Aggregative adherence fimbriae I of enteroaggregative Escherichia coli mediate adherence to HEp-2 cells and hemagglutination of human erythrocytes

Strains of enteroaggregative Escherichia coli (EAggEC) have been implicated in several studies as important agents of persistent diarrhea among infants in the developing world. We have previously shown that the aggregative adherence (AA) property of EAggEC is associated with the presence of a 60-MDa plasmid which confers AA when introduced into E. coli HB101. Here, we report the cloning of the AA determinant from EAggEC strain 17-2 into the 21.5-kb cosmid vector pCVD301. TnphoA mutagenesis of the AA cosmid clone pJPN31 implicated an AA region of approximately 12 kb. Transmission electron microscopy of HB101 (pJPN31) revealed the presence of bundle-forming fimbriae, which were absent in AA- TnphoA insertion mutants. The presence of these fimbriae, AA, and hemagglutination (HA) of human erythrocytes were all concurrently lost by single-insertion mutations. A 14-kDa protein was seen on polyacrylamide gel electrophoresis and Western blotting (immunoblotting) of surface shear preparations from fimbriated clones. Twelve of nineteen volunteers fed EAggEC 17-2 developed rises in antibodies to the 14-kDa protein as determined by Western blot. We have termed the cloned bundle-forming fimbriae aggregative adherence fimbriae I (AAF/I); positivity with a previously described EAggEC probe and human erythrocyte HA appear to correlate with the presence of AAF/I.

Identification and partial purification of a thiol endothelin-converting enzyme from porcine aortic endothelial cells

Endothelin is a potent peptide vasoconstrictor. The final step in the processing of endothelin has been postulated to be the cleavage of the Trp21-Val22 peptide bond in proendothelin by a putative endothelin-converting enzyme. A soluble extract of primary porcine aortic endothelial cells was found to contain an enzyme activity that converted proendothelin-1 (proET-1) to an endothelin-1 (ET-1)-like peptide as determined by the rabbit aortic ring contraction assay. This enzyme was partially purified by DE52 ion-exchange chromatography. Incubation of proET-1 with the partially purified enzyme generated a product which had a retention time on HPLC identical to that of authentic ET-1. Further analysis of the product showed that it caused contraction of rabbit aortic rings, had a molecular weight identical to ET-1 as measured by fast atom bombardment mass spectrometry, and competed for [125I]ET-1 binding in an RIA using specific antibodies which recognize the carboxy terminal tryptophan of ET-1. The enzyme activity could be inhibited by thiol protease inhibitors such as Z-phe-pheCHN2 and p-hydroxymercuribenzoate, but not by serine- or metalloprotease inhibitors. The optimal pH for the enzymatic activity was between 7.0 and 7.5, and no activity was detected at pH 4.0. These results demonstrate that this thiol protease is a potential endothelin-converting enzyme.

Intermixing of resident Golgi membrane proteins in rat-hamster polykaryons appears to depend on organelle coalescence

We have used the synchronized formation of a mixed cytoplasm upon heterokaryon formation as a model for investigating the cisternal-specific transport of resident proteins between neighboring Golgi apparatus. Rat NRK and hamster 15B cells were fused by UV-inactivated Sindbis virus and then incubated for various time periods in the presence of cycloheximide. The resident Golgi apparatus proteins, rat GIMPc and Golgp 125, were localized with species-specific monoclonal antibodies. Immunofluorescent colocalization of rat and hamster Golgi membrane proteins was observed with a t1/2 of 1.75 h at 37 degrees C. Colocalization of resident, but not transient, Golgi membrane protein was concomitant with formation of a large extended Golgi complex and was accompanied by the acquisition of endoglycosidase H resistance by preexisting Golgp 125. Dispersal of the extended Golgi complex by nocodazole revealed that colocalization of resident Golgi proteins was due to intermixing of proteins in the same Golgi element rather than overlapping of closely apposed Golgi structures. Incubation of the polykaryons at 20 degrees C inhibited both the colocalization of GIMPc and Golgp 125 and the formation of an extended Golgi complex. Little change in the number of cisternae/stack in cross sections of the Golgi apparatus was observed upon cell fusion, and in the extended Golgi complex the hamster resident protein remained localized to one side of the Golgi stack. Surprisingly, the morphological identity of the rat and hamster Golgi units appeared to be maintained in the heterokaryons. These results suggest that the intermixing of resident Golgi membrane proteins requires direct physical continuity between Golgi elements and that resident Golgi membrane proteins are preferentially excluded from the non-clathrin-coated transport vesicles budding from Golgi cisternae.

