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High-resolution computed micro-tomography is an important area of science, which correlates well with several experimental methodologies and serves as a basis for advanced computational physics studies, in which high-resolution images are used as input to different scientific simulation models. The dataset presented herein includes (raw) grayscale images obtained using the Bruker Skyscan 1272 X-Ray tomograph; filtered images acquired through contrast enhancement and noise reduction filters; and segmented images obtained by using the IsoData segmentation method. All images have a resolution of 2.25 µm (isometric voxels) and size of 10003 voxels.

Summary Background People with mental disabilities are more likely to become subject to police violence than the general population, as shown by a review of the literature. Methodology A media search was performed for fatal confrontations between Israeli police or security officers and people with mental disabilities, in the years 2019–2020. Discussion Four lethal incidents and one severe but non-lethal incidents draw attention to the intersection of identities of the victims, who not only had disabilities but also belonged to minority groups. Systematic documentation and investigation of cases is lacking. Conclusion National authorities are requested to be transparent in their reporting and investigate cases of police violence. Health professionals are encouraged to document any incidents of violence by law enforcement personnel in medical files, in case of injury, with ICD-10 code Y35.

ObjectiveThere is cross-center variability with regard to timing repair of non–ductal-dependent tetralogy of Fallot (TOF). We hypothesized that earlier repair in the neonatal period is associated with increased mortality and morbidity.MethodsThis was a retrospective analysis of the Pediatric Health Information System of tetralogy of Fallot patients undergoing complete repair from 2004 through 2010 between the ages of 1 day to younger than 19 years. Patients with pulmonary valve atresia, those who received prostaglandin during hospital admission, and those who underwent prior shunt palliation were excluded.ResultsA total of 4698 patients met our inclusion criteria, of whom 202 were younger than 30 days old (group A), 861 were 31 to 90 days old (group B), 1796 were 91 to 180 days old (group C), and 1839 were older than 180 days (group D). In-hospital mortality, intensive care unit length of stay, and total hospital length of stay were significantly higher in group A. Patients in group A had a significantly increased postoperative requirement for mechanical ventilation, intravenous blood pressure support, medical diuresis, extracorporeal membrane oxygenation, gastrostomy tube insertion, heart catheterization, and surgical revision. Significant institutional variability was noted for timing of TOF complete repair, with one third of the centers performing 75% of the repairs at younger than 30 days old. The institutional approach to timing TOF complete repair showed no relation to surgical volume.ConclusionsAcross all centers analyzed, primary neonatal elective TOF repair (

A study was conducted to evaluate the effects of pre partum (PRE) and post partum (POST) dietary energy and nutrient supply (E) and their interactions on feed intake, performance and energy status in dairy cows of three breeds. In this experiment, the effects of three energy and nutrient supply levels (low (L), medium (M), high (H)), both pre-calving and post-calving, were investigated, using a 3×3 factorial arrangement of treatments. In both phases (84 days pre- and 105 days post-calving) E levels applied to a total of 81 multiparous cows of breeds Simmental (SI), Brown Swiss (BS) and Holstein–Friesian (HF; n=27 for each breed), were 75%, 100% and 125% of recommendations of the German Society of Nutrition Physiology (GfE). Dry matter intake (DMI) was restricted, if energy intake exceeded target values. Pre partum DMI and energy intake were different as designed, liveweight and body condition score (BCS) of SI cows were higher, but EB was lower, compared to BS and HF cows. Milk yield and composition were influenced by all three main experimental factors (EPRE, EPOST, breed). Energy-corrected milk yield was 25.6, 28.6 and 30.1 kg/day for LPRE, MPRE and HPRE as well as 21.5, 30.1 and 32.6 kg/day for LPOST, MPOST and HPOST, respectively. Numerically, only for milk protein content the interactions EPRE×EPOST and EPRE×breed reached significance. Impact of energy supply pre-calving was more pronounced when cows had lower energy supply post-calving and vice versa. On the other hand, milk yield response of cows to energy supply above requirements was greater for cows that were fed on a low energy level pre partum. Impact of energy level pre partum was higher for HF cows, showing that their milk production relies to a greater extent on mobilization of body reserves. Increasing energy supply pre partum led to a more negative energy balance post partum, mainly by increasing milk yield and content, whereas feed intake was slightly reduced. Increasing energy supply post partum enhanced milk yield as well as milk protein and lactose content. Calculated energy balance corresponded well with liveweight and BCS change. Response of milk yield to increasing energy supply followed the principle of diminishing returns, since energy was increasingly partitioned to body retention. Increasing energy supply pre partum enhances milk yield and content post partum, but exacerbates negative energy balance and its consequences.

The present study created a basis for development of a fast, non-destructive method to measure ascorbic acid content during various growth stages of three bell pepper cultivars: ‘Ever Green’, ‘No. 117’ and ‘Celica’. Fruit were tagged at the flowering stage and picked weekly during 9 weeks of growth, until fully ripe. Visible and near-infrared (VIS–NIR) spectra in the range 477–950 nm were obtained in reflectance mode from intact peppers with a USB2000 mini-spectrometer. Short-wave infrared (SWIR) spectra in the range 850–1888 nm were obtained in reflectance mode from the same sampled peppers with a Liga Spectrometer. Fruit flesh samples were cut from the area scanned for spectral measurements, and destructively analyzed for ascorbic acid content. The highest ascorbic acid content was measured in the green variety ‘Ever Green’ (148.1 mg per 100 g). Varieties ‘Ever Green’ and ‘No. 117’ accumulated significantly higher concentrations of ascorbic acid than ‘Celica’, and consistent and significant differences were found between the premature, green and mature stages of all three cultivars. Partial Least-Squares (PLS) regression was used in spectral model development. Comparisons were made between the PLS regression analysis of the reflectance spectra ( R ), its first derivative ( D 1 R ), the log(1/ R ) and its first ( D 1 log(1/ R )) and second derivative ( D 2 log(1/ R )). VIS–NIR and SWIR spectroscopy measurements showed good correlation ( r 2 = 0.76) with changes in ascorbic acid content. The PLS regression models were able to predict ascorbic acid content for all three cultivars, with 15.1–18.9 mg per 100 g cross-validation error (RPD = 2–2.4). The method offers potential for non-destructive detection of changes in ascorbic acid content during growth and maturation of intact bell peppers.

Although oaks (Quercus spp.) have historically dominated much of the forest land in eastern North America, a great deal of fragmentary and sometimes anecdotal evidence suggests that they have been yielding dominance in recent decades to other, typically more shade-tolerant species. Using FIA data, our work formally quantifies the change in oak abundance in the eastern U.S. during the period of 1980–2008. The results indicate that most areas in the eastern U.S. experienced some decline in oak abundance, but the decrease was not universal either geographically or among species. Declines were especially marked in the Central Hardwood Region, which lost oak abundance on 81% its forested area as measured by importance value (IV). Areas with a high oak abundance were more likely to see a reduction in abundance. Among all 25 species analyzed, eight species decreased significantly in IV while two increased. Both the top two most prevalent white oak species (white oak (Quercus alba) and post oak (Quercus stellata)) and red oak species (northern red oak (Quercus rubra) and black oak (Quercus velutina)) had significant decreases in density and IV. Water oak (Quercus nigra) is one of the red oak species that had a near universal increase of its abundance throughout its native range (83% of area). This study provided a comprehensive quantification of the dynamic of oak species in a regional-wide geographic context, which will provoke forest researchers and managers to revisit the oak decline problem by using knowledge from other regions and other species.

