山东植物区系中的特有现象

对山东植物区系中的特有现象进行了初步研究。全省共有５３个特有种,可分为４种分布式样即全省布型、鲁中南－山东半岛间断分布型、鲁中南山地分布和山东半岛分布型;提出了山东植物区的两个特有现象中心,即崂山昆嵛山中心和泰山蒙山中心,并初步探讨了其形成原因。     

Heterogeneity of purinergic P2 receptors at the level of the caudal artery of the rat and the saphenous vein of the dog

Phentolamine (10(-5) M) and an inhibitor of the lipoxygenase pathway, nordihydroguaiaretic acid (N. D. G. A.; 8 10(-6) M) antagonized the ATP induced contraction but not antagonized the UTP induced contraction on both rat tail artery and dog saphenous vein. We conclude that the receptors to ATP are distinct from receptors to UTP and that the P2 purinoceptors are an heterogeneous group.     

Comparative morphology of the carpel in the Liliaceae: Uvularieae

Three genera of the Uvularieae (Kreysigia, Schelhammera, Uvularia) have tricarpellate, syncarpous pistils. Ventral bundles (presumably the united simple septal and placental bundles of a carpellary wing) may be present in Kreysigia and Schelhammera. In Kreysigia the two presumptive ventral bundles from adjoining carpels are fused basipetally in each septum. The septal bundles of the other two genera are either simple (Schelhammera) or in part compound (united) below and simple (separate) above (Uvularia) , hence fused acropetally. In Uvularia , the dorsal bundle of the carpel and the median bundle of the tepal are uniquely tripartite and probably homologous. No raphides were found in the carpels of these genera.     

Assessing the lipid requirements of the Torpedo californica nicotinic acetylcholine receptor

The lipid requirements of the Torpedo californica nicotinic acetylcholine receptor (nAChR) were assessed by reconstituting purified receptors into lipid vesicles of defined composition and by using photolabeling with 3-trifluoromethyl-3-(m-[125I]iodophenyl)diazirine ([125I]TID) to determine functionality. Earlier studies demonstrated that nAChRs reconstituted into membranes containing phosphatidylcholine (PC), the anionic lipid phosphatidic acid (PA), and cholesterol (CH) are particularly effective at stabilizing the nAChR in the resting (closed) state that is capable of undergoing agonist-induced conformational transitions (i.e., functionality). The present studies demonstrate that (1) there is no obligatory requirement for PC, (2) increasing the CH content serves to increase the degree to which nAChRs are stabilized in the resting state, and this effect saturates at approximately 35 mol % (molar lipid percentage), and (3) the effect of increasing levels of PA saturates at approximately 12 mol % and in the absence of PA nAChRs are stabilized in the desensitized state (i.e., nonfunctional). Native Torpedo membranes contain approximately 35 mol % CH but less than 1 mol % PA, suggesting that other anionic lipids may substitute for PA. We report that (1) phosphatidylserine (PS) and phosphatidylinositol (PI), anionic lipids that are abundant in native Torpedo membranes, also stabilize the receptor in the resting state although with reduced efficacy (approximately 50-60%) compared to PA, and (2) for nAChRs reconstituted into PA/CH membranes at different lipid-protein molar ratios, receptor functionality decreases rapidly below approximately 65 lipids per receptor. Collectively, these results are consistent with a functional requirement of a single shell of lipids surrounding the nAChR and specific anionic lipid- and sterol (CH)-protein interactions.     

On the origin of rhythmic calcium transients in the ICC-MP of the mouse small intestine

