Reflective second harmonic generation near resonance in the epitaxial Al-doped ZnO thin film

The second harmonic (SH) generation from the highly epitaxial Al-doped ZnO film on sapphire was measured, using the femtosecond Ti:Sapphire laser at the near-resonant SH wavelength, in reflection geometry to avoid the sapphire's contribution in the conventional Maker fringes technique. By investigating SH intensities as a function of the azimuthal angle along the film's normal, we found that the sapphire substrate had a negligible contribution to the reflective SH signal and the film had a pure and well-aligned c-domain. We also developed a new method to calculate the component's ratios of the nonlinear susceptibility tensor by analyzing the polarization diagrams of SH intensities under the incidence with two different angles. The ratios indicate that Kleinman's symmetry is broken due to the absorption at SH wavelength and the dominant component of the nonlinear susceptibility tensor is d(33). Calibration using the Z-cut quartz shows a possible overestimate of the nonlinear response by Maker fringes technique.

A preliminary report of brain edema in patients with uremia at first hemodialysis: evaluation by diffusion-weighted MR imaging

BACKGROUND AND PURPOSE

The dynamics of brain-water content associated with hemodialysis in patients with severe azotemia remains obscure. To investigate whether either interstitial or cytotoxic edema is responsible for dialysis disequilibrium syndrome (DDS), we used diffusion-weighted MR imaging (DWI) to measure the apparent diffusion coefficient (ADC), which is sensitive for detecting tissue water dynamics.

METHODS

Eight consecutive patients with end stage renal disease (ESRD) and blood urea nitrogen level of more than 100 mg/dL (160.9 +/- 53.1 mg/dL) were recruited. Conventional MR images, DWI, and clinical manifestations were obtained before and after the 1st hemodialysis. The ADC values were determined for regions of normal-appearing gray and white matter and for regions of hyperintensity of white matter on T2-weighted MR imaging.

RESULTS

Foci of bright areas of white matter were found in all patients on T2-weighted images. The ADC values of the patients with ESRD, in white matter and gray matter before and after hemodialysis, were greater than those of the healthy controls (P < .005). Regarding the impact of hemodialysis, the ADC of frontal lobe white matter increased significantly after hemodialysis (1.09 +/- 0.11 versus 1.03 +/- 0.11, P = .036). We did not find the specific area of brain edema reported in posterior leukoencephalopathy and the osmotic demyelination syndrome.

CONCLUSIONS

These results suggest that severe azotemia in end stage renal disease leads to interstitial brain edema reflected as increased ADC, and the further increased ADC reflects that edema associated with 1st hemodialysis is interstitial rather than cytotoxic in nature.

Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation

Portal hyperperfusion in a small-size liver graft is one cause of posttransplant graft dysfunction. We retrospectively analyzed the potential risk factors predicting the development of portal hyperperfusion in 43 adult living donor liver transplantation recipients. The following were evaluated: age, body weight, native liver disease, spleen size, graft size, graft-to-recipient weight ratio (GRWR), total portal flow, recipient portal venous flow per 100 g graft weight (RPVF), graft-to-recipient spleen size ratio (GRSSR) and portosystemic shunting. Spleen size was directly proportional to the total portal flow (p = 0.001) and RPVF (p = 0.014). Graft hyperperfusion (RPVF flow > 250 mL/min/100 g graft) was seen in eight recipients. If the GRSSR was < 0.6, 5 of 11 cases were found to have graft hyperperfusion (p = 0.017). The presence of portosystemic shunting was significant in decreasing excessive RPVF (p = 0.059). A decrease in portal flow in the hyperperfused grafts was achieved by intraoperative splenic artery ligation or splenectomy. Spleen size is a major factor contributing to portal flow after transplant. The GRSSR is associated with posttransplant graft hyperperfusion at a ratio of < 0.6.

