Balance of growth factors in the human perinatal lung : Implications for physiological lung development and link to bronchopulmonary dysplasia

The aims of this Thesis was to evaluate the role of proangiogenic placental growth factor (PlGF), antiangiogenic endostatin and lymphangiogenic vascular endothelial growth factor (VEGF) -C as well as the receptors vascular endothelial growth factor receptor (VEGFR) -2 and VEGFR-3 during lung development and in development of lung injury in preterm infants. The studied growth factors were selected due to a close relationship with VEGF-A; a proangiogenic growth factor important in normal lung angiogenesis and lung injury in preterm infants. The thesis study consists of three analyses. I: Lung samples from fetuses, preterm and term infants without lung injury, as well as preterm infants with acute and chronic lung injury were stained by immunohistochemistry for PlGF, endostatin, VEGF-C, VEGFR-2 and VEGFR-3. II: Tracheal aspirate fluid (TAF) was collected in the early postnatal period from a patient population consisting of 59 preterm infants, half developing bronchopulmonary dysplasia (BPD) and half without BPD. PlGF, endostatin and VEGF-C concentrations were measured by commercial enzyme-linked immunosorbent assay (ELISA). III: Cord plasma was collected from very low birth weight (VLBW) (n=92) and term (n=48) infants in conjuncture with birth and endostatin concentrations were measured by ELISA. I: All growth factors and receptors studied were consistently stained in immunohistochemistry throughout development. For endostatin in early respiratory distress syndrome (RDS), no alveolar epithelial or macrophage staining was seen, whereas in late RDS and BPD groups, both alveolar epithelium and macrophages stained positively in approximately half of the samples. VEGFR-2 staining was fairly consistent, except for the fact that capillary endothelial staining in the BPD group was significantly decreased. II: During the first postnatal week in TAF mean PlGF concentrations were stable whereas mean endostatin and VEGF-C concentrations decreased. Higher concentrations of endostatin and VEGF-C correlated with lower birth weight (BW) and associated with administration of antenatal betamethasone. Parameters reflecting prenatal lung inflammation associated with lower PlGF, endostatin and VEGF-C concentrations. A higher mean supplemental fraction of inspired oxygen during the first 2 postnatal weeks (FiO2) correlated with higher endostatin concentrations. III: Endostatin concentrations in term infants were significantly higher than in VLBW infants. In VLBW infants higher endostatin concentrations associated with the development of BPD, this association remained significant after logistic regression analysis. We conclude that PlGF, endostatin and VEGF-C all have a physiological role in the developing lung. Also, the VEGFR-2 expression profile seems to reflect the ongoing differentiation of endothelia during development. Both endostatin and VEGFR-2 seem to be important in the development of BPD. During the latter part of the first postnatal week, preterm infants developing BPD have lower concentrations of VEGF-A in TAF. Our findings of disrupted VEGFR-2 staining in capillary and septal endothelium seen in the BPD group, as well as the increase in endostatin concentrations both in TAF and cord plasma associated with BPD, seem to strengthen the notion that there is a shift in the angiogenic balance towards a more antiangiogenic environment in BPD. These findings support the vascular hypothesis of BPD.

Differential Mechanisms of Binding of Anti-Sigma Factors Escherichia coli Rsd and Bacteriophage T4 AsiA to E. coli RNA Polymerase Lead to Diverse Physiological Consequences

Anti-sigma factors Escherichia coli Rsd and bacteriophage T4 AsiA bind to the essential housekeeping sigma factor, sigma(70), of E. coli. Though both factors are known to interact with the C-terminal region of sigma(70), the physiological consequences of these interactions are very different. This study was undertaken for the purpose of deciphering the mechanisms by which E. coli Rsd and bacteriophage T4 AsiA inhibit or modulate the activity of E. coli RNA polymerase, which leads to the inhibition of E. coli cell growth to different amounts. It was found that AsiA is the more potent inhibitor of in vivo transcription and thus causes higher inhibition of E. coli cell growth. Measurements of affinity constants by surface plasmon resonance experiments showed that Rsd and AsiA bind to or 70 with similar affinity. Data obtained from in vivo and in vitro binding experiments clearly demonstrated that the major difference between AsiA and Rsd is the ability of AsiA to form a stable ternary complex with RNA polymerase. The binding patterns of AsiA and Rsd with sigma(70) studied by using the yeast two-hybrid system revealed that region 4 of sigma(70) is involved in binding to both of these anti-sigma factors; however, Rsd interacts with other regions of sigma(70) as well. Taken together, these results suggest that the higher inhibition of E. coli growth by AsiA expression is probably due to the ability of the AsiA protein to trap the holoenzyme RNA polymerase rather than its higher binding affinity to sigma(70).

