A randomized controlled phase II clinical trial comparing ONO-4053, a novel DP1 antagonist, with a leukotriene receptor antagonist pranlukast in patients with seasonal allergic rhinitis.

BACKGROUND: Prostaglandin D2 (PGD2 ) is primarily produced by mast cells and is contributing to the nasal symptoms including nasal obstruction and rhinorrhea. OBJECTIVE: This study aimed to evaluate the efficacy and safety of a novel PGD2 receptor 1 (DP1) antagonist, ONO-4053, in patients with seasonal allergic rhinitis (SAR). METHODS: This study was a multicenter, randomized, double-blind, parallel-group study of patients with SAR. Following a one-week period of placebo run-in, patients who met the study criteria were randomized to either the ONO-4053, leukotriene receptor antagonist pranlukast, or placebo group for a two-week treatment period. A total of 200 patients were planned to be randomly assigned to receive ONO-4053, pranlukast, or placebo in a 2:2:1 ratio. Nasal and eye symptoms were evaluated. RESULTS: Both ONO-4053 and pranlukast had higher efficacy than placebo on all nasal and eye symptoms. ONO-4053 outperformed pranlukast in a total of three nasal symptom scores (T3NSS) as well as in individual scores for sneezing, rhinorrhea, and nasal itching. For T3NSS, the Bayesian posterior probabilities that pranlukast was better than placebo and ONO-4053 was better than pranlukast were 70.0% and 81.6%, respectively, suggesting that ONO-4053 has a higher efficacy compared with pranlukast. There was no safety-related issue in this study. CONCLUSIONS: We demonstrated that the efficacy of ONO-4053 was greater than that of pranlukast with a similar safety profile. This study indicates the potential of ONO-4053 for use as a treatment for SAR (JapicCTI-142706).

Directional Migration of MDA-MB-231 Cells Under O2/pH Gradients.

We hypothesized that cancer cells actively migrate toward intratumor microvessels, guided by tissue gradients of metabolic substrates (such as O2) and/or metabolites (such as CO2/H+). To test this hypothesis, we developed an in vitro model in which cellular energy metabolism establishes gradients of O2/nutrient/metabolite in monolayer cells cultured in a conventional culture dish. When gradients of O2 ranging from 3% to ~0% were produced, MDA-MB-231 cells located at 300, 500 and 1500 µm downstream in the gradient demonstrated significant directional migrations (Rayleigh z test). We also found a similar directionality in cell migration at the same location even when the initial O2 level in the O2 gradient was raised from 3% to 21%. Interestingly, such directionalities were no longer demonstrated when the cell density was lowered from 1.8 × 106 to 0.9 × 106 cells/ml. In the former, the magnitude of the extracellular pH gradient in regions 300 and 500 µm downstream in the gradient was significantly larger. Thus, the direction of cell migrations appeared to depend on the gradient of extracellular pH rather than on O2.

Micron scale directional coupler as a transducer for biochemical sensing.

A microfabricated directional coupler (DC) was used for the detection of DNA conjugated with quantum dots. Output optical signals from DCs of a wide range of device lengths correspond well to theoretical and simulation results. Even 20 µm-long DC devices could detect changes in the output optical intensity by monitoring the near-field pattern using a CCD camera. The signal was enhanced 60 × using a 1500 µm-long DC device. For large cladding refractive-index changes between air and water, the normalized signal changed cyclically several times between 0 and 1. The results suggest that the DC can be the basis for miniaturized two-dimensionally integrated biochemical sensors.

Effects of physical and morphometric factors on nutrient removal properties in agricultural ponds.

Effects of physical and morphometric factors on nutrient removal properties were studied in small agricultural ponds with different depths, volumes, and residence times in western Japan. Average residence time was estimated to be >15 days, and it tended to decrease from summer to winter because of the increase in water withdrawal for agricultural activity. Water temperature was clearly different between the surface and bottom layers; this indicates that thermal stratification occurred in summer. Chlorophyll-a was significantly high (>20 µg/L) in the surface layer (<0.5 m) and influenced by the thermal stratification. Removal ratios of dissolved total nitrogen (DTN) and dissolved total phosphorus in the ponds were estimated to be 53-98% and 39-98% in August and 10-92% and 36-57% in December, respectively. Residence time of the ponds was longer in August than in December, and DTN removal, in particular, was more significant in ponds with longer residence time. Our results suggest residence time is an important factor for nitrogen removal in small agricultural ponds as well as large lakes.

