Patients with surgical wounds healing by secondary intention: A prospective, cohort study.

BACKGROUND: Surgical wounds healing by secondary intention can be difficult and costly to manage and are profoundly under researched. This prospective inception, cohort study aimed to derive a better understanding of surgical wounds healing by secondary intention and to facilitate the design of future research investigating effective treatments. OBJECTIVES: To investigate the clinical characteristics of patients with surgical wounds healing by secondary intention and the surgeries that preceded their wounds; to clearly delineate the clinical outcomes of these patients, specifically focusing on time to wound healing and its determinants; to explore the types of treatments for surgical wounds healing by secondary intention; and to assess the impact surgical wounds healing by secondary intention have on patients' quality of life. DESIGN: Prospective, inception cohort study. SETTING: Acute and community settings in eight sites across two large centres in the United Kingdom (Hull and Leeds, UK). METHODS: Patients with a surgical wounds healing by secondary intention (an open wound, <3 weeks' duration, resulting from surgery), were recruited and followed up for at least 12 months. Key outcome events included: time to healing; treatment type; infection; hospital re-admission and further procedures; health-related quality of life and pain. RESULTS: In total, 393 patients were recruited. Common co-morbidities were cardiovascular disease (38%), diabetes (26%) and peripheral vascular disease (14.5%). Baseline median SWHSI area was 6 cm2 (range 0.01-1200). Abdominal (n = 132), foot (n = 59), leg (n = 58) and peri-anal (n = 34) wounds were common. The majority of wounds (236, 60.1%) were intentionally left open following surgery; the remainder were mostly dehisced wounds. Healing was observed in 320 (81.4%) wounds with a median time to healing of 86 days (95% CI: 75-130). Factors associated with delayed healing included wound infection at any point and baseline wound area above the median. Health-related quality of life scores were low at baseline but improved with time and healing. CONCLUSIONS: This is the first inception cohort study in patients with surgical wounds healing by secondary intention. Patient characteristics have been clearly defined, with prolonged healing times and adverse events being common impacting on patient's health-related quality of life. Areas for, and factors crucial to the design of, future research have been identified.

Pilot feasibility randomized clinical trial of negative-pressure wound therapy versus usual care in patients with surgical wounds healing by secondary intention.

BACKGROUND: Surgical wounds healing by secondary intention (SWHSI) are increasingly being treated with negative-pressure wound therapy (NPWT) despite a lack of high-quality research evidence regarding its clinical and cost-effectiveness. This pilot feasibility RCT aimed to assess the methods for and feasibility of conducting a future definitive RCT of NPWT for the treatment of SWHSI. METHODS: Eligible consenting adult patients receiving care at the study sites (2 acute and 1 community) and with a SWHSI appropriate for NPWT or wound dressing treatment were randomized 1 : 1 centrally to receive NPWT or usual care (no NPWT). Participants were followed up every 1-2 weeks for 3 months. Feasibility (recruitment rate, time to intervention delivery) and clinical (time to wound healing) outcomes were assessed. RESULTS: A total of 248 participants were screened for eligibility; 40 (16·1 per cent) were randomized, 19 to NPWT and 21 to usual care. Twenty-four of the 40 wounds were located on the foot. Participants received NPWT for a median of 18 (range 0-72) days. Two participants in the NPWT group never received the intervention and 14 received NPWT within 48 h of randomization. Five participants in the usual care group received NPWT during the study. Ten of the 40 wounds were deemed to have healed during the study. CONCLUSION: A full-scale RCT to investigate the clinical and cost-effectiveness of NPWT for SWHSI is feasible. This study identified crucial information on recruitment rates and data collection methods to consider during the design of a definitive RCT. Registration number: ISRCTN12761776 (http://www.iscrtn.com).

A survey of patients with surgical wounds healing by secondary intention; an assessment of prevalence, aetiology, duration and management.

