Excitation of NH Stretching Modes in Aromatic Molecules: o-Toluidine and α-Methylbenzylamine

Selectively excited o-toluidine and α-methylbenzylamine have been studied with quasi-classical trajectory procedures to determine the extent and timescales of intramolecular energy flow. The initial excitation is in the stretching mode of the para-CH bond, and its flow is initiated by interaction with an argon atom. Energy flow to the NH stretching mode is the dominant relaxation pathway, and its effectiveness is enhanced strongly by the methyl-NH interaction. Energy flow characteristics in both molecules are similar, but the flow is more effective in o-toluidine than in α-methylbenzylamine because the methyl group bonded to the benzene ring exerts stronger perturbation on the energy-flow pathway than the group bonded to the side chain. The relaxation of the initially excited CH completes on a timescale of several picoseconds, but the main part of energy flow to the NH occurs on a subpicosecond scale. In o-toluidine, carbon-carbon overtone modes lead to ring-CC bonds gaining and transporting more energy than high-frequency CH bonds, but they all gain far less energy than the NH stretching mode.

Influence of a Methyl Group on the Unidirectional Flow of Vibrational Energy in an Adenine-Thymine Base Pair

The role of a methyl group in intramolecular vibrational energy redistribution (IVR) of the hydrogen-bonded adenine-thymine base pair has been studied using classical dynamics procedures. Energy transferred to the doorway bond thymine-NH from the vibrationally excited H₂O(v) efficiently redistributes among various bonds of the base pair through vibration-to-vibration coupling, depositing a large fraction of the available energy in the terminal bond adenine-NH. On the other hand, the extent of energy flow in the reverse direction from the excited adenine-NH to thymine-NH is insignificant, indicating IVR in adenine-thymine resulting from the intermolecular interaction with a vibrationally excited H₂O molecule, is direction-specific. The unidirectional flow is due to the coupling of stretch-torsion vibrations of a methyl group with conjugated bonds on the thymine ring, when the methyl rotor is present and is adjacent to the vibrationally excited thymine-NH. The insignificance of energy flow from the terminal-to-terminal bond in the reverse direction is attributed to the absence of a methyl group on the adenine moiety, even though the molecule has many CC and CN bonds coupled to their neighbors.

Utility of specific amino acid ratios in screening for pyruvate dehydrogenase complex deficiencies and other mitochondrial disorders associated with congenital lactic acidosis and newborn screening prospects

Pyruvate dehydrogenase complex deficiencies (PDCDs) and other mitochondrial disorders (MtDs) can (a) result in congenital lactic acidosis with elevations of blood alanine (Ala) and proline (Pro), (b) lead to decreased ATP production, and (c) result in high morbidity and mortality. With ~140,000 live births annually in Ohio and ~1 in 9,000 overall prevalence of MtDs, we estimate 2 to 3 newborns will have PDCD and 13 to 14 others likely will have another MtD annually. We compared the sensitivities of plasma amino acids (AA) Alanine (Ala), Alanine:Leucine (Ala:Leu), Alanine:Lysine and the combination of Ala:Leu and Proline:Leucine (Pro:Leu), in subjects with known primary-specific PDCD due to PDHA1 and PDHB mutations vs controls. Furthermore, in collaboration with the Ohio newborn screening (NBS) laboratory, we determined Ala and Pro concentrations in dried blood spot (DBS) specimens using existing NBS analytic approaches and evaluated Ala:Leu and Pro:Leu ratios from DBS specimens of 123,414 Ohio newborns in a 12-month period. We used the combined Ala:Leu ≥4.0 and Pro:Leu ≥3.0 ratio criterion from both DBS and plasma specimens as a screening tool in our retrospective review of newborn data. The screening tool applied on DBS and/or plasma (or serum) AA specimens successfully identified three unrelated females with novel de novo PDHA1 mutations, one male with a novel de novo X-linked HSD17B10 mutation, and a female with VARS2 mutations. This work lays the first step for piloting an NBS protocol in Ohio for identifying newborns at high risk for primary-specific PDCD and other MtDs who might benefit from neonatal diagnosis and early institution of known therapy and/or potential novel therapies for such disorders.

A novel null mutation in the pyruvate dehydrogenase phosphatase catalytic subunit gene (PDP1) causing pyruvate dehydrogenase complex deficiency

Congenital lactic acidosis due to pyruvate dehydrogenase phosphatase (PDP) deficiency is very rare. PDP regulates pyruvate dehydrogenase complex (PDC) and defective PDP leads to PDC deficiency. We report a case with functional PDC deficiency with low activated (+dichloroacetate) and inactivated (+fluoride) PDC activities in lymphocytes and fibroblasts, normal activity of other mitochondrial enzymes in fibroblasts, and novel biallelic frameshift mutation in the PDP1 gene, c.575dupT (p.L192FfsX5), with absent PDP1 product in fibroblasts. Unexpectedly, the patient also had low branched-chain 2-ketoacid dehydrogenase (BCKDH) activity in fibroblasts with slight elevation of branched-chain amino acids in plasma and ketoacids in urine but with no pathogenic mutations in the enzymes of BCKDH, which could suggest shared regulatory function of PDC and BCKDH in fibroblasts, potentially in other tissues or cell types as well, but this remains to be determined. The clinical presentation of this patient overlaps that of other patients with primary-specific PDC deficiency, with neonatal/infantile and childhood lactic acidosis, normal lactate to pyruvate ratio, elevated plasma alanine, delayed psychomotor development, epileptic encephalopathy, feeding difficulties, and hypotonia. This patient exhibited marked improvement of overall development following initiation of ketogenic diet at 31 months of age. To the best of our knowledge, this is the fourth case of functional PDC deficiency with a defined mutation in PDP1.

SYNOPSIS

Pyruvate dehydrogenase phosphatase (PDP) regulates pyruvate dehydrogenase complex (PDC) and defective PDP due to PDP1 mutations leads to PDC deficiency and congenital lactic acidosis.

Relaxation of the H2O Overtone Bending Vibration in the Water Dimer···Hydroxyl Radical Complex

The relaxation mechanism of the overtone bending vibration in the collision of the water dimer with the vibrationally excited hydroxyl radical is studied by use of trajectory procedures. The transfer of the OH(v = 1) energy to the dimer stretches is followed by a near-resonant first overtone transition to the donor monomer. Nearly a quarter of the trajectories undergo a complex-mode collision, forming the (H₂O)₂···OH complex bound by a hydrogen bond with the lifetime ranging from a subpicosecond scale to >100 ps. The overtone vibration relaxes to the ground state, transferring approximately half of its energy to the dimer hydrogen-bonding (H₂O···H₂O) and the remaining half to the complex hydrogen-bonding (H₂O)₂···OH, via near-resonant pathways, each consisting of a series of intermolecular low-frequency vibrations.

Energy Transfer to the Hydrogen Bond in the (H2O)2 + H2O Collision

Trajectory procedures are used to study the collision between the vibrationally excited H₂O and the ground-state (H₂O)₂ with particular reference to energy transfer to the hydrogen bond through the inter- and intramolecular pathways. In nearly 98% of the trajectories, energy transfer processes occur on a subpicosecond scale (≤0.7 ps). The H₂O transfers approximately three-quarters of its excitation energy to the OH stretches of the dimer. The first step of the intramolecular pathway in the dimer involves a near-resonant first overtone transition from the OH stretch to the bending mode. The energy transfer probability in the presence of the 1:2 resonance is 0.61 at 300 K. The bending mode then redistributes its energy to low-frequency intermolecular vibrations in a series of small excitation steps, with the pathway which results in the hydrogen-bonding modes gaining most of the available energy. The hydrogen bonding in ∼50% of the trajectories ruptures on vibrational excitation, leaving one quantum in the bend of the monomer fragment. In a small fraction of trajectories, the duration of collision is longer than 1 ps, during which the dimer and H₂O form a short-lived complex through a secondary hydrogen bond, which undergoes large amplitude oscillations.

