Telepresence interface with applications to microsurgery and surgical simulation

To address the needs for performing microsurgical procedures, the SRI telepresence surgery workstation has been combined with a pair of micromanipulator arms. The prototype microsurgery system has been tested with ex-vivo tasks similar to those required for surgical procedures, such as cutting, grasping, suturing, and knot tying. Initial animal testing has been done on a rat model in which end-to-end anastomosis of the femoral artery (approximately 1 millimeter in diameter) was completed with ten rats, and 100% patency was obtained. To address the needs of surgical training, SRI has begun to develop a system that uses a 6-DOF telepresence workstation. A computer-generated stereo image is reflected in a mirror and appears to be superimposed on the surgeon's hands, creating an immersive and realistic environment. Tools held in the surgeon's hands are connected to left- and right-hand manipulators that both continuously measure tool position/orientation and apply force/torque to the tools. Furthermore, the visual image and tool locations are registered, so that the user perceives that he or she is looking at and moving the simulated tools in the visual image.

Measurement of cytotoxic T lymphocyte precursor frequencies reveals cryptic HLA class I mismatches in the context of unrelated donor bone marrow transplantation

BACKGROUND

In this large, two-center study, 260 cytotoxic T lymphocyte precursor (CTLp) frequency assays, performed to assess patient-donor compatibility, were analyzed in relation to the degree of HLA matching.

METHODS

While the tissue-typing techniques used at the Royal Postgraduate Medical School (RPMS) and Anthony Nolan Bone Marrow Trust (ANBMT) differ, the results of the analyses on the two sites are analogous, with high CTLp frequencies (>1:100,000) in 42% and 41% of recipient-donor pairs, respectively.

RESULTS

Recipient-donor combinations with class I mismatches and class II identity were associated with high CTLp frequencies (collectively 83% vs. 17% low CTLp). This correlation was not as strong in pairs where class II mismatches were demonstrated (61% high vs. 39% low). Despite using different matching procedures, the RPMS and ANBMT both show that 32% of the "perfectly" matched pairs (i.e., where no mismatch was detected by any of the techniques used here) had high frequencies of recipient-specific CTLp.

CONCLUSIONS

The failure of conventional methods to identify such a level of histoincompatibilities indicates that the CTLp assay has an important role in the selection of unrelated donors for bone marrow transplantation.

Adult onset of acute myeloid leukaemia (M6) in patients with Shwachman-Diamond syndrome

Three male patients (two of whom were brothers) with Shwachman-Diamond (SDS) syndrome presented with acute myeloid leukaemia in adulthood. In all three cases there was trilineage myelodysplasia and the morphology was consistent with FAB subtype M6. SDS is an inherited bone marrow failure syndrome with a high propensity to leukaemic transformation. Since this may not occur until adulthood, SDS should be considered in the differential diagnosis of adults presenting with acute myeloid leukaemia, particularly where features of myelodysplasia are prominent.

New insights in biology and current therapeutic options for patients with chronic myelogenous leukemia

BACKGROUND AND OBJECTIVE

From the discovery of the Ph-chromosome, there has been an extraordinary progress in our understanding of chronic myeloid leukemia (CML). During the last three decades, new findings arising from dissection of the genetic abnormalities at a molecular level have received the most attention, but there have also been important new observations arising from studies of the biologic behaviour of normal and leukemic stem cells and, more recently, from clinical investigations. In this review we first report the most important observations relevant to understanding the oncogenic potential of the BCR-ABL chimeric gene, and the behaviour and the relationships of normal and leukemic stem cells. From a clinical point of view, allogeneic stem cell transplantation is the only procedure able to cure CML. The main issues are: who can receive this procedure, and when and how it can be given. The situation is more complex in unrelated transplants. In patients without HLA compatible donors, many large trials in different countries have demonstrated that interferon alpha therapy is indicated and effective in the majority of patients. On the other hand, autologous stem cell transplantation is still an experimental procedure. These aspects will be analyzed in detail and, at the end, a therapeutic algorithm of a possible approach to the patients with untreated CML is provided.

EVIDENCE AND INFORMATION SOURCES

The method used for preparing this review was an informal consensus development. All the authors of the present review have been working in the field of chronic myeloid leukemia, and have contributed original papers in peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline.

