bluuebunny/crossref_metadata_2025 huggingface dataset:
Stable oxygen isotope composition of plant tissue: a review
Authors: Barbour Margaret M.
Published: February 2007

With the development of rapid measurement techniques, stable oxygen isotope analysis of plant tissue is poised to become an important tool in plant physiological, ecological, paleoclimatic and forensic studies. Recent advances in mechanistic understanding have led to the improvement of process-based models that accurately predict variability in the oxygen isotope composition of plant organic material (δ18Op). δ18Op has been shown to reflect the isotope composition of soil water, evaporative enrichment in transpiring leaves, and isotopic exchange between oxygen atoms in organic molecules and local water in the cells in which organic molecules are formed. This review presents current theoretical models describing the influences on δ18Op, using recently published experimental work to outline strengths and weaknesses in the models. The potential and realised applications of the technique are described.
Organization of β-adrenoceptor signaling compartments by sympathetic innervation of cardiac myocytes
Authors: Shcherbakova Olga G. , Hurt Carl M. , Xiang Yang , Dell'Acqua Mark L. , Zhang Qi , Tsien Richard W. , Kobilka Brian K.
Published: February 2007

The sympathetic nervous system regulates cardiac function through the activation of adrenergic receptors (ARs). β1 and β2ARs are the primary sympathetic receptors in the heart and play different roles in regulating cardiac contractile function and remodeling in response to injury. In this study, we examine the targeting and trafficking of β1 and β2ARs at cardiac sympathetic synapses in vitro. Sympathetic neurons form functional synapses with neonatal cardiac myocytes in culture. The myocyte membrane develops into specialized zones that surround contacting axons and contain accumulations of the scaffold proteins SAP97 and AKAP79/150 but are deficient in caveolin-3. The β1ARs are enriched within these zones, whereas β2ARs are excluded from them after stimulation of neuronal activity. The results indicate that specialized signaling domains are organized in cardiac myocytes at sites of contact with sympathetic neurons and that these domains are likely to play a role in the subtype-specific regulation of cardiac function by β1 and β2ARs in vivo.
DSL ligand endocytosis physically dissociates Notch1 heterodimers before activating proteolysis can occur
Authors: Nichols James T. , Miyamoto Alison , Olsen Samantha L. , D'Souza Brendan , Yao Christine , Weinmaster Gerry
Published: February 2007

Cleavage of Notch by furin is required to generate a mature, cell surface heterodimeric receptor that can be proteolytically activated to release its intracellular domain, which functions in signal transduction. Current models propose that ligand binding to heterodimeric Notch (hNotch) induces a disintegrin and metalloprotease (ADAM) proteolytic release of the Notch extracellular domain (NECD), which is subsequently shed and/or endocytosed by DSL ligand cells. We provide evidence for NECD release and internalization by DSL ligand cells, which, surprisingly, did not require ADAM activity. However, losses in either hNotch formation or ligand endocytosis significantly decreased NECD transfer to DSL ligand cells, as well as signaling in Notch cells. Because endocytosis-defective ligands bind hNotch, but do not dissociate it, additional forces beyond those produced through ligand binding must function to disrupt the intramolecular interactions that keep hNotch intact and inactive. Based on our findings, we propose that mechanical forces generated during DSL ligand endocytosis function to physically dissociate hNotch, and that dissociation is a necessary step in Notch activation.
Complementation between mouse Mfn1 and Mfn2 protects mitochondrial fusion defects caused by CMT2A disease mutations
Authors: Detmer Scott A. , Chan David C.
Published: February 2007

Mfn2, an oligomeric mitochondrial protein important for mitochondrial fusion, is mutated in Charcot-Marie-Tooth disease (CMT) type 2A, a peripheral neuropathy characterized by axonal degeneration. In addition to homooligomeric complexes, Mfn2 also associates with Mfn1, but the functional significance of such heterooligomeric complexes is unknown. Also unknown is why Mfn2 mutations in CMT2A lead to cell type–specific defects given the widespread expression of Mfn2. In this study, we show that homooligomeric complexes formed by many Mfn2 disease mutants are nonfunctional for mitochondrial fusion. However, wild-type Mfn1 complements mutant Mfn2 through the formation of heterooligomeric complexes, including complexes that form in trans between mitochondria. Wild-type Mfn2 cannot complement the disease alleles. Our results highlight the functional importance of Mfn1–Mfn2 heterooligomeric complexes and the close interplay between the two mitofusins in the control of mitochondrial fusion. Furthermore, they suggest that tissues with low Mfn1 expression are vulnerable in CMT2A and that methods to increase Mfn1 expression in the peripheral nervous system would benefit CMT2A patients.
Chlamydomonas reinhardtiihydin is a central pair protein required for flagellar motility
Authors: Lechtreck Karl-Ferdinand , Witman George B.
Published: February 2007

Mutations in Hydin cause hydrocephalus in mice, and HYDIN is a strong candidate for causing hydrocephalus in humans. The gene is conserved in ciliated species, including Chlamydomonas reinhardtii. An antibody raised against C. reinhardtii hydin was specific for an ∼540-kD flagellar protein that is missing from axonemes of strains that lack the central pair (CP). The antibody specifically decorated the C2 microtubule of the CP apparatus. An 80% knock down of hydin resulted in short flagella lacking the C2b projection of the C2 microtubule; the flagella were arrested at the switch points between the effective and recovery strokes. Biochemical analyses revealed that hydin interacts with the CP proteins CPC1 and kinesin-like protein 1 (KLP1). In conclusion, C. reinhardtii hydin is a CP protein required for flagellar motility and probably involved in the CP–radial spoke control pathway that regulates dynein arm activity. Hydrocephalus caused by mutations in hydin likely involves the malfunctioning of cilia because of a defect in the CP.
Hydin seek: finding a function in ciliary motility
Authors: Smith Elizabeth F.
Published: February 2007

