bluuebunny/crossref_metadata_2025 huggingface dataset:
L‐Type Calcium Current Reactivation Contributes to Arrhythmogenesis Associated with Action Potential Triangulation
Authors: GUO DONGLIN , ZHAO XIAOJING , WU YING , LIU TENGXIAN , KOWEY PETER R. , YAN GAN‐XIN
Published: January 2007

Introduction: The morphology of the mammalian cardiac action potential (AP) is an important factor in the susceptibility to drug‐induced early afterdepolarizations (EADs) that may initiate Torsade de Pointes (TdP). AP triangulation has been shown to be an important predictor of drug‐induced TdP.

Methods and Results: APs from guinea pig and rabbit left ventricular single myocytes were recorded using a microelectrode‐recording technique. ICa‐L currents were recorded in ventricular myocytes of guinea pig and rabbit using patch‐clamping technique. At a stimulus frequency of 0.5 Hz, guinea pig ventricular myocytes displayed a square‐like AP, whereas rabbit ventricular myocytes exhibited a triangle‐like AP. Dofetilide‐induced EADs were observed only in rabbit ventricular myocytes. Under the guinea pig AP clamping condition, the normalized ICa‐L instant reactivation currents in guinea pig and rabbit myocytes at voltages of –40 mV were 0.13 ± 0.01 and 0.14 ± 0.01, respectively. However, when rabbit AP served as the first clamping voltage, the normalized ICa‐L reactivation currents at –40 mV in guinea pig and rabbit myocytes were 0.20 ± 0.01, 0.21 ± 0.01, respectively, indicating that the ICa‐L recovery from inactivation in the rabbit triangular AP condition was significantly faster than in the guinea pig square AP condition. Comparison of the voltage clamp using the triangular waveform with the square waveform further confirmed that triangulation accelerates ICa‐L recovery from inactivation.

Conclusions: In rabbit ventricular myocardium, AP triangulation accelerates ICa‐L channel recovery from inactivation, leading to instability of the cell membrane potential during repolarization, which is capable of initiating TdP.
Assessment of Surgically Unroofed Coronary Sinus by Live/Real Time Three‐Dimensional Transthoracic Echocardiography
Authors: Singh Anurag , Nanda Navin C. , Romp Robb L. , Kirklin James K.
Published: January 2007

Both two‐dimensional transthoracic echocardiography (2DTTE) and live/real time three‐dimensional transthoracic echocardiography (3DTTE) were attempted in a 25‐year‐old morbidly obese female with total anomalous pulmonary venous return (TAPVR) into the coronary sinus (CS) in whom surgical unroofing of CS with patch closure of CS ostium was performed in infancy to redirect pulmonary venous flow into the left atrium (LA). The patient had become increasingly symptomatic over the past 1 year because of severe left‐to‐right shunting due to dehiscence of the patch used to close the CS ostium. Despite a poor acoustic window, 3DTTE was able to identify a communication between the LA and CS which resulted from surgical unroofing of the CS as well as flow signals moving into the right atrium from the CS. These findings were not detected by 2DTTE.
Expression of human telomerase reverse transcriptase and cyclin‐D1 in olfactory neuroblastoma
Authors: WANG SHENG‐LAN , CHEN WAN‐TZU , LI SHAU‐HSUAN , LI SUNG‐WEI , YANG SHEAU‐FANG , CHAI CHEE‐YIN
Published: January 2007

Olfactory neuroblastoma is an uncommon neoplasm. Typically, these tumors are indolent with long‐standing symptomatology, but the fact that the lesions are indeed malignant has been proven by the repeated demonstration that they can metastasize to distant organs. Suitable prognostic factors are lacking and therapeutic strategy still remains controversial. Expression of human telomerase reverse transcriptase (hTERT) is associated with most human malignancies and high levels have been correlated with poor prognosis in many cancers. In comparison, overexpression of cyclin‐D1 occurs in several malignancies and has been associated with aggressive tumor behavior and poorer prognosis. In this study, we collected 16 olfactory neuroblastomas from the Kaohsiung Medical University Hospital. The aim was to investigate the value of immunoexpression of hTERT and cyclin‐D1 in correlation with clinicopathologic features of olfactory neuroblastoma. Low and high cyclin‐D1 expression was found in 6 and 10 cases, respectively. For hTERT, low and high protein expression was detected in 5 and 11 tumors, respectively. Cyclin‐D1 expression was not correlated with selected parameters. However, high hTERT expression was significantly correlated with high Kadish stage. In conclusion, high hTERT expression can be considered a potential indicator of aggressive olfactory neuroblastoma.
Congenital cervical immature teratoma arising in the left lobe of the thyroid gland.
Authors: OKA KUNIYUKI , OKANE MASATO , OKUNO SUZUKA , KAWASAKI TOMOAKI , YONEKAWA NOBUO , OKANO MASAMICHI , NAKAYAMA MASAHIRO
Published: January 2007

