Biomedical subjects

Y Okamoto

Publications and source records attributed to Y Okamoto.

At least 163 records · Page 9Linked to original sources

PubMed1999

Perioperative blood transfusion as a prognostic indicator in patients with hepatocellular carcinoma.

We studied the relation of perioperative blood transfusion and the outcomes in 175 patients with hepatocellular carcinoma (HCC) who underwent hepatic resection from 1986 to 1994 in our hospital. Hepatectomy was performed in 23 (13.1%) patients with and 152 (86. 9%) without blood transfusions. The cumulative cancer-free survival rates for patients who had received blood transfusion was significantly lower than that for patients who had not received blood transfusions (p = 0.003). Further examinations revealed a significant difference in cancer-free survival rates for stage I-II patients (n = 75) of HCC (p = 0.02) but not for stage III-IV patients (n = 56) (p = 0.06). Cox regression analysis for recurrence revealed that blood transfusion was the most significant prognostic indicator (p = 0.001) for recurrence in stage I-II patients but not in stage III-IV patients (p = 0.99). These results suggest that a perioperative blood transfusion may be a significant prognostic indicator for patients with HCC who had underwent hepatectomy, especially in stage I-II patients of HCC.

Adult↗

PubMed1999

Pharmacological characterization of receptor-mediated Ca2+ entry in endothelin-1-induced catecholamine release from cultured bovine adrenal chromaffin cells.

To clarify the mechanism for the endothelin-1 (ET-1)-induced release of catecholamines from the adrenal gland, we examined the effects of removal of extracellular Ca2+, blockers of L-, N-, P- and Q-types of voltage-operated Ca2+ channels (VOCC) such as nifedipine (L-type), omega-conotoxin GVIA (N-type), omega-agatoxin IVA (P-type) and omega-conotoxin MVIIC (Q-type) and blockers of voltage-independent Ca2+ entry channel such as SK&F 96365 and LOE 908 on release of catecholamines, the cytosolic free Ca2+ concentration ([Ca2+]i), and 45Ca2+ uptake in cultured bovine adrenal chromaffin cells. ET-1 but not ET-3 induced increases in release of catecholamines, [Ca2+]i, and 45Ca2+ uptake. The responses to ET-1 were abolished by the antagonist for ET(A) receptors, BQ-123, but not by the antagonist for ET(B) receptors, BQ-788, and they were abolished by removal of extracellular Ca2+. The increases were only partially inhibited (to about 65% of control) by nifedipine but unaffected by any of the omega-toxins. The nifedipine-resistant increase was inhibited by SK&F 96365 (to about 40%) and abolished by LOE 908 alone. These results indicate that ET-1 augments the release of catecholamines from adrenal chromaffin cells through ET(A) receptors, by activating two types of Ca2+ entry channels in addition to L-type VOCC: one (nonselective cation channel-1; NSCC-1) is sensitive to LOE 908 but resistant to SK&F 96365, whereas the other (NSCC-2) is sensitive to both LOE 908 and SK&F 96365.

Acetamides↗

PubMed1999

The relationship of the platelet 5-HT-induced calcium response to clinical symptoms in eating disorders.

Clinical observations indicate that persons with eating disorders exhibit many psychopathologic symptoms such as difficulty with impulse control and depressed mood associated with impaired regulation of serotonin (5-HT) synaptic function in the central nervous system. In this study, we focused on the relationship between the 5-HT-induced calcium response in platelets and the clinical symptoms. While age, body weight, and severity of depressive symptoms were not correlated with 5-HT-induced response, there was an enhanced response in patients with bulimic symptoms or other impulsive behaviors. Moreover, patients with multi-impulsive behaviors had a significantly higher maximal increase than patients with uni-impulsive behavior, i.e., those who had only bulimic symptoms, as well as non-impulsive patients, and controls. Considering these results, the 5-HT-induced response may be related to difficulty with impulse control in general rather than bulimic eating attitudes specifically.

Adult↗

PubMed1999

Determination of age-related changes in human soluble interleukin 2 receptor in body fluids of normal subjects as a control value against disease states.

