The complex polyploid genome architecture of sugarcane

Sugarcane, the world's most harvested crop by tonnage, has shaped global history, trade and geopolitics, and is currently responsible for 80% of sugar production worldwide1. While traditional sugarcane breeding methods have effectively generated cultivars adapted to new environments and pathogens, sugar yield improvements have recently plateaued2. The cessation of yield gains may be due to limited genetic diversity within breeding populations, long breeding cycles and the complexity of its genome, the latter preventing breeders from taking advantage of the recent explosion of whole-genome sequencing that has benefited many other crops. Thus, modern sugarcane hybrids are the last remaining major crop without a reference-quality genome. Here we take a major step towards advancing sugarcane biotechnology by generating a polyploid reference genome for R570, a typical modern cultivar derived from interspecific hybridization between the domesticated species (Saccharum officinarum) and the wild species (Saccharum spontaneum). In contrast to the existing single haplotype ('monoploid') representation of R570, our 8.7 billion base assembly contains a complete representation of unique DNA sequences across the approximately 12 chromosome copies in this polyploid genome. Using this highly contiguous genome assembly, we filled a previously unsized gap within an R570 physical genetic map to describe the likely causal genes underlying the single-copy Bru1 brown rust resistance locus. This polyploid genome assembly with fine-grain descriptions of genome architecture and molecular targets for biotechnology will help accelerate molecular and transgenic breeding and adaptation of sugarcane to future environmental conditions.

Combination of Proactive Molecular Risk Classifier for Endometrial cancer (ProMisE) with sonographic and demographic characteristics in preoperative prediction of recurrence or progression of endometrial cancer

OBJECTIVE

To evaluate the ability of demographic and sonographic variables and the Proactive Molecular Risk Classifier for Endometrial cancer (ProMisE) classification to predict preoperatively tumor recurrence or progression in women with endometrial cancer.

METHODS

The study included 339 women with histologically confirmed endometrial cancer who underwent expert transvaginal ultrasound in a single center before surgery as part of the prospective International Endometrial Tumor Analysis 4 study or who were evaluated using the same protocol. The tumors were classified according to histotype, FIGO (International Federation of Gynecology and Obstetrics) grade and FIGO stage. In addition, molecular analysis was performed for classification into the four ProMisE subtypes: polymerase-ϵ exonuclease domain mutations (POLE EDM), mismatch repair proteins deficiency (MMR-D), protein 53 wild type (p53 wt) and protein 53 abnormal (p53 abn). Demographic and preoperative sonographic characteristics, tumor recurrence or progression and survival were compared between the ProMisE subgroups. Cox regression analysis was used to identify prognostic factors associated with recurrence or progression, using univariable models to study crude associations and multivariable models to study adjusted associations. Logistic regression and receiver-operating-characteristics (ROC)-curve analysis were used to assess the predictive ability of the preoperative prognostic factors regarding recurrence or progression of cancer within 3 years after surgery, and to compare their predictive ability to that of the European Society for Medical Oncology (ESMO) preoperative (based on depth of myometrial invasion, histotype and grade) and postoperative (based on histotype, grade, surgical stage and lymphovascular space invasion) risk classifications. In a separate subanalysis, cases were stratified according to ProMisE p53 abn status (present vs absent) and sonographic tumor size (anteroposterior (AP) diameter < 2 cm vs ≥ 2 cm).

RESULTS

Median follow-up time from surgery was 58 months (interquartile range, 48-71 months; range, 0-102 months). Recurrence or progression of cancer occurred in 51/339 (15%) women, comprising 14% of those with MMR-D, 8% of those with POLE EDM, 9% of those with p53 wt and 45% of those with p53 abn ProMisE subtype. On multivariable analysis, age, waist circumference, ProMisE subtype and tumor extension and AP diameter on ultrasound were associated with tumor recurrence or progression. A multivariable model comprising ProMisE subtype, age, waist circumference and sonographic tumor extension and size (area under the ROC curve (AUC), 0.89 (95% CI, 0.85-0.93)) had comparable ability to predict tumor recurrence/progression to that of a multivariable model comprising histotype, grade, age, waist circumference and sonographic tumor extension and size (AUC, 0.88 (95% CI, 0.83-0.92)), and better predictive ability than both the preoperative (AUC, 0.74 (95% CI, 0.67-0.82); P < 0.01) and postoperative (AUC, 0.79 (95% CI, 0.72-0.86); P < 0.01) ESMO risk classifications. Women with a combination of non-p53 abn subtype and tumor size < 2 cm (164/339 (48%)) had a very low risk (1.8%) of tumor recurrence or progression.

CONCLUSIONS

The combination of demographic characteristics, sonographic findings and ProMisE subtype had better preoperative predictive ability for tumor recurrence or progression than did the ESMO classification, supporting their use in the preoperative risk stratification of women with endometrial cancer. The combination of p53 status with ultrasound tumor size has the potential to identify preoperatively a large group of women with a very low risk of recurrence or progression. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. - Legal Statement: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Validation of ultrasound strategies to assess tumor extension and to predict high-risk endometrial cancer in women from the prospective IETA (International Endometrial Tumor Analysis)-4 cohort

OBJECTIVES

To compare the performance of ultrasound measurements and subjective ultrasound assessment (SA) in detecting deep myometrial invasion (MI) and cervical stromal invasion (CSI) in women with endometrial cancer, overall and according to whether they had low- or high-grade disease separately, and to validate published measurement cut-offs and prediction models to identify MI, CSI and high-risk disease (Grade-3 endometrioid or non-endometrioid cancer and/or deep MI and/or CSI).

METHODS

The study comprised 1538 patients with endometrial cancer from the International Endometrial Tumor Analysis (IETA)-4 prospective multicenter study, who underwent standardized expert transvaginal ultrasound examination. SA and ultrasound measurements were used to predict deep MI and CSI. We assessed the diagnostic accuracy of the tumor/uterine anteroposterior (AP) diameter ratio for detecting deep MI and that of the distance from the lower margin of the tumor to the outer cervical os (Dist-OCO) for detecting CSI. We also validated two two-step strategies for the prediction of high-risk cancer; in the first step, biopsy-confirmed Grade-3 endometrioid or mucinous or non-endometrioid cancers were classified as high-risk cancer, while the second step encompassed the application of a mathematical model to classify the remaining tumors. The 'subjective prediction model' included biopsy grade (Grade 1 vs Grade 2) and subjective assessment of deep MI or CSI (presence or absence) as variables, while the 'objective prediction model' included biopsy grade (Grade 1 vs Grade 2) and minimal tumor-free margin. The predictive performance of the two two-step strategies was compared with that of simply classifying patients as high risk if either deep MI or CSI was suspected based on SA or if biopsy showed Grade-3 endometrioid or mucinous or non-endometrioid histotype (i.e. combining SA with biopsy grade). Histological assessment from hysterectomy was considered the reference standard.

