[Effects of climate and land use change on the changes of vegetation coverage in farming-pastoral ecotone of Northern China]

Based on the remote sensing images and the meteorological data in 1986 and 2000, and by using the model of extracting vegetation coverage, the spatiotemporal changes of vegetation coverage in the farming-pastoral ecotone of Northern China in 1986-2000 were studied, with the effects of climate and land use change on the changes analyzed. The results showed that in this ecotone, the area with lower vegetation coverage was increasing, while that with higher vegetation coverage was in adverse. The regions with increasing vegetation coverage were mainly in the east of northeast section, the west of north section, and the west of northwest section of the ecotone, while the vegetation coverage in the other sections was obviously degraded. The vegetation coverage were positively correlated with precipitation and aridity index, but negatively correlated with temperature. The change direction and extent of the vegetation coverage varied with land use types.

Aromatase inhibitors in ovarian cancer: is there a role?

Estrogen plays a role in ovarian tumorigenesis. Aromatase is the enzyme required for the synthesis of estrogen via conversion of androgen to estrogen, which is the major source of estrogen in postmenopausal women. Aromatase is present in normal ovaries and other tissues (e.g., fat and muscle) as well as in 33-81% tumor tissues of ovarian cancer. Aromatase inhibitors (AIs) block estrogen synthesis by inhibiting aromatase activity. In patients with recurrent ovarian cancer, single-agent AI therapy has been shown to elicit clinical response rates of up to 35.7% and stable disease rates of 20-42%. Given the limited treatment options for recurrent ovarian cancer and the favorable safety profile and convenient use, AI is a rational option for prolonging platinum-free interval in recurrent ovarian cancer. Further studies are required to determine the efficacy of combination treatment with AIs and biological agents, determine the benefit of AIs for treating special types of ovarian cancer (e.g., endometrioid type), and identify biomarkers for targeted patient selection. This review summarizes the current epidemiologic, preclinical, and clinical data regarding estrogen's role in ovarian cancer, the expression and regulation of aromatase in this disease, the development and characteristics of the three generations of AIs, and the preclinical and clinical studies of AIs in the treatment of ovarian cancer.

Iron-generated hydroxyl radicals kill retinal cells in vivo: effect of ferulic acid

Siderosis bulbi is vision threatening. An investigation into its mechanisms and management is crucial. Experimental siderosis was established by intravitreous administration of an iron particle (chronic) or FeSO4 (acute). After siderosis, there was a significant dose-responsive reduction in eletroretinogram (a/b-wave) amplitude, and an increase in •OH level, greater when caused by 24 mM FeSO4 than that by 8 mM FeSO4. Furthermore, the FeSO4-induced oxidative stress was significantly blunted by 100 μM ferulic acid (FA). Siderosis also resulted in an excessive glutamate release, increased [Ca++]i, and enhanced superoxide dismutase immunoreactivity. The latter finding was consistent with the Western blot result. Obvious disorganization including loss of photoreceptor outer segments and cholinergic amacrines together with a wide-spreading ferric distribution across the retina was present, which were related to the eletro-retinographic and pathologic dysfunctions. Furthermore, b-wave reduction and amacrine damage were respectively, significantly, dose-dependently, and clearly ameliorated by FA. Thus, siderosis stimulates oxidative stress, and possibly, subsequent excitotoxicity, and calcium influx, which explains why the retina is impaired electro-physiologically and pathologically. Importantly, FA protects iron toxicity perhaps by acting as a free radical scavenger. This provides an approach to the study and treatment of the iron-related disorders such as retained intraocular iron and Alzheimer disease.

Different small-dose sufentanil blunting cardiovascular responses to laryngoscopy and intubation in children: a randomized, double-blind comparison

BACKGROUND

Sufentanil is a potent opioid analgesic frequently used in clinical anaesthesia. This prospective, randomized, double-blind study was designed to assess the efficacy of different small-dose sufentanil attenuating the cardiovascular intubation response in healthy children, aiming at determining the optimal dose of sufentanil for this purpose.

METHODS

A total of 165 children aged 3-9 yr were randomized to one of four groups to receive the following in a double-blind manner: normal saline (Group 1), sufentanil 0.1 microg kg(-1) (Group 2), sufentanil 0.2 microg kg(-1) (Group 3), and sufentanil 0.3 microg kg(-1) (Group 4). Anaesthesia was induced with propofol 2.5 mg kg(-1) and vecuronium 0.1 mg kg(-1). Non-invasive blood pressure (BP) and heart rate (HR) were recorded before induction of anaesthesia (baseline value), at immediately before intubation (post-induction values), at intubation, and at 1 min intervals for 5 min after intubation. The per cent changes of systolic blood pressure (SBP) and HR during the observation were calculated.

RESULTS

Except for Group 4, tracheal intubation caused significant increases in BP and HR in Groups 1, 2, and 3 compared with baseline values. BP and HR at intubation and their maximum values during the observation were significantly different among the four groups. The maximum per cent increases of SBP and HR during the observation were 20 and 28% of baseline values, respectively, in Group 2, 13 and 13% in Group 3, and 0 and 4% in Group 4 compared with 24 and 37% in Group 1. Except for the Group 3 vs Group 4 comparison, the incidences of SBP and HR per cent increases >30% of baseline values were also significantly different among the four groups.

CONCLUSIONS

In combination with propofol for induction of anaesthesia in children, the bolus administration of sufentanil can produce a dose-related attenuation of the cardiovascular intubation response and sufentanil 0.3 microg kg(-1) can completely abolish the cardiovascular intubation response.

Structural evolution and adhesion of titanium oxide film containing phosphorus and calcium on titanium by anodic oxidation

This study investigated the microstructure evolution and defects of the titanium oxide layer containing calcium (Ca) and phosphorus (P) formed by anodic oxidation in a solution containing Ca and P compounds. Results show that the anodic film exhibited a two-layer structure: a pore-containing amorphous titanium oxide layer dispersed with nano-sized crystallites formed prior to sparking, and a porous overlay dotted with craters formed after sparking. Ca and P were predominantly incorporated in the porous overlay, in which the amorphous region contained more Ca and P than the crystalline region regardless of the anodizing voltages. Moreover, the ratio of amorphous to crystalline regions in the porous overlay changed insignificantly with anodizing voltage. Increasing anodizing voltage enhanced the incorporation of Ca and P in the anodic film, but deteriorated the adhesion of the anodic film to the substrate. This deterioration was related to two inherent adhesive weaknesses: the aligned pores in the titanium oxide layer and the craters in the major overlay, signifying that a new anodic oxidation process that can produce high Ca- and P-containing oxide film at relatively-low anodizing voltages, i.e. approximately 200 V, is a necessity.

