Missed opportunities for identifying primary HIV within genitourinary medical/HIV services

To assess the ability of three genitourinary medical centres to clinically identify primary HIV infection (PHI). Cases of recently acquired HIV infection, identified using the Health Protection Agency (HPA) avidity assay on all HIV diagnoses from January to August 2009, were investigated by case-note review. Sixty-four individuals were identified as PHI using the HPA avidity assay. Of 64 individuals, 31 (48%) were identified clinically. Imperial College identified 8/26 (31%), Guys and St Thomas' 15/27 (56%) and Brighton 8/11 (73%). Clinical suspicion of PHI was associated with reported unprotected anal intercourse (P = 0.017), seroconversion symptoms (P = 0.0004), a negative HIV test within six months (P = 0.024) and avidity assay result availability (P = 0.0169). Seventy percent of PHI cases missed had a documented risk factor. Thirty-five percent of those clinically identified with PHI were documented as informed of the associated enhanced infectivity. Suspicion of PHI was low despite documented risk factors and recent HIV-negative antibody tests. Counselling to prevent onward transmission was suboptimal.

Microwave Processing at the University of Florida

Microwave energy for processing materials is emerging as a vital manufacturing technology for the nineties and beyond. Research to date has shown significant advantages in several areas, including drying and sintering, joining, surface modification and waste remediation. Increased processing rates, improved physical and mechanical properties and, in some cases, reduced hazardous emissions have sparked the interest of many manufacturers in the ability to integrate microwave processing techniques into existing and future manufacturing operations. This presentation will provide an overview of the microwave processing research and development work in progress at the University of Florida.

A randomized pilot study comparing aprepitant to olanzapine for treatment of chemotherapy-induced nausea and vomiting

9633

Background: Chemotherapy-induced nausea and vomiting (CINV) in patients receiving highly emetogenic chemotherapy (HEC) is prevalent. The NK1antagonist, aprepitant (APR), has been shown to decrease CINV and with increased use, cost of supportive care is rising. Recent studies have shown that olanzapine (OLN) is safe and effective for CINV when used in combination with dexamethasone and palonosetron. We conducted a randomized, double-blind, placebo controlled pilot study to evaluate the use of OLN compared to APR for prevention of CINV in patients receiving HEC. Methods: Chemotherapy naïve patients receiving HEC were randomized to an APR containing arm or an OLN containing arm [see Table ] for the first 2 cycles of treatment. Patients recorded episodes of emesis and use of rescue meds using a daily diary and symptoms using the M.D. Anderson Symptom Inventory(MDASI). 18 patients consented to the protocol and 17/18 (OLN=8, APR=9) patients were evaluable (1 lost daily diary) with a median age 60 (range 24–71) 11/18 were females. Results: Chemo regimens for OLN group included (AC=50%, cisplatin=25%, ABVD=25%, and ifos=25%) and for APR (AC=55%, cisplatin=33%, and ABVD=11%) For both cycles (C1+C2) the complete response (CR=no emesis, no rescue) during the anticipatory period (D-2, D-1) was 87.5% in the OLN group compared to 77.8% in the APR group. Acute period (D1) CR rates were 75% in OLN vs. 44% in the APR group. Delayed (D2–4) CR rates were 62.5% in OLN vs. 55.6% in the APR group. Rates of nausea (score ≥ 1 on scale of 0–10, MDASI) were 25% OLN vs. 22.2% APR for anticipatory period, 62.5% OLN vs. 44.4% APR for acute period, and 62.5% OLN vs. 66.7% APR for delayed period. There were no grade 3 /4 toxicities. Conclusions: OLN containing antiemetic regimens were well tolerated and offered similar efficacy as APR containing regimens in preventing CINV in patients receiving HEC. Larger studies are needed to evaluate non-inferiority and potential cost savings of OLN containing regimens. [Table: see text]

No significant financial relationships to disclose.

Phase I study of the effects of hepatic impairment on the pharmacokinetic (PK) and safety of satraplatin in patients with refractory non-hematologic cancer

2045

Background: Satraplatin (S) is a third-generation oral platinum analog that has demonstrated activity in the treatment of patients with platinum-sensitive malignancies. A worldwide double-blind, placebo controlled randomized phase III trial evaluating S as 2nd line therapy for HRPC has recently completed enrollment. The current study was designed to determine the effect of hepatic impairment on S pharmacokinetics in patients with refractory cancer, as well as treatment efficacy and toxicity. Methods: S was administered orally at a dose of 80mg/m2/day (d) on d1–5 every 35 days. Study groups (cohorts) were defined at 4 levels of hepatic impairment - Group 1 (G1) = control; G2 = Child-Pugh Class A; G3 = Child-Pugh Class B; and Group 4 = Child-Pugh Class C. Results: 19 pts have been enrolled to date (11 M/ 8 F); median age is 57 (range 44–80). Pts with prostate (2), pancreas (4), colorectal (3), adenocystic (2), and 1 each neuroendocrine, hepatocellular, melanoma, breast, ovarian, SCLC, and anal cancers were enrolled. 8 pts were in G1, 3 pts in G2, 4 pts in G3, and 5 pts in G4. Accrual is ongoing in this study with a total of 8 pts planned for each group. The median number of prior regimens was 5 (range 2–8). A total of 35 cycles of S have been given: median 2/pt (range 1–4). 9 pts have completed 2 cycles of S. Hematologic toxicities during the first 2 cycles included grade (G) 3/4 thrombocytopenia in 15 %. There were no cases of G 3/4 neutropenia or anemia. One case of G3 hypokalemia, was reported. Two patients developed acute renal failure; one of which was due to uncontrolled nausea (N) and vomiting (V) and the other was associated with rapid disease progression in the liver. Both were G4 patients. Otherwise, N, V, and diarrhea were mild to moderate, and controlled with oral therapy. Conclusions: S is, in general, well tolerated in patients with mild or moderate liver impairment. Severe thrombocytopenia is the most common side-effect. Of the patients enrolled to date 15% did not have progression of disease. PK data will also be presented.

