Obesity at diagnosis increases relapse rate and shortens time to relapse in breast cancer patients

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Objective: Breast cancer is the most common cancer in US women. One in eight women will develop breast cancer in their lifetime. Obesity, one of the 10 leading US health indicators, is associated with breast cancer risk and outcome in various studies. Louisiana is one of the three states with obesity prevalence above 30%. Feist-Weiller Cancer Center (FWCC) in Shreveport serves a large area of Louisiana as far as Baton Rouge. There is a large population of African American patients who are followed in FWCC. The objective of this study is to examine the association of obesity with breast cancer in our patient population. Study Design: A retrospective study from single institution. Medical records of the breast cancer patients in FWCC electronic data management system are reviewed. National Institutes of Health criteria are used to stratify patients: normal or underweight (NW, body mass index or BMI < 25kg/m2, overweight (OW, BMI 25–29.9), and obese (OB, BMI > = 30). Relapse and time to relapsed are compared among three groups. Result: In analysis using multivariant Cox proportional regression model, BMI at diagnosis is a statistical significant predictor of time to relapse. In univariant analysis, increased BMI at diagnosis is associated with 3.3% risk of disease relapse per year. The results demonstrates a positive association of obesity and disease course in breast cancer patients treated at FWCC.

No significant financial relationships to disclose.

Megestrol acetate increases the incidence of deep venous thrombosis in patients with non small cell lung cancer

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Background: To evaluate the incidence of deep venous thrombosis (DVT) in patients with non small cell lung cancer who take megestrol acetate as an appetite stimulant. Methods: A retrospective study of patients with non small cell lung cancer (NSCLC) was performed to determine the incidence of deep venous thrombosis. We reviewed medical records of patients with NSCLC who were treated with and without megestrol acetate as an appetite stimulant during the course of their treatment or follow up. Cochran-Mantel-Hansel statistics was performed. Results: We reviewed the charts of 179 patients with NSCLC. 86 patients received megestrol acetate during the course of treatment or follow up whereas 93 did not. Within the treatment group, 28 patients were female and 58 were male. In the control group 43 patients were female and 50 were male. There was no significant difference in the ECOG performance status of those in the treatment group from those in the control group. The frequency of DVT was 3.4 times higher in the treatment group as compared to the control group adjusting for gender (p < 0.02). Similarly, the frequency of DVT was 2.8 times higher in the treatment group as compared to the control group adjusting for stage (P < 0.045). Conclusions: After adjusting for gender or stage, the incidence of DVT appears to be higher for patients with NSCLC who took megestrol acetate as compared to those who did not. Even though megestrol acetate was being used as an appetite stimulant, the observed differences were not due to differences in the performance status of the two groups. Further prospective study of the risks and benefits of megestrol acetate as an appetite stimulant in patients with advanced NSCLC and other malignancies is warranted.

No significant financial relationships to disclose.

Structural basis of the multispecificity demonstrated by 17beta-hydroxysteroid dehydrogenase types 1 and 5

17Beta-hydroxysteroid dehydrogenases/ketosteroid reductases (17beta-HSDs/KSRs) catalyze the last step of sex steroid synthesis or the first step of their degradation, and are thus critical for many physiological processes. The multispecificity demonstrated by 17beta-HSDs is important for steroid metabolism in gonadal and peripheral tissues, and is a consequence of the architecture of their binding and catalytic sites. Structurally, most of the family members are short chain dehydrogenase-reductases (SDRs) except the type 5 enzyme, which is an aldo-keto reductase (AKR). 17Beta-HSD type 1, a representative of the SDR family, has been studied extensively since the 1950s. However, its structure was not determined until the 1990s. It has always been considered as estrogen specific, in accord with the narrow binding tunnel that has been structurally determined and has been found to be complementary to estrogens. A recent study revealed that, in spite of the enzyme's narrow binding tunnel, the pseudo-symmetry of C19 steroids leads to its alternative binding, resulting in the multispecificity of the enzyme. Expressed in ovary, breast and placenta, the enzyme catalyzes the formation of another estrogen A-diol from DHEA in addition to the biosynthesis of estradiol; it also inactivates the most active androgen DHT by both 17beta-hydroxysteroid oxidation and 3-ketosteroid reduction. Type 5 17beta-HSD (AKR1C3) differs significantly from the type 1 enzyme by possessing a spacious and flexible steroid-binding site. This is estimated to be about 960 or 470 A3 in ternary complex with testosterone or 4-dione, respectively, whereas the binding site volume of 17beta-HSD1 is only about 340 A3. This characteristic of the 17beta-HSD5 binding site permits the docking of various steroids in different orientations, which encompasses a wider range of activities from 20alpha-, 17beta- and 3alpha-HSD/KSR to prostaglandin 11-ketoreductase. The in vitro activities of the enzyme are significantly lower than the type 1 enzyme. In the ternary complex with testosterone, the steroid C3-C17 position is quasi-reversed as compared to the complex with 4-dione. The multi-specificity contributes significantly to steroid metabolism in peripheral tissues, due to the high levels of 17beta-HSD5 mRNA in both breast and prostate tissues.

Osteopontin regulation by protein kinase B (Akt) in HepG2 cells

AIM

The mechanism responsible for osteopontin regulation is not understood in HepG2 cells. The aim of this study was to investigate the relationship between protein kinase B (Akt), a key gene in PI3K signal transduction pathway, and osteopontin expression.

METHODS

HepG2 cells were transfected with constitutively active Akt and dominant negative Akt using lipofectin. The Akt transfection was confirmed by Western blot analysis. Osteopontin expression was detected by both Northern blot and Western blot.

RESULTS

Overexpression of exogenous Akt was detected in HepG2 cells by Western blot, indicating that HepG2 cells were successfully transfected with the Akt genes. In serum-free condition, the expression of osteopontin was either low or undetectable in HepG2 cells transfected with vector only, however, the expression increased after transfection of cells with constitutively active Akt. Osteopontin expression decreased when HepG2 cells were transfected with dominant negative Akt.

CONCLUSION

Protein kinase B (Akt) gene regulated osteopontin expression in RNA level and protein level, suggesting that osteopontin synthesis can be blocked by inactivation of the Akt gene. This leads to a potential means of intervention for the inhibition of metastases in liver cancer.

Electrophysiological changes in isolated spinal cord white matter in response to oxygen deprivation

STUDY DESIGN

In vitro studies using isolated guinea pig spinal cord white matter.

OBJECTIVES

To determine whether lack of oxygen can cause irreversible impairment of electrical impulse conduction.

SETTING

Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, USA.

METHODS

The hypoxic injury was induced by reducing the oxygen tension of the perfused solution by 80%. Compound action potentials (CAPs) were monitored before, during, and after oxygen deprivation.

RESULTS

We have found that 60 min of hypoxia reduced the conduction to 30% of preinjury level and recovered to approximately 60% of the preinjury level upon reoxygenation. Larger axons appeared to be more vulnerable to oxygen deprivation. We noted a significant decrease and recovery of the depolarizing afterpotential (DAP). Likewise, there was a delay and recovery of absolute and relative refractory period. Concomitantly, the ability of axons to follow repetitive stimuli was suppressed following oxygen deprivation but recovered upon reoxygenation.

CONCLUSION

Following 60 min of oxygen deprivation and 30 min of reoxygenation, mammalian spinal cord white matter can partially recover electrical impulse conduction. However, within the same period, cords gained a complete recovery of other electrical properties, such as the depression of DAP, the delaying of refractory period, and the decreased ability to respond to repetitive stimuli. Compared to previous findings when both oxygen and glucose were deprived, we conclude that glucose plays a relatively minor role during the acute stage of oxygen deprivation in mammalian spinal cord white matter.

