bluuebunny/crossref_metadata_2025 huggingface dataset:
Some questions on the late-Holocene vegetation of Europe
Authors: Magri Donatella
Published: November 2007

Some examples of postglacial and modern European vegetation are presented as starting points for a discussion on the pattern and processes of the late-Holocene recession of forests. Predictive modern vegetation models are considered; they indicate that deciduous forest may not at present be the dominant vegetation type in northern Europe and in part of central Europe. A comparison of pollen diagrams at a supraregional scale shows that the beginning of deforestation in northern Europe was contemporaneous with expansion of forests in Italy. Some Holocene pollen records, compared with the classical interglacial-cycle models, seem to indicate that, at least in some regions of Europe, the present interglacial might already be in the terminal phase, namely open conifer-dominated woodlands. On the basis of these observations, the hypothesis is suggested that late-Holocene natural openings in the forests, predictable at the end of the interglacials, favouring the diffusion of grasses, produced environments suitable for human settlements, agriculture and pastoral activity.
Holocene evolution of coastal wetlands in wet-tropical northeastern Australia
Authors: Crowley Gabriel M. , Gagan Michael K.
Published: November 2007

Pollen in sediments drilled from the Innisfail coastal plain, northeast Queensland, Australia, was examined to reconstruct the evolution of Holocene wetlands in a wet-tropical environment. In contrast to monsoonal Australia, stable environmental conditions created by year-round rainfall and low tidal range caused abrupt, unidirectional transitions in wetland zonation as marine influence changed. This has enabled a detailed reconstruction of the marine transgression and subsequent progradation. Mangroves colonized in response to marine transgression at c. 7400 BP, as riverine mangroves of low salt tolerance migrated up the Mulgrave River. These were replaced around 7000 BP by extensive Rhizophora-dominated mangroves, coinciding with the development of a Rhizophora-dominated community in Wyvuri embayment. Mangroves reached their greatest extent as sea-level rise slowed towards 6000 BP, with a stillstand indicated by a brief return to terrestrial conditions at one site. High freshwater input depressed salt intrusion in the upper reaches of the Mulgrave estuary and prevented the development of hypersalinity in the upper tidal zone. Drainage conditions then controlled whether mangroves were succeeded by freshwater swamp or swamp-forest.
Palaeoclimatological reconstruction using stable isotope data on continental molluscs from Valle di Castiglione, Roma, Italy
Authors: Bonadonna Francescopaolo , Leone Gabriello
Published: November 2007

Thirty molluscan shells from twenty levels from the first 4.5 m of a long core drilled in the crater lake of Valle di Castiglione, near Rome, have been analysed for their oxygen and carbon stable isotope compositions. The investigated portion of the core covers the last 14.2 ka BP. The large range in δ18O (11‰) suggests that hydrological conditions exercise the main control on the isotopic composition of the biogenic carbonate in the Valle di Castiglione palaeolake. Samples younger than about 5 ka show a marked 18O depletion, which we attribute to the onset of a temperate wet climate, corresponding to the maximum of humidity. Isotopic results are in good agreement with pollen analyses and prove to be a sensitive tool for reconstructing Quaternary climatic evolution from the continental lacustrine sediments of Central Italy.
Assessment of the impact of past disturbance and prehistoric Pinus sylvestris on vegetation dynamics and soil development in Uragh Wood, SW Ireland
Authors: Little D.J. , Mitchell F.J.G. , von Engelbrechten S. , Farrell E.P.
Published: November 2007

Soil and pollen analysis from an acidophillous oak wood in southwest Ireland are presented. Radio carbon dating provides a temporal scale for pedogenesis and the parallel dynamics of the woodland vegetation. The dominance of Pinus in the wood before 2000 BP, anthropogenic disturbance 300 years ago and intermittent fire are all investigated as causal factors in podzol development at this site. The dominance of Pinus in the wood came to an abrupt end at 1980 BP which is consistent with data from Killarney but at least 2000 years later than the regional decline for the rest of the country. Soil analytical techniques used to investigate pedo genetic processes suggest that podzolization is active and ongoing. However, soil radiocarbon dates suggest that podzolization was initiated prior to c. 700 BP under a mixed forest canopy and before any substantial opening of the canopy due to human impact. Anthropogenic disturbance during the last 300 years has probably accelerated the podzolization process.
A plausible hydrological scenario for the Bølling-Allerød atmospheric methane increase
Authors: Kalin Robert M. , Jirikowic John L.
Published: November 2007

The glacial record has shown that atmospheric methane concentrations have fluctuated in the past, particularly during the Bølling-Allerød interstadial. We used an inverse photochemical carbon- cycle model to interpret the magnitude of effect that glacial-interglacial atmospheric methane variations have on the global carbon cycle. The results of this modelling suggest that an observed variation in atmospheric 14C during this time period may be the result of oxidation of the increased atmospheric methane. We re-examine methane clathrate in palaeosols as a potential source of the methane, and the influence of deglaciation and subsequent heat transport from advecting groundwater in these sediments may be a plausible mechanism by which atmospheric CH4 concentrations abruptly increased during the Bølling-Allerød.
Stable carbon and oxygen isotopic composition of early-Holocene gastropods from Wadi Mansurab, north-central Sudan
Authors: Ayliffe Damien , Williams Martin A.J. , Sheldon Fran
Published: November 2007

