Distinction between suppressors of the delayed-type hypersensitivity and the humoral response to sheep erythrocytes.

Suppressors for both delayed-type hypersensitivity (DTH) and the humoral immune response could be simultaneously induced in the spleens of mice by immunization with a high dose of SRBC. Normal recipient mice of the spleen cells from donors immunized 5 days previously elicited depressed DTH or humoral response when immunized with SRBC. The suppressive activity was found to reside in T not B enriched fraction. Four hundred rad irradiation of the primed spleen cells resulted in complete loss of DTH suppressor activity, but only in some reduction of the suppressor activity for the humoral response. In contrast, hydrocortisone treatment of the donor mice caused no loss of DTH suppressor activity while approximately half of the suppressive activity for anti-SRBC PFC response was lost. Adult thymectomy prevented completely the induction of the DTH suppressor in contrast to little loss of the suppressor activity for the humoral response. DTH suppression was antigen-specific for the induction, but nonspecific for the expression. However the suppression of the humoral response was antigen-specific not only for the induction but also for the expression. In addition, DTH suppressor was capable of suppressing both the induction and expression of DTH while the humoral response was suppressed only in the induction stage by the suppressor.     

Reconstitution of a functional interleukin (IL)-7 receptor demonstrates that the IL-2 receptor γ chain is required for IL-7 signal transduction

The interleukin (IL)-2 receptor γ chain has recently been shown to be a component of the IL-7 and IL-4 receptors. Using a transient transfection assay and the trans-activation of reporter gene constructs which are under the control of cytokine-responsive promoter elements, we have studied signal transduction through the IL-7 receptor (IL-7R). The reporter gene expression was not stimulated by receptors that contained the cytoplasmic domain of the IL-7R, either as intact IL-7R or as part of a chimeric receptor. However, co-expression of the IL-7R with the IL-2 receptor γ chain was able to stimulate gene activation. For maximal stimulation the intact cytoplasmic domains of each chain was required.     

Murine interleukin 5 receptor isolated by immunoaffinity chromatography: comparison of determined N-terminal sequence and deduced primary sequence from cDNA and implication of a role of the intracytoplasmic domain

The murine interleukin 5 receptor (IL-5R) was identified by utilizing an immobilized IL-5 and an immobilized monoclonal antibody against the murein IL-5R (designated H7 mAb). The H7 mAb immunoaffinity-purified materials from the extract of cell-surface radioiodinated T88-M cells (an IL-5-dependent early B cell line) using 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) were reacted with an immobilized IL-5 matrix. SDS-PAGE of the adsorbed fraction revealed a single band at approximately 60 kDa. The binding of the 60 kDa protein to the immobilized IL-5 matrix was inhibited by the excess IL-5. The CHAPS-extract depleted of the 60 kDa protein by the absorption with H7 mAb did not contain any IL-5 binding proteins. Immunoaffinity procedure provided a final 7400-fold purification, based on an estimation of the content of the 60 kDa protein (approximate purity: 20%) from the silver-stained pattern of SDS-PAGE. Actin was copurified with the 60 kDa protein at an approximate ratio of 1:1, suggesting that the intracytoplasmic domain of the IL-5R may interact with actin. Furthermore, soluble IL-5R (molecular mass: 50 kDa) was purified by the H7 mAb-immunoaffinity chromatography. The purified soluble IL-5R was capable of inhibiting the binding of IL-5 to T88-M cells. Preparative SDS-PAGE followed by electroblotting onto a membrane permitted the determination of the N-terminal sequence of the IL-5R. The determined N-terminal sequence of the IL-5R and the deduced primary sequence from recently isolated cDNA were compared.     

Genetic polymorphisms of orosomucoid and alpha-2-HS-glycoprotein in Thai,Sri Lankan and Paraguayan populations

The genetic polymorphism of orosomucoid (ORM) and alpha-2-HS-glycoprotein (AHSG) were studied in Thai, Sri Lankan and Paraguayan populations using isoelectric focusing. Gene frequencies in these populations were compared with those in other populations. Four new ORM variants were detected:ORM1 ^* 15 in Thai,ORM1 ^* 16 in Paraguayan,ORM2 ^* 21 andORM2 ^* 22 in Sri Lankan.     

