Agricultural intensification leads to higher nitrate levels in Lake Ontario tributaries

Eutrophication remains the most widespread water quality impairment globally and is commonly associated with excess nitrogen (N) and phosphorus (P) inputs to surface waters from agricultural runoff. In southern Ontario, Canada, increases in nitrate (NO3-N) concentrations as well as declines in total phosphorus (TP) concentration have been observed over the past four decades at predominantly agricultural watersheds, where major expansions in row crop production at the expense of pasture and forage have occurred. This study used a space-for-time approach to test whether 'agricultural intensification', herein defined as increases in row crop area (primarily corn-soybean-winter wheat rotation) at the expense of mixed livestock and forage/pasture, could explain increases in NO3-N and declines in TP over time. We found a clear, positive relationship between the extent of row crop area within watersheds and NO3-N losses, such that tributary NO3-N concentrations and export were predicted to increase by ~0.4 mg/L and ~130 kg/km2 respectively, for every 10% expansion in row crop area. There was also a significant positive relationship between row crop area and total dissolved phosphorus (TDP) concentration, but not export, and TP was not correlated with any form of landcover. Instead, TP was strongly associated with storm events, and was more sensitive to hydrologic condition than to landcover. These results suggest that pervasive shifts toward tile-drained corn and soybean production could explain increases in tributary NO3-N levels in this region. The relationship between changes in agriculture and P is less clear, but the significant association between dissolved P and row crop area suggests that increased adoption of reduced tillage practices and tile drainage may enhance subsurface losses of P.

Anti-biofilm studies of synthetic imidazolium salts on dental biofilm in vitro

Objective

Biofilm formation under cariogenic conditions contributes to dental caries development, in which Streptococcus mutans (S. mutans) is regarded as the major cariogenic bacteria. Here, we synthesized a series of imidazolium salts. Their properties of antimicrobial and anti-biofilm were investigated.

Methods

The microdilution method crystal violet staining, and cell counting Kit-8 assay were used to screen imidazolium salts. Then, the bacterial composition in multi-species biofilm composed of S. mutans, Actinomyces naeslundii, and Streptococcus gordonii was quantified by quantitative PCR. The exopolysaccharide and morphology of the structure of multi-species biofilm were further observed by confocal laser scanning microscopy and scanning electron microscope, respectively.

Results

Imidazolium salts exhibited highly antimicrobial activity against oral pathogens, especially for S. mutans . Compounds with ortho-diisopropyl and para-methoxyl on N-moieties as well as bearing ancenaphthyl skeleton (C5) showed the lowest cytotoxicity and most efficient anti-biofilm activity. C5 inhibited approximately 50% of multi-species biofilm at 0.98 μg/mL. Notably, C5 resulted in 98.97% live S. mutans and 77.65% A. naeslundii decreased. Furthermore, the exopolysaccharide was reduced by 88%, along with a sparse and scattered microstructure.

Conclusion

The imidazolium salts present low cytotoxicity and remarkable antimicrobial activity against S. mutans in multi-species biofilm, suggesting that they may have a great potential in anti-biofilm clinical applications.

Bulky Pd-PEPPSI-Embedded Conjugated Microporous Polymers-Catalyzed Suzuki-Miyaura Cross-Coupling of Aryl Chlorides and Arylboronic Acids

Through post-synthesis method, a type of bulky N-heterocyclic carbenes (NHCs) functionalized conjugated microporous polymers to supported the palladium-based molecular catalyst has been developed. The resulting heterogeneous catalyst Pd-PEPPSI-CMP, showing greater...

Buchwald-Hartwig Amination of Coordinating Heterocycles Enabled by Large-but-Flexible Pd-BIAN-NHC Catalysts*

A new class of large-but-flexible Pd-BIAN-NHC catalysts (BIAN=acenaphthoimidazolylidene, NHC=N-heterocyclic carbene) has been rationally designed to enable the challenging Buchwald-Hartwig amination of coordinating heterocycles. This robust class of BIAN-NHC catalysts permits cross-coupling under practical aerobic conditions of a variety of heterocycles with aryl, alkyl, and heteroarylamines, including historically challenging oxazoles and thiazoles as well as electron-deficient heterocycles containing multiple heteroatoms with BIAN-INon (N,N'-bis(2,6-di(4-heptyl)phenyl)-7H-acenaphtho[1,2-d]imidazol-8-ylidene) as the most effective ligand. Studies on the ligand structure and electronic properties of the carbene center are reported. The study should facilitate the discovery of even more active catalyst systems based on the unique BIAN-NHC scaffold.

