Characterization of tumor-associated neural cell adhesion molecule in human serum

In human serum, at least two molecular species of the neural cell adhesion molecule (NCAM) with molecular weights of 110,000-130,000 and 150,000-180,000, respectively, can be identified by Western blotting. Both are characterized by the absence of epitopes for monoclonal antibodies KD11 and MG5, which specifically recognize intracellular domains of the human NCAM transmembrane isoforms, NCAM-140 and NCAM-180. In contrast to the M(r) 110,000-130,000 molecule also detectable in serum samples from healthy blood donors, the M(r) 150,000-180,000 molecule appears to be tumor associated. The only difference between these two species is shown to be the presence of long chains of alpha-(2,8)-linked N-acetylneuraminic acids, which are characteristic for the so-called embryonic NCAM form. After treatment with endoneuraminidase N, the M(r) 150,000-180,000 molecule can no longer be discriminated from the M(r) 110,000-130,000 molecule in Western blotting as well as gel and anion exchange chromatography experiments. The experimental data clearly show that only the embryonic NCAM molecule carrying the poly-alpha-(2,8)-linked N-acetylneuraminic acid moiety can be regarded as a specific serum marker for small cell lung cancer.     

Purification and molecular cloning of a novel calcium-binding protein, p26olf, in the frog olfactory epithelium

The pharmacological profile and the acute and chronic aquaretic effects of OPC-41061, a novel nonpeptide human arginine vasopressin (AVP) V2-receptor antagonist, were respectively characterized in HeLa cells expressing cloned human AVP receptors and in conscious male rats. OPC-41061 antagonized [3H]-AVP binding to human V2-receptors (Ki = 0.43 +/- 0.06 nM) more potently than AVP (Ki = 0. 78 +/- 0.08 nM) or OPC-31260 (Ki = 9.42 +/- 0.90 nM). OPC-41061 also inhibited [3H]-AVP binding to human V1a-receptors (Ki = 12.3 +/- 0.8 nM) but not to human V1b-receptors, indicating that OPC-41061 was 29 times more selective for V2-receptors than for V1a-receptors. OPC-41061 inhibited cAMP production induced by AVP with no intrinsic agonist activity. In rats, OPC-41061 inhibited [3H]-AVP binding to V1a-receptors (Ki = 325 +/- 41 nM) and V2-receptors (Ki = 1.33 +/- 0. 30 nM), showing higher receptor selectivity (V1a/V2 = 244) than with human receptors. A single oral administration of OPC-41061 in rats clearly produced dose-dependent aquaresis. In treatment by multiple OPC-41061 dosing for 28 days at 1 and 10 mg/kg p.o. in rats, significant aquaretic effects were seen throughout the study period. As the result of aquaresis, hemoconcentration was seen at 4 hr postdosing although, no differences were seen in serum osmolality, sodium, creatinine and urea nitrogen concentrations at 24 hr postdosing. Furthermore, there was no difference in serum AVP concentration, pituitary AVP content or the number and affinity of AVP receptors in the kidney and liver at trough throughout the study period. These results demonstrate that OPC-41061 is a highly potent human AVP V2-receptor antagonist and produces clear aquaresis after single and multiple dosing, suggesting the usefulness in the treatment of various water retaining states.     

Serum insulin-like growth factor-I, insulin-like growth factor binding protein-3, sex steroids, osteocalcin and bone mineral density in male and female rats

