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Biomedical subjects

L Turner

Publications and source records attributed to L Turner.

At least 19 recordsLinked to original sources

Long-term outcomes of elective human sperm cryostorage.

BACKGROUND: Sperm cryopreservation allows men with threatened fertility to preserve their progenitive potential, but there is little data on long-term outcomes of elective sperm cryostorage programmes. METHODS AND RESULTS: Over 22 years, 930 men sought semen cryostorage in a single academic hospital, of which 833 (90%) had spermatozoa cryostored. Among 692 (74%) men surviving their illness, sperm samples were discarded for 193 (21% of all applicants, 28% of survivors) and cryostored spermatozoa were used for 64 men (7% of all applicants, 9% of survivors) in 85 treatment cycles commencing at a median of 36 months post-storage (range 12-180 months) with nearly 90% of usage started within 10 years of storage and none after 15 years. Pregnancy was most efficiently produced by intracytoplasmic sperm injection (median three cycles) compared with conventional IVF (median eight cycles) or artificial insemination (median more than six cycles; P < 0.05). A total of 141 (15%) of men had died and of these, 120 (85% of those dying) had their spermatozoa discarded; requests to prolong cryostorage were received from relatives of 21 men (2% of all applicants, 15% of deceased) of which three cases had spermatozoa transferred for use with no pregnancies reported. Sperm concentration was lower for all cryostorage groups compared with healthy sperm donor controls (P < 0.05). Following orchidectomy, men with testicular cancer had sperm density approximately half that of all other groups of men seeking cryostorage (P < 0.05), the lowering attributable to removal of one testis rather than in defects in spermatogenesis. CONCLUSION: Elective sperm cryopreservation is an effective, if sparsely used, form of fertility insurance for men whose fertility is threatened by medical treatment and is an essential part of any comprehensive cancer care programme.

Adult↗

The effects of lactation education and a prosthetic obturator appliance on feeding efficiency in infants with cleft lip and palate.

OBJECTIVE: This prospective study examined the effect of lactation instruction and palatal obturation in decreasing time to feed, increasing intake, and on growth in eight breast milk bottle-fed newborn infants with cleft lip, cleft palate, or both. DESIGN: An A, B1, C1, B2, and C2 reversal design was used with eight mothers. In A, baseline data on minutes fed by breast were recorded. In B1, baseline on minutes fed with a Haberman bottle was recorded. In C1, minutes fed following lactation education and palatal obturation were documented. Lactation education was information given to mothers to recognize infant feeding cues and to have infant-led feedings. The palatal obturator was a passive molding appliance. In B2, the obturator was removed and minutes fed noted. In C2, the obturator was returned and lactation support provided. Mothers kept feeding logs, satisfaction was assessed, and infant breast milk intake and flow rate were recorded during each study phase. Routine nutrition evaluation of weight, height, weight for height, and feed volume was completed by a registered dietitian during and following completion of the study. RESULTS: Feeding times decreased with all infants, volume consumed increased with seven of eight infants, and flow rate increased with all infants. Mean feeding times during B1 and B2 phases (Haberman bottle only) were 34.4 and 32.3 minutes, respectively. Mean feeding times during C1 and C2 phases (obturation and lactation education) were 15.1 and 15.6 minutes. Volume of milk consumed during B1 and B2 feedings averaged 36.5 and 37 mL, compared with 67 mL and 76 mL during C1 and C2 phases. Growth as measured by height, weight gain, and weight for height during the study and the first 2 years of life compared favorably with that of children born without clefts. CONCLUSIONS: The combined use of a palatal obturator and lactation education reduced feeding time and increased volume intake and was associated with good growth. Mothers who had desired to breast-feed elected to use the obturator to support high-volume intake, decrease infant fatigue, and provide breast milk for nutrition.

Analysis of Variance↗

Counseling female athletes: application of the stages of change model to avoid disordered eating, amenorrhea, and osteoporosis.