[Table: see text]

A method to determine when active translocation of nonhuman primates is justified

This article addresses translocation, or artificial dispersal, the movement of one or more organisms from one location to another, and focuses on the decisions to be made before translocation begins. Scientific, economic, or pragmatic reasons such as pest removal or conservation of biodiversity may account for undertaking translocation. When is translocation ethical, and how can that decision be determined? This article provides one quantitative and utilitarian method for evaluating these questions. Although this analysis may apply to any nonhuman species for which costs and benefits can be assessed, the examples in this article derive from the nonhuman primate literature.

Lessons about sleepiness and driving from the Selby rail disaster case: R v Gary Neil Hart

In April 2003, near the town of Selby in North Yorkshire, England, a motor vehicle went off the road to cause a train collision, killing 10 and injuring more than 70 people. The driver of the vehicle, Gary Neil Hart, had allegedly fallen asleep while driving, and was charged and subsequently convicted of causing death by dangerous driving. Evidence from an expert witness was led by the prosecution to establish that Hart had in fact fallen asleep, and that prior to falling asleep, he knew (or ought to have known) that he was at risk of falling asleep but nevertheless continued to drive. The issue of whether and to what extent individuals are aware that they are about to fall asleep has significant implications for criminal prosecutions. Generally, the definition of a criminal offense includes a mental element such as intent or knowledge. Therefore, it is imperative that issues such as whether in every individual there is forewarning of sleep and the degree to which individuals are able to self-assess their ability to continue driving under conditions of extreme sleepiness must be resolved. Sleepiness is now regarded as the largest identifiable and preventable cause of accidents in all modes of transportation. Litigation for such accidents is likely to increase, and therefore it is of great importance that further research be undertaken to examine the process of falling asleep, especially the subjective experiences immediately preceding sleep.

Surgical treatment of olecranon fractures

Fractures of the olecranon are common injuries with no single accepted treatment. Numerous clinical factors and biomechanical studies guide the surgeon in determining a treatment plan. The goals of surgical management include anatomical reduction and stable fixation, which allow early range of motion of the elbow joint. Numerous fixation methods have been described and include screw fixation, cerclage wiring, modified tension-band wiring, and plate fixation. The surgical technique depends on a combination of patient factors, the fracture pattern, and the mechanical stability of the fixation construct. Postoperative rehabilitation includes early active range-of-motion exercises and follows clinical and radiographic healing. Complications are related to the fracture, choice of implant, and surgical technique.

Building health services research capacity in nursing: views from members of nursing's leadership [interview by Candice Cook Bowman and Deborah Gardner]

BACKGROUND

Despite a short history that dates back to the 1960s, health services research (HSR) has become an important force in shaping the delivery system in the current health care environment. Nursing has been noticeably absent from this endeavor, and if it does not increase its presence, it risks missing an important opportunity to influence future directions of health care delivery.

PURPOSE

Our purpose was to evaluate the state of nursing's HSR contributions and to consider ways to increase its capacity in this arena.

METHOD

An interview with four members from nursing's leadership was conducted.

DISCUSSION

Nurses can increase the capacity by becoming better collaborators with those who are currently contributing to HSR, both nurses and members of other healthcare disciplines. Also, by reshaping undergraduate and graduate curricula and creating mentorships, nursing can increase its involvement through an informed workforce.

CONCLUSIONS

Solutions that were offered in this discussion are presented.

Percutaneous stabilization of U-shaped sacral fractures using iliosacral screws: technique and early results

PURPOSE

To present the technique and early results of percutaneous stabilization of U-shaped sacral fractures with attention to neurologic recovery and maintenance of fracture reduction of the sacrum.

DESIGN

Retrospective clinical study.

SETTING

Level I trauma center.

PATIENTS

During a thirty-eight-month period, 442 patients with pelvic ring disruptions were treated at a Level I trauma center. Thirteen (2.9 percent) of these patients had displaced U-shaped sacral fractures treated with percutaneous stabilization.

INTERVENTION

Fracture stabilization was accomplished using fluoroscopically guided iliosacral screws inserted percutaneously with the patient positioned supine. Neurodiagnostic monitoring was not used during screw insertions. This technique was limited to patients with sacral kyphotic deformities, which allowed in situ fixation. Sacral neurologic decompression was not performed.

MAIN OUTCOME MEASUREMENTS

Fracture healing and the stability of fixation were assessed on inlet and outlet radiographs and a lateral sacral view. Detailed neurologic examinations were performed at injury and at follow-up.

RESULTS

The sacral fractures were classified based on plain pelvic radiographs and computed tomography scans and included one Type 1, eight Type 2, and four Type 3 fracture patterns. Twenty-five fully threaded cancellous 7.0-millimeter cannulated screws were used. Eleven patients had bilateral screw fixations; one patient had unilateral double screw fixation; and one patient had unilateral single screw fixation. Operative time for screw insertion averaged forty-eight minutes, with 2.1 minutes of fluoroscopy per screw. Accurate screw insertions without neuroforaminal or sacral spinal canal violations were confirmed in all patients with postoperative pelvic plain radiographs and computed tomography scans. A paradoxical inlet view of the upper sacral segments on the injury anteroposterior pelvis was seen in twelve of thirteen patients (92.3 percent), and the diagnosis was confirmed with the lateral sacral view in all thirteen (100 percent) patients. Preoperatively, sacral kyphosis averaged 29 degrees, whereas postoperative sacral kyphosis averaged 28 degrees. Screw disengagement occurred without a change in position of the sacral fracture in the only patient treated with a single unilateral screw. All fractures healed clinically and radiographically. Of the nine patients with preoperative neurologic abnormalities, two (22 percent) patients had residual neurologic deficits. Both patients had associated multiple level lumbar burst fractures, which required decompression and instrumented stabilization.