BACKGROUND: Surgical wounds healing by secondary intention (SWHSI) are often difficult and costly to treat. There is a dearth of clinical and research information regarding SWHSI. The aim of this survey was to estimate the prevalence of SWHSI and to characterise the aetiology, duration and management of these wounds. METHODS: Anonymised data were collected from patients with SWHSI receiving treatment in primary, secondary and community settings. Over a two weeks period, data were collected on the patients, their SWHSI, clinical and treatment details. RESULTS: Data were collected from 187 patients with a median age of 58.0 (95% CI = 55 to 61) years. The prevalence of SWHSI was 0.41 (95% CI = 0.35 to 0.47) per 1000 population. More patients with SWHSI were being treated in community (109/187, 58.3%) than in secondary (56/187, 29.9%) care settings. Most patients (164/187, 87.7%) had one SWHSI and the median duration of wounds was 28.0 (95% CI = 21 to 35) days. The most common surgical specialities associated with SWHSI were colorectal (80/187, 42.8%), plastics (24/187, 12.8%) and vascular (22/187, 11.8%) surgery. Nearly half of SWHSI were planned to heal by secondary intention (90/187, 48.1%) and 77/187 (41.2%) were wounds that had dehisced. Dressings were the most common single treatment for SWHSI, received by 169/181 (93.4%) patients. Eleven (6.1%) patients were receiving negative pressure wound therapy. CONCLUSIONS: This survey provides a previously unknown insight into the occurrence, duration, treatment and types of surgery that lead to SWHSI. This information will be of value to patients, health care providers and researchers.

HUS1 regulates in vivo responses to genotoxic chemotherapies.

Cells are under constant attack from genotoxins and rely on a multifaceted DNA damage response (DDR) network to maintain genomic integrity. Central to the DDR are the ATM and ATR kinases, which respond primarily to double-strand DNA breaks (DSBs) and replication stress, respectively. Optimal ATR signaling requires the RAD9A-RAD1-HUS1 (9-1-1) complex, a toroidal clamp that is loaded at damage sites and scaffolds signaling and repair factors. Whereas complete ATR pathway inactivation causes embryonic lethality, partial Hus1 impairment has been accomplished in adult mice using hypomorphic (Hus1(neo)) and null (Hus1(Δ1)) Hus1 alleles, and here we use this system to define the tissue- and cell type-specific actions of the HUS1-mediated DDR in vivo. Hus1(neo/Δ1) mice showed hypersensitivity to agents that cause replication stress, including the crosslinking agent mitomycin C (MMC) and the replication inhibitor hydroxyurea, but not the DSB inducer ionizing radiation. Analysis of tissue morphology, genomic instability, cell proliferation and apoptosis revealed that MMC treatment caused severe damage in highly replicating tissues of mice with partial Hus1 inactivation. The role of the 9-1-1 complex in responding to MMC was partially ATR-independent, as a HUS1 mutant that was proficient for ATR-induced checkpoint kinase 1 phosphorylation nevertheless conferred MMC hypersensitivity. To assess the interplay between the ATM and ATR pathways in responding to replication stress in vivo, we used Hus1/Atm double mutant mice. Whereas Hus1(neo/neo) and Atm(-/-) single mutant mice survived low-dose MMC similar to wild-type controls, Hus1(neo/neo)Atm(-/-) double mutants showed striking MMC hypersensitivity, consistent with a model in which MMC exposure in the context of Hus1 dysfunction results in DSBs to which the ATM pathway normally responds. This improved understanding of the inter-dependency between two major DDR mechanisms during the response to a conventional chemotherapeutic illustrates how inhibition of checkpoint factors such as HUS1 may be effective for the treatment of ATM-deficient and other cancers.

Longitudinal assessment of occupational exposures to the organophosphorous insecticides chlorpyrifos and profenofos in Egyptian cotton field workers.

