Molecular cloning and nucleotide sequence of the beta-lytic protease gene from Achromobacter lyticus

Two bacteriolytic enzymes secreted by Achromobacter lyticus M497-1 were purified and identified as being very similar (considering their amino acid composition and N-terminal sequence) to alpha- and beta-lytic proteases from Lysobacter enzymogenes. A 1.8-kb EcoRI fragment containing the structural gene for beta-lytic protease was cloned from A. lyticus chromosomal DNA. The protein sequence deduced from the nucleotide sequence was identical to the known sequence of beta-lytic protease, except for six residues. The nucleotide sequence revealed that the mature enzyme is composed of 179 amino acid residues with an additional 195 amino acids at the amino-terminal end of the enzyme, which includes the signal peptide, thus indicating that the enzyme is synthesized as a precursor protein.

Marfan syndrome in China: a collective review of 564 cases among 98 families

This is a collective review of 564 patients with Marfan syndrome among 98 pedigrees reported from 18 provinces and cities in China over a 37-year period from 1951 to 1987. A positive family history of Marfan syndrome was found in 74.3% of the patients: the mode of inheritance was dominant in 73.8% and recessive in 0.5%. Sporadic cases occurred in 25.7%. A screening of 29,067 children found five children with Marfan syndrome, giving a prevalence of 17.2 per 100,000 of the population, a gene frequency of 8.61 per 100,000 genes, and a penetrance of 71.69%. Pleiotropy was clear in these cases: arachnodactyly in 77%, ectopia lentis in 86.8%, and dilated aortic root in 80.1%. Chromosome examination showed no regular aberrations except in a family of five in whom a giant-satellited chromosome 14 was found in three afflicted members but not in the two unaffected relatives. The high prevalence of aortic root dilation in Marfan syndrome makes echocardiography the most useful and practical means of diagnosis. Close follow-up and regular echocardiographic evaluation are indicated not only in patients with Marfan syndrome but also in their families, for both diagnostic and therapeutic purposes.

Dynamic study on iliac trabeculae of normal Chinese

We studied 41 iliac bone blocks taken by biopsies from normal Chinese who were divided into several groups by age. On the schedule of 3-11-3-5 days, double tetracycline labellings were administered before bone biopsies. Ten microns undecalcified sections were made with Reichert-Jung microtome and analyzed with Zeizz MOP-Videoplan by light and fluorescent microscopy. The results showed that bone formation had a peak value at adolescence and the mean wall thickness decreased gradually with age. Bone dynamics fluctuated with age because of endocrinological changes in the intrinsic environment. The data we obtained may be used as a reference for clinical investigation of various metabolic bone disorders.

[Establishment of a human cancer cell line from adenoid cystic carcinoma of the minor salivary gland]

This paper reports the establishment of a human cancer cell line from adenoid cystic carcinoma of the minor salivary gland and the study of its biological behaviours. The cells of the cell line (SACC-83) are polygonal in shape, with a mosaic arrangement. Ultrastructural study reveals that many secretory granules are present in the cytoplasm. The mitosis index, growth curve, chromosome analysis and transplantation into nude mice were performed and discussed. The results prove that this cell line possesses the morphological and biological features of adenoid cystic carcinoma.

Planned simple carotid resection in surgery of paraganglioma fixed to the carotid artery

Of 25 surgically treated cases (1956-1986) of paraganglioma, eleven underwent simple carotid resection. The collateral cerebral crossflow was promoted preoperatively with the use of compressing exercises of the carotid artery and controlled by rheoencephalography. There was no operative mortality. One died with a malignant lesion, and nine survived 3 months to 21 years without cerebrovascular complications. It appears that this procedure is worthwhile in selected cases.

Functional tracheoesophageal shunt for vocal rehabilitation after laryngectomy

A new one-stage surgical technique for postlaryngectomy vocal rehabilitation was applied to 19 patients with advanced carcinoma of the larynx. The technique consists mainly of the construction of a tracheoesophageal shunt and the creation of a tracheoesophageal flap to cover the shunt preventing entry of food into the trachea. Fifteen of the 19 patients developed useful speech. Slight leakage of liquids into the trachea occurred in four patients. This is avoided by having the patient bend his head down during deglutition. This technique can be performed in a wide variety of clinical situations and restores effortless speech without any special training.

Morphological and functional investigations on macrophages with heterogeneous fluorescent staining

Four heterogeneous colors of fluorescence were demonstrated in macrophages from rabbit lymph nodes and mouse peritoneal exudate using fluorescent staining. They were bright blue, light blue, bluish green and yellow colors of fluorescence respectively. All of these 4 types of macrophages with heterogeneous colors of fluorescence could form EA or EAC rosettes and were able to phagocytose chicken erythrocytes and ink carbon granules. Among them the macrophages with bright blue color of fluorescence could form large EA or EAC rosettes and showed more rapid and stronger activity to phagocytose chicken erythrocytes, while those with bluish green and yellow colors of fluorescence showed stronger activity to phagocytose ink carbon granules.

The triphasic reduction of cytochrome b in the succinate-cytochrome c reductase

In the succinate-cytochrome c reductase, the reduction of cytochrome b has been found to be triphasic: an initial rapid partial reduction was followed first by a rapid oxidation and then finally by a slow reduction. The initial reduction of cytochrome b was faster than that of cytochrome c1 and the final slow reduction of cytochrome b began when cytochrome c1 reduction was approaching completion. In presence of the inhibitors antimycin A or HQNO the reduction of cytochrome b became monophasic. Hysteresis or a kinetic cooperative effect of a factor controlling cytochrome b oxidation has been suggested as a possible explanation for the triphasic reduction of cytochrome b.

