ABSTRACT
The intracellular coccobacilli Rickettsia rickettsii causes Rocky Mountain Spotted Fever, a potentially fatal illness. This bacterium is transmitted to humans through a tick vector. Patients classically present with a triad of symptoms, including fever, headache, and a rash that begins on the extremities and spreads proximally to the trunk. Diagnosis of this disease can prove difficult when patients have unusual symptoms, such as hypertensive crisis. In this case report, we present a 29-year-old male who arrived at the emergency room with altered mental status and a hypertensive crisis after his family reported one week of changes in his behavior. The patient had no evidence of ticks, tick bites, fever, or rash. Positive findings in the emergency room included a WBC of 14.9 × 109. All other physical exams, imaging, and laboratory findings were non-contributory. The patient was promptly given IV hydralazine to control his blood pressure and empiric IV ceftriaxone for potential infection, and he was admitted for observation. Over the course of three days, WBC levels decreased, and his altered mental status improved. On day 3, the patient remembered a tick crawling across his hand, and this prompted the ordering of immunoglobulin levels for tick-borne illnesses. IgM for RMSF was positive. This case presentation illustrates the need for clinicians to keep the potential diagnosis of RMSF high on the differential, even in the presence of a paucity of symptoms, as prompt treatment with doxycycline can be lifesaving. This case may also be one of the first reported in the literature of hypertension being a symptom of Rocky Mountain Spotted Fever. It is plausible, however, that this patient's hypertension was due to an acute stress response.
ABSTRACT
Epithelial multiciliated cells (MCCs) use motile cilia to direct external fluid flow, the disruption of which is associated with human diseases in a broad array of organs such as those in the respiratory, reproductive, and renal systems. While many of the signaling pathways that regulate MCC formation in these organ systems have been identified, similar characterization of MCC differentiation in the developing olfactory system has been lacking. Here, using live cell tracking, targeted cell ablation, and temporally-specific inhibition of the Notch signaling pathway, we identify the earliest time window of zebrafish olfactory MCC (OMCC) differentiation and demonstrate these cells' derivation from peridermal cells. We also describe regionally segregated Notch signaling across time points of rapid OMCC differentiation and show that Notch signaling downregulation yields an increase in OMCCs, suggesting that OMCC fate is normally repressed in a region-specific manner during olfactory development. Finally, we describe Notch signaling's regulation of the differentiation/ciliogenesis-associated genes foxj1a and foxj1b. Taken together, these findings provide new insights into the origins and developmental programming of OMCCs in vivo.