Ceramide in apoptotic signaling and anticancer therapy

Ceramide, a product of sphingolipid metabolism, is generated in response to various stress stimuli, such as tumor necrosis factor-alpha, CD95/Fas, chemotherapeutic agents, and irradiation. Ceramide may modulate the biochemical and cellular processes that lead to apoptosis. However, the mechanisms by which ceramide regulates apoptotic events are not fully defined. It is believed that the biological effect of ceramide depends on its concentration, the activation or differentiation status of the cell, and the time frame of action. Here, we discuss the metabolism and cell apoptotic signaling of ceramide. The involvement of protein kinases (i.e. PI3K/Akt and GSK-3beta) and protein phosphatases (i.e. PP1 and PP2A), Bcl-2 family proteins, mitochondrial damage, and caspase cascade activation are demonstrated. Further, ceramide and its derivatives have recently been incorporated into strategies for anticancer therapies. An understanding of the apoptotic signaling pathways mediated by ceramide may shed light on its potential for therapeutic intervention.

Posterior epidural migration of a sequestrated lumbar disk fragment: MR imaging findings

We present a 75-year-old man who, for 2 weeks, had progressive pain in both of his thighs when standing straight. MR imaging showed a sequestrated disk fragment, which had a signal intensity similar to that of a herniated disk with a rim enhancement in the posterior epidural space and a ruptured outermost annulus of the intervertebral disk at L2-3. Awareness of these MR imaging findings can help in the diagnosis of posterior epidural disk migration.

The expression of genes related to adipocyte differentiation in pigs1

The purpose of this study was to detect differential expression of genes related to adipocyte differentiation in pigs by suppression subtractive hybridization. Adipocytes and stromal vascular cells (a fraction containing preadipocytes) from pig adipose tissue were isolated for mRNA extraction. The cDNA from preadipocytes was subtracted from the cDNA from adipocytes. The subtracted gene fragments were cloned into pGEM-T Easy TA cloning vector. We selected 384 clones for gene sequence determination and for further analysis. These genes were subjected to a differential screening procedure to confirm the differential expression of genes between the 2 cell types. We found that at least 36 genes were highly expressed in the adipocytes compared with preadipocytes. Among these, 6 genes including 2 novel genes with the greatest differences were selected and confirmed by Northern analysis. We found that angiotensin I-converting enzyme (ACE), ataxia-telangiectasia mutated protein (ATM), calpain 1, and stearoyl coenzyme A desaturase 1 (SCD1) were highly expressed in adipocytes compared with preadipocytes (P < 0.05). The relative mRNA abundance of ACE, ATM, calpain 1, SCD1, and 2 novel genes discovered in the current study was increased at the later stages of adipocyte differentiation (P < 0.05). The results confirmed that the genes involved in lipid metabolism and adipocyte differentiation were highly expressed in porcine adipocytes. However, further investigation is needed to demonstrate specific functions of the novel genes discovered in the current study.

Zidampidine, an aryl phosphate derivative of AZT: in vivo pharmacokinetics, metabolism, toxicity, and anti-viral efficacy against hemorrhagic fever caused by Lassa virus

The pharmacokinetics, metabolism, and toxicity of Zidampidine, an aryl phosphate derivative of AZT, 3'-azidothymidine-5'-[p-bromophenyl methoxyalaninyl phosphate] were investigated in CD-1 mice. Following iv injection, Zidampidine was rapidly converted to its metabolites Ala-AZT-MP and AZT. Zidampidine was not toxic to mice at doses up to 250mg/kg. We next examined the therapeutic effect of Zidampidine in CBA mice challenged with intracerebral injections of the Josiah strain of Lassa virus. Mice were treated either with vehicle or non-toxic doses of Zidampidine administered intraperitoneally 24h prior, 1h prior, and 24, 48, 72, and 96h after virus inoculation. The probability of survival following the Lassa challenge was significantly improved for Zidampidine-treated mice (Kaplan Meier, Log-Rank p value<0.0001). This pilot study provides the basis for future preclinical evaluation of Zidampidine and its potential as a new agent for the treatment of viral hemorrhagic fevers caused by Lassa virus.

