Reperfusion rates following intra-arterial thrombolysis for acute ischemic stroke: the influence of the method for alteplase delivery.

BACKGROUND AND PURPOSE: Because alteplase does not penetrate thrombus effectively, this study examined whether a method thought to maximize surface distribution of alteplase on the offending thrombus during IATT would result in greater reperfusion rates in acute ischemic stroke. MATERIALS AND METHODS: Clinical information, arteriograms, and CT scans following treatment from 85 consecutive patients who underwent IATT by using alteplase within 6 hours of stroke symptom onset were reviewed. Alteplase was delivered through a microcatheter embedded within the thrombus at 1 mg per minute in all cases, and the delivery never exceeded 100 mg of alteplase. Patients who underwent microcatheter contrast injections confirming that alteplase surrounded the thrombus were compared with patients who did not. RESULTS: Greater than 50% vascular territory reperfusion occurred in 82.2% of patients who underwent IATT with the intention of optimizing alteplase delivery versus 30.0% in patients without this intention (P < .0001, Pearson correlation) with an odds ratio of 15.8 based on nominal regression analysis. Hemorrhagic complication rates between methods were similar. The mRS at 1-3 months, infarct volume, change in NIHSS score by 24 hours, and hospital discharge were positively affected by optimizing alteplase delivery. CONCLUSIONS: A method that intends to evenly distribute alteplase around a thrombus resulted in better reperfusion rates and clinical outcomes compared with methods without this intention. Other predictors positively influencing reperfusion included the presence of slow antegrade flow distal to the clot, earlier time to treatment, lower presenting NIHSS score, and proximal occlusion site.

Carbon sequestration and estimated carbon credit values as measured using 13C labelling and analysis by means of an optical breath test analyser.

Recent developments in optical systems (isotope-selective non-dispersive infrared spectrometry) for breath testing have provided a robust, low-cost option for undertaking (13)C analysis. Although these systems were initially developed for breath testing for Helicobacter pylori, they have an enormous potential as a soil science research tool. The relatively low cost of the equipment, US$15,000-25,000, is within the research budgets of most institutes or universities. The simplicity of the mechanisms and optical nature mean that the equipment requires relatively low maintenance and minimal training. Thus methods were developed to prepare soil and plant materials for analysis using the breath test analyser. Results that compare conventional mass spectrometric methods with the breath test analyser will be presented. In combination with simple (13)C-plant-labeling techniques it is possible to devise methods for estimating carbon sequestration under different agronomic management practices within a short time frame. This enables assessment of the carbon credit value of a particular agronomic practice, which can in turn be used by policy makers for decision-making purposes. For global understanding of the effect of agricultural practices on the carbon cycle, data are required from a range of cropping systems and agro-ecological zones. The method and the approach described will enable collection of hard data within a reasonable time.

Growth parameters and predictors of growth in short children with and without growth hormone (GH) deficiency treated with human GH: a randomized controlled study.

Seventy-seven prepubertal short children with heights below the third centile for age and gender were divided into three groups according to their peak GH response to clonidine and insulin provocation. Group (I) included 30 children with peak GH response < 7 micrograms/l, group (II) included 19 children, with GH peak response between 7 and 10 micrograms/l, and group (III) included 24 children with GH peak > 10 micrograms/l. Each group was divided into two subgroups, a and b. Subgroups (I)b, (II)a and (III)b were treated daily for 1 year with subcutaneous recombinant human growth hormone (GH) 15 U/m2/week, and group (I)a was treated with GH (30 U/m2/week). Before initiation of treatment, the chronological age, the height standard deviation score (HtSDS), and the bone age delay did not differ among the study subgroups. The height growth velocity (GV) and insulin-like growth factor-I concentrations were significantly higher in group (III), with normal GH response to provocation, compared to those for group (I) with GH deficiency. All the children had normal thyroid function and normal glucose tolerance. CT examination of the hypothalamic-pituitary area revealed a picture of empty sella (either partial or complete) in 35 per cent of the children in group (I) and 21 per cent of children in group (II). After 1 year of GH therapy, the HtSDS, GV, and IGF-I concentrations increased significantly in the four subgroups treated with GH compared to their pretreatment values and to their controls. All the children in group (I) were responders (increment in GV of 2 cm2/year above the pretreatment GV), of the nine subjects treated in group (II)a, one child was a non-responder and of the 12 children in group (III)a three children were non-responders. GV was non-significantly higher in group (I)a (30 U/m2/week) v. group (I)b (15 U/m2/week). GV of children in groups (I)b, with abnormal GH response to provocation, was significantly higher than GV of children in group (III)a. Bone age advanced by less than 1 year in the treated groups (0.84 +/- 0.14 years) v. the untreated groups (0.73 +/- 0.3 years). None of the children had impaired glucose tolerance or abnormal thyroid function after 1 year of GH therapy. In all the treated children, GV after 1 year of GH treatment was correlated significantly with the pretreatment GV (r = -0.63, P < 0.01), peak GH response to provocation (r = -0.59, P < 0.01), IGF-I concentration (r = -0.54, P < 0.01), and positively with the GH dose (r = 0.589, P < 0.01). In group (III) children, with normal GH reserve, GV correlated significantly with the pretreatment GV (r = -0.48, P < 0.01) and negatively with the GH peak response to provocation (r = -0.25, P < 0.05). In conclusion, GH therapy improved GV of children growing along or parallel to the 3rd centile, irrespective of their GH response to provocation, without untoward effect on skeletal maturation, thyroid function or glucose tolerance.

Testosterone treatment in adolescent boys with constitutional delay of growth and development.

Administration of androgens to adolescent boys with constitutional delay in growth has been highly controversial. One hundred forty-eight adolescent boys with constitutional delay of growth and puberty with a mean age of 14.3 +/- 0.7 years were treated with testosterone enanthate 100 mg intramuscularly each month for 6 months. Growth parameters, sexual maturation, and circulating concentrations of testosterone and insulin-like growth factor-I (IGF-I) were compared with those for 50 age-matched adolescent boys with constitutional delay of growth and puberty with a mean age of 14.1 +/- 0.9 years who did not receive any treatment. The mean height growth velocity, height standard deviation score, weight gain, and IGF-I concentration were significantly greater in the treatment group after 1 year of follow-up evaluation. The advancement in bone age equaled that in chronologic age in the treatment group, with no significant change in the bone age to chronologic age ratio (BA/CA) before versus after therapy. All subjects in the treatment group had clearly entered puberty by the end of 1 year. Testicular size increased significantly in the treatment group and they had significantly higher serum testosterone concentrations 6 months after the end of testosterone therapy as compared with the control group, denoting activation of the hypothalamic-pituitary testicular axis. All subjects in the treatment group were psychologically satisfied with the enhanced growth and increased muscle mass, versus only 40% of those in the control group. In conclusion, our regimen appears to be efficacious and safe for treatment of boys with constitutional delay of growth and puberty and has no deleterious effect on skeletal age.