Ultrasound-guided compression closure of postcatheterization pseudoaneurysms during concurrent anticoagulation: a review of seventy-seven patients

PURPOSE

Data from our institution and elsewhere have demonstrated that ultrasound-guided compression closure (UGCC) is an effective method of treating postcatheterization pseudoaneurysms. Whereas patients receiving anticoagulation do not have as high a success rate as those not receiving anticoagulants, there have been no large series evaluating the factors associated with success or failure in patients receiving anticoagulation. The purpose of this study is to determine whether uninterrupted anticoagulation interferes with successful UGCC of pseudoaneurysms and to identify factors associated with success or failure.

METHODS

From May 1991 to September 1994, 238 cases of attempted UGCC of pseudoaneurysms were performed in our vascular laboratory. Only patients who received uninterrupted heparin, warfarin, or both at the time of pseudoaneurysm compression were eligible for inclusion into the study. Seventy-seven patients were identified who met the study criteria.

RESULTS

Successful pseudoaneurysm compression was obtained in 56 (73%) patients, whereas 21 (27%) patients had a failed UGCC. In the successfully treated group, seven (12.5%) required between two to three compression attempts to induce sustained thrombosis. There was no statistical difference in age, sex, sheath size, days after procedure, location of pseudoaneurysm, or number of chambers in the pseudoaneurysm between those patients who had a successful repair and those who did not. If the pseudoaneurysm was less than 4 cm in diameter, 51 of 65 patients (78%) had a successful repair compared with 5 of 12 patients (42%) with a pseudoaneurysm of 4 cm or greater (p = 0.013). There was no statistical difference between success and failure in patients receiving warfarin alone (3.73 mean international normalized ratio, 72% success rate), heparin alone (mean activated partial thromboplastin time of 63 seconds, 92% success rate), or heparin and warfarin (mean activated partial thromboplastin time of 70 seconds, mean international normalized ratio of 4, success rate of 67%). No arterial or venous thrombosis occurred during pseudoaneurysm compression.

CONCLUSION

Successful UGCC of pseudoaneurysms occurred in a large percentage of patients receiving full-dose, uninterrupted anticoagulation. The only factor influencing success was the size of the pseudoaneurysm.

Selection of specific phage-display antibodies using libraries derived from chicken immunoglobulin genes

In chickens, single functional immunoglobulin variable and joining gene segments at each of the heavy and light chain loci undergo V(D)J rearrangement. Diversity is subsequently introduced by conversions templated by upstream pseudo V region genes in such a way that practically all V regions in mature B cells have identical ends. This greatly simplifies the representative amplification of V region genes. Furthermore, the entire naive repertoire of the adult chicken is produced in the bursa of Fabricius of the young bird. These special properties of the generation of immunoglobulin diversity in chickens have been exploited in the development of procedures to produce large libraries of diverse antibody combining sites derived from chicken Ig genes and expressed on filamentous bacteriophage. The utility of this library was assessed by selection of specifically binding phage using three solid phase-bound protein antigens, hen egg white lysozyme, bovine thyroglobulin and bovine serum albumin. The sequences of the V region genes thus isolated demonstrated that selection was specific and that the library contained useful diversity of binding sites. This library provides access to a repertoire whose diversity is based on a mechanism different from that underlying previously available libraries. The demonstrated feasibility of generating chicken phage antibodies may lead to the production of monoclonal reagents from immunised chickens, and the derivation of reagents for studying immunoglobulin mediated selection in avian B cell development.

