The adenylate cyclase (BAC) in Botrytis cinerea is required for full pathogenicity

SUMMARY The grey mould Botrytis cinerea is an economically important plant pathogen. Previously we found that null mutants of bcg1 encoding one of the two Galpha subunits of heterotrimeric GTP-binding proteins differed in colony morphology and showed reduced pathogenicity. To further understand the mechanisms involved in infection, we cloned the bac gene encoding adenylate cyclase, the enzyme that catalyses production of cAMP from ATP. The deduced protein sequence consists of 2300 amino acids, the ORF is interrupted by three conserved introns, and there is a high degree of similarity with the catalytic domains of other fungal adenylate cyclases. Gene replacement resulted in reduced vegetative growth and a morphology similar to that of bcg1 mutants. The wild-type (WT) colony morphology was partially restored by feeding exogenous cAMP. These bac mutants still had a low but constant level of cAMP, despite deletion of the complete catalytic domain of the enzyme. Conidia from bac mutants germinated, penetrated the leaves of Phaseolus vulgaris and caused spreading soft rot lesions (in contrast to bcg1 mutants), although these were slower to develop than in WT controls. Compared to the latter, the most striking difference was that no sporulation occurred on leaves inoculated with bac mutant conidia. These results confirm that the cAMP signalling pathway plays an important role in vegetative growth and pathogenicity in B. cinerea. On the other hand, a much stronger effect of bcg1 mutation on pathogenicity in comparison to the effects of bac mutations suggests that BCG1 controls at least one more signalling component other than adenylate cyclase, and that the cAMP signalling pathway is not the only one responsible for pathogenicity.

Functional analysis of an extracellular catalase of Botrytis cinerea

Summary There is evidence that the necrotrophic fungal pathogen Botrytis cinerea is exposed to oxidative processes within plant tissues. The pathogen itself also generates active oxygen species and H(2)O(2) as pathogenicity factors. Our aim was to study how the pathogen may defend itself against cellular damage caused by the accumulation of H(2)O(2) and the role of an extracellular catalase in its detoxification during the infection of tomato and bean plants by B. cinerea. Chloronaphthol staining followed by light microscopy showed that H(2)O(2) accumulates in the infection zone in tomato and bean leaves. An extracellular catalase gene (denominated Bccat2) was cloned from B. cinerea. Exposure of mycelium to H(2)O(2) in liquid culture resulted in increased Bccat2 mRNA levels in a concentration-dependent manner. Bccat2 mRNA was detected at early stages of tomato leaf infection, suggesting that B. cinerea experiences oxidative stress. Bccat2-deficient mutants were generated by transformation-mediated gene disruption. Mutants were more sensitive then the wild-type strain to H(2)O(2)in vitro, but they partly compensated for the absence of BcCAT2 by activating other protective mechanisms in the presence of H(2)O(2). Bccat2-deficient mutants did not display a consistent reduction of virulence on bean and tomato leaves. Cerium chloride staining of infected leaf tissue for ultrastructural studies showed that Bccat2-deficient mutants were exposed to H(2)O(2) comparably to the wild-type. The results suggest that B. cinerea is a robust pathogen adapted to growing in hostile oxidizing environments in host tissues.

Mutagenesis of key amino acids alters activity of a Saccharomyces cerevisiae endo-polygalacturonase expressed in Pichia pastoris

A polygalacturonase (PG)-encoding gene from Saccharomyces cerevisiae (PGU1) was successfully expressed in the methylotrophic yeast Pichia pastoris. PG secretion was efficiently directed by the S. cerevisiae alpha-factor signal sequence, while the native (PGU1) leader peptide was unable to direct protein export in P. pastoris. The level of PGU1 activity achieved in P. pastoris was significantly enhanced when compared to activity using the same gene in S. cerevisiae. Expression of PG proteins, engineered by site-directed mutagenesis, in P. pastoris showed that aspartic acid residues at positions 179, 200, and 201, and histidine 222 were essential for enzyme activity. Mutation of the two potential glycosylation sites in PGU1 showed that the two residues individually (N318D, N330D) did not affect secreted enzyme activity, but the double mutant caused a 50% reduction in enzyme activity when compared to the wild-type PGU1 transformant.

Infection of leaves of Arabidopsis thaliana by Botrytis cinerea: changes in ascorbic acid, free radicals and lipid peroxidation products

Infection of leaves of Arabidopsis thaliana with conidial suspensions of the necrotrophic pathogen Botrytis cinerea resulted in a large decrease in the level of ascorbic acid and increases in intensity of a single-peak free radical and Fe(III) (g=4.27) signals in electron paramagnetic resonance (EPR) spectra. These changes were not confined to the spreading lesions or associated areas of chlorosis, but extended to other apparently healthy tissues in the infected leaves. They are, therefore, consistent with the existence of high levels of oxidative stress being generated as a result of the infection process. The expected accompanying increases in levels of the aldehydic products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE), were not observed, and in the case of MDA the levels in tissue from infected plants were appreciably lower than in the healthy controls. These last findings are surprising and demonstrate a difference in the response of A. thaliana to infection with B. cinerea compared with tissues from other plant families studied previously.

Botrydial is produced in plant tissues infected by Botrytis cinerea

The fungal metabolite botrydial was detected for the first time in ripe fruits of sweet pepper (Capsicum annuum) wound-inoculated with conidial suspensions of Botrytis cinerea and also in leaves of Phaseolus vulgaris and Arabidopsis thaliana inoculated without wounding. This phytotoxin was produced in soft rot regions of the infection. In C. annuum, the most aggressive isolate produced the highest botrydial concentrations in planta. The levels of botrydial produced by this isolate did not correlate with the reported relative susceptibilities of four P. vulgaris genotypes. The results suggest that botrydial is a pathogenicity factor for this fungus, but not a primary determinant of pathogenicity.

