The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

[Breast MRI: Artefacts and pitfalls]

Multiple artefacts and pitfalls may occur with breast MRI. Artefacts are secondary to the MR technique itself while pitfalls often are the result of human error. The most common artefacts include motion, pulsation, chemical shift and magnetic susceptibility. The most common pitfalls include improper contrast injection, poor patient positioning, improper placement of the ROI and improper characterization of physiological and iatrogenic contrast enhancement. The identification of these artefacts and pitfalls on breast MR images may reduce their impact or even eliminate them. The use of optimized protocols is necessary. It is important to explain to patients the sequence of the examination, ensure proper placement of the breasts in the coil and optimize the contrast injection. The ROI should always be placed over the most suspicious region of the lesion. Finally, it is recommended to perform the MRI during the second week of the menstrual cycle and to discontinue the use of HRT 2 months prior to scanning when possible.

Magnetic fluctuation power near proton temperature anisotropy instability thresholds in the solar wind

The proton temperature anisotropy in the solar wind is known to be constrained by the theoretical thresholds for pressure-anisotropy-driven instabilities. Here, we use approximately 1x10;{6} independent measurements of gyroscale magnetic fluctuations in the solar wind to show for the first time that these fluctuations are enhanced along the temperature anisotropy thresholds of the mirror, proton oblique firehose, and ion cyclotron instabilities. In addition, the measured magnetic compressibility is enhanced at high plasma beta (beta_{ parallel} greater, similar1) along the mirror instability threshold but small elsewhere, consistent with expectations of the mirror mode. We also show that the short wavelength magnetic fluctuation power is a strong function of collisionality, which relaxes the temperature anisotropy away from the instability conditions and reduces correspondingly the fluctuation power.

Activation of kinin B receptor triggers differentiation of cultured human keratinocytes

BACKGROUND

Keratinocyte life span is modulated by receptors that control proliferation and differentiation, key processes during cutaneous tissue repair. The kinin B(1) receptor (B(1)R) has been reported in normal and pathological human skin, but so far there is no information about its role in keratinocyte biology.

OBJECTIVES

To determine the consequence of kinin B(1)R stimulation on tyrosine phosphorylation, a key signalling mechanism involved in keratinocyte proliferation and differentiation.

METHODS

Subconfluent primary cultures of human keratinocytes were used to investigate tyrosine phosphorylation, epidermal growth factor receptor (EGFR) transactivation, cell proliferation and keratinocyte differentiation. Cell proliferation was assessed by measuring bromodeoxyuridine incorporation whereas assessment of cell differentiation was based on the expression of filaggrin, cytokeratin 10 (CK10) and involucrin.

RESULTS

The major proteins phosphorylated, after B(1)R stimulation, were of molecular mass 170, 125, 89 and 70 kDa. The 170- and 125-kDa proteins were identified as EGFR and p125(FAK), respectively. Phosphorylation was greatly reduced by GF109203X and by overexposure of keratinocytes to phorbol 12-myristate 13-acetate, indicating the participation of protein kinase C. B(1)R stimulation did not increase [Ca(2+)]i, but triggered EGFR transactivation, an event that involved phosphorylation of Tyr(845), Tyr(992) and Tyr(1068) of EGFR. B(1)R stimulation did not elicit keratinocyte proliferation, but triggered cell differentiation, visualized as an increase of filaggrin, CK10 and involucrin. Blockade of EGFR tyrosine kinase by AG1478, before B(1)R stimulation, produced an additional increase in filaggrin expression.

CONCLUSIONS

The kinin B(1)R may contribute to keratinocyte differentiation and migration by triggering specific tyrosine signalling pathways or by interacting with the ErbB receptor family.

The turbulent Alfvénic aurora

It is demonstrated from observations that the Alfvénic aurora may be powered by a turbulent cascade transverse to the geomagnetic field from large MHD scales to small Alfvén wave scales of several electron skin depths and less. We show that the energy transport through the cascade is sufficient to drive the observed acceleration of electrons from near-Earth space to form the aurora. We find that regions of Alfvén wave dissipation, and particle acceleration, are localized or intermittent and embedded within a near-homogeneous background of large-scale MHD structures.

Evidence for modulation of human epidermal differentiation and remodelling by CD40

BACKGROUND

It is widely accepted that CD40 plays a critical role in the regulation of immune response. However, the significance of CD40 expression on normal human keratinocytes is only partially known.