Identification of a novel class of mammalian Fc gamma receptor

A cDNA encoding an Ig receptor that conferred the ability to bind erythrocytes sensitized with IgG2, but not IgG1, was cloned by screening a cattle alveolar macrophage library, made in the vector pCDM8, expressed in COS-7 cells. A search of the PIR database indicated a greater level of similarity with human Fc alpha R than with any other FcR. The percentage of identical amino acids was 41% and nucleotides 56%. This high similarity is between the extracellular and transmembrane domains; the cytoplasmic tails are unrelated. Similarities with human Fc gamma RI, Fc gamma RII, Fc gamma RIII, Fc epsilon RI, or bovine Fc gamma RII were less than 28%. COS-7 cells transfected with the cloned plasmid bound erythrocytes specifically sensitized with IgG2 but not with IgG1. In tests with heat-aggregated bovine Igs, IgG2 purified from serum bound to transfected COS-7 cells but IgG1 from serum and IgA from tracheobronchial secretions did not. Human serum IgA also failed to bind to transfected COS-7 cells although it did bind to bovine neutrophils and monocytes. Only aggregated bovine IgG2 inhibited the binding of IgG2-sensitized erythrocytes to COS-7 cells transfected with the plasmid. These observations indicate that the FcR bound IgG2 specifically and was not a receptor for IgA. Thus, this receptor, which we have named bovine Fc gamma 2R, represents a novel class of mammalian Fc gamma R, the evolution of which is likely to have been influenced by the truncated hinge of the bovine IgG2 molecule. Analysis of genetic divergence of the genes encoding bovine and human Fc gamma R and Fc alpha R indicated that the novel bovine gene and the human Fc alpha R gene probably evolved from a common ancestor, which is not shared by other Fc gamma R.

Identification of a novel class of mammalian Fc gamma receptor

A cDNA encoding an Ig receptor that conferred the ability to bind erythrocytes sensitized with IgG2, but not IgG1, was cloned by screening a cattle alveolar macrophage library, made in the vector pCDM8, expressed in COS-7 cells. A search of the PIR database indicated a greater level of similarity with human Fc alpha R than with any other FcR. The percentage of identical amino acids was 41% and nucleotides 56%. This high similarity is between the extracellular and transmembrane domains; the cytoplasmic tails are unrelated. Similarities with human Fc gamma RI, Fc gamma RII, Fc gamma RIII, Fc epsilon RI, or bovine Fc gamma RII were less than 28%. COS-7 cells transfected with the cloned plasmid bound erythrocytes specifically sensitized with IgG2 but not with IgG1. In tests with heat-aggregated bovine Igs, IgG2 purified from serum bound to transfected COS-7 cells but IgG1 from serum and IgA from tracheobronchial secretions did not. Human serum IgA also failed to bind to transfected COS-7 cells although it did bind to bovine neutrophils and monocytes. Only aggregated bovine IgG2 inhibited the binding of IgG2-sensitized erythrocytes to COS-7 cells transfected with the plasmid. These observations indicate that the FcR bound IgG2 specifically and was not a receptor for IgA. Thus, this receptor, which we have named bovine Fc gamma 2R, represents a novel class of mammalian Fc gamma R, the evolution of which is likely to have been influenced by the truncated hinge of the bovine IgG2 molecule. Analysis of genetic divergence of the genes encoding bovine and human Fc gamma R and Fc alpha R indicated that the novel bovine gene and the human Fc alpha R gene probably evolved from a common ancestor, which is not shared by other Fc gamma R.

The utility of duplex ultrasound scanning of the renal arteries for diagnosing significant renal artery stenosis

OBJECTIVE

To determine the utility of duplex ultrasound scanning of the renal arteries in identifying patients with renal artery stenosis of 60% or more and in excluding patients with either normal renal arteries or renal artery stenosis of less than 60%.

DESIGN

A prospective, blinded study.

SETTING

Large tertiary referral center.

PATIENTS

102 consecutive patients (44 men and 58 women with a mean age [+@- SD] of 63.3 +/- 13.4 years) who had both duplex ultrasound scanning of the renal arteries and renal arteriography. All patients who were studied had hypertension that was difficult to control, unexplained azotemia, or associated peripheral vascular disease (alone or in combination), giving them a high pretest likelihood of renovascular disease.

MAIN OUTCOME MEASUREMENTS

Peak systolic and end diastolic velocities, renal-aortic ratios, resistive index, and kidney sizes.

