The medicalization of sunlight in the early twentieth century

This paper traces the emergence of the therapeutic use of sunlight in medicine during the first half of the twentieth century. This was a period of considerable flux in medicine with various strands of practice and theory competing. Drawing on two case studies of sunlight therapy, both artificial (actinotherapy) and natural (heliotherapy), in the treatment of rickets and tuberculosis this paper will explore how medicine was constituted within these regimes. The paper will argue that therapeutic and clinical applications of sunlight helped establish an association between sunlight and health but also defined a particular and specific performance of medicine.

A cleaner river: long term use of semipermeable membrane devices demonstrate that concentrations of selected organochlorines and PAHs in the Brisbane River estuary, Queensland have reduced substantially over the past decade

We first used semipermeable membrane devices as samplers to evaluate concentrations of organochlorines and PAHs in the Brisbane River in 1998. Here we revisit this work and repeat the study a decade later in the same season (summer), also taking account of results from a similar study involving PAHs in the summer of 2001-2002. The accumulation of organochlorines and most PAHs in the samplers in the recent assessment was substantially less than in the 1998 deployment, suggesting that the ambient concentrations of these chemicals have decreased considerably over the last decade. In all cases there was high reproducibility of the mass of chemicals accumulated in the sampler. We used performance reference compounds in the later deployment, and assuming that the kinetics were similar in both deployment periods, we estimate that the concentration of dieldrin, the organochlorine found at highest concentrations, decreased from approximately 3.9 ng/L to about 1.4 ng/L. The decrease of most other analytes of interest including DDE and DDD was greater, potentially indicating that dieldrin is still entering the Brisbane River through run-off from urban areas where it was used widely for treatment of termites until 1995. DDT use in Australia ceased in the mid 1980s.

Ca²+-dependent phosphorylation of RyR2 can uncouple channel gating from direct cytosolic Ca²+ regulation

Phosphorylation of the cardiac ryanodine receptor (RyR2) is thought to be important not only for normal cardiac excitation-contraction coupling but also in exacerbating abnormalities in Ca²+ homeostasis in heart failure. Linking phosphorylation to specific changes in the single-channel function of RyR2 has proved very difficult, yielding much controversy within the field. We therefore investigated the mechanistic changes that take place at the single-channel level after phosphorylating RyR2 and, in particular, the idea that PKA-dependent phosphorylation increases RyR2 sensitivity to cytosolic Ca²+. We show that hyperphosphorylation by exogenous PKA increases open probability (P(o)) but, crucially, RyR2 becomes uncoupled from the influence of cytosolic Ca²+; lowering [Ca²+] to subactivating levels no longer closes the channels. Phosphatase (PP1) treatment reverses these gating changes, returning the channels to a Ca²+-sensitive mode of gating. We additionally found that cytosolic incubation with Mg²+/ATP in the absence of exogenously added kinase could phosphorylate RyR2 in approximately 50% of channels, thereby indicating that an endogenous kinase incorporates into the bilayer together with RyR2. Channels activated by the endogenous kinase exhibited identical changes in gating behavior to those activated by exogenous PKA, including uncoupling from the influence of cytosolic Ca²+. We show that the endogenous kinase is both Ca²+-dependent and sensitive to inhibitors of PKC. Moreover, the Ca²+-dependent, endogenous kinase-induced changes in RyR2 gating do not appear to be related to phosphorylation of serine-2809. Further work is required to investigate the identity and physiological role of this Ca²+-dependent endogenous kinase that can uncouple RyR2 gating from direct cytosolic Ca²+ regulation.