One of the most surprising discoveries in cell biology in the past 5–10 years is the number of diverse human diseases that result from defects in ciliary assembly and/or motility, so-called ciliopathies (Badano, J.L., N. Mitsuma, P.L. Beales, and N. Katsanis. 2006. Annu. Rev. Genomics Hum. Genet. 7:125–148). The results presented by Lechtreck and Witman (see p. 473 of this issue) provide yet another example of how work in the model organism Chlamydomonas reinhardtii can reveal important insights into the underlying mechanisms of ciliary assembly/function and the diseases associated with defects in these organelles. By taking advantage of the wide array of experimental approaches C. reinhardtii offers, Lechtreck and Witman determined the precise axonemal location of hydin, a protein that, when mutated, causes hydrocephalus, and defined a unique role for hydin in ciliary motility.
Haptic Display of Constrained Dynamic Systems via Admittance Displays
Authors: Faulring Eric L. , Lynch Kevin M. , Colgate J. Edward , Peshkin Michael A.
Published: February 2007

In the Cobotic Hand Controller, we have introduced an admittance display that can render very high impedances (up to its own structural stiffness). This is due to its use of infinitely variable transmissions. While admittance displays typically excel at rendering high impedances, the incorporation of infinitely variable transmissions in the Cobotic Hand Controller allows the stable display of a wide dynamic range, including low impedances. The existence of a display that excels at rendering high-impedance constraints, but has high-fidelity control of low impedances tangent to those constraints, has led us to describe an admittance control architecture not often examined in the haptics community. In this paper, we develop a comprehensive approach that enables rendering of rigid motion constraints while simultaneously preserving the physical integrity of the intended inertial dynamics tangent to those constraints. This is in contrast to conventional impedance-control algorithms that focus primarily on rendering reaction forces along contact normals with constraints. We present this algorithm here, which is general to all admittance displays, and report on its implementation with the Cobotic Hand Controller. We offer examples of rigid bodies and linkages subject to holonomic and/or nonholonomic constraints
A case of late‐onset dependence on cocaine and crack
Authors: Kouimtsidis Christos , Padhi Ashwini
Published: February 2007

Aims  To raise awareness among the professional clinical and research community of the risk of cocaine misuse among elderly patients.

Methods  Case report of a male patient, aged 72 years, who presented to a community substance misuse service with cocaine use disorder (hydrochloride and base form).

Results  The development of the disorder was marked by high levels of cocaine (and later crack cocaine use), repeated periods of abstinence followed by relapse in the past 4 years, with severe consequences to the patient and his family. Treatment involved a close collaboration between several specialist addictions and old‐age psychiatry teams in National Health Service.

Implications  Although dependence on cocaine among the elderly is considered very rare, clinical management can be challenging and is likely to require the involvement of several specialist and general health services.
Abundance and utilization of Pyrenacantha sylvestris in Budongo Forest Reserve, western Uganda
Authors: Agea Jacob G. , Odur Stephen Ongom , Babwetera Fred , Kaboggoza J. R. S.
Published: February 2007

Pyrenacantha sylvestris S. Moore (Icacinaceae), locally known as Kateganende, has been extensively harvested by local people yet poorly managed. This has created a gap between its utilization and conservation. A study was therefore conducted to document its abundance and utilization in Budongo Forest Reserve. Abundance was assessed in ten systematically sampled plots of 20 × 50 m. Five of the plots were established in logged forest (compartment N2) and the other five in the nature reserve (compartment N15). Individual P. sylvestris and trellises were recorded and their respective diameter at breast height measured. Questionnaires designed to capture information on the utilization of P. sylvestris were administered to 40 systematically selected respondents adjacent to the forest reserve. Abundance was highest in logged areas of the forest (χ2 = 14.8, d.f. = 4, P < 0.01). Individuals in the diameter class 0.1–0.5 cm were the most abundant. Pyrenacantha sylvestris in the forest were mostly hosted in the trellises of the diameter class 1.0–10 cm. Over‐reliance and use of P. sylvestris threaten the survival of the species. There is a need to create awareness and regulate its harvesting. In addition, research needs to be conducted on the possibility of propagating and domesticating this plant.
Observations on resource use in Mabira Forest Reserve, Uganda
Authors: Baranga Deborah
Published: February 2007

The study was conducted in Mabira Forest Reserve, which is located between Kampala City and Jinja town (Uganda). The Reserve is predominantly occupied by tropical high forest communities of medium altitude moist semi‐deciduous and moist evergreen forest. The forest was greatly influenced by human activities but has been recovering since illegal settlement and encroachment were stopped between 1988 and 1989. An assessment of human activities within the forest was conducted (March–November 2004). Tree stumps were enumerated along transects established in different parts of the forest and the tree species cut identified from the stumps coppicing. Interviews were conducted around four village enclaves to establish forest product utilization. Timber extraction, tree harvesting for building poles, firewood and charcoal burning were common activities in addition to nontimber product utilization. Shoots and thin branches are cut daily for chicken and beef roasting. These activities degrade the forest, compromising its status as a reserve and destroy the habitat and its biodiversity. Drastic management measures are needed to check these activities so as to enhance its conservation status.
Gender mainstreaming and community participation in plant resource conservation in Buzaya county, Kamuli district, Uganda
Authors: Mukadasi Buyinza , Nabalegwa Muhammod
Published: February 2007

