Etiology in a taxonomy of illnesses

According to what Robert Koch termed the etiological standpoint, illnesses are best understood and controlled by focusing on their causes, including in their definitions and, thus, in the construction of their taxonomies. In some ways flawed, this standpoint has been misunderstood and misapplied. A taxonomy based solely on etiology was an unrealistic dream in the context of 'the bacteriological revolution', and it also is unrealistic in the present context of 'the genetic revolution.' We argue that the illnesses in a taxonomy of them are in some cases best defined directly in terms of their respective somatic anomalies, in some others indirectly by the unique and universal etiology of that anomaly (left unspecified) in a 'deeper' somatic anomaly, and in yet others as a combination of these; and when the somatic anomaly for direct definition remains unknown, it is to be defined indirectly by the clinical syndrome that is its patient-relevant manifestation, possibly in conjunction with a somatic cause. We note, also, that these taxonomic issues have no material bearing on epidemiologists' etiologic research for the knowledge base of community-level preventive medicine.

Cytogenetics of pineoblastoma: four new cases and a literature review

Pineoblastoma represents a class of primitive neuroectodermal tumors (PNET) with poorly differentiated neuroepithelial cells that are histologically indistinguishable from medulloblastomas. It is a rare tumor, typically arising in childhood, and to date only a few cytogenetic cases have been published. We report four new cases in which conventional cytogenetics demonstrated the presence of an abnormal clone. The tumors showed a variety of ploidy levels, from hypodiploid to hypertetraploid. Both structural and numerical aberrations were frequent, and in three out of the four cases a large degree of cell-to-cell variation was observed. The most frequently involved chromosome in structural rearrangements was chromosome 1, observed in three of the four cases. The short arm was involved in two of the three cases; in the third case, the anomaly was in the long arm. Two cases showed unbalanced gain of chromosome 17q, one of them showing i(17)(q10). Together, the four cases illustrate the complex karyotypic nature of this tumor type and represent a step toward determining whether a nonrandom cytogenetic picture exists and how this may be related to other associated tumor types.

Congenital hypotrichosis and partial anodontia in a crossbred beef calf

Clinical examination, skin biopsies, skull radiographs, and DNA analysis of a 2-day-old Red Angus-Charolais-Simmental cross bull calf confirmed the diagnosis of congenital hypotrichosis and anodontia defect (HAD), also called anhidrotic ectodermal dysplasia, which is a rare anomaly caused by a deletion in the bovine EDA gene on the X chromosome.

Rosette-forming glioneuronal tumor of the fourth ventricle: Report of two cases with a differential diagnostic overview

We report on clinicopathological findings in two cases of rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) occurring in females aged 16 years (Case 1) and 30 years (Case 2). Symptoms included vertigo, nausea, cerebellar ataxia, as well as headaches, and had been present for 4-months and 1 week, respectively. Magnetic resonance imaging (MRI) indicated a cerebellar-based tumor of 1.8cm (Case 1) and 5cm (Case 2) diameter each, bulging into the fourth ventricle. Case 2 involved a cyst-mural-nodule configuration. In both instances, the solid component appeared isointense on T(1) sequences, hyperintense in the T(2) mode, and enhanced moderately. Gross total resection was achieved via suboccipital craniotomy. However, functional recovery was disappointing in Case 1. On microscopy, both tumors comprised an admixture of low-grade astrocytoma interspersed with circular aggregates of synaptophysin-expressing round cells harboring oligodendrocyte-like nuclei. The astrocytic moiety in Case 1 was nondescript, and overtly pilocytic in Case 2. The architecture of neuronal elements variously consisted of neurocytic rosettes, of pseudorosettes centered on a capillary core, as well as of concentric ribbons along irregular lumina. Gangliocytic maturation, especially "floating neurons", or a corresponding immunoreactivity for neurofilament protein was absent. Neither of these populations exhibited atypia, mitotic activity, or a significant labeling for MIB-1. Cerebellar parenchyma included in the surgical specimen did not reveal any preexisting malformative anomaly. Despite sharing some overlapping histologic traits with dysembryoplastic neuroepithelial tumor (DNT), the presentation of RGNT with respect to both patient age and location is consistent enough for this lesion to be singled out as an autonomous entity.

