"Everyone screens to some extent": Barriers and facilitators of developmental screening among children with sickle cell disease: A mixed methods study

BACKGROUND

Developmental delays are common among children with sickle cell disease (SCD). Existing guidelines support consistent screening to increase the identification of deficits and support referral to rehabilitative interventions, yet adherence remains variable. This study sought to assess current practices and identify barriers and facilitators to improve developmental screening for children 0-3 years with SCD.

PROCEDURE

A mixed methods approach, guided by the Exploration and Preparation stages of the Exploration, Preparation, Implementation, and Sustainment (EPIS) framework, assessed developmental screening practices among primary care providers and hematologists. Phase 1 included the SCD Developmental Surveillance and Screening Guideline and Practice Survey. Phase 2 included the SCD Developmental Screening Organizational Survey alongside semi-structured interviews. Descriptive and qualitative methods summarized the findings.

RESULTS

Thirty-three providers from general pediatrics and hematology completed phase 1. Use of standardized developmental screening measures was variable, with the most frequently used being the Modified Checklist for Autism in Toddlers (77%) and the Ages and Stages Questionnaire (55%). Fifteen providers participated in phase 2, and reported they were most likely to engage in changes to improve their practice (mean = 4.4/5) and least likely to support spiritual health and well-being (mean = 3.5/5). Three themes emerged:(i) developmental screening is not standardized or specific to SCD, (ii) children with SCD benefit from a multidisciplinary team, and (iii) healthcare system limitations are a barrier.

CONCLUSIONS

Developmental screening is inconsistent and insufficient for young children with SCD. Providers are interested in supporting children with SCD, but report a lack of standardized measures and consistent guidance as barriers.

Impact of the COVID-19 pandemic in childhood and adolescent cancer care in northern Tanzania: a cross-sectional study

INTRODUCTION

The SARS-CoV-2 (COVID-19) pandemic has strained healthcare systems and presented unique challenges for children requiring cancer care, particularly in low- and middle-income countries. This study aimed to assess the impact of the COVID-19 pandemic on access to cancer care for children and adolescents in Northern Tanzania.

METHODS

In this cross-sectional study, we assessed the demographic and clinical characteristics of 547 pediatric and adolescent cancer patients (ages 0-19 years old) between 2016 and 2022 using the population-based Kilimanjaro Cancer Registry (KCR). We categorized data into pre-COVID-19 (2016-2019) and COVID-19 (2020-2022) eras, and performed descriptive analyses of diagnostic, treatment, and demographic information. A secondary analysis was conducted on a subset of 167 patients with stage of diagnosis at presentation.

RESULTS

Overall admissions nearly doubled during the pandemic (n = 190 versus 357). The variety of diagnoses attended at KCMC increased during the pandemic, with only five groups of diseases reported in 2016 to twelve groups of diseases in 2021. Most patients were diagnosed at a late stage (stage III or IV) across eras, with the proportion of under-five years old patients increasing late-diagnoses from 29.4% (before the pandemic), 52.8% (during the pandemic), when compared to the overall cohort. Around 95% of children in this age category reported late-stage diagnosis during the pandemic. Six out of the twelve cancer site groups also reported an increase in late-stage diagnosis. During the pandemic, the proportion of children receiving surgery increased from 15.8 to 30.8% (p < 0.001).

CONCLUSION

Childhood and adolescent cancer care changed in Northern Tanzania during the COVID-19 pandemic, with increased late-stage diagnoses presentations among younger patients and the increased use of surgical therapies in the context of a growing practice. Understanding the impact of the COVID-19 pandemic on pediatric and adolescent cancer care can help us better adapt healthcare systems and interventions to the emerging needs of children and adolescents with cancer in the midst of a health crisis.

Improved accuracy and efficiency of primary care fall risk screening of older adults using a machine learning approach

BACKGROUND

While many falls are preventable, they remain a leading cause of injury and death in older adults. Primary care clinics largely rely on screening questionnaires to identify people at risk of falls. Limitations of standard fall risk screening questionnaires include suboptimal accuracy, missing data, and non-standard formats, which hinder early identification of risk and prevention of fall injury. We used machine learning methods to develop and evaluate electronic health record (EHR)-based tools to identify older adults at risk of fall-related injuries in a primary care population and compared this approach to standard fall screening questionnaires.

METHODS

Using patient-level clinical data from an integrated healthcare system consisting of 16-member institutions, we conducted a case-control study to develop and evaluate prediction models for fall-related injuries in older adults. Questionnaire-derived prediction with three questions from a commonly used fall risk screening tool was evaluated. We then developed four temporal machine learning models using routinely available longitudinal EHR data to predict the future risk of fall injury. We also developed a fall injury-prevention clinical decision support (CDS) implementation prototype to link preventative interventions to patient-specific fall injury risk factors.

RESULTS

Questionnaire-based risk screening achieved area under the receiver operating characteristic curve (AUC) up to 0.59 with 23% to 33% similarity for each pair of three fall injury screening questions. EHR-based machine learning risk screening showed significantly improved performance (best AUROC = 0.76), with similar prediction performance between 6-month and one-year prediction models.

CONCLUSIONS

The current method of questionnaire-based fall risk screening of older adults is suboptimal with redundant items, inadequate precision, and no linkage to prevention. A machine learning fall injury prediction method can accurately predict risk with superior sensitivity while freeing up clinical time for initiating personalized fall prevention interventions. The developed algorithm and data science pipeline can impact routine primary care fall prevention practice.

