Association of body size and fat distribution with risk of breast cancer among Chinese women

Most previous studies addressing the association of body size, weight change and body fat distribution with the risk of breast cancer were conducted in Western societies with a high proportion of overweight people. It remains unclear whether the dose-response relation observed in earlier studies can be extended to women with "normal" weight based on prevailing Western standards. To address this issue, we analyzed data from a population-based case-control study of breast cancer recently completed among Chinese women in urban Shanghai. In-person interviews and anthropometric measurements were completed for 1,459 women newly diagnosed with breast cancer from 25 to 64 years of age and 1,556 controls frequency-matched to cases on age. Unconditional logistic regression was employed to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI) related to anthropometric variables and self-reported body weight. Currently measured weight, body mass index [BMI: weight (kg)/height(m)(2)] or height was each found to be positively related to risk of postmenopausal breast cancer in a dose-response manner, with ORs (95% CI) being 2.0 (1.4-3.0), 2.0 (1.2-3.2) or 1.7 (1.2-2.5), respectively, for the highest category of weight, BMI or height compared to the lowest category of these variables. These variables were unrelated to premenopausal breast cancer risk. Reported weight at ages >40 years and weight gain after age 20 were more predictive for postmenopausal breast cancer than weight at an earlier age. After adjustment for BMI, waist-to-hip ratio was related to an increased risk of premenopausal [OR = 1.7 (1.3-2.3) for the highest category compared to the lowest category] but not postmenopausal breast cancer. This study suggests that, even in a relatively thin Chinese population, weight gain and height are related to an increased risk of postmenopausal breast cancer, while central fat distribution was associated with premenopausal breast cancer. General weight control may be an effective measurement for breast cancer prevention.

Characteristics of spongiform leukoencephalopathy induced by heroin: MRI detection

OBJECTIVE

To elucidate the imaging characteristics of spongiform leukoencephalopathy induced by heroin and the diagnostic value of MRI examination.

METHODS

Eleven cases of heroin addiction were examined by MRI. The sequences included T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) and fast fluid-attenuated inversion recovery pulse sequence (Flair).

RESULTS

Bilateral symmetrical lesions were located in the white matter of the cerebrum and cerebellum, the internal capsule in all cases, and the callosum in 6 cases. Elliptical lesions in the mesencephalon were found in two cases. These lesions were shown as hypointense signals on T1WI and hyperintense signals on T2WI and Flair's imaging. Cerebellar white matter suffered more severely, but the dentate nuclei were not invaded.

CONCLUSION

Heroin-induced spongiform leukoencephalopathy has characteristic patterns in MRI, which are very specific to this form of the disease.

Impairment of non-specific immunity in patients under persistent vegetative state resulting from trauma

OBJECTIVE

To investigate the immune response in patients under persistent vegetative state (PVS) resulting from trauma.

METHODS

Peripheral blood monocytes were obtained from 12 PVS patients (Group PVS)and individuals in normal control group by density gradient centrifugation; the enzyme linked immunosorbent assay kit was then used to measure monocyte HLA-DR antigen expression on the surface of peripheral blood monocytes before and after monocyte activation with either IFN-gamma or LPS.

RESULTS

Compared with normal control group, the peripheral blood monocyte HLA-DR antigen expression in the Group PVC fell significantly in PV S patients (P<0.001); the level of HLA-DR antigen express ion on the monocyte surface rose notably after stimulation with either IFN-gamma or LPS (P<0.01). As for PVS patients, it was still difficult to restore to normal (P<0.05).

CONCLUSIONS

The level of HLA-DR antigen expression on the sur face of peripheral blood monocytes in PVS patients decreases obviously. Therefore, the function of non-specific immunity in PVS patients is suppressed.