Abstract P3-01-04: The axillary lymph node to primary breast tumor SUV ratio on FDG-PET/CT in FDG avid primary breast cancers: Could predict the necessity for axillary lymph node dissection

Background: Emerging evidence has indicated that breast cancer patients with a low axillary burden do not benefit from sentinel lymph node biopsy. Thus, to specifically identify more than 3 nodes-positive patients who can proceed directly to axillary lymph node(ALN) dissection, and avoid unnecessary surgical procedures, accurate preoperative detection by radiologic assessment would be anticipated. In this study, we evaluated the usefulness of ALN to primary breast tumor SUV ratio (determined by 18F-FDG PET/CT) and MRI for predicting the need for ALN dissection in breast cancer surgery.

Method: Three hundred sixteen consecutive female patients with primary breast cancer were enrolled in this retrospective study between January 2012 and December 2016. All patients underwent preoperative 18F-FDG PET/CT, MRI, and surgical resection without neoadjuvant chemotherapy.The ALN to primary breast tumor SUV ratios(LN/T ratios) were calculated, and optimal cutoff values were determined by receiver operating characteristic curve analysis for predicting the presence of ≥3 ALN metastasis. The diagnostic performances of 18F-FDG PET/CTLN/T ratio and MRI for the prediction of ≥3 ALN metastasis were determined by sensitivity, specificity, and diagnostic odds ratio(DOR). Subgroup analysis of those for FDG avid cancers were performed.

Result: Of the 316 patients, 36(11.4%) showed involvement of ≥3 ALNs, and 101(32%) had one or more metastatic lymph nodes. The mean SUV of the primary tumor in the 316 patients was 3.9, ranging from 0 to 26.6, while the mean SUV of the ALN was 0.81, ranging from 0 to 21.9. Axillary 18F-FDG uptake was positive in 75(23.7%) patients and optimal criteria of LN/T ratio for detecting the needs for ALN dissection was 0.3 determined by ROC analysis.MRI showed findings of suspicious ALN involvement in 147(46.6%) patients. The sensitivity and specificity of MRI were 0.89 and 0.56, while those of PET/CTLN/T ratio were 0.69 and 0.87. In the receiver operating characteristic(ROC) analysis, the area under the curve(AUC) for MRI and PET/CTLN/T ratio was 0.756 (0.682-0.829, 95% confidence interval), and 0.817(0.733-0.900, 95% confidence interval). Further analysis of the DOR for MRI showed a value of 10.37 and for PET/CTLN/T ratio the DOR was 9.7. But, in a subgroup of patients with FDG-avid primary tumor(FDG above 3.9, n=108), the area under the curve was improved to 0.896 (0.817-0.975, 95% confidence interval) for PET/CTLN/T ratio, while those of MRI was worsened. (0.681, 0.569- 0.793., 95% CI) DOR value of PET/CTLN/T ratio for FDG avid cancers was 25.68 and their sensitivity and specificity were 0.83 and 0.84 each.

Conclusion: In FDG avid primary breast cancer, PET/CTLN/T ratio could predict need for ALN dissection with higher accuracy than MRI. PET/CT has high potential for being used as a non-invasive imaging diagnostic technique identifying ≥3 ALNs metastases.

Citation Format: Kim MK, Shin HK, Shin H-C. The axillary lymph node to primary breast tumor SUV ratio on FDG-PET/CT in FDG avid primary breast cancers: Could predict the necessity for axillary lymph node dissection [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-04.

Enzymatic testing sensitivity, variability and practical diagnostic algorithm for pyruvate dehydrogenase complex (PDC) deficiency

Pyruvate dehydrogenase complex (PDC) deficiency is a major cause of primary lactic acidemia in children. Prompt and correct diagnosis of PDC deficiency and differentiating between specific vs generalized, or secondary deficiencies has important implications for clinical management and therapeutic interventions. Both genetic and enzymatic testing approaches are being used in the diagnosis of PDC deficiency. However, the diagnostic efficacy of such testing approaches for individuals affected with PDC deficiency has not been systematically investigated in this disorder. We sought to evaluate the diagnostic sensitivity and variability of the various PDC enzyme assays in females and males at the Center for Inherited Disorders of Energy Metabolism (CIDEM). CIDEM data were filtered by lactic acidosis and functional PDC deficiency in at least one cell/tissue type (blood lymphocytes, cultured fibroblasts or skeletal muscle) identifying 186 subjects (51% male and 49% female), about half were genetically resolved with 78% of those determined to have a pathogenic PDHA1 mutation. Assaying PDC in cultured fibroblasts in cases where the underlying genetic etiology is PDHA1, was highly sensitive irrespective of gender; 97% (95% confidence interval [CI]: 90%-100%) and 91% (95% CI: 82%-100%) in females and males, respectively. In contrast to the fibroblast-based testing, the lymphocyte- and muscle-based testing were not sensitive (36% [95% CI: 11%-61%, p=0.0003] and 58% [95% CI: 30%-86%, p=0.014], respectively) for identifying known PDC deficient females with pathogenic PDHA1 mutations. In males with a known PDHA1 mutation, the sensitivity of the various cell/tissue assays (75% lymphocyte, 91% fibroblast and 88% muscle) were not statistically different, and the discordance frequency due to the specific cell/tissue used for assaying PDC was 0.15±0.11. Based on this data, a practical diagnostic algorithm is proposed accounting for current molecular approaches, enzyme testing sensitivity, and variability due to gender, cell/tissue type used for testing, and successive repeat testing.

Use of metal/metal oxide spherical cluster and hydroxyl metal coordination complex for descriptor calculation in development of nanoparticle cytotoxicity classification model

Computational approaches have been suggested as an informative tool for risk assessment of nanomaterials. Nano (quantitative) structure-activity relationship, nano-(Q)SAR, models have been developed to predict toxicity of metal oxide (MOx) nanoparticles (NPs); however, the packing structure and cluster of nanoparticle have been included for the descriptor calculation in only two studies. This study proposed spherical cluster and hydroxyl metal coordination complex to calculate descriptors for development of nanoparticle cytotoxicity classification model. The model cluster was generated from metal (M) or MOx crystal structure to calculate physicochemical properties of M/MOx NPs and the hydroxyl metal coordination complex was used to calculate the properties of the metal cation in an aqueous environment. Data were collected for 2 M and 19 MOx NPs in human bronchial epithelial cell lines and murine myeloid cell lines at 100 μg/ml after 24 hours exposure. The model was developed with scaled HOMO energy of the model cluster and polarizability of the hydroxyl metal coordination complex, as reactivity of the particles and the cations explained cause of cytotoxic action by M/MOx NPs. As the developed model achieved 90.31% accuracy, the classification model in this work can be used for virtual screening of toxic action of M/MOx NPs.

The Superiority of IFN-λ as a Therapeutic Candidate to Control Acute Influenza Viral Lung Infection

Here, we studied the IFN-regulated innate immune response against influenza A virus (IAV) infection in the mouse lung and the therapeutic effect of IFN-λ2/3 in acute IAV lung infection. For viral infections, IAV (WS/33, H1N1, PR8 H1N1, H5N1) were inoculated into wild-type mice by intranasal delivery, and IAV mRNA level and viral titer were measured. To compare the antiviral effect of IFNs in vivo in the lung, neutralizing antibodies and recombinant IFNs were used. After intranasal inoculation of IAV into mice, viral infection peaked at 7 days postinfection, and the IAV titer also reached its peak at this time. We found that IFN-β and IFN-λ2/3 were preferentially induced after IAV infection and the IFN-λ2/3-mediated innate immune response was specifically required for the induction of IFN-stimulated genes (ISGs) transcription in the mouse respiratory tract. Neutralization of secreted IFN-λ2/3 aggravated acute IAV lung infection in mice with intact IFN-β induction; consistent with this finding, the transcription of ISGs was significantly reduced. Intranasal administration of IFN-λ2/3 significantly suppressed various strains of IAV infection, including WS/33 (H1N1), PR (H1N1), and H5N1 in the mouse lung, and was accompanied by greater up-regulation of ISGs. Taken together, our data indicate that the IFN-λ2/3-mediated innate immune response is necessary to protect the lungs from IAV infection, and intranasally delivered IFN-λ2/3 has the potential to be a useful therapeutic strategy for treating acute IAV lung infection.

