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Biomedical subjects

J L West

Publications and source records attributed to J L West.

At least 37 records · Page 2Linked to original sources
PubMed1995

The morbidity of heparin therapy after development of pulmonary embolus in patients undergoing thoracolumbar or lumbar spinal fusion.

STUDY DESIGN: The postoperative course of patients who developed a pulmonary embolus after thoracolumbar or lumbar spinal fusion treated with heparin was studied to quantify the morbidity risk of anticoagulation. OBJECTIVE: To compare the morbidity risk of heparinization with that of an alternative form of therapy--inferior vena cava filter placement. SUMMARY OF BACKGROUND DATA: Therapeutic heparinization was the current treatment of choice for patients who develop thromboembolic disease after surgery. Although heparin usage was reported to be associated with a number of complications after other orthopedic and general surgical procedures, no information was available to identify complications of heparinization after lumbar or thoracolumbar spine surgery or to define the risk of such complications. METHODS: Twenty-two members of the Scoliosis Research Society were polled to determine their experiences with the anticoagulation of this subset of patients. Surgeons polled had a combined experience of 250 man-years and had performed more than 13000 thoracolumbar and lumbar spinal fusions. The MEDLINE database was used to review pertinent English language publications describing inferior vena cava filter complications, effectiveness, safety, and indications for use. RESULTS: Nine patients were located who fit the inclusion criteria of this study. Six (67%) had complications attributable to heparinization. Clinically significant complications of filter placement ranged from 0.12% to 10.1%. CONCLUSIONS: Heparinization after the development of pulmonary embolus in patients recently undergoing spinal fusion is associated with a high complication rate. The morbidity of vena cava filter placement is low and should be considered a treatment alternative in the treatment of patients who experience pulmonary embolus after surgery.

Adolescent↗
PubMed1995

Comparison of covalently and physically cross-linked polyethylene glycol-based hydrogels for the prevention of postoperative adhesions in a rat model.

A covalently and a physicochemically cross-linked hydrogel, both based primarily on polyethylene glycol and both formed in situ, were compared side by side in a rat uterine horn devascularization and serosal injury model for efficacy in adhesion prevention. The primary difference between the two materials was the nature of their cross-linking. The covalently cross-linked hydrogel was a photopolymerized polyethylene glycol-co-lactic acid diacrylate, and the physically cross-linked hydrogel was a polyethylene glycol-co-polypropylene glycol, Poloxamer 407. In the surgical model employed, application of the covalently cross-linked hydrogel reduced the extent of adhesion formation from 75 +/- 10% in the control group to 16 +/- 6% (mean +/- s.d., P < 0.001). Application of the physically cross-linked hydrogel reduced adhesion formation to 38 +/- 19% (P < 0.01). Retention of the two hydrogels upon the site of application was also evaluated. The covalently cross-linked hydrogel formed a continuous barrier upon the uterine horns for more than 4 d, while the physicochemically cross-linked hydrogel was present upon the uterine horns for less than 2 d. This difference in retention was probably the cause of the difference in efficacy and may be attributed to the nature of the cross-linking.

Animals↗
PubMed1994

Management of retroperitoneal chylous leakage.

Lymphatic complications are uncommon after spinal surgery. Postsurgical collections of lymph may result in chyloma, chylothorax, chylous ascites, or chyloretroperitoneum. Recommended treatment of chylothorax or chylous ascites includes drainage, and a low-fat diet using medium-chain triglyceride or total parenteral nutrition. The only reported case of chyloretroperitoneum concluded with a recommendation for retroperitoneal drainage. The authors present a series of three patients who underwent anterior spinal procedures complicated by retroperitoneal lymphatic injury. All three were treated without retroperitoneal drains, and at follow-up, none has shown any adverse sequelae from this method of treatment. The authors disagree with past recommendations for drainage of the retroperitoneal space because this may prolong drainage and deplete nutrition.

Adult↗
PubMed1992

Incidence of deep vein thrombosis in major adult spinal surgery.

Deep vein thrombosis and pulmonary embolus are well known complications of lengthy orthopaedic procedures. Historically spine surgery has been associated with few thrombotic complications. Recent widespread use of instrumentation in adult cases led to concern regarding the incidence of deep vein thrombosis and pulmonary embolus. Forty-one patients underwent posterior spinal procedures using either pedicular or segmental instrumentation. One day before discharge all patients underwent noninvasive testing using color duplex Doppler imaging to rule out deep vein thrombosis. Six patients were noted to have tests results compatible with deep vein thrombosis. The incidence of deep vein thrombosis during this study (14%) reveals a group of patients who would have been discharged with ongoing thrombosis and potential pulmonary embolism.

Adult↗
PubMed1991

Complications of the variable screw plate pedicle screw fixation.

In this study, 124 consecutive cases of posterior spinal fusion with variable screw plate fixation were reviewed. In 33 patients (27%), 41 complications were identified. Urinary tract infection without sequelae developed in 13 patients. Dural tear occurred in seven patients and wound hematoma in five. Wound infection developed in three patients; one was subfascial requiring instrument and graft removal. Neurologic deficit developed in seven patients (6%), in five of whom the deficit was due to manipulation and reduction of neural elements. Two of the seven deficits were believed to be caused by misplaced pedicle screws. Variable screw plate fixation is a formidable procedure with a significant complications rate.

