Interleukin-1beta abrogates long-term depression of hippocampal CA1 synaptic transmission

Although interleukin-1beta (IL-1beta) is well known to modulate synaptic transmission and plasticity of the hippocampus, no study has yet evaluated how this cytokine affects long-term depression (LTD), one of the major forms of hippocampal synaptic plasticity. Here we report that at Schaffer collateral-CA1 synapses, bath application of IL-1beta induces a long-lasting decrease in synaptic strength in intact slices, but not in disinhibited slices in the presence of bicuculline, a gamma-aminobutyric acid receptor antagonist. The IL-1beta-induced synaptic depression efficiently foreclosed the subsequent induction of LTD in response to a 1-Hz tetanus and, conversely, it was also prevented by preexisting LTD. These results suggest that IL-1beta-induced, persistent depression of synaptic efficacy is required for GABAergic activation and shares, at least in part, a common cellular mechanism for LTD.     

Information flow related to visual search assessed using magnetoencephalography

The sequence of neural activation during a visual search task was investigated using magnetoencephalography and the source locations for the activations were analyzed using a single-dipole algorithm. Five components (M1-5) were detected at mean latencies of 110, 146, 196, 250 and 333 ms in both of two different stimulus conditions; a target popped out in one stimulus condition (pop-out), while it did not in the other condition (non-pop-out). Statistical analysis showed that the M3 amplitude was larger and the M5 latency was shorter in the pop-out condition than in the non-pop-out condition, while there was no difference in the other components between the conditions. Neural sources were localized in the calcarine sulcus (M1) and the posterior fusiform gyrus (M2) of the hemisphere contralateral to the stimuli, the intraparietal sulcus and the posterior superior temporal sulcus (M3) in either of the hemispheres, and the calcarine sulcus (M4) of the same hemisphere in which the early processing (M1 and M2) occurred. The criteria for source localization were not satisfied for M5. The results suggest that the processing for pop-out and non-pop-out stimuli share a common mechanism; after early feature processing in the occipital cortex (M1 and M2), visual information is processed in the parietal and temporal regions (M3) and then some of this information is fed back to the occipital cortex (M4).     

Total parenteral nutrition entrains the central and peripheral circadian clocks

The administration schedule of total parenteral nutrition (TPN) ignores the human physiological food-intake rhythm. This study examined the effects of TPN on the central and peripheral circadian clocks. Male Wistar rats were divided into a control group, a nocturnal-TPN group, and a diurnal-TPN group. On the seventh day after TPN administration, expression of rat period2 (rPer2) and D-site binding protein (rDBP) mRNA were measured in the suprachiasmatic nucleus (SCN) and liver. While rPer2 and rDBP mRNA expression of the nocturnal-TPN rats showed similar oscillation patterns to those in the free-fed control rats both in the SCN and liver, they were shifted significantly in the diurnal-TPN rats. This phase shift occurred as early as day 1. TPN, which ignores physiological food-intake rhythms, alters the rhythm of the central and peripheral clocks.     

fMRI study of recognition of facial expressions in high-functioning autistic patients

Autistic disorder is associated with deficits in social function. The disorder may be related to dysfunction in the brain regions that are involved in the process of recognising facial expressions of other persons. Using fMRI, we investigated whether autistic patients with relatively high IQ would have different brain activation on the tasks of recognition of facial expressions (i.e. faces expressing disgust, fear, and happiness) compared with normal control subjects. In disgust and fear recognition tasks, there were different patterns of brain activation in the cortico-limbic neural circuits qbetween autistic and normal groups. Patients with autistic disorder may have difficulty in grasping facially expressed qemotions in others, and thereby cannot manipulate the interpersonally derived information.     

Combination therapy with interferon alpha and beta to chronic hepatitis C

To increase the sustained response (SR) rate in chronic hepatitis C (CHC), we tried a combination therapy with interferon (IFN) alpha and beta. Fifty patients were grouped into 4 groups: group 1H (n=9), HCV serotype 1 and high HCV-RNA titer (over 6 log copies/ml); group 1L (n=11), HCV serotype 1 and low HCV-RNA titer (less than 6 log copies/ml); group 2H (n=23), HCV serotype 2 and high HCV-RNA titer; group 2L (n=7), HCV serotype 2 and low HCV-RNA titer. They were given a total dose of 768 MIU which included natural IFN beta (6 MIU) once daily for 28 consecutive days and then natural IFNalpha (10 MIU) three times a week for 20 weeks. Forty-nine patients with CHC receiving IFN alpha at total dose of 480 MIU served as single therapy group. In combination group, SR rate was achieved in 62%, 44% in 1H, 45% in 1L, 70% in 2H, and 86% in 2L, respectively. In single group, SR rate was achieved in 45, 14, 58, 60, and 82%, respectively. There was no significant difference for SR rate between combination group and single group. However, in patients with HCV-RNA titer between 6-7 log copies/ml of 1H group, SR rate in combination group (67%, 4/6) was significantly higher than that of single group (18%, 3/17) (p<0.05). These data suggest the usefulness of combination therapy with IFN alpha and beta in CHC with serotype 1 having moderately high HCV-RNA titer.     

