99Tcm-DMSA肾皮质显像诊断小儿肾发育不良

目的 探讨^99Tc^m—二巯基丁二酸(DMSA)肾皮质显像诊断小儿肾发育不良的价值。方法 疑为肾发育不良患儿29例，行常规^99Tc^m—DMSA肾皮质显像和腹部B超检查。图像分析：将发育不良肾分为0～4级。结果 ^99Tc^m—DMSA肾皮质显像示29例患儿中24例为单侧肾发育不良，其中11例1级，7例2级，6例3级，余5例患肾未显影为0级，结合其他：检查诊断为肾发育不良。患肾分肾功能为0～24．9％(平均6．3％)。29例患儿中24例患肾肾皮质显像诊断为肾发育不良，5例患肾未显影，由其他影像学方法确诊，诊断灵敏度为82．76％。29例中19例经手术治疗，病理检查证实为肾发育不良。结论 ^99Tc^m—DMSA肾皮质显像诊断肾发育不良灵敏度高、可靠，可确定发育不良肾部位和判断肾功能。     

The subdivisions of the intermediolateral nucleus in the sacral spinal cord of the cat

The subdivisions of the sacral intermediolateral nucleus (IML) of the cat have been studied by using a double-labeling technique of retrograde Fluoro-gold (FG) and wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) tracing. The parasympathetic preganglionic neurons (PGNs) that were labeled by the FG injected into the pelvic nerve formed a ‘V’-shaped column known as the sacral parasympathetic nucleus (SPN) in the sacral IML. The neurons that were labeled by the WGA-HRP applied to the lateral parabrachial nucleus (PBL) formed an elongated spindle-shaped column extending throughout the IML of the sacral segments. We designated it by the name of sacral visceral sensory nucleus (SVSN). These findings indicate that the sacral IML of the cat contain two distinct subdivisions, SPN and SVSN.     

Hereditary Hypertriglyceridemic Rat: A New Animal Model of Metabolic Alterations in Hypertension

Hereditary hypertriglyceridemic rats (hHTg) were developed as a new genetic model for the study of relationships between blood pressure (BP) and metabolic abnormalities. This strain has been produced by selective inbreeding from Wistar rats according to the rise of plasma triglycerides induced by a high-sucrose diet. Though hHTg rats display hypertriglyceridemia, impaired glucose tolerrance, hyperinsulinemia, insulin resistance and increased BP even without nutritional stimuli, high sucrose feeding further aggravates these symptoms. High plasma triglycerides levels in hHTg rats seem to be a consequence of their hyperproduction. Impaired insulin action is responsible for the defective glucoregulation in this strain. The loss of insulin responsiveness might be due to a reduction in the number of glucose transporters. Highly significant relationships among plasma triglycerides, ouabain-resistant Na⁺ transport and BP were demonstrated in the hHTg rats. Segregating populations (F2 hybrids) should be used for genetic analysis of the primary role of lipid and/or ion transport abnormalities in the pathogenesis of this form of genetic hypertension.     

Computer-Assisted Design of an Implantable, Intrathoracic Artificial Lung

Abstract: A semiempirical mathematical model of convective oxygen transport is used to design a new, low pressure loss, implantable artificial lung that could be used as a bridge to lung transplantation in patients with advanced respiratory failure. The mass transfer and flow friction relations pertinent to the design of a cross–flow hollow fiber membrane lung are described. The artificial lung is designed to transfer over 200 ml/min of oxygen at blood flow rates up to 5 L/min. A compact design and a blood-side pressure loss of <15 mm Hg allows the device to be implanted in the left chest without the need for a prosthetic blood pump. Surgical implantation of the artificial lung would require the creation of inflow and outflow anastomoses. Oxygen would be supplied via an external source. Blood properties, operating conditions, and empirically determined mass transfer and flow properties are all specified and input into a computer program that numerically solves the design equations. Computer–generated values for the device frontal area, blood path length, and fiber surface area are thereby obtained. The use of this computer–assisted design minimizes the need for extensive trial–and–error testing of prototype devices. Results from in vitro tests of a prototype implantable lung indicate that the mathematical model we describe is an accurate and useful tool in the design of hollow fiber artificial lungs.     