Immunohistochemical analysis of NY-ESO-1 antigen expression in normal and malignant human tissues

NY-ESO-1, a member of the CT (cancer/testis) family of antigens, is expressed in normal testis and in a range of human tumor types. Knowledge of NY-ESO-1 expression has depended on RT-PCR detection of mRNA and there is a need for detecting NY-ESO-1 at the protein level. In the present study, a method for the immunochemical detection of NY-ESO-1 in paraffin-embedded tissues has been developed and used to define the expression pattern of NY-ESO-1 in normal tissues and in a panel of human tumors. No normal tissue other than testis showed NY-ESO-1 reactivity, and expression in testis was restricted to germ cells particularly spermatogonia. In human tumors, the frequency of NY-ESO-1 antigen expression corresponds with past analysis of NY-ESO-1 mRNA expression e.g., 20-30% of lung cancers, bladder cancers and melanoma, and no expression in colon and renal cancer. Co-typing of NY-ESO-1 antigen and mRNA expression in a large panel of lung cancers showed a good correlation. There is great variability in NY-ESO-1 expression in individual tumors, ranging from an infrequent homogeneous pattern of staining to highly heterogeneous antigen expression.

Humoral immunity to human breast cancer: antigen definition and quantitative analysis of mRNA expression

The ability of the immune system to recognize structurally altered, amplified or aberrantly expressed proteins can be used to identify molecules of etiologic relevance to cancer and to define targets for cancer immunotherapy. In the current study, ninety-four distinct antigens reactive with serum IgG from breast cancer patients were identified by immunoscreening breast cancer-derived cDNA expression libraries (SEREX). A serological profile was generated for each antigen on the basis of reactivity with allogeneic sera from normal individuals and cancer patients, and mRNA expression profiles for coding sequences were assembled based upon the tissue distribution of expressed sequence tags, Northern blots and real-time RT-PCR. Forty antigens reacted exclusively with sera from cancer patients. These included well-characterized tumor antigens, e.g. MAGE-3, MAGE-6, NY-ESO-1, Her2neu and p53, as well as newly-defined breast cancer antigens, e.g. kinesin 2, TATA element modulatory factor 1, tumor protein D52 and MAGE D, and novel gene products, e.g. NY-BR-62, NY-BR-75, NY-BR-85, and NY-BR-96. With regard to expression profiles, two of the novel gene products, NY-BR-62 and NY-BR-85, were characterized by a high level of testicular mRNA expression, and were overexpressed in 60% and 90% of breast cancers, respectively. In addition, mRNA encoding tumor protein D52 was overexpressed in 60% of breast cancer specimens, while transcripts encoding SNT-1 signal adaptor protein were downregulated in 70% of these cases. This study adds to the growing list of breast cancer antigens defined by SEREX and to the ultimate objective of identifying the complete repertoire of immunogenic gene products in human cancer (the cancer immunome).

Immunohistochemical and reverse transcription-polymerase chain reaction expression analysis of tyrosinase and microphthalmia-associated transcription factor in angiomyolipomas

Angiomyolipomas (AMLs) show a characteristic immunoreactivity with melanocyte differentiation markers such as monoclonal antibody (mAb) HMB45, which detects melanocyte differentiation antigen gp100 and mAb A103 reacting with Melan-A/MART-1. Monoclonal antibody T311 to tyrosinase (a key enzyme of melanogenesis) and mAb D5 to the microphthalmia (Mitf) antigen are two newly available markers of melanocytic differentiation. The authors tested 15 AMLs with T311 and D5 by immunohistochemistry and a subset of 3 cases by reverse transcription-polymerase chain reaction for their expression of tyrosinase and Mitf mRNA. T311 showed poor sensitivity in AMLs because only focal staining was seen in 1 out of 15 cases, although tyrosinase mRNA was found in all tested cases. Mitf mRNA was present in 3 of 3 tested cases, and D5 was positive in 15 of 15 AMLs. However, D5 immunostaining often was focal and not as homogeneous as A103, which was analyzed in a previous study. D5 staining also could be seen in other cell types such as normal renal tubular cells, macrophages, and renal cell carcinoma. The current results show that in contrast with HMB45 and A103, T311 has little or no value in the diagnosis of AMLs. D5 may be useful in a panel of antibodies in the diagnosis of AMLs.

Coronary angiography observations: evidence-based or ritualistic practice?

OBJECTIVE

The purposes of this study were to describe the incidence and occurrence of femoral artery bleeding during the first 6 hours after coronary angiography and to determine whether there is a relationship between current postangiogram observation protocols and the detection of complications.

DESIGN

This was a prospective descriptive study.

SETTING

The study was conducted in 3 university hospitals in Melbourne, Australia.

PATIENTS

Subjects included 55 patients representing the complication rate of 1075 patients, mean age 61 years (SD, 12), 69% male.

RESULTS

About 5.1% of patients had 1 or more incidents of bleeding requiring manual compression. In 4.2% of patients, bleeding occurred within 6 hours of angiography. Bleeding occurred a median of 2.02 hours (Q1 = 45 minutes, Q3 = 4.31 hours) after angiography. Patients without pressure bandaging bled a median of 1.32 hours (Q1 = 36.50 minutes, Q3 = 2.59 hours) after angiography. Patients with pressure bandaging bled a median of 4.75 hours (Q1 = 2.25 hours, Q3 = 7.28 hours) after angiography. In 40.6% of cases, bleeding was detected through the patient's call for assistance, and in 59.4% of cases nurses noted bleeding while checking the puncture site. Postcatheter observations were recorded 23.70 (SD, 14.60) minutes before the bleeding incident. There were no significant changes in vital signs, systolic blood pressure (P >.05), diastolic blood pressure (P >.05), or pulse (P >.05) before or during a bleeding episode. All were within normal parameters. No neurovascular assessment anomalies were detected.

