Search PubMed⌕ Search

Biomedical subjects

F J Miller

Publications and source records attributed to F J Miller.

198 records · Page 11Linked to original sources
PubMedDate not supplied

Iced saline perfusion of Simon Nitinol Filters: improved control during transfemoral delivery: technical note.

Simon Nitinol inferior vena cava filters were placed via a transfemoral venous route in 14 patients. The initial seven caval filters were placed using refrigerated saline infused at a slow rate. In these cases, Simon Nitinol filter expansion was explosive and difficult to control. In the next seven caval filters, the saline infusate was partially frozen and delivered at a higher infusion rate. In this group, the Simon Nitinol filter expansion was noticeably slower with improved ability to control filter placement in the inferior vena cava.

Cold Temperature↗
PubMedDate not supplied

Intervention for gallbladder disease.

Intervention in the gallbladder includes therapy for both acute and chronic gallbladder disease. Although drainage for acute cholecystitis has been described by several investigators, the future seems to be in removal of calculi in symptomatic patients without acute cholecystitis. The technique for acute gallbladder drainage is described in detail using ultrasound guidance with or without fluoroscopy; for symptomatic gallstones, the clinical and technical aspects are described. We also discuss in detail the totally new concept for gallstone removal and the initial patient work using rotational contact lithotripsy with the Kensey-Nash device.

Cholelithiasis↗
PubMedDate not supplied

The effects of intratracheally administered coarse mode particles on respiratory tract infection in mice.

Because coarse mode particles are rarely studied in their existing size ranges (greatest mass about 5-7 microns, aerodynamic diameter), we investigated the effects of four such particles, quartz, ferric oxide, calcium carbonate, and sodium feldspar, on host defenses against bacterial pulmonary infection. Mice which received intratracheal instillations of 10, 33, and 100 micrograms/mouse were exposed within an hour to aerosols of viable Streptococcus, and pneumonia-induced mortality was measured. At 33 and 100 micrograms/mouse, all particles significantly increased mortality. At the lower dose, only Fe2O3 caused a significant increase in mortality. To evaluate potential delayed effects, mice were challenged with the bacteria 24 h after exposure to 100 micrograms particles/mouse. Delaying the challenge did not significantly alter the response, except for the sodium feldspar group for which a partial recovery was observed. When mice exposed to 100 micrograms particles/mouse received aerosols of Klebsiella pneumoniae 24 h later, there was no significant effect on pulmonary bactericidal activity. For the model system used, it appears that Fe2O3, CaCO3, and sodium feldspar have effects roughly equivalent to quartz.

Aerosols↗
PubMedDate not supplied

Influence of ozone on pentobarbital pharmacokinetics in mice.

Previous studies have indicated that acute exposure to ambient concentrations of ozone (O3) as low as 196 micrograms/m3 (0.1 ppm) increases pentobarbital (PEN)-induced sleeping time in female mice. To elucidate potential mechanisms involved, additional studies were performed. A 3 h exposure to 9800 micrograms O3/m3 (5 ppm) did not affect brain concentrations of PEN at time of awakening, even though sleeping time was increased. Exposure for 3 h to 9800 micrograms O3/m3 (5 ppm) did not alter the pattern of brain or plasma metabolites of PEN. Pentobarbital clearance followed first-order kinetics with a one-compartment model. Mice exposed to 9800 micrograms O3/m3 (5 ppm) for 3 h had a 106% increase in the plasma half-life of pentobarbital; at 1960 micrograms O3/m3 (1 ppm) for 3 h, a 71% increase was observed. It therefore appears possible that PEN-induced sleeping time might be increased due to an decrease in hepatic metabolism of PEN.

Animals↗
PubMedDate not supplied

Insensitivity of color Doppler flow imaging for detection of acute calf deep venous thrombosis in asymptomatic postoperative patients.

PURPOSE: Although color Doppler flow imaging (CDFI) has been shown to accurately depict calf vein thrombosis in symptomatic patients, this technique has not been proved accurate for detection of calf vein thrombosis in a population restricted to asymptomatic postoperative patients. PATIENTS AND METHODS: To evaluate the accuracy of CDFI in asymptomatic postoperative patients, both CDFI and contrast venography were performed on 78 limbs of 76 patients without symptoms of deep venous thrombosis (DVT) who had undergone either hip or knee replacement. CDFI and venographic examination were interpreted blindly with respect to the results of the other modality or clinical findings. Venography was the standard for comparison of results. RESULTS: Fifty-six percent of CDFI examinations of the calf vein were technically adequate. The remaining studies were compromised technically by limb swelling and/or obesity. For the technically adequate CDFI studies, calf vein thrombosis was detected in eight of 10 patients. Calculated sensitivity in this cohort was 80%, and specificity was 97%. The sensitivity of CDFI for acute calf DVT in all patients, regardless of image quality, was 42%. CONCLUSION: These observations suggest that state-of-the-art CDFI is not an accurate examination for acute calf vein DVT in asymptomatic postoperative patients. CDFI is associated with a high rate of technically compromised studies and relatively low sensitivity in studies that are deemed technically satisfactory. These observations do not preclude the use of CDFI in postoperative patients for detection of thrombus extension into the popliteal vein or for detecting thrombosis of more proximal lower extremity veins.

