Prognostic value of plasma circulating tumor DNA fraction across four common cancer types: a real-world outcomes study

BACKGROUND

Genomic analysis of circulating tumor DNA (ctDNA) is increasingly incorporated into the clinical management of patients with advanced cancer. Beyond tumor profiling, ctDNA analysis also can enable calculation of circulating tumor fraction (TF), which has previously been found to be prognostic. While most prognostic models in metastatic cancer are tumor type specific and require significant patient-level data, quantification of TF in ctDNA has the potential to serve as a pragmatic, tumor-agnostic prognostic tool.

PATIENTS AND METHODS

This study utilized a cohort of patients in a nationwide de-identified clinico-genomic database with metastatic castration-resistant prostate cancer (mCRPC), metastatic breast cancer (mBC), advanced non-small-cell lung cancer (aNSCLC), or metastatic colorectal cancer (mCRC) undergoing liquid biopsy testing as part of routine care. TF was calculated based on single-nucleotide polymorphism aneuploidy across the genome. Clinical, disease, laboratory, and treatment data were captured from the electronic health record. Overall survival (OS) was evaluated by TF level while controlling for relevant covariables.

RESULTS

A total of 1725 patients were included: 198 mCRPC, 402 mBC, 902 aNSCLC, and 223 mCRC. TF ≥10% was highly correlated with OS in univariable analyses for all cancer types: mCRPC [hazard ratio (HR) 3.3, 95% confidence interval (CI) 2.04-5.34, P < 0.001], mBC (HR 2.4, 95% CI 1.71-3.37, P < 0.001), aNSCLC (HR 1.68, 95% CI 1.34-2.1, P < 0.001), and mCRC (HR 2.11, 95% CI 1.39-3.2, P < 0.001). Multivariable assessments of TF had similar point estimates and CIs, suggesting a consistent and independent association with survival. Exploratory analysis showed that TF remained consistently prognostic across a wide range of cutpoints.

CONCLUSIONS

Plasma ctDNA TF is a pragmatic, independent prognostic biomarker across four advanced cancers with potential to guide clinical conversations around expected treatment outcomes. With further prospective validation, ctDNA TF could be incorporated into care paradigms to enable precision escalation and de-escalation of cancer therapy based on patient-level tumor biology.

Skin Lesions in Neurofibromatosis Type 2: Diagnostic and Prognostic Significance of Cutaneous (Plexiform) Schwannomas

Background

Neurofibromatosis type 2 (NF2) is a genetic disease characterized by the appearance of multiple tumours in the nervous system. Cutaneous lesions are common and may provide useful diagnostic and prognostic information, but they have not been widely studied.

Objectives

To characterize cutaneous lesions in a Spanish cohort of patients with NF2 and investigate associations with clinical and genetic severity.

Methods

We studied the clinical and histologic characteristics of cutaneous lesions in 49 patients with NF2 and analysed correlations with phenotype‐ and genotype‐based severity scores. We collected information on the presence/absence of cutaneous lesions, location, age at onset, type of lesion, and histologic features. We also studied level of systemic involvement and genetic mutations involved.

Results

Forty‐nine patients (31 women [63.3%] and 18 men [36.7%]) were analysed, and 33 (67.3%) had cutaneous lesions presumed to be schwannomas. According to their clinical form, they were distributed as follows: 24 patients (48%) had deep tumours, 21 (42%) had plaque‐like lesions, and 3 (6%) had superficial tumours. Histologic examination from 27 lesions analysed out 23 patients showed classic schwannoma or hybrid schwannoma‐neurofibroma features in the 8 deep tumours biopsied and plexiform schwannoma features in the 17 plaque‐like lesions and the 2 superficial tumours analysed. Early onset (first 2 decades of life) was reported by all patients with plaques and superficial tumours. In our cohort, 100% of the patients with plaque‐like lesions and superficial tumours with microscopic features of plexiform schwannoma were in the 2 groups with the most severe clinical phenotypes, and 82.6% of them were in the 3 most severe genotype‐based classes.

Conclusions and Relevance

Cutaneous lesions, specially plexiform schwannomas, are common in NF2, and they usually appear at an early age providing useful diagnostic and prognostic information. These tumours are part of the spectrum of cutaneous manifestations in this disease. Although its diagnostic and prognostic value has been pointed out, there are few studies focussed on their analysis.

