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BACKGROUND Mixed reality (MR) is a hybrid system that projects virtual elements into reality. MR technology has the advantage of providing immersive learning using various real-world tools. However, studies on educational programs using MR are scarce. OBJECTIVE This study aimed to investigate the educational effects of and satisfaction with an MR-based trauma decision-making simulator. METHODS A total 40 of trainees self-selected to participate in this experiment. All participants participated in the MR trauma simulator for approximately 30 minutes and conducted voluntary learning without any external help. Declarative knowledge, measured using 20 multiple-choice questions, was assessed before and after MR trauma training. To confirm the educational effect, test scores before and after MR trauma training were compared using a paired t-test. Student satisfaction after training was measured using a ten-item questionnaire rated on a five-point Likert scale. RESULTS A pretest-posttest comparison yielded a significant increase in declarative knowledge. The percentage of correct answers to multiple choice questions increased (from a mean of 42.3, SD 12.4 to 54.8, SD 13) after the MR-based trauma assessment and treatment training (P < 0.001). Of the participants, 79.45% were satisfied with the overall experience of using the MR simulator. CONCLUSIONS This study demonstrated a meaningful educational effect of the MR-based trauma training system even after a short training time.

The preventable trauma death rate survey is a basic tool for the quality management of trauma treatment because it is a method that can intuitively evaluate the level of national trauma treatment. We conducted this study as a national biennial follow-up survey project and report the results of the review of the 2019 trauma death data in Korea.From January 1, 2019 to December 31, 2019, of a total of 8,482 trauma deaths throughout the country, 1,692 were sampled from 279 emergency medical institutions in Korea. All cases were evaluated for preventability of death and opportunities for improvement using a multidisciplinary panel review approach.The preventable trauma death rate was estimated to be 15.7%. Of these, 3.1% were judged definitive preventable deaths, and 12.7% were potentially preventable deaths. The odds ratio for preventable traumatic death was 2.56 times higher in transferred patients compared to that of patients who visited the final hospital directly. The group that died 1 hour after the accident had a statistically significantly higher probability of preventable death than that of the group that died within 1 hour after the accident.The preventable trauma death rate for trauma deaths in 2019 was 15.7%, which was 4.2%p lower than that in 2017. To improve the quality of trauma treatment, the transfer of severe trauma patients to trauma centers should be more focused.

Background To compare admission lactate and base deficit (BD), which physiologically reflect early hemorrhagic shock, as outcome predictors of pediatric trauma. Methods We reviewed the data of children with trauma who visited a Korean academic hospital from 2010 through 2018. Admission lactate and BD were compared between children with and without primary outcomes. The outcomes included in-hospital mortality, early (≤24 h) transfusion, and early surgical interventions for the torso or major vessels. Subsequently, performances of lactate and BD in predicting the outcomes were compared using receiver operating characteristic curves. Logistic regressions were conducted to identify the independent associations of the two markers with each outcome. Results Of the 545 enrolled children, the mortality, transfusion, and surgical interventions occurred in 7.0%, 43.5%, and 14.9%, respectively. Cutoffs of lactate and BD for each outcome were as follows: mortality, 5.1 and 6.7 mmol/L; transfusion, 3.2 and 4.9 mmol/L; and surgical interventions, 2.9 and 5.2 mmol/L, respectively. No significant differences were found in the areas under the curve for each outcome. Of the two markers, a lactate of >5.1 mmol/L was associated with mortality (adjusted odds ratio, 6.43; 95% confidence interval, 2.61-15.84). A lactate of >3.2 mmol/L (2.82; 1.65-4.83) and a BD of >4.9 mmol/L (2.32; 1.32-4.10) were associated with transfusion, while only a BD of >5.2 mmol/L (2.17; 1.26-3.75) was done with surgical interventions. Conclusions In pediatric trauma, lactate is more strongly associated with mortality. In contrast, BD may have a marginally stronger association with the need for hemorrhage-related procedures.

