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Notes: [Auszug] Idiopathic hypogonadotropic hypogonadism(IHH) is one of the most common causes of hereditary hypogonadism. Affected males and females present with irreversible pubertal delay, low serum levels of the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone(LH),and sex steroids1. The ...

Notes: Capsules with beryllium ablators have long been considered as alternatives to plastic for the National Ignition Facility laser [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]; now the superior performance of beryllium is becoming well substantiated. Beryllium capsules have the advantages of high density, low opacity, high tensile strength, and high thermal conductivity. Three-dimensional (3-D) calculations with the HYDRA code [NTIS Document No. DE-96004569 (M. M. Marinak et al. in UCRL-LR-105821-95-3)] confirm two-dimensional (2-D) LASNEX [G. B. Zimmerman and W. L. Kruer, Comments Plasmas Phys. Controlled Thermonucl. Fusion 2, 51 (1975)] results that particular beryllium capsule designs are several times less sensitive than the CH point design to instability growth from deuterium-tritium (DT) ice roughness. These capsule designs contain more ablator mass and leave some beryllium unablated at ignition. By adjusting the level of copper dopant, the unablated mass can increase or decrease, with a corresponding decrease or increase in sensitivity to perturbations. A plastic capsule with the same ablator mass as the beryllium and leaving the same unablated mass also shows this reduced perturbation sensitivity. Beryllium's low opacity permits the creation of 250 eV capsule designs. Its high tensile strength allows it to contain DT fuel at room temperature. Its high thermal conductivity simplifies cryogenic fielding. © 1998 American Institute of Physics.

Notes: Abstract: Although multiple tests are often performed prior to surgery for the primary treatment of breast cancer, the role of perioperative testing has yet to be clearly defined. The purpose of this study was to examine the use of perioperative testing in the Department of Defense (DOD) health care system.Records from all patients who received an operation for breast cancer between April 1, 1990 and March 1, 1992 in the DOD health care system were reviewed. The results of bone scans (BS), abdominal CT scans, brain scans (CT, MRI), chest radiographs (CXR), blood tests, and specified parameters from the history and physical examination were analyzed. Chi-square statistics were performed.2,364 women underwent surgery for breast cancer during this period. The percentage of patients that received each test (A) and the percentage of the tests that were suggestive of metastatic disease (B) are as follows ([A%], [B%]): CXR (94%, 1.3%); BS (23%, 8%); abdominal CT (4%, 9%); and brain scans (1%, 11%). There were more abnormal BS in patients with an elevated alkaline phosphates than in those with a test that was normal or never performed (20% vs. 4.8%, p 〈 0.001). Elevated liver function tests or central nervous system signs or symptoms were not associated with abnormal studies.In the past, patients with breast cancer underwent an extensive array of blood tests, CXR, and scans of bones, liver, and brain in the attempt to detect occult metastatic disease prior to surgery. In a large and diverse system such as the DOD, however, a perioperative metastatic work-up, which includes a BS, brain scan, and abdominal CT scan is not routinely performed, suggesting that clinicians selectively perform specific tests during this period. Despite this tendency, when tests are performed on breast cancer patients in the perioperative period, they are infrequently suggestive of metastatic disease.

Notes: Keloids are the result of a dysregulated wound-healing process and are characterized by formation of excess scar tissue that proliferates beyond the boundaries of the inciting wound. In this study, we investigated the expression of key proteins involved in regulating apoptosis in keloids. Twenty archival paraffin-embedded keloid samples were randomly selected for an immunoperoxidase assay with antibodies against fas, p53, bcl-2, and bcl-x proteins using the target antigen-retrieval technique. Apoptosis was assessed in keloids and normal skin and in keloid and normal fibroblasts by the TdT-mediated dUTP nick-end labeling (tunel) assay on tissue sections, fibroblast cultures, and by flow cytometry for cell suspensions. We found that 18 of 20 keloids expressed p53 protein; bcl-2 was expressed by keloid fibroblasts in 19 of 20 keloids, and all specimens had prominent fas expression throughout the tissue. The distribution of these three antigens was regional within each lesion and followed a consistent pattern of p53 and bcl-2 expression colocalized to the hypercellular, peripheral areas of each keloid in a perinuclear pattern (p 〈 .001). In contrast, an inverse distribution of fas expression was shown, with staining being more diffuse across the cell surfaces and limited to the central, more hypocellular regions in 16 of 17 keloids (p 〈 .001). There was no specific staining pattern in these keloids with antihuman bcl-x. In vitro studies on cultured keloid fibroblasts (derived from six patients) revealed maintenance of the p53+, bcl-2+ phenotype up to passage 10. Neither neonatal nor normal adult skin fibroblasts expressed either antigen but could be induced to express p53 by exposure to adriamycin. Keloid lesions and keloid fibroblasts were found to have lower rates of apoptosis than normal controls. Keloid fibroblasts displayed enhanced apoptosis rates in response to hydrocortisone, γ interferon and hypoxia treatment as compared with normal adult fibroblasts. Focal dysregulation of p53 combined with upregulation of bcl-2 may help produce a combination of increased cell proliferation and decreased cell death in the younger hypercellular areas of the keloid. This phenotype is reversed in the older areas of the keloid and may prevent malignan degeneration, thus favoring normal apoptosis as evidenced by prominent fas expression.