RESULTS

Sixty-two of 63 arteries with stenosis of less than 60% using arteriography were correctly identified by duplex ultrasound scanning. Thirty-one of 32 arteries with 60% to 79% stenosis using arteriography were correctly identified as having 60% to 99% stenosis on duplex ultrasound, whereas 67 of 69 arteries with 80% to 99% stenosis on arteriography were correctly identified as having 60% to 99% stenosis on ultrasound. Twenty-two of 23 arteries with total occlusion on arteriography were correctly identified by duplex ultrasound. The overall sensitivity of duplex ultrasound compared with arteriography was 0.98, the specificity was 0.98, the positive predictive value was 0.99, and the negative predictive value was 0.97.

CONCLUSION

Duplex ultrasound scanning of the renal arteries is an ideal screening test because it is noninvasive and can predict the presence or absence of renal artery stenosis with a high degree of accuracy.

Identification and analysis of the expression of CD8 alpha beta and CD8 alpha alpha isoforms in chickens reveals a major TCR-gamma delta CD8 alpha beta subset of intestinal intraepithelial lymphocytes

Expression screening has been used to clone cDNAs encoding the alpha- and beta-chains of chicken CD8. Amino acid sequence similarities with the mammalian sequences were about 30%. Many amino acid residues of structural or functional importance were more highly conserved, as were the overall structures of both chains. Like human CD8 alpha, the chicken alpha-chain lacked sites for N-linked glycosylation, but the beta-chain contained three such sites. In COS cells transfected with CD8 beta cDNA, surface expression of the beta-chain was dependent on co-transfection of the alpha-chain cDNA, indicating that, as in mammals, chicken CD8 can be expressed as a CD8 alpha alpha homodimer or as a CD8 alpha beta heterodimer. Immunofluorescence analysis with mAbs that were shown to identify the CD8 alpha- and CD8 beta-chains revealed that the vast majority of the CD8+ cells in the thymus, spleen, and blood of adult chickens express both CD8 alpha- and CD8 beta-chains. However, a relatively large proportion of the CD8+ TCR-gamma delta cells in the spleens of embryos and young chicks express only the alpha-chain of CD8. Among intestinal epithelial lymphocytes the major CD8+ T cell populations present in mice are conserved, but there is a population of TCR-gamma delta CD8 alpha beta cells that is not found in rodents. This observation is important in interpretation of experiments examining the pathways of development of intestinal intraepithelial lymphocytes in chickens.

Identification and analysis of the expression of CD8 alpha beta and CD8 alpha alpha isoforms in chickens reveals a major TCR-gamma delta CD8 alpha beta subset of intestinal intraepithelial lymphocytes

Expression screening has been used to clone cDNAs encoding the alpha- and beta-chains of chicken CD8. Amino acid sequence similarities with the mammalian sequences were about 30%. Many amino acid residues of structural or functional importance were more highly conserved, as were the overall structures of both chains. Like human CD8 alpha, the chicken alpha-chain lacked sites for N-linked glycosylation, but the beta-chain contained three such sites. In COS cells transfected with CD8 beta cDNA, surface expression of the beta-chain was dependent on co-transfection of the alpha-chain cDNA, indicating that, as in mammals, chicken CD8 can be expressed as a CD8 alpha alpha homodimer or as a CD8 alpha beta heterodimer. Immunofluorescence analysis with mAbs that were shown to identify the CD8 alpha- and CD8 beta-chains revealed that the vast majority of the CD8+ cells in the thymus, spleen, and blood of adult chickens express both CD8 alpha- and CD8 beta-chains. However, a relatively large proportion of the CD8+ TCR-gamma delta cells in the spleens of embryos and young chicks express only the alpha-chain of CD8. Among intestinal epithelial lymphocytes the major CD8+ T cell populations present in mice are conserved, but there is a population of TCR-gamma delta CD8 alpha beta cells that is not found in rodents. This observation is important in interpretation of experiments examining the pathways of development of intestinal intraepithelial lymphocytes in chickens.

Health-related quality of life: measurement and clinical application. A workshop report

The process of measuring health-related quality of life (HQL) in oncology is reviewed and the role of these results in clinical practice and clinical trials is discussed. It is determined that comparisons of HQL measurement instruments are needed to clarify which questionnaires are preferable in particular populations or situations. "Calibration" data are also needed, to help explain the meaning of HQL scores and to link them to external reality. In phase III clinical trials, HQL assessment is most important in trials involving disease sites and stages with a poor prognosis and when comparing treatments not expected to affect survival.