Validation of a Real-Time PCR for the Detection of Mycobacterium tuberculosis Complex Members in Bovine Tissue Samples

Although the post-mortem diagnosis of bovine tuberculosis is mainly achieved through microbiological culture, the development of other techniques to detect Mycobacterium tuberculosis complex (MTBC) members directly from tissue samples has been pursued. The present study describes the development, optimization and validation of a Real-Time PCR based on the mpb70 gene to detect MTBC members in clinical tissue samples from cattle. Specific primers and a hybridization probe were used to amplify MTBC-specific sequences in order to avoid cross-reaction with non-MTBC species. An Internal Amplification Control (IAC) was included in order to assess the presence of PCR inhibitors in the samples. The PCR was optimized to achieve maximum efficiency, and the limit of detection, limit of quantification and dynamic range of the reaction were determined. The specificity of the reaction was tested against 34 mycobacterial and non-mycobacterial species. The diagnostic sensitivity, specificity and positive and negative predictive values (PPV and NPV) of the method were assessed on 200 bovine tissue samples in relation to bacteriological culture. The dynamic range of the reaction spanned from 5 ng/reaction (10⁶ genome equivalents) to 50 fg/reaction (10 genome equivalents). The efficiency of the reaction was 102.6% and the achieved R² was 0.999. The limit of detection with 95% confidence was 10 genome equivalents/reaction. No cross-reactions with non-MTBC species were observed. The diagnostic sensitivity and specificity values of the mpb70 specific Real-Time PCR respect to culture were 94.59% (95% CI: 86.73–98.51%) and 96.03% (95% CI: 90.98–98.70%), respectively, with a PPV of 93.33% (95% CI: 85.55–97.07%) and a NPV of 96.80% (95% CI: 92.10–98.74%). The concordance of the Real-Time PCR based on mpb70 is comparable to that of culture (K = 0.904) showing a great potential for the detection of members of the MTBC in animal tissues.

Abstract LB-B03: Exosome-based Detection of EGFR T790M in Plasma from Non-Small Cell Lung Cancer Patients

About 60% of non-small cell lung cancer (NSCLC) patients develop resistance to targeted epidermal growth factor receptor (EGFR) inhibitor therapy through the EGFR T790M mutation. Although these patients respond well to third generation tyrosine kinase inhibitors like osimertinib, obtaining tissue biopsies for mutation profiling poses risks and is often not feasible. Detecting the mutation in a liquid biopsy from plasma has emerged as a viable alternative to biopsy, however existing liquid biopsy tests using cell-free DNA (cfDNA) often suffer from low sensitivity due to the low copy number of mutant molecules in circulation. As an example, the Food and Drug Adminstration (FDA) approved companion diagnostic for T790M mutation status in plasma (cobas® EGFR mutation Test version 2) only has a 58% sensitivity at a specificity of 80%. In this study we aimed to achieve a higher performance by combining the mutated alleles on cfDNA as well as exosomal RNA and DNA (exoNA) .

ExoNA and cfDNA were extracted from the plasma of NSCLC patients with biopsy-confirmed T790M-positive (N = 102) or T790M-negative (N = 108) samples. The T790M mutation status in plasma exoNA and cfDNA was determined using an analytically validated allele-specific qPCR assay in a CLIA laboratory.

The training cohort consisted of 105 samples (51 positives, 54 negatives). The validation cohort consisted of 105 samples (51 positives, 54 negatives), where ~40% of the patients had intrathoracic disease(M0/M1a). Detection of the T790M mutation in exoNA and cfDNA achieved 92% sensitivity and 89% specificity when compared to tumor biopsy results in the validation cohort. We also observed a very high sensitivity (88%) in patients with intrathoracic disease (M0/M1a), patients for whom detection by liquid biopsy has been proven particularly challenging.

The combination of exoNA and cfDNA for EGFR T790M detection has a higher sensitivity and specificity compared to historical cohorts using ctDNA alone. This is especially important as it could aid giving the right treatment to patients where biopsy is not available or avoid unnecessary tumor biopsies for T790M mutation testing.