The splenic surface can be anatomically divided into the visceral surface connected to major blood vessels and the diaphragmatic surface attached to the diaphragm. This study aimed to investigate differences in future treatment and outcomes according to the anatomical location of splenic injuries following abdominal trauma. Patients who were treated at a single trauma center between January 2011 and April 2018 were included. The presence of lacerations or hematoma on the visceral surface was evaluated via computed tomography. Differences in the location of splenic surgery between a group that underwent surgical or radiologic intervention and a group that received conservative care only were analyzed. Of 355 patients with splenic injury analyzed, the total mortality rate was 15.2%. A total of 167 patients underwent surgery and angiographic embolization, and 168 received conservative care only. Splenic injuries involved the visceral surface in 127 and 105 patients in the respective groups. Significant differences in the incidence of splenic injuries involving the visceral surface were found between the two groups in the univariate and logistic regression analyses. The likelihood of needing surgery and treatments such as embolization was higher for cases of splenic injury involving the visceral surface than for splenic injuries that did not involve the visceral surface. Through additional research, it may become possible to analyze the location of a splenic injury to determine an effective and safe method of treatment and accurately predict a prognosis. Clin. Anat. 33:516-521, 2020. © 2019 Wiley Periodicals, Inc.

Background We evaluated the accuracy of the prehospital Field Triage Decision Scheme, which has recently been applied in the Korean trauma system, and the factors associated with severe injury and prognosis at a regional trauma center in Korea. Methods From 2016 to 2018, prehospital data of injured patients were obtained from the emergency medical services of the national fire agency and matched with trauma outcomes at our institution. Severe injury (Injury Severity Score > 15), overtriage/undertriage rate, positive predictive value, negative predictive value, and accuracy were reviewed according to the triage protocol steps. A multivariate logistic regression analysis was performed to identify influencing factors in the field triage. Results Of the 2438 patients reviewed, 853 (35.0%) were severely injured. The protocol accuracy was as follows: step 1, 72.3%; step 2, 65.0%; step 3, 66.2%; step 1 or 2, 70.2%; and step 1, 2, or 3, 66.4%. Odds ratios (OR) (95% confidence interval [CIfor systolic blood pressure p p p = 0.04) were significantly associated with 24-h mortality. Penetrating torso injuries (7.108 [4.108–12.300]; p p p p p Conclusion The Korean field triage protocol is not yet accurate, with only some factors reflecting injury severity, making reevaluation necessary.

Background: Although South Korea is a high-income country, its trauma system is comparable to that of low- and middle-income countries (LMICs) with high preventable trauma death rates (PTDRs) (>30%). Since 2012, South Korea has established a national trauma system based on the implementation of regional trauma centers (RTCs) and improvement of the transfer system; this study evaluated its effectiveness. Methods: We compared the national PTDRs, transfer patterns, and outcomes between 2015 and 2017. The trauma death review was conducted by multiple panels and a severity-adjusted logistic regression model was created to identify factors influencing the PTDR. We also compared the number of trauma patients transferred to emergency medical institutions and mortality in models adjusted with injury severity scores. Findings: The PTDR decreased from 2015 to 2017 (30·5% vs. 19·9%, p

Background This study examined the impact of the performance improvement and patient safety (PIPS) program implemented in 2015 on outcomes for trauma patients in a regional trauma center established by a government-led project for a national trauma system in Korea. Methods The PIPS program was based on guidelines by the World Health Organization and American College of Surgeons. The corrective strategies were proceeded according to the loop closure principle: data-gathering and monitoring, identification of preventable trauma deaths (PTDs), evaluation of preventable factors, analysis of findings, and corrective action plans. We established guidelines and protocols for trauma care, conducted targeted education and peer review presentations for problematic cases, and enhanced resources for improvement accordingly. A comparative analysis was performed on trauma outcomes over a four-year period (2015–2018) since implementing the PIPS program, including the number of trauma team activation and admissions, time factors related to resuscitation, ventilator duration, and the rate of PTDs. Results Human resources in the center significantly increased during the period; attending surgeons responsible for trauma resuscitation from 6 to 11 and trauma nurses from 85 to 218. Trauma admissions (from 2,166 to 2,786), trauma team activations (from 373 to 1,688), and severe cases (from 22.6 to 33.8%) significantly increased (all P < 0.001). Time to initial resuscitation and transfusion significantly decreased from 120 to 36 minutes (P < 0.001) and from 39 to 16 minutes (P < 0.001). Time to surgery for hemorrhage control and decompressive craniotomy improved from 99 to 54 minutes (P < 0.001) and 181 to 135 minutes (P = 0.042). Ventilator duration and rate of PTDs significantly decreased from 6 to 4 days (P = 0.001) and 22.2% to 8.4% (P = 0.008). Conclusion Implementation of the PIPS program resulted in improvements in outcomes at a regional trauma center that has just been opened in Korea. Further establishment of the PIPS program is required for optimal care of trauma patients., Graphical Abstract

