Over-expression of nucleophosmin/B23 decreases the susceptibility of human leukemia HL-60 cells to retinoic acid-induced differentiation and apoptosis

Stable clones of HL-60 cells in which nucleophosmin/B23 was over-expressed were established. Less percentages (4-20%) of nucleophosmin/B23 over-expressed (pCR3-B23) cells exhibited the morphological characteristic of apoptosis as compared with control vector-transfected (pCR3) cells (6-53%) during the 10 microM RA treatment for 1-4 days. In flow cytometry analysis, a block in the G1 phase was noted in all the pCR3-B23 and pCR3 cells after 2 days of 10 microM RA treatment and continued to be observed at all times measured up to 6 days. Smaller peaks of apoptotic cells with less than G1 DNA content were observed in pCR3-B23 as compared with pCR3 cells after 4-6 days of 10 microM RA treatment. As measured by expressions of differentiation markers and the functional assessment of the ability to reduce nitroblue-tetrazolium, our results further showed that over-expression of nucleophosmin/B23 decreased the response of the cells to RA-induced differentiation. Less cleavage of PARP and in vitro caspase-3 activity were observed in PCR3-B23 cells as compared with pCR3 cells treated with 10 microM RA for 3-4 days. IRF-1 was induced after 6 hr of 10 microM RA treatment in the pCR3-B23 and pCR3 cells. Significantly more nucleophosmin/B23 was co-immunoprecipitated with IRF-1 from pCR3-B23 cells than from pCR3 cells during RA treatment (10 microM; 24 hr, 96 hr). The IRF-1 transcriptional activity was found to be attenuated in pCR3-B23 cells as compared with pCR3 cells during the treatment of cells with RA. Nucleophosmin/B23, through interacting with IRF-1, plays an important role in the control of the susceptibility of cells to RA-induced differentiation and apoptosis.

Enlarging effects of estradiol on the nuclear volume of neurons in the hypothalamus during aging

Neuronal nuclear volumes (NNVs) were measured in the medial preoptic nucleus (MPN), anterior hypothalamic area (AHA) and arcuate nucleus (ARN) of young adult, middle-aged, and old rats of both sexes. The NNVs in the darkly stained sexual-dimorphic nucleus of the preoptic area (SDN-POA) and the lighter staining surrounding area (non-SDN-POA) within the MPN were measured separately. Intact young and middle-aged female rats had larger NNVs than those of the males in SDN-POA, non-SDN-POA and AHA but not in ARN. During aging, only intact old female rats manifested significant NNV shrinkage in all the measured areas. Long-term treatment with estradiol benzoate (EB) caused a significant enlargement of the NNVs in non-SDN-POA and ARN of middle-aged and old male rats as well as the NNVs in SDN-POA, non-SDN-POA and ARN of old female rats. The enlarging effect of EB on NNVs in both SDN-POA and non-SDN-POA of female rats could be prevented by ovariectomy. Furthermore, NNVs in SDN-POA and non-SDN-POA of ovariectomized female rats were even smaller than those of the age-matched intact female rats. These results indicate that: (1) the NNVs of MPN and ARN in male and female rats were enlarged after long-term exposure of physiological dose of estradiol; (2) the enlarging effects of EB on NNV in MPN can explain why the NNV of intact female rats is larger than that of males, and (3) during aging, the sex-specific shrinkage of NNVs in MPN, AHA and ARN of female rats may be due to an intrinsic aging process rather than long-term effects of EB.

Middle cerebral artery Doppler velocimetric deceleration angle as a predictor of fetal anemia in Rh-alloimmunized fetuses without hydrops

OBJECTIVE

The purpose of this study was to evaluate the screening performance of a new middle cerebral artery Doppler velocimetric index for the prediction of fetal anemia.

STUDY DESIGN

Doppler velocimetry of the middle cerebral artery was performed before cordocentesis in 24 Rh-alloimmunized fetuses without hydrops on 52 occasions. The angle between the line describing the average slope during the diastolic phase of the cardiac cycle and the vertical, the middle cerebral artery standardized deceleration angle, was measured. The deceleration angle values were expressed in multiples of the median for gestational age. The screening performances of deceleration angle for the prediction of anemia (difference between expected mean hemoglobin level and measured value >/=2 g/dL) and severe anemia (hemoglobin deficit >/=5 g/dL) were determined.