The 8500- to 7000-year-old shell-bearing sediments in shallow claypans near Wadi Mansurab in north-central Sudan appear to reflect a widespread and much wetter period in northeast Africa. Stable carbon and oxygen isotope analysis of the Wadi Mansurab gastropods reveals that the shell carbonate is highly depleted in 13C and 18O. The highly depleted oxygen isotopic composition is indicative of rainfall derived from a distant oceanic source. The highly negative nature of the oxygen isotopes indicates that the region had significantly less evaporation than today while the extreme variability in isotopic composition (up to 6-7‰ PDB) is consist ent with a seasonal rainfall regime, characterized by a high degree of inter-annual variability. The dominance of semi-aquatic and swamp-dwelling gastropods over truly aquatic species implies that the region was probably a seasonally flooded grassplain similar to the toich-lands of south-central Sudan today. Our data support the inference that towards 8500-7000 BP there was a stronger southwest monsoon and an associated northward shift in the summer rainfall zone, which caused the Wadi Mansurab region in north-central Sudan to be season ally flooded during a wetter and possibly cooler period with lower rates of evapotranspiration. From 8500 to 7000 BP, lake levels were high elsewhere in northern Africa, suggesting a regionally wetter climate at that time.
Magnetic investigations of framboidal greigite formation: a record of anthropogenic environmental changes in eutrophic Lake St Moritz, Switzerland
Authors: Ariztegui Daniel , Dobson Jon
Published: November 2007

Magnetic minerals found in sediments can either be transported to the basin from the catchment area or can be authigenically formed in the sediments. SEM studies, x-ray diffraction spectra and magnetic mineralogical analyses performed on magnetic extracts from freeze-dried sediments of Lake St Moritz, Switzer land, undoubtedly identified the presence of greigite. The occurrence of this magnetic iron sulphide (Fe3S4) is associated with changing environmental conditions that can be interpreted from historical data available for the area. Results of the combined XRD and SEM study show that authigenically formed greigite in Lake St Moritz sediments displays a predominant framboidal crystal arrangement. Amorphous, irregular shapes and spherical aggregates, most often associated with this mineral, are present in lower concentration. These results provide a natural example of framboidal iron sulphide formation and support previous experimental results that have shown that oxidation state and iron availability are critical factors for greigite formation. Despite its metastable character, greigite can also be preserved in the geological record. Its magnetic signature may, in some cases, be representative of a well-defined depositional environment.
Selective concentration and enumeration of tephra shards from lake sediment cores
Authors: Rose N.L. , Golding P.N.E. , Battarbee R.W.
Published: November 2007

This paper describes a technique for the enumeration of tephra shards from lake sediment cores whereby approximately 85% of unwanted sediment fractions (organic matter, biogenic silica, carbonates) are removed by selective stepwise chemical attack. The order of 100 samples can be prepared simultaneously in a modest-sized water-bath and the recovery rate of the technique is greater than 90%. The procedure is appli cable to all lake sediment types.
Holocene variations of Ameghino Glacier, southern Patagonia
Authors: Aniya Masamu
Published: November 2007

This study reports new data concerning the Holocene glaciation of Ameghino Glacier, an eastern outlet of the Southern Patagonia Icefield. The lowest 7 km of the valley occupied by Ameghino Glacier is now ice-free, of which the upper 3.7 km is a moraine-dammed proglacial lake. Many glacial features are present in the Ameghino Valley. Across the valley floor, four terminal moraines have been identified, each representing a Neoglacial advance. Prominent vegetation trimlines are associated with the youngest of these moraines (M IV) which dammed the proglacial lake. Samples for 14C dating collected at the trimlines and from the valley floors indicate that the formation of M IV, the culmination of the recent maximum glaciation, occurred c. AD 1600-1700, and that deposition of the valley train occurred c. AD 1500. Large standing trees which were buried and killed by this period of deposition have subsequently been exhumed by river erosion. The glacier may have remained at the trimline level until around AD 1870-1880, the date obtained by Nichols and Miller (1951) from dendrochronological analyses. The number of Neoglacial advances (4) identified in the Ameghino Valley is the same as that recently identified at two other Patagonian glaciers, Upsala and Tyndall, and the date of the latest glacial episode, the 'Little Ice Age', is found to be synchronous. However, the ages of the earlier three Neoglacial episodes remain unknown.
A chronogram for postglacial soil-landscape change from the Palliser Triangle, Canada
Authors: Vreeken Willem J.
Published: November 2007

The soil-landscape chronogram summarizes the ways in which five slope-wash erosion cycles followed by two aeolian cycles interrupted postglacial soil formation in an enclosed hillslope system from hummocky moraine terrain. The four slope-wash cycles that followed the early-postglacial cycle occurred between 7.7 and 3 ka BP and caused about half of the total postglacial relief reduction. At the onset of the latter cycles, the locus of erosion switched from its prevalent position on the lower slope to the upper backslope, indicating recurrent fundamental changes in slope hydrology. The ensuing stratigraphic framework has a downslope thickening and fining clastic wedge, grading into the bottomland sequence and subdivided by soil catenas that merge upslope into a single compound mantle on the upland. The aeolian cycles entailed localized loess-dispersal systems, producing minor mantles of sandy-loam loess with saltation-load deposits on the leeward slope and suspension-load deposits elsewhere. Accumulation of long-range calcareous dust during the loess cycles supplied most of the secondary carbonates found in the buried soils. Three radiocarbon dates, together with Mazama tephra, enable partial correlation of these events to the regional Holocene-climate record.
Sedimentary records of the extent and impact of atmospheric contamination from a remote Siberian highland lake
Authors: Flower R.J. , Politov S.V. , Rippey B. , Rose N.L. , Appleby P.G. , Stevenson A.C.
Published: November 2007

