Current understanding of subjective tinnitus in adults

PURPOSE

An up-to-date overview of epidemiology, etiology and pathophysiological mechanisms, diagnostic and evaluation methods, current treatment status and future directions of subjective tinnitus in adults.

METHODS

Review of current evidence-based literature on subjective tinnitus in adults.

RESULTS

The prevalence of subjective tinnitus in the adult population is estimated to be around 14%, and it tends to increase with age. Subjective tinnitus is a complex condition with multiple factors contributing to its origin. However, the exact causes and underlying mechanisms remain unknown. Potential causes may include hearing loss, dysfunction in the somatosensory system, and auditory cortical dysfunction, although severe underlying pathology is rare. Currently, diagnosis primarily relies on patient self-reported medical history and physician-based clinical assessment due to the lack of objective testing. Various treatment and management options have been proposed, but their effectiveness varies, and there is no universally agreed-upon treatment option.

CONCLUSIONS

Tinnitus is a complex and heterogeneous disease with a high incidence rate and a tendency to increase with age. A holistic perspective is needed to understand the generation, perception, and emotional responses to tinnitus. Diagnosis requires a comprehensive assessment based on medical history and relevant examinations, identification of concurrent psychosomatic comorbidities, and active pursuit of objective diagnostic methods. At the same time, on the basis of existing treatment plans and combining emerging technologies, we will develop new personalized, precise, and combined treatment plans.

[Pregnancy outcomes in patients with adenomyosis with fertility requirements: retrospective analysis of clinical data from real world]

Objective: To retrospectively analyze the pregnancy outcomes of patients with adenomyosis requiring fertility in a single center under real world condition. Methods: From June 2015 to May 2020, 231 cases of pregnancy complicated with adenomyosis diagnosed by ultrasound with fertility requirements were treated in the Women's and Children's Hospital Affiliated to Qingdao University with complete clinical data. And they were divided into three groups according to the treatment of adenomyosis before pregnancy: expectation group, drug group and operation group. The relevant data before pregnancy of the three groups were analyzed, and the pregnancy outcomes of the patients were summarized. According to whether the early pregnancy was treated with medication, the patients who were naturally conceived without symptoms of threatened abortion were divided into observation group and fetus protection group, and the pregnancy outcomes of the two groups were compared. Results: (1) Compared with the expectation group, the ages of patients in the drug group and the operation group were larger [(31.5±1.8) vs (34.1±3.7) vs (36.9±3.6) years old], and the difference was statistically significant (P<0.05). Only 9 patients (11.5%, 9/78) had clinical symptoms in the expectation group, while the patients in the drug group and the operation group had a higher proportion of dysmenorrhea and increased menstrual volume. The uterine volume of the drug group and the operation group were larger than that of the expectation group [(151±46) vs (166±27) vs (97±18) cm³], the difference was statistically significant (P<0.05). 78.6% (33/42) of the operation group were focal adenomyosis. The proportion of natural pregnancy in the expectation group was 97.4% (76/78), and in vitro fertilization and embryo transfer was mainly used in the drug group and the operation group. (2) The abortion rates of the three groups were 48.7% (26/111), 4/17, 67.5% (27/78) respectively. Compared with the drug group and the operation group, the preterm birth rate was lower [55.9% (33/111) vs 11/17 vs 12.5% (5/78)] and the natural delivery rate was higher [44.1% (26/111) vs 4/17 vs 67.5% (27/78)] in the expectation group. (3) There were 89 cases of spontaneous pregnancy without threatened abortion symptoms, including 31 cases in the observation group and 58 cases in the fetus protection group. Compared with the observation group, the abortion rate of patients in the fetus protection group was lower [41.9% (13/31) vs 34.5% (20/58)], and the difference was statistically significant (P<0.05). Conclusions: Patients with adenomyosis who have fertility requirements should be comprehensively evaluated and individualized treatment plans should be given. Pregnancy patients with adenomyosis have a high rate of miscarriage, and they should be included in the management of high-risk pregnant women. Active fetal protection treatment during early pregnancy might improve pregnancy outcomes.

Nanoparticle-based delivery of an anti-proliferative metal chelator to tumor cells

This paper describes the preparation and characterization of polymeric nanoparticles loaded with a potent anti-tumor metal chelator, Di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT) for delivery to cancer cells. Metal chelators have been increasingly studied for their anti-cancer properties that rely on the high demand of neoplastic cells for iron. Dp44mT has previously shown great antiproliferative characteristics in several cancers including breast cancer and melanoma. To further expand the application of this highly cytotoxic agent for cancer treatment and to enable its specific delivery to malignant cells, here we apply nano-scale particles (NPs) of biodegradable poly(lactic-co-glycolide) (PLGA) for encapsulation of Dp44mT and evaluate its effectiveness in vitro. The results demonstrated that Dp44mT was efficiently encapsulated in PLGA particles. Resulting NPs were uniform in size and shape and had good colloidal stability. Moreover, Dp44mT encapsulation in PLGA enhanced the water solubility of this agent. Lastly, the present formulation showed high level of cytotoxicity in glioma cells. Together, these results show the potential of PLGA NPs as a nano-carrier for Dp44mT with no apparent impact on the anti-tumor activity of this compound.

Rapidly progressive non-alcoholic fatty liver disease due to hypopituitarism. Report of 5 cases

BACKGROUND

A few reports had revealed the clinical associations between hypopituitarism and non-alcoholic fatty liver disease (NAFLD). Further evidences were needed.

OBJECTIVES

To report 5 cases of young patients with rapidly progressive NAFLD in conjunction with hypopituitarism, aiming to detect the associations.

METHODS

Clinical data of the 5 patients were analyzed retrospectively. All had decompensated liver cirrhosis that was finally attributed to NAFLD. Hypopituitarism was a result of pituitary stalk interruption syndrome in 3 patients and craniopharyngioma in 2.

RESULTS

4 patients were overweight (BMI, 24.2 to 28.4kg/m2). All had insulin resistance (HOMA-IR, 4.8 to 7.2). All suffered from at least one metabolic disorder. All had decompensated liver cirrhosis. The average time duration was 6.9 years between the onset of abnormal liver function and decompensated liver cirrhosis. Fatty liver could be detected in all patients. All had anterior hypopituitarism, and 2 also had posterior pituitary dysfunction. The hormone supplements were insufficient.

CONCLUSION

Hypopituitarism may be a rare cause of rapidly progressive NAFLD. Insulin resistance and metabolic disorders caused by multiple hormonal deficiencies may contribute to it. Hormone supplement therapy, especially the growth hormone supplement, should be given at the early age to prevent the severe liver disease.

Abstract P6-07-19: An alteration of hormonal receptor status throughout tumor progression related to prognosis in breast cancer patients

Purpose

We aimed to identify whether hormonal receptors change throughout tumor progression, because this may influence management and influence prognosis in breast cancer patients.

Patients and Methods

From the institution's database, we collected data of 963 patients who developed relapse during their follow-ups. To determine estrogen receptor(ER) and progesterone receptor (PR), we retrospectively reviewed immunohistochemical(IHC) results in both primary and relapsed tumors.

Results

Among a total of 963 patients, 280 and 683 patients experienced locoregional relapse only and distant metastasis irrespective of locoreginal relapse, respectively. ER in 650 patients and PR in 590 patients from both primary tumor and relapse were identified, revealing a change in 157 (24.2%) and 154 (26.1%) patients, respectively. In patients with distant metastasis, assessment of ER and PR showed an alteration in 86 and 56 patients, respectively. The overall survival related to the change of ER and PR status in primary tumor and relapse was significantly different (log rank, P&lt;0.001 in both ER and PR status). In addition, women with hormone receptors negative primary tumors that changed to hormone receptors positive tumors who received anti-hormonal therapy after relapse showed a statistically significant good overall survival (p&lt;0.001) compared with women who had constant ER-negative tumors.(cox regression, hazard ratio 2.32 ; 95% CI, 1.91 to 3.01)

Conclusion

The breast cancer showed alterations of hormone receptor status throughout tumor progression, hat were related to the strategy of treatment and significantly influences survival. Therefore, investigations of hormone receptor at relapse are essential and helpful in breast cancer patient management.

Citation Format: Lee E-S, Kim J, Yoo T-K, Kim Y, Han J, Kang YJ, Choi J, Rhu J, Lee H-B, Han W, Noh D-Y, Moon H-G. An alteration of hormonal receptor status throughout tumor progression related to prognosis in breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-19.

