Proteases in the human full-term placenta

Summary Aminopeptidase A, not yet defined aminopeptidases and endopeptidases, dipeptidyl peptidase I, II and IV, -glutamyl transferase and oxytocinase were investigated in the normal human full-term placenta using qualitative (catalytic) cytochemistry, isoelectric focusing, immunocytochemistry and kinetic fluorometry. Aminopeptidase A could be visualized cytochemically in the smooth muscle cells of the chorionic plate, stem villi and basal plate blood vessels. Aminopeptidases were found in connective tissue fibres of the chorionic plate, villous stroma, basal plate and paraplacenta. Dipeptidyl peptidase IV was detected at the same sites as the aminopeptidases and, in addition, in amniotic epithelial cells, fibroblasts of the villous stroma, endothelium of chorinic plate and villous blood vessels as well as in the basophilic cytotrophoblast cells (x-cells) of the basal plate and paraplacenta, and it possibly also occurred in some domains of the plasma membrane of the syncytiotrophoblast and cytotrophoblast cells. The x-cells surrounded the fetus in the form of a dipeptidyl peptidase IV-positive shell at the border to the mother. The enzyme represented the first specific marker for x-cells. Dipeptidyl peptidase I and II were primarily found in Hofbauer cells (macrophages) of the villous stroma, but also in the syncytiotrophoblast, other villous stromal cells and cells of the chorionic and basal plate. -Glutamyl transferase was present in some connective tissue elements of the chorionic plate. Oxytocinase and endopeptidases were not detected. Isoclectric focusing of proteases revealed different molecular forms of dipeptidyl peptidase IV in the paraplacenta and villous tree, while the aminopeptidases shared the same pattern in both regions. Immunocytochemical staining of dipeptidyl peptidase IV in the villous tree resembled the pattern obtained by catalytic cytochemistry except for the blood vessel endothelium and the x-cells of the basal plate. Fluorometrically, all proteases were more active in the villous tree than in the paraplacenta. The kinetic measurements revealed the highest hydrolysis rates for dipeptidyl peptidase IV followed by the aminopeptidases. In contrast to eatalytic cytochemistry all proteases were detectable when using fluorometry.Supported by the German Research Foundation (Sfb 174)A preliminary account of this work was presented at a Symposion on Progress in General, Applied and Diagnostic Histochemistry (Smolenice, Czechoslovakia on March 24–28, 1986).     

Histochemical detection of α-d-glucosidases and their molecular forms with 5-Br-4-Cl-3-indoxyl-α-d-glucoside

Summary 5-Br-4-Cl-3-Indoxyl--d-gluco(pyrano)side was found to be the most suitable synthetic substrate for the demonstration of -d-glucosidases in situ. Using an azoindoxyl procedure with hexazotized pararosaniline or new fichsine at pH 5 in freeze-dried celloidine-mounted cryostat sections acid -d-glucosidase (EC 3.2.1.20) was shown for the first time in lysosomes of many cells of fetal and adult rat, mouse, guinea-pig, marmoset and human organs. At pH 6.5, in chloroform-acetone pretreated cryostat sections plasma membrane -d-glucosidases were shown in the brush border of enterocytes of the small and large intestine, in the brush border of proximal renal tubule cells and in the stereocilia of the epididymal duct. In an indigogenic procedure with ferricyanide/ferrocyanide as redox catalysator plasma membrane -d-glucosidases were depicted as well as with the azo-indoxyl method; the demonstration of the acid -d-glucosidase was inferior to that achieved with the azo-indoxyl procedure. Using tetrazolium salts as capture reagent intracellular localization was unsatisfactory. In enterocytes, a localization in the Golgi apparatus was shown by the azo-indoxyl procedure only. Analytical isoelectric focusing revealed organ-dependent differences of plasma membrane and lysosomal -d-glucosidases. Compared with the already existing methods the azo-indoxyl and indigogenic procedures are by far the most suitable techniques.Supported by the German Research Foundation (Sfb 174) and the BMFT (Project CMT 35)     

A new antibiotic combination for frozen bovine semen 1. Control of mycoplasmas, ureaplasmas, Campylobacter fetus subsp. venerealis and Haemophilus somnus

