Gamow-Teller matrix elements for two-neutrino double beta decay within a second quasi-random-phase approximation

The ascendency of the cerebral cortex in mammals naturally raises questions about the role of the archetypal subcortical centers we share in common with other phyla. Here we report a situation in which an ancient oculomotor control center, the nucleus of the optic tract, is not so much dominated by the cerebral cortex as served by it. We suggest that the organization of cortical output to subcortical centers may be helpful in understanding the function of the cerebral cortex.     

A leukocyte homologue of the IL-8 receptor CXCR-2 mediates the accumulation of macrophages in atherosclerotic lesions of LDL receptor-deficient mice

Cancer complicating pregnancy is uncommon, with an incidence of approximately 1 in 1000 pregnancies. The obstetrician attending 250 deliveries per year would need to accumulate 40 years of clinical experience to encounter two to three cases of PABC. The increases in the size, weight, vascularity, and density of the breasts associated with pregnancy make the detection of mass lesions difficult both clinically and mammographically. Most of the benign lesions seen in pregnancy are the same ones seen in the nongravid state. Most cases of PABC present as painless masses, and as many as 90% of these masses are detected by breast self-examination. Women with PABC generally have more advanced disease with larger tumors, a higher percentage of inoperable lesions, and a higher percentage of nodal involvement. Because most PABC presents with a palpable mass, the role of imaging modalities in the evaluation of these patients remains limited. Fine-needle aspiration cytology is the initial procedure of choice for evaluating breast masses during pregnancy and lactation. Therapeutic abortion does not improve survival. The general principle is to treat the cancer and to allow the pregnancy to proceed. No studies have shown an adverse effect of a subsequent pregnancy even in patients with positive axillary nodes and patients in whom pregnancy occurs earlier than 2 years after treatment.     

Scanning electron microscopic study and shear bond strength measurement with 5% and 37% phosphoric acid

Direct bonding of orthodontic attachments has become a clinical reality with the application of the acid etch technique, using 37% phosphoric acid. The objective of this study was to detect the etch pattern with scanning electron microscopy and the shear bond strength with a Hounsefield tensometer (Nene Instruments Ltd., Northampton, England) by using 37% and 5% phosphoric acid (H3PO4). It was observed that with 5% H3PO4 there was minimal enamel loss compared with 37% H3PO4. There was no significant difference in shear bond strength, when enamel surface was etched with 5% H3PO4 and 37% H3PO4.     

On the mechanism of 5-enolpyruvylshikimate-3-phosphate synthase

5-Enolpyruvylshikimate-3-phosphate (EPSP) synthase catalyzes the condensation of shikimate 3-phosphate (S3P) and phosphoenolpyruvate (PEP) to form EPSP, a precursor for the aromatic amino acids. This paper examines a recent claim [Studelska, D. R., McDowell, L. M., Espe, M. P., Klug, C. A., and Schaefer, J. (1997) Biochemistry 36, 15555-15560] that the mechanism of EPSP synthase involves two covalent enzyme-intermediates, in complete contrast to a large body of literature that has already proven the involvement of a single noncovalent intermediate. The evidence in the paper of Studelska et al. is examined closely, and unequivocal proof is provided that those authors' NMR assignments to covalent structures are in error, and that in fact the species they observed were simply the product EPSP and a side-product EPSP ketal. Since those authors used rotational-echo double-resonance (REDOR) solid-state NMR to measure intermolecular and intramolecular distances in the proposed covalent intermediates, we have used REDOR to measure the same distances in enzyme-free and enzyme-bound preparations of purified EPSP, and enzyme-free preparations of purified EPSP ketal. The distance between the shikimate ring phosphorus atom and C8 in enzyme-free EPSP is 6.6 +/- 0.1 A, which lengthens to 7.4 +/- 0.1 A in the presence of the enzyme, and in enzyme-free EPSP ketal is 5.6 +/- 0.1 A. These are entirely consistent with those measured by Studelska et al., which were 7.5 +/- 0.5 A for a putative enzyme-enolpyruvyl species and 6.1 +/- 0.3 A for a putative enzyme-ketal species.     

Risk of unprovoked seizure after acute symptomatic seizure: effect of status epilepticus

The dehydration effect is suggested as a mechanism of anesthetic action of magnetic fields. After half an hour of in vivo exposure in constant magnetic field of white male rats to SMF 0.2 T the dehydration of brain, kidney and liver tissues were detected, the decrease of ouabain binding in 5.10(-9) M concentration was detected in brain, heart, spleen and liver tissues and it was increased in kidney tissue. With prolongation of the exposure time the dehydration of the whole organism was observed.     

Changes in the cholesterol and phospholipid content of mouse spleen after Raucscher leukemia virus infection

The effect of Rauscher Leukemia Virus (MuLV-R) infection on the lipid composition of mouse spleen from BALB/c mice was investigated. Drastic changes in the lipid composition of the spleen as a result of tumor growth induced by the virus could be demonstrated at 21 days after infection. The molar ratio of cholesterol to phospholipids was found to be low, while a shift within the choline containing phospholipid classes resulted into a lower sphingomyelin and a higher phosphatidyl choline content of the MuLV-R infected spleen. The cholesterol ester content increased more than two-fold during tumor growth, and shifts in the fatty acid patterns of the lipids were demonstrated.