CONCLUSIONS

These sacral fractures are rare and occur after significant spinal axial loading. A paradoxic inlet view of the upper sacrum on the anteroposterior plain pelvic radiograph heralds the diagnosis. Delayed diagnosis is avoided by a high clinical suspicion, early lateral sacral radiographs, and pelvic computed tomography scans. Surgical stabilization may assist in early mobilization of the patient from recumbency and prevents progressive deformity with associated nerve root injury. Percutaneous fixation diminishes potential blood loss and operative times, yet still allows subsequent sacral decompression of the local neural elements using open techniques when necessary. Early percutaneous iliosacral screw fixation is effective treatment for these injuries.

Regulation of bleomycin-induced DNA breakage and chromatin structure in lung endothelial cells by integrins and poly(ADP-ribose) polymerase

Activation of endothelial cell integrins inhibits DNA breakage by diverse agents, including the DNA-damaging agent bleomycin. DNA breaks activate nuclear poly(ADP-ribose) polymerase (PARP), which regulates chromatin structure and DNA repair. We determined the role of PARP in suppression of bleomycin genotoxicity by integrins using wild-type and PARP knockout mouse lung endothelial cells (MLEC), and the PARP inhibitor, 3-aminobenzamide (3AB). Activation of beta1 integrins by antibody clustering enhanced the sensitivity of wild-type nuclei to digestion with micrococcal nuclease and deoxyribonuclease I, indicating that chromatin structure was altered. 3AB blocked this effect. Knockout and 3AB-treated wild-type MLEC were hypersensitive to deoxyribonuclease I compared with wild-type cells, demonstrating that PARP regulates chromatin structure. Integrin clustering reduced the hypersensitivity of knockout cells, suggesting additional, PARP-independent mechanisms that inhibit nuclease interaction with chromatin. Bleomycin caused DNA breakage in wild-type and knockout MLEC. Breaks were eliminated after 60 min incubation of wild-type cells in drug-free medium, whereas 3AB or PARP knockout inhibited DNA repair. Integrin clustering protected wild-type cells from DNA breakage, and 3AB and PARP knockout inhibited this protection. Bleomycin caused large increases in PARP activity in wild-type but not knockout MLEC, and integrin clustering inhibited the activation of PARP. The results indicate that the antigenotoxic effects of integrin activation require PARP and that integrins alter chromatin structure by PARP-dependent and -independent mechanisms.

UCN-01 and camptothecin induce DNA double-strand breaks in p53 mutant tumor cells, but not in normal or p53 negative epithelial cells

Previous research has shown synergistic growth inhibition between UCN-01 and camptothecin (CPT) in tumor cells with mutant p53 versus tumor cells with wild-type p53. To determine the possible role of p53 in this drug combination, we tested the hypothesis that the synergistic growth inhibition is due to the absence of p53, and can result from the induction of DNA double-strand breaks (DSBs). Experiments were performed with the use of normal human mammary epithelial cells (HMEC); HMEC transfected with HPV16 E6 protein which inactivates p53 (HE6), or p53-mutant MDA-MB-231 tumor cells. CPT, UCN-01, or a 1:1 combination of both, in either HMEC or HE6 cells did not induce DSBs. In contrast, simultaneous treatment of MDA-MB-231 cells with both UCN-01 and CPT induced significant levels of DSBs while treatment with either drug alone did not. While UCN-01 was surprisingly potent against HMEC, the growth inhibition was only additive between UCN-01 and CPT against these cells. HE6 cells were much less sensitive than HMEC to UCN-01 and slightly less sensitive to the combined treatment with UCN-01 and CPT. The drug combination was synergistic against HE6 cells, due to their lower sensitivity to UCN-01. Unlike what was observed previously in MDA-MB-231 cells, UCN-01 did not abrogate CPT-induced inhibition of DNA synthesis in either HMEC or HE6 cells. These data indicate that synergistic growth inhibition by UCN-01 and CPT against p53 mutant MDA-MB-231 tumor cells may be due to induction of DSBs however the loss of p53 function alone does not sensitize normal cells to the combination of both drugs.

Enhancement of camptothecin-induced cytotoxicity with UCN-01 in breast cancer cells: abrogation of S/G(2) arrest

PURPOSE

To determine the ability of UCN-01 to abrogate the cell cycle arrest induced by camptothecin (CPT) in tumor cells that lack p53 function, and therefore enhance the cytotoxicity of CPT in these cells in relation to normal cells with wild-type p53.

METHODS

The responses of MDA-MB-231 and GI 101A breast cancer cells were compared to those of normal bovine endothelial cells. Cytotoxicity was assessed by the MTT assay, and the resulting data were modeled using median-effect analysis. Inhibition of DNA synthesis was determined by loss of [(3)H]thymidine incorporation, and cell cycle status was determined by flow cytometric analysis of propidium-iodide-stained nuclei.

RESULTS

UCN-01, a specific inhibitor of protein kinase C (PKC) presently in clinical trials, abrogated CPT-induced activation of S and G(2) checkpoints in human MDA-MB-231 and GI 101A breast carcinoma cells, both of which are mutants for the p53 gene. This abrogation occurred with the use of sublethal doses (100 nM) of UCN-01 and correlated with the enhancement of CPT-induced cytotoxicity. Median-effect analysis showed that synergistic cytotoxic interactions existed between CPT and UCN-01 against these tumor cells. In normal cells, however, abrogation of the S phase arrest caused accumulation in G(0)/G(1) phase, perhaps by the presence of wild-type p53 activity, with no change in CPT-induced cytotoxicity.