The Significance of Hepatic Vein Outflow Volume in Hepatic Outflow Insufficiency of Living Right Liver Graft Evaluated by Doppler Ultrasound

The color Doppler ultrasound has been used to evaluate hepatic vein (HV) outflow insufficiency based on flow velocity and waveforms. In our experience, some cases with flat waveforms are clinically asymptomatic. The parameters of HV flow velocity and waveforms are not always correlated with clinical problems. So, we proposed that total HV flow volume (HVFV) may be a more reliable index. From August 2001 to July 2003, 31 cases among 48 adult-to-adult living related transplants of a right liver graft had one HV anastomosis. HV velocity, waveforms, and HVFV were compared both before and after transplantation. We set the minimal HVFV ratio at 80% based on the original HVFV before graft retrieval. There was no significant difference in HVFV before liver graft retrieval between the 2 groups, but there was a significant change after transplantation. There were no cases of HV insufficiency among group A patients (>80%), whose HVFV ranged from 397 to 1181 mL/min with ratios from 75% to 180% (mean 115%). In group B, there were 4 complicated cases with prolonged severe ascites (<80%) with HVFV ratios from 56% to 76% (mean 66%). Fisher exact test showed a great significance (P < .001). Thus the preliminary criteria of 80% minimal HVFV ratio allows detection of HV insufficiency for further interventional management.

Dyspeptic symptoms and water load test in patients with functional dyspepsia and reflux disease

OBJECTIVE

Hypersensitivity to gastric distension has been reported in functional dyspepsia (FD). The aim of this study was to assess the perception to gastric distension and its relationship to specific symptoms using the water load test (WLT) in FD and gastroesophageal reflux disease (GERD).

MATERIAL AND METHODS

A 5-min WLT was used to evaluate sensitivity of gastric distension in 47 FD and 61 GERD subjects, and 49 healthy controls (HC). A visual analogue scale (VAS) measuring symptom severity was obtained from all subjects and its relationship with the maximal ingested volume was determined. The maximal ingested volume was registered and the subjective symptoms were assessed at baseline and 30 min after the WLT.

RESULTS

The maximal ingested volume by HC was 597 +/- 33 ml, which was statistically greater than that of FD (422 +/- 22 ml, p < 0.001) and GERD (504 +/- 23 ml, p < 0.02) subjects. The maximal ingested volume did not differ significantly between FD and GERD. The maximal ingested volume correlated well with nausea (r = -0.49, p < 0.01) and fullness (r = -0.33, p < 0.05) in FD. Male subjects ingested more water than females in the HC (p < 0.01) and GERD groups (p < 0.05), but not in FD (p = NS).

CONCLUSIONS

Both FD and GERD subjects have altered perception to gastric fullness induced by the WLT compared to healthy controls. Good correlations have been observed between the WLT and dyspeptic symptoms such as early satiety and postprandial fullness, but not in GERD.

Clinical events occurrence and the changes of quality of life in chronic haemodialysis patients with dry weight determined by echocardiographic method

The maintenance of circulating blood volume within an optimal range is necessary for haemodialysis patients to avoid circulating complications, including over-hydration and dehydration. Inferior vena cava diameter (IVCD) estimation is a non-invasive method to obtain a well correlation with the intravascular fluid status, and it may get a reliable ideal dry weight (DW) for chronic haemodialysis patients. We try to analysis the life quality changes and circulating complication in chronic haemodialysis patients who adjust DW with this tool in comparing with the traditional method. A total of 100 chronic haemodialysis patients, ranging from 26 to 77 years old, were involved in this study. They are randomly divided into study (n = 50) and control group (n= 50). All of them received the IVCD estimation by echocardiography every month for 3 months. The patients in the study group adjusted the DW with the IVCD estimated by echocardiographic method, however, patients in the control group with the traditional method. The quality of life (QOL) was evaluated with the short form 36 questionnaire (SF-36) in the beginning and the end of the study. The scores of physical functioning (PF), role limitation-physical (RP), general health (GH) and role limitation-emotional (RE) have much improvement in the patients of the study group than those in the control group. Besides, the occurrence of clinical events due to circulating complications during the study period showed significant reduction in the extents of hypotension, gastrointestinal upset, discontinuation of haemodialysis, muscular cramps, tinnitus, headache and chest discomforts with electrocardiographic changes; and these effects, especially, are significant in the patients with over-dehydrated status, which with the IVCD < 8 mm/m2 detected by echocardiographic method. The study demonstrated that ideal DW estimated by echocardiographic method not only improved the QOL but also reduced the circulating complications during haemodialysis for chronic haemodialysis patients.

