The localization of aldosterone-producing adenoma on computed tomography--a comparative study with adrenal scintigraphy and plasma aldosterone concentration in the adrenal or renal vein

The evaluation of computed tomography (CT) for detecting aldosterone-producing adenoma in primary aldosteronism was performed by comparison with adrenal scintiscan; determination of aldosterone in adrenal or renal veins, retroperitoneal pneumography and adrenal venography was reliable for diagnosis of adrenal tumors in pheochromocytoma or Cushing's syndrome, but not so effective for small adenoma of primary aldosteronism. An abdominal CT scan was performed on six patients with primary aldosteronism, one with idiopathic hyperaldosteronism and one with glucocorticoid responsive hyperaldosteronism; in an attempt to evaluate the utility of this noninvasive procedure. Diagnosis of hyperaldosteronism was made by demonstrating the elevated plasma aldosterone concentration and aldosterone secretion rate, normal excretion rate of urinary 17-OHCS and 17-KS, and low plasma renin activity. The CT scan correctly predicted unilateral adrenal adenoma in all the patients with primary aldosteronism of which the findings were identical to those demonstrated by surgery. The diameter of these tumors ranged from 10 X 7 X 6 to 19 X 17 X 14 mm. Also the CT scan in idiopathic hyperaldosteronism and glucocorticoid responsive hyperaldosteronism showed bilateral adrenal hyperplasia and bilateral normal adrenal glands, respectively. The pathological findings in these two cases disclosed the adrenal hyperplasia of zona glomerulosa and adrenal hyperplasia of zona subglomerulosa accompanied by a normal thickness of the adrenal gland, respectively. The precision of the CT scan, adrenal scintigraphy and determination of plasma aldosterone in the adrenal or renal veins were almost equal to the diagnosis of the localization of adrenal adenoma. It is concluded that the CT scan is a noninvasive and most useful method for the localization of aldosterone-producing adenoma and helpful in distinguishing adrenal adenoma from adrenal hyperplasia.     

X-ray study of pre-treated regenerated cellulose fibres

Regenerated cellulose fibres have had an important role to play in the man-made fibre field. The very special characteristics of different types of regenerated cellulose fibres, e.g. mechanical properties, sorption characteristics, and aesthetics were conditioned by the differences in their fine structure due to fibre formation processes. Additionally, the finishing processes could influence the fibre structure. A study was done of the crystalline structures of a solvent-spun cellulose fibre type (Lenzing Lyocell), made according to the NMMO process, and two conventional cellulosic fibre types, made by the viscose process (Lenzing Viscose and Lenzing Modal). The fibres were pre-treated (bleached and slack mercerised) and structural changes were followed by wide angle and small angle x-ray scattering (WAXS and SAXS), respectively. The periodical structure, determined by long spacing, was nearly the same in all the different types of fibres. A slight increase was observed after the treatment of viscose and modal fibres, but an unpronounced fall of a long period accompanied the pre-treatment of lyocell fibres. Some changes in crystallinity and crystalline orientation occurred due to the treatment conditions. The structural changes were correlated to the iodinesorption and mechanical properties.     

The Significance of Surface Charge and Structure on the Accessibility of Cellulose Fibres

The electrokinetic properties of macroscopic solids can describe both the surface modifications as well as the interaction abilities during processing. Normally the zeta potential (ζ) is measured and can be used to develop, optimise and control the manufacturing process. The zeta potential of natural and regenerated cellulose fibres changes noticeably during the pre‐treatment and finishing process and it is important for the quality of the final product (whiteness, colour, hydrophilicity). The pre‐treatment of cellulose fibres improves the accessibility of dissociable groups. Further improvement of hydrophilicity (mercerisation) causes a pronounced increase in the surface charge density and a reduction in the degree of crystallinity and structural modifications. The progress of the chemical as well as the enzymatic treatment correlates with ζ. These data correlate very well with the results obtained using tensiometry, water retention, and water vapour and iodine adsorption. The changes in crystallinity index and the accessibility for low molecular components are well described by the latter methods.     

Molecular orientation and structural development in vulcanized polyisoprene rubbers during uniaxial deformation by in situ synchrotron X-ray diffraction

Molecular orientation and strain-induced crystallization of vulcanized natural rubbers (by sulfur and peroxide) and synthetic polyisoprene rubber (by sulfur) during uniaxial deformation at 0 °C were studied by in situ synchrotron wide-angle X-ray diffraction. The high intensity of synchrotron X-rays and new image analysis methods made it possible to estimate the mass fractions of strain-induced crystals and amorphous chains in both oriented and unoriented states. Most of the polymer chains (∼75%) were found to be in the random coil state even at large strains (>5.0). Only about 5% the amorphous chains were oriented, whereas the rest of the chains (∼20%) were in the crystalline phase. Sulfur vulcanized and peroxide vulcanized natural rubbers did not exhibit notable differences in structure and property relationships. In contrast, synthetic polyisoprene rubber showed a different behavior of deformation-induced structural changes, which can be attributed to the difference in cross-link topology. Our results indicated that strain induces a network of microfibrillar crystals in both natural and synthetic polyisoprene rubbers due to the inhomogeneity of cross-link distribution that is responsible for their elastic properties.     

