OBJECTIVE: To design, implement, and study the effectiveness of 4 new critical pathways relevant to head and neck oncological care. DESIGN: Before-after trial. SETTING: Tertiary referral academic institution. PATIENTS: Sixty-eight patients admitted for head and neck oncological surgery or chemotherapy from December 1, 1995, through May 31, 1996; 30 patients with similar diagnoses and who underwent surgical procedures from December 1, 1994, to December 1, 1995, who served as historical controls. INTERVENTIONS: Implementation of 4 critical pathways: chemotherapy, clean head and neck surgery, clean contaminated head and neck surgery, clean contaminated head and neck surgery with reconstructive flap. MAIN OUTCOME MEASURES: Length of stay, cost of hospitalization, and variance tracking (deviations from established standards). RESULTS: The length of stay for the clean contaminated group without flap reconstruction decreased by 1.5 days, and costs decreased by $7407 per patient (P < .05, Student t test). The length of stay decreased 1.6 days in the clean contaminated group with flap reconstruction, and costs decreased $9845 per patient (P < .05, Student t test). Nine patients (13%) experienced a prolonged length of stay while on a critical pathway. CONCLUSIONS: Implementation of critical pathways has resulted in a decreased overall length of stay and cost of hospitalization. It has also allowed for better coordination and documentation of patient care, while the tracking of variances has simplified problem identification and correction.

Critical Pathways↗

PubMed1997

Border controls at the mammalian spinal cord: late-surviving neural crest boundary cap cells at dorsal root entry sites may regulate sensory afferent ingrowth and entry zone morphogenesis.

Boundary caps (BCs) form when neural crest cells, migrating ventrally alongside the neural tube, arrest at sites where axons will enter and exit. However, nothing is known of their subsequent fate and functions. We have found late-surviving neural crest BC cell clusters at proximal dorsal root entry sites throughout rat spinal cord development. Sensory afferents cross BCs to enter the spinal cord, while exiting astrocyte processes, destined to form the dorsal root entry zone (DREZ) after birth, are temporarily stalled in their vicinity. To test whether contact with BC cells influences neurite outgrowth from dorsal root ganglia, neurons were cultured on embryonic dorsal root/spinal cord cryosections. Neurites that entered CNS territory preferentially extended over BC cells. Thus, BC cells could be instrumental in regulating afferent ingrowth and DREZ morphogenesis in mammalian spinal cord development.

Animals↗

PubMed1997

Soluble CD16/Fc gamma RIII induces maturation of dendritic cells and production of several cytokines including IL-12.

Fc gamma RIII (CD16), a low affinity FcR which binds IgG-containing immune-complexes, exists under membrane-associated forms and under a soluble form (sFc gamma RIII). The latter, present in biological fluids (serum, saliva), is generated by proteolytic cleavage of the two membrane-associated Fc gamma RIII isoforms, Fc gamma RIII-A (expressed by macrophages and NK cells) and Fc gamma RIII-B (expressed exclusively by neutrophils). Herein we demonstrate that dendritic cells (DCs), generated by culturing monocytes with GM-CSF and IL-4, bind biotinylated recombinant sFc gamma RIII. This binding is specific and involves the complement receptor CR3 (CD11b/CD18) and CR4 (CD11c/CD18). Indeed, preincubation of DCs with anti-CD11b and anti-CD11c mAbs decreased by 52% and 62% respectively the binding with sFc gamma RIII. Moreover, electron microscopy showed that binding of gold-labeled sFc gamma RIII to DCs maintained at 4 degrees C occurred within clathrin-coated pits. Once internalized, at 37 degrees C, sFc gamma RIII entered the endocytic pathway and reached the MHC class II compartments. Furthermore, DCs incubated for 48 h with multivalent sFc gamma RIII expressed increased levels of CD40, CD80, CD86, CD54, CD58, HLA class I and class II molecules and decreased levels of CD23 and CD32. These effects result in an increased capacity of DCs to trigger proliferative responses by CD4+ CD45RA+ allogeneic T cells. RT-PCR amplification demonstrated that incubation of DCs for 20 h in the presence of multivalent sFc gamma RIII induced the appearance of GM-CSF and IL-12 p40 mRNA. Among the cytokines constitutively expressed, IL-1 beta and IL-8 were strongly up-regulated whereas IL-6 and IL-12 p35 mRNA were increased to a lesser extent and the expression of MIP-1 alpha mRNA remained constant. Finally, ELISA tests demonstrated that DCs incubated with multivalent sFc gamma RIII secreted the cytokines IL-1 beta, IL-6, IL-8, GM-CSF and IL-12 p75. Thus, while becoming internalized sFc gamma RIII could affect the capacity of DCs to present antigens and, via the induction of accessory molecules and the release of the IL-12 p75 protein, could initiate Th1 type immune response.

Antigen Presentation↗

PubMed1997

Right ventricular dysfunction persists following brief right ventricular pressure overload.