Large scale cDNA sequencing for analysis of quantitative and qualitative aspects of gene expression.

Large scale sequencing of cDNAs provides a complementary approach to structural analysis of the human genome by generating expressed sequence tags (ESTs). We have initiated the large-scale sequencing of a 3'-directed cDNA library from the human liver cell line HepG2, that is a non-biased representation of the mRNA population. 982 random cDNA clones were sequenced yielding more than 270 kilobases. A significant portion of the identified genes encoded secretable proteins and components for protein-synthesis. The abundance of cDNA species varied from 2.2% to less than 0.004%. Fifty two percent of the mRNA were abundant species consisting of 173 genes and the rest were non-abundant, consisting of about 6,600 genes.

[Management of patients with arrhythmias undergoing thoracic surgery].

Recentry, surgical candidates have become older and have more surgical risk factors, perioperative patient management become more important than before. In the patients with significant arrhythmia observed in the preoperative period, examination of the baseline heart disease, i.e. myocardial ischemia or congestive heart failure, is mandatory and, if necessary, adequate treatment such as defibrillator, the implantation of a pacemaker, anticoagulation therapy, or other medical therapy should be performed. In the patients with atrial fibrillation, clinical prediction rules such as the congestive heart failure, hypertension, age>75, diabetes, previous stroke or transient ischemic attack (TIA) [CHADS 2] score have been developed to identify those patients at highest risk for thrombo-embolism and can be used when assessing the need for bridging anticoagulation by heparin prior to surgery. The electrical stimulus from electrocautery may inhibit demand pacemakers or may reprogram the pacemaker. An asynchronous or non-sensing pacemaker mode is recommended in patients who are pacemaker dependent and whose underlying rhythm is unreliable. The device has to be checked to ensure appropriate programming and sensing pacing thresholds after surgery. The implantable cardioverter defibrillator should be turned off during surgery and switched on in the recovery phase before discharge to the ward.

DDBJ with new system and face.

DDBJ (http://www.ddbj.nig.ac.jp) collected and released 1 880 115 entries or 1 134 086 245 bases in the period from July 2006 to June 2007. The released data contains the high-throughput cDNAs of cricket and high-quality draft genome of medaka among others. Our computer system has been upgraded since March 2007. Another new aspect is an efficient data retrieval tool that has recently been equipped and served at DDBJ. It is called All-round Retrieval for Sequence and Annotation, which enables the user to search for keywords also in the Feature/Qualifier of the International Nucleotide Sequence Database Collaboration (http://www.insdc.org/). We will also replace our home page with a more efficient one by the end of 2007.

Functional and evolutionary insights into vertebrate kisspeptin systems from studies of fish brain.

The kiss1 gene product kisspeptin is now considered to be an essential regulator of the hypothalamic-pituitary-gonadal (HPG) axis in most vertebrate species. Recent findings in fishes are beginning to set a new stage for the kisspeptin study; the existence of paralogous kisspeptin genes as well as kisspeptin receptor (formerly called GPR54) genes has quite recently been reported in several fish and amphibian species. The fishes may provide excellent animal models for the study of general principles underlying the kisspeptin and kisspeptin receptor systems of vertebrates from the evolutionary viewpoint. Unlike placental and marsupial mammalian species mainly studied so far, many teleost species have two paralogous genes of kisspeptin, kiss1 and kiss2. Medaka, Oryzias latipes, in which kiss1 and kiss2 are expressed in distinctive hypothalamic neuron populations, is a good model system for the study of central regulation of reproduction. Here, the kiss1 system but not the kiss2 system shows expression dynamics strongly indicative of its direct involvement in the HPG axis regulation via its actions on GnRH1 neurons. On the other hand, the kiss1 gene is missing, and only kiss2 is expressed in some fish species. Also, there are some recent reports that Kiss2 peptide may be a potent regulator of reproduction in some fish species. The ancestral vertebrate probably already had two paralogous kiss genes, and their main function was the HPG axis regulation. In the species that retained both paralogues during evolution, either Kiss1 or Kiss2 predominantly retains its ability for the HPG axis regulation, while the other may assume new non-reproductive functions (neofunctionalization). Alternatively, both the paralogues may assume complementary functions in the HPG axis regulation (subfunctionalization). After the divergence of teleost and tetrapod lineages, either one of the two paralogues, or even both in birds, have been lost (degradation) or became a pseudogene (non-functionalization), but the remaining paralogue retained its original function of HPG axis regulation. The identification of multiple forms of kisspeptin receptors and the rather promiscuous ligand-receptor relationships has led to the further proposal that such promiscuousness may be the basis for the functional robustness of kisspeptin and kisspeptin receptor systems in the HPG axis regulation, when one or both paralogous genes are lost or functionally partitioned during evolution.

