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Biomedical subjects

D Bergman

Publications and source records attributed to D Bergman.

At least 19 recordsLinked to original sources
PubMed2004

Burn injuries in children with attention-deficit/hyperactivity disorder.

PURPOSE: Children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for traumatic injury than non-ADHD-children. Burn injuries in ADHD-children have not been studied. This study was conducted to determine differences in burn injuries between these groups. METHODS: The charts of all children ages 5-18, admitted over a 7-year period to a single regional pediatric burn center, were reviewed. ADHD-children were compared to non-ADHD-children regarding age and gender, type and extent of burn, and burn injury outcome. FINDINGS: There were 278 children included, 35 (13%) having ADHD. ADHD-children were more likely male but did not differ in age compared to non-ADHD-children. ADHD-children were more likely to experience a thermal rather than flame burn (83% versus 58% thermal, P < 0.01) and had more extensive burn injury (10% versus 5% median TBSA, P = 0.03). The ADHD group had a longer length of stay (11 versus 7 days, P = 0.05) and was less likely to be discharged to home (86% versus 93%, P = 0.17). CONCLUSIONS: ADHD-children do differ from non-ADHD-children in their pattern and extent of burn injury. The impulsivity and vigilance deficits that characterize ADHD may place these children at higher risk for specific types of burn injuries.

Adolescent↗
PubMed2001

A normal variant on Tl-201 and Tc-99m MIBI whole-body imaging: the superior right atrial wall (auricle) and superoanterior right ventricular wall are often seen as mediastinal lesions.

PURPOSE: The authors have often observed on Tl-201 and Tc-99m sestamibi (MIBI) scans in patients with thyroid cancer a small focus of increased uptake in the right midparasternal region (focus A) or sometimes in the lower mid chest at the level of the lower sternum (focus B) just inferomedial to focus A. The objective of this study was to assess the frequency of this finding on Tl-201 MIBI studies, to assess the incidence of true pathologic lesions corresponding to these foci, and to identify their nature. MATERIALS AND METHODS: One hundred ten whole body Tl-201 studies using 4 mCi (148 MBq) and 84 MIBI studies using 20 mCi (740 MBq: first-pass, planar, and SPECT images) were reviewed. The appearance of either focus A or focus B on three orthogonal SPECT images was correlated with an atlas of cross-sectional anatomy and computed tomography. If focus A was seen on the immediate static image (obtained at the end of the first-pass acquisition without moving the patient), this image was coregistered with a selected image from the first-pass study showing the superior vena cava and also with another selected image showing the ascending aorta. RESULTS: Focus A was seen in 40% of Tl-201 scans and in 49% of MIBI scans, whereas focus B was seen in 20% of Tl-201 scans and 39% of MIBI scans. On correlation of the SPECT images with a cross-sectional anatomy atlas, focus A and focus B invariably corresponded to the superior portion of the right auricle and basal superoanterior right ventricular wall, respectively. These myocardial regions are prominent and sometimes appear as discrete foci because they are considerably thicker than other parts of the right atrial and right ventricular muscle, respectively, and because they are seen partly end-on in the anterior projection. CONCLUSIONS: The superior portion of the right auricle and basal superoanterior right ventricular myocardium often appear as isolated foci on whole-body Tl-201 and MIBl scans. Neither focus should be interpreted as a metastatic lesion in patients with possible cancer or as an ectopic parathyroid adenoma in patients with hyperparathyroid disease.

Adolescent↗
PubMed2000

Nitric oxide synthase inhibition augments acute allergic reactions in the pig airways in vivo.

The aim of this study was to examine the effects of nitric oxide synthase inhibition on antigen- and histamine-induced acute airway reactions, in order to clarify the possible modulating role of NO. Twelve specific-pathogen-free pigs (sensitized with Ascaris suum antigen) were challenged with an antigen aerosol during mechanical ventilation and anaesthesia. Six pigs were pretreated with N(G)-nitro-L-arginine (L-NA, 10 mg x kg(-1)), a NO synthase inhibitor, 30 min before challenge. In separate experiments, seven sensitized pigs received histamine (5 mg) aerosols before and after L-NA treatment. It was found that pretreatment with L-NA resulted in an enhanced airways resistance response to antigen (areas under the curve 0-90 min were (mean+/-SEM) 1,119+/-160 versus 555+/-56 (cmH2O x L(-1) x s(-1) x min for controls, p<0.05 (Mann-Whitney U-test), whereas this response to histamine was not affected by L-NA. Moreover, L-NA pretreatment significantly enhanced total protein (1.85+/-0.43 versus 0.31+/-0.06 g x L(-1), p<0.01) and histamine levels (42.8+/-16.0 versus 2.6+/-0.8 nM, p<0.05) in bronchoalveolar lavage fluid 45 min after antigen challenge. In conclusion, this study showed that N(G)-nitro-L-arginine enhanced reactions occurring during the acute allergic reaction in pigs in vivo. This indicates a protective role of nitric oxide, which might occur through downregulation of histamine release from mast cells rather than a direct bronchodilating effect of nitric oxide.

