Surgical excision of skin cancer: the importance of training

Background Skin cancers are the most common malignancy in New Zealand and their treatment imparts a huge burden on the healthcare system both in terms of the cost of surgical intervention and in treatment delivery (estimates are in excess of NZ$33 million per annum for the year 2000). Currently in New Zealand, skin cancers are excised by dermatologists, general practitioners (GPs), GPs with a special interest in skin surgery (GPSIs) and specialist surgeons with diverse training backgrounds including ear, nose and throat, ophthalmic and general surgeons. To date there is scant literature evaluating complete excision rates following surgical treatment of skin cancer between these vocational groups. Objectives To review retrospectively pathology reports from all skin excisions sent to one private pathology laboratory over three consecutive months. The aim was to investigate the margins of excision and completeness of skin cancer surgery performed by each vocational group. Methods A retrospective analysis of skin pathology reports was undertaken for a 3-month period between April and June 2007. Raw data obtained from the pathology reports included diagnosis, completeness of excision, size of specimens, body site and vocational group of the medical practitioner performing the surgery. Results In total, 1532 lesions were excised: 432 benign and 1100 malignant. Six hundred and seven were from the head and neck. Dermatologists excised 276 lesions of which 93% were malignant, 55% were from the head and neck, and 0% were incompletely excised. GPs excised 633 lesions: 63% malignant, 30% head and neck, 23% incomplete excision of malignant lesions. GPSIs excised 368 lesions: 71% malignant, 35% head and neck, 21.5% incomplete malignant excision. Specialist surgeons excised 255 lesions: 72% malignant, 53% head and neck, 20% incomplete malignant excision. Conclusion GPs and GPSIs excised more benign lesions and had higher incomplete excision rates of skin cancer surgery than dermatologists. Incomplete excision rates for the vocational groups ranged from 0% to 45% depending on site and pathology.

Effect of time of admission on compliance with deep vein thrombosis prophylaxis in a tertiary medical intensive care unit

OBJECTIVE

We sought to evaluate deep vein thrombosis (DVT) prophylaxis compliance according to time of admission in a medical intensive care unit (MICU).

METHODS

This was a retrospective cohort study at a closed tertiary MICU. We classified patients into three groups (week days, weekends, and week nights), according to time of admission. An unweighted risk factor score (RFS) was calculated from 20 known risk factors. We defined DVT prophylaxis compliance as any type of prophylaxis (mechanical or pharmacologic) for RFS 3. Non-compliance was defined as no prophylaxis or single-type prophylaxis for RFS > 3.

RESULTS

We analyzed 105 admissions. Eighty (76.19%) patients received compliant DVT prophylaxis, and 25 (23.81%) patients received non-compliant regimens of whom 11 (10.48%) were not on any prophylaxis. DVT prophylaxis compliance was not different across the three admission groups. The non-compliant DVT prophylaxis group had a higher RFS (3.48 +/- 2.1 vs. 2.25 +/- 1.5; P = 0.011), a trend towards fewer female patients (40% vs. 60%; P = 0.079), and a higher percentage of admissions by interns at the first postgraduate year (PGY) level (28% vs. 5.4%; P = 0.01). Logistic regression revealed that only RFS and PGY level were independent predictors for compliance (P = 0.015 and 0.005 respectively). Time of admission was not a significant factor.

CONCLUSIONS

Time of admission did not influence DVT prophylaxis compliance. Compliance improved with higher PGY level and lower RFS. A higher level of knowledge probably explains the association with PGY level; however, we cannot explain the inverse relationship between RFS and compliance.