Impact of Ultrafiltration on Back-Diffusion in Hemodialyzer

Abstract: Ultrafiltration of water from blood to dialysate decreases the rate of back–diffusion of solutes from dialysate to blood. Therefore, back–clearance ( bK ) of hemodialyzers may be expressed as bK = bK _o – bTrQ _u, where bK _o is the diffusive back–clearance, bTr is the "back–"transmittance coefficient, and Qu is the net ultrafiltration rate. A formula for bK was derived from the one–dimensional theory of hemodialyzer, and bTr was described as a function of bK _o and the Staverman reflection coefficient. The transport parameters, bK _o and bTr , for creatinine and vitamin B₁₂ were measured in two types of hemodialyzers with negligible back–filtration, using water solutions, and compared with the transport parameters, K _o and Tr , for the case of both diffusion and ultrafiltration from blood to dialysate. bK _o was in general equal to K_o. bTr was not different from Tr for creatinine whereas bTr was lower than Tr for vitamin B₁₂. Experimental values of bTr for vitamin B₁₂ were in general agreement with theoretical predictions. However, experimental values of bTr for creatinine were lower than predicted values. We conclude that the impact of ultrafiltration on back–clearance for slowly diffusing solutes is weaker than on their clearance.     

Taurine entry into perilymph of the guinea pig

Taurine is a β-aminosulfonic acid and is a ubiquitous amino acid whose role in the cochlea is not well established. In this study, its entry from blood into perilymph was investigated in the guinea pig as animal model. The penetration rate of [³H]taurine (molecular weight 125) into the perilymph of the scala vestibuli was measured 1 and 2 h after the intravenous infusion of [³H]taurine in nephrectomized animals. Results showed a rate of penetration in perilymph related to plasma at 36 ± 4.7% (n = 5) after 1 h and 43 ± 5.6% (n = 5) after 2 h. Compared to the penetration rate of urea (molecular weight 60) and mannitol (molecular weight 186) reported previously in rats, a passive entry of taurine into perilymph through the blood-perilymph barrier is suggested. Received: 30 July 1997 / Accepted: 15 January 1998     

Chronic administration of theophylline to rats induces a post-insulin binding defect in adipocyte glucose transport

Summary To determine whether adenosine is involved in long-term regulation of glucose transport in adipose tissue, we have investigated effects of administration of an adenosine receptor antagonist (theophylline) on adipocyte glucose transport. Rats were injected with theophylline (30 mg/kg, dissolved in 0.9% NaCl) daily for 7 days. Controls were injected with saline. The rats were then killed, and epididymal adipocytes were isolated. Insulin-stimulated glucose transport rates were decreased by about 25%–30% in the cells from theophylline-treated rats at all insulin concentrations tested. The half-maximally effective concentration of insulin was not altered (6.5±0.5 and 6.7±0.5 mU/l in control and treated cells respectively), suggesting a post-insulin binding defect. This was confirmed by the finding that ¹²⁵I-insulin binding to the cells was not altered. Adenosine receptor number and affinity (measured on detergent-solubilized adipocyte extracts using ¹²⁵I-hydroxyphenylisopropyl adenosine) was also not changed by theophylline treatment. We conclude that theophylline administration causes decreased glucose transport rates in rat adipocytes at a post-insulin binding level. Thus, chronic adenosine receptor blockade impairs adipocyte glucose transport, suggesting that adenosine is involved in long-term regulation of glucose metabolism in adipose tissue.     

Cerebellar nuclear afferents--where do they originate? A re-evaluation of the projections from some lower brain stem nuclei

Summary Cerebellar nuclear afferents from some caudal brain stem nuclei in the cat were studied by means of retrograde transport after implantation of the wheat germ agglutinin-horseradish peroxidase complex in crystalline form in the cerebellar nuclei. The findings give evidence that projections to the cerebellar nuclei from certain nuclei of the reticular formation proper (e.g., from the gigantocellular reticular nucleus) are very modest, while there appears to be no or extremely few cerebellar nuclear afferents from the paramedian reticular, spinal trigeminal, gracile, cuneate and external cuneate nuclei. Previous tracer studies have given evidence that also the pontine and red nuclei send very few, if any, fibres to the cerebellar nuclei. All these brain stem regions are known to project to the cerebellar cortex. This relative lack of mossy fibre collaterals to the cerebellar nuclei is discussed with references to previous literature on the distribution of cerebellar nuclear afferents, and the problem of how the cerebellar nuclei are facilitated is considered.Abbreviations Br.c. superior cerebellar peduncle (brachium conjunctivum) - Br.p. middle cerebellar peduncle (brachium pontis) - C.r. interior cerebellar peduncle (restiform body) - HRP horseradish peroxidase - L left - N.c. cuneate nucleus - N.c.e. external cuneate nucleus - N.c.t. nucleus of corpus trapezoideum - NIA anterior interposed nucleus - NIP posterior interposed nucleus - NL lateral (dentate) nucleus - N.l.l. nuclei of lateral lemniscus - NM medial (fastigial) nucleus - N.m.X. dorsal motor vagal nucleus - N.mes. mesencephalic trigeminal nucleus - N.r.l. lateral reticular nucleus (nucleus of the lateral funiculus) - N.r.p. paramedian reticular nucleus - N.r.t. reticular tegmental pontine nucleus - N V, VI, VII, XII root fibres of cranial nerves - Ol.s. superior olive - P.h. nucleus praepositus hypoglossi - Py pyramid - R right - R.gc. gigantocellular reticular nucleus - R.l. lateral reticular nucleus of Meessen and Olszewski - R.p.c. caudal pontine reticular nucleus - R.pc. parvicellular reticular nucleus - R.v. ventral reticular nucleus - Tr.sp.V. spinal tract of the trigeminal nerve - T.s. solitary tract surrounded by nucleus of solitary tract - V.m. medial vestibular nucleus - WGA wheat germ agglutinin - WGA-HRP wheat germ agglutinin-horseradish peroxidase conjugate - V, VI, VII, X, XII motor nuclei of cranial nerves     

