Biomedical subjects

A Cnaan

Publications and source records attributed to A Cnaan.

At least 55 records · Page 3Linked to original sources

PubMed1998

Hidden spears: handlebars as injury hazards to children.

OBJECTIVES: To delineate the mechanism of serious bicycle handlebar-related injuries in children and make recommendations for preventive strategies. METHODS: Prospective cross-sectional surveillance system of seriously injured child bicyclists supplemented by in-depth, on-site crash investigation to delineate specific injury mechanisms. Interdisciplinary analyses involved engineers, clinicians, epidemiologists, and biostatisticians. SETTING: The emergency department and in-patient trauma service of an urban level one pediatric trauma center between October 1995 and September 1997. PARTICIPANTS: Patients under 18 years of age who were treated for serious bicycle-related injuries (Abbreviated Injury Scale scores of 2 or greater). RESULTS: The surveillance system identified two distinct circumstances for serious child bicyclist injury: 1) handlebar-related injuries associated with minor incidents (falls from bicycles) and 2) nonhandlebar-related injuries associated with severe incidents (bicycle-motor vehicle crashes). Crash investigations explored the minor incidents that resulted in serious handlebar-associated injuries. In the typical mechanism, as the child lost control of the bicycle and began to fall, the front wheel rotated into a plane perpendicular to the child's body. The child then landed on the end of the handlebar resulting in serious truncal injuries. CONCLUSIONS: A discordancy exists between the apparently minor circumstances and serious injuries sustained by child bicyclists who impact bicycle handlebars. Recognition of the mechanism of handlebar-related injuries might aid the practitioner in early diagnosis of serious abdominal injuries in child bicyclists. This injury mechanism may be avoided through bicycle redesign that would involve both limiting rotation of the front wheel and modifying the ends of handlebars. An integrated approach involving a surveillance system to identify an injury hazard supplemented by in-depth, on-site crash investigations effectively provided the detailed mechanism of injury needed to develop interventions.

Abdominal Injuries↗

PubMed1998

Clinical correlations with carbohydrate-deficient transferrin levels in women with alcoholism.

Carbohydrate-deficient transferrin (CDT) has received increasing attention as a potential biological marker for heavy drinking or as an objective marker of relapse in patients who are treated for alcohol dependence. Previous studies have demonstrated the utility of CDT among men, but there are fewer and inconsistent reports on the utility of CDT among women. This study reports in a sample of 40 alcohol-dependent women, the association between CDT levels, and several different types of measures of drinking intensity including frequency of heavy drinking. Although the majority of drinking indices correlated with CDT levels in men, among women, CDT levels were significantly correlated with the percentage of days of heavy drinking when heavy drinking day was defined as drinking 6 or more drinks per drinking day. The results also support an association between current menstrual function, CDT levels, and drinking indices. These findings suggest that the pattern of drinking (combining high frequency and high intensity) may be an important determinant of CDT levels in women with alcohol dependence, compared with men.

Adult↗

PubMed1997

Using the general linear mixed model to analyse unbalanced repeated measures and longitudinal data.

The general linear mixed model provides a useful approach for analysing a wide variety of data structures which practising statisticians often encounter. Two such data structures which can be problematic to analyse are unbalanced repeated measures data and longitudinal data. Owing to recent advances in methods and software, the mixed model analysis is now readily available to data analysts. The model is similar in many respects to ordinary multiple regression, but because it allows correlation between the observations, it requires additional work to specify models and to assess goodness-of-fit. The extra complexity involved is compensated for by the additional flexibility it provides in model fitting. The purpose of this tutorial is to provide readers with a sufficient introduction to the theory to understand the method and a more extensive discussion of model fitting and checking in order to provide guidelines for its use. We provide two detailed case studies, one a clinical trial with repeated measures and dropouts, and one an epidemiological survey with longitudinal follow-up.

Adolescent↗

PubMed1997

High levels of expression and nuclear localization of interleukin-1 beta converting enzyme (ICE) and CPP32 in favorable human neuroblastomas.