BIAN-NHC Ligands in Transition-Metal-Catalysis: A Perfect Union of Sterically Encumbered, Electronically Tunable N-Heterocyclic Carbenes?

The discovery of NHCs (NHC = N-heterocyclic carbenes) as ancillary ligands in transition-metal-catalysis ranks as one of the most important developments in synthesis and catalysis. It is now well-recognized that the strong σ-donating properties of NHCs along with the ease of scaffold modification and a steric shielding of the N-wingtip substituents around the metal center enable dramatic improvements in catalytic processes, including the discovery of reactions that are not possible using other ancillary ligands. In this context, although the classical NHCs based on imidazolylidene and imidazolinylidene ring systems are now well-established, recently tremendous progress has been made in the development and catalytic applications of BIAN-NHC (BIAN = bis(imino)acenaphthene) class of ligands. The enhanced reactivity of BIAN-NHCs is a direct result of the combination of electronic and steric properties that collectively allow for a major expansion of the scope of catalytic processes that can be accomplished using NHCs. BIAN-NHC ligands take advantage of (1) the stronger σ-donation, (2) lower lying LUMO orbitals, (3) the presence of an extended π-system, (4) the rigid backbone that pushes the N-wingtip substituents closer to the metal center by buttressing effect, thus resulting in a significantly improved control of the catalytic center and enhanced air-stability of BIAN-NHC-metal complexes at low oxidation state. Acenaphthoquinone as a precursor enables facile scaffold modification, including for the first time the high yielding synthesis of unsymmetrical NHCs with unique catalytic properties. Overall, this results in a highly attractive, easily accessible class of ligands that bring major advances and emerge as a leading practical alternative to classical NHCs in various aspects of catalysis, cross-coupling and C-H activation endeavors.

"Bulky-Yet-Flexible" α-Diimine Palladium-Catalyzed Reductive Heck Cross-Coupling: Highly Anti-Markovnikov-Selective Hydroarylation of Alkene in Air

To pursue a highly regioselective and efficient reductive Heck reaction, a series of moisture- and air-stable α-diimine palladium precatalysts were rationally designed, readily synthesized, and fully characterized. The relationship between the structures of the palladium complexes and the catalytic properties was investigated. It was revealed that the"bulky-yet-flexible"palladium complexes allowed highly anti-Markovnikov-selective hydroarylation of alkenes with (hetero)aryl bromides under aerobic conditions. Further synthetic application of the present protocol could provide rapid and straightforward access to functional and biologically active molecules.

Rigid hindered N-heterocyclic carbene palladium precatalysts: synthesis, characterization and catalytic amination

Rigid hindered N-heterocyclic carbene palladium complexes have been developed and exhibited high activities for a variety of (hetero)aryl chlorides with (hetero)anilines and amines under aerobic conditions.

Direct C–H heteroarylation by an acenaphthyl-based α-diimine palladium complex: improvement of the reaction efficiency for bi(hetero)aryls under aerobic conditions

A bulky ancenaphthyl skeleton-based α-diimine palladium complex has been developed, which exhibited high reactivity for direct heteroarylation of heteroaryl bromides under aerobic conditions with a broad substrate scope.

Analysis of two sling procedures using polypropylene mesh for treatment of stress urinary incontinence

OBJECTIVES

To evaluate and compare the surgical outcome between the innovative tension-free vaginal tape (TVT) and conventional pubovaginal sling (PVS) procedures using polypropylene mesh.

METHODS

Eighty consecutive women with urodynamic stress urinary incontinence (SUI), who chose to undergo either a TVT (n=23) or a PVS (n=57) procedure using polypropylene mesh based on financial consideration, were recruited for this study. The surgical results were analyzed and compared subjectively and objectively.

