Defining an antigenic epitope on platelet factor 4 associated with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a potentially serious complication of heparin therapy. Antibodies to platelet factor 4 (PF4)/heparin complexes have been implicated in the pathogenesis of this disorder, but the antigenic epitope(s) on the protein have not been defined. To address this issue, we studied the binding of HIT antibodies to a series of recombinant proteins containing either point mutations in PF4 or chimeras containing various domains of PF4 and the related protein, neutrophil activating peptide-2 (NAP-2). Serum samples from 50 patients with a positive 14C-serotonin release assay (14C-SRA) and a clinical diagnosis of HIT and 20 normal controls were studied. HIT antibodies reacted strongly with wild-type (WT) PF4/heparin complexes, but reacted little, if at all, with NAP-2/heparin complexes (optical density [OD]405 = 2.5 and 0.2, respectively). Alanine substitutions at three of the four lysine residues implicated in heparin binding, K62, K65, and K66, had little effect on recognition by HIT antibodies (OD405 = 2.2, 2.8, and 2.0, respectively), whereas an alanine substitution at position K61 led to reduced, but still significant binding (OD405 = 1.0). Similar studies involving chimeras between PF4 and NAP-2 localized a major antigenic site to the region between the third and fourth cysteine residues for more than half of the sera tested. This site appears to involve a series of amino acids immediately after the third cysteine residue beginning with P37. Thus our studies suggest that whereas the C-terminal lysine residues of PF4 are important for heparin binding, they do not comprise a critical antigenic site for most HIT antibodies. Rather, we propose that maintaining a region near the third cysteine residue of PF4, distal from the proposed heparin-binding domain, is required to form the epitope recognized by many HIT antibodies.

[Short-term effects of air pollution on lung function of school-age children in Hangzhou]

A total of 1 685 school-age children selected from Hangzhou received lung function testing to evaluate the short-term effects of air pollution on their lung function. The results showed that in every 10 μg/m(3) increase of average concentration of PM(2.5) and PM(10) on the day of the test and the day before the test,peak expiratory flow (PEF) decreased 0.039 (95%CI: 0.012-0.067) L/s and 0.031 (95% CI:0.011-0.051) L/s,respectively. When the average concentration of SO(2) increased 10 μg/m(3) on the day of test and the day prior to the test, PEF and 75% of the forced vital capacity that has not been exhaled (MEF(75)) decreased 0.437 (95%CI: 0.217-0.658) L/s and 0.396 (95%CI: 0.180-0.613) L/s. After being adjusted for NO(2),with every 10 μg/m(3) increase of average concentration of PM(2.5) and PM(10) on the day of the test and the day before the test,PEF and MEF(75) decreased 0.056 (95%CI: 0.028-0.085), 0.053(95%CI: 0.027-0.081) and 0.047 (95%CI: 0.026-0.068) L/s,0.044 (95%CI: 0.023-0.065) L/s on the day before the test, respectively. The results indicate that air pollution have short-term and lag effects on lung function of school-age children in Hangzhou.

Partial restoration of inactivated ribosomes: role of the aldehyde group generated by RNA N-glycosidase in the sarcin/ricin domain of 28S rRNA in ribosome

In this paper, we report more information on the important role of the aldehyde group in the sarcin/ricin domain of 28S rRNA in rat liver ribosome. We find D-amino acids, amino acid derivatives having free amino group and two polyamines can also partially restore the activity of cinnamomin-inactivated ribosomes. However, amino acid derivatives and a tripeptide with blocked amino group cannot. Neither sodium borohydride nor the L-amino acids can restore the activity of ribosomes inactivated by alpha-sarcin. These data demonstrate that partial restoration of the activity of the inactivated ribosome is indeed the result of the blockage of the aldehyde group. It reaches the conclusion that emergence of the active aldehyde group in the sarcin/ricin domain of 28S rRNA is one of factors that inactivate the ribosome for protein synthesis.

A study of retentive filler and its use in dentistry

OBJECTIVE

The purpose of this study was to develop a fine compound inorganic filler with special surface microstructure (called retentive filler or RF) and to investigate its use in composite resin and synthetic resin teeth.

