Specific Agglutination of Human A3 and Ax Erythrocytes by Snail Anti-A

The anti-A lectin of the snail, Otala lactea , produced specific agglutination of human A₃ and A_x erythrocytes. The snail anti-A was specifically absorbed by these erythrocytes and the eluates showed anti-A activity.     

C5-6 Cervical Dislocation Resulting from Improper Seat Belt Use

Motorists may improperly use the diagonal shoulder belt of newer passive restraint systems by failing to use the lap belt. An unusual case of a patient who did not wear a lap belt and who sustained a cervical C_5–6 distraction injury resulting in quadriplegia is reported. Emergency physicians should be aware of this injury mechanism and should reinforce proper passive restraint use.     

MCL1 and MCL6 Compared to V1 and V6 in Distinguishing Aberrant Supraventricular from Ventricular Ectopic Beats

Use of V1 and V6 has been suggested for distinguishing aberrant supraventricular from ventricular ectopy. For two decades, "modified" leads MCL1 and MCL6 have been widely used as V1 and V6 substitutes for bedside monitoring, but their use has never been validated. To determine the value of MCL1 and MCL6, 81 morphologically distinct wide QRS ectopic beats were recorded from 46 patients during cardiac electrophysiological study. As determined by the His-bundle electrogram, 31 of the ectopics were aberrant supraventricular, 50 were ventricular. A new criterion, measurement of QRS onset to the predominant peak or nadir of the complex, was valuable in diagnosing wide complexes in MCL6 and V6. An interval of 50 msec or less predicted aberrant supraventricular ectopy; an interval of 70 msec or more predicted ventricular ectopy. There was agreement between the modified and conventional precordial leads regarding which QRS patterns were useful in distinguishing aberrant supraventricular from ventricular ectopy. A greater proportion of wide complexes in MCL1 and V1 exhibited patterns useful in making the diagnosis compared to MCL6 and V6. Using well-established criteria, the proportion of correct diagnoses that was made from individual leads was: MCL1 = 86%, V1 = 85%, MCL6 = 72%, V6 = 67%. The bedside leads (MCL1 and MCL6) were not statistically different in diagnostic accuracy from their conventional lead counterparts (V1 and V6); however, MCL1 and V1 were superior to MCL6 and V6. When the new criterion was added to make the diagnosis from MCL6 and V6, no difference in diagnostic accuracy was present between the four leads.     

The Frequency and Nature of Blood Group A3

A special survey of 20,826 random blood donor specimens collected in Ontario, Canada yielded one A₃ blood while a review of blood grouping worksheets of 158,000 individuals in this area also yielded one A₃ blood. These frequencies are much lower than the frequency found in Denmark around 1940 by Gammelgaard, 44 per 10⁵, perhaps due to the present availability of high titer immune anti-A. Elution studies on these two A₃ bloods show that both the agglutination-positive and the agglutination-negative cells absorb anti-A, indicating that A₃ is not always an A₂ + O mixture as has been suggested. Fluorescent antibody studies revealed a marked cell-to-cell variability in fluorescence and, therefore, presumably, cell A antigen content. This finding confirms Gammelgaard's earlier report. This variability, together with a threshold value of A antigen required for agglutination, could explain the characteristic appearance of A₃: agglutinates and free cells.     

