Development of Medical Imaging Data Standardization for Imaging-Based Observational Research: OMOP Common Data Model Extension

The rapid growth of artificial intelligence (AI) and deep learning techniques require access to large inter-institutional cohorts of data to enable the development of robust models, e.g., targeting the identification of disease biomarkers and quantifying disease progression and treatment efficacy. The Observational Medical Outcomes Partnership Common Data Model (OMOP CDM) has been designed to accommodate a harmonized representation of observational healthcare data. This study proposes the Medical Imaging CDM (MI-CDM) extension, adding two new tables and two vocabularies to the OMOP CDM to address the structural and semantic requirements to support imaging research. The tables provide the capabilities of linking DICOM data sources as well as tracking the provenance of imaging features derived from those images. The implementation of the extension enables phenotype definitions using imaging features and expanding standardized computable imaging biomarkers. This proposal offers a comprehensive and unified approach for conducting imaging research and outcome studies utilizing imaging features.

Definitive Radiotherapy in Patients with Clinical T1N0M0 Esophageal Squamous Cell Carcinoma: A Multicenter Retrospective Study

PURPOSE/OBJECTIVE(S)

In this study, we aimed to assess the failure pattern and survival outcomes and to analyze the optimal treatment field of definitive RT for T1N0M0 esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

We performed a retrospective analysis in a multi-institutional cohort of patients with histologically confirmed T1N0M0 ESCC. We included patients who underwent RT with definitive aim from 2010 to 2019. Patterns of failure were demonstrated as in-field locoregional, out-field locoregional and distant metastasis. In the survival analysis, freedom from locoregional recurrence and their association with clinicopathologic risk factors were analyzed. We performed a propensity score matching in the cT1b patients to adjust for the heterogeneity of radiation technique, radiation dose and the use of concurrent chemotherapy.

RESULTS

A total of 168 patients were included with a median follow-up of 34.0 months, and there were 20 cT1a, 94 cT1b and 24 cT1x, (cT1, not otherwise specified) patients. The rates of all and locoregional failure were 26.9% and 23.1% for cT1a and 25.0% and 22.4% for cT1b patients. 10 (10.6%) patients experienced grade ≥ 3 adverse events. Among 116 cT1b patients, 69 patients received elective nodal irradiation (ENI) and 47 patients received involved field irradiation (IFI). After propensity score matching, the 3-year FFLRR rate was 84.5% (95% Confidence Interval, 71.0 - 92.1%). There was no significant difference between the ENI and IFI patients in FFLRR (Log-rank P = 0.831). In the multivariate analysis, the use of concurrent chemotherapy was the only factor marginally associated with FFLRR (Hazard ratio, 0.17; 95% CI, 0.02 - 1.13; P = 0.067).

CONCLUSION

cT1a patients who cannot receive endoscopic resection, showed similar rates of failure compared with cT1b patients, which questioned the accuracy of the staging and raised the need for through treatment such as chemoradiotherapy. In cT1b patients, IFI using dose of 50 to 60 Gy with concurrent chemotherapy could be a reasonable treatment option.

Evaluation of the Neonatal Sequential Organ Failure Assessment and Mortality Risk in Neonates with Early-Onset Infection

BACKGROUND

The discriminative utility of the neonatal sequential organ failure assessment (nSOFA) for early-onset sepsis (EOS) mortality in the neonatal intensive care unit (NICU) is unknown.

OBJECTIVES

The objective of the study was to determine the utility of nSOFA for EOS mortality.

METHODS

Multicenter, retrospective cohort study of NICU patients with EOS between 2012 and 2023. nSOFA scores of survivors and non-survivors were compared, and area under the receiver operating characteristics curve (AUROC) for mortality was calculated.

RESULTS

104 subjects were identified (88 lived, 16 died). AUROC at blood culture collection (T0), 6 h after collection (T6), and the maximum nSOFA at T0 or T6 (T0-6max) were 0.76 (95% CI: 0.62, 0.91), 0.89 (0.80, 0.99), and 0.87 (0.77, 0.97), respectively. Analyses restricted to birthweight (<1.5, <1 kg) or gestational age (<32, <29 week) cutoffs revealed AUROC ranges of 0.86-0.92 for T6 and 0.82-0.84 for T0-6max.

CONCLUSIONS

The nSOFA showed good-to-excellent discrimination of mortality among infants with EOS in the NICU.

Methods of implementation for an electronic ongoing professional practice evaluation system

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Background: Hospitals accredited by the Joint Commission are required to provide Ongoing Professional Practice Evaluation (OPPE) for all privileged providers. Historically, OPPE reports had been created and completed by a peer review process on a paper-based system, where the data was managed in spreadsheets. The Division of Quality and Safety (DQS) developed an electronic system of collecting clinical and administrative data, with the goal of assessing quality of care in an impartial, modernized, and efficient process. Methods: Electronic implementation of the OPPE process can be divided into three main parts: metric development using electronic medical records (EMR), report automation, and application development for review. We designed queries to extract EMR data to validate the quality measures developed in collaboration with clinical leadership. Data pulls are then automated to populate outcomes to a table, from which the OPPE reports are populated according to selected parameters such as provider’s unique ID and OPPE period. Reports are then accessed by supervisors and providers directly through a web application developed by DQS. After verifying the data, clinicians can sign off in the application to complete the OPPE review process. Results: We have distributed 8,630 electronic OPPE report since 2012, and 1,486 distinct physicians had received reports. We evaluated engagement of the process by looking at engagement rate (number of OPPE signed reports divided by the total number of OPPE reports). The engagement rate varies by department, but the median of engagement rates of the OPPE process is 100%. Conclusions: Moving from paper chart reviews to an electronic process enables the institution to scale, lower the burden on employees, and improve the convenience of OPPE for busy providers. It also provides opportunities to evaluate quality of care on the provider level by analyzing outliers using the OPPE measure outcomes and finding the correlation of engagement rate and the quality outcomes.