Abstract P5-08-23: Ki-67 expression is not a valuable predictive prognostic factor when progesterone receptor expression is high in estrogen receptor-positive breast cancer

Background

Immunohistochemistry markers are recognized as a predictive prognostic factor for women with breast cancer. Ki-67 and progesterone receptor (PgR) expression are reported to be independently associated with breast cancer prognosis. Some studies report high Ki-67 expression as a negative predictive marker. Whereas other studies report tendency of similar survival between high and low Ki67 cancers when PgR expression is high. In this study, we examined the prognostic significance of Ki-67 expression under PgR expression status.

Methods

The records of 2,366 patients were retrospectively reviewed. The patients underwent surgery for primary breast cancer from July 2009 to December 2012 at a single institution. We studied the prognostic significance of Ki-67 expression under PgR expression. We used 20% and 10% as the cut-off value for PgR and Ki-67, respectively. The end point was recurrence-free survival (RFS) evaluated by use of Kaplan-Meier analysis.

Result

Of the 2,366 analyzed patients, the median follow-up time was 43 months. During follow-up, 44 patients had recurrence, loco-regional recurrence developed in 23 patients and distant recurrence developed in 21 patients. In patients with low PgR expression, high Ki-67 expression group showed significantly worse prognosis compared to low Ki-67 expression group (p=0.005). On the other hand, no significant difference was shown between low and high Ki-67 expression group when PgR expression was high (p=0.637). Also multivariate analysis demonstrated that high Ki-67 expression was an independent prognostic factor only when PgR expression was low. (95% confidence interval [CI], 1.35-10.48; p=0.011)

Conclusion

This is the largest reported study that prognostic significance of Ki-67 expression is defined by PgR expression. Our study presents that high Ki-67 expression is inversely correlated with recurrence risk in early breast cancer patients only under low PgR expression. At high PgR expression, Ki-67 expression has no influence on breast cancer prognosis. Therefore, attention should be paid to correlation between PgR and Ki-67 expression.

Citation Format: Han JH, Kang YJ, Han W, Lee H-B, Kim Y, Yoo T-K, Moon H-G, Noh D-Y. Ki-67 expression is not a valuable predictive prognostic factor when progesterone receptor expression is high in estrogen receptor-positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-23.

Abstract P6-04-02: Identification of ESR1 splice variants associated with prognosis in estrogen receptor positive breast cancer

Background: Splice variants play a major role in carcinogenesis and disease progression. It is well known that androgen receptor splice variants are associated with resistance to prostate cancer treatment. Estrogen receptor (ER)-positive breast cancers constitute about 70% of all breast cancers and have better prognosis compared to ER-negative cancers. However, there are ER-positive breast cancers that acquire resistance to anti-estrogen therapy, and 12-55% of those tumors were shown to possess ESR1 mutations. The aim of this study was to identify common splice variants in the ESR1 gene and investigate their association with disease outcome.

Methods: Whole transcriptome sequencing was performed on breast cancer specimens from 120 invasive breast cancer patients who underwent operation at Seoul National University Hospital (SNUH) and data from SNUH, GEO, and The Cancer Genome Atlas (TCGA) was used for normal breast tissue sequencing. Exon-exon junctions were identified on aligned RNA sequencing data and was used to construct exon graphs. Splice variant candidates were selected from exon graphs and were merged according to variant subtypes of samples. Subtypes were accessed differentially in relation to how frequent the junctions appear in tumor samples and common exon skipping types with frequent junctions were identified. TCGA RNA sequencing data was then used to search for the common exon skipping subtypes detected from SNUH RNA sequencing data.

Results: Of the 120 tumor samples, 50 were clinically ER-positive by immunohistochemistry. Among exon paths logically possible, 125 paths were not observed in normal breast tissues. Exon 4-5 junction was the most commonly observed junction in the tumor samples. In a search for exon skipping type that results in missing ligand-binding domain of ER, three exon skipping types were identified. Exon skipping with exon 5-10 junction (type 1), exon 9-12 junction (type 2), and exon 10-12 (type 3) was seen in 4 (8%), 4 (8%), and 10 (20%) ER-positive samples, respectively. Retrospective medical chart review of the 18 patients showed recurrence in 4 (100%), 2 (50%), and 4 (40%) patients with type 1, 2, and 3 exon skipping, respectively. Evaluation of TCGA RNA sequencing data of 872 ER-positive samples suggested exon 4-5 junction as the most common junction. A search for exon skipping types in TCGA revealed 1 (0.1%), 9 (1.0%), and 454 (52.1%) samples with type 1, 2, and 3 exon skipping, respectively. However, none of the patients with type 1 or 2 had metastasis or had expired. Of the 454 patients with type 3 exon skipping, 54 patients had died, constituting 61.4% of 88 mortalities in the whole ER-positive population.

Conclusion: Certain splice variants of ESR1 gene yields exon skipping subtypes commonly observed in the ER-positive breast cancer. Estrogen receptor-positive breast cancer with these exon skipping types resulting in a missing ligand-binding domain of ER may be associated with poorer disease outcome. Further investigation is warranted to validate the role of ESR1 exon skipping subtypes in the disease progression of breast cancer.

Citation Format: Lee H-B, Han W, Ko S, Kim M-S, Lim S, Lee K-M, Kang YJ, Han JH, Kim Y, Yoo T-K, Moon H-G, Noh D-Y, Kim S, Han W. Identification of ESR1 splice variants associated with prognosis in estrogen receptor positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-04-02.

Abstract P2-02-15: Discovery of putative circulating tumor cells through somatic mutation profile of epithelial cell adhesion molecule positive single cells from blood of metastatic breast cancer patients

Background: Circulating tumor cell (CTC) enumeration provides prognostic information for chemotherapy in metastatic breast cancer. However, due to its rarity and heterogeneity, it is difficult to distinguish true CTCs from normal blood cells and perform genomic analysis on them for use in therapeutic strategies. The main application of most currently available CTC detection systems consists of an enumeration of putative CTCs without further analysis. The aim of this study was to evaluate the feasibility of single cell picking and target sequencing of epithelial cell adhesion molecule (EpCAM)-positive cells for detecting CTCs.

Methods: Whole blood sampled from metastatic breast cancer patients who were newly diagnosed with metastasis or who had disease progression during palliative treatment were used for this study. After applying IsoFlux Circulating Tumor Cell Enrichment Kit (Fluxion, South San Francisco, CA, USA), single CTC candidates were picked from a pool of EpCAM-positive cells. Genomic DNA from the picked cells was whole genome amplified and target sequencing was performed using Ion AmpliSeq™ Cancer Hotspot Panel (Life Technologies, Carlsbad, CA, USA). Target sequencing reads were mapped to human genome reference (hg19) using BWA-MEM (0.7.10). Single nucleotide variants (SNVs) were annotated using dbSNP, Variome Data 0.2, and COSMIC databases.

Results: A total of 172 EpCAM-positive cells were selected according to size and EpCAM status from whole blood of 11 patients. The remaining cells were grouped into a pooled sample for each patient. The mean read depth of the target genes was 13455×. A mean 7.82 mutations as determined by SNVs listed in the COSMIC database but not in dbSNP and Variome Data 0.2 were detected in each patient. Cells with multiple mutated genes, or those with a mutated gene repeatedly observed in another cell from the same patient were judged to be putative CTCs. At least 2 putative CTCs were detected in 7 patients while no CTCs were detected in 2 patients. Mutated genes observed in the putative CTCs were ABL1, AKT1, APC, CDH1, CDKN2A, ERBB2, FGFR3, HRAS, IDH1, JAK2, KDR, NPM1, RB1, RET, SMARCB1, STK11, and TP53.

Conclusions: Potential CTCs were successfully identified by single cell picking and target sequencing of EpCAM-positive cells from whole blood of metastatic breast cancer patients. Unique mutations not detected in other single cells and pooled samples can be used to distinguish putative CTCs from normal cells. Genomic profiling of corresponding primary tumor and metastatic site biopsy is warranted to verify the CTCs and investigate their role in disease progression.

Citation Format: Lee H-B, Jeon S, Kim BC, Jho S, Kim J, Kang YJ, Yoo T-K, Han JH, Kim Y, Im S-A, Moon H-G, Noh D-Y, Han W. Discovery of putative circulating tumor cells through somatic mutation profile of epithelial cell adhesion molecule positive single cells from blood of metastatic breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-15.