We report on a fetal autopsy case in which a congenital cervical immature teratoma was diagnosed. A 24‐year‐old Japanese woman had carried a male fetus that was aborted because of a cervical tumor at 20 weeks 5 days of gestation. The cervical tumor weighed 93 g and measured 7.5×5.5×5 cm. The soft tumor was encapsulated by a fibrous layer, was solid with small cysts on the cut surface, and showed a brain‐like appearance. The tumor was composed of neoplastic cells derived from the three germ cell layers: ectoderm, mesoderm, and endoderm. The cells showed both immature and mature features. Small areas of thyroid tissue were detected in the cervical tumor. The left lobe of the thyroid gland was not observed, but the right lobe of the thyroid gland was present laterally between the trachea and the esophagus. Therefore, we concluded that the cervical tumor had arisen in the left lobe of the thyroid gland rather than from the soft tissue of the neck.
The human placenta from heavy smokers: evaluation of vasoactive peptides by immunohistochemistry
Authors: CLAUSEN H. V. , LARSEN L. GRUPE , JØRGENSEN A. , BZOREK M.
Published: January 2007

The study aimed to demonstrate the expression of nitric oxide converting enzyme, nitric oxide synthase (e‐NOS), and endothelin‐1 (Et‐1) in formalin‐fixed paraffin‐embedded placental tissue, and to demonstrate a difference in staining intensity between heavy smokers and non‐smokers. Term placentas from pregnancies from otherwise healthy women smoking 15 or more cigarettes per day (heavy smokers) and term placentas from a matching group of non‐smokers were included. The antibodies for Et‐1 and e‐NOS are recommended for cryostat sections. We evaluated the antibodies on paraffin‐embedded tissue combined with the streptavidin‐biotin‐peroxidase technique. Et‐1 and e‐NOS were demonstrated in the placental vasculature, the trophoblast, and the amnion. A blinded comparative study showed no reproducible significant differences in the staining intensity of the antigen‐antibody reaction to Et‐1 and e‐NOS between the two groups.
Expression pattern of adhesion molecules (E‐cadherin, α‐, β‐, γ‐catenin and claudin‐7), their influence on survival in primary breast carcinoma, and their corresponding axillary lymph node metastasis
Authors: PARK DAEHOON , KÅRESEN ROLF , AXCRONA ULRIKA , NOREN TOVE , SAUER TORILL
Published: January 2007

Reduced intercellular adhesion is implicated in the development of metastasis. This study investigates the expression of intercellular adhesion molecules (E‐cadherin, α‐, β‐, γ‐catenin and claudin‐7) and their influence on survival in primary breast carcinomas and corresponding axillary lymph node metastases (ALNM), and evaluates associations between them and with clinicopathological factors. The expression of adhesion molecules was analyzed immunohistochemically in tissues from 196 patients with primary invasive breast carcinomas and their nodal metastases (174 ductal and 22 lobular types). The expression was evaluated using semi‐quantitative scoring of the intensity and proportion of immunoreactivity. All five adhesion proteins showed significantly reduced expression in primary ductal carcinomas with re‐expression in ALNM (p<0.001). In uni‐ and multivariate analyses, the expression of E‐cadherin in the primary tumours was a significant predictor of disease‐free survival and distant disease‐free survival. Thus, abnormal E‐cadherin expression in the primary invasive breast carcinoma seems to be an independent prognostic biomarker in predicting a shorter survival in node‐positive breast cancer patients. The results indicate that abnormal expression of the adhesion molecules in the primary tumours with re‐expression in corresponding nodal metastases is a common event in breast ductal carcinomas and may play a central role in establishing metastasis.
Inflammation, Cancer and Chemoresistance: Taking Advantage of the Toll‐Like Receptor Signaling Pathway
Authors: Chen Rui , Alvero Ayesha B. , Silasi Dan‐Arin , Mor Gil
Published: January 2007

The association between chronic inflammation and cancer has long been observed. Furthermore, NF‐κB activation and the subsequent production of cytokines, chemokines, growth factors, and antiapoptotic proteins has been found to be involved in cancer progression and chemoresistance. However, the signals inducing NF‐κB in cancer cells are still not well understood. Here, we reviewed the association between chronic inflammation and cancer, the role of NF‐κB and its inhibitors as potential anticancer drugs, and Toll‐like receptors as possible signal initiators for NF‐κB activation and inflammation‐induced carcinogenesis and chemoresistance. Furthermore, we propose that, the stimulation of Toll‐like receptors by microbial components and/or endogenous ligands may represent the initial signal promoting a proinflammatory environment that will enhance tumor growth and chemoresistance.
NK Cell Function in the Human Female Reproductive Tract
Authors: Sentman Charles L. , Wira Charles R. , Eriksson Mikael
Published: January 2007

Problem

Uterine NK cells have a unique phenotype compared with blood NK cell subsets, yet little is known about how NK cells function as a part of the innate immune cell network in the female reproductive tract.

Method of Study

The expression of key receptors and function of uterine NK cells in response to cytokines, sex hormones, and pathogen associated molecular patterns (PAMPs) was analyzed. This article summarizes recent findings on the biology and function of NK cells in the female reproductive tract.

Results

Uterine NK cells express Toll‐like receptors and respond to cytokines and PAMPs under specific conditions. Evidence indicates that NK cells play an important role in the reorganization of blood vessels during pregnancy.

