Determinants of exercise-induced pulmonary hypertension in rheumatic mitral stenosis: a study with exercise stress and speckle tracking echocardiography

Backgrounds

Exercise stress echocardiography is helpful in assessing hemodynamic consequence of mitral stenosis (MS) and in guiding treatment. Exercised-induced pulmonary hypertension (PH) is result of severity of MS, but myocardial function of left ventricle and clinical factors can also have effect.

Purpose

We aimed to evaluate the associated factors with the pulmonary artery systolic pressure (PASP) in exercise stress echocardiography through 2D, Doppler, and speckle tracking imaging in patients with rheumatic MS.

Methods

A total of 164 patients with rheumatic MS underwent a graded, symptom-limited, supine bicycle exercise with echocardiography. After exclusion of patients who had very severe MS (valve area <1.0 cm2), a history of surgery or recent percutaneous mitral valvotomy, combined significant aortic valve dysfunction, left ventricular (LV) ejection fraction <50%, we analyzed 113 patients (77.6% female; mean age, 56±9 years). Echocardiographic parameters at rest, each stage (25 watt increment every 3 minutes), and peak exercise were obtained. Exercised induced PH was defined as present if PASP >60 mmHg at peak exercise. LV global longitudinal strain (LV-GLS) and left atrial (LA) strain were analyzed by software. The subjects were divided into 4 groups according to mean transmitral pressure gradient (MG) (15 mmHg) and PASP (60 mmHg) at peak exercise (Group 1, MG <15 mmHg and PASP <60 mmHg, n=29; Group 2, MG <15 mmHg and PASP ≥60 mmHg, n=9; Group 3, MG ≥15 mmHg and PASP <60 mmHg, n=23; Group 4, MG ≥15 mmHg and PASP ≥6 0mmHg, n=52).

Results

The mean mitral valve area was 1.30±0.23 cm2. PASP increased from 30.0±8.0 mmHg at rest to 61.0±14.8 mmHg at peak exercise, along with increase MG. 61 (53.9%) subjects had PASP>60 mmHg at peak exercise. Compared to group 1, group 2 had higher incidence of diabetes mellitus (DM) and significantly elevated PASP at baseline and impaired LV-GLS. However, there was no statical difference in LA strain between the two groups. In subjects with MG above 15 mmHg (Group 3 and 4), a similar trend was observed in occurrence of exercise-induced PH. On logistic multivariate regression, exercised induced PH was independently associated with female (HR: 5.35, 95% CI: 1.51–24.95; p=0.032), DM (HR: 10.05, 95% CI, 1.35–74.45; p=0.024), MG at peak exercise (HR: 1.17, 95% CI, 1.02–1.34; p=0.002), PASP at rest (HR: 1.17, 95% CI, 1.05–1.30; p=0.002), and LV-GLS (HR: 1.45, 95% CI, 1.09–1.91; p=0.009), but not with LA strain. The predictive value for exercised induced PH was highest when adding LV-GLS to the clinical factor (age, sex, DM) and echocardiographic parameters (Figure 1).

Conclusions

Exercised induced PH is affected by not only hemodynamic consequence of MS, but also myocardial function of left ventricle and clinical factors. Therefore, when determining the optimal timing of intervention based on exercise-induced PH in rheumatic MS patients, LV-GLS should be evaluated comprehensively along with MS characteristics.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Yonsei University College of Medicine

Time series analysis of delta neutrophil index as the predictor of sepsis in patients with acute poisoning

Delta neutrophil index (DNI), which reflects the fraction of immature granulocytes, is used to detect infection and sepsis from noninfectious conditions, but few studies have evaluated in the early stage of acute poisoning. This retrospective observational study was performed on acute poisoning patients who visited to the emergency department (ED) and were consecutively admitted in intensive care units over 18-month period. The serial DNI, conventional inflammatory biomarkers, and culture results were obtained in the ED and after admission. The outcomes were the identification of sepsis, bacteremia, and 30-day mortality. Of 166 patients (mean age, 56.0 years) in this cohort, 59 (35.5%) had sepsis and 29 (17.5%) had bacteremia. Initial and peak DNI fractions 24 h after ED admission were strong independent predictors of sepsis development. Analysis of the area under the curve according to multiple receiver operating characteristics showed that DNI had a higher capability to predict sepsis than other parameters (0.815 for DNI, 0.700 for procalcitonin, 0.681 for C-reactive protein, and 0.741 for white blood cell). Using multivariable logistic regression analysis, it was found that DNI was an independent predictor of sepsis (95% confidence interval (CI) of odds: 1.03-1.18) and bacteremia (95% CI: 1.01-1.14). Therefore, initial and serial measurement of DNI may serve as useful risk predictor for development of sepsis or bacteremia in acute poisoning.

Elevation of p11 in lateral habenula mediates depression-like behavior

The lateral habenula (LHb) is a key brain region involved in the pathophysiology of depression. It is activated by stimuli associated with negative experiences and is involved in encoding aversive signals. Hyperactivity of LHb is found in both rodent models of depression and human patients with depression. However, little is known about the underlying molecular mechanisms. Here we show that in LHb neurons, p11, a multifunctional protein implicated in depression, is significantly upregulated by chronic restraint stress. Knockdown of p11 expression in LHb alleviates the stress-induced depression-like behaviors. Moreover, chronic restraint stress induces bursting action potentials in LHb neurons, which are abolished by p11 knockdown. Overexpression of p11 in dopamine D2 receptor-containing LHb neurons of control mice induces depression-like behaviors. These results have identified p11 in LHb as a key molecular determinant regulating negative emotions, which may help to understand the molecular and cellular basis of depression.

Cellular and molecular basis for stress-induced depression

Chronic stress has a crucial role in the development of psychiatric diseases, such as anxiety and depression. Dysfunction of the medial prefrontal cortex (mPFC) has been linked to the cognitive and emotional deficits induced by stress. However, little is known about the molecular and cellular determinants in mPFC for stress-associated mental disorders. Here we show that chronic restraint stress induces the selective loss of p11 (also known as annexin II light chain, S100A10), a multifunctional protein binding to 5-HT receptors, in layer II/III neurons of the prelimbic cortex (PrL), as well as depression-like behaviors, both of which are reversed by selective serotonin reuptake inhibitors (SSRIs) and the tricyclic class of antidepressant (TCA) agents. In layer II/III of the PrL, p11 is highly concentrated in dopamine D2 receptor-expressing (D2⁺) glutamatergic neurons. Viral expression of p11 in D2⁺ PrL neurons alleviates the depression-like behaviors exhibited by genetically manipulated mice with D2⁺ neuron-specific or global deletion of p11. In stressed animals, overexpression of p11 in D2⁺ PrL neurons rescues depression-like behaviors by restoring glutamatergic transmission. Our results have identified p11 as a key molecule in a specific cell type that regulates stress-induced depression, which provides a framework for the development of new strategies to treat stress-associated mental illnesses.