Neuroblastomas frequently show spontaneous regression and differentiation, which may at least partly be regulated by signaling through nerve growth factor and its receptors, TRK-A and p75LNTR. We studied 52 neuroblastic tumors to test whether the cell death-related proteases, interleukin-1 beta converting enzyme (ICE), CPP32, and Ich-1, were involved in the regression of the tumors. High levels of expression of ICE and CPP32 were significantly correlated with a high level of TRK-A expression, single copy of N-myc, younger age, lower stages, and better prognosis. The immunohistochemical studies and Western analyses as well as the terminal dUTP-biotin nick end labeling (TUNEL) method revealed that both ICE and CPP32 were translocated from the cytoplasm into the nuclei in regressing, apoptotic tumor cells. Our results suggest that ICE and CPP32 cysteine proteases may play an important role in regulating the apoptotic process of the favorable neuroblastomas.

Age Factors↗

PubMed1997

Adjuvant chemotherapy for the treatment of intracranial ependymoma of childhood.

BACKGROUND: Current treatment for childhood intracranial ependymomas with surgery and radiation therapy (RT) yields 5-year survival rates ranging from 50-70% after complete resection to 0-30% after incomplete surgical resection. The role of chemotherapy in the treatment of ependymoma has not been established. In this pilot study, children with newly diagnosed intracranial ependymoma were treated with RT and chemotherapy using agents comparable to those found to be active in the treatment of intracranial ependymoma in infants. METHODS: Nineteen children age 3-14 years (median, 7.5 years) were treated with postoperative RT and chemotherapy. Chemotherapy was comprised of carboplatin, 560 mg/m2, with vincristine, 1.5 mg/m2, weekly for 3 weeks, alternating at 4-week intervals with ifosfamide, 1.8 g/m2, and etoposide, 100 mg/m2, for 5 consecutive days for a total of 4 cycles. RESULTS: The 5-year progression free survival (PFS) estimate was 74%. The extent of surgical resection was not a significant prognostic factor in this study. By contrast, ependymomas located in the posterior fossa were associated with a higher rate of progression (P = 0.036). Toxicity, limited predominantly to myelosuppression, was manageable. CONCLUSIONS: The PFS for children with postoperative residual ependymoma treated with RT and chemotherapy in this study was higher than published survival results for RT alone. These results suggest a role for multialkylator chemotherapy in incompletely resected intracranial ependymoma and provide the rationale for a randomized trial comparing this strategy with conventional postoperative RT.

Adolescent↗

PubMed1997

Histology of rat small bowel transplants: cyclosporine A ameliorates features of rejection including apoptosis and ganglion cell reduction.

The histology of rat small bowel transplants (SBT) was examined in orthotopic isografts and allografts with and without immunosuppression. Lewis to Lewis isografts were examined 7 days after transplant, and LBNF1 to Lewis allografts were examined 2, 4, 7, and 10 days after transplant; one group received cyclosporine A (CyA), and their allografts were examined 7 days after transplant. Compared with similar intestinal segments from unoperated animals, allografts at 4, 7, and 10 days after surgery showed progressive inflammation, cryptitis, villous atrophy, and transmural necrosis. In contrast, SBT in animals given CyA did not significantly differ from normal in any histological parameter. The number of apoptotic structures per 100 crypts in SBT at day 4 (58.25 +/- 32.98) and day 7 (31.86 +/- 27.63) after transplant were significantly increased compared with unoperated bowel (5.23 +/- 13.41) (P < .05); the number in CyA-treated allografts (11.57 +/- 29.56) did not differ significantly from normal. The number of intermyenteric ganglion cells was significantly reduced (P< .05) in allografts 7 and 10 days after transplant (mean and [range] = 31 [18 to 38] and 25 [23 to 27], respectively) but the number in allografts from CyA-treated animals (47 [24 to 72]) did not differ from unoperated bowels (52 [30 to 88]). We conclude that CyA treatment significantly reduces the histological abnormalities associated with transplant rejection including adverse effects on epithelial and ganglion cells; therefore, the absorptive capacity and motility characteristics of the CyA-treated SBT should be preserved compared with untreated allograft controls.

Animals↗

PubMed1997

Prognostic signs in the surgical management of plexiform neurofibroma: the Children's Hospital of Philadelphia experience, 1974-1994.