Effects of neferine on cytosolic free calcium concentration in corpus cavernosum smooth muscle cells of rabbits

To study the relaxation mechanisms of neferine (Nef) on the corpus cavernosum smooth muscle (CCSM), the CCSM cells from New Zealand White rabbits were cultured in vitro. [Ca(2+)](i) was measured by fluorescence ion digital imaging system (FIDIS), using Fluo-2/AM as a Ca(2+)-sensitive fluorescent indicator. Nef (0.1, 1 and 10 micromol l(-1)) had no effect on the resting [Ca(2+)](i) (P > 0.05). In the presence of extracellular Ca(2+) (2.5 mmol l(-1)), Nef (0.1, 1 and 10 micromol l(-1)) inhibited [Ca(2+)](i) elevation induced by high K(+) and phenylephrine (PE) in a concentration-dependent manner (P < 0.05). In calcium free solution containing egtaic acid (EGTA), Nef (0.1 micromol l(-1)) had no inhibitory effects on [Ca(2+)](i) elevation induced by PE (P > 0.05). However, Nef (1 and 10 micromol l(-1)) inhibited [Ca(2+)](i) elevation induced by PE (P < 0.05). These data suggest that Nef inhibited [Ca(2+)](i) in CCSM cells via blocking voltage-dependent Ca(2+) channel, alpha(1)-adrenoceptor-operated Ca(2+) channel and Ca(2+) release from intracellular Ca(2+) pool. This inhibitory action on [Ca(2+)](i) might be one of the relaxation mechanisms of Nef on the CCSM.

Systemic anticancer therapy in gynecological cancer patients with renal dysfunction

Chronic kidney disease is a common occurrence in patients with gynecological cancer. Systemic anticancer treatment in such patients is a challenge for clinicians because of altered drug pharmacokinetics. For those drugs that are excreted mainly by the kidneys, decreased renal function may lead to increased systemic exposure and increased toxicity. Dose adjustment based on pharmacokinetic changes is required in this situation to avoid life-threatening toxicity. In this review, we summarize the nephrotoxicity and pharmacokinetic data of agents commonly used in systemic anticancer treatment of gynecological cancers and dose adjustment guidelines in the presence of impaired renal function. We review 17 medications that need dose adjustment (cisplatin, carboplatin, doxorubicin, epirubicin, cyclophosphamide, ifosfamide, topotecan, irinotecan, etoposide, capecitabine, bleomycin, methotrexate, actinomycin D, granulocyte-macrophage colony-stimulating factor, metoclopramide, cimetidine, and diphenhydramine) as well as 27 drugs that do not (paclitaxel, docetaxel, pegylated liposomal doxorubicin, gemcitabine, oxaliplatin, fluorouracil, vincristine, letrozole, anastrozole, tamoxifen, leuprorelin, megestrol, gefitinib, erlotinib, trastuzumab, leucovorin, granulocyte colony-stimulating factor, erythropoietin, ondansetron, granisetron, palonosetron, tropisetron, dolasetron, aprepitant, dexamethasone, lorazepam, and diazepam). We also review the formulae commonly used to estimate creatinine clearance, including Cockcroft-Gault, Chatelut, Jelliffe, Wright, and the Modification of Diet in Renal Disease study formulae.

Contaminants-induced oxidative damage on the carp Cyprinus carpio collected from the upper Yellow River, China

The Yellow River, the second largest river in China, is the most important resource of water supply in North China. In the last 40 years, even in the upper Yellow River, with the development of industry and agriculture, more and more contaminants have been discharged into this river and greatly polluted the water. Although a routine chemical component analysis has been performed, little is known about the real toxic effects of the polluted water on organisms at environmental level. To explore whether the pollutants induced oxidative stress and damage to aquatic organisms, malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in hepatopancreas, kidney and intestine of the field-collected carp Cyprinus carpio from a mixed polluted (Lanzhou Region, LZR) and a relatively unpolluted (Liujiaxia Region, LJXR) sites of the upper Yellow River were measured. The results showed that when the values of LZR compared with those of LJXR, SOD and GST activities increased and GPx activity decreased significantly in all the three organs (P < 0.05-0.01); CAT activity decreased but MDA level increased significantly (P < 0.05-0.01) only in kidney and intestine. In conclusion, the results of this study suggest that the pollutants can induce obvious oxidative damage in the carp, and the SOD, GST and GPx might be better indicators for the oxidative damage in aquatic organisms.

Changes in free polyamine titers and expression of polyamine biosynthetic genes during growth of peach in vitro callus

In the present paper, correlation between free polyamines and growth of peach (Prunus persica cv. Yuzora) in vitro callus was investigated. Growth of the callus was divided into three phases based on measurement of fresh weight. Free polyamines, putrescine (Put), spermidine (Spd), and spermine (Spm), could be detected during peach callus growth. Changes in free Put titers followed the callus growth rate, as shown by low and stable levels in the first stage, quick increase at the beginning of the second phase, and slow increase in the last phase, whereas fluctuations of Spd and Spm titers were aberrant from that of Put at early stage. Expressions of five key genes involved in polyamine biosynthesis were characterized, in which only the genes leading to Put synthesis, ADC (arginine decarboxylase) and ODC (ornithine decarboxylase), agreed with callus growth and fluctuation of Put titers. Treatment of the callus with D-arginine, an inhibitor of ADC, led to significant growth inhibition and enormous reduction of endogenous Put, coupled with obvious decrease of mRNA levels of ADC and ODC. Exogenous application of Put partially restored the callus growth, along with resumption of endogenous Put and expression levels of ADC and ODC. Spd and Spm titers experienced minor change in comparison to Put. The data presented here suggested that free Put played an important part in peach callus growth. Putative mechanisms or mode of action underlying the role of Put in peach callus growth and different expression patterns of the genes responsible for polyamine biosynthesis are also discussed.

Computational evaluation of the roles of Na+ current, iNa, and cell death in cardiac pacemaking and driving

Voltage-dependent sodium (Na+) channels are heterogeneously distributed through the pacemaker of the heart, the sinoatrial node (SA node). The measured sodium channel current ( iNa) density is higher in the periphery but low or zero in the center of the SA node. The functional roles of iNa in initiation and conduction of cardiac pacemaker activity remain uncertain. We evaluated the functional roles of iNa by computer modeling. A gradient model of the intact SA node and atrium of the rabbit heart was developed that incorporates both heterogeneities of the SA node electrophysiology and histological structure. Our computations show that a large iNa in the periphery helps the SA node to drive the atrial muscle. Removal iNa from the SA node slows down the pacemaking rate and increases the sinoatrial node-atrium conduction time. In some cases, reduction of the SA node iNa results in impairment of impulse initiation and conduction that leads to the SA node-atrium conduction exit block. Decrease in active SA node cell population has similar effects. Combined actions of reduced cell population and removal of iNa from the SA node have greater impacts on weakening the ability of the SA node to pace and drive the atrium.

Isolation of cytoplasts from Satsuma mandarin (Citrus unshiu Marc.) and production of alloplasmic hybrid calluses via cytoplast-protoplast fusion

Cytoplasm of Satsuma mandarin (Citrus unshiu Marc.) is known to influence seedlessness. Transfer of cytoplasm to a seedy cultivar could possibly lead to the production of seedless citrus fruits. In the present paper cytoplasts were isolated from cell suspension-derived protoplasts of Satsuma mandarin via ultra-centrifugation in a discontinuous gradient. No nucleus could be detected in the cytoplasts by DAPI (4', 6-diamidino-2-phenylindole) staining compared with normal protoplasts. The cytoplasts, with high viability and small size, did not divide during solid embedding culture. Cytoplasts of Satsuma mandarin were electrically fused with embryogenic protoplasts of Murcott tangor (C. reticulata x C. sinensis), which led to regeneration of several cell lines. Flow cytometry (FCM) indicated that the cell lines were diploids. Simple sequence repeats (SSR) and cleaved amplified polymorphism sequence (CAPS) showed that the cell lines got their nuclear DNA from the protoplast parent, whereas the cytoplast parent donated the mtDNA, confirming transfer of mtDNA from Satsuma mandarin into Murcott tangor via cytoplast-protoplast fusion though no polymorphism was detected in chloroplast DNA between the fusion partners. This is the first report on isolation and characterization of cytoplasts, together with cytoplast-protoplast fusion in Citrus, which has a potential for citrus cultivar improvement involving cytoplasm transfer via cytoplast-protoplast fusion.