Is the Clinical Outcome Good or Bad in Patients Hospitalized Within 1 Year After Kidney Transplantation?

BACKGROUND

Although the hospitalization rate at early period of kidney transplantation (KT) is still high, the association between the hospitalization within 1 year after KT and graft survival is unclear. We investigated the incidence and causes of hospitalization and clinical outcome of the patients hospitalized within 1 year after KT.

METHODS

We retrospectively analyzed 174 KT recipients (KTRs) hospitalized within 1 year after KT between 2013 and 2015.

RESULTS

Among them, 84 (48%) KTRs were admitted within 1 year after KT, and the number of hospitalizations was 116. The mean time from KT to first hospitalization was 4.2 months. Seventy-eight percent of the patients were hospitalized for medical causes and 22% for surgical causes. The most common cause was cytomegalovirus infection (CMV) (23.3%), followed by acute rejection (11.2%) and urinary tract infection (10.3%). Recipients and donors in the hospitalized group were significantly older than the nonhospitalized group. The proportions of deceased donor KT, acute rejection, more than 50% panel-reactive antibody, and positive donor-specific antibody were significantly higher in the hospitalized group than in the nonhospitalized group. Graft and patient survivals were lower in the hospitalized group than in the nonhospitalized group. Deceased donor KT and acute rejection were independent risk factors for hospitalization.

CONCLUSION

The incidence of KTRs hospitalized within 1 year after KT was high. Most causes of hospitalization were CMV infection, acute rejection, and urinary tract infection. Therefore, the immunosuppression status of these patients should be closely monitored to reduce the hospitalization rate.

Progression of Osteoporosis After Kidney Transplantation in Patients With End-Stage Renal Disease

BACKGROUND

This study investigated the prevalence of osteoporosis and the risk factors for its progression in kidney transplant recipients (KTRs).

METHODS

Dual energy X-ray absorptiometry was used to prospectively measure changes in bone mineral density (BMD) before kidney transplantation (KT) and 1 year after transplantation in 207 individuals. We also analyzed the risk factors of osteoporosis progression during this period.

RESULTS

Prior to KT, the mean BMD score (T-score of the femur neck area) was -2.1 ± 1.2, and the prevalence of osteoporosis was 41.5% (86/207). At 1 year post-transplantation, the mean BMD score significantly decreased to -2.3 ± 1.1 (P < .001), and the prevalence of osteoporosis increased to 47.3% (98/207; P = .277). The BMD score worsened over the study period in 69.1% (143/207) of patients, improved in 24.1% (50/207), and showed no change in 6.8% (14/207). Minimal intact parathyroid hormone (iPTH) improvement after KT was found to be an independent risk factor of osteoporosis progression.

CONCLUSIONS

This study demonstrates progressive loss of BMD after KT and sustained secondary hyperparathyroidism might influence the progression of osteoporosis.

Kidney Transplantation in Korean Patients With End-Stage Renal Disease Aged 65 and Older: A Single-Center Experience

BACKGROUND

The mean age of patients starting dialysis in Korea has increased to older than 60 years and the proportion of patients aged 65 and older exceeded 40% in 2014. Although the number of elderly dialysis patients is increasing rapidly, percentages of elderly patients undergoing kidney transplantation (KT) are very low.

METHODS

We retrospectively reviewed the medical records of patients who underwent KT at Keimyung University Dongsan Medical Center between 1982 and 2016. Elderly patients (≥65 years old) were compared with the control group of patients in their early sixties (60-64 years old).

RESULTS

Among a total of 1209 KT patients, those in their early sixties totaled 34 (2.8%) and the elderly totaled only 18 (1.5%). Patient and allograft survival rate showed no significant differences between the elderly and those in their early sixties. Death with a functioning graft accounted for 50% in both groups. However, occurrences of bacterial infection and tuberculosis were higher in the elderly (P = .011 and .047, respectively). In a multivariate analysis, longer duration of renal replacement therapy before KT and the occurrence of malignancy were independent risk factors for patient death (hazard ratio [HR], 1.027; P = .014; HR, 31.934; P = .016, respectively). Also, albuminuria at 6 months after KT was an independent risk factor for allograft loss (HR, 51.155; P = .016).

CONCLUSION

The overall survival rate of the elderly was not significantly lower than those in their early sixties. Even in the elderly, KT should not be delayed. In addition, careful surveillance for malignancy and measures to decrease the risk of infection are necessary.

Long-term Clinical Outcomes of Kidney Re-transplantation

BACKGROUND

Kidney re-transplantation is commonly considered to have a higher immunological risk than first kidney transplantation. Because of the organ shortage and increasing waiting lists, long-term outcomes of kidney re-transplantation are being studied. However, reports of re-transplantation outcomes are not common. We have reported our 30 years of experience with second kidney transplantations.

