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Biomedical subjects

M Powell

Publications and source records attributed to M Powell.

At least 109 records · Page 6Linked to original sources
PubMed1991

Sudden infant death syndrome: a crisis for parents and health professionals.

A study of the social impact of Sudden Infant Death Syndrome (SIDS) in 40 families in Ireland (40 mothers: 29 fathers and 78 siblings) revealed a profound influence on family function. Less than half the parents felt an acceptance of the loss at a mean interim of 2.9 years post SIDS. Family dysfunction was manifested by marital problems and prolonged grief reactions. Interpersonal support through family, friends, relatives or neighbours appropriately assisted a third of families. Medical information when provided to parents contributed to a more normal grief process, but lack of postmortem information contributed to pathological or unresolved guilt in a third of parents and anger in nearly half the sample. Health professional and voluntary aftercare at community level was inconsistent in meeting parents' need for information, advice and support. A primary, preventive health care approach, based on a co-ordinated policy of aftercare to SIDS families, at hospital and community level is recommended to facilitate parents' resolution of grief, and counteract the onset of adverse psychosocial effects.

Adult↗
PubMed1991

Chronic pain: a PET study of the central effects of percutaneous high cervical cordotomy.

We have studied 5 patients with unilateral, severe chronic pain due to cancer before and after percutaneous, ventrolateral cervical cordotomy to investigate the central effects of the procedure. The aim was to identify the functional anatomical correlates of abolishing unilateral nociceptive input to the brain. Patients were investigated by positron emission tomography using C15O2 to evaluate cerebral blood flow. Comparisons were made between the patients with unilateral pain before cordotomy and normal volunteers. These demonstrated significantly less blood flow in 3 out of 4 of the individual quadrants of the hemithalamus contralateral to the side of pain (P less than 0.01-0.05). These differences were abolished by cordotomy. Comparison of the patients before and after cordotomy showed a significant decrease in blood flow in the dorsal anterior quadrant of the thalamus contralateral to the side of pain (P less than 0.05) which was normalised after cordotomy. There were no significant changes in the prefrontal or primary somatosensory cortex. We conclude that chronic pain results in a decrease of synaptic activity at thalamic level either from decreased activity in neurones projecting to that region and/or attenuated local neuronal firing. We have demonstrated no secondary remote effects in cortex, indicating the importance of subcortical mechanisms in central responses to chronic pain.

Aged↗
PubMed1991

Antimicrobial susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis isolated in the UK from sputa.

Four hundred and thirty-one Streptococcus pneumoniae, 1272 Haemophilus influenzae and 305 Moraxella (Branhamella) catarrhalis were isolated from sputa and identified in 28 UK laboratories during a ten week period in 1990. Disc diffusion susceptibility testing was performed in each centre using identical methods. Species-specific susceptibility breakpoints applied to data for six antimicrobial agents were determined from the distribution of isolates according to zone diameters of inhibition measured in participating laboratories and were correlated with minimum inhibitory concentration data obtained with 302 isolates sent to the coordinating centre. Inter-laboratory reproducibility was estimated by comparing peripheral and coordinating centre results for these 302 isolates and by distributing five reference strains to all laboratories for testing. Reduced susceptibility to ampicillin and amoxycillin-clavulanate was detected in less than 3% of S. pneumoniae, but 8.1% were resistant to tetracycline and 6.5% to erythromycin. Resistance to ampicillin due to production of beta-lactamase occurred in 9.4% of H. influenzae; another 5.2% were resistant to ampicillin and amoxycillin-clavulanate but were beta-lactamase-negative. 4.5% were resistant to tetracycline and most (86.6%) had MICs greater than or equal to 1 mg/L of erythromycin. Zone diameters around ampicillin discs were greater than or equal to 10 mm smaller than those around amoxycillin-clavulanate discs for 241 (79%) of M. catarrhalis. Although only 193/241 had been reported to be beta-lactamase positive by participating laboratories, data obtained at the coordinating centre confirmed that greater than or equal to 10 mm and less than or equal to 3 mm zone size differences correlated with beta-lactamase-positive and -negative isolates respectively. No M. catarrhalis were resistant to amoxycillin-clavulanate and less than 4% were resistant to either tetracycline or erythromycin. The prevalence of resistance to cefaclor was highest among H. influenzae (5.2%) and lowest among S. pneumoniae (0.9%). Only seven of 2008 isolates (two to three per species) were resistant to cefixime. The data suggest that the prevalence of resistance to ampicillin, tetracycline and erythromycin must be taken into consideration when treating respiratory infections.