Characterization of chemical coating on the functionalized carbon nanotubes

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Genetic and morphological evidence for substantial hidden biodiversity in a freshwater crayfish species complex

North America is a center of biodiversity for freshwater crayfish, with >300 described species, mostly in the family Cambaridae. However, the phylogenetic and phylogeographic relationships among these taxa are poorly understood, despite their ubiquitous occurrence in North American freshwater habitats. Here, we target the geographically widespread Orconectesvirilis and its sister taxa for genetic and morphological investigation. We used sequence data from two mitochondrial genes (16S rRNA and cytochrome oxidase I) and from one nuclear gene (glyceraldehyde-3-phosphate dehydrogenase), as well as morphological data from the male gonopod, to gain insights into phylogenetic relationships among individuals collected in the northeastern United States, where this taxon is considered to be invasive, and from Kansas. Our data reveal evidence for three cryptic species in our collections, in addition to O.virilis sensu stricto; all four clades are separated by both mitochondrial and nuclear sequence data. In addition, two of the newly discovered species, O.sp. nov. A and O.sp. nov. B, are distinguishable from O.virilis by significant differences in gonopod morphology (no data on gonopod morphology were available for O.sp. nov. C). O.sp. nov. A was collected at numerous sites in Massachusetts; additional sampling is required to determine if this species is native to New England. Two other taxa, O.sp. nov. B and O.sp. nov. C, were both collected from sites in eastern Kansas, and historically have probably been considered to be O.nais. In summary, this investigation indicates that this species complex may harbor a great deal of unknown biodiversity over the rest of its described range, and suggests that further attention to the phylogenetics and phylogeography of North American crayfishes may yield interesting insights into the evolution of biodiversity.

Renal myxozoanosis in weedy sea dragons, Phyllopteryx taeniolatus (Lacepède), caused by Sinuolinea phyllopteryxa n. sp

Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States. Myxozoan spores were visible in wet mounts of kidney tissue and were associated with renal tubular dilatation and tubular epithelial cell hypertrophy. Light and electron microscopy revealed spore morphology consistent with the genus Sinuolinea. Spores were spheroidal, slightly dorso-ventrally compressed, length (L) 17.1 x width (W) 16.4 x thickness (T) 15.6 microm, with two shell valves joined at a distinct, sinuous sutural ridge, and had two nearly spherical polar capsules, L 5.5 x W 5.0 microm, with five to seven turns of the polar filament. There were no extra-valvular ridges or protrusions. DNA sequencing required the design of three new primers that yielded 1740 bp of 18S ribosomal DNA sequence. The parasite was determined to be novel based on morphological and molecular data, and was given the name Sinuolinea phyllopteryxa after its vertebrate host.

Verbal numerical scales are as reliable and sensitive as visual analog scales for rating dyspnea in young and older subjects

This study compared the use of a simple verbal 0-10 numerical rating scale (verbal NRS) and a visual analog scale (VAS) for the rating of dyspnea during exercise in a group of young and older subjects. Twelve younger (32+/-9 yr) and 12 older (71+/-7 yr) subjects used either the verbal NRS or the VAS in a randomised fashion to rate dyspnea during 60 s of uphill treadmill walking (range 5.6-8.8 km h(-1)) performed at either a low (17% grade) or high workload (26% grade) and then during recovery. Rating scales were evaluated twice on separate days (day 1 and day 2) at each workload. While the verbal NRS scores proved to be reliable throughout exercise and recovery, VAS scores were significantly (p<0.05) lower on day 2 during the low workload test (younger group) and the high workload test (older group). Verbal NRS ratings were consistently greater than VAS ratings at both workloads (p<0.001) for both young and older groups. The intra-class correlation coefficients for rating peak dyspnea using either the VAS or verbal NRS were consistently lower for the older subjects (range: r=0.54-0.67) than the younger subjects (range: r=0.70-0.86). Overall, subjects preferred the verbal NRS to the VAS. These results suggest that the verbal NRS compares favourably with the VAS for rating dyspnea during exercise without mask or mouthpiece. However, when rating peak dyspnea both scales appear less reliable when used by the older compared to young subjects.

