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Comparison of the Sealing Ability of MTA-Angelus, Biodentine and CEM Cement in the Repair of Large Furcal Perforations-A Bacterial Leakage Study. J Clin Diagn Res 2019. [DOI: 10.7860/jcdr/2019/38476.12503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Incidence of Postoperative Pain after Single Visit and Two Visit Root Canal Therapy: A Randomized Controlled Trial. J Clin Diagn Res 2016; 10:ZC09-12. [PMID: 27437339 DOI: 10.7860/jcdr/2016/16465.7724] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/16/2015] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Root Canal Treatment (RCT) has become a mainstream procedure in dentistry. A successful RCT is presented by absence of clinical signs and symptoms in teeth without any radiographic evidence of periodontal involvement. Completing this procedure in one visit or multiple visits has long been a topic of discussion. AIM To evaluate the incidence of postoperative pain after root canal therapy performed in single visit and two visits. MATERIAL AND METHODS An unblinded/ open label randomized controlled trial was carried out in the endodontic department of the Dental Institute, where 78 patients were recruited from the regular pool of patients. A total of 66 maxillary central incisors requiring root canal therapy fulfilled the inclusion and exclusion criteria. Using simple randomization by biased coin randomization method, the selected patients were assigned into two groups: group A (n=33) and group B (n=33). Single visit root canal treatment was performed for group A and two visit root canal treatment for group B. Independent sample t-test was used for statistical analysis. RESULTS Thirty three patients were allotted to group A where endodontic treatment was completed in single visit while 33 patients were allotted to group B where endodontic treatment was completed in two visits. One patient dropped-out from Group A. Hence in Group A, 32 patients were analysed while in Group B, 33 patients were analysed. After 6 hours, 12 hours and 24 hours of obturation, pain was significantly higher in Group B as compared to Group A. However, there was no significant difference in the pain experienced by the patients 48 hours after treatment in both the groups. CONCLUSION Incidence of pain after endodontic treatment being performed in one-visit or two-visits is not significantly different.
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Biochemical Evaluation of the Hypoglycemic Effects of Extract and Fraction of Cassia fistula Linn. in Alloxan-induced Diabetic Rats. Indian J Pharm Sci 2013; 75:427-34. [PMID: 24302797 PMCID: PMC3831724 DOI: 10.4103/0250-474x.119823] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 04/12/2013] [Accepted: 05/08/2013] [Indexed: 11/23/2022] Open
Abstract
Various extracts of flowers of Cassia fistula Linn (Leguminosae) such as petroleum ether (60-80°), chloroform, acetone, ethanol, aqueous, and crude aqueous extracts and two fractions of ethanol extract were tested for antihyperglycemic activity in glucose-overloaded hyperglycemic rats. The effective antihyperglycemic extracts and fraction were tested for their hypoglycemic activity at two dose levels, 200 and 400 mg/kg, respectively. To confirm their utility in higher models, the effective extracts and fraction of C. fistula were subjected to antidiabetic study in an alloxan-induced diabetic model at two dose levels, 200 and 400 mg/kg, respectively. Biochemical parameters like glucose, urea, creatinine, serum cholesterol, serum triglyceride, high-density lipoprotein, low-density lipoprotein, hemoglobin, and glycosylated hemoglobin were also assessed in experimental animals. The petroleum ether and ethanol extracts of C. fistula and the water-soluble fraction of ethanol extract were found to exhibit significant antihyperglycemic activity. The extracts, at the given doses, did not produce hypoglycemia in fasted normal rats, and the fraction exhibited weak hypoglycemic effect after 2 h of the treatment. Treatment of diabetic rats with ethanol extract and water-soluble fraction of this plant restored the elevated biochemical parameters significantly (P<0.05) to the normal level. No activity was found in the petroleum ether extract of the plant. Comparatively, the water-soluble fraction of ethanol extract was found to be more effective than the ethanol extract, and the activity was comparable with that of the standard, glibenclamide (5 mg/kg).