Piriformis ganglion: An uncommon cause of sciatica

Sciatica can occur due to a spinal lesion, intrapelvic tumor, diabetic neuropathy, and rarely piriformis syndrome. The causes of piriformis syndrome vary by a space-occupying lesion. A ganglionic cyst can occur in various lesions in the body but seldom around the hip joint. In addition, sciatica due to a ganglionic cyst around the hip joint has been reported in one patient in Korea who underwent surgical treatment. We experienced two cases of sciatica from a piriformis ganglionic cyst and we report the clinical characterics and progress after non-operative treatment by ultrasonography-guided aspiration. The two cases were diagnosed by magnetic resonance imaging and were treated by ultrasonography-guided aspiration. We followed the patients for more than 6months. The symptoms of piriformis syndrome from the ganglion improved following aspiration and this conservative treatment is a treatment method that can be used without extensive incision or cyst excision.

LEVEL OF EVIDENCE

Level IV historical case.

Formation mechanism and red light emission photoluminescence of single-phase crystalline Eu2O2CO3 nanoplates compared with Y2O3:Eu phosphor

The photoluminescence properties and formation mechanism of a novel stoichiometric phosphor are presented. Nanoplates of pure single-phase crystalline Eu2O2CO3 oxycarbonate (hexagonal type-II) were synthesized by dry autoclaving under autogenic pressure (under 3 MPa) using an efficient, high yield solid state green-chemistry route that can be extended to other rare-earth oxycarbonate and oxide systems, resulting in the full conversion of a simple commercial precursor in single-crystalline nanoplates with strong visible luminescence. Phosphors made of an oxide host and an active luminescent dopant ion are the commercial standard (i.e., Y2O3:Eu). It is generally considered that the activity of luminescent species, such as Eu3+, is quenched and disappears above a certain concentration of them in the lattice (concentration quenching). The truly stoichoimetric oxycarbonate phosphor without active dopant ions exhibits very strong red emission when excited by different excitations, in the UV and visible range, without any concentration quenching effect. The bright red light emission spectra of the of the photo-excited phosphor nanoplates under UV and visible light excitation is compared with that of a standard Y2O3:Eu commercial red phosphor powder, and the thermal conversion mechanism is proposed to obtain the single-phase stable stoichiometric oxycarbonate nanoplates.

Modulation of the murine microbiome with a concomitant anti-obesity effect by Lactobacillus rhamnosus GG and Lactobacillus sakei NR28

The microbiota of the gastrointestinal tract (GIT) constitutes the major part of the total human microbiome and is considered to be an important regulator of human health and host metabolism. Numerous investigations in recent years have focused on the connection between the human microbiota and metabolic diseases such as obesity, type II diabetes and atherosclerosis. Yet, little is known about the impact of probiotic consumption on the GIT microbial population and the potential effect on chronic diseases. In this study, the modulation of the microbial community in the murine small intestine resulting from probiotic feeding was investigated and was found to be associated with an anti-obesity effect. Changes in the microbiota of the mouse faeces and small intestine were monitored using quantitative real-time PCR and by following the mRNA expression levels of various obesity-related biomarkers following probiotic feeding in a mouse model. Lactobacillus rhamnosus GG and Lactobacillus sakei NR28 (a putative probiotic strain isolated from kimchi) were administered at a daily level of approximately 1×10(8) viable bacteria per mouse (C57BL/6J mice) for up to three weeks. Feeding these strains resulted in a significant reduction of epididymal fat mass, as well as obesity-related biomarkers like acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase-1 in the liver. The total number and ratio of the microbial groups, i.e. Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp. were modulated in the small intestine, and the Firmicutes:Bacteroidetes ratio was decreased. In contrast, no noticeable effect of probiotic feeding could be detected on the faecal microbiota, neither quantitatively, nor with regard to the bacterial groups (Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp.) studied.

Dynamics of relaxation and fragmentation in size-selected icosahedral Ar(n)[NO(-)(v = 1)] clusters

We study the vibrational relaxation and solvation dynamics in size-selected icosahedral Ar(n)(NO(-)) at 300 K, where NO(-)(X(3)Σ(-)) is in v = 1 and n = 1-12, using a classical dynamics method and an interaction model consisting of detailed host-guest and host-host interactions. Two relaxation time scales are found: (i) the short-time (<200 ps), in which rate is nearly independent of cluster size, and (ii) the ns scale, in which a slow energy transfer process occurs between NO(-) vibration and argon modes at a rate (~10(8) s(-1)) decreasing slightly from n = 12 to 6 and rapidly from n = 5 to 1 (~10(6) s(-1)). In Ar(12)(NO(-)), less than one-quarter of the host atoms sampled evaporate, nearly 60% of evaporation occurring within 200 ps caused by rapid energy transfer from NO(-) at short time. The fraction of evaporation decreases nearly exponentially with increasing evaporation time, but ~16% of evaporation still occurs on a time scale longer than 1 ns. Evaporation from one hemisphere of Ar(12)(NO(-)) dominates the rest. Final cluster sizes commonly produced from the fragmentation of Ar(12)(NO(-)) are n = 6-11 (evaporation of 6-1 atoms) and n = 12 (no evaporation).

Selective activation of Akt1 by mammalian target of rapamycin complex 2 regulates cancer cell migration, invasion, and metastasis

Mammalian target of rapamycin complex (mTORC) regulates a variety of cellular responses including proliferation, growth, differentiation and cell migration. In this study, we show that mammalian target of rapamycin complex 2 (mTORC2) regulates invasive cancer cell migration through selective activation of Akt1. Insulin-like growth factor-1 (IGF-1)-induced SKOV-3 cell migration was completely abolished by phosphatidylinositol 3-kinase (PI3K) (LY294002, 10 μM) or Akt inhibitors (SH-5, 50 μM), whereas inhibition of extracellular-regulated kinase by an ERK inhibitor (PD98059, 10 μM) or inhibition of mammalian target of rapamycin complex 1 (mTORC1) by an mTORC1 inhibitor (Rapamycin, 100 nM) did not affect IGF-1-induced SKOV-3 cell migration. Inactivation of mTORC2 by silencing Rapamycin-insensitive companion of mTOR (Rictor), abolished IGF-1-induced SKOV-3 cell migration as well as activation of Akt. However, inactivation of mTORC1 by silencing of Raptor had no effect. Silencing of Akt1 but not Akt2 attenuated IGF-1-induced SKOV-3 cell migration. Rictor was preferentially associated with Akt1 rather than Akt2, and over-expression of Rictor facilitated IGF-1-induced Akt1 activation. Expression of PIP3-dependent Rac exchanger1 (P-Rex1), a Rac guanosine exchange factor and a component of the mTOR complex, strongly stimulated activation of Akt1. Furthermore, knockdown of P-Rex1 attenuated Akt activation as well as IGF-1-induced SKOV-3 cell migration. Silencing of Akt1 or P-Rex1 abolished IGF-1-induced SKOV-3 cell invasion. Finally, silencing of Akt1 blocked in vivo metastasis, whereas silencing of Akt2 did not. Given these results, we suggest that selective activation of Akt1 through mTORC2 and P-Rex1 regulates cancer cell migration, invasion and metastasis.

