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Iron deficiency in women using modern copper intrauterine devices.

To evaluate the risk of iron deficiency and anemia connected with the use of modern copper intrauterine devices, serum ferritin, transferrin, iron, hemoglobin and hematocrit levels, red cell counts, and morphology, as well as red cell indexes were determined in 40 women and in 19 controls. Follow-up was for one year. Mean hemoglobin, hematocrit, serum iron, and serum ferritin levels decreased and serum transferrin levels increased significantly in the study population. About 20% of intrauterine device users but none of the controls showed signs of iron deficiency, and 10% had clinical anemia at 12 months of use. No differences were found between the three different copper intrauterine devices tested (Nova T, Multiload and Fincoid). Because the risk of anemia did not correlate with subjective evaluation of the amount of bleeding, it is recommended that hemoglobin levels should be determined for all intrauterine device users before its insertion and at six and 12 months of use. In those with decreased hemoglobin levels, serum ferritin should be measured and iron replacement instituted or the device removed.

Adult↗

Pretreatment of whole blood for use in immunochromatographic assays for hepatitis B virus surface antigen.

Immunochromatographic assays (ICAs) are also referred to as rapid tests, since they are simple and the results can be obtained within minutes after manually loading a few drops of a sample into each sample well of the test device. However, whole blood cannot be tested with ICA kits due to the visual hindrance caused by the color of red blood cells (RBCs), unless a cell-removing device such as a filter is mounted on the kits. Thus, when testing with blood, the advantage of the ICA kit is lost because of the additional time and machines required to coagulate and separate whole blood before preparing the serum. To overcome this limitation, whole-blood samples were added to a pretreatment solution to decolor the RBCs; the resulting mixtures were then loaded into the sample wells of the test device. The pretreating solution was composed of hydrogen peroxide (H(2)O(2)) to decolor the RBCs, Sag 471 (Osi Specialties) to restrain the mixture from vigorous foaming, sodium azide (NaN(3)) to inhibit the enzyme, which generates excessive foam at the beginning of decolorization, and EDTA as a chelating agent. As a result of this pretreatment, whole blood could be used with the ICA kit without reducing its simplicity and rapidity.

Anticoagulants↗

Treatment of noncyclic lactating dairy cows with progesterone and estradiol or with progesterone, GnRH, prostaglandin F2 alpha, and estradiol.

The efficacy of two programs for treating noncyclic cows was compared. In trial 1, 478 cows in five herds were randomly divided into two groups. Cows in one group (C group) were treated with an intravaginal progesterone device for 8 d followed in 48 h by 1 mg of estradiol benzoate to cows that had not been detected in estrus since device removal. Those in the other group (CGP group) were treated with progesterone and estradiol as for the C group plus 10 micrograms of a GnRH agonist (buserelin) at device insertion and 25 mg of PGF2 alpha 7 d after device insertion. In trial 2 with 729 cows in nine herds, the treatments were similar to those in trial 1 except that the duration of progesterone treatment was 7 d. No significant difference was found between trials and results from both trials were combined. Compared with C group cows, CGP group cows had a greater estrous response rate (93.2 vs. 89.1%), a greater conception rate to first artificial insemination (AI, 47.1 vs. 29.4%), marginally lower conception rate to second AI (52.9 vs. 59.7%), lower nonpregnancy rate (8.3 vs. 11.1%), and shorter intervals from the start of breeding to conception by AI (9.8 vs. 15.3 d) or by AI or natural mating (21.6 vs. 26.3 d). The treatment protocol used for the CGP group achieved better reproductive performance than that used for the C group.

Animals↗

Accuracy of the Dinamap Portable Monitor, model 8100: a review of the evidence for accuracy.

Conventional measurement of blood pressure is fraught with many potential errors '1'. Automated blood pressure measuring devices remove observer bias and permit repeated blood pressure measurements at predetermined intervals, features which have obvious attractions in clinical practice and in hypertension and epidemiological research. However, such devices, which can be expensive, must be shown to be as accurate as the conventional technique which they are designed to replace '2'. A number of Dinamap models are available '3', the Dinamap Portable Monitor, Model 8100 (Critikon, Tampa, Flirida, USA) being one of the most popular automated devices used in clinical practice and in hypertension research, despite reports demonstrating that it is inaccurate in certain clinical circumstances. We therefore decided to review the literature on the Dinamap 8100. Ten papers '4-13' concerned specifically with the accuracy of this model were identified; they all acknowledged its inaccuracy but not all reached the same conclusions regarding the influence of such inaccuracy in practice.

