Value of human papillomavirus deoxyribonucleic acid testing after conization in the prediction of residual disease in the subsequent hysterectomy specimen

OBJECTIVE

Our aim was to evaluate human papillomavirus deoxyribonucleic acid testing after conization in predicting residual disease in the subsequent hysterectomy specimen.

STUDY DESIGN

A prospective study was conducted on 75 patients with grade 3 cervical intraepithelial neoplasia who had cone margins or endocervical curettage specimens showing disease and who elected to undergo hysterectomy after conization. All patients underwent high-risk human papillomavirus deoxyribonucleic acid testing by the Hybrid Capture II (Digene Corporation, Gaithersburg, MD) system before conization and at the time of hysterectomy (within 2-7 weeks after conization). The presence of human papillomavirus deoxyribonucleic acid in cells obtained by endocervical brush before hysterectomy was correlated with residual disease in the hysterectomy specimens.

RESULTS

Of the 92 patients enrolled, 75 were eligible. Of these 75 patients, 52 (69.3%) had persistent human papillomavirus deoxyribonucleic acid after conization, and 27 (36.0%) of the 75 patients had residual cervical neoplasia in the hysterectomy specimens. Those with negative results for human papillomavirus deoxyribonucleic acid after conization were all (23/23) without residual disease in the uterus (100% negative predictive value). All those who had residual disease (27/27) had positive results for human papillomavirus deoxyribonucleic acid at the time of hysterectomy (100% sensitivity). Postconization human papillomavirus deoxyribonucleic acid status (odds ratio, 4.000; 95% confidence interval, 1.531-10.449; P =.005) and grade of dysplasia after endocervical curettage (classified as grade 2 cervical intraepithelial neoplasia or less severe disease vs grade 3 cervical intraepithelial neoplasia: odds ratio, 6.612; 95% confidence interval, 2.837-15.409; P =.0002) were significantly associated with residual tumor in the uterus.

CONCLUSIONS

This prospective study confirms an excellent sensitivity and negative predictive value of human papillomavirus deoxyribonucleic acid testing after conization in predicting residual cervical neoplasia. A strategy of managing patients with grade 3 cervical intraepithelial neoplasia, based on postconization human papillomavirus deoxyribonucleic acid findings and endocervical curettage results, is proposed.

Susceptibility of mosquitoes in central Taiwan to natural infections of Dirofilaria immitis

From October 1997 to September 1998, 3085 Culex quinquefasciatus (Say) (Diptera: Culicidae), 584 Cx. tritaeniorhynchus (Giles) (Diptera: Culicidae), 392 Cx. annulus (Theobald) (Diptera: Culicidae), 374 Aedes albopictus (Skuse) (Diptera: Culicidae) and 102 Armigeres subalbatus (Coquillet) (Diptera: Culicidae) were collected and examined for Dirofilaria immitis (Leidy) (Spirurida: Filariidae) infection. However, only Cx. quinquefasciatus and Ae. albopictus were infected, with a prevalence of 4.28% and 3.74%, respectively. The intensity of D. immitis found in Ae. albopictus (3.43 larvae/mosquito) was higher than that found in Cx. quinquefasciatus (2.89 larvae/mosquito). After being fed with canine blood containing 7500 microfilariae (mf) per mL, Cx. quinquefasciatus ingested approximately two times as many mf as Ae. albopictus (mean of 31.73 in comparison to 16.47). However, almost three times as many third-stage infective larvae developed in Ae. albopictus as in Cx. quinquefasciatus (mean of 3.25 as compared with 1.10), with a vector efficiency index (VEI) of 19.73 and 3.47, respectively. The results showed that Cx. quinquefasciatus and Ae. albopictus served as natural vectors of D. immitis in central Taiwan. Although Ae. albopictus was more efficient for heartworm transmission, Cx. quinquefasciatus may play a more prominent role on the transmission of dirofilariasis in central Taiwan.

