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1.
J Obstet Gynaecol India ; 73(Suppl 2): 284-286, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38143985
2.
Pediatr Crit Care Med ; 24(9): e409-e416, 2023 09 01.
Article in English | MEDLINE | ID: mdl-37125796

ABSTRACT

OBJECTIVES: Hyperferritinemia in the critical phase of dengue infections may correlate with severe dengue ( sd ) disease, and our primary objective was to examine the association between ferritin level on day 1 of PICU admission and 2009 World Health Organization (WHO) criteria for sd . Our secondary objective was outcome in relation to care. It is unclear whether immunomodulatory therapy during the critical phase may restore immune homeostasis and mitigate disease severity. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study of children with dengue 1 month to 16 years old with admission ferritin greater than or equal to 500 ng/mL requiring PICU admission. Demographics, clinical, and laboratory parameters, presence of the 2009 WHO sd criteria and outcomes were analyzed. Immunomodulatory therapy was used when there was persistent hyperinflammation beyond the critical phase of plasma leakage. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fifty-five patients were admitted in the critical phase of dengue with median (interquartile range) ferritin levels of 8,105 ng/mL (2,350-15,765 ng/mL). Patients with at least one WHO sd category had higher ferritin levels compared to those without any sd criteria, with the highest levels in eight patients with all three sd categories. In our cohort of 55, 52 patients (94%) recovered with standard supportive therapy. Recovery was associated with decreased ferritin levels that occurred in parallel with improved circulation and platelet counts; this included 22 of 24 patients with admission ferritin levels greater than or equal to 10,000 ng/mL and two with ferritin greater than 1,00,000 ng/mL. Immunomodulation was used in three patients with unremitting fever, persistent hyperferritinemia, and progressive multiple organ dysfunction beyond the critical phase, of whom two died. CONCLUSIONS: Hyperferritinemia in the critical phase of sd is associated with the number of 2009 WHO sd criteria present. Our data also indicate that many patients with sd recover well with supportive care.


Subject(s)
Hyperferritinemia , Severe Dengue , Child , Humans , Retrospective Studies , Ferritins , Platelet Count
3.
J Pediatr Intensive Care ; 12(2): 131-136, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37082464

ABSTRACT

Ventilation-induced diaphragm dysfunction can delay weaning from mechanical ventilation. Identifying the optimal time for extubation has always been a challenge for intensivists. Diaphragm ultrasound is gaining immense popularity as a surrogate to measure diaphragm function. We attempted to assess the utility of diaphragm function in predicting extubation success using point-of-care ultrasound examination. We conducted a prospective observational study in a single-center tertiary care pediatric intensive care unit (PICU). All children aged between 1 month and 16 years admitted to the PICU and who underwent invasive mechanical ventilation for more than 24 hours were included in the study. Children who died during mechanical ventilation and those with conditions affecting diaphragm function like neuromuscular disorders, pneumothorax, chronic respiratory diseases, and intraabdominal hypertension were excluded from the study. Diaphragm thickening fraction (DTf) was measured during spontaneous breathing trial and correlated to predict extubation success. We found that DTf is an independent predictor of extubation success. DTf more than or equal to 20% was associated with extubation success with a positive predictive value of 85%. The area under the curve for DTf showed good accuracy.