OBJECTIVE: Acute pulmonary hypertension may cause right ventricular (RV) contractile failure. While it has been assumed that restoration of normal loading conditions after acute pulmonary hypertension is sufficient for complete recovery of RV function, this has not been rigorously examined. The purpose of this study was to test the hypothesis that acute RV pressure overload produces RV contractile dysfunction that persists following restoration of control loading conditions. METHODS: We subjected 18 autonomically-blocked, chloralose-anesthetized, open-chest pigs to 1 h of pulmonary artery constriction to increase RV systolic pressure from 35 +/- 1 to 55 +/- 1 mmHg, followed by 2 h of measurements after pulmonary artery constriction release. We determined regional RV free wall function from pressure-segment length loops and preload recruitable stroke work relations, and global RV function from stroke work vs. end-diastolic pressure relations. RESULTS: As expected, RV free wall systolic shortening diminished during pulmonary artery constriction, but the endo/epi blood flow ratio, lactate uptake, and coronary venous pH were not significantly changed. Following release of pulmonary artery constriction, RV systolic and diastolic pressure returned to control values. Nonetheless, contractile dysfunction persisted, with depressed RV free wall systolic shortening (70 +/- 22% of control), RV regional external work (59 +/- 11% of control at control end-diastolic length), and global RV stroke work (56 +/- 14% of control at control end-diastolic pressure). Depressed regional work was due to a parallel, rightward shift of the preload recruitable stroke work relation. Five pigs identically instrumented but not subjected to pulmonary artery constriction showed no significant over 3 h. CONCLUSIONS: Acute pulmonary hypertension causes RV contractile dysfunction that persists at least 2 h after restoration of control loading conditions. Contractile dysfunction is not attributable to RV ischemia during pressure overload.

Acute Disease↗

PubMed1997

A prospective study of the repeated use of sterilized papillotomes and retrieval baskets for ERCP: quality and cost analysis.

BACKGROUND: The impact on instrument quality and cost of the practice of reusing ERCP accessories has not been fully addressed. METHODS: Twenty-five new papillotomes and 15 new retrieval baskets were labeled and evaluated over time by staff blinded to the number of prior uses. Instruments were scored as to their function for the designated task. The cost of this practice was calculated from the purchase price of accessories and the costs of cleaning, sterilization, and disposal, and then compared with the estimated cost of a practice of one-time use of similar instruments. RESULTS: Twenty-five papillotomes were used 246 times (median 8; mean 9.8). Fifteen retrieval baskets were used 193 times (median 13; mean 12.9). The median survival of both papillotomes and baskets before being considered inadequate (score < 6 out of 10) was 9 uses. There were no complications attributable to using reused equipment. The projected yearly cost savings of using reusable versus disposable instruments was $94,095 for papillotomes and $61,809 for baskets, a 475% and 322% cost reduction, respectively. CONCLUSION: The papillotomes and baskets in this study could be reused reliably and safely multiple times, with considerable cost savings compared with the practice of using disposable instruments.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMed1997

Maturation of the mammalian dorsal root entry zone--from entry to no entry.

Interfaces between glial cell precursors of the PNS and CNS are established early in development and form the sites where sensory axons enter and motor axons exit the developing CNS. The molecular and cellular interactions that lead to the formation of these glial interfaces are only now becoming apparent. New in-vitro techniques are providing clues as to how the maturation of PNS-CNS glial interfaces generates barriers to regenerating axons.

Aging↗

PubMed1997

On the number of trials needed for P300.

The P300 event-related brain potential (ERP) was elicited in n = 24 subjects using auditory and visual stimuli with target probabilities of 0.20 and 0.80 in different conditions. A total of 40 target stimulus ERPs were obtained from each subject and were averaged in two different ways: (1) single-trial averages were obtained by averaging each subsequent pairs of trial blocks (1-2, 3-4, 5-6, etc); (2) successive averages were obtained by averaging successive blocks of two trials (1-2, 1-4, 1-6, etc.). Statistical analyses demonstrated that for the single-trial averages, P300 measures are variable but not significantly different from one another across trial pairs, whereas successive averages demonstrated systematic decreases in amplitude and slight increases in peak latency. Auditory and visual stimuli produced similar patterns for the two averaging methods, as did target probability. The findings suggest that P300 amplitude stabilized with approximately 20 target trials for all conditions, and that peak latency changes relatively little during this time. The results are discussed in terms of applied/clinical contexts.

Acoustic Stimulation↗

PubMed1997

Acute beriberi following liver transplantation.

Patients scheduled for orthotopic liver transplantation (OLT) undergo extensive routine preoperative cardiac assessment. We describe a 32-year-old male who underwent uneventful OLT for endstage liver failure on the basis of chronic hepatitis C and alcoholism. Despite a normal preoperative cardiac workup, the patient developed acute pulmonary edema on the second postoperative day. A diagnosis of beriberi was entertained and confirmed by (1) the thiamine diphosphate effect and (2) the dramatic response to intravenous thiamine. Possible precipitating factors are described. Thiamine, which has no significant toxicity, should probably be routinely supplemented in all patients undergoing OLT, especially those with a previous history of alcohol abuse.

Journal Article↗