GISH, AFLP and PCR-RFLP analysis of an intergeneric somatic hybrid combining Goutou sour orange and Poncirus trifoliata

Intergeneric somatic hybrids combining Goutou sour orange (Citrus aurantium L.) with trifoliate orange Poncirus trifoliata (L.) Raf] were produced by electrofusion and their genetic inheritance analyzed by amplified fragment length polymorphism (AFLP), genomic in situ hybridization (GISH), and PCR-restriction fragment length polymorphism (PCR-RFLP). Sixteen mini-calluses were obtained after 20 days of culture; they all developed into embryoids on EME500 medium. Following several subcultures on shoot induction medium for a total culture period of 6 months, shoots regenerated. The plants grew vigorously with a well-developed root system and exhibited the trifoliate leaf character of P. trifoliata. Ploidy analysis verified that all of the regenerates were tetraploids (2 n=4 x=36) as expected. GISH analysis confirmed that 18 chromosomes came from trifoliate orange and the remaining 18 from Goutou sour orange, as with most symmetric somatic hybrid plants; moreover, chromosome translocations were also observed in one plant. AFLP analysis of 16 regenerates and their fusion parents indicated that all of the somatic hybrids except one were genetically uniform. Analysis of the somatic hybrid cytoplasmic genomes with universal primers revealed that their chloroplast DNA (cpDNA) banding patterns were identical to those of the mesophyll parent trifoliate orange, while their mitochondria (mt) genomes were of the callus parent sour orange. The potential of GISH in Citrus somatic hybrid analysis is discussed.

Hepatic venous stenosis in partial liver graft transplantation detected by color Doppler ultrasound before and after radiological interventional management

Hepatic outflow insufficiency remains one of the major complications causing postoperative graft failure especially among partial liver graft transplantations (PLT) including living donor liver transplantation (LDLT), reduced size liver transplantation (RLT), and split liver transplantation (SLT). These procedures are different from the whole liver graft transplantations (OLT), which include multiple vascular anastomoses. Color Doppler ultrasound (CDUS) was used to evaluate the hepatic venous outflow from grafts before and after radiological interventional management and to document treatment effects. From June 1994 to March 2003, our 136 cases of PLTs included 131 LDLTs, two RLTs, and three SLTs. Seven cases (six children and one adult) showed postoperative hepatic vein outflow obstruction and persistent massive ascites, as detected by color Doppler ultrasound (CDUS) and confirmed by interventional angiography. The CDUS showed a monophasic flat waveform with a relatively low hepatic vein average peak velocity (Va) in all cases (mean 11 cm/s). Successful interventional procedures included balloon dilatation in three cases and metallic stent replacement in four cases. CDUS was used with guidance during the procedure to confirm restoration of normal hepatic vein flow with a multiphasic waveform and an objective increase of average flow velocity (high to average 66 cm/s). Ascites disappeared dramatically after the procedure. In conclusion CDUS is the prime modality to diagnose and document a treatment response.

The significance of transarterial embolization for advanced hepatocellular carcinoma in liver transplantation

INTRODUCTION

Transarterial embolization (TAE) is the treatment of choice for advanced HCC to control or even induce tumor shrinkage. The aim of this study was to evaluate the effect of pretransplantation TAE for treatment of advanced HCC.

MATERIAL AND METHODS

From 1996 to 2002, we studied 12 cirrhotic patients with HCC, including six who met and six who exceeded the Milan criteria. All patients had sufficient hepatic function to undergo TAE. Liver transplantations were performed subsequently and they were followed prospectively for a median of 22 months (range = 12 to 53 months).