4.
Int J Diabetes Dev Ctries ; : 1-30, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36536953

ABSTRACT

Hypertension and diabetes mellitus (DM) are two of the leading lifestyle diseases in the Indian and South Asian populations that often co-exist due to overlapping pathophysiological factors. Obesity, insulin resistance, inflammation, and oxidative stress are thought to be some common pathways. Up to 50% of hypertensive cases in India are diagnosed with type 2 diabetes mellitus (T2DM), which defines the need for a comprehensive guideline for managing hypertension in diabetic patients. These RSSDI guidelines have been formulated based on consultation with expert endocrinologists in India and Southeast Asia, acknowledging the needs of the Indian population. Ambulatory blood pressure monitoring and office and home-based blood pressure (BP) monitoring are recommended for the early analysis of risks. Cardiovascular risks, end-organ damage, and renal disorders are the primary complications associated with diabetic hypertension that needs to be managed with the help of non-pharmacological and pharmacological interventions. The non-pharmacological interventions include the nutrition education of the patient to reduce the intake of salt, sodium, and trans fats and increase the consumption of nuts, fresh fruits, vegetables, and potassium-rich foods. It is also recommended to initiate 50 to 60 min of exercise three to four times a week since physical activity has shown to be more beneficial for hypertension control in Indian patients than dietary modulation. For the pharmacological management of hypertension in patients with T2DM, angiotensin II receptor blockers (ARBs) are recommended as the first line of therapy, demonstrating their superiority over other antihypertensive agents such as ACEi. However, most of the global hypertension guidelines recommend initiation with combination therapy to achieve better BP control in most patients and to reduce the risk of adverse events. For combination therapy, calcium channel blockers (CCBs) are recommended to be administered along with ARBs instead of beta-blockers or diuretics to avoid the risk of cardiovascular events and hyperglycaemia. Among the CCBs, novel molecules (e.g. cilnidipine) are recommended in combination with ARBs for better cardiovascular and reno-protection in diabetic hypertensive patients.

5.
Nat Prod Res ; 36(6): 1610-1615, 2022 Mar.
Article in English | MEDLINE | ID: mdl-33615940

ABSTRACT

Vanillin and its derivative, (4-((E)-(4-hydroxy-2-methylphenylimino) methyl)-2-methoxyphenol (MMP) were showed clear inhibition of violacein and pyocyanin at sub-MICs indicating a possible quorum quenching effect of both the compounds. MMP was able to inhibit the biofilm formation in Pseudomonas aeruginosa PAO1 at 125 µg/mL (p < 0.05), while vanillin at 250 µg/mL (p < 0.05) indicating that they act against quorum sensing regulated biofilm formation. The inhibition of biofilm was confirmed by visualization through fluorescence microscopy followed by docking analysis of molecules against quorum sensing activator proteins. Caenorhabditis elegans survival assay revealed that vanillin and MMP were able to increase survival of C. elegans from P. aeruginosa PAO1 infection. The study showed that the potent features of the MMP and vanillin in inhibiting the quorum sensing regulated virulence and biofilm, which was proved in C. elegans infection model as well as molecular docking studies.


Subject(s)
Pseudomonas aeruginosa , Quorum Sensing , Animals , Anti-Bacterial Agents/pharmacology , Benzaldehydes , Biofilms , Caenorhabditis elegans , Molecular Docking Simulation , Virulence Factors/metabolism
7.
Paediatr Int Child Health ; 40(2): 135-138, 2020 05.
Article in English | MEDLINE | ID: mdl-31891331

ABSTRACT

Acute kidney injury (AKI) is a neglected and least studied complication of dengue. AKI secondary to thrombotic thrombocytopenic purpura (TTP) in dengue is extremely rare and there are few case reports. A 2.5-year-old boy with dengue who developed TTP in the critical phase of illness is described. He presented with microangiopathic haemolysis, thrombocytopenia and AKI. Haemolytic uraemic syndrome (HUS)/TTP was suspected and he underwent seven cycles of plasma exchange along with renal replacement therapy, following which he made a complete recovery. Prompt recognition of renal complications in dengue fever and early initiation of appropriate renal replacement therapy along with plasma exchange are essential for a good outcome.Abbreviations: AKI, acute kidney injury; GCS, Glasgow coma scale; HUS, haemolytic uraemic syndrome; LDH, lactate dehydrogenase; NS1, non-structural protein 1; pRIFLE, paediatric risk, injury, failure, loss, end-stage renal disease; SLED, sustained low-efficiency dialysis; TMA, thrombotic microangiopathy; TTP, thrombotic thrombocytopenic purpura.