OBJECTIVES Children have a larger reserve for traumatic hemorrhagic shock, requiring a score that uses physiologic variables other than hypotension. Recently, the BIG score comprising admission base deficit, international normalized ratio, and the Glasgow Coma Scale has been reported to predict traumatic mortality. We aimed to validate the performance of the BIG score in mortality prediction of normotensive children with trauma. METHODS We reviewed 1046 injured children (

OBJECTIVE Suicide is a major issue in South Korea, and falling is a common method of suicide. Further, accidental falls are a common cause of death. However, whether suicidal falls differ from accidental falls is inconclusive. This study aimed to compare suicidal and accidental falls to identify risk factors for mortality. METHODS From March 2010 to December 2016, patients admitted to our hospital because of falls were reviewed retrospectively. Characteristics and outcomes were compared between suicide and accident groups. Injury distribution was compared using the Injury Severity Score and Abbreviated Injury Scales. Multivariate analysis was performed to identify risk factors, including suicide intent, for mortality. RESULTS Of 242 patients, 42 were included in the suicide group and 200 were included in the accident group. The suicide group showed higher fall heights and injuries of greater severity. The accident group was younger and included a higher number of men. The suicide group showed a higher mortality (23.8% vs. 6.5%, P=0.001) and a higher proportion of injuries in the lower extremities or abdomen. In the multivariate analysis, Glasgow Coma Scale score (0.575 [0.433-0.764], P

Gyeonggi-do (Gyeonggi province) has the second highest number of coronavirus disease (COVID-19) cases in the Republic of Korea after Seoul, with approximately 25% of the COVID-19 patients as of January 2021. Our center is a level I trauma center located in south Gyeonggi-do, and we aimed to evaluate whether the characteristics of trauma patients changed after the COVID-19 pandemic. We retrospectively reviewed the trauma patients registered with the Korea Trauma Database of the Center from February 2019 to January 2021. The patients were dichotomized into pre-coronavirus disease (pre-COVID) and coronavirus disease (COVID) groups, and their trauma volumes, injury characteristics, intentionality, and outcomes were compared. A total of 2628 and 2636 patients were included in the pre-COVID and COVID groups, respectively. During the COVID-19 period, motorcycle accidents, bicycle accidents, and penetrating injury cases increased, and pedestrian traffic accidents, slips, and injury by machines decreased. The average daily number of patients in the COVID group was lower in March (5.6 ± 2.6/day vs 7.2 ± 2.4/day, P = .014) and higher in September (9.9 ± 3.2/day vs 7.7 ± 2.0/day, P = .003) compared to the pre-COVID group. The COVID group also had a higher ratio of direct admissions (67.5% vs 57.2%, P

A new blood bank system was established in our trauma bay, which allowed immediate utilization of uncross-matched type O packed red blood cells (UORBCs). We investigated the efficacy of UORBC compared to that of the ABO type-specific packed red blood cells (ABO RBCs) from before the bank was installed. From March 2016 to February 2017, data from trauma patients who received UORBCs in the trauma bay were compared with those of trauma patients who received ABO RBCs from January 2013 to December 2015. Propensity matching was used to overcome retrospective bias. The primary outcome was 24-hour mortality, while the secondary outcomes were in-hospital mortality and intensive care unit (ICU) length of stay (LOS). Data from 252 patients were reviewed and UORBCs were administered to 64 patients. The time to transfusion from emergency room admission was shorter in the UORBC group (11 [7–16] minutes vs. 44 [29–72] minutes, P < 0.001). After propensity matching, 47 patients were included in each group. The 24-hour mortality (4 [8.5%] vs. 9 [13.8%], P = 0.135), in-hospital mortality (14 [29.8%] vs. 18 [38.3%], P = 0.384), and ICU LOS (9 [4–19] days vs. 5 [0–19] days, P = 0.155) did not differ significantly between groups. The utilization of UORBCs resulted in a faster transfusion but did not significantly improve the clinical outcomes in traumatic shock patients in this study. However, the tendency for lower mortality in the UORBC group suggested the need for a large study., Graphical Abstract

