bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of conventional sunflower cultivars to drift rates of synthetic auxin herbicides
Authors: Serim Ahmet Tansel , Patterson Eric L.
Published: January 2024

The agrochemical industry has launched several new synthetic auxin herbicides in rice to combat increasing numbers of herbicide resistant weeds to other modes of action. Excessive or inappropriate use of these herbicides has resulted in unintended consequences near the sites of application, such as herbicide drift. This study was conducted to determine the impact of drift of quinclorac and florpyrauxifen-benzyl+penoxsulam (FBP) on the yield and yield components of two sunflower cultivars. In a growth chamber experiment, quinclorac and FBP were applied to 2–4 true leaf stages at rates ranging from 2.93 to 93.75 and from 0.51 to 16.25 g ai ha−1, respectively. Nonlinear regression analyses indicated that the cultivar Bosfora was more sensitive to quinclorac and FBP than the cultivar Tunca. In field experiments, these sunflower cultivars were treated with drift rates of quinclorac (<375 g ai ha−1) and FBP (<65 g ai ha−1) when they were at the 8-10 true leaf stage. Quinclorac and FBP drift rates resulted in up to 52-61% and 85–100% injury and 82-88% and 100% yield loss, respectively. Crop injury and yield data clearly showed that cultivar Bosfora was more sensitive to FBP and quinclorac rates than cultivar Tunca, and both cultivars were more sensitive to FBP than quinclorac. In our work, we also found that plant height reduction caused by quinclorac at early growth stages may be a valuable indicator to evaluate crop injury and yield loss.
Enzymatic synthesis of amoxicillin: Avoiding limitations of the mechanistic approach for reaction kinetics
Authors: Gonçalves Luciana R.B. , Sousa Ruy , Fernandez‐Lafuente Roberto , Guisan Jose M. , Giordano Raquel L.C. , Giordano Roberto C.
Published: October 2002

A recurrent doubt that occurs to the enzyme‐kinetics modeler is, When should I stop adding parameters to my mechanistic model in order to fit a non‐conventional behavior? This problem becomes more and more involving when the complexity of the reaction network increases. This work intends to show how the use of artificial neural networks may circumvent the need of including an overwhelming number of parameters in the rate equations obtained through the classical, mechanistic approach. We focus on the synthesis of amoxicillin by the reaction of p‐OH‐phenylglycine methyl ester and 6‐aminopenicillanic acid, catalyzed by penicillin G acylase immobilized on glyoxyl‐agarose, at 25°C and pH 6.5. The reaction was carried on a batch reactor. Three kinetic models of this system were compared: a mechanistic, a semi‐empiric, and a hybrid–neural network (NN). A semi‐empiric, simplified model with a reasonable number of parameters was initially built‐up. It was able to portray many typical process conditions. However, it either underestimated or overestimated the rate of synthesis of amoxicillin when substrates' concentrations were low. A more complex, full‐scale mechanistic model that could span all operational conditions was intractable for all practical purposes. Finally, a hybrid model, that coupled artificial neural networks (NN) to mass‐balance equations was established, that succeeded in representing all situations of interest. Particularly, the NN could predict with accuracy reaction rates for conditions where the semi‐empiric model failed, namely, at low substrate concentrations, a situation that would occur, for instance, at the end of a fed‐batch industrial process. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 622–631, 2002.
Performance analysis of dynamic channel assignment algorithms in cellular mobile systems with hand‐off
Authors: Cong L. , Gunawan E. , Soh C. B. , Soong B. H. , Tan P. T. , Weng W.
Published: October 2002

In this paper, the traffic performance of dynamic channel assignment (DCA) in cellular mobile system with hand‐off is investigated. A traffic model for cellular system incorporating hand‐off is established first. Under the framework of the model, a hand‐off priority scheme is developed to reduce the forced termination of calls in progress. This paper analyses and derives the traffic performance bound for DCA strategies with hand‐off by extending the maximum packing (MP) scheme to include the hand‐off procedure. For practical implementation, a distributed DCA algorithm (DDCA) is also proposed. A non‐priority scheme and the proposed priority scheme can be combined with either MP or DDCA. It is shown that the simulation results of DDCA scheme are comparable with the analytical bounds given by MP for both the non‐prioritized case and prioritized case. A reasonable trade‐off between the new call blocking probability and forced termination probability can be achieved by using the proposed prioritized scheme in DCA. Copyright © 2002 John Wiley & Sons, Ltd.
The use of fly ash from the combustion of poultry litter for the adsorption of chromium(III) from aqueous solution
Authors: Kelleher Brian P , O'Callaghan Marguerite N , Leahy Martin J , O'Dwyer Thomas F , Leahy J J
Published: October 2002

Fly ash, from the combustion of poultry litter, was assessed as an adsorbent for chromium(III) from aqueous solution. The adsorption process was studied as a function of temperature and time. Adsorption was best described by the Langmuir model. The adsorption of chromium(III) on the fly ash was endothermic and kinetic studies suggest that the overall rate of adsorption was pseudo‐second order. At low initial concentrations film diffusion effects contribute to limiting the overall rate of adsorption while at higher initial chromium(III) concentrations pore diffusion becomes more important. An adsorption capacity of 53 mg dm−3 was reached at 20 °C.

