“Relative” adRenal insufficiency in cRitical illness

ObjectiveTo present a recommended approach to the problem of “relative” adrenal insufficiency (RAI) in the intensive care unit (ICU).MethodsWe examine historical data that support the traditional concepts of adrenal insufficiency and the idea that the increase in cortisol secretion during stress is needed to survive the stress. The controversial use of treatment with glucocorticoids (GCs) in patients with sepsis and septic shock in the ICU (and thus survival benefit) is also briefly discussed.ResultsDuring the past decade, the concept of RAI as the failure of cortisol secretion to increase in response to stress to sustain the patient through that stress has gained strength. In some studies, it has been suggested that as many as 75% of patients in an ICU setting have RAI. Experimental support for the concept is not possible because there is no clinically useful laboratory measure of GC action. Therefore, diagnosis is generally based on interpretation of the cosyntropin stimulation test.ConclusionThe best clinical judgment should always guide interpretation of any test results, and sharp categorization of patients on the basis of a single cutoff criterion should be avoided. Overall, the concept of RAI has no clinical utility. In these cases, administration of GCs adds cost without benefit and with increased risk. (Endocr Pract. 2009;15:632-640)     

An explication of ‘wind illness’ in Northern Thailand

Wind illness is a very common complaint among the Northern Thai, yet is rarely recognized by Thai physicians trained in biomedicine. Persons most susceptible to wind illness are adult women who have ever borne a child. Consequently, data were obtained from 415 everparous women, 43% of whom reported ever having had wind illness and 57%, never having had it. In addition, 20 individuals who had ever had the syndrome were followed for case study, and 13 indigenous healers who traditionally treat clients suffering wind illness were interviewed. Their perceptions of the etiology, symptomatology and treatment of wind illness are reported in Part I. Part II is an attempt to define wind illness in terms of biomedicine and as a consequence of fertility. Part III synthesizes the emic and etic accounts with explanations for the perdurance of wind illness despite the advances of biomedicine and the recent fertility decline in Northern Thailand.     

Birthweight - is it linked to minor illness in adulthood?

OBJECTIVE: The Barker's hypothesis states that poor nutrition in vitro is linked to low birthweight and major illness, in particular cardiovascular disease, in later life. Reported here is an investigation to establish links with birthweight and minor illness. METHODS: 78 participants whose birthweight ranged from 1.93 kg to 4.88 kg with a mean to 3.31 kg completed a symptom checklist. RESULTS: Analysis of variance indicates that those with a higher birthweight experience less minor illness. Regression analysis indicates that birthweight is significantly predictive of levels of some minor illnesses. CONCLUSION: This investigation adds a new dimension to Barker's hypothesis and shows that early environment can also affect levels of minor illness. It is suggested that susceptibility to minor illness may be explained by coactions between structure, function and environment prior to birth.     

Localization of β2-microglobulin in the term villous syncytiotrophoblast

The non-covalent association of beta 2-microglobulin with MHC class I molecules and MHC class I-type molecules such as FcRn or the hemochromatosis protein (HFE) is of major importance for their function, i.e., antigen presentation, IgG transport, and regulation of iron uptake, respectively. In the human hemochorial placenta, the syncytiotrophoblast forms a continuous epithelial layer covering the villous trees, where it directly contacts maternal blood and, among many other functions, mediates uptake of maternal IgG and iron. The villous syncytiotrophoblast lacks MHC class I molecules but expresses FcRn and HFE. Since data on beta 2-microglobulin synthesis and localization in the term villous syncytiotrophoblast were contradictory, we investigated the subcellular localization of beta 2-microglobulin by immunoelectron microscopy. Synthesis in the trophoblast is demonstrated by colocalization of beta 2-microglobulin with protein disulfide isomerase, a marker protein of the endoplasmic reticulum. The presence of beta 2-microglobulin at the apical plasma membrane corresponds to the recently observed association of beta 2-microglobulin with HFE and FcRn. Localization of beta 2-microglobulin in late endosomes/lysosomes, labeled with antibodies to lysosome membrane antigen LAMP 2, suggests also a degradative route of beta 2-microglobulin internalized by fluid-phase from the maternal blood.     