Acute Disease↗
PubMed1999

Effect of cortisol-synthesis inhibition on endotoxin-induced porcine acute lung injury, shock, and nitric oxide production.

In the process of developing a model of Escherichia coli endotoxin-induced acute lung injury and shock in specific pathogen-free pigs, the effects of pretreatment with metyrapone (a cortisol-synthesis inhibitor) were examined. Metyrapone was administered 1.5 h before start of endotoxin infusion at t = 0 h (MET-ETOX group, n = 6). At the end of the experiments (t = 4 h) a bronchoalveolar lavage (BAL) was performed. Control animals received only endotoxin (CON-ETOX group, n = 6) or metyrapone (MET-CON group, n = 4). The following results are presented as means +/- SEM. It was found that metyrapone successfully blocked endogenous cortisol synthesis (plasma cortisol levels were 41.0 +/- 5.9 nM in MET-ETOX vs. 339.0 +/- 37.7 nM in CON-ETOX at t = 4 h, P <0.01). At t = 4 h the MET-ETOX animals had substantially increased systemic hypotension compared to the CON-ETOX group (mean arterial pressure 26.7 +/- 4.3 vs. 77.7 +/- 12.2 mmHg, P <0.01), decreased dynamic lung compliance (10.9 +/- 0.7 vs. 13.7 +/- 0.6 ml/cmH2O, P <0.01), increased percentage of BAL neutrophils (28.4 +/- 6.5 vs. 6.6 +/-1.8, P <0.01), pulmonary edema (BAL total protein 0.82 +/- 0.21 vs. 0.42 +/- 0.09 mg/mL, P <0.05), elevated levels of interleukin-8 (1924 +/- 275 vs. 324 +/- 131 pg/mL, P <0.01) and acidosis (pH 7.11 +/- 0.03 vs. 7.23 +/- 0.06, P <0.05). The MET-ETOX group also showed an increased pulmonary hypertension between 2 and 3 h after start of endotoxin infusion and a trend toward significantly increased levels of plasma interleukin-8 (P = 0.052). Arterial pCO2, pO2/FiO2, plasma endothelin-1, plasma TNFalpha, and blood leukocytes were not markedly influenced by the plasma cortisol levels. Nitric oxide production did not seem to be altered by endotoxin infusion in this model, in contrast to other animal studies; this discrepancy could be thought to be due to endotoxin-dosage differences or species differences. It is concluded that if endogenous cortisol production is blocked by metyrapone, the reactions occurring as a result of the endotoxin-induced acute lung injury and shock are greatly enhanced and that therefore pretreatment with metyrapone might be an important addition to this model with specific pathogen-free pigs.

Acid-Base Imbalance↗
PubMed1997

Tick-host immunology: Significant advances and challenging opportunities.

Immunological interactions at the tick-host interface involve innate and acquired host defenses against infestation and immunomodulatory countermeasures by the tick. The cellular and molecular immunological bases of these host-parasite relationships are being defined. Acquired resistance to tick infestation involves humoral and cellular immunoregulatory and effector pathways. Ticks respond by suppressing antibody production, complement, and cytokine elaboration by both antigen-presenting cells and specific T-cell subsets. Tick-borne disease-causing agents probably exploit tick suppression of host defenses during transmission and initiation of infection. Because of the public health importance of ticks and Pick-borne diseases, it is crucial that we understand these interactions and exploit them in novel immunological control strategies. Here, Stephen Wikel and Douglas Bergman discuss recent advances in understanding tick-host immunology and propose future studies.

Journal Article↗
PubMed1996

Thallium-201 and iodine-131 scintigraphy in differentiated thyroid carcinoma.