CONCLUSION

We have shown previously that the cytotoxicity of CPT is correlated with cell cycle response in normal and tumor cells. Low doses of CPT arrest cells in the G(2)/M phase and inhibit DNA synthesis, but higher doses cause arrest of cells in S phase. Thus modulation of events at the S and G(2) checkpoints may provide an opportunity to enhance CPT-induced cytotoxicity in tumor cells. The results of this study indicate that UCN-01 enhances the progression of tumor cells through S phase thus greatly increasing CPT-induced cytotoxicity. Normal cells, however, are able to arrest in G(0)/G(1) and thus avoid the increased toxicity induced by CPT. Our findings suggest potential usefulness of combining UCN-01 in topoisomerase I inhibitor-based drug therapy for the treatment of breast cancer with a dysfunctional p53 gene.

Antiangiogenic potential of camptothecin and topotecan

PURPOSE

To determine the inhibitory nature of sublethal doses of camptothecin (CPT) and topotecan (TPT) treatments on normal human endothelial cells in vitro, as well as the in vivo antiangiogenic activity as compared to another antiangiogenic compound, TNP-470 and to a nonspecific cytotoxic agent, cisplatin.

METHODS

Growth inhibition was determined by the crystal violet assay to measure relative cell numbers. (3)H-thymidine uptake was used to determine the inhibitory effect of CPT and TPT on DNA synthesis in vitro. Cell viability was determined using trypan blue exclusion assays. Cell cycle response to CPT was determined by flow cytometric analysis of propidium iodide-stained nuclei. In vivo inhibition of angiogenesis was determined by the disc angiogenesis system (DAS), where surgical sponge discs were placed subcutaneously in the rat dorsum and the ability of systemic treatment with liposomal CPT (LCPT), TPT, TNP-470 or cisplatin to inhibit vascular growth into the discs was evaluated. Quantitation of vascular growth was determined using toluidine blue staining of sectioned discs followed by digital image analysis.

RESULTS

Treatment with 50 nM CPT or TPT inhibited human umbilical venular endothelial cell (HUVEC) growth as shown by crystal violet staining, but was not cytotoxic to the cells. This was evidenced by the fact that cell numbers did not increase or decrease with treatment, but remained static while cells were viable for over 96 h posttreatment. (3)H-thymidine uptake in HUVEC was inhibited as early as 5 min, reached a maximum inhibition at 24 h and lasted over 96 h posttreatment. Cell cycle analysis of CPT-treated HUVEC showed arrest in S-phase at 12 h with a concurrent decrease in population of cells in G(1). Accumulation of cells at the G(2)/M-phase was discernible at 24 h along with the S-phase inhibition. Treatment of rats with 1 mg/kg LCPT or TPT every other day for 14 days resulted in approximately 30% inhibition of vascular growth into the discs. This inhibition was similar to the inhibition seen with TNP-470, an established and potent angiogenic inhibitor. In contrast, cisplatin was not as effective in inhibiting vascular growth into the discs.

CONCLUSIONS

In this work we showed that CPT and TPT inhibit human endothelial cell growth in vitro in a non-cytotoxic manner and that this inhibition lasts more than 96 h after drug removal. We also showed that LCPT and TPT, unlike a nonspecific cytotoxic agent, cisplatin, are as effective as TNP-470 in inhibiting angiogenic growth in the in vivo disc angiogenesis model. From this observation we propose that in addition to their proven tumoricidal activities, camptothecins may have an indirect in vivo antitumor effect mediated through the inhibition of angiogenesis.

Superior gluteal artery injury during iliosacral screw placement

Percutaneous fixation of an unstable pelvic ring injury is becoming a popular method of pelvic stabilization. As posterior pelvic percutaneous techniques become more common, the possibility of iatrogenic complications increases. This case report describes an injury to the superior gluteal artery during percutaneous iliosacral screw insertion and the treatment of this potentially devastating injury.

Displaced avulsion of the ischial apophysis: a hamstring injury requiring internal fixation

A case is reported of an adolescent sprinter who was chronically disabled by pain after non-operative management for an acute hamstring injury. He had sustained an avulsion fracture of the ischial apophysis with displacement of 2.5 cm. Avulsion fractures of the ischial apophysis with displacement of 2 cm or more are unusual, but they frequently result in a symptomatic non-union, and early diagnosis, open reduction, and internal fixation is to be encouraged.

Sensitivity to camptothecin of human breast carcinoma and normal endothelial cells

PURPOSE

To assess parameters that might determine resistance to the topoisomerase I inhibitor, camptothecin (CPT), the sensitivities of three established human breast cancer cell lines (ER-) and of normal bovine endothelial cells to CPT in the free form and incorporated into liposomes (LCPT), were contrasted with topoisomerase I (topo I) content and activity, and with cell cycle response to CPT treatment.

METHODS

Drug sensitivities were determined using the tetrazolium dye assay and by 3H-thymidine incorporation. Topo I levels were determined by Western blot analysis, and catalytic activity was determined with a plasmid relaxation assay, using nuclear protein from each cell line. CPT stabilization of cleavable complexes in nuclear extracts was determined using a labeled oligonucleotide with a specific topo I cleavage site. Cell cycle response to CPT was determined by flow cytometric analysis of propidium iodide-stained nuclei.

