Prevalence of erectile dysfunction in Korean men with Type 2 diabetes mellitus

AIMS

We investigated the prevalence and risk factors for developing erectile dysfunction (ED) in 1312 Korean men with diabetes in a multicentre study.

METHODS

We used the modified International Index for Erectile Function-5 criteria to identify mild, moderate and complete ED. A standardized face-to-face questionnaire was used by trained interviewers, and validated against telephone interviews. We recorded the duration of diabetes, level of glycaemic control, vital signs, complications, exercise and alcohol and smoking habits, and diabetes treatments used. Results The mean age and median duration of diabetes were 53.8 +/- 6.65 and 6 years (range 1-43), respectively. The mean HbA(1c) and fasting glucose levels were 7.9 +/- 1.65% and 8.6 +/- 2.82 mmol/l, respectively. The overall prevalences of mild, moderate, complete ED and all ED (mild-to-complete) were 20.1, 19.5, 25.8 and 65.4%, respectively. ED was more common with age, reaching 79.3% in men aged > 60 years. Subjects aged > 60 years and with a duration of diabetes > 10 years were at greatest risk for all ED (OR = 10.4, 95% CI 5.8-18.5, P < 0.001) and complete ED (OR = 13.2, 95% CI 7.3-23.9, P < 0.001) when compared with the reference group (age 40-50 years with duration < 6 years). Age, duration of diabetes, HbA(1c), insulin use, neuropathy and macrovascular complications were positively associated with ED, but alcohol consumption and exercise habits were negatively associated.

CONCLUSIONS

The prevalence of complete ED was approximately six times higher than in the general population.

The effects of the overexpression of recombinant uncoupling protein 2 on proliferation, migration and plasminogen activator inhibitor 1 expression in human vascular smooth muscle cells

AIMS/HYPOTHESIS

Increased oxidative stress in vascular smooth muscle cells (VSMCs) has been implicated in the pathogenesis of accelerated atherosclerosis in patients with diabetes mellitus. Uncoupling protein 2 (UCP-2) is an important regulator of intracellular reactive oxygen species (ROS) production. We hypothesised that UCP-2 functions as an inhibitor of the atherosclerotic process in VSMCs.

METHODS

Overexpression of human UCP-2 was performed in primary cultured human VSMCs (HVSMCs) via adenovirus-mediated gene transfer. Its effects on ROS production, AP-1 activity, plasminogen activator inhibitor 1 (PAI-1) gene expression, and cellular proliferation and migration were measured in response to high glucose and angiotensin II (Ang II) concentrations, two major factors in the pathogenesis of atherosclerosis in patients with diabetes and hypertension. Mitochondrial membrane potential and NAD(P)H oxidase activity were also measured.

RESULTS

High glucose and Ang II caused transient mitochondrial membrane hyperpolarisation. They also significantly stimulated ROS production, NAD(P)H oxidase activity, mitochondrial membrane potential, AP-1 activity, PAI-1 mRNA expression, and proliferation and migration of HVSMCs. Adenovirus-mediated transfer of the UCP-2 gene reversed all of these effects.

CONCLUSIONS/INTERPRETATION

The present study demonstrates that UCP-2 can modify atherosclerotic processes in HVSMCs in response to high glucose and Ang II. Our data suggest that agents increasing UCP-2 expression in vascular cells may help prevent the development and progression of atherosclerosis in patients with diabetes and hypertension.

Comparison of early and delayed quantified indices of double-phase (99m)Tc MIBI scintimammography in the detection of primary breast cancer

PURPOSE

To compare the diagnostic accuracy and incremental diagnostic role of quantitative indices of early and delayed lesion to non-lesion ratios (L/Ns) in the detection of primary breast cancer.

MATERIAL AND METHODS

Double-phase (99m)Tc MIBI scintimammography (SMM) (early 10 min, delayed 3 h) was performed after injection of 750 MBq of (99m)Tc MIBI in 446 highly suspected breast cancer patients (malignant: 311, benign: 135). For visual analysis, five scoring methods were used, and, for quantitative analysis, early and delayed L/Ns were calculated. Receiver operating characteristic curve (ROC) analyses were performed to determine the optimal visual grade, and to calculate cut-off values of quantitative indices for differentiation of malignant and benign diseases and to investigate whether the quantitative indices could provide incremental diagnostic values in addition to visual analysis.