Adult↗
PubMed1991

Infection of P388D1 macrophages and respiratory epithelial cells by Histoplasma capsulatum: selection of avirulent variants and their potential role in persistent histoplasmosis.

We evaluated P388D1 macrophagelike cells as model host cells for studying the intracellular survival and strain-specific virulence of Histoplasma capsulatum. Previously characterized strains which were virulent for mice destroyed monolayers of these cells within a few days. In contrast, related avirulent "smooth" variants failed to do so even after 20 days, although they persisted within P388D1 cells for at least 7 days. On the basis of this observation, we developed a quantitative radiolabel assay to use as an initial screen for virulence. Another cell type lining the respiratory tract was then examined as a potential host for H. capsulatum. Hamster trachea epithelial (HTE) cells readily internalized a variety of strains lacking alpha-(1,3)-glucan in their cell walls; however, the tracheal cells were only rarely infected by organisms possessing this polysaccharide. We subsequently inoculated HTE cells with alpha-(1,3)-glucan-positive strains and enriched for the few yeasts infecting these cells. The progeny resembled smooth variants in terms of colony morphology, the absence of alpha-(1,3)-glucan in their cell walls, and their inability to kill macrophages. Did the HTE cells select for these variant yeasts from the parent inoculum or instigate a change from the parental phenotype? Following a 3-h uptake period, only 2% of the ingested yeasts lacked alpha-(1,3)-glucan. One day later, nearly half of the intracellular organisms lacked this polymer. This rapid conversion of a large proportion of the inoculum suggests some type of environmentally triggered change, perhaps analogous to phase variation seen in many other pathogens. Infection of epithelial cells or some other nonprofessional phagocyte during natural histoplasmosis might give rise to similar variants, thus establishing a reservoir of organisms capable of causing chronic or latent infections.

Animals↗
PubMed1991

Results of spinal arthrodesis with pedicle screw-plate fixation.

Sixty-one patients were followed for an average of thirty months (range, twenty-four to thirty-five months) after arthrodesis of the lumbar or lumbosacral spine with pedicle screw-plate fixation for painful degenerative arthritis, spondylolisthesis, or pseudarthrosis. The patients rated the clinical result according to an analog scale. Most patients reported a marked decrease in pain and an increase in function, and two-thirds were able to work full time. The result of the operation was regarded as a clinical failure if the patient considered it so, if an additional operation had been done, or if the functional and pain scores were not good (that is, if the patient was not able to work full time and the rating for pain was more than 5 of 10 points). Seventeen (28 per cent) of the patients were considered to have a clinical failure, with the lowest rate (20 per cent) for patients who had painful degenerative arthritis and the highest rate (47 per cent) for patients who had had a pseudarthrosis before the operation. The rate of fusion was 90 per cent in patients who had painful degenerative disease, 93 per cent in patients who had spondylolisthesis, and 65 per cent in patients who had had a pseudarthrosis preoperatively.

Adult↗
PubMed1977

Mucormycotic hepatic lesions resembling bacillary hemoglobinuria infarcts in irradiated calves.

To produce hematopoietic chimeras, 3 young, healthy calves were exposed to whole-body irradiation and, 6 days after irradiation, were injected with a bone-marrow suspension prepared from an unrelated, normal donor calf. Antibiotics were administered daily to control bacterial infection. One calf died 8 days postirradiation (PI), another died 10 days PI, and the third calf was killed in extremis 11 days PI. In addition to lesions of acute radiation injury, one to several spherical, firm, dry, reddish-black nodules were found in the liver of each calf. Hepatic changes and blood-stained urine were suggestive of bacillary hemoglobinuria. Fungi, identified by their morphologic features as members of the class Phycomycetes, were widely distributed in the tissues and lesions.

Animals↗
PubMed1976

Acute toxicity of ammonia-base neutral sulfite pulp mill waste liquor to rainbow trout.

The acute toxicity to rainbow trout of untreated ammonia-base neutral sulfite pulp mill waste liquor was demonstrated in these experimants. A mean LC50 of 0.82% and 95% confidence interval of 0.08 - 1.56% was obtained in four static bioassays. Lignin, sulfur dioxide, and ammonia were implicated as toxic components. The latter two were probably the most toxic.

Animals↗
PubMed1975

Ectopic feather follicles in a chicken teratoma or malformation.

At necropsy of an 8-week-old pullet a 0.75 X 5.0 cm. yellowish, moderately firm cigar-shaped object was seen in the greater abdominal air sac lying parallel to the border of the right hepatic lobe. A capsule of 5 tissue layers (from inside outward-stratified squamous epithelium fibrous tissue, longitudinal muslce, fibrous tissue and circular muscle) enclosed featherlike structures which had developed from the stratified squamous epithelial layer. This combination of tissue components constituted ectopic follicles and feathers in a malformation or teratoma.

Air Sacs↗
PubMed1975

Bovine pheochromocytoma: case report and review of literature.

A pheochromocytoma had partially replaced the left adrenal gland of a mature, grade Hereford cow and had penetrated the caval wall with resultant production of an intravascular nodule having a diameter of 2 cm. A few small neoplastic emboli were in thin-walled capsular and trabecular blood vessels. Metastasis to other tissues was not demonstrated.

Adrenal Gland Neoplasms↗