RESULTS

The mean (+/-SD) gestational age at cordocentesis was 28.6 +/- 5.7 weeks' gestation. The risk of fetal anemia increased with decreasing deceleration angle values. The sensitivity and false-positive rate for the detection of anemia in cases with no previous transfusions (one measurement per patient) were 72.0% and 13.3%, respectively; among those with one previous transfusion the values were 90.0% and 0.0%, respectively. For severe anemia the corresponding values were 100% and 0%, respectively, among those with no previous transfusions and 100.0% and 16.7%, respectively, among those with one previous transfusion. There was no risk of severe anemia when the angle was >0.9 multiples of the median. The risk of anemia was significantly reduced with an angle greater than the median for gestational age (deceleration angle >1.0 multiples of the median; relative risk, 0.09; 95% confidence interval, 0.02-0.37). The risk was significantly increased with an angle less than the median for gestational age (deceleration angle <1.0 multiples of the median; relative risk, 30.0; 95% confidence interval, 5.9-158.4).

CONCLUSION

The risk of fetal hydrops is remote in the absence of severe anemia. With a new Doppler velocimetric index in the middle cerebral artery the risk of severe anemia was found to be low when the deceleration angle was >0.9 multiples of the median. Anemia can also be predicted with this index. The high sensitivities and acceptable false-positive rates support the potential clinical applicability of the method to reduce the reliance on cordocentesis in Rh alloimmunization. Our findings appear to validate the utility of the deceleration angle for the prediction of fetal anemia.

Effects of low-energy CO2 laser irradiation and the organic matrix on inhibition of enamel demineralization

In the past two decades, accumulated evidence has clearly demonstrated the inhibitory effects of laser irradiation on enamel demineralization, but the exact mechanisms of these effects remain unclear. The purpose of this study was to investigate the effects of low-energy CO2 laser irradiation on demineralization of both normal human enamel and human enamel with its organic matrix removed. Twenty-four human molars were collected, cleaned, and cut into two halves. One half of each tooth was randomly selected and its lipid and protein content extracted. The other half of each tooth was used as the matched control. Each tooth half had two window areas. All the left windows were treated with a low-energy laser irradiation, whereas the right windows served as the non-laser controls. After caries-like lesion formation in a pH-cycling environment, microradiographs of tooth sections were taken for quantification of demineralization. The mean mineral losses (with standard deviation) of the enamel control, the lased enamel, the non-organic enamel control, and the lased non-organic enamel subgroups were 3955 (1191), 52(49), 4565(1311), and 1191 (940), respectively. A factorial ANOVA showed significant effects of laser irradiation (p = 0.0001), organic matrix (p = 0.0125), and the laser-organic matrix interaction (p = 0.0377). The laser irradiation resulted in a greater than 98% reduction in mineral loss, but the laser effect dropped to about 70% when the organic matrix in the enamel was removed. The results suggest that clinically applicable CO2 laser irradiation may cause an almost complete inhibition of enamel demineralization.

Forming electrical networks in three dimensions by self-assembly

Self-assembly of millimeter-scale polyhedra, with surfaces patterned with solder dots, wires, and light-emitting diodes, generated electrically functional, three-dimensional networks. The patterns of dots and wires controlled the structure of the networks formed; both parallel and serial connections were generated.

Diabetes, hemoglobin A(1c), cholesterol, and the risk of moderate chronic renal insufficiency in an ambulatory population

Moderate chronic renal insufficiency is common, with 12.5 million individuals in the United States estimated to have a creatinine clearance less than 50 mL/min/1.73 m(2). Little is known about the risk factors for moderate chronic renal insufficiency. We studied 1, 428 subjects with Cockcroft-Gault-estimated creatinine clearances greater than 70 mL/min in a hospital-based ambulatory population. Over a mean of 5.7 +/- 1.3 years, 86 subjects developed moderate chronic renal insufficiency, defined as a decrease in creatinine clearance to less than 60 mL/min (1.1 case/100 person-years). Risk factors for moderate chronic renal insufficiency were identified using a proportional hazards model controlling for age, sex, race, systolic blood pressure, and angiotensin-converting enzyme (ACE) inhibitor use. The risk for developing moderate chronic renal insufficiency was associated with diabetes mellitus (relative risk, 2.1; 95% confidence interval [CI], 1.3 to 3.3) and elevated hemoglobin A(1c) levels. Compared with subjects with normoglycemia (hemoglobin A(1c) </= 5.7%), the relative risk for moderate chronic renal insufficiency for patients in the upper quartile of hemoglobin A(1c) (>9.0%) was 2.7 (95% CI, 1.4 to 5.1). The development of moderate chronic renal insufficiency was also independently predicted by elevated maximum serum cholesterol level. Compared with subjects with maximum cholesterol levels of 250 mg/dL or less, the relative risk for those with maximum cholesterol levels greater than 350 mg/dL was 2.4 (95% CI, 1.1 to 5.2). Similar relative risks were obtained when moderate chronic renal insufficiency was defined by the development of an increase in serum creatinine level. Hypercholesterolemia was also associated with moderate chronic renal insufficiency among persons without diabetes. In conclusion, the risk for developing moderate chronic renal insufficiency is increased by diabetes and elevated hemoglobin A(1c) and serum cholesterol levels. Modification of these risk factors may decrease the incidence of moderate chronic renal insufficiency.