Chlorpyrifos (CPF) and profenofos (PFF) are organophosphorus (OP) insecticides that are applied seasonally in Egypt to cotton fields. Urinary trichloro-2-pyridinol (TCPy), a specific CPF metabolite, and 4-bromo-2-chlorophenol (BCP), a specific PFF metabolite, are biomarkers of exposure, while inhibition of blood butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities are effect biomarkers that may be associated with neurotoxicity. Urinary TCPy and BCP and blood BChE and AChE activities were measured in 37 adult Egyptian Ministry of Agriculture workers during and after 9-17 consecutive days of CPF application followed by an application of PFF (9-11 days), and a second CPF application (5 days) in 2008. During the OP applications, urinary TCPy and BCP levels were significantly higher than baseline levels, remained elevated following the application periods, and were associated with an exposure related inhibition of blood BChE and AChE. Analysis of blood AChE levels before and after the PFF application period suggests that individual workers with peak BCP levels greater than 1000 µg/g creatinine exhibited further inhibition of blood AChE with PFF application, demonstrating that PFF exposure had a negative impact on AChE activity in this highly exposed worker population. While large interindividual differences in exposure were observed throughout this longitudinal study (peak urinary BCP and peak TCPy levels for individuals ranging from 13.4 to 8052 and 16.4 to 30,107 µg/g creatinine, respectively), these urinary biomarkers were highly correlated within workers (r=0.75, p<0.001). This suggests that the relative exposures to CPF and PFF were highly correlated for a given worker. The variable exposures between job classification and work site suggest that job title and work location should not be used as the sole basis for categorizing OP exposures when assessing neurobehavioral and other health outcomes in Egyptian cotton field workers. Together, these findings will be important in educating the Egyptian insecticide application workers in order to encourage the development and implementation of work practices and personal protective equipment to reduce their exposure to CPF and PFF.

On reducing information asymmetry in U.S. health care.

Information asymmetry is a significant issue facing the U.S. health care system. In this article, we investigate some methods of reducing this asymmetry. We trace the information asymmetry using the "wicked problem" of the health care distribution system. An information asymmetry reduction method requiring joint responsibilities among health care stakeholders is developed. It is argued that information asymmetry is a contributor to enormous health care inflation. Hence, any reduction in such asymmetry will reduce health care costs. Concepts from both signaling and corrective justice theories are integrated in this article to help reduce the information asymmetry that exists in the U.S. health care system. Getting health care costs in line with other "advanced" nations, is the long-term solution to the wicked problem that currently exists in the U.S. health care system. There is an immediate need for a centralized health care database with adequate provisions for individual privacy. Both processes as well as an outcome-based control system are essential for reducing information asymmetries in the U.S. health care system.

[A man with spontaneous pain in shoulders and hips]. / Een man met spontane pijnklachten van heupen en schouders.

A 19-year-old man presented with spontaneous pain in both hips and shoulders. X-ray of the pelvis showed osteopenia throughout the pelvis and a late stadium of coxarthrosis. MRI showed osteonecrosis on both sides in the femur head and acetabulum as well as both humerus heads. Glucocorticoids may induce osteonecrosis.

Metabolism of profenofos to 4-bromo-2-chlorophenol, a specific and sensitive exposure biomarker.

Profenofos is a direct acting phosphorothioate organophosphorus (OP) pesticide capable of inhibiting ß-esterases such as acetylcholinesterase, butyrylcholinesterase, and carboxylesterase. Profenofos is known to be detoxified to the biologically inactive metabolite, 4-bromo-2-chlorophenol (BCP); however, limited data are available regarding the use of urinary BCP as an exposure biomarker in humans. A pilot study conducted in Egyptian agriculture workers, demonstrated that urinary BCP levels prior to application (3.3-30.0 µg/g creatinine) were elevated to 34.5-3,566 µg/g creatinine during the time workers were applying profenofos to cotton fields. Subsequently, the in vitro enzymatic formation of BCP was examined using pooled human liver microsomes and recombinant human cytochrome P-450s (CYPs) incubated with profenofos. Of the nine human CYPs studied, only CYPs 3A4, 2B6, and 2C19 were able to metabolize profenofos to BCP. Kinetic studies indicated that CYP 2C19 has the lowest Km, 0.516 µM followed by 2B6 (Km=1.02 µM) and 3A4 (Km=18.9µM). The Vmax for BCP formation was 47.9, 25.1, and 19.2 nmol/min/nmol CYP for CYP2B6, 2C19, and 3A4, respectively. Intrinsic clearance (Vmax/Km) values of 48.8, 46.9, and 1.02 ml/min/nmol CYP 2C19, 2B6, and 3A4, respectively, indicate that CYP2C19 and CYP2B6 are primarily responsible for the detoxification of profenofos. These findings support the use of urinary BCP as a biomarker of exposure to profenofos in humans and suggest polymorphisms in CYP 2C19 and CYP 2B6 as potential biomarkers of susceptibility.

5% dimethyl sulfoxide (DMSO) and pentastarch improves cryopreservation of cord blood cells over 10% DMSO.