The Central Asian Khamar Daban Mountain Range (SE Siberia) is a remote region with softwater lakes that probably receive atmospheric pollution from local industry as well as via long-distance transport. Palaeolimnological evidence of the impact of atmospheric pollution at one isolated and otherwise undisturbed highland site in the Khamar Daban, Lake Kholodnoye, was obtained. Short sediment cores were analysed for radio-isotopes, to establish a sediment chronology. The sediment accumulation rate in core KOL1 is slow (4 mg dry sediment cm-2 yr-1, or 0.3 mm yr-1) but trace metal (notably Pb and Zn) and spheroidal carbonaceous particle profiles show increases beginning at 2-cm (1920s) and 1.3-cm (1940s) depth, respectively. The trace metal profiles are essentially corroborated by KOL2, a replicate core analysed at a Russian laboratory. Diatom analysis revealed no evidence of recent acidification or indeed of any marked floristic change during the twentieth century (upper 2.5 cm of sediment). Lack of catchment disturbance was indicated by very uniform pollen frequencies throughout the core. Lake-water chemistry indicated an excess of sulphate. Both the diatom and base cation stratigraphies showed a small but sustained change over the entire 28 cm of the core. Maximum floristic change in sedimentary diatom assemblages occurred around 7 cm sediment depth, approximately dated to the mid-eighteenth century. Small but gradual up-core increases in Na, K and Mg indicate a disturbance in the delivery of minerals from the catchment to the lake. The sedimentary profiles of trace metals and spheroidal carbonaceous particles show that the site is contaminated by low-level but nevertheless significant atmospheric pollution. This contamination occurred during the twentieth century. Small changes in the diatom and other geochemical sedimentary records predate these industrial impacts and so could reflect longer-term catchment weathering processes and/or indirect effects of climate change.
Estimating vertical tectonic movement using sediment texture
Authors: Dunbar G.B. , Barrett P.J. , Goff J.R. , Harper M.A. , Irwin S.L.
Published: November 2007

We demonstrate a new method of detecting, and quantifying, vertical sea-floor movements caused by tectonic uplift from a large earthquake, based on grain-size data from two cores from Petone foreshore, Wellington Harbour, New Zealand. An earthquake of magnitude 8+ raised the shores of Wellington Harbour about 2 m in AD 1855, according to historical records. This event has been recognized in two nearshore cores as a sharp decrease in mud content of 15-20% at 3.75 and 4.25 m below the sea floor (bsf). The decrease is attributed to decreased water depth resulting in higher nearshore wave-induced energy levels. The two levels in the core have been dated approximately by 14C, palynology and variations in heavy metal concentrations and are consistent with a date of AD 1855 for the abrupt shallowing of the foreshore. We infer that the mud-depth relationship has probably been affected since European colonization (post-AD 1840) by increased sediment input into the harbour. Chronological markers in the two cores suggest that rates of sediment accumulation have increased by a factor of at least ten, from ∼2 mm yr-1 prior to AD 1855 to 30 mm yr-1 since then.
Ice-flood history reconstructed with tree- rings from the southern boreal forest limit, western Québec
Authors: Tardif Jacques , Bergeron Yves
Published: November 2007

Historic ice-flood frequency and lake levels were reconstructed for the southern limit of the boreal forest in western Québec by dendrochronological analyses of ice-scarred white cedar (Thuja occidentalis L.) trees growing on the shore of Lake Duparquet. Results reveal a significant increase in major ice floods since the end of the 'Little Ice Age' and, in particular, since the beginning of this century. This rise was also not related to oversampling of younger scarred trees. In addition, time between white-cedar establishment and the first recorded scar has significantly decreased in the last 200 years, and this applies for trees occupying similar topographic conditions. White cedar's increased exposure, in the 150 years, to scarring strongly suggests that Lake Duparquet water levels at breakup are reaching higher elevations. This is supported by an approximate 100-cm rise in maximum ice-scar height since the end of the 'Little Ice Age'. Years leading to abundant ice scars are those with heavy winter and spring precipitation. Cold Novembers and rainy Aprils also favour major ice-flood episodes. Earlier spring melts could also favour pre-mature ice breakup; a situation that may cause higher-amplitude ice floods. Since the 'Little Ice Age', greater penetration of warm and humid air from the south resulting from a northward migration of the Arctic front may be responsible for the increasing major ice floods registered at Québec's southern boreal forest limit.
Mid- and late-Holocene sea-level changes in Roudsea Marsh, northwest England: a diatom biostratigraphical investigation
Authors: Yongqiang Zong
Published: November 2007

