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Biomedical subjects

W K Smith

Publications and source records attributed to W K Smith.

At least 19 recordsLinked to original sources
PubMed2006

Intratympanic gentamicin treatment in Meniere's disease: patients' experiences and outcomes.

OBJECTIVE: The aim of this study was to assess the experiences and outcomes of patients receiving intratympanic gentamicin treatment for Ménière's disease in Norfolk, UK. DESIGN: This study was based on a retrospective questionnaire survey and a review of patients' medical records. SETTING: Two district hospitals. PARTICIPANTS: All 29 patients treated between 1999 and 2001, with a minimum follow up of two years post-treatment, were included in the study. Twenty-three patients completed the questionnaires (79 per cent response rate). MAIN OUTCOME MEASURES: Glasgow benefit inventory (GBI) and vertigo symptom scale (VSS) scores, plus change in hearing thresholds. RESULTS: The mean GBI total score was +36, indicating substantial improvement in patients' overall quality of life following gentamicin treatment. The VSS scores demonstrated low levels of vertigo or unsteadiness in treated patients. Three patients suffered deterioration in their hearing thresholds following a single injection of gentamicin. However, 96 per cent of responders stated that they would be willing to have such treatment again, if necessary. CONCLUSION: Intratympanic gentamicin treatment ought to be offered to Ménière's patients suffering from disabling vertigo, with the proviso that they be made aware of the possibility of hearing deterioration.

Adult↗
PubMed2005

A national survey amongst UK otolaryngologists regarding the treatment of Ménière's disease.

Since Dr Prosper Ménière described the vertiginous syndrome that now bears his name, a large variety of medical and surgical treatments have been introduced. To determine the way in which this condition is currently managed in the United Kingdom, a postal survey amongst consultant otolaryngologists was carried out. It revealed that 52 per cent were actively involved in the treatment of patients with Ménières disease using a wide range of medical and surgical therapies that have little or no evidence base. The survey found that 94 per cent of surgeons prescribe betahistine, 63 per cent diuretics and 71 per cent advise salt restriction to their patients, while 52 per cent of surgeons continue to recommend saccus decompression and 50 per cent are still inserting a grommet. However, two thirds of respondents now advocate the use of gentamicin therapy despite it only being introduced to this country just over 10 years ago. The results of this study and their relevance to the recommended present day management of Meniere's disease are discussed.

Anti-Bacterial Agents↗
PubMed2003

CIR sand casting system for trans-tibial socket.

The authors have developed a trans-tibial socket fabrication system based on the "dilatancy" principle, a process that has been commonly used in forming wheelchair Seating. The CIR Sand Casting System replaces plaster of Paris with sand for forming both a negative sand mould and a positive sand model, which can be modified for either thermoplastic socket formation or resin lamination. Initial clinical trials suggest that fabrication times are approximately 90 minutes from patient evaluation and casting to dynamic alignment. Compatibility with all existing prosthetic components is retained. It is believed the CIR socket fabrication system may be a competitive alternative for prosthetic service providers in developing countries.

Amputation, Surgical↗
PubMed2003

The use of the KTP laser in the management of hypertrophic tracheal mucosa and granulation tissue around Provox valve protheses.

The development of hypertrophic mucosa and granulation tissue around a tracheo-oesophageal fistula voice prosthesis is a commonly encountered problem occurring in 15-20 per cent of patients. Upsizing of the voice prosthesis as well as cautery (silver nitrate and electocautery) are used to counteract this problem to a varying degree of success. The use of the CO2 laser has been mentioned by some authors but details of the method and results have not been published. We report the successful use of the KTP laser for removing such granulations whilst retaining the valve and discuss the reasons why this method should be considered.

Granulation Tissue↗
PubMed2003

Osteoradionecrosis of the hyoid presenting as a cause of intractable neck pain following radiotherapy and the role of magnetic resonance image scanning to aid diagnosis.

Osteoradionecrosis of the hyoid has been reported rarely in the worldwide literature. We present the case of a 56-year-old gentleman who presented with intractable neck pain, following surgery and radiotherapy for a T(2)N(2c)M(0) tongue base carcinoma, to highlight the need to consider osteoradionecrosis of the hyoid rather than recurrence of the carcinoma as the cause of such symptoms. The previously unreported appearance of osteoradionecrosis of the hyoid on a magnetic resonance image (MRI) scan and the use of this investigation to aid diagnosis is discussed.

Fatal Outcome↗
PubMed2002

The development of thermal resistance of the feather coat in broilers with different feathering genotypes and feeding regimes.

