bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biosynthesis of plant-specific stilbene polyketides in metabolically engineered Escherichia coli
Authors: Watts Kevin T , Lee Pyung C , Schmidt-Dannert Claudia 
Published: April 2006

Abstract

Background
Phenylpropanoids are the precursors to a range of important plant metabolites such as the cell wall constituent lignin and the secondary metabolites belonging to the flavonoid/stilbene class of compounds. The latter class of plant natural products has been shown to function in a wide range of biological activities. During the last few years an increasing number of health benefits have been associated with these compounds. In particular, they demonstrate potent antioxidant activity and the ability to selectively inhibit certain tyrosine kinases. Biosynthesis of many medicinally important plant secondary metabolites, including stilbenes, is frequently not very well understood and under tight spatial and temporal control, limiting their availability from plant sources. As an alternative, we sought to develop an approach for the biosynthesis of diverse stilbenes by engineered recombinant microbial cells.

Results
A pathway for stilbene biosynthesis was constructed in Escherichia coli with 4-coumaroyl CoA ligase 1 4CL1) from Arabidopsis thaliana and stilbene synthase (STS) cloned from Arachis hypogaea. E. coli cultures expressing these enzymes together converted the phenylpropionic acid precursor 4-coumaric acid, added to the growth medium, to the stilbene resveratrol (>100 mg/L). Caffeic acid, added in the same way, resulted in the production of the expected dihydroxylated stilbene, piceatannol (>10 mg/L). Ferulic acid, however, was not converted to the expected stilbene product, isorhapontigenin. Substitution of 4CL1 with a homologous enzyme, 4CL4, with a preference for ferulic acid over 4-coumaric acid, had no effect on the conversion of ferulic acid. Accumulation of tri- and tetraketide lactones from ferulic acid, regardless of the CoA-ligase expressed in E. coli, suggests that STS cannot properly accommodate and fold the tetraketide intermediate to the corresponding stilbene structure.

Conclusion
Phenylpropionic acids, such as 4-coumaric acid and caffeic acid, can be efficiently converted to stilbene compounds by recombinant E. coli cells expressing plant biosynthetic genes. Optimization of precursor conversion and cyclization of the bulky ferulic acid precursor by host metabolic engineering and protein engineering may afford the synthesis of even more structurally diverse stilbene compounds.
Female genital mutilation of a karyotypic male presenting as a female with delayed puberty
Authors: Ellaithi M , Nilsson T , Gisselsson D , Elagib A , Eltigani H , Fadl-Elmula I 
Published: April 2006

Abstract

Background
Female genital mutilation (FGM) is commonly practiced mainly in a belt reaching from East to West Africa north of the equator. The practice is known across socio-economic classes and among different ethnic, religious, and cultural groups. Few studies have been appropriately designed to measure the health effects of FGM. However, the outcome of FGM on intersex individuals has never been discussed before.

Case presentation
The patient first presented as a female with delayed puberty. Hormonal analysis revealed a normal serum prolactin level of 215 Mu/L, a low FSH of 0.5 Mu/L, and a low LH of 1.1 Mu/L. Type IV FGM (Pharaonic circumcision) had been performed during childhood. Chromosomal analysis showed a 46, XY karyotype and ultrasonography verified a soft tissue structure in the position of the prostate.

Conclusion
FGM pose a threat to the diagnosis and management of children with abnormal genital development in the Sudan and similar societies.
Community wide electronic distribution of summary health care utilization data
Authors: Lagoe Ronald J , Westert Gert P 
Published: April 2006

Abstract

Background
In recent years, the use of digital technology has supported widespread sharing of electronic health care data. Although this approach holds considerable promise, it promises to be a complicated and expensive undertaking. This study described the development and implementation of a community wide system for electronic sharing of summary health care utilization data.

Methods
The development of the community wide data system focused on the following objectives: ongoing monitoring of the health care system, evaluation of community wide individual provider initiatives, identification and development of new initiatives.
The system focused on the sharing of data related to hospital acute care, emergency medical services, long term care, and mental health. It was based on the daily distribution of reports among all health care providers related to these services.

Results
The development of the summary reports concerning health care utilization produced a system wide view of health care in Syracuse, New York on a daily basis. It was not possible to isolate the results of these reports because of the impact of specific projects and other factors. At the same time, the reports were associated with reduction of hospital inpatient stays, improvement of access to hospital emergency departments, reductions in stays for patients discharged to nursing homes, and increased access of mental health patients to hospital inpatient units.

