Exacerbations of asthma and chronic obstructive pulmonary disease (COPD): focus on virus induced exacerbations

Asthma and chronic obstructive pulmonary disease (COPD) are the 2 most prevalent chronic airway diseases. Much of the morbidity, mortality and health care costs of the diseases are associated with acute exacerbations, which are episodes of increased symptoms and airflow obstruction. Over the last decade evidence has emerged implicating virus respiratory tract infections as a major cause of exacerbations of both asthma and COPD. Current therapies are not very effective in the prevention or treatment of virus-induced exacerbations and exacerbations are therefore a major unmet medical need. The development of new and novel treatments requires a better understanding of the molecular and cellular mechanisms linking virus infection with exacerbations of asthma and COPD. This article provides an overview of current knowledge regarding the mechanisms of virus-induced exacerbations in both asthma and COPD. It will also review existing treatments and future treatments that are in advanced stages of development.

Maternal blood aspiration: an unusual cause of respiratory distress in a neonate

Maternal blood aspiration is an unusual cause of respiratory distress in neonates. It is occasionally seen in babies born to mothers with antepartum haemorrhage (APH). We report a term neonate with a history of maternal APH who developed respiratory distress soon after birth with a radiological appearance compatible with aspiration syndrome. The infant required ventilation for 36 hours. The aspirated blood was the mother's.

Silicon gel sheeting for preventing and treating hypertrophic and keloid scars

BACKGROUND

Keloid and hypertrophic scars are common and are caused by a proliferation of dermal tissue following skin injury. They cause functional and psychological problems for patients, and their management can be difficult. The use of silicon gel sheeting to prevent and treat hypertrophic scarring is still relatively new, and started in 1981 with treatment of burn scars.

OBJECTIVES

To determine the effectiveness of silicon gel sheeting for: (1) prevention of hypertrophic or keloid scarring in people with newly healed wounds (e.g. post surgery); (2) treatment of established scarring in people with existing keloid or hypertrophic scars.

SEARCH STRATEGY

Trials were identified from searches of the Cochrane Wounds Group Specialised Register (searched September 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2005); MEDLINE (1989 to June 2002); EMBASE (1988 to May 2002); CINAHL (1982 to May 2002) and reference lists of articles and relevant reviews. The major supplier of silicon gel sheeting (Smith and Nephew) was approached for details of unpublished, ongoing and recently published trials.

SELECTION CRITERIA

Any randomised or quasi-randomised controlled trials, or controlled clinical trials comparing silicon gel sheeting for prevention or treatment of hypertrophic or keloid scars against no treatment, placebo, or any other treatment type except surgery.

DATA COLLECTION AND ANALYSIS

All relevant trials were assessed for methodological quality. Data were extracted independently by both reviewers using a standardized form, and the results cross-checked. All trials, meeting the selection criteria were assessed for methodological quality.

MAIN RESULTS

Thirteen trials, involving 559 people, ranging in age from 2 to 81 years, were included in the review. The trials compared adhesive silicon gel sheeting with control; non-silicon gel sheeting; silicon gel plates with added Vitamin E; laser therapy; triamcinolone acetonide injection, and non-adhesive silicon gel sheeting. In the prevention studies, when compared with a no treatment option; whilst silicon gel sheeting reduced the incidence of hypertrophic scarring in people prone to scarring, (RR 0.46, 95% CI 0.21 to 0.98) these studies were highly susceptible to bias. Silicon gel sheeting produced a statistically significant improvement in scar elasticity, (RR 8.60, 95% CI 2.55 to 29.02), but again these studies were highly susceptible to bias.

AUTHORS' CONCLUSIONS

Trials evaluating silicon gel sheeting as a treatment for hypertrophic and keloid scarring are of poor quality and highly susceptible to bias. There is weak evidence of a benefit of silicon gel sheeting as a prevention for abnormal scarring in high risk individuals but the poor quality of research means a great deal of uncertainty prevails.

Gastric aspirate shake test for diagnosis of surfactant deficiency in neonates with respiratory distress

The gastric aspirate shake test (GST) was evaluated in 77 newborns with respiratory distress for predicting hyaline membrane disease (HMD) at KEM Hospital, Pune, India.

METHODS

Over 0.5 ml of gastric fluid was obtained within 30 min of birth and mixed with an equal volume of normal saline for 10 sec; 1 ml of 95% ethanol was then added and the mixture agitated for 10 sec. After standing for 15 min, the air-liquid interface was examined for bubbles.

