO but not with free Met-R-SO as a substrate. Moreover, a

metB
1
msrA msrB bisC

strain of
E. coli
was unable to use Met-S-SO for growth, but it retained the ability to use Met-R-SO. Mass spectrometric analyses indicated that BisC is unable to reduce protein-bound Met-S-SO. Hence, this study shows that BisC has an essential role in assimilation of oxidized methionines. Moreover, this work provides the first example of an enzyme that reduces free MetSO while having no activity on peptide-bound MetSO residues.