Objectives Data regarding atherogenic dyslipidemia and the inflammation profile in youth with type 2 diabetes is limited and the effect of insulin therapy on these variables has not previously been studied in youth. We determined the impact of insulin therapy on lipid and inflammatory markers in youth with poorly controlled type 2 diabetes. Study design In the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) multicenter trial, 285 participants failed to sustain glycemic control on randomized treatment (primary outcome, glycated hemoglobin A1c [HbA1c] at ≥8% for 6 months); 363 maintained glycemic control (never reached primary outcome). Statins were used for a low-density lipoprotein cholesterol of ≥130 mg/dL. Upon reaching the primary outcome, insulin was started. Changes in lipids and inflammatory markers (slopes over time) were examined. Results Progression of dyslipidemia was related to glycemic control. In those with the primary outcome, insulin therapy impacted HbA1c modestly, and dampened the increase in total cholesterol, low-density lipoprotein cholesterol, and total apolipoprotein B, although statin use increased from 8.6% to 22% year after the primary outcome. The increase in triglycerides and plasma nonesterified fatty acids stabilized after insulin was started, independent of HbA1c. There was an increase in high-sensitivity C-reactive protein that continued after insulin initiation, related to HbA1c and percent overweight. Conclusions Worsening dyslipidemia and inflammation over time raise concern regarding premature development of atherosclerosis in youth with type 2 diabetes. Insulin therapy has a limited benefit in the absence of glycemic control. Strategies to achieve better glycemic control are needed. Trial registration ClinicalTrials.gov : NCT00081328 .

The formation of (4R)-4-carbamoyl-4-[(4R)-3-O-benzyl-1,2-O-isopropylidene-beta-l-threofuranos-4-C-yl]-oxazolidin-2-one instead of expected imidazolidin-2,4-dione (hydantoin) derivative from 5-amino-5-cyano-5-deoxy-3-O-benzyl-1,2-O-isopropylidene-alpha-d-glucofuranose or 3-O-benzyl-1,2-O-isopropylidene-alpha-d-xylo-hexofuranos-5-ulose under Bucherer-Bergs reaction conditions is reported. Single crystal X-ray diffraction data revealed that (3)T(4) is the prefered conformation for the furanose ring, while E(2) and (2)T(1) conformations are adopted by the 1,3-dioxolane and 2-oxazolidinone five-membered rings, respectively.

Paleosol macromorphology, petrography and stable isotope geochemistry of carbonate nodules from Permo–Triassic (P–T) boundary strata of the central Karoo basin, South Africa are presented in order to evaluate their utility as geochemical archives of Permian–Triassic paleoatmospheric chemistry and their potential to provide a terrestrial carbon isotope chemostratigraphy for correlation with contemporaneous global marine δ 13 C records. Paleosol morphologies across P–T boundary strata of the central Karoo basin indicate the region was a poorly drained, seasonally to continuously flooded bottomland. Radiaxial calcite, microspar and micrite microtextures are observed in the calcite nodules associated with P–T paleosol profiles. Micritic calcite is typical of soil carbonate that forms in well-drained soils characterized by open-system gaseous diffusion between the soil and global atmosphere, whereas more coarsely crystalline textures and radiaxial calcite are more typical of crystallization in phreatic environments with limited gaseous diffusion between the soil and global atmosphere. In this regard, only those nodules composed of micritic calcite can be considered as a potentially reliable source of proxy information for paleoatmospheric δ 13 C values across the P–T boundary. The δ 13 C values of all carbonate nodules from two overlapping measured sections near Carlton Heights, South Africa range from − 24.4‰ to − 1.8‰, whereas micritic calcite nodule δ 13 C values range from − 7.0‰ to − 21.3‰. Comparison of calcite δ 13 C values with penecontemporaneous organic matter δ 13 C values indicate that calcite δ 13 C values δ 13 C values. Rather, these more negative carbonate nodule δ 13 C values likely reflect calcite crystallization under poorly drained, swampy conditions characterized by a semi-closed chemical system that evolved independently of Earth's troposphere. Therefore, previously reported negative carbon isotope shift(s) measured from carbonate nodules in the Karoo basin P–T strata do not provide a record of atmospheric δ 13 C, and probably do not provide a viable carbon isotope stratigraphy that can be realistically correlated with global P–T marine carbon isotope stratigraphies.

FoxD3 is a forkhead-related transcriptional regulator that is essential for multiple developmental processes in the vertebrate embryo, including neural crest development and maintenance of mammalian stem cell lineages. Recent results demonstrate a requirement for FoxD3 in Xenopus mesodermal development. In the gastrula, FoxD3 functions as a transcriptional repressor in the Spemann organizer to maintain the expression of Nodal-related members of the transforming growth factor-beta superfamily that induce dorsal mesoderm formation. Here we report that the function of FoxD3 in mesoderm induction is dependent on the recruitment of transcriptional corepressors of the TLE/Groucho family. Structure-function analyses indicate that the transcriptional repression and mesoderm induction activities of FoxD3 are dependent on a C-terminal domain, as well as specific DNA-binding activity conferred by the forkhead domain. The C-terminal domain contains a heptapeptide similar to the eh1/GEH Groucho interaction motif. Deletion and point mutagenesis demonstrated that the FoxD3 eh1/GEH motif is required for both repression of transcription and induction of mesoderm, as well as the direct physical interaction of FoxD3 and Grg4 (Groucho-related gene-4). Consistent with a functional interaction of FoxD3 and Grg4, the transcriptional repression activity of FoxD3 is enhanced by Grg4, and reduced by Grg5, a dominant inhibitory Groucho protein. The results indicate that FoxD3 recruitment of Groucho corepressors is essential for the transcriptional repression of target genes and induction of mesoderm in Xenopus.

The most severe mass extinction of marine species and terrestrial vertebrates and plants is associated with the Permian–Triassic boundary (∼251 Ma). The extinction interval is also marked by the disappearance of most Late Permian gymnosperm palynomorphs at a layer containing solely the abundant remains of fungi. This ‘fungal spike’ apparently represents widespread devastation of arboreous vegetation. Stratigraphic and palynological study of the Carlton Heights section in the southern Karoo Basin of South Africa revealed a 1-m-thick fungal spike zone that occurs simultaneously with the last appearance of typically Late Permian gymnosperm pollen. The plant extinction and fungal spike zone are found above the last occurrence of Late Permian mammal-like reptiles of the Dicynodont Zone at other Karoo sections. Using the fungal event as a time line in marine and non-marine sections allows placement of the marine extinctions and the extinction of terrestrial plants and reptiles within a brief crisis interval of less than about 40 000 years at the end of the Permian.

