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Biomedical subjects

T Tomono

Publications and source records attributed to T Tomono.

At least 19 recordsLinked to original sources
PubMed2004

Removal of small non-enveloped viruses by nanofiltration.

BACKGROUND AND OBJECTIVES: Nanofiltration is one of the most effective virus reduction methods in the manufacturing process of plasma products. However, it is difficult to remove small viruses from high molecular weight protein preparations like immunoglobulin G or factor VIII complex by nanofiltration, because the size of the protein is similar to that of viruses. In order to separate the viruses from these proteins by nanofiltration, it is necessary to change the size of either one. In this study, we report that such non-enveloped viruses as human parvovirus B19 (B19), human encephalomyocarditis virus (EMC) or porcine parvovirus (PPV) aggregate in the presence of certain kinds of amino acids and could be easily removed by nanofiltration. MATERIALS AND METHODS: 0.3 M Glycine (or other amino acid) solution spiked with viruses was subjected to dead-end single filtration with a 35-nm pore-size filter. Virus removal by nanofiltration was either evaluated by PCR or by infectivity assay. RESULTS: B19 in a 0.3 M glycine solution was reduced to 1:10(7.5) (7.5-log) by nanofiltration with a 35-nm pore-sized filter, whereas in PBS it was not reduced. Similarly, B19 was also reduced when suspended in other amino acids solutions. This effect was also confirmed with the other small non-enveloped viruses EMC or PPV. When 5% globulin or 5% albumin was added to a 0.3 M glycine solution, the removal rate was decreased. CONCLUSIONS: These data suggest that viruses in the presence of certain kinds of amino acids could be aggregated and effectively removed by a filter that has a pore size larger than the size of the viruses.

Animals↗
PubMed2002

Status of NAT screening for HCV, HIV and HBV: experience in Japan.

The first nationwide nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) of voluntarily donated blood after serological pre-screening and before release of cellular components and plasma for fractionation was implemented by the Japanese Red Cross Blood Transfusion Services. The NAT screening assay using multiplex reagent is time-saving, cost effective, and labour-saving procedure for all blood and blood products including short-shelf life platelets. During the 50-mini-pool NAT screening of serologically negative donations (February 1, 2001-April 30, 2001), we were able to screen out 112 HBV-positive, 25 HCV-positive, and 4 HIV-1 positive units from blood and blood components.

Blood↗
PubMed2001

The first large-scale nucleic acid amplification testing (NAT) of donated blood using multiplex reagent for simultaneous detection of HBV, HCV, and HIV-1 and significance of NAT for HBV.

The first nationwide nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) of voluntarily donated blood after serological pre-screening and before release of cellular components and plasma for fractionation was implemented by the Japanese Red Cross Blood Transfusion Services. From February 1, 2000 to April 30, 2001, specimens from 6,805,010 units of serologically negative donation were screened in minipools of 50 samples within 24 hr after blood donation by NAT using multiplex HBV/HCV/HIV-1 reagent for blood transfusion including short shelf-life platelets. Among them, 112 HBV DNA-positives, 25 HCV RNA positives and 4 HIV-1 RNA positives were screened out and we could prevent transfusion of these NAT positive units. Subtypes/genotypes of HBV DNA, adr/C, adw/A, adw/B, adw/C, ayr/C and ayw/D were found and adr/C was predominant. A total of 61.6 % of them (69/112) were negative by overnight EIA. Sixth three of HBV NAT-positive samples carried virus loads less than 10(4) copies/mL and 92.1 % of them (58/63) were negative by overnight EIA. The virus growth curves of HBV in 6 cases obtained by retrospective and prospective follow-up study showed exponential straight lines in the early stage of serological window periods and the log times of HBV growth (10 fold increase) in serological window period were between 4.6 and 7.6 days. NAT screening with highly sensitive reagents in pool of specimens is useful to exclude blood units with low level of HBV and HBV mutants from blood transfusion.

Blood Donors↗
PubMed1989

Interactions of human serum albumin with a modified poly(vinyl alcohol) gel packing for high-performance liquid chromatography.

The interactions of human serum albumin (HSA) with a poly(vinyl alcohol) gel packing (Asahipak GS-520) for high-performance liquid chromatography of proteins were investigated. Under certain conditions, the elution of HSA from the GS-520 column was retarded and its chromatogram was split into two peaks, indicating weak adsorption of HSA onto the gels and also the existence of two subfractions, i.e. human mercapto-albumin (HMA) and human non-mercapto-albumin (HNA). The chromatograms were confirmed to be greatly influenced by the salt composition, the pH, and the temperature of the isocratic mobile phase. It is characteristic for the adsorption of HSA onto the gels to be suppressed at a pH near its isoelectric point. The HSA-gel interaction parameters calculated using an adsorption chromatography theory demonstrate that the adsorption of HSA is caused by enthalpy-driven interactions, which are depressed by lowering the pH, in addition to hydrophobic interactions. Under the recommended chromatographic conditions for high resolution of HMA/HNA, it was found that the HSA samples possessed some subfractions besides HMA and HNA fractions.

Chromatography, High Pressure Liquid↗
PubMed1989

Physicochemical and biological properties of poly(ethylene glycol)-coupled immunoglobulin G. Part II. Effect of molecular weight of poly(ethylene glycol).

