Perceptions of friendship, peers and influence on adolescent smoking according to tobacco control context: a systematic review and meta-ethnography of qualitative research

BACKGROUND

A relationship between smoking and interpersonal influences has been well established within the literature. There have been cultural shifts in denormalisation and a reduction in tobacco smoking in many countries. Hence there is a need to understand social influences on adolescents' smoking across smoking normalisation contexts.

METHODS

The search was conducted in July 2019 and updated in March 2022 within 11 databases and secondary sources. Search terms included schools, adolescents, smoking, peers, social norms and qualitative research. Screening was conducted by two researchers independently and in duplicate. Study quality was assessed using the eight-item Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-centre) tool for the appraisal of qualitative studies. Results were synthesised using a meta-narrative lens for meta-ethnography and compared across smoking normalisation contexts.

RESULTS

Forty one studies were included and five themes were developed, mapping onto the socio ecological model. The social processes by which adolescents take up smoking differed according to a mixture of school type, peer group structure and the smoking culture within the school, as well as the wider cultural context. Data available from smoking denormalised contexts, described changes in social interactions around smoking to cope with its stigmatisation. This was manifested through i) direct peer influence, whereby subtle techniques were employed, ii) group belonging whereby smoking was less likely to be seen as a key determinant of group membership and smoking was less commonly reported to be used as a social tool, and iii) popularity and identity construction, whereby smoking was perceived more negatively in a denormalised context, compared with a normalised context.

CONCLUSIONS

This meta-ethnography is the first study to demonstrate, drawing on international data, that peer processes in adolescent smoking may undergo changes as smoking norms within society change. Future research should focus on understanding differences across socioeconomic contexts, to inform the adaptation of interventions.

Silicon-Vacancy Spin Qubit in Diamond: A Quantum Memory Exceeding 10 ms with Single-Shot State Readout

The negatively charged silicon-vacancy (SiV^{-}) color center in diamond has recently emerged as a promising system for quantum photonics. Its symmetry-protected optical transitions enable the creation of indistinguishable emitter arrays and deterministic coupling to nanophotonic devices. Despite this, the longest coherence time associated with its electronic spin achieved to date (∼250  ns) has been limited by coupling to acoustic phonons. We demonstrate coherent control and suppression of phonon-induced dephasing of the SiV^{-} electronic spin coherence by 5 orders of magnitude by operating at temperatures below 500 mK. By aligning the magnetic field along the SiV^{-} symmetry axis, we demonstrate spin-conserving optical transitions and single-shot readout of the SiV^{-} spin with 89% fidelity. Coherent control of the SiV^{-} spin with microwave fields is used to demonstrate a spin coherence time T_{2} of 13 ms and a spin relaxation time T_{1} exceeding 1 s at 100 mK. These results establish the SiV^{-} as a promising solid-state candidate for the realization of quantum networks.

Quantum Nonlinear Optics with a Germanium-Vacancy Color Center in a Nanoscale Diamond Waveguide

We demonstrate a quantum nanophotonics platform based on germanium-vacancy (GeV) color centers in fiber-coupled diamond nanophotonic waveguides. We show that GeV optical transitions have a high quantum efficiency and are nearly lifetime broadened in such nanophotonic structures. These properties yield an efficient interface between waveguide photons and a single GeV center without the use of a cavity or slow-light waveguide. As a result, a single GeV center reduces waveguide transmission by 18±1% on resonance in a single pass. We use a nanophotonic interferometer to perform homodyne detection of GeV resonance fluorescence. By probing the photon statistics of the output field, we demonstrate that the GeV-waveguide system is nonlinear at the single-photon level.

Scalable focused ion beam creation of nearly lifetime-limited single quantum emitters in diamond nanostructures

The controlled creation of defect centre—nanocavity systems is one of the outstanding challenges for efficiently interfacing spin quantum memories with photons for photon-based entanglement operations in a quantum network. Here we demonstrate direct, maskless creation of atom-like single silicon vacancy (SiV) centres in diamond nanostructures via focused ion beam implantation with ∼32 nm lateral precision and <50 nm positioning accuracy relative to a nanocavity. We determine the Si+ ion to SiV centre conversion yield to be ∼2.5% and observe a 10-fold conversion yield increase by additional electron irradiation. Low-temperature spectroscopy reveals inhomogeneously broadened ensemble emission linewidths of ∼51 GHz and close to lifetime-limited single-emitter transition linewidths down to 126±13 MHz corresponding to ∼1.4 times the natural linewidth. This method for the targeted generation of nearly transform-limited quantum emitters should facilitate the development of scalable solid-state quantum information processors.

