Characterization and anti-settlement aspects of surface micro-structures from Cancer pagurus.

Tuning surface and material properties to inhibit or prevent settlement and attachment of microorganisms is of interest for applications such as antifouling technologies. Here, optimization of nano- and microscale structures on immersed surfaces can be utilized to improve cell removal while reducing adhesion strength and the likelihood of initial cellular attachment. Engineered surfaces capable of controlling cellular behaviour under natural conditions are challenging to design due to the diversity of attaching cell types in environments such as marine waters, where many variations in cell shape, size and adhesion strategy exist. Nevertheless, understanding interactions between a cell and a potential substrate for adhesion, including topographically driven settlement cues, offers a route to designing surfaces capable of controlling cell settlement. Biomimetic design of artificial surfaces, based upon microscale features from natural surfaces, can be utilized as model surfaces to understand cell-surface interactions. The microscale surface features of the carapace from the crustacean Cancer pagurus has been previously found to influence the rate of attachment of particular organisms when compared to smooth controls. However, the nature of microscale topographic features from C. pagurus have not been examined in sufficient detail to allow design of biomimetic surfaces. In this work, the spatial distribution, chemical composition, size and shape descriptors of microscale surface features from C. pagurus are characterized in detail for the first time. Additionally, the influence of topography from C. pagurus on the settlement of marine diatoms is examined under field conditions.

The safety of peri-articular local anaesthetic injection for patients undergoing total knee replacement with autologous blood transfusion: a randomised trial.

Intra-operative, peri-articular injection of local anaesthesia is an increasingly popular way of controlling pain following total knee replacement. At the same time, the problems associated with allogenic blood transfusion have led to interest in alternative methods for managing blood loss after total knee replacement, including the use of auto-transfusion of fluid from the patient's surgical drain. It is safe to combine peri-articular infiltration with auto-transfusion from the drain. We performed a randomised clinical trial to compare the concentration of local anaesthetic in the blood and in the fluid collected in the knee drain in patients having either a peri-articular injection or a femoral nerve block. Clinically relevant concentrations of local anaesthetic were found in the fluid from the drains of patients having peri-articular injections (4.92 µg/ml (sd 3.151)). However, none of the patients having femoral nerve blockade had detectable levels. None of the patients in either group had clinically relevant concentrations of local anaesthetic in their blood after re-transfusion. The evidence from this study suggests that it is safe to use peri-articular injection in combination with auto-transfusion of blood from peri-articular drains during knee replacement surgery.

A randomised pilot trial of "locking plate" fixation versus intramedullary nailing for extra-articular fractures of the distal tibia.

The ideal form of fixation for displaced, extra-articular fractures of the distal tibia remains controversial. In the UK, open reduction and internal fixation with locking-plates and intramedullary nailing are the two most common forms of treatment. Both techniques provide reliable fixation but both are associated with specific complications. There is little information regarding the functional recovery following either procedure. We performed a randomised pilot trial to determine the functional outcome of 24 adult patients treated with either a locking-plate (n = 12) or an intramedullary nailing (n = 12). At six months, there was an adjusted difference of 13 points in the Disability Rating Index in favour of the intramedullary nail. However, this was not statistically significant in this pilot trial (p = 0.498). A total of seven patients required further surgery in the locking-plate group and one in the intramedullary nail group. This study suggests that there may be clinically relevant, functional differences in patients treated with nail versus locking-plate fixation for fractures of the distal tibia and differences in related complications. Further trials are required to confirm the findings of this pilot investigation.

Use of a lateral tibial head buttress plate to repair a tibial fracture in a labrador retriever.

A lateral tibial head buttress plate designed for human beings was used to repair a highly comminuted tibial fracture in a two-year-old male labrador retriever caused by a gunshot wound. The plate was placed in a bridging fashion to provide minimal disruption of the fracture site and minimise surgical time.

Sex differences and predictors of objective cough frequency in chronic cough.

