Pre-Operative Radiotherapy in STS: Does Downsizing Matter?

PURPOSE/OBJECTIVE(S)

Soft tissue sarcomas (STS) are a rare but insidious tumor that arises from mesenchymal tissue. Preoperative RT, followed by resection, is routinely used in extremity and truncal STS. The impact of RT on tumor volume and implications for prognosis is a great concern for patients, as changes in volume is often perceived as a reflection of treatment response. To date, data between tumor volume changes after RT and overall survival (OS) and distant metastasis-free survival (DMFS) in STS is sparse. In this study, we investigate changes in tumor volume after preoperative RT and its impact on OS and DMFS.

MATERIALS/METHODS

Between 2000 and 2022, patients with stage I-III primary sarcoma of the extremity or trunk treated with pre-operative RT and wide resection were retrospectively reviewed from a prospective repository. Tumors were contoured using T2 sequences on MRIs within 2 weeks of initiation of RT and within 4 weeks post-RT. Tumor volume was determined using the medical image merge software. Univariate analysis (UVA) was performed using the log-rank test. Multivariate analysis (MVA) was performed using the Cox proportional hazards model.

RESULTS

One hundred thirty-two patients had both pre- and post-RT MRIs available for contours. Median follow-up was 6 years. Median age at diagnosis was 56 years (range = 19-92). Most patients had stage III (73%) disease in the lower extremity (75%). The most common histology was undifferentiated sarcoma (30%). Median dose was 50 Gy in 25 fractions. Chemotherapy was administered in 44 (33%) patients. Median tumor volume prior to and after RT was 198 cc (range = 7.49 - 3899.87) and 225.21 cc (range = 0-9879.2), respectively. A decrease in tumor volume was seen in 90 patients (68%) from pre- to post-RT. In these patients, the mean percent change was -35%. Forty-two patients had an increase in tumor volume post-RT with a mean percent change of 56%. Overall local control was 98%. The 2- and 5-year OS were 89% and 76%, respectively. The 2- and 5-year DMFS was 76% and 70%, respectively. On UVA, increased age (p < 0.001), KPS ≤80 (p = 0.002), and smokers (p = 0.009) were associated with decreased OS. No variables were associated with DMFS. On MVA, age (p = 0.01) was associated with decreased OS and female gender (p = 0.03) and high-grade disease was associated with decreased DMFS (p = 0.04) Change in tumor volume did not impact OS (p = 0.15) or DMFS (p = 0.75). The 2- and 5-year DMFS for patients with a decrease in tumor volume was 79% and 71%, respectively. The 2 and 5-year DMFS for patients with an increase in tumor volume was 77% and 70%, respectively. The 2- and 5-year OS for patients with a decrease in tumor volume was 92% and 80%, respectively. The 2 and 5-year OS for patients with an increase in tumor volume was 83% and 69%, respectively.

CONCLUSION

Change in tumor volume did not significantly impact OS and DMFS. Further studies with an increased sample size are warranted to corroborate these findings, however these results may assuage patient anxieties about the perceived tumor response to RT.

Differential Virulence Contributions of the Efflux Transporter MexAB-OprM in Pseudomonas syringae Infecting a Variety of Host Plants

Efflux transporters such as MexAB-OprM contribute to bacterial resistance to diverse antimicrobial compounds. Here, we show that MexB contributes to epiphytic and late-stage apoplastic growth of Pseudomonas syringae strain B728a, as well as lesion formation in common bean (Phaseolus vulgaris). Although a ∆mexB mutant formed fewer lesions after topical application to common bean, these lesions contain the same number of cells (10⁵ to 10⁷ cells) as those caused by the wild-type strain. The internalized population size of both the wild-type and the ∆mexB mutant within small samples of surface-sterilized asymptomatic portions of leaves varied from undetectably low to as high as 10⁵ cells/cm². Localized bacterial populations within individual lesions consistently exceeded 10⁵ cells/cm². Strain B728a was capable of moderate to extensive apoplastic growth in diverse host plants, including lima bean (P. lunatus), fava bean (Vicia faba), pepper (Capsicum annuum), Nicotiana benthamiana, sunflower (Helianthus annuus), and tomato (Solanum lycopersicum), but MexB was not required for growth in a subset of these plant species. A model is proposed that MexB provides resistance to as-yet-unidentified antimicrobials that differ between plant species. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

CLIP and Massively Parallel Functional Analysis of CELF6 Reveal a Role in Destabilizing Synaptic Gene mRNAs through Interaction with 3' UTR Elements

CELF6 is a CELF-RNA-binding protein, and thus part of a protein family with roles in human disease; however, its mRNA targets in the brain are largely unknown. Using cross-linking immunoprecipitation and sequencing (CLIP-seq), we define its CNS targets, which are enriched for 3' UTRs in synaptic protein-coding genes. Using a massively parallel reporter assay framework, we test the consequence of CELF6 expression on target sequences, with and without mutating putative binding motifs. Where CELF6 exerts an effect on sequences, it is largely to decrease RNA abundance, which is reversed by mutating UGU-rich motifs. This is also the case for CELF3-5, with a protein-dependent effect on magnitude. Finally, we demonstrate that targets are derepressed in CELF6-mutant mice, and at least two key CNS proteins, FOS and FGF13, show altered protein expression levels and localization. Our works find, in addition to previously identified roles in splicing, that CELF6 is associated with repression of its CNS targets via the 3' UTR in vivo.

