Exploring the Smoking-Epilepsy Nexus: a systematic review and meta-analysis of observational studies : Smoking and epilepsy

BACKGROUND

Epilepsy, characterized by recurrent unprovoked seizures, poses significant challenges to affected individuals globally. While several established risk factors for epilepsy exist, the association with cigarette smoking remains debated. This study aims to conduct systematic review and meta-analysis to elucidate the potential association between smoking and the likelihood of epilepsy.

METHODS

The search was performed on March 31st, 2023, using the Medline, Embase, Web of Science, Scopus, and ScienceDirect. We included cohort, cross-sectional, and case-control studies in our meta-analysis, conducting subgroup analyses based on smoking history, sex, and epilepsy type to yield specific insights.

RESULTS

We identified 2550 studies, of which 17 studies were finally included in this study. The pooled odds ratio of epilepsy was 1.14 (0.96-1.36) in smokers compared to non-smokers. In current smokers compared to non-smokers, the odds ratio was 1.46 (1.13-1.89), while, in former smokers compared to non-smokers, the odds ratio was 1.14 (0.83-1.56).

CONCLUSIONS

While the overall association between smoking and epilepsy did not reach statistical significance, a notable association was found among current smokers. The study emphasizes the importance of smoking cessation as a potential preventive measure against epilepsy, especially given the proconvulsive effects of nicotine. Future research should address limitations and explore specific clinical scenarios to enhance our understanding of the complex relationship between cigarette use and epilepsy.

SYSTEMATIC REVIEW REGISTRATION

CRD42022342510.

Association of smoking with amyotrophic lateral sclerosis: A systematic review, meta-analysis, and dose-response analysis

INTRODUCTION

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder primarily affecting the voluntary motor nervous system. Several observational studies have provided conflicting results regarding the association between smoking and ALS. Therefore, our objective was to investigate this association through a systematic review, meta-analysis, and dose-response analysis.

METHODS

On 16 January 2023, we initially extracted records from medical databases, which included Medline, Embase, Web of Science, Scopus, and ScienceDirect. We included case-control and cohort studies as eligible studies. Subgroup analyses were performed based on sex, study design, and current smoking. Restricted cubic-spline analysis was utilized to assess the dose-response relationship between smoking (pack-years) and ALS.

RESULTS

Twenty-eight case-control and four cohort studies met the inclusion criteria. The unadjusted OR for the overall association between smoking and ALS was 1.14 (95% CI: 1.06-1.22, I2=44%, p<0.001), and the adjusted OR (AOR) was 1.12 (95% CI: 1.03-1.21, I2=49%, p=0.009). Subgroup analysis revealed a more pronounced association among current smokers, with an AOR of 1.28 (95% CI: 1.10-1.49, I2=66%, p<0.001) and AOR of 1.28 (95% CI: 1.10-1.48, I2=58%, p=0.001). In the dose-response analysis, the non-linear model revealed an inverted U-shaped curve.

CONCLUSIONS

Our study provides evidence of a positive relationship between smoking and the risk of ALS. To mitigate the risk of developing ALS, discontinuing smoking, which is a modifiable risk factor, may be crucial.TRIAL REGISTRATION: The study was registered in PROSPERO.IDENTIFIER: CRD42023388822.

The Prognostic Significance of Leukocyte Count on All-Cause and Cardiovascular Disease Mortality: A Systematic Review and Meta-Analysis

White blood cells (WBCs) act as mediators of inflammatory responses and are commonly measured in hospitals. Although several studies have reported a relation between WBC count and mortality, no systematic review or meta-analysis has been conducted. This study aimed to identify an association between WBC count and mortality. We conducted a systematic search on Embase using keywords such as "white blood cell" and "mortality." We analyzed the hazard ratios (HRs) for WBC count of 1.0 × 109 cells/L regarding 2 criteria: the cause of mortality and the follow-up period. A total of 13 of 222 articles comprising a total of 62,904 participants were included in this study, meeting the criteria set. A positive association was observed between WBC count and mortality, as indicated by an HR of 1.10 (95% confidence interval [CI] 1.08 to 1.13). In additionally, WBC count emerged as a significant predictor of mortality in both groups, with an HR of 1.10 (95% CI 1.07 to 1.12) for patients with cardiovascular disease and an HR of 1.12 (95% CI 1.07 to 1.17) for the general population or patients with COVID-19. Furthermore, a higher WBC count demonstrated a significant association with long-term all-cause mortality (HR 1.09, 95% CI 1.07 to 1.12) and long-term cardiovascular mortality (HR 1.05, 95% CI 1.02 to 1.07). Similarly, a significant association was found between higher WBC count and short-term all-cause mortality (HR 1.12, 95% CI 1.09 to 1.16) and cardiovascular mortality (HR 1.12, 95% CI 1.07 to 1.17). Further research is necessary to explore the relation between WBC count and disease progression or death and to establish causality between elevated WBC count and disease progression.

Osteopontin is a key regulator of vascular smooth muscle cell proliferation in the outflow vein of arteriovenous fistulas

OBJECTIVES

Despite advances in the maintenance of arteriovenous fistulas (AVFs), the patency rates remain suboptimal. Most AVFs fail due to outflow vein stenosis; however, the underlying mechanism of AVF stenosis remains unclear. The present study aimed to identify key factors associated with AVF outflow stenosis.