Efficacy of Fenamiphos Formulations Applied through Irrigation for Control of Meloidogyne incognita on Squash

Management ofMeloidogyne incognita by chemigation with fenamiphos was studied in an infested field planted to M. incognita-suscepfible yellow summer squash cv. Dixie Hybrid. Fenamiphos (VL 73.1% a.i. manufacturing concentrate in propylene glycol) was mixed with Unitol DSR-90 or used as fenamiphos 3 SC (spray concentrate). Both formulations, applied with 63.5 kl irrigation water per hectare, decreased numbers of M. incognita second-stage juveniles in the soil and root-gall indices, and increased yield of squash compared with the untreated control. There was no benefit achieved by mixing the fenamiphos concentrate with Unitol DSR-90 over the use of fenamiphos 3 SC formulation. Fenamiphos application rates between 3.36 and 6.72 kg a.i./ha could provide control of M. incognita comparable to that obtained with 6.72 kg a.i./ha. Reduced rates of fenamiphos applied with irrigation water used to control plant-parasitic nematodes could reduce the potential for groundwater pollution as well as cost to the grower.

Ultrasound demonstration of small breast cancers detected by mammographic screening

The visibility on ultrasound (US) of 79 screen-detected small breast cancers was studied retrospectively. Overall visibility on US was 61% (48/79). Cancers presenting as microcalcification alone on mammography were rarely demonstrated (1 of 26 tumours). However, the US visibility of cancers with other mammographic appearances was 88.7% (47/53). The majority of cancers were impalpable but were demonstrated using free-hand ultrasound. All cancers visible on US appeared as hypoechoic masses with three quarters of these showing distal attenuation. US is useful in assessing and localizing small cancers detected by mammographic screening.

Linkage mapping and partial sequencing of 10 cDNA loci in the chicken

Ten cDNA clones derived from chicken spleen cell mRNA have been partially sequenced and the genes which encode the mRNAs have been located within the linkage map of the chicken genome. The sequences of five of these clones show strong homology to known mammalian genes, the remainder show little homology to sequence present in the current databases. Interestingly, one of these clones appears to be the chicken homologue of the mammalian peptide transporter gene TAP2 and is located within the major histocompatibility complex. Two other clones are homologous to genes involved in protein synthesis and these are tightly linked in chickens, as in mice. These results suggest that partial sequencing and mapping of clones from selective cDNA libraries may be an efficient way of adding candidate genes to the chicken linkage map and that on a local scale there may be some conservation of grouping of genes between chickens and mammalian species.

Research on health-related quality of life: dissemination into practical applications

Strategies and processes for the effective dissemination and diffusion of research findings on health-related quality of life (HQL) into practical applications were explored at a workshop held in Montreal in April, 1994. A conceptual model for dissemination and diffusion of evidence about HQL was used to identify five different target groups: HQL assessors, policy makers, planners of clinical trials, developers of clinical practice guidelines, and those at the level of patient-practitioner clinical decision making. A framework designed to facilitate the translation of fundamental research knowledge into effective action was then used as a starting point for discussions about priorities for research on HQL. The most important problem identified at the workshop was how best to strike an appropriate balance between priorities deemed to be important to those directly involved in HQL research, and priorities deemed to be important to potential users of the results of HQL research?

Monomeric homologue of mammalian CD28 is expressed on chicken T cells

A mAb recognizing a 40- to 44-kDa monomeric molecule on the surface of chicken T cells was used to screen a cDNA expression library made from Con A-stimulated chicken spleen cells. The sequence of the cDNA obtained encoded a molecule having 50% amino acid sequence identity with mammalian CD28, but the cysteine residue involved in the inter-chain bridge of the mammalian CD28 homodimer was not conserved in the chicken sequence. The molecule produced in transfected COS-7 cells was also recognized by another mAb that had previously been thought to recognize an avian homologue of CD2. The sequence data establish that this molecule is a homologue of mammalian CD28 in the strict evolutionary sense.