The distribution of property rights to land and natural resources underlies the differential control of men and women over productive resources. This article investigates the role played by women in conservation of plant resources in Kamuli district, Uganda. Using a stratified random sampling technique, 60 tree farmers from Bugulumbya, Kasambira and Nawandhyo parish were interviewed. The findings revealed that women tree farmers were constrained by insecure tenure to tree resource, inequitable benefit sharing, male dominance in decision‐making, low education and lack of planting materials. The extension media use varied according to gender. These findings have important policy implications in that for effective tree resource conservation, the information targeting rural women in Uganda should be in their native languages. Local programmes should be integrated into tree resource management programmes for the benefit of the grassroot populations, many of whom have low education levels.
Antibacterial activity of Mangifera indica (L.)
Authors: Bbosa G. S. , Kyegombe D. B. , Ogwal‐Okeng J. , Bukenya‐Ziraba R. , Odyek Olwa , Waako P.
Published: February 2007

Leaf extracts of Mangifera indica (L.), a medicinal and horticultural plant were investigated for antibacterial activity against Staphylococcus aureus, Esherichia coli and Pseudomonas aeruginosa. Using the agar‐well diffusion and the gradient serial dilution methods the extracts showed weak antibacterial activity against the study organisms compared with the positive control (gentamycin). The ethanolic extract was most active with minimum inhibitory concentration ranging from 5481.0 to 43750.0 μg ml−1. Chemical tests showed the presence of saponins, steroids and triterpenoids in the ether fraction, alkaloids, anthracenocides, coumarins, flavonones, reducing sugars, catechol and gallic tannins, saponins, steroids and triterpenoids in the ethanolic portion and anthracenocides, flavonones, reducing sugars in the aqueous fraction of the plant extract. These results shows that leaf extracts of M. indica possess some antibacterial activity that could be the basis for their medicinal use in Uganda.
Uses of tree species producing gum arabic in Karamoja, Uganda
Authors: Egadu Simon P. , Mucunguzi Patrick , Obua Joseph
Published: February 2007

This article presents an inventory of the uses of the tree species producing gum arabic by the local community in the Karamoja region. The study was conduced in 2000 using semi‐structured interviews, focal group discussions and participants’ observation. There were three tree genera with a total of six species that produced gum arabic. These were Balanites aegyptica, Acacia senegal, A. seyal, A. sieberiana, A. gerrardii and Lanea humilis. The dominant species producing gum arabic were A. senegal (85%), A. seyal (87%) and A. sieberiana (70.5%). Other uses by the local people included fencing, fuel wood, poles, crafts, medicine, intercropping, fibre and extraction of tannin. The intensity of utilization for fencing, fuel wood and poles was higher than that of gum arabic production. The local uses of gum arabic were food, gumming spears, gumming pots, gluing arrows, gluing broken stools, calabashes and joining leather. Establishing and facilitating the conservation status of these tree species are important for maintaining and even increasing the provisions for the local uses by the local community in Karamoja.
A study of plant materials used for house construction around Kibale National Park, western Uganda
Authors: Kakudidi Esezah Kyomugisha
Published: February 2007

The relationship between construction materials used and longevity of traditional houses in three parishes adjacent to Kibale National Park in western Uganda was explored. Based on (i) resistance to termite attack, (ii) resistance to insect borers, (iii) rot resistance, (iv) wood that splits well, (v) the wood fibre not entangled, (vi) easy workability, (vii) weight, (viii) straight poles, (ix) availability within 2 km radius and (x) durability, 67 species were recorded, of which 43 are trees, nine climbers, ten shrubs and five herbs. Durable wood resistant to fungal attack, termites and woodborers is preferred in addition to being hard, straight and easy to work with a machete. Ranked high among the wild species are Harrisonia abyssinica Oliver, Millettia dura Dunn., Blighia unijugata Baker and Aegelopsis eggelingii M. R. F. Taylor. The commonly extracted pole sizes are between 5 and 12 cm dbh. Preferred wild ropes to fasten wattle, that are resistant to termites, include Cryptolepis sanguinoleta R. Br., Motandra sp., Urera trinervis (Hochst.) Friis & Imm., Paullinia pinnata L. and Cissus rotundifolia (Forssk.) Vahl. Longevity of houses greatly depended on the wall finishing by plastering with sand/wood ash and cow dung as well as the thatch material used: with the average life span of 14.7 years for grass‐thatched, 20 years for papyrus and 29.9 years for iron‐roofed houses.
The flora of highly degraded and vulnerable wetland ecosystems of Nyamuriro and Doho, Uganda
Authors: Kalema James , Ssegawa Paul
Published: February 2007

