Effects of Polymannuronic Acid on the Intestinal Microbiota in Mice after Long-Term Intragastric Administration.

Polymannuronic acid (PM) is an alginate oligosaccharide derived from brown algae with a characterized structure and excellent biological activities. Herein, mice were given different doses of PM through 30-day-long-term intragastric administration, and the contents of the jejunum, ileum, and colon were analyzed by 16S rRNA gene sequencing technology for microbial diversity, and relevant experiments were verified according to the analysis results so as to comprehensively evaluate the effects of PM on the intestinal flora. The PM (400 mg/kg and 100 mg/kg) could regulate the microflora balance at the phylum level and increase the microflora richness in the jejunum, ileum, and colon of the mice. The PM could induce more strains that are negatively correlated with Escherichia, thereby reducing the relative abundance of Escherichia. Analysis of bacterial function showed that high and low doses of PM could promote lipid metabolism in the bacterial communities. Moreover, the PM could reduce serum total cholesterol and cholesterol ester levels in a concentration-dependent manner. High-dose PM could lead to colonic intestinal inflammation by increasing the relative abundance of multiple bacterial groups in the jejunum, ileum, and colon. Moreover, high-dose PM could increase lipopolysaccharide-binding protein and interleukin-1ß levels. Therefore, the dose of PM plays an important role in its efficacy, and its biological activity is dosedifferent.

Saponins from Panax japonicus improve neuronal mitochondrial injury of aging rats.

CONTEXT: Panax japonicus is the dried rhizome of Panax japonicus C.A. Mey. (Araliaceae). Saponins from Panax japonicus (SPJ) exhibit anti-oxidative and anti-aging effects. OBJECTIVE: We evaluated the neuroprotective effects of SPJ on aging rats. MATERIALS AND METHODS: Sprague-Dawley rats (18-months-old) were randomly divided into aging and SPJ groups (n = 8). Five-month-old rats were taken as the adult control (n = 8). The rats were fed a normal chow diet or the SPJ-containing diet (10 or 30 mg/kg) for 4 months. An in vitro model was established by d-galactose (d-Gal) in the SH-SY5Y cell line and pretreated with SPJ (25 and 50 µg/mL). The neuroprotection of SPJ was evaluated via Nissl staining, flow cytometry, transmission electron microscopy and Western blotting in vivo and in vitro. RESULTS: SPJ improved the neuronal degeneration and mitochondrial morphology that are associated with aging. Meanwhile, SPJ up-regulated the protein levels of mitofusin 2 (Mfn2) and optic atrophy 1 (Opa1) and down-regulated the protein level of dynamin-like protein 1 (Drp1) in the hippocampus of aging rats (p < 0.05 or p < 0.01 vs. 22 M). The in vitro studies also demonstrated that SPJ attenuated d-Gal-induced cell senescence concomitant with the improvement in mitochondrial function; SPJ, also up-regulated the Mfn2 and Opa1 protein levels, whereas the Drp1 protein level (p < 0.05 or p < 0.01 vs. d-Gal group) was down-regulated. DISCUSSION AND CONCLUSIONS: Further research on the elderly population will contribute to the development and utilization of SPJ for the treatment of neurodegenerative disorders.

Overexpression of CsATG3a improves tolerance to nitrogen deficiency and increases nitrogen use efficiency in arabidopsis.

