bluuebunny/crossref_metadata_2025 huggingface dataset:
Hodgkin's lymphoma cell lines are characterized by frequent aberrations on chromosomes 2p and 9p including REL and JAK2
Authors: Joos Stefan , Granzow Martin , Holtgreve‐Grez Heidi , Siebert Reiner , Harder Lana , Martín‐Subero José I. , Wolf Jürgen , Adamowicz Martyna , Barth Thomas F.E. , Lichter Peter , Jauch Anna
Published: December 2002

Four Hodgkin's lymphoma cell lines (KM‐H2, HDLM‐2, L428, L1236) were analyzed for cytogenetic aberrations, applying multiplex fluorescence in situ hybridization, chromosome banding and comparative genomic hybridization. Each line was characterized by a highly heterogeneous pattern of karyotypic changes with a large spectrum of different translocated chromosomes (range 22–57). A recurrent finding in all cell lines was the presence of chromosomal rearrangements of the short arm of chromosome 2 involving the REL oncogene locus. Furthermore, multiple translocated copies of telomeric chromosomal segments were frequently detected. This resulted in a copy number increase of putative oncogenes, e.g., JAK2 (9p24) in 3 cell lines, FGFR3 (4p16) and CCND2 (12p13) in 2 cell lines as well as MYC (8q24) in 1 cell line. Our data confirm previous cytogenetic results from primary Hodgkin's tumors suggesting an important pathogenic role of REL and JAK2 in this disease. In addition, they provide evidence for a novel cytogenetic pathomechanism leading to increased copy numbers of putative oncogenes from terminal chromosomal regions, most probably in the course of chromosomal stabilization by telomeric capture. © 2002 Wiley‐Liss, Inc.
Multigene analysis of Rb pathway and apoptosis control in esophageal squamous cell carcinoma identifies patients with good prognosis
Authors: Güner Dilek , Sturm Isrid , Hemmati Philipp , Hermann Sandra , Hauptmann Steffen , Wurm Reinhard , Budach Volker , Dörken Bernd , Lorenz Matthias , Daniel Peter T.
Published: December 2002

Deregulation of cell‐cycle G1‐restriction point control by disruption of Rb‐pathway components is a frequent event in cancer. In concert with the inactivation of cell death pathways, such events not only contribute to tumor development but also determine the intrinsic and acquired resistance to cancer therapy and, ultimately, disease prognosis. We previously observed that the cyclin‐dependent kinase inhibitor p16INK4a and the proapoptotic Bcl‐2 homolog Bax are positive prognostic factors and identify patients with good prognosis in esophageal squamous cell carcinoma (SCC). In the present study, we therefore extend our analysis to additional genes controlling the G1 restriction point and apoptosis, respectively. This retrospective analysis was performed in a cohort of 53 patients undergoing surgery for esophageal SCC with curative intent, i.e., R0 resection. Protein expression profiles of cyclin D1, p16INK4a, Rb, p21CIP/WAF‐1, p53, Bax and Bcl‐2 were analyzed by immunohistochemistry and compared to p53 mutational status, as determined by SSCP‐PCR of exons 5–8. Loss of p16INK4a, Rb, p21CIP/WAF‐1 or Bax and overexpression of cyclin D1 were associated individually with shorter overall survival, while Bcl‐2 expression and p53 mutation were not of prognostic relevance. The longest survival was observed in a subgroup of patients whose tumors bore a combination of favorite genotypes, i.e., low cyclin D1 and high Rb, p21CIP/WAF‐1, p16INK4a and Bax protein expression. These results show that multigene analyses based on limited sets of functionally linked genes reliably identify patients with good vs. poor prognosis. © 2003 Wiley‐Liss, Inc.
Inactivation of the DNA repair gene O6‐methylguanine‐DNA methyltransferase by promoter hypermethylation and its relationship to aflatoxin B1‐DNA adducts and p53 mutation in hepatocellular carcinoma
Authors: Zhang Yu‐Jing , Chen Yu , Ahsan Habibul , Lunn Ruth M. , Lee Po‐Huang , Chen Chien‐Jen , Santella Regina M.
Published: December 2002

O6‐methylguanine‐DNA methyltransferase (MGMT) is a repair protein that specifically removes promutagenic alkyl groups from the O6 position of guanine in DNA. MGMT is transcriptionally silenced by promoter hypermethylation in several human cancers. Methylation‐specific PCR (MSP) was used to analyze the MGMT promoter methylation status of 83 hepatocellular carcinomas (HCC) and 2 HCC cell lines (HepG2 and Hep3B). Hypermethylation was detected in 32 of 83 (39%) HCC tissues, but it was not found in either HCC cell line. We also analyzed MGMT expression by immunohistochemical analysis of HCC tissue samples. The presence of aberrant hypermethylation was associated with loss of MGMT protein. The relationship between methylation status and risk factors and tumor markers including environmental exposure to aflatoxin B1 (AFB1), measured as DNA adducts, and status of tumor suppressor gene p53 was also investigated. A statistically significant association was found between MGMT promoter hypermethylation and high level of AFB1‐DNA adducts in tumor tissues (OR = 5.05, 95% CI = 1.29–19.73). A significant association was also found between methylation and p53 mutation status (OR = 2.97, 95% CI = 1.09–8.11). These results suggest that epigenetic inactivation of MGMT plays an important role in the development of HCC and exposure to environmental carcinogens may be related to altered methylation of genes involved in cancer development. The role of chemical carcinogens in hypermethylation needs further investigation. © 2002 Wiley‐Liss, Inc.
Risk of melanoma among radiologic technologists in the United States
Authors: Freedman D. Michal , Sigurdson Alice , Rao R. Sowmya , Hauptmann Michael , Alexander Bruce , Mohan Aparna , Doody Michele Morin , Linet Martha S.
Published: December 2002