Interstitial cells of Cajal associated with the myenteric plexus (ICC-MP) are pacemaker cells of the small intestine, producing the characteristic omnipresent electrical slow waves, which orchestrate peristaltic motor activity and are associated with rhythmic intracellular calcium oscillations. Our objective was to elucidate the origins of the calcium transients. We hypothesized that calcium oscillations in the ICC-MP are primarily regulated by the sarcoplasmic reticulum (SR) calcium release system. With the use of calcium imaging, study of the effect of T-type calcium channel blocker mibefradil revealed that T-type channels did not play a major role in generating the calcium transients. 2-Aminoethoxydiphenyl borate, an inositol 1,4,5 trisphosphate receptor (IP(3)R) inhibitor, and U73122, a phospholipase C inhibitor, both drastically decreased the frequency of calcium oscillations, suggesting a major role of IP(3) and IP(3)-induced calcium release from the SR. Immunohistochemistry proved the expression of IP(3)R type I (IP(3)R-I), but not type II (IP(3)R-II) and type III (IP(3)R-III) in ICC-MP, indicating the involvement of the IP(3)R-I subtype in calcium release from the SR. Cyclopiazonic acid, a SR/endoplasmic reticulum calcium ATPase pump inhibitor, strongly reduced or abolished calcium oscillations. The Na-Ca exchanger (NCX) in reverse mode is likely involved in refilling the SR because the NCX inhibitor KB-R7943 markedly reduced the frequency of calcium oscillations. Immunohistochemistry revealed 100% colocalization of NCX and c-Kit in ICC-MP. Testing a mitochondrial NCX inhibitor, we were unable to show an essential role for mitochondria in regulating calcium oscillations in the ICC-MP. In summary, ongoing IP(3) synthesis and IP(3)-induced calcium release from the SR, via the IP(3)R-I, are the major drivers of the calcium transients associated with ICC pacemaker activity. This suggests that a biochemical clock intrinsic to ICC determines the pacemaker frequency, which is likely directly linked to kinetics of the IP(3)-activated SR calcium channel and IP(3) metabolism.     

福建中亚热带常绿阔叶林物种多样性的空间格局

对福建中亚热带不同区域、不同海拔梯度的常绿阔叶林群落进行物种多样性测定 ,结果表明 :(1 )在 6个区域中 ,乔木层的物种多样性指数平均值高于灌木层的平均值 ;对丰富度指数 ,太平乔、灌木层 (R1、R2 )最高 ,茂地 (R1、R2 )最低 ;对多样性指数 ,乔木层夏道 (D1、H1)最高 ,土堡 (D1)、茂地 (H1)分别最低 ,灌木层峡阳(D2 )、大洋 (H2 )分别最高 ,太平 (D2 、H2 )最低 ;对均匀度指数 ,乔木层中茂地 (E1、J1)最高 ,土堡 (E1、J1)最低 ,灌木层峡阳 (E2 )、大洋 (J2 )分别最高 ,太平 (E2 、J2 )最低 ;不同区域乔木层的物种多样性指数曲线变化比灌木层缓和 ;(2 )在 6个海拔梯度群落 ,对乔木层物种数和丰富度指数在海拔 2 0 0～ 40 0m(S1、R1)最高 ,对灌木层在海拔 60 0～ 80 0m(S1、R1)最高 ;对乔、灌木层物种数和丰富度指数在海拔 1 0 0 0～ 1 2 0 0m(S1、S2 、R1、R2 )最低 ;对多样性指数 ,在乔木层中在海拔 2 0 0～ 40 0m(D1、H1)最高 ,在海拔 80 0～ 1 0 0 0m(D1、H1)最低 ,在灌木层中在海拔 60 0～ 80 0m(D2 、H2 )最高 ,海拔 80 0～ 1 0 0 0m(D2 、H2 )最低 ;对均匀度指数 ,乔木层中在海拔 10 0 0～ 1 2 0 0m(E1、J1)最高 ,在海拔 80 0～ 1 0 0 0m(E1、J1)最低 ,灌木层中在海拔 1 0 0 0～ 1 2 0 0m(E2 )     

On the head morphology of Grylloblattodea (Insecta) and the systematic position of the order,with a new nomenclature for the head muscles of Dicondylia

