Orbital-flop transition of superfluid 3He in anisotropic silica aerogel

Superfluid 3He is a paradigm for odd-parity Cooper pairing, ranging from neutron stars to uranium-based superconducting compounds. Recently it has been shown that 3He, imbibed in anisotropic silica aerogel with either positive or negative strain, preferentially selects either the chiral A-phase or the time-reversal-symmetric B-phase. This control over basic order parameter symmetry provides a useful model for understanding imperfect unconventional superconductors. For both phases, the orbital quantization axis is fixed by the direction of strain. Unexpectedly, at a specific temperature Tx, the orbital axis flops by 90∘, but in reverse order for A and B-phases. Aided by diffusion limited cluster aggregation simulations of anisotropic aerogel and small angle X-ray measurements, we are able to classify these aerogels as either "planar" and "nematic" concluding that the orbital-flop is caused by competition between short and long range structures in these aerogels.

Genetic population structure of the Vietnamese ginseng (Panax vietnamensis Ha et Grushv.) detected by microsatellite analysis

Abstract Panax vietnamensis Ha et Grushv. is a precious medicinal species native to the tropical forests of Vietnam. Due to habitat loss and over-harvesting, this species is endangered in Vietnam. To conserve the species, we investigated genetic variability and population structure using nine microsatellites for 148 individuals from seven populations across the current distribution range of P. vietnamensis in Vietnam. We determined a moderate genetic diversity within populations (HO = 0.367, HE = 0.437) and relatively low population differentiation (the Weir and Cockerham index of 0.172 and the Hedrick index of 0.254) and showed significant differentiation (P < 0.05), which suggested fragmented habitats, over-utilization and over-harvesting of P. vietnamensis. Different clustering methods revealed that individuals were grouped into two major clusters, which were associated with gene flow across the geographical range of P. vietnamensis. This study also detected that ginseng populations can have undergone a recent bottleneck. We recommend measures in future P. vietnamensis conservation and breeding programs.

The value of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, red cell distribution width, and their combination in predicting acute pancreatitis severity

OBJECTIVE

Acute pancreatitis is one of the most common causes of acute abdominal pain requiring hospitalization worldwide. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and red blood cell distribution width (RDW) are novel inflammatory markers that have been investigated in various diseases associated with an inflammatory response, achieving many positive results. Evaluating the NLR, PLR, RDW, and their combination to predict acute pancreatitis severity can help clinicians have an appropriate initial treatment strategy.

PATIENTS AND METHODS

This prospective cohort study enrolled 131 patients diagnosed with acute pancreatitis at Gia Dinh Hospital, Ho Chi Minh City, between December 2021 and August 2022. Patients with the following features were excluded from our study: age < 18 years old, time from symptom onset to admission of > 72 hours; patients with autoimmune disease, decompensated cirrhosis, active tuberculosis, heart failure (New York Heart Association class 4), end-stage renal failure, pregnancy, active severe acute respiratory syndrome coronavirus 2 infection, and chronic pancreatitis.

RESULTS

There were 21 severe acute pancreatitis (SAP) cases (16%). The area under the receiver operating characteristic curve for predicting SAP was 0.82 for NLR, 0.72 for PLR, and 0.73 for RDW. When the cutoffs of 13.5 for NLR, 202.7 for PLR, and 13.1% for the RDW were used, the negative predictive values in predicting SAP were 93.1%, 91.9%, and 98.8%, respectively. This finding demonstrates the value of inflammatory markers in predicting SAP. The combination of these markers did not show an advantage in predicting SAP compared to the single markers.

CONCLUSIONS

High NLR, PLR, and RDW are associated with SAP. These indices are good indicators for predicting SAP. In our study, the combination of inflammatory markers did not improve SAP prediction compared to the individual markers.

Magnetic Susceptibility of Andreev Bound States in Superfluid ^{3}He-B

Nuclear magnetic resonance measurements of the magnetic susceptibility of superfluid ^{3}He imbibed in anisotropic aerogel reveal anomalous behavior at low temperatures. Although the frequency shift clearly identifies a low-temperature phase as the B phase, the magnetic susceptibility does not display the expected decrease associated with the formation of the opposite-spin Cooper pairs. This susceptibility anomaly appears to be the predicted high-field behavior corresponding to the Ising-like magnetic character of surface Andreev bound states within the planar aerogel structures.

Diagnostic performance of MRI perfusion and spectroscopy for brainstem glioma grading

OBJECTIVE

This study investigated the roles of dynamic susceptibility contrast (DSC) perfusion and multivoxel magnetic resonance spectroscopy (MRS) in grading brainstem glioma (BSG).

PATIENTS AND METHODS

Our retrospective study comprised 12 patients, including 6 with pathology verified low-grade BSGs and 6 with high-grade BSGs. We examined differences in age, relative cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and the metabolite ratios of choline (Cho)/N-acetyl aspartate (NAA) and Cho/creatine (Cr) between these two groups using the Mann-Whitney U test and Chi-square test. Receiver operating characteristic (ROC) curve analysis was used to establish cutoff values and assess their usefulness in grading BSG.

RESULTS

The Cho/NAA metabolite ratio had the strongest preoperative predictive performance for identifying the correct histological grade among BSGs, with an area under the ROC curve (AUC) value of 0.944 (cutoff: 3.88, sensitivity [Se]: 83.3%; specificity [Sp]: 100%), followed by the Cho/Cr ratio (cutoff: 3.08; AUC: 0.917; Se: 83.3%; Sp: 100%), rCBF (cutoff: 3.56, AUC: 0.917; Se: 83.3%; Sp: 100%), rCBV (cutoff: 3.16, AUC: 0.889; Se: 100%; Sp: 66.7%), and age (cutoff: 9.5 years, AUC: 0.889; Se: 100%; Sp: 83.3%).

CONCLUSIONS

rCBF and rCBV values comparing solid tumors with the normal brain parenchyma and the metabolite ratios for Cho/NAA and Cho/Cre may serve as useful indices for establishing BSG grading and provide important information when determining treatment planning and prognosis in patients with BSG.

Preoperative ultrasonography and magnetic resonance imaging evaluation of the position of the neurovascular bundle for Dupuytren's disease of the fifth digit

Background

Dupuytren's contracture (DC) is a fibrosing disor-der that produces pathological subcutaneous nodules and cords in the normal fascia. The isolated occurrence of Dupuytren's disease of the fifth digit is uncommon. This study is aimed to describe the imaging features of an isolated digital cord of the small finger and its relationship with the neurovascular bundle.

