Randomized controlled trial of transcranial magnetic stimulation in pregnant women with major depressive disorder.

BACKGROUND: Major depressive disorder (MDD) affects 10% of pregnancies. Because transcranial magnetic stimulation (TMS) is a nonmedication option, psychiatric patients who do not tolerate or prefer to avoid antidepressants are good candidates for TMS. METHOD: In a randomized controlled trial of twenty-two women with MDD in the second or third trimester of pregnancy, subjects were randomized to active TMS (n=11) or sham TMS (n=11). This study took place at a single academic center. Subjects received 20 sessions of TMS to the right dorsolateral prefrontal cortex at 1 Hz as a single train of 900 pulses per session at 100% motor threshold. Estradiol and progesterone and were measured before session 1 and after session 20. RESULTS: Results demonstrated significantly decreased Hamilton Depression Rating Scale (HDRS-17) scores for the active compared to the sham group (p=0.003). Response rates were 81.82% for the active and 45.45% for the sham coil (p=0.088). Remission rates were 27.27% for the active 18.18% for the sham coil (p=0.613). Late preterm birth (PTB) occurred in three women receiving active TMS. All other maternal and delivery outcomes were normal. CONCLUSIONS: Right-sided, low frequency TMS was effective in reducing depressive symptoms in this sample of pregnant women. There may be a possibility that TMS is associated with late PTB although a larger sample size would be needed for adequate power to detect a true difference between groups. This study demonstrated that TMS is low risk during pregnancy although larger trials would provide more information about the efficacy and safety of TMS in this population. This trial shows that an RCT of a biologic intervention in pregnant women with psychiatric illness can be conducted.

Neuromodulation and antenatal depression: a review.

BACKGROUND: Depression during pregnancy affects 5%-8% of women. While the percentage of women in the US taking serotonin reuptake inhibitors during pregnancy has risen over the last decade, pregnant women continue to report that they prefer non-pharmacologic interventions. OBJECTIVE: We review the literature regarding neuromodulation techniques for major depressive disorder during pregnancy. The rationale for their use in this population, new developments, and future directions are discussed. METHODS: A literature search was conducted in PubMed Plus, Ovid Medline, and Embase to collect all articles on neuromodulation for the treatment of depression during pregnancy. Key search words included electroconvulsive therapy, transcranial magnetic stimulation, deep brain stimulation, transcranial direct current stimulation, neuromodulation, depression, and pregnancy. Given the sparse literature, all articles from 1960 to 2014 that addressed the use of neuromodulation in pregnancy were included. CONCLUSION: The data support the use of electroconvulsive therapy in all trimesters of pregnancy for major depressive disorder. New data are emerging for the use of transcranial magnetic stimulation in pregnancy, which is likely safe, but more data are needed before it can be recommended as a primary treatment modality during pregnancy. Other neuromodulation techniques have not been well studied in this population.

pH dependence of amylin fibrillization.

In type 2 diabetics, the hormone amylin misfolds into amyloid plaques implicated in the destruction of the pancreatic ß-cells that make insulin and amylin. The aggregative misfolding of amylin is pH-dependent, and exposure of the hormone to acidic and basic environments could be physiologically important. Amylin has two ionizable residues between pH 3 and 9: the α-amino group and His18. Our approach to measuring the pKa values for these sites has been to look at the pH dependence of fibrillization in amylin variants that have only one of the two groups. The α-amino group at the unstructured N-terminus of amylin has a pKa near 8.0, similar to the value in random coil models. By contrast, His18, which is involved in the intermolecular ß-sheet structure of the fibrils, has a pKa that is lowered to 5.0 in the fibrils compared to the random coil value of 6.5. The lowered pKa of His18 is due to the hydrophobic environment of the residue, and electrostatic repulsion between positively charged His18 residues on neighboring amylin molecules in the fibril. His18 acts as an electrostatic switch inhibiting fibrillization in its charged state. The presence of a charged side chain at position 18 also affects fibril morphology and lowers amylin cytotoxicity toward a MIN6 mouse model of pancreatic ß-cells. In addition to the two expected pKa values, we detected an apparent pKa of ~4.0 for the amylin-derived peptide NAc-SNNFGAILSS-NH2, which has no titratable groups. This pKa is due to the pH-induced ionization of the dye thioflavin T. By using alternative methods to follow fibrillization such as the dye Nile Red or turbidimetry, we were able to distinguish between the titration of the dye and groups on the peptide. Large differences in reaction kinetics were observed between the different methods at acidic pH, because of charges on the ThT dye, which hinder fibril formation much like the charges on the protein.

Inhibition of semen-derived enhancer of virus infection (SEVI) fibrillogenesis by zinc and copper.

Semen-derived enhancer of virus infection (SEVI), a naturally occurring peptide fragment of prostatic acid phosphatase, enhances HIV infectivity by forming cationic amyloid fibrils that aid the fusion of negatively charged virion and target cell membranes. Cu(II) and Zn(II) inhibit fibrillization of SEVI in a kinetic assay using the fibril-specific dye ThT. TEM suggests that the metals do not affect fibril morphology. NMR shows that the metals bind to histidines 3 and 23 in the SEVI sequence. ITC experiments indicate that SEVI forms oligomeric complexes with the metals. Dissociation constants are micromolar for Cu(II) and millimolar for Zn(II). Because the Cu(II) and Zn(II) concentrations that inhibit fibrillization are comparable with those found in seminal fluid the metals may modulate SEVI fibrillization under physiological conditions.