PURPOSE This study was designed to provide a basis for building a master plan for a regional trauma system by analyzing the distribution of trauma deaths in the most populous province in Korea. MATERIALS AND METHODS We investigated the time distribution to death for trauma patients who died between January and December 2017. The time distribution to death was categorized into four groups (within a day, within a week, within a month, and over a month). Additionally, the distribution of deaths within 24 hours was further analyzed. We also reviewed the distribution of deaths according to the cause of death and mechanism of injury. RESULTS Of the 1546 trauma deaths, 328 cases were included in the final study population. Patients who died within a day were the most prevalent (40.9%). Of those who died within a day, the cases within an hour accounted for 40.3% of the highest proportion. The majority of trauma deaths within 4 hours were caused by traffic-related accidents (60.4%). The deaths caused by bleeding and central nervous system injuries accounted for most (70.1%) of the early deaths, whereas multi-organ dysfunction syndrome/sepsis had the highest ratio (69.7%) in the late deaths. Statistically significant differences were found in time distribution according to the mechanism of injury and cause of death (p

Resuscitative thoracotomy (RT) can be a lifesaving treatment, but it has not yet been performed in Korea. In this study, we review our experience of RT after a regional trauma center was constructed. This is a retrospective study of RT conducted at a single Korean trauma center from May 2014 to March 2018. The primary outcome was survival, and the secondary outcome was return of spontaneous circulation (ROSC). The clinical characteristics of the patients were compared between the ROSC and non-ROSC groups. Survivors were also reviewed. A total of 62 patients were reviewed, and 60 patients had experienced blunt injury. Thirty-nine patients had ROSC. The ROSC group had short cardiopulmonary resuscitation (CPR) time (6 [2–10] min vs 11 [8–12] min, p

Purpose Base deficit (BD) is superior to vital signs in predicting trauma outcomes in adults. The authors aimed to compare BD and vital signs as criteria for the four-tiered hemorrhagic shock classification in children with trauma. Materials and Methods We retrospectively reviewed the data of 1046 injured children who visited a Korean academic hospital from 2010 through 2018. These children were classified separately based on BD (class I, BD ≤2.0 mmol/L; II, 2.1–6.0 mmol/L; III, 6.1–10 mmol/L; and IV, ≥10.1 mmol/L) and vital signs (

Background: Injury severity scoring systems that quantify and predict trauma outcomes have not been established in Korea. This study was designed to determine the best system for use in the Korean trauma population. Methods: We collected and analyzed the data from trauma patients admitted to our institution from January 2010 to December 2014. Injury Severity Score (ISS), Revised Trauma Score (RTS), and Trauma and Injury Severity Score (TRISS) were calculated based on the data from the enrolled patients. Area under the receiver operating characteristic (ROC) curve (AUC) for the prediction ability of each scoring system was obtained, and a pairwise comparison of ROC curves was performed. Additionally, the cut-off values were es-timated to predict mortality, and the corresponding accuracy, positive predictive value, and negative predictive value were obtained. Results: A total of 7,120 trauma patients (6,668 blunt and 452 penetrating injuries) were enrolled in this study. The AUCs of ISS, RTS, and TRISS were 0.866, 0.894, and 0.942, respectively, and the prediction ability of the TRISS was significantly better than the others (p < 0.001, respectively). The cut-off value of the TRISS was 0.9082, with a sensitivity of 81.9% and specificity of 92.0%; mortality was pre-dicted with an accuracy of 91.2%; its positive predictive value was the highest at 46.8%. Conclusions: The results of our study were based on the data from one institution and suggest that the TRISS is the best prediction model of trauma outcomes in the current Korean population. Further study is needed with more data from multiple centers in Korea.

