Biomedical subjects

M Bush

Publications and source records attributed to M Bush.

At least 19 recordsLinked to original sources

PubMed2005

Anaesthesia of nyala (Tragelaphus angasi) with a combination of thiafentanil (A3080), medetomidine and ketamine.

A combination of thiafentanil (A3080), medetomidine hydrochloride (MED) and ketamine hydrochloride (KET) was evaluated in 19 boma-habituated (12 female and 7 males) and 9 free-ranging nyala (7 male and 2 females) (Tragelaphus angasi) to develop a safe and reliable anaesthesia protocol. Wide dosages were used safely during this study with ranges for A3080 of 45 +/- 8 microg/kg with MED of 69 +/- 19 microg/kg and KET of 3.7 +/- 1.0 mg/kg (200 mg/ animal). The dosages developed on boma-habituated nyala proved to be equally effective in 9 adult free-ranging nyala (7 males and 2 females). The optimum dosage for nyala was a combination of A3080 (40-50 microg/kg), MED (60-80 microg/kg) plus 200 mg of KET/animal. The anaesthesia was characterised by a short induction, good muscle relaxation and mild hypoxaemia during monitoring the anaesthesia was rapidly and completely reversed by naltrexone hydrochloride (30 mg/mg of A3080) and atipamezole hydrochloride (5 mg/mg of MED) given intramuscularly. There was no mortality or morbidity associated with this protocol.

Anesthesia↗

PubMed2004

Immobilisation of impala (Aepyceros melampus) with a ketamine hydrochloride/medetomidine hydrochloride combination, and reversal with atipamezole hydrochloride.

A combination of medetomidine hydrochloride (medetomidine) and ketamine hydrochloride (ketamine) was evaluated in 16 boma-confined and 19 free-ranging impalas (Aepyceros melampus) to develop a non-opiate immobilisation protocol. In free-ranging impala a dose of 220 +/- 34 microg/kg medetomidine and 4.4 +/- 0.7 mg/kg ketamine combined with 7500 IU of hyaluronidase induced recumbency within 4.5 +/- 1.5 min, with good muscle relaxation, a stable heart rate and blood pH. PaCO2 was maintained within acceptable ranges. The animals were hypoxic with reduced oxygen saturation and low PaO2 in the presence of an elevated respiration rate, therefore methods for respiratory support are indicated. The depth of sedation was adequate for minor manipulations but additional anaesthesia is indicated for painful manipulations. Immobilisation was reversed by 467 +/- 108 microg/kg atipamezole hydrochloride (atipamezole) intramuscularly, but re-sedation was observed several hours later, possibly due to a low atipamezole:medetomidine ratio of 2:1. Therefore, this immobilisation and reversal protocol would subject impalas to possible predation or conspecific aggression following reversal if they were released into the wild. If the protocol is used on free-ranging impala, an atipamezole:medetomidine ratio of 5:1 should probably be used to prevent re-sedation.

Adrenergic alpha-Antagonists↗

PubMed2004

Severe hypoxaemia in field-anaesthetised white rhinoceros (Ceratotherium simum) and effects of using tracheal insufflation of oxygen.

