Progressive hearing loss and vestibular dysfunction caused by a homozygous nonsense mutation in CLIC5

In a consanguineous Turkish family diagnosed with autosomal recessive nonsyndromic hearing impairment (arNSHI), a homozygous region of 47.4 Mb was shared by the two affected siblings on chromosome 6p21.1-q15. This region contains 247 genes including the known deafness gene MYO6. No pathogenic variants were found in MYO6, neither with sequence analysis of the coding region and splice sites nor with mRNA analysis. Subsequent candidate gene evaluation revealed CLIC5 as an excellent candidate gene. The orthologous mouse gene is mutated in the jitterbug mutant that exhibits progressive hearing impairment and vestibular dysfunction. Mutation analysis of CLIC5 revealed a homozygous nonsense mutation c.96T>A (p.(Cys32Ter)) that segregated with the hearing loss. Further analysis of CLIC5 in 213 arNSHI patients from mostly Dutch and Spanish origin did not reveal any additional pathogenic variants. CLIC5 mutations are thus not a common cause of arNSHI in these populations. The hearing loss in the present family had an onset in early childhood and progressed from mild to severe or even profound before the second decade. Impaired hearing is accompanied by vestibular areflexia and in one of the patients with mild renal dysfunction. Although we demonstrate that CLIC5 is expressed in many other human tissues, no additional symptoms were observed in these patients. In conclusion, our results show that CLIC5 is a novel arNSHI gene involved in progressive hearing impairment, vestibular and possibly mild renal dysfunction in a family of Turkish origin.     

Arterial Stiffness as a Predictor of Clinical Hypertension

The association between vascular stiffening and blood pressure is likely bidirectional. The present study was designed to examine temporal relationships among vascular stiffness, blood pressure progression, and hypertension. The Asymptomatic Polyvascular Abnormalities Community study is a community‐based, prospective, long‐term follow‐up observational study. The present investigation is based on the baseline examinations (2010–2011) and the first follow‐up measurements (2012–2013) included in the study. A total of 4025 participants were followed for an average of 27 months. Of 2153 participants free of hypertension at the baseline examination, 432 (20.07%) had incident hypertension. The authors observed that brachial‐ankle pulse wave velocity (baPWV) was an independent predictor of incident hypertension. baPWV during baseline examination was positively associated with higher systolic blood pressure, diastolic blood pressure, pulse pressure, and mean arterial pressure during the first follow‐up examination. baPWV but not blood pressure during baseline examination was associated with baPWV during the first follow‐up examination. This study not only provides evidence that baPWV is an independent predictor of blood pressure progression and incident hypertension, but also provides evidence that blood pressure is not associated with baPWV after adjusting for baseline baPWV.     

Evidence favoring lineage fidelity in acute nonlymphocytic leukemia: absence of immunoglobulin gene rearrangements in FAB types M4 and M5

The concept of lineage fidelity in acute leukemia has recently been challenged by the finding of rearrangements of the immunoglobulin heavy chain genes in a leukemic cell line and in a small number of sporadic cases of acute nonlymphocytic leukemia with a monocytic phenotype. We therefore screened leukemic blood or bone marrow samples of 33 adult patients with acute nonlymphocytic leukemia of FAB types M4 (23 patients) and M5 (10 patients); 28 were obtained at diagnosis and 5 at relapse. All cases were well characterized pathologically and histochemically. Cytogenetic analysis performed in each case demonstrated karyotypes that were representative of those generally seen in these types of leukemia, with a clonal abnormality present in all except 9 of 32 patients who were successfully studied. DNA prepared from each sample was digested with the restriction enzyme BamH1 and analyzed by Southern blot hybridization to probes for the JH region of the immunoglobulin heavy chain. All 33 cases had DNA retained in the germline configuration with no evidence of rearrangement. This finding supports the concept of lineage fidelity, and suggests that true interlineage infidelity, myeloid to lymphoid, is a rare occurrence in adult acute nonlymphocytic leukemia.     

Phenotypic characterization of gamma interferon-induced human monocyte polykaryons

Multinucleated giant cells of mononuclear phagocyte origin (monocyte or macrophage polykaryons [MPs] ) are seen in numerous different normal and pathologic states. We have previously shown that gamma interferon (IFN-gamma) induces fusion of uninuclear monocytes (UMs) to form MPs. This study was designed to characterize these IFN-gamma-induced MPs. Control and IFN-gamma-treated UMs and MPs did not have peroxidase activity, but they stained intensely for nonspecific esterase and acid phosphatase. The esterase of UMs and MPs was abolished by fluoride, but the acid phosphatase of UMs and MPs was only minimally decreased by tartrate. The phagocytosis of polystyrene spheres and glutaraldehyde- fixed erythrocytes by MPs was moderately depressed as compared with control or treated UMs, whereas the phagocytosis of IgG-coated erythrocytes was markedly depressed. Populations of control monocytes produced less H2O2 in response to 200 nmol/L of phorbol myristate acetate than did IFN-gamma-treated monocytes (37 +/- 7 v 199 +/- 29 nmol/h per milligram of cell protein). However, when examined microscopically, individual MPs had less ability to reduce NBT (18% +/- 5% positive for MP, 91% +/- 3% for treated UMs, and 67% +/- 3% for control UMs). The surface membrane antigens Leu M3, OKM1 (C3bi receptor), DU-HL60-3, DU-HL60-4, TE5, and V1 were not expressed or were expressed poorly in MPs; they were expressed normally in control and treated UMs. However, HLA-DR expression was increased in treated UMs and MPs. The binding of the lectins RCA, Con A, WGA, DBA, UEA, and PNA was equivalent in all cells. Thus, MPs formed by fusion of UMs in vitro after culture with IFN-gamma differ in several features from UMs.     