Japanese encephalitis: pathogenesis, prophylactics and therapeutics

Japanese encephalitis (JE) is one of the most dreaded mosquito-borne viral encephalitis known to afflict humans. The Japanese encephalitis virus (JEV) is a neurotropic flavivirus that affects the CNS, causing extensive damage that may lead to fatality in about one third of bpatients. Half of the survivors suffer from severe neuropshychiatric sequelae. With nearly 3 billion people living under the current JE-endemic region, recurring incidents of epidemic are being reported at regular intervals. With no established antiviral therapies against JE available, vaccination has been the only way of preventing JE. Two types of JE vaccines are currently in vogue although the safety of administering them is questionable, in certain individuals. Thus, there is a need to develop a safe, affordable and potent JE vaccine and this review addresses the current efforts in this direction. This review also focuses on the pathophysiology of JE and efforts towards a possible breakthrough in anti-JEV therapy.

Management of persistent pain in the older people

Persistent pain is a commonly experienced symptom. It affects 25% of community-dwelling older adults and up to 80% of nursing home residents, and can have a major impact on quality of life and functional capacity. Unfortunately pain in older patients is often undertreated and misunderstood. Assessment of pain type and severity is important. Most older people, even with moderately impaired cognition, are able to self-report pain. Validated assessment tools using non-verbal pain cues are available for people with more advanced cognitive impairment. Management of pain in older people can be challenging. Physiological changes may impact on pain perception and the pharmacodynamics and pharmacokinetics of medications. Older people are often more sensitive to the adverse effects of analgesic medications and are at risk of drug–drug interactions due to the presence of co-morbidities and polypharmacy. In general, analgesic medications should be commenced at low doses, titrated based on effect and tolerability, and regularly reviewed. Contemporary pain management often utilises multiple analgesics in lower doses to optimise efficacy and avoid dose-related toxicity. A bio-psycho-social approach to the management of persistent pain, utilising a multidisciplinary team and including non-drug strategies, may produce the best results. The goal of pain management is not always to eliminate pain, since this may not be attainable, but rather to enhance function and improve quality of life. This article discusses persistent non-cancer pain in older people, its assessment and management, and the risks and benefits of pharmacological treatment in this population.

Developmental origins of physiological stress reactivity

The model of developmental origins of health and disease proposes that organisms during fetal period utilize cues that enable their adaptation in the postnatal environment they are likely to live, having short-term advantages when trying to survive in environment but simultaneously in the long run have costs for health. A large body of epidemiological research has found that low birth weight, a marker of intrauterine conditions, is associated with cardiovascular (CV) disease. Since the reported associations of birth weight with normal variation in the resting blood pressure (BP), a major predictor of CV disease risk, have been modest, a key candidate mediating the link has been CV and hypothalamus-pituitary-adrenal axes (HPAA) reactivity to stress. In addition, not only weight at birth but also gestational age and early postnatal growth may have independent associations to stress reactivity. The aim of this thesis was to investigate whether pre- and postnatal growth and gestational age are associated with CV and HPAA activity before, during and after stress in childhood and in late adulthood. Altogether 287 men and women aged 60-70 and 299 boys and girls aged 7-9 underwent Trier Social Stress Test. Several indices of HPAA and CV were measured and birth size and gestational age were obtained from birth records. Results showed that low birth weight was associated with low HPAA activity during psychosocial stress, and rapid gain in BMI during years 7-11 was related to heightened stress reactivity to psychosocial stress. Size at birth in children and gestational age and early postnatal (0-2 years) gain in height in adults were associated with CV stress responses; however, in a sex-specific manner. Given that CV stress responses and HPAA activity are markers of CV disease vulnerability, our results may partly explain the associations between early environment and later CV disease.

Importance of carbon dioxide physiological forcing to future climate change

An increase in atmospheric carbon dioxide (CO2) concentration influences climate both directly through its radiative effect (i.e., trapping longwave radiation) and indirectly through its physiological effect (i.e., reducing transpiration of land plants). Here we compare the climate response to radiative and physiological effects of increased CO2 using the National Center for Atmospheric Research (NCAR) coupled Community Land and Community Atmosphere Model. In response to a doubling of CO2, the radiative effect of CO2 causes mean surface air temperature over land to increase by 2.86 ± 0.02 K (± 1 standard error), whereas the physiological effects of CO2 on land plants alone causes air temperature over land to increase by 0.42 ± 0.02 K. Combined, these two effects cause a land surface warming of 3.33 ± 0.03 K. The radiative effect of doubling CO2 increases global runoff by 5.2 ± 0.6%, primarily by increasing precipitation over the continents. The physiological effect increases runoff by 8.4 ± 0.6%, primarily by diminishing evapotranspiration from the continents. Combined, these two effects cause a 14.9 ± 0.7% increase in runoff. Relative humidity remains roughly constant in response to CO2-radiative forcing, whereas relative humidity over land decreases in response to CO2-physiological forcing as a result of reduced plant transpiration. Our study points to an emerging consensus that the physiological effects of increasing atmospheric CO2 on land plants will increase global warming beyond that caused by the radiative effects of CO2.

