Semi-interpenetrating networks (semi-IPN's) based on linear poly(phenylene ether)s and crosslinked polystyrene can be prepared by reactive moulding of crosslinkable polymeric mixtures. These materials show thermomechanical properties which strongly depend on both the ratio of the two polymeric matrices and the degree of crosslinking in the polystyrene network. Samples based on a 50/50 weight ratio of poly(2,6-dimethyl-1,4-phenylene oxide)/crosslinked polystyrene show glass transition temperatures (Tg) which are very dependent on the degree of crosslinking. It is therefore possible to obtain materials with desired Tg, ranging from the Tg of the corresponding linear blend to that of poly(2,6-dimethyl-1,4-phenylene oxide) alone. 相似文献
The incidence of invasive fungal infection is increasing especially in the field of transplantation, affecting as many as 50% of bone marrow transplant (BMT) patients with neutropenia and 5-20% of solid-organ transplant (SOT) recipients. Fusarium species are soil saprophytes and plant pathogens. They may cause superficial mycoses or important opportunistic infections in patients with bone marrow suppression and neutropenia, they have been rarely described in solid organ recipients, and up to now there have been no reports of such infection in isolated liver transplanted patients. We describe a case of disseminated Fusarium solani infection with hepatic localization in a liver transplanted patient that resolved with the administration of amphotericin B. Our observation confirms that Fusarium spp. are emerging pathogens that may most frequently affect not only BMT patients and patients with hematological malignancies, but also SOT patients. They may cause both localized and disseminated infection. In conclusion, Fusarium spp. etiology should be considered in the context of infectious diseases following liver transplantation. 相似文献
Objective: Severe atherosclerosis of the ascending aorta and arch frequently causes difficulties during heart operations, hindering surgical manoeuvres and potentially leading to systemic embolism. The aim of our study was to assess the safety and effectiveness of replacing the atherosclerotic ascending aorta in this setting. Methods: Aortic atherosclerosis was characterized by epiaortic ultrasonographic scanning in 90.1% of 1927 consecutive adult patients undergoing cardiac operations, and by computed tomographic chest scanning in selected cases. Thirty-six of the 152 patients requiring major derangements from our standard practice due to aortic atherosclerosis underwent replacement of the ascending aorta and constitute the study group. Replacement of the aorta was extended to the arch in 13 cases (36.1%). It was associated with single or multiple valve surgery in 34 patients (94.4%) and with coronary revascularization in 30 (83.3%). Two patients (5.6%) underwent coronary bypass grafting without valve surgery. A cryoablation procedure was associated in three patients with permanent atrial fibrillation. Deep hypothermic circulatory arrest was employed in 34 patients (94.4%), while proximal aortic disease allowed conventional distal crossclamping in 2 cases. The risk of operative mortality was estimated by the logistic EuroSCORE both with and withholding the variable ‘surgery of the thoracic aorta’. All survivors were followed-up for 1–41 months (16 ± 12). Results: Two patients died in the hospital (5.6%) and two during follow-up, for a cumulative survival of 91.3% and 85.6% at 1 and 3 years, respectively (hospital deaths included). The hospital death rate compared favourably with the expected estimates of 25.5% (p < 0.05) and 10.3% (p = 0.67) obtained by the EuroSCORE full model and without ‘aortic surgery’, respectively. In-hospital adverse neurologic events occurred in six patients (16.7%), including stroke in one patient (2.8%) and neurocognitive disturbances in five (13.9%), although they were all transient and cleared before discharge. Excess bleeding required re-exploration in four patients (11.1%), and one more patient underwent emergency grafting for acute postoperative coronary occlusion. Ten patients (38.5%) were intubated for longer than 24 h. Conclusion: Despite significant perioperative morbidity, replacement of the severely atherosclerotic aorta is worth consideration to avert expectedly higher death and stroke rates. 相似文献
Background Laparoscopic cholecystectomy is now indisputably the gold standard for managing most gallbladder diseases. However, subversion
of the Calot triangle anatomy cannot always be managed by laparoscopy and often requires a laparotomy conversion. This report
discusses our patients treated with our personal technique.
Methods Patients undergoing subtotal cholecystectomy performed by the same surgeon with a personal technique from January 1999 to
December 2007 were considered for the present study. Sex, age, symptoms, co-morbidities, diagnostic modality, time between
hospitalization and surgery, length of postsurgical hospitalization, morbidity and mortality, and follow-up were assessed.
