A case report: new-onset nummular headache after stenting of the middle cerebral artery.

BACKGROUND: Nummular headache (NH) is categorized as a primary headache in the International Classification of Headache Disorders, Third edition (ICHD-3) diagnostic criteria, but there are secondary etiologies as well. We present a case of secondary NH that associated with vascular lesion. CASE PRESENTATION: We report on a 40-year-old man with a medical history of symptomatic intracranial arterial stenosis who developed a headache after percutaneous transluminal angioplasty and stenting because of Intracranial atherosclerotic stenosis(ICAS). This new-onset headache was a pinprick headache confined to the parietal part of the head and 5 cm in size. This headache most closely resembled the phenotype of a NH. And other causes of secondary headache were excluded. Thus, the diagnosis of NH was highly speculated. This patient represents a rare headache phenomenon after intracranial arterial stent placement. CONCLUSION: This is the first report of NH after stent placement treatment in a patient with ICAS.

Heterologous expression of oxytetracycline biosynthetic gene cluster in Streptomyces venezuelae WVR2006 to improve production level and to alter fermentation process.

Heterologous expression is an important strategy to activate biosynthetic gene clusters of secondary metabolites. Here, it is employed to activate and manipulate the oxytetracycline (OTC) gene cluster and to alter OTC fermentation process. To achieve these goals, a fast-growing heterologous host Streptomyces venezuelae WVR2006 was rationally selected among several potential hosts. It shows rapid and dispersed growth and intrinsic high resistance to OTC. By manipulating the expression of two cluster-situated regulators (CSR) OtcR and OtrR and precursor supply, the OTC production level was significantly increased in this heterologous host from 75 to 431 mg/l only in 48 h, a level comparable to the native producer Streptomyces rimosus M4018 in 8 days. This work shows that S. venezuelae WVR2006 is a promising chassis for the production of secondary metabolites, and the engineered heterologous OTC producer has the potential to completely alter the fermentation process of OTC production.

Identification of a cluster-situated activator of oxytetracycline biosynthesis and manipulation of its expression for improved oxytetracycline production in Streptomyces rimosus.

BACKGROUND: Oxytetracycline (OTC) is a broad-spectrum antibiotic commercially produced by Streptomyces rimosus. Despite its importance, little is known about the regulation of OTC biosynthesis, which hampered any effort to improve OTC production via engineering regulatory genes. RESULTS: A gene encoding a Streptomyces antibiotic regulatory protein (SARP) was discovered immediately adjacent to the otrB gene of oxy cluster in S. rimosus and designated otcR. Deletion and complementation of otcR abolished or restored OTC production, respectively, indicating that otcR encodes an essential activator of OTC biosynthesis. Then, the predicted consensus SARP-binding sequences were extracted from the promoter regions of oxy cluster. Transcriptional analysis in a heterologous GFP reporter system demonstrated that OtcR directly activated the transcription of five oxy promoters in E. coli, further mutational analysis of a SARP-binding sequence of oxyI promoter proved that OtcR directly interacted with the consensus repeats. Therefore, otcR was chosen as an engineering target, OTC production was significantly increased by overexpression of otcR as tandem copies each under the control of strong SF14 promoter. CONCLUSIONS: A SARP activator, OtcR, was identified in oxy cluster of S. rimosus; it was shown to directly activate five promoters from oxy cluster. Overexpression of otcR at an appropriate level dramatically increased OTC production by 6.49 times compared to the parental strain, thus demonstrating the great potential of manipulating OtcR to improve the yield of OTC production.

Mirror Image of Spontaneous Intracranial Hemorrhage.

In this paper, we reported the first case of mirrored spontaneous intracranial hemorrhage with almost identical hematoma morphological characteristics. This patient's first symptom was loss of consciousness, without any local neurological symptoms. This clinical presentation fits well with the atypical computed tomography (CT) image showing bilateral hematomas, and indicates that the distribution of hypertensive vascular damage may be symmetric and that the degree of the bilateral lesions may be similar.

Blood pressure management after endovascular thrombectomy: Insights of recent randomized controlled trials.

BACKGROUND: The ideal blood pressure (BP) target in patients who undergo endovascular thrombectomy (EVT) with successful reperfusion is uncertain. Observational studies show that elevated BP during this period is associated with a higher risk of intracranial hemorrhage (ICH) and worse clinical outcomes. Several randomized controlled trials (RCTs) have explored whether intensive BP lowering improves clinical outcomes in these patients. AIMS: This review aims to summarize the recent RCTs that compare intensive and conventional BP management strategies following EVT and discuss the innovative directions to improve. RESULT: The recently published RCTs failed to demonstrate the benefit of intensive BP control on the functional outcome and decreasing the risk of ICH. The complex mechanism in cerebral blood flow regulation and the inappropriate BP range chosen in RCTs may be the reasons behind the inconsistent results between observational studies and RCTs. Individualized BP management, reducing BP variability, and multi-stage BP management should be paid more attention in future exploration. CONCLUSION: Intensive BP target did not improve clinical outcomes after successful EVT as compared with a conventional BP target. Further research is required to identify the optimal BP management strategy after reperfusion.

Analytical Model for the Channel Maximum Temperature in Ga2O3 MOSFETs.

In this work, we proposed an accurate analytical model for the estimation of the channel maximum temperature of Ga2O3 MOSFETs with native or high-thermal-conductivity substrates. The thermal conductivity of Ga2O3 is anisotropic and decreases significantly with increasing temperature, which both are important for the thermal behavior of Ga2O3 MOSFETs and thus considered in the model. Numerical simulations are performed via COMSOL Multiphysics to investigate the dependence of channel maximum temperature on power density by varying device geometric parameters and ambient temperature, which shows good agreements with analytical model, providing the validity of this model. The new model is instructive in effective thermal management of Ga2O3 MOSFETs.

Improvement of oxytetracycline production mediated via cooperation of resistance genes in Streptomyces rimosus.

Increasing the self-resistance levels of Streptomyces is an effective strategy to improve the production of antibiotics. To increase the oxytetracycline (OTC) production in Streptomyces rimosus, we investigated the cooperative effect of three co-overexpressing OTC resistance genes: one gene encodes a ribosomal protection protein (otrA) and the other two express efflux proteins (otrB and otrC). Results indicated that combinational overexpression of otrA, otrB, and otrC (MKABC) exerted a synergetic effect. OTC production increased by 179% in the recombinant strain compared with that of the wild-type strain M4018. The resistance level to OTC was increased by approximately two-fold relative to the parental strain, thereby indicating that applying the cooperative effect of self-resistance genes is useful to improve OTC production. Furthermore, the previously identified cluster-situated activator OtcR was overexpressed in MKABC in constructing the recombinant strain MKRABC; such strain can produce OTC of approximately 7.49 g L-1, which represents an increase of 19% in comparison with that of the OtcR-overexpressing strain alone. Our work showed that the cooperative overexpression of self-resistance genes is a promising strategy to enhance the antibiotics production in Streptomyces.