Role of cathepsin A and cathepsin C in the regulation of glycosidase activity

Increased tissue activity of cathepsin A and cathepsin C can be observed in many pathological conditions. It is associated with an enhanced degradation of glycosaminoglycans, proteoglycans, and glycoproteins, and results in their decreased tissue content. Cathepsin C releases the glycosidases from complexes formed with cathepsin A, and reinstates their activity. In this review a current state of knowledge is presented concerning the regulation of selected glycosidases activity by cathepsin A (EC 3.4.16.1) and C (EC 3.4.14.1).     

The activity of cathepsin D in saliva of cystic fibrosis patients

Cystic fibrosis (CF) is genetically determined illness, which is caused by the mutation in the CFTR gene. CFTR protein is also expressed in epithelial cells of parotid glands, therefore parotid glands are also affected in CF patients. Cathepsin D is one of the proteolitic cascade enzymes. Physiological wearing out result in occurrence of trace quantities of this enzyme in serum and body fluids, including saliva. Among different enzymes, saliva contains cathepsin D (CTSD, EC 3.4.23.5). The aim of this study was to determine cathepsin D activity in mixed saliva in cystic fibrosis patients and healthy controls. The study was performed in a group of 26 CF patients (10F, 16M). The results obtained in CF group was compared with the results of thirty healthy subjects (12F, 14M). From each subject 8 ml of mixed saliva was obtained: before and after the stimulation of saliva excretion using paraffin pledgets. Protein and glycoprotein content was assessed using Winzler's method. Protein concentration in controls and CF group before stimulation of excretion was 1.15+/-0.714 mg/mL and 1.54+/-0.925 mg/mL. After stimulation protein concentration in saliva has lowered to 0.88+/-0.77 mg/mL in CF group and 1.24+/-1.213 mg/mL in controls. Glycoprotein concentration in controls and in CF group was respectively: before stimulation 1.08+/-0.271 mg/mL and 1.05+/-0.344 mg/mL; after stimulation 0.92+/-0.292 mg/mL and 0.86+/-0.283 mg/mL. The activity of CTSD in controls was 45.9+/-24.98 Tyr nmol/mL/4h before stimulation and 109.3+/-56.94 Tyr nmol/mL/4h after stimulation of excretion. In CF group CTSD activity before stimulation was 134.5+/-81.80 Tyr nmol/mL/4h and after stimulation 134.4+/-62.18 Tyr nmol/mL/4h. Comparing the CTSD activity in both groups statistically significant difference has been revealed in samples collected before stimulation of excretion (p=0.013). The activity of cathepsin D in saliva of cystic fibrosis patient is significantly higher than in healthy controls before the stimulation of excretion with paraffin pledgets.     

Phytophthora austrocedrae sp. nov., a new species associated with Austrocedrus chilensis mortality in Patagonia (Argentina)

Phytophthora austrocedrae is a new species isolated from necrotic lesions of stem and roots of Austrocedrus chilensis. It is a homothallic species characterized by semipapillate sporangia, oogonia with amphigynous antheridia, and very slow growth (1–2 mm d⁻¹ on V-8 agar at 17.5 °C optimum temperature). Phylogenetic analysis of ITS rDNA sequence indicates that its closest relative is Phytophthora syringae, another species frequently isolated from soil and streams in A. chilensis forests.     

Chemiluminescent optical fiber immunosensor for detection of autoantibodies to ovarian and breast cancer-associated antigens

We report herein the development of an optical fiber based chemiluminescent immunosensor for detection of the native autoimmune response to GIPC-1, a PDZ containing protein involved in regulation of G-protein signaling. The recombinant protein GIPC-1 was expressed in bacteria, purified, refolded and conjugated to the tip of an optical fiber. A human monoclonal 27.B1 IgM isolated from a breast cancer patient, which targets the GIPC-1 protein, was used for calibration of the immunosensor and was detected down to a concentration of 30 pg/ml. We determined that the fiber-optic immunosensor had a detection limit 50 times lower than chemiluminescent ELISA, and approximately 500 times lower than colorimetric ELISA. In addition, sera from 11 ovarian cancer patients, 22 breast cancer patients and asymptomatic controls were tested for the presence of IgM anti-GIPC-1 autoantibodies in their serum using the two methods. The immunosensor assay detected 54% and 77% GIPC-1 positive sera within ovarian and breast cancer patients, respectively, as compared to chemiluminescent ELISA, which only detected 18% and 27%, respectively. We envision that this immunosensor may serve as a diagnostic tool for screening women for ovarian and breast cancer at an early stage, thus increasing their chance of survival.     