The effect of conjugated equine oestrogen on diabetes incidence: the Women's Health Initiative randomised trial

AIMS/HYPOTHESIS

Recent clinical trials have found that the combination of conjugated equine oestrogen (CEO) and medroxyprogesterone has a protective effect on the incidence of type 2 diabetes. To determine the effect of CEO alone on the incidence of diabetes mellitus in postmenopausal women, we analysed the results of the Women's Health Initiative oestrogen-alone trial.

METHODS

The Women's Health Initiative is a randomised, double-masked trial comparing the effect of daily 0.625 mg CEO with placebo during 7.1 years of follow-up of 10,739 postmenopausal women who were aged 50-79 years and had previously had a hysterectomy. Diabetes incidence was ascertained by self-report of treatment with insulin or oral hypoglycaemic medication. Fasting glucose, insulin and lipoproteins were measured in an 8.6% random sample of study participants, at baseline and at 1, 3 and 6 years.

RESULTS

The cumulative incidence of treated diabetes was 8.3% in the oestrogen-alone group and 9.3% in the placebo group (hazard ratio 0.88, 95% CI 0.77-1.01, p=0.072). During the first year of follow-up, a significant fall in insulin resistance (homeostasis model assessment of insulin resistance) in actively treated women compared with the control subjects (Year 1 baseline between-group difference -0.53) was seen. However, there was no difference in insulin resistance at the 3- or 6-year follow-up.

CONCLUSIONS/INTERPRETATION

Postmenopausal therapy with oestrogen alone may reduce the incidence of treated diabetes. The effect is smaller than that seen with oestrogen plus progestin. CEO should not, however, be used with the intention of preventing diabetes, as its well-described adverse effects preclude long-term use for primary prevention.

Preparation, characterization and nasal delivery of alpha-cobrotoxin-loaded poly(lactide-co-glycolide)/polyanhydride microspheres

In this study, alpha-cobrotoxin was incorporated into the microspheres composed of poly(lactide-co-glycolide) (PLGA) and poly[1,3-bis(p-carboxy-phenoxy) propane-co-p-(carboxyethylformamido) benzoic anhydride] (P(CPP:CEFB)) and intranasally delivered to model rats in order to improve its analgesic activity. The microspheres with high entrapment efficiency (>80%) and average diameter of about 25 microm could be prepared by a modified water-in-oil-in-oil (w/o/o) emulsion solvent evaporation method. Scanning electron micrograph (SEM) study indicated that P(CPP:CEFB) content played a considerable role on the morphology and degradation of the microspheres. The presence of P(CPP:CEFB) in the microspheres increased their residence time at the surface of the nasal rat mucosa. The toxicity of the composite microspheres to nasal mucosa was proved to be mild and reversible. A tail flick assay was used to evaluate the antinociceptive activity of the microspheres after nasal administration. Compared with the free alpha-cobrotoxin and PLGA microspheres, PLGA/P(CPP:CEFB) microspheres showed an apparent increase in the strength and duration of the antinociceptive effect at the same dose of alpha-cobrotoxin (80 microg/kg body weight).

In vitro and in vivo studies of cyclosporin A-loaded microspheres based on copolymers of lactide and ɛ-caprolactone: Comparison with conventional PLGA microspheres

A hydrophobic peptide, cyclosporin A (CyA), was incorporated in microspheres based on poly(lactide-b-epsilon-caprolactone) (P(LA-b-CL), LA/CL (in molar ratio): 78.7/21.3 and 48.1/51.9) and poly(lactide-co-glycolide) (PLGA, LA/GA: 80/20) using oil-in-water (O/W) emulsion solvent evaporation method. The microspheres were characterized by SEM, DSC and X-ray diffraction, and CyA release rate was determined by HPLC. It was revealed that CyA can be efficiently loaded into all the microspheres (exceed 96%). Compared to PLGA microspheres, P(LA-b-CL) microspheres liberated CyA more rapidly. Within the first day, about 75, 50 and 12% of CyA released from P(LA-b-CL) (48.1/51.9), P(LA-b-CL) (78.7/21.3) and PLGA microspheres, respectively, which can be attributed to the partial crystallization occurring in P(LA-b-CL) microspheres. CyA levels in whole blood were also tested. In comparison with PLGA microspheres, P(LA-b-CL) microspheres provided a higher blood level of CyA. The maximum CyA concentration in whole blood (approximately 520, 450 and 400 ng ml(-1) for P(LA-b-CL) (48.1/51.9) P(LA-b-CL) (78.7/21.3) and PLGA microspheres, respectively) was reached at the second day post administration. And then P(LA-b-CL) microspheres showed a constant CyA level (about 100-200 ng ml(-1)) for extended periods of time (several weeks). Such CyA-loaded P(LA-b-CL) microspheres displaying higher CyA concentration during the first few days and similar constant blood CyA level thereafter showed more advantages than those prepared with PLGA and could meet clinical needs more efficiently.

Relatively favorable outcomes of post-transplant pulmonary function in patients with chronic myeloid leukemia receiving non-myeloablative allogeneic hematopoietic stem cell transplantation

Pulmonary function tests were performed in 20 patients with chronic myeloid leukemia before and after human leukocyte antigen-matched allogeneic sibling hematopoietic stem cell transplantation (HSCT) to identify any conditioning treatment effects on post-transplant function from January 1995 to December 2002. Of 20 patients, eight received non-myeloablative conditioning treatment and 12 received conventional myeloablative conditioning treatment. Pulmonary function tests including forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and diffusion capacity for carbon monoxide (DLCO) were performed pretransplant, 6 and 12 months post-transplant. Possible pre-HSCT and post-HSCT risk factors were evaluated for association with pulmonary function. The results showed that myeloablative conditioning treatment had greater negative impact on FEV1, FVC, and DLCO than non-myeloablative conditioning therapy. We conclude that non-myeloablative allogeneic HSCT may apply a better transplant choice in patients who need special concern with post-transplant pulmonary function changes.

