Fractionated stereotactic radiosurgery for 50 patients with recurrent or residual nasopharyngeal carcinoma

PURPOSE

This study was conducted to evaluate the clinical value of fractionated stereotactic radiosurgery (FSRS) as a boost treatment in 44 patients with residual or recurrent nasopharyngeal carcinoma after conventional radiotherapy (70-80 Gy) or a second course of radiotherapy (50 Gy) or as salvage treatment in 6 patients with recurrent nasopharyngeal carcinoma after a first or second course of radiotherapy at the primary site.

METHODS AND MATERIALS

From September 20, 1995 to December 30, 1998, 50 patients were treated with FSRS with 6 MV of photons. The total FSRS dose was 14-35 Gy (median dose 24) prescribed at 1-4 centers on the 60-90% isodose curves normalized to the isocenter by multiple fractions of 6-8, 12, or 15 Gy, with interfraction intervals of 4-6 days.

RESULTS

Thirty-eight patients (76%) had a complete tumor response, 9 (18%) had a partial response, and 3 (6%) were not assessable. The overall rate of survival was 83.6% at 1 year, 65.0% at 2 years, and 59.6% at 3 years. The overall disease-free survival rate among patients with residual tumor was 89.94% at 1 year, 73.97% at 2 years, and 73.97% at 3 years. Patients who were treated for recurrent lesions or who received FSRS as salvage therapy had a 46.53% rate of disease-free survival at both 1 and 2 years after therapy.

CONCLUSION

FSRS is strongly indicated for recurrent or residual nasopharyngeal carcinoma at the primary site.

[Clinical application of the reversed digital arteial island flap with digital wein and digital dorsal nerve anastomosis]

OBJECTIVE

To introduce clinical application of the reversed digital arteial island flap with digital wein and digital dorsal nerve anastomosis to repair digital soft tissue defect.

METHODS

Since 1999, 10 cases involving 14 digital defects associated with exposure of bone or tendon were treated by using the reversed digital arterial island flap with digital vein and digital dorsal cutaneous nerves anastomosis.

RESULTS

All the flaps were 100% survived and the result is satisfactory.

CONCLUSIONS

The reversed digital arterial island flap with anastomosing the digital vein and dorsa digita nerve is a safe, and simple technique, which can maintain the finger's normal appearance and reduce the incidence of venous crisis and improve the survival rate of the flap.

Plant stanol fatty acid esters inhibit cholesterol absorption and hepatic hydroxymethyl glutaryl coenzyme A reductase activity to reduce plasma levels in rabbits

The aim of this study was to study the inhibitory effect of dietary stanols (campestanol and sitostanol) fatty acid esters (SE) on intestinal cholesterol absorption. New Zealand white rabbits were fed regular chow alone or enriched with 0.2% cholesterol, 0.33% SE + cholesterol, 0.66% SE + cholesterol, 1.2% SE + cholesterol, 2.4% SE + cholesterol, and 1.2% SE alone. After 2 weeks, plasma cholesterol levels increased 3.6 times in the cholesterol group and did not decrease after addition of 0.33% or 0.66% SE to the cholesterol-enriched diets. However, after addition of 1.2% SE to the cholesterol diet, plasma cholesterol concentration decreased 50% (P <.001), but it did not decrease further after doubling of SE to 2.4%. Percent cholesterol absorption measured by the plasma dual-isotope ratio method was 73.0% +/- 8.1 % in the cholesterol group, which was similar to untreated baseline control. The percent absorption of cholesterol did not decrease significantly after addition of 0.33% or 0.66% SE to the cholesterol diet but decreased 43.8% (P <.001) in the 1.2% SE + cholesterol group, a finding similar to those in rabbits fed 1.2% SE alone. Increasing SE to 2.4% in the cholesterol diet did not further decrease absorption. Hepatic hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase activity reflecting cholesterol synthesis and low-density lipoprotein receptor-mediated binding unexpectedly decreased 67% (P <.01) and 57% (P <.05) in rabbits fed 1.2% SE alone. Increasing dietary SE intake to 1.2% reduced cholesterol absorption and plasma levels. Dietary SE intake below 1.2% was ineffective and above 2.4% did not further decrease percent absorption or plasma cholesterol levels. These results support the hypothesis that dietary SEs competitively displace cholesterol from intestinal micelles to reduce cholesterol absorption and decrease plasma cholesterol levels.