Combination chemotherapy of adult acute lymphoblastic leukemia with randomized central nervous system prophylaxis

Although major progress has been made in the treatment of childhood leukemia, the optimal chemotherapy of acute lymphoblastic leukemia (ALL) in adults has been unclear. In addition, the value of central nervous system prophylaxis (CNS-P) in adults has been assumed, but not established in a systematic fashion. The Southeastern Cancer Study Group has completed a prospective study in which the use of vincristine plus low-dose methotrexate and high-dose prednisone in adult acute lymphoblastic leukemia has produced an 80% (79/99) complete remission rate in patients age 15 yr and over. Younger patients had a significantly higher remission rate but no increase in remission duration. This induction regimen was associated with minimal toxicity. Random assignment to CNS-P or to no prophylaxis, after a multidrug consolidation regimen, has demonstrated a significant prolongation of CNS relapse-free interval (p=0.008) in favor of CNS-P. CNS-P did not improve hematologic remission duration or survival. All complete remitters were maintained on mercaptopurine, methotrexate, and cyclophosphamide with pulses of prednisone and vincristine; the median time from remission to either hematologic or CNS relapse was 19.3 mo after CNS-P, and survival for these patients was 26.1 mo. We conclude that our current induction regimen is highly effective in adult ALL and that CNS-P prophylaxis is indicated in such patients.     

Echo-tracking evaluation of changes in common carotid artery wall elasticity after smoking cessation

The aim of this study was to explore changes in the common carotid arterial wall elasticity after smoking cessation. Carotid artery ultrasonographic examination was performed in 136 patients, then 1 or 2 years after smoking cessation. We used echo-tracking (ET) to measure stiffness index (β), pressure-strain elasticity modulus (Ep), arterial compliance (AC), augmentation index (AI), and local pulse wave velocity (PWVβ). Patients were divided into four groups based on whether or not they successfully stopped smoking (groups M and N, respectively) and whether (groups M2 and N2, respectively) or not (groups M1 and N1, respectively) they showed comorbidities. In group M1, β, Ep and PWVβ were lower at 1 year than before smoking cessation, while AC and AI did not change. At 2 years, β, Ep, PWVβ, and AC, but not AI, improved further. In group M2, β, Ep, and PWVβ decreased at 2 years, whereas AC and AI did not change. In groups N1 and N2, none of the variables changed significantly. ET can be used quantitatively to evaluate the impact of smoking cessation on the elasticity of the common carotid artery wall.     

The neonatal immune response to washed and irradiated red cells: lack of evidence of lymphocyte activation

A total of 21 neonatal infants (11 males and 10 females) were evaluated for lymphocyte subpopulation changes and cellular activation following the receipt of washed and gamma-irradiated red cells. The mean donor exposure was 2 +/- 1.5 donors, and the mean white cell concentration of each 10-mL-per-kg transfusion was 2 x 10(7) cells. A total of 2800 rad (28 Gy) was delivered to each red cell unit prior to washing. The lymphocyte subsets CD3+, CD4+, CD8+, CD19+, CD3+/CD25+, CD3+/HLA-DR, CD4+/CD45RA, CD4+/CDw29, and CD4+/ICHL-1 were analyzed, as were plasma gamma-interferon and neopterin levels, before and after blood transfusion. Posttransfusion samples were obtained from 3 to 12 days after the last blood transfusion. There were no posttransfusion changes in the percentage of lymphocyte subsets analyzed. Furthermore, overlay-histogram analysis of pretransfusion and posttransfusion CD45RA-, CDw29-, and UCHL-1-positive helper T cells failed to reveal a shift in mean channel fluorescence intensity, which is indicative of a lack of cellular activation. Gamma-interferon levels remained unchanged after transfusion (range, 90 +/- 5.9 to 95.5 +/- 5.3 pg/mL), as did neopterin levels (range, 3.7 +/- 1.5 to 4.6 +/- 1.5 ng/mL). This study could not find any evidence, by either cellular or humoral markers, of the activation of neonatal lymphocytes by transfusion. It is hypothesized that this failure to observe lymphocyte activation is due to the low number of donor white cells present in washed, irradiated red cells and/or to a lack of recipient recognition of transfused, allogeneic, donor white cells.