Bone mineral density assessment for research purpose using dual energy X-ray absorptiometry

Dual energy X-ray absorptiometry (DXA) has become the most common method for measuring bone mineral density (BMD) of small animals in metabolic bone disease research, and errors should be minimized in all procedures involved in research studies in order to increase the accuracy of the study results. DXA is simpler and rapid compared to Micro-computed tomography for quantitative analysis of change in trabecular bone of test subject. In human research, measuring BMD is widely used; post-operative evaluation on orthopedic surgery, evaluation of osteoporosis medication in menopause and many other areas of study. For the study, the inspector should be trained by the equipment manufacturer regarding the utilization and analysis of the equipment and regular phantom testing should be conducted to ensure the stability of the equipment, and precision tests should be conducted to analyze the positioning and data analysis. They should also be familiar with the clinical trials and conduct studies based on the approval of the Institutional Review Board. In the absolute BMD measurement of the human body, it is necessary to apply and compare the position and condition, rotation degree, region of interest, and area of the scan in the follow-up test. In the case of small animals, animal selection, measurement and equipment should be modeled to match the research. Therefore, we would like to provide information for researchers to minimize the errors, effective data management and accurate data presentation. This article reviews the process of DXA measurement for research purpose including plan for DXA examination, BMD measurement in a human body study and small animal studies.

Auto-antibody Showing Anti-Fy(b) Specificity as Proven by the Dilution Method in the Presence of Warm Autoantibodies: A Case Report / 대한수혈학회지

Several approaches have been introduced to detect allo-antibodies in the presence of warm auto-antibodies, and these methods include warm autoadsorption, cysteine-activated papain and dithiothreitol (ZZAP), and polyethylene glycol (PEG) and dilution of the patient's serum. Among them, the dilution technique is a simple and rapid method. During pretransfusion testing of a 33 year-old systemic lupus erythematosus (SLE) patient with warm auto-antibodies, antibody identification was done by the dilution technique with using serum diluted 1-in-8. The patient demonstrated an anti-Fy(b) pattern of reactivity in his sera. Contrary to our expectations, the phenotype of the erythrocytes was Fy(a+/b+) and the genotype, as assessed by performing PCR-restriction fragment length polymorphism (RFLP), was FY*A/FY*B. These results suggest that the antibody is an autoantibody showing anti-Fy(b) specificities. An antibody identification test using undiluted serum showed the same result when 40 days had passed. We report here on a case with auto-anti-Fy(b) proven by the dilution method in the presence of warm autoantibodies.

Fungemia due to Exophiala dermatitidis / 대한임상미생물학회지

We report a rare case of fungemia due to Exophiala (Wangiella) dermatitidis in a 4-month-old female infant who was admitted to an intensive care unit with sudden infant death syndrome (SIDS). E. dermatitidiswas repeatedly isolated from blood cultures (on the 28th and 32nd day of hospitalization) of the patient, who died on the 44th day of hospitalization. The fungus was identified by its morphological characteristics and DNA sequencing of both the D1/D2 domain and the ITS region of rDNA. To our knowledge, this is the first reported case of E. dermatitidis fungemia in Korea.

Usefulness of a Chromogenic Selective Agar for the Identification of Bacillus cereus Isolated from Blood Cultures / 대한진단검사의학회지