Journal Article↗

A respiratory gas exchange catheter: in vitro and in vivo tests in large animals.

OBJECTIVES: Acute respiratory failure is associated with a mortality of 40% to 50%, despite advanced ventilator support and extracorporeal membrane oxygenation. A respiratory gas exchange catheter (the Hattler Catheter) has been developed as an oxygenator and carbon dioxide removal device for placement in the vena cava and right atrium in the treatment of acute respiratory failure to improve survival. METHODS: Differing from a previously clinically tested intravenous gas exchange device (ie, IVOX), the Hattler Catheter incorporates a small, pulsating balloon surrounded by hollow fibers. The pulsating balloon redirects blood toward the fibers, enhances red cell contact with the membrane, and significantly improves gas exchange so that smaller catheter devices are still efficient on insertion and can be inserted through the jugular or femoral vein. Devices were tested in mock circulatory loops and in short-term (8 hours) and long-term (4 days) experiments in calves to study the effect of various sized balloons and the anatomic location of the device in the venous system as a function of hemodynamics and gas exchange. RESULTS: In vitro performance in water demonstrates an oxygen delivery (Vo(2)) of 140 +/- 8.9 mL. min(-1). m(-2) and a carbon dioxide removal (Vco(2)) of 240 +/- 6.1 mL. min(-1). m(-2). Acute in vivo experiments demonstrate a maximum carbon dioxide consumption of 378 +/- 11.2 mL. min(-1). m(-2). Devices positioned in the right atrium had an average carbon dioxide exchange of 305 mL. min(-1). m(-2), whereas in the inferior vena cava position carbon dioxide exchange was 255 mL. min(-1). m(-2). Devices have been tested long term in calves, with gas exchange rates maintained over this time interval (carbon dioxide consumption, 265 +/- 35 mL. min(-1). m(-2)). Plasma-free hemoglobin levels at the end of 4 days have been 4.8 +/- 3.2 mg/dL. Hemodynamic measurements, including a decrease in cardiac outputs and increased mean pressure decreases across the device become significant only with the larger balloon (40-mL) devices (P <.05, 40-mL vs 13-mL devices). Autopsies show no end-organ damage. The device linearly increases its carbon dioxide output with progressive hypercapnea, predicting its ability to meet tidal volume reduction in the therapy of respiratory failure. CONCLUSIONS: Progress has been made toward developing an intravenous gas exchange catheter to provide temporary pulmonary support for patients in acute respiratory failure.

Animals↗

Evaluation of new blood culture processing systems.

The Antimicrobial Removal Device (ARD; Marion Scientific) was evaluated in vitro with simulated blood culture samples in fresh blood and clinically with samples from potentially septic patients to test its ability to remove antimicrobial agents and recover bacteria from blood culture specimens containing these drugs. In simulated specimens, the ARD was evaluated for adverse affects on microorganisms as well as compared with lysis-centrifugation (Isolator; Du Pont Co.), biphasic brain heart infusion bottles, and tryptic soy broth bottles for antimicrobial inactivation and organism recovery. There was no adverse effect of the ARD on organisms during a 4-h test period. The ARD was the only system to actually inactivate antimicrobial agents and removed greater than 99.2% of all antimicrobial agents tested from spiked and clinical specimens. Overall, with simulated blood culture specimens, the ARD recovered 90% of bacteria spiked into fresh blood containing antimicrobial agents, Isolator recovered 73%, biphasic brain heart infusion bottles recovered 31%, and tryptic soy broth bottles recovered 24%. In the clinical study, 43 of 86 clinically significant isolates were recovered only by ARD-assisted processing, 6 were recovered only by conventional processing, and 37 were recovered by both methods (the advantage of ARD processing over conventional processing in the clinical study was significant at P less than 0.001). Both clinical and simulated specimens demonstrated the ARD-associated blood culture processing to be the most efficient method for the isolation of microorganisms from specimens containing antimicrobial agents.