Chronic renal confusion: insufficiency, failure, dysfunction, or disease

The terms routinely used to describe states of reduced glomerular filtration rate (GFR) not requiring renal replacement therapy are poorly defined. With increasing interest in the epidemiology of chronic renal insufficiency and the timing of initiation of dialysis, terms such as "pre-ESRD" and "pre-dialysis" have been popularized, again without clear definition. Unambiguous terminology should be adopted. The authors favor using the term chronic renal insufficiency to describe states of reduced GFR not severe enough to require dialysis or transplantation. The authors propose classifying patients with GFR of 60 to 41 mL/min, 40 to 21 mL/min, and 20 mL/min or below as having mild, moderate, and advanced degrees of chronic renal insufficiency, respectively. The use of this terminology will facilitate communication among nephrologists and other physicians and provide a framework for comparison of populations across cohort studies and clinical trials.

White matter injury in spinal cord ischemia: protection by AMPA/kainate glutamate receptor antagonism

BACKGROUND AND PURPOSE

Spinal cord ischemia is a serious complication of surgery of the aorta. NMDA receptor activation secondary to ischemia-induced release of glutamate is a major mechanism of neuronal death in gray matter. White matter injury after ischemia results in long-tract dysfunction and disability. The AMPA/kainate receptor mechanism has recently been implicated in white matter injury.

METHODS

We studied the effects of AMPA/kainate receptor blockade on ischemic white matter injury in a rat model of spinal cord ischemia.

RESULTS

Intrathecal administration of an AMPA/kainate antagonist, 6-nitro-7-sulfamoyl-(f)-quinoxaline-2, 3-dione (NBQX), 1 hour before ischemia reduced locomotor deficit, based on the Basso-Beattie-Bresnahan scale (0=total paralysis; 21=normal) (sham: 21+/-0, n=3; saline: 3.7+/-4.5, n=7; NBQX: 12. 7+/-7.0, n=7, P<0.05) 6 weeks after ischemia. Gray matter damage and neuronal loss in the ventral horn were evident after ischemia, but no difference was noted between the saline and NBQX groups. The extent of white matter injury was quantitatively assessed, based on axonal counts, and was significantly less in the NBQX as compared with the saline group in the ventral (sham: 1063+/-44/200x200 microm, n=3; saline: 556+/-104, n=7; NBQX: 883+/-103, n=7), ventrolateral (sham: 1060+/-135, n=3; saline: 411+/-66, n=7; NBQX: 676+/-122, n=7), and corticospinal tract (sham: 3391+/-219, n=3; saline: 318+/-23, n=7; NBQX: 588+/-103, n=7) in the white matter on day 42.

CONCLUSIONS

Results indicate severe white matter injury in the spinal cord after transient ischemia. NBQX, an AMPA/kainate receptor antagonist, reduced ischemia-induced white matter injury and improved locomotor function.

Chemotherapy alone versus surgery followed by chemotherapy for stage I/IIE large-cell lymphoma of the stomach

The optimal treatment of localized large-cell lymphoma of the stomach remains controversial. In particular, the role of surgical resection of the primary tumor needs to be clearly defined. We have reviewed all patients with a diagnosis of gastric lymphoma and treated in our institutions between 1988 and 1998. Patients fulfilling the following criteria were included in this study: (1) histologically proven large-cell lymphoma of the stomach; (2) adequate pathological materials and complete clinical information for analysis; (3) clinical stage I/II disease according to the Musshoff modification of Ann Arbor system; and (4) received primary chemotherapy alone with anthracycline- or anthracenedione-containing regimens (group A) or curative surgery followed by adjuvant chemotherapy (group B). There were 38 and 21 patients in group A and group B, respectively. All pertinent clinicopathologic features were similar between the two groups of patients, except that patients of group A had significantly more stage II-2 disease (P = 0.004). Of group A, among 36 patients who could be evaluated for response to chemotherapy, there were 29 complete and 1 partial responses, with an overall response rate of 83.3% (95% CI, 71.1-95.5%). The projected 5-year relapse-free survival (RFS) and overall survival (OS) were 86.0% (95% CI, 73.3-98.7%) and 72.6% (95% CI, 57.0-88.2%), respectively. On the other hand, the projected 5-year RFS and OS of group B were 77.9% (95% CI, 58.0-97.8%) and 77.8% (95% CI, 57.9-97. 7%), respectively, not significantly different from that of group A. Our data suggest that systemic chemotherapy alone may be a reasonable alternative treatment for stage I/II large-cell lymphoma of the stomach. Resection of the primary tumor before systemic chemotherapy does not appear to improve the cure rate of this group of patients.

