High endothelial-like venules in chronically inflamed periodontal tissues exchange polymorphs

A survey of 58 gingival biopsies revealed the presence of periodontal high endothelial-like venules (PHELVs) in chronically inflamed gingival tissues. PHELVs were found to exchange polymorphonuclear cells (PMNs) almost exclusively in advanced periodontitis, with PMNs greatly exceeding the number of mononuclear cells found in PHELVs (P less than 0.001). Electron microscopy confirmed the emigration of PMNs from these vessels. The enzyme histochemical and ultrastructural features as well as the 35SO4 uptake properties of PHELVs were similar to those of the well-characterized high endothelial venules (HEVs) of rat lymph nodes. It is generally accepted that HEVs in lymphoid tissues and inflammatory sites are specially adapted to assist in the emigration of lymphocytes. However, the observation of preferential PMN emigration in the apparent absence of lymphocyte exchange from PHELVs compels further investigation of other possible functions for HEVs. In relation to this, endothelial cells are capable of producing potent cytokines and inflammatory mediators which may contribute to the development of lesions, and the possibility is discussed that high endothelial cells are functionally adapted to enhance the production of such factors.     

Characteristics of histopathological and ultrastructural features of placental villi in pregnant Nepalese women

The placenta is an important functional unit for gas transfer between mother and fetus. The placental membrane, consisting of trophoblast layer interposed between maternal and fetal blood, plays an active role for intensity of respiration, but no morphological evidence has been documented. Until now, it has been reported that fetal growth retardation and increased fetal mortality rate usually could be seen at high altitude. In an attempt to find the cause of high perinatal mortality rate in Nepal, this study was undertaken to examine pathologically about 1000 Himalayan placentas obtained in Nepal and Tibet since 1977, and the results were compared with those of 5500 Japanese placentas at Saitama Medical School since 1990. In this study, characteristics of ultrastructural features of the Nepalese placental villi investigated in recent years are reported. (1) The gross characteristics of placental pathology in the Himalayan group were represented by marked subchorionic fibrin deposits and increased chorionic cysts in contrast to low incidence of intervillous thrombosis compared with those of the Japanese group. (2) As characteristics of histological findings of the placental villi between Himalayan and Japanese groups, the incidence of chorangiosis and chorangioma in the Himalayan group was significantly higher than that in the Japanese group. (3) Accompanying an increase of vasculosyncytial membrane (VSM) in the villi, thickness and separation of basement membrane of the syncytium in addition to increased apoptosis of syncytial cell nuclei were recognized. (4) As characteristic ultrastructural features of chorionic villi of Nepalese placentas, an increase of mitochondria and cystic formation of rough endoplasmic reticulum (rER), in addition to appearance of lamellar bodies similar to alveolar epithelial type II cell in organellae of the syncytium, were observed. These ultrastructural changes of the placental villous capillaries may be ascribed to hypevascularization caused by the chronic hypoxic state. It is, therefore, presumed that trophoblast cells may play an important role for gas transfer mecha-nism under such a hypoxic state at high altitude.     

Effects of estrogen on susceptibility to oxidation of low-density and high-density lipoprotein in postmenopausal women

Objective: To investigate the effects of estrogen on the susceptibility to oxidation of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) in postmenopausal women. Methods: A total of 23 postmenopausal women were treated with 0.625 mg of conjugated equine estrogen daily for 3 months. Blood samples were obtained before and after therapy. Plasma levels of total cholesterol and triglyceride and the concentrations of cholesterol, triglyceride, phospholipid in LDL and HDL were determined enzymatically and the levels of apolipoprotein A-I, A-II in HDL and apolipoprotein B in LDL were measured by turbidimetric immunoassay. The isolated LDL and HDL were incubated at 37°C for 24 h with CuSO₄ 5 μmol/l and the lipid peroxide concentration of LDL and HDL was measured. Results: Estrogen significantly reduced the plasma level of total cholesterol and significantly increased the plasma level of triglyceride. The LDL concentrations of cholesterol, phospholipid and apolipoprotein B were significantly decreased following estrogen therapy. The triglyceride level of LDL did not change significantly. The HDL concentrations of cholesterol, triglyceride, phospholipid and apolipoprotein A-I and A-II were all significantly elevated after estrogen therapy. Estrogen significantly inhibited the peroxidation of LDL at 50–2000 μg of LDL protein (14.17±4.17–11.49±1.42 nmol/200 μg of LDL protein, P<0.001) and of HDL (4.49±1.74–3.37±1.24 nmol/200 μg of HDL protein, P<0.03) induced by their incubation in the presence of CuSO₄. Conclusions: Estrogen inhibited the susceptibility of LDL and HDL to oxidative modification and favorably affected lipid metabolism by reducing the number of LDL particles and increasing the number of HDL particles in plasma that were resistant to oxidation.     