METHODS

Barium silicate glass and fine silicon dioxide or barium silicate glass were mixed and sintered, then dispersed and classified by sedimentation. The surface microstructure and the particle size distribution of retentive filler were surveyed, and the mechanical properties of the composite resin and the resin tooth material reinforced with RF were tested.

RESULTS

Scanning electron microscopy showed that the surface of RF particles is distinguished for its retentive contour microstructure. The particle size of RF is smaller than 3 microns. The mechanical properties of composite resin reinforced with RF are better than that of composites containing normal fillers, and the wear resistance of the resin tooth material containing RF is better than that of normal synthetic resin.

CONCLUSIONS

The RF can be successfully prepared by the technological process in this study. Because of the special surface microstructure, RF has a good bonding to the resin matrix. The testing results suggest that it is feasible to improve the mechanical properties, especially the wear resistance of the composite resin and resin teeth, by using retentive filler.

[Two new glycosides from Erigeron breviscapus (Vant.) Hand.-Mazz]

OBJECTIVE

To study the chemical constituents from the upground part of Erigeron breviscapus.

METHOD

The compounds were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and 2D-NMR.

RESULT

Two new compounds were isolated and identified as 5,4'-dihydroxy flavonod-7-O-beta-D-pyranglycuronate buthyl ester(VI) and 3,5-dimethoxy benzene carbonic acid-4-O-beta-D-pyranglucose(VII).

CONCLUSION

Compounds VI and VII were new compounds.

[Immunomodulatory effect of oyster peptide on immunosuppressed mice]

OBJECTIVE

To evaluate the immunomodulating effect of oyster peptide on immunosuppressed mice.

METHODS

ICR mice injected with cyclophosphamide (CTX) were adopted as the module group, with mice without treatment as the control group, and different dosages of oyster peptide (0.5 g/kg, 1.0 g/kg, and 2.0 g/kg) were given to the low, middle, and high groups for 15 days. The body weight, spleen, and thymus weight of the mice, structures under the microscope of the immune organs, numbers of white blood cells, ratios of T lymphocyte subsets, immune cytokines and numbers of nuclear cells, and DNA content in bone marrow were all assessed.

RESULTS

Compared with the control group, the structures of thymus and spleen of the mice in the CTX group appeared obscure and shrunk when observed under microscope, the number of their white blood cells declined (P=0.04), the proportion of their CD3(+) T cells in peripheral blood declined (P=0.003), the proportion of their CD8(+) T cells in peripheral blood declined (P=0.002), the concentration of their IL-5 in peripheral blood significantly increased (P<0.01), the concentration of their nucleated cells and DNA density in bone marrow decreased (P=0.04, P<0.01). Oyster could improve the structures of thymus and spleen of the immunosuppressed mice. Compared with the CTX group, the number of white blood cells in 2.0 g/kg group increased (P=0.003), the proportion of CD3(+) T cells in peripheral blood in 1.0 g/kg group (P=0.04) and 2.0 g/kg group (P=0.02) increased, the proportion of CD8(+) T cells in peripheral blood in 2.0 g/kg group increased (P=0.002), the concentration of IL-5 in peripheral blood in all the oyster treated groups increased (P<0.01 in 0.5 g/kg, 1.0 g/kg, and 2.0 g/kg groups), the concentration of IL-17 in peripheral blood in 2.0 g/kg group decreased (P=0.03), the concentration of nucleated cells in bone marrow of all the oyster treated groups increased (0.5 g/kg vs. CTX, P=0.04; 1.0 g/kg vs. CTX, P=0.02; 2.0 g/kg vs. CTX P=0.01), the DNA content in bone marrow of all the oyster treated groups increased (P<0.01 in the 0.5 g/kg, 1.0 g/kg, and 2.0 g/kg groups).

CONCLUSION

Oyster peptide could improve the structures of immune organs of the CTX-induced immunosuppressed mice, recover the imbalances of T lymphocyte subsets, improve the immune cytokines and increase numbers of nucleated cells and DNA content in bone marrow, thus improving the immunologic function.

