Human cDNA encoding DnaJ protein homologue

We have cloned a cDNA encoding a DnaJ-like protein from the human fibrosarcoma HT-1080 cDNA library. This cDNA encodes a protein of 397 amino acid residues whose sequence shows 38.2% identity with the Escherichia coli DnaJ protein and 47.2% with the yeast DnaJ homologue along the entire length. Since the sequence contains the N-terminal domain region conserved in DnaJ family members and the four repeats of the Cys-X-X-Cys-X-Gly-X-Gly motif which are characteristic of DnaJ proteins, we conclude that this cDNA clone encodes the human homologue of DnaJ.

Resolution enhancement of biomagnetic images using the method of alternating protections

Resolution of biomagnetic images using the technique of the alternating projections is proposed. Our image reconstruction procedure is divided in two steps. First, the biomagnetic inverse problem is solved by use of the projection theorem to reconstruct an initial image of the current distribution from a given magnetic field profile. Although the current distribution thus obtained has poor resolution, it can resemble the original shape of the current distribution. The second step improves the resolution of the reconstructed image by using the method of alternating projections. The procedure assumes that images can be represented by line like elements and involves finding the line like elements based on the initial image and projecting back onto the original solution space. Simulation studies were performed on a set of parallel conductors and a shape of the conductors in the form of letters, UWB@. All conductors were of line like thickness. Restored images closely resemble the original shape of the conductors.

Avian species-specific tandem repeats contain nuclear protein binding sites

Three avian highly repetitive tandem repeats were identified and examined. These repeats had similar unit lengths (about 42 bp long) but completely different sequences each containing particular protein binding sites. Each of these repeats was found within only one of the five closely related genera studied.

Avian tandem repeats: nuclear protein binding sites and the origins of short tandem repetitive DNAS

A 14 bp repeat isolated from the genome of a Mallard duck (Anas platyrhynchos) and a 13 bp repeat isolated from the genome of a Muscovy duck (Cairina moschata) were both tandem and genus-specific. There were 2.1 x 10(6) copies of the 14 bp repeat in the Mallard duck genome and 1.3 x 10(6) copies of the 13 bp repeat in the Muscovy duck genome. These two repeats were not obviously homologous but each contains different transcription protein binding sites. Experimentally, the two repeats were also observed to bind nuclear proteins specifically. A sequence-selective mechanism for the expansion of short tandem repeats from single ancestral sequences containing nuclear protein binding sites is presented.

Dispersive propagation skew effects in iterative neural networks

During communication between neurons in a continuous-time analog neural network, propagation skew typically varies from neuron pair to neuron pair. For no dispersion, S. Oh et al. (Opt. Eng., vol.28, p.526-32, 1989) previously demonstrated that the steady-state performance of an iterative neural network is not affected if the combination of the neural network's weights and neural nonlinearity is contractive. This result is extended to the case of dispersive skew. It is shown that, under nearly the same conditions, the same steady-state result will occur in the neural network in the presence of dispersive skew.

[Congenital esophagobronchial fistula communicated to esophageal diverticulum, report of a case]

We encountered a successful repair of congenital esophagobronchial fistula communicated to esophageal diverticulum. A 35 year-old-female has had frequent episodes of pneumonia since her 1st delivery. Barium esophagogram revealed a fistulous tract between the esophageal diverticulum and the right lower lobe bronchus. Bronchogram showed a ectatic dilatation at B6a and B6c. The resection of diverticulum and right lower lobectomy including the removal of fistulous tract were carried out. Histological examination of the resected fistula revealed a smooth connection between squamous epithelium and columnar epithelium. And muscularis mucosa was maintained with no evidence of inflammatory changes. So this case was diagnosed a Braimbridge I type esophagobronchial fistula. In Japan 21 cases of congenital esophagobronchial fistula with diverticulum have been reported. It is assumed that three histological findings as mentioned above is important for the diagnosis of congenital esophagobronchial fistula.

The structure of avian type XII collagen. Alpha 1 (XII) chains contain 190-kDa non-triple helical amino-terminal domains and form homotrimeric molecules

The monoclonal antibody 75d7, specific for type XII collagen (Sugrue, S.P., Gordon, M.K., Seyer, J., Dublet, B., van der Rest, M., and Olsen, B. R. (1989) J. Cell Biol., in press), was used to characterize the intact form of type XII collagen from chick embryo leg tendons. On an immunoblot of a 6% polyacrylamide gel of tendon extracts, one sharp band is recognized by the antibody at Mr = 220,000, while two fuzzy and poorly resolved bands are seen at Mr = 270,000 and Mr = 290,000. By immunoprecipitation of radiolabeled tendon culture media and electrophoresis of the precipitated material, bands with the same mobilities are observed, indicating that type XII collagen is not proteolytically processed in the extracellular space. Type XII collagen was extracted from tendons with 1 M NaCl in a Tris-HCl buffer and partially purified by concanavalin A-Sepharose and gel permeation chromatographies, using dot immunoblots to monitor the purification. Fractions highly enriched in bacterial collagenase-sensitive proteins with the same electrophoretic properties as type XII collagen were obtained. These fractions did not stain with Alcian blue and neither they nor the immunostained type XII collagen were affected by chondroitinase ABC digestion, indicating that type XII collagen is not a proteoglycan. A disulfide-bonded trimeric CNBr peptide was isolated by affinity chromatography on an antibody column and further purified by gel electrophoresis. Its NH2-terminal amino acid sequence was shown to be unique, demonstrating that type XII collagen is a homotrimer [alpha 1 (XII)]3. After bacterial collagenase digestion, both the immunopurified radiolabeled preparation and the purified tendon extract fraction showed by gel electrophoresis the presence of a large disulfide-bonded, 3 x 190-kDa, collagenase-resistant domain. Rotary shadowing and electron microscopy of the purified type XII fraction demonstrated that the molecule has the structure of a cross consisting of a 75 nm collagenase-sensitive tail, a central globule, and three 60 nm arms each ending in a small globule. After heat denaturation and renaturation, only a very large globule can be seen, attached to the triple helical tail. These results show that type XII collagen has a unique structure and is different from the other matrix constituents described so far.

[A case of pulmonary carcinoma presenting flow cytometrical heterogeneity of the nuclear DNA content between its primary focus and the metastatic foci]

We have experienced case involving a 63-year-old patient with a pulmonary carcinoma, who was given an enterectomy following a lobectomy, due to minimal intestinal metastasis. In this case, using flow cytometry, the cancer cell nuclear DNA content was analyzed for the primary tumor focus, the mediastinal lymph node metastatic focus, and the small intestinal metastatic focus. For the primary focus, a cancer cellular population of polyploidy with 2 ploidies of DNA content was observed, while for both the metastatic foci, only a single cancer cellular population was observed, indicating the heterogeneity of the nuclear DNA content between the primary focus and metastatic foci. These 2 metastatic foci had DNA contents completely corresponding to that for a ploidy with a high DNA content in the primary focus, suggesting a metastasis of only the above population from the primary focus. The present case apparently formed metastatic foci in other organs than the lungs but only by cancer cells more susceptible to metastasis among the cancer cells found in the primary focus.