RESULTS

All 21 infants with a negative GST developed HMD. However, 12 infants with an intermediate and nine with a positive test also developed HMD. None of the infants with other respiratory disorders, e.g. transient tachypnoea and pneumonia, had a negative GST. A negative GST had a specificity of 100%, sensitivity of 70% and positive predictive value of 100% for developing HMD.

CONCLUSION

GST is a useful test for predicting HMD and might be of particular value in developing countries.

High-resolution mapping, cloning and molecular characterization of the Pi-k ( h ) gene of rice, which confers resistance to Magnaporthe grisea

In order to understand the molecular mechanisms involved in the gene-for-gene type of pathogen resistance, high-resolution genetic and physical mapping of resistance loci is required to facilitate map-based cloning of resistance genes. Here, we report the molecular mapping and cloning of a dominant gene (Pi-k ( h )) present in the rice line Tetep, which is associated with resistance to rice blast disease caused by Magnaporthe grisea. This gene is effective against M. grisea populations prevalent in the Northwestern Himalayan region of India. Using 178 sequence tagged microsatellite, sequence-tagged site, expressed sequence tag and simple sequence repeat (SSR) markers to genotype a population of 208 F(2) individuals, we mapped the Pi-k ( h ) gene between two SSR markers (TRS26 and TRS33) which are 0.7 and 0.5 cM away, respectively, and can be used in marker-assisted-selection for blast-resistant rice cultivars. We used the markers to identify the homologous region in the genomic sequence of Oryza sativa cv. Nipponbare, and a physical map consisting of two overlapping bacterial artificial chromosome and P1 artificial chromosome clones was assembled, spanning a region of 143,537 bp on the long arm of chromosome 11. Using bioinformatic analyses, we then identified a candidate blast-resistance gene in the region, and cloned the homologous sequence from Tetep. The putative Pi-k ( h ) gene cloned from Tetep is 1.5 kbp long with a single ORF, and belongs to the nucleotide binding site-leucine rich repeat class of disease resistance genes. Structural and expression analysis of the Pi-k ( h ) gene revealed that its expression is pathogen inducible.

Salmonella osteomyelitis of the thoracic spine: an unusual presentation

A case of thoracic vertebral osteomyelitis due to Salmonella enteritidis phage type 2 in an immunocompetent patient is reported. The patient initially presented with abdominal, urinary and chest symptoms, which were followed by a large pleural effusion. The infection was successfully treated with ciprofloxacin. This is the only case of salmonella thoracic vertebral osteomyelitis in an immunocompetent patient reported in the English literature.

Living artificial heart valve alternatives: a review

Conventional replacement therapies for heart valve disease are associated with significant drawbacks. The field of tissue engineering has emerged as an exciting alternative in the search for improved heart valve replacement structures. One of the principles behind this concept is the transplantation of living elements, embedded in a suitable scaffold material, to the diseased site where the structure becomes integrated with patients' tissue to restore natural function. Significant progress has been made in the last ten years in the development of a living artificial heart valve alternative (LAHVA), with the identification of potential replacement sources for valve cells, scaffolds to maintain the cells in a three-dimensional environment, and signals to promote tissue development. This review addresses the need for a tissue-engineered alternative to current prostheses and provides a detailed account of normal heart valve structure--the blueprint for LAHVA fabrication. The research efforts to create a viable LAHVA, including recent developments, are discussed. Particular attention is focused on the choice of cell source for LAHVA construction, the use of biodegradable natural and synthetic polymeric scaffolds as extracellular matrix derivatives, and exogenous stimulation of tissue growth. The critical challenges involved in LAHVA development and possible future areas of investigation are also discussed.

Bioreactors for Cardiovascular Cell and Tissue Growth: A Review

Heart disease is a major cause of death in the Western world. In the past three decades there has been a number of improvements in artificial devices and surgical techniques for cardiovascular disease; however, there is still a need for novel devices, especially for those individuals who cannot receive conventional therapy. The major disadvantage of current artificial devices lies in the fact that they cannot grow, remodel, or repair in vivo. Tissue engineering offers the possibility of developing a biological substitute material in vitro with the inherent mechanical, chemical, biological, and morphological properties required in vivo, on an individual patient basis. In order to develop a true biological cardiovascular device a dynamic physiological environment needs to be created. One approach that employs the use of a simulated biological environment is a bioreactor in which the in vivo biomechanical and biochemical conditions are created in vitro for functional tissue development. A review of the current state of the art bioreactors for the generation of tissue engineered cardiovascular devices is presented in this study. The effect of the simulated physiological environment of the bioreactor on tissue development is examined with respect to the materials properties of vascular grafts, heart valves, and cardiac muscles developed in these bioreactors.