Noradrenergic projections to brainstem nuclei: evidence for differential projections from noradrenergic subgroups

Retrograde transport of the fluorescent tracer True Blue was used in combination with immunohistochemical staining of dopamine-beta-hydroxylase (a marker protein for noradrenergic neurons) to determine the origin of noradrenergic projections to three cranial nerve nuclei: 1) the motor nucleus of the trigeminal nerve, 2) the motor nucleus of the facial nerve, and 3) the spinal trigeminal nucleus pars interpolaris. Noradrenergic cells in the rat brainstem were divided into subgroups and their numbers were determined in serial sections stained with an antiserum to rat dopamine-beta-hydroxylase. Following tracer injections into the three brainstem nuclei, retrogradely labeled noradrenergic neurons were counted and the percentage of True Blue-labeled noradrenergic cells in each subgroup was calculated. Injections of tracer into the three cranial nerve nuclei resulted in distinctly different labeling patterns of noradrenergic cells. Of the total number of norepinephrine neurons projecting to the motor nucleus of the trigeminal nerve, 68% were observed within the A7 cell group; 75% of those innervating the motor nucleus of the facial nerve were found in the A5 cell group, and 65% of those projecting to the spinal trigeminal nucleus pars interpolaris were present in the locus ceruleus and subceruleus. These findings indicate that norepinephrine cells in the rat brainstem do not constitute a homogeneous population of cells but that several discrete systems can be identified that differ not only in topography but also in the terminal distribution of their axons. This combined retrograde transport-immunohistochemical study reveals a much higher degree of topographic order in the projections of norepinephrine neurons than has previously been recognized. The observation of differential projections of noradrenergic subgroups argues against the notion of a global influence of these cells over functionally diverse areas of the brainstem.     

Axonal transport and tissue contents of substance P in rats with long-term streptozotocin-diabetes. Effects of the aldose reductase inhibitor ‘statil’

This study examined the axonal transport of substance P-like immunoreactivity (SPLI) and its content in dorsal root ganglion, trigeminal ganglion, stomach and ileum of non-diabetic rats and two groups of rats with streptozotocin-induced diabetes of 9 months duration. One diabetic group received the aldose reductase inhibitor ‘Statil’ throughout the period of study. To reduce morbidity all diabetic animals were given twice-weekly injections of a long-acting insulin which restricted weight loss but did not prevent regular and severe hyperglycaemia. Axonal transport of SPLI was studied by measurement of accumulation at 12 h ligatures on the left sciatic nerve. There were no differences between the 3 groups either in the calculated anterograde and retrograde mean rates of accumulation (ranges 6.0 to 7.6 and 0.38 to 0.72 mm/h respectively) or mobile fractions of SPLI (means from 0.54 to 0.58). There were, however, marked reductions in anterograde and retrograde accumulations of SPLI in the constricted nerves of the ‘untreated’ diabetics (respectively 57 and 33% of controls;P < 0.01 for both). In the ‘Statil’-treated rats these deficits were attenuated (80 and 75% of controls). Diabetes also reduced the SPLI content of unligated sciatic nerve and trigeminal ganglion (65 and 75% of controls). ‘Statil’ prevented the deficit in the ganglion, but not in the nerve. ‘Statil’ treatment prevented themyo-inositol depletion and attenuated the sorbitol and fructose accumulation seen in the sciatic nerves of the untreated diabetic animals suggesting effective inhibition of aldose reductase in this tissue. The total SPLI content of the stomach and 1-cm segments of ileum were unaltered in the diabetic animals but due to the increased weights of these tissues the SPLI content per unit weight was reduced. These changes were unaffected by ‘Statil’.