UNLABELLED: The purpose of this study was to determine the concordance and discordance between diagnostic 131I and 201TI whole-body scintigraphy in patients with differentiated carcinoma of the thyroid. METHODS: Following thyroidectomy for differentiated thyroid carcinoma, 50 patients underwent whole-body 131I and 201TI scanning (60 pairs of scans in total). Fifteen pairs of studies were obtained before ablative therapy, 30 pairs after ablative therapy and 15 pairs after 131I therapy for metastatic disease. Serum thyroglobulin levels were concurrently determined by radioimmunoassay. RESULTS: Thirty-six 131I whole-body scans (in 34 patients) showed residual uptake in the neck, but only six (17%) of the corresponding whole-body thallium studies had detectable uptake in the neck. Fourteen 131I scans (in nine patients) identified multiple metastatic lesions, whereas the thallium scans were interpreted as either negative, nonspecific or showing fewer lesions. In four study pairs, the thallium scans showed solitary lesions that were not detected by the corresponding radioiodine scans. In 16 scans, the thallium studies gave false-positive results. CONCLUSION: Iodine-131 scintigraphy for differentiated thyroid carcinoma is more sensitive and more specific than 201TI scintigraphy for detection of distant metastases and residual activity in the neck following thyroidectomy.

Adenocarcinoma, Follicular↗
PubMed1995

Metastatic calcification of multiple visceral organs in non-Hodgkin's lymphoma.

A patient with non-Hodgkin's lymphoma who developed acute hypercalcemia following chemotherapy was evaluated for skeletal metastases with a whole-body bone scan. Although metastatic disease is an unlikely cause of hypercalcemia, considering the acutely rising serum calcium, the bone scan is useful in excluding multiple metastases as a cause. In addition, the study demonstrated metastatic calcification in multiple organs, including the pancreas which is uncommon, and the liver and spleen, which is rare.

Calcinosis↗
PubMed1993

Inorganic mercury absorption in mature and immature rat jejunum: transcellular and intercellular pathways in vivo and in everted sacs.

The objective of the present work was to test the hypothesis that toxic and nonessential heavy metals in general, and inorganic Hg in particular, are taken up in rat jejunum by a mechanism similar to that previously proposed for Cd. The initiating step in Cd absorption involves electrostatic interaction of the cation with negative membrane charges. In contrast, Hg appears to react with apical membranes as an anion, although overall uptake is not inhibited by the stilbene inhibitor of anion transport DIDS. Further, the ratio of Cd/Hg uptake falls along the jejunum. However, several similarities between Cd and Hg uptakes were observed. Neither process depends on reactive sulfhydryl groups or on oxidative metabolism. Although tissue Hg, unlike Cd, could not be rigorously separated into membrane-bound and intracellular compartments, uptake of both metals includes their relatively temperature-insensitive and rapid influx into a pool readily accessible to suitable extracellular chelators. Another more temperature-sensitive and slower component leads to the filling of a relatively chelation-resistant compartment, identified in the case of Cd as intracellular. Non-specific membrane properties such as surface charge and perhaps membrane fluidity can thus account for mucosal Cd and Hg uptakes; no contribution of specific transport systems need be postulated. Mucosal permeability, calculated in reference to ethanol uptake as measure of absorbing surface area, falls to the same extent for Cd and Hg during postweaning development. Because this fall, however, parallels a diminution in polar diffusion pathways, the mechanism of the faster metal absorption in weanlings may have little bearing on the slower transcellular process in adults. Incidentally, polar diffusion pathways increase in mature jejunum upon preparation of everted sacs, a further limitation on the usefulness of this preparation for the quantitative study of normal intestinal solute transport.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1993

Synthesis of alpha 1-antichymotrypsin and alpha 1-antitrypsin by human trophoblast.

alpha 1-Antichymotrypsin (alpha 1-ACHY) and alpha 1-antitrypsin (alpha 1-AT) are closely related glycoprotein protease inhibitors, present in plasma and other extracellular fluids, that neutralize proteases released by leukocytes in response to trauma and inflammatory stimuli. Both inhibitors are synthesized primarily by hepatocytes, although lower levels of synthesis by monocytes and breast and intestinal epithelial cells have been demonstrated. Recently, the immunohistochemical localization of alpha 1-AT and alpha 1-ACHY in intrauterine and extrauterine human trophoblastic tissue has been reported. In the present study, we have sought to determine whether human trophoblast is also able to synthesize alpha 1-AT and alpha 1-ACHY. Messenger RNA for both inhibitors was found by Northern blotting in chorionic villi obtained from first trimester and term placenta. Substantial differences in messenger levels for both inhibitors among individual placentas were noted. alpha 1-ACHY and alpha 1-AT messenger was also present in trophoblast cells in primary culture. Synthesis of alpha 1-AT and alpha 1-ACHY protein was demonstrated by SDS-PAGE after immunoprecipitation of [35S]-labeled alpha 1-AT and alpha 1-ACHY from conditioned media of trophoblast cells in culture metabolically labeled with [35S]-methionine. It is of some interest that the M(r) of the alpha 1-AT and alpha 1-ACHY secreted by trophoblast were 50,000 and 49,000, respectively, compared with 54,000 and 68,000 for these proteins in plasma (or secreted by HepG2 human hepatoma and MCF-7 human breast cancer cells).(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1984

Prevention of acute aspirin-induced gastric mucosal injury by 15-R-15 methyl prostaglandin E2: an endoscopic study.

