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Biomedical subjects

A A Webb

Publications and source records attributed to A A Webb.

At least 19 recordsLinked to original sources
PubMed2004

Behavioural analysis of the efficacy of treatments for injuries to the spinal cord in animals.

There have been very few clinical trials evaluating therapies for naturally occurring spinal cord injury in dogs and cats. This review describes the methods suitable for evaluating the behavioural recovery of animals with spinal cord injuries, in either a clinical or a laboratory setting. A list of commonly used methods for evaluating behavioural recovery in animals is provided, both in the clinical and laboratory setting; the tests, their limitations and benefits and specific recommendations for their use are also discussed in more depth.

Animals↗
PubMed2001

The role of calcium in ABA-induced gene expression and stomatal movements.

There is much interest in the transduction pathways by which abscisic acid (ABA) regulates stomatal movements (ABA-turgor signalling) and by which this phytohormone regulates the pattern of gene expression in plant cells (ABA-nuclear signalling). A number of second messengers have been identified in both the ABA-turgor and ABA-nuclear signalling pathways. A major challenge is to understand the architecture of ABA-signalling pathways and to determine how the ABA signal is coupled to the appropriate response. We have investigated whether separate Ca2+-dependent and -independent ABA-signalling pathways are present in guard cells. Our data suggest that increases in [Ca2+]i are a common component of the guard cell ABA-turgor and ABA-nuclear signalling pathways. The effects of Ca2+ antagonists on ABA-induced stomatal closure and the ABA-responsive CDeT6-19 gene promoter suggest that Ca2+ is involved in both ABA-turgor signalling and ABA-nuclear signalling in guard cells. However, the sensitivity of these pathways to alterations in the external calcium concentration differ, suggesting that the ABA-nuclear and ABA-turgor signalling pathways are not completely convergent. Our data suggest that whilst Ca2+-independent signalling elements are present in the guard cell, they do not form a completely separate Ca2+-independent ABA-signalling pathway.

Abscisic Acid↗
PubMed2001

Audit of a multidisciplinary approach to the care of children with unilateral and bilateral cleft lip and palate.

Cleft lip and palate affects the child in many ways, particularly appearance, dental arch relationships, growth of the face, and speech development. The key to successful care is management in a multidisciplinary team adhering to a well-designed protocol, and careful audit of results. We present the intermediate outcome audit of 15 patients with complete bilateral and unilateral cleft lip and palate whose condition was managed in a multidisciplinary team according to a strict protocol. We give the results observations of operations of a single surgeon's functional primary surgery over a 6-year period in terms of dental arch relationships, cephalometric analyses, aesthetic assessments, and speech analysis. The results show good early facial growth, with dental arch relationships appropriate for the age and group; we found only minor speech discrepancies, with no patients requiring pharyngoplasty. The results show the importance of multidisciplinary management, the value of keeping to sound surgical protocols, and functional techniques in cleft lip and palate surgery. Our study includes the neglected group of children who have bilateral cleft lip and palate, and it conforms to the style of pan-European projects.

Cephalometry↗
PubMed2001

Surgical management of cutaneous squamous cell carcinoma of the head and neck.

A retrospective audit was made of histological records and hospital case notes of patients who had cutaneous squamous cell carcinomas excised from the head and neck region at the Maxillofacial Units at St Richard's Hospital, Chichester and Southlands Hospital, Shoreham-By-Sea, UK. A total of 227 lesions were excised from 183 patients over a 5-year period between 1990 and 1995. The local recurrence rate was 4% (9/227) and 12 (7%) of the patients presented with or developed regional nodal metastases. Of the 183 patients, 177 (97%) were cured. These rates compare favourably with those of other published series of cutaneous squamous cell carcinoma managed by surgical techniques that did not follow the micrographical technique of Mohs. Certain characteristics may aid in the prediction of those cancers that may be more aggressive. It is important to evaluate each case in terms of histological grade and site and to design management plans to deal with each lesion in the most appropriate way.

Aged↗
PubMed2000

Mini-review: assessment of behavioural recovery following spinal cord injury in rats.

Behavioural recovery is one of the primary goals of therapeutic intervention in animal models of disease. It is necessary, therefore, to have the means with which to quantify pertinent behavioural changes in experimental animals. Nevertheless, the number and diversity of behavioural measures which have been used to assess recovery after experimental interventions often makes it difficult to compare results between studies. The present review attempts to integrate and categorize the wide variety of behavioural assessments used to measure recovery in spinal-injured rats. These categories include endpoint measures, kinematic measures, kinetic measurements, and electrophysiological measurements. Within this categorization, we discuss the advantages and disadvantages of each type of measurement. Finally, we make some recommendations regarding the principles for a comprehensive behavioural analysis after experimental spinal cord injury in rats.

