Reversed vein graft stenosis: early diagnosis and management.

Conscientious surveillance of intrainguinal bypass grafts is mandatory to detect vein graft stenoses, which, if uncorrected, can lead to graft occlusion. It is now widely accepted that noninvasive vascular laboratory studies are the best way to detect these lesions. However, controversy still exists over treatment, specifically whether balloon angioplasty is an acceptable substitute for surgery (patch angioplasty or short jump grafts) in the treatment of these lesions. We have always favored balloon angioplasty as primary treatment and have summarized our experience with treating 72 stenotic reversed femoropopliteal and femorotibial vein grafts, which represent 12% of 521 bypass grafts performed at our institution. Prosthetic and in situ grafts are specifically excluded from this report, as well as occluded grafts, found to have stenotic lesions after lytic therapy. The most common stenotic lesion occurred within 4 cm of the proximal anastomosis (29/72 = 40%). The other sites were near the distal anastomosis (7/72 = 10%), and in the middle of the graft (15/72 = 12%). Eighty-one percent (58/72) of the lesions were treated initially by balloon angioplasty with a 31% recurrence. Twenty-nine percent of the 14 grafts treated surgically by vein patch angioplasty or short jump grafts experienced recurrence. Overall 61% (44/72) of the stenotic grafts were treated by balloon angioplasty alone. The 5-year life-table assisted primary patency after correction of the stenotic lesion was 61%. The patency of the grafts from the time of initial bypass surgery, however, was 80%. Location of the stenosis within the graft was a major determinant of patency. Lesions in the proximal graft, proximal anastomosis, and distal graft taken as a group had significantly better patency than the midgraft and distal anastomotic lesions (5-year patency, 65% vs 48%, p less than 0.001 log rank test). We continue to recommend balloon angioplasty as primary therapy for vein graft stenosis except for those occurring in the midgraft and distal anastomosis. Fortunately, this group accounts for only 36% of lesions seen with reversed veins. Recurrent stenosis after balloon angioplasty should be repaired surgically.     

Synergistic effect of modified pore and heterojunction of MOF-derived α-Fe2O3/ZnO for superior photocatalytic degradation of methylene blue

Mesoporous heterojunction MOF-derived α-Fe₂O₃/ZnO composites were prepared by a simple calcination of α-Fe₂O₃/ZIF-8 as a sacrificial template. The optical properties confirm that coupling of both the modified pore and the n–n heterojunction effectively reduces the possibility of photoinduced charge carrier recombination under irradiation. The mesoporous Fe(25)ZnO with 25% loading of α-Fe₂O₃ exhibited the best performance in MB degradation, up to ∼100% after 150 minutes irradiation, higher than that of pristine ZnO and α-Fe₂O₃. Furthermore, after three cycles reusability, mesoporous Fe(25)ZnO still showed an excellent stability performance of up to 95.42% for degradation of MB. The proposed photocatalytic mechanism of mesoporous Fe(25)ZnO for the degradation of MB corresponds to the n–n heterojunction system. This study provides a valuable reference for preparing mesoporous MOF-derived metal oxides with an n–n heterojunction system to enhance MB photodegradation.

Mesoporous heterojunction MOF-derived α-Fe₂O₃/ZnO composites were prepared by a simple calcination of α-Fe₂O₃/ZIF-8 as a sacrificial template.     

Genomic fingerprints of Staphylococcus aureus of bovine origin by polymerase chain reaction-based DNA fingerprinting.

Staphylococcus aureus (n = 75) isolated from mammary secretions of cows with subclinical and clinical mastitis from several geographic locations in the USA were examined using polymerase chain reaction-based DNA fingerprinting. DNA fingerprints were produced using a synthetic oligonucleotide primer (5''GTAACGCC3'') to produce a distinct spectrum of amplified DNA fragments facilitating a high degree of resolution for differentiating S. aureus strains. PCR-based DNA fingerprinting grouped the 75 S. aureus isolates into 19 distinct profiles. The technique differentiated closely related strains within and between geographic locations. Findings suggest that certain types are found across geographic regions suggesting a common clonal type. Within herd data suggest heterogeneity among subclinical and clinical isolates of S. aureus strains. Compared to existing typing methods, PCR-based DNA fingerprinting is easy to perform and interpret. Use of PCR-based DNA fingerprinting may allow for a more detailed investigation of the epidemiology of S. aureus mastitis in dairy cows.     

Clinical outcomes and risk factors for severe COVID-19 in patients with haematological disorders receiving chemo- or immunotherapy

Haematology patients receiving chemo- or immunotherapy are considered to be at greater risk of COVID-19-related morbidity and mortality. We aimed to identify risk factors for COVID-19 severity and assess outcomes in patients where COVID-19 complicated the treatment of their haematological disorder. A retrospective cohort study was conducted in 55 patients with haematological disorders and COVID-19, including 52 with malignancy, two with bone marrow failure and one immune-mediated thrombotic thrombocytopenic purpura (TTP). COVID-19 diagnosis coincided with a new diagnosis of a haematological malignancy in four patients. Among patients, 82% were on systemic anti-cancer therapy (SACT) at the time of COVID-19 diagnosis. Of hospitalised patients, 37% (19/51) died while all four outpatients recovered. Risk factors for severe disease or mortality were similar to those in other published cohorts. Raised C-reactive protein at diagnosis predicted an aggressive clinical course. The majority of patients recovered from COVID-19, despite receiving recent SACT. This suggests that SACT, where urgent, should be administered despite intercurrent COVID-19 infection, which should be managed according to standard pathways. Delay or modification of therapy should be considered on an individual basis. Long-term follow-up studies in larger patient cohorts are required to assess the efficacy of treatment strategies employed during the pandemic.     

Effect of an educational video on emergency department patient stroke knowledge

The purpose of this study was to explore whether passive watching of a stroke videotape in the Emergency Department waiting room could be an effective method for patient education. The setting was an urban, inner city teaching hospital. After providing informed consent, subjects were randomized into two arms: those watching a 12-min educational video on stroke developed by the American Stroke Association (video group) and those not undergoing an intervention (control group). Both groups were administered a 13-question quiz covering different stroke-related issues, but only the video group received this same test again after the completion of the educational program. Those enrolled were contacted after 1 month to determine knowledge retention via the same test. Immediately after watching the educational program, participants demonstrated improved knowledge of stroke-related questions, with an increase of test scores from 6.7 +/- 2.5 to 9.5 +/- 2.6 (p < 0.01). Even at the 1-month follow-up, the video group had significantly higher test scores than the control group. A stroke educational videotape improves the knowledge of this dangerous disease and may be a valuable and relatively low-cost tool for focused patient education in the Emergency Department waiting room.     

Treatment of carbon tetrachloride and phenobarbital-induced chronic liver failure with intrasplenic hepatocyte transplantation

Hepatocyte transplantation (HTx) has been shown to improve the survival of laboratory animals with experimentally induced acute liver failure and to ameliorate the physiologic abnormalities associated with liver-based metabolic deficiencies. However, the role of HTx in the treatment of liver cirrhosis (LC) has not been adequately studied. In order to address this issue, HTx was performed in rats following induction of stable LC using phenobarbital (PhB) and carbon tetrachloride (CCl4). Intrasplenic transplantation of 50 x 10(6) primary hepatocytes could significantly improve liver functions and prolong the survival of rats with irreversible, decompensated LC.