Interfacing spin quantum memories with photons requires the controlled creation of defect centre—nanocavity systems. Here the authors demonstrate direct, maskless creation of single silicon vacancy centres in diamond nanostructures, and report linewidths comparable to naturally occurring centres

Tailoring Oxygen Sensitivity with Halide Substitution in Difluoroboron Dibenzoylmethane Polylactide Materials

The dual-emissive properties of solid-state difluoroboron β-diketonate-poly(lactic acid) (BF2bdkPLA) materials have been utilized for biological oxygen sensing. In this work, BF2dbm(X)PLA materials were synthesized, where X = H, F, Cl, Br, and I. The effects of changing the halide substituent and PLA polymer chain length on the optical properties in dilute CH2Cl2 solutions and solid-state polymer films were studied. These luminescent materials show fluorescence, phosphorescence, and lifetime tunability on the basis of molecular weight, as well as lifetime modulation via the halide substituent. Short BF2dbm(Br)PLA (6.0 kDa) and both short and long BF2dbm(I)PLA polymers (6.0 or 20.3 kDa) have fluorescence and intense phosphorescence ideal for ratiometric oxygen sensing. The lighter halide-dye polymers with hydrogen, fluorine, and chlorine substitution have longer phosphorescence lifetimes and can be utilized as ultrasensitive oxygen sensors. Photostability was also analyzed for the polymer films.

Aromatic difluoroboron β-diketonate complexes: effects of π-conjugation and media on optical properties

Aromatic difluoroboron β-diketonate complexes (BF2bdks) are classic fluorescent molecules that have been explored as photochemical reagents, two-photon dyes, and oxygen sensors. To gain a better understanding of their emissive properties in both solution and polymer matrices, BF2bdks with varying aromatic groups were synthesized and their photophysical properties were investigated in both methylene chloride and poly(lactic acid) (PLA). Absorption spectra showed systematic variations that are well correlated with structural features, including the size of the aryl substituent and the presence of a para electron-donating methoxy substituent. Computational modeling of the absorption spectra with the TD-B3LYP/6-311+G(d)//B3LYP/6-31G(d) formulation of density functional theory and a polarizable continuum model of dichloromethane solvent shows that all systems show intense π-π* one-electron excitations, usually from one of the highest occupied molecular orbitals (HOMO - k, k = 0, 1, 2) to the lowest unoccupied molecular orbital (LUMO). Emission properties are sensitive to the dye structure and medium. Based on spectroscopic and lifetime studies, BF2bdks exhibit comparable fluorescence properties in both solutions and polymers when the diketonate group is functionalized with smaller aromatic ring systems such as benzene. For BF2bdks with larger arene ring systems, such as anthracene, emission from a strong intramolecular charge-transfer (ICT) state was also noted in both solution and in PLA. There are differences in relative intensities of peaks arising from π-π* and ICT excitations depending upon dye loading in PLA. Substituent effects were also observed. Electron-donating methoxyl groups on the aromatic rings lead to enhanced fluorescence quantum yields. For certain dyes, phosphorescence is detected at low temperature or under a nitrogen atmosphere in PLA matrices.

An easy method to monitor lactide polymerization with a boron fluorescent probe

Fluorescence spectroscopy has been widely used to monitor different polymer processes such as polymerization kinetics, chain entanglements, and thermal transitions. The solvent-free controlled ring-opening polymerization (ROP) of lactide is significant both commercially and for research; thus, monitoring this process with a simple fluorescence method can be very useful. Here, a fluorescent dye, difluoroboron 4-methoxydibenzoylmethane (BF(2)dbmOMe) is employed to probe lactide bulk ROP by measuring the emission from solidified reaction aliquots at room temperature. It was found that, through the course of polymerization, the fluorescence of BF(2)dbmOMe in the solid-state aliquots exhibited a systematic shift from yellow to green and then to blue, accompanied by a gradual reduction in the decay lifetime. The fluorescence color change is sensitive to the monomer percent conversion, not the polymer molecular weight. On the basis of these observations and experimental data, we propose that the long-wavelength emission with perceivably longer lifetimes arises from BF(2)dbmOMe dye aggregates (ground and/or excited states), while the dissolved individual dye molecules are responsible for the blue fluorescence with a shorter lifetime. This demonstration of the utility of BF(2)dbmOMe as a fluorescent probe for lactide polymerization could have important practical implications.

A survey of family doctors on the likeability of migraine and other common diseases and their prevalence of migraine

A survey of 148 family doctors attending a continuing medical education migraine update lecture was performed to assess whether family doctors like to treat migraine and other common disorders and the prevalence of migraine. Doctors were asked to respond to the following statement using a five-point Likert scale (from 1, strongly disagree to 5, strongly agree): 'I like to treat patients with this disease or symptom'. The response rate was 53% with a mean age of 51.5 years. Doctors reported liking to treat general medical conditions more (mean = 4.40) than migraine (mean = 3.38) and other neurological diseases (mean = 3.20). Doctors reported a personal history of migraine in the prior 1 year of 22.8% and 45.6% lifetime, with 17% becoming aware for the first time that they personally had migraine after attending the lecture. Respondents with a personal history of migraine liked to treat migraine more than those without a history.

Risk factors for incident Alzheimer's disease in African Americans and Yoruba

INTRODUCTION

The incidence rate of Alzheimer's disease (AD) was found to be 2 times lower in Yoruba than in African Americans. This study was aimed at identifying the factors associated with increased risk of incident AD in the two communities.

METHODOLOGY

A two-stage design with initial screening using the CSI'D followed by neuropsychological test battery, relations' interview and physician assessment in a sub-sample.NINCDS-ADRDA criteria were met for AD. The risk factor variables assessed included demographic, lifestyle, medical and family history items.

RESULTS

In the Yoruba, AD was associated with age (OR = 1.07) and female gender (OR = 2.93). In African Americans, age (OR = 1.09) and rural living (OR = 2.08) were the significant risk factors, while alcohol was protective (OR = 0.49).