STATE OF ART AND PERSPECTIVES

The oncogenic potential of BCR-ABL has been demonstrated in a number of in vitro and in vivo model systems. Current research efforts are focused on defining the mechanism by which BCR-ABL transforms primary hematopoietic cells. The fact that BCR-ABL contains tyrosine residues, an SH2 domain, an SH3 domain, and proline-rich sequences raises the possibility of multiple protein-protein interactions. Indeed, BCR-ABL is reported to bind and/or phosphorylate more than 20 proteins. The insights into the signal transduction pathways activated by BCR-ABL will hopefully provide a new basis for the treatment of CML patients. Clinical evidence of the existence of a transplantable CML stem cell population has recently been extended to xenogeneic recipients of transplanted CML cells and by retroviral marking to autograft recipients. The potential of using immunodeficient mice as recipients of CML stem cells to create an in vivo model of chronic phase CML should be invaluable for testing novel therapies designed to eliminate residual disease in the patient. Current therapeutic options include conventional chemotherapy, IFN-a and allogeneic stem cell transplantation as established procedures, and autografting as an experimental procedure. While IFN-a as a first line therapy does not seem to jeopardize further treatments, autografting, according to the Genoa approach or other procedures, i.e. Ph-positive cells collected at diagnosis without mobilization therapy, raises the question of an ideal sequential strategy in the management of CML patients. There seems to be a general agreement that a patient less than 50 years old, with an HLA identical sibling, should receive an allogeneic stem cell transplant. This approach should be offered also to younger patients (< or = 40 years) who are able to find an unrelated matched donor. Since it seems that the normal hematopoietic reservoir declines with time, it may be desiderable to mobilize and collect peripheral stem cells in order to store Ph-negative progenitors as soon after diagnosis as possible when the WBC count has been controlled by hydroxyurea while searchin

Complementary strand analysis: a new approach for allelic separation in complex polyallelic genetic systems

We describe a method, complementary strand analysis (CSA), for separating alleles potentially from any heterozygous genetic locus. Locus specific PCR is performed generating two allelic products. The antisense strands are isolated and hybridised with a sense reference strand to form a chimeric DNA duplex for each allele which is then separated by non-denaturing PAGE. We demonstrate the application of CSA for separation of highly polymorphic HLA-A, -B and -Cw alleles and characterisation of HLA identity in related bone marrow donors and patients. CSA is capable of resolving one nucleotide differences in a DNA fragment nearly as large as a kilobase in length.

Factors influencing the false positive and negative rates of BCR-ABL fluorescence in situ hybridization

BCR-ABL fluorescence in situ hybridization has a useful role to play in experimental and clinical investigations of chronic myeloid leukaemia. However, the interpretation of results is complicated by variability in the false positive rate (FPR) and false negative rate (FNR). We therefore examined the effects on FNR and FPR of three factors, namely, the criteria used for defining a fusion signal, nucleus size, and the genomic position of the ABL breakpoint. We established two different criteria for BCR-ABL positivity: by criterion A cells were scored as positive when BCR and ABL signals were overlapping or touching and by criterion B cells were positive if they satisfied criterion A or if the signals were separated by up to one signal diameter. We measured nucleus size and Philadelphia (Ph) positivity in 573 cells from normal persons and 787 cells from the Ph+ SD-1 cell line and related results to FNRs and FPRs. We also assessed the FNR in Ph+ CFU-GM colonies from five patients with different ABL breakpoints. We showed that each of these factors influenced the FNR and FPR. The less strict criterion (B) for Ph positivity increased the FPR but reduced the FNR, the FPR increased as the nucleus size decreased, and the FNR was greatest in CML cells with a 5' ABL breakpoint. We conclude that these factors should be considered when evaluating the results of FISH studies to detect the BCR-ABL fusion gene and that analogous factors may influence results of FISH studies directed at other fusion genes.

Evidence for early B-cell activation preceding the development of Epstein-Barr virus-negative acquired immunodeficiency syndrome-related lymphoma