Emerging trends at the interface of chemistry and biology: Applications to the design of human therapeutics

This article describes recent developments in the design and implementation of various strategies towards the development of novel therapeutics using first principles from biology and chemistry. Strategies for multi-target therapeutics and network analysis with a focus on cancer and HIV are discussed. Methods for gene and siRNA delivery are presented along with challenges and opportunities for siRNA therapeutics. Advances in protein design methodology and screening are described, with a focus on their application to the design of antibody based therapeutics. Future advances in this area relevant to vaccine design are also mentioned.

T-type calcium channel:from physiological function to therapeutical targeting – Exploring neuronal development

Tämän tutkimuksen tarkoitus oli tutkia T-tyypin kalsiumkanavan toimintaa ja sen mahdollista roolia neuronaalisten kantasolujen migraatiossa. T-tyypin kalsiumkanavan tehtävän kehittyneissä aivoissa tiedetään olevan elektroenkefalografisten oskillaatioiden tuottaminen. Nämä taas ovat eräiden fysiologisten ja patofysiologisten tapahtumien säätelyssä avainasemassa. Tällaisia tapahtumia ovat uni, muisti, oppiminen ja epileptiset poissaolokohtaukset. Näiden lisäksi T-tyypin kalsiumkanavalla on myös periferaalisia vaikutuksia, mutta tämä tutkielma keskittyy sen neuronaalisiin toimintoihin. Tämän matalan jännitteen säätelemän kanavan toiminta neurogeneesin aikana on vähemmän tutkittua ja tunnettua kuin sen vaikutukset kehittyneissä aivoissa. T-tyypin kalsiumkanavan tiedetään edistävän kantasolujen proliferaatiota ja erilaistumista neurogeneesiksen aikana, mutta vaikutukset niiden migraatioon ovat vähemmän tunnetut. Tämä tutkimus näyttää T-tyypin kalsiumkanavan todennäköisesti osallistuvan neuronaaliseen migraatioon hiiren alkion subventrikkeli alueelta eristetyillä kanta- tai progeniittorisoluilla tehdyissä kokeissa. Selektiiviset T-tyypin kalsiumkanavan antagonistit, etosuksimidi, nikkeli ja skorpionitoksiini, kurtoxin hidastivat migraatiota erilaistuvissa progeniittorisoluissa. Tämä tutkimus koostuu kirjallisuuskatsauksesta ja kokeellisesta osasta. Tämän tutkimuksen toinen tarkoitus oli esitellä vaihtoehtoinen lähestymistapa invasiiviselle kantasoluterapialle, joka vaatii kantasolujen viljelyä ja siirtämistä ihmiseen. Tämä toinen tapa on endogeenisten kantasolujen eiinvasiivinen stimulointi, jolla ne saadaan migratoitumaan kohdekudokseen, erilaistumaan siellä ja tehtävänsä suoritettuaan lopettamaan jakaantumisen. Non-invasiivinen kantasoluterapia on vasta tiensä alussa, ja tarvitsee farmakologista osaamista kehittyäkseen. Joitain onnistuneita ei-invasiivisia hoitoja on jo tehty selkärangan vaurioiden korjaamisessa. Vastaavanlaisia menetelmiä voitaisiin käyttää myös keskushermoston vaurioiden ja neurodegeneratiivisten sairauksien hoidossa. Näiden menetelmien kehittäminen vaatii endogeenisten kantasoluja inhiboivien ja indusoivien mekanismien tuntemista. Yksi tärkeä kantasolujen erilaistumista stimuloiva tekijä on kalsiumioni. Jänniteherkät kalsiumkanavat osallistuvat kaikkiin neurogeneesiksen eri vaiheisiin. T-tyypin kalsiumkanava, joka ekspressoituu suuressa määrin keskushermoston kehityksen alkuvaiheessa ja vähenee neuronaalisen kehityksen edetessä, saattaa olla oleellisessa asemassa progeniittorisolujen ohjaamisessa.