DISCUSSION

Age was a significant risk factor for AD at both sites. The higher risk of incident AD in the Yoruba female, and in African Americans who resided in rural areas in childhood were similar with the prevalence cases. Alcohol emerged a protective factor in African Americans. More studies are required, including biological measurements, to adequately explain the differences in rates.

Baseline measurements of indicators for sublethal effects of metals in lake whitefish (Coregonus clupeaformis)

Histological and metallothionein (MT) analyses of liver and kidney and measurements of serum electrolytes and hematocrit from lake whitefish (Coregonus clupeaformis), 3.5 years of age, were conducted over a 90-day period that included maximal gonadal maturation in females. Condition factors were higher in females at day 1 and when all data were combined over the 90-day sampling period. Significant differences between females and males of 1.8-fold in hepatic MT concentrations were observed at day 20 when ovaries appeared to be in the most advanced state of maturation, although this parameter was not quantified. Hematocrits were slightly but significantly lower at day 90. No sex differences were observed in the quantitative assessments of epithelium cell height, lumen diameter (LD), tubule diameter (TD), and ratio of LD:TD in the second segment of the proximal tubule (P2); and of hepatocyte area, hepatocyte nuclear diameters, and nucleus area:cytoplasmic area (N:C) ratio. Positive correlations were observed between N:C ratios and fish weight, fork length, and liver weight. No significant correlations between these histological morphometrics and MT concentrations were observed in liver or kidney. The results of this study provide baseline information for investigations designed to determine sublethal effects of metals in lake whitefish.

Toxicology of dietary nickel in lake whitefish (Coregonus clupeaformis)

The sublethal toxicity associated with exposure of adult lake whitefish (Coregonus clupeaformis) to diets containing 0, 10, 100, and 1000 microg Ni per g for 10, 31, and 104 days was assessed through the measurement of responses, through a range of levels of biological organization. The accumulation and distribution of Ni in these fish are described in the previous manuscript (Ptashynski and Klaverkamp, 2001. Aquat. Toxicol. in press). Hematological parameters, including concentrations of glucose and hemoglobin and hematocrit, were not different between control and treated fish. Organ and whole organism parameters, including LSI, growth, and condition factor, were also unaffected. Histopathological lesions in kidney and liver proved to be the most sensitive and reliable indicators of Ni exposure. In livers of treated fish, areas of focal necrosis and altered bile ducts were observed. Histological alterations were observed throughout the posterior kidneys, in glomeruli, tubules, collecting ducts, and hematopoietic tissue, in fish fed medium and high dose diets. In whitefish kidneys, the frequency (%) of altered distal tubules and fields of views with alterations increased with the dose and duration of exposure. Significant increases in metallothionein concentrations were observed in intestine of whitefish fed the high dose diet on day 10, but these increases were not sustained. Significant increases in lipid peroxide concentrations were also observed in plasma of whitefish fed the high dose diet on day 31, but were not observed on day 104. These biochemical responses to dietary Ni require further evaluation. To evaluate exposure of natural populations of fish to Ni, analysis of Ni in kidney and liver and assessment of renal and hepatic histopathology are recommended for use in field bio-monitoring programs.

The accumulation, distribution, and toxicological effects of dietary arsenic exposure in lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush)

A 20-day experiment was conducted to compare the accumulation, distribution, and toxicological effects of dietary As, as arsenate, in lake whitefish (LWF, Coregonus clupeaformis) and lake trout (LT, Salvelinus namaycush). Results of this experiment were used to design an experiment of longer duration in which one of the fish species was selected and exposed three times per week to lower dietary As doses. In the present study each treatment group was exposed to a combination of one of three doses of As (0, 100, or 1000 microg As/g) and one of two types of diet, no brine shrimp (NS) or with brine shrimp (WS) for a total of eight dosing events. Brine shrimp were added to determine whether their presence enhanced consumption of As-contaminated food. Modified feeding behavior occurred in both fish species fed As contaminated diets, with the exception of the 100 microg As/g NS food. Brine shrimp addition did not affect feed consumption of the As contaminated diets. Significant As accumulation occurred in stomach, pyloric caeca, intestine, liver, kidney, and gallbladder, but not in bile or muscle. As exposure did not have a significant effect on hepatic and renal metallothionein concentrations. Concentrations of lipid peroxides were only significantly elevated in the plasma of LT fed the 1000 microg As/g WS food. Liver somatic indices decreased significantly in both species, whereas hematological parameters were not affected in either species. Histological lesions occurred in gallbladder, liver, kidney, pyloric caeca and intestine from LWF. These lesions were not observed in LT; however, gallbladders were not examined in this species. Weight gain was lower in both species fed As contaminated diets, however, condition factors were not affected.

