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Biomedical subjects

D Rogers

Publications and source records attributed to D Rogers.

139 records · Page 8Linked to original sources
PubMedDate not supplied

Identification and characterization of cyclo(His-Pro)-like immunoreactivity in amniotic fluid.

Amniotic fluid (AF) from 25 term pregnancies was analyzed for cyclo(His-Pro)-like immunoreactivity (CHP-LI). CHP-LI was detected in all AF samples and was indistinguishable from synthetic CHP by immunoidentity, by gel chromatography on Sephadex G-25, and by high pressure liquid chromatography. The mean concentration of CHP-LI in AF was 13,622 +/- 1288 pg/ml (+/- SE) and concentrations were not altered by maternal labor. Plasma concentrations of CHP-LI were similar in 4 pregnant and 4 control subjects [2260 +/- 432 pg/ml vs. 2162 +/- 419 pg/ml (+/- SE), respectively]. We conclude that 1) CHP-LI is readily detected in AF from term pregnancies and is indistinguishable from synthetic CHP, and 2) concentrations of CHP-LI in human AF are significantly higher than concentrations of maternal plasma CHP-LI, suggesting CHP AF originates by mechanisms other than diffusion from maternal plasma.

Amniotic Fluid↗
PubMedDate not supplied

Magnetic resonance imaging in epilepsy: a controlled study.

The authors present a study of 50 patients with epilepsy and 14 healthy controls using a standardized magnetic resonance imaging (MRI) technique. Gross inspection of MRI scans identified major cerebral pathology and supplemented computerized tomography (CT) data. With further analysis of spin-lattice (T1) relaxation times, significant differences from controls emerged in epilepsy patients, even with normal CT scans, particularly in the temporal lobes. Patients with generalized seizures had increased T1 values in the thalamus. Also prolonged T1 in patients with focal seizures was noted on the ipsilateral side. These results of MRI imaging are discussed in relation to other imaging modalities in epilepsy. Further, the potential benefit of MRI in localization of seizure focus and specific pathophysiological mechanisms in seizure disorders are considered.

Adolescent↗
PubMedDate not supplied

Effect of prophylactic main pancreatic duct stenting on the incidence of biliary endoscopic sphincterotomy-induced pancreatitis in high-risk patients.

Pancreatitis is a common complication of endoscopic sphincterotomy. Cautery-induced papillary edema has been implicated as a possible cause. The objective of this study was to determine whether prophylactic stenting of the main pancreatic duct after endoscopic sphincterotomy in high-risk patients would reduce the incidence of pancreatitis. High-risk patients were defined as those with sphincter of Oddi dysfunction, small common bile duct diameter (< 10 mm), or those requiring pre-cut sphincterotomy. Patients were studied in a prospective fashion from October 1990 to April 1992 and were randomized to receive either a main pancreatic duct stent or no stent after biliary sphincterotomy. The stents were generally removed 10 to 14 days after placement. Fifty patients were randomized to the no-stent group and 48 patients were randomized to the stent group, but in five patients stent placement was unsuccessful. Pancreatitis occurred in 18% of patients in the no-stent group compared with 14% of patients in the stent group. Most cases of pancreatitis were mild, occurring in 10% of patients in the no-stent group and 12% of patients in the stent group. Moderate to severe pancreatitis occurred with an increased frequency in patients in the no-stent group (8%) compared with that in patients in the stent group (2%). Mean number of hospital days required to treat pancreatitis was 9.5 days in the no-stent group compared with 2.8 days in the stent group; however, none of these differences reached statistical significance. Small common bile duct diameter (< 6 mm) was found to be an independent risk factor for pancreatitis after endoscopic sphincterotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Common Bile Duct↗
PubMedDate not supplied

External beam radiation therapy to prevent postangioplasty dialysis access restenosis: a feasibility study.

