The trade in human liver lobes: bioviolence against organ sellers in Bangladesh

The rapid growth in organ transplantation has created an illicit trade in human organs. The kidney trade has flourished in the last few decades, but in the last few years this has been coupled with an emerging liver trade. This article examines the liver trade sourced from poor sellers in Bangladesh. Through ethnographic fieldwork, I investigate how a landless farmer and a village housewife both sell their liver lobes on the black market, and how the recipients undergo liver transplants in Bangladesh and India. I reveal that liver selling, like kidney selling, is primarily driven by the sellers’ debt. What is surprising, though, in this anthropological analysis is that microcredit, a Nobel Prize-winning economic operation, has negatively contributed to organ selling in Bangladesh. I discover that the liver trade leads to tragic outcomes for both sellers and recipients: the sellers could not repay their loans by selling a liver lobe, while one of the recipients died just over a month after the surgery. I therefore argue that liver trade is advancing through a series of disturbing ironies, resulting in bioviolence, exploitation, and suffering for the vulnerable victims.     

Sacrifice, Plants, and Western Pharmaceuticals: Money and Health Care in Northern Ghana

In this article I discuss the role of money vis-à-vis health care among the Dagomba, an agrarian people living in northern Ghana, whose pluralistic medical culture involves the use of both plants and Western pharmaceuticals in the treatment of various symptoms. In Dagomba society monetary exchanges in the domain of healing cannot be equated with self-interest, and nonmonetary exchanges cannot be compared with altruism in any straightforward fashion. Exchanges and their purposes are made meaningful by the contexts in which they occur. Exchanges may involve money and be commoditized. However, the very fact that such an exchange is made in a "benevolent and considerate manner" (which often means selling/buying on credit) transforms otherwise impersonal relationships between medicine sellers and their customers into displays of solidarity with the communal (collective) goals of Dagomba society.     

Regulation of renal and lower gastrointestinal function: role in fluid and electrolyte balance

For the majority of vertebrates, the kidneys are not the sole organs that function to maintain homeostasis of body fluid and electrolytes. Mammals are unusual in this respect, as the kidneys are the organs that fill this role. For non-mammalian vertebrates, other organs such as gills, skin, salt glands, urinary bladders and the gastrointestinal (GI) system function in concert with the kidneys in the control of fluid and ion balance. Birds are of particular interest and unique as they do not possess a urinary bladder and the renal output enters the lower GI tract. The physiology of the interaction of avian kidneys and lower GI tract is an excellent example of integrative physiology and several aspects of it have been examined, for example, the role of the avian antidiuretic hormone (arginine vasotocin, AVT) in controlling renal output. AVT produces both a tubular and glomerular antidiuresis. The glomerular antidiuresis is important, as the fluid from the kidneys that enters the GI should not be highly concentrated. Another hormone, aldosterone, has been shown to play an important role in regulating the transport of sodium by the GI epithelium. In addition, the lower GI tract plays a significant role in recycling a portion of the nitrogen that leaves the kidneys as uric acid. Furthermore, the output of avian kidneys contains large amount of protein that is conserved by the lower GI tract.     

Effective altruists ought to be allowed to sell their kidneys

Effective altruists aim to do the most good that they can do with the resources available to them, without causing themselves or their dependents significant harm thereby. The argument presented in this paper demonstrates that there are no morally relevant dissimilarities between living kidney donation and living kidney selling for effective altruistic reasons. Thus, since the former is allowed, the latter ought to be allowed as well. And, there are important moral differences between living kidney selling for effective altruistic reasons and other reasons for kidney vending (e.g., for personal financial gain), such that standard objections against markets in human kidneys do not attach to those markets designed around principles of effective altruism. The reasonable conclusion to draw from this is that eligible effective altruist kidney donors ought to be allowed to sell (one of) their kidneys to others in need, if they so desire. Because of this, law and policy ought to be changed to allow for this exceptional case: current laws that ban kidney selling for everyone, irrespective of their reason for selling, are unjustified.     

