Dissolved Organic Matter Processing in Pristine Antarctic Streams

Accelerated glacier melt and runoff may lead to inputs of labile dissolved organic matter (DOM) to downstream ecosystems and stimulate the associated biogeochemical processes. However, still little is known about glacial DOM composition and its downstream processing before entering the ocean, although the function of DOM in food webs and ecosystems largely depends on its composition. Here, we employ a set of molecular and optical techniques (UV–vis absorption and fluorescence spectroscopy, 1H NMR, and ultrahigh-resolution mass spectrometry) to elucidate the composition of DOM in Antarctic glacial streams and its downstream change. Glacial DOM consisted largely of a mixture of small microbial-derived biomolecules. 1H NMR analysis of bulk water revealed that these small molecules were processed downstream into more complex, structurally unrecognizable molecules. The extent of processing varied between streams. By applying multivariate statistical (compositional data) analysis of the DOM molecular data, we identified molecular compounds that were tightly associated and moved in parallel in the glacial streams. Lakes in the middle of the flow paths enhanced water residence time and allowed for both more DOM processing and production. In conclusion, downstream processing of glacial DOM is substantial in Antarctica and affects the amounts of biologically labile substrates that enter the ocean

Resolution and Resurgence of Schistosoma haematobium—induced Pathology After Community-based Chemotherapy in Ghana, as Detected by Ultrasound

Community-based treatment is recommended for endemic populations with urinary schistosomiasis; however, the optimal target group for treatment and retreatment interval have not been established. Using ultrasound, this study identified subpopulations whose lesions were most likely to respond to treatment and characterized resurgence of pathology. Ultrasound examination of 1202 infected patients was followed by chemotherapy with praziquantel. A sample of 698 patients was followed for 18 months after treatment. Nearly all types of bladder pathologies resolved after treatment, regardless of patient's age or intensity of initial infection. However, many patients' upper urinary tract pathologies (62.5%) did not resolve. During the 18-month follow-up period, reappearance of severe bladder pathologies was rare, and < 10% of persons had resurgence of mild bladder pathologies. For this population, re-treatment is not needed annually but might be cost effective if given several years later. Confirmation from other areas is required before general policies can be forme

Post-Cataract Surgery Visual Disturbance in a Retinitis Pigmentosa Patient with Asteroid Hyalosis

A patient with retinitis pigmentosa showed visual disturbances following successful cataract surgery. He had a dense asteroid hyalosis in the eye before cataract surgery. After the surgery he noticed that his vision became worse. The visual disturbance was explained as being caused by the progression of retinal degeneration. Although the electroretinogram was non-recordable, the degeneration of macular area appeared relatively small. We considered that dense asteroid hyalosis was responsible for his visual disturbances, and pars plana vitrectomy (PPV) was performed to remove the asteroid hyalosis. After the PPV, rapid improvement of his visual acuity was observed. Cataract surgery may affect the status of asteroid hyalosis and cause rapid visual loss. PPV should be considered for retinitis pigmentosa patients with dense asteroid hyalosis, especially when a large decrease in visual acuity is noted shortly after cataract surgery

Outer retinal circular structures in patients with Bietti crystalline retinopathy.

[Background] : Bietti crystalline retinopathy (BCR) is a distinct retinal degenerative disease characterised by retinal degeneration with many yellow–white crystals located mainly at the posterior pole area. Using spectral domain-optical coherence tomography (SD-OCT), the structural change in retina was investigated. [Methods] : Patients diagnosed with BCR (n=12), retinitis pigmentosa (RP, n=292) and cone dystrophy (n=16) were included in this study. The authors mainly examined fundus photographs and SD-OCT, infrared and fundus autofluorescence images of these patients. [Results]: Crystalline deposits were detected in portions of the retinal pigment epithelium that lacked patchy degenerated lesions. SD-OCT revealed that most of the observed crystalline deposits were located adjacent to the inner side of retinal pigment epithelium layer. The change most frequently observed was circular hyper-refractive structures in the outer nuclear layer. Although the structures were considered to be previously reported “tubular formation” or “tubular degeneration”, we determined that many of these circular structures were slices of spherical structures and were typically noted in areas suspected of ongoing active degeneration. [Conclusion] : BCR has characteristic structures in the outer nuclear layer. Although the incidence of the structure varies, it may be characteristic of retinal degeneration and can be found in many retinal degenerative diseases

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of a human condensin SMC2 hinge domain with short coiled coils

Kawahara, K., Nakamura, S., Katsu, Y., Motooka, D., Hosokawa, Y., Kojima, Y., Matsukawa, K., Takinowaki, H., Uchiyama, S., Kobayashi, Y., Fukui, K. & Ohkubo, T. (2010). Acta Cryst. F66, 1067-1070

Decreased ADP-Ribosyl Cyclase Activity in Peripheral Blood Mononuclear Cells from Diabetic Patients with Nephropathy