Results Four men and six women, aged 23 to 88 years, were included. Every patient had symptoms of acute cholecystitis. Four patients
had had symptoms for an average of 2.5 days and six for an average of 5.1 h. All patients were studied by ultrasonography,
and seven underwent computed tomography. The operation was performed within 48 h in all patients. The average hospital stay
from surgery to discharge was different for patients who underwent primary open cholecystectomy (10 days, range 5–16 days)
and those having a conversion after a laparoscopic attempt (7.8 days, range 4–16 days). During the postoperative period only
one patient presented a self-limiting biliary leak. No postoperative mortality occurred. At follow-up, any recurrences of
stone in the biliary tract or newly formed pouch were recorded.
Conclusions The results suggest that this new approach can be considered effective in every instance of subversion of the normal anatomy
of Calot’s triangle. 相似文献
Background: Measuring the work of breathing of patients undergoing spontaneous assisted ventilation can be useful to monitor and titrate ventilatory support. The aim of this study was to obtain measurements of the pressure generated by the respiratory muscles (PMUSC) and the derived pressure-time product (PTP; a good indicator of the metabolic work of breathing), performing the rapid interrupter technique with a commercial ventilator.
Methods: A Draeger Evita 4 ventilator (Draeger Medical, Lubeck, Germany) was controlled by a personal computer to rapidly interrupt the airway flow at different times and volumes of the respiratory cycle during pressure-support ventilation. From the airway pressure tracing after the occlusion, the authors estimated the alveolar pressure and PMUSC; the integration of PMUSC values over the inspiratory time yields the measurement of PTP. Esophageal pressure measurements were used as a reference. After a bench study of the valves' performance, the authors performed 11 measurement sequences in eight patients.
Results: The closure times for the inspiratory and expiratory valves were 74 +/- 10 and 61 +/- 13 ms, respectively. The interrupter technique provided a reliable estimate of PMUSC (PMUSC, occl = 1.00 [middle dot] PMUSC, pes + 0.19; r = 0.88; 95% confidence interval for agreement, +5.49/-5.32 cm H2O). PTPoccl tightly correlated with PTPpes (PTPoccl = 0.95 [middle dot] PTPpes + 0.13; r = 0.96; 95% confidence interval, 1.94/-1.61 cm H2O [middle dot] s). 相似文献
BACKGROUND: We have noted an unexpectedly high incidence of prostate cancer in our heart transplant recipients (HTR). METHODS: We conducted a retrospective review of patients after heart transplantation to investigate the prevalence, treatment, and outcome of prostate cancer diagnosed after systematic screening (study group). We compared them with case-matched HTR (control). RESULTS: Among 702 recipients, 15 patients had elevated prostate-specific antigen (PSA) levels. Fourteen cases of prostate cancer were diagnosed and treated. The median time between transplantation and prostate cancer diagnosis was 73 months. No patient was diagnosed in a locally advanced (>T2) or metastatic stage. Eleven patients (78.6%) received curative treatment. During follow-up (median, 44 months), 1 patient died from prostate cancer. The survival rate between the study and control groups did not differ. CONCLUSION: Routine PSA testing is recommended as a screening test for prostate cancer in patients after heart transplantation. We believe this could also result in detection of early stages of prostate cancer, thus allowing curative treatment, and achieving similar survival to other case-matched HTR with no prostate cancer. 相似文献
Embryonic remnants of incomplete septation may complicate occlusiondevice implantation in secundum atrial septal defects (sASD)even if stiff devices such as the Amplatzer Occluder are used. A 35-year-old woman was referred to our center for evaluationof a sASD. 相似文献
Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is mainly observed in patients with multiple myeloma and bone metastasis
from solid tumors receiving iv bisphosphonate therapy. The reported incidence of BRONJ is significantly higher with the iv
preparations zoledronic acid and pamidronate while the risk appears to be minimal for patients receiving oral bisphosphonates.
Currently available published incidence data for BRONJ are based on retrospective studies and estimates of cumulative incidence
range from 0.8 to 12%. The mandible is more commonly affected than the maxilla (2:1 ratio), and 60–70% of cases are preceded
by a dental surgical procedure. The signs and symptoms that may occur before the appearance of clinical evident osteonecrosis
include changes in the health of periodontal tissues, non-healing mucosal ulcers, loose teeth and unexplained soft-tissue
infection. Although the definitive role of bisphosphonates remains to be elucidated, the inhibition of physiologic bone remodeling
and angiogenesis by these potent drugs impairs the regenerative capacity of the bone causing the development of BRONJ. Tooth
extraction as a precipitating event is a common observation. The significant benefits that bisphosphonates offer to patients
clearly surpass the risk of potential side effects; however, any patient for whom prolonged bisphosphonate therapy is indicated,
should be provided with preventive dental care in order to minimize the risk of developing this severe condition. This article
provides an update review of current knowledge about clinical, pathological and management aspects of BRONJ. 相似文献