Oyster mushroom cultivation with rice and wheat straw

Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated. The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined. Two size reduction methods, grinding and chopping, were compared. The ground straw yielded higher mushroom growth rate and yield than the chopped straw. The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size. However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased. With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels. Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions. The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3%. The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw.     

Enhanced type 1 immunity after secondary viral challenge in mice primed as neonates

The goal of infant immunization against viral infection is to develop protective long term memory responses. Priming neonatal mice with a low dose of Cas-Br-E murine leukemia virus (Cas) results in adult-like, type 1 protective responses. However, other studies suggest that Ag priming of neonates leads to an increase in type 2 secondary responses even when primary responses were type 1. We assessed whether type 1 CD8+ T cell-mediated responses developed in murine neonates are maintained after secondary challenge with Cas in adulthood. Despite the induction of significant anti-viral CD8+-mediated cytotoxic T lymphocyte and IFN-gamma responses, initial neonatal priming led to a lower frequency of virus-specific T cells compared with adult priming. Adult frequencies were reached in mice primed as neonates only after secondary challenge in adulthood. A nonspecific and transient CD4+-mediated IL-4 response was present in all groups after secondary challenge with Cas or medium, indicating that this rise in type 2 cytokine production was not unique to mice that had been primed as neonates. Rather, type 1 anti-viral memory CD8+ T cell responses developed in neonatal mice are stable, protective, and enhanced after secondary challenge.     

ChAT::Cre transgenic rats show sex-dependent altered fear behaviors,ultrasonic vocalizations and cholinergic marker expression

The cholinergic system is a critical regulator of Pavlovian fear learning and extinction. As such, we have begun investigating the cholinergic system's involvement in individual differences in cued fear extinction using a transgenic ChAT::Cre rat model. The current study extends behavioral phenotyping of a transgenic ChAT::Cre rat line by examining both freezing behavior and ultrasonic vocalizations (USVs) during a Pavlovian cued fear learning and extinction paradigm. Freezing, 22 kHz USVs, and 50 kHz USVs were compared between male and female transgenic ChAT::Cre+ rats and their wildtype (Cre-) littermates during fear learning, contextual and cue-conditioned fear recall, cued fear extinction, and generalization to a novel tone. During contextual and cued fear recall ChAT::Cre+ rats froze slightly more than their Cre- littermates, and displayed significant sex differences in contextual and cue-conditioned freezing, 22 kHz USVs, and 50 kHz USVs. Females showed more freezing than males in fear recall trials, but fewer 22 kHz distress calls during fear learning and recall. Females also produced more 50 kHz USVs during exposure to the testing chambers prior to tone (or shock) presentation compared with males, but this effect was blunted in ChAT::Cre+ females. Corroborating previous studies, ChAT::Cre+ transgenic rats overexpressed vesicular acetylcholine transporter immunolabeling in basal forebrain, striatum, basolateral amygdala, and hippocampus, but had similar levels of acetylcholinesterase and numbers of ChAT+ neurons as Cre- rats. This study suggests that variance in behavior between ChAT::Cre+ and wildtype rats is sex dependent and advances theories that distinct neural circuits and processes regulate sexually divergent fear responses.     

Inactivation of p53 Is Sufficient to Induce Development of Pulmonary Hypertension in Rats

Objective

Pulmonary artery smooth muscle cells (PA-SMCs) in pulmonary arterial hypertension (PAH) show similarities to cancer cells. Due to the growth-suppressive and pro-apoptotic effects of p53 and its inactivation in cancer, we hypothesized that the p53 pathway could be altered in PAH. We therefore explored the involvement of p53 in the monocrotaline (MCT) rat model of pulmonary hypertension (PH) and the pathophysiological consequences of p53 inactivation in response to animal treatment with pifithrin-α (PFT, an inhibitor of p53 activity).

Methods and Results

PH development was assessed by pulmonary arterial pressure, right ventricular hypertrophy and arterial wall thickness. The effect of MCT and PFT on lung p53 pathway expression was evaluated by western blot. Fourteen days of daily PFT treatment (2.2 mg/kg/day), similar to a single injection of MCT (60 mg/kg), induced PH and aggravated MCT-induced PH. In the first week after MCT administration and prior to PH development, p53, p21 and MDM2 protein levels were significantly reduced; whereas PFT administration effectively altered the protein level of p53 targets. Anti-apoptotic and pro-proliferative effects of PFT were revealed by TUNEL and MTT assays on cultured human PA-SMCs treated with 50 μM PFT.