Vibrational relaxation of NO-(v=1) in icosahedral (Ar)12NO- clusters

Relaxation dynamics of NO(-)(v=1) in icosahedral (Ar)(12)NO(-) clusters are studied using classical dynamics and semiclassical procedures over the temperature range of 100-300 K. The minimum energy of the equilibrium configuration (-9875 cm(-1)) needed in the study is determined by varying the cluster size z in (Ar)(z)NO(-). NO(-)(v=1) is embedded in the cluster, which is filled with low frequency motions: 39 cm(-1) for the argon modes, 77 cm(-1) for the Arc...NO(-) substructure vibration, 109 cm(-1) for the librational frequency of restricted rotation, and 128 cm(-1) for oscillatory local translation. Dynamics calculations show that in the early time period (<20 ps), part of the vibrational energy rapidly transfers to rotation, but most energy transfers to Ar atoms on a long time scale (approximately 1 ns). The long time scale leads to the relaxation rates of 0.403 ns(-1) at 100 K and 0.453 ns(-1) at 300 K. The rates calculated using analytical formulations vary nearly linearly from 0.288 ns(-1) at 100 K to 0.832 ns(-1) at 300 K. Although the temperature dependence is stronger in the latter, both approaches give the rates on a nanosecond time scale. The principal energy transfer pathway is from NO(-) vibration to Ar vibrations via oscillatory local translation, while the NO(-) rotation is in a librational state. The energy transfer probabilities are two orders of magnitude larger than the vibration-to-translation probabilities in the gas phase collision Ar-NO(-)(v=1).

Middle cerebral artery occlusive disease: the New England Medical Center Stroke Registry

To analyze the clinical features, vascular lesions, and infarct distribution in Asian and white patients with middle cerebral artery (MCA) territory ischemia, we studied age, sex, race, risk factors, angiographic, and neuroimaging findings among patients in the New England Medical Center Stroke Registry. We included patients with well-defined intrinsic occlusive lesions of the MCAs and patients with embolic MCA territory infarcts. Among 695 patients in the stroke registry, 89 (12.8%) qualified. They had 28 MCA intrinsic stenoses, 17 MCA embolic occlusions (cardiogenic or unknown origin), and 44 carotid artery (CA) stenoses or occlusions. MCA intrinsic disease patients were more often Asians and women, and more often had hypertension. Asians were older than whites. Coronary artery disease (27%), peripheral vascular disease (20.5%), and smoking (39%) were more common in CA disease patients. The most common site of MCA intrinsic stenosis (78%) and embolic occlusion (59%) was the mainstem MCA. Infarcts in patients with MCA intrinsic disease mostly involved the striatocapsular area (61%). Infarcts in patients with MCA embolic occlusion (75%) and CA disease (43%) most often involved the parietal lobe. In our hospital, most patients with MCA intrinsic disease are Asians and women and have hypertension and striatocapsular infarctions. Asian patients are usually older than white patients. The most common site of vascular lesions is the mainstem MCA.

Vibrational relaxation of trapped molecules in solid matrices: OH(A 2Sigma+; v = 1)/Ar

The vibrational relaxation of OH(A (2)Sigma(+);v=1) embedded in solid Ar has been studied over 4-80 K. The interaction model is based on OH undergoing local motions in a cage formed by a face-centered cubic stacking where the first shell atoms surround the guest and connect it to the heat bath through 12 ten-atom chains. The motions confined to the cage are the local translation and libration-rotation of OH and internal vibrations in OH...Ar, their energies being close to or a few times the energies of nearby first shell and chain atoms. The cage dynamics are studied by solving the equations of motion for the interaction between OH and first shell atoms, while energy propagation to the bulk phase through lattice chains is treated in the Langevin dynamics. Calculated energy transfer data are used in semiclassical procedure to obtain rate constants. In the early stage of interaction, OH transfers its energy to libration-rotation intramolecularily and then to the vibrations of the first shell and chain atoms on the time scale of several picoseconds. Libration-to-rotational transitions dispense the vibrational energy in small packages comparable to the lattice frequencies for ready flow. Energy propagation from the chains to the heat bath takes place on a long time scale of 10 ns or longer. Over the solid argon temperature range, the rate constant is on the order of 10(6) s(-1) and varies weakly with temperature.

Classical trajectory study of the formation of XeH+ and XeCl+ in the Xe++HCl collision

The collision-induced reaction of Xe+ with HCl has been studied by use of classical dynamics procedures at collision energies 2-20 eV using empirical potential parameters. The principal reaction pathway on the potential energy surface is the formation of XeH+ with the maximum reaction cross section, 1.2 A2, occurring at E=9 eV. At lower energies, the cross section for the charge transfer process Xe++HCl-->Xe+HCl+ is comparable to that for XeH+ formation, but at higher energies, it is larger by a factor of 2. The cross section of the XeCl+ formation is an order of magnitude smaller than that of XeH+. For both XeH+ and XeCl+ formations, the reaction threshold is approximately 2 eV. The XeH+ formation takes place immediately following the turning point in a direct-mode mechanism, whereas an indirect-mode mechanism operates in the formation of XeCl+. Both XeH+ and XeCl+ formations come mainly from the perpendicular configuration, Xe+...HCl, at the turning point. Product vibrational excitation is found to be strong in both XeH+ and XeCl+.

Host-assisted intramolecular vibrational relaxation at low temperatures: OH in an argon cage

The vibrational relaxation of hydroxyl radicals in the A (2)Sigma(+) (v=1) state has been studied using the semiclassical perturbation treatment at cryogenic temperatures. The radical is considered to be trapped in a closest packed cage composed of the 12 nearest argon atoms and undergoes local translation and hindered rotation around the cage center. The primary relaxation pathway is towards local translation, followed by energy transfer to rotation through hindered-to-free rotational transitions. Free-to-free rotational transitions are found to be unimportant. All pathways are accompanied by the propagation of energy to argon phonon modes. The deexcitation probability of OH(v=1) is 1.3 x 10(-7) and the rate constant is 4.7 x 10(5) s(-1) between 4 and 10 K. The negligible temperature dependence is attributed to the presence of intermolecular attraction (>>kT) in the guest-host encounter, which counteracts the T(2) dependence resulting from local translation. Calculated relaxation time scales are much shorter than those of homonuclear molecules, suggesting the importance of the hindered and free motions of OH and strong guest-host interactions.

Collision-induced dissociation of transition metal-oxide ions: dynamics of VO+ collision with Xe

The collision-induced dissociation of VO(+) by Xe has been studied by the use of classical dynamics procedures on London-Eyring-Polanyi-Sato potential-energy surfaces in the collision energy range of 5.0-30 eV. The dissociation threshold behavior and the dependence of reaction cross sections on the collision energy closely follow the observed data with the threshold energy of 6.00 eV. The principal reaction pathway is VO(+) + Xe --> V(+)+ O + Xe and the minor pathway is VO(+) + Xe--> VXe(+) + O. At higher collision energies (E > 8.0 eV), the former reaction preferentially occurs near the O-V(+)...Xe collinear and perpendicular alignments, but the latter only occurs near the perpendicular alignment. At lower energies close to the threshold, the reactions are found to occur near the collinear configuration. No reaction occurs in the collinear alignment V(+)-O...Xe. The high and low energy-transfer efficiencies of the collinear alignments O-V(+)...Xe and V(+)-O...Xe are attributed to the effects of mass distribution. The activation of the VO(+) bond toward the dissociation threshold occurs through a translation-to-vibration energy transfer in a strong collision on a time scale of about 50 fs.