Identification of the human crooked neck gene by comparative gene identification

Drosophila melanogaster serves as a useful model organism for functional genomic studies, and its genome project was recently completed. We previously described a comparative-gene-identification approach to assist human ortholog gene identification that involves applying an entire proteome as an alignment template. Analysis of the available 14100 Drosophila protein sequences revealed that 37% of them (5228 sequences) might lead to discoveries of novel human genes. Upon further database interrogations, we found several putative full-length human gene transcripts, including the human crooked neck (crn) gene. Based on sequence gap-closure experiments using reverse transcriptase-polymerase chain reaction as well as bioinformatic analysis, we found that the assembled human cDNA contig of crooked neck gene was at least 3903 base pairs in length with alternative splicing variations which encoded mainly for a 687-amino-acid residue protein. The human crooked neck gene was located on chromosome 20 with at least 15 exons. The unique features of the 16 copies of the tetratrico peptide repeat (TPR) motif were conserved in the yeast, fly and human crooked neck orthologous proteins, which were important for spliceosome assembly in cells.

High prevalence of high grade squamous intraepithelial lesions and microinvasive carcinoma in women with a cytologic diagnosis of low grade squamous intraepithelial lesions

OBJECTIVE

To evaluate the histologic nature of low grade intraepithelial lesion (LSIL) in a region with a high prevalence of invasive cervical carcinoma and to propose a management protocol.

STUDY DESIGN

Comparing the follow-up of 877 women with LSIL during a 43-month period, taking into consideration the histologic nature determined by colposcopic biopsy, endocervical curettage, conization or hysterectomy as the final pathologic diagnosis.

RESULTS

During the study period, from July 1994 to February 1998, a total of 128,925 Pap smears were performed at our institute, with 877 (0.68%) diagnosed as LSIL. Among these, 722 women with CIN1-SIL and 32 with human papillomavirus-related changes (HPV-SIL) were enrolled in the study. Of the 543 women with CIN 1/squamous intraepithelial lesion, 145 (27%) cases of high grade squamous intraepithelial lesion were disclosed histologically, as were 16 (3%) cases of microinvasion. Among those followed at an interval of three months with a Pap smear alone, the persistence rate was 46.8%, while the regression rate was 40%. Thirty-two women with HPV/SIL underwent histologic evaluation, revealing 18% CIN 2/3 with no microinvasion.

CONCLUSION

A high percentage of CIN 2/3 as well as microinvasive lesions will go unnoticed in the absence of colposcopic evaluation.

Adsorption/desorption properties of copper ions on the surface of iron-coated sand using BET and EDAX analyses

This study was conducted to develop a heating process for coating hydrated iron oxide on the sand surface to utilise the adsorbent properties of the coating and the filtration properties of the sand. BET and scanning electron microscope (SEM) analyses were used to investigate the surface properties of the coated layer. An energy dispersive X-ray (EDAX) technique of analysis was used for characterising metal adsorption sites on the iron-coated sand surface. The results indicated that the iron-coated sand had more micropores and higher specific surface area because of the attachment of iron oxide. Copper ions could penetrate into the micropores and mesopores of iron oxide on sand surface, and the regeneration of the iron-coated sand could be achieved by soaking with pH = 3.0 acid solution. Besides, the results of EDAX analysis showed that copper ions were chemisorbed on the surface of iron-coated sand. Results of the study developed an innovative technology for coating iron oxide on sand surface for the treatment of heavy metal in water.

Comparison of clinical behaviors and responses to radiation between squamous cell carcinomas and adenocarcinomas/adenosquamous carcinomas of the cervix

BACKGROUND

Adenocarcinomas/adenosquamous carcinomas (AC/ASC) are relatively uncommon histological subtypes in cervical cancer. In this study, we retrospectively compared the clinical behaviors and responses to radiation of squamous cell carcinomas (SCC) and AC/ASC in patients with stage I-IVA cervical cancer primarily treated by radiotherapy (RT).

METHODS

Nine hundred twenty-eight patients with cervical cancer primarily treated with RT were included in this study. Ninety-four percent of the patients had SCC and 6% had AC/ASC. The association of histological subtype to various clinical parameters was assessed. Tumor response and failure patterns were analyzed, and the prognostic significance of histological subtype and other clinical parameters were evaluated by univariate and multivariate analyses.

