Bacillus cereus septicemia in a patient with severe aplastic anemia

A 78-year-old female was admitted with complaints of malaise and fatigue in the legs. The patient was diagnosed as severe aplastic anemia and treatment was started with metenolone and steroid pulse therapy. Administration of antibiotics and granulocyte-colony stimulating factor which led to a resolution of the high fever. About four months after admission, the patient developed vomiting and abdominal pain with a spiking fever. The next day after suddenly losing consciousness, she died. B. cereus was isolated from blood cultures. Autopsy specimens of the liver, cardiac muscle and lung showed changes due to B. cereus. This pathogen is widely distributed in nature. We should not overlook B. cereus as a contamination, but rather should consider it a potential pathogen in immunocompromised hosts, when it is isolated from blood cultures.     

Ultrastructure of the rat periodontal ligament as observed with quick-freeze, deep-etch and replica methods: arrangement of collagen and related structures

The ultrastructure of the periodontal ligament of rat molars was examined with the quick-freeze, deep-etch replica methods. It was mainly composed of elongated fibroblast-like cells and 40- to 50-nm-wide collagen fibrils that are arranged parallel to one another to form fibers approximately 1 micron in width. Collagen fibrils are composed of 10-nm-wide substructures that may run helically against the long axis of the fibril. Numerous rod-like structures ('rods') approximately 10 nm in width are present around the collagen fibrils. Individual or groups of rods span spaces between neighboring collagen fibrils to interconnect them. The surfaces of the fibroblast-like cells are also connected to the nearest collagen fibrils through the rods. In place, strands with a thickness similar to that of the rods were seen self-assembled into irregular meshwork structures. The treatment of the tissue with 10% sodium hydroxide for up to 5 days removed most of these rods and strands, thus exposing a three-dimensional arrangement of collagen fibrils that is often not fully visualized in untreated tissues. With histochemical staining of thinly sectioned tissues using Alcian blue, these rods and strands were positively stained, and thus they were demonstrated to be composed of proteoglycans. The ultrastructural arrangement of the periodontal ligament, observed in this study as a delicate interaction of collagen and proteoglycan components, is likely to play a significant role in the transmission of occlusal forces applied to the tissue and in the dissipation of mechanical shock.     

Growth on urea can trigger death and peroxidation of the cyanobacterium Synechococcus sp. strain PCC 7002

Laboratory conditions have been identified that cause the rapid death of cultures of cyanobacteria producing urease. Once the death phase had initiated in the stationary growth phase, cells were rapidly bleached of all pigmentation. Null mutations in the ureC gene, encoding the alpha subunit of urease, were constructed, and these mutants were no longer sensitive to growth in the presence of urea. High levels of peroxides, including lipid peroxides, were detected in the bleaching cells. Exogenously added polyunsaturated fatty acids triggered a similar death response. Vitamin E suppressed the formation of peroxides and delayed the onset of cell bleaching. The results suggest that these cyanobacterial cells undergo a metabolic imbalance that ultimately leads to oxidative stress and lipid peroxide formation. These observations may provide insights into the mechanism of sudden cyanobacterial bloom disappearance in nature.     

Induction of plasminogen activator inhibitor type 1 and type 1 collagen expression in rat cardiac microvascular endothelial cells by interleukin-1 and its dependence on oxygen-centered free radicals

BACKGROUND: Ischemia with or without reperfusion induces the release of diverse products from monocytes, including cytokines such as interleukin-1 (IL-1). To determine whether these phenomena modulate fibrinolysis and potentially exacerbate impairment of the macrocirculation, microcirculation, or both, we characterized the effects of IL-1 on the expression of fibrinolytic system and matrix proteins in rat cardiac microvascular endothelial cells (CMECs). METHODS AND RESULTS: Confluent CMECs were exposed to IL-1 in serum-free medium for 24 hours, and cell-conditioned medium was assayed for plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of plasminogen activators, and for type 1 collagen with Western blotting. IL-1 (2 ng/mL) specifically increased the accumulation of PAI-1 (4.4 +/- 0.6-fold; mean +/- SD; n = 9) without affecting tissue plasminogen activator (t-PA) or urokinase plasminogen activator (u-PA) levels, which remained unchanged. IL-1 increased the accumulation of collagen in conditioned media by 3.5 +/- 0.7-fold (n = 6). Conversely, the accumulation of both PAI-1 and collagen induced by IL-1 was inhibited with an IL-1 receptor antagonist (200 ng/mL; n = 6) and with cycloheximide (10 micrograms/mL; n = 6), implying that protein synthesis was a requirement for the effect. To determine whether the IL-1 effect was mediated by induction of oxygen-centered free radical production, known to be induced by IL-1, we exposed the cells to the hydroxyl radical scavenger tetramethylthiourea (10 mmol/L) and observed abolition of the IL-1-induced increase in the expression of PAI-1 and collagen (n = 6). Conversely, superoxides (generated with 10 mU/mL xanthine oxidase plus 0.6 mmol/L hypoxanthine, and 100 mumol/L hydrogen peroxide) induced the accumulation of PAI-1 and collagen (n = 6). IL-1 (1 microgram/kg body wt) and lipopolysaccharide (50 micrograms/kg body wt) administered in vivo increased PAI-1 protein in rat hearts as detected with Western blotting and PAI-1 immunostaining of rat heart microvessels, indicating the effects delineated in vitro were paralleled by effects in vivo. CONCLUSIONS: These results indicate that IL-1-induced oxygen-centered free radicals stimulate elaboration of PAI-1 and collagen by CMECs. Accordingly, microvascularly mediated inhibition of fibrinolysis may predispose to the persistence of microvascular thrombi, thereby contributing to impaired microcirculatory function, the no-reflow phenomenon, and cardiac dysfunction after ischemia and reperfusion.     