RESULTS

Optimal visual grades were above 4 and 5 in the detection of breast cancer. Sensitivity was 84.2% and specificity 79.3%; the area under the curve (AUC) was 0.832 (95% CI, 0.794-0.866) and standard error was 0.019. Early and delayed L/Ns of malignant breast disease were significantly higher than those of benign disease (early: 2.01 +/- 0.99 versus 1.13 +/- 0.26 (P < 0.001); delayed: 1.68 +/- 0.69 versus 1.11 +/- 0.23 (P < 0.001)). The optimal L/Ns for the detection of primary breast cancer were 1.27 for early and 1.12 for delayed imaging. When early L/N 1.27 was used as cut-off value for the detection of primary breast cancer, the sensitivity of SMM was 77.8% and specificity 85.2%. The AUC was 0.856 (95% CI, 0.820-0.888). When delayed L/N 1.12 was used, sensitivity and specificity were 81.4% and 78.5%, respectively. The AUC was 0.834 (95% CI, 0.796-0.867). The ROC comparison of early and delayed L/N showed no statistical difference in the detection of malignant breast disease (P=0.403). When the delayed L/N was added to the early one, early plus delayed quantitative analysis (E+D) showed 86.5% sensitivity and 74.8% specificity. However, the AUCs of E+D (0.854, 95% CI, 0.767-0.842) and early L/N (E) (0.856) showed no statistical difference (P=0.614). When grades 4 and 5 were used as cut-off visual grade, sensitivity and specificity were 84.2% and 79.3%, respectively. When the E was added to visual grade, visual plus early L/N (V+E) showed 89.4% sensitivity and 77% specificity. The AUC of V+E (0.867, 95% CI, 0.832 0.897) was significantly higher than that of visual analysis (V) (0.832, 95% CI, 0.794-0.866, P < 0.001). When the delayed L/N (D) was added to visual grade, visual plus delayed L/N (V+D) showed 89.4% sensitivity and 74.1% specificity. The AUCs of V+D (0.852, 95% CI, 0.816-0.884) and V revealed no statistical differences (P = 0.052).

CONCLUSION

From this study, the optimal visual grades for diagnosis of breast cancer were grades 4 and 5; the cut-off values of L/Ns were 1.27 for early and 1.12 for delayed imaging. It was also found that early L/Ns provide incremental value in addition to visual analysis. However, delayed L/N revealed no incremental value. Therefore, the delayed image should not be routinely performed for purposes of primary breast cancer detection

Absolute calibration of 60Co by using sum-peak method and an HPGe detector

The sum-peak method was applied to calibrate four 60Co sources in the range of 25-350kBq. An HPGe-based gamma-ray spectroscopy system was used, and the effects of the angular correlation and pulse pile-up were corrected, and are discussed. The correction for the angular correlation was obtained from a theoretical calculation, while the pulse pile-up effect was corrected using a new extrapolation technique based on the pile-up measurements by varying the shaping time of the amplifier. The determined radioactivities were within 2% deviation from the values reported by the supplier and the associated uncertainties were less than 2%. The observed consistency was obtained under the experimental condition of keeping the total counting rate <or=15kcps.

Factors controlling levels of CD8+ T-cell lymphocytosis associated with murine gamma-herpesvirus infection

Intranasal infection of mice with murine gamma-herpesvirus 68 (MHV-68) elicits a striking CD8+ T-cell lymphocytosis following the establishment of latency, which includes a marked increased frequency of Vbeta4+ CD8+ T cells. The Vbeta4+ CD8+ T cells do not recognize a conventional viral peptide, but are stimulated by an uncharacterized ligand expressed on latently infected, activated B cells. The selective expansion of Vbeta4+ CD8+ T cells after MHV-68 infection is observed in all mouse strains examined, although the fold-increase varies widely, ranging from less than twofold to greater than 10-fold. The factors controlling the variation are currently undefined. In the current study, CD8+ T cell activation and Vbeta4+ CD8+ T-cell frequencies were analyzed in 18 inbred strains of mice. The data show that the magnitude of the Vbeta4+ CD8+ T-cell response correlates with the degree of CD8+ T cell-activation, and that both major histocompatibility complex (MHC) and non-MHC genes contribute to the magnitude of the activation. Furthermore, the magnitude of the response does not reflect major differences in susceptibility to viral infection and/or corresponding differences in the acute response. Rather the degree of Vbeta4+ CD8+ T cell activation may be determined by differences in levels of expression of the stimulatory ligand at the peak of latency.