Conclusion
The implementation of the system demonstrated that summary electronic utilization data could provide daily information that would support the improvement of health care outcomes and efficiency. This approach could be implemented in a simple, direct manner with minimal expenses.
Impact of treatment policies on patient outcomes and resource utilization in acute cholecystitis in Japanese hospitals
Authors: Sekimoto Miho , Imanaka Yuichi , Hirose Masahiro , Ishizaki Tatsuro , Murakami Genki , Fukata Yushi ,   QIP Cholecystectomy Expert Group
Published: April 2006

AbstractBackgroundAlthough currently available evidence predominantly recommends early laparoscopic cholecystectomy (LC) for the treatment of acute cholecystitis, this strategy has not been widely adopted in Japan. Herein, we describe a hospital-based study of patients with acute cholecystitis in 9 Japanese teaching hospitals in order to evaluate the impact of different institutional strategies in treating acute cholecystitis on overall patient outcomes and medical resource utilization.MethodsFrom an administrative database and chart review, we identified 228 patients diagnosed with acute cholecystitis who underwent cholecystectomy between April 2001 and June 2003. In order to examine the relationship between hospitals' propensity to perform LC and patient outcomes and/or medical resource utilization, we divided the hospitals into three groups according to the observed to expected ratio of performing LC (LC propensity), and compared the postoperative complication rate, length of hospitalization (LOS), and medical charges.ResultsNo hospital adopted the policy of early surgery, and the mean overall LOS among the subjects was 30.9 days. The use of laparoscopic surgery varied widely across the hospitals; the adjusted rates of LC to total cholecystectomies ranged from 9.5% to 77%. Although intra-operative complication rate was significantly higher among patients whom LC was initially attempted when compared to those whom OC was initially attempted (9.7% vs. 0%), there was no significant association between LC propensity and postoperative complication rates. Although the postoperative time to oral intake and postoperative LOS was significantly shorter in hospitals with high use of LC, the overall LOS did not differ among hospital groups with different LC propensities. Medical charges were not associated with LC propensity.ConclusionUnder the prevailing policy of delayed surgery, in terms of the postoperative complication rate and medical resource utilization, our study did not show the superiority of LC in treating acute cholecystitis patients. The timing of surgery and discharge was mainly determined by the institutional policy in Japan, rather than by the clinical course of the patient; however, considering the substantially less postoperative pain and shorter recovery time of LC compared to OC, LC should be actively applied for the treatment of acute cholecystitis. If the policy of early surgery were universally applied, the advantage of LC over OC may be more clearly demonstrated.
Applications of cell sorting in biotechnology
Authors: Mattanovich Diethard , Borth Nicole 
Published: April 2006

Abstract
Due to its unique capability to analyze a large number of single cells for several parameters simultaneously, flow cytometry has changed our understanding of the behavior of cells in culture and of the population dynamics even of clonal populations. The potential of this method for biotechnological research, which is based on populations of living cells, was soon appreciated. Sorting applications, however, are still less frequent than one would expect with regard to their potential. This review highlights important contributions where flow cytometric cell sorting was used for physiological research, protein engineering, cell engineering, specifically emphasizing selection of overproducing cell lines. Finally conclusions are drawn concerning the impact of cell sorting on inverse metabolic engineering and systems biology.
Heterologous expression of Brucella abortus GroEL heat-shock protein in Lactococcus lactis
Authors: Miyoshi Anderson , Bermúdez-Humarán Luis G , Ribeiro Luciana A , Le Loir Yves , Oliveira Sérgio C , Langella Philippe , Azevedo Vasco 
Published: April 2006

AbstractBackgroundBrucella abortusis a facultative intracellular pathogen that mainly infects cattle and humans. Current vaccines rely on live attenuated strains ofB. abortus, which can revert to their pathogenic status and thus are not totally safe for use in humans. Therefore, the development of mucosal live vaccines using the food-grade lactic acid bacterium,Lactococcus lactis, as an antigen delivery vector, is an attractive alternative and a safer vaccination strategy againstB. abortus. Here, we report the construction ofL. lactisstrains genetically modified to produceB. abortusGroEL heat-shock protein, a candidate antigen, in two cellular locations, intracellular or secreted.ResultsOnly the secreted form of GroEL was stably produced inL. lactis, suggesting a detrimental effect of GroEL protein when intracellularly produced in this bacterium. Only trace amounts of mature GroEL were detected in the supernatant fraction of induced lactococcal cultures, and the GroEL precursor remained stacked in the cell fraction. Attempts to raise the secretion yields were made, but even when GroEL was fused to a synthetic propeptide, secretion of this antigen was not improved.ConclusionWe found thatL. lactisis able to produce, and to secrete, a stable form of GroEL into the extracellular medium. Despite the low secretion efficiency of GroEL, which suggest that this antigen interacts with the cell envelope ofL. lactis, secretion seems to be the best way to achieve both production and protein yields, regardless of cellular location. TheL. lactisstrain secreting GroEL has potential forin vivoimmunization.
Coordinate regulation of fibronectin matrix assembly by the plasminogen activator system and vitronectin in human osteosarcoma cells
Authors: Vial Daniel , Monaghan-Benson Elizabeth , McKeown-Longo Paula J 
Published: April 2006

Abstract

Background
Plasminogen activators are known to play a key role in the remodeling of bone matrix which occurs during tumor progression, bone metastasis and bone growth. Dysfunctional remodeling of bone matrix gives rise to the osteoblastic and osteolytic lesions seen in association with metastatic cancers. The molecular mechanisms responsible for the development of these lesions are not well understood. Studies were undertaken to address the role of the plasminogen activator system in the regulation of fibronectin matrix assembly in the osteoblast-like cell line, MG-63.