Diversity and coverage of structural sublibraries selected using the SAGE and SCA algorithms

It is often impractical to synthesize and test all compounds in a large exhaustive chemical library. Herein, we discuss rational approaches to selecting representative subsets of virtual libraries that help direct experimental synthetic efforts for diverse library design. We compare the performance of two stochastic sampling algorithms, Simulating Annealing Guided Evaluation (SAGE; Zheng, W.; Cho, S. J.; Waller, C. L.; Tropsha, A. J. Chem. Inf. Comput. Sci. 1999, 39, 738-746.) and Stochastic Cluster Analysis (SCA; Reynolds, C. H.; Druker, R.; Pfahler, L. B. Lead Discovery Using Stochastic Cluster Analysis (SCA): A New Method for Clustering Structurally Similar Compounds J. Chem. Inf. Comput. Sci. 1998, 38, 305-312.) for their ability to select both diverse and representative subsets of the entire chemical library space. The SAGE and SCA algorithms were compared using u- and s-optimal metrics as an independent assessment of diversity and coverage. This comparison showed that both algorithms were capable of generating sublibraries in descriptor space that are diverse and give reasonable coverage (i.e. are representative) of the original full library. Tests were carried out using simulated two-dimensional data sets and a 27 000 compound proprietary structural library as represented by computed Molconn-Z descriptors. One of the key observations from this work is that the algorithmically simple SCA method is capable of selecting subsets that are comparable to the more computationally intensive SAGE method.

Characterization of calcium channel binding

Voltage-dependent calcium channels are expressed in a variety of tissues including heart, muscles and brain. Saturation binding of a radioligand to the calcium channel is commonly used to characterize the expression level of the channel protein. Compound competition binding assay is a conventional screening method to determine the affinity of unlabeled compounds for the channel protein. This unit provides detailed experimental methods for two types of radioligand binding assays using [³H]PN200-100 and [¹²⁵I](conotoxin MVIIA. Voltage-dependent calcium channels are expressed in a variety of tissues including heart, muscles and brain.

Population-based, case-control study of blood C-peptide level and breast cancer risk

Insulin resistance has been suggested to be associated with an increased risk of breast cancer. Insulin sensitivity can be measured using blood C-peptide, a marker of insulin secretion. It is thus conceivable that blood C-peptide levels may be associated with breast cancer risk. To evaluate this hypothesis, we analyzed data from a subset (143 case-control pairs matched by age and status of menopause) of women who participated in the Shanghai Breast Cancer Study, a population-based, case-control study conducted in Shanghai during 1996-1998. Fasting blood samples were collected from study subjects to measure C-peptide levels. For cancer patients, the samples were collected before any cancer therapy. Conditional logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals related to C-peptide levels. Breast cancer risk was increased with increasing levels of C-peptide (trend test, P = 0.01), with an odds ratio of 2.7 (95% confidence interval = 1.2-5.9) observed for the highest compared with the lowest tertile of C-peptide concentration after adjusting for body mass index and age at the first live birth. The risk was not altered after fully adjusting for other traditional risk factors for breast cancer. This positive association was observed in both pre and postmenopausal women and regardless of the levels of waist-to-hip ratio or body mass index. The results from this study were consistent with the insulin-resistance hypothesis for breast cancer and suggest that increased levels of C-peptide may contribute to the development of breast cancer.

Antioxidant activity and phenolic compounds in selected herbs

The antioxidant capacities (oxygen radical absorbance capacity, ORAC) and total phenolic contents in extracts of 27 culinary herbs and 12 medicinal herbs were determined. The ORAC values and total phenolic contents for the medicinal herbs ranged from 1.88 to 22.30 micromol of Trolox equivalents (TE)/g of fresh weight and 0.23 to 2.85 mg of gallic acid equivalents (GAE)/g of fresh weight, respectively. Origanum x majoricum, O. vulgare ssp. hirtum, and Poliomintha longiflora have higher ORAC and phenolic contents as compared to other culinary herbs. The ORAC values and total phenolic content for the culinary herbs ranged from 2.35 to 92.18 micromol of TE/g of fresh weight and 0.26 to 17.51 mg of GAE/g of fresh weight, respectively. These also were much higher than values found in the medicinal herbs. The medicinal herbs with the highest ORAC values were Catharanthus roseus, Thymus vulgaris, Hypericum perforatum, and Artemisia annua. A linear relationship existed between ORAC values and total phenolic contents of the medicinal herbs (R = 0.919) and culinary herbs (R = 0.986). High-performance liquid chromatography (HPLC) coupled with diode-array detection was used to identify and quantify the phenolic compounds in selected herbs. Among the identified phenolic compounds, rosmarinic acid was the predominant phenolic compound in Salvia officinalis, Thymus vulgaris, Origanum x majoricum, and P. longiflora, whereas quercetin-3-O-rhamnosyl-(1 --> 2)-rhamnosyl-(1 --> 6)-glucoside and kaempferol-3-O-rhamnosyl-(1 --> 2)-rhamnosyl-(1 --> 6)-glucoside were predominant phenolic compounds in Ginkgo biloba leaves.

