Combining gemcitabine with radiation in pancreatic cancer: understanding important variables influencing the therapeutic index

We compared and evaluated available laboratory and clinical data on the use of concurrent gemcitabine (Gemzar; Eli Lilly and Company, Indianapolis, IN) and radiation in pancreatic cancer to provide guidance for subsequent prospective research initiatives. Preclinical data suggest that the timing of administration of gemcitabine with respect to radiotherapy is important, but this issue has not yet been confirmed by clinical data. Phase I clinical data indicate that the amount of acute toxicity from the combination of gemcitabine and radiotherapy is strongly related to the dose and schedule of administration of gemcitabine, as well as to the radiation field size. There also appears to be an inverse linear relationship between the maximum tolerated gemcitabine dose and radiation dose. Also important, but less clear, is the infusion rate of gemcitabine as it relates to the systemic efficacy of the drug. The combination of additional agents with gemcitabine and radiation appears to be feasible. Finally, the addition of radioprotectors may enable chemotherapy dose escalation, but safe escalation of the radiotherapy dose with newer techniques has not been established. Semin Oncol 28 (suppl 10):25-33.

Preparation of collagen modified hyaluronan microparticles as antibiotics carrier

Hyaluronan (HA), a natural glycoaminoglycan featuring an extracellular matrix, has been suggested as an effective biocompatible material. In this study, the effectiveness of HA microparticles as a carrier system for antibiotics was evaluated, and their physicochemical characteristics were determined. Microparticles were fabricated by the gelation of sulfadiazine (SD) loaded HA solution with calcium chloride through either a granulation (GR-microparticles) or encapsulation (EN-microparticles) process, and atelocollagen was incorporated into the microparticles as an additive in order to improve their physical properties. The characteristics of the microparticles were examined by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and swelling test. In vitro release experiments were performed for 7 days and the released amount of SD was determined using high-performance liquid chromatography (HPLC). Microscopic observations revealed that the collagen incorporated HA particles had a more compact surface than the HA particles. DSC analysis determined a loss of SD crystallinity in the particles. Calcium chloride retarded the swelling of particles, whereas the loaded drug contents did not affect this property. Both GR-and EN-microparticles sustained SD release with initial bursting effect. SD release from EN-microparticles was faster than from GR-microparticles. In addition, the release rate was dependent on the SD content in the microparticles. These results suggest that collagen modified HA microparticles have a potential as a release rate controlling material for crystalline drugs such as SD.

Improved calcification resistance and biocompatibility of tissue patch grafted with sulfonated PEO or heparin after glutaraldehyde fixation

A novel chemical modification of biological tissues was developed aimed at improving biocompatibility and calcification resistance. This method involved the additional grafting of sulfonated PEO (PEO-SO(3)) or heparin after conventional glutaraldehyde (GA) fixation of bovine pericardium (BP). The amino groups of PEO-SO(3) or heparin were utilized to react to the GA residues to block them. The PEO-SO(3) or heparin grafted tissues demonstrated a slightly higher shrinkage temperature and tensile strength, but greater resistance to collagenase digestion, than GA treated ones. These results suggest that modified tissues have improved durability due to the grafting and filling effect of PEO-SO(3) or heparin in addition to the GA cross-linking. At the direct contact cytotoxicity test in vitro, PEO-SO(3) or heparin grafted tissue was shown to be nontoxic, while relatively significant cytotoxicity was observed for the GA treated tissues, possibly due to the release of GA. From the in vivo calcification study, calcium contents deposited on the modified tissues were much less than those on GA treated tissues. Such a decreased calcification might be explained by the decrease of residual GA groups during the additional treatment, and the space-filling effect and the nonadhesive property and/or the blood compatibility of PEO-SO(3) or heparin grafted covalently. The newly modified tissue patch was observed to show improved pathological assessibility including less inflammation and tissue reactions. This simple modification method may be useful for calcification-resistant and blood-compatible tissue patches for cardiovascular implants.

Zn(2+) induces stimulation of the c-Jun N-terminal kinase signaling pathway through phosphoinositide 3-Kinase