Vibrational Relaxation of Molecular Ions at Low Temperatures: O2-(v=1) + Ar

The vibrational relaxation of oxygen molecular ions trapped in an argon cage in the temperature range 10-85 K has been studied using semiclassical procedures. The collision model is based on the trapped molecule undergoing the restricted motions (local translation and hindered rotation) in a cage formed by its 12 nearest argon neighbors in a face-centered cubic arrangement. At 85 K in the liquid argon temperature range, the relaxation rate constant of O2(-) (v=1) is 1130 s(-1). The rate constant decreases to 270 s(-1) at 50 K and to 3.90 s(-1) at 10 K in the solid argon temperature range. In the range 10-85 K, the rate constant closely follows the temperature dependence k proportional to T2.7. Energy transfer pathways for the trapped molecular ion are vibration to local translation, argon phonon modes, and rotation (both hindered and free).

Vibrational relaxation of oxygen in an argon cage

The vibrational relaxation of oxygen embedded in an argon cage through vibrational to local translation, rotation, and argon phonon modes has been studied using semiclassical procedures. The collision model is based on the trapped molecule undergoing the restricted motions (local translation and hindered rotation) in a cage formed by its twelve nearest argon neighbors in a face-centered-cubic structure. At 85 K in the liquid argon temperature range, the deexcitation probability of O(2)(v=1) is 5.8 x 10(-12) and the relaxation rate constant with the collision frequency from local translation is 23 s(-1). The rate constant decreases to 5.1 s(-1) at 50 K and to 0.016 s(-1) at 10 K in the solid argon temperature range. Transfer of the vibrational energy to local translation, rotation (both hindered and free), and argon phonon modes is the relaxation pathway for the trapped oxygen molecule.

Efficacy of pre-emptive milrinone in off-pump coronary artery bypass surgery: comparison between patients with a low and normal pre-graft cardiac index

OBJECTIVE

The effect of pre-emptive milrinone without bolus during off-pump coronary artery bypass surgery (OPCAB) was evaluated in two groups of patients with low and normal pre-graft cardiac index.

METHODS

Eighty-two patients were divided into two groups based on their pre-graft cardiac index. Each group was randomly subdivided into two groups to receive either milrinone or normal saline. After the internal mammary artery was harvested, the infusion of milrinone, or normal saline was started and maintained until the end of the anastomosis. The haemodynamic variables were measured: just before the start of milrinone or normal saline after pericardiotomy (baseline value); 10 min after the tissue stabilizer had been applied for the anastomosis of left anterior descending artery, left circumflex artery and right coronary artery; and after the sternal closure.

RESULTS

Milrinone reduced the extent of the decrease in cardiac index and stroke volume as well as the extent of the increase in systemic and pulmonary vascular resistance. The extent of the decrease in cardiac index and mixed venous oxygen saturation were greater in normal pre-graft cardiac index group than in low pre-graft cardiac index group regardless of milrinone infusion during anastomoses. The effect of milrinone on haemodynamics showed no significant difference between low and normal pre-graft cardiac index groups.

CONCLUSIONS

Pre-emptive milrinone infusion without bolus effectively improved cardiac performance during OPCAB and was especially useful for patients with low pre-graft cardiac index to prevent the decrease in cardiac index and stroke volume index below the critical level.

4G/5G polymorphism of the plasminogen activator inhibitor-1 gene and insertion/deletion polymorphism of the tissue-type plasminogen activator gene in atherothrombotic stroke

BACKGROUND AND PURPOSE

Decreased fibrinolytic capacity due to increased plasminogen activator inhibitor-1 (PAI-1) activity and decreased tissue-type plasminogen activator (t-PA) activity has been associated with hypertension or atherothrombotic disorders. The aims of this study were to observe associations of the genetic polymorphism for PAI-1 and t-PA with hypertension and atherothrombotic stroke, and to elucidate whether impaired fibrinolytic activity in atherothrombotic stroke was related to atherothrombosis per se or to other risk factors such as hypertension.

METHODS

Patients with atherothrombotic stroke (n = 60), hypertension (n = 100), and control subjects (n = 100) were enrolled. We genotyped all subjects for 4G/5G polymorphism in the promoter region of the PAI-1 gene and the Alu-repeat insertion/deletion (I/D) polymorphism in intron h of the t-PA gene by polymerase chain reaction and endonuclease digestion.

RESULTS

The frequency of the 4G/4G genotype of PAI-1 was significantly higher in the atherothrombotic stroke patients than the control subjects (41.7 versus 21%; p = 0.005), but not in the hypertensive subjects. There was a significant association between 4G/4G genotype of PAI-1 and atherothrombotic stroke (adjusted odds ratio = 3.11, 95% confidence interval 1.18-8.15), adjusting for age, sex, total cholesterol, low-density lipoprotein, triglyceride, and body mass index. However, the number of the I/I genotype of t-PA in the atherothrombotic stroke or hypertensive patients was virtually identical to the control subjects.

CONCLUSION

Our results suggest that the 4G/4G genotype of the PAI-1 gene is significantly associated with an increased risk of atherothrombotic stroke. This finding also supports that impaired fibrinolytic activity in atherothrombotic stroke is related to atherothrombosis per se, but not to hypertension, one of the most important risk factors of atherothrombotic stroke.

Typing of clinical isolates of Mycobacterium leprae and their distribution in Korea

Although there is no genetic diversity in isolates of Mycobacterium leprae, the variance of tandem repeats in the rpoT gene was recently demonstrated. We have typed clinical isolates of M. leprae in Korea using difference of the tandem repeats in the rpoT gene. Among 69 patients, 65 Korean isolates (94.2%) demonstrated four copies of the 6 bp tandem repeat (GACATC) in the rpoT gene, and incidences of three copies were found in only two Koreans and two foreigners (2.9%, respectively).

Restoration of vasodilation and CBF autoregulation by genistein in rat pial artery after brain injury

This study determined whether, after fluid percussion injury (FPI), tyrosine kinase activation is coupled to inhibition of K(+) channels and alteration in cerebral blood flow (CBF) autoregulation in the rat pial artery. Injury of moderate severity (2--2.5 atm) was produced by FPI in anesthetized rats equipped with a closed cranial window. The suppressed vasodilation of the pial arterioles to calcitonin gene-related peptide (CGRP) and levcromakalim (LMK) and altered lower limit of CBF autoregulation after FPI were restored by genistein but not by daidzein, an inactive analog. Vasodilation to S-nitroso-N-acetyl penicillamine (0.1--10 micromol/l) was, however, little influenced after FPI. The restored vasodilation was decreased by sodium orthovanadate, suggesting the reciprocal action of tyrosine phosphorylation and dephosphorylation. After FPI, CGRP-induced vasodilation restored by genistein (10 micromol/l) was strongly antagonized by iberiotoxin but not by glibenclamide, whereas LMK-induced vasodilation was, in contrast, inhibited by glibenclamide but not by iberiotoxin. Taken together, we suggest that, after FPI, activation of tyrosine kinase links the inhibition of K(+) channels to impaired autoregulatory vasodilation in response to acute hypotension and alteration in CBF autoregulation in the rat pial artery.

