Intestinal Spirochetosis and Acquired Immunodeficiency Syndrome: Ultrastructural Studies of Two Cases

Two cases of intestinal spirochetosis (IS) with acquired immunodeficiency syndrome are reported. In case 1, a 48-year-old homosexual black man presented with a 1-month history of alternating watery diarrhea and constipation, which dissipated following the removal of two colonic hyperplastic polyps containing IS. In case 2, a 26-year-old homosexual black man presented with a 3-month history of persistent bloody diarrhea and was found to have chronic shigellosis and IS. Pathologic findings of IS were similar in both cases. Basophilic fringes typical of IS covered the surfacing colonic epithelium and consisted of dense growths of spirochetes adherent to and oriented perpendicular to the plasma membranes of the surfacing epithelium. The spirochetes measured 3 to 5 μm in length and 0.2 (im in width, contained four to eight axial fibrils, and closely resembled Brachyspira aalborgi ultrastructurally. These cases are notable because the histopathologic changes of IS were more extensive than generally described. There was involvement of both the right colon and rectum by IS in case 2, and in both cases there was extension of the IS down into the crypts of Lieberkiihn, spirochetal invasion of the colonic mucosa, and a conspicuous inflammatory response by macrophages in the underlying lamina propria.     

Selenium improves cardiac function by attenuating the activation of NF-kappaB due to ischemia-reperfusion injury

Although selenium, an essential trace element and a component of glutathione peroxidase, is known to protect the heart from ischemia-reperfusion (I/R)-induced injury, the mechanisms of this protection are not fully understood. For this purpose, isolated rat hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion; sodium selenite (25-1,000 nM) was added in the perfusion medium 10 min prior to ischemia, as well as during reperfusion. Selenium caused a dose-dependent improvement in cardiac performance and attenuated the decrease in the ratio of reduced glutathione to oxidized glutathione, as well as the increased level of malondialdehyde in I/R heart. Elevated ratios of nuclear factor-kappaB (NF-kappaB) in particulate and cytosolic fraction and of phosphorylated NF-kappaB and total NF-kappaB in I/R hearts were reduced by selenium. Cardiac dysfunction in hearts perfused with xanthine plus xanthine oxidase mixture, as well as hydrogen peroxide, or subjected to Ca2+ paradox was also attenuated by selenium. These data suggest that selenium protects the heart against I/R injury due to its action on the redox state and deactivation of NF-kappaB in I/R hearts.     

Evaluation of germ tube test in various media

One of the most valuable tests for the rapid presumptive identification of Candida albicans is germ tube production. Previously researchers have concluded superior results with serum in germ tube test. However, handling of pooled human serum has danger of acquisition of hepatitis and HIV infections. Therefore, in the present study we compared various media--pooled human serum, sterile horse serum, peptone water and tryptic soy broth. It was observed that human serum remains to be the best with 100% positivity for identification of C. albicans followed by horse serum (76.3%), peptone water (61.8%) and tryptic soy broth (61.8%).     

Classes of neurons in relation to the laminar organization of the lateral geniculate nucleus in the tree shrew, Tupaia belangeri

We used the rapid Golgi and horseradish peroxidase (HRP) techniques to study the dendritic spread of relay neurons in functionally distinct laminae of the tree shrew dorsal lateral geniculate nucleus (LGNd). On the basis of their dendritic spread in relation to laminar and interlaminar zones, we describe three classes of relay neurons. Unilaminar neurons with multipolar radiate, bitufted, and intermediate types of dendrites. Dendrites of these neurons are confined to one lamina only, but also can have some of their segments in adjacent interlaminar zones. Multilaminar neurons with multipolar radiate, bitufted, and intermediate types of dendrites. Independent of the site of their cell bodies in a laminar or interlaminar zone, these neurons spread their dendrites over two or more laminae. Interlaminar neurons whose cell bodies and dendrites are confined to a single interlaminar zone. Unilaminar neurons are found in all the laminae. In the medial three laminae, they are more of the radiate type, whereas in laminae 4 and 5 their dendrites tend to be more of a tufted nature. Lamina 6 shows a preponderance of the elongated bitufted type. Multilaminar neurons, although less common as compared to the unilaminar, are also observed in all the laminae. Some neurons have their dendrites confined to an interlaminar zone. By retrograde transport of HRP injected into the visual cortex, we have shown that these neurons are, in fact, relay neurons. In addition to relay neurons, there are small interneurons with "axoniform" dendrites and an unmyelinated axon whose arborization is confined within the limits of the neuron's dendritic spread. Neurons of this type are not labeled with HRP injected into the visual cortex. We conclude that although each lamina is functionally specialized by input from ipsilateral or contralateral retina and by segregation of neurons responding to on or off stimuli, some multilaminar neurons can be found in each lamina. Thus, laminar as well as interlaminar zones contain a class of neurons that could provide a cross-talk between the functionally specialized laminae. Most relay neurons in all the laminae, however, confine their dendrites to their home lamina. Thus, the dendritic architecture of relay neurons allows for processing of information both within channels and between channels.     

Winter admissions. All wrapped up?

Most initiatives to cope with increased winter workloads come from hospitals. The potential for co-operative efforts between hospitals and general practice is largely unexplored. One general practice, a total purchasing pilot site, plans to minimise the demand for emergency admissions by identifying patients at risk and having a nurse visit them in autumn to check their health. The practice estimates the project will be self-financing if it saves 12 admissions.     

Nocturnal plasma thyrotropin variations are related to slow-wave sleep

SUMMARY  The thyrotropin (TSH) nycthemeral pattern is known to be strongly influenced by sleep, but previous studies have failed to demonstrate any link between sleep structure and TSH variations. Using 10-min blood sampling, nocturnal TSH profiles were analysed in 24 young healthy subjects during normal sleep. Six of the subjects then underwent a partial sleep deprivation experiment, sleep was permitted from 03.00 hours to 07.00 hours. Descending slopes of TSH values were observed for the first 20 minutes of SWS episodes, whereas no significant trend was found for other sleep stages. During the period of sleep deprivation, nocturnal TSH levels increased and then declined immediately after sleep onset; however, the association between SWS and descending TSH slopes persisted. This temporal concordance suggests that some particular mechanisms associated with SWS may modulate TSH release, or conversely that increasing TSH levels prevent the occurrence of SWS.     

Efficacy and safety of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. Multicenter phase III clinical trials. Efficacy of early imaging

The efficacy of contrast-enhanced magnetic resonance imaging (MRI) for detecting and characterizing, or excluding, hepatic masses was assessed in 404 patients, following the intravenous administration of mangafodipir trisodium (MnDPDP) injection, a hepatic MRI contrast agent. An initial contrast-enhanced computed tomography (CT) examination was followed by unenhanced MRI, injection of MnDPDP (5 micromol/kg IV), and enhanced MRI at 15 minutes post injection. Agreement of the radiologic diagnoses with the patients' final diagnoses was higher for enhanced MRI and for the combined unenhanced and enhanced MRI evaluations than for unenhanced MRI alone or enhanced CT using the clinical diagnosis as the gold standard. Mangafodipir-enhanced MRI uniquely provided additional diagnostic information in 48% of the patients, and patient management was consequently altered in 6% of the patients. MnDPDP-enhanced MRI was comparable or superior to unenhanced MRI and enhanced CT for the detection, classification, and diagnosis of focal liver lesions in patients with known or suspected focal liver disease.