RESULTS

(1) Patients with AC/ASC had a significantly higher percentage of bulky I-IIA disease, a younger age (< 45 years), and an elevated carcinoembryonic antigen (CEA) level, but a lower percentage of elevated squamous cell carcinoma antigen (SCC-Ag) level, than patients with SCC. Hemoglobin (Hb) levels and lymph node status were not significantly different between SCC and AC/ASC patients. (2) A higher percentage of AS/ASC patients had residual induration 2 to 3 months after RT than those with SCC (40% vs. 21.6%, p = 0.008). Higher local failure rates were found for AC/ASC patients compared to SCC patients (38% vs. 15%, p = 0.001). (3) The 5-year disease-specific survival rate was 66% and 50% for SCC and AC/ASC patients, respectively (p = 0.016). Advanced stages, Hb levels lower than 10 g/dl, positive lymph nodes, AC/ASC histological subtype, and SCC-Ag levels higher than 10 ng/ml were independent prognostic factors for worse survival for all patients. For patients with AC/ASC in particular, only stage and positive lymph nodes were significant prognostic factors.

CONCLUSION

Cervical cancer patients with AC/ASC are relatively younger and have a higher incidence of elevated CEA and a lower incidence of elevated SCC-Ag levels than those with SCC. For AC/ASC patients, the tumor responses to RT were relatively slow and poor. This group of patients had a worse survival rate than patients with SCC, mainly because of the higher incidence of uncontrolled local disease for AC/ASC patients.

Competence of Aedes albopictus and Culex quinquefasciatus as vector of Dirofilaria immitis after blood meal with different microfilarial density

Aedes albopictus and Culex quinquefasciatus were fed canine blood with different microfilarial density of Dirofilaria immitis ranging from 2500 to 25,000 mff/ml. Larval development in these two mosquito species did not differ significantly. Although C. quinquefasciatus ingested more microfilariae, the number of larvae which developed in A. albopictus was invariably greater than in C. quinquefasciatus. Mortality of the engorged A. albopictus was significantly greater than that of C. quinquefasciatus, and higher microfilarial density raised the mortality in both species. The vector efficiency index of A. albopictus was greater than C. quinquefasciatus at all microfilarial densities, but its survival time was much reduced. Thus, dogs with low microfilarial density are implicated as the main source for the transmission of D. immitis from dogs to mosquitoes.

Identification of novel human genes evolutionarily conserved in Caenorhabditis elegans by comparative proteomics

Modern biomedical research greatly benefits from large-scale genome-sequencing projects ranging from studies of viruses, bacteria, and yeast to multicellular organisms, like Caenorhabditis elegans. Comparative genomic studies offer a vast array of prospects for identification and functional annotation of human ortholog genes. We presented a novel comparative proteomic approach for assembling human gene contigs and assisting gene discovery. The C. elegans proteome was used as an alignment template to assist in novel human gene identification from human EST nucleotide databases. Among the available 18,452 C. elegans protein sequences, our results indicate that at least 83% (15,344 sequences) of C. elegans proteome has human homologous genes, with 7,954 records of C. elegans proteins matching known human gene transcripts. Only 11% or less of C. elegans proteome contains nematode-specific genes. We found that the remaining 7,390 sequences might lead to discoveries of novel human genes, and over 150 putative full-length human gene transcripts were assembled upon further database analyses. [The sequence data described in this paper have been submitted to the

High-risk HPV DNA detection by Hybrid Capture II. An adjunctive test for mildly abnormal cytologic smears in women > or = 50 years of age

OBJECTIVE

To determine whether high-risk human papillomavirus (HPV) DNA testing could improve the detection of cervical intraepithelial neoplasia (CIN) and cancer in older women (> or = 50 years old) with mildly abnormal results on conventional cytology.

STUDY DESIGN

The study was based on 119 patients aged over 50 (median, 62; range, 50-78) referred for colposcopy with Pap smears reported as atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesion (LSIL) from February 1997 to September 1998. The presence of high-risk HPV DNA (including HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68) was determined with the Hybrid Capture II (Digene, Inc., Silver Spring, Maryland) microplate method. Cytologic examination by Pap smear was based on the Bethesda System and, cervical biopsy was done via colposcopy.