Molecular cytogenetic analysis of cervical squamous cell carcinoma cells demonstrates discordant levels of numerical and structural chromosomal instability and identifies 'selected' chromosome rearrangements

The processes underlying the karyotype complexity and heterogeneity characteristic of cervical squamous cell carcinoma (SCC) cells are not well understood, nor is it known which chromosome abnormalities provide a selective advantage. We used molecular cytogenetics to quantify for the first time the prevalence of all chromosomal abnormalities detectable in 8 cervical SCC cell lines. Of 225 rearrangements identified, 118 occurred frequently (> or =70% metaphases) in one or more lines, indicating selection. Most of these selected rearrangements (107; 48% of the total) were included in published lists of abnormalities detected in independent cell stocks (although their significance was not previously recognised), indicating that they arose early in the establishment of the lines and were therefore most likely to have been present in the original tumours. The 8 cell lines showed 4.7- and 11.0-fold variation in levels of numerical and structural chromosomal instability (N-CIN and S-CIN) respectively, as determined by quantifying non-clonal abnormalities. We observed discordance between N-CIN and S-CIN (p = 0.148), with modal chromosome number showing a strong association with N-CIN (p = 0.007) but not with S-CIN (p = 0.602). These data imply that different mechanisms underlie N-CIN and S-CIN in cervical SCC. Despite ongoing S-CIN, newly arisen in vitro rearrangements were infrequently selected, supporting the view that selection is an important determinant of somatic evolution in malignancy. There was a positive association between numbers of non-clonal and clonal rearrangements (p = 0.002 for non-clonal vs. selected rearrangements), suggesting that factors affecting S-CIN determine the total numbers of rearrangements present in established cervical SCC cells.

Recumbent Exercise Bicycle for Low-Impact Rehabilitation of Obese Individuals

It is often difficult for persons who are extremely overweight to find exercise systems that are accessible and safe to use. Seating is required to handle heavier loads of up to 500 lbs. and provide safe access to the exercise unit. Additionally, the exercise should not cause additional pain or possible damage if the person needs to suddenly stop. A multidisciplinary team of undergraduate engineers participated in a training course to interview a non-technical customer to determine design requirements and then underwent a rigorous design process to implement the best solution. Mechanical analysis was performed to determine the best solution for the concept, materials, and resistance. An exercise machine with a rotating chair was selected as the best solution. The chair rotates 90 degrees so that the user can sit down without having to step onto the machine. Once the user sits, the chair can then rotate 90 degrees until the chair is in the exercise position; in either position the chair locks into position for stability. This particular concept uses a bicyle exercise. This exercise minimizes impact on the knees, which is a safety issue for patients with knee problems. A sitting position for this exercise eliminates the stability issue raised with a standing exercise, where there is worry of falling. This exercise is beneficial for cardiovascular exercise. Resistance is implemented using a magnet. Fluid resistance and fly-wheel resistance would create too much momentum which was not desired by the customer. Electrical analysis was performed to determine the best method to sense heart rate, speed, and computer interface. Wired handles were selected to monitor the heart rate. These are hand held and are much easier to use than a chest strap. An optical sensor was used to sense speed. It was placed near the center of the wheel and rotations were indicated by a tab to break the connection in the sensor. This method was selected over a Hall effect sensor because it is a much simpler sensing method that does not require an addition magnetic component that is not too accurate a low speeds. The computer interface was a Motorola HC12s since it had the necessary I/O interfaces and was low cost. A custom interface was created with seven segment displays to show the heart rate and time of exercise. The system was then developed, tested, and delivered to the customer for use. This project was supported by Grant No. 0607883 from the National Science Foundation.

The management of trauma victims in England and Wales: a study by the National Confidential Enquiry into Patient Outcome and Death

OBJECTIVE

Trauma is the leading cause of death in the first four decades of life in western countries. A national prospective study was conducted in the UK to examine the process and quality of care of severely injured patients. We present a previously unpublished analysis of the severity of injury, place of treatment, quality of care and survival amongst patients with thoracic injuries.

METHODS

All UK hospitals with an emergency department were asked to provide prespecified clinical and process data on all patients presenting with significant injuries between 1st February and 30th April 2006. All data were stripped of patient, clinician and institutional identifiers before review by expert advisors.