Prevalence of heart disease in symptomatic cats: an overview from 1998 to 2005

A total of 408 cats with various cardiovascular problems has been presented to two investigational clinics during the last 8 years. The number of yearly examinations has steadily increased during this period. Definitive cardiovascular disease was diagnosed in 287 cats, whereby hypertrophic cardiomyopathy (HCM) was the most common diagnosis with 67.6%. Congenital cardiovascular malformations were found in 11.8% of the cases. Ventricular septal defect (VSD) was the most frequent anomaly, in contrast to previously published studies. The ECG was found to be relatively non-specific and insensitive for the diagnosis of heart disease: Its usefulness lies in the recognition and diagnosis of cardiac arrhythmias. The radiographically recognized changes were also non-specific for certain heart diseases. Radiographs of the thorax are especially useful in the evaluation of cardiomegaly, and secondary signs of congestion.

Synchronisation of the EDML and EDC ice cores for the last 52 kyr by volcanic signature matching

A common time scale for the EPICA ice cores from Dome C (EDC) and Dronning Maud Land (EDML) has been established. Since the EDML core was not drilled on a dome, the development of the EDML1 time scale for the EPICA ice core drilled in Dronning Maud Land was based on the creation of a detailed stratigraphic link between EDML and EDC, which was dated by a simpler 1D ice-flow model. The synchronisation between the two EPICA ice cores was done through the identification of several common volcanic signatures. This paper describes the rigorous method, using the signature of volcanic sulfate, which was employed for the last 52 kyr of the record. We estimated the discrepancies between the modelled EDC and EDML glaciological age scales during the studied period, by evaluating the ratio R of the apparent duration of temporal intervals between pairs of isochrones. On average R ranges between 0.8 and 1.2 corresponding to an uncertainty of up to 20% in the estimate of the time duration in at least one of the two ice cores. Significant deviations of R up to 1.4–1.5 are observed between 18 and 28 kyr before present (BP), where present is defined as 1950. At this stage our approach does not allow us unequivocally to find out which of the models is affected by errors, but assuming that the thinning function at both sites and accumulation history at Dome C (which was drilled on a dome) are correct, this anomaly can be ascribed to a complex spatial accumulation variability (which may be different in the past compared to the present day) upstream of the EDML core.

Myocardial bridging: depiction rate and morphology at CT coronary angiography--comparison with conventional coronary angiography

PURPOSE: To prospectively assess the depiction rate and morphologic features of myocardial bridging (MB) of coronary arteries with 64-section computed tomographic (CT) coronary angiography in comparison to conventional coronary angiography. MATERIALS AND METHODS: Patients were simultaneously enrolled in a prospective study comparing CT and conventional coronary angiography, for which ethics committee approval and informed consent were obtained. One hundred patients (38 women, 62 men; mean age, 63.8 years +/- 11.6 [standard deviation]) underwent 64-section CT and conventional coronary angiography. Fifty additional patients (19 women, 31 men; mean age, 59.2 years +/- 13.2) who underwent CT only were also included. CT images were analyzed for the direct signs length, depth, and degree of systolic compression, while conventional angiograms were analyzed for the indirect signs step down-step up phenomenon, milking effect, and systolic compression of the tunneled segment. Statistical analysis was performed with Pearson correlation analysis, the Wilcoxon two-sample test, and Fisher exact tests. RESULTS: MB was detected with CT in 26 (26%) of 100 patients and with conventional angiography in 12 patients (12%). Mean tunneled segment length and depth at CT (n = 150) were 24.3 mm +/- 10.0 and 2.6 mm +/- 0.8, respectively. Systolic compression in the 12 patients was 31.3% +/- 11.0 at CT and 28.2% +/- 10.5 at conventional angiography (r = 0.72, P < .001). With CT, a significant correlation was not found between systolic compression and length (r = 0.16, P = .25, n = 150) but was found with depth (r = 0.65, P < .01, n = 150) of the tunneled segment. In 14 patients in whom MB was found at CT but not at conventional angiography, length, depth, and systolic compression were significantly lower than in patients in whom both modalities depicted the anomaly (P < .001, P < .01, and P < .001, respectively). CONCLUSION: The depiction rate of MB is greater with 64-section CT coronary angiography than with conventional coronary angiography. The degree of systolic compression of MB significantly correlates with tunneled segment depth but not length.

