Comparative Fibrinolytic Properties of Staphylokinase and Streptokinase in Animal Models of Venous Thrombosis

The thrombolytic and pharmacokinetic properties of staphylokinase were compared with those of streptokinase in hamsters with a pulmonary embolus produced from human plasma or from hamster plasma, and in rabbits with a jugular vein blood clot produced from rabbit blood. In both models, a continuous intravenous infusion of staphylokinase and streptokinase over 60 min in hamsters or over 4 h in rabbits, induced dose-dependent progressive clot lysis in the absence of significant systemic activation of the fibrinolytic system. The results of thrombolytic potency (clot lysis at 30 min after the end of the infusion, in percent, versus dose administered, in mg/kg) were fitted with an exponentially transformed sigmoidal function and the maximal percent clot lysis (c), the maximal rate of lysis (z = ¼ac · e b ) and the dose at which the maximal rate of lysis is achieved (b) were determined. In hamsters with a pulmonary embolus produced from human plasma, streptokinase had a somewhat higher thrombolytic potency than staphylokinase, as revealed by a higher z value (2,100 ± 1,100% lysis per mg/kg streptokinase administered versus 1,100 ± 330% lysis per mg/kg for staphylokinase). In hamsters with a pulmonary embolus produced from hamster plasma, staphylokinase had a somewhat higher thrombolytic potency than streptokinase (z = 1,600 ± 440 versus 1,200 ± 370% lysis per mg/kg). Staphylokinase had a higher thrombolytic potency than streptokinase in rabbits, as revealed by a higher z-value (950 ± 350% lysis per mg/kg staphylokinase administered versus 330 ± 39% lysis per mg/kg for streptokinase) and a lower b-value (0.035 ± 0.010 mg/kg staphylokinase versus 0.091 ± 0.008 mg/kg for streptokinase). The plasma clearance following bolus injection of staphylokinase or streptokinase in hamsters or rabbits was comparably rapid (1.1 to 1.4 ml/min in hamsters and 14 to 15 ml/min in rabbits) as a result of a short initial half-life (1.8 to 1.9 min in hamsters and 1.7 to 2.0 min in rabbits). These results in two quantitative rodent models of thrombolysis suggest that staphylokinase is a potent thrombolytic agent with an in vivo thrombolytic potency that is comparable to that of streptokinase. Further investigation of the thrombolytic potential of staphylokinase seems to be warranted.

Characterization and Targeting of the Murine α2-Antiplasmin Gene

α2-Antiplasmin (α2-AP) is the main physiological plasmin inhibitor in mammalian plasma. As a first step toward the generation of α2-AP deficient mice, the murine α2-AP 1 gene was characterized and a targeting vector for homologous recombination in embryonic stem (ES) cells constructed. Alignment of nucleotide sequences obtained from genomic subclones allowed location of exons 2 through 10 of the α2-AP 1gene, but failed to identify the 5’ boundary of exon 1. Compared to the human gene, exons 2 through 9 in the murine gene have identical size and intron-exon boundaries obeying the GT/AG rule. The 5’ boundary of exon 10 is identical in both genes while the 3’ non-coding region is 64 bp longer in the human gene. Introns 2,3,6 and 8 have similar sizes in the mouse and human genes; intron 1 is 6-fold smaller, introns 5, 7 and 9 are 2- to 3-fold smaller, whereas intron 4 is about 2-fold larger in the mouse gene. Compared to the human 5’ flanking sequence, an insertion of a simple repeat region with sequence (TGG)n has occurred. The open reading frame of the mouse α2-AP gene encodes a 491-amino acid protein comprising the experimentally determined NH2-terminus of the mature protein Val-Asp-Leu-Pro-Gly-.

A targeting vector, ppPNT.α2-AP, was constructed by introducing a homologous sequence of 8.3 kb in total in the parental pPNT vector. In pPNT.α2-AP, the neomycin resistance expression cassette replaces a 7 kb genomic fragment comprising exon 2 through part of exon 10 (including the stop codon), which represents the entire sequence encoding the mature protein, including the fibrin-binding domain, the reactive site peptide bond and the plasmin(ogen)-binding region. Electroporation of 129R1 embryonic stem (ES) cells with the linearized vector pPNT.α2-AP yielded three targeted clones with correct homologous recombination at the 5’- and 3’-ends, as confirmed by Southern blot analysis of purified genomic DNA with appropriate restriction enzymes and probes. These targeted clones will be used to generate α2-AP deficient mice.