External and internal head structures of adults of Galloisiana yuasai (Grylloblattodea) are described. The results are compared with conditions found in representatives of other lower neopteran lineages, notably in Austrophasma and Karoophasma (both Mantophasmatodea). Sutures and ridges of the head capsule are discussed. A new nomenclature for head muscles is presented for the entire Dicondylia (= Zygentoma + Pterygota). Galloisiana (like its sister taxon Grylloblatta) is mostly characterized by plesiomorphic features, such as the largely unspecialized orthopteroid mouthparts, the multisegmented filiform antennae, the presence of trabeculae tentorii, the absence of muscles associated with the antennal ampullae, the presence of musculus stipitalis transversalis (0mx11) and the presence of musculus tentoriofrontalis anterior (0te2). Autapomorphies of Grylloblattodea are: (i) compound eyes composed of only 60 ommatidia or less; (ii) a lacinia with a proximal tooth; (iii) a rounded submentum; (iv) loss of musculus craniohypopharyngealis (0hy3); and (v) loss of musculus labroepipharyngealis (0lb5). The phylogenetic evaluation of 104 characters of the head yields a branching pattern with Grylloblattodea as a sister group of Mantophasmatodea in clade Xenonomia. Putative synapomorphies of both taxa are: (i) a distinct angle (more than 60°) between the submentum and the mentum; (ii) posteriorly oriented labial palpi; (iii) a flat and lobe‐like hypopharynx with a suspensorium far ventrad of the anatomical mouth opening; (iv) loss of musculus tentorioparaglossalis (0la6); and (v) a connection between the antennal ampulla and the supraoesophageal ganglion containing nuclei. Xenonomia is placed in a clade with the two dictyopteran terminals. Another monophyletic group is Embioptera + Phasmatodea. Most branches of the single tree obtained in our analysis are weakly supported. The results clearly show that more data and a much broader taxon sampling are required to clarify the phylogenetic interrelationships of the lower neopteran orders. However, our results narrow down the spectrum of possible solutions, and represent a starting point for future phylogenetic analyses, with an extensive concatenated dataset.     

Global revascularization: the role of the cardiologist

There are compelling reasons for cardiologists to undertake a more global approach to patients with peripheral vascular diseases: atherosclerosis is a 'systemic' disease frequently causing both coronary and peripheral vascular problems in the same patient; coronary artery disease is the most common cause of morbidity and mortality in patients with peripheral vascular disease; and peripheral vascular disease negatively impacts the management of angina pectoris and congestive heart failure. There are four major areas of special interest to the cardiologist: (1) iliac arteries (vascular access), (2) renal arteries (hypertension and volume overload), (3) subclavian arteries (coronary steal with a left internal mammary artery [LIMA] graft), and (4) carotid arteries (stroke). Technical skills necessary to perform coronary angioplasty are transferable to the peripheral vasculature. However, an understanding of the natural history of peripheral disease, patient and lesion selection criteria, and knowledge of other treatment alternatives are essential to performing these procedures safely and effectively. Appropriate preparation and training, and a team approach, including an experienced vascular surgeon, are both desirable and necessary before interventional cardiologists who are inexperienced in the treatment of peripheral vascular disease attempt percutaneous peripheral angioplasty. There are inherent advantages for patients when the cardiologist performing the procedure is also a clinician. Judgments regarding the indications, timing, and risk/benefit ratio of procedures are enhanced by a long-term relationship between physician and patient. Finally, in view of the increased incidence of coronary artery disease in patients with atherosclerotic peripheral vascular disease, the participation of a cardiologist in their care seems appropriate.     

Developmental cytology of the midgut in the flesh-fly, Sarcophaga bullata (Parker)

The cytological comparisons of the midgut in Sarcophaga bullata (Parker) between the second instar, the third instar larvae and the adult are made. The adult midgut differs from that of the larvae in the following ways: (1) the peritrophic membrane is thicker than in the larvae and has become multi-layered; (2) epithelial cells are smaller; (3) branched microvilli are present throughout the entire midgut instead of being present only in the posterior region as in the larval midgut; (4) nuclear pores are less frequent; (5) lysosome-type structures occur less frequently; (6) the basal membrane is thicker; (7) the z-bands in the surrounding muscle fibers are more distinct in adults. The possible function and the significance of these structures related to previous observations in Sarcophaga and other Diptera are discussed.     

Interneuronal organization in the flight system of the locust

In this paper we describe the characteristics, connections, resetting properties and organization of some identified interneurones in the flight system of the locust. The major conclusions are that: (1) the flight rhythm is generated at the interneuronal level and the flight oscillator is not continuously active (2) the interneurones in the flight pattern generator are distributed within at least 6 segmental ganglia (three thoracic and three fused abdominal ganglia) and are not organized into two homologous groups for the separate control of the forewing and the hindwing (3) this distribution of flight interneurones has no obvious functional significance but could be a consequence of flight having evolved from a segmentally distributed motor behaviour (4) there may be a functional hierarchy among flight interneurones such that premotor interneurones are separate from those generating the rhythm.     

