Pre-adaptation, adaptation and de-adaptation to high altitude in humans: hormonal and biochemical changes at sea level

High altitude residence is known to modify body biochemistry and hormone status. However, the effects of such a sojourn on these status observed at sea level both immediately and later after return are not as well established as are the effects of an intermittent acclimation. The aim of this study was therefore to investigate these changes. To achieve our objectives, nine subjects received intermittent acclimation at low pressure in a barometric chamber (8?h daily for 5 days, day 1 at 4500 m, day 5 at 8500 m) before an expedition to the Himalayas. Hormonal and biochemical changes were studied using samples of venous blood taken at sea level before and after acclimation, after return from the expedition and 1 and 2 months after descent. Concentrations of thyroid hormones, adrenaline, noradrenaline (NA), hormones of hydromineral metabolism (aldosterone, renin, arginine vasopressin, atrial natriuretic peptide) as well as prolactin, cortisol, insulin and endothelin 1 were measured. Biochemical measurements made were plasma osmolality, and concentrations of glucose, total cholesterol, total proteins, pre-albumin, transferrin, complement 3C, apolipoproteins A₁ and B and serum iron. Acclimation induced no alteration in hormone (except for NA with increases of about 1.5, fold P<0.05) and biochemistry data. After the expedition, hormone responses were characterized by a higher total triidothyronine concentration (+18%, P<0.05) while other hormones did not vary. A linear relationship was found between thyroid-stimulating-hormone and body mass changes after the expedition (r=0.67, P<0.05). The observed increased concentrations of plasma proteins and total cholesterol (P<0.05) could be related to the restoration of lean body mass. At 1 and 2 months after return, no changes in hormones were observed but a significant decrease in transferrin concentration was noticed. The higher serum iron concentration reported after 1 month (P<0.05) could have been the result of a physiological haemolysis. It was concluded that both acclimation and the expedition in the Himalayas affected hormone status and body biochemistry status even though the observed changes were slight and rapidly reversed.     

A study on OX39, a murine anti-rat interleukin 2 receptor antibody

OX39, a murine IgG1 monoclonal antibody (MoAb) that recognizes the 55 kDa alpha chain of the rat interleukin 2 receptor (R-IL2), was studied in vitro for its ability to interfere with IL2 binding and IL2-induced proliferation on rat concanavalin A (ConA) blasts and in vivo in a model of rat heart allografts. In vitro studies indicated that OX39 MoAb interacts with a single class of sites on the alpha chain of the rat R-IL2 with a high affinity (K_D=0.8 nm) and competes with IL2 binding on this chain (K_I=0.53 nm). In contrast, OX39 MoAb was found to be 10–20 times less efficient in competing with IL2 binding to the high-affinity R-IL2 (K_I10 nm). It is proposed that the epitope recognized by OX39 on the alpha chain (low-affinity R-IL2) is modified on (or buried in) the high-affinity R-IL2 configuration. Accordingly, OX39 was found to be a weak inhibitor in vitro on IL2-induced proliferation and in vivo on allograft rejection. Allograft survival was unaffected by doses of OX39 of 20 and 50 g/rat for 9 days; only a borderline effect was noted when doses as high as 250 g/rat were used. A significant, but restricted, effect of OX39 could be further detected when combined with low doses of cyclosporine A (1.5 mg/kg), which were ineffective by themselves. Together, our data suggest that in order to be efficient in vivo, anti-R-IL2 MoAbs must bind with high affinity to epitopes involved in the high-affinity IL2 binding site.     

Retention and biomechanics of "retention complexes" 2. Retention complexes of Akers, Roach and Ney

The authors describe the different "retentive complexes" proposed by the Akers, Roach and Ney schools and analyse their biomechanical validity.     

Complex Ph1 translocation in chronic myeloid leukemia

This report describes a new case of chronic myeloid leukemia with an unusual Philadelphia chromosome translocation involving chromosomes No. 4,9, and 22; t(4,9,22) (q31;q34;q11).     

Chromosomes in tumors derived from mouse tumor x diploid cell hybrids obtained in vitro

Hybrids formed in vivo between Cl.1D tumor cells and host cells have been shown to carry a copy of each chromosome pair contributed by the host cell parent (1). However, in these hybrids, the tissue type of the host cell parents remained unknown. In the present study, hybrids between the malignant Cl.1D fibroblasts and either normal diploid fibroblasts (CF hybrids) or normal thymocytes (CT hybrids) were examined. These hybrids produced tumors when injected into host mice. Metaphases of growing hybrid cell tumors were analyzed. Neither CF nor CT malignant hybrids showed loss of any specific chromosome pair contributed by the normal cell parent. Since elimination of any chromosome pair contributed by the diploid fibroblast parent is not a prerequisite for CF hybrid tumoral growth, it seems unlikely that malignancy of hybrids results from nonexpression of normal alleles of those genes putatively implied in malignancy of Cl.1D cells.     

Amyloidosis in familial Mediterranean fever patients: correlation with MEFV genotype and SAA1 and MICA polymorphisms effects

Background

Hemihyperplasia (hemihypertrophy) is defined as asymmetric body overgrowth of one or more body parts. Hemihyperplasia can be isolated or be part of well-defined syndromes such as in the case of Beckwith-Wiedemann syndrome (BWS). Isolated hemihyperplasia is usually sporadic, but a number of familial occurrences have been described.

Case presentation

We describe a Tunisian family in which three maternal cousins and their maternal grandfather present with isolated hemihyperplasia.

Conclusions

The etiology of isolated hemihyperplasia is unknown although in BWS, genomic imprinting has been shown to play a role in the asymmetric overgrowth. Given the similarity between these two conditions, it is possible that both may share a common pathogenesis. We also discuss the possible genetic mechanisms leading to the production of hemihyperplasia in this family.     

Artificial Circulation of the Liver: Machine Perfusion as a Preservation Method in Liver Transplantation

Due to the sharp increase in liver transplant candidates and the subsequent shortage of suitable donor livers, an extension of the current donor criteria is necessary. Simple cold storage, the current standard in organ preservation has proven to be insufficient to preserve extended criteria donor livers. Therefore a renewed interest grew toward alternative methods for liver preservation, such as hypothermic machine perfusion and normothermic machine perfusion. These “new” preservation methods were primarily assessed in rat models, and only a few clinically relevant large animal models have been described so far. This review will elaborate on these alternative preservation methods. Anat Rec, 291:735–740, 2008. © 2008 Wiley‐Liss, Inc.