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Biomedical subjects

D L Ward

Publications and source records attributed to D L Ward.

33 records · Page 2Linked to original sources

Treatment of metastatic renal cell carcinoma with recombinant interleukin-2 in combination with vinblastine or lymphokine-activated killer cells.

Fifty patients with metastatic renal cell carcinoma were treated with recombinant interleukin-2 alone or in combination with the antitumor drug vinblastine or lymphokine-activated killer cells. Of 34 evaluable patients treated with intravenous bolus interleukin-2, 1 (3%) had a partial response. Vinblastine increased myelotoxicity but did not enhance response to interleukin-2 in 15 of these patients. Two partial responses were observed among 15 patients treated with lymphokine-activated killer cells in addition to interleukin-2. In 1 patient biopsy documented complete resolution of hepatic metastases lasting for 1 year was observed. All responders had undergone previous nephrectomy and none had multiple sites of metastatic disease. Toxicity was significant and caused termination of therapy in 40% of the patients. Biological therapy using interleukin-2 can result in prolonged responses in renal cell cancer but future trials should be directed at lessening toxicity.

Antineoplastic Combined Chemotherapy Protocols↗

2-(aminoalkyl)-5-nitropyrazolo[3,4,5-kl]acridines, a new class of anticancer agents.

2-(Aminoalkyl)-5-nitropyrazolo[3,4,5-kl]acridines were prepared from substituted anilines via the 1-chloro-4-nitroacridones followed by condensation with [(alkylamino)alkyl]hydrazines. Impressive activity was demonstrated for the 9-hydroxy, 9-alkoxy, and 9-acyloxy analogs in vitro on a L1210 leukemia line and in vivo against the P388 leukemia. Advanced studies led to the selection of 3bbb for clinical trial.

Acridines↗

An international comparison of asthma morbidity and mortality in US soldiers. 1984 to 1988.

Asthma-related morbidity, as measured by hospital discharges, and mortality are compared for US soldiers assigned to central Europe and to the continental United States. The populations, as well as the level and type of medical care available, are quite similar in both locations and permit a purer contrast of the effect of geography than is possible by comparing indigenous populations across national boundaries. The results reveal higher discharge rates and mortality in Europe than in the United States; a peak discharge rate in the third calendar quarter in Europe but less clearly in the United States; similar mortality in black and white subjects, in contrast to US civilian data; and declining discharge rates over time among soldiers less than 24 yr old.

Adult↗

Occupational eye injuries in soldiers.

Soldiers have occupational exposure to eye hazards that in many ways are comparable to those in civilian industry. We conducted a prospective, community based, case-control study at three large troop installations of an infantry division to characterize nonmilitary-unique, occupational eye injuries and associated risk factors and to assess current occupational health practice in eye injury prevention in the division. The findings indicate that the most important risk factors are youth, a history of an eye injury in the preceding two years, and, paradoxically, the perception that supervisors are concerned and well informed about eye injury prevention. Injury severities were mild resulting in an average of 1 day of lost employment per injury. The economic impact for the entire US Army Europe is estimated to approximate $1,100,000 per year.

Accidents, Occupational↗

Conjunctival biopsy in the diagnosis of sarcoidosis.

We prospectively studied 47 sarcoidosis suspects and compared conjunctival and transbronchial lung biopsies in these patients. Thirty-four patients had positive findings on biopsy by either method. The transbronchial biopsy was positive in 31 patients, and the conjunctival was positive in 19. The transbronchial lung biopsy was more likely to be positive in black patients (p = 0.009) and in patients with pulmonary infiltrates on chest x ray (p = 0.0044). In comparison, the conjunctival biopsy was more likely to be positive in patients with conjunctival follicles (p = 0.036), ocular abnormalities consistent with sarcoidosis (p = 0.02), and in patients with pulmonary infiltrates on chest x ray (p = 0.029). Iritis was present in 12 patients, enlarged lacrimal glands in three, and vitritis in five. We conclude that the conjunctival biopsy is an effective means of diagnosing sarcoidosis and that every sarcoidosis patient should have an ophthalmic examination.