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Antiovulatory and estrogenic activity of Plumbago rosea leaves in female albino rats. Indian J Pharmacol 2011; 41:273-7. [PMID: 20407559 PMCID: PMC2846502 DOI: 10.4103/0253-7613.59927] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 04/08/2009] [Accepted: 12/23/2009] [Indexed: 11/22/2022] Open
Abstract
Objective: To evaluate the effect of petroleum ether (60–80°), chloroform, acetone, ethanol and aqueous extracts of Plumbago rosea leaves on the estrous cycle and to identify the estrogenic activity of active acetone and ethanol extracts in female albino rats. Methods: Plant extracts were tested for their effect on the estrous cycle at two dose levels: 200 and 400 mg/kg, respectively. The effective acetone and ethanol extracts were further studied on estrogenic activity in rats. Histological studies of the uterus were carried out to confirm their estrogenic activity. Results: The acetone and ethanol extracts were most effective in interrupting the normal estrous cycle of the rats (P<0.05, <0.01, <0.001). These later exhibited prolonged diestrous stage of the estrous cycle with consequent temporary inhibition of ovulation. The antiovulatory activity was reversible on discontinuation of treatment. Both the extracts showed significant estrogenic and antiestrogenic activity. Conclusion: The acetone and ethanolic extracts of P. rosea leaves have an antifertility activity.
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Antidiabetic activity of flower buds of Michelia champaca Linn. Indian J Pharmacol 2011; 40:256-60. [PMID: 21279181 PMCID: PMC3025142 DOI: 10.4103/0253-7613.45151] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 07/30/2008] [Accepted: 11/22/2008] [Indexed: 11/11/2022] Open
Abstract
Objective: To identify the antihyperglycemic activity of various extracts, petroleum ether (60-80°), chloroform, acetone, ethanol, aqueous and crude aqueous, of the flower buds of Michelia champaca, and to identify the antidiabetic activity of active antihyperglycemic extract. Materials and Methods: Plant extracts were tested for antihyperglycemic activity in glucose overloaded hyperglycemic rats. The effective antihyperglycemic extract was tested for its hypoglycemic activity at two-dose levels, 200 and 400 mg/kg respectively. To confirm its utility in the higher model, the effective extract of M. champaca was subjected to antidiabetic study in alloxan induced diabetic model at two dose levels, 200 and 400 mg/kg respectively. The biochemical parameters, glucose, urea, creatinine, serum cholesterol, serum triglyceride, high density lipoprotein, low density lipoprotein, hemoglobin and glycosylated hemoglobin were also assessed in the experimental animals. Results: The ethanolic extract of M. champaca exhibited significant antihyperglycemic activity but did not produce hypoglycemia in fasted normal rats. Apart from this extract, the crude aqueous and petroleum ether extracts were found active only at the end of the first hour. Treatment of diabetic rats with ethanolic extract of this plant restored the elevated biochemical parameters significantly (P<0.05) (P<0.01) and the activity was found dose dependent. Conclusion: This study supports the traditional claim and the ethanolic extract of this plant could be added in traditional preparations for the ailment of various diabetes-associated complications.
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The Woes of Waiting Wives: Psychosocial Battle at Homefront. Med J Armed Forces India 2011; 67:58-63. [PMID: 27365763 DOI: 10.1016/s0377-1237(11)80016-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 06/07/2010] [Indexed: 11/19/2022] Open
Abstract
Few studies on stress have been carried out in soldiers and other paramilitary forces deployed in operational situations because of the security concerns, practical difficulties of conducting combat psychiatric studies and various other reasons. Studies on their families, who safeguard the family interests, during the period of absence of soldiers, have been even fewer. Significant contributions of researchers in this field were reviewed and suitably interpreted. Analysis revealed various types of stress and the multiple coping methods being practiced. It also highlighted various preventive and remedial measures being undertaken by waiting wives and their children. There is a need to understand and address the psychosocial issues of these families.
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Bioassay-guided isolation of anti-inflammatory and antinociceptive compound from Plumbago zeylanica leaf. PHARMACEUTICAL BIOLOGY 2010; 48:381-387. [PMID: 20645715 DOI: 10.3109/13880200903156424] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Plumbago zeylanica Linn. (Plumbaginaceae) is used in the treatment of various inflammatory ailments in traditional medicines. In order to validate these ethnobotanical practices, the anti-inflammatory and antinociceptive activities of various leaf extracts (petroleum ether (60-80 degrees ), chloroform, acetone, ethanol, and aqueous) were studied using in vivo experimental models at two dose levels (200 and 400 mg/kg, p.o.). Anti-inflammatory activity was tested using the carrageenan induced rat hind paw edema method while analgesic activity was studied using the hot plate and formalin induced models. Diclofenac (100 mg/ kg) was used as the reference standard in both anti-inflammatory and analgesic models and morphine (10 mg/ kg, i.p.) was used as the reference standard in the formalin induced analgesic model. The acetone extract significantly (p < 0.01) reduced inflammation in the rats when compared to the control group. As for the analgesia effect, the acetone and petroleum ether extracts significantly (p < 0.01) decreased the pain stimulus only in the later phase of the formalin test, suggesting that the drug could be peripherally acting. Bioassay-guided fractionation of the acetone extract led to the isolation and identification of plumbagin. Structure elucidation of plumbagin confirmed it as 5-hydroxy-2-methyl-1,4-naphthoquinone, a naphthaquinone derivative, through spectral techniques.