Season of diagnosis is a predictor of cancer survival. Sun-induced vitamin D may be involved: a possible role of sun-induced Vitamin D

The calcidiol level in a group of Norwegians (14,000 individuals, age range 16–80) was found to be highest in late summer. The seasonal variation was larger for young than for old persons. The calcitriol concentration was practically constant throughout the year. Younger persons had less calcidiol and more calcitriol than older persons, indicating that the conversion of calcidiol to calcitriol is more efficient in younger persons.

A seasonal variation of prognosis of cancer (colon-, breast-, prostate- cancer and Hodgkin lymphoma) was found. The survival is highest for summer and autumn diagnosis, corresponding to maximal calcidiol levels. Thus, calcidiol may act synergistically with traditional treatment modalities.

In view of these calcitriol and calcidiol data, the seasonal variation of cancer survival may be related to the calcidiol gradient, indicating that this Vitamin D metabolite may be more important than believed so far.     

A positive relationship between body height and the testosterone response to physical exercise

Human male height is one of the most conspicuous sexually dimorphic, phenotypic characteristics that affect how men are perceived both by men and women, impacting mate selection and intra-sexual competition. Testosterone is a key hormone linked to morphological masculinity and advantage in intra-sexual competition. To date, there have been limited studies linking height with testosterone levels. Here, we examined the change in circulating testosterone levels after physical exercise in 97 healthy and physically active men. Our results show that there was a significant relationship between male stature and the change in testosterone levels, whereas there was no such link between body height and circulating testosterone levels. Therefore, our findings provide evidence that height may indicate male’s adaptive capabilities to physiologically mobilize their bodies when it is needed and/or beneficial.     

A Comprehensive,Simulation-Based Approach to Teaching Clinical Skills: The Medical Students’ Perspective

The purpose of this study was to determine if third-year medical students participating in a mandatory 12-week simulation course perceived improvement in decision-making, communication, and teamwork skills. Students participated in or observed 24 acute emergency scenarios. At 4-week intervals, students completed 0-10 point Likert scale questionnaires evaluating the curriculum and role of team leader. Linear contrasts were used to examine changes in outcomes. P-values were Bonferroni-corrected for multiple pairwise comparisons. Student evaluations (n = 96) demonstrated increases from week 4 to 12 in educational value (p = 0.006), decision-making (p < 0.001), communication (p = 0.02), teamwork (p = 0.01), confidence in management (p < 0.001), and translation to clinical experience (p < 0.001). Regarding the team leader role, students reported a decrease in stress (p = 0.001) and increase in ability to facilitate team function (p < 0.001) and awareness of team building (p = <0.001). Ratings demonstrate a positive impact of simulation on both clinical management skills and team leadership skills. A simulation curriculum can enhance the ability to manage acute clinical problems and translates well to the clinical experience. These positive perceptions increase as the exposure to simulation increases.     

Automated Measurement of Microcirculatory Blood Flow Velocity in Pulmonary Metastases of Rats

Because the lung is a major target organ of metastatic disease, animal models to study the physiology of pulmonary metastases are of great importance. However, very few methods exist to date to investigate lung metastases in a dynamic fashion at the microcirculatory level, due to the difficulty to access the lung with a microscope. Here, an intravital microscopy method is presented to functionally image and quantify the microcirculation of superficial pulmonary metastases in rats, using a closed-chest pulmonary window and automated analysis of blood flow velocity and direction. The utility of this method is demonstrated to measure increases in blood flow velocity in response to pharmacological intervention, and to image the well-known tortuous vasculature of solid tumors. This is the first demonstration of intravital microscopy on pulmonary metastases in a closed-chest model. Because of its minimized invasiveness, as well as due to its relative ease and practicality, this technology has the potential to experience widespread use in laboratories that specialize on pulmonary tumor research.