Nitrogen (N) is a major nutrition element for tea plant. However, application of high levels of N negatively causes environmental problems. Therefore, improved N use efficiency (NUE) of tea plant will be highly desirable and crucial for sustainable tea cultivation. Autophagy plays a central role in N recycling and holds potential to improve N utilization, and many AuTophaGy-related genes (ATGs) are involved in the autophagy process. Here, CsATG3a was identified from Camellia sinensis, and the functions involved in N utilization was characterized in arabidopsis (Arabidopsis thaliana). The transcript level of CsATG3a in tea leaves increases with their maturity. Relative to the wild type (WT) arabidopsis, two CsATG3a-overexpressing (CsATG3a-OE) lines exhibited improved vegetative growth, delayed reproductive stage, and upregulated expression of AtATGs (AtATG3, AtATG5 and AtATG8b) in a low N (LN) hydroponic condition. The expression levels of AtNRT1.1, AtNRT2.1, AtNRT2.2, AtAMT1.1 and AtAMT1.3 for N uptake and transport in roots were all significantly higher in CsATG3a-OE lines compared with those in the WT under LN. Meanwhile, the overexpression of CsATG3a in arabidopsis also increased N and dry matter allocation into both rosette leaves and roots under LN. Additionally, compared with WT, improved HI (harvest index), NHI (N harvest index), NUtE (N utilization efficiency) and NUE (N use efficiency) of CsATG3a-OE lines were further confirmed in a low-N soil cultured experiment. Together, these results concluded that CsATG3a is involved in N recycling and enhances tolerance to LN, indicating that CsATG3a holds potential promise to improve NUE in tea plant.

[Research progress on precious Tibetan medicine formula in prevention and treatment of central nervous system diseases].

Precious Tibetan medicine formula is a characteristic type of medicine commonly used in the clinical treatment of central nervous system diseases. Through the summary of modern research on the precious Tibetan medicine formulas such as Ratnasampil, Ershiwuwei Zhenzhu Pills, Ershiwewei Shanhu Pills, and Ruyi Zhenbao Pills, it is found that they have obvious advantages in the treatment of stroke, Alzheimer's disease, epilepsy, angioneurotic headache, and vascular dementia. Modern pharmacological studies have shown that the mechanisms of precious Tibetan medicine formulas in improving central nervous system diseases are that they promote microcirculation of brain tissue, regulate the permeability of the blood-brain barrier, alleviate inflammation, relieve oxidative stress damage, and inhibit nerve cell apoptosis. This review summarizes the clinical and pharmacological studies on precious Tibetan medicine formulas in prevention and treatment of central nervous system diseases, aiming to provide a reference for future in-depth research and innovative discovery of Tibetan medicine against central nervous diseases.

Ludangshen oral liquid for treatment of convalescent COVID-19 patients: a randomized, double-blind, placebo-controlled multicenter trial.

OBJECTIVE: To explore the effect of Ludangshen oral liquid for treatment of convalescent patients with coronavirus disease 2019 (COVID-19) with randomized, double-blind, placebo-controlled multicenter method. METHODS: 200 convalescent COVID-19 patients who had symptoms related to decreased digestive and respiratory function were randomly divided to either receive Ludangshen oral liquid or placebo for 2 weeks. The severity of clinical symptoms including fatigue, anorexia, abdominal distension, loose stools, and shortness of breath were assessed by visual analogue scale and observed at before and after treatment. The improvement and resolution rates of clinical symptoms were evaluated. Full analysis set (FAS) and per-protocol set (PPS) were used for statistical analyses. Adverse events were recorded during the study. RESULTS: 8 patients did not complete the study. After 2 weeks of treatment, both FAS and PPS results showed that patients in Ludangshen group had significantly lower score of fatigue, anorexia, loose stools, and shortness of breath than placebo group (P < 0.05), while there was no significant difference in distention (P > 0.05). The improvement rate of fatigue, anorexia, distension, loose stools and shortness of breath were significantly higher in Ludangshen group (P < 0.05), as well as the resolution rates (P < 0.05) except for shortness of breath (P > 0.05). There were two cases of adverse events, with one nose bleeding in Ludangshen group and one headache in placebo group. CONCLUSION: The study suggested that two weeks of Ludangshen oral liquid treatment may have certain effects for convalescent COVID-19 patients on improving digestive and respiratory symptoms including fatigue, anorexia, loose stools and shortness of breath, which may be one of the choices for management of convalescent COVID-19 patients with digestive and respiratory symptoms.

Protective effects of curcumin against chronic alcohol-induced liver injury in mice through modulating mitochondrial dysfunction and inhibiting endoplasmic reticulum stress.