CLIP and Massively Parallel Functional Analysis of CELF6 Reveal a Role in Destabilizing Synaptic Gene mRNAs through Interaction with 3' UTR Elements

CELF6 is a CELF-RNA-binding protein, and thus part of a protein family with roles in human disease; however, its mRNA targets in the brain are largely unknown. Using cross-linking immunoprecipitation and sequencing (CLIP-seq), we define its CNS targets, which are enriched for 3′ UTRs in synaptic protein-coding genes. Using a massively parallel reporter assay framework, we test the consequence of CELF6 expression on target sequences, with and without mutating putative binding motifs. Where CELF6 exerts an effect on sequences, it is largely to decrease RNA abundance, which is reversed by mutating UGU-rich motifs. This is also the case for CELF3–5, with a protein-dependent effect on magnitude. Finally, we demonstrate that targets are derepressed in CELF6-mutant mice, and at least two key CNS proteins, FOS and FGF13, show altered protein expression levels and localization. Our works find, in addition to previously identified roles in splicing, that CELF6 is associated with repression of its CNS targets via the 3′ UTR in vivo.

Rieger et al. assay the function of the RNA-binding protein CELF6 by defining its targets in the brain. They show that CELF6 largely binds 3′ UTRs of synaptic mRNAs. Using a massively parallel reporter assay, they further show that CELF6 and other CELFs are associated with lower mRNA abundance and that targets are derepressed in Celf6-knockout mice in vivo.

Synthetic and genomic regulatory elements reveal aspects of cis-regulatory grammar in mouse embryonic stem cells

In embryonic stem cells (ESCs), a core transcription factor (TF) network establishes the gene expression program necessary for pluripotency. To address how interactions between four key TFs contribute to cis-regulation in mouse ESCs, we assayed two massively parallel reporter assay (MPRA) libraries composed of binding sites for SOX2, POU5F1 (OCT4), KLF4, and ESRRB. Comparisons between synthetic cis-regulatory elements and genomic sequences with comparable binding site configurations revealed some aspects of a regulatory grammar. The expression of synthetic elements is influenced by both the number and arrangement of binding sites. This grammar plays only a small role for genomic sequences, as the relative activities of genomic sequences are best explained by the predicted occupancy of binding sites, regardless of binding site identity and positioning. Our results suggest that the effects of transcription factor binding sites (TFBS) are influenced by the order and orientation of sites, but that in the genome the overall occupancy of TFs is the primary determinant of activity.

Transcription factors are proteins that flip genetic switches; their role is to control when and where genes are active. They do this by binding to short stretches of DNA called cis-regulatory sequences. Each sequence can have several binding sites for different transcription factors, but it is largely unclear whether the transcription factors binding to the same regulatory sequence actually work together.

It is possible that each transcription factor may work independently and there only needs to be critical mass of transcription factors bound to throw the genetic switch. If this is the case, the most important features of a cis-regulatory sequence should be the number of binding sites it contains, and how tightly the transcription factors bind to those sites. The more transcription factors and the more strongly they bind, the more active the gene should be. An alternative option is that certain transcription factors may work better together, enhancing each other's effects such that the total effect is more than the sum of its parts. If this is true, the order, orientation and spacing of the binding sites within a sequence should matter more than the number.

One way to investigate to distinguish between these possibilities is to study mouse embryonic stem cells, which have a core set of four transcription factors. Looking directly at a real genome, however, can be confusing and it is difficult to measure the effects of different cis-regulatory sequences because genes differ in so many other ways. To tackle this problem, King et al. created a synthetic set of cis-regulatory sequences based on the four core transcription factors found in mouse stem cells.

The synthetic set had every combination of two, three or four of the binding sites, with each site either facing forwards or backwards along the DNA strand. King et al. attached each of the synthetic cis-regulatory sequences to a reporter gene to find out how well each sequence performed. This revealed that the cis-regulatory sequences with the most binding sites and the tightest binding affinities work best, suggesting that transcription factors mainly work independently.

There was evidence of some interaction between some transcription factors, because, of the synthetic sequences with four binding sites, some worked better than others, and there were patterns in the most effective binding site combinations. However, these effects were small and when King et al. went on to test sequences from the real mouse genome, the most important factor by far was the number of binding sites.

Synthetic libraries of DNA sequences allow researchers to examine gene regulation more clearly than is possible in real genomes. Yet this approach does have its limitations and it is impossible to capture every type of cis-regulatory sequence in one library. The next step to extend this work is to combine the two approaches, taking sequences from the real genome and manipulating them one by one. This could help to unravel the rules that govern how cis-regulatory sequences work in real cells.

LIN-42, the Caenorhabditis elegans PERIOD homolog, negatively regulates microRNA transcription

During C. elegans development, microRNAs (miRNAs) function as molecular switches that define temporal gene expression and cell lineage patterns in a dosage-dependent manner. It is critical, therefore, that the expression of miRNAs be tightly regulated so that target mRNA expression is properly controlled. The molecular mechanisms that function to optimize or control miRNA levels during development are unknown. Here we find that mutations in lin-42, the C. elegans homolog of the circadian-related period gene, suppress multiple dosage-dependent miRNA phenotypes including those involved in developmental timing and neuronal cell fate determination. Analysis of mature miRNA levels in lin-42 mutants indicates that lin-42 functions to attenuate miRNA expression. Through the analysis of transcriptional reporters, we show that the upstream cis-acting regulatory regions of several miRNA genes are sufficient to promote highly dynamic transcription that is coupled to the molting cycles of post-embryonic development. Immunoprecipitation of LIN-42 complexes indicates that LIN-42 binds the putative cis-regulatory regions of both non-coding and protein-coding genes and likely plays a role in regulating their transcription. Consistent with this hypothesis, analysis of miRNA transcriptional reporters in lin-42 mutants indicates that lin-42 regulates miRNA transcription. Surprisingly, strong loss-of-function mutations in lin-42 do not abolish the oscillatory expression patterns of lin-4 and let-7 transcription but lead to increased expression of these genes. We propose that lin-42 functions to negatively regulate the transcriptional output of multiple miRNAs and mRNAs and therefore coordinates the expression levels of genes that dictate temporal cell fate with other regulatory programs that promote rhythmic gene expression.

