Fixation Methods for Implantable Port Chamber: Comparative Study Using Glue, Self-stabilizing Leg and Suture Fixations in Rabbits

Objective

To evaluate the fixation strength and tissue reaction of the glue fixation and self-stabilizing leg fixation methods and to compare the results with those of the conventional tagging suture fixation method.

Materials and Methods

Twelve healthy rabbits were selected and three different methods of implanting the port chamber were employed on the back of each rabbit. A total of thirty six port chambers were implanted with these three different methods, viz. the glue fixation method using tissue adhesive, the self-stabilizing leg method using a self-expandable stabilizing leg, and the suture fixation method. The fixation strength and the gross and histopathologic changes of each fixation method were evaluated at three days, one week, two weeks and four weeks after port implantation.

Results

The glue fixation method showed a good fixation strength, which was similar to that of the tagging suture method (p = 0.3486). Five of the six ports (83%) implanted with the glue fixation method which were examined after two weeks showed cracks on the external surface, but this had no adverse effects on their function. A large amount of granulation tissue reaction was found at the bottom of the chamber (p = 0.0025). The fixation with the self-stabilizing leg showed relatively lower fixation strength (p = 0.0043), but no turning-over of the chamber occurred. The fixation strength improved with time after the first week, and minimal granulation tissue reaction was observed with this method.

Conclusion

The glue fixation method exhibited equal fixation strength compared to the suture fixation, but showed cracking and a large amount of granulation tissue, whereas the fixation with a self-stabilizing leg showed weaker fixation strength.     

Application of a pressure-relieving air compliance chamber in a single-pulsatile extracorporeal life support system: an experimental study

Nonpulsatile blood pumps are mainly used in extracorporeal life support systems. Although pulsating blood flow is known to be physiological, a pulsatile pump is not commonly applied in a circuit with a membrane oxygenator because of damage to the blood cells. The hypothesis that the placement of a pressure-relieving compliance chamber in a circuit might reduce blood cell trauma was tested. An extracorporeal life support circuit was constructed in an acute lung injury model of dogs by oleic acid infusion. The animals were divided into three groups. In group I (n = 6) a nonpulsatile centrifugal pump was used as a control. In group II (n = 4) a single-pulsatile pump was used, and in group III (n = 6) a single-pulsatile pump equipped with a compliance chamber was used. Pump flow was maintained at 1.8-2.0 L/min for 2 h. Hemodynamics and blood gas analyses indicated that the pulsatile groups II and III had better results than the nonpulsatile group I. The plasma-free hemoglobin level, which indicates blood cell trauma, was the lowest in group I and the highest in group II but was significantly decreased in group III. A pressure-relieving compliance chamber could significantly reduce high circuit pressures and blood cell trauma.     

Ureteroscopic lithotripsy under local anesthesia: analysis of the effectiveness and patient tolerability

OBJECTIVES: We tried to evaluate the feasibility and effectiveness of ureteroscopic lithotripsy under local anesthesia. METHODS: We evaluated the results of ureteroscopic lithotripsy under local anesthesia performed on 200 patients (male 91; female 109). We compared the pain perception during local ureteroscopic procedure to that of cystoscopy using a visual analogue pain scale recorded by the patient. RESULTS: The overall success rate was 93% (185/200). The success rates of the upper, mid and lower ureteral calculi were 83% (5/6), 78% (14/18), and 94% (166/176), respectively. The success rate was 94% (166/176) in calculi less than 10 mm, and 86% (30/35) in those more than 10 mm. There were 5 cases (3%) of complications: ureteral injury (1), pyelonephritis (2), and ureteral stricture (2). Although the mean pain scale score was higher in the ureteroscopy group (3.36+/-1.75) than in the cystoscopy group (3.13+/-1.92), the difference between the two groups was not statistically significant (p>0.05). Most of the patients tolerated pain during the procedure and only two patients required general anesthesia. Postoperative pain was also tolerable in most patients and only 8 (4%) patients required additional analgesics after the procedure. CONCLUSION: As the effectiveness and morbidity of ureteroscopic lithotripsy under local anesthesia are comparable to those of many other previous reports and as most of the patients could tolerate the pain of the procedure, we suggest that ureteroscopic lithotripsy can be performed effectively and safely under local anesthesia.     