Continuous and intermittent exercise responses in individuals with chronic obstructive pulmonary disease

BACKGROUND

While the acute physiological responses to continuous exercise have been well documented in individuals with chronic obstructive pulmonary disease (COPD), no previous study has examined the response to intermittent exercise in these patients.

METHODS

We examined the physiological responses of 10 individuals with moderate COPD (forced expiratory volume in 1 second 52 (15)% predicted) who performed both an intermittent (1 min exercise and rest intervals) and a continuous cycle ergometer test on separate days. Both intermittent and continuous exercise tests were performed at the same power output, calculated as 70% of the peak power attained during an incremental exercise test.

RESULTS

Intermittent exercise was associated with significantly lower values for oxygen uptake, carbon dioxide output, expired ventilation, heart rate, plasma lactate concentration, and ratings of breathlessness than continuous exercise. Subjects were able to complete a significantly greater total amount of work during intermittent exercise (71 (32) kJ) than during continuous exercise (31 (24) kJ). The degree of dynamic lung hyperinflation (change in end expiratory lung volume) was significantly lower during intermittent exercise (0.23 (0.07) l) than in continuous exercise (0.52 (0.13) l).

CONCLUSIONS

The greater amount of work performed and lower measured physiological responses achieved with intermittent exercise may allow for greater peripheral training adaptations in individuals with more limited lung function. The results suggest that intermittent exercise may be superior to continuous exercise as a mode of training for patients with COPD.

Sleep apnoea and daytime function in the elderly—what is the impact of arousal frequency?

Arousals from sleep result in hyperventilation and hypocapnia that can lead to sleep apnoea. We have investigated whether sleep apnoea in the elderly is associated with more arousals compared with younger people. Additionally, the impact of arousals on daytime symptoms was noted. Four groups (n = 11) of elderly (> 65 years) and young (< 39 years) apnoeic (EA and YA), and age-matched non-apnoeics (EN and YN) were studied. The arousal index (AI) and apnoea/hypopnoea index were determined from polysomnography. Sleepiness (Epworth Sleepiness Scale) and Quality of life (QoL, SF-36) were assessed. The mean (SD) AI was: EN 23.1 (7.6), EA 46.5 (8.8), YN 13.2 (6.6), YA 38.5 (12.1) events/h. AI was higher in the elderly (P = 0.002) and in apnoeics (P = 0.001); however, the increase in AI associated with sleep apnoea was not age dependent (P = 0.73). The influence of sleep apnoea on sleepiness was similar in both age groups. YA but not EA reported reduced physical functioning (P = 0.04), vitality (P = 0.007) and general health (P = 0.04) compared to non-apnoeics. We conclude that (1) the effect of sleep apnoea on arousal is no greater in the elderly compared to the young (2) despite similar levels of sleepiness, elderly apneoics perceive a reduced loss of QoL compared to younger patients.

Ageing does not influence the sleep-related decrease in the hypercapnic ventilatory response

In young people, a sleep-related reduction in the gain of the ventilatory chemoreflex feedback loop occurs; in the elderly, it has been reported that no sleep-related reduction occurs. A relatively high loop gain could contribute to periodic breathing and central sleep apnoea in the elderly. This study tested the hypothesis that ageing is associated with a reduction in the magnitude of the sleep-related decrease in the hypercapnic ventilatory response (HCVR). The HCVR was measured using a steady state method, awake and asleep, in groups (n = 10) of elderly (66-81 yrs) and young (23-35 yrs) nonapnoeics. Upper airway resistance was maintained close to wakefulness levels using continuous positive airway pressure (mean sleep-related increase in resistance: elderly 1.6 +/- 1.2 cmH2O L x s(-1), young 1.2 +/- 0.8 cmH2O x L x s(-1)). The sleep-related decrease in the HCVR was similar in the elderly and young groups (elderly: wake 0.14 +/- 0.06 and sleep 0.06 +/- 0.02 L min(-1) x kPa and young, wake 0.19 +/- 0.07 and sleep 0.10 +/- 0.04 L x min(-1) x kPa). Ageing per se was shown not to change the magnitude of the sleep-related decrease in hypercapnic ventilatory response. The authors speculate that age-related changes in the hypercapnic ventilatory response are unlikely to contribute to the increased prevalence of central sleep apnoea in the elderly.