MicroRNAs play pervasive roles in controlling gene expression throughout animal development. Given that individual microRNAs are predicted to regulate hundreds of mRNAs and that most mRNA transcripts are microRNA targets, it is essential that the expression levels of microRNAs be tightly regulated. With the goal of unveiling factors that regulate the expression of microRNAs that control developmental timing, we identified lin-42, the C. elegans homolog of the human and Drosophila period gene implicated in circadian gene regulation, as a negative regulator of microRNA expression. By analyzing the transcriptional expression patterns of representative microRNAs, we found that the transcription of many microRNAs is normally highly dynamic and coupled aspects of post-embryonic growth and behavior. We suggest that lin-42 functions to modulate the transcriptional output of temporally-regulated microRNAs and mRNAs in order to maintain optimal expression of these genes throughout development.

Discharge-driven electric oxygen-iodine laser superlinear enhancement via increasing g0L

The authors report the development of an electric oxygen-iodine laser with higher output using a larger product of gain and gain length, g0L. A factor of 4.4 increase in laser power output on the 1315 nm atomic iodine transition was achieved with a factor of 3 increase in gain length. I(2P1/2) is pumped using energy transferred from O2(a1Δ) produced by flowing a gas mixture of O2-He-NO through three coaxial geometry radio-frequency discharges. Continuous wave (CW) average total laser power of 481 W was extracted with g0L=0.042.

Linking optimization and ecological models in a decision support tool for oyster restoration and management

Restoration of ecologically important marine species and habitats is restricted by funding constraints and hindered by lack of information about trade-offs among restoration goals and the effectiveness of alternative restoration strategies. Because ecosystems provide diverse human and ecological benefits, achieving one restoration benefit may take place at the expense of other benefits. This poses challenges when attempting to allocate limited resources to optimally achieve multiple benefits, and when defining measures of restoration success. We present a restoration decision-support tool that links ecosystem prediction and human use in a flexible "optimization" framework that clarifies important restoration trade-offs, makes location-specific recommendations, predicts benefits, and quantifies the associated costs (in the form of lost opportunities). The tool is illustrated by examining restoration options related to the eastern oyster, Crassostrea virginica, which supported an historically important fishery in Chesapeake Bay and provides a range of ecosystem services such as removing seston, enhancing water clarity, and creating benthic habitat. We use an optimization approach to identify the locations where oyster restoration efforts are most likely to maximize one or more benefits such as reduction in seston, increase in light penetration, spawning stock enhancement, and harvest, subject to funding constraints and other limitations. This proof-of-concept Oyster Restoration Optimization model (ORO) incorporates predictions from three-dimensional water quality (nutrients-phytoplankton zooplankton-detritus [NPZD] with oyster filtration) and larval transport models; calculates size- and salinity-dependent growth, mortality, and fecundity of oysters; and includes economic costs of restoration efforts. Model results indicate that restoration of oysters in different regions of the Chesapeake Bay would maximize different suites of benefits due to interactions between the physical characteristics of a system and nonlinear biological processes. For example, restoration locations that maximize harvest are not the same as those that would maximize spawning stock enhancement. Although preliminary, the ORO model demonstrates that our understanding of circulation patterns, single-species population dynamics and their interactions with the ecosystem can be integrated into one quantitative framework that optimizes spending allocations and provides explicit advice along with testable predictions. The ORO model has strengths and constraints as a tool to support restoration efforts and ecosystem approaches to fisheries management.

Significance of tumour calcification in ovarian carcinoma

The purpose of this study was to assess the pattern and significance of tumour calcification in ovarian carcinoma. Patients with calcifying ovarian carcinoma were identified from radiological reports. Their tumour characteristics, serum calcium levels, treatment and survival were compared with a control group of patients with non-calcifying disease. Patterns and distribution of calcification were assessed. Available serial CT scans were reviewed for changes in both soft-tissue and calcified disease according to RECIST (response evaluation criteria in solid tumours) criteria where feasible. Temporal changes in calcification were correlated with changes in soft tissue disease and CA125 levels. The calcified group numbered 122 (22 other patients had calcifying tumour but insufficient clinical data). Calcification in ovarian carcinoma had a prevalence of 8% (144/1721) in our series. There was a significant difference (p<0.001) between the two groups in the distribution of histological type, with serous tumours being more common in the calcified group (74/122 (61%)) than in the controls (509/1498 (34%)). The calcified tumour patients tended to have lower grade disease (p<0.001). No differences between the groups were found for age, treatment or serum calcium levels. Distribution of calcification was diffusely peritoneal in 34 patients, in association with a pelvic mass in 15, nodal in 11 and within the anterior abdominal wall in 2. There was no correlation between changes in calcification on serial CT scans and corresponding CA125 levels. In conclusion, calcification tends to occur most commonly in serous cystadenocarcinomata and in tumours of lower grade. Changes in calcification cannot be used as a marker of disease response.