© 2002 Society of Chemical Industry
Extraction of aconitic acid from mixtures of organic acids and cane molasses solutions using supported liquid membranes
Authors: McMurray Scott Herbert , Griffin Gregory John
Published: October 2002

This paper details experimental trials of aconitic acid transport from defined mixtures of organic acids (trans‐aconitic, oxalic, malic and citric) and from cane molasses solutions using a supported liquid membrane (SLM) apparatus. The SLM was impregnated with tributyl phosphate extractant combined with Shellsol 2046 diluent. The transport rates of the organic acids, bulk impurities and glucose were measured. The conditions varied were: extractant to diluent ratio (1:3–3:1), organic acid concentration (2.5–40 mg cm−3 organic acid), pH of departure phase (1–5.5) and temperature (22–80 °C). Results for the organic acid mixtures showed that aconitic acid and oxalic acid were transported at much greater rates than malic and citric acids. Aconitic acid was transported to a significant degree with recovery of 400 g kg−1 over a 24 h period. Operation at temperatures higher than 22 °C caused instability of the membrane and bulk leakage across the membrane. With molasses, the purity of the aconitic acid recovered ranged between 400 and 600 g kg−1 (dry basis) with aconitic acid transport rates of 0.17–0.25 g m−2 min−1. The extraction of other acids (oxalic, malic and citric) and impurities was significantly less, hence a process to produce high purity aconitic acid based on this method is technically feasible.

© 2002 Society of Chemical Industry
Prenatal detection of a cystic fibrosis mutation in fetal DNA from maternal plasma
Authors: González‐González M. C. , García‐Hoyos M. , Trujillo M.J. , Rodríguez de Alba M. , Lorda‐Sánchez I. , Díaz‐Recasens J. , Gallardo E. , Ayuso C. , Ramos C.
Published: October 2002

Objectives

Maternal plasma and serum are being used to detect fetal DNA by PCR in order to determine certain conditions such as fetal gender and RhD without invasive procedures. Because of the presence of maternal DNA in plasma, these approaches are limited to paternally inherited disorders or those de novo present in the fetus. We have assessed the possibility of performing the detection of a single‐gene disorder such as a fetal paternally inherited Cystic Fibrosis mutation (Q890X) in maternal plasma.

Methods

The analysis was performed at 13 weeks of gestation using DNA extracted from maternal plasma. We used a PCR amplification of the Q890X mutation and a posterior restriction analysis of the PCR product.

Results

We were able to detect the presence of the mutation and thus the fetal condition of being a carrier of the paternal mutation.

Conclusions

We have made evident the possibility of detecting an inherited paternal mutation in a non‐invasive way at the 13thr weeks of pregnancy. This methodology could be very useful in cases of paternally inherited dominant disorders. The technical improvements in fetal DNA detection and analysis might lead to the development of new applications in the non‐invasive prenatal diagnosis field. Copyright © 2002 John Wiley & Sons, Ltd.
Crystalline silicon photovoltaic modules: characterization in the field of rural electrification
Authors: Caamaño‐Martín E. , Lorenzo E. , Lastres C.
Published: October 2002

The need to characterise photovoltaic modules in the general field of ensuring technical quality in photovoltaic rural electrification (PVRE) has often been pointed out. The ongoing national PVRE initiatives announced world‐wide, together with the fact that PV modules with an actual power smaller than the nominal value can still be found on the market, make it advisable to apply systematic control to supplied power procedures. This paper argues that it is possible to carry out such control in the case of crystalline silicon PV modules, by means of experiments performed outdoors under a wide range of operation conditions, and using reduced and conventional equipment. A simple characterisation procedure specifically aimed at PVRE programmes is described and validated with an extensive experimental campaign. Copyright © 2002 John Wiley & Sons, Ltd.
Safety and risk in structural engineering
Authors: Melchers Robert E
Published: October 2002

Safety in structural engineering is an enduring issue with a long history. Extensive rules have been developed for its management, mainly for use at the design and construction stages, but are these sufficient? Increasingly, ageing, existing structures must be assessed for continued safety. Structures are part of much larger infrastructure systems and their failure may have significant system consequences. Emerging thinking suggests that for the realistic assessment of the safety of major structures, and hence the risks involved in their failure, structural engineers will need to adopt a broad risk management perspective. This will mean the adaptation of tools and techniques drawn from risk management for other potentially hazardous facilities and used in conjunction with the well‐developed techniques unique to structural reliability analysis.

Major structural engineering projects may be categorized as being ‘low‐probability—high‐consequence’ types of risk. This implies that philosophies and practices for such types of risk already developed for hazardous facilities in other industries ought to be adaptable to major structural engineering projects. It is argued that such risks have relevance also for acts of war, sabotage and terrorism, provided their assessment involves appropriate inputs. Difficult societal decision processes are involved, including the management of post‐failure scenarios.
Composite steel beams with precast hollow core slabs: behaviour and design
Authors: Lam Dennis
Published: October 2002

This article reviews the design and behaviour of composite beams with precast hollow core slabs in multi‐storey buildings for gravity loading. A brief history of composite construction and introduction to precast–composite construction is given, followed by an overview of recent research work on various factors affecting the design. This includes the push‐off test procedure, the load–slip characteristic of the headed shear studs and the design procedures for this type of construction. Finite element modelling of the headed stud shear connectors and the composite beams with precast hollow core slabs are presented. Finally, recommendations and future research work is also suggested.
Blast loading and building robustness
Authors: Smith P D , Rose T A
Published: October 2002

An overview of methods of blast load quantification and aspects of building design intended to reduce the damaging effects of explosions by increasing robustness is presented. Possible blast loading scenarios range from simple free‐air bursts, loading essentially isolated buildings, to complex urban environments, with road junctions and side streets, etc., where buildings have varying amounts of frangible facade. The blast loads resulting in these scenarios are radically different, with different aspects of the pressure load dominating the type and extent of building damage. Means of calculating these time‐varying pressure loads are described.

