Self-transfecting GMO-PMO chimera targeting Nanog enable gene silencing in vitro and suppresses tumor growth in 4T1 allografts in mouse

Phosphorodiamidate morpholino oligonucleotide (PMO)-based antisense reagents cannot enter cells without the help of a delivery technique, which limits their clinical applications. To overcome this problem, self-transfecting guanidinium-linked morpholino (GMO)-PMO or PMO-GMO chimeras have been explored as antisense agents. GMO facilitates cellular internalization and participates in Watson-Crick base pairing. Targeting NANOG in MCF7 cells resulted in decline of the whole epithelial to mesenchymal transition (EMT) and stemness pathway, evident through its phenotypic manifestations, all of which were promulgated in combination with Taxol due to downregulation of MDR1 and ABCG2. GMO-PMO-mediated knockdown of no tail gene resulted in desired phenotypes in zebrafish even upon delivery after 16-cell stages. In BALB/c mice, 4T1 allografts were found to regress via intra-tumoral administration of NANOG GMO-PMO antisense oligonucleotides (ASOs), which was associated with occurrence of necrotic regions. GMO-PMO-mediated tumor regression restored histopathological damage in liver, kidney, and spleen caused by 4T1 mammary carcinoma. Serum parameters of systemic toxicity indicated that GMO-PMO chimeras are safe. To the best of our knowledge, self-transfecting antisense reagent is the first report since the discovery of guanidinium-linked DNA (DNG), which could be useful as a combination cancer therapy and, in principle, can render inhibition of any target gene without using any delivery vehicle.

Cananginone Abrogates EMT in Breast Cancer Cells through Hedgehog Signaling

Cananginones, a family of linear acetogenins found as secondary metabolites in the plant kingdom, show cytotoxicity against several types of cancer cells. We aimed to investigate the efficacy of cananginone and its mechanism as an anti-cancer agent. Our initial screening of Cananginone against HepG2, PC3, A549, and MCF7 cells showed anti-cancer activities and is more potent against MCF7 cells, consistent with the previous report. Next, cell-based assays have revealed that cananginone abrogates cancer stem cell renewal as well as Epithelial-Mesenchymal Transition (EMT) and increased the ROS level beyond the threshold level thus reducing the viability of cancer cells. In the connection of Hh-Gli to EMT, our study indicated that cananginone inhibits Gli1 in a non-canonical pathway. Presumably, this is the first report on the inhibitory activity of cananginone in the Hh pathway and is different from Hh-antagonists cyclopamine and GANT 61 considering the mechanism.

Internal Oligoguanidinium Transporter: Mercury-Free Scalable Synthesis, Improvement of Cellular Localization, Endosomal Escape, Mitochondrial Localization, and Conjugation with Antisense Morpholino for NANOG Inhibition to Induce Chemosensitization of Taxol in MCF-7 Cells

A nontoxic delivery vehicle is essential for the therapeutic applications of antisense phosphorodiamidate morpholino oligonucleotides (PMOs). Though guanidinium-rich or arginine-rich cellular transporter conjugated Vivo-PMO or PPMO has been developed for in vivo application, however, either their toxicity or stability has become an issue. Previously, we reported nonpeptidic internal guanidinium transporter (IGT) mediated delivery of PMO for gene silencing and got encouraging results. In this paper, we report the synthesis of IGT using a Hg-free method for scale up and N-terminal modification of IGT with a suitable hydrophobic or lipophilic group to improve the cell permeability, endosomal escape, and mitochondrial localization and to reduce toxicity in the MTT assay. For the delivery of PMO, IGT-PMO conjugate was synthesized to target NANOG in cells, a transcription factor required for cancer stem cell proliferation and embryonic development and is involved in many cancers. Our data shows IGT-PMO-facilitated NANOG inhibition, and thereby the prevention of EpCAM-N-Cadherin-Vimentin axis mediated epithelial to mesenchymal transition (EMT) in MCF-7 cells. Moreover, unlike taxol, NANOG inhibition influences the expression of stemness factor c-Myc, Hh-Gli signaling proteins, other cancer related factors, and their respective phenotypes in cancer cells. To the best of our knowledge, this is the first report to illustrate that the IGT-PMO-mediated NANOG inhibition increases the therapeutic potential of taxol and induces G0-G1 arrest in cancer cells to prevent cancer progression. However, it warrants further investigation in other cancer cells and preclinical platforms.

Impregnation of catheters with anacardic acid from cashew nut shell prevents Staphylococcus aureus biofilm development

AIM

The effect of anacardic acid impregnation on catheter surfaces for the prevention of Staphylococcus aureus attachments and biofilm formations were evaluated.

METHODS AND RESULTS

Silicon catheter tubes were impregnated using different concentrations of anacardic acids (0·002-0·25%). Anacardic acids are antibacterial phenolic lipids from cashew nut (Anacardium occidentale) shell oil. Anacardic acid-impregnated silicon catheters revealed no significant haemolytic activity and were cytocompatible against fibroblast cell line (L929). Sustained release of anacardic acids was observed for 4 days. Anacardic acid-impregnated silicon catheters efficiently inhibited S. aureus colonization and the biofilm formation on its surface. The in vivo antibiofilm activity of anacardic acid-impregnated catheters was tested in an intraperitoneal catheter-associated medaka fish infection model. Significant reduction in S. aureus colonization on anacardic acid-impregnated catheter tubes was observed.

CONCLUSIONS

Our data suggest that anacardic acid-impregnated silicon catheters may help in preventing catheter-related staphylococcal infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study opens new directions for designing antimicrobial phytochemical-coated surfaces with ideal antibiofilm properties and could be of great interest for biomedical research scientists.