A highly sensitive enzyme-linked immunosorbent assay (ELISA) system was developed for human soluble interleukin-2 receptor (sIL-2R) with an ELISA-amplification system (ELAST((R))). The sensitivity of the new method was 20-fold higher than that without the amplification. Thus very low concentrations of sIL-2R in urine can be detected. With this method, serum and urine concentrations of sIL-2R were analyzed for healthy Japanese subjects with age 1-67 years. Mean sIL-2R concentrations in both serum and urine of children were significantly higher than those of adults. However, the concentrations of children showed a progressive decline to those of adults by the age of 15 years. There was no difference in the values between males and females. The results provide a control value of sIL-2R against those in disease states such as nephrotic syndrome. Since the trends in serum and urine were found to be similar, urinary sIL-2R measurement may provide sufficient information, without measuring the blood concentration.

Adolescent↗

PubMed1999

Correlation between tumor angiogenesis and expression of thymidine phosphorylase, and patient outcome in uterine cervical carcinoma.

The relationship between tumor angiogenesis and the expression of thymidine phosphorylase (dThdPase) in uterine cervical carcinoma tissues, as well as patient outcome, were investigated. Primary tumor specimens surgically obtained from 54 patients (stages Ib to IIIb) receiving neither chemotherapy nor radiation therapy before surgery were examined. Intratumoral microvessel density (IMVD) and dThdPase expression were evaluated immunohistochemically using anti-CD34 and anti-dThdPase antibodies and were correlated with clinicopathologic parameters and prognosis. IMVD for the 54 tumors ranged from 24.8 to 118.6, with a median value of 57.7 (number/0.7386 mm2/field). For immunoreactivity of dThdPase, 16 tumors were graded as -, 20 as 1+, and 18 as 2+. IMVD was significantly associated with the expression of dThdPase (P<.01). Both IMVD and dThdPase expression were well correlated with depth of myometrial invasion, endometrial invasion, and pelvic lymphnode metastasis (P<.05). Overall survival rates for 18 patients with strong dThdPase-staining tumors, assessed as 2+, were lower than those for 36 with weak dThdPase staining tumors (P = .0108). However, there was no statistical correlation between IMVD and patient outcome. The expression of dThdPase plays a role in the promotion of angiogenesis and affects the patient's survival in uterine cervical carcinomas.

Antigens, CD34↗

PubMed1999

New Monte Carlo algorithms for protein folding.

Over the past three decades, a number of powerful simulation algorithms have been introduced to the protein folding problem. For many years, the emphasis has been placed on how to both overcome the multiple minima problem and find the conformation with the global minimum potential energy. Since the new view of the protein folding mechanism (based on the free energy landscape of the protein system) arose in the past few years, however, it is now of interest to obtain a global knowledge of the phase space, including the intermediate and denatured states of proteins. Monte Carlo methods have proved especially valuable for these purposes. As well as new, powerful optimization techniques, novel algorithms that can sample much a wider phase space than conventional methods have been established.

Algorithms↗

PubMed1999

Immunohistochemical study of fibroblast growth factor-2 (FGF-2) and fibroblast growth factor receptor (FGF-R) in experimental squamous cell carcinoma of rat submandibular gland.

Fibroblast growth factor-2 (FGF-2) is a member of the heparin-binding growth factor family and has mitogenic activity. Immunohistochemical expression of FGF-2 and its receptor (FGFR) was evaluated in experimentally induced squamous cell carcinoma as well as transforming cells of rat submandibular gland (SMG) induced by 9,10-dimethyl-1,2-benzanthracene (DMBA)/sponge implantation. Proliferating cells detected by proliferating cell nuclear antigen (PCNA) staining during carcinogenesis were also compared with FGF-2 and FGFR stainings. In the normal SMG, FGF-2 and FGFR were present in the excretory, striated and intercalated duct cells. Pillar and transition cells of granular convoluted tubule (GCT) showed FGF-2 staining, PCNA-labeled cells in normal SMG were rarely observed. In 2-3 weeks after carcinogen implantation, the reactions of FGF-2 and FGFR were expressed in epithelial islands, duct-like structures and affected ductal segments. PCNA-positive cells were developed in these epithelial structures. In 4-8 weeks after carcinogen implantation squamous epithelium appeared surrounding DMBA/sponge and gradually transforming with high PCNA labeling in the based cells and strong staining of FGF-2 and FGFR. Squamous cell carcinoma arose within about 12 weeks of the experiment. In squamous cell carcinoma, there was an intense immunohistochemical expression of FGF-2 and FGFR. Basal and parabasal layers of the squamous cell carcinoma showed high PCNA labeling. FGF-2-positive cells were found in the connective tissue stroma and in inflammatory cells around the proliferating duct-like structure. Coexpression of FGF-2 and FGFR was indicated in transforming cells during carcinogenic processes and in experimental squamous cell carcinoma of rat SMG. These findings suggested that FGF may play an important role for squamous metaplasia and carcinogenesis in rat SMG as an autocrine factor and FGF-positive stromal cells may also act to stimulate epithelial proliferation.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1999

Super catalytic antibody [I]: decomposition of targeted protein by its antibody light chain.