Peripheral odontogenic keratocyst: a report of 2 cases

BACKGROUND: Occurrence of a gingival cyst in adults that exhibits the histopathologic hallmarks of an odontogenic keratocyst (OKC) is rare. METHODS: Two cases of primary soft tissue OKC in an adult female are described. Both presented as an asymptomatic small nodule on the buccal gingiva of the anterior mandible. RESULTS: After simple excision, no recurrence was observed. CONCLUSIONS: All available data indicate that, irrespective of the nomenclature, peripheral OKC should be included under the histopathological spectrum of gingival cysts in the adult.     

Tertiapin, a selective IKACh blocker, terminates atrial fibrillation with selective atrial effective refractory period prolongation.

It is well known that vagal nerve tone plays a crucial role in atrial fibrillation (AF). Acetylcholine-activated potassium current (IKACh) mediates much of the cardiac response to vagal nerve stimulation (VNS), but the contribution of IKACh to AF remains unknown. We investigated the role of the IKACh channel in canine AF models using tertiapin, a selective IKACh blocker. Tertiapin (4-41 nmol kg(-1), i.v.) terminated AF in the canine VNS-induced and aconitine-induced AF models. The muscarinic M-receptor antagonist AF-DX-116 terminated AF in these models, but the adenosine receptor antagonist DPCPX had no effect. Thus it is likely that IKACh activation via the M-receptor has a crucial role in both models. Tertiapin (12 nmol kg(-1), i.v.) preferentially prolonged the atrial effective refractory period (ERP) but not the ventricular ERP under the VNS condition. This peptide (4-41 nmol kg(-1), i.v.) did not affect PQ, QRS and corrected QT intervals in isoflurane-anaesthetised dogs. These results suggest that a selective IKACh blocker is effective in canine AF models without affecting ventricular repolarisation, and might be useful for the treatment of patients with AF.     

Electro-acupuncture stimulation to muscle afferents in anesthetized rats modulates the blood flow to the knee joint through autonomic reflexes and nitric oxide

Recent reports have focused on the mechanisms of the action of electro-acupuncture stimulation (EAS) in the regulation of blood flow to different tissues. In the knee joint, blood flow is known to be modulated mainly by sympathetic postganglionic fibers, but recently the release or induction of nitric oxide (NO) synthesis in response to electrical stimulation has also been suggested. Therefore, a direct observation of the microcirculation is needed to further understand the mechanism by which blood flow is regulated by somatic afferent stimulation. In the present study, the effects of EAS to the vastus medialis muscle on systemic hemodynamics and the knee joint microcirculation were observed in vivo using a real-time confocal laser-scanning microscope system (CLMS). Electrical stimulation (5 mA, 0.5 ms, 5 Hz) was applied for 30 min using a pair of acupuncture needles introduced into the vastus medialis muscle. To clarify a plausible involvement of NO in the responses to EAS, the stimulus was applied either in the presence or absence of N(omega)-nitro-L-arginine methyl ester (L-NAME). Stimulation to either the muscle or the skin of the thigh after blockade of neuromuscular transmission was performed to determine the involvement of muscle contraction during EAS treatment. The changes in mean arterial pressure (MAP) and diameter of the arterioles supplying the knee joint were monitored continuously until 60 min poststimulus. Significant and persistent increases in arteriolar diameter by 26 +/- 6% and MAP by 17 +/- 2%, respectively, were observed after EAS to the muscle. Electro-acupuncture to the vastus medialis in the presence of L-NAME produced a strong decrease in diameter of the knee joint arterioles by -38 +/- 14% under the baseline with a simultaneous increase of 35 +/- 5% in MAP. EAS to the skin did not produce changes in arteriolar diameter while a slight increase in MAP by 12 +/- 6% over the baseline occurred after the stimulus. EAS to the muscle after neuromuscular blockade did not produce significant changes in diameter, while an increase in MAP by 24 +/- 8% was still observed, which facts suggest that the muscle contraction is required to produce vasodilatation. These responses suggest that a dynamic balance between the autonomic nervous system and the release of NO is the primary mechanism mediating the EAS effects on knee joint microcirculation.     

An infant case of bilateral small kidneys with both proximal and distal tubular dysfunction

Abstract A male infant with bilateral small kidneys associated with both proximal and distal tubular dysfunction, who showed chronic renal failure soon after birth, is reported. He was also noted to have both proximal and distal type of renal tubular acidosis. The small kidneys were thought to be due to renal hypodysplasia associated with bilateral severe vesicoureteral reflux, by radiological findings. An alkalization therapy with chemo-prophylaxis seemed to be of benefit in slowing the progression of renal failure in this case.