RESULTS

The mean follow-up interval was 23 months for the TVT and 20 months for the PVS procedure (P=0.062). Postoperatively, SUI (91.3% vs. 93.0%), concomitant urge symptoms (85.0% vs. 85.3%) and the negative impact of incontinence and urogenital distress on patients' quality of life (79.8% vs. 77.8%) (77.4% vs. 68.8%) had improved markedly. After a multivariable logistic regression analysis, the treatment outcome of SUI was found to be independent of the main effects of patient age, parity, concurrent gynecological surgeries, intrinsic sphincter deficiency, previous failed incontinence surgeries, and concomitant urge symptoms. However, it was significantly related to treatment procedures (TVT vs. PVS) and their interaction with patient body mass index (BMI). Based on the fitted logistic model, we see that TVT performs better than PVS when BMI is less than 27.27 kg/m2, and the advantage of TVT decreases as BMI increases.

CONCLUSION

Both TVT and PVS procedures using polypropylene mesh are effective treatment modalities for female SUI. However, TVT was not as effective in treating overweight or obese women as PVS.

Camphyl-based α-diimine palladium complexes: highly efficient precatalysts for direct arylation of thiazoles in open-air

Bulky camphyl-based α-diimine palladium complexes have been developed and exhibited high reactivity for the direct arylation of thiazoles in air.

[Analysis of cardiac troponin C gene TNNC1 c. G175C mutation in a Chinese pedigree with familial hypertrophic cardiomyopathy and the correlation between genotype and phenotype]

Objective: To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy (HCM )focusing on the cardiac troponin C gene TNNC1 c. G175C mutation. Methods: All family members of a Chinese pedigree with hypertrophic cardiomyopathy admitted in Third People's Hospital of Qingdao in February 2005 and 200 healthy volunteers were included in this study. The coding exons of 30 hypertrophic cardiomyopathy associated genes were identified by whole exons amplification and high-throughput sequencing in the proband, and the identified mutation were further detected through bi-directional Sanger sequencing in all family members and 200 healthy volunteers. Pedigree analysis included clinical manifestation, physical examination, ECG and echocardiogram. Results: A missense mutation c. G175C was identified in the TNNC1 gene in 2 family members, which resulted in a glutamic acid (E) to glutamine (Q) exchange at amino acid residue 59. A mutation c. A1319G was identified in the MYLK2 gene in 1 family member, which resulted in a lysine (K) to arginine (R) exchange at amino acid residue 440. These mutations were absent in 200 healthy controls. The proband carried the two kinds of mutations and expressed various clinical manifestations of heart failure and had history of ventricular tachycardia, paraxial atrial fibrillation, pacemaker implantation, electrocardiogram showed right bundle branch block and echocardiography examination evidenced thickened interventricular septum (23.3 mm) and apex and reduced wall motion of these segments. The daughter of the proband carried the TNNC1 c. G175C mutation and was also diagnosed with asymptomatic HCM by echocardiography with thickened interventricular septum (19 mm) and apex (15 mm). Conclusion: The novel missense mutation of TNNC1 c. G175C might be the disease-causing gene mutation in this Chinese pedigree with familiar HCM.

Bulky α-diimine palladium complexes: highly efficient for direct C–H bond arylation of heteroarenes under aerobic conditions

Through the strategy to enhance the bulkiness on both the backbone and the N-aryl moieties, we designed and synthesized a type of bulky α-diimine palladium complex (i.e., {[Ar–NC(R)–C(R)N–Ar]PdCl₂, (Ar = 2-benzhydryl-4,6-dimethylphenyl)}, C1, R = H; C2, R = An; C3, R = Ph).

Dichlorido{2-[(2,6-dimethyl-phen-yl)imino-meth-yl]pyridine-κN,N'}zinc

In the asymmetric unit of the title compound, [ZnCl(2)(C(14)H(14)N(2))], the central Zn(II) ion is four-coordinated in a distorted tetra-hedral environment by two N atoms of the ligand 2-[(2,6-dimethyl-phen-yl)imino-meth-yl]pyridine and two chloride anions. In the crystal, adjacent mol-ecules are connected through C-H⋯Cl hydrogen bonds between a C-H group of the ligand and a Cl(-) anion, leading to a chain-like structure along the b direction.