For trauma patients with severe shock, massive fluid resuscitation is necessary. However, shock and a large amount of fluid can cause bowel and retroperitoneal edema, which sometimes leads to abdominal compartment syndrome in patients without abdomino-pelvic injury. If other emergent operations except intraabdomen are needed, a distended abdomen is likely to be recognized late, leading to multiple organ dysfunction. Herein, we report two cases of a 23-year-old woman who was in a car accident and a 53-year old man who was pressed on his leg by a pressing machine; severe brain swelling and popliteal vessel injury were diagnosed, respectively. They were both in severe shock and massive fluid resuscitation was required in the emergency department. Distended abdomen was recognized in both the female and male patients immediately after neurosurgical operation and immediately before orthopaedic operation in the operating room, respectively. Decompressive laparotomy revealed massive ascites with retroperitoneal edema.

Background: We hypothesized that the recent change of sepsis definition by sepsis-3 would facilitate the measurement of timing of sepsis for trauma patients presenting with initial systemic inflammatory response syndrome. Moreover, we investigated factors associated with sepsis according to the sepsis-3 definition. Methods: Trauma patients in a single level I trauma center were retrospectively reviewed from January 2014 to December 2016. Exclusion criteria were younger than 18 years, Injury Severity Score (ISS)

Objective Acute transverse myelitis (ATM) is characterized by motor weakness, sensory changes, and autonomic dysfunction. However, diagnosis of ATM is based on early-stage clinical features only (and clarification of the cause of disease), which are difficult for emergency department (ED) physicians owing to low incidence rates. We performed retrospective analysis of ATM in order to provide clinical insights for early detection. Methods Medical records of patients, who were finally diagnosed with ATM from January 2005 to February 2013, were investigated. Data, including demographics, clinical findings, and radiographic findings, were reviewed. Results Forty-six patients were included in the present study, with a mean age of 43.4 years. Sensory changes were identified in 45 patients (97.8%), motor weakness in 33 patients (71.7%), and autonomic dysfunction in 35 patients (76.1%). Thirty patients (65.2%) showed high signal intensity in T2-weighted magnetic resonance imaging (MRI), with lesions most frequently found in the thoracic level of the spinal cord (56.7%). There were discrepancies between sensory changes and levels of MRI lesions. Thirty-five patients (76.1%) were diagnosed with idiopathic ATM. Initial diagnostic impressions in the ED were herniated intervertebral disc (38.7%), stroke (19.4%), Guillain-Barré syndrome (12.9%), cauda equina syndrome (9.7%), ATM (9.7%), and others (9.7%). Conclusion When a patient presents with motor weakness, sensory changes, or autonomic dysfunction, ATM should be initially considered as a differential diagnosis, unless the ED physician’s impression after initial evaluation is clear.

PURPOSE: The purpose of this study was to verify the utility of existing Trauma and Injury Severity Score (TRISS) coefficients and to propose a new prediction model with a new set of TRISS coefficients or predictors. MATERIALS AND METHODS: Of the blunt adult trauma patients who were admitted to our hospital in 2014, those eligible for Korea Trauma Data Bank entry were selected to collect the TRISS predictors. The study data were input into the TRISS formula to obtain "probability of survival" values, which were examined for consistency with actual patient survival status. For TRISS coefficients, Major Trauma Outcome Study-derived values revised in 1995 and National Trauma Data Bank-derived and National Sample Project-derived coefficients revised in 2009 were used. Additionally, using a logistic regression method, a new set of coefficients was derived from our medical center's database. Areas under the receiver operating characteristic (ROC) curve (AUC) for each prediction ability were obtained, and a pairwise comparison of ROC curves was performed. RESULTS: In the statistical analysis, the AUCs (0.879-0.899) for predicting outcomes were lower than those of other countries. However, by adjusting the TRISS score using a continuous variable rather than a code for age, we were able to achieve higher AUCs [0.913 (95% confidence interval, 0.899 to 0.926)]. CONCLUSION: These results support further studies that will allow a more accurate prediction of prognosis for trauma patients. Furthermore, Korean TRISS coefficients or a new prediction model suited for Korea needs to be developed using a sufficiently sized sample. Language: en