Protective effects of granulocyte colony-stimulating factor on endotoxin shock in mice with retrovirus-induced immunodeficiency syndrome

Mice with retrovirus-induced murine acquired immunodeficiency syndrome (MAIDS) were hypersensitive to lipopolysaccharide (LPS)-induced lethal shock accompanied by marked elevations of systematic interleukin 1beta (IL-beta) and interferon gamma (IFN-gamma) after LPS challenge. Pretreatment with 10 microg of recombinant human granulocyte colony-stimulating factor (rhG-CSF) protected MAIDS mice from hypersensitivity to LPS-induced lethal shock and this protection was concomitant with suppression of IFN-gamma production.     

In situ WAXD study of structure changes during uniaxial deformation of ethylene-based semicrystalline ethylene-propylene copolymer

In situ strain-induced structure changes during uniaxial deformation of an ethylene-propylene copolymer, containing 78 wt% (or 85 mol%) of ethylene moiety, were studied by synchrotron wide-angle X-ray diffraction (WAXD). The chosen sample could crystallize into orthorhombic, pseudo hexagonal or a mixed form, depending on the annealing conditions. Crystallization at high temperatures (e.g. 50 °C) favored the formation of orthorhombic form, while crystallization at low temperatures (e.g. 20 °C) favored the formation of pseudo hexagonal form. Under deformation, the transition from orthorhombic to pseudo hexagonal form was observed at relatively low strains (e.g. 0.12). At higher strains, WAXD data indicated the occurrence of direction-dependent crystal destruction at strains <0.25 and subsequent re-crystallization with extended-chain conformation at high strains (>1.0) all of the pseudo hexagonal form. The drastic changes in the crystalline structures (orthorhombic to pseudo hexagonal) and phase transitions (crystal destruction and re-crystallization) at modest strains can be attributed to the high mobility of the amorphous ethylene-propylene segments at room temperature.     

Induction of c-kit molecules on human CD34+/c-kit < low cells: evidence for CD34+/c-kit < low cells as primitive hematopoietic stem cells

c-kit, a receptor for stem cell factor, has been widely accepted as a distinctive marker for hematopoietic stem cells. However, the level of c-kit expression on pluripotent hematopoietic stem cells is still controversial in mice and humans. We purified CD34+/c-kit < low cells (phenotypically c-kit-negative but only detectable at the message level) from human cord blood and examined their maturational steps in relation to the expression of c-kit molecules. When the CD34+/c-kit < low cells were cultured with cytokines (flt 3 ligand, interleukin 6 and interleukin 7) plus immobilized anti-CD34 monoclonal antibody (to crosslink CD34 molecules), c-kit molecules were clearly induced within 24 h. The c-kit expression gradually increased until day 8. When CD34+/c-kit(low) or CD34+/c-kit+ cells that had been induced from CD34+/c-kit < low cells were resorted and recultured using a methylcellulose culture system, they showed the same colony-forming ability as the freshly isolated CD34+/c-kit(low) or CD34+/c-kit+ cells, respectively. Furthermore, CD34+/c-kit < low cells have a similar hematopoietic potential to CD34+/c-kit(low) cells in assays for long-term culture initiating cell and colony-forming unit culture generated from long-term cultures. These findings suggest that CD34+/c-kit < low cells mature into CD34+/c-kit(low) and CD34+/c-kit+ cells, and acquire the reactivity to various humoral hematopoietic stimuli. Moreover, CD34+/c-kit < low cells showed a low level of rhodamine 123 retention, suggesting that CD34+/c-kit < low cells have multidrug resistance. Therefore, the CD34+/c-kit < low cells without colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte activity are also a pluripotent hematopoietic stem cell population, and the expression of c-kit on c-kit < low cells is the first maturational step of hematopoiesis.     

Immunohistochemical distribution of surfactant apoproteins in hypoplastic lungs of nonimmunologic hydrops fetalis

Forty-three patients with nonimmunologic hydrops fetalis (NIHF), including 32 patients (74%) with hypoplastic lung, were immunohistochemically examined for the expression of surfactant apolipoproteins (SPs), using anti-gamma G immunoglobulins against human SP-A with a molecular weight (MW) of 35 K and SP-B with a MW of 5 K compared with that in 59 patients in a control group and 45 patients with hypoplastic lung induced by causes other than NIHF. In the control group, SP-A was expressed in the lungs from 23 gestational weeks and became more numerous and intense in alveolar type II cells after 31 gestational weeks, whereas SP-B began to be expressed from 20 gestational weeks, and almost all patients showed a diffuse positivity after 26 gestational weeks. In the NIHF group, SP-A expression was generally weak, even after 31 gestation weeks. Moreover, most of the patients showing a weak expression of SP-A were also associated with hypoplastic lung and had a clinical history of persistent intrauterine pleural effusion of more than 2 weeks. Conversely, the immunoreactivity of SP-B was well preserved in NIHF cases either with or without hypoplastic lung. These results suggest that in the NIHF lung, there is a possible delay in the functional maturation or development of SP-A synthesis by alveolar type II cells, and this retardation of the functional maturation in type II cells also participates in the postnatal respiratory insufficiency in NIHF.