Biomedical subjects

Katsunori Aoki

Publications and source records attributed to Katsunori Aoki.

12 recordsLinked to original sources

PubMed2004

Clinical significance of peripheral blood erythroblastosis after hematopoietic stem cell transplantation.

Erythroblasts (EBL) are normally not observed in peripheral blood, but may be found in patients suffering from a variety of severe diseases. The detection of EBL in peripheral blood has been shown to be associated with a poor prognosis. However, the clinical significance of peripheral erythroblastosis after hematopoietic stem cell transplantation (HSCT) has not been evaluated. We retrospectively analyzed the records of 161 patients who underwent HSCT at our hospital from June 1995 to October 2001. EBL at any level were detected in 94% of the patients. Forty-four and 11 patients experienced erythroblastosis exceeding 200 and 1,000/ul, respectively. The erythroblast count was higher in patients who died than in the survivors (geometric mean value 184 vs. 100/ul, P=0.01). High-level erythroblastosis ( >1,000/ul) within 180 days after HSCT was associated with an extremely poor prognosis (median survival 22.5 days). Among the possible confounding factors, the use of total body irradiation (RR 2.35, 95% CI 1.22 - 4.54, P=0.011) and the disease status before transplantation (RR 2.51, 95% CI 1.15 - 5.49, P=0.021) were independent significant factors for erythroblastosis after HSCT. As for post-transplant events, a high EBL concentration was frequently preceded by graft-vs.-host disease, thrombotic microangiopathy, hypoxia, and hematological relapse.

Adult↗

PubMed2004

Prospective comparison of the diagnostic potential of real-time PCR, double-sandwich enzyme-linked immunosorbent assay for galactomannan, and a (1-->3)-beta-D-glucan test in weekly screening for invasive aspergillosis in patients with hematological disorders.

The establishment of an optimal noninvasive method for diagnosing invasive aspergillosis (IA) is needed to improve the management of this life-threatening infection in patients with hematological disorders, and a number of noninvasive tests for IA that target different fungal components, including galactomannan, (1-->3)-beta-d-glucan (BDG), and Aspergillus DNA, have been developed. In this study, we prospectively evaluated the diagnostic potential of three noninvasive tests for IA that were used in a weekly screening strategy: the double-sandwich enzyme-linked immunosorbent assay (ELISA) for galactomannan (Platelia Aspergillus), a real-time PCR assay for Aspergillus DNA (GeniQ-Asper), and an assay for BDG (beta-glucan Wako). We analyzed 149 consecutive treatment episodes in 96 patients with hematological disorders who were at high risk for IA and diagnosed 9 proven IA cases, 2 probable IA cases, and 13 possible invasive fugal infections. In a receiver-operating characteristic (ROC) analysis, the area under the ROC curve was greatest for ELISA, using two consecutive positive results (0.97; P = 0.036 for ELISA versus PCR, P = 0.055 for ELISA versus BDG). Based on the ROC curve, the cutoff for the ELISA could be reduced to an optical density index (O.D.I.) of 0.6. With the use of this cutoff for ELISA and cutoffs for PCR and BDG that give a comparable level of specificity, the sensitivity/specificity/positive predictive value/negative predictive value of the ELISA and the PCR and BDG tests were 1.00/0.93/0.55/1.00, 0.55/0.93/0.40/0.96, and 0.55/0.93/0.40/0.96, respectively. In conclusion, among these weekly screening tests for IA, the double-sandwich ELISA test was the most sensitive at predicting the diagnosis of IA in high-risk patients with hematological disorders, using a reduced cutoff of 0.6 O.D.I.

Adolescent↗

PubMed2003

Rapid diagnosis of invasive pulmonary aspergillosis by quantitative polymerase chain reaction using bronchial lavage fluid.

Polymerase chain reaction (PCR) is a sensitive method for detection of Aspergillus DNA in bronchoalveolar lavage fluid, but it has not yet been able to distinguish infection from contamination. We have established a technique to quantify Aspergillus DNA using a real-time PCR method to resolve this problem, and we report herein a successful application of real-time PCR to diagnose invasive pulmonary aspergillosis by comparing the amount of Aspergillus DNA in bronchial lavage fluid from an affected area to that from an unaffected area. This novel tool will provide rapid, sensitive, and specific diagnosis of pulmonary aspergillosis.

Adult↗

PubMed2003

Reduced-intensity bone marrow transplantation from an alternative unrelated donor for myelodysplastic syndrome of first-donor origin.