Ampicillin Resistance↗
PubMed1991

Rapid electrochemiluminescence assays of polymerase chain reaction products.

We demonstrate the first use of an electrochemiluminescent (ECL) label, [4-(N-succimidyloxycarbonylpropyl)-4'-methyl-2,2'- bipyridine]ruthenium(II) dihexafluorophosphate (Origen label; IGEN Inc.), in DNA probe assays. This label allows rapid (less than 25 min) quantification and detection of polymerase chain reaction (PCR)-amplified products from oncogenes, viruses, and cloned genes. For the PCR, we used labeled oligonucleotide primers complementary to human papiloma virus and the Ha-ras oncogene. These samples were followed by ECL analysis or hybridization with specific, Origen-labeled oligonucleotide probes. These studies demonstrate the speed, specificity, and effectiveness of the new ECL labels, compared with 32P, for nucleic acid probe applications. We describe formats involving conventional methodologies and a new format that requires no wash step, allowing simple and rapid sample analysis. These rapid assays also reduce PCR contamination, by requiring less sample handling. Improvements in ECL detectability are currently under investigation for use in DNA probe assays without amplification.

2,2'-Dipyridyl↗
PubMed1990

Cavernous sinus involvement in recurrent Nelson's syndrome.

Nelson's syndrome is rare and difficult to cure. The tumours in this condition may behave invasively and require multiple interventions. Two patients who had been followed up for nearly 20 years developed signs of cavernous sinus involvement, one with an empty sella. Long term follow-up for such patients is emphasized.

Adult↗
PubMed1990

A day in the life of an inpatient: an experiential game to promote empathy for individuals in a psychiatric hospital.

The attitudes of hospital staff toward individuals with mental illness have been investigated, described in the literature, and discussed at national conferences. It has been suggested that attitudes are the precursors or determinants of behavior. Although the precise effect of staff attitude on patients is unclear, attitudes of the staff do appear to be related to their behavior and to have an impact on patients and their subsequent recovery. There are few precise answers on how to promote positive attitudes. While hospital policies and procedures can prescribe behaviors of staff, attitude cannot be dictated. Some studies have evaluated the effect of training and participation in milieu programs on the attitude of psychiatric staff. Simulation games recently have been explored as a possible way to influence the attitude of staff toward those with mental illness. This article describes an attempt at one state psychiatric hospital to influence in a positive way the attitude of the staff by using a simulation game called, A Day in the Life of an Inpatient. Adapted from Into Aging by Hoffman and Reif (1978), the game used by the authors provides a microcosmic experience for staff of a hospitalized patient's ward experience.

Empathy↗
PubMed1990

Antibacterial and mutagenic activity of inhaled bronchodilators on the respiratory pathogen Haemophilus influenzae.

The U.K. prevalence of non-beta-lactamase-mediated resistance to ampicillin among Haemophilus influenzae reached 4% in 1986. The majority (70%) of isolates of this type come from sputa of patients with chronic obstructive airways disease. This study investigated whether bronchodilator drugs delivered directly to the respiratory tract have any antibacterial activity and/or play a role in promoting selection of organisms with this type of resistance. Antibacterial activity was detected in two out of six pharmaceutical preparations for nebulization examination but was entirely attributable to the preservative (benzalkonium chloride) in them. Exposure of ampicillin-susceptible H. influenzae (minimum inhibitory concentration 0.25 mg l-1) to concentrations of salbutamol, fenoterol and beclomethasone theoretically attainable in vivo resulted, after 48 h, in isolation of colonies with reduced susceptibility to ampicillin (minimum inhibitory concentration 1-4 mg l-1) but reversion to beta-lactam susceptibility occurred following serial subculture on chocolate agar. Organisms with stable reduced susceptibility to ampicillin were obtained when exposure to one of these three bronchodilators in broth was followed by serial subculture on agar containing the same preparations at equivalent concentrations and when the period of exposure to salbutamol at 100 mg l-1 in broth was extended to 5 days. The occurrence of these phenomena in vivo might be contributing to failures in treatment of exacerbations with ampicillin and to an increasing prevalence of beta-lactamase-negative, ampicillin-resistant H. influenzae.