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Antidiabetic activity of aqueous extract and non polysaccharide fraction of Cynodon dactylon Pers. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2008; 46:660-667. [PMID: 18949896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Petroleum ether (60 degrees-80 degrees C), chloroform, acetone, ethanol, aqueous and crude hot water extracts of the whole plant of C. dactylon and the two fractions of aqueous extract were tested for antihyperglycaemic activity in glucose overloaded hyperglycemic rats and in alloxan induced diabetic model at two-dose levels, 200 and 400 mg/kg (po) respectively. The aqueous extract of C. dactylon and the non polysaccharide fraction of aqueous extract were found to exhibit significant antihyperglycaemic activity and only the non polysaccharide fraction was found to produce hypoglycemia in fasted normal rats. Treatment of diabetic rats with aqueous extract and non polysaccharide fraction of the plant decreased the elevated biochemical parameters, glucose, urea, creatinine, serum cholesterol, serum triglyceride, high density lipoprotein, low density lipoprotein, haemoglobin and glycosylated haemoglobin significantly. Comparatively, the non polysaccharide fraction of aqueous extract was found to be more effective than the aqueous extract.
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Investigation of PEGylated derivatives of rosin as sustained release film formers. AAPS PharmSciTech 2008; 9:105-11. [PMID: 18446469 PMCID: PMC2976905 DOI: 10.1208/s12249-007-9025-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Accepted: 10/31/2007] [Indexed: 11/30/2022] Open
Abstract
The purpose of the present study was to investigate the potential use of two PEGylated derivatives of rosin (PD) as sustained release film forming materials. The derivatives differed chemically by their acid numbers--PD-1 with 120.93 and PD-2 with 88.19. The derivative films were characterized for surface morphology, water uptake-weight loss, angle of contact, water vapor transmission rate, mechanical properties and permeability study. Dissolution of diclofenac sodium (DS) and propranolol hydrochloride (PHL) as model drugs was studied from coated pellets. The films of derivatives with and without plasticizers were smooth and continuous. PD-2 films developed greater numbers of pores when in contact with phosphate buffer pH 6.8. The low weight loss, low angles of contact and high water vapor transmission rate of PD-2 films were related to presence of higher concentration of PEG esters. Higher tensile strength and percent elongation of PD-2 films was due to greater degree of internal plasticization of the derivative. The permeability of films to model drugs propranolol hydrochloride and diclofenac sodium was inversely proportional to the film thickness and dibutyl phthalate concentration in them; the permeability being greatest in PD-2 films containing 10% PEG 200. Dissolution rate of propranolol hydrochloride was higher from the coated pellets. The dissolution data followed zero order, Baker-Lonsdale equation and Hixon-Crowell equation of release kinetics with high correlation coefficients. The mechanism of drug release from these coated systems however followed class II transport (n > 1.0). The derivatives investigated could successfully retard release of the model drugs and offers an alternative to the conventionally used polymers.
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Evaluation of gum damar as a novel microencapsulating material for ibuprofen and diltiazem hydrochloride. Indian J Pharm Sci 2007. [DOI: 10.4103/0250-474x.33154] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Gum copal and gum damar: Novel matrix forming materials for sustained drug delivery. Indian J Pharm Sci 2006. [DOI: 10.4103/0250-474x.22964] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
Repair of a large diaphragmatic defect in congenital diaphragmatic hernia (CDH) and eventration of the diaphragm (DE) is difficult, especially when this is an unexpected finding at surgery. A patch of synthetic material may not be available at short notice, especially in developing countries. We describe the repair of nine such defects by using an abdominal muscle flap comprising the transversus abdominis and internal oblique muscles based on the intercostal and subcostal vessels. Although reports of similar flap repairs have been published in the literature [1-5], these employed a subcostal incision for abdominal entry, which we believe jeopardizes the flap's vascularity. Thus, we prefer to use an upper abdominal midline incision for abdominal entry in all cases of CDH and DE.
