In vivo toxicity and pharmacokinetic features of B43 (anti-CD19)-genistein immunoconjugate in nonhuman primates

B43 (anti-CD19)-genistein immunoconjugate targets genistein, a naturally occurring protein tyrosine kinase-inhibitory isoflavone to the membrane-associated antiapoptotic CD19-LYN complexes and triggers apoptotic cell death. In this preclinical study, the toxicity profiles of B43-genistein as well as unconjugated genistein were evaluated in cynomolgus monkeys. B43-genistein and genistein were administered either as single bolus injections or daily injections for 5-10 consecutive days via the i.v. route to monkeys. Neither genistein nor B43-genistein was toxic to cynomolgus monkeys, and no test article-related histopathological lesions were found in any of the two genistein-treated or five B43-genistein-treated cynomolgus monkeys. B43-genistein showed a favorable pharmacokinetics in monkeys, with a plasma half-life of 10-23 h. Plasma samples from B43-genistein-treated monkeys elicited potent and CD19 antigenspecific antileukemic activity against human CD19+ leukemia cells in vitro. To our knowledge, this is the first preclinical toxicity and pharmacokinetic study of a tyrosine kinase inhibitor-containing immunoconjugate in nonhuman primates.

Human mucopolysaccharidosis IIID: clinical, biochemical, morphological and immunohistochemical characteristics

Mucopolysaccharidosis IIID (MPS IIID) is one of the rarest of the MPS-III syndromes. To date, the clinical manifestations of 10 patients have been reported, the deficient N-acetylglucosamine 6-sulfatase (G6S) enzyme has been purified, and the G6S gene has been cloned, sequenced and localized. However, morphological manifestations of this condition have not been reported and the pathogenesis of the severe neurological deficits remains an enigma. In this paper we describe and correlate the clinical, biochemical and pathological observations for 2 cases of MPS IIID. We used monoclonal antibodies against heparan sulfate (HS) and GM2-ganglioside, thin layer chromatography, mass spectrometry, and morphological techniques to demonstrate the nature and the distribution of the uncatabolized substrates. The majority of the cells in various tissues showed morphological changes expected with lysosomal storage of HS. The central nervous system (CNS) was most severely affected because of the secondary storage of GM2 and GM3 gangliosides in addition to the primary accumulation of HS. The extent as well as the distribution of the diverse storage materials varied within and among different neurons as observed in MPS-III A, B, and C syndromes. This study supports the hypothesis that the neurological dysfunction and neurodegeneration common to the Sanfilippo syndromes is, in part, due to the secondary metabolic perturbations induced by HS accumulation.

Unresected stage III non-small-cell lung cancer. Provincial Lung Cancer Disease Site Group

GUIDELINE QUESTIONS

1) What is the role of different schedules or doses of radiotherapy in patients with unresected, clinical or pathological, stage III non-small-cell lung cancer (NSCLC)? 2) Does chemotherapy combined with radiotherapy provide improved survival compared with radiotherapy alone in patients with unresected NSCLC?

OBJECTIVE

To make recommendations about the role of chemotherapy and radiotherapy in the treatment of unresected stage III NSCLC.

OUTCOMES

Survival is the primary outcome of interest. Quality of life is a secondary outcome.

PERSPECTIVE (VALUES)

Evidence was selected and reviewed by 5 members of the Provincial Lung Cancer Disease Site Group (Lung DSG) of the Ontario Cancer Treatment Practice Guidelines Initiative. The Lung DSG comprises medical and radiation oncologists, pathologists, surgeons, epidemiologists, a psychologist and a medical sociologist. No community representative participated in the development of this guideline.

QUALITY OF EVIDENCE

Two meta-analyses were available for review. The specific analysis of interest examined the role of combined chemotherapy plus radiotherapy v. radiotherapy alone in locally advanced disease. The first meta-analysis included combined data from 22 randomized controlled (RCTs) involving a total of 3033 patients. The second included combined data from 14 RCTs involving a total of 2589 patients. Also reviewed were 4 RCTs of radiotherapy alone, 1 trial of combined chemotherapy and radiotherapy that was not included in the meta-analysis, 4 abstracts of studies of combined chemotherapy and radiotherapy, and 4 trials examining the role of hyperfractionated radiotherapy.