‘Hemiepiphyte’: a confusing term and its history

Background and Scope

Over more than 120 years of scientific study since Schimper''s seminal work, the recognized categories of structurally dependent plants have changed several times. Currently, ignoring parasitic mistletoes, it is usual to distinguish four functional groups: (1) true epiphytes; (2) primary hemiepiphytes; (3) secondary hemiepiphytes; and (4) climbing plants, i.e. lianas and vines. In this Viewpoint, it is argued that the term secondary hemiepiphytes (SHs) is misleading, that its definition is hard to impossible to apply in the field and, possibly causally related to this conceptual problem, that the use of this category in field studies is inconsistent, which now hampers interpretation and generalization.

Conclusions

Categories will frequently fail to capture gradual biological variation, but terms and concepts should be as unambiguous as possible to facilitate productive communication. A detailed analysis of the conceptual problems associated with the term SH and its application in scientific studies clearly shows that this goal is not fulfilled in this case. Consequently, the use of SH should be abandoned. An alternative scheme to categorize structurally dependent flora is suggested.     

Is routine induction of labour at term ever justified?

Balancing the risks of prolonged gestation against those of induced labour is difficult. Risks to the fetus increase slightly after 42 weeks'' gestation but women having labour induced are more likely to have instrumental deliveries or babies with low Apgar scores. Since many women are now expressing a preference for minimal interference in childbirth the most acceptable management of post-term pregnancy seems to be increased fetal surveillance. Each case needs to be considered individually and it is important that the woman is involved in the decision to induce.     

Arteriovenous carboxyhemoglobin difference in critical illness: fiction or fact?

It is still unclear whether the paradoxical arteriovenous carboxyhemoglobin (COHb) difference found in critical illness is due to increased COHb production by the lung, or whether this gradient is caused by technical artifacts using spectrophotometry. In healthy and matched endotoxemic sheep, blood gases were analyzed with a standard ABL 625 and the updated version, an ABL 725. The latter one was accurately calibrated for COHb wavelengths (SAT 100) to eliminate the FCOHb dependency on oxygen tension. All endotoxemic sheep exhibited a hypotensive-hyperdynamic circulation and a pulmonary hypertension. Interestingly, arteriovenous COHb difference occurred in both healthy and endotoxemic sheep (P<0.001 each). Arterial and central venous COHb concentrations determined with the ABL 625 were significantly lower than those measured with the ABL 725 (P<0.001 each). We conclude that (a) arteriovenous COHb difference per se does not reflect critical illness and (b) measurements with an ABL 625 underestimate COHb concentrations.     

Long‐term wildlife road‐kill counts in New Zealand

Abstract

We compare the number of medium‐sized animals (between rat and dog‐size) killed on repeated counts along the same 1660 km of North Island highways in 1984, 1994 and 2005 with other counts going back to 1949. Elevenmammal and 14 bird species were recorded, but Australian possums (Trichosurus vulpecula), hedgehogs (Erinaceus europaeus) and rabbits (Oryctolagus cuniculus) predominated, and pukekos (Porphyrio porphyrio), mynas (Acridotheres tristis), and Australian magpies (Gymnorhina tibicen) were the most common birds. Counts of possums, hedgehogs and rabbits ranged between 0.7 and 89 corpses/100 km, and changed dramatically over six decades. The possum count rose 80% between 1984 and 1994, but declined 60% by 2005. A possible irruption of hedgehogs is reported in 1988–89, followed by an 82% decline in their numbers between 1994 and 2005. Although rabbit hemorrhagic disease was introduced to New Zealand in 1997, rabbit road‐kill increased 59% between 1994 and 2005. The relationship between road‐kill and traffic volume indicates that roads carrying more than 3000 vehicles per day act as barriers to larger mammals, while vehicles on less busy roads are more dangerous for crossing animals. We suggest that regular counts taken at annual intervals over the same roads is a useful method for gathering information about the changing distribution and relative abundance of certain animals on a provincial or national scale and over long periods of time. Regular counts at seasonal, monthly or weekly intervals are also a rich source of information.     