Methods

A total of 13 hands in 13 patients who were clinically diagnosed with an isolated occurrence of Dupuytren's disease of the small finger were included between October 2008 and October 2013. Two independent radiologists used ultrasound and magnetic reso-nance imaging (MRI) to record size, signal or echogenicity, contrast enhancement or hyperemia, calcification, and anatomical features of the cord and its relationship with the neurovascular bundle.

Results

We found that ultrasound and MRI were accurate for the detection of the cords and neurovascular bundles in the small finger. The intermodality agreement between MRI and ultrasound was 100% for the detection of 6 spiraling bundles containing 13 isolated cords (46.2%). Among the subjects examined, 100% of the hands had ab-ductor digiti minimi (ADM) area involvement, and the distal insertion of the cord was on the ulnar side of the base of the middle phalanx. On MRI, all of the cords showed predominantly low signal intensity on both T1- and T2-weighted images. On ultrasound, the ulnar cord showed a hyperechoic or isoechoic appearance in 69.3% of hands and a hypoechoic appearance in 30.7% of hands.

Conclusions

The spiraling of the bundle in the isolated occurrence of Dupuytren's disease at the small finger is a frequent occurrence. MRI and ultrasound are good imaging modalities for the evaluation of the relationship between the neurovascular bundle and the isolated cord.

Effect of Magnetic Impurities on Superfluid ^{3}He

It is known that both magnetic and nonmagnetic impurities suppress unconventional superconductivity. Here we compare their effect on the paradigm unconventional superconductor, superfluid ^{3}He, using highly dilute silica aerogel. Switching magnetic to nonmagnetic scattering in the same physical system is achieved by coating the aerogel surface with ^{4}He. We find a marginal influence on the transition temperature itself. However, we have discovered that the A phase, which breaks time reversal symmetry, is strongly influenced, while the isotropic B phase is unchanged. Importantly, this occurs only if the impurities are anisotropically distributed on a global scale.

Orbital-Flop Transition of Angular Momentum in a Topological Superfluid

The direction of the orbital angular momentum of the B phase of superfluid ^{3}He can be controlled by engineering the anisotropy of the silica aerogel framework within which it is imbibed. In this work, we report our discovery of an unusual and abrupt "orbital-flop" transition of the superfluid angular momentum between orientations perpendicular and parallel to the anisotropy axis. The transition has no hysteresis, warming or cooling, as expected for a continuous thermodynamic transition, and is not the result of a competition between strain and magnetic field. This demonstrates the spontaneous reorientation of the order parameter of an unconventional BCS condensate.

Activated RHOA and peripheral axon regeneration

The regeneration of adult peripheral neurons after transection is slow, incomplete and encumbered by severe barriers to proper regrowth. The role of RHOA GTPase has not been examined in this context. We examined the expression, activity and functional role of RHOA GTPase and its ROK effector, inhibitors of regeneration, during peripheral axon outgrowth. We used qRT-PCR, quantitative immunohistochemistry, and assays of RHOA activation to examine expression in sensory neurons of rats with sciatic transection injuries. In vitro, we exposed dissociated adult sensory neurons, not grown on inhibitory substrates, to a RHOA-ROK inhibitor HA-1077 and measured neurite initiation and outgrowth. In vivo, we exposed early regenerating axons and Schwann cells directly to HA-1077 in a conduit connecting the proximal and distal stumps of transected sciatic nerves. Intact adult dorsal root ganglia sensory neurons expressed RHOA and ROK 1 mRNAs and protein and there were rises in RHOA after injury. Activated GTP-bound RHOA, undetectable in intact ganglia, was dramatically upregulated in both neurons and axons after injury. Adult rat sensory neurons in vitro demonstrated a dose-related increase in the initiation of neurite outgrowth, and in the proportion with long neurites when they were exposed to a ROK antagonist. Regenerative bridges that were directly exposed to the ROK inhibitor had a dose-related rise in the extent and distance of in vivo axon and partnered Schwann cell regrowth within them. RHOA activation and signaling are features of adult peripheral axon regeneration within its own milieu, independent of myelin. Inhibition of its activation may benefit peripheral axon lesions.

Wild-type nonneuronal cells extend survival of SOD1 mutant motor neurons in ALS mice

The most common inherited [correct] form of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease affecting adult motor neurons, is caused by dominant mutations in the ubiquitously expressed Cu-Zn superoxide dismutase (SOD1). In chimeric mice that are mixtures of normal and SOD1 mutant-expressing cells, toxicity to motor neurons is shown to require damage from mutant SOD1 acting within nonneuronal cells. Normal motor neurons in SOD1 mutant chimeras develop aspects of ALS pathology. Most important, nonneuronal cells that do not express mutant SOD1 delay degeneration and significantly extend survival of mutant-expressing motor neurons.

Altered levels and distribution of microtubule-associated proteins before disease onset in a mouse model of amyotrophic lateral sclerosis

Alterations of the axonal transport and microtubule network are potential causes of motor neurodegeneration in mice expressing a mutant form of the superoxide dismutase 1 (SOD1G37R) linked to amyotrophic lateral sclerosis (ALS). In the present study, we investigated the biology of microtubule-associated proteins (MAPs), responsible for the formation and stabilization of microtubules, in SOD1G37R mice. Our results show that the protein levels of MAP2, MAP1A, tau 100 kDa and tau 68 kDa species decrease significantly as early as 5 months before onset of symptoms in the spinal cord of SOD1G37R mice, whereas decrease in levels of tau 52-55 kDa species is most often noted with the manifestation of the clinical symptoms. Interestingly, there was no change in the protein levels of MAPs in the brain of SOD1G37R mice, a CNS organ spared by the mutant SOD1 toxicity. Remarkably, as early as 5 months before disease onset, the binding affinities of MAP1A, MAP2 and tau isoforms to the cytoskeleton decreased in spinal cord of SOD1G37R mice. This change correlated with a hyperphosphorylation of the soluble tau 52-55 kDa species at epitopes recognized by the antibodies AT8 and PHF-1. Finally, a shift in the distribution of MAP2 from the cytosol to the membrane is detected in SOD1G37R mice at the same stage. Thus, alterations in the integrity of microtubules are early events of the neurodegenerative processes in SOD1G37R mice.

Cycling at the interface between neurodevelopment and neurodegeneration

The discovery of cell cycle regulators has directed cell research into uncharted territory. In dividing cells, cell cycle-associated protein kinases, which are referred to as cyclin-dependent-kinases (Cdks), regulate proliferation, differentiation, senescence and apoptosis. In contrast, all Cdks in post-mitotic neurons, with the notable exception of Cdk5, are silenced. Surprisingly, misregulation of Cdks occurs in neurons in a wide diversity of neurological disorders, including Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Ectopic expression of these proteins in neurons potently induces cell death with hallmarks of apoptosis. Deregulation of the unique, cell cycle-unrelated Cdk5 by its truncated co-activator, p25 and p29, contributes to neurodegeneration by altering the phosphorylation state of non-membrane-associated proteins and possibly through the induction of cell cycle proteins. On the other hand, cycling Cdks such as Cdk2, Cdk4 and Cdk6, initiate death pathways by derepressing E2F-1/Rb-dependent transcription at the neuronal G1/S checkpoint. Thus, Cdk5 and cycling Cdks may have little in common in the healthy CNS, but they likely conspire in leading neurons to their demise.

