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Biomedical subjects

J A Long

Publications and source records attributed to J A Long.

At least 19 recordsLinked to original sources
PubMed1995

Survival of fecal microorganisms in marine and freshwater sediments.

The survival of culturable fecal coliforms, fecal streptococci, and Clostridium perfringens spores in freshwater and marine sediments from sites near sewage outfalls was studied. In laboratory studies, the inhibition of protozoan predators with cycloheximide allowed the fecal coliforms to grow in the sediment whereas the presence of predators resulted in a net die-off. C. perfringens spores did not appear either to be affected by predators or to die off throughout the duration of the experiments (28 days). Studies using in situ membrane diffusion chambers showed that, with the exception of C. perfringens, die-off of the test organisms to 10% of their initial numbers occurred in both marine and freshwater sediments within 85 days. The usual exponential decay model could not be applied to the sediment survival data, with the exception of the data for fecal streptococci. It was concluded that application of the usual decay model to the fecal coliform data was confounded by the complex relationship between growth and predation. The survival of seeded Escherichia coli in marine sediment was studied by using an enumeration method which detected viable but nonculturable bacteria. Throughout the duration of the experiment (68 days), the same proportion of E. coli organisms remained culturable, suggesting that sediment provides a favorable, nonstarvation environment for the bacteria.

Animals↗
PubMed1990

Hypoglobus following orbital decompression for dysthyroid ophthalmopathy.

Hypoglobus following orbital decompression is not a rare complication. Hypoglobus requiring surgery to elevate the globe following orbital decompression is considered clinically significant hypoglobus. A retrospective analysis of 157 consecutive patients who had their orbits expanded by removing the medial wall and floor of the orbit found seven patients (4.5%) who required further surgery to elevate the globe. The seven patients who developed clinically significant hypoglobus following orbital decompression all developed a set of distinct clinical signs. These included a "setting sun" appearance of the globe, eyelid malposition, orbital volume loss, and strabismus. These clinical signs can be explained by the inferior movement of the globe and the orbital contents following the loss of support structures on the orbital floor. A two-wall orbital decompression performed on a cadaver reproduced the physical signs of hypoglobus. The dissection suggested that the periorbita is the most important structure supporting the globe in the orbit.

Exophthalmos↗
PubMed1989

The 5'region of the rat phosphoenolpyruvate carboxykinase gene confers pH sensitivity to chimeric genes expressed in renal and liver cell lines capable of expressing PEPCK.

The 5' flanking regions of the rat phosphoenolpyruvate carboxykinase gene were used to form chimeric gene constructs with the human growth hormone gene. These constructs were transfected into several renal and one liver cell line and the production of growth hormone (HGH) measured by immunoassay. Cyclic-AMP and glucocorticoid responsiveness of HGH production was observed in all cell lines. In two lines, the rat NRK52E renal epithelial line and the rat H4IIE hepatoma cell line, both capable of expressing PEPCK, lowering extracellular pH increased HGH production several fold. Comparison of hormone and pH effect on cells transfected with a thymidine kinase promoter-HGH chimera indicated that the PEPCK 5' flanking region effects were specific. Thus, part of the pH responsiveness of the PEPCK gene in vivo may be attributed to properties of the 5' flanking regions.

Animals↗
PubMed1989

Transconjunctival lower eyelid blepharoplasty. Technique and complications.

The transconjunctival lower eyelid blepharoplasty is extremely effective at reducing lower lid fullness due to prominent orbital fat. The authors performed 122 consecutive transconjunctival blepharoplasties over a 24-month period. Four patients had skin excision via the pinch technique in conjunction with the transconjunctival fat excision. The main complication was under excision of fat which occurred in nine patients (7.4%). Moderate postoperative wound hemorrhage without hematoma formation occurred in one patient (0.8%). There were no cases of lid retraction, ectropion, entropion, inferior oblique palsy, or over excision of fat. The main advantage of this technique is that it avoids the most common complication of transcutaneous lower eyelid blepharoplasty, namely lower eyelid retraction.

Adipose Tissue↗
PubMed1988

Balloon dilatation of postoperative tracheal stenosis.

Three patients who had previously undergone linear augmentation tracheoplasty developed postoperative stenosis within the grafted segment. In each patient, balloon catheter dilatation successfully enlarged the stenotic airway obviating secondary reconstruction in two.