Achieving stand‐off between a vulnerable building and the source of an explosion is the single most important factor in reducing the blast load experienced by the building. Methods of achieving stand‐off in building design are discussed. The creation of adequate stand‐off may often not be possible, and the need for robust glazing systems is also essential if blast is to be keep out of buildings and contamination of the work‐place by broken glass is to be prevented. The use of laminated glass, anti‐shatter film and other measures is discussed.

Existing buildings pose particular problems to engineers concerned with their protection. Several methods of strengthening or increasing the effective mass of existing buildings are described.
Quality of Life, Surgical Outcome, and Patient Satisfaction Three Years after Laparoscopic Nissen Fundoplication
Authors: Granderath Frank A. , Kamolz Thomas , Schweiger Ursula M. , Pointner Rudolph
Published: October 2002

Quality of life data and patient satisfaction are important issues in estimating the outcome of laparoscopic antireflux surgery (LARS). Long‐term of quality of life assessment has not yet received wide attention. The aim of this prospective study was to evaluate surgical outcome, including quality of life and patient satisfaction, after laparoscopic "floppy"
Nissen fundoplication up to 3 years after surgery. Between 1994 and
1996, a total of 150 consecutive patients with severe gastroesophageal reflux disease underwent laparoscopic "floppy" Nissen fundoplication. Quality of life was evaluated using the Gastrointestinal Quality of Life Index (GIQLI). The GIQLI questionnaire was given to the patients prior to surgery, and again 3 months, 1 year,
and 3 years postoperatively. In addition, 24‐hour pH monitoring and esophageal manometry were performed preoperatively and at each follow‐up date. Finally, surgical side‐effects and patient satisfaction with the surgical outcome were evaluated 3 years after LARS.
Postoperatively lower esophageal sphincter pressure improved significantly in all patients, whereas pH values showed normal data in all but 5 patients. Before surgery, all patients had a poor quality of life (GIQLI score, 90.1 ± 8.9 points). Postoperatively, GIQLI improved significantly (p <.01) and remained stable for at least 3 years, with a mean value of 123.7 ± 9.8 points.
This is comparable to 122.6 ± 8.5 points of healthy individuals.
Ninety‐eight percent of the patients rated their satisfaction with surgical treatment as excellent or good and would undergo surgery again if necessary. Nine patients suffered from minimal surgical side‐effects, but these did not significantly impair their quality of life. Laparoscopic reoperation was performed in 2 patients 3 months after initial surgery because of severe dysphagia. Both patients were free of symptoms 3 years after surgery. The efficacy and long‐term outcome of treatment of gastroesophageal reflux disease with laparoscopic "floppy" Nissen fundoplication can be evaluated by objective testing, but also with subjective judgment of the patient,
including quality of life assessment.
Intravenous Calcium Injection Test Is a Novel Complementary Procedure in Differential Diagnosis for Gastrinoma
Authors: Wada Michihiko , Komoto Izumi , Doi Ryuichiro , Imamura Masayuki
Published: October 2002

The current study evaluated efficacy of the intravenous calcium injection test as a new diagnostic approach to clarify the existence of gastrinoma, which often goes undetected with routine testing. Twenty‐six patients with hypergastrinemia were studied. For the calcium injection test, blood samples were taken from
12 patients with hypergastrinemia (HG), and three healthy volunteers,
and one patient with nonfunctioning endocrine tumor in the pancreas
(control). We compared results of the calcium injection test with those of the secretin test and the selective arterial secretagogue injection
(SASI) test. The SASI test with secretin was performed in 24 of 26
patients with hypergastrinemia, including 22 of 24 patients with Zollinger‐Ellison syndrome (ZES). Accuracy in the diagnosis of tumor localization by the SASI test was 95% (21 of 22) in ZES patients. The secretin test was negative in 3 of 21 patients with ZES (14%). Either the secretin test or the SASI test was positive in 22 of 23 patients
(96%). The calcium injection test was administered to 12 patients in the HG group and 4 controls. The HG group showed significantly higher serum gastrin levels than those of the control group in the calcium injection test. Eight of 10 ZES patients (80%) had a positive calcium injection test. We could diagnose gastrinomas in 100% of ZES patients by either the calcium injection test or the secretin test. We have thus confirmed the efficacy of the intravenous calcium injection test in the diagnosis of gastrinoma. The calcium injection test could become an adjunct in the diagnosis of gastrinoma, which often goes undetected with routine testing.
Can Dynamic Gadolinium‐enhanced Magnetic Resonance Imaging with Chemical Shift Studies Predict the Status of Adrenal Masses?
Authors: Prager Gerhard , Heinz‐Peer Gertraud , Passler Christian , Kaczirek Klaus , Schindl Martin , Scheuba Christian , Vierhapper Heinrich , Niederle Bruno
Published: October 2002

Endoscopic adrenalectomy represents the new gold standard in the surgical treatment of benign adrenal lesions up to 6 cm. In some cases lesions larger than 10 cm have been removed laparoscopically to offer the patient the advantages of the minimally invasive technique. The larger the diameter of an adrenal lesion, the greater the probability of malignancy. In a prospective study 130
consecutive patients (88 women, 42 men; mean age 47.8 years) with 137
adrenal lesions earmarked for surgery underwent preoperative gadolinium‐enhanced magnetic resonance imaging (MRI) with chemical shift studies (CSS). The aim of this study was to predict the status (benign, borderline, malignant) of adrenal lesions by MRI irrespective of tumor size. There were 14
patients with malignant tumors, 3 had borderline tumors (epithelial tumors with high malignant potential), and the remaining 120 had benign adrenal lesions. Five malignant lesions (36%) had a diameter < 6
cm. MRI correctly predicted 11 of 14 malignant tumors (1 malignant pheochromocytoma and 2 adrenocortical carcinomas had false‐negative results), 117 of 120 benign lesions, and 2 of 3 borderline lesions. All but two malignant tumors were operated on using open surgery; 82 (68%)
of 120 benign adrenal lesions were treated using the transperitoneal laparoscopic approach. Tumor size alone is not suitable for predicting the status of adrenal lesions. Dynamic gadolinium‐enhanced MRI with CSS can predict the status of at least 95% of adrenal lesions. Tumors
> 6 cm classified as benign by preoperative MRI may be removed laparoscopically by endocrine surgeons experienced in endoscopic adrenalectomy.
Minimally Invasive Video‐assisted Thyroidectomy: Multiinstitutional Experience
Authors: Miccoli Paolo , Bellantone Rocco , Mourad Michel , Walz Martin , Raffaelli Marco , Berti Piero
Published: October 2002