[Bullous retinal detachment and its classification of fluorescence angiography]

Nineteen cases with (27 eyes) of bullous retinal detachment, male (24 eyes), female (3 eyes), were reported. The age of onset was from 16 to 46, mean 36.7. All of them underwent fundus fluorescence angiography (FFA). According to the results of FFA, it could be divided into two types of fluorescence angiograph changes were seen: type I, multiple pigmental epithelial damage at posterior pole, it consisted of twelve cases (16 eyes); type II, extensive pigmental epithelial damage at posterior pole, it consisted of seven cases (11 eyes). The treatments consist: medicine; medicine and photocoagulation; combined medicine, transscleral drainage and photocoagulation. Among 27 eyes, 20 had their vision improved after treatment, 4 eyes unchanged and 3 eyes decreased in vision. 22 eyes obtained their retinal reattachment (81.4%). The diagnosis, differential diagnosis, classification and treatment are discussed.

Incidence and mortality rates of myocardial infarction in Chinese workers aged 40-59 in relation to coronary risk factors. Results of a Chinese prospective study (Wuhan Study) in comparison to the Göttingen Risk Incidence and Prevalence Study (GRIPS)

Some 2045 male Chinese industrial workers aged 40-59 years living in the city of Wuhan in the People's Republic of China were examined for coronary risk factors in the year 1983. The investigation included a patient history, clinical examination, and ECG and laboratory tests, with special attention to serum lipids. After 5 years, a follow-up investigation of the study group was carried out. The results were compared to the similarly designed German GRIPS project. In comparison to the German population, significantly lower levels for total-, LDL-, and VLDL-cholesterol, apolipoprotein B, triglycerides, uric acid, body mass index, and diastolic blood pressure were found in China. The percentage of smokers, however, was remarkably higher in China than in the Federal Republic of Germany. During the 5 year observation period in the Chinese sample, four subjects suffered from sudden death and four from nonfatal myocardial infarction; in the German study group three times as many fatal myocardial infarction and cases of sudden death and 7.5 times as many nonfatal myocardial infarctions were recorded. Nonfatal coronary heart disease and peripheral vascular disease were also observed less often in China. The incidence of cerebrovascular diseases was 1.5 times higher in China than in Germany. Whereas in Germany, total-, and LDL-cholesterol values were the major distinguishing parameters between infarction and reference groups, in China these values have thus far had no significant influence on the level of risk. Instead in the Chinese incidence group, significantly higher levels for blood pressure, body mass index, uric acid, and the ratio LDL/HDL-cholesterol were found.

[Inhibitory effect of bleomycin A6 on human colon cancer xenografts in nude mice]

As evaluated by clonogenic assay, bleomycin A6 was found to be highly active against established human cancer cell lines derived from colon cancer (HT-29) and cecum cancer (Hce-8693). These human cancer cells have been serially transplanted in nude mice. At a tolerable dosage level, bleomycin A6 exerted remarkable growth inhibition on human colon cancer HT-29 and cecum cancer Hce-8693 xenografts (approximately 90% inhibition). No histopathological changes were found in the organs of treated animals. Compared on the basis of equitoxic doses (1/9 LD50), bleomycin A6 exerted much stronger growth inhibition against colon cancer HT-29 xenografts in nude mice than 5-fluorouracil and mitomycin C, with inhibition rates of 82%, 12% and 53%, respectively. More extensive necrosis was found in tumors treated with bleomycin A6 than in those treated with mitomycin C or 5-fluorouracil. The ratio values of non-necrotic tumor tissue to whole tumor tissue for bleomycin A6, mitomycin C and 5-fluorouracil were 0.33, 0.65 and 0.57, respectively. These observations indicate that bleomycin A6 is a potent antitumor agent against colon cancer xenografts and may be useful in human colon cancer chemotherapy.

A case of testosterone-secreting adrenal cortical adenoma with spironolactone body-like inclusion

Testosterone-secreting adrenal adenoma is rare. We recently experienced a 17-year-old pubertal girl who showed signs of virilization and a high serum level of testosterone. The excised adrenal gland showed a 3.5 x 3 x 3-cm cortical adenoma. Light and electron microscopic findings together with the high serum level and high tumor tissue contents of testosterone and dehydroepiandrosterone (DHA) indicated that the tumor was a testosterone-secreting adrenal cortical adenoma. This appears to be a rather rare tumor from a review of the literature. Interestingly, in this case, the cytoplasm of the tumor cells contained structures resembling spironolactone bodies. From the results of enzyme histochemistry, the steroidogenetic pathways in this tumor were speculated.

Relation between the therapeutic effect of moxibustion in treating arthralgia and SP and enkephalin in nervous tissues

Moxibustion can accelerate the relief of arthralgia of rats suffering from adjuvant arthritis. At the same time, it promotes the recovery of SP in the sciatic nerve, and maintains SP and leu-enkephalin at a higher level in the lumbar spinal cord. The results show that the therapeutic effect of moxibustion in treating arthralgia bears some relation to activating the spinal enkephalin system and modulating the function of primary afferent neurons.