Partial removal of the mesenchyma disrupts the growth and differentiation of the epithelium in respiratory tract explants from strain A and C57BL mouse embryos

Differentiation of respiratory epithelium (E) of 17-day old embryos of A and C57BL mice after partial removal of mesenchyme (M) was studied in organ culture. In control explants, tissue-specific growth and differentiation of epithelium were observed during long-term culturing. Ih both mouse strains, partial removal of mesenchyme prevented the development of alveolar-like structures in explants of distal part of respiratory tract. In most explants of proximal part of respiratory tract (65.1% in A mice and 85.7% in C57BL mice) with partially removed mesenchyme, we found atypical epithelial structures and foci of poorly differentiated cells with high proliferation rate.     

Long-term organ culture of mouse mammary gland

Summary A method for maintaining mouse mammary gland in organ culture for periods of at least 30 days is described. Strips of the number four mammary glands were cultured in individual tubes while fully submerged in Medium 199 supplemented with insulin, aldosterone, ovine prolactin and bovine growth hormone. Exchange processes were aided by slowly rotating the tubes during culture. Mammary tissue from midpregnant BALB/c and virgin GR/A mice was induced to undergo lobulo-alveolar development, secrete and remain differentiated and metabolically active for the period of culture. Cells of both the ductal and alveolar epithelium continued to synthesize DNA and divide. The submerged roller-tube culture allows the use of larger pieces of tissue than can be accommodated in static culture, and the technique may prove applicable to the culture of a variety of tissues.     

Morphogenesis and growth potentials of organ cultures of the respiratory tract anlage of mice susceptible and resistant to pulmonary blastomogenesis

The morphogenesis and growth potencies have been studied in the long-term organ cultures of different parts of the respiratory tract early rudiment in the mouse strains susceptible (A) and resistant (C57BL) against lung blastomogenesis. Similarities and peculiarities have been shown for the lung rudiment cells developing in vitro and in vivo. The linear differences have been established in morphogenesis and growth potencies of the proximal and distal parts of the respiratory tract rudiment. Possible importance of phenotypic differences in realization of the genetically determined sensitivity of the mouse-lung tissue to spontaneous and induced blastomogenesis is discussed.     

Pathogens isolated from patients with community-acquired lower respiratory tract infections

The aim of the study was to assess the prevalence and antimicrobial susceptibility of pathogens in patients hospitalized in Clinic of Pneumology and Alergology University Clinical Hospital No 1 in ?od? in 2006-2008 period, due to community-acquired lower respiratory tract infections. In this samples of sputum, bronchoaspirate and BAL's were evaluated. The most frequent pathogens isolated from all examinated patients were Gram-negative rods. This bacteria were susceptible in most to imipenem (91%), ceftazydym (71%), amikacin (67%), ciprofloxacin (63%) and to amoxicillin with clavulanic acid only in 18%. This study show high prevalence of Gram-negative rods in patients hospitalized due to community-acquired lower respiratory tract infections.     

Mycoplasma felifaucium, a new species isolated from the respiratory tract of pumas

Mycoplasmas isolated from the throats of three pumas (Felis concolor) were each cloned and examined in detail. All three were serologically and biologically indistinguishable from each other, and were serologically distinct from 83 recognized Mycoplasma and Acholeplasma species. They were designated as a new species, Mycoplasma felifaucium, with strain PU (NCTC 11703) as the type strain.     

Preparation,morphology and drug metabolism of isolated hepatocyte and liver organ cultures from the human fetus

Isolated hepatocytes of human fetuses (week 9–20 of gestation) were prepared by digestion of liver slices with Dispase l and repeated centrifugations. These cells metabolized drugs by first order kinetics for at least 4 h and retained their drug metabolizing enzyme activities for more than 24 h. Using cultures of human fetal liver slices (week 5–20 of gestation) first order kinetics of drug metabolism could be measured for up to 3 days. These findings correlate well with concomitant morphological studies. Electron microscopy revealed that the liver cells of human fetuses (week 9–20 of gestation) contained numerous cavities of the rough endoplasmic reticulum (ER) and only single membranes of the smooth ER. The isolated liver cells maintained their morphological integrity for up to 24 h in culture. Sections derived from liver slices cultured for up to 3 days did not show any significant morphological alterations, except for some swellings of mitochondria, vacuolisations and fat inclusions that occurred in the sinus endothelia and blood cells. A gradual disintegration began on day 4, and after 7 days intact cells could no longer be demonstrated. The metabolism of the benzodiazepine drugs prazepam, diazepam and medazepam as well as diphenylhydantoin, hexobarbital and halothane were measured in these systems. Both the isolated hepatocyte and liver organ cultures should be useful to study whether a relationship exists between the emryotoxicity of certain drugs and their metabolism in the human fetus.     