Vaccination against murine gamma-herpesvirus infection

The gamma-herpesviruses establish life-long latency in the host and are important human pathogens. T cells play a major role in controlling the initial acute infection and subsequently maintaining the virus in a quiescent state. However, the nature of the T-cell response to gamma-herpesvirus infection and the requirements for effective vaccination are poorly understood. The recent development of a murine gamma-herpesvirus (murine herpesvirus-68 [MHV-68]) has made it possible to analyze T-cell responses and test vaccination strategies in a small animal model. Intranasal infection with MHV-68 induces an acute infection in the lung and the subsequent establishment of long-term latency, which is associated with splenomegaly and an infectious mononucleosis-like syndrome. Here we review the T-cell response to different phases of the infection and the impact of vaccination against either lytic-cycle, or latency-associated T-cell epitopes.

Sequence variability of nine cytosolic ascorbate peroxidases in polyploid strawberry

Little is known about differential gene expression at the molecular level in polyploid plants. Here, we describe the molecular analysis of ApxSC (cytosolic ascorbate peroxidase from a polyploid strawberry) genes. Fifty-three cDNAs encoding ApxSC were isolated from a strawberry fruit cDNA library. These clones were categorized (i) into nine homologous (95 to 99%) gene groups on the basis of their nucleotide sequences and (ii) into four groups of similar (> 98%) polypeptides on the basis of their deduced amino acid sequences. Sequence variation among the gene groups was dispersed throughout the gene, while differences among the polypeptide groups were observed only at three amino acid positions (9, 63, and 233). These results imply that the ApxSC genes show co-dominant expression resulting from multiple alleles. This hypothesis is supported by genomic blots and primer extension analyses.

Antigen expression during murine gamma-herpesvirus infection

Gammaherpesviruses (gammaHV) establish a life-long latency in the host and are associated with a number of malignant human diseases. It is generally believed that T cells play a major role in controlling the initial acute infection and subsequently maintaining the virus in a quiescent state. However, the nature of the T cell response to gamma-herpesvirus infections is poorly understood. In the current report we took advantage of a mouse model of gammaHV infection (murine herpesvirus-68, MHV-68) to investigate the T cell response to different phases of the infection. Intranasal infection with MHV-68 induces an acute infection in lung epithelial cells and long-term latency in B cells. The kinetics of the CD8+ T cell response to different lytic cycle and latency-associated antigens was highly complex and distinct patterns of response could be identified. These responses were regulated by multiple factors including differences in temporal expression of the relevant antigens, differences in the presentation of antigen in different organs, and differential expression of antigen in different types of antigen presenting cells. For example, some antigens were expressed at distinct phases of the infection and in specific organs or subsets of antigen presenting cells. In addition, recent data suggest that in addition to B cells, both macrophages and dendritic cells harbor latent MHV-68 infection, adding further complexity to their role in controlling the T cell response to this infection.

Inhibition of the EGF-induced activation of phospholipase C-gamma1 by a single chain antibody fragment

Phospholipase C-gamma1(PLC-gamma1) is known to play an essential role in various cellular responses, such as proliferation and tumorigenesis, and PLC-gamma1-specific inhibitors are commonly employed to investigate the mechanism of the PLC-gamma1-mediated signaling pathway. In this study, we developed a single chain antibody fragment (scFv) as a blocker for PLC-gamma1 mediated signaling. scFv, designated F7-scFv, specifically bound to PLC-gamma1 with high affinity (K(d)=1.9x10(-8) M) in vitro. F7-scFv also bound to PLC-gamma1 in vivo and altered the distribution pattern of PLC-gamma1 from the cytoplasm to the intracellular aggregates, where F7-scFv was localized. Moreover, F7-scFv interrupted the EGF-induced translocation of PLC-gamma1 from the cytosol to the membrane ruffle and attenuated EGF-induced inositol phosphates generation and intracellular calcium mobilization. These results indicate that F7-scFv blocks EGF-induced PLC-gamma1 activation by causing sequestering of PLC-gamma1 into intracellular aggregates, and may therefore be useful in studies of the PLC-gamma1-mediated signaling pathway.