Modulation of recombinant GABA receptor/channel subunits by domain-specific antibodies in Xenopus oocytes

To study interaction of specific antibodies with the GABA receptor/channel, antisera were raised against the extracellular domains of the GABAA receptor/channel beta2 subunit, gamma2 subunit and the GABAC receptor/channel rho1 subunit. The specificity of the antibodies was characterized by immunocytochemistry and by Western blotting of transfected FDC-P1 cells expressing recombinant GABA receptor/channel subunits. The effects of the antibodies on whole-cell currents in Xenopus laevis oocytes expressing homomeric recombinant GABA receptor/channel beta2, gamma2, and rho1 were studied using two-microelectrode voltage clamp. In the absence of GABA, anti-alpha2, anti-gamma2, and anti-rho1 antisera elicited whole-cell currents in oocytes expressing beta2, gamma2, and rho1 subunits, respectively. The effect of antibody on channel activation was concentration-dependent. The whole-cell currents induced by anti-beta2 and anti-gamma2 were several-fold greater than those induced by application of 100 microm GABA. In Xenopus oocytes expressing recombinant rho1 subunits, GABA-induced whole-cell currents were inhibited by the anti-rho1 antibody. In contrast, the GABA-induced whole-cell currents were potentiated several-fold by anti-beta2 and anti-gamma2 antibodies in Xenopus oocytes expressing homomeric beta2 and gamma2 subunits. Our studies indicate that antibodies specific to the N-terminal domain of GABA receptor/channel subunits can modulate the neurotransmitter receptor function.

Dietary folate intake and breast cancer risk: results from the Shanghai Breast Cancer Study

Folate is involved in DNA synthesis, repair, and methylation. It has been hypothesized that high intake of folate may reduce the risk of human cancers, including cancer of the breast. Using data from a population-based case-control study of breast cancer conducted in urban Shanghai during 1996-1998, we evaluated the association of dietary folate intake and breast cancer risk among 1321 cases and 1382 controls, 25-64 years of age, who never drank alcohol regularly or used vitamin supplements. Usual dietary habits were assessed with an in-person, interviewer-administered food frequency questionnaire developed and tested for use in this population. Unconditional logistic regression models were used to calculate odds ratios (ORs) and their 95% confidence intervals (95% CIs) after adjusting for potential confounding factors. Dietary folate intake was inversely associated with breast cancer risk (P for trend, 0.05) with an adjusted OR of 0.71 (95% CI, 0.56-0.92) observed among women who were in the highest quintile of intake. The inverse association was stronger after further adjusting for total fruit and vegetable and animal food intakes (OR, 0.62; 95% CI, 0.46-0.82; P for trend, 0.01). A more pronounced inverse association between folate intake and breast cancer risk (OR, 0.47; 95% CI, 0.25-0.88; P for trend, 0.01) was observed among women who consumed high levels of folate cofactors (methionine, vitamin B(12), and vitamin B(6)) than those whose intake levels of these nutrients were low. Dietary intake of methionine, vitamin B(12), and vitamin B(6) were not independently related to risk of breast cancer after adjusting for confounding factors. Thus, our study adds additional support to the protective role of dietary folate in breast carcinogenesis and suggests further that the effect of folate may be modified by dietary intake of methionine, vitamin B(12), and vitamin B(6).