The high-energy proton fluxes in the SAA observed with REM aboard the MIR orbital station

During two years, from November 1994 to 1996, the particle detector REM measured the highly energetic electron and proton environment at the outside of the MIR orbital station. Using mission averaged data we investigate various aspects of the proton fluxes in the SAA. Comparison with the radiation belt model AP8 reveal important differences.

Proton Irradiation Facility and space radiation monitoring at the Paul Scherrer Institute

The Proton Irradiation Facility (PIF) has been designed and constructed, in cooperation between Paul Scherrer Institute (PSI) and European Space Agency (ESA), for terrestrial proton testing of components and materials for spacecraft. Emphasis has been given to generating realistic proton spectra encountered by space-flights at any potential orbit. The facility, designed in a user-friendly manner, can be readily adapted to the individual requirements of experimenters. It is available for general use serving also in testing of radiation monitors and for proton experiments in different scientific disciplines. The Radiation Environment Monitor REM has been developed for measurements of the spacecraft radiation conditions. Two instruments were launched into space, one into a Geo-stationary Transfer Orbit on board of the STRV-1b satellite and one into a Low Earth Orbit on the Russian MIR station. The next generation of monitors (SREMs--Standard REMs) is currently under development in partnership of ESA, PSI and Contraves-Space. They will operate both as minimum intrusive monitors, which provide radiation housekeeping data and alert the spacecraft when the radiation level crosses allowed limits and as small scientific devices measuring particle spectra and fluxes. Future missions as e.g. INTEGRAL, STRV-1c and PROBA will be equipped with new SREMs.

Repeated exercise paired with "imperceptible" dead space loading does not alter VE of subsequent exercise in humans

We employed an associative learning paradigm to test the hypothesis that exercise hyperpnea in humans arises from learned responses forged by prior experience. Twelve subjects undertook a "conditioning" and a "nonconditioning" session on separate days, with order of performance counterbalanced among subjects. In both sessions, subjects performed repeated bouts of 6 min of treadmill exercise, each separated by 5 min of rest. The only difference between sessions was that all the second-to-penultimate runs of the conditioning session were performed with added dead space in the breathing circuit. Cardiorespiratory responses during the first and last runs (the "control" and "test" runs) were compared for each session. Steady-state exercise end-tidal PCO(2) was significantly lower (P = 0.003) during test than during control runs for both sessions (dropping by 1.8 +/- 2 and 1.4 +/- 3 Torr during conditioning and nonconditioning sessions, respectively). This and all other test-control run differences tended to be greater during the first session performed regardless of session type. Our data provide no support for the hypothesis implicating associative learning processes in the ventilatory response to exercise in humans.

Fatal pentastomiasis in captive African dwarf crocodile hatchlings (Osteolaemus tetraspis)

Six eggs from a captive African dwarf crocodile (Osteolaemus tetraspis) nest were artificially incubated. Two abnormal hatchlings with incomplete absorption of their yolk sacs died within 48 hr of hatching. No parasites were detected grossly or histologically in either hatchling. The remaining four apparently healthy hatchlings died without clinical signs at 3 wk of age, 1 wk after being fed live wild-caught fish and commercially raised goldfish. Necropsy revealed multiple white small wormlike organisms within the lungs, liver, and gastrointestinal tract of all four hatchlings. Histopathologic cross sections suggested that pentastomiasis was the cause of death, and whole parasites were identified as Sebekia mississippiensis. This infection was probably contracted by ingestion of live fish intermediate hosts infected with nymphal parasites. Avoiding the use of infected live fish or untreated fish products can prevent mortality of hatchling crocodilians caused by S. mississippiensis within zoological collections.