Pharmacokinetics of amoxicillin trihydrate in cultured olive flounder (Paralichthys olivaceus)

The study was aimed at investigating the pharmacokinetics of amoxicillin trihydrate (AMOX) in olive flounder (Paralichthys olivaceus) following oral, intramuscular, and intravenous administration, using high-performance liquid chromatography following. The maximum plasma concentration (Cmax ), following oral administration of 40 and 80 mg/kg body weight (b.w.), AMOX was 1.14 (Tmax , 1.7 h) and 0.76 μg/mL (Tmax , 1.6 h), respectively. Intramuscular administration of 30 and 60 mg/kg of AMOX resulted in Cmax values of 4 and 4.3 μg/mL, respectively, with the corresponding Tmax values of 29 and 38 h. Intravenous administration of 6 mg/kg AMOX resulted in a Cmax of 9 μg/mL 2 h after administration. Following oral administration of 40 and 80 mg/kg AMOX, area under the curve (AUC) values were 52.257 and 41.219 μg/mL·h, respectively. Intramuscular 30 and 60 mg/kg doses resulted in AUC values of 370.274 and 453.655 μg/mL·h, respectively, while the AUC following intravenous administration was 86.274 μg/mL·h. AMOX bioavailability was calculated to be 9% and 3.6% following oral administration of 40 and 80 mg/kg, respectively, and the corresponding values following intramuscular administration were 86% and 53%. In conclusion, this study demonstrated high bioavailability of AMOX following oral administration in olive flounder.

Novel fusion transcripts in human gastric cancer revealed by transcriptome analysis

Gene fusion is involved in the development of various types of malignancies. Recent advances in sequencing technology have facilitated identification of gene fusions and have stimulated the research of this field in cancer. In the present study, we performed next-generation transcriptome sequencing in order to discover novel gene fusions in gastric cancer. A total of 282 fusion transcript candidates were detected from 12 gastric cancer cell lines by bioinformatic filtering. Among the candidates, we have validated 19 fusion transcripts, which are 7 inter-chromosomal and 12 intra-chromosomal fusions. A novel DUS4L-BCAP29 fusion transcript was found in 2 out of 12 cell lines and 10 out of 13 gastric cancer tissues. Knockdown of DUS4L-BCAP29 transcript using siRNA inhibited cell proliferation. Soft agar assay further confirmed that this novel fusion transcript has tumorigenic potential. We also identified that microRNA-coding gene PVT1, which is amplified in double minute chromosomes in SNU-16 cells, is recurrently involved in gene fusion. PVT1 produced six different fusion transcripts involving four different genes as fusion partners. Our findings provide better insight into transcriptional and genetic alterations of gastric cancer: namely, the tumorigenic effects of transcriptional read-through and a candidate region for genetic instability.

Effect of wrist position on the measurement of carpal indices on the lateral radiograph

The purpose of this study was to find out whether the carpal indices measured on lateral radiographs with a slightly malpositioned wrist are the same as those measured in the true neutral position. Lateral radiographic views of 25 wrists were taken with 5° intervals from 20° of flexion to 20° of extension. Most carpal indices measured in the flexed or extended position were significantly different from the wrist in zero flexion-extension, except scapholunate angle at 5° of extension and scaphocapitate angle at 5° and 10° of flexion. Starting from the flexed position, there was an average of -4.0° change in radioscaphoid angle, -1.0° in scapholunate angle, -1.0° in scaphocapitate angle, +3.0° in radiolunate angle, and +2.0° in lunocapitate angle for each 5° of extension with linear trends. The results from this study suggest that even minimal degrees of flexion-extension can affect the measurements of carpal indices on lateral radiographs.

Characteristics of responders and non-responders to risperidone monotherapy or placebo in co-occurring bipolar disorder and anxiety disorder

Clinical characteristics predicting response and remission to psychopharmacological treatment of bipolar disorder (BD) and co-occurring anxiety disorders have been understudied. We hypothesized that non-response to risperidone or placebo in individuals with co-occurring BD and anxiety symptoms would be associated with a more severe clinical course of BD, and certain demographic variables. This study was a secondary analysis of a randomized, double-blind, parallel, 8-week study comparing risperidone monotherapy and placebo in individuals with BD plus current panic disorder, current generalized anxiety disorder (GAD), or lifetime panic disorder (n=111) [31]. We compared clinical characteristics of responders (50% improvement on the Hamilton Anxiety Scale [HAM-A]) and non-responders as well as remitters (HAM-A<7) and non-remitters in risperidone treatment (n=54) and placebo (n=57) groups. For non-responders in the risperidone group, co-occurring lifetime panic disorder was significantly more common than for non-responders in the placebo group. Apart from this, no significant differences in course of illness or demographics were found either between or across groups for patients with BD and co-occurring anxiety symptoms receiving risperidone or placebo in this acute phase study.

Transthoracic fine-needle aspiration biopsy of the lungs using a C-arm cone-beam CT system: diagnostic accuracy and post-procedural complications

OBJECTIVE

The purpose of our study was to evaluate the diagnostic accuracy of transthoracic fine-needle aspiration biopsy (TFNAB) using a C-arm cone-beam CT (CBCT) system and to assess risk factors for immediate post-procedural complications in patients with lung lesions.

METHODS

From October 2007 to April 2009, 94 TFNAB procedures using a C-arm system were studied in 91 patients with pulmonary lesions a chest CT scans. We retrospectively reviewed the patients' radiological and histopathological findings. We evaluated the lesion size, lesion abutted to pleura and presence or absence of emphysema along the needle path, lesion depth, visibility of target lesion and patient's position. Pneumothorax and pulmonary haemorrhage were assessed after TFNAB. Overall diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were analysed.

RESULTS

In 94 TFNAB procedures, 58 lesions were malignant and 36 were benign. The sensitivity, specificity, PPV, NPV and overall diagnostic accuracy rate of TFNAB were 93.1%, 100%, 100%, 90% and 97.9%, respectively. Pneumothorax was developed in 24 procedures. None of the parameters showed significant impact on the frequency of the pneumothorax. Overall haemorrhage occurred in 43 procedures. The incidence of overall haemorrhage was higher in patients with smaller lesions, longer pleural distance and pleural abutted lesions (p<0.05). Differences in visibility at projection radiographs were statistically significant between patients with or without perilesional haemorrhage (p<0.05).

CONCLUSION

Transthoracic fine-needle aspiration biopsy using a C-arm CBCT system is feasible for imaging guidance of lung lesion and early detection of the procedural-related complications.

Determination of low (137)Cs concentration in seawater using ammonium 12-molybdophosphate adsorption and chemical separation method

A new method has been developed for analyzing (137)Cs in a small volume of seawater. Ammonium 12-molybdophosphate (AMP) was used two times during pretreatment procedure. The first step was to adsorb (137)Cs in seawater samples into AMP in order to reduce sample volume, and the second was to remove (87)Rb, interference nuclide for beta counting. The AMP adsorbing (137)Cs was dissolved by sodium hydroxide solution, and then (137)Cs was finally formed to be cesium chloroplatinate precipitate by adding 10% hexachloroplatinic acid. The beta rays emitted from (137)Cs were measured with a low background gas-proportional alpha/beta counter. This method was applied to several seawater samples taken in the East Sea of Korea. Compared to the routinely used gamma-spectrometry method, this new AMP method was reliable and suitable for analyzing (137)Cs in deep seawater.