A fundamental symmetry between morphogenesis and function of branched organs]

It is generally difficult to find any relationship between the morphogenesis of an organ and its final function. A priori, such a relationship has no reason to exist, since organs do not actually function during their formation. I will show in this article that, for a very large class of organs--the branched organs--there exists a hidden relationship between their morphogenesis and their function. This class of organs comprises: the lungs, the salivary mammary and lacrymal glands, the kidneys, the pancreas, and possibly other organs, such as testes. For all these organs, a fundamental fact that comes from recent developments in physics explains at the same time how they form, and why they work. This suggests, first, that complex organs are not the result of gradual and long selection processes, and, second, that this specific structure for the organs is imposed by the laws of physics. The growth process, as described here, is possibly the only one that allows both to build a fluid-secreting organ, and make it work.     

Strategic ethnic performance and the construction of authenticity in urban Japan

This paper introduces the concept of strategic ethnic performance (SEP), when members of one ethnic group present themselves as members of a phenotypically similar ethnic group for economic gain. I use ethnographic and interview data focused on Sub-Saharan African merchants involved in the Hip Hop fashion boutique business in urban Japan to show how SEP develops from four interconnected areas: the opportunity structure for ethnic entrepreneurs, the physical presentation of sellers, the arrangement of the selling venue, and feedback loops between the seller and the consumer. By utilizing SEP, ethnic entrepreneurs enhance the perceived authenticity of their goods and themselves. A thorough analysis of this process illuminates the interactional nature of ethnic authenticity as it is understood by consumers within urban areas.     

Mesenteric Organ Production, Hepatic Metabolism, and Renal Elimination of Norepinephrine and Its Metabolites in Humans

Abstract: This study used regional differences in plasma concentrations of norepinephrine and its metabolites to examine how production of the transmitter by sympathetic nerves, in particular, those innervating mesenteric organs, is integrated with metabolism by the liver and elimination by the kidneys. Higher concentrations of norepinephrine, its glycol metabolites 3,4-dihydroxyphenylglycol and 3-methoxy-4-hydroxyphenylglycol and their sulfate conjugates in portal venous than arterial plasma indicate substantial production of norepinephrine by mesenteric organs (15.5 nmol/min). Much lower concentrations of norepinephrine and its glycol metabolites in plasma leaving than entering the liver indicate their efficient hepatic removal (20 nmol/min). Higher concentrations of vanillylmandelic acid in the hepatic outflow than inflow indicate that this metabolic end product is produced largely from the norepinephrine and glycol metabolites removed by the liver. Renal elimination of vanillylmandelic acid (18–20 nmol/min), produced mainly by the liver (17 nmol/min), and of 3-methoxy-4-hydroxyphenylglycol sulfate (7–9 nmol/min), produced largely by mesenteric organs (7 nmol/min), comprised 86–91% of the total renal elimination of norepinephrine metabolites. The results show that mesenteric organs produce about one-half of the norepinephrine formed in the body. The liver removes substantial amounts of circulating norepinephrine and its glycol metabolites and converts these compounds to vanillylmandelic acid, which is then eliminated from the body by the kidneys. The sulfate conjugates are also metabolic end products eliminated by the kidneys. However, these metabolites are produced by extrahepatic tissues, in particular, mesenteric organs, which represent a significant source of sulfate-conjugated norepinephrine and 3,4-dihydroxyphenylglycol, and the main source of sulfate-conjugated 3-methoxy-4-hydroxyphenylglycol.     

Preferential accumulation of radioactivity in rat kidneys after the administration of 125I-labelled Fab antidigitalis antibodies

125I-labelled Fab antidigitalis antibodies were administered i.p. to rats, whose organs were removed 20 h later and examined for radioactivity. Maximum radioactivity was found in the thyroid region, followed by the kidneys, liver, adrenals, heart, skeletal muscle and brain. The radioactivity of kidneys was greater than in any of the other organs except the thyroid, where it probably resulted from the uptake of radioiodine, released from the antibodies. After injection of Na125I there was no difference between the kidneys and the liver. In kidney homogenates, radioactivity was present both in the 100,000xg pellet and in the supernatant. The possibility of accumulation or production of the endogenous digitalis-like factor in the kidneys is discussed.     