An Activated GOPS-poly-L-Lysine- Coated Glass Surface for the Immobilization of 60mer Oligonucleotides

To explore a method for enhancing the immobilization and hybridization efficiency of oligonucleotides on DNA microarrays, conventional protocols of poly‐L‐lysine coating were modified by means of surface chemistry, namely, the slides were prepared by the covalently coupling of poly‐L‐lysine to a glycidoxy‐modified glass surface. The modified slides were then used to print microarrays for the detection of the SARS coronavirus by means of 60mer oligonucleotide probes. The characteristics of the modified slides concerning immobilization efficiency, hybridization dynamics, and probe stripping cycles were determined. The improved surface exhibited high immobilization efficiency, a good quality uniformity, and satisfactory hybridization dynamics. The spotting concentration of 10 μmol/L can meet the requirements of detection; the spots were approximately 170 nm in diameter; the mean fluorescence intensity of the SARS spots were between 3.2 × 10⁴ and 5.0 × 10⁴ after hybridization. Furthermore, the microarrays prepared by this method demonstrated more resistance to consecutive probe stripping cycles. The activated GOPS‐PLL slide could undergo hybridization stripping cycles for at least three cycles, and the highest loss in fluorescence intensity was found to be only 11.9 % after the third hybridization. The modified slides using the above‐mentioned method were superior to those slides treated with conventional approaches, which theoretically agrees with the fact that modification by surface chemistry attaches the DNA covalently firmly to the slides. This protocol may have great promise in the future for application in large‐scale manufacture.

One of the key steps in oligonucleotide microarray fabrication is the immobilization of oligonucleotides on a modified glass slide surface. Conventional protocols of poly‐L‐lysine coating were modified by means of surface chemistry in a way similar to the immobilization of 60mer oligonucleotides by deposition technology. The slides prepared by covalently coupling of poly‐L‐lysine to a glycidoxy‐modified glass surface were used to print microarrays for the detection of the SARS coronavirus.

Early onset of inflammation and later involvement of TGF in Duchenne muscular dystrophy

OBJECTIVE

To identify stage-specific induction of molecular pathology pathways in Duchenne muscular dystrophy (DMD).

METHODS

We performed mRNA profiling using muscles from fetopsies, infants (aged 8 to 10 months), and symptomatic patients (aged 5 to 12 years) with DMD, and age- and sex-matched controls. We performed immunohistochemistry to determine changes at the protein level and protein localization.

RESULTS

Activated tissue dendritic cells, expression of toll-like receptor 7, and strong induction of nuclear factor-kappaB pathways occurred soon after birth in DMD muscle. Two muscle wasting pathways, atrogin-1 and myostatin, were not induced at any stage of the disease. Normal muscle showed accumulation of glycolytic and oxidative metabolism capacity with increased age, but this accumulation failed in DMD. The transforming growth factor (TGF)-beta pathway was strongly induced in symptomatic patients, with expression of TGFbeta type II receptor and apoptosis signal-regulating kinase 1 proteins on subsets of mature DMD myofibers.

CONCLUSIONS

Our data show stage-specific remodeling of human dystrophin-deficient muscle, with inflammatory pathways predominating in the presymptomatic stages and acute activation of TGFbeta and failure of metabolic pathways later in the disease.

Contribution of PET imaging to the initial staging and prognosis of patients with Hodgkin's disease

BACKGROUND

Positron emission tomographic (PET) scanning utilizing [18F]fluorodeoxyglucose (FDG) is a new method of tumor imaging based on the increased glucose metabolic activity of malignant tumors. In Hodgkin's disease (HD), PET has proven value for the evaluation of residual masses following treatment and for the early diagnosis of relapse. In the initial staging of HD, PET frequently shows a higher stage than conventional methods (upstaging by PET). In the present study, we evaluated the frequency of stage changes by PET in a multicenter setting and determined its prognostic relevance.

PATIENTS AND METHODS

A total of 73 patients with newly diagnosed HD were staged with both conventional methods and whole-body PET scanning. All histological types and stages were represented. The median time of follow-up after the initial diagnosis was 25 months (range 1 month to 5 years). The response to treatment was determined by standard clinical and diagnostic criteria. For the purpose of this analysis, data from a PET center associated with a university medical center and a PET center associated with a group oncology practice were combined.

RESULTS

A total of 21 patients (28.8%) were upstaged by PET compared with conventional methods. In two cases (2.7%), a lower stage was suggested by PET scanning. With one possible exception, the upstaging had no obvious clinical or biological correlate. Among 12 patients in stage I (A + B) by conventional methods, seven were upstaged by PET (58.3%), four to stage II, one to stage III and two to stage IV. Among 42 patients in stage II, eight were upstaged by PET (19.0%), six to stage III and two to stage IV. Among 12 patients in stage III, six (50%) were upstaged to stage IV by PET. If only early-stage patients and major changes are considered (stages IA-IIB to III or IV), among 49, 10 were upstaged to III or IV, whereas in 39 staging was unchanged following PET. In the former group, three relapsed or were refractory compared with none in the latter group (P<0.006). In advanced stage patients (IIIA or IIIB) a trend toward treatment failure was apparent in patients who were upstaged by PET.

CONCLUSIONS

PET scanning is an interesting new modality for the accurate staging of patients with HD and frequently shows a higher stage than conventional methods. PET should be performed at initial diagnosis and should be included in prospective studies of patients with HD. Upstaging by PET may represent a risk factor for a more advanced stage or a biologically more aggressive tumor. Patients with early-stage disease as identified by conventional methods have a significant risk of treatment failure if a more advanced stage is indicated by PET. At present, major stage changes suggested by PET imaging should be confirmed by an independent diagnostic method.

Protein crystal growth on board Shenzhou 3: a concerted effort improves crystal diffraction quality and facilitates structure determination

The crystallization of 16 proteins was carried out using 60 wells on board Shenzhou 3 in 2002. Although the mission was only 7 days, careful and concerted planning at all stages made it possible to obtain crystals of improved quality compared to their ground controls for some of the proteins. Significantly improved resolutions were obtained from diffracted crystals of 4 proteins. A complete data set from a space crystal of the PEP carboxykinase yielded significantly higher resolution (1.46A vs. 1.87A), I/sigma (22.4 vs. 15.5), and a lower average temperature factor (29.2A(2) vs. 42.9A(2)) than the best ground-based control crystal. The 3-D structure of the enzyme is well improved with significant ligand density. It has been postulated that the reduced convection and absence of macromolecule sedimentation under microgravity have advantages/benefits for protein crystal growth. Improvements in experimental design for protein crystal growth in microgravity are ongoing.

Acrolein inflicts axonal membrane disruption and conduction loss in isolated guinea-pig spinal cord

We have examined the effect of acrolein, an aldehyde product of lipid peroxidation, on axons in isolated guinea-pig spinal cord white matter. We found that 200 microM acrolein, but not 50 microM, induced a time-dependent loss of compound action potential conduction. Such conduction loss was irreversible within 1 h after acrolein perfusion. Parallel anatomical assessment indicates membrane integrity breakdown based on a horseradish peroxidase-exclusion assay. This is the first report to suggest that acrolein inflicts severe axonal damage. Since axonal damage within white matter plays a key role in the pathology of traumatic spinal cord injury, we suggest that acrolein may be a critical factor in mediating secondary functional loss.