[Screening of periodontal and salivary parameters in patients with frequent acute exacerbation of chronic obstructive pulmonary disease]

Objective: To screen the risk factors of patients with frequent acute exacerbation of chronic obstructive pulmonary disease (COPD) by detecting the clinical indicators of periodontitis and the level of bacterial and inflammatory markers in saliva. Methods: Thirty-eight COPD patients in their stable period were recruited and detected from Beijing Chao-Yang Hospital,Capital Medical University during December 2016 to May 2017. The periodontal index were recorded. The levels of inflammatory factors in saliva samples were examined by using enzyme linked immunosorbent assay (ELISA). The bacteria composition in the saliva samples were identified by using 16SrRNA gene pyrosequencing. All patients were followed up and monitored for acute exacerbation of COPD for 12 months. The patients were divided into frequent acute exacerbation group (≥2 times/year, n=10) and non frequent acute exacerbation group (<2 times/year, n=28). Results: In univariate analysis, the patients' average age of frequent acute exacerbation group (69.0±7.3) was significantly older than that of non-frequent acute exacerbation group (61.8±8.3) (P=0.02). The numbers of remaining teeth ≤26 [100% (10/10)] was significantly higher and plaque index ≤2.5 (2/10) in frequent acute exacerbation group was significantly lower compared with the remaining teeth ≤26 [43% (12/28)] and the plaque index ≤2.5 [71% (21/28)] in non-frequent acute exacerbation group (P=0.02, P=0.01). The proportions of salivary inflammatory factors interleukin-6 (IL-6) level ≤60 ng/L (10%),C-reactive protein (CRP) level ≤1 550 μg/L (30%), matrix metalloproteinase-8 (MMP-8) level ≤140 μg/L (30%) and fibrinogen level ≤90 mg/L (30%) in frequent acute exacerbation group were significantly lower compared with salivary inflammatory factors IL-6 level ≤60 ng/L (71%),CRP level ≤1 550 μg/L (71%), MMP-8 level ≤140 μg/L (86%) and fibrinogen level ≤90 mg/L (71%) in non-frequent acute exacerbation group (P<0.05). The differences of relative abundances of salivary bacteria,such as species of Chloroflexi, Anaerolineae, Anaeroales, Corynebacteriales, Anaerolineaceae, Tissierellaceae, Leptotrichiaceae, Corynebacteriaceae, Leptotrichia, Moryella, Lachnoanaerobaculum and Corynebacterium between frequent acute exacerbation group and non-frequent acute exacerbation group were significantly different (P<0.05). In multivariate logistics regression analysis,the level of IL-6 >60 ng/L and the relative abundance of Corynebacteriales >0.2 had significant difference (P<0.05). Conclusions: The level of IL-6 and the relative abundance of Corynebacteriales might be the markers of frequent acute exacerbation in COPD patients.

[Studies on flavone constituents of Erigeron breviscapus (Vant.) Hand.-Mazz]

OBJECTIVE

To study the chemical constituents of Erigeron breviscapus.

METHOD

The constituents were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and physical data.

RESULT

Five compounds were isolated and identified as 3, 5, 6, 4'-tetrahydroxy-7-methoxy flavonoid(I); 5, 7, 4'-trihydroxy flavonoid(II); 3, 5, 6, 7, 4'-pentahydroxy flavonoid(III); scutellarein (IV) and 5, 7, 4'-trihydroxy flavanone(V).

CONCLUSION

Compounds I, III and V were isolated from this plant for the first time.

Prevention of myocardial reperfusion injury with free radical scavengers. An experimental study

The changes in endogenous superoxide dismutase (ESOD) during myocardial ischemia and reperfusion and the efficacy of oxygen free radical scavengers in myocardial protection were investigated in an isolated heart model connected with the recirculating nonpulsatile perfusion circuit. Subjected to a 2-hour period of global ischemia (27 C), the heart was reperfused with 37 C oxygen diluted auto-blood for 60 minutes. Superoxide dismutase plus catalase was added into the cardioplegic solution and reperfusates. ESOD activity was measured by pyrogallol method. The results of the experiment showed that ESOD activity after ischemia and reperfusion was decreased and the addition of oxygen free radical scavengers (SOD and CAT) to the cardioplegic solution and the reperfusates greatly reduced the leakage of myocardial enzymes, coronary vascular resistance, and the ultrastructural damages of the myocardium. These results suggest that the use of SOD and CAT may inhibit myocardial reperfusion injury by scavenging oxygen-derived free radicals.