Chemotherapy alone versus surgery followed by chemotherapy for stage I/IIE large-cell lymphoma of the stomach

The optimal treatment of localized large-cell lymphoma of the stomach remains controversial. In particular, the role of surgical resection of the primary tumor needs to be clearly defined. We have reviewed all patients with a diagnosis of gastric lymphoma and treated in our institutions between 1988 and 1998. Patients fulfilling the following criteria were included in this study: (1) histologically proven large-cell lymphoma of the stomach; (2) adequate pathological materials and complete clinical information for analysis; (3) clinical stage I/II disease according to the Musshoff modification of Ann Arbor system; and (4) received primary chemotherapy alone with anthracycline- or anthracenedione-containing regimens (group A) or curative surgery followed by adjuvant chemotherapy (group B). There were 38 and 21 patients in group A and group B, respectively. All pertinent clinicopathologic features were similar between the two groups of patients, except that patients of group A had significantly more stage II-2 disease (P = 0.004). Of group A, among 36 patients who could be evaluated for response to chemotherapy, there were 29 complete and 1 partial responses, with an overall response rate of 83.3% (95% CI, 71.1-95.5%). The projected 5-year relapse-free survival (RFS) and overall survival (OS) were 86.0% (95% CI, 73.3-98.7%) and 72.6% (95% CI, 57.0-88.2%), respectively. On the other hand, the projected 5-year RFS and OS of group B were 77.9% (95% CI, 58.0-97.8%) and 77.8% (95% CI, 57.9-97. 7%), respectively, not significantly different from that of group A. Our data suggest that systemic chemotherapy alone may be a reasonable alternative treatment for stage I/II large-cell lymphoma of the stomach. Resection of the primary tumor before systemic chemotherapy does not appear to improve the cure rate of this group of patients.

Effects of fluid management on edema volume and midline shift in a rat model of ischemic stroke

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the effects of fluid management on brain water content (BW) and midline shift (MLS) after a focal cerebral ischemic insult.

METHODS

A suture model was used to induce focal cerebral ischemia for 90 minutes (n=44). The rats were randomly assigned to 3 groups 2. 5 hours after reperfusion: dehydration (n=24), control (n=8), or hydration (n=12). BW was obtained with the wet-dry weight method 24 hours after middle cerebral artery (MCA) occlusion. In addition, MRI were obtained (n=31) 24 hours after the onset of ischemia so that the ratio of hemispheric volumes ipsilateral (IH) and contralateral (CH) to the infarct and the extent of MLS could be obtained.

RESULTS

Across the range from moderate dehydration to intravascular volume expansion with isotonic saline, BW of the IH increased linearly as a function of change in body weight (r(2)=0.89), whereas few changes in relation to body weight were observed in CH, indicating a preferential effect of fluid management on the infarcted hemisphere. Furthermore, the hemispheric volume ratio (IH/CH) and MLS also increased in relation to changes in body weight. However, paradoxical increases in BW, IH/CH, and extent of MLS were observed in comparison with controls when severe dehydration was produced with high-dose mannitol.

CONCLUSIONS

Changes in ischemic BW by fluid management correlated closely with changes in body weight except when high-dose mannitol was used. Mannitol, as a dehydrating agent, may be associated with bimodal effects, with a high dose aggravating ischemic BW.

Attenuation of sepsis-induced apoptosis by heat shock pretreatment in rats

Apoptosis is a process by which cells undergo a form of non-necrotic cellular suicide. Although it is a programmed process, apoptosis can be induced by various stressors. During sepsis, apoptosis has been regarded as an important cause of cell death in the immune system, leading to unresponsiveness to treatment. This study was designed to investigate how prior heat shock induction can influence the rate of apoptosis in animals that have experienced sepsis. Sprague-Dawley rats were used, and experimental sepsis was induced by cecal ligation and puncture (CLP). Animals in the heated group were anesthetized and received heat shock by whole-body hyperthermia. They were sacrificed 9 h and 18 h after CLP as early and late sepsis, respectively. Apoptosis was evaluated by "DNA ladder" detection in agarose electrophoresis and Tdt-mediated dUTP nick end-labeling (TUNEL) assay. Hsp72 was detected by Western blot analysis. The results showed that the DNA ladder was detected most clearly in the thymus at the late phase of sepsis with time course dependence, while it showed less clearly in heat shock treated animals. Histopathological study by TUNEL assay obtained similar results in the thymus, where the cortex was more susceptible to apoptosis than the medulla. The Western blot analysis showed that the heat shock induced Hsp72 concomitant with an increase in Bcl-2:Bax ratio. In conclusion, heat shock pretreatment prevents rats from sepsis-induced apoptosis that may account for the better outcome of experimental sepsis. An increase in the Bcl-2:Bax ratio may in part explain the molecular mechanism of the effect of heat shock pretreatment.