The wetlands of Nyamuriro and Doho were surveyed for their flora during the period August 2001 and May 2002. These two wetlands are highly degraded through cultivation. The plants in these areas were documented with a view to determining their richness and conservation importance in Uganda. Two hundred and eight species were recorded in 140 genera, 63 families and 37 orders in Nyamuriro while 184 species, 109 genera, 39 families and 27 orders were recorded in Doho. Although there are no species of global priority conservation concern, these wetlands harbour reasonable numbers of plant species, some of them rare, for their size. Nyamuriro has five species of restricted range in the country occurring in only one of the four floristic regions. Adenostemma caffrum DC. var. longifolium Chiov., from Nyamuriro, is a new record for Uganda. Typically high‐elevation species absent in most wetlands in Uganda, were recorded in Nyamuriro. Plants rare in Uganda were recorded from both Doho and Nyamuriro. These two wetland ecosystems are therefore still vital for the country's flora in terms of species richness, rarity and uniqueness. Nyamuriro needs urgent action to reverse the current trend of habitat loss and degradation. Doho was severely altered and there is a little chance for restoration.
Medicinal plants used in some gynaecological morbidity ailments in western Uganda
Authors: Kamatenesi‐Mugisha Maud , Oryem‐Origa Hannington , Olwa‐Odyek
Published: February 2007

Gynaecological morbidity is one of the most severe conditions under reproductive health. Healthcare providers and planners in Uganda have not taken it seriously among rural communities. This study was carried out mainly to document indigenous knowledge on medicinal plants used by traditional healers in the treatment of some gynaecological morbidity ailments in reproductive healthcare in western Uganda. In addition, the methods of preparation and administration of herbal medicines including the plant parts utilized were established. The research methods used included informal conversations, semi‐structured interviews and discussions, and field excursions. The documented conditions under gynaecological morbidity discussed in this paper include excessive‐bleeding (hypermenorrhea), painful menstruation (dysmenorrhoea), irregular menstruation and prolapsed uterus. Fifty‐two medicinal plants have been documented as being used in the treatment of these ailments and conditions. Leaves are the most commonly harvested plant parts and the most common growth forms harvested are the herbs 51.9%, followed by trees 25% and shrubs 17.3%. Over 50% of these herbal remedies are harvested from the wild ecosystems. The main methods of herbal remedies preparation were boiling, squeezing and pounding and the medicines are administered orally. The nutritional status of individuals plays a vital role in the well‐being and in fighting diseases as some medicinal plants are used as foodstuffs like Lycopersicon esculentum Mill., Mangifera indica L., Carica papaya L., Cucurbita pepo L., Physalis minima L., Rumex abyssinicus Jacq., Daucus carota L., Zingiber officinale Roscoe and Ananas comosus (L.) Merr.
Impact of exotic plantations and harvesting methods on the regeneration of indigenous tree species in Kibale forest, Uganda
Authors: Kasenene John M.
Published: February 2007

Exotic plantations of Cupressus lusitanica Mill, Pinus caribaea Morolet and Eucalyptus species were established in the grasslands of Kibale Forest Reserve during the late 1960s and early 1970s. Thirty years later (1995), plantation harvesting began based on pitsawing and sawmilling methods. This study aimed at assessing the effect of logging exotic plantations and the methods of harvesting on the young regeneration of indigenous tree species. Sample plots were randomly established in the plantations in the sawmilled and pitsawn areas. All tree stems over 1.3 m in height were identified, diameter at 1.3 m and height measured. The plantations showed a total of 91 tree species with the logged C. lusitanica and P. caribaea areas exhibiting higher number of tree species (79 and 78 respectively) than Eucalyptus (55). The pioneer, colonizing and secondary forest species contributed significantly to the density of regeneration in logged C. lusitanica (2170.5 t ha−1), P. caribaea (2309.2 t ha−1) and eucalyptus (1513.7 t ha−1) areas. The Climax species were still very low and the species very scanty. While pitsawing and sawmilling seem to have had little influence on species richness (Ps = 63, Sm = 65), pitsawing encouraged higher tree regeneration densities (ps = 2223.5 t ha−1) than sawmilling (Sm = 1822 t ha−1). Deductively, C. lusitanica and P. caribaea plantations could be used economically in afforestation, reforestation and accelerated natural forest colonization.
Diversity and distribution of Asteraceae along a rainfall gradient in Uganda
Authors: Mbatudde Maria , Mucunguzi Patrick , Lye Kåre A.
Published: February 2007

The diversity and distribution of the family Asteraceae in four habitat types (dry grassland, wet grassland, cultivated land and roadside) were studied from a region of high mean annual rainfall (Entebbe) to a region of lower annual rainfall (Kafu). Eighty‐eight species belonging to 45 genera and nine tribes of the family Asteraceae were identified with Vernonieae 25% (five genera), Heliantheae 25% (seventeen genera) and Senecioniae 17.1% (six genera) strongly represented. The species diversity of the family Asteraceae was highest in the transition region (Luweero to Katuugo) and similar in the highest and lowest mean annual rainfall regions. Dry grassland habitats are more highly diverse than other habitat types, while roadside habitats are least diverse. Species common to high rainfall areas include Elephantopus scaber L. and Bothriocline longipes (Oliv. & Hiern) N. E. Br. Species more common in low rainfall areas include Aspilia kotschyi (Sch. Bip.) Oliv. and Berkheya spekeana Oliv.
Diversity and distribution of hemi‐epiphytes and facultative herbaceous epiphytes in Kibale National Park, Uganda
Authors: Mucunguzi Patrick
Published: February 2007