Radioimmunoassay of Prostaglandins Fα, E1 and E2 in Human Plasma

Abstract. Antibodies against prostaglandins (PG)F₂α, E₁ and E₂ were obtained in rabbits immunized with respectively PG F₂α, PG E₁ and PG E₂ conjugated to bovine serum albumin by carbodiimide. A radioimmunoassay capable of measuring 7 pg of PG Fα, 2 pg of PG E₂ and 14 pg of PG Ej in human peripheral plasma is described. Plasma samples (pH 3, citric acid) are extracted with cyclohexane: ethyl acetate, 1:1 and then chromatographed on silicic acid columns to separate the prostaglandins into three fractions: fraction I, PG A, PG B and some unknown immunoraactive compounds; fraction II, PG E and fraction III PG Fα. The recovery is 80 %± 6. 2. Mean plasma levels iu adults of PG Fa and PG E, expressed in pg/ml: -PG Fα 12 ± 2. 8 (n = 25 men), 8 ± 2. 3 (n = 18 women, follicular phase), 7 ± 1. 4 (n = 18 women, luteal phase). -PG E₁ 40. 5 + 7. 6 (n = 13 men), 38 + 17. 1 (n = 10 women). -PG E₂ 4. 5 ± 1 (n = 12 adult subjects).
The major characteristics of the method described herein are the following: - a large volume of plasma has to be processed (10 ml or more for PG Fa and PG E₁, 5 ml or more for PG E₂). - a chromatographic step is necessary to separate the different prostaglandins which makes it possible to circumvent problems of immunological cross reactivity and interference with unknown immunoreactive compounds. - great care has been taken in collection of blood samples, especially to insure complete removal of blood cells namely platelets.     

A Comparative Observation of the Presence of Anti-Tja-like Hemolysins in Relation to Obstetric History, Distribution of the Various Blood Groups and the Occurrence of Immune Anti-A or Anti-B Hemolysins Among Aborters and Nonaborters

Four hundred and twenty-two mothers with histories of spontaneous abortion and 300 mothers without such histories were examined for their various red cell blood groups, substances in salivary secretions and for the presence of immune anti-A and anti-B hemolysins. These factors in the 722 patients were compared with the occurrence of anti-Tj^a-like hemolysins among aborters in Western Australia. Of significance was the observation that the presence of anti-Tj^a-like hemolysins was associated only with abortion while the presence of immune anti-A or anti-B hemolysins occurred more often in mothers with histories of stillbirths and neonatal deaths. The lower pregnancy rate observed among mothers possessing immune anti-A or anti-B hemolysins also suggests that infertility could be associated with the presence of these hemolysins.     

Endothelin-1 does not modulate O2· release and [Ca2+]i variations in resting or differentiated HL-60 cells

Summary— Endothelin-1 (ET-1) by itself was not an effective stimulus for inducing superoxide (O₂*) generation in human resting or DMSO-differentiated neutrophil-like HL-60 cells. ET-1 (0.01 – 100 nM) was not able to modulate O₂* generation stimulated by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP, EC₅₀ = 4.24 ± 1.63 nM in the absence and 3.16 ± 1.95 nM in the presence of ET-1). Neither did ET-1 (0.01 – 100 nM) promote the mobilization of intracellular calcium ions or modulate fMLP-induced [Ca²⁺]_i increase in this model of human neutrophils. Phosphoramidon, a neutral endopeptidase inhibitor, was not able to reveal any biological (O₂*) or biochemical ([Ca²⁺]_i) response to ET-1 in the absence or in the presence of fMLP in these cells. These results indicate that DMSO-differentiated neutrophil-like HL-60 cells are not sensitive to ET-1 in terms of O₂* generation or [Ca²⁺]_i variations.     

Isolation of a Substance with Blood -group P1 Activity from Human Erythrocyte Stroma

Lyophilized erythrocyte stroma were extracted with chloroform methanol, and a fraction with blood-group P₁ activity was obtained by chromatography on columns of silicic acid followed by preparative thin-layer chromatography. The active fraction contained at least two glycosphingolipids, and it is concluded, tentatively, that the erythrocyte P₁ antigen is a glycosphingolipid.     