METHODS

We obtained gene expression profiling data for the outflow vein of AVF from three Gene Expression Omnibus database datasets (GSE39488, GSE97377, and GSE116268) and analyzed the common differentially expressed genes (DEGs). We evaluated a common DEG in an aortocaval mouse model and the stenotic outflow veins of AVFs collected from patients. Furthermore, we isolated vascular smooth muscle cells (VSMCs) from the inferior vena cava (IVC) of wild-type (WT) and osteopontin (Opn)-knockout (KO) mice and assessed the proliferation of VSMCs following stimulation with platelet-derived growth factors (PDGFs).

RESULTS

OPN was the only common upregulated DEG among all datasets. OPN was expressed in the medial layer of the outflow vein of AVF in aortocaval mouse models and co-stained with the VSMC marker (α-smooth muscle actin). OPN expression was markedly increased in the VSMCs of stenotic outflow veins of AVF collected from patients undergoing hemodialysis compared to presurgical veins acquired during AVF formation surgery. PDGF-induced VSMC proliferation was significantly increased in the VSMCs isolated from the IVC of WT mice but not in those isolated from the IVC of Opn-KO mice.

CONCLUSIONS

OPN may be a key gene involved in VSMC proliferation in the AVF outflow veins and a therapeutic target to improve the AVF patency rate.

Role of PCK2 in the proliferation of vascular smooth muscle cells in neointimal hyperplasia

Vascular smooth muscle cell (VSMC) proliferation is a hallmark of neointimal hyperplasia (NIH) in atherosclerosis and restenosis post-balloon angioplasty and stent insertion. Although numerous cytotoxic and cytostatic therapeutics have been developed to reduce NIH, it is improbable that a multifactorial disease can be successfully treated by focusing on a preconceived hypothesis. We, therefore, aimed to identify key molecules involved in NIH via a hypothesis-free approach. We analyzed four datasets (GSE28829, GSE43292, GSE100927, and GSE120521), evaluated differentially expressed genes (DEGs) in wire-injured femoral arteries of mice, and determined their association with VSMC proliferation in vitro. Moreover, we performed RNA sequencing on platelet-derived growth factor (PDGF)-stimulated human VSMCs (hVSMCs) post-phosphoenolpyruvate carboxykinase 2 (PCK2) knockdown and investigated pathways associated with PCK2. Finally, we assessed NIH formation in Pck2 knockout (KO) mice by wire injury and identified PCK2 expression in human femoral artery atheroma. Among six DEGs, only PCK2 and RGS1 showed identical expression patterns between wire-injured femoral arteries of mice and gene expression datasets. PDGF-induced VSMC proliferation was attenuated when hVSMCs were transfected with PCK2 siRNA. RNA sequencing of PCK2 siRNA-treated hVSMCs revealed the involvement of the Akt-FoxO-PCK2 pathway in VSMC proliferation via Akt2, Akt3, FoxO1, and FoxO3. Additionally, NIH was attenuated in the wire-injured femoral artery of Pck2-KO mice and PCK2 was expressed in human femoral atheroma. PCK2 regulates VSMC proliferation in response to vascular injury via the Akt-FoxO-PCK2 pathway. Targeting PCK2, a downstream signaling mediator of VSMC proliferation, may be a novel therapeutic approach to modulate VSMC proliferation in atherosclerosis.

Association between surgeon age and postoperative complications/mortality: a systematic review and meta-analysis of cohort studies

The surgical workforce, like the rest of the population, is ageing. This has raised concerns about the association between the age of the surgeon and their surgical outcomes. We performed a systematic review and meta-analysis of cohort studies on postoperative mortality and major morbidity according to the surgeons' age. The search was performed on February 2021 using the Embase, Medline and CENTRAL databases. Postoperative mortality and major morbidity were evaluated as clinical outcomes. We categorized the surgeons' age into young-, middle-, and old-aged surgeons. We compared the differences in clinical outcomes for younger and older surgeons compared to middle-aged surgeons. Subgroup analyses were performed for major and minor surgery. Ten retrospective cohort studies on 29 various surgeries with 1,666,108 patients were considered. The mortality in patients undergoing surgery by old-aged surgeons was 1.14 (1.02-1.28, p = 0.02) (I² = 80%) compared to those by middle-aged surgeon. No significant differences were observed according to the surgeon's age in the major morbidity and subgroup analyses. This meta-analysis indicated that surgeries performed by old-aged surgeons had a higher risk of postoperative mortality than those by middle-aged surgeons. Thus, it necessitates the introduction of a multidisciplinary approach to evaluate the performance of senior surgeons.

Discrepancy between the Demand and Supply of Intensive Care Unit Beds in South Korea from 2011 to 2019: A Cross-Sectional Analysis

PURPOSE

Intensive care unit (ICU) bed availability is key to critical patient care. In many countries, older patients generally account for a significant proportion of hospitalizations and ICU admissions. Therefore, considering the rapidly increasing aging population in South Korea, it is important to establish whether the demand for critical care is currently met by available ICU beds.