Animals↗
PubMed1999

Skin care of the pediatric patient.

Several factors influence the chronically ill child's susceptibility for skin breakdown. Nurses are an integral part of the care team that has the responsibility for identification of these factors, as well as pressure ulcer prevention and early intervention. An important aspect of this responsibility is identification of individuals at risk. This article provides a guide for assessment and early intervention for skin breakdown in chronically ill children. A care plan and consultation recommendations are included.

Adolescent↗
PubMed1999

ABI1 protein phosphatase 2C is a negative regulator of abscisic acid signaling.

The plant hormone abscisic acid (ABA) is a key regulator of seed maturation and germination and mediates adaptive responses to environmental stress. In Arabidopsis, the ABI1 gene encodes a member of the 2C class of protein serine/threonine phosphatases (PP2C), and the abi1-1 mutation markedly reduces ABA responsiveness in both seeds and vegetative tissues. However, this mutation is dominant and has been the only mutant allele available for the ABI1 gene. Hence, it remained unclear whether ABI1 contributes to ABA signaling, and in case ABI1 does regulate ABA responsiveness, whether it is a positive or negative regulator of ABA action. In this study, we isolated seven novel alleles of the ABI1 gene as intragenic revertants of the abi1-1 mutant. In contrast to the ABA-resistant abi1-1 mutant, these revertants were more sensitive than the wild type to the inhibition of seed germination and seedling root growth by applied ABA. They also displayed increases in seed dormancy and drought adaptive responses that are indicative of a higher responsiveness to endogenous ABA. The revertant alleles were recessive to the wild-type ABI1 allele in enhancing ABA sensitivity, indicating that this ABA-supersensitive phenotype results from a loss of function in ABI1. The seven suppressor mutations are missense mutations in conserved regions of the PP2C domain of ABI1, and each of the corresponding revertant alleles encodes an ABI1 protein that lacked any detectable PP2C activity in an in vitro enzymatic assay. These results indicate that a loss of ABI1 PP2C activity leads to an enhanced responsiveness to ABA. Thus, the wild-type ABI1 phosphatase is a negative regulator of ABA responses.

Abscisic Acid↗
PubMed1999

Intravenous regional anesthesia (Bier block) in a dog.

Intravenous regional anesthesia was used in an adult dog as part of a balanced approach to general anesthesia for amputation of the 4th digit of its right hind limb. It allowed the concentration of isoflurane to be reduced to 0.5%.

Amputation, Surgical↗
PubMed1999

Intradural spinal arachnoid cyst in a dog.

An 8-month-old, spayed female dog was presented with signs localizing a neurologic lesion between the 3rd thoracic and 3rd lumbar vertebrae. An arachnoid cyst was diagnosed by myelography, and a dorsal laminectomy with durotomy was performed. The dog continues to do well 1-1/2 year after surgery.

Animals↗
PubMed1998

Re-evaluation of i.m. ephedrine as prophylaxis against hypotension associated with spinal anaesthesia for Caesarean section.

PURPOSE: To assess the safety and efficacy of 37.5 mg ephedrine i.m. in preventing hypotension associated with spinal anaesthesia for Caesarean section. METHODS: In a double-blind randomised controlled study, 40 patients (20 in each group) were given either 37.5 mg ephedrine or placebo i.m. The following parameters were recorded: (i) blood pressure; (ii) heart rate; (iii) ephedrine i.v. supplementation; (iv) umbilical venous blood gases and neonatal Apgar scores. RESULTS: The incidence of hypertension in the study group was 30% compared with 20% for the control group (P:NS). There was no difference in mean highest blood pressure or mean highest heart rate between the groups. The incidence of hypotension was lower but not significantly lower in the study group (50%) than in the control group (80%) (P:NS). However, the incidence of delayed hypotension was only 10% in the study group patients compared with 50% in the control group patients (P < 0.05). CONCLUSION: Giving 37.5 mg ephedrine i.m. prior to spinal anaesthesia was not associated with reactive hypertension or tachycardia. Intramuscular ephedrine provided more sustained cardiovascular support than intravenous ephedrine.

Anesthesia, Obstetrical↗
PubMed1998

The short-period mutant, toc1-1, alters circadian clock regulation of multiple outputs throughout development in Arabidopsis thaliana.