Reconsideration of the term ‘vitrification’ as used in micropropagation

The term vitrification is currently used to describe two types of processes related to tissue-cultured plant material. The first is used to describe organs and tissues having an abnormal morphological appearance and physiological function. The second is used to describe the transition from liquid to solid state, i.e. the formation of ice during low temperature storage of in vitro cultured cells, tissues and organs. Use of the same term to define two greatly different processes in the same research area can only lead to confusion, especially for key words. Thus it is appropriate to reconsider the usage of vitrification in the first sense mentioned above. It is recommended that the term vitrification should no longer be used to indicate plant material with an abnormal morphological appearance and physiological function, and should be substituted by the term hyperhydricity.This paper was written as a follow up of the discussions held during the workshop on Vitrification at the IAPTC-Congress in Amsterdam (1990). Different eminent research workers in the field of vitrification were invited to formulate their preference for a new terminology, and they came to a consensus.     

Anticipation or ascertainment bias in schizophrenia? Penrose's familial mental illness sample.

Several studies have observed anticipation (earlier age at onset [AAO] in successive generations) in familial schizophrenia. However, whether true anticipation or ascertainment bias is the principal originating mechanism remains unclear. In 1944 L. S. Penrose collected AAO data on a large, representative sample of familial mental illness, using a broad ascertainment strategy. These data allowed examination of anticipation and ascertainment biases in five two-generation samples of affected relative pairs. The median intergenerational difference (MID) in AAO was used to assess anticipation. Results showed significant anticipation in parent-offspring pairs with schizophrenia (n = 137 pairs; MID 15 years; P = .0001) and in a positive control sample with Huntington disease (n = 11; P = .01). Broadening the diagnosis of the schizophrenia sample suggested anticipation of severity of illness. However, other analyses provided evidence for ascertainment bias, especially in later-AAO parents, in parent-offspring pairs. Aunt/uncle-niece/nephew schizophrenia pairs showed anticipation (n = 111; P = .0001), but the MID was 8 years and aunts/uncles had earlier median AAO than parents. Anticipation effects were greatest in pairs with late-AAO parents but remained significant in a subgroup of schizophrenia pairs with early parental AAO (n = 31; P = .03). A small control sample of other diseases had MID of 5 years but no significant anticipation (n = 9; P = .38). These results suggest that, although ascertainment-bias effects were observed in parent-offspring pairs, true anticipation appears to be inherent in the transmission of familial schizophrenia. The findings support investigations of unstable mutations and other mechanisms that may contribute to true anticipation in schizophrenia.     

Long term effects of ART: What do animals tell us?

Early stages of mammalian embryonic development are now known to be very sensitive to their microenvironment, with long term effects on fetal, postnatal, and adult health, thus extending to these early stages the concept of Developmental Origin of Health and Disease (DoHaD). In this scientific context, and with 3% of births in developed countries, safety of Assisted Reproductive Techniques procedures becomes a matter of concern. Besides, embryo technologies in domestic mammals, using huge number of embryos, do not seem to evidence heavy impacts on adult phenotypes. This paper first discusses what can or cannot be concluded from farm animal data, then develops long term effects of ART procedures (ovarian stimulation, in vitro fertilization and embryo culture) evidenced in model species (mainly mouse model). Recent literature demonstrates both individual and cumulative effects of each ART procedure on fetal and postnatal phenotypes. In a second part, because they are sources for further perturbations, immediate effects of ART on early embryo phenotypes at the cellular and molecular levels are described in both farm animals and model species. Mechanistic hypotheses supporting these ART induced phenotypic alterations are subsequently considered. Finally, taking into account interspecies differences in the mechanisms likely to be involved, the relevance of results obtained in animal models for human ART are discussed.