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Biomedical subjects

D J Waters

Publications and source records attributed to D J Waters.

At least 55 records · Page 3Linked to original sources
PubMed1993

Plasma salicylate concentrations in immature dogs following aspirin administration: comparison with adult dogs.

Aspirin disposition in immature and adult dogs, assessed by plasma salicylate concentrations following single doses of aspirin given orally (p.o.) and intravenously (i.v.), was compared. Using a cross-over design, four immature (12-16-weeks-old) and eight adult (1-2-years-old) dogs were given a single dose of aspirin at 17.5 mg/kg body weight i.v. and a single dose of buffered aspirin at 35 mg/kg body weight p.o. Blood was collected from the jugular vein for 24 h following each dose. A fluorescence polarization immunoassay was used for determination of salicylate in plasma. Significant differences in aspirin disposition were identified between the two groups. Immature dogs had significantly shorter salicylate half-life, lower mean residence time, and more rapid salicylate clearance than adult dogs. The difference in volume of distribution between the two groups was not significantly different. Immature dogs had lower mean (+/- SD) peak plasma salicylate concentrations (64.5 +/- 2.38 mg/L) than adult dogs (95.9 +/- 12.2 mg/L) following a single oral dose of buffered aspirin at 35 mg/kg body weight. Predicted plasma salicylate concentration-time curves were constructed for various aspirin dosage regimens. This analysis showed that the previously recommended buffered aspirin dose for adult dogs of 25 mg/kg body weight p.o. every 8 h would be ineffective in maintaining plasma salicylate concentrations > 50 mg/L in immature dogs.

Administration, Oral↗
PubMed1993

Disseminated malignant histiocytosis in a golden retriever: clinicopathologic, ultrastructural, and immunohistochemical findings.

Diagnosis of malignant histiocytosis (MH), a disorder characterized by systemic proliferation of morphologically atypical histiocytes and their precursors, in an 8-year-old neutered female Golden Retriever was based on light and electron microscopic and immunohistochemical findings. Clinically, the dog presented with unilateral forelimb lameness. Eight days after surgical exploration of a swollen brachium, the dog developed sudden onset of posterior paresis, fecal and urinary incontinence, and a flaccid tail. Necropsy revealed infiltrative and nodular lesions in the right forelimb and regional lymph nodes, thoracic and abdominal cavities, and lumbar epidural space. Gross lesions were not found in the lungs or integument. Histopathologic examination showed infiltrates of atypical histiocytes in skeletal muscle, joint, and regional lymph nodes of the right forelimb; intercostal muscle; lung; liver; spleen; pancreas; kidneys; and spinal dura. Most tumor infiltrates were nodular and composed of loosely aggregated cells that were 10-30 microns in diameter with abundant eosinophilic to foamy cytoplasm, had central or eccentric nuclei, and were periodic acid-Schiff negative. Many binucleated cells, multinucleated giant cells, and mitotic figures were seen. Tumor cells contained phagocytosed erythrocytes, mononuclear cells, and some leukocytes. Ultrastructural features of tumor cells included cytoplasmic lipid droplets, lysosomes, and phagolysosomes. Immunohistochemical studies on paraffin-embedded sections showed positive reactivity to human T-cell Ag (clone UCHL-1) and for lysozyme, alpha-1-antitrypsin, and cathespin B. Polyclonal intracellular immunoglobulin reactivity and lectin binding (peanut, soybean, and wheat germ agglutinins and concanavalin A) were also demonstrated. Criteria for diagnosis of malignant histiocytic tumors and differential diagnosis are discussed.

Animals↗
PubMed1992

Anomalous origin of the left main coronary artery from the right anterior aortic sinus.

Anomalous origin of the left main coronary artery from the right sinus of Valsalva is an uncommon problem, occurring in four distinct patterns. When the left main coronary artery passes between the aorta and the pulmonary trunk, acute myocardial ischemia or sudden death may occur. Angiography is required in establishing a diagnosis. Surgical correction or bypass surgery are sometimes indicated. The authors report two cases of anomalous origin of the left main coronary artery and discuss the anatomic variants, clinical significance, and technical considerations in both diagnosis and management.

Coronary Angiography↗
PubMed1992

Cerebral emboli from the 'stump' of a totally occluded carotid artery: surgical management.

The obstructing thrombus in a totally occluded internal carotid artery may act as a source of cerebral emboli. These emboli traverse the external carotid and ophthalmic arteries and enter the intracranial circulation via retrograde collateral pathways. Surgical treatment can result in complete abatement of symptoms in selected patients. The authors describe internal carotid "stump" syndrome in a 47-year-old man and discuss the options for surgical management.

