Proton chemical shift imaging of bone marrow for monitoring therapy in leukemia

In three patients with different forms of leukemia, follow-up examinations before, during, and after chemotherapy and bone marrow transplantation were performed by proton chemical shift imaging (1H-CSI). The relative fat and water fractions were computed in representative regions of the marrow in the femur, pelvis, and lumbar spine. On serial examinations the fat fractions increased over time, in agreement with the responses to therapy proven by bone marrow biopsies from the iliac crest. These preliminary results suggest a role for magnetic resonance and CSI in the monitoring of therapy in leukemia and systemic neoplastic diseases.     

Thyroid functions of mouse cathepsins B,K, and L

Thyroid function depends on processing of the prohormone thyroglobulin by sequential proteolytic events. From in vitro analysis it is known that cysteine proteinases mediate proteolytic processing of thyroglobulin. Here, we have analyzed mice with deficiencies in cathepsins B, K, L, B and K, or K and L in order to investigate which of the cysteine proteinases is most important for proteolytic processing of thyroglobulin in vivo. Immunolabeling demonstrated a rearrangement of the endocytic system and a redistribution of extracellularly located enzymes in thyroids of cathepsin-deficient mice. Cathepsin L was upregulated in thyroids of cathepsin K(-/-) or B(-/-)/K(-/-) mice, suggesting a compensation of cathepsin L for cathepsin K deficiency. Impaired proteolysis resulted in the persistence of thyroglobulin in the thyroids of mice with deficiencies in cathepsin B or L. The typical multilayered appearance of extracellularly stored thyroglobulin was retained in cathepsin K(-/-) mice only. These results suggest that cathepsins B and L are involved in the solubilization of thyroglobulin from its covalently cross-linked storage form. Cathepsin K(-/-)/L(-/-) mice had significantly reduced levels of free thyroxine, indicating that utilization of luminal thyroglobulin for thyroxine liberation is mediated by a combinatory action of cathepsins K and L.     

Prevalence of Micronutrient Deficiency in Patients with Morbid Obesity Before Bariatric Surgery

Background

Postoperative micronutrient deficiency is a known side effect of bariatric surgery. In this study, we examined the prevalence of micronutrient deficiency in patients with morbid obesity (MO) preoperatively.

Methods

A total of 1732 patients with MO wishing to undergo bariatric surgery (age: 40 ± 12 years, mean BMI: 44 ± 9 kg/m², means ± SD, 77.3% female) were analyzed in this cross-sectional examination. Iron state, vitamin B12, folic acid, 25hydroxy(OH)-vitamin D, PTH, vitamin A, and vitamin E levels were determined. Subsequently, patients underwent nutritional counseling and were substituted accordingly.

Results

A total of 63.2% (n = 1094) of the patients had a deficit in folic acid (< 5.3 ng/ml), 97.5% (n = 1689) in 25OHvitamin D (< 75 nmol/l), and 30.2% (n = 523) had a PTH elevation (> 56.9 pg/ml). A total of 5.1% (n = 88) of the patients presented with a deficit in vitamin B12 (< 188 pg/ml) and 6.2% (n = 107) in vitamin A (< 1.05 μmol/l). A total of 9.6% (n = 166) exhibited iron deficiency (ferritin < 15 μg/l). None of the patients had a deficit in vitamin E. There were no gender differences except for ferritin deficiency (women 11.8% vs. men 1.5%, p < 0.001). Patients in the highest BMI tertile had significantly more often a deficit in vitamin D (p = 0.033) and folic acid (p < 0.001). Patients in the lowest age tertile had significantly more often a deficit in folic acid (p < 0.001).

Conclusions

Our data show a high prevalence of micronutrient deficiency in patients with morbid obesity preoperatively and emphasize the importance of exact preoperative evaluation and adequate substitution as well as postoperative surveillance.

     

LRP1 modulates APP trafficking along early compartments of the secretory pathway

The amyloid beta peptide (Aβ) is a central player in Alzheimer's disease (AD) pathology. Aβ liberation depends on APP cleavage by β- and γ-secretases. The low density lipoprotein receptor related protein 1 (LRP1) was shown to mediate APP processing at multiple steps. Newly synthesized LRP1 can interact with APP, implying an interaction between these two proteins early in the secretory pathway. We wanted to investigate whether LRP1 mediates APP trafficking along the secretory pathway, and, if so, whether it affects APP processing. Indeed, the early trafficking of APP within the secretory pathway is strongly influenced by its interaction with the C-terminal domain of LRP1. The LRP1-construct expressing an ER-retention motif, LRP-CT KKAA, had the capacity to retard APP traffic to early secretory compartments. In addition, we provide evidence that APP metabolism occurs in close conjunction with LRP1 trafficking, highlighting a new role of lipoprotein receptors in neurodegenerative diseases.     