RESULTS

Data adequate for analysis were obtained on 1735 of 2203 injured patients reported. An injury severity score (ISS) > or = 16, the threshold for severe injury, was derived from case records of 795 patients, who comprise the study denominator. Of these, 387 (49%) had a thoracic injury, usually as part of polytrauma. The mortality rate was 8% (of 13) 9% (of 23) 10% (of 175) 14% (of 136) 22% (of 37) and 100% (of 3) for the six ascending grades of severity for the thoracic component of the ISS score. One hundred and seventy-six of the 795 patients (22%) had a thoracic injury sufficient for them to be classified as severely injured regardless of any other injuries. The quality of care as assessed by expert advisors showed an apparent association with overall trauma volume of the 142 treating hospitals. For patients with thoracic injuries where the specialty of the team in charge could be identified (n = 284/387) trauma and orthopaedics (T and O) cared for 36%, critical medicine 22%, general surgery 19%, neurosurgery 8% and only 5% were in the care of thoracic surgeons. One or more chest drains were inserted in 203/795 (26%) of patients, few of them by thoracic surgeons.

CONCLUSIONS

Given that polytrauma patients rarely come under the care of thoracic surgeons and yet frequently have severe thoracic injuries there is a clear need for T and O surgeons and generalists to have a good grounding in thoracic procedures.

Anterior cingulate cortex abnormalities associated with a first psychotic episode in bipolar disorder

BACKGROUND

The anterior cingulate cortex is frequently implicated in the pathophysiology of bipolar disorder, but magnetic resonance imaging (MRI) studies have reported variable findings owing to a reliance on patient samples with chronic illness and to limited appreciation of the region's heterogeneity.

AIMS

To characterise anterior cingulate cortex abnormalities in patients with bipolar disorder experiencing their first episode of psychosis while accounting for regional anatomical variability.

METHOD

Grey matter volume, surface area and cortical thickness were measured in six anterior cingulate cortex subregions per hemisphere using MRI scans acquired from 26 patients with bipolar I disorder experiencing first-episode psychosis and 26 healthy controls matched for age, gender and regional morphological variability.

RESULTS

Relative to controls, male patients displayed increased thickness in the right subcallosal limbic anterior cingulate cortex. No significant differences were identified in females for grey matter volume or surface area measures. The findings were not attributable to medication effects.

CONCLUSIONS

These data suggest that first-episode psychosis in bipolar disorder is associated with a gender-specific, right-lateralised thickness increase in anterior cingulate cortex subregions known to play a role in regulating physiological stress responses.

Persistence of improvement in insulin sensitivity following a dietary weight loss programme

AIM

Short-term dietary weight loss can improve insulin resistance but long-term studies are lacking. We sought to quantify the degree to which maintenance of weight loss after a short-term dietary intervention was associated with persistent metabolic benefits.

METHODS

Fifty-seven insulin-resistant obese subjects had insulin-mediated glucose disposal quantified through the steady-state plasma glucose (SSPG) test, and associated metabolic risk markers quantified at baseline, after a 16-week dietary weight loss intervention, and in 25 subjects, at follow-up of 28.8 +/- 13 months. Changes in metabolic variables over time were analysed and correlation with weight loss ascertained. Those with greatest vs. least long-term SSPG response (responders vs. non-responders) were compared. Multivariate analysis was performed for predictors of persistent SSPG response.

RESULTS

At follow-up, the 25 subjects who returned for metabolic testing had, on average, maintained their weight loss. Insulin-mediated glucose disposal remained significantly improved vs. baseline, as did plasma triglyceride and HDL cholesterol (HDL-C) concentrations, and improvement correlated with total amount of weight lost. Comparison of SSPG responders to non-responders showed no difference in amount of weight lost and SSPG change during the 16-week dietary intervention; however, SSPG non-responders regained 2.6% of weight lost, whereas responders lost an additional 1.5% at follow-up (p < 0.05 vs. non-responders). Non-responders had baseline characteristics consistent with more severe insulin resistance, including higher fasting plasma glucose (p = 0.03). Long-term SSPG change was independently predicted by both total weight loss (p = 0.005) and baseline fasting plasma glucose (p = 0.007).

CONCLUSIONS

Improvement in insulin sensitivity is maintained for 2-3 years following dietary weight loss if weight is not regained. Triglyceride and HDL-C concentrations also remain improved over time, consistent with improvement in insulin sensitivity. Fasting glucose and weight regain predict less long-term response in insulin sensitivity. These results highlight the potential long-term benefits of weight loss and importance of preventing weight regain among high-risk individuals.