Synthetic implants in the reconstruction of the ossicular chain

OBJECTIVE: To determine whether there is a relationship between overexpression of c-met oncoprotein and stage of human gastric mucosal lesions, and its significance. METHOD: Immunohistochemical staining was used in 157 cases of endoscopic biopsies with c-met monoclonal antibody, S-19, which was raised against the human c-met gene product. RESULTS: overexpresion of c-met oncoprotein was detected in 3/30 cases (10%) of superficial gastritis, 4/33 cases (12.1%) of chronic atrophic gastritis, 10/31 cases (32.3%) of intestinal mataplasia, 10/30 cases (33.3%) of dysplasia, and 10/30 cases (33.3%) of gastric carcinoma. The positive staining rate was higher in intestinal mataplasia (54.8%), dysplasia (56.7%), carcinoma (53.3%) than in two kinds of simple chronic gastritis (P < 0.05). The positive staining was obviously located in luminal membrane of mucosal cells. The positive cells were mainly situated in proliferative cell zone of gastric glands. Moreover, the weak staining only in this zone was shown in two of the three normal mucosa. CONCLUSIONS: The overexpression of c-met may be involved in proliferation of gastric mucosa. It is possible that persistent overexpression of c-met oncoprotein is associated with the malignant transformation of gastric mucosal cells.     

Path analysis of aptitude, personality, and achievement scores in Brazilian twins

Achievement at school and performance on the Dominoes test, the Differential Aptitude Tests (DAT), and Griéger's Characterological Questionnaire of 45 monozygotic and 46 same-sex dizygotic pairs of twins were analyzed using a new linear model for familial corrrelation. For 14 of the 20 sets of data, the genotype's contribution to the total variance is estimated to be higher than 50%. The effect of common environment seems to be important only for achievement in Arts.     

Monoamniotic twins diagnosed by ultrasound in the first trimester

A case of monoamniotic twins was diagnosed by ultrasonic scanning in the first trimester through the presence of two fetuses in one gestation sac. The fetuses died in utero in weeks 17 and 25. The possible ultrasound appearance of the various types of monozygotic and of dizygotic twins in early pregnancy is discussed and a scheme is suggested which allows some differentiation.     

Molecular characterization of the di-leucine-based internalization motif of the T cell receptor

Several cell surface receptors including the T cell receptor (TCR) are phosphorylated and down-regulated following activation of protein kinases. We have recently shown that both phosphorylation of Ser-126 and the presence of the di-leucine sequence Leu-131 and Leu-132 in CD3 gamma are required for protein kinase C (PKC)-mediated TCR down-regulation. To identify additional residues required for PKC-mediated phosphorylation of CD3 gamma and for TCR down-regulation, an alanine scanning of CD3 gamma was done. Mutations of Arg-124, Ser-126, Lys-128, and Gln-129 inhibited both phosphorylation and TCR down-regulation, whereas mutation of Asp-127 only inhibited down-regulation. Further analyses demonstrated a discrepancy between the ability to be phosphorylated on CD3 gamma and to down-regulate the TCR in several transfectants. Phosphorylation was not as strictly dependent on the nature and position of the phosphoacceptor group and basic residues as were the subsequent steps involved in TCR down-regulation. Our results suggest that PKC-mediated TCR down-regulation may be regarded as a two-step process. 1) Recognition and phosphorylation of CD3 gamma by PKC. In this process Arg-124, Ser-126, Lys-128, and Gln-129 are important. 2) Recognition of phosphorylated CD3 gamma by molecules involved in receptor internalization. In this process Ser(P)-126, Asp-127, Leu-131, and Leu-132 are important.     

Modeling of primary and secondary dendrites in a Cu-6 Wt Pct Sn alloy

Microstructure of gas-atomized CuSn6 particles has been investigated using scanning electron microscopy (SEM), and it is shown that the dendrite arm spacing (DAS) is related to the particle diameter (d) so that DAS=0.19d ^0.72. Formation of microstructures in the particles are modeled using a numerical solidification model. This model concerns tips of cells and dendrites, but in the present investigation, it is, in a simple manner, extended to comprise whole cells and dendrites. Furthermore, ripening of dendrite arms is taken into consideration. It is found that for increasing growth rates there is a transition from dendrites to cells when the growth velocity approaches the diffusional velocity in the melt,i.e., when the Peclet number is equal to one. It is also shown that both primary stem spacing and dendrite spacing are related to the ratio between the volume in the liquid where there is solute diffusion and to the surface area of the cells and dendrites (D/A). The relation between spacing and D/A is the same for cells and dendrites, indicating that the spacing selection is controlled purely by solute diffusion in the melt.     

Occupational exposures and health among Danish farmers working in swine confinement buildings

In a cross-sectional study at 11 large pig-breeding farms various work-related exposures were measured. The purpose was to record several simultaneous exposures in relation to various work tasks. The concentration of total dust and respirable dust was 4.13 mg/m³ and 0.48 mg/m³ respectively. For all farmers the relative heart rate increase during work was 29% of maximal work capacity (±9.7%), indicating a high work load. Increased pulmonary ventilation causes a higher risk for deposition of dust in the airways. The total tonnage lifted per day was 4,725 kg and was considered to be high according to Danish guidelines. During 40% of the working time, the work was performed with a forward flexion of the back of more than 20°. The load on the back may be the cause of the high one-year prevalence of low back pain at 62%. The work task of feeding pigs was the task with the highest number of simultaneous exposures.