Nationwide survey on the natural radionuclides in industrial raw minerals in South Korea

A Nationwide survey on the natural radioactivity in industrial raw mineral commodities (17 kinds of domestic and 18 kinds of imported) that are representative minerals used in production and consumption in South Korea was conducted. The target industrial minerals can be categorized into two groups. The first group covers non-metallic and metallic raw minerals with low levels of radioactivity such as clay, silica sand, carbonates, bituminous and anthracite coal, iron ores, ilmenite, rutile, and phosphate ore. The other group comprises minerals with high levels of radioactivity including zircon and monazite. One hundred and sixty-four domestic and imported samples were analysed by gamma-ray spectroscopy using an HPGe detector. The (40)K content ranges from <0.00131 to 2.69Bq g(-1), and (226)Ra and (232)Th range over <0.0006 to 0.630 and <0.0008 to 0.474Bq g(-1), respectively. There was no anthropogenic radioactive signal in any of the samples.

Cell cycle arrest and lytic induction of EBV-transformed B lymphoblastoid cells by a histone deacetylase inhibitor, Trichostatin A

Latent infection of the Epstein-Barr virus (EBV) is strongly associated with the pathogenesis of several human tumor types. The restricted expression of the latent EBV antigens is critical for EBV-associated tumors to escape from immune surveillance. EBV lytic replication can be triggered by various treatments and the induced lytic genes cause strong cytotoxic T lymphocyte (CTL) responses. Histone acetylation or deacetylation is associated with chromatin remodeling and regulates gene expression. Histone deacetylase (HDAC) inhibitors affect cell cycle progression as well as gene expression in a wide variety of transformed cells. We examined whether an HDAC inhibitor, TSA, can affect cell cycle progression and induce EBV lytic replication in EBV-transformed lymphoblastoid cell lines (LCLs). TSA caused cell cycle arrest at low concentrations and induced apoptosis at higher (>300 nM) concentrations in the LCLs and EBV negative BJAB cells. To clarify the underlying mechanism of TSA-induced cell cycle arrest, expression of cell cycle regulatory factors was examined by RNase protection assay and Western blot analysis. Following TSA treatment, a reduced expression of cyclin D2 and an induction of p21 may have played an essential role for G1 arrest in LCLs, while p21 induction might have arrested BJAB cells in G1 phase. A Cdk inhibitor, p57, was increased by 300 nM TSA in both LCLs and BJAB cells, indicating its role in apoptosis. Moreover, immunofluorescene assay and Western blotting showed that TSA induced EBV lytic replication in LCL cells. These results suggest that TSA may exert an enhanced anti-tumor effect for EBV-associated tumors not only by inducing a cell cycle arrest and apoptosis, but also by triggering an EBV lytic cycle.

Gene expression profiles in squamous cell cervical carcinoma using array-based comparative genomic hybridization analysis

Our aim was to identify novel genomic regions of interest and provide highly dynamic range information on correlation between squamous cell cervical carcinoma and its related gene expression patterns by a genome-wide array-based comparative genomic hybridization (array-CGH). We analyzed 15 cases of cervical cancer from KangNam St Mary's Hospital of the Catholic University of Korea. Microdissection assay was performed to obtain DNA samples from paraffin-embedded cervical tissues of cancer as well as of the adjacent normal tissues. The bacterial artificial chromosome (BAC) array used in this study consisted of 1440 human BACs and the space among the clones was 2.08 Mb. All the 15 cases of cervical cancer showed the differential changes of the cervical cancer-associated genetic alterations. The analysis limit of average gains and losses was 53%. A significant positive correlation was found in 8q24.3, 1p36.32, 3q27.1, 7p21.1, 11q13.1, and 3p14.2 changes through the cervical carcinogenesis. The regions of high level of gain were 1p36.33-1p36.32, 8q24.3, 16p13.3, 1p36.33, 3q27.1, and 7p21.1. And the regions of homozygous loss were 2q12.1, 22q11.21, 3p14.2, 6q24.3, 7p15.2, and 11q25. In the high level of gain regions, GSDMDC1, RECQL4, TP73, ABCF3, ALG3, HDAC9, ESRRA, and RPS6KA4 were significantly correlated with cervical cancer. The genes encoded by frequently lost clones were PTPRG, GRM7, ZDHHC3, EXOSC7, LRP1B, and NR3C2. Therefore, array-CGH analyses showed that specific genomic alterations were maintained in cervical cancer that were critical to the malignant phenotype and may give a chance to find out possible target genes present in the gained or lost clones.

Influence of VEGF gene polymorphisms on the severity of ankylosing spondylitis

OBJECTIVES

To investigate the role of polymorphisms of the vascular endothelial growth factor (VEGF) gene in susceptibility to ankylosing spondylitis (AS), and their relationship to clinical features and radiographic severity.

METHODS

This study included 157 patients with AS and 140 healthy unrelated controls. Polymorphisms of the VEGF gene were analysed by the polymerase chain reaction (PCR)-restriction fragment length polymorphism assay and amplification refractory mutation system-PCR. Haplotypes were reconstructed using the Bayesian algorithm. Radiographic severity was assessed by the Bath Ankylosing Spondylitis Radiological Index (BASRI).

RESULTS

The genotype frequencies of the polymorphisms were in Hardy-Weinberg equilibrium. The distributions of genotypes and alleles did not differ between AS patients and controls. Among the six haplotypes reconstructed based on the tight linkage disequilibrium at positions -2578, -1154 and -634 (pairwise linkage disequilibrium coefficient, r = 0.361-0.706), no haplotype was associated with susceptibility to AS. Clinical features were analysed for the four haplotypes (CGC, CGG, AAG, AGG) which were prevalent. In carriers of the AGG haplotype, the frequency of cervical spine involvement was significantly higher (P = 0.002, P(corr) = 0.036) and that of patients showing a BASRI score >6 was also higher (P = 0.025, P(corr) = 0.45).

CONCLUSIONS

This study demonstrates that polymorphisms of the VEGF gene may contribute to disease severity in AS.

VEGF gene polymorphisms and susceptibility to rheumatoid arthritis

OBJECTIVES

To investigate polymorphisms of the VEGF gene in patients with rheumatoid arthritis (RA), their relationship to clinical features and the radiographic progression of joint disease.

METHODS

One hundred and forty patients with RA and 149 healthy unrelated controls were recruited. We examined four polymorphisms of the VEGF gene which are reported to be associated with production of vascular endothelial growth factor (VEGF), using polymerase chain reaction (PCR) restriction fragment length polymorphism assay and amplification refractory mutation system (ARMS) PCR. Haplotypes were predicted by Bayesian algorithm using the Phase program.

RESULTS

All four polymorphisms were in Hardy-Weinberg equilibrium in both patients and controls. The frequency of the 936 T allele, which has been associated with lower production of VEGF, was significantly increased in RA patients compared with controls (22.7 vs 13.4%, P = 0.002). The frequencies of two haplotypes (CGCT and AAGT) which were predicted using the Phase program were significantly increased in RA patients compared with controls [33 vs 14%, odds ratio (OR) 2.636, 95% confidence interval (CI) 1.38-5.04 for CGCT; 17 vs 6%, OR 3.08, 95% CI 1.20-7.92 for AAGT]. The carriers of the susceptible haplotypes in RA patients had a younger age at disease onset but did not show a difference in the progression rate of radiographic joint destruction.