Genetic diversity and taxonomic status of Gymnocypris chilianensis based on the mitochondrial DNA cytochrome b gene

In order to study the genetic diversity and taxonomic status of Gymnocypris chilianensis on a molecular level, the mitochondrial DNA cytochrome b gene was sequenced for 74 individuals of G. chilianensis from two locations (Heihe River and Shule River) and 42 individuals of its affinis species Gymnocypris przewalskii. Analyses of genetic diversity and sequence differences were conducted for these samples, combined with the analysis of 30 homologous sequences of another affinis species Gymnocypris eckloni, which were downloaded from GenBank. The results showed that both the haplotype diversity (h = 0.9820) and nucleotide diversity (π= 0.0039) of the Shule River G. chilianensis were lower than the other populations, thus, the Shule River G. chilianensis should be prioritized for protection because of its lower genetic diversity level. The results of sequence analysis showed that the genetic distance between the Heihe River G. chilianensis population and the Shule River G. chilianensis population was 0.0064, and the genetic distance between these two populations and the G. przewalskii population was 0.0838 and 0.0810, respectively. The genetic distance between the two G. chilianensis populations and the G. eckloni population was 0.0805 and 0.0778, respectively. Analysis of sequence differences indicates that G. chilianensis is sufficiently diverged from G. przewalskii and G. eckloni to the extent that it has reached species level, thus, G. chilianensis can be considered an independent species of Gymnocypris.

The relationship between mast cell density and tumour grade in transitional cell carcinoma of the bladder

This study investigated the relationship between mast cell numbers and the grade of bladder transitional cell carcinoma (TCC). Bladder TCC biopsies were obtained via transurethral resection and 45 stage T1 specimens were included in the study. Specimens were sorted into two groups, low grade (grade I) and high grade (grades II and III). Samples were stained using haematoxylin and eosin, toluidine blue and immunohistochemical staining for tryptase. Mast cells were examined by light microscopy and cell density was recorded. Mast cell density was significantly higher in high-grade TCC than low-grade TCC. There was also a significant relationship between the number of mast cells identified using toluidine blue staining or immunohistochemical staining for tryptase. Detailed studies of mast cell function will enable the development of more effective antitumour therapies via mast cell manipulation.

Molecular cloning and characterization of the STAT gene in Hyphantria cunea haemocytes

A new insect member of the signal transducer and activator of transcription (STAT) family of transcription factors, Hyphantria cunea STAT (HcSTAT), was cloned from the lepidopteran H. cunea. The domain involved in DNA interaction and the Src homology 2 (SH2) domain were well conserved. During all developmental stages, the gene was expressed at a low level in the haemocytes, fat body cells, midgut, epidermis and Malpighian tubules. The haemocytes and Malpighian tubules showed transcriptional activation of HcSTAT upon Gram-negative and Gram-positive bacterial challenges. These challenges increased the induction and nuclear translocation of the HcSTAT protein that recognizes a STAT target site in H. cunea haemocytes. In vivo treatment with sodium orthovanadate translocated HcSTAT to the haemocyte nucleus. This study shows the involvement of the haemocyte Janus kinase/STAT pathway after microbial infection in lepidopteran insects.

Treatment guidelines for isolated dissection of the superior mesenteric artery based on follow-up CT findings

OBJECTIVES

The treatment guidelines for isolated superior mesenteric artery dissection (SMAD) are not well established. The purpose of this study was to report a single-centre series of SMAD and propose treatment guidelines.

MATERIALS AND METHODS

Between November 2004 and December 2009, 30 patients were diagnosed with SMAD. We retrospectively reviewed their medical records.

RESULTS

The subjects included 26 men and four women, with a mean age of 55.1 years. The chief complaint was abdominal pain in 17 patients, whereas 13 patients were asymptomatic. The mean follow-up was 38.3 months. The radiographic findings included intimal flap with a false lumen in 20 patients and intramural haematoma in 10 patients. The treatments included observation in 18 patients, anticoagulation in five patients, stenting in six patients and surgery in one patient. During follow-up (mean 15.6 months), there was no change in the computed tomography scans of seven patients, improvement was observed in four patients and complete resolution was observed in four patients. All patients, including the symptomatic patients, remained asymptomatic during follow-up.

CONCLUSIONS

Most patients with SMAD can be successfully managed with conservative treatment. Surgical treatment or percutaneous intervention can be reserved for patients with severe mesenteric ischaemia and those for whom the initial conservative treatment fails.

Multiple copies of 16s rRNA gene affect the restriction patterns and DGGE profile as revealed by analysis of genome database

The use of 16S rRNA gene has been a "golden" method to determine the diversity of microbial communities in environmental samples, phylogenetic relationships of prokaryotes and taxonomic position of newly isolated organisms. However due to the presence of multiple heterogeneous 16S rRNA gene copies in many strains, the interpretation of microbial ecology via 16S rRNA sequences is complicated. Purpose of present paper is to demonstrate the extent to which the multiple heterogeneous 16S rRNA gene copies affect RFLP patterns and DGG E profiles by using the genome database. In present genome database, there are 782 bacterial strains in total whose genomes have been completely sequenced and annotated. Among the total strains, 639 strains (82%) possess multiple 16S rRNA gene copies, 415 strains (53%) whose multiple copies are heterogeneous in sequences as revealed by alignment, 236 strains (30%) whose multiple copies show different restrict patterns by CSP61 + Hinfl, MspI + Rsal or HhaI as analyzed in silico. Polymorphisms of the multiple copies in certain strains were further characterized by G + C% and phylogentic distances based on the sequences of V3 region, which are linked to DGGE patters. Polymorphisms of a few strains were shown as examples. Using artificial communities, it is demonstrated that the presence of multiple heterogeneous 16S rRNA gene copies potentially leads to over-estimation of the diversity of a community. It is suggested that care must be taken when interpreting 16S rRNA-based RFLP and DGGE data and profiling an environmental community.

Sequence analysis of an isolate of minute virus of canines in China reveals the closed association with bocavirus

In the present study, we have cloned and sequenced the nearly-full-length genome of minute virus of canines (MVC), SH26, in China. The genome of MVC, 5,132 nucleotides (nts) in length, contains three open reading frames (ORFs), which are 2,325-bp of NS1, 561-bp of NP1 and 2,112-bp of VP1/VP2 encoding three proteins of 774, 186 and 703 residues, respectively. Predicted amino acids sequence of NS1 of MVC has 44% identity with human bocavirus (HBoV) and human boacvirus 2 (HBoV2), NP1 has 48 and 45% identity with HBoV and HBoV2, VP1/VP2 has 45 and 46% identity with HBoV and HBoV2, respectively. Phylogenetic analysis showed that the present Chinese MVC strain was also closely clustered with the previous American and Japanese MVC isolates, and MVCs formed a different branch together with bovine parvovirus and HBoVs from other parvoviruses classified into Parvovirinae.

Comparative analysis of two attacin genes from Hyphantria cunea

A full-length clone corresponding to attacin was isolated from a cDNA library made from fat body of immunized Hyphantria cunea larvae. This newly isolated attacin B shows characteristics different from those previously reported for attacin A. The two attacin cDNAs encode precursor proteins of 233 and 248 amino acid residues, respectively. The two attacins show 45.9% identity at the amino acid level, and 35.2% identity at the nucleotide level. Attacins A and B of H. cunea show significant identities with the attacins of Lepidoptera. Attacin B is a typical glycine-rich protein, while attacin A is leucine-rich. Attacin B is expressed from last instar larvae to adult, while attacin A showed stage-specific expression during the prepupal and pupal stages. Attacins A and B are predicted to have different secondary structure in that attacin A has no tendency to form helices but attacin B contains a substantial number of helices. Attacin A is induced at a trace level in infected larvae, while attacin B is strongly induced against Gram-positive and negative bacteria, fungi, and viruses. The attacin B transcripts were detected in fat body, epidermis and hemocytes after injection with Escherichia coli, Citrobacter freundii, or Candida albicans, but not in the midgut and Malpighian tubule. Recombinant attacin A showed no antibacterial activity, while recombinant attacin B showed strong antibacterial activity in proportion to the amount of the protein injected.

The anti-diabetic effects of ethanol extract from two variants of Artemisia princeps Pampanini in C57BL/KsJ-db/db mice

The anti-diabetic effects of two variants of Artemisia princeps Pampanini, sajabalssuk (SB) and sajuarissuk (SS), were investigated in type 2 diabetic animal using their ethanol extracts. Male C57BL/KsJ-db/db (db/db) mice were divided into control, SB ethanol extract (SBE), SS ethanol extract (SSE), or rosiglitazone (RG) groups and their age-matched littermates (db/+) were used. Supplementation of the SBE (0.171 g/100g diet), SSE (0.154 g/100g diet), and RG (0.005 g/100g diet) improved glucose and insulin tolerance and significantly lowered blood glycosylated hemoglobin levels, as compared to the control group. Plasma insulin, C-peptide and glucagon levels in db/db mice were higher in the db/+ mice, however these values were significantly lowered by SBE, SSE or RG-supplement. Hepatic GK activity was significantly lower in the db/db mice than in the db/+ mice, while hepatic G6Pase activity was vice versa. Supplementation of SBE, SSE and RG reversed these hepatic glucose-regulating enzyme activities. In addition, SBE and SSE markedly increased the hepatic glycogen content and muscle ratio as compared to the control group, but they did not alter the food intake, body weight and plasma leptin level. The RG group, however, showed a significant increase in the food intake, body weight and plasma leptin. These results suggest that SBE and SSE exert an anti-diabetic effect in type 2 diabetic mice.

