Diagnostic Criteria for a Curable Form of Chronic Rhinosinusitis: The Mucous Recirculation Syndrome

In clinical practice, nonallergic rhinosinusitis (rhinopathy) is a common diagnosis of exclusion. The mucous recirculation syndrome is one incompletely defined condition that masquerades as nonallergic rhinopathy. Mucous recirculation syndrome, a curable condition, should be differentiated from nonallergic rhinopathy. The underdiagnosis of this condition is due in part to a lack of diagnostic criteria. In this article, we review the medical literature to better characterize mucous recirculation syndrome and to establish diagnostic criteria for it.     

Nω-nitro-L-arginine attenuates early ischemic neuronal damage of prolonged focal cerebral ischemia and recirculation in rats

Abstract

The present study aimed to .examine the effects of NCJ)-nitro-L-arginine (LNA) on the early ischemic neuronal damage (EIND). All the experiments were carried out under general anesthesia, maintaining the blood gases and the body temperature within the physiologica.l ranges. The local CBF, the topographically corresponding cortical specific gravity, and the volume of fiNO were determined in each rat, which was subjected to prolonged or temporary occlusion of middle cerebral artery (MCA) using our original miniclip. Significant cortical edema developed only in the brain area where the loca.f CBF valUe was below 200 ml 100 g-l min^-1 The prolonged MCA occlusion for 1, 2, and 4 h induced a time-dependent increase in the severity of cortical edema and the volume of fiNO. Removal of the clip invariably induced recirculation. Compared to that induced by 4 h prolonged ischemia, the brain damage was improved by 1 h MeA occlusion followed by 3 h recirculation, whereas it was significantly worsened by 2 h ischemia followed by 2 h recirculation. While LNA [1 mgt i.p., given two times during the experiment] only partially1nhibited -the activity of brain nitric oxide synthase, it remarkably ameliorated fiNO of both prolonged ischemia and recirculation in this model. The above findings indicate the pathogenic role of nitric oxide in prolonged ischemia as well as recirculation. [Neural Res 1997; 19: 192–203]

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血液透析通路再循环影响因素分析及对策

为了解血液透析再循环的影响因素，对５０例次血液透析病人进行血肌酐和血尿素氮再循环率（Ｒ）测定。结果：股静脉插管组与内瘘穿刺组无差异（Ｐ＞０．０５）。而内瘘穿刺组中，在动静脉压力相近时，Ｒ与动静脉穿刺针距无关（Ｐ＞０．０５）；动脉压≥－１３．３ｋＰａ和＜－１３．３ｋＰａ组比较，Ｒ有显著性差异（Ｐ＜０．００１），直线回归检验呈密切正相关（ｒ＝０．７３２８）；静脉压≥１３．３ｋＰａ和＜１３．３ｋＰａ组Ｒ值亦有差异（Ｐ＜０．０５），直线回归检验呈密切正相关（ｒ＝０．７２８１）。可见，股静脉插管和内瘘方式及穿刺针距不是影响Ｒ的主要因素，但在透析过程中，要避免使静脉压力升高或动脉负压值增大的因素     

A boussinesq model of natural convection in the human eye and the formation of Krukenberg's spindle

The cornea of the human eye is cooled by the surrounding air and by evaporation of the tear film. The temperature difference between the cornea and the iris (at core body temperature) causes circulation of the aqueous humor in the anterior chamber of the eye. Others have suggested that the circulation pattern governs the shape of the Krukenberg spindle, a distinctive vertical band of pigment on the posterior cornea surface in some pathologies. We modeled aqueous humor flow the human eye, treating the humor as a Boussinesq fluid and setting the corneal temperature based on infrared surface temperature measurements. The model predicts convection currents in the anterior chamber with velocities comparable to those resulting from forced flow through the gap between the iris and lens. When paths of pigment particles are calculated based on the predicted flow field, the particles circulate throughout the anterior chamber but tend to be near the vertical centerline of the eye for a greatest period of time. Further, the particles are usually in close proximity to the cornea only when they are near the vertical centerline. We conclude that the convective flow pattern of aqueous humor is consistent with a vertical pigment spindle. © 2002 Biomedical Engineering Society. PAC2002: 4266Ew, 8710+e, 8719Pp     

Blood Cardioplegia Infusion Using a Recirculation Type Circuit Generates Bradykinin in Significant Amounts During Open Heart Surgery

Abstract: The single pass type (SP) of blood cardioplegia is commonly used in North America during open heart surgery. However the recirculation type (RC) of blood cardioplegia is still widely used in other areas including Japan. Infusion blood cardioplegia using the latter technique often decreases the perfusion pressure. To determine the cause for this, blood levels of bradykinin (BK) were measured in cardiopulmonary bypass (CPB) and the 2 types of blood cardioplegic circuits. As the BK levels in the RC cardioplegia (>3,000 pg/ml) rose, the perfusion pressure decreased abruptly with the increase of the BK levels in the CPB circuit. With SP cardioplegia, the BK level was not increased either during cardioplegia (p < 0.009) or CPB (p < 0.009), and the perfusion pressure was not decreased (p < 0.02). We concluded that the SP circuit is superior to the RC one because of the lesser production of BK and thus lesser fluctuation of perfusion pressure.     