RESULTS

High-risk HPV DNA was demonstrated in 75.6% (34/45) of patients with LSIL and 52.7% (39/74) with ASCUS. Those who were HPV positive were significantly more likely to have CIN or cancer (odds ratio, 33.40; 95% confidence interval, 11.89-93.97; P < .0001). The sensitivity of HPV assay for detection of lesions more severe than CIN 2 was 100%, specificity 64.8%, positive predictive value 66.7% and negative predictive value 100%.

CONCLUSION

The addition of a high-risk HPV DNA assay to cytologic examination appears to provide excellent sensitivity and negative predictive value for early detection of high grade CIN or cancer in older women with minimally abnormal Pap smears.

Randomized trial of neoadjuvant cisplatin, vincristine, bleomycin, and radical hysterectomy versus radiation therapy for bulky stage IB and IIA cervical cancer

PURPOSE

To compare the efficacy of neoadjuvant chemotherapy (NAC) followed by radical hysterectomy with that of radiotherapy (R/T) for bulky early-stage cervical cancer.

PATIENTS AND METHODS

Women with previously untreated bulky (primary tumor >/= 4 cm) stage IB or IIA non-small-cell carcinoma of the uterine cervix were randomly assigned to receive either cisplatin 50 mg/m(2) and vincristine 1 mg/m(2) for 1 day and bleomycin 25 mg/m(2) for 3 days for three cycles followed by radical hysterectomy (NAC arm) or receive primary pelvic radiotherapy only (R/T arm). The ratio of patient allocation was 6:4 for the NAC and R/T arms. Women with enlarged para-aortic lymph nodes on image study were ineligible unless results of cytologic or histologic studies were negative.

RESULTS

Of the 124 eligible patients, 68 in the NAC arm and 52 in the R/T arm could be evaluated. The median duration of follow-up was 39 months. Thirty-one percent of patients in the NAC arm and 27% in the R/T arm had relapse or persistent diseases after treatment, and 21% in each group died of disease. Estimated cumulative survival rates at 2 years were 81% for the NAC arm and 84% for the R/T arm; the 5-year rates were 70% and 61%, respectively. There were no significant differences in disease-free survival and overall survival.

CONCLUSION

NAC followed by radical hysterectomy and primary R/T showed similar efficacy for bulky stage IB or IIA cervical cancer. Further study to identify patient subgroups better suited for either treatment modality and to evaluate the concurrent use of cisplatin and radiation without routine hysterectomy is necessary.

Heterobimetallics of nickel-iron dinitrosyl: electronic control by chelate and diatomic ligands

Reaction of [PPN][Fe(NO)2(SePh)2] (1) with dimeric [Ni(mu-SCH2CH2SCH2CH2S)]2 in the presence of additional NO2- produced the neutral heterobimetallic [(ON)Ni[(mu-SCH2CH2)2S]Fe(NO)2] complex (2). The X-ray crystal structures of 1 and 2 show distorted tetrahedral iron dinitrosyl groups, assigned according to the Feltham-Enemark notation as [Fe(NO)2]9 The Fe-NO bonds are off linearity by an average of approximately equals 10 degrees for compounds 1 and 2, while a more linear Ni-NO coordination with a Ni-NO distance of 1.644(2) A was found in 2. The v(NO) value of complex 2 is consistent with an assignment for [Ni(NO)]9 of Ni0(NO)+ as is known for analogous phosphine derivatives, P3Ni0(NO)+. EPR signals of g values = 2.02-2.03 confirmed the existence of the odd electron in the chalcogenated [Fe(NO)2]9 compounds. Two [Fe(NO)2]10 complexes coordinated by the nickel(II) dithiolate, (bismercaptoethanediazacyclooctane)nickel(II), (Ni-1), (Ni-1)Fe(CO)(NO)2 and (Ni-1)Fe(NO)2, were prepared for comparison to the Ni0(NO)+ derivative and other monomeric and homodimetallic derivatives of the Fe(NO)2 fragment. While the oxidation level of Fe(NO)2 is the primary determinant of v(NO) values, they are also highly sensitive to ancillary ligands and, thereby, the distal metal influence through the bridging thiolate donor.

Successful treatment of recurrent pelvic desmoid tumour with tamoxifen: case report

The case report of a young woman with recurrent pelvic desmoid tumour successfully treated with tamoxifen is described. The desmoid tumour recurred within 6 months after the initial exploratory laparotomy. Tamoxifen therapy led to complete relief of ascites within 2 months and complete tumour regression by the end of the fourth month, and the patient has remained stable for 6 years. Without sacrificing pelvic organs or major vessels and preserving reproductive ability, tamoxifen should be considered as the first drug of choice in such a recurrent condition.