PURPOSE: To evaluate the feasibility and short-term side-effects of postangioplasty external beam radiation for patients with compromised arteriovenous dialysis accesses. MATERIALS AND METHODS: Ten patients with compromised arteriovenous dialysis accesses were studied. Following confirmation of access compromise by an angiogram, patients were treated by a standard angioplasty +/- stent deployment. The target volume incorporated a margin of 1 cm beyond the angioplastied segment. The first 5 patients were treated to a dose of 12 Gy in two 6-Gy fractions spaced 48 h apart, whereas the next 5 patients were treated to 8 Gy in two similarly separated 4-Gy fractions. Five of the patients had at least one prior access that had failed. The current access had been in use for 6-52 months, and 5 of the 10 patients had at least one episode of compromise involving the current access. The length of stenosis ranged from 2 to 9 cm (mean 4.4 cm). All patients were followed clinically for adequacy of dialysis; a radiological follow-up with a fistulogram was performed for all in 3-monthly intervals. Follow-up ranged from 4 to 10 months, with a median follow-up of 6 months. RESULTS: There were no procedure-related complications. Three patients developed a restenosis at the site of the original stenosis, and one patient developed a restenosis at the edge of the stent. As part of the natural history of this process, five patients have also developed new lesions elsewhere in the proximal veins requiring radiological intervention. None of the patients showed any radiation-related side effects, either in the skin/ soft tissues, or in the vasculature on follow-up angiograms. CONCLUSIONS: Several different radiotherapeutic approaches are being currently investigated to prevent postangioplasty restenosis. There are several issues involved with the use of endovascular brachytherapy in these patients. On the other hand, given the superficial location of the dialysis access, we believe that external beam radiation offers a safe and simple method of radiation therapy in this setting. The clinical efficacy of this modality needs to be established through a randomized phase III trial.

Adult↗
PubMedDate not supplied

Comparison of the accuracy of positioning devices for radiation therapy of canine and feline head tumors.

The purpose of this retrospective study was to evaluate the repositioning accuracy of different positioning devices in order to determine their applicability for potential use in conformal radiation therapy for animals. Forty-four animals with spontaneous tumors of the head were included. The animals were divided into 3 groups determined according to the positioning device used. Group 1 animals were positioned using a thermoplastic mask. Group 2 animals were positioned using a head holder. Group 3 animals were positioned using the head holder and an inflatable pillow. The time of presentation determined which position device was used. Port films of the 44 patients were reviewed retrospectively, and the repositioning precision was recorded by measurements in three orthogonal planes. Groups 2 and 3 had significantly better repositioning accuracy (P < or = 0.05) compared to Group 1. The position variation was not significantly different (P < or = 0.05) between Groups 2 and 3 in the lateral and longitudinal direction. Group 3 had a median reposition variation of 0.5 to 1.0 mm, with a standard deviation of 1.0 to 1.5 mm.

Animals↗
PubMedDate not supplied

Intravenous procaine as a supplement to general anesthesia for carbon dioxide laser resection for carbon dioxide laser resection of laryngeal papillomas in children.

Procaine suppresses the cough reflex, decreases laryngeal irritability, and has general anesthetic properties. For these reasons, 14 pediatric patients undergoing CO2 laser resection of laryngeal papillomas were studied in which an intravenous infusion of procaine (1 mg/kg/min) was added to N2O-O2 halothane/enflurane general anesthesia immediately following endotracheal intubation. These patients were compared to nine patients receiving the same anesthesia without procaine. The mean age of both groups was 11 years. There was no difference between the groups in duration of anesthesia or surgery. Emergence, however, averaged 15 minutes in study patients compared to 36 minutes in the control group (p less than 0.01). There was no difference in anesthetic concentrations required to maintain satisfactory operative conditions in the two groups. Muscle relaxants were required intraoperatively in seven control patients but in none of the study patients. The surgeon ranked the operative conditions excellent in all study patients but poor in seven of the nine control patients. Five of the latter required postoperative treatment of laryngeal complications, including reintubation in three. Only one of the study patients had postoperative stridor. No evidence of procaine toxicity was noted in the study patients with total doses ranging from 500--3600 mg. Intravenous procaine is useful in pediatric patients having endoscopic laryngeal operations.