Dichlorido[1-(2,6-dimethylphenylimino)-1,2-diphenylpropan-2-ol-κ2N,O]palladium(II) methanol monosolvate

The title compound, [PdCl₂(C₂₃H₂₃NO)]·CH₃OH, was obtained by the reaction of 1-(2,6-dimethyl­phenyl­imino)-1,2-diphenyl­propan-2-ol and palladium chloride in methanol. The Pd atom is four-coordinated by the O atom of a tertiary alcohol, the imine N atom of the hy­droxy­limine part of the bidentate ligand and by two chloride ions, forming a nearly square-planar geometry. The complex mol­ecule and the uncoordinated methanol mol­ecule are connected via an O—H⋯O hydrogen bond.

Factors that affect recurrence after anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh

The purpose of this study was to evaluate the effectiveness of the anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh in patients with severe (stage III or IV) anterior vaginal prolapse. Thirty-eight consecutive women were enlisted for this prospective study. The procedure consisted of an extensive vaginal dissection to join the vesicovaginal and retropubic space and an anchoring of a polypropylene mesh patch between the two Arcus Tendineus Fasciae Pelvis in a tension-free manner. The mean age of the study group was 63 (33-80) years. The success rate was 87% (33/38) at a mean follow-up interval of 21 (12-29) months. A total of eight (100%) patients were also cured of concomitant stress incontinence (five overt and three occult type) with an additional tension-free vaginal tape (TVT) operation. During follow-up, there were five de-novo stress incontinence cases (16.7%) and four vaginal erosions of mesh (10.5%). Four clinical variables--diabetes mellitus, recurrent anterior vaginal prolapse, chronic cough and vaginal erosions of mesh--were found to have a significant correlation with an unsatisfactory surgical result with large values of hazard ratios found by survival analysis. We concluded that the anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh was effective for most, but failed in some patients who had specific risk factors within short convalescence periods. Concomitant stress incontinence can be successfully treated by a TVT operation in combination with the anterior colporrhaphy procedure reinforced with four-corner anchored polypropylene mesh. However, the anterior colporrhaphy procedure may itself have adverse effects on urethral sphincter function.

KAI1 metastasis suppressor gene is frequently down-regulated in cervical carcinoma

KAI1 is a metastasis suppressor gene located on human chromosome 11p11.2. It belongs to a structurally distinct family of cell surface glycoproteins. Decreased KAI1 expression has been observed in several common solid epithelial tumors, including prostatic, pancreatic, lung, hepatic, colorectal, ovarian, and esophageal cancers. A recent study also observed frequent loss of KAI1 expression in a number of squamous cell carcinomas of the cervix by immunohistochemical technique. To further confirm whether this gene is altered in this malignancy, we analyzed KAI1 expression in various stages of cervical carcinoma by a molecular method. Total cellular RNA was extracted from 84 primary invasive cervical carcinomas and 6 metastatic or recurrent lesions. cDNA was synthesized and was used for real-time quantitative polymerase chain reaction analysis. The level of KAI1 expression was obtained as the value of threshold cycle (Ct) and was quantitated with a comparative Ct method. In addition, paraffin blocks of the tumors were selected and prepared for immunohistochemical study with an anti-KAI1 polyclonal antibody, C-16. Both the real-time quantitative polymerase chain reaction method and immunohistochemical study revealed a frequent decrease in KAI1 expression in invasive cervical cancers and metastatic or recurrent lesions. However, the reduction in KAI1 was not related to progression of the disease. When tumor cell differentiation was analyzed, poorly differentiated tumors showed a greater decrease in KAI1 expression than well or moderately differentiated tumors (P < 0.001). Histologically, KAI1 loss was observed equally in both squamous cell carcinoma and adeno-/adenosquamous carcinoma. Since down-regulation of KAI1 occurs in both early and late stages of cervical cancer, we suggest that its involvement in the progression of this malignancy is an early event.

[Application of wide-bore capillary gas chromatography in the synthesis of special esters of methacrylic acid]

A simple, rapid and accurate method for separating and analysing components in the synthesis of special esters of methacrylic acid by gas chromatography is reported. An SE-54 wide-bore capillary column of 50 m x 0.53 mm i.d. x 0.6 microns was used. The esters include dimethylaminoethyl methacrylate(DMAM), n-butyl methacrylate(BMA) and ethylene glycol dimethacrylate(EGDMA). Crude materials such as methyl methacrylate(MMA) and N, N-dimethyl ethanol amine (DMEA) were also analysed. The recoveries were 99.71%-102.89%, and the RSDs of the main components were below 0.1%. The method can be used to control the production of the esters.