BACKGROUND: Curcumin is a major active ingredient extracted from powdered dry rhizome of Curcuma longa. In Ayurveda and traditional Chinese medicine, it has been used as a hepatoprotective agent for centuries. However, the underlying mechanisms are not clear. OBJECTIVE: The present study is to investigate the hepatoprotective effects of curcumin in chronic alcohol-induced liver injury and explore its mechanism. DESIGN: Alcohol-exposed Balb/c mice were treated with curcumin (75 and 150 mg/kg) once per day for 8 weeks. Tissue from individual was fixed with formaldehyde for pathological examination. The activities of mitochondrial antioxidant enzymes, Na+/k+-ATPase, Ca2+-ATPase, and Ca2+Mg2+-ATPase, were determined. The level of mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPTP) opening was also determined. The expression of PGC-1α, NRF1, Mn-SOD, GRP78, PERK, IRE1α, nuclear NF-κB, and phosphorylated IκBα was quantified by western blot. The contents of TNF-α, IL-1ß, and IL-6 in the liver were measured using the ELISA method. RESULTS: Curcumin significantly promoted hepatic mitochondrial function by reducing the opening of MPTP, thus increasing the MMP, promoting the activity of Na+/k+-ATPase, Ca2+-ATPase, and Ca2+/Mg2+-ATPase, and attenuating oxidative stress. Curcumin upregulated the expression of PGC-1α, NRF1, and Mn-SOD, and downregulated the expression of GRP78, PERK, and IRE1α in hepatic tissue. Curcumin also attenuated inflammation by inhibiting the IκBα-NF-κB pathway, which reduced the production of TNF, IL-1ß, and IL-6. CONCLUSION: Curcumin attenuates alcohol-induced liver injury via improving mitochondrial function and attenuating endoplasmic reticulum stress and inflammation. This study provides strong evidence for the beneficial effects of curcumin in the treatment of chronic alcohol-induced liver injury.

Effects of the Zhikang capsule on healing of the flap after radical breast cancer surgery.

This study aimed to investigate the effect and mechanism of trauma flap healing promoted by the Zhikang capsule after radical breast cancer surgery. The enrolled breast cancer patients were randomly divided into two groups: treatment and observation. The patients in the treatment group were treated with the Zhikang capsule in addition to the conventional dressing changes, while patients in the observation group underwent only the regular dressing changes. Serum samples of 98 breast cancer patients (with complete clinical data) who underwent modified radical mastectomy were collected and analyzed for expressions of transforming growth factor beta (TGF-ß) and basic fibroblast growth factor (bFGF). The drainage fluid amount and tissue necrosis rate were found to be lower in the treatment group than in the observation group. Moreover, bFGF expression in peripheral blood was higher in the treatment group than in the observation group. However, no significant difference was found between the two groups in the expression of TGF-ß in peripheral blood. In conclusion, Zhikang capsule is effective in promoting flap healing after radical breast cancer surgery, and the increase of bFGF expression in peripheral blood may be the underlying mechanism.

Identification of spliced mRNA isoforms of retinoid X receptor (RXR) in the Oriental freshwater prawn Macrobrachium nipponense.

Retinoid X receptors (RXR) are members of the nuclear receptor family that are conserved from invertebrates to vertebrates, and they play an essential role in regulating reproductive maturation, molting, and embryo development. In this study, five RXR isoforms, named RXRL2 (L, long form), RXRL3, RXRS1 (S, short form), RXRS2, and RXRS3, containing six domains from A to F, were cloned from the prawn Macrobrachium nipponense using 5'- and 3'- rapid amplification of cDNA ends. Differences among their structures were observed not only in the D and E domains but also in the A/B domain, which were previously found in insects but not in crustaceans. This is the first report to show that differences occur in the A/B domain of RXR in crustaceans. RXR expressions were also examined in various tissues including the ovary, testis, muscle, hepatopancreas, heart, gill, stomach, intestine, and cuticle. Expression pattern investigations indicated that the five isoforms were differentially expressed. RXRS3 was only detected in the ovary, and the other RXRs were abundant in the ovary and testis. These data suggested that RXR mediates a series of processes related to reproduction.

Platelet P2Y12 receptors are involved in the haemostatic effect of notoginsenoside Ft1, a saponin isolated from Panax notoginseng.