Biomonitoring of heavy metals and trace organics using the intertidal mussel Perna viridis in Hong Kong coastal waters

This paper presents the results of a 6-year (1998-2003) survey of trace toxics in the intertidal mussel Perna viridis conducted by the Hong Kong Environmental Protection Department. Concentrations of heavy metals and trace organics were measured in the soft bodies of P. viridis collected from five sites in Hong Kong waters, i.e. Wu Kai Sha (Tolo Harbour), Ma Wan (Northwest), Tsim Sha Tsui (Victoria Harbour), Tai Tam (Hong Kong South) and Lamma Island (Southern Waters) in order to establish the spatial patterns of contaminants in mussels. Among the metals analysed, Cd showed a significant concentration gradient in Hong Kong waters. The levels of Cd in P. viridis were significantly higher at Ma Wan as compared to the other sites studied. Ma Wan also had relatively higher concentrations of Pb. Mn concentrations were particularly prominent at Wu Kai Sha. Significantly higher concentrations of Hg and Cu were recorded at Tai Tam and Tsim Sha Tsui. Tai Tam and Wu Kai Sha had higher levels of V; whereas higher Ni concentrations were recorded at Lamma Island and Tai Tam. No clear spatial patterns for Al, As, Cr, Fe and Zn were observed. Higher concentrations of PAHs in P. viridis were observed around urban centres impacted by sewage discharges (e.g. Tsim Sha Tsui); whereas higher PCB levels were found not only in Tsim Sha Tsui but also in less urbanised areas such as Lamma Island and Tai Tam, suggesting that these may be due to non-sewage related inputs. The study also shows that Northwest and Southern waters are subject to a higher degree of DDT pollution compared with other sites. Of the 17 dioxin compounds analysed, positive data were mostly recorded for two compounds which are of low toxicity (i.e. OCDD and 1,2,3,4,6,7,8-HpCDD) whereas the most toxic congeners (i.e. 2,3,7,8-TCDD and 1,2,3,7,8-PeCDD) were not detected in the 6 years of monitoring. In general, the levels of OCDD in P. viridis were found to be higher in Tai Tam and Lamma Island in Southern Waters of Hong Kong. This study found that the levels of some highly toxic heavy metals (i.e. Cd, Hg and Pb) in the mussel P. viridis did not exceed the recommended limits for shellfish as food in Hong Kong (i.e. Cd: 2.0 ppm; Hg: 0.5 ppm; Pb: 6.0 ppm wet weight). The levels of As and Ni in P. viridis were also well below the action limits set by the US FDA (i.e. As: 86 ppm; Ni: 80 ppm wet weight). DDT and PCB contaminations in P. viridis were below the concentrations of concern. Compared with data obtained in the 1980s, the current levels of DDTs in P. viridis were 4-16 times lower; whereas Pb concentrations recorded in Tsim Sha Tsui have also been lowered significantly. This is mainly related to reduction in local and regional pollution sources in the past 20 years.

Angular distributions for (3,4)(Lambda)H bound states in the (3,4)He(e,e(')K+) reaction

The (3,4)(Lambda)H and (4)(Lambda)H hypernuclear bound states have been observed for the first time in kaon electroproduction on (3,4)He targets. The production cross sections have been determined at Q(2)=0.35 GeV2 and W=1.91 GeV. For either hypernucleus the nuclear form factor is determined by comparing the angular distribution of the (3,4)He(e,e(')K+)(3,4)(Lambda)H processes to the elementary cross section 1H(e,e K+)Lambda on the free proton, measured during the same experiment.

The Impact of Visual Impairment and Use of Eye Services on Health-Related Quality of Life among the Elderly in Taiwan: The Shihpai Eye Study

To evaluate the effect of impaired vision on health-related quality of life (HRQoL), the authors administered the Medical Outcomes Survey Short-Form 36 (SF-36) to the elderly in a metropolitan Taiwanese community and assessed their visual impairment status. A structured questionnaire was used for door-to-door data collection. Interviewers also collected information on demographics, medical history, and HRQoL. Those who were interviewed were invited to the study hospital for a detailed eye examination. An eye examination, including presenting visual acuity and best-corrected visual acuity, was conducted by ophthalmologists. Presenting visual acuity and best-corrected visual acuity were measured in the better eye. Impaired vision was defined as presenting visual acuity in the better-seeing eye worse than 6/12 (or 20/40) and was used to evaluate the correlation to HRQoL. A total of 1361 subjects at least 65 years of age participated in both the interview and eye examination. Internal-consistency and test-retest reliability of the eight scales were high. Based on the separate multiple regression model, after controlling for all other covariates, subjects in contact with vision services offered by an ophthalmologist had more positive scores on general health perceptions (beta = 4.29; p < 0.001), vitality/energy (beta = 2.73; p < 0.001), and mental health (beta = 2.06; p = 0.01). Impaired vision was associated with significantly lower scores in physical functioning (beta = -3.62; p < 0.001) and social functioning scales (beta = -3.25; p = 0.015). The findings suggest that visual impairment is associated with lower quality of life and use of eye care services is associated with higher quality of life.

Identification of phase I and phase II metabolites of Guanfu base A hydrochloride in human urine

Guanfu base A is a novel arrhythmic drug candidate isolated from the tuber of a traditional Chinese herb. Phase I and Phase II metabolites of Guanfu base A (GFA) Hydrochloride were studied in human urine by means of liquid chromatography mass spectrometry (LC/MSD) and tandem mass spectrometry (MS/MS). For phase I metabolites, Guanfu base I (GFI) was separated by HPLC and identified by comparison with authentic reference for their retention times, molecular ion peaks, fragment ions, and UV spectra. GFA oxide was also indicated to exist in human urine. For phase II metabolites, after human urine was treated either with glucuronidase or sulfatase, GFA occured in the chromatograms. It was suggested that there were GFA glucuronide and GFA sulfate in human urine. Further more, positive molecular ions, m/z 606 and m/z 510, of the two conjugates were detected in human urine by LC/MSD. In addition, characteristic ion of m/z 606 was identified as the precursor ion of m/z 177 [Glucuronic acid+H]+ by using MS/MS. Characteristic ion of m/z 430 [GFA+H]+ was also identified as a product ion of m/z 606 [GFA glucuronide+H]+. It was concluded that there were GFI. GFA oxide, GFA glucuronide and GFA sulfate in human urine.

Hydrogen peroxide-induced apoptosis in pc12 cells and the protective effect of puerarin

In this study, the effect of puerarin on hydrogen peroxide-induced apoptosis in PC12 cells was studied. Exposure of cells to 0.5mM H(2)O(2)may cause significant viability loss and apoptotic rate increase. When c-Myc, Bcl-2 and Bax expression and caspase-3 activity were measured, using Ac-DEVD-AMC as a substrate, the changes in these apoptosis regulatory and effector proteins suggested that the elevation of c-Myc, decrease in Bcl-2:Bax protein ratio, and caspase-3 activation all play a key role in apoptosis. When cells were treated with puerarin prior to 0.5 mM H(2)O(2)treatment, a reduction in viability loss and apoptotic rate was seen. In addition, c-Myc expression decreased and Bcl-2:Bax ratio increased. Puerarin also reduced the H(2)O(2)-induced elevation of caspase-3 activation. These results suggest that puerarin can protect neurons against oxidative stress. It can block apoptosis in its early stages via the regulation of anti- and pro-apoptotic proteins, as well as by the attenuation of caspase-3 activation in H(2)O(2)-induced PC12 cells.

Catalpol inhibits apoptosis in hydrogen peroxide-induced PC12 cells by preventing cytochrome c release and inactivating of caspase cascade

In the present study, using a rat pheochromocytoma (PC12) cell line, the effect of catalpol on H2O2-induced apoptosis was studied. The apoptosis in H2O2-induced PC12 cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, the release of mitochondrial cytochrome c to cytosol and sequential activation of caspase-1 and caspase-3 then leading to cleavage of poly-ADP-ribose polymerase (PARP). Catalpol not only suppressed the down-regulation of Bcl-2, up-regulation of Bax and the release of mitochondrial cytochrome c to cytosol, but also attenuated caspase-3 activation, PARP cleavage, and eventually protected against H2O2-induced apoptosis. Taken together, these results suggest that treatment of PC12 cells with catalpol can block H2O2-induced apoptosis by the regulation of Bcl-2 family members, as well as suppression of cytochrome c release and caspase cascade activation.