Ecotoxicological characterization of tannery wastewater in Dhaka, Bangladesh.

Tanning industries are one of the main economic activities in Bangladesh. It has been well documented that wastewater discharged from tanneries without appropriate treatment results in detrimental effects on the ecosystem. No ecotoxicity evaluation of any aquatic environment in Bangladesh has been conducted so far. In this study a battery of toxicity bioassays and chemical analysis were carried out from water samples obtained from three sampling points: upstream from discharging site on River Buriganga (S1), raw wastewater effluent (S2), and downstream the discharging sluice gate (S3), in the Hazaribagh tannery area of Dhaka City, Bangladesh. While S1 and S3 water samples did not show significant toxicity in the bioassays tested, S2 exhibited high acute toxicity to the bacterium Vibrio fischeri (15-min Microtox test, EC50 = 9.8%), the higher plant Lactuca sativa (5-day root elongation inhibition test, EC50 = 14.2%), and the microcrustacean Daphnia magna (24-hour mobility test, EC50 = 31.5%). The results suggested that the raw wastewater effluent had detrimental effects on broad spectrum of organisms in the aquatic ecosystem and bacterium was the most sensitive. The chemical analysis revealed that sample S2 contained an extremely high concentration of chromium (47 g l(-1)). Additionally microbiological analysis indicated that the sampling area is impacted by fecal pollution, increasing the environmental health risk for its inhabitants.

Luminal hydrogen sulfide plays a pronociceptive role in mouse colon.

OBJECTIVE: Given recent evidence that hydrogen sulfide (H(2)S), a gasotransmitter, promotes somatic pain through redox modulation of T-type Ca(2+) channels, the roles of colonic luminal H(2)S in visceral nociceptive processing in mice were examined. METHODS: After intracolonic administration of NaHS, an H(2)S donor, visceral pain-like behaviour and referred abdominal allodynia/hyperalgesia were evaluated. Phosphorylation of extracellular signal-regulated protein kinase (ERK) in the spinal dorsal horn was determined immunohistochemically. The whole-cell recording technique was used to evaluate T-type Ca(2+) currents (T-currents) in cultured dorsal root ganglion (DRG) neurons. RESULTS: Like capsaicin, NaHS, administered intracolonically at 0.5-5 nmol per mouse, triggered visceral nociceptive behaviour accompanied by referred allodynia/hyperalgesia in mice. Phosphorylation of ERK in the spinal dorsal horn was detected following intracolonic NaHS or capsaicin. The behavioural effects of intracolonic NaHS were abolished by a T-type channel blocker or an oxidant, but not inhibitors of L-type Ca(2+) channels or ATP-sensitive K(+) (K(ATP)) channels. Intraperitoneal NaHS at 60 micromol/kg facilitated intracolonic capsaicin-evoked visceral nociception, an effect abolished by the T-type channel blocker, although it alone produced no behavioural effect. In DRG neurons, T-currents were enhanced by NaHS. CONCLUSIONS: These findings suggest that colonic luminal H(2)S/NaHS plays pronociceptive roles, and imply that the underlying mechanisms might involve sensitisation/activation of T-type channels probably in the primary afferents, aside from the issue of the selectivity of mibefradil.

Beneficial effects of leukotriene receptor antagonists in the prevention of cedar pollinosis in a community setting.