Evaluation of the response to treatment of solid tumours - a consensus statement of the International Cancer Imaging Society

New guidelines to evaluate the response to treatment in solid tumors using imaging techniques have major limitations and important implications for radiological workload. This consensus statement from the International Cancer Imaging Society (ICIS) reviews the RECIST criteria and addresses several challenges regarding tumour measurement. Recommendations are made regarding tumour measurement and other issues are raised. The growing need to introduce a multimodality approach to monitoring response is recognized. ICIS welcomes a dialogue with the authors of RECIST to address issues raised in this review.

Measurement of tumour size in case selection for breast cancer therapy by clinical assessment and ultrasound

AIMS

Clinical assessment of tumour size is often used to choose between mastectomy and primary medical therapy. Clinical and imaging modalities may have varying levels of accuracy across the range of tumour sizes. The aim of this study was to compare the accuracy of clinical measurement and ultrasound in discriminating palpable tumours up to 3 cm vs those greater than 3 cm.

METHODS

A prospective analysis of 111 consecutive patients with palpable breast cancer was performed. All women had clinical measurement by caliper and ultrasound assessment prior to any needle biopsy. Clinical measurement and ultrasound assessment of size were compared to pathological tumour size of the surgical specimen.

RESULTS

Both clinical and ultrasound measurement underestimate the size of larger tumours. The overall accuracy of clinical assessment and ultrasound examination in correctly identifying a 30 mm cut off was 70.3 and 77.5%, respectively. Ultrasound was significantly more accurate at determining the size of tumours <30 mm (p=0.007) but there was no significant difference between both modalities in assessing tumours greater than 30 mm.

CONCLUSIONS

Ultrasound assessment of breast cancer size is more accurate than clinical assessment for tumours less than 30 mm. As clinical examination is as accurate on ultrasound for tumours greater than 30 mm, clinical assessment of tumour size alone is adequate to select patients for primary medical therapy or mastectomy.

A retrospective study comparing the individual modalities of triple assessment in the pre-operative diagnosis of invasive lobular breast carcinoma

AIMS

Early invasive lobular breast carcinoma (ILC) is associated with few symptoms and signs. The individual sensitivity of clinical examination, mammography, ultrasonography, cytology and core biopsy have each been reported to be of limited value. The aim of this study was to evaluate the accuracy of triple assessment in the pre-operative detection of patients identified to have ILC from their surgical pathology.

METHODS

Pure ILC was defined as tumours containing at least 90% lobular features. The triple assessment of 273 patients diagnosed primarily at our institution were reviewed.

RESULTS

87.5% of women were symptomatic and 12.5% were screen detected. The mean patient age was 59 (range 30-81) years and the median tumour size was 26 (range 5-110) mm. The main mammographic abnormalities were a spiculated lesion (33.3%), an ill-defined mass (33.3%) or architectural distortion (23.5%). The sensitivities for detecting ILC of each modality were: clinical examination (76.6%), mammography (79.8%), ultrasound examination (93.9%), fine-needle aspiration cytology (FNAC) (60.5%) and core biopsy (90.8%). Combining the three modalities of clinical examination, imaging and cyto/pathology increased the pre-operative detection rate of ILC.

CONCLUSION

Triple assessment is useful in the diagnosis of ILC. As the features of ILC may be subtle, a high index of suspicion is required to facilitate early diagnosis.

Role of chest radiography after the insertion of a subclavian vein catheter for ambulatory chemotherapy

OBJECTIVE

To determine the need for routine chest radiography after the insertion of a catheter via the subclavian vein for ambulatory chemotherapy.

METHODS

The case notes of all patients who had undergone catheter insertion between 1994 and 1998 were reviewed retrospectively.

RESULTS

Of 3844 cases, there were 52 (1.4%) complications detected on chest radiographs after catheter insertion, 46 of which were pneumothoraces; 15 of the 46 patients had a clinical risk factor at insertion (technical difficulty or symptoms), and 14 had a risk factor after insertion (respiratory symptoms and signs). For 22 (47.8%) pneumothoraces, there was no clinical risk factor identified; 3 of these patients required intercostal drain insertion. Other complications (n = 6) included catheter malposition and kinking, and chest radiography made an important contribution to management in at least 1 of these cases.

CONCLUSION

In approximately 0.1% of cases of catheter insertion in the subclavian vein, chest radiography detected a clinically occult complication significant enough to require intervention.

The use of ultrasound by breast surgeons in outpatients: an accurate extension of clinical diagnosis

AIMS

To assess the accuracy of breast ultrasound scan (USS) performed by a surgeon in outpatients and to evaluate the additional contribution of USS to clinical diagnosis.

METHODS

A prospective study of 302 patients with symptomatic breast disease (322 lumps) was performed. Group 1 consisted of 213 clinic USS of lumps surgically removed for appropriate clinical indications. In Group 2, a USS was performed on 231 lumps by both the surgeon and radiologists as part of triple assessment. Each clinic USS was compared to the surgical pathology (Group 1) or USS performed by the radiologist (Group 2).

RESULTS

In Group 1 (n=213), 89 lumps were proven benign and 124 malignant on histology. Ultrasound scans performed by the surgeon compared to histology had a sensitivity of 98.3% and specificity of 91.7%. An abnormal clinic USS heightened the index of suspicion in 22/213 (10.3%) of cases felt clinically to be benign but subsequently confirmed malignant on histology. Fifty-seven lumps felt to be indeterminate clinically were correctly identified on USS by surgeon as benign (n=56) or malignant (n=1). In Group 2 (n=231), there was complete concordance of USS scans by surgeon and radiologists in 197 (96%) and complete discordance in eight (3.9%) patients. Of the discordant scans, the surgeon correctly identified 7/8 diagnoses on histology. A USS examination by the radiologists provided a correct diagnosis of 6/14 scans scored by the clinician as indeterminate.