Discovery of Hedgehog Antagonists for Cancer Therapy

BACKGROUND

The evolutionarily conserved Hedgehog (Hh) signaling cascade is one of the key mediators of embryonic development of many metazoans. This pathway has been extensively targeted by small molecule inhibitors as its misregulation leads to various malignancies and developmental disorders. Thus, blocking this pathway can be a novel therapeutic avenue for the treatment of Hedgehog-dependent cancers. This review covers the mechanism of hedgehog signaling in vertebrate cells, provides an overview of reported small molecule Hh pathway inhibitors, with the synthetic routes and SAR studies of some of them discussed briefly.

METHODS

A comprehensive survey of literature related to synthetic and naturally occurring Hh signaling antagonists reported till date is presented.

RESULTS

Given the selectivity of small molecules targeting, this pathway for cancer treatment compared to kinase, tubulin or HDAC inhibitors, several such antagonists have been discovered, of which some are in preclinical development and clinical studies. Most of the reported small molecules primarily antagonize the Smoothened receptor although agents targeting Gli1 transcription factor and Shh ligand have also been discovered. Till date, nine Smo antagonists have been evaluated in clinical trials.GDC- 0449/Vismodegib and NVP-LDE225/Erismodegib, were granted approval by the U.S. Food and Drug Administration (U.S. FDA) for the treatment of basal cell carcinoma.

CONCLUSION

The challenge is to identify agents that target the pathway downstream of Smo and develop strategies to overcome acquired drug resistance to the current Smo inhibitors with deeper understanding of the resistance mechanisms.

Progress in the development of gelling agents for improved culturability of microorganisms

Gelling agents are required for formulating both solid and semisolid media, vital for the isolation of microorganisms. Gelatin was the first gelling agent to be discovered but it soon paved the way for agar, which has far superior material qualities. Source depletion, issues with polymerase-chain-reaction and inability to sustain extermophiles etc., necessitate the need of other gelling agents. Many new gelling agents, such as xantham gum, gellan gum, carrageenan, isubgol, and guar gum have been formulated, raising the hopes for the growth of previously unculturable microorganisms. We evaluate the progress in the development of gelling agents, with the hope that our synthesis would help accelerate research in the field.

Chemosensory apparatus of Drosophila larvae

Many insects, including Drosophila melanogaster, have a rich repertoire of olfactory behavior. Combination of robust behavioral assays, physiological and molecular tools render D. melanogaster as highly suitable system for olfactory studies. The small number of neurons in the olfactory system of fruit flies, especially the number of sensory neurons in the larval stage, makes the exploration of sensory coding at all stages of its nervous system a potentially tractable goal, which is not possible in the foreseeable future in any mammalian preparation. Advances in physiological recordings, olfactory signaling and detailed analysis of behavior, can place larvae in a position to ask previously unanswerable questions.

Evolution of bacterial and fungal growth media

Microbial media has undergone several changes since its inception but some key challenges remain. In recent years, there has been exploration of several alternative nutrient sources, both to cater to the specificity in requirement of growth of “fussy microorganisms” and also to reduce costs for large-scale fermentation that is required for biotechnology. Our mini-review explores these developments and also points at lacunas in the present areas of exploration, such as a lack of concerted effort in pH and osmolarity regulation. We hope that our commentary provides direction for future research in microbial media.

Birth attendants as perinatal verbal autopsy respondents in low- and middle-income countries: a viable alternative?

OBJECTIVE

To assess the feasibility of using birth attendants instead of bereaved mothers as perinatal verbal autopsy respondents.

METHODS

Verbal autopsy interviews for early neonatal deaths and stillbirths were conducted separately among mothers (reference standard) and birth attendants in 38 communities in four developing countries. Concordance between maternal and attendant responses was calculated for all questions, for categories of questions and for individual questions. The sensitivity and specificity of individual questions with the birth attendant as respondent were assessed.

FINDINGS

For early neonatal deaths, concordance across all questions was 94%. Concordance was at least 95% for more than half the questions on maternal medical history, birth attendance and neonate characteristics. Concordance on any given question was never less than 80%. Sensitivity and specificity varied across individual questions, more than 80% of which had a sensitivity of at least 80% and a specificity of at least 90%. For stillbirths, concordance across all questions was 93%. Concordance was 95% or greater more than half the time for questions on birth attendance, site of delivery and stillborn characteristics. Sensitivity and specificity varied across individual questions. Over 60% of the questions had a sensitivity of at least 80% and over 80% of them had a specificity of at least 90%. Overall, the causes of death established through verbal autopsy were similar, regardless of respondent.

CONCLUSION

Birth attendants can substitute for bereaved mothers as verbal autopsy respondents. The questions in existing harmonized verbal autopsy questionnaires need further refinement, as their sensitivity and specificity differ widely.

An alternative strategy for perinatal verbal autopsy coding: single versus multiple coders

OBJECTIVE

To determine the comparability between cause of death (COD) by a single physician coder and a two-physician panel, using verbal autopsy.

METHODS

The study was conducted between May 2007 and June 2008. Within a week of a perinatal death in 38 rural remote communities in Guatemala, the Democratic Republic of Congo, Zambia and Pakistan, VA questionnaires were completed. Two independent physicians, unaware of the others decisions, assigned an underlying COD, in accordance with the causes listed in the chapter headings of the International classification diseases and related health problems, 10th revision (ICD-10). Cohen's kappa statistic was used to assess level of agreement between physician coders.

RESULTS

There were 9461 births during the study period; 252 deaths met study enrolment criteria and underwent verbal autopsy. Physicians assigned the same COD for 75% of stillbirths (SB) (K = 0.69; 95% confidence interval: 0.61-0.78) and 82% early neonatal deaths (END) (K = 0.75; 95% confidence interval: 0.65-0.84). The patterns and proportion of SBs and ENDs determined by the physician coders were very similar compared to causes individually assigned by each physician. Similarly, rank order of the top five causes of SB and END was identical for each physician.

