Size control of sol-gel-synthesized ZnO quantum dots using photo-induced desorption.

We developed a sol-gel method using photo-induced desorption for size-controlled ZnO quantum dots (QDs). This method successfully controlled the size and size variance of ZnO QDs, and size fluctuations decreased from 23% to 18% depending on the illuminated light intensity. The sol-gel synthesis effectively reduced the number of defect levels that originated from oxygen defects.

Transmission of cytomegalovirus via breast milk in extremely premature infants.

OBJECTIVE: We prospectively evaluated the rate of postnatal cytomegalovirus (CMV) transmission through breast milk in extremely premature infants to address the impact of CMV infection on preterm infants during lactation. STUDY DESIGN: A total of 25 mothers and 27 infants (two sets of twins) with birth weights <1000 g and/or gestational ages <28 weeks were enrolled in the study. They were mostly fed frozen-thawed breast milk. Breast milk, serum and urine samples were collected every 2 weeks and screened for CMV infection using the real-time polymerase chain reaction. RESULT: All of the 21 CMV-seropositive mothers had detectable CMV DNA in their breast milk, with a peak at 4 to 6 weeks postpartum. CMV infection was confirmed in only one infant (4.3%) who displayed almost no clinical symptoms. CONCLUSION: At our institutes, we mainly use frozen-thawed breast milk. We found low CMV transmission rates even in extremely premature infants, and the CMV-positive infant did not develop serious symptoms.

The effect of ascorbate on minor recurrent aphthous stomatitis.

AIM: Minor recurrent aphthous stomatitis (MRAS) is a common, painful and inflammatory ailment of the oral cavity with juvenile onset and unknown aetiology. The purpose of this study was to evaluate the potential of ascorbate (vitamin C) to reduce the frequency of MRAS and severity of pain. PATIENTS AND METHODS: Sixteen MRAS patients (9 boys and 7 girls: mean age, 12.0 +/- 2.4 years old) were assigned to take an oral dosage of 2000 mg/m(2)/day ascorbate. SUBJECTS: Their baseline frequency of outbreaks and the level of pains were compared during the treatment; in addition, a crossover clinical trial was performed. Polymorphonuclear leucocytes play a role in the pathogenesis, and then superoxide anion production was evaluated in prior to ascorbate treatment. RESULTS: The data indicated a statistically significant 50% reduction in oral ulcer outbreaks and a decline of pain level. Neutrophils were primed for superoxide anion production in the patients with MRAS. CONCLUSION: Ascorbate may modulate the generation of reactive oxygen species and augment neutrophil apoptosis, which could prevent neutrophil-mediated inflammation. Ascorbate seems to be effective, but the findings of our study were preliminary and it should be re-evaluated with a larger randomized controlled clinical trials.

Thalidomide prevents formation of multinucleated giant cells (Langhans-type cells) from cultured monocytes: possible pharmaceutical applications for granulomatous disorders.

Thalidomide is an effective drug for chronic inflammatory diseases, but the mechanism underlying its immunomodulatory action remains uncertain. Thalidomide has been reported to clinically improve chronic inflammatory granulomatous disorders. In such disorders, the granulomas consist of epithelioid cells, scattered lymphocytes and multinucleated giant cells (MNGC; Langhans-type cells). The present experimental approach permitted the reproduction of MNGC formation from peripheral blood monocytes and examination of thalidomides effect on it. MNGC can be effectively generated from monocytes cultured in the presence of interleukin-4 (IL-4) and macrophage colony-stimulating factor(M-CSF) for 14 days. Thalidomide can inhibit the formation of MNGC in a dose-dependent manner. MNGC formation was partly inhibited by the presence of neutralizing TNF-alpha antibody in the responses induced by IL-4 and M-CSF. Autocrinal TNF-alpha production and modulation of cadhelin expression to regulate cell adhesion might be involved in this inhibitory action of thalidomide. Our results support thalidomides clinical efficacy in the treatment of chronic granulomatous disorders (granulomatosis).

Multi-nucleated giant cell formation from human cord blood monocytes in vitro, in comparison with adult peripheral blood monocytes.