CONCLUSION

The use of pressure bandaging has a significant effect on the incidence and pattern of bleeding. Routine vital sign measurement has no relevance in detecting local complications after angiography. The most significant complication is bleeding that requires manual compression. Detection is through frequent puncture site observation and patient recognition and communication.

Markers for oxidative stress associated with soft rots in French beans (Phaseolus vulgaris) infected by Botrytis cinerea

The role of active oxygen species has been studied in spreading soft-rot lesions caused by the necrotrophic fungal pathogen Botrytis cinerea Pers.:Fr. in leaves of four genotypes of French bean (Phaseolus vulgaris L.). Large increases were observed for the aldehydic end-products of oxidative damage, malondialdehyde and 4-hydroxy-2-nonenal, as a result of infection in each of the genotypes studied. Similar increases were found in a stable free radical and g=4.27 Fe(III) signals, but not Mn(II) signals, in electron paramagnetic resonance spectra. These changes were accompanied by large decreases in ascorbic acid levels, with changes in the antioxidant glutathione being genotype dependent.

Botrytis cinerea induces the formation of free radicals in fruits of Capsicum annuum at positions remote from the site of infection

Free radical adducts of the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone have been observed by electron paramagnetic resonance spectroscopy in detached fruits of Capsicum annuum investigated 5 days after infection with Botrytis cinerea. The spectra of these adducts were at a maximum within the soft rot lesion, but they could also be detected at distances up to 50 mm from the edge of the lesion in samples following main vascular bundles. At distances greater than 40 mm, the spectrum of the ascorbate radical was also seen, and at greater distances from the lesion it was the only radical detected. With samples taken from parenchyma tissue adjacent to the vascular bundles there was little adduct formation and the ascorbate radical could be detected, albeit with reduced intensity compared to healthy tissue, at distances as small as 10 mm from the edge of the lesion. This observation of chemical changes at considerable distances from the infected tissue is in contrast to previous observations on the behaviour of other markers of oxidative stress (e.g., 4-hydroxynonenal, malondialdehyde, single-peak free radical, and Fe(III) (g = 4.27) electron paramagnetic resonance signals), where their levels decreased rapidly outside of the soft rot.

Providing visual information to validate 2-D to 3-D registration

This paper addresses a key issue of providing clinicians with visual information to validate the accuracy of 2-D/3-D registration for robot-assisted total hip replacement (THR) surgery. Although numerous registration approaches have been presented, the topic of registration validation has scarcely been addressed in the literature. In practice, clinicians rely on post-operative X-rays to assess the accuracy of implant placement. Motivated by this, we simulate a set of post-operative X-ray images by superimposing the implant positioned pre-operatively onto the intra-operatively collected and calibrated images of the femur, through a transformation computed by the 2-D/3-D registration. With these images, a judgment on the registration accuracy can be made. In addition, this paper introduces methods for superimposing pre-operative data on intra-operative X-ray images that were not corrected for distortion, by applying the same image distortion to the data. This paper also introduces a new framework for incorporating surface normals in the objective function for registration. A comparison between marker-based and image-based registration is conducted. The advantage of our approach is that the simulated post-operative X-ray images are very familiar to clinicians and, therefore, easy for them to interpret. As an added benefit, this technique provides new means for comparing the marker-based and image-based registration for robot-assisted THR surgery. This approach can be extended to other interventions where intra-operative images are used for registration.

Monoclonal antibody MA454 reveals a heterogeneous expression pattern of MAGE-1 antigen in formalin-fixed paraffin embedded lung tumours

Cancer/testis (CT) antigens such as those encoded by the MAGE-gene family are expressed in a wide variety of malignant neoplasms. In normal tissues, expression is generally restricted to testis. Current knowledge of the expression pattern of CT antigens is mainly based on mRNA analysis. Little is known about actual protein expression. We previously developed MA454, a monoclonal antibody (mAb) to MAGE-1 recombinant protein. By employing antigen retrieval techniques, we show that MA454 is reactive on formalin-fixed paraffin-embedded tissues. Immunohistochemical (IHC) analysis of a normal tissue panel revealed staining solely in germ cells of testes. A series of 59 lung tumours was co-typed for MAGE-1 expression by RT-PCR and by immunohistochemistry with MA454. MA454 was positive in 19/59 cases (32%). MAGE-1 mRNA was found in 17 of the 54 cases (32%) available for RT-PCR. Of the 19 MA454-reactive tumours, 15 showed a highly heterogeneous pattern of expression. The other 4 MA454 positive cases revealed immunoreactivity in >25% of tumour areas. Of the 53 cases typed for both, mRNA and protein expression, 48 co-typed whereas 5 cases were discrepant, a likely consequence of heterogeneous MAGE-1 expression. The predominantly focal expression of MAGE-1 suggests that this antigen might not be sufficient as a sole target for immunotherapeutic approaches.

Direct coupling of expanded bed adsorption with a downstream purification step

In the course of developing a cost-effective, scaleable process for the purification of a recombinant protein from Chinese hamster ovary (CHO) suspension cell culture, we investigated direct capture of this molecule using expanded bed adsorption (EBA). EBA combines clarification, purification, and concentration of the product into a single step. The unclarified bioreactor material was directly applied to a STREAMLINE 25 column containing an affinity STREAMLINE adsorbent. This work focused on simplifying the EBA operations and minimizing the overall processing time by running the EBA column unidirectionally, eluting in the expanded bed mode, and coupling the EBA column directly with ion exchange or hydrophobic interaction chromatography. Unidirectional EBA was clearly a simpler unit operation and did not require the use of specialized equipment. The increase in the elution pool volume was insignificant, especially when the EBA column was eluted directly onto the downstream column. Scale-down was simple and could be automated. Coupling of unidirectional EBA with a downstream purification step reduced processing time, equipment requirements and cost.

