Molecule diffusion in bacteria and consequences of osmotic stress

Dit proefschrift is een samenvatting van alle experimenten die ik de afgelopen vier jaar heb uitgevoerd. Het grootste deel van deze experimenten is gebaseerd op fluorescentie technieken, voornamelijk fluorescentie microscopie. In de hoofdstukken 2-6 (deel één van mijn proefschrift) richt ik mij op Echerichia coli, een veel gebruikt modelsysteem voor een bacteriële cel. Cellen zijn gevuld met allerlei verschillende macromoleculen die dusdanig dicht op elkaar gepakt zitten dat het vergelijkbaar is met de drukke mensenmassa in een winkelcentrum vlak voor de kerstdagen. Mijn doel was om uit te zoeken hoe snel moleculen in een cel kunnen bewegen onder deze omstandigheden. In hoofdstuk 2 geef ik een samenvatting van de recente literatuur over diffusie van (macro)-moleculen in bacteriën. Fluorescence Recovery After Photobleaching (FRAP) is een veelgebruikte fluorescentie-microscopie methode waarmee de diffusiesnelheid van moleculen bepaald kan worden. In hoofdstuk 3 vergelijk en beoordeel ik twee FRAP methodes voor het meten van de diffusiesnelheid van moleculen in bacteriën. In hoofdstuk 4 beschrijf ik de mobiliteit van grote, middelgrote en kleine moleculen in het celplasma van E. coli onder verschillende omstandigheden. Door de cellen bloot te stellen aan een osmotische verhoging van het milieu was het mogelijk de opeenpakking van moleculen in het celplasma te vergroten. Wanneer bijvoorbeeld de zoutconcentratie in het externe milieu toeneemt, zullen de cellen water verliezen (net als planten die te lang geen water hebben gekregen). Het gevolg hiervan is dat de moleculen in het cytoplasma dichter opeengepakt worden wat resulteert in een afname van hun diffusiesnelheid. Een belangrijke waarneming die ik beschrijf in hoofdstuk 4 is dat de opeenpakking van macromoleculen in het celplasma een veel groter effect heeft op de diffusie van grote moleculen (eiwitten) dan op kleine moleculen (voedingsstoffen)

Spontaneous cerebrospinal fluid leak at the clivus

We present a case report of a 60-year-old woman with a spontaneous cerebrospinal fluid leak at the clivus, obesity and no history of trauma. Follow-up imaging scans confirmed enlargement of the defect within the posterior clival framework to the size of 16 × 9 × 4 mm with a suspected meningocerebral hernia. The surgeons used the “two nostrils – four hands” endoscopic operating technique. The patient reported a history of cerebrospinal fluid leaks lasting for 3 years, with increasingly shorter leak-free periods and an increasing incidence of inflammatory complications. The patient recovered without complications, and she was discharged 14 days after the surgery. Good local outcome and improved patient condition were achieved postoperatively

Pitolisant protects mice chronically treated with corticosterone from some behavioral but not metabolic changes in corticosterone-induced depression model

Purpose: Histamine H3 receptor ligands may have antidepressant and anxiolytic effects. They can also compensate for metabolic disorders, which affect glucose or triglyceride levels. In previous studies, we have shown that pitolisant, a histamine H3 receptor antagonist/inverse agonist and σ1 receptor agonist, prevented the development of certain metabolic and depressive-like disorders in mice that have been treated chronically with olanzapine. Methods: As a continuation of our previous experiments, this study aimed to investigate the antidepressant- and anxiolytic-like activity of pitolisant in mice using the corticosterone-induced depression model. The forced swim and the elevated plus maze tests were used as behavioral endpoints. We also studied the effect pitolisant had on the level of acetoacetic acid in the urine as well as the glucose tolerance and body weight of the mice that had been administered corticosterone. Results: Pitolisant (10 mg/kg b.w.) did not prevent depressive-like behavior in mice during the chronic corticosterone administration but did counteract anxiety-like behavior, whilst fluoxetine (10 mg/kg) was shown to protect the mice from both of these behaviors. None of the treatments that were used in the study showed an effect on the locomotor activity of the mice. Pitolisant did not prevent an increase in acetoacetic acid levels in the urine, nor did it improve glucose tolerance in the tested mice. Conclusion: Although literature data indicates that there is significant potential for finding an antidepressant and anti-diabetic drug among the histamine H3 and σ1 receptor ligands, in our study, pitolisant was shown to only slightly compensate for corticosterone-induced abnormalities. However, further research will be required to study pitolisant's anxiolytic-like activity

Alterations in the amino acid profile in patients with papillary thyroid carcinoma with and without Hashimoto’s thyroiditis

PurposeAmino acids (AAs) play important physiological roles in living cells. Some amino acid changes in blood are specific for autoimmune disorders, and some are specific for thyroid cancer. The aims of this study were to profile AA metabolites in the serum of patients with papillary thyroid carcinoma (PTC0) without Hashimoto’s thyroiditis (HT) and patients with PTC with HT (PTC1) and predict whether AA metabolites are associated with thyroid disease, thyroid hormone and thyroid autoantibodies.MethodsA total of 95 serum samples were collected, including 28 healthy controls (HCs), 28 PTC0 patients and 39 PTC1 patients. Serum samples were analyzed by high-performance liquid chromatography-triple stage quadrupole-mass spectrometry (HPLC-TSQ-MS), and twenty-one amino acids (AAs) were detected.ResultsThe serum concentration of glutamic acid was significantly elevated in PTC1 patients compared with PTC0 patients. Lysine was the second amino acid that differentiated these two groups of PTC patients. In addition, the serum concentrations of glycine, alanine and tyrosine were significantly reduced in both PTC patient groups compared to the HC group. These AAs were also correlated with thyroid hormones and antibodies. Five amino acid markers, namely, glycine, tyrosine, glutamic acid, glutamine and arginine, separated/distinguished PTC0 patients from healthy subjects, and eight AA markers, the same AAs as above without arginine but with alanine, leucine, valine and histidine, separated/distinguished PTC1 patients from healthy subjects based on ROC analysis.ConclusionCompared with the HCs, changes in AAs in PTC0 and PTC1 patients showed similar patterns, suggesting the possibility of a common pathophysiological basis, which confirms preliminary research that PTC is significantly associated with pathologically confirmed HT. We found two AAs, lysine and alanine, that can perform diagnostic functions in distinguishing PTC1 from PTC0