RESULTS

The explanted livers from the 12 patients who had undergone TAE were noted to have extensive tumor necrosis. The pathological specimens at LT showed downstaging of the HCC, which allowed those six patients to meet the Milan criteria. The overall 1- and 2-year survival rates were 92% and 73%, respectively. The overall 1- and 2-year disease-free survival rates were 92% and 73%, respectively. One death unrelated to liver disease at 2 years after LT was noted in the downgraded group. One patient of the initially eligible group developed lung metastasis at 6 months and died at 12 months after LT.

CONCLUSION

TAE is effective to downstage advanced HCC and reduce the dropout rate on the LT waiting list. Pre-LT TAE may be considered as a better therapeutic strategy for patients with advanced HCC.

Association between urokinase gene 3'-UTR T/C polymorphism and Chinese patients with rheumatoid arthritis in Taiwan

OBJECTIVES

The purpose of this study was to investigate whether the urokinase gene 3'-UTR C/T polymorphism is a marker of susceptibility to or severity of rheumatoid arthritis (RA) in Chinese patients.

METHODS

A total of 145 RA patients and 134 healthy control subjects were enrolled in this study. We identified the C/T polymorphism of the urokinase gene, which is mapped on the 3'-untranslated region (3'-UTR) on chromosome 10 by polymerase chain reaction (PCR).

RESULTS

There were significant differences in the distribution of the urokinase gene 3'-UTR C/T polymorphism frequency between RA patients and subjects in the control group. However, we did not detect an, association between the urokinase gene 3'-UTR C/T polymorphism and rheumatoid factor (RF), extraarticular involvement or bone erosion in RA patients.

CONCLUSION

The urokinase gene 3'-UTR "T" allele was associated with RA in Chinese patients in Taiwan.

Transfer function analysis of heart rate variability in response to water intake: correlation with gastric myoelectrical activity

We utilized transfer function analysis of heart rate variability (HRV) and respiration to investigate the effect of water intake on gastric myoelectrical activity and its relationship to vagal activity. The electrogastrography (EGG) and HRV were recorded simultaneously before and after drinking 500 ml of water in 10 healthy subjects. We observed good linearity between lung volumes and HRV signals at a ventilatory rate between 0.2 and 0.4 Hz before and after water intake. The EGG power of 3 cycles/min increased remarkably after the water intake. We found that there was a significant increase in the magnitude of the respiration-HRV transfer function after water intake (P < 0.05). The EGG 3 cycles/min power was positively correlated with the transfer magnitude throughout the study (r = 0.54, P = 0.01). These results confirm that transfer function analysis of HRV sensitively identifies subtle changes in the respiratory sinus arrhythmia that occurs with water intake. The present findings suggest that transfer function analysis of HRV and respiration after water intake can be used to evaluate vagal nervous activity in the human gut.

Tuberculosis in patients with end-stage renal disease

OBJECTIVE

To elucidate the clinical manifestations and risk factors of the mortality rate in uraemic patients with tuberculosis (TB) infection.

DESIGN

We retrospectively analysed 62 patients with uraemia and active tuberculosis who were admitted to our hospital from 1990 through 2000. The patients were followed up for 2 years after discharge or until death.

RESULTS

There were 43 men and 19 women, with a mean age of 63 +/- 13 years. Extra-pulmonary TB was noted in 51.6%. The peritoneum and pleura were the two most common organs involved. Fever of unknown origin was the most common manifestation (77.4%). The corrected serum Ca2+ level of the patients was >10.5 mg/dl in 46.8%. C-reactive protein >6 mg/dl and leukocytosis (white blood cell count >10,000/mm3) at presentation were noted in more than half of the patients. A reversed serum albumin/globulin ratio and leukocytosis were found to be associated with mortality rate.

CONCLUSION

More than half of the TB infections in patients with end-stage renal disease presented with extra-pulmonary involvement. Fever of unknown origin, reversed serum albumin/globulin ratio, and unexplained hypercalcaemia in maintenance dialysis patients suggested the possibility of tuberculosis.