Expression of cancer-testis antigens in lung cancer: definition of bromodomain testis-specific gene (BRDT) as a new CT gene, CT9

In an effort to define new cancer-testis (CT) genes, we investigated whether BRDT, a testis-restricted member of the RING3 family of transcriptional regulators, is also expressed in cancer. Standard RT-PCR expression analysis detected BRDT transcripts in 12 of 47 cases of non-small cell lung cancer and single cases of both squamous cell carcinoma of the head and neck (1/12) and esophagus (1/12) but not in melanoma or in cancers of the colon, breast, kidney and bladder. Typing of 33 non-small cell lung cancers for coexpression of a panel of CT antigens revealed a high incidence (60%) of MAGE-3 mRNA expression, followed by MAGE-1 (36%), CT7/MAGE-C1 (30%), CT10 (30%), SSX4 (23%), BRDT (21%), NY-ESO-1 (21%) and HOM-MEL-40/SSX2 (15%). The coexpression pattern of these antigens provides a foundation for developing a polyvalent lung cancer vaccine.

Antigens recognized by autologous antibody in patients with renal-cell carcinoma

The screening of cDNA expression libraries derived from human tumors with autologous antibody (SEREX) is a powerful method for defining the structure of tumor antigens recognized by the humoral immune system. Sixty-five distinct antigens (NY-REN-1 to NY-REN-65) reactive with autologous IgG were identified by SEREX analysis of 4 renal cancer patients and were characterized in terms of cDNA sequence, mRNA expression pattern, and reactivity with allogeneic sera. REN-9, -10, -19, and -26 have a known association with human cancer. REN-9 (LUCA-15) and REN-10 (gene 21) map to the small cell lung cancer tumor suppressor gene locus on chromosome 3p21.3. REN-19 is equivalent to LKB1/STK11, a gene that is defective in Peutz-Jeghers syndrome and cancer. REN-26 is encoded by the bcr gene involved in the [t(9:22)] bcr/abl translocation. Genes encoding 3 of the antigens in the series showed differential mRNA expression; REN-3 displays a pattern of tissue-specific isoforms, and REN-21 and REN-43 are expressed at a high level in testis in comparison to 15 other normal tissues. The other 62 antigens were broadly expressed in normal tissues. With regard to immunogenicity, 20 of the 65 antigens reacted only with autologous sera. Thirty-three antigens reacted with sera from normal donors, indicating that their immunogenicity is not restricted to cancer. The remaining 12 antigens reacted with sera from 5-25% of the cancer patients but not with sera from normal donors. Seventy percent of the renal cancer patients had antibodies directed against one or more of these 12 antigens. Our results demonstrate the potential of the SEREX approach for the analysis of the humoral immune response against human cancer.

Lipid peroxidation and the oxidative burst associated with infection of capsicum annuum by botrytis cinerea

A combination of electron paramagnetic resonance (EPR) spectroscopy and analytical chemistry has been used to study the changes in free radical content, transition metal ion status and lipid peroxidation following inoculation of fruits of sweet pepper (Capsicum annuum) with Botrytis cinerea. EPR detected a high concentration of an unidentified free radical associated with the spreading lesion that extends into the surrounding, healthy tissues. In addition, the EPR-detectable iron(III) was highest at the centre of the lesion, again displaying a gradient out into the surrounding tissues. Analyses for aldehydic products of lipid peroxidation were performed to assess the accumulation and potential of these compounds to contribute to the cell death associated with necrotrophic pathogens. In contrast to the spectrum of aldehydes typically observed within peroxidized biological samples, no accumulation of malondialdehyde nor n-hexanal was observed. Instead, high levels of two hydroxyalkenals (4-hydroxy-2-hexenal and 4-hydroxy-2-nonenal) were detected at concentra- tions up to 4000 and 20 000 pmol g- 1, respectively, at the host-pathogen interface. These results are discussed in terms of the likely mechanisms of formation of these aldehydes.

The in vivo assessment of tibial motion in the transverse plane in anterior cruciate ligament-reconstructed knees

Twenty-one knees with acutely injured anterior cruciate ligaments were reconstructed with patellar tendon autografts. Eight of the knees had concomitant medial ligament injuries that were not addressed surgically. Follow-up evaluation (average, 25 months) included computed tomography measurements to analyze transverse-plane laxity in both translation and rotation. These measurements were performed with the patient's leg in a load cell device that stabilizes the distal femur and applies known anterior translational force to the proximal tibia at approximately 20 degrees of flexion. A torque apparatus was used to apply internal and external rotational torque to the leg. Images of the tibial plateau in neutral, internal, and external rotation were performed, with and without an anterior translational force. Both knees of each patient were tested and categorized as group I (anterior cruciate ligament-reconstructed) or group II (uninjured). Translation as measured by computed tomography averaged 1 mm side-to-side difference. Internal rotation averaged 8.7 degrees in group I knees and 10.8 degrees in group II knees. External rotation averaged 9.1 degrees in group I knees and 7.4 degrees in group II knees. The eight knees with concomitant medial ligament injuries were analyzed separately; external rotation without anterior load in group I was 9.5 degrees, compared with 5 degrees in group II. This difference was significant (P < 0.01).