RESULTS

In 1275 patients with measurable lesions, the sensitivity and specificity of SA for detecting deep MI was 70% and 80%, respectively, in patients with a Grade-1 or -2 endometrioid or mucinous tumor vs 76% and 64% in patients with a Grade-3 endometrioid or mucinous or a non-endometrioid tumor. The corresponding values for the detection of CSI were 51% and 94% vs 50% and 91%. Tumor AP diameter and tumor/uterine AP diameter ratio showed the best performance for predicting deep MI (area under the receiver-operating characteristics curve (AUC) of 0.76 and 0.77, respectively), and Dist-OCO had the best performance for predicting CSI (AUC, 0.72). The proportion of patients classified correctly as having high-risk cancer was 80% when simply combining SA with biopsy grade vs 80% and 74% when using the subjective and objective two-step strategies, respectively. The subjective and objective models had an AUC of 0.76 and 0.75, respectively, when applied to Grade-1 and -2 endometrioid tumors.

CONCLUSIONS

In the hands of experienced ultrasound examiners, SA was superior to ultrasound measurements for the prediction of deep MI and CSI of endometrial cancer, especially in patients with a Grade-1 or -2 tumor. The mathematical models for the prediction of high-risk cancer performed as expected. The best strategies for predicting high-risk endometrial cancer were combining SA with biopsy grade and the subjective two-step strategy, both having an accuracy of 80%. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Ultrasound characteristics of endometrial cancer as defined by International Endometrial Tumor Analysis (IETA) consensus nomenclature: prospective multicenter study

OBJECTIVE

To describe the sonographic features of endometrial cancer in relation to tumor stage, grade and histological type, using the International Endometrial Tumor Analysis (IETA) terminology.

METHODS

This was a prospective multicenter study of 1714 women with biopsy-confirmed endometrial cancer undergoing standardized transvaginal grayscale and Doppler ultrasound examination according to the IETA study protocol, by experienced ultrasound examiners using high-end ultrasound equipment. Clinical and sonographic data were entered into a web-based database. We assessed how strongly sonographic characteristics, according to IETA, were associated with outcome at hysterectomy, i.e. tumor stage, grade and histological type, using univariable logistic regression and the c-statistic.

RESULTS

In total, 1538 women were included in the final analysis. Median age was 65 (range, 27-98) years, median body mass index was 28.4 (range 16-67) kg/m² , 1377 (89.5%) women were postmenopausal and 1296 (84.3%) reported abnormal vaginal bleeding. Grayscale and color Doppler features varied according to grade and stage of tumor. High-risk tumors, compared with low-risk tumors, were less likely to have regular endometrial-myometrial junction (difference of -23%; 95% CI, -27 to -18%), were larger (mean endometrial thickness; difference of +9%; 95% CI, +8 to +11%), and were more likely to have non-uniform echogenicity (difference of +7%; 95% CI, +1 to +13%), a multiple, multifocal vessel pattern (difference of +21%; 95% CI, +16 to +26%) and a moderate or high color score (difference of +22%; 95% CI, +18 to +27%).

CONCLUSION

Grayscale and color Doppler sonographic features are associated with grade and stage of tumor, and differ between high- and low-risk endometrial cancer. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Abstract P1-07-07: Gene expression signatures and immunohistochemical subtypes add prognostic value to each other

Background: We have previously demonstrated that gene expression signatures and Ki67 stratify the same breast tumour into opposing good/poor prognosis groups in approximately 20% of cases. Given this, we hypothesized that the combination of a clinically relevant gene signature and IHC markers may provide more prognostic information than either classifier alone. We tested this hypothesis in a large independent cohort of Swedish breast cancer patients with long-term follow-up data.

Methods: We assessed Ki67, ER, PR, HER2 and the research versions of the Genomic Grade Index (GGI), Mammaprint, cell-cycle score (CCS), Recurrence Score (RS) and PAM50 gene expression classifiers on matching TMA and microarray data in a Swedish breast cancer cohort of 623 patients. Change in likelihood-ratio (Δ LR-χ2) was used to first determine the additional prognostic information provided by gene expression signatures beyond that provided by 1) Ki67 alone and 2) Ki67 plus ER, PR and HER2, grouped to form the IHC molecular subtypes. Secondly and conversely, we then determined the additional prognostic information provided by Ki67/IHC subtypes beyond gene expression signatures.

Results: Representative images from Ki67/gene signature contrast groups show tumours with high levels of Ki67 expression that are classified as good prognosis by gene signatures and conversely, tumours with low Ki67 that are classified into poor prognosis groups by gene signatures. In all patients (n=623), the majority of signatures provided statistically significant information beyond that of Ki67 alone, however only RS and PAM50 remained significant in the presence of the IHC subtypes (Δ LR-χ2 RS= 11.7 and PAM50 = 15.4; P = 0.002 and 0.004, respectively). Conversely, IHC subtypes added prognostic information beyond gene signatures whilst Ki67 alone did not, a notable exception to this was PAM50.

Conclusions: In general, a combination of the IHC subtypes with gene signatures provides more prognostic information than either classifier alone when considering all breast cancer patients. Subsequent analyses will focus on patient subgroups including ER positive, node positive and ER positive, node negative groups, along with validation of our work in a second dataset of 253 patients.

Change in likelhood ratio with the addition of gene expression signatures to Ki67/IHC subgroups and vice-versa All Patients All PatientsSig. added to Ki67:Sig. Δ LRχ2P-valueSig. added to IHC subtypesSig. Δ LRχ2P-valueGGI6.00.014GGI2.50.108Mammaprint6.30.011Mammaprint1.10.279RS20.8&lt; 0.001RS11.70.002CCS1.70.409CCS2.00.360PAM5025.0&lt; 0.001PAM5015.40.004      Ki67 added to sig.:Ki67 Δ LRχ2P-valueIHC added to sig.:IHC Δ LRχ2P-valueGGI1.60.205GGI14.90.001Mammaprint1.60.199Mammaprint15.30.001RS0.50.477RS12.60.005CCS4.10.041CCS16.10.001PAM502.30.13PAM506.10.107Sig.: Gene expression signature; GGI: Genomic grade index; RS: Recurrence score; CCS: Cell cycle score.

Citation Format: Lundberg A, Lindström LS, Falato C, Carlson JW, Foukakis T, Czene K, Bergh J, Tobin NP. Gene expression signatures and immunohistochemical subtypes add prognostic value to each other [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-07-07.

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Endometrial intraepithelial neoplasia is associated with polyps and frequently has metaplastic change

AIMS

Endometrial intraepithelial neoplasia (EIN) is a monoclonal precursor to endometrioid endometrial adenocarcinoma characterized by a geographic cluster of crowded glands with epithelial cytology altered relative to the background. It may demonstrate epithelial metaplastic changes, or arise within polyps, but the frequencies of these features as encountered in practice is unknown. The aim was to report the epithelial differentiation state and polyp context of 83 sequential EIN lesions diagnosed over a 2-year period.

METHODS AND RESULTS

EIN is a rare lesion, seen in only 1.4% of endometrial biopsy specimens in a busy hospital-based practice. Of 83 EIN cases, 39 contained metaplastic changes (18% squamous morular, 14% tubal secretory and 5% each of secretory, mucinous or ciliated change). Endometrial polyps were more likely (odds ratio 5.2, P < 0.001) to occur in the endometrial biopsy specimens of women with EIN lesions (43.3%), compared with the background polyp rate (12.9%) of comparable specimens from the same patient population.

