PubMed Health⌕ Search

Biomedical subjects

P Anthony

Publications and source records attributed to P Anthony.

At least 19 recordsLinked to original sources
PubMed2004

Hemoglobin promotes somatic embryogenesis in peanut cultures.

Critical parameters influencing somatic embryogenesis include growth regulators and oxygen supply. Consequently, the present investigation has focused on optimization of a somatic embryogenic system for peanut (Arachis hypogaea L.) through media supplementation with the auxin, picloram. The latter at 30 mg L(-1) was optimal for inducing regeneration of somatic embryos from cultured explants of zygotic embryos. In contrast, somatic embryogenesis did not occur in the absence of this growth regulator. An assessment has also been made of the beneficial effect on somatic embryogenesis and plant regeneration of the commercial hemoglobin (Hb) solution, Erythrogen. Hemoglobin at 1:50 and 1:100 (v:v) stimulated increases in mean fresh weight (up to a maximum of 57% over control), mean number of explants producing somatic embryos (15%) and mean number of somatic embryos per explant (29%).

Arachis↗
PubMed2002

Ultrasound-induced physiological changes in cultured cells of Petunia hybrida.

Petunia hybrida cell suspension cultures were exposed to ultrasonic standing wave fields at 2.43 MHz for 40 min with mean sound pressures (within homogenous sound fields) varying from 0 (control) to ca. 1.1 MPa. Mean (+/- s.d.; n =6-9) cell viability was reduced to 87+/-10% at 0.6 MPa and to 59 +/- 23% at 1.1 MPa, compared to an initial control value of 92 +/- 6% (P <0.05). Mean (n = 3) cell alkaline phosphatase concentration increased linearly with sound pressure from a control value of 0.006+/-0.001 to 0.02+/-0.01 Sigma-Units microg(-1) protein at 1.1 MPa (P<0.05). Similarly, mean cell catalase activity increased from a control value of 0.020 +/- 0.003 to 0.026 +/- 0.008 arbitrary units at 1.1 MPa. In contrast, mean cellular lactate dehydrogenase concentration was unchanged. These observations indicate that cellular repair processes associated with increased alkaline phosphatase activity might be triggered by physical cell damage caused by ultrasound. The observed increase in catalase activity suggests increasing production of free radicals and other sonochemicals, which warrants further study. The absence of changes in lactate dehydrogenase indicates that there was no major damage to respiratory pathways or to overall cellular integrity.

Alkaline Phosphatase↗
PubMed2001

Hemoglobin-stimulated growth and antioxidant activities in cultured cotton cells.

Changes in cellular reactive oxygen scavenging enzymes were assessed in suspension-derived cells of cotton (Gossypium herbaceum) cv. Dhumad following culture with a commercial bovine hemoglobin (Hb) solution (Erythrogen) at 1:100-1:1000 (v:v). Mean (+/- SEM) fresh (f.wt.) and dry weights (d.wt.) of cells after 25 d of culture were significantly (p <.05) greater in medium supplemented with 1:750 and 1:1000 (v:v) Erythrogen, compared to controls lacking Erythrogen. For example, with 1:750 (v:v) Erythrogen, mean cell f.wt. and d.wt. were increased by 45 and 31%, respectively. Total soluble cellular protein increased by 141, 176, and 191% with Erythrogen at 1:50, 1:750, and 1:1000 (v:v), respectively. Cellular catalase and glutathione reductase activities decreased significantly (p <.05) following addition of low concentrations (1:1000 and 1:750 v:v) of Erythrogen to culture medium. However, increasing the concentration of Erythrogen to a maximum of 1:100 (v:v), caused a concomitant increase in catalase to a maximum of 62% over control. Mean total superoxide dismutase activity increased linearly with increasing Erythrogen concentration, reaching a maximum mean value over 2-fold greater than control with 1:100 (v:v) Erythrogen. A similar trend was observed in cellular H2O2 content, which reached a maximum of 98% over control with 1:250 (v:v) Erythrogen. These results demonstrate that culture of cotton cells with Hb solution causes changes in cellular oxygenation sufficient to modify cellular antioxidant status.

Animals↗
PubMed2001

Beneficial effects of Pluronic F-68 and artificial oxygen carriers on the post-thaw recovery of cryopreserved plant cells.