Computer-integrated revision total hip replacement surgery: concept and preliminary results

This paper describes an ongoing project to develop a computer-integrated system to assist surgeons in revision total hip replacement (RTHR) surgery. In RTHR surgery, a failing orthopedic hip implant, typically cemented, is replaced with a new one by removing the old implant, removing the cement and fitting a new implant into an enlarged canal broached in the femur. RTHR surgery is a difficult procedure fraught with technical challenges and a high incidence of complications. The goals of the computer-based system are the significant reduction of cement removal labor and time, the elimination of cortical wall penetration and femur fracture, the improved positioning and fit of the new implant resulting from precise, high-quality canal milling and the reduction of bone sacrificed to fit the new implant. Our starting points are the ROBODOC system for primary hip replacement surgery and the manual RTHR surgical protocol. We first discuss the main difficulties of computer-integrated RTHR surgery and identify key issues and possible solutions. We then describe possible system architectures and protocols for preoperative planning and intraoperative execution. We present a summary of methods and preliminary results in CT image metal artifact removal, interactive cement cut-volume definition and cement machining, anatomy-based registration using fluoroscopic X-ray images and clinical trials using an extended RTHR version of ROBODOC. We conclude with a summary of lessons learned and a discussion of current and future work.

Electronic imaging and clinical implementation: work group approach at Mayo Clinic, Rochester

Electronic imaging clinical implementation strategies and principles need to be developed as we move toward replacement of film-based radiology practices. During an 8-month period (1998 to 1999), an Electronic Imaging Clinical Implementation Work Group (EICIWG) was formed from sections of our department: Informatics Lab, Finance Committee, Management Section, Regional Practice Group, as well as several organ and image modality sections of the Department of Diagnostic Radiology. This group was formed to study and implement policies and strategies regarding implementation of electronic imaging into our practice. The following clinical practice issues were identified as key focus areas: (1) optimal electronic worklist organization; (2) how and when to link images with reports; (3) how to redistribute technical and professional relative value units (RVU); (4) how to facilitate future practice changes within our department regarding physical location and work redistribution; and (5) how to integrate off-campus imaging into on-campus workflow. The EICIWG divided their efforts into two phases. Phase I consisted of Fact finding and review of current practice patterns and current economic models, as well as radiology consulting needs. Phase II involved the development of recommendations, policies, and strategies for reengineering the radiology department to maintain current practice goals and use electronic imaging to improve practice patterns. The EICIWG concluded that electronic images should only be released with a formal report, except in emergent situations. Electronic worklists should support and maintain the physical presence of radiologists in critical areas and direct imaging to targeted subspecialists when possible. Case tools should be developed and used in radiology and hospital information systems (RIS/HIS) to monitor a number of parameters, including professional and technical RVU data. As communication standards improve, proper staffing models must be developed to facilitate electronic on-campus and off-campus consultation.

Electronic imaging impact on image and report turnaround times

We prospectively compared image and report delivery times in our Urgent Care Center (UCC) during a film-based practice (1995) and after complete implementation of an electronic imaging practice in 1997. Before switching to a totally electronic and filmless practice, multiple time periods were consistently measured during a 1-week period in May 1995 and then again in a similar week in May 1997 after implementation of electronic imaging. All practice patterns were the same except for a film-based practice in 1995 versus a filmless practice in 1997. The following times were measured: (1) waiting room time, (2) technologist's time of examination, (3) time to quality control, (4) radiology interpretation times, (5) radiology image and report delivery time, (6) total radiology turn-around time, (7) time to room the patient back in the UCC, and (8) time until the ordering physician views the film. Waiting room time was longer in 1997 (average time, 26:47) versus 1995 (average time, 15:54). The technologist's examination completion time was approximately the same (1995 average time, 06:12; 1997 average time, 05:41). There was also a slight increase in the time of the technologist's electronic verification or quality control in 1997 (average time, 7:17) versus the film-based practice in 1995 (average time, 2:35). However, radiology interpretation times dramatically improved (average time, 49:38 in 1995 versus average time 13:50 in 1997). There was also a decrease in image delivery times to the clinicians in 1997 (median, 53 minutes) versus the film based practice of 1995 (1 hour and 40 minutes). Reports were available with the images immediately upon completion by the radiologist in 1997, compared with a median time of 27 minutes in 1995. Importantly, patients were roomed back into the UCC examination rooms faster after the radiologic procedure in 1997 (average time, 13:36) than they were in 1995 (29:38). Finally, the ordering physicians viewed the diagnostic images and reports in dramatically less time in 1997 (median, 26 minutes) versus 1995 (median, 1 hour and 5 minutes). In conclusion, a filmless electronic imaging practice within our UCC greatly improved radiology image and report delivery times, as well as improved clinical efficiency.

Radiologist-patient interactions: implications for picture archiving and communications systems and teleradiology

We analyzed radiologist-patient interactions and found that radiologic examinations can be classified into three categories: those involving direct interaction of the radiologist with each patient, those involving interaction of the radiologist with some of the patients, and those that do not involve interaction between the radiologist and the patient. We then analyzed the staff assignments of a large academic radiology practice and a moderate-sized radiology department. Both departments include a full range of inpatient and outpatient procedures. We concluded that about 50% of the radiologists in these practices could interpret examinations at a location independent of the site where the examination was performed. This type of analysis can be helpful in planning for the reengineering of radiology processes following implementation of picture archiving and communications systems (PACS) and teleradiology.

