Delay of extubation in neonates and children after cardiac surgery: impact of ventilator-associated pneumonia

OBJECTIVE

This study was undertaken to determine the delay of extubation attributable to ventilator-associated pneumonia (VAP) in comparison to other complications and complexity of surgery after repair of congenital heart lesions in neonates and children.

METHODS

Cohort study in a pediatric intensive care unit of a tertiary referral center. All patients who had cardiac operations during a 22-month period and who survived surgery were eligible (n = 272, median age 1.3 years). Primary outcome was time to successful extubation. Primary variable of interest was VAP Surgical procedures were classified according to complexity. Cox proportional hazards models were calculated to adjust for confounding. Potential confounders comprised other known risk factors for delayed extubation.

RESULTS

Median time to extubation was 3 days. VAP occurred in 26 patients (9.6%). The rate of VAP was not associated with complexity of surgery (P = 0.22), or cardiopulmonary bypass (P = 0.23). The adjusted analysis revealed as further factors associated with delayed extubation: other respiratory complications (n = 28, chylothorax, airway stenosis, diaphragm paresis), prolonged inotropic support (n = 48, 17.6%), and the need for secondary surgery (n = 51, 18.8%; e.g., re-operation, secondary closure of thorax). Older age promoted early extubation. The median delay of extubation attributable to VAP was 3.7 days (hazards ratio HR = 0.29, 95% CI 0.18-0.49), exceeding the effect size of secondary surgery (HR = 0.48) and other respiratory complications (HR = 0.50).

CONCLUSION

VAP accounts for a major delay of extubation in pediatric cardiac surgery.

Prospective trial of preoperative concomitant boost radiotherapy with continuous infusion 5-fluorouracil for locally advanced rectal cancer

RATIONALE

To evaluate the response to a concomitant boost given during standard chemoradiation for locally advanced rectal cancer.

METHODS AND MATERIALS

Concomitant boost radiotherapy was administered preoperatively to 45 patients with locally advanced rectal cancer in a prospective trial. Treatment consisted of 45 Gy to the pelvis with 18 mV photons at 1.8 Gy/fraction using a 3-field belly board technique with continuous infusion 5FU chemotherapy (300mg/m(2)) 5 days per week. The boost was given during the last week of therapy with a 6-hour inter-fraction interval to the tumor plus a 2-3 cm margin. The boost dose equaled 7.5 Gy/5 fractions (1.5 Gy/fraction); a total dose of 52.5 Gy/5 weeks was given to the primary tumor. Pretreatment tumor stage, determined by endorectal ultrasound and CT scan, included 29 with T3N0 [64%], 11 T3N1, 1 T3Nx, 2 T4N0, 1 T4N3, and 1 with TxN1 disease. Mean distance from the anal verge was 5 cm (range 0-13 cm). Median age was 55 years (range 33-77 years). The population consisted of 34 males and 11 females. Median time of follow-up is 8 months (range 1-24 months).

RESULTS

Sphincter preservation (SP) has been accomplished in 33 of 42 (79%) patients resected to date. Three patients did not undergo resection because of the development of metastatic disease in the interim between the completion of chemoradiation (CTX/XRT) and preoperative evaluation. The surgical procedures included proctectomy and coloanal anastomosis (n = 16), low anterior resection (n = 13), transanal resection (n = 4). Tumor down-staging was pathologically confirmed in 36 of the 42 (86%) resected patients, and 13 (31%) achieved a pathologic CR. Among the 28 tumors (67%) located <6 cm from the anal verge, SP was accomplished in 21 cases (75%). Although perioperative morbidity was higher, toxicity rates during CTX/XRT were comparable to that seen with conventional fractionation. Compared to our contemporary experience with conventional CTX/XRT (45Gy; 1.8 Gy per fraction), improvements were seen in SP (79% vs. 59%; p = 0.02), SP for tumors <6 cm from the anal verge (75% vs. 42%; p = 0.003), and down-staging (86% vs. 62%; p = 0.003).