Obtaining an antibody capable of destroying a targeted protein is the eventual goal in developing superior catalytic antibody. We established a monoclonal antibody recognizing a highly conserved sequence, RGPDRPEGIEEEGGERDRD, of gp41 of the HIV-1 envelope. The obtained antibody reacted with gp41 and gp160 of HIV-1. The isolated and purified light chain not only decomposed the above antigenic peptide but also destroyed the gp41 molecule, indicating a novel ability. The decomposition of the antigen is presumably started by scission of the peptide bond between Arg-Gly in the above sequence. The light chain did not decompose BSA and HSA at all, showing the high specificity to antigens. The antibody light chain is referred to as a super catalytic antibody.

Journal Article↗

PubMed1999

Electrostatic effects on the alpha-helix and beta-strand formation of BPTI(16-36) studied by Monte Carlo simulated annealing.

The electrostatic effects on the secondary structure forming tendencies of a peptide fragment with residues 16-36 of bovine pancreatic trypsin inhibitor, BPTI(16-36), are studied using Monte Carlo simulated annealing simulations. We consider three dielectric functions epsilon(r) of distance r: constant dielectric function (epsilon = 2; strong electrostatic interactions) and sigmoidal functions varying from epsilon(0) = 2 to epsilon(infinity) = 47 (intermediate) and to epsilon(infinity) = 78 (weak). Simulations with epsilon = 2 suggest that this peptide exhibits a significant propensity for beta-strand formations in accordance with a beta-sheet structure of the relevant segment in native BPTI. The tendency for alpha-helix formations becomes almost comparable with that of beta-strands in the simulation with epsilon(infinity) = 47, and there appears no appreciable conformational propensity for this case. Finally, the results with epsilon(infinity) = 78 generate low-energy conformations with conspicuous alpha-helices. These findings suggest the possibility that the change in electrostatic interactions can be the key factor for the conformational transitions of peptides between alpha-helix and beta-sheet that have recently been observed in experiments. These changes in electrostatic interactions can arise from those in various environmental factors such as conformations of the rest of the protein molecule and solvent conditions.

Algorithms↗

PubMed1999

Activation of three types of voltage-independent Ca2+ channel in A7r5 cells by endothelin-1 as revealed by a novel Ca2+ channel blocker LOE 908.

1. We have shown that in addition to voltage-operated Ca2+ channel (VOC), endothelin-1 (ET-1) activates two types of Ca2+-permeable nonselective cation channel (NSCC) in A7r5 cells: its lower concentrations (< or = 1 nM; lower [ET-1]) activate only an SK&F 96365-resistant channel (NSCC-1), whereas its higher concentrations (> or = 10 nM; higher [ET-1]) activate an SK&F 96365-sensitive channel (NSCC-2) as well. 2. We now characterized the effects of a blocker of Ca2+ entry channel LOE 908 on NSCCs and store-operated Ca2+ channel (SOCC) in A7r5 cells, and using two drugs, clarified the involvement of these channels in the ET-1-induced increase in the intracellular free Ca2+ concentrations ([Ca2+]i). Whole-cell recordings and [Ca2+]i monitoring with fluo-3 were used. 3. LOE 908 up to 10 microM had no effect on increases in [Ca2+]i induced by thapsigargin or ionomycin, but SK&F 96365 abolished them. 4. In the cells clamped at -60 mV, both lower and higher [ET-1] induced inward currents with linear iv relationships and the reversal potentials of -15.0 mV. Thapsigargin induced no currents. 5. In the presence of nifedipine, lower [ET-1] induced a sustained increase in [Ca2+]i, whereas higher [ET-1] induced a transient peak and a sustained increase. The sustained increases by lower and higher [ET-1] were abolished by removal of extracellular Ca2+, and they were suppressed by LOE 908 to 0 and 35%, respectively, with the LOE 908-resistant part being abolished by SK&F 96365. 6. These results show that LOE 908 is a blocker of NSCCs without effect on SOCC, and that the increase in [Ca2+]i at lower [ET-1] results from Ca2+ entry through NSCC-1 in addition to VOC, whereas the increase at higher [ET-1] involves NSCC-1, NSCC-2 and SOCC in addition to VOC.