Novel regimen for the treatment of juvenile myelomonocytic leukemia (JMML)

The effective treatment for juvenile myelomonocytic leukemia (JMML) patients lacking access to stem cell transplantation remains unavailable. Here, we describe a promising result obtained with novel regimen comprised of a combination of chemotherapy and differentiation therapy. Five patients diagnosed as JMML were treated with a standard regimen (cytosine arabinoside (Ara-C) 100mg/m(2) per day continuous infusion (days 0-6), etoposide 100mg/m(2) per day (days 0-4), vincristine 1.5mg/m(2) per d (day 9) and isotretinoin 75-100mg/m(2) per day (days 10-20)). All patients responded to the standard regimen. Three of the five were later treated with salvage a regimen (Ara-C 100mg/m(2) per day continuous infusion (days 0-4), etoposide 100mg/m(2) per day (days 0-4) and Ara-C 15mg/m(2) per day SC (days 6-15)) when immature myeloid cells reappeared in the peripheral blood, the spleen increased or blast crisis occurred. Immature myeloid cells disappeared again after one cycle of salvage regimen in all patients. All patients are alive now with a median follow up duration of 27 months (8-69 months). Although the number of patients enrolled was limited, the standard and salvage regimens were found to be safe and effective alternatives for JMML patients without a matched donor. These regimens also could be used safely before stem cell transplantation.     

Chlropyrifos-methyl shows anti-androgenic activity without estrogenic activity in rats

Chlorpyrifos-methyl (CPM), an organophosphate insecticide, widely used for grain storage and agriculture, has been suspected as endocrine disrupter by a few in vitro studies. This study was performed to investigate the (anti-) estrogenicity and (anti-) androgenicity of CPM in vivo using immature rat uterotrophic assay and rat Hershberger assay. CPM with or without 17beta-estradiol were administered to 20 days old female rats to investigate its (anti-) estrogenic activity. Uterine and vaginal weight, uterine epithelial cell height were not affected by the treatment of CPM (2, 10, 50, 250 mg/kg). CPM 250 mg/kg potentiated relative vagina weight in 17beta-estradiol treated immature female rats without any changing of uterine weight. Relative liver weight was increased with decrease of body weight by CPM 250 mg/kg treatment. Uterine cell proliferation tested with bromodeoxyuridine labeling index was not observed in CPM treated rats. CPM with or without testosterone propionate were administered to castrated rat of 51 days old for 10 days to investigate the (anti-)androgenic activity,. The weight of relative and absolute androgen-dependent accessory sex organs; seminal vesicle with coagulating glands (SV/CG), ventral prostate gland (VP), glans penis (GP), levator ani plus bulbocarvernosus muscle (LABC) and Cowper's gland (CG,) were unchanged by the treatment of CPM alone. While CPM induced the increase of relative adrenal gland weight, CPM 50mg/kg decreased the weights of CV/CG, VP, CG and LABC without change of GP without changing of GP when it was treated with TP. In conclusion, CPM dose not show estrogenic and anti-estrogenic activity in immature female rats, but it represents anti-androgenic activity by inhibition of the TP-stimulated increase of the weight of accessory sex organs.     

AMPA receptor trafficking and synaptic plasticity: major unanswered questions

Dynamic movements of AMPA receptors in and out of the postsynaptic membrane account for, at least in part, the expression of NMDA receptor-dependent changes in synaptic efficacy such as long-term potentiation and long-term depression. Recently some of key molecules and subunit rules involved in AMPA receptor trafficking have been identified. In this update article, we try to highlight what we believe to be the major conceptual problems and unanswered questions in this rapidly moving field of neuroscience.     

Malunion of femoral head fractures treated by partial ostectomy: three case reports

Malunion of femoral head fractures has been rarely reported. We report on three cases of malunion of the femoral head, which were treated by partial ostectomy. All patients were involved in traffic accidents and had a posterior fracture-dislocation of the hip. The types of femoral head fractures were Pipkin type I with inferomedial fracture fragment in all cases. Initially, they were treated by closed reduction and skeletal traction for between 6 and 8 weeks. The patients were then transferred to our hospital; the chief complaint was of limited hip motion. A protruding bony mass limiting the hip motion was resected in all cases. The Smith-Petersen approach was used in all cases. The malunion sites were located distally to the original fracture site in all cases. Full weight bearing was permitted, and a range of motion exercises was started postoperatively. Excellent results were obtained with almost complete restoration of hip motion without pain. In the follow-up radiographs, there were no cases of avascular necrosis.