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Abstract
AIMS The outcome of in-hospital resuscitation following cardiac arrest depends on many factors related to the patient, the environment and the extent of resuscitation efforts. The aim of the present study was to determine predictors of successful resuscitation and survival to -hospital discharge following in-hospital cardiac arrest and to assess functional outcomes of survivors (cerebral performance scores). METHODS Medical records of adult patients sustaining in-hospital cardiac arrest between June 2001 and January 2003 were reviewed. Successful resuscitation was defined as the return of spontaneous circulation at the completion of resuscitative efforts, irrespective of degree of inotropic/vasopressor support. Thirty demographic and clinical variables were analysed to determine predictors of successful resuscitation and in-hospital survival. RESULTS In 105 patients with cardiac arrest, 46 patients (44%) were successfully resuscitated and 22 (21%) survived to hospital discharge. Predictors of successful resuscitation included a primary cardiac admission diagnosis, monitoring at the time of the arrest, a longer duration of resuscitation and the absence of the need for endotracheal intubation. Patients with ventricular tachycardia/fibrillation were more likely to survive to hospital discharge than those with asystolic or pulseless electrical activity (45 vs 12 vs 20%, P = 0.01). The sole independent predictor of survival to hospital discharge was the absence of the need for endotracheal intubation (odds ratio 0.14, 95% confidence interval 0.02-0.88, P < 0.01). The majority of survivors (73%) had normal cerebral performance scores. CONCLUSIONS Identification of predictors of successful resuscitation following cardiac arrest is important for risk stratification. Ongoing appraisal of in-hospital cardiac arrests through a multicentre registry could improve clinical outcomes.
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Hepatoprotective activity of Haridradi ghrita on carbon tetrachloride-induced liver damage in rats. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2003; 41:1447-51. [PMID: 15320500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Haridradi ghrita, a ghee based polyherbal formulation, (50, 100, 200 and 300 mg/kg) significantly lowered marker enzymes (SGPT, SGOT, ALP) and bilirubin in serum and liver peroxide, superoxide dismutase and catalase in liver homogenate following CCl4 (0.7 ml/kg, ip) toxicity. The protective effect was further supported by reversal of CCl4 induced histological changes. The results demonstrate significant hepatoprotective action of H. ghrita in CCl4 damaged rats.
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Abstract
This study was designed to investigate two rosin-based polymers (R-1 and R-2) for their in vitro and in vivo biodegradation behavior. The in vitro hydrolytic degradation was carried out in buffer solutions of pH 4.4, 7.4, and 10.4 at 37 degrees C. Enzymatic degradation was studied using enzymes lipase, pancreatine, and pectinase. Free films of the two polymers were subcutaneously implanted in rabbits for the in vivo biodegradation. The extent of degradation was determined quantitatively by weight loss and was followed qualitatively by scanning electron microscopy. The extent and the rate of degradation was better in vivo than in vitro. The polymers showed poor enzymatic degradation and a highly pH-dependent hydrolytic degradation.
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Abstract
The film-forming and coating properties of a new biomaterial, hydrogenated rosin (HR), is investigated in the present communication. Films produced by casting method are studied for mechanical, (tensile strength, elongation, and Young's modulus), water vapor transmission, and moisture absorption characteristics. Type of plasticizer and its concentration were observed to play an important role in modifying the film characteristics. Dibutyl sebacate (DBS), a hydrophobic plasticizer, was found to be suitable for development of flexible and smooth films. Film formulations plasticized with DBS were investigated for coating the drug layered nonpareil seeds where plasticization facilitated development of smooth and uniformly coated pellets. The increase in coat buildup, however, did not sustain the drug release significantly. The studies conclude that HR films promise utility as moisture-protective hydrophobic, film-coating materials.
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Abstract
Rosin-based polymers (R-1 and R-2) were synthesized and characterized for physicochemical properties, molecular weight (Mw), polydispersity (Mw/Mn), glass transition temperature (Tg), and thermogravimetry (TGA). Films of the polymers were cast on a mercury substrate by solvent evaporation technique. Free films were characterized for surface topography by scanning electron microscopy (SEM), water vapor transmission rate (WVTR), tensile strength, percentage elongation, and modulus of elasticity. The polymers were further evaluated as film coating materials by evaluating drug release from coated pellets with diclofenac sodium as a model drug. Drug was loaded on non-pareil seeds by a solution-layering technique and coated with varying concentrations of polymer solutions. Sustained release of the drug was observed from coated pellets. The newly synthesized rosin-based polymers promise considerable utility for pharmaceutical coating.
