Rhinovirus C15 Induces Airway Hyperresponsiveness via Calcium Mobilization in Airway Smooth Muscle

Rhinovirus (RV) exposure evokes exacerbations of asthma that markedly impact morbidity and mortality worldwide. The mechanisms by which RV induces airway hyperresponsiveness (AHR) or by which specific RV serotypes differentially evoke AHR remain unknown. We posit that RV infection evokes AHR and inflammatory mediator release, which correlate with degrees of RV infection. Furthermore, we posit that rhinovirus C-induced AHR requires paracrine or autocrine mediator release from epithelium that modulates agonist-induced calcium mobilization in human airway smooth muscle. In these studies, we used an ex vivo model to measure bronchoconstriction and mediator release from infected airways in human precision cut lung slices to understand how RV exposure alters airway constriction. We found that rhinovirus C15 (RV-C15) infection augmented carbachol-induced airway narrowing and significantly increased release of IP-10 (IFN-γ-induced protein 10) and MIP-1β (macrophage inflammatory protein-1β) but not IL-6. RV-C15 infection of human airway epithelial cells augmented agonist-induced intracellular calcium flux and phosphorylation of myosin light chain in co-cultured human airway smooth muscle to carbachol, but not after histamine stimulation. Our data suggest that RV-C15-induced structural cell inflammatory responses are associated with viral load but that inflammatory responses and alterations in agonist-mediated constriction of human small airways are uncoupled from viral load of the tissue.

Formaldehyde Induces Rho-Associated Kinase Activity to Evoke Airway Hyperresponsiveness

Formaldehyde, a common indoor air pollutant, exacerbates asthma and synergizes with allergen to induce airway hyperresponsiveness (AHR) in animal models. The mechanisms mediating formaldehyde-induced AHR remain poorly understood. We posit that formaldehyde modulates agonist-induced contractile response of human airway smooth muscle (HASM) cells to elicit AHR. HASM cells were exposed to formaldehyde or vehicle and agonist-induced intracellular Ca²⁺ ([Ca²⁺]_i) and myosin light-chain phosphatase (MYPT1) phosphorylation were determined. Air-liquid interface-differentiated human bronchial epithelial (HBE) cells were exposed to formaldehyde or vehicle and cocultured with HASM cells. Agonist-induced [Ca²⁺]_i and MYPT1 phosphorylation were determined in the cocultured HASM cells. Precision-cut human lung slices were exposed to PBS or varying concentrations of formaldehyde, and then carbachol-induced airway narrowing was determined 24 hours after exposure. HASM cells were transfected with nontargeting or nuclear factor erythroid-derived 2, like 2 (Nrf-2)-targeting small interfering RNA and exposed to formaldehyde or vehicle, followed by determination of antioxidant response (quinone oxido-reductase 1 and thioredoxin 1) and basal and agonist-induced MYPT1 phosphorylation. Formaldehyde enhanced the basal Rho-kinase activity and MYPT1 phosphorylation with little effect on agonist-induced [Ca²⁺]_i in HASM cells. Formaldehyde induced Nrf-2-dependent antioxidant response in HASM cells, although the MYPT1 phosphorylation was independent of Nrf-2 induction. Although HBE cells exposed to formaldehyde had little effect on agonist-induced [Ca²⁺]_i or MYPT1 phosphorylation in cocultured HASM cells, formaldehyde enhanced carbachol-induced airway responsiveness in precision-cut human lung slices. In conclusion, formaldehyde induces phosphorylation of the regulatory subunit of MYPT1, independent of formaldehyde-induced Nrf-2 activation in HASM cells. The findings suggest that the Rho kinase-dependent Ca²⁺ sensitization pathway plays a role in formaldehyde-induced AHR.