Reduced number of unmyelinated sensory axons in peripherin null mice

Peripherin is a type III intermediate filament (IF) abundantly expressed in developing neurons, but in the adult, it is primarily found in neurons extending to the peripheral nervous system. It has been suggested that peripherin may play a role in axonal elongation and/or cytoskeletal stabilization during development and regeneration. To further clarify the function of peripherin, we generated and characterized mice with a targeted disruption of the peripherin gene. The peripherin null mice were viable, reproduced normally and did not exhibit overt phenotypes. Microscopic analysis revealed no gross morphological defects in the ventral and dorsal roots, spinal cord, retina and gut, but protein analyses showed increased levels of the type IV IF alpha-internexin in ventral roots of peripherin null mice. Whereas the number and caliber of myelinated motor and sensory axons in the L5 roots remained unchanged in peripherin knockout mice, there was a substantial reduction ( approximately 34%) in the number of L5 unmyelinated sensory fibers that correlated with a decreased binding of the lectin IB4. These results demonstrate a requirement of peripherin for the proper development of a subset of sensory neurons.

Induction of proinflammatory molecules in mice with amyotrophic lateral sclerosis: no requirement for proapoptotic interleukin-1beta in neurodegeneration

Recent studies have demonstrated the activation of caspase-1 and caspase-3 in mice expressing mutant superoxide dismutase 1 (SOD1), models of amyotrophic lateral sclerosis. Caspase-1 converts the prointerleukin-1beta into a potent proinflammatory molecule involved in the innate immune response and in neurodegenerative diseases. We report on the chronic expression of interleukin-1beta mRNA in the spinal cord of SOD1G37R mice, together with robust mRNA expression for the nuclear factor-kappaB (NF-kappaB) inhibitor IkappaBalpha, for other proinflammatory cytokines and chemokines (interleukin-6, tumor necrosis factor-alpha, monocyte chemoattractant protein-1) and for the toll-like receptor TLR2 involved in innate immunity. To further assess the interleukin-1beta contribution to neurodegeneration, we generated mice expressing SOD1G37R in a context of interleukin-1beta gene knockout. Surprisingly, the absence of interleukin-1beta had no effect on the life span of SOD1G37R mice, nor on the extent of motor axon degeneration at age 7 and 10 months. Whereas neither compensatory induction of the interleukin-1alpha mRNA nor increases in mRNA levels for IkappaBalpha, tumor necrosis factor-alpha and macrophage chemoattractant protein-1 occurred as a result of interleukin-1beta gene disruption, enhanced levels of TLR2 mRNA were detected in SOD1G37R mice lacking interleukin-1beta. We conclude that interleukin-1beta does not directly contribute to motor neuron degeneration in SOD1G37R mice, but it may act as a modulator of the innate immune response.

DNA-based vaccination for the treatment of food allergy

At present, avoidance is the only therapeutic option available for individuals with food allergies. However, studies suggest that DNA-based vaccination might be an effective therapeutic option for the reversal of allergic hypersensitivities, including allergies to foods. Because severe anaphylactic reactions represent a life-threatening risk for individuals with food allergies, we and others have evaluated the effectiveness of DNA-based vaccination for the prevention of anaphylactic hypersensitivity in murine models. Our investigations demonstrated that primary gene and protein/immunostimulatory sequence oligodeoxynucleotide (ISS-ODN) vaccination of subsequently Th2-sensitized mice reduced the risk of death after anaphylactic challenge, significantly. In addition, gene and protein/ISS-ODN vaccination reduced post challenge plasma histamine levels. Analysis of the immune profiles of mice receiving DNA-based vaccines showed that both gene and protein/ISS-ODN vaccination effectively prevented the development of Th2-biased immune profiles after sensitization. In contrast, vaccination with protein alone, the experimental equivalent of the traditional protein-based immunotherapy (IT) reagents used in clinical practice provided no protection from anaphylaxis, nor did it prevent the development of a Th2-biased immune profile after allergen sensitization. These studies justify continued optimism in the potential of DNA-based vaccination for the desensitization of food allergic individuals.

Immunostimulatory DNA-based vaccines elicit multifaceted immune responses against HIV at systemic and mucosal sites

Immunostimulatory DNA sequences (ISS, also known as CpG motifs) are pathogen-associated molecular patterns that are potent stimulators of innate immunity. We tested the ability of ISS to act as an immunostimulatory pathogen-associated molecular pattern in a model HIV vaccine using gp120 envelope protein as the Ag. Mice immunized with gp120 and ISS, or a gp120:ISS conjugate, developed gp120-specific immune responses which included: 1) Ab production; 2) a Th1-biased cytokine response; 3) the secretion of beta-chemokines, which are known to inhibit the use of the CCR5 coreceptor by HIV; 4) CTL activity; 5) mucosal immune responses; and 6) CD8 T cell responses that were independent of CD4 T cell help. Based on these results, ISS-based immunization holds promise for the development of an effective preventive and therapeutic HIV vaccine.

Deregulation of Cdk5 in a mouse model of ALS: toxicity alleviated by perikaryal neurofilament inclusions

Recent studies suggest that increased activity of cyclin-dependent kinase 5 (Cdk5) may contribute to neuronal death and cytoskeletal abnormalities in Alzheimer's disease. We report here such deregulation of Cdk5 activity associated with the hyperphosphorylation of tau and neurofilament (NF) proteins in mice expressing a mutant superoxide dismutase (SOD1(G37R)) linked to amyotrophic lateral sclerosis (ALS). A Cdk5 involvement in motor neuron degeneration is supported by our analysis of three SOD1(G37R) mouse lines exhibiting perikaryal inclusions of NF proteins. Our results suggest that perikaryal accumulations of NF proteins in motor neurons may alleviate ALS pathogenesis by acting as a phosphorylation sink for Cdk5 activity, thereby reducing the detrimental hyperphosphorylation of tau and other neuronal substrates.