Female↗
PubMedDate not supplied

Percutaneous nephrostomy for nonoperative management of fungal urinary tract infections.

PURPOSE: Percutaneous nephrostomy has proved to be an important modality in the nonoperative treatment of bacterial pyonephrosis. The role of this technique in the management of fungal pyonephrosis continues to evolve. The authors retrospectively reviewed their experience with percutaneous nephrostomy in the management of fungal pyonephrosis. PATIENTS AND METHODS: Seven patients, two neonates and five adults, were identified with proved fungal infections. Eleven percutaneous nephrostomy tubes were placed, all with use of the Seldinger technique. RESULTS: Percutaneous nephrostomy allowed (a) prompt microbiologic diagnosis of fungal infection (Candida albicans in six patients, Torulopsis glabrata in one); (b) urinary diversion with subsequent improvement in renal function, enabling systemic administration of potentially toxic antifungal drugs 5-fluorocytosine and amphotericin B (four patients); (c) local irrigation with amphotericin B (four patients), (d) guidewire fragmentation of fungus balls (two patients); and (e) introduction of a Simpson atherectomy device to obtain biopsy specimens from an obstructing ureteral polypoid lesion (one patient). The funguria was successfully eradicated in six patients, one of whom died on the 39th hospital day of a pulmonary embolus and another of whom died of extensive small bowel infarction during hospitalization. The one patient whose outcome of antifungal treatment remains unknown died at home with a functioning percutaneous nephrostomy 23 days after the procedure. CONCLUSION: Percutaneous nephrostomy may play a role in the non-operative management of fungal urinary tract infection.

Aged↗
PubMedDate not supplied

Transjugular intrahepatic portosystemic shunt: midterm clinical and angiographic follow-up.

PURPOSE: To determine the impact of Child class and indication for transjugular intrahepatic portosystemic shunt (TIPS) placement on patient survival and reintervention rate. MATERIALS AND METHODS: Metal stents were used to successfully create single shunts in 63 patients during a 3-year period. Angioplasty and repeated stent placement were used to maintain shunt patency, and patients were followed up clinically and angiographically. Statistical analysis of survival and patency was performed with Kaplan-Meier product-limit survival functions. A Karnofsky performance status score was derived for each follow-up encounter. RESULTS: Early and late mortalities varied with Child class and procedure indications. Thirty-day mortality was 19% overall (12 of 63 patients) and was 33% for Child class C patients (10 of 30 patients). Thirty-day mortality was 31% (four of 13 patients) for patients with ascites and 16% (eight of 50 patients) for those with bleeding. Reintervention was required in 20 of 33 patients and was not predictable on the basis of Child class. CONCLUSION: Child class and indication for procedures are significant predictors of survival but not of the need for reintervention. Ninety-day survivors had uniformly good performance status.

Esophageal and Gastric Varices↗
PubMedDate not supplied

Percutaneous management of hepatic abscess: a perspective by interventional radiologists.

Techniques for treating hepatic abscess have evolved rapidly during the past decade. For many years, the traditional treatment was surgical drainage. The development of modern imaging modalities, such as CT and US, has not only made the diagnosis more certain, but has also introduced a variety of percutaneous treatment options. Pyogenic hepatic abscess is now accepted as a medical/radiologic disease requiring surgical intervention only for correctable offending causes or for failed radiologic evacuation. Drainage via an indwelling catheter has been the traditional method of percutaneous treatment. However, indwelling catheters have disadvantages, including patient discomfort, the nuisance of catheter maintenance, and postprocedural complications. The technique of simple aspiration and intracavitary antibiotics as advocated by McFadzian et al, with excellent results confirmed by Giorgio et al, is a promising alternative to prolonged catheter drainage, and may be the biggest advancement in the management of hepatic abscess in 80 years. Surgeons have recently accepted radiologic drainage; now we need to see if interventional radiologists and surgeons will accept evacuation without indwelling catheter drainage. The role of interventional techniques for nonpyogenic hepatic abscesses will vary considerably. Mortality will still occur in the pyogenic varieties but should be related to underlying disease rather than the abscess itself.

