Injection And Infusion Technology Disruption For Use In MRI.

INTRODUCTION: Contrast media injections, infusions, or experiments that require a constant volume flow close to or within a very high magnetic field like in magnetic resonance imaging (MRI) require a liquid reservoir and a power unit to deliver the fluid. However, most power units are driven by motors that are either not MRI-compatible or require external connections that restrict mobility and usage. In this paper, the development of a highly portable, lightweight, and MRI-compatible pump system is explained. METHODS: The energy required to deliver the flow is generated using a pressurized bottle concept. The valve inside the bottle is opened to create a flow which should be maintained constant. In order to find the optimal flow resistance for a constant flow rate, we created multiple setups with different flow resistance. RESULTS: We measured the flow rates for different flow resistances by attaching a restring valve to the bottle. The results clearly show that high flow resistance results in lower and more constant flow rate. DISCUSSION: The optimal flow rate achieved using our current setup was significantly constant but not ideal. Consequently, such a pump system can be used in many medical applications like MRI-compatible contrast agent injectors.

Irradiation at Different Fetal Stages Results in Different Translocation Frequencies in Adult Mouse Thyroid Cells.

While it is generally believed that fetuses are at high risk of developing cancers, including leukemia, after low doses of radiation, it has been reported that atomic bomb survivors exposed in utero did not show a dose response for translocations in blood T lymphocytes when they were examined at approximately 40 years of age. Subsequent mouse studies confirmed that animals irradiated during the fetal stage did not show evidence of radiation effects in lymphocytes and bone marrow cells when they were examined after reaching adulthood. However, in a study of rat mammary epithelial cells, radiation effects were clearly observed after fetal irradiation. These results indicate that the fate of chromosome aberrations induced in a fetus could vary among different tissues. Here we report on translocation frequencies in mouse thyroid cells, which were irradiated at different stages of fetal development. Cytogenetic examination was conducted using fluorescence n situ hybridization (FISH) painting of chromosomes 1 and 3. Adult mice, 2 Gy X-ray irradiated at 15.5-day-old fetuses (E15.5), showed a higher translocation frequency (30/1,155 or 25.3 × 10-3) than nonirradiated adult controls (0/1,007 or 0.1 × 10-3), and was near that experienced by irradiated mothers and non-pregnant adult females (43/1,244 or 33.7 × 10-3). These results are consistent with those seen in rat mammary cells. However, when fetuses were irradiated at an earlier stage of development (E6.5) before thyroid organogenesis, the resulting observed translocation frequency was much lower (3/502 or 5.8 × 10-3) than that in E15.5 mice. These results suggest that after fetal irradiation, tissue stem cells record radiation effects primarily when the exposure occurs in cells that have been integrated into tissue. Embryonic stem cells that have been damaged prior to integration into the niche may undergo negative selection due to apoptosis, mitotic death or stem cell-niche cell interactions. The implications of these results in interpreting cancer risks after fetal irradiation are also discussed.

Pulmonary valve replacement with a porcine aortic heterograft.

Pulmonary valve replacement is an uncommon surgical procedure, yet lifesaving when performed under the appropriate circumstances. The patient reported on here had the classic indications for valve replacement: increased pulmonary vascular resistance and associated pulmonary valve incompetence following repair of a congenital heart defect resulting in right heart failure and secondary tricuspid insufficiency. A review of the literature provides the basis for the decision to replace the pulmonary valve with a glutaraldehyde-preserved porcine heterograft.

Free-water clearance and the early recognition of acute renal insufficiency after cardiopulmonary bypass.

The predictive value of free-water clearance measurements for the early recognition of acute renal insufficiency was evaluated in 59 patients immediately following cardiopulmonary bypass. Blood urea nitrogen and serum creatinine measurements were taken before and after operation. Intraoperatively, immediately after completion of bypass, urine and serum samples were obtained for osmolality. Duration of bypass, urine output, degree of hemolysis, and quality of perfusion were recorded. Fifty-four patients developed no signs of renal insufficiency following bypass, and all had free-water clearance values equal to or less than -20 ml per hour. Five patients who had free-water clearance values equal to greater than -8 ml per hour developed manifestations of an acute renal insufficiency state. There were no false-negative or false-positive determinations. Consequently, free-water clearance measurements appear to be a reliable indicator of those patients who will develop renal insufficiency following cardiopulmonary bypass. Early recognition provides an opportunity immediately after operation for initiating treatment consisting of administration of diuretics, potassium restriction, and oliguric fluid regimens.

Cinoxacin for treatment and prevention of recurrent urinary tract infection.

Cinoxacin, an orally administered synthetic antimicrobial agent, is highly effective in the treatment of urinary tract caused by most urinary tract pathogens. Its high prolonged urinary concentration, low incidence of adverse reactions, low fecal concentration, infrequent induction of resistant bacterial strains, and broad antimicrobial spectrum are valuable attributes. Its efficacy for prolonged low-dose preventive therapy of frequently recurring infections adds to this new drug's importance.

Cinoxacin: new antimicrobial agent for urinary tract infections.

One hundred forty-six patients with recurrent urinary tract infections were treated with 500 mg. of cinoxacin twice daily for seven to fourteen days. Satisfactory clinical response occurred in 94 per cent. Of the 100 patients with significant pretherapy bacteriuria (greater than or equal to 10(4) organisms/ml. of urine), 65 had complicated infections. Approximately the same per cent of patients with (90 per cent) as without (94 per cent) complicating conditions had a satisfactory clinical response to treatment. The pathogen was eliminated in a higher percentage of patients without underlying disease (90 versus 80 per cent), and infections recurred less frequently in this group (3 versus 14 per cent). Emergence of resistance by initially susceptible organisms during the course of therapy occurred in 4 of 76 patients (5 per cent). A satisfactory clinical response occurred in all 46 patients with an initial colony count of less than 10(4) organisms/ml. urine. Only 1 patient in this group was a bacteriologic failure. Adverse effects of a relatively wild nature were seen in 4 of 146 patients (2.7 per cent). Successful eradication of 12 of 23 urinary infections in patients whose pathogens were resistant to the 30-microgram. cinoxacin disk suggests that the 100-microgram. disk may be more realistic for determining bacterial susceptibility by the disk diffusion method in view of the very high urinary concentration of the drug.

