Transverse colon volvulus - a case report and literature review.

SUMMARY: Transverse colon volvulus is a rare diagnosis, with less than 100 cases reported up to 2019. The condition is complicated by the absence of characteristic radiological findings and is typically diagnosed intraoperatively. It is a surgical emergency as the condition can lead to bowel necrosis and is associated with a mortality rate of up to 33%. Bowel resection is the treatment of choice, and if a megacolon is present a subtotal colectomy is recommended. Due to the rarity of transverse colon volvulus, limited data is available on the long-term outcome of patients.

Transverse colon volvulus - a case report and literature review.

SUMMARY: Transverse colon volvulus is a rare diagnosis, with less than 100 cases reported up to 2019. The condition is complicated by the absence of characteristic radiological findings and is typically diagnosed intraoperatively. It is a surgical emergency as the condition can lead to bowel necrosis and is associated with a mortality rate of up to 33%. Bowel resection is the treatment of choice, and if a megacolon is present a subtotal colectomy is recommended. Due to the rarity of transverse colon volvulus, limited data is available on the long-term outcome of patients.

Editorial: citation malpractice.

At Proceedings of the Royal Society A, something we are always concerned and vigilant about is publication malpractice. This editorial examines the background to some small changes to our reviewer forms that will help us in identifying patterns of worrying behaviour. The importance of this in the context of the relationship of science to policy-making and the public perception of science is stressed.

Coronal mass ejections are not coherent magnetohydrodynamic structures.

Coronal mass ejections (CMEs) are episodic eruptions of solar plasma and magnetic flux that travel out through the solar system, driving extreme space weather. Interpretation of CME observations and their interaction with the solar wind typically assumes CMEs are coherent, almost solid-like objects. We show that supersonic radial propagation of CMEs away from the Sun results in geometric expansion of CME plasma parcels at a speed faster than the local wave speed. Thus information cannot propagate across the CME. Comparing our results with observed properties of over 400 CMEs, we show that CMEs cease to be coherent magnetohydrodynamic structures within 0.3 AU of the Sun. This suggests Earth-directed CMEs are less like billiard balls and more like dust clouds, with apparent coherence only due to similar initial conditions and quasi homogeneity of the medium through which they travel. The incoherence of CMEs suggests interpretation of CME observations requires accurate reconstruction of the ambient solar wind with which they interact, and that simple assumptions about the shape of the CMEs are likely to be invalid when significant spatial/temporal gradients in ambient solar wind conditions are present.

Global solar wind variations over the last four centuries.

The most recent "grand minimum" of solar activity, the Maunder minimum (MM, 1650-1710), is of great interest both for understanding the solar dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the solar corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global solar wind variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and solar wind speed, and up to a factor 4 increase in solar wind Mach number. Thus solar wind energy input into the Earth's magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total solar irradiance estimates during grand minima.

Private land manager capacity to conserve threatened communities under climate change.

Major global changes in vegetation community distributions and ecosystem processes are expected as a result of climate change. In agricultural regions with a predominance of private land, biodiversity outcomes will depend on the adaptive capacity of individual land managers, as well as their willingness to engage with conservation programs and actions. Understanding adaptive capacity of landholders is critical for assessing future prospects for biodiversity conservation in privately owned agricultural landscapes globally, given projected climate change. This paper is the first to develop and apply a set of statistical methods (correlation and bionomial regression analyses) for combining social data on land manager adaptive capacity and factors associated with conservation program participation with biophysical data describing the current and projected-future distribution of climate suitable for vegetation communities. We apply these methods to the Tasmanian Midlands region of Tasmania, Australia and discuss the implications of the modelled results on conservation program strategy design in other contexts. We find that the integrated results can be used by environmental management organisations to design community engagement programs, and to tailor their messages to land managers with different capacity types and information behaviours. We encourage environmental agencies to target high capacity land managers by diffusing climate change and grassland management information through well respected conservation NGOs and farm system groups, and engage low capacity land managers via formalized mentoring programs.

Possible impacts of a future grand solar minimum on climate: Stratospheric and global circulation changes.

A future decline in solar activity would not offset projected global warmingA future decline in solar activity could have larger regional effects in winterTop-down mechanism contributes to Northern Hemisphere regional response.

Extended magnetic reconnection across the dayside magnetopause.

The extent of where magnetic reconnection (MR), the dominant process responsible for energy and plasma transport into the magnetosphere, operates across Earth's dayside magnetopause has previously been only indirectly shown by observations. We report the first direct evidence of X-line structure resulting from the operation of MR at each of two widely separated locations along the tilted, subsolar line of maximum current on Earth's magnetopause, confirming the operation of MR at two or more sites across the extended region where MR is expected to occur. The evidence results from in-situ observations of the associated ion and electron plasma distributions, present within each magnetic X-line structure, taken by two spacecraft passing through the active MR regions simultaneously.