Conclusions

Human uterine NK cells are a major population of leukocytes in the endometrium and play an important role as a component of host defense and in successful reproduction.
Effect of Experimental Genital Mycoplasmosis on Production of Matrix Metalloproteinases in Membranes and Amniotic Fluid of Sprague–Dawley Rats
Authors: Peltier Morgan R. , Barney Brandon M. , Brown Mary B.
Published: January 2007

Problem

Preterm, premature rupture of membranes (PPROM) is a dire pregnancy outcome that is frequently associated with infection by the genital mycoplasmas, Mycoplasma hominis, Ureaplasma parvum, and U. urealyticum. One potential mechanism by which these microorganisms may cause PPROM is by increasing the concentration of matrix metalloproteinases (MMPs) in the membranes and amniotic fluid. We tested this hypothesis in a well‐defined model system of genital infection with M. pulmonis, a natural reproductive pathogen of rats.

Method of study

Timed‐pregnant, specific pathogen‐free, Sprague–Dawley rats were infected with 107 CFU M. pulmonis at gestation day (gd) 14. Controls received an equivalent volume (100 μL) of sterile medium. At gd 18, rats were euthanized, and membranes and amniotic fluids were harvested and stored at −70°C until analysis. Proteinase activity of amniotic fluid and membranes was resolved on discontinuous 7.5% sodium dodecyl sulfate–polyacrylamide gel electrophoresis gelatin zymography gels. Band intensity was determined using a digital gel documentation system and the manufacturer's software (Kodak).

Results

Gelatinolytic activity associated with a band similar in molecular weight to ProMMP‐9 (92 kDa, the inactive precursor of MMP‐9) was significantly increased in amniotic fluids and membranes harvested from M. pulmonis‐treated pups at gd 18 when compared with tissues harvested from control pups. Both ProMMP‐9 and ProMMP‐2 (72 kDa, the inactive precursor of MMP‐2) were increased in infected animals at gd 21.

Conclusion

Our study suggests that the genital mycoplasmas can increase MMP‐9 production in vivo.
Relationship Between Level of Serum Sperm Immobilizing Antibody and Its Inhibitory Effect on Sperm Migration through Cervical Mucus in Immunologically Infertile Women
Authors: Shibahara Hiroaki , Shiraishi Yasuko , Hirano Yuki , Kasumi Hiroyuki , Koyama Koji , Suzuki Mitsuaki
Published: January 2007

Problem

Sperm immobilizing antibodies often interfere with the penetration of sperm through the cervical mucus. However, the relationship between sperm immobilizing antibody titer and the result of the post‐coital test (PCT) has not yet been clarified. The aim of this study was to investigate whether the 50% sperm immobilization unit (SI50) titer, a quantitative measure of sperm immobilizing antibody, in patients’ sera was correlated with the result of PCT.

Method of study

The sperm immobilization test (SIT) was performed for 2834 infertile women in two university hospitals. The SI50 titers were evaluated by quantitative SIT. In some cases with sperm immobilizing antibody, PCT was carried out before ovulation and assessed according to the criteria of World Health Organization (1992). Infertile couples with abnormal semen characteristics were excluded.

Results

Seventy‐four of 2834 women had sperm immobilizing antibodies in their sera, giving a positive rate of 2.6%. Twenty‐four (77.4%) of 31 women with sperm immobilizing antibodies and 28 (20.4%) of 137 women without the antibody had abnormal PCT results. There was a significant difference between the two groups (P < 0.0001). When patients with sperm immobilizing antibodies were divided into two groups according to the SI50 titers, the abnormal result of PCT was obtained in all 10 patients with high (>10) SI50 titers, while that was 14 (66.7%) in 21 patients with low (10) SI50 titers. There was a significant difference between the two groups (P = 0.04).

Conclusion

The SI50 titer in the serum can predict inhibitory effects on sperm migration through cervical mucus in immunologically infertile women. Evaluation of the SI50 titers in patients’ sera seems to be useful for decision‐making in infertile women with sperm immobilizing antibodies regarding whether they have the possibility of conceiving by timed intercourse.
Implication of RANTES in the Modulation of Alloimmune Response By Progesterone During Pregnancy
Authors: Ramhorst Rosanna , Gutiérrez Gabriela , Corigliano Adriana , Junovich G. , Fainboim Leonardo
Published: January 2007

Problem

Several studies indicate that RANTES (regulated on activation, normal T cell expressed and secreted) is able to downregulate T‐cell responses which suggest it might be relevant for fetal tolerance induction. However, the role of RANTES in pregnancy had not been established. Here we investigate RANTES regulation during early pregnancy and potential failures leading to losses of pregnancies.

Method of study

RANTES and progesterone levels were determined in sera and feto‐placental units from high resorption rate CBA/J × DBA/2 pregnant females and compared with CBA/J × BALB/c normal pregnant mice. RANTES in vitro modulation was also studied in nulliparous, primiparous and multiparous CBA/J and BALB/c cells in response to paternal alloantigen and progesterone stimulation.

Results

Nulliparous CBA/J females were quantitatively deficient in RANTES sera levels, whereas pregnancies with male BALB/c or DBA/2 increased its production. However, feto‐placental units from CBA/J females are high producers of progesterone and RANTES.

