Citations

Infections caused by the Bartonella species are responsible for the human diseases collectively called ‘bartonellosis’. The clinically important human infections are mostly caused by the three species (eg, B. bacilliformis, B. quintana and B. henselae) of Bartonella out of the many progressively increasing identified species. Bartonella henselae transmitted by the arthropod vector, fleas, after cat bite is responsible for the rare multisystem cat scratch disease in humans. We present an extremely rare case of B. henselae contracted presumably through a red ant bite. The patient had a prolonged hospital stay for persistent encephalopathy due to delay in diagnosis and initiation of antimicrobial therapy. His hospital course was complicated by two episodes of pulseless electrical activity cardiac arrest related to pulmonary embolism. However, he recovered to his baseline status in the hospital with timely administration of systemic anticoagulation and antimicrobials. He was discharged home with no neurological deficits.

High-dose glucocorticoid treatment results in protein wasting. To determine whether such therapy affects leucine oxidation in the postabsorptive state and the disposal of dietary amino acids, eight normal subjects were studied twice in random order, once after 5 days of prednisone (20 mg three times daily) and on a second occasion without prednisone as a control. In the postabsorptive state prednisone therapy increased (P less than 0.05) plasma concentrations of leucine, alpha-ketoisocaproate, glucose, insulin, and C-peptide, as well as leucine carbon flux and oxidation calculated by means of isotope dilution techniques and [1-13C]leucine. During infusion of a chemically defined meal, total leucine carbon flux and oxidation increased similarly on both study days, but leucine oxidation was greater (P less than 0.01) during prednisone treatment; net leucine balance became positive on the control day but remained negative or zero on the prednisone study day despite higher (P less than 0.05) plasma insulin concentrations. These studies demonstrate that high-dose glucocorticoid treatment impairs the balance of the essential amino acid leucine in both the postabsorptive and absorptive states in humans.

We previously proposed that, during the infusion of either labeled leucine or its alpha-ketoacid, alpha-ketoisocaproate (KIC), the plasma specific activity (SA) of the transaminated product of the infused tracer ("reciprocal pool SA") may better reflect the intracellular leucine SA than the plasma SA of either infused tracer ("primary pool SA"). To test this hypothesis, 14 dogs were simultaneously infused intravenously with [3H]leucine and [14C]KIC, and blood and tissue compartments were sampled. The ratios of [3H]-leucine to [14C]leucine [( 3H]/[14C]leucine) in mixed tissue proteins and in the intracellular space of striated muscle were the same as the ratio of the isotope infusion rates and similar, although slightly lower (P less than 0.01), than [3H]KIC/[14C]leucine SA (ratio of reciprocal pool SA) in plasma. Plasma [3H]KIC/[14C]leucine SA were essentially identical to the [3H]/[14C] of leucine in 1) mixed liver proteins, 2) intrahepatic free leucine, and 3) fibrin. The [3H]/[14C]leucine in mixed renal proteins and in the intracellular space of kidney and erythrocytes were similar to those of the venous plasma [3H]/[14C]leucine SA. The plasma [3H]KIC and [14C]leucine SA (the reciprocal pool SA) were similar to the SA of [3H]- and [14C]leucine in the intracellular space of all organs investigated with the exception of kidney. Therefore, in postabsorptive dogs, the plasma SA of the transaminated product of the infused labeled KIC or leucine is an excellent predictor of the intracellular leucine SA in all tissues investigated with the exception of kidney.

