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Biomedical subjects

J Schilling

Publications and source records attributed to J Schilling.

At least 91 records · Page 5Linked to original sources
PubMed1985

Structure of canine pulmonary surfactant apoprotein: cDNA and complete amino acid sequence.

The apoproteins of pulmonary surfactant (PSAP) are thought to be critical for normal surfactant function. They bind to surfactant phospholipids and enhance their ability to form surface films in vitro. These acidic glycoproteins have monomeric molecular weights of 36,000, 32,000, and 28,000 (PSAP-36, -32, and -28). Each member of this family of proteins has a similar amino acid composition and their differences in electrophoretic mobility are due in part to glycosylation. We have derived the full amino acid sequence of PSAP-32 from the nucleotide sequence of PSAP cDNA. A cDNA library was prepared from canine lung poly(A)+ RNA and screened with oligonucleotide probes that were based on the NH2-terminal amino acids of PSAP-32 determined by Edman degradation. This protein has the striking feature of collagen-like and non-collagen-like sequences in the same polypeptide chain. There are 24 Gly-Xaa-Yaa triplets, where Yaa is often hydroxyproline. These repeats comprise one-third of PSAP near the NH2 terminus. The remaining two-thirds of PSAP is resistant to bacterial collagenase digestion and contains a possible N-glycosylation site near the carboxyl terminus. The NH2-terminal one-third of PSAP-32 probably contains the cysteine involved in interchain disulfide bonds.

Amino Acid Sequence↗
PubMed1985

Salpingitis isthmica nodosa in female infertility.

A retrospective study was undertaken to evaluate the radiologic appearance of salpingitis isthmica nodosa (SIN) in the fallopian tubes of 150 consecutive patients having hysterosalpingograms performed almost exclusively for primary and secondary infertility. SIN was observed in 13 of these 150 patients. The characteristic radiologic features of this condition are minute loculations of contrast medium adjacent to the tubal lumen which range in size up to 2 mm in diameter and are clustered together over a tubal length of 1 to 2 cm. Although the most frequent site of occurrence is in the proximal isthmic portion of the tube, there is occasional involvement of the distal isthmus and even the interstitial portion of the adjacent uterine cornu. Associated tubal abnormalities in this condition such as hydrosalpinx and tubal occlusion help explain the increased incidence of tubal pregnancy and infertility in patients with SIN.

Adult↗
PubMed1984

Construction and analysis of DNA sequence libraries from flow-sorted chromosomes: practical and theoretical considerations.

We describe the construction and analysis of recombinant DNA libraries representative of chromosomes 1 and 2 of Chinese hamster (Cricetulus griseus). Propidium-iodide stained chromosomes were purified by flow cytometric analysis and sorting, and EcoRI digests of purified DNA were cloned into the bacteriophage vector Charon 4A. These libraries contain DNA complementary to 63% and 69% of nick-translated DNA derived from flow-purified chromosomes 1 and 2, respectively. However, sequences complementary to only 24% and 35% of a total Chinese hamster genomic DNA tracer were hybridized in parallel renaturation experiments. The chromosome 2 library contained DNA sequences encoding dihydrofolate reductase (dhfr), a gene previously mapped to Chinese hamster chromosome 2. No sequences complementary to dhfr were found in the library constructed from chromosome 1 DNA. These analyses are discussed with regard to the current limitations and future strategies for the construction of chromosome-specific DNA sequence libraries of high purity and completeness.

Animals↗
PubMed1983

Combining site specificities of mouse hybridoma antibodies to dextran B1355S.