Investigations of intermediates appearing in the reassociation of the light-harvesting 1 complex of Rhodospirillum rubrum

We investigated the temperature-mediated reassociation of the B820 subunit of Rs. rubrum to form a light-harvesting 1 complex (LH 1). By combining several spectroscopic techniques with global spectral data analysis fitting, we present evidence for the occurence of two spectral intermediates that appear during the reassociation process. At high temperatures, halfway the reassociation reaction, a prominent intermediate appears that has an absorption maximum around 850 nm, a fluorescence maximum around 860-867 nm, a high anisotropy (0.3 to 0.4) and a circular dichroism spectrum with three or four bands with alternating signs. At lower temperatures, more towards the end of the reassociation process, a second intermediate tends to appear that has an absorption maximum around 860 nm, a fluorescence maximum around 885 nm, a medium to high anisotropy (0.1 to 0.3) and a circular dichroism spectrum with two bands with alternating signs. The latter circular dichroism spectrum has a blueshifted zero-crossing compared to the spectrum of the LH 1 complex. Both intermediates have the spectroscopic features of a small oligomer. In the Q(y) region, the fluorescence anisotropy of both intermediates slightly increases at longer excitation wavelengths, indicative for energy transfer among the pigments within the intermediate oligomers.

Time-resolved dissociation of the light-harvesting 1 complex of Rhodospirillum rubrum, studied by infrared laser temperature jump

For the first time, data are presented on the time-resolved disassembly reaction of a highly organized membrane protein complex in vitro. The photosynthetic core light-harvesting complex of the bacterial strain Rhodospirillum rubrum G9 consists of 12-16 dimeric subunits that in vivo are associated with the photosynthetic reaction center in a ringlike manner. Isolated in a detergent solution, its appearance either as a ringlike complex (called B873 and absorbing at 873 nm), subunit dimer (called B820 and absorbing at 820 nm), or monomeric form (called B777 and absorbing at 777 nm) is strongly temperature-dependent. In thermodynamic equilibria between B820 and B873, intermediate-sized complexes have also been observed that have absorption maxima around 850 nm. It is unknown whether these structures appear as intermediates in the kinetic B820-B873 (dis)assembly reaction. In this paper disassembly of the light-harvesting complex into its dimeric subunits was followed spectroscopically on a time scale up to 200 ms, upon applying an infrared laser-induced temperature jump. The full dissociation process appears to take place on a time scale of tens to hundreds of milliseconds, the rates becoming faster at higher starting temperatures. Applying the same technique, the dissociation reaction of dimeric subunits into monomers also could be established. This dissociation process occurred on a much faster time scale and took place within the 500 micros response time of our detection system.

Correlation of fine needle aspiration cytology, smear and culture in tuberculous lymphadenitis: a prospective study

BACKGROUND AND AIM

Bacteriological studies are necessary to confirm the diagnosis of tuberculous lymphadenitis, as cytological appearances mimic other granulomatous lesions. The objective was to assess the diagnostic role of culture of fine needle aspiration done on clinically suspected cases of tuberculous lymphadenitis and to determine the prevalence of drug resistance in M. tuberculosis isolates.

SETTING AND DESIGN

A prospective, double-blind study over a period of one year in a tertiary care hospital.

MATERIAL AND METHODS

Fine needle aspiration cytology and culture were done on 250 patients with clinical suspicion of tuberculous lymphadenitis.

STATISTICAL ANALYSIS

Data was statistically analysed using chi square test. Sensitivity, specificity, positive predictive and negative predictive values and likelihood ratio were also calculated.

RESULT

Of the 161 cytologically or microbiologically proven cases of tuberculous lymphadenitis, cytological changes consistent with tuberculosis were observed in 133 patients, out of which mycobacteria were isolated in 102 aspirates. Mycobacteria were also isolated from 28 aspirates cytologically missed as tuberculous lymphadenitis. Of the 130-mycobacterial isolates, 5 were non-tuberculous mycobacteria. Culture positivity was significantly higher (P<0.001) than smear positivity. Drug susceptibility studies showed resistance to one or more drugs in 61% of isolated strains with maximum resistance to isoniazid (16% primary and 48% secondary) and minimum to ethambutol (4% primary and 12% secondary).

CONCLUSION

Culture for mycobacteria should be carried out on all aspirates from patients suspected with tuberculous lymphadenitis.