Prophylactic versus preemptive oral valganciclovir for the management of cytomegalovirus infection in adult renal transplant recipients.

Prophylaxis reduces cytomegalovirus (CMV) disease, but is associated with increased costs and risks for side effects, viral resistance and late onset CMV disease. Preemptive therapy avoids drug costs but requires frequent monitoring and may not prevent complications of asymptomatic CMV replication. Kidney transplant recipients at risk for CMV (D+/R-, D+/R+, D-/R+) were randomized to prophylaxis (valganciclovir 900 mg q.d. for 100 days, n=49) or preemptive therapy (900 mg b.i.d. for 21 days, n=49) for CMV DNAemia (CMV DNA level>2000 copies/mL in >or=1 whole blood specimens by quantitative PCR) assessed weekly for 16 weeks and at 5, 6, 9 and 12 months. More patients in the preemptive group, 29 (59%) than in the prophylaxis group, 14 (29%) developed CMV DNAemia, p=0.004. Late onset of CMV DNAemia (>100 days after transplant) occurred in 11 (24%) randomized to prophylaxis, and none randomized to preemptive therapy. Symptomatic infection occurred in five patients, four (3 D+/R- and 1 D+/R+) in the prophylactic group and one (D+/R-) in the preemptive group. Peak CMV levels were highest in the D+/R- patients. Both strategies were effective in preventing symptomatic CMV. Overall costs were similar and insensitive to wide fluctuations in costs of either monitoring or drug.

Cytomegalovirus colitis--an unusual cause for diarrhoea in an elderly woman.

BACKGROUND: Clinically apparent cytomegalovirus (CMV) disease is uncommon in the immunocompetent host, despite the high seroprevalence rate of CMV in the general population. CASE REPORT: Here, we report the case of CMV colitis in an immunocompetent elderly woman who developed a large pulmonary embolism during her illness. DISCUSSION: The diagnosis of CMV colitis is made on histological examination of biopsy specimens obtained at sigmoidoscopy or colonoscopy. Extensive CMV disease can be accompanied by vascular thrombosis.

The moral status of the human embryo.

I first delineate the concept of personhood--that cluster of capacities that distinguish us from non-human animals--and then argue that mere potentiality for personhood does not by itself confer upon the embryo a serious right to life. What is required, in addition, is the presence of brain life, which almost certainly does not develop until the second trimester.

Structure-activity investigation of the inhibition of 3-hydroxypyridin-4-ones on mammalian tyrosine hydroxylase.

3-Hydroxypyridin-4-ones are currently one of the main candidates for the development of orally active iron chelators. Small bidentate ligands tend to inhibit iron-containing metalloenzymes and therefore can cause undesirable side effects. A range of 3-hydroxypyridin-4-ones with different R2 substituents was selected for the investigation of the structure-activity relationship between the chemical nature of the ligand and the inhibition of mammalian tyrosine hydroxylase. Results indicated that lipophilicity was the dominant factor in controlling the ability of this class of chelator to inhibit mammalian tyrosine hydroxylase. Ligands with hydrophilic R2 substituents tended to be weak inhibitors. No significant correlation was found in this study between iron-binding affinity, extended R2 chain length, and enzyme inhibitory activity. In contrast, both the LogP values of the entire molecule and of the R2 segment correlated well with inhibitory activity.

Radiolabeled leucocyte imaging in diffuse granulomatous involvement of the meninges in Wegener's granulomatosis: scintigraphic findings and their role in monitoring treatment response to specific immunotherapy (humanized monoclonal antilymphocyte antibodies).

BACKGROUND AND PURPOSE: Diffuse involvement of the meninges by remote granulomas in Wegener's granulomatosis is rare. This study reports the radiolabeled leucocyte imaging findings in five such patients. The diagnosis was made by MR imaging in five patients and confirmed in four by findings at meningeal biopsy. The potential role of serial radiolabeled leucocyte examinations in assessing treatment response is discussed. METHODS: Three of the five patients underwent whole-body planar 111In-labeled leucocyte imaging. Two of these patients had serial imaging and one had, in addition, a 99mTc-HMPAO-labeled leucocyte single-photon emission CT brain examination. Two of the five patients had whole-body planar 99mTc-HMPAO-labeled leucocyte imaging. Of these, one patient had serial imaging. The radiolabeled leucocyte imaging findings were correlated with MR findings and with the patients' clinical course. RESULTS: In four patients there was a midline linear area of increased tracer uptake in the brain, and in one of these, tracer uptake also extended laterally over the brain convexity. In two patients linear tracer uptake extended in an inferolateral direction from the midline. These abnormalities correlated with meningeal thickening in the falx, over the brain convexity, and in the tentorium cerebelli on MR images. Serial imaging in three patients revealed a reduction or disappearance in tracer uptake after treatment with anti-CD52, which correlated with clinical improvement. CONCLUSION: In patients with Wegener's granulomatosis, abnormal uptake corresponding to meningeal thickening can be seen on planar radiolabeled leucocyte images. Leucocyte imaging may be useful for monitoring treatment response.