Oxygen-glucose deprivation induces inducible nitric oxide synthase and nitrotyrosine expression in cerebral endothelial cells

BACKGROUND AND PURPOSE

The cerebral endothelial cells (ECs) are a primary target of hypoxic or ischemic brain insults. EC damage may contribute to postischemic secondary injury. Massive production of NO after inducible NO synthase (iNOS) expression has been implicated in cell death. This study aimed to characterize bovine cerebral EC death in relation to iNOS expression after oxygen-glucose deprivation (OGD) in vitro.

METHODS

OGD in bovine cerebral ECs in culture was induced by deleting glucose in the medium and by incubating the cells in a temperature-controlled anaerobic chamber. The extent of cell death was assessed by trypan blue exclusion, MTT assay, and LDH release. ELISA, gel electrophoresis, and staining by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling were used to examine DNA fragmentation. The expression of iNOS mRNA and protein was detected by reverse transcription-polymerase chain reaction and Western blotting, respectively. Nitrotyrosine expression was confirmed with Western blot analysis and immunostaining.

RESULTS

Bovine cerebral EC death was dependent on the duration of OGD and showed selected biochemical, morphological, and pharmacological features suggestive of apoptosis. OGD also induced the expression of iNOS mRNA and protein in bovine cerebral ECs. Increased expression of nitrotyrosine, the product formed by peroxynitrite reaction with proteins, was also detected after OGD. The involvement of iNOS in EC death was suggested by partial reduction of cell death by NO synthase inhibitors, including L-N(G)-(1-iminoethyl)ornithine and nitro-L-arginine, and an NO scavenger, the Fe(2+)-N-methyl-D-glucamine dithiocarbamate complex.

CONCLUSIONS

OGD-induced bovine cerebral EC death involves an apoptotic process. Induction of iNOS with subsequent peroxynitrite formation may contribute to bovine cerebral EC death caused by OGD.

Chemotherapy alone versus surgery followed by chemotherapy for stage I/IIE large-cell lymphoma of the stomach

The optimal treatment of localized large-cell lymphoma of the stomach remains controversial. In particular, the role of surgical resection of the primary tumor needs to be clearly defined. We have reviewed all patients with a diagnosis of gastric lymphoma and treated in our institutions between 1988 and 1998. Patients fulfilling the following criteria were included in this study: (1) histologically proven large-cell lymphoma of the stomach; (2) adequate pathological materials and complete clinical information for analysis; (3) clinical stage I/II disease according to the Musshoff modification of Ann Arbor system; and (4) received primary chemotherapy alone with anthracycline- or anthracenedione-containing regimens (group A) or curative surgery followed by adjuvant chemotherapy (group B). There were 38 and 21 patients in group A and group B, respectively. All pertinent clinicopathologic features were similar between the two groups of patients, except that patients of group A had significantly more stage II-2 disease (P = 0.004). Of group A, among 36 patients who could be evaluated for response to chemotherapy, there were 29 complete and 1 partial responses, with an overall response rate of 83.3% (95% CI, 71.1-95.5%). The projected 5-year relapse-free survival (RFS) and overall survival (OS) were 86.0% (95% CI, 73.3-98.7%) and 72.6% (95% CI, 57.0-88.2%), respectively. On the other hand, the projected 5-year RFS and OS of group B were 77.9% (95% CI, 58.0-97.8%) and 77.8% (95% CI, 57.9-97. 7%), respectively, not significantly different from that of group A. Our data suggest that systemic chemotherapy alone may be a reasonable alternative treatment for stage I/II large-cell lymphoma of the stomach. Resection of the primary tumor before systemic chemotherapy does not appear to improve the cure rate of this group of patients.