BACKGROUND: The incidence of Bacillus cereus bacteremia is increasing, but the identification of Bacillus species remains difficult. Brilliance Bacillus cereus agar (BBC agar; Oxoid, UK) is a new CHROMagar medium that allows selective isolation and identification of B. cereus; however, its clinical usefulness is seldom studied. We evaluated the usefulness of BBC agar to identify B. cereus isolates recovered from blood cultures. METHODS: We analyzed a total of 53 blood isolates that showed a Bacillus-like morphology on Gram staining. All isolates were identified by using both the API Coryne (bioMerieux, France) and API 50CH/B (bioMerieux) systems. They were subsequently subcultured on BBC agar, incubated for 24 hr, and then examined for characteristic blue-green colonies. The clinical characteristics of patients whose isolates were identified as B. cereus were assessed. RESULTS: Of the 53 isolates, 18 were identified as B. cereus by API 50CH/B. With the API 50CH/B system used as gold standard, the sensitivity and specificity for the identification of B. cereus were 100% (18/18) and 100% (35/35), respectively, using BBC agar, and 67% (12/18) and 100% (35/35), respectively, using the API Coryne system. Of the 18 patients with B. cereus bacteremia, 15 showed infectious signs, and 3 had more than 2 blood cultures positive for B. cereus on separate days. CONCLUSIONS: Our study shows, for the first time, that BBC agar, with its good agreement and ease of use, is a valuable alternative to the API 50CH/B system for the presumptive identification of B. cereus isolates from blood cultures.

Central Venous Catheter-Related Microbacterium Bacteremia Identified by 16S ribosomal RNA Gene Sequencing / 대한임상미생물학회지

We describe here a case of central venous catheter (CVC)-related bacteremia caused by Microbacterium species in a 14-year-old patient, who had received chemotherapy for acute lymphoblastic leukemia. All nine blood cultures obtained from admission day 2 to day 62 yielded the same yellow-pigmented coryneform rod. Both Vitek 2 (bioMerieux, USA) and MicroScan (Dade Behring, USA) identified the isolate as Micrococcus species, and the API Coryne (bioMerieux, France) identified the isolate as Rhodococcus or Brevibacterium species. However, the 16S rRNA gene sequence showed a 99% identity with Microbacterium species. The bacteremia was recurrent or persistent over 60 days despite alternate systemic antibiotic therapy, but blood culture became negative after an addition of teicoplanin lock therapy for eradicating CVC-related bacteremia. This represents the first report of CVC-related Microbacterium bacteremia cured by antibiotic lock therapy in Korea.

Chimerism Proven by Flow Cytomety in the Setting of an ABO Discrepancy: A Case Report / 대한수혈학회지

Chimerism is an important, yet uncommon cause of ABO phenotype/genotype discrepancies. The propositus was a 28 year-old pregnant women who had an ABO discrepancy, expressing an A(weak)B RBC phenotype and AB reverse type. Sequencing of ABO exons 6 and 7 revealed a B101/O01 genotype. Neither analysis of 9 short tandem repeats (STR) loci nor HLA typing on DNA extracted from white blood cells demonstrated evidence of chimerism. However, flow cytometric analysis using a PE-conjugated anti-A mouse monoclonal antibody detected a small population (3.8%) of red cells expressing normal A antigen. Based on this, we suggest that flow cytometric analysis is an effective method for the identification of small chimeric populations of RBCs in the immunohematology laboratory.

Cytologic Features of Endodermal Sinus Tumor of Ovary in the Ascitic Fluid: Report of a Cases / 대한세포병리학회지

The cytologic findings of endodermal sinus tumor of the ovary are reported. The cytologic preperations were obtained from ascitic specimens. The findings on Papanicolaou-stained smears included a clean background and poorly preserved atypical cells loosely arranged in irregular or papillary groups. At high magnification, the cells had ill-defined and microvacuolated cytoplasms, with an increased nuclear-cytoplasmic ratio and prominent nucleoli. Hyaline globules characteristic of the alpha-fetoprotein (AFP)-synthesizing cells of endodermal sinus tumor were observed within the cells with periodic-acid-Schiff (PAS) stain. The presence of PAS - positive hyaline globules can be regarded, therefore, as a diagnostic clue to endodermal sinus tumor in an appropriate clinical setting and in the presence of AFP production. The cytologic findings in a cell block is important, in addition to smears, to obtain more diagnostic clues. A preliminary cytomorphologic diagnosis of this highly malignant tumor is valuable as a guide in planning further immunocytochemical and serologic studies.