Mesenchymal Stem Cells Yield Transient Improvements in Motor Function in an Infant Rhesus Macaque with Severe Early-Onset Krabbe Disease.

Krabbe disease, or globoid cell leukodystrophy, is a rare disorder caused by deficient galactosylceramidase activity and loss of myelin-forming oligodendrocytes, resulting in progressive demyelination and severely impaired motor function. Disease symptoms in humans appear within 3-6 months of age (early infantile) and manifest as marked irritability, spasticity, and seizures. The disease is often fatal by the second year of life, with few effective treatment options. Herein we evaluated the therapeutic potential of mesenchymal stem cells (MSCs) administered intracranially to a 1-month-old rhesus macaque diagnosed with severe early-onset Krabbe disease that displayed neurologic and behavioral symptoms similar to those of human patients. The infant was subjected to physical and neurological behavior examinations and nerve conduction velocity tests to assess efficacy, and outcomes were compared with age-matched normal infants and Krabbe-affected rhesus monkeys with late-onset disease. Changes in major blood lymphocyte populations were also monitored to assess host immune cell responses. MSC administration resulted in transient improvements in coordination, ambulation, cognition, and large motor skills, which correlated with increased peripheral nerve conduction velocities and decreased latencies. Improvements also corresponded to transient increases in peripheral blood lymphocyte counts, but secondary challenge failed to elicit allo-antibody production. Nevertheless, white cell and neutrophil counts showed dramatic increases, and CD20+ B cell counts underwent a precipitous decline at late stages of disease progression. Correlative data linking MSC administration to transient improvements in motor function suggest that MSCs should be evaluated further as an experimental therapy for rare neurodegenerative diseases. Stem Cells Translational Medicine 2017;6:99-109.

The development of vaccine viruses against pandemic A(H1N1) influenza.

Wild type human influenza viruses do not usually grow well in embryonated hens' eggs, the substrate of choice for the production of inactivated influenza vaccine, and vaccine viruses need to be developed specifically for this purpose. In the event of a pandemic of influenza, vaccine viruses need to be created with utmost speed. At the onset of the current A(H1N1) pandemic in April 2009, a network of laboratories began a race against time to develop suitable candidate vaccine viruses. Two approaches were followed, the classical reassortment approach and the more recent reverse genetics approach. This report describes the development and the characteristics of current pandemic H1N1 candidate vaccine viruses.

Comparative effectiveness of light-microscopic techniques and PCR in detecting Thelohania solenopsae (Microsporidia) infections in red imported fire ants (Solenopsis invicta).

The main goal of this study was to compare the effectiveness of three staining techniques (calcofluor white M2R, Giemsa and modified trichrome), and the polymerase chain reaction (PCR) in detecting the microsporidium Thelohania solenopsae in red imported fire ants (Solenopsis invicta). The effect of the number of ants in a sample on the sensitivity of the staining techniques and the PCR, and the effect of three DNA extraction protocols on the sensitivity of PCR were also examined. In the first protocol, the ants were macerated and the crude homogenate was used immediately in the PCR. In the second protocol, the homogenate was placed on a special membrane (FTA card) that traps DNA, which is subsequently used in the PCR. In the third protocol, the DNA was purified from the homogenate by traditional phenol-chloroform extraction. Except for PCR using FTA cards, the sensitivity (number of samples positive for T. solenopsae) of all detection techniques increased with the number of ants in the sample. Overall, Giemsa was the least sensitive of all detection techniques. Calcofluor was more sensitive than modified trichrome with ants from one site and was equally as sensitive as PCR with crude DNA or a FTA card with ants from both sites. Trichrome staining was equally as sensitive as PCR with a FTA card at both sites, but it was less sensitive than PCR with crude DNA at one site. PCR on FTA cards was less sensitive than PCR with crude DNA for ants from one site but not the other. There was no difference whether crude or phenol-chloroform purified DNA was used as template. In summary, the results of this study show that PCR based on a crude DNA solution is equal to or more sensitive in detecting T. solenopsae than the other detection techniques investigated, and that it can be used as a reliable diagnostic tool for screening field samples of S. invicta for T. solenopsae. Nevertheless, ant smear stained with calcofluor or modified trichrome should be used to buttress findings from PCR.