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- Decker, Ralph, 1968, et al.
(författare)
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Case report of a girl with secondary amenorrhea associated with aurantiasis cutis
- 2016
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Ingår i: Hormone Research in Paediatrics. - : S. Karger AG. - 1663-2818 .- 1663-2826.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: --- Aurantiasis cutis is a condition of yellowish or golden skin discoloration that can result from eating excessive amounts of foods containing carotene leading to hypercarotenemia(1), described causing secondary amenorrhea(2). Objective & hypothesis: --- Hypercarotenemia can cause secondary amenorrhea without overconsumption of excessive quantities of carotene. Results: --- Laboratory tests showed a ß-Carotene level more than the 2-fold above the upper reference level. Hyperbilirubinemia could be excluded. Hypogonadotropic hypogonadism was not present. There was no evidence for adrenal dysfunction. Liver function tests were normal. Material/ Methods: --- A 16-year-old girl presented to our endocrine outpatient clinic with a 2-year history of varying yellow discoloration of her skin and secondary amenorrhea. The findings of the general physical examination were normal, but there was a marked yellow discoloration of the palms, soles, and nasolabial folds. A dietary history revealed a low carotene diet, but also a low carbohydrate diet. BMI was 19.9 kg/m² (-0.2 SDS) without signs of anorexia. Discussion: --- In this girl we observed hypercarotenemia associated with secondary nonhypothalamic amenorrhea in absence of excess external intake of carotenes. This suggests an intrinsic reason due to a polymorphism(3) in ß-carotene 15,15'-monooxygenase (BCO)(4), an enzyme breaking down carotenes to vitamin A(5). Phenotype-genotype association studies are needed to confirm this hypothesis. Conclusion: --- Secondary non-hypothalamic amenorrhea can be associated with hypercarotenemia. References: --- 1. Tanikawa K, Seta K, Machii A, Itoh S 1961 [Aurantiasis cutis due to overeating of dried laver (nori): a case report]. Jpn J Med Sci Biol 50:414-419 2. Kemmann E, Pasquale SA, Skaf R 1983 Amenorrhea associated with carotenemia. JAMA 249:926-929 3. Leung WC, Hessel S, Meplan C, Flint J, Oberhauser V, Tourniaire F, Hesketh JE, von Lintig J, Lietz G 2009 Two common single nucleotide polymorphisms in the gene encoding beta-carotene 15,15'-monoxygenase alter beta-carotene metabolism in female volunteers. FASEB j 23:1041-1053 4. Frumar AM, Meldrum DR, Judd HL 1979 Hypercarotenemia in hypothalamic amenorrhea. Fertil Steril 32:261-264 5. Lindqvist A, Andersson S 2002 Biochemical properties of purified recombinant human beta-carotene 15,15'-monooxygenase. J Biol Chem 277:23942-23948
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| 5. |
- Gupta, Anindya, et al.
(författare)
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Convolutional neural networks for false positive reduction of automatically detected cilia in low magnification TEM images
- 2017
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Ingår i: Image Analysis. - Cham : Springer. - 9783319591254 ; , s. 407-418
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Konferensbidrag (refereegranskat)abstract
- Automated detection of cilia in low magnification transmission electron microscopy images is a central task in the quest to relieve the pathologists in the manual, time consuming and subjective diagnostic procedure. However, automation of the process, specifically in low magnification, is challenging due to the similar characteristics of non-cilia candidates. In this paper, a convolutional neural network classifier is proposed to further reduce the false positives detected by a previously presented template matching method. Adding the proposed convolutional neural network increases the area under Precision-Recall curve from 0.42 to 0.71, and significantly reduces the number of false positive objects.
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| 7. |
- Hauser, Janosch, et al.
