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1.
Pulm Pharmacol Ther ; 20(2): 163-6, 2007.
Article in English | MEDLINE | ID: mdl-16798035

ABSTRACT

Smoke inhalation in burn patients is a serious medical problem around the world. Inhalation injury increases mortality in addition to increasing infections, ventilator-days, and hospital stays. There are also large numbers of patients subjected to smoke inhalation without burns from cooking fires, burning crops and forest fires. The injury results in a fall in arterial oxygenation as a result of airway blockade, increased pulmonary transvascular fluid flux and loss of hypoxic pulmonary vasoconstriction. The changes in cardiopulmonary function are mediated at least in part by reactive oxygen and nitrogen species. Nitric oxide (NO) is generated by both inducible and constitutive isoforms of nitric oxide synthase (NOS). NO combines with superoxide to form reactive nitrogen species such as peroxynitrite. These reactive nitrogen species can be detected by measuring their reaction products such as 3-nitrotyrosine. The latter is elevated in the airway following smoke/burn injury. The control of NO formation involves poly (ADP ribose) polymerase (PARP) and its ability to up-regulate the activity of nuclear transcription factors through ribosylation. Present data also support a major role for the bronchial circulation in the injury since blockade of bronchial blood flow will also minimize the pulmonary injury. The data suggest that cytotoxins or activated cells are formed in the airway and carried to the parenchyma. These materials cause the formation of oedema and a reduction of PaO(2).


Subject(s)
Bronchi/blood supply , Lung/physiopathology , Pulmonary Circulation/physiology , Smoke Inhalation Injury/complications , Acute Disease , Animals , Bronchi/metabolism , Humans , Lung/blood supply , Lung Injury , Nitric Oxide Synthase/metabolism , Peroxisome Proliferator-Activated Receptors/metabolism , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/physiopathology
2.
Burns ; 30(6): 565-8, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15302422

ABSTRACT

Hepatomegaly is a common finding at autopsy in severely burned children surviving less than 6 months. This study validates a reliable ultrasound method which can be used to identify changes in liver size in severely burned children during acute hospitalization. Thirty-eight children, age 0.5-17 years with burns covering over 40% of their total surface area were studied at autopsy. Liver weight was measured at autopsy and compared to predicted liver weight for age and height. Eighteen had liver size measured by ultrasound within 10 days of death while five had ultrasound liver measures after death just prior to autopsy. All burned children who survived 7 days or more (n = 33) had liver weights at autopsy that were greater than predicted for age and height while all 23 livers measured by ultrasound were greater than predicted. Autopsy weights correlated well with weights estimated by ultrasound, R = 0.824. At autopsy, those who survived 7 days or more had enlarged livers ranging from 142 to 406% of their predicted normal age and height. Common histologic findings include large and small-droplet fat deposits, and cholestasis. The degree of these histologic abnormalities correlated with the increase in liver weight, R = 0.652. Ultrasound is a valid, noninvasive method for measuring liver weight changes in severely burned children during acute hospitalization. Ninety-five percent of the severely burned children from this institute had significant hepatomegaly identified at autopsy.


Subject(s)
Burns/diagnostic imaging , Liver/diagnostic imaging , Adolescent , Autopsy , Body Surface Area , Burns/mortality , Burns/pathology , Child , Child, Preschool , Female , Hepatomegaly/diagnostic imaging , Hepatomegaly/pathology , Humans , Infant , Liver/pathology , Male , Organ Size/physiology , Ultrasonography
3.
J Clin Pathol ; 57(8): 849-55, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15280407

ABSTRACT

BACKGROUND: Congenital neomelanocytic naevi appear in nearly 1% of newborns. Giant hairy naevi (GHN) are uncommon lesions covering large areas of the body. They are of concern because they have the potential to transform into malignant melanomas. AIMS: To describe gene expression profiles of GHN and nearby normal skin from patients with GHN and normal control skin (from patients with cleft lip/palate). METHODS: Tissues from three patients with GHN and two normal controls were studied for differences in gene expression profiles. Total RNA was isolated from normal skin near the hairy naevus, GHN, and skin from normal controls. The RNA samples were subjected to probe labelling, hybridisation to chips, and image acquisition according to the standard Affymetrix protocol. RESULTS: There were 227 genes affected across all samples, as determined by DNA microarray analysis. There was increased expression of 22 genes in GHN compared with nearby normal skin. Decreased expression was noted in 73 genes. In addition, there was increased expression of 36 genes in normal skin near GHN compared with normal control skin, and decreased expression of five genes. Categories of genes affected were those encoding structural proteins, proteins related to developmental processes, cell death associated proteins, transcription factors, growth factors, stress response modulators, and collagen associated proteins. Changes in mRNA expression were checked by reverse transcription polymerase chain reaction. CONCLUSIONS: Genetic profiles of GHN may provide insight into their pathogenesis, including their potential for malignant transformation. Such information may be useful in improving the understanding and management of these lesions.