BACKGROUND AND PURPOSE: Saponins isolated from Panax notoginseng (Burk.) F.H. Chen have been shown to relieve thrombogenesis and facilitate haemostasis. However, it is not known which saponin accounts for this haemostatic effect. Hence, in the present study we aimed to identify which saponins contribute to its haemostatic activity and to elucidate the possible underlying mechanisms. EXPERIMENTAL APPROACH: Platelet aggregation was analysed using a platelet aggregometer. Prothrombin time, activated partial thromboplastin time and thrombin time were measured using a blood coagulation analyser, which was further corroborated with bleeding time and thrombotic assays. The interaction of notoginsenoside Ft1 with the platelet P2Y12 receptor was determined by molecular docking analysis, cytosolic Ca(2+) and cAMP measurements, and phosphorylation of PI3K and Akt assays. KEY RESULTS: Among the saponins examined, Ft1 was the most potent procoagulant and induced dose-dependent platelet aggregation. Ft1 reduced plasma coagulation indexes, decreased tail bleeding time and increased thrombogenesis. Moreover, it potentiated ADP-induced platelet aggregation and increased cytosolic Ca(2+) accumulation, effects that were attenuated by clopidogrel. Molecular docking analysis suggested that Ft1 binds to platelet P2Y12 receptors. The increase in intracellular Ca(2+) evoked by Ft1 in HEK293 cells overexpressing P2Y12 receptors could be blocked by ticagrelor. Ft1 also affected the production of cAMP and increased phosphorylation of PI3K and Akt downstream of P2Y12 signalling pathways. CONCLUSION AND IMPLICATIONS: Ft1 enhanced platelet aggregation by activating a signalling network mediated through P2Y12 receptors. These novel findings may contribute to the effective utilization of this compound in the therapy of haematological disorders.

Repair effects of exogenous SOD on Bacillus subtilis against gamma radiation exposure.

Superoxide dismutase (SOD) is an enzyme that removes free radicals from cells in many organisms. In order to further characterize these repair effects and their mechanism when subjected to radiation, Bacillus subtilis cells were exposed to gamma radiation and the cell survival rate, intracellular SOD activity, and DNA double-strand breakage were investigated. Vegetative cells of B. subtilis were irradiated by (60)Co gamma radiation at varying doses and subsequently exposed to varying levels of exogenous SOD. Standard plate-count, xanthine oxidase, and pulsed-field gel electrophoresis (PFGE) methods were employed to investigate the repair effects. The results showed that the exogenous SOD could significantly improve cell survival rate and intracellular SOD activity after gamma radiation. The cell survival rate was elevated 30-87 times above levels observed in control samples. Adding exogenous SOD into gamma irradiated cells may dramatically increase intracellular SOD activity (p < 0.01), while percentage of DNA release (PR) values may decrease significantly when cells are treated with SOD. The repair effects were observed to vary with the gamma radiation dose and SOD concentration. These findings suggest that exogenous SOD may have the ability to repair vegetative B. subtilis cell damage after irradiated by gamma radiation. DNA strand scission may also be prevented by addition of SOD. This research contributes to better understanding of protection from the effects of free radicals and their mechanisms, an ongoing process in many organisms that involves the cellular response to gamma radiation, which occurs naturally in soil and water, as well as in unusual cases of high-dosage exposure.

[Formulation optimization and drug release in vitro of membrane controlled tablets of puerarin inclusion compound].

OBJECTIVE: To prepare membrane controlled tablets of puerarin sinclusion compound and to investigate the drug release in vitro. METHOD: The single factors affecting drug release in vitro were investigated. Then, uniform design was used to optimize the formulation of controlled osmotic-pump tablets. RESULT: Drug release profiles in vitro were affected obviously by membrane thickness, penetrating agents and porogen. CONCLUSION: Membrane controlled tablets of puerarin inclusion compound were prepared according to the optimal formulation with zero-order kinetics.

[The combined application of scalp and body acupuncture by stages for low limb dysfunction of patients with apoplexy].

