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Biomedical subjects

D Wood

Publications and source records attributed to D Wood.

At least 181 records · Page 10Linked to original sources

Use of segmental airway lavage to obtain relevant mediators from the lungs of asthmatic and control subjects.

Studies have demonstrated that increased amounts of histamine in the airways of asthmatic patients are associated with increased airway reactivity. However, using routine bronchoalveolar lavage (BAL), histamine can be detected in only a portion of asthmatic subjects and a minority of control populations. To obtain relevant mediators from the airways in higher concentrations by avoiding the dilution inherent with a standard BAL, a technique was developed to lavage isolated airway segments of the human lung that employed a double-lumen bronchoscope and a balloon-tipped catheter. Lavage fluid obtained by this method yielded significantly higher concentrations of histamine than that obtained with routine BAL (asthmatic subjects, 2,403 +/- 633 pg/ml vs 188 +/- 42 pg/ml; rhinitis subjects, 533 +/- 187 pg/ml vs 113 +/- 53 pg/ml; normal subjects, 174 +/- 63 pg/ml vs 11 +/- 11 pg/ml). Similar findings were also noted for prostaglandin D2 (PGD2). Segmental airway lavage also resulted in higher lavage fluid concentrations of LTB, than routine BAL. Segmental airway lavage should help in studying the relationship of mast cell degranulation to airways reactivity in both asthmatic and other study populations.

Adolescent↗

Elevated BAL fluid histamine levels and parenchymal pulmonary disease in rheumatoid arthritis.

To determine the amount of histamine in BAL fluid in subjects with RA and to ascertain if elevated histamine levels were associated with parameters of active pulmonary disease, we measured BAL fluid histamine levels in 31 subjects with RA and 36 normal subjects. The subjects with RA had a significantly greater mean BAL histamine level than the normal subjects, (313 +/- 154 pg/ml vs 18 +/- 8 pg/ml; p less than 0.05). When the subjects with RA were divided into three groups based on chest radiograms (1 = normal; 2 = pleural disease only; 3 = interstitial or nodular disease), we found that subjects in group 3 had significantly lower values for TLC and D. Subjects in group 3 also had higher percentages of BAL neutrophils and eosinophils and higher BAL histamine levels (group 1, 115 +/- 52 pg/ml; group 2, 30 +/- 30 pg/ml; and group 3, 1,182 +/- 709 pg of histamine per milliliter). Moreover, BAL histamine levels were negatively correlated with TLC (r = -0.46; p = 0.01) and FVC (r = -0.45; p = 0.01) and positively correlated with BAL neutrophils (r = 0.6; p = 0.0003) and BAL eosinophils (r = 0.89; p = 0.0001). These data suggest that the BAL histamine level may be a useful marker to determine the activity of pulmonary disease in RA.

Arthritis, Rheumatoid↗

Mini-laparoscopy in blunt abdominal trauma.

Blunt abdominal trauma in multiorgan injured or comatose patients always presents a problem. The aim is to assess, in the shortest period of time, which organ injury requires priority and whether intra-abdominal bleeding or perforation exists. Abdominal lavage proved to be too sensitive. Not every positive case needs exploration. Approximately 15%-20% of the cases explored because of positive lavage did not show a significant bleeding site that would require surgical treatment. The authors developed a mini-laparoscope that can be used at the bedside, in the emergency room, or in the intensive care unit. The procedure can be performed with intravenous sedation and local anesthesia. In 150 cases, no hemoperitoneum was found in 53% of these cases. Except for 1, none of these patients needed further exploration. In 21%, severe hemoperitoneum was discovered; these patients were transferred to the operating room, and this was confirmed by surgery. In 26%, a small amount of blood was found in the gutters. These patients were observed in the intensive care unit and an unnecessary exploration was avoided. Laparoscopy gives a wider range of decision making by observing the abdominal cavity. It can be completed in 10-20 min at the bedside. No serious complications were encountered. This procedure should be taught and practiced in trauma centers.

Abdominal Injuries↗

Biologic response (antiviral) to recombinant human interferon alpha 2a as a function of dose and route of administration in healthy volunteers.