RESULTS

CPT was extremely potent against MDA-MB-157 cells with an IC50 value of 7 nM compared with IC50 values of 150 nM for GI 101A and 250 nM for MDA-MB-231 cells. In contrast, CPT inhibited the incorporation of 3H-thymidine at very low doses in GI 101A and MDA-MB-231 cells with IC50 values of 9 nM and 5 nM, respectively; while MDA-MB-157 cells did not stop incorporating 3H-thymidine until very high doses (500 nM) of CPT were used. When incorporated into multilamellar liposomes (LCPT), CPT retained its potency, with IC50 values similar to that of the free drug. No correlation was found between CPT-induced cytotoxicity and any of the topo I parameters determined. Cell cycle analysis, however, showed an accumulation of cells in G2/M phase after 24 h treatment with low doses (5 nM) of CPT in only GI 101A and MDA-MB-231 cells with no arrest in normal endothelial or MDA-MB-157 cells. At higher doses (50 nM), however, a dramatic accumulation of cells in the S phase was observed in MDA-MB-157, MDA-MB-231 and GI 101A cells. In contrast, a G2/M phase block was seen with the normal bovine endothelial cells using the higher doses of CPT.

CONCLUSIONS

The results suggest that cell cycle regulation plays an important role in determining the effect of CPT on malignant and normal cells. The possible mechanisms explaining the sensitivities of the two cellular compartments to the action of CPT are discussed.

An audit of hospital mortality after urgent and emergency surgery in the elderly

An audit was carried out of 102 patients aged over 75 years undergoing urgent or emergency surgery in a district general hospital. The risk of death in hospital after general surgery (13 deaths in 49 patients) was greater than after orthopaedic surgery (two deaths in 53 patients) (P < 0.05). In particular, laparotomy carried a high in-hospital mortality: 12 of 25 patients undergoing laparotomy died. Risk of death after general surgery increased with increasing preoperative ASA class, increasing medical risk factors and duration of operation. Orthopaedic cases were fitter than the general surgical cases as determined by ASA class and the number of medical risk factors. NCEPOD has recommended increased involvement of senior medical staff in operations, reduced night-time operating and avoidance of futile surgery. A high proportion of cases were operated on and anaesthetised by higher specialist trainees and consultants. Death rate was not affected by the seniority of doctors involved, nor by the time of day the operation took place. General surgical deaths were predictable postoperatively in most cases, but preoperative prediction of outcome was not specific enough to alter management.

Synthesis, structure-activity relationships, and pharmacokinetic properties of dihydroorotate dehydrogenase inhibitors: 2-cyano-3-cyclopropyl-3-hydroxy-N-[3'-methyl-4'-(trifluoromethyl)phenyl ] propenamide and related compounds

The active metabolite (2) of the novel immunosuppressive agent leflunomide (1) has been shown to inhibit the enzyme dihydroorotate dehydrogenase (DHODH). This enzyme catalyzes the fourth step in de novo pyrimidine biosynthesis. A series of analogues of the active metabolite 2 have been synthesized. Their in vivo biological activity determined in rat and mouse delayed type hypersensitivity has been found to correlate well with their in vitro DHODH potency. The most promising compound (3) has shown activity in rat and mouse collagen (II)-induced arthritis models (ED50 = 2 and 31 mg/kg, respectively) and has shown a shorter half-life in man when compared with leflunomide. Clinical studies in rheumatoid arthritis are in progress.

The nursing practice environment, staff retention, and quality of care

The effects of key factors in the nursing practice environment--management style, group cohesion, job stress, organizational job satisfaction, and professional job satisfaction--on staff nurse retention and process aspects of quality of care were examined. Hinshaw and Atwood's (1985) anticipated turnover model was modified and expanded to include relevant antecedent and outcome variables. The four-stage theoretical model was tested using data from 50 nursing units at four acute care hospitals in the southeast. The model explained 49% of the variance in staff nurse retention and 39% of the variance in process aspects of quality of nursing care. Study findings warrant careful consideration in light of recent practice environment changes: experience on the unit and professional job satisfaction were predictors of staff nurse retention; job stress and clinical service were predictors of quality of care. The variable contributing the most to indirect, and in turn, total model effects, was that of management style. These results substantiate the belief that aspects of the practice environment affect staff nurse retention, and most importantly, the quality of care delivered on hospital nursing units.

Ventilator-associated pneumonia due to Pseudomonas aeruginosa

OBJECTIVE

Ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa has been associated with higher case fatality rates than VAP caused by other bacterial etiologies. The causes of this excess mortality are unclear.

DESIGN

Retrospective review of 38 consecutive ventilated patients with Pseudomonas pneumonia, documented by highly reliable methods. Charts of five additional patients were unavailable for review.

SETTING

Medical ICUs of a university-affiliated Veterans Affairs Medical Center and a university-affiliated municipal hospital.

MEASUREMENTS

Prospectively collected hospital admission acute physiologic and chronic health examination (APACHE) II scores and cause of ICU admission. Retrospectively calculated organ failure and APACHE scores, VAP score. Clinical and microbiologic variables. Antibiotic treatment and outcome. Direct cause of death by standard definitions.

RESULTS

Overall mortality was 69% (26/38), significantly higher than the APACHE II predicted mortality of 42.6% (p=0.037). At least 38% (10/26) of deaths were directly attributable to Pseudomonas VAP. Multivariate analysis of factors associated with death found infectious cause for ICU admission (odds ratio [OR]=8.67; 95% confidence interval [CI], 0.86 to 85.94) and number of organ dysfunctions on the day of diagnosis (OR=1.73, 95% CI, 1.02 to 2.92) were significant. Septic shock from Pseudomonas VAP, septic shock from subsequent infection, and multiple organ dysfunction syndrome were the most common immediate causes of death. Mortality increased linearly with increasing APACHE III score on the day of diagnosis. Of initial antibiotic regimens, 67% (26/36) were considered failures. Persistent pneumonia occurred in 35% of patients while recurrent pneumonia was unusual (1/38).