Research indicates that female athletes from all sports are at risk for developing disordered eating. amenorrhea, and resulting complications. These disorders, termed the female athlete triad by the American College of Sports Medicine, may lead to significant morbidity and mortality as well as medical and psychological problems. When female athletes feel pressured to fit a specific physical image, they may develop distorted body images and show disordered eating patterns. Menstrual dysfunction and premature osteoporosis may result from inadequate nutrition combined with excessive athletic training. Health professionals play important roles in prevention and treatment of these problematic behaviors. This paper examined the stages of the change behavior model and its use in addictive behaviors and provides theoretical applications of this model to reducing harmful behaviors in female athletes.

Adult↗

Gene expression abnormalities in human glial tumors identified by gene array.

Novel genes specific for human oligodendroglioma and glioblastoma multiforme (GBM) were detected using the gene array analysis [18,376 genes Gene Discovery Array (GDA) from Incyte Genomics, Inc.]. Eleven genes were chosen based on the highest ratios of differential expression identified by GDA between histologically normal adjacent tissue and brain tumor tissue. The differential expression of those 11 genes was verified by semiquantitative RT-PCR and Northern analysis on 22 samples of glial and other tumors of the brain, as well as of normal embryonic and adult brain tissue. Gene no. 5 (an EST) was more expressed by GDA analysis in histologically normal adjacent brain tissue than in the corresponding oligodendroglioma. By RT-PCR, this gene was expressed in a number of brain tumors but not in normal adult and embryonic brain. By GDA analysis, gene no. 7 (oligophrenin-1) gave the highest ratio compared to other genes in brain tissue adjacent to the GBM vs. GBM. By RT-PCR, oligophrenin-1 was expressed in tumors and tumor-adjacent tissue, whereas meningioma and corpus callosum were negative. Gene no. 11 (an EST) was expressed only in brain tumors but not in normal brain by Northern analysis (message size 1.5 kb) and RT-PCR. GDA analysis successfully identified genes preferentially expressed in brain tumors, which was confirmed by Northern analysis and semiquantitative RT-PCR. The validity of gene arrays for tumor-specific gene discovery is discussed. Study of differential gene expression in glial tumors should help identify the mechanism/s of transformation of normal glial cells to malignant.

Brain Neoplasms↗

Changes in self-efficacy and readiness for smoking cessation among women with high school or less education.

The most common theory of smoking cessation postulates that readiness to quit begins with changes in attitudes that move the smoker toward behavioral change and eventual cessation. However, trends in smoking indicate that many who currently smoke are not ready to quit. Hence, strategies that both enhance readiness and focus on quitting are likely to be most effective. We hypothesize that an intervention addressed to motivating behavior change will enhance readiness to change, which will in turn increase the smokers self-efficacy regarding further change. A smoking cessation intervention that combined a self-help booklet and televised segments was developed to address these issues in a population of women smokers with high school or less education. Readiness to quit was measured prior to the intervention, immediately following the intervention, and again at six and 12 months after intervention. The results indicate that the intervention had its effects on readiness to quit, which in turn affected self-efficacy, which further enhanced readiness to quit. These findings indicate that interventions aimed at this group of smokers may need to provide achievable objectives that focus on preparing the smoker to quit as well as promote cessation.

Adult↗

Bone densitometry in assessment of bone mineral density.

Osteoporosis is a serious disease characterized by low bone mineral density. Osteoporosis affects 24 million people annually and may be responsible for devastating hip, wrist and spinal fractures. Bone mineral density is considered the best predictor for osteoporotic fracture. Progress has been made toward noninvasive assessment of bone mineral density to provide early diagnosis of osteoporosis. A variety of methods are used to assess bone mineral density. These methods are presented and dual energy X-ray absorptiometry is discussed in detail.

Absorptiometry, Photon↗

Effects of sleep loss on waking actigraphy.

