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Biomedical subjects

D F Smith

Publications and source records attributed to D F Smith.

At least 289 records · Page 16Linked to original sources
PubMed1984

Data-base management system on a CT scanner computer: application to teaching file and procedure records.

A prototype relational data-base management system was installed on computed tomographic (CT) scanner computers at two hospitals. This was used to create computerized indices for a teaching file and a record of CT procedures. Several problems commonly encountered when maintaining and using a radiologic teaching file were solved. Interesting cases were easily retrieved for teaching, conferences, or publication because the system permits rapid search on the basis of patient name, identification number, date, diagnosis, special description, or a combination of these data. The procedure record index contains these data as well as administrative and technical data on all CT examinations. These data are entered into the data base semiautomatically. The result is an extensive set of records that is easily accessible and requires a minimum of manpower to maintain.

Computers↗
PubMed1984

Stereopsychopharmacology: past, present and future.

Stereoisomers have been used for more than a century to study the role of three-dimensional (spatial) features in biological processes. Configuration and conformation are spatial features of primary interest for effects of drugs. The role of configuration has been studied mainly by comparing effects of optical isomers (enantiomers), whereas the role of conformation has been investigated primarily using geometrical isomers and semi-rigid molecules. Spatial features have been shown to play a role in many effects of stereoisomers on noradrenergic, dopaminergic, serotonergic, cholinergic, opioid and GABAergic mechanisms. Further information on psychopharmacological effects of stereoisomers may lead to a better understanding of mental disorders and to improvements in drugs used to treat them.

Amphetamine↗
PubMed1984

Bovine intestinal surgery.

A clear understanding of the surgical anatomy of the bovine intestinal tract is the most important factor in determining the degree of success to be achieved in the surgical management of intestinal disorders in cattle. However, bovine intestinal anatomy can be very difficult to comprehend, especially in cattle with intestinal distention and malposition. The abundance of mesenteric and omental fat and the compact nature of the mesentery make manipulation and exteriorization of many parts of the bowel difficult. Therefore, it is important to accurately identify specific surgical landmarks. A good working knowledge of the relevant surgical anatomy increases the level of confidence in one's surgical abilities and makes one more willing to consider surgical intervention in a cow with suspected GI dysfunction.

Animals↗
PubMed1983

Glycolipid-lectin interactions: detection by direct binding of 125I-lectins to thin layer chromatograms.

Glycolipids that bind 125I-labeled lectins are detected by autoradiography after thin layer chromatography of glycolipid standards or crude lipid extracts. Soybean agglutinin, Bandeiraea simplicifolia I isolectins A4 and B4, and Helix pomatia lectin are used to detect corresponding cell surface, glycolipid receptors in human and bovine erythrocytes. When lipid extracts from A and AB erythrocyte stroma are analyzed with Helix pomatia lectin, a polymorphic expression of blood group A glycolipid determinants is detected. The Bandeiraea simplicifolia isolectins react weakly with human erythrocyte glycolipids but bind at least 4 glycolipids in bovine stroma extracts. Soybean agglutinin reacts with glycolipids in all erythrocytes analyzed. This technique extends lectin specificity studies from inhibition analyses in aqueous systems using available, known structures to identification of specific, lectin-binding glycolipids in crude lipid extracts of cell membranes.

ABO Blood-Group System↗
PubMed1983

Stimulation of spinal dopaminergic receptors: differential effects on tail reflexes in rats.

The tail-flick reflex to heat and tail-withdrawal reflex to touch were measured in spinal and intact rats given either apomorphine (0.02-1.75 mumol.kg-1) or dopamine (0.02-1.76 mumol.kg-1) in the lumbar subarachnoid space. In spinal rats both apomorphine and dopamine suppressed thermal tail-flick reflex and enhanced tactile tail-withdrawal response in a dose-dependent way. The effect of apomorphine in spinal rats was counteracted by dopaminergic receptor antagonists (cis-flupenthixol and (+)-butaclamol), but not by their stereoisomers. Phenoxybenzamine, propranolol, methysergide and naloxone failed to counteract the effects of apomorphine on tail-reflex responses in spinal rats. (+)-Butaclamol also counteracted effects of dopamine in spinal rats. Neither apomorphine nor dopamine influenced tail reflexes in intact rats, which suggests that effects of spinal dopaminergic mechanisms on these reflexes are influenced by descending supraspinal pathways.