Our study examines the risk of melanoma among medical radiation workers in the U.S. Radiologic Technologists (USRT) study. We evaluated 68,588 white radiologic technologists (78.8% female), certified during 1926–1982, who responded to a baseline questionnaire (1983–1989) and were free of cancer other than nonmelanoma skin at that time. Participants were followed through completion of a second questionnaire (1994–1998). We identified 207 cases, 193 subjects who reported first primary melanoma and 14 decedents with melanoma listed as an underlying or contributory cause of death. We examined risks of occupational radiation exposures using work history information on practices, procedures, and protective measures reported on the baseline questionnaire. Based on Cox proportional hazards regression, melanoma was significantly associated with established risk factors, including constitutional characteristics (skin tone, eye and hair color), personal history of nonmelanoma skin cancer, family history of melanoma and indicators of residential sunlight exposure. Melanoma risk was increased among those who first worked before 1950 (RR = 1.8, 95% CI = 0.6–5.5), particularly among those who worked 5 or more years before 1950 (RR = 2.4; 0.7–8.7; p (trend) for years worked before 1950 = 0.03), when radiation exposures were likely highest. Risk was also modestly elevated among technologists who did not customarily use a lead apron or shield when they first began working (RR = 1.4; 0.8–2.5). Clarifying the possible role of exposure to chronic ionizing radiation in melanoma is likely to require nested case‐control studies within occupational cohorts, such as this one, which will assess individual radiation doses, and detailed information about sun exposure, sunburn history and skin susceptibility characteristics. Published 2002 Wiley‐Liss, Inc.
Glypican‐3, overexpressed in hepatocellular carcinoma, modulates FGF2 and BMP‐7 signaling
Authors: Midorikawa Yutaka , Ishikawa Shumpei , Iwanari Hiroko , Imamura Takeshi , Sakamoto Hirohiko , Miyazono Kohei , Kodama Tatsuhiko , Makuuchi Masatoshi , Aburatani Hiroyuki
Published: December 2002

The Glypican (GPC) family is a prototypical member of the cell‐surface heparan sulfate proteoglycans (HSPGs). The HSPGs have been demonstrated to interact with growth factors, act as coreceptors and modulate growth factor activity. Here we show that based on oligonucleotide array analysis, GPC3 was upregulated in hepatocellular carcinoma (HCC). By northern blot analysis, GPC3 mRNA was found to be upregulated in 29 of 52 cases of HCC (55.7%). By Western blot analysis carried out with a monoclonal anti‐GPC3 antibody we generated, the GPC3 protein was found to be overexpressed in 6 hepatoma cell lines, HepG2, Hep3B, HT17, HuH6, HuH7 and PLC/PRF/5, as well as 22 tumors (42.3%). To investigate the role of overexpressed GPC3 in liver cancer, we analyzed its effects on cell growth of hepatoblastoma‐derived cells. Overexpression of GPC3 modulated cell proliferation by inhibiting fibroblast growth factor 2 (FGF2) and bone morphogenetic protein 7 (BMP‐7) activity. An interaction of GPC3 and FGF2 was revealed by co‐immunoprecipitation, while GPC3 was found to inhibit BMP‐7 signaling through the Smad pathway by reporter gene assay. The modulation of growth factors by GPC3 may help explain its role in liver carcinogenesis. In addition, the ability of HCC cells to express GPC3 at high levels may serve as a new tumor marker for HCC. © 2002 Wiley‐Liss, Inc.
Neuroblastoma trends in Osaka, Japan, and Great Britain 1970–1994, in relation to screening
Authors: Honjo Satoshi , Doran Helen E. , Stiller Charles A. , Ajiki Wakiko , Tsukuma Hideaki , Oshima Akira , Coleman Michel P.
Published: December 2002

Japan pioneered and has maintained a nationwide mass screening programme for neuroblastoma since 1985 without prior evaluation among a target population. Convincing population‐based evaluation of the ongoing programme has also been very limited because a population‐based registry for childhood cancer has not been in operation. This report describes trends in incidence of and mortality from neuroblastoma in Osaka Prefecture, Japan, using Great Britain as an external control, between 1970 and 1994. Incidence and mortality rates were comparable between the 2 areas before the beginning of screening in Osaka. However, incidence rates were markedly increased in Osaka, especially among children younger than 1 year, from 25.9 per million children during 1970–1979 to 240.2 during 1991–1994, while age‐standardized incidence rates for metastatic tumours among children aged 1 year or above did not decrease after introduction of the programme. Age‐standardized mortality rates per million were unchanged at 3.9 (1970–1979) and 4.1 (1991–1994) in Osaka and 5.7 (1971–1979) and 5.0 (1991–1994) in Great Britain. Cumulative incidence rates among those up to 15 years old progressively increased from 103.4 per million (1970–1979) to 350.0 (1991–1994) in Osaka, though cumulative mortality rates did not decrease: 52.0 and 57.5, respectively. Corresponding figures in Great Britain were 101.0, 115.1, 78.6 and 70.1, respectively. The present findings show little beneficial effect of the screening programme. © 2002 Wiley‐Liss, Inc.
Echocardiographic diagnosis and follow‐up of left ventricular pseudoaneurysm complicating bacterial pericarditis
Authors: Deng You‐Bin , Chang Qing , Xiang Hui‐Juan , Li Chun‐Lei
Published: December 2002