Use of prostaglandin E1 during preparation of platelet concentrates

Summary. A paired study in 10 autologous volunteer donors was undertaken to investigate the efficacy of adding prostaglandin E₁ (PGE₁) in vitro during routine platelet concentrate (PC) production. After 5 days storage, PCs prepared with PGE₁ were compared with control PCs. In vivo platelet recovery, survival and biodistribution were determined following autologous infusion of indium-111 labelled platelets into volunteers, together with the in vitro evaluation of platelet function and biochemistry. PGE₁ facilitated easier and faster platelet resuspension following centrifugation. After storage there were few significant in vitro differences between PCs prepared with PGE₁ and control PCs. The artifactual leucocyte concentration was significantly lower in the presence of PGE₁, suggesting less platelet aggregates had been formed during storage and β-thromboglobulin release was significantly reduced by PGE₁, 14.0±6.0 μg per 10⁹platelets compared with 22.3±9.8μg per 10⁹platelets in control PCs, (P < 0.01), indicating PGE₁ reduced both platelet aggregation and activation probably at the initial preparation stage, known to produce the greatest trauma. Initial in vivo platelet recovery for PCs prepared with PGE₁ was similar to that of control PCs, 41.1 ± 12.5% vs. 44.4±80%, respectively, and there were no differences in organ distribution at 24h. However, in vivo multiple hit survival was reduced in the presence of PGE₁, 5.8 ± 1.6 days compared with 6.9 ± 1.4 days in control PCs (P < 0.05). Despite the ability of PGE₁ to facilitate platelet resuspension and inhibit platelet aggregation and activation during preparation of the PCs, the reduced in vivo survival time may preclude the use of PGE₁ during routine PC preparation.     

The A1 (B) phenomenon: a monoclonal anti-B (BS-85) demonstrates low levels of B determinants on A1 red cells

A monoclonal anti-B (BS 85) that reacts strongly with red cells from weak B variants (B3, Bint and Bv) has demonstrated the presence of a trace of B on A1 red cells. The agglutination of group A1 red cells by an anti-B antibody is called the A1 (B) phenomenon and is the converse of the B(A) phenomenon seen with certain monoclonal anti-A antibodies. Fragile A1 (B) agglutination is best seen by spin-tube techniques and A1 red cells negative in saline tests are agglutinated by albumin and protease enzyme-enhanced tests, but no reactions are seen with A2 red cells. The A1 (B) reaction is specifically inhibited by B substance, and D-galactose and the galactose-containing sugars melibiose and lactose. Red cells from B variants showed differential inhibition patterns with various sugars. A1 transferase levels were normal even in the strongest A1 (B) reactive blood samples, although the plasma H transferase levels and H status of these red cells were elevated. This is in contrast to the B(A) phenomenon which is associated with elevated levels of B transferase. It is suggested that A1(B) overlapping specificity can occur because of a combination of higher H activity (and thus more H sites) together with normal levels of A transferase activity as they are 20% higher than normal levels of B transferase. The production of anti-B reagents free of the A1 (B) phenomenon with BS-85 is achieved by suitable dilution using quality control tests with protease-treated A1 red cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pharmacological control of the human gastric histamine H2 receptor by famotidine: comparison with H1, H2 and H3 receptor agonists and antagonists

Histamine 0.1 microM-0.1 mM increased adenylate cyclase activity five- to ten-fold in human fundic membranes, with a potency Ka = 3 microM. The histamine dose-response curve was mimicked by the H3 receptor agonist (R) alpha-MeHA, but at 100 times lower potency, Ka = 0.3 mM. Histamine-induced adenylate cyclase activation was abolished by H2, H1 and H3 receptor antagonists, according to the following order of potency IC50: famotidine (0.3 microM) greater than triprolidine (0.1 mM) thioperamide (2 mM), respectively. Famotidine has no action on membrane components activating the adenylate cyclase system, including the Gs subunit of the enzyme stimulated by forskolin and cell surface receptors sensitive to isoproterenol (beta 2-type), PGE2 and VIP. The Schild plot was linear for famotidine (P less than 0.01) with a regression coefficient r = 0.678. The slope of the regression line was 0.64 and differs from unity. Accordingly, famotidine showed a slow onset of inhibition and dissociation from the H2 receptor in human cancerous HGT-1 cells. The results demonstrate that famotidine is a potent and selective H2 receptor antagonist with uncompetitive actions in human gastric mucosa. Consequently, famotidine might be a suitable drug with long-lasting actions in the treatment of Zollinger-Ellison syndrome. The results also confirm and extend the previous observations that (R) alpha-MeHA and thioperamide are two selective ligands at histamine H3 receptor sites. In the human gastric mucosa, these drugs are respectively 330 and 6700 times less potent than histamine and famotidine on the adenylate cyclase system. The possible involvement of histamine H3 receptors in the regulation of gastric secretion is proposed.     

