Tuberculosis masquerading as malignancy: a multimodality approach to the correct diagnosis – a case report

BACKGROUND: Extrapulmonary tuberculosis is one of the great mimickers of medicine, and often masquerades as malignancy. As a result, patients may be referred to oncologists and surgeons for further evaluation and management, delaying the institution of appropriate anti-tuberculous drug therapy. CASE PRESENTATION: We present the case of a 21 year old man with tuberculous osteomyelitis, who was referred to the Bone and Soft Tissue Sarcoma Service at our institution with a provisional diagnosis of malignancy. Further investigation revealed extensive retroperitoneal abdominal and pelvic lymphadenopathy. The recognition of certain patterns on imaging, and finally the isolation of Mycobacterium tuberculosis from tissue samples obtained under image guidance, enabled the correct diagnosis to be made. CONCLUSION: This case highlights the importance of remaining cognisant of the protean manifestations of extrapulmonary tuberculosis, and illustrates the advantage of a clinically directed multi-modality imaging approach to diagnosis.     

Advantages of granivory in seasonal environments: feeding ecology of an arboreal seed predator in Amazonian forests

Specialized seed predators are uncommon in arboreal vertebrate assemblages, and the hypothesis that consuming seeds of immature fruits – which may be available for relatively long periods compared to mature fruit – could reduce seasonal food scarcity experienced by generalist frugivores remains largely untested. To test this hypothesis, we examined the diet and feeding ecology of bald‐faced saki monkeys Pithecia irrorata in a largely intact forest mosaic of southeastern Peru based on systematic monitoring of five habituated groups over a three‐year period and compared the relative availability of ripe and unripe fruits in their diet. Plant phenology data from individual tree crowns showed that, compared to ripe fruits, immature fruits were available in more tree species, in greater quantities, and for longer periods. Despite pronounced community‐wide seasonal changes in fruit production at our study area, feeding patterns of bald‐faced saki remained largely invariant: fruits comprised approximately 95% of the species’ monthly diet, with seeds alone accounting for 75%, with no major monthly dietary shifts. The flexible exploitation by this species of a consistently available food supply for which it faces little competition likely reduces foraging effort and consumption of less desirable foods, even during prolonged periods of overall fruit scarcity. The relative rarity of immature fruit specialists in tropical forests may reflect the fact that processing the hard pericarps and neutralizing the toxicities of immature seeds present substantial evolutionary hurdles that few arboreal vertebrate species have overcome.     

Biosynthesis of prostaglandins and thromboxane B2 by fetal lung homogenates

The conversion of arachidonic acid to prostaglandins (PG's) and thromboxane B₂ (TXB₂) was investigated in homogenates from fetal and adult bovine and rabbit lungs. Adult bovine lungs were very active in converting arachidonic acid (100 μg/g tissue) to both PGE₂ (10.7 μg/g tissue) and TXB₂ (6.2 μ/g tissue). Smaller amounts of PGF_2α (0.9 μ/g) and 6-oxoPGF_1α were formed. Homogenates from fetal calf lungs during the third trimester of pregnancy were quite active in converting arachidonic acid to PGE₂, but formed very little TXB₂, PGF_2α or 6-oxoPGF_1α. Homogenates from rabbit lungs converted arachidonic acid (100 μg/g) mainly to PGE₂, both before and after birth. The amount of PGE₂ formed increased during gestation to a maximum of about 6 μg/g tissue at 28 days of gestation. It then decreased to a minimum (1.5 μg/g) which was observed 8 days after birth, followed by an increase to about 4 μg/g in older rabbits.     

Polymorphic phase behavior of cardiolipin derivatives studied by 31P NMR and X-ray diffraction

The polymorphic phase behavior of cardiolipin (diphosphatidylglycerol) analogues with two to five chains per phospholipid head group, namely, dilysocardiolipin, monolysocardiolipin, cardiolipin, and acylcardiolipin, respectively, has been studied by 31P NMR and X-ray diffraction. Dilysocardiolipin dispersions at low salt concentration are micellar, and a transition to a lamellar phase takes place between 1 and 2 M NaCl. From light-scattering measurements, it is also found that a transition takes place from the micellar state with a midpoint at 5.2 mM CaCl2, 0.95 M HClO4, and 1.5 M NaCl. Monolysocardiolipin dispersions are lamellar throughout the concentration range from zero to saturated NaCl. Cardiolipin dispersions undergo a transition from a lamellar to an inverted hexagonal phase between 1 and 2 M NaCl. Acylcardiolipin dispersions are in an inverted hexagonal phase throughout the concentration range from zero to saturated NaCl. The chemical shift anisotropies of both phosphate groups in dilysocardiolipin and of one of the phosphate groups in monolysocardiolipin are drastically reduced in the lamellar phase, indicating a different conformation of the phosphatidyl head group from that normally found in diacyl phospholipid bilayers. The results provide strong support for the "shape" concept of lipid polymorphism when viewed in its most general form including configurational entropy, hydrophobic effects, etc. and indicate the importance of head-group interactions in determining the lipid phase behavior.     