Zn(2+), one of the most abundant trace metal ions in mammalian cells, modulates the functions of many regulatory proteins associated with a variety of cellular activities. In the central nervous system, Zn(2+) is highly localized in the cerebral cortex and hippocampus. It has been proposed to play a role in normal brain function as well as in the pathophysiology of certain neurodegenerative disorders. We here report that Zn(2+) induced stimulation of the c-Jun N-terminal kinase (JNK) pathway in mouse primary cortical cells and in various cell lines. Exposure of cells to Zn(2+) resulted in the stimulation of JNK and its upstream kinases including stress-activated protein kinase kinase and mitogen-activated protein kinase kinase kinase. Zn(2+) also induced stimulation of phosphoinositide 3-kinase (PI3K) The Zn(2+)-induced JNK stimulation was blocked by LY294002, a PI3K inhibitor, or by a dominant-negative mutant of PI3Kgamma. Furthermore, overexpression of Rac1N17, a dominant negative mutant of Rac1, suppressed the Zn(2+)- and PI3Kgamma-induced JNK stimulation. The stimulatory effect of Zn(2+) on both PI3K and JNK was repressed by the free-radical scavenging agent N-acetylcysteine. Taken together, our data suggest that Zn(2+) induces stimulation of the JNK signaling pathway through PI3K-Rac1 signals and that the free-radical generation may be an important step in the Zn(2+) induction of the JNK stimulation.

Laparoscopy in the staging of pancreatic cancer

BACKGROUND

Over the past decade, laparoscopy has emerged as a popular method of detecting extrapancreatic metastatic disease in patients presumed to have localized pancreatic cancer.

METHODS AND RESULTS

The English language literature on laparoscopic staging of pancreatic cancer was reviewed. Interpretation of this literature on staging laparoscopy is difficult because (1) there has been inconsistent use of high-quality computed tomography (CT) in prospective studies, (2) many studies have included patients with locally advanced disease, and (3) the R0/R1/R2 resection rates among patients staged by laparoscopy have not been reported, making it impossible to correlate laparoscopic findings with the R0 resection rate. Laparoscopy may prevent unnecessary laparotomy in a proportion of CT-staged patients presumed to have resectable pancreatic cancer. However, routine laparoscopy is performed on patients judged to have resectable disease by high-quality CT, this fraction of patients is between 4 and 13 per cent.

CONCLUSION

When state-of-the-art CT is available, the routine use of staging laparoscopy may not be easily justified from the data in the recent literature. Selective use of laparoscopy may be more appropriate and will probably be a more cost-effective staging approach. Criteria are presented for the selective use of laparoscopy in the staging of patients with localized pancreatic cancer.

Characterization of UV-irradiated dense/porous collagen membranes: morphology, enzymatic degradation, and mechanical properties

Collagen-based membranous materials of various shapes (gel, film, sponge) are known to be the most promising materials in terms of facilitating the regeneration of dermal defects. In this study, dense and porous collagen membranes were fabricated using air-drying and freeze-drying processes, respectively, and the effect of ultraviolet (UV) radiation on the degree of membrane crosslinking was evaluated by in vitro biodegradation and mechanical testing. A non-irradiated membrane group was used as the negative control and a glutaraldehyde (GA) treated group as the positive control. Scanning electron microscopy showed that, as the freezing temperature decreased to -196 degrees C, the resultant mean pore sizes also decreased; optimal pore size was obtained at a freezing temperature of -70 degrees C. In vitro biodegradation and mechanical testing demonstrated that GA treatment or 4 hours of exposure to UV radiation significantly increased both resistance to collagenase and mechanical strength versus the untreated controls, regardless of the collagen membrane type (dense or porous). Our results suggest that UV treatment is a useful tool for the fabrication of collagen membranes designed to be used as dermal dressings.

Cigarette use by college students in smoke-free housing: results of a national study

BACKGROUND

Cigarette-smoking rates have increased in recent years among college students. Smoke-free residences offer a possible means of reducing or preventing smoking. However, their use has as yet not been evaluated. This paper examines whether students residing in smoke-free residences are less likely to smoke cigarettes than students in other campus residences, and if such lower rates apply to all types of students and colleges.

METHODS

The Harvard School of Public Health College Alcohol Study surveyed a nationally representative sample of college students at 128 U.S. 4-year colleges regarding tobacco use and related behaviors in the spring of 1999. The responses of students living in smoke-free and unrestricted residences at 101 campuses were compared.

RESULTS

Current smoking prevalence was significantly lower among residents of smoke-free housing (21.0%) as compared with residents of unrestricted housing (30.6%, p<0.0001). The lower rate of current cigarette use was consistent with all types of student and college characteristics with few exceptions. Current cigarette use was significantly lower for those living in smoke-free housing than for residents of unrestricted housing among students who were not regular smokers before age 19 (10% vs 16.9%, p<0.0001), but not among students who smoked regularly before age 19.

CONCLUSIONS

Smoke-free residences may help protect those students who were not regular smokers in high school from smoking in college. However, the difference in smoking rates may be due to self-selection of students into smoke-free residences. Since smoke-free options also protect students from second-hand smoke and dormitory fires, colleges should provide these types of residences for all students who request them, and should also encourage others to choose them.