Striatocapsular haemorrhage

Haemorrhages in the striatocapsular area, or striatocapsular haemorrhages (SCHs), have been regarded as a single entity, although the area is composed of several functionally discrete structures that receive blood supply from different arteries. We analysed the morphological and clinical presentations of 215 cases of SCHs according to a new classification method we have designed on the basis of arterial territories. SCHs were divided into six types: (i) anterior type (Heubner's artery); (ii) middle type (medial lenticulostriate artery); (iii) posteromedial type (anterior choroidal artery); (iv) posterolateral type (posteromedial branches of lateral lenticulostriate artery); (v) lateral type (most lateral branches of lateral lenticulostriate artery); and (vi) massive type. The anterior type (11%) formed small caudate haematomas, always ruptured into the lateral ventricle, causing severe headache, and mild contralateral hemiparesis developed occasionally. The outcome was excellent. The middle type (7%) involved the globus pallidus and medial putamen, frequently causing contralateral hemiparesis and transient conjugate eye deviation to the lesion side. About 50% of the patients recovered to normal. The posteromedial type (4%) formed very small haematomas in the posterior limb of the internal capsule and presented with mild dysarthria, contralateral hemiparesis and sensory deficit, with excellent outcome in general. The posterolateral type (33%) affected the posterior half of the putamen and posterior limb of the internal capsule and presented with impaired consciousness and contralateral hemiparesis with either language dysfunction or contralateral neglect. The outcome was fair to poor but there were no deaths. The lateral type (21%) formed large elliptical haematomas between the putamen and insular cortex. Contralateral hemiparesis with language dysfunction or contralateral neglect developed frequently but resolved over several weeks. The clinical outcome was relatively excellent except when the haematoma size was very large. The massive type (24%) formed huge haematomas affecting the entire striatocapsular area. Marked sensorimotor deficits and impaired consciousness, ocular movement dysfunctions including the 'wrong-way' eyes were observed quite frequently. The outcome was very poor with a case fatality rate of 81%. The clinico-radiological presentations suggested its origin was the same as the posterolateral type.

Implication of adenosine A2A receptors in hypotension-induced vasodilation and cerebral blood flow autoregulation in rat pial arteries

This study aimed to evaluate the role for adenosine A2A receptors in the autoregulatory vasodilation to hypotension in relation with cerebral blood flow (CBF) autoregulation in rat pial arteries. Changes in pial artery diameters were observed directly through a closed cranial window. Vasodilation induced by adenosine was markedly suppressed by ZM 241385 (1 micromol/l, A2A antagonist) and alloxazine (1 micromol/l, A2B antagonist), but not by 8-cyclopentyltheophylline (CPT, 1 micromol/l, A1 antagonist). CGS-21680-induced vasodilation was more strongly inhibited by ZM 241385 (25.3-fold; P<0.05) than by alloxazine. In contrast, 5'-N-ethylcarboxamido-adenosine (NECA)-induced vasodilation was more prominently suppressed by alloxazine (12.0-fold; P<0.001) than by ZM 241385. The autoregulatory vasodilation in response to acute hypotension of the pial arteries was significantly suppressed by ZM 241385, but not by CPT and alloxazine. Consistent with this finding, the lower limit of CBF autoregulation significantly shifted to a higher blood pressure by 1 micromol/l of ZM 241385 (53.0+/-3.9 mm Hg to 69.2+/-2.9 mm Hg, P<0.01) and 10 micromol/l of glibenclamide (54.7+/-6.5 mm Hg to 77.9+/-4.2 mm Hg, P<0.001), but not by CPT and alloxazine. Thus, it is suggested that adenosine-induced vasodilation of the rat pial artery is mediated via activation of adenosine A2A and A2B receptors, but not by A1 subtype, and activation of adenosine A2A receptor preferentially contributes to the autoregulatory vasodilation via activation of ATP-sensitive K+ channels in response to hypotension and maintenance of CBF autoregulation.

Role of adenosine A(2B) receptors in vasodilation of rat pial artery and cerebral blood flow autoregulation

This study was aimed to investigate the underlying mechanism of vasodilation induced by the activation of A(2B) adenosine receptors in relation to cerebral blood flow (CBF) autoregulation. Changes in pial arterial diameters were observed directly through a closed cranial window. N(omega)-nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor) significantly suppressed the concentration-dependent vasodilations induced by adenosine and 5'-N-ethylcarboxamido-adenosine (NECA) but not the vasodilation by CGS-21680 (A(2A)-receptor agonist). Moreover, NECA-induced vasodilation was suppressed by alloxazine (1 micromol/l) but not by ZM-241385 (1 micromol/l, A(2A) antagonist), which suggests mediation by A(2B)- receptor activation. Otherwise, the level of nitrite/nitrate was concentration dependently increased in the artificial cerebrospinal fluid (CSF) when adenosine and NECA were suffused over the cortical surface. L-NAME and alloxazine, but not ZM-241385, largely inhibited their releases. The lower limit of CBF autoregulation was little affected following pretreatment with L-NAME or alloxazine. Thus it is suggested that adenosine-induced vasodilation via activation of A(2B)-adenosine receptors of the rat pial artery is coupled to the production of nitric oxide, which contributes little to CBF autoregulation.

Needle thoracic sympathectomy for essential hyperhidrosis: intermediate-term follow-up

BACKGROUND

Essential hyperhidrosis is a condition with excessive sweating localized to certain part of the body. A definitive cure can be obtained by upper thoracic sympathectomy.

METHOD

Between June and October 1997, 117 patients with essential hyperhidrosis underwent needle thoracoscopic sympathectomy. Of the 94 patients, 42 were men and 52 women. Their ages ranged from 14 to 63 years, with a mean age of 23 years.

RESULTS

There were no mortality or life-threatening complications. Symptomatic improvement was found in 95.7%. Compensatory hyperhidrosis was found in 71.2% of the patients, but in these compensatory hyperhidrosis were mostly tolerable.

CONCLUSIONS

This therapeutic procedure is minimally invasive and very effective. Further development of the new device and surgical technique are expected to follow.

Thoracoscopic sympathetic surgery for hyperhidrosis

Resectional surgery of sympathetic nerves has been known to be the most effective treatment for essential hyperhidrosis and the application of thoracoscopic electrocauterization has provided a minimally-invasive procedure with the least morbidity and a resultant higher satisfaction rate. This paper describes our experience on the 1,167 cases of thoracoscopic sympathetic surgery for the treatment of essential hyperhidrosis. A total of 1,167 patients (674 males (58%) and 493 females (42%), mean age of 26.4 years with palmar (930), craniofacial (190) or axillary (47) hyperhidrosis underwent thoracoscopic sympathetic surgery from July 1992 to March 1999. Since the T2-4 sympathectomy, first performed in July 1992 for a patient of palmar hyperhidrosis, the operative methods have been altered to achieve a higher satisfaction level with the least complication by adopting less invasive procedures. Our current standard procedures being performed are T3 and T2 clipping for palmar and craniofacial hyperhidrosis and T3,4 sympathicotomy for axillary hyperhidrosis, all using a 2 mm needle thoracoscope. As the surgical procedures have been transited to a less invasive method with limited resection using the newest endoscopic devices, the average operation time and complications such as Horner's syndrome and compensatory hyperhidrosis have gradually decreased and thus the long-term satisfaction rate has been raised up to 98% for palmar hyperhidrosis, 92% for craniofacial hyperhidrosis and 89% for axillary hyperhidrosis. The recurrent cases (14/1167) were treated successfully with reoperations of thoracoscopic sympathetic surgery. The optimal goal of therapy could be achieved by complete elimination of the hyperhidrotic symptom, by decreasing the incidence and degree of compensatory hyperhidrosis through a selective and limited resection, and by adopting the least invasive procedures. Sympathicotomy has provided the advantages of a limited extent of denervation and the resultant decrease of compensatory hyperhidrosis compared to sympathectomy. The reversible method of clipping may be an effective, provisionary means for cases of severe, intractable compensatory sweating. For craniofacial hyperhidrosis, T2 sympathicotomy or clipping has been proven to be superior to the T1 sympathectomy due to the decreased occurrence of Horner's syndrome and T3,4 sympathicotomy providing a satisfactory outcome with less compensatory hyperhidrosis for axillary hyperhidrosis.

Bilateral intracranial vertebral artery disease in the New England Medical Center, Posterior Circulation Registry

BACKGROUND

Previous studies of patients with bilateral intracranial vertebral artery (ICVA) disease were selective and retrospective.

