Aortic atheromatous lesions developed in APA hamsters with streptozotocin induced diabetes: a new animal model for diabetic atherosclerosis. 1. Histopathological studies

To develop an adequate animal model for atherosclerosis in large vessels of patients with diabetes, i.e. diabetic macroangiopathy, we induced diabetes in APA hamsters with a single injection of streptozotocin (SZ) and examined the aorta histopathologically and immunohistochemically. As a result, hyperglycemia and hyperlipidemia were continuously observed for 26 weeks after the SZ injection (WAI) in APA hamsters. Fatty streaks characterized by a subendothelial accumulation of many foam cells were observed, limited to the aortic arches as early as 6 WAI. In addition to larger fatty streaks developing with the duration of diabetes, fibrous plaques and plaques containing calcium deposits or cholesterol clefts developed at 26 WAI. These lesions are generally similar to the atheromatous lesions developed in humans. Moreover, depositions of apolipoprotein E and advanced glycation end-products immunohistochemically detected in the lesions were very similar to those found in humans. The diabetic APA hamster is therefore considered to be a useful model for studying the formation of atheromatous lesions in diabetic patients.

Undefined complications of parathyroid adenoma, parathyroid hyperplasia (primary hyperparathyroidism), thyroid follicular adenoma, thyroid papillary carcinoma, temporal astrocytoma, cerebellar meningioma, and hemangioma of external auditory meatus and oral papilloma

A 59-year-old woman who had parathyroid adenoma, parathyroid hyperplasia, thyroid follicular adenoma, thyroid papillary carcinoma, astrocytoma of the right temporal lobe, cerebellar meningioma, capillary hemangioma of the left external auditory meatus and papilloma of the left upper gingiva is reported. Dynamic magnetic resonance imaging, computed tomography with contrast-enhancement and gastrofiberscopy revealed no remarkable findings in the pituitary, pancreas, adrenals, stomach or duodenum. Similar lesions were not found in any family members. Defect of the causative genes of multiple endocrine neoplasia types I and IIa, MENIN and RET was not detected. Further follow-up of this patient and family members is needed.

APA hamster model for diabetic atherosclerosis. 2. Analysis of lipids and lipoproteins

Syrian hamsters of the APA strain (APA hamsters) have recently been shown to have atheromatous lesions in the aortic arches under diabetic condition induced by a single injection of streptozotocin (SZ). In that model, fatty streaks, which are the initial lesions of atherogenesis, develop by 6 weeks after the injection (WAI). In this study, we evaluated plasma lipid concentrations and lipoprotein profiles in diabetic APA hamsters at 6 WAI to reveal the early stage of atherogenesis clinicopathologically. As a result, by biochemical analysis, hyperglycemic APA hamsters showed signs of hypercholesterolemia and hypertriglyceridemia. Low-density lipoprotein (LDL) cholesterol significantly increased, but high-density lipoprotein (HDL) cholesterol significantly decreased. Agarose gel electrophoresis showed an obvious increase in the fractions of chylomicron, LDL and abnormal lipoprotein. Plasma LDL in diabetic animals was in a state more susceptible to oxidization. In addition, a significant increase in glycated LDL was also found in the diabetic animals by enzyme linked immunosorbent assay (ELISA). Moreover, lipid peroxidation product (4-hydroxynonenal (4 HNE))-adducted proteins and advanced glycation end-products (AGE) were immunohistochemically detected in the foam cells of the fatty streaks. These results revealed that diabetic APA hamsters had hyperlipidemia characterized by increases in chylomicron, LDL and abnormal lipoprotein, and suggested that oxidized LDL and/or glycated LDL might be actively uptaken by macrophages and play an important role in the initial stage of atherogenesis.

Immunohistochemical expression of Bcl-2, Bax and cytochrome c following focal cerebral ischemia and effect of hypothermia in rat

Recent studies suggest that mild hypothermia significantly alleviate damage following cerebral ischemia though the precise mechanism is poorly defined. In the present study, middle cerebral artery occlusion (MCAo) was induced in Sprague-Dawley (SD) rats for 1 h followed by varying periods of reperfusion. Cerebral infarcts identified by hematoxylin & eosin (H&E) staining revealed extensive lesion in normothermic (NT) 37 degrees C and small lesion in hypothermic (HT) 33 degrees C group of rats. Immunohistochemical analysis revealed Bcl-2 was induced in many neurons of HT group, while Bax and cytochrome c was induced in few neurons. In situ detection of DNA fragmentation using 3'-OH end labeling method (terminal dUTP nick-end labelling (TUNEL)) indicated, higher number of TUNEL-positive cells in NT group, but significantly decreased in HT group. The expression pattern revealed many neurons at the penumbra region could survive in HT group whereas, many neurons are committed to die in NT group. Our results suggest that hypothermia is selectively interfering at more than one place and providing protection.

