Über den Nahrungsbedarf der Ratte während der Schwangerschaft,während und nach der Stillzeit

Ohne ZusammenfassungMit 4 Abbildungen im Text.     

Measurement of T1, T2, and magnetization transfer properties during embryonic development at 7 Tesla using the chicken model

Purpose

To evaluate whether techniques of high field magnetic resonance imaging may be used to characterize embryonic tissue during proliferation and differentiation.

Materials and Methods

Thirteen chicken embryos with incubation times between 5 days and 16 days have been measured in a small animal magnetic resonance imager (ClinScan, Bruker) at 7 Tesla using the built‐in resonator. T1, T2‐, and magnetization transfer imaging was performed using fast spin‐echo with inversion recovery, half acquisition single shot turbo spin‐echo, and spoiled gradient‐echo sequences with and without off‐resonance pulse, respectively. T1, T2, and magnetization transfer ratio (MTR) maps were calculated on a pixel‐by‐pixel basis.

Results

T1‐, T2‐, and MTR maps showed good image quality allowing for delineation of embryonic organs. During embryonic development, a decrease of T1 and T2 relaxation times was found, whereas, embryonic tissue typically showed an increase of magnetization transfer, for example, liver properties at day 5: T1 = 2431 ± 163 ms, T2 = 122 ± 12 ms, MTR = 9.2 ± 4.2%; liver properties at day 16: T1 = 1763 ± 89 ms, T2 = 71 ± 4 ms, MTR = 16.9 ± 2.2%.

Conclusion

Embryonic tissues show changing relaxation and magnetization transfer properties during development, therefore, high field MRI seems suitable for characterization of tissue replacement derived from embryonic stem cells. J. Magn. Reson. Imaging 2008;28:1510–1514. © 2008 Wiley‐Liss, Inc.     

Chronic back pain: more than pain in the back. Findings of a regional survey among insurees of a workers pension insurance fund

BACKGROUND: Surveys with a main focus on back pain tend to isolate the complaint from possibly concomitant pains, other symptoms and disorders. Severe chronic back pain is assumed here to imply more than pain in the back. PARTICIPANTS AND METHODS: We report results from a two stage survey conducted in 1998 - 2000. The initial postal questionnaire addressed all 10,000 actively employed blue collar workers from a regional pension fund (Landesversicherungsanstalt Schleswig-Holstein) aged 40 - 54 and residing in or around Luebeck/Germany (68 % males). Subjects reporting severe and disabling back pain were invited to a socio-medical examination. The response and participation rates were 58 % and 65 % respectively. Non-response and non-participation seem to result in minor though opposite, effects. RESULTS: The prevalence of current back pain (back pain of any severity within the past 7 days) is high (68 %; including 16 % with severe, disabling back pain) despite the preponderance of males and a probable healthy worker effect. 82 % of subjects participating in the second round reported recurrent or persisting back pain on the day of examination, in the majority with a chronic fluctuating and overall deteriorating course pattern. 18 % reported no current back pain and hence gave prospective (and additionally retrospective) evidence of an episodic-intermittent course of the disorder. The former group showed significantly more pains, bodily complaints, dysfunctional cognitions, emotional distress and concomitant disorders. 35 % of them indicated back pain as their dominant health problem; 49 % identified back pain and another disorder as dominant, and 16 % reported other prominent health problems. More than 70 % of "other" disorders originated from the musculoskeletal system often involving the extremities. SUMMARY AND CONCLUSION: Back pain is very common among blue collar workers. Severe disabling back pain is usually associated with numerous other pains, bodily complaints, disorders, and indicators of psychological distress ("amplified back pain"). However, even amplified back pain is not always the sole or dominant health problem. Assessing the degree of "amplification" seems helpful in splitting a previously homogeneous group of severely affected back pain sufferers-with possible prognostic and therapeutic consequences.     

Biosynthesis of factor V in isolated guinea pig megakaryocytes.