Bursty continuous media streams with periodic playout deadlines (e.g., VBR-encoded video) are expected to account for a large portion of the traffic in the future Internet. By prefetching parts of ongoing streams into client buffers these bursty streams can be more efficiently accommodated in packet-switched networks. In this paper we develop a modular algorithm-theoretic framework for the fair and efficient transmission of continuous media over a bottleneck link. We divide the problem into the two subproblems of (i) assuring fairness, and (ii) efficiently utilizing the available link capacity. We develop and analyze algorithm modules for these two subproblems. Specifically, we devise a bin packing algorithm for subproblem (i), and a "layered prefetching" algorithm for subproblem (ii). Our simulation results indicate that the combination of these two algorithm modules compares favorably with existing monolithic solutions. This demonstrates the competitiveness of the decoupled modular algorithm framework, which provides a foundation for the development of refined algorithms for fair and efficient prefetching.

In Korea, which still lacks a well-established trauma care system, the inability to transport patients to adequate treatment sites in a timely manner is a cause of low trauma patient survival. As such, this study was conducted to serve as a basis for the establishment of a future trauma transport system. We performed a comparative analysis of the transport time, and treatment outcomes between trauma victims transported by ground ambulance (GAMB) and those transported via the helicopter emergency medical service (HEMS) through the National Emergency Management Agency's 119 reporting system, which is similar to the 911 system of the United States, from March 2011 to May 2014. The HEMS-transported patients received treatment instructions, by remote communication, from our trauma specialists from the time of accident reporting; in certain instances, members of the trauma medical staff provided treatment at the scene. A total of 1,626 patients were included in the study; the GAMB and HEMS groups had 1,547 and 79 patients, respectively. The median transport time was different between 2 groups (HEMS, 60 min vs. GAMB, 47 min, P

Apheresis-derived hematopoietic progenitor cells have recently been used for allogeneic transplantation. Forty-one normal donors were studied to assess the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) (12 micrograms/kg/d) on the peripheralization of hematopoietic progenitor cells and lymphoid subsets. The white blood cell, polymorphonuclear cell (PMNC), and lymphocyte concentrations at the peak of rhG-CSF effect in the donor's peripheral blood (PB) exceeded baseline by 6.4-, 8.0-, and 2.2-fold, respectively. Corresponding concentrations of PB CD34+ cells and primitive subsets such as CD34+ Thy-1dim, and CD34+ Thy-1dim CD38- cells increased by 16.3-fold, 24.2-fold, and 23.2-fold, respectively in eight normal donors. The percentage of CD34+ Thy-1dim and CD34+ Thy- 1dim CD38- cells among CD34+ cells increased as well, suggesting an additional peripheralization effect of rhG-CSF on primitive CD34+ subsets. The preapheresis PB CD34+ and CD34+ Thy-1dim cell concentrations were predictive of their corresponding apheresis yield per liter of donor blood processed PB lymphoid subsets were not significantly affected by rhG-CSF treatment. The mean apheresis-derived yield of CD34+, CD34+ Thy-1dim, and CD34+ Thy-1dim CD38- cells per kilogram of recipient body weight and per liter of donor blood processed was 48.9 x 10(4) (n = 41), 27.2 x 10(4) (n = 10), and 1.9 x 10(4) (n = 10), respectively. As compared with 43 single bone marrow (BM) harvest, the CD34+ cell yield of peripheral blood progenitor cell allografts of 41 normal donors exceeded that of BM allografts by 3.7- fold and that of lymphoid subsets by 16.1-fold (CD3+), 13.3-fold (CD4+), 27.4-fold (CD8+), 11.0-fold (CD19+), and 19.4-fold (CD56+CD3-). All PBPC allografts were cryopreserved before transplantation. The mean recovery of CD34+ cells after freezing, thawing, and washing out dimethylsulfoxide was 86.6% (n = 31) and the recovery of lymphoid subsets was 115.5% (CD3+), 121.4% (CD4+), 105.6% (CD8+), 118.1% (CD19+), and 102.4% (CD56+CD3-). All donors were related to patients: 39 sibling-to-sibling, 1 parent-to-child, and 1 child-to-parent transplant. Thirty-eight transplants were HLA fully identical, two transplants differed in one and two antigens. Engraftment occurred in 38 recipients; two patients died too early to be evaluated, and one patient did not engraft. The lowest CD34+ cell dose transplanted and resulting in complete and sustained engraftment was 2.5 x 10(6)/kg of recipient body weight.(ABSTRACT TRUNCATED AT 400 WORDS)