Oligomerization of light-harvesting I antenna peptides of Rhodospirillum rubrum

We investigated the oligomerization of the core light-harvesting complex (LH1) of Rhodospirillum rubrum from the separated alpha beta BChl(2) subunits (B820) and the oligomerization of the B820 subunit from its monomeric peptides. The full LH1 complex was reversibly associated from B820 subunits by either varying the temperature in the range 277-300 K or by varying the detergent concentration in the buffer from 0.36 to 0.52% n-octyl-beta-D-glucopyranoside. Temperature-induced transition measurements showed hysteresis: raising the temperature induced dissociation of B873 directly into B820 subunits whereas upon recooling an intermediate spectral form was observed with an absorption maximum located around 850 nm. This intermediate form was also observed in detergent-induced transitions. It is speculated that the B850 form is a small aggregate of B820, for instance a dimer. Additionally, during a temperature-mediated transition at low detergent concentration, a set of spectral forms with maxima slightly blue-shifted from 873 nm were observed, possibly due to opened rings with one or only a few alpha beta BChl(2) units missing. The temperature-induced transition of LH1 is discussed in terms of a simple assembly model. It is concluded that a moderately cooperative assembly explains the formation of small aggregates of B820 as well as of incomplete rings. Furthermore, the B820 subunits were reversibly dissociated into the monomeric B777 form by increasing either the temperature or the detergent concentration. Estimations of the enthalpy and entropy changes for the dimeric association reaction of B777 into B820 yielded an enthalpy change of -216 kJ mol(-1) and an entropy change of -0.59 kJ mol(-1)K(-1), at a detergent concentration of 0.8% n-octyl-beta-D-glucopyranoside.

Folding and signaling share the same pathway in a photoreceptor

The photoreceptor photoactive yellow protein (PYP) was used as a model system to study receptor activation and protein folding. Refolding was studied by stopped-flow absorbance spectroscopy for PYP with either a trans or a cis chromophore. Chromophore trans to cis isomerization, the mechanism of light detection by PYP, greatly affects the protein folding process. When the cis chromophore is present, refolding from the unfolded state proceeds through the putative signaling state of PYP as an on-pathway intermediate. In addition, moderate denaturant concentrations result in the specific unfolding of the signaling state of PYP. Thus, the signaling state is common to the pathways of folding and signaling. This result provides an avenue for the study of protein folding. We demonstrate how this approach can be used to establish whether a folding intermediate is on-pathway or off-pathway. The results also reveal transient partial unfolding as a molecular mechanism for signaling.

Mullerian adenosarcoma of the uterine cervix

Sarcomas in the uterine cervix are rare, the incidence being 0.5% to 1% of all cervical malignancies. This is a report of cervical mullerian adenosarcoma, which was encountered in a hysterectomy performed for prolapse. The tumor was composed of benign glandular elements and malignant stromal component, thus justifying its nomenclature. We wish to emphasize the distinctive morphological features of this rare cervical tumor.

Induction of oxidative stress in antitubercular drug-induced hepatotoxicity

BACKGROUND AND AIM

Oxidative stress could play a role in the pathogenesis of antitubercular drug (ATD)-induced hepatotoxicity. We therefore studied the plasma level of reduced glutathione (GSH) and malondialdehyde (MDA) in patients with ATD-induced hepatotoxicity (cases), ATD-treated controls (disease controls) and in healthy volunteers.

METHODS

This study was carried out in a case-control design. Twenty-one cases, 21 age- and sex-matched disease controls, and 10 healthy volunteers were enrolled. Plasma levels of GSH and MDA were measured.

RESULTS

Plasma levels of GSH (median [range] 11.5 [6.2-21.2] mmol/dL) and MDA (1390 [560-2310] nmol/dL) of cases were significantly different (p<0.01) from GSH (18.4 [10.5-24.4]) and MDA (290 [240-550]) of disease controls. Further, plasma GSH and MDA levels of both the ATD-treated groups were different from those in healthy controls.

CONCLUSION

Lower levels of plasma GSH and higher levels of MDA may be due to oxidative stress resulting from ATD therapy.

Mortality and morbidity in high risk infants during a six year follow-up

OBJECTIVE

To study the mortality and morbidity in high risk infants after discharge from the hospital.

DESIGN

Prospective, 6 year follow up.

SETTING

High Risk Clinic (HRC).

METHODS

Infants discharged from a Neonatal Special Care Unit were identified for follow up using predetermined risk criteria. Home visits were made by the social worker, if appointments to HRC were missed. Verbal autopsy was performed in case of home deaths. Intercurrent illnesses and rehospitalizations were recorded. At six years, the children who had come for the final assessment at 30 months on the Bayley Scales, were recalled for assessment of the intelligence quotient, by Stanford-Binet Scale.