Subject(s)
Dengue/complications , Purpura, Thrombotic Thrombocytopenic/etiology , Child, Preschool , Humans , Male
8.
J Cardiovasc Echogr ; 26(1): 5-10, 2016.
Article in English | MEDLINE | ID: mdl-28465952

ABSTRACT

INTRODUCTION: Hepatic veins are the major linking vessels between systemic and portal circulation. Numerical and positional variation of the hepatic veins can play a significant role during surgical interventions on the liver. MATERIALS AND METHODS: Gross anatomical study regarding the number and arrangement pattern of hepatic veins was undertaken on 88 adult livers which were stored in 10% formalin after the regular dissection classes. RESULT: Six livers (7%) were found to be drained only by major hepatic veins, whereas 82 out of 88 livers (93%) had accessory (minor) hepatic veins. The total number of persistent hepatic veins ranged from 2 to 10 with the highest prevalence of four hepatic veins (35.2%) followed by 5 (19.3%) and 6 (17%). The presence of three major veins was seen in 45 (51%) livers while 41 (47%) livers had two major hepatic veins. Remaining two livers (2%) showed the presence of four major hepatic veins. In 95% specimens, the minor hepatic veins entered the inferior vena cava below the level of entry of major veins. In 2.5% cases, their entry point was above the major veins and in 2.5% cases, the entry point was below major veins. CONCLUSION: The data resulting from this study provides a clear idea about the number and drainage pattern of the hepatic veins into the liver. Knowledge of numerical and positional variations of hepatic veins could be useful in normal Doppler ultrasound hepatic vein flow velocities and their variation with respiration in healthy adults as comparable with the similar approach of superior vena cava.

9.
Indian J Surg ; 77(4): 313-21, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26702239

ABSTRACT

The therapeutic approach to congenital diaphragmatic hernia (CDH) has shifted from one of immediate repair to management of pulmonary hypertension, physiologic stabilization, and delayed surgical repair. Lung hypoplasia, remodeled pulmonary vasculature, and ventricular dysfunction all contribute to the high morbidity and mortality associated with CDH. In addition, genetic syndromes associated with CDH can increase the incidence of serious anomalies and hence impact survival. Prenatal and postnatal management of infants with CDH is challenging in the best of circumstances and need multidisciplinary teams for optimal outcomes. However, advances using ultrasound and fetal MRI can predict prognosis and survival and plan for postnatal management. Survival rates for patients with CDH have increased for the past decade with better management at resuscitation; implementation of gentle ventilation strategies; and medical management of pulmonary hypertension, physiologic stabilization, and extracorporeal membrane oxygenation. However, follow-up of these infants for long-term morbidities is essential for optimal outcomes after discharge.

11.
Quintessence Int ; 45(7): 577-84, 2014.
Article in English | MEDLINE | ID: mdl-24847496

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate the sitelevel plaque removal efficacy of four commercially available toothbrushes. The adjunctive benefit of dental floss on interproximal plaque removal was also evaluated. METHOD AND MATERIALS: This study was designed as a randomized examiner- blinded clinical study involving 60 subjects. The subjects were randomly divided into four groups of 15 participants each, and a particular branded toothbrush was allotted for each group. Brushing technique, toothpaste, and brushing time were standardized for all the subjects. The Turesky- Gilmore-Glickman modification of Quigley-Hein plaque index was used to evaluate plaque scores at baseline, and 1, 2, 3, and 4 weeks by one blinded examiner. After 2 weeks, the subjects were provided with dental floss to be used in conjunction with the toothbrush. Buccal, lingual, and interproximal plaque reduction percentages were computed and analyzed for statistical significance. RESULTS: The four toothbrushes showed similar plaque removal scores at the three sites, with no statistical significance (P > .05). The interproximal plaque removal scores of the four toothbrushes were the least at 2 weeks (25%) when compared with buccal (65%) and lingual (60%) percentage scores. The addition of dental floss significantly increased the interproximal plaque removal scores, with 4-week scores revealing 70% removal. CONCLUSION: These data revealed the lack of significance between the four toothbrushes studied, which is in line with previous studies. The addition of dental floss had a significant effect on the interproximal plaque removal, which could be crucial in the maintenance of gingival health.