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Changes in nutritional status and morbidity over time among pre-school children from slums in Pune, India. Indian Pediatr 2000; 37:1060-71. [PMID: 11042704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVE To investigate changes in nutritional status and morbidity over time among pre-school slum children. DESIGN Longitudinal. METHODS Children in the age group of 0-5 years from three slums in Pune (n = 845) were studied for a period of two years. Measurement of weight (up to 20 g) and height (up to 0.1 cm), morbidity (in last 7 days) and clinical assessment was undertaken once every four months. RESULTS Peak prevalence of malnutrition was observed around 18 months and shorter period (3.5 months) of exclusive breastfeeding was probably responsible. Morbidity was generally higher in rainy season and was associated with wasting but not stunting. Gastrointestinal illness and fever contributed 50% of total morbidity days. Higher morbidity affected significantly growth velocities in weight throughout pre-school age. Height velocities were significantly low upto three years of age but there appeared no scope for catch-up growth as velocities remained similar thereafter. Higher morbidity in younger children (less than 2 years) led to deterioration of nutritional status over time in 30% to 50% children. CONCLUSION Shorter period of exclusive breastfeeding results in undernutrition at an early age among slum children. Morbidity further deteriorates the nutritional status
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Undernutrition and adolescent growth among rural Indian boys. Indian Pediatr 1999; 36:145-56. [PMID: 10713808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
OBJECTIVE To evaluate impact of undernutrition on various adolescent growth parameters among rural Indian boys. DESIGN Adolescent boys covering 8-18 yr age group were observed longitudinally for a period of 3 years. SETTING Adolescent boys (n=673) from seven different villages within 30 to 40 km from Pune were studied. METHOD Six monthly measurements on weight (upto 50 g) and height (upto 0.1 cm) were recorded and age assessment was done from school records with reasonable accuracy. RESULTS Stunted and underweight boys were lighter (by 4 kg) and shorter (by 8 cm) at 10 yr age compared to their normal counterparts but this difference increased to 12 kg and 10 cm respectively by adulthood. Undernourished boys however, revealed significant height gains at later ages especially beyond 14+ yr, compared to normals suggesting slow, gradual but continual growth. Undernutrition delayed age at take-off and age at PHV by about 2 yr, and lowered attained height at PHV (by 5 cm) and adult height (by 7 cm). CONCLUSION Normal and maluourished children from the same rural community show wide differences in their adolescent growth performance. Nutritional deprivation thus seems to affect almost all growth parameters and final adult size too.
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The paramyxovirus fusion protein forms an extremely stable core trimer: structural parallels to influenza virus haemagglutinin and HIV-1 gp41. Mol Membr Biol 1999; 16:11-9. [PMID: 10332733 DOI: 10.1080/096876899294715] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The paramyxovirus fusion (F) protein mediates membrane fusion. The biologically active F protein consists of a membrane distal subunit F2 and a membrane anchored subunit F1. A highly stable structure has been identified comprised of peptides derived from the simian virus 5 (SV5) F1 heptad repeat A, which abuts the hydrophobic fusion peptide (peptide N-1), and the SV5 F1 heptad repeat B, located 270 residues downstream and adjacent to the transmembrane domain (peptides C-1 and C-2). In isolation, peptide N-1 is 47% alpha-helical and peptide C-1 and C-2 are unfolded. When mixed together, peptides N1 + C1 form a thermostable (Tm > 90 degrees C), 82% alpha-helical, discrete trimer of heterodimers (mass 31,300 M(r)) that is resistant to denaturation by 2% SDS at 40 degrees C. The authors suggest that this alpha-helical trimeric complex represents the core most stable form of the F protein that is either fusion competent or forms after fusion has occurred. Peptide C-1 is a potent inhibitor of both the lipid mixing and aqueous content mixing fusion activity of the SV5 F protein. In contrast, peptide N-1 inhibits cytoplasmic content mixing but not lipid mixing, leading to a stable hemifusion state. Thus, these peptides define functionally different steps in the fusion process. The parallels among both the fusion processes and the protein structures of paramyxovirus F proteins, HIV gp41 and influenza virus haemagglutinin are discussed, as the analogies are indicative of a conserved paradigm for fusion promotion among fusion proteins from widely disparate viruses.