The latitudinal position of peak marine diversity in living and fossil biotas

Aim Peak marine taxonomic diversity has only rarely occurred at or near the equator during the Phanerozoic Eon, in contrast to the present‐day pattern. This fundamental difference is difficult to reconcile because the latitude at which peak diversity occurs for living marine taxa has not yet been explicitly determined at a broad taxonomic and spatial scale. Here, we attempt to determine this value in order to compare the contemporary and fossil patterns directly. Location Our data are global in coverage. Methods We used a literature compilation of 149 present‐day marine latitudinal diversity gradients. We summed the number of marine taxa that exhibited peak diversity within 10° latitudinal bins. In addition, we recorded locality data, general habitat (benthic/pelagic), and the taxonomic level of the study organisms. Results We found that peak diversity for most sampled marine taxa currently occurs between 10° and 20° N, even after correcting for a Northern Hemisphere sampling bias. Moreover, this peak position is a global phenomenon: it is found across habitats and higher taxa, within all sampled ocean basins, and on both sides of the Atlantic and Pacific oceans. Benthic taxa, which dominate our data, exhibit one peak at 10°–20° N, while pelagic taxa exhibit a peak at 10°–20° N and an additional peak at 10°–20° S, producing a distinct trough at the equator. Main conclusions Our data indicate that peak marine diversity for many taxa is currently within 10°–20° N rather than at the equator, and that this is not likely to result from either undersampling at lower latitudes or the pattern being dominated by a particular taxon. Possible explanations may include a coincidence with the intertropical convergence zone, a mid‐domain effect, abundant shallow marine habitat, or high ocean temperatures at latitudes nearest the equator. Regardless of its exact cause, the position of peak diversity should be considered a fundamental feature of the latitudinal diversity gradient that must be accounted for within attempts to explain the latter’s existence.     

Hyperoxia-induced apoptosis and Fas/FasL expression in lung epithelial cells

Alveolar epithelial apoptosis is an important feature of hyperoxia-induced lung injury in vivo and has been described in the early stages of bronchopulmonary dysplasia (chronic lung disease of preterm newborn). Molecular regulation of hyperoxia-induced alveolar epithelial cell death remains incompletely understood. In view of functional involvement of Fas/FasL system in physiological postcanalicular type II cell apoptosis, we speculated this system may also be a critical regulator of hyperoxia-induced apoptosis. The aim of this study was to investigate the effects of hyperoxia on apoptosis and apoptotic gene expression in alveolar epithelial cells. Apoptosis was studied by TUNEL, electron microscopy, DNA size analysis, and caspase assays. Fas/FasL expression was determined by Western blot analysis and RPA. We determined that in MLE-12 cells exposed to hyperoxia, caspase-mediated apoptosis was the first morphologically and biochemically recognizable mode of cell death, followed by necrosis of residual adherent cells. The apoptotic stage was associated with a threefold upregulation of Fas mRNA and protein expression and increased susceptibility to direct Fas receptor activation, concomitant with a threefold increase of FasL protein levels. Fas gene silencing by siRNAs significantly reduced hyperoxia-induced apoptosis. In murine fetal type II cells, hyperoxia similarly induced markedly increased Fas/FasL protein expression, confirming validity of results obtained in transformed MLE-12 cells. Our findings implicate the Fas/FasL system as an important regulator of hyperoxia-induced type II cell apoptosis. Elucidation of regulation of hyperoxia-induced lung apoptosis may lead to alternative therapeutic strategies for perinatal or adult pulmonary diseases characterized by dysregulated type II cell apoptosis.     

Replication of cytomegalovirus in human arterial smooth muscle cells.

Cytomegalovirus (CMV) strain AD-169 replicated in smooth muscle cell (SMC) cultures derived from human umbilical arteries, producing enveloped infectious virions. However, unlike the effects of CMV on fully permissive human lung fibroblasts, the effects of strain AD-169 on SMC cultures were delayed and prolonged, resulting in extended survival of a fraction of the starting population. This period of survival did not exceed the life-span of the control SMC cultures. Infectious CMV continued to be isolated from the surviving SMC cultures after extinction of the original inoculum by dilution and after treatment of the cultures with CMV neutralizing antibody. The implications of these findings for the pathogenesis of atherosclerosis are discussed.     

A high incidence of parasitism ofHeliothis SPP. [Lep.: Noctuidae] larvae in cotton in Southeastern Arkansas

During 1981 and 1982, bollworm,Heliothis zea (Boddie), and tobacco budworm,H. virescens (F.), larvae (n=3,666) were collected from 41 cotton fields near Portland, Arkansas (USA) to assess the occurrence of parasitism. Three strategies were employed to controlHeliothis spp. in these fields: (1) release ofTrichogramma pretiosum Riley; (2) insecticidal control; or (3) inaction (check). Insecticide use in nonchemical control fields was reduced, but not eliminated.Heliothis spp. larvae collected in cotton had higher parasitism rates in 1981 (30.9%) and 1982 (50.1%) than had been reported for cotton since the advent of organochlorine insecticide usage. Four species of larval parasites and 1 species of larval-pupal parasite were recorded. The larval parasiteMicroplitis croceipes (Cresson) comprised 90.6% and 94.5% of all parasitic insects reared from field collectedHeliothis spp. in 1981 and 1982, respectively. No difference (P>0.05) in level of parasitism existed betweenH. zea andH. virescens. Differences between treatments occurred only in 1982 whenH. zea larvae were parasitized at a greater (P<0.05) rate in check fields (68.3%) than in insecticidal control fields (44.3%). Higher levels of larval parasitism in cotton fields may be a consequence of reduced insecticide usage and changes in materials applied, particularly the pyrethroids. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Dept. of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.