Antibacterial Activity of Propolis-Embedded Zeolite Nanocomposites for Implant Application

This study investigates the potential of propolis-embedded zeolite nanocomposites for dental implant application. Propolis-embedded zeolite nanocomposites were fabricated by complexation of propolis and zeolites. Then, they were pelleted with Poly(L-lactide) (PLA)/poly(ε-caprolactone) (PCL) polymer for the fabrication of a dental implant. The chemical properties of propolis were not changed during the fabrication of propolis-embedded zeolite nanocomposites in attenuated total reflection-fourier transform infra-red (ATR FT-IR) spectroscopy measurements. Propolis was continuously released from propolis-embedded zeolite nanocomposites over one month. PLA/PCL pellets containing propolis-embedded zeolite nanocomposites showed longer sustained release behavior compared to propolis-embedded zeolite nanocomposites. Propolis-embedded zeolite nanocomposite powder showed similar antibacterial activity against C. albicans in an agar plate and formed an inhibition zone as well as chlorohexidine (CHX) powder. Eluted propolis solution from PLA/PCL pellets also maintained antibacterial activity as well as CHX solution. Furthermore, eluted propolis solution from PLA/PCL pellets showed significant antibacterial efficacy against C. albicans, S. mutans and S. sobrinus. Dental implants fabricated from PLA/PCl polymer and propolis-embedded zeolite nanocomposites also have antibacterial efficacy and negligible cytotoxicity against normal cells. We suggest that PLA/PCl pellets containing propolis-embedded zeolite nanocomposites are promising candidates for dental implants.     

Ultrasensitive detection of low-ppm H2S gases based on palladium-doped porous silicon sensors

In this study, the sensing properties of palladium-doped porous silicon (Pd/p-Si) substrates for low-ppm level detection of toxic H₂S gas are investigated. A Si substrate with dead-end pores ranging from nano- to macroscale was generated by a combined process of metal-assisted chemical etching (MacE) and electrochemical etching with tuned reaction time, in which nano-Pd catalysts were decorated by E-beam sputtering deposition. The sensing properties of the Pd/p-Si were enhanced as the thickness of the substrate layer increased; along with the resulting variation in surface area, this resulted in superior H₂S sensing performances in the low-ppm range (less than 3 ppm), with a detection limit of 300 ppb (sensitivity 30%) at room temperature. Furthermore, the sensor displayed excellent selectivity toward the hazardous H₂S molecules in comparison with various other reducing gases, including NO₂, CO₂, NH₃, and H₂, showing its potential for application in workplaces or environments affected by other toxic gases. The enhancement in sensing performance was possibly due to the increased dispersion and surface area of Pd nano-catalysts, which led to an increase in chemisorption sites of adsorbate molecules.

In this study, the sensing properties of palladium-doped porous silicon (Pd/p-Si) substrates for low-ppm level detection of toxic H₂S gas are investigated.     

Boiling Histotripsy Ablation of Renal Cell Carcinoma in the Eker Rat Promotes a Systemic Inflammatory Response

Boiling histotripsy (BH) is an experimental focused ultrasound technique that produces non-thermal mechanical ablation. We evaluated the feasibility, short-term histologic effects and the resulting acute inflammatory response to BH ablation of renal cell carcinoma (RCC) in the Eker rat. Genotyped Eker rats were monitored for de novo RCCs with serial ultrasound (US) imaging. When tumors were ≥8 mm, rats underwent ultrasound-guided extracorporeal ablation of the tumor with BH, a pulsed focused US technique that produces non-thermal mechanical ablation of targeted tissues, or a sham US procedure. Treatments targeted approximately 50% of the largest RCC with a margin of normal kidney. BH treated rats were euthanized at 1 (n?=?4) or 48 (n?=?4) h, and sham patients (n?=?4) at 48 h. Circulating plasma cytokine levels were assessed with multiplex assays before and at 0.25, 1, 4, 24 and 48 h following treatment. Kidneys were collected and processed for histologic assessment, immunohistochemistry and intrarenal cytokine concentration measurements. For statistical analysis Student's t-test was used. US-guided BH treatment was successful in all animals, producing hypoechoic regions within the targeted volume consistent with BH treatment effect. Grossly, regions of homogenized tissue were apparent with evidence of focal intra-parenchymal hemorrhage. Histologically, BH produced a sharply demarcated region of homogenized tumor and non-tumor tissue containing acellular debris. BH treatment was associated with significantly increased relative concentration of plasma TNF versus sham treatment (p < 0.05) and transient elevations in high-mobility group box 1 (HMGB1), IL-10 and IL-6 consistent with acute inflammatory response to trauma. Intrarenal cytokine concentrations followed the same trend. At 48 h, enhanced infiltration of CD8⁺ T cells was observed by immunohistochemistry in both the treated and un-treated contralateral RCC/kidneys in BH-treated animals versus sham treatment. BH treatment was well tolerated with transient gross hematuria and a perinephric hematoma developing in one subject each. The study demonstrates the feasibility of BH ablation of de novo RCC and suggests activation of the acute inflammatory cascade following treatment that appears to stimulate CD8+ T cell infiltration of both treated and untreated tumors. Longer duration chronic studies are ongoing to characterize the longevity and robustness of this response.     