Transcripts of the insulin-like growth factors I and II in human hepatoma

Using complementary DNAs of human insulin-like growth factors as probes, expressions of the insulin-like growth factors I and II mRNA were examined in seven human hepatoma tissues and their adjacent nontumorous livers. The level of insulin-like growth factor I mRNA in hepatoma was lower than that in the nontumorous liver control. This phenomenon was probably caused by the low expression of human growth hormone receptor in hepatoma tissues. The levels of insulin-like growth factor II mRNA vary among hepatomas. Some show elevated expression; some have diminished expression compared to their nontumorous liver counterparts. In four of the seven hepatomas, expression of fetal forms of insulin-like growth factor II transcripts was observed and may represent dedifferentiation of insulin-like growth factor II expression during hepatocarcinogenesis.

[Effect of acupuncture of zusanli (St. 36) on the content of beta-endorphin of the gastrointestinal tract in rats]

The present study attempts to search the mechanism with which Zusanli regulates the gastrointestinal function by using radioimmunoassay to measure the contents of immunoreactive beta-endorphin (ir-beta-Ep) in gastrointestine, anterior lobe of the pituitary and plasma of the rats after electro-acupuncture of Zusanli. The findings showed that the contents of ir-beta-Ep in the gastroparietal mucous membrane, pyloric mucous membrane, duodenum, jejunum and ileum were significantly elevated 30 min after electro-acupuncture of Zusanli. But the contents of ir-beta-Ep in the anterior lobe of the pituitary and plasma were not changed. These results suggested that it may be through the endogenous opiate peptides in gastrointestine that Zusanli regulates the function of the gastrointestinal tract.

[The role of central oxytocin in electroacupuncture analgesia]

The effects of intraventricular injection (ICV) of oxytocin (OT) and antioxytocin serum (AOTS) on the pain threshold and electroacupuncture (EA) analgesia in rats were investigated in this study. The potassium iontophoresis induced tailflick was used to measure the pain threshold. An increase of 20-38% in the pain threshold was observed within 80 min after OT injection (50 ng), while the OT administration (50 ng) in combination with EA produced a dramatic increase of 139-234% in the pain threshold, which was much higher than that in the saline-EA group (P less than 0.05 or 0.01). The OT effect was dose-related in the range between 25-100 ng. Although ICV of AOTS did not change the pain threshold, the EA analgesia became weakened significantly. After injection of AOTS, EA only produced an increase of 47-61% in the pain threshold, while following ICV injection of normal rabbit serum instead of AOTS the EA could cause a rise of 104-123% in the pain threshold. There was a significantly statistical difference between the above two groups (P less than 0.05-0.01). The data indicate that ICV of OT not only elevates the pain threshold, but also enhances the EA effect, and that AOTS attenuates the EA analgesia. These results suggest that endogenous oxytocin in the central nervous system may play a role in the electroacupuncture analgesia.

The interaction between "R/S domain" of rat 28S ribosomal RNA and ribosome-inactivating proteins investigated by fusidic acid

The interaction between "R/S domain" of rat 28S rRNA and ribosome-inactivating proteins (RIPs) has been studied by blocking the action site of RIPs on "R/S domain" of 28S rRNA with fusidic acid or S100. Fusidic acid alone could form stable complexes with rat ribosomes and block the action site of RNA N-glycosidases. incubation of fusidic acid and S100 or GDP with ribosomes could also protect ribosomes from the action of ricin A-chain. However, different effect of fusidic acid, S100 an dGDP was observed when alpha-sarcin was used. Fusidic acid alone could not block the action site of alpha-sarcin. Fusidic acid together with the elongation factors in S100 could block the action site of alpha-sarcin. These results are consistent with the previous report that ricin A-chain and alpha-sarcin recognized different conformation of "R/S domain" in rat 28S rRNA.