CONCLUSION

This study raises important questions about the utility of a system of multiple coders that is currently widely accepted and speculates that a single physician coder may be an effective and economical alternative to VA programmes that use traditional two-physician panels to assign COD.

Using verbal autopsy to ascertain perinatal cause of death: are trained non-physicians adequate?

OBJECTIVES

To develop a standardized verbal autopsy (VA) training program and evaluate whether its implementation resulted in comparable knowledge required to classify perinatal cause of death (COD) by physicians and non-physicians.

METHODS

Training materials, case studies, and written and mock scenarios for this VA program were developed using conventional VA and ICD-10 guidelines. This program was used to instruct physicians and non-physicians in VA methodology using a train-the-trainer model. Written tests of cognitive and applied knowledge required to classify perinatal COD were administered before and after training to evaluate the effect of the VA training program.

RESULTS

Fifty-three physicians and non-physicians (nurse-midwives/nurses and Community Health Workers [CHW]) from Pakistan, Zambia, the Democratic Republic of Congo, and Guatemala were trained. Cognitive and applied knowledge mean scores among all trainees improved significantly (12.8 and 28.8% respectively, P < 0.001). Cognitive and applied knowledge post-training test scores of nurse-midwives/nurses were comparable to those of physicians. CHW (high-school graduates with 15 months or less formal health/nursing training) had the largest improvements in post-training applied knowledge with scores comparable to those of physicians and nurse-midwives/nurses. However, CHW cognitive knowledge post-training scores were significantly lower than those of physicians and nurses.

CONCLUSIONS

With appropriate training in VA, cognitive and applied knowledge required to determine perinatal COD is similar for physicians and nurses-midwives/nurses. This suggests that midwives and nurses may play a useful role in determining COD at the community level, which may be a practical way to improve the accuracy of COD data in rural, remote, geographic areas.

Spontaneous closure of the patent ductus arteriosus in very low birth weight infants following discharge from the neonatal unit

OBJECTIVE

To determine the incidence of spontaneous closure of the patent ductus arteriosus (PDA) and the use of medical therapies for treatment of PDA-related conditions among very low birth weight (VLBW) infants with ductal patency at the time of initial hospital discharge.

STUDY DESIGN

We conducted a single-centre, retrospective, observational study of VLBW infants (birth weight <1500 g) born during 2004 and 2005 and discharged with a PDA. PDA was defined by echocardiographic and/or clinical criteria. We identified the related discharge needs, subsequent interventions, and the post-menstrual age (PMA) at which there was no longer evidence of a PDA.

RESULTS

Three hundred and ninety one VLBW infants were admitted; 310 survived to discharge. Ninety five were diagnosed with a PDA during their hospitalisations; 21 had a PDA at discharge (10 received indomethacin, 11 were never treated). Among these, mean gestational age was 28 weeks, mean birth weight was 998 g, and median duration of hospitalisation was 73 days. Two infants were discharged on oxygen, two on diuretics, and two on both. None had congestive heart failure, and none died during infancy. Spontaneous closure occurred in 18 of 21 infants at a median PMA of 48 weeks (range 34-76; interquartile range 46-56). Two infants had coil occlusion at 11 months of age. One patient had a PDA at 14 months of age.

CONCLUSIONS

Among a select group of VLBW infants with a PDA at initial hospital discharge, spontaneous closure during early infancy occurred in most infants.

Effect of short term supplementation of tomatoes on antioxidant enzymes and lipid peroxidation in type-II diabetes

The objective of the present study is to evaluate the beneficial effect of tomatoes, which are rich source of Lycopene, relatively a new carotenoid known to play an important role in human health and disease. In this study lipid peroxidation rate was measured by estimating Malondialdehyde and the levels of serum enzymes involved in antioxidant activities like Super Oxide Dismutase, Glutathione Peroxidase, Glutathione Reductase, Reduced Glutathione, in type-II diabetic group (n=40) and age matched control group (n=50), and observed significantly lower levels of antioxidant enzymes and very high lipid peroxidation rate in type-II diabetes when compared to control group (p<0.001). Short term supplementation with tomatoes (cooked) to diabetic group for a period of 30 days, showed a significant improvement in antioxidant enzyme levels (p<0.001) and decreased lipid peroxidation rate (p<0.001) suggesting the supplementation with tomato lycopene may serve as the best method of preventing the oxidative stress in diabetic patients.

Treatment strategies to prevent or close a patent ductus arteriosus in preterm infants and outcomes

OBJECTIVE

To describe the current use of treatments to prevent or treat patent ductus arteriosus (PDA) in preterm infants, examine the association between different treatment strategies and neonatal outcomes and review the variation in these practices between centers.

STUDY DESIGN

Cohort study of infants born between 23 and 30 weeks gestation managed by the Pediatrix Medical Group from 1997 to 2004. We collected data on demographics, indomethacin and ligation, and outcomes of the following five groups: prophylactic indomethacin treatment: infants treated with indomethacin on day of life (DOL) 0 or 1; indicated indomethacin treatment: infants treated with indomethacin after DOL 1; PDA without treatment: infants with a PDA without report of treatment; ligation only: infants with a PDA ligation without use of indomethacin and no PDA: infants without a PDA and without treatment.

RESULTS

There were 6189 (18%) patients who received prophylactic indomethacin, 5690 (16%) patients received indicated treatment, 3886 (11%) patients had a PDA without treatment, 702 (2%) patients received ligation only and 18 136 (52%) patients had no PDA. In multivariate analysis, mortality among survivors to 2 days of age was lower (odds ratio (OR) 0.6, 95% confidence interval (CI) 0.5 to 0.7, P<0.01) and chronic lung disease, isolated intestinal perforation and severe retinopathy of prematurity (stages 3 and 4) were higher (OR 1.5, 95% CI 1.3 to 1.6, P<0.01; OR 1.5, 95% CI 1.1 to 2.0, P<0.01 and 1.4, 95% CI 1.2 to 1.6, P<0.01, respectively) in the indicated treatment group compared with the PDA without treatment group. The proportion of infants receiving prophylactic indomethacin among all infants and infants receiving indicated treatment among neonates with a report of a PDA varied by site from 0 to 59% (median 9.5%) and 0 to 100% (median 62%), respectively.