The increase of reactive oxygen species and their inhibition in an isolated guinea pig spinal cord compression model

STUDY DESIGN

In vitro studies using isolated guinea pig spinal cord.

OBJECTIVES

To develop an alternative model using isolated guinea pig spinal cord, which can be used to screen antioxidants for in vivo SCI treatment.

SETTING

Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, USA.

METHODS

The compression injury was induced by a constant-displacement of 5-s compression of spinal cord using a modified forceps possessing a spacer. Reactive oxygen species (ROS) were evaluated using three distinct methods: fluorescence microscopy, lipid peroxidation assay, and flow cytometry.

RESULTS

The injury-mediated ROS increases are comparable with other in vivo studies and consistent with our previous observation using a similar injury model and measured with electrophysiological and anatomical technique. Further, ascorbic acid, hypothermia, or the combination of both significantly suppressed superoxide and lipid peroxidation. The combination treatment was the most effective when compared with ascorbic acid or hypothermia alone.

CONCLUSION

This in vitro model has the advantage of replicating some of the in vivo conditions while gaining the ability to control the experimental conditions. This in vitro model is suitable to study the mechanisms of ROS generation and degradation and can also be used to critically evaluate the effective suppressor of ROS in the contents of spinal cord traumatic injury.

Pathological changes of isolated spinal cord axons in response to mechanical stretch

White matter strips extracted from adult guinea-pig spinal cords were maintained in vitro and studied physiologically using a double sucrose gap technique and anatomically using a horseradish peroxidase assay. The amplitude of compound action potentials was monitored continuously before, during, and after elongation. Three types of conduction blocks resulting from stretch injury were identified: an immediate, spontaneously reversible component, which may result from a transient increase in membrane permeability and consequent disturbance of ionic distribution; a second component that was irreversible within 30-60 min of recording, perhaps resulting from profound axolemmal disruption; and a third component, which may be due to perturbation of the myelin sheath, that was reversible with application of 100 microM of the potassium channel blocker, 4-aminopyridine. The intensity of the conduction deficits correlated with the extent of initial stretch over a full range of severity. Stimulus-response data indicate that mechanical damage to axons in stretch was evenly distributed across the caliber spectrum. Morphological examinations revealed that a small portion of axons exhibited membrane damage at 2 min following stretch and appeared to be largely sealed at 30 min after injury. Further, in the entire length of the cord strip subjected to stretch, axons closer to the surface were found to be more likely to suffer membrane damage, which distinguished stretch injury from compression injury. In summary, we have developed an in vitro model of axonal stretch that provides the ability to monitor changes in the properties of central myelinated axons following stretch injury in the absence of pathological variables related to vascular damage. This initial investigation found no evidence of secondary deterioration of axons in the first 30 min after stretch in vitro, although there was evidence of both transient and lasting physiological and anatomical damage to axons and their myelin sheaths.

AIDS and sex education for young people in China

Although China has had a rich sexual culture for thousands of years, Chinese people are usually unwilling to openly discuss issues of sex. Some parents are quite ignorant of the change in their children's sexual attitude and behaviour. In China today, adolescents are becoming much more sexually liberated. Premarital sex and unplanned pregnancies among teenagers are increasing. Sexually transmitted diseases (STD) including HIV/AIDS are also spreading rapidly. However, young people lack basic information on AIDS/STD and do not know how to protect themselves from these diseases or how to avoid unintended pregnancies. Several major youth peer education programmes in China are mentioned in this paper. Among them, a four-year programme entitled the Australian-Chinese AIDS/STD/Safer Sex Peer Education Programme for Youth, is discussed in some detail. The programme has so far reached over 40000 university and school students. Evaluation results show that the programme is effective in both significantly increasing students' knowledge about AIDS/STDs and changing their attitude towards AIDS patients. In addition, the programme is highly praised by the students.

[Experimental study of the effect of Hpudiod cream on random flap survival in rats]

OBJECTIVE

To explore the effect of Hpudiod cream on blood circulation of flap.

METHODS

80 rats were casually divided into two groups: the experiment and the control group. A random flap was created on the back of the animal. Flap survival and necrosis were observed in the two groups. The flaps were examined histologically and the capillaries were counted.

RESULTS

On the 5th and 7th day after operation, the distant ends of the flaps necrosed in both groups. On the 5th day there was no significant difference between the two groups in the number of the capillary in the middle of the flap (P > 0.05). On the 7th day, the capillary in the middle of the flap increased in the treatment group(P < 0.05).

CONCLUSION

Hpudiod cream can improve the blood circulation of the random flap evidently.

Polymorphic CA repeats in the IGF-I gene and breast cancer

Insulin-like growth factor (IGF)-I is a potent mitogen for breast cancer cells and may play a role in the disease. Although the involvement of IGF-I phenotype in breast cancer has been studied extensively, little is known about IGF-I genotype in relation to the disease. The IGF-I gene contains a polymorphic region composed of multiple cytosine-adenine dinucleotides (CA repeats). Studies of other genes indicate that the CA-repeat region in the promoter of a gene may affect transcription activity and that the length of the repeat is inversely correlated with transactivation. To examine if the IGF-I polymorphism is associated with breast cancer, we compared the length of CA repeats in the IGF-I gene between 53 breast cancer patients and 53 controls. Genomic DNA extracted from peripheral blood was used to determine the number of CA repeats through PCR amplification and DNA sequencing. Associations between CA repeats and breast cancer were assessed using unconditional logistic regression analysis. The results showed that the median number of CA repeats was 19, ranging from 15 to 23, and that compared to women without 19 CA repeats, women with 19 CA repeats were more likely to be breast cancer patients (OR = 2.87, 95%CI: 1.16-7.06) after adjusting for age, race, menopausal status, age at menopause, and alcohol use. The study also suggested possible synergistic interplay between IGF-I genotype and phenotype as women with 19 CA repeats and high plasma IGF-I had a much higher odds ratio for breast cancer (OR = 5.12, 95%CI: 1.42-18.5) than those with only one of the conditions. If our observations can be confirmed in larger studies, the findings will provide further evidence to support the role of IGF-I in breast cancer and the link between genetic polymorphism and cancer susceptibility.

On the ligands in charge-transfer complexes of porcine kidney flavoenzyme D-amino acid oxidase in three redox states: a resonance Raman study

To investigate the structural modulation of ligands and their interaction in the active-site nanospace when they form charge-transfer (CT) complexes with D-amino acid oxidase (DAO) in three redox states, we compared Raman bands of the ligands in complex with DAO with those of ligands free in solution. Isotope-labeled ligands were synthesized for assignments of observed bands. The COO(-) stretching of ligands observed around, 1,370 cm(-1) downshifted by about 17 cm(-1) upon complexation with oxidized, semiquinoid and reduced DAO, except for the case of reduced DAO-N-methylisonicotinate complex (8 cm(-1) downward shift); the interaction mode of the carboxylate group with the guanidino group of Arg283 and the hydroxy moiety of Tyr228 of DAO is similar in the three redox states. The C=N stretching mode (1,704 cm(-1)) of Delta(1)-piperideine-2-carboxylate (D1PC) downshifted to 1,675 and 1,681 cm(-1) upon complexation with reduced and semiquinoid DAO, respectively. The downward shifts indicate that the C=N bond is weakened upon the complexation. This is probably due mainly to charge-transfer (CT) interaction between D1PC and semiquinoid or reduced flavin, i.e., the partial electron donation from the highest occupied molecular orbital (HOMO) of reduced flavin or a singly occupied molecular orbital (SOMO) of semiquinoid flavin to the lowest unoccupied molecular orbital (LUMO), an antibonding orbital, of D1PC. This speculation was supported by the finding that the magnitude of the shift is smaller by 5 cm(-1) (observed at 1,680 cm(-1)) in the case of reduced DAO reconstituted with 7,8-Cl(2)-FAD, whose reduced form has lower electron-donating ability than natural reduced FAD. The amount of electron flow was estimated by applying the theory of Friedrich and Person [(1966) J. Chem. Phys. 44, 2166-2170] to these complexes; the amounts of charge transfer from reduced FAD and reduced 7,8-Cl(2)-FAD to D1PC were estimated to be about 10 and 8% of one electron, respectively, in the CT complexes of reduced DAO with D1PC.