Minimally invasive video‐assisted thyroidectomy (MIVAT) was described in 1998. In this study we collected the experience of four third‐level referral centers that adopted this technique. A total of 336 patients (279 females, 57 males) were selected for MIVAT. Selection criteria were thyroid volume <15
ml, nodules not exceeding 3.5 cm of diameter, and an absence of thyroiditis, previous neck surgery, or previous irradiation. The procedure, totally gasless, is carried out through a 15 mm central incision above the sternal notch. Dissection is performed under endoscopic vision using conventional and endoscopic instruments. The mean operating time was 69.4 ± 30.6 minutes for lobectomy (range
20–150 minutes) and 87.4 ± 43.5 minutes for total thyroidectomy
(range 30–220 minutes). The mean postoperative stay was 1.9 ±
0.8 days. Postoperative complications were 7 transient and 1 definitive recurrent nerve palsies and 11 cases of hypoparathyroidism (9
transient, 2 definitive). Conversion to open surgery was necessary in
15 patients (4.5%). This study confirms in a large number of cases the safety and feasibility of MIVAT, even in different surgical settings where similar results were achieved. The complication rate was not different from that of standard thyroidectomy. Although the operating time appears longer than with conventional procedures, the learning curve demonstrates a sharp decrease with increasing experience and the introduction of new technologies. The number of patients eligible for this approach remains low, thereby limiting its use, but it should be considered a valid option in selected surgical centers, offering some advantages to patients in terms of cosmetic results and postoperative distress.
Laparoscopic Radiofrequency Ablation of Neuroendocrine Liver Metastases
Authors: Berber Eren , Flesher Nora , Siperstein Allan E.
Published: October 2002

We previously reported on the safety and efficacy of laparoscopic radiofrequency thermal ablation (RFA) for treating hepatic neuroendocrine metastases. The aim of this study is to report our 5‐year RFA experience in the treatment of these challenging group of patients. Of the 222 patients with 803 liver primary and secondary tumors undergoing laparoscopic RFA between January 1996 and August 2001, a total of 34 patients with 234 tumors had neuroendocrine liver metastases. There were 25 men and 9 women with a mean ± SEM age of 52 ± 2 years who underwent 42
ablations. Primary tumor types included carcinoid tumor in 18 patients,
medullary thyroid cancer in 7, secreting islet cell tumor in 5, and nonsecreting islet cell tumor in 4. There was no mortality, and the morbidity was 5%. The mean hospital stay was 1.1 days. Symptoms were ameliorated in 95%, with significant or complete symptom control in
80% of the patients for a mean of 10+ months (range 6–24 months). All patients were followed for a mean ± SEM of 1.6 ± 0.2 years
(range 1.0–5.4 years). During this period new liver lesions developed in 28% of patients, new extrahepatic disease in 25%, and local liver recurrence in 13%; existing liver lesions progressed in 13%.
Overall 41% of patients showed no progression of their cancer. Nine patients (27%) died. Mean ± SEM survivals after diagnosis of primary disease, detection of liver metastases, and performance of RFA were 5.5 ± 0.8 years, 3.0 ± 0.3 years, and 1.6 ± 0.2
years, respectively. Sixty‐five percent of the patients demonstrated a partial or significant decrease in their tumor markers during follow‐up. In conclusion, RFA provides excellent local tumor control with overnight hospitalization and low morbidity in the treatment of liver metastases from neuroendocrine tumors. It is a useful modality in the management of these challenging group of patients.
Prospective Trial of Unilateral Surgery for Nonhereditary Medullary Thyroid Carcinoma in Patients without Germline RET Mutations
Authors: Miyauchi Akira , Matsuzuka Fumio , Hirai Keisuke , Yokozawa Tamotsu , Kobayashi Kaoru , Ito Yasuhiro , Nakano Keiichi , Kuma Kanji , Futami Hitoyasu , Yamaguchi Ken
Published: October 2002

