Therapeutic hypothermia for acute myocardial infarction and cardiac arrest

This report focuses on cardioprotection and describes the advantages and disadvantages of various methods of inducing therapeutic hypothermia (TH) with regard to neuroprotection and cardioprotection for patients with cardiac arrest and ST-segment elevation myocardial infarction (STEMI). TH is recommended in cardiac arrest guidelines. For patients resuscitated after out-of-hospital cardiac arrest, improvements in survival and neurologic outcomes were observed with relatively slow induction of TH. More rapid induction of TH in patients with cardiac arrest might have a mild to modest incremental impact on neurologic outcomes. TH drastically reduces infarct size in animal models, but achievement of target temperature before reperfusion is essential. Rapid initiation of TH in patients with STEMI is challenging but attainable, and marked infarct size reductions are possible. To induce TH, a variety of devices have recently been developed that require additional study. Of particular interest is transcoronary induction of TH using a catheter or wire lumen, which enables hypothermic reperfusion in the absence of total-body hypothermia. At present, the main methods of inducing and maintaining TH are surface cooling, endovascular heat-exchange catheters, and intravenous infusion of cold fluids. Surface cooling or endovascular catheters may be sufficient for induction of TH in patients resuscitated after out-of-hospital cardiac arrest. For patients with STEMI, intravenous infusion of cold fluids achieves target temperature very rapidly but might worsen left ventricular function. More widespread use of TH would improve survival and quality of life for patients with out-of-hospital cardiac arrest; larger studies with more rapid induction of TH are needed in the STEMI population.     

Growth hormone regimens in Australia: analysis of the first 3 years of treatment for idiopathic growth hormone deficiency and idiopathic short stature

Objective To investigate response to growth hormone (GH) in the first, second and third years of treatment for all idiopathic GH‐deficient (GHD) and idiopathic short stature (ISS) patients in Australia. Context Eligibility for subsidized GH treatment in Australia is determined on auxological criteria for the indication of Short Stature and Slow Growth (SSSG), which includes ISS (SSSG‐ISS). The biochemical GHD (BGHD, peak GH < 10 mU/l) and SSSG indications are treated similarly: starting dose of 4·5 mg/m²/week with provision for incremental dosing. Some ISS patients were specifically diagnosed with familial short stature (SSSG‐FSS). Design Responses for each year of treatment for BGHD, SSSG‐ISS and SSSG‐FSS cohorts were compared in relation to influencing variables and with international benchmarks. The effect of incremental dosing was assessed. Patients Australian BGHD, SSSG‐ISS and SSSG‐FSS patients who had completed 1, 2, or 3 years of treatment and were currently receiving GH. Measurements Growth hormone dose, change in height‐standard deviation score (ΔSDS) and growth velocity (GV). Results First‐year response was 2–3 times greater than that in subsequent years: ΔSDS_{1st year} = 0·92, 0·50 and 0·46 for BGHD, SSSG‐ISS and SSSG‐FSS, respectively. Responses were similar to international reports and inversely related to age at commencement of GH. First‐year GV‐for‐age for BGHD patients was similar to international standards for idiopathic GHD. However, girls had an inferior response to boys when treatment commenced at <6 years of age. First‐year GV‐for‐age for SSSG‐ISS/FSS patients was less than ISS standards. Dose increments attenuated the first‐ to second‐year decline in response to BGHD but marginally improved the responses for SSSG‐ISS/FSS. Conclusions The Australian auxology‐based GH programme produces comparable responses to international programmes. A lower starting dose is offset by the initiation of treatment at younger ages. Incremental dosing does not appear optimal. A first‐year dose of 6·4–6·9 mg/m²/week for GHD and 8·9 mg/m²/week for ISS with early commencement of GH treatment may be most efficacious.     

