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Biomedical subjects

J Woods

Publications and source records attributed to J Woods.

At least 73 records · Page 4Linked to original sources
PubMed1990

AIDS and the social relations of intravenous drug users.

Gauging the impact of AIDS on intravenous drug users requires analysis of the cultural, political, and racial contexts of American society in which drug use is embedded. Considerable variation in behavior among drug injectors and noninjectors in different cities over time further complicates an understanding of the dynamics of drug use. AIDS has prompted many IV drug users to change their behavior, though not all users have reduced the risks of transmitting HIV infection. While expanded harm-reduction strategies and drug abuse treatment systems may help limit the epidemic's spread, weak federal support, constrained hospital resources, and racial stigma inhibit more direct action needed to stem the negative social and personal consequences of drug use.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Modulation of transferrin receptor expression and function by anti-transferrin receptor antibodies and antibody fragments.

It has been suggested that effects of anti-transferrin receptor antibodies on cell growth and receptor expression are the result of varying degrees of receptor crosslinking by bi- and multivalet binding agents. In order to study this question directly, we have cultured murine lymphoma cells in mono- and divalent fragments from IgG and IgM monoclonal anti-transferrin receptor antibodies and in intact antibodies. The studies presented here demonstrate that effects of antibody binding on transferrin receptor distribution, metabolism, and function depend, at least in part, on antibody valence, and therefore on the degree of crosslinking of receptors by antibody. We found that monovalent antibody fragments did not significantly alter cell growth, receptor surface expression, intracellular localization, or degradation. Diavalent antibody caused a uniform down-regulation of cell-surface receptor expression, which was accompanied by increased degradation only when antibody Fc was present. Normal receptor cycling apparently continued, despite the reduction in surface expression. Culture in multivalent IgM antibody, however, resulted in accumulation of antibody-complexed receptor on the cell surface without internalization and caused profound inhibition of cell growth. Thus, we show two mechanisms by which different degrees of antibody crosslinking can influence transferrin receptor function: by receptor down-regulation and blocking internalization.

Animals↗
PubMed1989

The role of lithotripsy and its side effects.

The relative roles of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy currently are being debated. Both treatment modalities are applicable to most upper urinary tract calculi. However, there are some important distinctions between the 2 techniques. Over-all, extra-corporeal shock wave lithotripsy is associated with significantly lower morbidity than percutaneous nephrostolithotomy but stone-free rates are lower for extracorporeal shock wave lithotripsy than for percutaneous nephrostolithotomy. This difference is slight for kidneys containing minimal stone burden but increases in direct proportion to increasing stone burden. The morbidity of extracorporeal shock wave lithotripsy also increases with increasing stone burden. When applied to the treatment of staghorn calculi the morbidity of both techniques is comparable but the stone-free rates are significantly better with percutaneous nephrostolithotomy. Treatment with extracorporeal shock wave lithotripsy produces changes in the kidney similar to that of renal trauma, consisting primarily of intraparenchymal and perirenal hemorrhage and edema. While the acute effects of extracorporeal shock wave lithotripsy are well tolerated by most patients, the long-term sequela of this form of therapy is not well established. Potential long-term adverse effects reported include loss of renal function, hypertension and an increased rate of new stone occurrence. The effect of shock waves on renal parenchyma in experimental animals is dose-dependent (number of shock waves). Magnetic resonance imaging of patients treated with extracorporeal shock wave lithotripsy demonstrates morphological abnormalities in or around the kidney in 63 to 85 per cent of the cases (average number of shock waves 1,200). Despite these observations the safe limits of extracorporeal shock wave lithotripsy in humans have yet to be established. Further study regarding this issue and the potential long-term adverse effects of extracorporeal shock wave lithotripsy is needed urgently.

Humans↗
PubMed1988

Diagnostic value of liver biopsy in alcoholic liver disease.

Because it remains debatable whether all patients with a clinical diagnosis of alcoholic liver disease should have a liver biopsy to help confirm the diagnosis, we evaluated the diagnostic value of liver biopsy in alcoholic liver disease. Studied were 108 consecutive patients who had a percutaneous liver biopsy for the first time. In all cases the patient's clinical diagnosis recorded before biopsy was compared with the histological diagnosis of an experienced histopathologist. Prebiopsy clinical data (reported alcohol intake, signs of chronic liver disease) and laboratory data (liver function tests, mean corpuscular volume, ferritin, hepatitis B serology) were reviewed. We found that a prebiopsy clinical diagnosis of alcoholic liver disease (n = 35) was confirmed by biopsy in all but one case. The prebiopsy diagnosis of alcoholic liver disease was significantly associated with a histological diagnosis of alcoholic liver disease (specificity 98%, sensitivity 79%). Individually, alcohol intake, signs of chronic liver disease, the alanine aminotransferase (ALT), the aspartate aminotransferase to ALT ratio, and the mean corpuscular volume were significantly associated with a histological diagnosis of alcoholic liver disease. When clinical and laboratory parameters were considered jointly using stepwise logistic regression, only reported alcohol intake and mean corpuscular volume were significant. Liver biopsy may not always be necessary for the identification of that broad group of patients with alcoholic liver disease.