CONCLUSIONS

Our data suggest that the VEGF gene may play a role in the development of RA

Comparative analysis of superfamilies of NBS-encoding disease resistance gene analogs in cultivated and wild apple species

Eleven distinct families of resistance gene analogs (RGAs) with the characteristic nucleotide-binding sequence (NBS) were identified in two wild apple species, Malus prunifolia and M. baccata, and two cultivated apple cultivars, M. domestica cv. Fuji and M. domestica cv. Hong-ok, using PCR approaches with degenerate primers based on two conserved motifs of known NBS-LRR resistance genes. These RGA families were found to be represented in all the apple species tested, including wild and cultivated species. However, their sequences are very divergent from each other. Furthermore, the low level of recombination detected within their RGA families supports the idea that the evolution of NBS-encoding sequences in apple species involves the gradual accumulation of mutations. Despite the high diversity of the RGA families found in all apple species, the apparent lack of differentiation between wild and cultivated forms suggests that other factors, such as the capacity to tolerate pathogens, might play an important role in the survival of wild-type species.

Genetic polymorphisms of cytochrome P450 19 and 1B1, alcohol use, and breast cancer risk in Korean women

A case-control study was performed to assess the potential influence of CYP19 Arg(264)Cys and CYP1B1 Leu(432)Val polymorphisms on breast cancer risk in a series of Korean breast cancer patients and controls. The results suggest that the CYP19 Arg(264)Cys polymorphism modifies breast cancer risk (OR=1.5, 95% CI=1.1-2.2), especially in association with alcohol consumption (P for interaction=0.04), whereas the CYP1B1 Leu(432)Val polymorphism appears to play no role here.

Targeted hsp70.1 disruption increases infarction volume after focal cerebral ischemia in mice

BACKGROUND AND PURPOSE

Heat-shock proteins (HSPs) are highly conserved proteins that are induced by a variety of stresses. HSP70 is a 70-kDa HSP family known to have cytoprotective effects against various insults. The role of HSP70 in cerebral ischemia remains to be elucidated in vivo.

METHODS

To investigate the effect of reduced HSP70 levels on cerebral ischemia, focal cerebral ischemia by intraluminal occlusion of the middle cerebral artery was induced in hsp70.1 knockout mice. The expressions of hsp70.1 and hsp70.3 mRNAs and HSP70 protein were determined, and infarction volumes were measured and compared.

RESULTS

Northern blots confirmed the absence of hsp70.1 mRNA expression in the knockout mice. The mean infarction volume was significantly larger in hsp70.1 knockout mice (92.5+/-8.3 mm(3)) than in the wild-type mice (59.3+/-8.9 mm,(3) P<0.001). Western blots showed increased HSP70 expression in the ischemic hemisphere in both knockout and wild-type mice, but HSP70 expression levels in knockout mice were significantly lower than those in their wild-type littermates. Immunohistochemistry did not show any significant differences between the knockout and wild-type animals and showed increased HSP70 immunoreactivity in the ischemic hemisphere, with predominance in the cerebral cortex, especially in the penumbra.

CONCLUSIONS

Our results suggest that hsp70.1 plays an important role in the early protection of the brain, at least after acute focal cerebral ischemia in mice.

Effect of the absence of heat shock protein 70.1 (hsp70.1) on retinal photoreceptors in normal and rd mice

The purposes of this study are to elucidate the retinal changes of heat shock protein 70.1 (hsp70.1) knockout mice and to compare them between in normal and in retinal degeneration (rd) mice. Eyes of hsp70.1 wild type (+/+) and knockout (-/-) mice in the C57BL/6 or FVB genetic backgrounds respectively, which were reared in the normal environment, were examined by fundus photography, electroretinography, light microscopy, terminal dUTP nick-end labeling (TUNEL) stain, and immunohistochemistry. In C57BL/6 mice, fundus photography showed no changes between hsp70.1+/+ and -/- mice at 1 and 6 months of age. Electroretinographic examination showed a tendency of decreased amplitude of a- and b-wave with aging in both genotype, but there were not different statistically. The ratios of the thickness of inner nuclear and outer nuclear layer to the retinal thickness were respectively decreased with aging in both genotype, but there were not different statstically. TUNEL assay showed a few positively labeled cells in the ganglion cell, inner nuclear and outer nuclear layers and the immunohistochemistry showed no immunopositivity of hsp70 in the inner segments of photoreceptor cell layer in both genotype. In rd mice, fundus photography showed a narrowing of the retinal vessels at the age of 4 weeks, however, there were no differences of retinal changes including pigment epithelial layer in both genotype. Electroretinographic examination at the postnatal 2, 3 and 4 weeks showed no differences between them. Loss of photoreceptor cell and outer nuclear layers showed no differences in both genotype. In conclusion, there were no differences of the retinal changes at least under the normal environmental condition in hsp70.1+/+ and -/- mice. These results show that hsp70.1-/- mice can be used to study the role of hsp70.1 to the external stress to the retina.

Gene profile of replicative senescence is different from progeria or elderly donor

In vitro cellular senescence of human diploid fibroblast has been a good model for aging research, which shows similar phenotypes to in vivo aging. Gene expression profiling would provide an insight to understand the mechanism of senescence. Using cDNA microarray containing 384 known genes, we compared the expression profiles of three different types of aging models: replicative senescence, fibroblasts from progeria or from elderly donor. Although all of them showed senescence phenotypes, distinct sets of genes were altered in each group. Pairwise plots or cluster analysis of activation fold of gene expression revealed closer relationships between fibroblasts from progeria or from old individual, but not between replicative senescence fibroblasts and either models. Differential expression pattern of several genes were confirmed by RT-PCR. We suggest that the replicative senescence model might behave differently to other types of aging models due to the distinct gene expression.

The effect of oxygen on retinal degeneration in wild-type and hsp70.1 knockout neonatal retinal degeneration mice

The present study examined the effect of oxygen on photoreceptor degeneration in the retina of heat shock protein 70.1 (hsp70.1) knockout type and wild-type retinal degeneration (rd) mice. All the neonatal rd mice were exposed to hyperoixa for 5 days after birth, and then were returned to room air before being sacrificed. At the postnatal 10, 14, 18, and 21 days, the ratio of outer nuclear layer (ONL) thickness to total retinal thickness was compared between hsp70.1 knockout type and wild type. The retina was also examined for DNA fragmentation by TdT-mediated biotin-dUTP nick-end labeling (TUNEL). In hsp70.1 knockout type, the ratio of ONL to total retinal thickness was higher than that in the wild type at each time. There was the remarkable difference in the number and distribution of TUNEL-positive cells between hsp70.1 knockout type and wild type rd mice. In conclusion, an oxygen-induced modulation of the rate of photoreceptor degeneration was more marked in the hsp70.1 knockout type than wild type rd mice.

