Heterogeneous radio-over-fiber passive access network architecture to mitigate Rayleigh backscattering interferometric beat noise

We propose and experimentally demonstrate a hybrid radio-over-fiber (ROF) wavelength division multiplexed and time division multiplexed passive optical network (WDM-TDM PON) architecture to mitigate Rayleigh backscattering (RB) interferometric beat noises. Here, only a single wavelength is needed at the central office (CO) to generate the downstream baseband data for optical wired application and optical millimeter-wave (mm-wave) signal for wireless application. The upstream signal is produced by remodulating the downstream signal. No optical filter is required at the optical network unit/remote antenna unit (ONU/RAU) to separate the optical wired and optical mm-wave signals. In the proposed network, 10 Gb/s differential phase shift keying (DPSK) signal is used for the downstream optical wired application and 2.5 Gb/s on-off keying (OOK) signal on 20 GHz carrier is used for the optical mm-wave signal. In each ONU, a reflective optical semiconductor amplifier (RSOA) is used to remodulate and produce a 2.5 Gb/s OOK format for upstream traffic. As the back-refection produced by the downstream DPSK signal and the upstream OOK signal is traveling in different fiber path, RB noise at the CO can be completely mitigated.

Mitigation of Rayleigh backscattering in 10-Gb/s downstream and 2.5-Gb/s upstream DWDM 100-km long-reach PONs

Long-reach passive optical network (LR-PON) is considered as a promising technology towards higher capacity and extended coverage optical system. We propose and demonstrate a LR-PON with the capability of Rayleigh backscattering (RB) noise mitigation. By using the upstream signal wavelength-transition generated by a dual-parallel Mach-Zehnder modulator (DP-MZM) based colorless optical networking unit (ONU), the spectral overlap among the upstream signal and the RB noises can be minimized. Hence, due to the achievement of effective RB mitigation, a 100 km LR-PON with a high split-ratio of 512 is demonstrated using 10 Gb/s non-return-to-zero (NRZ) downstream and 2.5 Gb/s NRZ upstream signals. Detail analysis of the wavelength-transition generation is presented.

40-Gb/s downstream DPSK and 40-Gb/s upstream OOK signal remodulation PON using reduced modulation index

As different high speed signal-remodulation wavelength division multiplexed--passive optical network (WDM-PON) solutions up to 10 Gb/s have been proposed, researchers are going to further increase the data rate of PON towards 40 Gb/s or higher. However, scaling up from 10 Gb/s/wavelength to 40 Gb/s/wavelength PON is very challenging. Although many studies have been performed on upgrading the exiting 10 Gb/s network to 40 Gb/s, the study of the 40 Gb/s signal-remodulation network is very little. In this work, we will first study the chromatic dispersion effect on the signal-remodulation PON. Then, we will propose and demonstrate a signal-remodulation PON using 40-Gb/s downstream differential-phase shift keying (DPSK) and 40-Gb/s upstream on-off keying (OOK) signals. By using the reduced modulation index (RMI) of the downstream DPSK signal, the tolerance to the residual chromatic dispersion of the whole system can be greatly enhanced. Due to the reduced impact of the accumulated chromatic dispersion, the quality of the upstream remodulated OOK signal can be significantly improved. Besides, by detecting the downstream demodulated DPSK signal at the destructive output port of the demodulator, good quality of the demodulated DPSK signal can still be achieved.

Pediatric oncology: the use of cluster analysis to examine maternal concerns

PURPOSE/OBJECTIVES

To examine data from mothers whose children have cancer and to identify the characteristics of uncertainty and distress that they reported. The objectives were (a) to use cluster analysis to identify subgroups of maternal uncertainty and distress, (b) to examine whether the subgroups differed based on demographics and children's illness-related variables, and (c) to explore whether mothers in the subgroups differed on quality of life (QOL) and hope.

DESIGN

Descriptive, correlational study.

SETTING

Pediatric oncology units in northern Taiwan.

SAMPLE

200 mothers of children with cancer.

METHODS

Participants completed the Parental Perception of Uncertainty Scale, the Symptom Checklist-35-Revised, the Short-Form 36 Health Survey, the Herth Hope Index, and a demographic questionnaire. Cluster analyses were used to identify subgroups of mothers regarding maternal perceived uncertainty and distress. Differences in demographic variables, disease characteristics, and outcome measures were evaluated with descriptive statistics, analysis of variance, and chi-square analysis.

MAIN RESEARCH VARIABLES

Subgroup, maternal uncertainty, distress, QOL, and hope.

FINDINGS

Four subgroups were identified by the cluster analyses: high uncertainty and high distress, moderate uncertainty and moderate distress, low uncertainty and low distress, and high uncertainty and low distress.

CONCLUSIONS

The subgroup of mothers who reported low uncertainty and low distress reported the highest QOL and hope.

IMPLICATIONS FOR NURSING

The findings of this study provide insight for pediatric oncology clinicians and offer issues related to uncertainty, distress, and QOL that such professionals can discuss with the mothers of their patients.

Increase of plasma insulin by racecadotril, an inhibitor of enkephalinase, in Wistar rats

Racecadotril is known as an inhibitor of enkephalinase. Increase of plasma insulin by racecadotril has been observed in rats while the mechanism of the action remains obscure. In the present study, intravenous injection of male Wistar rats with racecadotril significantly decreased blood glucose levels. However, this effect of racecadotril was not modified by naloxone at the dose sufficient to block opioid receptors. Thus, the blood glucose-lowering action of racecadotril might be through an endogenous opioid independent mechanism. Otherwise, we found that C-peptide content was also raised by racecadotril in parallel with the increase of insulin in Wistar rats. Thus, the blood glucose-lowering action of racecadotril was related to insulin secretion, but not through the inhibition of plasma insulin degradation. In addition, racecadotril showed no direct effect on insulin secretion in isolated islets or cultured HIT-T15 beta cells. The increase of plasma insulin and blood glucose-lowering action induced by racecadotril were reduced by pretreatment with atropine and enhanced by physotigmine. Direct inhibition of cholinesterase was not observed in brain homogenates treated with racecadotril. Moreover, actions of racecadotril were significantly reduced in rats receiving hemicholinium-3 at a sufficient dose to decrease endogenous acetylcholine. Activation of cholinergic tone is possibly involved in the blood glucose-lowering effect of racecadotril. Our results suggested that racecadotril increased insulin secretion to lower blood glucose mainly via regulation of parasympathetic tone in Wistar rats.

100 GHz ultra-wideband (UWB) fiber-to-the-antenna (FTTA) system for in-building and in-home networks

Fiber-to-the-antenna (FTTA) system can be a cost-effective technique for distributing high frequency signals from the head-end office to a number of remote antenna units via passive optical splitter and propagating through low-loss and low-cost optical fibers. Here, we experimentally demonstrate an optical ultra-wideband (UWB) - impulse radio (IR) FTTA system for in-building and in-home applications. The optical UWB-IR wireless link is operated in the W-band (75 GHz - 110 GHz) using our developed near-ballistic unitraveling-carrier photodiode based photonic transmitter (PT) and a 10 GHz mode-locked laser. 2.5 Gb/s UWB-IR FTTA systems with 1,024 high split-ratio and transmission over 300 m optical fiber are demonstrated using direct PT modulation.