Levoatrial cardinal vein in mitral atresia and closed foramen ovale: prenatal diagnosis and perinatal management

A levoatrial cardinal vein is a rare cardiovascular anomaly that may be present in malformed hearts with severe left heart obstruction and restrictive interatrial communication. We report the prenatal diagnosis at 23 weeks of a fetus with mitral atresia, double-outlet right ventricle, premature closure of the foramen ovale and a levoatrial cardinal vein draining into the innominate vein. In a prior examination performed elsewhere the levoatrial cardinal vein had been interpreted as an aortic arch perfused retrogradely, and hypoplastic left heart syndrome with aortic atresia had been diagnosed. Prenatal management, induction at 38 weeks and postnatal examinations and treatment are reported. To the best of our knowledge, this is the first reported prenatal diagnosis of this embryological vessel, presenting a potential pitfall for prenatal echocardiography.

Development of system separation strategy using synchrophasor data

In the current market system, power systems are operated at higher loads for economic reasons. Power system stability becomes a genuine concern in such operating conditions. In case of failure of any larger component, the system may become stressed. These events may start cascading failures, which may lead to blackouts. One of the main reasons of the major recorded blackout events has been the unavailability of system-wide information. Synchrophasor technology has the capability to provide system-wide real time information. Phasor Measurement Units (PMUs) are the basic building block of this technology, which provide the Global Positioning System (GPS) time-stamped voltage and current phasor values along with the frequency. It is being assumed that synchrophasor data of all the buses is available and thus the whole system is fully observable. This information can be used to initiate islanding or system separation to avoid blackouts. A system separation strategy using synchrophasor data has been developed to answer the three main aspects of system separation: (1) When to separate: One class support machines (OC-SVM) is primarily used for the anomaly detection. Here OC-SVM was used to detect wide area instability. OC-SVM has been tested on different stable and unstable cases and it is found that OC-SVM has the capability to detect the wide area instability and thus is capable to answer the question of “when the system should be separated”. (2) Where to separate: The agglomerative clustering technique was used to find the groups of coherent buses. The lines connecting different groups of coherent buses form the separation surface. The rate of change of the bus voltage phase angles has been used as the input to this technique. This technique has the potential to exactly identify the lines to be tripped for the system separation. (3) What to do after separation: Load shedding was performed approximately equal to the sum of power flows along the candidate system separation lines should be initiated before tripping these lines. Therefore it is recommended that load shedding should be initiated before tripping the lines for system separation.

A STUDY OF SO2 EMISSIONS AND GROUND SURFACE DISPLACEMENTS AT LASTARRIA VOLCANO, ANTOFAGASTA REGION, NORTHERN CHILE

Lastarria volcano (Chile) is located at the North-West margin of the `Lazufre' ground inflation signal (37x45 km²), constantly uplifting at a rate of ~2.5 cm/year since 1996 (Pritchard and Simons 2002; Froger et al. 2007). The Lastarria volcano has the double interest to be superimposed on a second, smaller-scale inflation signal and to be the only degassing area of the Lazufre signal. In this project, we compared daily SO2 burdens recorded by AURA's OMI mission for 2005-2010 with Ground Surface Displacements (GSD) calculated from the Advanced Synthetic Aperture Radar (ASAR) images for 2003-2010. We found a constant maximum displacement rate of 2.44 cm/year for the period 2003-2007 and 0.80- 0.95 cm/year for the period 2007-2010. Total SO2 emitted is 67.0 kT for the period 2005-2010, but detection of weak SO2 degassing signals in the Andes remains challenging owing to increased noise in the South Atlantic radiation Anomaly region.