CONCLUSIONS

Non-endometrioid differentiation and occurrence within polyps are frequent presentations of EIN lesions. Possible mechanisms of polyp association with EIN include: non-shedding of polyp tissue creating a shelter for persistence of pre-existing neoplastic glands, or promotion of premalignant glandular clones by unique polyp stroma.

Biomarker-assisted diagnosis of ovarian, cervical and pulmonary small cell carcinomas: the role of TTF-1, WT-1 and HPV analysis

AIMS

Small cell carcinoma of the ovary, hypercalcaemic-type (SCCOH) is morphologically similar to small cell carcinomas from other sites. The aims of this study were to (i) determine if a biomarker panel would distinguish small cell carcinomas of the ovary, cervix (SCCCx) and lung (SCCLu) and (ii) potentially determine the histogenesis of SCCOH.

METHODS AND RESULTS

Nine ovarian small cell carcinomas (seven hypercalcaemic type; two pulmonary type), eight SCCCx and 22 SCCLu were immunostained for thyroid transcription factor (TTF)-1, WT-1, p16, cKIT and OCT3/4; a subset of cases were tested for human papillomavirus (HPV). WT-1 was diffusely positive in 6/7 SSCOH versus two of 33 other small cell carcinomas (P <or= 0.001). TTF-1 was diffusely positive in 20/22 SCCLu and 1/8 SCCCx, and negative in all SCCOH. p16 and cKIT demonstrated variable patterns of immunoreactivity in all cases. HPV was identified in 5/6 SCCCx; SCCOH and SCCLu were negative for HPV.

CONCLUSIONS

Combined staining with WT-1 and TTF-1 will distinguish SCCOH from SCCLu and SCCCx with a sensitivity of 86% and specificity of 97%. HPV is specific for tumours of cervical origin, but p16 immunohistochemistry is not useful for this purpose. The presence of diffuse WT-1 supports a Müllerian origin for SCCOH, whereas the absence of cKIT and OCT3/4 argues against a germ cell origin.

Immunohistochemistry for beta-catenin in the differential diagnosis of spindle cell lesions: analysis of a series and review of the literature

AIMS

Nuclear staining for beta-catenin by immunohistochemistry is being used increasingly to diagnose desmoid tumours (deep fibromatoses), especially where the differential diagnosis includes other abdominal spindle cell neoplasms. This study aimed to define the prevalence of beta-catenin positivity in desmoid tumours and other morphologically similar spindle cell neoplasms.

METHOD AND RESULTS

Nuclear beta-catenin expression was evaluated by immunohistochemistry in 270 soft tissue tumours. Nuclear immunopositivity was detected in 80% of cases of sporadic desmoid fibromatosis (24/30) and in 67% of tumours in patients with familial adenomatous polyposis (8/12). Nuclear positivity was also present in 14/25 superficial fibromatoses (56%), 3/10 low-grade myofibroblastic sarcomas (30%), 5/23 solitary fibrous tumours (22%), 1/5 infantile fibrosarcomas (20%), 1/18 desmoplastic fibroblastomas (6%) and 1/21 gastrointestinal stromal tumours (5%). No nuclear immunoreactivity was present in neurofibromas (0/26), schwannomas (0/25), nodular fasciitis (0/19), leiomyosarcomas (0/16), inflammatory myofibroblastic tumours (0/12), fibromas of tendon sheath (0/9), lipofibromatoses (0/5), Gardner fibromas (0/4), calcifying aponeurotic fibromas (0/4) or fibromatosis colli (0/1).

CONCLUSION

Nuclear staining for beta-catenin is supportive, but not definitive, of the diagnosis of desmoid fibromatosis. No significant difference in immunoreactivity was observed between sporadic and familial desmoid fibromatoses. beta-Catenin negativity does not preclude the diagnosis of fibromatosis.

Efficacy of treatment of inflammatory cytologic abnormalities detected by papanicolaou smears: a pilot study

OBJECTIVE

To evaluate the efficacy of metronidazole versus no treatment for the empiric treatment of inflammatory cytologic changes.

MATERIALS AND METHODS

Patients with inflammatory changes on Pap smear were serially assigned to receive no treatment or metronidazole by one of three regimens: 2 grams orally as a single dose, 500 milligrams orally twice daily for 7 days, or 5 grams (in gel form) vaginally twice daily for 5 days. Smears were repeated 3 months after treatment.

RESULTS

The repeat smear was normal in 47 of 63 patients treated with a single dose, 40 of 62 patients treated orally for 7 days, 14 of 21 patients treated with vaginal gel, and 29 of 49 of the control group. Chi-square analysis showed no statistical significance between groups.

CONCLUSION

There is no statistically significant difference in the resolution of cytologic inflammatory changes among the study groups. Empiric metronidazole treatment has no benefit.

Cervical adenocarcinoma in situ: a systematic review of therapeutic options and predictors of persistent or recurrent disease

The incidence of cervical adenocarcinoma in situ is increasing in frequency, and our limited knowledge about this lesion presents the physician with a therapeutic dilemma. Treatment for this lesion has included conservative therapy, large loop excision or cold-knife cone biopsy, or definitive therapy consisting of hysterectomy. But, rates of residual adenocarcinoma in situ after cone biopsy with negative margins vary from 0% to 40%, and residual disease rates as high as 80% have been noted when the margins are positive. Despite these recent data on follow-up after conservative therapy such as cone biopsy, it seems that this method is safe and gaining acceptance by many physicians and patients. However, the short follow-up duration and small number of patients limit the conclusions of many studies. The relative infrequency of this diagnosis has precluded extensive clinical experience with the natural history of this lesion.

Abnormal fragile histidine triad (FHIT) expression in advanced cervical carcinoma: a poor prognostic factor

The FHIT gene is a candidate tumor suppressor gene that has been implicated in the development of cervical carcinoma. We hypothesized that abnormal Fhit expression might be a poor prognostic factor for patients with cervical cancer. The tumors from 59 high-risk patients (stage II-III) were evaluated for abnormal Fhit expression by immunohistochemical staining. Abnormal Fhit expression (absent or reduced) was noted in 66% of the specimens. There was no statistical difference with respect to stage, performance status, para-aortic node metastasis, completion of therapy, grade, race, age, and HIV status between the normal and abnormal Fhit expression groups. The 3-year survival for patients whose tumors displayed normal Fhit expression versus abnormal Fhit expression was 74% versus 37%, respectively. Univariate analysis demonstrated a difference in survival that was statistically significant for age <55 years versus > or =55 years (P = 0.015), normal Fhit expression versus abnormal Fhit expression (P = 0.015), and stage II versus stage III (P = 0.033). Multivariate analysis showed that abnormal Fhit expression was a poor prognostic factor (P = 0.015).

Equal care ensures equal survival for African-American women with cervical carcinoma

BACKGROUND

[corrected] It was the purpose of this study to investigate whether race is an independent prognostic factor in the survival of patients with cervical carcinoma in a health care system with minimal racial bias, and few barriers to access to care.

METHODS

Records for patients with a diagnosis of invasive cervical carcinoma from 1988 to 1999 were obtained from the Automated Central Tumor Registry for the United States Military Health Care System. Clinical data including race, age at diagnosis, histology, grade, stage, socioeconomic status, treatment modality, and survival also were obtained. Survival analysis was performed with Kaplan-Meier survival curves.