METHODS

We studied risk factors, vascular lesions, symptoms, signs, and outcomes in patients with bilateral ICVA disease among 430 patients in the New England Medical Center Posterior Circulation Registry.

RESULTS

Forty-two patients had bilateral ICVA occlusive disease (18 had bilateral stenosis; 16, unilateral occlusion and contralateral stenosis; and 8, bilateral occlusion). The most common risk factors were hypertension (32/42 [76%]) and hyperlipidemia (22/42 [52%]). Sixteen patients (38%) had transient ischemic attacks (TIAs) only; 18 (43%), TIAs before stroke. Occlusive vascular disease also involved the basilar artery in 29 patients (69%), the extracranial vertebral arteries in 18 (43%), and the internal carotid arteries in 11 (26%). Only 6 patients had no other major vascular lesion. Cerebellar symptoms were common. Among 30 patients with infarction, 21 (70%) had proximal intracranial territory involvement, and 15 (50%) had distal territory involvement. The location of occlusive lesions in relation to posterior inferior cerebellar artery origins did not significantly influence prognosis. During follow-up, 31 patients had no symptoms or slight disability, 2 had progression, and 7 died. Among 7 patients with poor outcome, 6 also had basilar artery stenosis or occlusion and 5 had proximal and distal intracranial territory infarcts.

CONCLUSIONS

Most patients with bilateral ICVA occlusive disease have hypertension, other major occlusive lesions, and TIAs before stroke. Short- and long-term outcomes are usually favorable, but patients with bilateral ICVA and basilar artery-occlusive lesions often have poor outcomes.

Cytotoxic effects of the components in heat-treated mistletoe (Viscum album)

Major cytotoxic components were fractionated from Korean mistletoe and the changes of their cytotoxic effects caused by heat treatment were investigated. The high cytotoxicity of isolated lectin I completely disappeared by heating for 30 min. The fractions of viscotoxins and alkaloids maintained their activities even after heating for 60 and 180 min, respectively. The alkaloid fraction was more cytotoxic to tumor MSV cells than to non-tumor A31 cells and the activity pattern was not changed by heat treatment. The possible contributions of alkaloids and viscotoxins to the activities of heat-treated mistletoe extracts such as tea or decoctions are discussed.

Metabolism of cAMP to adenosine: role in vasodilation of rat pial artery in response to hypotension

The purpose of this experiment was to examine whether the cAMP-adenosine pathway is implicated in the autoregulatory vasodilation in response to hypotension. Suffusion with cAMP (1-100 micromol/l) or adenosine (0.01-10 micromol/l) caused a sustained vasodilation of the resting pial arteries in a concentration-dependent manner. In contrast, N6,2'-O-dibutyryl-cAMP and 8-bromo-cAMP exerted a weak dilation at high concentration (100 micromol/l). The vasodilation to cAMP (1-100 micromol/l), adenosine (0.01-10 micromol/l), and hypotension was significantly reduced by pretreatment with 3,7-dimethyl-1-propargylxanthine (1 micromol/l), an A2 receptor antagonist, as well as 3-isobutyl-1-methylxanthine (3 micromol/l), an inhibitor of endo- and ectophosphodiesterase, 1, 3-dipropyl-8-p-sulfophenylxanthine (100 micromol/l), an inhibitor of ecto-5'-phosphodiesterase, or alpha,beta-methylene-adenosine 5'-diphosphate (100 micromol/l), an inhibitor of ecto-5'-nucleotidase. However, 8-cyclopentyltheophylline (1 micromol/l), an A1 antagonist, did not elicit a similar response. The increased release of adenosine when the cortical surface was suffused with cAMP (100 micromol/l) was significantly reduced by 3-isobutyl-1-methylxanthine, 1,3-dipropyl-8-p-sulfophenylxanthine, and alpha,beta-methylene-adenosine 5'-diphosphate (each 100 micromol/l). These results indicate that the cAMP-adenosine pathway as a viable metabolic mechanism is implicated in the production of adenosine in the rat pial artery and contributes to the regulation of vasodilation in response to hypotension.

Quinoline alkaloids from the fruits of Evodia officinalis

A new quinoline derivative, 2-hydroxy-4-methoxy-3-(3'-methyl-2'-butenyl)-quinoline and five known quinoline alkaloids were isolated from the fruits of Evodia officinalis. The structure of 1 was determined by spectroscopic methods.

The water-soluble extract of chicory influences serum and liver lipid concentrations, cecal short-chain fatty acid concentrations and fecal lipid excretion in rats

Sprague-Dawley rats (n = 32) were fed diets without fiber (control) or containing 1 or 5% chicory extract or 5% inulin for 4 wk; 0.2% cholesterol was added to all diets. Rats fed chicory extract and inulin diets had significantly higher serum high density lipoprotein (HDL) cholesterol and generally lower low density lipoprotein (LDL) cholesterol concentrations, thus significantly greater ratios of HDL/LDL cholesterol compared with the controls (P < 0.05). The serum apolipoprotein B/apolipoprotein A-1 ratio was significantly lower in rats fed diets containing chicory extract or inulin than that in rats fed fiber-free diets, due to significant reductions in apolipoprotein B concentration (P < 0.05). Greater liver lipid and triglyceride concentrations were observed in rats fed chicory extract or inulin diets compared with the controls (P < 0.05). However, liver phospholipid and cholesterol concentrations were not significantly different among groups (P > 0.05). Addition of 5% inulin to the diet resulted in greater cecal weight, whereas both 5% chicory extract and 5% inulin resulted in greater cecal propionic acid concentration compared with the controls (P < 0.05). Rats fed chicory extract and inulin had significantly greater fecal lipid, cholesterol and bile acid excretions than those fed fiber-free diets (P < 0.05). The results of this study suggest that the improved lipid metabolism observed in rats fed chicory extract (mainly inulin component) may be caused by an alteration in the absorption and/or synthesis of cholesterol, which might result from the changes in cecal fermentation, and by an increase in the fecal excretion of lipid, cholesterol and bile acid.

Cytotoxicity of heat-treated Korean mistletoe

The cytotoxic effects of preparations of Korean mistletoe (Viscum album L. var. coloratum Ohwi) on non-tumorigenic A31 cells and tumorigenic MSV cells were investigated. While the aqueous extract from Korean mistletoe (<8 microg/ml) showed strong cytotoxicity on both cell lines, the heat-treated extract was much less cytotoxic with TD50 values of above 300 microg/ml. The heat-treated extract showed a growth-enhancing effect on non-tumorigenic cells and a cytotoxic effect on tumorigenic cells. The alkaloids fraction, which was isolated from the crude extract, was not cytotoxic to non-tumorigenic A31 cells up to 550 microg/ml, but was cytotoxic to tumorigenic MSV cells at 138 microg/ml. Heat treatment did not change the cytotoxic effects of the alkaloids fraction, indicating that the selective cytotoxicity of the heat-treated mistletoe extract on tumorigenic MSV cells might be due to its alkaloids. In order to study the changes in the cytotoxicity of fermented Korean mistletoe, the crude and heat-treated extracts were inoculated with Lactobacillus plantarum. During 7 days of fermentation, the cytotoxicity of the fermented heat-treated extract was increased while that of the fermented crude extract was not changed significantly.