Relief of acute low back pain with diclofenac-K 12.5 mg tablets: a flexible dose, ibuprofen 200 mg and placebo-controlled clinical trial

OBJECTIVE

To assess efficacy and safety of diclofenac-K 12.5 mg tablets in the treatment of acute low back pain (low back pain).

MATERIAL/METHOD

A multiple dose, double-blind, double-dummy, randomized, placebo-controlled, parallel group trial compared diclofenac-K (12.5 mg; n = 124) with ibuprofen (200 mg; n = 122) and placebo (n = 126) in patients with moderate-to-severe acute low back pain. The treatment consisted of an initial dose of 2 tablets followed by 1 or 2 tablets every 4-6 hours as needed (maximum 6 tablets/day) for 7 days. The primary efficacy outcome for the initial dose was TOTPAR-3, the summed total pain relief over the first 3 hours. Secondary initial dose outcomes included TOTPAR-6, summed pain intensity differences SPID-3 and SPID-6, time to rescue medication or remedicate, and the End of First Dose global efficacy assessment. The primary efficacy outcome for the flexible multiple dosing regimen was the End of Study global efficacy assessment. Secondary outcomes for multiple dosing included time to rescue medication over the entire study, the End of Day global efficacy assessments (daily over Days 1-7), pain intensity differences on the VAS measured at Visit 2 and 3, and change in Eifel algofunctional index. Safety/tolerability was assessed by recording adverse events.

RESULTS

Diclofenac-K 12.5 mg demonstrated superiority vs placebo on the primary efficacy parameter and almost all secondary initial dose outcomes. With respect to the initial dose, diclofenac-K 12.5 mg was also significantly superior to ibuprofen 200 mg on SPID-3. Ibuprofen 200 mg was superior to placebo only on the End of First Dose global efficacy assessment. The flexible multiple dosing regimens of diclofenac-K and ibuprofen were both significantly superior to placebo on the End of Study global efficacy assessment, time to rescue medication over the entire study period, the End of Day global efficacy assessment on Days 1-2, pain intensity difference on the VAS at Visit 3 and the Eifel algofunctional index at Visit 3 (also at Visit 2 in diclofenac-K 12.5 mg group). Both active treatments were as well tolerated as placebo.

CONCLUSIONS

The flexible multiple dosing regimen of diclofenac-K 12.5 mg (initial dose of 2 tablets followed by 1-2 tablets every 4-6 hours, max. 75 mg/day) is an effective and safe treatment of acute low back pain.

Study of a mathematical model of metal ion complexes in solvent sublation

Separation of metal ion complex, [(C(12)H(8)N(2))(3)Fe(2+)], with surfactant sodium dodecylphrate (DLS) complex from aqueous phase was carried out by solvent sublation, which obeys first-order kinetics. On the base of the complete transport mechanisms, the Langmuir adsorption, and the ion complex equilibrium in the aqueous phase, a mathematical model for the [(C(12)H(8)N(2))(3)Fe(2+)]-surfactant ion complex is obtained with the aid of the Mathematic 4.0 program, 4th Runge-Kutta method, and the Matlab programs. The effects of many parameters, such as K(a), K(l), K(ow), d(i), V(o), V(w), and Q(a), on solvent sublation are investigated. Furthermore, the simulation showed that the model is substantiated for experiments on the solvent sublation of the complex.

High resolution spectroscopy of the 12Lambda B hypernucleus produced by the (e,e'K+) reaction

High-energy, cw electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the potential of the (e,e'K+) reaction for hypernuclear spectroscopy. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed energy resolution was found to be approximately 900 keV for the (12)(Lambda)B spectrum, and is substantially better than any previous hypernuclear experiment using magnetic spectrometers. The positions of the major excitations are found to be in agreement with a theoretical prediction and with a previous binding energy measurement, but additional structure is also observed in the core excited region, underlining the future promise of this technique.

Design of a computerized system for the retrospective analysis by the physician of his own drug prescriptions

The quality of drug prescription is known to be poor in many medical domains. Feedback information may help the physician to improve this component of his medical activity. The increasing use of computerized drug prescription systems makes possible the retrospective processing of prescriptions made over a given time period. This paper describes the design of a computerized system for providing feedback information to the physician about the quality of his drug prescribing activity. It is designed to be used by the physician himself. The analysis is based on two groups of quantitative indicators, simple and composite. The constraints that must be satisfied to calculate these indices automatically are given. They are related to the coding systems used for drug prescription, knowledge on drugs and patient data. The system design is based on modeling according to UML formalism. We give also a concrete view of the main functions of the system, based on a pictorial illustration with a component of the user interface. Some limitations and the possible extensions of this system for analyzing simultaneously the prescriptions made by set of physicians are discussed.

Comparative genomic hybridization of esophageal squamous cell carcinoma: correlations between chromosomal aberrations and disease progression/prognosis

BACKGROUND

Esophageal carcinoma is a major cause of cancer-related deaths among males in Taiwan. However, to date, the genetic alterations that accompany this lethal disease are not understood.

METHODS

Chromosomal aberrations of 46 samples of esophageal squamous cell carcinoma (EC-SCC) were analyzed by comparative genomic hybridization (CGH), and their correlations with pathologic staging and prognosis were analyzed statistically.

RESULTS

In total, 321 gains and 252 losses were found in 46 tumor samples; thus, the average gains and losses per patient were 6.98 and 5.47, respectively. Frequent gain abnormalities were found on chromosome arms 1q, 2q, 3q, 5p, 7p, 7q, 8q, 11q, 12p, 12q, 14q, 17q, 20q, and Xq. Frequent deletions were found on chromosome arms 1p, 3p, 4p, 5q, 8p, 9p, 9q, 11q, 13q, 16p, 17p, 18q, 19p, and 19q. It was found that deletions of 4p and 13q12-q14 and gain of 5p were significantly correlated with pathologic staging. Losses of 8p22-pter and 9p also were found more frequently in patients with advanced disease. Gain of 8q24-qter was seen more frequently in patients with Grade 3 tumors. A univariate analysis found that pathologic staging; gains of 5p and 7q; and deletions of 4p, 9p, and 11q were significant prognostic factors. However, pathologic staging became the only significant factor in a multivariate analysis.

CONCLUSIONS

CGH not only revealed novel chromosomal aberrations in EC-SCC, but also found possible genotypic changes associated with disease progression. Despite all of the possible associations of chromosomal aberrations with disease progression, the most important prognostic factor for patients with EC-SCC was pathologic staging.

Visual impairment in a Taiwanese population: prevalence, causes, and socioeconomic factors

PURPOSE

We sought to estimate the prevalence of visual impairment among an elderly population in urban Taiwan, determine the causes of visual impairment, and gain information about certain socioeconomic factors associated with visual impairment.

METHODS

A population-based survey of ocular diseases in residents aged 50 years or older was conducted in Peitou Precinct, Taipei, Taiwan. All participants underwent a comprehensive ophthalmic examination, including visual acuity measurement, using standardized protocols. Demographic data, marital status, employment status, and educational level were gathered through an interview.

