Dynamic in vivo imaging of cerebral blood flow and blood–brain barrier permeability

The brain is characterized by an extremely rich blood supply, regulated by changes in blood vessel diameter and blood flow, depending on metabolic demands. The blood–brain barrier (BBB)—a functional and structural barrier separating the intravascular and neuropil compartments—characterizes the brain's vascular bed and is essential for normal brain functions. Disruptions to the regional cerebral blood supply, to blood drainage and to BBB properties have been described in most common neurological disorders, but there is a lack of quantitative methods for assessing blood flow dynamics and BBB permeability in small blood vessels under both physiological and pathological conditions. Here, we present a quantitative image analysis approach that allows the characterization of relative changes in the regional cerebral blood flow (rCBF) and BBB properties in small surface cortical vessels. In experiments conducted using the open window technique in rats, a fluorescent tracer was injected into the tail vein, and images of the small vessels at the surface of the cortex were taken using a fast CCD camera. Pixel-based image analysis included registration and characterization of the changes in fluorescent intensity, followed by cluster analysis. This analysis enabled the characterization of rCBF in small arterioles and venules and changes in BBB permeability. The method was implemented successfully under experimental conditions, including increased rCBF induced by neural stimulation, bile salt-induced BBB breakdown, and photothrombosis-mediated local ischemia. The new approach may be used to study changes in rCBF, neurovascular coupling and BBB permeability under normal and pathological brain conditions.     

Secular trends in the epidemiology of pediculosis capitis and pubis among Israeli soldiers: a 27-year follow-up

BACKGROUND: Pediculosis capitis and pubis are not mandatorily reported diseases in most countries. Thus, the reported rates of these diseases in large populations are usually inaccurate and based on estimations. OBJECTIVE: To describe the global epidemiology of pediculosis capitis and pubis in the Israeli Defense Force. METHODS: We analyzed the data obtained from the routine and mandatory reporting of every individual case of pediculosis capitis and pubis to the Army Health Branch Epidemiology Department since 1972 and 1973, respectively. RESULTS: During this period, epidemics of pediculosis capitis and pubis were observed between 1973 and 1985 and 1972 and 1987, with 17.7- and 3.9-fold increases in incidence, respectively. These two epidemics were followed by a sharp decline in morbidity (113.6- and 13.6-fold between 1981 and 1999 and 1984 and 1999, respectively) to the present. CONCLUSIONS: A number of factors could be responsible for the observed decline in morbidity, e.g. socioeconomic, pharmacologic, environmental, or prevention policy modifications. The rates of pediculosis capitis and pubis have continuously declined since the last epidemic of 1972-1987, indicating the influence of these and possibly other factors.     

Towards automatic skill evaluation: detection and segmentation of robot-assisted surgical motions.

This paper reports our progress in developing techniques for "parsing" raw motion data from a simple surgical task into a labeled sequence of surgical gestures. The ability to automatically detect and segment surgical motion can be useful in evaluating surgical skill, providing surgical training feedback, or documenting essential aspects of a procedure. If processed online, the information can be used to provide context-specific information or motion enhancements to the surgeon. However, in every case, the key step is to relate recorded motion data to a model of the procedure being performed.Robotic surgical systems such as the da Vinci system from Intuitive Surgical provide a rich source of motion and video data from surgical procedures. The application programming interface (API) of the da Vinci outputs 192 kinematics values at 10 Hz. Through a series of feature-processing steps, tailored to this task, the highly redundant features are projected to a compact and discriminative space. The resulting classifier is simple and effective.Cross-validation experiments show that the proposed approach can achieve accuracies higher than 90% when segmenting gestures in a 4-throw suturing task, for both expert and intermediate surgeons. These preliminary results suggest that gesture-specific features can be extracted to provide highly accurate surgical skill evaluation.     

Adenoid cystic carcinoma of the salivary glands: a 20-year review with long-term follow-up

The behavior of adenoid cystic carcinoma (ACC) of the salivary glands has been shown to be unpredictable in terms of local and distant spread and mortality. We retrospectively studied 35 operations in 34 patients who had had a pathologic diagnosis of ACC of the salivary glands and who had been treated over a 20-year period and followed for a minimum of 10 years. We analyzed the effect that different factors had on outcomes. The site of origin appeared to be an important factor in survival rates; survival among patients with tumors that had originated in the parotid gland was fairly good, while survival among those with tumors that originated in the minor salivary glands was significantly worse. TNM staging was another significant factor in survival. Other poor prognostic indicators were local spread, nodal positivity, distant metastasis, and local and regional recurrence. Radiation and chemotherapy did not appear to be beneficial for patients with advanced disease. We recommend radical surgery with complete resection for all patients with ACC of the salivary glands and a careful assessment of the neck in patients with minor salivary gland tumors.     

Target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (t-SNAREs) differently regulate activation and inactivation gating of Kv2.2 and Kv2.1: Implications on pancreatic islet cell Kv channels

We have hypothesized that the plasma membrane protein components of the exocytotic soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE) complex, syntaxin 1A and SNAP-25, distinctly regulate different voltage-gated K+ (Kv) channels that are differentially distributed. Neuroendocrine islet cells (alpha, beta, delta) uniformly contain both syntaxin 1A and SNAP-25. However, using immunohistochemistry, we show that the different pancreatic islet cells contain distinct dominant Kv channels, including Kv2.1 in beta cells and Kv2.2 in alpha and delta cells, whose interactions with the SNARE proteins would, respectively regulate insulin, glucagon and somatostatin secretion. We therefore examined the regulation by syntaxin 1A and SNAP-25 of these two channels. We have shown that Kv2.1 interacts with syntaxin 1A and SNAP-25 and, based on studies in oocytes, suggested a model of two distinct modes of interaction of syntaxin 1A and the complex syntaxin 1A/SNAP-25 with the C terminus of the channel. Here, we characterized the interactions of syntaxin 1A and SNAP-25 with Kv2.2 which is highly homologous to Kv2.1, except for the C-terminus. Comparative two-electrode voltage clamp analysis in oocytes between Kv2.2 and Kv2.1 shows that Kv2.2 interacts only with syntaxin 1A and, in contrast to Kv2.1, it does not interact with the syntaxin 1A/SNAP-25 complex and hence is not sensitive to the assembly/disassembly state of the complex. The distinct regulation of these closely related channels by SNAREs may be attributed to differences in their C termini. Together with the differential distribution of these channels among islet cells, their distinct regulation suggests that the documented profound down-regulation of islet SNARE levels in diabetes could distort islet cell ion channels and secretory responses in different ways, ultimately contributing to the abnormal glucose homeostasis.