BENEFITS

In the first meta-analysis, an overall benefit was detected at 2 years for the use of combined chemotherapy and radiotherapy. A hazard ratio of 0.90 (p = 0.006), or a 10% reduction in the risk of death, translated into an absolute benefit of 3% at 2 years and 2% at 5 years. A subgroup analysis of cisplatin-based chemotherapy plus radiotherapy versus radiotherapy alone demonstrated a 13% reduction in the risk of death in the combined treatment arm (pooled hazard ratio 0.87, 95% confidence interval [CI] 0.79-0.96), for an absolute benefit of 4% at 2 years. In the second meta-analysis, there was a 13% reduction in the risk of death in the combined therapy arm at 2 years (pooled relative risk [RR] 0.87, 95% CI 0.81-0.94) and a 17% reduction at 3 years (pooled RR 0.83, 95% CI 0.77-0.90). Subgroup analysis of cisplatin-based chemotherapy plus radiotherapy versus radiotherapy alone showed similar results: a 15% reduction in the risk of death in the combined therapy arm at 2 years (pooled RR 0.85, 95% CI 0.79-0.92) and a 19% reduction at 3 years (pooled RR 0.81, 95% CI 0.74-0.88).

PRACTICE GUIDELINE

For patients with unresected stage III NSCLC, the combination of cisplatin-based chemotherapy and radical radiotherapy provides a survival benefit compared with radiotherapy alone. This guideline is based on high-quality evidence from 2 meta-analyses of RCTs. Patients with good performance status (Eastern Cooperative Oncology Group [ECOG] 0-1) and minimal weight loss (less than 5% in the preceding 3 months) have been shown to have a survival benefit from treatment with combined chemotherapy and radiotherapy and should be considered for this type of treatment approach (see section V). For these patients, thoracic irradiation of 60 Gy in 30 fractions over 6 weeks, in combination with cisplatin-based chemotherapy, should be recommended as a treatment option. The patient and physician should discuss fully the benefits, limitations and toxic effects of therapy. Patients not meeting these criteria are not candidates for combined therapy; those experiencing symptoms amenable to treatment should receive palliative thoracic irradiation. At this time, hyperfractionated radiotherapy is not recommended outside of the context of a clinical trial. (ABSTRACT TRUNCATED)

A complete YAC contig and cosmid interval map covering the entirety of human Xq21.33 to Xq22.3 from DXS3 to DXS287

We have produced a physical map that covers the entirety of Xq21.33 to Xq22.3, from DXS3 to DXS287, approximately 15-17 Mb of the proximal long arm of the human X chromosome. This region has already been shown to contain a number of genes involved in genetic disorders, some of which have yet to be cloned. The physical map consists of a contig of 420 yeast artificial chromosome (YAC) clones ordered with respect to 142 DNA markers, approximately one probe every 110 kb. Forty-three YACs from across the contig have been used to isolate 2019 cosmids that have been mapped into 87 intervals, and 667 of these clones are positive for at least 1 single-copy marker. These YACs and cosmids have been used to confirm data from other published contigs that map to the region. The physical map described here constitutes the first step toward a complete transcriptional map of the region.