Primary aldosteronism due to unilateral adrenal hyperplasia: a case report

Primary aldosteronism is one of the differential diagnosis of secondary hypertension. This is usually caused by an aldosterone producing adenoma or bilateral adrenal hyperplasia which comprise about 65% and 30% of the cases, respectively. However, less than 1% of primary aldosteronism is caused by unilateral adrenal hyperplasia which is a relatively rare subset of primary aldosteronism. The clinical and biochemical manifestations of the disorder are indistinguishable from aldosterone-producing tumor, and a definitive diagnosis can only be made by pathological finding. A 33-year-old male Chinese patient presented with hypertension, hypokalemia, metabolic alkalosis, and the hypersecretion of aldosterone associated with suppressed plasma renin activity which is a typical hallmark of primary aldosteronism. Image studies including both magnetic resonance imaging (MRI) and 131I NIP-59 scan as well as postural test suggested an aldosterone-producing tumor of the right adrenal gland. Unilateral adrenectomy and pathological examination of the right adrenal gland eventually proved a case of unilateral adrenal hyperplasia. Blood pressure, plasma potassium, aldosterone and renin activity levels returned to normal two weeks after operation and had remained normal at up to one year of follow up. In addition, a saline loading test showed normal suppression of plasma aldosterone level one year after the operation, suggesting that the function of the left adrenal gland remains normal. The etiology of unilateral adrenal hyperplasia is unclear and the future recurrence of the disease is possible. Long-term follow-up is necessary to ensure the cure of this disorder.

[The analysis of the value of spontaneous nystagmus in peripheral vestibular hypofunction]

Objective:To study the characteristics and clinical value of spontaneous nystagmus in patients with peripheral vestibular dysfunction.Method:Sixty cases with acute unilateral peripheral vestibular dysfunction were studied.All were diagnozed as vestibular neuritis(VN) . The relationship between SN and disease duration,DP and UW were analyzed.Result:SN was present in49 patients(81.7%)and absent in the remaining 11(18.3%).The intensity of SN ranged from 0.5°/s-20.4°/s and had negative correlation with the disease duration(r=-0.478，P<0.01). The patients were divided into 3 groups (mild,medium and severe) according to SN intensity,with median duration of disease being 6.5 d，5 d and 3 d respectively. The difference between groups was statistically significant(χ²=9.071，P<0.01).The result of the caloric test were as following：caloric test revealed DP in 44 cases（89.8%） of SN ;DP values were normal in 8 cases（10.2%）;SN intensity was positively correlated with DP value（r=0.513,P<0.01） ;unilateral weakness was found in 35 cases（71.4%）,with the direction of SN towards the weakness side in 4 cases and towards the opposite direction in the remaining 31 cases; 7 cases（14.3%）had bilateral weakness and 7 cases（14.3%）normal. There were no relationship between the intensity of SN and UW value（r=-0.321,P>0.05）.The UW value of patients with SN (40.9±26.3）% was compared to the group without SN（29.9±18.2）% . The difference was statistically significant (F=4.497,P<0.05).Conclusion:The intensity of SN in patients with acute unilateral peripheral vestibular dysfunction was often moderate and severe. The intensity of SN waned as the disease progressed or the direction reversed,The vestibular injury in patient with SN was more severe than those without. SN is useful in clinical assessment of vestibular injury and compensatory status.

[Neurological complications after three-column osteotomy in spinal deformity patients with different magnetic resonance imaging -based classification of spinal cord shape]