Results
Treatment of MG-63 cells with P25, a peptide ligand for uPAR, resulted in an increase in assembly of fibronectin matrix which was associated with an increase in the number of activated β1 integrins on the cell surface. Overexpression of uPAR in MG-63 cells increased the effect of P25 on fibronectin matrix assembly and β1 integrin activation. P25 had no effect on uPAR null fibroblasts, confirming a role for uPAR in this process. The addition of plasminogen activator inhibitor Type I (PAI-1) to cells increased the P25-induced fibronectin polymerization, as well as the number of activated integrins. This positive regulation of PAI-1 on fibronectin assembly was independent of PAI-1's anti-proteinase activity, but acted through PAI-1 binding to the somatomedin B domain of vitronectin.

Conclusion
These results indicate that vitronectin modulates fibronectin matrix assembly in osteosarcoma cells through a novel mechanism involving cross-talk through the plasminogen activator system.
The distribution of hatching time in Anopheles gambiae
Authors: Yaro Alpha S , Dao Adama , Adamou Abdoulaye , Crawford Jacob E , Ribeiro José MC , Gwadz Robert , Traoré Sekou F , Lehmann Tovi 
Published: April 2006

Abstract

Background
Knowledge of the ecological differences between the molecular forms of Anopheles gambiae and their sibling species, An. arabiensis might lead to understanding their unique contribution to disease transmission and to better vector control as well as to understanding the evolutionary forces that have separated them.

Methods
The distributions of hatching time of eggs of wild An. gambiae and An. arabiensis females were compared in different water types. Early and late hatchers of the S molecular form were compared with respect to their total protein content, sex ratio, development success, developmental time and adult body size.

Results
Overall, the distribution of hatching time was strongly skewed to the right, with 89% of the eggs hatching during the second and third day post oviposition, 10% hatching during the next four days and the remaining 1% hatching over the subsequent week. Slight, but significant differences were found between species and between the molecular forms in all water types. Differences in hatching time distribution were also found among water types (in each species and molecular form), suggesting that the eggs change their hatching time in response to chemical factors in the water. Early hatchers were similar to late hatchers except that they developed faster and produced smaller adults than late hatchers.

Conclusion
Differences in hatching time and speed of development among eggs of the same batch may be adaptive if catastrophic events such as larval site desiccation are not rare and the site's quality is unpredictable. The egg is not passive and its hatching time depends on water factors. Differences in hatching time between species and molecular forms were slight, probably reflecting that conditions in their larval sites are rather similar.
Movies of cellular and sub-cellular motion by digital holographic microscopy
Authors: Mann Christopher J , Yu Lingfeng , Kim Myung K 
Published: April 2006

Abstract

Background
Many biological specimens, such as living cells and their intracellular components, often exhibit very little amplitude contrast, making it difficult for conventional bright field microscopes to distinguish them from their surroundings. To overcome this problem phase contrast techniques such as Zernike, Normarsky and dark-field microscopies have been developed to improve specimen visibility without chemically or physically altering them by the process of staining. These techniques have proven to be invaluable tools for studying living cells and furthering scientific understanding of fundamental cellular processes such as mitosis. However a drawback of these techniques is that direct quantitative phase imaging is not possible. Quantitative phase imaging is important because it enables determination of either the refractive index or optical thickness variations from the measured optical path length with sub-wavelength accuracy.
Digital holography is an emergent phase contrast technique that offers an excellent approach in obtaining both qualitative and quantitative phase information from the hologram. A CCD camera is used to record a hologram onto a computer and numerical methods are subsequently applied to reconstruct the hologram to enable direct access to both phase and amplitude information. Another attractive feature of digital holography is the ability to focus on multiple focal planes from a single hologram, emulating the focusing control of a conventional microscope.

Methods
A modified Mach-Zender off-axis setup in transmission is used to record and reconstruct a number of holographic amplitude and phase images of cellular and sub-cellular features.