Diatoms, vascular vegetation, sediment data and water salinity from contemporary intertidal environ ments in Roudsea Marsh, northwest England, are used to define altitudinal relationships between diatom assem blages and reference water levels. Comparison of these data with the high-resolution diatom biostratigraphy of a fossil marsh sequence allows identification of fluctuations of relative sea level in the mid- and late Holo cene. Two oscillations in relative sea level are recorded. A rise in sea level (> 0.6 m) led to the inundation of the site after 6000 BP and was followed by a fall in sea level (c. 1 m) around 4700 BP. A second rise in sea level (> 0.5 m) occurred before 2420 BP and was followed by a relatively stable or smaller rise of sea level during the last millennium. The use of diatom groups based on marsh altitude was successful.
Seasonality in late-Holocene climate from ice-core records
Authors: Morgan Vin , van Ommen Tas D.
Published: November 2007

High-resolution ice-core δ18O data from a site with well preserved seasonal cycles are used to extract seasonal temperature trends over the last 700 years with an effective resolution of a few months. Examination of this record on timescales of decades to centuries shows distinctly different patterns of temperature variation between summer and winter. Over the last 700 years, the summer months show relatively little change, with the coolest summers occurring early this century. The winters, in contrast, show significant fluctuations including a period of warmer temperatures between AD 1400 and 1500 and a colder period centred around the early 1800s which corresponds to the latter part of an era of glacier advance and cold winters in Europe sometimes known as the 'Little Ice Age' (LIA). Since many proxy temperature indicators respond principally to seasonal extremes, they will consequently give biased results in the presence of seasonally confined trends. This may account for the fact that events such as the LIA do not appear in some records.
A multiproxy approach to the function of postmedieval ridge-and-furrow cultivation in upland northern Britain
Authors: Carter Stephen , Tipping Richard , Davidson Donald , Long Deborah , Tyler Andrew
Published: November 2007

The remains of agricultural activity preserved beneath current rough pasture in the uplands of Tweed dale in southern Scotland are subjected to multidisciplinary analysis by archaeological survey, documentary research, and palaeoecological reconstruction through pollen analysis, supported by 210Pb and other forms of dating. The survey showed the features to represent grooved rig, a form of ploughing presumed to be related to cereal cultivation in the medieval and postmedieval periods. Documentary and pollen analyses suggest, however, that the ploughing is very recent, of nineteenth-century date, and represents a form of pasture improve ment for sheep grazing. This conclusion demonstrates the value of multidisciplinary research based on this type of evidence, and has implications for the interpretation of comparable forms of upland agriculture.
Statistical models for PET and SPECT data
Authors: Kay Jim
Published: November 2007

This article outlines the statistical developments that have taken place in emission tomography during the past decade or so. We discuss the statistical aspects of the modelling of the projection data and define the additive Poisson regression model. This leads to the use of the method of maximum likelihood as a means of estimating the underlying isotope concentration within a given region of a patient's body, and to the use of the EM algorithm to compute the reconstruction. The need for the regularization of the maximum likelihood solution is tackled using Bayesian techniques. A number of algorithms for the computation of regularized solutions are outlined. The issue of parameter estimation is discussed and some open issues are mentioned.
Screening for stratification in two-phase ('two- stage') epidemiological surveys
Authors: Pickles Andrew , Dunn Graham , Vázquez-Barquero José Luis
Published: November 2007

Screening is undertaken not only for the purpose of giving therapeutic treatment to those among screen positive subjects found to be diagnosis positive, but it is also used in epidemiology as the first phase of multi-phase sampling designs. We review the use of such designs in epidemiology, and in psychiatric epidemiology in particular, focusing on two-phase or double sampling. We then compare a variety of approaches to the statistical analysis of data from such designs including the use of sampling weights, Gibbs sampling, full maximum likelihood for random effects logistic regression and a simple E-M algorithm for incomplete data. The methods are illustrated using data from a recent multi-phase study of psychiatric morbidity in northern Spain.
Study design for epidemiologic studies with measurement error
Authors: Holford Theodore R. , Stack Catharine
Published: November 2007

Exposure measurement error in epidemiological studies is recognized as a feature that must be considered because of the potential bias that can result in estimates of the exposure-disease association. Most of the work to date has focused on methods of analysis that adjust for the resultant bias, but the implications of this work to the design of epidemiologic studies is not as well understood. An overview of the issues involved in the use of methods for dealing with errors in exposure information is discussed along with some design options that have been proposed for providing information necessary for their use. Validation studies compare somewhat crude and inexpensive measures of exposure to a gold standard, and study designs that incorporate these into the overall plan can realize some advantages in terms of cost. In addition, repeated assessments of exposure can realize efficiency for measures of exposure that are unbiased. However, much work remains to be done in the development of efficient designs for studying disease aetiology and prevention.
Engineered-to-order Approach for Providing Flexibility in e-Commerce of Mold Parts
Authors: Mun Duhwan , Jang Kwangsub , Han Soonhung , Kim Junhwan , Hwang Ho-Jin
Published: November 2007

In the mold parts industry, customers typically place orders for order-made parts with some changes to the design specifications of ready-made parts within the extent of the manufacturing capability of the supplier. Being customized for ready-made parts, existing e-Catalog systems cannot support this trade pattern. To solve this problem, an engineered-to-order (ETO) approach is proposed here, enabling the trade of order-made parts in an e-Catalog system by utilizing the design and manufacturing knowledge of part suppliers. After addressing technological challenges and their solutions, we describe application results of the ETO approach to two types of mold parts — ejector pins and mold bases.
The Role of Thymidine Phosphorylase and Thrombospondin-1 in Angiogenesis and Progression of Intrahepatic Cholangiocarcinoma
Authors: Aishima Shin-ichi , Taguchi Ken-ichi , Sugimachi Keishi , Asayama Yoshiki , Nishi Hidehiro , Shimada Mitsuo , Sugimachi Keizo , Tsuneyoshi Masazumi
Published: November 2007