Generation of fusion genes carrying drug resistance, green fluorescent protein, and herpes simplex virus thymidine kinase genes in a single cistron

We generated new fusion genes carrying positive- and negative-selection markers, and a reporter gene in a single reading frame. The new genes were constructed by sequentially linking the coding sequences of drug-resistance genes (hygro, or puro), a green fluorescence protein (GFP) gene (gfp), and the thymidine kinase gene (tk). The new synthetic genes (hygro/gfp/tk and puro/ gfp/tk) were inserted into retroviral vectors to test their usefulness as selective markers and reporters. The genes were functional in a positive selection in the presence of hygromycin (hygro/gfp/tk) or puromycin (puro/gfp/ tk). In addition, cells expressing the new fusion genes were clearly identifiable by their green fluorescence emitted from GFP. At the same time, these cells were sensitive to a gancyclovir treatment, allowing efficient removal of the transduced cells. The presently described synthetic genes will be valuable tools in both gene therapy and basic gene transfer studies, where positive selection of the transduced cells, monitoring gene expression, and negative selection of the transduced cells are simultaneously required.

Relationship between normal heart size and body indices in Korean

We provided a curve-fit equation to predict the normal heart weight (g) in Koreans by examining 422 autopsies (215 males and 207 females, from newborn to age 77 yr) who were relatively in good general condition. Heart weight was well correlated with body surface area (m2), body weight (kg), and body height (cm) but poorly with age in both sex. Heart weight progressively increased from birth to the earlier 3rd and 4th decades in male and female, respectively, and then gradually decreased; mean heart weight of all age group was greater in male than in female and significantly different from birth to 4th decade. In both sex, heart weight exponentially increased in accordance with the increase of body height, body weight, and body surface (in male, heart weight=0.00312 x body height(2.239), r2=0.750, p<0.0001; in female, heart weight=0.00443 x body height(2170), r2=0.781, p<0.0001; in male, heart weight=9.22 x body weight(0.853), r2=0.770, p<0.0001; in female, heart weight=9.00 x body weight0.855, r2=0.820, p<0.0001; in male, heart weight=155.18 x body surface area1.290, r=0.808, p<0.0001; in female, heart weight=124.13 x body surface area1.242, r=0.834, p<0.0001). These results indicate that heart weight is better correlated with body surface area than with body weight; however, body weight should be a better determinant of a predicted heart weight, since body surface area is entirely dependent on body height and body weight.

Development of spontaneous hyperplastic skin lesions and chemically induced skin papillomas in transgenic mice expressing human papillomavirus type 16 E6/E7 genes

Human papillomavirus type 16 (HPV16) has been known to be the major factor for the development of uterine cervical carcinomas. We have developed a line of transgenic mice that express the HPV16 E6 and E7 genes in certain organs using a fusion gene which consists of the tyrosinase promoter and E6/E7 of HPV16, and have chosen the tyrosinase minigene as a co-injected visual marker for the identification of transgenic mice. Our transgenic mice (1) expressed E6/E7 transgene mainly in skin and heart, and (2) showed skin and eye pigmentation profiles, and (3) raised incidence of hyperplastic skin lesions. We had performed two-stage skin carcinogenesis experiment to detect the susceptibility of skin papilloma development in our transgenic mice, using dimethylbenz-anthracene (DMBA) as a initiating agent and 12-O-tetradecanoyl-phorbol-13-acetate (TPA). After 1 week of DMBA treatment (25 microg dissolved in 0.2 ml acetone) and 15 consecutive weeks of TPA treatment (2.5 microg dissolved in 0.2 ml acetone) on the back of transgenic and non-transgenic control mice (Fv-1(b) strain mice which are Friend virus B-type susceptible (FVB)/N), papilloma incidence was increased in our transgenic mice approximately 2-fold higher than in control (in female mice, 69.2 vs. 30%, respectively). Thus our transgenic mice may be useful for the development of immunological or other therapies for HPV-associated cancers.

Production and characterization of a monoclonal antibody specific to the human 70-kDa heat shock protein

Heat shock protein 70 (hsp 70) plays major roles in apoptosis prevention and thermotolerance as well as molecular chaperoning. It is also expressed on the surface of human tumor cells, but not on normal cells, suggesting that hsp70 may be some tumor-associated antigen. To investigate the diverse functions of the protein species, various types of transgenic mice or cell models overexpressing human hsp70 have been made. In these models a monoclonal antibody (MAb) specific for the human hsp70 is highly desirable to distinguish the human from the endogenous mouse hsp70. It proved difficult to make this species-specific MAb, because the hsp70 homologues are members of a family of highly conserved, abundant, and ubiquitous proteins expressed in organisms ranging from bacteria to humans. In the present study, we prepared four MAbs against human hsp70. Three, HD 5, HD 7 and HD 11, recognize human and mouse hsp70. One, though, HD 8, recognizes human hsp70, but not mouse hsp70. By Western blot analysis of hsp70 deletion mutants, the epitope of the HD 8 MAb was determined as the 585-616 amino acid region of the human hsp70, a region with relatively low homology to mouse hsp70.

Overexpression of HSP70 prevents ultraviolet B-induced apoptosis of a human melanoma cell line

The heat shock response is a highly conserved reaction common to all cells and organisms. It has been reported that hyperthermic treatment can induce the expression of the heat shock protein (HSP) and can protect cells from ultraviolet (UV) B radiation. In this study, we evaluated the effects of induced HSP70 on resistance to UV radiation. G361 amelanotic human melanoma cells were irradiated with increasing doses of UVB. UVB irradiation caused apoptotic cell death in these cells. Following transfection with MFG.hsp70.puro plasmid, the expression of HSP70 was determined. Compared to control vector-transfected cells, hsp70-transfected cells showed significantly elevated levels of HSP70 and were highly resistant to UVB irradiation. In order to investigate the effects of HSP70 on the apoptotic pathway, the changes in caspase-3 and PARP were analyzed. Following UVB irradiation, activation of caspase-3 and cleavage of PARP were observed in control vector-transfected cells, and the changes in these molecules were inhibited in the hsp70-transfected cells. These results suggest that UVB-induced apoptosis of melanoma cells is accompanied by caspase-3 activation and PARP cleavage, which can be prevented by an overexpression of HSP70.

Heat shock protein 70 inhibits apoptosis downstream of cytochrome c release and upstream of caspase-3 activation

Heat shock protein 70 (HSP70) has been shown to act as an inhibitor of apoptosis. We have also observed an inhibitory effect of HSP70 on apoptotic cell death both in preheated U937 and stably transfected HSP70-overexpressing U937 (U937/HSP70) cells. However, the molecular mechanism whereby HSP70 prevents apoptosis still remains to be solved. To address this issue, we investigated the effect of HSP70 on apoptotic processes in an in vitro system. Caspase-3 cleavage and DNA fragmentation were detected in cytosolic fractions from normal cells upon addition of dATP, but not from preheated U937 or U937/hsp70 cells. Moreover, the addition of purified recombinant HSP70 to normal cytosolic fractions prevented caspase-3 cleavage and DNA fragmentation, suggesting that HSP70 prevents apoptosis upstream of caspase-3 processing. Because cytochrome c was still released from mitochondria into the cytosol by lethal heat shock despite prevention of caspase-3 activation and cell death in both preheated U937 and U937/hsp70 cells, it was evident that HSP70 acts downstream of cytochrome c release. Results obtained in vitro with purified deletion mutants of HSP70 showed that the carboxyl one-third region (from amino acids 438 to 641) including the peptide-binding domain and the carboxyl-terminal EEVD sequence was essential to prevent caspase-3 processing. From these results, we conclude that HSP70 acts as a strong suppressor of apoptosis acting downstream of cytochrome c release and upstream of caspase-3 activation.