Relationships between dietary intake and cognitive function level in Korean elderly people

We examined the relationship between dietary intake and cognitive performance in Korean elderly people. Data for dietary intake, anthropometric measurements and cognitive function tests were collected and the relationships of the variables were analyzed. A random sample of 210 men and 239 women in Korea, aged 60 and over, was selected. Subjects were free-living elderly people who had not experienced major cognitive function impairment. Main outcome measures, 24 h dietary recall method, food behaviour variables, anthropometrics indices, health variables, and Kwon's Mini-Mental State Examination for Koreans (MMSE-K) for cognitive function test. The prevalence rate of poor cognitive function (MMSE-K score < or = 19) of Korean elderly was 22.3%: women with poor cognitive function had a higher rate (31.0%) than that in men (12.3%). Cognitive ability was related negatively with age and positively with school education level. Female subjects of poor cognitive function had significantly lower intakes of total amount of foods, cereals, vegetables, fruits, milk, spices, and also, energy, protein, fat, carbohydrate, Ca, P, Fe, vitamin A, thiamin, riboflavin, and niacin than those of the normal cognitive score (> or = 24) group (P < 0.05). Male subjects of poor cognitive function had significantly lower intakes of fruits, fiber, and vitamin C than the normal subjects (P < 0.05). The MMSE-K score of female subjects showed a significant positive correlation with total amount of foods, cereals, beans, fruits, milk, oil, spices, and energy, protein, fat, carbohydrate, Ca, Fe, P, riboflavin and niacin intakes. The consumption of adequate nutrients, by taking sufficient amounts and variety of foods, may be important in maintaining adequate cognitive function in elderly Koreans.

Alcohol use and problems at colleges banning alcohol: results of a national survey

OBJECTIVE

This study examines student alcohol use and associated problems, including drinking and driving, at U.S. colleges that ban alcohol for all students on campus.

METHOD

A nationally representative sample of students (N = 11,303, 61% women) attending U.S. colleges completed questionnaires regarding alcohol use and related behaviors in the spring of 1999. The responses of 2,252 students at 19 ban schools were compared with those of 9,051 students at 76 nonban schools.

RESULTS

Students at ban colleges were 30% less likely to be heavy episodic drinkers and more likely to abstain from alcohol. The lower rates of heavy episodic drinking apply to students whether or not they were heavy episodic drinkers in high school. However, among drinkers, students at ban schools engaged in as much extreme drinking as drinkers at schools that do not ban alcohol and experienced the same rate of alcohol-related problems. At schools that ban alcohol, fewer students experienced secondhand effects of the drinking of others than did students at nonban schools. Students at ban schools were not more likely to drink and drive than were students at nonban schools.

CONCLUSIONS

A campus ban on alcohol may support abstention from alcohol use and reduce heavy episodic drinking and the associated secondhand effects in college. Since this is a correlational study, we cannot determine whether the lower rates of heavy episodic drinking are due to the ban or to other factors (e.g., self-selection of students to these schools). Ban schools do not enroll fewer high school heavy episodic drinkers.

Neoadjuvant chemoradiotherapy for adenocarcinoma of the pancreas: treatment variables and survival duration

BACKGROUND

For patients with potentially resectable pancreatic cancer, the poor outcome associated with resection alone and the survival advantage demonstrated for combined-modality therapy have stimulated interest in preoperative chemoradiotherapy. The goal of this study was to analyze the effects of different preoperative chemoradiotherapy schedules, intraoperative radiation therapy, patient factors. and histopathologic variables on survival duration and patterns of treatment failure in patients who underwent pancreaticoduodenectomy for adenocarcinoma of the pancreatic head.

METHODS

Data on 132 consecutive patients who received preoperative chemoradiation followed by pancreaticoduodenectomy for adenocarcinoma of the pancreatic head between June 1990 and June 1999 were retrieved from a prospective pancreatic tumor database. Patients received either 45.0 or 50.4 Gy radiation at 1.8 Gy per fraction in 28 fractions or 30.0 Gy at 3.0 Gy per fraction in 10 fractions with concomitant infusional chemotherapy (5-fluorouracil, paclitaxel, or gemcitabine). If restaging studies demonstrated no evidence of disease progression, patients underwent pancreaticoduodenectomy. All patients were evaluated with serial postoperative computed tomography scans to document first sites of tumor recurrence.

RESULTS

The overall median survival from the time of tissue diagnosis was 21 months (range 19-26, 95%CI). At last follow-up, 41 patients (31%) were alive with no clinical or radiographic evidence of disease. The survival duration was superior for women (P = .04) and for patients with no evidence of lymph node metastasis (P = .03). There was no difference in survival duration associated with patient age, dose of preoperative radiation therapy, the delivery of intraoperative radiotherapy, tumor grade, tumor size, retroperitoneal margin status, or the histologic grade of chemoradiation treatment effect.