Decrease of bone morphogenetic protein-7 (BMP-7) and its type II receptor (BMP-RII) in kidney of type 1-like diabetic rats

Bone morphogenetic protein-7 (BMP-7) expression is known to be protective for renal damage during diabetic nephropathy and disappears early during the progression of diabetic nephropathy. However, changes in expression of BMP-7 and BMP-7 type II receptor (BMP-RII) during kidney nephropathy response to high glucose-induced oxidative stress remain unclear. In this study, we used streptozotocin-induced diabetic rats with diabetic nephropathy and treated them with insulin, phloridzin, or antioxidant tiron. The insulin, phloridzin, or tiron treatment improved the renal function and decreased fibronectin expression in the streptozotocin-induced diabetic rats. Both insulin and phloridzin could reverse the attenuation effects of hyperglycemia on BMP-7 and BMP-RII expressions in the kidneys of streptozotocin-induced diabetic rats through the correction of hyperglycemia. However, the decrease of BMP-7 and BMP-RII expressions in kidney of streptozotocin-induced diabetic rats could be reversed by tiron through decreasing the high glucose-induced oxidative stress but not through changing the levels of glucose. We further confirmed the effect on reversing the BMP-7 and BMP-RII expressions through decreasing oxidative stress by tiron treatment in high glucose exposed mesangial cells. Thus, we suggest that a decrease in oxidative stress is responsible for the improvement of renal function and recovery of renal BMP-7 and BMP-RII expression in streptozotocin-induced diabetic rats.

Predictive factors for faecal incontinence after third or fourth degree obstetric tears: a clinico-physiologic study

OBJECTIVE

This is a prospective study to review the natural history of anorectal dysfunction after primary repair for third or fourth degree obstetric tear and to identify the predictive factors for significant faecal incontinence.

METHOD

From January 2003 to December 2005, 121 consecutive women (mean age 29.9 +/- 4.7) who sustained third or fourth degree obstetric tears were assessed. All had primary repair by obstetricians. They were assessed using anorectal physiology testing and endoanal ultrasound. Short-term (3-month postpartum) and medium-term (mean 18.8 +/- 7.7 months) Wexner's continence scores were obtained.

RESULTS

Among the 121 women, seven were excluded because of incomplete follow-up. At short-term assessment, 25 out of 114 women were incontinent. One of them underwent another sphincter repair for significant faecal incontinence. Twenty-one and three patients respectively, had mild (Wexner's score 1-4) and moderate (Wexner's score 5-8) symptoms. At medium-term assessment, 24 patients remained incontinent; of these, 20 had mild symptoms (Wexner's score 1-4) and four had moderate incontinence (Wexner's score 5-8). The parity (P = 0.04), degree of obstetric tear (P = 0.036) and short-term Wexner's scores at 3 months postpartum (P < 0.0001) were significantly related to the change in Wexner's scores at medium-term assessment. However, the short-term Wexner's score was the only identifiable predictive factor for significant faecal incontinence.

CONCLUSION

Most women suffering from third or fourth degree obstetric tear were continent or mildly incontinent. Poor Wexner's score at short-term assessment at 3 months postpartum was predictive of faecal incontinence in the medium-term.

A self-protected colorless WDM-PON with 2.5 Gb/s upstream signal based on RSOA

In this investigation, we propose and demonstrate a colorless wavelength division multiplexed passive optical network (WDM-PON) at 2.5 Gb/s using reflective semiconductor optical amplifier (RSOA)-based optical networking units (ONUs); together with a self-protected architecture against fiber fault. In the optical line terminal (OLT), we use an array of self-seeding Fabry-Perot laser diodes (FP-LDs) to provide single-longitudinal-mode (SLM) continuous wave (CW) optical sources for the external injection to the RSOA-based ONUs. The self-survivable function for protecting the fiber fault in the distributed fibers and the proposed network performance are investigated and discussed.

Prospective, case-matched study of heated and humidified carbon dioxide insufflation in laparoscopic colorectal surgery

PURPOSE

Laparoscopic colorectal surgery is often prolonged and may cause hypothermia. It is uncertain if heated and humidified carbon dioxide (CO(2)) in laparoscopic colorectal surgery is beneficial. This is a prospective case-matched study on the use of heated and humidified CO(2) in patients undergoing laparoscopic colorectal surgery.

METHOD

Twenty consecutive patients undergoing laparoscopic colorectal surgery with heated (36 degrees C) and humidified (95%) CO(2) were compared with 20 consecutive patients using standard CO(2) (30.2 degrees C). All procedures were performed by a single surgeon in an institution. The changes in core temperature during surgery, visual quality of images and the short-term clinical outcome were documented.

RESULTS

The core temperature fell during surgery in both groups. Although the fall of core temperature was more in the control group, it was not statistically significant (P > 0.05). The passage of flatus was more delayed in heated and humidified group (P = 0.004), but it did not affect the hospital discharge. All the other parameters, including the quality of visual images and the postoperative pain, were similar in both groups.

CONCLUSIONS

Despite better temperature maintenance (nonsignificant), pneumoperitoneum using heated and humidified CO(2) gas did not appear to have any clinical benefits in laparoscopic colorectal surgery.

Mucin gene expression in cardiac myxoma

Myxoma is the most common benign neoplasm of the heart. This work is the first to present an unusual left atrium and mitral valve cardiac myxoma which cannot be completely resected. This cardiac myxoma was also associated with abundant mucopolysaccharidic matrix, including mucin. Mucin gene expression is cell- and tissue-specific, with variations during cell differentiation and inflammation, and is altered during carcinogenesis. The expression of mucin genes in cardiac myxoma has never been elucidated previously. Detailed immunohistochemical analysis of MUC1, MUC2 and MUC5AC has been performed in this left atrium and mitral valve myxoma. Notably, the expressions of mucins in cardiac myxoma must be further evaluated.

Neurotrophic effects of vascular endothelial growth factor and neurotrophins on cultured major pelvic ganglia

OBJECTIVE

To investigate the feasibility of using a ganglial culture system to screen various growth factors as potential therapeutic agents for pelvic nerve injuries.

MATERIALS AND METHODS

The major pelvic ganglia (MPG) were isolated from male rats and attached to culture dishes with the aid of Matrigel (Becton Dickinson, Mountain View, CA, USA). Alternatively, the dorso-caudal region (DCR) of MPG, from which the cavernous nerves originate, was dissected and then attached to a Matrigel-coated coverslip. The MPG or DCR was cultured in serum-free medium supplemented with phosphate-buffered saline (PBS, control), 50 ng/mL of vascular endothelial growth factor (VEGF), 20 ng/mL of a neurotrophin (BDNF, NT3, or NT4), or combinations of these growth factors. After 2 days of incubation, the ganglial tissues with their outgrowing nerve fibres were stained for the expression of NADPH-diaphorase, tyrosine hydroxylase (TH) and acetylcholinesterase (AChE). The length and staining intensity of nerve fibres were analysed.

RESULTS

The outgrowing fibres were significantly longer in MPG treated with any of the four tested growth factors than in PBS-treated MPG. The combination of VEGF and NT3 induced the best fibre growth. Improvements to the culturing conditions allowed a histological examination of the outgrowing fibres for the expression of nitric oxide synthase (NOS), TH and AChE. VEGF and BDNF were equally capable of inducing NOS- and TH-expressing fibres. BDNF was much weaker than VEGF for inducing AChE-expressing fibres.

CONCLUSIONS

This improved culturing system is potentially useful for screening nerve-regenerating factors; VEGF had neurotrophic effects comparable with BDNF, NT3, or NT4.

A four-day study to evaluate the anti-plaque efficacy of an experimental triclosan-containing dentifrice

Four-day, non-brushing studies have been used successfully to demonstrate the anti-plaque efficacy of triclosan-containing dentifrices. The treatment effects observed are variable, likely due to differences in formulation, study design and measurement techniques. This randomized, double-blind crossover study was conducted to evaluate the anti-plaque efficacy of an experimental, multiple-benefit, triclosan-containing dentifrice versus two currently marketed sodium fluoride dentifrices in a four-day, lingual-brushing model on subjects in Beijing. People's Republic of China. Subjects brushed the lingual surfaces for 30 seconds, and before expectorating, swished the saliva/dentifrice slurry over the buccal surfaces for an additional 30 seconds. This procedure was repeated. Subjects performed their assigned brushing regimen twice daily for four days under supervision. On Day 5, plaque was measured using the Turesky Modification of the Quigley-Hein Plaque Index. There were highly significant treatment effects in favor of the experimental triclosan-containing dentifrice for whole mouth, buccal and lingual sites when compared to either of the sodium fluoride dentifrices (p < 0.0001).

