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Biomedical subjects

J Klein

Publications and source records attributed to J Klein.

At least 829 records · Page 46Linked to original sources
PubMed1981

Cell-mediated lympholysis in H-2K/D identical congenic strain combinations.

Eight H-2K/D identical congenic strain combinations were tested in cell-mediated lympholysis. The reaction pattern of selected mouse strains revealed unidirectional reactivity to Tla-linked antigens in six strain combinations, whereas in two strain combinations the loci coding for the target antigen could only tentatively be linked to H-2. The Tla-linked loci defined by the different strain combinations appear to be identical with the H-2T (Qa-1) locus. Typing of B10.W lines for the H-2T (Qa-1) locus revealed the presence of alleles that appear to be the same as those present in inbred strains, as well as alleles that are different from the inbred-defined alleles but that share some determinants with the latter. The H-2T (Qa-1) system thus appears to consist of a limited number of alleles, some of which are closely related and presumably similar in their genetic structure.

Animals↗
PubMed1980

Alloreactive and H-2-restricted Lyt 23 cytotoxic T lymphocytes derive from a common pool of antecedent Lyt 123 precursors.

If the collaborative requirement of Lyt 1 T helper cells is bypassed by the Lyt 1 T cell-derived mediator of T help, termed Il-2, upon antigenic stimulation, PNA+ Lyt 123 thymocytes differentiate into either alloreactive or H-2-restricted PNA- Lyt 23 cytotoxic effector cells. Along the differentiation pathway from Lyt 123 leads to 23 effector cells, cytolytic activity is carried out by T cells that still express the Lyt 123 phenotype. The data establish that Lyt 23 CTL are produced by differentiation from antecedent Lyt 123 cells.

Animals↗
PubMed1980

Immobilisation and mechanical, support of individual protoplasts.

Mesophyl cell protoplasts of Vicia faba were suspended in a solution consisting of 10% sodium alginate and 0.4 M mannitol. The protoplasts could be immobilized by cross-linking the alginate in the presence of 100 mM CaCl2. Changes in the osmolarity of the external medium led to reversible shrinkage and swelling of the entrapped protoplasts. It was demonstrated by using the pressure probe technique that a pressure gradient (cell turgor pressure) of several 100 mbar is built up when the immobilized cells were transferred to hypotonic solution. By complexing the Ca2+ in the alginate matrix with sodium citrate buffer the protoplasts could be released from the matrix. No morphological change or alteration of the membrane permeability of the immobilized protoplasts was observed after a storage period of up to 14 days at 4 degrees C in the matrix.

Alginates↗
PubMed1980

[Aspiration curettage].

In a material of 665 aspiration curettages of the uterus we investigated the advantages and problems as well as the clinical reliability of this method. In 15% of all cases the procedure could not be proceeded by technical reason or by insufficient material for histological diagnosis. On the other hand diagnostic accuracy in endometrial cancer is as reliable as in conventional curettage in general anaesthesia. The curettage can easily be performed with minimal costs as an out-patient procedure. This is the main advantage of aspiration curettage.

Adult↗
PubMed1980

Neonatal tolerance of H-2 alloantigens. I. I region modulation of tolerance potential of K and D antigens.

By utilizing H-2 congenic strains of mice and appropriate recombinants, it has been possible to determine that Class I alloantigens (of K and D region genes) function poorly as tolerogens when inoculated into neonatal recipients. Alternatively, Class II alloantigens (encoded by I region genes) are excellent tolerogens. Moreover, Class I alloantigens are converted to good tolerogens when conjoined in the tolerizing inoculum with Class II alloantigens. The I subregions in which genes reside that mediate this tolerance-promoting effect are IJ and/or IE. It is suggested that elicitation of a suppressor mechanism, perhaps related to IJ region alloantigens, is responsible.

Animals↗
PubMed1980

Genetic linkage between Bf S0.7 (Bf S1) and HLA-Bw50.

Two hundred and one unrelated French Basque individuals were studied for HLA-A, B, C, DR and Bf polymorphisms. The results show that the Bf S0.7 (Bf S1) variant, which is known to be associated with HLA-Bw21, presents a highly significant linkage disequilibrium with a subtypic specificity, i.e., Bw50 (delta = 0.0123, delta S=100%, P less than 10(-8)). As neither Bf S0.7 variant nor Bw50 antigen is found in Mongoloid populations, it is suggested that in evolutionary terms, the Bf S0.7 mutation is a more recent event than the HLA-Bw21 split.

Alleles↗
PubMed1980

[Thrombophlebitis of internal cerebral veins in a case of systemic lupus erythematosus (author's transl)].