White rhinoceros anaesthetised with etorphine and azaperone combination develop adverse physiological changes including hypoxia, hypercapnia, acidosis, tachycardia and hypertension. These changes are more marked in field-anaesthetised rhinoceros. This study was designed to develop a technique to improve safety for field-anaesthetised white rhinoceros by tracheal intubation and oxygen insufflation. Twenty-five free-ranging white rhinoceros were anaesthetised with an etorphine and azaperone combination for translocation or placing microchips in their horns. Once anaesthetised the rhinoceros were monitored prior to crating for transportation or during microchip placement. Physiological measurements included heart and respiratory rate, blood pressure and arterial blood gas samples. Eighteen rhinoceros were intubated using an equine nasogastric tube passed nasally into the trachea and monitored before and after tracheal insufflation with oxygen. Seven rhinoceros were not intubated or insufflated with oxygen and served as controls. All anaesthetised rhinoceros were initially hypoxaemic (percentage arterial haemoglobin oxygen saturation (%O2Sa) = 49% +/- 16 (mean +/- SD) and PaO2 = 4.666 +/- 1.200 kPa (35 +/- 9 mm Hg)), hypercapnic (PaCO2 = 8.265 +/- 1.600 kPa (62 +/- 12 mm Hg)) and acidaemic (pHa = 7.171 +/- 0.073 ). Base excess was -6.7 +/- 3.9 mmol/l, indicating a mild to moderate metabolic acidosis. The rhinoceros were also hypertensive (systolic blood pressure = 21.861 +/- 5.465 kPa (164 +/- 41 mm Hg)) and tachycardic (HR = 107 +/- 31/min). Following nasal tracheal intubation and insufflation, the %O2Sa and PaO2 increased while blood pHa and PaCO2 remained unchanged. Tracheal intubation via the nose is not difficult, and when oxygen is insufflated, the PaO2 and the %O2Sa increases, markedly improving the safety of anaesthesia, but this technique does not correct the hypercapnoea or acidosis. After regaining their feet following reversal of the anaesthesia, the animals' blood gas values return towards normality.

Acid-Base Equilibrium↗

PubMed2001

Use of medetomidine and ketamine for immobilization of free-ranging giraffes.

OBJECTIVE: To develop a dosage correlated with shoulder height (SH) in centimeters for effective immobilization of free-ranging giraffes, using a combination of medetomidine (MED) and ketamine (KET) and reversal with atipamezole (ATP). DESIGN: Prospective study. ANIMALS: 23 free-ranging giraffes. PROCEDURE: The drug combination (MED and KET) was administered by use of a projectile dart. Quality of induction, quality of immobilization, and time to recovery following injection of ATP were evaluated. Physiologic variables measured during immobilization included PaO2, PaCO2, oxygen saturation, end-tidal CO2, blood pH, indirect arterial blood pressure, heart and respiratory rates, and rectal temperature. RESULTS: Sixteen giraffes became recumbent with a dosage (mean +/- SD) of 143 +/- 29 microg of MED and 2.7 +/- 0.6 mg of KET/cm of SH. Initially, giraffes were atactic and progressed to lateral recumbency. Three giraffes required casting with ropes for data collection, with dosages of 166 +/- 5 microg of MED and 3.2 +/- 0.6 mg of KET/cm of SH. Four giraffes required administration of etorphine (n = 2) or were cast with ropes (2) for capture but remained dangerous to personnel once recumbent, precluding data collection. In giraffes successfully immobilized, physiologic monitoring revealed hypoxia and increased respiratory rates. Values for PaCO2, end-tidal CO2, and heart rate remained within reference ranges. All giraffes were hypertensive and had a slight increase in rectal temperature. Atipamezole was administered at 340 +/- 20 microg/cm of SH, resulting in rapid and smooth recoveries. CONCLUSIONS AND CLINICAL RELEVANCE: Medetomidine and KET was an effective immobilizing combination for free-ranging giraffes; however, at the dosages used, it does not induce adequate analgesia for major manipulative procedures. Quality of induction and immobilization were enhanced if the giraffe was calm. Reversal was rapid and complete following injection of ATP.

Adrenergic alpha-Agonists↗

PubMed2001

Approaches to understanding the functional architecture of the plant cell wall.

Cell wall polysaccharides are some of the most complex biopolymers known, and yet their functions remain largely mysterious. Advances in imaging methods permit direct visualisation of the molecular architecture of cell walls and the modifications that occur to polymers during growth and development. To address the structural and functional relationships of individual cell wall components, we need to better characterise a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification. We have developed a rapid method to screen large numbers of plants for a broad range of cell wall phenotypes using Fourier transform infrared microspectroscopy and Principal Component Analysis. We are using model systems to uncover the genes that encode some of the cell-wall-related biosynthetic and hydrolytic enzymes, and structural proteins.