Thymidine phosphorylase (TP), an important regulator of angiogenesis, is correlated with progression, metastasis, and prognosis in various types of tumor. In contrast, both positive and negative effects of thrombospondin-1 (TSP-1) on angiogenesis have been reported. In the present study, we examined the expression of TP and TSP-1 in carci noma cells in 67 primary intrahepatic cholangiocarcinomas (ICCs) immunohistochem ically and its correlation with angiogenesis, clinicopathological features, and prognosis. Ttwenty-six (38.8%) cases were classified as exhibiting positive TP expression. TP ex pression showed a significant correlation with vascular invasion, lymphatic perme ation, perineural invasion, and lymph node metastasis. Thirty-four (50.7%) cases were classified as exhibiting positive TSP-1 expression. TSP-1 expression was significantly correlated with only lymphatic permeation. The microvessel count in positive TP ex pression cases was significantly higher than that in negative cases. In contrast, the mi crovessel count in negative TSP-1 expression cases was significantly higher than that in positive cases. Survival in patients who were positive for both TP and TSP-1 expression was significantly poor. Our results suggest that the increased TP expression and de creased TSP-1 expression contribute to angiogenesis, but that the role of angiogenesis in ICC is not closely related to tumor aggressiveness. The TP and TSP-1 expression in ICC may enhance tumor aggressiveness. Int J Surg Pathol 10(1):47-56, 2002
Dedifferentiated Liposarcoma of the Pyriform Sinus
Authors: Gonzalez-Lois Carmen , Ibarrola Carolina , Ballestin Claudio , Martínez-Tello Francisco J.
Published: November 2007

Laryngeal and hypopharyngeal liposarcomas are extraordinarily infrequent tumors. To the best of our knowledge there are fewer than 40 well-documented cases re ported to date. Almost all of them are well-differentiated liposarcomas, with only 2 laryngeal-hypopharyngeal dedifferentiated liposarcomas. Dedifferentiated liposar coma is defined as a well-differentiated liposarcoma with areas of high-grade spindle cell nonlipogenic sarcoma. The well-differentiated areas may be of a lipoma like, sclerosing, or mixed type, and the dedifferentiated areas most frequently are of malignant fibrous hystiocytoma-like type. Despite its commonly pleomorphic his tology, dedifferentiated liposarcoma does not behave as aggressively as most pleo morphic sarcomas of adulthood; however, it has the capacity to metastasize, in contrast to its well-differentiated counterpart. We present a case of dedifferentiated liposarcoma arising in the pyriform sinus, an event only twice reported previously in the literature. Int J Surg Pathol 10(1):75-79, 2002
Absence of Expression of c-sis and Transforming Growth Factor-β mRNA in Malignant Fibrous Histiocytoma
Authors: Frank Thomas S. , Reed John C. , Brooks John S. J.
Published: November 2007

Total RNA was extracted from five malignant fibrous histiocytomas and two benign fibrohistiocytic lesions and assayed for mRNA expressions for transforming growth factor beta (TGF-β) and c-sis by Northern blot analysis. Production of both of these has been associated with cells of monocyte-macrophage lineage, and these factors have been shown to be important in physiologic mesenchymal cell proliferation. No mRNA expression of either TGF-β or c-sis was identified in any of the fibrohistiocytic tumor samples. The lack of expression of TGF-β and c-sis may be consistent with a nonhistiocytic origin of malignant fibrous histiocytoma, or may reflect transformation- associated loss of the normal molecular mechanisms of mesenchymal proliferation. The absence of c-sis mRNA expression can be reconciled with the prior immunohisto chemical demonstration of platelet-derived growth factor in tumor cells of malignant fibrous histiocytoma. Int J Surg Pathol(2):117-122, 1993
Soft Tissue Leiomyoma With Cartilaginous Metaplasia
Authors: Khalluf Edgar , DeYoung Barry R. , Swanson Paul E.
Published: November 2007

A 42-year-old woman presented with right leg pain of 4 years' duration without a palpable mass. Magnetic resonance imaging showed a soft tissue mass adjacent to the posterior aspect of the proximal fibula that appeared to arise from the belly of the gastrocnemius muscle. Excisional biopsy showed a well-circumscribed tumor mass composed of fascicles of spindled smooth muscle cells intimately admixed with islands of larger, epithelioid cells in an extracellular basophilic matrix reminiscent of immature cartilage. Other areas resembled maturing hyaline cartilage. Immunohistochemical staining and electron microscopy were utilized to verify the presence of the two distinct cell types within this tumor. Review of the literature suggested that this case represents the first well documented case of cartilaginous metaplasia in a deeply situated soft tissue leiomyoma. Int J Surg Pathol 1(4):235-238, 1994
Role of Polymerase Chain Reaction in the Diagnosis of Cytomegalovirus Infection in Liver Transplant Patients
Authors: DelBuono Elizabeth A. , Appelman Henry D. , Frank Thomas S.
Published: November 2007