Theoretical and structural studies followed by the directed synthesis and in vitro biological tests lead us to novel noncovalent thrombin pseudopeptide inhibitors. We have incorporated an azapeptide scaffold into the central part of the classical tripeptide d -Phe-Pro-Arg inhibitor structure thus eliminating one stereogenic center from the molecule. A series of compounds has been designed to optimize the occupancy of the S2 pocket of thrombin. Increased hydrophobicity at P2 provides an enhanced fit into this active site S2 pocket. In the present paper, we also report on the structure of these inhibitors in solution and conformational analysis of inhibitors in the active site in order to asses the consequences of the replacement of the central α-CH by a nitrogen functionality. In vitro biological testing of the designed inhibitors shows that elimination of R, S stereoisomerism and restriction of conformational freedom influences the binding of inhibitors in a favorable fashion.

Permanent grassland of a typical Alpine region in Austria (Styria, 700 m above sea level, 1100 mm precipitation) was cut either 2, 3 or 4 times per year, conserved as barn-dried hay and fed to dairy cows at three concentrate levels [zero, concentrate according to requirements or 25% of dry matter (DM) intake concentrate]. Fertilisation levels were 32 m 3 slurry with or without 100 kg N ha −1 mineral N. Because of lower DM yield (8.65, 8.05, 6.51 t ha −1 ) and higher forage intake (10.4, 13.2 and 15.3 kg DM) the potential stocking rate decreased with increasing cutting frequency. Milk yield and N excretion per cow increased with increasing cutting frequency. When milk yield and N excretion were related to the forage area there was only a small influence of cutting frequency at the low level of concentrate. When the forage was supplemented with concentrate according to requirements, both milk yield and N excretion per ha decreased with increasing cutting frequency. Additional fertilisation of 100 kg mineral N increased the amount of slurry from 37.5 to 41.4 m 3 ha −1 forage and excretion of N from 149 to 160 kg ha −1 forage.

The trial was designed to assess the safety, pharmacodynamics and effects on reperfusion of the platelet glycoprotein (GP) IIb/IIIa inhibitor lamifiban when given with thrombolysis to patients with ST segment elevation acute myocardial infarction.Studies of fibrinolytic agents in acute myocardial infarction have demonstrated a direct relationship between early complete reperfusion and survival. Blockade of the platelet GP IIb/IIIa receptor complex inhibits platelet aggregation and may speed reperfusion when given in conjunction with thrombolysis to patients with acute myocardial infarction.Patients with ST segment elevation presenting within 12 h of symptom onset who were treated with either tissue-plasminogen activator or streptokinase were enrolled in this three-part Phase II dose exploration study. In Part A, all patients received the GP IIb/IIIa inhibitor lamifiban in an open-label, dose escalation scheme. Parts B and C were a randomized, double-blind comparison of a bolus plus 24-h infusion of lamifiban versus placebo with patients randomized in a 2:1 ratio. The goal was to identify a dose(s) of lamifiban that provided85% adenosine diphosphate (ADP)-induced platelet aggregation inhibition. A composite of angiographic, continuous electrocardiographic and clinical markers of reperfusion was the primary efficacy end point, and bleeding was the primary safety end point.Platelet aggregation was inhibited by lamifiban in a dose-dependent manner with the highest doses exceeding 85% ADP-induced platelet aggregation inhibition. There was more bleeding associated with lamifiban (transfusions in 16.1% lamifiban-treated vs. 10.3% placebo-treated patients). Lamifiban induced more rapid reperfusion as measured by all continuous electrocardiographic (ECG) parameters.Lamifiban given with thrombolytic therapy appears to be associated with more rapid and complete reperfusion than placebo. As expected in this small sample, there were no obvious clinical benefits to lamifiban over placebo. Reconciliation of ECG monitoring with clinical outcomes will require a larger, adequately powered clinical trial.

The free surfaces of liquid water, formamide and ethylene glycol are prepared as a microjet in a high vacuum where they are studied by UV photoelectron spectroscopy with He I ( hν =21.22 eV) photons. The low vapour pressure liquid formamide UPS spectrum, which has already been reported, serves as an independent test of the accuracy of the present method. In agreement with a detailed investigation of experimental offset potentials, a measurement of the electrical current transported by the jet provides a highly accurate absolute calibration of the photoelectron spectra with respect to the vacuum zero energy level. The corrected spectra show several ionization bands which are shifted by approximately 1 eV to lower ionization energies with respect to the related gas phase molecular orbitals as a result of the electronic relaxation energy contribution to the molecular solvation forces.

We investigate the morphological evolution during the growth of strained Ge x Si 1 − x layers from ln solution (5 ⩽ x ⩽ 15%). Surface ripples develop due to elastic stress relaxation. These ripples self-organize in a way that a defined wavelength and a two-dimensional pattern aligned along (1 0 0) directions develops. During further growth, the ripples transform into pseudomorphic islands and island growth proceeds in vertical direction at constant island width. The ripple wavelength and the island size are controlled by the germanium content and verify energetical predictions. Further, the theoretical expectation is corroborated that island development occurs even at low misfits when deposition is controlled by energetics.

A cDNA encoding a calmodulin-stimulated 3',5'-cyclic nucleotide phosphodiesterase (PDE) was isolated from a human brain cDNA library. The cDNA, designated HSPDE1B1, encoded a protein of 536 amino acids that shared 96% sequence identity with the bovine "63 kDa" calmodulin-stimulated PDE. The recombinant protein had cyclic nucleotide phosphodiesterase activity that was stimulated approximately 2-fold by Ca2+/calmodulin and preferred cGMP as substrate. In addition, the enzymatic activity of HSPDE1B1 was inhibited by phosphodiesterase inhibitors with potencies similar to that displayed toward the bovine PDE1 enzymes: IBMX approximately equal to 8-methoxymethyl-IBMXvinpocetine approximately equal to zaprinastcilostamiderolipram. HSPDE1B1 mRNA was found predominantly in the brain. Lower mRNA levels were found in heart and skeletal muscle. In situ hybridisation of brain revealed expression of HSPDE1B1 predominately in neuronal cells of the cerebellum, hippocampus and caudate. The HSPDE1B1 gene was mapped to human chromosome 12. A partial genomic sequence of HSPDE1B1 was isolated and shown to contain two splice junctions that are conserved in the rat PDE4 and the Drosophila dunce genes.

We grew epitaxial Si layers from solution (liquid phase epitaxy) on polycrystalline Si sheet material and compared the surface morphology and crystalline perfection of these layers with those of layers grown on cast Si material. Furthermore, using epitaxial layers on cast Si, we studied the correlation between layer thickness, growth time and cooling rate. In the discussion of the measured dependences we make use of simplified calculations of the diffusion coefficient of Si in In solutions and demonstrate the efficiency of Si layer deposition by liquid phase epitaxy.