The role of surface roughness in the measurement of slipperiness

Surface roughness has been shown to have substantial effects on the slip resistance between shoe heels and floor surfaces under various types of walking environments. This paper summarizes comprehensive views of the current understanding on the roles of surface roughness on the shoe and floor surfaces in the measurement of slipperiness and discusses promising directions for future research. Various techniques and instruments for surface roughness measurements and related roughness parameters are reviewed in depth. It is suggested that a stylus-type profilometer and a laser scanning confocal microscope are the preferred instruments for surface roughness measurements in the field and laboratory, respectively. The need for developing enhanced methods for reliably characterizing the slip resistance properties is highlighted. This could be based on the principal understanding of the nature of shoe and floor interface and surface analysis techniques for characterizing both surfaces of shoe and floor. Therefore, surface roughness on both shoe and floor surfaces should be measured and combined to arrive at the final assessment of slipperiness. While controversies around the friction measurement for slipperiness assessment still remain, surface roughness measurement may provide an objective alternative to overcoming the limitations of friction measurements.

Identification of four novel RB1 germline mutations in Korean retinoblastoma patients

To elucidate RB1 germline mutations in Korean retinoblastoma patients, DNA samples from 14 children with bilateral (including three familial cases) and 19 children with unilateral retinoblastoma were analyzed. We found germline mutations in three out of 14 bilateral cases and one out of 19 unilateral cases. There were no germline mutations in the three familial cases. PCR-SSCP from each exon showed bandshifts in four patients which, upon sequencing, were shown to be K616E in exon 19 (c.1846A>G), an AA insertion in exon 7 (c.684-685insAA), R500G in exon 16 (c.1498A>G), and an A insertion in exon 23 (c.2391-2392insA), respectively. Hum Mutat 18:252, 2001.

Dendritic growth induced by BMP-7 requires Smad1 and proteasome activity

Bone morphogenetic proteins (BMPs) induce dendritic growth in cultured sympathetic neurons; however, the signaling pathways that mediate this dendrite-promoting activity have not been previously characterized. Here we report studies of the signaling events that regulate the growth of these afferent processes. We find that Smad1 is expressed in sympathetic neurons and that BMPs rapidly induce its phosphorylation and translocation from the cytoplasm to the nucleus. Furthermore, a dominant negative form of Smad1 inhibits BMP-7-induced dendritic growth, suggesting a requirement for Smad1 activation in this biological activity of BMP-7. A physical interaction between Smad1 and components involved in the proteasome-mediated degradation system was detected with a yeast two-hybrid screen, thereby prompting an examination of the effects of proteasome inhibitors on dendritic growth. Lactacystin and ALLN (N-acetyl-Leu-Leu-norleucinal) selectively blocked BMP-7-induced dendritic growth without adversely affecting either cell viability or axonal growth. Moreover, studies of transfected P19 cells suggest that the proteasome inhibitors directly block the effects of Smad1 on the transcriptional activity of the Tlx-2 promoter. These data indicate that BMP-induced dendritic growth requires Smad1 activation and involves proteasome-mediated degradation events.

Natural progress of a bone scan after cementless hydroxyapatite-coated total hip arthroplasty

To establish the natural progress pattern of postoperative bone uptake, a periprosthetic quantitative technetium-99m methylene diphosphonate scintiscan was done on 80 asymptomatic hips (62 patients) with uncomplicated cementless hydroxyapatite-coated total hip arthroplasties and 20 healthy control hips (10 subjects) without previous surgery. The patients were studied in eight groups at scheduled intervals of 1 to 48 months. There were 10 hips in each group. The measurement of bone uptake in the healthy untreated control group indicated that the uptake ratio in the proximal femur was physiologically higher in the metaphyseal area than in the diaphyseal area and the uptake ratio in the acetabulum appeared to be much higher than that of the proximal femur. In the patient group, the uptake ratio around the femoral stem area and the acetabular cup area showed a statistically significant decrease between 1 and 3 months after surgery and changed little after 3 months. Comparing the result of the patient group with that of the healthy untreated control group, the uptake ratio decreased much faster in the hydroxyapatite-coated metaphyseal zone than in the noncoated diaphyseal zone of the femoral stem area. In the acetabular cup area, the uptake ratio decreased fast, as in the hydroxyapatite-coated metaphyseal zone of the femoral stem area. Based on these clinical results, a quantitative bone scan may be a helpful diagnostic procedure for evaluating postoperative progress when used in conjunction with clinical symptoms and radiologic examinations.