Wegener granulomatosis: MR imaging findings in brain and meninges.

PURPOSE: To determine the spectrum of intracranial magnetic resonance (MR) imaging appearances of Wegener granulomatosis. MATERIALS AND METHODS: MR imaging studies in 19 patients with Wegener granulomatosis and possible central nervous system involvement were reviewed by two neuroradiologists. Intermediate-weighted and T2-weighted fast spin-echo MR images of the brain had been acquired in all patients, and spin-echo T1-weighted nonenhanced and gadolinium-enhanced images had been acquired in 18 patients. RESULTS: MR imaging findings included diffuse linear dural thickening and enhancement (n = 6); focal dural thickening and enhancement contiguous with orbital, nasal, or paranasal disease (n = 5); infarcts (n = 4); nonspecific white matter areas of high signal intensity on intermediate-weighted and T2-weighted images (n = 10); enlarged pituitary gland with infundibular thickening and enhancement (n = 2); a discrete cerebellar lesion that was probably granulomatous in origin (n = 1); and cerebral (n = 8) and cerebellar atrophy (n = 2). CONCLUSION: MR imaging demonstrated the wide spectrum of findings of central nervous system involvement in patients with Wegener granulomatosis and was particularly useful for the evaluation of direct intracranial spread from orbital, nasal, or paranasal disease.

Cutaneous vasculitis in a defined population--clinical and epidemiological associations.

OBJECTIVE: To examine the value of the American College of Rheumatology (ACR) 1990 criteria for Henoch-Schönlein purpura (HSP) and hypersensitivity vasculitis (HSV) and the Chapel Hill Consensus Conference (CHCC) definition of cutaneous leukocytoclastic angiitis (CLA) in the classification of cutaneous vasculitis and to estimate the annual incidence of biopsy proven cutaneous vasculitis in a well defined population. METHODS: ACR criteria for HSP and HSV and the CHCC definition for CLA and HSP were applied to an unselected cohort of 84 patients with biopsy proven cutaneous vasculitis attending a single district hospital in the United Kingdom between January 1990 and December 1994. RESULTS: Thirty-seven patients fulfilled ACR criteria for HSV, of whom 27 also fulfilled the ACR criteria for HSP. Thirty-two patients met the CHCC definition for CLA and 7 the CHCC definition for HSP. The overall annual incidence of cutaneous vasculitis was 38.6/million (95% CI 30.6-48.1), and for CLA 15.4/million (95% CI 10.6-21.8). CONCLUSION: The ACR 1990 criteria for HSP and HSV overlap; the CHCC definitions for CLA and HSP provide clearer distinction. Cutaneous vasculitis is as common as systemic vasculitis.

Primary heart angiosarcoma detected by computed tomography and magnetic resonance imaging.

We report a case of primary heart angiosarcoma and its appearance on plain and post-contrast computed tomography and magnetic resonance imaging in 21-year-old woman. The tumour involved the right atrium, expanded superiorly among the superior vena cava, ascending aorta and innominate vein, and infiltrated the pericardium. The tumour was disseminated into lungs, liver and bones at the time of its clinical presentation.

Cycle-to-cycle variability attributed to the primary respiratory mechanism.

Wave forms attributed to the primary respiratory mechanism (PRM), as published by Viola Frymann, DO, in JAOA June 1971, were analyzed for an undescribed parameter, cycle-to-cycle variability. Tracings from this paper were independently measured by two physicians focusing on the duration of each cycle. Consistency of the measurements and interexaminer agreement were shown. The duration of individual cycles demonstrated significant cycle-to-cycle variability ranging from 0.6 second up to 6.3 seconds. The reason for variability as well as its clinical significance is unknown. The minute rate of each tracing ranged from 6.5 to 13.8 cycles per minute (0.108 to 0.230 Hz [corrected]), mean 10.8 +/- 2.3 (0.180 +/- 0.038 Hz [corrected]). (Different minute rates attributed to the PRM have been reported in other studies.) Although variability is an innate characteristic of biologic cycles, this phenomenon has not been previously reported for the PRM. The authors suggest that this variability has likely confounded previous interexaminer reliability studies and should be considered in any future studies of this type. Determination of causes of this variability present timely and fruitful avenues of research.