STUDY OBJECTIVES: To assess the effect of sleep loss and the effect of a sedating drug on waking actigraphy DESIGN: N/A SETTING: N/A PARTICIPANTS: Seventeen healthy volunteers, aged 19-35 yrs INTERVENTIONS: Four night-day treatments presented in a Latin Square Design: placebo-8 hr time-in-bed (TIB), placebo-4 hr TIB, placebo-0 hr TIB, and diphenhydramine 50 mg-8 hr TIB. MEASUREMENTS AND RESULTS: After the appropriate TIB, medication was administered at 09:00 hr, the Multiple Sleep Latency Test at 09:30, 11:30, 13:30, 15:30, and 17:30 hr, and a 45 min performance battery at 10:30, 14:30, and 16:30 hr. Each day the volunteers wore actigraphs from 0700-1800 hrs. Decreasing TIB was associated with decreased daily mean sleep latency on the MSLT with 4 and 0 hrs differing from 8 hrs and each other. Daytime activity also was reduced by the reduced prior TIB. Increased inactivity relative to the 8 hr TIB developed between the 4 hr and 0 hr TIBs, with 4 hrs differing from 0 hrs, but not 8 hrs. Diphenhydramine 50 mg reduced mean daily sleep latency and increased percent inactive time relative to placebo. On the MSLT diphenhydramine was intermediate to 4 hr and 0 hr TIB and on actigraphy it was similar to 0 hr TIB. CONCLUSIONS: The difference in the effect of diphenhydramine on these actigraphy and MSLT may reflect the different sensitivities of the measures.

Adult↗

Conditions in grey seal pups (Halichoerus grypus) presented for rehabilitation.

A survey was carried out on the condition of 188 live grey seal (Halichoerus grypus) pups presented for rehabilitation from the coasts of south-west England between 1992 and 1998. The survey was carried out to assess the incidence of malnutrition, hyperthermia, respiratory and gastrointestinal conditions, and also the incidence of traumatic, skin, oral and ocular lesions. Malnutrition was a common finding in pups approaching weaning (mid-moult pups) and those at the point of weaning or postweaning (moulted pups) (62 per cent and 82 per cent, respectively). Separation from the dam, believed to be the main cause of malnutrition in grey seals, was encountered frequently in unweaned pups (91 per cent). Thirty-nine per cent of pups presented with a respiratory condition, 38 per cent with hyperthermia and 9 per cent with diarrhoea. Seven per cent and 14 per cent of pups had confirmed respiratory and gastrointestinal parasitic infestations respectively, although these were probably underestimates. Clinically significant traumatic lesions were seen in 41 per cent, oral ulceration in 26 per cent, ocular conditions in 13 per cent, nail bed infections in 13 per cent and oiling in 10 per cent of pups. Umbilical infections and other skin and oral conditions were also encountered. The incidence of these conditions is compared with data from dead grey seals, and clinical conditions in other pinniped species presented for rehabilitation.

Animals↗

Manifestation of random phase in a finite ensemble of a turbulent fluid

A field can be specified by a set of spectral coefficients, c(j)(t), relative to an expansion basis. In fluid turbulence, one often assumes the condition that if one were to extract data from an ensemble of realizations, one would find that the average, , would vanish unless i = i('), as in the case of a homogeneous ensemble in which the i's represent wave vectors. We analytically treat an extension to the case in which one has a larger number of coefficients than realizations, introducing intrinsic linear dependences that vitiate the stated condition.

Journal Article↗

Signature currents: a patch-clamp method for determining the selectivity of ion-channel blockers in isolated cardiac myocytes.

BACKGROUND: We describe a simple method using membrane potential ramps for rapidly determining the ion-channel selectivity of drugs that affect action-potential duration in isolated cardiac myocytes. The method allows the simultaneous assay of compounds on a number of ionic currents in a single cardiac cell. METHODS: Trains of membrane potential ramps were applied from -90 to +70 mV at 0.33 Hz to obtain a consistent "signature current," in which the major individual currents involved in the cardiac action potential could be easily identified. Confirmatory experiments were performed using known inhibitors of these currents. RESULTS: The identities of the currents in the signature were established by varying the concentrations of extracellular cations and by adding known ion channel blockers to superfusion solutions. Inhibition of each current had a characteristic and reproducible effect on the overall signature current. CONCLUSIONS: The consistent current signature in the presence and absence of blockers suggests that this method could be used for tertiary electrophysiological evaluation of compounds, eg, in a drug discovery program focusing on antiarrhythmic agents. The ability to assay for secondary effects of novel compounds against multiple currents in the target cell type is convenient and avoids the artefacts associated with using artificial expression systems.