Conclusion

These data suggest that the beneficial effect of RANTES on feto‐maternal interface requires an optimal concentration range and might be modulated by progesterone, hence exacerbated placental expression could be associated with high resorption rate.
The reconstitution of mammalian prion infectivity de novo
Authors: Baskakov Ilia V.
Published: January 2007

The discovery of prion disease transmission in mammals, as well as a non‐Mendelian type of inheritance in yeast, has led to the establishment of a new concept in biology, the prion hypothesis. The prion hypothesis postulates that an abnormal protein conformation propagates itself in an autocatalytic manner using the normal isoform of the same protein as a substrate and thereby acts either as a transmissible agent of disease (in mammals), or as a heritable determinant of phenotype (in yeast and fungus). While the prion biology of yeast and fungus supports this idea strongly, the direct proof of the prion hypothesis in mammals, specifically the reconstitution of the disease‐associated isoform of the prion protein (PrPSc) in vitro de novo from noninfectious prion protein, has been difficult to achieve despite many years of effort. The present review summarizes our current knowledge about the biochemical nature of the prion infectious agent and structure of PrPSc, describes potential strategies for generating prion infectivity de novo and provides some insight on why the reconstitution of infectivity has been difficult to achieve in vitro. Several hypotheses are proposed to explain the apparently low infectivity of the first generation of recently reported synthetic mammalian prions.
Direct identification of hydrophobins and their processing in Trichoderma using intact‐cell MALDI‐TOF MS
Authors: Neuhof Torsten , Dieckmann Ralf , Druzhinina Irina S. , Kubicek Christian P. , Nakari‐Setälä Tiina , Penttilä Merja , von Döhren Hans
Published: January 2007

Intact‐cell MS (ICMS) was applied for the direct detection of hydrophobins in various species and strains of Hypocrea/Trichoderma. In both mycelia and spores, dominating peaks were identified as hydrophobins by detecting mass shifts of 8 Da of reduced and unreduced forms, the analysis of knockout mutants, and comparison with protein databases. Strain‐specific processing was observed in the case of Hypocrea jecorina (anamorph Trichoderma reesei). An analysis of 32 strains comprising 29 different species of Trichoderma and Hypocrea showed hydrophobin patterns that were specific at both at the species and isolate (subspecies) levels. The method therefore permits rapid and direct detection of hydrophobin class II compositions and may also provide a means to identify Trichoderma (and other fungal) species and strains from microgram amounts of biomass without prior cultivation.
ER stress and diseases
Authors: Yoshida Hiderou
Published: January 2007

Proteins synthesized in the endoplasmic reticulum (ER) are properly folded with the assistance of ER chaperones. Malfolded proteins are disposed of by ER‐associated protein degradation (ERAD). When the amount of unfolded protein exceeds the folding capacity of the ER, human cells activate a defense mechanism called the ER stress response, which induces expression of ER chaperones and ERAD components and transiently attenuates protein synthesis to decrease the burden on the ER. It has been revealed that three independent response pathways separately regulate induction of the expression of chaperones, ERAD components, and translational attenuation. A malfunction of the ER stress response caused by aging, genetic mutations, or environmental factors can result in various diseases such as diabetes, inflammation, and neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, and bipolar disorder, which are collectively known as ‘conformational diseases’. In this review, I will summarize recent progress in this field. Molecules that regulate the ER stress response would be potential candidates for drug targets in various conformational diseases.
Pulmonary metastasectomy of renal cell carcinoma: Local experience
Authors: Zhu Tong , Lo Cheuk‐Kin , Chu Colin Shu‐Him , Ma Chan‐Chung , Ko Kai‐Ming , Ho Kwok‐Keung
Published: January 2007

Objective:  Up until now, the prognosis of a patient with disseminated renal cell carcinoma is poor with 5‐year survival less than 2%. In a small subset of patients with isolated pulmonary metastasis, long‐term survival after pulmonary metastasectomy has been reported to be acceptable. The purpose of the present study was to evaluate the result of pulmonary metastasectomy in a local cardiothoracic surgical centre.

Methods:  Patients who had renal cell carcinoma and pulmonary metastasectomy for isolated pulmonary metastasectomy were recruited for the study. Their survival was analysed.

Results:  Between 1992 and 2004, 13 patients underwent 15 operative procedures for pulmonary metastases from renal cell carcinoma. The median follow up was 39.8 months (from 4.6 to 127.5 months). The five‐year survival after pulmonary metastasectomy was 48.3% and median survival was 25.4 months. There was no postoperative mortality. Pulmonary recurrence was the commonest recurrent site after pulmonary metastasectomy.

Conclusion:  Pulmonary metastasectomy for renal cell carcinoma is a safe and effective procedure. And, as the lung is the commonest site of first recurrence after pulmonary metastasectomy, the present study on the control of these occult metastases is necessary.
Neurothekeoma of the sciatic nerve
Authors: Porter Christopher J. W. , Tan Swee T.
Published: January 2007

Neurothekeoma, also known as nerve sheath myxoma, perineural myxoma and plexiform myxoma, is a rare benign neoplasm of presumed nerve sheath origin. This tumour typically presents as a slowly enlarging painless cutaneous swelling most commonly in female adolescents in the head and neck region or upper limb. Nerves in the dermis are more frequently involved than those in the subcutaneous tissue. It rarely affects subfascial peripheral nerves or the central nervous system. Of the 150 cases published since its first description in 1969, three cases involved deep peripheral nerves in the hand. To the best of our knowledge a neurothekeoma affecting a deep peripheral nerve of the lower limb has not been reported. We present such a case involving the sciatic nerve with significantly larger size compared with previously described cases.
Necrotizing soft tissue infections
Authors: Paramythiotis Daniel , Koukoutsis Helias , Harlaftis Nick
Published: January 2007