Subject(s)
Nevus, Pigmented/genetics , Skin Neoplasms/genetics , Adolescent , Adult , Case-Control Studies , Child , Child, Preschool , Gene Expression Profiling , Humans , Male , Nevus, Pigmented/pathology , Oligonucleotide Array Sequence Analysis , Reverse Transcriptase Polymerase Chain Reaction , Skin/metabolism , Skin Neoplasms/pathology
4.
J Photochem Photobiol B ; 64(1): 8-20, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11705725

ABSTRACT

Results are reported on the cellular effects and the sensitivity of cultured tumor epithelial cells (TEC) derived from human ovarian cystadenocarcinoma and human umbilical vein-derived endothelial cells (HUVEC) to exogenous 5-aminolaevulinic acid (ALA) and ALA-induced photodynamic therapy (PDT). Cellular alterations and PDT efficiency were evaluated using colorimetric thiazolyl blue (MTT) assay, trypan blue exclusion assay, electron microscopy, and gel electrophoresis. ALA-induced protoporphyrin IX (PpIX) accumulation in TEC was associated with a concentration and time-dependent significant decrease in mitochondrial activity, increase in cell membrane permeability, and dark toxicity. Maximum PpIX loaded TEC demonstrated a high sensitivity to PDT. Neither cellular alterations nor PDT effects were observed in HUVEC under identical experimental conditions. These results indicate a potential clinical value for the use of ALA-mediated PDT to treat minimal residual disease in mucinous ovarian carcinoma. In addition, the ALA-induced PpIX cytotoxicity may be exported to a new chemotherapeutic regimen via a conventionally viewed photochemotherapeutic agent.


Subject(s)
Aminolevulinic Acid/toxicity , Endothelium, Vascular/drug effects , Ovarian Neoplasms/pathology , Photosensitizing Agents/toxicity , Aminolevulinic Acid/pharmacokinetics , Cell Membrane Permeability/drug effects , Cell Survival/drug effects , Cells, Cultured , Cystadenocarcinoma, Mucinous/pathology , Dose-Response Relationship, Drug , Epithelial Cells/drug effects , Epithelial Cells/ultrastructure , Female , Humans , Kinetics , Light , Mitochondria/drug effects , Mitochondria/metabolism , Photosensitizing Agents/pharmacokinetics , Protoporphyrins/metabolism , Reactive Oxygen Species/metabolism , Tumor Cells, Cultured , Umbilical Veins
5.
J Am Acad Dermatol ; 45(6 Suppl): S233-4, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11712070

ABSTRACT

The occurrence of Langerhans cell histiocytosis (LCH) and malignancy in the same patient is rare. When LCH occurs concomitantly with acute leukemia, distinct temporal patterns often exist; acute myelogenous leukemia (AML) typically succeeds LCH, whereas acute lymphocytic leukemia (ALL) usually precedes it. We report a case of LCH developing in a child while in remission for ALL. Unique features of this case include the disseminated nature of the LCH and the death of the patient from LCH rather than ALL.


Subject(s)
Histiocytosis, Langerhans-Cell/diagnosis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/complications , Skin Diseases/diagnosis , Back , Child, Preschool , Diagnosis, Differential , Fatal Outcome , Histiocytosis, Langerhans-Cell/complications , Histiocytosis, Langerhans-Cell/pathology , Humans , Male , Skin Diseases/complications , Skin Diseases/pathology
6.
Endocr Res ; 27(3): 345-56, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11678582