深静脉留置导管与动静脉内瘘的重复循环率对比研究及其对透析充分性的影响

目的：比较深静脉留置导管与动静脉内瘘在重复循环率及透析充分性上的差异。方法：维持性血液透析患者及插管透析的新患者各30例，检测透析前后、下次透前血尿素氮，记录透析前后体重、脱水量、透析时间，计算重复循环率、整体尿素清除率、蛋白分率率、平均时间尿素氮浓度。结果：深静脉留置导管与动静脉内瘘在重复循环率及透析充分性上无显著差异。结论：深静脉留置导管可达到透析充分，是理想的血液通路。     

PRE‐DIALYSIS APPLICATION OF THE GLUCOSE INFUSION TEST FOR RECIRCULATION DETECTION

Vascular access recirculation (R) is a well‐known cause of decreased dialysis dose. In this paper a new easy protocol for R detection in pre‐dialysis derived from the classic Glucose Infusion Test (GIT) is introduced. The pre‐dialysis GIT (GIT‐pre) is based on the glucose (5%, 10 ml) bolus injection directly into the venous needle and on a simultaneous withdrawal from the arterial needle. If the glucose value increases during the glucose bolus, R is present. This new protocol was validated on 29 chronic haemodialysis patients (20 AVFs, 7 CVCs, 2 PTFE grafts), comparing the glucose increase with the classic GIT during dialysis. Only one CVC had R with the blood lines in the normal position (Δglu = 465 mg/dl with GIT‐pre and a Δglu = 186 mg/dl, R = 9.3% with classic GIT) while in the reverse blood line position, all CVCs showed a significant glucose increase (mean GIT‐pre Δglu = 195 mg/dl; mean GIT Δglu = 140 mg/dl corresponding to a R = 8%). There were 5 AVFs with true R (correct blood lines position) clearly identified by both methods (mean values Δglu = 316 mg/dl with GIT‐pre and a Δglu = 390 mg/dl, R = 19.5% with classic GIT). Preliminary results show good reliability of the new protocol in identifying VA R caused either by failing VA with stenosis or by reverse blood lines position. The GIT‐pre is a simpler application of the classic GIT useful for testing new VA, new needle positions or CVC performance before starting dialysis. A simpler R test could increase the frequency of the measurements and consequently the power of R in early detection of VA problems.     

Hemodialysis catheter placement and recirculation in treatment of hyperammonemia

A 2-year-old girl with carbamoyl phosphate synthetase deficiency underwent emergency hemodialysis (HD) for treatment of acute life-threatening hyperammonemia. HD was performed via catheters placed in each femoral vein serving as vascular access. The tip of one of the catheters (aspirating line) was in the left external iliac vein and the tip of the other catheter (the return line) was in the inferior vena cava (IVC). High blood flow rates were used in order to rapidly lower the blood ammonia (NH₃) levels. However, unanticipated marked recirculation in the IVC, between the dialysis aspirating and return catheters, was encountered, preventing significant reduction in blood NH₃. The recognition of this problem, suggested solutions, and prevention are described. Received August 27, 1997; received in revised form and accepted February 4, 1998     

Enzyme histochemical and ultrastructural alterations in the brains of Friesian calves with GM1 gangliosidosis

Summary A no-reflow phenomenon was observed in cats immediately after cerebral ischemia. When ischemia was followed by a normal recirculation of 1 hr duration, only minor perfusion defects and no intracranial hypertension was observed. If, however, ischemia was preceded by moderate hypoxia for several hours, extreme postischemic hyperemia was necessary to prevent the development of intracranial hypertension and a no-reflow phenomenon. Electron microscopic investigation revealed that capillary obstruction did not develop within the first hour after ischemia. Thus the no-reflow is not related to capillary lesions. The results support the view that the no-reflow phenomenon is produced by blood aggregates which obstruct vessels. This phenomenon is to some extent reversible. If, however, a slow-down of blood flow is induced by intracranial hypertension based on postischemic brain edema, the no-reflow is enhanced. There was no indication that arterial hypertension increases brain edema after ischemia.     

The migratory behavior of murine CD4+ cells of memory phenotype

Lymphocyte differentiation is connected with profound alterations in the migratory pattern of lymphocytes. Whereas naive cells predominantly recirculate through lymphoid tissues, activated lymphocytes acquire an increased preference for immigration into non-lymphoid tissues and a reduced capacity for recirculation via high endothelial venules (HEV). A variety of data had indicated that memory-related subpopulations of cells in man and sheep, classified by the low expression of the CD45RA isotype, also lack the capacity to recirculate via HEV. However, recent data in the rat called these results into question. We therefore analyzed the migration properties of murine CD4⁺ T cell subpopulations defined by several markers used to distinguish memory from naive CD4⁺ cells in mice, namely CD45RB, L-selectin and CD44. Our data clearly show that the majority of putative memory cells expressing either low levels of CD45RB, low levels of L-selectin or high levels of CD44 display a strongly reduced capacity for direct entry into lymphoid tissues, including the spleen, from the blood stream. The accumulation in peripheral lymph nodes is further reduced by treatment with anti-L-selectin antibody, which blocks their entry via HEV. This indicates that memory CD4⁺ T cells are not excluded from crossing lymph node HEV, and that the numbers of cells entering the node via this route exceed the numbers entering via the afferent lymph, at least in the absence of local inflammation. Concomitantly, a strongly enhanced localization of cells of the memory phenotype is observed in lung and liver as compared with naive cells. Trafficking to specific sites such as skin or gut mucosa is not a prominent feature of the total population of memory cells. The trafficking to lung and liver and an increased ability to bind to dendritic cells, demonstrable in in vitro adhesion assays, suggest a more sessile phenotype of most memory cells. With respect to these properties, memory cells have a surprizing similarity to fully activated lymphocytes.