CONCLUSIONS

Indomethacin use for intraventricular hemorrhage prevention and/or treatment of a PDA is common, but the selection of infants for treatment, and the decision of when and how to treat vary widely between centers. Our findings suggest the need for randomized, placebo-controlled trials of the effect of treatment of the PDA in preterm infants.

Nicotine-induced proliferation of isolated rat pancreatic acinar cells: effect on cell signalling and function

OBJECTIVES

The aim of the current study was to investigate whether nicotine treatment would induce the proliferation of isolated rat primary pancreatic acinar cells in culture by activating mitogen-activated protein kinase (MAPK) signalling and exocrine secretion.

MATERIALS AND METHODS

A nicotine dose- and time-response curve was initially developed to determine the optimal dose and time used for all subsequent studies. Proliferation studies were conducted by cell counting and confirmed further by bromodeoxyuridine (BrdU) incorporation and flow cytometry assays. MAPK signalling studies were conducted by Western blot analysis. Localization of ERK1/2 signals, with or without nicotine and the MAPK inhibitor, was visualized by immunofluorescence.

RESULTS

Nicotine treatment caused dose-dependent activation of extracellular signal-regulated kinases (ERK1/2), the maxima occurring at 100 micro m and at 3 min after treatment; the response was suppressed by the ERK1/2 inhibitor. Maximal nicotine-induced cell proliferation occurred at 24 h, and UO126-treatment significantly reduced this response. Exposure of cells to 100 microm nicotine for 6 min significantly enhanced both baseline and cholecystokinin-stimulated cell function, and these effects were not affected by treatment with the inhibitor of ERK1/2 but were suppressed by mecamylamine, a nicotinic receptor antagonist.

CONCLUSIONS

Our results suggest that nicotine treatment induced cell proliferation of isolated pancreatic acinar cells and that this is coupled with the activation of MAPK signalling with no effect on its function. Hence, in primary cells, the mechanism of induction and regulation of these two processes, cell proliferation and cell function, by nicotine treatment are independent of each other.

A logit model for the effect of telecardiology on acute newborn transfers

The deregionalization of neonatal intensive care in the United States has shifted the site of care for many newborn infants away from academic medical centers where subspecialty support is available.

OBJECTIVE

To investigate the effect of immediate echocardiogram interpretation via telemedicine on rates of neonatal transfer to academic medical centers.

METHODS

A logit model was developed to predict the probability of transfer from two regional level 3 neonatal intensive care units to academic medical centers. One of these units implemented a telecardiology program and the other acted as a comparison institution with on-site cardiology expertise. The telecardiology intervention began 18 months into the 36-month study period.

SUBJECTS

Infants (n = 2,142) admitted to neonatal intensive care at either of the two institutions during calendar years 1994 through 1996.

RESULTS

A statistically significant reduction in the rate of transfer to academic medical centers was observed. Telecardiology was associated with a 58% reduction of such transfers (p = .001, 95% CI = 30%, 75%). No such reduction was noted at the comparison institution. It is estimated that approximately 30 transfers were eliminated during the study period, resulting in the elimination of approximately $150,000 in hospital charges. In addition, the infants that were transferred after the adoption of telemedicine were more often transferred to their telemedicine partner institution (p < .02).

Physiological regulation of the immunological synapse by agrin

T cell activation is dependent on both a primary signal delivered through the T cell receptor and a secondary costimulatory signal mediated by coreceptors. Although controversial, costimulation is thought to act through the specific redistribution and clustering of membrane and intracellular kinase-rich lipid raft microdomains at the contact site between T cells and antigen-presenting cells. This site has been termed the immunological synapse. Endogenous mediators of raft clustering in lymphocytes have not been identified, although they are essential for T cell activation. We now demonstrate that agrin, an aggregating protein crucial for formation of the neuromuscular junction, is also expressed in lymphocytes and is important in reorganization of membrane lipid microdomains and setting the threshold for T cell signaling. Our data show that agrin induces the aggregation of signaling proteins and the creation of signaling domains in both immune and nervous systems through a common lipid raft pathway.

Mediators of fetal inflammation in extremely low gestational age newborns

To establish levels of mediators of inflammation in cord blood and postnatal serum from extremely low gestational age newborns (ELGANs, < or =28 weeks), we measured sixteen markers of inflammation by recycling immunoaffinity chromatography in 15 ELGANs who had serum sampled at days 2-5. Median levels of IL-1, IL-6, IL-8, IL-11, IL-13, TNF-alpha, G-CSF, M-CSF, GM-CSF, MIP-1alpha, and RANTES were considerably higher than published values of these inflammatory mediators from term newborns. In three of eight ELGANS who had serial measurements taken, levels of IL-1, IL-6, IL-8, IL-11, TNF-alpha, G-CSF, and MIP-1alpha declined from initially very high levels to reach an apparent baseline towards the end of the first postnatal week. In these same three infants, GM-CSF and TGF-beta1 levels increased continuously during the first week. In the other five ELGANs, no consistent changes were observed. We speculate, that in some ELGANs, a fetal systemic inflammatory response is characterized by an antenatal wave of pro-inflammatory cytokines, followed by a second, postnatal wave of anti-inflammatory cytokines. Large epidemiologic studies are needed to clarify relationships among inflammation markers and their expression in the fetal and neonatal circulation over time. Such studies would also add to our understanding of the possible role of inflammatory mediators in the pathophysiology of the major complications of extreme prematurity.