Animals↗
PubMed1983

Lithium and carbamazepine: effects on learned taste aversion and open field behavior in rats.

Three experiments were done to compare effects of LiCl and carbamazepine (CBZ) on behaviors known to be influenced by LiCl in rats. The first experiment showed acute treatment with either LiCl (0.3-1.5 mmol/kg) or CBZ (0.13-0.42 mmol/kg) to produce a learned taste aversion to saccharin. The second experiment showed short-term treatment (once daily for 5 days) with LiCl (1.5 mmol/kg/day) to suppress open field activity in otherwise untreated rats and to cause a behavioral syndrome when given together with pargyline. In contrast, short-term treatment with CBZ (0.42 mmol/kg/day) failed to influence open field behavior. The third experiment compared effects of LiCl (1.5 mmol/kg) and CBZ given at a dose (1.68 mmol/kg) higher than that used in Experiments 1 and 2. LiCl or CBZ had similar suppressant effects on locomotor activity in otherwise untreated rats, but only LiCl led to a behavioral syndrome in rats given pargyline. The findings suggest that LiCl and CBZ may have some similar mechanisms of action on behavior, as well as some different ones.

Animals↗
PubMed1983

Selection criteria for pediatric critical care transport teams.

The primary goal of an interhospital critical care transport program is to provide quality medical care during transit as close as possible to that available in the receiving ICU. Critically ill pediatric patients are transported between hospitals by a variety of transport teams. The skills possessed by physicians, nurses, respiratory therapists, and paramedics overlap. To determine the criteria for selection of the team members for these patients, we reviewed the medical records of 115 pediatric patients transported to this facility in 1978 and 1979. Patients were categorized by diagnosis, severity of illness at the time of transport, and the monitoring and life support required during transport. Our data indicate the medical transport team members should have skills required for pediatric critical care diagnosis and management including endotracheal intubation and assisted ventilation; insertion of peripheral, central venous, and arterial catheters; fluid and electrolyte therapy; antibiotic therapy; cardiovascular monitoring; and pharmacological life support. The team members should be chosen based on the particular skills needed for a transport with a goal of providing the patient care required on a consistent basis.

Adolescent↗
PubMed1983

Dynamic computed tomography and duplex ultrasonography: adjuncts to arterial portography.

The applications and limitations of contrast enhanced computed tomography (CT) in defining the extrahepatic portal system is discussed in the context of three separate cases in which the CT examination was used as an adjunct to an incomplete arterial portogram examination. Dynamic CT may be useful when excessive contrast dilution precludes the visualization of major venous structures during arterial portography. Real-time/pulsed Doppler ultrasonography is another complementary test but more limited in application than dynamic CT. Patency and flow direction in the proximal splenic vein, portal vein, and hepatic vein can be defined by the ultrasonic technique.

Adult↗
PubMed1983

Dynamic computed tomography and pulsed Doppler ultrasonography in the evaluation of splenorenal shunt patency.

Dynamic computed tomography (CT) and real-time/pulsed Doppler ultrasonography were performed in 13 patients following a distal end-to-side splenorenal shunt (Warren procedure). The results were correlated with angiography. The anastomotic site was demonstrated by CT in all patients. Coincident enhancement of the distal splenic vein and left renal vein as demonstrated by dynamic CT was an accurate predictor of shunt patency. Ultrasound studies were performed using a transsplenic coronal imaging approach. Although the proximal splenic vein and left renal vein could be identified, it was not possible to directly evaluate the anastomotic site in any patients. Dynamic CT evaluation of splenorenal shunts may be a useful technique for monitoring shunt patency during long term follow-up and for evaluating patients who later rebleed.