Subject(s)
Dental Devices, Home Care , Dental Plaque , Toothbrushing/instrumentation , Humans , Single-Blind Method
13.
Exp Toxicol Pathol ; 64(7-8): 855-9, 2012 Nov.
Article in English | MEDLINE | ID: mdl-21478003

ABSTRACT

The hepatoprotective, curative and anti-oxidant properties of aqueous extract of Hybanthus enneaspermus (Violaceae) used against CCl4-induced liver damage in rats were investigated in the present study. Liver damage was induced by CCl4 (1 ml/kg i.p.), and silymarin was used as a standard drug to compare hepatoprotective, curative and antioxidant effects of the extract. Rats were treated with aqueous extract of H. enneaspermus at a dose of either 200 or 400 mg/kg after division into pre-treatment (once daily for 14 days before CCl4 intoxication) and post-treatment (2, 6, 24 and 48 h after CCl4 intoxication) groups. Pre-treatment and post-treatment with aqueous extract of H. enneaspermus showed significant hepatoprotection by reducing the aspartate transaminase, alanine transaminase, and alkaline phosphatase enzymatic activities and total bilirubin levels which had been raised by CCl4 administration. Pre- and post-treatment with aqueous extract significantly decreased hepatic lipid peroxidation as well as producing a corresponding increase in tissue total thiols. Post-treatment with aqueous extract improved ceruloplasmin levels. The histopathological examination of rat liver sections treated with aqueous extract confirms the serum biochemical observations. The present study results demonstrate the protective, curative and anti-oxidant effects of H. enneaspermus aqueous extract used against CCl4-induced hepatotoxicity in rats, and suggest a potential therapeutic use of H. enneaspermus as an alternative for patients with acute liver diseases.


Subject(s)
Antioxidants/therapeutic use , Chemical and Drug Induced Liver Injury/prevention & control , Liver/drug effects , Plant Extracts/therapeutic use , Violaceae/chemistry , Animals , Antioxidants/administration & dosage , Antioxidants/isolation & purification , Antioxidants/toxicity , Chemical and Drug Induced Liver Injury/etiology , Chemical and Drug Induced Liver Injury/pathology , Drug Administration Schedule , Female , Lipid Peroxidation/drug effects , Liver/enzymology , Liver/pathology , Liver Function Tests , Male , Plant Extracts/administration & dosage , Plant Extracts/isolation & purification , Plant Extracts/toxicity , Rats , Rats, Wistar , Silymarin/therapeutic use , Toxicity Tests, Acute
14.
J Appl Physiol (1985) ; 109(3): 677-84, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20616229

ABSTRACT

Aerosolized prostacyclin (PGI2) produces selective pulmonary vasodilation in patients with pulmonary hypertension (PH). The response to PGI2 may be increased by phosphodiesterase type 3 inhibitors such as milrinone. We studied the dose response effects of aerosolized PGI2 and aerosolized milrinone both alone and in combination on pulmonary and systemic hemodynamics in newborn lambs with Nomega-nitro-L-arginine methyl ester (L-NAME)-induced PH. We hypothesized that coaerosolization of PGI2 with milrinone would additively decrease pulmonary vascular resistance (PVR), prolong the duration of action of PGI2, and selectively dilate the pulmonary vasculature. Near-term lambs were delivered by C-section and instrumented and PH was induced by L-NAME (bolus 25 mg/kg; infusion 10 mg.kg(-1).h(-1)) and indomethacin. In the first set of experiments, PGI2 was aerosolized at random doses of 2, 20, 100, 200, 500, and 1,000 ng.kg(-1).min(-1) followed by milrinone at doses of 0.1, 1, and 10 microg.kg(-1).min(-1) over 10 min. In the second set of experiments, milrinone at 1 microg.kg(-1).min(-1) was aerosolized in combination with PGI2 at doses of 20, 100, and 200 ng.kg(-1).min(-1) over 10 min. Pulmonary arterial pressures (PAP) and PVR decreased significantly with increasing doses of aerosolized PGI2 and milrinone. The combination of PGI2 and milrinone significantly reduced PAP and PVR more than either of the drugs aerosolized alone. Addition of milrinone significantly increased the duration of action of PGI2. When aerosolized independently, PGI2 and milrinone selectively dilated the pulmonary vasculature but the combination did not. Milrinone enhances the vasodilatory effects of PGI2 on the pulmonary vasculature but caution must be exercised regarding systemic hypotension.


