Experience with the JMS fully automated dialysis machine

A fully automated dialysis machine has been developed and evaluated clinically. It uses highly pure dialysate (produced by a new dialysate cleaning system) instead of the conventional physiologic saline for the processes of priming, guiding blood to the dialysis machine, replenishing fluid, and returning the blood to the body. The piping for the dialysate is in the shape of a loop, and the dialyzer coupler has no mechanical parts that might become contaminated. As a result of these and certain other improvements in machine design, it is now possible to obtain reasonably clean dialysate. For the priming process, the machine uses a volume of up to 4 L of the dialysate after reverse filtration from the dialyzer. Most foreign matter or eluates can be removed from the dialyzer and the blood channels. Before blood is guided out of the body into the dialysis system, the needles inserted in the artery and vein are simultaneously connected to the blood channel, and the dialysate remaining in the channel is removed from the dialyzer. If the patient's blood pressure falls during dialysis, the dialysate can be replenished at any desired flow rate for reverse filtration. Blood return can be started automatically when the planned dialysis time has elapsed and the target water volume has been removed. The cleaned dialysate is infused from the dialyzer into the blood channel by reverse filtration to allow the blood to be returned to the body via both the artery and the vein at the same time. A total of 216 units of this fully automated dialysis machine have been placed in service at two of our facilities. During the 6 month period beginning in July 2001, they were used for 40,000 hemodialysis sessions in 516 patients. During the dialysate preparation process, the endotoxin levels in the reverse osmosis (RO) water, prefilter dialysate, and reverse filtered dialysate were all less than 1 EU/L. The time required to guide blood into the dialyzer (n = 39) decreased from the 4.6 +/- 1.4 minutes with the conventional machines to 3.2 +/- 0.6 minutes with the new machine (p < 0.01). The time required to return blood to the body also decreased from 8.6 +/- 2.2 minutes with the conventional machines to 6.8 +/- 0.7 minutes with the new machine (n = 34). No mechanical trouble was encountered with the fully automated dialysis machine units during the 40,000 hemodialysis sessions, and the workload of the dialysis unit staff in terms of the time needed to guide out and return blood to the body was significantly reduced. Because the machine simplifies the maneuvers required during hemodialysis, it is expected to contribute greatly to preventing medical accidents and in hospital infections associated with hemodialysis.     

Estimated number of off‐target candidate sites for antisense oligonucleotides in human mRNA sequences

Antisense oligonucleotide (ASO) therapeutics are single‐stranded oligonucleotides which bind to RNA through sequence‐specific Watson–Crick base pairings. A unique mechanism of toxicity for ASOs is hybridization‐dependent off‐target effects that can potentially occur due to the binding of ASOs to complementary regions of unintended RNAs. To reduce the off‐target effects of ASOs, it would be useful to know the approximate number of complementary regions of ASOs, or off‐target candidate sites of ASOs, of a given oligonucleotide length and complementarity with their target RNAs. However, the theoretical number of complementary regions with mismatches has not been reported to date. In this study, we estimated the general number of complementary regions of ASOs with mismatches in human mRNA sequences by mathematical calculation and in silico analysis using several thousand hypothetical ASOs. By comparing the theoretical number of complementary regions estimated by mathematical calculation to the actual number obtained by in silico analysis, we found that the number of complementary regions of ASOs could be broadly estimated by the theoretical number calculated mathematically. Our analysis showed that the number of complementary regions increases dramatically as the number of tolerated mismatches increases, highlighting the need for expression analysis of such genes to assess the safety of ASOs.     

Childhood ADHD is strongly associated with a broad range of psychiatric disorders during adolescence: a population-based birth cohort study

Background: To evaluate associations between attention‐deficit/hyperactivity disorder (ADHD) and comorbid psychiatric disorders using research‐identified incident cases of ADHD and population‐based controls. Methods: Subjects included a birth cohort of all children born 1976–1982 remaining in Rochester, MN after age five (n = 5,718). Among them we identified 379 ADHD incident cases and 758 age‐gender matched non‐ADHD controls, passively followed to age 19 years. All psychiatric diagnoses were identified and abstracted, but only those confirmed by qualified medical professionals were included in the analysis. For each psychiatric disorder, cumulative incidence rates for subjects with and without ADHD were estimated using the Kaplan–Meier method. Corresponding hazard ratios (HR) were estimated using Cox models adjusted for gender and mother’s age and education at the subject’s birth. The association between ADHD and the likelihood of having an internalizing or externalizing disorder was summarized by estimating odds ratios (OR). Results: Attention‐deficit/hyperactivity disorder was associated with a significantly increased risk of adjustment disorders (HR = 3.88), conduct/oppositional defiant disorder (HR = 9.54), mood disorders (HR = 3.67), anxiety disorders (HR = 2.94), tic disorders (HR = 6.53), eating disorders (HR = 5.68), personality disorders (HR = 5.80), and substance‐related disorders (HR = 4.03). When psychiatric comorbidities were classified on the internalization‐externalization dimension, ADHD was strongly associated with coexisting internalizing/externalizing (OR = 10.6), or externalizing‐only (OR = 10.0) disorders. Conclusion: This population‐based study confirms that children with ADHD are at significantly increased risk for a wide range of psychiatric disorders. Besides treating the ADHD, clinicians should identify and provide appropriate treatment for psychiatric comorbidities.     