CONCLUSION

USS performed in outpatients by a breast surgeon is accurate and a useful adjunct to clinical assessment. This enables rapid diagnosis in one-stop breast clinics, selecting difficult diagnostic procedures for USS by radiologists at the same visit.

Concentration-dependent, temperature-dependent non-Newtonian viscosity of lung surfactant dispersions

The bulk shear viscosities of aqueous dispersions of lavaged calf lung surfactant (LS) and its chloroform:methanol extract (CLSE) were measured as a function of concentration, shear rate and temperature. At 10-mg phospholipid per milliliter, dispersions of LS and vortexed CLSE in 0.15 M NaCl (saline) had low viscosities near 1 cp over a range of shear rates from 225 to 1125 s(-1). Lung surfactant viscosity increased with phospholipid concentration and became strongly non-Newtonian with higher values at low shear rates. At 37 degrees C and 40 mg/ml, LS and vortexed CLSE in saline had viscosities of 38 and 34 cp (77 s(-1)) and 12 and 7 cp (770 s(-1)), respectively. Viscosity values for LS and CLSE were dependent on temperature and, at fixed shear, were lower at 23 degrees C than at 37 or 10 degrees C. Hysteresis was also present in viscosity measurements depending on whether shear rate was successively increased or decreased during study. Addition of 5 mM Ca(2+) at 37 degrees C markedly reduced CLSE viscosity at all shear rates and decreased LS viscosity at low shear rates. Dispersion by sonication rather than vortexing increased the viscosity of CLSE at fixed shear, while synthetic phospholipids dispersed by either method had low, relatively Newtonian viscosities. The complex viscous behavior of dispersions of LS and CLSE in saline results from their heterogeneous aggregated microstructure of phospholipids and apoproteins. Viscosity is influenced not only by the aggregate surface area under shear, but also by phospholipid-apoprotein interactions and aggregate structure/deformability. Similar complexities likely affect the viscosities of biologically-derived exogenous surfactant preparations administered to patients in clinical surfactant therapy.

In vivo mutant frequency of thioguanine-resistant T-cells in the peripheral blood and lymph nodes of melanoma patients

T-cell activation by malignant melanoma would be anticipated to stimulate T-cell proliferation, which in turn has been associated with increasing the likelihood of somatic gene mutation. The purpose of this study was to test the hypothesis that in vivo hypoxanthine guanine phosphoribosyltransferase (hprt) mutant frequencies (MFs) are increased in peripheral blood T-cells from melanoma patients compared to normal controls. Assays were made of 48 peripheral blood samples from melanoma patients with stage 3 (13 patients) and stage 4 (35 patients) disease, 38 normal controls, and of nine tumor bearing lymph nodes. The mean hprt log(10)(MF) in patient peripheral blood was -4.77 (geometric mean hprt MF=17.0x10(-6)) compared to a mean hprt log(10)(MF) of -4.87 (geometric mean hprt MF=13.5x10(-6)) in controls. Although modest, this difference is statistically significant both by t-test (P=0.049) and after adjustment for covariates of age, gender, and cigarette smoking by regression analysis (P=0.001). Among the melanoma patients, the mean log(10)(MF) for the 17 patients who had received potentially genotoxic therapies was not significantly different from the mean log(10)(MF) for the 31 patients not receiving such therapies. The hprt MFs in the nine tumor bearing nodes were compared with MFs in peripheral blood from the same patients and revealed a non-significant (P=0.07) trend for increasing MFs in blood. Furthermore, analyses of T-cell receptor gene rearrangement patterns revealed hprt mutants originating from the same in vivo clone in both peripheral blood and a tumor-bearing node. The finding of elevated hprt MFs not entirely explained by genotoxic therapies in patients compared to controls can be explained either by hypermutability or in vivo T-cell activation. The similar MFs in peripheral blood and tumor bearing lymph nodes, as well as the finding of mutant representatives of the same in vivo T-cell clone in both locations, support monitoring peripheral blood to detect events in the nodes. If in vivo proliferation accounts for the current findings, the hprt deficient (hprt-) mutant fraction in blood may be enriched for T-cells that mediate the host immune response against malignant melanoma. Further studies will characterize the functional reactivity of hprt mutant isolates against melanoma-related antigens.

Behavioral management instruction of anxious clients in the dental hygiene curricula

PURPOSE

This study sought to determine the type and amount of instruction on behavioral management of anxious clients in dental hygiene curricula, the instructional differences between associate and baccalaureate programs, and the opinions of educators regarding behavioral management.

METHODS

A 19-item questionnaire was mailed to the directors of 210 dental hygiene programs who were asked to furnish information pertaining to behavioral instruction in their curricula and to express their opinions by use of a Likert scale. Data were analyzed using descriptive statistics and the chi-square and Z hypothesis tests.

RESULTS

Two mailings resulted in an overall response rate of 81%, with 170 questionnaires returned. Results revealed that 86% of programs surveyed taught behavioral management of anxious clients to their students. Types of strategies taught and percentage of programs teaching them were: information provision (96%), distraction (51%), modeling (51%), relaxation (62%), and hypnosis (7%). No significant relationships were found between associate and baccalaureate degree programs relating to the type of behavioral instruction; however, baccalaureate degree programs devoted significantly more curricular hours to this instruction. In general, the sample of dental hygiene educators held positive opinions regarding the use of behavioral management, with only 28% having had formal education in this area.

CONCLUSION

Results suggest that comprehensive instruction on behavioral management of client anxiety is not provided to students in all dental hygiene programs, even though dental hygiene educators consider this modality effective during oral health care.

