N-acetylcysteine does not modify nitroglycerin-induced tolerance in canine vascular rings

The mechanism whereby nitroglycerin initiates relaxation in vascular smooth muscle remains unclear. One hypothesis states that nitroglycerin oxidizes critical sulfhydryl groups in smooth muscle to initiate relaxation, and that repeated exposure to nitroglycerin results in tolerance. In the current study, N-acetylcysteine, a sulfhydryl-reducing agent, was used to explore the sulfhydryl hypothesis by assessing whether or not tolerance to nitroglycerin was reversed by N-acetylcysteine in canine dorsal pedal artery rings. Two nitroglycerin dose-response curves were performed (n = 18)--one before (1st dose-response curve, from 10(-9) to 1.1 X 10(-5) M nitroglycerin) and one after (2nd dose-response curve, from 10(-9) to 5 X 10(-7) M nitroglycerin) incubation with 10(-5) M nitroglycerin for 105 min. At 5 X 10(-7) M nitroglycerin there was 50.7 +/- 10.0% relaxation during the first dose-response curve. During the second dose-response curve, tolerance to nitroglycerin was evident, as demonstrated by a 6.8 +/- 4.8% relaxation (p less than 0.001) at 5 X 10(-7) M nitroglycerin. A 10-min treatment with 10(-3) M N-acetylcysteine (n = 10) during the second nitroglycerin dose-response curve was performed after the 5 X 10(-7) M concentration of nitroglycerin; the second dose-response curve was then completed up to 1.1 X 10(-5) M nitroglycerin. The dose of 10(-3) M N-acetylcysteine was chosen since higher concentrations (i.e., 1.3 X 10(-2) and 1.2 X 10(-1) M N-acetylcysteine) produced 20.3 +/- 8.4 and 43.6 +/- 11.6% relaxation in vascular rings (n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)     

How Can We Differentiate Local Recurrence From Heterotopic Ossification After Resection and Implantation of an Oncologic Knee Prosthesis in Patients with a Bone Sarcoma?

BackgroundHeterotopic ossification (HO) is common after total joint arthroplasty and usually does not cause diagnostic problems. However, the occurrence of HO after oncologic prostheses implantation can be troublesome as it may mimic a locally recurrent tumor. Because this distinction could have a profound impact on the surgeon and patient, it is important to distinguish the two entities; to our knowledge, no study has evaluated this after oncologic endoprosthetic reconstruction around the knee after tumor resection.Questions/purposes(1) How common is the occurrence of HO compared with local recurrence (LR) after resection of bone sarcoma and the use of an oncologic knee prosthesis? (2) Are there any factors associated with the development of HO after limb salvage procedures with an endoprosthesis? (3) What features allow the surgeon to differentiate HO from a locally recurrent tumor in this setting?Methods‏Between 2002 and 2018, we performed 409 resections of primary bone tumors followed by reconstructions with oncologic endoprostheses. Of these, 17% (71 of 409) died before 2 years and did not have HO at that time, 2% (8 of 409) were lost to follow-up before 2 years, and another 2% (10 of 409) did not have radiographs available at a minimum of 2 years after surgery (and had not developed HO before then), and so could not be analyzed, leaving 320 patients for analysis in this retrospective study. Forty-two patients were excluded; 2% (5 of 320) for a history of failed allograft reconstruction, 3% (8 of 320) for pathologic fracture at presentation, 2% (6 of 320) for inadequate or complicated biopsy, 1% (2 of 320) for stem fractures, 2% (7 of 320) for stem loosening, and 4% (14 of 320) for extracortical bone bridging, leaving 278 patients for final evaluation. Two observers analyzed AP and lateral radiographs for signs of HO at a mean follow-up of 63 ± 33 months after surgery. We defined HO as extraskeletal bone formation in soft tissues. The primary study endpoint was survivorship free from HO, as ascertained by a competing-risks estimator. To identify factors associated with HO appearance, the demographic, radiographic, clinical, pathologic, and surgical characteristics were compared between patients with HO and those who had no lesion. Characteristic features were also compared between patients with HO and those with LR to help their differentiation. Univariate analysis was used for all statistical evaluations.ResultsHO developed in 8% (21 of 278) of patients in whom oncologic knee prosthesis was implanted. LR developed in 10% (28 of 278) of the patients. According to survivorship estimates, the HO-free survival rate was not different from the LR-free survival rate at 2 years after oncologic knee reconstruction (76 ± 5% [95% CI 63 to 87] versus 74 ± 5% [95% CI 62 to 88]; p = 0.19). History of infection was more common in patients with HO than in patients with no lesion (19% [4 of 21] versus 5% [12 of 229], Odds ratio [OR] 6 [95% CI 2 to 17]; p < 0.001). The male sex was more common in the HO group as well (76% [16 of 21] versus 55% [128 of 229], OR 2 [95% CI 1 to 5]; p = 0.03). The Modular Universal Tumor and Revision System prosthesis was more frequently used in patients with HO (67% [14 of 21]) compared to those with no lesions (40% [92 of 229]; OR 2 [95% CI 1 to 5]; p = 0.02).‏ The lesion border in radiographs was ill-defined in 19% (4 of 21) of patients with HO and 100% (28 of 28) of patients with LR (OR 8 [95% CI 3 to 20]; p < 0.001). The median time to the appearance of HO was shorter than the time to LR (8 months [3 to 13] versus 16 months [11 to 21], [95% CI 10 to 13]; p < 0.001). Pain at presentation was more frequent in patients with LR than in those with HO (86% [24 of 28] versus 14% [3 of 21], OR 36 [95% CI 7 to 181]; p < 0.001).ConclusionHO may occur after the use of oncologic knee prostheses for reconstruction after tumor resection. In most patients, HO could be differentiated from local recurrence through identifying a well-defined border on radiographs. Otherwise, factors such as an earlier time of presentation and absence of pain could suggest an HO, rather than an LR.Level of EvidenceLevel III, therapeutic study.     