Up-regulation of caveolin attenuates epidermal growth factor signaling in senescent cells

Senescent human diploid fibroblasts do not respond to growth factors like epidermal growth factor (EGF), although they have a normal level of receptors and downstream signaling molecules. To examine the mechanism of signaling attenuation, we investigated Erk activation after EGF stimulation in senescent cells. Senescent cells did not phosphorylate Erk-1/2 after EGF stimulation, whereas young cells did. In those senescent cells, we found an increased level of caveolin proteins and strong interactions between caveolin-1 and EGF receptor. Electron microscopic analysis demonstrated an increased number of caveolae structures in senescent cells. More interestingly, brain, spleen, and lung from 26-month-old rats showed substantial increases of caveolin proteins. However, in the case of p53-induced senescence, caveolin-1 was not induced, and EGF stimulation phosphorylated Erk-1/2 as much as young control cells. Finally, we overexpressed caveolin-1 in young human diploid fibroblasts in which the activation of Erk-1/2 upon EGF stimulation was significantly suppressed. These results suggest that the unresponsiveness of senescent fibroblasts to EGF stimulation may be due to the overexpression of caveolins, which seems to be independent of growth arrest and other aging phenotypes.

Acoustic scattering from two circular apertures in a thick hard plane

A problem of acoustic wave scattering from two circular apertures in a thick hard plane is solved. The Hankel transform and mode matching is used to represent the scattered field in rapidly convergent series. The reflection coefficient, transmission coefficient, and far-zone field are rigorously derived and presented in numerically efficient forms. Numerical computations are performed to illustrate scattering behaviors in terms of aperture geometry.

Caveolin internalization by heat shock or hyperosmotic shock

We investigated the cellular localization of caveolin, a landmark protein of caveolae, by indirect immunofluorescence after heat shock or hyperosmotic shock. Caveolin was internalized to the perinucleus by heat shock (43 degrees C) and relocalized in the plasma membrane after recovery of NIH3T3 cells at 37 degrees C for 4 h. The caveolin internalization was also observed after cells were exposed to hyperosmotic shock. Caveolin disappeared from detergent-insoluble complexes in the heat-shocked cells, but alkaline phosphatase was still there, suggesting that their responses to heat shock are quite different even though both of them were enriched in detergent-insoluble complexes of normal cells. Caveolin was internalized by the actin depolymerizer cytochalasin D, but not by the tubulin depolymerizer nocodazole. In addition, cellular exposure to hydrogen peroxide caused caveolin internalization along with disintegrated microfilaments and intact microtubules. Since cellular exposure to heat shock showed disintegrated microfilaments but intact microtubules, caveolin internalization might be due to depolymerized microfilaments. When cells were exposed to heat shock and allowed to recover for 4 h, actin depolymerization and caveolin internalization were not induced by a second heat shock, suggesting that some heat shock protein(s) might prevent actin depolymerization and caveolin internalization.

TNF-alpha-mediated apoptosis is initiated in caveolae-like domains

Caveolae-like domains (CLDs) have been hypothesized to mediate apoptosis, since they contain sphingomyelin and initiate the conversion of sphingomyelin to ceramide. To address whether CLDs are directly involved in apoptosis, CLDs from U937 cells were isolated, taking advantage of their detergent insolubility and low density. The CLDs contained alkaline phosphatase as well as many signaling molecules, including Fyn, protein kinase Calpha, Raf-1, phospholipase Cgamma1, and tyrosine phosphoproteins. Immunoblotting and immunofluorescent data showed that TNF receptor 1 colocalized with CD36 in CLDs, suggesting that TNF-alpha-initiated apoptosis occurs in CLDs. When cells were incubated with lipoprotein-deficient medium, the cholesterol concentration was greatly decreased in CLDs but not in other fractions, implying that the CLDs were selectively disrupted. In the CLD-disrupted cells, the surface expression of TNF receptor 1 and CD36 was significantly reduced. Analysis of cellular morphology, percent DNA fragmentation, DNA laddering, and caspase-3 activity showed that TNF-alpha-mediated apoptosis was blocked in CLD-disrupted cells, whereas anti-Fas-mediated apoptosis was not. Since Fas was not found in CLDs of Jurkat cells, apoptosis by Fas ligation might not require CLDs. Taken together, these data strongly imply that TNF-alpha-mediated apoptosis is initiated in CLDs.

Suppression of ceramide-mediated apoptosis by HSP70

Ceramide has been known as an important second messenger in programmed cell death (apoptosis) which is induced by various stimuli such as the tumor necrosis factor-alpha (TNF-alpha), Fas ligand, and environmental stresses such as UV-irradiation and heat shock. Although the precise molecular mechanism of apoptosis is not fully understood, ceramide generated by sphingomyelinase (SMase) mediates the activation of several downstream molecules that are implicated in the regulation of apoptosis. Here, we show that stress-inducible heat shock protein 70 (Hsp70) prevents apoptosis induced by increased level of intracellular ceramide. In T-cell hybridoma DO11.10, we examined the effect of Hsp70 on apoptosis mediated by TNF-alpha, Fas ligation, SMase, and C2-ceramide, all of which elevate intracellular ceramide levels. Hsp70 not only markedly reduced internucleosomal DNA fragmentation, but also enhanced cell viability measured by the Trypan blue dye exclusion test. Similarly, the ceramide-induced c-jun amino-terminal kinase (JNK/SAPK) activation is impaired in cells overexpressing Hsp70. These data strongly suggest that hsp70 functions as a regulator of apoptosis downstream of ceramide.

A novel parvovirus isolated from Manchurian chipmunks

A novel parvovirus was identified in Manchurian chipmunks inhabiting Korea. Hepatitis B surface antigen (HBsAg) was detected in sera from 4 animals among 62 apparently healthy chipmunks. Electron microscopic examination of the HBsAg-positive sera revealed virus-like spherical particles 20-22 nm in diameter. Extraction of nucleic acid under annealing conditions from the serum samples containing virus-like particles yielded a single species of DNA molecule with the electrophoretic mobility of 5.6-kb double-stranded DNA. Four overlapping clones that encompassed almost the full-length viral genome, except both ends, were obtained. By sequencing these clones, we determined the sequence of 5097 nucleotides of the viral DNA. Two open reading frames were identified, with the left side open reading frame encoding a putative nonstructural protein and the right side open reading frame encoding a putative capsid protein. The nucleotide and amino acid sequences showed significant homology to parvovirus B19 and simian parvovirus, but showed little homology to other mammalian autonomous parvoviruses or adeno-associated viruses. These observations indicate that the virus isolated from Manchurian chipmunks is a novel parvovirus and may be a potentially useful animal model of human B19 infection as a new member of the Erythrovirus genus of the Parvoviridae.