Chaperone expression profiles correlate with distinct physiological states of Plasmodium falciparum in malaria patients

Background: Molecular chaperones have been shown to be important in the growth of the malaria parasite Plasmodium falciparum and inhibition of chaperone function by pharmacological agents has been shown to abrogate parasite growth. A recent study has demonstrated that clinical isolates of the parasite have distinct physiological states, one of which resembles environmental stress response showing up-regulation of specific molecular chaperones. Methods: Chaperone networks operational in the distinct physiological clusters in clinical malaria parasites were constructed using cytoscape by utilizing their clinical expression profiles. Results: Molecular chaperones show distinct profiles in the previously defined physiologically distinct states. Further, expression profiles of the chaperones from different cellular compartments correlate with specific patient clusters. While cluster 1 parasites, representing a starvation response, show up-regulation of organellar chaperones, cluster 2 parasites, which resemble active growth based on glycolysis, show up-regulation of cytoplasmic chaperones. Interestingly, cytoplasmic Hsp90 and its co-chaperones, previously implicated as drug targets in malaria, cluster in the same group. Detailed analysis of chaperone expression in the patient cluster 2 reveals up-regulation of the entire Hsp90-dependent pro-survival circuitries. In addition, cluster 2 also shows up-regulation of Plasmodium export element (PEXEL)-containing Hsp40s thought to have regulatory and host remodeling roles in the infected erythrocyte. Conclusion: In all, this study demonstrates an intimate involvement of parasite-encoded chaperones, PfHsp90 in particular, in defining pathogenesis of malaria.

Efficient syntheses of benzothiazepines as antagonists for the mitochondrial sodium-calcium exchanger: Potential therapeutics for type II diabetes

Type II diabetes mellitus is a chronic metabolic disorder that can lead to serious cardiovascular, renal, neurologic, and retinal complications. While several drugs are currently prescribed to treat type II diabetes, their efficacy is limited by mechanism-related side effects (weight gain, hypoglycemia, gastrointestinal distress), inadequate efficacy for use as monotherapy, and the development of tolerance to the agents. Consequently, combination therapies are frequently employed to effectively regulate blood glucose levels. We have focused on the mitochondrial sodium-calcium exchanger (mNCE) as a novel target for diabetes drug discovery. We have proposed that inhibition of the mNCE can be used to regulate calcium flux across the mitochondrial membrane, thereby enhancing mitochondrial oxidative metabolism, which in turn enhances glucose-stimulated insulin secretion (GSIS) in the pancreatic beta-cell. In this paper, we report the facile synthesis of benzothiazepines and derivatives by S-alkylation using 2-aminobenzhydrols. The syntheses of other bicyclic analogues based on benzothiazepine, benzothiazecine, benzodiazecine, and benzodiazepine templates are also described. These compounds have been evaluated for their inhibition of mNCE activity, and the results from the structure-activity relationship (SAR) studies are discussed.

Utilizing Model Nanostructured Porous Inorganic Compounds Such as Silica to Beneficially Confine “Bio”-Relevant Molecules and Demonstrate their Potential in Therapeutics

Abstract | The importance of well-defined inorganic porous nanostructured materials in the context of biotechnological applications such as drug delivery and biomolecular sensing is reviewed here in detail. Under optimized conditions, the confinement of “bio”-relevant molecules such as pharmaceutical drugs, enzymes or proteins inside such inorganic nanostructures may be remarkably beneficial leading to enhanced molecular stability, activity and performance. From the point of view of basic research, molecular confinement inside nanostructures poses several formidable and intriguing problems of statistical mechanics at the mesoscopic scale. The theoretical comprehension of such non-trivial issues will not only aid in the interpretation of observed phenomena but also help in designing better inorganic nanostructured materials for biotechnological applications.

Sensitivity of terrestrial water and energy budgets to CO(2)-physiological forcing: an investigation using an offline land model

Increasing concentrations of atmospheric carbon dioxide (CO(2)) influence climate by suppressing canopy transpiration in addition to its well- known greenhouse gas effect. The decrease in plant transpiration is due to changes in plant physiology (reduced opening of plant stomata). Here, we quantify such changes in water flux for various levels of CO(2) concentrations using the National Center for Atmospheric Research's (NCAR) Community Land Model. We find that photosynthesis saturates after 800 ppmv (parts per million, by volume) in this model. However, unlike photosynthesis, canopy transpiration continues to decline at about 5.1% per 100 ppmv increase in CO(2) levels. We also find that the associated reduction in latent heat flux is primarily compensated by increased sensible heat flux. The continued decline in canopy transpiration and subsequent increase in sensible heat flux at elevated CO(2) levels implies that incremental warming associated with the physiological effect of CO(2) will not abate at higher CO(2) concentrations, indicating important consequences for the global water and carbon cycles from anthropogenic CO(2) emissions.