The kinetics of the antiviral effect of intramuscular and intravenous injections of recombinant human interferon alpha 2a were investigated in healthy volunteers. Cohorts of eight to 11 subjects received single intramuscular injections of either 0.3 X 10(6), 3 X 10(6), or 18 X 10(6) U or an intravenous infusion of 18 X 10(6) U over 30 minutes. Serial samples of peripheral blood mononuclear cells were analyzed for antiviral effects including both (2'-5') oligoadenylate synthetase activity and resistance to vesicular stomatitis virus infection in vitro. A dose-response relationship was established between recombinant human interferon alpha 2a dose and both vesicular stomatitis virus resistance and (2'-5') oligoadenylate synthetase activity. At the 0.3 X 10(6) U dose an antiviral effect occurred without clinical side effects. The presence of clinical side effects is not necessary for an antiviral effect.

2',5'-Oligoadenylate Synthetase↗

A simple method for determining physiologically active calcium and magnesium concentrations in critically ill patients.

Total serum calcium and magnesium concentrations are frequently abnormal in critically ill patients despite the occurrence of normal ionized levels. Since ultrafilterable calcium and magnesium values approximate ionized levels, we evaluated the accuracy of ultrafilterable levels in critically ill patients. Ultrafilterable serum calcium concentrations were sensitive (95%) and specific (93%) in predicting ionized hypocalcemia. Total serum calcium values were sensitive (93%) but lacked specificity (50%) in predicting ionized hypocalcemia. Total serum magnesium concentrations were sensitive (100%) but not specific (73%) in predicting ultrafilterable hypomagnesemia. We conclude that ultrafilterable calcium concentrations offer an alternative to ionized calcium measurements when an ion-selective electrode is not available. In addition, ultrafilterable magnesium levels may reflect more accurately the true ionized magnesium concentrations than total serum magnesium values.

Calcium↗

Tibial fractures in head-injured children.

Twenty-nine tibia fractures in 28 pediatric patients with head injuries were reviewed for mechanism of injury, age, time to healing, deformity, and functional ability. The most frequent cause was auto versus pedestrian accidents and the average patient age was ten years. Most had major associated injuries. Fractures of the middle third of the tibia comprised 75% of the group and healed after 20 weeks. There were few deformities in this group despite the fact that most were treated by closed methods.

Accidents, Traffic↗

Biophysical characterization of rotavirus particles containing rearranged genomes.

Human rotaviruses containing rearranged genomes were found to package up to 1,800 additional base pairs in virus particles. The viruses compared were indistinguishable in respect of their particle diameters and their apparent S values. Particles containing rearranged genomes were found to be of a higher density than rotavirus particles containing a standard genome as determined by equilibrium density ultracentrifugation. The increase in density was directly proportional to the number of additionally packaged base pairs.

Biophysical Phenomena↗

Heterogeneity of genome rearrangements in rotaviruses isolated from a chronically infected immunodeficient child.

Rotaviruses with genome rearrangements, isolated from a chronically infected immunodeficient child, were adapted to growth in BSC-1 cells. Preparations of viral RNA from fecal extracts showed a mixed atypical rotavirus RNA profile, which was due to the presence of at least 12 subpopulations of viruses grossly differing in genotype. Besides various forms of genome rearrangements involving segment 8-, 10-, and 11-specific sequences, reassortment in vivo was likely to have occurred during the emergence of these viruses. The protein products of viral genomes with various forms of segmental rearrangements seemed to be largely unaltered. Genome rearrangement is proposed to be a third mechanism directing the evolution of rotaviruses.

Animals↗

Immunohistochemical identification of lung cells responsive to beta-stimulation with a rise in cAMP.

To identify specific lung cells possessing functional beta-adrenergic receptors, we developed an immunoperoxidase-staining procedure capable of in situ localization of cells responding to beta-agonist stimulation with a rise in adenosine 3',5'-cyclic monophosphate (cAMP). Isoproterenol was instilled into the airways of excised intact guinea pig lungs for 5 min and resulted in a six to eightfold rise in cAMP. Immediately thereafter, the lungs were washed in and fixed with 10% buffered Formalin. Sections were then stained using immunoperoxidase techniques and monoclonal antibodies directed against cAMP. We found that isoproterenol-stimulated lungs had widespread increased staining for immunoreactive cAMP. The specific cells consistently demonstrating marked increases in staining were airway epithelial cells, airway smooth muscle cells, alveolar and parenchymal macrophages, and alveolar lining cells, including both type I and type II cells, and capillary endothelial cells. Of all tissues, the airway epithelium was the most intensely stained area for beta-agonist-induced immunoreactive cAMP. The techniques employed herein should make possible the in situ localization of cells responding to any stimuli capable of increasing cAMP, thereby allowing the specific identification of cells possessing functional adenylate cyclase-linked receptors.