Noninvasive measurement of microvascular leakage in patients with dengue hemorrhagic fever

Dengue shock syndrome (DSS) is a potentially lethal complication of dengue virus infection associated with hypotension and leakage of plasma water into the extravascular space. To determine whether the underlying pathophysiology of DSS is distinct from that in milder forms of the disease, we assessed microvascular permeability, by use of strain gauge plethysmography, in Vietnamese children with DSS (n=19), or dengue hemorrhagic fever (DHF) without shock (n=16), and in healthy control children (n=15). At admission and after fluid resuscitation, the mean coefficient of microvascular permeability (K(f)) for the patients with dengue was approximately 50% higher than that for the control patients (P=.02). There was no significant difference in K(f) between the 2 groups of patients with dengue; this suggests the same underlying pathophysiology. We hypothesize that in patients with DSS, the fluctuations in K(f) are larger than those in patients with DHF, which leads to short-lived peaks of markedly increased microvascular permeability and consequent hemodynamic shock.

Reduction of axonal caliber does not alleviate motor neuron disease caused by mutant superoxide dismutase 1

It is well established that motor neurons with large axon caliber are selectively affected in amyotrophic lateral sclerosis (ALS). To investigate whether high neurofilament (NF) content and large axonal caliber are factors that predispose motor neurons to selective degeneration in ALS, we generated mice expressing a mutant form of superoxide dismutase 1 (SOD1(G37R)) linked to familial ALS in a context of one allele for each NF gene being disrupted. A approximately 40% decrease of NF protein content detected in triple heterozygous knockout mice shifted the calibers of large axons in L5 ventral root from 5-9 microm to 1-5 microm, altering neither the normal subunit stoichiometry and morphological distribution of NFs nor levels of other cytoskeletal proteins. This considerable reduction in NF burden and caliber of axons did not extend the life span of SOD1(G37R) mice nor did it alleviate the loss of motor axons. Moreover, increasing the density of NFs in axons by overexpressing a NF-L transgene did not accelerate disease in SOD1(G37R) mice. These results do not support the current view that high NF content and large caliber of axons may account for the selective vulnerability of motor neurons in ALS caused by mutant SOD1.

DNA-based vaccination reduces the risk of lethal anaphylactic hypersensitivity in mice

BACKGROUND

Anaphylactic hypersensitivity is the most serious clinical concern facing allergists. However, for the majority of anaphylactic hypersensitivities, avoidance is the only therapeutic option presently available.

OBJECTIVE

This study evaluated the effectiveness of primary gene and protein-immunostimulatory DNA vaccination in the prevention of anaphylactic hypersensitivity in a murine model.

METHODS

Female C3H/HeJ mice were immunized with a plasmid encoding beta-galactosidase (beta-gal) or beta-gal protein plus an immunostimulatory sequence oligodeoxynucleotide. The mice were then T(H2) sensitized to beta-gal by coinjection with alum and pertussis and then intravenously challenged with this model allergen.

RESULTS

Primary gene and protein-immunostimulatory DNA vaccination of subsequently T(H2)-sensitized mice reduced the risk of death after anaphylactic challenge from 100% to 67% and 58%, respectively (P<.018 vs control mice). In addition, gene and protein-immunostimulatory DNA vaccination reduced postchallenge plasma histamine levels by greater than 4-fold (P <.05 vs control mice). Consistent with previous studies, these DNA-based vaccination strategies were further shown to blunt the development of T(H2)-biased immune responses after allergen sensitization. Vaccination with protein alone, the experimental equivalent of a traditional immunotherapy reagent, provided no protection from anaphylaxis nor did it prevent the development of a T(H2)-biased immune profile after allergen sensitization.

CONCLUSION

The present series of experiments demonstrate that both gene vaccination and coimmunization with protein and immunostimulatory DNA are effective in attenuating the development of anaphylactic hypersensitivity in subsequently T(H2) sensitized mice.

Immunostimulatory DNA-based vaccines induce cytotoxic lymphocyte activity by a T-helper cell-independent mechanism

Immunostimulatory DNA sequences (ISS) contain unmethylated CpG dinucleotides within a defined motif. Immunization with ISS-based vaccines has been shown to induce high antigen-specific cytotoxic lymphocyte (CTL) activity and a Th1-biased immune response. We have developed a novel ISS-based vaccine composed of ovalbumin (OVA) chemically conjugated to ISS-oligodeoxynucleotide (ODN). Protein-ISS conjugate (PIC) is more potent in priming CTL activity and Th1-biased immunity than other ISS-based vaccines. Cytotoxic lymphocyte activation by ISS-ODN-based vaccines is preserved in both CD4-/- and MHC class II-/- gene-deficient animals. Furthermore, PIC provides protection against a lethal burden of OVA-expressing tumor cells in a CD8+ cell-dependent manner. These results demonstrate that PIC acts through two unique mechanisms: T-helper-independent activation of CTL and facilitation of exogenous antigen presentation on MHC class I. This technology may have clinical applications in cancer therapy and in stimulating host defense in AIDS and chronic immunosuppression.

Cell type-specific regulation of fibrinogen expression in lung epithelial cells by dexamethasone and interleukin-1beta

Our recent studies demonstrating the expression of fibrinogen (FBG) by an alveolar type II cell line stimulated with proinflammatory mediators and also in the inflamed pulmonary epithelium of animals with Pneumocystis carinii pneumonia suggest that extrahepatic FBG participates in the local acute phase response (APR) to infection and subsequent wound repair. However, the mechanisms that regulate extrahepatic FBG expression are poorly understood. This study compares the regulation of hepatic and pulmonary FBG expression by mediators of the APR, interleukin (IL)-6, IL-1beta, and dexamethasone (DEX), a synthetic glucocorticoid. Northern blotting and metabolic labeling studies revealed that IL-6 with or without DEX upregulates gammaFBG messenger RNA and protein, whereas IL-1beta inhibits gammaFBG expression in human lung (A549) and liver (HepG2) epithelial cells. In contrast, the addition of DEX relieved the IL-1beta-mediated inhibition of FBG expression in lung epithelial cells only; this response is termed "DEX rescue." Studies with cycloheximide indicate that only DEX rescue required de novo protein synthesis. Nuclear run-on analysis revealed no increase in gammaFBG transcription by DEX treatment. Although DEX treatment alone increased the stability of gammaFBG transcripts in lung cells, this effect was not observed in the presence of IL-1beta. Together, these results suggest that pre-existing transcription factors mediate the effects of IL-6 with or without DEX, DEX, and IL-1beta on gammaFBG gene expression in lung and liver cells. Also, the data suggest that DEX induces new protein synthesis of an inhibitor of IL-1beta signal transduction to effectively "rescue" FBG production in lung but not liver epithelial cells. This cell type-specific stimulation of FBG production by glucocorticoids to overcome IL-1beta inhibition may promote pulmonary wound repair mechanisms.