Carotid Artery, Internal↗
PubMed1992

Acute pulmonary embolectomy with cardiopulmonary bypass support.

Deep venous thrombosis and pulmonary thromboembolism remain major sources of patient morbidity and mortality. The authors present the case of a 55-year-old man with a massive pulmonary embolism and subsequent hemodynamic decompensation who was successfully treated by open pulmonary embolectomy supported with cardiopulmonary bypass. Indications for embolectomy and patient selection as well as technical considerations are discussed.

Cardiopulmonary Bypass↗
PubMed1991

Round atelectasis in a 20-year-old woman.

Round atelectasis is an unusual pulmonary pseudotumor often associated with primary pleural pathologic conditions or pleural effusion. We report the case of a 20-year-old woman who was found to have a large, circular pulmonary lesion demonstrated on both plain chest x-ray film and computed chest tomography. The patient underwent exploratory thoracotomy, at which time this uncommon entity was identified.

Adult↗
PubMed1991

Immobilization increases bone prostaglandin E. Effect of acetylsalicylic acid on disuse osteoporosis studied in dogs.

The effect of acetylsalicylic acid (aspirin) on bone mass and bone prostaglandin E (PGE) in immobilization osteoporosis was studied in 12 growing dogs using a unilateral hind limb cast-fixation model. Osteoporosis was induced by fiberglass-cast immobilization of the right hind limb for 4 weeks, with the left hind limb as a control. Six dogs received buffered aspirin at 25 mg/kg body weight per os every 8 hours; 6 dogs received no treatment. All the dogs were killed after 4 weeks, and bone samples were collected. Bone mineral content of the distal tibial metaphysis was measured by single-photon absorptiometry. In vitro release of PGE from the calcaneus, tibial cortical bone, tibial cancellous bone, and ilium were measured using a specific radioimmunoassay for PGE. Compared with the controls, the casted limb of untreated dogs had half the bone mass and a twofold increase in bone PGE. Aspirin treatment was associated with a 65 percent reduction in bone PGE and a 13 percent bone mass sparing effect. These results provide indirect evidence that PGE plays a role in immobilization osteoporosis.

Absorptiometry, Photon↗
PubMed1990

C-terminal fragments of gp120 and synthetic peptides from five HTLV-III strains: prevalence of antibodies to the HTLV-III-MN isolate in infected individuals.

The immunoreactivity of HTLV-III-infected individuals and virus-inoculated chimpanzees with gp120 synthetic peptides of the HTLV-III gp120 envelope principle neutralizing domain (amino acid 301-324 sequences), derived from the HTLV-III isolates 3B, RF, MN, WMJ2, and SC were determined. Sequential bleeds from an infected lab worker and chimpanzees, both infected with the HTLV-IIIB, were immunoreactive only with the 3B peptide. In contrast, 33 HTLV-III-infected individuals were immunoreactive with the HTLV-III(MN) peptide. Of these 33 individuals, 23 were also immunoreactive with the HTLV-III(SC) peptide, and 18 with the HTLV-III(WMJ2) peptide. The data suggest that HTLV-III strains related to MN are most prevalent among HTLV-III-infected individuals. The binding specificities of goat sera generated against either of these synthetic peptides or the C-terminal fragment of gp120 (PB-1, amino acid 287-467, derived from the HTLV-III isolates 3B, RF, MN, WMJ2, and SC) were also determined. Four different ELISA formats (peptide sera/peptide antigens, peptide sera/PB-1 antigens, PB-1 sera/PB-1 antigens, and PB-1 sera/peptide antigens) were utilized to determine the cross-reactivity patterns of goat sera with the antigens. Goat sera generated against MN and SC sequences (PB-1 proteins, as well as synthetic peptides) were highly cross reactive. Thus, patient sera cross reactivity to multiple strains of the principal neutralizing domain may reflect the antigenic relatedness of the virus isolates rather than multiple infection events or strains generated during disease progression.

Amino Acid Sequence↗
PubMed1989

Challenge of chimpanzees (Pan troglodytes) immunized with human immunodeficiency virus envelope glycoprotein gp120.

