Search PubMed⌕ Search

Biomedical subjects

D J Patterson

Publications and source records attributed to D J Patterson.

At least 91 records · Page 5Linked to original sources
PubMed1981

Effects of caesarean section, retained placenta and vaginal or uterine prolapse on subsequent fertility in beef cattle.

Data collected at the Livestock and Range Research Station, Miles City, Montana, on 13,296 calving from the years 1963 through 1977 were used to evaluate subsequent reproductive performance of dams experiencing caesarean section, retained placenta or vaginal or uterine prolapse. A total of 121 caesarean sections (.9% of all calvings) was performed from 1963 through 1977, with the highest incidence reported among first-calf 2- and 3-year-old dams. Fall pregnancy rate among the 105 dams that had caesarean deliveries was 52.4%, which was 26.6% lower (p less than .01) than the herd average. Fetal membranes were retained after 49 natural parturitions. Pregnancy rates among dams retaining fetal membranes were not significantly altered (82.2 vs 79.4%). A total of 153 calvings was associated with prolapse of the reproductive tract, including 124 (81.0%) vaginal prolapses and 29 (19.0%) uterine prolapses. Subsequent pregnancy rate of all dams experiencing prolapse was lower (p less than .01) than the herd average. Pregnancy rates following prolapse among primiparous and multiparous dams were 28.0 and 57.9%, respectively. These data indicate that caesarean section and vaginal or uterine prolapse result in significant reductions in subsequent pregnancy rates of affected dams, with no detrimental effect on dams retaining fetal membranes.

Animals↗
PubMed1981

Feeding by Actinophrys sol (Protista, Heliozoa): 1 light microscopy.

The feeding behavior of the heliozoon Actinophrys sol was investigated using the ciliate Colpidium colpoda as food. The ciliate is caught by adhesion to the arms of the heliozoon. Within 20 min the prey is enclosed by a funnel-shaped pseudopodium which progresses over the prey by the action of its differentiated leading edge. Independent Actinophrys cells may fuse together during prey capture and the early stages of prey digestion. After prey ingestion, the ciliate is lysed and the contents of the food vacuole coagulate. Much of the fluid is removed from the food vacuole and, within 4 h of feeding, the food vacuole has condensed around its coagulated contents. As food vacuole condensation occurs, the peripheral region of the heliozoon cell becomes vacuolated. The appearance of the cell and of the food vacuole remain the same for about 12 h, after which time the undigested residues in the food vacuoles are egested, fused masses of cells separate as uninucleate cells and nuclear division may occur. During feeding, the extrusomes are greatly depleted. These bodies are implicated in the processes of food capture and in the production of food vacuole membrane.

Animals↗
PubMed1979

On the organization and classification of the protozoon, Actinophrys sol Ehrenberg, 1830.

The organization of the heliozoon Actinophrys sol is described using light-microscopy, transmission and scanning electron-microscopy, freeze fracturing and X-ray microanalysis. The features of the trophic organism and its organelles are described in detail. The processes of encystment, autogamy and excystment are outlined. Encystment involves the production of siliceous scales which are destined to become one layer of a resting cyst with a multilayered cyst wall. Autogamy occurs before the resting cyst is formed. Cytoplasmic peculiarities of the trophic organism are almost entirely absent from the resting cyst but reappear upon excystment. The structural characteristics are used to assess the affinities of Actinophrys with other actinophryids, heliozoons, actinopods and sarcodina. It is concluded that the justification of the conventional classification of Heliozoa is questionable.

Animals↗
PubMed1978

Membranous sacs associated with cilia of Paramecium.

A membranous system associated with the cortical cilia of Paramecium putrinum is described. A sac lies below the cortical kinetosomes and extensions from it pass along the kinetodesmal fibre to lie near, or make contact with, the parsomal sac and also pass deep into the cytoplasm to pass close to a mitochondrion. Because of its widespread occurrence in this and other species it is suggested that the system plays a physiologically active role.

Animals↗
PubMed1976

Behavior of the contractile vacuole of Tetrahymena pyriformis W: a redescription with comments on the terminology.

The behavior of the contractile vacuole of Tetrahymena pyriformis W has been recorded and analyzed quantitatively by cinephotography. The vacuole fills in a stepwise fashion by the confluence of ampullae which appear regularly at the beginning of systole and whose membranes are continuous with that of the contractile vacuole throughout the cycle. The vacuole may subsequently fill slowly by a means not discernible by light microscopy. The vacuole rounds up at the beginning of systole and shortly thereafter the ampullae reappear around the perimeter of the vacuole. They are expanded by fluid forced into them from the vacuole. Round-up and the mode of growth of the ampullae indicate that the contractile vacuole is truly contractile. Expulsion occurs soon after the appearance of the ampullae and terminates the cycle. Contraction is initiated at regular intervals by a timing mechanism which is independent of the size of the vacuole. Suitable terminology to describe the structure and behavior of the contractile vacuole is discussed.

Animals↗
PubMedDate not supplied

Prospective evaluation of a small caliber upper endoscope for colonoscopy after unsuccessful standard examination.