In order to obtain a stable human immunoglobulin G (IgG) preparation for clinical use, the chemical coupling of different molecular weights of poly(ethylene glycol)s (PEGs) to IgG molecules was achieved. The abilities of PEG-coupled IgGs (PEG-IgG hybrids) to aggregate were examined when they were subjected to such physicochemical treatments as interfacial exposure, heating, lyophilization, and acid treatment. It was found that the higher the molecular weight of PEG coupled, the more stable was the PEG-IgG hybrid obtained concerning interfacial exposure and heating. The hybrid was stable against lyophilization and acid treatment and its stability was independent of the PEG molecular weight. The decrease in antigen binding ability was suppressed as much as possible by the use of a small amount of PEG of higher molecular weight. The PEG-IgG hybrids were further assessed as a stabilizer for IgG. A limited degree of PEG coupling was required for the hybrids to achieve the most efficient stabilization of IgG; the optimal PEG contents of the hybrid were greater than 20 wt% (interfacial exposure), about 5 wt% (heating), 20 wt% (lyophilization), and 10 wt% (acid treatment) for PEG 5600. It was also confirmed that the PEG-IgG hybrid was superior to PEG and human serum albumin as a stabilizer.

Antigen-Antibody Reactions↗
PubMed1989

[One-stage resected case of dumbbell type tumor of the posterior mediastinum].

We reported a dumbbell type tumor of the posterior mediastinum. The patient was an asymptomatic 40-year-old male. An abnormal shadow in the right lower lung field was pointed out in a mass survey. We recognized a dumbbell type tumor in the posterior mediastinum by chest CT and MRI. The tumor invaded the intervertebral canal through the spinal foramen. It was most clearly seen by MRI myelography. Operation was performed with the patient in a prone position and with an L-shaped skin incision of the back and 11th intracostal thoracotomy and Th11 laminectomy. The dumbbell type tumor was completely removed by this operation. The pathological diagnosis was Schwannoma. The post operative course was good. The one-stage operation is useful for dumbbell type tumors of the posterior mediastinum.

Adult↗
PubMed1988

[A cytologic diagnosis of breast secretions--application of cytology to the mass survey of breast cancer].

From January 1982 to March 1987, an exfoliative cytological examination of abnormal nipple discharge was carried out on 790 patients. Of 22 histologically confirmed mammary carcinomas, 7 cases (31.8%) were diagnosed as positive by conventional cytologic techniques. By using the concentration method, in which the nipple secretion was collected in a series of testings that lasted 3 to 5 days and stored in a glass tube containing a fixative, the diagnostic accuracy was seen to increase significantly and 9 out of 15 malignant cases (60.0%) were accurately diagnosed as having cancer. Moreover, all 5 cases without any palpable mass were found to be positive by the smears made by this procedure.

Adult↗
PubMed1986

A new intact immunoglobulin for intravenous use stabilized by chemically modified gelatin derivatives.

The stabilization of human immunoglobulin (IgG) by chemically modified gelatins (Haemaccel and Gelofusine) was investigated. The gelatins prevented IgG from aggregation induced by exposure to interfaces and lyophilization. The stabilization effects of the gelatins were significantly larger than those of amino acids or sugars. These investigations led to the large-scale production of an immunoglobulin preparation for intravenous use in the clinic. The clinical product meets the Japanese minimum requirements for immunoglobulin preparations for intravenous use, and the long-term preservation of this new freeze-dried preparation has demonstrated its stability.

Amino Acids↗
PubMed1985

Cryptotia: our classification and treatment.

Our classification of cryptotia is based on recognition that the deformity is the result of an anomaly of the intrinsic transverse and oblique auricular muscles. Our treatment, in the first instance, is a non-surgical correction. This should be started early, if possible in the first 6 months of the baby's life. Even in the case of older children, success can sometimes be achieved and a non-surgical correction should be considered first. If non-surgical management fails the deformity can be corrected surgically by dividing the muscle fibres that produce the anomaly of the external ear through a small incision. Our new surgical approach involves moving the available skin in the region of the inferior cephalo-auricular sulcus to the superior part where skin is needed by a rotation flap. This operation has several advantages.

Age Factors↗
PubMed1984

Physicochemical and biological properties of poly(ethylene glycol)-coupled immunoglobulin G.

In order to develop a new intravenous immunoglobulin G (IgG), IgG was covalently coupled to poly(ethylene glycol) previously activated by cyanuric chloride. The poly(ethylene glycol) coupled IgG obtained was studied for physicochemical and biological properties such as molecular structure, size-exclusion chromatographic behaviour, surface activity, interfacial aggregability, heat aggregability inducing nonspecific complement activation, and antigen-binding activity. The poly(ethylene glycol) coupling to IgG increased the apparent Stokes' radius and the surface activity of IgG and stabilized IgG on heating and/or on exposure to interface, while no structural denaturation of IgG was observed. The suppressed nonspecific aggregability was interpreted mainly by difficulty in association between the modified IgG molecules. These results indicated the use of the poly(ethylene glycol)-coupled IgG as an intravenous preparation and also as an additive stabilizing intact IgG for intravenous use.

Complement Activation↗
PubMed1983

High-performance ion-exchange chromatography of plasma proteins.

The use of anion-exchange high-performance liquid chromatography columns for the analysis of plasma proteins has been investigated. Mono Q and Polyanion SI were used as anion-exchangers. Several factors, including solvent composition, pH, flow-rate, sodium chloride linear concentration gradient and sample loading capacity, were examined for their effects on the resolution of protein standards and pooled human plasma (PHP). PHP was separated into ten or more protein fractions by a Mono Q column (50 X 5 mm I.D., flow-rate 2 ml/min) within 10 min. Components analysis of each fraction was performed using immunochemical methods and size-exclusion high-performance liquid chromatography. The Mono Q column was applied to the analysis of IgG myeloma and other patient plasma samples.

Blood Proteins↗