RESULTS

One thousand five hundred fifty-three patients were obtained for review. Sixty-five percent of patients were Caucasian, and 35% were minorities. Of the minorities, 29% were African Americans (AAs). Mean age of diagnosis was similar among AAs and Caucasians, 44 and 42 years, respectively. There was no statistically significant difference between the distribution of age, stage, grade, or histology between Caucasians and AAs. Forty-six percent of patients were treated with surgery and 56% with radiation therapy, with no difference in type of treatment between the Caucasian and AA groups. Five- and 10-year survival rates for Caucasians and AAs were 75%, and 76%, and 64% 65% (P = 0.59), respectively.

CONCLUSIONS

In an equal access, unbiased, nonracial environment, race is not an independent predictor of survival for patients with cervical carcinoma. This study has shown, for the first time to the authors' knowledge, that when they receive equal treatment for cervical carcinoma, AA women's survival can approach that of their nonminority counterparts (75% at 10 years).

Nonlinear phase adjustment of selective excitation pulses

A continuous transformation of an RF waveform with a modified Korteweg-de Vries equation or generalization can be used to adjust the phase behavior of a selective excitation pulse while preserving the magnitude behavior of the spin response. This transformation has applications in removing or adding to the nonlinear phase properties of a selected region.

Estimated HIV risk among Hispanics in a national sample of drug users

OBJECTIVE

To estimate and compare the HIV risks among three Hispanic subpopulations.

METHODS

Chronic drug users participating in a nationwide intervention study on drug use were interviewed with regard to drug use and sexual behavior. HIV risk was estimated using information about individuals' HIV-relevant behaviors, the social context (i.e., city) in which such behaviors occur, and published estimates of HIV transmission for various risk behaviors. Multiple linear regression analysis was used to investigate differences in estimated HIV risk between Puerto Rican, Mexican-American, and Mexican drug users, accounting for sociodemographic factors, sexual preference, and geographic region.

RESULTS

Puerto Ricans had significantly greater estimated overall HIV risk, estimated injection risk, and in general, significantly greater estimated sexual risk than Mexican Americans and Mexicans. No significant differences were found in any estimated risk between Mexican Americans and Mexicans in this sample. No significant differences were found among any of the subgroups for estimated risk from having anal sex while using a condom, or from having receptive anal sex without using a condom.

CONCLUSIONS

These findings suggest that Puerto Ricans who use drugs experience a higher risk of HIV infection than other Hispanic drug users. Research is needed to identify which economic, social, and cultural components account for this increased risk.

An analysis of drug abuse policies in teaching hospitals

The Drug-Free Workplace Act of 1988 mandated written drug abuse policies for recipients of certain government grants and contracts. The literature has reported costly side effects of employee drug abuse such as decreased productivity and increased use of health benefits. Furthermore, litigation involving drug abuse policies has been increasingly won by employers. More than 90% of Fortune 1000 companies have adopted formal drug abuse policies. Using content analysis techniques, the current study examined the written substance abuse policies of 30 large American teaching hospitals. Results showed substantial variation in the style and content of the policies. In general, language used in the policies was vague. The study cites the potential use of strategic ambiguity in the development of the policies.

The social ecology of drug use: a factor analysis of an urban environment

Drug use is related to the environment in which drug users live. Using 32 economic, housing, crime, and health variables for 1990 census tracts in Houston, Texas, this study found four identifiable factors: social disorganization, economic success, threat of violence, and chronic disease. Narcotic offenses loaded strongly on one and weakly on two of the factors; this variable did not load on the economic success factor. These results suggest that a textured look at drug use environments finds them to be multidimensional. Urban dwellers must deal with the independent effects of social disorganization, economic conditions, chronic disease, and violence.

Reconstitution and imaging of a membrane protein in a nanometer-size phospholipid bilayer

A phospholipid bilayer of nanometer dimension has been used as a support for the study of reconstituted functional single-membrane proteins. This nanobilayer consists of an approximately 10-nm-diameter circular phospholipid domain stabilized by apolipoprotein A1. As a demonstration of this methodology, we formed the nanobilayers in the presence of hepatic microsomal NADPH-cytochrome P450 reductase. Incubation of a solution of enzyme-containing nanobilayers with a freshly cleaved mica substrate resulted in the spontaneous formation of a fully oriented supported monolayer of discoidal phospholipid domains. The P450-reductase in the oriented monolayer retains its catalytic activity. Characterization by scanning force microscopy revealed isolated single-membrane proteins that could be stably imaged over time. These results define a novel technique for the study of single-membrane proteins in a bilayer environment.

Imaging and manipulation of high-density lipoproteins

The atomic force microscope (AFM) has been used to image a variety of biological systems, but has rarely been applied to soluble protein-lipid complexes. One of the primary physiological protein-lipid complexes is the high-density lipoproteins (HDL), responsible for the transport of cholesterol from the peripheral tissues and other lipoproteins to the liver. We have used the AFM to directly image discoidal reconstituted HDL (rHDL) particles for the first time. The height of these particles is consistent with a phospholipid bilayer structure, but careful high resolution measurements of particle diameters has indicated that they fuse when adsorbed to mica. Furthermore, it has been demonstrated that the AFM can be used to initiate this bilayer fusion in a controlled manner, allowing the fabrication of stabilized, nanometer scale, phospholipid bilayer "domains."

Chemoprophylaxis with ciprofloxacin in ovarian cancer patients receiving paclitaxel: a randomized trial

The objective of this study was to evaluate the efficacy of oral ciprofloxacin in preventing febrile morbidity superimposed on the neutropenia induced from a paclitaxel regimen in ovarian cancer patients. Eligible patients received paclitaxel at doses of 135 to 175 mg/m2 alone or in combination with a platinum agent. They were randomized to either an observation (control) group or a ciprofloxacin prophylaxis group. Patients in the ciprofloxacin group received 500 mg ciprofloxacin orally twice a day once the absolute neutrophil count (ANC) was less than 500/mm3 and continued until the ANC was greater than 1000/mm3. Ninety patients were enrolled between the control (n = 45) and ciprofloxacin (n = 45) groups. They received 371 cycles of a paclitaxel-based regimen with 177 and 194 cycles in the control and ciprofloxacin groups, respectively. Ciprofloxacin prophylaxis was prescribed for 138 (71%) of the cycles in the ciprofloxacin group and was given for a mean duration of 7.7 days per cycle. The groups were similar in disease status and risk factors for neutropenia. Fifteen patients in the control group developed febrile neutropenia versus 12 of those in the ciprofloxacin group (P = 0.69). The mean ANC and mean length of hospital stay for neutropenic fever were also similar between groups. There was a greater frequency of an ANC < 100 associated with those prophylaxed with ciprofloxacin (P = 0.01). Only 44% of the febrile episodes were associated with a positive culture. Staphylococcus aureus was the most frequently reported organism isolated. Considering these results, it does not appear that febrile neutropenia is reduced by ciprofloxacin during grade IV neutropenia.