Excess disability during morning care in nursing home residents with dementia

Excess disability was examined in 17 nursing home residents with dementia by comparing their performance of morning care tasks under two activities of daily living (ADL) caregiving approaches-a dependence-supportive one under usual care and an independence-supportive one under functional rehabilitation. The results suggest that excess disability in severely cognitively impaired and functionally disabled residents can be reduced by increasing opportunities for independent activity, and substituting nondirective and directive verbal assists for physical assists. Further, the findings indicate that increased independence in ADL can be achieved without increasing disruptive behaviors and can foster appropriate requests for task-related help during caregiving. Functional rehabilitation, however, requires more time than usual care.

Intravenous ancrod for treatment of acute ischemic stroke: the STAT study: a randomized controlled trial. Stroke Treatment with Ancrod Trial

CONTEXT

Approved treatment options for acute ischemic stroke in the United States and Canada are limited at present to intravenous tissue-type plasminogen activator, but bleeding complications, including intracranial hemorrhage, are a recognized complication.

OBJECTIVE

To evaluate the efficacy and safety of the defibrinogenating agent ancrod in patients with acute ischemic stroke.

DESIGN

The Stroke Treatment with Ancrod Trial (STAT), a randomized, parallel-group, double-blind, placebo-controlled trial conducted between August 1993 and January 1998.

SETTING

Forty-eight centers, primarily community hospitals, in the United States and Canada.

PATIENTS

A total of 500 patients with an acute or progressing ischemic neurological deficit were enrolled and included in the intent-to-treat analysis.

INTERVENTIONS

Patients were randomly assigned to receive ancrod (n=248) or placebo (n =252) as a continuous 72-hour intravenous infusion beginning within 3 hours of stroke onset, followed by infusions lasting approximately 1 hour at 96 and 120 hours. The ancrod regimen was designed to decrease plasma fibrinogen levels to 1.18 to 2.03 micromol/L.

MAIN OUTCOME MEASURES

The primary efficacy end point was functional status, with favorable functional status defined as survival to day 90 with a Barthel Index of 95 or more or at least the prestroke value, compared by treatment group. Primary safety variables included symptomatic intracranial hemorrhage and mortality.

RESULTS

Favorable functional status was achieved by more patients in the ancrod group (42.2%) than in the placebo group (34.4%; P=.04) by the prespecified covariate-adjusted analysis. Mortality was not different between treatment groups (at 90 days, 25.4% for the ancrod group and 23% for the placebo group; P=.62), and the proportion of severely disabled patients was less in the ancrod group than in the placebo group (11.8% vs 19.8%; P=.01). The favorable functional status observed with ancrod vs placebo was consistent in all subgroups defined for age, stroke severity, sex, prestroke disability, and time to treatment (< or = 3 or > 3 hours after stroke onset). There was a trend toward more symptomatic intracranial hemorrhages in the ancrod group vs placebo (5.2% vs 2.0%; P=.06), as well as a significant increase in asymptomatic intracranial hemorrhages (19.0% vs 10.7%; P=.01).

CONCLUSION

In this study, ancrod had a favorable benefit-risk profile for patients with acute ischemic stroke.

Blockage of N-methyl-D-aspartate receptors decreases testosterone levels and enhances postnatal neuronal apoptosis in the preoptic area of male rats

Sexual dimorphism has been found in the preoptic area of the hypothalamus (POA), a major site of glutamate actions via N-methyl-D-aspartate (NMDA) receptors. The sexually dimorphic nucleus of the preoptic area (SDN-POA) of male rats exhibits about seven-fold greater nuclear volume than that of females. A naturally occurring neonatal neuronal apoptosis, that can be prevented by testosterone, may contribute to this sexual difference in SDN-POA nuclear volume. Since activation of NMDA receptors in the POA induces GnRH secretion, it may be involved in both elevation of serum testosterone and prevention of neuronal death in the SDN-POA. In the present study, protein expression of NMDA receptors in the POA of male and female fetuses was quantified on the day preceding the fetal testosterone peak (embryonic day 16; ED 16). Rats were then distributed in four groups: (1) untreated males, (2) untreated females, (3) males pretreated with MK-801 (a noncompetitive NMDA receptor antagonist), and (4) females pretreated with MK-801. Serum levels of testosterone were estimated on the afternoon of ED 18. Expression of Bcl-2 and Bax, as well as neuronal apoptosis in SDN-POA, were observed on postnatal day 8. The results showed that (1) expression of NMDA receptors in the POA of male fetuses was higher than that of females on ED 16; (2) levels of testosterone were lower in MK-801 pretreated male fetuses than in intact males on ED 18; (3) expression of Bcl-2 in the POA of MK-801 pretreated male rats was significantly less than that of control males; (4) the apoptotic incidence in the SDN-POA of MK-801 pretreated male rats was significantly greater than in control males, while there was no significant difference in apoptotic incidence in the SDN-POA between MK-801 pretreated and intact females. These results suggest that the NMDA receptor is highly expressed in prenatal male fetuses, and that it might play an important role in the elevation of testosterone levels. Moreover, activation of NMDA receptors may protect SDN-POA neurons from naturally occurring neuronal death, by modulating testosterone and/or Bcl-2 expression.