OBJECTIVES: To estimate the rate of progression of plexiform neurofibroma after surgery and to identify prognostic factors that predict progression. STUDY DESIGN: A retrospective review of the inpatient and outpatient records of 121 patients, who had 302 procedures on 168 tumors over a 20-year period at a single large pediatric referral center. Data on age, location, indication for surgery, and extent of resection was analyzed for prognostic significance. RESULTS: The overall freedom from progression was 54%. Children < 10 years old had a shorter interval of tumor control than older children (p = 0.0004). Tumors of the head/neck/face fared worse than tumors of the extremities (p = 0.0003). Less extensive resection predicted shorter interval to progression (p < 0.0001). Indication for surgery was not of prognostic importance. In multivariable analysis older age and location in the extremities were predictors of a better outcome. CONCLUSIONS: Tumor progression is a serious problem for children with plexiform neurofibroma. Younger children, children with tumors of the head/neck/face, and tumors that cannot be nearly completely removed are at particular risk. These data may be useful in helping clinicians decide which patients and which tumors are most likely to benefit from surgical intervention.

Adolescent↗

PubMed1997

Impact of changes in catheter management on infectious complications among children with central venous catheters.

OBJECTIVES: To characterize and enumerate central venous catheter (CVC)-related complications among children with chronic illnesses, and to reduce the complication rate through changes in CVC management and education. DESIGN: A prospective observational study followed by an educational program and a nonrandomized interventional trial. SETTING: The Children's Hospital of Philadelphia, a tertiary, pediatric facility. PATIENTS: 268 children with Broviac, Hickman, or Infusaport catheters in place during 58,290 catheter days. INTERVENTIONS: Development and implementation of protocols for cleaning insertion site and hub, use of nonocclusive dressings, and manipulation of access; formal staff and parental education about protocols. RESULTS: CVC-related infections fell from 4.58/1,000 catheter-days preintervention to 3.83 postintervention (risk ratio [RR], 0.20; 95% confidence interval [CI95], 0.89-1.622; P = .25); exit-site infections fell from 0.58 to 0.11 (CI95, 1.22-45.64; P = .02); rates among infants on the surgical service fell from 15.46 to 6.67 (RR, 2.31; CI95, 1.10-4.30; P = .02). CONCLUSIONS: Education and changes in management protocols reduced the incidence of exit-site infections among all patients and reduced the overall infectious complication rate among the infants receiving parenteral nutrition on the surgical service. Other interventions are needed to decrease further the infectious complications in these children.

Catheterization, Central Venous↗

PubMed1997

erbB-2 oncoprotein expression in breast carcinoma. Poor prognosis associated with high degree of cytoplasmic positivity using CB-11 antibody.

The relationship between immunohistochemically measured membranous expression of erbB-2 oncoprotein and prognosis in breast cancer is controversial, and the relationship between cytoplasmic positivity and prognosis has been minimally investigated. The clinical course of 300 women with infiltrating breast carcinoma, whose tumors were stained for erbB-2 oncoprotein with CB-11 monoclonal antibody, was followed for 5 to 79 months (median, 41 months). Higher numbers of cancer-related deaths were observed in patients with moderate-to-strong cytoplasmic positivity (15/60, 25%) and strong membranous positivity (9/29, 31%) than in patients with negatively stained tumors (8/53, 15%) or tumors with weaker degrees of cytoplasmic or membranous positivity (rate similar to or less than negative tumors). Relapse-free survival was also significantly shorter in patients with tumors with strong membranous positivity and moderate-to-strong cytoplasmic positivity; much of the latter relationship was due to a high number of patients who had erbB-2-positive tumors and who were never disease free. A significant association between decreased relapse-free survival and moderate-to-strong cytoplasmic (but not membranous) positivity persisted even after correction for other variables associated with poor outcome (histologic grade, tumor size, lymph node involvement, and hormone receptor status). Moderate-to-strong erbB-2 oncoprotein cytoplasmic positivity, measured with CB-11 antibody, is associated with a poor prognosis and seems to have biologic significance.

Breast Neoplasms↗

PubMed1997

Immune responses in mothers of term and preterm very-low-birth-weight infants.