Expression of melanocyte-associated markers gp-100 and Melan-A/MART-1 in angiomyolipomas. An immunohistochemical and rt-PCR analysis

Angiomyolipomas are tumours of uncertain histogenesis, most often occurring in association with the kidney. A characteristic finding is their reactivity with HMB-45, a monoclonal antibody to the melanocyte-associated antigen gp-100. We tested 18 angiomyolipomas for their reactivity with A103, a monoclonal antibody to Melan-A (MART-1), another melanocyte-associated marker, and compared it with HMB-45. All cases were positive with both antibodies, yet most cases showed a more homogeneous staining pattern with A103. Normal kidney was immunohistochemically negative for both antibodies. We also performed RT-PCR assays for gp-100 and Melan-A in 4 of the 18 angiomyolipoma samples and in three normal kidney samples. All 4 angiomyolipoma specimens revealed mRNA for both melanocyte differentiation markers. gp-100 mRNA was found in the samples of normal kidney, but Melan-A mRNA was not. Our study shows that angiomyolipomas express the melanocyte-associated antigens Melan-A and gp-100 at the protein and at the mRNA level, suggesting a true expression of these antigens rather than cross-reacting epitopes. Based on the mRNA expression pattern, immunohistochemical analysis is the preferred method for the detection of gp-100, while Melan-A can be used at the protein and mRNA levels. Our study demonstrates that A103 is a useful marker for the diagnosis of angiomyolipomas.

Isoforms of the human PDZ-73 protein exhibit differential tissue expression

Patients with renal and colon cancer frequently develop IgG autoantibodies toward the NY-CO-38/PDZ-73 antigen, a protein of 652 amino acids (73 kDa) which contains three copies of the PDZ protein-protein interaction domain. The gene encoding PDZ-73 mapped to chromosome 11p15.4-p15.1. Additional tissue-specific isoforms were identified: PDZ-45, which lacks the third PDZ domain and the putative PEST protein degradation motif, is expressed in kidney, colon, small intestine, brain and testis; PDZ-54 and PDZ-59, which also lack the third PDZ domains, have unique carboxyl terminal amino acids and are expressed in brain, kidney, bladder, colon cancer and renal cancer; and a putative PDZ-37 isoform, containing only the third PDZ domain, that is expressed in the central nervous system. Immunohistochemical staining with anti-PDZ 73 monoclonal antibodies showed strong cytoplasmic reactivity in epithelial cells of the small intestine, colon and kidney tubules, with a prominent apical staining pattern in cells of the small intestine. The reactivity pattern of the antibodies with various tissues correlated with the mRNA expression pattern of the PDZ-45 isoform. The existence of multiple PDZ-73 isoforms with variations in tissue distribution, PDZ domains, protein degradation sequences and carboxyl terminal structure indicate that these isoforms have distinct tissue-specific functions.

The effect of pressure bandaging on complications and comfort in patients undergoing coronary angiography: a multicenter randomized trial

OBJECTIVES

To determine the effectiveness of pressure bandaging in reducing bleeding and bruising in patients undergoing coronary angiography and to investigate the contribution that pressure bandages make to patient discomfort after angiography.

DESIGN

A prospective multicenter, randomized study.

SETTING

Three university hospitals in Melbourne, Australia.

PATIENTS

One thousand seventy-five patients undergoing coronary angiography were randomized to receive a pressure bandage (N = 556) or no bandage (N = 519) after manual compression of the right femoral artery puncture site.

RESULTS

Patients without pressure bandages had a higher incidence of bleeding (P < 0.05) and bled earlier (mean 2.4 hours; SD 3.6 hours) after catheter removal (P < 0.001) than patients with bandages (mean 5.3 hours; SD 3.8 hours). The incidence of bleeding in patients without pressure bandages was 6.7%. The incidence and extent of bruising was the same for both groups. Patients with pressure bandages experienced a higher incidence of back (P < 0.05), groin (P < 0.001), and leg pain (P < 0.001), nausea (P < 0.05) and urinary difficulty (P < 0.01).

CONCLUSIONS

In view of the associated increase in patient discomfort and the delay in time of onset of bleeding, pressure bandages should not be used routinely in the management of patients after coronary angiography, especially in the context of early discharge from the hospital.

Picture archiving and communication system activities at the Mayo Clinic Rochester

This report summarizes Mayo Clinic Rochester's experience with a picture archiving and communication system (PACS) to date and discusses the principles that have guided implementation.

Anatomy-based registration of CT-scan and intraoperative X-ray images for guiding a surgical robot

We describe new methods for rigid registration of a preoperative computed tomography (CT)-scan image to a set of intraoperative X-ray fluoroscopic images, for guiding a surgical robot to its trajectory planned from CT. Our goal is to perform the registration, i.e., compute a rotation and translation of one data set with respect to the other to within a prescribed accuracy, based upon bony anatomy only, without external fiducial markers. With respect to previous approaches, the following aspects are new: 1) we correct the geometric distortion in fluoroscopic images and calibrate them directly with respect to the robot by affixing to it a new calibration device designed as a radiolucent rod with embedded metallic markers, and by moving the device along two planes, while radiographs are being acquired at regular intervals; 2) the registration uses an algorithm for computing the best transformation between a set of lines in three space, the (intraoperative) X-ray paths, and a set of points on the surface of the bone (imaged preoperatively), in a statistically robust fashion, using the Cayley parameterization of a rotation; and 3) to find corresponding sets of points to the X-ray paths on the surfaces, our new approach consists of extracting the surface apparent contours for a given viewpoint, as a set of closed three-dimensional nonplanar curves, before registering the apparent contours to X-ray paths. Aside from algorithms, there are a number of major technical difficulties associated with engineering a clinically viable system using anatomy and image-based registration. To detect and solve them, we have so far conducted two experiments with the surgical robot in an operating room (OR), using CT and fluoroscopic image data of a cadaver bone, and attempting to faithfully simulate clinical conditions. Such experiments indicate that intraoperative X-ray-based registration is a promising alternative to marker-based registration for clinical use with our proposed method.