OBJECTIVES

To perform a morphological re-examination of the role of CD40 on the differentiation of human keratinocytes and remodelling of the epidermis.

METHODS

Keratinocytes were grown on fibroblasts transfected with the CD40 ligand (CD40L) to investigate the formation of epidermal sheets in culture under the influence of the CD40L. Control experiments were carried out using the same cells but transfected with CD32. Further, three specific anti-CD40 monoclonal antibodies were used as soluble agonists to analyse the effect of CD40 ligation on keratinocyte differentiation.

RESULTS

Epidermal sheets developing from keratinocytes cocultured with fibroblasts transfected with CD40L but not with CD32 showed an up to 50% reduction in thickness compared with control sheets. This change depended mostly on cellular flattening and a decrease in the number of cell layers, and was coincident with a transient decrease in cell surface CD40 immunoreactivity. On the other hand, normal epidermis, and freshly isolated and cultured keratinocytes revealed a predominant CD40+/Ki-67- phenotype that was demonstrated by double immunocytochemistry. Consistent with these observations, keratinocytes primed with interferon-gamma responded to the three soluble agonists, but not to control IgG1, producing immunoreactive (pro)filaggrin and displaying morphological changes in shape and size equivalent to those seen in differentiated cells.

CONCLUSIONS

As a whole, our findings provide evidence that CD40+ keratinocytes represent a poorly differentiated population, not actively engaged in the cell cycle, which under specific stimulation is committed towards terminal differentiation.

[Imaging of myomas: is preoperative MRI usefull?]

Leiomyomas are the most common uterine neoplasms. Leiomyomas classified as intramural, submucosal, or subserosal are usually associated with various types of degeneration. The diagnosis and the treatment of leiomyomas vary among these subtypes of leiomyomas. Magnetic resonance imaging is the most accurate imaging technique for detection, localization, and characterization of myomas. The differential diagnosis at MR imaging includes adenomyosis and solid adnexal masses. Despite its relatively high cost, MR imaging is a very useful procedure which can assist preoperative planning.

[Retrotracheal cystic mass in the mediastinum]

We describe a case of retro-tracheal mass of the visceral compartment of the mediastinun in a 79-year-old woman revealed by signs of tracheal compression. Visualization of a vascular image coming from the cervical zone on reconstructed injected CT, and biological demonstration of a primary hyperparathyroidism led to the diagnosis of ectopic parathyroid adenoma, in spite of the cystic aspect of that tissular mass. Surgery by cervical approach was able to remove this mass without any problem. Pathological examination confirmed that it was a parathyroid adenoma with necrotic modifications. Follow up show a clinical and a biological improvement.

Chiropractic care of a patient with vertebral subluxations and unsuccessful surgery of the cervical spine

OBJECTIVE

The chiropractic care of a patient with vertebral subluxations, neck pain, and cervical radiculopathy after a cervical diskectomy is described.

CLINICAL FEATURES

A 55-year-old man had neck pain and left upper extremity radiculopathy after unsuccessful cervical spine surgery.

INTERVENTION AND OUTCOME

Contact-specific, high-velocity, low-amplitude adjustments (i.e., Gonstead technique) were applied to sites of vertebral subluxations. Rehabilitation exercises were also used as adjunct to care. The patient reported a decrease in neck pain and left arm pain after chiropractic intervention. The patient also demonstrated a marked increase in range of motion (ROM) of the left glenohumeral articulation.

CONCLUSION

The chiropractic care of a patient with neck pain and left upper extremity radiculopathy after cervical diskectomy is presented. Marked resolution of the patient's symptoms was obtained concomitant with a reduction in subluxation findings at multiple levels despite the complicating history of an unsuccessful cervical spine surgery. This is the first report in the indexed literature of chiropractic care after an unsuccessful cervical spine surgery.

Progressive increases in de novo methylation of CpG islands in bladder cancer

We conducted a quantitative analysis of the extent of de novo methylation of four CpG islands in human urinary transitional cell carcinomas of different stages and grades to determine how frequently these CpG islands became methylated in transition cell carcinomas during progression. The CpG islands included exon 5 of PAX6, exon 2 of p16, the 5' end of the deleted in bladder cancer gene, and the 5' end of transmembrane protein containing epidermal growth factor and follistatin domains. These sequences were not methylated in normal urothelial tissues; however, 48 of the 54 tumors examined (89%) showed methylation levels in excess of 20% for at least one of the markers. The number of markers concurrently methylated in individual tumors increased with the stage of the tumor, with several of the more aggressive invasive cancers showing hypermethylation of all four markers compared with the less aggressive invasive cancers. However, considerable methylation defects were present in superficial, preinvasive, papillary tumors. These data demonstrate that 89% of bladder cancers have increased methylation of CpG islands relative to their normal counterparts and suggest the occurrence of a hypermethylator phenotype in which multiple independent CpG islands become concurrently methylated in individual tumors in a process associated with tumor progression.