The 13C-mixed triglyceride breath test in healthy adults: determinants of the 13CO2 response

Defects in lipolysis due to pancreatic insufficiency can be diagnosed by the mixed triglyceride (MTG) ¹³CO₂ breath test. However, the effects of various test conditions on the ¹³CO₂ response have only been partially elucidated. In healthy adults, we performed the ¹³CO₂ mixed triglyceride breath test and we compared (a) the inter- and intra-individual variation in the ¹³CO₂ response; (b) the effect of two different test meals; (c) the effect of an additional meal during the test; and (d) the effect of physical exercise during the test. Upon repeating the test in the same individual (test meal cream), repeatability coefficients were large, with respect to either time to maximum ¹³C excretion rate (3.8 h), maximum ¹³C excretion rate (4.9% ¹³C dose h^?1) or cumulative recovery of ¹³C over the 9-h study period (22.7% ¹³C dose). The cumulative ¹³C expiration over 9 h obtained with the test meal composed of cream was quantitatively similar to that obtained with bread and butter: 42.2 ± 8.4% and 47.7 ± 6.3% respectively. Fasting for 9 h during the test resulted in similar ¹³C expiration rates and cumulative ¹³C expiration (43.4% ± 7.2%) when compared with consumption of an additional meal 3 h after the start of the test (38.3 ± 5.3%). The ¹³CO₂ response increased in five out of seven subjects, but decreased in the other two, when moderate exercise was performed (bicycle ergometer, 50 W for 5 h). We conclude that the repeatability of the MTG test in healthy adults is low. The present results indicate that a solid and a liquid test meal, containing a similar amount of fats, give similar cumulative ¹³CO₂ responses, and that stringent prolonged fasting during the test is unnecessary. Standardization of physical activity seems preferable, since the unequivocal effects of moderate exercise on the ¹³CO₂ response were observed in the individuals studied.     

Visualization of C7-T1 on Portable Lateral Cervical Spine Radiographs Using a Lead-lined Acrylic Filter

Objective: To determine whether lead-lined acrylic cervical filters can improve the quality of portable lateral cervical spine (c-spine) radiographs for trauma patients.
Methods: Twenty trauma patients who required portable c-spine x-rays had these taken with a lead filter attached to the collimator of the portable x-ray machine to improve penetration and visualization of lower cervical structures without overpenetrating upper cervical structures. The radiographs of these patients were compared with the first portable c-spine radiographs without filters for 20 controls matched for gender and injury severity. The comparison of radiographs was done by an experienced emergency physician and a neuroradiologist blinded to whether the filter was used.
Results: The two groups were similar for demographic and clinical characteristics. There was a significant improvement in the ability to visualize the C₇-T₁ level for the filter group compared with the control group (65% vs 30%, p < 0.05). Agreement between the physicians was excellent (kappa = 0.79, 95% CI = 0.60-0.99).
Conclusions: Lead-lined acrylic filters improve the ability to visualize the lower c-spine in trauma patients.     