The storage of prokaryotic and eukaryotic cells at ultra-low temperature in liquid nitrogen (-196 degrees C) is a procedure that has assumed an increasingly important role in underpinning many aspects of biotechnology. For eukaryotic cells, the transition from a cryopreserved state to physiologically normal temperatures and oxygen tensions, induces respiratory imbalances that may stimulate the production of toxic oxygen radicals causing impaired cellular functions. Novel treatments, that focus specifically on enhancing oxygen delivery to cells, are important in maximising post-thaw recovery. Recently, several approaches have been evaluated with suspension cultured plant cells as a model, yet biotechnologically-important, totipotent eukaryotic cell system. Such treatments include non-ionic surfactants, primarily Pluronic F-68, and artificial oxygen carriers, the latter based on inert perfluorochemical liquids or chemically-modifed haemoglobin, as supplements to culture medium used during the post-thaw recovery phase of cell growth. When used either alone or in combination, such novel treatments stimulate significantly the post-thaw viability and biomass production of cultured plant cells. Many of these technologies will be exploitable in cryopreservation protocols for eukaryotic cells in general.

Animals↗
PubMed2001

Pluronic F-68 enhanced shoot regeneration in a potentially novel citrus rootstock.

The effects have been studied in vitro of the non-ionic, co-polymer surfactant, Pluronic F-68, on shoot regeneration and bud induction in epicotyl and cotyledon explants of Citrus depressa, a potential alternative rootstock to C. jambhiri for commercial Citrus. Supplementation of Murashige and Skoog (1962)-based, agar-solidified shoot regeneration/bud induction (SRBI) medium with 1.0 mg l(-1) 6-benzylaminopurine and 0.5% (w/v) Pluronic F-68 significantly (P < 0.05) increased mean fresh weight by a maximum of 60%, the proportion of explants exhibiting shoot/bud regeneration by 25% and the mean number of shoots per epicotyl explant by 184%, compared to untreated controls. Similarly, 0.5% (w/v) Pluronic F-68 significantly (P < 0.05) enhanced the mean percentage bud induction (91%) and the number of buds regenerated (>4-fold) per cotyledon explant. Interestingly, the mean fresh weight gain for both explants was unaffected across the range of concentrations (0.001-0.1% w/v) of Pluronic F-68 evaluated. Regenerated plants from epicotyl explants were transferred and acclimatized to glasshouse conditions.

Biomass↗
PubMed2001

Haemoglobin (Erythrogen) enhanced microcallus formation from protoplasts of Indica rice (Oryza sativa L.).

The beneficial effects have been studied of supplementing culture medium with 1:100-1:500 (v:v) of a commercial haemoglobin solution (Erythrogen) on the mitotic division of cell suspension-derived protoplasts of Indica rices (Oryza sativa L.). Protoplasts were cultured in liquid medium, at densities of 1.5 x 10(6) or 2.5 x 10(6) ml(-1), on nitrocellulose membranes overlaying a semi-solidified medium layer that was supplemented with both Erythrogen and nurse cells of Lolium multiflorum. The mean final plating efficiencies (FPEs) of rice cv. BR26 protoplasts cultured with 1:200 (v:v) Erythrogen, at 1.5 x 10(6) ml(-1) (0.018+/-0.003%; n = 8) and 2.5 x 10(6) ml(-1) (0.016+/-0.002%; n = 8), were both significantly (P < 0.05) greater than controls lacking Erythrogen (0.0058+/-0.002%; n = 8 and 0.0041+/-0.001%; n = 8, respectively). Similarly, the mean FPEs of cv. Bini protoplasts cultured with 1:200 (v:v) Erythrogen at 1.5 x 10(6) ml(-1) (0.012+/-0.003%; n = 6) and 2.5 x 10(6) ml(-1) (0.017+/-0.001%; n = 6) were also significantly (P < 0.05) greater than their respective controls (0.003+/-0.001%, n = 6 and 0.002+/-0.001%, n = 6). In contrast, supplementation with 1:100 or 1:500 (v:v) Erythrogen did not lead to sustained mitotic division and microcallus formation in both rice cultivars.

Cell Culture Techniques↗
PubMed2000

Viability of plant cell suspensions exposed to homogeneous ultrasonic fields of different energy density and wave type.

Exposure of Petunia hybrida cell suspensions to ultrasound at a frequency of 2.43 MHz in a standing wave field at an energy density of 70 Jm-3 (pressure amplitude of 0.78 MPa) decreased their mean viability to 35% after 20 min of sonication. A comparison of propagating wave and standing wave treatments at equal frequency (2.15 MHz) and energy density (8.5 Jm-3) showed, in the first case, a rapid decline in mean viability of cells (to 30% after 10 min of sonication) and, in the second case, a retaining of the initial viability (95%), respectively. Cells sonicated 4 days after subculture were more sensitive than cells sonicated 2 or 6 days after transfer to new culture medium. It was concluded that cellular viability depends primarily on the acoustic energy density, the exposure time, and the mechanical properties of the cells determined by age. As a consequence of the trapping of cells in the anti-node planes of the standing wave, propagating wave fields reduced cellular viability compared with standing wave fields at equal energy density.

Cell Survival↗
PubMed2000

Service user involvement in care planning: the mental health nurse's perspective.