Alterations in p53 and E2F-1 function common to immortalized chicken embryo fibroblasts

A number of non-virally and non-chemically immortalized chicken embryo fibroblast (CEF) cells have been established recently in continuous cell culture. All immortal CEF cells tested showed common genetic alterations in the expression patterns of p53 and E2F-1 mRNA and protein which were down- and up-regulated, respectively. The biological effects of differentially regulated p53 and E2F-1 were determined by reporter gene transcriptional activity assays, DNA binding assays, and Northern blot analysis of the expression patterns of down-stream genes. In addition, expression of most of the cyclin genes was up-regulated in immortal CEF cells, which may be associated with the rapid cell division rates and serum-independent growth patterns seen in immortal CEF cells. The telomeric lengths and chromosome integrity were maintained in all immortal CEF cell lines without detectable telomerase activity. Although the functional inactivations of the p53 and Rb regulatory pathways are known to be common events for cellular immortalization, the genetic changes leading to alteration of p53 and E2F-1 function through transcriptional and post-transcriptional regulation seem to be unique in immortal CEF cells.

Increased mitochondrial-encoded gene transcription in immortal DF-1 cells

We have established, in continuous cell culture, a spontaneously immortalized chicken embryo fibroblast (CEF) cell line (DF-1) as well as several other immortal CEF cell lines. The immortal DF-1 cells divided more rapidly than primary and other immortal CEF cells. To identify the genes involved in rapidly dividing DF-1 cells, we have used differential display RT-PCR. Of the numerous genes analyzed, three mitochondrial-encoded genes (ATPase 8/6, 16S rRNA, and cytochrome b) were shown to express at higher levels in DF-1 cells compared to primary and other immortal CEF cells. The inhibition of mitochondrial translation by treatment with chloramphenicol markedly decreased ATP production and cell proliferation in DF-1 cells, while not affecting growth in either primary or other immortal CEF cells. This result suggests a correlation between rapid cell proliferation and the increased mitochondrial respiratory functions. We also determined that the increased transcription of mitochondrial-encoded genes in DF-1 cells is due to increased de novo transcript synthesis as shown by mitochondrial run-on assays, and not the result of either increased mitochondrial biogenesis or mitochondrial transcript half-lives. Together, the present studies suggest that the transcriptional activation of mitochondrial-encoded genes and the elevated respiratory function should be one of the characteristics of rapidly dividing immortal cells.

Co2(CO)8-mediated endo mode cyclization of epoxy-alcohol: synthesis of 2-ethynyl-3-hydroxy-2-methyltetrahydropyran and 2-ethynyl-3-hydroxy-3-methyltetrahydropyran derivatives

Successive treatment of 4,5-epoxy-5-methyl-7-trimethylsilyl-6-heptyne-1-ol with Co2(CO)8 at 0 degrees C and a catalytic amount of BF3 x OEt2 at -78 degrees C gave the tetrahydropyran derivatives with the cobalt-complexed moiety. Similarly 4,5-epoxy-4-methyl-7-trimethylsilyl-6-heptyne-1-ol underwent ring closure under the above conditions to provide the corresponding tetrahydropyran derivatives. The preferential endo mode cyclization over the exo one was observed in these experiments.

Molecular characterization of cDNA clones for ADP-glucose pyrophosphorylase from Citrus

Two cDNA clones encoding ADP-glucose pyrophosphorylases have been isolated from fruit and leaf cDNA libraries of Citrus (Citrus unshiu Mac. cv. Miyagawa) in which one was designated as agpS for the small subunit and the other as agpL for the large subunit. Both cDNAs have uninterrupted open reading frames deriving 57-58 kDa polypeptides. The deduced amino acid sequence of agpS has a unique feature. That is, it lacks a cysteine residue (Cys-12) which is usually conserved in all other dicot enzymes. This is the first report of agpS lacking Cys-12 among dicot small subunits. The expression pattern of both subunits showed a different profile in which leaves synthesized both agpS and agpL more vigorously than those of fruits. During leaf development, the transcripts of agpS and agpL showed a higher expression level at younger stages. During fruit development, the expression level of both subunits was observed to be highest in the mini-green stage, but it decreased in the small green stage and it increased again towards the maturing stage. These results suggest that both subunits may play an important role in the regulation of Citrus fruit and leaf development.