The detection of small simulated field defects using multifocal VEPs

INTRODUCTION

The multifocal visual-evoked potential (mfVEP) has been widely investigated in the study of diseases of the visual system. However, the sensitivity of the mfVEP in objective detection of field defects has not been determined. This study investigates the variation of the mfVEP responses whilst simulating field defects by using different sizes of mask on the stimulus pattern.

METHODS

Simulated field defects of four different sizes (2, 3, 5, and 7 degrees) at two different eccentricities (10 and 16 degrees) were generated on a standard mfVEP dartboard stimulus using opaque masks. These masks were placed at the centre of each dartboard sector and the modified stimuli were used to elicit mfVEPs from 10 normal subjects. The response densities and latencies of N1, P1 of the mfVEP were compared, without and with small simulated field defects.

RESULTS

The minimum size of simulated field defect causing significant response density reduction in P1 and N1 was 5 degrees at both retinal eccentricities. N1 showed similar reduction in response density at both retinal eccentricities, but P1 showed larger reduction at the 10-degree location than at the 16-degree location. There was no change in latencies with simulated field defect at either location.

CONCLUSIONS

The mfVEP is only sensitive to a simulated field defect equal to or larger than 5 degrees in diameter, and mfVEP has greater sensitivity at 10-degree eccentricity than at 16-degree eccentricity.

Sialyltransferase family members and cervix squamous cell carcinoma

Sialic acids including a number of their derivatives are ubiquitous at the terminal positions of the oligosaccharides of glycoproteins. The transfer of sialic acids from cystidine-5-monophospho-N-acetylneuraminic acid (CMP-NeuAc) to the terminal position of the carbohydrate group of glycoproteins and glycolipids is catalyzed by a family of sialyltransferases (STs). There is a large body of evidence to suggest that tumor cells have altered surface properties from their normal counterparts, and that these changes are partially due to altered sialo-glycoconjugates expressed on the plasma membrane and that altered sialylation (change in glycoprotein expression), which occurs during certain pathological processes, such as oncogenic transformation, tumor metastases, and invasion, is associated with enhanced ST activity. In this report we attempt to review the important findings in studing sialyltransferases of cervix squamous cell carcinoma.

E-cadherin expression is silenced by DNA methylation in cervical cancer cell lines and tumours

A previous study showed E-cadherin expression was lost in some cervical cancer cell lines and tumours. This study was designed to clarify the significance of DNA methylation in silencing E-cadherin expression. We examined promoter methylation of E-cadherin in five cervical cancer cell lines and 20 cervical cancer tissues using methylation-specific PCR (MSP) and bisulphite DNA sequencing. The correlation of E-cadherin methylation and expression together with methyltransferase (DNMT1) were further studied. We found that hypermethylation of E-cadherin was involved in five cervical cancer cell lines and 40% (8/20) of cervical cancer tissues. E-cadherin protein was lost in 6/8 (75%) samples and 3/5 (60%) cell lines with promoter methylation. E-cadherin methylation was significantly correlated with increased DNMT1. Using an antisense DNMT1 oligo to transfect into SiHa HeLa C33A cell line, E-cadherin protein was re-expressed. We concluded that loss of E-cadherin expression was in part correlated with DNA methylation and DNMT1 expression in cervical cancer.

Aging and neural control of the GI tract: IV. Clinical and physiological aspects of gastrointestinal motility and aging

The gastrointestinal motility changes that occur as a function of age are reviewed herein. Careful attention must be given in any review of aging phenomena to exclude, or at least be cognizant of, the many comorbid conditions that can alter physiological functioning in older adults. The dramatic increase in life expectancy over the past 10-15 years demands that clinicians be aware of the various physiological and clinically relevant changes that occur with age. Gastrointestinal motility changes associated with age are relatively subtle, and in many instances only conflicting data exist. As the older adult population increases, and as the control of disease is improved, much more work needs to be done to understand the true effects of aging on gastrointestinal functioning.