Expression of heat shock protein 70 blocks thymic differentiation of T cells in transgenic mice

Heat shock protein 70 (HSP70) is involved not only in protein folding, but also in processes of differentiation and cell-cycle progression. Recently, HSP70 has been implicated in mediation of functions of some immunosuppressive agents. To study the role of HSP70 in differentiation of haematopoietic cells, we generated transgenic mice using the human inducible hsp70 gene fused to the mouse H-2K promoter. These mice develop a T-cell deficiency that is characterized by thymic hypoplasia and a significant reduction in peripheral T cells. The total number of thymocytes is about 100-fold less than that in normal mice. The majority of the thymocytes are immature T cells that express neither CD4 nor CD8 molecules, indicating that T cells are affected at an early stage of thymic differentiation. Expression of the transgenic HSP70 was detected both in bone marrow cells and in thymocytes. Furthermore, injection of normal bone marrow cells into the T-cell deficient mice led to the generation of mature T cells indicating that the T-cell deficiency was caused by the action of HSP70 in T cells. The blockage of differentiation occurred only in T cells, both alphabeta- and gammadelta-T-cell receptor (TCR)-bearing cells, but not in B cells, granulocytes, and monocytes. The observations suggest that HSP70 may inhibit a cellular process that is essential for the differentiation of early stage T cells. Further experiments using this model system will widen our understanding of HSP70 and its function on a molecular level.

Tissue-specific expression and activation of N-methylpurine-DNA glycosylase in thymic carcinomas of transgenic mice expressing the SV40 large T-antigen gene

Simian virus 40 T-tumor antigen (SV40 T-ag) can induce a wide variety of tumors in hamsters and neonatal mice. These tumorigenic effects are predominantly due to the activity of early viral gene products, large T-antigen and small t-antigen. We have analyzed the expression of a DNA repair gene, N-methylpurine-DNA glycosylase (MPG), from different tissues of a non-transgenic (control) and SV40 T-ag expressing transgenic mice at the mRNA level. Expression of the transgene in thymus of adult mice was also detected by the presence of SV40 T-ag mRNA. Non-transgenic mice did not express the SV40 T-ag gene in their thymus, while the mRNA for MPG was found in thymus from both of transgenic and non-transgenic mice. The MPG gene was expressed in various tissues and is regulated in a tissue-specific manner. Northern blot analysis revealed that the transgenic mice showed considerably higher expression of MPG in the thymic carcinomas. The level of MPG mRNA in the thymic carcinoma was elevated about 5.7 fold, as compared with those found in the control thymus. MPG expression was significantly increased, either directly or indirectly, by the SV40 T-ag gene product. These findings provide the first in vivo observations that the SV40 T-ag gene induced thymic carcinomas associated with the activation of the DNA repair gene, MPG.

Granulocytic sarcoma as isolated extramedullary relapse after donor lymphocyte infusion in a patient with CML who relapsed after allogeneic bone marrow transplantation: a case report

Isolated granulocytic sarcoma (GS) has rarely been reported in a patient who underwent allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia (CML). We report here a patient who developed an isolated GS after achieving hematologic and cytogenetic remission by donor lymphocyte infusion for the relapse of CML following BMT. The size of GS was slightly decreased after local irradiation of 1,500 cGy without further systemic chemotherapy or immunotherapy. He remained in hematologic and cytogenetic remission without systemic relapse of CML for 8 months. Thereafter, he died of sepsis. The appropriate treatment of GS and impact of its occurrence on prognosis following allogeneic BMT has yet to be determined.

The role of inducible 70-kDa heat shock protein in cell cycle control, differentiation, and apoptotic cell death of the human myeloid leukemic HL-60 cells

Several studies have suggested a role for heat shock proteins (hsps) during development and differentiation. However, relatively little is known about the role of hsp70 in controlling human hematopoietic cell differentiation and death. Here, we show that constitutive expression of human inducible 70-kDa heat shock protein (hsp70) promotes differentiation of HL-60 cells and prevents apoptosis that occurred after terminal differentiation or directly by apoptotic agents. After treatment with phorbol 12-myristate 13-acetate (PMA), hsp70-overexpressing cells (HL-60/hsp70) underwent rapid growth arrest and plastic adherence and expressed more CD14 than parental HL-60 or empty vector-transformed cells (HL-60/puro). HL-60/hsp70 cells also rapidly differentiated into granulocytes by addition of all-trans-retinoic acid, as assessed by phenotypic changes after staining with Wright-Giemsa. After differentiation into monocyte/macrophage-like cells or granulocytes, hsp70-overexpressing cells showed little evidence for apoptosis and had a prolonged survival, indicating that the survival-enhancing properties of hsp70 counteract programmed cell death that accompanies terminal differentiation. HL-60/hsp70 cells also showed more resistance than parental cells against apoptotic agents such as sodium nitroprusside, a NO-generating agent, or Taxol, a microtubule stabilizing agent. Further, heat shock of parental HL-60 cells at 42 degrees C for 3 h increased hsp70 levels, promoted plastic adherence (< 6 h) of the cells in respond to PMA, and protected cells from SNP or Taxol. Taken together, these studies demonstrate that hsp70 plays a crucial role in the differentiation of myeloid cells, participating in cell cycle controls and phenotypic changes, with protecting effects on apoptosis induced by different pathways.

c-Fes tyrosine kinase binds to and activates STAT3 after granulocyte-macrophage colony-stimulating factor stimulation

Granulocyte-macrophage colony stimulating factor (GM-CSF) induces proliferation and maturation of myeloid progenitor cells and also activates neutrophils. In order to investigate the pleiotropic effects of GM-CSF stimulation, we examined the signaling pathways of protein tyrosine kinases (PTKs) and signal transducers and activators of transcription (STATs) in GM-CSF-dependent proliferation of leukemia cells. Using TF-1, a GM-CSF-dependent human erythroleukemia cell line, we found that GM-CSF enhanced DNA-binding and tyrosine phosphorylation of STAT3. GM-CSF receptor (GM-CSFR) and c-Fes tyrosine kinase were also activated upon GM-CSF stimulation. Furthermore, c-Fes formed a complex with STAT3. Experiments using a c-Fes mutant that lacked tyrosine kinase activity revealed that the activation of STAT3 is kinase-dependent, but that the c-Fes-STAT3 interaction is not affected by c-Fes tyrosine kinase activity. The results suggest that STAT3 is activated by c-Fes tyrosine kinase through direct interaction during hematopoietic cell proliferation induced by GM-CSF.

A case of Marfan syndrome with acute monoblastic leukemia

We report on an 18-year-old man who had both acute monoblastic leukemia and Marfan syndrome. A diagnosis of Marfan syndrome was established by those characteristics of arachnodactyly, ectopia lentis, mitral valve prolapse, and mitral regurgitation. Findings on bone marrow examination of the patient showed that most of nucleated cells were monoblasts and immunophenotype of those cells showed CD13+, CD33+, CD56+, and HLA-DR+. To our knowledge, this is the second report of leukemia in Marfan syndrome in the world.

Tendinous insertion of semimembranosus muscle into the lateral meniscus

Forty-two cadaver knees were used for morphologic and MRI observations of the tendinous distal expansions of the semimembranosus m. and the posterior capsular structures of the knee. A tendinous branch of the semimembranosus m. inserting into the posterior horn of the lateral meniscus was found in 43.2% of the knees dissected, besides five already known insertional branches; capsular, direct, anterior and inferior, as well as the oblique popliteal ligament. The tendon had three morphologic types; thin, broad and round. All three types moved the lateral meniscus posteriorly when pulled on. Thus, the semimembranosus m. may also have a protective function for the lateral meniscus as well as the already well established function of protecting the medial meniscus in knee flexion. When a semimembranosus tendon attachment to the posterior horn of the lateral meniscus is present, its normal insertion is difficult to differentiate from a lateral meniscus tear in MRI and this may cause misdiagnosis.

