A truncating PET100 variant causing fatal infantile lactic acidosis and isolated cytochrome c oxidase deficiency

Isolated mitochondrial complex IV (cytochrome c oxidase) deficiency is an important cause of mitochondrial disease in children and adults. It is genetically heterogeneous, given that both mtDNA-encoded and nuclear-encoded gene products contribute to structural components and assembly factors. Pathogenic variants within these proteins are associated with clinical variability ranging from isolated organ involvement to multisystem disease presentations. Defects in more than 10 complex IV assembly factors have been described including a recent Lebanese founder mutation in PET100 in patients presenting with Leigh syndrome. We report the clinical and molecular investigation of a patient with a fatal, neonatal-onset isolated complex IV deficiency associated with multiorgan involvement born to consanguineous, first-cousin British Asian parents. Exome sequencing revealed a homozygous truncating variant (c.142C>T, p.(Gln48*)) in the PET100 gene that results in a complete loss of enzyme activity and assembly of the holocomplex. Our report confirms PET100 mutation as an important cause of isolated complex IV deficiency outside of the Lebanese population, extending the phenotypic spectrum associated with abnormalities within this gene.     

Monocytoid B-cell lymphoma: its evolution and relationship to other low- grade B-cell neoplasms

Monocytoid B-cell lymphoma (MBCL) is a newly recognized B-cell neoplasm of uncertain histogenesis. The cytologic features of the neoplastic monocytoid B lymphocytes are virtually identical to those of hairy cell leukemia (HCL). As with HCL, progression of MBCL to a higher histologic grade is very unusual. However, whereas circulating leukemic cells are a characteristic feature of HCL, peripheral blood involvement has not been reported in MBCL. We recently studied a patient with MBCL of the spleen and axillary lymph nodes who developed peripheral blood involvement by MBCL cells. Unlike the cells of HCL, the circulating MBCL cells exhibited strong acid phosphatase activity that was tartrate sensitive. The leukemic cells had the antigenic phenotype IgM lambda, CD20+, CD11c+, CD5-, CD25(TAC)-, and PCA-1-. Immunogenetic studies of both lymph node and peripheral blood cells revealed identical immunoglobulin heavy-chain gene rearrangements. When compared with a series of HCL, the immunophenotype was similar except for the absence of PCA-1 and TAC. Progression of the MBCL to a large cell lymphoma, also expressing IgM lambda, was documented in an abdominal lymph node of this patient. Therefore, although rare, peripheral blood involvement by lymphoma cells may occur during the course of MBCL and should be distinguished from HCL with cytochemical and immunophenotypic studies. In addition, comparison of the clinical, pathologic, and immunologic features of MBCL with those of other low-grade B-cell neoplasms suggests that a close lineage relationship exists between MBCL and HCL.     

Treatment with interleukin-3 plus granulocyte-macrophage colony- stimulating factors improves the selectivity of Ara-C in vitro against acute myeloid leukemia blasts

Hematopoietic growth factors (HGFs) interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) individually have been shown to increase the percentage of acute myeloid leukemia (AML) blasts in S phase and enhance the cytotoxic effects of Ara-C against these blasts in culture. We compared in vitro the effects of a combined treatment with GM-CSF (10 ng/mL) plus IL-3 (10 ng/mL) on the metabolism and cytotoxicity of Ara-C in normal bone marrow mononuclear cells (NBMMC) and AML blasts. NBMMC from six healthy volunteers and AML blasts from 10 patients were incubated for 20 hours with or without IL- 3 plus GM-CSF, followed by a concurrent treatment with Ara-C for 4 additional hours. Exposure to the HGFs and Ara-C produced significantly higher intracellular Ara-CTP levels as well as higher Ara-CTP/dCTP pool ratios in AML blasts as compared with NBMMC. Treatment with HGFs resulted in [3H] Ara-C DNA incorporation that was significantly higher in AML blasts versus NBMMC. This selective improvement of Ara-C metabolism in AML blasts was associated with an enhanced Ara-C-mediated leukemia colony-forming unit (CFU) growth inhibition. In contrast, exposure to HGFs resulted in an improved colony growth of normal CFU granulocyte-monocyte and CFU-granulocyte, erythroid, monocyte, megakaryocyte. These in vitro studies indicate that a combined treatment with IL-3 plus GM-CSF may improve the selectivity of Ara-C against AML blasts.     

Glutamine Improves Innate Immunity and Prevents Bacterial Enteroinvasion During Parenteral Nutrition