Cholecystectomy prevents expansion of the bile acid pool and inhibition of cholesterol 7alpha-hydroxylase in rabbits fed cholesterol

To study the effect of cholecystectomy on the regulation of classic and alternative bile acid syntheses, gallbladder-intact (n = 20) and cholecystectomized (n = 20) New Zealand White rabbits were fed either chow or chow with 2% cholesterol (3 g/day). After 10 days, bile fistulas were constructed in half of each rabbit group to recover and measure the bile acid pool and biliary bile acid flux. After cholesterol feeding, the bile acid pool size increased from 268 +/- 55 to 444 +/- 77 mg (P < 0.01) with a 2-fold rise in the biliary bile acid flux in intact rabbits but did not expand the bile acid pool (270 +/- 77 vs. 276 +/- 62 mg), nor did the biliary bile acid flux increase in cholecystectomized rabbits. Ileal apical sodium-dependent bile acid transporter protein increased 46% from 93 +/- 6 to 136 +/- 23 units/mg (P < 0.01) in the intact rabbits but did not change in cholecystectomized rabbits (104 +/- 14 vs. 99 +/- 19 units/mg) after cholesterol feeding. Cholesterol 7alpha-hydroxylase activity was inhibited 59% (P < 0.001) while cholesterol 27-hydroxylase activity rose 83% (P < 0.05) after cholesterol feeding in the intact rabbits but neither enzyme activity changed significantly in cholesterol-fed cholecystectomized rabbits. Fecal bile acid outputs reflecting bile acid synthesis increased significantly in the intact but not in the cholecystectomized rabbits fed cholesterol. Removal of the gallbladder prevented expansion of the bile acid pool after cholesterol feeding as seen in intact rabbits because ileal bile acid transport did not increase. As a result, cholesterol 7alpha-hydroxylase was not inhibited.

Intracranial aneurysms: experience in treating 500 patients

OBJECTIVE

To summarize the experience in surgical treatment of patients with intracranial aneurysms.

METHODS

The measures used in the treatment of 500 patients with intracranial aneurysms were retrospectively reviewed with regard to timing of surgery, induced-hypotensive anesthesia, brain protection combined with temporal occlusion of the feeding artery, dynamically monitoring of transcranial Doppler ultrasound, antivasospasm treatment, techniques of direct surgery, and endovascular embolization.

RESULTS

In 465 patients undergoing surgery, intraoperative rupture was observed in 27(6.2%), postoperative death in 13 (2.7%), hemipalsy in 8(2.2%), and vegetative state in 2 (5.0%). The operative mortality was 3.8% in 210 patients before 1990, while 1.9% in 255 patients after 1990.

CONCLUSION

The outcome of patients with intracranial aneurysms can be markedly improved by comprehensive measures.

Complexation of trivalent lanthanide cations by D-ribose in the solid state. The crystal structure and FT-IR study of PrCl3-alpha-D-ribopyranose-5H2O

The crystal structure of praseodymium chloride.alpha-D-ribopyranose pentahydrate, PrCl3-C5H10O5-5 H2O, M(r)=487.47, a=9.1989(8), b=8.8214(7), c=9.8233(9) A, beta=94.060(3) degrees, V=795.2(1) A(3), Z=2, mu=0.71073 A and R=0.0418 for 1923 observed reflections and 172 parameters has been determined. The sugar provides three hydroxyl groups, ax-eq-ax for coordination. The Pr(3+) ion is nine-coordinated with five Pr-O bonds from water molecules, three from hydroxyl groups and one from chloride. The OH, CO stretching vibrations and COH bending vibrations are shifted in the complex IR spectrum and the hydroxyl groups, water molecules, chloride ions form an extensive hydrogen-bond network.

[Bronchial arterial infusion chemotherapy in the treatment of stage III non-small cell lung cancer]

BACKGROUND

To explore the methods of comprehensive treatment of stage III non-small cell lung cancer ( NSCLC) .

METHODS

Treating group consisting of fifty patients with stage III NSCLC was treated with interventional chemotherapy, surgical treatment and radiotherapy, and 42 patients as control.

RESULTS

Resection rate in treating group was 94. 0% after interventional chemotherapy, and 84. 0% of the group got radical resection. The 1-, 3-, 5-year survival rates were 44. 0%, 36. 0%, and 22. 0% in the treating group, and were 23. 8%, 16. 7% and 7. 1% respectively in control group ( P < 0. 05) .

CONCLUSIONS

Standard comprehensive treatment is helpful to improve curative effect of stage III NSCLC.