Two‐dimensional echocardiography demonstrated a pseudoaneurysm of the lateral wall of the left ventricle in a 13‐year‐old girl with bacterial pericarditis. The echocardiographic findings included a 5‐mm discontinuity in the lateral wall of the left ventricle, an associated anechoic collection (5.6 × 5.1 cm), and a narrow communication between the left ventricle and the anechoic collection. Color Doppler imaging demonstrated flow through the communication between the left ventricle and the aneurysmal cavity. The patient and her family refused surgery. A follow‐up echocardiographic examination more than 6 years later demonstrated disappearance of the discontinuity of the left ventricular lateral wall, no flow between the left ventricle and the pseudoaneurysm, and thrombus formation within the pseudoaneurysm. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:48–50, 2003
Tuberculous ileitis in a renal transplant recipient with familial Mediterranean fever: Gray‐scale and power Doppler sonographic findings
Authors: Yilmaz Erkan , Balci Ali , Sal Selma , Cakmakci Handan
Published: December 2002

The ileocecal area is the most common site of involvement of intestinal tuberculosis. We report the case of a 26‐year‐old renal transplant recipient with familial Mediterranean fever who developed tuberculous ileitis. Gray‐scale sonography and CT showed circumferential thickening of the bowel wall and enlargement of the mesenteric lymph nodes. Power Doppler sonography revealed markedly increased vascularity in the wall of the affected ileal segment and in the mesenteric nodes. Some nodes had no flow at the center owing to caseation necrosis, a finding consistent with the diagnosis of tuberculous ileitis. Colonoscopy was performed, and histopathologic examination of biopsy specimens revealed acute inflammatory changes. Cultures of the specimens confirmed the presence of Mycobacterium tuberculosis. We conclude that findings on power Doppler sonography may support a diagnosis of tuberculous ileitis and avoid clinical mismanagement. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:51–54, 2003
Posterior mediastinal arteriovenous malformation with atypical color Doppler sonographic findings
Authors: Cheng Shih‐Lung , Wang Hao‐Chien , Yang Pan‐Chyr
Published: December 2002

An arteriovenous malformation (AVM) is an anomaly of capillary development that results in a direct connection between branches of an artery and veins, with no intervening capillary network. A definite diagnosis of AVM is usually made with angiography. We report the case of a posterior mediastinal AVM found on routine sonography in a 64‐year‐old woman with neglected hypertension and severe back pain. Color Doppler imaging showed 2 adjoined vascular structures without a typical mosaic‐like flow pattern, and spectral Doppler analysis showed low‐resistance flow and arteriovenous shunting in 2 adjoined vascular structures. The diagnosis was subsequently confirmed by angiography. Because disastrous bleeding could result if needle biopsy were performed inadvertently in the case of a suspected mediastinal AVM, we suggest that color Doppler sonography be attempted if there is an adequate acoustic window. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:44–47, 2003
Five‐year follow‐up of placental involution after abdominal pregnancy
Authors: Valenzano Mario , Nicoletti Luca , Odicino Franco , Cocuccio Silvia , Lorenzi Paola , Ragni Nicola
Published: December 2002

A 29‐year‐old woman with an abdominal pregnancy was admitted to the hospital at 29 weeks' menstrual age. At 30 weeks, laparotomy was performed, and a live fetus, wrapped in membrane remnants, was taken from the abdominal cavity. The placenta, inserted in the right hemipelvis, was left in situ. The patient's postoperative recovery was uneventful, and she was monitored periodically as follow‐up. At her 5‐year follow‐up visit, we assessed placental involution by measuring serum β human chorionic gonadotropin and by using color and pulsed Doppler sonography. The dynamics of the regression of placental volume yielded a bimodal curve: a phase of decrease over the first 2 months, coincident with a reduction in vascularization, followed by stability that lasted 6–8 months, and a second phase of gradual volume reduction. At 5 years, the placenta appeared as a small residual echogenic mass with no vascularity. The use of MRI in this case provided no additional information to what we found using sonography. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:39–43, 2003
Sonographic grading of fetal intracardiac echogenic foci in a population at low risk of aneuploidy
Authors: Wax Joseph R. , Cartin Angelina , Pinette Michael G. , Blackstone Jacquelyn , Michaud Janet , Byers Susan , Boutin Nancy
Published: December 2002

Purpose

We screened pregnant women at low risk of a fetal chromosomal abnormality for the presence of fetal intracardiac echogenic foci (ICEF) and graded those foci by using sonographic gain reduction. Our objectives were to determine the interobserver reliability of the technique and the association of ICEF, by grade, with fetal aneuploidy.

Methods

Pregnant women who were 18–35 years old, at low risk for fetal chromosomal abnormalities, and referred for targeted sonography at 16–24 weeks' menstrual age were eligible to participate. All patients whose fetuses had ICEF were offered fetal chromosomal analysis. The presence of ICEF was ascertained by an apical 4‐chamber view of the fetal heart and graded independently by 2 examiners blinded to each other's assessment. Grading was based on the difference in echogenicity of the ICEF and the thoracic spine as the ultrasound gain was reduced; in grade 1, the ICEF image was lost before that of the thoracic spine; in grade 2, the ICEF and thoracic spine images disappeared at the same gain setting; and in grade 3, the thoracic spine image was lost before that of the ICEF.

Results

During the 6‐month study period, 383 eligible women were examined, and ICEF were seen in 35 fetuses (9.1%): 25 (71.4%) in the left ventricle, 1 (2.9%) in the right ventricle, and 9 (25.7%) in both ventricles. ICEF grading was successfully performed in all 33 of the women with fetal ICEF who elected to participate. Twenty‐one (63.6%) had grade 1, 9 (27.3%) had grade 2, and 3 (9.1%) had grade 3 ICEF. Interobserver agreement was noted in 27 (90.0%) of 30 available paired second‐trimester observations (kappa = 0.8), indicating excellent agreement. Two fetuses (6.1%) with grade 1 ICEF but no other risk factors for aneuploidy had chromosomal abnormalities, as compared with 1 fetus (0.3%) in the control group, which had no ICEF (p = 0.02).