Procoagulant Properties of Intravenous Staphylokinase Versus Tissue-Type Plasminogen Activator

The fibrin-specificity and procoagulant effects of recombinant staphylokinase (Sak42D) were compared with those of recombinant tissue-type plasminogen activator (rt-PA) in patients with acute myocardial infarction. Plasma samples were obtained at baseline and at 25 and 90 min, from 24 patients who were randomly assigned to a double bolus (15 mg each, 30 min apart) administration of Sak42D or to accelerated weight-adjusted rt-PA (maximum of 100 mg over 90 min). Baseline levels of fibrinopeptide A (FPA), prothrombin fragment 1+2 and thrombin-antithrombin III complex (TAT) were comparable in the Sak42D and rt-PA groups (p ≥ 0.6). In patients treated with Sak42D, plasma levels of FPA, prothrombin fragment 1+2 and TAT did not markedly increase during treatment (p = 0.06, p = 0.4 and p = 0.03, respectively). In contrast, during administration of rt-PA the levels of FPA, prothrombin fragment 1+2 and TAT increased significantly over baseline (p = 0.003, p < 0.0001 and p = 0.001, respectively). As a result, the levels of all three procoagulant parameters were significantly lower during treatment with Sak42D as compared to rt-PA. Thus, FPA levels in the Sak42D group (median values) were 40 ng/ml at 25 min and 11 ng/ml at 90 min, as compared to 88 ng/ml and 50 ng/ml in the rt-PA group (p = 0.0007 and p = 0.009, respectively). Prothrombin fragment 1+2 levels in the Sak42D group were 1.3 nM at 25 min and 1.2 nM at 20 min, as compared to 11 nM and 5.3 nM in the rt-PA group (both p < 0.0001). TAT levels were 4.7 ng/ml at 25 min and 6.2 ng/ml at 90 min in the Sak42D group, with corresponding values of 16 ng/ml and 9.6 ng/ml in the rt-PA group (p = 0.02 and p = 0.03, respectively).

In the patients treated with Sak42D, no significant systemic fibrinolytic activation was observed, as revealed by unaltered levels of clotta-ble fibrinogen, plasminogen and a2-antiplasmin up to 90 min after the start of therapy. In contrast, the corresponding residual levels at 90 min in patients treated with rt-PA decreased to (mean ± SEM; n = 12) 62 ± 6%, 45 ± 5% and 52 ± 10%, respectively (all p < 0.01 versus the Sak42D group)

These data confirm the high degree of fibrin-specificity of Sak42D and demonstrate that this is associated with significantly less generation of procoagulant activity in plasma after intravenous administration in patients with acute myocardial infarction

Thoracic aortic aneurysm is an independent factor associated with diffuse idiopathic skeletal hyperostosis

Aims

Although we often encounter patients with an aortic aneurysm who also have diffuse idiopathic skeletal hyperostosis (DISH), there are no reports to date of an association between these two conditions and the pathogenesis of DISH remains unknown. This study therefore evaluated the prevalence of DISH in patients with a thoracic aortic aneurysm (AA).

Patients and Methods

The medical records of 298 patients who underwent CT scans for a diagnosis of an AA or following high-energy trauma were retrospectively examined. A total of 204 patients underwent surgery for an AA and 94 had a high-energy injury and formed the non-AA group. The prevalence of DISH was assessed on CT scans of the chest and abdomen and the relationship between DISH and AA by comparison between the AA and non-AA groups.

Results

The prevalence of DISH in the AA group (114/204; 55.9%) was higher than that in the non-AA group (31/94; 33.0%). On multivariate analysis, the factors of AA, male gender, and ageing were independent predictors of the existence of DISH, with odds ratios of 2.9, 1.9, and 1.03, respectively.

Conclusion

This study revealed that the prevalence of DISH is higher in patients with an AA than in those without an AA, and that the presence of an AA significantly influenced the prevalence of DISH. Cite this article: Bone Joint J 2018;100-B:617-21.

Evaluation of the safety of ramucirumab in Japanese patients with advanced gastric cancer

As a result of the RAINBOW trial, ramucirumab plus paclitaxel was established as a second-line treatment of advanced gastric cancer. Regarding the safety of ramucirumab plus paclitaxel in the Japanese, a subgroup analysis of the RAINBOW trial was conducted. The incidence of neutropenia was higher in Japanese patients. However, information is lacking concerning the safety of ramucirumab after marketing in Japanese patients. Therefore, the aim of this study was to evaluate the safety of ramucirumab in Japanese patients with advanced gastric cancer. The inclusion criteria were patients diagnosed with advanced gastric cancer who had commenced treatment with ramucirumab plus paclitaxel or paclitaxel only at Ogaki Municipal Hospital (Gifu, Japan) between January 2015 and December 2016. There were 26 patients in the ramucirumab plus paclitaxel group and 22 patients in the paclitaxel only group. Treatment-related adverse events were documented in 100.0% of the patients in the ramucirumab plus paclitaxel group (Grade 3-4, 73.1%) and 90.9 % of the patients in the paclitaxel only group (Grade 3-4, 45.5 %). The most frequently observed adverse event in both treatment groups was anemia. The second common adverse event was neutropenia. The incidence of neutropenia of Grade ≥3 was significantly higher in the ramucirumab plus paclitaxel group than in the paclitaxel only group. In conclusion, the incidence of neutropenia is high. However, we believe that ramucirumab plus paclitaxel can be safely administered.