Citalopram versus amitriptyline in elderly depressed patients with or without mild cognitive dysfunction: a danish multicentre trial in general practice

This double-blind, multicenter trial, carried out in general practice in Denmark, comprised 221 women and 70 men, aged 58 to 97 years, with major depression (with or without mild cognitive dysfunction) or dysthymia (DSM-III-R). Patients had a total score > or =13 on the 17-item Hamilton Depression Rating Scale (HDRS) and a score > or =20 on the Mini Mental State Examination scale. The efficacy and tolerability of citalopram (20-40 mg daily) and amitriptyline (50-100 mg daily) were compared over 12 weeks. The participating general practitioners were trained at corating sessions in the use of the HDRS and Melancholia Scale (MES) prior to and during the study. The inter-observer reliability was assessed to investigate if general practitioners were able to use scales that measure the severity of depression. The two treatments were considered equally effective; the 90% confidence interval for the difference between the treatment groups in change from baseline to end-point in HDRS total score (-0.84 to +1.23) was within the predefined interval (-4 to +4). Significantly more patients on citalopram (50%) than on amitriptyline (31%) reported no adverse events at all (P = .001). Moreover, patients on amitriptyline reported adverse events significantly earlier and more frequently than patients on citalopram. The inter-observer reliability was highly satisfactory, with intra-class correlation coefficients (ICC-U) of .83 for the HDRS and .82 for the MES; however, the ICC-U for the Clinical Global Impressions was .54, indicating a poorer consensus in the investigators clinical judgment. Training in the use of the HDRS and MES scales improved the inter-observer reliability.     

Preliminary evidence of a noncausal association between the X-chromosome inactivation pattern and thyroid autoimmunity: a twin study

An increased frequency of skewed X-chromosome inactivation (XCI) is found in clinically overt autoimmune thyroid disease (AITD) compared with controls. Whether skewed XCI is involved in the pathogenesis of autoantibodies to thyroid peroxidase (TPOAb) in euthyroid subjects is unknown. To examine the impact of XCI on the serum concentration of TPOAb, we studied whether within-cohort and within-twin-pair differences in XCI are associated with differences in serum concentrations of TPOAb. A total of 318 euthyroid female twin individuals distributed in 159 pairs were investigated. XCI was determined by PCR analysis of a polymorphic CAG repeat in the first exon of the androgen receptor gene. TPOAb concentrations were measured using a solid-phase time-resolved fluoroimmunometric assay. Overall (within cohort), there was a significant association between XCI and serum concentrations of TPOAb; regression coefficient (β)=1.45 (95% confidence interval, 0.52–2.38), P=0.003. The association remained significant in the within-pair analysis; β=1.74 (0.79–2.69), P<0.001. The relationship was nonsignificant within the 82 monozygotic pairs (β=0.57 (−0.78–1.92), P=0.405), whereas the association was significant in the 77 dizygotic pairs (β=2.17 (0.81–3.53), P=0.002). This preliminary finding of a significant association between TPOAb concentrations and XCI within cohort and within dizygotic but not within monozygotic twin pairs may indicate that XCI per se does not have a major role in the pathogenesis of TPOAb. More likely, XCI and TPOAb are influenced by shared genetic determinants.     

Effects of Copper, Cadmium, and Zinc on the Hatching Success of Brine Shrimp (Artemia franciscana)

Previous studies indicate that the hatching success of brine shrimp (Artemia franciscana) cysts is surprisingly sensitive to ambient metal concentrations. These studies estimated median effective concentrations (EC₅₀s) of 7, 5, and 28 μg l⁻¹ for Cd, Cu, and Zn, suggesting that the hatching end point for A. franciscana is the most sensitive tested to date for Cd and Zn in saline environments and comparable in sensitivity with the most sensitive tested to date for Cu. Furthermore, these data suggest that brine shrimp are at significant risk from Cu and Zn in Great Salt Lake (GSL), UT, where ambient concentrations as high as 10 and 14 μg l⁻¹, respectively, have been measured. Given that brine shrimp appear to be successfully reproducing in GSL, we hypothesized that these toxicity values were either biased low as a result of an artifact of the test method used or that site-specific water-quality conditions in the lake had decreased metal bioavailability such that brine shrimp could successfully reproduce. To test these hypotheses, we initiated a step-wise series of experiments. First we investigated the effects of pretreatment of brine shrimp cysts with antibiotics on brine shrimp sensitivity to metals because previous investigators as part of their test methods have used antibiotics. Next we considered the effect of ionic composition of the artificial test media on sensitivity. Finally, we evaluated the effects of the site-specific water quality of the GSL on metal bioavailability and toxicity. Results indicate that pretreatment of cysts with antibiotics had no effect on sensitivity. However, we were unable to repeat the previous values for Cd and Zn, obtaining EC₅₀s of 11,859 and 289 μg l⁻¹ for Cd and Zn, respectively. For Cu, however, we estimated an EC₅₀ of 12 μg l⁻¹, so we conducted further testing on the artificial media, adjusting the media composition to better reflect the Ca²⁺ and HCO ₃ ⁻ concentration of normal seawater. This increased the EC₅₀ to 28 μg l⁻¹. Finally we evaluated the toxicity of Cu in GSL water and obtained an EC₅₀ of 68 μg l⁻¹, suggesting that the increased dissolved organic carbon in GSL has a significant protective effect. Overall, the results of this study suggest that brine shrimp hatching success is not particularly sensitive to Cd and Zn, but it is sensitive to Cu. However, site-specific water-quality conditions ensure that brine shrimp cyst hatching success is not significantly affected by any of these metals at the normal background concentrations that occur in GSL (<15 μg l⁻¹).