1. This study compared the development of thermal resistance of the feather coat in broilers, with early or late feathering genes, and with or without the naked neck gene, allowed ad libitum or restricted feeding. 2. Male and female broilers of one of the 4 genotypes were reared to 6 weeks of age and allocated to one of the two feeding regimes. The thermal resistance of the back and crop region was measured at weekly intervals. A sample of birds were killed at the same ages and total feather weight, primary and secondary flight feather weight, liver weight and abdominal fat weight were measured. 3. All three main factors, sex, feeding and genotype, had significant effects on feather weight over time. The primary and secondary flight feathers were less affected by feed restriction than the feather coat as a whole. Birds with the naked neck gene showed a greater depression in growth rate than birds with a normal neck under conditions of restricted feeding. 4. The thermal resistance of the feathers on the back was greater in females, increased by early feather growth and decreased by restricted feeding. 5. Relative to metabolic body size, birds on restricted feeding had a greater feather weight and a smaller liver. There was a marked reduction in fat deposition, to almost negligible levels by 6 weeks of age. 6. Broilers given restricted feeding, in preparation for breeding, would benefit by a warmer environment, particularly those with feathering genotypes which confer a lower thermal resistance.

Adipose Tissue↗
PubMed2001

Laryngoscopy findings in outpatient notes: the accuracy of the recording of the side of the lesion.

An analysis of 100 patient notes was performed in the South-west Thames Region to determine the accuracy of recording the side of the abnormality in outpatient clinic notes when compared to the findings at direct laryngoscopy. Direct laryngoscopy was felt to be the most accurate method of viewing the larynx. The results were analysed to determine if the specific method of outpatient laryngoscopy or grade of examiner influenced the error rates. Inconsistencies occurred in 29% of the clinic notes when a diagram of the larynx was present. Specialist Registrars made 59% of the errors. Flexible nasendoscopy accounts for more errors than indirect laryngoscopy.

Ambulatory Care↗
PubMed2001

Resection of a plantar calcaneal spur using the holmium:yttrium-aluminum-garnet (Ho:YAG) laser.

Many procedures have been described for the resection of plantar calcaneal spurs as treatment of heel spur syndrome and chronic plantar fasciitis. Most of these techniques involve a medial incision of between 2 and 6 cm for adequate exposure of the calcaneal spur. This article describes a new technique for resecting a calcaneal spur with a smaller medial incision using the holmium:yttrium-aluminum-garnet (Ho:YAG) laser. This laser permits adequate resection of a plantar calcaneal spur as well as coagulation of the bone and surrounding tissues. This minimally invasive procedure has been used with good results over the past year by the senior author (W.K.S.) for the resection of calcaneal spurs.

Calcaneus↗
PubMed2001

Estimating near-infrared leaf reflectance from leaf structural characteristics.

The relationship between near-infrared reflectance at 800 nm (NIRR) from leaves and characteristics of leaf structure known to affect photosynthesis was investigated in 48 species of alpine angiosperms. This wavelength was selected to discriminate the effects of leaf structure vs. chemical or water content on leaf reflectance. A quantitative model was first constructed correlating NIRR with leaf structural characteristics for six species, and then validated using all 48 species. Among the structural characteristics tested in the reflectance model were leaf trichome density, the presence or absence of both leaf bicoloration and a thick leaf cuticle (>1 μm), leaf thickness, the ratio of palisade mesophyll to spongy mesophyll thickness (PM/SM), the proportion of the mesophyll occupied by intercellular air spaces (%IAS), and the ratio of mesophyll cell surface area exposed to IAS (A(mes)) per unit leaf surface area (A), or A(mes)/A. Multiple regression analysis showed that measured NIRR was highly correlated with A(mes)/A, leaf bicoloration, and the presence of a thick leaf cuticle (r = 0.93). In contrast, correlations between NIRR and leaf trichome density, leaf thickness, the PM/SM ratio, or %IAS were relatively weak (r < 0.25). A model incorporating A(mes)/A, leaf bicoloration, and cuticle thickness predicted NIRR accurately for 48 species (r = 0.43; P < 0.01) and may be useful for linking remotely sensed data to plant structure and function.

Journal Article↗
PubMed2001

Floral movements in response to thunderstorms improve reproductive effort in the alpine species Gentiana algida (Gentianaceae).

Studies of floral movements in response to environmental change are rare in the literature, and information about possible adaptive benefits appears nonexistent. The closure of the upright, tubular flowers of alpine gentian (Gentiana algida) were observed during the frequent afternoon thunderstorms characteristic of the central and southern Rocky Mountains (USA). Flowers closed within minutes of an approaching thunderstorm and reopened after direct sunlight returned. Corolla opening widths decreased ∼10%/min prior to rainfall, in close correspondence to declines in air and corolla temperatures. Identical floral behavior was also induced experimentally in the field and laboratory by artificial changes in corolla temperature. Corolla closure did not occur during experiments that simulated natural changes in solar irradiance, wind, or absolute humidity during a thunderstorm. Furthermore, individual G. algida plants forced experimentally to remain open during rain had substantial losses of pollen after single rain events (up to 34%) and if forced to remain open for the entire flowering period (59%). Subsequent seasonal reductions in female fitness (up to 73%) also occurred, including seed size and mass, number of ovules produced, number of viable seeds produced per ovule, and seed germination. Thus, corolla closing and opening in G. algida associated with frequent summer thunderstorms may be a behavioral adaptation that improves both paternal and maternal reproductive effort.