The Chinese version of the Parenting Stress Index: a psychometric study

This study examined the psychometric properties of a Chinese version of the Parenting Stress Index/Short Form (PSI/SF). A 15-item simplified PSI/SF (S-PSI/SF) was subsequently developed which maintained a level of reliability and validity similar to the full version. The Chinese PSI/SF was tested on 149 parents (100 mothers, 49 fathers) of pediatric cancer patients in Taiwan. Psychometric testing was conducted using item analysis, Cronbach's alpha and confirmatory factor analysis. The S-PSI/SF was constructed based on the item analysis of the PSI/SF. Both the PSI/SF and S-PSI/SF produced good reliability coefficients. Confirmatory factor analyses indicated that both PSI/SF and S-PSI/SF met all criteria for goodness of fit. Compared with the PSI/SF, the S-PSI/SF demonstrated better internal consistency and overall fit at the one-subscale level, and satisfactory overall fit at two- and three-subscale levels. Despite the limited number of items included, the S-PSI/SF had a very good factor structure. No gender difference in parenting distress index was observed between mothers and fathers of pediatric cancer patients.

CONCLUSION

The 15-item S-PSI/SF is a brief, easily administered instrument that has evidence of reliability and validity in Taiwanese parents of children with cancer. It could serve as a valuable assessment tool in clinical practice to identify parenting stress with a need for intervention.

Relilgious beliefs and practices of Taiwanese parents of pediatric patients with cancer

The aim of this study was to increase understanding of religious beliefs and practices among Taiwanese parents of pediatric patients. Parents of 63 pediatric patients with cancer were interviewed to explore their related religious beliefs and practices, ie, worship at temple, drawing Chien, and divinations. Rituals were used to diminish the harmful effects of the child's disease, such as temple ceremonies, changing the child's name, and taking "Fu" water. Such practices were generally undertaken with a lack of medical guidance from oncologists largely because of poor interactions between parents and oncologists. The findings suggest that discovering a caregiver's worldview and cultural values is important to establish holistic nursing practices. Because immigrants increasingly move around the world, Taiwanese parents become a culturally diverse clientele for healthcare professionals who have to be aware of the existing cultural differences in healthcare values, patterns, and practices, particularly between Western and Eastern cultures.

Diffractive optical element designed by use of an irregular etching-depth sequence

In fabricating a diffractive optical element the ratio of the etching depth between the (n - 1)th and the nth mask is usually 1/2. We found that the diffraction efficiency of a diffractive optical element can be improved by as much as 7.8% if the above ratio (1/2) is not kept constant. For achieving this improvement the difference between the desired and the actual diffraction pattern is also used as an objective function for phase quantization.

Development and testing of the parental coping strategy inventory (PCSI) with children with cancer in Taiwan

RATIONALE

This study describes the development and psychometric testing of the parental coping strategy inventory (PCSI).

METHODS

The PCSI was developed on the basis of previous qualitative study on the Taiwanese parental adaptation process, when caring for children with cancer. In order to develop the measure of parental coping strategy inventory (PCSI), relevant parameters or items for the assessment subscales were then identified and tested in a three-stage process: item development, content validity testing and reliability testing. The PCSI consisted of 48 items in 12 scales after item selection, and the internal consistency of the scales were acceptable. In order to test the psychometric characteristics of the PCSI, data were collected from 183 mothers with children with cancer.

RESULTS

Confirmatory factor analysis supported a good overall model fit of the construct validity of PCSI. In order to test the generalizability of the factor structure, mothers with children with epilepsy were used. The factorial validity of PCSI was supported from the population of those mothers with children with epilepsy.

CONCLUSIONS

This version of the PCSI was developed with an explicit prior conceptual model based on grounded qualitative study findings. The PCSI is a specified coping behaviour measure with the conceptual framework that adaptation problems can be solved through specific coping strategies. It can be administered in 20 minutes and is the first documented measure of the adaptation process administered directly to Taiwanese parents. It demonstrates acceptable psychometric properties and could be used as a quick screening instrument in evaluating parental problems when caring for children with cancer as well as chronic illness (such as epilepsy, as tested). It could also be used as a predictor of parental adaptation outcome. This report presents preliminary data on the initial instrument development and psychometric properties of PCSI.

Collagen as a drug carrier for deep sternal wound infection after open heart surgery

How to optimally treat deep sternal wound infection after open wound infection remains controversial. Biomaterial advances have made local antibiotics-releasing systems a promising alternative for treating deep sternal wound infection. Two patients with deep sternal wound complications were treated with radical wound debridement, sternal refixation, retrosternal suction drainage, bilateral pectoralis major muscle flaps and placement of collagenous drug carriers loaded with vancomycin underneath, above and between the sternal edges. No treatment failure and death occurred in these patients. There were no side effects, treatment failures or deaths after adjuvant treatment with collagenous vancomycin. Preliminary results of these 2 case studies demonstrate the feasibility of successfully treating deep sternal wound infections with collagenous vancomycin in combination with surgical debridement. This technique is easily performed, reliable and safe.

Requirement for p38 and p44/p42 mitogen-activated protein kinases in RAGE-mediated nuclear factor-kappaB transcriptional activation and cytokine secretion

Advanced glycation end product (AGE) activation of the signal-transducing receptor for AGE (RAGE) has been linked to a proinflammatory phenotypic change within cells. However, the precise intracellular signaling pathways involved have not been elucidated. We demonstrate here that human serum albumin modified with N(epsilon)-(carboxymethyl)lysine (CML), a major AGE adduct that progressively accumulates with aging, diabetes, and renal failure, induced nuclear factor (NF)-kappaB-driven reporter gene expression in human monocytic THP-1 cells. The NF-kappaB response was blocked with a synthetic peptide corresponding to the putative ligand-binding domain of RAGE, with anti-RAGE antiserum, and by coexpression of truncated receptors lacking the intracellular domain. Signal transduction from RAGE to NF-kappaB involved the generation of reactive oxygen species, since reporter gene expression was blocked with the antioxidant N-acetyl-L-cysteine. CML-modified albumin produced rapid transient activation of tyrosine phosphorylation, extracellular signal-regulated kinase 1 and 2, and p38 mitogen-activated protein kinase (MAPK), but not c-Jun NH(2)-terminal kinase. RAGE-mediated NF-kappaB activation was suppressed by the selective p38 MAPK inhibitor SB203580 and by coexpression of a kinase-dead p38 dominant-negative mutant. Activation of NF-kappaB by CML-modified albumin increased secretion of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta, and monocyte chemoattractant protein-1) severalfold, and inhibition of p38 MAPK blocked these increases. These results indicate that p38 MAPK activation mediates RAGE-induced NF-kappaB-dependent secretion of proinflammatory cytokines and suggest that accelerated inflammation may be a consequence of cellular activation induced by this receptor.