Ultrasound-Guided Fine-Needle Aspiration Biopsy for Breast Tumors: Needle Guide versus Freehand Technique

Background

We retrospectively studied whether a needle guide is necessary when performing ultrasound-guided fine-needle aspiration biopsy (US-FNAB) in patients with breast tumors.

Methods

A total of 47 patients (50 lesions) with breast tumors underwent US-FNAB with a needle guide and 127 patients (143 lesions) underwent the procedure without a needle guide (freehand biopsy). The diagnoses obtained by US-FNAB were compared with the surgical findings.

Results

The sensitivity of freehand biopsy for tumors <3 cm in diameter was significantly higher than that of the needle guide technique.

Conclusions

We recommend performing US-FNAB without a needle guide (freehand biopsy) in order to maximize the correct preoperative diagnosis rate, especially in patients with tumors <3 cm in diameter.

Thyroid Cancer in Uremic Patients

Background

The combination of thyroid cancer and secondary uremic hyperparathyroidism has thus far been reported in only 25 cases.

Methods

Here we report our experience of 19 patients with secondary hyperparathyroidism who underwent parathyroidectomy.

Results

Thyroid nodules were present in five patients (26.3%), including one with a benign nodule and four with papillary thyroid cancer (21.1%).

Conclusion

Our experience suggests that, in order to make a correct diagnosis, clinicians should consider the possibility of thyroid cancer in uremic patients with secondary hyperparathyroidism.

Accessory Breast Cancer: A Case Report and Review of the Japanese Literature

The case of a 31-year-old woman with accessory breast cancer in the left axilla is described. She had noticed a swelling in the left axilla during her three pregnancies. The preoperative diagnosis of accessory breast cancer was made on the basis of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) and clinical history. She was treated by wide local resection and regional lymph node dissection. Although cancer originating from accessory breast tissue has been reported very rarely, knowledge of this disorder may facilitate the correct diagnosis of axillary tumors. US-FNAB is a useful and simple technique for the tissue diagnosis of axillary tumors.

First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph

The masses of ^{246}Es, ^{251}Fm, and the transfermium nuclei ^{249-252}Md and ^{254}No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N=152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of ^{246}Es and ^{249,250,252}Md were measured for the first time. Using the masses of ^{249,250}Md as anchor points for α decay chains, the masses of heavier nuclei, up to ^{261}Bh and ^{266}Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ_{2n} derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N=152 neutron shell closure for Md and Lr.

Key factors for school health policy implementation in Thailand

Thailand formulated a National School Health Policy (NSHP) in 1998, and it has been widely implemented but has not been evaluated. This case study aimed to identify factors that have influenced the implementation of NSHP in Thailand. For this purpose, we conducted a document review and key informant interviews. We selected key interviewees, from NSHP implementers at national, provincial and school levels in four geographical areas. We adopted a content analysis method, using a framework of 12 influential components of successful policy implementation and triangular policy framework. This study showed that NSHP was well-disseminated and implemented at whole country. We identified seven positive factors influencing NSHP implementation, namely matching with ongoing educational strategy, competition and encouragement by an awarding system, sustainable human capacity building at school level, participation of multiple stakeholders, sufficient understanding and acceptance of school health concepts, sharing information and collaboration among schools in the same clusters and functional fund raising activities. In addition, we identified three negative factors, namely lack of institutional sustainability, vague role of provincial officers and diverse health problems among Thai children. The government should clarify the role of provincial level and set up institutionalized capacity-building system as measures to strengthen monitoring and evaluation activities.

High rate capability by sulfur-doping into LiFePO4 matrix

Enhanced electrochemical performance of LiFePO₄ for Li-ion batteries has been anticipated by anion doping at the O-site rather than cation doping at the Fe-site. We report on the electrochemical performance of S-doped LiFePO₄ nanoparticles synthesized by a solvothermal method using thioacetamide as a sulfur source. S-doping into the LiFePO₄ matrix expands the lattice due to the larger ionic radius of S²⁻ than that of O²⁻. The lattice parameters a and b increase by around 0.2% with sulfur content, while that of c remains almost unchanged with only 0.03% increase. The S-doping also contributes to the suppression of antisite defects (Fe occupying Li sites), which facilitates the easy migration of Li in the diffusion channels without blockage. Owing to these effects of S-doping, the S-doped LiFePO₄ nanoparticles show enhanced electrochemical properties with a high discharge capacity of ∼113 mA h g⁻¹ even at a high rate of 10C.

S-doped LiFePO₄ nanoparticles with improved electrochemical properties have been synthesized by a single step solvothermal method.