Physiological effects of sound on the newborn

Excessive sound is an acknowledged problem in neonatal intensive care units (NICUs); however, there is relatively little objective information about the effects of sound on the newborn. The cardiovascular and respiratory systems have been the most extensively studied systems. The patterns of response in these systems may be influenced by a variety of factors, including: the intensity of the sound, the infant's behavioral state, the infant's maturity and postnatal age, and the perinatal history. This article reviews the known cardiovascular, respiratory, and other physiological effects of sound on neonates.

Serum inhibin, activin and follistatin in postmenopausal women with epithelial ovarian carcinoma

OBJECTIVE

To investigate the role of serum inhibin A, inhibin pro-alphaC immunoreactivity, activin A, and follistatin in postmenopausal women with epithelial ovarian cancer.

DESIGN

Case-control study.

SAMPLE

e Serum samples from 27 postmenopausal women with epithelial ovarian cancer and 54 controls from the general population participating in an ovarian cancer screening trial.

RESULTS

Women with epithelial ovarian cancer had significantly higher serum levels of pro-alphaC immunoreactivity (P = 0.03), activin A (P = 0.004) and follistatin (P = 0.04), but not inhibin A (P = 0.13). Using the 90th centile in the control group as the cut off, pro-alphaC levels were elevated in 41% of women with epithelial ovarian cancer, while inhibin A was elevated in only 15%. Using the 95th centile as the cut off, serum pro-alphaC was elevated in only 11% of women with epithelial ovarian cancer (3/27), while activin A was elevated in 48% (11/23). Follicle stimulating hormone levels were significantly lower in women with epithelial ovarian cancer (P = 0.01). Although, inhibin-related peptides can modulate follicle stimulating hormone levels, there was no correlation between inhibin A, pro-alphaC immunoreactivity, activin A or follistatin and follicle stimulating hormone.

CONCLUSION

These data demonstrate that though there is preferential secretion of precursor forms of the alpha subunit rather than dimeric inhibin A by epithelial ovarian cancer, pro-alphaC is unlikely to be a useful tumour marker. Activin A is more commonly elevated in postmenopausal women with epithelial ovarian cancer and its role as a tumour marker in the diagnosis and screening of epithelial ovarian cancer warrants further evaluation.

Continuous negative extrathoracic pressure in neonatal respiratory failure

OBJECTIVE

In uncontrolled clinical trials, negative extrathoracic pressure has been shown to be an effective respiratory support. We aimed to assess its role in the context of current neonatal intensive care.

DESIGN

A randomized controlled trial, with sequential analysis of matched pairs of infants. Matching was undertaken by stratified randomization from 15 groups divided according to gestational age, oxygen requirement, and whether patients were intubated at 4 hours of age.

SETTING

Two neonatal intensive care units.

PATIENTS

Two hundred forty-four patients (birth weight 1.53 +/- 0.69 kg (mean +/- SD); gestational age 30.4 +/- 3.5 weeks) with respiratory failure.

INTERVENTIONS

Patients were randomized at 4 hours of age to receive either standard neonatal intensive care, or standard care plus continuous negative extrathoracic pressure (CNEP, -4 to -6 cmH2O) applied within a purpose-designed neonatal incubator. OUTCOME SCORES: Clinical scores were calculated for each infant at 56 days of age, or death if earlier. Scores included measures for mortality, respiratory outcome, the presence of cerebral ultrasound abnormalities, patent arterial duct, necrotizing enterocolitis, and retinopathy. The treatment given for the higher score for each pair was recorded and the cumulative net number of pairs favoring CNEP plotted in the sequential analysis to provide an ethical early termination strategy. Individual components of the outcome score and other secondary measurements were analyzed on completion of the trial.

RESULTS

The sequential analysis reached a decision boundary after 122 out of a possible maximum of 124 pairs were completed. The overall outcome score showed an overall significant benefit for CNEP. Secondary analysis showed that the use of CNEP was associated with an increase in mortality, cranial ultrasound abnormalities, and pneumothoraces, which were not statistically significant. However, 5% fewer patients were intubated (95% confidence interval [CI], 0-10), and the total duration of oxygen therapy among surviving infants at 56 days was lower (20.5 days, compared with 38.9 in controls; difference 18.4 days, 95% CI 3.8 to 33.0). Among all infants, the mean total duration of oxygen therapy was 18.3 days among CNEP-treated infants compared with 33.6 days among the controls (difference -15.3 days, 95% CI -0.2 to -30.4). This reduction in mean levels is entirely attributable to substantially fewer patients requiring prolonged oxygen therapy, the median duration of treatment being very similar in the two groups. As a result, commensurately fewer surviving infants showed chronic lung disease of prematurity.

CONCLUSIONS

The use of continuous negative pressure improves the respiratory outcome for neonates with respiratory failure.

Carboline antifilarials: effects on carbohydrate metabolising enzymes in Litomosoides carinii female

Two antifilarial compounds, viz., 90/55 (7-oxo-1-phenyl-8, 14-dihydropyrido (3,4-b) imidazo (1,2-c) quinazolo (4,5-g) and 87/639 (6-Nitro-1-phenyl-9H-pyrido (3,4-b) indole at 0.5 and 2.0 micron concentrations substantially inhibited glucose uptake and increased lactate production by L. carinii during in vitro incubation for 2 hr. The treated parasites, showed increased activities of glycogen phosphorylase, phosphofructokinase and pyruvate kinase. Hexokinase and fumarate reductase activities level in the worms were significantly lowered. Therefore it appears that both the compounds kill adult L. carinii by interfering with its carbohydrate metabolism.