Immunostimulatory DNA pre-priming: a novel approach for prolonged Th1-biased immunity

Immunostimulatory DNA sequences (ISS) have been shown to promote CTL and Th1 immune responses to coinjected antigens. This phenomenon can be attributed to the capacity of ISS to induce the secretion of type-1 cytokines and to up regulate costimulatory ligands on antigen-presenting cells. We hypothesized that ISS administration prior to antigen administration (prepriming), via the mechanisms stated above, would Th1 bias immune responses to subsequently injected antigens for an extended period of time. The data presented show that ISS provide in vivo adjuvant activity for up to 2 weeks after intradermal or intranasal delivery. Furthermore, the results demonstrate that ISS prepriming can induce immune responses that are significantly stronger than with ISS/antigen covaccination. ISS prepriming offers an alternative approach to the traditional use of adjuvants (i.e., antigen/adjuvant coinjection) and expands the potential clinical applications for ISS.

Enhancement of antigen-presenting cell surface molecules involved in cognate interactions by immunostimulatory DNA sequences

Bacterial genomic DNA, plasmid DNA (pDNA) and synthetic oligodeoxynucleotides (ODN) containing immunostimulatory DNA sequences (ISS) have been proposed to foster a Th1 response via the release of type 1 cytokines from macrophages, dendritic cells, NK cells and B cells. In this study, we show that ISS-enriched DNA up-regulates a distinct profile of cell surface molecules on macrophages and B cells in vitro and in vivo. ISS-ODN and ISS-containing pDNA enhanced the expression of antigen presentation molecules (MHC class I and II), co-stimulatory molecules (B7-1, B7-2 and CD40), cytokine receptors (IFN-gamma receptor and IL-2 receptor), an adhesion molecule (ICAM-1) and an Fc receptor (Fcgamma receptor) on murine B cells or bone marrow-derived macrophages. The increased expression of these surface molecules is seen in purified cell populations and is largely independent of the effects of type 1 cytokines. Splenic antigen-presenting cells stimulated with ISS-ODN in vivo efficiently activate naive T cells and bias their differentiation toward a Th1 phenotype in vitro. Thus, the induction of both type 1 cytokines and a distinct profile of cell surface molecules contributes to the potent immunostimulatory effects of ISS-containing DNA on innate and adaptive immunity.

Rapid serologic diagnosis of dengue virus infection using a commercial capture ELISA that distinguishes primary and secondary infections

A commercial capture ELISA for specific IgM and IgG antibodies produced during dengue infection (PanBio Dengue Duo) showed excellent sensitivity (99%, n = 78) using sera collected at hospital discharge compared with established ELISA and hemagglutination inhibition (HAI) assays. Furthermore, the ELISA was able to diagnose 79% of the dengue cases using sera collected at hospital admission. The ELISA also showed high specificity (92%) in paired sera from patients without flavivirus infection (n = 26), although 45% of the patients with Japanese encephalitis (n = 20) showed elevation of IgG but not IgM. The IgG capture ELISA showed good correlation with the HAI assay (r = 0.83, P < 0.0001), and IgG levels could be used to distinguish between primary and secondary infection, with 100% of primary infections and 96% of secondary infections being correctly classified. This ELISA should prove useful in the clinical diagnosis of dengue infections.

Immunostimulatory DNA sequences inhibit IL-5, eosinophilic inflammation, and airway hyperresponsiveness in mice

We have used a mouse model of allergen-induced airway hyperresponsiveness to demonstrate that immunostimulatory DNA sequences (ISS) containing a CpG DNA motif significantly inhibit airway eosinophilia and reduce responsiveness to inhaled methacholine. ISS not only inhibited eosinophilia of the airway (by 93%) and lung parenchyma (91%), but also significantly inhibited blood eosinophilia (86%), suggesting that ISS was exerting a significant effect on the bone marrow production of eosinophils. The inhibition of the bone marrow production of eosinophils by 58% was associated with a significant inhibition of T cell-derived cytokine generation (IL-5, granulocyte-macrophage CSF, and IL-3). ISS exerted this inhibitory effect on T cell cytokine production indirectly by stimulating monocytes/macrophages and NK cells to generate IL-12 and IFNs. The onset of the ISS effect on reducing the number of tissue eosinophils was both immediate (within 1 day of administration) and sustained (lasted 6 days), and was not due to ISS directly inducing eosinophil apoptosis. ISS was effective in inhibiting eosinophilic airway inflammation when administered either systemically (i.p.), or mucosally (i.e., intranasally or intratracheally). Interestingly, a single dose of ISS inhibited airway eosinophilia as effectively as daily injections of corticosteroids for 7 days. Moreover, while both ISS and corticosteroids inhibited IL-5 generation, only ISS was able to induce allergen-specific IFN-gamma production and redirect the immune system toward a Th1 response. Thus, systemic or mucosal administration of ISS before allergen exposure could provide a novel form of active immunotherapy in allergic diseases.

Immunostimulatory DNA is a potent mucosal adjuvant

Most proteins delivered to mucosal surfaces fail to induce mucosal or systemic immune responses. We demonstrate that a single intranasal (i.n.) coadministration of a model antigen (beta-galactosidase, beta-gal) with immunostimulatory sequence oligodeoxynucleotide (ISS-ODN) induces a mucosal IgA response equivalent to that induced by i.n. codelivery of beta-gal with cholera toxin (CT). Furthermore, i.n. and intradermal (i.d.) delivery of the beta-gal/ISS-ODN mix stimulates equivalent Th1-biased systemic immune responses with high-level cytotoxic T lymphocyte (CTL) activity. In contrast, i.n. immunization with beta-gal and CT results in a Th2-biased systemic immune response with poor CTL activity. Our data show that i.n. delivery of ISS-ODN provides effective adjuvant activity for the induction of both mucosal and systemic Th1-biased immune responses. This immunization approach deserves consideration in the development of vaccines against mucosal pathogens.