MATERIALS AND METHODS

We evaluated a 9-year trend in ICU bed supply and ICU length of stay in South Korea between 2011 and 2019 in a population-based cross-sectional analysis, using data from the Korean Health Insurance Review & Assessment Service and Statistics database. We described the changes in ICU bed rates in adult (≥20 years) and older adult (≥65 years) populations. ICU length of stay was categorized similarly and was used to predict future ICU bed demands.

RESULTS

The ICU bed rate per 100000 adults increased from 18.5 in 2011 to 19.5 in 2019. In contrast, the ICU bed rate per 100000 older adults decreased from 127.6 in 2011 to 104.0 in 2019. ICU length of stay increased by 43.8% for adults and 55.6% for older adults. In 2019, the regional differences in the ICU bed rate nearly doubled, and the ICU length of stay increased six-fold. The ICU bed occupancy rate in South Korea is expected to rise to 102.7% in 2030.

CONCLUSION

The discrepancy between the demand and supply of ICU beds in South Korea requires urgent action to anticipate future ICU demands.

Neuropeptide Y: a potential theranostic biomarker for diabetic peripheral neuropathy in patients with type-2 diabetes

Background:

Diabetic peripheral neuropathy (DPN), the most common microvascular complication of type-2 diabetes mellitus (T2DM), results in nontraumatic lower-limb amputations. When DPN is not detected early, disease progression is irreversible. Thus, biomarkers for diagnosing DPN are needed.

Methods:

We analyzed three data sets of T2DM DPN: two for mouse models (GSE70852 and GSE34889) and one for a human model (GSE24290). We found common differentially expressed genes (DEGs) in the two mouse data sets and validated them in the human data set. To identify the phenotypic function of the DEGs, we overexpressed them in zebrafish embryos. Clinical information and serum samples of T2DM patients with and without DPN were obtained from the Korea Biobank Network. To assess the plausibility of DEGs as biomarkers of DPN, we performed an enzyme-linked immunosorbent assay.

Results:

Among the DEGs, only NPY and SLPI were validated in the human data set. As npy is conserved in zebrafish, its mRNA was injected into zebrafish embryos, and it was observed that the branches of the central nervous system became thicker and the number of dendritic branches increased. Baseline characteristics between T2DM patients with and without DPN did not differ, except for the sex ratio. The mean serum NPY level was higher in T2DM patients with DPN than in those without DPN (p = 0.0328), whereas serum SLPI levels did not differ (p = 0.9651).

Conclusion:

In the pathogenesis of DPN, NPY may play a protective role in the peripheral nervous system and may be useful as a biomarker for detecting T2DM DPN.

Reliability and Quality of YouTube Videos on Ultrasound-Guided Brachial Plexus Block: A Programmatical Review

BACKGROUND

Ultrasound-guided regional anesthesia has gained popularity over the last decade. This study aimed to assess whether YouTube videos sufficiently serve as an adjunctive tool for learning how to perform an ultrasound-guided brachial plexus block (BPB).

METHODS

All YouTube videos were classified, based on their sources, as either academic, manufacturer, educational, or individual videos. The metrics, accuracy, utility, reliability (using the Journal of American Medical Association Score benchmark criteria (JAMAS)), and educational quality (using the Global Quality Score (GQS) and Brachial Plexus Block Specific Quality Score (BSQS)) were validated.

RESULTS

Here, 175 videos were included. Academic (1.19 ± 0.62, mean ± standard deviation), manufacturer (1.17 ± 0.71), and educational videos (1.15 ± 0.76) had better JAMAS accuracy and reliability than individual videos (0.26 ± 0.67) (p < 0.001). Manufacturer (11.22 ± 1.63) and educational videos (10.33 ± 3.34) had a higher BSQS than individual videos (7.32 ± 4.20) (p < 0.001). All sources weakly addressed the equipment preparation and post-procedure questions after BSQS analysis.

CONCLUSIONS

The reliability and quality of ultrasound-guided BPB videos differ depending on their source. As YouTube is a useful educational platform for learners and teachers, global societies of regional anesthesiologists should set a standard for videos.

Molecular insights into the development of hepatic metastases in colorectal cancer: a metastasis prediction study

OBJECTIVE

Colorectal cancer is presently the third most commonly diagnosed cancer in the United States. In this study, we identified molecular differences between hepatic and non-hepatic metastases in colorectal cancer and evaluated their prognostic significance.

MATERIALS AND METHODS

We downloaded primary data from the NCBI Gene Expression Omnibus (GSE6988, GSE62321, GSE50760, and GSE28722). To identify the molecular differences, we used the Significance Analysis of Microarray method. We selected nine prognostic genes (SYTL2, PTPLAD1, CDS1, RNF138, PIGR, WDR78, MYO7B, TSPAN3, and ATP5F1) with hepatic metastasis prediction score in colorectal cancer (hereafter referred to as LASSO Score). We confirmed the prognostic significance of the LASSO Score by using Kaplan-Meier survival analysis, multivariate analysis, the time-dependent area under the curve (AUC) of Uno's C-index, and the AUC of the receiver operating characteristic curve at 1-5 years.