The combining sites of 12 mouse hybridoma antibodies to dextran B1355S have been characterized by quantitative precipitin assay. All antibodies preferentially bind the immunizing antigen B1355S and two other class I dextrans, B1498S and B1501S, but show substantial differences in the extents to which they cross react with class I dextrans, suggesting their clustering into five groups. Three myeloma proteins, CAL20 TEPC1035, J558, and MOPC104E, which bind dextran B1355S, each fall into a different group. There appears to be a substantial, but imperfect, correlation of DH region structure and individual idiotypic determinants with dextran binding patterns. Proteins with RY DH segments and IdI (J558) idiotypes are in groups 1 or 3, and proteins with YD DH segments and IdI (MOPC104E) idiotypes are exclusively in group 5. However, identical patterns of precipitin curves accompany very different sequences in CDR3. Antibodies of group 1, which react only with class II dextrans, differ the most in primary sequence, a finding suggesting that subsites responsible for cross reactivity with class I dextrans may be blocked and that this may be effected by side chains of different amino acids. This finding delineates a new aspect of the relationship of variability in amino acid sequence to antibody complementarity.

Amino Acid Sequence↗
PubMed1982

Acute megakaryoblastic leukemia (acute "malignant" myelofibrosis): an unusual cause of osteosclerosis.

Acute megakaryoblastic leukemia or acute "malignant" myelosclerosis is an acute and rapidly progressive myeloproliferative syndrome characterized by minimal or absent splenomegaly, pancytopenia, diffuse marrow fibrosis, and circulating blasts of megakaryocytic origin. The disease must be differentiated from other hematologic malignancies especially myelofibrosis with myeloid metaplasia. The radiographic changes of osteosclerosis in our patient have not been previously reported in the literature.

Acid Phosphatase↗
PubMed1980

Structural correlates of cross-reactive and individual idiotypic determinants on murine antibodies to alpha-(1 leads to 3) dextran.

For the first time V-region amino acid sequence differences have been correlated with the expression of cross-reactive and individual idiotypes through an analysis of 12 dextran-binding proteins. This correlation has been possible because of the apparent sequence identity of the corresponding lambda chains. Expression of a cross-reactive idiotype was localized to two residues and/or a carbohydrate in the second hypervariable region of the heavy chain. Two individual idiotypes correlate with the two amino acids within the third hypervariable region that comprises the D segment of the dextran-binding proteins. These results demonstrate that idiotype reagents can recognize two amino acid differences within V and D segments of classical variable regions. In anti-dextran antibodies, cross-reactive idiotypes involve V-region determinants, whereas individual idiotype determinants correlate with D-segment variation.

Amino Acid Sequence↗
PubMed1980

The joining of V and J gene segments creates antibody diversity.

The variable regions of mouse kappa (kappa) chains are coded for by multiple variable (V) gene segments and multiple joining (J) gene segments. The V kappa gene segments code for residues 1 to 95; the J kappa gene segments code for residues 96 to 108 (refs 1-3). This gene organisation is similar to that encoding the V lambda regions. Diversity in V kappa regions arises from several sources: (1) there are multiple germ-line V kappa gene segments and J kappa gene segments; (2) combinatorial joining of V kappa gene segments with different germline J kappa gene segments; and possibly, (3) somatic point mutation, as postulated for V lambda gene segments. Also, from a comparison of the number of germ-line J kappa gene segments and amino acid sequences, it has been suggested that J kappa region sequences may be determined by the way V kappa and J kappa gene segments are joined. This report supports this model by directly associating various J kappa sequences with given J kappa gene segments.

Animals↗
PubMed1980

Amino acid sequence of homogeneous antibodies to dextran and DNA rearrangements in heavy chain V-region gene segments.

The complete variable region sequences from ten antibodies and two myeloma proteins binding alpha-1,3 dextran have been determined. The diversity patterns of these homogeneous antibody molecules suggest that the variable regions of heavy chains are encoded by separate variable (V) and joining (J) gene segments. The most striking feature of these data is the extensive sequence variability of a region that we denote the D (diversity) segment which is located at the junction between the V and J segments in the centre of the third hypervariable region. The D segment diversity may arise from a novel somatic mutational mechanism or may be encoded by multiple D gene segments. For the first time, the amino acid sequence correlates of several V region idiotypes are determined.