ABSTRACT

In the present study, the effects of orally-administered lithium on testicular morphology were examined in the spotted munia (Lonchura punctulata), a seasonally breeding sub-tropical finch. Adult males were procured from natural populations during the month of August, a time when these birds begin to show seasonal reproductive maturity in an annual cycle. Both during the period of acclimation, and throughout the subsequent experimental period, the birds were maintained in an open aviary simulating natural environmental conditions. Lithium was dissolved in distilled water and was administered via the oral route by means of a commercially available stomach-tube. A total of five experimental groups were utilized. The first group (Group A) served as control and received lithium-free distilled water in a similar manner. In the remaining four groups, lithium was administered daily as follows: Group B (2.5 mEq/Kg body weight for 5 days); Group C (2.5 mEq/Kg for 10 days); Group D (5.0 mEq/Kg for 5 days) and Group E (5.0 mEq/Kg for 10 days). All lithium administrations were carried out between 14:00 and 15:00h. Twenty-four hours after the last oral lithium, final body weights were recorded, blood samples were obtained (by brachial vein puncture for the measurement of serum lithium) and the animals were sacrificed, and testes were collected for histological studies. Our results indicated that lithium treatment led to a significant reduction in testicular weight and seminiferous tubular diameter, and a marked degenerative changes in germ cells in that most of the spermatids and mature spermatozoa showed necrotic changes and were sloughed off from the seminiferous tubular epithelium. Complete desquamation and loss of germ cells, and their clump formation were also noted within many seminiferous tubular lumen. Notably these adverse effects were observed when serum lithium levels were within the therapeutic range for human. These results confirm our earlier report on lithium's adverse effects on testicular function, and extend further to show that lithium indeed has a significant adverse effect on the histomorphology, and, thus, the function of the testis in birds.


Subject(s)
Lithium Chloride/adverse effects , Songbirds/physiology , Spermatozoa/pathology , Testis/drug effects , Animals , Behavior, Animal/drug effects , Body Weight , Leydig Cells/pathology , Lithium/blood , Lithium Chloride/administration & dosage , Male , Necrosis , Organ Size/drug effects , Seasons , Seminiferous Tubules/pathology , Spermatids/pathology , Testis/pathology
7.
Am J Physiol Gastrointest Liver Physiol ; 280(6): G1314-20, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11352826

ABSTRACT

Thermal injury has been shown to alter gut epithelium and heart myocyte homeostasis by inducing programmed cell death. The effect of thermal injury on hepatocyte apoptosis and proliferation, however, has not been established. The purpose of this study was to determine whether a large thermal injury increases liver cell apoptosis and proliferation and whether these changes were associated with alterations in hepatic nuclear factor kappaB (NF-kappaB) expression and changes in liver enzymes and amount of protein. Sprague-Dawley rats received a 40% total body surface area scald burn or sham burn. Rats were killed and livers were harvested at 1, 2, 5, and 7 days after burn. Liver cell apoptosis was determined by terminal deoxyuridine nick end labeling (TUNEL) assay and cell proliferation by immunohistochemistry for proliferating cell nuclear antigen. Hepatic NF-kappaB expression was determined by Western blot, and total hepatic protein content was determined by protein assay. Protein concentration decreased after burn compared with sham controls (P < 0.05). Liver cell apoptosis, proliferation, and NF-kappaB expression in hepatocytes increased in burned rats compared with controls (P < 0.05). It was concluded that thermal injury induces hepatic cell apoptosis and proliferation associated with an increase in hepatic NF-kappaB expression and a decrease in hepatic protein concentration.


Subject(s)
Apoptosis , Burns/pathology , Burns/physiopathology , Enzymes/metabolism , Liver/pathology , Liver/physiopathology , NF-kappa B/metabolism , Alkaline Phosphatase/metabolism , Animals , Caspase 3 , Caspases/metabolism , Cell Division , Male , Organ Size , Rats , Rats, Sprague-Dawley , Time Factors
8.
J Burn Care Rehabil ; 22(6): 375-83, 2001.
Article in English | MEDLINE | ID: mdl-11761387

ABSTRACT

Recent studies suggest a role of endothelin-1 (ET-1) in mediating airway inflammation and lung injury. The aim of this study was to assess the immunohistochemical expression of ET-1 in the lung following smoke inhalation injury. ET-1 immunoreactivity was assessed in normal sheep (N = 4) and in sheep at 1 (N = 2), 6 (N = 3), 12 (N = 3), and 24 (N = 3) hours after inhalation injury. In normal animals, ET-1 expression was limited to the basal cell layer of the tracheal epithelium, main bronchi, and associated mucous glands. One hour after injury, ET-1 immunoreactivity was enhanced in upper airway epithelium and mucus glands with new expression in bronchioles. Airway smooth muscle, vascular tissue, and alveolar duct smooth muscle cells expressed moderate levels of ET-1 at 12 and 24 hours. ET-1 immunoreactivity was absent in areas of parenchymal edema and inflammation. The pattern of ET-1 expression following inhalation injury suggests that this peptide may contribute to the airway inflammation, mucus secretion, pulmonary hypertension, increased airway resistance, and decreased lung compliance, which are evident in our ovine model of inhalation injury.