RESULTS

Survival analysis revealed that a high LASSO Score is associated with a poor prognosis in colorectal cancer patients with hepatic metastases (p = 0). Analysis of C-indices and AUC values from the receiver operating characteristic curve further supported this prediction by the LASSO Score. Multivariate analysis confirmed the prognostic significance of the LASSO Score (p = 1.13e-06).

CONCLUSIONS

This study reveals the biological mechanisms underlying hepatic metastases in colorectal cancer and will help in developing targeted therapies for colorectal cancer.

Prognostic Significance of COVID-19 Receptor ACE2 and Recommendation for Antihypertensive Drug in Renal Cell Carcinoma

PURPOSE

Owing to its worldwide spread, the coronavirus disease (COVID-19) epidemic was declared a pandemic by the World Health Organization on March 11, 2020. Angiotensin-converting enzyme 2 (ACE2) is the outer surface protein of the cell membrane that is abundantly distributed in the heart, lungs, and kidneys and plays an important role in molecular docking of the severe acute respiratory syndrome coronavirus 2. In this study, we aimed to analyze the difference in the survival rate according to ACE2 expressions in pan-cancer.

MATERIALS AND METHODS

We downloaded clinical and genomic data from The Cancer Genome Atlas. We used Kaplan-Meier with a log-rank test, and the Cox proportional hazards regression to analyze prognostic significance.

RESULTS

In the Kaplan-Meier curve, clear cell renal cell carcinoma (ccRCC), uveal melanoma, and prostate adenocarcinoma showed statistical significance. In the Cox regression, thyroid carcinoma and glioblastoma multiforme and ccRCC showed significant results. Only ccRCC had statistical significance, and high ACE2 expression is related to good prognosis. It is known that the ACE inhibitor, a primary antihypertensive agent, increases ACE2 expression.

CONCLUSION

Based on these results, we believe that the ACE inhibitor will be important to increase the lifespan of ccRCC patients. This study is the first research to offer a recommendation on the use of anti-hypertensive drugs to ccRCC patients.

LRRC17 Is Linked to Prognosis of Ovarian Cancer Through a p53-dependent Anti-apoptotic Function

BACKGROUND/AIM

Since pathways involving LRRC17 are related to the survival of patients with various cancers, we analyzed LRRC17 as a prognostic gene in serous ovarian cancer.

MATERIALS AND METHODS

Data were collected from Gene Expression Omnibus (GSE9891, GSE13876, and GSE26712) and The Cancer Genome Atlas (TCGA). We performed survival analyses using C statistics, area under the curve, survival plot with optimal cutoff level, and cox proportional regression. Zebrafish embryos were used as an in vivo model.

RESULTS

The prognosis of patients with high LRRC17 expression was poorer than that of patients with low LRRC17 expression. Multivariate regression analysis showed that LRRC17 expression, age, and stage were independently related with survival. Knockdown of lrrc17 reduced survival rate and delayed development in zebrafish embryos. We also found that lrrc17 is important for cell viability by protecting from p53-dependent apoptosis.

CONCLUSION

LRRC17 could be a prognostic gene in ovarian cancer as it regulates cancer cell viability through the p53 pathway.

Prognostic role of high cathepsin D expression in breast cancer: a systematic review and meta-analysis

Background:

High cathepsin D has been associated with poor prognosis in breast cancer; however, the results of many studies are controversial. Here, we assessed the association between high cathepsin D levels and worse breast cancer prognosis by conducting a meta-analysis.

Methods:

A comprehensive search strategy was used to search relevant literature in PUBMED and EMBASE by September 2018. The meta-analysis was performed in Review Manager 5.3 using hazard ratios (HRs) with 95% confidence intervals (CIs).

Results:

A total of 15,355 breast cancer patients from 26 eligible studies were included in this meta-analysis. Significant associations between elevated high cathepsin D and poor overall survival (OS) (HR = 1.61, 95% CI: 1.35–1.92, p < 0.0001) and disease-free survival (DFS) (HR = 1.52, 95% CI: 1.31–2.18, p < 0.001) were observed. In the subgroup analysis for DFS, high cathepsin D was significantly associated with poor prognosis in node-positive patients (HR = 1.38, 95% CI: 1.25–1.71, p < 0.00001), node-negative patients (HR = 1.78, 95% CI: 1.39–2.27, p < 0.0001), early stage patients (HR = 1.73, 95% CI: 1.34–2.23, p < 0.0001), and treated with chemotherapy patients (HR = 1.60, 95% CI: 1.21–2.12, p < 0.001). Interestingly, patients treated with tamoxifen had a low risk of relapse when their cathepsin D levels were high (HR = 0.71, 95% CI: 0.52–0.98, p = 0.04) and a high risk of relapse when their cathepsin D levels were low (HR = 1.50, 95% CI: 1.22–1.85, p = 0.0001).

Conclusions:

Our meta-analysis suggests that high expression levels of cathepsin D are associated with a poor prognosis in breast cancer. Based on our subgroup analysis, we believe that cathepsin D can act as a marker for poor breast cancer prognosis and also as a therapeutic target for breast cancer.