Although sporadic medullary thyroid carcinoma (MTC) tends to be unicentric and confined to one lobe, total thyroidectomy is usually performed because of the risk of a hereditary or bilateral process. Germline RET mutation analysis can discriminate hereditary MTC and truly sporadic, nonhereditary MTC. We analyzed 72 of 94 patients with MTC to establish the genetic nature and the clinical features of nonhereditary MTC. Since 1996 we have prospectively treated 15 patients with nonhereditary MTC (prospective study group, or PSG) according to a unilateral surgery policy. A group of 22 previously operated patients in whom the nonhereditary nature was established served as controls (retrospective study group, or RSG).
Systematic central and ipsilateral neck dissection was performed in both groups. Outcome was assessed using postoperative stimulated serum calcitonin levels; a normal value was considered a biochemical cure.
All 24 hereditary MTC patients carried germline RET mutations: 8 of 48 patients with apparently sporadic MTC had the mutations, and 6 of the 8 had bilateral MTC. All 40 patients without mutations had a unilateral tumor. In the RSG group 15 of 22 (68%)
patients underwent total thyroidectomy, and the biochemical cure rate was 68%. Although only 3 of 15 (20%) of the PSG patients underwent total thyroidectomy, 12 of the 15 (80%) achieved biochemical cure.
Univariate analyses revealed that pathologic node involvement— high T and N stages—was adversely related to biochemical cure. The extent of thyroid resection was not related to biochemical cure. Of 20
patients with node involvement, 10 achieved biochemical cure,
indicating the importance of systematic neck dissection.
Hemithyroidectomy with systematic central and ipsilateral neck dissection is appropriate surgery for nonhereditary MTC.
Relation between Ultrasonographic and Histologic Findings of Tracheal Invasion by Differentiated Thyroid Cancer
Authors: Yamamura N. , Fukushima S. , Nakao K. , Nakahara M. , Kurozumi K. , Imabun S. , Tsujimoto M.
Published: October 2002

Between 1988 and 1999 a total of 24
patients with differentiated thyroid cancer invading the airway underwent various types of tracheal resection at the Osaka Police Hospital. Preoperative ultrasonographic (US) findings in these patients were compared with postoperative histologic results of the resected specimens to confirm the relation between the preoperative and postoperative diagnoses and to determine the indications for operative procedures. Preoperative US revealed cancer invasion to the adventitia in 2 cases, to the intercartilage space in 13, and to the tracheal mucosa in 9. Histologically, cancer invasion to the adventitia was confirmed in 4, to the intercartilage space in 10, and to the mucosa in
10. Among 13 cancer invasion instances to the intercartilage revealed by US, overdiagnosis occurred in 3 cases and underdiagnosis in 1. The actual overall diagnostic rate by US was 83.3%, which is a great improvement over other available methods. In conclusion, preoperative US findings of the trachea agreed with the histologic findings of the resected specimens, indicating US to be the first choice when making decisions about resecting the trachea and about the operative procedure.
Diversification of Minimally Invasive Parathyroidectomy for Primary Hyperparathyroidism: Minimally Invasive Video‐assisted Parathyroidectomy and Minimally Invasive Open Videoscopically Magnified Parathyroidectomy with Local Anesthesia
Authors: Lorenz Kerstin , Phuong Nguyen‐Thanh , Dralle Henning
Published: October 2002

With the expansion of minimally invasive parathyroid surgery for primary hyperparathyroidism, new approaches and techniques evolved, creating new surgical algorithms with consequences for indication for surgery and patient selection. The presented methods of selective, minimally invasive parathyroidectomy represent this development of diversification. Minimally invasive video‐assisted parathyroidectomy (MIVAP)
has advanced to bilateral exploration, avoiding preoperative localization other than ultrasonography. Furthermore, a new technique of minimally invasive open parathyroidectomy with the option of videoscopic magnification under local anesthesia (MIPLA) for localizable adenomas is introduced. A series of 103
patients were operated on for primary hyperparathyroidism using minimally invasive procedures: 87 with MIVAP and 16 with MIPLA. With MIVAP the conversion rate to cervicotomy for multiglandular disease or technical difficulties was
16% (n = 14). With MIPLA, conversion to general intubation anesthesia or additional sedation was necessary in four patients. A transient laryngeal nerve palsy was observed in one patient with MIVAP.
Bilateral exploration was carried out during 29 MIVAPs and 2 MIPLAs. The duration of surgery differed, with a median 63 minutes for MIVAP and 39 minutes for MIPLA. Surgery under local anesthesia was completed in 4 patients with MIVAP and in 14 with MIPLA. All patients were cured of primary hyperparathyroidism. Preliminary results of diversified procedures demonstrate effects regarding omission of preoperative diagnostics, overall cost reduction,
and increasing patient selection for selective parathyroid surgery because of primary hyperparathyroidism.
Outcome of Laparoscopic Pancreatic Surgery: Endocrine and Nonendocrine Tumors
Authors: Fernández‐Cruz L. , Sáenz A. , Astudillo E. , Martinez I. , Hoyos S. , Pantoja J.P. , Navarro S.
Published: October 2002

Laparoscopic pancreatic surgery (LapPS)
for management of benign pancreatic tumors has still not been defined.
This paper evaluates the feasibility and outcome of LapPS in patients with endocrine pancreatic tumors (EPTs) and cystic neoplasms of the pancreas (CyNP). Eighteen patients with benign pancreatic tumors underwent LapPS between January 1998 and May 2001. The indications were
10 EPTs (6 sporadic insulinomas, 1 multiple insulinoma of multiple endocrine neoplasia type 1, 2 nonfunctioning tumors, 1 VIPoma) and 8
CyNPs (3 serous cystadenomas, 5 mucinous cystic neoplasms). The laparoscopic procedure was performed using four ports with patients in the half‐lateral position. Laparoscopic ultrasonography (LapUS) was used in all cases. Laparoscopic enucleation (LapE) was planned in five patients and performed in four (one conversion for tumor not found during laparoscopy). Laparoscopic pancreatic resection (LapPR) with spleen salvage was planned in 13 patients and performed in 12 (one conversion for metastatic VIPoma), with splenic vessel preservation in
11 patients and short gastric vessel preservation in 1. The average operating time was 3.5 hours after enucleation, 4.0 hours after distal pancreatectomy, and 5.0 hours after subtotal pancreatectomy. Pancreatic fistula was observed in two patients after LapE and in three patients after LapPR. Splenectomy for splenic abscess was performed 1 week after surgery in a patient with short gastric vessel splenic preservation.
The average hospital stay was 5 days. We concluded that LapPS is a safe method for removing EPTs and CyNPs, although the incidence of pancreatic fistulas remains high. In selected patients LapPS offers significant benefit to patients: reduced trauma to the abdominal wall,
short hospital stay, and a quick postoperative recovery.
Epithelioid Gastrointestinal Stromal Tumor of the Stomach with Liver Metastases in a 12-Year-old Girl: Aspiration Cytology and Molecular Study
Authors: Li Peng , Wei Jianjun , West A. Brian , Perle MaryAnn , Greco M. Alba , Yang Grace C.H.
Published: October 2002

