Calcareous nannofossil biostratigraphy and paleoecology of the Cretaceous–Tertiary transition in the central eastern desert of Egypt

The Gebel Qreiya and nearby Wadi Hamama sections of the central Eastern Desert are among the most complete K/T boundary sequences known from Egypt. The two sections were analyzed spanning an interval from l.83 Myr below to about 3 Myr above the K/T boundary. A 1-cm-thick red clay layer at the K/T boundary at Gebel Qreiya contains an Ir anomaly of 5.4 ppb. The high-resolution study and well-preserved nannoflora provide good age control and the first quantitative records of calcareous nannofossil assemblages for paleoecological interpretations across the K/T transition in Egypt. Four zones (Micula murus, Micula prinsii, NP1, and NP2) were distinguished and correlated with other nannofossil and planktonic foraminiferal zonations that are broadly applicable for the eastern Tethys region. Latest Maastrichtian assemblages are abundant and diverse, though Cretaceous species richness progressively decreased across the K/T boundary. Dominant species include Arkhangelskiella cymbiformis, Micula decussata and Watznaueria barnesae, with high abundance of dissolution-resistant M. decussata reflecting periods of high environmental stress. Thoracosphaera blooms mark the K/T boundary and are followed by an acme of the opportunistic survivor Braarudosphaera bigelowii, the first appearance of the new Tertiary species Cruciplacolithus primus, and an acme of Coccolithus cavus/pelagicus. These successive abundance peaks provide the basis for subdivision of the Early Danian Zones NP1 and NP2 into five subzones. Correlation of selected nannofossil taxa from the Egyptian sections with those from various onshore marine and deep-sea sections provides insights into their paleoenvironmental and paleoecological affinities.     

Salinity tolerance in some mangrove species from Pakistan

Growth, ionic and water relations of three mangrove species viz. Avicennia marina, Ceriops tagal and Rhizophora mucronata werestudied in different seawater concentrations (0, 25, 50, 75 and 100%).All mangrove species showed optimal growth at 50% seawater. Relativelymore biomass was accumulated by R. mucronata while C. tagalhad the tallest individuals. Tissue water potential became more negativewith the increase in salinity and stomatal conductance was decreased in allplants. Higher stomatal conductance was noted in R. mucronata,followed by A. marina and C. tagal. Sodium and chloride ionsincreased with the increase in salinity and this accumulation was muchhigher in A. marina.     

Toe-to-thumb transfer: a new technique

Our technique combines the advantages of two proven techniques of the wraparound flap and vascularized joint transfer while offering a more normal thumb, both functionally and cosmetically. Its advantages are as follows: 1. A more normal-looking thumb with good length 2. Preservation of motion through joint transfer 3. Maintenance of growth potential through transfer of vascularized epiphyses 4. Minimal donor-site morbidity     

Identification of the uvrB gene product

We have constructed plasmids carrying various restriction fragments of the biouvrB region of the Escherichia coli chromosome. By analyzing the proteins synthesized in maxicells from the uvrB⁺ plasmid pDR1494, and its derivatives containing γδ sequences inserted in the uvrB gene, we have determined that the uvrB gene is about two kilobase-pairs in length, that it is transcribed clockwise on the standard E. coli genetic map, and that it codes for a single polypeptide of M_r = 84,000. The number of uvrB polypeptides in a normal cell is estimated to be about 140.We have also found that the uvrB gene is cut by EcoRI near its promoter.     

Effects of hyperaemia on left ventricular longitudinal strain in patients with suspected coronary artery disease

Aims

Myocardial perfusion imaging during hyperaemic stress is commonly used to detect coronary artery disease. The aim of this study was to investigate the relationship between left ventricular global longitudinal strain (GLS), strain rate (GLSR), myocardial early (E’) and late diastolic velocities (A’) with adenosine stress first-pass perfusion cardiovascular magnetic resonance (CMR) imaging.

Methods and results

44 patients met the inclusion criteria and underwent CMR imaging. The CMR imaging protocol included: rest/stress horizontal long-axis (HLA) cine, rest/stress first-pass adenosine perfusion and late gadolinium enhancement imaging. Rest and stress HLA cine CMR images were analysed using feature-tracking software for the assessment of myocardial deformation. The presence of perfusion defects was scored on a binomial scale. In patients with hyperaemia-induced perfusion defects, rest global longitudinal strain GLS (?16.9 ± 3.7 vs. ?19.6 ± 3.4; p-value = 0.02), E’ (?86 ± 22 vs. ?109 ± 38; p-value = 0.02), GLSR (69 ± 31 vs. 93 ± 38; p-value = 0.01) and stress GLS (?16.5 ± 4 vs. ?21 ± 3.1; p < 0.001) were significantly reduced when compared with patients with no perfusion defects. Stress GLS was the strongest independent predictor of perfusion defects (odds ratio 1.43 95% confidence interval 1.14–1.78, p-value <0.001). A threshold of ?19.8% for stress GLS demonstrated 78% sensitivity and 73% specificity for the presence of hyperaemia-induced perfusion defects.

Conclusions

At peak myocardial hyperaemic stress, GLS is reduced in the presence of a perfusion defect in patients with suspected coronary artery disease. This reduction is most likely caused by reduced endocardial blood flow at maximal hyperaemia because of transmural redistribution of blood flow in the presence of significant coronary stenosis.

     

Effect of dystocia on serum haptoglobin in Awassi ewes

Serum haptoglobin concentration was determined in 102 Iraqi Awassi ewes. Blood samples were collected from 82 ewes before the correction of dystocia, 10 ewes with eutocia 2 to 4 h after parturition and 10 nonpregnant ewes during the seasonal anestrus phase. The mean serum haptoglobin concentration was significantly higher (P < 0.01) in ewes with dystocia than in ewes with normal births and in the nonpregnant ewes. No significant difference was found between serum haptoglobin concentrations of ewes with ringwomb and ewes with dystocia due to other causes. There was a significant elevation (P < 0.01) of serum haptoglobin in cases treated 24 h after labor compared with those treated during the first 24 h. Significant (P < 0.05) differences were found between serum haptoglobin concentrations in ewes treated surgically and those treated manually.     

Isolation and identification of novel sulfur-containing metabolites of spironolactone (Aldactone®)

In the urine of subjects given an oral dose of spironolactone [3-(3-oxo-7α-acetylthio-17β-hydroxy-4-androsten-17α-y1)propionic acid γ-lactone], six metabolites have been detected. One of the major metabolites was found to be the previously characterized de-thioacetylated compound, 3-(3-oxo-17β-hydroxy-4,6-androstadien-17α-y1)propionic acid γ-lactone (canrenone). Besides this a new major sulfur-containing metabolite has been isolated and identified as 3-(3-oxo-7α-methylsulfinyl-6β,17β-dihydroxy-4-androsten-17α-y1)propionic acid γ-lactone. This structural assignment was based on detailed analysis of its IR, NMR and UV spectra as well as comparison of its physical constants and chromatographic (TLC and GLC) characteristics with a synthetic sample. The three minor metabolites were found to be very labile and were readily converted to canrenone.