FHIT (fragile histidine triad) gene analysis in cervical intraepithelial neoplasia

OBJECTIVE

Recently a candidate tumor suppressor gene, FHIT (fragile histidine triad), was identified at chromosome 3p14.2. Abnormality of this gene has been observed in a variety of human tumors. Although aberrant FHIT transcripts in a substantial percentage of cervical cancer cell lines and primary cervical tumors were also noted, some other studies revealed different results. Therefore, its association with the development of cervical cancer is still debatable. Because allelic loss in chromosome 3p is also a frequent finding in cervical intraepithelial neoplasia (CIN), we compared the transcription pattern and expression of FHIT in the preinvasive cervical lesions and normal cervical epithelia to investigate its possible role in cervical carcinogenesis.

METHODS

Thirty-five consecutive CIN lesions taken from conization specimens and 33 normal cervical epithelial tissues taken from hysterectomy for benign diseases were included in this study. Total RNA was extracted from the pathology-confirmed tissue samples and first-strand cDNA was synthesized. It was amplified using a nested reverse transcription polymerase chain reaction (RT-PCR) method. The PCR products were then subjected to subcloned sequence analysis. Paraffin blocks from all of the samples were selected and prepared for immunohistochemical study with an anti-FHIT polyclonal antibody.

RESULTS

All the cDNAs of CIN and normal cervical epithelial tissues showed the expected size of RT-PCR product. However, 7 of the 35 (20%) CIN lesions and 5 of the 33 (15%) normal cervical epithelia also presented aberrant transcripts in addition to the normal-sized transcript of FHIT. Deletion of the cDNA segment covering exon 4 to exon 8 was the most frequent finding in the cases that showed abnormal FHIT transcripts. FHIT protein was intermediately or strongly expressed in most of the CIN lesions and normal squamous epithelia. However, reduced or absent FHIT expression was observed heterogeneously in the 7 CIN lesions and 5 normal cervices in which aberrant FHIT transcripts were detected.

CONCLUSION

Because the normal-sized FHIT transcript was present robustly in all of the CIN lesions and the abnormal FHIT transcripts occurred with similar frequency and pattern in the CIN lesions and normal cervical tissues, we suggest that abnormal FHIT transcription might not be causal in the early process of cervical carcinogenesis.

p53 mutation is infrequent in clear cell carcinoma of the ovary

OBJECTIVE

p53 gene alteration has been extensively studied in epithelial ovarian cancer. However, its occurrence in clear cell carcinoma, an infrequent histologic subtype of epithelial ovarian cancer, is rarely reported. The aim of this study is to determine the status of p53 gene alteration in this distinct type of ovarian carcinoma.

METHODS

Paraffin blocks of tumors from 38 patients with primary or recurrent ovarian clear cell carcinoma were studied for p53 alteration. All these tumors were subjected to immunohistochemical and molecular analysis. Two monoclonal antibodies (DO-7 and PAb 1801) were used for immunohistochemical staining. Genomic DNAs extracted from paraffin blocks of the 38 tumors were subscribed for a nested polymerase chain reaction/single-strand conformation polymorphism (PCR/SSCP) analysis. Tumors showing band shift on SSCP were further prepared for DNA sequencing to determine the site of mutation.

RESULTS

Overexpression of p53 was observed in only one stage III clear cell carcinoma. However, focal positive p53 staining was noted in another five tumors. Of the six tumors showing positive immunohistochemistry, p53 alterations were noted in four tumors. Three tumors revealed a missense point mutation: two were in exon 7 (TCT(227) --> TTT and GGC(245) --> AGC) and one was in exon 5 (CGC(156) --> CAC). Another tumor revealed a 12-bp deletion in two possible ways: it might involve the last four codons at the 3' end of exon 4 (nucleotides 12,288-12,299) or it might cross over the splice junction between exon 4 and intron 4 (nucleotides 12,290-12,301). The former would result in a predicted protein product of 389 amino acids whereas the latter would cause a frameshift in the gene sequence and would result in a truncated protein.