Managed care, cost-effectiveness, and rehabilitation: the case of HIV

Because of its cost-effective approach to impairment and disability, rehabilitation therapy is uniquely positioned to assume a significant role in today's healthcare environment. As the cost of health care has become a major concern, both the government and the private insurance industry have turned toward rehabilitation services as resources for preventing more costly use of the healthcare system in the future. Although funding in the area of injury research scarce, funding for demonstrating the success of therapies for chronic illness such as HIV is more plentiful. In the case of HIV, rehabilitation nursing techniques and principles can be used as a model for reducing the substantial social costs of the disease. Specifically, rehabilitation nurses can assume a leadership role as service coordinators for HIV-positive patients. If rehabilitation nurses perform this role effectively and participate fully in research efforts aimed at measuring the success of rehabilitation therapy, their efforts have the potential of permanently raising the status of the rehabilitation nursing specialty.

Oncogenes in gynecologic oncology

Advances in molecular biology have facilitated the recent investigation of gynecological malignancies. The presence of certain oncogenes within gynecological tumors indicates that transformation may be associated with genetic alteration of normal regulatory processes. This paper reviews several oncogenes that have been implicated in the transformation of gynecological tissues.

A method for the calculation of currents on shielded gradient coils

Alternate expressions for the current density on the shielding surface of a gradient coil are derived for cylindrical, planar, and hyperbolic gradient coils. For the planar and hyperbolic geometries, these expressions allow more rapid high-precision calculations of current densities than the conventional solution.

Point-of-care systems, informatics, and health care delivery

Evolving information technology has had profound effects on business operations and the marketplace. The health care services industry, particularly hospitals, clinics, and medical offices, has historically lagged behind other industries in the implementation of comprehensive, integrated, computerized data management tools. Health care reformers are looking to the promises of the information technology "revolution" as a means of improving systemic efficiency and health care quality. This study discusses the impact of informatics, or information technology, on the delivery of health care services. We present the evolution of informatics and the predicted future benefits of integrated computerized patient records and point-of-care systems.

Gynecologic reconstruction with a rectus abdominis myocutaneous flap: an update

This series reports the outcomes and significant complications associated with the rectus myocutaneous flap when used for pelvic or inguinal reconstruction in patients with gynecologic cancers. Perioperative variables were retrospectively reviewed to identify social and medical risk factors as well as intraoperative and postoperative complications that predisposed to rectus flap failure. Fifteen patients with gynecologic malignancies underwent reconstructive procedures using a vertically oriented rectus abdominis myocutaneous flap for either vaginal (n = 14) or inguinal (n = 1) reconstruction. The patients' primary cancers were cervical (n = 11), rectal (n = 1), ovarian (n = 1), vulvar (n = 1), and vaginal (n = 1). The median age was 50 years. The median follow-up was 17 months. All flaps were mobilized in conjunction with a radical salvage operation. There were no cases of vaginal prolapse and no abdominal wound infections. However, 4 patients (27%) had major postoperative morbidity in this small series. There was one wound dehiscence and three episodes of necrosis of the subcutaneous and cutaneous portions of the flap. All 4 of these patients required additional operative intervention or debridement. Eleven patients had complete healing of the flap. The rectus abdominis myocutaneous flap is a valuable option for gynecologic reconstructive procedures. Perioperative strategies for improving flap viability include the identification of risk factors that may compromise flap perfusions such as prior abdominal incisions, peripheral vascular disease, and obesity. Meticulous surgical technique is required to preserve the vascular pedicle. These strategies may be useful in preoperative counseling, the perioperative evaluation, and the intraoperative management.

Sebaceous carcinoma of the vulva: a case report and review of the literature

Although sebaceous glands are prominent on the vulva, sebaceous carcinomas of the vulva rarely occur. In fact, there have been only two cases of sebaceous carcinomas of the vulva reported in the literature. Eighty percent of vulvar cancers are squamous in origin with human papillomavirus (HPV) DNA detected in approximately 60% of these cancers. We present a third patient with sebaceous carcinoma of the vulva and the first to our knowledge that has been analyzed for HPV DNA. The case report and a review of the literature are presented.

Nonsurgical management strategies for the functional complications of ileocolonic continent urinary reservoirs

Urinary diversion with creation of a continent ileocolonic reservoir was performed in 25 patients with gynecological malignancies at our institution between September 1989 and September 1994. A retrospective review was conducted and cases were analyzed for functional complications associated with reservoir formation. Functional reservoir complications were defined as (1) difficulty with catheterization, (2) reservoir fistulae, (3) reservoir stones, and (4) ureteral stenosis. Management strategies and outcomes for these complications were determined. All patients had received prior pelvic radiation therapy. There was no surgical mortality. Median follow-up was 21 months, and 16 patients (64%) are currently alive. Fourteen of the patients (56%) had one or more complications attributable to a functional aspect of the continent reservoir. Two patients had difficulty with catheterization (8%), two patients had reservoir leak (8%), and one patient had reservoir stones (4%). Nonsurgical management strategies were used in these cases including balloon dilation of the ileocecal valve, stomal dilation, ureteral stenting, percutaneous nephrostomy, and endoscopic lithotripsy. All cases of catheterization problems, reservoir fistulae, and reservoir stones were resolved with nonoperative techniques. Thirteen of 50 ureters (26%) had some degree of stenosis. Percutaneous balloon dilation was utilized in nine cases of ureteral stenosis. Relief of stenosis was complete in five, partial in two, and not achieved in two of the cases. No patients required a reoperation for a reservoir complication. In conclusion, continent ileocolonic urinary diversion can be performed in patients previously treated with radiotherapy; however, functional reservoir problems may occur. Interventional radiology strategies are useful in managing many of these problems and reexploration can be successfully avoided.

Shielded gradient coils on hyperbolic surfaces of revolution

A formalism for the calculation of fields generated by current distributions on hyperbolic surfaces of revolution is presented and used to generate designs for shielded gradient coils. One application is the development of small, insertable coils suitable for head imaging while allowing clearance for shoulders. This technique demonstrates that efficient designs that offer substantial advantages over conventional cylindrical designs are possible.

Recurrent squamous cell carcinoma in a rectus abdominis neovagina

The development of a carcinoma in a neovagina is rare. Most neovaginal neoplasias have been carcinomas in situ in the skin graft. To date, there has not been a report of a neovaginal carcinoma in a myocutaneous flap. This report is the first of a squamous cell carcinoma arising in a neovagina constructed from a rectus abdominis myocutaneous flap.

Room-temperature fluorozirconate glass fiber laser in the violet (412 nm)

Continuous oscillation on the (2)P(3/2) ? (4)I(11/2) transition of Nd(3+) in a f luorozirconate glass (ZBLAN) fiber at room temperature has been observed. When pumped at ~590 nm, a Nd:ZBLAN f iber 39 cm in length lases in the violet at 412 nm and produces ~0.5 mW of power for 320 mW of pump power and a cavity output coupling of 0.4%. The breadth of the laser's excitation spectrum is ~12 nm (581-593 nm).