Splenic angiosarcoma metastasis to small bowel presented with gastrointestinal bleeding

Primary splenic angiosarcoma is a very rare, aggressive neoplasm with a high metastatic rate and dismal prognosis. This neoplasm usually presents with abdominal pain, splenomegaly, anemia, and thrombocytopenia. Splenic angiosarcoma with bleeding gastrointestinal metastases is extremely rare. The literature contains only two case reports. This study reported a 44-year-old male patient with splenic angiosarcoma with sustained repeated gastrointestinal bleeding due to small bowel metastases. Salvage surgery was performed by splenectomy and resection of the metastatic small bowel tumors. The post-operative course was uneventful; the patient survived with the disease and had no GI bleeding, 7 mo after surgery.     

Exercise‐Induced Ventricular Arrhythmias and Cardiovascular Death

Background: Exercise‐induced ventricular arrhythmias (EIVA) are frequently observed during exercise testing. However, the clinical guidelines do not specify their significance and so we examined this issue in our population. Methods: A retrospective analysis of prospectively collected data was performed on 5754 consecutive male veterans referred for exercise testing at two university‐affiliated Veterans Affairs Medical Centers. Exercise test responses were recorded and cardiovascular mortality was assessed after a mean follow‐up of 6 ± 4 years. EIVA were defined as frequent premature ventricular complexes (PVCs) constituting more than 10% of all ventricular depolarizations during any 30‐second ECG recording, or a run of three or more consecutive PVCs during the exercise test or recovery. Results: EIVA occurred in 426 patients (7.4%). There were 550 (10.6%) cardiovascular deaths during follow‐up. Seventy two (17%) patients with EIVA died of cardiovascular causes, whereas 478 (9.0%) of patients without EIVA died of cardiovascular causes (P < 0.001). Patients with EIVA had a higher prevalence of cardiovascular disease, resting PVCs, resting ST depression, and ischemia during exercise than patients without EIVA. In a Cox hazards model adjusted for age, cardiovascular disease, exercise‐induced ischemia, ECG abnormalities, exercise capacity and risk factors, EIVA was significantly associated with time to cardiovascular death. The combination of both resting PVCs and EIVA was associated with the highest hazard ratio. Conclusions: EIVA are independent predictors of cardiovascular mortality after adjusting for other clinical and exercise test variables; combination with resting PVCs carries the highest risk.     

Successful Treatment of Idiopathic Hypereosinophilic Syndrome with Imatinib Mesylate: A Case Report

Patients with idiopathic hypereosinophilic syndrome (HES) show persistent hypereosinophilia of unknown etiology that is associated with end-organ damage. Different treatments, including the use of corticosteroids and cytotoxics, have been investigated for HES with modest success. We describe a patient with HES who had significant end-organ damage from hypereosinophilia and remained refractory to conventional therapy. Therapy with imatinib mesylate, a selective tyrosine kinase inhibitor that is highly effective in treating patients with BCR-ABL-positive chronic myeloid leukemia, was tried with the patient. The result was impressive, with hematologic remission achieved after 12 days of administration. Our finding concurs with recent reports that imatinib mesylate may be a promising agent in the treatment of some cases of HES.     

Extended surgery for the hepatic artery aneurysm involving duodenum and pancreas--a case report

Hepatic artery aneurysms have been the most frequently reported splanchnic artery aneurysms in the past decade. Due to the complex anatomy and sensitivity of the liver to ischemic injury, a number of therapeutic alternatives exist in repairing aneurysmal hepatic arteries. Excision or obliteration of all hepatic artery aneurysms appears to be the management of choice. However, in managing aneurysms involving the proper hepatic artery and its extrahepatic branches, restoration of normal hepatic blood flow is most crucial. A 49-year-old man was found to have a huge extrahepatic artery aneurysm involving the area from the origin of the common hepatic artery to the distal proper hepatic artery. It ruptured into the duodenal bulb and firmly adhered to the surrounding structures including pancreas and common bile duct. Extended surgery with restoration of normal hepatic flow was performed safely. In cases with huge extrahepatic artery aneurysms, an aggressive approach to restore the hepatic arterial continuity seems appropriate for the prevention of ischemic damage to the liver.     

Systemic lupus erythematosus presented as non-inflammatory necrotizing vasculopathy-induced ischemic glomerulopathy and small vessels-related ischemic cardiomyopathy

The clinical significance of lupus non-inflammatory necrotizing vasculopathy (NINV) is not well established. For example, since lupus renal NINV is usually reported to coexist with proliferative and active glomerulonephritis, it is difficult to demonstrate the role of NINV on renal pathophysiology. Here we report a 16-year-old SLE boy with renal NINV presenting as ischemic glomerulopathy and small vessels-related ischemic heart failure. The renal biopsy demonstrated mild proliferative glomerulonephritis and NINV initially, and one month later repeated renal biopsy showed NINV with ischemic glomerulopathy. These findings established that NINV, but not proliferative glomerulonephritis, was responsive for his acute renal failure (ARF). Another interesting question is about the pathophysiology of his myocardial dysfunction. This patient presented typical angina and congestive heart failure (CHF). Echocardiograms and ventriculography revealed dilatation of four chambers and low ejection fraction. Serial electrocardiograms demonstrated evolutionary ischemic changes. Coronary angiography revealed no abnormality of large vessels. These findings suggested small vascular lesions-induced myocardial ischemia was the underlying mechanism of dilated cardiomyopathy. As myocardial biopsy was not done in our case, we could only speculate, but not prove, that the NINV observed in renal biopsy may also involve in cardiac microvascular beds. Nevertheless, this interesting case emphasized the role of obliterative small vascular lesions in the pathophysiology of ARF and myocardial dysfunction. The patient was treated with high-dose corticosteroid, plasma infusion and hemodialysis. His cardiac function improved gradually, however the renal function did not recover.