CONCLUSIONS

Development of Pseudomonas pneumonia results in a mortality rate in excess of that due to the presenting illness. The attributable mortality determined by several means appears to approach 40%. The excess mortality appears to be related to the host defense response to the pneumonia rather than any characteristic of the pneumonia. Even standard antibiotic regimens fail frequently and do not prevent the excess mortality. Since at least 38% of deaths can be directly attributable to the Pseudomonas pneumonia, improvement in therapy is needed.

Hydroxylation of lauramide diethanolamine by liver microsomes

Lauramide diethanolamine (LDEA)--a compound used in cosmetics and soap products as an emollient, thickener, and foam stabilizer--was observed to be metabolized by rat liver microsomes to two major products that were identified by GC/MS to be the 11-hydroxy and 12-hydroxy derivatives of LDEA. The specific activities for LDEA 11- and 12-hydroxylation in microsomes prepared from control rats were 2.23 +/- 0.40 and 0.71 +/- 0.17 nmol/min/mg protein, respectively. Treatment of rats with the cytochrome P4504A inducer and peroxisome proliferator, diethylhexyl phthalate, increased the LDEA 12-hydroxylation rate to 3.50 +/- 0.48 nmol/min/mg protein, a 5-fold increase in specific activity, whereas the LDEA 11-hydroxylase activity remained unchanged. Because LDEA contains a 12-carbon side chain, LDEA hydroxylation rates were compared with the hydroxylation rates for lauric acid. The specific activities of lauric acid 11- and 12-hydroxylation reactions in diethylhexyl phthalate-treated rats were 1.7-fold and 3.2-fold greater than the LDEA 11- and 12-hydroxylation rates, respectively. When LDEA hydroxylation reactions were performed in the presence of a polyclonal antibody to the rat P4504A forms, formation of 12-hydroxy-LDEA was inhibited by 80%. Rat kidney microsomes also supported the hydroxylation of LDEA at its 11- and 12-carbon atoms, with specific activities of 0.05 +/- 0.01 and 0.28 +/- 0.02 nmol/min/mg protein, respectively. LDEA was also metabolized to 11- and 12-hydroxy derivatives by human liver microsomes at specific activities of 0.22 +/- 0.06 and 0.84 +/- 0.26 nmol/min/mg protein, respectively.

Ventilator-associated Pseudomonas aeruginosa pneumonia: radiographic findings

PURPOSE

To characterize the radiographic features of ventilator-associated Pseudomonas aeruginosa pneumonia (PAP).

MATERIALS AND METHODS

In 56 patients (40 men and 16 women), PAP was documented with fiberoptic bronchoscopy. All patients underwent mechanical ventilation for at least 48 hours before diagnosis. The findings on chest radiographs were recorded. In eight patients in whom computed tomography (CT) was performed, results were compared with radiographic findings.

RESULTS

Twenty-six patients with adult respiratory distress syndrome (ARDS) had diffuse bilateral confluent opacities; 30 patients without ARDS had multifocal opacities. In 13 patients, cavities were detected at chest radiography, CT, or both. Seven of 29 patients with pleural abnormalities had empyema. CT provided important additional information (presence of cavities or effusions) in four cases.

CONCLUSION

Findings on chest radiographs are nonspecific for PAP. The frequencies of cavities and empyema are surprisingly low, perhaps owing to prompt diagnosis and therapy.

Causes of fever and pulmonary densities in patients with clinical manifestations of ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia, a leading cause of sepsis in patients with acute respiratory failure, is difficult to distinguish clinically from other processes affecting patients receiving mechanical ventilation. We conducted a prospective study of patients with suspected ventilator-associated pneumonia to identify the causes of fever and densities on chest radiographs and to evaluate the diagnostic yield and efficiency of tests used alone and in combination.

METHODS

The 50 patients entered into the study underwent a systematic diagnostic protocol designed to identify all potential causes of fever and pulmonary densities. Diagnoses responsible for fever were established by strict diagnostic criteria for 45 of the 50 patients. The prevalence of specific conditions and diagnostic yield of individual tests were used to formulate a simplified diagnostic protocol.

RESULTS

The diagnostic protocol identified 78 causes of fever (median 2 per patient). Infections were the leading causes of fever and pulmonary densities. Of the 45 patients with fever, 37 had one or more infections identified (67 sources). Most infections (84 percent) were one of four types:pneumonia, sinusitis, catheter-related infection, or urinary tract infection. Ventilator-associated pneumonia occurred in only 42 percent. All but nine infections (87 percent) were directly or indirectly related to insertion of a catheter or a tube. Concomitant infections were frequent (62 percent), particularly in patients with sinusitis (100 percent), catheter-related infections (93 percent), and pneumonia (74 percent). Of concomitant infections, 60 percent were caused by a different pathogen. Noninfectious causes of fever were more common in the 22 patients with adult respiratory distress syndrome. Histologically proved pulmonary fibroproliferation was the only cause of fever in 25 percent of patients with adult respiratory distress syndrome. Radiographic densities were caused by an infection in only 20 patients (19 pneumonia, 1 empyema). In more than 50 percent of the 25 patients without adult respiratory distress syndrome, congestive heart failure, and atelectasis were the sole causes of pulmonary densities, and fever always originated from an extrapulmonary site of infection. Used in combination, bronchoscopy with protected sampling, computed tomographic scan of the sinuses, and cultures of maxillary sinus aspirate, central intravenous or arterial lines, urine, and blood identified 58 of the 78 sources of fever (74 percent).