Thin silicon films, solution-grown on cast silicon wafers, are examined as an example of liquid phase epitaxy of silicon on a polycrystalline seed layer. We investigate the structural and electrical properties of grain boundaries in the epilayers by transmission electron microscopy and electron-beam-induced current measurements. We find that growth close to thermodynamic equilibrium leads to low electrical activity of defects and to a low-energy geometry of grain boundaries. Layers grown with different growth rates show no difference in electrical activity. Trenches at grain boundary sites are typical surface features of the epilayers. An increased growth rate leads to a reduction in trench depth, which is an advantage for the contact metallization of solar cells.

In order to study the influence of the process parameters during growth of thin Si layers on polycrystalline Si substrates we carried out liquid phase epitaxy under different experimental conditions. We investigated the dependence of layer thickness and morphology of grain boundaries on these parameters. We also studied the incorporation of dopants (Ga; As) in the Si layers.

Stratotypes defining the stages of the Early Triassic (Griesbachian, Dienerian, Smithian and Spathian) are located on Ellesmere and Axel Heiberg islands in the northern Canadian Arctic. Ammonite-rich horizons are within a clastic outer shelf-to-slope facies of thick progradational wedges of mudstones and siltstones. Three sections were sampled for magnetostratigraphy and interpreted for transgressive and regressive pulses of sedimentation. Using the ammonite zonation as a guide, the transgressive-regressive cycles and magnetostratigraphies have been correlated among the sections and to the published Triassic sequence stratigraphy time scale, thus enabling definition of the magnetic polarity pattern for the upper Griesbachian to Smithian stages in multiple sections. The magnetic polarity and associated sequence stratigraphy pattern for the lower Griesbachian and for the Spathian were derived from single sections. The Griesbachian and Dienerian stages each have two pairs of normal- and reversed-polarity chrons; the Smithian is predominantly of normal polarity, and the Spathian is predominantly of reversed polarity. This magnetic polarity time scale may help to resolve age correlations of North American redbed facies and to define the Permian-Triassic boundary. After correction for variable structural orientations, the mean directions of magnetization from the three sites converge at 296° declination, 57° inclination (k = 60,α95 = 16.5°; equivalent pole = 41°N, 161°E; paleolatitude = 38°N), which is consistent with the pole derived from nearby Early Permian volcanics and supports a postulated post-Early Triassic, pre-Tertiary counterclockwise rotation of this region with respect to cratonic North America.

A magnetic polarity pattern has been constructed for the Early Callovian through Middle Oxfordian stages of the Jurassic from several ammonite-rich magnetostratigraphy sections within the Krakow-Czestochowa-Wielun region of southern Poland. These overlapping sections encompass portions of every ammonite from the late-Early Callovian through late-Middle Oxfordian; however, the presence of several hiatuses and condensed intervals within the shallow-marine to pelagic sediments preclude reliable identification of the complete polarity pattern. The mean Callovian-Oxfordian pole from these sites is at 74.3°N, 200.3°E (α95 = 4.7°). The Callovian through Early Oxfordian is dominated by reversed polarity with a minimum of five normal-polarity zones. The early-Middle Oxfordian is predominantly of normal polarity, and the late-Middle Oxfordian is characterized by reversed polarity, with several relatively brief normal-polarity episodes. The Callovian and Oxfordian stages appear to average a minimum of two magnetic polarity reversals per million years. This reversal frequency is similar to the average Tertiary record, but is less than the reported spacing of Callovian and Oxfordian magnetic anomalies in the Pacific.

Extracorporeal membrane oxygenation (ECMO) has been used for 20 years in neonates and children with cardiac and respiratory failure. The number of neonates treated with ECMO has increased exponentially, but the number of older children treated is small. The selection and exclusion criteria for pediatric ECMO are poorly defined, and the results vary because of variable selection criteria and institutional experience with the technique. In order to help define the role of pediatric ECMO, we reviewed our experience in nonneonatal pediatric respiratory failure. We have treated 22 patients ranging in age from 1 to 105 months and ranging in weight from 3 to 35 kg. Eighteen patients met the criteria for adult respiratory distress syndrome, two had respiratory scyncytial virus pneumonia, and one had severe barotrauma complicating the management of reactive airway disease. All patients were considered by the referring institutions and by us to be failing conventional management as evidenced by hypoxia, hypercarbia, excessive ventilatory pressures, or progressive barotrauma. All were considered likely to die with continued conventional management. Sixteen of the 22 patients had complications (73%), but half of the last 10 patients had no complications. Hemorrhagic complications occurred in 12 patients. Mechanical complications included membrane failure, raceway rupture, pump malfunction, and improper cannula positioning. Other complications included culture-proven infection and renal failure. Eleven of the 22 patients survived (50%); nine of the last 12 survived (75%). These results suggest that ECMO may be a useful technique in selected pediatric patients with respiratory failure. Survival and complication rates improve as experience with the technique increases.

Endocrinologists have conducted many studies on the effects of gonadal steroids and gonadotropin releasing hormone (GnRH) agonists with testosterone (T) as potential male contraceptives. Results of most of the studies show that treatments suppressed sperm counts but in >60% of subjects the levels did not fall to azoospermic levels. Research indicates that steroid treatments are more likely to achieve azoospermia in men from Indonesia and China than in Caucasian men. Research for stronger inhibitors of gonadotropin secretion began during the 1980s with GnRH antagonist analogs. Endocrinologists in California injected 8 men with 7.5 mg/day of the potent GnRH antagonist (Nal-Glu GnRH) and testosterone enanthate (TE2) every 2 weeks starting with the 2nd week for 16 weeks. 7 men experienced azoospermia within 6-10 weeks and LH levels fell below detectable levels. FSH also fell. TE2 levels fell to castrate levels by 2 weeks but returned to normal after the physicians administered TE2. TE2 administration preserved libido and sexual potency. LH suppression was not complete in the other man who withdrew during the 14th week because of considerable local swelling at the Nal-Glu injection site. At week 14 his sperm count measured 7 million/cc (42 million/cc during control). After treatment sperm counts and hormone levels of the 7 men reverted back to normal. These findings were better than other studies on Caucasians in which physicians administered only a high dose of T or GnRH agonists with T. These data and another studys data indicate that reversible azoospermia can occur in almost all men. Additional research is needed to improve the strength of GnRH antagonists which will result in lower costs and less complex T depot formulations. Current studies are examining whether severe oligospermia is sufficient to prevent pregnancy.

