Since the original discovery of T-and B-cell collaboration in the antibody response, it has been generally accepted that the helper T cell represents a single subset in the multimember family of T cells. There are, however, some controversial findings on the nature of the help with respect to its specificity, class preference, and genetic restrictions. In the antibody response to a hapten.carrier conjugate, the helper T cell is believed to recognize the carrier determinant and then to help antibody synthesis by B cells which recognize another determinant (hapten) linked to the same molecule. This type of interaction is supported by a phenomenon known as the carrier effect, in which the hapten-specific secondary antibody response is successfully elicited by the hapten coupled to the same carrier by which animals have been primarily immunized (1-4). A similar cooperative interaction between hapten-specific B cells and carrier-specific T cells is readily demonstrable in the adoptive secondary antibody response (5-8). Since in these cases hapten and carrier determinants must be present on a same single molecule, the T-B collaboration should occur upon recognition of the hapten by B cells, and recognition of the adjacent carrier determinants by T cells in a cognate form.There are certainly no denials of the presence of this type of interaction. Nevertheless, there are several examples in which the cognate interaction is not likely to occur in certain T-cell-dependent antibody responses. In fact, various antigen-nonspecific factors derived from T cells can trigger the B-cell response, in which the factors themselves do not recognize carrier determinants (9-13). Several investigators are also aware that the hapten-specific B cells can be triggered under certain circumstances in which B and T cells are independently stimulated by corresponding determinants present on two distinctly separate molecules (8,12,14,15). Hence, cognate interaction is not the only pathway for the effective T-B cell collaboration. One could ask whether the same or different helper T cells are involved in these diverse pathways of T-B cell collaboration.Such problems are now even more complicated by the growing evidence suggesting that the helper T cell may recognize not only the carrier determinants, but also the products of major histocompatibility gene complex (MHC).

SUMMARY: A total of 325 pueruli of the spiny lobster Panulirus japonicus was successfully reared in the laboratory at Minami‐Iku Station of Japan Sea‐Farming Association, Shizuoka, Japan, during 1989–1997. Of these pueruli, 136 individuals metamorphosed into the first juvenile stage. The duration of the phyllosoma stage ranged from 231 to 417 days (mean 319.4 days), and it has a tendency to extend as the increase of water volume in the rearing tanks. The number of molting in the phyllosoma stage was 20–31. The body length of the last‐stage phyllosoma ranged from 27.9 to 34.2 mm and the duration of the last stage was 11–26 days. The carapace length of the puerulus stage was 6.0–8.0 mm and the duration was 9–26 days. The present data and those of previous studies suggest that the body size and the duration of phyllosoma stage in captivity are affected by environment as in the field. The duration of the puerulus stage is considered to be controlled basically by water temperature and nutritional conditions in the phyllosoma.

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The thoracic cage after a lung resection is filled by the remaining lobes, the elevated diaphragm, the diminished thoracic cage, and by mediastinal shifting. The changes in the thorax after a lung resection were quantified using magnetic resonance imaging. The study group consisted of 39 patients who had undergone a lobectomy, four who had undergone a pneumonectomy, and 14 controls. The left ventricular angle, ascending aortic angle, mediastinal shift, longitudinal length of the thoracic cage, the distance between the thoracic apex and the level of the aortic valve, and diaphragmatic elevation were all measured. After a right lower lobectomy, the mediastinum shifted more rightward than after a right upper lobectomy. The diaphragm became more greatly elevated after a right upper lobectomy than after a right lower lobectomy. When a chest wall resection was added to a right upper lobectomy, the mediastinal anatomical changes decreased. After a left upper lobectomy, the degree of mediastinal shifting was greater than after a left lower lobectomy. A left upper lobectomy shifted the mediastinum at the level of the right atrium. This method is easily reproducible and was found to be effective for quantifying the changes in the thorax after a lung resection.