A survey of the hemi‐epiphytes and other herbaceous facultative epiphytes was performed in Kibale National Park. A total of 100 major host trees were sampled in detail by a canopy‐based single rope technique. A total of thirteen families, thirteen genera with 24 species were found being dominated in terms of species by the family Moraceae with nine species. The most common Ficus species were F. sasibarica and F. conracii, while the herbaceous facultative epiphytes had Rhipsalis baccifera, Peperomia manni and P. tetraphylla as the most common. Correlation analysis revealed no relationship between basal area and the Ficus species. The herbaceous facultative epiphytes increased significantly with increase in the host basal area. Ficus species and the herbaceous facultative epiphytes preferred the ‘base’ and ‘mid’ branch zones of the host trees characterized by a narrow range of vertical distribution in both the logged and un‐logged forests. Most species were found in the ‘light’ and ‘heavy’ humus type of substrates. There was a tendency for the logged forests to have more hemi‐epiphytes and the herbaceous facultative epiphytes than the un‐logged forest types.
Herbal medicine acceptance, sources and utilization for diarrhoea management in a cosmopolitan urban area (Thika, Kenya)
Authors: Njoroge Grace Njeri , Kibunga Joan Wanjiku
Published: February 2007

The use of herbal remedies is usually perceived as a rural phenomenon, hence it is usually not clear whether they are an accepted mode of healthcare system in urban areas. This study aimed at investigating the role of herbal medicines in managing diarrhoea in an urban centre, document important plants utilized and their conservation status. The results indicate that diarrhoea is a serious problem in Thika urban slums. Ninety‐eight per cent in the study area had suffered had suffered diarrhoea in the recent past (during the last 1 year). In regard to the mode of treatment sought for this condition, 97.45% had used herbal preparations. The majority (52.5%) first seek treatment for diarrhoea from herbalists before going to the hospital. More people (23.7%) in the study area seek herbal preparations for diarrhoea management because they consider them more effective than biomedicines, compared with 13.2% who opt for the herbal concoctions because they are cheap. A large diversity of species (41 species in 25 families) is used in diarrhoea management. The most common plants include Senna didymobotrya (Fresen.) Irwin & Barney, Physalis Peruvian L., and Cucurbita maxima Lam. Most of these are obtained from wild habitats, hence their conservation status needs to be addressed.
Microgeographical genetic structure of forest robusta coffee (Coffea canephora, Pierre), in Kibale National Park, Uganda
Authors: Nyakaana Silvester
Published: February 2007

Genetic variation within and between forest coffee (Coffea canephora, Pierre) populations sampled from five localities in Kibale National Park was assessed using six polymorphic microsatellite loci. In a total sample of 113 individuals, 53 alleles were observed across all loci in all populations while the total number of alleles across loci in each population ranged from fifteen to forty‐five. Significant genetic differentiation was observed between all populations in all pair‐wise population comparisons (FST = 0.041–0.284; P < 0.01). A high proportion of private alleles was observed across all loci with some of them occurring at relatively high frequencies. The implications of these findings for the future survival of the species are discussed.
Medicinal plants used by communities of Ngai Subcounty, Apac District, northern Uganda
Authors: Okello Jimmy , Ssegawa Paul
Published: February 2007

An ethnobotanical survey was carried out in Ngai subcounty in Apac District. Three parishes of Ajerijeri, Abok A and Omach were taken as stratified sample areas in which both male and female traditional healers of different ages were interviewed. Information about the medicinal plants and traditional healing was gathered using questionnaires, semi‐structured interviews, informal discussion and field excursion which yielded lists of local plant names, names of diseases treated, mode of administration and parts used. To enhance their effectiveness, medicinal plants are used in combinations to treat various ailments and the extent of knowledge of medicinal plant mixing determines the success of a traditional healer. Roots were the most commonly harvested part and this has greatly affected the regeneration of medicinal plants. It was believed that only plants collected from the wild were effective. Though not intentional, plant parts not used for medicinal purposes are sometimes destroyed in the process of harvesting. This practice, coupled with over harvesting, threatens the continued existence of these plants.
Establishment of plant propagules in the acid mine‐polluted soils of the pyrite trail in Queen Elizabeth National Park, Uganda
Authors: Oryem‐Origa H. , Makara A. M. , Tusiime F. M.
Published: February 2007

The effect of amended acidic pyrite sediments on the germination and establishment of seedlings and vegetative plant propagules of some selected plant species was investigated. The results from this study indicate that the pH values of the pyrite trail ranged from 1.6 to 3.5. Seed germination of all plant species except Bidens pilosa L. was not possible in the pyrite soils (pH 1.6–4.0) in laboratory germination trials. The germination of seeds in amended pyrite soils at pH 5.5 ± 0.2 and 7.0 ± 0.2 was possible. Seeds of Panicum maximum Jacq. and Setaria sphacelata (Schumach.) Stapf and Hubbard ex. Moss were not able to germinate in the unaltered pyrite soil under laboratory conditions. Under field conditions, seed germination was possible in all the plots with amended pyrite soils at pH 5.5 ± 0.2 and 7.0 ± 0.2. Seed germination in the uncontaminated soil was much higher than in the amended pyrite soil. Seedlings were not able to survive for long in the amended soils. Only the vegetative plant propagules of Cynodon dactylon (L) Pers. were able to secure permanent establishment in all amended plots except in plot PT3. Generally, seed germination, seedling establishment, growth and the establishment of vegetative plant propagules in unaltered soils was not possible.
East African medicinal plants as a source of lead compounds for the development of new antimalarial drugs
Authors: Waako P. J. , Katuura E. , Smith P. , Folb P.
Published: February 2007