Oxidative stress and diabetic cardiomyopathy: a brief review

Diabetes is a serious public health problem. Improvements in the treatment of noncardiac complications from diabetes have resulted in heart disease becoming a leading cause of death in diabetic patients. Several cardiovascular pathological consequences of diabetes such as hypertension affect the heart to varying degrees. However, hyperglycemia, as an independent risk factor, directly causes cardiac damage and leads to diabetic cardiomyopathy. Diabetic cardiomyopathy can occur independent of vascular disease, although the mechanisms are largely unknown. Previous studies have paid little attention to the direct effects of hyperglycemia on cardiac myocytes, and most studies, especially in vitro, have mainly focused on the molecular mechanisms underlying pathogenic alterations in vascular smooth-muscle cells and endothelial cells. Thus, a comprehensive understanding of the mechanisms of diabetic cardiomyopathy is urgently needed to develop approaches for the prevention and treatment of diabetic cardiac complications. This review provides a survey of current understanding of diabetic cardiomyopathy. Current consensus is that hyperglycemia results in the production of reactive oxygen and nitrogen species, which leads to oxidative myocardial injury. Alterations in myocardial structure and function occur in the late stage of diabetes. These chronic alterations are believed to result from acute cardiac responses to suddenly increased glucose levels at the early stage of diabetes. Oxidative stress, induced by reactive oxygen and nitrogen species derived from hyperglycemia, causes abnormal gene expression, altered signal transduction, and the activation of pathways leading to programmed myocardial cell deaths. The resulting myocardial cell loss thus plays a critical role in the development of diabetic cardiomyopathy. Advances in the application of various strategies for targeting the prevention of hyperglycemia-induced oxidative myocardial injury may be fruitful.

Zinc inhibition of caspase-3 activation does not protect HeLa cells from apoptotic cell death

Zinc is proposed to be antiapoptotic for it has been shown to inhibit late events of apoptotic pathways such as Ca(2+)/Mg(2+)-dependent endonuclease cleavage of chromatin DNA, poly-ADP ribose polymerase cleavage, and caspase-3 activity. Because caspase-3 is a critical executioner caspase in apoptosis, this study was undertaken to examine specifically a correlation between zinc inhibition of caspase-3 activation and apoptosis in HeLa cells. Cultured HeLa cells were exposed to 100 microM ZnCl(2) for 1 h prior to 12 h treatment with 1.0 microM doxorubicin (DOX), an important anticancer agent that causes apoptosis in a wide variety of tumor cells. Western blot analysis of HeLa cells treated with DOX for 12 h revealed that DOX caused proteolytic activation of caspase-3 and zinc inhibited this activation. Interestingly, zinc did not inhibit DOX-induced apoptosis as measured by a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Furthermore, a microculture tetrazolium assay confirmed that cell death occurred in the presence of zinc. These results demonstrate that zinc specifically inhibits DOX-induced activation of caspase-3 in HeLa cells, but does not suppress DOX-induced apoptosis or otherwise cell death, thus suggesting DOX-induced caspase-3 activation may not play a major role in overall cell death and/or non-caspase-3 pathways are involved in DOX-induced apoptosis in HeLa cells.

Metallothionein inhibits doxorubicin-induced mitochondrial cytochrome c release and caspase-3 activation in cardiomyocytes

Previous studies using transgenic mice in which metallothionein (MT) was overexpressed only in the heart have demonstrated that MT protects from oxidative cardiac injury induced by doxorubicin (DOX), an important anticancer agent. MT cardioprotection is associated with its antiapoptotic effect. The present study was undertaken to test the hypothesis that MT suppresses DOX-induced apoptosis through inhibition of mitochondrial cytochrome c release and caspase-3 activation. Primary cultures of cardiomyocytes isolated from the hearts of transgenic neonatal mice and nontransgenic controls were treated with DOX at a clinically relevant concentration (1.0 microM) for varying time periods. Apoptosis was detected in nontransgenic cardiomyocyte cultures by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and Annexin V-fluorescein isothiocyanate binding. This apoptotic effect was significantly suppressed in the MT-overexpressing transgenic cardiomyocytes. Western blot analysis revealed that DOX caused mitochondrial cytochrome c release. Furthermore, caspase-3 activation was observed. The activation of this apoptotic pathway by DOX was dramatically inhibited in the MT-overexpressing cardiomyocytes. To elucidate the role of reactive oxygen species (ROS) in the activation of the cytochrome c-mediated caspase-3 activation pathway, the intracellular levels of ROS and their localization were detected by fluorescent confocal microscopy. Mitochondrial ROS concentrations were dramatically elevated by DOX in nontransgenic cardiomyocytes. This elevation was completely inhibited almost in the MT-overexpressing cardiomyocytes. Thus, these results demonstrate that MT suppresses DOX-induced apoptosis in cardiomyocytes through, at least in part, inhibition of the cytochrome c-mediated apoptotic pathway.

The predictive parameters of erythropoietin hyporesponsiveness in patients on continuous ambulatory peritoneal dialysis

BACKGROUND

The present study was aimed at investigating the predictive parameters of erythropoietin (epoetin) hyporesponsiveness in patients on continuous ambulatory peritoneal dialysis (CAPD).

METHODS

We studied 40 patients with end-stage renal disease who had been receiving CAPD for at least 6 months and epoetin therapy for at least more than 2 months. Pearson's simple correlation and multiple stepwise linear regression analysis was used to discover what parameter can predict epoetin resistance. We expressed epoetin resistance index (ERI) as weekly epoetin dose/hematocrit/body weight'. The dose of epoetin is titrated by about 25% every 2 to 4 weeks to maintain a target hematocrit level between 33% and 36%.

RESULTS

We analyzed the relationship between ERI and other predictive parameters by Pearson's correlation. These results showed ERI has a statistically significant correlation with transferrin saturation (TS) (r = -0.327, p = 0.042), total weekly Kt/Vurea (r = -0.423, p = 0.018), serum albumin level (r = -0.458, p = 0.003), normalized protein catabolic rate (nPCR) (r = -0.479, p = 0.006), normalized protein equivalent of total nitrogen appearance (nPNA) (r = -0.488, p = 0.005) and serum C-reactive protein (CRP) (r = 0.332, p = 0.036). Regression analysis was performed using stepwise linear regression for multiple variables to discover the most independent variable which is correlated with ERI. ERI was entered as a dependent variable, whereas the other parameters (age, duration of peritoneal dialysis, serum albumin level, CRP, serum ferritin, total weekly Kt/Vurea, nPCR, nPNA, serum iPTH, serum aluminium, TS) were entered as independent variables. This analysis showed CRP is the most significant variable and, if CRP is excluded, nPNA is the significant variable. CRP has a statistically significant correlation with serum albumin level (r = -0.418, p = 0.007) and total weekly Kt/Vurea (r = -0.366, p = 0.043). High CRP group has more increased level of ERI (p < 0.05), age (p < 0.05) and serum creatinine level (p < 0.05) than normal control, but more decreased level of serum albumin (p < 0.01) and serum iron levels (p < 0.05).

CONCLUSION

These results indicate that CRP is the most important predictor of epoetin hyporesponsiveness.

Inhibition of hypoxia/reoxygenation-induced apoptosis in metallothionein-overexpressing cardiomyocytes

To study possible mechanisms for metallothionein (MT) inhibition of ischemia-reperfusion-induced myocardial injury, cardiomyocytes isolated from MT-overexpressing transgenic neonatal mouse hearts and nontransgenic controls were subjected to 4 h of hypoxia (5% CO2-95% N2, glucose-free modified Tyrode's solution) followed by 1 h of reoxygenation in MEM + 20% fetal bovine serum (FBS) (5% CO2-95% air), and cytochrome c-mediated caspase-3 activation apoptotic pathway was determined. Hypoxia/reoxygenation-induced apoptosis was significantly suppressed in MT-overexpressing cardiomyocytes, as measured by both terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling and annexin V-FITC binding. In association with apoptosis, mitochondrial cytochrome c release, as determined by Western blot, was observed to occur in nontransgenic cardiomyocytes. Correspondingly, caspase-3 was activated as determined by laser confocal microscopic examination with the use of FITC-conjugated antibody against active caspase-3 and by enzymatic assay. The activation of this apoptotic pathway was significantly inhibited in MT-overexpressing cells, as evidenced by both suppression of cytochrome c release and inhibition of caspase-3 activation. The results demonstrate that MT suppresses hypoxia/reoxygenation-induced cardiomyocyte apoptosis through, at least in part, inhibition of cytochrome c-mediated caspase-3 activation.