Financial burden of men with localized prostate cancer: a process paper

Background

Many individuals undergoing cancer treatment experience substantial financial hardship, often referred to as financial toxicity (FT). Those undergoing prostate cancer treatment may experience FT and its impact can exacerbate disparate health outcomes. Localized prostate cancer treatment options include: radiation, surgery, and/or active surveillance. Quality of life tradeoffs and costs differ between treatment options. In this project, our aim was to quantify direct healthcare costs to support patients and clinicians as they discuss prostate cancer treatment options. We provide the transparent steps to estimate healthcare costs associated with treatment for localized prostate cancer among the privately insured population using a large claims dataset.

Methods

To quantify the costs associated with their prostate cancer treatment, we used data from the Truven Health Analytics MarketScan Commercial Claims and Encounters, including MarketScan Medicaid, and peer reviewed literature. Strategies to estimate costs included: (1) identifying the problem, (2) engaging a multidisciplinary team, (3) reviewing the literature and identifying the database, (4) identifying outcomes, (5) defining the cohort, and (6) designing the analytic plan. The costs consist of patient, clinician, and system/facility costs, at 1-year, 3-years, and 5-years following diagnosis.

Results

We outline our specific strategies to estimate costs, including: defining complex research questions, defining the study population, defining initial prostate cancer treatment, linking facility and provider level related costs, and developing a shared understanding of definitions on our research team.

Discussion and next steps

Analyses are underway. We plan to include these costs in a prostate cancer patient decision aid alongside other clinical tradeoffs.

Delays in cancer care for children in low-income and middle-income countries: development of a composite vulnerability index

BACKGROUND

Early access to diagnosis and care is essential to improve rates of survival from childhood cancer, particularly in low-income and middle-income countries (LMICs). Composite indices are increasingly used to compare country performance in many health fields. We aimed to develop a composite vulnerability index of risk of mortality associated with delays in care for childhood cancer in LMICs, and to compare the vulnerability index scores across countries.

METHODS

The composite vulnerability index was built in ten steps. A previous systematic review of determinants of delays in cancer care for children guided data selection. We collected exposure variables (determinants of delays in care) and outcome variables (childhood cancer-related mortality) from several large datasets. Data were analysed with regression models to identify determinants of delays in care that contribute to childhood cancer mortality. Significant indicators were aggregated into domains according to the socio-ecological model. We used geospatial tools to summarise and compare the composite vulnerability index scores across countries.

FINDINGS

We found that life expectancy, maternal education, fertility rate, availability of pathology services, bone marrow transplantation capacity, availability of treatment services (chemotherapy, radiotherapy, or surgery), number of pharmacists per 10 000 population, country income level, and out-of-pocket health expenditure were significantly associated with cancer mortality for children in LMICs. The highest levels of vulnerability were found in sub-Saharan Africa.

INTERPRETATION

Our composite vulnerability index can potentially serve as a valuable policy decision tool to help monitor country performance and guide interventions to reduce delays in care for children with cancer in LMICs.

FUNDING

None.

TRANSLATIONS

For the Chinese, Portuguese, Arabic, Spanish and Swahili translations of the abstract see Supplementary Materials section.

Immune expression in children with Wilms tumor: a pilot study

BACKGROUND

Given improvements in multimodality therapy, survival among children with Wilms tumor (WT) exceeds 90%. However, 15% of children with favorable histology and 50% of children with anaplastic WT experience recurrence or progression. Of patients with advanced disease, only 50% survive to adulthood. In adult malignancies (including renal tumors), patient survival has improved with the advent of immunotherapy. However, little is known about the immune microenvironment of WT, making the potential role of immunotherapy unclear.

OBJECTIVE

The objective of the study is to perform an exploratory, descriptive analysis of the immune milieu in WT.

STUDY DESIGN

Between 2016 and 2017, all pediatric patients with WT, some of whom received neoadjuvant chemotherapy, underwent ex vivo wedge biopsy at the time of nephrectomy. The fresh tumor tissue and peripheral blood samples were analyzed for infiltrating immune infiltrate and effector cells using flow cytometry. Immunohistochemistry was performed for CD4, CD8, and PD-L1 expression. Matched blood samples were obtained for each patient, and circulating immune cells were analyzed by flow cytometry.

RESULTS

A total of six patients were enrolled. One patient with neuroblastoma was excluded. The remaining five patients included the following: two with unilateral WT (resected before chemotherapy), two with bilateral WT (resected after neoadjuvant chemotherapy), and one with Denys-Drash syndrome, end-stage renal disease, and history of WT in the contralateral kidney. Immune analysis showed that WT were infiltrated by immune cells regardless of chemotherapy status. CD8 and CD4 T cells were present in the tumor tissue and exhibited an activated phenotype. Elevated levels of natural killer (NK) cells were observed in the tumors (Figure). Immune checkpoint PD-L1 was also found expressed in one of the tumors stained.

DISCUSSION

In this pilot study, it was found that WTs were infiltrated by immune cells (CD45+) both before and after chemotherapy. Elevated levels of NK cells infiltrating the tumor specimens, which were quantitatively increased compared with levels of NK cells circulating in the blood, were noted. T cells, particularly CD4+ and CD8+ T cells, were present in tumor specimens. Tumor-infiltrating CD4 and CD8 T cells displayed an activated phenotype as defined by increased expression of human leukocyte antigen-DR isotype (HLA-DR), programmed cell death protein 1 (PD1), and CD57. Together, these findings suggest that WT microenvironment is immune engaged and may be susceptible to immunotherapy similar to other malignancies.

CONCLUSIONS

These pilot data suggest an immune-engaged tumor microenvironment is present within WT. This implies that WT may be susceptible to immunotherapy similar to adult renal tumors and other adult malignancies. Follow-up studies are currently underway.