Micropuncture studies on the filtration rate of single superficial and juxtamedullary glomeruli in the rat kidney

Summary Single nephron filtration rates of superficial and juxtamedullary nephrons were determined in high and low sodium rats. Single nephron GFR was calculated from TF/P inulin and tubular flow rate in superficial nephrons and single juxtamedullary GFR from corresponding data in long loops of Henle. In low sodium rats superficial nephron GFR was 23.5±6.4 (SD)×10^–6 ml/min×g KW, juxtamedullary nephron GFR was 58.2±13.6 and total kidney GFR (C _In) was 0.94±0.16 ml/min×g KW. Using these single nephron values, total kidney GFR and a total number of 30,000 glomeruli per kidney, the number of superficial and juxtamedullary glomeruli was calculated to be 23,267 and 6,733, respectively. During high sodium diet superficial nephron GFR increased to 38.1±11.3 and single juxtamedullary GFR decreased to 16.5±6.6, total kidney GFR increasing to 1.01±0.24. Calculation again revealed the same distribution of the two nephron types. End-proximal TF/P inulin in superficial nephrons was 2.36±0.36 in low sodium and 2.31±0.28 in high sodium rats. Loops of Henle TF/P inulin and intratubular flow rate were inversely related: the highest TF/P inulin values and lowest intratubular flow rates were found in the descending limb. These data quantify the distribution of superficial and juxtamedullary nephrons on a functional basis and suggest a mechanism by which the kidney adjusts sodium excretion by altering the contribution of each nephron type to total kidney GFR.Supported by the Deutsche Forschungsgemeinschaft and the U.S. Department of the Army, through its European Research Office.     

晚期结肠癌病人肠系膜淋巴结高内皮微静脉超微结构观察

目的：探讨晚期结肠癌病人肠系膜淋巴结内高内皮微静脉超微结构的变化及其对淋巴细胞进入肠系膜淋巴结的影响。方法：采用透射电镜观察晚期结肠癌病人肠系膜淋巴结内高内皮微静脉的超微结构。结果：晚期结肠癌病人的肠系膜淋巴结内，高内皮微静脉管壁内皮细胞的细胞核出现大量齿状切迹，细胞膜出现大量脂状突起。质膜小泡，AWeibel-Palade小体，高尔基复合体减少，线粒体多出现肿胀，扩张，部分基膜不完整。高内皮微静脉管壁内少见淋巴细胞穿越。结论：晚期结肠癌病人肠系膜淋巴结内，高内皮微静脉的超微结构受到不同程度的影响和破坏，导致淋巴细胞进入肠系膜淋巴结的能力减弱。     

纹状体源性神经营养因子的分离纯化和生物鉴定

纹状体是中脑黑质多巴胺神经元的主要靶组织，我们先前的研究曾指出，纹状体提取液能增一外培养的中脑黑质神经元的存活和发育，本研究是在此基础一步应用ＳｅｐｈａｄｅｘＧ－７５凝胶层析、高效液相色谱（ＨＰＬＣ）、反相高效液相色谱（Ｒ－ＨＰＬＣ），ＳＤＳ－ＰＡＧＥ等的分析，结合生物鉴定，从纹状体提取液中分离出化的活性因子－－纹关腐朽源性神经营养因子。该因子的分子量为１１．５ｋＤ，等电点为９．３９，它能促进体外     

Comparison of glutamate metabolism in low K (LK), high K and high glutathione (HK/HG) and high K and low glutathione (HK/LG) dog red blood cells