(författare)
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A blood hematocrit test strip
- 2019
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Ingår i: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS). - : IEEE. - 9781728116105 ; , s. 426-428
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Konferensbidrag (refereegranskat)abstract
- This paper reports a self-propelled microfluidichematocrit (HCT) test that uses the correlation betweenblood hematocrit and wicking distance of blood in a specialpaper matrix. The enabling feature is a novel blood volumemetering method that allows sampling from the fingertipand reliably generates a highly precise blood volume of47.7 ± 1.9 μl (CV 4%) that is transferred into a porouspaper matrix. A dissolvable valve ensures a relaxed timewindow for blood sampling, making it highly user-friendlyand resilient to overfilling. The presented hematocrit teststrip poses a simple, cheap, equipment-free solution forpatient-centric hematocrit measurements.
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| 8. |
- Nylander, Anja, et al.
(författare)
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The ins and outs of SMIM1 and its relationship to the expression of Vel blood group antigen
- 2017
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Ingår i: Vox Sanguinis. - : Wiley. - 1423-0410 .- 0042-9007. ; 112:Suppl. 1, s. 48-49
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Konferensbidrag (refereegranskat)abstract
- Background: Vel blood group expression is dependent on Small Integral Membrane Protein 1 (SMIM1), a recently discovered erythroid protein. SMIM1 consists of 78 amino acids (aa) and shows only limited homology to other human proteins but is evolutionarily conserved, indicating its importance. The protein has a predicted transmembrane domain but the direction of insertion into the red blood cell (RBC) membrane is not yet clarified. The aa sequence contains reactive residues such as cysteines with the potential for disulphide bridge formation and a GXXXG motif known to induce dimerization in glycophorins. Many proteins form multimers to become functional. Thus, due to SMIM1's capability to dimerize and its association with mean corpuscular haemoglobin concentration (MCHC), we hypothesized that the above-mentioned motifs are of importance. Aims: The aim of this study was to investigate two features of SMIM1; GXXXG and the cysteine residues. Through mutagenesis studies, we investigated their role in Vel antigen expression and dimerization. Methods: Glycine in the GXXXG motif (aa 67-71) of the predicted transmembrane portion was substituted for leucine. Cysteine at positions 35, 43 and 77 was substituted for alanine. The SMIM1 constructs (incl. mock and wild-type) were transiently expressed in K562 cells. Vel surface expression was analysed using flow cytometry (FACS) with human polyclonal anti-Vel. The total protein content and dimerization was analysed by Western blot with a rabbit polyclonal antibody produced against the N-terminus (aa 1-15) of SMIM1. α-chymotrypsin treatment was performed as described [Storry et al. Nat Genet, 2013]. Results: Mutation of either or both of the glycines in the GXXXG motif caused significant reduction of Vel surface expression compared to SMIM1 wild-type, although the SMIM1 protein content remained unchanged as evaluated by Western blot. Substitution of p.Cys77Ala also significantly reduced Vel antigen expression, while no effect was observed by p.Cys35Ala or p.Cys43Ala. Again, the SMIM1 content appeared unaffected by the substitutions. The capacity to form dimers remained intact in all mutants. To verify the location of the N-terminus, α-chymotrypsin treatment of intact RBCs was performed. Absence of SMIM1-characteristic bands on Western blot of RBC membranes indicated that the N-terminal target for the rabbit antibody used was destroyed. Summary / Conclusions: Vel surface expression is severely affected by substitutions of glycine at positions 67 and 71, or of cysteine at position 77 in SMIM1. Disruption of a transmembrane localisation signal may explain the importance of glycine substitutions. The importance of Cys77 for Vel antigenicity could indicate an extracellular location of the C-terminus. This appears to be consistent with conclusions from the study by Arnaud et al. [FEBS Lett., 2015]. However, this is somewhat contradicted by our results from α-chymotrypsin treatment of intact RBCs. If the C-terminus is indeed extracellular and SMIM1 a type II protein, the N-terminus should be insensitive to such treatment. In summary, we conclude that the targeted GXXXG motif and Cys77 are important for the correct, extracellular exposure of the Vel antigen. It remains unclear if SMIM1 is a type I or II transmembrane protein. This question deserves further investigation to facilitate studies on functional aspects of this enigmatic protein.
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