A 28-year-old man suffered from recurrent facial exanthema, arthritis and stomatitis for ten years and died six months after a catatonic episode with terminal cerebral convulsions. Three years before his death high KBR-Antititers to Herpes simplex- and cytomegalic virus were observed, while Lupus-Erythematosus-Tests (LE-Tests) only became positive in the last months. At autopsy, changes compatible with Systemic Lupus Erythematosus (SLE) were found in the mitral valves, the spleen, and the kidneys. The brain displayed hemorrhagic infarction of the striate bodies and thrombophlebitis of the internal cerebral veins, the wall of which exhibited circumscribed infiltrations with numerous hematoxilin bodies and LE cells. This seems to be the first observation of LE-specific changes in the brain. The importance of cerebral vein affection in SLE involving the nervous system is stressed and a hypothesis submitted proposing the viral etiology of SLE.

Adult↗
PubMed1980

Histocompatibility-2 system in wild mice. IX. Serological analysis of 13 new B10.W congenic lines.

Thirteen new B10.W congenic lines carrying wild-derived H-2 haplotypes on the genetic background of the C57BL/10Sn (=B10) strain, were analysed serologically for antigens encoded by the H-2K and H-2D loci. The analyses resulted in the description of 12 new private or low-frequency public H-2 antigens (designated H-2.127 through H-2.130, and H-2.133 through H-2.142) and six new H-2 haplotypes (designated H-2w21 through H-2w27). Six inbred, private or low-frequency public H-2 antigens were also found in the B10.W lines: H-2.17 in B10.CHA2, H-2.19 in B10.GAA37. H-2.21 in B10.DRB62 and B10.WOA105, H-2.25 in B10.STA62, H-2.31 in B10. KPA44 and B10.KEA5, and H-2.32 in B10.BUA16 and B10.BUA19. Virtually all these antigens occur in combinations with other class I antigens not represented among the available inbred strains, and thus constitute natural H-2 recombinants. Lines B10.LIB55, B10.STA10, and B10.STA12 appear to share the same K and D alleles; serologically indistinguishable are also lines B10.BUA16 and B10.BUA19, and B10.WOA105, B10.SNA57, and B10.DRB62.

Animals↗
PubMed1980

Neonatal tolerance induction across H-2 mutational disparity: induction and specificity of tolerance.

Mutational disparities derived from alleles of the H-2K and H-2D loci vary widely in their ability to induce neonatal tolerance. The more subtle mutations, such as Kbm5 and Kbm8, proved to be excellent tolerogens, but the Kbm3 mutant (M505) turned out to be the poorest tolerogen yet studied of all H-2 alloantigens. By challenging tolerant animals with skin grafts from related mutants, it was found that expression of tolerance was highly specific. Although a minority of tolerant animals failed to discriminate between the Kb, Kbm5 and Kbm8 antigens, they never failed to discern Kb, Kbm1 and Kbm3 as distinctly different alloantigens.

Alleles↗
PubMed1980

The histocompatibility-2 system in wild mice. XI. Ss and Slp properties of wild-derived H-2 haplotypes.

In this study, 14 B10.W lines were examined for genetic traits associated with the Ss protein and Slp alloantigen. Three B10.W lines were found to possess low levels of serum Slp alloantigen. Of these three Slp-positive lines, expression of the alloantigen was sex-limited in two lines (B10.LIB55 and B10.STA12) and constitutive, i.e., found in both sexes, in the remaining line (B10.KPB128). Lines which were found to be Slp-negative were also tested for IA-controlled immune response to Slp alloimmunization. The finding that one of these Slp-negative lines produced no detectable anti-Slp indicates that nonresponder alleles exist in wild populations. Further, the discovery of an unexpected immune response to Slp in F1 hybrids involving lines B10.LIB55 and B10.STA12 suggests the existence of a variant form of Slp alloantigen in these lines.

Alleles↗
PubMed1980

Murine antigen H-2.7: localization of its antigenic determinant to the Ss (C4) molecule.