Acetamides↗

PubMed1999

Pharmacological characterization of Ca2+ entry channels in endothelin-1-induced contraction of rat aorta using LOE 908 and SK&F 96365.

We have recently shown that endothelin-1 (ET-1) activates two types of Ca2+-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and store-operated Ca2+ channel (SOCC). These channels can be pharmacologically discriminated using Ca2+ channel blockers such as SK&F 96365 and LOE 908. Here we characterized Ca2+ entry channels involved in ET-1-induced contractions of rat thoracic aortic rings and increases in the intracellular free Ca2+ concentration ([Ca2+]i) of single smooth muscle cells using these blockers. LOE 908 or a blocker of voltage-operated Ca2+ channel nifedipine had no effect on the contractions and increases in [Ca2+]i induced by thapsigargin or ionomycin, whereas SK&F 96365 abolished them. The contractions and increases in [Ca2+]i induced by ET-1 depended on extracellular Ca2+ but were resistant to nifedipine. The responses to lower concentrations (< or =0.1 nM) of ET-1 were abolished by either SK&F 96365 or LOE 908. The responses to higher concentrations (> or = 1 nM) were abolished by SK&F 96365, but were partially resistant to LOE 908. SK&F 96365 inhibited the LOE 908-resistant contractions induced by higher concentrations of ET-1 with IC50 values similar to those for contractions induced by thapsigargin or ionomycin. These results show that the contractions and increases in [Ca2+]i of rat aortic smooth muscles at lower concentrations of ET-1 involve only one Ca2+ entry channel which is sensitive to SK&F 96365 and LOE 908 (NSCC-2), whereas those at higher concentrations of ET-1 involve another Ca2+ entry channel which is sensitive to SK&F 96365 but resistant to LOE 908 (SOCC) in addition to the former channel.

Acetamides↗

PubMed1999

Molecular structure of canine LINE-1 elements in canine transmissible venereal tumor.

We determined the 4251-bp sequence of open reading frame 2 (ORF2) of canine LINE-1 retroposon that encodes 1275 amino acids. The truncated LINE-1 inserts associated with transmissible venereal tumor (TVT) of dogs contained the 1378-bp LINE-1 insert (TVT-LINE) flanked by 10-bp direct repeats upstream to c-myc gene. The TVT-LINE elements were composed of 416 bp inverse sequences homologous to the complementary strand of the LINE-1, a 5-bp deletion and 962-bp sequences homologous to the 3' region of the LINE-1.

Animals↗

PubMed1999

Cervical lymph nodes play the role of regional lymph nodes in brain tumour immunity in rats.

Recent physiological and anatomical studies have demonstrated that a major fraction of brain interstitial and cerebrospinal fluid drains into cervical lymph nodes (CLN) in a number of experimental animals. To investigate the role of CLN in brain tumour immunity, temporal profiles of MHC class II molecule expression and T lymphocyte subsets in brain tumours, CLN and other lymphoid tissues were analysed by immunocytochemistry. A total of 64 Wistar rats weighing 250 g were used. Two weeks after the transplantation of C6 glioma cells (10(6) cells/1 microl) into a rat brain, expression of MHC class II molecules was induced in the brain and all systemic lymphoid tissues examined. However, the subsequent appearance of CD4 or CD8 positive cells was strictly confined to CLN, and coincided with the infiltration of such cells into the brain tumour 2 weeks after transplantation. In the group of animals in which cervical lymphadenectomy was followed by intracerebral transplantation of C6 glioma cells, infiltration of CD4 or CD8 positive cells into the brain tumour was delayed until 3 weeks after the transplantation, and the production of such cells was by the spleen. These results suggest that CLN act as regional lymph nodes in brain tumour immunity.

Animals↗

PubMed1999

Intraoperative radiotherapy for the abdominal lymphatic system in patients with esophageal carcinoma.