BACKGROUND: Women are consistently over-represented in specialist cough clinics and known to have a more sensitive cough reflex than men. Whether female sex and other patient characteristics are associated with higher cough rates is not known. A study was conducted to determine the predictors of objective cough frequency in patients presenting to a tertiary referral clinic with chronic cough. METHODS: 100 subjects (65 women) of mean (SD) age 55.8 (11.0) years and median cough duration 4 years (IQR 2.0-10.0) with unexplained chronic cough completed flow-volume loops (mean (SD) forced expiratory volume in 1 s 103 (15.2)% predicted; forced expiratory flow (FEF(50)) 68.8 (24.1)% predicted), methacholine challenge (42% positive), citric acid cough reflex sensitivity (C5; 0.12 M (IQR 0.06-0.50)) and the Leicester Cough Questionnaire. 24-h ambulatory cough monitoring was performed in 86 subjects; manually counted coughs were quantified as the number of explosive cough sounds per hour. RESULTS: Women coughed significantly more than men (geometric mean 16.6 coughs/h (95% CI 13.1 to 21.0) vs 9.4 coughs/h (95% CI 6.4 to 13.9), p = 0.01)). The cough reflex was also more sensitive in women than in men (median logC5 -0.9 M vs -0.6 M, p = 0.002), but cough-related quality of life was similar in women and men (12.0 (3.6) and 12.2 (3.2), respectively, p = 0.76). Linear regression analysis showed that 38.6% of the variation in cough rate was predicted by sex (p = 0.01), logC5 (p<0.001) and age (p = 0.002) but not lung function or bronchial hyper-reactivity. CONCLUSIONS: Ambulatory objective cough monitoring provides novel insights into factors modulating chronic cough. These findings suggest that effects of sex and age must be taken into account in the study of cough and when designing clinical trials testing novel antitussive agents.

How to quantify coughing: correlations with quality of life in chronic cough.

Different methods are used for quantifying coughing in sound recordings, but as yet no method has been shown to be more valid than any other. In the present study, the relationships between three different units of cough were examined and their ability to predict subjective ratings of cough and cough-related quality of life were evaluated. In total, 70 subjects (mean+/-SD age 55+/-11.7 yrs, 51 (73%) females) with chronic unexplained cough (median duration 4.8 yrs, interquartile range 2.5-10.1 yrs) performed fully ambulatory 24-h sound recordings, which were manually counted by trained observers and quantified by 1) explosive phases, 2) cough seconds and 3) cough epochs. Subjects also completed cough visual analogue scales (VAS) and the Leicester Cough Questionnaire (LCQ). All units of cough were strongly correlated; explosive phases and cough seconds correlated slightly more strongly than cough seconds with cough epochs or explosive phases with cough epochs. LCQ scores correlated moderately with explosive phases and seconds; epochs correlated slightly less well. Cough VAS scores showed a similar pattern. Explosive phases and seconds are interchangeable units of cough, moderately related to subjective measures and cough-related quality of life; epochs are a less satisfactory alternative.

Portable method for the determination of snoring site by sound analysis.

It has been shown that computerized sound frequency analysis can be used to distinguish between different snoring sites. The aim of this study was to investigate whether a portable recording method using audiotapes and digital minidisc formats could produce waveforms similar to a computer recording. The snores of 12 subjects in their natural sleep were recorded onto audiotape, minidisc and directly onto a computer. For each snorer and recording method 30 snore samples were analysed and their power ratio was calculated indicating the relative amount of sound below and above a set frequency. It was found that the power ratios from audiotape recordings were significantly different to those from computer recordings for all snoring sites (p = 0.0007), whereas there was no significant difference between minidisc and computer recordings (p = 0.41). These results indicate that it would be possible to base a portable snore analysis system for site determination on minidisc, but not on audiotape recordings.

Sound frequency analysis and the site of snoring in natural and induced sleep.

The aim of this study was to compare the snoring sounds induced during sleep nasendoscopy, and to compare them with those of natural sleep using sound frequency spectra. The snoring of 16 subjects was digitally recorded during natural and induced sleep, noting the site of vibration during sleep nasendoscopy. Patients with palatal snoring during sleep nasendoscopy had a median peak frequency at 137 Hz (118 snore samples). The peak frequency of tongue-base snoring was 1243 Hz (10 snore samples), and simultaneous palate and tongue was 190 Hz (six snore samples). The median power ratios were 7, 0.2 and 5 respectively. The centre frequencies were 371, 1094 and 404 Hz respectively. Epiglottic snores had a peak frequency of 490 Hz (five snore samples). Comparison of the induced (n = 118) and natural (n = 300) snore samples of the 12 palatal snorers showed a significant difference in both the power ratio and centre frequencies (P = 0.031 and P = 0.049). The peak frequency position was similar (P = 0.34). Our results indicate that induced snores contain a higher frequency component of sound, not evident during natural snoring. This is consistent with an element of tongue-base snoring. Although there is good correlation generally, sleep nasendoscopy may not accurately reflect natural snoring.