Anti-Bacterial Agents↗

Outcome after implantation of a novel prosthetic anal sphincter in humans.

BACKGROUND: A novel prosthetic anal sphincter (PAS) has been developed that aims to occlude by flattening and angulating the bowel, reproducing the action of the puborectalis muscle. The safety of the PAS has been confirmed in biomechanical, in vitro and long-term animal survival studies. The Medical Devices Agency approved implantation in 12 patients. METHODS: The PAS was placed in the pelvis around the anorectal junction via a transabdominal approach in 12 patients with severe faecal incontinence. The device was activated 6 weeks after surgery. Fibreoptic examination of the mucosa below the device was undertaken at various intervals during review. RESULTS: At a median follow-up of 59 (range 30-72) months nine of the 12 patients had a functioning PAS. There were no device-related infective complications after the initial operation but one patient developed pseudomembranous colitis and had the device removed. The PAS was effective in restoring continence in ten of 11 patients. Median (range) Cleveland Clinic continence scores improved from 16 (7-20) before to 3 (0-7) after surgery. In two patients the PAS was eventually removed owing to infection after revisional surgery. There was no clinical or histological evidence of gastrointestinal mucosal ischaemia. CONCLUSION: The PAS was effective in restoring continence. There was no device-related infection after the initial operation, no device erosion and no clinical or histological evidence of gastrointestinal ischaemia.

Adult↗

Improved survival in patients with acute myocarditis using external pulsatile mechanical ventricular assistance.

BACKGROUND: Acute myocarditis remains a disease with a variable clinical course, from full ventricular recovery to complete heart failure; to date, few cases have been reported that describe the efficacy of temporary mechanical ventricular assistance for its treatment. METHODS: We evaluated the voluntary world registry with the use of an external pulsatile ventricular assist device (the ABIOMED BVS 5000 [BVS]) for acute myocarditis to determine the impact of mechanical ventricular assistance on outcome. Variables analyzed included patient demographics, serum chemistries, and overall hemodynamics prior to BVS, while on BVS support, and after BVS explanation. Postoperative parameters included re-operation, bleeding, respiratory failure, renal failure, and infections, neurologic, or embolic events. RESULTS: Eighteen patients in the ABIOMED world registry underwent BVS implantation for myocarditis; 11 (61.1%) had complete pre-operative and hemodynamic data for analysis. Patients were supported for 13.2 +/- 17.0 days, after which time 7 (63.6%) patients survived to explanation of the device and 2 (18.2%) underwent transplantation. Elevated admission serum chemistries (blood ureanitrogen [BUN], creatinine, transaminases) and hemodynamics (central venous pressure [CVP], mean pulmonary arterial pressure [PAP], pulmonary capillary wedge pressure [PCW], cardiac index [CI], all normalized during the period of device support. Estimated ejection fractions in the 7 explanted patients ranged between 50 to 60% at routine evaluation 3 years after device removal. CONCLUSIONS: Temporary mechanical ventricular assistance represents an efficacious therapy for acute myocarditis in patients with hemodynamic decompensation despite maximal medical therapy. Failure to achieve full ventricular recovery while on device support still allows for other surgical alternatives, including implantation of a long-term implantable ventricular assist device, or cardiac transplantation.

Acute Disease↗

Jarvik 2000 heart: potential for bridge to myocyte recovery.