Systematic evaluations of new combinations of antibiotics for the control of bovine mycoplasmas, ureaplasmas, Campylobacter fetus subsp. venerealis and Haemophilus somnus in a bovine frozen semen process were made. These organisms were standardized to 10(5) to 10(6) colony forming unit (CFU) and inoculated into each ml of raw semen. Antibiotics in a final volume of 0.02 ml were added to each ml of the raw semen and were contained at the same concentration in the nonglycerol portion of the extenders (whole milk, 20% egg yolk citrate, 20% egg yolk tris, Plus-X, and 28% egg yolk tris). The combination of gentamicin (500 ug/ml) tylosin (100 ug/ml) and Linco-Spectin (300/600 ug/ml) was more effective for the control of mycoplasmas and ureaplasmas and equally effective for the control of C. fetus subsp. venerealis and Haemophilus somnus than the standard combination of penicillin, dihydrostreptomycin and polymyxin B sulfate.     

The recovery of ureaplasmas from bovine embryos following in vitro exposure and ten washes

Twenty-six unhatched embryos and ova were exposed to Ureaplasma diversum strain 2312 in vitro for 16 h and subsequently washed ten times. Fifteen of the embryos and their wash fluids were cultured for ureaplasmas. Of the remaining 11 embryos, six were incubated with rabbit anti-Ureaplasma immunoglobulin (RAI) and five were incubated with serum from naive rabbits(NRS), after which all were incubated with protein A gold and prepared for electron microscopy. On ultrastructural examination, ureaplasmas were observed on the outer surface of the zona pellucida of all 11 embryos. The ureaplasmas on the six embryos incubated with RAI were labeled with gold particles, while those on the five embryos incubated with NRS were not labeled. Ureaplasmas were recovered from all 15 of the cultured embryos and all of the first and second wash fluids as well as intermittently from the third, fourth, sixth, seventh, eighth and ninth wash but not fom the fifth or tenth wash. It was concluded that viable ureaplasmas adhered to the zona pellucida during in vitro exposure of bovine embryos and were not removed by ten washes.     

Histochemical detection of alpha-D-glucosidases and their molecular forms with 5-Br-4-Cl-3-indoxyl-alpha-D-glucoside

5-Br-4-Cl-3-Indoxyl-alpha-D-gluco(pyrano)side was found to be the most suitable synthetic substrate for the demonstration of alpha-D-glucosidases in situ. Using an azoindoxyl procedure with hexazotized pararosaniline or new fuchsine at pH 5 in freeze-dried celloidine-mounted cryostat sections acid alpha-D-glucosidase (EC 3.2.1.20) was shown for the first time in lysosomes of many cells of fetal and adult rat, mouse, guinea-pig, marmoset and human organs. At pH 6.5, in chloroform-acetone pretreated cryostat sections plasma membrane alpha-D-glucosidases were shown in the brush border of enterocytes of the small and large intestine, in the brush border of proximal renal tubule cells and in the stereocilia of the epididymal duct. In an indigogenic procedure with ferricyanide/ferrocyanide as redox catalysator plasma membrane alpha-D-glucosidases were depicted as well as with the azo-indoxyl method; the demonstration of the acid alpha-D-glucosidase was inferior to that achieved with the azo-indoxyl procedure. Using tetrazolium salts as capture reagent intracellular localization was unsatisfactory. In enterocytes, a localization in the Golgi apparatus was shown by the azo-indoxyl procedure only. Analytical isoelectric focusing revealed organ-dependent differences of plasma membrane and lysosomal alpha-D-glucosidases. Compared with the already existing methods the azo-indoxyl and indigogenic procedures are by far the most suitable techniques.     