Altered distribution of lipid-soluble antioxidant vitamins in juvenile sturgeon exposed to waterborne ethynylestradiol

Studies in mammals have shown that exposure to estrogenic compounds can affect lipid metabolism and plasma concentrations of lipid-soluble vitamins. However, the potential for estrogenic contaminants to induce these effects in fish has not yet been examined. The ability of the estrogen analog ethynylestradiol (EE2) to alter concentrations of the lipid-soluble vitamins A and E in plasma, liver, and kidney was investigated in juvenile lake sturgeon (430 +/- 20 g). The EE2 was delivered to the sturgeon in the tank water at nominal concentrations of 0 (control), 15, 60, or 125 ng EE2/L for a period of 25 d. Concentrations of the egg yolk precursor, vitellogenin, increased dose dependently in plasma. Plasma vitamin E (tocopherol), A1 (retinol), and A2 (dehydroretinol) were elevated by the two highest EE2 treatments compared with the controls. Esterified storage forms of vitamin A were marginally lower in the livers of fish from the highest EE2 dose group, but vitamin E levels in the liver were not significantly affected. Concentrations of vitamin E and vitamin A were significantly depleted in the kidney of fish from the two highest EE2 dose groups. Total lipid content was elevated in the gonad of fish treated with the highest dose of EE2 compared with the controls. Altered lipid and vitamin distribution may be induced by estrogen to facilitate gonadal maturation in sturgeon. Results from these studies indicate that an examination of the implications for vitamin depletion by estrogenic contaminants in juvenile fish is warranted.

Vitamin and thyroid status in arctic grayling (Thymallus arcticus) exposed to doses of 3,3',4,4'-tetrachlorobiphenyl that induce the phase I enzyme system

Induction of phase I biotransformation enzymes is recognized as a hallmark response in fish exposed to coplanar PCBs. Depletions of vitamins A and E and disrupted thyroid hormone and glandular structure secondary to this induction have not yet been examined in an arctic fish species. Arctic grayling were exposed to a single oral dose of 0 (control), 10, 100 or 1000 ng 3,3',4,4'-tetrachlorobiphenyl (TCB) g(-1) bodyweight, a contaminant found in most arctic fish. After 30 and 90 days of exposure, TCB concentrations in tissues, hepatic phase I activity (as ethoxyresorufin-O-deethylase (EROD)), plasma and tissue vitamin A and E concentrations, plasma thyroid hormone levels and thyroid glandular structure were examined. Total plasma osmolality, as an indicator of overall fish health was also monitored. TCB recovery in tissues was low and extremely variable, making comparisons between intended dose groups inappropriate. Therefore, correlation analysis between actual recovered TCB concentrations and biochemical responses was employed. Hepatic EROD activity correlated strongly with liver TCB concentrations. Liver concentrations of vitamin A were altered as a function of TCB concentrations and EROD activity, but plasma vitamin A status was not affected. Vitamin E was depleted by TCB accumulation in blood and EROD induction in liver of males only at 90 days postexposure. Thyroid hormones status and glandular structure were not affected by the short duration TCB exposures used in this experiment. TCB concentrations were correlated with an elevation in plasma osmolality. Results from this experiment indicate that the vitamin status and osmoregulation of arctic grayling exposed to TCB can be compromised. Further studies of field populations exposed to this type of contaminant are warranted.

Accumulation, distribution and toxicology of dietary nickel in lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush)

An 18-day experiment was conducted to investigate the uptake and sublethal toxicity of dietary Ni in adult lake whitefish (LWF, Coregonus clupeaformis) and lake trout (LT, Salvelinus namaycush) fed diets containing 0, 1000 and 10000 microg Ni/g, prepared with and without brine shrimp. The results of this experiment were used to design an experiment of longer duration in which one of the fish species was selected and exposed to lower dietary Ni doses. In the present study feed refusal was observed in LT and LWF fed 10000 microg Ni/g, after three and 4-5 feedings, respectively. LT fed Ni-contaminated diets exhibited different patterns of Ni accumulation than LWF. Increased Ni concentrations in all LWF tissues, except the intestine, were associated with increased doses of Ni. Copper and Zn concentrations in kidney and liver of LWF were altered. Metallothionein concentrations in kidneys of LT fed 1000 microg Ni/g and 10000 microg Ni/g and LWF fed 10000 microg Ni/g and in livers of LWF fed 10000 microg Ni/g (diet without shrimp only) increased significantly. Increased lipid peroxide production in the plasma of LT fed 10000 microg Ni/g was observed. Blood glucose and electrolytes were affected by Ni exposure. Histopathological alterations were observed in kidneys of LWF fed low and high dose diets, livers of whitefish fed high dose diets, and intestines of LWF fed high dose diets and LT fed low and high dose diets. LT fed high dose diets exhibited significant decreases in weight.

Examination of the behavior and liver and thyroid histology of juvenile rainbow trout (Oncorhynchus mykiss) exposed to high dietary concentrations of C(10)-, C(11)-, C(12)- and C(14)-polychlorinated n-alkanes

Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to high dietary concentrations of six polychlorinated n-alkane (PCAs) (C(10)H(15.5)C(6.5), C(10)H(15.3)Cl(6.7),C(11)H(18.4)Cl(5.6),C(12)H(19.5)Cl(6.5),C(14)H(24.9)Cl(5.1) and C(14)H(23.3)Cl(6.7)) for 21 to assess their effects on behavior and liver and thyroid histology and for 85 days to assess histology for a longer term exposure. This is the first histological work using PCAs of known carbon chain length and chlorine content and the first effort to examine the histopathology of fish exposed to PCAs. PCAs, also known as chlorinated paraffins, are complex industrial products for which there is a lack of toxicological data on individual congeners. With the exception of trout exposed to C(14)H(24.9)Cl(5.1), which had much lower exposure concentrations, many of the trout exposed to the PCAs (whole fish concentrations 0.22-5.5 microg g(-1)) showed a diminished or no startle response, loss of equilibrium, and developed a dark coloration. These responses are indicative of a narcotic toxicological mode-of-action. Histopathological lesions were observed in the livers of trout from each exposure group. However, the most severe histopathologies were observed in the livers of fish exposed to C(10)H(15.3)Cl(6.7) and C(11)H(18.4)Cl(5.6) (whole fish concentrations 0.92 and 5.5 microg g(-1), respectively), in which extensive fibrous lesions were present that were not observed in any other exposure group. Other alterations observed in all treatment groups included hepatocyte necrosis, sites of inflammation, and glycogen/lipid depletion. The relative sizes of hepatocytes of PCA exposed trout were smaller than control trout, although only a few of the observed differences were statistically significant. No lesions were present in the thyroid, although trout exposed to C(10)H(15.5)Cl(6.5) (whole fish concentration 0.84 microg g(-1)) had slightly more active thyroids, as indicated by an increased mean thyroid epithelium cell height relative to controls. It would appear that PCA toxicity is inversely related to carbon chain length, as has been observed in similar studies using mammals. The concentrations in the fish from this experiment were at levels that have been reported in invertebrates and fish from contaminated sites in the Great Lakes. However, the exposure concentrations were likely much greater in these experiments compared with the environment and require further study.

Physical, psychological and social well-being of women with breast cancer: the influence of disease phase

While research exists on the well-being of women during a specific phase of breast cancer, little research exists in which researchers utilized the same instruments to examine differences in women's well-being, based on the phase of their breast cancer. Using a trajectory framework, the purpose of this study is to examine the differences in the physical and social well-being of women during the following breast cancer states: newly diagnosed, adjuvant therapy, stable disease and recurrent disease. The convenience sample consisted of 35 women newly diagnosed with breast cancer, 52 women with breast cancer undergoing adjuvant therapy, 84 women whose breast cancer was considered stable and 64 women with recurrent breast cancer. Participants completed a packet of questionnaires which contained a demographic questionnaire, Short Form-36 (SF-36) Health Survey, a researcher designed (RD) questionnaire, Cancer Rehabilitation Evaluation System-Short Form (CARES-SF) and the Brief Symptom Inventory (BSI). Descriptive statistics, analysis of variance, and general linear F-tests were used to analyze the data. Differences were found across phases of disease on various subscales, including those representing perceived health states, overall impact, medical interactions, physical function, role function, fatigue, pain, social function and satisfaction with health. No significant differences were found between groups on the BSI subscales with the exception of somatization, global psychosocial measures, sexual and marital relation subscales. While individuals with recurrent disease often experienced more difficulties with their well-being than women in the other groups, women newly diagnosed and in the adjuvant group experienced more difficulties in select areas of well-being when compared with women in the stable group. Health care professionals need to recognize differences between groups to better meet the needs of patients with a breast cancer diagnosis.

Toxicology of dietary uranium in lake whitefish (Coregonus clupeaformis)

Using responses ranging from whole animal to the molecular level, the toxicological significance of the accumulation and distribution of uranium (U) in adult lake whitefish fed a commercial diet contaminated with three concentrations of U, 100, 1000 and 10000 µg U/g, for 10, 30, and 100 days, as described in the previous manuscript (Cooley, H.M., Klaverkamp, J.F., 2000. Accumulation and distribution of dietary uranium in Lake whitefish (Coregonus clupeaformis), Aquat. Toxicol., 48, 375-392), was evaluated. Whole organism morphometrics were unaltered by U exposure. Haematological variables were either unchanged or only transiently affected. Liver and kidney metallothionein concentrations were largely unaltered. Concentrations of serum lipid peroxides were significantly elevated in all treatment groups on days 30 and 100, indicating that U may damage cellular and sub-cellular membranes. Dose- and duration-dependent histopathologies were present in liver and posterior kidney of treated lake whitefish. The most consistent and pronounced lesions in liver were focal hepatocyte necrosis and alterations of bile ductule epithelium. Dose- and duration-dependent renal lesions were most evident in proximal tubules. However, we observed a range of histopathologies in this organ, including tubular necrosis, inflammation, haemorrhaging, depletion of haematopoietic tissues, alterations of distal tubules and collecting ducts, tubule dilation, pigmented macrophage proliferation, and glomerular lesions. Pathologies were observed in lake whitefish at all concentrations of dietary U following prolonged exposure. When used in conjunction with U tissue residue analyses, histopathological lesions and indices of lipid peroxidation may prove useful indicators of U toxicity when assessing fish health in U biomonitoring programmes.