CONCLUSION

This analysis supports prior studies which suggest that the survival duration of patients with potentially resectable pancreatic cancer is maximized by the combination of chemoradiation and pancreaticoduodenectomy. Furthermore, there was no difference in survival duration between patients who received the less toxic rapid-fractionation chemoradiotherapy schedule (30 Gy, 2 weeks) and those who received standard-fractionation chemoradiotherapy (50.4 Gy, 5.5 weeks). Short-course rapid-fractionation preoperative chemoradiotherapy combined with pancreaticoduodenectomy, when performed on accurately staged patients, maximizes survival duration and is associated with a low incidence of local tumor recurrence.

Mammalian augmenter of liver regeneration protein is a sulfhydryl oxidase

BACKGROUND

Augmenter of Liver Regeneration is an important secondary hepatic growth factor. Augmenter of liver regeneration protein has been shown to control mitochondrial gene expression and the lytic activity of liver-resident Natural Killer cells through the levels of interferon-gamma, but the precise enzymatic function of this protein is unknown.

AIMS

To define the enzymatic activity of augmenter of liver regeneration protein. The carboxy terminus of augmenter of liver regeneration protein contains a special CXXC motif characteristic for redox proteins and with faint homologies to the redox-active site of sulfhydryl oxidases. Tests were, therefore, carried out to establish whether isolated augmenter of liver regeneration protein can also function in the formation of sulfur bridges.

METHODS

Purified augmenter of liver regeneration proteins from rat and human were tested in enzyme assays for the ability to introduce disulfide bonds into protein substrates. The isolated proteins were tested for the formation of dimers and the presence of bound FAD was investigated spectroscopically. The function of the conserved CXXC motif was investigated by in vitro mutagenesis experiments and subsequent enzyme assays.

RESULTS

In this study, we demonstrate that rat and human augmenter of liver regeneration protein are flavin-linked sulfhydryl oxidases that catalyze the formation of disulfide bonds in reduced protein substrates. A flavin moiety is firmly but not covalently attached to the protein. In human cell cultures augmenter of liver regeneration protein is expressed in a long and short form that both exist as covalently linked dimers. The active site of the enzyme is associated with a conserved CXXC motif in the carboxy-terminal domain, that is present in the homologous proteins from yeast to humans and also in the human Q6 growth regulator protein. In vitro mutagenesis of one cysteine residue in the CXXC motif results in loss of enzymatic function and the mutated protein no longer binds FAD.

CONCLUSIONS

For the first time, these data assign an enzymatic activity to the important hepatic growth factor augmenter of liver regeneration protein. The finding that augmenter of liver regeneration protein acts as a FAD-linked sulfhydryl oxidase is essential to identify the molecular targets inside liver cells and to elucidate the precise role of mammalian augmenter of liver regeneration protein in hepatic cell growth, liver disease and regeneration.

Significance of plasma cytokine levels in melanoma patients with histologically negative sentinel lymph nodes

INTRODUCTION

Although sentinel lymph node (SLN) status is the most powerful predictor of prognosis in patients with clinically localized melanoma, a proportion of melanoma patients with histologically negative SLNs will still recur. It is hypothesized that tumor response may be altered or mediated by specific cytokines. We therefore investigated whether levels of IL-4, IL-6, IL-10, TNF-alpha, or IFN-gamma would predict disease recurrence in melanoma patients with histologically negative SLNs.

METHODS

This prospective cohort study involved 218 patients with clinically localized melanoma who underwent a histologically negative SLN biopsy. Preoperative plasma cytokine levels were determined by enzyme-linked immunosorbent assay on these patients, as well as on 90 healthy controls. Kaplan-Meier life tables were constructed, and Cox proportional hazards analyses were performed to assess predictors of disease-free survival (DFS).

RESULTS

At a median follow-up of 43 months, 33 of 218 patients (15%) had suffered disease recurrence. Melanoma patients had significant elevations of IL-4, IL-6, and IL-10 compared to healthy controls; levels of IFN-gamma were less elevated in melanoma patients compared to controls. Despite this, melanoma patients with detectable IFN-gamma levels were at significantly higher risk for recurrence compared to patients with undetectable levels (5-year DFS 70% vs. 86%, P = .03). On multivariate analysis including standard melanoma prognostic factors, only tumor thickness (P = .004) and the presence of detectable IFN-gamma levels (P = .05) were significant independent prognostic factors for disease-free survival.