Conclusions

Sonographic grading of ICEF is feasible and reliable. The presence of fetal ICEF in a population otherwise at low risk for aneuploidy seems to warrant the performance of fetal chromosomal analysis. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:31–38, 2003
Three‐dimensional sonographic evaluation of the infant spine: Preliminary findings
Authors: Hughes Jacqueline A. , De Bruyn Rose , Patel Kalpana , Langford Sarah‐Jane , Thompson Dominic
Published: December 2002

Purpose

The aims of this study were to evaluate normal spinal anatomy in neonates and infants as seen by 3‐dimensional sonography (3D US), to determine the value of 3D US in the evaluation of occult spinal dysraphia in infants, and to correlate the findings of 3D US with those of 2‐dimensional sonography (2D US) and MRI, when available.

Methods

We used 2D US and 3D US to examine the lumbosacral spine in infants with cutaneous stigmata, syndromes associated with spinal dysraphia, and abnormal radiographs. We also evaluated, as controls, healthy infants who had no markers of spinal abnormality. 2D sonograms, 3D sonograms, radiographs, and MRI scans, when available, were compared to assess differences in the display of the infant spine.

Results

In total, we examined 29 infants: 18 subjects and 11 control infants. The correlation between 2D US and 3D US was 100% in the detection of congenital defects of the spinal cord, although 3D US allowed superior visualization of the vertebral bodies and posterior spinal elements. When a gross abnormality of the posterior spinal elements occurred with pathologic overlying soft tissue, interpretation was simpler with MRI than with sonography.

Conclusions

3D US is a useful adjunct to 2D US when screening the infant spine for congenital defects, particularly in showing alignment of posterior spinal elements and integrity of vertebral bodies. This ability is important because posterior spinal defects may be associated with underlying spinal cord abnormalities. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:9–20, 2003
Sonographic assessment of changes in thickness of different abdominal fat layers in response to diet in obese women
Authors: Sabir Nuran , Pakdemirli Emre , Sermez Yurdaer , Zencir Mehmet , Kazil Selcuk
Published: December 2002

Purpose

We evaluated the potential application of sonography to monitor alterations in abdominal fat thickness in obese women before and after dieting.

Methods

This study included 40 obese women (mean age, 42.2 ± 9.4 years; mean body mass index [BMI], 36.0 ± 5.9 kg/m2) who underwent a 3‐month low‐calorie diet. Height, weight, waist circumference (WC), and hip circumference (HC) were measured. BMI and waist‐to‐hip ratio (WHR) were calculated. Abdominal subcutaneous (S) and intra‐abdominal preperitoneal (P) fat were measured at their maximum (max) and minimum (min) thickness sites using a 7.5‐MHz linear‐array probe. Intra‐abdominal visceral (V) fat was measured using a 3.5‐MHz convex‐array probe. Measurements were taken before and after caloric restriction.

Results

The mean weight was reduced from 88.6 ± 17.1 kg to 83.0 ± 15.9 kg (p < 0.0001). The mean changes in Smin (r = 0.376, p = 0.017), Smax (r = 0.508, (p = 0.001), Pmin (r = 0.439, p = 0.005), and V (r = 0.365, p = 0.022) fat thicknesses were positively correlated with change in weight; the change in Pmax fat thickness showed the best and most significant correlation (r = 0.591, p < 0.0001). BMI (r = 0.969, p < 0.0001), WC (r = 0.510, p = 0.001), and HC (r = 0.422, p = 0.007) changes were also positively correlated with weight change, but the WHR change (r = 0.019, p > 0.05) was not.

Conclusions

All the abdominal fat layers, particularly the intra‐abdominal P fat, will decrease in response to loss of body fat by dieting. Sonography seems to be useful in monitoring small variations in the thicknesses of abdominal S and intra‐abdominal P and V fat. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:26–30, 2003
Cystic appearance of cervical lymph nodes is characteristic of metastatic papillary thyroid carcinoma
Authors: Kessler Ada , Rappaport Yoram , Blank Annat , Marmor Sylvia , Weiss Judith , Graif Moshe
Published: December 2002

Purpose

The usefulness of high‐resolution sonography in diagnosing cervical lymph node metastases from papillary thyroid carcinoma was investigated. The accuracy of a particular sign, cystic change within a node, in establishing the diagnosis was assessed.

Methods

The sonographic findings in 63 patients with enlarged cervical lymph nodes were retrospectively reviewed. The patients had undergone high‐resolution gray‐scale and color Doppler sonography followed by ultrasound‐guided fine‐needle aspiration (FNA) in all patients and surgical excision in 27 patients.

Results

Abnormal sonographic features were present in the lymph nodes of all 63 patients. In 14 (70%) of 20 patients with papillary thyroid carcinoma, sonography depicted cystic changes. This pattern was not found in any of the other 43 patients, in whom FNA revealed either metastasis from another malignancy (22 patients) or benign reactive lymphadenopathy (21 patients). Among the 63 patients, there were 43 true‐negative, 14 true‐positive, 6 false‐negative, and no false‐positive results in the diagnosis of metastatic papillary thyroid carcinoma using the presence or absence of an intranodal cystic area on sonography. These results yielded a 70% sensitivity, 100% specificity, 100% positive predictive value, 88% negative predictive value, and 90% overall accuracy for this criterion.

Conclusions

Cystic changes within a cervical lymph node are highly suggestive of metastatic papillary thyroid carcinoma. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:21–25, 2003
Effect of transvaginal sonography on the use of invasive procedures for evaluating patients with a clinical diagnosis of ectopic pregnancy
Authors: Atri Mostafa , Valenti David A. , Bret Patrice M. , Gillett Peter
Published: December 2002

Purpose

Our purpose was to determine the effect of transvaginal sonography (TVS) on the diagnostic evaluation of patients with suspected ectopic pregnancy (EP). Specifically, we wished to determine what effect TVS had on the use of invasive procedures.

