Vitelline cell development in monogenean parasites

Summary Histochemical and electron microscopic studies of the vitellaria of three polyopisthocotylean fish-gill flukes,Diplozoon paradoxum, Diclidophora merlangi andD. denticulata, and one monopisthocotylean fish-skin fluke,Calicotyle kröyeri have shown that, in each case, vitelline cell development is basically similar. Immature vitelline cells are typically embryonic and undifferentiated. InD. paradoxum they display annulate lamellae, and inC. kröyeri they are invested with flat, sheet-like extensions of the parenchyma. Differentiation into maturing vitelline cells involves the development of extensive GER, Golgi complexes and the production of dense droplets of shell-protein. With the onset of maturity, protein synthesis stops and, as the GER disintegrates, the cell develops food-reserves in the form of yolk bodies, glycogen and lipid. It is then released into the vitelline ductlet. These processes occur in all the follicles at the same time, and all stages of development can be found in any one follicle.     

Kr-81m ventilation imaging: clinical utility in suspected pulmonary embolism

The results of Kr-81m/Tc-99m ventilation-perfusion (VP) lung scintigraphy were correlated with the results of pulmonary angiography for 74 patients suspected of having pulmonary embolism (PE). Among patients having a diagnostic scan, the sensitivity and specificity of scintigraphy were 91% and 94%, respectively. Also, 157 consecutive cases of Kr-81m/Tc-99m VP lung scintigraphy were reviewed, and the frequency of an indeterminate scan was found to be 22%. A similar frequency was found for VP scintigraphy with xenon-133. Of eight patients who had indeterminate scans due to the presence of a single VP mismatch, four were demonstrated to have PE by angiography. Kr-81m is an excellent agent for VP scanning in cases of suspected PE, offering accuracy in diagnosis as well as favorable physical properties.     

Studies of glycine metabolism and transport in fibroblasts from patients with nonketotic hyperglycinemia

Glycine transport in both normal and nonketotic hyperglycinemia fibroblasts was shown to occur by a sodium-dependent system. No significant difference could be detected in either the Km's (1.4 to 2.0 mM) or the Vmax's (6.2 to 16 nmole per mg protein per min) of the three control and three patient cell lines. Valine was a weak competitive inhibitor of glycine uptake. Ki's from both groups fell into the 5.6 to 5.8 mM range. Plasma levels of valine of one patient reached a maximum of 0.6 mM following a valine load. Glycine cleavage activity could not be detected in either control or nonketotic hyperglycinemia fibroblast lines. Serine utilization was the same in both nonketotic hyperglycinemia and control lines.     

Ocular MR imaging and spectroscopy: an ex vivo study

Six eyes, freshly enucleated because of choroidal melanoma, were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system, and relaxation times were calculated for various parts of the eye. Unfixed fresh tissue samples were obtained for nuclear magnetic resonance spectroscopy (NMRS) on a variable-field (0.19-1.4 T) resistive unit. Detailed ocular anatomy was demonstrated. The NMRS relaxation times correlated with the MR imaging intensity patterns. The sensitivity of MR imaging to states of hydration provides an excellent window for appreciation of ocular anatomy.     

Association of achalasia and pulmonary Mycobacterium fortuitum infection

A case of achalasia complicated by Mycobacterium fortuitum pulmonary infection and empyema is reported. This association has been documented in the medical literature. Possible mechanisms explaining this association are discussed.