Citation Format: Elena Castellanos, Dominik G. Grimm, Vasisht Tadigotla, Stefan Bentink, James Hurley, John Healy, Patricia L. Neal, Mia Sher, Dan Baughman, Chris Karlovich, Mitch Raponi, Anne Krug, Mikkel Noerholm, Luis E. Raez, Johan Skog. Exosome-based Detection of EGFR T790M in Plasma from Non-Small Cell Lung Cancer Patients [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-B03.

A 16 kb naturally occurring genomic deletion including mce and PPE genes in Mycobacterium avium subspecies paratuberculosis isolates from goats with Johne's disease

In this study we characterise the genomic and transcriptomic variability of a natural deletion strain of Mycobacterium avium subspecies paratuberculosis (MAP) prevalent in Spanish Guadarrama goats. Using a pan-genome microarray including MAP and M. avium subspecies hominissuis 104 genomes (MAPAC) we demonstrate the genotype to be MAP Type II with a single deletion of 19 contiguous ORFs (16 kb) including a complete mammalian cell entry (mce7_1) operon and adjacent proline-glutamic acid (PE)/proline-proline-glutamic acid (PPE) genes. A deletion specific PCR test was developed and a subsequent screening identified four goat herds infected with the variant strain. Each was located in central Spain and showed epidemiological links suggestive of transmission between herds. A majority of animals infected with the variant manifested a paucibacillary form of the disease. Comparisons between virulent complete genome compliment strains isolated from multibacillary diseased goats and the MAP variant strain during entry into activated macrophages demonstrated an increased sensitivity in the variant to intracellular killing in human and ovine macrophages. As PPE and mce genes are associated with mycobacterial virulence and pathogenesis we investigated the interplay of these gene sets during cell entry using the MAPAC array. This showed significant differential transcriptome profiles compared to full genome complement MAP controls that included changes in other undeleted mce operons and PE/PPE genes, esx-like signalling operons and stress response/fatty acid metabolism pathways. This strain represents the first report of a MAP Type II genotype with significant natural genomic deletions which remains able to cause disease and is transmissible in goats.

Mycobacterium caprae infection in livestock and wildlife, Spain

Mycobacterium caprae is a pathogen that can infect animals and humans. To better understand the epidemiology of M. caprae, we spoligotyped 791 animal isolates. Results suggest infection is widespread in Spain, affecting 6 domestic and wild animal species. The epidemiology is driven by infections in caprids, although the organism has emerged in cattle.

Molecular characterization of Mycobacterium avium subspecies paratuberculosis Types II and III isolates by a combination of MIRU-VNTR loci

Mycobacterial interspersed repetitive units and variable number tandem repeats typing (MIRU-VNTR) is a useful technique that has been recently applied to characterize members of the Mycobacterium avium complex (MAC). The aim of this study was to examine the genetic variability among a collection of Spanish M. avium subspecies paratuberculosis (M. a. paratuberculosis) isolates with a combination of MIRU-VNTR loci. For this purpose we tested six MIRU-VNTR loci (MIRU-2, MIRU-3, VNTR-25, VNTR-32, VNTR-292 and VNTR-259) in 70 M. a. paratuberculosis isolates of Types II and III that were recovered from 22 Spanish localities during a nine-year period (1998-2007). The combination of five loci (MIRU-2, MIRU-3, VNTR-25, VNTR-32 and VNTR-259) enabled the differentiation of 12 allelic profiles, with a resulting Hunter and Gaston discriminatory index (HGDI) of 0.84. Moreover, we obtained MIRU-VNTR patterns that were unique for each of the M. a. paratuberculosis types analyzed (II and III); other patterns were host-related or restricted to geographic areas. Therefore, this MIRU-VNTR approach could be a useful sub-typing molecular tool in order to get a better sense of the epidemiology of Johne's disease.

Polymorphisms in gyrA and gyrB genes among Mycobacterium avium subsp. paratuberculosis type I, II, and III isolates

The analysis of the gyrA and gyrB genes of a panel of Mycobacterium avium subsp. paratuberculosis isolates from types I, II, and III detected type-specific single nucleotide polymorphisms. Based on these results, we developed a PCR and restriction enzyme analysis to discriminate type I and III isolates. The application of this technique would be the unique strategy to characterize these strains when there is not enough bacterial growth to perform pulsed-field gel electrophoresis and IS900 restriction fragment length polymorphism.