Congenital diaphragmatic hernia: a systematic review and summary of best-evidence practice strategies

OBJECTIVES

Recent reports suggest that specific care strategies improve survival of infants with congenital diaphragmatic hernia (CDH). This review presents details of care from centers reporting high rates of survival among CDH infants.

STUDY DESIGN

We conducted a MEDLINE search (1995 to 2006) and searched all citations in the Cochrane Central Register of Controlled Trials. Studies were included if they contained reports of >20 infants with symptomatic CDH, and >75% survival of isolated CDH.

RESULT

Thirteen reports from 11 centers met inclusion criteria. Overall survival, including infants with multiple anomalies, was 603/763 (79%; range: 69 to 93%). Survival for isolated CDH was 560/661 (85%; range: 78 to 96%). The frequency of extracorporeal membrane oxygenation (ECMO) use for isolated CDH varied widely among reporting centers 251/622 (40%; range: 11 to 61%), as did survival for infants with isolated CDH placed on ECMO: 149/206 (73%; range: 33 to 86%). There was no suggestion of benefit from use of antenatal glucocorticoids given after 34 weeks gestation or use of postnatal surfactant. Low mortality was frequently attributed to minimizing lung injury and adhering to center-specific criteria for ECMO.

CONCLUSION

Use of strategies aimed at minimizing lung injury, tolerance of postductal acidosis and hypoxemia, and adhering to center-specific criteria for ECMO were strategies most consistently reported by successful centers. The literature lacks randomized clinical trials of these or other care strategies in this complex patient population; prospective studies of safety and long-term outcome are needed.

Characterization of neuronal/glial differentiation of murine adipose-derived adult stromal cells

Neural tissue has limited capacity for intrinsic repair after injury, and the identification of alternate sources of neuronal stem cells has broad clinical potential. Preliminary studies have demonstrated that adipose-derived adult stromal (ADAS) cells are capable of differentiating into mesenchymal and non-mesenchymal cells in vitro, including cells with select characteristics of neuronal/glial tissue. In this study, we extended these observations to test the hypothesis that murine (mu) ADAS cells can be induced to exhibit characteristics of neuronal and glial tissue by exposure to a cocktail of induction agents. We characterized the differentiation of muADAS cells in vitro using immunohistochemistry and immunoblotting, and examined whether these cells respond to the glutamate agonist N-methyl-D-aspartate (NMDA). We found that induced muADAS cells express proteins indicative of neuronal/glial cells, including nestin, GFAP, S-100, NeuN, MAP2, tau, and beta-III tubulin. Induced muADAS cells express gamma-aminobutyric acid (GABA), the NR-1 and NR-2 subunits of the glutamate receptor, GAP-43, synapsin I, and voltage-gated calcium channels. Finally, induced muADAS cells demonstrate decreased viability in response to NMDA. These findings suggest that muADAS cells can be induced to exhibit several phenotypic, morphologic, and excitotoxic characteristics consistent with developing neuronal and glial tissue.

Results of a pilot trial comparing prolonged intravenous antibiotics with sequential intravenous/oral antibiotics for children with perforated appendicitis

HYPOTHESIS

For children with perforated appendicitis, the use of a prolonged course of intravenous (i.v.) antibiotics is equivalent to a short course of i.v. antibiotics followed by sequential conversion to oral (PO) antibiotics.

DESIGN

Prospective, randomized, clinical trial.

SETTING

Multicenter study in tertiary children's hospitals.

PATIENTS

Children (aged 5-18 years) with perforated appendicitis found at laparotomy.

INTERVENTION

Children were randomized after appendectomy either to a 10-day course of a combination of i.v. ampicillin, gentamicin sulfate, and clindamycin (n = 10); or to a short course of a combination of i.v. ampicillin, gentamicin, and clindamycin, followed by conversion to a combination of p.o. amoxicillin and clavulanate potassium plus metronidazole (n = 16).

MAIN OUTCOME MEASURES

The primary outcome measure was clinical success, which was rated as complete, partial, or failure. Secondary outcome measures included return of oral intake, duration of fever, return of normal white blood cell count, and patient charges. Treatment equivalence was determined using confidence interval analysis.

RESULTS

We found treatment equivalence between the i.v. and i.v./p.o. groups, with 6 (60%) complete and 4 (40%) partial successes for the 10 patients in the i.v. group and 15 (94%) complete and 1 (6%) partial successes for the 16 patients in the i.v./p.o. group (P< or =.05). There was no difference in return of oral intake, duration of fever, or return of normal white blood cell count between the groups. Conversion to oral therapy results in savings of approximately $1500 per case.

CONCLUSION

There is treatment equivalence between prolonged i.v. therapy and i.v. therapy followed by conversion to oral antibiotic therapy in children with perforated appendicitis.

Vascular control for resection of suprahepatic intracaval Wilms' tumor: technical considerations

The surgical resection of Wilms' tumor can be complicated by tumor thrombus extension into the inferior vena cava. In cases of suprahepatic Wilms' tumor thrombus that may extend into the right atrium, a median sternotomy and cardiopulmonary bypass (CPB) are used to facilitate tumor resection. However, if the tumor can be localized and controlled below the atrium, resection without the use of cardiopulmonary bypass may limit morbidity. The authors describe a novel approach to tumor thrombectomy for a Wilms' tumor extending to the suprahepatic vena cava without the use of CPB. The authors used transesophageal echocardiography to localize the tumor thrombus and detect any tumor or air embolization and a minimal lower sternotomy to obtain intrapericardial control of the inferior vena cava. This technique may be useful in selected cases of Wilms' tumor as an alternative to median sternotomy and use of cardiopulmonary bypass.