RESULTS

A total of 2034 participants completed the visual acuity measurements. The prevalence of visual impairment (defined as best-corrected visual acuity in the better eye <6/18) among this population was 2.75% (95% confidence intervals: 2.04%-3.46%). Three major causes of visual impairment were cataract (30.4%), high myopic macular degeneration (25.0%), and age-related macular degeneration (14.3%). In multivariate analysis, age was positively correlated with visual impairment (P < 0.001), and higher education level was associated with a significant decrease in the odds of being visually impaired (P < 0.001). No relation was found between visual impairment and sex, or marital and employment status. CONCLUSIONS This study provides the first information about the prevalence and causes of visual impairment in Taiwan, and identifies age and educational level as the most important factors related to visual impairment. Additional educational programs should be developed to improve individual awareness of age-related ocular diseases and the availability of current ophthalmic intervention.

Pulsatile ocular blood flow in asymmetric exudative age related macular degeneration

BACKGROUND/AIMS

Decreased perfusion or increased vascular resistance of the choroidal vessels had been proposed as the vascular pathogenesis for age related macular degeneration (AMD). This study planned to answer the question whether pulsatile ocular blood flow (POBF) was different in patients with asymmetric exudative AMD between eyes with drusen, choroidal neovascularisation (CNV), or disciform scar.

METHODS

37 patients with asymmetric exudative AMD were enrolled in this observational case series study. POBF were measured in both eyes of each subject. Eyes with high myopia, anisometropia, recent laser treatment, and glaucoma were excluded.

RESULTS

After adjusting for ocular perfusion pressure, intraocular pressure, and pulse rate, multivariate regression analysis with generalised estimating equation showed POBF was significantly higher in eyes with CNV (1217 (SD 476) microl/min) than the contralateral eyes with drusen (1028 (385) microl/min) (p = 0.024). Eyes with disciform scar had lower POBF than the contralateral eyes with drusen (999 (262) microl/min and 1278 (341) microl/min, respectively, p<0.001). There was no significant correlation between the POBF and the lesion size of the CNV.

CONCLUSION

The POBF in eyes with drusen was lower than their fellow eyes with CNV, but higher than their fellow eyes with disciform scar. This finding suggests that haemodynamic differences between fellow eyes in individuals are relevant to the development of CNV and the formation of disciform scar. Further studies on the follow up patients might shed light on the pathogenesis of exudative AMD.

Relapse of Graves' disease after successful allogeneic bone marrow transplantation

As shown in many reports, allogeneic BMT can help cure autoimmune diseases. Conversely, we present a 24-year-old woman with Graves' disease, which was diagnosed just before BMT for CML. The Graves' disease remitted immediately after BMT but relapsed 18 months later. Since the donor was free from thyroid diseases and the patient showed a rapid shift to complete donor chimerism after BMT, the autoimmune problem seemed neither to arise directly from the donor nor simply from the recipient's residual lymphocytes. On the contrary, it was most likely compounded by chronic GVHD as suggested by the accompanying GVHD symptoms and the absolute donor karyotype in bone marrow cells. A Graves' disease-susceptible HLA allele was also shared between recipient and donor, possibly enhancing the chances of this condition developing. Thus, allogeneic BMT may facilitate relapses in autoimmune diseases as well as alleviating them.

Comparative genomic hybridization of esophageal squamous cell carcinoma: correlations between chromosomal aberrations and disease progression/prognosis

BACKGROUND

Esophageal carcinoma is a major cause of cancer-related deaths among males in Taiwan. However, to date, the genetic alterations that accompany this lethal disease are not understood.

METHODS

Chromosomal aberrations of 46 samples of esophageal squamous cell carcinoma (EC-SCC) were analyzed by comparative genomic hybridization (CGH), and their correlations with pathologic staging and prognosis were analyzed statistically.

RESULTS

In total, 321 gains and 252 losses were found in 46 tumor samples; thus, the average gains and losses per patient were 6.98 and 5.47, respectively. Frequent gain abnormalities were found on chromosome arms 1q, 2q, 3q, 5p, 7p, 7q, 8q, 11q, 12p, 12q, 14q, 17q, 20q, and Xq. Frequent deletions were found on chromosome arms 1p, 3p, 4p, 5q, 8p, 9p, 9q, 11q, 13q, 16p, 17p, 18q, 19p, and 19q. It was found that deletions of 4p and 13q12-q14 and gain of 5p were significantly correlated with pathologic staging. Losses of 8p22-pter and 9p also were found more frequently in patients with advanced disease. Gain of 8q24-qter was seen more frequently in patients with Grade 3 tumors. A univariate analysis found that pathologic staging; gains of 5p and 7q; and deletions of 4p, 9p, and 11q were significant prognostic factors. However, pathologic staging became the only significant factor in a multivariate analysis.

CONCLUSIONS

CGH not only revealed novel chromosomal aberrations in EC-SCC, but also found possible genotypic changes associated with disease progression. Despite all of the possible associations of chromosomal aberrations with disease progression, the most important prognostic factor for patients with EC-SCC was pathologic staging.

Retinopathy of prematurity: screening, incidence and risk factors analysis

BACKGROUND

The sequela of retinopathy of prematurity (ROP) is an important cause of infant blindness. This study was designed to screen the high-risk premature infants and investigate the incidence and risk factors associated with the development of ROP.

METHODS

From October 1997 to October 1998, all premature infants with birth body weight (BBW) less than 2000 gm or gestational age (GA) less than 36 weeks were enrolled and underwent ophthalmologic examination at 4 to 6 weeks of age at Taipei Veterans General Hospital. The perinatal variables were analyzed to evaluate their correlation with the development of ROP.

RESULTS

In totally 108 premature infants, the incidence for development of ROP was 25% (27 in 108 patients). The threshold ROP occurred in 15 eyes (7%). The average BBW and GA (1267+/-341 gm and 29.7+/-2.7 weeks) were significantly lower in ROP group than in the non-ROP group (1703+/-368 gm and 32.3+/-2.2 weeks). The artificial ventilation for more than 5 days, chronic lung disease and periventricular leukomalacia were significant risk factors associated with highest rate of ROP. The respiratory distress syndrome, intraventricular hemorrhage, congenital heart disease and sepsis were significant risk factors accompanied by moderate rate of ROP.

CONCLUSION

Low birth body weight and young gestational age are the most important risk factors in the development of ROP. The analysis of risk factors will be helpful in understanding and prediction of ROP formation in high-risk neonates. The timely clinical screening retina examination of high-risk premature infants is important to prevent the development of advanced ROP.

Crystallization and preliminary X-ray diffraction analysis of cytotoxic ribonucleases from bullfrog Rana catesbeiana

RC-RNases are ribonucleases from Rana catesbeiana oocytes with pyrimidine-guanine sequence specificity. They also possess cell cytotoxicity and lectin activity. Protein crystals of three RC-RNase isozymes, RC-RNase 3, RC-RNase 4 and RC-RNase 6, were grown in various crystal systems under different conditions. Crystals of RC-RNase3 belong to the orthorhombic C222(1) space group, with unit-cell parameters a = 66.66, b = 97.38, c = 85.74 A. Crystals of RC-RNase 4 belong to the trigonal space group P3(1) or P3(2), with unit-cell parameters a = b = 32.22, c = 92.12 A. Crystals of RC-RNase 6 complexed with cytidylyl 2'-5' guanosine belong to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 61.80, c = 65.96 A.