The reasons for the high accumulation of glutamate (Glu), aspartate (Asp) and glutamine (Gin) in high K and high glutathione (HK/HG) dog red blood cells (DRBCs) have been explained as due to enhanced Glu/Asp influxes. However, in our study, Glu/Asp influxes in high K and low glutathione (HK/LG) DRBCs were low, whereas their cellular Asp and Gin contents were high. In low K (LK) DRBCs, there were also other variant cells with high Asp accumulation, but extremely low Glu/Asp influxes. So, the high amino acid accumulation in DRBCs of these new variants might not be due to Glu/Asp influxes. To examine the high accumulation of these amino acids in these variant DRBCs, first, LK and HK/LG DRBCs were classified into two subgroups with their Na-dependent Glu/Asp influxes; one had clear Na-dependent Glu/Asp transport (GAT⁺), and the other failed to have any transport (GAT⁻). The influxes of both Glu and Asp in HK/HG DRBCs were the highest, and the order was HK/HG>LK/GAT⁺>HK/LG/GAT⁺>>LK/GAT⁻=HK/LG/GAT⁻. LK/GAT⁺ cells represented normal DRBCs. Glu/Asp influxes were only trace in both LK/GAT⁻ and HK/LG/GAT⁻ cells, but Glu and Asp concentration was high in HK/LG/GAT⁻ cells whereas Asp concentration was high in LK/GAT⁻ cells. In HK/HG cells, the conversion of Glu into Gin in whole cells was several fold higher than in the other cell groups due to the differing amount of the substrate of glutamine synthetase, Glu, but glutamine synthetase activity itself was not different among these cell groups. Furthermore, glutamine synthetase and glutaminase activities were not different among the cell groups. Therefore, these enzymes were not involved in the high amino acid accumulation.     

Studies of the antigenicity and allergenicity of phospholipase A2 of bee venom.

The antigenic and allergenic properties of phospholipase A2 (PLA2) and whole bee venom were compared by measuring the IgG and IgE antibody responses in animals and man. Precipitating antibodies raised in rabbits and reaginic and other antibodies raised in mice reacted about equally with both bee venom and PLA. The majority of human sera containing bee venom-specific IgE also contained PLA-specific IgE, although in somewhat lower titers. Similarly, most human sera with significant amounts of total antibodies reacting with bee venom also had antibodies reacting with PLA. Histamine and SRS-a release from leukocytes of sensitive patients followed challenge with whole bee venom and PLA in the majority of instances. However, mediator release from several patients' cells was obtained with bee venom only. These studies suggest that although PLA is a major allergen and antigen in bee venom, significant exceptions in patients' reactivity may limit its potential diagnostic and therapeutic usefulness.     

Insect venom allergy: a prospective case study showing lack of correlation between immunologic reactivity and clinical sensitivity

This case report demonstrates the lack of correlation between clinical sensitivity to insect venoms and immunologic reactivity as indicated by the presence of venom-specific IgE. A 20-yr-old venom collector was monitored over a 3-yr period with measurements of venom-specific IgE (skin test and RAST) and venom-specific IgG. In the first year of venom collection, multiple stings were tolerated with no reaction. In the second season, she had an anaphylactic reaction after a yellow jacket sting. Subsequently, there was a rising titer of serum yellow jacket and bee venom-specific IgE and positive skin-test reactions. In the third season, yellow jacket, hornet, and bee venom skin tests remained positive and serum IgE antibody titers remained elevated. Stings from all three insects were tolerated with no reaction. Throughout the 3-yr course, serum venom-specific IgG remained low and unchanged. The factors other than IgE-modulating clinical anaphylaxis, perhaps responsible for this clinical and immunologic dichotomy, are unknown. These observations add a further complication to the choice of patients for venom immunotherapy.     

Water intake during the development of renal hypertension (2K-1C) in mice

For both practical and methodological reasons, mice have been the most widely employed species for development of transgenic and gene knockin and knockout animals. However, basic behavioral and physiology control and regulatory mechanisms in mice are not well characterized. To broaden our understanding of the processes maintaining body fluid and blood pressure homeostasis in the mouse, the objectives of this study were to evaluate voluntary water, and sodium intakes during the development of renal hypertension and to examine the relationship between hypertension and the quantities of water and salt ingested. In male, C57BL/6J mice, two-kidney, one-clip renal hypertension (2K-1C) was induced, and water and 1.8% NaCl intakes were monitored for 2 weeks. At the end of this period, all animals received arterial catheters for direct recording of blood pressure. The mice that received renal artery clips were sorted into hypertensive (152+/-4 mm Hg) and normotensive (122+/-2 mm Hg) groups and were compared to control (117+/-4 mm Hg) animals that underwent a sham renal clipping procedure. Hypertensive 2K-1C animals had significantly elevated water intake compared to control animals. On most of the postsurgical days, the normotensive 2K-1C animals did not display increased water intake in comparison to the control group. No significant effect was detected for 1.8% saline intake between any of the pairs of groups. In summary, the reduction of blood flow to a single kidney in the 2K-1C model of renal hypertension induces high blood pressure accompanied by sustained hyperdipsia in the mouse.