This study evaluated the influences of carprofen and the experience of the surgeon on post-castration pain in lambs and young sheep castrated in the field. A total of 201, 1–6-week-old lambs with a mean body mass of 11.0 ± 2.4 kg (mean ± SD) were castrated after local application of 4 mL lidocaine (2%). Preoperatively lambs were given either 20 mg carprofen SC or an equal volume of saline in a randomized order. A further 34 sheep, aged 6 months, with a mean body mass of 36.0 ± 4.5 kg were castrated after local application of 7 mL lidocaine (2%). Preoperatively sheep received 2 mg kg−1 carprofen SC or an equal volume of saline in a randomized order. Lidocaine was injected SC in front of, behind and into each spermatic cord. All surgery was performed using the same Burdizzo clamp (jaw 45 mm wide, handles 225 mm) either by students or experienced veterinary surgeons. Pain was assessed preoperatively and at 24, 48 and 72 hours after castration by two independent observers unaware of the treatment group. Observers scored pain using a visual analog scale (100 mm) after applying gentle pressure onto the scrotal region (Thornton & Waterman-Pearson 1999). Swelling of the scrotal region was scored as ‘severe’, ‘present but not severe’ and ‘not present’. The VAS scores were compared using a Mann–Whitney test, p 0.48) at any of the three assessment times. However, the number of lambs with severe or present swelling of the scrotal region was significantly lower in those receiving carprofen (8% versus 18%, p = 0.028). Lambs castrated by students showed significantly higher pain scores (23% versus 13%, p

Introduction Les hemangiomes capillaires sont des tumeurs vasculaires benignes de localisation retinienne ou papillaire. Ils surviennent de maniere sporadique ou peuvent entrer dans le cadre d’un syndrome de Von Hippel-Lindau. Ils peuvent etre responsables d’une baisse d’acuite visuelle en cas d’œdeme retinien ou d’hemorragies. Nous decrivons 3 patients presentant un angiome capillaire traites par phototherapie dynamique a la verteporfine. Materiels et Methodes Les cas de 3 patients presentant un angiome capillaire sont analyses. L’aspect du fond d’œil et de l’angiofluorographie sont etudies. Observation Le premier cas est celui d’une fille de 13 ans presentant un angiome capillaire peripherique associe a une retinopathie pigmentaire. Elle presente une baisse d’acuite visuelle a 4/10 P4 en raison d’un œdeme maculaire. Un traitement par phototherapie dynamique de la lesion est associe a une injection peri-oculaire de triamcinolone pour l’œdeme maculaire. Le deuxieme cas est celui d’un homme de 52 ans presentant un angiome capillaire prepapillaire avec une baisse d’acuite visuelle a 1/50 en raison d’exsudats maculaires importants. Un traitement associant phototherapie dynamique et injection intravitreenne de triamcinolone est alors realise. Le troisieme cas est celui d’un homme de 23 ans atteint d’une maladie de Von Hippel-Lindau. L’exsudation de l’angiome capillaire n’atteint pas la macula, l’acuite visuelle est conservee. Conscient de la menace fonctionnelle possible, le patient demande la realisation d’un traitement. Les modalites de traitement sont les memes pour tous les patients. Elles associent une posologie conventionnelle de verteporfine a un doublement du temps d’exposition laser. Une nette regression tumorale est constatee dans tous les cas, 6 mois apres le traitement. Discussion La phototherapie dynamique a la verteporfine est un traitement efficace des angiomes capillaires papillaires et retiniens. Son innocuite sur les tissus adjacents semble superieure a celle de la cryotherapie ou de la photocoagulation. La recuperation fonctionnelle depend du niveau de l’atteinte maculaire. L’adjonction d’un traitement par triamcinolone permet d’agir sur les phenomenes exsudatifs. Conclusion La phototherapie dynamique est efficace dans le traitement des angiomes capillaires. La recuperation fonctionnelle depend de l’atteinte maculaire.

Introduction L’hypertension intracrânienne benigne est definie par les criteres diagnostiques suivants : presence de cephalees, absence de signe neurologique de focalisation, normalite de l’examen neuroradiologique, normalite de la biologie du liquide cephalorachidien avec augmentation de la pression a la ponction. Nous decrivons ici la prise en charge diagnostique et therapeutique des cas d’hypertension intracrânienne benigne suivis dans le service d’ophtalmologie du CHRU de Lille. Materiels et Methodes Dans cette etude retrospective, nous avons recherche pour chacun des patients un surpoids ainsi que la prise d’un traitement favorisant. L’aspect du fond d’œil, les cliches de papilles, le champ visuel et l’angiographie a la fluoresceine ont ete analyses. Le traitement prescrit, son efficacite sur l’œdeme papillaire et la notion de recidive ont ete recherches. Resultats Quinze patients repondaient aux criteres diagnostiques, dix femmes et cinq hommes. Douze presentaient un surpoids, trois prenaient un traitement potentiellement favorisant. Tous se plaignaient de cephalees, la moitie d’une baisse d’acuite visuelle et deux d’une diplopie par paralysie oculomotrice. Dans tous les cas, on constatait un œdeme papillaire et un champ visuel perturbe. Le traitement medical comportait, outre la ponction lombaire depletive, la prise d’acetazolamide par voie orale, associee parfois a une corticotherapie. L’arret du medicament potentiellement en cause et la perte de poids venaient completer ce traitement. Une patiente dut beneficier d’un traitement chirurgical devant la persistance de cephalees et une aggravation fonctionnelle progressive. Deux patients ont presente une ou plusieurs recidives apres arret de l’acetazolamide. Discussion L’atrophie optique par œdeme papillaire chronique est la complication majeure de l’hypertension intracrânienne benigne. Conclusion L’analyse de la papille et du champ visuel permet donc de juger de la gravite de l’affection et de l’efficacite du traitement.

Introduction Le granulome cholesterolique orbito-frontal est une pathologie rare : il correspond a une reaction inflammatoire entourant des cristaux de cholesterol. Materiels et Methodes Nous rapportons le cas d’un patient de 24 ans, victime d’un traumatisme orbitaire droit un an auparavant, adresse pour ptosis droit. Il presentait du meme cote une baisse d’acuite visuelle, une exophtalmie, une hypotropie, une limitation de l’elevation et un ptosis. Un scanner etait demande pour orienter le diagnostic. Resultats La tomodensitometrie retrouvait une masse intra-orbitaire extra-conique droite, supero-externe, refoulant le globe en bas et en dedans. Cette lesion etait bien limitee, spontanement isodense et heterogene, peu modifiee apres injection. Il existait de facon associee une osteolyse du toit orbitaire. Une exerese chirurgicale etait decidee, retrouvant une tumeur brune non liquidienne adherente a l’os, resequee en totalite. L’etude anatomopathologique montrait des cristaux de cholesterol associes a une reaction inflammatoire giganto-cellulaire a corps etranger et des depots hemosideriques, compatible avec un granulome cholesterolique. L’evolution etait tres favorable avec remontee de l’acuite visuelle, normalisation du test de Lancaster et disparition des signes orbitaires. Aucun signe de recurrence n’est intervenu au cours de l’annee de suivi. Discussion Environ cent vingt cas de granulomes cholesteroliques orbito-frontaux ont ete decrits dans la litterature. L’origine en serait une hemorragie intra-diploique de l’os frontal, peut-etre due a un traumatisme prealable (retrouve dans environ un tiers des cas) et/ou a une anomalie osseuse preexistante. Le tableau clinique et les caracteristiques radiologiques sont evocateurs mais le diagnostic est anatomopathologique. Les principaux diagnostics differentiels sont les tumeurs de la glande lacrymale et les kystes dermoides et epidermoides. Le traitement est systematiquement chirurgical avec des resultats tres satisfaisants. Conclusion Le granulome cholesterolique orbito-frontal represente une cause rare d’exophtalmie unilaterale. Sa physio-pathogenie reste imparfaitement connue et son traitement est chirurgical.