Arabidopsis↗

PubMed2001

Physical restraint techniques and immobilization equipment.

The art of safe and effective restraint of non-domestic patients can aid in their management and facilitate their health care delivery. This article discusses some of the strategies and basic equipment required in handling these unique patients more commonly seen by veterinary practitioners. These restraint procedures may offer an alternative to anesthesia for minor, less stressful procedures that do not involve pain.

Animals↗

PubMed2001

Phylogenetics, genome diversity and origin of modern leopard, Panthera pardus.

Leopards, Panthera pardus, are widely distributed across southern Asia and sub-Saharan Africa. The extent and phylogeographic patterns of molecular genetic diversity were addressed in a survey of 77 leopards from known geographical locales representing 13 of the 27 classical trinomial subspecies. Phylogenetic analysis of mitochondrial DNA sequences (727 bp of NADH5 and control region) and 25 polymorphic microsatellite loci revealed abundant diversity that could be partitioned into a minimum of nine discrete populations, tentatively named here as revised subspecies: P. pardus pardus, P. p. nimr, P. p. saxicolor, P. p. fusca, P. p. kotiya, P. p. delacouri, P. p. japonensis, P. p. orientalis and P. p. melas. However, because of limited sampling of African populations, this may be an underestimate of modern phylogeographic population structure. Combined phylogeographic and population diversity estimates support an origin for modern leopard lineages 470,000-825,000 years ago in Africa followed by their migration into and across Asia more recently (170,000-300,000 years ago). Recent demographic reductions likely have led to genetic impoverishment in P. p. orientalis and in the island subspecies P. p. kotiya.

Africa South of the Sahara↗

PubMed2001

Anaesthesia of roan antelope (Hippotragus equinus) with a combination of A3080, medetomidine and ketamine.

A dose range was determined for anaesthesia of 20 recently boma-captured roan antelope (Hippotragus equinus) with the synthetic opiate A3080 combined with medetomidine and ketamine. A dose of 10-30 micro/kg A3080 (x = 20+/-8 microg/kg) combined with 5-21 microg/kg medetomidine (x = 13+/-7 microg/kg) plus 0.29-1.11 mg/kg ketamine (x = 0.71+/-0.24 mg/kg) was found to be safe and effective for the field conditions in this study. The anaesthesia produced by this drug combination was predictable and characterised by a short induction time, good muscle relaxation, and acceptable physiological parameters for anaesthesia periods ranging from 49-103 min (x = 64+/-19 min). The wide range (3-4-fold) of doses with acceptable results is also an indication that this drug combination has a wide margin of safety in roan antelope, making it desirable for field use. When 2 dose levels (2-3-fold dif ference) were retrospectively evaluated, no statistical difference was found in induction times, and no observable clinical differences in the anaesthetic episodes were seen. Based on this study, the recommended dose range in roan antelope for this combination is 10-13 microg/kg A3080, 5-6 microg/kg medetomidine and 0.3-0.6 mg/kg ketamine. The anaesthesia produced by this combination was rapidly and completely reversed by i.m. or i.v. injections of naltrexone at 30 times the A3080 dose (x = 0.60+/-0.25 mg/kg) and atipamezole at 3 times the medetomidine dose (x = 38+/-20 microg/kg). No residual effects from ketamine were noted following reversal of A3080 and medetomidine. No mortality was associated with this protocol.

Analgesics↗

PubMed2001

Anaesthesia of gemsbok (Oryx gazella) with a combination of A3080, medetomidine and ketamine.

An effective anaesthesia protocol was developed for adult free-ranging gemsbok (Oryx gazella) using a combination of A3080, medetomidine and ketamine. A short induction time; good muscle relaxation, adequate oxygenation and stable heart rate and respiration rate characterised this anaesthetic regime. Equal doses of A3080 and medetomidine (22-45 microg/kg) plus 200 mg of ketamine were administered to each animal. The anaesthesia was rapidly and completely reversed by intramuscular naltrexone at a dose of X = 0.9 +/- 0.2 mg/kg and atipamezole at a dose X +/- 90 +/- 20 microg/kg. No mortality or morbidity occurred with this protocol.