Murine blood group antigen H-2.7 is encoded by a locus mapping in the vicinity of the S locus which codes for the Ss antigen carried by the fourth component of the complement pathway (C4). Normal mouse serum of H-2.7-positive strains contains a substance which inhibits anti-H-2.7 hemagglutination. This substance cannot be removed by passage of the serum through an anti-Ss immunoabsorbent column indicating that the Ss and H-2.7 antigens are present on separate molecules or molecular fragments in the serum. In contrast, fresh plasma either does not contain the H-2.7-bearing substance at all or it contains it at a far lower concentration than normal serum, although it has a normal level of the Ss-antigen-bearing substance. However, the H-2.7-positive substance appears when the plasma is allowed to stand for several hours, or when it is dialyzed and treated subsequently in a manner favoring spontaneous degradation of complement components. Removal of the Ss substance from the fresh plasma prevents the appearance of the H-2.7 antigen at any time thereafter. These findings indicate that the Ss and H-2.7 antigens are carried by the same molecule or molecular complex. The intact molecule expresses only the Ss antigen; the H-2.7 antigen is either hidden or masked so that it is inaccessible or poorly accessible to H-2.7 antibodies. Degradation of these molecules results in the generation of two fragments, a large fragment carrying the Ss antigen and a smaller H-2.7-positive fragment. The data are consistent with the interpretation that the H-2.7 antigen is encoded by the S locus, and that it is carried by that portion of the C4 molecule split off during complement activation.

Animals↗
PubMed1980

Genetic control of T-cell proliferative responses to poly(glu40ala60) and poly(glu51lys34tyr15): subregion-specific inhibition of the responses with monoclonal Ia antibodies.

The relationship between Ir genes and Ia antigens was studied in the T-cell proliferative responses to two synthetic polypeptides poly(glu40ala60) (GA) and poly(glu51lys34tyr15) (GLT15). The response to GA was found to be controlled by an Ir gene in the I-A subregion, whereas the anti-GLT15 response was shown to be under dual control, one Ir gene mapping probably in the I-A subregion, and the other in the I-E subregion. We obtained two different lines of evidence suggesting identity of Ir and Ia genes. First, the presence of certain serologically identified allelic forms of the I-A-encoded A molecule correlated with the responder status to GA both in inbred strains and in B10.W lines, the latter carrying wild-derived H-2 haplotypes. Thus the Ir and Ia phenotypes were not separable in strains of independent origin. Second, the anti-GA response was completely inhibited by monoclonal antibodies against determinants on the A molecule (Ia.8, 15, and 19), but not by a monoclonal antibody against a determinant on the E molecule (Ia.7). In contrast, the anti-GLT15 response was only inhibited by a monoclonal antibody against the E molecule, but not by antibodies against the A molecule. Our data support the hypothesis that Ia antigens, as restriction elements for T-cell recognition, may in fact be the phenotypic manifestation of Ir genes.

Alanine↗
PubMed1980

[HLA antigens and responsiveness to tetanic toxoid in man].

HLA-A, B, C and Bf antigens were studied in 153 blood donors who developped a titre of greater than or equal to 25 i.u./ml antitetanus antibodies following tetanus anti-toxin vaccination. Antigen frequency was compared with that of 412-464 normal blood donors living in the same area. Few significant differences were demonstrated: absence of Bw21 antigen and slight increase of Bf F antigen were observed in "good responders".

HLA Antigens↗
PubMed1980

High frequency of the properdin factor Bf F1 and its linkage to HLA in French Basques.

We studied 201 unrelated French Basque individuals for HLA and Bf polymorphisms. The haplotypes of eighty-seven of them were deduced from family studies. The results show the frequency of the Bf F1 allele (0.1393) which is the highest one currently reported. They confirm the high frequencies of HLA-Aw19.2 and B18 previously reported in that population and show that a whole haplotype with strong linkage disequilibria, namely Aw19.2, Cw5, B18, Bf F1, DRw3 is frequent. On the other hand, the gene frequency of Bf S is decreased (0.5497) as compared with the other European Caucasoïd populations, while a slight increase in the Bf F gene frequency (0.2960) appears. These results point out that it is of importance to consider the genetic background choosing the population where linkage disequilibria are to be studied.

Alleles↗
PubMed1980

Adult respiratory distress syndrome in the course of acute myocardial infarction.

The diagnosis of adult respiratory distress syndrome (ARDS) has been made in our intensive coronary care unit in four patients during the course of acute myocardial infarction (AMI). In all four patients, the syndrome manifested itself either after resuscitation or after a transient hypotensive state. In two of the patients none of the conditions known to be possible etiologies of ARDS was present; in the third, smoke inhalation preceded; and in the fourth, aspiration followed the AMI. The clinical and x-ray pictures were indistinguishable from acute left heart failure, the PaO2 levels were about 40 mm Hg, and a low pulmonary arterial wedge pressure was measured in all cases. Positive end-expiratory pressure was used successfully, combined with other therapeutic measures, and three patients recovered from the ARDS. The association of ARDS and AMI carries a grave risk in view of the additional damage that may be caused by the severe hypoxemia to the already compromised myocardium. The AMI, if complicated by circulatory arrest, cardiogenic shock, or hypotension, seems to be an etiologic factor in the development of ARDS and it should be added to the growing list of conditions that may give rise to this new syndrome.

Aged↗