Vesical exstrophy with epispadias. Twenty-year follow-up.

A case we believe to be the longest with successful anatomic closure of exstrophy and epispadias witholt reflux or incontinence is reported. The persistence of the squamous metaplasia in the bladder despite twenty years of "turn-in" is noteworthy. The original method of closure reveals no "secret" to account for the success. The method of repair of traumatic rupture is presented.

Effect of preoperative antibiotic therapy on bacterial prostatitis after transurethral prostatectomy.

Transurethral prostatectomy was performed on 237 patients who required no preoperative antimicrobial therapy and on 182 patients with symptoms of urinary tract infection who received preoperative antimicrobial therapy. At operation all patients were asymptomatic. Data are presented on the incidence of infected prostates, bacteriuria at operation, and postoperative morbidity for the two groups. The findings refute the concept that the chronically infected prostate is resistant to antimicrobial therapy. Transurethral prostatectomy in an infected field was found to increase morbidity. The data suggest that an appropriate preoperative antimicrobial regimen be administered to patients undergoing transurethral prostatectomy with asymptomatic bacteriuria.

Antiepileptic effect of antiepilepsirine in pentylenetetrazol and amygdala kindled rats.

Antiepilepsirine (AES) is a new antiepileptic drug developed in China. Anticonvulsant effects of AES were studied in both pentylenetetrazol (PTZ, n = 20) and amygdala kindled (n = 10) rats. AES was given once per day by oral gavage for 4 weeks. On days 7, 14, 21 and 28, all rats were tested 2 h after daily AES administration: PTZ and amygdala kindled rats were given a PTZ injection (30 mg/kg, i.p.) or amygdala stimulation (400 microA, 1 s), respectively. Behavior was observed, and seizures were graded. AES (300 or 500 mg/kg) produced sustained, dose dependent, protective effects against PTZ induced seizures in PTZ kindled rats, while AES (500 mg/kg) had no effects in amygdala kindled rats.

Comparing outcomes of routine care for depression: the dilemma of case-mix adjustment.

The purpose of this study was to formulate and test two case-mix models for depression treatment that permit comparisons of patient outcomes across diverse clinical settings. It assessed demographics; eight, diagnostic-specific, case-mix variables; and clinical status at baseline and follow-up for 187 patients. Regressions were performed to test two models for four dependent variables including depression severity and diagnosis. Individual treatment settings were then ranked based on a comparison of actual versus predicted outcomes using regression coefficients and predictor variables. A model inclusive of baseline physical health status and depression severity predicted depression severity, mental health, and physical health functioning at follow-up. A simpler model performed well in predicting depression remission. This study identifies variables to be included in case-mix adjustment models and demonstrates statistical methods to control for differences across settings when comparing depression outcomes.

Effects of repeated oral examinations on ophthalmology residents.

BACKGROUND/AIM: Oral examinations are required for board certification in Ophthalmology in the USA. The current literature offers no recommendation on the number of administrations during residency. The purpose of this study was to determine how often oral examinations (OEs) should be administered and what effects repeated OEs might have on residents' comfort level with OEs and confidence level in their knowledge base. METHODS: From 2004 to 2006, a structured oral examination was administered every 4 months to ophthalmology residents at the University of Arkansas for Medical Sciences. A survey was administered just prior to each oral examination. RESULTS: After two oral examinations, self-confidence and ability to self-assess one's knowledge increased and anxiety decreased in the residents. Residents' belief that they could pass an oral examination for board certification statistically improved after the third oral examination. CONCLUSIONS: To achieve the full benefits of oral examination training, the exam should be taken at least three times during residency. Formal, structured oral examinations, repeated over time, seem to reduce resident anxiety and improve the residents' ability to realistically assess their level of preparation for an OE.

Simple transvesical repair of vesicovaginal fistula.

A simple transvesical repair of uncomplicated small vesicovaginal fistulas was done successfully on 40 consecutive patients. More extensive procedures using combined intraperitoneal-transvesical approaches with extensive dissection and omental flaps probably are necessary for the repair of large, complicated or irradiated fistulas. However, these are not often encountered in urological practice. The method described herein is recommended for fistulas encountered more frequently.

Single daily doses of tobramycin in therapy of urinary tract infections.

Results of therapy with tobramycin for infections caused by susceptible pathogens have been impressive. The usual multiple dose regimen is aimed at maintenance of the serum concentration of tobramycin above the minimal inhibitory concentration of the causative pathogen throughout the course of therapy. Evidence is accumulating, however, that the urinary concentration of antibiotics may be of greater importance than the serum concentration in the treatment of urinary tract infections. This concept has been supported by results of studies with nitrofurantoin, naladixic acid, tetracycline, and, more recently, gentamicin. The present study of 90 patients with urinary tract infections treated with a single intramuscular daily dose of tobramycin resulted in round-the-clock urinary levels of tobramycin that exceeded the minimal inhibitory concentration of the offending pathogen. The clinical and bacteriologic response to therapy was excellent, and no oto- or nephrotoxicity occurred. This regimen frequently allows for therapy on an outpatient basis, fewer painful injections for the patient, and the saving of nursing time and expensive supplies.