Four traditional medicinal plants of east and central Africa, Emilia discifolia (Oliv.) C. Jeffrey, Senecio stuhlmannii, Indigofera emarginella A. Rich. and Aspilia africana (Pers) C.D. Adams, were screened for in vitro antimalarial activity using the nitro‐tetrazolium blue‐based parasite lactate dehydrogenase assay. The plant parts were collected in two batches: one in the wet season and the other in the dry season. The ethyl acetate extract of A. africana had the highest antiplasmodial activity against both the chloroquine‐sensitive D10 [inhibitory concentration (IC)50 = 9.3; 7.7–10.9 μg ml−1] and the chloroquine‐resistant K1 (IC50 = 11.5; 8.7–14.3 μg ml−1) strains of P. falciparum. There was a positive correlation between the antiplasmodial activity of the extracts against the D10 and K1 strains of P. falciparum (Pearsons’ coefficient, r = 0.9691, P =0.05). Yields of extracts and their antiplasmodial activity varied with season in some plant species. This study shows that some East African medicinal plants can serve as a source of lead compounds for the development of new drugs against the chloroquine‐sensitive and chloroquine‐resistant strains of P. falciparum. The need for optimization of the conditions of harvest to maximize yields is also highlighted.
Rectal lactate levels in endoluminal microdialysate during routine coronary surgery*
Authors: Solligård E. , Wahba A. , Skogvoll E. , Stenseth R. , Grønbech J. E. , Aadahl P.
Published: February 2007

The aim of this prospective study was to determine the feasibility of intestinal endoluminal microdialysis as a new method for clinical monitoring of the adequacy of splanchnic perfusion in the large bowel. A microdialysis catheter for continuous lactate, glycerol, glucose and pyruvate measurements attached to a tonometric catheter was placed into the lumen of the recto‐sigmoid junction prior to surgery in 13 patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB). Lactate was also measured in blood and muscle. CPB was associated with a 10‐fold increase in luminal lactate from 0.16 (0.01) to 1.67 (0.38) mmol.l−1 (p < 0.001). Muscular lactate increased from baseline levels 1.20 (0.21) to 1.77 (0.36) mmol.l−1 during CPB (p = 0.01), but the muscular lactate–pyruvate ratio remained unchanged. Arterial lactate increased only slightly from 0.9 (0.05) to 1.1 (0.06) mmol.l−1 (p = 0.027) during CPB. Increased lactate concentrations in the large bowel during CPB are suggestive of local lactate production consistent with impaired oxygen delivery. Intestinal endoluminal microdialysis is a potential clinically applicable method for monitoring intestinal metabolism. Combined with tonometry, microdialysis provides the opportunity to monitor both circulation and metabolism in the rectal mucosa.
Psychological assessment of ICU survivors: a comparison between the Hospital Anxiety and Depression scale and the Depression, Anxiety and Stress scale
Authors: Sukantarat K. T. , Williamson R. C. N. , Brett S. J.
Published: February 2007

Recovery from a critical illness can be delayed by persistent anxiety and depression. To identify such patients, a new self‐report questionnaire (the Depression, Anxiety and Stress scale, DASS) was used alongside an established instrument (the Hospital Anxiety and Depression scale, HADS) in those who had spent a minimum of 3 days (median 9 days) in a general intensive care unit. Fifty‐one patients were studied 3 months later, and 45 survivors were reviewed at 9 months. High Cronbach alpha values (0.92–0.95) for each subscale of DASS confirmed its internal consistency, and likewise for HADS (0.82–0.86). HADS and DASS correlated strongly at each time point both for anxiety (r = 0.88) and depression (r = 0.93), with few discrepant values on a Bland and Altman plot. DASS performs as consistently as HADS in screening for anxiety and depression, and its psychometric properties support its use in an intensive care setting.
Retention of tracheal intubation skills by novice personnel: a comparison of the Airtraq® and Macintosh laryngoscopes*
Authors: Maharaj C. H. , Costello J. , Higgins B. D. , Harte B. H. , Laffey J. G.
Published: February 2007

Direct laryngoscopic tracheal intubation is a potentially lifesaving manoeuvre, but it is a difficult skill to acquire and to maintain. These difficulties are exacerbated if the opportunities to utilise this skill are infrequent, and by the fact that the consequences of poorly performed intubation attempts may be severe. Novice users find the Airtraq® laryngoscope easier to use than the conventional Macintosh laryngoscope. We therefore wished to determine whether novice users would have greater retention of intubation skills with the Airtraq® rather than the Macintosh laryngoscope. Twenty medical students who had no prior airway management experience participated in this study. Following brief didactic instruction, each took turns performing laryngoscopy and intubation using the Macintosh and Airtraq® devices in easy and simulated difficult laryngoscopy scenarios. The degree of success with each device, the time taken to perform intubation and the assistance required, and the potential for complications were then assessed. Six months later, the assessment process was repeated. No didactic instruction or practice attempts were provided on this latter occasion. Tracheal intubation skills declined markedly with both devices. However, the Airtraq® continued to provide better intubating conditions, resulting in greater success of intubation, with fewer optimisation manoeuvres required, and reduced potential for dental trauma, particularly in the difficult laryngoscopy scenarios. The substantial decline in direct laryngoscopy skills over time emphasise the need for continued reinforcement of this complex skill.
The circulatory responses to tracheal intubation in children: a comparison of the oral and nasal routes
Authors: Xue F. S. , Liao X. , Liu K. P. , Liu Y. , Xu Y. C. , Yang Q. Y. , Li P. , Li C. W. , Sun H. T.
Published: February 2007