Trial of vitamin A supplementation in very low birth weight infants at risk for bronchopulmonary dysplasia

We performed a randomized, double-blind, controlled trial to determine whether vitamin A supplementation in a group of very low birth weight infants would reduce the incidence of bronchopulmonary dysplasia. Forty-nine infants (birth weight 700 to 1100 gm) requiring mechanical ventilation and supplemental oxygen at 96 hours age were randomly assigned to receive either 2000 IU retinyl palmitate (n = 27) or saline placebo (n = 22) intramuscularly every other day for up to 14 doses. There were no differences between treatment groups in the incidences of bronchopulmonary dysplasia at 31 days of postnatal age (vitamin A group 48%, placebo group 55%; p = 0.776), supplemental oxygen requirement at 34 weeks of postconceptional age, or other complications of prematurity. The vitamin A group had higher mean plasma vitamin A concentrations than the placebo group, but mean plasma vitamin A concentrations were greater than 20 micrograms/dl (suggesting sufficiency) in both groups after the first study week. By study day 28, only one fourth of the infants in either group had plasma vitamin A concentrations less than 20 micrograms/dl. In contrast to an earlier report, we found no change in the incidence of BPD with vitamin A supplementation. Our findings may reflect a low baseline incidence of vitamin A deficiency in the study population and recent changes in the respiratory care of very low birth weight infants. The latter may have lessened the potential impact of vitamin A deficiency on lung disease.

Involvement of beta 2-adrenoceptors in the regional haemodynamic responses to bradykinin in conscious rats

1. Bradykinin can release neuronal calcitonin gene-related peptide (CGRP) and adrenal medullary catecholamines, both of which could contribute to its cardiovascular effects in vivo. Therefore, in the main experiment, regional haemodynamic responses to bolus injections of bradykinin (3 nmol kg-1, i.v.) were assessed in the same chronically-instrumented, conscious, Long Evans rats in the absence and in the presence of human alpha-CGRP [8-37] or ICI 118551, antagonists of CGRP1-receptors and beta 2-adrenoceptors, respectively. The selected doses of these antagonists caused specific inhibition of responses mediated by exogenous human alpha-CGRP and beta 2-adrenoceptor agonists, respectively. 2. Bradykinin administered alone as an i.v. bolus had a slight pressor effect accompanied by a marked tachycardia. There were early (at about 30 s) increases in flow and conductance in the mesenteric vascular bed, and delayed (at about 90 s), but qualitatively similar, changes in the hindquarters vascular bed. There were only slight increases in flow and conductance in the renal vascular bed. 3. Human alpha-CGRP [8-37] had no statistically significant effects on the responses to bolus doses of bradykinin. However, in the presence of ICI 118551, the pressor effect of bradykinin was significantly enhanced while its tachycardic effect was significantly suppressed. The hindquarters vasodilator effect of bradykinin was converted to a vasoconstriction and there was a slight renal vasoconstriction, but the mesenteric vasodilator effect of bradykinin was unchanged by ICI 118551. 4. In subsidiary experiments, in other animals, it was found that infusion of bradykinin (36 nmol kg-1 min-1) elicited a pattern of haemodynamic responses similar to that seen with bolus injections and, as in the latter case, the hindquarters hyperaemic vasodilation was inhibited by ICI 118551. In the presence of mecamylamine (at a dose sufficient to block reflex heart rate responses to rises or falls in arterial blood pressure) bolus injection or infusion of bradykinin still elicited increases in renal, mesenteric and hindquarters blood flow. However, in additional experiments in adrenal demedullated rats (n = 4) the hindquarters hyperaemic effect of bradykinin was absent, although the mesenteric hyperaemic effect remained. 5. The results indicate that the increase in hindquarters blood flow following administration of bradykinin in vivo is largely due to activation of beta 2-adrenoceptors by catecholamines released subsequent to direct stimulation of the adrenal medulla by the peptide. However, the bradykinin-induced increase in mesenteric blood flow does not depend on this mechanism.

Results of laboratory surveillance of very low birth weight infants treated with a synthetic surfactant

During two randomized, controlled trials comparing single prophylactic doses of air placebo and a synthetic surfactant, Exosurf Neonatal, many routine laboratory measurements were made in small premature infants during the first week of life. Values for serum electrolytes, urea, creatinine, phospholipid, cholesterol, glucose, calcium, bilirubin, and liver enzymes, as well as for hemoglobin, leukocyte and platelet counts, and urinalysis, did not differ between the placebo- and surfactant-treated infants. There was no evidence that prophylactic administration of this synthetic surfactant causes alterations in standard laboratory tests in small premature infants.

Pharmacological characterization of a receptor for calcitonin gene-related peptide on rat, L6 myocytes

1 The L6 myocyte cell line expresses high affinity receptors for calcitonin gene-related peptide (CGRP) which are coupled to activation of adenylyl cyclase. The biochemical pharmacology of these receptors has been examined by radioligand binding or adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation. 2 In intact cells at 37 degrees C, human and rat alpha- and beta-CGRP all activated adenylyl cyclase with EC50s of about 1.5 nM. A number of CGRP analogues containing up to five amino acid substitutions showed similar potencies. In membrane binding studies at 22 degrees C in 1 mM Mg2+, the above all bound to a single site with IC50s of 0.1-0.4 nM. 3 The fragment CGRP(8-37) acted as a competitive antagonist of CGRP stimulation of adenylyl cyclase with a calculated Kd of 5 nM. The Kd determined in membrane binding assays was lower (0.5 nM). 4 The N-terminal extended human alpha-CGRP analogue Tyro-CGRP activated adenylyl cyclase and inhibited [125I]-iodohistidyl-CGRP binding less potently than human alpha-CGRP (EC50 for cyclase = 12 nM, IC50 for binding = 4 nM). 5 The pharmacological profile of the L6 CGRP receptor suggests that it most closely resembles sites on skeletal muscle, cardiac myocytes and hepatocytes. The L6 cell line should be a stable homogeneous model system in which to study CGRP mechanisms and pharmacology.