Eighty-eight formalin-fixed, paraffin-embedded needle biopsies from 58 liver trans plant recipients were analyzed for the presence of cytomegalovirus (CMV) by light microscopy and the polymerase chain reaction (PCR). Twenty-seven biopsies were positive for CMV by both light microscopy and PCR, 41 were negative by both methods, 17 were positive by PCR only, and 3 were positive by light microscopy only. In the absence of cytomegalic cells, immunohistochemical staining was unable to detect CMV that could have been identified by PCR. Serum total bilirubin was higher in patients whose biopsies contained PCR (but not histologic) evidence of CMV infection. No evidence of association of the presence of CMV was found by either PCR or light microscopy with serum levels of aminotransferase or alkaline phosphatase, nor with histologic evidence of rejection or hepatitis. PCR was negative for CMV in 22 liver biopsies from immunocompetent individuals without evidence of hepatic dysfunction. Although PCR can detect the presence of CMV in the absence of cytomegalic cells, the clinical significance of PCR-proven, histologically undetectable CMV in the liver is undetermined. Int J Surg Pathol 2(3):221-226, 1995
Small Cell Carcinoma of the Prostate
Authors: Aqel N.M. , El-Hady S. , Henry K. , Quigley M. , Hanham I.
Published: November 2007

An 82-year-old man, who 7 years previously had been treated for adenocarcinoma of the prostate, was found to have developed a small cell (oat cell) carcinoma of prostate, which presented with liver metastases. The expression of different neuroendo crine markers in these carcinomas is presented, the histogenesis of small cell carcinoma is discussed, and the relevant literature is reviewed. The importance of the recognition of small cell carcinoma of the prostate is emphasized because of the influence of small cell carcinoma on the prognosis. Int J Surg Pathol 2(3):237-244, 1995
p53 Expression in Endocervical and Endometrial Adenocarcinomas
Authors: McHugh Mary , Bose Shikha , Palazzo Juan P.
Published: November 2007

The expression of monoclonal antibody p53 (PAb 1801) was studied by immunohisto chemistry in 16 endocervical and 28 endometrial adenocarcinomas. Eight endocervical and 17 endometrial carcinomas were p53 positive. The nuclear staining varied from focal to diffuse strong positivity. Follow-up information was obtained in 24 patients with endometrial tumors and in 10 patients with endocervical tumors. Of the 2 patients with endocervical tumors who died with disease, 1 showed strong p53 positivity while the other case was negative. Of the 8 patients with endometrial carcinoma who died, 6 showed positivity for p53 and 2 were negative. A significant correlation in intensity of staining was observed between well- and poorly differentiated endometrial adenocarcinomas (P < .001); however, this correlation was not observed in endocervical carcinomas. Int J Surg Pathol 2(4):269-274, 1995
Proliferating Cell Nuclear Antigen (PCNA) Immunoexpression in Hyperplastic Polyps and Adenomas of the Appendix
Authors: Carr N.J. , Albahra M.A. , Nzeako U.C. , Sobin L.H.
Published: November 2007

The aim of this study was to compare proliferating cell nuclear antigen (PCNA) immunoexpression in hyperplastic polyps and adenomas of the human vermiform appendix. We used the monoclonal antibody PC 10 in 13 hyperplastic polyps, 27 vil lous adenomas, and 13 adenomas with undulating or flat epithelium. In both the hyperplastic polyps and the villous adenomas, the labeling indices were significantly greater in the lower third than in the upper third. The labeling indices of the flat/undulating adenomas resembled those of the upper third of the villous adeno mas. In contrast to previous findings in colorectal adenomas, there were no signifi cant differences in labeling indices between the hyperplastic polyps and the villous adenomas. We concluded that PCNA labeling indices are unlikely to be of value in the distinction between villous adenomas and hyperplastic polyps in the appendix. The results may reflect the different spectrum of appendiceal adenomas versus col orectal adenomas. Int J Surg Pathol 2(4).-2 75-280, 1995
MIB-1 Is a Suitable Marker of Proliferative Activity in Formalin-fixed, Paraffin-embedded Sections of Breast Cancer
Authors: Schmitt Fernando Carlos , Ferreira Marcia Pitombeira
Published: November 2007

To investigate the expression of a marker of cell proliferation (MIB-1) and its puta tive relationship with tumor size, histologic grading, mitotic index, nodal status, estrogen receptor content, p53 immunoreactivity, and ploidy, we studied 40 cases of invasive breast carcinoma in formalin-fixed, paraffin-embedded tissue sections. The MIB-1, estrogen receptor, and p53 were detected using an avidin-biotin-peroxidase method with microwave antigen retrieval. Ploidy was assessed by image analysis. The median value of MIB-1 index was 15.9% and ranged from 5% to 90%. We found a significant and positive relationship among the MIB-1 index and histologic grading, mitotic index, p53 immunoreactivity, and ploidy, and we demonstrated an inverse relationship between the MIB-1 index and estrogen receptor content. These " results are similar to those reported using Ki-67 in frozen sections from breast car cinomas. Thus, MIB-1 detected in formalin-fixed material with microwave pre treatment looks to be a reliable marker of proliferation in breast carcinomas. Int J Surg Pathol 2(4):287-294, 1995
Is There a Correlation Between Histology and Karyotype in Early Spontaneous Abortion?
Authors: Fukunaga Masaharu , Onda Takekazu , Endo Yasuhiko , Ushigome Shinichiro
Published: November 2007

