Gd-DTPA-cascade-polymer: Potential blood pool contrast agent for MR imaging

Gadolinium-DTPA (diethylenetriaminepentaacetic acid)-cascade-polymer, a potential new blood pool contrast agent for magnetic resonance (MR) imaging, was compared with a known blood pool agent, Gd-DTPA-polylysine, in an animal model. The relative signal intensities of liver, renal cortex, pancreas, and trunk muscle were assessed in 12 pigs between 4 seconds and 120 minutes after injection of a 20 μmol/kg dose of each contrast agent, by using a FLASH (fast low-angle shot) sequence. Except for muscle, all tissues showed visible enhancement after injection of either contrast agent. After injection of Gd-DTPA-polymer, enhancement patterns in the liver, renal cortex, and pancreas were similar to those seen after injection of Gd-DTPA-polylysine. No statistically significant differences in enhancement between the two contrast agents were found at any time point. The authors conclude that the contrast kinetics of Gd-DTPA-cascade-polymer are similar to those of Gd-DTPA-polylysine and that this agent may also be used as a blood pool contrast agent for MR imaging.     

Sclerosed liver hemangioma mimicking malignant tumor at MR imaging: Pathologic correlation

This case report illustrates atypical magnetic resonance (MR) imaging findings in a liver hemangioma mimicking a malignant lesion—lower signal intensity than cerebrospinal fluid on T2-weighted spin-echo images and lack of early enhancement on dynamic contrast material—enhanced gradient-echo images. Pathologic analysis demonstrated nearly total replacement of the vascular cavities by dense fibrous tissue. In this rare, sclerosed form, this lesion could not be defined as a hemangioma with MR imaging.     

Intramuscular dexmedetomidine premedication—an alternative to midazolam-fentanyl-combination in elective hysterectomy?

Sedation, anxiolysis, intubation responses and fentanyl anaesthetic requirements were investigated in a double-blind, randomized study in twenty ASA I-II elective hysterectomy patients. Ten patients received dexmedetomidine 2.5 μg kg^-1 i.m. 60 min before induction and saline placebo i.v. 2 min prior to induction (= DP group). Ten patients received midazolam 0.08 mg kg^-1 i.m. 60 min and fentanyl 1.5 μg kg^-1 i.v. (= MF group) 2 min before induction of anaesthesia with thiopentone 4 mg kg^-1. Anaesthesia was maintained with 70% nitrous oxide in oxygen and with fentanyl 2 μg kg^-1 i.v. increments according to predetermined criteria. Both premedications induced sedation ( P < 0.01 in both groups) and anxiolysis ( P < 0.01 in DP vs <0.05 in MF group) without any differences between the groups. Haemodynamic changes following tracheal intubation did not significantly differ between the groups. Intraoperatively systolic and diastolic arterial pressure were 15% and 13% lower in DP group ( P < 0.01 and P < 0.05 for drug effect), the mean heart rate was approximately 9 beats min^-1 lower in DP group (n.s.). Fentanyl was required more often in MF group: median 3.5 (QD 1.5) vs. 2.5 (QD 0.5) times in DP group ( P < 0.05), the total amount being 57% smaller in DP group: 0.03 (QD 0.01) vs. 0.07 (QD 0.02) μg kg^-1 min^-1 ( P < 0.05). Postoperative course and analgesic requirements were similar in both groups. Dexmedetomidine premedication may offer an alternative to current anaesthesia practice in elective hysterectomy.     

模糊数学方法用于职业危害因素的综合评价

模糊数学方法用于职业危害因素的综合评价徐新云（湖南省劳动卫生职业病研究所，长沙４１０００７）用模糊数学方法进行综合评价时，首先要确定评判等级，各评判因素在不同等级中的取值，以及各评判因素的权重系数三方面内容。本文将评判等级定为优、良、一般、差、很差５...     

Health status measurement in Parkinson's disease: validity of the PDQ-39 and Nottingham Health Profile.

We assessed the feasibility and psychometric properties of two commonly used health status questionnaires in Parkinson's disease (PD): the generic Nottingham Health Profile (NHP) and the disease-specific 39-item Parkinson's disease Questionnaire (PDQ-39), from a cross-sectional postal survey of PD patients (N = 81), using traditional and Rasch measurement methodologies. Overall response rate was 88%. Both questionnaires were found feasible, although the NHP performed less well. The PDQ-39 had fewer floor effects and was better able to separate respondents into distinct groups than the NHP, whereas the latter exhibited less ambiguous dimensionality and better targeting of respondents with non-extreme scores. Reliability and validity indices were similar, and potential differential item functioning by age and gender groups was found for both questionnaires. PDQ-39 response alternatives indicated ambiguity. With few exceptions, questionnaire scales were unable to meet recommended standards fully. While preliminary, this study illustrates the need for thorough evaluation of outcome measures and has implications beyond the questionnaires used here. Although promising, both questionnaires warrant further developmental work and stronger support of measurement validity before they could be considered fully suitable for valid use in PD, in particular in earlier stages of the disease.     

