Sonographic differentiation of asymptomatic diffuse thyroid disease from normal thyroid: a prospective study.

BACKGROUND AND PURPOSE: There is no useful guide or study related to the differentiation of asymptomatic diffuse thyroid disease from normal thyroid by using thyroid US. This study was prospectively designed to evaluate the efficacy of the use of real-time thyroid sonography as performed by an experienced radiologist for the identification of asymptomatic DTD. MATERIALS AND METHODS: From January 2008 to December 2008, 2267 patients underwent thyroid sonography in our hospital by 1 radiologist. Each patient's thyroid was prospectively classified as being in 1 of 4 of the following diagnostic categories on the basis of the sonographic features as determined with the use of real-time sonography: suggestive for DTD, suspicious for DTD, indeterminate, and no evidence of DTD. We calculated the diagnostic efficacy of the sonographic classifications compared with the pathology results. RESULTS: Sonographic classifications for DTD in 340 patients who underwent thyroid surgery because of thyroid malignancy or other causes included the following: suggestive for DTD (n = 32), suspicious for DTD (n = 39), indeterminate (n = 18), and no evidence of DTD (n = 251). On the pathology, HT (n = 33), chronic lymphocytic thyroiditis (n = 27), diffuse hyperplasia (n = 2), and NTP (n = 278) were identified. There were true-positive cases (n = 50), true-negative cases (n = 244), false-positive cases (n = 21), and false-negative cases (n = 7). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for a diagnosis of asymptomatic DTD were 87.7%, 92.1%, 70.4%, 97.2%and 91.3%, respectively. CONCLUSIONS: The present sonographic classification based on real-time sonography of the thyroid is a useful tool for differentiating asymptomatic DTD from normal thyroid.

Exploring microdischarges for portable sensing applications.

This paper describes the use of microdischarges as transducing elements in sensors and detectors. Chemical and physical sensing of gases, chemical sensing of liquids, and radiation detection are described. These applications are explored from the perspective of their use in portable microsystems, with emphasis on compactness, power consumption, the ability to operate at or near atmospheric pressure (to reduce pumping challenges), and the ability to operate in an air ambient (to reduce the need for reservoirs of carrier gases). Manufacturing methods and performance results are described for selected examples.

The study of cerebral hemodynamics in the hyperacute stage of fat embolism induced by triolein emulsion.

PURPOSE: The purpose of this study was to evaluate the cerebral hemodynamic change in the hyperacute stage of cerebral fat embolism induced by triolein emulsion, by using MR perfusion imaging in cat brains. METHODS: By using the femoral arterial approach, the internal carotid arteries of 14 cats were infused with an emulsion of triolein 0.05 mL. T2-weighted (T2WI), diffusion-weighted (DWI), apparent diffusion coefficient (ADC) map, perfusion-weighted (PWI), and gadolinium-enhanced T1-weighted (Gd-T1WI) images were obtained serially at 30 minutes and 2, 4, and 6 hours after infusion. The MR images were evaluated qualitatively and quantitatively. Qualitative evaluation was performed by assessing the signal intensity of the serial MR images. Quantitative assessment was performed by comparing the signal-intensity ratio (SIR) of the lesions to the contralateral normal side calculated on T2WIs, Gd-T1WIs, DWIs, and ADC maps at each acquisition time and by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (CBF), and mean transit times (MTT) of the lesions to the contralateral normal side calculated on PWI. RESULTS: In the qualitative evaluation of the MR images, the lesions showed hyperintensity on T2WIs, enhancement on the Gd-T1WIs, and isointensity on DWIs and the ADC maps. In the quantitative studies, SIRs on the Gd-T1WIs, DWIs, and ADC maps peaked at 2 hours after infusion. The SIRs on the T2WIs peaked at 4 hours after infusion and decreased thereafter. On PWIs, the rCBV, rCBF, and MTT of the lesion showed no significant difference from the contralateral normal side (P = .09, .30, and .13, respectively) and showed no significant change of time course (P = .17, .31, and .66, respectively). CONCLUSION: The embolized lesions induced by triolein emulsion showed no significant difference in cerebral hemodynamic parameters from those on the contralateral normal side. The result may suggest that consideration of the hemodynamic factor of embolized lesions is not necessary in further studies of the blood-brain barrier with triolein emulsion.