Total syntheses of tumor-related antigens N3: probing the feasibility limits of the glycal assembly method

The total syntheses of two octasaccharide antigens isolated from human milk, 1 and 2, and their corresponding allyl glycosides, 3 and 4, have been achieved by utilizing the glycal method. Convergent assembly of the core hexasaccharides and concurrent introduction of two alpha-L-fucosyl moieties at the late stage of the syntheses provided these complex carbohydrates in a concise manner. With synthetic material obtained, biological evaluations of these antigens as potential gastrointestinal cancer immunotherapeutic agents have been initiated.

Characteristics of bursal T lymphocytes induced by infectious bursal disease virus

Infectious bursal disease virus (IBDV) is an avian lymphotropic virus that causes immunosuppression. When specific-pathogen-free chickens were exposed to a pathogenic strain of IBDV (IM), the virus rapidly destroyed B cells in the bursa of Fabricius. Extensive viral replication was accompanied by an infiltration of T cells in the bursa. We studied the characteristics of intrabursal T lymphocytes in IBDV-infected chickens and examined whether T cells were involved in virus clearance. Flow cytometric analysis of single-cell suspensions of the bursal tissue revealed that T cells were first detectable at 4 days postinoculation (p.i.). At 7 days p.i., 65% of bursal cells were T cells and 7% were B cells. After virus infection, the numbers of bursal T cells expressing activation markers Ia and CD25 were significantly increased (P<0.03). In addition, IBDV-induced bursal T cells produced elevated levels of interleukin-6-like factor and nitric oxide-inducing factor in vitro. Spleen and bursal cells of IBDV-infected chickens had upregulated gamma interferon gene expression in comparison with virus-free chickens. In IBDV-infected chickens, bursal T cells proliferated in vitro upon stimulation with purified IBDV in a dose-dependent manner (P<0.02), whereas virus-specific T-cell expansion was not detected in the spleen. Cyclosporin A treatment, which reduced the number of circulating T cells and compromised T-cell mitogenesis, increased viral burden in the bursae of IBDV-infected chickens. The results suggest that intrabursal T cells and T-cell-mediated responses may be important in viral clearance and promoting recovery from infection.

Enhanced detection of left atrial spontaneous echo contrast by transthoracic harmonic imaging in mitral stenosis

BACKGROUND

Spontaneous echo contrast (SEC) of the left atrium is associated with increased risk of thromboembolism in patients with mitral stenosis (MS). The determination of the presence and severity of left atrial (LA) SEC is of prognostic importance in these patients. Harmonic imaging (HI), a novel echocardiographic technique that differs from conventional fundamental imaging (FI) in that it involves transmitting ultrasound at one frequency and receiving at twice the transmitted frequency, produces better endocardial border definition and myocardial opacification. However, there are no data about its value for the detection of LA SEC. The purpose of this study was to investigate the utility of transthoracic noncontrast tissue HI in the detection of LA SEC in patients with MS.

METHODS

Seventy-four consecutive patients with MS (49 women, mean age 51 years) underwent standard transthoracic echocardiography (TTE) in both HI and FI modes and transesophageal echocardiography (TEE) to determine the presence and severity of LA SEC. Left atrial SEC was graded by TEE as either mild (only seen at high gain) or severe (visible in the entire left atrium at normal gain control of the equipment). The control group comprised 30 patients randomly selected from patients who did not have LA SEC at the TEE examination.

RESULTS

Atrial fibrillation was found in 46 patients (62.2%). The mean mitral valve area and mean mitral gradient were 1.0+/-0.3 cm(2) and 8.2+/-4.1 mm Hg, respectively. Nine patients (12.2%) had episodes of systemic embolism; 8 had stroke, and 1 had peripheral embolism. Left atrial thrombus was found in 11 patients (14.9%) by TEE. Left atrial SEC was present in all but one patient by TEE (mild in 35 patients, severe in 38). Fundamental imaging with TTE, however, revealed LA SEC in only 5 (6.8%) of the 73 patients. In contrast, with HI, LA SEC could be detected in 63 (86.3%) patients. In the detection of severe LA SEC, the sensitivities of FI and HI were 13.2% (5/38) and 100% (38/38), respectively. Left atrial SEC was not observed in control subjects by either FI or HI.

CONCLUSIONS

Transthoracic HI significantly enhances the detection of LA SEC in patients with MS.