Subject(s)
Endothelin-1/metabolism , Lung/metabolism , Lung/pathology , Smoke Inhalation Injury/metabolism , Smoke Inhalation Injury/pathology , Animals , Disease Models, Animal , Muscle, Smooth/metabolism , Muscle, Smooth/pathology , Respiratory Mucosa/metabolism , Respiratory Mucosa/pathology , Sheep , Time Factors , Trachea/metabolism , Trachea/pathology
9.
Arch Pathol Lab Med ; 124(12): 1804-8, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11100061

ABSTRACT

The expression of myelomonocytic-associated antigens in anaplastic large cell lymphomas (ALCLs), particularly those presenting in extranodal sites, can make their distinction from extramedullary myeloid cell tumors (EMCTs) or histiocytic tumors problematic. Yet, this distinction is clinically significant because of its therapeutic and prognostic implications. Herein, we describe a case of extranodal anaplastic lymphoma kinase-positive CD30-positive ALCL of T-cell origin in a 12-year-old boy, which was initially called an EMCT because of the expression of CD13 and HLA-DR detected by flow cytometry and the absence of other T-cell-related surface markers. However, the detection of cytoplasmic CD3 by flow cytometry prompted further studies. The tumor was composed of large cells with abundant slightly eosinophilic vacuolated cytoplasm and ovoid or reniform nuclei with a few small nucleoli. Using immunohistochemistry, the tumor was positive for CD45, CD30, CD45RO, and CD43 with a strong cytoplasmic and nuclear anaplastic lymphoma kinase stain. The tumor cells showed a T-cell clonal genotype. Electron microscopy revealed no ultrastructural features of myelomonocytic or histiocytic origin. The patient responded well to the chemotherapy and was in complete remission for 10 months at the time of submission of this manuscript. Review of the literature showed inconsistencies regarding the diagnosis, nomenclature, and, therefore, treatment and prognosis of these tumors. In addition, the CD13 expression in ALCL raises some histogenetic questions and may indicate origin from a pluripotent stem cell, misprogramming during malignant transformation, or a microenvironmental effect on lymphoid cell expression of surface antigens. Therefore, ALCL should be considered in the differential diagnosis of EMCTs or histiocytic tumors, particularly when surface marker lineage assignment is ambiguous.


Subject(s)
Antigens, CD , CD13 Antigens/analysis , Lymphoma, Large-Cell, Anaplastic/pathology , T-Lymphocytes/pathology , Adolescent , Adult , Child , Female , Flow Cytometry , Humans , Immunohistochemistry , Leukocyte Common Antigens/analysis , Leukosialin , Lymphoma, Large-Cell, Anaplastic/metabolism , Male , Sialoglycoproteins/analysis , T-Lymphocytes/chemistry
10.
Anat Rec ; 260(4): 410-5, 2000 12 01.
Article in English | MEDLINE | ID: mdl-11074407

ABSTRACT

Electron microscopic techniques have been used to profile the morphologies of marrow sacs in different laboratory species. These structures all comprise a condensed layer of overlapping fibroblast-like stromal cells and apparently confine the medullary and endosteal osteoblast/lining cells to separate histiotypic compartments. There were some variations in the morphology of the sac cells in the different species. In rats, cats, and sheep, scanning electron microscopy (SEM) showed a seamless arrangement of marrow sac cells which resembled a thin, flat simple squamous epithelium; they displayed few intercellular cytoplasmic processes. In the rabbit and pigeon, the sac comprised a more woven, multilayered fabric of broadly elongate flat fibroblast-like cells which displayed numerous intercellular processes. Transmission electron microscopy (TEM) showed that all marrow sac cells were attenuated with elongated nuclei, a few small round mitochondria, and a sparse rough endoplasmic reticulum. In the majority of animals, the sac was one to two cell layers thick. The rabbit and pigeon sacs were multilayered, and never less than three to four cells deep. The cell layers were not closely apposed. Tight or gap junctions were absent at the points of intercellular contact. These morphological results suggest that marrow sacs are common elements of the vertebrate skeleton with species specific morphologies.


Subject(s)
Bone Marrow Cells/ultrastructure , Femur/cytology , Animals , Cats , Columbidae , Female , Male , Microscopy, Electron, Scanning , Rabbits , Rats , Sheep , Species Specificity , Stromal Cells/ultrastructure
11.
Laryngoscope ; 110(9): 1548-51, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10983959