Diagnosis and management of male breast enlargement in patients with HIV/AIDS

There have been several recent reports describing gynecomastia in HIV-1-seropositive patients treated with HAART. However, the etiology of gynecomastia in this setting is far from clear. In this article, we describe the main issues in diagnosis and treatment of gynecomastia and stress the importance of differentiating between "true" gynecomastia and "lipomastia" (pseudogynecomastia), characterized by subcutaneous fat deposition. The importance of switching antiretroviral drugs is also discussed. In addition, newer medical therapies are highlighted.

Benign metastasizing leiomyoma with intracaval leiomyomatosis

We present an unusual case of benign metastasizing leiomyoma in association with intracaval leiomyomatosis. To our knowledge, this is the first reported case of metastasizing leiomyoma with coexistent intravenous leiomyomatosis (IVL). Magnetic resonance imaging is useful for the diagnosis of pelvic and caval IVL.

Right atrial metastatic melanoma detected by dynamic contrast enhanced spiral CT

The use of and transoesophageal echocardiography has been well described in the diagnosis of intracardiac metastases. We present a case of a right atrial mass in a patient with metastatic melanoma which was unexpectedly detected by dynamic enhanced spiral CT. The diagnosis was subsequently confirmed by MRI. It is likely that the increasingly widespread use of spiral CT will result in a greater detection rate of intracardiac tumours.

Ultrasound diagnosis of metastatic melanoma of the gallbladder

The abdominal ultrasound examinations of 464 patients with malignant melanoma performed over a 3 year period were reviewed. 23 (5.2%) had soft tissue material attached to the gallbladder wall and projecting into the lumen. Four of these were polyps of less than 1 cm which were thought to be benign, while the remaining 19 had abnormalities likely to be metastatic melanoma. Upper abdominal ultrasound examinations are frequently requested for staging purposes in patients with thick high grade malignant melanoma or clinical suspicion of metastases. Ultrasound clearly identifies the gallbladder and biliary tree in the vast majority of patients and is generally regarded as the imaging modality of choice for suspected gallbladder pathology. As autopsy studies have confirmed the incidence of gallbladder metastases from malignant melanoma to be 15-20%, a careful review of the gallbladder is advocated when abdominal ultrasound examinations are performed on patients with malignant melanoma.

Imaging of small cell carcinoma of the male urogenital tract

Five cases of small cell carcinoma (three of the prostate and two of the bladder) are described to illustrate the unusual behaviour of these tumours. Cerebral, hepatic and bulky lymph node spread with large volume local disease occurred. The role the radiologist may play in these diseases is discussed.

Dual expression of human leukocyte antigen molecules and the B7-1 costimulatory molecule (CD80) on human melanoma cells after particle-mediated gene transfer

The aim of this study was to determine if human melanoma cells could be molecularly modified by particle-mediated gene transfer with a "gene gun", using genes for interferon-gamma (IFN-gamma), the B7-1 costimulatory molecule (CD80), and human leukocyte antigen (HLA)-A2, to augment expression of both HLA molecules and B7-1. Established and early passage melanoma cells transfected with human IFN-gamma complementary DNA (cDNA) produced IFN-gamma (50-5,000 pg/mL). The biological effect of this IFN-gamma transgene included an upregulation, or de novo appearance, of HLA expression. These melanoma cells had no detectable baseline surface expression of the B7-1 costimulatory molecule, but 8% to 31% of these cells became B7-1 positive with no selection procedure after gene transfer with human B7-1 cDNA. After combination gene transfer with cDNAs for both IFN-gamma and B7-1, 9% to 33% of these cells expressed both HLA-DR and B7-1. In combination gene transfer experiments with cDNAs for both HLA-A2 and B7-1, dual expression of HLA-A2 and B7-1 was achieved in 10% to 17% of the melanoma cells. Thus, the molecular modification of human melanoma cells to increase expression of both HLA and B7-1 can be achieved by particle-mediated gene delivery and presents a promising strategy to stimulate antimelanoma T-cell immunity. Key words: Melanoma; T cells; B7-1 costimulatory molecule (CD80); major histocompatibility complex.

Photoemission Studies of High- T c Superconductors: The Superconducting Gap

Over the last several years there have been great improvements in the energy resolution and detection efficiency of angle-resolved photoemission spectroscopy. These improvements have made it possible to discover a number of fascinating features in the electronic structure of the high transition temperature (T(c)) superconductors: apparently bandlike Fermi surfaces, flat-band saddle points, and nested Fermi surface sections. Recent work suggests that these features, previously thought explainable only by one-electron band theory, may be better understood with a many-body approach. Furthermore, other properties of the high-T(c) superconductors, which are difficult to understand with band theory, are well described using a many-body picture. Angle-resolved photoemission spectroscopy has also been used to investigate the nature of the superconducting pairing state, revealing an anisotropic gap consistent with a d-wave order parameter and fueling the current debate over s-wave versus d-wave superconductivity.

Computed tomography, diagnosis, staging and follow-up of pure granulosa cell tumour of the ovary

Granulosa theca cell tumours represent the largest group of hormone-secreting ovarian tumours and comprise approximately 1.5% of all ovarian malignancy. However, the prognosis and behaviour of pure granulosa cell tumours have been particularly difficult to evaluate, because in previous reports they have been grouped with granulosa theca cell tumours. Consequently, their radiological features and the possible contribution of computed tomography (CT) to clinical management has not been evaluated. We report the CT appearances of 15 patients with pure granulosa cell tumours and their clinical outcome. The results suggest the possibility of a positive relationship between histological grade and FIGO stage at presentation. Large tumour volume, extensive lymph node involvement and ascites on CT are adverse prognostic features. However, patients with abdominal masses less than 9 cm in diameter, absent or small volume lymph node disease and peritoneal and liver metastases achieved complete remission, suggesting that CT can assist in identifying those patients likely to respond best to current therapeutic regimens.