Neuronal response sensitivity to bidirectional off-vertical axis rotations: a dimension of imbalance in the bilateral vestibular nuclei of cats after unilateral labyrinthectomy

In decerebrate cats after acute hemilabyrinthectomy, the response sensitivity of extracellularly recorded vestibular nuclear neurons on the lesioned and labyrinth-intact sides were examined quantitatively during constant velocity off-vertical axis rotations with an aim to elucidate the functional contribution of otolithic inputs to the ipsilateral and contralateral vestibular nuclei. The bidirectional response sensitivity, delta, was determined as the ratio of the gain during clockwise to that during counterclockwise rotations. A continuum of response sensitivity was identified: one-dimensional neurons showed symmetrically bidirectional response patterns, while two-dimensional neurons showed asymmetrically bidirectional patterns that in some cases approached unidirectional patterns with change in velocity. The proportion of two-dimensional neurons was significantly increased after acute hemilabyrinthectomy. Two-dimensional neurons that responded only to one direction of rotation in at least one of the velocities tested were described as unidirectional neurons. This unidirectional response pattern was observed in one-third of the entire neuronal population studied, but not in cats with both labyrinths intact, thus suggesting that such prominent broadly tuned responses are normally masked by converging otolithic inputs from the contralateral side. These neurons were found in higher proportion on the lesioned side than on the labyrinth-intact side. Among the 70% of unidirectional neurons that exhibited bidirectional response at some velocities and unidirectional response at others, prominent shifts in delta values (i.e. between 0/infinity and finite values) with velocity can be computed for each neuron. The shifts in delta values correlated with large shifts in the response dynamics and spatial orientation as the response pattern changed with velocity. The response orientations of the unidirectional neurons pointed in all directions on the horizontal plane. When all the two-dimensional neurons (i.e. both the unidirectionally and bidirectionally responsive ones) were pooled, imbalances in the distribution of the response orientations and in response gain were found between the ipsilateral-side-down/head-down half-circle and the contralateral-side-down/head-up half-circle on the labyrinth-intact side, but not on the lesioned side. These results, derived from spatiotemporal processing of gravitational signals, reveal a novel dimension of imbalance between neuronal populations in the two vestibular nuclear complexes after acute lesion of one labyrinth. This feature would provide, on the one hand, deranged cues of spatial orientation and direction during slow head excursions and, on the other, a framework for the dynamic behavioral deficits associated with hemilabyrinthectomy.

Radical resection and intraoperative radiotherapy for a recurrent endometrial cancer after prolonged remission following aggressive salvage therapy: case report

The prognosis of recurrent endometrial carcinomas is generally poor, except for isolated vaginal relapse. We report a case of recurrent endometrial cancer in a 58-year-old woman who initially received a type I extended hysterectomy with bilateral salpin-go-oophorectomy and bilateral para-aortic and pelvic lymph node dissection. The first recurrence occurred in the left parametrium 7 months after the primary surgery. The salvage therapy consisted of radiotherapy combined with hormonal therapy (tamoxifen and Megace). Complete remission was achieved initially. Subsequently, the patient accepted six courses of chemotherapy (cisplatin and Adriamycin) for progressive elevation of cancer antigen 125 (CA-125). The CA-125 levels remained elevated with titers fluctuating around 100 U/ml until a second recurrence at the left iliac 75 months following salvage therapy. The second salvage treatment consisted of maximal debulking of the pelvic mass and intraoperative radiotherapy (IORT) followed by four courses of chemotherapy with paclitaxel and carboplatin. Complete remission was again accomplished, with clinical investigations and molecular markers returning to normal. The patient has been clinically free of disease for more than 2 years since the second relapse of cancer. In this particular case, we found that repeated recurrence could occur after a long complete remission following salvage therapy; however, the disease could be recontrolled with further aggressive salvage efforts. A multimodality approach with combinations of radical resection, IORT, and paclitaxel-based chemotherapy can be offered to patients with localized recurrent or repeatedly recurrent endometrial carcinoma after previous cisplatin-based chemotherapy and pelvic radiation.