Conclusions

Pharmacological inactivation of p53 is sufficient to induce PH with a chronic treatment by PFT, an effect related to its anti-apoptotic and pro-proliferative properties. The p53 pathway was down-regulated during the first week in the rat MCT model. These in vivo experiments implicate the p53 pathway at the initiation stages of PH pathogenesis.     

The natural antioxidant rosmarinic acid spontaneously penetrates membranes to inhibit lipid peroxidation in situ

Exogenous molecules from dietary sources such as polyphenols are very efficient in preventing the alteration of lipid membranes by oxidative stress. Among the polyphenols, we have chosen to study rosmarinic acid (RA). We investigated the efficiency of RA in preventing lipid peroxidation and in interacting with lipids. We used liposomes of 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLPC) to show that RA was an efficient antioxidant. By HPLC, we determined that the maximum amount of RA associated with the lipids was ~1 mol%. Moreover, by using Langmuir monolayers, we evidenced that cholesterol decreases the penetration of RA. The investigation of transferred lipid/RA monolayers by atomic force microscopy revealed that 1 mol% of RA in the membrane was not sufficient to alter the membrane structure at the nanoscale. By fluorescence, we observed no significant modification of membrane permeability and fluidity caused by the interaction with RA. We also deduced that RA molecules were mainly located among the polar headgroups of the lipids. Finally, we prepared DLPC/RA vesicles to evidence for the first time that up to 1 mol% of RA inserts spontaneously in the membrane, which is high enough to fully prevent lipid peroxidation without any noticeable alteration of the membrane structure due to RA insertion.     

Influence of age on cardiac baroreflex function during dynamic exercise in humans

We investigated the influence of aging on cardiac baroreflex function during dynamic exercise in seven young (22 +/- 1 yr) and eight older middle-aged (59 +/- 2 yr) healthy subjects. Carotid-cardiac baroreflex function was assessed at rest and during moderate-intensity steady-state cycling performed at 50% heart rate reserve (HRR). Five-second pulses of neck pressure and neck suction from +40 to -80 Torr were applied to determine the operating point gain (G(OP)) and maximal gain (G(MAX)) of the full carotid-cardiac baroreflex function curve and examine baroreflex resetting during exercise. At rest, mean arterial pressure (MAP) and heart rate were similar between the younger and older subjects. In contrast, the resting G(OP) and G(MAX) were significantly lower in the older subjects. The increase in MAP from rest to exercise was greater in the older subjects (Delta +20 +/- 2 older vs. Delta +6 +/- 3 younger mmHg; P < 0.001). However, the G(OP) was similar in both groups during exercise because of a reduction in the younger subjects. In contrast, G(MAX) was unchanged from rest and therefore remained lower in older subjects (-0.19 +/- 0.05 older vs. -0.42 +/- 0.05 younger beats.min(-1).mmHg(-1); 50% HRR; P < 0.001). Furthermore, exercise resulted in an upward and rightward resetting of the cardiac baroreflex function curve in both groups. Collectively, these findings suggest that the cardiac baroreflex function curve appropriately resets during exercise in older subjects but operates at a reduced G(MAX) primarily because of age-related reductions in carotid-cardiac control manifest at rest.     

Linear Growth and Final Height Characteristics in Adolescent Females with Anorexia Nervosa

Objective

Growth retardation is an established complication of anorexia nervosa (AN). However, findings concerning final height of AN patients are inconsistent. The aim of this study was to assess these phenomena in female adolescent inpatients with AN.

Methods

We retrospectively studied all 211 female adolescent AN patients hospitalized in an inpatient eating disorders department from 1/1/1987 to 31/12/99. Height and weight were assessed at admission and thereafter routinely during hospitalization and follow-up. Final height was measured in 69 patients 2–10 years after discharge. Pre-morbid height data was available in 29 patients.