Results
Both cellular and sub-cellular features are imaged with sub-micron, diffraction-limited resolution. Movies of holographic amplitude and phase images of living microbes and cells are created from a series of holograms and reconstructed with numerically adjustable focus, so that the moving object can be accurately tracked with a reconstruction rate of 300ms for each hologram. The holographic movies show paramecium swimming among other microbes as well as displaying some of their intracellular processes. A time lapse movie is also shown for fibroblast cells in the process of migration.

Conclusion
Digital holography and movies of digital holography are seen to be useful new tools for visualization of dynamic processes in biological microscopy. Phase imaging digital holography is a promising technique in terms of the lack of coherent noise and the precision with which the optical thickness of a sample can be profiled, which can lead to images with an axial resolution of a few nanometres.
Dominant negative retinoic acid receptor initiates tumor formation in mice
Authors: Kupumbati Tara S , Cattoretti Giorgio , Marzan Christine , Farias Eduardo F , Taneja Reshma , Mira-y-Lopez Rafael 
Published: April 2006

Abstract

Background
Retinoic acid suppresses cell growth and promotes cell differentiation, and pharmacological retinoic acid receptor (RAR) activation is anti-tumorigenic. This begs the question of whether chronic physiological RAR activation by endogenous retinoids is likewise anti-tumorigenic.

Results
To address this question, we generated transgenic mice in which expression of a ligand binding defective dominant negative RARα (RARαG303E) was under the control of the mouse mammary tumor virus (MMTV) promoter. The transgene was expressed in the lymphoid compartment and in the mammary epithelium. Observation of aging mice revealed that transgenic mice, unlike their wild type littermates, developed B cell lymphomas at high penetrance, with a median latency of 40 weeks. MMTV-RARαG303E lymphomas were high grade Pax-5+, surface H+L Ig negative, CD69+ and BCL6- and cytologically and phenotypically resembled human adult high grade (Burkitt's or lymphoblastic) lymphomas. We postulated that mammary tumors might arise after a long latency period as seen in other transgenic models of breast cancer. We tested this idea by transplanting transgenic epithelium into the cleared fat pads of wild type hosts, thus bypassing lymphomagenesis. At 17 months post-transplantation, a metastatic mammary adenocarcinoma developed in one of four transplanted glands whereas no tumors developed in sixteen of sixteen endogenous glands with wild type epithelium.

Conclusion
These findings suggest that physiological RAR activity may normally suppress B lymphocyte and mammary epithelial cell growth and that global RAR inactivation is sufficient to initiate a stochastic process of tumor development requiring multiple transforming events. Our work makes available to the research community a new animal resource that should prove useful as an experimental model of aggressive sporadic lymphoma in immunologically uncompromised hosts. We anticipate that it may also prove useful as a model of breast cancer.
Prognostic significance of new onset ascites in patients with pancreatic cancer
Authors: Zervos Emmanuel E , Osborne Dana , Boe Brian A , Luzardo German , Goldin Steven B , Rosemurgy Alexander S 
Published: April 2006

Abstract

Background
The purpose of this study was to determine risk factors for development of malignant ascites and its prognostic significance in patients with pancreatic cancer.

Methods
A prospective database was queried to identify patients with pancreatic cancer who develop ascites. Stage at presentation, size, and location of primary tumor, treatment received and length of survival after onset of ascites were determined.

Results
A total of 15 patients were identified. Of which 4 patients (1 stage II, 3 stage III) underwent pancreaticoduodenectomy and manifested with ascites 2, 3, 24 and 47 months after surgery (tumor size 2.9 ± 1.32 cm). All but one of the remaining 11 patients (tumor size 4.4 ± 3.38 cm) presented with metastatic disease, and all developed malignant ascites 9 months after diagnosis, dying 2 months later. Resected patients lived longer before the onset of ascites, but not after.

Conclusion
Once diagnosed, ascites in pancreatic cancer patients heralds imminent death. Limited survival should be considered when determining the aggressiveness of further intervention.
Ten year survival after excision of squamous cell cancer in Zenker's diverticulum: report of a case
Authors: Dionigi Gianlorenzo , Sessa Fausto , Rovera Francesca , Boni Luigi , Carrafiello Gianpaolo , Dionigi Renzo 
Published: April 2006

Abstract

Background
Zenker's diverticulum (ZD) has been increasingly recognized as a site of primary epithelial malignancy. Pitt in 1896 described the first case.

Methods
Between 1990 and 2005, 30 patients affected of esophageal diverticulum were referred to our Department.

Results
The pathological results revealed one case of squamous cell carcinoma. On follow-up 10 years after diverticulectomy alone, the patient was alive and well without evidence of recurrence.

Conclusion
Our case reported provides additional data on clinical decision when the tumor is well localized without full-thickness penetration or extension to the line of resection. In this patient, long-term survival and apparent disease control have been effected by diverticulectomy alone. A case of such long survival is very rare.