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Biomedical subjects

N Gibbs

Publications and source records attributed to N Gibbs.

At least 37 records · Page 2Linked to original sources

Safe Child Penarth: experience with a Safe Community strategy for preventing injuries to children.

OBJECTIVES: To evaluate the process of establishing a Safe Community project for children. DESIGN: A descriptive study. SETTING: Penarth, a town (population 20,430) Vale of Glamorgan, South Wales. SUBJECTS: 3943 children and their families in Penarth. MAIN OUTCOME MEASURES: Whether the 12 criteria for a Safe Community project (World Health Organisation) were met. Implementation of the safety agenda set by the community. RESULTS: Safe Child Penarth met 10 of the 12 criteria for the Safe Community network. All the items on the agenda were introduced in the initial two years of the project. There were difficulties, however, achieving sustained community ownership of the project. CONCLUSIONS: The Safe Community concept stimulated work to improve child safety in Penarth. Community safety initiatives should involve all local agencies to identify the problems and work with the community to set and meet the safety agenda. Partnership with the local authority is valuable to improve the safety of the environment. The experience generated from Safe Child Penarth has been used to develop a county wide, all age community safety project.

Accident Prevention↗

Helix bending in alamethicin: molecular dynamics simulations and amide hydrogen exchange in methanol.

Molecular dynamics simulations of alamethicin in methanol were carried out with either a regular alpha-helical conformation or the x-ray crystal structure as starting structures. The structures rapidly converged to a well-defined hydrogen-bonding pattern with mixed alpha-helical and 3(10)-helical hydrogen bonds, consistent with NMR structural characterization, and did not unfold throughout the 1-ns simulation, despite some sizable backbone fluctuations involving reversible breaking of helical hydrogen bonds. Bending of the helical structure around residues Aib10-Aib13 was associated with reversible flips of the peptide bonds involving G11 (Aib10-G11 or G11-L12 peptide bonds), yielding discrete structural states in which the Aib10 carbonyl or (rarely) the G11 carbonyl was oriented away from the peptide helix. These peptide bond reversals could be accommodated without greatly perturbing the adjacent helical structure, and intramolecular hydrogen bonding was generally maintained in bent states through the formation of new (non-alpha or 3[10]) hydrogen bonds with good geometries: G11 NH-V9 CO (inverse gamma turn), Aib13 NH-Aib8 CO (pi-helix) and, rarely, L12 NH- Q7 NH (pi-helix). These observations may reconcile potentially conflicting NMR structural information for alamethicin in methanol, in which evidence for conformational flexibility in the peptide sequence before P14 (G11-Aib13) contrasts with the stability of backbone amide NH groups to exchange with solvent. Similar reversible reorientation of the Thr11-Gly12 peptide bond of melittin is also observed in dynamics simulations in methanol (R. B. Sessions, N. Gibbs, and C. E. Dempsey, submitted). This phenomenon may have some role in the orientation of the peptide carbonyl in solvating the channel lumen in membrane ion channel states of these peptides.

Alamethicin↗

Thoracic spinal fracture in a rugby league footballer.

PURPOSE: The report describes the mechanisms and sequelae of the first case of thoracic vertebral fracture to be reported in a rugby league footballer. CASE SUMMARY: The injury was sustained as the result of a legal shoulder tackle. The player exhibited no sign other than dorsal midthoracic tenderness and paraspinal muscle spasm. Investigations commenced the next day because of persistent pain. CT and MRI revealed complex T6/7 fractures not evident on plain x-ray. The player was managed conservatively with analgesia and rest and has made a full recovery. DISCUSSION: Football is the most common cause of cervical spinal fractures in sport, whereas thoracic spinal fractures are very rare. Although in this case significant damage occurred to the posterior elements of the column, there were no neurological complications. RELEVANCE: The anatomical and physiological bracing of the thoracic spine accounts for the rarity of fractures in contact sport and favors conservative management.

Adolescent↗

Blue light curing units--a dermatological hazard?

