Identification of yeast artificial chromosomes containing the inversion 16 p-arm breakpoint associated with acute myelomonocytic leukemia

We report the cloning of the chromosome 16 p-arm breakpoint involved in inversion 16(p13;q22) associated with subtype of acute myelomonocytic leukemia (AMML) M4Eo. Inter-Alu polymerase chain reaction (PCR) products from a series of interspecific somatic cell hybrids that contain only small portions of the human chromosome 16 p-arm were generated for use as fluorescent in-situ hybridization (FISH) probes. When applied to patient cells, rapid and unambiguous identification of the inversion resulted. Using FISH analysis, cosmid clones associated with the hybrids were identified that bracketed the p-arm breakpoint. A repeat-free fragment of one of these cosmids (35B11) when used as probe on Southern blots from pulsed-field gels identified rearranged macrorestriction fragments in patient DNA. Yeast artificial chromosomes (YACs) were isolated using sequences derived from cosmids flanking 35B11 in a cosmid contig. Of 4 YACs so identified, 3 were shown by FISH to cross the inversion-16 p-arm breakpoint. Therefore, the breakpoint has been molecularly cloned, and identified as being within these 3 YACs. These clones will facilitate the unraveling of the genetic events associated with inversion-16 and are available tools with immediate clinical application.     

Multicystic biliary hamartoma: A report of a rare entity and a review of the literature

INTRODUCTION

Multicystic biliary hamartoma is a rare liver tumor that was first described in 2005. Only nine cases are reported in the literature and all of them originate from Eastern patient populations, specifically Japan and Korea.

PRESENTATION OF CASE

Herein we report the occurrence of the tenth multicystic biliary hamartoma reported to date, arising in a Caucasian American woman initially presenting with abdominal pain. At 4.7 cm this is the second largest tumor reported to date and the only one arising in a Western patient population.

DISCUSSION

The patient underwent multimodality imaging and the tumor was biopsied preoperatively, but the diagnosis remained unclear. An extended right hepatectomy was performed for resection of her tumor, and the tumor was definitively diagnosed based on the surgically resected specimen. As all nine of the previously reported cases also underwent resection, the natural history of this lesion remains unknown. The lack of both recurrence and tumor spread in the previously reported cases indicates that this may be a benign lesion not requiring surgical resection unless symptomatic.

CONCLUSION

Multicystic biliary hamartoma is an extremely rare tumor. Increased awareness of the radiologic and pathologic features will likely lead to the diagnoses of further cases in both Western and Eastern populations and could potentially assist with preoperative diagnosis. The natural history and optimal management of this tumor remain uncertain.     

Evaluation of developmental toxicity of guaifenesin using pregnant female rats

Objectives:Guaifenesin possesses expectorant, muscle relaxant, and anticonvulsive properties. To the best of our knowledge, the promising data regarding the developmental toxicity of guaifenesin are scarce. The current study investigates the developmental toxic effects of guaifenesin in detail using female rats.Results:A significant reduction in maternal weight, and food/water intake, was observed, however, no mortality and morbidity were observed. About 14 dead fetuses were found in Group-3 and -4 each, while 26 in Group 5. Morphological analysis revealed 21.2%, 45.4%, 67.2%, and 86.9% of total fetuses having hemorrhagic spots in Group-2, -3, -4, and -5, respectively. Dropping wrist/ankle and kinky tail were found in Group-4 and -5 only. Morphometric analysis showed a significant decline in fetal weight, full body length, skull length, forelimb length, hindlimb length, and tail length in all guaifenesin treated groups. Skeletal examination displayed that only Group 5 fetuses had increased intercostal space between 7^th and 8^th rib. We also observed improper development of carpals, metacarpals, tarsals, and metatarsals of the Group 5 fetuses.Conclusion:Guaifenesin showed a significant developmental toxicity at selected test doses; therefore, a careful use is suggested during pregnancy.KEY WORDS: Developmental toxicity, embryotoxicity, fetotoxicity, guaifenesin, teratogen, toxicology     

Early expression of mature αβ TCR in CD4−CD8− T cell progenitors enables MHC to drive development of T-ALL bearing NOTCH mutations

During normal T cell development in mouse and human, a low-frequency population of immature CD4⁻CD8⁻ double-negative (DN) thymocytes expresses early, mature αβ T cell antigen receptor (TCR). We report that these early αβ TCR+ DN (EADN) cells are DN3b-DN4 stage and require CD3δ but not major histocompatibility complex (MHC) for their generation/detection. When MHC - is present, however, EADN cells can respond to it, displaying a degree of coreceptor-independent MHC reactivity not typical of mature, conventional αβ T cells. We found these data to be connected with observations that EADN cells were susceptible to T cell acute lymphoblastic leukemia (T-ALL) transformation in both humans and mice. Using the OT-1 TCR transgenic system to model EADN-stage αβ TCR expression, we found that EADN leukemogenesis required MHC to induce development of T-ALL bearing NOTCH1 mutations. This leukemia-driving MHC requirement could be lost, however, upon passaging the tumors in vivo, even when matching MHC was continuously present in recipient animals and on the tumor cells themselves. These data demonstrate that MHC:TCR signaling can be required to initiate a cancer phenotype from an understudied developmental state that appears to be represented in the mouse and human disease spectrum.