A male patient had a relapse of myelodysplastic syndrome (MDS) 2 years after BMT from a female matched unrelated donor. Conventional cytogenetics, FISH, and short-tandem repeat chimerism analysis proved a relapse of donor origin. He underwent reduced-intensity BMT after a conditioning with fludarabine and busulfan, since he had impaired renal, liver, and pulmonary functions. Chimerism analysis on day 28 after the second BMT showed mixed chimerism of the first and the second donors, which later turned to full second-donor chimerism on day 60. He developed grade II acute GVHD of the skin and cytomegalovirus reactivation, but both were improved with methylprednisolone and ganciclovir, respectively. He remains in complete remission 6 months after the second BMT. Reduced-intensity second BMT from an alternative donor appeared to be a tolerable treatment option for donor-derived leukemia/MDS after the first conventional transplantation.

Adult↗

PubMed2003

Ischemic colitis as a manifestation of thrombotic microangiopathy following bone marrow transplantation.

Thrombotic microangiopathy (TMA) is a microvascular disorder characterized by platelet aggregation and hemolytic anemia. In the setting of bone marrow transplantation (BMT), ischemic colitis due to TMA is difficult to differentiate from acute graft-versus-host disease. We report a 32-year-old man who presented ischemic colitis due to TMA after unrelated BMT for myelodysplastic syndrome. He suffered from treatment-resistant bloody diarrhea, and died of renal failure and Aspergillus pleuritis on day 253 post-BMT. Autopsy revealed endothelial injuries of arterioles and ischemic changes in the intestines and kidneys. Clinical and pathological characteristics of ischemic colitis due to BMT-associated TMA are described.

Adult↗

PubMed2003

[Neuroendocrine response to critical illness and nutritional pharmacology].

Injury and infection produce significant alterations in metabolic homeostasis. Host humoral factors, such as the counterregulatory hormones epinephrine, cortisol, and glucagons, play important roles in metabolic changes postinjury. Hyperglycemia associated with insulin resistance is common in critically ill patients, even those who have an uneventful course postinjury. The use of exogenous insulin to maintain blood glucose at a level no higher than 110 mg per deciliter, known as intensive insulin therapy, has reduced morbidity and mortality among critically ill patients. Glucocorticoids and various proinflammatory cytokines are important regulators of muscle proteolysis in stressed patients. With regard to nutritional support, enteral feeding is superior to parenteral feeding and early feeding is better than late feeding. Immune-enhancing diets has been shown in several recent studies to improve outcome in critically ill patients. Moreover, various hormones, including insulin, growth hormone, and insulin-like growth factor-1, may blunt muscle cachexia. Other treatments including cytokine antibodies, induction of heat-shock protein, and calcium antagonists, may prevent the catabolic response to stress, and these methods are important considering the significant clinical consequences of protein catabolism.

Critical Illness↗

PubMed2002

A role for the octameric ring protein, Translin, in mitotic cell division.

The octameric ring protein, Translin, demonstrates marked similarities to the family of helicase enzymes regarding its quaternary organization and dimerization of subunits. Here we show that the level of Translin closely parallels the proliferative state in various cell types. Expression is periodic during the cell cycle, with protein synthesis becoming maximal in the S and mitosis phases, consistent with a role in cell division. Moreover, induced overexpression of Translin was found to accelerate cell proliferation. Confocal microscopic analysis revealed that Translin is localized at the centrosomes at prophase and the mitotic spindle at metaphase, then translocating to the spindle midbodies during cytokinesis. This novel localization is attributable to specific interactions with microtubules of the mitotic spindles, and especially gamma-tubulin. The results suggest that Translin participates in processes ensuring the segregation of chromosomes and cytokinesis.

Animals↗

PubMed2002

Enhanced secretion of tissue plasminogen activator by simultaneous use of retinoic acid and ascorbic acid from tissue cultured gastroepiploic artery.

Tissue-type plasminogen activator (tPA) is a key enzyme in the fibrinolysis system and the regulation of its expression has been extensively studied in cultured vascular endothelial cells. Many kinds of supplements including growth factors are needed, however, to keep endothelial cells viable, which leads the culture condition far from the physiological milieu. Using a new device of amorphous calcium phosphate coated culture plate, we succeeded in culturing ring-cut gastroepiploic artery in a basic medium of RPMI 1640 containing 10% fetal calf serum. The overall normal vessel architecture and the antigenicity of von Willebrand factor, tPA and plasminogen activator inhibitor type 1 (PAI-1) were retained for at least 9 days. tPA was constantly secreted into the conditioned medium at least up to day 12. Employing this organ culture technique, we analyzed the effects of two well-known profibrinolytic vitamins of retinoic acid (Vit. A) and ascorbic acid (Vit. C) on the release of tPA and PAI-1. The cultured artery responded well and the tPA secretion was enhanced by factors of 1.5 fold by Vit. A, 1.7 fold by Vit C and 3.2 fold by their combination, whereas none of these stimuli increased PAI-1 secretion. These results suggested that the cultured ring-cut artery retained functional endothelial cells for at least 9 days and was suitable in analyzing the regulatory mechanism of protein synthesis and secretion from the vascular wall. Using this method, vitamins A and C were shown to lead the intravascular condition to a profibrinolytic state.