Characterization of human colon cancer antigens recognized by autologous antibodies

The screening of cDNA expression libraries derived from human tumors with autologous antibody (SEREX) has proven to be a powerful method for defining the structure of tumor antigens recognized by the humoral immune system. In the present study, 48 distinct antigens (NY-CO-1-NY-CO-48) reactive with autologous IgG were identified by SEREX analysis in 4 patients with colon cancer. Sequencing analysis showed that 17 of the cDNA clones were previously uncharacterized molecules and 31 represented known gene products. The individual cDNA clones were analyzed in the following manner: a search for mutations or other structural changes; an analysis of mRNA expression in a panel of normal tissues; and a frequency analysis of the antibody response to the expressed product in the sera of colon cancer patients and normal individuals. The initial analysis showed NY-CO-13 to be a mutated version of the p53 tumor suppressor gene. Three of the 48 antigens showed a differential pattern of mRNA expression, with NY-CO-27 (galectin-4) expressed primarily in gastrointestinal tract, and NY-CO-37 and -38 showing a pattern of tissue-specific isoforms. With regard to immunogenicity, 20 of the 48 antigens were detected by allogeneic sera; 14 of these were reactive with sera from both normal donors and cancer patients, and 6 other clones (NY-CO-8, -9, -13, -16, -20 and -38) reacted exclusively with sera from colon cancer patients (ranging from 14% to 27%). Our results on colon cancer illustrate both the complexity and the potential of the SEREX approach for analysis of the humoral immune response against human cancer.

Characterization of human colon cancer antigens recognized by autologous antibodies

The screening of cDNA expression libraries derived from human tumors with autologous antibody (SEREX) has proven to be a powerful method for defining the structure of tumor antigens recognized by the humoral immune system. In the present study, 48 distinct antigens (NY-CO-1-NY-CO-48) reactive with autologous IgG were identified by SEREX analysis in 4 patients with colon cancer. Sequencing analysis showed that 17 of the cDNA clones were previously uncharacterized molecules and 31 represented known gene products. The individual cDNA clones were analyzed in the following manner: a search for mutations or other structural changes; an analysis of mRNA expression in a panel of normal tissues; and a frequency analysis of the antibody response to the expressed product in the sera of colon cancer patients and normal individuals. The initial analysis showed NY-CO-13 to be a mutated version of the p53 tumor suppressor gene. Three of the 48 antigens showed a differential pattern of mRNA expression, with NY-CO-27 (galectin-4) expressed primarily in gastrointestinal tract, and NY-CO-37 and -38 showing a pattern of tissue-specific isoforms. With regard to immunogenicity, 20 of the 48 antigens were detected by allogeneic sera; 14 of these were reactive with sera from both normal donors and cancer patients, and 6 other clones (NY-CO-8, -9, -13, -16, -20 and -38) reacted exclusively with sera from colon cancer patients (ranging from 14% to 27%). Our results on colon cancer illustrate both the complexity and the potential of the SEREX approach for analysis of the humoral immune response against human cancer.

Responses of cells and protoplasts of Coffea arabica genotypes to partially purified culture filtrates produced by Colletotrichum kahawae

Hypocotyl-derived calli of genotypes and segregating populations of Coffea arabica, differing in susceptibility to Colletotrichum kahawae, were used to produce cell suspensions and protoplasts which were exposed to partially purified culture filtrates (PPCFs) prepared from the pathogen. The growth and viability of PPCF-treated cells and protoplasts were measured using packed cell volume, fluorescein diacetate staining and a colorimetric assay involving the tetrazolium salt MTT. Differential responses of cells and protoplasts were influenced by genotype, time of exposure and PPCF concentration. Protoplasts of resistant genotypes responded differentially from more susceptible genotypes as early as 4 h after challenge with the phytotoxin, suggesting that they were more sensitive than cell suspensions to the treatments. Protoplasts exposed to PPCFs from C. kahawae may therefore be used to screen and select genotypes resistant to, or tolerant of, coffee berry disease.

Characterization of tumor necrosis factor-deficient mice

Although tumor necrosis factor (TNF) initially came to prominence because of its anti-tumor activity, most attention is now focused on its proinflammatory actions. TNF appears to play a critical role in both early and late events involved in inflammation, from localizing the noxious agent and amplifying the cellular and mediator responses at the local site and systemically, to editing (e.g., apoptosis) injured cells or effete immune cells and repairing inflammatory damage. We have generated mice deficient in TNF (TNF-/- mice) and have begun to examine the multiple functions attributed to TNF. TNF-/- mice develop normally and have no gross structural or morphological abnormalities. As predicted, they are highly susceptible to challenge with an infectious agent (Candida albicans), are resistant to the lethality of minute doses of lipopolysaccharide (LPS) following D-galactosamine treatment, have a deficiency in granuloma development, and do not form germinal centers after immunization. Phagocytic activity of macrophages appears relatively normal, as do T cell functions, as measured by proliferation, cytokine release, and cytotoxicity. B cell response to thymus-independent antigens is normal, but the Ig response to thymus-dependent antigen is reduced. Surprisingly, cytokine production induced by LPS appears essentially intact, with the exception of reduced colony-stimulating factor activity. Other unexpected findings coming from our initial analysis are as follows. (i) TNF has low toxicity in TNF-/- mice. (ii) TNF-/- mice show an anomalous late response to heat-killed Corynebacterium parvum. In contrast to the prompt response (granuloma formation, hepatosplenomegaly) and subsequent resolution phase in C. parvum-injected TNF+/+ mice, similarly treated TNF-/- mice show little or no initial response, but then develop a vigorous, disorganized inflammatory response leading to death. These results suggest that TNF has an essential homeostatic role in limiting the extent and duration of an inflammatory process-i.e., an anti-inflammatory function. (iii) In contrast to the expectation that TNF+/+ mice and TNF+/- mice would have identical phenotypes, TNF+/- mice showed increased susceptibility to high-dose LPS lethality, increased susceptibility to Candida challenge, and delayed resolution of the C. parvum-induced inflammatory process, indicating a strong gene dose requirement for different actions of TNF.