Impact of IFN‐β1a in treatment of a COVID‐19 patient with beta thalassemia and diabetes mellitus: A case report

Patients with chronic diseases are severely affected by acute coronavirus syndrome. In this regard, patients with beta thalassemia intermedia and diabetes mellitus (DM) are also at high risk for coronavirus‐induced respiratory failure. The present study aimed to report a case with COVID‐19 with a history of chronic diseases, beta thalassemia intermedia, and DM. A 25‐year‐old man visited with complaints of severe shortness of breath, fever, cough without sputum, and tachypnea and admitted to the Intensive Care Unit. The patient had a history of DM, beta thalassemia intermedia, and pervious history of the splenectomy. In peripheral complete blood count (CBC diff), the number of white blood cell count was 41,100 of which 38.6% were lymphocytes. We measured the normal platelet count, hemoglobin level (9.4), and red blood cell count (3.56). ESR was 97, CRP = pos+++ and PCR was positive. The high‐resolution lung CT indicated ground glass opacities in peripheral areas. The patient underwent 13 days of oxygen therapy with reservoir bag‐mask, non‐invasive ventilation, nasal oxygen, and pharmacological treatment with IFN‐β1a and meropenem, and finally discharged with an improvement of the clinical condition. Timely initiation of treatment is very important and significant for patients with beta thalassemia intermedia with COVID‐19, especially despite the underlying disease of DM. According to the present report, the use of IFN‐β1a was effective as a treatment option for COVID‐19.     

Comparison of silver nylon wound dressing and silver sulfadiazine in partial burn wound therapy

The study aims to perform a comparative assessment of two types of burn wound treatment. To do the assessment, patients with partial thickness burn wounds with total body surface area <40% were simple randomised to treat with nanocrystalline silver nylon wound dressing or silver sulfadiazine cream. Efficacy of treatment, use of analgesics, number of wound dressing change, wound infection and final hospitalisation cost were evaluated. The study showed silver nylon wound dressing significantly reduced length of hospital stay, analgesic use, wound infection and inflammation compared with silver sulfadiazine.