Wide distribution of a 36-megadalton plasmid among clinical and environmental Spanish isolates ofLegionella pneumophila serogroup 1

With the eventual goal of characterizingLegionella pneumophila serogroup 1 plasmids at the molecular level, we have analyzed the plasmid contents of 78 clinical and environmental Spanish isolates. After selection of a suitable alkaline lysis method, we detected plasmids with approximate molecular weights of 25, 36, 40, 61, 80, 85, 90, and 95 megadalton (MDal). Several factors (i.e., wide temporal and geographic distribution, high frequency in both clinical and environmental isolates, and apparent high copy number after subculturing) make the 36 MDal type IA plasmid an appropriate plasmid for further molecular studies.     

The interval between the diagnosis of malignancy and the development of effusions, with reference to the role of cytologic diagnosis

An analysis was made of the time lapse between the diagnosis of malignancy and the development of an effusion in relation to the sex and age of the patients and the site of the primary malignancy. The total number of patients studied was 254; of these, 171 patients had a pleural and 83 patients a peritoneal effusion. In the total group, sex distribution was two men to three women: about equal in the pleural effusion group and about two men to nine women in the ascites group, with the latter ratio reflecting the large number of primary malignant processes in the breast and ovaries. The average age at the time of the effusion, whether it was located in the pleural or in the peritoneal cavity, was about 55 years. This figure was roughly 60 years for men and 51 years for women. The nine-year average age difference between sexes can be explained by the size of the four largest groups of different primary malignant localizations and their sex distribution. The interval between the discovery of the primary malignancy and the first fluid sample was longer for patients with a pleural effusion (average of 77.0 weeks) than for patients with ascites (average of 54.5 weeks). The longest interval was seen in the breast carcinoma group, with the shortest interval in lung carcinoma patients. The interval was significantly longer for women, being 111.9 weeks for pleural effusions and 57.9 weeks for ascites (average for both sites of 88.7 weeks). In 30.7% of the patients, the primary malignancy was discovered at the same time or later than the effusion; in patients with lung cancer, a strikingly higher percentage of 53.0% was found. In this respect, the cytologic diagnosis of effusions is of great importance not only for the detection and proper identification of a malignant process but also as an indicator of the life expectancy of a patient.     

Cytochemical evaluation of gamma-glutamyl-transpeptidase activity in cervical smears

The cervicovaginal smears of 43 patients attending an outpatient service for early cancer detection were cytochemically studied for the presence of gamma-glutamyl-transpeptidase (GGT) in epithelial cells. This was done in order to evaluate such an enzyme phenotype as a marker for cancer development. The results showed that 70% of the 38 patients with a cytologic diagnosis of "inflammatory" or preneoplastic/neoplastic conditions had GGT-positive cells in their smears. None of the five cytologically normal cases showed any epithelial cells with GGT activity. Although most of the GGT-positive cells were metaplastic, some morphologically normal, dysplastic or neoplastic cells also expressed the enzyme. The data suggest that cytochemically detectable transpeptidase activity appears whenever alterations of the normal epithelial microenvironment occurs, but is not necessarily linked to the carcinogenic process. Therefore, cytochemically GGT-positive cells should not be used as an indicator of neoplastic transformation of the cervical epithelium.     

Duplication of HRAS1, INS, and IGF2 is not a common event in Beckwith-Wiedemann syndrome

A few cases of Beckwith-Wiedemann syndrome (BWS) have in common a duplication of 11p15. Among the genes located in 11p15, c-Ha-ras 1 (HRAS1), insulin (INS), and insulin-like growth factor II (IGF2) may account for the clinical features and the increased risk for malignancy. Using eight 11p15 markers including HRAS1, INS and IGF2 we have studied eight sporadic and hereditary cases of BWS whether or not associated with a nephroblastoma. By gene dosage determination and family studies, we have shown the following: the eight patients examined had an apparent diploid representation of all of the eight markers studied, thus indicating that a microduplication of these markers or of the region characterized by these markers is not a common event in BWS; in a family with three affected sibs the genes for HRAS1 and INS/IGF2 did not cosegregate with BWS and therefore may not participate in the pathogenic processes here observed.     

Effect of some antineoplastics on metabolic heme pathway

1. The porphyrinogenic ability of several antineoplastics used in the therapy of the different cancers was evaluated. The action of cyclophosphamide, busulfan and 5-fluorouracil on the amount and nature of the accumulated hepatic porphyrins and on the activity of delta-aminolaevulinate synthase (ALA-S), were estimated at different doses and times of drug treatment in 17-day-old chick embryos. 2. It was observed that cyclophosphamide produces a significant increase in the accumulation of hepatic porphyrins at different doses as well as in the activity of the ALA-S, at all the incubation times. Cyclophosphamide alters the pattern of porphyrins accumulated in the liver, where a coproporphyrin: protoporphyrin ratio higher than in the controls can be observed. 3. Busulfan increased the hepatic porphyrins accumulated in the liver but to a lesser degree than cyclophosphamide. 4. 5-Fluorouracil did not modify the hepatic porphyrin content when it was administered at doses up to 40 mg/embryo. 5. When the embryos were injected with busulfan or 5-fluorouracil no significant differences were observed in the activity of ALA-S up to 11 hr of incubation. 6. These results indicate that cyclophosphamide has a remarkable porphyrinogenic capacity in chick embryo while busulfan, notwithstanding the fact that it alters the haem pathway, it does so to a degree that does not impair the regulation of ALA-S activity. Fluorouracil seems to be non porphyrinogenic in this system, up to 40 mg/embryo.     

