Benzene and the risk of non-Hodgkin lymphoma: A review and meta-analysis of the literature

Benzene, an accepted leukemogen, has been suggested to cause other hemato- and lymphopoietic cancers. Here we review the published literature for non-Hodgkin lymphoma (NHL) and occupational exposure to benzene. Six cohorts, sixteen case–control studies and two studies of other designs were identified through keyword searches of bibliographic databases. Twenty-two of twenty-four studies found no association between NHL and ever exposed to benzene compared to never; a random-effects meta-analysis gave a pooled risk estimate of 1.11 (95% confidence interval 0.94–1.30). Our finding of no effect agrees with one of two previous meta-analyses. The other meta-analysis examined if high benzene exposure increased NHL risk but a lack of consistent exposure categories within the same metric should have precluded pooling risks by exposure level. Instead, we reviewed whether dose–response relationships existed. The best available data came from six studies where exposure was estimated from historical measurements and on the whole, no trends in risks of NHL with rising cumulative, average, peak, or duration of benzene exposure were found. NHL is a heterogeneous group of malignancies and although less well-studied, benzene was not associated with any NHL subtype. In conclusion, benzene at either low or high doses does not increase the risk of NHL.     

GPC phosphodiesterase and phosphomonoesterase activities of renal cortex and medulla of control, antidiuresis and diuresis rats

Glycerylphosphorylcholine (GPC) concentration was reported to be elevated in renal medulla of experimental animals deprived of water. The activities of GPC phosphodiesterases were similar in homogenates and membrane subfractions of renal cortex prepared from control, diuresis and antidiuresis rats. There were no differences in these preparations' ability to hydrolyze phosphorylcholine. In contrast, there was a nearly 50% reduction of non-specific phosphomonoesterase activity, using p-nitrophenylphosphate as substrate and membrane subfractions prepared from the antidiuresis animals. It is suggested that as a consequence, a pathway for the formation from L-alpha-glycerylphosphate is activated.     

Effects of Prolonged Depolarization on the Nicotinic Acetylcholine Receptors of PC12 Cells

To determine whether prolonged depolarization and/or changes in intracellular Ca2+ concentrations stimulate adaptive responses of neuronal nicotinic acetylcholine receptors, PC12 pheochromocytoma cells were grown in medium containing various concentrations of K+. Nicotinic receptor function was determined as carbachol-stimulated uptake of 86Rb+. Cells were exposed to 50 mM K+ for up to 4 days and then allowed to repolarize for 60 min. Under these conditions, no changes in basal or carbachol-stimulated uptake of 86Rb+ were observed. Furthermore, neither the time course of carbachol-stimulated uptake or the carbachol concentration dependence of 86Rb+ uptake was altered. Finally, concurrent depolarization did not affect the functional down-regulation produced by chronic exposure of the cells to carbachol. Thus, neuronal nicotinic acetylcholine receptors on PC12 cells do not appear to be regulated by depolarization or prolonged elevation of the intracellular Ca2+ level.     

Larviposition response ofBonnetia comta [Dipt.: Tachinidae] to a kairomone ofAgrotis ipsilon [Lep.: Noctuidae]

A kairomone in the frass and vomitus of larvae ofAgrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) triggered larviposition activity in its habitual parasitoidBonnetia comta (Fallen) (Diptera: Tachinidae). Laboratory bioassays showed that no measurable differences existed in the larviposition-stimulating activity of frass fromA. ipsilon larvae reared on 3 different food sources. In other tests, corn seedlings damaged by late-instar larvae ofA. ipsilon elicited strong larviposition activity inB. comta; other corn seedlings damaged with a razor blade did not elicit strong activity. Frass aged for 8-days was only slightly less effective at releasing a larviposition response when compared to fresh frass.B. comta was not stimulated to larviposit by oven dried frass or an India ink dot the color and shape of a fresh pellet from a host larva. The host habitat location and host finding process forB. comta and other tachinid species that deposit free-living maggots is discussed.     

Carcinogenic N-hydroxylaminopurine derivatives do not act as base analog mutagens in Salmonella typhimurium

N-Hydroxylaminopurines are highly mutagenic for growing as well as resting Salmonella typhimurium strain TA100 and to a lesser extent for strain TA98. Aminopurines, under similar conditions, are not mutagenic. N-Methylhydroxylaminopurine, under similar conditions, exhibits only minimal activity. The results are taken to indicate that unlike non-hydroxylated aminopurines, N-hydroxylaminopurines exert their mutagenicity not by acting as base analogs but by direct covalent binding with DNA-guanine.     

Individuals and society in anthropological theory

Conclusion Though relatively little direct attention has been given by Marxist anthropologists to a theory of individual behavior and thought in relation to societal processes, the above partial summary indicates the wealth of insight that is available for elaborating such a theory. In addition, there are of course significant developments in the field of psychology, notably the attention to activity as central to individual personality [], the renewed concern with levels of integration theory [], and the burgeoning interest in Vygotsky's writings on language, thought, and culture []. There are also the continuing attempts to locate Freud's positive contributions in a historical materialist frame [].Where, then, is psychological anthropology? As always, producing a richness of suggestive materials — such as those on varying conceptions of the self — but, as a glance at the pages of Ethos will show, unfortunately not engaged in fundamental theoretical innovation. By way of illustration, let me cite Spindler's The Making of Psychological Anthropology, a collection of articles by major figures, past and present. Spindler's introductory essay is thoughtful; always the teacher, he presents with consideration and modesty the history of the field, the disfavor into which it fell (in large part due to the methodlogical travesties of national character studies), and its stubborn persistence (following from the pervasive interest in the psychological dimension that has always characterized cultural anthropology). He summarizes ongoing problems as perceived from within the field, and as the major difficulty to be overcome pinpoints cultural overdeterminism and its inadequacy for explaining variations. The solution? Not the necessity of respecting history and focussing on how individuals variously understand and relate (according to their individual histories) to the established structures whereby particular societies produce, allocate, and consume basic goods, and how they variously respond to disjunctions in these structures even as they reproduce them. Instead Spindler writes, ... if we are to escape the double bind of our cultural overdeterminism, we are going to have to go beyond culture and even ecology, to biochemistry, to physiology and neurology, to genetics — to biology in the broadest sense of the term [].In closing, let me say to the reader, do not simply turn away in dismay. One must conclude that it is imperative to continue to build a solid alternative theory of relations among individual behaviors, individual understandings, cultural values, and societal processes, or, in other words, to replace a non-historical and essentially biological paradigm with a dialectical and materialist view of human action.Eleanor Leacock is Professor of Anthropology and Chair at the City College, City University of New York.

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Studies of a spring phytoplankton bloom in an enclosed experimental ecosystem. I. Biochemical changes in relation to the nutrient chemistry of water

A spring bloom of diatoms which occurred in large enclosed ecosystem bags at Loch Ewe, Scotland, during 1980, has been the subject of a chemical study. Changes observed in the general biochemical composition of the diatoms during the bloom are compared with the species distribution and changes in the nutrient chemistry of the bag water. The results indicate that major changes in cell biochemistry are associated with the growth, development, and decay of a diatom bloom, particularly if one or more nutrients become limiting.