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy arising from transformed immature T cell precursors (1). It represents ∼15% of pediatric and ∼25% of adult ALLs (2). Identification of subgroups with varied biological features, including overall relapse risk and responses to standard therapies, has allowed stratification of patients to the most appropriate therapeutic regimens that maximize efficacy, and has led to generally improved survival. However, prognosis remains poor for patients with treatment-refractory primary disease or relapse (3, 4). Clinical T-ALL can show inter- and intrapatient heterogeneity in the differentiation stage of tumor cells, implying that multiple pathways of cancer development exist (1, 5). Despite the heterogeneity, a unifying oncogenic network hub required for most or all T-ALL in humans and mice is hyperactivated (often mutated) NOTCH (6). Among the best understood causal drivers is developmentally early CD3 signaling at the pre-T cell antigen receptor (TCR)/γδTCR lineage bifurcation checkpoint, without a role for major histocompatibility complex (MHC)-based ligand (7–9). In contrast, a requirement for MHC and mature αβTCR to drive thymic leukemogenesis, resulting in mutant NOTCH-bearing tumors, has not been previously demonstrated.This makes sense based on the known relationship between T-ALL and T cell development. While there is overlap in NOTCH and developmentally early CD3 signals, cessation of NOTCH prior to MHC-restricted positive/negative selection signals mediated by αβTCR largely prevents simultaneous activity of the two receptors. Most conventional thymocytes rearrange first TCRβ and later TCRα loci in separate, ordered developmental stages. NOTCH signaling is required for early CD4⁻CD8⁻ double negative (DN) thymocyte development (10) while rearrangement of TCRβ and pre-TCR expression mediate β-selection, clonal expansion, and advancement to CD4⁺CD8⁺ double-positive (DP) stage (11). NOTCH signaling is then turned off (12), while DP thymocytes rearrange TCRα, express mature αβTCR, and test self-peptide-MHC reactivity in positive/negative selection (13).However, outside of this well-described sequence of events, a low-frequency, natural subset of DN thymocytes was once shown to rearrange and prematurely express the full αβTCR in wild-type mice (14). The cells were first detected in pre-Tα^−/− mice, where early TCRα replaced pre-Tα to provide β-selection signaling to generate DP cells. Conventional αβ T cell development potential was retained as proven in positive selection assays, but subsequent to the initial report little information on biological roles for these cells has followed. While pursuing developmental stages and signals in T-ALL leukemogenesis, we found that early αβTCR-expressing DN (EADN) cells can be generated in mouse and human thymus at a similar rate, and they are susceptible to T-ALL transformation in both species. We present a mouse model in which EADN oncogenesis requires MHC to drive development of T-ALL bearing NOTCH-mutations, highlighting a novel developmental state with unique signaling rules for a cancer phenotype that appears to be represented in the clinical, human disease spectrum.     

IgM monoclonal gammopathies of clinical significance: diagnosis and management

IgM monoclonal gammopathy of undetermined significance is a pre-malignant condition for Waldenström macroglobulinemia and other B-cell malignancies, defined by asymptomatic circulating IgM monoclonal protein below 30 g/L with a lymphoplasmacytic bone marrow infiltration of less than 10%. A significant proportion, however, develop unique immunological and biochemical manifestations related to the monoclonal protein itself in the absence of overt malignancy and are termed IgM-related disorders or, more recently, monoclonal gammopathy of clinical significance. The indication for treatment in affected patients is dictated by the pathological characteristics of the circulating IgM rather than the tumor itself. The clinical workup and treatment options vary widely and differ from those for Waldenström macroglobulinemia. The aim of this review is to alert clinicians to IgM monoclonal gammopathy of clinical significance and to provide practical guidance on when to screen for these phenotypes. We discuss clinical characteristics, the underlying clonal profile, diagnostic workup and treatment considerations for five important subtypes: cold agglutinin disease, type I and II cryoglobulinemia, IgM-associated peripheral neuropathy, Schnitzler syndrome and IgM-associated AL amyloidosis. The inhibition of the pathogenic effects of the IgM has led to great success in cold agglutinin disease and Schnitzler syndrome, whereas the other treatments are centered on eradicating the underlying clone. Treatment approaches in cryoglobulinemia and IgM-associated peripheral neuropathy are the least well developed. A multidisciplinary approach is required, particularly for IgM-related neuropathies and Schnitzler syndrome. Future work exploring novel, clone-directed agents and pathogenic IgM-directed therapies is welcomed.     