Results

Patients’ height standard deviation scores (SDS) on admission (−0.285±1.0) and discharge (−0.271±1.02) were significantly (p<0.001) lower than expected in normal adolescents. Patients admitted at age ≤13 years, or less than 1 year after menarche, were more severely growth-impaired than patients admitted at an older age, (p = 0.03). Final height SDS, available for 69 patients, was −0.258±1.04, significantly lower than expected in a normal population (p = 0.04), and was more severely compromised in patients who were admitted less than 1 year from their menarche. In a subgroup of 29 patients with complete growth data (pre-morbid, admission, discharge, and final adult height), the pre-morbid height SDS was not significantly different from the expected (−0.11±1.1), whereas heights at the other time points were significantly (p = 0.001) lower (−0.56±1.2, −0.52±1.2, and −0.6±1.2, respectively).

Conclusions

Our findings suggest that whereas the premorbid height of female adolescent AN patients is normal, linear growth retardation is a prominent feature of their illness. Weight restoration is associated with catch-up growth, but complete catch-up is often not achieved.     

Regulation of middle cerebral artery blood velocity during dynamic exercise in humans: influence of aging.

Although cerebral autoregulation (CA) appears well maintained during mild to moderate intensity dynamic exercise in young subjects, it is presently unclear how aging influences the regulation of cerebral blood flow during physical activity. Therefore, to address this question, middle cerebral artery blood velocity (MCAV), mean arterial pressure (MAP), and the partial pressure of arterial carbon dioxide (Pa(CO(2))) were assessed at rest and during steady-state cycling at 30% and 50% heart rate reserve (HRR) in 9 young (24 +/- 3 yr; mean +/- SD) and 10 older middle-aged (57 +/- 7 yr) subjects. Transfer function analysis between changes in MAP and mean MCAV (MCAV(mean)) in the low-frequency (LF) range were used to assess dynamic CA. No age-group differences were found in Pa(CO(2)) at rest or during cycling. Exercise-induced increases in MAP were greater in older subjects, while changes in MCAV(mean) were similar between groups. The cerebral vascular conductance index (MCAV(mean)/MAP) was not different at rest (young 0.66 +/- 0.04 cm x s(-1) x mmHg(-1) vs. older 0.67 +/- 0.03 cm x s(-1) x mmHg(-1); mean +/- SE) or during 30% HRR cycling between groups but was reduced in older subjects during 50% HRR cycling (young 0.67 +/- 0.03 cm x s(-1) x mmHg(-1) vs. older 0.56 +/- 0.02 cm x s(-1) x mmHg(-1); P < 0.05). LF transfer function gain and phase between MAP and MCAV(mean) was not different between groups at rest (LF gain: young 0.95 +/- 0.05 cm x s(-1) x mmHg(-1) vs. older 0.88 +/- 0.06 cm x s(-1) x mmHg(-1); P > 0.05) or during exercise (LF gain: young 0.80 +/- 0.05 cm x s(-1) x mmHg(-1) vs. older 0.72 +/- 0.07 cm x s(-1) x mmHg(-1) at 50% HRR; P > 0.05). We conclude that despite greater increases in MAP, the regulation of MCAV(mean) is well maintained during dynamic exercise in healthy older middle-aged subjects.     

Novel Role for Matricellular Proteins in the Regulation of Islet β Cell Survival: THE EFFECT OF SPARC ON SURVIVAL,PROLIFERATION, AND SIGNALING*

Understanding the mechanisms regulating islet growth and survival is critical for developing novel approaches to increasing or sustaining β cell mass in both type 1 and type 2 diabetes patients. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that is important for the regulation of cell growth and adhesion. Increased SPARC can be detected in the serum of type 2 diabetes patients. The aim of this study was to investigate the role of SPARC in the regulation of β cell growth and survival. We show using immunohistochemistry that SPARC is expressed by stromal cells within islets and can be detected in primary mouse islets by Western blot. SPARC is secreted at high levels by pancreatic stellate cells and is regulated by metabolic parameters in these cells, but SPARC expression was not detectable in β cells. In islets, SPARC expression is highest in young mice, and is also elevated in the islets of non-obese diabetic (NOD) mice compared with controls. Purified SPARC inhibits growth factor-induced signaling in both INS-1 β cells and primary mouse islets, and inhibits IGF-1-induced proliferation of INS-1 β cells. Similarly, exogenous SPARC prevents IGF-1-induced survival of primary mouse islet cells. This study identifies the stromal-derived matricellular protein SPARC as a novel regulator of islet survival and β cell growth.