CONCLUSION

The SP rate with concomitant boost radiation has been highly favorable with rates of response which are higher than those previously reported for chemoradiation without administration of a boost. Further evaluation of this radiotherapeutic strategy appears warranted.

Inter-ethnic differences in youth tobacco language and cigarette brand preferences

OBJECTIVE

To describe and understand variations in cigarette brand preferences between adolescents from varying ethnic and gender groups around the US.

DESIGN

A qualitative study where adolescents, both smokers and nonsmokers, were interviewed individually in depth.

SETTING

Schools and recreation centers in four sites: urban Maryland (Baltimore), urban Texas (Houston), rural Alabama and rural New Mexico.

PARTICIPANTS

121 adolescent volunteers 13-19 years of age, representing African American, white, American Indian and Hispanic ethnic groups, from both genders.

RESULTS

Considerable geographic and ethnic variation exists in terminology used by youth to refer to cigarettes and to their use. Clear patterns in brand preference by ethnic group were found that follow patterns of targeted marketing by ethnicity. White teens preferred Marlboro brand cigarettes, while African-American teens who smoke preferred Newports. Hispanic and American Indian teens were more likely to smoke Marlboro or Camel cigarettes. Hispanic teens were most likely to mention low price as a reason for choosing a particular brand or to state that the brand does not matter. Tobacco advertisements targeting ethnic groups and the use of promotional items to encourage teen smoking were also recognized as factors influencing brand preferences.

CONCLUSIONS

These findings have implications for the design of intervention programs aimed at curbing teen smoking. When working with teens who already smoke, using youth language to target messages at perceived characteristics of commonly used brands may be more effective and meaningful than talking about cigarette use in general. Another implication of this work is to shed light on what impact an advertising ban would have on teen brand preferences, brand loyalty, and prevalence of smoking.

Taking a first puff: cigarette smoking experiences among ethnically diverse adolescents

OBJECTIVES

To study the social contexts and physiological consequences of an initial cigarette smoking experience among adolescents from four ethnic groups (African American, European American, Hispanic, Native American) who vary by gender and locale (e.g. urban vs rural).

METHOD

A qualitative study using individual interviews and focus groups.

RESULTS

Results both amplify and reinforce conclusions about peer and family influences on adolescent smoking initiation reported in quantitative studies of teen smoking. Within the broader themes of peers and family, several important sub-themes emerged. The study findings suggest that peer influence can be characterized as social conformity or social acceptance. Males were more likely than females to describe experiences involving peers exerting strong messages to conform to smoking behaviors. Roles played by family members in the initiation process were complex and included those of initiator, prompter, accomplice, and inadvertent source of cigarettes. European American and Hispanic girls provided descriptions of parents/family members as instigators of their first smoking experience. Hispanic adolescents descripted instances in which family members prompted cigarette use at a young age by encouraging the young person to light the adult's cigarette. Finally, ethnic differences in the physiological responses to initial smoking suggest the need to further explore the role of brand preference and variations in inhaling among ethnically diverse adolescents.

CONCLUSION

In order to design effective cigarette smoking prevention programs for adolescents, it is important to understand the meaning of smoking behaviors for adolescents from different ethnic and social backgrounds.

Herpes simplex virus (HSV)-mediated ICAM-1 gene transfer abrogates tumorigenicity and induces anti-tumor immunity

BACKGROUND

Costimulatory and cellular adhesion molecules are thought to be essential components of antigen presentation in the immune response to cancer. The current studies examine gene transfer utilizing herpes viral amplicon vectors (HSV) to direct surface expression of adhesion molecules, and specifically evaluate the potential of a tumor-expressing intercellular adhesion molecule-1 (ICAM-1) to elicit an anti-tumor response.

MATERIALS AND METHODS

The human ICAM-1 (hICAM1) gene was inserted into an HSV amplicon vector and tested in a transplantable rat hepatocellular carcinoma and in a human colorectal cancer cell line. Cell surface ICAM-1 expression was assessed by flow cytometry. Lymphocyte binding to HSV-hICAM1-transduced cells was compared with that to cells transduced with HSV not carrying the ICAM gene. Tumorigenicity of HSV-hICAM1-transduced tumor cells were tested in syngeneic Buffalo rats. Additionally, immunization with irradiated (10,000 rads) HSV-hICAM1-transduced tumor cells was performed to determine its effect on tumor growth.