Effect of plant growth temperature on antioxidant capacity in strawberry

The influence of four day/night growing temperature combinations (18/12, 25/12, 25/22, and 30/22 degrees C) on phenolic acid, flavonol, and anthocyanin content and their antioxidant activities against peroxyl radicals (ROO(*)), superoxide radicals (O(2)(*)(-)), hydrogen peroxide (H(2)O(2)), hydroxyl radicals (OH(*)), and singlet oxygen ((1)O(2)) in fruit juice of Earliglow and Kent strawberry (Fragaria x ananassa Duch.) cultivars was studied. Pelargonidin-based anthocyanins such as pelargonidin 3-glucoside (291.3-945.1 microg/g fresh wt.), pelargonidin 3-rutinoside (24.7-50.9 microg/g fresh wt.), and pelargonidin 3-glucoside-succinate (62.2-244.0 microg/g fresh wt.) were the predominant anthocyanins in strawberry fruit juice. The content of cyanidin-based anthocyanins, cyanidin 3-glucoside and cyanidin 3-glucoside-succinate, was much lower than that of pelargonidin-based anthocyanins. Strawberry growth in high temperature conditions significantly enhanced the content of p-coumaroylglucose, dihydroflavonol, quercetin 3-glucoside, quercetin 3-glucuronide, kaempferol 3-glucoside, kaempferol 3-glucuronide, cyanidin 3-glucoside, pelargonidin 3-glucoside, pelargonidin 3-rutinoside, cyanidin 3-glucoside-succinate, and pelargonidin 3-glucoside-succinate in strawberry juice. Plants grown in the cool day and cool night temperature (18/12 degrees C) generally had the lowest phenolic acid, flavonols, and anthocyanins. An increase in night temperature from 12 to 22 degrees C, with the day temperature kept constant at 25 degrees C, resulted in a significant increase in phenolic acid, flavonols, and anthocyanins. These conditions also resulted in a significant increase in antioxidant capacity. The highest day/night temperature (30/22 degrees C) yielded fruit with the most phenolic content as well as ROO(*), O(2)(*)(-), H(2)O(2), OH(*), and (1)O(2) radical absorbance capacity. Fruit of Kent cv. strawberry had higher values of phenolic acid, flavonols, anthocyanins, and antioxidant capacities than fruit of Earliglow cv. strawberry under all temperature regimes.

[Microsurgical treatment of 86 cases of intracranial aneurysms]

OBJECTIVE

To summarize the microsurgical experience in the treatment of intracranial aneurysms.

METHOD

The clinical materials, surgical modes and prognosis of 86 cases of clipped intracranial aneurysms were retrospectively reviewed.

RESULTS

Of the 86 cases, 69 recovered, 10 were moderately disabled, 2 severely disabled, and 5 died.

CONCLUSIONS

To avoid rerupture, aneurysms should be treated as soon as possible when the diagnosis was established. Proper management of rupture of aneurysms during operation is the key of success. Multiple aneurysms are better to be clipped in one stage. "de novo" aneurysms could be detected early by long-term angiography.

[The phase II clinical trial of Seratia Marcescens Anticancer Vaccine (S311) for malignant pleural effusions]

BACKGROUND

To evaluate the effect and adverse reactions of Seratia Marcescens Anticancer Vaccine ( S311) in the treatment of malignant pleural effusions.

METHODS

0. 32 mg of S311 was administered into intracavity once a week, for successive three weeks, after draining off the pleural cavity completely by thoracocentesis or chest drainage.

RESULTS

Two hundred and forty-one patients with malignant effusions finished the arrangement of S311 therapy. The overall response rate was 92. 1%. The main adverse reactions were fever and pleuritic pain. Some patients had chill, dyspnea, nausea and vomiting. Liver dysfunction was observed in a few cases.

CONCLUSIONS

S311 is an effective drug for malignant pleural effusions.