Immunochemical identification of the chick HPRT gene transferred from chick erythrocytes to mammalian somatic cells.

Immunochemical methods were used to identify the genetic origin of hypoxanthine phosphoribosyltransferase (HPRT) expressed in heteroploid, HPRT-deficient mouse (A9) cells and Chinese hamster ovary (K627) cells, after these cells were fused with chick embryo erythrocytes and selected for resistance to hypoxanthine-aminopterin-thymidine (HAT) medium. All of the HAT-selected clones produced HPRT activity which was immunoprecipitable by an antiserum specific for chick HPRT, but not by an antiserum specific for mouse and hamster HPRT. Furthermore, the HPRT activity in these clones was electrophoretically indistinguishable from chick liver HPRT and clearly different from mouse liver HPRT. These data provide evidence that the HPRT activity expressed in cell hybrids produced by the fusion of HPRT-negative mammalian cells and chick erythrocytes containing genetically inactive nuclei is indeed coded by the chick HPRT gene and that an avian gene can be stably incorporated and correctly expressed in a mammalian cells.

Human chromosome 11 affects the expression of fibronectin fibers in human x mouse cell hybrids.

Synteny between fibronectin (FN) production and human chromosome 11 was established in cell hybrids of FN-producing embryonic diploid fibroblasts and non-producing heteroploid mouse A9 cells. Because the FN antiserum used reacts with both human and mouse FN, it is not clear if the human 11 carries structural or regulatory information for FN production or information that influences FN expression in some other way. In different human x mouse systems, Owerback et al. (1978) found synteny between chromosome 8 and FN, and Smith et al. (1979) with 3 and 11. The latter authors suggest that chromosome 3 controls expression and that the 11 has the structural gene. The humans 3 and 8 were eliminated as necessary for FN production in the hybrids of this study. Since different cell hybrids and FN assay methods were used in the three studies, and the species specificity of some of these assays has not been established, it is not clear if severao play a role in differentiation, development, and possibly also in tumorigenicity.

Renal CO2 production from glutamine and lactate as a function of arterial perfusion pressure in dog.

The energy cost of renal function in the intact kidney of the dog was assessed at a series of arterial perfusion pressures. Pressure was varied by partially inflating a balloon at the tip of a catheter positioned in the aorta above the origins of the renal arteries. Either L-[U-14C]-lactate was infused intravenously in tracer amounts throughout each experiment. Total renal CO2 production and 14CO2 production from each isotope permitted assessment of total renal oxidative metabolism and the proportions derived from the two major substrates of the kidney. Stepwise inflation of the aortic balloon progressively lowered glomerular filtration rate, renal blood inflow, filtered and consequently reabsorbed Na+, total renal CO2 production, and 14CO2 derived from glutamine and lactate. The percent of total CO2 derived from lactate decreased more or less in proportion to the decrease in percent of total CO2 produced. Results were consistent with the view that reabsorption of sodium is the major energy sink of the kidney. They suggest that the oxidation of glutamine supplies energy for tubular transport and basal demands such as synthesis of hormones and maintenance of structure, whereas the oxidation of lactate supplies energy mainly for transport activities.

Renal metabolism of citrate.

Our studies on renal handling of citrate have shown that: (1) citrate enters renal tubular cells from luminal fluid (reabsorption) and peritubular blood; (2) reabsorption becomes maximal, i.e., Tm-limited, at filtered loads 7 to 8 times the normal; (3) administration of malate stimulates net renal production of citrate, leading to release into urine (net secretion) and into peritubular blood; (4) acute metabolic alkalosis, induced while plasma citrate levels are above normal, depressess net citrate reabsorption, stimulates citrate release into peritubular blood and abolishes overall renal uptake of citrate; (5) essentially all citrate extracted by the kidney is converted to CO2 at endogenous circulating levels. This contribution is 15 per cent of the total renal CO2 production and is independent of chronic alterations in acid-base balance.