To investigate the origin and pathogenesis of acquired immunodeficiency syndrome (AIDS)-related lymphoma (ARL), we studied 14 cases in which Epstein-Barr virus (EBV) infection was not an etiologic factor. By histology, 8 of the specimens were of the small noncleaved cell type and 6 consisted of the large diffuse cell type. Southern analysis using a J(H) probe was consistent with a monoclonal B-cell tumor in 13 cases. To characterize the expressed Ig genes, we performed reverse transcriptase-polymerase chain reaction (RT-PCR) and direct sequencing of PCR products. Eight cases expressed IgM and 1 case expressed IgG. V(H)3 genes were found in 5 cases, V(H)4 genes in 3 cases, V(H)1 genes in 2 cases, and a V(H)7 gene in 1 case. The nucleotide homology to known germline V(H) genes ranged from 80% to 97%, suggesting significant somatic diversification of expressed V(H) genes. The large proportion of V(H)3-expressing lymphomas in this series corresponds to the frequency of V(H)3-expressing B cells in the peripheral blood from healthy and (recent) human immunodeficiency virus (HIV)-seropositve individuals and contrasts with the V(H)3 clonal deficit observed in late stages of HIV infection. Similar to the Ig heavy chain genes, the corresponding Ig light chain genes showed significant deviation from known germline gene sequences. The large proportion of V(H)3-expressing lymphomas as well as the high degree of somatic deviation from germline suggest that these EBV-negative lymphomas might arise from antigen-selected expanded B-cell clones before transformation. Further support for this hypothesis is provided by sequential Ig sequence analysis in 1 patient with large-cell lymphoma. It was shown that 3 years before the diagnosis of axillary lymphoma, there existed several B-cell clones in this patient's bone marrow. One of these clones present in the bone marrow expressed the same rearranged V(H) gene as the axillary lymphoma. Taken together, the current findings from Ig gene analyses suggest that activation of B cells in the early phase of HIV infection may be a predisposing factor for subsequent B-cell transformation.

Applications of virtual reality technology in pathology

TelePath(SM) a telerobotic system utilizing virtual microscope concepts based on high quality still digital imaging and aimed at real-time support for surgery by remote diagnosis of frozen sections. Many hospitals and clinics have an application for the remote practice of pathology, particularly in the area of reading frozen sections in support of surgery, commonly called anatomic pathology. The goal is to project the expertise of the pathologist into the remote setting by giving the pathologist access to the microscope slides with an image quality and human interface comparable to what the pathologist would experience at a real rather than a virtual microscope. A working prototype of a virtual microscope has been defined and constructed which has the needed performance in both the image quality and human interface areas for a pathologist to work remotely. This is accomplished through the use of telerobotics and an image quality which provides the virtual microscope the same diagnostic capabilities as a real microscope. The examination of frozen sections is performed a two-dimensional world. The remote pathologist is in a virtual world with the same capabilities as a "real" microscope, but response times may be slower depending on the specific computing and telecommunication environments. The TelePath system has capabilities far beyond a normal biological microscope, such as the ability to create a low power image of the entire sample using multiple images digitally matched together; the ability to digitally retrace a viewing trajectory; and the ability to archive images using CD ROM and other mass storage devices.

Families of adults with mental retardation: stress levels and need for services

The study described in this article sought to determine whether stress experienced by families of adults with mental retardation was a function of characteristics of caregivers or care recipients, support service needs, and needs for personal care and supervision. Data from interviews with 105 families indicated that the marital status of the caregiver; the level of retardation, frequency of maladaptive behaviors, and health status of the adult family member with mental retardation; and the number and level of services needed were factors in the stress experienced by families. This examination of how perceived stress and needs for services interact provides information essential to developing and funding effective supports to families caring for adults with mental retardation and other developmental disorders.

Brief child assessment battery to assist with treatment planning and program evaluation

A brief battery of self-report measures was constructed to discriminate effectively 45 matched clinic versus nonclinic subjects, ages 8 to 15. The battery consisted of measures from six domains, including externalizing problems, child and parent report of internalizing problems, peer relations, school functioning, and family relationships. Data on subjects and their families were provided by various sources, including parents, teachers, and the children. In an effort to facilitate interpretation and use of this information by unsophisticated staff, within domain scores were converted to bivariate risk scores. Results indicated effective classification (82%) of groups using the bivariate risk scores alone. This constituted only a small loss of information when the risk scores replaced t-scores. Implications for the use of the risk scores to facilitate treatment planning and program evaluation are discussed.

Round table discussion 'gene therapy and society'--summary and conclusions

An international group consisting of scientists, physicians, and one lawyer reported on the problems of gene therapy with regard to society in their respective countries and discussed ethical, legal and scientific aspects of gene therapy. Ethical questions and fear in society were addressed by Dr Odenbach, former Secretary General of the German Medical Association, member of the German Parliamentary Enquiry Commission, 'Prospects and Risks of Gene Technology' and present adviser of the Ethical Committee of the World Medical Association, and by PH Hofschneider, Professor of Virology at the Max-Planck-Institut for Biochemistry, Munich, with a long-time strong interest in medical ethics; legal aspects were addressed by H Hausheer, Professor of Civil Law with many years experience in constitutional law and jurisdiction in Switzerland. Medical and scientific aspects were discussed by R Strohman, Emeritus Professor of Molecular Biology, Berkeley, USA, F Takaku, President of the International Medical Center of Japan and Chairman of the Central Evaluation Committee of the Japanese government for gene therapy, Tokyo and J Goldman, Professor of Leukemia Biology at Hammersmith Hospital, London, and known for this pioneering work in bone marrow transplantation. The discussion was moderated by R Hehlmann, Professor of Medicine at the University of Heidelberg and member of the World Committee of the International Association.