Methods

This was a retrospective review of the medical records of 290 patients with a surgically documented diagnosis of EP. It included 147 consecutive patients from the era of use of suprapubic sonography (SPS) (1982–1987) and 143 consecutive patients from the era of use of TVS (1987–1995). We compared the percentages of patients who had undergone sonographic examinations, the rates of use of the invasive procedures dilatation and curettage (D&C) and diagnostic laparoscopy (DL), time from presentation to diagnosis, necessity for transfusion, status of EP at surgery, and various other characteristics of the patients (eg, demographics, serum level of β human chorionic gonadotropin, and presenting symptoms).

Results

In the SPS era, 46.9% of the patients had undergone sonography, compared with 78.3% in the TVS era (p = 0.001). Sonographic sensitivity was 60.9% in the SPS era and 93.8% in the TVS era (p = 0.001). D&C was performed in 53.1% and DL in 76.2% of patients in the SPS era, compared with 14.0% and 30.8%, respectively, in the TVS era (p = 0.001). In the last full year of the study, only 9% of the patients had undergone D&C and 9%, DL. The overall time from presentation to diagnosis significantly decreased from 45.6 hours in the SPS era to 16.8 hours in the TVS era (p = 0.002). We found no significant difference between the 2 eras in the need for transfusion and the percentage of ruptured EPs at surgery (p > 0.05).

Conclusions

The introduction of TVS has had an important effect on the evaluation of patients with EP by nearly eliminating the need for D&C and DL and permitting clinicians to take a more conservative approach to managing EP. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 31:1–8, 2003
Fully automated high yield synthesis of (R)‐ and (S)‐[11C]verapamil for measuring P‐glycoprotein function with positron emission tomography
Authors: Luurtsema Gert , Windhorst Albert D. , Mooijer Martien P.J. , Herscheid Jacobus D.M. , Lammertsma Adriaan A. , Franssen Eric J.F.
Published: December 2002

Racemic (±) verapamil is a well characterized substrate for P‐glycoprotein (P‐gp). However, the in vivo pharmacokinetics and pharmacodynamics of both enantiomers are reported to be different. In the preparation of evaluation studies of both enantiomers in animals and humans, the purpose of the present study was to optimize and automate the synthesis of (R)‐ and (S)‐[11C]verapamil.

(R)‐ and (S)‐[11C]verapamil were prepared from (R)‐ and (S)‐desmethyl‐verapamil, respectively, by methylation with no‐carrier added [11C]methyliodide or [11C]methyltriflate. Different conditions of the methylation reaction were studied: reaction time, temperature, base and solvent, and chemical form of the precursor using either the hydrochloric acid salt or the free base of the starting material. After optimization, the synthesis was fully automated using home‐made modules and performed according to GMP guidelines. Optimal yields of 60–70% for the methylation reaction were obtained using 1.5 mg of the free base of (R)‐ or (S)‐desmethyl‐verapamil in 0.5 ml of acetonitrile at 50°C for 5 min with [11C]methyltriflate as methylating agent. Under the same reaction conditions, but with a reaction temperature of 100°C, the radiochemical yield starting with [11C]methyliodide as methylation reagent was 40%. The specific activity of (R)‐ and (S)‐[11C]verapamil was >20 GBq/μmol and the radiochemical purity was >99% for both methods. The total synthesis time was 45 min. The automated high yield synthesis of (R)‐ and (S)‐[11C]verapamil provides the means for evaluating both enantiomers as in vivo tracers of P‐gp function. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of 18F labelled FK960, a candidate anti‐dementia drug, and PET studies in conscious monkeys
Authors: Murakami Yoshihiro , Nishimura Shintaro , Noda Akihiro , Harada Norihiro , Tsukada Hideo
Published: December 2002

The present study demonstrated the synthesis and in vivo study of 18F‐labeled N‐(4‐acetyl‐1‐piperazinyl)‐p‐fluorobenzamide (FK960) which is a novel anti‐dementia drug candidate. [18F]FK960 was prepared by a one‐pot, three reaction sequence, using nucleophilic fluorination, with an automated synthetic apparatus using either ethyl‐4‐trimethylammonium triflate (1a) or ethyl‐4‐nitrobenzoate (1b) as the precursor for labeling. Though 1a gave a higher yield, the specific activity was 50–100 fold higher with 1b. The radiochemical yield of [18F]FK960 was 7–15% (EOB) and the specific activity ranged from 2.0–60.2 GBq/μmol depending on the amount of F‐18 used. The synthesis time was 2.2–2.9 h. The obtained [18F]FK960 was injected into 3 conscious monkeys (100–120 MBq/kg body weight), and distribution images and pharmacokinetic data for [18F]FK960 showed similar uptake in different brain regions and 3‐fold higher levels of [18F]FK960 in blood relative to brain. Copyright © 2002 John Wiley & Sons, Ltd.
Reaction of [18F]4‐fluorobenzenediazonium cations with cysteine or the cysteinyl group: preparation of 18F‐labeled S‐aryl‐cysteine and a radiolabeled peptide
Authors: Patt J. T. , Patt M.
Published: December 2002