Technical note: a compact data logger for ambulatory skin temperature measurement.

A miniature, body-worn data logger has been developed for multi-channel recording of small changes in skin surface temperature. The unit has been designed for small size, long battery life and high accuracy together with full programmability and an infra-red (contactless) transfer of parameters and data. Temperature is measured using thermistors with a resolution of 0.005 degrees C and an absolute accuracy of better than 0.05 degrees C. A comprehensive software package running on a laptop PC is used for initial setting of the logger parameters and downloading and displaying the temperature data. The present system records eight channels of temperature at intervals from 30 seconds to 99 minutes. It contains 64 K bytes of non-volatile memory allowing 3274 sets of readings including subject identification, battey status, date and time. The logger size is 55 mm x 31 mm x 9.5 mm and weighs 20 g.

State-mandated voluntary newborn human immunodeficiency virus screening in a New York City Hospital.

OBJECTIVE: To report the experience with state-mandated voluntary newborn human immunodeficiency virus (HIV) screening in a large university hospital. METHODS: Retrospective analysis of delivery records and newborn HIV screening data for infants born between May 4, 1996, and January 31, 1997. RESULTS: Of 3111 women, 40% had HIV testing during pregnancy, 28% had testing before pregnancy, 30% never had testing, and 2% gave no information. Most (91%) consented to postpartum newborn HIV testing, although rates varied by HIV counselor (range 81-96%, P < .001) and maternal HIV testing history (range 72-94%, P < .001). Maternal antepartum HIV testing rates varied by delivering physician (range 8-100%, P < .001) and by antepartum care site (clinics, 83%; faculty practices, 72%; private practices, 57%; P < .001). Fourteen HIV-exposed infants (0.46% of infants tested) were identified, 13 of whom were born to women known to be HIV positive before delivery. These women had received zidovudine prophylaxis according to Adult AIDS Clinical Trials Group 076 guidelines. All 14 infants subsequently tested negative for HIV. Human immunodeficiency virus-positive women were more likely than HIV-negative women to have received antepartum care in clinics (93% compared with 11%), have care paid by Medicaid (93% compared with 28%), and reside in high-risk areas (72% compared with 11%) (P < .001). CONCLUSION: Newborn HIV screening has little incremental impact in settings with aggressive antepartum screening and/or low HIV infection rates. Interventions to increase antepartum HIV screening in the private sector should be implemented.

Dispersal, establishment and survival of Ceriops tagal propagules in a north Australian mangrove forest.

Studies of the ecology of mangroves show that a wide variety of factors, including salinity, desiccation, disturbance, competition and predation, may affect the distribution and abundance of species. Field studies were done to examine the relative importance of several of these factors in the establishment and early survival of Ceriops tagal, a species common in mid-to high-shore regions of mangrove forests in northern Australia. The fate of marked and tethered propagules was followed to estimate the range of dispersal and the intensity of predation. Propagules were artificially planted under different thicknesses of shade cloth (none, 30%, 80%) and in different habitats (clearing, forest, clearing-forest fringe) to examine the effects of light and soil conditions on survival and growth. Results suggested that dispersal was very limited: only 9% of marked propagules were ever found more than 3 m from the parent tree. Losses to predators were great, with 83% of tethered propagules being damaged or consumed within 3 months. On average, 56% of planted propagules survived for at least 6 weeks and 76% of these initiated growth. Survival in clearings was lower than in other habitats, with 29% fewer surviving six weeks and 48% fewer surviving 15 months. The growth of seedlings was correlated with soil temperature, but the effects of treatments were complex. Overall, results indicated that poor dispersal and establishment were the main factors likely to limit the colonisation and population growth of this species.