Multi-nucleated giant cells (MGCs; Langhans-type cell), formed from macrophage fusion, are recognized as a hallmark histological feature in chronic inflammation. However, their precise pathological role is still poorly understood, especially for microorganism pathogens in the neonatal immune system, which are capable of surviving intracellularly in phagocytes. To conduct a partial evaluation of the monocyte function of neonates, we investigated the ability of human cord blood monocytes to form MGCs in vitro by stimulating various cytokines and comparing them with adult peripheral blood monocytes. Monocytes from cord blood and adult peripheral blood were isolated and cultured for 14 days with cytokines known to induce MGC in vitro. The fusion index in experiments with a combination of interleukin (IL)-4 and macrophage colony-stimulating factor (M-CSF) and a combination of IL-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly lower in cord blood than in adult blood monocytes (P = 0.0018 and P = 0.0141, respectively). The number of nuclei per MGC was significantly lower in cord blood than in adult blood monocytes in experiments with IL-4 alone, the combination of IL-4 and M-CSF, and the combination of IL-4 and GM-CSF (P < 0.0001). These results suggest the possibility that the susceptibility of newborns to mycobacterium infection is due partly to impaired MGC formation.

Differences of clinical manifestations according to the patterns of brain lesions in acute encephalopathy with reduced diffusion in the bilateral hemispheres.

BACKGROUND AND PURPOSE: The precise clinical characteristics of acute encephalopathy with bilateral reduced diffusion are not fully understood. We compared clinical, laboratory, and neuroimaging findings according to the patterns of brain lesions among children with reduced diffusion in the bilateral hemispheres. MATERIALS AND METHODS: Nine patients were analyzed. The patterns of brain lesions were divided into diffuse lesions and central-sparing lesions. Diffuse lesions were defined as reduced diffusion in the whole cortex and/or subcortical white matter. Central-sparing lesions were defined as the lack of reduced diffusion in the areas around the bilateral Sylvian fissures. Clinical, laboratory, and neuroimaging findings were compared between groups. RESULTS: Five patients showed diffuse lesions and 4 showed central-sparing lesions. Coma was significantly more common in patients with diffuse lesions, whereas a biphasic clinical course was more common in those with central-sparing lesions. Outcome was worse in patients with diffuse lesions. Maximal aspartate aminotransferase, alanine aminotransferase, and kinase levels were also significantly higher in patients with diffuse lesions. In 2 patients with diffuse lesions, diffusion-weighted images during the acute phase revealed reduced diffusion in the bilateral frontal and occipital areas, followed by diffuse lesions. No patient with central-sparing lesions showed MR imaging abnormalities during the acute phase. CONCLUSIONS: Clinical manifestations in patients with diffuse lesions were severe, whereas those in patients with central-sparing lesions were relatively mild.

Theophylline inhibits the differentiation of human monocyte into dendritic cell potentially via adenosine receptor antagonism.

BACKGROUND: Theophylline has an anti-inflammatory action that may account for its clinical effectiveness in the reduction of inflammatory cells in the airways. Dendritic cells (DCs) are professional antigen-presenting cells, capable of priming naïve T cells, and play key roles in the activation of immune responses in asthma. OBJECTIVE: The purpose of this study was to investigate the effects of theophylline on human monocyte differentiation into DCs and whether this involved antagonism of adenosine receptors. METHODS: Peripheral human blood monocytes were cultured in the presence of granulocyte/macrophage-colony stimulating factor and IL-4 to induce DC differentiation. The cells were incubated with theophylline, KF17837 (a selective A2a receptor antagonist) and enprofylline (A2b receptor antagonist) and co-incubated with selective adenosine A1 and A2a receptor agonists, a phosphodiesterase inhibitor (rolipram) and adenosine deaminase (ADA) to determine their effects on DC differentiation. In addition, depletion of adenosine receptors by small interfering RNA (siRNA) was also examined. RESULTS: Monocytes differentiated into myeloid DCs in the culture system. The number of DCs was remarkably reduced by 60-70% when theophylline was administered at a therapeutic concentration. This effect was concentration-dependently exacerbated, was partly mediated by cellular apoptosis and was effectively reversed by the addition of the A1 agonists [2-chloro-N(6)-cyclopentyladenosin, N(6)-cyclohexyladenosine, and N-ethylcarboxamidoadenosine (NECA)] or the A2a agonist (CGS-21680, NECA). The depletion of the adenosine A1 receptor by siRNA and addition of ADA remarkably reduced DC differentiation. Meanwhile, both enprofylline and rolipram had little effect. CONCLUSION: Our findings suggest that the adenosine A1 (and possibly coordinated with A2a) receptors contribute to DC differentiation and survival. These findings provide further evidence that theophylline has an anti-inflammatory action in bronchial asthma.

Relationship between oral mucositis and high-dose methotrexate therapy in pediatric acute lymphoblastic leukemia.