RESULTS

A 20-min exposure of tumor cells at a multiplicity of infection (MOI) of 1 resulted in high-level cell surface expression of human ICAM in approximately 25% of tumor cells. Transduced rat or human tumor cells exhibited significantly enhanced binding of lymphocytes (p < 0.05). HSV-hICAM1-transduced cells elicited an increase in infiltration by CD4(+) lymphocytes in vivo and exhibited decreased tumorigenicity. Immunization with irradiated HSV-hICAM1-transduced cells protected against growth of subsequent injected parental tumor cells.

CONCLUSIONS

HSV amplicon-mediated gene transfer is an efficient method for modifying the cell surface expression of adhesion molecules. Increased tumor expression of ICAM-1 represents a promising immune anti-cancer strategy.

Role of radiotherapy in sarcoma of the breast--a retrospective review of the M.D. Anderson experience

BACKGROUND

The role of adjuvant radiotherapy for sarcoma of the breast, based on local extension of disease and patterns of failure, remains undefined because of the rarity of the disease presentation.

METHODS

Fifty-nine cases of soft tissue sarcoma of the breast were retrospectively reviewed. Cystosarcoma phylloides was excluded from analysis. Surgical intervention consisted of segmental resection (n = 16) or mastectomy (n = 38); five patients underwent excisional biopsy. Adjuvant radiotherapy was administered in four patients following segmental resection and in 13 patients after mastectomy. Doses totaled 50 Gy in the majority of patients, and conventional criteria and radiotherapy techniques for adjuvant breast irradiation were used.

RESULTS

None of the dissected axillary nodes contained metastatic tumor on pathologic review. Patterns of failure were evaluated. Tumor size (P < 0.03) and surgical margins (P < 0.002) were predictive of local failure (LF). Due to limited patient numbers, no statistical significance was identified with any treatment modality. Following mastectomy alone, LF occurred in 13 patients (34%) versus the 13% rate of LF with mastectomy and radiotherapy (P = NS). Distant metastases developed concurrently with the two local failures in the group that underwent mastectomy and radiation. After segmental mastectomy, LF occurred in 3 cases (25%) concurrent with distant metastases: no LF were noted after segmental mastectomy and radiation (P = 0.27). For all treatment groups, local recurrences were characterized as multiple and involved the chest wall. Local failure occurred in 60% of patients with positive surgical margins who did not receive adjuvant irradiation. Irrespective of surgical margins, over 75% of local recurrences developed among patients treated by surgery alone.

CONCLUSIONS

The role of radiotherapy for breast sarcoma remains undefined due to the rarity of this disease presentation. This retrospective review failed to demonstrate a statistical benefit for the administration of adjuvant irradiation in sarcoma of the breast, probably because of limited patient numbers. Because large tumor size and positive surgical margins incur a higher risk for LF, radiotherapy is probably indicated in these cases. Axillary dissection obligates the radiotherapist to treat the axilla in order to include all tissues in the surgical bed, and should be avoided to reduce potential treatment related morbidity. Established therapeutic principles and techniques used for both soft tissue sarcoma and breast cancer should continue to be applied.

Effectiveness of accelerated radiotherapy for patients with inoperable non-small cell lung cancer (NSCLC) and borderline prognostic factors without distant metastasis: a retrospective review

PURPOSE

The standard treatment for patients with unresectable or medically inoperable non-small cell lung cancer (NSCLC) and good prognostic factors (e.g., weight loss [WL] < or = 5% and Karnofsky performance status [KPS] > or = 70) is induction chemotherapy followed by definitive radiotherapy to the primary site at 1.8-2.0 Gy per fraction with a total dose of 60-63 Gy to the target volume. Patients with poor prognostic factors usually receive radiotherapy alone, but the fractionation schedule and total dose have not been standardized. To attempt to optimize irradiation doses and schedule, we compared the effectiveness of accelerated radiotherapy (ACRT) alone to 45 Gy at 3 Gy per fraction with standard radiation therapy (STRT) of 60-66 Gy at 2 Gy per fraction in regard to tumor response, local control, distant metastasis, toxicity, and survival.