Subject(s)
Antihypertensive Agents/administration & dosage , Epoprostenol/administration & dosage , Hemodynamics/drug effects , Hypertension, Pulmonary/drug therapy , Milrinone/administration & dosage , Phosphodiesterase Inhibitors/administration & dosage , Pulmonary Circulation/drug effects , Vasodilator Agents/administration & dosage , Administration, Inhalation , Aerosols , Animals , Animals, Newborn , Blood Pressure/drug effects , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Therapy, Combination , Hypertension, Pulmonary/chemically induced , Hypertension, Pulmonary/physiopathology , Indomethacin , NG-Nitroarginine Methyl Ester , Sheep , Vascular Resistance/drug effects , Vasodilation/drug effects
15.
Pediatr Res ; 67(1): 66-71, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19745783

ABSTRACT

The optimal oxygen concentration for the resuscitation of term infants remains controversial. We studied the effects of 21 versus 100% oxygen immediately after birth, and also exposure for 24 h to 100% oxygen, on oxidant lung injury and lung antioxidant enzyme (AOE) activities in term newborn lambs. Lambs at 139 d gestation were delivered and ventilated with 21% (RAR) or 100% (OXR) for 30 min. A third group of newborn lambs were ventilated with 100% O2 for 24 h (OX24). Oxidized glutathione levels in whole blood were significantly different among the groups with lower values in the RAR group, and these values correlated highly with partial pressure of arterial oxygen (Pao2). The reduced to oxidized glutathione ratio was significantly different among the groups, the ratio decreasing with increasing oxygen exposure. Lipid hydroperoxide (LPO) activity was significantly higher in the OXR and OX24 groups. AOE activity was higher in the whole lung and in red cell lysate in the OX24 group. Increased myeloperoxidase (MPO) activity, percent neutrophils, and proteins in lung lavage suggested inflammation in the OX24 group after maximal oxygen exposure. We conclude that even relatively brief exposure of the lung to 100% oxygen increases systemic oxidative stress and lung oxidant injury in ventilated term newborn lambs.


Subject(s)
Animals, Newborn , Antioxidants/metabolism , Oxidative Stress , Oxygen Inhalation Therapy , Peroxidase/metabolism , Superoxide Dismutase/metabolism , Animals , Female , Pregnancy , Sheep
16.
Neonatology ; 96(3): 182-92, 2009.
Article in English | MEDLINE | ID: mdl-19365144