[A random study on taxol and concomitant radiotherapy vs sequential combined modality in treatment of advanced non-small cell lung cancer]

BACKGROUND

To evaluate the results of taxol and concomitant radiotherapy and those of sequential combined modality chemotherapy with taxol plus cisplatin ( DDP) and radiotherapy in treatment of locally advanced non small cell lung cancer ( NSCLC) .

METHODS

From January 1998 through August 1999, 36 patients ( 24 male, 12 female; 18 squamous cell carcinoma, 14 adenocarcinoma, 4 others; 24 initially treated, 12 retreated) with locally advanced NSCLC were enrolled in this study and were randomized into 2 groups. The median age of the patients was 58. The majority of patients had a performance status of 0 or 1. In concomitant group, the patients received radiation therapy at 2 Gy given on Monday to Friday of each week for 6 to 7 consecutive weeks. The total planned radiation dose was 60 to 65 Gy. At twenty-four hours before radiotherapy, taxol 40 mg / m² was administered on Sunday of each week for 6 consecutive weeks. In sequential group, the patients received induction chemotherapy with taxol 175 mg/ m² and cisplatin 100mg/ m² every 3 weeks for two cycles followed by conventional radiation therapy.

RESULTS

The overall response rate was 66. 7% ( 12/ 18) in concomitant group and 50%( 9/ 18) in sequential group. The local control rate was 83. 3%( 15/ 18) in concomitant group and 50% ( 9/ 18) in sequential group. The main toxicity in concomitant group was esophagitis ( 72. 2%, 13/ 18) . The hematological tox icity and other nonhematological toxicity were mild in concomitant group. The main toxicities in sequential group were leukocytopenia ( 94. 4% , 17/ 18; grade 3/ 4 in 7 patients) , nausea and vomiting ( 94. 4%, 17/ 18; grade 3/ 4 in 5 patients) , alopecia ( grade 3/ 4 in 8 patients) , neurotoxicity ( grade 1/ 2 in 14 patients) and nephrotoxicity ( grade 1/ 2 in 5 patients) . One year survival rate in concomitant group was 50% ( 9/ 18) and in sequential group was 44. 4% ( 8/ 18) . The median survival period was 12 months in concomitant group and 11 months in sequential group.

CONCLUSIONS

Weekly taxol and concomitant radiotherapy is as effective as sequential combined modality in patients with locally advanced NSCLC and concomitant chemoradiotherapy has higher local control rate and lower tox icity except for esophagitis.

Activation of the hexosamine pathway leads to deterioration of pancreatic beta-cell function through the induction of oxidative stress

It is known well that activation of the hexosamine pathway causes insulin resistance, but how this activation influences pancreatic beta-cell function remains unclear. In this study, we found that in isolated rat islets adenovirus-mediated overexpression of glutamine:fructose-6-phosphate amidotransferase (GFAT), the first and rate-limiting enzyme of the hexosamine pathway, leads to deterioration of beta-cell function, which is similar to that found in diabetes. Overexpression of GFAT or treatment with glucosamine results in impaired glucose-stimulated insulin secretion and reduction in the expression levels of several beta-cell specific genes (insulin, GLUT2, and glucokinase). Additionally, the DNA binding activity of PDX-1, an important transcription factor for these three genes, was markedly reduced. These phenomena were not mimicked by the induction of O-linked glycosylation with an inhibitor of O-GlcNAcase, PUGNAc. It was also found that glucosamine increases hydrogen peroxide levels and that several hexosamine pathway-mediated changes were suppressed by treatment with the antioxidant N-acetyl-l-cysteine. In conclusion, activation of the hexosamine pathway leads to deterioration of beta-cell function through the induction of oxidative stress rather than O-linked glycosylation. Thus, the hexosamine pathway may contribute to the deterioration of beta-cell function found in diabetes.

[Value of surgical margin in directing the treatment of early laryngeal carcinoma after partial laryngectomy]

OBJECTIVE

To investigate the value of surgical margin in directing the treatment of early laryngeal carcinoma after partial laryngectomy.

METHODS

We studied 87 cases of T1N0M0 and T2N0M0 laryngeal carcinoma in which the surgical margins were reserved during partial laryngectomy. The recurrence and survival rates between the positive and negative margin groups were compared; the survival between the positive margin groups with postoperative radiotherapy and negative groups; the survival between groups with and without postoperative radiotherapy in negative margins.