Cyclic modular beta-sheets

The development of peptide beta-hairpins is problematic, because folding depends on the amino acid sequence and changes to the sequence can significantly decrease folding. Robust beta-hairpins that can tolerate such changes are attractive tools for studying interactions involving protein beta-sheets and developing inhibitors of these interactions. This paper introduces a new class of peptide models of protein beta-sheets that addresses the problem of separating folding from the sequence. These model beta-sheets are macrocyclic peptides that fold in water to present a pentapeptide beta-strand along one edge; the other edge contains the tripeptide beta-strand mimic Hao [JACS 2000, 122, 7654] and two additional amino acids. The pentapeptide and Hao-containing peptide strands are connected by two delta-linked ornithine (deltaOrn) turns [JACS 2003, 125, 876]. Each deltaOrn turn contains a free alpha-amino group that permits the linking of individual modules to form divalent beta-sheets. These "cyclic modular beta-sheets" are synthesized by standard solid-phase peptide synthesis of a linear precursor followed by solution-phase cyclization. Eight cyclic modular beta-sheets 1a-1h containing sequences based on beta-amyloid and macrophage inflammatory protein 2 were synthesized and characterized by 1H NMR. Linked cyclic modular beta-sheet 2, which contains two modules of 1b, was also synthesized and characterized. 1H NMR studies show downfield alpha-proton chemical shifts, deltaOrn delta-proton magnetic anisotropy, and NOE cross-peaks that establish all compounds but 1c and 1g to be moderately or well folded into a conformation that resembles a beta-sheet. Pulsed-field gradient NMR diffusion experiments show little or no self-association at low ( Collapse

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MESH Headings

• Amino Acid Sequence
• Amyloid beta-Peptides/chemistry
• Chemokine CXCL2
• Chromatography, High Pressure Liquid
• Hydrogen Bonding
• Magnetic Resonance Spectroscopy
• Molecular Conformation
• Molecular Sequence Data
• Monokines/chemistry
• Oligopeptides/chemical synthesis
• Ornithine/chemistry
• Peptides, Cyclic/chemistry
• Protein Folding
• Protein Structure, Secondary
• Water/chemistry

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Grants

• R01 GM049076-12 NIGMS NIH HHS
• 5T32 CA 009054 NCI NIH HHS
• R01 GM049076-13 NIGMS NIH HHS
• T32 CA009054 NCI NIH HHS
• GM 49076 NIGMS NIH HHS
• R01 GM049076 NIGMS NIH HHS
• 5T15 LM 07443 NLM NIH HHS
• R01 GM049076-11 NIGMS NIH HHS
• T15 LM007443 NLM NIH HHS

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Affiliation(s)

R. Jeremy Woods Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920
Justin O. Brower Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920
Elena Castellanos Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920
Mehrnoosh Hashemzadeh Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920
Omid Khakshoor Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920
Wade A. Russu Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920
James S. Nowick Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, Phone: 949-824-6091, FAX: 949-824-9920

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Comparison of four different culture media for isolation and growth of type II and type I/III Mycobacterium avium subsp. paratuberculosis strains isolated from cattle and goats

Culture is considered the definitive technique for Johne's disease diagnosis, and it is essential for later applications of certain molecular typing techniques. In this study, we have tested four solid media (Herrold's egg yolk medium [HEYM] with sodium pyruvate and mycobactin [HEYMm-SP], HEYM with mycobactin and without sodium pyruvate [HEYMm], Middlebrook 7H11 with mycobactin [Mm], and Löwenstein-Jensen with mycobactin [LJm]) for isolation of Mycobacterium avium subsp. paratuberculosis strains in 319 tissue samples from cattle herds and goat flocks. We have shown that each of the two main groups of M. avium subsp. paratuberculosis (type II and type I/III) has different requirements for growth in the culture media studied. The recommended solid media for isolation of type I/III strains are LJm and Mm, since the combination of both media allowed the recovery of all these strains. The most widespread culture medium, HEYM, is not suitable for the isolation of this group of M. avium subsp. paratuberculosis strains. Regarding the type II strains, HEYMm-SP was the medium where more strains were isolated, but the other three media are also needed in order to recover all type II strains. The incubation period is also related to the strain type. In conclusion, because the type of strain cannot be known in advance of culture, coupled with the fact that cattle and goats can be infected with both groups of strains, we recommend the use of the four solid media and the prolongation of the incubation period to more than 6 months to detect paratuberculous herds/flocks and to determine the true prevalence of the infection.