ABSTRACT

BACKGROUND: The optimal oxygen concentration for the resuscitation of premature infants remains controversial. OBJECTIVES: We studied the effects of 21 versus 100% oxygen at initial resuscitation and also the effects of 24-hour exposure to 100% oxygen on arterial blood gases, oxidant lung injury, activities of lung antioxidant enzymes (AOEs) and isolated pulmonary artery (PA) contractility in preterm newborn lambs. METHODS: Preterm lambs at 128 days' gestation (term = 145 days) were delivered and ventilated with 21 (RAR; n = 5) or 100% oxygen (OXR; n = 5) for the first 30 min of life. Subsequently, FiO2 was adjusted to maintain an arterial PO2 (PaO2) between 45 and 70 mm Hg for 24 h. A third group of lambs was mechanically ventilated with 100% oxygen for 24 h (OX24; n = 5). RESULTS: Oxidized glutathione levels in whole blood correlated highly with PaO2. Reduced to oxidized glutathione ratio was significantly different between the groups, the ratio increasing with decreasing oxygen exposure. The OX24 group had significantly higher activities of lipid hydroperoxide and myeloperoxidase and significantly lower activities of superoxide dismutase, catalase and glutathione peroxidase in the lung at 24 h. Activities of AOEs correlated inversely with alveolar PO2. PA contractility to norepinephrine and KCl was greater with increasing oxygen exposure. Pretreatment with superoxide dismutase and catalase significantly reduced PA contractility in the OXR and OX24 groups, but not in the RAR group. CONCLUSIONS: We conclude that ventilated premature lambs are unable to appropriately increase AOE activity in response to hyperoxia and that increasing exposure to oxygen aggravates systemic oxidant stress, oxidant lung injury and pulmonary arterial contractility in these lambs.


Subject(s)
Lung/drug effects , Oxidoreductases/metabolism , Oxygen/administration & dosage , Pulmonary Artery/drug effects , Vasoconstriction/drug effects , Animals , Animals, Newborn , Catalase/metabolism , Catalase/pharmacology , Disease Models, Animal , Down-Regulation , Drug Interactions , Gestational Age , Glutathione Disulfide/blood , In Vitro Techniques , Lipid Peroxides/metabolism , Lung/enzymology , Norepinephrine/pharmacology , Oxygen/blood , Potassium Chloride/pharmacology , Pulmonary Alveoli/physiology , Pulmonary Artery/enzymology , Respiration, Artificial , Resuscitation , Sheep , Superoxide Dismutase/metabolism , Superoxide Dismutase/pharmacology , Vasoconstriction/physiology
17.
Pediatr Crit Care Med ; 10(1): 106-12, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19057444

ABSTRACT

UNLABELLED: Prostacyclin is a pulmonary vasodilator and is produced by prostacyclin synthase and stimulates adenylate cyclase (AC) via the prostacyclin receptor (IP) to produce cAMP. Forskolin is a direct stimulant of AC. Phosphodiesterase 3 hydrolyzes cAMP and is inhibited by milrinone. OBJECTIVE: To characterize the prostacyclin-AC-cAMP pathway in the ovine ductal ligation model of persistent pulmonary hypertension of the newborn (PPHN). SETTING: University-based laboratory animal facility. SUBJECTS: Lambs delivered to time-dated pregnant ewes. INTERVENTIONS: Fifth generation pulmonary arteries (PA) and lung parenchyma were isolated from control fetal lambs (n = 8) and fetal lambs with PPHN induced by antenatal ductal ligation (n = 9). We studied relaxation responses to various agonists (milrinone, forskolin, prostacyclin, and iloprost, a prostacyclin analog) that increase cAMP in PA after half-maximal constriction with norepinephrine and pretreatment with propranolol +/- indomethacin. Lung protein levels of prostacyclin synthase, IP, AC2, and phosphodiesterase 3A were analyzed by Western blot and cAMP by enzyme-linked immunoassay. MAIN RESULTS: Milrinone relaxed control and PPHN PA and pretreatment with indomethacin significantly impaired this response. Relaxation to milrinone, prostacyclin, and iloprost were significantly impaired in PA from PPHN lambs. Pretreatment with milrinone markedly enhanced relaxation to prostacyclin and iloprost in PPHN PA, similar to relaxation in control PA. Relaxation to forskolin was similar in control and PPHN PAs indicating normal AC activity. Protein levels of prostacyclin synthase and IP were decreased in PPHN lungs compared with control, but AC2, cAMP, and phosphodiesterase 3A remained unchanged. CONCLUSIONS: Prostacyclin and iloprost are dilators of PAs from PPHN lambs and their effect is enhanced by milrinone. This combination therapy may be an effective strategy in the management of patients with PPHN.