Attenuation of doxorubicin chronic toxicity in metallothionein-overexpressing transgenic mouse heart

Previous studies have shown that cardiac-specific metallothionein (MT)-overexpressing transgenic mice are highly resistant to acute cardiotoxicity induced by doxorubicin (DOX), a most effective anticancer agent. However, cumulative dose-dependent chronic cardiotoxicity attributable to long-term administration of DOX is a significant clinical problem. Because MT is a potent antioxidant and oxidative stress is critically involved in DOX-induced heart injury, the present study was undertaken to test the hypothesis that MT also provides protection against DOX chronic cardiotoxicity. Transgenic mice containing high levels of cardiac MT and nontransgenic controls were treated with a cumulative dose of 40 mg/kg of DOX in 10 equal i.v. injections over a period of 7 weeks. Three weeks after the last injection, the mice were killed for an analysis of cardiotoxicity. As compared with nontransgenic controls, DOX-induced cardiac hypertrophy was significantly inhibited in the transgenic mice. Light microscopic examination revealed that DOX-induced myocardial morphological changes were markedly suppressed or almost eliminated in the transgenic mice. Under electron microscopy, extensive sarcoplasmic vacuolization and severe disruption of mitochondrial fine structure were observed in nontransgenic cardiomyocytes, but almost no sarcoplasmic vacuolization was observed, and the mitochondrial structural changes were almost completely prevented in the transgenic cardiomyocytes. The results thus indicate that MT elevation is a highly effective approach to prevent chronic cardiomyopathy attributable to DOX. This study also suggests that oxidative stress is critically involved in the DOX-induced chronic cardiotoxicity.

Molecular and cellular mechanisms of cardiotoxicity

Cardiotoxicity resulting from detrimental environmental insults has been recognized for a long time. However, extensive studies of the mechanisms involved had not been undertaken until recent years. Advances in molecular biology provide powerful tools and make such studies possible. We are gathering information about cellular events, signaling pathways, and molecular mechanisms of myocardial toxicologic responses to environmental toxicants and pollutants. Severe acute toxic insults cause cardiac cell death instantly. In the early response to mild environmental stimuli, biochemical changes such as alterations in calcium homeostasis occur. These may lead to cardiac arrhythmia, which most often is reversible. Prolonged stimuli activate transcription factors such as activator protein-1 through elevation of intracellular calcium and the subsequent activation of calcineurin. Upregulation by activated transcription factors of hypertrophic genes results in heart hypertrophy, which is a short-term adaptive response to detrimental factors. However, further development of hypertrophy will lead to severe and irreversible cardiomyopathy, and eventually heart failure. From cardiac hypertrophy to heart failure, myocardial cells undergo extensive biochemical and molecular changes. Cardiac hypertrophy causes tissue hypoperfusion, which activates compensatory mechanisms such as production of angiotensin II and norepinephrine. Both further stimulate cardiac hypertrophy and, importantly, activate counterregulatory mechanisms including overexpression of atrial natriuretic peptide and b-type natriuretic peptide, and production of cytokines such as tumor necrosis factor-alpha. This counterregulation leads to myocardial remodeling as well as cell death through apoptosis and necrosis. Cell death through activation of mitochondrial factors and other pathways constitutes an important cellular mechanism of heart failure. Our current knowledge of cardiotoxicity is limited. Further extensive studies are warranted for a comprehensive understanding of this field.

Metallothionein inhibits peroxynitrite-induced DNA and lipoprotein damage

Previous studies have demonstrated that metallothionein functions as an antioxidant that protects against oxidative DNA, protein, and lipid damage induced by superoxide anion, hydrogen peroxide, hydroxyl radical, and nitric oxide. The present study was undertaken to test the hypothesis that metallothionein also protects from DNA and lipoprotein damage induced by peroxynitrite, an important reactive nitrogen species that causes a diversity of pathological processes. A cell-free system was used. DNA damage was detected by the mobility of plasmid DNA in electrophoresis. Oxidation of low density lipoprotein was measured by a thiobarbituric acid-reactive substance, which was confirmed by lipid hydroperoxide assay. Plasmid DNA damage and low density lipoprotein oxidation were induced by 3-morpholinosydnomine, which produces peroxynitrite through the reaction between nitric oxide and superoxide anion or by synthesized peroxynitrite directly. DNA damage by 3-morpholinosydnomine was prevented by both metallothionein and superoxide dismutase, whereas the damage caused by peroxynitrite was prevented by metallothionein only. The oxidation of low density lipoprotein by 3-morpholinosydnomine and peroxynitrite was also significantly inhibited by metallothionein. This study thus demonstrates that metallothionein may react directly with peroxynitrite to prevent DNA and lipoprotein damage induced by this pathological reactive nitrogen species.

Generation and characterization of a novel tetravalent bispecific antibody that binds to hepatitis B virus surface antigens

Hepatitis B virus (HBV) infection is a worldwide public health problem affecting about 350 million people. HBV envelope contains three surface antigens, called pre-S1, pre-S2 and S. For the prophylaxis of HBV infection, only an anti-S monoclonal antibody was tested for the protective efficacy against HBV infection, but it was shown to be incomplete. In addition, some immune escape mutants carrying mutations on the S antigen were reported. Therefore, a multivalent bispecific antibody rather than a single monoclonal antibody would be more beneficial for the prophylaxis of HBV infection. We have generated a novel tetravalent bispecific antibody with two binding sites for each of the S and pre-S2 antigens. Each of the antigen-binding sites was composed of a single-chain Fv (ScFv). The tetravalent antibody was generated by constructing a single gene encoding a single-chain protein. This protein consisted of an anti-S ScFv whose carboxyl end was tethered, through a 45 amino acid linker, to the amino terminus of anti-preS2 ScFv that in turn was joined to the hinge region of human gamma1 constant region. The single-chain protein was expressed in Chinese hamster ovary cells and secreted in culture supernatant as a homodimeric molecule. The tetravalent bispecific antibody showed both anti-S and anti-pre-S2 binding activities. In addition, the binding affinity of the bispecific antiboy for HBV particles was greater than that of either parental antibody. The tetravalent bispecific antibody is a potentially useful reagent for the prevention and treatment of HBV infection.

A humanized anti--4-1BB monoclonal antibody suppresses antigen-induced humoral immune response in nonhuman primates

The interaction of 4-1BB and its ligand plays an important role in the regulation of T-cell-mediated immune responses. In this study, the authors examined the effect of a humanized anti--4-1BB monoclonal antibody (H4B4) on ovalbumin-induced immune responses in baboons. Previously, a mouse monoclonal antibody, 4B4 against the human 4-1BB molecule, was generated and characterized. Based on this antibody, a humanized version of 4B4 monoclonal antibody was constructed and the resultant antibody, H4B4, showed full recovery of the binding activity of the original antibody 4B4: a 1.5-fold increase in affinity for 4-1BB. In addition, H4B4 mediated antibody-dependent cellular cytotoxicity of activated human peripheral blood T cells and CEM cells in a dose-dependent manner. Weekly administration of H4B4 at doses of 1 or 4 mg/kg could suppress immunoglobulin G production against ovalbumin. This was not a result of the overall immune suppression, because the numbers of B and T cells and the total immunoglobulin G production were not altered during treatment with H4B4. These findings suggest that treatment with H4B4 may be a valid therapeutic approach to control unwanted immune responses in persons with autoimmune diseases.

Suppression by metallothionein of doxorubicin-induced cardiomyocyte apoptosis through inhibition of p38 mitogen-activated protein kinases

Cardiomyopathy induced by doxorubicin (DOX) has long been a major impediment of clinical applications of this effective anticancer agent. Previous studies have shown that cardiac-specific metallothionein (MT)-overexpressing transgenic mice are highly resistant to DOX-induced cardiotoxicity. To investigate cellular and molecular mechanisms by which MT participates in this cytoprotection, transgenic mice containing high levels of cardiac MT and non-transgenic controls were treated intraperitoneally with DOX at a single dose of 15 mg/kg and sacrificed on the 4th day after treatment. Myocardial apoptosis was detected by a terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay and confirmed by electron microscopy of immunogold staining of apoptotic nuclei. Dual staining of cardiac alpha-sarcomeric actin using an immunohistochemical method further identified apoptotic myocytes. Apoptosis was significantly inhibited in the transgenic myocardium. The anti-apoptotic effect of MT was further revealed in primary cultures of neonatal mouse cardiomyocytes. Furthermore, DOX activated p38 mitogen-activated protein kinase (MAPK), which was critically involved in the apoptotic process, as demonstrated by inhibition of DOX-induced apoptosis by a p38-specific inhibitor, SB203580. Both DOX-induced p38 MAPK activation and apoptosis were dramatically inhibited in the transgenic cardiomyocytes. The results thus demonstrate that DOX induces apoptosis in cardiomyocytes both in vivo and in vitro and MT suppresses this effect through at least in part inhibition of p38 MAPK activation.