Although it has been reported that the rate of weight gain and linear growth increases markedly during puberty in rats, little is known about the relationship between endocrine changes and bone mineral density (BMD) changes upon sexual maturation in these animals. The aim of this study was to examine the levels of serum insulin-like growth factor-I (IGF-I), IGF binding protein (IGFBP)-3, sex steroids and osteocalcin, and the changes in BMD in normal aging male and female rats. Male rats exhibited increases in serum IGF-I and IGFBP-3 concentrations before increases in serum testosterone levels. IGF-I and testosterone peaked at 9 weeks of age, and thereafter remained in a steady state, whereas IGFBP-3 reached a peak at 7 weeks of age, and then gradually declined. A strong correlation between serum IGF-I and IGFBP-3 levels was found in subjects 3-9 weeks old. A highly significant correlation between serum IGF-I and testosterone levels was also found. In females, serum 17 beta-estradiol, IGF-I and IGFBP-3 levels increased gradually from 3 to 5 weeks old, peaked at 9 weeks, and then decreased slowly thereafter. The correlation coefficient between serum IGF-I and IGFBP-3 was highly significant. The correlation coefficient between serum IGF-I and 17 beta-estradiol levels was weak, although it was strongest when the subjects were 3-9 weeks old. Serum osteocalcin is a marker of bone formation; its level remained relatively high from 3 to 9 and from 3 to 7 weeks of age in males and females, respectively, although osteocalcin in both sexes declined gradually with age. As for bone mass, sharp increases in BMD in the tibia, femur and lumbar vertebrae appeared earlier in female than in male rats, and the BMD in females tended to be higher than in males between 5 and 9 weeks old. After 9 weeks of age, BMD in males was higher than that in females, as BMD in males continued to increase whereas females tended to remain in a steady state after this stage. The correlation coefficients between tibial BMD and serum IGF-I or IGFBP-3 levels were highly significant when the subjects were from 3 to 9 weeks old. Taken together, these results suggest that BMD development occurs earlier in female than in male rats. This sex-related difference in changes in the BMD pattern may result from the earlier onset of puberty in females, and from sex-specific differences in concentrations of IGF-I, IGFBP-3 and sex steroids during maturation.     

A novel nonsense mutation associated with an exon skipping in a patient with hereditary protein S deficiency type I

The genetic defect in a patient with hereditary type I protein S (PS) deficiency was investigated. All the exons and intron-exon junctions of the patient's PS gene were amplified by PCR and subjected to heteroduplex screening. Only the PCR product of exon 4 revealed heteroduplex bands. A novel nonsense mutation, Ser62 (TCA) to Stop (TGA) was found in exon 4. RT-PCR detected the aberrant mRNA in the patient's platelets, which was markedly reduced in amount and lacked the region of exon 4, suggesting that the nonsense mutation affected the mutated mRNA metabolism and induced exon skipping. The skipping of exon 4 causes an in-frame deletion of 29 amino acids which just construct the thrombin-sensitive region of the PS molecule. The loss of such an important domain as well as the quantitative decrease in the mutated mRNA appear to be responsible for the type I PS deficiency in this patient.     

Large aperture superconducting magnet (benkei)

Benkei, which was a large window frame conventional magnet at KEK has been converted to a superconducting magnet. In the conversion, the pole gap has been doubled from 0.5 m to 1.0 m retaining an analysing power at 2 T m. Several new techniques were applied to coil windings and cryostat fabrication. The superconducting Benkei has shown satisfactory performances for long term operation.     

Transcription factor E2F controls the reversible gamma delta T cell growth arrest mediated through WC1

IL-2-stimulated expansion of T cells requires continued and sequential passage of the dividing cells through a major cell cycle check point in the G1 phase. We have previously shown that a gamma delta T cell-specific surface receptor, WC1, induces G0/G1 growth arrest, reversible with Con A, in proliferating IL-2-dependent gamma delta T cells. We now show that this reversible WC1-induced cell cycle arrest is correlated with induction of the cyclin kinase inhibitor p27kip1 and an associated down-regulation in cyclins A, D2, and D3 expression, along with dephosphorylation of pocket proteins p107, p130, and pRb. Together with diminished pocket protein phosphorylation, p107 expression levels are significantly down-regulated in response to WC1 stimulation. This coordinated sequence of signaling events is focused on E2F regulation so that, downstream of the pocket proteins, WC1 stimulation results in a diminished DNA binding activity for free E2F as a consequence of reduced E2F1 expression, whereas E2F4 expression is unaffected. Consistent with this interpretation, overexpression of E2F1 overcomes the growth-arresting effects induced by WC1 stimulation. Finally, in accordance with our previous observations at both the cellular and molecular level, subsequent mitogen stimulation can reverse all the above changes induced by WC1. These results, focused on E2F regulation, therefore provide a first insight into the effects of both positive (mitogen) and negative (anti-WC1) stimuli on cell cycle control in IL-2-dependent gamma delta T cells.     