BACKGROUND: Mechanical bridge to left ventricular recovery is an emerging strategy for the treatment of heart failure. We sought to validate the use of a new intracardiac axial flow impeller pump for this purpose. METHODS AND RESULTS: The Jarvik 2000 Heart was implanted into 30 sheep to ascertain mechanical reliability, biocompatibility, and hemodynamic function. We attempted but failed to anticoagulate with warfarin. Elective explants with survival were performed in 3 animals to simulate bridge to recovery. Extensive autopsy studies were performed in all other animals. At speeds between 8000 and 12 000 rpm the device pumped up to 8 L/min, captured all mitral flow, and augmented cardiac output with elevation of mean arterial pressure. The pump was silent and hemolysis negligible. Nonpulsatile flow did not adversely affect neurological or renal function. Device removal proved straightforward and safe. A fractured inflow bearing occurred in 1 early model. There were no other pump failures, but power interruption occurred when the sheep chewed the cables or head-butted the percutaneous pedestal. At autopsy, there was no thromboembolism or primary thrombus formation in any device. Pump occlusion occurred in 2 sheep with bacterial endocarditis. One electively explanted pump, previously switched off for 5 months, had no thrombus in the device or vascular graft. CONCLUSIONS: The Jarvik 2000 Heart is a major advance in blood-pump technology and increases the scope of mechanical circulatory support. Reliability and ease of removal favor its use for bridge to myocyte recovery, as well as for bridge to transplantation or long-term support.

Animals↗

The artificial sphincter for urinary continence.

Artificial urinary sphincters were implanted in 30 incontinent children between four and 17 years of age. At follow-up for periods from three months to four years, 28 children are continent for at least three hours during the day and are dry at night. Two have had the device removed because of erosion and are still incontinent. 18 children empty their bladders completely, but 10 require clean intermittent catheterization to do so. None of the children has required revision of the device because of somatic growth.

Adolescent↗

Initial results of a new access device for hemodialysis technical note.

BACKGROUND: A new subcutaneous device (DIALOCKtrade mark) provides vascular access to patients who currently require hemodialysis (HD). The device consists of a port-like valve, implanted subcutaneously below the clavicle, which provides a linear flow passage to two catheters placed in the right atrium via the internal or external jugular vein. The valve is accessed percutaneously with needle-cannulas that functionally convert the device to twin catheters for connecting the patient to the HD lines. METHODS: The device was implanted in 10 outpatients under local anesthesia. Patients used the device during dialysis 3 times/week, and data were collected on blood flow, pressures, adverse events and patient and nurse satisfaction. RESULTS: The device was used for HD almost immediately (median 3 days after implantation) and functioned successfully for more than nine months (mean +/- SD 7.3 +/- 1.5) in all but one patient who died of unrelated causes after one month; there were >800 dialysis sessions total. Blood flows over 300 ml/min were consistently achieved (average 326 +/- 40) with venous and arterial pressures of 200 +/- 44 and -246 +/- 29 mm Hg, respectively. After 66 patient-months, condition of the needle puncture sites remained satisfactory. Five systemic infections occurred in four patients, producing 2.3 bacteremic episodes per 1000 patient-days. All resolved without the need for device removal. There were no infections at the puncture sites. Two patients required fibrin sheath stripping of their catheters, one whose heparin lock was not changed for 23 days (for reasons unrelated to the device). Patient and nurse acceptance was excellent. CONCLUSION: The device represents a positive improvement in the area of HD access.

Adult↗

Testing force systems and biomechanics--measured tooth movements from differential moment closing loops.

Orthodontic tooth movement can be compared to a stimulus-response model, where the stimulus is the applied force system and the response is the resulting tooth movement. Although the principles of mechanics have been applied to orthodontic appliance design, the expression of treatment responses to the force systems is less well known. The purpose of this study was to compare measured tooth movements with the theoretical force system exerted by differential moment closing loops. Sixteen subjects requiring maximum posterior anchorage control were selected to participate in this prospective investigation. T-loop springs designed to deliver a differential moment-to-force ratio to the posterior vs the anterior teeth were used. Initial cephalometric radiographs were taken with special devices attached to the molar and canine teeth to allow precise identification. Immediately after the radiograph, the T-loop archwires were inserted and activated. After an observation period of approximately 90 days, the wires were removed, devices reinserted into the molars and canines, and a second cephalometric radiograph was obtained. Superimposition techniques were used to compare the actual tooth movements. The results showed tooth movements consistent with the prescribed force system. The anterior teeth, as represented by the canines, were retracted an average of 1.73 mm, whereas the posterior anchorage (molars) moved mesially only 0.50 mm. Furthermore, the canine teeth exhibited tipping or translation, and the molars showed mesial root movement. The variability of the treatment response as a function of the stimulus (appliance design), response (biological variation), and measurement technique was described.