Analgesics↗

PubMed2000

Pectin engineering: modification of potato pectin by in vivo expression of an endo-1,4-beta-D-galactanase.

Potato tuber pectin is rich in galactan (oligomer of beta-1,4-linked galactosyl residues). We have expressed a fungal endo-galactanase cDNA in potato under control of the granule bound starch synthase promoter to obtain expression of the enzyme in tubers during growth. The transgenic plants displayed no altered phenotype compared with the wild type. Fungal endo-galactanase activity was quantified in the transgenic tubers, and its expression was verified by Western blot analysis. The effect of the endo-galactanase activity on potato tuber pectin was studied by Fourier transform infrared microspectroscopy, immuno-gold labeling, and sugar analysis. All analyses revealed alterations in pectin composition. Monosaccharide composition of total cell walls and isolated rhamnogalacturonan I fragments showed a reduction in galactosyl content to 30% in the transformants compared with the wild type. Increased solubility of pectin from transgenic cell walls by endo-polygalacturonase/pectin methylesterase digestion points to other changes in wall architecture.

Genetic Engineering↗

PubMed2000

Comparing ovulation synchronization protocols for artificial insemination in the scimitar-horned oryx (Oryx dammah).

Ovarian response and pregnancy success in scimitar-horned oryx (n=28) were compared, following treatment with two synchronization protocols and fixed-time artificial insemination (AI) with frozen-thawed semen. Each oryx received two injections of 500 microg of prostaglandin-F(2alpha) analogue (PGF(2alpha)-only) 11 days apart, and half received PGF(2alpha) in combination with an intravaginal progesterone-releasing device (CIDR11+PGF(2alpha)). Semen was collected by electroejaculation from anaesthetised adult oryx and cryopreserved. Anaesthetised females were transcervically inseminated 56.0+/-1.1 h (+/-S.E.M.) after PGF(2alpha) injection and/or device withdrawal using 28.0+/-1.5x10(6) motile thawed sperm. Ovarian endocrine response was monitored in 20 females by analysing faecal oestrogen and progesterone metabolites. Periovulatory oestrogen peaks were detected in 19/20 (95%) females after synchronization. There were no between-treatment differences in oestrogen concentrations or peak characteristics (P0.05). Luteal development after synchronization was delayed in half the progesterone treated (CIDR11+PGF(2alpha)) females, and faecal progestin excretion profiles indicated that the ovulatory follicle associated with synchronization either failed to ovulate or to fully lutenise. Pregnancy was diagnosed by ultrasonography and/or rectal palpation and was monitored by faecal progestin excretion. More (P=0. 013) pregnancies resulted from the PGF(2alpha)-only treatment (37.5%, 5/14) than from the CIDR11+PGF(2alpha) treatment (0/14), and four healthy scimitar-horned oryx calves were born, three after gestation intervals of 247 days and one after 249 days.

Administration, Intravaginal↗

PubMed2000

Safety and efficacy of solvent/detergent-treated antihaemophilic factor with an added 80 degrees C terminal dry heat treatment in patients with haemophilia A.

Plasma-derived factor VIII concentrates remain an important resource for haemophilia A patients. To improve the safety of these preparations, various methods of viral removal and inactivation have been used that are designed to eliminate both enveloped and non-enveloped viruses. There have been rare reports that some viral inactivation processes altered the immunogenicity of some concentrates, leading to the development of factor VIII inhibitors in previously treated haemophilia A patients. This study evaluated the safety, efficacy and lack of neo-antigenicity of a highly purified factor VIII preparation which undergoes both solvent/detergent treatment and final dry heat treatment at 80 degrees C for 72 h. The study included: (i) a single blind, single-dose crossover pharmacokinetic study in 18 previously treated patients, comparing sibling lots of the unheated preparation (Koate(R)-HP) and the heat-treated preparation (Koate(R)-DVI), and (ii) an extended home treatment programme for 36 patients at two haemophilia treatment centres primarily to assess immunogenicity. Clinical parameters were assessed at regular intervals. The results confirm that Koate(R)-HP and Koate(R)-DVI are bioequivalent, and that Koate(R)-DVI is safe and efficacious for treatment of acute bleeding episodes and for surgery. Furthermore, the heat-treated preparation is not associated with the development of inhibitors in previously treated patients.