RESULTS

Recurrent rate of the negative group was lower than that of the positive group (5.8% vs 33.3%, chi 2 = 10.64 P = 0.001). The estimated survival was higher in the negative group than in the positive group(P = 0.011), and also in tumor-free time(P = 0.007). The survival of those with positive surgical margin and received postoperative RT was lower than that with negative margins(P = 0.01). In the negative group, the difference in the survival between those with or without postoperative RT was not significant (P = 0.405).

CONCLUSION

The prognosis of the positive margin group of the early laryngeal carcinoma was worse than that of the negative group, but postoperative RT can improve it; it is not necessary for the negative group to be treated by postoperative RT.

[Relationship between operative time and therapeutic effectiveness after the optic nerve injuries]

OBJECTIVE

To understand the relationship between the operative opportunity and effectiveness in the optic nerve injuries.

METHOD

Twenty-three cases with optic nerve injuries were undertaken optic canal decompression.

RESULT

The visual acuity in 13 cases were improved after the operation, and progressed about 0.233 averagely. The average time from injuries to operations was (12.90 +/- 16.77) d (3-22 d) in ineffective group. 7 cases of hypoactivity of eyeball recovered in 8 cases.

CONCLUSION

The optic nerve decompression should be done after the patients were treated with megadose of steroid for 48 hours and did not recover. The time had better be no more than 7 days.

[Determination of sarsasapogenin in "tian dong" by TLCS]

This paper reported the determination of sarsasapogenin in 12 samples from 7 species and varieties of Asparagus genus whose commercial name is "Tian-Dong"(Radix Asparagi), Asparagus cochichinensis(Lour.) Merr, A. cochichinensis (lour.) Merr. var. gaudichaudianus (Kunth) X. D. Luo and G. J. Xu, A. taliensis Wang et Tang, A. munitus Wang et Tang, A. myriacanthus Wang et S. C. Chen, A. meioclados Levl and A. trichoclados (Wang et Tang) Wang et S. C. Chen by TLCS. The results showed that it was no pertinence between content of sarsaspogenin with the species, and the content of sarsasapogenin in the tuberous roots was inverse ratio with the commercial grande in same species.

[Study of quantitative calibration model suitability in near-infrared spectroscopy analysis]

Near-infrared spectroscopy is a fast, high efficiency and low cost analytical technique, that depended on analytical models which are built through near-infrared spectra, the primary method results of calibration set and chemometrics methods. The reliability of analytical results mostly depends on the suitability of analytical model to unknown samples. To judge the suitability of analytical model, a new method is presented that combine principle factor analysis (PCA) and Mahalanobis distance. It is different with traditional method, that the Mahalanobis distance is calculated through PCA factor scores. It can avoid the wavelengths selection problem in traditional method of spectral Mahalanobis distance. Through the determination of cetane number of diesel fuel, some factors that affect model suitability judgement are discussed.

[Study on the photoluminescence spectrum of nickel passivation treatment of porous silicon]

A new method for electrolysis passivation treatment of porous silicom (PS) in NiCl2 is reported in this paper. The photoluminescence (PL) spectra of PS treated in different time is observed, the spectra show that peak intensity is 2.5 times stronger than that without treatment, peak wavelength is 33 nm blue shift when PS is treated properly. The phenomenon caused is that the results of the SiHx change into SiNix when replaced H by Ni on surface of PS.

[The transcription of interleukin-8 in gastric epithelial cells by Helicobacter pylori strains in Chinese]

OBJECTIVE

To observe the effect of the vac A genotype and the existence of cag pathogenicity island (cag PAI) of Helicobacter pylori (Hp) isolated from Chinese patients on the transcription of IL-8 in gastric epithelial cells.

METHODS

The genotype of vac A and the existence of cag PAI of Hp were determined by gene sequencing and Southern blot, respectively; the constructed L5F11 cells were cocultured with the bacteria and the transcription of interleukin-8(IL-8) was indicated by luciferase activity and the cytotoxin activity showed by using HeLa cell vacuolating assay.

RESULTS

The ability to induce luciferase by the strains with complete cag PAI (n = 15) was much higher than that by the wild cag negative strain G50[(0.47 +/- 0.09) x 10(6) cpm vs (0.13 +/- 0.02) x 10(6) cpm, P < 0.01] and there was no difference in the luciferase activity induced by the strains with partial cag (n = 4) and by G50[(0.23 +/- 0.08) x 10(6) cpm vs (0.13 +/- 0.02) x 10(6) cpm, P > 0.05]; Also no difference was found in the luciferase activity induced by the strains with vac A s1/m1 (n = 5) and the strains with s1/m2 (n = 14) [(0.29 +/- 0.12) x 10(6) cpm vs (0.53 +/- 0.41) x 10(6) cpm, P > 0.05] although the formers had much higher vacuolating cytotoxin activity than the latters (P < 0.001).