METHODS

Of 1210 kidney transplantations between November 1982 and August 2016 performed in our hospital, 105 were second kidney transplantations (2nd KT). Living donor KT was 44; deceased donor KT was 61.

RESULTS

Patient survival rates at 1, 5, and 10 years were 100%, 97.2%, and 90.7%, and graft survival rates were 97.0%, 94.6%, and 71.5%, respectively. The leading cause of graft failure in the 2nd KT was chronic rejection (60%). In addition, induction immunosuppressant, maintenance immunosuppressant, delayed graft function, and graft survival time at the 1st KT had a significant impact on graft survival time at the 2nd KT.

CONCLUSIONS

Reasonable results in both patient survival and graft survival rates were found in the 2nd KT. Careful monitoring of immunologic risk is needed.

Effects of dietary alpha-tocopherol, selenium, and their different combinations on growth performance and meat quality of broiler chickens

This study investigated the effect of different levels of dietary supplementation with alpha-tocopherol or Se, or both, on growth performance and meat quality of broiler chickens. A total of 270 broiler chickens were assigned to 6 dietary treatments (0, 50, 100, or 200 IU of supplemental alpha-tocopherol; 0.3 ppm supplemental Se; or 100 IU of alpha-tocopherol plus 0.3 ppm Se) with 3 replicates of 15 chickens per pen. Growth performance was recorded at 1 and 35 d. At the end of this experiment, 10 broilers per pen were slaughtered, and thigh muscle was dissected from each carcass and stored at 4 degrees C for 1, 3, 7, and 10 d. During the experimental period, none of the experimental treatments significantly influenced the growth performance of broilers. Thigh muscle pH values of all treatments decreased over time. The pH values for 1, 3, and 10 d were not affected by all treatments, but a statistical difference among treatments was observed at 7 d. Thiobarbituric acid reactive substances and total plate counts in all treatments increased with increasing storage time. In TBA reactive substances values, there were significant differences (P < 0.05) among treatments during the storage period. Differences among treatments in total plate count were found at d 7 and 10. In all treatments, L* (lightness) and b* (yellowness) values decreased over time, and a* (redness) values increased with storage time. Significant differences in all treatments were found for L* values at 3 d and a* values at 7 and 10 d of storage. Overall, these data indicate that compared with other treatments, supplementation with 200 IU of alpha-tocopherol or 100 IU of alpha-tocopherol plus 0.3 ppm Se were most effective in increasing lipid oxidative stability and delaying microbial growth and these activities were not associated with pH.

The effect of gamma-irradiation on the viability of Cryptosporidium parvum

Cryptosporidium parvum is 1 of the major causative organisms in waterborne diarrheal illness. Not only does C. parvum spread ubiquitously in our environment, it is also highly resistant to harsh environmental conditions and disinfectants. Therefore, a control measure for this protozoon is urgently required. This study investigated the effect of gamma-irradiation, in the range of 1,000-50,000 Gy, on the viability of C. parvum oocysts. Oocyst viability was determined by a combined indirect immunofluorescence and nucleic acid staining and animal infectivity study. The proportion of viable oocysts estimated by nucleic acid staining ranged from 94.2 to 89.4% in the 0- to 10,000-Gy groups, whereas it was reduced significantly to 58.6 or 45.7% in the 25,000- or 50,000-Gy group, respectively, at 24 hr postirradiation. In an animal infectivity study, oocysts irradiated with less than 10,000 Gy induced infections in mice wherein there were low numbers of oocysts per gram of feces amounting to 8-10.8% of the values in control mice, whereas with 50,000 Gy-irradiated oocysts, no oocysts were produced in the mice. This study suggests that at least 50,000 Gy of gamma-irradiation is necessary for the complete elimination of oocyst infectivity in mice.

Cytokine balance in the lungs of patients with acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) involves an intense inflammatory response in the lungs, with accumulation of both pro- and antiinflammatory cytokines in bronchoalveolar lavage fluid (BALF). Our goal was to determine how the balance between pro- and antiinflammatory mediators in the lungs changes before and after the onset of ARDS. We identified 23 patients at risk for ARDS and 46 with established ARDS and performed serial bronchoalveolar lavage (BAL). We used immunoassays to measure tumor necrosis factor alpha (TNF-alpha) and soluble TNF-alpha receptors I and II; interleukin 1 beta (IL-1 beta), IL-1 beta receptor antagonist, and soluble IL-1 receptor II; IL-6 and soluble IL-6 receptor; and IL-10. We used sensitive bioassays to measure net TNF-alpha, IL-1 beta, and IL-6 activity. Although individual cytokines increased before and after onset of ARDS, greater increases occurred in cognate receptors and/or antagonists, so that molar ratios of agonists/antagonists declined dramatically at the onset of ARDS. The molar ratios remained low for 7 d or longer, limiting the activity of soluble IL-1 beta and TNF-alpha in the lungs at the onset of ARDS. This significant antiinflammatory response early in ARDS may provide a key mechanism for limiting the net inflammatory response in the lungs.

Effect of epidural anesthesia and analgesia on perioperative outcome: a randomized, controlled Veterans Affairs cooperative study

OBJECTIVE

To test the hypothesis that epidural anesthesia and postoperative epidural analgesia decrease the incidence of death and major complications during and after four types of intraabdominal surgical procedures.