The deleterious effects of aspirin on gastric mucosa have been well documented in experimental and clinical studies. Prostaglandins offer a potential method by which this injury may be prevented. In these studies, we developed a single-dose endoscopic assay system of aspirin-induced gastric mucosal injury in normal volunteers. With this system, 27 of 30 volunteers (90%) demonstrated severe mucosal injury after ingestion of aspirin. Subsequently, we evaluated whether pretreatment with 15-R-15 methyl prostaglandin E2 prevented severe injury after ingestion of aspirin. Following an initial dose-response study, a double-blind crossover trial was performed using pretreatment with placebo or with 10-micrograms doses of 15-R-15 methyl prostaglandin E2 for 24 h before treatment with aspirin. The results of this trial indicate that prostaglandin pretreatment significantly prevented the occurrence of endoscopically visible severe gastric mucosal injury after single-dose aspirin administration.

Adolescent↗
PubMed1982

The effect of hospitalization on intraocular pressure.

Thirteen subjects with open-angle glaucoma or ocular hypertension (five men and eight women, ranging in age from 51 to 73 years) were hospitalized for four to six days during which their intraocular pressures were measured four times a day (8 AM, 2 PM, 6 PM, and 10 PM). After leaving the hospital they returned to the outpatient clinic on several occasions for similar measurements (8 AM). Eight patients were taking timolol, pilocarpine, or both and five were receiving no treatment. In all cases, the 8 AM measurement was lower during hospitalization. The difference between the two sets of measurements was significant at P = .021.

Aged↗
PubMed1977

Human rectal mucosa: proctoscopic and morphological changes caused by laxatives.

To determine whether laxatives alter the proctoscopic and morphological appearances of the human rectum, 10 normal subjects were studied prospectively, and the following manipulations were assessed in a randomized, blinded manner: no treatment; oral mannitol to induce diarrhea; isotonic saline enema; Fleet's Phospho-Soda enema; and bisacodyl (Dulcolax), 10 mg, by enema or suppository. The rectal mucosa after mannitol-induced diarrhea, or after saline enema could not be distinguished from untreated rectum by proctoscopy, light microscopy, or scanning electron microscopy. Fleet's enema, and bisacodyl invariably changed proctoscopic appearances, and frequently altered light and scanning microscopic aspects. Both Fleet's enema and bisacodyl caused sloughing of surface epithelium. In addition, bisacodyl decreased the uptake of hematoxylin and eosin by crypt epithelial cells so that the affected cells had a partially erased appearance (16 of 25 biopsies examined by light microscopy). The lamina propria of 3 of these 25 biopsies contained polymorphonuclear cells. Transmission electron microscopy revealed that the abnormal crypt epithelial cells contained fewer cytoplasmic organelles and less nuclear chromatin. All lesions resolved within 7 days. Fleet's enema and bisacodyl by rectum may mislead the proctologist and the pathologist by altering normal rectal mucosa.

Bisacodyl↗
PubMedDate not supplied

Glomerulopathy in acute and chronic rejection: relationship of ultrastructure to graft survival.

The glomerular ultrastructure was retrospectively reviewed from 45 renal transplant biopsies with the clinical and light microscopic diagnosis of acute rejection (25 cases) and chronic rejection (20 cases). Three grades of morphologic alteration were ultrastructurally defined. In acute rejection, capillary lumenal obliteration with endothelial cell hypertrophy and cellular infiltration were interpreted as the local glomerular expression of the endothelial vascular alterations of acute humoral rejection and were correlated with a poor graft survival. Graft nephrectomy was necessary in 9 of 11 patients with grade III glomerulopathy. In chronic rejection, thickened basement membranes and increased amount of mesangial matrix were considered the result of ischemia. The degree of ultrastructural glomerular alterations in chronic rejection did not correlate with graft survival. Urine protein values were consistently elevated, although poorly correlated with the severity of glomerular alterations. Recurrent glomerulonephritis was not documented in any case. We concluded that the glomerular alteration in acute rejection is a component of acute humoral rejection and that the degree of glomerulopathy in acute rejection is a good predictor of the graft survival.

Graft Rejection↗