The cost effectiveness of prenatal ultrasound screening for trisomy 21

OBJECTIVES: The cost-effectiveness of opportunistic nuchal translucency ultrasound screening in pregnancy was compared with alternative screening strategies for trisomy 21 in Australia. METHODS: A decision analytic model was used of various pregnancy screening strategies based on a systematic review of the literature on the effectiveness of nuchal translucency ultrasound and serum screening and costs based on current reimbursement fees. The model included the likelihood and cost of terminations after diagnostic testing and the associated risk of fetal loss. All prices are in 2001 Australian dollars. RESULTS: With a twenty percentage point difference in detection rate, the incremental cost for a combination of nuchal translucency and serum screening with age in the first trimester compared with maternal serum screening in the second trimester was 105,484 dollars per extra case detected and 374,779 dollars per live trisomy 21 birth avoided. Serum screening in the second trimester had an incremental cost per extra case detected of between 61,700 dollars and 117,100 dollars per extra live birth avoided when compared with no screening. CONCLUSIONS: The cost-effectiveness of ultrasound screening for trisomy 21 would appear to be more attractive if it were done at the same time as current dating ultrasound. Any funding mechanism for screening should take this strategy into account by incorporating, as far as possible, provision of nuchal translucency screening into existing services provided in early pregnancy.     

Toxicokinetics of three polychlorinated biphenyl technical mixtures in rainbow trout (Oncorhynchus mykiss)

Accumulation and depuration parameters of polychlorinated biphenyls (PCBs) in fish have been reported only for a few congeners. As well, there is little information on the ability of fish to biotransform PCBs. To address these issues, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to dietary concentrations of three Aroclor mixtures (1248, 1254, 1260) in food for 30 d followed by an additional 160 d of nonspiked food at 8 degrees C. Accumulation, depuration, and potential biotransformation of 92 PCB congeners were assessed. Half-lives (t1/2) of PCB congeners ranged from 79 to 182 d, assimilation efficiencies ranged from 40 to 50% and biomagnification factors (BMF) ranged from 2.9 to 6.9. No evidence of significant biotransformation of any PCB congeners was found. All 92 congeners fell on the same t1/2 to Kow relationship as 16 preselected PCB congeners previously shown to persist in fish and no hydroxylated PCB metabolites (OH-PCBs) were detected in the plasma after 30 d of exposure. These findings suggest that OH-PCBs observed in feral fish may be accumulated from sources other than internal metabolism of the parent congeners, at least for juvenile fish at cool temperatures. Because t1/2s in this experiment were slower than t1/2s reported in other work, water temperature also may be an important factor in determining the t1/2s of all PCB congeners in fish.     

Dependence of human forearm skin postocclusive reactive hyperemia on occlusion time

INTRODUCTION: Human postocclusive forearm skin reactive hyperemia is not only a potential means of identifying early signs of cardiovascular diseases, it can also be used in the assessment of local microvascular response to topically applied compounds on skin. The method is not fully characterized. In this study, we investigated the influence of occlusion time on postocclusive forearm skin reactive hyperemia using laser Doppler fluximetry (LDF). METHODS: Twenty healthy male volunteers were studied on three separate days (at least 24 h apart) via a randomized design. Volunteers were studied in a supine position while fasted. Laser Doppler probes were placed on the volar surface of the antebrachium. In preliminary studies, 3 min of upper arm blood flow occlusion at suprasystolic pressure was found to be the upper limit of tolerability. Subsequently, volunteers were randomized to receive 1, 2, or 3 min occlusion on 3 different days. Skin blood flux was measured before, during, and after occlusion using LDF. The primary outcome calculated was maximal change in skin blood flux before and after occlusion, expressed in arbitrary units (AU). RESULTS: Skin blood flux changes (mean+/-S.E.M.) after 1, 2, and 3 min occlusion period were 15.39+/-1.27 AU, 24.84+/-1.62 AU, and 32.14+/-1.73 AU, respectively. Using repeated-measures analysis of variance (ANOVA), significant difference (P<.05) in skin blood flux changes were revealed between these three occlusion durations, where 3 min occlusion produced significantly greater in skin blood flux occlusion change compared to 1 and 2 min occlusion. DISCUSSION: Three minutes of occlusion produces the greater postocclusive reactive hyperemia. It is recommended that studies using postocclusive forearm skin reactive hyperemia should occlude the forearm for at least 3 min.     

Phase 2 trial of BCNU plus irinotecan in adults with malignant glioma

In preclinical studies, BCNU, or 1,3-bis(2-chloroethyl)-1-nitrosourea, plus CPT-11 (irinotecan) exhibits schedule-dependent, synergistic activity against malignant glioma (MG). We previously established the maximum tolerated dose of CPT-11 when administered for 4 consecutive weeks in combination with BCNU administered on the first day of each 6-week cycle. We now report a phase 2 trial of BCNU plus CPT-11 for patients with MG. In the current study, BCNU (100 mg/m2) was administered on day 1 of each 6-week cycle. CPT-11 was administered on days 1, 8, 15, and 22 at 225 mg/m2 for patients receiving CYP3A1- or CYP3A4-inducing anticonvulsants and at 125 mg/m2 for those not on these medications. Newly diagnosed patients received up to 3 cycles before radiotherapy, while recurrent patients received up to 8 cycles. The primary end point of this study was radiographic response, while time to progression and overall survival were also assessed. Seventy-six patients were treated, including 37 with newly diagnosed tumors and 39 with recurrent disease. Fifty-six had glioblastoma multiforme, 18 had anaplastic astrocytoma, and 2 had anaplastic oligodendroglioma. Toxicities (grade > or =3) included infections (13%), thromboses (12%), diarrhea (10%), and neutropenia (7%). Interstitial pneumonitis developed in 4 patients. Five newly diagnosed patients (14%; 95% CI, 5%-29%) achieved a radiographic response (1 complete response and 4 partial responses). Five patients with recurrent MG also achieved a response (1 complete response and 4 partial responses; 13%; 95% CI, 4%-27%). More than 40% of both newly diagnosed and recurrent patients achieved stable disease. Median time to progression was 11.3 weeks for recurrent glioblastoma multiforme patients and 16.9 weeks for recurrent anaplastic astrocytoma/ anaplastic oligodendroglioma patients. We conclude that the activity of BCNU plus CPT-11 for patients with MG appears comparable to that of CPT-11 alone and may be more toxic.     