SUMMARY BACKGROUND DATA

Even though many beneficial aspects of epidural anesthesia have been reported, clinical trials of epidural anesthesia for outcome of surgical patients have shown conflicting results.

METHODS

The authors studied 1,021 patients who required anesthesia for one of the intraabdominal aortic, gastric, biliary, or colon operations. They were assigned randomly to receive either general anesthesia and postoperative analgesia with parenteral opioids (group 1) or epidural plus light general anesthesia and postoperative epidural morphine (group 2). The patients were monitored for death and major complications during and for 30 days after surgery, as well as for postoperative pain, time of ambulation, and length of hospital stay.

RESULTS

Overall, there was no significant difference in the incidence of death and major complications between the two groups. For abdominal aortic surgical patients, unlike the other three types of surgical patients, the overall incidence of death and major complications was significantly lower in group 2 patients (22%) than in group 1 patients (37%), stemming from differences in the incidence of new myocardial infarction, stroke, and respiratory failure between the two groups. Overall, group 2 patients received significantly less analgesic medication but had better pain relief than group 1 patients. In group 2 aortic patients, endotracheal intubation time was 13 hours shorter and surgical intensive care stay was 3.5 hours shorter.

CONCLUSIONS

The effect of anesthetic and postoperative analgesic techniques on perioperative outcome varies with the type of operation performed. Overall, epidural analgesia provides better postoperative pain relief. Epidural anesthesia and epidural analgesia improve the overall outcome and shorten the intubation time and intensive care stay in patients undergoing abdominal aortic operations.

Gene profile of replicative senescence is different from progeria or elderly donor

In vitro cellular senescence of human diploid fibroblast has been a good model for aging research, which shows similar phenotypes to in vivo aging. Gene expression profiling would provide an insight to understand the mechanism of senescence. Using cDNA microarray containing 384 known genes, we compared the expression profiles of three different types of aging models: replicative senescence, fibroblasts from progeria or from elderly donor. Although all of them showed senescence phenotypes, distinct sets of genes were altered in each group. Pairwise plots or cluster analysis of activation fold of gene expression revealed closer relationships between fibroblasts from progeria or from old individual, but not between replicative senescence fibroblasts and either models. Differential expression pattern of several genes were confirmed by RT-PCR. We suggest that the replicative senescence model might behave differently to other types of aging models due to the distinct gene expression.

Uteroglobin gene polymorphisms affect the progression of immunoglobulin A nephropathy by modulating the level of uteroglobin expression

Uteroglobin (UG) is an anti-inflammatory/immunomodulatory protein. Targeted disruption of UG rendered mouse glomerulonephritis resembling immunoglobulin (Ig)A nephropathy (IgAN). Sequence analysis on exon 1 of UG showed several putative binding sites for transcription factors, and polymorphisms in this site might influence the expression level of UG as a competitive protein. We speculated that the single nucleotide polymorphism at the 38th nucleotide (A to G) from the transcription initiation site of UG exon 1 would impact the progression of IgA nephropathy (IgAN). Polymerase chain reaction-restriction fragment length polymorphism and single-strand conformation polymorphism were instituted to determine the genetic polymorphism. Luciferase assay was performed using the gene constructs containing a region 404-bp long located upstream of UG exon 1 initiation site to analyse whether this polymorphism would affect the expression level. UG polymorphism was distributed no differently in patients with IgAN (n = 111) compared to 60 healthy control subjects. An excess of A genotype was found in one patient having progressive disease (P = 0.03) and the risk for the disease progression increased as the number of A alleles increased (P for trend = 0.03) after follow-up for 116 months. The odds ratio for progression with the AA genotype was 4.9 (95% Cl = 1.0-23.9) compared to patients having the GG genotype. Significant interactive effects of hypertension and genetic polymorphisms of UG on the disease progression were observed (P for interaction = 0.001). In the luciferase assay, the gene construct with A at the 38th site showed a decreased activity of 74 +/- 8.4% compared to that showed by G gene construct. Our results suggest that polymorphism at the 5' UTR region of UG exon 1 is an important marker for the progression of IgAN and may modulate the level of protein expression.

[Application of DNA chip technology to biomedical research]

The completion of Human Genome Project enabled us to access to the information on nucleotide sequences of whole human genome. One of the most valuable information on human genome would be the list of approximately 35,000 genes. Although 35% of them are still needed to annotate their functions, we can genome-widely approach to various conditions including disease states. To analyze bunch of information at once, we need high-throughput technology containing most of genes. DNA chip successfully provide a stable platform technology for the massive screening of genomes. Microarrays can be used to obtain genome-wide fingerprint on transcriptional changes in various physiological and pathological conditions, leading to the mining novel genes related to those specific states. We can check the multiple molecular markers for diagnosis, prediction or prognosis of specific diseases. Data from microarray will provide huge amounts of experssion profile, which might induce the transformation of biomedical research.

Attenuation of EGF signaling in senescent cells by caveolin

One of the characteristics of senescent cells is unresponsiveness to external stimuli like EGF. Although they have a normal level of receptors and downstream signaling molecules, EGF cannot induce the activation of Erk kinases and DNA synthesis in senescent cells as much as in young cells. Caveolin proteins directly interact with signaling molecules including EGF receptor and suppress the activation of EGFR upon EGF stimulation. We found that Erk activation after EGF stimulation in senescent human diploid fibroblasts was down-regulated. Those senescent cells showed an increased level of three isoforms of caveolin proteins. This change seems to lie in transcriptional control in senescent cells. We also demonstrated up-regulated caveolin proteins were co-localized with EGFR proteins in detergent-insoluble fractions. From these results, we suggest that the up-regulated expression of caveolin might explain the unresponsiveness of senescent fibroblasts to EGF stimulation.