[Complications of percutaneous nephrostomy. Apropos of 481 procedures: the value of puncture of the median calices]

The authors report on a series of 481 percutaneous nephrostomy procedures, and describe the complications encountered. 163 percutaneous nephrostomies for drainage and 318 percutaneous stone removals, were performed between 1985 and 1995 in the Radiology Department of Hôtel-Dieu de France Hospital under fluoroscopy. One tract was needed for PN but more than one was sometimes necessary for percutaneous stone removal. Complication rate was identical to the results reported in the literature. Complications were more frequently encountered when the upper calyx was punctured (intercostal approach), mostly pleural lesions. Puncture of the middle and inferior calyx were associated with the same rate of complications, but with different degrees of severity. Major complications (80% of cases of hemorrhage, including all arteriovenous fistulae and pseudoaneurysms) were encountered with the puncture of the lower calyx while those associated with the puncture of the middle calyx were minimal. Thus, puncture of the middle calyx is the least morbid. It is recommended by the authors, whenever possible.

Changes in the rate of RNA synthesis during the cell cycle

BACKGROUND

Although the rate of RNA synthesis is known to drop at mitosis, the recent identification of 11 stages in the cell cycle (El-Alfy et al., 1994) makes it possible to measure the rate of this synthesis at each one of the stages and thus find out how it varies throughout the cell cycle.

METHODS

Mice were injected intravenously with the RNA precursor, 3H-uridine; the duodenum was fixed 5-15 minutes later for embedment in Epon, and the duodenal crypts were cut in semithin serial sections for study of the rapidly dividing crypt columnar cells. Using Feulgen-stained sections, each cell nucleus was assigned to one of the 11 stages described in the cell cycle, and the same nucleus was identified in the next serial section that had been processed for radioautography, so that the overlying silver grains were enumerated. The count was taken as an index of the rate of RNA synthesis by this nucleus.

RESULTS

Starting from stage I of the cell cycle (the period defined by the presence of a minimal amount of chromatin during which the S phase begins) and up to stage IV (when the S phase ends and the G2 phase begins), all or nearly all nuclei are synthesizing RNA with the rate peaking at stage III. During stages V to VIII (the period comprising the mitotic steps), the percentage of RNA-synthesizing nuclei decreases to over half at stage V (prophase), -10% at stages VIa (prometaphase) and VIb (metaphase) and none at stages VII (anaphase) and VIII (telophase). During stages IX-XI (which correspond to the G1 phase), the percentage rises sharply at stage XI to reach up to 100% at stages X and XI. Finally, on the average, 35% of nuclear silver grains are over the nucleolus (presumably representing ribosomal RNA precursors), whereas 65% are over the nucleoplasm (presumably representing mainly heterogeneous RNA precursors).

CONCLUSIONS

Cells synthesize RNA during the interphase, but at a variable rate with a peak in S. The synthesis proceeds in a majority of the cells at prophase, but only in a few of them at prometaphase and metaphase, and in none at anaphase and telophase.

Early detection of breast carcinoma: a comparison of palpable and nonpalpable lesions

A retrospective study of 536 needle-localization biopsies of nonpalpable breast lesions and 623 excisional biopsies of palpable breast lesions was performed. Carcinoma was present in 17.9% of needle-localization biopsy specimens and in 11.1% of excisional biopsy specimens. Noninvasive carcinoma constituted 50% of carcinomas detected by needle-localization biopsy and only 7.3% of carcinomas detected by excisional biopsy (p less than 0.005). Invasive carcinoma detected by needle-localization biopsy was associated with axillary lymph node metastasis in 9.8% of patients who had axillary dissection, compared with 37.7% of patients with invasive carcinoma detected by excisional biopsy of a palpable mass (p less than 0.005). Invasive carcinoma detected by needle-localization biopsy was less than 2 cm in size (T1) in 93.5% of biopsy specimens; in contrast, invasive carcinoma detected by excisional biopsy was less than 2 cm in size in only 54.7% of biopsy specimens (p less than 0.005). Nonpalpable breast lesions that proved to be invasive carcinoma were pathologic stage I in 82.9% of patients. Palpable breast lesions that proved to be invasive carcinoma were pathologic stage I in only 47.2% of patients. Survival benefits of mammographic screening and biopsy of nonpalpable lesions are likely the result of detection of invasive carcinoma at an early stage and detection of noninvasive carcinoma that may later develop into or mark increased risk of invasive carcinoma.