Subject(s)
Epoprostenol/administration & dosage , Hypertension, Pulmonary/drug therapy , Iloprost/administration & dosage , Milrinone/administration & dosage , Pregnancy, Animal , Pulmonary Artery/drug effects , Animals , Animals, Newborn , Blotting, Western , Disease Models, Animal , Drug Interactions , Drug Therapy, Combination , Enzyme-Linked Immunosorbent Assay , Epoprostenol/metabolism , Female , Hypertension, Pulmonary/congenital , Male , Pregnancy , Probability , Pulmonary Artery/physiology , Random Allocation , Reference Values , Sensitivity and Specificity , Sheep, Domestic , Vasodilation/drug effects
18.
J Biol Chem ; 283(51): 35869-77, 2008 Dec 19.
Article in English | MEDLINE | ID: mdl-18930922

ABSTRACT

The oral cavity is an environment challenged by a large variety of pathogens. Consequently, the antimicrobial peptides expressed in that environment are interesting as they evolved to defend against a broad spectrum of bacteria and fungi. Here we report the discovery of new alpha-defensins from rhesus macaque oral mucosa and determine the first alpha-defensin structure from that species. The new peptides were identified by sequencing of reverse transcriptase-PCR products obtained from oral mucosal tissues, disclosing three mucosal alpha-defensins, termed rhesus macaque oral alpha-defensins (ROADs). The peptide corresponding to fully processed ROAD-1 was synthesized, subjected to folding/oxidation conditions, and purified. ROAD-1 was active against Staphylococcus aureus, Escherichia coli, and Candida albicans in a concentration-dependent manner. We determined the structure of ROAD-1 using NMR spectroscopy and find that the synthetic peptide adopts the canonical disulfide pairing and alpha-defensin fold. The antimicrobial mechanism of defensins has been correlated with their ability to disrupt and permeabilize the cell envelope, activities that depend on the surface features of the folded peptide. Although ROAD-1 maintains the defensin fold, the oral defensin displays distinct surface features when compared with other alpha-defensin structures.


Subject(s)
Anti-Infective Agents/chemical synthesis , Anti-Infective Agents/pharmacology , Candida albicans/growth & development , Escherichia coli/growth & development , Staphylococcus aureus/growth & development , alpha-Defensins/genetics , alpha-Defensins/pharmacology , Animals , Anti-Infective Agents/immunology , Macaca mulatta , Mouth Mucosa/immunology , Protein Folding , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Structure-Activity Relationship , alpha-Defensins/chemical synthesis , alpha-Defensins/immunology
19.
Pediatr Res ; 62(3): 313-8, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17622960

ABSTRACT

The effect of resuscitation with varying levels of O2 on pulmonary hemodynamics at birth is not well known. We hypothesized that the decrease in pulmonary vascular resistance (PVR) and subsequent response to pulmonary vasoconstrictors and vasodilators will differ following resuscitation with 21%, 50%, or 100% O2 for 30 min at birth in normal term lambs. Lambs at 141 d gestation were delivered by cesarean section and ventilated with 21% (21% Res; n=6), 50% (50% Res; n=6), or 100% 02 (100% Res; n=7) for 30 min followed by ventilation with 21% O2 in all three groups. A greater decrease in PVR was seen with 50% and 100% O2 ventilation than with 21% O2 (0.21 +/- 0.02, 0.21 +/- 0.02, and 0.34 +/- 0.05 mm Hg/mL/min/kg, respectively). Subsequent pulmonary vasoconstriction to hypoxia (10% O2) and the thromboxane,analog U46619 (0.5 and 1 mcirog/kg/min) was similar in all three groups. After inducing a stable elevation in PVR with U46619, impaired pulmonary vasodilation to inhaled NO (59 +/- 4, 65 +/- 4, and 74 +/- 5% of baseline PVR with 21, 50, and 100%Res, respectively) and acetylcholine infusion (67 +/- 8, 75 +/- 6, and 87 +/- 4% of baseline PVR with 21, 50, and 100%Res, respectively) and rebound pulmonary hypertension following their withdrawal were observed in the 100%Res group. We conclude that, while ventilation with 100% O2 at birth results in a greater initial decrease in PVR, subsequent pulmonary vasodilation to NO/acetylcholine is impaired.