Effect of pentoxifylline on radiation response of non-small cell lung cancer: a phase III randomized multicenter trial

PURPOSES

The objectives of this prospective clinical trial were to determine whether pentoxifylline improves the radiation response and survival in patients with non-small cell lung cancer.

MATERIALS AND METHODS

From July 1993 through October 1994, 64 patients with histologically confirmed Stage I, II and III non-small cell lung cancer were randomly divided into pentoxifylline (Pento)+Radiotherapy (RT) group and RT alone group. Out of the 64 patients, only 47 patients who had measurable tumors on chest X-ray views were analyzed and divided into Pento+RT group (n=27) and RT alone group (n=20). Total tumor dose of 65-70 Gy was delivered as conventional fractionated radiation schedules. Pento was given to the patients 3 x 400 mg/day with a daily dose of 1200 mg during RT.

RESULTS

Complete response (CR), partial response (PR), and stable in Pento+RT group were three (11%), 13 (48%), and 11 (41%), respectively, as compared with corresponding values of three (15%), 13 (65%), and four (20%) in the RT alone group. The median time to relapse in the Pento+RT group was 11 months which was 2 months longer than for the RT alone group (P>0.05). All the patients in both groups showed lower than or equal to grade 2 dysphagia, odynophagia, pulmonary fibrosis, and pneumonitis. The median survival was 18 months in the Pento+RT group and 7 months in the RT alone group. The 1-year survival rate was 60% in the Pento+RT group and 35% in the RT alone group, the 2-year survival rate was 18% in the Pento+RT group and 12% in the RT alone group. But these differences were not statistically significant (P>0.05).

CONCLUSION

We concluded that Pento is a modestly effective radiation response modifier and provide benefit in the treatment of non-small cell lung cancer.

Senescence-like changes induced by hydroxyurea in human diploid fibroblasts

Hydroxyurea was found to inhibit the growth of human diploid fibroblasts, which resulted in senescence-like changes both in morphology and replicative potential similar to the replicative senescence. SA-beta-gal activity, a typical characteristic of the replicative senescence was also induced through a long-term treatment of the presenescent cells with 400-800 microgM of hydroxyurea for about 3 weeks. In addition, we determined the levels of cyclin-dependent kinase inhibitors, p21(Waf1) and p16(INK4a), and the p53 tumor suppressor in order to monitor its effect on cell cycle and stress responses. We observed a great induction of both p53 and p21(Waf1), but not of p16(INK4a) in the premature senescent cells. UV-irradiation of the premature senescent cells showed a decreased level of DNA fragmentation presumably ascribed to the reduced activation of stress-activated protein kinases. These results suggest that a chronic hydroxyurea treatment induces the cellular senescence in association with the induction of p53 and p21(Waf1).

Up-regulation of caveolin attenuates epidermal growth factor signaling in senescent cells

Senescent human diploid fibroblasts do not respond to growth factors like epidermal growth factor (EGF), although they have a normal level of receptors and downstream signaling molecules. To examine the mechanism of signaling attenuation, we investigated Erk activation after EGF stimulation in senescent cells. Senescent cells did not phosphorylate Erk-1/2 after EGF stimulation, whereas young cells did. In those senescent cells, we found an increased level of caveolin proteins and strong interactions between caveolin-1 and EGF receptor. Electron microscopic analysis demonstrated an increased number of caveolae structures in senescent cells. More interestingly, brain, spleen, and lung from 26-month-old rats showed substantial increases of caveolin proteins. However, in the case of p53-induced senescence, caveolin-1 was not induced, and EGF stimulation phosphorylated Erk-1/2 as much as young control cells. Finally, we overexpressed caveolin-1 in young human diploid fibroblasts in which the activation of Erk-1/2 upon EGF stimulation was significantly suppressed. These results suggest that the unresponsiveness of senescent fibroblasts to EGF stimulation may be due to the overexpression of caveolins, which seems to be independent of growth arrest and other aging phenotypes.

The cytoplasmic Purkinje onconeural antigen cdr2 down-regulates c-Myc function: implications for neuronal and tumor cell survival

Paraneoplastic cerebellar degeneration (PCD) is a disorder in which breast or ovarian tumors express an onconeural antigen termed cdr2, which normally is expressed in cerebellar Purkinje neurons. This leads to an immune response to cdr2 that is associated with tumor immunity and autoimmune cerebellar degeneration. We have found that cdr2, a cytoplasmic protein harboring a helix-leucine zipper (HLZ) motif, interacts specifically with the HLZ motif of c-Myc. Both proteins colocalize in the cytoplasm of adult cerebellar Purkinje neurons, and coimmunoprecipitate from tumor cell lines and cerebellar extracts. cdr2 down-regulates c-Myc-dependent transcription in cotransfection assays, and redistributes Myc protein in the cytoplasm. Disease antisera from six of six PCD patients specifically blocked the interaction between cdr2 and c-Myc in vitro. These data indicate that cdr2 normally sequesters c-Myc in the neuronal cytoplasm, thereby down-regulating c-Myc activity, and suggest a mechanism whereby inhibition of cdr2 function by autoantibodies in PCD may contribute to Purkinje neuronal death.