Adult↗
PubMed1983

Central effects of lithium in rats: lithium levels, body weight and water intake.

Male rats received LiCl for one week either by continuous intracerebroventricular injection from osmotic minipumps or by oral administration in the diet. Control groups received corresponding treatment with NaCl. The intracerebroventricular lithium treatment produced relatively high lithium levels in brain regions (0.6-2.3 mmol/kg) and negligible lithium levels in plasma (less than 0.1 mmol/l) while the oral treatment produced moderate lithium levels in brain regions as well as in blood (0.5-0.9 mmol/kg and 0.5-0.75 mmol/l, respectively). Body weight loss and enhanced water intake occurred in groups given oral lithium treatment as well as in those given lithium via minipumps. The results suggest that administration of lithium by minipumps may be of use to study central actions of lithium.

Administration, Oral↗
PubMed1983

Contrast enhancement technique for dynamic hepatic computed tomographic scanning.

A study comparing precontrast and survey postcontrast dynamic computed tomographic (CT) scanning was performed on 60 patients who had suspected hepatic metastases. An incremental dynamic technique was used during and following a 50-g iodine load administered over two minutes. The survey postcontrast dynamic technique was superior in both sensitivity and contrast differentiation and yielded no known false-negative examinations. No postprocedure renal dysfunction was observed. High-dose contrast-material delivery in conjunction with incremental dynamic CT scanning appears to be the most suitable technique for performing postcontrast hepatic CT examinations.

Diatrizoate↗
PubMed1983

Work in progress: temporal energy hybrid subtraction in intravenous digital subtraction angiography.

A preliminary investigation of the feasibility and practical clinical utility of combined temporal energy (hybrid) subtraction for intravenous digital subtraction angiography (DSA) was performed in 19 selected patients. Studies of carotid, aortic arch, pulmonary, and aortorenal vessels were obtained. Soft-tissue misregistration artifacts were effectively removed with hybrid subtraction. Image integration was used to produce a signal-to-noise ratio equivalent to that of single frame temporal subtraction. Diagnostic improvements were produced in 20% of the examinations. Hybrid subtraction techniques resulted in an average increase of incident radiation dose to the skin of 15%.

Angiography↗
PubMed1983

Dissecting aortic aneurysms: accuracy of computed tomographic diagnosis.

During a three-year period, fifty patients were evaluated for the possibility of dissecting aortic aneurysm using high-resolution computed tomography (CT). The diagnosis of dissection was made if two contrast-medium-filled channels were identified within the aortic lumen. Eighteen patients were diagnosed with CT as having dissecting aortic aneurysms. Eight patients were evaluated postoperatively and five of these patients had persistence of the double channel. Twenty-four patients had no evidence on CT of aortic dissection. Follow-up was obtained in all patients. There were no known false-negative diagnoses and one false-positive diagnosis. High-resolution CT offers an accurate, noninvasive means to evaluate patients for suspected dissecting aortic aneurysms.

Aortic Dissection↗
PubMed1983

Removal of the cecum, including the ileocecocolic junction, and its effects on digestibility in cattle.

The cecum and ileocecocolic junction in each of five 7-month-old Holstein steers were removed. Two steers of the same breed and age were sham-operated. All steers survived and were subjected to a digestibility experiment for 16 weeks. Digestibility of dry matter, neutral-detergent fiber, acid-detergent fiber, and cellulose decreased (P less than 0.05) during postsurgical weeks (PSW) 1 to 4, but not during PSW 16. However, digestibility of protein and hemicellulose was not significantly (P less than 0.07) influenced by the operation. Digestibility of the previously described components was not significantly different from that in 2 sham-operated steers. The mean daily weight gain of the cecectomized steers decreased during PSW 1 to 4; however, it started to increase at PSW 8 so that at PSW 16 it approached preoperative values. The mean daily weight gain of the sham-operated steers also decreased during PSW 1 to 4, but was higher than the preoperative values at PSW 14. The difference in mean daily weight gains between the cecectomized and sham-operated steers was insignificant. The consistency of the feces of the cecectomized steers was loose to watery for a period of about 4 weeks after surgery. At PSW 16, the feces were firm, but not of normal consistency. Feces of the sham-operated steers were loose after surgery, but returned to normal consistency after approximately 7 days. Adhesions developed at the surgical site and involved the ileum, the proximal loop of the ascending colon, and the adjacent mesentery and greater omentum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Abomasal ulcer disease in adult dairy cattle.