CONCLUSION

Mutations in p53 appear to be much less frequent in clear cell carcinoma than in other histologic types of epithelial ovarian cancer. We suggest that p53 alterations may not play an important role in the development of clear cell carcinoma.

Predictive factors for residual disease in subsequent hysterectomy following conization for CIN III

OBJECTIVE

The aim of this study was to determine predictive factors for post-cone residual disease in subsequent hysterectomy for CIN III.

METHODS

From June 1994 to June 1999, 120 patients with CIN III who received hysterectomy within 6 months of conization regardless of marginal status were identified from 1450 conization cases. The demographic features and pathologic parameters were analyzed for the predictive rate of post-cone residual disease.

RESULTS

Age >==50 years and parity >==5 were significant factors associated with residual disease. The incidence of residual disease was 56.5 and 29. 3% in patients >==50 and <50 years, respectively, and 61.8 and 36.0% in patients with parity >==5 and <5. Post-cone endocervical curettage (ECC) and multiple-quadrant disease were the only pathologic predictive factors identified. The incidence of residual disease was 64.6 and 29.2% in patients with positive ECC and negative ECC, respectively, and 48.4 and 25.9% in patient with multiple-quadrant disease and one- or two-quadrant disease. Other pathologic parameters, including endocervical margins, ectocervical margins, endocervical gland involvement, and depth of conization, were not predictive of residual disease. When ECC was combined individually with age, endocervical margins, or multiple-quadrant disease, there was no increase of positive predictive rate.

CONCLUSIONS

(1) Age 50 years or more and parity >==5 were two demographic features that predicted post-cone residual disease. (2) ECC and multiple-quadrant disease were the only pathologic parameters that predicted post-cone residual disease. (3) With the appropriate application of the predictive factors, post-cone hysterectomy may be further decreased.

Ultrasonic diagnosis of ureteral injury after laparoscopically-assisted vaginal hysterectomy

Ureteral injuries are uncommon but serious complications of laparoscopically-assisted vaginal hysterectomy. The ureter is particularly at risk for inadvertent injury when the cardinal-uterosacral ligament complex is coagulated and divided below the uterine vessels. We present two recent cases which describe the application of transabdominal ultrasound including color Doppler mapping in the diagnosis of ureteral injury after laparoscopically-assisted vaginal hysterectomy. Transabdominal ultrasound including color Doppler mapping has great diagnostic potential as a method for non-invasive evaluation of post-operative ureteral conditions. Ultrasonic triads (absence of a ureteric jet, ascites, and the presence or absence of hydronephrosis) are capable of differentiating diagnosis of complete, partial, or nonobstructive surgical ureteral injuries.

Frequent down-regulation and lack of mutation of the KAI1 metastasis suppressor gene in epithelial ovarian carcinoma

OBJECTIVE

KAI1 is a recently identified metastasis suppressor gene on human chromosome 11p11.2. It belongs to a structurally distinct family of cell surface glycoproteins. Decreased KAI1 expression seems to be involved in the progression of human prostate, lung, pancreatic, and possibly breast cancer, and recently a reduced KAI1 protein expression has been demonstrated in several ovarian carcinoma cell lines. The aim of this study is to determine whether the KAI1 gene is altered in human epithelial ovarian carcinomas. In addition, its prognostic significance in this tumor is also evaluated.

METHODS

To detect KAI1 expression, 102 tumor samples from benign, borderline, primary invasive, metastatic, and recurrent epithelial ovarian tumors were prepared for immunohistochemical study with C-16, an anti-KAI1 polyclonal antibody. In addition, cellular RNA from 24 primary invasive and 7 recurrent tumors was also analyzed for KAI1 expression by using a reverse transcriptase PCR (RT-PCR) technique. The PCR single-strand conformation polymorphism method and direct DNA sequencing were used to detect KAI1 mutation in the 44 primary invasive and 8 recurrent ovarian carcinomas.