Functional and metabolic consequences of sarcopenia

The capacity of older men and women to adapt to regularly performed exercise has been demonstrated by many laboratories. Aerobic exercise results in improvements in functional capacity and reduced risk of developing type II diabetes in the elderly. High intensity resistance training (above 60% of the 1 repetition maximum) causes large increases in strength in the elderly, and resistance training significant increases muscle size. Resistance training also significantly increases energy requirements and insulin action of the elderly. We recently demonstrated that resistance training has a positive effect on multiple risk factors for osteoporotic fractures in previously sedentary post-menopausal women. Because the sedentary lifestyle of individuals in a long-term care facility may exacerbate losses of muscle function, we applied this same training program to frail, institutionalized elderly men and women. In a population of 100 nursing home residents, a randomly assigned high intensity strength training program resulted in significant gains in strength and functional status. In addition, spontaneous activity, measured by activity monitors, increased significantly in those participating in the exercise program; there was no change in the sedentary control group. Before the strength training intervention, the relationship of whole-body potassium and leg strength was relatively weak (r2 = 0.29, P < 0.001), indicating that in very old persons muscle mass is an important but not the only determiner of functional status. Thus exercise may minimize or reverse the syndrome of physical frailty prevalent among very old individuals. Because of their low functional status and high incidence of chronic disease, there is no segment of the population that can benefit more from exercise training than the elderly.

Development of a rural oncology nursing conference: proposal through implementation

PURPOSE/OBJECTIVES

To discuss the funding/implementation process of a continuing nursing education program focusing on cancer care delivery in the rural setting.

DATA SOURCES

Books, published articles, and personal experience.

DATA SYNTHESIS

Producing a rural oncology conference required a needs assessment identification of funding sources, collaboration of a variety of stakeholders, dedicated implementation, and outcome evaluation.

CONCLUSIONS

The strategies for designing and funding this rural program were successful. The conference was received enthusiastically by rural homecare, nursing home, and administrative nurses. More continuing education of rural nurses is needed because many patients with cancer ore returning home sooner and remaining home longer.

IMPLICATIONS FOR NURSING PRACTICE

Individual Oncology Nursing Society chapters can make a difference in the nursing care of their communities and can obtain financial support for their projects. Urban nurses can mentor and network with their rural colleagues by offering their services proactively. With the changing complexion of healthcare funding, it is imperative that nurses at all levels learn to access the funding sources available for the enhancement of community nursing services.

Pharmacokinetic features, immunogenicity, and toxicity of B43(anti-CD19)-pokeweed antiviral protein immunotoxin in cynomolgus monkeys

We studied the pharmacokinetic features, immunogenicity, and toxicity of B43-pokeweed antiviral protein (PAP) immunotoxin in 13 cynomolgus monkeys. The disposition of B43-PAP in two monkeys, when administered as a single i.v. bolus dose, was characterized by a slow clearance (1-2 ml/h/kg) with a very discrete peripheral distribution. B43-PAP was retained and distributed largely in the blood as the sole compartment with no significant equilibration with the extravascular compartment. The circulating B43-PAP immunotoxin detected in monkey plasma samples by ELISA and protein immunoblotting was both immunoreactive with, and active against, human leukemic cells in vitro. In systemic immunogenicity and toxicity studies, which involved 11 cynomolgus monkeys, each monkey received a total of seven i.v. doses of B43-PAP at a specific dose level of the dose escalation schedule. B43-PAP-treated monkeys mounted a dose-dependent humoral immune response against both the mouse IgG and PAP moieties of the immunotoxin. When administered i.v. either on an every-day or every-other-day schedule, B43-PAP was very well tolerated, with no significant clinical or laboratory signs of toxicity at total dose levels ranging from 0.007 to 0.7 mg/kg. A transient episode of a mild capillary leak with a grade 2 hypoalbuminemia and 2+ proteinuria was observed at total dose levels equal to or higher than 0.35 mg/kg. At total dose levels of 3.5 and 7.0 mg/kg, B43-PAP caused dose-limiting renal toxicity due to severe renal tubular necrosis. The present study completes the preclinical evaluation of B43-PAP and provides the basis for its clinical evaluation in children with therapy-refractory B-lineage acute lymphoblastic leukemia.