Journal Article↗
PubMed2000

Leptin and maternal growth during adolescent pregnancy.

BACKGROUND: Maternal growth on the basis of knee height occurs in nearly 50% of pregnant teenagers and is associated with greater gestational weight gain and accrual of subcutaneous fat in the mother but lower fetal growth compared with nongrowing teenagers and mature pregnant women. OBJECTIVE: The objective of this study was to determine whether leptin is a biomarker for continued maternal growth. DESIGN: Leptin concentrations were measured in 162 growing and nongrowing teenage gravidas (aged </=18 y) and in mature gravidas (aged 19-29 y) from the Camden Study at 2 time points during pregnancy and 1 time point postpartum. RESULTS: Growing teenagers had leptin concentrations that increased with gestation and were higher at 28 wk gestation and postpartum than in nongrowing teenagers and mature gravidas. The differences were related to a leptin surge between entry into the study (16.9 wk) and week 28, primarily in still-growing gravidas. Leptin-surge quartiles were associated with higher knee-height velocity and weight gain, increased skinfold thicknesses in late pregnancy (28 wk) and early postpartum (4-6 wk), and changes in postpartum weight and body mass index. For the highest quartile, low birth weight increased >5-fold, fetal growth restriction increased >6-fold, and infant birth weight decreased by approximately 200 g. Gravidas who developed pregnancy-induced hypertension showed a different pattern-higher leptin concentrations at entry and week 28, no difference in the leptin surge, and no postpartum difference in leptin concentration. CONCLUSION: A leptin surge by week 28 appears to mark reduced mobilization of maternal fat stores that is associated with maternal growth on the basis of knee height during adolescent pregnancy.

Adolescent↗
PubMed2000

Assessment of hearing in persons with learning disabilities: the Phoenix NHS Trust, January 1997 to September 1998.

People with learning disabilities are at increased risk of impaired hearing. The aims of this study were to assess the prevalence of hearing impairment and ear disease in people attending the specialist Otolaryngology/Hearing Therapy clinic at the Phoenix NHS Trust, Bristol. The present and future process of such a service was explored. Data were obtained from the referral form and notes made by the consultant otolaryngologist. In 20 months, there were 226 consultations, 188 of which were new referrals. The majority of patients had verbal communication to some extent. Suspected infection/inflammation and unobtainable/abnormal tympanograms, each accounted for 43 per cent of reasons for referral. Twenty per cent of patients were normal otologically. Eighteen per cent were provided with hearing aids and nine per cent required surgery. Ten patients underwent brainstem evoked response testing, half of whom had aidable hearing. Our results are comparable to published data of similar units. It is recommended that combined otolaryngology/specialist hearing therapy services are continued and further developed.

Adult↗
PubMed1999

Lymphoedema and hand surgery.

We report the case of a woman with a previous history of breast carcinoma, treated with a left radical mastectomy and axillary clearance, who developed lymphoedema in the left arm following a carpal tunnel decompression complicated by a superficial wound infection.

Aged↗
PubMed1998

Recombinant bovine somatotropin (rbST) administration to creep-fed beef calves increases muscle mass but does not affect satellite cell number or concentration of myosin light chain-1f mRNA.

Our objective in this study was to determine the effect of recombinant bovine somatotropin (rbST) on indices of muscle development in creep-fed beef calves. Crossbred steer calves were assigned to one of two treatment groups: control (sham-injected; n = 12) or rbST-treated (.09 mg x kg(-1) x d(-1); n = 12). Calves were injected every 14 d starting at d 28 of age and were weaned at 205 d of age. Supplemental creep feed was supplied free access to all calves to compensate for an expected increased protein and energy requirement in calves given rbST. Biopsy (d 100) and slaughter (d 206) samples of semitendinosus muscle were evaluated for satellite cell, myofiber nuclei numbers, and myosin light chain (MLC-1f) mRNA quantification. Myofiber nuclei and satellite cell numbers per 100 myofibers and MLC-1f mRNA:rRNA ratios at 100 and 206 d of age were not different (P > .10) between control and rbST-treated calves. Total gain, ADG, quality grade, femur length, percentage kidney, pelvic, and heart fat, dressing percentage, plasma IGF-I, and plasma urea nitrogen concentrations did not differ (P > .10) between control and rbST-treated calves. However, rbST-treated calves had larger longissimus muscle areas (P < .03), less marbling (P < .001), higher carcass conformation scores (P < .04), greater mass of separated muscle (P < .03), more ground meat (P < .01), and heavier carcass weights (P < .05) than control calves. Thus, rbST treatment increased muscle characteristics while nuclei number and MLC-1f mRNA concentrations remained the same, implying that the additional muscle growth was in a normal fashion.