Colonoscopy is unsuccessful in some patients because of a fixed sigmoid loop or anatomical stenoses. We prospectively evaluated 1600 patients undergoing colonoscopy at Virginia Mason Medical Center from December 1, 1986 to November 31, 1987. Thirty-one procedures (1.9%) failed to reach the splenic flexure because of functional or anatomic stenoses. Attempt at pancolonoscopy with a 9.8-mm diameter, 102-cm length endoscope (Olympus XQ) was successful to the right colon in 73% and cecum in 60% of these patients. Two thirds of the successfully intubated patients had clarification of radiographic abnormalities or delineation of additional colon pathology. There were no complications or instrument damages, but limitations included short scope length and small suction channel. We conclude that small diameter upper endoscopes can be used safely and effectively for colonoscopy in a subset of patients in whom conventional colonoscopy is unsuccessful.

Colonic Diseases↗
PubMedDate not supplied

Tube dysfunction following percutaneous endoscopic gastrostomy and jejunostomy.

Percutaneous endoscopic gastrostomy (PEG) and jejunostomy (PEJ) have supplanted their surgical counterparts in many institutions. Previous reports have claimed advantages in placing PEJ tubes because of reduced gastroesophageal reflux, prevention of aspiration, and improved tube anchoring distally. We reviewed the records of 191 patients who underwent placement of PEG/J tubes. Data collected included incidence of tube dysfunction, need for tube replacement or removal, and aspiration after PEG or PEJ tube placement. Tube dysfunction, defined as peritube leakage, plugging, fracture, or migration, occurred in 36% of patients over a mean follow-up period of 275 days and was significantly more common and likely to necessitate tube replacement in PEJ patients. Tube trade-out or removal and aspiration within a 30-day period after tube placement occurred in 28% and 10% of patients, respectively. These complications were significantly more common in PEJ patients than in PEG patients. Because of the increased incidence of tube dysfunction and the failure to prevent aspiration in predisposed patients, PEJ tube placement is not routinely indicated in patients requiring tube feedings.

Enteral Nutrition↗
PubMedDate not supplied

Long-term follow-up in patients who have undergone balloon dilation for gastric outlet obstruction.

Although balloon dilation for gastric outlet obstruction has supplanted vagotomy plus drainage or resective therapy in some institutions, there are no long-term data which demonstrate what percentage of patients ultimately requires surgical intervention. Of 23 evaluable patients treated with hydrostatic balloon dilation in our institution, 70% were asymptomatic at a mean follow-up of 2.5 years. Five patients required surgery--one for acute perforation and the other four for symptoms of continued obstruction, despite one to three additional attempts at dilation. Only three of seven patients with previous gastric resection had a satisfactory long-term result. Whereas endoscopic therapy initially cost one tenth to one fifth that of surgical intervention, such figures do not factor for loss of productivity, on the one hand, or potential need for chronic H2 blockade, on the other. Despite instruction to the contrary, only 6 of 15 (40%) active patients continue acid-suppressive therapy. We conclude that balloon dilation remains a viable alternative for selected patients with gastric outlet obstruction.

Adult↗
PubMedDate not supplied

Metallic self-expanding stent application in the upper gastrointestinal tract: caveats and concerns.

Ten patients with a variety of upper gastrointestinal tract stenoses precluding conventional prostheses or associated with recurrent occlusions of these prostheses, had an expandable metal Z stent placed. All patients had successful insertion (esophagus, five; biliary, three; afferent loop, one; efferent loop, one), although there was a tendency for the prostheses to delivery distally (gut) or proximally (biliary tree). Despite patency rates for up to 6 months in the esophagus and 1 year in the biliary tree, additional data and design modifications are required before widespread utilization.

Catheterization↗
PubMedDate not supplied

Prospective evaluation of costs of disposable accessories in diagnostic and therapeutic ERCP.

Procedural (room fee) reimbursement from insurance payers is usually fixed for individual endoscopic procedures and may not include the costs of disposable equipment. This study estimated costs of disposable items used in ERCP procedures and calculated the percentage of total reimbursement spent on such equipment. A total of 248 ERCPs were performed in a 5-month study period, 192 (77%) of which were therapeutic. Total reimbursement was estimated to be $112,262 ($452 per procedure) and total disposable equipment costs were $47,195 ($190 per procedure), or 42% of total reimbursement. Disposable instrument costs in diagnostic ERCP approximated 13% of those associated with therapeutic ERCP, and the latter costs in turn utilized more than 60% of Medicare/Medicaid room fee reimbursement. This reimbursement may be inadequate to cover both disposable instrument costs and other procedural expenses, such as admit-recovery costs, nursing assistance, expenses related to endoscope purchase and capitalization, and equipment cleaning or sterilization. Our data suggest the need for either re-usable endoscopic accessories or adequate compensation to cover disposable instrument costs.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMedDate not supplied

Endoscopic treatment of biliary injury in the era of laparoscopic cholecystectomy.

During a 2-year period in which the application of laparoscopic cholecystectomy became widespread in the Pacific Northwest, 33 patients with surgically related bile duct injury were seen by the gastroenterology section of a large multi-specialty clinic. Twenty-nine of these patients had anatomy amenable to endoscopic approach, and 25 of the 29 are symptom-free, with normal ultrasonography and serum liver function tests, at a minimum of 1 year of follow-up after undergoing a variety of endotherapeutic procedures. The authors conclude that endoscopic therapy, in conjunction with percutaneous drainage of large bilomas, is effective treatment for cystic duct leak and minor damage to the common bile duct. Further data and prolonged follow-up are required in patients with more significant biliary injury who undergo endoscopic endoprosthesis and/or dilation therapy.

Biliary Fistula↗