Purification and physicochemical properties of ricins and agglutinins from Ricinus communis

Two toxin ricins and two agglutinins have been purified from the seeds of Ricinus communis by an improved procedure based on ion-exchange chromatography and gel filtration. One of the two purified ricins binds to Sepharose 4B while the other does not. The physicochemical properties of the four Ricinus lectins are presented and the possible relationships of these Ricinus lectins to those previously described are discussed.

The structure of monellin and its relation to the sweetness of the protein

The sweet protein monellin [1-3] has been shown to consist of two non-identical subunits of 50 and 42 amino acid residues, which were separated electrophoretically and chromatographically. Automatic sequential Edman degradation gave the complete sequence of the longer subunit, and a partial sequency of the shorter one. It was found that the sweetness of monellin requires the undissociated molecule. The individual subunits were not sweet, neither did they block the sweet sensation of sucrose or monellin. Blocking of the single SH of monellin abolished its sweetness as did reaction of the single methionyl residue with CNBr. Since the cysteinyl and methionyl residues appear to be adjacent, it is suggested that this part of the molecule is essential for its sweetness.

Amino-terminal sequence of the tryptophan synthetase alpha chain of Bacillus subtilis

The sequence of the 46 NH(2)-terminal residues of the tryptophan synthetase alpha chain of Bacillus subtilis was determined and compared with the corresponding sequences of Escherichia coli, Shigella dysenteriae, Salmonella typhimurium, Aerobacter aerogenes, Serratia marcescens, and Pseudomonas putida. A deletion of six residues was found at the NH(2)-terminal end of the alpha chain of B. subtilis.

Nucleotide sequence divergence in the -chain-structural genes of tryptophan synthetase from Escherichia coli, Salmonella typhimurium, and Aerobacter aerogenes

Two different estimates were obtained for the extent of nucleotide sequence divergence in the structural genes of the tryptophan synthetase alpha-chains of Escherichia coli, Salmonella typhimurium, and Aerobacter aerogenes. One estimate was based on comparisons of the amino acid sequences of the respective alpha chains. The other was derived from measurements of the thermal stability of RNA-DNA hybrids formed with phage DNA carrying the alpha-chain structural gene of E. coli and labeled messenger RNA from the three bacterial species. Comparison of the two estimates suggests that during the course of evolution synonymous codon changes have accumulated in the alpha-chain-structural genes.

Amino terminal sequence of the tryptophan synthetase alpha chain of Serratia marcescens

The sequence of the amino terminal 28 residues of the tryptophan synthetase alpha chain of Serratia marcescens is presented and compared with the related sequences of alpha chains of other bacteria.

Gene locus specificity of the glucose effect in the thiamine pathway of the angiosperm, Arabidopsis

All mutants at 3 loci in Arabidopsis thaliana (L.) Heynh., a higher plant, that are associated with the synthesis or coupling of the thiazole moiety of thiamine are susceptible to reversible glucose inhibition. In contrast, several different alleles involved in the synthesis of the pyrimidine moiety of the vitamin are insensitive to glucose. Glucose and maltose are equally effective inhibitors while fructose, lactose, ribose, and xylose are toxic. This toxicity is not released by added thiamine.

Direct evidence for models of heterosis provided by mutants of Arabidopsis blocked in the thiamine pathway

Auxotrophic mutants genetically blocked at different steps of the thiamine pathway dramatically demonstrate the biochemical mechanism of hybrid vigor due to simple and perfect dominance at two unlinked loci. Heteroallelic hybrids of mutants requiring the pyrimidine moiety of thiamine display allelic complementation and thus furnish clear biochemical and genetic evidence for the superdominance hypothesis. Hybrids of low- and high-temperature-requiring leaky mutants demonstrate that heterozygosity at a single gene locus may confer developmental homeostasis on the heteroallelic combinations superior to that of the homoallelic parents. The results of this study on the autogamous plant, Arabidopsis, and of recent reports on the outbreeding species, Drosophila, render untenable the generalization that high versus low temperature dependent heterosis is determined by the breeding system.ZUSAMMENFASSUNG: Auxotrophe Arabidopsis-Mutanten, bei denen verschiedene Schritte der Thiaminsynthese genetisch blockiert sind, lassen deutlich den biochemischen Mechanismus der Heterosis erkennen, der auf einfacher und völliger Dominanz in zwei ungekoppelten Loci beruht. Heteroallele Hybriden von Mutanten, die den Pyrimidinanteil des Thiamins benötigen, zeigen allele Komplementation und liefern damit den klaren biochemischen und genetischen Beweis für die Superdominanz-Hypothese. Hybriden von leaky-Mutanten, die einen niedrigen bzw. hohen Temperaturbedarf haben, zeigen, daß Heterozygotie in einem einzelnen Genlocus den heteroallelen Kombinationen eine Entwicklungshomeostasie verleihen kann, die größer als die der homoallelen Eltern ist. Die Ergebnisse unserer Untersuchungen an der autogamen Pflanze Arabidopsis und neuere Ergebnisse bei Drosophila lassen die Verallgemeinerung, daß die Art der Temperaturabhängigkeit der Heterosis durch das Zuchtsystem bestimmt wird, nicht zu.