Influenza vaccination in 22 developed countries: an update to 1995

This study expands and updates through 1995 our earlier report on influenza vaccine use in 18 developed countries. Five of the six countries with high levels of vaccine use in 1992 (> or = 130 doses/1000 population) showed little change or slight declines over the subsequent 3 years. The exception was the United States, where a new federal program for vaccination reimbursement for the elderly helped to increase vaccine distribution from 144 to 239 doses/1000 population. The six countries with medium levels of vaccine use in 1992 (76-96 doses/1000 population) increased to > or = 100 doses/1000 population by 1995. Among the six low-use countries in 1992 (< or = 65 doses/1000 population), only Finland showed substantial improvement (96 doses/1000 population) in 1995. Four new countries were added to the study. In Germany, vaccine use increased to 80 doses/1000 population in 1995, but in Ireland it remained at a low level (48 doses/1000 population). In Korea, vaccine use increased from 17 to 95 doses/ 1000 population during the period 1987-1995. In Japan, very high levels of vaccine use (approximately 280 doses/1000 population) in the early 1980s were associated with vaccination programs for school children. However, vaccine use fell precipitously when these programs were discontinued, and only 2 and 8 doses/1000 population were used in 1994 and 1995, respectively. In all 22 countries, higher levels of vaccine use were associated with vaccination reimbursement programs under national or social health insurance and were not correlated with different levels of economic development. Excluding Japan, in 1995 there was still a greater than fourfold difference between the highest and lowest levels of vaccine use among the other 21 countries in the study. Given its well established clinical effectiveness and cost-effectiveness, none of these countries has yet achieved the full benefits of its programs for influenza vaccination.

Detection of antibodies to melanocytes in vitiligo by western immunoblotting

To more fully define the nature of the antibody response to melanocytes which is associated with vitiligo, a Western immunoblot assay was used to test the sera of 28 patients with vitiligo (21 with active non-segmental, and 7 with stable segmental diseases) and 26 normal individuals for antibodies to antigens in detergent extracts of melanocyte membrane fractions. Antibodies to melanocytes were found in 26 (93%) of the patients with vitiligo, and in 16 (62%) of the control individuals. Patients with vitiligo and control individuals both had antibodies to an 80 approximately 83 kD antigen. The patient with vitiligo, in addition, had antibody responses to antigens with MWs of 45, 65, and 110 kD. Antibodies to these antigens were present in 46, 25, and 31% of vitiligo patients, but in only 19%. 0%, amd 0%, respectively, of the normal individuals. The heterogeneity of the antibody responses to melanocytes in vitiligo was further confirmed by the presence of antibodies to at least 3 distinct antigens in one-third of vitiligo patients but in none of the normal individuals. There was no difference in antibody response between patients with generalized and segmental vitiligo, suggesting that the pathogenesis of diseases was similar in both cases.

The water-soluble extract of chicory reduces glucose uptake from the perfused jejunum in rats

Among the components of dietary fiber, the soluble fibers have been found to impair glucose absorption. Little is known, however, about the mechanism of this effect. The direct action of soluble fibers (chicory water-soluble extract and inulin) on the intestinal absorption of glucose was investigated in gutperfused rats. After equilibrium, both jejunal and ileal segments were simultaneously perfused with an isotonic electrolyte solution (pH 7.4) containing glucose (10 mmol/L) and chicory water-soluble extract (chicory extract) or inulin (10 g/L). Each test or control solution was perfused in random sequence, with perfusion times of 30 min. Chicory extract or inulin in the perfusate (10 g/L) inhibited the absorption of glucose from jejunum (P < 0.05). The observed changes in glucose and water absorption caused by chicory extract or inulin were reversible after switching to a fiberfree perfusate. Additionally, net water absorption changed to secretion upon addition of chicory extract or inulin. These results suggest that the reduction in intestinal absorption of glucose observed after perfusion of chicory extract or inulin may be caused by viscosity-related increases in mucosal unstirred layer thickness.

Two vivax malaria cases detected in Korea

On June and July 1994, two cases of vivax malaria were consecutively diagnosed at the Yongsan Hospital, Chung-Ang University in Seoul. The first patient was a soldier serving in western parts of the demilitarized zone (DMZ) while the second case was a resident of a village near DMZ. Neither patients had history of being abroad. Republic of Korea (ROK) has been free of malaria since the mid-1970s except for imported cases. The two vivax malaria cases, together with an additional patient detected in 1993, occurred in relatively small areas near DMZ. This necessitated an epidemiologic surveillance. When medical records and blood smears in the areas were examined, no other cases were found. Of 7,723 mosquitoes collected by a black light trap for two nights in June, 7,066 (91.5%) were Anopheles sinensis. In order to evaluate a significance of the recent malaria occurrence, a surveillance system should be operated in the areas.

Effect of heating rate on palatability and associated properties of pre- and postrigor muscle

Precooked, uncured meat is not widely available to consumers, partially because of associated palatability problems and lack of published information on heat uptake under different industrial conditions. The objectives of this study were to determine the tenderness, extent of lipid oxidation, and total cooking losses in pre- and posterior beef and pork roasts heated at different rates. The muscles were cooked in stainless-steel, perforated heating chambers at oven temperatures of 150, 200, or 250 degrees C and the temperature rise during and after heating was monitored with a digital temperature recorder. Samples were vacuum-packaged, frozen at -20 degrees C for 45 d, thawed at 4 degrees C for 24 h, and reheated in 60 degrees C water for 1 h. Cooking losses, Warner-Bratzler shear force values, thiobarbituric acid values, and pH were determined. The results provide heating curves for pre- and postrigor beef and pork roasts at three oven temperatures. Prerigor samples of both species were less tender than postrigor samples (P < .05). Cooking losses were generally low in prerigor samples of both species compared with postrigor samples (P < .05). All beef samples had relatively low thiobarbituric acid (TBA) values before and after storage, whereas pork samples had relatively high TBA values before and after storage. Results indicate that prerigor cooked roasts shrink less, are equivalent or better in oxidative stability, and are less tender than postrigor cooked roasts under the conditions of this experiment.

The effect of dilution, pH and ionic strength of plasma on t-PA precipitation in euglobulin fraction

In order to evaluate the influence of dilution, pH and ionic strength on the precipitation of t-PA and PAI-1 during euglobulin precipitation, we measured t-PA Ag, PAI-1 Ag and fibrinolytic activity in the euglobulin fraction made of pooled plasma from liver cirrhosis patients, under various conditions by changing pH, ionic strength and degree of dilution. The precipitation of t-PA Ag in the euglobulin fraction was enhanced by decreasing the ionic strength and greatest at pH 6.0. The fibrinolytic activity in the euglobulin fraction showed consistent changes with t-PA Ag under varying pH and ionic strength. The precipitation of t-PA Ag was not influenced by the dilution factor but the larger the dilution factor, the greater the PAI-1 and the smaller the fibrinolytic activity in the euglobulin fraction. PAI Ag in euglobulin fraction showed consistent changes with t-PA Ag in the euglobulin fraction regardless of the changes in ionic strength and pH. The amount of precipitation of t-PA and PAI-1 was increased by the presence of dextran sulfate, under varying pH, ionic strength and dilution conditions. Our results show that the currently used conditions for standard euglobulin precipitation are the most favorable for t-PA precipitation into the euglobulin fraction. The fibrinolytic activity exerted in the euglobulin fraction seems to depend on the amount of t-PA-PAI-1 complex rather than minimized protease inhibitor in the euglobulin fraction.

A case of methimazole-induced acute hepatic failure in a patient with chronic hepatitis B carrier

We report a case of methimazole-induced acute hepatic failure, which occurred 17 weeks after initiation of the drug in a 43-year-old man with hyperthyroidism and hepatitis B surface antigenemia. Postmortem needle autopsy of the liver revealed an established micronodular cirrhosis secondary to hepatitis B with moderate septal/portal inflammation, marked cholestasis and scattered acidophilic bodies. The serum hepatitis B surface antigen (HBsAg) was positive, but reactivation of hepatitis B was unlikely in view of the absence of a serum hepatitis B e antigen (HBeAg) and hepatitis B virus deoxyribonucleic acid (HBV-DNA) and negative stain for HBsAg and hepatitis B core antigen (HBcAg) in the liver tissue.