Anesthesia, Inhalation↗
PubMedDate not supplied

Can remotely sensed meteorological data significantly contribute to reduce costs of tsetse surveys?

A 0.125 degree raster or grid-based Geographic Information System with data on tsetse, trypanosomiasis animal production, agriculturerkina> and land use has recently been developed in Togo. This paper addresses the problem of generating tsetse distribution and abundance maps from remotely sensed data, using a restricted amount of field data. A discriminant analysis model is tested using contemporary tsetse data and remotely sensed, low resolution data acquired from the National Oceanographic and Atmospheric Administration and Meteosat platforms. A split sample technique is adopted where a randomly selected part of the field measured data (training set) serves to predict the other part (predicted set). The obtained results are then compared with field measured data per corresponding grid-square. Depending on the size of the training set the percentage of concording predictions varies from 80 to 95 for distribution figures and from 63 to 74 for abundance. These results confirm the potential of satellite data application and multivariate analysis for the prediction, not only of the tsetse distribution, but more importantly of their abundance. This opens up new avenues because satellite predictions and field data may be combined to strengthen or substitute one another and thus reduce costs of field surveys.

Africa, Western↗
PubMedDate not supplied

One year mortality outcomes of all coronary and intensive care unit patients with acute myocardial infarction, unstable angina or other chest pain in Hamilton, Ontario, a city of 375,000 people.

Over a one year period (1979 to 1980) all cardiac admissions to the coronary care units (CCU) and all intensive care unit (ICU) overflow admissions in Hamilton, Ontario, a city of approximately 375,000 people, were documented. Mortality status was determined one year following admission. There were 2004 individuals with either acute myocardial infarction (810), unstable angina (811) or other chest pain (783) as their first CCU/ICU admitting diagnosis that year. Mortalities in-hospital and by one year were: acute myocardial infarction 17 and 27%, respectively; unstable angina 1.5 and 9.2%, respectively; and other chest pain 1.4 and 3.1%, respectively. Of one year mortality following acute myocardial infarction, 63% occurred during the initial hospitalization, whereas this figure was 16% for unstable angina. For acute myocardial infarction, female mortality was greater than male mortality overall and in all but one age category. Mortality following acute myocardial infarction and unstable angina was strongly related to age. Repeat CCU/ICU admission occurred in 24% of acute myocardial infarction, 28% of unstable angina and 15% of other chest pain, while a total of death or nonfatal CCU/ICU readmission occurred in 31% of acute myocardial infarction, 32% of unstable angina and 17% of other chest pain.

Adult↗
PubMedDate not supplied

Coronary care unit utilization in Hamilton, Ontario, a city of 375,000 people.

All cardiac admissions to coronary care unit (CCU) beds and all intensive care unit (ICU) overflow admissions in Hamilton, Ontario, a city of 375,000 people, were documented over a one-year period, 1979-80. There were 4180 such admissions, 89% of them to CCUs. In the CCUs, 22% of patients had acute myocardial infarction, 24% unstable angina and 21% other chest pain. For myocardial infarction, hospitalization rate was 224 per 100,000, hospital mortality 42 per 100,000 and 48% of all myocardial infarction deaths in the community occurred in hospital. Of all myocardial infarction patients admitted to the CCU, 69% were correctly diagnosed on admission (sensitivity) and of all the admission diagnoses of myocardial infarction, 72% were eventually found to be correct (positive predictive value). Mean values for CCU patients overall were age 62.5 years, CCU stay 2.88 days and hospital stay 9.7 days; and for acute myocardial infarction patients in CCUs, age 63.4 years, CCU stay 3.98 days and hospital stay 13.28 days. For myocardial infarction, CCU mortality was 10.9%, hospital mortality 15.2% and, with the inclusion of ICU overflow patients, hospital mortality was 17.6%. Age-specific mortality for myocardial infarction was 9.7% age 45 to 64 years, and 32.8% over 70 years.

Adult↗