Background: Patients receiving parenteral nutrition (PN) are at increased risk of infectious complications compared with enteral feeding, which is in part explained by impaired mucosal immune function during PN. Adding glutamine (GLN) to PN has improved outcome in some clinical patient groups. Although GLN improves acquired mucosal immunity, its effect on innate mucosal immunity (defensins, mucus, lysozymes) has not been investigated. Methods: Forty‐eight hours following venous cannulation, male Institute of Cancer Research mice were randomized to chow (n = 10), PN (n = 12), or PN + GLN (n = 13) for 5 days. Small intestine tissue and luminal fluid were collected for mucin 2 (MUC2), lysozyme, cryptdin 4 analysis, and luminal interleukin (IL)–4, IL‐10, and IL‐13 level measurement. Tissue was also harvested for ex vivo intestinal segment culture to assess tissue susceptibility to enteroinvasive Escherichia coli. Results: In both luminal and tissue samples, PN reduced MUC2 and lysozyme (P < .0001, respectively) compared with chow, whereas GLN addition increased MUC2 and lysozyme (luminal, P < .05; tissue, P < .0001, respectively) compared with PN alone. PN significantly suppressed cryptdin 4 expression, while GLN supplementation significantly enhanced expression. IL‐4, IL‐10, and IL‐13 decreased significantly with PN compared with chow, whereas GLN significantly increased these cytokines compared with PN. Functionally, bacterial invasion increased with PN compared with chow (P < .05), while GLN significantly decreased enteroinvasion to chow levels (P < .05). Conclusions: GLN‐supplemented PN improves innate immunity and resistance to bacterial mucosal invasion lost with PN alone. This work confirms a clinical rationale for providing glutamine for the protection of the intestinal mucosa.     

West Nile Virus Infection Incidence Based on Donated Blood Samples and Neuroinvasive Disease Reports,Northern Texas,USA, 2012

During the 2012 outbreak of West Nile virus in the United States, approximately one third of the cases were in Texas. Of those, about half occurred in northern Texas. Models based on infected blood donors and persons with neuroinvasive disease showed, respectively, that ≈0.72% and 1.98% of persons in northern Texas became infected.     

Donor sex,age and ethnicity impact stored red blood cell antioxidant metabolism through mechanisms in part explained by glucose 6-phosphate dehydrogenase levels and activity

Red blood cell (RBC) storage in the blood bank promotes the progressive accumulation of metabolic alterations that may ultimately impact the erythrocyte capacity to cope with oxidant stressors. However, the metabolic underpinnings of the capacity of RBC to resist oxidant stress and the potential impact of donor biology on this phenotype are not known. Within the framework of the REDS-III RBC-Omics study, RBC from 8,502 healthy blood donors were stored for 42 days and tested for their propensity to hemolyse following oxidant stress. A subset of extreme hemolysers donated a second unit of blood, which was stored for 10, 23, and 42 days and profiled again for oxidative hemolysis and metabolomics (599 samples). Alterations of RBC energy and redox homeostasis were noted in donors with high oxidative hemolysis. RBC from females, donors over 60 years old, donors of Asian/South Asian race-ethnicity, and RBC stored in additive solution- 3 were each independently characterized by improved antioxidant metabolism compared to, respectively, males, donors under 30 years old, Hispanic and African American race ethnicity donors, and RBC stored in additive solution-1. Merging metabolomics data with results from an independent genome-wide association study on the same cohort, we identified metabolic markers of hemolysis and glucose 6-phosphate dehydrogenasedeficiency, which were associated with extremes in oxidative hemolysis and dysregulation in nicotinamide adenine dinucleotide phosphate and glutathione- dependent detoxification pathways of oxidized lipids. Donor sex, age, ethnicity, additive solution and glucose 6-phosphate dehydrogenase status impact the metabolism of the stored erythrocyte and its susceptibility to hemolysis following oxidative insults.     

Monoclonal autoantibody from a (New Zealand black x New Zealand white)F1 mouse and some human scleroderma sera target an Mr 34,000 nucleolar protein of the U3 RNP particle

A monoclonal IgG2a antinucleolar autoantibody (72B9) was obtained by fusion of spleen cells from a (New Zealand black x New Zealand white)F1 mouse with myeloma cells (P3x63Ag8.653). Antibody 72B9 recognized a highly conserved nucleolar antigen present in both animal and plant cells. The staining pattern produced by antibody 72B9 in different cell substrates was identical with those obtained by scleroderma antibodies reactive with a basic (pI 8.5) nucleolar protein of Mr 34,000, which is associated with the U3 RNP particle. Western blotting further confirmed its reactivity with this scleroderma-related U3 RNP protein.     

Surgical treatment of piles

PURPOSE: The present prospective, randomized clinical trial compares the outcome of surgical hemorrhoidectomy according to Parks and Milligan-Morgan in terms of hospital stay, duration of incapacity to work, symptom relief, length of morbidity, and patient convenience. METHODS: Thirty-four consecutive patients with third or fourth degree internal hemorrhoids were randomly allocated to the two groups. Before surgery, all patients were interviewed using a standard questionnaire, followed by rectal examination. All patients underwent a follow-up interview and examinations 1, 2, 4, 8, and 12 weeks after the operation. RESULTS: No serious postoperative complications were seen. Length of hospital stay (3.2 days for Parks hemorrhoidectomyvs. 4.6 days for Milligan-Morgan hemorrhoidectomy; 95 percent confidence interval, 0.2 and 2.6, respectively;P=0.02) and mean duration of incapacity to work (12.3 days for Parks hemorrhoidectomyvs. 20.2 days for Milligan-Morgan hemorrhoidectomy; 95 percent confidence interval, 5.7 and 10.2, respectively;P<0.001) differed significantly between the Milligan-Morgan and Parks patients. Until two weeks after the operation, Milligan-Morgan hemorrhoidectomy patients experienced significantly more pain. CONCLUSIONS: Our study confirms that both operations are safe, easy to perform, and lead to satisfactory results. However, the Parks procedure is the preferred option, because it minimizes patients' postoperative discomfort, is more economic, has a significantly reduced hospital stay, and has a shorter time for return to work.