OBJECTIVE: Oral mucositis is a major toxicity in the high-dose methotrexate (HD-MTX) treatment for children with acute lymphoblastic leukemia (ALL). The first aim of this study was to evaluate the relationship between the MTX serum concentration and occurrence of oral mucositis in pediatric ALL patients. The second aim was to clarify the relationship between MTX exposure and epidermal keratinocyte cell injury using an in vitro study. METHODS: 49 patients were treated according to the Japan Association of Childhood Leukemia Study (JACLS) ALL-HR02 protocol. This protocol involves HD-MTX treatment (3 g/m2 for 24-h i.v. infusion). The MTX serum concentrations were measured by a fluorescence polarization immunoassay. The relationship between oral mucositis and MTX serum concentrations 48 and 72 h after administration was determined. The cell toxicity of MTX for human epidermal keratinocytes was analyzed by using a cell viability assay (WST-1 assay). In addition, pharmacokinetic evaluation for clearance, AUC extrapolated from 48 h to infinity (AUC48h-inf) and elimination half-life (t1/2b) were done using the 1-compartmental models. RESULTS: Oral mucositis occurred in 24 patients (49.0%), in whom 20 patients (83.3% in oral mucositis group) showed WHO severity Grade 1 or 2. Only 4 patients (16.7% in oral mucositis group) showed Grade 3 severity. 22 patients (44.9%) had oral mucositis in the group with a concentration under 10-6 M 48 h after MTX administration. There was no significant deference among the cell viabilities in the concentrations of 10-6 M, 10-5 M and 10-4 M 48 h after the MTX exposure. However, the cell viability obtained 24 h after the MTX exposure was significantly different from the respective cell viability 48, 72 and 96 h after the MTX exposure. In the group with oral mucositis, the clearance decreased significantly (p = 0.042), and the t1/2b (p = 0.025) and AUC48h- yen (p = 0.025) increased significantly compared with the non-symptom group. CONCLUSIONS: It seems that there is no significant relationship between the serum MTX concentration and oral mucositis. This in vitro study has demonstrated that the cell injury was related to the duration of MTX exposure rather than a high MTX concentration.

The mildest form of acute necrotizing encephalopathy associated with influenza A.

We experienced the mildest form of acute necrotizing encephalopathy associated with influenza A. A previously healthy 13-year-old girl had mildly decreased consciousness and delirious behavior lasting for a week. Diffusion-weighted imaging showed mildly high signal intensities in the bilateral thalami, deep white matter in the centrum semiovale, and frontal lobes. Conventional T (1)- or T (2)-weighted images revealed no abnormalities.

Evaluation of combination therapy using aciclovir and corticosteroid in adult patients with herpes simplex virus encephalitis.

OBJECTIVE: Herpes simplex virus encephalitis (HSVE) is associated with significant morbidity and mortality, even with appropriate antiviral therapy. In the present investigation, the first to assess efficacy of corticosteroid treatment with aciclovir therapy in HSVE, multiple logistic regression analysis was performed of predictors of outcome in adult patients with HSVE. METHODS: A non-randomised retrospective study of 45 patients with HSVE treated with aciclovir was conducted. The patients were divided into poor and good groups based on outcome at three months after completion of aciclovir treatment. The variables evaluated were: clinical variables (sex, age, days after onset at initiation of aciclovir, Glasgow Coma Scale (GCS) at initiation of aciclovir, initial and maximum values for the cell numbers and protein concentration in the cerebrospinal fluid, and corticosteroid administration); neuroradiological variables (detection of lesions by initial cranial computed tomography and by initial magnetic resonance imaging); and one neurophysiological variable (detection of periodic lateralised epileptiform discharges on the initial electroencephalogram). Single variable logistic regression analysis was performed followed by multiple logistic regression analysis. The best set of predictors for the outcome of HSVE was estimated by stepwise logistic regression analysis. RESULTS: A poor outcome was evident with older age, lower GCS score at initiation of aciclovir, and no administration of corticosteroid. Patient age, GCS at initiation of aciclovir, and corticosteroid administration were found to be significant independent predictors of outcome on multiple logistic regression analysis, and these three variables also formed the best set of predictors (R(2) = 0.594, p<0.0001). CONCLUSION: Combination therapy using both aciclovir and corticosteroid represents one of the predictors of outcome in HSVE.

Relapse of neonatal herpes simplex virus infection.