Characterization of p26olf, a novel calcium-binding protein in the frog olfactory epithelium

We have previously shown that p26olf is a novel S100-like Ca(2+)-binding protein in the frog olfactory epithelium. In this paper, we characterized the Ca(2+) binding property of p26olf, examined the precise localization in the frog olfactory epithelium, and searched for the possible target proteins of p26olf. By flow dialysis experiments using (45)Ca, p26olf was suggested to bind approximately 4 Ca(2+). Circular dichroism measurement showed that binding of Ca(2+) to p26olf induces an increase in the apparent content of both alpha-helix and beta-sheet with an apparent K(d) value of 2.4 micrometer. Electron microscopic observation disclosed p26olf immunoreactivity in the cilia, dendritic knob, and dendrite of olfactory receptor cells. Blot overlay analysis and affinity purification of p26olf-binding proteins showed that p26olf binds to a frog beta-adrenergic receptor kinase-like protein in a Ca(2+)-dependent manner. These results suggested that p26olf has some roles in the olfactory transduction or adaptation.

Purification of bovine urinary beta2-microglobulin and its biochemical characteristics

In this study, bovine beta2-m was purified from urine by ion-exchange chromatography and gel chromatography, and the characteristics were compared with those of colostral beta2-m by the immunological reactivity, isoelectric points, peptide map, and amino acid sequence. The characteristics of purified urinary beta2-m were consistent with those of the colostral beta2-m. The urinary and colostral beta2-m possessed the same polypeptide chain consisting of 98 amino acids, and its molecular weight is 11.8 kDa. Furthermore, four isoforms of beta2-m were found. The isoelectric points were different from each other.

Synthesis and DNA-binding of acridine-netropsin hybrid molecules

We have designed and synthesized acridine-netropsin hybrid molecules. Spectroscopic (absorption, CD, flow dichroism and fluorescence) measurements reveal that hybrid molecules interact with DNA by both intercalation and minor-groove binding and shows enhanced preference for AT-rich sites.

Localization and age-related changes in cytochrome P450 expression in APA hamster livers

To establish the baseline data, age-related changes and the regional expression of the hepatic P450 isozymes in Syrian hamsters of the APA strain at 3, 6, 12, 18 months old were examined by immunological techniques. Immunohistochemical analysis of liver serial sections revealed that the midzonal and perivenous regions (zones 2 and 3, respectively) were stained with the anti-rat CYP1A1/2, 2B1/2 and 2E1 antibodies. These three antibodies most intensely stained the hepatocytes around the central vein. An anti-rat CYP3A2 staining section had a staining pattern with equally intense reactions in zones 2 and 3. On the other hand, CYP2C6, 2C11 and 4A1 were distributed diffusely throughout the hepatic acinus. There was no age-related difference in the expression pattern of any of the P450 isozymes examined. Total P450 content had a peak at 6 months of age and decreased to 60% of that level thereafter. Western-blot analysis revealed that the peak expressions of the isozymes detected with anti-rat CYP1A1/2, 2C6, 2E1 and 3A2 antibodies were observed in 6-month-old hamsters and declined in older ones. The CYP2B and 2C11 content reached the maximum at the age of 6 months and maintained almost the same level thereafter. The CYP4A level did not change from 3 to 6 months, and then declined to about 40% of the younger level at 12 and 18 months of age. These results suggest that the hepatic P450 isozymes of APA hamsters have region-specific expressions and most isozymes have their peaks of expression at 6 months of age, which differs from the patterns for rat P450.