Clinical features and characteristics of paranasal sinus effusion in allergic sinusitis

Paraproteins or monoclonal proteins are the result of clonal B-cell or plasma cell proliferation of a malignant, premalignant or non-malignant nature. Monoclonal proteins may consist of intact immunoglobulin molecules or of heavy or light chains only. Depending on their rate of production and/or secretion they may accumulate in the serum and/or urine of patients. Their presence in the circulation may remain silent, as in monoclonal gammopathy of undetermined significance (MGUS), or may lead to clinical syndromes such as Hyperviscosity, Acrocyanosis, Cold hemagglutination, hemolysis and hemorrhagic manifestations. Their tissue deposition may be localized, with the kidney being the most frequent target as in Myeloma Cast Nephropathy or systemic, as in AL amyloidosis where heart, liver, nerves, tongue are usual targets, in addition to the kidneys.     

Cultural accommodation: Hybridity and the framing of social obligation.

Implications of cultural accommodation–hybridization were explored within the framework of individualism–collectivism. Individualism highlights the personal and centralizes individuals as the unit of analyses, whereas collectivism highlights the social and contextualizes individuals as parts of connected social units. In 2 experiments, the ways in which individualism, collectivism, and identity salience influence social obligation to diverse others was explored. The authors varied the personal goal interrupted (achievement–pleasure), the target (individual–group), and focus (in-group–larger society) of social obligation within subjects. The authors hypothesized that collectivism would increase obligation to the in-group when identity was made salient; that individualism alone would dampen social obligation; and that cultural accommodation–hybridization (being high in both individualism and collectivism) would increase obligation to larger society. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Two distinct patterns of peritoneal involvement shown by in vitro and in vivo ovarian cancer dissemination models

We established an in vitro peritoneal dissemination model using six ovarian cancer cell lines and cultured mesothelial cells. Ovarian cancer cells were classified into two types, invasive or adhesive, on the basis of their interaction with the mesothelial cell monolayer. The ovarian cancer cell lines derived from mucinous cystadenocarcinoma, poorly differentiated adenocarcinoma and undifferentiated carcinoma, which belonged to the invasive type, began to invade beneath the mesothelial monolayer from several hours after seeding in vitro, expelling the mesothelial cells at the periphery and forming colonies directly on the dish surface. On the other hand, cancer cell lines of clear cell carcinoma, which belonged to the adhesive type, showed colony formation with adhesion on the mesothelial monolayer even 18 h after seeding. Invasive-type cell lines invaded into the mesothelial monolayer at various rates in vitro, and the degree of invasiveness showed good correlation with the degree of peritoneal dissemination in vivo after intraperitoneal injection of cancer cells into nude mice. Adhesive-type cells showed rather higher dissemination rates in vivo. Microscopic observation of in vivo peritoneal dissemination at one day after inoculation also revealed two patterns of peritoneal involvement similar to those in vitro. In the in vitro model, anti-integrin alpha 2- and beta 1-antibodies inhibited the infiltration of invasive-type cells into the mesothelial monolayer, but did not affect colony formation by adhesive-type cells on the monolayer, indicating that invasion by both cell types was mediated by different molecules. This in vitro model is thought to be useful for analysis of the molecular mechanisms of peritoneal dissemination.     

A family of infantile genetic agranulocytosis

A survey was performed of the mold flora in the air and on the surfaces inside twelve homes throughout four seasons. There were significant variations of the mold flora in homes associated with the outdoor spore count, various rooms, carpeting, central air-conditioning and pets. We conclude that homes may be a source of perennial mold exposure.