The value of histologic evaluation of placental tissue in spontaneous abortions remains undefined. We analyzed 90 placentas from early spontaneous abortions to ascertain if morphologic features were predictive of karyotype. Normal karyotypes were observed in 40 cases, and abnormal karyotypes were found in 50. There were 25 trisomies, 6 triploidies, 2 tetraploidies, one 45, × 0, and 16 other abnormalities, such as mosaic and chimera. All 6 triploid placentas were partial moles. The pres ence of intravillous cistern formation and focal trophoblastic hyperplasia was seen more frequently in cases with abnormal karyotypes. The triploid cases, however, contributed the majority of cases with these villous changes. Hydropic abortion was observed approximately equally in both chromosomally normal and abnormal cases, and its incidence was high in cases of trisomy 16 and tetraploid placenta. Mild edema and regressive changes, such as stromal fibrosis, hypovascular stroma, and attenuated trophoblastic layers, were often found and none showed any specific chromosomal abnormalities. These results indicate that histology can provide only a suggestion as to the likelihood of triploidy and that histologic examination of spontaneous abortions is not useful as a method for predicting chromosomal abnor mality. Int J Surg Pathol 2(4):295-300, 1995
Acute Renal Failure After Cardiopulmonary Bypass: A Possible Association With Drugs of the Fibrate Group
Authors: Sharobeem Kamel M. , Madden Brendan P. , Millner Russell , Rolfe Lindsey M. , Seymour Carol A. , Parker John
Published: November 2007

Background: Renal failure is a recognized, but infrequent, complication following cardiac surgery. The causes for this condition are multifactorial, and a major concern is that the occurrence of postoperative acute renal failure is still associated with a high mortality rate.

Methods and Materials: We report unexpected acute renal failure occurring in 4 patients after uncomplicated cardiac surgery. Each patient was taking a fibric acid derivative at the time of surgery. Renal failure occurred rapidly within 3 days of surgery and was associated with increased concentrations of skeletal muscle-derived creatine kinase (CK). One patient devel oped myoglobinuria, and another developed a malignant hyperthermia-like syndrome.

Conclusions: These cases show that patients receiving lipid lowering medications could be at higher risk of developing acute renal failure after cardiac surgery. This association merits careful evaluation in large prospective studies and, if proved, would suggest that patients taking either statins or fibrates should discontinue doing so before cardiac surgery.
A Randomized Multicenter Trial Comparing the Efficacy of Simvastatin and Fluvastatin
Authors: Illingworth D.R. , Stein E.A. , Knopp R.H. , Hunninghake D.B. , Davidson M.H. , Dujovne C.A. , Miller V.T. , Tobert J.A. , Laskarzewski P.M. , Isaacsohn J.L. , Bacon S.P. , Tate A.C.
Published: November 2007

Background: Inhibitors of hydroxymethylglutaryl co-enzyme A reductase are widely used for the treatment of hypercholesterolemia. Physicians and third-party payers need an accurate measure of their relative potency and hypolipidemic efficacy. We have therefore compared simvastatin against fluvastatin, the newest member of this class.

Methods and Results: One hundred fifty-eight hypercholesterolemic patients in seven United States lipid clinics participated in this balanced double-blind incomplete block study. After a placebo-diet run-in period, patients received treatment with active drug for three con secutive 5-week periods, with measurement of lipids in a NHLBI-CDC standardized central laboratory at the end of each period. Each patient was randomly assigned to three of the fol lowing five treatments: simvastatin 5 mg, 10 mg, and 20 mg and fluvastatin 20 mg and 40 mg. The mean percent reductions in low density lipoprotein cholesterol from baaeline were 21, 27, 32, 16, and 23 respectively. The simvastatin/fluvastatin milligram potency ratio was 6.8 (95% CI, 5.3-9.3). At the same 20 mg dosage, simvastatin produced an effect on LDL cholesterol approximately double that of fluvastatin and resulted in 46% of patients achieving their National Cholesterol Education Program low density lipoprotein cholesterol target levels, compared to 12% for fluvastatin.

Conclusions. Fluvastatin at its maximal dose of 40 mg daily is approximately equivalent to simvastatin 5 mg daily. Higher doses of simvastatin are considerably more effective in the treatment of primary hypercholesterolemia.
Differences in the Effects of d- and dl-Sotalol on Isolated Human Ventricular Muscle: Electromechanical Activity After Beta-Adrenoceptor Stimulation
Authors: Lathrop David A. , Varró András , Nánási Péter P. , Bódi Ilona , Takyi Eric , Pankucsi Csaba
Published: November 2007

Background: The racemate of sotalol ( dl-sotalol) and its dextrorotatory isomer ( d-sotalol) are equally effective in increasing isolated cardiac action potential durations. dl-Sotalol, however, is reported to be more effective than d-sotalol in increasing ventricular effective refractoriness following coronary artery occlusion. These differences are attributed to the beta-adrenergic blocking properties of dl-sotalol. We wished to determine if in isolated human ventricular muscle preparations the effects of 30 μM d- and dl-sotalol could be modified by preexposure to 1 μM isoproterenol.