BACKGROUND: Neonatal herpes simplex virus (HSV) infection is a severe disease with high mortality and morbidity. Recurrence of skin vesicles is common. OBJECTIVE: To determine the features of relapse and identify the factors related to relapse. DESIGN: Thirty two surviving patients with neonatal herpes virus infections were enrolled. All patients received acyclovir treatment. Clinical and virological data were analysed and compared between relapsed and non-relapsed cases. RESULTS: Thirteen (41%) had either local skin or central nervous system relapse between 4 and 63 days after completing the initial antiviral treatment. Nine patients exhibited local skin relapses, and four developed central nervous system relapses. In one skin and two central nervous system relapse cases, neurological impairment later developed. Type 2 virus infection was significantly related to relapse (odds ratio 10.4, 95% confidence interval 1.1 to 99.0). Patients with relapse had worse outcomes than those without relapse. CONCLUSION: Neonates with HSV type 2 infections have a greater risk of relapse. Relapsed patients have poorer prognoses.

NOx (nitrite/nitrate) in cerebral spinal fluids obtained from patients with influenza-associated encephalopathy.

It has become evident that the number of patients with a new type of influenza-associated encephalopathy is increasing in Japan. Nitric oxide (NO), a simple free radical gas, elicits a wide range of physiological and pathophysiological effects. We measured the nitrite/nitrate (NO x ) levels in cerebral spinal fluid obtained from patients with influenza-associated encephalopathy in order to evaluate the correlation between the NO production and the process of influenza-associated encephalopathy. Fifteen children were enrolled, aged from 1 to 9 years. As control we used 14 cerebral spinal fluids obtained from patients with urinary tract infection, respiratory infection or mumps meningitis without any sequela. NO 3 in influenza-associated encephalopathy was significantly higher than that of control group. On the other hand NO 2 was not significantly higher than that of control group. In particular, 4 out of 5 fatal cases revealed high NO 2 or NO 3. One case having normal levels in NO 2 and NO 3 showed that NH 3 was high. These results revealed that NO plays a role in influenza-associated encephalopathy through indirect effects of NO.

Varicella exposure in a neonatal medical centre: successful prophylaxis with oral acyclovir.

In December 2000, a female infant hospitalized in our Neonatal Care Centre was infected with varicella by her mother. Although prophylactic intravenous acyclovir was administered at a dose of 15 mg/kg daily, she later developed varicella during her hospital stay. We therefore initiated control procedures to prevent further hospital-acquired infections. Oral acyclovir (40 mg/kg daily divided into four doses) was administered prophylactically to six preterm infants in contact with the varicella patient. None of six preterm infants subsequently developed clinical varicella or had any adverse effects associated with acyclovir administration. It is suggested that prophylactic administration of oral acyclovir (40 mg/kg daily) might prevent hospital-acquired varicella-zoster virus (VZV) infections, and that oral acyclovir may be an option for VZV prophylaxis in situations where VZV immunoglobulin is not available.

Expression of tegument protein pp65 of human cytomegalovirus (CMV) and its application to the analysis of viral-specific cellular immunity in CMV-infected individuals.

Investigations into human cytomegalovirus (CMV)-specific cellular immunity are important to better understand and manage CMV infections. CMV phosphoprotein pp65 is thought to be a major antigen for CMV-specific cellular immunity. We newly synthesized protein pp65 with a baculovirus expression system and purified it via metal affinity chromatography in a soluble form. The recombinant protein pp65 was antigenic in an enzyme immuno-linked assay for pp65-specific IgG in sera from 196 children. Traditional lymphoproliferation assays have shown that pp65 protein promotes specific lymphoproliferation in CMV-seropositive donors. Using an intracellular cytokine detection system, we showed that this recombinant protein stimulated CD4-positive T cells to express interferon-gamma. The results of these assays using protein pp65 were comparable with the use of CMV whole antigen. pp65- and CMV-specific cellular immunity, and CMV DNA load were also compared in four recipients of unrelated cord blood transplantation. The delay in re-constitution in CMV-specific cellular immunity was associated with reactivation of CMV. These results indicated that the recombinant protein pp65 can be used to study specific immunity in CMV infections.

Natural killer cell proliferation and circulating cytokines in patients with bilateral basal ganglia calcification.

Ten adult patients with symmetrical calcifications in the bilateral basal ganglia (diagnosed as physiological calcifications) were analyzed for lymphocyte subsets and cytokines. Increased number of natural killer (NK) cells were identified in the peripheral blood of seven patients by lymphocyte subset analysis. Tumor necrosis factor-alpha was detected in the sera of five patients and interferon-gamma was detected in one patient. In summary, NK cell propagation and circulating cytokines, particularly tumor necrosis factor-alpha, may be involved in the etiology of basal ganglia calcification.

Prospective monitoring of the Epstein-Barr virus DNA by a real-time quantitative polymerase chain reaction after allogenic stem cell transplantation.