Evaluation of two forms of sustained release nifedipine using 24 h ambulatory blood pressure monitoring

Therapeutic interchange between the available forms of sustained release nifedipine (osmotic-pump and coat-core forms of nifedipine) is a matter of controversy. This study was initiated to determine whether there is a difference in clinical outcomes when there is interchange between the two forms of sustained release nifedipine when used for the treatment of hypertension. A total of 43 patients with a history of stage I hypertension who were receiving stable doses of the osmotic-pump form of nifedipine for > 3 months with controlled blood pressures (< 150/90 mm Hg) were enrolled. Patients were then switched to the same dose of the coat-core form of nifedipine and were followed for 3 months. In the 36 patients who completed the study, mean trough serum nifedipine concentrations were significantly higher with the osmotic-pump from (46.5 +/- 35.0 ng/mL) of nifedipine compared with the coat-core form (27.2 +/- 20.4 ng/mL) (P < .05). However, blood pressure control as determined by the indices of 24 h ambulatory blood pressure monitoring, trough blood pressures and load blood pressures were similar between the osmotic-pump and coat-core forms of nifedipine. The coat-core form of nifedipine was discontinued in four patients for possible side effects. In this group of patients with mild hypertension, there were no clinically relevant differences in blood pressure control between the two forms of nifedipine. Some patients on the coat-core form of nifedipine may need to discontinue therapy due to intolerable side effects.

The annular tinted contact lens syndrome: corneal topographic analysis of ring-shaped irregular astigmatism caused by annular tinted contact lenses

PURPOSE

Irregular corneal astigmatism has been reported in association with annular tinted hydrogel contact lenses. We report the abnormal videokeratographic findings of five patients wearing annular tinted contact lenses, who presented with bilateral blurred vision and revealed a loss of best corrected visual acuity.

METHODS/RESULTS

The corneal topographic analysis revealed a previously unreported distinct ring-shaped pattern of irregular astigmatism. The topographic circular band of irregular astigmatism was further characterized by concentric areas of relative steepening, flattening, and steepening with a diameter of approximately 4 mm. This pattern suggests that forces acting at the junctional zone between the tinted area and the clear pupillary area are inducing structural abnormalities of the corneal surface. At the time of presentation, the mean surface regularity index (SRI) was 2.06 (range: 0.61-5.88). The topography and best-corrected visual acuity returned to normal within days of discontinuing annular tinted lens use, and the mean SRI decreased to 0.44 (range: 0.21-1.16). Digital imaging of lenses obtained from our patients and of identical control lenses was performed. A masked analysis suggested that the study lenses contain greater amounts of pigment compared to the control lenses.

CONCLUSIONS

We present ten characteristic signs and symptoms of this condition, which we have named "the annular tinted contact lens syndrome." Corneal topographic analysis is a powerful tool for detecting specific reversible irregularities of the corneal surface associated with the use of annular tinted contact lenses.

Clinical and overnight corneal swell comparison of the 1-Day Acuvue lens versus the Medalist, Surevue, Biomedics, and Acuvue lenses

PURPOSE

We characterized the clinical performance of the 1-Day Acuvue contact lens by direct comparison with four frequently prescribed daily wear lenses.

METHODS

Forty-eight patients participated in four prospective, randomized masked clinical trials using the 1-Day Acuvue in one eye and the Medalist, Surevue, Acuvue (regular), and Biomedics 55 lenses in the other eye. Each trial lasted 2 weeks. Thirteen symptom variables and overall lens preference were evaluated using a patient preference questionnaire and a symptom-ranking questionnaire. Overnight corneal swell studies were also performed.

RESULTS

In the non-allergic (58.4%) subgroup, the overall lens preference variable revealed a significant preference for the Medalist (P = .004), Surevue (P < .001), and Biomedics 55 (P < .001) lenses. In contrast, in the allergic (41.6%) subgroup, the overall lens preferences for the Medalist, Surevue, and Biomedics 55 lenses were completely absent. Multivariate regression analysis in the non-allergic subgroup revealed that lens comfort (.58, P < .001), lens handling upon insertion (.41, P < .001), and quality of vision (.35, P < .001) were significant variables contributing to patient responses regarding overall lens preference. However, in the allergic subgroup, only the lens comfort (.92, P < .001) variable is significant and appears to dominate the decision making. The overnight corneal swell evaluation revealed no significant differences between the 1-Day Acuvue and the Medalist lens. Patients wearing regular Acuvue had significantly less corneal swelling upon awakening (P = .005) and at 60 minutes after awakening (P = .003).

CONCLUSIONS

The Medalist, Surevue, and Biomedics 55 lenses outperformed the 1-Day Acuvue lens in the non-allergic subgroup. In the allergic subgroup, there was no statistically significant difference between the 1-Day Acuvue lens and all other lenses tested.

Antiphospholipid syndrome presenting as episodic limb ischaemia

A child presented with ischaemic episodes of his left leg from the age of 2 months. He was found to have raised anticardiolipin antibodies so was started on low dose aspirin. At a three year follow up he was asymptomatic with a normal anticardiolipin antibody level while taking aspirin daily, probably for life.

Reliability, validity, and responsiveness of functional tests in patients with total joint replacement

BACKGROUND AND PURPOSE

High-quality measurements are needed to develop meaningful clinical practice databases to assess the effectiveness of physical therapy. This study determined the reliability, validity, and responsiveness of measurements obtained with five functional tests graded with the newly developed Iowa Level of Assistance Scale.

SUBJECTS AND METHODS

Eighty-six patients with total hip or knee replacements were tested at various time periods during their hospitalization. Patients were tested for five functional activities by four therapists to establish the reliability and test responsiveness. The Harris Hip Rating Scale was administered to assess the validity of the functional score.