Introduction La chorioretinite syphilitique en plaques, decrite par Gass en 1990, est une manifestation de la syphilis secondaire, rare chez l’immunocompetent. Objectifs et Methodes Nous rapportons trois cas de syphilis oculaire chez des patients immunocompetents examines en l’espace de 4 mois. - Le premier, âge de 58 ans presente une baisse d’acuite visuelle bilaterale. Le tableau est celui d’une panuveite bilaterale avec des lesions plaquoides. L’aspect angiographique est caracteristique. La serologie syphilitique est positive dans le sang et le LCR. Le patient est immunocompetent. L’evolution est favorable avec un traitement de neurosyphilis : les lesions regressent, avec une cicatrice retinienne et restitution de l’acuite visuelle. - Le deuxieme patient, immunocompetent, de 38 ans presente une baisse d’acuite visuelle unilaterale dans un contexte de panuveite. Il existe au fond d’œil une large plaque chorioretinienne, caracteristique en angiographie. La serologie syphilitique est positive. L’evolution est satisfaisante avec un traitement de syphilis secondaire, le patient refusant une hospitalisation prolongee. - Le troisieme patient âge de 41 ans presente une baisse d’acuite visuelle bilaterale depuis un mois. On retrouve une chorioretinite dense bilaterale, d’aspect plaquoide avec vascularite occlusive majeure. L’angiographie revele des plaques caracteristiques. L’OCT met en evidence un important remaniement de l’architecture retinienne. Le terrain est similaire aux precedents. Avec un traitement de neurosyphilis, l’evolution est favorable sur un mode atrophique avec des sequelles fonctionnelles consequentes. Discussion L’incidence de la syphilis en Europe a explose ces dernieres annees, touchant majoritairement des hommes. L’atteinte oculaire se manifeste chez l’immunocompetent, comme chez l’immunodeprime par des lesions allant de l’uveite anterieure a l’atteinte chorioretinienne, avec vascularite en cas de diagnostic tardif. L’aspect angiographique des lesions est caracteristique. Conclusion Le diagnostic de syphilis doit etre evoque devant un aspect de plaques chorioretiniennes. En cas de diagnostic precoce, un traitement adapte permet la resolution des lesions et preserve la fonction visuelle.

Introduction Le xanthogranulome necrobiotique de l’adulte, atteignant les tissus oculaires ou orbitaires, est une pathologie rare pouvant etre associee a de nombreux desordres biochimiques ou hematologiques dont les lymphopathies. Materiels et Methodes Nous rapportons le cas d’une patiente de 83 ans, porteuse d’un myelome multiple, adressee pour tumefaction orbitaire droite d’extension rapide a l’hemiface. Macroscopiquement, la lesion avait un aspect jaunâtre, indure, et indolore. Le premier diagnostic evoque etait celui de plasmocytome. Un scanner et une biopsie orbitaire ont ete realises consecutivement. Resultats La tomodensitometrie montrait une infiltration par une masse charnue palpebrale inferieure droite s’etendant a l’espace extra-conique infero-lateral, avec infiltration de la graisse avoisinante. Cet aspect faisait evoquer un processus proliferatif ou inflammatoire. L’etude anatomopathologique retrouvait un infiltrat inflammatoire polymorphe, avec nombreux histiocytes microvacuolises, et des zones de necrose hyaline, compatible avec le diagnostic de xanthogranulome necrobiotique; elle ecartait un plasmocytome. Discussion Il n’existe pas de signes cliniques ou radiologiques specifiques du xanthogranulome necrobiotique : le diagnostic est clairement anatomopathologique. En revanche, la prise en charge n’est pas standardisee. Dans la litterature, les modalites therapeutiques proposees sont la radiotherapie, l’administration de corticoides et/ou d’une chimiotherapie, les immunosuppresseurs, la chirurgie. Dans le cas expose ici, le traitement retenu a ete une chimiotherapie (bortezomib et dexamethasone); la radiotherapie n’a pas ete retenue etant donne l’etat local et general de la patiente. Conclusion Le xanthogranulome necrobiotique de l’adulte est une entite rare, de diagnostic anatomopathologique. Il n’existe pas de consensus sur la prise en charge.

CDDP is a widely used antitumor agent effective in the treatment of solid tumors. Efforts to improve the response rates in advanced disease by escalating the dose have been limited by unacceptahle toxicity. Based on experimental and clinical studies indicating that reduced GSH is a protective agent against CDDP-induced neuro-, oto-, and nephrotoxicity, a raodomized clinical trial with high dose CDDP including GSH (Group A) or intensive hydration (Group B) was designed for patients with advanced Non small cell lung cancer (NSCLC) or Squamous-cell-carcinomas of the head, and neck (SCC). To date, a total of 21 patients (pls)(l8 males, 3 females) with a median age of 54 years (range 35–74) entered this study (NSCLC:n=5;SCC: n=16; all stage III and IV). All pts received 80 mg/m’ CDDP + YP·16 or 5-FU every 4 weeks for a minimum of 3 cycles. PIs in group A (n=ll) received 5 g of GSH before CDDP therapy and 2000ml of normal saline. The control group B (n=10) received 4000m1 of normal saline and forced diuresis only. A median of 5 cycles (range 1-10) has been given to these pts (median observation time: 17 months, range 529). 15/21 pts were currently evaluable for response (4pts early deaths, 2 withdrawals). The overall response rate was 14/15 (93%) pts (CR: 2/14=14%, PR 6/14=43%, SD 6/14=43%). The response rate in group A was 8/9 (89%) pts (CR 2/8=25%, PR 2/8=25%, SD 4/8=50%). In group B the overall response rate was 6/6 (100%) pts (CR 0/6: PR 4/6=67%, SD 2/6=33%). 16 pts were evaluable for myelotoxicity, nephrotoxicity and neurotoxicity: We observed in 3/9 (33%) pts of group A and in 5/7 (70%) pts of group B severe neutropenia (WHO grade IV only in group B). Nephrotoxicity was noticed in 1/16 (6%) pts (group B). Ototoxicity and neurotoxicity, evaluable in 10/20 pts, were mild and comperable between the two groups. This preliminary data shows, that GSH might be a protectic agent against CDDP-induced toxicities, with allows the reduction of hydration therapy and forced diuresis, without reducing anti-tumor activity of the cytotoxic agent.