A dissonance between espoused values of consumerism within mental health care and the 'reality' of clinical practice has been firmly established in the literature, not least in terms of service user involvement in care planning. In order to begin to minimize such dissonance, it is vital that mental health nurse perceptions of service user involvement in the core activity of care planning are better understood. The main findings of this qualitative study, which uses semistructured interviews, suggest that mental health nurses value the concept of user involvement but consider it to be problematic in certain circumstances. The study reveals that nurses hold similar views about the 'meaning' of patient involvement in care planning but limited resources, individual patients characteristics and limitations in nursing care are the main inhibiting factors. Factors perceived as promoting and increasing user involvement included: provision of accurate information, 'user-friendly' documentation, mechanisms for gaining service user feedback, and high staff morale.

Health Planning↗
PubMed1999

Burden of caregiving in mild to moderate dementia: an Asian experience.

This survey sought to determine (a) the prevalence of carer stress in patients with mild to moderate dementia, (b) whether caregiver burden was already associated with plans to institutionalize patients, and (c) which patient-related and caregiver-related variables best predicted caregiver burden. The principal caregivers of 93 Asian patients with mild to moderate dementia attending an outpatient cognitive assessment clinic were interviewed via a structured questionnaire that focused upon (a) patient-related variables such as their behavioral and functional abnormalities; and (b) caregiver-related variables such as whether they were having problems looking after the patients, the duration of their caregiving, their associated feelings of anger and/or depression, and their financial status as well as intentions to institutionalize patients. Forty-nine percent of caregivers reported problems in looking after the patients, and their perception of difficulties was significantly associated with institutionalization plans for the patients. Logistic regression analysis using a forward variable selection procedure showed two of the patients' behavioral abnormalities (repetition, agitation) and one of their functional impairments (urinary incontinence) as well as the carers' depressed feelings to be predictive of the carers' problematic status, explaining 40% of the variance. It is important that even in the early stages of dementia, the medical assessment also evaluate behavioral, functional, and social dimensions of the illness, so that appropriate interventions can be implemented to reduce caregiving burden and delay institutionalization.

Aged↗
PubMed1999

Magnetic resonance imaging techniques demonstrate soft tissue damage in the diabetic foot.

AIMS: Our objective was to assess the qualitative soft tissue changes which occur in the diabetic neuropathic foot, which may predispose to ulceration, using a specific magnetic resonance imaging (MRI) contrast sequence, magnetization transfer (MT) which produces contrast based on exchange between water bound to macromolecules (e.g. collagen) and free water (e.g. extracellular fluid). METHODS: The first metatarsal head of 19 diabetic neuropathic subjects and 11 diabetic non-neuropathic controls was studied using a 'targeted' radiofrequency coil. Neuropathy was classified using vibration perception threshold (VPT) (< or > 25 V), cold threshold (< 1 degree C or > 4 degrees C) and Michigan neuropathy score (< 5 or > 15). Peripheral vascular disease was excluded. Results were expressed as percentage of tissue MT activity in a cross-sectional area. At autopsy full thickness biopsies were taken from the plantar fat pad of 10 unrelated subjects with diabetic neuropathy. RESULTS: Healthy muscle displays high MT activity, whereas adipose tissue induces little activity. Muscle MT activity was considerably reduced (75+/-20%, 30+/-24%, P<0.001) and fat pad MT activity was considerably increased in subjects with neuropathy (37+/-17% 68+/-21%, P<0.001). Muscle fibre atrophy decreases MT activity, whereas fibrous infiltration of the fat pad increases MT activity, fibro-atrophic post-mortem histological changes were found in the plantar fat pads of all neuropathic subjects examined (n = 10). CONCLUSIONS: Changes in MT activity reflect qualitative structural changes which this study reveals are extensive in the diabetic neuropathic foot. Fibrotic atrophy of the plantar fat pad may affect its ability to dissipate the increased weight-bearing forces associated with diabetic neuropathy.

Adipose Tissue↗
PubMed1999

Haemoglobin (Erythrogen)-enhanced post-thaw growth of cryopreserved cells.

Supplementation of semi-solid R2 culture medium with a commercial bovine haemoglobin (Hb) solution (Erythrogen) at 1:50-1:500 (v:v), had beneficial effects on the growth, following cryopreservation, of cells of the Indica rice, Oryza sativa cv. Pusa Basmati 1. The mean absorbance, as assessed by triphenyl tetrazolium chloride reduction, of rice cells at 8 d post-thawing, was increased by up to 60% (P < 0.05), compared to cells recovered in the absence of Hb. Erythrogen (1:50-1:500 v:v) promoted an increase in biomass, of up to 25% over control (P < 0.05), at 24 d post-thawing. Cell suspensions, re-established by transfer to liquid medium of cells initially thawed and cultured with Erythrogen for 24 d, exhibited increased (up to 2-fold) growth rates over a subsequent 20-d period, compared to cells recovered without Hb.