Practical limitations of the Deltatrac indirect calorimeter.

Indirect calorimetry is used to assess energy requirements. The Deltatrac Metabolic Monitor is a relatively inexpensive indirect calorimeter which uses a 'fixed' flow of ambient air to collect expired air. Only oxygen and carbon dioxide concentrations are measured and the 'fixed flow' is assumed in the calculation of oxygen consumption ((.)VO(2)) and carbon dioxide production ((.)VCO(2)). Using inert gas dilution we have studied the effect on (.)VO(2), and on the variability in (.)VO(2), of changing and lengthening the 1.77 m length of 35 mm tubing supplied with the instrument to collect expired air, and of using a mask to collect expired air instead of the manufacturer's hood. One would anticipate that changing the tubing could cause a change in resistance to gas flow and thus affect the true flow rate. This would alter the gas concentrations seen by the analysers, but the 'fixed flow' would still be assumed so the results would be in error. Adding extra lengths of manufacturers tubing caused an apparent rise in (.)VO(2) of 0.36%/m of tubing added, and using 22 mm tubing instead of the manufacturer's 35 mm tubing increased (.)VO(2) by 0.42% for each 10 cm of tubing added. Using the mask to collect expired air instead of the canopy (.)VO(2) was higher, possibly due to the energy cost of holding the mask, and was more variable, probably because of poorer mixing of the expired air. To measure (.)VO(2) using a mask with the same precision as a 10 min measurement made with the hood would entail measuring (.)VO(2) for 14.5 min. The methods used to collect expired air (mask or canopy, length and type of tubing) when measuring metabolic rate with the Deltatrac do affect the results obtained but these effects are small and predictable.

Genital ulcer disease in women infected with human immunodeficiency virus.

OBJECTIVE: The purpose of this study was to determine the prevalence and microbiologic characteristics of genital ulcer disease in a population of human immunodeficiency virus-infected women. STUDY DESIGN: A retrospective cohort study was performed in university-affiliated, hospital-based women's human immunodeficiency virus clinics. A total of 307 women with human immunodeficiency virus infection were followed up during 20 months. There were no interventions. Age, race, CD4+ cell counts, bacteriologic and virologic analyses in cases of ulcers, serologic testing for syphilis, and histopathologic examination in selected cases (n = 6). RESULTS: Among 307 women followed up over a 20-month period, 43 ulcers were detected with a prevalence of 14%. Among the ulcer cases the average absolute CD4+ lymphocyte number was 210/mm3. Diagnostic evaluation yielded no proven etiologic agent in 26 (60%) of the cases. Twelve of the 43 cases (28%) were positive for herpes simplex-2. Five cases (12%) yielded unusual or mixed bacteriologic types. No cases were attributable to primary syphilis infection. One case each of an ulcer infected with cytomegalovirus, Chlamydia trachomatis, and Gardnerella vaginalis, as well as three unusual presentations of herpetic ulcers, is analyzed in detail. CONCLUSION: These cases exemplify the often dramatic presentation of human immunodeficiency virus-related genital ulcers and the clinical complexity of both diagnosis and management. The frequent lack of an infectious or neoplastic cause in human immunodeficiency virus-infected women with genital ulcer disease suggests that human immunodeficiency virus may play a local role in causation or exacerbation. Biopsies of atypical genital ulcers should be considered to aid diagnosis. Further studies are needed to elucidate the pathogenesis of genital ulcer disease in human immunodeficiency virus-infected women.

Development of an indirect calorimeter for use in infants and young children.

A low cost, 'open-circuit', flow-through system, using a closely fitted facemask has been developed for the determination of oxygen consumption and carbon dioxide production in spontaneously breathing infants and children.

Disturbance and organisms on boulders : I. Patterns in the environment and the community.