Intravascular local gene transfer mediated by protein-coated metallic stent

OBJECTIVE

To assess the feasibility, efficiency and selectivity of adenovirus-mediated gene transfer to local arterial wall by protein-coated metallic stent.

METHODS

A replication-defective recombinant adenovirus carrying the Lac Z reporter gene for nuclear-specific beta-galactosidase (Ad-beta gal) was used in this study. The coating for metallic stent was made by immersing it in a gelatin solution containing crosslinker. The coated stents were mounted on a 4.0 or 3.0 mm percutaneous transluminal coronary angioplasty (PTCA) balloon and submersed into a high-titer Ad-beta gal viral stock (2 x 10(10) pfu/ml) for 3 min, and then implanted into the carotid arteries in 4 mini-swines and into the left anterior descending branch of the coronary artery in 2 mini-swines via 8F large lumen guiding catheters. The animals were sacrificed 7 (n = 4), 14 (n = 1) and 21 (n = 1) days after implantation, respectively. The beta-galactosidase expression was assessed by X-gal staining.

RESULTS

The results showed that the expression of transgene was detected in all animal. In 1 of carotid artery with an intact intima, the beta-gal expression was limited to endothelial cells. In vessels with denuded endothelium, gene expression was found in the sub-intima, media and adventitia. The transfection efficiency of medial smooth muscle cells was 38.6%. In 2 animals sacrificed 7 days after transfection, a microscopic examination of X-gal-stained samples did not show evidence of transfection in remote organs and arterial segments adjacent to the treated arterial site.

CONCLUSIONS

Adenovirus-mediated arterial gene transfer to endothelial, smooth muscle cells and adventitia by protein-coated metallic stent is feasible. The transfection efficiency is higher. The coated stent may act as a good carrier of adenovirus-mediated gene transfer and have a potential to prevent restenosis following PTCA.

COX-2 expression in dysplasia of the head and neck: correlation with elF4E

BACKGROUND

COX-2 inhibitors have shown promise in chemoprevention of epithelial tumors. eIF4E is a biomarker that has identified individuals at high risk for relapse after definitive treatment for head and neck squamous cell cancer (HNSCC). Hence, the authors wanted to determine if COX-2 is expressed in dysplasia of the head and neck and to study the correlation of expression of COX-2 with eIF4E as a potential surrogate endpoint for determining response to COX-2 inhibitors.

METHODS

The authors studied the expression of COX-2 and eIF4E in normal epithelium (n = 8), dysplasia (n = 51), mucosa adjacent to tumors (n = 11), and cancer of the head and neck (n = 19) using immunohistochemistry. In addition, Western blot analysis was performed on a subset of the above patient samples and HNSCC cell lines.

RESULTS

Immunohistochemical analysis showed expression of COX-2 and eIF4E in all cancers and no expression in normal tissues. In dysplastic epithelium, there was a significant correlation between the expression of eIF4E and COX-2 for all groups of dysplasia combined (chi-square = 40.3, P < 0.001). A Cochran-Armitage trend test showed a significant increase in the proportion of cases that expressed both molecular markers with increasing grades of dysplasia (P = 0.001). Western blot analysis showed increased expression of COX-2 and eIF4E in tumors compared with adjacent mucosa. All three HNSCC cell lines analyzed had increased expression of eIF4E, although only two had increased COX-2 expression.

CONCLUSIONS

Expression of COX-2 in dysplasia suggested that COX-2 inhibitors may play a role in chemoprevention of head and neck cancers and that the correlation of Cox-2 with eIF4E indicates that eIF4E can be a potential surrogate marker in chemoprevention trials.

Insulin-like growth factor-I and prostate cancer: a meta-analysis

Some, but not all, epidemiological found have shown that high circulating levels of insulin-like growth factor-I (IGF-I) are associated with an increased risk of prostate cancer. We performed a meta-analysis on all the studies reported so far to evaluate this association. In our Medline search, 14 case-control studies were identified. A standard protocol abstracted information for each study. Hedges' standardized mean difference (HSMD) and odds ratio (OR) were used to estimate the effect of IGF-I and IGF-binding proteins (IGFBP-3). The combined data showed that circulating levels of IGF-I were significantly higher in prostate cancer patients (HSMD = 0.194). The OR for prostate cancer was 1.47 (95% confidence interval (CI) 1.23-1.77) among men with high IGF-I compared to those with low IGF-I. The OR was 1.26 (95% CI 1.03-1.54) for IGFBP-3. Circulating levels of IGF-I and IGFBP-3 are likely to be higher in prostate cancer patients than in the controls. These findings support the suggestion that high IGF-I and IGFBP-3 are associated with an increased risk of prostate cancer.

The regulatory action of Radix Astragali on M-cholinergic receptor of the brain of senile rats

The changes in density of M-cholinergic receptors in different areas of senile rats and the regulatory action of Huang Qi ([symbol: see text] Radix Astragali, a drug for warming yang and replenishing qi) were observed by autoradiography. The results showed that the gray scale displayed in brain sections was clear and mainly distributed in the cortex, hippocampus and striate body, while that due to nonspecific combination was negligible. The gray scale in the cortex, hippocampus and striate body of the experimental group was markedly lower than that in the young control rats, decreased respectively by 24.87%, 14.12% and 12.76% (all P < 0.05); but it was obviously higher than those in the senile control rats, increased respectively by 24.15%, 14.38% and 13.47% (P < 0.05). The data indicate that Huang Qi ([symbol: see text]Radix Astragali) may up-regulate the decreased density of M-cholinergic receptors in the brain of senile rats.

Dimethylsulfoxide enhances CNS neuronal plasma membrane resealing after injury in low temperature or low calcium

The inability to repair the damaged membrane may be one of the key mechanisms underlying the severe neuronal degeneration and overall functional loss seen in in vivo spinal cord injury and traumatic axonal injury in blunt head trauma. Promoting membrane resealing following damage may therefore constitute a potential effective therapeutic intervention in treating head trauma and spinal cord injuries. In our previous studies, we have shown that the axolemma failed to reseal following transection in clinically related situations, such as low extracellular calcium and low temperature. Our current studies indicate that DMSO is capable of rendering significant improvement in guinea pig axonal membrane resealing following transection in both 0.5 mM [Ca(2+)](0) and 25 degrees C situations. This was demonstrated physiologically by monitoring membrane potential recovery and anatomically by conducting HRP-exclusion assays 60 minutes after injury. Further, we have shown that the addition of DMSO in normal Krebs' solution (2 mM [Ca(2+)](0) and 37 degrees C) resulted in a decrease in membrane repair following injury. This indicates that DMSO-mediated membrane repair is sensitive to temperature and calcium. This study suggests the role of DMSO in axonal membrane resealing in clinically relevant conditions and raises the possibility of using DMSO in combination with other more established therapies in spinal cord injury treatment.