A reaction route for the preparation of no‐carrier‐added (n.c.a.) [18F]S‐4‐fluorophenylcysteine 7 via the [18F]‐4‐fluorobenzenediazonium ion 4 is described. The key step in this radiosynthesis is the reaction of 4 with cysteine forming [18F]4‐fluorophenyldiazocysteine 6, which is subsequently converted into 7 by irradiation with 366 nm light. 4 was synthesized by reacting 1,4‐dinitrobenzene 1 with [18F]‐fluoride in acetonitrile in a PEEK‐capillary in a microwave oven. After dilution of the reaction mixture with methanol, the resulting [18F]4‐fluoro‐1‐nitrobenzene 2 was submitted to reduction by means of H2 with Pd on C catalyst. The resulting [18F]4‐fluoroaniline 3 was purified by HPLC and diazotized to 4. The preparation of 4 was optimized with regard to yield and purity. The radiochemical yield of 6 was >90% (based on 3) while after UV irradiation and HPLC purification 45% of 7 (based on 3) was obtained (yields corrected for decay). The suitability of this method for labeling peptides with fluorine‐18 was demonstrated by application to the tripeptide, glutathione (GSH; γ‐L‐glutamyl‐L‐cysteinyglycine) 8. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of radiolabeled O6‐benzylguanine derivatives as new potential PET tumor imaging agents for the DNA repair protein O6‐alkylguanine‐DNA alkyltransferase
Authors: Zheng Qi‐Huang , Liu Xuan , Fei Xiangshu , Wang Ji‐Quan , Ohannesian David W. , Erickson Leonard C. , Stone K. Lee , Martinez Tanya D. , Miller Kathy D. , Hutchins Gary D.
Published: December 2002

Novel radiolabeled O6‐benzylguanine derivatives, 2‐amino‐6‐O‐[11C]‐[(methoxymethyl)benzyloxy]‐9‐benzyl purines ([11C]p‐O6‐AMBP, 1a; [11C]m‐O6‐AMBP, 1b; [11C]o‐O6‐AMBP, 1c), have been synthesized for evaluation as new potential positron emission tomography (PET) tumor imaging agents for the DNA repair protein, O6‐alkylguanine‐DNA alkyltransferase (AGT). The appropriate precursors for radiolabeling were obtained in three steps from starting material 2‐amino‐6‐chloropurine with moderate to excellent chemical yields. Tracers were prepared by O‐[11C]methylation of hydroxymethyl precursors using [11C]methyl triflate. Pure target compounds were isolated by solid‐phase extraction (SPE) purification procedure in 45–60% radiochemical yields (decay corrected to the end of bombardment), and a synthesis time of 20–25min. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of tertiary 14C‐labelled nonylphenol isomers
Authors: Vinken Ralph , Schmidt Burkhard , Schäffer Andreas
Published: December 2002

The ring‐14C‐labelled p‐nonylphenol (NP) isomers 4(3′,5′‐dimethyl‐3′‐heptyl)‐phenol (p353NP), 4(3′,6′‐dimethyl‐3′‐heptyl)‐phenol (p363NP) and 4(2′,6′‐dimethyl‐2′‐heptyl)‐phenol (p262NP) were synthesized for application in metabolism and sorption studies. Friedel–Crafts alkylation of 14C‐labelled phenol and the corresponding tertiary nonylalcohol with BF3 as catalyst was used. After clean‐up of p262NP and p363NP by preparative thin‐layer chromatography radiochemical yields amounted to 62.8 and 64.6%, specific radioactivities were 332 and 88.2 MBq/mmol, and radiochemical purities 97.6 and 99.0%. For both isomers, a large‐scale synthesis with non‐labelled phenol was additionally developed, which led to pure products (96 and 99%, respectively) without further purification steps. In the case of p353NP, which was formed as a diastereomeric mixture, the crude synthetic product had a radiochemical purity of 96.9% (radiochemical yield: 76.0%; specific activity: 298 MBq/mmol); thus, purification was not necessary. All products were characterized by means of gas chromatography‐mass spectroscopy, 1H‐ and 13C‐NMR, as well as IR. Copyright © 2002 John Wiley & Sons, Ltd.
Neural cell adhesion molecule‐mediated neurite outgrowth is repressed by overexpression of HES‐1
Authors: Jessen Ulla , Novitskaya Vera , Walmod Peter S. , Berezin Vladimir , Bock Elisabeth
Published: December 2002

The neural cell adhesion molecule (NCAM) stimulates neurite outgrowth by activating intracellular signaling cascades. We investigated the role of the transcriptional repressor HES‐1 in NCAM‐dependent neurite outgrowth by estimating neurite extension from PC12‐E2 cells grown in coculture with NCAM‐negative or NCAM‐positive fibroblasts. PC12‐E2 cells were transiently transfected with an expression plasmid encoding HES‐1. We found that expression of HES‐1 inhibited NCAM‐dependent neurite outgrowth. Treatment with arachidonic acid (an important messenger in NCAM‐dependent signaling) restored NCAM‐induced neurite outgrowth inhibited by HES‐1. These results suggest that HES‐1 is a regulator of intracellular signal transduction stimulated by cell adhesion molecules involved in neurite outgrowth. © 2002 Wiley‐Liss, Inc.
Expression of brain‐derived neurotrophic factor mRNA in rat hippocampus after treatment with antipsychotic drugs
Authors: Bai Ou , Chlan‐Fourney Jennifer , Bowen Rudy , Keegan David , Li Xin‐Min
Published: December 2002

Typical and atypical antipsychotic drugs, though both effective, act on different neurotransmitter receptors and are dissimilar in some clinical effects and side effects. The typical antipsychotic drug haloperidol has been shown to cause a decrease in the expression of brain‐derived neurotrophic factor (BDNF), which plays an important role in neuronal cell survival, differentiation, and neuronal connectivity. However, it is still unknown whether atypical antipsychotic drugs similarly regulate BDNF expression. We examined the effects of chronic (28 days) administration of typical and atypical antipsychotic drugs on BDNF mRNA expression in the rat hippocampus using in situ hybridization. Quantitative analysis revealed that the typical antipsychotic drug haloperidol (1 mg/kg) down‐regulated BDNF mRNA expression in both CA1 (P < 0.05) and dentate gyrus (P < 0.01) regions compared with vehicle control. In contrast, the atypical antipsychotic agents clozapine (10 mg/kg) and olanzapine (2.7 mg/kg) up‐regulated BDNF mRNA expression in CA1, CA3, and dentate gyrus regions of the rat hippocampus compared with their respective controls (P < 0.01). These findings demonstrate that the typical and atypical antipsychotic drugs differentially regulate BDNF mRNA expression in rat hippocampus. © 2002 Wiley‐Liss, Inc.
Dysmyelination induced in vitro by IgM antisulfatide and antigalactocerebroside monoclonal antibodies
Authors: Rosenbluth Jack , Moon David
Published: December 2002