Actions and interactions of growth hormone and insulin-like growth factor-II: body and organ growth of transgenic mice

To characterize long-term actions and interactions of growth hormone (GH) and insulin-like growth factor-II (IGF-II) on postnatal body and organ growth, hemizygous phosphoenolpyruvate carboxykinase (PEPCK)-human IGF-II transgenic mice were crossed with hemizygous PEPCK-bovine GH transgenic mice. The latter are characterized by two-fold increased serum levels of IGF-I and exhibit markedly increased body, skeletal and organ growth. Four different genetic groups were obtained: mice harbouring the IGF-II transgene (I), the bGH transgene (B), or both transgenes (IB), and non- transgenic controls (C). These groups of mice have previously been studied for circulating IGF-I levels (Wolf et al., 1995a), whereas the present study deals with body and organ growth. Growth curves (week 3 to 12) were estimated by regression with linear and quadratic components of age on body weight and exhibited significantly (p < 0.001) greater linear coefficients in B and IB than in I and C mice. The linear coefficients of male I and C mice were significantly (p < 0.001) greater than those of their female counterparts, whereas this sex-related difference was absent in the bGH transgenic groups. The weights of internal organs as well as the weights of abdominal fat, skin and carcass were recorded from 3.5- to 8- month-old mice. In addition, organ weight-to-body weight-ratios (relative organ weights) were calculated. Except for the weight of abdominal fat, absolute organ weights were as a rule significantly greater in B and IB than in I and C mice. IGF-II overproduction as a tendency increased the weights of kidneys, adrenal glands, pancreas and uterus both in the absence and presence of the bGH transgene. Analysis of relative organ weights demonstrated significant (p < 0.05) effects of elevated IGF- II on the relative growth of kidneys (males and females) and adrenal glands (females), confirming our previous report on organ growth of PEPCK-IGF-II transgenic mice. In females, IGF-II and GH overproduction were additive in stimulating the growth of spleen and uterus, providing evidence for tissue-specific postnatal growth promoting effects by IGF-II in the presence of elevated IGF-I     

Gastrointestinal and tissue levels of nickel in deer mice<Emphasis Type="Italic">Peromyscus maniculatus</Emphasis> and woodrats<Emphasis Type="Italic">Neotoma fuscipes</Emphasis> from serpentine and nonserpentine areas

Serpentine geologic formations have soils high in nickel. Nickel exerts deleterious effects on several body systems, and often accumulates in organs of laboratory animals exposed to nickel. To establish if deer micePeromyscus maniculatus Wagner, 1845 and dusky-footed woodratsNeotoma fuscipes Baird, 1858 of serpentine areas ingest nickel, and to determine if nickel accumulates in body tissues, I measured nickel in several organs and tissues of animals from serpentine and nonserpentine sites in southern Oregon. Nickel was present in significantly greater concentrations in the contents of the stomachs and small intestines ofP. maniculatus andN. fuscipes from serpentine areas than in those of animals from nonserpentine areas. Nickel was not detected, or was present in only trace amounts, in the livers, kidneys, spleens, hearts, lungs, brains, skeletal muscles, and bones of both species from both serpentine and nonserpentine sites.P. maniculatus from serpentine areas had significantly greater concentrations of nickel in the seminal vesicles, testes, and uteri and ovaries than didP. maniculatus from nonserpentine areas.     

A COMMERCIAL MARKET FOR ORGANS? WHY NOT

Manga examines the issues surrounding controversial proposals to commercialize organ procurement as a means of reducing the shortage of organs for transplantation. He begins by attempting to define the term "commercialization." Then he discusses the ethical issues of a market approach to organ procurement: the exploitation of the poor, especially in the Third World; the potential negative effect on voluntary donation; the right to dispose of a body or its parts as private property; the question of justice in access to organs; the quality of purchased organs; and the overall social implications of a policy that allows or even encourages the buying and selling of a desperately-needed medical resource. Manga next considers alternative solutions to increasing the supply of organs, and recommends a strategy that could alleviate the organ shortage without resorting to commercialization.     