Anatomical repair of nerve membranes in crushed mammalian spinal cord with polyethylene glycol

Acute damage to axons is manifested as a breach in their membranes, ion exchange across the compromised region, local depolarization, and sometimes conduction block. This condition can worsen leading to axotomy. Using a novel recording chamber, we demonstrate immediate arrest of this process by application of polyethylene glycol (PEG) to a severe compression of guinea pig spinal cord. Variable magnitudes of compound actions potentials (CAPs) were rapidly restored in 100% of the PEG-treated spinal cords. Using a dye exclusion test, in which horseradish peroxidase is imbibed by damaged axons, we have shown that the physiological recovery produced by polyethylene glycol was associated with sealing of compromised axolemmas. Injured axons readily imbibe horseradish peroxidase-but not following sealing of their membranes. The density of nerve fibers taking up the marker is significantly reduced following polyethylene glycol treatment compared to a control group. We further show that all axons-independent of their caliber-are equally susceptible to the compression injury and equally susceptible to polyethylene glycol mediated repair. Thus, polyethylene glycol-induced reversal of permeabilization by rapid membrane sealing is likely the basis for physiological recovery in crushed spinal cords. We discuss the clinical importance of these findings.

Clinical outcome of patients with previous myocardial infarction and left ventricular dysfunction assessed with myocardial (99m)Tc-MIBI SPECT and (18)F-FDG PET

Myocardial viability was assessed by (99m)Tc-methoxyisobutylisonitrile (MIBI) SPECT and (18)F-FDG PET to evaluate the prognosis and treatment strategy of patients with myocardial infarction (MI) and left ventricular (LV) dysfunction.

METHODS

One hundred twenty-three consecutive patients with previous MI and LV dysfunction (LV ejection fraction [EF], 35% +/- 6% [mean +/- SD]) who underwent (99m)Tc-MIBI SPECT and FDG PET were followed-up for 26 +/- 10 mo (mean +/- SD). Distributions of the 2 radiotracers in myocardial segments were classified into 2 patterns: myocardial perfusion-metabolism mismatch (MM) and match (M). LV EF and LV end-diastolic diameter (EDD) were measured by echocardiography at baseline, 3 mo (Pos1), and 6 mo (Pos2) after revascularization. Cardiac death, acute MI, unstable angina, and late revascularization (>3 mo) experienced by the patients during follow-up were defined as cardiac events.

RESULTS

Sixty-seven patients underwent revascularization and 56 patients were treated medically. Of the 72 patients with > or =2 MM segments, 42 underwent revascularization (group A1) and 30 were treated medically (group A2). Of the 51 patients with <2 MM segments, 25 underwent revascularization (group B1) and 26 were treated medically (group B2). The 4 groups had similar baseline characteristics and rest LV EF. After revascularization, EF (mean +/- SD) increased in group A1 from 36% +/- 5% to 44% +/- 8% (P < 0.0001) in Pos1 and to 51% +/- 9% (P < 0.0001) in Pos2. EDD (mean +/- SD) decreased from 62 +/- 8 mm to 56 +/- 5 mm (P < 0.001) in Pos1 and to 55 +/- 5 mm (P < 0.001) in Pos2. However, EF and EDD were unchanged in group B1 (P > 0.05). During the follow-up, 22 patients (17.9%) suffered from cardiac events, including 11 cardiac deaths, 4 acute MI, 6 late coronary artery bypass grafting, and 1 unstable angina pectoris. The cardiac event rate in group A2 (50%) was significantly higher than that of groups A1 (2.4%; chi(2) = 23.08; P < 0.0001), B1 (12%; chi(2) = 8.94; P = 0.003), and B2 (11.5%; chi(2) = 9.45; P = 0.002).

CONCLUSION

Assessment of myocardial viability using hybrid (99m)Tc-MIBI SPECT and FDG PET can predict the clinical outcome and is helpful to decision making in the treatment strategy of patients with MI and LV dysfunction. Revascularization can improve the LV function and clinical outcome of patients with >2 viable myocardial segments.

[Plasma cell granuloma of maxillary sinuses]

OBJECTIVE

To study the clinical features and treatment of plasma cell granuloma in maxillary sinuses.

METHOD

The clinical information of 3 cases was reported and the literatures were also reviewed.

RESULT

All of the 3 cases were cured after Caldwell-Luc operation combined with oral corticosteroids and antiallergic agent. Recurrence hasn't been found in half to 2 years follow-up period.

CONCLUSION

Plasma cell granuloma of maxillary sinus is a chronic inflammatory lesion with unknown origin. In almost all of the cases, CT images showed some degree of involvement of the bony wall of the maxillary sinuses. The imaging findings mimicker malignant tumors. But the prognosis were quite well in most of the patients.

Expression of the translation initiation factor eIF4E in the polyp-cancer sequence in the colon

The eukaryotic translation initiation factor 4E (eIF4E) has been shown to play a key role in cell growth, and several studies have documented an increased expression of eIF4E in a number of solid tumors, including breast, bladder, cervical, and head and neck cancers. This study was done to evaluate the potential role of eIF4E in the polyp-cancer sequence in the colorectum. Eighty-seven cases with lesions in the colorectum with a variety of histopathological diagnoses were randomly selected from the archives of the Pathology Department at Louisiana State University Health Sciences Center-Shreveport. Appropriate sections were selected for immunostaining with eIF4E. The medical records of the patients were reviewed, and demographic information was collected. All statistical analyses were performed using SAS software. A statistically significant relationship was found between the level of eIF4E expression and histological type of lesion: the lowest level of eIF4E expression was found in normal colon tissue, whereas the highest level of eIF4E expression was found in colorectal adenocarcinomas. Carcinomatous lesions were found to have a 43 times higher chance of having a high level of eIF4E expression compared with normal tissue (95% confidence interval, 8.0-213.6, P < 0.0001). In a multivariate analysis, histological type was the only variable that showed a significant relationship with eIF4E expression; no effect was found due to age, gender, race, history of polyps, and family history. The results from this study are consistent with other data from the literature and support the suggestion that eIF4E is strongly involved in colon tumorigenesis. eIF4E might be a useful intermediate biomarker for use in chemoprevention intervention studies in patients with colorectal polyps.

Crystallization and preliminary crystallographic data of fructose-1,6-bisphosphatase from human muscle

The enzyme human muscle fructose-1,6-bisphosphatase, which plays a critical role in gluconeogenesis, has been crystallized in the presence of 2-propanol, polyethylene glycol and magnesium chloride at pH 7.5. The space group was determined to be P4(2)2(1)2, with unit-cell parameters a = b = 73.57, c = 146.50 A, alpha = beta = lambda = 90 degrees and one subunit in the asymmetric unit. A 99.6% complete data set to 2.04 A has been collected at the National Synchrotron Light Source.

Cohort mortality study of North American industrial sand workers. III. Estimation of past and present exposures to respirable crystalline silica

BACKGROUND

Lung cancer and silicosis mortality were examined longitudinally and by a case-referent analysis in a cohort of workers selected from the North American industrial sand industry. Date of hire in the case-referent sub-cohort extended as far back as the second decade of the twentieth century.

OBJECTIVE

The aim of this study component was to develop estimates of average and cumulative exposure to respirable crystalline silica for the 342 selected cases and referents.

