Transmission of Coxiella burnetii by ingestion in mice.

Coxiella burnetii, the causative agent of Q fever, is widely present in dairy products around the world. It has been isolated from unpasteurised milk and cheese and can survive for extended periods of time under typical storage conditions for these products. Although consumption of contaminated dairy products has been suggested as a potential route for transmission, it remains controversial. Given the high prevalence of C. burnetii in dairy products, we sought to examine the feasibility of transmitting the major sequence types (ST16, ST8 and ST20) of C. burnetii circulating in the United States. We delivered three strains of C. burnetii, comprising each sequence type, directly into the stomachs of immunocompetent BALB/c mice via oral gavage (OG) and assessed them for clinical symptoms, serological response and bacterial dissemination. We found that mice receiving C. burnetii by OG had notable splenomegaly only after infection with ST16. A robust immune response and persistence in the stomach and mesenteric lymph nodes were observed in mice receiving ST16 and ST20 by OG, and dissemination of C. burnetii to peripheral tissues was observed in all OG infected mice. These findings support the oral route as a mode of transmission for C. burnetii.

CRISPR-based gene editing enables FOXP3 gene repair in IPEX patient cells.

The prototypical genetic autoimmune disease is immune dysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome, a severe pediatric disease with limited treatment options. IPEX syndrome is caused by mutations in the forkhead box protein 3 (FOXP3) gene, which plays a critical role in immune regulation. As a monogenic disease, IPEX is an ideal candidate for a therapeutic approach in which autologous hematopoietic stem and progenitor (HSPC) cells or T cells are gene edited ex vivo and reinfused. Here, we describe a CRISPR-based gene correction permitting regulated expression of FOXP3 protein. We demonstrate that gene editing preserves HSPC differentiation potential, and that edited regulatory and effector T cells maintain their in vitro phenotype and function. Additionally, we show that this strategy is suitable for IPEX patient cells with diverse mutations. These results demonstrate the feasibility of gene correction, which will be instrumental for the development of therapeutic approaches for other genetic autoimmune diseases.

Studies on the mechanism of inhibition of tRNA methylation by 3,4-dihydroxyphenylethylamine.

A Lineweaver-Burk analysis of a kinetic study of tRNA methylation by a 30-50% (NH4)2SO4 fraction from a weanling rat liver extract showed competitive inhibition with a Km for S-adenosylmethionine = 0.66 - 10(-6) M and a Ki for 3,4-dihydroxyphenylethylamine (dopamine) = 4 - 10(-5) M. The dopamine-inhibited methylation of tRNA appears to be linear with time. Rapid-flow dialysis studies indicated a S-adenosylmethionine binding constant of 0.65 - 10(-6) M. Dopamine appeared to interfere with the binding of S-adenosylmethionine to the weanling rat liver protein preparation but did not affect the binding of S-adenosylmethionine to protein in several systems in which dopamine did not inhibit tRNA methylase activity.

Effects of amines on macromolecular methylation.

Histone methylation by extracts of rat brain or liver was inhibited and tRNA methylation stimulated by the addition of a number of naturally occurring polyamines. The effect was age independent although the methylase activities are highly age-related. Spermine and/or histamine stimulated methylation of cytosine and adenine to a far grease activity, were more sensitive to inhibition by adenosine than were liver extracts. Adenosine inhibited the methylation of guanine to a greater extent than of cytosine or adenine. Methylation of both tRNA and histone by liver enzyme was inhibited by L-dopa, dopamine and epinephrine. Methylation by brain enzyme was also blocked, but less extensively. The response of liver extracts to these catecholamines was highly age-related. The phenolic amines, octopamine, synephrine, serotonin and tyramine, stimulated tRNA methylation slightly while inhibiting histone methylation by both liver and brain extracts and these effects showed no age dependency. Analysis of the data suggests that most of these compounds do not act by competing for the available S-adenosylmethionine.

Intra-abdominal desmoplastic small round-cell tumor. Report of 19 cases of a distinctive type of high-grade polyphenotypic malignancy affecting young individuals.

Nineteen cases of a distinctive type of malignant small-cell tumor are presented. The main features of the entity are as follows: a predilection for adolescent males (mean age: 18.6 years); predominant or exclusive intra-abdominal location, with only inconstant and secondary organ involvement; nesting pattern of growth; focal rhabdoid features; intense desmoplastic reaction; immunohistochemical reactivity for epithelial [keratin, epithelial membrane antigen (EMA)], neural [neuron-specific enolase (NSE)], and muscle (desmin) markers; and highly aggressive behavior. It is proposed that this represents yet another member of the continuously enlarging and evolving family of small round (blue) cell tumors of infancy and childhood that features, more than any other member of this group, the capacity for simultaneous multidirectional phenotypical expression.

Koilocytosis preceding squamous cell carcinoma in situ of uterine cervix.

Association of koilocytic changes with cervical squamous cell carcinoma is well documented. The studies of such concurrent association may miss those cases of papillomavirus infection where cytomorphologic expression of virus has disappeared by the time carcinoma appears. The authors studied cytologic material before the diagnosis was made of cervical squamous cell carcinoma in situ in 25 patients. Twenty-two (88%) of the 25 patients showed koilocytosis compared with only 6 out of 57 (10.5%) in the control group. The findings of this study support a possible predisposing role of papillomavirus in squamous cell carcinoma of the cervix.