CONCLUSIONS

The observations in this study document the complex nature of acute respiratory failure and fever and underscore the need for accuracy in diagnosis. The frequent occurrence of multiple infectious and noninfectious processes justifies a systematic search for source of fever, using a comprehensive diagnostic protocol. A simplified diagnostic protocol was devised based on the diagnostic value of individual tests.

What is a reasonable orthopaedic surgical workload? An analysis of elective and trauma workloads using two different complexity scoring systems

A 1-year prospective study of all surgical activity was undertaken by the Orthopaedic Unit using two weighting systems for operative complexity: the Intermediate Equivalent (IE) and the Operative Complexity Score (OCS). The objectives were to define the difference between caseload and workload, and to formulate a reasonable workload for an operating session and a reasonable annual workload for a consultant team. In both elective and trauma surgery the BUPA complex, major+ and major operations represented 50 per cent of the caseload but accounted for approximately 68 per cent of the workload. The BUPA minor and intermediate procedures representing the remaining 50 per cent of the caseload accounted for only 32 per cent of the workload. The number of hours required to undertake all the complex, major+ and major operations was approximately twice that required for the number of minor and intermediate procedures. Despite the marked variation in case mix, the workload achieved by the six teams in the same number of sessions was remarkably similar. On the basis of two consultant and one registrar elective lists per week, a total of 705 IEs (1795 OCS units) could be undertaken by each team in 1 year. An average of 458 IEs (1086 OCS units) of trauma surgery were undertaken by each team. Caseload is a poor performance indicator of surgical activity. This study supports the concept of 3.5-4.0 IEs as reasonable workload for an orthopaedic elective operating session, and 900 IEs (2200 OCS units) as a reasonable annual workload for an orthopaedic team.

Shared governance and the nursing practice environment

An evaluation of the impact of shared governance on staff nurse perceptions of management style, group cohesion, job stress, job satisfaction, and anticipated turnover provides support for claims that shared governance improves the nursing practice environment.

Heary metals and lipofuscinogenesis. A study on myocardial cells cultured under varying oxidative stress

The aim of this study was to examine the influence on lipofuscinogenesis of a number of transition and non-transition heavy metals in cultured post-mitotic cells (neonatal rat myocytes) at varying oxidative stress. The effects of Al, Cd, Cr, Cu, Hg, Pb and Zn, added to the medium as chlorides, were examined after 14 days in culture under 5, 20 and 40% ambient oxygen. Lipofuscin was quantified by microspectrofluorometry of individual cells. The addition of Al (40 microM), Cd (40 nM), Hg (30 microM) and Pb (40 microM) to the culture growth medium markedly increased the amount of intracellular lipofuscin, whereas Cr (40 microM), Cu (40 microM) and Zn (40 microM) had the opposite effect. Transmission electron microscopic examination of the myocytes showed greatly increased numbers of autophagic vacuoles in cells exposed to those heavy metals that increased lipofuscin formation. This effect was most pronounced when cells were grown at high (40%) oxygen tension. Possible explanations for the metal augmented pigment formation may be (i) inhibition of lysosomal enzymes, (ii) catalytic interference with peroxidative reactions, or (iii) general toxicity with unspecifically increased autophagocytosis. The decreased pigment accumulation after the addition of Zn, Cr and Cu may, at least partly, be related to the replacement of iron, which has catalytic activity in Fenton reactions.

A novel hypothesis of lipofuscinogenesis and cellular aging based on interactions between oxidative stress and autophagocytosis

Based on a series of experiments, using cultured postmitotic neonatal rat cardiac myocytes as a model system, we present a novel hypothesis of lipofuscin formation. This hypothesis proposes that lipofuscin is formed within secondary lysosomes due to an interplay of two processes, the production of partially reduced oxygen species by mitochondria and the autophagocytotic degradation within secondary lysosomes. Specifically, it is proposed that H2O2 generated by mitochondria and other organelles permeates into the lumen of secondary lysosomes, which contain iron derived from cellular structures undergoing intralysosomal degradation. The interaction between reactive ferrous iron and H2O2 results, via Fenton-type mechanisms, in the generation of hydroxyl free radicals (OH), inducing lipid peroxidation and eventually leading to intermolecular cross-linking and lipofuscin formation. Additionally, mitochondria undergoing intralysosomal decomposition might continue for a certain period to produce superoxide anion radicals (O2-) and thus also H2O2. This model of lipofuscinogenesis could satisfactorily explain the variations observed in the rates of lipofuscinogenesis among different postmitotic cell types in various species. Such variations might arise from a variety of factors including differences in the efficiency of the 'anti-oxidative shield', rate of H2O2 generation, amount of chain-breaking antioxidants, mode of intralysosomal iron chelation, rate of autophagocytosis as well as degree of efficiency of the intralysosomal hydrolytic enzymes.

Calculating and updating nursing turnover costs

A detailed study allowed FY 1988 nursing turnover costs to be calculated at four southeastern hospitals. These turnover costs were later updated using a procedure incorporating Consumer Price Index information. This procedure allows nurse administrators to determine and update turnover costs, to accurately evaluate the impact of nursing turnover, and to facilitate resource allocation.