Antiglycolipid antibodies cause a distinctive form of dysmyelination in vivo characterized by marked widening of the myelin period. Such “expanded” or “wide‐spaced” myelin occurs in peripheral nerves in certain paraproteinemias and in the CNS in multiple sclerosis. We have used an in vitro system to reproduce this pathology under controlled conditions to assess the role of antibody specificity and class and the need for cofactors in generating this kind of lesion in peripheral myelin. Schwann cell myelin formed in vitro around dorsal root ganglion cell axons was exposed for 3–14 days to hybridoma cells that produce specific monoclonal antibodies. Typical wide‐spaced myelin developed after exposure to either O4, which produces an IgM antisulfatide antibody, or O1, which produces an IgM antigalactocerebroside antibody. In both cases, the effect was apparent by three days in paranodal as well as internodal myelin, especially in the outer lamellae. This change did not depend on the presence of complement or macrophages in the cultures. Exposure to anti‐GalC hybridoma cells, which produce an IgG3 antiglycolipid antibody, did not produce wide‐spaced myelin, nor did exposure to hybridoma cells that secrete IgM antibodies directed against a non‐myelin antigen. The location and rapidity of the pathologic changes seen after O4 or O1 are consistent with penetration of the antibodies through the external mesaxon of already formed myelin and then between compact lamellae, progressively spreading them apart in the centripetal direction. This in vitro model shows that either of two specific monoclonal IgM antiglycolipid antibodies can alone reproduce a well known form of myelin pathology under defined conditions. © 2002 Wiley‐Liss, Inc.
Limited growth of severed CNS axons after treatment of adult rat brain with hyaluronidase
Authors: Moon Lawrence D. F. , Asher Richard A. , Fawcett James W.
Published: December 2002

Many chondroitin sulfate proteoglycans (CSPGs) have been shown to influence CNS axon growth in vitro and in vivo. These interactions can be mediated through the core protein or through the chondroitin sulfate (CS) glycosaminoglycan (GAG) side chains. We have shown previously that degrading CS GAG side chains using chondroitinase ABC enhances dopaminergic nigrostriatal axon regeneration in vivo. We test the hypothesis that interfering with complete CSPGs also limit axon growth in vivo. Neurocan, versican, aggrecan, and brevican CSPGs may be anchored within extracellular matrix through binding to hyaluronan glycosaminoglycan. We examine whether degradation of hyaluronan using hyaluronidase might release these inhibitory CSPGs from the extracellular matrix and thereby enhance regeneration of cut nigrostriatal axons. Anesthetized adult rats were given knife cut lesions of the right hemisphere nigrostriatal tract and cannulae were secured transcranially thereby allowing repeated perilesional infusion of saline or saline containing hyaluronidase once daily for 10 days post‐axotomy. Eleven days post‐transection brains from animals under terminal anesthesia were recovered for histological evaluation. Effective delivery of substance was inferred from the observed reduction in perilesional immunoreactivity for neurocan and versican after treatment with hyaluronidase (relative to saline). Immunolabeling using antibodies against tyrosine hydroxylase was used to examine the response of cut dopaminergic nigral neurons. After transection and treatment with saline, dopaminergic nigral neurons sprouted in a region lacking astrocytes, neurocan and versican. Axons did not regenerate into the lesion surround that contained astrocytes and abundant neurocan and versican. After transection and treatment with hyaluronidase, there was a significant increase in the number of cut dopaminergic nigral axons growing up to 800 μm anterior to the site of transection. However, cut dopaminergic nigral axons still did not regenerate into the lesion surround that contained reduced (albeit residual) neurocan and versican immunoreactivity. Thus, partial degradation of hyaluronan and chondroitin sulfate and depletion of hyaluronan‐binding CSPGs enhances local sprouting of cut CNS axons, but long‐distance regeneration fails in regions containing residual hyaluronan‐binding CSPGs. Hyaluronan, chondroitin sulfate and hyaluronan‐binding CSPGs therefore likely contribute toward the failure of spontaneous axon regeneration in the injured adult mammalian brain and spinal cord. © 2002 Wiley‐Liss, Inc.
mRNA expression of ephrins and Eph receptor tyrosine kinases in the neonatal and adult mouse central nervous system
Authors: Liebl Daniel J. , Morris Carol J. , Henkemeyer Mark , Parada Luis F.
Published: December 2002

Ephrins and Eph receptors are a family of molecules that have been implicated in axonal pathfinding. A unique feature of B‐class ephrins and Eph receptors is their ability to transmit bidirectional signals in both ephrin‐ and Eph receptor‐expressing cells upon cell–cell contact. These signals can lead to cytoskeletal alterations that have been attributed to regulating neuronal growth responses. Examination of gene‐target knockout mice has supported this hypothesis, revealing numerous developmental defects in the nervous systems of mice mutant for both B‐class ephrins and Eph receptors. To examine the potential scope of action for these genes in the nervous system, we have used in situ hybridization to study the mRNA expression of ephrins (B1, B2, and B3) and Eph receptors (B1, B2, B3, A4) in neonatal and adult mice. We found ephrins and Eph receptors to be expressed throughout the CNS. Expression was observed in the epithelium and migratory regions of the neonate and adult tissues as well as in discrete regions of high plasticity, including the adult olfactory bulb, hippocampus, and cerebellum. These studies suggest additional potential roles for these molecules in the postnatal and adult CNS and will serve as a guide in the detailed evaluation of mutant mice. © 2002 Wiley‐Liss, Inc.
Early programmed cell death in human NT2 cell cultures during differentiation induced by all‐trans‐retinoic acid
Authors: Guillemain I. , Fontès G. , Privat A. , Chaudieu I.
Published: December 2002