Differences in the levels of immune cell subsets present in peripheral blood have been demonstrated based on sociodemographic factors such as age and race. Postpartal women, who are recovering from the immune changes that are concomitant with pregnancy, have lymphocyte and monocyte values that differ from other populations. A subgroup of postpartal women, mothers who deliver preterm very-low-birth-weight (VLBW) (< or = 1,500 g) infants, may have further differences in values of immune cell subsets and in immune functioning either because of hormonal factors or lifestyle changes or because of the stress they experience after their infant's birth and for the first few months of infant caretaking. This study examined anxiety, depression, and immune cell phenotypes in 30 mothers of VLBW infants and in 30 mothers of healthy term infants over the first 4 postpartal months to determine if mothers of preterm VLBW infants differed from mothers of healthy term infants in psychological and immunologic parameters. Additionally, lymphocyte proliferation and natural killer cell functional assays were performed in a subset of mothers. Mothers of VLBW infants had increased anxiety and decreased lymphocyte proliferation compared to mothers of term infants. When lymphocyte and monocyte subsets were compared over time between the two groups of mothers differences were found in CD8, CD20, CD3-/CD56+, CD14, and HLA class II Ia on monocytes. Mothers with high-fat diets had lower percentages of some monocytes (CD14), lymphocytes (CD4+/CD45RA+), and natural killer cells (CD3-/CD57+) during the first 4 postpartal months.

Adult↗

PubMed1997

An expanded neonatal morbidity scale for premature infants.

We revised a neonatal morbidity scale (the NMS) that has served as a means for comparison of neonatal illness in studies of high-risk neonates after initial hospital discharge. With an inception cohort approach, 89 premature infants at an urban university hospital were studied with the expanded scale (the ENMS). The original scale, published in 1983, was reworked and expanded based on advances in the diagnosis and management of neonates. A social risk scale was added. Linear and logistic regression analyses were used to judge validity of the newly revised scale and to examine its predictive ability for outcomes at six months of age. Concurrent validity was supported by the relationship between the ENMS-SRS and: birthweight (R2 = .54), gestational age (R2 = .50), length of stay (R2 = .47). Inter-rater reliability was .95. The ENMS, embodying a contemporary patient profile, is valid for a population of premature infants in a U.S. urban setting and has predictive validity for a few outcomes within six months of discharge from a special care unit.

Female↗

PubMed1996

Substance P modulates human immunodeficiency virus replication in human peripheral blood monocyte-derived macrophages.

Substance P (SP), a member of the tachykinin family of neuropeptides, is an important immunomodulator of lymphocyte and monocyte/macrophage function. We have examined the effects of SP on human immunodeficiency virus type 1 (HIV-1) infection of peripheral blood monocyte-derived macrophages (MDMs) in vitro. Human monocytes isolated by Ficoll gradient followed by adherence were maintained in vitro for 10 days and infected with HIV-1. The addition of SP resulted in a 2- to 8-fold-enhanced HIV-1 expression in the MDMs isolated from 7 of 13 healthy donors as determined by reverse transcriptase (RT) activity and p24 protein expression assays, as compared to control cultures incubated with HIV-1 alone. There was no correlation observed, however, between SP-stimulated TNF production and HIV-1 expression in MDMs obtained from a subset of these donors. These effects of SP on HIV-1 expression in MDMs in vitro may have in vivo implications relevant to modulation of monocyte/macrophage functions, to HIV-1 infection of monocytes/macrophages, and to the immunopathogenesis of HIV-1 infection.

Cells, Cultured↗

PubMed1996

Response of human immunodeficiency virus-exposed and -infected infants to Haemophilus influenzae type b conjugate vaccine.