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Membrane fusion promoted by increasing surface densities of the paramyxovirus F and HN proteins: comparison of fusion reactions mediated by simian virus 5 F, human parainfluenza virus type 3 F, and influenza virus HA. J Virol 1998; 72:7745-53. [PMID: 9733810 PMCID: PMC110082 DOI: 10.1128/jvi.72.10.7745-7753.1998] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The membrane fusion reaction promoted by the paramyxovirus simian virus 5 (SV5) and human parainfluenza virus type 3 (HPIV-3) fusion (F) proteins and hemagglutinin-neuraminidase (HN) proteins was characterized when the surface densities of F and HN were varied. Using a quantitative content mixing assay, it was found that the extent of SV5 F-mediated fusion was dependent on the surface density of the SV5 F protein but independent of the density of SV5 HN protein, indicating that HN serves only a binding function in the reaction. However, the extent of HPIV-3 F protein promoted fusion reaction was found to be dependent on surface density of HPIV-3 HN protein, suggesting that the HPIV-3 HN protein is a direct participant in the fusion reaction. Analysis of the kinetics of lipid mixing demonstrated that both initial rates and final extents of fusion increased with rising SV5 F protein surface densities, suggesting that multiple fusion pores can be active during SV5 F protein-promoted membrane fusion. Initial rates and extent of lipid mixing were also found to increase with increasing influenza virus hemagglutinin protein surface density, suggesting parallels between the mechanism of fusion promoted by these two viral fusion proteins.
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A core trimer of the paramyxovirus fusion protein: parallels to influenza virus hemagglutinin and HIV-1 gp41. Virology 1998; 248:20-34. [PMID: 9705252 DOI: 10.1006/viro.1998.9242] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The paramyxovirus fusion (F) protein mediates membrane fusion. The biologically active F protein consists of a membrane distal subunit, F2, and a membrane-anchored subunit, F1. We have identified a highly stable structure composed of peptides derived from the F1 heptad repeat A, which abuts the hydrophobic fusion peptide (peptide N-1), and the F1 heptad repeat B, located 270 residues downstream and adjacent to the transmembrane domain (peptides C-1 and C-2). In isolation, peptide N-1 is 47% alpha-helical and peptide C-1 and C-2 are unfolded. When mixed together, peptides N1 + C1 form a thermostable (Tm >90 degreesC), 82% alpha-helical, discrete trimer of heterodimers (mass 31,300 Mr) that is resistant to denaturation by 2% SDS at 40 degreesC. We suggest that this alpha-helical trimeric complex represents the core most stable form of the F protein that either is fusion competent or forms after fusion has occurred. Peptide C-1 is a potent inhibitor of both the lipid mixing and the aqueous content mixing fusion activity of the SV5 F protein. In contrast, peptides N-1 and N-2 inhibit cytoplasmic content mixing but not lipid mixing, leading to a stable hemifusion state. Thus, these peptides define functionally different steps in the fusion process. The parallels among both the fusion processes and the protein structures of paramyxovirus F proteins, HIV gp41, and influenza virus hemagglutinin are discussed, as the analogies are indicative of a conserved paradigm for fusion promotion among fusion proteins from widely disparate viruses.
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Abstract
Terbutaline sulphate microcapsules were prepared by coacervation-phase separation (solvent evaporation) technique using ethyl cellulose as a coating material. Acetone, ethyl alcohol and isopropyl alcohol were employed as solvents for coating material. Microcapsules were evaluated for their drug content, particle size distribution (microscopic method), flow properties, bulk density, in vitro dissolution, drug release kinetics and surface characteristics (scanning electron microscopy).
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Abstract
Propranolol hydrochloride microcapsules were prepared by the coacervation-phase separation induced by solvent evaporation technique. The cellulose acetate phthalate was employed as coating material alone and in combination with ethyl cellulose. The prepared microcapsules were evaluated for their drug content, particle size distribution (microscopic method), flow properties, bulk density, in vitro dissolution and drug release kinetics.
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Abstract
Microcapsules of salbutamol sulphate were prepared using cellulose acetate phthalate as a coating material and by the coacervation phase separation (solvent evaporation) technique for obtaining sustained action. Prepared microcapsules were evaluated for their drug content, physical properties, release characteristics and stability. The effect of coat to core ratio on release pattern was studied and it was found that microcapsules prepared with coat to core ratio 2:1 were able to retard the release of drug for 12 hours. No significant change was observed in drug content and release pattern even after storage.
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Abstract
Terbutaline sulphate microcapsules were prepared by coacervation-phase separation induced by solvent evaporation technique. The cellulose acetate phthalate was employed as coating material alone and in combination with ethyl cellulose. The prepared microcapsules were evaluated for their drug content, particle size distribution (microscopic method), flow properties, bulk density and in vitro dissolution.
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