Neoadjuvant chemotherapy of breast cancer results in high response rates of > 85%. This demonstrates a high sensitivity of breast cancer cells to cytostatic treatment as first-line intervention. Since response rates in generalized disease are considerably lower (40–45% for anthracyclin-monotherapy and 50–70% for polychemotherapy), we performed a matched-pair analysis to compare the response to first-line polychemo-therapy (FEC) of breast cancer patients generalized at diagnosis (group I, n=15) and patients with distant disease after surgery and > 1 year disease free interval (group II, n=35). Both groups were comparable in terms of age, hormone-receptor status, histological grading, pattern of metastasis, and menopausal status. No patient of group II had received anthracyclin-containing adjuvant therapy. We detected a significantly higher (p

Three-quarters of the Summerville Formation and a small portion of the Curtis Formation of central Utah have been sampled at close stratigraphic spacing. The two formations constitute an intertonguing marine-marginal marine, tidal flat sequence representing middle Callovian time. The magnetic polarity sequence observed is dominantly reversed with a few relatively short normal intervals. The age of these formations corresponds to some portion of time within the Jurassic oceanic quiet zone. The fact that normal polarity was not prominent in these formations casts some doubt upon the hypothesis that a long period of normal polarity was the cause of the quiet zone. Furthermore, a literature compilation indicates that normal polarity did not dominate the Jurassic as had been thought. The pole position determined from the Middle Jurassic Summerville Formation slightly revises earlier results and suggests a tiny amount of apparent polar motion relative to North American between Late Triassic and Middle Jurassic time.

Measurement of the remanent magnetization of samples of Jurassic oceanic red sediments recovered in the western Atlantic on Leg 11, site 105 of the Deep Sea Drilling Project yields quite different results, depending on the demagnetization processes used. Both the Jurassic section and the Berriasian-Valanginian part of the Lower Cretaceous were measured, but with less satisfactory results for the Lower Cretaceous. The natural remanent magnetization of the Jurassic section is almost entirely normal, with 44.6° inclinations (standard deviation = 13.9°) and is not changed by 1000 Oe alternating field (AF) demagnetization. Thermal demagnetization to temperatures of 630°C brings the inclination and polarity sequence in line with that expected for Oxfordian through Tithonian time at this site. The average inclination after thermal demagnetization is 22.1°, standard deviation = 12.1°, and the polarity pattern is one of frequently alternating polarity, much more similar to published reversal patterns for this time than the all normal results of AF demagnetization. The polarity pattern is not identical to the published ones as a result of insufficiently detailed sampling. Thermomagnetic and X-ray analyses were ambiguous, but suggest the presence of titanomagnetite, hematite, and possibly titanomaghemite and pyrrhotite. The primary remanence is carried by hematite.

The glycoprotein (GP) IIb-IIIa complex was isolated from human platelet membranes and examined for glycoprotein stoichiometry and morphology. To determine the ratio of glycoproteins in the complex, the isolated glycoproteins were solubilized with sodium dodecyl sulfate and separated by high-performance liquid chromatography. Quantitative amino acid analysis of individual glycoproteins showed that the ratio of GP IIb to GP IIIa in the Ca2+-dependent complex was 0.93:1. Morphology was determined by electron microscopy of rotary-shadowed and negatively stained specimens. Individual complexes consisted of two domains: an oblong head of approximately 8 X 10 nm with two rodlike tails extending approximately 14-17 nm from one side of the head. Treatment of the isolated complex with EDTA resulted in the appearance of a mixture of oblong and filamentous structures, which could be separated by a sucrose gradient sedimentation in Triton X-100. As seen by rotary and unidirectional shadowing, GP IIb was a compact structure, approximately 8 X 10 nm in size. Isolated GP IIIa was more heterogeneous but was most often observed in an elongated form, varying in length from 20 to 30 nm and in width from 2 to 3 nm. By comparing these structures to that of the heterodimer complex, it was determined that the oblong domain was GP IIb and the rodlike tails were GP IIIa. Each milligram of isolated GP IIb-IIIa complex bound 0.30 mg of [3H]Triton X-100, indicating that the glycoprotein complex contained limited hydrophobic domains. Upon removal of detergent, GP IIb-IIIa complexes formed aggregates that sedimented in sucrose gradients as a diffuse peak ranging from 14 to 32 s. Examination of these aggregates by electron microscopy showed that they were composed of clusters or "rosettes" of 2 to 20 or more of the GP IIb-IIIa complexes. The orientation of these rosettes was such that the tails were joined in the center, with the head portions directed away from the interacting tails. It thus appears that the primary hydrophobic domains of the GP IIb-IIIa complex exist at the tips of the GP IIIa tails. Because the GP IIb-IIIa complex is an intrinsic membrane glycoprotein, these findings indicate a potential membrane attachment site for the GP IIb-IIIa complexes.

Four sections in Majocian-Bathonian (Middle Jurassic) pelagic limestone with standard ammonite zonation have yielded magnetic polarity sequences. Magnetic directions in these red to white limestones were obtained by thermal demagnetization and were stable from about 300°C to in excess of 450°C. The polarity patterns indicate that the majority of the Bajocian and Bathonian is characterized by quite frequent reversals of the magnetic field. Lengthy periods of constant polarity, particularly constant normal polarity, were not observed. The average frequency of reversals is about 6 per ammonite zone, which roughly may be interpreted as a frequency of a reversal every 260,000 years, a rate comparable to that of the Miocene-Pliocene. Paleolatitudes of these sites (25–28°) are about 10° south of their present positions; variable clockwise block rotations within the Subbectic region have rotated these sites relative to stable Iberia.

A reproducible magnetic polarity pattern has been obtained from four overlapping stratigraphic sequences of ammonite-rich gray pelagic limestones, spanning part of the Middle and Late Oxfordian (G. transversarium toE. bimammatum ammonite zones). Progressive thermal demagnetization removed a present field overprint. Fold tests, both between- and within-outcrops, are positive. The mean direction of magnetization is 322°, 45° (α95 = 6°), which implies a paleolatitude of 26°N. Frequent changes of polarity were observed. The magnetostratigraphic sequence contains the ammonite zones, subzones, and horizons of the Tethyan faunal realm. Using the reference horizons provided by this detailed ammonite zonation, the polarity zones can be readily correlated among all sections. The composite polarity pattern is predominantly of reversed polarity, punctuated by a number of relatively shorter duration normal polarity intervals. In order to compare this sequence to that of the marine magnetic anomalies, we have revised the age estimates for the pre-M25 marine magnetic normaly pattern according to the most recent time scale. Based on those ages, the sedimentary record at Aguilon suggests a much greater frequency of polarity changes than does either model derived from the two sets of marine magnetic anomalies of this time. This sedimentary record probably is a truer approximation of the actual geomagnetic polarity history because of the continuity of sedimentation in these sections and the inherent ambiguities involved in determining a polarity pattern from the very low amplitudes that everywhere characterize this part of the marine record.