OBJECTIVE: To verify the clinical efficacy on the function recovery of lower extremities for patients with cerebral apoplexy by the staging treatment with the combined therapy of the scalp and body acupuncture. METHODS: Ninty-six cases were randomized into an observation group and a control group, 48 cases in each one. The conventional medication and rehabilitation therapy were given in each group. In the observation group, the combined therapy of the scalp acupuncture and the body acupuncture was provided by stages. At the flaccid stage, Futu (ST 32), Xuehai (SP 10), Zusanli (ST 36), etc. were selected. At the spasmodic stage, Huantiao (GB 30), Xuehai (SP 10), Yanglingquan (GB 34), etc. were selected. In combination with the scalp acupuncture the anterior oblique line of vertex-temploral (motor area) on the affected side was selected. In the control group, the acupoints were not selected according to the disease stages and no scalp acupuncture was applied, and the cases were treated with the needling technique as "regaining consciousness" and in light of the principle as "Yangming meridians specialized for Wei syndrome". The treatment lasted continuously for 8 weeks. The modified Fugl-Meyer motor function assessment (FMA) and Barthel index (BI) were used to assess the motor function of the lower extremities and the activities of daily living before and after treatment for the patients in two groups separately. RESULTS: FMA and BI score were all improved apparently after treatment for the patients in two groups (all P < 0.05), and FMA and BI score after treatment in the observation group were all higher than those in the control group (both P < 0.05). In 8 weeks treatment, the walking ability rate in the observation group was higher than that in the control group [56.3% (27/48) vs 35./4% (17/48), P < 0.05]. The walking speed in the observation group was faster than that in the control group (P < 0.05). CONCLUSION: The combined therapy of the scalp and body acupuncture in the staging treatment improves obviously the motor function of the lower extremities and the activities of daily living for the patients with cerebral apoplexy. This therapy recovers as quickly as possible the walking ability and speed for the patients, which is superior to the conventional acupuncture in comparison.

The combined application of scalp and body acupuncture by stages for low limb dysfunction of patients with apoplexy / 中国针灸

<p><b>OBJECTIVE</b>To verify the clinical efficacy on the function recovery of lower extremities for patients with cerebral apoplexy by the staging treatment with the combined therapy of the scalp and body acupuncture.</p><p><b>METHODS</b>Ninty-six cases were randomized into an observation group and a control group, 48 cases in each one. The conventional medication and rehabilitation therapy were given in each group. In the observation group, the combined therapy of the scalp acupuncture and the body acupuncture was provided by stages. At the flaccid stage, Futu (ST 32), Xuehai (SP 10), Zusanli (ST 36), etc. were selected. At the spasmodic stage, Huantiao (GB 30), Xuehai (SP 10), Yanglingquan (GB 34), etc. were selected. In combination with the scalp acupuncture the anterior oblique line of vertex-temploral (motor area) on the affected side was selected. In the control group, the acupoints were not selected according to the disease stages and no scalp acupuncture was applied, and the cases were treated with the needling technique as "regaining consciousness" and in light of the principle as "Yangming meridians specialized for Wei syndrome". The treatment lasted continuously for 8 weeks. The modified Fugl-Meyer motor function assessment (FMA) and Barthel index (BI) were used to assess the motor function of the lower extremities and the activities of daily living before and after treatment for the patients in two groups separately.</p><p><b>RESULTS</b>FMA and BI score were all improved apparently after treatment for the patients in two groups (all P < 0.05), and FMA and BI score after treatment in the observation group were all higher than those in the control group (both P < 0.05). In 8 weeks treatment, the walking ability rate in the observation group was higher than that in the control group [56.3% (27/48) vs 35./4% (17/48), P < 0.05]. The walking speed in the observation group was faster than that in the control group (P < 0.05).</p><p><b>CONCLUSION</b>The combined therapy of the scalp and body acupuncture in the staging treatment improves obviously the motor function of the lower extremities and the activities of daily living for the patients with cerebral apoplexy. This therapy recovers as quickly as possible the walking ability and speed for the patients, which is superior to the conventional acupuncture in comparison.</p>

[Effect of topical dexamethasone treatment on antigen-presenting cells in murine corneas]. / Topische Dexamethason-Therapie. Einfluss auf antigenpräsentierende Zellen in der Hornhaut der Maus.