RESULTS

Four hundred and four high risk infants and eighty six controls were enrolled. There were 40 deaths in the study period, out of which 38 occurred in the first year of life, sixty per cent of these occurring in the first three months. The mortality was significantly higher in the VLBW group. Out of the 22 hospital deaths, 72.7% were due to infection. There was a significant difference (p < 0.001) in the mortality rate between the group which attended the HRC regularly (6.4%) as compared to that of the defaulters (27.6%). Ninety five children had rehospitalization in the High Risk group as compared to two in the control group (p < 0.001). In the 286 children who were assessed at 6 years, the incidence of borderline intelligence was 14.6% as compared to 5.6% in the controls (p < 0.05).

CONCLUSION

Mortality and rehospitalization rate is high in high risk infants, after discharge from the hospital. Children who appear to have normal development in the third year, may show a high incidence (14.6%) of borderline intelligence at six years.

Senescent: a new Neurospora crassa nuclear gene mutant derived from nature exhibits mitochondrial abnormalities and a "death" phenotype

Fungi are capable of potentially unlimited growth. We resolved nuclear types from multinuclear mycelium of a phenotypically normal wild isolate of the fungus Neurospora intermedia by plating its uninucleate microconidia and obtained a strain which, unlike the "parent" strain, exhibited clonal senescence in subcultures. The mutant gene, senescent, was introgressed into N. crassa and mapped four map units to the right of the his-1 locus on linkage group VR. senescent is the first nuclear gene mutant of Neurospora derived from nature that shows the death phenotype. Death of the sen mutant occurred faster at 34 degrees C than at 22 or 26 degrees C. Measurements of oxygen uptake of conidia using respiratory inhibitors and the spectrophotometric analyses of mitochondrial cytochromes showed that in sen cultures grown at 34 degrees C, cytochromes b and aa(3) were present but cytochrome c was absent. By contrast at 26 degrees C, cytochromes b and c were present but cytochrome aa(3) was diminished in the late subcultures. This suggested that the sen mutation does not affect the potential to produce functional cytochromes. The deficiency of the respiratory chain cytochromes may not be the cause of death of the sen mutant because the cytochrome c and aa(3) mutants of N. crassa are capable of sustained growth whereas sen is not. Possible explanations for the observations are discussed.

Essential role for both CD80 and CD86 costimulation, but not CD40 interactions, in allergen-induced Th2 cytokine production from asthmatic bronchial tissue: role for alphabeta, but not gammadelta, T cells

CD80 and CD86 interact with CD28 and deliver costimulatory signals required for T cell activation. We demonstrate that ex vivo allergen stimulation of bronchial biopsy tissue from mild atopic asthmatic, but not atopic nonasthmatic, subjects induced production of IL-5, IL-4, and IL-13. Explants from both study groups did not produce IFN-gamma, but secreted the chemokine RANTES without any overt stimulation. In addition to allergen, stimulation of asthmatic explants with mAbs to CD3 and TCR-alphabeta but not TCR-gammadelta induced IL-5 secretion. Allergen-induced IL-5 and IL-13 production by the asthmatic tissue was inhibited by anti-CD80 and, to a lesser extent, by anti-CD86 mAbs. In contrast, the production of these cytokines by PBMCs was not affected by mAbs to CD80, was inhibited by anti-CD86, and was strongly attenuated in the presence of both Abs. FACS analysis revealed that stimulated asthmatic bronchial tissue was comprised of CD4+ T cells that expressed surface CD28 (75. 3%) but little CTLA-4 (4.0%). Neutralizing mAbs to CD40 ligand had no effect on the cytokine levels produced by asthmatic tissue or PBMCs. Collectively, these findings suggest that allergen-specific alphabeta T cells are resident in asthmatic bronchial tissue and demonstrate that costimulation by both CD80 and CD86 is essential for allergen-induced cytokine production. In contrast, CD86 appears to be the principal costimulatory molecule required in PBMC responses. Attenuation of type 2 alphabeta T cell responses in the bronchial mucosa by blocking these costimulatory molecules may be of therapeutic potential in asthma.

How do Jains get toxoplasma infection?

Toxoplasma infection is as prevalent among Jains as among other religious groups in the same area. Jain laws mean that exposure to Toxoplasma gondii via well known routes of infection is unlikely; drinking water may be the vehicle of infection.

Pancreatic lymphoma masquerading as adenocarcinoma

Primary pancreatic lymphoma is rare. We report a young man with primary lymphoma in the pancreatic head who presented with obstructive jaundice.