Altered physiology of mesenchymal stem cells in the pathogenesis of adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis is the most common spinal deformity during puberty, especially in females. It is characterized by aberrant skeletal growth and generalized reduced bone density, which is associated with impaired bone mineral metabolism. Despite recent progress in multidisciplinary research to support various hypotheses, the pathogenesis of Adolescent idiopathic scoliosis is still not clearly understood. One of the hypothesis is to study the role of mesenchymal stem cells due to its involvement in the above-mentioned bone metabolic abnormalities. In this review, we will summarize reported literatures on the role of mesenchymal stem cells, particularly in the pathogenesis of Adolescent idiopathic scoliosis. In addition, we will describe the research on mesenchymal stem cells of Adolescent idiopathic scoliosis performed using bioinformatics tools.

Comparison of Outcomes of Hybrid and Surgical Correction for De Novo Arteriovenous Graft Occlusion

Purpose

This study aimed to compare surgical revisions and balloon angioplasty after surgical thrombectomy on thrombosed dialysis access as a first event.

Materials and Methods

Records of patients undergoing creation of arteriovenous grafts (AVGs) at the Gachon University Gil Medical Center between March 2008 and February 2016 were reviewed. Among them, patients who underwent treatment on first-time thrombotic occlusion after AVG creation were identified. Outcomes were primary, primary-assisted, and secondary patency. The patency was generated using the Kaplan-Meier method, and patency rates were compared by log-rank test.

Results

A total of 59 de novo interventions (n=26, hybrid interventions; n=33, surgical revisions) for occlusive AVGs were identified. The estimated 1-year primary patency rates were 47% and 30% in the surgery and hybrid groups, respectively. The estimated primary patency rates were not different between the two groups (log-rank test, P=0.73). The Kaplan-Meier estimates of 6 and 12 months for primary-assisted patency rates were 68% and 57% in the surgery group and 56% and 56% in the hybrid group. The Kaplan-Meier estimates of 12 and 24 months secondary patency rates were 90% and 71% in the surgery group and 79% and 62% in the hybrid group. There were no differences in the estimated primary-assisted and secondary patency rates between the two groups.

Conclusion

Our results showed no significant difference between the two groups in terms of primary patency (P=0.73), primary-assisted patency (P=0.85), and secondary patency (P=0.78). However, percutaneous transluminal angioplasty can give more therapeutic options for both surgeons and patients.

Early onset adenovirus infection after simultaneous kidney-pancreas transplant

Adenoviruses (AdV) are increasingly recognized as important viral pathogens in immunocompromised hosts. The clinical spectrum ranges from asymptomatic viremia to allograft dysfunction, and death. Most of the medical literature is on AdV infection in children and bone marrow transplant recipients. We report a case of AdV in an adult recipient in the first month after simultaneous kidney-pancreas transplant with thymoglobulin induction. This is a rare report of adenovirus infection after multiorgan transplant, and is unique in that it exhibited tissue invasive disease without any localizing signs or allograft dysfunction, while other cases in medical literature had invasive disease of the allograft with allograft dysfunction, failure, or death. In addition, this is the first report of a radiologic presentation of AdV nephritis.

Quantitative PCR for the measurement of circulating proviral load in HIV-infected individuals

BACKGROUND

PCR has been applied extensively as a tool for the detection of HIV. We have previously developed a semi-quantitative microtiter plate assay for the specific detection of HIV PCR products.

OBJECTIVE

To develop and evaluate a novel quantitative assay for the measurement of circulating proviral load in HIV-infected individuals.

STUDY DESIGN

We evaluated 70 consecutive, unselected HIV-infected patients, divided into 3 groups, according to their CD4 cell count: greater than 500 cells/microl (10 subjects); 200-500 cells/microl (31 subjects); less than 200 cells/microl (29 subjects). Peripheral blood mononuclear cell lysates were amplified, and a portion of the product was added to streptavidin-coated wells with a biotinylated capture probe and a horseradish peroxidase-linked reporter probe, complementary to separate regions of the amplified product. Following incubation, readings were taken with an automated plate reader. Products were quantitated by interpolation into a standard curve of serial dilutions of an HIV-containing plasmid, included in each assay.

RESULTS

HIV sequences were detected in all 70 clinical samples. Within each patient category, a wide range of proviral loads were observed. However, proviral load/10(6) CD4 cells was associated with disease progression when the patient groups were considered (up to 9.6% infected cells in subjects with CD4 cell counts below 200/microl).

CONCLUSIONS

This quantitative PCR assay will allow the measurement of proviral load in clinical samples. It may be useful in the managment of HIV-infected individuals and the evaluation of the efficacy of antiretroviral therapy.

Association of natural killer cell depletion with induction of mixed chimerism and allograft tolerance in non-human primates

BACKGROUND

Nonmyeloablative T cell depletion followed by donor bone marrow infusion has proved to be an effective approach to induction of mixed chimerism and tolerance of organ allografts in non-human primates. To help define the mechanisms involved we have compared T cell depletion with ATG versus anti-CD2 monoclonal antibody with respect to establishment of mixed chimerism and induction of tolerance.

METHOD

Both nonmyeloablative regimens included low dose total body irradiation (1.5 Gy x 2), thymic irradiation (7 Gy), splenectomy and kidney plus donor bone marrow transplantation, followed by a 4-week posttransplant course of cyclosporine. In addition, the ATG group (13 recipients) received antithymocyte globulin, although the LOCD2b group (10 recipients) were treated with an anti-CD2 monoclonal antibody (LOCD2b).