Juvenile papillomatosis of the breast in male infants: two case reports

Juvenile papillomatosis of the breast ("Swiss cheese disease") is a benign localized proliferative condition of the breast which occurs almost exclusively in young adult women. Patients with this lesion often have a family history of breast carcinoma, and rarely carcinoma may coexist with the lesion at the time of diagnosis. We present two cases of male infants with juvenile papillomatosis of the breast. The pathology and clinical management of this novel lesion is discussed.

Current management of pediatric inflammatory bowel disease

Inflammatory bowel disease (IBD) is a relatively rare condition of childhood, although the wide range of presenting complaints, scope of complications, and choices of therapy for this condition make it particularly difficult to treat in children. Novel approaches to the management of Crohn's disease and ulcerative colitis have gained recent favor. This report summarizes the current medical and surgical management of IBD, recent advancements in clinical therapies, and particular aspects of IBD care for children.

Transplantation of thymus tissue in complete DiGeorge syndrome

BACKGROUND

The DiGeorge syndrome is a congenital disorder that affects the heart, parathyroid glands, and thymus. In complete DiGeorge syndrome, patients have severely reduced T-cell function.

METHODS

We treated five infants (age, one to four months) with complete DiGeorge syndrome by transplantation of cultured postnatal thymus tissue. Follow-up evaluations included immune phenotyping and proliferative studies of peripheral-blood mononuclear cells plus biopsy of the thymus allograft. Thymic production of new T cells was assessed in peripheral blood by tests for T-cell-receptor recombination excision circles, which are formed from excised DNA during the rearrangement of T-cell-receptor genes.

RESULTS

After the transplantation of thymus tissue, T-cell proliferative responses to mitogens developed in four of the five patients. Two of the patients survived with restoration of immune function; three patients died from infection or abnormalities unrelated to transplantation. Biopsies of grafted thymus in the surviving patients showed normal morphologic features and active T-cell production. In three patients, donor T cells could be detected about four weeks after transplantation, although there was no evidence of graft-versus-host disease on biopsy or at autopsy. In one patient, the T-cell development within the graft was demonstrated to accompany the appearance of recently developed T cells in the periphery and coincided with the onset of normal T-cell function. In one patient, there was evidence of thymus function and CD45RA+CD62L+ T cells more than five years after transplantation.

CONCLUSIONS

In some infants with profound immunodeficiency and complete DiGeorge syndrome, the transplantation of thymus tissue can restore normal immune function. Early thymus transplantation - before the development of infectious complications - may promote successful immune reconstitution.

Does early ultrasonography affect management of pediatric appendicitis? A prospective analysis

BACKGROUND

Appendicitis remains a difficult diagnosis in children. Ultrasonography is increasingly used for the diagnosis of appendicitis, although the proper clinical role for this test remains unclear.

METHODS

To evaluate the clinical utility of ultrasonography in appendicitis, the authors analyzed prospectively all children evaluated for possible appendicitis from January 1 through December 31, 1997. Children with a high clinical suspicion of appendicitis were referred for surgery (n = 122). Children with equivocal findings of appendicitis were referred for early ultrasonography (EUS) and formed the study cohort (n = 103). An initial management plan was made to operate or observe each patient, and a risk of appendicitis (doubtful, possible, probable) was assigned by a pediatric surgery fellow. EUS was then performed, and its effect on management was assessed.

RESULTS

Using clinical judgment to operate at initial presentation, the sensitivity was 38% and specificity was 95%. Using EUS alone, the sensitivity was 87% and specificity was 88%. The management of 30 of 103 patients (30%) was changed after EUS, including a decision to operate in 28 patients and a decision not to operate in two patients.

CONCLUSIONS

EUS appears to have substantial clinical utility in children with equivocal findings of appendicitis, and its use complements the clinical management. The use of EUS can improve patient care and reduce hospital resource utilization.

Care of the surgical intensive care nursery graduate. The primary care pediatrician's perspective

Care of the intensive care nursery graduate may be quite challenging. It is important that primary care pediatricians become familiar with the complications unique to surgical patients so that they may properly prepare and educate parents and provide appropriate long-term follow-up for these often complex patients. Maintenance of a close relationship with the pediatric surgeon with an open line of communication regarding the approach to various surgical problems facilitates the effective integration of the intensive care nursery graduate into the primary care pediatrician's practice and provides the foundation for a successful clinical outcome.

Fluid therapy for the pediatric surgical patient

The fluid management of the pediatric surgical patient is a crucial aspect of surgical care. This article reviews the fundamental physiology of fluid replacement in children and highlights how standard formulas for fluid therapy can be modified to account for the rapidly changing physiology of the pediatric surgical patient. Novel approaches to fluid treatment of the surgical patient with oral rehydration formulas are discussed. Finally, guidelines for specific management of common pediatric surgical diseases are presented.

The biology and ethics of banking fetal liver hematopoietic stem cells for in utero transplantation

BACKGROUND/PURPOSE

Transplantation of fetal liver hematopoietic stem cells (HSCs) in utero has the potential to treat a variety of hematologic, immunologic, and metabolic diseases. One prerequisite for broad clinical application is the establishment of a bank of fetal liver HSC tissue. The authors describe their methods for processing fetal liver free of known human pathogens while maximizing HSC activity after cryopreservation.

METHODS

The authors developed a protocol that separates the abortion decision from the donation decision and preserves confidentiality between donor and recipient. Human fetal livers (12 to 14 weeks' gestation) were procured from aborted specimens and the light-density hematopoietic cells isolated by density centrifugation. Total viable cell count increased with gestational age and averaged from 4.36 x 10(7) cells for 12-week livers to 2.0 x 10(8) cells for 14-week livers.