Subject(s)
Hemodynamics , Oxygen Inhalation Therapy , Oxygen/administration & dosage , Resuscitation , Vascular Resistance , 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology , Acetylcholine/pharmacology , Animals , Female , Gestational Age , Lung/anatomy & histology , Lung/physiology , Nitric Oxide/administration & dosage , Nitric Oxide/metabolism , Oxygen/metabolism , Pregnancy , Pulmonary Gas Exchange , Random Allocation , Respiration , Sheep, Domestic , Vascular Resistance/drug effects , Vascular Resistance/physiology , Vasoconstriction/drug effects , Vasoconstrictor Agents/pharmacology , Vasodilation/drug effects , Vasodilator Agents/pharmacology
20.
Am J Physiol Lung Cell Mol Physiol ; 292(6): L1370-84, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17293375

ABSTRACT

Failed alveolar formation and excess, disordered elastin are key features of neonatal chronic lung disease (CLD). We previously found fewer alveoli and more elastin in lungs of preterm compared with term lambs that had mechanical ventilation (MV) with O(2)-rich gas for 3 wk (MV-3 wk). We hypothesized that, in preterm more than in term lambs, MV-3 wk would reduce lung expression of growth factors that regulate alveolarization (VEGF, PDGF-A) and increase lung expression of growth factors [transforming growth factor (TGF)-alpha, TGF-beta(1)] and matrix molecules (tropoelastin, fibrillin-1, fibulin-5, lysyl oxidases) that regulate elastin synthesis and assembly. We measured lung expression of these genes in preterm and term lambs after MV for 1 day, 3 days, or 3 wk, and in fetal controls. Lung mRNA for VEGF, PDGF-A, and their receptors (VEGF-R2, PDGF-Ralpha) decreased in preterm and term lambs after MV-3 wk, with reduced lung content of the relevant proteins in preterm lambs with CLD. TGF-alpha and TGF-beta(1) expression increased only in lungs of preterm lambs. Tropoelastin mRNA increased more with MV of preterm than term lambs, and expression levels remained high in lambs with CLD. In contrast, fibrillin-1 and lysyl oxidase-like-1 mRNA increased transiently, and lung abundance of other elastin-assembly genes/proteins was unchanged (fibulin-5) or reduced (lysyl oxidase) in preterm lambs with CLD. Thus MV-3 wk reduces lung expression of growth factors that regulate alveolarization and differentially alters expression of growth factors and matrix proteins that regulate elastin assembly. These changes, coupled with increased lung elastase activity measured in preterm lambs after MV for 1-3 days, likely contribute to CLD.


Subject(s)
Bronchopulmonary Dysplasia/metabolism , Lung/embryology , Lung/metabolism , Tropoelastin/genetics , Tropoelastin/metabolism , Animals , Animals, Newborn , Bronchopulmonary Dysplasia/physiopathology , Bronchopulmonary Dysplasia/therapy , Female , Gene Expression Regulation, Developmental , Gestational Age , Humans , Infant, Newborn , Oxygen/pharmacology , Pancreatic Elastase/metabolism , Peroxidase/metabolism , Platelet-Derived Growth Factor/metabolism , Pregnancy , Receptor, Platelet-Derived Growth Factor alpha/metabolism , Respiration, Artificial , Serine/metabolism , Sheep , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor Receptor-2/genetics , Vascular Endothelial Growth Factor Receptor-2/metabolism
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