Rapid growth hormone measurement during transsphenoidal surgery: analysis of 252 acromegalic patients

The usefulness of rapid growth hormone (GH) measurement was retrospectively evaluated as an indicator of total tumor removal during surgery and compared with several reported criteria in 252 acromegalic patients who underwent transsphenoidal surgery at Toranomon Hospital between 2006 and 2008. GH levels were measured in blood samples obtained before surgery, at the start of tumor removal, and every 20 minutes thereafter until 20 minutes after total tumor removal as judged by the operator. Intraoperative GH dynamics were compared between 201 patients fulfilling the Cortina consensus criteria (successful group) and 37 patients who did not (unsuccessful group). Among several criteria indicating total tumor removal, only the ratio of serum GH level 20 minutes after the end of tumor removal to GH level at the end of tumor excision was significantly different between the groups; a reduction ratio of 65% was the most appropriate cut-off value based on sensitivity (59.2%) and specificity (59.5%). The ratio of GH level 20 minutes after the end of tumor removal/GH level at the end of tumor excision was the most reliable index to judge tumor removal during surgery, but this index is neither necessary nor sufficient and should be used as one of the indicators to judge complete tumor removal during surgery.     

Deep sequencing reveals stepwise mutation acquisition in paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a nonmalignant clonal disease of hematopoietic stem cells that is associated with hemolysis, marrow failure, and thrombophilia. PNH has been considered a monogenic disease that results from somatic mutations in the gene encoding PIGA, which is required for biosynthesis of glycosylphosphatidylinisotol-anchored (GPI-anchored) proteins. The loss of certain GPI-anchored proteins is hypothesized to provide the mutant clone with an extrinsic growth advantage, but some features of PNH argue that there are intrinsic drivers of clonal expansion. Here, we performed whole-exome sequencing of paired PNH⁺ and PNH^– fractions on samples taken from 12 patients as well as targeted deep sequencing of an additional 36 PNH patients. We identified additional somatic mutations that resulted in a complex hierarchical clonal architecture, similar to that observed in myeloid neoplasms. In addition to mutations in PIGA, mutations were found in genes known to be involved in myeloid neoplasm pathogenesis, including TET2, SUZ12, U2AF1, and JAK2. Clonal analysis indicated that these additional mutations arose either as a subclone within the PIGA-mutant population, or prior to PIGA mutation. Together, our data indicate that in addition to PIGA mutations, accessory genetic events are frequent in PNH, suggesting a stepwise clonal evolution derived from a singular stem cell clone.     

Influence of Hip Joint Position on Muscle Activity during Prone Hip Extension with Knee Flexion

[Purpose] This study investigated the selective activation of the gluteus maximus during a prone hip extension with knee flexion exercise, with the hip joint in different positions. [Subjects] The subjects were 21 healthy, male volunteers. [Methods] Activities of the right gluteus maximus, right hamstrings, bilateral lumbar erector spinae, and bilateral lumbar multifidus were measured using surface electromyography during a prone hip extension with knee flexion exercise. Measurements were made with the hip joint in each of 3 positions: (1) a neutral hip joint position, (2) an abduction hip joint position, and (3) an abduction with external rotation hip joint position. [Results] Gluteus maximus activity was significantly higher when the hip was in the abduction with external rotation hip joint position than when it was in the neutral hip joint and abduction hip joint positions. Gluteus maximus activity was also significantly higher in the abduction hip joint position than in the neutral hip joint position. Hamstring activity was significantly lower when the hip was in the abduction with external rotation hip joint position than when it was in the neutral hip joint and abduction hip joint positions. [Conclusion] Abduction and external rotation of the hip during prone hip extension with knee flexion exercise selectively activates the gluteus maximus.Key words: Prone hip extension with knee flexion, Hip joint position, Electromyography     

Primary varicella infection in children with systemic juvenile idiopathic arthritis under tocilizumab therapy

Abstract

We report the clinical course and outcome of primary varicella infection in six children with systemic juvenile idiopathic arthritis (sJIA) receiving tocilizumab. None had disseminated or fatal varicella infection, but one patient developed macrophage activation syndrome (MAS) and another had an arthritis relapse. All patients had a significant elevation of serum IL-6 levels, and the two children who developed MAS or arthritis relapse showed high serum IL-18 levels, which could cause a sJIA flare-up.     