Mediastinal paraganglioma irrigated by coronary vessels in a patient with an atypical chest pain

We present a case of non-functioning anterior mediastinal paraganglioma in a 61-year-old woman. The tumour was accidentally discovered on a coronary angiography performed in an atypical precordial pain and dyspnea. The coronary angiography showed a vascular tumour in the paraaortic localization irrigated from two branches of coronary arteries. Diagnosis was confirmed by a thoracic tomographic scan which revealed an anterior mediastinal tumour. Complete tumour resection was done through a sternotomy with extracorporeal circulation without cardiac arrest. The histological examination of the operative specimen was characteristic of paraganglioma.

The role of mast cell tryptase in neoangiogenesis of premalignant and malignant lesions of the uterine cervix

Recently, mast cell tryptase has been identified as another potent proangiogenic factor in tumors, along with fibroblast and vascular endothelial growth factors. Its role has been studied in a number of cancers, including carcinoma of the uterine cervix, with discordant results. Our aim was to study the expression of tryptase and bFGF in mast cells (MCs) during development of neoangiogenesis in premalignant and malignant lesions of the cervix. Biopsy specimens from 21 patients without cancer and from 63 patients with dysplasias and squamous cell carcinomas were used. They were stained with Alcian blue-safranin O (ABSO) and immunostained with specific antibodies against factor VIII, CD105, tryptase, and bFGF. Tryptase-positive mast cells increased with tumor progression and were close to newly formed blood vessels. Vascularization showed a linear increase from dysplasia to invasive cancer. We suggest that MC tryptase may upregulate neoangiogenesis in carcinogenesis of the uterine cervix.

[Ventricular arrhythmias induced by appropriate antibradycardia pacing in patients with implantable defibrillators]

INTRODUCTION AND OBJECTIVES

The induction of ventricular arrhythmias by appropriate antibradycardia ventricular pacing in patients with implantable cardioverter defibrillators has been reported in only a few cases. The aim of this study was to assess the incidence, characteristics and management of these episodes.

METHODS

The follow-up records of 180 patients with implantable cardioverter defibrillators with intracardiac electrogram storage were reviewed. Pacing induced episodes were defined as those occurring immediately after an appropriate paced stimulus in a patient with sporadic paced beats. We assessed the number and type of episodes, mode of onset, therapy administered and the efficacy of different prevention measures.

RESULTS

Pacing induced episodes were found in 9 patients (5%). Seven received device administered therapy which was effective in all cases. One to 95 episodes were observed per patient, of which 138 were monomorphic ventricular tachycardias and 20 polymorphic ventricular tachycardia/ventricular fibrillation episodes. All were induced by a paced ventricular beat after a post-extrasystolic pause or after long RR intervals during atrial fibrillation. Pacing induced arrhythmias were prevented by changing the pacing rate or hysteresis in 3 out of 6 patients and by decreasing the stimulus energy in 3 out of 3. Antibradycardia pacing function was disabled in 4 patients.

CONCLUSIONS

Ventricular arrhythmias induced by appropriate antibradycardia ventricular pacing are relatively common in patients with implantable cardioverter defibrillators. Effective prevention can be achieved in most cases by changing the pacing rate or the pacing stimulus energy, however in selected cases the antibradycardia function may be disabled.

Human immunodeficiency virus infection in pregnant women, transmission and zidovudine therapy

OBJECTIVE

To determine the rate of mother to child transmission of HIV infection in women treated with zidovudine (ZDV).

PATIENTS AND METHODS

A consecutive series of 52 HIV-positive pregnant women who either received antenatal care or delivered at our institution. Forty-three women were known to be HIV positive before delivery. Forty were treated with ZDV, 36 intravenously. Twelve had no antenatal care and one refused antenatal treatment. All neonates were treated with ZDV.

RESULTS

The HIV transmission rate in children born to mothers treated with ZDV was 6.6%. This compares with a transmission rate of 14% before we used ZDV. All three mothers who transmitted infection had low compliance, initiated therapy late in pregnancy or had advanced disease.