Adolescent↗

PubMed2000

An abundant TIP expressed in mature highly vacuolated cells.

Aquaporins are water channel proteins found in vacuolar membranes and plasma membranes, and belong to the major intrinsic protein (MIP) family of proteins. In the present study, we purified a 75 kDa MIP protein from a crude fraction of spinach leaf intracellular membranes. Upon urea/SDS-PAGE, the 75 kDa protein appeared as a 21 kDa polypeptide, and the 75 kDa species therefore probably represents a tetramer. The corresponding cDNA was obtained by PCR cloning and had an open reading frame encoding a 25.1 kDa protein. The protein, So-deltaTIP, was most homologous to the tonoplast intrinsic protein (TIP) subfamily of plant MIPs. Using affinity-purified So-deltaTIP-specific peptide antibodies, we investigated the subcellular and tissue distribution of So-deltaTIP. So-deltaTIP was specifically located in the vacuolar membrane. It was abundant in most vacuolated cells in all vegetative organs, but was excluded from the leaf epidermis as well as from the root phloem parenchyma and meristem. In spite of the high sequence homology between delta-TIPs of spinach, Arabidopsis, sunflower and radish, their expression patterns were totally different. However, a comparison of the expression pattern of So-deltaTIP with that of more distantly related TIPs showed similarities with Arabidopsis gamma-TIP, which is expressed in zones of cell elongation/differentiation but excluded from meristematic tissues. Meristematic cells are characterized by many small vacuoles as opposed to elongating and mature cells, which generally harbour a single, large vacuole. Our results indicate that the expression of So-deltaTIP may be induced when the large vacuole is formed.

Amino Acid Sequence↗

PubMed2000

Subcutaneous atypical mycobacteriosis in captive tiger quolls (Dasyurus maculatus).

From July 1989 to October 1998, 9/37 (24%) adult captive tiger quolls (Dasyurus maculatus) were diagnosed with atypical mycobacterial infection involving the subcutis and skin. Females were more often affected than males (seven females, two males). Grossly, lesions presented as focal thickenings, plaques, and abscesses within the subcutis, often with fistulous tracts. The subcutis and skin overlying cervical and thoracic regions were the primary sites of infection. Cytology of subcutaneous impression smears from all nine affected tiger quolls revealed pyogranulomatous inflammation admixed with several acid-fast bacilli. Histologically, all tiger quolls had nodular to diffuse pyogranulomatous panniculitis and cellulitis. Small numbers of acid-fast bacilli were noted histologically in 7/9 (78%) animals. Skin cultures from seven tiger quolls were positive for one or more different Runyon group IV mycobacteria. The disease described in these tiger quolls is similar to subcutaneous atypical mycobacteriosis of humans and domestic animals.

Animals↗

PubMed2000

Serum oxytetracycline concentrations in African elephant (Loxodonta africana) calves after long-acting formulation injection.

Serum oxytetracycline pharmacokinetics were studied in 18 African elephant (Loxodonta africana) calves. Each elephant received separate injections of oxytetracycline at approximately 18 mg/kg i.m. and 8 mg/kg i.v. in a cross-over study. Blood samples were drawn at 0, 24, 48, 72, and 96 hr postinjection. An additional sample was drawn 110 hr before the animals were reinjected in the cross-over study and a final blood sample was drawn 48 hr after the second dose. No lameness or stiffness was observed following i.m. injections. Serum oxytetracycline concentrations >0.5 microg/ml were present 48 hr after initial dosing for all elephants (i.m., i.v., high or low dosage). Only elephants given the high i.m. dosage (18 mg/kg) maintained levels >0.5 microg/ml 72 hr postinjection. No significant difference in serum oxytetracycline concentration with time was observed between the groups given different i.v. dosages. These studies demonstrated that quantifiable serum oxytetracycline concentrations can be maintained in young African elephants with a low-dosage multidose i.m. regimen.