Rhodostomin, a snake venom disintegrin, inhibits angiogenesis elicited by basic fibroblast growth factor and suppresses tumor growth by a selective alpha(v)beta(3) blockade of endothelial cells

Angiogenesis consists of the proliferation, migration, and differentiation of endothelial cells, although angiogenic factor and integrin-extracellular matrix interaction modulate this process. We report here that a snake venom-derived disintegrin, rhodostomin, inhibited distinct steps in angiogenesis elicited by basic fibroblast growth factor (bFGF), and also suppressed in vivo murine melanoma tumor growth. Rhodostomin dose-dependently inhibited bFGF-induced human umbilical vein endothelial cell (HUVEC) proliferation as examined by cell number count, metabolic activity, and BrdU incorporation assays with submicromolar IC(50) values. However, it apparently did not affect the viability of murine B16F10 melanoma cells, even up to 50 microM. Rhodostomin also inhibited HUVEC migration and invasion evoked by bFGF, and tube formation of bFGF-treated HUVECs in Matrigel. Moreover, rhodostomin selectively inhibited bFGF-, but not vascular endothelial growth factor-associated angiogenesis in the chick chorioallantoic membrane model. Furthermore, rhodostomin blocked both bFGF- and B16F10-induced neovascularization in murine Matrigel plug model and suppressed the growth of subcutaneously inoculated B16F10 solid tumor, leading to a prolonged survival of the rhodostomin-treated C57BL/6 mice. The antiangiogenic effect of rhodostomin on bFGF-treated HUVECs is related to the integrin alpha(v)beta(3) blockade, as evidenced by its selective inhibition on the binding of 7E3, a monoclonal antibody (mAb) raised against alpha(v)beta(3,) but not that of P1F6, an alpha(v)beta(5) mAb toward both naive and bFGF-primed HUVECs. Moreover, 7E3 specifically blocked fluorescein isothiocyanate-conjugated rhodostomin binding to HUVEC, whereas P1F6 and anti-integrin alpha(2), alpha(3), alpha(4), or alpha(5) mAbs did not.

Viper venom components affecting angiogenesis

Angiogenesis is a complex process consisting of the proliferation, migration and differentiation of endothelial cells, and it is essential for the progression of malignant solid tumors. In this report, we examine the effects of disintegrins (e.g. rhodostomin and accutin) and glycoprotein-lb-binding proteins (e.g. agkistin) on each step in angiogenesis using in vitro and in vivo models. Rhodostomin (but not agkistin) inhibited the viability of human umbilical vein endothelial cells (HUVECs) and capillary tube formation of HUVECs. Rhodostomin also inhibited HUVEC migration and invasion evoked by basic fibroblast growth factor (bFGF). In in vivo studies, rhodostomin inhibited bFGF-, but not vascular-endothelial-growth-factor (VEGF)- associated angiogenesis in chick chorioallantoic membrane model, blocked both bFGF and B16F10 melanoma cell-induced neovascularization, and suppressed the growth of subcutaneously inoculated B16F10 solid tumor, leading to a prolonged survival of the C57BL/6 mice treated with rhodostomin. The antiangiogenic effects of rhodostomin on bFGF-treated HUVECs may be mainly related to the blockade of the interaction of endothelial alpha(v)beta(3) and extracellular matrix.

Adaptation in children with cancer: research with Roy's model

This qualitative study was undertaken to establish a conceptual framework for the adaptation process of Taiwanese children with cancer. It was guided by Roy's adaptation model. Thirty-four pediatric cancer patients (23 boys and 11 girls) with different illness trajectories (from newly diagnosed to terminal stage) participated. Data were collected through individual in-depth interviews with patients and primary caregivers, observations, medical chart review, and researchers' reflective journals. The following five aspects of adaptation that emerged from the study were categorized according to different age groups: physiological and psychological, cognitive (self-concept), interdependence, and future orientation (self-concept and role). Comparison with Roy's adaptation theory is discussed.

Relationship of surface epithelium concentrations of IL-1 alpha and IL-1 beta to clinical inflammation during experimental gingivitis

Experimental evidence has clearly demonstrated that IL-1 cytokine levels increase in experimental gingivitis (EG) models in response to plaque accumulation following the cessation of oral hygiene. These changes in cytokine production are reported to occur prior to visible signs of clinical inflammation, and as such may represent early markers of gingival inflammation. This clinical study used a novel dermal sampling tape as a method to collect cytokines from gingival epithelium, as opposed to the more commonly sampled gingival crevicular fluid. The primary objective of the study was to examine the relationship between changes in cytokine levels and clinical inflammation. Ten subjects participated in a 14-day EG model, where 5 days following a dental prophylaxis subjects refrained from all oral hygiene measures for 14-days. Clinical measures including the Löe-Silness Gingival Index (GI), a bleeding index derived from the GI, and the inflammation index (II) were made at baseline prior to the initiation of the EG period and following 14 days of EG. Dermal tape samples were collected from the right posterior buccal quadrant of each subject at both baseline and day 14. The tapes were extracted and the extracts analyzed for both IL-1 alpha and IL-1 beta by ELISA. Results of this study indicate that over a 14-day EG period statistically significant (p < 0.05) increases in GI, gingival bleeding, II, and IL-1 alpha were observed (tested by matched-pairs t test and Wilcoxon signed ranks test). A directional increase in IL-1 beta was also observed. Linear regression analyses demonstrated a strong positive correlation between the number of gingival bleeding sites from the region of gingiva sampled with Sebutape and IL-1 alpha (r = 0.93), as well as IL-1 beta (r = 0.90). In addition, linear regression analyses also demonstrated a strong positive correlation between the mean II score from the region of gingiva sampled with Sebutape and IL-1 alpha (r = 0.93), as well as IL-1 beta (r = 0.86). Similar correlations were observed for whole mouth scores of the number of gingival bleeding sites and mean II with respect to IL-1 alpha and IL-1 beta levels. Collectively, these data confirm the utility of the dermal tape for sampling epithelium cytokine levels from the gingiva and demonstrate a strong positive correlation between IL-1 alpha and IL-1 beta concentrations and gingival inflammation.

Effects of treatment of secondary hyperparathyroidism on the lipid profile in patients on hemodialysis

Abnormalities in circulating lipoprotein concentrations are a characteristic finding in patients undergoing dialytic therapy. A substantial number of these patients display type IV hyperlipoproteinemia. Certain data suggest that secondary hyperparathyroidism may induce disturbances in lipid metabolism. To evaluate the effects of pulse calcitriol therapy on the lipid profile in these patients, we undertook a prospective study in 12 patients on stable bicarbonate hemodialysis. Lipid parameters comprising cholesterol and the low- as well as the high-density lipoprotein subfractions, triglycerides, apolipoproteins A and B, serum parathyroid hormones (iPTH), alkaline phosphatase, calcium, phosphorus, hematocrit, and blood urea were obtained prior to commencement of pulse calcitriol therapy and again 8-10 weeks later. Calcitriol therapy was associated with a decrease in serum iPTH levels (701 +/- 103.9 vs. 220.3 +/- 50.5 pmol/l; p < 0.001). Significant increases in high-density lipoprotein cholesterol (32.8 +/- 2.7 vs. 38.8 +/- 2.3 mmol/l; p < 0.05) and apolipoprotein A-I (107.8 +/- 6.1 vs. 121.8 +/- 5.8 g/l; p < 0.05) were noted during the course of the study. Moreover, serum iPTH correlated inversely with high-density lipoprotein cholesterol and apolipoprotein A-I. There were no changes in other lipid parameters except for low-density lipoprotein cholesterol which showed a tendency to increase. We conclude that in short-term study, pulse oral calcitriol therapy is associated with an improvement in the lipid profile in patients with secondary hyperparathyroidism. However, it remains to be established whether ameliorating the uremic dyslipidemia results in any long-term clinical benefits.