Although platelets contain Factor V, localized primarily in the alpha-granules, the origin of this coagulation cofactor in these cells is not known. We therefore explored whether isolated megakaryocytes could biosynthesize Factor V. Guinea pig plasma Factor V coagulant activity was demonstrated to be neutralized by human monoclonal and rabbit polyclonal antibodies directed monospecifically against human Factor V. These antibodies had been used earlier to purify human Factor V. These antibodies had been used earlier to purify human Factor V and to quantify Factor V antigen concentration, respectively (1983. Chiu, H. C., E. Whitaker, and R. W. Colman. J. Clin. Invest. 72:493-503). As determined by a competitive enzyme-linked immunosorbent assay with guinea pig plasma as a standard, Factor V solubilized from guinea pig megakaryocytes was present at 0.098 +/- 0.018 micrograms/10(5) cells. Each megakaryocyte contained about 500 times as much Factor V as is in a platelet (0.234 +/- 0.180 micrograms/10(8) platelets). The content of Factor V antigen in guinea pig plasma was greater (27.0 +/- 3.0 micrograms/ml) than that of Factor V antigen in human plasma (11.1 +/- 0.4 micrograms/ml). In contrast, human platelets contain ninefold more Factor V antigen (2.01 +/- 1.09 micrograms/10(8) platelets) than do guinea pig were 2.85 +/- 0.30 U/ml plasma, 0.022 +/- 0.012 U/10(8) platelets, and 0.032 +/- 0.03 U/10(5) megakaryocytes, compared with human values of 0.98 +/- 0.02 U/ml plasma and 0.124 +/- 0.064 U/10(8) platelets. Isolated megakaryocytes were found to contain Factor V by cytoimmunofluorescence. The megakaryocytes were incubated with [35S]methionine, and radiolabeled intracellular proteins purified were on a human anti-Factor V immunoaffinity column. The purified protein exhibited Factor V coagulant activity and neutralized the inhibitory activity of a rabbit antihuman Factor V antibody, which suggests that megakaryocyte Factor V is functionally and antigenically intact. These results indicate that Factor V is synthesized by guinea pig megakaryocytes. Nonetheless, megakaryocyte Factor V was more slowly activated by thrombin and in the absence of calcium was more stable after activation than was plasma Factor Va. Electrophoresis in sodium dodecyl sulfate and autoradiography of the purified molecule showed a major band of Mr 380,000 and a minor band of Mr 350,000, as compared with guinea pig and human plasma Factor V, where the protein had an Mr of 350,000. Both forms of Factor V were substrates for thrombin. Possible explanations for the higher molecular weight and different thrombin sensitivity and stability observed are that a precursor of Factor V was isolated or that the megakaryocyte Factor V had not been fully processed before isolation.     

Polymorphisms in the gene encoding adiponectin receptor 1 are associated with insulin resistance and high liver fat

Aims/hypothesis The adipokine adiponectin has insulin-sensitising, anti-atherogenic and anti-inflammatory properties. Recently, the genes for mouse and human adiponectin receptor-1 (ADIPOR1) and -2 (ADIPOR2) have been cloned. The aim of this study was to investigate whether genetic variants of the genes encoding ADIPOR1 and ADIPOR2 play a role in human metabolism.Materials and methods We screened ADIPOR1 and ADIPOR2 for polymorphisms and determined their association with glucose metabolism, lipid metabolism, an atherogenic lipid profile and inflammatory markers in 502 non-diabetic subjects. A subgroup participated in a longitudinal study; these subjects received diet counselling and increased their physical activity.Results We identified six variants of ADIPOR1 and seven variants of ADIPOR2. A single-nucleotide polymorphism (SNP) in the putative promoter region 8503 bp upstream of the translational start codon (–8503 G/A) of ADIPOR1 (frequency of allele A=0.31) was in almost complete linkage disequilibrium with another SNP (–1927 T/C) in intron 1. Subjects carrying the –8503 A and –1927 C alleles had lower insulin sensitivity, as estimated from a 75 g OGTT (p=0.04) and determined during a euglycaemic clamp (n=295, p=0.04); they also had higher HbA₁c levels (p=0.02) and, although the difference was not statistically significant, higher liver fat (n=85, determined by proton magnetic resonance spectroscopy, p=0.056) (all p values are adjusted for age, sex and percentage of body fat). In the longitudinal study (n=45), the –8503 A and –1927 C alleles were associated with lower insulin sensitivity (p=0.03) and higher liver fat (p=0.02) at follow-up compared with the –8503 G and –1927 T alleles, independently of basal measurements, sex and baseline and follow-up percentage of body fat.Conclusions/interpretation The present findings suggest that the –8503 G/A SNP in the promoter or the –1927 T/C SNP in intron 1 of ADIPOR1 may affect insulin sensitivity and liver fat in humans.Electronic Supplementary Material Supplementary material is available for this article at .