Mammography in the assessment of response to medical treatment of large primary breast cancer

The sequential mammograms of 48 patients (median age: 54 years, range: 24-84 years) undergoing primary medical treatment for large operable breast cancer at this institution were reviewed, and compared to the findings at clinical assessment. Twenty-six patients underwent endocrine therapy using tamoxifen, and 22 chemotherapy (CMF or MMM). All had more than two mammograms which were reviewed blindly by two independent radiologists. Response to treatment by both evaluation modalities was recorded using WHO definitions (NC, PR, CR, PD). Some 81% of patients achieved an objective clinical response to treatment, whilst 63% showed mammographic response. Overall comparison of clinical examination with mammography showed agreement in 38 patients (79%) and disagreement in 10 (21%). Agreement in type of response but not in its degree was found in 22 cases (46%). The results suggest that in the majority of cases mammography provides a useful adjunct to clinical examination in monitoring response to primary medical treatment for breast cancer. However, radiological factors such as unchanging microcalcification, and the continuing presence of mammographic density contribute to the discrepancy with clinical response in some tumours, and the search for alternative modalities of assessment should continue.

The role of percutaneous nephrostomy in malignant urinary tract obstruction

Percutaneous nephrostomy is a well established technique for rapid relief of ureteric obstruction and improvement of renal function. However, its role in the management of renal failure resulting from advanced abdominopelvic malignancy is controversial and there are no clear guidelines to predict which patients benefit from such intervention both in terms of survival time and quality of life. To establish a protocol for selection of patients with abdominopelvic malignancy most likely to benefit from nephrostomy for renal obstruction, the medical records of 50 consecutive patients undergoing this procedure at the Royal Marsden Hospital were reviewed. The patients were divided into four groups: Group I, renal obstruction caused by a nonmalignant complication as a result of previous surgery or radiotherapy (n = 8); Group II, renal obstruction due to untreated primary malignancy (n = 16); Group III, renal obstruction from relapsed disease with a viable treatment option (n = 8); and Group IV, relapsed disease with no conventional treatment option (n = 18). There was significant benefit from percutaneous nephrostomy in Groups I-III. The overall median survival time of Group IV patients was extremely poor: 38 days (range 6-143 days) with no long-term survivors. The results suggest that strict selection criteria should be applied to patients with a history of abdominopelvic malignancy before proceeding to percutaneous nephrostomy. No worthwhile benefit is obtained if nephrostomy is used as a palliative measure in the absence of definitive treatment.

Case report: intra-ureteric metastasis from testicular teratoma

The case report of a patient found to have intra-ureteric metastatic teratoma is presented. This has not to our knowledge previously been reported in the literature.

In-vitro resistance to zidovudine and alpha-interferon in HIV-1 isolates from patients: correlations with treatment duration and response

OBJECTIVE

To measure in-vitro antiviral drug susceptibilities of human immunodeficiency virus type 1 (HIV-1) isolates recovered from patients treated with alpha-interferon or zidovudine and patients not treated with these drugs and to examine the relation of these susceptibility measurements to duration of therapy, disease stage, and response to alpha-interferon therapy.

DESIGN

Cross-sectional study.

SETTING

Outpatient HIV clinic.

PATIENTS

Twenty-six ambulatory HIV-1-infected patients: Fifteen of these patients were receiving alpha-interferon therapy, and 11 had never received such therapy. Nine patients were participating in a clinical trial of combination therapy with zidovudine and alpha-interferon.

MEASUREMENTS

The 50% inhibitory concentration (IC50) of zidovudine and alpha-interferon was determined for HIV-1 isolates recovered from each patient. Plasma concentrations of HIV-1 p24 antigen in the nine patients in the clinical trial were measured monthly after alpha-interferon was added to zidovudine monotherapy.

RESULTS

Zidovudine IC50 (range, 0.01 to 4.87 microM) increased steadily with duration of zidovudine therapy (r = 0.57, P = 0.003). In contrast, alpha-interferon IC50 (range, 0.8 to 415 units/mL) was not related to duration of alpha-interferon treatment; in fact, high IC50s were found in isolates from patients who had never received exogenous alpha-interferon therapy. Resistance to alpha-interferon was greater in isolates from the 15 patients with the acquired immunodeficiency syndrome (AIDS) (median, 104 units/mL) than in those from the 10 patients without AIDS (median, 50 units/mL). Interferson activity was detected in plasma samples from 23 of 24 patients and was also at higher levels in patients with AIDS than in HIV-infected patients without AIDS. Reductions in plasma concentrations of HIV-1 p24 antigen in nine patients after beginning alpha-interferon therapy were greater in those with more susceptible isolates (r = -0.72, P = 0.03).

CONCLUSIONS

Interferon resistance, possibly due to endogenous interferon, is not related to duration of interferon therapy but may limit the effectiveness of interferon therapy. Determinations of interferon susceptibility may identify patients most likely to benefit from this agent.