OBJECTIVE Intensive treatment (INT) of type 1 diabetes reduces the incidence of cardiovascular disease (CVD) events compared with conventional treatment (CONV), but it also results in more weight gain. Our objective was to examine whether excessive weight gain from INT of type 1 diabetes is independently associated with subsequent CVD events. RESEARCH DESIGN AND METHODS Quartiles (Q) of weight gain in 1,213 participants aged 18 years and older at enrollment in the Diabetes Control and Complications Trial (DCCT) were determined within randomized treatment groups (INT vs. CONV) using change in BMI from baseline to the closeout DCCT visits. Effects of this weight gain on CVD risk factors and outcomes during an additional 20 years of observational follow-up were then determined. RESULTS The Q4 INT group experienced greater proportional weight gain (median change in BMI, 6.08 kg/m2), increases in CVD risk factors, and need for medications for hypertension and lipids compared with the Q1–3 INT and comparable CONV groups. Over a mean of 26 years of follow-up, the numbers of major and total CVD events were not statistically different in Q4 compared with Q1–3 of either the INT or CONV group. By year 14, however, the incident CVD event curve became significantly higher in the Q4 INT group than in the Q1–3 INT groups (P = 0.024) and was similar to that for the CONV group. CONCLUSIONS For the first 13 years after DCCT, INT for type 1 diabetes reduced macrovascular events compared with CONV, even when excessive weight gain occurred. After this, total CVD events significantly increased in the Q4 INT group, becoming equivalent to those in the CONV group. Longer follow-up is needed to determine whether this trend continues and results in more major CVD events.

Alterations in nuclear morphology are common in cancer progression. However, the degree to which gross morphological abnormalities translate into compromised higher‐order chromatin organization is poorly understood. To explore the functional links between gene expression and chromatin structure in breast cancer, we performed RNA‐seq gene expression analysis on the basal breast cancer progression model based on human MCF10A cells. Positional gene enrichment identified the major histone gene cluster at chromosome 6p22 as one of the most significantly upregulated (and not amplified) clusters of genes from the normal‐like MCF10A to premalignant MCF10AT1 and metastatic MCF10CA1a cells. This cluster is subdivided into three sub‐clusters of histone genes that are organized into hierarchical topologically associating domains (TADs). Interestingly, the sub‐clusters of histone genes are located at TAD boundaries and interact more frequently with each other than the regions in‐between them, suggesting that the histone sub‐clusters form an active chromatin hub. The anchor sites of loops within this hub are occupied by CTCF, a known chromatin organizer. These histone genes are transcribed and processed at a specific sub‐nuclear microenvironment termed the major histone locus body (HLB). While the overall chromatin structure of the major HLB is maintained across breast cancer progression, we detected alterations in its structure that may relate to gene expression. Importantly, breast tumor specimens also exhibit a coordinate pattern of upregulation across the major histone gene cluster. Our results provide a novel insight into the connection between the higher‐order chromatin organization of the major HLB and its regulation during breast cancer progression.