OBJECTIVE: To evaluate the response of human immunodeficiency virus (HIV)-infected and -exposed infants to the primary series and booster dose of Haemophilus influenzae type b (Hib) conjugate vaccine. DESIGN: Retrospective study. PATIENTS AND SETTING: The HIV-exposed and -infected infants who were attending the Special Immunology Family Clinic at The Children's Hospital of Philadelphia (Pa). MAIN OUTCOME MEASURES: Geometric mean antibody titers (GMTs) to Hib polyribosyl ribitol phosphate capsular antigen were assessed after the primary series and again after the 15-month booster doses. In addition, the percentages of patients who responded with polyribosyl ribitol phosphate antibody levels greater than both 0.15 and 1.0 mg/L were compared between groups. RESULTS: After the 3-dose primary series, the GMTs were lower in the HIV-infected infants compared with those in the HIV-exposed, uninfected infants (0.86 vs 2.30, P = .02). Forty-six percent of the HIV-infected infants mounted a response ( > 1.0 mg/L) compared with that in 79% of the HIV-exposed infants (P = .05). Among the HIV-infected infants, there was no difference in the GMTs based on CD4+ cell counts or HIV-related symptoms. After the 15-month booster dose, the GMTs were not significantly different in the HIV-infected and -exposed infants. As a group, the HIV-infected infants responded to the booster dose with a 2-fold increase in the GMTs, and significantly more of these infants had antibody concentrations above 1.0 mg/L compared with their response to the primary series (62% vs 38%, P = .02). CONCLUSIONS: Most of the HIV-infected infants responded to the primary series of Hib conjugate vaccine with antibody concentrations greater than 0.15 mg/L, but the GMTs were significantly lower than those in the uninfected infants. The primary series of Hib conjugate vaccine appeared to be capable of inducing specific immunologic memory in the HIV-infected infants. The HIV-infected infants had a significant response to a booster dose of Hib conjugate vaccine, as measured by using the GMTs and the percentage of infants with antibody concentrations greater than 1.0 mg/L. The duration of protective titers will need to be followed in this population of patients who are at a high risk for serious bacterial disease.

Antibodies, Bacterial↗

PubMed1996

Detection of intravenous fluid extravasation using resistance measurements.

Resistance to fluid infusion can be derived from measurements of pressure at two or more flow rates. We measured resistance in 31 patients using a pressure-monitoring infusion pump (Model 560, IVAC) by recording pressure at five flow rates (0, 50, 100, 200, and 300 mL/hr), and computing resistance as the slope of the pressure versus flow curve. Resistance was measured subcutaneously (Rtissue) and intravenously (Rvein) immediately after unsuccessful or successful IV catheter placement. In all patients, Rtissue was always greater than Rvein. The difference ranged from 23 resistance units (RU) to 4166 RU, with a mean difference of 1147 RU (p < 0.0001, Student's t-test). Unpaired analysis of the data was performed to assess the ability of resistance to indicate extravasation in the absence of prior Rvein measurement. The median value for Rvein was 62 RU (range -13.6 to 420 RU), and for Rtissue, 544 RU (range 65.7 to 4170 RU). Receiver operating characteristic (ROC) analysis revealed that a 200-RU threshold detected infiltration with 0.90 sensitivity and 0.91 specificity. We conclude that elevated resistance during fluid infusion is an important early and easily measurable finding in fluid extravasation.

Extravasation of Diagnostic and Therapeutic Materi↗

PubMed1996

Resistance to fluid flow in veins.

We evaluated the resistance to fluid infusion in the veins of 118 adult patients after intravenous catheter insertion prior to elective surgery. Hydraulic resistance in veins was defined as the slope of the pressure-flow relationship obtained by measuring venous pressure at several fluid flow rates. A resistance unit (RU) was defined as 1 mmHg/L/hr. Resistance in veins ranged from -12.1 to 732 RU, with 50th and 95th percentiles being 22 and 198 RU, respectively. Venous resistance was not significantly affected by site of catheter insertion, tissue characteristics at the insertion site, age, sex, patient anxiety, American Society of Anesthesiologists physical status, or catheter size. This report provides a distribution of resistance to fluid infusion in arm veins of adult patients.

Adult↗

PubMed1996

Vision outcome at age 2 years in a low birth weight population.