CONCLUSION

The transcription of IL-8 in gastric epithelial cells induced by Hp isolated from Chinese patients was associated with the existence of cag PAI and not with the genotype of vac A.

[Morphology of abdominal aortic aneurysm and its clinical importance]

OBJECTIVE

To investigate the morphology of abdominal aortic aneurysms(AAA) and anatomical importance in endovascular surgery.

METHODS

The images of AAA were measured by spiral CT angiography in 30 patients from January 1998 to December 2000.

RESULTS

The mean diameter of AAA was 5.9 cm (range: 4.0-12.2). The diameter of AAA was positively correlated with neck angle (r = 0.47, P < 0.05) and negatively correlated with neck length(r = -0.41, P < 0.05). Twelve patients(40%) were anatomically feasible for endovascular repair (EVR); 18 patients were excluded for EVR due to angulated proximal necks (mean 88.8 degrees, range 70 degrees-110 degrees) (16 patients; 53.3%), short neck (1; 3.3%), and unilateral common iliac artery occlusion with thrombosis in neck (1; 3.3%).

CONCLUSION

The angulated neck was a major single factor for excluding Chinese patients from EVR.

XPD exon 10 and 23 polymorphisms and DNA repair in human skin in situ

Forty-four Finnish volunteers who were previously studied with regard to the repair rate of UV-specific cyclobutane pyrimidine dimers in the skin were genotyped for XPD polymorphisms at codons 312 (exon 10 G-->A, Asp-->Asn) and 751 (exon 23 A-->C, Lys-->Gln). The repair rate was measured at 24 h for two different cyclobutane dimers. The data did not show consistent XPD genotype-specific differences in DNA repair rates among all subjects. The combined exon 10 AA and exon 23 CC genotype was associated with an approximately 50% depression of repair rate but this was of borderline statistical significance. However, the exon 23 C allele was associated with depressed repair among subjects aged 50 years or older and the result was consistent with both dimers.

[Revision endoscopic sinus surgery on chronic sinusitis and polyps]

OBJECTIVE

To study the indications, surgical landmarks, surgical significance, complications and operative avoidance of revision endoscopic sinus surgery on chronic sinusitis and polyps.

METHOD

We performed revision endoscopic sinus surgery on 112 cases of chronic sinusitis and polyps under controlled hypotension anaesthesia by using the Messerklinger technique and Stryker debrider.

RESULT

89 cases were successful and 17 unresolved, 6 failed, all the complications consist of cerebrospinal fistula in one, orbital hematoma in four, increased tearing in three and profuse bleeding in 6 patients.

CONCLUSION

Revision endoscopic sinus surgery was advised in case of sinuous obstruction caused by uncontrolled lesions under postoperative care, which can do good for adhesion and obstruction except nasal polyposis. The remanet of the middle turbinate and the upper arch of choana were helpful operative landmarks. Preoperative CT scan decrease the complications.

Physician executives report high job satisfaction. Summary of findings from a survey of senior physician executives

The role of the senior physician executive is well established in American hospitals and health systems. There is little research, however, on overall physician executive job satisfaction, their perceptions of their organizational role and job performance, or their views of the medical staffs with which they work. A recent survey of physician executives examined these and other areas. It found physician executives to be quite satisfied with their jobs. What follows is a summary of the findings. An article based on the survey will be featured in a future issue of The Physician Executive.

[Improvement of proliferation of intrasplenically transplanted fetal hepatocytes after immunoadsorption]

OBJECTIVE

To investigate whether removing the compartments of hemopoietic stem cells by immunoadsorption would improve the proliferation of fetal hepatocytes after transplantation.

METHODS

The purification of fetal hepatocytes was performed by immunoadsorption, and the proliferative capability of fetal hepatocytes after intrasplenic transplantation was evaluated by image analysis and flowcytometry analysis.