Adolescent↗

Response of postpartum beef cows to exogenous progestogens and gonadotropin releasing hormone.

Plasma progesterone (P4) profile and estrous detection were used during three experiments to evaluate the effects of exogenous progestogens on the life span of gonadotropin releasing hormone (GnRH)-induced corpora lutea (CL) in postpartum (pp) beef cows. Experiment 1 utilized primiparous fall-calving cows (n = 28, trial 1); and spring-calving cows (n = 29, trial 2). On d 18 to 27 pp (d 0) all cows received intravaginal devices containing either P4 or no P4 (NP) for 5 d. On d 5 the devices were removed and calves were either removed (CR) or were present (CP) with half of the cows within steroid group. At 50 h after device removal, 500 micrograms of GnRH was given (iv) to all cows, and weaned calves were reunited with their dams. The induced CL had a normal life span (greater than 16 d) in 17 and 86% (trial 1) and 8 and 79% (trial 2) of NP and P4 cows, respectively. Calf removal did not affect (P greater than .10) the life span of the CL. In Exp. 2, spring-calving multiparous cows (d 18 to 24 pp; d 0) received either no P4 (NP; n = 19), P4 for 6 d via intravaginal devices (P4H; n = 19) or a single im injection of 300 mg P4 (P4 IM; n = 18). At 48 h after device removal or at 8 d after the injection of P4, half of the cows within steroid group received either 500 micrograms GnRH or saline. Corpora lutea had a normal life span in 0, 11, and 80% of NP, P4 IM and P4H cows, respectively, that received GnRH and in 22% of P4-saline cows. In Exp. 3, fall-calving multiparous and primiparous cows (d 25 to 31 pp) received either no progestogen (NP; n = 20), P4 via intravaginal devices for 5 d (P4H; n = 21) or melengestrol acetate (MGA; .5 mg.head-1.d-1 for 5 d orally, n = 15). At 48 d after device removal or at 72 h after the last MGA feeding, all cows received 500 micrograms GnRH. Progesterone post-GnRH injection was increased (greater than 1 ng/ml) at d 7 in 64, 100 and 100%, and remained elevated at d 14 in 11, 46 and 100% of NP, MGA and P4H cows, respectively. For all experiments plasma P4 was increased (range 2 to 5 ng/ml) when the devices containing P4 were in place, then decreased (less than 1 ng/ml) by 48 to 50 h after device removal.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Rifampin-impregnated silicone catheters: a potential tool for prevention and treatment of CSF shunt infections.

BACKGROUND: Infection continues to be one of the major complications of cerebro-spinal fluid shunting procedures. Recent insights in the pathophysiological mechanism of these foreign body infections have elucidated the difficulty of achieving successful treatment without device removal. The development of a rifampin-impregnated silicone catheter yielded excellent results in infection prevention and treatment in vitro as well as in an animal model. PATIENTS AND METHODS: Here, we describe the application of this device in two patients with a complicated course of shunt infection. RESULTS: In one patient the rifampin-impregnated shunt system was implanted after external drainage to prevent further infection. The shunt infection of the second patient was treated by replacement of the infected shunt system with a rifampin-impregnated device. Both patients recovered immediately without any signs of adverse effects and the two shunt systems have now been working properly for more than 36 and 21 months, respectively. CONCLUSION: These results suggest that rifampin-impregnated silicone catheters could become a valuable tool in the treatment and prevention of shunt infections.

Anti-Bacterial Agents↗

Long-term suppressive antimicrobial therapy for intravascular device-related infections.

BACKGROUND: Long-term suppressive antimicrobial therapy is an alternative treatment choice in patients with medical device-related infection who are not eligible for surgical device removal for attempted cure. There is a paucity of data published that examines this treatment option. METHODS: Members of the Infectious Diseases Society of America's Emerging Infections Network were polled to identify patients with intravascular device-related infections who were not candidates for surgery and were given long-term antimicrobial therapy to suppress clinical manifestations of infection. RESULTS: Clinical and microbiologic data were collected retrospectively for 51 patients. Sixty-nine percent of patients were men; vascular grafts were the most common type of medical device infected [30 (58.8%) patients]. Sixty-three percent (32 of 51) of cases involved gram-positive cocci. A variety of antimicrobials were administered as chronic suppressive therapy, with beta-lactams used most frequently (39.2%). Therapy ranged from 3 months to 10 years. Three (7.32%) of 41 patients in whom follow-up data were available developed relapsing infection while on long-term suppressive therapy. Three other patients suffered drug adverse events. CONCLUSIONS: Overall, long-term suppressive therapy was well-tolerated and efficacious in preventing signs of infection relapse.