Structural studies on the [Bu(t)-Cys18](19-37)-fragment of human beta-calcitonin-gene-related peptide

High-field n.m.r. studies were undertaken upon a peptide fragment of the C-terminal region of human beta-calcitonin-gene-related peptide (beta-hCGRP). Studies on the antigenic [Bu(t)-Cys18]beta-hCGRP-(19-37)-fragment revealed that several elements of secondary structure were present when the peptide was dissolved in [2H6]dimethyl sulphoxide. In particular an unspecified turn in the region of Ser19-Gly20 and a type I beta-turn in the region of Asn31-Val32-Gly33 were identified. Through-space connections between the terminal Phe37 amide group and the beta-protons of Thr50 suggest that the peptide may be folded into a loop-type conformation. These structural elements appear to overlap with the epitopes of a number of monoclonal antibodies and provide a molecular basis for understanding the role of the terminal Phe37 amide residue in the immune recognition of beta-hCGRP.

Differential vasodilator profile of calcitonin gene-related peptide in porcine large and small diameter coronary artery rings

The vasodilator profile of calcitonin gene-related peptide (CGRP) was compared in large diameter (3-4 mm outer diameter) and small diameter (less than 1 mm outer diameter) rings from porcine left anterior descending coronary arteries (LAD). CGRP relaxed both sized rings in an endothelium-independent manner but was 10 X more potent in small compared to large diameter rings. Repeated administration of CGRP to small diameter rings did not cause the development of tolerance to its effects, whereas in the large diameter rings marked tolerance developed. Pretreatment with the CGRP peptide fragment, CGRP-(8-37) antagonised the vasodilator effects of CGRP in a concentration-dependent manner, but in large diameter rings, the antagonistic potency of CGRP-(8-37) was 10 X less than that seen in the small diameter rings. This differing vasodilator profile of CGRP in small and large diameter rings of pig LADs may be related to a differential CGRP receptor distribution along their length.

Antagonistic effect of human alpha-calcitonin gene-related peptide (8-37) on regional hemodynamic actions of rat islet amyloid polypeptide in conscious Long-Evans rats

Rat synthetic amidated islet amyloid polypeptide (IAPP) was infused into conscious Long-Evans rats chronically instrumented for the measurement of regional hemodynamics. Rat IAPP (0.25-2.5 nmol.kg-1.min-1) had dose-dependent tachycardiac and hypotensive effects. Renal blood flow increased at all dose levels in association with incremental rises in renal vascular conductances. Hindquarters blood flow and vascular conductance increased at the higher dose levels, but mesenteric blood flow fell with mean arterial blood pressure (i.e., there was no change in mesenteric vascular conductance). Concurrent infusion of 25 nmol.kg-1.min-1 human alpha-calcitonin gene-related peptide (CGRP) (8-37) abolished the hypotensive, tachycardiac, and renal and hindquarters vasodilator effects of rat IAPP, and during administration of both peptides, there was a transient renal and sustained mesenteric vasoconstriction. When the infusion of human alpha-CGRP (8-37) was stopped, the effects of the continued infusion of rat IAPP were reestablished. The results indicate that the reported ability of IAPP to induce insulin resistance cannot be due to decreased skeletal muscle blood flow. In addition, human alpha-CGRP (8-37) is an effective antagonist of the hemodynamic actions of rat IAPP. Because it has been shown previously that human alpha-CGRP (8-37) antagonizes the hemodynamic effects of human alpha-CGRP, these results, collectively, indicate that human alpha-CGRP and rat IAPP might act on the same receptor at which human alpha-CGRP (8-37) is an effective antagonist or that the latter is a nonselective antagonist of separate receptors on which human alpha-CGRP and rat IAPP act.

Human alpha-calcitonin gene-related peptide (CGRP)-(8-37), but not -(28-37), inhibits carotid vasodilator effects of human alpha-CGRP in vivo

Human alpha-calcitonin gene-related peptide-(8-37) alone (up to doses of 30 nmol kg-1 min-1) had no significant effects on blood pressure, heart rate or common or internal carotid haemodynamics, although it caused significant, reversible, inhibition of the hypotensive, tachycardic, and common and internal carotid vasodilator effects of human alpha-CGRP (0.03 nmol kg-1 min-1) in conscious, Long Evans rats. Human alpha-CGRP-(28-37) up to doses of 300 nmol kg-1 min-1 had no cardiovascular effects itself and did not influence responses to human alpha-CGRP. These results are consistent with the carotid haemodynamic effects of human alpha-CGRP being due largely to activation of the CGRP1-receptor subtype.

Solution structures of calcitonin-gene-related-peptide analogues of calcitonin-gene-related peptide and amylin

Near-u.v. and far-u.v. c.d. spectra of human alpha-calcitonin-gene-related peptide (h alpha CGRP), analogues and fragments of CGRP and amylin were recorded in aqueous solution and in trifluoroethanol (TFE)/water mixtures. All peptides contained significant amounts of alpha-helix in aqueous solution, and this amount increased on adding TFE. The helical content was unaffected by pH and salt. However, amylin contained much less helix than CGRP and the c.d. spectrum was more temperature-sensitive. A band in the near-u.v. c.d. spectrum of CGRP (but not present in the spectrum of amylin) was attributed to the disulphide bond in CGRP. The intensity of this band was pH-dependent and titrated with a pKa of 6.5, suggesting the involvement of histidine ionization.