Effects of rearing temperature and level of food intake on organ size and tissue composition in piglets

Piglets are particularly susceptible to cold and nutritional stress because of their poor insulation and low body fat. The purpose of this study was to examine how ambient temperature and level of food intake affect development in piglets. Thirty-two piglets were reared individually from 14 to 56 days of age in either a cold (10 degrees C) or a warm (35 degrees C) environment. Two feeding regimens, restricted and ad libitum, were used to assess the effect of food intake on organ mass. The ad libitum fed pigs in both environments gained weight at the same rate. Paired t-tests of organ weights of ad libitum fed pigs revealed that the mass of the heart, liver, kidneys, stomach, and small intestine, and total nitrogen and the length of the small intestine were greater in cold-reared than in warm-reared littermates of the same body weight. The skin mass and total fat mass, the lengths of the body, extremities, and individual long bones, and the total surface area were greater in warm-reared than in cold-reared individuals. A regression analysis showed body weight was the most important determinant of size for all tissues measured except fat mass, which was affected slightly more by rearing temperature. Of the organs and tissue components that differed in size in warm- and cold-reared pigs, heart, kidney, stomach, skin, nitrogen, and fat mass, and small intestine length and surface area were generally affected more by rearing temperature than by level of food intake. Liver and small intestine mass and femur length were affected more by level of food intake.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dental "silver" tooth fillings: a source of mercury exposure revealed by whole-body image scan and tissue analysis

Mercury (Hg) vapor is released from dental "silver" tooth fillings into human mouth air after chewing, but its possible uptake routes and distribution among body tissues are unknown. This investigation demonstrates that when radioactive 203Hg is mixed with dental Hg/silver fillings (amalgam) and placed in teeth of adult sheep, the isotope will appear in various organs and tissues within 29 days. Evidence of Hg uptake, as determined by whole-body scanning and measurement of isotope in specific tissues, revealed three uptake sites: lung, gastrointestinal, and jaw tissue absorption. Once absorbed, high concentrations of dental amalgam Hg rapidly localize in kidneys and liver. Results are discussed in view of potential health consequences from long-term exposure to Hg from this dental material.     

Comparative studies of body mass,body measurements and organ weights of wild-derived and laboratory golden hamsters (Mesocricetus auratus)

All laboratory golden hamsters originate from a sibling pairing back in 1930. To investigate possible differences between domesticated and wild conspecifics, descendants of both strains were maintained under standardized laboratory conditions individually and in unisexual groups. Body mass and food consumption were monitored from birth to 22 weeks of age. The animals were subsequently sacrificed, and body measurements and body composition were analysed. In addition, the absolute and relative masses of different organs were measured. Laboratory hamsters gained more body mass through higher food consumption. However, they did not get fatter, since relative fat values were the same for both strains. Body measurements revealed only minor differences (in body and ear lengths). As deducible from the body mass, the organs (spleen, kidneys, adrenal glands, testes, epididymis and ovaries) were seen to be heavier in laboratory hamsters. Furthermore, with the exception of the kidneys, the same went for the relative values. There were distinct sexual specific differences in both strains only for body fat ( male symbol male symbol upward arrow ) and adrenal glands ( male symbol male symbol upward arrow ). In females, group housing induced an elevated level of aggression. In general, these housing conditions led to social stress symptoms, such as heavier adrenal glands. Additionally, spleen, kidneys, ovaries, body length and mass, body water and body fat were increased in group-housed hamsters. In conclusion, no major differences between laboratory and wild-derived hamsters were observed.     