A malignant phenotype of hypertrophic cardiomyopathy caused by Arg719Gln cardiac beta-myosin heavy-chain mutation in a Chinese family

Mutations of the cardiac beta-myosin heavy-chain (beta-MHC) gene cause hypertrophic cardiomyopathy (HCM). Recent genotype-phenotype correlation studies have shown that mutations carry prognostic significance. We studied five unrelated Chinese families with hypertrophic cardiomyopathy. Exons 3-27 and 40 of the beta-MHC gene were screened with both the polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method and the cycle sequencing of the PCR products. A previously reported heterozygous mutation Arg719Gln (arginine-->glutamine in codon 719) in exon 19 was found in one family. The proband is a 30-year-old female diagnosed at age of 25 years when she presented with symptoms of chest pain, palpitations, and frequent incidents of dizziness and syncope. A two-dimensional echocardiogram showed moderate asymmetrical septal hypertrophy with left atrial enlargement. There was no obstruction of the left ventricular outflow tract (LVOT). The patient also developed atrial fibrillation. The proband's mother and one of her sisters had similar clinical manifestations and both died suddenly at the age of 38 years. In addition, two silent nucleotide substitutions (ACT63ACC, TTT244TTC) in the cardiac beta-MHC gene were identified in the other four families. These synonymous mutations did not cosegregate with the disease in the families and they were also present in the 60 healthy and age-matched control subjects. Of the five families studied, we did not find any missense mutation in the remaining four families. The missense mutation Arg719Gln found in the Chinese family is associated with a malignant phenotype of severe clinical symptoms and poor survival prognosis. This mutation also causes atrial enlargement and atrial fibrillation. Our study provides further evidence that the mutation, which alters the charge of the myosin heavy chain, is associated with a serious clinical outcome.

Resonance Rayleigh scattering study of the interaction of heparin with some basic diphenyl naphthylmethane dyes

In a near-neutral medium, a combination of heparin with some basic diphenyl naphthylmethane dyes such as victoria blue 4R (VB4R), victoria blue B (VBB), or night blue (NB) can result in a significant enhancement of resonance. Rayleigh scattering (RRS) and their maximum scattering wavelengths lambdamax appear at 523, 534, and 540 nm for VB4R, VBB, and NB, respectively. The characteristics of RRS spectra of the heparin-dye complexes, the influencing factors, and the optimum conditions of these reactions have been investigated. The RRS intensity is directly proportional to the concentration of heparin in the range of approximately 0 to 0.4 microg/mL for all systems. The methods exhibit high sensitivities, and the detection limits for heparin are 3.35 ng/mL for the VB4R system, 6.62 ng/ mL for the VBB system, and 6.29 ng/mL for the NB system. Because the VB4R system is the most sensitive, it was taken as an example to study the selectivity of the method. A new method for the determination of trace amounts of heparin based on RRS technique has been developed. Moreover, the enhancement reasons of RRS and the relationship between RRS spectral characteristics of the heparin-dye complex and its absorption spectra have been primarily discussed.

Resolving the structure of ionized helium in the intergalactic medium with the far ultraviolet spectroscopic explorer

The neutral hydrogen (H I) and ionized helium (He II) absorption in the spectra of quasars are unique probes of structure in the early universe. We present Far-Ultraviolet Spectroscopic Explorer observations of the line of sight to the quasar HE2347-4342 in the 1000 to 1187 angstrom band at a resolving power of 15,000. We resolve the He II Lyman alpha (Lyalpha) absorption as a discrete forest of absorption lines in the redshift range 2.3 to 2.7. About 50 percent of these features have H I counterparts with column densities N(H I) > 10(12.3) per square centimeter that account for most of the observed opacity in He II Lyalpha. The He II to H I column density ratio ranges from 1 to >1000, with an average of approximately 80. Ratios of <100 are consistent with photoionization of the absorbing gas by a hard ionizing spectrum resulting from the integrated light of quasars, but ratios of >100 in many locations indicate additional contributions from starburst galaxies or heavily filtered quasar radiation. The presence of He II Lyalpha absorbers with no H I counterparts indicates that structure is present even in low-density regions, consistent with theoretical predictions of structure formation through gravitational instability.