Necrotizing soft tissue infections (NSTI) represent a spectrum of diseases characterized by extensive rapidly progressive necrosis that may involve the skin, subcutaneous tissues, fascia or muscle. Their progress is extremely fast, leading often to sepsis and septic shock that ends up in multiple organ failure with abrupt and high mortality. A variety of classification systems have been developed based on parameters such as anatomic location of the disease or microbiology. There are a number of factors that predispose to the spread of these soft tissue infections, such as delays in recognition, immune suppression, diabetes mellitus and advanced age. The use of broad‐spectrum antibiotics tends to mask the severity of the underlying infection, modulates the clinical presentation, and even delays hospital admission. The most important factor affecting outcome in NSTI is early diagnosis and aggressive radical surgical treatment. The medical records of 13 patients who had been treated for NSTI from 1996 to 2005 were reviewed, retrospectively. There were eight men (61.5%) and five (38.5%) women. Mean age was 56 years (range 27–73). Seven cases of infection involved the perineal region (54%), two the lower limb, one the upper limb and three the abdominal wall/trunk. The most common associated comorbidity was diabetes mellitus in five patients (38.5%). A single organism was identified in two (15%) and multiple organisms in 11 (85%) patients. Necrotizing aponeurositis Type I was the most common of the polymicrobial necrotizing infections. Overall survival was 85%, and the mean hospital stay for survivors was 35 days (range 17–92).
Mini‐laparoscopic placement of peritoneal dialysis catheter: New technique
Authors: Seleem Mohamed I. , Al‐Hashemy Ahmed M.
Published: January 2007

Background:  Leakage remains a problem with all methods of catheter placement. We describe our experience with a new mini‐laparoscopic technique for catheter placement in patients with end‐stage renal failure.

Patients and methods:  Between May 2002 and March 2004, 24 patients underwent mini‐laparoscopic placement of peritoneal dialysis catheters. All patients had end‐stage renal failure with difficult vascular access for haemodialysis. There were 11 men and 13 women with a mean age of 51.4 years (range: 18–75 years). Operative time, interval to initiation of successful peritoneal dialysis, postoperative pain management, resumption of diet and postoperative complications were recorded.

Results:  The mean operative time was 32.3 min (range: 15–40 min). All patients were given a normal diet on the day of surgery. Postoperative pain was controlled with paracetamol tablets three times daily for 2–3 days. The mean hospital stay was 3.2 days (range: 3–4 days). No patients developed leakage either from the ports or around the catheter. Two (8.3%) patients had blockage of the catheter and underwent diagnostic laparoscopy and laparoscopic correction. Two (8.3%) patients had migration of the catheter which required laparoscopic repositioning. The follow‐up range was between 2 and 22 months.

Conclusion:  Mini‐laparoscopic technique for placement of peritoneal dialysis catheter is unique because it uses only two ports. The catheter is made to exit via a 2 mm port site and does not require specially designed instruments.
Non‐operative management for blunt splenic trauma in children: An updated literature review
Authors: Leung Edmund , Wong Ling , Taylor John
Published: January 2007

Introduction:  The spleen is the most frequently injured abdominal organ in blunt trauma. In the past, any damaged spleen was surgically removed to avoid delayed rupture. Overwhelming infection is a real threat in asplenic children. Therefore, management of blunt splenic injuries has continued to change over the past 20 years towards non‐operative management (NOM) and splenic conservation.

Methods and Materials:  Twenty‐seven international articles on management of traumatic splenic rupture regarding advances in investigative techniques, treatment modalities and management protocols were reviewed.

Results:  With the advent of improved intensive care, interventional radiology and trauma protocols, it is reported that blunt splenic injuries can now be managed conservatively with a success rate of 85%. Computed tomography remains the gold standard of investigation in a stable patient. Focused abdominal sonography for trauma (FAST) offers a useful diagnostic tool in an unstable patient in whom the source of hypovolaemia is uncertain. However, negative FAST does not exclude haemoperitoneum. Furthermore, guidelines complemented by a comprehensive grading system have been devised to identify those patients who could avoid splenectomy. Experienced radiologists have advocated angio‐embolization in stable patients, and their NOM has increased by 15%, although availability is limited. Post‐discharge instructions are routinely given to parents and patients for successful recovery from NOM of splenic rupture.