Bacterial iturins mediate biocontrol activity of Bacillus sp. against postharvest pear fruit‐rotting fungi

A potential antagonist, Bacillus sp. LYLB4 isolated from pear fruits, was tested for its antifungal activity against postharvest pear pathogens. LYLB4 had a remarkable antifungal effect on Botryosphaeria dothidea. Although it showed a weak inhibition effect on the growth of Rhizopus stolonifer on potato dextrose agar (PDA) plates, LYLB4 almost completely destroyed R. stolonifer during direct contact in potato dextrose broth (PDB). LYLB4 treatment was able to significantly reduce disease incidence (by 68.9% and 100%, respectively) and lesion diameter (by 68.7% and 100%, respectively) of ring rot caused by B. dothidea and soft rot caused by R. stolonifer in pears. LYLB4 also suppressed several other phytopathogens in vitro, suggesting a broad‐spectrum antagonistic activity against fungal pathogens. 16S rRNA and gyrA sequence analysis indicated that LYLB4 is closely related to B. velezensis. Genome mining indicated that LYLB4 had 11 secondary metabolites encoding clusters, but that the surfactin and fengycin gene clusters may not be functional because of a large deletion. Matrix‐assisted laser desorption ionization‐time of flight mass spectra (MALDI‐TOF‐MS) demonstrated that iturins were the major lipopeptides, and that C₁₆/C₁₇ Bacillomycin D synthesis was stimulated when LYLB4 was co‐cultured with B. dothidea compared to the control. Overall, these results demonstrate that the main biocontrol mechanism adopted by LYLB4 could be through the production of toxic metabolites and direct contact with pathogens.     

Three new species of <Emphasis Type="Italic">Anthocephalum</Emphasis> Linton, 1890 (Cestoda: Tetraphyllidea) from dasyatid stingrays of the Gulf of California

Three new species of Anthocephalum Linton, 1890 are described from dasyatid stingrays collected in the Gulf of California. Anthocephalum michaeli n. sp. is described from Dasyatis longus (Garman). This species most closely resembles A. alicae Ruhnke, 1994, but differs from this species in proglottid number. A. lukei n. sp. is also described from D. longus. This new species is most similar to A. cairae Ruhnke, 1994, but differs from that species in marginal loculi number and number of proglottids. The third new species, A. currani n. sp., is described from D. brevis (Garman). This species is most similar to A. centrurum (Southwell, 1925) Ruhnke, 1994, but differs from that species in marginal loculi number, number of testes and ovarian length. Phyllobothrium kingae Schmidt, 1978 is also consistent in morphology with species of Anthocephalum and is transferred to this genus, forming the new combination Anthocephalum kingae n. comb. This species most closely resembles A. michaeli n. sp., but differs in testicular shape. This brings the total number of species of Anthocephalum to nine. The transfer of the species Phyllobothrium arctowskii Wojciechowska, 1991, P. georgiense Wojciechowska, 1991, P. rakusai Wojciechowska, 1991 and P. siedleckii Wojciechowska, 1991 to Anthocephalum is not warranted, as these four species lack a posteriorly recurved cirrus-sac and a sinuous vagina, and have vitelline follicles uninterrupted by the ovary. Of the nine known species, all are parasitic in batoid fishes, and six are found in species of Dasyatis Garman. The phylogenetic status of Anthocephalum species in relationship to Rhinebothroides Mayes, Brooks & Thorson, 1981, Pararhineothroides Zamparo, Brooks & Barriga, 1999 and other rhinebothriin taxa is discussed.     

Cell physiology and protein secretion of Bacillus licheniformis compared to Bacillus subtilis

The genome sequence of Bacillus subtilis was published in 1997 and since then many other bacterial genomes have been sequenced, among them Bacillus licheniformis in 2004. B. subtilis and B. licheniformis are closely related and feature similar saprophytic lifestyles in the soil. Both species can secrete numerous proteins into the surrounding medium enabling them to use high-molecular-weight substances, which are abundant in soils, as nutrient sources. The availability of complete genome sequences allows for the prediction of the proteins containing signals for secretion into the extracellular milieu and also of the proteins which form the secretion machinery needed for protein translocation through the cytoplasmic membrane. To confirm the predicted subcellular localization of proteins, proteomics is the best choice. The extracellular proteomes of B. subtilis and B. licheniformis have been analyzed under different growth conditions allowing comparisons of the extracellular proteomes and conclusions regarding similarities and differences of the protein secretion mechanisms between the two species.