RESULTS

In immunohistochemical study, decrease of KAI1 protein expression was associated with the progression of ovarian tumor. However, it had no relation to the stage of primary invasive cancers because of its frequent occurrence in early stage tumors. KAI1 expression was also frequently down-regulated in primary invasive and recurrent tumors in RT-PCR analysis. Except for a missense change at codon 241 (ATC to GTC), which causes the substitution of a valine for an isoleucine in the amino acid sequence and occurs in both normal and tumor tissues, no mutation of the KAI1 gene was found in any of the 52 carcinomas. Although there was a trend for deteriorating survival from patients with KAI1-preserved tumors to those with KAI1-decreased and -negative tumors, statistically it was not significant (P = 0.079).

CONCLUSION

KAI1 may play a role in the malignant progression of epithelial ovarian carcinoma through the down-regulation of expression rather than gene mutation. Since the decreased expression presented frequently in early stage tumors, it may be an early event in the progression of this tumor and its prognostic significance needs further investigation with a larger number of cases.

Expression and prognostic significance of proliferating cell nuclear antigen and Ki-67 in malignant ovarian germ cell tumors

BACKGROUND

Both proliferating cell nuclear antigen (PCNA) and Ki-67 are proliferative markers known to correlate with the cell proliferative state. The aim of this study was to evaluate the usefulness of PCNA and Ki-67 immunoreactivity in the assessment of clinicopathologic features and prognosis in patients with malignant ovarian germ cell tumors.

METHODS

Thirty-one patients with surgically resected malignant ovarian germ cell tumors were investigated. The clinicopathologic features and survival data of these patients were recorded. Immunohistochemical staining with monoclonal antibodies (PC 10 for PCNA, and MIB-1 for Ki-67) were performed on paraffin embedded tissue from each patient. The correlation of the immunoreactivity of these two markers with the clinicopathologic features and prognosis were studied.

RESULTS

All of the tumors were positive for PCNA and Ki-67, but the intensity of expression varied widely. The immunoreactivity in each tumor was also heterogeneous. The scoring of PCNA and Ki-67 was determined by a semiquantitative method. Both advanced tumor stage (stages III and IV) and high PCNA score (scores 3 and 4) indicated a poorer prognosis for survival than did early stage (stages I and II) and a low PCNA score (scores 1 and 2) (p = 0.017 and p = 0.008, respectively). In addition, the proportion of tumor relapse and tumor-induced death was more accurately predicted by PCNA and Ki-67 scoring than by tumor staging (chi 2 = 0.3159, chi 2 = 0.7186 and chi 2 = 1.9689, respectively).

CONCLUSIONS

PCNA and Ki-67 proliferative markers appear promising to differentiate patients into low- and high-risk groups. In the presence of a high PCNA or Ki-67 score, aggressive postoperative chemotherapy is warranted, even if the disease is in a very early stage.

Mutational analysis of the BRCA1 tumor suppressor gene in endometrial carcinoma

OBJECTIVE

To investigate whether alteration of BRCA1 tumor suppressor gene occurs in sporadic endometrial carcinomas.

METHODS

Genomic DNAs were prepared from 33 consecutively collected endometrial carcinoma tissues for BRCA1 mutational analysis. To screen for BRCA1 mutation, polymerase chain reaction (PCR) amplification and single strand conformation polymorphism (SSCP) technique were used with 41 overlapping PCR primer pairs for the 23 coding exons of BRCA1. Tumors that demonstrated SSCP variants were further subjected to direct DNA sequencing in the appropriate exons to identify the DNA alteration.

RESULTS

In addition to detecting a previously described polymorphism in exon 11, single strand conformation polymorphism analysis of the 33 endometrial cancers identified 3 tumors with mobility shifts. Two tumors shifted in exon 3 and showed the same pattern of band shift. The other tumor shifted in exon 9. DNA sequencing revealed sequence alterations in the 3 tumors; all appeared heterozygous. In the 2 tumors shifted in exon 3, the sequence alteration caused no amino acid change and was consistent with an infrequent silent polymorphism. In the third tumor, a missense alteration at codon 191 was detected and was recognized as germline in origin.

CONCLUSIONS

Because a normal allele of BRCA1 was retained in the tumor where a germline missense alteration was detected, the heterozygous DNA alteration should not be cancer predisposing in terms of the two-hit model for inactivation of the tumor suppressor gene. We conclude that mutation of BRCA1 may not be involved in the development of sporadic endometrial cancer.