METHODS AND MATERIALS

Fifty-five patients treated with radiation for NSCLC at The University of Texas M. D. Anderson Cancer Center between 1990 and 1994 were identified. All 55 patients had node-positive, and no distant metastasis (N+, M0) of NSCLC. Two cohorts were identified. One cohort (26 patients) had borderline poor prognostic factors (KPS less than 70 but higher than 50, and/or WL of more than 5%) and was treated with radiotherapy alone to 45 Gy over 3 weeks at 3 Gy/fraction (ACRT). The second cohort (29 patients) had significantly better prognostic factors (KPS > or = 70 and WL < or = 5%) and was treated to 60-66 Gy over 6 to 6 1/2 weeks at 2 Gy per fraction (STRT) during the same period.

RESULTS

In the first cohort treated by ACRT, the distribution of patients by AJCC stage was IIB 8%, IIIA 19%, and IIIB 73%. Sixty-two percent had KPS <70, and 76% had a WL of >5%. The maximum response rate as determined by chest X-ray was 60% among 45 of 55 patients who were evaluable for response: combined complete responses (20%) and partial responses (40%). Overall survival in these patients was 13% at 2 and 5 years, with a locoregional control rate of 42% and a freedom from distant metastasis rate of 54%. The ACRT cohort treated with 3 Gy per fraction had significantly lower KPS scores (p = 0.003) and greater WL (p = 0.063) than the cohort STRT treated with 2 Gy per fraction. However, treatment results and toxicity were not significantly different between the two cohorts in spite of significantly better prognostic factors in the STRT cohort.

CONCLUSIONS

Despite having worse prognostic factors, the cohort treated with radiotherapy alone to 45 Gy at 3 Gy per fraction over 3 weeks (ACRT) had response rates, locoregional control, and overall survival comparable to those in the cohort treated by a total dose of 60-66 Gy at 2 Gy per fraction over 6 to 6 1/2 weeks (STRT). Given that accelerated treatment schedules decrease treatment time and cost less, these may, in the current health care environment, be important factors for health care providers to consider in treating patients who have locally advanced NSCLC and borderline poor prognostic factors.

The optimum time to initiate habitual xylitol gum-chewing for obtaining long-term caries prevention

Habitual xylitol gum-chewing may have a long-term preventive effect by reducing the caries risk for several years after the habitual chewing has ended. The goal of this report was (1) to determine if sorbitol and sorbitol/xylitol mixtures provide a long-term benefit, and (2) to determine which teeth benefit most from two-year habitual gum-chewing - those erupting before, during, or after habitual gum-chewing. Children, on average 6 years old, chewed gums sweetened with xylitol, sorbitol, or xylitol/sorbitol mixtures. There was a "no-gum" control group. Five years after the two-year program of habitual gum-chewing ended, 288 children were re-examined. Compared with the no-gum group, sorbitol gums had no significant long-term effect (relative risk [RR], 0.65; 95% confidence interval [c.i.], 0.39 to 1.07; p < 0.18). Xylitol gum and, to a lesser extent, xylitol/sorbitol gum had a long-term preventive effect. During the 5 years after habitual gum-chewing ended, xylitol gums reduced the caries risk 59% (RR, 0.41; 95% c.i., 0.23 to 0.75; p < 0.0034). Xylitol-sorbitol gums reduced the caries risk 44% (RR, 0.56; 95% c.i., 0.36 to 0.89; p < 0.02). The long-term caries risk reduction associated with xylitol strongly depended on when teeth erupted (p < 0.02). Teeth that erupted after 1 year of gum-chewing or after the two-year habitual gum use ended had long-term caries risk reductions of 93% (p < 0.0054) and 88% (p < 0.0004), respectively. Teeth that erupted before the gum-chewing started had no significant long-term prevention (p < 0.30). We concluded that for long-term caries-preventive effects to be maximized, habitual xylitol gum-chewing should be started at least one year before permanent teeth erupt.