Methods and Results: Microelectrodes were used to record action potential duration (APD) in the presence and absence of isoproterenol during continuous pacing. Preparations were obtained from explanted hearts of transplant recipients suffering idiopathic cardiomyopathies. Without isoproterenol, APD measured at 90% of repolarization (APD90) was signiticantly increased by both d- and dl-sotalol (352.0 ± 17.7 to 418.0 ± 23.8 ms, P < .05; and 339.2 ± 17.0 to 405.0 ± 25.3 ms, P < .05; respectively). Isoproterenol alone, prior to sotalol exposure, tended to shorten APD90 in the two groups first exposed to this beta-aclenoceptor agonist and subsequently exposed to either d-sotalol or dl-sotalol (317.5 ± 16.5 to 286.2 ± 28.8 ms and 288.0 ± 16.2 to 254.0 ± 15.0 ms, respectively). dl-Sotalol signiticantly increased APD90 from its baseline value after isoproterenol (288.0 ± 16.2 to 359.0 ± 25.1 ms, P < .005) while d-sotalol did not (317.5 ± 16.5 to 316.2 ± 28.5 ms, NS).

Conclusions: The beta-adrenergic blocking properties of dl-sotalol may be important in determining antiarrhythmic efficacy when tonic sympathetic nervous activity is high.
Amiodarone Therapy After Previous Sotalol-induced Torsade de Pointes: Analysis of QT Dispersion to Predict Proarrhythmia
Authors: van de Loo Andreas , Klingenheben Thomas , Hohnloser Stefan H.
Published: November 2007

Background: Polymorphic ventricular tachycardia of the torsade de pointes type represents, potentially, the most dangerous side effect of antiarrhythmic drugs that prolong ventricular repolarization. Much effort has been devoted to the identification of the degree of drug-asso ciated QT prolongation that might predict the occurrence of torsade de pointes. However, there is still no general agreement as to which level of QT prolongation might be the harbinger of torsade and which may simply represent the manifestation of the class III antiarrhythmic effect of a given compound.

Methods and Results: A 70-year-old woman who had survived an episode of cardiac arrest outside of a hospital was treated with dl-sotalol (320 mg/d). After 8 days of therapy, she devel oped two episodes of hemodynamically unstable torsade de pointes. Sotalol was withdrawn and after extensive diagnostic work, therapy with amiodarone was instituted. Despite the fact that the degree of QT prolongation observed during amiodarone therapy was comparable to that observed during sotalol exposure, the patient tolerated amiodarone and is now free of recurrent ventricular tachyarrhythmias over a follow-up period of I year. Analysis of QT dis persion in the surface electrocardiograph revealed a marked increase during sotalol therapy but not during amiodarone administration (77 vs 47 ms). During drug-free control, QT dis persion was 43 ms.

Conclusions: These findings emphasize the potential usefulness of determination of QT dis persion from the surface ECG to assess disparity in ventricular recovery, which is known to favor the occurrence of torsade de pointes. These observations need to be corroborated in large prospective trials. Finally, this case report further emphasizes the low arrhythmogenic potential of amiodarone—an unexplained paradox, the understanding of which might provide insights for the development of newer antifibrillatory compounds.
Data-driven Decisions: The Importance of Clinical Trials in Arrhythmia Management
Authors: Reiffel James A.
Published: November 2007

As a result of clinical trials, the management of arrhythmias has evolved over the past three decades. In the late 1960s, customary teaching was that ventricular premature depolarizations were dangerous and antiarrhythmic therapy, in hopes of reducing fatal consequences, became common place; however, following clinical trials such as CAST, IMPACT, and SWORD, we learned that, at least in postinfarct patients, arrhythmia suppression may lead to increased rather than reduced mortality. Such trials have led to a marked reduction in therapy of indiscriminate ventricular ectopy and have led to ongoing testing of specific subgroups identified as having par ticularly high adverse prognostic risk. With the advent of cardiac monitoring and the confirma tion that ventricular tachyarrhythmias are the most common cause for sudden death, their therapy, too, has evolved and matured, again aided by clinical trials. The ESVEM study prospec tively examined the role of monitor-guided versus electrophysiologically guided drug therapy of ventricular tachyarrhythmias and confirmed that both approaches may have a role in reducing arrhythmic deaths—though the specific benefits of each technique remain somewhat unsettled. Both the ESVEM and CASCADE studies suggested that the most effective drugs for ventricu lar tachyarrhythmias are the class II/III drugs, sotalol and amiodarone, both appearing more effective than our older class I agents. These should now be viewed as the first-line drugs for these arrhythmias. The relative benefits of these two agents with respect to each other and to implantable cardioverter detibrillators, however, remains to be determined by further clinical tri als, such as AVID and CIDS. The therapy of atrial tachyarrhythmias has similarly evolved with the aid of clinical observations. While rate control is required in all patients with atrial fibrilla tion, we have come to realize that the applications of antiarrhythmic drugs for the purpose of maintaining sinus rhythm must be used only selectively rather than uniformly. Both a meta-anal ysis by Coplen and colleagues and a report by the SPAF investigators suggested that with atrial arrhythmias, too, antiarrhythmic drug therapy may result in enhanced rather than reduced mor tality in some circumstances. Additional clinical trials are needed to further elucidate the role of antiarrhythmic therapy of atrial fibrillation.