Peripheral blood extrathymic CD4(+)CD8(+) T cells with high cytotoxic activity are from the same lineage as CD4(+)CD8(-) T cells in cynomolgus monkeys

We have previously reported that CD4/CD8 double-positive (DP) T cells with the resting memory phenotype are present in the periphery of healthy cynomolgus monkeys. In the present study, we performed functional studies on the T cells. The expression of CD4 and CD8 on DP, CD4 single-positive (SP) or CD8 SP T cells was stable in cultures with either mitogen or anti-CD3 antibody stimulation. In spite of lacking CD28 expression, DP T cells showed similar proliferative ability and apoptosis sensitivity to CD4 SP and CD8 SP T cells. DP T cells showed both helper and cytotoxic activities. Although the helper activity of DP T cells was lower than that of CD4 SP T cells, cytotoxic activity was comparable to that of CD8 SP T cells. Fresh DP T cells killed target cells mainly by the perforin-granzyme pathway. In addition, fresh DP T cells expressed a high level of mRNA for IFN-gamma and produced a high level of IFN-gamma when they were activated by anti-CD3 antibody ligation. On the other hand, several expanded DP T cell clones shared TCR V(beta) with expanded CD4 SP T cell clones, strongly suggesting that those two corresponding clones with DP and CD4 SP phenotypes might be derived from the same ancestor T cell. These results showed that the DP T cells are a novel T cell subset with functions overlapping with those of CD4 SP and CD8 SP T cells, and that they might play protective and regulatory roles in secondary immune response in cynomolgus monkeys.

The survey of sleeping time of junior high school students: a study on the sleep questionnaire

We investigated the questionnaire study on sleep of junior high school students to estimate the effect of excessive study hours on their sleep time in 1998. A total of 501 students answered the questionnaire. It was noted that most of the students sleep for 6-8 h on weekdays. The majority of the students of the junior high school felt that their sleep is insufficient on weekdays.

Echocardiographic evaluation of the ductal morphology in patients with refractoriness to lipo-prostaglandin E1 therapy

BACKGROUND

Lipo-prostaglandin (PG)E1 is effective at lower doses and has fewer side effects than PGE1-cyclodextrin (CD). Previous studies, however, have suggested that some patients show refractoriness to lipo-PGE1 in the course of treatment. The present paper examines: (i) whether such cases can be predicted by examining the ductal morphology before and 24 h after the start of lipo-PGE1 infusion; and (ii) whether PGE1-CD dilates the ductus arteriosus in patients with refractoriness to lipo-PGE1.

METHODS

The ductal morphology was evaluated with two echo indices, such as minimal and minimal plus maximal intraluminal diameters of the ductus. Two-dimensional echocardiography was performed in 24 patients with ductus-dependent congenital heart disease. The two echo indices were measured before and 24 h after lipo-PGE1 infusion and also at least twice per week until surgery.

RESULTS

In 19 of 24 patients, ductal patency was maintained until surgical treatment (group A). The remaining five patients (21%) showed ductal closure during the course of the lipo-PGE1 therapy (group B). There were no significant differences between the two groups, in either the maximal or minimal diameters, which were examined before and 24 h after treatment. In the five patients of group B, lipo-PGE1 was replaced with a relatively high dosage of PGE1-CD (50-100 ng/kg per min), resulting in good ductal patency until surgery.

CONCLUSIONS

Patients with refractoriness to lipo-PGE1 therapy could not be predicted from initial intraluminal diameters of the ductus using echocardiography. Therefore, serial echocardiographic examinations are important to detect early findings of ductal closure. In addition, PGE1-CD is still useful as back-up therapy in such patients.

[Factors in continuation of home health care for patients with intractable neurological diseases]

OBJECTIVE

This study was carried out to elucidate factors related to difficulty in continuing home health care and to investigate problems of the corresponding support system for patients with intractable neurological diseases.

SUBJECTS AND METHODS

Subjects were 139 cases of amyotrophic lateral sclerosis (ALS), 376 cases of spino-cerebellar degeneration (SCD) and 1,048 cases of Parkinson's disease (PD) who were collected from the nationwide survey of health and social service needs of the patients with intractable diseases in 1995. Factors and problems related to limited activity due to diseases and necessity for medical care were analysed. The need for facilities of long-term care was also studied.