Novel Ribonucleic Acid Species Accumulated in the Dark in the Blue-Green Alga Anacystis nidulans

In the dark, the obligately photoautotrophic blue-green alga Anacystis nidulans accumulates large relative amounts of two novel stable ribonucleic acid species (RNAs). These species are also made in illuminated cells but are unstable in them. When darkened cells are reilluminated, these RNAs are rapidly degraded; degradation is inhibited by chloramphenicol. Upon denaturation with heat or urea, one novel species (0.33 x 10(6) daltons) dissociates into two fragments that comigrate with the second novel species (0.16 x 10(6) daltons) on polyacrylamide gels. Both RNAs are associated with particles sedimenting between 30S and 50S through sucrose gradients and are removed from these particles at low magnesium concentration. The function(s) of these RNAs remains unknown.     

Thyroid lysosomes: the stability of the lysosomal membrane

To determine the integrity of lysosomes during their isolation from rat thyroid glands and their subsequent incubation at 37 degrees C, the sedimentability of lysosomal acid phosphatase and thyroglobulin (amount of undisrupted lysosomes) and the latency of sedimentable acid phosphatase (permeability of undisrupted lysosomes) were measured concomitantly. The following results were obtained: (a) During isolation of lysosomes in 0.25 M sucrose medium, mild homogenization of thyroid tissue or cholesterol addition did not modify the amount of undisrupted lysosomes but reduced their permeability. Homogenization in 0.5 M sucrose decreased both the amount and the permeability of undisrupted lysosomes. It also reduced their content of recently iodinated thyroglobulin (Tg). Cholesterol addition had no effect in 0.5 M sucrose medium. (b) During incubations at 37 degrees C of lysosomes, the amount of undisrupted lysosomes decreased progressively while their permeability increased. According to the incubation pH, the permeability of lysosomes prepared in 0.25 M sucrose was either more (pH 8) or less (pH 6) extensively increased than that of lysosomes prepared in 0.5 M sucrose. From these results, we concluded: (a) that isolation and incubation of the thyroid lysosomal fraction induce increased permeability of lysosomes prior to their complete disruption: (b) that recently formed lysosomes (high content of recently iodinated Tg) and aged lysosomes (low content of recently iodinated Tg) differ significantly. Recently formed lysosomes are more permeable, are stabilized by cholesterol and are more extensively disrupted in 0.5 M sucrose medium. During incubations, the permeabilities of these two classes of lysosomes are also differently affected by external pH.     

Role of the promoter in the regulation of the thymidine kinase gene.

To identify the regulatory elements of the human thymidine kinase (TK) gene, we have established stable cell lines carrying different chimeric constructs of the TK gene. Our results can be summarized as follows. (i) When the TK coding sequence is under the control of the calcyclin promoter (a promoter that is activated when G0 cells are stimulated by growth factors), TK mRNA levels are higher in G1-arrested cells than in proliferating cells; (ii) when the TK coding sequence is under the control of the promoter of heat shock protein HSP70, steady-state levels of TK mRNA are highest after heat shock, regardless of the position of the cells in the cell cycle; (iii) the bacterial CAT gene under the control of the human TK promoter is maximally expressed in the S phase; (iv) the TK cDNA driven by the simian virus 40 promoter is also maximally expressed in the S phase; and (v) TK enzyme activity is always at a maximum in the S phase, even when the levels of TK mRNA are highest in nonproliferating cells. We conclude that although the TK coding sequence may also play some role, the TK promoter has an important role in the cell cycle regulation of TK mRNA levels.     

The conservation of the biomass density and the age structure of the populations

A study was made of populations in stationary equilibrium that satisfy the following conditions: (1) The birth rate is very large in relation to the capacity of the habitat. (2) The part of the mortality which is independent of age is easily measured and is found to be very high. For these populations the following conclusions were drawn from the experimental observations: (1) The populations in steady state show an inversely proportional relation between the maximum average age of its components and the mortality. (2) The biomass of a population in a steady state saturating a habitat remains constant in spite of changes in the mortality. (3) The population of organisms continually growing through life, whose steady-state equilibria are reached under conditions of high mortality are composed of great numbers of individuals with a small average size. The equilibria which are reached under conditions of low mortality are characterized by a small number of individuals with large average size.     