The chromosomal translocation t(15;17)(q22:21) of acute promyelocytic leukemia (APL) fuses PML, a novel gene, with RAR alpha, a retinoic acid receptor gene. PML-RAR hybrid transcripts were studied in 18 cases of APL using RNA-PCR. Two forms were noted: one designated 5′, producing a 439-bp chimeric fragment, and a 3′ form, producing a pair of fragments of 765 bp and 909 bp. 5′ forms were found in 7 of the 18 cases while the other 11 patients expressed the 3′ forms. The chromosome 15 specific probes K3 and K2 were used to study genomic breakpoints in 12 APL patients. Comparison of these results with RNA PCR in 11 patients for whom both were available yielded a rearrangement pattern predictive of whether the hybrid transcript was 5′ or 3′. In this way, an additional three patients in whom DNA but not RNA was available were identified as having 3′ (downstream) breakpoints and, therefore, 3′ hybrid forms. Thus, 21 cases categorized as having 5′ or 3′ PML-RAR transcripts were analyzed for various phenotypic differences. Surface phenotyping of leukemic promyelocytes demonstrated expression of the CD2 antigen in all cases with the 5′ splice variant. Only 1 of 11 cases with the 3′ form showed CD2 expression. This difference is significant at P = .001.

The goals of this study were to evaluate the response to treatment in chronic lymphocytic leukemia (CLL) according to clinical, pathologic, immunophenotypic, and molecular features, as well as to address the clinical significance of each finding. One hundred fifty-nine CLL patients with either advanced Rai stage III or IV (81 patients) or progressive Rai stage 0 to II (78 patients) were treated with fludarabine (30 mg/m2/d intravenously every day for 5 days) plus prednisone (30 mg/m2/d orally daily for 5 days). Thirty-six patients were previously untreated. The response rates were 12% complete response (CR), 30% nodular complete response (nCR), and 18% partial response (PR). In all patients who achieved a complete response (both CR and nCR) less than 30% of nucleated cells were lymphocytes on marrow aspirate differential analysis; however, nCR patients had residual nodular and/or interstitial lymphocyte involvement on marrow biopsy examination. There was no evidence of leukemic infiltration on marrow biopsy examination in CR patients. With a median follow-up of 35 months, comparison of time to progression in the CR and nCR groups at 2 years showed a projected 87% versus 55% progression-free survival (P less than .03). Residual disease assessment by flow cytometry using simultaneous dual-color staining on blood and marrow lymphocytes was also performed on each patient. Residual disease was determined by the expression of CD5 on B lymphocytes and the monoclonality of surface light-chain expression. After six courses of fludarabine plus prednisone, no residual disease was detected by flow cytometry in 89% of the CRs, 51% of the nCRs, and 19% of the PRs. Clinical residual disease in PR patients with no residual disease detectable by flow cytometry was limited to lymph-adenopathy. Time to progression at 2 years was longer in CR and nCR patients having no residual disease detected by flow cytometry (84% v 39% 2-year progression-free survival, P less than .001). Posttreatment lg gene rearrangement analysis using JH, J kappa, and C lambda probes demonstrated no rearranged bands and a return to the germline configuration in five of seven CRs and two of eight nCRs studied. The molecular studies were concordant with the dual- parameter immunophenotype results and none of the patients who reverted to a germline DNA pattern after treatment have experienced relapse. The absence of detectable minimal residual disease by bone marrow biopsy, dual-color flow cytometry, and lg gene rearrangement analysis is achieveable in CLL with fludarabine and is predictive of the response duration.