Adolescent↗
PubMed1988

Pancreatitis in childhood. Experience with 49 patients.

Pancreatitis in children is not common but can be associated with severe morbidity rates. We have treated 49 children with pancreatitis over the past 12 years ranging in age from 1 month to 18 years. One third of the patients had biliary tract disease as an etiology, with nearly half of these being related to underlying hematologic disease, usually sickle cell anemia. Another third of the pancreatitis was due to trauma, and one third of these were related to child abuse. Other etiologies were systemic disease (6 patients), congenital anomalies (8 patients), and idiopathic (3 cases). Eighty-two per cent of the patients presented with abdominal pain, but four children, all less than 4 years old, presented with an abdominal mass. Twenty-nine patients required 33 operations for pancreatitis. Fifteen of the 16 patients with biliary tract disease and all patients with congenital anomalies required operation. Six of the 16 patients with trauma required operation and none of those with systemic disease. As in adults ultrasonographic examination and CT scan are most important in the diagnosis; medical treatment consists of intravenous (I.V.) fluids, nasogastric suction, and total parenteral nutrition (TPN), and risk factors can help predict the severity of the disease while amylase alone is not related to severity. Different from adults, in children an etiology can usually be determined. The common etiologies, biliary tract disease, trauma, and congenital anomalies frequently require operation.

Adolescent↗
PubMed1988

Vision therapy.

Explore the source record for details and available documents.

Child↗
PubMed1988

A method of monocanalicular silicone intubation.

A method for silicone intubation of a single canaliculus is described. A lacrimal stent has been crafted from a short segment of silicone tubing and a punctal plug. The distal end of the stent is fixed in the punctum with a punctal plug. The silicone stent, which is attached to the punctal plug, bridges the canalicular laceration. Because the punctal plug remains fixed in the punctum, no sutures are needed to fixate the stent to the eyelid.

Aged↗
PubMed1984

Diabetic retinopathy. Assessment of severity and progression.

This study describes a classification of overall retinopathy severity based on the presence and severity of lesions graded in the Airlie House classification of diabetic retinopathy, and demonstrates its use in assessing progression of retinopathy over a 6-year period in a group of insulin-taking patients. One hundred and ninety-one insulin-taking patients with diabetes of at least 5 years' duration were identified from their doctors' records in 1970-1971. Patients were seen again in 1972-1973 and 1976-1977. Stereoscopic color fundus photographs of 7 fields in each eye were taken at each visit. All photos were graded using a modification of the Airlie House classification, which specified 6 levels of retinopathy for a given eye; when both eyes are considered an 11-step grading scheme results. Of all patients seen at the 2-year visit whose retinopathy was at risk of progressing, 41.2% showed progression of one level or more on the scale, 19.2% progression of two or more levels. At the 6-year examination comparable rates were 75.0% and 58.4%. Of patients whose retinopathy was level 4 in each eye (nonproliferative retinopathy of "moderate" severity) at the baseline visit, 13/21 (72%) had progressed to proliferative retinopathy in at least one eye at the 6-year examination. The classification scheme proposed appears useful for characterizing overall retinopathy severity of patients on the basis of gradings of fundus photographs. The data presented may be of help in planning trials of treatment aimed at slowing the development or progression of retinopathy.

Adolescent↗
PubMed1984

Prostaglandin production and platelet reactivity of small-diameter grafts.