Animal Feed↗
PubMed1997

Use of multivitamin/mineral prenatal supplements: influence on the outcome of pregnancy.

The objective of this study was to examine the association of prenatal multivitamin/mineral supplement use during the first and second trimesters of pregnancy by low income, urban women in the Camden Study (1985-1995, n = 1,430) and preterm delivery (< 37 completed weeks) and infant low birth weight (< 2,500 g). Prenatal supplement use was corroborated by assay of circulating micronutrients at entry to care (no differences) and week 28 gestation (increased concentrations of folate and ferritin for supplement users). Compared with women who entered care during the first or second trimester but did not use prenatal supplements, supplement use starting in the first or second trimester was associated with approximately a twofold reduction in risk of preterm delivery. After controlling for potential confounding variables, risk of very preterm delivery (< 33 weeks' gestation) was reduced more than fourfold for first trimester users and approximately twofold when use dated from the second trimester. Infant low birth weight and very low birth weight (< 1,500 g) risks were also reduced. Risk of low birth weight was reduced approximately twofold with supplement use during the first and second trimester. Diminution in risk was greater for very low birth weight infants, amounting to a sevenfold reduction in risk of very low birth weight with first trimester supplementation and a greater than sixfold reduction when supplement use started in the second trimester. Thus, in low income, urban women, use of prenatal multivitamin/mineral supplements may have the potential to diminish infant morbidity and mortality.

Adolescent↗
PubMed1995

Gestational weight gain, pregnancy outcome, and postpartum weight retention.

OBJECTIVE: To determine whether the risk of maternal overweight associated with an excessive rate of gestational gain needs to be balanced against the risks of impaired fetal growth associated with a low rate of gain. METHODS: Rate of gestational weight gain was measured prospectively in a sample of 274 young, low-income, and primarily minority women (12-29 years old) with pregravid body mass indices (BMI) in the normal range (19.8-26.0). We defined an excessive rate of gain between 20-36 weeks' gestation as one greater than 0.68 kg/week, and a low rate of gain as one less than 0.34 kg/week. Women were followed-up at 4-6 weeks and 6 months postpartum. RESULTS: Rate of measured gestational gain between 20-36 weeks' gestation was associated with total weight gain based on pregravid weight, with infant birth weight and gestation duration, and with maternal overweight (BMI greater than 26) and weight retention postpartum. Infant birth weight and gestation duration were significantly reduced for women with low rates of gain, and there was no significant difference between women with excessive and moderate gains. Despite little difference in pregravid BMI, women with excessive rates of gain retained more weight overall, attained a greater postpartum BMI, and had higher levels of subcutaneous fat and overweight. Maternal anthropometric status showed little change between 4-6 weeks and 6 months postpartum. CONCLUSION: Weight gained at an excessive rate by women with a pregravid BMI in the normal range does not greatly enhance fetal growth and gestation duration, contributing instead to postpartum maternal overweight.

Adolescent↗
PubMed1994

Structural scaling of light interception efficiency in Picea engelmannii and Abies lasiocarpa.

Sunlight interception efficiency was compared at the leaf, shoot, branch and crown levels for Picea engelmannii (Parry) and Abies lasiocarpa ((Hook.) Nutt.), dominant tree species of the central Rocky Mountains, USA. The ratio of silhouette to total leaf area (STAR) was used to quantify the efficiency of direct-beam sunlight interception at each structural scale. Total mean reductions in STAR from the leaf to the crown level were 0.39 to 0.06 in P. engelmannii and 0.46 to 0.02 in A. lasiocarpa. These reductions in STAR occurred for both species as structural scale increased due to a more upright leaf inclination, increased leaf twisting and curvature, or greater mutual shading among plant structures. A steeper leaf inclination between the leaf and shoot level accounted for 26 +/- 19% (95% C.I.) of the total leaf-to-crown STAR reduction; mutual shading among leaves on shoots caused a 14 +/- 7% reduction, whereas leaf curvature and twisting accounted for 22 +/- 3% for a total reduction of 62 +/- 8%. The STAR varied slightly from the shoot to the branch level (+/- 7%) except for a 26% reduction in shade shoots of A. lasiocarpa as a result of increased mutual shading among leaves at lateral nodes. Another substantial reduction in STAR occurred from the branch to the crown level (35 +/- 3% of total) as a result of shading of one branch layer by another within the crown. Thus, light interception efficiency decreased as structural scale increased in both species, especially from the leaf to the shoot level and from the branch to the crown level.

Journal Article↗