RESULTS

The characteristic conditions of patients with ALS were shorter duration of the illness, higher percentage of conditions requiring medical care and disorders of swallowing or respiration and full nursing care in daily life compared with the other two diseases. The characteristics of PD were higher percentage of female and older age in both patients and their family caregivers. The proportion of cases for whom health care was judged to be prone to difficulty was 23.0% in ALS, 10.9% in PD and 7.2% in SCD, respectively. Regarding the factors related to difficulty in continuing home health care, conditions requiring medical care, the need for full nursing care in daily life, and the duration of the illness were recognized in ALS. In SCD, 5 factors, including conditions requiring medical care, the need for full nursing care in daily life, patients age greater than 65 years, the duration of the illness, and patients being nursed by their sons or daughters were detected. In PD, 4 factors, such as conditions requiring medical care, the need for full nursing care in daily life, the patients being nursed by persons other than the spouse, and the need of nursing care were found.

CONCLUSION

These results suggest the necessity of social functions of medical care, nursing and family support that can be supplied at home effectively according to symptoms in progress, and the need for facilities of long-term care of patients for whom continuation of home health care may become difficult, which will work as a support system for long-term care of patients with intractable neurological diseases.

Clinical evaluation of 61 patients with pulmonary aspergilloma

OBJECTIVE AND METHODS

We retrospectively evaluated 61 cases with pulmonary aspergilloma representing patients admitted to Nagasaki University Hospital between January 1991 to June 1998.

RESULTS

Fifty-two (85%) were males and 9 (15%) were females, aged between 14 to 80 years (average, 65 years). Forty-four (72%) patients had history of old pulmonary tuberculosis. Chest radiographs showed "fungus ball" in the cavities in 42 (67%) cases while 16 (26%) cases showed thickening of the cavity wall. Aspergillus fumigatus was isolated in 24 (39%) patients. Aspergillus antigen or antibody was positive in 8 (13%) and 43 (70%) patients, respectively. Oral itraconazole was used in 16 (26%) of patients, and surgical excision was performed in 15 (25%) patients. During hospitalization or after discharge, 19 (31 %) patients died.

SUMMARY AND CONCLUSION

Pulmonary aspergilloma usually occurs in elderly patients with old tuberculosis and respiratory failure. Many cases did not respond to antifungal therapy with itraconazole or amphotericin B. Our analysis indicates that more effective and appropriate therapeutic regimens are needed for the treatment of patients with pulmonary aspergilloma.

Amino acid residues of S-modulin responsible for interaction with rhodopsin kinase

S-modulin in frog or its bovine homologue, recoverin, is a 23-kDa EF-hand Ca(2+)-binding protein found in rod photoreceptors. The Ca(2+)-bound form of S-modulin binds to rhodopsin kinase (Rk) and inhibits its activity. Through this regulation, S-modulin is thought to modulate the light sensitivity of a rod. In the present study, we tried to identify the interaction site of the Ca(2+)-bound form of S-modulin to Rk. First, we mapped roughly the interaction regions by using partial peptides of S-modulin. The result suggested that a specific region near the amino terminus is the interaction site of S-modulin. We then identified the essential amino acid residues in this region by using S-modulin mutant proteins: four amino acid residues (Phe(22), Glu(26), Phe(55), and Thr(92)) were suggested to interact with Rk. These residues are located in a small closed pocket in the Ca(2+)-free, inactive form of S-modulin, but exposed to the surface of the molecule in the Ca(2+)-bound, active form of S-modulin. Two additional amino acid residues (Tyr(108) and Arg(150)) were found to be crucial for the Ca(2+)-dependent conformational changes of S-modulin.

Successful transplantation of a cadaveric kidney with post-infectious glomerulonephritis

This report describes a successful renal Tx in a patient with chronic renal failure, caused by dysplastic kidneys, who received a cadaveric kidney with post-infectious glomerulonephritis. Sequential renal biopsies were performed at 12 h before Tx, and at 1 h and on days 8 and 58 post-Tx. Post-operative hematuria disappeared on day 9 and proteinuria on day 13. Normal graft function was observed within 1 month, with histologic resolution. Our study suggests that while the donor kidney facilitates deposition of certain immune reactants, this is a host (environmental) problem and when transplanted into a new host (new environment), the problem is no longer sustained.