Conditional ablation of HMGB1 in mice reveals its protective function against endotoxemia and bacterial infection

High-mobility group box 1 (HMGB1) is a DNA-binding protein abundantly expressed in the nucleus that has gained much attention for its regulation of immunity and inflammation. Despite this, whether and how HMGB1 contributes to protective and/or pathological responses in vivo is unclear. In this study, we constructed Hmgb1-floxed (Hmgb1^f/f) mice to achieve the conditional inactivation of the gene in a cell- and tissue-specific manner by crossing these mice with an appropriate Cre recombinase transgenic strain. Interestingly, although mice with HMGB1 ablation in myeloid cells apparently develop normally, they are more sensitive to endotoxin shock compared with control mice, which is accompanied by massive macrophage cell death. Furthermore, these mice also show an increased sensitivity to Listeria monocytogenes infection. We also provide evidence that the loss of HMGB1 in macrophages results in the suppression of autophagy, which is commonly induced by lipopolysaccharide stimulation or L. monocytogenes infection. Thus, intracellular HMGB1 contributes to the protection of mice from endotoxemia and bacterial infection by mediating autophagy in macrophages. These newly generated HMGB1 conditional knockout mice will serve a useful tool with which to study further the in vivo role of this protein in various pathological conditions.Of the four members of the high-mobility group box (HMGB) family, HMGB1 is the best studied, given its versatile functions in various aspects of cellular responses (1–5). Ubiquitously expressed in all cells, HMGB1 is found en masse in the nucleus and is supposedly released into the extracellular fluid through an endoplasmic reticulum–Golgi pathway-independent mechanism from immune cells such as monocytes or macrophages after stimulation with lipopolysaccharide (LPS), proinflammatory cytokines, or nitric oxide (1, 6). The release of HMGB1 is also regulated by the inflammasome, a multiprotein oligomer that activates caspase-1 to promote the maturation of inflammatory cytokines, interleukin-1β (IL-1β) and IL-18, and by dying cells, typically those undergoing necrosis (7–10). Secreted or released, HMGB1 is known to participate in the activation of cell surface innate immune receptors, typically Toll-like receptors (TLRs), thereby affecting many aspects of the host’s inflammatory responses upon infection or noxious stresses (1–5). Perhaps most notably is the crucial role of HMGB1 in LPS-induced endotoxemia, whereby administration of an anti-HMGB1 antibody significantly protects mice from lethality (1, 11). The study of released HMGB1 is complicated by a number of complex posttranslational modifications made to the protein, including acetylation and redox modifications that may regulate HMGB1 function (12–14).HMGB1 can regulate immune reactions in several ways. Cytosolic HMGB1, together with the other members of the family, function as universal sentinels or chaperones for immunogenic nucleic acids by facilitating the recognition of nucleic acids by more discriminative, nucleic acid-sensing innate receptors (15–17). In addition, HMGB1 regulates autophagy, a cellular response that functions in clearing long-lived proteins and dysfunctional organelles to generate substrates for adenosine triphosphate (ATP) production during periods of starvation and other types of cellular stress events (13, 18–20). This mechanism contributes to antimicrobial responses against invading microorganisms (21, 22). Indeed, microorganisms can induce autophagy by stimulating innate immune receptors, such as TLRs, by a process in which bacteria are captured by phagocytosis but remain within intact vacuoles, an autophagic process termed microtubule-associated protein light chain 3 (LC3)-associated phagocytosis (LAP), which promotes the maturation of autophagosomes into autolysosomes (23, 24).Collectively, these studies place HMGB1 in the center of immunological events where it uniquely functions intracellularly and extracellularly as a mediator of immune and inflammatory responses. The biological and clinical importance of HMGB1 is underscored by the dysregulation of this protein in a number of pathological conditions, including sepsis, ischemia–reperfusion injury, arthritis, and cancer (1, 3–5). Nonetheless, in vivo validation of the versatile functions described above is lacking due to the lethality of the Hmgb1-deficient mice, thought to cause lethal hypoglycemia in newborn mice (25). In the present study, we describe the generation of Hmgb1-floxed (Hmgb1^f/f) mice that enabled the cell- and tissue-specific deletion of the gene when crossed with an appropriate Cre recombinase transgenic strain. We demonstrate in this study a protective role of intracellular HMGB1 in macrophages where it serves as a crucial regulator of autophagosome formation in the context of LPS stimulation or bacterial infection in vivo. Finally, we will discuss the future prospects of HMGB1 research using these newly generated mutant mice.