EXPLORATION OF THE MTSAT2 SATELLITE CAPABILITIES FOR REAL TIME DETECTION AND CHARACTERIZATION OF VOLCANIC EMISSIONS

In this report, we attempt to define the capabilities of the infrared satellite remote sensor, Multifunctional Transport Satellite-2 (MTSAT-2) (i.e. a geosynchronous instrument), in characterizing volcanic eruptive behavior in the highly active region of Indonesia. Sulfur dioxide data from NASA's Ozone Monitoring Instrument (OMI) (i.e. a polar orbiting instrument) are presented here for validation of the processes interpreted using the thermal infrared datasets. Data provided from two case studies are analyzed specifically for eruptive products producing large thermal anomalies (i.e. lava flows, lava domes, etc.), volcanic ash and SO2 clouds; three distinctly characteristic and abundant volcanic emissions. Two primary methods used for detection of heat signatures are used and compared in this report including, single-channel thermal radiance (4-µm) and the normalized thermal index (NTI) algorithm. For automated purposes, fixed thresholds must be determined for these methods. A base minimum detection limit (MDL) for single-channel thermal radiance of 2.30E+05 Wm- 2sr-1m-1 and -0.925 for NTI generate false alarm rates of 35.78% and 34.16%, respectively. A spatial comparison method, developed here specifically for use in Indonesia and used as a second parameter for detection, is implemented to address the high false alarm rate. For the single-channel thermal radiance method, the utilization of the spatial comparison method eliminated 100% of the false alarms while maintaining every true anomaly. The NTI algorithm showed similar results with only 2 false alarms remaining. No definitive difference is observed between the two thermal detection methods for automated use; however, the single-channel thermal radiance method coupled with the SO2 mass abundance data can be used to interpret volcanic processes including the identification of lava dome activity at Sinabung as well as the mechanism for the dome emplacement (i.e. endogenous or exogenous). Only one technique, the brightness temperature difference (BTD) method, is used for the detection of ash. Trends of ash area, water/ice area, and their respective concentrations yield interpretations of increased ice formation, aggregation, and sedimentation processes that only a high-temporal resolution instrument like the MTSAT-2 can analyze. A conceptual model of a secondary zone of aggregation occurring in the migrating Kelut ash cloud, which decreases the distal fine-ash component and hazards to flight paths, is presented in this report. Unfortunately, SO2 data was unable to definitively reinforce the concept of a secondary zone of aggregation due to the lack of a sufficient temporal resolution. However, a detailed study of the Kelut SO2 cloud is used to determine that there was no climatic impacts generated from this eruption due to the atmospheric residence times and e-folding rate of ~14 days for the SO2. This report applies the complementary assets offered by utilizing a high-temporal and a high-spatial resolution satellite, and it demonstrates that these two instruments can provide unparalleled observations of dynamic volcanic processes.

The umbilical cord in Cantrell: Pentalogy or Hexalogy?

Objective: Pentalogy of Cantrell (PC) is a rare congenital defect associated with five midline anomalies. The type of cardiac malformation and the size of the abdominal wall defect is often responsible for the high mortality. Of interest, the embryonic period in which PC develops is similar to that of the umbilical cord’s (UC) formation. The aim of the following study was to investigate the relationship between UC anomalies and PC. Methods: Charts of four cases with PC from 2002–08 were retrospectively reviewed for associated UC anomalies. UC anomalies were defined as single umbilical artery (SUA), short cord (during 1st trimester less than CRL or less than 30cm at term) or atypical UC coiling pattern. Results: We identified four cases: 3 singletons and one monochorionic diamniotic twin pregnancy with TRAP sequence. All cases showed a normal karyotype. All but one demonstrated the classical pulsatile omphalocele with ectopia cordis and all others anomalies of PC. One case was characterized by a major cranial omphalocele without ectopia cordis and no UC anomaly. This fetus was delivered by Cesarean at term and successfully operated on d1. In all other cases the parents requested ToP. Among the three cases with ectopia cordis, two had a short UC with SUA and one a short three-vessel cord; all these three UC were markedly uncoiled. Conclusions: Our data suggest a strong association between Cantrell and the development of the UC, in particular in cases with ectopia cordis. One might speculate that hemodynamic alterations of the feto-placental blood flow because of the cardiac malformation or structural changes at the umbilical ring (omphalocele) influence the development of the UC. More observations are needed to decide if Cantrell is a ‘‘hexalogy’’ instead of pentalogy.