The prognostic factors for patients with early cervical cancer treated by radical hysterectomy and postoperative radiotherapy

PURPOSE

This study was undertaken to evaluate the efficacy of postoperative radiotherapy (post-OP RT) and to investigate the prognostic factors for early-stage cervical cancer patients who were treated by radical surgery, and the pathological findings suggested a relatively high risk of relapse with surgery alone.

MATERIALS AND METHODS

From January 1990 to December 1995, 222 patients with stage IB-IIA cervical cancer, treated by radical surgery and a full course of post-OP RT, were included in this study. The indications for post-OP RT were based on pathological findings, including lymph node metastasis, positive surgical margins, parametrial extension, lymphovascular permeation, and invasion of more than two-thirds of the cervical wall thickness. The radiation dose of external beam was 44-45 Gy to the whole pelvis and 50-54 Gy to the true pelvis. One hundred seventy-two patients also received intravaginal brachytherapy as a local boost. The minimal follow-up period was 2 years.

RESULTS

The actuarial 5-year overall and disease-specific survival rates for all patients were 76 and 82%, respectively. The tumor control rate within the pelvis reached 94%, and distant metastasis was the major cause of treatment failure. Univariate analysis of clinical and pathological parameters revealed that clinical stage, bulky tumor size, positive lymph nodes, parametrial extension, and histologic type were significant prognostic factors. After multivariate analysis, only positive lymph nodes (P = 0.01), bulky tumor size (P = 0.02), and parametrial extension (P = 0.05) independently influenced the disease-specific survival (DSS). For patients with lymph node metastasis, the number and location of the nodal involvement significantly affected the prognosis. The 5-year DSS for patients with no, one, and more than one lymph node metastasis were 87, 84, and 61% (P = 0.0001), respectively. Patients with upper pelvic lymph node metastasis had a higher incidence of distant metastasis (50% vs 16% in lower pelvic node group, P = 0.03). In the subgroup of single lower pelvic nodal metastasis, the prognosis was similar to that of patients without lymph node involvement (5-year DSS 85% vs 87%, P = 0.71).

CONCLUSION

Our results indicate that post-OP RT can achieve very good local control in stage IB-IIA cervical cancer patients whose pathological findings show risk features for relapse after radical surgery. The prognostic factors for treatment failure identified in this study can be used as selection criteria for clinical trials to test the effects of other adjuvant treatments, such as chemotherapy. Patients with a single lower pelvic lymph node metastasis have a relatively good prognosis and may not need adjuvant treatment beyond radiation therapy.

Identification and gene structure of a novel human PLZF-related transcription factor gene, TZFP

A novel cDNA clone was identified through yeast two-hybrid experiments. Following cross-examination between the cDNA clones, EST clones, and the cosmid clone, we could digitally assemble a new zinc finger transcription factor gene. This predicted gene has a cDNA size of about 1960 bp and is translated into a 487-amino-acid protein. According to database analysis, this gene contains three C2H2 zinc finger motifs and is highly related to human PLZF (promyelocytic leukemia zinc finger protein). The full-length coding region of the gene was isolated, and its sequences were confirmed by DNA sequencing. Interestingly, one splicing variant lacking exon III was also identified. Northern blot analysis revealed that this gene is mainly expressed in human testis. In conclusion, we have identified a new member of the PLZF zinc finger protein family, the testis zinc finger protein (TZFP), which is mainly expressed in testis tissue.

Improvement of the local prediction of chaotic time series

In this paper we explore the effect of pseudofalse neighbor points, which are true neighbor points in the reconstructed attractor, but which are considered not suitable to be used when local methods are adopted to predict the chaotic time series. In our approach, the epsilon(p) neighbor points are used to reduce the influence of the pseudofalse neighbor points, thereby improving the performance of the local prediction of the chaotic time series.