ABSTRACT

OBJECTIVE: To develop a cost-effective protocol for diagnosing primary ciliary dyskinesia (PCD). STUDY DESIGN: Retrospective chart review in a tertiary care academic medical center. METHODS: A review of the electron microscopy logbook identified all patients who had a suspected diagnosis of PCD. Biopsy of respiratory tract mucosa was performed using a cytology brush or a cup forceps in the outpatient clinic or operating room (OR). Outcome measures were to determine the diagnostic adequacy of cytological evaluation compared with tissue biopsy and to determine whether an adequate nasal mucosa sample can be collected in the outpatient clinic setting as compared with the OR and the use of general anesthesia RESULTS: Twenty-seven patients underwent 31 biopsies. Fifteen specimens were collected with a cup forceps, and 16 with a cytology brush. The sampling sites were nasal mucosa in 28 cases and trachea in the rest. Twelve specimens (39%) were collected in the clinic; the rest were obtained in the OR in conjunction with another procedure. Neither method of specimen collection nor mode of anesthesia made a significant difference in the probability of obtaining an adequate specimen. Ten samples were nondiagnostic: cytological evaluation, 31% (n = 16); tissue biopsy, 27% (n = 15); clinic, 42% (n = 12); and OR, 31% (n = 16). The cost of evaluating ciliary motion at our institution was $150, with an additional charge of $1,297 for electron microscopic evaluation. The nonprofessional fee for an outpatient nasal biopsy was $98; in the OR the cost of anesthesia supplies, surgical suite, recovery room, and day-surgery bed was at least $1,860. CONCLUSION: Our results suggest that the optimal method for diagnosis of PCD is in the outpatient clinic with specimen collection by means of either a cup forceps or a cytology brush.


Subject(s)
Biopsy/economics , Ciliary Motility Disorders/diagnosis , Cytodiagnosis/economics , Nasal Mucosa/pathology , Algorithms , Ciliary Motility Disorders/economics , Costs and Cost Analysis , Cytodiagnosis/methods , Humans , Retrospective Studies
12.
J Trauma ; 49(2): 251-63; discussion 263-5, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10963536

ABSTRACT

BACKGROUND: The large fluid volumes usually required for burn resuscitation can be suppressed for 8 to 12 hours by intravenous infusion of 4 mL x kg(-1) hypertonic saline dextran (HSD) 1 hour after burn. We hypothesized that a double (8 mL x kg(-1)) dose of HSD or two repeated doses of 4 mL x kg(-1) could enhance or prolong the volume sparing. METHODS: We produced a full-thickness flame burn covering 40% of the body surface on 18 anesthetized sheep. One hour after the burn, the animals were awake and resuscitated with either (1) lactated Ringer's solution (LR) only, (2) 8 mL x kg(-1) HSD followed by LR, or (3) 4 mL x kg(-1) HSD followed by LR, with a second dose of 4 mL x kg(-1) HSD administered when net fluid accumulation increased to 20 mL x kg(-1). For all regimens, infusion rates were adjusted to produce a urine output of 1 to 2 mL x kg(-1) x h(-1). RESULTS: Animals resuscitated with only LR required fluid volumes identical to that predicted by the Parkland formula for the first 12 hours. Infusion of 8 mL x kg(-1) HSD initially created a net fluid loss (urine output > infused volume), followed by a rebound fluid requirement eventually equaling that of animals treated with LR only. Animals treated with two separate doses of 4 mL x kg(-1) HSD generally did not experience a net fluid loss or a rebound fluid requirement. Also in the HSD x 2 group, peak and net fluid accumulation was less than that of the other two groups from 18 hours through 48 hours, although the difference was not significant. CONCLUSION: An initial 4 mL x kg(-1) dose of HSD reduces fluid requirements early after burn, and a second dose administered after an appropriate interval may prolong volume sparing through 48 hours. An 8 mL x kg(-1) continuously infused initial dose was without prolonged fluid sparing effect. The volume-sparing effect of HSD is thus dependent on all of the following: dose, dosing interval, and infusion rate.


Subject(s)
Burns/therapy , Dextrans/administration & dosage , Rehydration Solutions/administration & dosage , Shock, Traumatic/therapy , Animals , Burns/blood , Burns/physiopathology , Disease Models, Animal , Drug Administration Schedule , Edema/prevention & control , Female , Fluid Shifts , Hemodynamics/drug effects , Infusions, Intravenous , Prospective Studies , Resuscitation , Saline Solution, Hypertonic/administration & dosage , Sheep , Shock, Traumatic/blood , Shock, Traumatic/physiopathology , Time Factors
13.
Lab Invest ; 80(2): 151-8, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10701685