BACKGROUND: Cell number and viability are important in cord blood (CB) transplantation. While 10% dimethyl sulfoxide (DMSO) is the standard medium, adding a starch to freezing medium is increasingly utilized as a cytoprotectant for the thawing process. Similar to hetastarch, pentastarch has the advantages of faster renal clearance and less effect on the coagulation system. STUDY DESIGN AND METHODS: We compared a lower DMSO concentration (5%) containing pentastarch with 10% DMSO and performed cell viability assay, colony-forming units (CFUs), and transplantation of CB cells in NOD/SCID IL2Rγ(null) mice. RESULTS: CB cells in 5% DMSO/pentastarch had similar CD34+, CD3+, and CD19+ cell percentages after thawing as fresh CB cells. CB cells in 5% DMSO/pentastarch had higher viability (83.3±9.23%) than those frozen in 10% DMSO (75.3±11.0%, p<0.05). We monitored cell viability postthaw every 30 minutes. The mean loss in the first 30 minutes was less in the 5% DMSO/pentastarch group. At the end of 3 hours, the viability decreased by a mean of 7.75% for the 5% DMSO/pentastarch and 17.5% for the 10% DMSO groups. CFUs were similar between the two cryopreserved groups. Frozen CB cells engrafted equally well in IL2Rγ(null) mice compared to fresh CB cells up to 24 weeks, and CB cells frozen in 5% DMSO/pentastarch engrafted better than those in 10% DMSO. CONCLUSION: Our data indicate that the lower DMSO concentration with pentastarch represents an improvement in the CB cryopreservation process and could have wider clinical application as an alternate freezing medium over 10% DMSO.

A CT scan score for the assessment of lung disease in children with common variable immunodeficiency disorders.

BACKGROUND: The prevalence and severity of structural lung disease in children with common variable immunodeficiency (CVID) disorders is not well known, and a dedicated CT scanning protocol and CT scan scoring system have not been described in this category. METHODS: This was a cohort study of 54 children (34 CVID, 20 CVID-like disorder) in a stable condition who underwent volumetric inspiratory and end-expiratory CT scans. Scans were scored for airway abnormalities, interstitial and parenchymal lung disease, and lymphadenopathy using a newly developed CT scan scoring system. Scores were normalized to a 0% to 100% scale. Observer agreement was assessed using an intraclass correlation coefficient (Ri). Prevalence and severity of CT scan abnormalities were calculated. RESULTS: Structural lung disease was common (85%-93%), but usually mild as reflected in the relatively low scores (bronchiectasis score 2.8% +/- 6.4%). Moderate-to-severe bronchiectasis was found in three (5%) patients. Expiratory air trapping was the most common finding, found in 71% to 80%, but often in a mild form; application of a cut off level of > 10% reduced its prevalence to 33% to 38%. In 9% to 15% of all patients, air trapping was the only abnormality. Multiple lung nodules were seen in 24% to 25% and could disappear after corticosteroid treatment. Observer agreement was moderate (Ri 0.6-0.79) to good (Ri > 0.8) for all items and the composite scores, except airway wall thickening. CONCLUSION: In children with CVID disorders, mild structural lung disease is common. Expiratory CT scans show the most frequent abnormality, air trapping. The occurrence of (silent) lung disease progression and the clinical impact of CT scans require further investigations.

Rationale for an intraperitoneal gemcitabine chemotherapy treatment for patients with resected pancreatic cancer.

Currently, the surgical management of pancreas cancer is recognized around the world as inadequate. Long-term survival is rare even though there is a potentially curative R0 resection. There is a strong rationale for the use of chemotherapy in the operating room to reduce local-regional and hepatic sites of recurrent/progressive disease. Gemcitabine monotherapy administered by an intraperitoneal route in the operating room with hyperthermia and then for long-term treatment postoperatively has a strong pharmacologic basis. The exposure of peritoneal surfaces to intraperitoneal gemcitabine is approximately 500 times the exposure that occurs within the plasma. By analogy to another lethal disease, ovarian cancer, intraperitoneal gemcitabine chemotherapy used following potentially curative resection is supported. Data that shows a superiority of multiagent chemotherapy to gemcitabine monotherapy has not been reported. A standardized treatment with intraoperative chemotherapy monitoring of gemcitabine would greatly facilitate further improvements in pancreas cancer treatment and lead the way to an evolution of more successful treatment strategies of this dread disease. The aim of this review is to present the recent available medical information and patents applicable to patients with resected pancreatic cancer.