We assess the prevalence of vision problems in a cohort of low birth weight infants at age 2 years and the relationship of these problems to neonatal brain injury. Data on prenatal and neonatal history and brain injury status were prospectively collected on 721 children weighing 500-2,000 gm at birth enrolled in a multi-center, population-based longitudinal study. Visual acuity was evaluated using the Teller Acuity Card Procedure. Abnormalities of the eye were assessed by a specially trained pediatric nurse practitioner. Failure of the acuity screen occurred in 62 of 699 tested (8.9%). Multiple logistic regression analysis revealed that the only significant independent predictors of failure included presence of disabling cerebral palsy (DCP) (odds ratio [OR] = 14.8) or nondisabling cerebral palsy (NDCP) (OR = 4.0) and Apgar score of less than 5 at 5 minutes (OR = 2.4). Parenchymal brain injury (PEL) was of borderline significance. Strabismus was present in 123 of 702 children (17.5%). Multiple logistic regression analysis disclosed that the joint predictors of strabismus were presence of DCP (OR = 7.2) and length of hospital stay (OR = 1.6). We conclude that low birth weight infants with parenchymal brain lesions leading to cerebral palsy are at particular risk for vision problems early in life and should be carefully evaluated.

Brain Injuries↗

PubMed1996

Recognition of tubo-ovarian abscess in adolescents with pelvic inflammatory disease.

PURPOSE: Ultrasonography of the pelvis is commonly used to diagnose tubo-ovarian abscess (TOA) in patients with pelvic inflammatory disease (PID). Our objective was to determine whether the clinical features of PID differ in adolescents with and without TOA. METHODS: A retrospective design was used to derive and validate a clinical model differentiating adolescents with PID who did and did not have TOA. The study population consisted of hospitalized adolescents with a discharge diagnosis of PID. Of the 208 patients discharged from January 1, 1990, to July 31, 1993, 87 (42%) met published criteria for PID and comprised the derivation set. Of the 63 patients from August 1, 1993, to June 24, 1994, 30 (48%) met criteria and comprised the validation set. All patients had pelvic ultrasonography performed during hospitalization. The ultrasonography records were reviewed retrospectively for TOA, ovarian and uterine size, clarity of tissue planes, and endometrial or cul-de-sac fluid. Medical records were reviewed for sociodemographic characteristics, medical and sexual history, physical examination, laboratory results, and hospital course. RESULTS: TOA was present in 17% of the derivation set and 20% of the validation set. A six-variable model developed on the derivation set performed best in differentiating the TOA and non-TOA groups: last menstrual period > 18 days prior to admission (60% and 17%), previous PID (53% and 22%), palpable adnexal mass (13% and 3%), white blood cell count > or = 10,500/microliters (33% and 64%), erythrocyte sedimentation rate > 15 mm/h (33% and 64%), and heart rate > 90/min (40% and 78%). In the derivation and validation sets, the model correctly identified 78 and 83% of the TOA groups and 88 and 77% of the non-TOA groups. The area under the receiver operating characteristic curve of the model was 0.92 in the derivation set and 0.87 in the validation set. CONCLUSIONS: We conclude that clinical characteristics help identify adolescents with acute PID who have TOA. These patients may have fewer signs of acute illness than those without TOA and may develop symptoms later in the menstrual cycle.

Abscess↗

PubMed1996

Topical application of lidocaine-prilocaine (EMLA) cream reduces the pain of intramuscular infiltration of saline solution.

OBJECTIVE: Intramuscular injections may be painful. Some of this pain may be caused by the infiltration of medication into the muscle, separate from the pain of skin puncture. We hypothesized that topical application of lidocaine/prilocaine (EMLA) cream would reduce the pain of intramuscular infiltration. METHODS: A double-blinded, placebo-controlled study was performed in 40 adult volunteers to compare the pain of needle puncture and of infiltration of saline into the deltoid muscle after application of EMLA cream or placebo. Each subject served as his or her own control. Pain scores were obtained by using a 100 mm visual analog scale (VAS). RESULTS: Pain associated with needle puncture was significantly reduced by EMLA cream as compared with placebo (median VAS score, 7.5 vs 19.5; p = 0.0043), as was pain associated with intramuscular infiltration (median VAS score, 2.5 vs 11; p < 0.00005). CONCLUSIONS: Our results suggest that further clinical studies of EMLA cream for modifying perceived pain from intramuscular injection in children are warranted.

Administration, Cutaneous↗