Anxiety and depression in Taiwanese cancer patients with and without pain

The purpose of this investigation was to compare anxiety and depression in Taiwanese cancer patients with and without pain. In 1998, a convenience sample of 203 hospitalized cancer patients, 77 with pain and 126 without pain, were assessed for anxiety and depression using the Hospital Anxiety and Depression Scale (HADS). Disease-related factors such as performance status, disease stage and perceived treatment effect were also assessed and controlled for their effect on anxiety and depression. The prevalence of both anxiety and depression in the pain group was significantly higher than that for the pain-free group. After controlling the effect of disease-related factors, patients' pain status had a significant effect on depression, but not on anxiety. Patients with pain had more depressive symptoms than patients without pain. Cancer patients' anxiety can be predicted significantly by functional status and perceived treatment effect. In addition to pain status, cancer patients' depression can be predicted by their functional status.

Nadph-diaphorase activity in corpus allatum cells of the cockroach, Diploptera punctata

Using the fixation insensitive NADPH-diaphorase reaction as a histochemical marker for the enzyme nitric oxide synthase (NOS), we investigated the possible sites of putatively NOS-related NADPH-diaphorase in the brain and retrocerebral complex of the cockroach, Diploptera punctata. In the cerebral ganglion, NADPH-diaphorase expression was localized in antennal lobes, optic lobes, mushroom bodies and neurosecretory cells. The highest NADPH activity was detected in the corpora allata (CA). Spectrophotometric quantitation indicated that NADPH-diaphorase activity first increased and then decreased (cycled) in the CA of mated females. In addition, during the first ovarian cycle, NADPH-diaphorase activity fluctuated concurrently with cyclic changes in the size of corpus allatum cells. In virgin females, NADPH-diaphorase activity remained at a low level, but it increased if the neural connectives between CA and brain were severed, indicating that the brain inhibited NADPH-diaphorase expression in the CA. Although nerve terminals were abundant in the CA, NADPH-diaphorase was clearly endogenous and synthesized by glandular cells, as was shown by histochemical staining of the cytosol in all dissociated cells of the CA. We have also demonstrated NADPH-diaphorase activity in the CA of the American cockroach Periplaneta americana, the house cricket Acheta domesticus, the lepidopteran Leucania loreyi, and the fruit fly Drosophila melanogaster, suggesting that NOS occurs in the CA of most, if not all insects. It is therefore possible that corpus allatum cells release NO, along with juvenile hormone, which presumably can function as a messenger molecule.

Agkistin, a snake venom-derived glycoprotein Ib antagonist, disrupts von Willebrand factor-endothelial cell interaction and inhibits angiogenesis

Glycoprotein (GP) Ib, an adhesion receptor expressed on both platelets and endothelial cells, mediates the binding of von Willebrand factor (vWF). Platelet GPIb plays an important role in platelet adhesion and activation, whereas the interaction of vWF and endothelial GPIb is not fully understood. We report here that agkistin, a snake venom protein, selectively blocks the interaction of vWF with human endothelial GPIb and inhibits angiogenesis in vivo. Agkistin specifically blocked human umbilical vein endothelial cell (HUVEC) adhesion to immobilized vWF in a concentration-dependent manner. Fluorescein isothiocyanate (FITC)-conjugated agkistin bound to HUVECs in a saturable manner. AP1, a monoclonal antibody (mAb) raised against GPIb, specifically inhibited the binding of FITC-conjugated agkistin to HUVECs in a dose-dependent manner, but other anti-integrin mAbs raised against alpha(v)beta(3), alpha(2)beta(1), and alpha(5)beta(1) did not affect this binding reaction. However, neither agkistin (2 microgram/ml) nor AP1 (40 microgram/ml) apparently reduced HUVEC viability. Both agkistin and AP1 exhibited a profound anti-angiogenic effect in vivo when assayed by using the 10-day-old embryo chick chorioallantoic membrane model. These results suggest endothelial GPIb plays a role in spontaneous angiogenesis in vivo, and the anti-angiogenic effect of agkistin may be because of disruption of the interaction of endogenous vWF with endothelial GPIb.

Adaptational process of parents of pediatric oncology patients

This study, based on grounded theory, explores the adaptational process of parents of pediatric oncology patients. Thirty-two Taiwanese parents (26 mothers and 6 fathers) were interviewed. Data were collected through individual in-depth and focus group interviews, observations, medical chart review, nurses' note, and researchers' reflexive journals. The findings suggest that parents adapt to their children's cancer by a dynamic process; i.e., they modify their coping tasks and related strategies as clinical events (e.g., diagnosis, side effects, relapses, or death) occur. This adaptational process consisted of five components: confronting treatment, maintaining family integrity, establishing support, maintaining emotional well-being, and searching for spiritual meaning. Related factors such as coping tasks are described.

Use of alternative therapy among pediatric oncology patients in Taiwan

Both alternative medicine and western medicine have been commonly used to treat pediatric cancer patients in Taiwan. Each has its own intrinsic strengths and weaknesses and they can be complementary. Little is known about medical help-seeking behaviors of parents of pediatric cancer patients, especially those related to alternative therapies. This study investigated the extent and parental expectations on use of alternative therapies. All primary caregivers of 63 eligible patients were interviewed. Use of alternative therapies, regardless of education level or social status of their families, is prevalent (n = 46, 73%) in Taiwan. Commonly used alternative therapies included, in order of popularity, formulated functional food (n = 22, 48%), temple worship/shamanism (n = 19, 40%), traditional Chinese medicine (n = 9, 20%), secret recipes/herbs (n = 13, 28%), and diet supplements (n = 9, 19%). Such practices generally occur without medical guidance from oncologists, largely because of poor interactions between parents and oncologists. Future efforts should be made to encourage both parents and oncologists to discuss this issue. Nurses may serve as mediators by developing mutual trust and a sharing relationship between these groups.

Heat shock protein (hsp 70)-related epitopes are common allergenic determinants for barley and corn antigens

IgE reactive components of barley and corn were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotted with sera from workers exposed to complex bioaerosols. The antibody made against Arabdopsis heat shock protein (hsp 70) was used to identify those components equivalent to hsp 70 in molecular size. Components with a molecular mass of 69 kDa and 33 kDa were positively reacted, and immunoblots of two-dimensional polyacrylamide gel electrophoresis were compared.

Molecular characterization of Oryza sativa 16.9 kDa heat shock protein

A rice class I low-molecular-mass heat shock protein (LMM HSP) Oshsp 16.9 was overexpressed in Escherichia coli. Oligomerized complexes of Oshsp16.9 were harvested and electron microscopic observations of purified complexes revealed globular structures of 10-20 nm in diameter (with majority of 15-18 nm) and calculated to comprise approx. 12 monomers per complex. In comparison, complexes from native rice class I LMM HSPs were observed as larger ellipsoid- or globular-like random aggregated hetero-oligomers. To characterize the biochemical functions of the hydrophobic N-terminal region of Oshsp16.9, a truncation in the N-terminal region was constructed and introduced into E. coli. Results showed that the N-terminal truncated Oshsp16.9 mutant was capable of forming complexes similar to the full-length Oshsp16.9; however, the deletion protein failed to confer in vitro protein thermostability under elevated temperatures. Protein assays from in vivo treatments at higher temperatures exhibited that non-specific interactions of E. coli cellular proteins only occurred with full-length Oshsp16.9 complexes but not with the mutant complex. In vitro immunoprecipitation of cellular proteins from E. coli overexpressing full-length Oshsp16.9 showed that interactions between plant LMM HSP and E. coli cellular proteins are temperature-dependent. Taken together, the hydrophobic N-terminal region of rice class I LMM HSP is critical in the ability of the protein to interact/bind with its potential substrates.

Surgical treatment of bronchiectasis: 10 years' experience

BACKGROUND

Since antibiotic therapy and vaccination have been widely used in medical practice, the incidence of bronchiectasis has decreased steadily. The principal role of surgery associated with this disease is for the treatment of complications. We present an analysis of surgical results during a 10-year period.