Pharmacokinetics and pharmacodynamics of perioperative cancer chemotherapy in peritoneal surface malignancy.

The peritoneal surface remains an important failure site for patients with gastrointestinal and gynecologic malignancies. During the last 2 decades, novel therapeutic approaches, combining cytoreductive surgery with intraoperative intracavitary and intravenous chemotherapy, have emerged for peritoneal carcinomatosis patients. This has resulted in remarkable clinical successes in contrast with prior failures. Although further clinical data from phase II and III trials supporting this combined treatment protocols are necessary, an optimalization of the wide variety of different perioperative cancer chemotherapy protocols used in these treatment regimens is equally important. To this date, a clear understanding of the pharmacology of perioperative chemotherapy is still lacking. The efficacy of intraperitoneal cancer chemotherapy protocols is governed as much by nonpharmacokinetic variables (tumor nodule size, density, vascularity, interstitial fluid pressure, and binding) as by the pharmacokinetic variables (dose, volume, duration, pressure, and carrier solution). Our recent data support the importance of the tumor nodule as the most meaningful pharmacologic end point. Timing of perioperative intravenous chemotherapy may substantially influence the pharmacokinetics. This review aims to clarify the pharmacokinetic and pharmacodynamic data currently available regarding the intraperitoneal delivery of cancer chemotherapy agents in patients with peritoneal carcinomatosis.

Low-dose parenteral busulfan provides an extended window for the infusion of hematopoietic stem cells in murine hosts.

OBJECTIVE: Myeloablative total body irradiation (TBI) in the setting of autologous transplantation of genetically modified hematopoietic stem cells (HSC) is associated with substantial toxicity. Nonmyeloablative doses of TBI are less toxic, but result in low-level engraftment of genetically modified HSCs. As an alternative to TBI, escalating doses of parenteral busulfan were tested for their hematologic toxicity, their ability to promote donor leukocyte engraftment, and the time window for such engraftment. MATERIALS AND METHODS: Hematologic toxicity of busulfan was assessed in C57BL6 mice after single nonmyeloablative doses of intraperitoneal busulfan ranging from 1 to 40 mg/kg by serial complete blood counts monitored up to 40 days. The level of donor engraftment attainable after nonmyeloablative busulfan was determined by infusion of 20 million congenic murine bone marrow nucleated cells (BMNC) following 5 to 40 mg/kg of busulfan. To determine the effects of delayed HSC infusions, BMNCs were infused 1, 10, 15, and 20 days after a single dose of 10 mg/kg of busulfan. RESULTS: Busulfan doses from 1 to 40 mg/kg produced hematologic toxicity that was most pronounced in the 2nd to 3rd week. In transplantation experiments, dose-dependent donor leukocyte engraftment was attained with levels >70% after only 20 mg/kg of busulfan. Similar levels of engraftment were achieved even when infusion of BMNCs was delayed up to 20 days after busulfan injection. CONCLUSION: Nonmyeloablative parenteral busulfan produced transient myelosuppressive effects, clinically relevant levels of engraftment, and an extended time window for HSC infusion in murine hosts.

The SLAP lesion as a reason for glenolabral cysts: a report of five cases and review of the literature.

INTRODUCTION: Cysts in the spinoglenoidal or supraglenoidal incisura can be a cause of compression of the suprascapular nerve. There is agglomerated appearance of these cysts in combination with SLAP lesions. Hypothesis is SLAP lesions can lead to cysts in this region and should be repaired. MATERIAL AND METHODS: MRI of five patients (all male, four 30-40 years, one 75 years) showed cysts in the supralabral region. All were in combination with lesions of the superior glenoidal labrum (Type II or more). RESULTS: In two cases, in addition to cyst resection, the SLAP lesion was also repaired and symptoms disappeared completely and no recurrent cyst was detected in postoperative MRI. Two patients without SLAP repair showed recurrent cystic formation in MRI with similar complaints compared to their preoperative status. One patient (75 years) was treated primarily by puncture and afterwards with open resection of the cyst. His outcome was good in terms of activities of daily living without major pain. CONCLUSIONS: Our results are based on the assumption that cysts in the region of the spinoglenoidal/supraglenoidal incisura can originate from SLAP lesions. If a patient is suspected of having cysts in this region, the question of a SLAP lesion should be clarified. SLAP lesions should be repaired to avoid relapse. Arthroscopic repair of SLAP lesion can lead to the disappearance of symptoms in younger patients. In older patients puncture or resection of the ganglion alone may be an adequate therapeutic strategy.

