Association of plasma tryptophan concentration with periaqueductal gray matter functional connectivity in migraine patients

Altered periaqueductal gray matter (PAG) functional connectivity contributes to brain hyperexcitability in migraine. Although tryptophan modulates neurotransmission in PAG projections through its metabolic pathways, the effect of plasma tryptophan on PAG functional connectivity (PAG-FC) in migraine has not been investigated yet. In this study, using a matched case-control design PAG-FC was measured during a resting-state functional magnetic resonance imaging session in migraine without aura patients (n = 27) and healthy controls (n = 27), and its relationship with plasma tryptophan concentration (TRP) was assessed. In addition, correlations of PAG-FC with age at migraine onset, migraine frequency, trait-anxiety and depressive symptoms were tested and the effect of TRP on these correlations was explored. Our results demonstrated that migraineurs had higher TRP compared to controls. In addition, altered PAG-FC in regions responsible for fear-cascade and pain modulation correlated with TRP only in migraineurs. There was no significant correlation in controls. It suggests increased sensitivity to TRP in migraine patients compared to controls. Trait-anxiety and depressive symptoms correlated with PAG-FC in migraine patients, and these correlations were modulated by TRP in regions responsible for emotional aspects of pain processing, but TRP did not interfere with processes that contribute to migraine attack generation or attack frequency.

Effects of Tryptophan on the Polymorphic Transformation of Calcium Carbonate: Central Composite Design, Characterization, Kinetics, and Thermodynamics

The objectives of this study were to: (i) determine the effects of tryptophan on the polymorphic phase transformation of CaCO3, (ii) investigate the thermal degradation characteristics of CaCO3 in terms of kinetics and thermodynamics using the Coats–Redfern method, and (iii) assess the influence of the experimental conditions on the vaterite composition of CaCO3 using response surface methodology based on central composite design. First, the CaCO3 crystals were prepared and analyzed using XRD, FTIR, SEM, BET, AFM, and zeta potential analysis. Based on the characterization results, the shape of the CaCO3 crystals changed from smooth cubic calcite crystals to porous irregular spherical-like vaterite crystals with increasing tryptophan concentration. Meanwhile, the kinetic results showed that the thermal degradation of CaCO3 followed the shrinkage geometrical spherical mechanism, R3 and the average activation energy was 224.6 kJ/mol. According to the results of the experimental design, the tryptophan concentration was the most influential variable affecting the relative fraction of vaterite in the produced crystals. It can be concluded that tryptophan is important for better understanding and controlling the polymorph, size, and morphology of CaCO3 crystals.

Isolation and screening producing growth regulator cyanobacteria strains

Cyanobacteria are photosynthetic microorganisms that have their biosynthesis capacities for secondary compounds with the high application value. They can produce a variety of bioactive compounds such as lipopeptides, fatty acids, toxins, carotenoids, vitamins and plant growth regulators which could be released into the culture medium. The present study aimed to isolate and screen cyanobacteria strains that could synthesize phytohormone, indole-3-acetic acid (IAA) from paddy soild and fresh water ecosystems (canals, river). Soil and water samples were collected from diferent provinces (Bac Giang, Thanh Hoa and Hue). Indole-3-acetic acid was extracted from the culture of isolated cyanobacteria strains and identified using the Salkowski method. As a result, total 10 strains belonging to 4 genera including Nostoc, Anabena, Geitlerinema and Planktothricoides were susscessful isolated from river, canal and rice field. The morphology of isolated taxa was characterized and monoalgal cultures were grown in BG 11 medium. In L-tryptophan-enriched growth media, all cyanobacteria strains in this research were able to biosynthesize growth regulators with IAA concentrations ranging from 9.1 to 95 µg/mL. Among the isolated cyanobacteria strains, the Planktothricoides raciborskii showed potential for the production of IAA even in the absence of tryptophan in the culture medium. Research results of the L-tryptophan concentration effect on the ability of IAA biosynthesis of this cyanobacteria strain showed that IAA concentration increased gradually and reached the highest value (118,28 ± 2,00 µg/mL) when supplementing L- tryptophan in culture medium at 900 µg/mL. The capacity of producing IAA makes these isolated cyanobacteria an appopriate cadidate for agricultural biotechnology.

Tryptophan Intake and Tryptophan Losses in Hemodialysis Patients: A Balance Study

Tryptophan depletion is common in hemodialysis patients. The cause of this depletion remains largely unknown, but reduced nutritional tryptophan intake, losses during dialysis or an increased catabolism due to an inflammatory state are likely contributors. Currently, little is known about tryptophan homeostasis in hemodialysis patients. We assessed dietary tryptophan intake, measured plasma tryptophan during dialysis, and measured the combined urinary and dialysate excretion of tryptophan in 40 hemodialysis patients (66 ± 15 years and 68% male). Patients had low tryptophan concentrations (27 ± 9 µmol/L) before dialysis. Mean dietary tryptophan intake was 4454 ± 1149 µmol/24 h. Mean urinary tryptophan excretion was 15.0 ± 12.3 μmol/24 h, dialysate excretion was 209 ± 67 μmol/24 h and combined excretion was 219 ± 66 µmol/24 h, indicating only 5% of dietary tryptophan intake was excreted. No associations were found between plasma tryptophan concentration and tryptophan intake, plasma kynurenine/tryptophan ratio or inflammatory markers. During dialysis, mean plasma tryptophan concentration increased 16% to 31 ± 8 µmol/L. Intradialytic increase in plasma tryptophan was associated with a lower risk of mortality, independent of age, sex and dialysis vintage (HR: 0.87 [0.76–0.99]; P = 0.04). Tryptophan intake was well above the dietary recommendations and, although tryptophan was removed during dialysis, mean plasma tryptophan increased during dialysis. The cause of this phenomenon is unknown, but it appears to be protective.

Uji Potensi Bakteri Endofit Kitinolitik Tanaman Padi (Oryza sativa L.) Sebagai Penghasil Hormon IAA (Indole Acetic Acid)

IAA (Indole Acetic Acid) is a hormone in plants that was role in the cleavage of roots, inhibits the growth of side shoots, stimulate cell division and the formation of xylem and phloem tissue. This study aimed to test the potential of endophytic bacteria chitinolytic rice crop as hormone-producing IAA. This study uses 9 isolates of endophytic bacteria chitinolytic rice plants in isolation during practical work. The experiment consisted of 15 treatments and 3 replications. This study uses a randomized block design. The treatments tryptophan concentration combined with a variation pH, the endophytic bacteria grown on media chitinolytic tryptophan concentration of 0 mg/L, 102 mg/L, 204 mg/L, 306 mg/L and 408 mg/L are combined with pH 5, 7 and 9. the treatment was observed for 48 hours and observation once every 3 hours. The measured variable is the result of the production of IAA hormone with the treatment combination of tryptophan with pH. IAA hormone outcome data were analyzed using Analysis of Variance Univariates at level of 95%. IAA hormone qualitative test results showed positive results in bacterial isolates KA12, KA11 and KB24. IAA hormone quantitative results of bacterial isolates producing IAA hormone KA12 high of 2,03 mg/L in the combination treatment of tryptophan 408 mg/L at pH 7 at 24 hours incubation. KA12 bacterial isolates are endophytic bacteria chitinolytic potential to produce hormones IAA, yet the results of data analysis showed that each treatment combination with pH tryptophan to IAA production were not significantly different. Keywords: hormone IAA, chitinolytic endophytic bacteria, tryptophan, pH