Alanine Transaminase↗
PubMed1988

Human eosinophils have prolonged survival, enhanced functional properties, and become hypodense when exposed to human interleukin 3.

Human eosinophils were cultured in the presence of recombinant human IL-3 for up to 14 d and their biochemical, functional, and density properties were assessed. After 3 d of culture in 10 pM IL-3, eosinophils had a viability of 70% compared with only 10% in enriched medium alone. Neither IL-1 alpha, IL-2, IL-4, tumor necrosis factor, basic fibroblast growth factor, nor platelet-derived growth factor maintained eosinophil viability. The 7- and 14-d survival of the cultured eosinophils was 55 and 53%, respectively. No other cell type, including neutrophils, was present after culture. After 7 d of culture, the normodense eosinophils were converted to hypodense cells as assessed by density centrifugation. Eosinophils exposed to 1,000 pM IL-3 for 30 min or cultured in 10 pM IL-3 for 7 d generated approximately threefold more leukotriene C4 (LTC4) in response to calcium ionophore than freshly isolated cells. Furthermore, whereas freshly isolated eosinophils killed only 14% of the antibody-coated Schistosoma mansoni larvae, these eosinophils killed 54% of the larvae when exposed to 100 pM IL-3. The enhanced helminth cytotoxicity was maintained for 7 d when eosinophils were cultured in the presence of both 10 pM IL-3 and 3T3 fibroblasts, but not when eosinophils were cultured in the presence of IL-3 alone. IL-3 thus maintains the viability of eosinophils in vitro, augments the calcium ionophore-induced generation of LTC4, enhances cytotoxicity against antibody-sensitized helminths, and induces the eosinophils to become hypodense cells. These phenotypic changes in the eosinophil may be advantageous to host defense against helminthic infections but may be disadvantageous in conditions such as allergic disease.

Animals↗
PubMed1988

Surgical alternatives in subcutaneous mastectomy reconstruction.

The approach to subcutaneous mastectomy is presented, with emphasis on individualization of surgical technique. The operation is based on breast size as well as nipple-areolar complex location. Reconstructive alternatives include a mammary prosthesis, tissue expander, and autologous tissue.

Breast↗
PubMed1987

Short-term psychiatric hospitalization of children.

Recent changes in psychiatric practice, fueled in part by national economic trends, have contributed to the increasing use of short-term psychiatric hospitalization for children. The authors discuss specific approaches to treatment planning, milieu therapy, family work, and individual therapy that help maximize a patient's stay on the short-term psychiatric unit for latency-age children at Tulane University Hospital. Data on diagnosis and length of stay of children admitted during the first two years of the unit's operation are presented, and specific attributes of latency development that affect the short-term process are discussed.

Child↗
PubMed1986

Effect of thrombolysis (streptokinase) on left ventricular function during acute myocardial infarction.

One hundred ninety-two consecutive patients with acute myocardial infarction were enrolled in a prospective trial of coronary thrombolysis in which either intracoronary or intravenous streptokinase was administered. First-pass radionuclide ejection fraction (EF) was measured early (within 24 hours of admission) and late (10 to 14 days after admission) to assess changes in left ventricular (LV) function. In 68 patients in whom reperfusion was successful, mean EF increased from 39 +/- 11% early to 47 +/- 13% late. In 36 patients in whom reperfusion was not successful, the mean EF increase was significantly smaller (from 38 +/- 10% to 42 +/- 11%, p less than 0.025). Patients in whom reperfusion was successful were then grouped according to extent of LV functional change. The extent of EF change (delta EF) was not significantly influenced by time to lysis at intervals up to 7 hours (delta EF = 9.1 +/- 10% at 2 to 3 hours, 8.7 +/- 12% at 3 to 4 hours, 10 +/- 10% at 4 to 5 hours, and 7.0 +/- 10% at 5 to 7 hours; difference not significant [NS]), location of the infarct (delta EF = 8.9 +/- 11% for inferior and 5.7 +/- 8.0% for anterior, NS), or presence of Q waves on the initial electrocardiogram (delta EF = 8.8 +/- 11% in patients with and 7.8 +/- 9.9% in patients without Q waves). Only the initial EF was predictive of subsequent EF change.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Blunt chest trauma and suspected aortic rupture: reliability of chest radiograph findings.