Estimation of body fat and lean tissue distribution by dual energy X-ray absorptiometry and abdominal body fat evaluation by computed tomography in Cushing's disease

Body composition determined by dual energy x-ray absorptiometry and the abdominal visceral fat component determined by computed tomographic scanning were examined in women with Cushing's disease and compared with those in obese women with the same anthropometric parameters and those in nonobese women. Patients with Cushing's had no increase in total body fat or the trunk region (android) component, but had a higher intraabdominal fat area compared to the obese subjects. The total lean tissue mass was slightly reduced in Cushing's compared to that in the obese subjects due to a significant decrease in the muscle of the legs and arms; the reduced amounts of fat and lean tissue masses in the arms were the most significant findings in hypercortisolism. The body mineral and bone calcium contents were slightly reduced in Cushing's compared to those in the obese controls. Thus, although obese subjects had more fat and lean tissue and mineral masses than their normal weight counterparts, the Cushing's patients, with the same total fat mass and its components (except in the arms) as obese individuals, present total lean tissue and fractions, including body mineral and bone calcium contents, similar to those in nonobese subjects due to the depletion of the protein depots, as seen in hypercortisolism.

Judicial decision-making in contested custody cases: the influence of reported child abuse, spouse abuse, and parental substance abuse

This study examined the relationship between allegations of maltreatment and substance abuse, and custody awards in Florida. Information concerning the presence, or absence, of these reports was collected on 60 contested initial disposition, or disposition modification cases, and was used to model judicial decision-making. Substantiated reports of child and spouse abuse occurred very infrequently in our sample. Conversely, substance abuse allegations occurred much more frequently. Judges appeared responsive to allegations of abuse with regard to awards of primary physical residence, despite the lack of substantiated evidence. Maltreatment allegations had no apparent impact, however, on awards of shared, versus sole, custody. Additionally, reports of parental substance abuse also had no apparent impact on judicial decision-making. Implications of these results are discussed.

Immunoglobulin gene sequence analysis to further assess B-cell origin of multiple myeloma

To further characterize the B-cell origin of multiple myeloma, our laboratory performed immunoglobulin gene sequence analyses of four cases of myeloma (three immunoglobulin A and one immunoglobulin G). Three tumors expressed VH3 genes and one expressed a VH1 gene, while the light chains included two V lambda and one V kappa III; one light chain was not isolated. The closest homology to published germ line genes ranged from 91 to 97%. In two cases, the expressed VH genes were compared with the putative germ line precursor VH genes isolated from autologous granulocyte DNA and appeared to have mutated randomly from the germ line gene. By sequencing multiple clonal isolates from each tumor sample, we found no evidence for ongoing mutation in three cases; in one case, however, clonotypic heterogeneity was evident. The analysis of DH- and JH-region genes revealed (i) limited or absent N nucleotide insertions (two of four cases), (ii) the presence of a DH-JH junction resulting from sequence overlap between the DH and JH genes (one of four cases), (iii) the absence of somatic mutations (two of four cases), and (iv) restricted JH gene usage of a JH6 polymorphism (three of four cases). These analyses of DH and JH genes suggest that multiple myeloma, similar to what has been proposed for chronic lymphocytic leukemia, may derive from B cells which have rearranged during fetal development rather than during adult life.

Autologous stem cell transplantation in chronic myelogenous leukemia: a retrospective analysis of the European Group for Bone Marrow Transplantation. Chronic Leukemia Working Party of the EBMT

Over a 3 year period (1989-1991), 49 patients who underwent autologous stem cell transplantation (ASCT) for chronic myelogenous leukemia (CML) in chronic phase were reported to the European Bone Marrow Transplant Registry. Most patients had bad prognostic factors. The results were analyzed by 1 September 1993. Hematological recovery was observed in 45 cases and was significantly quicker after blood stem cell transplantation (n = 30) than after BMT (n = 19). Five patients died early and five other patients did not achieve a complete hematological response (CHR) following ASCT. Of the 39 patients who achieved CHR, 34 are still alive 17 to 52 months after ABSCT. Fifteen of the 34 patients who had cytogenetic evaluation exhibited a major response (> or = 65%, Ph-negative metaphases). The actuarial risk of transformation for the 44 evaluable patients was 28.1 +/- 15% (95% CI) and the actuarial survival at three years was 81.5 +/- 15% (95% CI). No factors were found to significantly influence the response rate or the patients' survival. These encouraging results suggest that ASCT by itself could play a role in prolonging survival in CML patients.