Calcium-dependent regulation of rhodopsin phosphorylation

Depending on ambient light conditions, a rod photoreceptor cell adapts to a light stimulus. For example, when it is kept in the light, its light sensitivity decreases because of light adaptation. The adaptational state is regulated by the Ca2+ concentration in the cytoplasm ([Ca2+]i). The [Ca2+]i is high in the dark and becomes low when the cell is light-adapted. The change in [Ca2+]i is detected by several Ca(2+)-binding proteins that change their conformations by binding Ca2+. S-modulin, found in frog rods, or its bovine homologue recoverin, is a 23 kDa Ca(2+)-binding protein that inhibits rhodopsin phosphorylation at high Ca2+ concentrations by inhibiting rhodopsin kinase. Since rhodopsin phosphorylation is an inactivating mechanism for light-activated rhodopsin (R*), the inhibition of this reaction will prolong the lifetime of R*. In this way, S-modulin is expected to increase the efficiency of phototransduction and therefore the light-sensitivity of rods in the dark. When rods are light-adapted, [Ca2+]i decreases so that the lifetime of the R* is expected to reduce, resulting in a decrease in light sensitivity. Even though it is generally agreed that S-modulin inhibits rhodopsin phosphorylation, its physiological function is not yet well understood.

Effect of caspase inhibitors on myocardial infarct size and myocyte DNA fragmentation in the ischemia-reperfused rat heart

OBJECTIVE

Caspase family proteases are recognized as key mediators of apoptosis. However, the role of caspases in the ischemia-reperfused heart remains uncertain. We evaluated the effect of caspase inhibitors on myocardial infarct size and the myocyte DNA fragmentation in the ischemia-reperfused rat hearts.

METHODS

Three groups of Sprague-Dawley rats (n = 7, each) were subjected to 30 min of ischemia followed by 6 h of reperfusion. One of the following drugs: (1) YVAD-aldehyde, a caspase-1-like protease inhibitor (3.5 mg/kg; YVAD), (2) DEVD-aldehyde, a caspase-3-like protease inhibitor (3.5 mg/kg, DEVD), (3) vehicle (140 microliters/kg) was administered intravenously 5 min prior to the ischemia in each group. Myocardial infarct size was defined by triphenyltetrazolium chloride (TTC) staining. Immunohistochemical staining by in situ nick end labeling (TUNEL) of cardiomyocytes and DNA electrophoresis were used for detecting DNA fragmentation. Ultrastructural analysis was done by electron microscopy. The caspase activity was measured in the myocardium of both groups.

RESULTS

The percentage of TUNEL-positive myocyte nuclei (%AP) was quantified by microscopy. A ladder pattern was detected by electrophoresis of DNA from the risk area and TUNEL-positive myocytes were seen in the risk area. The %AP was significantly reduced from 20 +/- 1% to 12 +/- 3% by YVAD and to 10 +/- 3% by DEVD (both P < 0.01). However, caspase inhibitors did not significantly change the infarct size. Electronmicrograph showed similar salcolemmal and mitochondrial damage in both group. The caspase activity was blocked by DEVD at 4 h after reperfusion.

CONCLUSION

Myocyte DNA fragmentation and caspase activation was inhibited by caspase inhibitors without reduction of the infarct size in ischemia-reperfused rat hearts.

Zonal organization of the ventral lateral geniculate nucleus in the cat: cholera toxin mapping

A zonal organization of the ventral lateral geniculate nucleus (LGNv) in the cat was studied with the bidirectional tracing method by using the subunit b of cholera toxin (CTb) as the marker. The prime objectives of the present study were to examine precise distribution of terminals of the retinal afferents to the LGNv, and to correlate it with the origins and terminations of the other central connections of the nucleus. The results obtained are summarized as follows: (1) the LGNv of the cat is divided into 3 zones according to the terminations of retinal afferents: lateral, intermediate, and medial; (2) the lateral zone receives afferents from the retina in which ipsi- and contralateral fibers terminate in a complementary fashion. According to the density of labeling of retinal terminals, the lateral zone is further divided into several areas. It also receives fibers from the visual related cortex; (3) the intermediate zone, which does not receive fibers from the retina nor the visual cortex, is reciprocally connected with the midbrain, primarily with the superficial layers of the superior colliculus (SC), and gives rise to thalamic projections to the nucleus centralis lateralis bilaterally; and (4) the medial zone, from which commissural fibers arise, receives afferents bilaterally from the retina, and sends fibers to the SC bilaterally. These results suggest that the LGNv of the cat has three different zones. Functional participation of each zone has been discussed.