Guanine salvage by organ cultures of mouse tooth germs

The effect of mycophenolic acid (MPA) which inhibits the biosynthesis of guanosine monophosphate (GMP) in organ cultures of mouse tooth germs can be partially counteracted by adding guanine to the MPA cultures. This may be due to salvaging guanine by the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT), or to competition for a common membrane carrier involved in mediated transport of both guanine and hypoxanthine in normal biosynthesis and also of MPA. Experiments were carried out to compare the effect of either hypoxanthine or guanine on the MPA-caused inhibition. While addition of guanine to the MPA cultures (MPAG) supports growth equal to controls and development of dental-enamel junction (DEJ) to a level intermediate between control and MPA the addition of hypoxanthine (MPAHX) supports growth and DEJ development not better than MPA. This indicates that guanine is salvaged by HGPRT to GMP while hypoxanthine, salvaged to inosinic acid (inosinic monophosphate, IMP) is ineffective because the MPA inhibition is on the pathway from IMP to GMP.     

Human skin collagenase: isolation of precursor and active forms from both fibroblast and organ cultures.

Human skin procollagenase has been isolated, in pure form, from the medium of fibroblasts cultured in the presence or absence of added serum. Purification was achieved using a combination of cation-exchange (phosphocellulose or carboxymethylcellulose) and gel-filtration chromatography. Two forms (60 000 and 55 000 daltons) of the procollagenase were detected by electrophoresis in sodium dodecyl sulfatepolyacrylamide gels and could be separated by chromatography on Ultrogel AcA-44. Each form was converted to active enzyme by trypsin, producing species of 50 000 and 45 000 daltons, respectively. An autoactivation process also occurred, which yielded active enzyme without a detectable change in molecular weight. Procollagenase also was found in organ cultures of human skin but only when serum was added to the medium. This suggests that a serum-inhibitable proteolytic system is present in these cultures which, like trypsin, converts procollagenase to the active enzyme forms that can be isolated from serum-free organ culture medium. The collagenase species obtained from either fibroblast or organ culture medium were chromatographically and electrophoretically identical.     

Upper respiratory tract infection in mouse and rats

Summary Spontaneous aspergilloma in the para-nasal cavities of 2 rats, and a chronic granuloma with grains, caused by Gram-positive cocci in the maxillary sinus of a mouse, are reported.     

Elastic fiber formation in monolayer and organ cultures of chondrocytes isolated from auricular cartilage.

Chondrocytes were isolated from auricular cartilage of immature rabbits and maintained in monolayer or organ culture for 14 days. In both types of culture the chondrocytes formed conspicuous elastic fibers. In monolayer culture the fibers could be identified by orcein staining in the culture dish. Electron microscopy of organ cultures revealed the presence of two basic components of elastic fibers, i.e. microfibrils and elastin.     

Nitrosomethylurea disturbs differentiation of mouse embryonic lungs in organ cultures

We have studied the effect of nitrosomethylurea (NMU) on the differentiation of early rudiments of mouse embryonic lungs (12th day of embryogenesis) explanted into an organ culture. We have demonstrated that nontoxic doses of NMU are capable of accelerating normal lung differentiation both at the early (increase in the number of epithelial buds) and at the late (increase in the number of explants with regions of well-developed alveoli) stages of cultivation. However, NMU induces disturbances of differentiation, which appear as polycystic structures and hyperplastic nodules generally absent in the control.     

下呼吸道感染流行菌及其耐药性

目的:研究本院下呼吸道感染流行菌及其耐药性,为合理使用抗生素提供依据.方法:对下呼吸道感染流行菌进行统计分析.结果:检出病原菌716株,革兰阴性杆菌为主要菌种,而G杆菌中铜绿假单胞菌占13.69%,肺炎克雷伯菌占8.8%,不动杆菌属占8.4%.除嗜麦芽寡养单胞菌外,G杆菌对亚胺培南、阿米卡星敏感性高.G 球菌以表皮葡萄球菌、溶血葡萄球菌为主要菌种,耐甲氧西林表皮葡萄球菌(MRSS)的检出率为85.3%,耐甲氧西林溶血葡萄球菌的检出率为91.6%.真菌分离呈增多趋势,占所有病原菌的23.28%.结论:下呼吸道感染流行菌药敏显示耐药水平较多,临床医生应根据药敏结果合理选择抗生素,以利于疾病的治疗.