Inhibition of DNA adduct formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and 2-amino-3-methylimidazo[4,5-f]quinoline by dietary indole-3-carbinol in female rats.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) are two important heterocyclic amines formed in proteinaceous foods during the cooking process. Both PhIP and IQ are carcinogenic in several strains of rats. PhIP induces mammary tumors in female F344 rats, while IQ induces principally mammary and liver tumors in female Sprague-Dawley rats. Both PhIP and IQ are activated enzymatically, first by N-hydroxylation, catalyzed by CYP1A1 and CYP1A2, and subsequently by esterification (O-acetylation or sulfation), to yield DNA adducts. Such DNA adduct formation, and persistence of adducts, is related to initiation of carcinogenesis, while inhibition of this process leads to prevention of carcinogenesis. Indole-3-carbinol (I3C), a constituent of cruciferous vegetables, has chemopreventive properties in various systems; it probably acts by induction of detoxification enzymes. We have examined the effect of dietary I3C on DNA adduct formation by PhIP in female F344 rats and on that by IQ in female Sprague-Dawley rats. In experiment 1, F344 rats were maintained on AIN-76A diet containing 0.1% (w/w) I3C and then given p.o. doses (10 or 50 mg/kg) of PhIP. These doses are known to induce CYP1A1 and CYP1A2. Groups of animals (4/time point) were euthanized 1, 2, 6, and 16 days later, and their blood (for isolation of white blood cells), mammary glands, liver, stomach, small intestine, cecum, colon, heart, lungs, kidneys, and spleen were removed for DNA isolation and quantitation of PhIP-DNA adducts by 32P-postlabeling. PhIP-DNA adduct formation was inhibited (40-100%) by I3C in virtually all organs, including the mammary gland (the target organ), at both doses of PhIP, and at almost all time points. In a second experiment, Sprague-Dawley rats were fed either control AIN-76A diet or this diet containing 0.02% I3C or 0.1% I3C for a total of 42 days. IQ was added to the diets (0.01%, w/w) from day 15 to day 42, after which all rats received diet free of IQ and I3C. Groups of animals (4/time point) were killed on days 43 and 57. In addition to the organs removed in experiment 1, the pancreas, uterus, and ovaries were also removed, and IQ-DNA adducts were quantitated by 32P-postlabeling. Both dietary concentrations of I3C inhibited IQ-DNA adduct formation in most organs (except in lungs, kidneys, and pancreas) on both days 43 and 57; in liver, stomach, mammary gland, and spleen, inhibition was evident only on day 43. Inhibitions ranged from 22.6 to 86.6% with the 0.02% I3C diet and from 32.2 to 89.6% with the 0.1% I3C diet. I3C diets did not affect rate of adduct removal in either experiment. It is concluded that dietary I3C inhibits PhIP- and IQ-DNA adduct formation in both target and nontarget organs of female rats, even with high doses of PhIP when CYP1A1 and CYP1A2, the enzymes responsible for the initial activation (N-hydroxylation) of PhIP, are expected to be induced.     

Gesamtstoffwechsel und summierte Gewebsatmung in Beziehung zur Körpergröße

Recording weight-specific total body metabolism of the mouse at two ambient temperatures (22.5°, 35° C) and plotting the resulting data on a double logarithmic grid revealed a cyclic allometry with a positive constant between 1.3 and 5 g body weight (cycle I) and a negative constant between 5 (or 7) and 23 g (cycle II). Similar cycles concerning the weight-allometry of the mass of several organs (brain, heart, liver, skin) and the tissue respiration of brain, liver, intestine and kidneys are statistically significant. If the summated tissue respiration is determined over the entire body size range — by summing up tissue respiration for several individual body weights and calculating the regression lines — two cycles are, again, observable; their slopes cannot be distinguished statistically from those of the cycles of total body O₂-uptake at 35° C. Its intensity, however, is considerably lower than that of the directly measured total body metabolism. If certain corrections are applied (inclusion of skin respiration and extrapolation of respiration in vitro to t₀ the intensity of summated tissue respiration as well as its slope coincide well with the BMR obtained from literature.     

Tissue distribution and clearance of soluble murine TNF receptors in mice

In this study, clearance of sTNFR was investigated. The data show that bilateral nephrectomy results in an increase of the levels of both sTNFR after which a new steady state situation develops, suggesting that other organs, apart from the kidneys, are involved in clearing of sTNFR. Bilateral nephrectomy also leads to an increase in circulating TNF. This TNF was detected by ELISA and appeared to be not biologically active. To investigate whether the endotoxin induced increase in sTNFR is dependent of renal function, endotoxin was injected in nephrectomized mice. The data show that nephrectomy followed by endotoxin injection resulted in a further increase of the levels of both sTNFR. However, the endotoxin induced increase in nephrectomized mice was similar to the situation in normal mice after LPS indicating that the endtoxin induced increase is kidney independent in these mice. To investigate the relative participation of various organs in sTNFR clearance, ¹²⁵I labelled sTNFR-P75 was injected. The data reveal that the majority of the sTNFR is removed from the circulation by the kidneys although indications for involvement of the liver and the lungs were also obtained. Calculation of the parametric clearance revealed that nephrectomy resulted in a 50% reduction of sTNFR-P75 clearance. Furthermore, the data presented strongly suggest that sTNFR release seems to be a continuous process, which is in balance with clearance of the sTNFR by the kidney, although other organs such as the liver and the lungs are involved.     