The p542 gene encodes an autoantigen that cross-reacts with EBNA-1 of the Epstein Barr virus and which may be a heterogeneous nuclear ribonucleoprotein

In infectious mononucleosis (IM), anti-EBNA-1 antibodies are produced which cross-react with multiple normal human proteins. The cross-reactions can be inhibited with synthetic peptides representing the glycine/alanine repeat in EBNA-1, which implies that the cross-reactivity is due to anti-gly/ala antibodies that cross-react with host proteins containing configurations like those in the EBNA-1 repeat. Here we report the isolation of five gene fragments from a Raji B lymphocyte cDNA library encoding peptides reactive with autoantibodies in an IM serum. One of these, p542, encodes a glycine rich 28-mer which constitutes its cross-reactive epitope, as shown elsewhere. By Northern blots, p542 was identifiable in three B lymphocyte lines, a T cell line, and an epithelial cell line. In a search of the GenBank for proteins with sequence similarity to p542, we found a high degree of identity with the mid- and 3' terminal regions of the recently published mouse gene, Raly, which encodes a protein with the structure of a heterogeneous nuclear ribonuclear protein (hnRNP). We confirmed by anchored RT-PCR our presumption that the 5' sequences of p542 also have a high degree of identity with Raly, including presence of RNA binding motifs characteristic of hnRNPs. There was also sequence homology with human hnRNP C2. From these observations and our previous studies, we conclude that the autoantigen for one of the cross-reactive autoantibodies generated during immune responses to the Epstein Barr virus, anti-p542, is probably an hnRNP.

Immunostimulatory DNA sequences function as T helper-1-promoting adjuvants

An adjuvant role for certain short bacterial immunostimulatory DNA sequences (ISSs) has recently been proposed on the basis of their ability to stimulate T helper-1 (Th1) responses in gene-vaccinated animals. We report here that noncoding, ISS-enriched plasmid DNAs or ISS oligonucleotides (ISS-ODNs) potently stimulate immune responses to coadministered antigens. The ISS-DNAs suppress IgE synthesis, but promote IgG and interferon-gamma (IFN-gamma) production. They furthermore initiate the production of IFN-gamma, IFN-alpha, IFN-beta, and interleukins 12 and 18, all of which foster Th1 responses and enhance cell-mediated immunity. Consideration should be given to adding noncoding DNA adjuvants to inactivated or subunit viral vaccines that, by themselves, provide only partial protection from infection.

An Epstein Barr virus-related cross reactive autoimmune response in multiple sclerosis in Norway

In studies of patients in Norway with multiple sclerosis (MS), we have found cross reactive autoantibodies related to the Epstein Barr virus nuclear antigen-1 (EBNA-1). The MS patients had elevated IgG antibody to EBNA-1, as measured by reactivity with a synthetic glycine/alanine peptide, P62, which represents the glycine/alanine repeat in EBNA-1. The mean titer of anti-P62 in patients with acute relapse at the time of assay was significantly higher than in the remaining patients. Patients with remitting/relapsing MS also had elevated autoantibody to a lymphocyte protein, p542, cross reactive with EBNA-1 through a glycine/serine epitope. High titered anti-EBNA-1 antibodies from some MS, as well as from some SLE sera, were shown to cross react with 80-82 kDa and 60 kDa proteins in neuroglial cells.

The possible involvement of GABAA systems in the antinarcotic effect of majonoside-R2, a major constituent of Vietnamese ginseng, in mice

The effect of majonoside-R2 on morphine- and U-50,488H-induced antinociception was examined by the tail-pinch test in mice and compared with that of diazepam. Majonoside-R2 and diazepam inhibited the morphine- and U-50,488H-induced antinociception, and the actions were antagonized by the benzodiazepine receptor antagonist flumazenil and the GABA-gated CI- channel blocker picrotoxin. Diazepam but not majonoside-R2 exhibited a protective activity against convulsion caused by the GABAA antagonists bicuculline and picrotoxin. These results indicate that GABAA systems are involved in the effect of majonoside-R2 on the opioid-induced antinociception and suggest that the mechanisms of action of majonoside-R2 may differ from those of diazepam.

Immunostimulatory DNA sequences necessary for effective intradermal gene immunization

Vaccination with naked DNA elicits cellular and humoral immune responses that have a T helper cell type 1 bias. However, plasmid vectors expressing large amounts of gene product do not necessarily induce immune responses to the encoded antigens. Instead, the immunogenicity of plasmid DNA (pDNA) requires short immunostimulatory DNA sequences (ISS) that contain a CpG dinucleotide in a particular base context. Human monocytes transfected with pDNA or double-stranded oligonucleotides containing the ISS, but not those transfected with ISS-deficient pDNA or oligonucleotides, transcribed large amounts of interferon-alpha, interferon-beta, and interleukin-12. Although ISS are necessary for gene vaccination, they down-regulate gene expression and thus may interfere with gene replacement therapy by inducing proinflammatory cytokines.

Two or three days of ofloxacin treatment for uncomplicated multidrug-resistant typhoid fever in children

An open randomized comparison of 2 days (Ofx2) versus 3 days (Ofx3) of oral ofloxacin treatment (15 mg/kg/day) was conducted with Vietnamese children between 1 and 15 years of age with suspected typhoid fever. Of 108 children enrolled, 100 were blood culture positive for Salmonella typhi, and 86% of the isolates were multidrug resistant. There were no significant adverse effects. The therapeutic responses were similar in both groups, with mean (+/- standard deviation) fever clearances of 107 +/- 60 h in the Ofx3 group and 100 +/- 64 h in the Ofx2 group (P > 0.2). There were six "clinical" failures in the Ofx2 group and two clinical failures in the Ofx3 group (P > 0.2), in which fever and symptoms persisted for more than 1 week after the start of treatment, but only one of these was culture positive (Ofx3). There was one suspected relapse, and one carrier was identified. Short courses of ofloxacin are simple, inexpensive, safe, and effective for the treatment of uncomplicated multidrug-resistant typhoid fever.

Effects of majonoside-R2 on pentobarbital sleep and gastric lesion in psychologically stressed mice

The effects of Vietnamese ginseng (VG) and its major constituent majonoside-R2 on pentobarbital-induced sleep and gastric lesion in psychologically stressed mice were examined. Psychological stress exposure for 30 min significantly decreased the duration of pentobarbital (50 mg/kg, IP)-induced sleep in mice. VG extract (50 mg/kg, PO), VG saponin (25 mg/kg, PO), and majonoside-R2 (3.1-12.5 mg/kg, PO and IP) had no effect on pentobarbital sleep in unstressed control mice, but these drugs significantly recovered pentobarbital sleep decreased by psychological stress to the level of unstressed control animals. On the other hand, Panax ginseng (PG) extract (50-100 mg/kg, PO) failed to affect pentobarbital sleep in psychologically stressed mice. The effect of majonoside-R2 on psychological stress-induced decrease in the hypnotic activity of pentobarbital was significantly blocked by flumazenil (1 mg/kg, IV), a selective benzodiazepine antagonist. Diazepam (0.1 mg/kg, IP) significantly prolonged pentobarbital sleep in unstressed and psychologically stressed groups, and the effect of diazepam was significantly attenuated by the same dose of flumazenil. Naloxone (0.5-5 mg/kg, IP), an opioid antagonist, had no effect on pentobarbital sleep in unstressed or psychologically stressed animals. Psychological stress exposure for 16 h caused gastric lesion in mice. VG extract (25-50 mg/kg, PO) and majonoside-R2 (6.2-12.5 mg/kg, PO), as well as diazepam and naloxone, produced the protective action on gastric lesion in psychologically stressed mice. These results suggest that VG and its major constituent majonoside-R2 have the protective effects on the psychological stress-induced pathophysiological changes and that benzodiazepine receptors are partly implicated in the effects of majonoside-R2.