Abstract Background: Protein kinase Cβ (PKCβ) is critical for B-cell signaling and survival and overexpression of PKCβ in DLBCL is associated with inferior survival. ENZA, an oral serine/threonine kinase inhibitor, targets PKCβ. Here we report immunohistochemical (IHC) and fluorescence in-situ hybridization (FISH) correlative analyses. Methods: PRELUDE (NCT00332202) was a phase III, double-blind maintenance study of 758 pts with DLBCL who were randomized 2:1 to ENZA 500 mg daily (1125-mg loading dose) (n = 504) or PBO (n = 254), respectively, following CR to induction therapy with R-CHOP. The primary endpoint was disease-free survival (DFS). Overall survival (OS) and assessment of biomarkers specific to ENZA and DLBCL were secondary endpoints. Pre-treatment formalin-fixed, paraffin-embedded samples were assessed via IHC staining in a blinded manner (Eric Hsi) for cell of origin (COO) using Hans’ algorithm. In addition, IHC was performed for c-MYC, BCL2, BCL6, FOXP1, and MUM1 (10% increments/% tumor cells stained), markers relevant to ENZA, including PKCβ2. FISH was performed to identify translocations involving c-MYC, BCL2, and BCL6. Cox regression was used to determine statistical associations between efficacy outcomes and dichotomized markers, adjusting for treatment and additional baseline covariates. All tests of association were conducted at a 2-sided α = 0.05. Results: There was no difference in 4-year DFS (70% vs 71%) or OS (81% vs 82%) between ENZA and PBO arms, respectively. A total of 243 (32%) pts had ≥1 evaluable sample available for IHC and FISH. There was no difference in outcome for pts based on COO (GCB vs non-GCB). Independent of treatment, significant associations were observed for BCL2 (pre-specified cutpoint 20%) and MUM1 (cutpoint 30%) with OS, and FOXP1 (cutpoint 80%) by IHC with DFS (HR [95% CI]: 2.19 [1.01-4.73]), p = 0.031; 1.97 [1.04-3.71], p = 0.032; 1.74 [1.04-2.90], p = 0.032, respectively). Associations were not significant for other IHC markers, including c-MYC and BCL6. Low PKCβ2 (<50% expression) had numerically better (but not significant) DFS/OS vs high PKCβ2. Dual translocation lymphoma by FISH was identified in two pts (1.2%) each for c-MYC/BCL2 and c-MYC/BCL6, and one pt (0.6%) had a triple hit involving c-MYC/BCL2/BCL6. Conclusions: No difference in outcomes between treatment arms was observed for the trial. Independent of treatment, COO was not prognostic of outcomes. Pts with low PKCβ2 expression had numerically better DFS/OS compared with high PKCβ2 expression. Significant treatment-independent associations were observed for BCL2 and MUM1 with OS and for FOXP1 with DFS (low IHC expression corresponded to better outcomes). The small number of double hit and triple hit lymphomas seen in the study may reflect the enrollment of CR patients with more favorable biology. Citation Format: Eric D. Hsi, Kerry J. Savage, Sonali M. Smith, Fritz Offner, Scott P. Myrand, Thomas M. Habermann, Donald E. Thornton, Boris K. Lin, Tuan S. Nguyen, Oday Hamid, Michael Crump. Correlative results from PRELUDE, a phase III study of enzastaurin (ENZA) vs placebo (PBO) in patients (pts) with high-risk diffuse large B-cell lymphoma (DLBCL) following a response to R-CHOP therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5303. doi:10.1158/1538-7445.AM2015-5303

Trafficking from bedside to bench Typically in translational research, a discovery in cell or molecular biology is later exploited to improve patient care. Occasionally, information flows in the opposite direction. Lo et al. found that patients with an autoimmune disorder caused by deficiency of a protein called LRBA responded dramatically to the drug abatacept (see the Perspective by Sansom). Abatacept contains a segment of a potent inhibitory immune receptor, CTLA4. Experiments prompted by this observation revealed the relationship between the two proteins: LRBA controls the intracellular trafficking and degradation of CTLA4. This information may further improve patient care, because other clinically approved drugs have the desired mechanism of action with potentially fewer side effects. Science , this issue p. 436 ; see also p. 377

ABSTRACTThe organization of interphase chromosomes in chromosome territories (CTs) was first proposed more than one hundred years ago. The introduction of increasingly sophisticated microscopic and molecular techniques, now provide complementary strategies for studying CTs in greater depth than ever before. Here we provide an overview of these strategies and how they are being used to elucidate CT interactions and the role of these dynamically regulated, nuclear‐structure building blocks in directly supporting nuclear function in a physiologically responsive manner. J. Cell. Biochem. 117: 9–19, 2016. © 2015 Wiley Periodicals, Inc.

Three‐dimensional organization of the chromatin has important roles in transcription, replication, DNA repair, and pathologic events such as translocations. There are two fundamental ways to study higher‐order chromatin organization: microscopic and molecular approaches. In this review, we briefly introduce the molecular approaches, focusing on chromosome conformation capture or “3C” technology and its derivatives, which can be used to probe chromatin folding at resolutions beyond that provided by microscopy techniques. We further discuss the different types of data generated by the 3C‐based methods and how they can be used to answer distinct biological questions. J. Cell. Physiol. 230: 31–35, 2016. © 2015 Wiley Periodicals, Inc.