Formaldehyde treatment suppresses ruminal degradation of phytate in soyabean meal and rapeseed meal

Most of the P in oilseed meal is in the form of phytate P, and phytate forms complexes with protein. Phytate P has been considered to be absorbed easily in ruminants because of phytate degradation in the rumen. Treatment of oilseed meals with formaldehyde improves the nutritional value of protein through suppressing its ruminal degradation. The present experiment was conducted to study the effects of formaldehyde treatment on phytate degradation in the rumen. The ruminal degradation of phytate in formaldehyde-treated soyabean meal or rapeseed meal was determined by a nylon-bag technique in sheep. Soyabean meal and rapeseed meal were treated with formaldehyde at levels of 3, 5 or 10 g/kg. Treatment with formaldehyde suppressed phytate and protein degradation in both the oilseed meals. Compared with the regular soyabean meal, the regular rapeseed meal showed lower degradability of phytate in the rumen. These results suggest that treatment with formaldehyde suppresses ruminal degradation of phytate in oilseed meal. Thus, the absorption of P from oilseed meal is probably decreased by this treatment in ruminants.

Suppression of ceramide-mediated apoptosis by HSP70

Ceramide has been known as an important second messenger in programmed cell death (apoptosis) which is induced by various stimuli such as the tumor necrosis factor-alpha (TNF-alpha), Fas ligand, and environmental stresses such as UV-irradiation and heat shock. Although the precise molecular mechanism of apoptosis is not fully understood, ceramide generated by sphingomyelinase (SMase) mediates the activation of several downstream molecules that are implicated in the regulation of apoptosis. Here, we show that stress-inducible heat shock protein 70 (Hsp70) prevents apoptosis induced by increased level of intracellular ceramide. In T-cell hybridoma DO11.10, we examined the effect of Hsp70 on apoptosis mediated by TNF-alpha, Fas ligation, SMase, and C2-ceramide, all of which elevate intracellular ceramide levels. Hsp70 not only markedly reduced internucleosomal DNA fragmentation, but also enhanced cell viability measured by the Trypan blue dye exclusion test. Similarly, the ceramide-induced c-jun amino-terminal kinase (JNK/SAPK) activation is impaired in cells overexpressing Hsp70. These data strongly suggest that hsp70 functions as a regulator of apoptosis downstream of ceramide.

Expression of heat shock protein 70 blocks thymic differentiation of T cells in transgenic mice

Heat shock protein 70 (HSP70) is involved not only in protein folding, but also in processes of differentiation and cell-cycle progression. Recently, HSP70 has been implicated in mediation of functions of some immunosuppressive agents. To study the role of HSP70 in differentiation of haematopoietic cells, we generated transgenic mice using the human inducible hsp70 gene fused to the mouse H-2K promoter. These mice develop a T-cell deficiency that is characterized by thymic hypoplasia and a significant reduction in peripheral T cells. The total number of thymocytes is about 100-fold less than that in normal mice. The majority of the thymocytes are immature T cells that express neither CD4 nor CD8 molecules, indicating that T cells are affected at an early stage of thymic differentiation. Expression of the transgenic HSP70 was detected both in bone marrow cells and in thymocytes. Furthermore, injection of normal bone marrow cells into the T-cell deficient mice led to the generation of mature T cells indicating that the T-cell deficiency was caused by the action of HSP70 in T cells. The blockage of differentiation occurred only in T cells, both alphabeta- and gammadelta-T-cell receptor (TCR)-bearing cells, but not in B cells, granulocytes, and monocytes. The observations suggest that HSP70 may inhibit a cellular process that is essential for the differentiation of early stage T cells. Further experiments using this model system will widen our understanding of HSP70 and its function on a molecular level.

FGF-10 is a chemotactic factor for distal epithelial buds during lung development

Fibroblast growth factor (FGF) signaling is required for normal epithelial branching in the respiratory system of several species. Recent studies have shown that FGF-10 may be a key regulator of lung branching morphogenesis, based on its pattern of expression in the early lung and its ability to induce epithelial budding in vitro. In this study we investigate whether FGF-10 is able to direct lung epithelial buds to proper positions during development . We maintained localized high levels of FGF-10 in cultured lungs using FGF-10-soaked heparin beads. FGF-10 exerts a powerful chemoattractant effect on the distal but not on proximal lung epithelium. Epithelial buds grow toward an FGF-10 source within 24 h, and subsequently form concentric layers of epithelium around the bead. BrdU incorporation analysis suggests that FGF-10, in contrast to FGF-7, is a modest proliferation factor for the lung epithelium. In the absence of mesenchyme FGF-10 requires an associated proliferative signal to induce bud migration. This can be provided by extract from lung mesenchyme, or by FGF-7, a growth factor also present in the early embryonic lung. FGF-10 does not seem to interfere with early epithelial cell differentiation. The chemoattractant effect of FGF-10 in the lung epithelium is reminiscent of the patterning effect of the Drosophila FGF ortholog branchless in the developing tracheal epithelium, suggesting that the function of these genes has been conserved during evolution.