Evolution of elective neck dissection in N0 laryngeal cancer

Management of cervical lymph node metastasis is one of the most challenging problems facing clinicians dealing with head and neck cancer. A retrospective evaluation has been made of results in N0 laryngeal cancer patients treated from 1978 to date by comparing historical data reported in related papers previously published by our institution. The medical records of 2207 consecutive patients with cN0 SCC of the larynx were used as the source of data in the present study. Together with primary treatment, 759 (34.4%) received at least unilateral elective neck dissection, while the remaining 1448 (65.6%) were admitted to a wait-and-see protocol. Overall, in the electively dissected patients (ED): 128 (16.9%) cases were submitted to classical radical neck dissection, while 403 (53.1%) cases were submitted to functional neck dissection (FND) and 228 (30.0%) cases to jugular node dissection (JND, removing Level II, III and IV). In 125 of the ED group, a neck procedure on the contralateral N0 neck was associated, of which 15 were RNDs, 35 FNDs and 75 JNDs, respectively. Based on this large series population, the change in the philosophy was evaluated concerning elective neck treatment in N0 laryngeal cancer, from RND through FND towards JND. As far as concerns the reliability as a staging procedure, no statistically significant difference was found between RND, FND and JND (p = 0.794). The 5-year neck recurrence rate, as estimated by the Kaplan Meier, method, for all ED patients, was 7.7%. No significant difference in the rate of 5-year neck recurrence was detected between RND, FND and JND groups (p = 0.178). In the survival curves, no differences, in terms of actuarial survival by Kaplan Meier analysis, were observed, in our series, as far as concerns type of elective neck dissection performed (p = 0.222). In conclusion, following a critical revision of 25 years' experience, at our Institution, in the management of cN0 necks in laryngeal cancer patients, definitive changes were observed in the surgical approach to the treatment of occult disease in cN0 cases. JND, compared to more extensive neck dissections, did not show statistically significant differences in terms of neck control (p = 0.233), in terms of impact on survival (p = 0.122) and in terms of accuracy as staging procedure (p = 0.794).

Effect of protein dose on serum glucose and insulin response to sugars

To clarify the effects of protein on insulin and glucose response to sugars, 14 healthy normal-weight males and females were fed test meals containing 0, 15.8, 25.1, 33.6, and 49.9 g protein along with approximately 58 g carbohydrate. Serum samples were obtained at fasting time zero and 15, 30, 60, and 120 min postprandial. Mean areas of the glucose curves above fasting decreased with increasing protein dose. Protein-containing meals produced significantly lower (p less than 0.01) areas than the protein-free meal and the relationship between blood glucose area and protein dose was significant (p less than 0.001). Protein-containing meals produced significantly greater (p less than 0.01) insulin areas compared with the protein-free meal. However, no differences in insulin areas among the protein-containing meals were observed. These data support previous studies showing a blood glucose moderating and insulin-enhancing effect of protein ingestion.

Effect of increasing levels of hard wheat fiber on fecal weight, minerals and steroids and gastrointestinal transit time in healthy young women

Hard red wheat bran (HRWB) baked in a yeast-leavened bread was fed to 36 healthy young college women consuming a basal diet of traditional foods, which contained 15 +/- 3 g/d dietary fiber (DF). Three levels of HRWB were added supplying, respectively, 5.7, 17.1 and 28.5 g/d DF; an additional treatment group did not receive any HRWB. Fecal collections were carried out in the last 5 d of treatment. Fecal wet weight, fecal dry weight and fecal ash increased significantly for each increase in HRWB (P less than 0.05). Fecal dry matter percent changed significantly only at the highest level of HRWB (P less than 0.05). After accounting for the minerals in the HRWB, there was an increased fecal loss of Ca, but not of Zn, Cu, Fe or Mg compared to the women fed no HRWB. HRWB at a level of 17.2 g/d induced faster transit times (TT) than no HRWB and 66 g/d HRWB induced faster TT than either 17.2 or 39.6 g/d HRWB (P less than 0.05). Total daily fecal steroids were not altered by changes in HRWB. Daily total bile acid excretion increased significantly (P less than 0.05) at the two higher levels of HRWB due primarily to higher excretion of chenodeoxycholic acid.

Skeletal muscle leucine incorporation and testosterone uptake in exercised guinea pigs

We examined the changes induced by daily treadmill exercise on body weights, plantaris muscle weights, plantaris protein concentrations, and L-leucine-4,5-3H incorporation into plantaris muscles of normal and castrated young male guinea pigs and of castrated animals receiving testosterone replacement therapy, and compared the testosterone-1,2-3H uptake by plantaris muscles of trained normal guinea pigs to that of untrained animals. Trained animals exhibited significantly lower body and muscle weights and greater labeled leucine incorporation into sarcoplasmic and myofibrillar proteins but did not show significant changes in protein concentrations or labeled testosterone uptake. The level of physical activity of the young animals studied appeared to be more important than gonadal endocrine function in altering protein metabolism and muscle and body weights. Because hypertrophy did not occur in the trained plantaris muscles, which had elevated rates of labeled leucine incorporation, it appears that the trained animals had a higher muscle protein turnover rate. It seems unlikely that testosterone plays an important role in these activity-related phenomena.

Digestive Secretion of Dionaea muscipula (Venus's Flytrap)

The digestive fluid of Dionaea muscipula has been studied with respect to its protein content as a function of time after entrapment of protein material and some enzymes of the secretion. Maximum secretion of enzyme occurs within the first 3 days of the digestive cycle and protein reaches its maximum at 4 days. Phosphatase, proteinase, nuclease and amylase have been observed in the secretion. The enzymes have acid pH optima and the proteinase has a molecular weight of about 40,000.