European survey of bone marrow transplantation in acute promyelocytic leukemia (M3). Working Party on Acute Leukemia of the European Cooperative Group for Bone Marrow Transplantation (EMBT)

Acute promyelocytic leukemia (M3) is a distinct subtype of AML considered to have better response to chemotherapy and a higher cure rate than other subtypes. We analyzed the outcome for 362 M3 patients transplanted in Europe from November 1979 to December 1992 and reported to the acute leukemia registry of the European Cooperative Group for Bone Marrow Transplantation (EMBT). Of these 362 patients, 187 received an autograft, 129 in first remission (CR1) and 58 in second remission (CR2), and 175 an allograft, 142 in CR1 and 33 in CR2. Patients autografted in CR1 had at 7 years a leukemia-free survival (LFS) of 48 +/- 5%, a relapse rate (RR) of 41 +/- 5% and a probability of transplant-related mortality (TRM) of 18 +/- 6%. Patients allografted in CR1 had a LFS of 42 +/- 6%, a RR of 28 +/- 5% and a TRM probability of 42 +/- 8%. For patients transplanted in CR2, the respective figures after auto and allotransplantation were: LFS: 31 +/- 7% and 22 +/- 8%, RR: 54 +/- 8% and 64 +/- 11%, TRM: 23 +/- 9% and 40 +/- 9%. These data, which do not permit comparison between autologous and allogeneic BMT, indicate that roughly 45% of M3 patients achieving CR1 may be cured by a marrow transplant. Since the recent use of transretinoic acid-containing induction regimens has increased early control for patients with AML M3, it will be important to find out how these results affect outcome following allogeneic or autologous BMT.

Autologous transplants for chronic myelogenous leukaemia: results from eight transplant groups

Chronic myelogenous leukaemia (CML) can be cured by donor marrow transplant. Unfortunately, suitably HLA-matched related or unrelated donors are not available for the majority of patients. Transplant of stem cells derived from a patient's own marrow or peripheral blood (autologous transplant) avoids the need for an HLA-matched donor, is associated with a less complicated and shorter hospital course than donor transplantation, and has been successful in the treatment of other haematological malignancies. We report results of autologous transplants in 200 patients with CML at eight marrow transplant centres over seven years. This is the first multicentre analysis of autologous transplants for CML and reports on the largest number of patients studied to date. We show that autologous transplants provide a plateau in the survival curve not observed in conventional treatments. Autologous transplants are associated with a high engraftment rate, low mortality, and prompt return of both younger and older patients to normal activity levels. Our results suggest that autologous transplants provide an alternative to conventional treatment in the care of patients not eligible for donor transplant.

Are patients with acute leukaemia, alive and well 2 years post bone marrow transplantation cured? A European survey. Acute Leukaemia Working Party of the European Group for Bone Marrow Transplantation (EBMT)

We investigated the occurrence of late events (beyond 2 years) in patients with acute leukaemia who received an allogeneic (BMT) (n = 1059), or an autologous bone marrow transplantation (ABMT) (n = 656) in Europe during the period from January 1979 to December 1990. Patients with no recurrence of leukaemia at 2 years had overall 82% chance of being alive in complete remission at 9 years following transplantation regardless of the nature of the leukaemia, the status at transplant, and the type of transplant. The incidence of late relapses continuously decreased with time. The latest relapses in acute myelogenous leukaemia (AML) were observed following BMT at 6.6 years in a patient transplanted in first remission (CR1) and at 3.7 years in a patient transplanted in second remission (CR2), and following ABMT at 6 years and 5.1 years respectively. The latest relapses in acute lymphoblastic leukaemia (ALL) were observed following BMT at 4 years in a patient transplanted in first remission (CR1) and at 6.8 years in a patient transplanted in second remission (CR2), and following ABMT at 5.3 years and 4.5 years respectively. Several factors predictive for late relapse or death were identified. Patients allografted experienced a lower frequency of late relapse than patients autografted. Of the numerous other prognostic factors studied, female sex in AML, the use of total body irradiation (TBI) in ALL and status in CR1, rather than CR2-3, for both ALL and AML allografted were correlated with a lower relapse incidence. The use of TBI in ALL was also associated with a better LFS and survival. The absence of acute graft-versus-host disease (GVHD) in allografted AML correlated with better LFS and better survival, but had no influence on the relapse incidence. This study indicates that patients alive and well at 2 years post transplant have a very high probability of being cured, but the possibility of late relapse still remains.