OBJECTIVE: To determine the influence of dexamethasone treatment on APCs and the time of graft survival of MHC-disparate grafts. METHODS: Flatmounts of the ocular surface prepared with EDTA and tangential frozen sections of the remaining corneal stroma from untreated eyes of normal mice (n=6) and from eyes treated for 7 days with dexamethasone ( n=6) were immunohistologically examined for content of F4/80+ and MHC II+ cells.Furthermore, corneas of C(3)H mice without and with 7-day dexamethasone eye drop treatment (n=8) were grafted into BALB/c mice receiving the same treatment. RESULTS: The number of positive cells within the epithelial flatmounts showed a dramatic reduction in the dexamethasone-pretreated group (p<0.01 compared to the untreated control group). The number of positive cells in the corneal stroma remained unchanged. The grafts of untreated control mice survived 16+/-4 days, the treated grafts 16+/-3 days. CONCLUSIONS: Most investigators assume that normal murine corneas contain no APCs such as macrophages and Langerhans cells. For the first time we were able to detect APCs in flatmounts of the ocular surface and frozen sections of corneal stroma. Our investigations show that, in contrast to the ocular surface, the number of F4/80+ cells in the corneal stroma is not influenced by dexamethasone treatment. Transplantation of corneas containing donor-derived APCs promotes acute rejection (direct pathway of allorecognition).Thus,dexamethasone treatment did not prolong the time of allograft survival.

[Effect of fish oil supplementation on fatty acid composition and neurotransmitters of growing rats].

In order to observe the change of brain fatty acid composition and neurotransmitter by DHA supplementation during the development stage of young rats, pregnant rats were randomly divided into four groups: normal control group (O), low (L), medium (M) and high (H) dose-DHA supplemented groups. The fatty acids composition, the levels of 5-hydroxy-tryptamine (5-HT), dopamine (DA), norepinephrine (NE) and somatostatin (SS) in ceretral cortex and hippocampus of offsprings were measured. The body weight of pregnant rats and offsprings were also observed. The results showed that DHA content of brain homogenate and the levels of 5-HT, DA and SS in hippocampus of experimental young rats were significantly higher than those of the control group. And the body weight of young rats in the three DHA-supplemented groups were retarded in different degree. It was concluded that DHA supplementation changed the fatty acid composition and increased the levels of 5-HT, DA and SS in hippocampus. Proper ratio of n-3 and n-6 fatty acids in dietary supplementation should be considered.

A distinct thermoreceptive subregion of lamina I in nucleus caudalis of the owl monkey.

An immunohistochemically distinct zone was identified in the superficial aspect of trigeminal nucleus caudalis of the New World owl monkey that is not immunoreactive for substance P or serotonin, in stark contrast to the dense staining present in the surrounding laminae I and II. Thionin-stained sections in different planes showed that this is a subregion of lamina I containing clusters of neurons that appear to have pyramidal or polygonal somata. Extracellular microelectrode recordings in this region revealed clusters of thermoreceptive-specific (COLD) cells with nasal or labial receptive fields, whereas nociceptive neurons were found in the adjacent portions of lamina I. Anterograde tracer injections in this region produced trigeminothalamic terminal labeling in the site homologous to the lamina I spino-thalamo-cortical relay nucleus identified previously in the Old World macaque monkey and in humans. Retrograde tracer injections involving this thalamic site, where recordings of trigeminal COLD-like neurons were obtained, produced clusters of retrogradely labeled trigeminothalamic neurons in this immunohistochemically distinct subregion of lamina I, nearly all of which are pyramidal neurons. We conclude that the nocturnal owl monkey has a specialized perinasal thermoreceptive trigeminothalamic sensory pathway that is probably of behavioral significance during olfactory sniffing. In addition, these observations corroborate other findings that have indicated that lamina I COLD cells are pyramidal neurons and are not physiologically modulated by substance P or serotonin, in contrast to nociceptive neurons.

[A study on inhibitory effect of plant growth retardants on earlier bolting of Chinese Angelica].