Advances in the Taxonomy of Spiders in Miocene Amber from the Dominican Republic (Arthropoda: Araneae)

Trachelas poinari sp. nov. (Corinnidae), Miagrammopes sp. indet. (Uloboridae) and the first indisputable fossil Lycosidae (gen. et sp. indet.) are newly identified and described in Miocene amber from the Dominican Republic. The following are junior synonyms: Nops segmentatus Wunderlich, 1988 of N. lobatus Wunderlich, 1988 (Caponiidae); Azilia muellenmeisteri Wunderlich, 1988 of A. hispaniolensis Wunderlich, 1988 (Tetragnathidae); and Lyssomanes galianoae Reiskind, 1989 of L. pristinus Wunderlich, 1986 (Salticidae). The specimens described as Nops sp. (Caponiidae), Selenops beynai Schawaller, 1984, S. sp. 1, and S. sp. 2 (Selenopidae) by Wunderlich (1988) are unrecognizable as distinct species. The following new combinations are presented: gen. indet. clypeatus (Wunderlich, 1988) (= Anelosimus clypeatus ) (Theridiidae); Meioneta bigibber (Wunderlich, 1988) (= Agyneta bigibber ), M. fastigata (Wunderlich, 1988) (= Agyneta fastigata ), M. separata (Wunderlich, 1988) (= Agyneta separata ) (Linyphiidae); Enacrosoma verrucosa (Wunderlich, 1988) (= Cyclosa verrucosa ) (Araneidae); Pseudosparianthis pfeiferi (Wunderlich, 1988) (= Tentabunda pfeiferi ) (Sparassidae). Theridion wunderlichi nom. nov. is proposed as a replacement name for T. ovale Wunderlich, 1988 (nom. preocc.). The previously unknown male of Styposis pholcoides Wunderlich, 1988 (Theridiidae) is described. Additional features of Argyrodes crassipatellaris Wunderlich, 1988 (Theridiidae) are described; this species is transferred from the trigonum to the cancellatus species group. Nine specimens belonging to six previously described species, and six juvenile Selenops sp. (including one exuvium) are newly identified. These are the first fossil records of Trachelas, Enacrosoma and Pseudosparianthis, giving them stratigraphic ranges of 15–20 my; the genera Anelosimus, Cyclosa and Agyneta are unknown in the fossil record.     

13C-NMR studies of the effects of the carcinogen acetylaminofluorene on the conformation of dinucleoside monophosphate

13C-NMR spectra are obtained in aqueous solution of dinucleoside monophosphates (ApG and GpA) and of their adducts formed by the addition of the carcinogen acetylaminofluorene (AAF) to the C8 position of the guanine. The base and sugar carbons of all dimers and adducts are assigned. The task of assigning base and carbohydrate resonances was accomplished using a series of reference compounds. Significant changes in many of the carbon resonances of the adducts are observed suggesting three general conformational changes, namely: (1) chemical shift changes are noted in base carbon atom resonances as a function of temperature and adduct formation which are indicative of stacking effects; (2) large upfield shifts of the furanose C2' resonance of the guanosine-adduct indicate a shift to higher populations of the syn conformation. Other shifts of carbohydrate resonances are indicative of a change in conformation of the carbohydrate itself. (3) Large temperature effects on linewidth of several fluorine and furanose resonances indicate interconversion of various conformers in the dimer adduct.     

Multiple inductive signals are involved in the development of the ctenophore Mnemiopsis leidyi.

Ctenophores possess eight longitudinally arrayed rows of comb plate cilia. Previous intracellular cell lineage analysis has shown that these comb rows are derived from two embryonic lineages, both daughters of the four e(1) micromeres (e(11) and e(12)) and a single daughter of the four m(1) micromeres (the m(12) micromeres). Although isolated e(1) micromeres will spontaneously generate comb plates, cell deletion experiments have shown that no comb plates appear during embryogenesis following the removal of e(1) descendents. Thus, the m(1) lineage requires the inductive interaction of the e(1) lineage to contribute to comb plate formation. Here we show that, although m(12) cells are normally the only m(1) derivatives to contribute to comb plate formation, m(11) cells are capable of generating comb plates in the absence m(12) cells. The reason that m(11) cells do not normally make comb rows may be attributable either to their more remote location relative to critical signaling centers (e.g., e(1) descendants) or to inhibitory signals that may be provided by other nearby cells such as sister cells m(12). In addition, we show that the signals provided by the e(1) lineage are not sufficient for m(1)-derived comb plate formation. Signals provided by endomesodermal progeny of either the E or the M lineages (the 3E or 2M macromeres) are also required.     