CONCLUSIONS

Among melanoma patients with clinically localized disease who have undergone a histologically negative SLN biopsy, presence of a detectable plasma level of IFN-gamma is an independent predictor of disease recurrence. Elevated levels of IFN-gamma may identify a group of early-stage melanoma patients who are more likely to have recurrence of disease and who may benefit from adjuvant therapies, including immunotherapies.

Methyl-substituted diindolylmethanes as inhibitors of estrogen-induced growth of T47D cells and mammary tumors in rats

Diindolylmethane (DIM) is formed by acid catalyzed dimerization of the phytochemical indole-3-carbinol, and both compounds inhibit formation and/or growth of mammary tumors in rodents. In this study, we have investigated the aryl hydrocarbon receptor (AhR) agonist activity and inhibitory AhR-estrogen receptor crosstalk induced by the following methyl-substituted DIMs: 1,1'-dimethyl-, 2,2'-dimethyl-, 5,5'-dimethyl-, 6,6'-dimethyl-, and 7,7'-dimethylDIM and 1,1',2,2'-tetramethylDIM. The six compounds bound to the rat cytosolic AhR in a transformation assay but, at concentrations < or = 10 microM, exhibited minimal to non-detectable AhR agonist or antagonist activities associated with CYP1A1 induction. In contrast, the methyl-substituted DIMs inhibited estrogen-induced T47D human breast cancer cell growth and the four most active compounds (1,1'-, 2,2'-, 5,5'-dimethylDIM and 1,1',2,2'-tetramethylDIM) inhibited one or more estrogen-induced responses in the 21-day-old female B6C3F1 mice at a dose of 100 mg/kg/day (X3). Induction of hepatic CYP1A1-dependent activity was not observed at this high dose. The antitumorigenic activity of these compounds was examined in 7,12-dimethylbenz[a]anthracene-induced rat mammary tumor model in which the DIM analogs were orally administered (by gavage in corn oil) at a dose of 1 mg/kg/day (X10). 1,1'-DimethylDIM, 5,5'-dimethylDIM and 1,1',2,2'-tetramethylDIM significantly inhibited mammary tumor growth, and this was not accompanied by changes in organ/body weights or histopathology. These studies demonstrate that methyl-substituted DIMs are selective AhR modulators (SAhRMs) with potential for clinical treatment of breast cancer.

Laparoscopy in the staging of pancreatic cancer

BACKGROUND

Over the past decade, laparoscopy has emerged as a popular method of detecting extrapancreatic metastatic disease in patients presumed to have localized pancreatic cancer.

METHODS AND RESULTS

The English language literature on laparoscopic staging of pancreatic cancer was reviewed. Interpretation of this literature on staging laparoscopy is difficult because (1) there has been inconsistent use of high-quality computed tomography (CT) in prospective studies, (2) many studies have included patients with locally advanced disease, and (3) the R0/R1/R2 resection rates among patients staged by laparoscopy have not been reported, making it impossible to correlate laparoscopic findings with the R0 resection rate. Laparoscopy may prevent unnecessary laparotomy in a proportion of CT-staged patients presumed to have resectable pancreatic cancer. However, routine laparoscopy is performed on patients judged to have resectable disease by high-quality CT, this fraction of patients is between 4 and 13 per cent.

CONCLUSION

When state-of-the-art CT is available, the routine use of staging laparoscopy may not be easily justified from the data in the recent literature. Selective use of laparoscopy may be more appropriate and will probably be a more cost-effective staging approach. Criteria are presented for the selective use of laparoscopy in the staging of patients with localized pancreatic cancer.

Behavior of osteoblasts on a type I atelocollagen grafted ozone oxidized poly L-lactic acid membrane

With oxidizing poly-L-lactic acid (PLLA) surface by ozone, peroxide groups are easily generated on the surface. Those peroxides are broken down by redox-coupling reaction, and provide active species that initiate grafting by reaction with the collagen molecules. The surface density of generated peroxide on a PLLA surface was determined by an iodide method. The maximum concentration of peroxide was about 2.87 x 10(-8) mol/cm2 when ozone oxidation was performed at 60 V for 60 min. After the surface oxidation, type I atelocollagen was grafted onto PLLA surface. All physical measurements on the collagen-grafted surface indicated that the PLLA surface was effectively grafted with type I atelocollagen. Behavior of rat calvaria osteoblasts on type I atelocollagen grafted PLLA (PLLA + COL) surface was observed. Initial attachment of osteoblasts on the surface was significantly enhanced, and it is assumed that the atelocollagen matrix supported the initial attachment and growth of cells. Collagenous protein synthesis of osteoblasts was maintained at relatively low level in the early stage of proliferation due to the primarily existing grafted type I atelocollagen, and then increased in 7 days as the osteoblast differentiated. After 7 days, collagenous protein synthesis in osteoblasts was activated. Alkaline phosphatase (ALPase) activity and mineralization by osteoblasts were promoted on PLLA + COL surface. In comparison with PLLA + COL, non-treated PLLA and tissue culture plate (TCPS) did not show any feature expressed in osteoblasts' maturation up to 9 days in this experiment. The grafted type I atelocollagen provided a favorable matrix for cell migration in relation with collagenase expression. Ozone oxidation might be a favorable method for surface modification of PLLA membranes by collagen grafting, and cell behavior could be modulated by the grafted collagen.

