Treating a novel plasticity defect rescues episodic memory in Fragile X model mice.

Episodic memory, a fundamental component of human cognition, is significantly impaired in autism. We believe we report the first evidence for this problem in the Fmr1-knockout (KO) mouse model of Fragile X syndrome and describe potentially treatable underlying causes. The hippocampus is critical for the formation and use of episodes, with semantic (cue identity) information relayed to the structure via the lateral perforant path (LPP). The unusual form of synaptic plasticity expressed by the LPP (lppLTP) was profoundly impaired in Fmr1-KOs relative to wild-type mice. Two factors contributed to this defect: (i) reduced GluN1 subunit levels in synaptic NMDA receptors and related currents, and (ii) impaired retrograde synaptic signaling by the endocannabinoid 2-arachidonoylglycerol (2-AG). Studies using a novel serial cue paradigm showed that episodic encoding is dependent on both the LPP and the endocannabinoid receptor CB1, and is strikingly impaired in Fmr1-KOs. Enhancing 2-AG signaling rescued both lppLTP and learning in the mutants. Thus, two consequences of the Fragile-X mutation converge on plasticity at one site in hippocampus to prevent encoding of a basic element of cognitive memory. Collectively, the results suggest a clinically plausible approach to treatment.

Adolescent cannabinoid exposure effects on natural reward seeking and learning in rats.

RATIONALE: Adolescence is characterized by endocannabinoid (ECB)-dependent refinement of neural circuits underlying emotion, learning, and motivation. As a result, adolescent cannabinoid receptor stimulation (ACRS) with phytocannabinoids or synthetic agonists like "Spice" cause robust and persistent changes in both behavior and circuit architecture in rodents, including in reward-related regions like medial prefrontal cortex and nucleus accumbens (NAc). OBJECTIVES AND METHODS: Here, we examine persistent effects of ACRS with the cannabinoid receptor 1/2 specific agonist WIN55-212,2 (WIN; 1.2 mg/kg/day, postnatal day (PD) 30-43), on natural reward-seeking behaviors and ECB system function in adult male Long Evans rats (PD 60+). RESULTS: WIN ACRS increased palatable food intake, and altered attribution of incentive salience to food cues in a sign-/goal-tracking paradigm. ACRS also blunted hunger-induced sucrose intake, and resulted in increased anandamide and oleoylethanolamide levels in NAc after acute food restriction not seen in controls. ACRS did not affect food neophobia or locomotor response to a novel environment, but did increase preference for exploring a novel environment. CONCLUSIONS: These results demonstrate that ACRS causes long-term increases in natural reward-seeking behaviors and ECB system function that persist into adulthood, potentially increasing liability to excessive natural reward seeking later in life.

Use of IgY antibody to recombinant avian reovirus σC protein in the virus diagnostics.

Avian reovirus (ARV) is an important agent of several diseases causing considerable losses in poultry farming. An outer capsid protein (σC) of ARV, is known as a virus-cell attachment protein essential for virus infectivity. In this study, the σC gene of ARV was cloned and expressed in Escherichia coli. The expressed recombinant protein was used as immunogen for raising a specific IgY antibody in laying hens. At 14 weeks post immunization, the antibody titers in serum and egg yolk reached 302,000 and 355,000, respectively. The IgY antibody was capable to neutralize ARV in BHK-21 cells and it strongly reacted in ELISA with ARV but not with heterologous viruses. The IgY antibody detected ARV in field samples of infected animal tissues in dot blot assay. These results suggest that an efficient, economic and rapid diagnostics of ARV can be performed routinely using the IgY antibody against a recombinant ARV σC protein.

Inhibitory effect of glycolic acid on ultraviolet-induced skin tumorigenesis in SKH-1 hairless mice and its mechanism of action.

Glycolic acid, an alpha-hydroxy acid derived from fruit and milk sugars, has been used commonly as a cosmetic ingredient since it was discovered to have photoprotective and anti-inflammatory effects and antioxidant effects on ultraviolet (UV)B-irradiated skin. Little is known, however, about the functional role of glycolic acid on UV-induced skin tumorigenesis. In the present study, we examined the effect of glycolic acid on UV (UVA + UVB)-induced skin tumorigenesis and assessed several significant contributing factors in SKH-1 hairless mice. Inbred hairless female mice (15 animals/group) were irradiated for 5 d/wk at a total dose of 74.85 J/cm(2) UVA and 2.44 J/cm(2) UVB for 22 wk. Glycolic acid was applied topically twice a week at a dose of 8 mg/cm(2) immediately after UV irradiation. Glycolic acid reduced UV-induced skin tumor development. The protective effect of glycolic acid was a 20% reduction of skin tumor incidence, a 55% reduction of tumor multiplicity (average number of tumors/mouse), and a 47% decrease in the number of large tumors (larger than 2 mm). Glycolic acid also delayed the first appearance of tumor formation by about 3 wk. The inhibitory effect of glycolic acid on UV-induced tumor development was accompanied by decreased expression of the following UV-induced cell-cycle regulatory proteins: proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin E, and the associated subunits cyclin-dependent kinase 2 (cdk2) and cdk4. In addition, the expression of p38 kinase, jun N-terminal kinase (JNK), and mitogen-activated protein kinase kinase (MEK) also was lower in UV + glycolic acid-treated skin compared with expression in UV-irradiated skin. Moreover, transcription factors activator protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB) activation was significantly lower in UV + glycolic acid-treated skin compared with activation in UV-irradiated skin. These results show that glycolic acid reduced UV-induced skin tumor development. The decreased expression of the cell-cycle regulatory proteins PCNA, cyclin D1, cyclin E, cdk2, and cdk4 and the signal mediators JNK, p38 kinase, and MEK may play a significant role in the inhibitory effect of glycolic acid on UV-induced skin tumor development. In addition, the inhibition of activation of transcription factors AP-1 and NF-kappaB could contribute significantly to the inhibitory effect of glycolic acid.