Metallothionein inhibits myocardial apoptosis in copper-deficient mice: role of atrial natriuretic peptide

Dietary copper restriction causes heart hypertrophy in animal models. Several studies have indicated that this cardiomyopathy is mediated by oxidative stress. Metallothionein (MT), a low molecular weight and cysteine-rich protein, functions in protecting the heart from oxidative injury. We therefore used a cardiac-specific MT-overexpressing transgenic mouse model to test the hypothesis that MT inhibits copper deficiency-induced heart hypertrophy. Dams of both transgenic pups and non-transgenic littermates were fed a copper-adequate or copper-deficient diet, starting on the fourth day post-delivery, and the weanling mice were continued on the dams' diets until they were killed. Heart hypertrophy developed in copper-deficient pups by the fourth week of the combined pre- and post-weaning feeding and aggressively progressed until the end of the experiment (6 weeks). MT overexpression did not prevent the occurrence of heart hypertrophy, but inhibited the progression of this cardiomyopathy, which correlated with its suppression of cardiac lipid peroxidation. Corresponding to the progression of heart hypertrophy, myocardial apoptosis and atrial natriuretic peptide (ANP) production in the left ventricle were detected in non-transgenic copper-deficient mice; these effects were significantly suppressed in transgenic copper-deficient mice. Measurement of apoptosis by TUNEL assay and Annexin V-FITC confocal microscopy in primary cultures of cardiomyocytes revealed that ANP was largely responsible for the myocyte apoptosis and that MT inhibited ANP-induced apoptosis. The data clearly demonstrate that elevation of MT in the heart inhibits oxidative injury and suppresses the progression of heart hypertrophy in copper deficiency, although it does not block its initiation. The results suggest that MT inhibits the transition from heart hypertrophy to failure by suppressing apoptosis through inhibition of both cardiac ANP production and its apoptotic effect.

Immunocytochemical localization of metallothionein and its relation to doxorubicin toxicity in transgenic mouse heart

Previous studies using a cardiac-specific metallothionein-overexpressing transgenic mouse model have demonstrated that metallothionein protects the heart from doxorubicin toxicity. The present study was undertaken to determine cellular and subcellular distribution of metallothionein and located the antioxidant action of this protein in the transgenic heart. Using light microscopic immunoperoxidase method, it was identified that the overexpressed metallothionein is localized exclusively in cardiomyocytes. The electron microscopic immunogold method revealed that elevated metallothionein is in nucleus, myofibers, and sarcoplasm. In contrast with these distributions, metallothionein in nontransgenic myocardium was undetectable by immunoperoxidase light microscopy and was seldom found in nucleus and myofibers by immunogold electron microscopy. Treatment with doxorubicin induced cytoplasmic vacuolization and severe damages in myofilaments and nucleus in nontransgenic myocardium. The most prominent injury, however, occurred in mitochondria, including striking size and shape changes, focal swelling and loss of cristae. These damages were rarely found in the doxorubicin-treated transgenic myocardium. In particular, the internal morphology of mitochondria was maintained essentially normal, although metallothionein was not localized in this compartment in transgenic hearts. This study thus demonstrates that although the subcellularly localized action of metallothionein is important, it also plays a significant role in protection against oxidative injury by doxorubicin in remote organelles.

Cellular and subcellular localization of catalase in the heart of transgenic mice

Previous studies have described a cardiac-specific, catalase-overexpressing transgenic mouse model that was used to study myocardial oxidative injury. This study was undertaken to demonstrate cellular and subcellular localization of catalase in the hearts of transgenic mice. By the light microscopic immunoperoxidase method, we found that the overexpressed catalase was exclusively localized in cardiomyocytes. The ratios of immunoreactive cardiomyocytes in the heart were quite different among three transgenic lines examined but agreed with the elevated levels of catalase activity. In the cardiac blood vessels, positive cells were found in the walls of pulmonary veins and the vena cava, which consist of cardiomyocytes, but not in the pulmonary arteries, aorta, or cardiac valves. The electron microscopic immunogold method revealed that the elevated catalase was in sarcoplasm, nucleus, and peroxisomes, but not in mitochondria. In contrast to these distributions, catalase in the non-transgenic cardiomyocytes was in peroxisomes only. In addition, the number and size of peroxisomes in the transgenic cardiomyocytes were markedly increased, but no other ultrastructural changes were observed in comparison with those of non-transgenic mice. These results demonstrated that the elevated catalase in transgenic mouse heart is localized in cardiomyocytes and is distributed to peroxisomal and extraperoxisomal, but not mitochondrial, compartments.

Mouse monoclonal antibodies to hepatitis B virus preS1 produced after immunization with recombinant preS1 peptide

We have efficiently generated mouse monoclonal antibodies (MAbs), which bind specifically to amino acids 21-47 of the preS1 domain of hepatitis B virus (HBV) by immunizing mice with the preS1 peptide (amino acids, aa 1-56) conjugated to keyhole limpet hemocyanin. Hybridomas were screened by an indirect enzyme-linked immunosorbent assay (ELISA) using the purified preS1 peptide as a coated antigen. Eighteen positive hybridomas were selected and subjected to isotyping. Of these, 5 clones secreted immunoglobulin G (IgG) and 13 clones secreted IgM. Four (KR1, KR2, KR3, and KR4) of the 5 IgG MAbs bound to preS1 peptide (aa 21-47). Epitope mapping using bacterially expressed GST fusion proteins revealed that three clones (KR2, KR3, KR4) (IgG1, K) recognize aa 21-35, while KR1 (IgG2a, K) recognizes aa 35-47 of the preS1. These MAbs immunoprecipitated HBV particles, demonstrating that they bind to native HBV particles.

Erythropoietin does not affect nitric oxide system in rats with chronic renal failure

We investigated to see whether an altered role of nitric oxide (NO) system is involved in erythropoietin (EPO)-induced hypertension in chronic renal failure (CRF). Male Sprague-Dawley rats were five-sixths nephrectomized to induce CRF. Six weeks after the operation, EPO or vehicle was injected for another 6 weeks. Plasma and urine nitrite/nitrate (NOx) levels were determined. Expression of NO synthase (NOS) proteins in the aortae and kidneys were also determined. In addition, the isometric tension of isolated aorta in response to acetylcholine and nitroprusside was examined. Blood pressure progressively rose in CRF groups, the degree of which was augmented by EPO treatment. Plasma NOx levels did not differ among the groups, while urine NOx levels were lower in CRF groups. Endothelial NOS expression was lower in the kidney and aorta in CRF rats, which was not further affected by EPO-treatment. The inducible NOS expression in the kidney and aorta was not different among the groups. Acetylcholine and sodium nitroprusside caused dose-dependent relaxations of aortic rings, the degree of which was not altered by EPO-treatment. Taken together, EPO-treatment aggravates hypertension in CRF, but altered role of NO system may not be involved.

Alterations in hypertrophic gene expression by dietary copper restriction in mouse heart

Dietary copper (Cu) restriction causes a hypertrophic cardiomyopathy similar to that induced by work overload in rodent models. However, a possible change in the program of hypertrophic gene expression has not been studied in the Cu-deficient heart. This study was undertaken to fill that gap. Dams of mouse pups were fed a Cu-deficient diet (0.35 mg/kg diet) or a Cu-adequate control diet (6.10 mg/kg) on the fourth day after birth, and weanling mice continued on the dams' diet until they were sacrificed. After 5 weeks of feeding, Cu concentrations were dramatically decreased in the heart and the liver of the mice fed the Cu-deficient diet. Corresponding to these changes, serum ceruloplasmin concentrations and hepatic Cu,Zn-superoxide dismutase activities were significantly (P<0.05) depressed. The size of the Cu-deficient hearts was greatly enlarged as estimated from the absolute heart weight and the ratio of heart weight to body weight. The abundances of mRNAs for atrial natriuretic factor, beta-myosin heavy chain, and alpha-skeletal actin in left ventricles were all significantly increased in the Cu- deficient hearts. Furthermore, Cu deficiency activated the expression of the c-myc oncogene in the left ventricle. This study thus demonstrated that a molecular program of alterations in embryonic genes, similar to that shown in the work-overloaded heart, was activated in the hypertrophied heart induced by Cu deficiency.