Amino Acid Sequence↗
PubMed1979

Sequence of histone 2B of Drosophila melanogaster.

The complete sequence of histone 2B of Drosophila has been determined by using an improved Beckman sequenator. Comparing these data with those previously published by other investigators on the histone 2B of calf [Iwai, K., Hayashi, H., & Ishikawa, K. (1972) J. Biochem. (Tokyo) 72, 357--367], trout [Koostra, A., & Bailey, G. S. (1978) Biochemistry 17, 2504--2510], and Patella (a limpet) [van Helden, P. D., Strickland, W. N., Brandt, W. F., & von Holt, C. (1979) Eur. J. Biochem. 93, 71--78], it is possible to assess the evolutionary stability of this protein. There is little conservation of sequence in the N-terminal portion of the molecule (residues 1--26 numbering according to calf H2B), while the remainder of the protein, which we designate the C-terminal portion, is highly conserved. In the region of 27--125 residues, there are 9 substitutions in the composite data among the 98 positions, 8 of them conservative. These data indicate that very different selective pressures operate on the two different portions of the H2B molecule, implying the existence of two well-defined regions. Studies on the structure of the nucleosome by others have suggested that the C-terminal portion of H2B is involved in histone-histone interactions while the N-terminal portion is a relatively free "tail" binding to DNA. The sequence data indicate that the function of the C-terminal region of H2B requires considerable sequence specificity while that of the N-terminal region does not.

Amino Acid Sequence↗
PubMed1979

Amino acid sequence of a mouse immunoglobulin mu chain.

The complete amino acid sequence of the mouse mu chain from the BALB/c myeloma tumor MOPC 104E is reported. The C mu region contains four consecutive homology regions of approximately 110 residues and a COOH-terminal region of 19 residues. A comparison of this mu chain from mouse with a complete mu sequence from human (Ou) and a partial mu chain sequence from dog (Moo) reveals a striking gradient of increasing homology from the NH2-terminal to the COOH-terminal portion of these mu chains, with the former being the least and the latter the most highly conserved. Four of the five sites of carbohydrate attachment appear to be at identical residue positions when the constant regions of the mouse and human mu chains are compared. The mu chain of MOPC 104E has a carbohydrate moiety attached in the second hypervariable region. This is particularly interesting in view of the fact that MOPC 104E binds alpha-(1 leads to 3)-dextran, a simple carbohydrate. The structural and functional constraints imposed by these comparative sequence analyses are discussed.

Amino Acid Sequence↗
PubMed1979

Analysis of the diversity of murine antibodies to dextran B1355: N-terminal amino acid sequences of heavy chains from serum antibody.

The N-terminal amino acid sequences of two gamma and two mu chains from normally induced serum antibodies to dextran in BALB/c mice are presented. These heavy chains are derived from antibodies with three distinguishable idiotypes. These variable region (VH) sequences are all identical as far as they have been analyzed (27 to 53 residues). The light chains from these antibodies are all of the lambda type and are identical by isoelectric focusing analysis. Accordingly, the diversity of dextran antibodies appears to reside primarily in the heavy chains. The implications of these observations for antibody diversity are discussed.

Amino Acid Sequence↗
PubMedDate not supplied

Rearrangement of genetic information may produce immunoglobulin diversity.

The nearly complete amino-acid sequences of 22 closely related immunoglobulin kappa variable (Vkappa) regions from the inbred NZB mouse are presented. This group of Vkappa regions is encoded by at least six germline Vkappa genes. These data also suggest that the mouse kappa gene is divided into three segments termed V or variable (residues 1 to 98 or 99), J or joining (residues 99 or 100 to 112) and C or constant (residues 113--219). Tonegawa et la. have recently described a similar J segment for mouse lambda chains. Inbred mice contain multiple Vkappa and Jkappa gene segments. Therefore, different combinations of V and J gene segments may be joined at the DNA level during the differentiation of individual lymphocytes to contribute to antibody diversity.

Amino Acid Sequence↗