Community partnerships in nursing education

A community partnership for a seamless education process is explored. Mechanisms for program delivery to a distance education site such as: the use of interactive video-conferencing, student support services, and changing faculty roles are reviewed. Positive outcomes of the community partnership have developed for both the community college and the participating university.

Difficult or incomplete flexible sigmoidoscopy: implications for a screening programme

BACKGROUND

Pilot studies are currently underway to investigate the use of flexible sigmoidoscopy as a screening tool for colorectal cancer. Estimates of the sensitivity of this investigation in detecting adenomas and carcinomas frequently assume a complete examination to 60 cm in all cases. This study seeks to determine the depth of insertion of flexible sigmoidoscopy in asymptomatic volunteers, and to examine the causes and implications of an incomplete examination.

METHODS

A prospective study of flexible sigmoidoscopy in asymptomatic volunteers was conducted. The maximum depth of insertion was measured in all cases, and a database compiled of patient characteristics, discomfort and endoscopic difficulty.

RESULTS

Independent risk factors for reduced depth of insertion were female sex, previous abdominal surgery in females, high expectation of pain in females and poor bowel preparation. The procedure was considered difficult in 33% of cases.

CONCLUSIONS

Estimates of the efficacy of flexible sigmoidoscopy as a colorectal cancer screening modality should take into account the relatively high rate of incomplete studies, particularly in women.

Effects of perindopril on renal histomorphometry in diabetic subjects with microalbuminuria: a 3-year placebo-controlled biopsy study

We conducted a 3-year randomized placebo-controlled double-blind study to determine the effects of the angiotensin-converting enzyme (ACE) inhibitor perindopril (PE) on the progress of renal function and histology in subjects with diabetes and microalbuminuria. Forty non-insulin-dependent (NIDDM) and insulin-dependent (IDDM) diabetic subjects, either normotensive or hypertensive, were randomly assigned to receive PE (n = 20) or placebo (n = 20). A percutaneous renal biopsy was performed initially in all patients and repeated in 29 patients after 3 years. The mean glomerular volume, glomerular basement membrane (GBM) thickness, interstitial fibrosis, sclerosed glomeruli, and volume fraction of capillary lumina were measured histomorphometrically. Before treatment, both groups had similar clinical characteristics, blood pressure, glycosylated hemoglobin (Hb), albumin excretion rate, glomerular filtration rate (GFR), serum creatinine, and renal structural damage. Blood pressure was well controlled in both groups. After 3 years' therapy, there was no significant change in renal function and albuminuria in the PE or placebo groups. The increase in GBM thickness in nine paired biopsies was significantly less in PE-treated subjects (P = .0275). Interstitial fibrosis tended to increase less in the PE group, although this did not reach statistical significance. This study indicates that long-term therapy with PE may decrease or delay the progression of structural glomerular damage in microalbuminuric diabetic subjects.

The role of level, spectral, and temporal cues in children's detection of masked signals

Preschool-aged children and adults were asked to detect masked signals in four conditions that evaluated the role of level, spectral, and temporal cues on performance. Psychometric functions fitted to percent correct data at several signal-to-noise ratios showed higher thresholds and shallower slopes for the children in all conditions. Performance was similar in fixed and roving level conditions for both age groups suggesting use of level-invariant cues. When the signal was moved to the spectral edge of the masker the performance of the adults improved but that of the children did not. This suggested that children did not benefit from the additional cues provided by the off-center signal. Children's performance worsened when the signal was a narrow-band noise rather than a pure tone but the adults' did not, suggesting children's reliance on temporal changes in the masker with the introduction of the signal. Analyses of the stimuli suggested that the children's thresholds corresponded to signal-to-noise ratios at which multiple cues were present at magnitudes that were great enough to be discriminable.