Atypical teratoid/rhabdoid tumor of the central nervous system: a comparative study with primitive neuroectodermal tumor/medulloblastoma

Eleven atypical teratoid/rhabdoid tumors (AT/RT) and 121 primitive neuroectodermal tumors/medulloblastomas (PNET/MB) were included in this study for evaluation of the histopathological features of AT/RT and comparison between AT/RT and PNET/MB. Histopathological studies of AT/RT showed that in addition to the commonly recognized components, i.e., rhabdoid cells, small (PNET/MB) cells, spindle cells and epithelial components, there was a previously unrecognized component, sickle-shaped embracing cells, which were present in all cases and could be useful as a histological marker of this tumor. Immunohistochemical studies showed divergent differentiation of the tumor cells and among the 16 antibodies studied, vimentin, neuron-specific enolase, epithelial membrane antigen and glial fibrillary acidic protein were most commonly reactive. The frequency of AT/RT expressed as a ratio of AT/RT to PNET/MB was 1:11 in general and increased to 1:3.8 among patients younger than 3 years old. The AT/RT patients were younger than those with PNET/MB and had a female predominance. The MIB-1 labeling index of AT/RT was significantly higher than that of PNET/MB (mean 63.9 vs 40.1), which correlated with a shorter survival in patients with AT/RT than those with PNET/MB (median survival time 15.4 months vs 156.4 months).

Maternal urine beta-core hCG fragment level and small for gestational age neonates

OBJECTIVE

To determine whether second-trimester urine beta-core fragments of hCG predict small for gestational age (SGA) neonates.

METHODS

Spot urine beta-core levels were measured in 733 nonhypertensive women with singleton pregnancies who presented for amniocentesis and had karyotypically normal fetuses. The beta-core level was standardized to urine creatinine and expressed as multiples of the median. The area under a receiver operating characteristics curve was used to determine the screening efficiency of the urine analyte for prediction of small for gestational age (SGA) births. In a subgroup of cases, serum markers (alpha-fetoprotein [AFP], hCG, and unconjugated estriol) were compared using stepwise regression analysis to urine beta-core fragment for SGA prediction.

RESULTS

There were 23 (3.0%) SGA neonates. The mean +/- standard deviation (SD) gestation at urine collection was 16.4 +/- 1.3 weeks and collection to delivery interval was 23.0 +/- 2.2 weeks. Mean beta-core (+/- SD) fragment levels were significantly higher in those who later had SGA infants compared with appropriately grown infants (2982.8 ng/mg creatinine versus 1447.4 ng/mg creatinine, P <.001). Stepwise logistic regression found that urine beta-core fragment and serum AFP were the only significant predictors of SGA, with statistically significant chi(2) values (P <.001 and P =.038, respectively). The urine analyte was significantly superior. Second-trimester urine beta-core fragment had a 78.3% sensitivity and 70% specificity for SGA prediction. Exclusion of preeclamptic cases resulted in a sensitivity of 84.2% and a specificity of 71.2%.

CONCLUSION

Second-trimester elevated maternal urine beta-core fragment of hCG predicted SGA infants, and was superior to other serum analytes in that prediction.

Hypertonic mannitol loading of NF-kappaB transcription factor decoys in human brain microvascular endothelial cells blocks upregulation of ICAM-1

BACKGROUND AND PURPOSE

An acute inflammatory response exacerbates tissue injury during acute ischemic stroke. The transcription factor nuclear factor (NF)-kappaB plays a key role in endothelial cell activation and the inflammatory response. Targeted genetic disruption of NF-kappaB activation in cerebral endothelial cells may be protective in stroke. We determined whether a NF-kappaB transcription factor decoy (TFD) could block intercellular adhesion molecule (ICAM)-1 upregulation, an indicator of endothelial cell activation.

METHODS

We modeled ischemia-reperfusion in vitro by exposing cultured human brain microvascular endothelial cells (HBMEC) to tumor necrosis factor (TNF)-alpha and conditions of hypoxia-reoxygenation (H/R). Mannitol was used to load phosphothiorated oligonucleotides containing 3 copies of the kappaB binding sequences (TFDs) into cultured HBMEC. An NF-kappaB TFD, a mutated NF-kappaB TFD, and a scrambled TFD were studied for their effect on ICAM-1 mRNA levels and surface ICAM-1 by ELISA.