Conclusion:  Surgeons must be familiar with these options in order to offer the safest and most effective care for children with splenic lacerations.
Oxylipin Pathway in Rice and Arabidopsis
Authors: Chehab E. Wassim , Perea John V. , Gopalan Banu , Theg Steve , Dehesh Katayoon
Published: January 2007

Plants have evolved complex signaling pathways to coordinate responses to developmental and environmental information. The oxylipin pathway is one pivotal lipid‐based signaling network, composed of several competing branch pathways, that determines the plant's ability to adapt to various stimuli. Activation of the oxylipin pathway induces the de novo synthesis of biologically active metabolites called “oxylipins”. The relative levels of these metabolites are a distinct indicator of each plant species and determine the ability of plants to adapt to different stimuli. The two major branches of the oxylipin pathway, allene oxide synthase (AOS) and hydroperoxide lyase (HPL) are responsible for production of the signaling compounds, jasmonates and aldehydes respectively. Here, we compare and contrast the regulation of AOS and HPL branch pathways in rice and Arabidopsis as model monocotyledonous and dicotyledonous systems. These analyses provide new insights into the evolution of JAs and aldehydes signaling pathways, and the complex network of processes responsible for stress adaptations in monocots and dicots.
Phototropins and Their LOV Domains: Versatile Plant Blue‐Light Receptors
Authors: Briggs Winslow R. , Tseng Tong‐Seung , Cho Hae‐Young , Swartz Trevor E. , Sullivan Stuart , Bogomolni Roberto A. , Kaiserli Eirini , Christie John M.
Published: January 2007

The phototropins phot1 and phot2 are plant blue‐light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which it occurs. The phototropins are plasma membrane‐associated hydrophilic proteins with two chromophore domains (designated LOV1 and LOV2 for their resemblance to domains in other signaling proteins that detect light, oxygen, or voltage) in their N‐terminal half and a classic serine/threonine kinase domain in their C‐terminal half. Both chromophore domains bind flavin mononucleotide (FMN) and both undergo light‐activated formation of a covalent bond between a nearby cysteine and the C(4a) carbon of the FMN to form the signaling state. LOV2‐cysteinyl adduct formation leads to the release downstream of a tightly bound amphipathic α‐helix, a step required for activation of the kinase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light‐activated phosphorylation and for various blue‐light responses mediated by the phototropins. The function of LOV1 is still unknown, although it may serve to modulate the signal generated by LOV2. The LOV domain is an ancient chromophore module found in a wide range of otherwise unrelated proteins in fungi and prokaryotes, the latter including cyanobacteria, eubacteria, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum (2005) and Christie and Briggs (2005).
Endless Hide‐and‐Seek: Dynamic Co‐evolution in Plant‐Bacterium Warfare
Authors: Shan Libo , He Ping , Sheen Jen
Published: January 2007

Plants possess innate immune systems to prevent most potential infections. The ancient and conserved innate immune responses are triggered by microbe‐associated molecular patterns (MAMPs) and play important roles in broad‐spectrum defenses. However, successful bacterial pathogens evolved type III virulence effectors to suppress MAMP‐mediated immunity. To survive, plants further developed highly specific resistance (R) genes to trigger gene‐for‐gene‐mediated immunity and turn the virulent pathogens into avirulent ones. We summarize here the very recent advances in this dynamic coevolution of plant‐bacterium interaction.
A Role for Auxin in Flower Development
Authors: Cheng Youfa , Zhao Yunde
Published: January 2007

Auxin has long been implicated in many aspects of plant growth and development including flower development. However, the exact roles of auxin in flower development have not been well defined until the recent identification of auxin biosynthesis mutants. Auxin is necessary for the initiation of floral primordia, and the disruption of auxin biosynthesis, polar auxin transport or auxin signaling leads to the failure of flower formation. Auxin also plays an essential role in specifying the number and identity of floral organs. Further analysis of the relationship between the auxin pathways and the known flower development genes will provide critical information regarding mechanisms of organogenesis and pattern formation in plants.
Jasmonate Signal Pathway in Arabidopsis
Authors: Shan Xiao‐Yi , Wang Zhi‐Long , Xie Daoxin
Published: January 2007

Jasmonates (JAs), which include jasmonic acid and its cyclopentane derivatives are synthesized from the octadecanoid pathway and widely distributed throughout the plant kingdom. JAs modulate the expression of numerous genes and mediate responses to stress, wounding, insect attack, pathogen infection, and UV damage. They also affect a variety of processes in many plant developmental processes. The JA signal pathway involves two important events: the biosynthesis of JA and the transduction of JA signal. Several important Arabidopsis mutants in jasmonate signal pathway were described in this review.
Ubiquitination in Abscisic Acid‐Related Pathway
Authors: Zhang Yi‐Yue , Xie Qi
Published: January 2007

Ubiquitination is emerging as a tight regulatory mechanism that is necessary for all aspects of development and survival of all eukaryotes. Recent genomic and genetic analysis in Arabidopsis suggests that ubiquitination may also play important roles in plant response to the phytohormone abscisic acid (ABA). Many components of the ubiquitination pathway, such as ubiquitin‐conjugating enzyme E2, ubiquitin ligase E3 and components of the proteasome, have been identified or predicted to be essential in ABA biosynthesis, catabolism and signaling. In addition, the ubiquitination‐related pathway, sumoylation, is also involved in ABA signaling. We summarize in this report recent developments to elucidate their roles in the ABA‐related pathway.
Roles of Pectin Methylesterases in Pollen‐Tube Growth
Authors: Chen Li‐Qun , Ye De
Published: January 2007

Elongation of the pollen tube in pistil is essential for delivering sperms into the female gametophyte in sexual plant reproduction. Recently, a group of cell wall enzymes, pectin methylesterases (PMEs), have been identified as playing an important role in this process. This article reviews the new understanding of the roles of PMEs in regulating pollen tube growth.
Characterization of the Ubiquitin E2 Enzyme Variant Gene Family in Arabidopsis
Authors: Zhang Yu , Wen Pei , Lau On‐Sun , Deng Xing‐Wang
Published: January 2007