This article examines the relationship of platelet deposition to thromboxane and prostacyclin (PGI2) production in arterial autografts (n = 8), para-anastomotic native artery (n = 40), nonseeded control (n = 6), and endothelial cell-seeded (n = 17) small-diameter Dacron grafts implanted in the carotid and femoral arteries of dogs. Platelet deposition was measured by a dual-isotope subtraction platelet-imaging technique that expresses platelet deposition as percent indium excess (%IE). PGI2 and thromboxane assays were performed with the use of an immunoreactive assay. The %IE in the nonseeded grafts was significantly higher than in the seeded prostheses (p less than 0.001). Arterial autografts accumulated significantly less platelets than did seeded grafts (p less than 0.05) or nonseeded grafts (p less than 0.001). The thromboxane A2 (TXA2) production in nonseeded grafts was significantly higher than in seeded grafts (p less than 0.001), arterial autografts (p less than 0.001), or in para-anastomotic native artery (p less than 0.001). The PGI2 production by the arterial autografts was significantly higher than by the nonseeded grafts (p less than 0.005), seeded grafts (p less than 0.001), or para-anastomotic native artery (p less than 0.025). The PGF1 alpha/TXB2 ratio was significantly higher in the arterial autografts when compared with the nonseeded grafts (p less than 0.001), endothelial cell-seeded grafts (p less than 0.001), or para-anastomotic native artery (p less than 0.025). We conclude that platelet deposition can be significantly decreased by endothelial cell seeding of small-diameter grafts. The transmural production of TXA2 by native arteries and prosthetic grafts may have an important influence on platelet deposition and patency.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Influence of endothelial cell seeding on platelet deposition and patency in small-diameter Dacron arterial grafts.

Serial platelet deposition, surface topography, and patency were evaluated in control (N = 28) and endothelial cell-seeded (N = 28) small-diameter (4 mm inner diameter) USCI Dacron grafts implanted in the carotid and femoral arteries of dogs. All dogs received aspirin (325 mg) daily for 2 weeks starting 24 hours prior to graft implantation. Endothelial cell seeding was performed by mixing suspensions of autologous endothelial cells that had been enzymatically harvested from segments of external jugular vein with blood that was used to preclot the prostheses. The platelet deposition on each graft was quantitated by means of indium 111-labeled platelets and technetium 99m-labeled red cells in a dual-isotope platelet-imaging technique. Platelet deposition on seeded grafts 24 hours after implantation was significantly higher than on the controls (p less than 0.05). Two weeks after implantation platelet deposition on seeded prostheses had decreased to a level significantly lower than that on the controls and continued to decline on serial studies up to 7 months. In contrast to seeded grafts, platelet accumulation on control grafts dramatically increased after the withdrawal of aspirin therapy and was associated with a sharp rise in control graft thromboses. Gross and scanning electron microscopic evaluation of endothelial cell-seeded grafts after 1 month indicated complete neointimal coverage, whereas none of the control grafts explanted at 1 month or later exhibited a continuous neointimal lining. Cumulative 7-month patency for seeded prostheses was significantly higher than for the controls (96% and 29%, respectively; p less than 0.001). We conclude that endothelial cell seeding in combination with short-term aspirin therapy is a simple, reliable diameter Dacron prostheses. Abrupt withdrawal of aspirin therapy may be contraindicated in nonseeded control grafts because it results in increased platelet deposition and thrombosis.

Animals↗
PubMed1982

CT findings in Addison's disease.

The computed tomographic findings in five patients with depleted adrenal cortical reserve were evaluated. A single patient with idiopathic adrenal atrophy revealed small adrenal remnants bilaterally. Three patients with tuberculosis demonstrated dense calcification in one or both adrenal beds without evidence of normal glandular remnants. On patient and active histoplasmosis showed enlarged nonhomogeneous glands of normal contour, a possible clue in distinguishing acute granulomatous adrenalitis from primary or secondary intraadrenal tumors.

Addison Disease↗
PubMed1981

Radiographic contribution to diagnosis and treatment of complications from peritoneoscopy.

Peritoneoscopy is a valuable nonsurgical procedure for evaluating patients with malignant disease. Directed biopsies of suspected tumor masses may be obtained, and peritoneoscopy can frequently obviate the need for laparotomy. Although the complication rate is low, the radiologist must be aware of potential problems. Radiologists may participate not only in the diagnosis and localization of these complications but also in their therapy by interventional techniques. The radiographic findings in four patients with complications of peritoneoscopy are presented.

Adult↗
PubMed1981

Hepatocellular adenoma in a young woman with beta-thalassemia and secondary iron overload.

The occurrence of a hepatocellular adenoma is described in a young woman with beta-thalassemia and secondary iron overload. This patient had no history of oral contraceptive use, and in fact was hypogonadal as a result of iron deposition in pituitary and gonadal tissue. Although hepatocellular carcinoma frequently occurs in diseases associated with iron overload, this is the first report of a benign liver tumor associated with secondary iron overload.

Adolescent↗