Intracranial lipoma of the quadrigeminal region associated with complex partial seizures

A 7-year-old Japanese boy with an intracranial lipoma of the quadrigeminal region and complex partial seizures is reported. Among 28 published patients with lipoma originating in the quadrigeminal plate and ambient cistern, 6 suffered from seizures and 3 were mentally retarded. Our patient's seizures were controlled with carbamazepine.     

Oral reconstruction using the peroneal flap

1. Recent studies have indicated that nitric oxide (NO) production in the kidney contributes to the regulation of renal haemodynamics and excretory function. Inhibition of nitric oxide synthase (NOS) reduces renal blood flow by approximately 25% and markedly reduces sodium excretion without reductions in filtered load. In particular, inhibition of NO synthesis markedly suppresses the slope of the arterial pressure-mediated response in sodium excretion. 2. Further studies have shown that constant intrarenal infusion of a NO donor in dogs treated with a NOS inhibitor produced diuretic and natriuretic responses but failed to restore the slope of the pressure-induced natriuretic response. These data indicate that an alteration in intrarenal NO activity, rather than the simple presence of NO during changes in arterial pressure is required for full expression of pressure natriuretic responses. 3. In support of the hypothesis that NO is involved in the mediation of pressure natriuresis, we also recently demonstrated a direct relationship between changes in arterial pressure and urinary excretion rate of sodium as well as nitrate and nitrite (a marker for endogenous NO activity) in the presence of efficient autoregulation of cortical and medullary blood flow. 4. The direct inhibitory actions of NO on tubular sodium reabsorption have also been observed in cultured tubular cells as well as isolated, perfused cortical collecting duct segments. 5. Thus, the collective data suggest that acute changes in arterial pressure induce changes in intrarenal NO production, which may directly alter tubular reabsorptive function to manifest the phenomenon of pressure natriuresis.     

Molecular cloning and functional expression of a water-soluble chlorophyll protein, a putative carrier of chlorophyll molecules in cauliflower

A cDNA for a water-soluble chlorophyll (Chl) protein (WSCP) from cauliflower (Brassica oleracea L. var botrys) was cloned and sequenced. The cDNA contained an open reading frame encoding 19 residues for a signal peptide and 199 residues for the mature form of WSCP. The sequence showed extensive homology to drought-stress-related, 22-kDa proteins in some Brassicaceae plants. Functional WSCP was expressed in Escherichia coli as a fusion protein with a maltose-binding protein (MBP). When the recombinant MBP-WSCP was incubated with thylakoid membranes, the MBP-WSCP removed Chls from these membranes. During this process, the monomer of the apo-MBP-WSCP successfully bound Chls and was converted into tetrameric holo-MBP-WSCP. The reconstituted MBP-WSCP exhibited absorption and fluorescent spectra identical to those of the native WSCP purified from cauliflower leaves. The Chl a/b ratio in native WSCP indicates a high content of Chl a, which was mainly due to the higher affinity of MBP-WSCP for Chl a. WSCP is the first example of a hydrophilic protein that can transfer Chls from thylakoid hydrophobic proteins. Possible functions of WSCP are discussed.     

Perfusion and blood-pool scintigraphy in the evaluation of head and neck hemangiomas

We investigated the sensitivity and specificity of perfusion and blood-pool scintigraphy in the detection of head and neck hemangiomas and evaluated their histopathologic types. METHODS: Perfusion and blood-pool scintigraphy with 99mTc-red blood cells (RBCs) or 99mTc-human serum albumin combined with DTPA (HSA-D) were used to evaluate 51 head and neck lesions clinically suspected of being hemangiomas in 48 patients. Thirty-three of the 51 lesions were subsequently histologically confirmed to be hemangiomas, whereas the remaining 18 were histologically diagnosed as other lesions. RESULTS: Perfusion and blood-pool scintigraphy correctly diagnosed 30 of 33 hemangiomas as being hemangiomas but could not detect the remaining 3 hemangiomas. Perfusion and blood-pool scintigraphy correctly diagnosed 12 of 18 lesions as nonhemangiomas, but the remaining 6 lesions were misdiagnosed as hemangiomas. Thus, the sensitivity for detecting hemangiomas was 91%, with a specificity and accuracy of 67% and 82%, respectively. Twenty-five (89%) of 28 cavernous or venous hemangiomas demonstrated normal activity on the perfusion images and increased activity on the delayed blood-pool images, whereas the remaining 3 (11%) showed normal activity on both perfusion and blood-pool images. Finally, 5 of 5 (100%) capillary or recemose hemangiomas showed increased activity on the perfusion and blood-pool images. CONCLUSION: Perfusion and blood-pool scintigraphy demonstrated sufficiently high sensitivity but relatively low specificity for detecting head and neck hemangiomas. Additionally, perfusion and blood-pool scintigraphy can clearly differentiate between cavernous and venous hemangiomas and capillary and recemose hemangiomas and are extremely useful for the detection and evaluation of head and neck hemangiomas.     

Damper windings phenomena of synchronous machines during systemoscillations

The performances of the damper windings of a synchronous machine (generator) under the oscillatory conditions of the power system to which it is connected, are investigated both experimentally and analytically in this paper. Air-gap fluxes and induced voltages and currents of the damper windings under the oscillatory system conditions, when the machine is equipped both with and without damper windings, are measured and analyzed. Fourier analyses are used to examine the harmonic components appearing in the air-gap flux density distributions and the damper induced voltages and currents to clarify the phenomena caused by the damper as well as the effect of the damper upon power system performances     

Effects of antiendothelin treatment on the early hemodynamic changes in hyperdynamic endotoxemia

We have performed a series of experiments to study the effects of a newly developed antisense homology box-derived endothelin (ET) antagonist peptide (ETR-P1/fl) on the early hemodynamic changes in a hyperdynamic endotoxemic dog model. Mean arterial pressure (MAP), cardiac output (CO) and myocardial contractility (MC) were measured in closed-chest animals. Plasma levels of ET-1,2 were determined by radioimmunassay. A hyperdynamic circulatory response was elicited with a 2-hour infusion of 5.3 micrograms/kg of E. coli endotoxin (ETX). Control and ETX-treated animals received an infusion of ETR-P1/fl (0.1 mg/kg) i.v. ETX treatment decreased MAP and MC, increased initially CO, and a long lasting elevation in the plasma ET level was observed. In ETX-treated animals the administration of ETR-P1/fl significantly prolonged the increase in CO and inhibited the depression of MC. Our results suggest that treatment with the ET antagonist ETR-P1/fl may be advantageous in the early phase of endotoxemia.     

Throughput analysis of DS/SSMA unslotted ALOHA system with fixedpacket length

Throughput analysis of direct-sequence spread spectrum multiple access (DS/SSMA) unslotted ALOHA with fixed packet length is presented. As the levels of multi-user interference fluctuate during the packet transmission, we calculate the packet error probability and the throughput by considering not only the number of overlapped packets but also the amount of time overlap. On the assumption that packet generation is Poisson, the system can be thought as the queueing system M/D/∞. With Gaussian approximation of multi-user interference, we obtain the throughput as the function of the number of chips in a bit, the packet length, and the offered load of the system. We also analyze the channel load sensing protocol (CLSP), and obtain the optimum threshold of CLSP