Improved outcome at 28 days of age for very low birth weight infants treated with a single dose of a synthetic surfactant

Two identical double-blind, controlled, randomized trials were initiated to determine whether the administration of a single 5 ml/kg dose of a synthetic surfactant (Exosurf Neonatal), soon after the delivery of infants with birth weights 700 to 1350 gm, would improve rates of survival without bronchopulmonary dysplasia. Both trials were terminated before enrolling their planned sample sizes because of the availability of Exosurf under the provisions of a Treatment Investigational New Drug program. We report the combined results of these trials. Study infants were stratified according to birth weight and gender before random assignment to a treatment regimen. One hundred ninety-two infants received Exosurf and 193 received an air placebo. The study groups were similar when a variety of demographic features describing the mothers, their pregnancies, the circumstances of the births, and the infants were compared. Exosurf-treated infants required significantly less oxygen and respiratory support during the first 3 days of life in comparison with the air-treated infants. Fewer infants in the Exosurf group had pulmonary interstitial emphysema (26 vs 13; p = 0.028). In the Exosurf group, there was a significant reduction in the combined outcome, neonatal death or survival with bronchopulmonary dysplasia (57 vs 39; p = 0.042), and there was a significant increase in rates of survival without this disease (128 vs 137; p = 0.042). There were no differences between treatment groups in the incidences of a variety of complications of prematurity, including apnea, patent ductus arteriosus, intraventricular hemorrhage, and necrotizing enterocolitis. We conclude that improvements in respiratory physiology after a single prophylactic dose of Exosurf result in an increased likelihood of neonatal survival without bronchopulmonary dysplasia.

Monoclonal antibodies distinguishing alpha and beta forms of calcitonin gene-related peptide

A panel of 18 monoclonal antibodies was raised to the human calcitonin gene related peptide (CGRP). Of these mabs, seven were specific for alpha CGRP and five for beta CGRP, while the remainder reacted with both alpha and beta CGRP. Nine different epitopes on CGRP were defined with these mabs. In addition, the mabs were tested in various combinations to develop a series of two site assays specific for alpha or for beta CGRP as well as assays able to detect both.

Antagonistic effect of human alpha-CGRP [8-37] on the in vivo regional haemodynamic actions of human alpha-CGRP

In conscious rats, infusion of human alpha-CGRP [8-37] (30 nmol/kg/min) caused small, reversible reductions in hindquarters flow and vascular conductance only, whereas at a dose of 300 nmol/kg/min there was a tachycardia and an increase in mean arterial blood pressure, together with renal, mesenteric and hindquarters vasoconstrictions. Human alpha-CGRP (0.03 nmol/kg/min) caused tachycardia, hypotension, and transient renal, but sustained hindquarters, vasodilatation; these changes were accompanied by mesenteric vasoconstriction. Infusion of human alpha-CGRP [8-37] (30 nmol/kg/min) during administration of human alpha-CGRP (0.03 nmol/kg/min) abolished the effects of the latter but these re-appeared when the human alpha-CGRP [8-37] infusion was stopped. This dose of human alpha-CGRP [8-37] did not affect cardiovascular responses to isoprenaline. These results indicate that human alpha-CGRP [8-37] is an effective antagonist of the cardiovascular actions of human alpha-CGRP in vivo.

Pulmonary function following positive pressure ventilation initiated immediately after birth in infants with respiratory distress syndrome

Cardiopulmonary function following positive pressure ventilation, initiated immediately after birth, was evaluated in 10 very low birthweight infants with respiratory distress syndrome (RDS; RDS infants). Multiple gas rebreathing methodology was used to measure functional residual capacity (FRC), diffusing capacity of the lung for carbon monoxide (DLCO) and effective pulmonary capillary blood flow (Qeff) at 2, 24, and 72 hr of age. Cardiopulmonary function variables were also measured at 2 hr of age in 10 infants of similar birthweight who did not have RDS (non-RDS infants). In RDS infants, mean FRC at both 2 hr of age (15 mL/kg or 0.42 mL/cm) and 24 hours of age (20 mL/kg or 0.54 mL/cm) was less than published predicted values for healthy infants and significantly less than values in non-RDS infants at 2 hours of age (29 mL/kg or 0.8 mL/cm). By 72 hr of age, mean FRC in RDS infants rose to predicted. At 2 and 24 hours of age, mean Qeff in RDS infants (41 and 38 mL/min/kg, respectively) was below predicted, as well as below the value observed in non-RDS infants at 2 hr of age (62 mL/min/kg). in RDS infants. DLCO remained well below published predicted values throughout the first three days of life. We conclude that early aggressive respiratory therapy does not result in the establishment of normal lung volumes during the first day of life, but it does so by 3 days of age. However, in spite of intubation immediately after birth and the application of continuous positive pressure ventilation during the first 3 days of life, very low birthweight infants with RDS continue to have significant alteration in lung function, evidenced by impaired diffusing capacity of the lung and low arterial-alveolar oxygen tension ratios.

Survival and morbidity of extremely premature infants based on obstetric assessment of gestational age

To provide current clinical information for obstetric decision-making and perinatal management, we present early morbidity and mortality data for extremely premature infants based on obstetric assessment of gestational age. We reviewed the records of 141 live-born infants with birth weights of 1600 g or lower born at a university hospital level III neonatal intensive care unit between January 1986 and April 1988, whose gestational ages estimated by antenatal obstetric evaluation were between 24-29 completed weeks. Neonatal survival to 30 days ranged from 20% at 24 weeks to 94% at 29 weeks. Chronic lung disease was present at 30 days in all infants born at 24 weeks' gestation, decreasing to 13% of infants born at 29 weeks' gestation. Rates of severe intraventricular hemorrhage (grade 3 or 4) ranged from 100% at 24 weeks to 7% at 29 weeks. These data represent a significant increase in survival and a decrease in early morbidity compared with those form similar populations before 1986.

A study of knowledge, attitude and practice of leprosy among doctors of Bhopal, India

A study of knowledge, attitude and practice of leprosy among doctors of Bhopal has found that junior doctors had more exposure to leprology compared to all other groups. Medical college doctors had better knowledge of leprology compared to non-medical college doctors. Knowledge and attitude about leprosy among doctors were influenced by qualification, age, cultural and environmental factors. A strong association was observed between knowledge and attitude about leprosy of doctors and their practice of treating leprosy cases.