CONCLUSION

Our experience supports the idea that ZDV treatment has reduced HIV transmission rate.

Neuronal differentiation of chromaffin cells in vitro, induced by extremely low frequency magnetic fields or nerve growth factor: a histological and ultrastructural comparative study

The application of nerve growth factor (NGF) to primary adrenal medulla chromaffin cell cultures induces phenotypic changes characterized mainly by the presence of neurites. A similar effect has been seen when these cells are stimulated by extremely low frequency magnetic fields (ELFMF). In this study, newborn rat chromaffin cells were cultured and subjected to NGF or ELFMF in order to compare their histological and ultrastructural characteristics. Cells cultured in the presence of NGF developed cytoplasmic projections and their distal ends showed growth cones as well as filopodia. With scanning and transmission electron microscopy, an increased submembranous electron density was observed in the nuclei of cells as well as irregular, wavy neuritic projections with a moderate number of varicosities, as well as the prevalence of intermediate filaments among the cytoskeleton components. Cells stimulated with ELFMF presented straighter neuritic extensions with a greater number of varicosities. With the transmission electron microscope, numerous neurotubules were observed, both in the cell soma and in their neuritic extensions. In both groups, growth cones were clearly identified by their ultrastructural characteristics. The differences seen in the cytoskeleton of cells stimulated with NGF or ELFMF suggest differential stimulation mechanisms possibly determining the biochemical, electrophysiological, and morphological characteristics in both types of cell cultures.

First postpacing interval variability during right ventricular stimulation: a single algorithm for the differential diagnosis of regular tachycardias

BACKGROUND

Failure to differentiate supraventricular from ventricular arrhythmias is the most frequent cause of inappropriate implantable cardioverter-defibrillator therapies. Although a sudden-onset criterion is available to differentiate sustained monomorphic ventricular tachycardias (SMVTs) and sinus tachycardias (STs), SMVTs arising during ST and SMVTs gradually accelerating above the cutoff rate can remain undetected. Regular paroxysmal atrial tachycardias (ATs) also can be undetected by onset and stability algorithms. We hypothesized that the first postpacing interval (FPPI) variability after overdrive right ventricular pacing may differentiate SMVTs from STs and ATs.

METHODS AND RESULTS

FPPI variability was measured in 23 SMVTs (cycle length [CL] 366+/-50 ms [VT group]), 27 supraventricular tachycardias, 15 episodes of induced or simulated ATs (CL 376+/-29 ms [AT group]), and 12 exercise-related STs (CL 381+/-24 [ST group]). Sequences of trains of 5, 10, and 15 beats were delivered with a CL 40 ms shorter than the tachycardia CL. An FPPI absolute mean difference between consecutive trains of 5 and 10 beats (deltaFPPI) < or =25 ms identified all VTs (mean difference 5+/-7 ms). In the AT group, the deltaFPPI was >25 ms in all sequences (mean difference 129+/-60 ms, P<0.01). In the ST group, the deltaFPPI was >50 ms in all STs (mean difference 118+/-47 ms, P<0.01).

CONCLUSIONS

FPPI variability may differentiate SMVT from AT and ST. This criterion is potentially useful in implantable devices that use a single ventricular lead.

Cytologic atypia. Clinical significance and follow-up recommendations

OBJECTIVE

To assess the evolution of cytologic atypia on cervical cytologic smears as an attempt to better understand the natural history of these lesions and to establish a follow-up protocol.

STUDY DESIGN

The study group consisted of 76 patients with a diagnosis of cytologic atypia on cervical cytologic smears performed at the gynecology Outpatient Clinic, Hospital del Mar, between December 1989 and June 1993. Patients with inflammatory atypia, a reparative process or findings consistent with human papillomavirus infection had been excluded. Follow-up smears were reviewed. Compliance with follow-up recommendations was also evaluated.

RESULTS

Thirty-nine patients returned to the clinic for follow-up after a diagnosis of atypia (51.3%). Progression from atypia to dysplasia was found in 38.5% of patients with at least a follow-up smear. Changes consistent with intraepithelial neoplasia were found in 17 patients: low grade dysplasia was found in 10 patients (mild dysplasia in 8 and atypia in 2) and high grade dysplasia in 7 (moderate in 4 and severe in 3). This progression was most commonly found at the first follow-up visit and within the first year.