RESULTS

Flow cytometric analysis demonstrated the presence of early progenitors in fresh and thawed specimens and a low number of T cells in each group. The functional capacity of fetal liver progenitors was assessed with colony-forming assays before and after cryopreservation. Thawed specimens showed an average 63% recovery rate for the high-proliferative potential colony-forming cells, a primitive subset of progenitors thought to include HSC. However, the more mature fraction of low-proliferative potential colony-forming cells had a recovery rate of only 35%. These data suggest that fetal liver HSC maybe more resistant to the detrimental effects of cryopreservation than mature progenitors. The fetal liver was screened for bacterial, fungal, and viral contaminates and the serum from donor mothers was screened for human immunodeficiency virus (HIV), hepatitis A, B, and C, human T-cell lymphoma virus (HTLV I/II), rapid plasma reagent (RPR), cytomegalovirus (CMV), and toxoplasmosis IgM. The bacterial contamination rate was 14% (n = 28). The maternal serum was positive for CMV in 78% of cases, and positive for hepatitis C in 0.7% of cases (n = 28). However, all fetal liver specimens were culture negative for CMV.

CONCLUSIONS

These findings demonstrate that human fetal liver HSCs can be procured ethically and processed to ensure a safe graft with a small number of T-cells, and a high yield of progenitors after cryopreservation. A bank of fetal liver HSC will prove useful in treating a variety of genetic diseases before birth by in utero HSC transplantation.

Morbid prognostic features in patients with chronic liver failure undergoing nonhepatic surgery

BACKGROUND

Although the risk of portal decompression surgery is accurately predicted by objective scoring systems (Child classification and Pugh score), few useful prognostic criteria exist regarding nonhepatic surgery in patients with chronic liver failure.

OBJECTIVE

To evaluate the clinical findings associated with perioperative mortality in patients with chronic liver failure undergoing nonhepatic surgery.

DESIGN

A retrospective cohort study.

SETTING

University teaching hospitals.

PATIENTS

Forty consecutive patients with an International Classification of Diseases, Ninth Revision (ICD-9), diagnosis of chronic liver failure and one or more of the following: jaundice, cirrhosis, chronic hepatitis, or alcoholism.

INTERVENTIONS

Forty operations, including 28 abdominal procedures, 2 coronary artery bypass grafts, 5 orthopedic procedures, and 5 miscellaneous procedures.

MAIN OUTCOME MEASURES

Thirty-day mortality as related to 19 preoperative clinical and laboratory variables.

RESULTS

Eleven (28%) of the patients died within 30 days of surgery. By univariate analysis, the following variables were significantly (P < .05, pearson chi 2 test for categorical data or Mann-Whitney U test for continuous data) associated with nonsurvival: encephalopathy, congestive heart failure, the need for emergent surgery, infection, hyperbilirubinemia, international normalized ratio greater than 1.6, hypoalbuminemia, and an elevated creatinine level. By multiple logistic regression analysis, an international normalized ratio greater than 1.6 and encephalopathy were associated with a greater than 10- and 35-fold increased mortality risk, respectively. Child classification and Pugh score failed to predict 30-day mortality.

CONCLUSIONS

We identified 8 clinical and laboratory variables associated with death within 30 days in patients with chronic liver failure undergoing nonhepatic surgery. Two factors-international normalized ratio greater than 1.6 and encephalopathy-independently predicted mortality by multivariate analysis. Neither Child classification nor Pugh score was prognostically helpful. Nonhepatic surgery confers a substantial mortality risk in patients with chronic liver failure.

In utero hematopoietic stem cell transplants prolong survival of postnatal kidney transplantation in monkeys

The authors hypothesized that in utero transplantation of T-cell-depleted paternal marrow into rhesus monkey fetuses would induce tolerance to postnatal kidney grafts from the marrow donor. T-cell-depleted paternal bone marrow was transplanted intraperitoneally into two female fetal rhesus monkeys at 61 +/- 1 days' gestation. Chimeric monkeys (n = 2) received kidney transplants from paternal donors. Control monkeys (n = 2) underwent kidney transplants without prior in utero stem cell transplants. Both chimeric monkeys demonstrated low level (<0.1% donor cells) engraftment in the bone marrow and peripheral blood using the polymerase chain reaction assay for the Y chromosome. The mixed lymphocyte reaction demonstrated hyporeactivity to the donor. Control animals demonstrated severe acute rejection and graft failure 1 week posttransplant. The first chimeric monkey had no significant clinical or sonographic evidence of renal failure until 7 weeks after the transplant. Biopsy findings showed mild rejection 1 week postoperatively, but rejection did not significantly progress until 5 weeks later. The second chimeric monkey had no significant clinical or sonographic changes for 4 weeks, but evidence of moderate rejection was seen on biopsy results. This monkey was given a 10-week course of immunosuppression, and had no clinical or sonographic renal deterioration, although biopsy results showed chronic rejection that was confirmed when electively euthanized 8 months later. Our data suggest that in utero transplantation of hematopoietic stem cells can increase the survival of a kidney allograft in the rhesus monkey.

Ruptured Salmonella mycotic aneurysm of the extracranial carotid artery

Mycotic aneurysms of the extracranial carotid artery are rare and difficult to diagnose and can lead to significant medical morbidity. Treatment of these lesions requires expert surgical management and necessitates an assiduous search for an underlying source. We report a case of a ruptured mycotic aneurysm of the cervical carotid artery due to Salmonella infection successfully treated by wide excision and saphenous vein patch angioplasty.