Ubiquitin E2 enzyme variant (UEV) proteins are similar to ubiquitin‐conjugating enzyme (E2) in both sequence and structure, but the lack of a catalytic cysteine residue renders them incapable of forming a thiol‐ester linkage with ubiquitin. While the functional roles of several UEVs have been defined in yeast and animal systems, Arabidopsis COP10, a photomorphogenesis repressor, is the only UEV characterized in plants. Phylogenetic analysis revealed that the eight Arabidopsis UEV genes belong to three subfamilies. The expression of those genes is supported by either the presence of ESTs or RT‐PCR analysis. We also characterized the other members of the COP10 subfamily, UEV2. Semi‐quantitative RT‐PCR analysis indicated that the UEV2 transcripts can be detected in most organs of Arabidopsis. Analysis of UEV2::GUS transgenic lines also showed its ubiquitous expression in nearly all the developmental stages of Arabidopsis. Transient expression analysis indicated that the sGFP‐UEV2 fusion protein can localize to both the cytoplasm and nucleus. A T‐DNA insertion mutant, uev2‐1, which abolished the transcription of UEV2, displays no visible phenotype. Further, the cop10‐4 uev2‐1 double mutant exhibits the same phenotype as the cop10‐4 mutant in darkness. UEV2 is therefore not functionally redundant with COP10.
Barriers to immunizations: Multiethnic parents of under‐ and unimmunized children speak
Authors: Niederhauser Victoria P. , Markowitz Malama
Published: January 2007

Purpose: Childhood immunizations are one of the greatest pubic health success stories. Despite the fact that many children receive immunizations according to the recommended schedule, there are many that lag behind. The purpose of this study was to explore the barriers to immunizations in parents whose children are not fully immunized by age 2.

Data source: Thirteen focus groups, on four different islands (Oahu, Kauai, Maui, Hawaii) were held with a total of 64 parents. Verbatim transcripts were utilized for content analysis.

Conclusion: Five core themes emerged as barriers to childhood immunizations, parental, transportation, financial, child, and organization. The majority of responses were in the parental core theme, which included the sub‐themes of issues, beliefs, knowledge, and fears.

Implications for practice: Recommendations included identification of specific barriers to target immunization interventions strategies, public policy changes, identification and case management of high risk families, and minimization of organizational barriers.
Provisioning calls of the cooperatively breeding bell miner Manorina melanophrys encode sufficient information for individual discrimination
Authors: G. McDonald Paul , F. Heathcote Catherine , F. Clarke Michael , Wright Jonathan , J. N. Kazem Anahita
Published: January 2007

Acoustically‐mediated individual discrimination has been the focus of much investigation in ornithology. For cooperatively breeding species, strong selection pressure favouring individual recognition during acts of altruism is predicted under many of the most interesting hypotheses proposed to account for helping behaviour. We investigated differences in 157 calls given by 12 different individuals as they provisioned nestlings, including both breeding and helper bell miners Manorina melanophrys (Meliphagidae), a cooperatively breeding honeyeater endemic to south‐eastern Australia. Individual differences were apparent in all 15 call parameters analysed, many with a high level of repeatability. Moreover, the information capacity of mew calls allows as many as 515 different signatures to exist in the system. As many parameters showed strong sex differences, separate discriminant functions were used to predict individual identity within each sex. Five parameters were used in a function that correctly identified over 90% of female calls in both a training (n=35) and test dataset (n=11) not used to generate the function. Among males, a separate function used six parameters to correctly assign individual identity in 89.3% (n=84; training) and 77.8% (n=27; test) of cases. Three original parameters, including spectral and spatial characteristics, were highly correlated with functions predicting identity in both sexes. The accuracy of functions was not influenced by a signaller's sex, breeding status, or by sampling period which was spread over as much as two breeding seasons within individuals. Significant potential therefore exists for bell miners to use these simple provisioning calls in individual discrimination. If this is the case, call information also has the potential to be used by receivers as predicted by signalling hypotheses proposed to account for cooperative helping behaviour, such as the pay‐to‐stay and social prestige hypotheses.
Egg quality and parental ornamentation in the blue tit Parus caeruleus
Authors: Szigeti Beáta , Török János , Hegyi Gergely , Rosivall Balázs , Hargitai Rita , Szõllõsi Eszter , Michl Gábor
Published: January 2007

Components of avian egg quality often show remarkable variation between females and yet the causes of variation in this fitness‐related trait remain poorly understood. We investigated the egg size and yolk carotenoid investment of blue tit Parus caeruleus females in relation to multiple parental traits. We show that females produce eggs with more colourful yolks when mated to ultraviolet (UV) attractive males. Since yolk carotenoids may enhance offspring fitness, but may be available to females in limiting amounts, the correlation we found suggests adaptive egg quality adjustment in response to mate attractiveness, but an experimental approach is required to rule out alternative explanations. Yolk colour was also correlated with laying date and yolk mass. Though the effect of laying date could not be explained by ambient temperature during egg formation, it suggests a proximate constraint of general carotenoid availability on yolk composition. Egg size was not affected by male attractiveness; however, females with a brighter crown produced larger eggs, suggesting that crown coloration might indicate individual quality in females too.
The Effect of Hot-Streaks on HP Vane Surface and Endwall Heat Transfer: An Experimental and Numerical Study
Authors: Povey T. , Chana K. S. , Jones T. V. , Hurrion J.
Published: January 2007