Drainage↗
PubMedDate not supplied

Intraluminal irradiation for TIPS stenosis: preliminary results in a swine model.

PURPOSE: To evaluate the ability of 32phosphorus intraluminal irradiation to reduce pseudointimal hyperplasia in a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: TIPS were successfully placed in 11 swine with normal portal pressures. Six animals received 15.2 Gy intraluminal irradiation to the hepatic parenchyma and venous outflow tract at the time of TIPS placement with use of a NA32P-filled balloon angioplasty catheter. Five control animals underwent TIPS and balloon angioplasty with saline. All animals were followed up for 28 days, at which time percutaneous portography was performed, the animals were killed, and the tissue around the TIPS stent was processed for histologic analysis. Maximum pseudointimal hyperplasia as a percentage of estimated TIPS diameter was calculated for each animal. RESULTS: At the time of euthanasia, all five control TIPS and all but one irradiated TIPS were occluded. Histologic analysis demonstrated considerable variability in the degree of pseudointimal hyperplasia within each TIPS and between animals. No statistically significant difference was found in the maximum pseudointimal hyperplasia, measured as a percentage of stent radius, between control (80.2%+/-17.4%) and irradiated animals (69.2%+/-25.2%). CONCLUSIONS: Irradiation of TIPS with 15.2 Gy 32P delivered at the time of TIPS placement did not significantly improve TIPS patency or reduce the degree of pseudointimal hyperplasia in swine with normal portal pressures.

Angioplasty, Balloon↗
PubMedDate not supplied

Influence of ozone and nitrogen dioxide on hepatic microsomal enzymes in mice.

Since ambient concentrations of ozone and nitrogen dioxide increase drug-induced sleeping time in female mice, potential mechanisms were sought by investigating the effects of these gases on hepatic microsomal mixed-function oxidases in female CD-1 mice. A 3-h exposure to 9800 microgram O3/m3 (5 ppm) or 9400 microgram NO2/m3 (5 ppm) did not change the concentration of cytochrome P-450 significantly. Aniline hydroxylase, but not aminopyrine N-demethylase or p-nitroanisole O-demethylase, activities were increased following a 3-h exposure to 9400 microgram O3/m3 (5 ppm). Aniline hydroxylase activity was also increased after a 2-d (5 h/d) exposure to 1960 microgram O3/m3 (1 ppm). None of these enzyme activities were affected by a 3-h exposure to 9400 microgram NO2/m3 (5 ppm). In these studies, O3 sometimes increased wet liver weight, and thus additional experiments were conducted. A 5-h exposure to 1960 microgram O3/m3 (1 ppm) caused a lesser decrease in body weight than the decrease observed after a similar air exposure. Liver wet weights were elevated after O3 exposure. However, there were no significant changes in liver dry weight, liver dry-to-wet-weight ratio, or ratios of liver (wet or dry) weight to body weight. From these data, it is concluded that mechanisms other than those investigated are responsible for the effect of O3 and NO2 on drug-induced sleeping time. However, the activity of one mixed-function oxidase was slightly increased by O3, indicating a hitherto unrecognized systemic effect of O3 exposure.

Animals↗
PubMedDate not supplied

Alterations in bacterial defense mechanisms of the lung induced by inhalation of cadmium.

Exposure to an aerosol of CdCl2 has a marked proclivity to reduce the ability of the lung to defined itself against microbial insults. A significant enhancement of mortality was observed in mice exposed to CdCl2 concentrations ranging from 80 to 1600 mug/m3 prior to being challenged with viable streptococci. The increase in percent mortality above control varied from 15% at the lowest CdCl2 concentration to approximately 70% at the highest concentration. In order to determine the various mechanistic factors which may explain the observed effect of reduced host resistance to infection, a variety of pulmonary defense systems was studied. There was a significant decrease in the total number of alveolar macrophages recoverable from rat lungs immediately after completion of the exposure regimen. The number of macrophages returned to normal (about 5.5 million) within 24 hours after cessation of the exposure. However, total polymorphonuclear leucocytes increased 1.5 million immediately after completion of the exposure and 13 million within 24 hours after cessation of the exposure. Lymphocyte numbers were not affected by these exposure levels. Data concerning clearance of streptococci from the lung following CdCl2 exposure closely correlated with the observed mortality pattern.

Aerosols↗