Perioperative intraperitoneal chemotherapy for peritoneal surface malignancy.

The treatment of peritoneal surface malignancy mainly focuses on diffuse malignant peritoneal mesothelioma, pseudomyxoma peritonei from appendiceal cancer, and peritoneal dissemination from gastrointestinal and ovarian cancers. Cancer progression causes peritoneal implants to be distributed throughout the abdominopelvic cavity. These nodules plus the ascitic fluid result in abdominal distension. As the disease progresses, these tumors cause intestinal obstruction leading to debilitating symptoms and a greatly impaired quality of life. In the past, the prognosis of patients with peritoneal surface malignancy was regarded dismal and cure was not an option. Recently, cytoreductive surgery combined with perioperative intraperitoneal chemotherapy has shown an improved survival in selected patients with this disease. To date, multiple different treatment regimens of perioperative intraperitoneal chemotherapy have been used. This review focuses on the perioperative intraperitoneal chemotherapy currently in use in conjunction with cytoreductive surgery for the treatment of peritoneal surface malignancy at the Washington Cancer Institute.

Hypothesized predictors of patient-physician trust and distrust in the elderly: implications for health and disease management.

This study notes the differences between trust and distrust perceptions by the elderly as compared with younger populations. Given the importance of trust and distrust in compliance, changing behaviors, and forming partnerships for both health and disease management, it is necessary to be able to measure patient-doctor trust and distrust (PDTD). Following recent conceptualizations on trust and distrust as coexistent states, this study hypothesizes predictors of PDTD. We are proposing that these predictors form the basis for designing, developing and validating a PDTD scale (PDTDS). It is important to capture the trust-distrust perceptions of older patients as they confront the complexities and vulnerabilities of the modem healthcare delivery system. This is necessary if we are to design interventions to change behaviors of both the healthcare provider and the older patient.

Hematopoietic stem cell transplantation prevents diabetes in NOD mice but does not contribute to significant islet cell regeneration once disease is established.

The treatment of type I diabetes by islet cell transplantation, while promising, remains restricted due to the incomplete efficacy and toxicity associated with current immunosuppression, and by limited organ availability. Given reports suggesting bone marrow derived stem cell plasticity, we sought to determine whether such cells could give rise to pancreatic islet cells in vivo. In the context of autoimmune diabetes, we transplanted unfractionated bone marrow from beta-gal trangenic donor mice into NOD mice prior to, at, and two weeks beyond the onset of disease. Successful bone marrow engraftment before diabetes onset prevented disease in all mice and for 1 year after transplant. However, despite obtaining full hematopoietic engraftment in over 50 transplanted mice, only one mouse became insulin independent, and no beta-Gal positive islets were detected in any of the mice. To test whether tolerance to islets was achieved, we injected islets obtained from the same allogeneic donor strain as the hematopoietic cells into 4 transplant recipients, and 2 had a reversion of their diabetes. Thus allogeneic bone marrow transplantation prevents autoimmune diabetes and tolerizes the recipient to donor islet grants, even in diabetic animals, yet the capacity of bone marrow derived cells to differentiate into functional islet cells, at least without additional manipulation, is limited in our model.

Avoiding carcinogen exposure with intraperitoneal paclitaxel.

