白细胞介素—2新的功能位点及其中枢镇痛作用

白细胞介素－２（ＩＬ－２）不仅是重要的免疫调节因子，而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标，发现侧脑室注射ＩＬ—２能显著提高动物痛阈，并能被纳洛酮所阻断，表示ＩＬ－２的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性ＩＬ－２实查体仍具有中枢镇痛作用，表明ＩＬ—２分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断ＩＬ—２的中枢镇痛作用，而不能影响ＩＬ—２增殖ＣＴＬＬ－２细胞的作用，提示ＩＬ－２发挥镇痛和免疫调节作用可能通过不同的受体途径。ＩＬ－２分子中第４５位Ｔｙｒ残基突变为Ｖａｌ后，虽仍保留了免疫活性，但丧失了镇痛功能，表示４５位Ｔｙｒ残基是ＩＬ—２发挥中枢镇痛功能的关键残基之一。我们推测ＩＬ—２的镇痛功能位点可能在ＩＬ—２分子中第４５位Ｔｙｒ残基附近区域。     

Percutaneous transhepatic stenting by wallstents of portal vein and bile duct stenoses caused by immunoblastic sarcoma in a liver transplantation

Posttransplant lymphoproliferative disorders are infrequent tumors related to chronic immunosuppressive therapy. We present a liver transplant recipient who developed such a tumor in the porta hepatis that provoked obstruction of the entire portal triad. Treatment consisted of systemic chemotherapy, percutaneous dilatation, and placement of Wallstent endoprostheses across both biliary and portal vein stenoses. The patient died 3 weeks later of pneumonia and sepsis. At necropsy, the tumor was completely necrosed and the prostheses in both the common bile duct and the portal vein were patent.     

The growth and development of vegan children

The results of prospective study on the growth and diets, estimated from 7-day weighed food intake records, of 20 life vegan children (aged 5.8–12.8 years) are presented. The growth and development of the children were normal but they tended to be lighter in weight and exceptionally lean compared with standards. Heights were around the median of the Tanner-Whitehouse standards but were lower than the medians recently proposed by the Department of Health. Energy intakes were similar to those reported in children of the same age in the general population, but dietary fibre intakes were very high which may have influenced the digestible energy. Sugar provided an average 15.6% of the dietary energy and this was supplied mainly by fruit and fruit juice. Mean fat intakes were close to the dietary reference values. Daily intakes of essential nutrients generally met the amounts recommended, with the exceptions of calcium and vitamin B₁₂. Many children received supplementary sources of vitamin B₁₂ and only two children had intakes below the lower recommended nutrient intake. Intakes of saturated fatty acids were low and those of linoleic acid were high. The ratio of linoleic/α-linolenic acid was high. As docosahexaenoic acid is absent from vegan diets, it is suggested that vegans should use oils with a lower ratio of linoleic/α-linolenic acid. Future studies should also consider the influence of a vegan diet on retinal function. None of the children was immunized against whooping cough and 11 had not been immunized against polio: 16 of the children had suffered from whooping cough. Future studies need to take into account factors other than diet when assessing the health of vegans. The results of this study show that children can be successfully reared on a vegan diet providing sufficient care is taken to avoid the known pitfalls of a bulky diet and vitamin B₁₂ deficiency.     

Renal excretion of endothelin in children

Endothelin (ET) is a peptide with profound vasoconstrictive potential. First isolated from porcine endothelial cell supernatant, it is produced also by smooth muscle, epithelial and circulating cells. Besides vasoconstriction, a wide spectrum of biological activities of ET (via activation of membrane receptors) has been described. These include regulation of other hormones and neurotransmitters, cellular growth and proliferation, bronchoconstriction, and, in the kidney, natriuresis and water diuresis. ET exerts its effects mainly in an autocrine and paracrine fashion. A high concentration of ET is found in urine, compared with plasma originating mainly from the kidney itself. In this review we focus on the role of urinary excretion of ET in children. ET excretion was determined under different physiological and pathological conditions. In premature infants and newborns, the daily excretion of ET (corrected for body surface) was higher than in older children; it was constant, and comparable to the values in healthy adults after the age of 2 years. Renal ET excretion correlated positively with urine flow in both healthy and sick children. Conditions with tubular and/or collecting duct cell damage, such as severe hypoxia, hemolytic-uremic syndrome, renal transplantation, diabetes mellitus, chronic renal failure, and contrast media cytotoxicity were characterized by elevated urinary excretion of ET. In conclusion, the renal excretion of ET is influenced by several factors, probably reflecting the intrarenal ET production. ET has a low specificity with regard to renal injury. Received May 7, 1996; received in revised form January 14, 1997; accepted January 17, 1997     

Embolization of dural arteriovenous fistulas draining into the transverse or sigmoid sinus

The results of embolisation of dural arteriovenous fistulas draining into the transverse or sigmoid sinus were evaluated in 20 patients. Tinnitus was the main symptom in all patients although one also suffered from vertigo and sudden deafness. Nine patients were treated with PVA (polyvinylalcohol) alone and 11 with combined PVA and bucrylate (isobutyl-2-cyanoacrylate) in 1–9 procedures. Recurrence of symptoms, requiring repeated procedures was common but at subsequent clinical follow up 10 patients had no tinnitus, 5 were improved and only 5 experienced no change. Complications occured in six patients: four had transient neurological symptoms and one of these also developed a necrotic wound which later healed. One patient suffered from a cranial nerve palsy and one had an intracranial haemorrhage after a transvenous embolisation. This last patient recovered completely. The best clinical results were achieved in small fistulas and fistulas treated with combined bucrylate and PVA.     