BACKGROUND: In recent years, many countries have experienced an increase in the prevalence of allergic rhinitis. No effective approach is currently available to prevent the onset of symptoms in allergic individuals. Pranlukast, a leukotriene receptor antagonist with a good safety and efficacy record for the management of allergic inflammation, may be appropriate for early intervention in the management of pollinosis. OBJECTIVE: To investigate the efficacy of pranlukast as an early intervention in the control of cedar pollinosis. METHODS: In a double-blind comparative study, pranlukast (n = 102) or placebo (n = 91) was administered to cedar pollinosis patients immediately before the start of the dispersion season and continued for 4 weeks. Subsequently, pranlukast was administered to all patients for 2 weeks until the end of the cedar pollen dispersion season (mid-March). All patients were carefully monitored for severity of nasal symptoms, symptom scores, medication scores, symptom-medication scores, and quality of life (QOL). RESULTS: Compared with placebo, therapy with pranlukast before and during the dispersion of cedar pollen in these patients significantly improved nasal symptoms (paroxysmal sneezing, rhinorrhea, and nasal congestion), symptom scores, and symptom-medication scores. The drug also significantly reduced deterioration of QOL, and improved nasal symptoms and QOL throughout the dispersion period. CONCLUSION: Administering pranlukast immediately before the beginning of cedar pollen dispersion is effective in reducing symptoms of allergic rhinitis throughout the dispersion period.

Omalizumab is more effective than suplatast tosilate in the treatment of Japanese cedar pollen-induced seasonal allergic rhinitis.

BACKGROUND: Seasonal allergic rhinitis (SAR) induced by Japanese cedar pollens is a major problem in Japan. Omalizumab, a humanized monoclonal anti-IgE antibody, improves symptoms associated with SAR, but a comparative study with an anti-allergy drug has not yet been conducted. OBJECTIVE: To compare the efficacy and safety of omalizumab with suplatast tosilate, a selective T-helper type 2 (Th2) cytokine inhibitor, in patients with Japanese cedar pollen-induced SAR. METHODS: A randomized, double-blind, double-dummy study was conducted in 308 Japanese patients with a history of moderate-to-severe SAR who showed a CAP-RAST value (> or =2+) specifically to Japanese cedar pollens. Patients were treated for 12 weeks with omalizumab plus placebo of suplatast tosilate or suplatast tosilate plus placebo of omalizumab. RESULTS: The mean daily nasal symptom medication scores (sum of the daily nasal symptom severity score and daily nasal rescue medication score) were significantly lower in the omalizumab group than in the suplatast tosilate group during three evaluation periods (P<0.001). The omalizumab group also had significantly lower mean daily nasal severity scores, each of the mean daily nasal and ocular symptom severity scores (sneezing, runny nose, stuffy nose, itchy nose, itchy eyes, watery eyes, and red eyes). Omalizumab reduced rescue medication requirements, and the proportion of days with any rescue medication use in the omalizumab group was significantly lower. Serum-free IgE levels markedly decreased in the omalizumab group and it was associated with clinical efficacy. The adverse reaction profiles were similar between the two groups. The overall incidence of injection site reactions was higher in the omalizumab group than in the suplatast tosilate group, but all these events were of mild degree. No anti-omalizumab antibodies were detected. CONCLUSION: Omalizumab showed significantly greater improvements than suplatast tosilate in the treatment of SAR induced by Japanese cedar pollens.

Allergen-specific immunotherapy alters the expression of B and T lymphocyte attenuator, a co-inhibitory molecule, in allergic rhinitis.

BACKGROUND: B7/CD28 family co-signalling molecules play a key role in regulating T cell activation and tolerance. Allergen-specific immunotherapy (SIT) alters allergen-specific T cell responses. However, the effect of SIT on the expression of various co-signalling molecules has not been clarified. OBJECTIVE: We sought to determine whether SIT might affect the expression of three co-inhibitory molecules, programmed death (PD)-1, B7-H1 and B and T lymphocyte attenuator (BTLA), in Japanese cedar pollinosis (JCP). METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from JCP patients who had or had not received SIT. PBMC were cultured in the presence or absence of Cry j 1, after which the cell surface expression of PD-1, B7-H1 and BTLA, as well as IL-5 production, were determined. In addition, the effect of BTLA cross-linking on IL-5 production was examined. RESULTS: After Cry j 1 stimulation, no significant differences in PD-1 and B7-H1 expression were observed between SIT-treated and SIT-untreated patients. BTLA expression was down-regulated in untreated patients after Cry j 1 stimulation and up-regulated in SIT-treated patients. Up-regulation of BTLA in SIT-treated patients was particularly apparent in a CD4(+) T cell subset. IL-5 production was clearly reduced among SIT-treated patients, and the observed changes in BTLA expression correlated negatively with IL-5 production. Moreover, immobilization of BTLA suppressed IL-5 production in JCP patients. CONCLUSION: These results suggest that both IL-5 production and down-regulation of BTLA in response to allergen are inhibited in SIT-treated patients with JCP. BTLA-mediated co-inhibition of IL-5 production may contribute to the regulation of allergen-specific T cell responses in patients receiving immunotherapy.