Population-based case-control study of soyfood intake and breast cancer risk in Shanghai

We evaluated the association of soyfood intake and breast cancer risk in a population-based case-control study among Chinese women in Shanghai. Included in the study were 1459 cases and 1556 age-matched controls, with respective response rates of 91.1% and 90.3%. Usual soyfood intake was assessed using a food frequency questionnaire (FFQ). Separate analyses were performed for all subjects and for the subset who reported no recent change in soyfood intake. The intake levels of soyfoods among women in Shanghai are high, with 96.6% women reporting soyfood consumption at least once a week. A statistically non-significant reduced risk (odds ratio (OR) = 0.78 95% CI = 0.52-1.16) of breast cancer was observed among those who reported eating soyfood at least once a week. Compared to those in the lowest decile intake group, women in the highest decile intake group had a 30% reduced risk of breast cancer (OR = 0.66, 95% CI = 0.46-0.95), but no monotonic dose-response relation was observed (P for trend, 0.28). Stratified analyses showed that the inverse association was restricted primarily among women who had a high body mass index (BMI), with an adjusted OR of 0.30 (95% CI = 0.10-0.94) observed for the highest intake group. The reduction in risk was stronger for breast cancer positive for both oestrogen receptor (ER) and progesterone receptor (PR) (OR = 0.44, 95% CI = 0.25-0.78) than those with other ER/PR status. More pronounced inverse associations were observed in analyses among those who reported no recent change in soyfood intake than those conducted in all subjects. A dose-response relation between soyfood intake and breast cancer risk was observed in this subset of women (P for trend, 0.02), with an OR of 0.46 (95%CI = 0.28-0.75) for those in the highest decile intake group. No clear monotonic dose-response relation was found between soyfood intake and breast cancer risk among regular soy eaters, but nevertheless the results suggest that regular soyfood consumption may reduce the risk of breast cancer, particularly for those positive for ER and PR; the effect may be modified by body mass index.

[Clinical characteristics and treatment of midline nasal and nasal type NK/T cell lymphoma]

OBJECTIVE

To study the clinical characteristics and treatment of midline nasal and nasal type T/Nk cell non-Hodgkin lymphoma.

METHODS

A retrospective study was made on the clinical characteristics, treatment, short-term effect, and two-year survival rate of 37 patients with midline nasal and nasal type T/NK non-Hodgkin lymphoma.

RESULTS

All of the patients were primarily treated with 2 cycles of CHOP chemotherapy. Ten of them were with good effect (common group). Then they were given 6 cycles of chemotherapy followed by focal radiotherapy and reached complete remission (CM). The other 27 patients failed to reach partial remission (PM) or even with their condition worsened after 2 cycles of CHOP regimen and were included into the refractory group. Fourteen of them received L-asparaginase-based salvage chemotherapy followed by focal radiotherapy (L-ASP group), and salvage therapy without L-ASP and followed by focal radiotherapy was given to the other 13 patients (non-L-ASP group). Continuous fever, angioinvasive growth and necrotic lesion could not be found among the patients in the common group. Their international prognostic indexes (IPI) were 0 approximately 1. Seventy percent of them were at the stages I or II. Continuous fever, angioinvasive growth and necrotic lesion could be found in the patients in refractory group. The IPIs among 85% of them were > 2, and 82% of them were at the stages III and IV. The CR rate was 46% for all patients as a whole, 100% for the common group, 26% for the refractory group (P < 0.005); and was 50% for the L-ASP group and 0% for the non-L-ASP group (P < 0.005). The 2-year survival rate was 43% for all patients as a whole, 100% for the common group, 20% for the refractory group (P < 0.005); and was 50.8% for the L-ASP group and 0% for the non-L-ASP group (P < 0.005).

CONCLUSION

Patients with midline nasal and nasal type T/NK non-Hodgkin lymphoma can be treated primarily by CHOP regimen and local radiotherapy. Refractory patients can be treated by salvage therapy based on L-ASP chemotherapy with a rather good effect. The clinical characteristics of most of the refractory patients include continuous fever, angioinvasive growth, necrotic lesion, being at stage III and IV, and with an IPI > 2.