RESULTS

The weighted Kappa statistic supported good intratester (K = .79-.90) and moderate intertester (K = .48-.78) reliability. The correlation between the Harris Hip Rating Scale scores and the total functional scores was high (r = -.86). The total functional score was responsive to 4 days of therapy postoperatively.

CONCLUSION AND DISCUSSION

The assessment of function using the Iowa Level of Assistance Scale was shown to be highly reliable, valid, and responsive in patients following total hip or knee replacements.

Constipation and spina bifida occulta: is there an association?

Spina bifida occulta (SBO) is an abnormality in the posterior arch formation, most commonly found at the level of the S1 vertebra. It has recently been implicated in the aetiology of urinary voiding problems. We have therefore investigated its incidence in female patients with constipation due to outlet obstruction (anismus) and slow colonic transit. The plain abdominal radiographs of 52 females with constipation, and 48 age-matched controls were reviewed by one radiologist, looking for both the incidence of SBO and the incidence of abnormally high posterior sacral arc opening (S3 and above) in each group. Seventeen (32.6%) patients compared to 11 (22.9%) control subjects had SBO (chi 2 1.183, P = 0.4). Fourteen (26.9%) patients compared to six (12.4%) control subjects had an abnormally high posterior sacral arc opening (chi 2 2.406, P = 0.2). Three of seven patients (42.6%) with anismus were found to have SBO. Of 19 patients with slow colonic transit five (26.2%) had SBO and of seven patients with a mixed picture, three (42.6%) had SBO. There was no significant difference in the incidence of SBO in any of these three patient subgroups when compared to the control group. These results suggest that there is no association between spina bifida occulta and constipation.

The influences of attitudes, beliefs and label information on perceptions of reduced-fat spread

A sample of 101 consumers completed questionnaires assessing use, attitudes and beliefs with regard to full- and reduced-fat (FF and RF) spreads. In sensory tests, they rated liking of selected attributes and overall liking of a RF spread sample labelled as "reduced-fat spread 40% fat" or "full-fat margarine 80% fat". The amount spread onto bread was also determined. Other than an effect on likelihood of consumption, there were no consistent effects of label alone on any of these measures. However, analyses of sensory and hedonic ratings revealed consistent interactive effects of label information with consumer attitudes, beliefs, and (to a lesser degree) with the type of spread normally used. Eating restraint and body composition were generally unrelated to sensory ratings and response to label information. The overall effect of label information was to shift sensory judgments in a direction more consistent with an individual's beliefs; i.e., hedonic responses from subjects with more positive attitudes toward RF or FF spreads were significantly greater in the respective label condition. Given this potential differential influence of labelling, we recommend that consumer trials manipulating provision of information should include measures assessing subjects' attitudinal characteristics.

Effective outpatient use of polyethylene glycol-electrolyte bowel preparation for radical cystectomy and ileal conduit urinary diversion

In this prospective study we examined the oral electrolyte-overload method of bowel preparation for patients who were to undergo radical cystectomy and ileal conduit urinary diversion. We found it to be a safe and effective mechanical bowel preparation that can be used by outpatients. It was well tolerated and resulted in adequate bowel cleansing and a low incidence of postoperative wound infections and pyelonephritis. A major advantage of this method is that it reduced the period of preoperative hospitalization.

Effect of transcutaneous electrical nerve stimulation characteristics on clinical pain

We compared the effects of four treatment variables on the pain reduction produced by transcutaneous electrical nerve stimulation and attempted to establish indications for TENS based on patient history and pain evaluation items. Treatment variables were the therapist and the three TENS stimulus characteristics--pulse width, frequency, and amplitude. We randomly assigned 192 consecutive adult patients suffering from painful conditions to one of four physical therapists and one of 12 stimulus characteristic combinations. We used a standard evaluation form that included a visual analog scale (VAS) to evaluate pain. Patients were given a 30-minute trial using TENS, followed by reevaluation. The VAS line length change after treatment was the criterion score for comparison of stimulus characteristic effectiveness. Although pain was reduced greatly with TENS (p = .01), a four-way analysis of variance (pulse width, frequency, amplitude, and therapist) attributed little of the treatment effect to the treatment variables or their interactions (r2 = .101). The amplitude effect, however, was borderline (p = .056), and subthreshold stimulation proved more effective than stimulation to tolerance (p = .05). Extensive multiple linear regression analyses failed to provide indications for TENS based on patient information and pain evaluation items. Therefore, pain remains the only indication for TENS, and we recommend subthreshold rather than higher amplitude stimulation on the initial TENS trial.

Congenital dislocation of the hip: early and late diagnosis and management compared

During the decade 1970-9, 23 002 infants born in the University of Bristol Department of Obstetrics were examined for congenital dislocation of the hip by junior members of the paediatric staff on the first day of life and again on discharge from hospital. Suspected hip abnormality was checked by a senior member of the staff on the same day. A total of 445 (1.9%) infants were found to have a hip abnormality in the neonatal period. Immediate treatment in an abduction splint was undertaken, usually six weeks for dislocatable hips and 12 weeks for dislocated hips. Routine follow up included clinical and radiological examination at six, 12, 24, and 60 months. Altogether 90% completed the 12 month, 85% the 24 month, and 76% the 60 month checks. Five infants (1.1%) required further orthopaedic treatment (adductor tenotomy and abduction splinting) but no major surgery was necessary, nor was avascular necrosis encountered. The radiological results were excellent. Every effort (1970-84) was also made to identify all cases of late congenital dislocation of the hip diagnosed after the neonatal period in infants born to women in Avon during the same decade (n = 103 431). Ninety one cases were detected (0.88 per 1000 births), 10 in the university cohort (0.44 per 1000) and 81 in the non-university group (1.00 per 1000) (P less than 0.01). Seven of 10 in the former group required open surgery and in seven the radiological outcome at follow up was moderate or poor. The early and late diagnosed groups are compared in respect of perinatal factors and management. It is possible to detect most cases of congenital dislocation of the hip at birth and treat them safely and successfully.