The human immunodeficiency virus type 1 (HIV-1), the causative agent of acquired immunodeficiency syndrome, infects humans and chimpanzees. To determine the efficacy of immunization for preventing infection, chimpanzees were immunized with gp120 purified from human T-cell lymphotrophic virus type IIIB (HTLV-IIIB)-infected cell membranes and challenged with the homologous virus, HTLV-IIIB. A challenge stock of HTLV-IIIB was prepared by using unconcentrated HTLV-IIIB produced in H9 cells. The titer of the virus from this stock on human and chimpanzee peripheral blood mononuclear cells and in human lymphoid cell lines was determined; a cell culture infectivity of 10(4) was assigned. All chimpanzees inoculated intravenously with 40 cell culture infectious units or more became infected, as demonstrated by virus isolation and seroconversion. One of two chimpanzees inoculated with 4 cell culture infectious units became infected. Chimpanzees immunized with gp120 formulated in alum developed antibodies which precipitated gp120 and neutralized HTLV-IIIB. Peripheral blood mononuclear cells from gp120-vaccinated and HIV-infected animals showed a significantly greater response in proliferation assays with HIV proteins than did peripheral blood mononuclear cells from nonvaccinated and non-HIV-infected chimpanzees. Two of the gp120-alum-immunized chimpanzees were challenged with virus from the HTLV-IIIB stock. One animal received 400 cell culture infectious units, and one received 40 infectious units. Both animals became infected with HIV, indicating that the immune response elicited by immunization with gp120 formulated in alum was not effective in preventing infection with HIV-1.

Animals↗
PubMed1988

Human T lymphotropic virus type I antibody patterns: evidence of difference by age and risk group.

Detection of human T lymphotropic virus type I (HTLV-I) antibody was assessed on 368 sera from subjects with different clinical features and from different parts of the world. Enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay for purified p24 antibodies (p24-RIA) used as screening tests agreed in 88.7% of the sera. The results from 247 selected sera were compared with western blot (WB). WB was reactive in sera five to 25 times more dilute than the last positive ELISA or p24-RIA, but different WB batches varied in sensitivity. ELISA was more sensitive than p24-RIA, and p24-RIA was more specific than ELISA. Indeterminate WB interpretations were common (25.5%). Most seropositive intravenous drug abusers had unusually strong p24 bands by WB. Among healthy individuals, positive WB reactivity increased with age, whereas indeterminate reactivity declined (P = .034). Thus, more-sensitive and -specific HTLV-I antibody tests are needed.

Adolescent↗
PubMed1988

Molecular analysis of the pyrimidine deoxyribonucleoside kinase gene of wild-type and acyclovir-resistant strains of varicella-zoster virus.

The pyrimidine deoxyribonucleoside kinase (dPK) genes from five wild-type and four acyclovir-resistant varicella-zoster virus (VZV) strains were studied. One of the acyclovir-resistant strains was isolated from a patient receiving chronic acyclovir therapy. Acyclovir-resistant strains expressed the 1.8 kb VZV dPK transcript but lacked dPK activity. To determine the basis for the lack of enzyme activity the dPK gene from each strain was cloned and its DNA sequence determined. The VZV dPK gene was found to be highly conserved among strains, with greater than 99% nucleotide and amino acid homology. Each acyclovir-resistant VZV strain differed from its wild-type parent in only a single amino acid. The dPK genes from the acyclovir-resistant strains contained either point mutations near the putative thymidine-binding site of the enzyme or ones that resulted in the premature termination of protein synthesis. Single point mutations were sufficient to render these strains dPK-negative and highly resistant to acyclovir. The molecular basis for acyclovir resistance at the dPK locus of VZV is similar to that previously noted to render herpes simplex viruses resistant to acyclovir.

Acyclovir↗
PubMed1987

Varicella-zoster virus gpI and herpes simplex virus gE: phosphorylation and Fc binding.

gpI, the predominant varicella-zoster virus (VZV) envelope glycoprotein, was shown to be phosphorylated exclusively on serine and threonine residues, and phosphorylated gpI was detected in isolated virions. In cells infected with herpes simplex virus type 1 (HSV-1), a related neurotropic alpha-herpesvirus, HSV gE, the homolog to VZV gpI, and HSV gB, the homolog to VZV gpII, were also phosphorylated. The phosphate on gB and gE was alkali labile and resistant to endo H, suggesting linkage to serine and/or threonine. Although VZV gpI and HSV gE share sequence homology and similar post-translational modifications, no Fc-binding activity similar to that associated with gE was detected for gpI or any of the VZV glycoproteins.

Herpesvirus 3, Human↗
PubMed1986

Unilateral simultaneous renal angiomyolipoma and oncocytoma.

A 70-year-old woman with simultaneous unilateral renal angiomyolipoma and renal oncocytoma presented to the hospital with syncope and abdominal pain. Diagnostic studies indicated a left renal neoplasm consistent with renal cell carcinoma and a radical nephrectomy was performed. Histological examination of the resected specimen demonstrated the presence of the 2 unusual renal neoplasms.

Adenoma↗