Objective: To compare the incidences of neurological complications after three-column osteotomy based on the magnetic resonance imaging(MRI)-based classification of spinal cord shape and cerebrospinal fluid in patients with severe thoracic kyphoscoliosis. Methods: A total of 112 patients (52 males, 60 females, age (M(Q₁,Q₃)) 13.5 years (9.0-38.5 years)) with thoracic kyphoscoliosis who underwent three-column osteotomy in Nanjing Drum Tower Hospital from August 2015 to August 2018 were retrospectively analyzed. The radiographic parameters including spinal cord morphology at apex, Cobb angle of main curve, distance between C₇ plumb line and center sacral vertical line (C₇PL-CSVL), global kyphosis (GK) and sagittal vertical axis (SVA) were measured, retrospectively. The Frankel scoring system was used for the evaluation of neurological status at pre-operation, post-operation and the last follow-up. Results: The spinal cord morphologies at apex were classified into type Ⅰ in 8 (7.1%) patients, type Ⅱ in 58 (51.8%), and type Ⅲ in 46 (41.1%), respectively. The patients were followed-up for (28.5±3.4) months. Compared with pre-operation, the Cobb angle of main curve, C₇PL-CSVL, GK and SVA showed significantly improvement at post-operation (all P<0.05) and with no significant correction loss at the last follow-up (all P>0.05). New neurological complications were detected in 3 patients with type Ⅱ spinal cord shape, of whom the neurological scores were Frankel D at post-operation. For patients with type Ⅲ spinal cord shape, new neurological complications were detected in 6 patients including 1 Frankel C and 5 Frankel D. In addition, deterioration of neurological status from Frankel D to Frankel C was found in 3 patients with type Ⅲ spinal cord shape. The incidence of new or deteriorating neurological complications in patients with type Ⅲ spinal cord shape was higher than that in type Ⅱ patients (19.6% vs 5.2%, P=0.037). Conclusions: The MRI-based classification is associated with post-operative neurological complications in patients with severe kyphoscoliosis undergoing three-column osteotomy. Patients with type Ⅲ spinal cord shape are at higher risk of post-operative neurological complications.

[Effect of Echinococcus granulosus hydatid cyst fluid protein on allergic rhinitis induced by ovalbumin in mice]

OBJECTIVE

To investigate the protective effect of Echinococcus granulosus hydatid cyst fluid protein (HCFP) on ovalbumin (OVA)-induced allergic rhinitis (AR) in mice.

METHODS

Twenty-four BALB/c mice at ages of 8 to 10 weeks, each weighing approximately 20 g, were randomly divided into four groups, including groups A (blank control group), B (blank intervention group), C (AR model group) and D (AR+HCFP intervention group), with 6 mice in each group. On days 0, 2, 4, 6, 8, 10 and 12, mice in groups A, B, C and D were injected with 200 μL sterile phosphate buffered saline (PBS), 200 μL sterile PBS containing 20 μg HCFP, 200 μL sterile PBS containing 50 μg OVA and 5 mg Al(OH)₃ gel, and 200 μL sterile PBS containing 50 μg OVA, 5 mg Al(OH)₃ gel and 20 μg HCFP, respectively. On days 14 to 20, mice in groups A, B, C and D were administered with 40 μL sterile PBS, 40 μL sterile PBS containing 20 μg HCFP, 40 μL sterile PBS containing 2 mg OVA and 40 μL sterile PBS containing 2 mg OVA and 20 μL HCFP by nasal drop, respectively. Mouse behavioral changes were observed and behavioral scores were estimated. The serum levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-5, IL-10, transforming growth factor-β (TGF-β) and OVA-specific IgE antibody (OVA-sIgE) were measured using enzyme-linked immunosorbent assay (ELISA), and the pathological changes of mouse nasal mucosa were observed by hematoxylin and eosin (HE) staining.

RESULTS

The mean behavioral score was significantly greater in Group C (6.83 ± 0.50) than in groups A (1.17 ± 0.52) and B (1.33 ± 0.52) (P < 0.05), while a lower mean behavioral score was estimated in Group D (3.50 ± 0.50) than in Group C (P < 0.05). There were significant differences among the groups in terms of serum IFN-γ (F = 4.08, P < 0.05), IL-4 (F = 275.90, P < 0.05), IL-5 (F = 96.82, P < 0.05), IL-10 (F = 77.67, P < 0.05), TGF-β (F = 9.98, P < 0.05) and OVA-sIgE levels (F = 44.69, P < 0.05). The serum IFN-γ level was significantly lower in Group C than in groups A, B and C (P < 0.05), and the serum levels of IL-4, IL-5 and OVA-sIgE were significantly higher in Group C than in groups A, B and C (P < 0.05), while the serum IL-10 and TGF-β levels were significantly greater in Group D than in Group C (P < 0.05). Microscopy showed apparent loss of nasal mucosa cilia, increased number and enlargement of goblet cells, interstitial edema and submucous vascular dilation in Group C, while the pathological changes of nasal mucosa were alleviated in Group D relative to Group C.

CONCLUSIONS

E. granulosus HCFP has a protective activity against OVA-induced allergic rhinitis in mice.