RESULTS

In the ATG group, 11 of 13 monkeys developed multilineage chimerism and 9 survived for more than 100 days without kidney allograft rejection. In contrast, 0/10 monkeys in the LOCD2b group developed chimerism, 5 died of infection and 5 suffered progressive rejection; only 1 recipient survived beyond 100 days. Sequential monitoring of peripheral blood mononuclear cells revealed greater T cell (CD3+) depletion in the LOCD2b-treated animals compared to those receiving ATG. However, NK cells (CD16+CD8+) were significantly more depleted in the ATG group and NK function remained abrogated longer after ATG than LOCD2b treatment (3 weeks vs. <5 days).

CONCLUSION

Despite excellent T cell depletion by LoCD2b, ATG was more effective in inducing chimerism and tolerance. This difference correlated with anti-NK activity of the two reagents. These data suggest that NK cells may also resist engraftment of allogeneic bone marrow cells in this model.

Long-term outcome and alloantibody production in a non-myeloablative regimen for induction of renal allograft tolerance

BACKGROUND

Multilineage chimerism and long-term acceptance of renal allografts has been produced in non-human primates conditioned with a nonmyeloablative regimen. Our study was undertaken to evaluate the immunological and pathological status of long-term survivors and to define the role of splenectomy and of the primarily vascularized kidney in the regimen.

METHOD

Monkeys were treated with the basic regimen, including: total body irradiation, thymic irradiation, antithymocyte globulin, donor bone marrow transplantation, and a 4-week course of cyclosporine after which no further immunosuppression was given. They were divided into four groups according to the timing of kidney transplantation (KTx) and splenectomy as follows; group A (n=13): KTx and splenectomy on the day of donor bone marrow transplantation (day 0); group B (n=3): KTx on day 0 without splenectomy; group C (n=7): splenectomy on day 0 but delayed KTx until 3 to 16 weeks post-donor bone marrow transplantation; group D (n=3): both splenectomy and KTx delayed until day 120 post-donor bone marrow transplantation.

RESULTS

In group A, 11 of 13 monkeys developed chimerism and 9 monkeys achieved long-term survival of 4 to 70 months without evidence of chronic vascular rejection. Alloantibodies were detected in only one long-term survivor. In contrast, all three monkeys in group B developed alloantibodies and rejected their allografts. In group C, long-term survival without alloantibody production was observed in two of three monkeys that had developed chimerism. In group D, all three recipients were sensitized and rejected the kidney allografts rapidly after transplantation.

CONCLUSIONS

1) Production of anti-donor antibody was prevented in most recipients that developed mixed chimerism in the regimens with splenectomy at the time of donor bone marrow transplantation. 2) If splenectomy is not included in the initial conditioning regimen, induction of B cell tolerance is less likely and the result is late onset of alloantibody production and allograft rejection. 3) Immediate transplantation of the kidney at the time of recipient conditioning is not essential for induction of donor specific hyporesponsiveness by bone marrow transplantation.

The clinical usefulness of the renal allograft biopsy in the cyclosporine era: a prospective study

BACKGROUND

The renal allograft biopsy is generally accepted as the gold standard for clarifying the cause of renal dysfunction. However, the clinical usefulness of this procedure has rarely been studied prospectively, nor have most studies included follow-up of patients to delineate the influence of the biopsy on clinical outcome. In this study, we evaluated prospectively the clinical usefulness of the allograft biopsy in renal transplant recipients receiving cyclosporine (CyA).

METHODS

During a 21-month period, 82 biopsies were performed. In 54 instances (47 patients), we outlined a presumed diagnosis and tentative treatment plan before the procedure. After the biopsy, a definitive diagnosis was made and an appropriate patient management approach was instituted. We analyzed the incidence of change in patient management that resulted from histological findings. All patients were followed to monitor their response to treatment and allograft survival. In cases of biopsy-proven acute cellular rejection (ACR) or cyclosporine (CyA) toxicity, clinical and laboratory data from the day of the biopsy were reviewed to determine their diagnostic value.

RESULTS

One biopsy specimen was inadequate for definitive interpretation. The biopsy findings resulted in a change in patient management in 22 (41.5%) of the remaining 53 cases (change group). The incidence of altered patient management was 38.7% in biopsy specimens taken in the first month, 55.6% between 1 and 12 months, and 38.5% after 1 year posttransplantation. A change in management was required in 2 of 2 patients with chronic allograft dysfunction, in 44.4% of the 45 patients with acute allograft dysfunction, and in none of the patients with delayed graft function (n=6). Within the first week of treatment 19 of 22 (86.4%) in the change group and 25 of 31 (80.6%) in the no change group had a positive response to therapy. The 1-year allograft survival rate was also similar between the two groups. None of the clinical and laboratory data was useful in distinguishing ACR from CyA toxicity.

CONCLUSIONS

Renal allograft biopsy findings alter patient management recommendations in approximately 40% of patients in whom a presumptive diagnosis had been made on the basis of clinical and laboratory findings. Patients who had a change in patient management because of biopsy findings demonstrated a response to therapy and allograft survival similar to those of patients who had no alteration in management plan after the biopsy.