Identification of multiple forms of membrane-associated neutral sphingomyelinase in bovine brain.

Many different stimuli such as bioactive agents and environmental stresses are known to cause the activation of sphingomyelinase (SMase), which hydrolyzes sphingomyelin to generate ceramide as a second messenger playing a key role in differentiation and apoptosis in various cell types. Here we identified multiple forms of the membrane-associated neutral SMase (N-mSMase) activity in bovine brain. They could be classified into two groups according to extracting agents: group T-mSMase, extracted with 0.2% Triton X-100, and group S-mSMase, extracted with 0.5 M (NH(4))(2)SO(4). Group T-mSMase: alpha, beta, gamma, and delta, which were extensively purified from 40,000-g pellets of bovine brain homogenates by 3,150-, 5,275-, 1,665-, and 2,556-fold over the membrane extracts, respectively, by sequential use of several column chromatographies. On the other hand, S-mSMase was eluted as two active peaks of S-mSMase epsilon and zeta in a phenyl-5PW hydrophobic HPLC column and further purified by 1,119- and 976-fold over 40,000-g pellets of the homogenates, respectively. These highly purified N-mSMase enzyme preparations migrated as several bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and showed many different features in biochemical properties such as pH dependence, Mg(2+) requirements, and effects of detergents. Taken together, our data strongly suggest that mammalian brain N-mSMase may exist as multiple forms different in both its chromatographic profiles and biochemical properties.

Purification and characterization of a membrane-associated 48-kilodalton phospholipase A(2) in leaves of broad bean.

Several lines of evidence indicate that phospholipase A(2) (PLA(2)) plays a crucial role in plant cellular responses through production of linolenic acid, the precursor of jasmonic acid, from membrane phospholipids. Here we report the purification and characterization of a 48-kD PLA(2) from the membrane fractions of leaves of broad bean (Vicia faba). The plant PLA(2) was purified to near homogeneity by sequential column chromatographies from the membrane extracts. The purified 48-kD protein migrated as a single band on a SDS-PAGE gel and its density correlated with the PLA(2) activity. It was further confirmed that this 48-kD protein is the PLA(2) enzyme based on immunoprecipitating the activity with a monoclonal antibody against it and purifying the enzyme to homogeneity with the antibody affinity column. The purified plant PLA(2) preferred 2-linolenoyl-sn-glycerol-3-phosphocholine (GPC) to 2-linoleoyl-GPC, 2-palmitoyl-GPC and 2-arachidonyl-GPC as substrates with a pH optimum at pH 7.0 to 8.0. The plant PLA(2) was activated by calmodulin and inhibited by pretreatment of 5,8,11, 14-eicosatetraynoic acid known as an inhibitor of mammalian PLA(2)s. The enzyme was characterized as a Ca(2+)-independent PLA(2) different from mammalian PLA(2)s. This membrane-associated and Ca(2+)-independent PLA(2) is suggested to play an important role in the release of linolenic acid, the precursor of jasmonic acid, through a signal transduction pathway.

Effect of phenylpropanolamine hydrochloride on blood pressure in Korean patients with hypertension controlled by hydrochlorothiazide.

The effect of 10 oral doses of phenylpropanolamine hydrochloride 25 mg four times a day on blood pressure and heart rate in Korean patients with hypertension controlled by hydrochlorothiazide was studied. A randomized, placebo-controlled, crossover, double-blind study design was used. Twenty Korean patients with mild hypertension controlled by hydrochlorothiazide were recruited from an ambulatory-care clinic. Blood pressure and heart rate were measured in triplicate before treatment, after a five-day washout period between phases of treatment, and two hours after the last dose in each phase of treatment. Eighteen patients completed both phases of treatment, and one patient completed only the placebo phase. Mean baseline values for systolic and diastolic blood pressures and heart rate before the placebo phase did not significantly differ from mean baseline values before the phenylpropanolamine phase. Comparison of mean baseline values for systolic and diastolic blood pressures and heart rate with mean after-treatment values showed no clinically relevant or statistically significant changes for the 19 patients who completed the placebo phase or the 18 patients who completed the phenylpropanolamine phase. There was no significant difference between the mean change in systolic blood pressure, diastolic blood pressure, or heart rate when the phenylpropanolamine phase was compared with the placebo phase. Phenylpropanolamine hydrochloride 25 mg p.o. four times a day (total, 10 doses) given to Korean patients with hypertension controlled by hydrochlorothiazide did not affect blood pressure or heart rate according to single-point outcome measurements.

A case of pulmonary cysticercosis.

Cysticercosis, which has a worldwide distribution is found in man, who is usually infected by eating inadequately cooked pork or other contaminated food. Cysticercosis develops most commonly in the muscles and brain. Pulmonary involvement is very rare and also difficult to recognize because pulmonary lesions caused by the presence of cysticerci are difficult to discern from pulmonary infiltrates, because other parasitic infestations or tuberculosis, as well as metastatic lesions, produce similar chest X-ray findings and similar clinical symptoms. We experienced a case of pulmonary cysticercosis confirmed at Gyeongsang National University Hospital by means of an open lung biopsy and treated successfully with praziquantel (50 mg/kg per day for 15 days). This case seems to indicate that pulmonary cysticercosis should be considered as a diagnostic possibility in patients with nodular infiltrates in the lungs, especially in endemic areas, until such infiltrates are otherwise explained.