Quantitative assessment of tumor vasculature and response to therapy in kaposi's sarcoma using functional noninvasive imaging

Two noninvasive methods, thermography and laser Doppler imaging (LDI), were assessed for their ability to quantitatively assess parameters of vascularity in lesions of HIV-associated Kaposi's sarcoma (KS). Thermography and LDI images of a representative KS lesion were recorded in 16 patients and compared to normal skin either adjacent to the lesion or on the contralateral side. Eleven of the 16 patients had greater than 0.5 degrees C increased temperature and 12 of the 16 patients had increased flux (measured by LDI) as compared to normal skin. There was a strong correlation between these two parameters (R = 0.81, p < 0.001). In ten patients, measurements were obtained prior to therapy and after receiving a regimen of liposomal doxorubicin and interleukin-12. After 18 weeks of therapy, temperature and blood flow of the lesions were significantly reduced from the baseline (p = 0.004 and 0.002 respectively). These techniques hold promise to assess physiologic parameters in KS lesions and their changes with therapy.     

Intraamniotic endotoxin increases lung antioxidant enzyme activity in preterm lambs

Proinflammatory stimulation resulting from intraamniotic endotoxin improves lung function, increases surfactant protein mRNA expression and protein content, increases alveolar and lung saturated phosphatidylcholine pools, and accelerates lung morphometric maturation in fetal sheep. The mechanism for induction of lung maturation does not involve an increase in fetal cortisol. The effect of endotoxin on the maturation of a different lung system, the antioxidant enzyme (AOE) system, has not been examined. Therefore, we hypothesized that intraamniotic endotoxin would produce acceleration of AOE activity in fetal sheep at similar doses and schedule of administration to those producing lung functional and surfactant maturation. In a dose-response study, intraamniotic injections of 1, 4, 20, or 100 mg of Escherichia coli 055:beta5 endotoxin were administered 7 d before preterm delivery of sheep at 125 d gestation. In a study examining time interval of administration before delivery, 20 mg of endotoxin was injected at either 1-, 2-, 4-, 7-, or 15-d intervals before preterm delivery at 125 d. Doses of 1-100 mg of endotoxin produced significant increases in glutathione peroxidase activity; doses of 4-100 mg significantly increased catalase activity, whereas doses of 20-100 mg resulted in significant increases in total superoxide dismutase activity. Glutathione peroxidase activity was elevated within 2 d, whereas superoxide dismutase was increased by 4 d and catalase activity increased by 7 d after endotoxin. No AOE increases were sustained for 15 d. Endotoxin increased fetal lung AOE activity at similar dosing amounts and intervals to those producing maturation of lung function and surfactant. Thus, mechanisms involving proinflammatory stimulation, unrelated to glucocorticoid hormones, can induce maturation of the AOE system of the fetal lung.     

Should cholecystectomy be performed concomitantly with splenectomy in children with sickle-cell disease?

Splenectomy and cholecystectomy are among the common surgical procedures required to treat complications of sickle-cell disease (SCD), and when performed separately have been shown to be safe and effective. To determine whether cholecystectomy be performed concomitantly with splenectomy (CSC) in these children, we studied a total of 130 children who underwent splenectomy for various hematologic diseases at our hospital. The most common indication was SCD. Ninety-nine patients (86 SCD and 13 sickle-B-thalassemia) underwent splenectomy and 19 (19.2%) (12 males and 7 females, mean age 13.4 years [7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]) underwent CSC due to concomitant gallstones, which were asymptomatic in 13 cases. Those with an admission hemoglobin (Hb) of less than 10 g/dl were transfused with packed erythrocytes to increase their Hb to 10-12 g/dl and their hematocrit to 30%-40%. All patients received intravenous hydration the night before surgery at a rate of 1(1/2) times their maintenance rate, which was continued postoperatively until they were able to tolerate adequate oral fluid intake. The indications for splenectomy in those who had CSC were: acute splenic sequestration crisis in 12, splenic abscess in 3, hypersplenism in 2, and massive splenic infarction in 2. Eight patients had massive splenomegaly (spleen weight >1 kg). In 7 cases CSC was done through a left-upper-quadrant (LUQ) transverse incision, in the remaining 12 through an upper midline incision. There was no mortality and only 2 patients developed postoperative complications; a wound infection in 1 and a hematoma in the splenic bed in another. With good perioperative management, CSC is both safe and effective for children with SCD. Both procedures can be performed safely through an upper midline or a LUQ transverse incision, even in the presence of massive splenomegaly.