Action Potentials↗

The antenatal ward care delivery map: a team model approach.

We begin by defining the concept of a 'CareMap', before briefly examining the context in which CareMaps emerged, as well as both their potential applications and the benefits arising from their implementation in health care services. We identify and discuss the history of, and critical aspects involved in, the development of the Antenatal Ward Care Delivery Map for the Mater Mothers' Hospital, Brisbane. We will address the multiple applications of, and specific benefits arising from, the formulation and implementation of the Antenatal Ward Care Delivery Map. Additionally, the relationship between the Care Delivery Map and other projects aimed at enhancing and maintaining high quality service delivery for patients across the continuum of care, will be explored. We examine the benefits of utilising the Care Delivery Map in professional education for clinical staff, as well as for health care consumers and their families. In conclusion, future projects enabled through the development of the Care Delivery Map are identified, as well as areas requiring further research.

Continuity of Patient Care↗

The rug3 locus of pea encodes plastidial phosphoglucomutase.

Two cDNA clones were isolated from pea (Pisum sativum L.) and their deduced amino acid sequences shown to have significant homology to phosphoglucomutases from eukaryotic and prokaryotic sources. The longer cDNA contained a putative transit-peptide-encoding sequence, supporting the hypothesis that the isolated clones represent the cytosolic and plastidial isoforms of phosphoglucomutase in pea. Plastid protein import assays confirmed that the putative plastidial isoform was targeted to the plastid stroma where it was proteolytically processed. Expression, co-segregation, linkage, and molecular analyses have confirmed that the rug3 locus of pea encodes plastidial phosphoglucomutase. Mutations at this locus result in a near-starchless phenotype of the plant.

Amino Acid Sequence↗

Real-time imaging of fluorescent flagellar filaments.

Bacteria swim by rotating flagellar filaments that are several micrometers long, but only about 20 nm in diameter. The filaments can exist in different polymorphic forms, having distinct values of curvature and twist. Rotation rates are on the order of 100 Hz. In the past, the motion of individual filaments has been visualized by dark-field or differential-interference-contrast microscopy, methods hampered by intense scattering from the cell body or shallow depth of field, respectively. We have found a simple procedure for fluorescently labeling cells and filaments that allows recording their motion in real time with an inexpensive video camera and an ordinary fluorescence microscope with mercury-arc or strobed laser illumination. We report our initial findings with cells of Escherichia coli. Tumbles (events that enable swimming cells to alter course) are remarkably varied. Not every filament on a cell needs to change its direction of rotation: different filaments can change directions at different times, and a tumble can result from the change in direction of only one. Polymorphic transformations tend to occur in the sequence normal, semicoiled, curly 1, with changes in the direction of movement of the cell body correlated with transformations to the semicoiled form.

Escherichia coli↗

Waldeyer's ring lymphoma presenting as massive oropharyngeal hemorrhage.

A case report of a patient presenting with massive oropharyngeal hemorrhage originating from lymphoma of the tonsil and it's management is discussed. Locally advanced or recurrent squamous cell carcinoma may manifest with massive oropharyngeal hemorrhage, however, it is unusual for Waldeyer's ring lymphoma to present in this fashion. Management of oropharyngeal malignancies presenting in this manner includes airway control, control of hemorrhage, and biopsy of the tumor. Hemorrhage control is provided by surgical exploration or intraarterial embolization. Extranodal lymphoma of the head and neck is not uncommon and is thoroughly discussed in the medical literature. Hemorrhage into the upper aerodigestive tract is occasionally observed in the patient with head and neck cancer. It usually occurs, however, in patients with squamous cell carcinoma that have been previously treated or in patients with locally advanced cancers. A comprehensive review of the literature has revealed no other reports of head and neck lymphoma presenting with massive oropharyngeal hemorrhage.

Aged↗