Management of thromboembolic disease associated with pregnancy

Our objective was to identify practice patterns of members of the Society of Perinatal Obstetricians with regard to the management of thromboembolic disease in pregnant women. We sent survey-questionnaires to members of the Society of Perinatal Obstetricians and requested information on antepartum and postpartum management of four clinical case scenarios. We also requested information on the evaluation of hypercoagulability and on the dosing and monitoring of heparin during pregnancy. We received 515 responses after a single mailing (47%). Most respondents utilize some form of anticoagulation in pregnant women with a history of thromboembolic disease, although there was variation in the duration and intensity of anticoagulation. Nearly all respondents (96%) use full anticoagulation with heparin for pregnant women with prosthetic heart valves. Most respondents evaluate pregnant women for hypercoagulable disorders who present with a thromboembolism or have a history of thromboembolic disease. There is considerable variation with respect to the dosing and monitoring of heparin therapy during pregnancy. Although most SPO members recommend anticoagulation in pregnant women with a history of venous thromboembolism, there is marked variation in the intensity, duration, and monitoring of heparin therapy in pregnant patients. Randomized prospective studies are needed to establish accurate recurrence risks and to evaluate the efficacy of anticoagulation in pregnant women with a history of venous thromboembolism.

Flosequinan in chronic heart failure: how is exercise capacity improved?

OBJECTIVE

Diuretics, angiotensin converting enzyme inhibitors and digoxin have become "standard" triple therapy for many patients with chronic cardiac failure. Flosequinan increases exercise duration and improves symptoms when added to standard triple therapy. Despite intensive study, the clinical pharmacology of flosequinan remains uncertain.

SETTING

The University Hospital of Wales, a Regional Cardiac Centre.

PATIENTS

Twenty four patients with chronic heart failure who remained symptomatic despite standard therapy including ACE inhibitors.

METHODS

A double-blind placebo-controlled parallel group study of 100 mg daily of flosequinan. We measured changes in exercise duration using cardiorespiratory exercise testing and changes in large artery distensibility using Doppler ultrasound.

RESULTS

Exercise duration after 8 weeks flosequinan treatment was significantly greater than following placebo treatment. The flosequinan-related increase in exercise duration (+14%) was associated with a significant reduction in VE/VCO2 slope (-16%). Brachial-radial pulse wave velocities were unaltered by flosequinan treatment.

CONCLUSIONS

Our results confirm that flosequinan improves exercise duration in patients with chronic heart failure. They suggest that this observed beneficial effect is independent of any change in large artery distensibility and that in the presence of ACE inhibitors, this improvement may be independent of any vasodilating action of flosequinan. Although this study confirms the beneficial symptomatic effects of flosequinan in chronic cardiac failure, clinical trials have subsequently demonstrated an overall increase in mortality in patients treated with 100 mg flosequinan daily. This has resulted in the withdrawal of flosequinan from routine clinical use.

Treatment of human B-cell precursor leukemia in SCID mice using a combination of the investigational biotherapeutic agent B43-PAP with cytosine arabinoside

Combined immunochemotherapy regimens using the investigational biotherapeutic agent B43(anti-CD19)-poke-weed antiviral protein (PAP) immunotoxin may offer an effective treatment for refractory B-cell precursor leukemias. The purpose of the present study was to explore and identify effective combinations of B43-PAP with standard chemotherapeutic drugs, including the anthracyclin doxorubicin, the epipodophyllotoxin etoposide, the nitrosurea carmustine, and the antimetabolite cytosine arabinoside. Here, we report that the B43-PAP plus cytosine arabinoside combination has potent antileukemic activity against human B-cell precursor leukemia in SCID mice and leads to 100% long-term event-free survival from an otherwise invariably fatal leukemia. Surprisingly, none of the other treatment protocols tested, including combinations of B43-PAP with carmustine, doxorubicin, or etoposide, proved more effective than B43-PAP alone.

Lack of a critical cardiac output and critical systemic oxygen delivery during low cardiac output in the third trimester in the pregnant sheep

OBJECTIVE

We sought to determine whether a critical cardiac output and oxygen delivery exist in normal pregnancy. We also sought to determine the role of fetoplacental oxygen demand on maternal oxygen transport variables in response to decreased maternal cardiac output.