A comparison of three bioelectrical impedance analyses for predicting lean body mass in a population with a large difference in muscularity

This study tested the hypothesis that, as compared to whole-body bioelectrical impedance (BI) analysis, segmental BI analysis can estimate lean body mass (LBM) more accurately in a population with a large difference in muscularity. In addition to whole-body BI, which determines impedance (Z) between the wrist and ankle, two segmental BI analyses which determine the Z value of every body segment in each of (1) the arms, legs and trunk (distal BI) and (2) the upper arms, upper legs and trunk (proximal BI) were applied to a group of 125 male athletes and 75 non-athletes. The subjects were divided into validation and cross-validation groups. Simple and multiple regression analyses were applied to (length)²/Z (BI index) values for the whole-body and each body segment, to develop the prediction equations of LBM measured using air-displacement plethysmography. In the validation group, the SE of estimation was similar in the whole-body (3.4 kg, 5.4%), distal (3.4 kg, 5.5%) and proximal BI (3.3 kg, 5.2%) analyses. However, the whole-body and distal BI analyses produced systematical errors in the estimates of LBM. Moreover, the residuals in the two methods significantly (P<0.05) correlated with the ratios of BI indices of the upper arms and upper legs to those of the arms and legs, respectively, calculated as variables approximating the relative development of lean tissues at the proximal area of limbs. On the other hand, the proximal BI analysis was validated and cross-validated. Thus, the accuracy of estimating LBM was similar in the whole-body and the two segmental BI analyses. However, the prediction equations derived from the use of the whole-body BI index and a combination of the arms, legs and trunk BI indices produced a systematical error relating to the difference between the limb segments in lean tissue development.     

Induction of brain tumors by a newly isolated JC virus (Tokyo-1 strain).

A newly isolated virus from a patient with progressive multifocal leukoencephalopathy (PML) (Tokyo-1 strain) was found serologically identical to JC virus (Mad-1 strain) and showed high neurooncogenicity in hamsters. Twenty-one animals inoculated intracerebrally with the virus developed brain tumors during a period that averaged 5 months. The tumors were cerebellar medulloblastoma (n = 20); plexus tumor (n = 2) occurred in 1 animal as a single tumor and in another in combination with a medulloblastoma. Thalamic gliomatosis was also present in 6 animals with medulloblastoma. Five mock-infected animals did not develop tumors. Medulloblastoma cells were shown to contain papovavirus T-antigen. In 20 animals examined the medulloblastoma showed a close resemblance to the human medulloblastoma in its histologic, immunocytochemical, and ultrastructural features. Examination of the incipient tumors indicated that the hamster medulloblastoma originated in cells in the neonatal external granular layer. Following infection the cells apparently migrated into the internal granular layer, carrying integrated virus genes and expressing phenotypical transformation. These findings confirm previous reports on the oncogenicity of virus isolates from PML (ZuRhein and Varakis, 1979), but are novel in that with this new isolate tumors could be induced with comparatively low levels of virus inocula.     

Axonal projection of descending pathways responsible for eliciting forelimb stepping into the cat cervical spinal cord

Summary The descending pathways responsible for eliciting forelimb stepping are located in the lateral funiculus (Yamaguchi 1986). In order to determine into which spinal segments the descending pathways project and to know the projections and functions of the other descending system, the ventral funicular pathways, we placed various lesions in the cervical spinal cord of decerebrate cats with the lower thoracic cord transected and studied their effects on forelimb stepping evoked by stimulation of the midbrain locomotor region. (1) The lateral funiculus was transected on one side. The operation removes descending input to all the segments caudal to the lesion. Experiments with serial transections from the caudal to rostral segment revealed that stepping activity of the limb on the lesioned side is reduced when the lesion is placed at the level between the C6 and C7 segment and then between C5 and C6. A slight reduction of activity was also observed after a lesion placed between C7 and C8. (2) Consistently, bilateral transection of the lateral funiculus at the level between C5 and C6 abolished stepping movements of both forelimbs. (3) The cervical cord was split in the parasagittal plane through the dorsal root entry. The operation removes the descending input to the segment in which the lesion is placed. The parasagittal lesions from the C1 to C6 did not abolish stepping activity, although a lesion placed between C5 and C6 could slightly affect stepping. The results, (1)–(3) suggest that the lateral funicular pathways project into the spinal segments mainly at the C6–C7 level with some rostrocaudal extension into C5 and C8. (4) Complete transections of the medial part of the spinal cord cut extensor bursts short and raised stepping frequency. Nevertheless, if the lesion at C1–C5 spared the ventromedial part of the ventral funiculus, it did not result in such high-frequency stepping or in weakened extensor activity. In the case of segments caudal to C6, medial transections which spared the corresponding region could result in such stepping. It is suggested that the pathways descending through the ventromedial part of the ventral funiculus in the rostral segments provide extensor activity during stepping. They may change their course in the more dorsal part of the ventral funiculus below the C6 and presumably project into the grey matter of more caudal segments.