Ampicillin↗
PubMed1990

Selection and transformation of non-beta-lactamase-mediated insusceptibility to beta-lactams in Haemophilus influenzae: lack of cross-resistance between carbapenems and other agents.

Non-beta-lactamase-mediated insusceptibility to beta-lactams was studied in Haemophilus influenzae. Mutants resistant to ampicillin were selected in a susceptible isolate, while phenotypically similar resistance was transformed from four wild-type isolates into a susceptible recipient. Ampicillin-selected mutants generally had reduced susceptibility to penicillins, cephalosporins and aztreonam. Reduced susceptibility to meropenem was less common, and susceptibility to imipenem was unaffected. MICs of three cephalosporins and aztreonam were much higher for the ampicillin-resistant transformants than for the recipient strain, and were generally equal to, or within one doubling dilution of, the concentrations that inhibited the donor parents. In contrast, reduced susceptibility to imipenem observed with one parent (MIC of 4 mg/l) was not transferred to the recipient (MIC of 0.5 mg/l). Meropenem inhibited 22 of 24 transformants tested at less than or equal to 0.12 mg/l, compared with MICs of greater than or equal to 0.5 mg/l for the donor parents and 0.03 mg/l for the recipient. These results indicated that the mechanisms that confer non-beta-lactamase-mediated insusceptibility to penicillins, cephalosporins and aztreonam in H. influenzae have little or no effect on susceptibility to carbapenems.

Ampicillin Resistance↗
PubMed1990

Need and provision of health visiting in the London district health authorities.

This paper considers the degree of equity associated with the delivery of health visiting in London, England. As is common in the National Health Service, it is argued that an area with a greater need for a service should get greater provision of that service. Different indices for measuring needs and resources are discussed. In particular, the vital distinction between measures of resource input and output is examined. The relationships between provision indices are discussed and then the associations between need and provision are examined. It is concluded that the implications for equity are unclear, as the magnitude of the correlations change depending on the choice of indices.

Community Health Nursing↗
PubMed1989

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History, 20th Century↗
PubMed1989

A longitudinal study of the prevalence of voice disorders in children from a rural school division.

In a mass screening of children ages 6-10 in a rural school division, 203 children were identified as showing a voice deviation. One year later a retesting of 178 of these children showed that 39.9% still showed a voice disorder. Four years later 50 of these children were still available in the same school system; 38% of them still showed a voice disorder. Virtually none of these children were referred to the otolaryngologist for an ENT evaluation or to the speech-language pathologist for voice rehabilitation. Results indicate that, for many of these children, the voice disorders do not "clear up" through maturation alone.

Child↗
PubMed1989

Influence of food on the absorption of albuterol Repetabs.

A study was conducted in 12 healthy, nonsmoking male volunteers to examine the effect of food intake on the absorption profile of albuterol repeat-action tablets. This randomized crossover study consisted of two phases separated by a 1-week washout period. All subjects fasted 10 hours preceding drug administration. Each subject received two 4 mg albuterol repeat-action tablets with and without a high fat content breakfast. Plasma albuterol concentrations were determined by a gas chromatographic/mass spectrophotometric assay. Relative bioavailability was assessed by comparing areas under the plasma-albuterol concentration time curves as well as peak concentrations and time to peak concentration. No significant differences were noted between the two treatment phases in the area under the curve or peak plasma concentrations. The areas under the curve were 100 and 105 hr.ng/ml when the drug was administered with and without food, respectively. The corresponding peak plasma concentration values were 9.4 and 10.4 ng/ml, respectively. The only significant difference observed was in the maximum time to reach peak plasma concentrations, which was delayed by about 1 hour when the drug was administered with food. Therefore, food has minimal effect on the absorption of albuterol from repeat-action tablets.

Adult↗