Studies on the changes of c-fos protein in spinal cord and neurotransmitter in dorsal root ganglion of the rat with an experimental peripheral neuropathy

Animal models for human chronic pain syndromes have been developed and widely used for pain research. One of these neuropathic pain models by Kim and Chung (1992) has many advantages for operation and pain elicitation. In this neuropathic model we have examined the c-fos protein, substance P, CGRP immunoreactivity in dorsal root ganglia and dorsal horn. 50 Sprague-Dawley rats were used for this study. L5 and L6 spinal nerves were ligated tightly to produce the neuropathic pain model. After 2, 4, 8, 16, and 24 hours and 1 week of surgery, rats were anesthetized and sacrificed by perfusion. After confirmation of the roots transected by the surgery, the L5 and L6 dorsal root ganglions and spinal cord were removed and processed for immunohistochemistry. All tissue sections were immunohistochemically stained for substance P, CGRP and c-fos using the peroxidase-antiperoxidase (PAP) method. The number of immunostained substance P and CGRP dorsal root ganglion cells and c-fos immunoreactive dorsal horn cells were counted and analyzed statistically with Mann-Whitney U test. The results are as follows. The number of c-fos protein immunoreactive neurons in the superficial layer of dorsal horn were increased markedly 2 hours after operation, and gradually decreased to normal level 1 week after operation. The number of c-fos protein immunoreactive neurons in the deep layer of the dorsal horn gradually increased to a peak 24 hours after operation, then decreased to the normal level 1 week after operation. The number of substance P and CGRP immunoreactive L5 and L6 dorsal root ganglion neurons were decreased markedly 1 week after the pain model operation. In conclusion, after neuropathic pain model operation, c-fos proteins were immediately expressed in the superficial layer of spinal dorsal horn, thereafter c-fos proteins in the deep layer of spinal dorsal horn were expressed. CGRP and substance P immunoreactive neurons in DRG were decreased markedly 1 week after neuropathic pain model operation. These decrements do not coincide with the other chronic pain models, which show great increases in these pain transmitting substances. Therefore, the relationship between pain and c-fos, SP and CGRP should be investigated further.

Developmental windows of differential lead-induced immunotoxicity in chickens

The developing immune system of rodents has been shown to exhibit increased sensitivity to lead-induced immunotoxicity compared with that of adults. However, little is known about potential windows of increased vulnerability during discrete periods of embryonic development. To investigate differential embryonic sensitivity to lead-induced immunotoxicity, sublethal doses of lead ranging from 5 to 400 microg/egg were introduced into fertilized Cornell K Strain White Leghorn chicken eggs via the air sac at one of four different stages of embryonic development (5, 7, 9, and 12 days of incubation, designated as E5, E7, E9, and E12, respectively). Lead levels of blood and bone were determined at hatching and lead-induced immunotoxicity was evaluated in 5-6 week old young chickens using a delayed-type hypersensitivity (DTH) reaction against bovine serum albumin (BSA), macrophage production of nitric oxide, and interferon-gamma (IFN-gamma) production by splenic lymphocytes as immune indicators. Splenic lymphocyte production of IFN-gamma was significantly suppressed (measured for E7 and E9 exposures only, P<0.05) among lead treated groups when compared with controls. Macrophage production of nitric oxide (measured as nitrite production) was significantly depressed (P<0.05) following E5, E7, and E9 lead exposures but not following E12 lead exposure. In contrast with this pattern, DTH function was unaltered following the E5, E7, and E9 exposures, but was significantly depressed (P<0.05) after E12 exposure to lead. Since the same lead dose (200 microg/egg) given at E9 and E12 produced the same blood and bone lead levels and resulted in a different outcome regarding DTH function, the capacity of lead to influence DTH function appeared to emerge between days 9 and 12 of in ovo development. Based on these results, it is hypothesized that lead exposure during different windows of embryonic development is likely to result in different immunotoxic outcomes in the juvenile.

