Synthetic human beta-globin 5'HS2 constructs function as locus control regions only in multicopy transgene concatamers.

Transgenes linked to the beta-globin locus control region (LCR) are transcribed in a copy-dependent manner that is independent of the integration site. It has previously been shown that the LCR 5'HS2 region does not require its NF-E2 dimer binding site for LCR activity. In this paper we analyse synthetic 5'HS2 core constructs containing point mutations in the other factor binding sites 3' of the NF-E2 dimer site. The results show that 5'HS2 core is a partially active LCR that functions in a concatamer of at least two copies but not when present as a single copy in transgenic mice and that no single binding site within 5'HS2 is required for position-independent expression. In addition, the H-BP factor is identical to upstream stimulatory factor (USF) and full enhancement levels by 5'HS2 core in MEL cells require a combination of all the factor binding sites. We suggest that 5'HS2 cores in a concatamer interact with each other to establish an area of open chromatin and that this process may be the basis of LCR function.     

Subgrouping of bacterial populations by cellular fatty acid composition

Abstract The cellular fatty acid composition of six bacterial species isolated from the seeds and leaves of sugar beet ( Beta vulgaris ) and from soil were analysed. The quantitative data from the fatty acid methyl ester (FAME) profiles were highly reproducible. Numerical analysis of Xanthomonas maltophilia . FAME profiles sub-grouped strains according to when they were isolated in the growing season. The analytical method used was sensitive enough to differentiate strains of Klebsiella terrigena isolated from either soil or leaves. The results from this study confirm reports that analyses of bacterial FAME composition were rapid to perform, specific and allowed differentiation of strains within the same species.     

Use of tumour marker immunoreactivity to identify primary site of metastatic cancer.

OBJECTIVES--To determine whether variations in the expression of tumour related antigens can predict the origin of tumours. DESIGN--Immunohistological study of tumour marker expression in primary adenocarcinomas and respective metastatic deposits. Antibodies to the following tumour markers were used: polymorphic epithelial mucin (NCRC-11 and SM3), carcinoembryonic antigen, carcinoembryonic antigen with non-specific antigen co-specificity, CA125, CA19.9, prostate specific antigens, and thyroglobulin. SETTING--Histopathology department of teaching hospital. SUBJECTS--100 pathology sections of metastatic adenocarcinoma and their related primary tumours. MAIN OUTCOME MEASURES--Concordance of reactivity between primary and metastatic tumours. Reactivity profiles of tumour sites. RESULTS--The correct primary site of origin was predicted in 70% (33/47) of tumours in men and 54% (27/43) tumours in women with antibodies SM3, 288, CA19.9, CA125, and PSA (men only). Specificities ranged from 68% for breast tumour to 98% for prostate tumour. CONCLUSION--Use of tumour markers in patients presenting with metastatic adenocarcinoma of unknown origin can help localise the probable primary sites and reduce the need for extensive and expensive imaging techniques.     

Investigations on theSphaerotilus-Leptothrix group

Thirty-fourSphaerotilus andLeptothrix strains were isolated from sewage, activated sludge and iron-containing ditch- and well-water, and their morphological and physiological characters studied. The organisms were grown under different conditions, e.g. on peptoneglucose agar and yeast-extract-manganous-carbonate agar, and in running ditch-water containing ferrous iron. Growth of these bacteria in synthetic media, with glucose as carbon source and aspartic and glutamic acids or inorganic nitrogen compounds as nitrogen source, required added vitamin B₁₂ unless nitrogen was supplied as hydrolyzed casein or as a mixture ofl-amino acids. Methionine was found to be responsible for this replacement of vitamin B₁₂.Five different types of sheath-forming bacteria were distinguished in the present study. Type I is the typical sewage organismSphaerotilus natans. It has large cells, grows well with relatively high concentrations of organic substrates, but cannot oxidize manganous compounds. In running ditch-water containing ferrous iron, ferric hydroxide may be deposited in and on its sheaths. AlthoughS. natans under such conditions may resemble the iron bacteriumLeptothrix ochracea, it has relatively long sheaths, partly filled with cells in contrast with the short and mostly empty sheaths of the latter.S. natans could be readily reisolated from its iron-bacterium cultures but very seldom from crude cultures ofL. ochracea; thus the two organisms are clearly different. Types II and III have relatively large cells, respond poorly to organic nutrients, but are able to oxidize manganous compounds. Type II forms fungus-like flocks in liquid media and resembles microscopicallyL. lopholea, with which it may be identical. Type III resemblesL. ochracea more closely than does any other type, but is probably not identical with it; the nameL. pseudo-ochracea sp.n. is proposed for this type. Type IV is intermediate between types I and V. In media with relatively high concentrations of organic nutrients it behaves like a sewage organism, but in poor media containing ferrous and manganous compounds, it behaves like an iron bacterium, depositing large amounts of ferric and manganic oxides in and on its sheaths; for this type the nameL. cholodnii sp.n. is proposed. Type V has small cells, grows poorly in all media tested, but actively oxidizes manganous compounds; the nameLeptothrix discophora is reserved for this type.The globular inclusions in the cells ofS. natans and other members of theSphaerotilus-Leptothrix group consist of poly--hydroxybutyrate.