Monomeric homologue of mammalian CD28 is expressed on chicken T cells

A mAb recognizing a 40- to 44-kDa monomeric molecule on the surface of chicken T cells was used to screen a cDNA expression library made from Con A-stimulated chicken spleen cells. The sequence of the cDNA obtained encoded a molecule having 50% amino acid sequence identity with mammalian CD28, but the cysteine residue involved in the inter-chain bridge of the mammalian CD28 homodimer was not conserved in the chicken sequence. The molecule produced in transfected COS-7 cells was also recognized by another mAb that had previously been thought to recognize an avian homologue of CD2. The sequence data establish that this molecule is a homologue of mammalian CD28 in the strict evolutionary sense.

Ultrasound-guided compression repair of postcatheterization pseudoaneurysms: results of treatment in one hundred cases

PURPOSE

The purpose of this report is to describe the indications, technique, and results for ultrasound-guided compression repair (UGCR) of postcatheterization pseudoaneurysms at a large medical center in which catheter-based diagnostic and interventional procedures are frequently used.

METHODS

We reviewed the initial series of 100 consecutive patients who underwent UGCR in our noninvasive vascular laboratory from May 1991 through August 1992. Nearly all (n = 95) of these pseudoaneurysms involved the common femoral artery or its major branches, and each was manually compressed with a 5 MHz linear transducer for 10-minute intervals until the pseudoaneurysm was completely occluded or the procedure was considered to be a failure.

RESULTS

UCGR was immediately successful in 94 patients, including 30 (86%) of 35 patients who were receiving anticoagulants and 64 (98%) of the 65 who were not (p = 0.019). The average compression time to achieve occlusion was 33 minutes (range 10 to 120 minutes), but was nearly twice as long (51 minutes) for pseudoaneurysms that had been present for more than 14 days. There were no related complications, but recurrent pseudoaneurysms occurred in six (20%) of 30 patients who continued to receive formal anticoagulation, compared with only four (6%) of 64 who did not (p = 0.074). Eight of the 10 recurrences were discovered within 24 hours after primary UGCR, but two others presented at 16 and 35 days, respectively. Eight recurrent lesions were corrected by repeat UGCR, whereas the remaining two required surgical repair.

CONCLUSIONS

UGCR provides a reliable alternative to surgical treatment for postcatheterization pseudoaneurysms. Adequate follow-up is important, however, especially in patients for whom continued anticoagulation is necessary.

Electrophoretic karyotyping is a sensitive epidemiological tool for studying Trypanosoma evansi infections

Thirty-six isolates of trypanozoon trypanosomes collected from camels in Northern Kenya during the dry season sporadic infections of 1986 and during the wet season epidemic infections of 1987 were identified as Trypanosoma evansi by the homogeneity of their kinetoplast DNA minicircles. Although the minicircles of all the isolates were indistinguishable, polymorphism in chromosome-sized DNA molecules detected by electrophoresis was extensive. The isolates could be grouped into eight distinct electrophoretic karyotypes which could be distinguished from three additional karyotypes identified among earlier T. evansi isolates. In one camel herd with a long history of trypanocide application, which was continued during the present study, all isolates bar one belonged to one karyotype group. From a second herd, in which trypanosomosis management was by individual treatment of proven parasitaemic cases, isolates with diverse karyotypes were obtained. Some of the karyotypes identified during the dry season sporadic infections were re-isolated in the subsequent wet season epidemic. These observations indicate that distinguishing T. evansi isolates by molecular electrophoretic karyotypes is more discriminating than kDNA analysis. Observations of karyotype patterns recurring in isolates from herds kept under chemoprophylaxis could help in the identification of drug-resistant parasites.