Salivary hormones: a new aspect of oral physiology

Aside from the digestive enzymes the submandibular salivary glands (SSG) synthetize other polypeptides, detected also in saliva, with varied biological activity; NGF and EGF are the knowest. However, over the last decade, steroids hormones have been also found out in the saliva at the same concentrations that the free plasma fraction. The origin of these hormones is largely discussed and certain authors have even proposed a local synthesis for them. This matter, is of clinical interest because gingiva and buccal tissues are knowingly sensitive to steroids. Besides, woman ovulation appears to be monitored through progesterone fluctuations in saliva. Another kind of salivary substances is formed by the neuropeptides of the gut-brain axis, mainly VIP and SRIF. The former likely of nervous origin seems to be involved in the atropine-resistant salivary secretion, whereas the latter-likely of SSG origin--appears as a factor associated with glycemia control.     

A lacZ-pbpB gene fusion coding for an inducible hybrid protein that recognizes localized sites in the inner membrane of Escherichia coli.

An in-phase gene fusion consisting of the 5'-terminal 1,314 base pairs (bp) of the structural gene for beta-galactosidase (lacZ) and the 3'-terminal 1,644 bp of the structural gene coding for penicillin-binding protein 3 (pbpB) of Escherichia coli was constructed and cloned in the plasmid pDIAM64. The product of the fusion gene was a remarkably stable protein with an apparent molecular weight of 110,000 (p110) that retained the ability to covalently interact with beta-lactam antibiotics. The fusion protein was found associated with the membrane at low levels of induction, but it accumulated in the cytoplasm of cells induced for a long time as inclusion bodies of high density. Inclusion bodies were localized at defined positions corresponding to septal sites in all of the pDIAM64-containing strains tested except PAT84 and GD113 (which carry the ftsZ84 mutant allele). These findings indicate a possible role of the FtsZ protein in the integration of Pbp3 into the membrane and in septum localization during the cell division cycle.     

Peptidoglycan biosynthesis in stationary-phase cells of Escherichia coli.

The ability of stationary-phase cells of Escherichia coli W7 to incorporate radioactive precursors into macromolecular murein has been studied. During the initial 6 h of the stationary phase, resting cells incorporated meso-[3H]diaminopimelic acid at a rate corresponding to the insertion of 1.3 X 10(4) disaccharide units min-1 cell-1. Afterwards, the rate of incorporation dropped drastically (90%) to a low but still detectable level. Incorporation during stationary phase did not result in an increased amount of total murein in the culture, suggesting that it was related to a turnover process. Analysis of the effects of a number of beta-lactam antibiotics indicated that incorporation of murein precursors in stationary-phase cells was mediated by penicillin-binding proteins, suggesting that the activity of penicillin-binding protein 2 was particularly relevant to this process.     

Isolation and Characterization of Methanogenic Bacteria from Landfills

Methanogenic bacteria were isolated from landfill sites in the United Kingdom. Strains of Methanobacterium formicicum, Methanosarcina barkeri, several different immunotypes of Methanobacterium bryantii, and a coccoid methanogen distinct from the reference immunotypes were identified.     

Biochemical and functional characterization of three types of coated vesicles in bovine adrenocortical cells: implication in the intracellular traffic

Three populations of pure coated vesicles from adrenocortical cells, differing in their density, i.e., 1.125-1.155, 1.155-1.175, and 1.175-1.210 g/cm3, are obtained after separation on two successive sucrose-2H2O gradients. They are involved in LDL internalization and in the receptor cycle as confirmed by the presence, in each population, of the LDL receptor. Electron micrographs confirm the existence of three homogeneous populations exhibiting the typical polygonal structure of the clathrin coat. They differ in their size distribution (small, congruent to 70-nm diameter; medium, congruent to 90-nm diameter; large, congruent to 110-nm diameter) and in the organization of clathrin and of the coat proteins as evidenced on electrophoreses carried out under nondenaturing and denaturing conditions. Activity measurements of marker enzymes, phosphodiesterase and galactosyltransferase, suggest that medium coated vesicles might originate from plasma membranes and small ones from the Golgi complex. Large coated vesicles exhibit phosphokinase enzyme and substrate polypeptides different from those of the two other populations, tubulins being the preferred kinase substrates for the small and medium coated vesicles. These kinases are autophosphorylating enzymes and are revealed, by nondenaturing electrophoreses, as different high molecular mass complexes in the three populations. Clathrin and coat proteins are not part of these complexes.