Late Holocene summer temperatures in the central Andes reconstructed from the sediments of high-elevatin Laguna Chepical, Chile (32° S)

High-resolution reconstructions of climate variability that cover the past millennia are necessary to improve the understanding of natural and anthropogenic climate change across the globe. Although numerous records are available for the mid- and high-latitudes of the Northern Hemisphere, global assessments are still compromised by the scarcity of data from the Southern Hemisphere. This is particularly the case for the tropical and subtropical areas. In addition, high elevation sites in the South American Andes may provide insight into the vertical structure of climate change in the mid-troposphere. This study presents a 3000 yr-long austral summer (November to February) temperature reconstruction derived from the 210Pb- and 14C-dated organic sediments of Laguna Chepical (32°16' S, 70°30' W, 3050 m a.s.l.), a high-elevation glacial lake in the subtropical Andes of central Chile. Scanning reflectance spectroscopy in the visible light range provided the spectral index R570/R630, which reflects the clay mineral content in lake sediments. For the calibration period (AD 1901–2006), the R570/R630 data were regressed against monthly meteorological reanalysis data, showing that this proxy was strongly and significantly correlated with mean summer (NDJF) temperatures (R3 yr = −0.63, padj = 0.01). This calibration model was used to make a quantitative temperature reconstruction back to 1000 BC. The reconstruction (with a model error RMSEPboot of 0.33 °C) shows that the warmest decades of the past 3000 yr occurred during the calibration period. The 19th century (end of the Little Ice Age (LIA)) was cool. The prominent warmth reconstructed for the 18th century, which was also observed in other records from this area, seems systematic for subtropical and southern South America but remains difficult to explain. Except for this warm period, the LIA was generally characterized by cool summers. Back to AD 1400, the results from this study compare remarkably well to low altitude records from the Chilean Central Valley and southern South America. However, the reconstruction from Laguna Chepical does not show a warm Medieval Climate Anomaly during the 12–13th century, which is consistent with records from tropical South America. The Chepical record also indicates substantial cooling prior to 800 BC. This coincides with well-known regional as well as global glacier advances which have been attributed to a grand solar minimum. This study thus provides insight into the climatic drivers and temperature patterns in a region for which currently very few data are available. It also shows that since ca. AD 1400, long-term temperature patterns were generally similar at low and high altitudes in central Chile.

Cold surge episodes over southeastern Brazil - a potential vorticity perspective

Most intense cold surges and associated frost events in southern and southeastern Brazil are characterized by a large amplitude trough over South America extending toward tropical latitudes and a ridge to the west of it over the Pacific Ocean. In this study, potential vorticity (PV) streamers serve to examine the flow condition leading to cold surges. Case studies suggest that several PV anomalies are related to cold surge episodes: (1) the potential vorticity unit (2-PVU) isoline upstream of South America becomes progressively more distorted prior and during the cold surge episode, indicating a flow situation which is conducive for Rossby wave breaking and hence a flow which strongly deviates from zonality; (2) the initial stage of a cold surge episode is characterized by a northward bulging of high-PV air to the east of the Andes, resulting in a PV streamer whose northern end reaches Uruguay and southeastern Brazil; the strong PV gradient on its western flank constitutes a flow configuration that induces and maintains the transport of sub-Antarctic air toward the subtropics; (3) a distinct negative PV anomaly, a blocking, originates over the eastern South Pacific, upstream of the South America sector. A composite analysis of 27 cold surges is performed for stratospheric PV streamer frequency on several isentropic surfaces. It reveals that equatorward wave breaking over South America and the western South Atlantic represents an important potential component of the dynamics of intense cold surges. The indications are most pronounced around the isentropic levels of 320 K and immediately before the day with largest temperature drops over subtropical Brazil.

The 1945-1949 droughts in Switzerland

This paper studies the representation of a drought period that affected Central Europe from 1945 to 1949 in the “Twentieth Century Reanalysis” (20CR). We analysed temperature and precipitation fields in 20CR and compared them to other data products. From the monthly precipitation rate at a 20CR grid point in the Swiss Plateau, the Standardised Precipitation Index over six months (SPI6) was calculated and compared with the corresponding index calculated from station data. For additional analyses, 20CR soil moisture, run off, and evaporation data were used. 20CR well reproduces the temperature and precipitation anomalies over Central Europe during this period, although during 1947, the precipitation anomaly is shifted to the east as compared to observations. With respect to the SPI6 index, the agreement between 20CR and station data is good except again for 1947 (conversely, drought was overestimated in 20CR for 1945 and 1949). Low SPI values in 20CR are accompanied by negative soil moisture anomalies and a negative water balance. Thus, apart from the shift in the spatial drought pattern in 1947, the drought is depicted in a realistic way in 20CR.