Adolescent↗

Evaluation of an implantable ventricular assist system for humans with chronic refractory heart failure. Device explant protocol.

An explant protocol was developed to investigate the effects of implantation of a left ventricular assist system (LVAS) manufactured by Novacor Division, Baxter Healthcare Corporation on the function of end organs (such as the brain, the kidney, the liver), with particular interest in examining possible complications due to LVAS support. Emphasis was placed on an analysis at the time of device removal and/or autopsy of 1) the local LVAS-host interface; 2) remote cardiovascular and end-organ effects; and 3) the impact of chronic circulatory support on the native heart. To accomplish these objectives, tissue and device samples must be obtained in an appropriate fashion to ensure photographic documentation, microscopic examination, microbiologic and biochemical assays, and compliance with regulatory and manufacturer requirements. This article describes the techniques and protocol that were proposed to ensure the quality of device explant and tissue analysis.

Autopsy↗

One-day admission for lung lobectomy: an incidental result of a clinical pathway.

BACKGROUND: Most complications after lung lobectomy are related to pain, narcotic analgesia, and inactivity. When the operation is performed with the goal of minimizing postoperative pain, and when rapid restoration of activity and patient independence can be achieved, most postoperative complications can be obviated and early discharge can be attained. METHODS: Since March 1996, we have performed 10 consecutive elective major lung resections (8 lobectomies and 2 bilobectomies) for neoplastic (n = 8) and benign inflammatory (n = 2) lesions. Of the 10 patients, 4 were men and 6 were women ranging in age from 58 to 77 years (mean age, 66 years). Extensive preoperative patient and family education was provided in the surgeon's office. Same-day admission was followed by an oblique muscle-sparing minithoracotomy to access the chest cavity. A meticulous operation, with special attention to minimizing air leak and postoperative discomfort, was performed. Intercostal nerve cryolysis was used as the main method of analgesia. RESULTS: All patients underwent the planned operation through a minithoracotomy and were extubated in the operating room. All patients exhibited normal ipsilateral shoulder girdle mobility in the recovery room and none required intravenous narcotics after leaving this unit. All patients were out of bed the day of the operation. The chest tube was removed the night of the operation in 2 patients, the morning after the operation in 6 patients, and on the second postoperative day in 1 patient. One patient who was discharged with a Heimlich valve had this device removed in the office 4 days after the operation. After the chest tubes were removed, there were no instances of pneumothorax. All 10 patients were able to ambulate independently on the first postoperative day. Eight patients were discharged home the morning after the operation and 2 on the second postoperative day. None of the patients have required readmission related to their operation or have exhibited evidence of postthoracotomy pain syndrome. CONCLUSIONS: We have developed a clinical pathway based on patient education, meticulous minimally invasive operation, cryoanalgesia, and quick resumption of physical activity. Our preliminary experience with this approach has shown minimal morbidity, rapid restoration to preoperative status, and, for most patients, a 1-day hospital stay after major lung resection.

Aged↗

Clinical longevities of ramus frame implants.

A variety of ramus frame dental implant designs is indicated for endosseous restoration to retain lower dentures, and the different designs utilize various alloys. The objective of this study was to present an analysis of the clinical applications for ramus frame dental implants with emphasis on the statistics of clinical longevities. The investigation involved an extensive statistical evaluation and, when possible, metallographic, scanning electron microscopic, histological, mechanical, and stereomicroscopic surface evaluations. The statistical analysis presents averages and percentages of devices in place vs. devices removed. Analyses of survival probability were also determined by means of the Kaplan-Meier statistical methods. A comparison of these results with the general criteria listed in the Harvard Conference shows that more than 75% of the implant devices were in place after five years.

Dental Alloys↗