The setting reactions of a large number of dental materials are activated upon exposure to visible blue light emitted from a curing unit. Although the wavelength (lambda) from such devices is principally in the visible spectrum (lambda > 400 nm) a small amount of ultraviolet radiation (UV) is also present. Little attention has been paid to the consequences of such exposure upon the skin of dental surgeons' fingers. This investigation studied the level of UVA I (lambda = 340-400 nm) emitted by three commonly used polymerisation sources and assessed the level of protection afforded by six brands of surgical glove. The integrated irradiances of the Translux, Topaz T100 and Heliomat units in the UVA I range were 15861, 3611 and 305 mW/m2 respectively. For all gloves the mean % transmission, at lambda = 400 nm, was less than 4% with the exception of one brand where, in the stretched state, the level of transmission was 7%. It is concluded that the risk of initiating adverse dermatological consequences as a result of exposure to UVA I, emitted by light polymerisation units, is minimal in normal usage. The combined effects of exposure to radiation of this type and contamination of the fingers with quantities of irritant chemicals, such as found in many dental materials, are unknown. Due to the ability of the gloves to shield the skin from both chemicals and UVA I it is recommended that gloves are routinely worn for all light curing procedures.

Dental Equipment↗

Cellular sensitivity to oxidative stress in the photosensitivity dermatitis/actinic reticuloid syndrome.

Skin fibroblasts from certain patients with the photosensitivity dermatitis/actinic reticuloid syndrome show enhanced sensitivity to ultraviolet radiation compared to normal fibroblasts. To probe further the link between oxidative damage and this disease, we have obtained a more extensive set of cell lines from patients with a severe form of the disease and examined their sensitivity towards oxidative stress by measuring cell survival following UVA radiation (330-450 nm) or hydrogen peroxide treatment (0.1-2.4 mM). The activation of the stress gene, heme oxygenase, has also been assessed by measuring the accumulation of mRNA after hydrogen peroxide treatment. Our studies have confirmed that a slight ultraviolet sensitivity is a characteristic of photosensitivity dermatitis/actinic reticuloid syndrome cell strains and we further demonstrate that these cell lines are particularly sensitive to hydrogen peroxide with up to a three- to fourfold increased sensitivity as compared to normal controls. We also show that certain ataxia telangiectasia strains that are especially sensitive to hydrogen peroxide are also slightly sensitive to ultraviolet radiation. Hydrogen peroxide induces accumulation of mRNA for the oxidant-inducible stress protein, heme oxygenase, with similar kinetics (maximum mRNA accumulation 2-4 h following treatment) and with a similar range of magnitudes in both normal (6.6-20.6 times mRNA increase over basal levels) and photosensitivity dermatitis/actinic reticuloid (2.9-12.8 times) skin cells. Because cells from photosensitivity dermatitis/actinic reticuloid patients show increased sensitivity towards oxidative stress but show no significant change in oxidant activation of the heme oxygenase gene, we propose that the defect involves a late stage of processing of oxidative damage rather than a compromised free radical scavenging system.

Adolescent↗

A comparison of J and W pouches using an isolated ileal reservoir in pigs.

A new model for studying ileal reservoirs was used to compare J and W pouches. Sixteen female piglets were operated on between 62 and 67 days of age (median = 65). An approximately 50 cm vascularized segment of terminal ileum was isolated from the faecal stream and intestinal continuity restored. The distal 40 cm of the isolated loop was opened along its antimesenteric border and the pouch constructed (J = 8, W = 8). The remaining proximal length of ileum was brought out through the abdominal wall as a mucous fistula. One piglet in the W pouch group died post-operatively and in another, spontaneous closure of the mucous fistula prevented access to the W pouch for testing leaving six W and eight J pouches for comparison. Compliance was tested at 4 weeks by measuring intrapouch pressure during continuous distension by water. The volumes instilled at pressures of 20, 40, 60 and 80 cm of water were compared using the Mann-Whitney U-Test. Volumes varied widely at all pressures within both study groups although W pouches tended to be of larger volume for any given pouch pressure (P = NS). The failure of this study to demonstrate more clearly a difference between J and W pouches may be due to the small numbers involved but the wide range of volumes seen raises doubts about the usefulness of this pouch model.

Anastomosis, Surgical↗

Common rugby league injuries. Recommendations for treatment and preventative measures.