Familial diaphragmatic agenesis: an autosomal-recessive syndrome with a poor prognosis

Diaphragmatic agenesis is a severe form of congenital diaphragmatic hernia for which an autosomal recessive form of inheritance has been proposed. The authors report six families with 13 pregnancies with diaphragmatic agenesis in which inheritance followed an autosomal recessive pattern, including the first reported case of bilateral diaphragmatic agenesis in twins. None of the thirteen affected fetuses survived. Familial diaphragmatic agenesis appears to be a distinct clinical entity with a worse prognosis than posterolateral diaphragmatic hernia.

Enhancement of human hematopoiesis by mast cell growth factor in human-sheep chimeras created by the in utero transplantation of human fetal hematopoietic cells

We have previously described a unique model of long-term, multilineage, human hematopoietic chimerism in sheep created by the in utero transplantation of human hematopoietic stem cells (HSC) into pre-immune fetal lambs. In this study, we examined the effect of chronic administration of recombinant human mast cell growth factor (rhMGF) on 1) human cell engraftment in pre-immune sheep and 2) human cell expression in human-sheep chimeras at 2-years posttransplant. rhMGF (25 micrograms/kg) or saline was administered in utero via chronic intraperitoneal (IP) catheters to three separate sets of twin fetuses on alternate days for 10 doses following transplantation of human HSC. Flow-cytometric and karyotype analyses of peripheral blood from two sets of twins at 45-days posttransplant and of peripheral blood from the remaining set of twins at birth revealed a significant increase in percentages of donor (human) progenitors and cells in rhMGF-treated lambs. rhMGF (60 micrograms/kg/day) was also administered by IP injection to two, 2 year-old, human-sheep chimeras for 18 consecutive days. Flow-cytometric analysis of peripheral blood and bone marrow revealed a six- to seven-fold increase in human cell expression. The effect on early human progenitors (i.e., colony-forming unit-mix [CFU-Mix], CFU granulocyte/macrophage [CFU-GM], and burst-forming unit-erythroid [BFU-E]) was determined by karyotype analysis of individual colonies grown under conditions favoring human cell growth. A three- to five-fold increase in human CFU-Mix and BFU-E occurred with a minimal increase in CFU-GM. This in vivo study supports in vitro data suggesting that MGF is a powerful regulator of human hematopoiesis and preferentially stimulates early hematopoietic progenitors. It also supports the potential value of the human-sheep model for the in vivo study of normal and abnormal human hematopoiesis.

An effective strategy for decontamination, ex vivo expansion, and storage of human fetal liver hematopoietic stem cells

The transplantation of human fetal tissue has the potential to cure a variety of life-threatening diseases. The strategy for procurement, quality control, and functional assessment of human fetal liver HSC may prove useful for the transplantation of other fetal tissues. In addition to technical limitations, there are ethical and legal issues which need to be resolved before widespread use of fetal tissue. Further development of regulatory standards for the acquisition and distribution of fetal tissues will foster the application of this novel technology.

Massive thymic hyperplasia: characterization of a rare mediastinal mass

Thymic hyperplasia is a rare cause of an anterior mediastinal mass in children. True thymic hyperplasia is characterized by massive thymic hypertrophy with retention of normal thymic architecture, and must be distinguished from more commonly seen tumors of the anterior mediastinum. Previous reports of thymic hyperplasia primarily have been descriptive, with minimal analysis of the cellular characteristics of the tumor. To better describe the cellular characteristics of thymic hyperplasia, the authors report on a 10-year-old boy found to have an asymptomatic left paracardiac mass during cardiac evaluation. The mass enlarged rapidly during the following 2 weeks and filled the entire left side of the chest. An open biopsy specimen showed normal thymic architecture. Because of the size and rapid growth of the mass, the authors decided to resect it. Cellular analysis of the mass did not show differences from normal thymic elements. There was conserved thymic architecture. The expression of cell surface markers and the proliferative response of thymocytes to cytokines appeared to be normal. Similarly, a long-term cell culture of the thymocytes did not result in clonal proliferation. Immunohistologic staining of stromal cells showed no striking differences from normal thymic elements. Moreover, immunologic analysis of the patient by standard hematological parameters, lymphocyte subsets, quantitative immunoglobins, and immunoelectrophoresis showed no abnormalities except for lymphocytosis, which resolved after tumor resection. The authors conclude that thymic hyperplasia occurs in immunologically normal children and may exhibit (1) rapid growth with minimal associated symptoms, (2) normal thymic architecture, (3) normal thymocyte and stromal growth characteristics in vitro, and (4) a normal thymocyte response to cytokine stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital cystic adenomatoid malformation: a sheep model of fetal hydrops

Congenital cystic adenomatoid malformation (CCAM) can be diagnosed in utero. Nonimmune hydrops associated with CCAM is a predictor of fetal demise. Fetuses with prenatally diagnosed large CCAM tumors and hydrops have undergone successful in utero resection. An animal model is needed to understand the pathophysiology of CCAM and hydrops. To create a model of CCAM and hydrops, the authors implanted an intrathoracic tissue expander in six fetal sheep at 120 days' gestation. The inflatable tissue expander was implanted in the right side of the chest, and arterial, venous, intrathoracic, and intraamniotic pressure catheters were placed. Each day, the expander was inflated with 25 to 50 mL of saline (maximum, 150 mL), ultrasound examination was performed, and all pressure measurements were taken. In all six fetuses, hydrops developed after expander inflation. Expander inflation correlated with an increase in central venous pressure (CVP) (4 +/- 2 mm Hg v 16 +/- 2 mm Hg [mean +/- SD]; P < .05). To simulate in utero CCAM resection, the expander was deflated in four hydropic sheep, resulting in return of the CVP to near baseline and resolution of hydrops. Silicone vascular casts of two postmortem sheep demonstrated lateral displacement and compression of the vena cavae by the expander. The authors successfully created a model of CCAM and hydrops by inflating an intrathoracic tissue expander in fetal sheep. Based on this model, hydrops associated with CCAM results from obstruction of cardiac venous return and central venous hypertension. This pathophysiology is reversed by expander deflation, which simulates in utero CCAM resection.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic fetal vascular access