The coordination of developmental and physiological events with environmental signals is facilitated by the action of the circadian clock. Here we report a new set of circadian clock-controlled phenotypes for Arabidopsis thaliana. We use these markers together with the short-period mutant, toc1-1, and the clock-controlled cab2::luciferase reporter gene to assess the nature of the circadian clock throughout development and to suggest the position of TOC1 within the circadian clock system. In dark-grown seedlings, the toc1-1 lesion conferred a short period to the cycling of cab2::luciferase luminescence, as previously found in light-grown plants, indicating that the circadian clocks in these two divergent developmental states share at least one component. Stomatal conductance rhythms were similarly approximately 3 hours shorter than wild type in toc1-1, suggesting that a cell-autonomous clockwork may be active in guard cells in 5- to 6-week-old leaves. The effect of daylength on flowering time in the C24 ecotype was diminished by toc1-1, and was nearly eliminated in the Landsberg erecta background where the plants flowered equally early in both short and long days. Throughout a 500-fold range of red light intensities, both the wild type and the mutant showed an inverse log-linear relationship of fluence rate to period, with a 2-3 hour shorter period for the mutant at all intensities. These results indicate that TOC1 acts on or within the clock independently of light input. Temperature entrainment appears normal in toc1-1, and the period-shortening effects of the mutant remain unchanged over a 20 degrees C temperature range. Taken together our results are consistent with the likelihood that TOC1 codes for an oscillator component rather than for an element of an input signaling pathway. In addition, the pervasive effect of toc1-1 on a variety of clock-controlled processes throughout development suggests that a single circadian system is primarily responsible for controlling most, if not all, circadian rhythms in the plant.

Arabidopsis↗
PubMed1997

Focal myasthenia gravis in a dog.

A 10-month-old American cocker spaniel was evaluated for megaesophagus, aspiration pneumonia, but no appendicular muscle weakness. During hospitalization, weakness of the facial muscles developed, this resolved with anticholinesterase administration. Serum antibodies against acetylcholine receptors were documented, confirming the diagnosis of focal myasthenia gravis. Diagnosis, management, and medical treatment are discussed.

Animals↗
PubMed1995

ABA-regulated promoter activity in stomatal guard cells.

CDeT6-19 is an ABA-regulated gene which has been isolated from Craterostigma plantagineum. The CDeT6-19 gene promoter has been fused to the beta-glucuronidase reporter gene (GUS) and used to stably transform Arabidopsis thaliana and Nicotiana tabacum. This construct has been shown to be expressed in stomatal guard cells and often in the adjacent epidermal cells of both species in response to both exogenous ABA and drought stress. These results indicate that the stomatal guard cell is competent to relay an ABA signal to the nucleus. In contrast GUS expression directed by the promoter from a predominantly seed-specific, ABA-regulated gene, Em, or the promoter from the ABA-regulated CDeT27-45 gene is not detectable in the epidermal or guard cells of tobacco or Arabidopsis in response to ABA. The fact that not all ABA-regulated gene promoters are active in stomatal guard cells suggests that effective transduction of the signal is dependent upon particular regions within the gene promoter or that guard cells lack all or part of the specific transduction apparatus required to couple the ABA signal to these promoters. This suggests that there are multiple ABA stimulus response coupling pathways. The identification of a regulatory sequence from an ABA-induced gene which is expressed in stomatal guard cells creates the possibility of examining the role of Ca2+ and other second messengers in ABA-induced gene expression.

Abscisic Acid↗
PubMed1994

Nursing students' knowledge and anxiety about AIDS: an experimental workshop.

The purpose of this quasiexperimental study was to examine the effectiveness of an experiential workshop on nursing students' anxiety and knowledge about AIDS. This study was based on Peplau's interpersonal theory in nursing practice. The sample included 67 senior nursing students and was designed as a three-group pre/post quasiexperiment. All groups received a pretest, posttest, and 6-week follow-up posttest. The experimental intervention was a 6-hour workshop that included anxiety awareness exercises in an experiential format and information about AIDS. Knowledge and anxiety scores were significantly higher for the group that attended the didactic portion of the workshop before the experiential portion. The control group showed no change in knowledge or anxiety. Results indicated that recognition of anxiety through experiential exercises contributed to learning about AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Six years after an economic crisis: child's anxiety and quality of peer relationships.

The purpose of this 6-year follow-up study was to determine whether there is a long-term relationship between economic stress and childrens' anxiety and peer-related behaviors. Data were collected from 39 of the 52 families in the original study. Analysis resulted in several interesting findings. Economic stress in 1983 was a moderate predictor of state anxiety, trait anxiety, and peer rejection in girls in 1989. Descriptive evidence was provided to indicate that detrimental effects of economic stressors on the family as a unit continue beyond the initial stress event. Implications for community health nurses (CHNs) are addressed.

Child↗