Crude saponin extracted from Vietnamese ginseng and its major constituent majonoside-R2 attenuate the psychological stress- and foot-shock stress-induced antinociception in mice

Effects of Vietnamese ginseng (VG) crude saponin and majonoside-R2, a major saponin constituent, on the psychological stress- and foot shock stress-induced antinociception in the tail pinch test were examined in mice. VG crude saponin (6.2, 12.5, and 25 mg/kg, P.O.) attenuated psychological stress- but not foot shock stress-induced antinociceptive response, whereas majonoside-R2 (3, 6.2, and 12.5 mg/kg, P.O. and i.p.), as well as naloxone (2 mg/kg, i.p.), suppressed both psychological stress- and foot shock stress-induced antinociception. Pretreatment with the crude saponin (12.5 mg/kg, P.O.) or majonoside-R2 (6.2 mg/kg, P.O.) for 5 days followed by the treatment in combination with stress for next 5 days did not affect the development of adaptation to foot shock stress, but they significantly suppressed the antinociceptive action of the stress measured on the first, second, and third day during the stress exposure period. Majonoside-R2 (6.2 mg/kg, P.O.) but not the crude saponin (12.5 mg/kg, P.O.) significantly blocked the development of adaptation to psychological stress. These results suggest that VG crude saponin has the suppressing effect on psychological stress- and foot shock stress-induced antinociception and that majonoside-R2 is important for the action of the saponin.

The PS-IAA4/5-like family of early auxin-inducible mRNAs in Arabidopsis thaliana

The plant hormone auxin transcriptionally activates early genes. We have isolated a 14-member family of DNA sequences complementary to indoleacetic acid (IAA)-inducible transcripts in Arabidopsis thaliana. The corresponding genes, IAA1 to IAA14, are homologs of PS-IAA4/5 and PS-IAA6 from pea, Aux22 and Aux28 from soybean, ARG3 and ARG4 from mungbean, and AtAux2-11 and AtAux2-27 from Arabidopsis. The members of the family are differentially expressed in mature Arabidopsis plants. Characterization of IAA gene expression in etiolated seedlings demonstrates specificity for auxin inducibility. The response of most family members to IAA is rapid (within 4 to 30 minutes) and insensitive to cycloheximide. Cycloheximide alone induces all the early genes. Auxin-induction of two late genes, IAA7 and IAA8, is inhibited by cycloheximide, indicating requirement of protein synthesis for their activation. All IAA genes display a biphasic dose response that is optimal at 10 microM IAA. However, individual genes respond differentially between 10 nM and 5 microM IAA. Expression of all genes is defective in the Arabidopsis auxin-resistant mutant lines axr1, axr2 and aux1. The encoded polypeptides share four conserved domains, and seven invariant residues in the intervening regions. The spacers vary considerably in length, rendering the calculated molecular mass of IAA proteins to range from 19 kDa to 36 kDa. Overall sequence identity between members of the family is highly variable (36 to 87%). Their most significant structural features are functional nuclear transport signals, and a putative beta alpha alpha-fold whose modeled three dimensional structure appears to be compatible with the prokaryotic beta-ribbon DNA recognition motif. The data suggest that auxin induces in a differential and hierarchical fashion a large family of early genes that encode a structurally diverse class of nuclear proteins. These proteins are proposed to mediate tissue-specific and cell-type restricted responses to the hormone during plant growth and development.

ACS4, a primary indoleacetic acid-responsive gene encoding 1-aminocyclopropane-1-carboxylate synthase in Arabidopsis thaliana. Structural characterization, expression in Escherichia coli, and expression characteristics in response to auxin [corrected]

1-Aminocyclopropane-1-carboxylic acid (ACC) synthase is the key regulatory enzyme in the biosynthetic pathway of the plant hormone ethylene. The enzyme is encoded by a divergent multigene family in Arabidopsis thaliana, comprising at least five genes, ACS1-5 (Liang, X., Abel, S., Keller, J.A., Shen,N. N.F., and Theologis, A. (1992) Poc. Natl. Acad. Sci. U.S.A. 89, 11046-11050). In etiolated seedlings, ACS4 is specifically induced by indoleacetic acid (IAA). The response to IAA is rapid (within 25 min) and insensitive to protein synthesis inhibition, suggesting that the ACS4 gene expression is a primary response to IAA. The ACS4 mRNA accumulation displays a biphasic dose-response curve which is optimal at 10 microM of IAA. However, IAA concentrations as low as 100 microM are sufficient to enhance the basal level of ACS4 mRNA. The expression of ACS4 is defective in the Arabidopsis auxin-resistant mutant lines axr1-12, axr2-1, and aux1-7. ACS4 mRNA levels are severely reduced in axr1-12 and axr2-1 but are only 1.5-fold lower in aux1-7. IAA inducibility is abolished in axr2-1. The ACS4 gene was isolated and structurally characterized. The promoter contains four sequence motifs reminiscent of functionally defined auxin-responsive cis-elements in the early auxin-inducible genes PS-IAA4/5 from pea and GH3 from soybean. Conceptual translation of the coding region predicts a protein with a molecular mass of 53,795 Da and a theoretical isoelectric point of 8.2. The ACS4 polypeptide contains the 11 invariant amino acid residues conserved between aminotransferases and ACC synthases from various plant species. An ACS4 cDNA was generated by reverse transcriptase-polymerase chain reaction, and the authenticity was confirmed by expression of ACC synthase activity in Escherichia coli.

Short course of ofloxacin for treatment of multidrug-resistant typhoid

In recent years, multiresistant strains of Salmonella typhi have emerged in many tropical countries. These strains remain highly sensitive to the fluoroquinolone antibiotics, although use of these drugs by children is considered contraindicated because of their reported toxicity in the cartilage of experimental animals. In a paired, open, randomized study during an epidemic of multidrug-resistant typhoid in southern Vietnam, two short-course ofloxacin regimens (15 mg/kg daily for 3 days and 10 mg/kg daily for 5 days) were compared for the treatment of uncomplicated typhoid fever. Of 438 patients enrolled (of whom 286 were < or = 14 years old), 228 had blood cultures positive for Salmonella species (S. typhi, 207; S. paratyphi A, 19; and S. choleraesuis, 2). There was one treatment failure in a patient who took only one dose of ofloxacin. Otherwise, both regimens were completely effective; there were no proven carriers, and there was no evidence of toxicity, particularly in children. A 3-day course of ofloxacin proved to be safe and highly effective in the treatment of uncomplicated, multidrug-resistant typhoid fever.