We applied intraoperative radiotherapy (IORT) to the esophageal carcinoma in an attempt to prevent abdominal lymph node recurrence, and retrospectively studied patterns of failure and controllability of abdominal lymph nodes in patients treated with or without IORT. Between July 1986 and October 1997, 81 patients with radically resected esophageal carcinoma, aged 42-76 years (mean 61), were divided into two groups, the IORT group (39 patients) and the non-IORT group (42 patients). All patients except two, who received transhiatal esophagectomy for superficial carcinoma, underwent subtotal esophagectomy with thoracic and abdominal with/without cervical lymphadenectomy. Fourteen patients underwent only surgical resection, and the remaining 67 patients received radiotherapy to the mediastinum post-operatively (40-50 Gy/20-25 Fr/4-5 W) in 37 and preoperatively (44 Gy/40 Fr/4 W) in 30 patients. Preoperative irradiation was performed as a neoadjuvant chemoradiotherapy consisting of two courses of cisplatin (each patient received 80-100 mg, mean 60 mg m(-2), day 1, bolus injection) and 5-fluorouracil (each patient received 500-1000 mg day(-1), mean 400 mg m(-2), days 1-4, continuous infusion). The target volume of IORT encompassed the upper abdominal lymph node area including lymph node groups of right/left cardia, left gastric artery, celiac artery and abdominal para-aorta. A single dose of high-energy electrons (9-12 MeV) of 20-23 Gy, prescribed to the 90% isodose curve, was delivered. Treatment for the abdominal lymphatic system was classified into four categories: surgery alone in 30 patients, surgery with chemotherapy in 12, surgery with IORT in 15, surgery with chemotherapy and IORT in 24. There were no complications related to IORT. Forty patients (49%) had recurring carcinoma: in the lymph nodes (36%), in distant organs (27%) and locally (6%). The incidence of lymph node metastasis was 29% in the neck, 32% in the mediastinum, and 27% in the abdomen. Abdominal lymph node recurrence in the IORT group was less frequent than in the non-IORT group (p=0.048). In particular, 24 patients treated with a combination of surgery, chemotherapy and IORT had no recurrence in the abdominal lymphatic system. The overall median survival was 46 months, the survival at 1, 3, and 5 years being 85%, 52%, and 44% respectively. However, there was no difference in survival between the IORT group and the non-IORT group. The IORT for the abdominal lymphatic system was feasible for reduction of the rate of abdominal lymphatic recurrence without survival benefit in this study. This retrospective finding should be confirmed by a prospective randomized study.

Adult↗

PubMed1999

Microsomal carbonyl reductase responsible for reduction of 4-phenyl-3-buten-2-one in rats.

trans-4-Phenyl-3-buten-2-one (PBO), a flavoring additive, was transformed to the carbonyl-reduced product, trans-4-phenyl-3-buten-2-ol (PBOL) by rat liver microsomes, but not by liver cytosol, in the presence of NADH or NADPH. PBOL formed was identified by comparison with an authentic sample. The reductase activity was not inhibited by quercitrin, an inhibitor of cytosolic carbonyl reductase. The carbonyl reduction product of PBO by liver microsomes was identified as the R-enantiomer of PBOL by HPLC analysis. Rat blood also exhibited the carbonyl reductase activity in the presence of NADH or NADPH, but to a lesser extent.

Alcohol Oxidoreductases↗

PubMed1999

Serum granulocyte colony-stimulating factor kinetics in children receiving intense chemotherapy with or without stem cell support.

In a previous study, we speculated that the early phase of hematopoietic recovery after PBSC transplantation (PBSCT) is rapid because of the increased production of endogenous cytokines by co-transfused monocytes and lymphocytes (Kawano Y, et al. Blood 81:856, 1993). To clarify this point, the serum level of G-CSF was measured using an ELISA, and various other cytokines, including GM-CSF, macrophage-CSF (M-CSF), SCF, IL-6, IFN-gamma, and soluble IL-2 receptor (IL-2R), were tested for comparison in children receiving conventional or high-dose chemotherapy and autologous transplantation with unmanipulated or purified PBSC. Serum G-CSF levels in patients receiving conventional chemotherapy (n = 21) or PBSCT without exogenous G-CSF treatment (n = 19) increased to 1245 +/- 2337 pg/ml and 2741 +/- 2331 pg/ml, respectively. Likewise, the peak level of G-CSF in patients who did not receive G-CSF was statistically equivalent to the trough level in those who did. There was no significant difference in the speed of hematopoietic recovery with or without G-CSF treatment in both the conventional chemotherapy and PBSCT cohorts. In addition, no meaningful change was observed in the kinetics of other tested factors in either conventional therapy or PBSCT settings, regardless of whether the patient did or did not receive G-CSF. Endogenously produced serum peak G-CSF levels after PBSCT with purified CD34+ cells were identical to those after the same procedure with unmanipulated cells. These results confirm that children receiving intense chemotherapy followed by autologous PBSCT produce a high level of G-CSF during the cytopenic period that is not due to the infusion of a large amount of facilitating cells capable of producing G-CSF.