METHODS

The medical records of bronchiectasis patients who were surgically treated were retrospectively reviewed from July, 1987, to March, 1998. The surgical indications, complications and recurrences of bronchiectasis were evaluated.

RESULTS

A total of 41 bronchiectasis patients underwent surgical treatment from 1987 to 1998 at our hospital. There were 18 males (mean age, 37.8 +/- 15.3 years; range, 16-73 years), and 23 females (mean age, 33 +/- 7.1 years; range, 21-46 years). The indications for surgery were hemoptysis in 30, failed medical treatment in eight, suspected neoplasm in two and retention of a foreign body in one patient. Anatomic resections of the diseased sites were carried out more frequently on the left lower lobes of the lungs. In total, there were 20 left lower lobes, five right lower lobes, 10 left lingular lobes, five right middle lobes, four left upper lobes and one right upper lobe that required surgery. Surgical complications included hemorrhage in one patient, bronchopleural fistula in one and galactorrhea in one patient. The follow-up intervals were from two to 131 months (mean, 72.5 +/- 37.6 months; median, 74 months). There were two cases of recurrent symptoms and six cases of recurrent hemoptysis; all were easily controlled by medication. There were no mortalities.

CONCLUSIONS

Surgical treatment of bronchiectasis yields immediate resolution of symptoms, better quality of life and no mortalities. Cessation of smoking, avoiding air pollution and careful medical follow-up are mandatory.

Role of the outward delayed rectifier K+ current in ceramide-induced caspase activation and apoptosis in cultured cortical neurons

We studied the novel hypothesis that an up-modulation of channels for outward delayed rectifier K+ current (I(K)) plays a key role in ceramide-induced neuronal apoptosis. Exposure for 6-10 h to the membrane-permeable C2-ceramide (25 microM) or to sphingomyelinase (0.2 unit/ml), but not to the inactive ceramide analogue C2-dihydroceramide (25 microM), enhanced the whole-cell I(K) current without affecting the transient A-type K+ current and increased caspase activity, followed by neuronal apoptosis 24 h after exposure onset. Tetraethylammonium (TEA) or 4-chloro-N,N-diethyl-N-heptylbenzenebutanaminium tosylate (clofilium), at concentrations inhibiting I(K), attenuated the C2-ceramide-induced caspase-3-like activation as well as neuronal apoptosis. Raising extracellular K+ to 25 mM similarly blocked the C2-ceramide-induced cell death; the neuroprotection by 25 mM K+ or TEA was not eliminated by blocking voltage-gated Ca2+ channels. An inhibitor of tyrosine kinases, herbimycin A (10 nM) or lavendustin A (0.1-1 microM), suppressed I(K) enhancement and/or apoptosis induced by C2-ceramide. It is suggested that ceramide-induced I(K) current enhancement is mediated by tyrosine phosphorylation and plays a critical role in neuronal apoptosis.

Cytokines modulate integrin alpha(v)beta(3)-mediated human endothelial cell adhesion and calcium signaling

Angiogenesis is a complex process regulated by the interactions of endothelial cells with cytokines and the adhesive protein matrix. The cytokines basic fibroblast growth factor (bFGF) and tumor necrosis factor-alpha (TNF-alpha) are two of the modulators of angiogenesis. One mechanism by which these cytokines induce their effects may be through the regulation of integrin adhesion receptor activity, in particular, alpha(v)beta(3). In this study, we examined the ability of these angiogenic factors to modulate the adhesion of human umbilical vein endothelial cells (HUVECs) to immobilized disintegrins (i.e., rhodostomin and arietin), which are specific in antagonizing integrin alpha(v)beta(3) in cells. As these disintegrins were immobilized as substrates, they acted as agonists to induce HUVEC adhesion in a dose- and alpha(v)beta(3)-dependent manner. In addition, adhesion also triggered a sustained increase of intracellular free calcium. Furthermore, bFGF-primed HUVECs potentiated, but TNF-alpha primed cells attenuated, about 50% adhesion events and calcium signaling triggered by immobilized disintegrin compared to naive cells, respectively. The mechanisms of modulating alpha(v)beta(3)-dependent HUVEC adhesion by cytokines may be related to changes of integrin alpha(v)beta(3) conformation, as demonstrating the antagonistic effect of Mn(2+) on decreased adhesion by TNF-alpha pretreatment, and confirmed with flow cytometric analysis probed by anti-LIBS1 mAb. However, cytokine pretreatment did not alter the expression of this integrin on the cell surface, as determined by flow cytometry. Phosphoinositide-3 kinase may be one of the signaling molecules involved in the enhanced adhesion of bFGF-primed cells.

Determinants of parental decisions on 'drop out' from cancer treatment for childhood cancer patients

Little is known about the psychosocial process of parental decisions on 'drop out' from cancer treatment for paediatric patients in Taiwan. This study, based on structured in-depth interviews, attempted to document the determinants of parental decisions on drop out. A total of 19 parents of paediatric cancer patients who dropped out from a cancer treatment for at least a month within 3 years since first treatment were interviewed. Content analysis of qualitative data revealed six categories of determinants associated with parental decisions: suffering severe pain from medical treatments and adverse side-effects; desire for better and less painful treatments; adverse effect of other patients' experiences; searching for possible explanations for disease after prolonged denial of diagnosis; lack of empathy from health care professionals; and misinterpretation of improved prognostics. These findings reflected the deficiency of psychological and emotional support for parents from health care professionals prior to and during cancer treatment.

Noise reduction of VQ encoded images through anti-gray coding

Noise reduction of VQ encoded images is achieved through the proposed anti-gray coding (AGC) and noise detection and correction scheme. In AGC, binary indices are assigned to the codevector in such a way that the 1-b neighbors of a code vector are as far apart as possible. To detect the channel errors, we first classify an image into uniform and edge regions. Then we propose a mask to detect the channel errors based on the image classification (uniform or edge region) and the characteristics of AGC. We also mathematically derive a criterion for error detection based on the image classification. Once error indices are detected, the recovered indices can be easily chosen from a "candidate set" by minimizing the gray-level transition across the block boundaries in a VQ encoded image. Simulation results show that the proposed technique provides detection results with smaller than 0.1% probability of error and more than 86.3% probability of detection at a random bit error rate of 0.1%, while the undetected errors are invisible. In addition, the proposed detection and correction techniques improve the image quality (compared with that encoded by AGC) by 3.9 dB.

A new short chain RGD-containing disintegrin, accutin, inhibits the common pathway of human platelet aggregation

A new short-chain disintegrin, accutin, was purified from the Formosan Agkistrodon acutus venom by using of gel filtration, ion exchanger and reverse phase HPLC. The homogeneous protein is a 47-residue polypeptide with a molecular mass of 5241 Da containing an Arg-Gly-Asp sequence and seven cysteinyl residues at positions highly homologous to other disintegrins. Accutin dose-dependently inhibited human platelet aggregation stimulated by ADP, collagen, thrombin or the thromboxane analogue U46619 in platelet suspension with IC50 values of 66-267 nM. It was also active in inhibiting platelet aggregation of platelet-rich plasma. However, accutin apparently did not affect the shape change caused by these agonists. Accutin also inhibited fibrinogen-induced aggregation of human elastase-treated platelets in a dose-dependent manner. Furthermore, accutin dose-dependently inhibited the binding reaction of fluorescein isothiocyanate (FITC)-conjugated arietin, a member of the disintegrin family, to human platelets. In addition, the binding of FITC-conjugated accutin to platelets was almost completely blocked by a monoclonal antibody, 7E3, raised against the platelet glycoprotein IIb/IIIa complex. On the other hand, accutin as well as other disintegrins, rhodostomin and arietin, exhibited an inhibitory effect on 7E3 binding toward platelets and endothelial cells in a dose-dependent manner. It is concluded that accutin, a new platelet aggregation inhibitor belonging to the short-chain disintegrin family, acts specifically on a binding epitope of GPIIb/IIIa overlapping with that of 7E3, leading to the blockade of fibrinogen binding to its receptor.