Are women occupying positions of power online? Demographics of chat room operators

Internet statistics indicate a reduction in the gender discrepancy online. Yet, what is the situation within specific online communities like Internet Relay Chat (IRC)? Likewise, what is the gender status of those occupying positions of power online? An exploratory study of chat room operators (those who govern chat rooms) was conducted to investigate gender differences in operator's demographic characteristics and IRC experience. Whether those less satisfied with their real-life occupation were attracted to chat room operator positions was also investigated. A survey of 423 chat room operators was administered, comprising 25% women. Real-life occupations of chat room operators covered a broad spectrum, from professional and managerial to service, sales, and production workers, as well as those not employed. The most common occupational category cited was student, with very similar proportions of men and women occupying high-status positions. Of the occupations listed, 23% fell within the IT industry, with significantly more male than female operators working in this area. Majorities of both genders were satisfied with their real-life occupation. There was no relationship between job satisfaction and IRC experience or time spent as chat room operator. There were no gender differences for IRC experience. Majorities of both genders had been using IRC for 1 to 3 years or more, used IRC daily, and spent most or all of their time on IRC as operators. Ages ranged from 11 to 66 years, with the mean age 25 years. Women were significantly older than men. A significant proportion of men and women were from North America.

Up-regulation of Fas ligand expression by human cytomegalovirus immediate-early gene product 2: a novel mechanism in cytomegalovirus-induced apoptosis in human retina

Human CMV (HCMV) is an important pathogen that causes widespread diseases in immunocompromised individuals. Among the opportunistic HCMV infections, HCMV retinitis is most common in transplant recipients and AIDS patients. It often leads to blindness if left untreated. The question as to how HCMV infection causes retinal pathogenesis remains unresolved. Here, we report that viral immediate-early gene product 2 (IE2), but not IE1, up-regulates the Fas ligand (FasL) expression in HCMV-infected human retinal pigment epithelium cells. Increased secretion of FasL from virally infected cells into cultured medium was observed upon HCMV infection. The capability of such cell-free medium to induce apoptosis of Fas (CD95)-expressing Jurkat cells further implies that Fas-FasL interaction might mediate cell death in the lesion of HCMV retinitis. To support this idea, we observed augmented soluble FasL levels in vitreous from AIDS patients with HCMV retinitis as compared with that from AIDS patients without HCMV infection. In addition, by in situ hybridization and immunohistochemistry, we detected enhanced signals of FasL, the existence of viral IE Ags and apoptotic cells at the same sites in the lesion of HCMV-infected retina. These results strongly suggest that IE2 induction of FasL expression in human retina might be an important event that takes place in the early stage of infection and finally leads to visual loss in individuals affiliated with HCMV retinitis.

Salvage therapy with single-agent paclitaxel by three-hour infusion in metastatic breast cancer: an experience in Taipei Veterans General Hospital

BACKGROUND

Paclitaxel is an active agent in the treatment of breast, ovarian, lung and head and neck cancers. In previous phase I and II trials, it exerted novel cytotoxic effect on several malignancies. Various doses and regimens of paclitaxel have been assessed in metastatic breast cancer, with responses between 20 and 62%. However, combination therapy with other anti-cancer drugs leads to a high incidence of side effects. Our aim was to evaluate the efficacy of paclitaxel given by 3 h infusion as salvage chemotherapy for patients with metastatic breast cancer.

METHODS

Between May 1999 and April 2000, 14 women with metastatic breast cancer were enrolled in this study and all the patients had to have measurable lesions. The median age of the patients was 48.7 years (range 39-56 years). All of them were definitely evidenced as having metastatic breast cancer and received complete courses of anthracycline-containing agents before applying paclitaxel. The protocol was single-agent paclitaxel (Anzatax, Faulding, Australia) at a moderate dosage of 175 mg/m(2) by 3 h intravenous infusion every 3 weeks.

RESULTS

A total of 75 cycles were administered to these 14 patients with a median of four delivered cycles (range 3-14) and the response rate was 28.6% (95% CI: 21-40%), including four partial remission, three stable disease and seven progressive disease. The median time to progression was 3 (range 3-7) months. Hematological toxicities were minimal with no evidence of severe (grade 3 or 4) leukopenia and thrombocytopenia. Hepatic toxicities were observed in 12 cycles with five in grade 3.

CONCLUSIONS

Our study indicates that utilizing single-agent paclitaxel exerts moderate activity on anthracycline-refractory metastatic breast cancer patients without excessive toxicities.

Posttonsillectomy hemorrhage: what is it and what should be recorded?

OBJECTIVES

To report on our incidence of posttonsillectomy hemorrhage and to define what constituted posttonsillectomy bleeding.

DESIGN

Retrospective study.

SETTING

Tertiary care children's hospital and a local satellite facility.

PATIENTS

A series of 1438 consecutive patients who had undergone either tonsillectomy or adenotonsillectomy between January 1, 1999, and December 31, 1999.

INTERVENTION

During this period, parents were instructed to return with their children for clinical evaluation if any blood was seen in the postoperative period.

MAIN OUTCOME MEASURES

Postoperative day of evaluation, age, sex, location of bleeding, management strategy, length of hospital admission, and any bleeding disorders were noted for each patient.

RESULTS

A total of 112 patients underwent evaluation 134 times. Of these patients, 96 required only 1 evaluation and 16 required more than 1 evaluation. All patients who had more than 1 evaluation required intervention. The total number of children requiring intervention for posttonsillectomy hemorrhage was 51 (3.5%) of the 1438 patients. Female patients were more likely than male patients to return for evaluation. Patients who were 12 years and older were the most likely and those 3 years and younger were the least likely to have posttonsillectomy hemorrhage. The most common time from surgery to initial evaluation for hemorrhage was 6 days.

CONCLUSIONS

By reviewing our own criteria for defining and recording posttonsillectomy hemorrhage, we conclude that posttonsillectomy hemorrhage is defined differently in the literature. This supports the need for a standard definition to allow for direct comparisons.

Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule

The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A(k) class II MHC molecule with associated peptide (pMHCII) shows that only the "top corner" of the CD4 molecule directly contacts pMHCII. The CD4 Phe-43 side chain extends into a hydrophobic concavity formed by MHC residues from both alpha 2 and beta 2 domains. A ternary model of the CD4-pMHCII-T-cell receptor (TCR) reveals that the complex appears V-shaped with the membrane-proximal pMHCII at the apex. This configuration excludes a direct TCR-CD4 interaction and suggests how TCR and CD4 signaling is coordinated around the antigenic pMHCII complex. Human CD4 binds to HIV gp120 in a manner strikingly similar to the way in which CD4 interacts with pMHCII. Additional contacts between gp120 and CD4 give the CD4-gp120 complex a greater affinity. Thus, ligation of the viral envelope glycoprotein to CD4 occludes the pMHCII-binding site on CD4, contributing to immunodeficiency.

Dietary inclusion of whole soy foods results in significant reductions in clinical risk factors for osteoporosis and cardiovascular disease in normal postmenopausal women

OBJECTIVE

To determine the effects of dietary inclusion of soy foods on clinical markers for cardiovascular disease (CVD) and osteoporosis in normal postmenopausal women.

DESIGN

This was a single open-group prospective clinical intervention. Forty-two normal postmenopausal women consumed three daily servings for 12 consecutive weeks of whole soy foods containing approximately 60 mg/d of isoflavones. Blood and urine specimens were obtained at baseline and after 12 weeks of dietary intervention.