Rugby league is the main professional team sport played in Eastern Australia. It is also very popular at a junior and amateur level. However, injuries are common because of the amount of body contact that occurs and the amount of running that is required to participate in the game. Injuries to the lower limbs account for over 50% of all injuries. The most common specific injuries are ankle lateral ligament tears, knee medial collateral and anterior cruciate ligament tears, groin musculotendinous tears, hamstring and calf muscle tears, and quadriceps muscle contusions. Head injuries are common and consist of varying degrees of concussion as well as lacerations and facial fractures. Serious head injury is rare. Some of the more common upper limb injuries are to the acromioclavicular and glenohumeral joints. Accurate diagnosis of these common injuries using appropriate history, examination and investigations is critical in organising a treatment and rehabilitation plan that will return the player to competition as soon as possible. An understanding of the mechanism of injury is also important in order to develop preventative strategies.

Athletic Injuries↗

Here comes Doctor No.

Explore the source record for details and available documents.

American Medical Association↗

Sick and tired. Uneasy patients may be surprised to find their doctors are worried too.

Under fire from all sides, the doctor-patient relationship is battered, bruised and in need of repair. American physicians are teetering on their lofty pedestals. Never have doctors been able to do so much for their patients, and rarely have patients seemed so ungrateful. Today's doctors must contend with ever changing technology, ever threatening lawsuits and a medical-industrial complex second-guessing their every decision. No wonder they often feel as sick as their patients.

Communication↗

HTLV-I--associated B-cell CLL: indirect role for retrovirus in leukemogenesis.

Serum containing antibodies to the human T-lymphotropic virus type I (HTLV-I) has been observed at a higher than expected frequency in patients with B-cell chronic lymphocytic leukemia (CLL) in an area endemic for HTLV-I. An attempt was made to determine whether the cells from patients with this leukemia were HTLV-I antigen-committed B cells that had undergone malignant transformation. Cells from two HTLV-I seropositive Jamaican patients with CLL were fused with a human B-lymphoblastoid cell line. The hybridoma cells that resulted from the fusion of CLL cells from patient I.C. produced an immunoglobulin (IgM) that reacted with the p24 gag protein from HTLV-I, HTLV-II, and HTLV-III (now referred to as HIV), but showed preferential reactivity with HTLV-I. The specific immunoglobulin gene rearrangement (IgM, kappa) in the CLL cell was demonstrated in the hybridoma cell line, indicating that the captured immunoglobulin was from the CLL cells. The IgM secreted by the fusion of CLL cells from patient L.L. reacted only with HTLV-I-infected cells and with the HTLV-I large envelope protein (gp61) on Western blots. The CLL cells from these patients appear to be a malignant transformation of an antigen-committed B cell responding to HTLV-I infection, suggesting an indirect role for this retrovirus in leukemogenesis.

Antibodies, Viral↗

Importance of cellular DNA content in pre-malignant breast disease and pre-invasive carcinoma of the female breast.

The risk of malignant change in pre-invasive breast disease such as proliferative atypia (PA) or the risk of invasive carcinoma arising from ductal carcinoma in situ (DCIS) remains uncertain in individual women because of the absence of any prognostic criteria. In order to clarify this, the cellular DNA content (ploidy) of 51 screen-detected lesions has been investigated. Cellular DNA measurements were made by static cytometry following Feulgen staining of disaggregated tissue sections and the resulting histograms classified as either diploid or aneuploid. Thirteen cases of PA and twelve of DCIS were compared with twenty-six biopsies showing DCIS with adjacent invasive carcinoma (DCIS + Ca). In the latter group, ploidy of the invasive carcinoma was compared with the associated DCIS in 16 cases. Aneuploid cells were found in approximately 30 per cent of PA and DCIS lesions but in 23 of 26 cases of DCIS + Ca. Of 16 assessable cases of co-existing DCIS and micro-invasive carcinoma both were aneuploid in 11, both diploid in 1, and in 4 cases the DCIS was aneuploid whereas the invasive carcinoma was diploid. These results suggest that aneuploidy may be of value in predicting the most biologically aggressive of these pre-invasive lesions.

Aged↗

Thyroid dysfunction in institutionalised Down's syndrome adults.

This study of 111 institutionalised Down's syndrome subjects and 74 controls found a relatively low risk of hypothyroidism in both groups compared with certain other studies of Down's subjects, which found very high rates of thyroid hypofunction. However, the Down's syndrome group had a significantly raised risk of hypothyroidism (9%), hyperthyroidism (1.8%) and the presence of thyroid microsomal antibodies (29%) compared with the controls and with laboratory reference data. It is recommended that thyroid function testing should be routine in older Down's syndrome subjects, with special attention being given to the clinical status of those with microsomal antibodies present.

Adult↗