METHODS

Process and dust control histories were developed for each plant, and quantitative exposure data obtained from each of them and from a trade organization. An algorithm was developed to convert historical exposures reported in particle count concentrations to modern measures of mass concentration of respirable crystalline silica. Personal exposures were adjusted for use of protective equipment based on frequency of use and type of protection.

FINDINGS

Between 1974 and 1998, a total of 14249 exposure measurements had been taken using a cyclone and membrane filter and gave an overall geometric mean of 42 microg/m3. The only exposure data identified earlier were based on approximately 500 samples collected across the industry between 1947 and 1955 using the Greenburg-Smith impinger, with analysis by microscopy. These data were converted to modern measures using a factor of 1 mppcf = 276 microg/m3 respirable dust and then adjusting for percentage silica. In general, the highest exposures occurred in bagging and bulk-loading operations and the lowest in wet processing of sand.

CONCLUSIONS

There has been a substantial decline in exposure levels in this industry over time. The decline was rapid between the 1940s and 1970s and current exposures are, on average, less than 50 microg/m3. The use of personal protective equipment was judged to have had little impact on exposure before the 1970s.

Cohort mortality study of North American industrial sand workers. II. Case-referent analysis of lung cancer and silicosis deaths

BACKGROUND

A cohort mortality study of 2670 men in nine North American industrial sand plants resulted in 83 deaths from lung cancer 20 or more years after hire (standardized mortality ratio 139) and 37 deaths from silicosis (including seven from silico-tuberculosis). The lung cancer excess was unrelated to duration of employment and not found in all plants.

OBJECTIVES

The primary aim was to determine whether lung cancer risk among these employees was related to quantitative estimates of crystalline silica exposure, after allowance for cigarette smoking. A secondary aim was to do the same for silicosis mortality, partly as a means of validating the estimated levels of exposure.

METHODS

A nested case-referent study was undertaken with cases matched with up to two controls on plant, age and date of first employment from men who survived the case. Exposures were estimated by linking work histories to a job-exposure matrix, undertaken separately. Cigarette smoking information was obtained from medical records and other sources, blind as to case-control status. Matched statistical analyses were conducted using conditional logistic regression.

FINDINGS

Odds ratios for silicosis mortality were significantly related to cumulative silica exposures and tended to a relationship with category of average crystalline silica concentration, but inconsistently with length of employment. After accounting for a strong effect of cigarette smoking, odds ratios for lung cancer were related to cumulative crystalline silica exposure and to average silica concentration, but not to length of employment.

CONCLUSION

These findings support a causal relationship between lung cancer and quartz exposure after allowance for cigarette smoking, in the absence of cristobalite or other known occupational carcinogens.

Levels of insulin-like growth factor I (IGF-I) and IGF binding proteins 2 and 3 in serial postoperative serum samples and risk of prostate cancer recurrence

OBJECTIVES

To determine changes of insulin-like growth factor I (IGF-I), IGF binding protein-2 (IGFBP-2), and IGFBP-3 levels in serial postoperative serum samples from prostate cancer patients with and without relapse and to evaluate the prognostic value of these molecules in the recurrence of prostate cancer.

METHODS

From a group of patients with prostate cancer who had been followed for disease recurrence for almost 5 years after radical prostatectomy, we selected 38 patients (cases) who developed recurrent disease and 40 patients (controls) who were in remission. Of these patients, 70 had 4 and 8 had 3 serial postoperative serum samples collected. The median times for serum collection after surgery were 1.5 years for the first serial samples, 2.6 years for the second, 3.5 years for the third, and 4.5 years for the fourth. Serum levels of IGFBP-2, IGFBP-3, and IGF-I were measured, using commercial immunoassay kits.

RESULTS

The study showed lower serum levels of IGFBP-2 and IGFBP-3 in the cases than in controls(P <0.05) but no difference in IGF-I levels between the two groups (P = 0.277). In the sequential samples, IGFBP-2 levels increased over time in the controls (P = 0.014) but did not change in the cases (P = 0.528). There were no increasing or decreasing trends for IGF-I and IGFBP-3 in either case or control group(P >0.05).

CONCLUSIONS

The study suggests that IGFBP-2 may play a role in the progression of prostate cancer, but serum levels of IGFBP-2 as well as IGF-I and IGFBP-3 have no predictive values in the prognosis of prostate cancer.

Six-month-old infants' preference for lexical words

Previous work has shown that newborn infants categorically discriminate the fundamental syntactic category distinction between lexical and grammatical words. In this article, we show that by the age of 6 months, infants prefer to listen to lexical over grammatical words. In Experiment 1, infants were habituated to a list of either lexical or grammatical words, and then tested on new lists of words from the same and the contrasting categories. The infants showed recovery to lexical words after habituation to grammatical words but not vice versa. This asymmetry indicates a possible preference for lexical words. In Experiments 2 and 3, preference was assessed directly by presenting infants with alternating trials of lexical and grammatical words, in the central-fixation preference procedure. The infants looked significantly longer during lexical-word than grammatical-word trials. These results show that by 6 months, infants attend preferentially to lexical words. The implications of this emerging attentional preference for subsequent language acquisition are discussed.

[Effect of five kinds of vegetable seed oil on serum lipid and lipid peroxidation in rats]

The effects of vegetable seed oil on hyperlipidemia induced by high lipid diet in rats. Male adult Wistar rats were fed on the test diet containing 94% high lipid diet and 6% lard pinon seed oil, perilla seed oil, blackcurrent seed oil, borage seed oil and evening primrose seed oil respectively for 3 weeks. The results showed that the vale of trilyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol (LDL-C), LDL-C/HDL-C(high density lipoprotein cholesterol) ratio increased and the vale of HDL-C/TC ratio and lecithin-cholesterol acyltransferase(LCAT) activity decreased in the groups with vegetable seed oil were less than that of the control group. The results suggested that all the five kinds of vegetable seed oil had the effect of regulating lipid metabolism of hyperlipidemia rats to some extent. Pinon seed oil and borage seed oil may be well suited for the prevention of atherosclerosis.

Control of membrane sealing in injured mammalian spinal cord axons

The process of sealing of damaged axons was examined in isolated strips of white matter from guinea pig spinal cord by recording the "compound membrane potential," using a sucrose-gap technique, and by examining uptake of horseradish peroxidase (HRP). Following axonal transection, exponential recovery of membrane potential occurred with a time constant of 20 +/- 5 min, at 37 degrees C, and extracellular calcium activity ([Ca(2+)](o)) of 2 mM. Most axons excluded HRP by 30 min following transection. The rate of sealing was reduced by lowering calcium and was effectively blocked at [Ca(2+)](o) </= 0.5 mM, under which condition most axons continued to take up HRP for more than 1 h. Sealing at higher [Ca(2+)](o) was blocked by calpain inhibitors (calpeptin and calpain inhibitor-1) indicating a requirement for type II (mM) calpain in the sealing process. Following compression injury, the amplitude of the maximal compound action potential conducted through the injury site was reduced. The extent of amplitude reduction was increased when the tract was superfused with calcium-free Krebs' solution (Ca(2+) replaced by Mg(2+)). These results suggest that the fall in [Ca(2+)](o) seen following injury in vivo is sufficient to prevent membrane sealing and may paradoxically contribute to axonal dieback, retrograde cell death, and "secondary" axonal disruption.