Blood group A antigen expression in platelets is prominently associated with glycoprotein Ib and IIb. Evidence for an A1/A2 difference

Blood group ABH antigens are associated with platelets as intrinsic determinants and extrinsically adsorbed antigens, and exist both on glycosphingolipids and on glycoproteins (GPs). We now provide direct evidence that the blood group ABH antigens are prominently associated with platelet GPIb and GPIIb. By immunoprecipitation, a murine monoclonal anti-A antibody precipitated surface-biotin-labelled blood group A₁ platelet membrane proteins with electrophoretic characteristics identical to those of GPIb/IX and GPIIb/IIIa. By immunoblotting of SDS-PAGE separated blood group A₁ platelet proteins the monoclonal anti-A antibody bound to proteins with electrophoretic characteristics identical to those of GPIb and GPIIb. When immunoaffinity purified GPIb/IX and GPIIb/IIIa, derived from blood group O, A₁ and A₂ platelets, were employed for immunoblotting, GPIb and GPIIb only from A₁ platelets bound the monoclonal anti-A antibody. By ELISA, wherein monoclonal antibodies specific for GPIb (AP1) and the GPIIb/IIIa complex (AP2) were used to capture and hold antigens from platelet lysate, human anti-A antibodies reacted with these proteins derived from blood group A₁ platelets; proteins from blood group A₂, O and B platelets showed no reactivity. These results indicate that blood group A antigen is associated with GPIb and GPIIb derived from blood group A₁ but not A₂ platelets.     

临床与环境标本分离的大肠埃希菌blaCTX-M-14基因环境和菌株同源性分析

目的分析临床与环境标本分离的大肠埃希菌blaCTX-M-14基因环境和菌株同源性。方法收集2014年6月至2014年8月我院临床与环境标本分离的大肠埃希菌共255株,PhoenixTM-100鉴定细菌种类并测定最小抑菌浓度,纸片扩散法测定超广谱β-内酰胺酶表型,PCR扩增blaCTX-M-14基因;接合实验、质粒复制子分型分析质粒特征;脉冲场凝胶电泳和多位点序列分型对菌株分型。结果 blaCTX-M-14基因的阳性共26株。多数菌株(42.3%,11/26)含有F型质粒,且多具有可转移性。多位点序列分型多为ST131(30.8%,8/26)。仅有4株菌能在环境或大便标本中找到同源株。多数菌株(61.5%,16/26)blaCTX-M-14基因环境均具有相同的模式:上游有ISEcp1,同时下游有IS903。结论 blaCTX-M-14基因可通过医院环境或体内移位获得,但其广泛传播的原因可能与其编码在F型质粒上及其基因环境中存在ISEcp1和IS903有关。     

Critical role of ADP interaction with P2Y12 receptor in the maintenance of αIIbβ3 activation: association with Rap1B activation

OBJECTIVE: Platelet integrin alpha(IIb)beta3 plays a crucial role in platelet aggregation, and the affinity of alpha(IIb)beta3 for fibrinogen is dynamically regulated. Employing modified ligand-binding assays, we analyzed the mechanism by which alpha(IIb)beta3 maintains its high-affinity state. METHODS AND RESULTS: Washed platelets adjusted to 50 x 10(3) microL(-1) were stimulated with 0.2 U mL(-1) thrombin or 5 microm U46619 under static conditions. After the completion of alpha(IIb)beta3 activation and granule secretion, different kinds of antagonists were added to the activated platelets. The activated alpha(IIb)beta3 was then detected by fluorescein isothiocyanate (FITC)-labeled PAC1. The addition of 1 mum AR-C69931MX (a P2Y12 antagonist) or 1 mm A3P5P (a P2Y1 antagonist) disrupted the sustained alpha(IIb)beta3 activation by approximately 92% and approximately 38%, respectively, without inhibiting CD62P or CD63 expression. Dilution of the platelet preparation to 500 microL(-1) also disrupted the sustained alpha(IIb)beta3 activation, and the disruption by such dilution was abrogated by the addition of exogenous adenosine 5'-diphosphate (ADP) in a dose-dependent fashion. The amounts of ADP released from activated platelets determined by high-performance liquid chromatography were compatible with the amounts of exogenous ADP required for the restoration. We next examined the effects of antagonists on protein kinase C (PKC) and Rap1B activation induced by 0.2 U mL(-1) thrombin. Thrombin induced long-lasting PKC and Rap1B activation. AR-C69931MX markedly inhibited Rap1B activation without inhibiting PKC activation. CONCLUSIONS: Our data indicate that the continuous interaction between released ADP and P2Y12 is critical for the maintenance of alpha(IIb)beta3 activation.     

