Epitopes for thyroid stimulating and blocking autoantibodies on the extracellular domain of the human thyrotropin receptor

The majority (97%) of functional epitopes for stimulating thyrotropin receptor (TSHR) antibodies (stimulating TSHRAbs) in a large cohort (n = 59) of Japanese Graves' patients exists on the N-terminal region of the extracellular domain of TSHR, between residues 25 and 165 numbering from the methionine start site. This was determined by measuring the loss of stimulating activity in the Cos-7 cells transfected with TSHR/lutropin-choriogonadotropin receptor (LH-CGR) chimeras wherein TSHR residues 89-165 (Mc2) or 8-165 (Mc1 + 2) are replaced by comparable LH-CGR residues. There is no comparable loss when stimulating TSHRAb activity is measured in an Mc4 chimera, wherein TSHR residues 261 to 370 are replaced. In contrast, immunoglobulin (IgG) preparations from 35 patients with Hashimoto's disease or idiopathic myxedema, who have blocking TSHRAbs causing hypothyroidism, loose blocking TSHRAb activity in the Mc4 chimera, but not the Mc2 or Mc1 + 2 chimeras. Thus, in a large population of Japanese patients with autoimmune thyroid disease caused by TSHR autoantibodies, the major functional epitope for stimulating TSHRAbs is on the N-terminal portion of the TSHR extracellular domain, whereas that for blocking TSHRAbs is on the C-terminal portion of the extracellular domain. To further evaluate the nature of the critical functional epitope between residues 90 to 165, we divided this region approximately in half, creating chimeras Mc2a and Mc2b with, respectively, residues 90-124 or 125-165 replaced by comparable LH-CGR residues. IgGs from all patients tested lost significant stimulating activity using the Mc2a and Mc2b chimeras; however, when present, residual stimulating TSHRAb activity was evident on one or the other half of the region or on both halves, indicating that both segments are required for expression of the stimulating TSHRAb epitope within residues 90-165. Finally, we have identified a complex epitope involving both the N- and C-terminal portion of the extracellular domain that appears to account for the small fraction of stimulating TSHRAbs whose activity is not solely dependent on residues 25 to 165. Thus, using chimeras Mc1 + 2 + 4, with TSHR residues 8-165 and 261-370 substituted, or chimera Mc1 + 2 + 3 + 4, with residues 8-370 substituted, as well as Mc2, Mc1 + 2, and Mc4, we show that the Graves' IgGs which maintain stimulating TSHRAb activity when residues 8-165 of the TSHR are replaced by LH-CGR residues have an epitope involving residues 90-165 and the immunogenic 15mer peptide (YYVFFEEQEDEIIGF), residues, 352-366. Because that peptide can decrease the stimulating TSHRAb activity of these Graves IgGs in assays with the Mc2 chimera alone, we speculate that this complex epitope may be important in an epitope spreading process involved in the formation of stimulating TSHRAbs.     

Mouse lung epithelial cell lines--tools for the study of differentiation and the neoplastic phenotype

Several dozen lung epithelial cell lines have been established in culture over the past 20 years from normal lung explants and their spontaneous transformants, and from lung tumors that arose spontaneously or were induced with chemicals, viruses, or oncogenic transgenes. To provide information from which to choose appropriate lines for investigating problems in lung cell biology and pulmonary neoplasia, this review describes the origins of these lines and some of their characteristics. These include growth, morphology, tumorigenicity, ability to metastasize, xenobiotic metabolism, mutational status, signal transducing activities, cytogenetics, ability to form domes, and electric conductance. In addition to collecting this information in a single place for the first time, we describe previously unpublished apoptosis features of some of these lines. An increasing number of investigations are beginning to use these lines and this review contains references into 1997.     

High performance single frequency fiber grating-basederbium/ytterbium-codoped fiber lasers

The device characteristics of Er³⁺,Yb³⁺ single frequency fiber lasers are reported. A 5-cm long 1550-nm distributed feedback fiber laser with 4 mW output power is shown to have excellent specifications in terms of optical linewidth, signal-to-noise ratio (SNR), relative intensity noise, side-mode suppression and polarization purity. For higher power applications, a 1.5 cm single frequency Er³⁺,Yb³⁺ grating-based fiber laser with 60 mW output power and a net efficiency of 12% is demonstrated     

Resolution of a left ureteral stone using electrohydraulic lithotripsy in a thoroughbred colt

A 3-year-old Thoroughbred colt was presented for evaluation of azotemia and anorexia. Physical examination revealed a ureterolith in the left ureter, approximately 10 cm from the bladder, which was thought to obstruct urine flow by approximately 90% when viewed cystoscopically. Ultrasonographic examination of both kidneys revealed indistinct corticomedullary junctions, and the right kidney was more hyperechoic. A percutaneous biopsy of the right kidney revealed chronic interstitial nephritis with marked interstitial medullary fibrosis. Medical therapy consisting of IV fluids, sodium chloride PO, and ammonium chloride PO was initiated. Ureteroscopic electrohydraulic lithotripsy via a perineal urethrostomy was used to successfully remove the stone. Klebsiella oxytoca, which responded to oral enrofloxacin therapy, was cultured from the urine after surgery. Azotemia resolved and the horse resumed training.     