RESULTS

Serum and urine levels of individual and total isoflavones increased significantly (7-19 fold, p < 0.001) from baseline. A significant increase (9.3%, p < 0.05) in the mean lag-time of low-density lipoprotein cholesterol oxidation was seen and was positively correlated with serum phytoestrogens (p < 0.05). Significant increases were found in mean levels of high-density lipoprotein cholesterol (HDLc) (3.7%, p < 0.05) and serum osteocalcin (10.2%, p < 0.025). Significant decreases were observed in total cholesterol:HDLc ratios (5.5%, p < 0.006) and mean urinary N-telopeptide excretion (13.9%, p < 0.02). Urinary excretion of total isoflavones was negatively correlated with very-low-density lipoprotein cholesterol, triglycerides, and total cholesterol:HDLc ratios (p < 0.04). No significant changes from baseline in HDLc peroxidation, total cholesterol, triglycerides, low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, bone-specific alkaline phosphatase, follicle-stimulating hormone, or estradiol levels were observed.

CONCLUSIONS

Dietary inclusion of whole soy foods containing 60 mg/d of isoflavones results in significant serum levels of phytoestrogens and reductions in several key clinical risk factors for CVD and osteoporosis in normal postmenopausal women. Long-term, placebo-controlled clinical trials are needed to evaluate the effect of phytoestrogens on the clinical endpoints of CVD and osteoporosis in this population.

Clinicopathologic factors related to apoptosis in retinoblastoma

PURPOSE

To investigate the presence of apoptosis in retinoblastoma and its correlation with other pathologic and prognostic factors.

METHODS

The pathologic and admission records of 25 patients with a pathologically confirmed diagnosis of retinoblastoma were reviewed. TUNEL (TdT dUTP nick end labeling) staining was used to examine apoptosis in the pathologic slides of these 25 patients. The association between apoptosis and clinicopathologic factors was examined with chi-square, Fisher's exact, and Student's t tests.

RESULTS

Of the 25 specimens tested, 11 were TUNEL stain-positive for the presence of apoptotic cells. Apoptosis was found more frequently in younger patients and within rosettes, although these associations were not statistically significant. Apoptosis was not associated with tumor invasion or metastasis.

CONCLUSION

Apoptotic cells were found in 11 of 25 retinoblastoma specimens. Apoptosis tends to occur in young patients and be distributed within rosettes.

Color Doppler imaging study of retrobulbar hemodynamics in chronic angle-closure glaucoma

PURPOSE

To evaluate the retrobulbar hemodynamics in patients with chronic angle-closure glaucoma (CACG) by using color Doppler imaging (CDI) and to correlate the degree of glaucomatous visual field loss with the hemodynamic parameters.

DESIGN

Prospective case series.

PARTICIPANTS AND CONTROLS

Twenty-six Chinese patients with CACG and 26 age-matched and gender-matched normal subjects were recruited. All CACG patients had history of chronic intraocular pressure (IOP) elevation and asymmetric visual field defects between their fellow eyes. After receiving laser peripheral iridotomy and/or filtration surgery, all of them had bilateral medication-free controlled IOP before enrolling into the study.

METHODS

Each subject underwent CDI measurement in the central retinal artery (CRA) and the nasal and temporal short posterior ciliary arteries (PCA). Visual fields of the CACG patients were obtained with Humphrey 24-2 program. The visual field defects were scored with the Advanced Glaucoma Intervention Study (AGIS) system. For each CACG patient, the eye with lower AGIS score was defined as the better eye and the eye with higher score as the worse eye.

MAIN OUTCOME MEASURES

Peak-systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI) were determined.

RESULTS

The EDV in the CRA and the temporal PCA was decreased significantly (P = 0.041 and 0.023, respectively) in the worse eyes of CACG patients compared with those in the control eyes. The better eyes of CACG patients showed no significant change in hemodynamic parameters compared with the control eyes. While comparing the fellow eyes of CACG patients, the worse eyes had significantly lower EDV in the temporal PCA (P = 0.012) than the contralateral better eyes. In 11 CACG patients with a difference of at least 8 in AGIS visual field scores between their fellow eyes, the worse eyes had significantly lower EDV (P = 0.041) in the CRA and lower PSV (P = 0.018) and EDV (P = 0.018) in the temporal PCA compared with those in the contralateral eyes. In multivariate regression analysis, the AGIS scores were significantly correlated with the PSV in the CRA (P = 0.015) and with the EDV (P < 0.001) and RI (P = 0.027) in the temporal PCA in patients with CACG.

CONCLUSIONS

Patients with well-controlled CACG may have decreased retrobulbar blood flow velocities and increased vascular resistance in the CRA and temporal PCA. The degree of retrobulbar hemodynamic impairment was well correlated with the degree of glaucomatous visual field loss.

Efficient non-viral DNA-mediated gene transfer to human primary myoblasts using electroporation

Gene transfer of human primary myoblasts with various non-viral methods has been hampered by low yield of transfection. We report here an efficient, simple and reproducible non-viral DNA-mediated gene transfer procedure for transfecting human myoblasts. We found that electroporation promotes a highly efficient DNA uptake by human primary cultures of myogenic cells. Under optimal conditions, 60-70% of human myoblasts transfected with the enhanced green fluorescent gene expressed the enhanced green fluorescent protein. Electroporated myoblasts behaved normally as judged by their ability to synthesize and express developmentally regulated proteins and to undergo terminal differentiation, i.e. to fuse and form myotubes. We showed, in addition, that a subpopulation of cultured human myoblasts with self-renewing properties and equivalent to native muscle satellite cells were as efficiently transfected by electroporation as proliferating myoblasts. Thus, the development of gene therapies based on the engineering and transplantation of human myoblasts may greatly benefit from gene transfer by electroporation.

Non-penetrating trabeculectomy for open angle glaucoma

BACKGROUND

Non-penetrating trabeculectomy is used as the surgical intervention for open angle glaucoma. It has advantage of creating gradual filtration through the thin trabeculo-Descemet membrane to reduce markedly the postoperative complications typical for penetrating operation. We described our experience of the non-penetrating trabeculectomy for open angle glaucoma.

METHODS

This is a retrospective study of 28 eyes of 28 patients with primary open glaucoma (POAG). Non-penetrating trabeculectomy was performed by one surgeon from July 1998 to March 2000. Examinations were performed preoperatively and postoperatively in 1 and 7 days and 1, 3, 6, 12 and 21 months.

RESULTS

The mean follow-up was 12.5 +/- 6.3 months (S.D.). The mean preoperative intraocular pressure (IOP) was 27.8 +/- 6.7 mmHg. The mean postoperative IOP was 11.5 +/- 6.2 mmHg in 1 day and 15.7 +/- 5.8 mmHg in 1 week, and it remained stable in the following 12 months. IOP of 71.3% (20/28) of the eyes could be controlled below or equal to 21 mmHg with no or only topical antiglaucoma medication. There were only few postoperative complications.

CONCLUSIONS

Non-penetrating trabeculectomy is efficient in controlling intraocular pressure of open angle glaucoma. No entering the anterior chamber diminishes the postoperative complications typical of the penetrating trabeculectomy.

Aneurysmal bone cyst of the frontal sinus

Aneurysmal bone cysts are benign, vascular, cystic osseous tumors. Approximately 2% of all aneurysmal bone cysts are found in the head and neck region, with the most common site being the mandible. We report a case of an aneurysmal bone cyst arising from the frontal sinus in a pediatric patient. The diagnosis was suggested through various radiographic studies, with the final pathologic diagnosis confirmed after tumor excision. Complete en-bloc excision was performed by using a bifrontal craniotomy approach, with immediate reconstruction of the defect by using a split calvarial bone graft.