Association of serum interleukin-33 level and the interleukin-33 genetic variant with Japanese cedar pollinosis.

BACKGROUND: IL-33, an IL-1-like cytokine, is a ligand for IL1RL1, which is an important effector molecule of type 2 T helper responses. Although IL-33/IL1RL1 interaction has been suggested to be important in induction of allergic airway inflammation, serum levels of IL-33 and the genetic influences of the polymorphisms of IL-33 in human allergic diseases are unclear. OBJECTIVE: The aim of this study was to examine whether the serum IL-33 level and polymorphisms in IL-33 are associated with Japanese cedar (JC) pollinosis, the most common form of allergic rhinitis, and a major public health problem, in Japan. METHODS: We performed linkage disequilibrium (LD) mapping of the gene using the HapMap database, and two selected tag single nucleotide polymorphisms were genotyped. We conducted an association study of IL-33 (JC pollinosis, n=170; normal controls, n=100) and measured the IL-33 levels in sera of the 270 subjects by ELISA. RESULTS: Serum levels of IL-33 were significantly higher in patients with JC pollinosis (P=0.0018) than in controls. In genetic association analysis, we found a positive association between the polymorphism and JC pollinosis (P=0.048). CONCLUSION: Our results support a role for IL-33 in the pathogenesis of JC pollinosis.

A mesangium-predominant gene, megsin, is a new serpin upregulated in IgA nephropathy.

Mesangial cells play an important role in maintaining a structure and function of the glomerulus and in the pathogenesis of glomerular diseases. To identify a specific gene expressed in human mesangial cells, we used a rapid large-scale DNA sequencing and computerized data processing to compare the transcripts in cultured human mesangial cells with various different cells and organs. Using this novel approach, we discovered a new mesangium-predominant gene termed "megsin." We obtained a full-length cDNA clone of megsin, which coded for a novel 380-amino acid protein. Amino acid homology search revealed that megsin belonged to the serpin (serine protease inhibitor) superfamily. The amino acid sequences in the reactive loop site of megsin showed characteristic features of functional serpins. Northern blot and reverse-transcribed PCR analyses of various tissues and cells demonstrated that megsin was predominantly expressed in human mesangial cells. In situ hybridization studies showed the megsin expression in the mesangium of normal glomeruli, while it increased in the expanded mesangium of glomeruli from patients with IgA nephropathy with the degree of mesangial proliferation. Here we report a new human mesangium-predominant gene that may function as an inhibitory serpin in normal and abnormal biological processes of glomerulus.

DDBJ in collaboration with mass-sequencing teams on annotation.

In the past year, we at DDBJ (DNA Data Bank of Japan; http://www.ddbj.nig.ac.jp) collected and released 1,066,084 entries or 718,072,425 bases including the whole chromosome 22 of chimpanzee, the whole-genome shotgun sequences of silkworm and various others. On the other hand, we hosted workshops for human full-length cDNA annotation and participated in jamborees of mouse full-length cDNA annotation. The annotated data are made public at DDBJ. We are also in collaboration with a RIKEN team to accept and release the CAGE (Cap Analysis Gene Expression) data under a new category, MGA (Mass Sequences for Genome Annotation). The data will be useful for studying gene expression control in many aspects.

[Mediastinal aberrant goiter; report of a case].

A 54-year-old woman was admitted to our hospital because of an abnormal shadow on chest X-ray. Chest computed tomography (CT) scan and magnetic resonance imaging (MRI) demonstrated an anterior mediastinal tumor. The tumor was resected completely through a median sternotomy. The tumor was dissected successfully from the surrounding vessels in spite of the heavy adhesion to them. The blood supply of the tumor was from a branch of the brachiocephalic artery. The tumor was 9 x 8 x 3 cm in size, and was diagnosed as an aberrant mediastinal goiter since it showed no communication to the thyroid gland. An aberrant mediastinal goiter is a quite rare entity of diseases and its removal through the neck would result in uncontrolled blood loss because its blood supply usually derives from intrathoracic vessels.