Previous studies have demonstrated that programmed cell death takes place at different stages during the development of the CNS in vivo. Our purpose in this study was to detect early programmed cell death associated with the induction of differentiation by retinoic acid (RA) in the NT2 cell line. By using the annexin V labeling as a marker of apoptosis, a significant apoptotic cell death was quantified during the third and the fourth days of the RA treatment. Double‐labeling studies using the staining of the genomic DNA strand breaks with the terminal deoxyribosyl‐transferase‐mediated dUTP nick end‐labeling (TUNEL) assay and either nestin or microtubule‐associated protein 2 (MAP2) showed that 1) the early apoptotic cell death affected mostly nestin‐positive cells and 2) after 8 days of differentiation, although cells with neuronal phenotypes are present, no colabeled TUNEL/MAP2 cells were detected. With regard to the neuronal protein MAP2, we observed discrete immunolabeling of a few NT2 cells as early as day 3 of the differentiation and a significant emergence of MAP2‐immunopositive cells at days 6–8. Thus, our results show that, when as a whole the differentiating NT2 cell population is considered, 1) the apoptotic cell death observed during the third day of differentiation occurs mostly in undifferentiated cells, 2) this process coincides with the first detection of the neuronal phenotype in NT2 cell cultures, and 3) the end of the cell death period in NT2 cell cultures is marked by both the accumulation of MAP2‐positive cells and the beginning of expression of the Bcl‐2 protein in the cultures. © 2002 Wiley‐Liss, Inc.
Molecular identity, synaptic localization, and physiology of calcium channels in retinal bipolar cells
Authors: Berntson Amy , Taylor W. Rowland , Morgans Catherine W.
Published: December 2002

Bipolar cells convey information through the retina via graded changes in their membrane potential and modulate transmitter release through the influx of calcium via L‐type calcium channels. However, the molecular identity of the α1 subunit has not been confirmed. We report the presence of the newly cloned α1F subunit in mouse bipolar cell synaptic terminals. The α1F subunits are localized to hot spots, possibly corresponding to active zones. We also report the physiological properties of two calcium currents present in mouse bipolar cells, a low‐voltage‐activated L‐type current and a low‐voltage‐activated T‐type calcium current. The physiological properties of the T‐type current suggest that it is completely inactivated under physiological conditions. The L‐type current may be mediated by the α1F subunit, and influx of calcium through the α1F channel may control neurotransmitter release from the bipolar cell terminal. © 2002 Wiley‐Liss, Inc.
Mouse brains deficient in H‐ferritin have normal iron concentration but a protein profile of iron deficiency and increased evidence of oxidative stress
Authors: Thompson Khristy , Menzies Sharon , Muckenthaler Martina , Torti Frank M. , Wood Teresa , Torti Suzy V. , Hentze Matthias W. , Beard John , Connor James
Published: December 2002

Several neurodegenerative disorders such as Parkinson's Disease (PD) and Alzheimer's Disease (AD) are associated with elevated brain iron accumulation relative to the amount of ferritin, the intracellular iron storage protein. The accumulation of more iron than can be adequately stored in ferritin creates an environment of oxidative stress. We developed a heavy chain (H) ferritin null mutant in an attempt to mimic the iron milieu of the brain in AD and PD. Animals homozygous for the mutation die in utero but the heterozygotes (+/−) are viable. We examined heterozygous and wild‐type (wt) mice between 6 and 8 months of age. Macroscopically, the brains of +/− mice were well formed and did not differ from control brains. There was no evidence of histopathology in the brains of the heterozygous mice. Iron levels in the brain of the +/− and wild‐type (+/+) mice were similar, but +/− mice had less than half the levels of H‐ferritin. The other iron management proteins transferrin, transferrin receptor, light chain ferritin, Divalent Metal Transporter 1, ceruloplasmin, were increased in the +/− mice compared to +/+ mice. The relative amounts of these proteins in relation to the iron concentration are similar to that found in AD and PD. Thus, we hypothesized that the brains of the heterozygote mice should have an increase in indices of oxidative stress. In support of this hypothesis, there was a decrease in total superoxide dismutase (SOD) activity in the heterozygotes coupled with an increase in oxidatively modified proteins. In addition, apoptotic markers Bax and caspase‐3 were detected in neurons of the +/− mice but not in the wt. Thus, we have developed a mouse model that mimics the protein profile for iron management seen in AD and PD that also shows evidence of oxidative stress. These results suggest that this mouse may be a model to determine the role of iron mismanagement in neurodegenerative disorders and for testing antioxidant therapeutic strategies. © 2002 Wiley‐Liss, Inc.
Cells exposed to a huntingtin fragment containing an expanded polyglutamine tract show no sign of ion channel formation: Results arguing against the ion channel hypothesis
Authors: Nørremølle Anne , Grunnet Morten , Hasholt Lis , Sørensen Sven Asger
Published: December 2002

Ion channels formed by expanded polyglutamine tracts have been proposed to play an important role in the pathological processes leading to neurodegeneration in Huntington's disease and other CAG repeat diseases. We tested the capacity of a huntingtin fragment containing an expanded polyglutamine tract to form ion channels in two cell types. Whole cell current from Xenopus oocytes was recorded using two‐electrode voltage‐clamp technique, and whole cell current from CHO‐K1 cells was recorded by patch‐clamp technique. The fragment with an expanded polyglutamine sequence induced no change in the currents recorded in any of the two expression systems, indicating no changes in ion channel activity. The results therefore argue against the proposed hypothesis of expanded polyglutamines forming ion channels. © 2002 Wiley‐Liss, Inc.