In a review of case records of all dairy cattle greater than or equal to 1 year of age admitted to the Veterinary Teaching Hospital of the New York State College of Veterinary Medicine in a 4-year-period, abomasal ulcer disease was diagnosed definitively in 42 (2.17%) of cattle. In 5 additional cattle, abomasal ulcers were secondary to lymphosarcoma. The mortality rate for cattle with confirmed abomasal ulcer disease was 50%. For cattle with ulcers causing severe blood loss or diffuse peritonitis, the mortality rate was 100%. Concurrent disease conditions were present in 76% of cattle with abomasal ulcer disease. Significant associations were observed between month of diagnosis and abomasal ulcer disease, and between lactation status and ulcer disease; however, no association between age and ulcer disease was observed. In 71% of all cattle with confirmed abomasal ulcer disease, at least 1 of the following clinical signs was observed: abdominal pain, melena, or pale mucous membranes. Cattle with ulcers causing severe blood loss typically had tachycardia and were anemic. Cattle with ulcers causing peritonitis had elevated concentrations of leukocytes in the peritoneal fluid. Hypochloremic, metabolic alkalosis was a common finding in cattle with each type of abomasal ulcer disease except those with ulcers causing diffuse peritonitis, when metabolic acidosis occasionally occurred.

Abomasum↗
PubMed1982

Role of 5-HT and NA in spinal dopaminergic analgesia.

Spinal rats and rats with an intact neuraxis given the dopamine (DA) agonist R-apomorphine (0.31-1.75 mumol/kg) in the lumbar subarachnoid space by intrathecal injection were tested 5 and 10 min later for spinal analgesia (increased tail-flick response latency). Apomorphine produced analgesia in spinal rats but not in rats with an intact neuraxis. However, pretreatment of intact rats with the serotonergic (5-HT) receptor antagonist methysergide, the noradrenergic (NA) receptor antagonist phentolamine or the two antagonists together led to a dose-dependent analgesia following apomorphine. Intact rats pretreated with the monoamine depleting drug reserpine, the 5-HT synthesis inhibitor p-chlorophenylalanine (PCPA) or the NA synthesis inhibitor FLA 63 also showed analgesia to apomorphine. On the other hand, pretreatment with the catecholamine depleting agent alpha-methyl-p-tyrosine (AMPT), the beta-adrenergic receptor blocker propranolol or the opioid receptor antagonist naloxone failed to produce DA analgesia. The present findings suggest that both 5-HT and NA descending fiber systems exert tonic inhibitory effects on spinal DA nociceptive processes.

Animals↗
PubMed1982

Stereoselective effect of tranylcypromine enantiomers on brain serotonin.

Brain levels of 5-HT, 5-HIAA and L-tryptophan were measured in reserpinized rats given the enantiomers of tranylcypromine (TCP). (+)-TCP (1.5-30 mg/kg) increased levels of 5-HT, whereas (-)-TCP failed to affect 5-HT levels. (+)-TCP at high dosage (30 mg/kg) decreased brain levels of 5-HIAA, whereas (-)-TCP failed to affect 5-HIAA levels. Neither (+)-TCP nor (-)-TCP influenced brain levels of L-tryptophan. The effects of (+)-TCP on behavior resembled those of drugs which influence 5-HT processes, whereas (-)-TCP failed to produce 5-HT-dependent behaviors. The findings support the notion that TCP enantiomers have stereoselective effects on serotonergic mechanisms.

Animals↗