The role of inducible 70-kDa heat shock protein in cell cycle control, differentiation, and apoptotic cell death of the human myeloid leukemic HL-60 cells

Several studies have suggested a role for heat shock proteins (hsps) during development and differentiation. However, relatively little is known about the role of hsp70 in controlling human hematopoietic cell differentiation and death. Here, we show that constitutive expression of human inducible 70-kDa heat shock protein (hsp70) promotes differentiation of HL-60 cells and prevents apoptosis that occurred after terminal differentiation or directly by apoptotic agents. After treatment with phorbol 12-myristate 13-acetate (PMA), hsp70-overexpressing cells (HL-60/hsp70) underwent rapid growth arrest and plastic adherence and expressed more CD14 than parental HL-60 or empty vector-transformed cells (HL-60/puro). HL-60/hsp70 cells also rapidly differentiated into granulocytes by addition of all-trans-retinoic acid, as assessed by phenotypic changes after staining with Wright-Giemsa. After differentiation into monocyte/macrophage-like cells or granulocytes, hsp70-overexpressing cells showed little evidence for apoptosis and had a prolonged survival, indicating that the survival-enhancing properties of hsp70 counteract programmed cell death that accompanies terminal differentiation. HL-60/hsp70 cells also showed more resistance than parental cells against apoptotic agents such as sodium nitroprusside, a NO-generating agent, or Taxol, a microtubule stabilizing agent. Further, heat shock of parental HL-60 cells at 42 degrees C for 3 h increased hsp70 levels, promoted plastic adherence (< 6 h) of the cells in respond to PMA, and protected cells from SNP or Taxol. Taken together, these studies demonstrate that hsp70 plays a crucial role in the differentiation of myeloid cells, participating in cell cycle controls and phenotypic changes, with protecting effects on apoptosis induced by different pathways.

c-Fes tyrosine kinase binds to and activates STAT3 after granulocyte-macrophage colony-stimulating factor stimulation

Granulocyte-macrophage colony stimulating factor (GM-CSF) induces proliferation and maturation of myeloid progenitor cells and also activates neutrophils. In order to investigate the pleiotropic effects of GM-CSF stimulation, we examined the signaling pathways of protein tyrosine kinases (PTKs) and signal transducers and activators of transcription (STATs) in GM-CSF-dependent proliferation of leukemia cells. Using TF-1, a GM-CSF-dependent human erythroleukemia cell line, we found that GM-CSF enhanced DNA-binding and tyrosine phosphorylation of STAT3. GM-CSF receptor (GM-CSFR) and c-Fes tyrosine kinase were also activated upon GM-CSF stimulation. Furthermore, c-Fes formed a complex with STAT3. Experiments using a c-Fes mutant that lacked tyrosine kinase activity revealed that the activation of STAT3 is kinase-dependent, but that the c-Fes-STAT3 interaction is not affected by c-Fes tyrosine kinase activity. The results suggest that STAT3 is activated by c-Fes tyrosine kinase through direct interaction during hematopoietic cell proliferation induced by GM-CSF.

Thymic epithelial tumor progression in an SV40T transgenic mouse model. Cortical thymoma-thymic carcinoma sequence

There have been several reports that thymoma in human is a progressive disease, and that thymoma and thymic carcinoma form a continuum. We established a stable line of SV40T transgenic mice, which consistently produced thymic epithelial tumours progressing to thymic carcinoma within a predictable time span. Using this animal model and a morphological approach, thymic epithelial tumour progression was studied with reference to sequential changes at different time points in animals aged from 3 to 32 weeks. At all ages, SV40T was expressed in the nuclei of thymic epithelial cells; in these transgenic mice we observed the entire spectrum from cortical type thymoma to thymic carcinoma. Thymic size tended to increase with ageing in SV40T TG mice. While younger mice had predominantly cortical (organoid) or cortical thymoma, older mice had well-differentiated thymic carcinoma (WDTC) or poorly differentiated thymic carcinoma. When SV40T TG mice (248 line) reached a certain age, carcinoma of the thymus was present in all of them. Cortical-type thymoma became malignant within a predictable time span, suggesting a cortical thymoma-carcinoma sequence. When the mice were 9 weeks of age, the thymuses formed gross masses compatible with cortical thymoma. At 14 weeks of age, WDTC appeared against the background of cortical thymoma. Poorly differentiated thymic carcinoma was found after 15 weeks and affected all animals over 23 weeks of age. Most thymic carcinomas coexisted in varying proportions with cortical-type thymoma. Medullary thymomas did not develop in the mice, and no transition from medullary-type thymomas to thymic carcinomas was observed. In this SV40T transgenic mouse model, thymic carcinoma is clearly preceded by cortical-type thymoma. These transgenic mice may provide an interesting model for the progression from cortical thymoma to WDTC and/or high-grade carcinoma.

Development of thymic carcinoma in transgenic mice expressing SV40 T antigen

We produced transgenic mice using SV40 Tag gene under the control of its own enhancer and promoter. Three transgenic lines (SNU-SVT125, 127, 248) consistently developed thymic carcinoma as well as choroid plexus carcinoma and dysplastic renal tubule. In SNU-SVT248 line, SV40 Tag transgene was expressed at thymus, spleen and kidney. Thymic epithelium showed high level expression of SV40 Tag in immunohistochemistry. Histopathological and electron microscopic analysis revealed that poorly differentiated carcinoma was derived from type 2 to 4 thymic epithelial cell. Our transgenic mice would provide a model for studies on the pathogenesis of thymic carcinoma and on the regulation of thymopoiesis by epithelial cells.