NMR characterization of the pH 4 beta-intermediate of the prion protein: the N-terminal half of the protein remains unstructured and retains a high degree of flexibility

Prion diseases are associated with the misfolding of the PrP (prion protein) from a largely alpha-helical isoform to a beta-sheet-rich oligomer. CD has shown that lowering the pH to 4 under mildly denaturing conditions causes recombinant PrP to convert from an alpha-helical protein into one that contains a high proportion of beta-sheet-like conformation. In the present study, we characterize this soluble pH 4 folding intermediate using NMR. (15)N-HSQC (heteronuclear single-quantum correlation) studies with mPrP (mouse PrP)-(23-231) show that a total of 150 dispersed amide signals are resolved in the native form, whereas only 65 amide signals with little chemical shift dispersion are observable in the pH 4 form. Three-dimensional (15)N-HSQC-TOCSY and NOESY spectra indicate that the observable residues are all assigned to amino acids in the N-terminus: residues 23-118. (15)N transverse relaxation measurements indicate that these N-terminal residues are highly flexible with additional fast motions. These observations are confirmed via the use of truncated mPrP-(112-231), which shows only 16 (15)N-HSQC amide peaks at pH 4. The loss of signals from the C-terminus can be attributed to line broadening due to an increase in the molecular size of the oligomer or exchange broadening in a molten-globule state.     

Identification of Oxidized Amino Acid Residues in the Vicinity of the Mn(4)CaO(5) Cluster of Photosystem II: Implications for the Identification of Oxygen Channels within the Photosystem

As a light-driven water-plastoquinone oxidoreductase, Photosystem II produces molecular oxygen as an enzymatic product. Additionally, under a variety of stress conditions, reactive oxygen species are produced at or near the active site for oxygen evolution. In this study, Fourier-transform ion cyclotron resonance mass spectrometry was used to identify oxidized amino acid residues located in several core Photosystem II proteins (D1, D2, CP43, and CP47) isolated from spinach Photosystem II membranes. While the majority of these oxidized residues (81%) are located on the oxygenated solvent-exposed surface of the complex, several residues on the CP43 protein ((354)E, (355)T, (356)M, and (357)R) which are in close proximity (<15 ?) to the Mn(4)CaO(5) active site are also modified. These residues appear to be associated with putative oxygen/reactive oxygen species exit channel(s) in the photosystem. These results are discussed within the context of a number of computational studies which have identified putative oxygen channels within the photosystem.     

The fine structure of the dorsal column nucleus and the nucleus of bischoff of the python (Python reticulatus)

Three types of neuronal perikaryal profiles were identified in the dorsal column nucleus and the nucleus of Bischoff of the python (Python reticulatus). Type I neuronal profiles are large (diameters 12–20 μm) with a deeply indented uncleus. The cisterns of rough endoplasmic reticulum (rER) are mostly randomly dispersed. Axosomatic synapses are few. Type II neuronal profiles (9–11 μm) have a smooth, round, or slightly oval nucleus. Several small stacks of rER are present. Type III neuronal profiles (8–10 μm) have little cytoplasm. The nuclear margin is irregular but not deeply infolded. The rER usually consists of a single long perinuclear ribosome-studded cistern. Two types of astrocytic profiles have been identified. Both types contain abundant filaments. Type I astrocytes are large cells, and the nucleus is very irregular in shape. Type II astrocytes are smaller and are found among the myelinated axons in the dorsal funiculus. Two classes of axon terminals have been identified. One class contains round synaptic vesicles (R profiles) and the other flattened vesicles (F profiles). Some R profiles are small (SR profiles), others are large (LR profiles). Some R profiles also contain a few large, dense-cored vesicles. The R and F profiles establish axodendritic and axoaxonal synapses, some of which are located in the synaptic glomeruli and others in the extraglomerular neuropil. In most of the axoaxonal synapses, the presynaptic element is an F profile and the post synaptic element an LR profile. Occasionally, LR profiles are presynaptic to F profiles. The findings in the python are compared with those of the dorsal column nuclei of the rat, cat, and monkey.