Light interception, use-efficiency and energy yield of switchgrass (Panicum virgatum L.) grown in a short season area

Switchgrass (Panicum virgatum L.) has been identified as a potential biomass crop in North America. A two-year study was conducted to characterize leaf area development and estimate radiation-use efficiency (RUE) of switchgrass in eastern Canada. Three cultivars, Cave-in-Rock (CIR), Pathfinder (PF) and Sunburst (SB) were grown in solid stands in a randomized complete block design. Dry matter (DM) yield, leaf area development and light interception were monitored bi-weekly throughout the growing season. Herbage subsamples were hand separated into leaf and sheath-stem fractions. Mean seasonal maximum leaf area indices (LAI) were 6.1, 5.3 and 5.1 for CIR, PF and SB, respectively. By early July of each season the canopies were intercepting about 90% of the incoming light. End of season DM yields were 12.2, 11.5 and 10.6 Mg ha⁻¹ for CIR, PF and SB, respectively. The stem plus leaf sheaths constituted the major component of DM and its accumulation trend parallelled that of total DM. End of season stem-sheath components averaged 764, 714 and 691 of the total g kg⁻¹ DM for CIR, PF and SB, respectively. Energy contents of the switchgrasses averaged 17.4 MJ g⁻¹ DM and did not vary among cultivars or during the season. This translated into total energy yields ha⁻¹ of 216 GJ for CIR, 197 for PF and 186 for SB. Radiation-use efficiencies computed using total incoming solar radiation, for the near linear growth phases, averaged 1.07 g DM MJ⁻¹ for CIR, 0.90 for PF and 0.89 for SB. The respective values based on photosynthetically active radiation were 2.20, 2.00 and 1.96 g DM MJ⁻¹. Changes in LAI, relationships between LAI and light interception and DM yield could all be described by predictive regression equations. These results indicate the potential of switchgrass as a biomass crop in short season areas.     

The functional anatomy of sound intensity discrimination

The human neuroanatomical substrate of sound intensity discrimination was investigated by combining psychoacoustics and functional neuroimaging. Seven normal subjects were trained to detect deviant sounds presented with a slightly higher intensity than a standard harmonic sound, using a Go/No Go paradigm. Individual psychometric curves were carefully assessed using a three-step psychoacoustic procedure. Subjects were scanned while passively listening to the standard sound and while discriminating changes in sound intensity at four different performance levels (d' = 1.5, 2.5, 3.5, and 4.5). Analysis of regional cerebral blood flow data outlined activation, during the discrimination conditions, of a right hemispheric frontoparietal network already reported in other studies of selective or sustained attention to sensory input, and in which activity appeared inversely proportional to intensity discriminability. Conversely, a right posterior temporal region included in secondary auditory cortex was activated during discrimination of sound intensity independently of performance level. These findings suggest that discrimination of sound intensity involves two different cortical networks: a supramodal right frontoparietal network responsible for allocation of sensory attentional resources, and a region of secondary auditory cortex specifically involved in sensory computation of sound intensity differences.     

Characterization of the effect of 2-deoxy-D-glucose(2-DG) on the immune system

This study was designed to characterize the effects of the metabolic stress of administration of 2-deoxy-d-glucose (2-DG, 500 mg/kg) on immune function. Male Lewis rats were exposed to one or five injections (one every 48 h) of 2-DG. Control rats received saline injections. Administration of 2-DG induced a reduction of total leukocytes in the spleen, thymus, and blood. The reduction was most prominent in animals that received five injections of 2-DG. The ratio of CD4(+)/CD8(+) in the spleen was decreased due to a significant increase of CD8(+) T-cell subpopulation. Additionally, 2-DG induced a suppression of mitogenic responsiveness and IFN-gamma production in both whole blood and spleen lymphocytes. The production of IL-1 and IL-2 was significantly reduced in the blood, but not in the spleen. Conversely, there was a significant increase in nitric oxide production in cultures of Con A-, PHA-, and LPS-stimulated splenocytes from 2-DG-injected animals compared with saline-injected controls. In blood cultures stimulated with Con A and PHA, the nitric oxide production of the group that received five injections of 2-DG was significantly higher than in the group that received one injection of 2-DG or saline. These results demonstrated that the metabolic stress 2-DG induced a downregulation of Th 1 cellular immune function in a manner similar to physical and psychological stressors. Additionally, the use of 2-DG in rats provided an important model with which to study metabolic stress.     

Recognizing plankton images from the shadow image particle profiling evaluation recorder

We present a system to recognize underwater plankton images from the shadow image particle profiling evaluation recorder (SIPPER). The challenge of the SIPPER image set is that many images do not have clear contours. To address that, shape features that do not heavily depend on contour information were developed. A soft margin support vector machine (SVM) was used as the classifier. We developed a way to assign probability after multiclass SVM classification. Our approach achieved approximately 90% accuracy on a collection of plankton images. On another larger image set containing manually unidentifiable particles, it also provided 75.6% overall accuracy. The proposed approach was statistically significantly more accurate on the two data sets than a C4.5 decision tree and a cascade correlation neural network. The single SVM significantly outperformed ensembles of decision trees created by bagging and random forests on the smaller data set and was slightly better on the other data set. The 15-feature subset produced by our feature selection approach provided slightly better accuracy than using all 29 features. Our probability model gave us a reasonable rejection curve on the larger data set.