Clinical analysis of inflammatory masses of the pancreatic head region

BACKGROUND/AIMS

Inflammatory masses of the pancreatic head are a dilemma for surgeons, especially when the differences between these lesions and pancreatic head carcinoma are not so clear. The surgical management of these inflammatory benign lesions is also a topic with conflicting opinions. A clinical analysis was performed in an attempt to differentiate between these lesions and malignancy. The results of our observatory strategy of these lesions are also presented.

METHODOLOGY

From 1992 to 1994, 73 patients with ultrasonographically (US) or computed tomographically (CT) heterogenous pancreatic head lesions were diagnosed at the Department of Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan. Forty-nine of these lesions were neoplastic (Group I), but the remaining 24 patients had inflammatory non-neoplastic lesions (pancreatic inflammatory masses, IPM, Group II), which were diagnosed during laparotomy by core needle biopsy. Surgery and outcome were reviewed. Ten of the 24 patients in group II received biopsy only, and the remaining 14 patients received bypass procedures. At follow-up of at least 16 months of the surviving patients (n=21), only 9.5% were with residual lesions. All cases in group II revealed shrinkage of masses. We focused on the clinical features, hematology, biochemistry, image study, serum CEA and CA 19-9, and compared these variances between the 2 groups.

RESULTS

Three clinical features were statistically different between groups I and II: mean age at presentation of disease (group I vs II = 53.3 vs 65.1), the tendency of a past history of alcoholism (Group II), and presence of abdominal pain (Group II). Group II also showed a higher level of serum alkaline phosphatase and a lower level of total bilirubin as well as a lower level of CA19-9. These inflammatory masses could not be distinguished from the true neoplasms pre-operatively on endoscopic appearance, US, or CT.

CONCLUSIONS

Pre-operative differentiation between these pancreatic lesions may be difficult but laparotomy and core needle biopsy remain safe and reliable procedures. Our short-term follow-up justified the bypass surgery and that observatory strategy is enough for those patients with pancreatic head inflammatory masses.

Accutin, a new disintegrin, inhibits angiogenesis in vitro and in vivo by acting as integrin alphavbeta3 antagonist and inducing apoptosis

Endothelial integrins play an essential role in angiogenesis and cell survival. Accutin, a new member of disintegrin family derived from venom of Agkistrodon acutus, potently inhibited human platelet aggregation caused by various agonists (eg, thrombin, collagen, and, adenosine diphosphate [ADP]) through the blockade of fibrinogen binding to platelet glycoprotein IIb/IIIa (ie, integrin alphaIIbbeta3). In this report, we describe that accutin specifically inhibited the binding of monoclonal antibody (MoAb) 7E3, which recognizes integrin alphavbeta3, to human umbilical vein endothelial cells (HUVECs), but not those of other anti-integrin MoAbs such as alpha2beta1, alpha3beta1, and alpha5beta1. Moreover, accutin, but not the control peptide GRGES, dose-dependently inhibited the 7E3 interaction with HUVECs. Both 7E3 and GRGDS, but not GRGES or Integrelin, significantly blocked fluorescein isothiocyanate-conjugated accutin binding to HUVEC. In functional studies, accutin exhibited inhibitory effects on HUVEC adhesion to immobilized fibrinogen, fibronectin and vitronectin, and the capillary-like tube formation on Matrigel in a dose- and RGD-dependent manner. In addition, it exhibited an effective antiangiogenic effect in vivo when assayed by using the 10-day-old embryo chick CAM model. Furthermore, it potently induced HUVEC apoptotic DNA fragmentation as examined by electrophoretic and flow cytometric assays. In conclusion, accutin inhibits angiogenesis in vivo and in vitro by blocking integrin alphavbeta3 of endothelial cells and by inducing apoptosis. The antiangiogenic activity of disintegrins might be explored as the target of developing the potential antimetastatic agents.

Totally minimally invasive cardiac surgery for coronary artery disease

OBJECTIVE

We report our experience using minimally invasive techniques both to perform coronary artery bypass and harvesting of saphenous vein grafts in 25 patients with left main or triple vessels disease.

METHODS

From March 1997 to June 1997, 25 patients received elective coronary artery bypass grafting using minimally invasive surgical techniques for left main or triple vessels disease. Saphenous vein grafts were harvested using minimally invasive techniques under direct vision. The coronary artery bypass grafting was performed through a limited left anterior parasternal minithoracotomy under femoro-femoral or aorto-atrial cardiopulmonary bypass. The myocardium was protected by antegrade infusion of cold blood cardioplegic solution while the aorta was cross-clamped.

RESULTS

Three to four distal anastomoses were performed with the saphenous vein graft and the left internal thoracic arterial graft. The aortic cross-clamp time was 60-135 min. The duration of cardiopulmonary bypass was 89-172 min. The postoperative course was uneventful for all patients. All patients were found to be in New York Heart Association functional class I or II on follow-up from 3-7 months after surgery.

CONCLUSIONS

Minimally invasive coronary artery surgery is technically feasible and can be performed in left main or triple vessel disease safely and effectively for complete revascularization.

Involvement of de novo ceramide biosynthesis in tumor necrosis factor-alpha/cycloheximide-induced cerebral endothelial cell death

Cytokines, including tumor necrosis factor-alpha (TNF-alpha), may elicit cytotoxic response through the sphingomyelin-ceramide signal transduction pathway by activation of sphingomyelinases and the subsequent release of ceramide: the universal lipid second messenger. Treatment of bovine cerebral endothelial cells (BCECs) with TNF-alpha for 16 h followed by cycloheximide (CHX) for 6 h resulted in an increase in ceramide accumulation, DNA fragmentation, and cell death. Application of a cell permeable ceramide analogue C2 ceramide, but not the biologically inactive C2 dihydroceramide, also induced DNA laddering and BCEC death in a concentration- and time-dependent manner. TNF-alpha/CHX-mediated ceramide production apparently is not a result of sphingomyelin hydrolysis because sphingomyelin content does not decrease in this death paradigm. In addition, an acidic sphingomyelinase inhibitor, desipramine, had no effect on TNF-alpha/CHX-induced cell death. However, addition of fumonisin B1, a selective ceramide synthase inhibitor, attenuated TNF-alpha/CHX-induced intracellular ceramide elevation and BCEC death. Together, these findings suggest that ceramide plays at least a partial role in this paradigm of BCEC death. Our results show, for the first time, that ceramide derived from de novo synthesis is an alternative mechanism to sphingomyelin hydrolysis in the BCEC death process initiated by TNF-alpha/CHX.

Enhancement of outward potassium current may participate in beta-amyloid peptide-induced cortical neuronal death

In light of recent evidence implicating the upregulation of outward K+ current in mediating several forms of neuronal apoptosis, we tested the hypothesis that such an upregulation might specifically contribute to the pathogenesis of beta-amyloid peptide (A beta)-induced neuronal death. Exposure to A beta fragment 25-35 (20 microM) or 1-42 (20 microM) enhanced the delayed rectifier K+ current IK, shifting its activation voltage relationship toward hyperpolarized levels and increasing maximal conductance, but did not affect the transient K+ current IA or charybdotoxin-sensitive BK current. Reducing IK by adding the channel blocker tetraethylammonium (TEA, 5 mM) or raising extracellular K+ to 25 mM attenuated A beta-induced neuronal death, even in the presence of nifedipine or gadolinium to block associated increases in Ca2+ influx. The IA blocker 4-aminopyridine (4-AP, 5 mM) and the CI- channel blocker anthracene-9-carboxylic acid (ACA, 500 microM) were not neuroprotective. These data raise the intriguing possibility that manipulations aimed at reducing outward K+ current may provide an approach to reducing neuronal degeneration in patients with Alzheimer's disease.