A combined intra- and extra-articular reconstruction using a carbon-dacron composite prosthesis for chronic anterior cruciate instability. A two to six-year follow-up study

Fifty patients with chronic symptomatic anterior cruciate insufficiency underwent ligamentous reconstruction using the "Westminster Composite Prosthesis" which consists of a central core of carbon fibre with an external weave of polyester. In 42 patients, the prosthesis was used as an augmentation within a tube of ilio-tibial tract, combined with a MacIntosh's extraarticular reconstruction. The prosthetic replacement alone was used in eight patients where there had been a previous extraarticular reconstruction and was associated with only fair results. The average age of the patients at operation was 28.5 years (range 18 to 50 years); instability of the knee had been present for a mean of 5.3 years and the average follow-up was 3.8 years (range 2 to 6 years). Assessment included subjective functional rating (Lysholm knee score) and clinical examination for instability. Thirty-seven patients (74%) had a good or excellent result, 11 (22%) had a fair result and two (4%) had a poor result. The Lachman test was grade I or less in 35 patients and the pivot shift sign was eliminated in 37 patients. Clinical signs of instability correlated well with the Lysholm knee score (p less than 0.001). Twenty-two unselected patients (44%) underwent an arthroscopic assessment and biopsy of the "neoligament" at an average of 10.4 months post-operatively. The prosthesis was found to be stable and well covered by a thick fibrous sheath ("neoligament") in 19 patients. The prosthesis was partially ruptured in two patients and completely disrupted in one. Thirty-two patients (64%) returned to their previous sports and 13 of them (26%) achieved their pre-injury level of performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive face mask mechanical ventilation in patients with acute hypercapnic respiratory failure

Mechanically assisted intermittent positive-pressure ventilation effectively provides ventilatory support in patients with respiratory failure but it requires placing an artificial airway. We have previously reported our successful experience delivering mechanical ventilation via a face mask (FMMV) rather than with an endotracheal tube in a pilot study of patients with acute respiratory failure. The present investigation evaluated an additional 18 patients with hypercapnic respiratory failure to determine the efficacy of FMMV in a more homogeneous group and to determine factors predicting its success. FMMV was successful in avoiding intubation in 13 of the 18 patients. A significant initial improvement in PCO2 (greater than 16 percent decrease) and in pH (from less than 7.30 to greater than 7.30) predicted success. The five patients who failed on FMMV required endotracheal intubation because of inability to improve gas exchange (three patients), apnea due to sedatives (one patient), and management of secretions (one patient). FMMV was generally well accepted with only two patients withdrawn because of intolerance of the mask. The mean duration of FMMV was 25 h. Complications were seen in only two patients (11 percent): aspiration (one patient) and mild skin necrosis (one patient). Seven patients entered the study by meeting entrance criteria after an unsuccessful extubation attempt and therefore received both forms of mechanical ventilation. All but one patient avoided reintubation, and the face mask proved to be as effective as the endotracheal tube as a conduit for delivering the mechanical tidal volume and improving gas exchange. Our findings indicate that FMMV is a viable option for short-term (one to four days) ventilatory support of patients with hypercapnic respiratory failure and insufficiency.

Staff nurse turnover costs: Part II, Measurements and results

This study demonstrated that the costs of nursing turnover can be high (over +10,000 per RN turnover), and that the potential for adverse impact on the nursing department, the hospital environment, and the healthcare environment exists. The results of this study are important, particularly in the midst of a national nursing shortage, for several reasons. CNEs are responsible for obtaining, allocating, and managing nursing department resources; knowledge of nursing turnover costs will allow them to make more informed decisions about how best to allocate scarce resources. The findings of this study are also important to hospital administrators because they demonstrate the financial impact of high rates of nursing turnover on healthcare delivery. Finally, these findings provide nurse researchers direction for future research into the costs and benefits of nursing turnover and retention activities, so that cost-effective methods of minimizing organizational costs can be determined.

Staff nurse turnover costs: Part I, A conceptual model

The impact of turnover is a major concern for the chief nurse executive. This study provides nurse administrators with information necessary to more fully understand the impact of turnover and assists them in developing and defending retention strategies. Part 1 addresses the conceptual model used to guide the study; Part 2 (May 1990) will discuss the application of the methodology to measure nursing turnover costs and the study's findings.

Epiphyseal distraction monitored by strain gauges. Results in seven children

Ten epiphyses in seven children underwent fixed-rate distraction of 0.25 mm twice daily in an attempt to achieve percutaneous leg lengthening by chondrodiatasis. The forces generated across the growth plate were recorded by means of strain gauges incorporated into the distractors. All epiphyses fractured before 33 days of lengthening. An average gain of 6.75 cm was achieved. Epiphyseal distraction at the lower femur produced many complications, but at the upper tibial epiphysis planned lengthening was achieved, with excellent bone production and few complications.

Prosthetic anterior cruciate ligaments in the rabbit. A comparison of four types of replacement

Four types of prosthetic replacement for the anterior cruciate ligament (carbon fibre, carbon fibre and Dacron composite, Dacron alone and bovine xenograft) were assessed at three, six and 12 months after implantation in the knees of New Zealand white rabbits. The synovium and both intra-articular and intra-osseous portions of the ligaments were examined macroscopically, by light microscopy and by scanning electron microscopy. All the knees showed mild synovitis, and there was no significant growth into the intra-articular part of any ligament. Carbon fibre and xenograft did not appear to be suitable materials in this animal model. The composite ligament showed short-term ingrowth of fibrous tissue only into the periphery of the sheath in its intra-osseous portion, whereas the Dacron ligament showed progressive fibrous tissue ingrowth with some bony incorporation of its outer fibres.

Tumours of the cauda equina. The problem of differential diagnosis

A retrospective study of 32 patients with primary tumours of the cauda equina is presented. Most of the patients were initially diagnosed as having prolapsed intervertebral discs and treated accordingly. The correct diagnosis was eventually made, usually after a long delay, and confirmed by myelography. Treatment consisted of laminectomy and excision of the tumour. Only one tumour was frankly malignant; all the remaining patients were relieved of their pain and the majority recovered completely. The exceptions were those patients with long-standing neurological deficits; this highlights the importance of early diagnosis and correct treatment before irreparable damage occurs.