We administered one course of 2-chlorodeoxyadenosine (2CdA) at 4 mg/m2 daily for 7 days by continuous intravenous infusion to 46 patients with hairy cell leukemia. Complete remissions occurred in 36 patients (78%; 95% confidence limits, 63% to 89%), partial remissions in five (11%), and a minor response in one. One patient died of candida sepsis 3 weeks after beginning treatment and three patients were clearly resistant to therapy. These three either had morphologically atypical hairy cells, less than 20% of which expressed Ig light chain on the cell surface, or had failed prior treatment with deoxycoformycin and interferon-alpha. At a median of 37 weeks since discontinuation of therapy, recurrent thrombocytopenia has developed in one patient, whose marrow remains normal, while a bone marrow relapse has occurred in another patient, whose blood counts remain normal. Treatment produced a greater than 50% decrease in neutrophil count in 26 patients, which lasted 3 to 4 weeks and was associated with an increased incidence of febrile episodes. These episodes occurred in 21 patients but were associated with documented infection in only four patients. Decreases in the number of CD4+ lymphocytes appeared to occur regularly after treatment and have persisted for a median of 18 weeks without obvious clinical significance. Although years of follow-up will be needed, our results confirm Piro et al's observation (N Engl J Med 322: 1117, 1990) that 2CdA appears to be highly effective in the treatment of hairy cell leukemia.

Automation is an essential component in today's semiconductor manufacturing. As factories migrate to 300 mm technology, automated handling becomes increasingly important for variety of ergonomic, safety, and yield considerations. Traditional semiconductor AMHS systems, such as the Overhead Monorail Vehicles (OMV) or Overhead Hoist, can be overly expensive. Cost projections for a 300 mm inter/intrabay AMHS installation are in the range of $50 M-$100 M. As an alternative, a lower cost alternative AMHS, called Continuous Flow Transport has been proposed. The CFT system is similar to what has historically been identified as a conveyor based movement system. The CFT system provides cost savings at reduced flexibility and longer delivery time. This study compares the CFT to Overhead Monorail transport, determining a cumulative delivery time distribution. As expected, the CFT system requires a longer average delivery time interval than OMV, but may provide total savings through reduced transport variability.

Immunophenotypes for 272 patients with acute myelogenous leukemia (AML) were analyzed using a panel of 22 antibodies. Numerical evidence for unusual coexpressions (present in normal marrow at < or = 0.1%) of surface markers on = or = 10% of the blast cells was found in 85% of all cases. Asynchronous expression of myeloid differentiation antigens occurred in 70% of the cases. Unusual coexpression of T-lymphoid, B- lymphoid, or natural killer (NK) markers with myeloid markers occurred in 38%, 13%, and 21%, respectively, of all AML cases. Two- and three- color analyses confirmed coexpression in 15 of 15 cases, and indicated that these percentages are an underestimate, because coexpression can be demonstrated in cases without numerical overlap. These data indicate that the unusual coexpression of normal differentiation antigens is a common occurrence in AML. Markers in 12 of 13 patients were similar between presentation and relapse, and in two patients, unusual phenotypes detected at first relapse were shown at second relapse, indicating these immunophenotypes are stable in the majority of AML patients. Significant correlations were found between t(8;21) cytogenetics and coexpression of CD19 with CD15 or CD34, t(9;22) and coexpression of CD19 and CD34, and t(15;17) and coexpression of CD2 and myeloid antigens. Multiparameter fluorescence analysis allows detection of unusual phenotypes when the blast counts are < 5% (classical remission). Analysis of 16 patients in remission indicated the presence of presentation phenotypes in 0.2% to 7.9% of the lymphocyte + blast light scatter region, representing 0.03% to 1.4% of the total nucleated marrow cells. Of the 16 patients with = or = 4 months follow-up after detection of these cells, 6 of 6 patients with = or = 0.2% unusual presentation phenotypic marrow cells have relapsed, while 9 of 10 patients with < 0.2% remain in remission. The detection of cells with the unusual presentation phenotype may reflect residual AML cells, and their increase may predict relapse.

We report five patients who had greater than 30% peripheral blasts and less than 30% marrow blasts. By the current standards these cases would be classified as myelodysplastic syndrome. Four of five patients progressed to acute leukemia within approximately 1 1/2 months of developing greater than 30% peripheral blasts. Two of these four patients had evidence of acute leukemia by criteria other than marrow involvement at the time of presentation: one patient had evidence of multifocal dermal involvement; and the other patient had a cytogenetic abnormality, t(8;21), found predominantly in acute leukemia. The fifth patient developed acute leukemia 2 years after initial presentation with greater than 30% peripheral blasts. Although our series of patients is small, it does suggest that patients who have greater than 30% peripheral blasts should be considered an acute leukemia, even with less than 30% marrow blasts.