Pronounced nonuniformities in combustor exit flow temperature (hot-streaks), which arise because of discrete injection of fuel and dilution air jets within the combustor and because of endwall cooling flows, affect both component life and aerodynamics. Because it is very difficult to quantitatively predict the effects of these temperature nonuniformities on the heat transfer rates, designers are forced to budget for hot-streaks in the cooling system design process. Consequently, components are designed for higher working temperatures than the mass-mean gas temperature, and this imposes a significant overall performance penalty. An inadequate cooling budget can lead to reduced component life. An improved understanding of hot-streak migration physics, or robust correlations based on reliable experimental data, would help designers minimize the overhead on cooling flow that is currently a necessity. A number of recent research projects sponsored by a range of industrial gas turbine and aero-engine manufacturers attest to the growing interest in hot-streak physics. This paper presents measurements of surface and endwall heat transfer rate for a high-pressure (HP) nozzle guide vane (NGV) operating as part of a full HP turbine stage in an annular transonic rotating turbine facility. Measurements were conducted with both uniform stage inlet temperature and with two nonuniform temperature profiles. The temperature profiles were nondimensionally similar to profiles measured in an engine. A difference of one-half of an NGV pitch in the circumferential (clocking) position of the hot-streak with respect to the NGV was used to investigate the affect of clocking on the vane surface and endwall heat transfer rate. The vane surface pressure distributions, and the results of a flow-visualization study, which are also given, are used to aid interpretation of the results. The results are compared to two-dimensional predictions conducted using two different boundary layer methods. Experiments were conducted in the Isentropic Light Piston Facility (ILPF) at QinetiQ Farnborough, a short-duration engine-sized turbine facility. Mach number, Reynolds number, and gas-to-wall temperature ratios were correctly modeled. It is believed that the heat transfer measurements presented in this paper are the first of their kind.
Experimental Evaluation of Active Flow Control Mixed-Flow Turbine for Automotive Turbocharger Application
Authors: Pesiridis Apostolos , Martinez-Botas Ricardo F.
Published: January 2007

In the current paper we introduce an innovative new concept in turbochargers—that of using active control at the turbine inlet with the aim of harnessing the highly dynamic exhaust gas pulse energy emanating at high frequency from an internal combustion engine, in order to increase the engine power output and reduce its exhaust emissions. Driven by the need to comply to increasingly strict emissions regulations as well as continually striving for better overall performance, the active control turbocharger is intended to provide a significant improvement over the current state of the art in turbocharging: the Variable Geometry Turbocharger (VGT). The technology consists of a system and method of operation, which regulate the inlet area to a turbocharger inlet, according to each period of engine exhaust gas pulse pressure fluctuation, thereby actively adapting to the characteristics of the high frequency, highly dynamic flow, thus taking advantage of the highly dynamic energy levels existent through each pulse, which the current systems do not take advantage of. In the Active (Flow) Control Turbocharger (ACT) the nozzle is able to adjust the inlet area at the throat of the turbine inlet casing through optimum amplitudes, at variable out-of-phase conditions and at the same frequency as that of the incoming exhaust stream pulses. Thus, the ACT makes better use of the exhaust gas energy of the engine than a conventional VGT. The technology addresses, therefore, for the first time the fundamental problem of the poor generic engine-turbocharger match, since all current state of the art systems in turbocharging are still passive receivers of this highly dynamic flow without being able to provide optimum turbine inlet geometry through each exhaust gas pulse period. The numerical simulation and experimental work presented in this paper concentrates on the potential gain in turbine expansion ratio and eventual power output as well as the corresponding effects on efficiency as a result of operating the turbocharger in its active control mode compared to its operation as a standard VGT.
Comparative Study of 2,4-Dichlorophenol Degradation With Different Advanced Oxidation Processes
Authors: Bayarri B. , González O. , Maldonado M. I. , Giménez J. , Esplugas S.
Published: January 2007

Chlorophenols (CPs) are toxic nonbiodegradable pollutants. In recent decades, several alternative processes for the treatment of these compounds have been investigated. Advanced Oxidation Processes (AOPs) are some of the most promising technologies. Among them, the UV-based AOPs [O3+Fe(II)+UV, photo-Fenton, UV+Fe(III), UV+H2O2, photocatalysis and photolysis] have previously been studied for the degradation of 2,4-dichlorophenol (DCP) in an aqueous solution at laboratory scale. In this paper, these techniques are compared and kinetic constants and pseudoquantum yields are estimated. O3−+Fe(II)+UV and photo-Fenton seem to be the most effective. To study scale-up of these processes from the laboratory to a pilot plant operating with sunlight, equivalent photocatalytic experiments were carried out in such installations. The results are promising and show trends similar to those obtained in the laboratory with lamps. The data obtained have been used to calculate some scale-up factors, which have been employed to make a rough estimation of the amount of waste water that can be treated by the solar AOPs studied. The results obtained are encouraging and prove the feasibility of this type of technology.