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Two years after pelvic irradiation for prostatic cancer, bilateral protrusio acetabuli and collapse of the right femoral head requiring prosthetic arthroplasty developed in a 73-year-old man with chronic rheumatoid arthritis. There was no evidence of metastases. Histologic evaluation showed empty lacunae in the bone but no evidence of obliterative endarteritis. Osteonecrosis and pathologic fractures constitute a rare complication of high voltage irradiation.

The healing of surgically induced defects in mature rabbits' hyaline cartilage was examined histologically and biochemically. The subchondral bone underneath the lesion was the source of repair. At the end of the first month, mushroom-shaped chondroid buds were seen sprouting from the subchondral bone. By the tenth week, these buds fused to a cartilagenous plug filling the lesion. The repaired cartilage synthesized Type II collagen.

Data from the DMSP/F7 satellite dosimeter star event counters are presented. The DMSP dosimeter star event counters measure the number of pulses that exceed set energy deposition levels (40 MeV for three detectors and 75 MeV for the fourth detector) behind four different thicknesses of aluminum shielding. The term "star event" is used because linear energy transfer depositions above 40 MeV can be produced by high energy proton or heavy ion interactions with nuclei in the detector creating a star type release of energetic secondaries. The energy deposition that creates the high energy pulses in the detectors can come either directly from incident cosmic rays, directly from high energy protons that traverse long path lengths in the detector volume, indirectly from nuclear reactions in the detector created by incident high energy protons, or indirectly from nuclear reactions in the vicinity of the detector which create recoiling nuclei that deposit energy in the detector. These nuclear stars and direct energy pulses create single event upsets (SEUs) in microelectronic components in the near-Earth space environment. Here we will first describe the properties of the star channel of the dosimeter on DMSP/F7; then present the star count maps of the 840 km region of space; and finally discuss their relation to upset phenomena.

Previous work from this laboratory has shown that glucocorticoids and (Sp)-cAMPS, a cyclic AMP analogue, stimulate the accumulation of angiotensinogen mRNA in isolated hepatocytes. The present study demonstrated that glucocorticoids stimulate the accumulation of a novel, 2.25-kilobase transcript of the angiotensinogen gene, both in isolated hepatocytes and in the intact liver. (Sp)-cAMPS was synergistic with dexamethasone in causing the accumulation of the larger species of RNA in hepatocytes, but had no effect by itself. Primer extension analysis and S1 mapping experiments proved that the 2.25-kilobase angiotensinogen RNA consisted of two larger forms of angiotensinogen RNA extended at their 5' ends. The novel transcripts are generated by the use of two new transcription initiation sites in the angiotensinogen gene, located at nucleotide positions -328 and -386 relative to the start site at position +1 used in the absence of hormone. A consensus TATA box is found at the expected position 25-30 nucleotides upstream from the start site at position -328, and another TATA-like sequence is found 25-30 nucleotides upstream from the start site at -386. In addition, two consensus glucocorticoid response elements occur upstream from the initiation sites. The larger angiotensinogen RNAs do not appear to code for a novel form of the angiotensinogen protein. It appears that glucocorticoids can direct transcription from a second promoter in the angiotensinogen gene and that this promoter is absolutely dependent on the hormone. To date, this situation appears to be unique to the angiotensinogen gene.

Recent studies have shown that porous calcium phosphates provide a scaffold for bony ingrowth in various anatomic sites. In this preliminary investigation a type of porous calcium phosphate ceramic was implanted in the vertebral columns of 21 rabbits; the ceramic was studied as a possible bone graft substitute for use in spinal fusions. Animals were killed at three, six, eight, 12, and 24 weeks. Roentgenograms and histologic sections of the implant site were then obtained. Bony tissue ingrowth was progressing during the study period. Woven bone was found by six weeks after implantation, and lamellar bone was evident at 12 weeks. By 12 weeks the bony ingrowth had reached the central portion of the ceramic block. There was no fibrous tissue barrier to normal ossification. This type of calcium phosphate ceramic is compatible with bony ingrowth when implanted in the vertebral column of rabbits.

Phorbol ester sensitive EL4 cells become growth-inhibited and produce interleukin 2 when treated with phorbol-12, 13-dibutyrate. Resistant cells lack both responses. To determine whether the defect in phorbol ester-resistant EL4 cells occurs pre- or post-transcriptionally, a hybridization assay for interleukin 2 mRNA was developed using two synthetic oligonucleotides complementary to mouse interleukin 2 mRNA as probes. Both probes hybridized to a 1-kilobase band in RNA from phorbol ester-treated sensitive cells. This RNA was detectable within 3 h of phorbol ester administration, and accumulation peaked by 12 h. The 1-kilobase band was induced in a concentration-dependent manner by 4-beta-phorbol-12, 13-dibutyrate but not by the inactive analog, 4-alpha-phorbol-12, 13-dibutyrate. No bands hybridizing with the interleukin 2 probe were detected in RNA isolated from unstimulated cells or from phorbol ester-resistant EL4 cells at any time up to 24 h following phorbol ester stimulation. The accumulation of the RNA in sensitive cells was blocked when the protein synthesis inhibitors, cycloheximide (75 microM) or puromycin (90 microM) were added within 1 h of the addition of phorbol ester. If cycloheximide was added 2 or more h after phorbol ester treatment, superinduction of the 1-kilobase band was observed. These results indicate that the failure of phorbol ester-resistant EL4 cells to produce interleukin 2 is due to a defect proximal to interleukin 2 transcription and that the accumulation of interleukin 2 mRNA in phorbol ester-sensitive EL4 cells requires protein synthesis.

The topographical distribution of rat brain angiotensinogen (Ao) mRNA was determined using hybridization histochemistry (in situ hybridization) with two different hybridization probes, a 32P-labelled 42 residue oligonucleotide and a full-length complementary (antisense) RNA labelled with either sulfur 35 or phosphorus 32. Low levels of Ao mRNA sequences were detected throughout the brain while high levels were restricted to specific areas often corresponding to classical nuclear boundaries. All areas in which angiotensin II-like immunoreactivity had been previously detected contained moderate to high levels of Ao mRNA and many previously undetected areas were also found to contain high levels of this mRNA. The results underline the ubiquitous presence of angiotensinogen-synthesizing cells in the brain and support previous evidence that the angiotensinogen gene could be expressed by several types of brain cells.

Hyperfine-structure parameters and isotope shift of the 9/2$^−$ isomeric state in $^{187}$Au relative to $^{197}$Au for the 267.6-nm atomic transition have been measured for the first time using the in-source resonance-ionization spectroscopy technique. The magnetic dipole moment and change in the mean-square charge radius for this 9/2$^−$ isomer have been deduced. The observed large isomer shift relative to the 1/2$^+$ ground state in $^{187}$Au confirms the occurrence of the shape coexistence in $^{187}$Au proposed earlier from the analysis of the nuclear spectroscopic data and particle plus triaxial rotor calculations. The analysis of the magnetic moment supports the previously proposed 9/2$^−$, 1/2$^−$[541] assignment at moderate prolate deformation for $^{187}$Au$^m$.

The Echo 7 experiment is discussed. Echo 7 studied the electric and magnetic field configurations and the diffusion and energization of electrons moving along field lines crossing the equatorial plane between 6 and 10 R(E), where the inner plasma sheet interacts with the dipole field. Echo 7 also studied the beam-system interaction with the local auroral zone ionosphere. The methods used in these studies and the results achieved are reviewed. 28 refs.

ispartof: ISOLDE Newsletter 2017 nrpages: 14 status: published