The antioxidant function of metallothionein in the heart

The antioxidant function of metallothionein (MT) was first suggested in the early 1980s. Studies in vitro have revealed that MT reacts directly with reactive oxygen species, including superoxide and hydroxyl radicals and hydrogen peroxide. These reactions have never been demonstrated in intact animal studies. Nevertheless, both pharmacologic and genetic studies have shown that MT functions in protection against oxidative injury in vivo. In particular, the antioxidant function of MT in the heart has been explored extensively. The data gathered from recent studies using a cardiac-specific, MT-overexpressing transgenic mouse model have provided direct evidence to support this physiological role of MT. Under acute and chronic oxidative stress conditions such as treatment with doxorubicin, ischemia-reperfusion, and dietary copper restriction, MT-overexpressing transgenic mouse hearts displayed a marked resistance to the injurious consequences, including biochemical, pathological, and functional alterations. This protective action of MT correlates with its inhibition of reactive oxygen species-induced lipid peroxidation. A critical elucidation of the mechanism of action of MT as an antioxidant in vivo remains to be achieved. However, the combination of recent understanding of the zinc cluster structure of MT and novel molecular genetic approaches has provided the basis for further advancement in this field.

Inhibition of activation of nuclear factor kappaB is responsible for inhibition of inducible nitric oxide synthase expression by higenamine, an active component of aconite root

Effects of higenamine on nitric oxide (NO) production and inducible NO synthase (iNOS) mRNA expression (RAW 264.7 cells), on vascular reactivity in vitro and in vivo (rats), and on survival rates (mice) and serum nitrite/nitrate levels (rats) were investigated by using last lipopolysaccharide (LPS) plus interferon (IFN)-gamma. Higenamine concentration-dependently inhibited NO production and inducible NO synthase mRNA in RAW 264.7 cells, in which the IC(50) was 53 microM. Higenamine (10 mg/kg i.p.) administered 90 min before LPS (5 mg/kg i.v.) prevented not only LPS-induced hypotension but also pressor response to norepinephrine (1 microgram/kg) in rats. Incubation of thoracic aorta with LPS (300 ng/ml) for 8 h in vitro resulted in suppression of the vasoconstrictor effects to phenylephrine, which was prevented by coincubation with higenamine. The survival rate to endotoxin in mice was significantly (P <.01) increased by the presence of higenamine in the LPS-treated group up to 48 h. Serum nitrite/nitrate levels were significantly (P <.05) reduced by higenamine in LPS-treated rats. Finally, higenamine inhibited the activation of nuclear factor kappaB in RAW 264.7 cells due to LPS + IFN-gamma by mobility shift assays. Taken together, these data strongly suggest that higenamine inhibits iNOS expression by inhibiting nuclear factor kappaB activation by LPS + IFN-gamma, which may be beneficial in inflammatory diseases in which enhanced formation of NO is the main causative factor. Furthermore, due to positive inotropic action, higenamine may be more effective in a condition where myocardial contractility is likely to depress, such as in septic shock and/or endotoxin-induced inflammatory disorders.

An axisymmetric poroelastic finite element formulation

In the past, various two- and three-dimensional Cartesian, poroelastic finite element formulations have been proposed and demonstrated. Here an axisymmetric formulation of a poroelastic finite element is presented. The intention of this work was to develop a finite element formulation that could easily and efficiently model axisymmetric sound propagation in circular structures having arbitrary, axially dependent radii, and that are lined or filled with elastic porous sound absorbing materials such as foams. The formulation starts from the Biot equations for an elastic porous material expressed explicitly in axisymmetric form. By following a standard finite element development, a u-U formulation results. Procedures for coupling the axisymmetric elements to an adjacent acoustical domain are described, as are the boundary conditions appropriate for unfaced foams. Calculations described here show that the present formulation yields predictions as accurate as a Cartesian, three-dimensional model in much reduced time. Predictions made using the present model are also compared with measurements of sound transmission through cylindrical foam plugs, and the predicted results are shown to agree well with the measurements. Good agreement was also found in the case of sound transmission through a conical foam plug.

Generation and chromosome mapping of expressed sequence tags (ESTs) from a human infant thymus

In an effort to identify novel genes that are expressed differentially in an infant thymus, we constructed an oligo-d(T) primed cDNA library from a human infant thymus followed by single-run partial sequencing to generate expressed sequence tags (ESTs). Characterization of more than 1400 sequences enabled us to convert human thymus transcripts into 1223 useful ESTs. These ESTs consisted of 613 (50.1%) showing homology to known human genes, 51 (4.2%) matching to genes from other species, 289 (23.6%) matching ESTs of unknown functions, and 182 (14.9%) being novel transcripts. The expression profile of an infant thymus features a high number of genes related to cell division-DNA synthesis and gene-protein expression, indicating the active growth stage of an infant thymus. To identify the chromosomal localization of 43 thymus ESTs, PCR-based mapping was performed using a human-rodent somatic cell hybrid or radiation hybrid mapping panel. The results indicated that several novel genes were determined to be located in the vicinity of previously mapped disease loci; histidinemia loci, plasminogen Tochigi disease loci, Ehlers-Danlos syndrome, hypertriglyceridemia, thyroid resistance locus, ocular albinism, galactosemia, porphyria variegata, Charcot-Marie-tooth disease, FEOM (fibrosis of extraocular muscles), Prader-Willi syndrome.

Inhibition of doxorubicin toxicity in cultured neonatal mouse cardiomyocytes with elevated metallothionein levels

Controversial results have been reported regarding whether metallothionein (MT) functions in doxorubicin (DOX) detoxification in the heart. To determine unequivocally the role of MT in cardiac protection against the toxicity of DOX, ventricular cardiomyocytes isolated from 1- to 3-day neonatal transgenic mice with high levels of cardiac MT and from nontransgenic control animals were applied. On the 6th day of culturing, MT concentrations in the transgenic cardiomyocytes were about 2-fold higher than those in the nontransgenic cells. DOX was added directly into the cultures. Compared with nontransgenic controls, transgenic cardiomyocytes displayed a significant (p <.05) resistance to DOX cytotoxicity, as measured by morphological alterations, cell viability, and lactate dehydrogenase leakage from the cells. This cytoprotective effect of MT correlated with its inhibition of DOX-induced lipid peroxidation. These observations demonstrate unequivocally that elevation of MT concentrations in the cardiomyocytes of 2-fold higher than normal provides efficient protection against DOX toxicity.

Metallothionein inhibits ischemia-reperfusion injury in mouse heart

Oxidative stress is believed to play a major role in ischemia-reperfusion injury to the heart. Metallothionein (MT), a potential free radical scavenger, may function in cardiac protection against ischemia-reperfusion damage. To test this hypothesis, a specific cardiac MT-overexpressing transgenic mouse model was used. The hearts isolated from these animals were subjected to 50 min of warm (37 degrees C) zero-flow ischemia followed by 60- or 90-min reflow. Compared with the nontransgenic controls, the transgenic mouse hearts with MT concentrations approximately 10-fold higher than normal showed significantly improved recovery of contractile force postischemia (69.2 +/- 4.2 vs. 26.0 +/- 6.0% at the end of 60-min reperfusion, P < 0.01). Efflux of creatine kinase from these transgenic hearts was reduced by more than 50% (P < 0.01). In addition, the zone of infarction induced by ischemia-reperfusion at the end of 90-min reperfusion was suppressed by approximately 40% (P < 0.01) in the transgenic hearts. The results strongly indicate that MT provides protection against ischemia-reperfusion-induced heart injury.

Traumatic hemipelvectomy before body image has developed

Traumatic hemipelvectomy is rarely observed because very few patients have survived from the initial trauma. We describe one male child who survived from this massive trauma with a good functional outcome. The boy was 28 months old when he was accidentally struck by a truck. He had severe open trauma of the pelvis and hemorrhage of the left lower limb. Amputation of the left hemipelvis, colostomy, cystostomy and removal of the left avulsed testicle were performed. Once healing had been achieved, he was transferred to our Department of Physical Medicine and Rehabilitation and rehabilitative management was begun, including prosthetic measurement and psychologic intervention for the patient and his parents. For 13 years of long-term follow-up, his prosthesis was readjusted annually. Now he is a 16-year-old middle school student. He is functioning remarkably well with a prosthesis. The psychologic report shows that he is emotionally stable and has good scholastic performance. Although hemipelvectomy appears to be a radical procedure in children, the potential for rehabilitation in a group of children before body image has developed appears to be unexpectedly good.