Gastrointestinal stromal tumor (GIST), a stromal tumor of the gastrointestinal tract defined as CD117 (c- kit)-positive neoplasm, occurs primarily in adults. GIST with CD117 (c- kit) mutation and certain cytogenetic abnormalities is associated with malignancy, though a definite relationship between prognosisand molecular alterations remains to be elucidated. We report the cytologic features of an epithelioid GIST arising in the stomach of a child and metastatic to the liver, and the molecular mutational analysis of both the primary gastric tumor and the liver metastasis. Literature of pediatric GISTs was also reviewed. Fine needle aspiration of the liver metastasis, processed by Ultrafast Papanicolaou stain, showed fragments of cohesive small epithelioid cells with bland oval nuclei and unipolar cytoplasm transected by capillaries. Immunohistochemically, all nodules in the stomach and liver expressed CD117 (c- kit). Interestingly, some of the gastric tumor clusters were uniformly CD34 positive, whereas others were uniformly CD34 negative, suggesting heterogeneity of tumor clones. The presence of neurosecretory granules further subtyped the tumor into gastric autonomic nerve tumor (GANT). Molecular mutational analysis, performed in both the gastric tumor and the liver metastasis, showed no sequence abnormality in exons 9, 11, and 13 of CD117 (c- kit). Cytogenetic study revealed normal karyotype. These features might suggest a different molecular mechanism leading to malignancy in certain GISTs arising in children.
Regulation of a mammalian Shaker‐related potassium channel, hKv1.5, by extracellular potassium and pH
Authors: Jäger Heike , Grissmer Stephan
Published: October 2002

Using the whole‐cell recording mode of the patch‐clamp technique we studied the effects of removal of extracellular potassium, [K+]o, on a mammalian Shaker‐related K+ channel, hKv1.5. In the absence of [K+]o, current through hKv1.5 was similar to currents obtained in the presence of 4.5 mM [K+]o. This observation was not expected as earlier results had suggested that either positively charged residues or the presence of a nitrogen‐containing residue at the external TEA+ binding site (R487 in hKv1.5) caused current loss upon removal of [K+]o. However, the current loss in hKv1.5 was observed when the extracellular pH, pHo, was reduced from 7.4 to 6.0, a behavior similar to that observed previously for current through mKv1.3 with a histidine at the equivalent position (H404). These observations suggested that the charge at R487 in hKv1.5 channels was influenced by other amino acids in the vicinity. Replacement of a histidine at position 463 in hKv1.5 by glycine confirmed this hypothesis making this H463G mutant channel sensitive to removal of [K+]o even at pHo 7.4. We conclude that the protonation of H463 at pH 7.4 might induce a pK
a shift of R487 that influences the effective charge at this position leading to a not fully protonated arginine. Furthermore, we assume that the charge at position 487 in hKv1.5 can directly or indirectly disturb the occupation of a K+ binding site within the channel pore possibly by electrostatic interaction. This in turn might interfere with the concerted transition of K+ ions resulting in a loss of K+ conduction.
The essential amino acid lysine acts as precursor of glutamate in the mammalian central nervous system
Authors: Papes Fabio , Surpili Marcelo J. , Langone Francesco , Trigo Jose R. , Arruda Paulo
Published: October 2002

Lysine has long been recognized as an essential amino acid for humans and the lack or low supply of this compound in the diet may lead to mental and physical handicaps. Since lysine is severely restricted in cereals, the most important staple food in the world, the understanding of its biological roles must be a major concern. Here we show that lysine is an important precursor for de novo synthesis of glutamate, the most significant excitatory neurotransmitter in the mammalian central nervous system. We also show that the synthesis of glutamate from lysine, which is carried out by the saccharopine pathway, is likely to take place in neurons.
Tuning of the product spectrum of vanillyl‐alcohol oxidase by medium engineering
Authors: van den Heuvel Robert H.H , Partridge Johann , Laane Colja , Halling Peter J , van Berkel Willem J.H
Published: October 2002

The flavoenzyme vanillyl‐alcohol oxidase (VAO) catalyzes the conversion of 4‐alkylphenols through the initial formation of p‐quinone methide intermediates. These electrophilic species are stereospecifically attacked by water to yield (R)‐1‐(4′‐hydroxyphenyl)alcohols or rearranged in a competing reaction to 1‐(4′‐hydroxyphenyl)alkenes. Here, we show that the product spectrum of VAO can be controlled by medium engineering. When the enzymatic conversion of 4‐propylphenol was performed in organic solvent, the concentration of the alcohol decreased and the concentration of the cis‐alkene, but not the trans‐alkene, increased. This change in selectivity occurred in both toluene and acetonitrile and was dependent on the water activity of the reaction medium. A similar shift in alcohol/cis‐alkene product ratio was observed when the VAO‐mediated conversion of 4‐propylphenol was performed in the presence of monovalent anions that bind specifically near the enzyme active site.
Efficient biochemical engineering of cellular sialic acids using an unphysiological sialic acid precursor in cells lacking UDP‐N‐acetylglucosamine 2‐epimerase
Authors: Mantey Lars R , Keppler Oliver T , Pawlita Michael , Reutter Werner , Hinderlich Stephan
Published: October 2002