A testicular antigen aberrantly expressed in human cancers detected by autologous antibody screening

Serological analysis of recombinant cDNA expression libraries (SEREX) using tumor mRNA and autologous patient serum provides a powerful approach to identify immunogenic tumor antigens. We have applied this methodology to a case of esophageal squamous cell carcinoma and identified several candidate tumor targets. One of these, NY-ESO-1, showed restricted mRNA expression in normal tissues, with high-level mRNA expression found only in testis and ovary tissues. Reverse transcription-PCR analysis showed NY-ESO-1 mRNA expression in a variable proportion of a wide array of human cancers, including melanoma, breast cancer, bladder cancer, prostate cancer, and hepatocellular carcinoma. NY-ESO-1 encodes a putative protein of Mr 17,995 having no homology with any known protein. The pattern of NY-ESO-1 expression indicates that it belongs to an expanding family of immunogenic testicular antigens that are aberrantly expressed in human cancers in a lineage-nonspecific fashion. These antigens, initially detected by either cytotoxic T cells (MAGE, BAGE, GAGE-1) or antibodies [HOM-MEL-40(SSX2), NY-ESO-1], represent a pool of antigenic targets for cancer vaccination.

Specificity of volumetric magnetic resonance imaging in detecting hippocampal sclerosis

BACKGROUND

Magnetic resonance imaging (MRI)-based volumetric measurements of the hippocampal formation are useful in detecting unilateral hippocampal sclerosis (HS) in patients with temporal lobe epilepsy. In this pathologic entity, volumetric MRI analysis shows the epileptogenic structure to be atrophic when compared with the normal, nonepileptogenic side. Some authors have suggested that the radiological features of atrophy of medial temporal lobe structures are common in patients with complex partial seizures, but also are seen frequently in other seizure types and can occur even in patients without epilepsy.

OBJECTIVE

To determine if seizures originating in extrahippocampal sites cause gliosis, cell loss, and atrophy of medial temporal lobe structures (i.e., HS).

METHODS

We studied 110 patients with chronic epilepsy using volumetric MRI measurements of the hippocampal formation. Seventeen patients had pathologically proven HS, 27 patients had seizures due to extratemporal structural lesions, 15 patients had seizures caused by extrahippocampal temporal lobe lesions, 29 patients had primary generalized epilepsy, and 22 patients had secondary generalized epilepsy.

RESULTS

All 17 patients with HS showed significantly reduced absolute hippocampal formation volumes of greater than 2 SDs below the mean of the control groups. The preoperative hippocampal formation volume measurements correlated well with the severity of HS on pathological examination. Hippocampal volumes were within the normal range in all patients with primary generalized epilepsy, secondary generalized epilepsy, extratemporal structural lesions, and extrahippocampal temporal lobe lesions.

CONCLUSIONS

Seizures originating at extrahippocampal sites do not cause gliosis, cell loss, or atrophy of medial temporal structures. Significant reduction in hippocampal volumes is a specific marker for HS.

Medial temporal lobe heterotopia as a cause of increased hippocampal and amygdaloid MRI volumes

Magnetic resonance imaging (MRI)-based volumetric measurements of the hippocampus and amygdala are useful in detecting hippocampal and amygdaloid sclerosis in patients with temporal lobe epilepsy. In these pathological entities, volumetric MRI analysis shows the epileptogenic structures to be atrophic when compared to the normal, nonepileptogenic side. Described are 2 patients with increased hippocampal and amygdaloid volumes on the side of seizure onset due to medial temporal lobe heteroto pias. Care must be taken in the interpretation of volumetric MRI data to make certain that asymmetries in hippocampal and amygdaloid measurements are due to atrophy and sclerosis of the abnormal side and not to increased tissue such as heterotopic gray matter.

Symptomatic spinal hemangiomas in association with cutaneous hemangiomas. A case report

STUDY DESIGN

This case report describes a patient with associated vertebral and peripheral vascular malformations presenting with a painful scoliosis.

OBJECTIVES

To treat the vertebral osseous lesion successfully with embolization.

SUMMARY OF BACKGROUND DATA

Although vertebral vascular malformations are well described, the association with peripheral lesions is uncommon. When associated peripheral vascular malformations occur, they are usually in tissues derived from the same embryonic segment, which was not the case in this instance.

METHODS

After investigation with angiography, this patient's vertebral osseous lesion was treated by embolization.

RESULTS

This patient's pain has been abolished since embolization. Her scoliosis has not progressed during follow-up.

CONCLUSIONS

This case illustrates the association between spinal and peripheral vascular malformations, and that this association is not always metameric. It highlights the fact that invasive procedures other than surgery are a valuable part of the therapeutic armamentarium.

High field NMR microscopic imaging of cultivated strawberry fruit

The experimental conditions required for discrimination of various types of tissue in fruits of cultivated strawberry (Fragaria x Ananassa) at high fields (ca. 7 T) have been investigated. In marked contrast to soft fruits of other species, from which informative images have been derived at high fields using a variety of pulse sequences and acquisition parameters, appreciable image intensities from parenchymal and vascular tissues in healthy strawberry fruits were obtained only with a spin-echo imaging sequence using large sweep widths (ca. 100,000 Hz), and consequently small values for TE ( < 5 ms), indicating predominantly short T2 values for these tissues. Damage caused by infection by the fungal pathogen Botrytis cinerea is readily seen as a result of a large increase in T2 in the infected tissue, whereas ripening processes appear to be characterized primarily by small variations in the T2-weighted contrast and in the relative magnitudes of T1 between vascular and parenchymal tissue. In addition, it was possible selectively to enhance the contributions to images from the achenes ("seeds") by using very short relaxation delays, thereby enhancing T1-dominated contrast mechanisms.