ABSTRACT

Gene therapy using cationic liposomes containing cDNA is a relatively new approach with great potential; however, little is known about the mechanisms of dermal gene transfer, its biodistribution, systemic transfection, and cellular uptake. This study identifies mechanisms, transfection rates, and biodistribution of liposomal gene transfers in the skin of thermally injured rats using cDNA gene constructs coding for insulin-like growth factor-I (IGF-I) and Lac Z. Male Sprague-Dawley rats (350 to 375 g) were given a 60% total body surface area full-thickness scald burn that was followed by weekly subcutaneous injections of normal saline (control, n = 10), liposomes plus 0.2 microg Lac Z cDNA construct driven by a cytomegalovirus (CMV) promoter (vehicle, n = 10), or liposomes containing 2.2 microg cDNA coding for IGF-I plus 0.2 microg Lac Z cDNA construct driven by a CMV promoter (IGF-I cDNA, n = 10). Gene transfection was determined by histochemical and luminescent beta-galactosidase assays of blood, skin, liver, spleen, and kidney. Transcription of IGF-I cDNA to IGF-I mRNA was determined in skin cells by Northern blot analyses. Levels of IGF-I protein in blood, skin, liver, spleen, and kidney were measured by radioimmunoassay. The biological activity of the translated IGF-I was evaluated by the mitogenic activity in dermal cells and the rate of re-epithelization. Gene transfection was observed only in skin cells. The expression of IGF-I mRNA increased in skin cells of burned rats receiving liposomes containing the IGF-I cDNA construct compared with liposomes without the construct or normal saline. IGF-I protein levels in the skin of rats receiving the IGF-I cDNA was 176 +/- 4 ng/ml compared with 105 +/- 6 ng/ml for liposomes alone or 90 +/-3 ng/ml for saline (p < 0.05). The translated IGF-I protein was found biologically active in the skin by increasing skin cell proliferation and accelerating re-epithelization 33 days after thermal injury (p < 0.05). No systemic transfection could be detected. Skin cells transfected with liposomes encapsulating the IGF-I cDNA constructs increased the expression of IGF-I mRNA transcript and the expression of a biologically active IGF-I protein. Liposomes containing the cDNA coding for IGF-I present an effective approach to gene therapy in the skin.


Subject(s)
Burns/therapy , Gene Transfer Techniques , Insulin-Like Growth Factor I/genetics , Animals , Burns/metabolism , Cell Division , Genetic Therapy , Liposomes , Male , Protein Biosynthesis , RNA, Messenger/genetics , Rats , Rats, Sprague-Dawley , Transcription, Genetic , beta-Galactosidase/genetics
14.
Crit Care Med ; 28(12): 3885-90, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11153630

ABSTRACT

OBJECTIVE: To test the hypothesis that the hypocalcemia and hypoparathyroidism that follow severe burn injury are related to up-regulation of the parathyroid gland calcium-sensing receptor (CaR), which may reduce the set-point for suppression of circulating parathyroid hormone by blood calcium. DESIGN: A controlled but unblinded study. SETTING: An investigational intensive care unit. SUBJECTS: Female range ewes. INTERVENTION: Sheep were subjected to a 40% total body surface area burn under anesthesia (n = 9) or sham burn receiving anesthesia and fluid resuscitation only (n = 8) and were killed 48 hrs postburn. MEASUREMENTS AND RESULTS: Blood ionized calcium, magnesium, and creatinine, and urinary calcium, magnesium, and creatinine were monitored for 48 hrs. After the sheep were killed, parathyroids (burn group, n = 3; sham group, n = 4) and kidneys (n = 4, each group) were harvested, snap frozen in liquid nitrogen, and analyzed for CaR messenger ribonucleic acid (mRNA) by Northern blot, and were analyzed for CaR cell-surface staining by immunocytochemistry with a polyclonal CaR-specific antiserum (parathyroids only). Bumed sheep were hypocalcemic and hypomagnesemic compared with sham-burned control sheep. CaR mRNA was increased by 50% (p < 0.005, analysis of variance) with a corresponding increase in the intensity of CaR immunoreactivity associated with the cell surface in parathyroids obtained from burned (n = 3) compared with sham-burned (n = 2) sheep. These findings are consistent with up-regulation of the parathyroid CaR and a related decrease in set-point for calcium suppression of parathyroid hormone secretion that may contribute to the previously reported postburn hypoparathyroidism and hypocalcemia.