Adult↗

Renal oxalate excretion in calcium urolithiasis.

Urinary oxalate was determined in an ambulatory setting in 107 patients with an increased intestinal calcium absorption rate in whom stones formed, 34 patients with normal calcium absorption in whom stones formed and 34 control subjects without stones. Urinary oxalate excretion was not significantly different when the diet was changed from a random to a calcium-restricted diet. Moreover, urinary oxalate was not higher during summer months when intestinal calcium absorption may have been stimulated. Diet history disclosed that many patients with an increased calcium absorption rate had been on a moderate oxalate-restricted diet, often as part of a calcium-restricted regimen for the control of hypercalciuria. The results indicate that renal oxalate excretion in an ambulatory setting is not critically dependent on the state of calcium absorption and intake, and that the imposition of a low calcium dietary regimen in patients with an increased calcium absorption and in whom stones form does not necessarily augment oxalate excretion.

Adult↗

Medical applications in the TANDEM-16 multiple computer system environment.

This paper addresses the question of reliability and the TANDEM-16 approach to facilitate reliable computers. Specifically, the use of the TANDEM-16 within the medical environment is described. Three current applications within the Medical Computing Resources Center at The University of Texas Health Science Center at Dallas are developed, each characterized by different reliability considerations.

Computers↗

Endoscopic balloon dilation of benign esophageal strictures in dogs and cats.

Endoscopic balloon dilation of benign esophageal strictures was performed in 18 dogs and 10 cats with a median age of 4 years. Stricture formation was associated with a recent anesthetic episode in 18 patients. Regurgitation was the most common clinical sign and was present a median of 4 weeks before dilation. Most animals had a single stricture; median diameter was 5 mm, and median length was 1 cm. Esophagitis and mucosal fibrosis were detected in 9 patients each. Dilation was performed with progressively increasing diameter balloons, from 6 to 20 mm. After dilation, mucosal hemorrhage was mild to moderate in most patients. Esophageal perforation was the only serious complication and occurred in 1 patient. Postdilation therapy consisted of administration of cimetidine, metoclopramide, sucralfate, and prednisone in most animals. The median number of dilation procedures performed in each animal was 2, with a range of 1-5. The median interval between dilations was 13 days. Stricture diameter markedly increased with subsequent dilations. Median duration of follow-up was 131 weeks. A successful outcome occurred in 88% of patients, with most animals able to eat canned, mashed, or dry food without regurgitation. Mucosal fibrosis was associated with a better clinical response score, while increasing age was weakly associated with fewer dilations. The dilation protocol used in this group of animals was safe and efficacious.

Age Factors↗

Endostatin and vascular endothelial growth factor concentrations in healthy dogs, dogs with selected neoplasia, and dogs with nonneoplastic diseases.

To evaluate the relationship between endostatin and vascular endothelial growth factor (VEGF) in cancers of dogs, circulating concentrations of these 2 tumor-associated markers were measured prospectively in healthy dogs (n = 44), dogs with tumors (n = 54), and dogs with nonneoplastic diseases (n = 42 for endostatin; n = 16 for VEGF). A canine-directed enzyme-linked immunosorbent assay kit was used for determination of endostatin, and a human-directed kit was validated for detection of canine VEGF. Concentrations of endostatin for all dogs were 28-408 ng/mL. Increasing serum endostatin concentration was associated with increasing age (P = .0396). Concentrations of endostatin were not different among groups of dogs (P = .1989) when adjusted for age. Mean endostatin concentrations for all dogs were higher in dogs (P = .0124) with detectable VEGF concentrations. Endostatin concentrations, when corrected for age, were related to decreasing PCV (P = .032) but not white blood cell count (P = .225) or platelet count (P = .1990). Measurable VEGF (> or = 2.5 pg/mL) was detected in 3 (7.0%) of 43 healthy dogs. Dogs with tumors had detectable VEGF in 24 (44%) of 54 dogs, with concentrations ranging from 2.5-274 pg/mL; only 1 dog with a nonneoplastic disease process had detectable VEGF. VEGF concentrations for all dogs after correcting for age, endostatin, and disease categories were associated with increased white blood cell count (P = .0032) and platelet counts (P = .0064) and decreased PCV (P = .0017). Linkage between increased endostatin and VEGF concentrations suggests that similar factors may influence concentrations of these markers. Further evaluation of endostatin and VEGF associations in dogs with tumors may provide information on the extent and progression of the disease.