Management of pelvic venous stenosis with intravascular stainless steel stents

Patients with gynecologic malignancies may develop stenosis of the large pelvic veins as a result of their disease or its treatment. The percutaneous insertion of a stainless steel vascular stent is a novel approach to the management of an extrinsically compressed vein. The objective of this study was to review the results of treating lower extremity edema secondary to a pelvic venous stenosis through the percutaneous insertion of a stainless steel vascular stent. A retrospective review was performed on gynecologic oncology patients who presented with an edematous lower extremity and underwent an evaluation to diagnose proximal venous stenosis. The evaluation included sonography, venography, and balloon angioplasty prior to the percutaneous insertion of a stainless steel vascular stent. If a venous thrombosis was documented, thrombolysis with urokinase was performed prior to evaluation for venous stenosis. Records were reviewed for the etiology of the venous stenosis, the location and type of stent inserted, and the ability of the stent to maintain patency and provide symptomatic relief. Patency was evaluated at 1-week and then at 1-, 3-, and 6-month intervals. The probability of vascular stent patency was calculated using life table analysis. Ten patients with cervical (n = 4), corpus (n = 3), ovarian (n = 1), vulvar (n = 1), and vaginal (n = 1) cancer had one or more vascular stents inserted for the treatment of a stenosed pelvic vein. The etiologies of venous stenosis were radiation fibrosis and surgery (n = 5), postoperative fibrosis (n = 3), and metastatic tumor (n = 2). The stented vessels were the left common (n = 5) or left external (n = 4) iliac veins, the right common (n = 1) or right external (n = 3) iliac veins, and the right common femoral vein (n = 1). The median follow-up was 21 months. All patients had subjective resolution of their edematous extremity while the stents were patent. The interval probability of patency of stented veins was greater than 85% at each evaluation interval. Patency was 100% for patients beyond 6 months of follow-up. There were no major complications. The percutaneous intravascular insertion of a stainless steel stent was safe and subjectively effective in the management of venous stenosis associated with a gynecologic cancer. A prospective trial with objective endpoints may be warranted.

Blood flow characteristics of ovarian tumors: implications for ovarian cancer screening

OBJECTIVES

Our purpose was to investigate the blood flow characteristics of benign and malignant ovarian tumors. Questions posed by our research were as follows: (1) Can malignant ovarian tumors be predicted by color flow Doppler imaging? (2) What are the sensitivity, specificity, and positive and negative predictive values of such prediction? (3) Which color flow Doppler parameter is superior in its accuracy of prediction?

STUDY DESIGN

One hundred twenty-three consecutive patients seen for suspected pelvic masses were evaluated by transvaginal ultrasonography and color flow Doppler imaging. A morphologic assessment was initially performed, followed by color flow Doppler analysis. A comparison of findings between the benign and malignant tumors was made by analyzing different thresholds of the intratumoral pulsatility and resistance index values by means of receiver-operator characteristic curves. By calculation of the area index under each receiver-operator characteristic curve the efficiency of the pulsatility and resistance index values in predicting malignancy was determined.

RESULTS

Fifty-six benign and 23 malignant tumors were pathologically confirmed. Patients with malignant tumors were more likely to be postmenopausal and were older than patients with benign tumors. Malignant tumors were more likely to be larger and to have either a complex or solid pattern. Absent color flow was more common in benign tumors, and increased color flow was found equally among benign and malignant tumors. There was no difference in systolic, diastolic, or mean velocities between benign and malignant tumors. The calculated pulsatility and resistance index values were lower in patients with malignant tumors compared with those with benign tumors. No significant difference exists in performance of either the pulsatility or resistance index in predicting malignancy. The best thresholds for predicting malignancy were obtained with a pulsatility index of 1.0 and resistance index of 0.6.

CONCLUSIONS

Transvaginal ultrasonography is accurate in distinguishing benign from malignant ovarian tumors. Color flow Doppler findings are not specific enough to be used independent of gray-scale ultrasonography.

The utility of preoperative screening colonoscopy in gynecologic oncology

The American Cancer Society (ACS) recommends that asymptomatic women, age 50 and over, undergo sigmoidoscopy every 3 to 5 years, after two negative yearly exams. Epidemiologic evidence suggests that women with gynecologic or breast cancers have an increased risk of developing colon cancer. It is unclear whether the ACS guidelines are applicable for women with a new diagnosis of gynecologic malignancy. This retrospective study was undertaken to assess the usefulness of preoperative colonoscopy in our gynecologic oncology patient population. Patients undergoing evaluation for a major operative procedure for known or suspected gynecologic malignancies were referred for colonoscopy at the discretion of their attending surgeon. Five hundred patients' charts were reviewed to identify 212 patients in whom preoperative colonoscopy was performed (the study group). In this group, 17 cases of colonic polyps, 5 cases of synchronous colon cancer, and 2 cases of cancer metastatic to the colon were discovered, representing 11% of the study group. Whereas 23% of the patients screened were less than 50 years of age, only two cases of polyps occurred in this age group, and no cases of cancer. Patients aged 70 or greater made up 28% of the study group, but accounted for 41% of the cases of polyps and 40% of the colon cancers. Twenty-nine percent of the study group had adenocarcinoma of the endometrium, representing 7 of 17 cases of polyps, 1 of 5 colon cancers, and 1 of 2 metastatic cancers. Although this retrospective study involved colonoscopy, the locations of the observed lesions were within the theoretic reach of a flexible sigmoidoscope in 75% of cases. We conclude that in the preoperative workup of gynecologic oncology patients, no colon screening is needed in the asymptomatic patient less than 50 years of age. ACS guidelines are appropriate for patients aged 50-70, but for those 70 or greater we would consider full colonoscopy.

Chemoprophylaxis with oral ciprofloxacin in ovarian cancer patients receiving taxol

The purpose of this study was to review the clinical outcomes and cost of administration of a prophylactic antibiotic compared to G-CSF for the prevention of neutropenic morbidity associated with taxol. The study group was composed of 62 patients with ovarian cancer who received a 24-h infusion of a taxol-based regimen at doses less than or equal to 175 mg/m2 between June 1992 and April 1994. The records were retrospectively reviewed and the patients were grouped and analyzed according to the management of their myelosuppression. Group I patients (n = 29) were observed until their absolute neutrophil count (ANC) was less than 500/microliters and then were placed on ciprofloxacin 500 mg orally twice a day until their ANC was 1,000/microliters. Group II patients (n = 15) received G-CSF from Day 2 until the ANC was greater than 10,000/microliters beginning with their first cycle. Group III patients (n = 18) received their taxol regimen without either ciprofloxacin or G-CSF. Two hundred eighty-two taxol-based chemotherapy cycles were administered to these 62 patients. There was no statistically significant difference between the groups concerning disease status as measured by age, stage, performance status, dose intensity, or number of previous regimens. There were two episodes of febrile neutropenia in Group I and three episodes in Group II. Group III had 15 episodes of febrile neutropenia. The estimated cost of the different prophylactic regimens was $5,215.00 for Group I versus $104,000.00 for G-CSF in Group II. Within the three groups, there were 27 patients with an episode of febrile neutropenia (n = 20) or prolonged myelosuppression (n = 7) that were followed for an additional 104 taxol cycles. Twenty-four of these patients received G-CSF prophylaxis with intermittent ciprofloxacin and three received only ciprofloxacin. There were eight more episodes of febrile neutropenia in the patients receiving G-CSF. There were no additional febrile episodes on cycles prophylaxed with ciprofloxacin. There was no septic mortality. For patients receiving a 24 h infusion of taxol at doses less than 175 mg/m2, ciprofloxacin given through the ANC nadir may be effective in preventing febrile morbidity. A prospective randomized trial is underway to evaluate this approach.