Epstein-Barr virus-induced autoimmune responses. II. Immunoglobulin G autoantibodies to mimicking and nonmimicking epitopes. Presence in autoimmune disease

During infectious mononucleosis, IgM autoantibodies are generated to a protein, p542, which contains a glycine-rich 28-mer epitope cross-reactive with the Epstein-Barr nuclear antigen-1 through Epstein-Barr nuclear antigen-1's glycine/alanine repeat. In normal individuals it is uncommon to find IgG anti-p542, but among patients with progressive systemic sclerosis, systemic lupus erythematosus, and ulcerative colitis high IgG anti-p542 (> 3 SD above the mean of normal 20-50 yr controls) occurred frequently. Lesser elevations occurred in Sjögren's syndrome, rheumatoid arthritis, ankylosing spondylitis, and Crohn's disease, but none with chronic hepatitis B infection. The reactive epitopes on p542 were mapped with deletion mutants, which indicated that the glycine-rich 28-mer was the major antigenic determinant, with lesser antibody responses to other epitopes. We conclude that normally there is an inability to generate IgG autoantibodies to the cross-reactive (mimicking) epitope of the p542 host protein, but that this inability is overcome in a proportion of patients with autoimmune disease. We conclude also that non-cross-reactive autoepitopes exist on p542 protein, to which IgG autoantibodies can commonly be formed in autoimmune disorders. The mechanisms responsible for the latter must involve different mechanisms than those responsible for autoantibodies to the mimicking epitope.

Epstein-Barr virus-induced autoimmune responses. I. Immunoglobulin M autoantibodies to proteins mimicking and not mimicking Epstein-Barr virus nuclear antigen-1

In previous studies of infectious mononucleosis, we found IgM autoantibodies which react with hematopoietic cell antigens. Many of these were inhibited by synthetic glycine/alanine peptides representing the glycine/alanine repeat of Epstein-Barr virus nuclear antigen-1. We have cloned and expressed fragments of genes encoding two of these autoantigens. One gene (p542) encodes a protein containing a glycine-rich 28-mer, which is its chief autoantigenic epitope and which represents a newly identified class of evolutionarily conserved autoepitopes. The other gene (p554) encodes a protein that is not demonstrably cross-reactive with Epstein-Barr virus nuclear antigen-1 or with any other EBV protein, but forms complexes with other proteins. Immunoaffinity-purified anti-p542 and anti-p554 have relatively high binding affinities, as evidenced by inhibition at 10(6)-10(8) M-1, and neither autoantibody showed polyreactivity with other common antigens. The data thus suggest that neither autoantibody is simply an expression of polyclonal B cell activation. We conclude that the two autoantigens stimulate autoantibody synthesis by different mechanisms. One autoantigen shares homology to a viral protein which generates cross-reacting antibodies to the autoantigenic epitope. The other has no recognizable cross-reaction with the infecting pathogen and may become immunogenic through complexing with other proteins.

Oleanane and ursane glycosides from Schefflera octophylla

Twelve triterpene glycosides were isolated from the bark of Schefflera octophylla of Vietnamese origin. Three of them were identified as asiaticoside, cauloside D and 3 alpha-hydroxyurs-12-ene-23,28-dioic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside. The structures of nine new glycosides were elucidated by chemical and spectroscopic evidence. Including the known compounds, the 12 glycosides consisted of six pairs of corresponding ursene and oleanene glycosides and all of them had the same triose moiety at the C-28 position. The names scheffurosides A-F and scheffoleosides B-F were proposed for corresponding pairs of ursene and oleanene glycosides, respectively.

Saponins from Vietnamese Ginseng, Panax vietnamensis HA et Grushv. Collected in central Vietnam. II

Further investigation on the saponin composition of rhizomes and roots of Panax vietnamensis HA et GRUSHV. has resulted in the isolation and structural elucidation of seven new dammarane saponins named vina-ginsenosides-R3 (12), -R4 (11), -R5 (16), -R6 (17), -R7 (6), -R8 (20), -R9 (22), together with the identification of six known saponins including 20-gluco-ginsenoside-Rf (10), ginsenoside-Rc (4), notoginsenoside-R6 (9), quinquenoside-R1 (5), gypenoside XVII (2) and majoroside F1 (21). The structures of the novel saponins were established on the basis of chemical and spectral evidence. Vina-ginsenoside-R3 is the first naturally occurring glycoside of dammarenediol II, while vina-ginsenosides-R5 and -R6, two ocotillol-type saponins, are two other examples of saponins having the rare alpha-glucosyl linkage.

Saponins from Vietnamese ginseng, Panax vietnamensis Ha et Grushv. Collected in central Vietnam. I

From rhizomes and roots of Panax vietnamensis Ha et Grushv., Araliaceae, commonly known as Vietnamese Ginseng, two new acetylate saponins named vina-ginsenoside-R1 (13) and vina-ginsenoside-R2 (15) were isolated. On the basis of chemical and spectral data, 13 was formulated as monoacetyl 24(S)-pseudo-ginsenoside-F11 and 15 was proved to be monoacetyl majonside-R2. Besides the two new saponins and beta-sitosteryl-3-O-beta-D-glucopyranoside, sixteen known saponins were also isolated and identified. Dammarane saponins:ginsenoside-Rh1 and 20(R)-ginsenoside-Rh1 (1), ginsenosides-Rg1 (2), -Re (3), -Rd (6), -Rb3 (7), -Rb2 (8), -Rb1 (9), pseudo-ginsenoside-RS1 (= monoacetyl ginsenoside-Re, 4), notoginsenosides-R1 (5) and -Fa (10). Ocotillol-type saponins:pseudo-ginsenoside-RT4 (11), 24(S)-pseudo-ginsenoside-F11 (12), majonosides-R1 (16) and -R2 (14). Oleanolic acid saponins:ginsenoside-Ro (= chikusetsusaponin V, 17) and hemsloside-Ma3 (18), a saponin previously isolated from a cucurbitaceous plant, Hemsleya macrosperma C. Y. Wu. Despite having large horizontally elongated rhizomes, the underground part of this plant contains mainly dammarane saponins and a small amount of oleanolic acid saponins. In addition, the yield of ocotillol-type saponins, especially majonoside-R2, is surprisingly very high (more than 5% and ca. half of the total yield of saponin). This characteristic saponin composition has made Vietnamese Ginseng an interesting species among Panax spp.