Subject(s)
Burns/complications , Calcium/blood , Disease Models, Animal , Hypocalcemia/etiology , Hypocalcemia/metabolism , Hypoparathyroidism/etiology , Hypoparathyroidism/metabolism , Parathyroid Hormone/physiology , Receptors, Cell Surface/physiology , Up-Regulation/physiology , Animals , Blotting, Northern , Female , Fluid Therapy , Hypocalcemia/pathology , Hypoparathyroidism/pathology , Immunohistochemistry , Magnesium Deficiency/etiology , Magnesium Deficiency/metabolism , Receptors, Calcium-Sensing , Receptors, Cell Surface/analysis , Risk Factors , Sheep , Time Factors
15.
Arch Surg ; 134(10): 1137-41, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10522861

ABSTRACT

HYPOTHESIS: Multiple subcutaneous injections of cholesterol-containing cationic liposomes encapsulating the complementary DNA (cDNA) gene for insulinlike growth factor I (IGF-I) increase the rate of transfected skin cells and result in increased IGF-I protein levels in the skin with subsequent improvement in wound healing when compared with a single injection. SETTING: Laboratory. INTERVENTION: Twenty-four adult male Sprague-Dawley rats (350-375 g) received a full-thickness scald burn on 60% of their body surface. These rats were randomly divided to receive either 1 injection of liposomes containing 2.2 microg-cytomegalovirus-driven cDNA coding for IGF-I and 0.2 microg of the Lac Z gene cDNA construct, or 2 injections of liposomes containing 2.2 microg cytomegalovirus-driven cDNA coding for IGF-I and 0.2 microg of the Lac Z gene cDNA construct. MAIN OUTCOME MEASURES: Transfection rates and IGF-I protein levels in the skin and physiological responses to the IGF-I gene therapy, evaluated from changes in body weight, protein content in serum and liver, and the rate of burn wound healing. RESULTS: There was a significant decrease in transfection rate and IGF-I protein expression distal from the injection site in animals receiving 1 injection, as compared with a consistent increase in rats receiving multiple injections. Multiple injections improved the response to thermal trauma by increasing the extent of the healed burn wound 33 days after thermal injury (single injection, 31% +/- 1% vs multiple injections, 38% +/- 2%), total serum protein (single injection, 52 +/- 0.5 g/L vs multiple injections, 55 +/- 0.6 g/L), and total liver protein (single injection, 82.0 +/- 0.3 mg/mL vs multiple injections, 91.0 +/- 3.8 mg/mL), P<.05. CONCLUSIONS: Gene transfer rates can be increased by multiple injections of liposomes encapsulating IGF-I cDNA constructs. Increased transfer results in greater IGF-I protein skin concentrations, accelerated wound healing, and increased serum and liver protein concentrations. The clinical relevance of these findings is that liposomal gene constructs should be applied in well-defined distances to improve gene transfer in the skin, and thus clinical outcome after thermal injury.


Subject(s)
Burns/therapy , DNA, Complementary/administration & dosage , Gene Transfer Techniques , Genetic Therapy , Insulin-Like Growth Factor I/genetics , Animals , Drug Carriers , Liposomes , Male , Random Allocation , Rats , Rats, Sprague-Dawley
16.
Gene Ther ; 6(6): 1015-20, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10455403

ABSTRACT

Exogenous insulin-like growth factor-I (IGF-I) is known to improve the pathophysiology of a thermal injury, however, deleterious side-effects have limited its utility. Cholesterol-containing cationic liposomes that encapsulate complementary DNA (cDNA) are nonviral carriers used for in vivo gene transfection. We propose that liposome IGF-I gene transfer will accelerate wound healing in burned rats and attenuate deleterious side-effects associated with high levels of IGF-I. To test this hypothesis IGF-I gene constructs, encapsulated in liposomes, were studied for their efficacy in modulating the thermal injury response. Thirty adult male Sprague-Dawley rats were given a 60% TBSA scald burn and randomly divided into three groups to receive weekly subcutaneous injections of liposomes plus the lacZ gene coding for beta-galactosidase, liposomes plus cDNA for IGF-I and beta-galactosidase or liposomes plus the rhIGF-I protein. Body weights and wound healing were measured. Muscle and liver dry/wet weights and IGF-I concentrations in serum, skin and liver were measured by radioimmunoassay. Transfection was confirmed by histochemical staining for beta-galactosidase. Rats receiving the IGF-I cDNA constructs exhibited the most rapid wound re-epithelialization and greatest increase in body weight and gastrocnemius muscle protein content (P < 0.05). Local IGF-I protein concentrations in the skin were higher when compared to liposomes containing only the lacZ gene (P < 0.05) Transfection was apparent in the cytoplasm of myofibroblasts, endothelial cells and macrophages of the granulation tissue. Liposomes containing the IGF-I gene constructs proved effective in preventing muscle protein wasting and preserving total body weight after a severe thermal injury.