Animals↗

PubMed2000

Anesthesia in female white-tailed deer using Telazol and xylazine.

Thirty two free-ranging female white-tailed deer (Odocoileus virginianus) were anesthesized with varying Telazol and xylazine HCl combinations in Front Royal (Virginia, USA) between August 1992 and September 1992. All animals were caught in baited box traps, manually restrained, and hand injected with a combination of Telazol and xylazine administered intramuscularly. Deer received mean +/- SE dosages of 2.53+/-0.16 mg/kg Telazol and 0.69+/-0.05 mg/kg of xylazine. These dosages achieved a rapid and effective anesthetic plane for short-term procedures such as weighing, blood collection, and translocation. Eight of 32 deer (25%) required an intravenous (i.v.) supplement of ketamine HCl (100 mg) to maintain a safe plane of anesthesia. Ketamine supplementation provided an average of 11.8+/-2.0 min additional safe handling. Satisfactory reversals were achieved in all deer by administering yohimbine HCl 16 mg i.v. (dose range, 0.22 to 0.48 mg/kg) to all animals.

Adrenergic alpha-Agonists↗

PubMed2000

Diverticulitis with rupture and fatal peritonitis in a Sumatran orangutan (Pongo pygmaeus).

A 30-year-old male Sumatran orangutan (Pongo pygmaeus) presented with signs of depression, lethargy, anorexia, and diarrhea that progressed to acute colic. Exploratory laparotomy revealed fibrinopurulent peritonitis and 50 cm of devitalized small intestine. The surgically resected small intestine contained several mucosal diverticula along the mesenteric attachment; one had ruptured, resulting in peritonitis. Fifteen days after surgery, the orangutan's abdominal incision dehisced. Repeated laparotomy revealed dehiscence of the distal intestinal anastomosis site, as well as extensive adhesions and purulent exudate. The defect was repaired, and the abdomen was extensively irrigated and closed, but the animal died within 24 hours. To our knowledge, this is the first report of diverticulitis in a great ape. Diverticulosis should be considered in the differential diagnosis for great apes that present with signs of depression, lethargy, anorexia, and/or diarrhea.

Animals↗

PubMed1999

The 65-kDa carrot microtubule-associated protein forms regularly arranged filamentous cross-bridges between microtubules.

In plants, cortical microtubules (MTs) occur in characteristically parallel groups maintained up to one microtubule diameter apart by fine filamentous cross-bridges. However, none of the plant microtubule-associated proteins (MAPs) so far purified accounts for the observed separation between MTs in cells. We previously isolated from carrot cytoskeletons a MAP fraction including 120- and 65-kDa MAPs and have now separated the 65-kDa carrot MAP by sucrose density centrifugation. MAP65 does not induce tubulin polymerization but induces the formation of bundles of parallel MTs in a nucleotide-insensitive manner. The bundling effect is inhibited by porcine MAP2, but, unlike MAP2, MAP65 is heat-labile. In the electron microscope, MAP65 appears as filamentous cross-bridges, maintaining an intermicrotubule spacing of 25-30 nm. Microdensitometer-computer correlation analysis reveals that the cross-bridges are regularly spaced, showing a regular axial spacing that is compatible with a symmetrical helical superlattice for 13 protofilament MTs. Because MAP65 maintains in vitro the inter-MT spacing observed in plants and is shown to decorate cortical MTs, it is proposed that this MAP is important for the organization of the cortical array in vivo.

Cell Membrane↗