The treatment of lacrimal apparatus obstruction with the use of an inner canthal Jones tube insertion via a transcaruncular route

BACKGROUND AND OBJECTIVE

To evaluate the clinical utility of the lacrimal bypass surgery using Bowman's probe in treatment of obstruction of the lacrimal apparatus.

PATIENTS AND METHODS

This study evaluated 124 cases of obstruction of the lacrimal passage systems with mean epiphora of 2.7 years. An incision was made on the side of the caruncle, and the lacrimal bone was penetrated between the lacrimal sac and the nasal mucosa by Bowman #0. Insertion of a Jones tube was made at the new lacrimal pathway, a puctum dilator or scissors was introduced through the caruncle and dilated across the lacrimal bone into the nasal cavity. The Jones tube was introduced over the probe into the nasal cavity, and fixed at the caruncle with nonabsorbable suture material.

RESULTS

Complete resolution of epiphora was accomplished in 120 (96.8%) of 124 eyes; only 4 (3.2%) eyes failed during a mean of 17.1 months of follow-up.

CONCLUSION

This procedure is simple and safe with no facial scarring, short operation time, high success rate, and can be performed under local anesthesia. Therefore, the clinical utility of this procedure seems to be of value in treatment of complicated obstruction of the lacrimal apparatus.

Expression, purification, crystallization and preliminary X-ray analysis of Escherichia coli 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase

A recombinant form of Escherichia coli 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (E.C. 3.2.2.9) has been purified to homogeneity and crystallized using the hanging-drop vapour-diffusion technique. While several different crystallization conditions were obtained, only one set of conditions yielded crystals suitable for X-ray diffraction analysis. These crystals grow as diamond-shaped wedges, with unit-cell parameters a = 50.92, b = 133.99, c = 70.88 A, alpha = beta = gamma = 90 degrees. The crystals belong to space group P2(1)2(1)2 and diffract to a minimum d spacing of 2.3 A on a MAR345 image plate with a Rigaku RU-200 rotating-anode X-ray generator. On the basis of density calculations, two monomers are predicted per asymmetric unit (Matthews coefficient, V(M) = 2.37 A(3) Da(-1)), with a solvent content of 48%.

Drinking levels, alcohol problems and secondhand effects in substance-free college residences: results of a national study

OBJECTIVE

This study examines alcohol use, associated problems and secondhand effects among residents of substance-free and alcohol-free housing on U.S. college campuses.

METHOD

In the spring of 1999, a nationally representative sample of students completed survey questionnaires regarding alcohol use and related behaviors. The responses of 2,555 (61.25% female) students living in different types of residences (substance-free, alcohol-free and unrestricted) at the 52 campuses at which these housing options existed were compared.

RESULTS

Substance-free residences were not substance-free; however, residents drank less heavily and experienced fewer alcohol-related problems and secondhand effects than students living in unrestricted housing. They were less likely (three fifths) to engage in heavy episodic drinking. The difference between students in substance-free and unrestricted housing was greatest for students who had not been heavy episodic drinkers in high school and for those on campuses with lower overall levels of heavy episodic drinking. In contrast, students who lived in alcohol-free halls were no less likely to be heavily involved in alcohol use than were students in unrestricted housing.

CONCLUSIONS

Residence in substance-free housing was associated with lower likelihood of heavy episodic drinking in college for students who were not heavy episodic drinkers in high school. Whether or not this is a causal relationship or a result of self-selection needs to be examined in a prospective study. These living arrangements are also associated with lower levels of secondhand effects. College administrators may want to consider offering or increasing their substance-free housing options as one possible method of decreasing heavy student drinking.

Type I atelocollagen grafting onto ozone-treated polyurethane films: cell attachment, proliferation, and collagen synthesis

An approach is presented for the graft copolymerization of type I atelocollagen onto the surface of polyurethane (PU) films treated with ozone. Through inducing oxidization to modify PU surface by ozone, peroxide groups are easily generated on the surface. Those peroxides are broken by redox-polymerization, and provide active species which initiate graft polymerization by reacting with amines in the collagen molecules. The ozone oxidation time and voltage could readily control the amount of peroxide production. The surface density of generated peroxides on PU surface was determined by iodide method. The maximum concentration of peroxide was about 10.20 x 10(-8)mol/cm(2) when ozone oxidation was performed at 60 V for 30 min. After the reaction of PU by ozone oxidation, type I atelocollagen was graft-copolymerized onto the PU film. All the physical measurements on the collagen-grafted surface indicated that the PU surface was effectively covered with type I atelocollagen. The interaction of the collagen-grafted PU surface with fibroblasts could be greatly enhanced by the surface graft polymerization with type I atelocollagen. Attachment and proliferation of fibroblasts on the grafted type I atelocollagen were significantly enhanced, and it is assumed that the atelocollagen matrix supported the initial attachment and growth of cells. In the early stage of proliferation, collagen synthesis in fibroblasts was not activated and remained at a relatively low level due to the grafted type I atelocollagen, increasing only with fibroblast differentiation.