[Effects of pesticide imidacloprid and its metabolites on soil respiration]

Soil respiration was measured using NaOH absorbing technique. Imidacloprid were applied to soil samples at concentration of 0, 10, 40, 100 micrograms.g-1, its hydrolysis and photolysis products were applied at 40 micrograms.g-1. The more significant effect at higher concentration of imidacloprid was observed. The effect of its hydrolysis product was minor than imidacloprid, but the photolysis products of 10 min have stronger effect, the effect decreased greatly in 30 min. Soil respiration recovered after 13 days. It showed that imidacloprid and its metabolites have little effect on soil microorganism.

Multiple growth factors regulate coronary embryonic vasculogenesis

Mechanisms regulating coronary vascularization are not well understood. To test hypotheses regarding the influence of key growth factors and their interactions, we studied vascular tube formation (vasculogenesis) in collagen gels onto which quail embryonic ventricles were placed and incubated in the presence of growth factors or inhibitors. Vasculogenesis in this model is dependent on tyrosine kinase receptors, since tube formation was totally blocked by genestein. Tube formation was attenuated when anti-bFGF or anti-VEGF neutralizing antibodies were added to the medium and nearly completely inhibited when the both were added. The attenuation associated with anti-VEGF was due primarily to a decrease in assembly of endothelial cells, while that associated with bFGF was primarily due to a reduction in endothelial cells. Soluble tie-2, the receptor for angiopoietins, also had an inhibitory effect and, when added with either anti-bFGF or anti-VEGF, markedly attenuated tube formation. At optimal doses, tube formation was enhanced 6.5-fold by bFGF and 2.5-fold by VEGF over the controls. Each of these growth factors was dependent upon the other for optimal induction of tube formation, since neutralizing antibodies to one markedly reduced the potency of the other. VEGF potency was also markedly reduced when soluble tie-2 was added to the medium. Tube formation was virtually totally blocked by exogenous TGF-beta at doses > 1 ng/ml, while neutralizing TGF-beta antibodies enhanced tube formation 2-fold in the 30 ng-30 microg range. These data provide the first documentation of multiple growth factor regulation of coronary tube formation.

Abortion history and breast cancer risk: results from the Shanghai Breast Cancer Study

Studies of the association between induced abortion and breast cancer risk have been inconsistent, perhaps due to underreporting of abortions. Induced abortion is a well-accepted family planning procedure in China, and women who have several induced abortions do not feel stigmatized. The authors used data from a population-based case-control study of breast cancer among women age 25-64 conducted between 1996 and 1998 in urban Shanghai to assess whether a history of and the number of induced abortions were related to breast cancer risk. In-person interviews were completed with 1,459 incident breast cancer cases ascertained through a population-based cancer registry, and 1,556 controls randomly selected from the general population in Shanghai (with respective response rates of 91% and 90%). After adjusting for confounding, there was no relation between ever having had an induced abortion and breast cancer (odds ratio [OR] = 0.9, 95% confidence interval [CI] 0.7-1.2). Women who had 3 or more induced abortions were not at increased risk of premenopausal breast cancer (OR = 0.9, 95% CI 0.6-1.4) or postmenopausal breast cancer (OR = 1.3, 95% CI 0.8-2.3). These results suggest that a history of several induced abortions has little influence on breast cancer risk in Chinese women.

Gabaergic inhibition antagonizes adaptive adjustment of the owl's auditory space map during the initial phase of plasticity

We studied the influence of GABA-mediated inhibition on adaptive adjustment of the owl's auditory space map during the initial phase of plasticity. Plasticity of the auditory space map was induced by subjecting owls to a chronic prismatic displacement of the visual field. In the initial stages of plasticity, inhibition suppressed responses to behaviorally appropriate, newly functional excitatory inputs. As a result, adaptive changes in excitatory input were only partially expressed as postsynaptic spike activity. This masking effect of inhibition on map plasticity did not depend on the activity of NMDA receptors at the synapses that supported the newly learned responses. On the basis of these results, we propose that the pattern of feedforward inhibition is less dynamic than the pattern of feedforward excitation at the site of plasticity. As a result, initially in the adjustment process the preexisting pattern of feedforward GABAergic inhibition opposes changes in the auditory space map and tends to preserve the established response properties of the network. The implications of this novel role of inhibition for the functional plasticity of the brain are discussed.