Dynamic gadolinium-enhanced echo-planar MR imaging of the liver: Effect of pulse sequence and dose on enhancement

To develop guidelines for clinical magnetic resonance imaging of the liver, the authors undertook an animal study to investigate the effect of dose and pulse sequence on liver signal intensity in gadopentetate dimeglumine—enhanced echo-planar imaging. Serial imaging of the liver was performed in anesthetized rats after intravenous administration of five different doses (0.01, 0.05, 0.1, 0.2, and 0.5 mmol/kg) of contrast agent, with six different pulse sequences. The results show that gadopentetate dimeglumine—enhanced echo-planar images obtained during the perfusion phase can yield either positive (due to increased T1 relaxation rates) or negative (due to susceptibility-induced increased T2 relaxation rates) liver enhancement depending on choice of pulse sequence and dose. At the current clinically recommended dose of 0.1 mmol/kg, maximal liver signal enhancement was seen with a T1-weighted inversion-recovery sequence, while maximal liver signal diminution was seen with a T2*-weighted gradient-echo sequence. The authors conclude that gadopentetate dimeglumine—enhanced echo-planar imaging can provide T1, T2, and T2* contrast that may be exploited for both lesion detection and lesion characterization.     

Bilateral organized chronic subdural haematomas: High field magnetic resonance images and histological considerations

Summary The authors describe a 66-year-old man with progressive gait disturbance caused by bilateral organized chronic subdural haematomas. The characteristics of these lesions on magnetic resonance (MR) images have not yet been clarified. The organized haematoma in our patient exhibited slight hypo-intensity on T 1-weighted MR images and marked hypo-intensity on T 2-weighted MR images obtained at 1.5 T. Preoperative MR imaging may give us useful information about surgical strategy in the case of chronic subdural haematoma with an unusual appearance on computed tomographic (CT) scans.     

Distribution of normal and abnormal fluid collections in the glenohumeral joint: Implications for MR arthrography

Although magnetic resonance (MR) images of the glenohumeral joint frequently demonstrate intraarticular fluid, no specific criteria have, to the authors' knowledge, been published that allow accurate assessment of the amount of fluid present. Also, despite the increasing use of MR arthrography of the shoulder, the optimal amount of intra-articular fluid that should be used with this technique has not been determined. The authors progressively distended the glenohumeral joint in six cadaveric shoulder specimens with a dilute gadopentetate dimeglumine solution and obtained MR images after injection of 2, 5, 10, 15, and 20 mL of the solution. The pattern of fluid distribution was evaluated, and these results were then used to estimate the amount of fluid that was present in the glenohumeral joint on MR images of 20 shoulders obtained in 12 asymptomatic volunteers. In 14 of these shoulders, intraarticular fluid was present; however, in none was more than 2 mL evident. Results of the cadaveric study also indicated that 15 mL of intraarticular fluid appears to be the optimal amount for MR arthrography.     

Comparison of the sphygmooscillographic method with the direct and auscultatory methods of measuring blood pressure

Objective. The objective of this study was to compare blood pressure (BP) measured by the sphygmooscillographic method with that measured by the direct and auscultatory methods.Methods. In 15 adult patients undergoing cardiac surgery, blood pressure was measured by the sphygmooscillographic and direct methods simultaneously on the same upper extremity. In another group of 86 children and 11 adults, blood pressure was measured by the sphygmooscillographic and auscultatory methods simultaneously, with one cuff. For the sphygmooscillographic measurement, we used sphygmomanometer-S, which measures blood pressure on the basis of the amplitude height (oscillometric) and the morphology (sphygmographic) of pulse waves recorded by a transducer placed in the cuff.Results. The systolic and diastolic blood pressure measured by the sphygmooscillographic method were both 2 mm Hg higher than those from the direct method; the mean blood pressure was 0.6 mm Hg higher. These differences were not significant. Compared with the auscultatory method, sphygmooscillographic systolic values were higher by 7 mm Hg, while diastolic values were lower by 9 mm Hg. These differences were significant.Conclusions. Blood pressure measurements obtained by the sphygmooscillographic method correlate well with the direct method for measuring blood pressure in children and adults; but, they do not correlate well with the auscultatory method.     

Endovascular stent implantation in patients with stenotic aortoarteriopathies: early and medium-term results.

Data regarding stent implantation for stenotic aortoarteriopathy (SAA) are incomplete. We report on nine patients with this rare syndrome who underwent arterial stent implantation. Indications, results, and complications for patients with SAA were reviewed. Nine patients underwent 11 procedures. Twenty-two stents were implanted in the aorta or brachiocephalic vessels. Five patients had diffuse stenoses, three patients had middle aortic syndrome, and one patient had thoracic and abdominal coarctation. Associated diagnoses included Williams syndrome (2), neurofibromatosis (2), Takayasu's (1), and congenital rubella (1). Median gradient was 60 mm Hg (20-140 mm Hg). Poststent gradient was 15 mm Hg (0-60 mm Hg; P < 0.001). Additional stents were implanted in two patients and five underwent stent redilation. Two patients (22%) were found to have aneurysm formation. Stent implantation effectively provides gradient relief in SAA. Gradient reduction persists or is amenable to redilation. Importantly, however, uncomplicated stent implantation does not preclude aneurysm formation and may be more common than in traditional patient groups.