PURPOSE/OBJECTIVES: Diethylhexylphthalate (DEHP) is a lipid-soluble plasticizer commonly used in the manufacture of polyvinyl chloride- (PVC-) based plastics. Previous studies have documented the leaching of DEHP from PVC-based containers and extension sets during the IV administration of paclitaxel. DESIGN: Study of the leaching of DEHP from infusion bags and peritoneal dialysis solution transfer sets and clinical study of DEHP was proposed. SETTING: The experiments were performed in a laboratory with plastic ware normally used for intraperitoneal chemotherapy delivery. SAMPLE: Samples were taken from fluids that had been in contact with the plastic ware. Also, blood, peritoneal fluid, and urine were collected from a patient. METHODS: In a controlled laboratory environment, the authors used an established high-performance liquid chromatography assay to determine the rate and extent of DEHP leaching from infusion bags and in the solution transfer set used for early postoperative intraperitoneal chemotherapy (EPIC) administration of paclitaxel. Paclitaxel was tested at a concentration of 40 mg/L to simulate the median dose used for EPIC. In a single patient receiving 34 mg paclitaxel in 1 liter of 1.5% dextrose peritoneal dialysis solution (Dianeal), the presence and concentration of DEHP in samples of peritoneal fluid and urine were determined during the first 24-hour EPIC administration. MAIN RESEARCH VARIABLES: DEHP levels in fluids exposed to plastic ware and in the patients blood, peritoneal fluid, and urine were determined. FINDINGS: The in vitro studies showed that a solution of 40 mg paclitaxel dissolved in a 1 liter bag of Dianeal resulted in the extraction of approximately 26 mg DEHP over 24 hours. Approximately 2 mg DEHP was leached during the first hour and approximately 1 mg per hour over the following 23 hours. Equivalent results were obtained when 20 mg paclitaxel was dissolved in a 500 ml bag of 6% hetastarch (Hespan) with a leaching of approximately 13 mg DEHP in 24 hours. Using the same paclitaxel concentration, the chronic ambulatory peritoneal dialysis solution transfer tubing with a total capacity of 10 ml produced approximately 2 mg DEHP over 24 hours, of which approximately 0.5 mg was produced during the first four hours. Samples from a single patient showed that immediately prior to administration, a 1 liter bag of Dianeal containing 34 mg paclitaxel had about 3.3 mg DEHP. Approximately 3% (110 mcg) of unchanged DEHP was recovered from the peritoneal fluid at 24 hours. Total DEHP excreted in urine over the 24-hour period was approximately 900 mcg (27%). CONCLUSION: This study showed that the carcinogen DEHP is leached after preparation of paclitaxel from PVC-based containers and DEHP constantly accumulates in the solution transfer tubing. IMPLICATIONS FOR NURSING: Unless precautionary steps are taken, DEHP can be transferred to patients receiving intraperitoneal paclitaxel. Steps to minimize patient exposure to DEHP during EPIC with paclitaxel are necessary. In the ideal situation, no DEHP-containing plastic should be used for chemotherapy delivery. If that is not possible, (a) paclitaxel solution should be administered as soon as possible after preparation by the pharmacy, (b) infusion should proceed as rapidly as possible via the Tenckhoff catheter, and (c) the Tenckhoff catheter and extension tubing should be cleared by draining ascites fluid through these tubes prior to subsequent intraperitoneal infusions.

Cloning and functional analysis of the rhesus macaque ABCG2 gene. Forced expression confers an SP phenotype among hematopoietic stem cell progeny in vivo.

Hematopoietic cells can be highly enriched for repopulating ability based upon the efflux of the fluorescent Hoechst 33342 dye by sorting for SP (side population) cells, a phenotype attributed to expression of ABCG2, a member of the ABC transporter superfamily. Intriguingly, murine studies suggest that forced ABCG2 expression prevents hematopoietic differentiation. We cloned the full-length rhesus ABCG2 and introduced it into a retroviral vector. ABCG2-transduced human peripheral blood progenitor cells (PBPCs) acquired the SP phenotype but showed significantly reduced growth compared with control. Two rhesus macaques received autologous PBPCs split for transduction with the ABCG2 or control vectors. Marking levels were similar between fractions with no discrepancy between bone marrow and peripheral blood marking. Analysis for the SP phenotype among bone marrow and mature blood populations confirmed ABCG2 expression at levels predicted by vector copy number long term, demonstrating no block to differentiation in the large animal. In vitro studies showed selective protection against mitoxantrone among ABCG2-transduced rhesus PBPCs. Our results confirm the existence of rhesus ABCG2, establish its importance in conferring the SP phenotype, suggest no detrimental effect of its overexpression upon differentiation in vivo, and imply a potential role for its overexpression as an in vivo selection strategy for gene therapy applications.