Notes: Abstract: Local recurrence after mastectomy for invasive cancer generally carries a poor prognosis. Local recurrence after mastectomy for ductal carcinoma in situ (DCIS) is rare and its impact on survival is unknown. Sixty-eight patients were treated with mastectomy for DCIS at the Fox Chase Cancer Center between 1985 and 1996, and only one of these developed a chest wall recurrence. An additional five patients treated with mastectomy at other institutions and referred to Fox Chase after local recurrence were also identified. These six patients had only DCIS as their primary pathology. Four of the six patients were premenopausal (median age 42 years). The median interval to local recurrence was 5.0 years (2.8–9.3 years). The median follow-up from initial diagnosis was 10.5 years (4.3–26.7 years) and 5.2 years (1.4–17.6 years) from recurrence. All of the recurrences were invasive and treatment included wide local excision with radiotherapy in all of the patients followed by adjuvant chemotherapy for the premenopausal patients. None of the patients had metastatic disease at presentation. The disease-free survival from initial recurrence was 83% and 63% at 5 and 10 years, respectively. The 5- and 10-year survival following local recurrence was 80%. One patient died 3.6 years after recurrence with metastatic disease, while a second patient developed metastatic disease 11.8 years after her initial recurrence. The remaining four patients are alive (NED), ranging from 1.4 to 10.7 years following their local recurrence. Local recurrence following mastectomy for DCIS is rare, usually invasive, and may have a long interval to failure. Salvage using conventional multimodality therapy appears to result in long-term survival.

Notes: The stress rupture characteristics of an enhanced Nicalon/SiC composite at 900°C have been examined. This temperature has been identified as being in the regime wherein oxidation embrittlement is operative. The enhancement of the composite involves the use of a coating around the fiber tows, comprising a C-rich matrix and B-containing particulates. The efficacy of this oxidation protection scheme has been evaluated by comparing the stress rupture characteristics with those of both Nicalon/SiC composites without the enhancement and the fibers alone. Such comparisons indicate that a substantial portion of the strength loss is attributable to a degradation of the fibers, and that the performance of the enhanced material is marginally better than that of the reference (nonenhanced) composite. Moreover, at stress levels greater than the matrix cracking limit, oxidation embrittlement occurs rapidly and the rupture times (several hours) are short in relation to the targeted service lives of most ceramic composite components. The mechanisms associated with the embrittlement have been identified using scanning electron microscopy and Auger spectroscopy.

Notes: We demonstrate room-temperature pulsed operation of an electrically injected InGaN/GaN-based distributed feedback laser with an emission wavelength of 403 nm. The threshold current of a 1000-μm-long and 20-μm-wide device was 3.2 A; corresponding to a threshold current density of 16 kA/cm2. The 3rd order grating providing feedback was defined holographically and dry etched into the upper waveguiding layer by chemically assisted ion beam etching. We observed single mode operation of the laser with a side mode suppression ratio of 15 dB over a temperature range of about 30 K. © 1998 American Institute of Physics.

Notes: We present an on-line investment algorithm that achieves almost the same wealth as the best constant-rebalanced portfolio determined in hindsight from the actual market outcomes. The algorithm employs a multiplicative update rule derived using a framework introduced by Kivinen and Warmuth. Our algorithm is very simple to implement and requires only constant storage and computing time per stock in each trading period. We tested the performance of our algorithm on real stock data from the New York Stock Exchange accumulated during a 22-year period. On these data, our algorithm clearly outperforms the best single stock as well as Cover's universal portfolio selection algorithm. We also present results for the situation in which the investor has access to additional “side information.”

Notes: Laser-diode heterostructures of InGaAlN containing a third-order diffraction grating for distributed optical feedback have been examined with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The grating was defined holographically and etched by chemically assisted ion-beam etching into the upper GaN confinement layer of the laser structure. After the etch step, it was overgrown with an Al0.08Ga0.92N upper cladding layer. Threading dislocations were present that initiated at the sapphire substrate, but no new dislocations were observed at the grating/Al0.08Ga0.92N interface. A comparison of TEM and SEM micrographs reveals that there is a compositional gradient in the AlGaN upper cladding layer; however, calculations show that it did not reduce the optical coupling coefficient of the grating. © 1998 American Institute of Physics.