Amplification of weak signals and stochastic resonance via on-off intermittency with symmetry breaking

Nonlinear dynamical systems possessing reflection symmetry have an invariant subspace in the phase space. The dynamics within the invariant subspace can be random or chaotic. As a system parameter changes, the motion transverse to the invariant subspace can lose stability, leading to on-off intermittency. Under certain conditions, the bursting behavior is symmetry breaking. We demonstrate the possibility of observing multiplicative noise(chaos)-induced amplification of weak signal and stochastic resonance via on-off intermittency with symmetry breaking in a general class of symmetrical systems. Differences of this mechanism of stochastic resonance to that in noisy bistable or threshold systems are discussed.

Recurrent cervical carcinoma after primary radical surgery

OBJECTIVE

This study was undertaken to investigate prognostic factors in patients with recurrent cervical carcinoma who had undergone a primary radical hysterectomy and pelvic lymphadenectomy.

STUDY DESIGN

A retrospective analysis of 177 patients with recurrent cervical carcinoma after radical hysterectomy and pelvic lymphadenectomy for stage IB to II disease at a single institution was performed to evaluate clinicopathologic parameters, time to recurrence, pattern of failure, use of salvage therapy, and survival after recurrence.

RESULTS

The 5-year survival rate from diagnosis of recurrence in this series was 10.1%. Survival after recurrence was significantly decreased in patients with pelvic lymph node metastasis at primary surgery and adenocarcinoma-adenosquamous carcinoma histologic type. Patients with extravaginal recurrences receiving chemoradiation for recurrent cervical carcinoma had significantly better outcomes than those receiving radiation alone. Six patients who had a distant relapse at a sole site had prolonged survival after salvage therapy, which was accomplished by chemoradiation, surgery plus radiotherapy, or surgery alone.

CONCLUSIONS

Our results demonstrate the benefit of adding chemotherapy to radiotherapy in the treatment of recurrent cervical carcinoma. Salvage multimodality treatment should be offered to selected patients who have isolated relapse at a single distant site.

Phase II trial of neoadjuvant chemotherapy in early-stage small cell cervical cancer

Clinical complete response (CR) to chemotherapy is not uncommon in small cell carcinoma. To understand its pathologic response, we conducted a phase II trial with neoadjuvant chemotherapy followed by hysterectomy in patients with small cell cervical cancer and reviewed all reported cases receiving neoadjuvant chemotherapy followed by hysterectomy through a MEDLINE search. From December 1993 to December 1997, the enrolled patients were treated with two to three courses of vincristine, adriamycin and cyclophosphamide alternating with cisplatin and etoposide (VAC/PE) before hysterectomy. Another three courses of chemotherapy were added after surgery. A total of seven patients was enrolled. Clinical CR was observed in six patients, but microscopic residual tumor was present in all. Lymphatic permeation, scattered residual tumor clusters and residual superficial invasive adenocarcinoma over the cervix presented in five cases, and another had a metastatic pelvic node with no residual cervical tumor. Three of these seven patients have been alive with no evidence of disease for 16.2, 45.2 and 56.6 months, respectively. The other four died from disease 10.3-23.6 months after diagnosis. These findings indicate the discrepancy between clinical and pathologic responses in small cell cervical cancer after chemotherapy and emphasize the necessity of local treatment.

Extracting messages masked by chaotic signals of time-delay systems

We show how to extract messages masked by a chaotic signal of a time-delay system with very high dimensions and many positive Lyapunov exponents. Using a special embedding coordinate, the infinite-dimensional phase space of the time-delay system is projected onto a special three-dimensional space, which enables us to identify the time delay of the system from the transmitted signal and reconstruct the chaotic dynamics to unmask the hidden message successfully. The message extraction procedure is illustrated by simulations with the Mackey-Glass time-delay system for two types of masking schemes and different kinds of messages.

Decoding information by following parameter modulation with parameter adaptive control

It has been proposed to realize secure communication using chaotic synchronization via transmission of a binary message encoded by parameter modulation in the chaotic system. This paper considers the use of parameter adaptive control techniques to extract the message, based on the assumptions that we know the equation form of the chaotic system in the transmitter but do not have access to the precise values of the parameters which are kept secret as a secure set. In the case in which a synchronizing system can be constructed using parameter adaptive control by the transmitted signal and the synchronization is robust to parameter mismatches, the parameter modulation can be revealed and the message decoded without resorting to exact parameter values in the secure set. A practical local Lyapunov function method for designing parameter adaptive control rules based on originally synchronized systems is presented.