Aging↗

Autoimmune thyroid dysfunction induced by interferon-alpha treatment for chronic hepatitis C: screening and monitoring recommendations.

OBJECTIVE: To analyze the proposed mechanisms of action of recombinant interferon-alpha (IFN-a) in causing autoimmune thyroid dysfunction, to identify pretreatment risk factors, and to provide recommendations for screening and monitoring of thyroid dysfunction during IFN-a therapy for chronic hepatitis C. METHODS: Selected publications were reviewed to analyze the proposed mechanisms of autoimmune thyroid disorders. In addition, we examined the interrelationship of the thyroid and the liver, the occurrence of thyroid dysfunction in patients with chronic hepatitis C before and after IFN-a therapy, and the presence or absence of antithyroid antibodies in association with thyroid disease. Case reports were selected to demonstrate various IFN-a-induced thyroid dysfunction. RESULTS: IFN-a induces thyroid dysfunction in 3 to 14% of all treated patients with chronic hepatitis C, leading to hypothyroidism, hyperthyroidism, or thyroiditis. In a few patients, thyroid disease will develop in the absence of antithyroid antibodies, a scenario that suggests a nonimmune-mediated mechanism. More frequently, patients develop antithyroid antibodies, which may progress to overt thyroid dysfunction. Through its immunomodulatory properties, IFN-a seems to act through major histocompatibility complex class I antigens to produce antithyroid antibodies and thyroid disease. CONCLUSION: In patients receiving IFN-a therapy for chronic hepatitis C infection, identifiable risk factors for developing autoimmune thyroid dysfunction are preexisting overt thyroid or autoimmune disease, subclinical thyroid or autoimmune thyroid disease, and female gender. Pretreatment screening is recommended for all patients in whom IFN-a therapy is being considered, and periodic monitoring should be performed during such therapy. Thyroid disease need not be a contraindication to IFN-a therapy; early detection of subclinical or overt thyroid disease may allow uninterrupted continuation of IFN-a treatment.

Adult↗

Endoscopic findings of the gastric antrum and pylorus in horses: 162 cases (1996-2000).

Medical records and endoscopy images were examined for 209 horses that had gastroscopic examinations performed with a 2.5- or 3-m-long endoscope by one of the authors (MJM) during a 4-year period (1996-2000). The antrum and pylorus were viewed in 162 horses, and the duodenum was viewed in 94 horses. Of these 162 horses, the gastric squamous mucosa was seen in 157 horses and 50% or more of the glandular mucosa of the body of the stomach was seen in 156 horses. Erosions or ulcers were seen in the gastric squamous mucosa in 91 (58%) horses. Erosions or ulcers were seen in the glandular mucosa of the body of the stomach in only 8% of the horses. Lesions consisting of erosion or ulceration were seen in the antrum or pylorus in 94 (58%) horses. Lesions consisting of hyperemia and a rough or "bumpy" appearance were seen in the mucosa of the duodenum of 16 horses. An association between the presence of lesions in the squamous mucosa and the presence of lesions in the mucosa of the antrum/pylorus was examined by Fisher's exact test, and the linear association of lesion severity scores between the squamous mucosa and the mucosa of the antrum/pylorus was tested using a Monte Carlo estimate for linear-by-linear association. There was no association (P = .88) between these sites for presence of lesions or lesion severity scores. Similarly, there was no association between scores for the glandular mucosa in the gastric body and those in the antrum/pylorus. Because of the high prevalence of lesions in the antrum and pylorus of the stomachs of adult horses examined in a hospital setting, the entire stomach should be viewed during a gastroscopic examination.

Animals↗