Intensive management of the fetus is limited by our inability to achieve access to the fetal circulation. Using laparoscopic surgery, we can maintain long-term access to the fetal circulation by extra-amniotic catheterisation of chorionic vessels in third-trimester monkeys and early-gestation sheep. We can sample fetal blood, continuously measure blood pressure, and infuse drugs without complications. Safe vascular access will permit assessment of fetal status during fetal surgical procedures and improve postoperative monitoring.

Prenatal diagnosis: essentials for the pediatric surgeon

Prenatal diagnosis is a rapidly growing field that has supported new treatments for the developing fetus. Improved methods of diagnosing anatomic, biochemical, and molecular defects of the fetus have fostered a parallel growth of better techniques of fetal therapy. A fundamental knowledge of the basic uses and limitation of prenatal diagnosis is essential for the practicing pediatric surgeon. This review summarizes clinical uses and recent advances in various methods of prenatal diagnosis, including ultrasound, fetal echocardiography, amniocentesis, chorionic villus sampling, fetal blood sampling, alpha-fetoprotein, and DNA analysis. For each technique, the common indications, risks, and clinical utility are discussed.

Effect of xenogeneic chimerism in a human/sheep model on natural antibody

Xenogeneic transplantation is a potential solution to the severe shortage of donor organs for clinical transplantation. The primary limitation to xenogeneic transplantation between widely disparate species is hyperacute rejection, which is triggered by the recipient's natural antibodies reacting against the donor's endothelial cells. Natural antibodies react between widely disparate species but do not react between closely related species. Specific tolerance for xenogeneic transplantation between closely related species can be induced by creating hematopoietic chimerism between donor and recipient. However, whether specific xenograft tolerance can be induced by the creation of chimerism between widely disparate species, where natural antibody reacts, is unknown. We previously have established a model of hematopoietic chimerism between widely disparate species by the in utero transplantation of human fetal hematopoietic stem cells into early gestation fetal lambs. In the present study, we determined whether long-standing hematopoietic chimerism in this human/sheep model reduces the level of natural antibody directed against human endothelial cells. To answer this question, we measured the reactivity of serum from five chimeric sheep, five sheep controls, and five human controls in an in vitro enzyme-linked immunoabsorbance assay directed against human umbilical vein endothelial cells. Unexpectedly, we found that long-standing hematopoietic chimerism in the human/sheep model did not reduce the reactivity of serum against human endothelial cells compared to age-matched sheep controls. These results suggest that the induction of hematopoietic chimerism between widely disparate species will not control the problem of natural antibody and hyperacute rejection.

Bacterial and fungal contamination of human fetal liver collected transvaginally for hematopoietic stem cell transplantation

Transplantation of fetal hematopoietic stem cells is a new therapy for fetuses diagnosed in utero with inherited disorders. However, prior to transplantation of fetal stem cells, the cells must be free of microbial contamination. In order to investigate the contamination of human fetal liver tissue, we determined the rate and types of bacterial and fungal contamination of human fetal liver tissue collected transvaginally for use in stem cell transplantation by using the US Pharmacopoiea Assay. We found a high rate of contamination with bacteria or fungi (12 of the 14 fetal livers, or 85%). Non-fermenting gram-negative rods were the predominant contaminants. The high rate of microbial contamination of fetal tissue suggests that techniques for tissue collection need to be improved before fetal stem cells are used for clinical transplantation.

Bench coronary cineangiography. A possible way to increase the number of hearts available for transplantation

The method of "bench coronary cineangiography," that is, ex vivo contrast examination of the donor heart before implantation, is presented. The procedure appears to be most effective in detecting pathologic changes in the coronary arterial system of the explanted heart and thus would allow substantial extension of the age limits of donor hearts that may be acceptable for transplantation.

Prevention of retrovirus infection after injury with contaminated instruments: an experimental study

Owing to similarities between human immunodeficiency virus and feline retroviruses, the feline model was chosen for the study to investigate the efficacy of timely topical treatment of accidental human immunodeficiency virus infection in the operating room. Cats were subcutaneously inoculated with either feline leukemia virus or feline immunodeficiency virus. An effort was made to neutralize the virus in loco either by infiltration of the inoculation site with povidone-iodine or with monoclonal antibodies, or by cauterization and excision. The animals were periodically monitored for feline leukemia virus antigens or for feline immunodeficiency virus antibodies. The results indicated that in the feline model, the development of generalized virus infection may be prevented by local measures if applied immediately.