Genetic analyses of visual pigments of the pigeon (Columba livia)

We isolated five classes of retinal opsin genes rh1(Cl), rh2(Cl), sws1(Cl), sws2(Cl), and lws(Cl) from the pigeon; these encode RH1(Cl), RH2(Cl), SWS1(Cl), SWS2(Cl), and LWS(Cl) opsins, respectively. Upon binding to 11-cis-retinal, these opsins regenerate the corresponding photosensitive molecules, visual pigments. The absorbance spectra of visual pigments have a broad bell shape with the peak, being called lambdamax. Previously, the SWS1(Cl) opsin cDNA was isolated from the pigeon retinal RNA, expressed in cultured COS1 cells, reconstituted with 11-cis-retinal, and the lambdamax of the resulting SWS1(Cl) pigment was shown to be 393 nm. In this article, using the same methods, the lambdamax values of RH1(Cl), RH2(Cl), SWS2(Cl), and LWS(Cl) pigments were determined to be 502, 503, 448, and 559 nm, respectively. The pigeon is also known for its UV vision, detecting light at 320-380 nm. Being the only pigments that absorb light below 400 nm, the SWS1(Cl) pigments must mediate its UV vision. We also determined that a nonretinal P(Cl) pigment in the pineal gland of the pigeon has a lambdamax value at 481 nm.

Evaluation of sandwich ELISA galactomannan test in samples of positive LA test and positive aspergillus antibody

OBJECTIVE

The detection of circulating Aspergillus galactomannan antigen is a useful tool for serodiagnosis of aspergillosis. However, the latex agglutination test for the detection of galactomannan is not completely reliable due to it's low sensitivity. The sandwich ELISA was developed to achieve high sensitivity.

MATERIALS

The sandwich immunocapture ELISA was evaluated by testing 56 sero-positive and 56 sero-negative samples of circulating galactomannan detected by LA test retrospectively.

RESULTS

Sixty of the samples were positive for galactomannan as measured by sandwich ELISA. Fifteen samples out of 56 samples negative by LA test were positive by ELISA and 4 samples out of 56 samples positive by LA test were negative by ELISA. Among 47 serum samples positive for anti-Aspergillus antibody, 14 samples were positive by ELISA.

CONCLUSION

In conclusion, galactomannan may be detected in more samples of by the new sandwich ELISA than by LA test.

Histological changes in the rat common carotid artery following simultaneous topical application of cotton sheet and cyanoacrylate glue

Histological changes in and around the arterial walls of rats were investigated following simultaneous topical application of cotton sheet and cyanoacrylate glue. The bilateral common carotid arteries were exposed using sterile techniques, and the test materials were applied to the right artery. The left artery served as a control. Changes in arterial histology were evaluated at 2 weeks, 1 month, 2 months, and 3 months after surgery. Extensive inflammation consisting primarily of histiocytes and multinuclear giant cells was observed around the materials, but tended to decrease by 3 months. Necrosis in the media and fibrosis in the adventitia initially appeared around 2 weeks, and became advanced by 2-3 months. At 2-3 months, disruption of elastic fibers and marked fibrosis in the media were seen, and endothelial proliferation in the intima appeared. Intimal proliferation was observed at both the experimental and other sites of the vessels. The present results suggest that simultaneous use of the test materials can cause the arterial occlusive lesions observed following aneurysmal surgery.

Arginine-55 in the beta-arm is essential for the activity of DNA-binding protein HU from Bacillus stearothermophilus

DNA-binding protein HU (BstHU) from Bacillus stearothermophilus is a homodimeric protein which binds to DNA in a sequence-nonspecific manner. In order to identify the Arg residues essential for DNA binding, four Arg residues (Arg-53, Arg-55, Arg-58, and Arg-61) within the beta-arm structure were replaced either by Gln, Lys, or Glu residues, and the resulting mutants were characterized with respect to their DNA-binding activity by a filter-binding analysis and surface plasmon resonance analysis. The results indicate that three Arg residues (Arg-55, Arg-58, and Arg-61) play a crucial role in DNA binding as positively charged recognition groups in the order of Arg-55 > Arg-58 > Arg-61 and that these are required to decrease the dissociation rate constant for BstHU-DNA interaction. In contrast, the Arg-53 residue was found to make no contribution to the binding activity of BstHU.