Gray scale and color flow Doppler characterization of uterine tumors

The aim of this study was to investigate gray scale and color flow characteristics of a group of patients with a suspected uterine pathologic condition. One hundred and twenty-two consecutive patients at the Women's Cancer Center, University of Minnesota, undergoing transvaginal sonography and color flow Doppler imaging for suspected uterine corpus abnormality made up the study group. After gray scale morphologic assessment, color flow Doppler imaging of the tumor and uterus was performed, including the ipsilateral uterine artery. Malignant tumors were confirmed pathologically in all 35 patients who had them. In comparing patients with benign versus malignant tumors, gray scale morphologic assessment confirmed that malignant uterine tumors (31 endometrial cancers and four sarcomas) were more likely to have a thickened echoic endometrium (P = < 0.0001), be enlarged (P = 0.004), to be retroverted (P = 0.02), and to lack a subendometrial halo (P < 0.0001). Patients with four benign and 13 malignant tumors demonstrated increased flow when assessed by CFD. The calculated sensitivity of increased color flow in predicting malignancy was 39%, with a specificity of 92%, a positive predictive value of 77%, and a negative predictive value of 71%. No difference existed between the benign and malignant groups for the systolic, diastolic, and mean velocities and for the calculated pulsatility index and resistive index in both sampled uterine and intramyometrial or tumor vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Laser ablation of squamous cell carcinoma in situ of the anal canal. A case report

A case of squamous cell carcinoma in situ of the anal canal was discovered incidentally during a hemorrhoidectomy in a man. The anal canal was evaluated by colposcopy prior to ablation of the lesion with a CO2 laser. To our knowledge, this technique has not been reported previously.

Pelvic adhesion formation after pelvic lymphadenectomy: comparison between transperitoneal laparoscopy and extraperitoneal laparotomy in a porcine model

Compared to extraperitoneal laparotomy, the transperitoneal approach is associated with increased enteric morbidity. Recently, transperitoneal laparoscopy has been employed as a method to surgically stage patients with gynecologic malignancies. The objective of this study was to investigate pelvic adhesion formation in a porcine model after pelvic lymphadenectomy performed via transperitoneal laparoscopy (LS) compared to extraperitoneal laparotomy (EP). Ten adult, female hogs underwent LS and 10 underwent EP. A complete pelvic lymphadenectomy was performed in each animal. Three weeks after the lymphadenectomy, the animals underwent exploratory laparotomy, and the adhesions were quantified. Nineteen animals were evaluable. The adhesion scores for the laparoscopy group (N = 10, mean = 0.075 +/- 0.17) were not statistically different from those of the laparotomy group (N = 9, mean = 0.28 +/- 0.52, P > 0.5). Eight of 10 (80%) and 5 of 9 (56%) animals in the LS and EP groups, respectively, had no adhesions after pelvic lymphadenectomy. Adhesion formation is one of many critical issues concerning the utility of pretreatment surgical staging, especially for cancer of the cervix. It is remarkable that only 20% of the animals undergoing laparoscopy in this study had de novo adhesions after pelvic lymph node dissection and that the mean total adhesion score was not statistically different from the extraperitoneal laparotomy. Therefore, transperitoneal laparoscopic pelvic lymphadenectomy may not induce the degree of adhesion formation associated with the transperitoneal laparotomy technique.

Radical vulvectomy with postoperative irradiation for vulvar cancer: therapeutic implications of a central block

PURPOSE/OBJECTIVE

To report the long-term results of vulvectomy, node dissection, and postoperative nodal irradiation using a midline vulvar block in patients with node positive vulvar cancer.

METHODS AND MATERIALS

From 1971 through 1992, 27 patients with carcinoma of the vulva and histologically involved inguinal lymph nodes were treated postoperatively with radiation therapy after radical vulvectomy and bilateral lymphadenectomy (n = 25), radical vulvectomy and unilateral lymphadenectomy (n = 1), or hemivulvectomy and bilateral lymphadenectomy (n = 1). Federation Internationale de Gynecologic et d'Obstetrique stages were III (n = 14), IVA (n = 8), and IVB (n = 5) squamous cell carcinoma. Inguinal lymph nodes were involved with tumor in all patients (average number positive = 4, range 1-15). Postoperative irradiation was directed at the bilateral groin and pelvic nodes (n = 19), unilateral groin and pelvic nodes (n = 6), or unilateral groin only (n = 1). These 26 patients had the midline blocked. In addition, one patient received irradiation to the entire pelvis and perineum. Doses ranged from 10.8 to 50.7 Gy (median 45.5) with all patients except 1 receiving > or = 42.0 Gy.

RESULTS

Actuarial 5-year overall survival and disease-free survival estimates were 40% and 35%, respectively. Recurrences developed in 63% (17/27) of the patients at a median of 9 months from surgery (range 3 months to 6 years) and 15 of these have died; two patients with recurrences are surviving at 24 and 96 months after further surgery and radiation therapy. Central recurrences (under the midline block) were present in 13 of these 17 patients (76%), either as central only (n = 8), central and regional (n = 4), or central and distant (n = 1). Additionally, three patients developed regional recurrences and one patient developed a concurrent regional and distant relapse. One patient developed a squamous cell cancer of the anus under the midline block 54 months after the initial vulvar cancer and an additional patient developed transitional cell carcinoma of the ureter (outside the radiation field) 12 months after diagnosis. Factors associated with a decreased relapse-free survival included increasing Federation Internationale de Gynecologic et d'Obstetrique stage (p = 0.01) and invasion of the tumor into the subcutaneous (SC) fat or deep soft tissue (p = 0.05). Chronic lower extremity edema developed in four patients, but there have been no other complications.

CONCLUSIONS

Radical vulvectomy has often been considered sufficient central treatment for vulvar carcinoma, with postoperative irradiation directed only to the nodes. Although designed to protect the radiosensitive vulva, use of a midline block in this series resulted in a 48% (13/27) central recurrence rate, much higher than the 8.5% rate previously reported with this technique. Routine use of the midline block should be abandoned and, instead, postoperative irradiation volumes should be tailored to the individual patient.