RESULTS

The yield of fetal hepatocytes after immnoadsorption was (2~3)+/-10(7) in total per fetal liver and the viability is over 85%. The square densities of fetal hepatocytes with image analysis at 3, 7, and 14 days after transplantation were (1603+/-337), (3788+/-605), (8129+/-1025) micrometer(2)/mm(2), and the adult hepatocytes were (1007+/-128), (2013+/-242), (3780+/- 772) mum(2)/mm(2) accordingly. The S phase rates of fetal hepatocytes by flowcytometry analysis were (14.25+/-4.11)%, (16.07+/-5.35)%, and (17.32+/-5.17)%, and the rates of adult hepatocytes were (5.66+/-1.02)%, (4.98+/- 0.74)%, and (6.83+/-1.37)% correspondingly. The S phase rates and the square densities of fetal hepatocytes were significantly higher than those of adult hepatocytes.

CONCLUSIONS

Fetal hepatocytes are highly proliferative and potentially suitable as donor cells in hepatocytes transplantation after immunoadsorption.

Electrochemiluminescence of tris(2,2'-bipyridine)ruthenium(II) immobilized in poly(p-styrenesulfonate)-silica-Triton X-100 composite thin-films

The electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)3(2+)] immobilized in poly(p-styrenesulfonate) (PSS)-silica-Triton X-100 composite films was investigated. The cooperative action of PSS, sol-gel and Triton X-100 attached Ru(bpy)3(2+) to the electrode strongly, and the presence of Triton X-100 prevented drying fractures of the sol-gel films during gelation and even on repeated wet-dry cycles. The modified electrode was used for the ECL detection of oxalate, tripropylamine (TPA) and NADH in a flow injection analysis (FIA) system with a newly designed flow cell. The detection scheme exhibited good stability, short response time and high sensitivity. Detection limits were 0.1, 0.1 and 0.5 micromol L(-1) for oxalate. TPA and NADH, respectively, and the linear concentration range extended from 0.001 to 1 mmol L(-1) for the three analytes. Applications of the flow cell in ECL and electrochemical detection, as well as the immobilization of reagents based on the cooperative action, are suggested.

Role of the cystine-knot motif at the C-terminus of rat mucin protein Muc2 in dimer formation and secretion

DNA constructs based on the 534-amino-acid C-terminus of rat mucin protein Muc2 (RMC), were transfected into COS cells and the resultant (35)S-labelled dimers and monomers were detected by SDS/PAGE of immunoprecipitates. The cystine-knot construct, encoding the C-terminal 115 amino acids, appeared in cell lysates as a 45 kDa dimer, but was not secreted. A construct, devoid of the cystine knot, failed to form dimers. Site-specific mutagenesis within the cystine knot was performed on a conserved unpaired cysteine (designated Cys-X), which has been implicated in some cystine-knot-containing growth factors as being important for intermolecular disulphide-bond formation. Dimerization of RMC was effectively abolished. Each cysteine (Cys-1-Cys-6) comprising the three intramolecular disulphide bonds of the cystine knot was then mutated. Dimer formation was impaired in each case, although much less so for the Cys-3 mutant than the others. Abnormal high-molecular-mass, disulphide-dependent aggregates formed with mutations Cys-1, Cys-2, Cys-4 and Cys-5(,) and were poorly secreted. It is concluded that the intact cystine-knot domain is essential for dimerization of the C-terminal domain of rat Muc2, and that residue Cys-X in the knot plays a key role. The structural integrity of the cystine knot, maintained by intramolecular bonds Cys-1-Cys-4, Cys-2-Cys-5 and Cys-3-Cys-6, also appears to be important for dimerization, probably by allowing correct positioning of the unpaired Cys-X residue for stable intermolecular cystine-bond formation.

[Antioxidation of flavones of wheat germ on mammary tumor of rats]

The effect of flavonoids of wheat germ on mammary tumor of rats induced by 7,12-dimethylben(a) anthracene (DMBA) was investigated. Sprague-Dawley female rats (50 day-old, weighted around 176 g) were randomly divided into 4 groups. The negative and positive control group were fed on stoke diet. The high and low dose test groups were fed on diets with wheat germ flavonoids 10 and 2 g/kg respectively. Except rats in the negative control group, each rat was given DMBA 15 mg dissolved in 1.5 ml vegetable oil by tube feeding. After the administration of DMBA for 24 weeks, the incidence of tumor in the high dose test group was lower than that in the positive control group. The activity of blood and liver glutathione peroxidase (GSH-Px) and peroxidase dismutase(SOD) in the test groups was significantly higher than those in the positive control group, while the MDA level was significantly lower. The results suggested that the effect of flavonoids on inducing peroxidase might be one of the chemical prevention mechanisms on mammary tumors.