Cells, Cultured↗
PubMed1999

Culture of cells at perfluorocarbon-aqueous interfaces.

Protoplasts (wall-less cells) isolated enzymatically from leaf tissues of Manihot esculenta, Passiflora edulis and Petunia parodii, and from cell suspensions of Oryza sativa, Passiflora giberti, Petunia hybrida and Salpiglossis sinuata, were cultured for up to 35 d at an interface between the inert, oxygen-gassed perfluorocarbon (PFC) liquid, perfluorodecalin, overlaid with liquid or semi-solidified aqueous media. The maximum increase in mitotic division, as assessed by initial plating efficiency (IPE) occurred with protoplasts of O. sativa, which showed a 4-fold increase above the control over 35 d. Similar, but less pronounced increases in IPE of 90-103% occurred with S. sinuata, P. giberti and P. parodii following culture with oxygenated PFC. The least responsive species was M. esculenta, where the mean IPE after 25 d was increased by 33% over control. For those totipotent protoplast systems (e.g. P. edulis, P. giberti, O. sativa and P. parodii) phenotypically normal plants were regenerated following initial culture with oxygenated PFC. The advantages of such an interface system include (1) ease of sterilisation of the PFC by autoclaving, (2) the recycleability and, hence, recovery of the PFC, thereby offsetting the high initial costs, and (3) the ability to aspirate cells at the interface.

Cell Culture Techniques↗
PubMed1998

The development of Healthcare Resource Groups--Version 3.

The use of casemix classifications to assist in the analysis of patient-based information is becoming more widespread and routine in the management of the National Health Service (NHS). This paper details the process of modification of and the results of modifications to Healthcare Resource Groups (HRGs), an in-patient classification tailor-made for the English healthcare system. Clinical expertise and extensive statistical analysis of national data were combined to identify areas of HRGs Version 2 where improvement could be made. The ensuing changes were then reviewed by professional associations and the wider NHS before being incorporated into grouping software. Extensive changes were made to the classification, with significant gains in statistical performance. Analysis shows that the revised groupings perform better on English data than other available systems.

Diagnosis-Related Groups↗
PubMed1998

Enhanced mitosis in cultured protoplasts: beneficial effects of oxygenated perfluorocarbon and haemoglobin.

Cell suspension-derived protoplasts of Petunia hybrida cv. Comanche were cultured for up to 10 d in (1) aqueous medium, (2) aqueous medium overlaying an oxygenated (10 mbar, 15 min) perfluorochemical liquid (perfluorodecalin; PFC), (3) aqueous medium containing 1:50 (v:v) of the commercial haemoglobin (Hb) solution (Erythrogen), (4) aqueous medium supplemented with 1:50 (v:v) of Erythrogen overlaying oxygenated PFC. Treatments 2, 3, and 4 enhanced mean mitotic division by 111%, 80% and 139% respectively, compared to controls. Both fresh-Hb and stored-Hb significantly (P < 0.05) enhanced mitotic division, although this was 45% greater with fresh-Hb compared to stored-Hb. Both oxygenated PFC and Erythrogen provide approaches for enhancing cellular oxygen supply to eukaryotic cells. Commercially, the recoverability and recycleability of PFCs make these compounds a more attractive option in comparison to Erythrogen, despite a high initial investment cost.

Animals↗
PubMed1998

Enhanced post-thaw viability of cryopreserved cells by oxygenated perfluorocarbon or Pluronic F-68.

Viability and growth following cryopreservation have been examined following (i) culture of Oryza sativa cv. Taipei 309 (Japonica rice) in medium overlaying oxygenated perfluorocarbon (PFC) liquid (Flutec PP6), and (ii) culture of two cvs. of Japonica rice (Taipei 309, Tarom), and Lolium multiflorum in media with Pluronic F-68 (0.01-0.2% w/v). The mean viability of cv. Taipei 309 rice cells following 4 days in medium overlaying oxygenated Flutec (0.45 +/- 0.07; n = 20) was significantly (P < 0.05) greater than control (0.35 +/- 0.08). Cell viability of cv. Tarom was increased by 400% (P < 0.001) with 0.1% (w/v) Pluronic F-68 in the recovery medium. Mean cell viability was also elevated 3-fold (P < 0.001) and 2-fold (P < 0.05) with 0.2% (w/v) and 0.01% (w/v) Pluronic, respectively. A 2-fold increase (P < 0.001) in viability occurred for Taipei 309 cells exposed to 0.01% (w/v) Pluronic F-68; that of Lolium cells was increased by 31% (P < 0.01) under similar conditions. Pluronic F-68 (0.01% w/v) also stimulated biomass, by 29-32%, in both cvs. Taipei 309 and Lolium at 30 days post-thawing.

Biomass↗