The glycoprotein IIb-IIIa complex (GP IIb-IIIa) is a platelet cell-surface receptor for fibrinogen and fibronectin. A carboxyl-terminal decapeptide of the fibrinogen gamma-chain (Leu-Gly-Gly-Ala-Lys-Gln-Ala-Gly-Asp-Val LGGAKQAGDV] and a tetrapeptide (Arg-Gly-Asp-Ser (RGDS] from the fibrinogen alpha-chain and the fibronectin cell-binding domain appear to mediate the binding of these ligands to GP IIb-IIIa. The present study was designed to examine the effects of these and related peptides on the structure of purified platelet GP IIb-IIIa. Treatment of GP IIb-IIIa with various synthetic peptides affected the glycoprotein so that GP IIb alpha became a substrate for hydrolysis by thrombin. The order of potency of these peptides was as follows: RGDS greater than LGGAKQAGDV greater than KGDS greater than RGES. This is the same order of potency in which these peptides inhibit fibrinogen binding to platelets. This effect was time-, temperature-, and concentration-dependent; RGDS induced a half-maximal effect at approximately 60 microM. In addition, RGDS, but not RGES, decreased the intensity of the intrinsic protein fluorescence of GP IIb-IIIa. Finally, the decapeptide or RGDS decreased the sedimentation coefficient of GP IIb-IIIa from 8.5 to 7.7 or 7.4 S, respectively, whereas RGES had a minimal effect. This decrease was accompanied by an increase in the Stoke's radius from 74 to 82 A with RGDS or 85 A with the decapeptide, indicating a peptide-induced unfolding of the GP IIb-IIIa complex. This change in conformation may be related to changes in the distribution and function of GP IIb-IIIa on the platelet surface that occur when adhesive proteins or peptides from the GP IIb-IIIa binding domains of these proteins bind to GP IIb-IIIa.

Two coeval sections of red to white ammonite-rich pelagic limestones spanning the complete Kimmeridgian and most of the Tithonian were sampled in detail. All samples were treated by progressive thermal demagnetization to remove a present field overprint. Characteristic magnetization is carried primarily by magnetite. Polarity intervals are easily identified and correlate well between the two sections. The Tithonian polarity sequence can also be correlated to sections in northern Italy. The similarity between the polarity sequence and the M-sequence of marine magnetic anomalies, coupled with the precise biostratigraphic control, allows assignment of the following ages to the M-sequence: the Late/Early Tithonian boundary is correlated to the end of M-20, the Tithonian/Kimmeridgian boundary to the end of M-23, the Late/Early Kimmeridgian boundary to the latter part of M-24, and the Kimmeridgian/Oxfordian boundary within or slightly after M-25. The mean directions of characteristic magnetization have α 95 's less than 3° and demonstrate extensive differential block rotation within the Subbetic province. Paleolatitudes during the Kimmeridgian/Tithonian are in the range of 16–24°N.

Polarity reversal sequences have been observed in the Brushy Basin Member of the Morrison Formation (Upper Jurassic, Kimmeridgian-Tithonian age) at two sites in western Colorado separated by 80 km. The two polarity reversal sequences display a good correlation of relative lengths and number of polarity intervals and thus may provide a significant correlation tool in this laterally variable formation. The whole polarity sequence observed in the Morrison Formation correlates very well with the oldest portion of lineated anomalies of the sea floor. The sedimentary record on land and the anomaly pattern of the oceanic crust both show the same relative lengths and approximate number of polarity intervals, as well as ratio of reversed to normal polarity.

Platelet membrane glycoprotein (GP) IIIa forms a Ca2+-dependent heterodimer complex with GP IIb. The GP IIb-IIIa complex constitutes the fibrinogen and fibronectin receptor on stimulated platelets. A biochemically and immunologically similar membrane glycoprotein complex is present on endothelial cells. A human umbilical vein endothelial cell cDNA library was screened using oligonucleotide probes designed from peptide sequences obtained from platelet GP IIIa. A cDNA clone was sequenced and found to encode a protein of 84.5 kDa. The translated endothelial cDNA contained five sequences that corresponded to peptide sequences in platelet GP IIIa, including the amino-terminal 19 residues. Thus, the endothelial and platelet forms of GP IIIa are apparently identical. Glycoprotein IIIa consists of a long amino-terminal extracellular domain with several potential N-linked glycosylation sites and four cysteine-rich tandem repeats, a 29-residue hydrophobic transmembrane segment, and a short carboxyl-terminal cytoplasmic domain. Glycoprotein IIIa has a 47% amino acid sequence homology to "integrin," a fibronectin receptor from chicken embryo fibroblasts. This homology suggests that GP IIIa is a member of a family of cell-surface adhesion receptors.

The platelet glycoprotein IIb-IIIa complex (GP IIb-IIIa) is a member of the integrin receptor family that recognizes adhesive proteins containing the Arg-Gly-Asp (RGD) sequence. In the present study the binding characteristics of the synthetic hexapeptide Tyr-Asn-Arg-Gly-Asp-Ser (YNRGDS, a sequence present in the fibrinogen alpha-chain at position 570-575) to purified GP IIb-IIIa were determined by equilibrium dialysis. The binding of 125I-YNRGDS to GP IIb-IIIa was specific, saturable, and reversible. The apparent dissociation constant was 1.0 +/- 0.2 microM, and the maximal binding capacity was 0.92 +/- 0.02 mol of 125I-YNRGDS/mol of GP IIb-IIIa, indicating that GP IIb-IIIa contains a single binding site for RGD peptides. The binding of 125I-YNRGDS to purified GP IIb-IIIa showed many of the characteristics of fibrinogen binding to activated platelets: the binding was inhibited by fibrinogen, by the monoclonal antibody A2A9, and by the dodecapeptide from the C terminus of the fibrinogen gamma-chain. In addition, the binding of 125I-YNRGDS to GP IIb-IIIa was divalent cation-dependent. Our data suggest that two divalent cation binding sites must be occupied for YNRGDS to bind: one site is specific for calcium and is saturated at 1 microM free Ca2+, whereas the other site is less specific and reaches saturation at millimolar concentrations of either Ca2+ or Mg2+. The results of the present study support the hypothesis that the RGD domains within the adhesive proteins are responsible for their binding to GP IIb-IIIa.

Paleomagnetic studies of Cretaceous rocks from more than 35 widely separated sites in North America show that the polarity at all but two of the sites is consistently normal, suggesting that the Cretaccous period may be characterized by a magnetic field dominantly of one polarity. The published literature concerning Cretaceous rocks substantiates this hypothesis and indicates that reversals are present primarily in the Lower Cretaceous and the upper portion of the Upper Cretaceous period. The longest period of constant normal polarity consistent with the data presently available is about 25 m.y. and is present in rocks from Upper Albian to middle Santonian age. Magnetic anomaly patterns at sea show a smooth interval older than anomaly 32 (80 m.y. in age) which may correspond to this long period of normal polarity observed in Cretaceous rocks from North America.

Sheridan and Suydam [1] raise several important points, which are primarily related to the origin of reported magnetic anomalies within the Jurassic magnetic quiet zone of the ocean crust, and therefore are not directly relevant to our magnetostratigraphic study of Oxfordian sediments [2]. We will discuss only two points: (1) the consistency of our Oxfordian results with other evidence of mixed polarity, and (2) the factors complicating the resolution of rapid magnetic reversals in the anomaly record of deep Jurassic crust.