3',4'-dimethoxyflavone as an aryl hydrocarbon receptor antagonist in human breast cancer cells

Treatment of MCF-7 and T47D human breast cancer cells with 3', 4'-dimethoxyflavone (3',4'-DMF) alone did not induce CYP1A1-dependent ethoxyresorufin O:-deethylase (EROD) activity or reporter gene activity in cells transfected with an aryl hydrocarbon (Ah)-responsive construct (pRNH11c). In contrast, 1 nM 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) induced up to a 50- to 80-fold increase in EROD and reporter gene activity in MCF-7 and T47D cells. In cells cotreated with 1 nM TCDD plus 0.1-10 microM 3',4'-DMF, there was a concentration-dependent decrease in the TCDD-induced responses, with 100% inhibition observed at the 10 microM concentration. Gel mobility shift assays using rat liver cytosol and breast cancer cell nuclear extracts showed that 3',4'-DMF alone did not transform the AhR to its nuclear binding form, but inhibited TCDD-induced AhR transformation in rat liver cytosol and blocked TCDD-induced formation of the nuclear AhR complex in MCF-7 and T47D cells. TCDD also inhibited estrogen-induced transactivation in MCF-7 cells, and this response was also blocked by 3',4'-DMF, confirming the AhR antagonist activity of this compound in breast cancer cells.

Limitations of size as a criterion in the evaluation of adrenal tumors

BACKGROUND

Size has been considered to be the single best predictor of malignancy in adrenal neoplasms that have been identified incidentally. However, small adrenal cortical cancers have been reported from multiple centers.

METHODS

We retrospectively evaluated the value of tumor size and other clinical parameters in the prediction of the presence of adrenal malignancy.

RESULTS

The records of 117 patients who underwent evaluation for tumors of the adrenal gland were reviewed. The median tumor size of the adrenal cortical carcinomas (n = 38 carcinomas) was 9.2 cm (range, 1.7-30 cm); 5 cancers (13.5%) were smaller than 5.0 cm. The median overall size of the benign tumors, excluding pheochromocytomas, was 4.0 cm (n = 38 carcinomas); 10 benign tumors (26%) were larger than 5.0 cm. The imaging features of 4 of 5 small adrenal cancers predicted malignancy; the remaining patients had hormonally functioning tumors. The imaging features of 7 of 10 large benign adrenal tumors predicted benign histologic features, including 5 of 5 myelolipomas.

CONCLUSIONS

Although size remains a good predictor of the histologic features and clinical behavior of adrenal neoplasms, both small adrenal cortical cancers and large benign tumors occur with measurable frequency. High-quality imaging studies may be helpful in the identification of relatively small adrenal cancers and of characteristic benign lesions that may be selectively followed.

Peroxiredoxin is ubiquitously expressed in rat skin: isotype-specific expression in the epidermis and hair follicle

Peroxiredoxins are a family of peroxidases that are ubiquitously and abundantly expressed in mammalian tissues; however, comparatively less is known about their expression in the skin. In this study, we examined the expression of three isotypes of peroxiredoxins (I-III) in rat skin. Western blot analyses showed strong expression of peroxiredoxins I-III in the epidermis and dermis of intact skin. Additionally, they were expressed in cultured rat keratinocytes and fibroblasts. Confocal image analyses revealed that peroxiredoxin II was present in the cytoplasm as a diffuse, reticulated pattern. In immunohistochemical staining of rat skin, peroxiredoxin expression was mainly localized to the epidermis, hair follicles, and sebaceous glands. In the epidermis, peroxiredoxins I and II were expressed in all layers with a gradient of increasing expression to the granular layer. In contrast, peroxiredoxin III was expressed in all layers with a gradient of expression decreasing to the granular layer. In the hair follicle, peroxiredoxins I-III were mainly expressed in the outer root sheath, except peroxiredoxin II, which was strongly expressed in the inner root sheath. In situ hybridization showed that mRNA expression was commensurate with the level of protein. Ultraviolet B radiation increased peroxiredoxin II expression in rat skin within 15 min after irradiation. From this study we conclude that peroxiredoxin isoforms are ubiquitously expressed in rat skin, and expression of at least peroxiredoxin II can be regulated by ultraviolet irradiation as a peroxidase in the skin. J Invest Dermatol 115:1108-1114 2000