Leucine zipper-like domain regulates the autophosphorylation and the transforming activity of P130gag-fps

P130gag-fps, the product of Fujinami sarcoma virus, has a leucine zipper (LZ) motif located in 729-756 amino acid residues. To explore the role of LZ-like domain in the transformation by P130gag-fps, we made a deletion (delta FpsLZ/SH2) and a site-directed substitution mutation (L746P). Deletion mutant did not transform the 3Y1 cells and the resulting protein did not show kinase activity. Substitution of Leu746 with Pro (L746P) reduced the transforming activity by 6-fold. Although the L746P mutant retained intact catalytic activity in vitro, it did not phosphorylate cellular proteins in vivo. We concluded that LZ-like domain might mediate the trans-activation of P130gag-fps tyrosine kinase by autophosphorylation, which is prerequisite for the transforming activity.

Patient-controlled sedation during epidural anesthesia

The purpose of this study was to evaluate the feasibility and advantages or disadvantages, if any, of patient-controlled sedation compared with sedation administered by the anesthesiologist during surgical epidural anesthesia. Forty patients were divided at random into two groups with 20 patients in each group. Patients in group 1 received 0.5-1.0 mg intravenous midazolam and 25-50 micrograms intravenous fentanyl in increments administered by the anesthesiologist to achieve intraoperative sedation; patients in group 2 self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 micrograms) in increments using an Abbott Lifecare PCA infuser to achieve sedation. Demographics of the patients, the types of surgery performed, doses of midazolam and fentanyl administered in a given period of time, and the level of sedation maintained during epidural anesthesia and surgery were similar in both groups. Patients in the self-administered group, however, rated their level of comfort during anesthesia and surgery higher than did those in the anesthesiologist-controlled sedation group. This could have been due to a positive psychological effect produced by allowing patient to feel that they have some control over their situation. The findings of this study indicate that patient-controlled sedation using a combination of midazolam and fentanyl is a safe and effective technique that provides intraoperative sedation ranked better by patients than that provided by anesthesiologists using the same drugs. More studies are, however, needed to determine the best choice of drug(s), the doses, the lock-out intervals, and the possible use of continuous infusion with patient-controlled sedation.

Epidural anesthesia in patients undergoing thoracic surgery

Epidural anesthesia has been reported to exert beneficial effects in surgical procedures. Over the past 3 years at the Veterans Administration Medical Center in Washington, DC, thoracic surgical procedures have been done using a combined technique of epidural anesthesia with light general anesthesia. A retrospective review of this experience from January 1984 to November 1987 was done in 90 consecutive patients. Postoperative extubation of patients was accomplished immediately in 32%, within 1 hour in 34%, within 3 hours in 28%, within 18 hours in 4%, and was prolonged in only 1% of patients. Mortality was 2% and morbidity was 3%. This analysis indicates that the technique of epidural anesthesia with light general anesthesia provided satisfactory anesthesia with low mortality and morbidity in a high-risk group of patients undergoing surgery.

Incidence and cardiac effects of systemic venous air embolism. Echocardiographic evidence of arterial embolization via noncardiac shunt

Central nervous system dysfunction in venous air embolism may result from air entering the arterial circulation. Using two-dimensional and pulsed-wave Doppler echocardiography, this study not only documented the frequent presence of air in the right heart chambers of patients undergoing upright neurosurgery or pacemaker insertion, but also documented the presence of air in the left atrium and left ventricle of one patient via noncardiac shunt. Studies in dogs confirmed paradoxical air embolism in the absence of anatomic communications between right and left heart chambers. Systemic venous air also produced a dose-dependent increase in pulmonary artery pressure and diastolic flattening of the ventricular septum with increase in left ventricular filling pressure despite preserved systolic function.

Age and the spread of local anesthetic solutions in the epidural space

Sensory level of anesthesia following the injection of 20 ml of 1.5% lidocaine with epinephrine (1:200,000) in 238 adult males averaged T7.7, T5.6, and T5.1 at 10, 20, and 30 minutes, respectively. Patient age had no significant effect on local anesthetic requirements per spinal segment per unit height until age 40 years, which age the calculated amount of local anesthetic decreased significantly to 0.62 ml from 0.69 ml/segment/meter of height. Above age 40 there was no further decrease in epidural anesthetic requirement with advancing age. Patient height was inversely related to sensory level (p < 0.001). Time required for anesthesia ro recede to T12 averaged 164 minutes and was slightly but significantly (p < 0.05) prolonged with advancing age.

Effects of patient age, pH of cerebrospinal fluid, and vasopressors on onset and duration of spinal anesthesia

Two hundred twenty-two spinal anesthesias were administered with 10 mg. of tetracaine and 1 ml. of 10 percent dextrose to investigate the effects of vasopressors, patients age, and pH of cerebrospinal fluid on the onset and duration of spinal anesthesia. Neither the differences in overall age, cerebrospinal fluid pH, nor the addition of vasopressors had any significant effect on onset. Duration, however, was significantly prolonged by the addition of vasopressors, 53 percent prolongation by 0.2 mg. of epinephrine and 72 percent prolongation by 2 mg. of phenylephrine.