The characteristics of the electro-olfactogram (EOG): its loss and recovery following olfactory nerve section in rainbow trout (Salmo gairdneri)

Electro-olfactograms (EOGs) were recorded from both sensory and non-sensory epithelia on the olfactory lamellae and from other areas within the rosette of rainbow trout (Salmo gairdneri). The trout EOG induced by amino acids was a monophasic negative voltage composed of a phasic component which declined to a steady level (tonic component) that was maintained throughout stimulus duration. The time period (2 min) for complete recovery of the EOG was obtained by applying two identical stimuli (10(-5) mol/liter L-serine for 5 s) successively at increasing intervals. EOG response to amino acids increased nearly exponentially with concentration and no saturation was reached. Gradual deterioration of olfactory receptor cells occurred within 14 days after olfactory nerve section (axotomy) as indicated by phospholipid staining. Regeneration of the receptor cells started at 56 days postaxotomy, reached approximately normal density and the elongate form of mature neurons at 84 days. In axotomized fish the magnitude of EOG response decreased relative to the controls at 7 days with minimal sensitivity between 14 and 28 days postaxotomy. EOGs were not evoked by L-serine nor L-leucine in most fish 17-22 days postaxotomy. Restoration of the EOG response coincided with morphological repopulation of receptor neurons after 84 days. EOG recovery was only 50% of the control values at 230 days. The EOG responses evoked by HCl in sensory and non-sensory epithelia were indistinguishable from each other, indicating that receptor neurons are not likely to be their primary origin.

Differences in the DNA of the inactive X chromosomes of fetal and extraembryonic tissues of mice

We have examined the role of DNA modification in X chromosome inactivation of fetal tissues of the mouse using DNA-mediated gene transfer for the gene hypoxanthine phosphoribosyltransferase (HPRT). Two types of tissues have been examined with respect to randomness of inactivation in 14-day mouse conceptuses: 1) fetal tissue, which undergoes random inactivation of either the maternal or paternal X; and 2) yolk sac endoderm tissue, an extraembryonic membrane, which normally undergoes nonrandom inactivation of the paternal X. Exploiting an electrophoretic variant of HPRT as a means to mark the active and inactive HPRT alleles we provide evidence that: 1) inactive X DNA of the fetus at 14 days behaves like that of both adult tissue and cell lines in that the inactive X DNA is not efficient in gene transfer; and 2) in contrast, inactive X DNA from yolk sac endoderm is functional in gene transfer. Thus, despite the similarity in single active X chromosome expression in yolk sac endoderm and somatic tissues, there appears to be a difference at the level of DNA modification between these two tissues.

Pterygodermatites nycticebi (Nematoda: spirurida) in golden lion tamarins

Pterygodermatites nycticebi (syn Rictularia nycticebi), a spirurid nematode first described in the slow loris (Nycticebus coucang), recently has been associated with morbidity and mortality in the golden lion tamarin (Leontopithecus rosalia rosalia) collection at the National Zoological Park. Adult worms were found in the lumen of the small intestine with their anterior ends embedded in the mucosa. Larvae, when present, were deeper in the submucosa. A few heavily infected animals developed profound weakness, anemia, and hypoproteinemia. Infective larvae of Pterygodermatites nycticebi developed in laboratory-reared German cockroaches (Blatella germanica) that were fed tamarin feces containing eggs of Pterygodermatites nycticebi. Wild-caught German cockroaches also were found to harbor these infective larvae which implicates this ubiquitous pest as an intermediate host. Effective control of Pterygodermatites nycticebi has been achieved by regular fecal screening of all callitrichids for spirurid eggs and biannual prophylaxis with mebendazole at 40 mg/kg, as well as a rigorous cockroach extermination program.

Histochemical localization of phospholipids in the olfactory epithelium of fish

Histochemical localization of phospholipids in the olfactory epithelium of rainbow trout (Salmo gairdneri), whitefish (Coregonus clupeaformis), Arctic char (Salvelinus alpinus), brook trout (Salvelinus fontinalis), lake trout (Salvelinus namaycush), and black bullhead (Ictalurus melas) was examined. The present results indicate that phospholipids are highly localized in the receptor neurons of all species examined, present not only in the membranes, but also in the cytoplasm. Although the phospholipids of membranes and cytoplasm may not be of the same kind, their localization suggests a role in olfactory function. The Baker acid hematein method shows clear morphological features of the olfactory neurons beyond those obtainable by routine histological methods. The technique may be useful in determining morphological changes and (or) phospholipid alterations caused by a deleterious environment.