Possible ctenophoran affinities of the Precambrian "sea-pen" Rangea

The Namibian Kuibis Quartzite fossils of Rangea are preserved three-dimensionally owing to incomplete collapse of the soft tissues under the load of instantaneously deposited sand. The process of fossilization did not reproduce the original external morphology of the organism but rather the inner surface of collapsed organs, presumably a system of sacs connected by a medial canal. The body of Rangea had tetraradial symmetry, a body plan shared also by the White Sea Russian fossil Bomakellia and possibly some other Precambrian frond-like fossils. They all had a complex internal anatomy, smooth surface of the body, and radial membranes, making their alleged colonial nature unlikely. Despite a different style of preservation, the Middle Cambrian Burgess Shale frond-like Thaumaptilon shows several anatomical similarities to Rangea. The body plan of the Burgess Shale ctenophore Fasciculus, with its numerous, pinnately arranged comb organs, is in many respects transitional between Thaumaptilon and the Early Cambrian ctenophore Maotianoascus from the Chengjiang fauna of South China. It is proposed that the irregularly distributed dark spots on the fusiform units of the petaloid of Thaumaptilon represent a kind of macrocilia and that the units are homologous with the ctenophoran comb organs. These superficial structures were underlain by the complex serial organs, well represented in the fossils of Rangea. The Precambrian "sea-pens" were thus probably sedentary ancestors of the ctenophores.     

Transition between moult and migration in a long-distance migratory passerine: organ flexibility in the African wintering area

Phenotypic flexibility of organs in migratory birds has been documented for a variety of species of different genera during the migratory period. However, very little is known about phenotypic mass changes of organs with respect to other events within the annual cycle. This seems particularly interesting when birds face different physiological challenges in quick succession. We investigated mass changes of 13 organs from garden warblers (Sylvia borin) during the transition from moult to migration. These long-distance migratory birds perform a complete moult within their wintering area just shortly before the onset of spring migration. Birds were sampled in three successive stages according to their moult status: group I consisted of birds with growing primary or secondary wing feathers, group II consisted of birds with completed wing moult but with still moulting body feathers, and group III consisted of birds that had completed wing moult and body moult. Size-corrected flight muscle, kidney mass, and pancreas mass differed significantly among the three groups. Flight muscle was heaviest in birds that were about to leave their wintering area (group III) compared with birds still in body moult (group II). Kidney and pancreas showed a pattern similar to each other, with the heaviest mass occurring in birds with moulting wing feathers (group I) and significantly reduced mass in birds that had completed wing moult (group II) or both wing and body moult (group III). Mass reductions of kidney and pancreas during the transition from moult to migration are considered to be related to the demands of moult, while increased flight muscle may be due to moult, migration, or both. Phenotypic mass changes of organs in birds occur during their migration, but they also occur during the transition between other phases of the annual cycle such as moult and migration and are not restricted to the flight muscle.     

Availability of water affects organ growth in prenatal and neonatal snapping turtles (Chelydra serpentina)

We manipulated the amount of water that was available to prenatal and neonatal snapping turtles (Chelydra serpentina) in order to assess the impact of water on growth by different organs in these animals. Three treatments were used: (1) turtles that completed their incubation on a wet substrate, (2) turtles that completed their incubation on a dry substrate, and (3) turtles that spent a few days in water after completing incubation on a dry substrate. Turtles hatching on a dry substrate (treatment 2) were smaller than animals in the other two treatments (which did not differ in size), so data for mass of different organs were adjusted by ANCOVA to remove effects of body size. Scaled masses of liver, stomach, lungs, kidneys, and small intestine did not differ between turtles emerging in wet environments and those hatching in dry environments, but hearts of turtles hatching in dry settings were substantially larger than those of animals hatching in wet ones. Thus, the mass of most organs in turtles developing in wet and dry environments scaled to body size, whereas the heart was hypertrophied in embryos developing in dry environments. Turtles that spent a few days in water after hatching from eggs in dry environments grew rapidly in size, and the increase in body size was accompanied by disproportionately rapid growth in the liver, stomach, lungs, kidneys, and small intestine. The heart did not increase in size during this period, despite the substantial increase in body mass over that at hatching. The enlarged heart of turtles hatching on dry substrates may have been caused by a circulatory hypovolemia late in incubation; the rapid growth of organs other than the heart when these animals were placed in water may reflect a release from constraints on growth once circulatory volume was restored. Accepted: 2 November 1999