The circulatory responses to laryngoscopic tracheal intubation in 62 healthy children undergoing surgery requiring tracheal intubation were studied. They were randomly assigned to receive either the oral or nasal route for intubation. Baseline non‐invasive blood pressure and heart rate were recorded following induction of anaesthesia, at intubation and then every minute for 5 min. The percentage changes of systolic blood pressure and heart rate during the measurement period were calculated. The results demonstrated that intubation time was significantly longer in the nasal group. Both oral and nasal intubation caused significant increases in blood pressure and heart rate compared to baseline and postinduction values. However, there were no significant differences found between the two groups in relation to blood pressure and heart rate. The two groups were similar with respect to the percentage changes of systolic blood pressure and heart rate during the observation period. It is concluded that oral and nasal intubation using a direct laryngoscopy can result in a similar circulatory response in anaesthetised children.
The short‐term effect of hyperoncotic albumin, given alone or with furosemide, on oxygenation in sepsis‐induced Acute Respiratory Distress Syndrome
Authors: Kuper M. , Gunning M. P. , Halder S. , Soni N.
Published: February 2007

Two prospective non‐randomised interventional case series were conducted consecutively at a single university hospital mixed intensive care unit, in patients with severe sepsis and acute respiratory distress syndrome. The first series describes the administration of 200 ml of 20% human albumin solution over 120 s in 13 patients, examining the hypothesis that raising plasma albumin should improve oxygenation. The second series describes the effect of administering 30 mg of furosemide intravenously along with the albumin in 15 patients, exploring whether this would produce more sustained improvement in oxygenation than albumin only. Oxygenation and haemodynamic parameters were measured for 4 h, during the period of peak oncotic effect. Hyperoncotic albumin given alone or with furosemide produced only transient improvement in oxygenation and haemodynamics, which was statistically significant only in the patients given albumin alone. Although the plasma albumin remained significantly elevated at 4 h in both series, no sustained improvement in oxygenation was seen.
Temporary epicardial pacing after cardiac surgery: a practical review
Authors: Reade M. C.
Published: February 2007

Epicardial wires allow temporary pacing after cardiac surgery. Pacing is often the best, and sometimes the only method of treating temporary rhythm disturbances in this context. Temporary epicardial pacing has evolved from simple one‐chamber systems to dual chamber, biatrial, and even biventricular systems. The first part of this two‐part review provides an overview of the management of temporary epicardial pacing systems. Factors influencing the placement of the various types of epicardial wires and the routine care of a pacemaker‐dependent patient are outlined, followed by a description of the diagnostic use of pacing wires, how to remove wires, and when to consider transition to permanent pacing. Special circumstances such as compatibility with magnetic resonance imaging and intra‐aortic balloon pumps are also discussed. The second part of this review will describe the various pacing modes, and solutions to common pacing problems using various adjustable parameters.
The use of drotrecogin alfa (activated) in a patient with recent orthotopic liver transplant*
Authors: Browne E. , Cressey D. M. , Agarwal K. , Cosgrove J. F.
Published: February 2007

Drotrecogin alfa has been shown to reduce mortality in severe sepsis. However, it remains unlicensed for use in patients with previous liver transplantation. We report its use in such a case. Prior to administration a risk benefit analysis was performed in line with General Medical Council recommendations. This included being satisfied that no appropriately licensed alternative would better serve the patient's needs and that sufficient evidence existed to demonstrate the safety and efficacy of the drug. Responsibility was taken for prescription, monitoring and follow up. The process was carefully documented and the patient recovered fully with no adverse effects. To date the only published data on the use of drotrecogin alpha in transplant recipients is a case series of three patients. Further published data may encourage review of the licence.
Minimally invasive endoscopic port‐access™ intracardiac surgery with one lung ventilation: impact on gas exchange and anaesthesia resources
Authors: Kottenberg‐Assenmacher E. , Kamler M. , Peters J.
Published: February 2007

Minimally invasive endoscopic intracardiac surgery including one lung ventilation has been proposed to decrease surgical trauma but its impact on oxygenation and resource consumption has not been reported. We compared effects on gas exchange, induction, total anaesthesia time, staffing costs, and complications in 42 consecutive patients to a matched group undergoing similar surgery conventionally. Use of endoscopic compared to conventional surgery evoked a decrease in the Pao2/FIo2 ratio (mean (SD) 24.1 (14.9) vs 48.9 (14) kPa, p < 0.05) following termination of bypass with one lung ventilation (10 patients showed a Pao2/Fio2 below 13.3 kPa (100 mmHg)). There was also an increase of anaesthesia induction time (47 (13) vs 31 (9) min, p < 0.05), and an increase by 156 min of total anaesthesia time (474 (89) vs 321 (69) min, p < 0.05). Anaesthetist staffing costs increased by 300%. Thus, minimally invasive endoscopic intracardiac surgery consumes many more anaesthesia resources than conventional surgery and can result in hypoxaemia, but overall can be considered feasible provided that extensive continuous monitoring is employed.
Head position for opening the upper airway
Authors: Paal P. , Goedecke A. v. , Brugger H. , Niederklapfer T. , Lindner K. H. , Wenzel V.
Published: February 2007