Ultrathin chitosan–poly(ethylene glycol) hydrogel films for corneal tissue engineering

Due to the high demand for donor corneas and their low supply, autologous corneal endothelial cell (CEC) culture and transplantation for treatment of corneal endothelial dysfunction would be highly desirable. Many studies have shown the possibility of culturing CECs in vitro, but lack potential robust substrates for transplantation into the cornea. In this study, we investigate the properties of novel ultrathin chitosan–poly(ethylene glycol) (PEG) hydrogel films (CPHFs) for corneal tissue engineering applications. Cross-linking of chitosan films with diepoxy-PEG and cystamine was employed to prepare ～50 μm (hydrated) hydrogel films. Through variation of the PEG content (1.5–5.9 wt.%) it was possible to tailor the CPHFs to have tensile strains and ultimate stresses identical to or greater than those of human corneal tissue while retaining similar tensile moduli. Light transmission measurements in the visible spectrum (400–700 nm) revealed that the films were >95% optically transparent, above that of the human cornea (maximum ～90%), whilst in vitro degradation studies with lysozyme revealed that the CPHFs maintained the biodegradable characteristics of chitosan. Cell culture studies demonstrated the ability of the CPHFs to support the attachment and proliferation of sheep CECs. Ex vivo surgical trials on ovine eyes demonstrated that the CPHFs displayed excellent characteristics for physical manipulation and implantation purposes. The ultrathin CPHFs display desirable mechanical, optical and degradation properties whilst allowing attachment and proliferation of ovine CECs, and as such are attractive candidates for the regeneration and transplantation of CECs, as well as other corneal tissue engineering applications.     

Urethral adenocarcinoma associated with intestinal-type metaplasia,case report and literature review

The presence of glandular epithelium in urinary tract biopsies poses a diagnostic challenge. Intestinal metaplasia of the urethra may be seen in many congenital, iatrogenic, and reactive conditions, as well as in association with malignant conditions such as urethral adenocarcinoma. We present a case of a 61 year-old woman presenting with microscopic hematuria. Successive biopsies showed glandular epithelium with focal atypia in close association with inflammation, but no overt malignancy. Only on surgical resection was the associated high grade adenocarcinoma revealed. When intestinal-type mucosa is present within a urinary tract biopsy, associated malignancy may be present only focally. Thorough sampling and consideration of the differential diagnosis is imperative.     

Influence of eugenol on the push-out bond strengths of fiber posts cemented with different types of resin luting agents

This study evaluated the influence of eugenol on the push-out bond strengths of fiber posts cemented with different types of resin luting agents. Seventy-two extracted maxillary single-rooted canine teeth were randomly divided into two groups of 36 teeth. Group 1, the control group, was filled with gutta-percha only (i.e., did not receive eugenol), whereas group 2 was filled with a eugenol-containing sealer. All root canals were filled and each group was divided into three subgroups. The posts in each subgroup were cemented with the following materials: subgroup 1 with a 2-step self-etching adhesive system (Clearfil Liner Bond 2V + Panavia F); subgroup 2 with a 1-step self-etching adhesive (Panavia F); and subgroup 3 with a self-adhesive (Clearfil SA Cement). Dislodgement resistance was measured using a universal testing machine. All data were subjected to ANOVA using a factorial design and Tukey test (α = 0.05). The use of the eugenol-containing sealer significantly reduced the push-out bond strength of the fiber post (P < 0.05). The push-out bond strength of Panavia F was significantly higher than those of the other groups filled with the eugenol-containing sealer (P < 0.05). The Panavia F group was less susceptible to the inhibiting effect of eugenol than were the other evaluated groups when the fiber post was cemented in the canals filled with the eugenol-containing sealer.     

Retrospective review of rectal cancer surgery in northern Alberta

Introduction

Previous studies, including research published more than 10 years ago in Northern Alberta, have demonstrated improved outcomes with increased surgical volume and subspecialisation in the treatment of rectal cancer. We sought to examine contemporary rectal cancer care in the same region to determine whether practice patterns have changed and whether outcomes have improved.

Methods

We reviewed the charts of all patients with rectal adenocarcinoma diagnosed between 1998 and 2003 who had a potentially curative resection. The main outcomes examined were 5-year local recurrence (LR) and disease-specific survival (DSS). Surgeons were classified into 3 groups according to training and volume, and we compared outcome measures among them. We also compared our results to those of the previous study from our region.

Results

We included 433 cases in the study. Subspecialty-trained colorectal surgeons performed 35% of all surgeries in our study compared to 16% in the previous study. The overall 5-year LR rate and DSS in our study were improved compared to the previous study. On multivariate analysis, the only factor associated with increased 5-year LR was presence of obstruction, and the factors associated with decreased 5-year DSS were high-volume noncolorectal surgeons, presence of obstruction and increased stage.

Conclusion

Over the past 10 years, the long-term outcomes of treatment for rectal cancer have improved. We found that surgical subspecialization was associated with improved DSS but not LR. Increased surgical volume was not associated with LR or DSS.