2,8-dihydroxyadenine urolithiasis: report of a case first diagnosed after renal transplant

We report a case of homozygous adenine phosphoribosyl transferase (APRT) deficiency associated with 2,8-dihydroxyadenine stones recurrent in a patient with a renal transplant. The disease was diagnosed 23 years after the initial episode of renal colic. At that time the disease was unknown. Our patient is only the second case of this disorder reported from the United States. Correct diagnosis is important because long-term maintenance with allopurinol and a low purine diet can effectively prevent stone formation and renal failure.

Behavioral effects of acute hexamethonium in rats chronically intoxicated with nicotine

To investigate the effects of chronic nicotine administration on feeding behavior, hexamethonium, a nicotinic blocker with mainly peripheral actions, was acutely given to rats during and after chronic nicotine administration. Nicotine decreased both the time spent investigating the food and the amount of food consumed. It also decreased the time spent rearing and grooming and increased the time spent resting. These behaviors returned to control levels after nicotine withdrawal. During nicotine administration, 10 mg/kg of hexamethonium increased the amount of time the nicotine-treated rats spent investigating the food but did not change the amount of food actually eaten. These data show that predominantly peripheral nicotinic blockade can partially alleviate the effects of chronic nicotine administration of feeding behavior, suggesting that at least some of the effects of nicotine on feeding are peripheral. The finding that the investigational and consummatory aspects of feeding behavior can be pharmacologically differentiated implies that some aspects of their neural control may be distinct.

[Hypoglycemia caused by lidocaine overdosage]

Hypoglycaemia with manifest clinical symptoms has been observed in four patients with cardiac insufficiency after infiltration of high doses of lidocaine prior to surgery. The depressing influence of lidocaine on blood glucose levels has also been seen in six out of 12 patients to whom a pacemaker was implanted in local anaesthesia. The interaction between hepatic glucose- and lidocaine-metabolism could possibly be responsible for this effect. Therefore the evaluation of blood glucose level and iv. administration of glucose is advisable in patients with systemic toxic reactions following lidocaine overdosage to avoid unnecessary symptomatic therapy.

Cardiac output, left ventricular ejection rate, plasma volume, and heart rate changes in equine laminitis-hypertension

Acute laminitis-hypertension was produced experimentally by carbohydrate overloading of the gastrointestinal tract in 8 horses, and the resulting hemodynamic changes were measured. Statistically significant (P less than 0.01) increases in cardiac output, left ventricular ejection rate, heart rate, and arterial pressure were related to statistically nonsignificant changes in peripheral resistance and a delayed (Obel grade 3 plus 24 hours) decrease in plasma volume. When compared with control values, the doubling of cardiac output and left ventricular ejection rate simultaneous with little or no change in either peripheral resistance or plasma volume (16 hours after the occurrence of Obel grade 3 lameness) was suggestive of an increase in myocardial contractility. Because these pathophysiologic phenomena have important time relationships to the onset of Obel grade 3 lameness in acute laminitis, the results of this investigation are discussed in light of their relationship to clinical signs, serum electrolyte changes, plasma L-lactate alterations, and histologic deterioration of the digit.

[Spontaneous adrenal hemorrhage. Apropos of a case]

Spontaneous adrenal haemorrhages are rare but non exceptional. They mainly occur in elderly men (mean age: 61 years). The main risk factors are: anticoagulant therapy (prescribed for myocardial infarction, occlusive vascular ou thromboembolic disease), hypertension and chronic respiratory insufficiency, as in the present case. The clinical picture is one of abdominal of lumbar pain with abdominal distension, circulatory collapse, often delayed and sometimes preceeded by an hypertensive bout, quite often fever with leucocytosis. Hyponatraemia and hyperkalaemia, are not constant features. The diagnosis is often not made until laparotomy, and it even can be missed there. In fact, plasma cortisol level or, if unavailable, urinary corticosteroid measurements are the best diagnostic procedures, permitting adequate therapy and giving best chances of survival. They must always be made in a patient with abdominal signs falling into one of the above mentioned etiologic categories.