Ascorbic Acid↗

PubMed2002

Extramedullary plasmacytoma arising from an adrenal gland.

Extramedullary plasmacytoma is a rare malignant neoplasm typically arising outside the bone marrow of patients who show no clinical evidence of multiple myeloma. We report a rare case of extramedullary plasmacytoma that was primarily found in a right adrenal lesion. Surgical excision and radiotherapy were performed for treatment of the primary lesion. Although laboratory examinations demonstrated the presence of M-protein and elevation of monoclonal IgG-lambda, a surgically excised mass revealed monoclonality of IgG-kappa. We therefore diagnosed extramedullary plasmacytoma independent of simultaneous benign M proteinemia, because the types of M-protein were quite different. One year after radiotherapy, no local recurrence was observed.

Adrenal Gland Neoplasms↗

PubMed2002

Cardiopulmonary arrest induced by anaphylactoid reaction with contrast media.

Anaphylactoid reactions to iodinated contrast media can cause life-threatening events and even death. A 44-year-old woman presented with cardiopulmonary arrest (CPA) immediately following the administration of nonionic iodinated contrast media for an intravenous pyelography. Her cardiac rhythm during CPA was asystole. She was successfully resuscitated by the radiologists supported by paged emergency physicians using the prompt intravenous administration of 1 mg of epinephrine. Neither laryngeal edema nor bronchial spasm was observed during the course of treatment, and she was discharged on the 4th day without any complications. The patient did not have a history of allergy, but had experienced a myocardial infarction and aortitis. She had undergone 11 angiographies and had been taking a beta-adrenergic receptor antagonist. Planned emergency medical backup is advisable to ensure resuscitation in the event of an anaphylactoid reaction to the use of contrast media in-hospital settings.

Adrenergic Agonists↗

PubMed2002

Correlation between QT dispersion and burn severity.

QT dispersion, defined as the maximal-minus-minimal QT interval on a 12-lead electrocardiogram, has emerged as a non-invasive measurement for quantifying the spatial inhomogeneity of ventricular repolarization under various conditions, including acute stress. Because burn injuries elicit acute stress reactions, it was hypothesized that QT dispersion increases with the severity of the burn injury. To test the hypothesis, 13 burned patients (age range of 22-76 years, nine males, ranging from 4.0 to 75.0% of total body surface area burned) in whom a measurable 12-lead electrocardiogram had been obtained within 4h after arrival at the emergency department were identified retrospectively, and their QTc intervals, i.e. QT intervals corrected for heart rate by the standard Bazett formula, were measured. QTc dispersion (QTcd) was then calculated, and correlations were assessed with burn severity (burn index, BI; prognostic burn index, PBI). Of the 13 patients, nine patients had a prolonged QTcd (>40 ms), and linear correlation analyses showed significant positive correlations between QTcd and both BI and PBI (r=0.61 and 0.62, respectively). In conclusion, QT dispersion was greater in the burned patients, and although the pathophysiology was unclear from the present study, the findings suggested that acute stress contributed to the spatial inhomogeneity of ventricular repolarization.

Adult↗

PubMed2002

Characteristics of elderly patients presenting to the emergency department with injury.

BACKGROUND: In Japan, emergency departments (ED) receive a large proportion of elderly patients each year. As such, injuries in the elderly are a common reason for presentation to the ED. Knowledge about the characteristics of injuries presenting to the ED would be invaluable in devising strategies to prevent injury in the elderly. OBJECTIVE: To analyze the characteristics of injuries in the elderly presenting to the ED and compare them with those of the younger population. SETTING: The ED at Keio University Hospital, a large inner city teaching hospital located in Tokyo. METHOD: A retrospective analysis of data extracted from the ED database of the Keio University Hospital. Information regarding patients aged 65 years or above presenting with injury was analyzed and compared with those aged less than 65 years. Prehospital triage by emergency personnel was adopted as the severity of patients, namely "life-threatening" or "non life-threatening". RESULTS: 20% of all ED presentations of elderly patients were injury related compared to 39% of non-elderly. Compared to the non-elderly, elderly patients presenting to the ED with injury were more likely to be female, sustained injury from trauma unrelated to motor vehicle accidents (MVA) and requiring hospital admission as a result of "non life-threatening" injuries. They were less likely to have injuries from MVA or burns. The number of "life-threatening" injury cases and mortality in both groups were similar. There was evidence that the number of ED presentations relating to injury is increasing in the elderly population. CONCLUSION: Elderly injury patients are a distinct group with distinctive demographics, mechanism of injury and outcomes. This information would be useful in the planning of injury prevention programs, with particular emphasis on elderly females and MVA-unrelated trauma.

Adult↗