Temperature dependence of membrane sealing following transection in mammalian spinal cord axons

Using an in vitro sucrose-gap recording chamber, sealing of cut axons in isolated strips of white matter from guinea pig spinal cord was measured by recording the "compound membrane potential". This functional sealing was found to correlate well with anatomical resealing, measured by a horseradish peroxidase uptake assay. Near-complete functional and anatomical recovery of the axonal membrane occurred routinely within 60 min following transection at 37 degrees C in regular Krebs' solution. The rate of membrane potential recovery is exponential, with a time-constant of 20+/-5 min. The sealing process at 31 degrees C was similar to that at 37 degrees C, and was effectively blocked at 25 degrees C, under which condition most axons continued to take up horseradish peroxidase for more than 1h, and failed to substantially recover their membrane potential. Seventy-five percent of the cords transected at 40 degrees C had similar sealing behavior to those at 37 degrees C and 31 degrees C. The balance failed to seal the cut end. Two-dimensional morphometric analysis has shown that raising the temperature from 25 degrees C to above 31 degrees C significantly decreases axonal permeabilization to horseradish peroxidase (increases the sealing of transected ends) across all areas of a transverse section of spinal cord. Moreover, this enhancement of sealing exists across all axon calibers. Since severe cooling compromises membrane resealing, caution needs to be taken when hypothermic treatment (below 25 degrees C) is applied within the first 60 min following mechanical injury. In summary, we have found that at normal temperature (37 degrees C), nerve fibers repair their damaged membrane following physical injury with an hour. This is similar at mildly lower (31 degrees C) and relatively higher (40 degrees C) temperature, although some fibers tend to collapse under this febrile temperature. Moreover, severely low temperature (25 degrees C) hindered the repair of damaged membranes. Based on our study, caution is needed in treating spinal cord injury with low temperatures.

Radionuclide techniques for evaluating dilated cardiomyopathy and ischemic cardiomyopathy

OBJECTIVE

To assess the clinical significance of radionuclide techniques in evaluating dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (CAD-CM).

METHODS

28 patients with DCM and 55 patients with CAD-CM were studied. All patients underwent 99mTc-MIBI myocardial perfusion SPECT and 18F-FDG myocardial metabolic PET. 78 patients had 99mTc-RBC radionuclide ventriculography and 68 patients had coronary angiography.

RESULTS

The results of 23 patients (82%) with DCM showed mild and non-segmental distribution perfusion abnormalities. 52 patients with CAD-CM (95%) showed perfusion abnormalities that distributed along the coronary vessel territories. Significant perfusion defects were found in 4 patients with DCM (14%) and 45 patients with CAD-CM (82%) (P < 0.01). The average perfusion score was 4.5 +/- 2.6 in DCM and 9.6 +/- 2.5 in CAD-CM and the area of diminished perfusion was significantly smaller in DCM than in CAD-CM (P < 0.001). Two patients with DCM and 18 patients with CAD-CM had metabolic defects. The patterns of perfusion/metabolic imaging showed mismatch in most patients with CAD-CM but match in most patients with DCM. The LVEF in patients with DCM and CAD-CM was both decreased but the decreases were not statistically different between DCM and CAD-CM. The RVEF in patients with DCM was significantly lower than that in patients with CAD-CM (32.4% +/- 13.9% vs 40.9% +/- 15.4%, P < 0.05).

CONCLUSION

The radionuclide techniques are helpful for distinguishing DCM from CAD-CM. The segmental perfusion abnormality and RVEF are the most important factors for differentiation of DCM from CAD-CM.

[The in vivo degradation, adsorption and excretion of poly(epsilon-caprolactone)]

The in vivo degradation of poly(epsilon-caprolactone(PCL) was studied in rats. The results showed that the PCL capsules with an initial molecualr weight of 66,000 stayed intact in vivo for 2 years, although the molecular weight of the capsules gradually declined during the two-year implantation. It then degraded into low molecular wight pieces with the extension of the implantation. Tritium-labeled low molecular weight PCL was subcutaneously implanted in rats to further investigate the absorption and excretion of the material. The radioactivity was first detected in blood 15 days post the implantation. At the same time radioactive excreta were recovered from feces and urine. An accumulative 92% of the implanted radioactive dosage was excreted from feces and urine 135 days post the implantation. In the meanwhile, the blood radioactivity dropped to the background level. Radioactivity in the organs was all close to the background level indicating that the material did not cumulate in body tissue and could be completely excreted.

The value of 99mTc-MIBI myocardial perfusion spect imaging in detecting coronary artery disease in patients with valvular disease before operation

OBJECTIVE

The aim of this study was to detect coronary artery disease using 99mTc-MIBI myocardial perfusion imaging in patients with valvular disease.

METHODS

Thirty patients with valvular disease confirmed by echocardiography underwent 99mTc-MIBI myocardial perfusion imaging using multiSPECT 1h after stress test (exercise, dipyridamole or dobutamine test) and were performed coronary angiography within 1 month before valvular operation.

RESULTS

For 29 out of the 30 patients, the results of 99mTc-MIBI myocardial perfusion imaging were similar with those of coronary angiography, the concordance rate was 96.7% and the negative predictability was 100%.

CONCLUSION

99Tc-MIBI myocardial perfusion imaging is a reliable non-invasive method for detecting coronary artery disease in patients with valvular disease and so as to draw up suitable operation programs for them.

Immediate recovery from spinal cord injury through molecular repair of nerve membranes with polyethylene glycol

A brief application of the hydrophilic polymer polyethylene glycol (PEG) swiftly repairs nerve membrane damage associated with severe spinal cord injury in adult guinea pigs. A 2 min application of PEG to a standardized compression injury to the cord immediately reversed the loss of nerve impulse conduction through the injury in all treated animals while nerve impulse conduction remained absent in all sham-treated guinea pigs. Physiological recovery was associated with a significant recovery of a quantifiable spinal cord dependent behavior in only PEG-treated animals. The application of PEG could be delayed for approximately 8 h without adversely affecting physiological and behavioral recovery which continued to improve for up to 1 month after PEG treatment.

Imaging vascular thrombosis with 99mTc-labeled fibrin alpha-chain peptide

An agent that permits scintigraphic detection of chronic deep venous thrombosis (DVT) or pulmonary embolism (PE) would be a welcome addition to the armamentarium of nuclear medicine. Because fibrin is the integral part of each clot, old or fresh, we hypothesized that a 99mTc-labeled fibrin alpha-chain N-terminal peptide, Gly-Pro-Arg-Pro-Pro, that binds to the C-terminal portion of the gamma-chain of fibrin can detect DVT and PE.

METHODS

The peptide was modified to Gly-Pro-Arg-Pro-Pro-Aba-Gly-Gly-(D)-Ala-Gly to permit efficient binding of 99mTc (99mTc-TP 850). The stability of the peptide was examined in vitro as well as in vivo. The ability of the agent to bind to rabbit, dog, and human fibrin and to inhibit adenosine diphosphate-induced platelet aggregation was examined. Blood clearance and 3-h tissue distribution were studied. DVT was induced in 8 rabbits using a stimulating electrode and in 2 rabbits by inserting a thrombin-soaked suture. PE was induced in 6 additional rabbits by introducing tantalum-impregnated blood clots into the right atrium, and the rabbits were radiographed to locate the emboli. 99mTc-TP 850 was then injected through a lateral ear vein, and each rabbit was imaged for up to 3 h. The rabbits were then killed, the heart and lungs were dissected and radiographed and the clots were harvested so that clot-to-blood radioactivity ratios could be determined.