Induction of protumoral CD11chigh macrophages by glioma cancer stem cells through GM‐CSF

Cancer stem cells (CSCs) are maintained under special microenvironment called niche, and elucidation and targeting of the CSC niche will be a feasible strategy for cancer eradication. Tumor‐associated macrophages (TAMs) are known to be involved in cancer progression and thus can be a component of CSC niche. Although TAMs are known to play multiple roles in tumor progression, involvement of CSCs in TAM development fully remains to be elucidated. Using rat C6 glioma side population (SP) cells as a model of glioma CSCs, we here show that CSCs induce the TAM development by promoting survival and differentiation of bone marrow‐derived monocytes. CSC‐induced macrophages can be separated into two distinct subsets of cells, CD11c^low and CD11c^high cells. Interestingly, only the CD11c^high subset of cells have protumoral activity, as shown by intracranial transplantation into immune‐deficient mice together with CSCs. These CD11c^high macrophages were observed in the tumor formed by co‐transplantation with CSCs. Furthermore, CSCs produced GM‐CSF and anti‐GM‐CSF antibody inhibited CSC‐induced TAM development. In conclusion, CSCs have the ability to self‐create their own niche involving TAMs through CSC‐derived GM‐CSF, which can thus be a therapeutic target in view of CSC niche disruption.     

Selection of appropriate antimicrobial agents to test and report by clinical microbiology laboratories

Clinical microbiology laboratories in Japan have not yet established standards for selecting the most appropriate antimicrobial agents for testing and reporting antimicrobial susceptibility that are comparable to the performance standards of the National Committee for Clinical Laboratory Standards(NCCLS) in the United States of America. Selection of the most appropriate antimicrobial agents for testing and reporting was discussed by a working group(WG) consisting of medical physicians, surgeons, pharmacists, medical technologists and medical microbiologists. The WG agreed on the following basic criteria for the selection of antimicrobial agents: 1) the agent should be useful when screening various resistant bacteria, 2) the agent should serve as a useful guide for physicians and residents when selecting antimicrobial agents, and 3) the agent should be useful for controlling nosocomial infections and resistant bacteria. Clinically isolated microorganisms were classified into 7 groups based on susceptibility to antimicrobial agents. These groups were Staphylococcus spp. or Enterococcus spp., Streptococcus spp. or Haemophilus spp., enterobacteriae, glucose non-fermenting gram positive rods(NFRs), anaerobic bacteria, fungi and mycobacterium. After considering clinical and bacteriological evidence, the WG decided on several antimicrobial agents for testing in clinical microbiology laboratories in Jichi Medical School Hospital. For the NFR group, these were Piperacillin(PIPC), ceftazidime(CAZ), cefepime, imipenem, amikacin and levofloxacin(LVFX). For the enterobacteriae group, these were Amplicillin(ABPC), PIPC, aztreonam, CAZ and LVFX. For the Staphylococcus spp. or Enterococcus spp. group, these were oxacillin, ABPC, vancomycin and gentamicin. We concluded that the most appropriate antimicrobial agent for testing and reporting must be economical and agreed upon at the hospital level, although the ultimate selection must be based on the available clinical and bacteriological evidence.     

Revisited univariate delta check method for hematologic laboratories (I)--Usefulness for detection of specimen mix-up in patients with hematologic disorders

We evaluated the delta check method for hematologic laboratories to detect specimen mix-up. We selected 271 patients with hematologic disorders and two types of investigation were conducted. The first investigation comprised statistical analysis, while the second involved evaluation of the procedure. From parameters of white blood cell, red blood cell, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin(MCH), mean corpuscular hemoglobin concentration (MCHC), and platelets, MCV was considered to represent the best single marker to detect artificial mix-up. About 98% of MCV delta values from one patient were within 3 fl. Conversely, 40% of MCV delta values in artificial mixups exceed 10 fl. No correlations between time interval and MCV delta values were detected. However, some cases were observed in which MCV delta values changed markedly over a short period of time even though the samples originated from one patient. In conclusion, we recommend investigation for specimen mix-up in cases where MCV delta values exceed 4 fl.     

Association analysis of an (AC)n repeat polymorphism in the GABA(B) receptor gene and schizophrenia

The human gamma-aminobutyric acid type B (GABA(B)) receptor gene is a candidate gene for schizophrenia due to its chromosomal location and neurobiologic roles. In the present study, association analyses of genetic polymorphisms of the GABA(B) receptor gene with schizophrenia were carried out in 102 unrelated schizophrenic patients and 100 healthy controls, using a polymerase chain reaction-based, single-strand conformational polymorphism analysis. Although the Ala20Val and Gly489Ser mutations were not found in our samples, we found a novel polymorphism of (AC)n dinucleotide repeats located approximately 1.6 kb upstream from the translational start site. No significant difference in allele frequencies was found between controls and patients with schizophrenia (P = 0.0587) using the Monte Carlo method. Significant differences were found between controls and patients with continuous-course schizophrenia (P = 0.0019), and between controls and patients with a positive family history of psychoses (P = 0.0015). These differences, however, were not significant after Bonferroni correction. These data did not support our hypothesis that polymorphisms of the GABA(B) receptor gene may confer vulnerability for schizophrenia.