The chest radiographs of 86 patients with suspected aortic rupture from blunt chest trauma were reviewed. Seventy-three patients had no evidence of aortic rupture on aortography or surgical exploration, and 13 patients had surgically confirmed rupture. Sixteen radiographic findings were analyzed for sensitivity and specificity in detecting aortic rupture. The following findings were not statistically significant: hemothorax on either side; rib fractures on either side; pneumothorax on either side; lung contusion; widened left paravertebral stripe; and widening of the mediastinum, along with an increased ratio of mediastinal width to chest width. The most helpful findings leading to suspicion of aortic rupture included nasogastric tube or tracheal deviation to the right at the T4 level; depression of the left mainstem bronchus; and loss of the aortic contour or knob and left apical cap. False positives and false negatives occurred with each radiographic sign, indicating that there is no single finding that is absolutely reliable in predicting or excluding significant injury in every patient with suspected aortic rupture. Analysis of combinations of findings found that when the aortic contour and knob are normal and the nasogastric tube and trachea are not deviated, there was no case of aortic rupture in four consecutive years of experience. These four signs can be used to exclude aortic rupture.

Aortic Rupture↗
PubMed1985

Total parenteral nutrition cholestasis: a cause of mechanical biliary obstruction.

In a newborn baby with Hirshsprung's disease obstructive jaundice developed following prolonged parenteral nutrition. At laparotomy, thick inspissated bile was flushed from the biliary tree and prompt resolution of the jaundice followed. To our knowledge, this is the first reported case in which inspissated bile appeared to be a complication of total parenteral nutrition. Mechanical obstruction must be recognized as an extreme in the spectrum of total parenteral nutrition cholestasis.

Anti-Bacterial Agents↗
PubMed1984

Computer-assisted instruction and diagnosis of radiographic findings.

Recent advances in computer technology, including high bit-density storage, digital imaging, and the ability to interface microprocessors with videodisk, create enormous opportunities in the field of medical education. This program, utilizing a personal computer, videodisk, BASIC language, a linked textfile system, and a triangulation approach to the interpretation of radiographs developed by Dr. W. L. Thompson, can enable the user to engage in a user-friendly, dynamic teaching program in radiology, applicable to various levels of expertise. Advantages include a relatively more compact and inexpensive system with rapid access and ease of revision which requires little instruction to the user.

Computer-Assisted Instruction↗
PubMed1984

Mediastinal-width/chest-width ratio in blunt chest trauma: a reappraisal.

The chest radiographs of 54 patients with blunt chest trauma and suspected aortic rupture were reviewed retrospectively. A mediastinal-width/chest-width ratio was calculated at the level of the aortic arch. There were 44 patients without evidence of aortic rupture on aortography or surgical exploration and 10 patients with surgically confirmed aortic rupture. There was no identifiable ratio of significance in distinguishing those with aortic rupture and those without rupture. The mediastinal-width/chest-width ratio is of insufficient sensitivity and specificity in confirming or excluding aortic rupture to be clinically useful.

Adult↗
PubMed1983

Muscarinic cholinergic receptors in the piebald mouse model for Hirschsprung's disease.

The contracted segment of terminal large intestine in both Hirschsprung's disease in humans and in the piebald-lethal strain of mice with congenital megacolon may result from muscarinic cholinergic receptor denervation supersensitivity. This hypothesis was tested by direct binding studies using the muscarinic receptor ligand, tritiated quinuclidinyl benzilate. There were no differences in either the receptor density, dissociation constant, or agonist/antagonist Hill coefficients in the proximal, middle, or distal colon of mice with congenital megacolon as compared with normal littermates. These data do not support the concept of denervation supersensitivity. The data support the suggestion that absence of the inhibitory neurons of the enteric nervous system accounts for the hyperexcitability of the musculature of the aganglionic terminal segment and the obstructive constriction of the segment.

Animals↗
PubMed1981

Immunohistochemical analysis of HLA (A, B, C) antigens in liver disease using a monoclonal antibody.

The distribution of HLA class I antigens was studied in 42 liver biopsies and eight necropsies by an immunoperoxidase technique employing a monoclonal antibody which reacts with the heavy chains of class I (A, B, C) HLA antigens. In normal liver HLA class I antigens could not be detected on hepatocyte cell membranes or cytoplasm; these antigens were present on the cell membrane of bile duct epithelium, on sinusoidal lining cells, fibroblasts, and blood vessel endothelium. However, in all patients with acute alcoholic hepatitis, most cases of primary biliary cirrhosis and some cases of chronic active hepatitis HLA class I antigens were detectable focally or diffusely on the cell membrane of hepatocytes; in two cases of acute viral hepatitis (non-A, non-B) HLA class I antigens were present in granular form in the cytoplasm of all hepatocytes. These findings may be relevant to the prolonged survival of liver allografts in man and other species and in the pathogenesis of some liver diseases.

Antibodies, Monoclonal↗