Demonstration of multilineage chimerism in a nonhuman primate concordant xenograft model

Prior studies from our laboratory have demonstrated that a nonmyeloablative conditioning regimen can induce transient mixed chimerism and renal allograft tolerance between MHC disparate cynomolgus monkeys. We have also shown that this preparative regimen can be extended to a concordant baboon to cynomolgus xenograft model by adding, to the post transplant protocol, therapy designed to prevent antibody production. Here we examine the use of brequinar (BQR) for this purpose and the efficacy of two new reagents developed to demonstrate the establishment of chimerism in the xenograft recipients. The cynomolgus recipients were conditioned with WBI (300 cGy), TI (700 cGy), ATG, cyclosporine, and brequinar sodium. To detect engraftment of the donor marrow, we prepared a polyclonal cynomolgus anti-baboon antibody (CABA) and a monoclonal antibody (215.1), which distinguish baboon and cynomolgus lymphocytes and granulocytes. We employed flow cytometry analysis to detect multilineage chimerism in the xenograft recipients. Five of the six recipients monitored using our new reagents (CABA and 215.1) developed detectable chimerism and only one of these animals lost its kidney to rejection. However, other complications have not permitted assessment of long-term outcome. The features of the multilineage chimerism included the detection of donor granulocytes (1.8-77.4%) and lymphocytes (2.4-22.2%) for 9 to 37 days. Our new reagents permit the detection of multilineage mixed chimerism, which may be a predictor of xenograft tolerance. We also conclude that brequinar may be effective in preventing antibody formation, but because of its toxicity, it is probably not the drug of choice for extension of the mixed chimerism protocol to concordant xenografts.

An evaluation of quality of life in patients with continent urinary diversions after cystectomy

OBJECTIVE

To determine the long-term results and assess the quality of life in patients with continent urinary diversions after cystectomy.

PATIENTS AND METHODS

Eighty-six consecutive patients who received a continent urinary diversion from 1988 to 1994 at the Vancouver Hospital and Health Sciences Center were evaluated. The evaluation comprised a review of their hospital charts and clinic visits at 3 months and then yearly. Quality of life issues were assessed using a postal questionnaire pertaining to the patient's urinary symptoms. activity level and overall well-being while living with a continent urinary diversion. Two separate questionnaires were sent, addressing heterotopic or orthotopic diversions.

RESULTS

There was an acceptable rate of complications, with stone formation and urinary tract infection as the most common morbidities. Continence was rated as good in most patients, with no patient reporting complete incontinence. Undesirable urinary symptoms occurred less often than 20% of the time in most patients. Although there was a significant effect on sex life, the overall quality of life appeared to be very good, as 70% of the patients had no limitations to their activities.

CONCLUSIONS

The techniques currently evolved for urinary diversion produce good long-term results and quality of life. These diversions should be considered in a well selected patient population.

Effective treatment of lymphedema of the extremities

OBJECTIVE

To define the immediate and long-term volumetric reduction following complete decongestive physiotherapy (CDP) for lymphedema.

DESIGN

Prospective study of consecutively treated patients.

SETTING

Freestanding outpatient referral centers.

PATIENTS

Two hundred ninety-nine patients referred for evaluation of lymphedema of the upper (2% primary, 98% secondary) or lower (61.3% primary, 38.7% secondary) extremities were treated with CDP for an average duration of 15.7 days. Lymphedema reduction was measured following completion of treatment and at 6- and 12-month follow-up visits.

INTERVENTION

Complete decongestive physiotherapy is a 2-phase noninvasive therapeutic regimen. The first phase consists of manual lymphatic massage, multilayered inelastic compression bandaging, remedial exercises, and meticulous skin care. Phase 2 focuses on self-care by means of daytime elastic sleeve or stocking compression, nocturnal wrapping, and continued exercises.

MAIN OUTCOME MEASURES

Average limb volumes in milliliters were calculated prior to treatment, at the end of phase 1, and at 6- to 12-month intervals during phase 2 to assess percent volume reduction.

RESULTS

Lymphedema reduction averaged 59.1% after upper-extremity CDP and 67.7% after lower-extremity treatment. With an average follow-up of 9 months, this improvement was maintained in compliant patients (86%) at 90% of the initial reduction for upper extremities and lower extremities. Noncompliant patients lost a part (33%) of their initial reduction. The incidence of infections decreased from 1.10 infections per patient per year to 0.65 infections per patient per year after a complete course of CDP.

CONCLUSIONS

Complete decongestive physiotherapy is a highly effective treatment for both primary and secondary lymphedema. The initial reductions in volume achieved are maintained in the majority of the treated patients. These patients typically report a significant recovery from their previous cosmetic and functional impairments, and also from the psychosocial limitations they experienced from a physical stigma they felt was often trivialized by the medical and payor communities.