A case of chronic graft-versus-host-disease following allogeneic peripheral blood stem cell rescue for poor graft function after bone marrow transplantation

To overcome poor graft function after allogeneic bone marrow transplantation (BMT), the use of peripheral blood stem cells (PBSC) instead of bone marrow is gaining more popularity because of its advantages. There may, however, be an increased risk of graft-versus-host-disease (GVHD) because of the large number of lymphocytes present in a leukapheresis product. An 18-year-old man with severe aplastic anemia underwent an allogeneic BMT using his HLA-identical sister. After initial excellent graft take for 8 months, his blood counts gradually decreased to 2.8 x 10(9)/L of white cells and 28 x 10(9)/L of platelets with marrow cellularity of < 10%. After allogeneic granulocyte-colony stimulating factor mobilized PBSC rescue, the patient's blood counts recovered satisfactorily. Around 1 year after the boost, he developed chronic GVHD that responded to prednisolone and cyclosporin A. He is now well on low-dose steroids at day +1055 after PBSC rescue. The present case is the first experience of a long-term follow-up who underwent allogeneic PBSC rescue in Korea.

Thymic epithelial tumor progression in an SV40T transgenic mouse model. Cortical thymoma-thymic carcinoma sequence

There have been several reports that thymoma in human is a progressive disease, and that thymoma and thymic carcinoma form a continuum. We established a stable line of SV40T transgenic mice, which consistently produced thymic epithelial tumours progressing to thymic carcinoma within a predictable time span. Using this animal model and a morphological approach, thymic epithelial tumour progression was studied with reference to sequential changes at different time points in animals aged from 3 to 32 weeks. At all ages, SV40T was expressed in the nuclei of thymic epithelial cells; in these transgenic mice we observed the entire spectrum from cortical type thymoma to thymic carcinoma. Thymic size tended to increase with ageing in SV40T TG mice. While younger mice had predominantly cortical (organoid) or cortical thymoma, older mice had well-differentiated thymic carcinoma (WDTC) or poorly differentiated thymic carcinoma. When SV40T TG mice (248 line) reached a certain age, carcinoma of the thymus was present in all of them. Cortical-type thymoma became malignant within a predictable time span, suggesting a cortical thymoma-carcinoma sequence. When the mice were 9 weeks of age, the thymuses formed gross masses compatible with cortical thymoma. At 14 weeks of age, WDTC appeared against the background of cortical thymoma. Poorly differentiated thymic carcinoma was found after 15 weeks and affected all animals over 23 weeks of age. Most thymic carcinomas coexisted in varying proportions with cortical-type thymoma. Medullary thymomas did not develop in the mice, and no transition from medullary-type thymomas to thymic carcinomas was observed. In this SV40T transgenic mouse model, thymic carcinoma is clearly preceded by cortical-type thymoma. These transgenic mice may provide an interesting model for the progression from cortical thymoma to WDTC and/or high-grade carcinoma.

Development of thymic carcinoma in transgenic mice expressing SV40 T antigen

We produced transgenic mice using SV40 Tag gene under the control of its own enhancer and promoter. Three transgenic lines (SNU-SVT125, 127, 248) consistently developed thymic carcinoma as well as choroid plexus carcinoma and dysplastic renal tubule. In SNU-SVT248 line, SV40 Tag transgene was expressed at thymus, spleen and kidney. Thymic epithelium showed high level expression of SV40 Tag in immunohistochemistry. Histopathological and electron microscopic analysis revealed that poorly differentiated carcinoma was derived from type 2 to 4 thymic epithelial cell. Our transgenic mice would provide a model for studies on the pathogenesis of thymic carcinoma and on the regulation of thymopoiesis by epithelial cells.

Alterations of the thymic selection process in transgenic mice expressing SV40 large T antigen

We generated SV40 T antigen transgenic mice (lines SVT125, SVT127, and SVT248) which developed unique thymic carcinomas originating from thymic cortical epithelial cells. In these mice we observed alterations in the thymic selection process not reported before in SV40 T antigen transgenic mice. Along with tumor cell growth, thymocytes increased in number and the proportion of CD4 or CD8 single positive cells rose to 10 times the normal level. Expression of SV40 T antigen was detectable by Northern analysis in thymic stromal cells but not in thymocytes. Thymic stromal cell lines, derived from the thymic tumor, produced high levels of cytokines which caused morphological transformation and growth stimulation in hematopoietic stem cells, including fetal liver cells and bone marrow cells. These observations suggest that the unusual multiplication of thymocytes and the alterations in thymic selection are the result of the activity of thymic stromal cells transformed by SV40 T antigen. The cell lines derived from the tumor can thus be used to study cytokines involved in thymic differentiation of T cells.

T cell lymphoma in transgenic mice expressing the human Hsp70 gene

In the course of studying the role of hsp70 in the differentiation of pancreatic beta cells, transgenic founder mice were generated with the human hsp70 gene fused to the human insulin gene promoter. One resulted in a transgenic line that consistently developed diabetes mellitus, but unexpectedly three other independent transgenic founders developed generalized malignant lymphoma within 10 months after birth. Immunochemical and RT-PCR analyses revealed that the transgene was expressed in the lymphoma cells. Flow cytometric analyses revealed that the tumor was originated from T lymphocytes. Our results provide the first experimental evidence that hsp70 is involved in the tumorigenesis of T cells most likely through the blockage of apoptotic signals.

Combined free flap, Ilizarov lengthening and prosthetic fitting in the reconstruction of a proximal forearm amputation--a case report

A composite free latissimus dorsi musculocutaneous flap combined with Ilizarov lengthening was used in the resurfacing of the elbow and the reconstruction of the forearm following a very proximal below elbow amputation with soft tissue degloving to the level of the mid arm. The free flap provided gliding soft tissue to the elbow joint, and the deep fascia and muscle components of the flap were contoured round the bony stump so as to allow bone transport within the soft tissue envelope. The lengthening achieved was 14 cm with no bone resorption at the end of the stump. The reconstructed forearm, with a well-contoured stump covered with durable and adherent soft tissue, allowed the fitting of a forearm-based lightweight hand glove prosthesis. With the combined modalities of microsurgical free tissue transfer, the Ilizarov method of slow distraction and prosthetic fitting, we were able to achieve restoration of both form and function in a difficult case of major upper extremity amputation.

Leucine zipper-like domain regulates the autophosphorylation and the transforming activity of P130gag-fps

P130gag-fps, the product of Fujinami sarcoma virus, has a leucine zipper (LZ) motif located in 729-756 amino acid residues. To explore the role of LZ-like domain in the transformation by P130gag-fps, we made a deletion (delta FpsLZ/SH2) and a site-directed substitution mutation (L746P). Deletion mutant did not transform the 3Y1 cells and the resulting protein did not show kinase activity. Substitution of Leu746 with Pro (L746P) reduced the transforming activity by 6-fold. Although the L746P mutant retained intact catalytic activity in vitro, it did not phosphorylate cellular proteins in vivo. We concluded that LZ-like domain might mediate the trans-activation of P130gag-fps tyrosine kinase by autophosphorylation, which is prerequisite for the transforming activity.