[Investigation on seroprevalence of Toxoplasma gondii infections among neonates in Fujian Province].

OBJECTIVE: To investigate the seroprevalence of Toxoplasma gondii infections among neonates in Fujian Province, so as to provide insights into the development of interventions for the prevention and control of congenital toxoplasmosis. METHODS: A total of 1 045 neonates delivered in Fujian Province from 2017 to 2018 were recruited, including 387 preterm infants and 658 full-term infants. Umbilical cord blood was sampled from all neonates, and the seroprevalence of anti-T. gondii IgG antibody was detected and compared between preterm and full-term infants. In addition, elbow venous blood samples were collected from neonates'mothers, and the seroprevalence of anti-T. gondii IgG antibody was detected and compared between preterm and full-term infants'mothers. RESULTS: The overall seroprevalence of anti-T. gondii IgG antibody was 9.38% among the 1 045 neonates in Fujian Province. The seroprevalence of anti-T. gondii IgG antibody was 18.35% in the 387 preterm infants, and there was no significant difference in the seroprevalence of anti-T. gondii IgG antibody between male and female infants (17.69% vs. 18.75%, χ2 = 0.07, P > 0.05). The seroprevalence of anti-T. gondii IgG antibody was 4.10% in the 658 full-term infants, and there was no significant difference in the seroprevalence of anti-T. gondii IgG antibody between male and female infants (4.14% vs. 4.08%, χ2 = 0, P > 0.05). In addition, the overall seroprevalence of anti-T. gondii IgG antibody was 15.02% in all neonates' mothers, and the seroprevalence was significantly greater in preterm infants'mothers than in full-term infant's mothers (20.93% vs. 11.55%, χ2 = 16.79, P < 0.01). CONCLUSIONS: The seroprevalence of T. gondii infections is significantly higher in preterm infants and their mothers than in full-term infants and their mothers. Prenatal detection of T. gondii infections and health education pertaining to toxoplasmosis prevention and control knowledge are required to be strengthened to effectively reduce the incidence of congenital toxoplasmosis.

Measuring the progression of foreign-body reaction to silicone implants using in vivo MR microscopy.

We used in vivo magnetic resonance (MR) microscopy to follow the growth of fibrous capsule as a foreign body reaction to silicone implants in rats. Anesthetized rats were imaged 1, 7, 14, and 28 days after silicone-coated MR imaging coils were sutured to their neck muscles. On the twenty-eighth day, rats were sacrificed and coils and adjacent tissues were removed en bloc and fixed in formalin, reimaged with MR, and sectioned for conventional histology. Three-dimensional (3-D) spin-echo [3DFT] acquisition gave in-plane resolution of 32 x 32 microns in vivo and 16 x 16 microns ex vivo. All MR images showed a diffuse band of elevated signal intensity between the silicone of the coil and adjacent tissue. The border of the hyperintense band was thin and not well defined at seven days post-implantation. From 7-28 days, the band showed relatively homogeneous signal intensity and its thickness increased 44% on the rectus muscle side and 78% on the subcutaneous side. The capsule thickness determined either by MR in vivo and ex vivo microscopy or conventional histology was not significantly different, and there was a significant correlation between thickness measurements among those methods. MR in vivo microscopy provides sufficient resolution and spatial information to serially evaluate the growth of the foreign body fibrous capsule over time, thus achieving greater accuracy and consistency in measurements.

Automated feedback control of body temperature for small animal studies with MR microscopy.

A temperature control system consisting of a thermistor, signal processor, and computer algorithm was developed for magnetic resonance (MR) microscopy of small live animals. With control of body temperature within +/- 0.2 degree C of the set point, heart rate is stabilized and, in turn, repetition time (TR) during cardiac-gated studies is less variable. Thus, image quality and resolution are improved.