Aims/hypothesis. ADP-ribosyl-cyclase activity (ADPRCA) of CD38 and other ectoenzymes mainly generate cyclic adenosine 5’diphosphate-(ADP-) ribose (cADPR) as a second messenger in various mammalian cells, including pancreatic beta cells and peripheral blood mononuclear cells (PBMCs). Since PBMCs contribute to the pathogenesis of diabetic nephropathy, ADPRCA of PBMCs could serve as a clinical prognostic marker for diabetic nephropathy. This study aimed to investigate the connection between ADPRCA in PBMCs and diabetic complications. Methods. PBMCs from 60 diabetic patients (10 for type 1 and 50 for type 2) and 15 nondiabetic controls were fluorometrically measured for ADPRCA based on the conversion of nicotinamide guanine dinucleotide (NGD+) into cyclic GDP-ribose. Results. ADPRCA negatively correlated with the level of HbA1c (P = .040, R2 = .073), although ADPRCA showed no significant correlation with gender, age, BMI, blood pressure, level of fasting plasma glucose and lipid levels, as well as type, duration, or medication of diabetes. Interestingly, patients with nephropathy, but not other complications, presented significantly lower ADPRCA than those without nephropathy (P = .0198) and diabetes (P = .0332). ANCOVA analysis adjusted for HbA1c showed no significant correlation between ADPRCA and nephropathy. However, logistic regression analyses revealed that determinants for nephropathy were systolic blood pressure and ADPRCA, not HbA1c. Conclusion/interpretation. Decreased ADPRCA significantly correlated with diabetic nephropathy. ADPRCA in PBMCs would be an important marker associated with diabetic nephropathy

Structural basis for dimer formation of human condensin structural maintenance of chromosome proteins and its implications for single-stranded DNA recognition

Eukaryotic structural maintenance of chromosome proteins (SMC) are major components of cohesin and condensins that regulate chromosome structure and dynamics during cell cycle. We here determine the crystal structure of human condensin SMC hinge heterodimer with ∼30 residues of coiled coils. The structure, in conjunction with the hydrogen exchange mass spectrometry analyses, revealed the structural basis for the specific heterodimer formation of eukaryotic SMC and that the coiled coils from two different hinges protrude in the same direction, providing a unique binding surface conducive for binding to single-stranded DNA. The characteristic hydrogen exchange profiles of peptides constituted regions especially across the hinge-hinge dimerization interface, further suggesting the structural alterations upon single-stranded DNA binding and the presence of a half-opened state of hinge heterodimer. This structural change potentially relates to the DNA loading mechanism of SMC, in which the hinge domain functions as an entrance gate as previously proposed for cohesin. Our results, however, indicated that this is not the case for condensins based on the fact that the coiled coils are still interacting with each other, even when DNA binding induces structural changes in the hinge region, suggesting the functional differences of SMC hinge domain between condensins and cohesin in DNA recognition.Susumu Uchiyama, Kazuki Kawahara, Yuki Hosokawa, Shunsuke Fukakusa, Hiroya Oki, Shota Nakamura, Yukiko Kojima, Masanori Noda, Rie Takino, Yuya Miyahara, Takahiro Maruno, Yuji Kobayashi, Tadayasu Ohkubo, Kiichi Fukui. Structural Basis for Dimer Formation of Human Condensin Structural Maintenance of Chromosome Proteins and Its Implications for Single-stranded DNA Recognition. Journal of Biological Chemistry, Volume 290, Issue 49, 2015, Pages 29461-29477. https://doi.org/10.1074/jbc.M115.670794

Development of early neutropenic fever, with or without bacterial infection, is still a significant complication after reduced-intensity stem cell transplantation

AbstractLittle information is available on the clinical characteristics of infectious complications that occur in the early period after reduced-intensity stem cell transplantation (RIST). We retrospectively investigated the clinical features of neutropenic fever and infectious episodes within 30 days after RIST in 76 patients who had received fluoroquinolones as part of their antibacterial prophylaxis. Preparative regimens included cladribine 0.66 mg/kg or fludarabine 180 mg/m2 plus busulfan 8 mg/kg. All but 1 patient survived 30 days after transplantation, and 75 patients (99%) became neutropenic within a median duration of 9 days. Neutropenic fever was observed in 29 patients (38%), and bacterial infection was confirmed in 15 (20%) of these, including bacteremia (n = 13), bacteremia plus pneumonia (n = 1), and urinary tract infection (n = 1). The causative organisms were gram-positive (n = 9) and gram-negative organisms (n = 7), with a mortality rate of 6%. Neither viral nor fungal infection was documented. Multivariate analysis showed that the presence of neutropenia at the initiation of preparative regimens was an independent risk factor for subsequent documented bacterial infections (P = .026; 95% confidence interval, 1.25–35.1). We conclude that neutropenic fever and bacteremia remain common complications in RIST