Expression of isotocin is male-specifically up-regulated by gonadal androgen in the medaka brain.

Oxytocin, a mammalian neuropeptide primarily synthesised in the supraoptic and paraventricular nuclei of the hypothalamus, mediates a variety of physiological and behavioural processes, ranging from parturition and lactation to affiliation and prosociality. Multiple studies in rodents have shown that the expression of the oxytocin gene (Oxt) is stimulated by oestrogen, whereas androgen has no apparent effect. However, this finding is not consistent across all studies, and no study has examined sex steroid regulation of Oxt or its orthologues in other animals. In the present study, we show that, in the teleost fish, medaka (Oryzias latipes), the expression of the isotocin gene (it), the teleost orthologue of Oxt, in the parvocellular preoptic nuclei (homologous to the mammalian supraoptic nucleus) is male-specifically up-regulated by gonadal androgen, whereas it expression in the magnocellular/gigantocellular preoptic nuclei (homologous to the mammalian paraventricular nucleus) is independent of sex steroids in both sexes. None of the it-expressing neurones appear to co-express androgen receptors, suggesting that the effect of androgen on it expression is indirect. We found that the expression of a kisspeptin gene, kiss2, in the male brain is dependent on gonadal androgen, raising the possibility that the androgen-dependent expression of it may be mediated by kiss2 neurones. Our data also show that the isotocin peptide synthesised in response to androgen is axonally transported to the posterior pituitary to act peripherally. Given that levels of it expression are higher in females than in males, androgen may serve to compensate for the female-biased it expression to ensure a role for isotocin that is equally important for both sexes. These results are unexpectedly quite different from those reported in rodents, indicating that the regulatory role of sex steroids in Oxt/it expression has diverged during evolution, possibly with accompanying changes in the role of oxytocin/isotocin.

Three urocortins in medaka: identification and spatial expression in the central nervous system.

The urocortin (UCN) group of neuropeptides includes urocortin 1/sauvagine/urotensin 1 (UTS1), urocortin 2 (UCN2) and urocortin 3 (UCN3). In recent years, evidence has accumulated showing that UCNs play pivotal roles in mediating stress response and anxiety in mammals. Evidence has also emerged regarding the evolutionary conservation of UCNs in vertebrates, but very little information is available about UCNs in non-mammalian vertebrates. Indeed, at present, there are no reports of the empirical identification of ucn2 in non-mammalian vertebrates or of the distribution of ucn2 and ucn3 expression in the adult central nervous system (CNS) of these animals. To gain insight into the evolutionary nature of UCNs in vertebrates, we cloned uts1, ucn2 and ucn3 in a teleost fish, medaka and examined the spatial expression of these genes in the adult brain and spinal cord. Although all known UCN2 genes except those in rodents have been reported to likely lack the necessary structural features to produce a functional pre-pro-protein, all three UCN genes in medaka, including ucn2, displayed all of these features, suggesting their functionality. The three UCN genes exhibited distinct spatial expression patterns in the medaka brain: uts1 was primarily expressed in broad regions of the dorsal telencephalon, ucn2 was expressed in restricted regions of the thalamus and brainstem and ucn3 was expressed in discrete nuclei throughout many regions of the brain. We also found that these genes were all expressed throughout the medaka spinal cord, each with a distinct spatial pattern. Given that many of these regions have been implicated in stress responses and anxiety, the three UCNs may serve distinct physiological roles in the medaka CNS, including those involved in stress and anxiety, as shown in the mammalian CNS.

Energetic proton acceleration and bunch generation by ultraintense laser pulses on the surface of thin plasma targets.

Energetic proton acceleration from concave targets, the front of which were irradiated with 40 fs laser pulses with an intensity of 10(20)W/cm(2), has been studied as a function of the depth of the concave shape. Three kinds of targets, a triangular concave target, a circular concave target and a parabolic concave target are considered. When the depth of the concave shape was varied, the peak proton energy showed a maximum. The underlying mechanism for the existence of a maximum peak proton energy is presented by tracing the proton trajectory. It is concluded that a parabolic concave target is the best, among the targets considered, for accelerating a proton beam, since a proton beam from a parabolic concave target goes through the strongest electric field.