Involvement of de novo ceramide biosynthesis in tumor necrosis factor-alpha/cycloheximide-induced cerebral endothelial cell death

Cytokines, including tumor necrosis factor-alpha (TNF-alpha), may elicit cytotoxic response through the sphingomyelin-ceramide signal transduction pathway by activation of sphingomyelinases and the subsequent release of ceramide: the universal lipid second messenger. Treatment of bovine cerebral endothelial cells (BCECs) with TNF-alpha for 16 h followed by cycloheximide (CHX) for 6 h resulted in an increase in ceramide accumulation, DNA fragmentation, and cell death. Application of a cell permeable ceramide analogue C2 ceramide, but not the biologically inactive C2 dihydroceramide, also induced DNA laddering and BCEC death in a concentration- and time-dependent manner. TNF-alpha/CHX-mediated ceramide production apparently is not a result of sphingomyelin hydrolysis because sphingomyelin content does not decrease in this death paradigm. In addition, an acidic sphingomyelinase inhibitor, desipramine, had no effect on TNF-alpha/CHX-induced cell death. However, addition of fumonisin B1, a selective ceramide synthase inhibitor, attenuated TNF-alpha/CHX-induced intracellular ceramide elevation and BCEC death. Together, these findings suggest that ceramide plays at least a partial role in this paradigm of BCEC death. Our results show, for the first time, that ceramide derived from de novo synthesis is an alternative mechanism to sphingomyelin hydrolysis in the BCEC death process initiated by TNF-alpha/CHX.

Association between interleukin-8 concentration in nasal secretions and severity of symptoms of experimental rhinovirus colds

The purpose of this study was to examine the association between experimental rhinovirus infection and the elaboration of interleukin-8 (IL-8) into nasal secretions of volunteers and to determine the effect of pentoxifylline on IL-8 elaboration and rhinovirus-associated common cold symptoms. Fifty-four subjects with experimental rhinovirus infections and 20 sham-inoculated subjects were studied. Pentoxifylline had no effect on rhinovirus-induced symptoms or nasal-secretion IL-8 concentrations. IL-8 concentrations were significantly greater in nasal secretions from infected symptomatic subjects than in those from infected asymptomatic or sham-challenged subjects on days 2-4 after virus challenge. In infected subjects, there was significant rank correlation between nasal obstruction severity, rhinorrhea severity, and nasal-wash albumin concentrations and the change in IL-8 concentration from baseline on days 2-4 after virus challenge.

Computed tomography in the diagnosis of adult midgut rotational anomalies: a report of two cases

Adult midgut rotational anomalies are difficult to diagnose. Any symptoms present in adults may be the result of intermittent volvulus of the midgut. Successful outcome of this clinical condition depends on prompt diagnosis and timely surgical intervention. Computed tomography (CT) is useful in early identification of these lesions in the abdomen. However, the specific CT signs, the "superior mesenteric vein rotation" sign and the "whirl" sign, are easy to overlook if not kept in mind, as occurred in one of our two patients. In the other patient, CT played the major role in preoperative diagnosis.

Midodrine for the treatment of intradialytic hypotension

Recurrent intradialytic hypotension is probably the most severely disabling feature in dialysis patients and the etiology is multifactorial. We assessed the efficacy and safety of midodrine, a selective alpha1-adrenergic pressor agent in 12 patients with recurrent intradialytic hypotension. Symptomatic intradialytic hypotension was defined as hypotensive symptoms occurring with a systolic blood pressure < 100 mm Hg or with 25% decrease in systolic blood pressure in those patients with a basal systolic blood pressure of 100 mm Hg. The patients who suffered from symptomatic intradialytic hypotension and failed to improve after cautious body weight adjustment were included into the study. The lowest intradialytic and postdialysis blood pressures were monitored for 18 consecutive dialysis sessions before and after midodrine treatment. Clinical signs and symptoms were also recorded during both periods. With midodrine, the mean (+/- SE) lowest systolic and diastolic blood pressure increased significantly from 68.7 +/- 3.1 and 42.8 +/- 2.0 mm Hg to 84.7 +/- 3.9 and 52.7 +/- 2.7 mm Hg respectively during the study (p < 0.01). Midodrine treatment also significantly increased postdialysis systolic and diastolic blood pressures from baseline values of 90.8 +/- 3.8 and 58.3 +/- 3.0 mm Hg to 113.3 +/- 7.1 and 70.6 +/- 3.1 mm Hg (p < 0.01 and p < 0.01 respectively). In addition, oral administration of midodrine also significantly decreased the total volume of intravenous fluid administered during symptomatic hypotension. The clinical signs and symptoms during dialysis were improved in all patients. There were no differences in hemoglobin, serum albumin, urea, creatinine, fasting blood sugar or volume removed per dialysis between both periods of the study. In conclusion, our study has demonstrated that midodrine is a safe and effective treatment for the prevention of recurrent intradialytic hypotension if routinely premedicated before each dialysis session.

Mediation of neuronal apoptosis by enhancement of outward potassium current

Apoptosis of mouse neocortical neurons induced by serum deprivation or by staurosporine was associated with an early enhancement of delayed rectifier (IK) current and loss of total intracellular K+. This IK augmentation was not seen in neurons undergoing excitotoxic necrosis or in older neurons resistant to staurosporine-induced apoptosis. Attenuating outward K+ current with tetraethylammonium or elevated extracellular K+, but not blockers of Ca2+, Cl-, or other K+ channels, reduced apoptosis, even if associated increases in intracellular Ca2+ concentration were prevented. Furthermore, exposure to the K+ ionophore valinomycin or the K+-channel opener cromakalim induced apoptosis. Enhanced K+ efflux may mediate certain forms of neuronal apoptosis.

Expression of a gene encoding a 16.9-kDa heat-shock protein, Oshsp16.9, in Escherichia coli enhances thermotolerance

A gene encoding the rice 16.9-kDa class I low-molecular-mass (LMM) heat-shock protein (HSP), Oshsp16.9, was introduced into Escherichia coli using the pGEX-2T expression vector to analyze the possible function of this LMM HSP under heat stress. It is known that E. coli does not normally produce class I LMM HSPs. We compared the survivability of E. coli XL1-Blue cells transformed with a recombinant plasmid containing a glutathione S-transferase (GST)-Oshsp16.9 fusion protein (pGST-FL cells) with the control E. coli cells transformed with the pGEX-2T vector (pGST cells) under heat-shock (HS) after isopropyl beta-D-thiogalactopyranoside induction. The pGST-FL cells demonstrated thermotolerance at 47.5 degrees C, a treatment that was lethal to the pGST cells. When the cell lysates from these two E. coli transformants were heated at 55 degrees C, the amount of protein denatured in the pGST-FL cells was 50% less than that of the pGST cells. Similar results as pGST-FL cells were obtained in pGST-N78 cells (cells produced a fusion protein with only the N-terminal 78 aa in the Oshsp16.9 portion) but not in pGST-C108 cells (cells produced a fusion protein with C-terminal 108 aa in the Oshsp16.9 portion). The acquired thermotolerant pGST-FL cells synthesized three types of HSPs, including the 76-, 73-, and 64-kDa proteins according to their abundance at a lethal temperature of 47.5 degrees C. This finding indicates that a plant class I LMM HSP, when effectively expressed in transformed prokaryotic cells that do not normally synthesize this class of LMM HSPs, may directly or indirectly increase thermotolerance.