Simplified stable crack growth analyses of welded CT specimens—comparison study of GE/EPRI, reference stress and R6 methods

This paper describes some simplified stable crack growth analyses of two kinds of inhomogeneous CT specimens. The one is machined from a submerged are welded plate of a nuclear pressure vessel A533B Class 1 steel, while the other is machined from an electron-beam welded plate of the A533B Class 1 steel and a high strength HT80 steel. In both specimens, initial cracks are placed to be normal to the fusion line. The ratio of yield stresses of the weld metal and the base metal of the A533B Class 1 steel is about 1·15, while that of the HT80 and the A533B Class 1 steels is about 1·4.

The generation phase crack growth analyses using the GE/EPRI and the reference stress methods are performed, calculating an applied load (P) and the J-value, while the application phase analyses of analyses using the R6 method are performed to calculate the maximum value of the applied load (P_max). Finally, some modification procedures of the three simplified estimation schemes are discussed in order to apply them to inhomogeneous material regimes.     

The utility of three-phase bone scintigraphy in the assessment of fractured carpal scaphoid

Thirty-seven joints in 36 patients with a fractured carpal scaphoid were evaluated by three-phase bone scintigraphy. They were classified into two groups according to their progress. Some were in good clinical condition and some in a non-union condition. Increased blood flow in the radial arteries and ample perfusion on and around the scaphoid bones on blood flow images suggested a good clinical course. The activity and the effectiveness of remodeling correlated well with the degree of scaphoid uptake on blood pool images taken more than seven days after the injury. Scaphoid uptake was more localized or there was almost none on blood pool images in cases with nearly complete recovery while it was amply visualized on static images. Blood pool images were indispensable for analyzing lesions and evaluating the clinical course. Two typical findings of scaphoid fractures were found on both blood pool and static images. One was diffusely increased scaphoid uptake seen in cases with a good clinical course, and the other was decreased uptake at proximal fragments seen in cases with non-union. It is concluded that three-phase bone scintigraphy provides useful information for evaluating the process of scaphoid fractures which cannot be obtained by means of conventional bone scintigraphy.     

Surgical therapy in a case of congenital mitral valve insufficiency]

Using sheep erythrocytes (SRBC) as the antigen, two subpopulations of spleen antigen-binding lymphocytes could be distinguished by a marked difference in the susceptibility of their receptors to trypsin. In unimmunized animals, 30% of the antigen-binding cells were trypsin-resistant, whereas at 5 days after immunization, 80-90% were trypsin-resistant, indicating an increase of about 50-fold in trypsin-resistant antigen-binding cells per spleen. In contrast, trypsin-sensitive cells per spleen were only 4-fold higher on day 5 than before immunization. The rise in % trypsin sensitivity preceded the increase in rosettes per spleen, implying that immunization produced a preferential increase in trypsin-resistant antigen binding cells partly by converting sensitive cells to resistant cells. After the 5th day, the trypsin sensitivity of antigen-binding cells slowly returned toward the unimmunized level, but a booster injection of SRBC restored trypsin resistance. Trypsin resistance was not lost in the presence of sodium azide or protein synthesis inhibitors. But a slightly increased trypsin susceptibility was conferred by 2-deoxyglucose, implying that glycolysis or the glycosylation of protein may be involved in maintaining trypsin resistance.