Inexperienced rescuers may encounter severe problems in an unconscious patient with opening and maintaining a patent upper airway. Designing a ventilating device that could indicate how to open an upper airway correctly may be beneficial. The heads of 102 volunteers were randomly placed in different head positions by one investigator. A pocket mask was then pressed gently on the volunteer's face followed by measurement of the head position angles. Mean (SD) flexion was − 4° (8°) (95% CI − 5.9 to − 2.9); the mean neutral position was 21° (6°) (95% CI, 19.9 to 22.3); extension was 42° (6°) (95% CI 40.8 to 43.0°) and differed significantly between each position (p < 0.001). The flexion and neutral position angles were significantly greater in men than in women: − 2 (7°) vs. −8 (7°) and 22 (7°) vs 20 (5°); p < 0.001 and p = 0.03, respectively. Maximum extension of the head in both supine men and women was 42°, which could be utilised to optimise assisted ventilation of an unprotected upper airway.
The effect of alcohol swabs and filter straws on reducing contamination of glass ampoules used for neuroaxial injections*
Authors: Hemingway C. J. , Malhotra S. , Almeida M. , Azadian B. , Yentis S. M.
Published: February 2007

We have investigated the incidence of contamination of the contents of glass ampoules used for neuraxial injections, and whether this was reduced by wiping the outsides of the ampoules with isopropyl alcohol or using a filter straw. One hundred fentanyl and diamorphine ampoules used for routine regional anaesthesia were either wiped or not wiped with alcohol before their contents were aspirated, and the residual contents were swabbed and incubated. None of the swabs from the wiped ampoules grew organisms compared with nine (18%) from non‐wiped ampoules (p = 0.004). In a second, laboratory study, 100 glass ampoules of saline were coated with Staphylococcus aureus and divided into four groups: wiped/not wiped with alcohol and with/without a filter straw. The contents of the ampoules were aspirated; the remnants and the aspirate were swabbed and incubated as before. Most contamination occurred in the unwiped groups and although numbers were small, filtering appeared to reduce contamination further. As filter straws also reduce the risk of injecting glass particles (even if not contaminated), our results suggest that wiping glass ampoules with isopropyl alcohol and using a filter straw should be part of routine practice when performing regional anaesthesia.
Influence of CYP2C9 and CYP2C19 genetic polymorphisms on pharmacokinetics of gliclazide MR in Chinese subjects
Authors: Zhang Yifan , Si Dayong , Chen Xiaoyan , Lin Nan , Guo Yingjie , Zhou Hui , Zhong Dafang
Published: February 2007

What is already known about this subject

• Gliclazide has been considered metabolized by CYP2C9.

• Its modified release formulation, gliclazide MR, shows low pharmacokinetic variability in Whites but high variability in Chinese.

What this study adds

• The results of this study show that the pharmacokinetics of gliclazide MR are affected mainly by CYP2C19 genetic polymorphism instead of CYP2C9 genetic polymorphism.

• CYP2C19 genetic polymorphism might be responsible for the high pharmacokinetic variability of gliclazide MR in Chinese.

Aims To investigate the influence of CYP2C9 and CYP2C19 genetic polymorphisms on the pharmacokinetics of gliclazide modified release (MR) in healthy Chinese subjects.

Methods In a single‐dose pharmacokinetic study, 24 healthy male subjects with various CYP2C9 and CYP2C19 genotypes received an oral dose of 30 mg gliclazide MR and plasma was sampled for 72 h postdose. In a multiple‐dose pharmacokinetic study, 17 other CYP2C9*1 homozygotes with various CYP2C19 genotypes received 30 mg gliclazide MR once daily for 6 days and plasma was sampled after the last dose. The plasma concentrations of gliclazide were measured using a validated LC/MS/MS method. CYP2C9 and CYP2C19 genotypes were determined by polymerase chain reaction‐restriction fragment length polymorphism analysis.

Results In the single‐dose study, no significant difference in any pharmacokinetic parameters was found in CYP2C9*1/*1, *1/*3 and *1/*13 subjects. In contrast, the AUC0–∞ of gliclazide was significantly increased by 3.4‐fold [95% confidence interval (CI) 2.5, 4.7; P < 0.01] in CYP2C19 poor metabolizer (PM) subjects compared with CYP2C19*1 homozygotes. The half‐life (t1/2) was prolonged from 15.1 to 44.5 h (P < 0.01). Similar differences were found in the multiple‐dose study. The parameters of gliclazide AUCss, AUC0–∞ and Cmax were 3.4‐fold (95% CI 2.9, 4.0), 4.5‐fold (95% CI 3.8, 5.4) and 2.9‐fold (95% CI 2.4, 3.4) increased (P < 0.01) in CYP2C19 PM subjects, respectively, compared with CYP2C19*1 homozygotes, and t1/2 was increased from 13.5 to 24.6 h (P < 0.01).

Conclusions The pharmacokinetics of gliclazide MR are affected mainly by CYP2C19 genetic polymorphism instead of CYP2C9 genetic polymorphism.