Inhibition of lipopolysaccharide-induced inducible nitric oxide (iNOS) mRNA expression and nitric oxide production by higenamine in murine peritoneal macrophages

Nitric oxide synthesized by inducible nitric oxide synthase (iNOS) has been implicated as a mediator of inflammation in rheumatic and autoimmune diseases. The effects of higenamine, a tetrahydroisoquinoline compound, on induction of NOS by bacterial lipopolysaccharide (LPS) were examined in murine peritoneal macrophages. LPS-induced nitrite/nitrate production was markedly inhibited by higenamine which at 0.01 mM, decreased nitrite/nitrate levels by 48.7+/-4.4%. This was comparable to the inhibition of LPS-induced nitrite/nitrate production by tetrandrin (49.51+/-2.02%) at the same concentration. Northern and Western blot analysis of iNOS expression demonstrated that iNOS expression was significantly attenuated following co-incubation of peritoneal macrophages with LPS (10 microg/ml; 18 hrs) and higenamine (0.001, 0.01 mM; 18 hrs). These results suggest that higenamine can inhibit LPS-induced expression of iNOS mRNA in murine peritoneal macrophages. The clinical implications of these findings remain to be established.

Role of nitric oxide in the pathogenesis of diabetic nephropathy in streptozotocin-induced diabetic rats

OBJECTIVES

Several reports suggest that enhanced generation or actions of nitric oxide (NO) have been implicated in the pathogenesis of glomerular hyperfiltration and hyperperfusion that occurs in early diabetes. However, the precise role of altered NO generation in the pathogenesis of diabetic nephropathy is unclear. The present study was aimed at investigating the role of nitric oxide in the pathogenesis of glomerular hyperfiltration and hyperperfusion in streptozotocin-induced diabetic rats.

METHODS

To evaluate the role of NO in diabetic hyperfiltration, we measured plasma and urine concentrations of NO2-/NO3-, stable metabolic products of NO and protein expressions of three isoforms of nitric oxide synthase (NOS) in streptozotocin-induced diabetic rats. We also investigated renal hemodynamic changes, such as glomerular filtration rate (GFR) and renal plasma flow (RPF), in responses to acute and chronic administration of NO synthesis inhibitor, nitro-L-arginine methyl ester (L-NAME), in diabetic and control rats.

RESULTS

Diabetic rats exhibited significantly elevated plasma and urinary NO2-/NO3- levels at 28 days after streptozotocin injection, and total excretion of NO2-/NO3- was approximately five-fold higher in diabetic rats than controls. Insulin and L-NAME treatment prevented the increases in plasma and urinary NO2-/NO3- concentrations in diabetic rats, respectively. The three isoforms of NOS (bNOS, iNOS, and ecNOS) were all increased in the renal cortex, whereas they remained unaltered in the renal medulla at day 28. GFR and RPF were significantly elevated in diabetic rats, and acute and chronic inhibition of NO synthesis by L-NAME attenuated the renal hemodynamic changes (increases in GFR and RPF) in diabetic rats, respectively.

CONCLUSIONS

NO synthesis was increased due to enhanced NOS expression in diabetic rats, and chronic NO blockade attenuated renal hyperfiltration and hyperperfusion in diabetic rats. In addition, diabetic rats exhibited enhanced renal hemodynamic responses to acute NO inhibition and excreted increased urinary NO2-/NO3-. These results suggest that excessive NO production may contribute to renal hyperfiltration and hyperperfusion in early diabetes.

Altered renal expression of nitric oxide synthase isozymes in spontaneously hypertensive rats

OBJECTIVES

The present study was aimed at exploring whether the pathogenesis of hypertension is related with an altered expression of nitric oxide synthase (NOS) isozymes, i.e., bNOS, iNOS and ecNOS.

METHOD

By Western blot analysis, the expression of NOS isozymes were determined in the kidney isolated from spontaneously hypertensive rats (SHR) and their normotensive control, Wistar-Kyoto rats (WKY). The NOx (nitrite/nitrate) contents were also determined in the kidney and plasma.

RESULTS

The plasma NOx was significantly increased in SHR compared with that in WKY. The basal level of NOx was higher in the medulla and cortex of the kidney in SHR compared with that in WKY rat. bNOS proteins were expressed higher in the outer medulla and cortex, and iNOS proteins were higher in the inner medulla, outer medulla and cortex in SHR. ecNOS expression did not significantly differ between the SHR and WKY.

CONCLUSIONS

These results indicate that the NO generation may not be impaired, but rather increased. It is likely that the increased expression of NOS isozymes is a counter-reactive phenomenon secondary to the increased blood pressure in this model of hypertension.

Metallothionein-overexpressing neonatal mouse cardiomyocytes are resistant to H2O2 toxicity

To study cellular and molecular events of cardiac protection by metallothionein (MT) from oxidative injury, a primary neonatal cardiomyocyte culture was established from a specific cardiac MT-overexpressing transgenic mouse model. Ventricular cardiomyocytes were isolated from 1- to 3-day-old neonatal mice and cultured in an Eagle's minimum essential medium supplemented with 20% fetal bovine serum under an atmosphere of 5% CO2-95% air at 37 degreesC. Forty-eight hours after plating was completed, the purity of such cultures was 95% myocytes, assessed by an immunocytochemical assay. Over 80% of the cardiomyocytes beat spontaneously on the first day of culture and synchronously in a confluent monolayer after the sixth day of culture. Cellular MT concentrations in the transgenic cardiomyocytes before culturing and on the sixth day postculturing were about seven- and twofold higher than nontransgenic controls, respectively. However, there were no significant differences in cell morphology, glutathione content, and antioxidant enzymatic activities between these two types of cardiomyocytes. When these cells were challenged by H2O2, the transgenic cardiomyocytes displayed a significant resistance to the toxic effect of this oxidant, as measured by cell viability, lactate dehydrogenase leakage, and morphological alterations. In addition, the transgenic cells were highly protected from H2O2-induced lipid peroxidation. These observations demonstrate that MT protects the cultured cardiomyocytes from H2O2 toxicity by preventing its interaction with macromolecules such as lipids, and this cultured primary neonatal mouse cardiomyocyte system provides a valuable tool to directly study cellular and molecular events of MT in cardiac protection against oxidative injury.

Surface ultrastructure of Metagonimus miyatai metacercariae and adults

A scanning electron microscopic study was performed to observe surface ultrastructures of excysted metacercariae and adults of Metagonimus miyatai. Metacercariae were collected from the scale of the pale chub (Zacco platypus), and adult flukes were harvested 1-4 weeks after infection to rats. In excysted metacercariae, the oral sucker was devoid of tegumental spines and had type I and type II sensory papillae. Anteriorly to the ventral sucker, spines were dense and digitated into 5-7 points, whereas near the posterior end of the body spines were sparse and digitated into 2-3 points. In one-week adults, 7 type II sensory papillae were arranged around the lip of the oral sucker, and at inner side of the lip one pair of small and two pairs of large type 1 sensory papillae were seen on each side. The distribution of tegumental spines was similar to that of metacercariae, but they were more differentiated with 9-11 pointed tips. In two- to four-week old adults, the surface ultrastructure was nearly the same as in one-week old adults, however, sperms were frequently seen entering into the Laurer's canal. Conclusively, the surface ultrastructure of M. miyatai was generally similar to that of M. yokogawai, however, differentiation of tegumental spines and distribution of sensory papillae around the oral sucker were different between the two species, which may be of taxonomic significance.

Inhibition of buthionine sulfoximine-enhanced doxorubicin toxicity in metallothionein overexpressing transgenic mouse heart

Cardiotoxicity and acquired drug resistance of tumor cells have been two impediments for the clinical use of doxorubicin (DOX). Trials are ongoing using buthionine sulfoximine (BSO) to deplete glutathione (GSH) content in tumors, whose elevation was found to contribute to the acquired drug resistance. However, BSO also decreases GSH content in the heart, enhancing DOX cardiotoxicity. Recent studies have shown that metallothionein (MT) is an important factor in cardiac protection against DOX. Our study was undertaken to determine whether MT can compensate for the loss of protection from GSH depletion in the heart. Transgenic mice with cardiac MT concentrations about 20-fold higher than normal, and nontransgenic controls were treated with BSO by i.p. injection at 5 mmol/kg, two times with a 12-hr interval, before treatment with DOX at a single dose of 15 mg/kg, lasting for 4 days. Cardiac GSH was depleted by 60% in both transgenic and non-transgenic mice. DOXinduced cardiotoxicity, as measured by blood levels of creatine kinase and malondialdehyde concentrations in the heart, was dramatically increased in the BSO-treated nontransgenic mice. This increase was completely inhibited in the BSO-treated transgenic mice. These results demonstrate that cardiac MT overexpressing transgenic mice are resistant to BSO-enhanced DOX cardiotoxicity. Selective modulations of decreasing DOX resistance in tumors by BSO and of increasing cardioprotection by MT induction may provide an alternative approach to improved DOX chemotherapeutic efficacy.