Factors controlling fruit set in hermaphroditic plants: Studies with the Australian proteaceae

The number of fruits produced by many hermaphroditic plants is usually far fewer than the number of flowers available for fertilization. There are various possible explanations for the low fruit:flower ratio, some proximate and others ultimate. Recent studies, especially in northern hemisphere systems, have used field experiments to test some of them, but there are potential difficulties with the methodology of some experiments and with the testing of ultimate hypotheses. It is important to examine the possible explanations for low fruit: flower ratios with a range of different systems. This article reviews studies on Australian species of woody, perennial shrubs in the family Proteaceae; this evolutionarily distinct group of plants and pollinators has several unusual and interesting characteristics, and provides a valuable addition to the better-known northern hemisphere studies.     

Dietary unsaturated fatty acids: interactions and possible needs in relation to eicosanoid synthesis

In addition to providing energy and essential fatty acids, dietary fatty acids can affect numerous biochemical and physiologic reactions related to secretory, cardiovascular, and immune functions. The major dietary unsaturated fatty acid, linoleic acid, affects tissue arachidonic acid and can influence eicosanoid-mediated reactions. Chronic, excess, or imbalanced eicosanoid synthesis may be conductive to excessive inflammation, thrombotic tendencies, atherosclerosis, and immune suppression. Dietary n-3 polyunsaturated fatty acids (PUFAs) may ameliorate eicosanoid-related phenomena by reducing tissue arachidonic acid and by inhibiting eicosanoid synthesis. This review summarizes information concerning the metabolism of unsaturated fatty acids, with emphasis on tissue arachidonic acid levels and eicosanoids, and discusses the need for data concerning the appropriate intake of dietary n-6 and n-3 PUFAs to modulate arachidonic acid and eicosanoid synthesis and to minimize possible adverse reactions.     

A novel glycosyl-amino acid linkage: rabbit-muscle glycogen is covalently linked to a protein via tyrosine

A recent review summarizes our identification in rabbit-muscle glycogen of a protein that resists all attempts at removal by means that should displace non-covalently bound protein [Kennedy et al. (1985) In Membranes and Muscle (Berman, M.C., Gevers, W. and Opie, L.H. eds.) pp. 65-84, ICSU Press/IRL Press, Oxford]. Here we confirm that the glycogen is covalently bonded to the protein and report that the attachment is via a novel glycosidic linkage involving the hydroxyl group of tyrosine.     

Dipstick haematuria and bladder cancer in men over 60: results of a community study.

OBJECTIVE--To investigate the prevalence and relevance of dipstick haematuria in a group of men in the community. DESIGN--Prospective study of elderly men invited to attend a health centre for urine screening as part of a health check. SETTING--An inner city health centre in Leeds. SUBJECTS--578 Of 855 men aged 60-85 responding to an invitation to participate. INTERVENTIONS--The subjects had their urine tested with a dipstick (Multistix) for the presence of blood and then tested their urine once a week for the next 10 weeks. Those with one or more positive test results were offered full urological investigation. MAIN OUTCOME MEASURE--The prevalence of urological disease in those subjects with dipstick haematuria. RESULTS--78 Men (13%) had dipstick haematuria on a single test and a further 54 (9%) had evidence of dipstick haematuria when testing their urine once a week during a subsequent 10 week period. Investigation of 87 men disclosed urological disease in 45, including four with a bladder tumour and seven with epithelial dysplasia. CONCLUSION--Dipstick haematuria is a common incidental finding in men over 60 and is associated with appreciable urological disease. The introduction of less invasive methods of investigation, particularly flexible cystoscopy and ultrasonography, has made investigation of these patients simple and safe and makes screening for bladder cancer in the community more feasible.     

Analysis of E1A-mediated growth regulation functions: binding of the 300-kilodalton cellular product correlates with E1A enhancer repression function and DNA synthesis-inducing activity.

Adenovirus E1A transforming function requires two distinct regions of the protein. Transforming activity is closely linked with the presence of a region designated conserved domain 2 and the ability of this region to bind the product of the cellular retinoblastoma tumor suppressor gene. We have investigated the biological properties of the second transforming region of E1A, which is located near the N terminus. Transformation-defective mutants containing deletions in the N terminus (deletion of residues between amino acids 2 and 36) were deficient in the ability to induce DNA synthesis and repress insulin enhancer-stimulated activity. The function of the N-terminal region correlated closely with binding of the 300-kilodalton E1A-associated protein and not with binding of the retinoblastoma protein. These results indicate that transformation by E1A is mediated by two functionally independent regions of the protein which interact with different specific cellular proteins and suggest that the 300-kilodalton E1A-associated protein plays a major role in E1A-mediated cell growth control mechanisms.