Reflections on nephritis

A brief resume of the pathological aspect of Bright's disease is given. The interpretation usually put on the pathological findings is that the various types of Bright's disease represent different stages of one continuous process which is initiated by the primary glomerular lesions in the first or acute stage. hence the use of the terms first, second and third stage nephritis. The continuous process is usually regarded as a progressive degeneration of the renal elements brought about by the obstruction to blood flow through the glomeruli. The clinical course of Bright's disease is briefly reviewed. It is pointed out that only a minority of cases pass through the three stages or types. Subacute or "second stage" nephritis is often encountered apparently arising independently. The explanation of this phenomenon by assuming a preexisting "subclinical" acute nephritis is discussed. The functioning power of the kidneys in the three stages or types of Bright's disease is described. It is pointed out that acute glomerulo- nephritis and chronic glomerulo- nephritis are associated with impairment of excretion of nitrogenous end products by the kidneys and that the blood pressure is raised, while in subacute glomerulo- nephritis excretion of nitrogenous end products is adequate, and the blood pressure is normal. An investigation is described which attempts to establish the presence or absence of a "subclinical" acute glomerulo- nephritis. The limitations of the investigation are pointed out. No evidence was found to favour the presence of such an entity. The view that Bright's disease is a condition which inevitably progresses from the acute stage through the subacute to the chronic stage, or ends in cure after the acute or subacute stage, is criticised. It is pointed out that the fact that renal function improves when a case passes from the acute to the subacute type is not in keeping with the view that the change is due to a further progression of damage to the nephrons initiated in the acute phase. That the tubular degeneration which is so marked in subacute glomerulo-nephritis, is due to vascular obstruction of the glomeruli is shown to be false. It is demonstrated that the tubules have their own direct blood supply which is quite adequate even although glomerular circulation is abolished entirely. If the acute stage initiates a chain of events which leads inevitably to a small granular kidney with failing function, why do not all cases show this progression? A point is made of the fact that the glomerulitis seen in Bright's disease is not pathognomonic for that condition. It is a non -specific response which can result from a variety of stimuli or toxins of varying intensity. Such glomerular changes are seen in focal embolic nephritis, syphilitic nephritis, in diphtheria and typhoid etc. That tubular degeneration can occur with little or nothing in the way of coincident glomerular changes is evidenced by such conditions as lipoid nephrosis, nephroses due to chemical irritants etc. An alternative view is suggested. The micro - pathology of the various types of Bright's disease are regarded as reactions which vary in tempo in accordance with the intensity of the irritant, so that acute, subacute, and to some extent chronic, reactions take place. The similarity between the process and that which occurs in acute, subacute yellow atrophy, and healed yellow atrophy of the liver is mentioned. In this way cases of acute and subacute glomerulo-nephritis can arise de novo. It is suggested that the response evoked in the kidney (the type of nephritis) depends on the intensity of the circulating toxin. The toxin may be the same for all types of Bright's disease or may differ. Chronic focal sepsis would appear to play a part in the aetiology of some cases of subacute glomerulo-nephritis. The method by which the toxin intensity may vary is discussed. Partial breakdown of immunity mechanism is suggested as a cause, and is linked with the low blood complement and proteins observed in some cases of nephritis. The possibility of aglomerular tubular function in sub -acute and chronic glomerulo- nephritis is mentioned. This is not regarded as being the sole mechanism by which the kidneys function but may well play an important part. From these reflections it is felt that the "accepted view" rests on very slender evidence, namely, that some cases do progress through the various stages, and that the glomerular changes can be traced through these stages. As we have seen there is nothing pathognomonic about "glomerulitis". It can result from a variety of causes. The known facts would appear to be explained by the alternative view more satisfactorily. The evidence suggests that subacute nephritis is due to a toxin of less intensity than is encountered in acute nephritis, and as such may arise independently or follow an acute attack. Chronic glomerulo- nephritis is probably a stage of healing with perhaps some mild irritant action superimposed, and is therefore a sequence of repeated attacks of acute glomerulonephritis, or of subacute glomerulo-nephritis. The necessity for more numerous and extended investigations into the question of "subclinical nephritis" is appreciated

SBMS: A Visual Exploration of Liberian Identity

This article explores the use of visuals by missionaries and social scientists to communicate their encounters in sub-Saharan Africa. It offers an alternative perspective by incorporating the Sight Beyond My Sight (SBMS) visual research methodology created by Gabriel Tait. SBMS is a participant research method that employs photography as a way to understand culture and identity. The implications of this body of work, and the method it provides, presents a much-needed contextual lens for missionaries, visual ethnographers, and general persons who are interested in communicating their contexts in partnership with the cultures they are encountering and impacting. The implication of this work is a more accurate representation of the identities of the people they are working alongside

Gamma-ray lines and One-Loop Continuum from s-channel Dark Matter Annihilations

The era of indirect detection searches for dark matter has begun, with the sensitivities of gamma-ray detectors now approaching the parameter space relevant for weakly interacting massive particles. In particular, gamma ray lines would be smoking gun signatures of dark matter annihilation, although they are typically suppressed compared to the continuum. In this paper, we pay particular attention to the 1-loop continuum generated together with the gamma-ray lines and investigate under which conditions a dark matter model can naturally lead to a line signal that is relatively enhanced. We study generic classes of models in which DM is a fermion that annihilates through an s-channel mediator which is either a vector or scalar and identify the coupling and mass conditions under which large line signals occur. We focus on the "forbidden channel mechanism" advocated a few years ago in the "Higgs in space" scenario for which tree level annihilation is kinematically forbidden today. Detailed calculations of all 1-loop annihilation channels are provided. We single out very simple models with a large line over continuum ratio and present general predictions for a large range of WIMP masses that are relevant not only for Fermi and Hess II but also for the next generation of telescopes such as CTA and Gamma-400. Constraints from the relic abundance, direct detection and collider bounds are also discussed.Comment: 32 pages, 13 figures; v2: minor clarifications, summary paragraph added; v3: matches published version, minor clarifications, results unchange

The WIMP Forest: Indirect Detection of a Chiral Square

The spectrum of photons arising from WIMP annihilation carries a detailed imprint of the structure of the dark sector. In particular, loop-level annihilations into a photon and another boson can in principle lead to a series of lines (a WIMP forest) at energies up to the WIMP mass. A specific model which illustrates this feature nicely is a theory of two universal extra dimensions compactified on a chiral square. Aside from the continuum emission, which is a generic prediction of most dark matter candidates, we find a "forest" of prominent annihilation lines that, after convolution with the angular resolution of current experiments, leads to a distinctive (2-bump plus continuum) spectrum, which may be visible in the near future with the Fermi Gamma-Ray Space Telescope (formerly known as GLAST).Comment: 11 pages, 4 figure