Studies of esophageal balloon cytology in Linxian, China

Esophageal cancer is the second leading cause of cancer death in China. Esophageal cancer has a very poor prognosis, principally because most tumors are asymptomatic until they are unresectable. Esophageal balloon cytology is an early detection method developed by Chinese scientists to identify resectable early cancers and precursor lesions. Previous studies have reported high sensitivities for detecting esophageal cancer in symptomatic patients. The current report describes several studies evaluating this diagnostic technique in asymptomatic individuals. A comparison of Chinese and U. S. cytological diagnoses of the same esophageal samples showed that the Chinese categories of precancerous neoplasia were more inclusive than the corresponding U. S. categories. Comparisons of both Chinese and U. S. cytological diagnoses with concurrent histological findings showed low (14-36%) sensitivities for the cytological detection of biopsy-proven cancers. Prospective follow-up studies of several screened cohorts showed a consistent progression of risk for developing esophageal cancer with increasing severity of initial cytological diagnosis. These preliminary studies suggest that esophageal balloon cytology is a useful technique that can benefit from additional research to improve its optimal performance.

High complete response rate of concomitant chemoradiotherapy for locally advanced squamous cell carcinoma of the uterine cervix

A prospective study with a newly designed schedule of concomitant chemoradiotherapy was initiated for 42 patients with previously untreated squamous cell carcinoma of the uterine cervix. Their ages ranged from 34 to 77 years, median 57 years. There were 13 FIGO stage IIB, 1 IIIA, 27 IIIB, and 1 IVA. Radiotherapy was administered using 1.8 Gy/day, 5 days a week, to the whole pelvis (50.4 Gy/28 fractions) with local boost if indicated. Intracavitary brachytherapy of 5 Gy for five times was delivered after 1-2 weeks of rest. The first 21 patients received concomitant chemotherapy of biweekly PEB regimen (100 mg/m2 etoposide + 50 mg/m2 cisplatin + 50 mg/m2 bleomycin) for two to three cycles during external irradiation. The chemotherapy for the latter 21 patients was modified to weekly PEBF (50 mg/m2 etoposide + 20 mg/m2 cisplatin + 10 mg/m2 bleomycin + 800 mg/m2 5-FU, mixed in normal saline, 24-hr continuous iv infusion) for five to six cycles. All except 1 patient achieved complete response (97.6%) and sustain so after a median follow-up time of 30 months. There were three relapses--one with persistent pelvic disease and two with distant metastasis. Two-year overall survival and disease-free survival rates were 97.6 and 92.9%, respectively. Myelosuppression was moderate but fully recovered. Other acute toxicities were tolerated except for 1 patient who encountered grade IV radiation colitis with cecum perforation and required surgery. As to late morbidity, the incidence of radiation proctitis was high (21.4%) but of a mild degree, with 1 patient needing repeated transfusion. One patient developed chronic cystitis with an acontractile bladder. Our preliminary results show that concomitant chemoradiotherapy for advanced cervical carcinoma is both feasible and effective with acceptable toxicities. Further follow-up is mandatory to ensure whether this high complete response protocol will translate into long-term local control and survival.

Overexpression of p53 is not a feature of ovarian granulosa cell tumors

The p53 tumor suppressor gene has been extensively studied in various human tumors including epithelial ovarian cancers. However, little is known about the expression of this gene in ovarian granulosa cell tumors, the most common histologic type of sex cord-stromal tumors. We investigated whether overexpression of the p53 gene product occurs in this specific ovarian tumor. Nineteen patients with ovarian granulosa cell tumors were recruited in this study. Immunohistochemical staining for the p53 protein with monoclonal antibody PAb 1801 was performed in the paraffin-embedded tissue of each case to screen for p53 overexpression. Among the 19 ovarian granulosa cell tumors, there was only one well-differentiated tumor found to have nuclear immunoreactivity in a small fraction of tumor cells. Polymerase chain reaction--single-stranded conformation polymorphism was used to study the tumor showing focal p53 positivity, but no mobility shift was noted from exon 4 through exon 9 of the p53 gene. On the basis of this observation, we propose that alteration of the p53 tumor suppressor gene is not a common finding in ovarian granulosa cell tumors.