Effects of propofol emulsion and thiopentone on T helper cell type-1/type-2 balance in vitro

We have earlier found increased percentages of T helper cells (CD4-positive lymphocytes) in the blood circulation after propofol infusion anaesthesia. Cytokines interferon-γ (IFNγ) and interleukin-4 (IL-4) are important in the differentiation of T helper cells into subtypes T helper type-1 (Th1) and type-2 (Th2). To study the effects of propofol emulsion, its solvent Intralipid^® and thiopentone on Th1/Th2 balance, measurements of IFNγ and IL-4 production by mononuclear leucocytes were carried out in vitro . As IL-2 has a central role in immune responses to surgery, its production was also measured. Concanavalin A-stimulated mononuclear cells were cultured in the presence of propofol emulsion at 3.5 or 10 μg.ml⁻¹, Intralipid^® 35 or 100 μg.ml⁻¹, or thiopentone 3 μg.ml⁻¹. Cytokine production was measured from the conditioned media of mononuclear cell cultures. Decreased IFNγ (p <0.001) and IL-4 concentrations (p < 0.01) were found in the presence of thiopentone, but IL-2 production was unaffected. By contrast, propofol emulsion or Intralipid^® had no effects on IFNγ, IL-2 or IL-4 concentrations. Propofol 10 μ.ml⁻¹ increased the IFNγ/IL-4 ratio from the control value median 243 (162–562) (25th–75th percentile) to 363 (195–1028) (p < 0.01), but thiopentone decreased it to 145 (60–214) (p < 0.01). These findings show that propofol and thiopentone have different effects in vitro on Th1/Th2 balance and suggest that they have different modulating effects on the immune response.     

Initial experience with dynamic MR imaging in evaluation of normal bone marrow versus malignant bone marrow infiltrations in humans

The purpose of this study was (a) evaluation of dynamic contrast-enhanced MR imaging of normal bone marrow versus malignant bone marrow infiltrations in patients with proven B-cell-type chronic lymphocytic leukemia (B-CLL) and (b) correlation with the clinical stage according to Binet (stages A, B, C) and response to therapy. Bone marrow imaging of the lumbar spine, pelvis, and proximal femurs was performed at 1.5 T in 45 patients without known malignancy and in 30 patients with B-CLL. The differences between opposed-phase and in-phase dynamic gradient-echo sequences before and up to 10 minutes after intravenous application of .1 mmol/kg body weight of gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) were evaluated in normal bone marrow. The contrast-enhancement patterns of normal and malignant bone marrow were compared using the opposed-phase dynamic gradient-echo sequence. Ten of the patients with bone marrow infiltrations (Binet stage C) additionally underwent MR imaging follow-up during therapy. Opposed-phase gradient echo sequences demonstrated a signal decrease of normal bone marrow, and in-phase gradient echo sequences demonstrated a signal increase of normal bone marrow after administration of Gd-DTPA. The dynamic signal intensity time courses differed significantly (P < .05) between Binet stages B and C and controls as well as among the three Binet stages of B-CLL. In the 10 patients followed during therapy, MR imaging sensitively demonstrated response (n = 6), nonresponse (n = 2), or relapse after initial response (n = 2). In out-of-phase imaging, both normal bone marrow and initial bone marrow infiltration in CLL stage Binet A show signal decrease after administration of contrast agent, whereas there is increase in signal intensity in higher-grade bone marrow infiltration in Binet stage B or C disease. The signal loss of normal bone marrow in out-of-phase imaging is a phase effect rather than a T2* effect. The differentiation of initial from higher-grade bone marrow infiltration on out-of-phase images relies solely on a shift in the fat/water ratio.     

The effect of subhypnotic doses of propofol on the incidence of pruritus after intrathecal morphine for Caesarean section

The effect of subhypnotic doses of propofol on intrathecal morphine-induced pruritus was studied in a prospective, randomly allocated, double-blind controlled trial. Fifty-eight women undergoing elective lower segment Caesarean section for a singleton fetus received spinal anaesthesia with 2.5 ml hyperbaric 0.5% bupivacaine and 0.2 mg of preservative-free morphine. They then received propofol 1 ml (10 mg) or Intralipid 1 ml (control group) intravenously after delivery. Pruritus was assessed using a five-point verbal rating scale at hourly intervals for 8 h. A second dose of their allocated treatment drug was administered at the first recording of significant pruritus. The pruritus score was reassessed after 5 min and the treatment was repeated if pruritus remained. There were no differences between the groups in the onset of pruritus or its successful treatment. No adverse side-effects were associated with this dose of propofol. There were no differences in the incidence of post-operative nausea and vomiting between the two groups. Subhypnotic propofol is not an effective treatment for intrathecal morphine-induced pruritus in women following Caesarean section.     

The safety of patient-controlled sedation

We have investigated the safety of a previously described method of patient-controlled sedation in 100 healthy patients presenting for elective surgery. The device used 0.33-ml boluses of propofol (10 mg.ml⁻¹) infused over 6 s with no lockout. All patients attempted to put themselves to sleep by pressing a button on the hand-held device. The oxygen saturation, heart rate, sedation score and airway patency were noted every minute. When the patient stopped pressing the button, the anaesthetist took over the handset and continued pressing the button until the patient became unresponsive. The system allowed rapid sedation. Only five patients were still anxious after 2 min. After 3 min, no patient was still anxious and more than 70 patients had slurred speech. When they stopped pressing the button, 11 patients were judged oversedated, of whom two were unresponsive. One patient's oxygen saturation decreased transiently to 84%: no other patient's oxygen saturation decreased below 90%. There were no other significant changes. We conclude that the system studied works well but carries too high a risk of oversedation for unsupervised use.