CONCLUSION

Patients with cytologic atypia were at higher risk of developing dysplasia than those with reparative atypia. Our results support the theory of progression from atypia to dysplasia in a considerable percentage of patients. Follow-up compliance in our patient population was low. One should emphasize the importance of this diagnosis and encourage close cytologic follow-up, especially within the first year after the diagnosis of atypia.

Intermittent aortic regurgitation following aortic valve replacement

Intermittent aortic regurgitation is an unusual complication following a mechanical prosthesis replacement in the early postoperative period. Arterial pressure recording and echocardiographic assessment were enough to diagnose the prosthetic dysfunction. Reexploration of the valve confirmed the dysfunction, which was caused by a pannus of previous aortic valve replacement with the pulmonary valve. The pannus impeded normal closure of the leaflet in an intermittent way during diastole. Reorientation of the valve corrected the aortic insufficiency. Doppler ultrasound was a very useful noninvasive technique in order to evaluate the suspected prosthetic valve dysfunction in the immediate postoperative period.

Hyperammonaemic encephalopathy as the presenting feature of IgD multiple myeloma

We observed a case of hyperammonaemic encephalopathy in a patient without liver dysfunction which revealed meningeal involvement of IgD multiple myeloma. We have reviewed briefly the hyperammonaemic syndrome and we believe that this diagnosis has to be considered in differential diagnosis of encephalopathies in patients with multiple myeloma.

A comparative study of the St. Jude Medical and Björk-Shiley convexo-concave prostheses in isolated valve replacement

This is a study of 199 consecutive patients who survived isolated mitral or aortic valve replacement with a Björk-Shiley (B-S) or St. Jude Medical (SJM) prostheses. Mean follow-up was 36 months. Preoperative status was similar for both groups (B-S or SMJ). Five year survival rates for mitral valve replacement (MVR) were 91% for B-S and SJM, and for aortic valve replacement (AVR) 96% vs 91% for SJM (p less than 0.06). Linearized incidence of thromboembolism in MVR was 5.62% patient year for BS and 5.23% patient year for SJM (p = NS). Classical risk factors for thromboembolism were evaluated on a univariate analysis: no single risk factor was identified. Only the association of two or more was possibly significant. The presence of inadequate anticoagulation (prothrombin index greater than 50%) was the main risk factor for thromboembolism, as the incidence rate was 19% per patient year when poorly anticoagulated versus 4.6% per patient year incidence in the whole series (p less than 0.01).

[The 2-dimensional and Doppler color echocardiographic study of a congenital aneurysm of the sinus of Valsalva with a fistula of the right atrium in an adult]

This report describe a 69-year old woman with a congenital aneurysm of the non-coronary sinus of Valsalva ruptured in the right atrium, causing severe hemodynamic derangement of the right ventricle. The site of the communication between the aneurysm and the receiving chamber was accurately diagnosed by two-dimensional color flow Doppler imaging which provided more valuable preoperative information than conventional aortography.

Ultrastructural studies of rat arteriosclerosis induced by stimulation of the immune system with ovalbumin

Intimal thickening in the aorta and carotid artery of rats was induced by repeated intraperitoneal injections of ovalbumin, 2.5 mg/kg BW, given weekly 5 times after initial subcutaneous sensitization, and/or feeding with a cholesterol-rich diet. The intimal thickening was apparent in immune-challenged rats fed with either a cholesterol-rich or a basal diet (p less than 0.01), whereas it was mild in non-immunized rats fed a cholesterol-rich diet. The ultrastructural changes in the thickened intima were characterized by leukocytic (mainly monocytic) adhesion and migration, and minor endothelial cell damage. Morphometric evaluation of leukocyte adhesion to the intima of the thoracic aorta revealed that the immunized rats fed either a cholesterol-rich or a basal diet showed greater leukocytic adhesion (p less than 0.01 and p less than 0.001, respectively) than that in non-immunized rats fed a cholesterol-rich diet, which in turn also showed an increased degree of leukocyte adhesion (p less than 0.05) than control rats. This immunological approach to the arteriosclerotic process could explain the earlier and more severe arteriosclerosis found in patients with immunological disorders, and the development of arteriosclerosis in the absence of hypercholesterolemia, hypertension and other risk factors.