Sialic acids comprise a family of terminal sugars essential for a variety of biological recognition systems. N‐Propanoylmannosamine, an unphysiological sialic acid precursor, is taken up and metabolized by mammalian cells resulting in oligosaccharide‐bound N‐propanoylneuraminic acid. N‐Propanoylmannosamine, applied to endogenously hyposialylated subclones of the myeloid leukemia HL60 and of the B‐cell lymphoma BJA‐B, both deficient in UDP‐N‐acetylglucosamine 2‐epimerase, is efficiently metabolized to CMP‐N‐propanoylneuraminic acid resulting in up to 85% of glycoconjugate‐associated sialic acids being unphysiological N‐propanoylneuraminic acid. Thus, UDP‐N‐acetylglucosamine 2‐epimerase‐deficient cell lines provide an important experimental progress in engineering cells to display an almost homogeneous population of defined, structurally altered sialic acids.
The anti‐apoptotic protein BAG‐3 is overexpressed in pancreatic cancer and induced by heat stress in pancreatic cancer cell lines
Authors: Liao Quan , Ozawa Fumiaki , Friess Helmut , Zimmermann Arthur , Takayama Shinichi , Reed John C. , Kleeff Jörg , Büchler Markus W.
Published: October 2002

Pancreatic cancer cells are usually resistant to apoptosis mediated by intrinsic or extrinsic factors. BAG‐3 (Bis, CAIR), which was identified as a BAG‐1‐related protein, is a novel modulator of cellular anti‐apoptotic activity that functions through its interaction with Bcl‐2. In this study we analyzed BAG‐3 expression in human pancreatic cancer tissues and cell lines. BAG‐3 mRNA was expressed at moderate to high levels in all pancreatic cancer samples, but at low levels in normal pancreas tissues. In situ hybridization and immunohistochemistry analysis revealed that BAG‐3 was present in the cancer cells within the pancreatic tumor mass. When BAG‐3 mRNA was analyzed in other gastrointestinal cancers (hepatocellular carcinoma; esophageal, stomach and colon cancer), no difference was found from their corresponding normal controls. In pancreatic cancer cells, BAG‐3 mRNA expression levels were strongly induced after heat stress, but not in response to members of the tumor necrosis factor (TNF)‐α family (TNF‐α, TRAIL, FasL). These findings indicate that in pancreatic cancer, in contrast to other gastrointestinal malignancies, increased levels of BAG‐3 might function to block apoptosis. This characteristic of pancreatic cancer might contribute to its more aggressive growth behavior and poor responsiveness to treatment in vivo.
Crystal structure of neuroserpin: a neuronal serpin involved in a conformational disease
Authors: Briand Christophe , Kozlov Serguei V. , Sonderegger Peter , Grütter Markus G.
Published: October 2002

The protease inhibitor neuroserpin regulates the development of the nervous system and its plasticity in the adult. Neuroserpins carrying the Ser53Pro or Ser56Arg mutation form polymers in neuronal cells. We describe here the structure of wild‐type neuroserpin in a cleaved form. The structure provides a basis to understand the role of the mutations in the polymerization process. We propose that these mutations could delay the insertion of the reactive center loop into the central β‐sheet A, an essential step in the inhibition and possibly in the polymerization of neuroserpin.
Proteasome inhibitors induce Fas‐mediated apoptosis by c‐Myc accumulation and subsequent induction of FasL message in human glioma cells
Authors: Tani Eiichi , Kitagawa Hiroyuki , Ikemoto Hideyasu , Matsumoto Tsuyoshi
Published: October 2002

Proteasome inhibitors were shown previously to induce mitochondria‐independent and caspase‐3‐dependent apoptosis in human glioma cell lines by unknown mechanisms. Here, we showed that treatment with proteasome inhibitors, lactacystin or acetyl‐leucinyl‐leucinyl‐norleucinal, led to elevation of the steady‐state c‐Myc protein but not c‐myc mRNA, suggesting the accumulation of c‐Myc protein by proteasome inhibitors. In addition, the marked association of c‐Myc protein with ubiquitin by treatment with proteasome inhibitors indicated the involvement of proteasome in c‐Myc proteolysis and the stabilization of c‐Myc protein by proteasome inhibitors in vivo. The expression of Fas (also termed CD95 or APO‐1) mRNA, if analyzed by reverse transcriptase polymerase chain reaction assay, was found to occur constitutively, and increased slightly by the treatment with proteasome inhibitors. In contrast, the expression of Fas ligand (FasL) mRNA was markedly induced temporarily before the activation of caspase‐3 by the treatment. Agonistic anti‐Fas antibody (CH11) induced apoptotic cell death, suggesting the presence of a functional Fas receptor. In addition, proteasome inhibitor‐induced apoptosis was prevented by the addition of antagonistic anti‐FasL antibody (4A5) or z‐IETD.fmk, a potent inhibitor of caspase‐8, indicating the involvement of the Fas receptor–ligand apoptotic signaling system in proteasome inhibitor‐mediated apoptosis. Thus, it is suggested that proteasome inhibitors cause the accumulation of c‐Myc protein which induces transiently FasL message to stimulate the Fas receptor–ligand apoptotic signaling pathway.
Insulin antagonizes AMP‐activated protein kinase activation by ischemia or anoxia in rat hearts, without affecting total adenine nucleotides
Authors: Beauloye Christophe , Marsin Anne-Sophie , Bertrand Luc , Krause Ulrike , Hardie D.Grahame , Vanoverschelde Jean-Louis , Hue Louis
Published: October 2002