RESULTS

The peptide analog permitted efficient incorporation of 99mTc, which was stable in vitro and in vivo. The blood clearance was biphasic, with an alpha phase half-life of approximately 4 min (20%) and a beta phase half-life of approximately 13 min (88%). The mean binding of 99mTc-TP 850 to human, dog, and rabbit fibrin was 46% +/- 2%, 60% +/- 3%, and 56% +/- 2.5%, respectively, and the inhibitory concentration of 50% for dog and rabbit platelet aggregation was 236 pm and 167 pm, respectively. All clots, including 24-h-old pulmonary emboli, were delineated. The radioactivity associated with clots varied from 0.01 to 0.09 %ID/g, with clot-to-blood radioactivity ratios ranging from 1.2 to 12.0. However, 48-h-old pulmonary emboli had lysed and were seen neither by radiography nor by scintigraphy.

CONCLUSION

A fibrin alpha-chain, N-terminal peptide that binds to the C-terminal portion of the gamma-chain of fibrin has been modified and labeled with 99mTc. The resultant peptide is stable in vitro and in vivo; binds to human, dog, and rabbit fibrin in large quantities; and inhibits platelet aggregation. The peptide clears rapidly from the blood and delineates experimental DVT and PE in rabbits. This agent is worthy of further investigation.

Newborn infants' sensitivity to perceptual cues to lexical and grammatical words

In our study newborn infants were presented with lists of lexical and grammatical words prepared from natural maternal speech. The results show that newborns are able to categorically discriminate these sets of words based on a constellation of perceptual cues that distinguish them. This general ability to detect and categorically discriminate sets of words on the basis of multiple acoustic and phonological cues may provide a perceptual base that can help older infants bootstrap into the acquisition of grammatical categories and syntactic structure.

Functional reconnection of severed mammalian spinal cord axons with polyethylene glycol

We describe a technique using the water-soluble polymer polyethylene glycol (PEG) to reconnect the two segments of completely transected mammalian spinal axons within minutes. This was accomplished by fusing completely severed strips of isolated guinea pig thoracic white matter maintained in vitro in a double sucrose gap recording chamber. The faces of the severed segments were pressed together, and PEG (MW 1,400-3,500 d; approximately 50% by weight in distilled water) was applied directly to this region through a micropipette and removed by aspiration within 2 min. Successful fusion was documented by the immediate restored conduction of compound action potentials through the original transection and by the variable numbers of fused axons in which anatomical continuity was shown to be restored by high-resolution light microscopy and by the diffusion of intracellular fluorescent dyes through fused axons. These data support the conclusion that some severed and subsequently PEG-fused spinal axons both demonstrate restored anatomical continuity and also are physiologically competent to conduct action potentials. This work adds to our previous demonstration that PEG application can immediately repair severely crushed, rather than cut, spinal cord white matter, and may lead to novel treatments for acute trauma to the central and peripheral nervous systems.

Evaluation of the clinical value of combination of 99mTc-MIBI myocardial SPECT and 18F-FDG PET in assessing myocardial viability

PURPOSE

To evaluate the value of 18F-FDG PET metabolic imaging and 99mTc-MIBI SPECT in the identification of myocardial viability in patients with previous myocardial infarction and left ventricular dysfunction.

METHODS

18F-FDG PET (made in China) and 99mTc-MIBI SPECT were performed in 60 patients (pts) (age 54+/-9 yr) with myocardial infarction before revascularization. Before and after revascularization, LVEF and wall motion were measured with echocardiography in 36 pts (Group A), and myocardial perfusion was evaluated in 24 pts (Group B).

RESULTS

According to the interpretation of perfusion and metabolic images, myocardial segments were classified into mismatch (MM): reduced myocardial perfusion and normal FDG uptake or match (M): reduced perfusion and FDG uptake. Out of 264 segments with hypoperfusion, 145 (54.9%) were MM, suggesting viable myocardium (G-A1 and G-B1), 119 (45.1%) were M, suggesting necrosis (G-A2 and G-B2). After revascularization, LVEF was increased in G-A1 (49+/-15% vs. 59+/-7%, p<0.05), and in G-B1 (50+/-8% vs. 59+/-12%, p<0.05), but was not improved in G-A2 and G-B2. LVEDD was decreased in G-A1 and G-B1 (p<0.05) and was unchanged in G-A2 and G-B2. The positive predictive value (PPV) of FDG PET for improvement of regional wall motion after revascularization was 88%, and the negative predictive value (NPV) was 72.6%. The PPV for improvement of perfusion was 84.1%, NPV was 85%, and accuracy was 84.4%.

CONCLUSION

18F-FDG imaging with Chinese PET has clinical value for assessing myocardial viability and identifying patients who will benefit from revascularization.

Acute repair of crushed guinea pig spinal cord by polyethylene glycol

Acute repair of crushed guinea pig spinal cord by polyethylene glycol. We have studied the responses of adult guinea pig spinal cord white matter to a standardized compression within a sucrose gap recording chamber. This injury eliminated compound action potential (CAP) conduction through the lesion, followed by little or no recovery of conduction by 1 h postinjury. We tested the ability of polyethylene glycol (PEG) to repair the injured axons and restore physiological function. Local application of PEG (1,800 MW, 50% by weight in water) for approximately 2 min restored CAP conduction through the injury as early as 1 min post PEG application. The recovery of the CAP </=1 h was significantly greater in treated compared with control spinal cords (controls = 3.6% of the preinjury amplitude; PEG treated = 19%; P < 0.0001, unpaired Student's t-test). Stimulus-response analysis indicated that the susceptibility for recovery was similar for all calibers of axons after PEG application. The enhanced recovery of conduction after PEG treatment was associated with an early alteration in conduction properties relative to control spinal cords. This included increased refractoriness and sensitivity to potassium channel blockade using 4-aminopyridine (4-AP). Normally 4-AP enhanced the amplitude of the recovering CAPs by approximately 40% in control spinal cords; however this effect was nearly doubled to approximately 72% in PEG treated spinal cords. Because severe clinical injuries to the spinal cord (and some peripheral nerves) are both resistant to medical treatment and usually produced by compression, we discuss the possible clinical benefits of PEG application.

[Research of experimental fistula stimuli vestibule evoked response]

OBJECTIVE

To investiqate a way of stimulation for experimental vestibul evoked response. The artificial fistula of right upper semicircular canal was made in 12 guineapig.

METHOD

Using a fistula stimuli probe device designed specially.

RESULT

We obtain a potential consisting of 3-4 positive waveforms. We called it the fistula stimuli vestibule evoked response (FsVeR). They had a coincide character. The response disappeared when the animal died. The cervical spinal section, orbital removal and facial nerve removal had little effects to FsVeR. When severe inner ear damage produced by Gentamycin injection, the potential disappeared. The potential disappeared but ABR were existed. When the upper semicircular canal and its nerve damage. The noise screen had a little affection to FsVeR.

CONCLUSION

These results indicated that FsVeR was mainly originated from the vestivbule system. The development of this recording technique provides a new method and maybe has important value for vestibule experimental research work.

Effects of electroacupuncture and twirling reinforcing-reducing manipulations on volume of microcirculatory blood flow in cerebral pia mater

Effects of electroacupuncture (EA) and routine acupuncture with twirling reinforcing and reducing manipulation of the needle (RA) both at Zusanli point (St 36) on volume of microcirculatory blood flow in the cerebral pia mater were observed by fenestration of the cranial bone and laser Doppler microcirculatory blood flow analyser. Results showed that both RA and EA could increase the volume of microcirculatory blood flow in the cerebral pia mater; and that the increase in the EA group was superior to that in RA group. This suggests that a moderate and effective stimulation is a key to the production of a regulative effect on the organism.