Affinity maturation of natural antibody using a chain shuffling technique and the expression of recombinant antibodies in Escherichia coli

The affinity of natural antibody (Ka = 8 x 10(6) M(-1)) recognizing preS1 of hepatitis B virus (HBV) was improved by replacing the heavy (H) chain gene with repertoires of VH genes, obtained from two nonimmunized donors. Two separate clones, 1C2 and 1E4, showed affinities of 2.3 x 10(7) and 5.2 x 10(7) M(-1), which were increased by factors of 2.8 and 6.5, respectively, compared to the parental clone. Recombinant scFvs (rscFvs) were expressed as fusion protein with minor coat protein, pIII, and secreted into medium after 3 h of induction with 1 mM IPTG. The expression level of functional rscFv capable of binding to preS1 reached a peak after 6-10 h (1C2) and 8-10 h (1E4) of IPTG induction, and afterwards decreased gradually. In order to achieve the overexpression of rscFv in E. coli, gene encoding scFv of 1C2 or 1E4 was inserted into pRSET vector. RscFvs were overexpressed as cytoplasmic inclusion bodies in E. coli BL 21 strain, which were denatured and carefully refolded using a continuous dialysis system. The purified recombinant fragments were pure when analyzed by SDS-PAGE and had the predicted size of 34 kDa. Clone 1E4 used the heavy chain gene belonging to family VII and subgroup III. Chain shuffling offers an alternative to random point mutation for affinity maturation of human antibody in vitro.

Germline mutations of the dpc4 gene in Korean juvenile polyposis patients

Juvenile polyposis is an uncommon condition characterized by the development of multiple (usually more than 5) juvenile polyps in the gastrointestinal tract, especially in the colon. This disease usually occurs during childhood, and is inherited in an autosomal dominant fashion. It has been suggested that the dpc4 (deleted in pancreatic carcinoma, locus 4) gene, which is located on chromosome 18q21.1, might cause juvenile polyposis. The dpc4 (smad4) gene is a candidate tumor-suppressor gene and may play a role in the TGF-beta-signaling pathway. To confirm the idea that alterations of the dpc4 gene may result in juvenile polyposis, we screened 5 Korean juvenile-polyposis patients by PCR-SSCP (single-strand conformation polymorphism) analysis and bi-directional sequencing. There were germline mutations of the dpc4 gene in 3 out of the 5 patients: 2 had a genetic alteration in exon 9 and the third had a mutation in exon 8. These germline mutations occurred in the C-terminus of the dpc4 gene, similar to most published mutations. One patient exhibited a non-sense mutation (codon 388), which changed a glutamine codon (CAG) to a stop codon (TAG). The second patient harbored a mis-sense mutation (codon 390), causing a non-conservative amino-acid change <glutamate (GAA) to lysine (AAA)>. The third patient had a mis-sense mutation in exon 8 (codon 361), which altered an arginine codon (CGC) into a histidine codon (CAC).

Nasal cycle in patients with septal deviation: evaluation by acoustic rhinometry

The nasal cycle in patients with septal deviation was studied by acoustic rhinometric techniques. This study included 24 patients with anteriorly located septal deviations (mean age = 23.5), and 26 normal controls (mean age = 24.7). Data of MCA (minimum cross-sectional area) and NV (nasal volume), collected in 20-minute intervals, were plotted for each subject during 8 hours. Twenty of 24 patients (83%) with septal deviation and 20 of 26 normal subjects (77%) showed at least one complete cycle. Duration of the nasal cycle, which ranged from 100 minutes to 400 minutes, had no statistical difference between the septal deviation group (mean duration of 216 minutes) and the normal control group (mean duration of 227 minutes). The degrees of variation of MCA and NV, defined as Degree of Variation of MCA (%) = 100 (MCAmax - MCAmin)/MCAmax, Degree of Variation of NV (%) = 100 (NVmax - NVmin)/NVmax, which represent the percent change of MCA and NV throughout the study, showed no difference between the wide side and the narrow side, or between the septal deviation group and the normal control group. These findings suggest that the nasal cycle is relatively independent of peripheral anatomic factors for its generation. However, the amplitude of changes of MCA was greater in the wide side, and the sum of both MCAs tended to fluctuate in accordance with the fluctuation of MCA of the wide side. Thus, the nasal cycle seemed to be affected by septal deviation.