Immunogenicity, antigenicity, and endothelial viability of aortic valves preserved at 4 degrees C in a nutrient medium

In patients undergoing aortic valve replacement, allograft valves stored at 4 degrees C in a nutrient medium have been associated with excellent immediate and long-term results. The effects of this method of prolonged storage on the antigenic, immunological and cellular characteristics of these grafts are incompletely understood. This study was designed to study these phenomena in rat aortic valves subjected to antibiotic sterilization and stored for up to 3 weeks in RPMI containing 10% fetal calf serum. Selected valves from Brown Norway rats were implanted heterotopically into the abdominal aorta of Lewis rats. Other valves were studied prior to transplantation. Antigenicity was determined by immunocytochemical staining using monoclonal mouse antibodies directed at Class I and Class II rat antigens. Immunogenicity was determined by duration of second-set skin graft survival following heterotopic aortic valve implant. Endothelial cell viability was determined by flow cytometric analysis of endothelial cells harvested from aortic valve allografts by collagenase digestion. Only fresh valves and valves stored for 1 day were positive for Class I antigens; no valves were positive for Class II antigens. Duration of skin graft survival was prolonged with greater duration of storage, but grafts remained immunogenic after 21 days of storage. Endothelial cell viability declined from 95% in the fresh valves to 64% after 21 days of storage. With prolonged duration of allograft valve storage at 4 degrees C, there is an attenuation of antigenicity, immunogenicity, and endothelial cell viability. Loss of endothelial cells may contribute to the changes in immunological responses to the valve allografts. The expression of antigens on the endothelial surface is not a reliable predictor of immunological response.

Resistance to ddI and sensitivity to AZT induced by a mutation in HIV-1 reverse transcriptase

Serial human immunodeficiency virus type-1 (HIV-1) isolates were obtained from five individuals with acquired immunodeficiency syndrome (AIDS) who changed therapy to 2',3'-dideoxyinosine (ddI) after at least 12 months of treatment with 3'-azido-3'-deoxythymidine (zidovudine, AZT). The in vitro sensitivity to ddI decreased during the 12 months following ddI initiation, whereas AZT sensitivity increased. Analysis of the reverse transcriptase coding region revealed a mutation associated with reduced sensitivity to ddI. When this mutation was present in the same genome as a mutation known to confer AZT resistance, the isolates showed increased sensitivity to AZT. Analysis of HIV-1 variants confirmed that the ddI resistance mutation alone conferred ddI and 2',3'-dideoxycytidine resistance, and suppressed the effect of the AZT resistance mutation. The use of combination therapy for HIV-1 disease may prevent drug-resistant isolates from emerging.

Imaging properties of polydioxanone and titanium ligating clips following para-aortic lymphadenectomy for testicular cancer

Stainless steel ligating clips produce serious artefacts on CT scans. Polydioxanone (PDS) and titanium ligating clips were used in 15 patients during para-aortic lymphadenectomy for residual metastatic testicular teratoma following chemotherapy, and follow-up CT images were compared with those following the use of stainless steel ligating clips. PDS ligating clips did not produce any artefacts and were progressively absorbed. Titanium ligating clips produced artefacts similar to but less intense than those of stainless steel. PDS ligating clips should be used when follow-up CT scanning is important.

Binding of epidermal growth factor to its receptor is affected by membrane phospholipid environment

Cells of epithelial origin generally require ethanolamine to grow in culture; when these cells are grown without ethanolamine, the phosphatidylethanolamine content of their membrane phospholipid becomes 1/2 to 1/3 of the normal amount, and growth stops. We have hypothesized that growth ceases because the phospholipid environment becomes unsuitable for membrane-associated function. Using ethanolamine-requiring rat mammary cells, we have investigated the possible effect of phosphatidylethanolamine deficiency on the binding characteristics of epidermal growth factor. Apparent dissociation constant for the high-affinity sites in cells having normal membrane phospholipid was 1.7 X 10(-10) M, whereas that of phosphatidylethanolamine-deficient cells was 2.7 X 10(-10) M: the difference was small, but significant. Pretreatment with phorbol ester caused the loss of high-affinity sites in cells having normal membrane, whereas binding characteristics of epidermal growth factor became refractory to the pretreatment in phosphatidylethanolamine-deficient cells. In addition, the rate of internalization of bound epidermal growth factor in phosphatidylethanolamine-deficient cells was about 1/4 of normal cells. Further, whether cells had normal or phosphatidylethanolamine-deficient membranes seemed to affect the phosphorylation patterns of membrane proteins in response to epidermal growth factor or phorbol ester. These results suggest that membrane phospholipid environment affects the activity of the epidermal growth factor receptor.

Preoperative cytology and mammography in patients with single-duct nipple discharge treated by surgery

Microdochectomy has been the routine management for single-duct nipple discharge. Our review of 176 consecutive patients surgically treated between 1975 and 1988 revealed eight patients with in situ carcinomas and seven with infiltrative carcinomas. Seventeen patients had multiple papillomas, two had atypical hyperplasia and two had atypical epitheliosis. Case selection for surgery has recently been advocated. In our study, nipple discharge cytology was helpful in 67 per cent of cases with underlying malignant pathology. Mammography was found to be unreliable, alerting suspicion in only two of 15 cases.

Gentamicin iontophoresis in the treatment of bacterial otitis externa in the guinea pig model

Pseudomonas otitis externa is one of the most common infections treated by otolaryngologists. Infections induced in 30 guinea pigs appeared similar to that seen in humans. The ears were then placed into four treatment groups: group A, which received a single cleaning; group B, which received a single cleaning followed by gentamicin drops 4 times daily; group C, which received a single cleaning followed by a single gentamicin iontophoresis treatment; and group D, the control group, which received no treatment. Infections were analyzed by grading edema, purulence, and erythema. An average of 10.2 days was required for control group to return to normal appearance. Groups A, B, and C had mean resolution times of 5.9, 4.7, and 4.3 days, respectively. Gentamicin iontophoresis appears to be promising, with results as good as drop therapy in otitis externa in the guinea pig model.