Assessment of the role of ultrasound in the differentiation of radial scars and stellate carcinomas of the breast

Radial scars are benign lesions of the breast which cannot be reliably distinguished from carcinoma by their mammographic appearances alone [1,2]. The present wisdom is that all such lesions should be biopsied [2]. We report a retrospective study carried out to assess whether there are any ultrasound imaging features that may be useful in differentiating radial scars from carcinoma and so reduce the need for excision biopsy. Over a period of 44 months between 1988 and 1992, 530 patients underwent surgery for abnormalities detected by routine mammographic screening. Of the 191 benign lesions excised, 24 were radial scars. Ultrasound images of 21 radial scars were mixed with an equal number of images of histologically proven carcinomas that had similar mammographic appearances. These images were reviewed 'blind' by a single radiologist. We were unable to find any ultrasound appearances sufficiently specific to radial scars to allow confident exclusion of malignancy. We therefore endorse the current practice of biopsying all mammographically detected stellate lesions.

The incidence of deep venous thrombosis in patients undergoing abdominal aortic aneurysm resection

PURPOSE

Fifty consecutive patients undergoing abdominal aortic aneurysm resection were studied prospectively for the presence of deep venous thrombosis (DVT) after surgery.

METHODS

Bilateral venography was performed 5 days after surgery in all patients. There were 42 men and 8 women, with a mean age of 70 years (range 60 to 83 years). No patients received DVT prophylaxis before surgery.

RESULTS

Nine (18%) of 50 patients had a venogram positive for acute DVT. Nine (21%) of 42 men and none of eight women had DVT. Six patients had DVT in the left leg and three patients in the right leg. No patients had symptoms to suggest DVT. Seven (78%) of the nine patients with DVT had thrombi in the calf veins and two patients (22%) had thrombi in the more proximal venous segments, representing 14% and 4% of the entire series, respectively. No clinically evident pulmonary emboli were observed.

CONCLUSIONS

Eighteen percent of 50 consecutive patients undergoing abdominal aortic aneurysm resection had DVT. Because of this high incidence, a study should be undertaken to determine whether DVT prophylaxis can lower the incidence of DVT after abdominal aortic aneurysm resection.

Genome analysis of Theileria parva

Recent technological developments in the field of genome analyses have advanced our knowledge of the structures of prokaryotic and eukoryotic genomes. Examples of these range from small bacterial genomes, such as Escherichia coli, to the more complex genomes of Caenorhabditis elegans, Drosophila, humans and mouse. Here, Subhash Morzona and John Young review developments in mapping the genome of on economically important protozoan parasite o f cattle, Theileria parva. This map provides a framework for more detailed analysis of the genome structure o f this organism. The methodologies developed in constructing the map also have application to the mapping of other protozoan genomes.

Recommendations for training in vascular medicine. American College of Cardiology Peripheral Vascular Disease Committee

Each trainee in vascular medicine must be eligible for the board certification examination of the American Board of Internal Medicine or its equivalent. Training faculty, preferably at least two members, should meet the qualifications and training requirements described in this report. They must be dedicated, effective teachers and should spend most of their time in research, education and patient care related to peripheral vascular diseases. A curriculum of training should be established. Faculty experts in related specialties and in the related basic sciences should be available for teaching. The institution should have a fully equipped noninvasive vascular laboratory and areas where catheter revascularization techniques and vascular surgery are performed. The period of training should not be less than 1 year, preferably continuous.

Screening for breast cancer detects tumours at an earlier biological stage

Between August 1988 and July 1990, 17,678 women in the Gateshead, Sunderland, South Tyneside and Durham districts attended the national breast screening programme. A total of 131 cancers were detected. The morphology of cancers detected by screening was compared with that of tumours in 71 patients presenting clinically in the same period. Screen-detected cancers included a higher proportion of tumours of more favourable histological grade and type, were smaller in size and had less axillary lymph node involvement than those detected clinically. Survival was predicted from the Nottingham Prognostic Index. Patients with screen-detected cancer had an expected survival advantage (95 per cent confidence interval) of 26.5 (12.3-40.6) per cent at 5 years, 26.5 (11.8-41.2) per cent at 10 years and 29.1 (14.5-43.7) per cent at 15 years. This survival advantage in screened patients expected at 5, 10 and 15 years is consistent with the 30 per cent reduction in mortality rate demonstrated in the Health Insurance Plan study and the Swedish two counties trial.