OBJECTIVE: Seeking chemical ways of controlling the earlier bolting of Chinese Angelica (CA). METHOD: PP333, B9 and MH in different concentrations and combinations were sprayed into the CA leaves in different periods. RESULTS: In leaf proliferating period the spray could inkibit the earlier bolting, shortening the length of the stem foot, increasing the stem diameter and enhancing the leaf chlorophy 11 contents. The quality of CA production was increased as a result of greater root weight and main root volume. In leaf luxuriatino period the spray showed no marked effect. The growth of the plant would be inhibited by any spray in excessive concentrations. CONCLUSION: Leaf spray could control the earlier bolting of CA.

Morphological classes of spinothalamic lamina I neurons in the cat.

We examined the morphology and distribution of retrogradely labeled spinothalamic tract (STT) neurons in lamina I (the marginal zone) of the spinal dorsal horn after large injections of cholera toxin subunit B (CTb) or Fast Blue (FB) into the contralateral thalamus of cats. Based on the shape and orientation of the somata and proximal dendrites in horizontal sections, three distinct cell types were identified: (1) fusiform cells with small, spindle-shaped somata and bipolar, longitudinal dendritic arbors; (2) pyramidal cells with triangular somata and three main dendritic origins with primarily longitudinal arborizations; and (3) multipolar cells with larger, multiangular somata and four or more radiating dendritic arbors directed both longitudinally and mediolaterally. These three morphological types differed significantly in the number of primary dendrites and the size of the somata. Subclasses of multipolar cells were noted. Nearly all cells could be categorized into these three classes consistently in horizontal sections. A small number of cells with transitional shapes or with small, round somata were unclassified. The proportional distributions of these cell types were found to vary over the length of the spinal cord (from the third cervical through the coccygeal segments) in three cats. The overall proportions of cell types were 34% fusiform, 36% pyramidal, 25% multipolar, and 5% unclassified. The proportions of pyramidal and multipolar cells were strikingly higher within the C7-8 and L6-7 segments and lowest in the thoracic segments. In contrast, fusiform cells formed about 20% of the labeled lamina I STT population in the C7-8 and L6-7 segments but more than 60% in thoracic segments. Across all nine cats, the proportions were similar within the cervical (C5-8) and lumbosacral (L5-S1) enlargements, although considerable interanimal variability was noted. These distinct morphological types of lamina I STT cells with differential longitudinal distributions probably have different functional roles. They may correspond to the three main physiological classes of lamina I STT cells.

Fluoride inhibition of yeast enolase: crystal structure of the enolase-Mg(2+)-F(-)-Pi complex at 2.6 A resolution.

Enolase in the presence of its physiological cofactor Mg2+ is inhibited by fluoride and phosphate ions in a strongly cooperative manner (Nowak, T, Maurer, P. Biochemistry 20:6901, 1981). The structure of the quaternary complex yeast enolase-Mg(2+)-F(-)-Pi has been determined by X-ray diffraction and refined to an R = 16.9% for those data with F/sigma (F) > or = 3 to 2.6 A resolution with a good geometry of the model. The movable loops of Pro-35-Ala-45, Val-153-Phe-169, and Asp-255-Asn-266 are in the closed conformation found previously in the precatalytic substrate-enzyme complex. Calculations of molecular electrostatic potential show that this conformation stabilizes binding of negatively charged ligands at the Mg2+ ion more strongly than the open conformation observed in the native enolase. This closed conformation is complementary to the transition state, which also has a negatively charged ion, hydroxide, at Mg2+. The synergism of inhibition by F- and Pi most probably is due to the requirement of Pi for the closed conformation. It is possible that other Mg(2+)-dependent enzymes that have OH- ions bound to the metal ion in the transition state also will be inhibited by fluoride ions.

[Chemical constituents from the bark of Hibiscus syriacus L].

Seven constituents (I-VII) were isolated from the bark of Hibiscus syriacus and identified as nonanedioic acid (I), suberic acid (II), 1-octarcosanol (III), beta-sitosterol (IV), 1,22-docosanediol (V), betulin (VI) and erythrotriol (VII). VII was obtained from the plant for the first time, I, II, III and VI were isolated from Malvaceae plants for the first time.