Subject(s)
Burns/therapy , Genetic Therapy/methods , Insulin-Like Growth Factor I/genetics , Animals , Liposomes , Male , Rats , Rats, Sprague-Dawley , Wound Healing
17.
J Appl Physiol (1985) ; 86(4): 1151-9, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10194196

ABSTRACT

The effects of a monoclonal antibody against L-selectin [leukocyte adhesion molecule (LAM)1-3] on microvascular fluid flux were determined in conscious sheep subjected to a combined injury of 40% third-degree burn and smoke inhalation. This combined injury induced a rapid increase in systemic prefemoral lymph flow (sQlymph) from the burned area and a delayed-onset increase in lung lymph flow. The initial increase in sQlymph was associated with an elevation of the lymph-to-plasma oncotic pressure ratio; consequently, it leads to a predominant increase in the systemic soft tissue permeability index (sPI). In an untreated control group, the increased sPI was sustained beyond 24 h after injury. Pretreatment with LAM1-3 resulted in earlier recovery from the increased sPI, although the initial responses in sQlymph and sPI were identical to those in the nontreatment group. The delayed-onset lung permeability changes were significantly attenuated by pretreatment with LAM1-3. These findings indicate that both leukocyte-dependent and -independent mechanisms are involved in the pathogenesis that occurs after combined injury with burn and smoke inhalation.


Subject(s)
Burns/physiopathology , Hemodynamics , L-Selectin/physiology , Microcirculation/physiopathology , Pulmonary Circulation/physiology , Smoke Inhalation Injury/physiopathology , Animals , Antibodies, Monoclonal/pharmacology , Blood Pressure , Cardiac Output , Female , L-Selectin/immunology , Lymph/physiology , Oxygen/blood , Sheep , Time Factors
18.
Endocr Res ; 25(1): 35-49, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10098592

ABSTRACT

In this report, we have examined the effects of lithium on testicular morphology in a male subtropical wild avian species, the roseringed parakeet (Psittacula krameri). Adult male birds were collected during the months of February-March, a time when the testicular gametogenic activity in these seasonally breeding birds is at its peak. They were injected, intramuscularly, twice daily (07:00 and 19:00 h) with lithium chloride (Sigma Chemical Company) at a dosage of 0.5 mEq/Kg body weight either for 5 or 10 days. A significant decrease in both the absolute and relative testicular weights was evident in the lithium-treated birds as compared to those of the saline-injected control animals. Light microscopic studies of the testis in the lithium-treated animals showed a wide range of degenerative changes. These included a) a significant reduction in the diameter of seminiferous tubules; b) necrosis and exfoliation of most of the germ cells in the seminiferous tubular lumen with the exception of the spermatogonia; and c) a significant reduction in the number of mature spermatozoa in the tubular lumen. These degenerative changes were dependent on the duration of lithium treatment and were evident when the plasma lithium concentrations were well below the human therapeutic range. Leydig cell morphology was not affected by lithium however. Our results provide the first experimental evidence of lithium's adverse reproductive function in an avian species. These data provide further support to the view that lithium adversely affects the male reproductive system and that these effects extend beyond mammalian species.


Subject(s)
Antimanic Agents/pharmacology , Lithium Chloride/pharmacology , Parakeets/physiology , Spermatogenesis/drug effects , Testis/drug effects , Testis/pathology , Animals , Body Weight/drug effects , Lithium/blood , Male , Organ Size/drug effects , Seminiferous Tubules/drug effects , Seminiferous Tubules/pathology , Testis/physiopathology
19.
Lung ; 177(2): 111-22, 1999.
Article in English | MEDLINE | ID: mdl-9929408

ABSTRACT

The dose dependence and time course of smoke inhalation injury were determined in a rabbit model. Animals were insufflated with 18-90 breaths of cotton smoke or room air (control) at a rate of 18 breaths/min and tidal volume of 12 ml/kg. Smoke-exposed animals exhibited dose-related histologic effects with progressive deterioration of respiratory function during the postexposure period of observation (96 h). The smoke-exposed rabbits had reproducible injuries to both airway mucosa and lung parenchyma, manifested by disruption and sloughing of airway and alveolar epithelia, and exudation of protein-rich fluid and leukocytes into the airway and alveolar spaces. Significant effects were evident by 24 h postexposure. Smoke inhalation also affected the respiratory burst of alveolar macrophages. Generation of superoxide anions by alveolar macrophages at 48 h postexposure was increased significantly after smoke inhalation (54 breaths). The present rabbit model should be useful for studying the interactions between pulmonary epithelial cells and leukocytes after smoke inhalation and for determining the role that abnormal functioning of alveolar macrophages plays in the development of smoke inhalation injury.


Subject(s)
Lung/pathology , Smoke Inhalation Injury/pathology , Smoke/adverse effects , Animals , Dose-Response Relationship, Drug , Epithelium/pathology , Macrophages, Alveolar/pathology , Male , Rabbits , Respiratory Burst/physiology , Superoxides/metabolism
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