AMP‐activated protein kinase (AMPK) is known to be activated by phosphorylation on Thr172 in response to an increased AMP/ATP ratio. We report here that such an activation indeed occurred in anaerobic rat hearts and that it was antagonized (40–50%) when the hearts were pre‐treated with 100 nM insulin. The effect of insulin (1) was blocked by wortmannin, an inhibitor of phosphatidylinositol‐3‐kinase; (2) only occurred when insulin was added before anoxia, suggesting a hierarchical control; (3) resulted in a decreased phosphorylation state of Thr172 in AMPK and (4) was unrelated to changes in the AMP/ATP ratio. This is the first demonstration that AMPK activity could be changed without a detectable change in the AMP/ATP ratio of the cardiac cell.
Differential display analysis of mutants for the transcription factor Pdr1p regulating multidrug resistance in the budding yeast
Authors: Miura Fumihito , Yada Tetsushi , Nakai Kenta , Sakaki Yoshiyuki , Ito Takashi
Published: October 2002

The transcription factor Pdr1p recognizes Pdr1p/Pdr3p‐response element (PDRE) to activate genes involved in multidrug resistance of the budding yeast. To identify novel targets of Pdr1p, we compared transcriptomes among the yeast cells bearing wild, disrupted and gain‐of‐function alleles of PDR1 using a high‐throughput fluorescent differential display PCR. Consequently, we identified 20 transcripts apparently regulated by Pdr1p, which are derived from well‐known target genes as well as those that have never been described in the context of drug resistance. Intriguingly, among the latter, a previously unrecognized gene bearing a small putative open reading frame preceded by a functional PDRE was found.
Methylobacillus flagellatus KT contains a novel cbo‐type cytochrome oxidase
Authors: Strom Evguenia V , Dinarieva Tatiana Y , Netrusov Alexander I
Published: October 2002

The o‐type oxidase from the methanol‐grown obligate methylotroph Methylobacillus flagellatus KT has been purified to homogeneity. The complex is composed of four subunits (57, 40, 35 and 30 kDa). It contains six haems (4C:1B:1O) and one copper atom per molecule. It is proposed that the haem O‐CuB binuclear centre and a low‐spin haem B are located in subunit I (57 kDa), two haems C reside in the cytochrome c homodimer (35 kDa), two haems C belong to the dihaem cytochrome c (30 kDa). The presented data provide evidence that cytochrome cbo is a novel representative of the haem–copper oxidase superfamily.
A DNA polymerase ϵ inhibitor activates the ribo and deoxyribo modes of primase expression and induces a unique phenomenon of primer accumulation1
Authors: Řı́man Josef
Published: October 2002

Carbonyldiphosphonate (COMDP), a selective inhibitor of DNA polymerase (pol) ϵ, strongly stimulates expression of the ribo and deoxyribo modes of primase (Pr) activities of the Pr–DNA pol α enzyme complex associated with special cytoplasmic nucleoprotein complexes of chicken leukemic myeloblasts [J. Řı́man and A. Šulová, Acta Virol. 41 (1997) 181–214]. Besides stimulation, COMDP uncouples the Pr activities from those of DNA pol α, inducing in this way a unique phenomenon of accumulation of primers of basic length. In the presence of dNTPs, the COMDP effect is counteracted by excess of mimosine. The mutually exclusive effects of these agents are discussed.
Penetratin‐induced aggregation and subsequent dissociation of negatively charged phospholipid vesicles
Authors: Persson Daniel , Thorén Per E.G , Nordén Bengt
Published: October 2002

The interaction of the cellular delivery vector penetratin with a model system consisting of negatively charged phospholipid vesicles has been studied. Above a certain peptide to lipid molar ratio, the cationic oligopeptide induces vesicle aggregation. Interestingly, the aggregation is followed by spontaneous disaggregation, which may be related to membrane translocation of the peptide. Circular dichroism (CD) measurements indicate a conformational transition, from α‐helix to antiparallel β‐pleated sheet, which is simultaneous with the aggregation process. The potential influence of spectroscopic artifacts on CD data due to the drastically increased turbidity during aggregation is discussed.
Multimerization potential of the cytoplasmic domain of the human cytomegalovirus glycoprotein B
Authors: Scheffczik Hanno , Kraus Ina , Kiermayer Simone , Bogner Elke , Holzenburg Andreas , Garten Wolfgang , Eickmann Markus
Published: October 2002

In the present study the coding sequence of the cytoplasmic tail of the human cytomegalovirus glycoprotein B (gB) was expressed. The secondary structure of the purified recombinant protein was analyzed by circular dichroism, and the quaternary structure was investigated by gel permeation chromatography, and electron microscopy. Our data indicate that the cytoplasmic gB domain contains α‐helix structures and assembles into tetramers, suggesting that the authentic gB may represent a homotetramer.
Diminished corneal angiogenesis in gelatinase A‐deficient mice
Authors: Kato Takuji , Kure Tomoko , Chang Jin-Hong , Gabison Eric E. , Itoh Takeshi , Itohara Shigeyoshi , Azar Dimitri T.
Published: October 2002

The goal of the present study was to define the role of gelatinase A in angiogenesis. We performed corneal micropocket assays in gelatinase A‐deficient mice and their age‐matched wild‐type littermates. The corneal neovascular area in gelatinase A‐deficient mice (0.15±0.14 mm2) was significantly less than that of wild‐type littermates (0.53±0.35 mm2; P<0.01). Similarly, aortic ring assays showed significant reduction of endothelial outgrowth in gelatinase A‐deficient mice (0.26±0.14 mm2) as compared to wild‐type littermates (0.44±0.06 mm2; P<0.05). These results suggest that gelatinase A may play an important role in the regulation of corneal angiogenesis.