Rectus abdominis myocutaneous flap for primary vaginal reconstruction

Reconstructive procedures are being performed with increasing frequency in conjunction with pelvic exenterations and other radical gynecologic surgeries. The most common reconstructive procedures include continent urinary diversion, rectosigmoid anastomosis, and vaginal reconstruction. Historically, the gracilis myocutaneous flap has been the procedure of choice for vaginal reconstruction. However, the gracilis myocutaneous flap has a history of partial to severe necrosis, a propensity to prolapse, and leaves ipsilateral donor scars on the thigh. In contrast, neovaginal reconstruction using a relatively new procedure, the distally based rectus abdominis myocutaneous flaps, has the advantage of using a large, single flap that can be incorporated into the primary incision. This flap is mobilized on a long vascular pedicle, the rectus muscle. In relation to the underlying rectus muscle, the orientation of the cutaneous portion of this flap may be customized to accommodate the pelvic defect or the surgeon's preference. Depending on their primary orientation, they are referred to as either a vertical or transverse rectus abdominis myocutaneous flap. The versatility and reliability of the rectus flap is demonstrated here through the presentation of a small pilot series of seven patients. The technique was used for vaginal reconstruction, primarily in conjunction with pelvic exenteration. The flaps were mobilized from the supraumbilical area and had a flap viability of 100% for the 2 years that they have been followed. There were no postoperative incisional or flap infections. There was one infraumbilical fascial dehiscence. The advantages of primary pelvic reconstruction along with the description of the operative techniques are presented.

Lymph node yield from laparoscopic lymphadenectomy in cervical cancer: a comparative study

Pretreatment surgical staging in cervical cancer has been studied extensively but remains controversial because a surgical procedure is required and the information gained may benefit only a small portion of the patients staged. Pelvic and paraaortic laparoscopic lymphadenectomies have been successfully performed in animal models and humans. Little information regarding the validity of the procedure in patients who have had subsequent laparotomy exists. In this series, we report our preliminary experience in 12 patients who underwent laparoscopic lymphadenectomy and then laparotomy. Overall, 377 pelvic nodes were removed, with 282 (75%) obtained at laparoscopy. The average number of pelvic nodes removed at laparoscopy was 23.5 (range 7-33). Two patients had positive pelvic nodes. No patient with negative nodes at laparoscopy had positive nodes at laparotomy. When studied in chronological order, the lymph node yield from our second 6 patients was much improved over our first 6 patients, 85% versus 63% (P < 0.005). Laparoscopy also proved to be a better predictor of lymph node spread than computed tomography. Two patients also had right-sided paraaortic lymphadenectomies, yielding 8 and 5 nodes. No additional right-sided paraaortic nodes were detected at laparotomy for either patient. In this preliminary series, laparoscopic lymphadenectomy appears to be a feasible procedure for surgical staging of cervical cancer. The yield of pelvic lymph nodes is adequate and improved with experience. Most importantly, no positive lymph nodes were missed by laparoscopy. The indications for operative laparoscopy have expanded rapidly. Gynecologic oncologists performing this procedure should be involved in prospective studies of this technique to set the standards and indications of this new technology.

Differentiation of silicone gel from water and fat in MR phase imaging of protons at 0.064 T

The authors present a method of identifying silicone at magnetic resonance (MR) imaging based on its chemical shift. The method relies on phase images reconstructed from a gradient-recalled-echo sequence that has an echo time chosen to maximize the phase offsets between water, fat, and silicone. Results from studies at 0.064 T of both phantoms and human subjects are presented. This technique was useful in identifying extracapsular silicone and may be applicable at other field strengths.

Imaging time reduction through multiple receiver coil data acquisition and image reconstruction

A technique is described for the simultaneous acquisition of MRI data using two independent receiver coils surrounding the same region of tissue, which enables the collection of data necessary for image reconstruction in a reduced number of phase-encoded acquisitions. This results in a 50% reduction in minimum scan time and may be useful in time-critical procedures. The algorithm and imaging procedures are described, and example images are shown that illustrate the reconstruction. Signal to noise is decreased by the square root of the time savings, making this technique applicable to cases in which the need to decrease minimum scan time outweighs the signal to noise penalty.

Management of osteogenesis imperfecta in pregnancy. A case report

Osteogenesis imperfecta (OI) is a metabolic disorder of connective tissue; it is typically characterized by blue sclera, bone fragility and deformity secondary to repetitive fractures. The severity of the disease in the infant cannot be predicted by the phenotypic presentation of the mother. We present a case report and review literature and discuss the prenatal diagnosis, evaluation criteria and guidelines for delivery.

MR relaxometry imaging. Work in progress

Acquisition of relaxation rate dispersion curves from magnetic resonance images was demonstrated on a clinical, whole-body imaging system. Study of the behavior of relaxation rates over a range of field strengths probes the structural environment of imaged hydrogen protons and reveals information about the composition of tissue. The authors determined relaxation rates in extremities and heads of healthy volunteers. The sensitivity of the measurement is sufficient to obtain a distinctive relaxation rate dispersion behavior for different tissues.

Design and evaluation of shielded gradient coils

Techniques are described for the design of shielded gradient coils for superconducting MRI systems. These design methods are suited for constructing the most efficient gradient coil that meets a specified homogeneity requirement. Tradeoffs in coil design of efficiency with coil size and gap size are discussed. Residual eddy currents from coils constructed with a finite number of wires are calculated and give guidelines for the construction of efficient, whole-body gradient coils.

Electromagnetic fields of surface coil in vivo NMR at high frequencies

A high frequency solution of the electromagnetic field produced by a circular surface coil adjacent to a homogeneous conducting, dielectric sphere is used to predict the attainable signal to noise ratio (S/N) and specific absorption rate (SAR) for in vivo 1H NMR spectroscopy experiments from 200 to 430 MHz (4.7-10 T). Above 200 MHz the S/N increases more rapidly with frequency and the SAR increases less rapidly compared with the respective S/N and SAR frequency dependence below 200 MHz. The difference in frequency dependence is due to dielectric resonances of the magnetic field inside the sphere at frequencies above 200 MHz. It is predicted that surface coil 1H NMR experiments may be performed on a head-sized sphere, having conductivity and relative dielectric constant of brain, at frequencies up to 430 MHz without exceeding 8 W/kg local SAR and 3.2 W/kg SAR. The calculations of the S/N and SAR are used to determine optimum surface coil geometries for NMR experiments. The power radiated by the surface coil in the absence of shielding and asymmetries in the received signal with respect to the plane defined by the surface coil axis and the direction of the static magnetic field are significant at high frequency. Experimental measurements of the magnetic field inside a head-sized sphere verify the presence of dielectric resonances at frequencies above 200 MHz.

A case report of massive vulvar edema during tocolysis of preterm labor

Bilateral vulvar edema that is not associated with preeclampsia has been reported only rarely during pregnancy or the puerperium. A primiparous patient in premature labor at 34 weeks' gestation with no history of lymphatic or venous obstruction underwent combination tocolysis with intravenous ritodrine and magnesium sulfate. On the fifth day of tocolysis, edema developed in the right labium majus pudendi and gradually spread to the left labia during the ensuing 24 hours. The patient remained afebrile, normotensive, and without signs of localized infection or anasarca. A trial of triple intravenous antibiotics and local skin care proved ineffective. By the ninth hospital day, the edema and discomfort had progressed, thereby precluding vaginal examination without sedation. In spite of progressive cervical dilatation with tocolysis, cesarean delivery was performed. With no further treatment, the vulvar edema gradually resolved during the next week.

Rapid radiofrequency calibration in MRI

A collection of modified procedures for setting rf transmitter levels using a three-pulse sequence is described. Based on a geometrically weighted ratio of four signals, an estimate of the flip angle is calculated and used for an updating prescription. These techniques are designed to perform rapidly yet eschew systematic errors due to relaxation during the pulse sequence.