RESULTS

Hyperosmolar loading with mannitol permitted rapid transfection of TFD into endothelial cell nuclei. The NF-kappaB TFD but not the mutated or scrambled TFD competed with a kappaB sequence for binding to nuclear extracts from HBMEC exposed to TNF-alpha. The NF-kappaB TFD blocked the TNF-alpha-induced and H/R-induced increase in ICAM-1 mRNA levels and the upregulation of surface ICAM-1.

CONCLUSIONS

Mannitol delivers phosphothiorated oligonucleotides into cultured HBMEC. An NF-kappaB decoy blocks both TNF-alpha-induced and H/R-induced ICAM-1 upregulation in HBMEC. Targeted genetic disruption of endothelial NF-kappaB activation may be of benefit in acute ischemic stroke.

Differential effect of cycloheximide on neuronal and glioma cells treated with chemotherapy and radiation

Dividing cells and non-dividing cells are distinct in their cell cycle kinetics, and react differently when facing cytotoxic stimuli. A protein synthesis inhibitor, cycloheximide (CHX), has recently been found to protect neuronal cells from oxidative stress. We investigated whether CHX exerts differential effects on dividing and non-dividing cells in the brain under cytotoxic stimuli. Mitotic C6 rat glioma cells and postmitotic neuronal cells were studied with a cytotoxic regimen combining gamma-irradiation (RT) and 1,3-bis,2-chloroethyl-1-nitrosourea (BCNU). Cells were exposed to BCNU (1 g/ml) for 15 h before gamma-irradiation and incubated with CHX (1 g/ml) from 30 min before and until 5 h after irradiation. Clonogenic assay was used to assess cytotoxic effects on C6 glioma cells. LDH assay was used for the viability of H19-7 postmitotic neuronal cells. A 2.27-3.75 fold enhancement of cytotoxicity was noticed with the addition of CHX to BCNU and 2-10 Gy of radiation. Our data demonstrated that CHX enhanced cytotoxicity of RT plus BCNU, while no additional toxicity was incurred to the postmitotic neuronal cells when CHX was added. We further studied whether the inhibition of DNA repair, assayed by single-cell DNA electrophoresis (comet assay), is a contributing factor for the enhanced cytotoxicity on C6 glioma cells. Interestingly, the initial DNA damage after RT plus BCNU was equivalent; whereas DNA repair was significantly less at 5 h after radiation in CHX-treated C6 glioma cells. Protecting non-dividing neuronal cells to avoid excessive functional deficit is an integral part of a successful brain tumor treatment regimen. Taking advantage of the differential effect of CHX on glioma and neuronal cells may improve tumor control without excessive neural toxicity.

Transient and permanent resolution of ischemic lesions on diffusion-weighted imaging after brief periods of focal ischemia in rats : correlation with histopathology

BACKGROUND AND PURPOSE

The early ischemic lesions demonstrated by diffusion-weighted imaging (DWI) are potentially reversible. The purposes of this study were to determine whether resolution of initial DWI lesions is transient or permanent after different brief periods of focal brain ischemia and to evaluate histological outcomes.

METHODS

Sixteen rats were subjected to 10 minutes (n=7) or 30 minutes (n=7) of temporary middle cerebral artery occlusion or sham operation (n=2). DWI, perfusion-weighted imaging (PWI), and T(2)-weighted imaging (T(2)WI) were performed during occlusion; immediately after reperfusion; and at 0.5, 1.0, 1.5, 12, 24, 48, and 72 hours after reperfusion. After the last MRI study, the brains were fixed, sectioned, stained with hematoxylin and eosin, and evaluated for neuronal necrosis.

RESULTS

No MRI or histological abnormalities were observed in the sham-operated rats. In both the 10-minute and 30-minute groups, the perfusion deficits and DWI hyperintensities that occurred during occlusion disappeared shortly after reperfusion. The DWI, PWI, and T(2)WI results remained normal thereafter in the 10-minute group, whereas secondary DWI hyperintensity and T(2)WI abnormalities developed at the 12-hour observation point in the 30-minute group. Histological examinations demonstrated neuronal necrosis in both groups, but the number of necrotic neurons was significantly higher in the 30-minute group (95+/-4%) than in the 10-minute group (17+/-10%, P<0.0001).

CONCLUSIONS

Transient or permanent resolution of initial DWI lesions depends on the duration of ischemia. Transient resolution of DWI lesions is associated with widespread neuronal necrosis; moreover, permanent resolution of DWI lesions does not necessarily indicate complete salvage of brain tissue from ischemic injury.