Multiple-transducer scheme for scanning tomographic acoustic microscopy using transverse waves

We propose a new type of multiple-transducer scheme with functions of multiple-angle and multiple-frequency tomography for scanning tomographic acoustic microscopy (STAM) using transverse waves. We review the data acquisition system and mode conversion of the acoustic waves for STAM and the multiple-angle and multiple-frequency tomography. Our multiple-transducer scheme has three insonification angles and three resonance frequencies in order to operate, in the transverse wave mode, multiple-angle and multiple frequency tomography for STAM. In order to evaluate the performance of our transducer scheme, we have simulated tomographic reconstruction with a back-and-forth propagation algorithm. Simulation results show that our multiple-transducer scheme is capable of obtaining good resolution with transverse wave mode and multiple-frequency tomography. We also show that our multiple-transducer scheme is an efficient rotation tool for a number of projections.

The correlation of multichannel urodynamic pressure-flow studies and American Urological Association symptom index in the evaluation of benign prostatic hyperplasia

PURPOSE

We correlated multichannel pressure-flow urodynamics and the American Urological Association (AUA) symptom index in the evaluation of benign prostatic hyperplasia.

MATERIALS AND METHODS

We evaluated 121 consecutive, symptomatic patients older than 55 years with the AUA symptom score and multichannel pressure-flow urodynamic studies. Testing was performed during a single session and the data obtained from 103 patients were plotted on the Schäfer nomogram for assessment of outflow obstruction. Linear regression statistical analysis was used to determine correlations.

RESULTS

There was no significant correlation between uroflowmetry and Schäfer curves (r = 0.173 to 0.326), uroflowmetry and AUA symptom scores (r = 0.134 to 0.153) and, most importantly, AUA symptom scores and Schäfer curves (r = 0.025 to 0.137).

CONCLUSIONS

We conclude that these modalities measure independent variables, and should not be linked in the evaluation and treatment decision of the patient with prostatism.

Venovenous bypass in renal cell carcinoma with caval tumor thrombus

We describe two patients with a T3bN2M0 renal cell carcinoma with caval extension to the hepatic veins in which we successfully utilized extracorporeal femoralaxillary venovenous bypass for tumor thrombus resection. The inherent advantage of this modified venovenous bypass are discussed with a current review of the literature.

Influence of vesicle size, lipid composition, and drug-to-lipid ratio on the biological activity of liposomal doxorubicin in mice

The effects of vesicle size, lipid composition, and drug-to-lipid ratio on the biological activity of liposomal doxorubicin in mice have been investigated using a versatile procedure for encapsulating doxorubicin inside liposomes. In this procedure, vesicles exhibiting transmembrane pH gradients (acidic inside) were employed to achieve drug trapping efficiencies in excess of 98%. Drug-to-lipid ratios as high as 0.3:1 (wt:wt) could be obtained in a manner that is relatively independent of lipid composition and vesicle size. Egg phosphatidylcholine (EPC)/cholesterol (55:45; mol/mol) vesicles sized through filters with a 200-nm pore size and loaded employing transmembrane pH gradients to achieve a doxorubicin-to-lipid ratio of 0.3:1 (wt/wt) increased the LD50 of free drug by approximately twofold. Removing cholesterol or decreasing the drug-to-lipid ratio in EPC/cholesterol preparations led to significant decreases in the LD50 of liposomal doxorubicin whereas, the LD50 increased 4- to 6-fold when distearoylphosphatidylcholine was substituted for EPC. The results suggest that the stability of liposomally entrapped doxorubicin in the circulation is an important factor in the toxicity of this drug in liposomal form. In contrast, the antitumor activity of liposomal doxorubicin is not influenced dramatically by alterations in lipid composition. Liposomal doxorubicin preparations of EPC, EPC/cholesterol (55:45; mol:mol), EPC/egg phosphatidylglycerol (EPG)/cholesterol (27.5:27.5:45; mol:mol), and distearoylphosphatidylcholine/cholesterol (55:45; mol:mol) all demonstrated similar efficacy to that of free drug when given at doses of 20 mg/kg and below. Higher dose levels of the less toxic formulations could be administered, leading to enhanced increases in life span (ILS) values. Variations in vesicle size, however, strongly influenced the antitumor activity of liposomal doxorubicin. At a dose of 20 mg/kg, large EPC/cholesterol systems are significantly less effective than free drug (with ILS values of 65% and 145%, respectively). In contrast, small systems sized through filters with a 100-nm pore size are more effective than free drug, resulting in an ILS of 375% and a 30% long term (greater than 60 days) survival rate when administered at a dose of 20 mg/kg. Similar size-dependent effects are observed for distearoylphosphatidylcholine/cholesterol systems.

Toward an in vitro system for picornavirus assembly: purification of mengovirus 14S capsid precursor particles

Mengovirus 14S subviral protein particles generated in infected L cells and in a cell-free translation system primed with mengovirus RNA were purified by sucrose gradient centrifugation and immunoaffinity chromatography. The preparations from both sources contained essentially pure proteins epsilon, alpha, and gamma, as was demonstrated in terms of virus-specific proteins (by autoradiography) and total protein content (by silver staining of sodium dodecyl sulfate-polyacrylamide electrophoresis gels). These purified proteins sedimented as discrete particles at the 14S position when recentrifuged in sucrose gradients. Although their assembly properties have not yet been studied in detail, preliminary results indicate that during incubation with virion RNA the 14S particles purified from infected cells can form a structure cosedimenting with mature mengovirus.