Prevention and management of secondary central nervous system lymphoma

Secondary central nervous system (CNS) lymphoma (SCNSL) is defined by the involvement of the CNS, either at the time of initial diagnosis of systemic lymphoma or in the setting of relapse, and can be either isolated or with synchronous systemic disease. The risk of CNS involvement in patients with diffuse large B-cell lymphoma is approximately 5%; however, certain clinical and biological features have been associated with a risk of up to 15%. There has been growing interest in improving the definition of patients at increased risk of CNS relapse, as well as identifying effective prophylactic strategies to prevent it. SCNSL often occurs within months of the initial diagnosis of lymphoma, suggesting the presence of occult disease at diagnosis in many cases. The differing presentations of SCNSL create the therapeutic challenge of controlling both the systemic disease and the CNS disease, which uniquely requires agents that penetrate the blood-brain barrier. Outcomes are generally poor with a median overall survival of approximately 6 months in retrospective series, particularly in those patients presenting with SCNSL after prior therapy. Prospective studies of intensive chemotherapy regimens containing high-dose methotrexate, followed by hematopoietic stem cell transplantation have shown the most favorable outcomes, especially for patients receiving thiotepa-based conditioning regimens. However, a proportion of patients will not respond to induction therapies or will subsequently relapse, indicating the need for more effective treatment strategies. In this review we focus on the identification of high-risk patients, prophylactic strategies and recent treatment approaches for SCNSL. The incorporation of novel agents in immunochemotherapy deserves further study in prospective trials.     

Does Insurance Effect the Outcome in Patients With Acute Coronary Syndrome?: An Insight from the Most Recent National Inpatient Sample

Several studies have shown disparities in outcome in the patients with Acute coronary syndrome (ACS) based on several factors. Treatment might differ based on insurance type. Therefore, we retrospectively analyzed National Inpatient Sample (NIS 2016) data to identify the impact of different types of insurances on mortality outcome in patients admitted with ACS. ICD-CM-10 codes were used to identify hospital discharges with a principal diagnosis of ACS. Observations were stratified based on insurance (Medicare, Medicaid, Private, and No insurance). Primary and secondary outcomes were in-hospital mortality, length of stay and total cost. Any potential confounders were adjusted using multivariate logistic regression. STATA/IC 15.1 Stata Corp LLC was used for analysis. A total of 8,01,195 hospitalizations with the primary diagnosis of ACS were identified, of which 59.2% had Medicare, 9.72% had Medicaid, 26.8% had Private insurance, and 4.3% had no insurance. Higher odds of mortality were seen in the patients with Medicare, Medicaid, and Noninsured group. Adjusted Odds ratio for mortality in Medicare was 1.01 (confidence interval [CI]: 0.94-1.1; P = 0.65), in Medicaid was 1.16 (CI: 1.03-1.30; P = 0.01) and in uninsured group was 1.46 (CI: 1.26-1.69; P ≤ 0.01). However, the patients with private insurance adjusted odds ratio for mortality were 0.77 (CI: 0.70-0.84; P ≤ 0.01) compared to the patients with other insurance groups. Above results show that the disparity exists in the outcome of patients admitted with ACS based on their insurance types, particularly for Medicaid patients. We need further studies to understand the root cause of this disparity.     

The Rory Morrison WMUK Registry for Waldenström macroglobulinaemia: The growth of a national registry for a rare disorder

National registries are used globally to characterise patient demographics, treatment choices and mortality to inform and improve clinical management. Waldenström macroglobulinaemia (WM) is a rare, treatment-responsive B-cell lymphoproliferative disorder with diverse clinical features and variable outcomes. To prospectively chart changes in the management of WM in the UK, the Rory Morrison Registry (RMR) was developed to systematically collect real-world data. Here we describe the development of the RMR, demonstrate its feasibility and describe preliminary observations. The RMR was devised as a collaborative project between patients and clinicians, under the auspices of the UK Charity for WM in 2016. Patients may be registered after the point of diagnosis and those with historic diagnosis were also eligible. Data collection fields were compiled by focus groups of clinicians, patients, industry and commissioning partners. The RMR launched in November 2017 and as of March 2022, there were 22 participating centres and 1305 patients registered. Median follow-up was 6.4 years, five-year overall survival 90.7% (95% confidence interval [CI] 88.4%–92.5%) and 10-year overall survival 79.3% (95% CI 75.7%–82.4%). There has been a clear evolution in treatments including a rapid growth in the use of Bruton's tyrosine kinase inhibitors in relapsed disease since their availability in the UK.