Adolescent↗

PubMed1999

Comparative evaluation of procedures with a Baxter CS-3000 cell separator for collecting peripheral blood cells from children.

The safety and efficacy of apheresis using a newly developed procedure with a small volume separation container holder (SVSCH, Baxter) for the collection of PBSC from children with cancer were retrospectively compared with our historical experience with other procedures using different equipment and the CS-3000 plus cell separator. The procedures tested included the application of (a) specialized collection protocol 4 using the combination of an SVSCH and a small volume collection chamber (SVCC) (group A: 6 collections in 4 patients), (b) standard lymphocyte collection protocol 3 with GRANULO separation (G) and A-35 collection chambers (group B: 9 collections in 5 patients), and (c) modified collection procedure 1-120 with G and SVCC (group C: 7 collections in 3 patients). Although the retrospective nature of this study and the differences in the cohorts tested prevent a reliable analysis, the percent decrease in the peripheral platelet count after collection tended to be minimum in group A (11% +/- 5% versus 23% +/- 4% [B] or 17% +/- 4% [C]). Moreover, the largest number of CD34+ cells was collected in group A (8.7 +/- 9.4 x 10(5)/100 ml processed blood) compared with groups B (5.5 +/- 7.5 x 10(5)/100 ml processed blood) and C (4.0 +/- 2.8 x 10(5)/100 ml processed blood). These data suggest that a procedure incorporating SVSCH can be safely and effectively applied to small children and enables the selective collection of PBSC with less contamination by platelets, which is useful for subsequent cell processing.

Adolescent↗

PubMed1999

Conversion of brain-specific complex type sugar chains by N-acetyl-beta-D-hexosaminidase B.

The N-linked sugar chains, GlcNAcbeta1-2Manalpha1-6(GlcNAcbeta1-4)(Manalpha1++ +-3)Manbeta1-4GlcNAcb eta1-4(Fucalpha1-6)GlcNAc (BA-1) and GlcNAcbeta1-2Manalpha1-6(GlcNAcbeta1-4)(GlcNAcbeta1 -2Manalpha1-3)Manb eta1-4GlcNAcbeta1-4(Fucalpha1-6)GlcNAc (BA-2), were recently found to be linked to membrane proteins of mouse brain in a development-dependent manner [S. Nakakita, S. Natsuka, K. Ikenaka, and S. Hase, J. Biochem. 123, 1164-1168 (1998)]. The GlcNAc residue linked to the Manalpha1-3 branch of BA-2 is lacking in BA-1 and the removal of this GlcNAc residue is not part of the usual biosynthetic pathway for N-linked sugar chains, suggesting the existence of an N-acetyl-beta-D-hexosaminidase. Using pyridylaminated BA-2 (BA-2-PA) as a substrate the activity of this enzyme was found in all four subcellular fractions obtained. The activity was much greater in the cerebrum than in the cerebellum. To further identify the N-acetyl-beta-D-hexosaminidase, BA-1 and BA-2 in brain tissues of Hex gene-disrupted mutant mice were detected and quantified. PA-sugar chains were liberated from the cerebrum and cerebellum of the mutant mice by hydrazinolysis-N-acetylation followed by pyridylamination. PA-sugar chains were separated by anion-exchange HPLC, size-fractionation, and reversed-phase HPLC. Each peak was quantified by measuring the peaks at the elution positions of authentic BA-1-PA and BA-2-PA. BA-2-PA was detected in all the PA-sugar chain fractions prepared from Hexa, Hexb, and both Hexa and Hexb (double knockout) gene-disrupted mice, but BA-1 was not found in the fractions from Hexb gene-disrupted and double knockout mice. These results indicate that N-acetyl-beta-D-hexosaminidase B encoded by the Hexb gene hydrolyzed BA-2 to BA-1.

Animals↗