Several aspects of disturbance by waves to intertidal boulders were monitored for one year high and low on the shore on two rock platforms on the east coast of Australia. These boulders were also subjected to burial by sand, and this disturbance was monitored in the same places for two years. The mobile and sessile organisms on the tops and bottoms of the rocks were sampled six times during the same period in order to determine patterns in community structure and assess the role of disturbance. Small rocks were overturned more often and buried to a greater extent than large rocks, but rocks of all sizes were moved similar distances with similar frequency. These contrasting results were probably caused by the fact that small rocks were rounder than large rocks. Rocks were buried in sand much more at Long Reef than at Cape Banks, but differences among places in disturbance by waves were not great.Patterns in community structure were complex but suggested that disturbance was only important for sessile organisms on the undersides of boulders. The number of sessile species present was always related to the size of the rock but the total cover of algae on the tops of rocks never was. Some particular species were most abundant on large rocks but others showed the reverse pattern, covering more space on the smaller boulders. This latter pattern may have been due to the shorter period of exposure during low tide in this situation, though grazers were also abundant on these rocks in some places. In contrast, nearly all species on the undersides of rocks reached greatest abundance on the medium to large rocks, consistent with effects of disturbance. Space was in short supply low on the shore and overgrowth apparently reduced diversity but this was not the case elsewhere. Overall, the results indicate that disturbance was frequent and important, but not for all species nor in all places.

Disturbance and organisms on boulders : II. Causes of patterns in diversity and abundance.

The tops of intertidal boulders on the east coast of Australia may carry a half-dozen algae, while the undersides may support a dozen or more species of sessile animals; mobile forms such as molluscs, crustaceans, and echinoderms are also common. These organisms are disturbed when boulders are moved by waves or buried in sand. Experiments were done to test the hypothesis that these disturbances are responsible for the reduced diversity and abundance of the assemblages on the undersides of small boulders. Boulders on one shore were bolted to the substratum to prevent movement by waves. In two separate experiments on another shore, boulders with and without attached organisms were buried in a few centimetres of sand. All experiments included relevant controls and were done high and low on the shore using rocks of several sizes.The assemblages of algae developing on the tops of all stabilised boulders, regardless of size, were similar to those on boulders free to roll indicating that, in contrast to results elsewhere, disturbance by waves was too infrequent or slight to affect these species. The tops of rocks were also rarely buried in sand and the main influences on the community in this situation were apparently exposure at low-tide and grazing gastropods.More species, however, did settle or survive on the undersides of rocks which were free of sand or could not be moved by waves; thus disturbances were important in this situation. In the absence of disturbance low on the shore, much or all space was occupied and sessile species such as sponges and ascidians overgrew other forms and reduced diversity. This did not happen higher on the shore and here diversity was simply an increasing function of rock-size. Overall disturbance played a similar role in all places - it killed organisms and created free space - but the final effects on the community varied depending upon the species present and the actions of other factors.

Propofol in emulsion form: induction characteristics and venous sequelae.

Propofol in a 1% emulsion was used to induce anaesthesia in 20 female patients premedicated with diazepam (10 mg). A dose of 2.5 mg kg-1 produced a rapid loss of consciousness and only minor excitatory effects. Discomfort during the injection was not severe. Cardiovascular changes included a fall in blood pressure similar to that which occurs with other induction agents, and a decrease in pulse rate. Apnoea occurred after each induction and in some patients (13) was prolonged (greater than 60 s). There were no venous sequelae, and patient acceptance was high. Propofol given in an emulsion to induce anaesthesia merits further study.

Dystrophia myotonica and atracurium. A case report.

Atracurium was used to produce neuromuscular blockade in a patient with dystrophia myotonica. Operating conditions were excellent and myotonia was not seen. Sensitivity to atracurium was not seen and spontaneous recovery was not prolonged.

Induction of anaesthesia with propofol ('Diprivan') or thiopentone and interactions with suxamethonium, atracurium and vecuronium.

A randomized study involving 60 healthy patients was performed to examine the induction characteristics and the possible interactions between propofol 2.5 mg/kg or thiopentone 4 mg/kg and three neuromuscular blocking agents, suxamethonium, atracurium and vecuronium. The time of onset to maximum blockade, the degree of blockade and the duration of blockade were measured using the electromyogram. The response to each muscle relaxant was not significantly different after induction of anaesthesia by propofol or thiopentone. A decrease in arterial blood pressure which occurred after both induction agents was greater after propofol than after thiopentone P less than 0.05. There was no significant difference in the increase in heart rate which occurred after the injection of either propofol or thiopentone.