STUDY DESIGN

We studied 10 adult female sheep, 5 nonpregnant and 5 pregnant. We placed a flow-directed thermodilution catheter in the pulmonary artery and a balloon-tipped catheter in the right atrium of the sheep. We also placed a catheter for pressure monitoring and blood sampling in the descending thoracic aorta in both the mother and fetus. We decreased maternal cardiac output by incremental inflation of the right atrial balloon. We measured maternal cardiac output by intravenous bolus thermodilution technique. We also measured maternal and fetal acid-base status and serum lactate concentrations. We calculated a variety of maternal cardiorespiratory variables, including systemic oxygen delivery, systemic oxygen consumption, and fractional whole body tissue oxygen extraction.

RESULT

The nonpregnant sheep displayed a critical cardiac output below which there was an abrupt decrease in oxygen consumption. In contrast, there was no critical level of cardiac output in the pregnant sheep. Maternal oxygen consumption was linearly dependent on cardiac output. Maximum fractional oxygen extraction was significantly lower in the pregnant sheep than in the nonpregnant sheep.

CONCLUSION

States of low cardiac output in the pregnant sheep are associated with a lack of a critical cardiac output; the flow-dependent oxygen consumption observed is the result of either an impairment in tissue oxygen extraction or some degree of metabolic arrest or a combination of both. If this unique cardiac output-oxygen consumption relationship is seen in human pregnancy, it could have significant implications in the care of the critically ill obstetric patient.

Body composition derived from whole body counting of potassium in growth hormone-deficient adults: a possible low intracellular potassium concentration

The validity of total body potassium (TBK) measurement in estimating fat mass and fat-free mass (FFM) in GHD adults was assessed by comparison with the reference technique of dual energy x-ray absorptiometry (DEXA). The TBK and FFM values determined by DEXA were used to calculate the potassium concentration per kg FFM in GH-deficient (GHD) adults and compared with standard values for normal subjects of 59.6 mmol for females and 66.4 mmol for males. There were considerable differences between predicted and measured TBK values for both males (3972 vs. 3577 mmol; P < 0.001) and females (2526 vs. 2277 mmol; P < 0.001). Similarly, the estimation of FFM and fat mass by TBK measurement was significantly inaccurate for both sexes compared to values determined by DEXA. These discrepancies may be accounted for by the lower calculated potassium concentrations compared with standard values for both males (56.2 vs. 66.4 mmol; P < 0.001) and females (53.1 vs. 59.6 mmol; P < 0.001). These observations suggest that caution should be exercised in the interpretation of TBK in GHD adults, and the reduced potassium concentrations would alleviate inaccuracies in the estimation of body composition. Secondly, the decreased intracellular potassium concentration of GHD adults may account for the decreased muscle strength and ease of fatigueability seen in GHD adults.

Reverse transcription-polymerase chain reaction detection of collagen transcripts in healing human wounds

The aim of this study was to analyse the expression of COl1A1, COl1A2 and COl3A1 in 6 mm diameter punch biopsies obtained from human wounds. Total RNA was isolated from biopsies taken from Sacrococcygeal pilonidal sinus excision cavities at weekly intervals between surgery and clinical closure. cDNAs were generated from the RNA using reverse transcriptase and polymerase chain reaction (PCR) amplifications performed with oligonucleotide primer pairs specific for regions of the COl1A1, COl1A2 and COl3A1 genes. The expression of these three genes was demonstrated throughout the course of healing on 36 biopsies taken from nine patients between surgery and clinical closure. Amplification bands demonstrated on cDNAs generated from 6 mm diameter biopsies were comparable in intensity and specificity with those generated from 50 mg excised scar tissue and cultured fibroblasts. The RT-PCR technique described here allows the rapid 'routine' detection of specific gene expression in 6 mm biopsies obtained from healing wounds.