1-Methyl-3-isobutylxanthine↗

Elevated bronchoalveolar lavage fluid histamine levels in allergic asthmatics are associated with methacholine bronchial hyperresponsiveness.

Using a sensitive single isotope enzymatic assay we measured bronchoalveolar lavage (BAL) fluid histamine in asymptomatic normal (nonallergic), allergic rhinitic, and allergic asthmatic subjects. Normal subjects were found to have little or no detectable amounts of histamine in BAL fluid (11 +/- 11 pg/ml), and few BAL fluid mast cells. In comparison, the allergic rhinitics and allergic asthmatics had much higher amounts of BAL fluid histamine (113 +/- 53 and 188 +/- 42 pg/ml, respectively), and a significantly greater number of BAL fluid mast cells. Furthermore, despite having equivalent baseline pulmonary function values, allergic asthmatics with BAL fluid histamine levels greater than 100 pg/ml required only 7 +/- 2 breath units of methacholine to induce a 20% drop in forced expiratory volume in 1 s (FEV1) (PD20FEV1) while asthmatics with BAL fluid histamine levels less than 100 pg/ml required 49 +/- 19 breath units (P less than 0.05). These data suggest that allergic asthmatics have ongoing lung mast cell degranulation that might contribute to the etiology of airway hyperresponsiveness.

Adolescent↗

Direct evidence of a role for mast cells in the pathogenesis of antigen-induced bronchoconstriction.

We measured bronchoalveolar lavage (BAL) fluid histamine levels in allergic asthmatics and nonallergic normal subjects after local airway antigen and cold 22 degrees C normal saline challenges. Immediately after instillation of antigen through a bronchoscope wedged into a subsegmental airway, all 17 allergic asthmatics but none of the nine normal subjects had visible airway constriction. The asthmatics had a concomitant mean increase in BAL histamine of 23% (P = 0.005), whereas the normals had no change in BAL histamine. Among the allergic asthmatics, the change in BAL histamine content in response to antigen directly correlated with the control (baseline) BAL histamine content (r = 0.66, P = 0.003). Moreover, asthmatics with large antigen-induced changes in BAL histamine had greater airway methacholine sensitivity than did asthmatics without measurable increases in BAL histamine (8 +/- 2 vs. 41 +/- 31 breath units). Neither asthmatics nor normal subjects had airway constriction or changes in BAL histamine levels in response to nonspecific challenge with cold saline. Our data suggest that when allergic asthmatics are exposed to relevant antigens they have in vivo lung mast cell degranulation which results in airway constriction and contributes to nonspecific airway hyperresponsiveness.

Adult↗

A simplified thin-layer chromatography system for the detection of commonly abused basic drugs.

A simple method for the detection of drugs of abuse and their metabolites in urine is described. By extraction of urine (20 mL) with a buffered ToxElut solid phase column all the commonly abused opioid drugs can be detected on a single thin-layer chromatography plate. Location of the spots is achieved by spraying the plate with iodoplatinate following acidification with dilute sulphuric acid. Sensitivity of the order of 1 mg/L is attained for most drugs.

Chromatography, Thin Layer↗

Anisoylated plasminogen streptokinase activator complex versus placebo. A preliminary multicentre study of safety and early mortality in acute myocardial infarction.

90 patients were enrolled into this preliminary multicentre study of the efficacy and safety of 30 units intravenous anisoylated plasminogen streptokinase activator complex (APSAC) compared with placebo in patients with acute myocardial infarction. 45 patients received APSAC and 45 placebo; the groups were similar for age, weight and site of infarction. There were significantly more women treated with APSAC (p less than 0.02). The mean time to treatment was 3.3 hours after symptoms of myocardial infarction for APSAC and 3 hours for placebo. The 30-day mortality was 7 patients in the placebo group and 1 in the APSAC group (p = 0.058). Adverse events were generally minor and were of similar overall frequency in both groups. There were more haemorrhagic events with APSAC, from which all patients recovered, and more cardiovascular events with placebo including 2 deaths from cardiogenic shock. APSAC showed a trend towards a reduction in 30-day mortality. Experience from this study has led to the initiation of the APSAC in myocardial infarction multicentre mortality study (AIMS).

Anistreplase↗

Congenital heart block detected in utero. A case report.

Fetal heart movement and fetal heart rate are easily observed with real-time ultrasonography. Certain aspects of fetal cardiac disorders can thus be further evaluated by M-mode echocardiography. Congenital heart block and associated connective tissue disorders are discussed.

Adult↗