Epstein-Barr virus (EBV)-related lymphoproliferative disorder (LPD) is a serious complication of haematopoietic stem cell transplantation (HSCT). To clarify the frequency, natural course and risk factors for LPD, we prospectively monitored 38 allogeneic (allo)-HSCT patients, focusing on the use of anti-thymocyte globulin (ATG). We used a recently developed real-time polymerase chain reaction assay to monitor EBV genome load. The subjects consisted of 19 patients given ATG for conditioning and 19 patients not given ATG. Of the 19 patients given ATG, 47.4% (nine patients) had a significant increase in EBV genome load (10(2.5) copies/microg DNA). Of these nine patients, two developed LPD. Therefore, 10.5% of the patients receiving allo-HSCT with ATG developed LPD. In contrast, none of the 19 patients without ATG had a significantly increased EBV load. The increases in viral load were observed in the second or third month after HSCT. We found that the peak viral loads of LPD patients were > 10(4.0 ) copies/microg DNA. On the other hand, the viral loads of most patients with no symptoms were < 10(2.5) copies/microg DNA. In conclusion, routine monitoring of EBV load during the second and third months after transplantation may benefit patients undergoing HSCT with ATG. We propose that an EBV load > 10(2.5) copies/microg DNA is the reactivation of EBV, and that an EBV load > 10(4.0) copies/microg DNA is indicative of developing LPD.

[Prognostic significance of myocardial imaging with iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid in patients with angina pectoris].

OBJECTIVES: To assess the clinical significance of iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid(BMIPP) single photon emission computed tomography(SPECT), the predictive value of BMIPP imaging in patients with angina pectoris was evaluated. METHODS: One hundred seventy-four patients who underwent BMIPP imaging in our institution were aged 61.8 +/- 11 years. One hundred thirty-five patients had stable angina and 39 had unstable angina at the time of examination. Patients with previous myocardial infarction or myocardial disorders were excluded. Early and delayed images were acquired in BMIPP SPECT, and the images were analyzed visually. Cardiac events were classified into hard and soft events: the former consisted of cardiac death and nonfatal myocardial infarction, and the latter included coronary revascularization and heart failure. RESULTS: The findings of BMIPP imaging were normal in 82 patients and abnormal in 92. During follow-up of 15.5 +/- 9.5 months, hard events were observed in 4 patients and soft events in 53. In patients with normal BMIPP imaging, soft events were observed in nine patients, but no hard event was encountered. Furthermore, in patients with both normal BMIPP and stress thallium imagings, no cardiac event was observed during 2 years. In contrast, 4 hard events and 44 soft events occurred in patients with abnormal BMIPP imaging. Patients with abnormal BMIPP imaging had a higher incidence of soft events than those with normal BMIPP imaging, regardless of the type of angina(16/62 vs 3/73, p < 0.0005 for stable angina; 28/30 vs 6/9, p < 0.0001 for unstable angina). CONCLUSIONS: The finding of BMIPP imaging correlates well with the mid-term prognosis of patients with angina pectoris. Since BMIPP SPECT is performed without stress to the patient, this imaging modality is important in evaluating patients with stable or unstable angina.

Diagnostic testing in Epstein-Barr virus infection.

Laboratory diagnosis of Epstein-Barr virus (EBV) infection is improving with the development of new technologies. Quantification of the virus by real-time polymerase chain reaction (PCR) and evaluation of EBV-specific T cells, especially by tetrameric human leukocyte antigens, are noteworthy candidates for monitoring procedures in clinical laboratories involved in the management of transplant recipients. Standardization of PCR is essential for improving the quality of these monitoring procedures.

Bullous amyloidosis: the mechanism of blister formation revealed by electron microscopy.

BACKGROUND: Few electron microscopic studies of blister lesions in bullous amyloidosis have been reported, and the mechanism of blister formation remains to be elucidated. This study was designed to examine the nature of bullous amyloidosis ultrastructurally, and clarify the pathogenesis of blister formation. METHODS: We examined a 47-year-old woman with IgD-lambda type myeloma, suffering from bullous lesions on her hands and feet caused by trauma or rubbing. Light and electron microscopic studies were performed. RESULT: Ultrastructurally, amyloid deposits aggregated under the lamina densa. Keratinocyte protrusions penetrated the dermis through the gap in the lamina densa and enfolded amyloid deposits. Amyloid globules were found in enlarged intercellular spaces of keratinocytes. Desmosomes were sparsely distributed in some areas of the epidermis. CONCLUSION: These results indicate that keratinocytes enfold the amyloid globules and take them in the intercellular space of epidermis, and that the breakdown of the lamina densa and widening of the intercellular space between keratinocytes induce skin fragility. Trauma or rubbing of her hands and feet appears to act as the localized precipitating factor of blister formation in bullous amyloidosis.