Basophil Histamine Release and Leukotriene (LTB4 - LTC4) Production in Cluster Headache

Histamine release and leukotrienes (LTB4 and LTC4) production from circulating basophil have been studied in 13 patients with episodic cluster headache (CH) during the remission phase of symptoms, and in 9 normal subjects. Cell suspensions of basophils were stimulated with scalar dilutions of anti-IgE, f-met-peptide and Ca2+ ionophore A23187. Histamine was measured by an automated fluorimetric method; LTB4 and LTC4 with RIA in individual cases, and with Reverse-Phase HPLC in the two pools obtained from the supernatants of CH patients and controls. Mean values of histamine release in patients with CH were significantly lower when compared to those obtained in control subjects after stimulation with anti-IgE at the three dilutions used. LTC4 mean levels measured in CH patients were significantly lower than those of supernatants from controls after stimulation with 0.05 gamma/ml of A23187. A reduction of LTC4 and LTB4 levels in CH patients was also observed in R-P HPLC, which showed different elution patterns in the two groups. The histamine release in individual cases was related to leukotriene production: LTC4 levels were significantly (p less than .05) higher in "high histamine releasers" than in "low histamine releasers". Our results indicate that CH patients have complex abnormalities of histamine release and of leukotriene production during the painless phase of the disease.     

Increase in PGE2 and TXA2 in the Saliva of Common Migraine Patients. Action of Calcium Channel Blockers

PGE2 and TXA2 levels and their modulation by nicardipine, a calcium blocking agent, have been studied in patients suffering from migraine. The levels of both metabolites were determined in saliva obtained during the migraine attacks, during the intervals between attacks, and after 2 months of treatment with nicardipine (20 mg every 8 h.) or placebo. The therapeutic response was evaluated on the basis of the number of migraine attacks. The results show a significant increase in the levels of both eicosanoids during the migraine attacks. In contrast to the placebo group, the number of migraine attacks and the levels of both arachidonic acid metabolites are markedly lower in the nicardipine group. Our results suggest calcium entry into the cytosol as an explanation for the increase in PGE2 and TXA2. Nicardipine interferes with calcium mobilization, thereby inhibiting arachidonic acid metabolite synthesis.     

No decrease of 1,25(OH)2D3 receptors and duodenal calbindin-D9k in uraemic rats

In parathyroids of uraemic patients or animals, decreased specific binding of 1,25(OH)2D3 has been observed and implicated in the genesis of secondary hyperparathyroidism of renal failure. We re-examined binding of 1,25(OH)2D3 using chromatin preparations for receptor characterization which differed from previous studies (a) by inclusion of protease inhibitors (PMSF, aprotinin) and molybdate in the extraction buffer and (b) by omitting the K-extraction step. With this method, the Nmax in the intestinal mucosa and parathyroids of uraemic animals was significantly higher, while the receptor sedimentation constant (S), DNA affinity and KD were all unchanged. The ratio of occupied to total receptors was not significantly altered. The regulation of 1,25(OH)2D3 receptors in response to acute injection of 1,25(OH)2D3 was abnormal. Calbindin-D9k concentration in the intestines of uraemic and control rats was comparable both before and after administration of 1,25(OH)2D3. The present data demonstrate (a) increased 1,25(OH)2D3 receptors and (b) unchanged 1,25(OH)2D3-dependent synthesis of calcium binding protein (CaBP) in experimental uraemia.