Dose-dependent reduction of myocardial infarct size with the perfluorochemical Fluosol-DA

The perfluorochemical Fluosol-DA has been shown to reduce infarct size. However, the dose-response relationship of the agent is unknown. Because perfluorochemicals (PFC) can potentially saturate the reticuloendothelial system and decrease carbon clearance as well as cause a transient elevation in liver enzymes, the present study was conducted to determine the lowest effective dose. New Zealand White rabbits (n = 73) were randomly selected prior to infarction to receive 10, 15, 20, 25, or 30 ml/kg PFC or an equivalent volume of 5% dextran (control) intravenously. Animals underwent 30 minutes of coronary artery occlusion with PFC or dextran infused over a 30-minute period starting at 20 minutes into the occlusion. Animals were put to death at 24 hours and infarct size was determined histologically and quantitated by computerized planimetry. Neutrophil infiltration into the ischemic myocardium was evaluated semiquantitatively. No hemodynamic differences were noted within groups. Infarct size was similar to that of controls in animals treated with 10 or 15 ml/kg PFC. Significant infarct size reduction, however, was noted in animals treated with 20, 25, and 30 ml/kg PFC versus controls; (p = 0.05, 0.04, and 0.02, respectively). Maximal infarct size reduction was seen with 30 ml/kg PFC (35%). Neutrophil infiltration was significantly decreased in all groups treated with PFC. These results show that intravenous Fluosol-DA significantly reduces infarct size at a minimal dose of 20 ml/kg.

Can AIDS be prevented after injury with contaminated instruments?

Particulate matter comparable in size with that of human immunodeficiency virus was subcutaneously injected into experimental animals. Such matter remained at the inoculation site long enough to suggest the possibility that human immunodeficiency virus can be destroyed in loco before it invades the host's circulation. These findings may be useful in developing a method to prevent acquired immunodeficiency syndrome after accidental injury with human immunodeficiency virus-contaminated instruments.

Vascular reactivity during the progression of atherosclerotic plaque. A study in Watanabe heritable hyperlipidemic rabbits

The effects of varying degrees of atherosclerotic plaque on vascular responsiveness in aortas of Watanabe heritable hyperlipidemic (WHHL) rabbits and New Zealand White (normal cholesterolemic) rabbits were studied. Ring segments from the aortic arch and thoracic aorta were mounted in organ chambers for isometric tension recording and measurement of endothelium-derived relaxing factor. WHHL rabbits were divided into three groups according to age: group 1, 3-5 months; group 2, 6-9 months; and group 3, 12-14 months. Atherosclerotic changes (expressed as a percent of total surface area) in the aortic arches in groups 1, 2, and 3 were 11 +/- 3% (mild), 28 +/- 6% (moderate), and 54 +/- 8% (severe) respectively; only occasional plaques were present in the thoracic aorta in all groups. Maximal contractions elicited with phenylephrine progressively decreased with increasing degrees of atherosclerotic plaque. Contractions evoked by histamine were augmented in all groups of WHHL rabbits when compared with controls, whereas those to serotonin were augmented only in vessels with mild atherosclerosis. As the severity of the intimal lesions increased, endothelium-dependent relaxations to acetylcholine, ATP, and calcium ionophore A23187 progressively decreased. Endothelium-independent relaxation to nitroglycerin was virtually complete in all segments. However, vessels with severe atherosclerosis were less sensitive to this agent as illustrated by a significant increase in the ED50 value. Scanning electron microscopy revealed a predominant loss of endothelial cells in the central regions of fibrous plaques. Thus, in WHHL rabbits, hypercholesterolemia and atherosclerosis result in an increased responsiveness of vascular smooth muscle to histamine and serotonin. Endothelium-mediated relaxation of vascular smooth muscle is reduced with the progression of atherosclerosis primarily due to a loss of endothelial cells.

Biological thresholds of cold-induced phrenic nerve injury

The effects of controlled cooling on phrenic nerve signal conduction were investigated by cooling an isolated segment of the phrenic nerve with a constant but variable temperature probe. The conduction of a standard electrical stimulus applied to the nerve proximal to the cooled section was measured by detector electrodes sutured to the diaphragm. Nerve conduction of the applied stimulus ceased between 10 degrees and 12 degrees C but returned within seconds after the probe was removed. The delay in the return of conduction increased as nerve temperature decreased until at a temperature of 4 degrees C the ability to conduct did not return after 4 hours. The amount of fat surrounding the nerve and the blood flow rate along the cooled portion of the nerve were observed to ameliorate the effects of low temperature on stimulus conduction. Total body cooling also appears to offer some protection against loss of conduction.

Experiments with a bowl of saline: the hidden risk of hypothermic-osmotic damage during topical cardiac cooling

Some of the misconceptions in the application of cardiac hypothermia are that the temperature of cold normal saline solution is necessarily above 0 degrees C, cold saline solution and slush are relatively safe for living tissues, and normal saline will retain normal osmolality even if partially frozen. These postulates were examined in thermodynamic experiments that demonstrated three points: (1) The temperature of unfrozen saline solution may drop way below the freezing point. (2) When liquids and solid components of saline solution are separated, the components will become hypo-osmolar or hyperosmolar. (3) Ice chips and slush ice produced in the operating rooms may reach temperatures as low as -36 degrees C. We recommend that the possibility of these events should be taken into consideration whenever topical cardiac hypothermia is clinically applied.

Platelet alpha 2-adrenergic receptors in schizophrenic patients before and after phenothiazine treatment

The specific binding to isolated platelet membranes of 3H-clonidine, an alpha 2-adrenergic receptor partial agonist, and 3H-yohimbine, an alpha 2-adrenergic receptor antagonist, was measured in male, drug-free schizophrenic patients. The maximum number of binding sites (Bmax) for 3H-yohimbine was significantly lower in these patients than in normal subjects. Treatment with chlorpromazine (CPZ) for 2 weeks further decreased the Bmax for both ligands. Plasma catecholamine levels were determined before and after treatment. Before treatment, levels of dopamine and norepinephrine (NE) were within a normal range, while epinephrine (E) levels were significantly elevated. CPZ treatment significantly increased plasma NE levels, but decreased E levels to a normal range. These observations suggest that schizophrenia might be associated with abnormal noradrenergic function that is reflected by a decreased number of platelet alpha 2-adrenergic receptors.