Effect of sputum bacteriology on the quality of life of patients with bronchiectasis

Bronchiectatic patients have impaired health-related quality of life (QoL) and are prone to chronic lower respiratory tract infections. We have investigated whether impaired QoL is related to sputum bacteriology. Eighty seven patients with non-cystic fibrosis (non-CF) bronchiectasis, in a stable phase of their illness, completed three QoL measures, underwent a computed tomography (CT) scan and lung function tests, and provided a fresh sputum sample for microscopy and culture. The QoL of patients colonized by Pseudomonas aeruginosa (Pa group) was significantly worse than all other patients grouped together (non-Pa group), and specifically those infected by Haemophilus influenzae (Hi group) or who had no bacterial growth (NG group) (p<0.05), but not those infected by other bacterial species (O group). The Pa group had worse lung function, but no significant differences were found between the groups for forced expiratory volume in one second (FEV1) and peak expiratory flow rate. The Pa group had significantly worse bronchiectasis scores than the O, NG and non-Pa groups, but not the Hi group. There were no significant differences between the groups with respect to the number of infective exacerbations in the last year, but the Pa group had significantly more hospital admissions. Patients infected by P. aeruginosa for more than 3 yrs had significantly worse FEV1 (p<0.03) and bronchiectasis scores (p<0.05) than those infected with P. aeruginosa for less time, but not significantly worse QoL. We conclude that, overall, patients infected with P. aeruginosa have worse quality of life, and that P. aeruginosa is associated with a greater extent of disease and worse lung function. Although patients infected with H. influenzae had extensive bronchiectasis their quality of life was better than the P. aeruginosa infected group.

Control of cell fates and segmentation in the Drosophila mesoderm

The primordia for heart, fat body, and visceral and somatic muscles arise in specific areas of each segment in the Drosophila mesoderm. We show that the primordium of the somatic muscles, which expresses high levels of twist, a crucial factor of somatic muscle determination, is lost in sloppy-paired mutants. Simultaneously, the primordium of the visceral muscles is expanded. The visceral muscle and fat body primordia require even-skipped for their development and the mesoderm is thought to be unsegmented in even-skipped mutants. However, we find that even-skipped mutants retain the segmental modulation of the expression of twist. Both the domain of even-skipped function and the level of twist expression are regulated by sloppy-paired. sloppy-paired thus controls segmental allocation of mesodermal cells to different fates.

Validation of the St. George's Respiratory Questionnaire in bronchiectasis

There is no disease-specific instrument available for health status assessment in bronchiectasis. We examined the stability, validity and responsiveness of a measure designed for asthma and COPD, the St. George's Respiratory Questionnaire (SGRQ), in this condition. One hundred and eleven patients were studied on 2 separate d 6 mo apart. On both days each patient completed the SGRQ and measures of general and disease-specific health, mood, and fatigue. They also performed a shuttle walking test and comprehensive lung function tests. Repeatability was tested over 2 wk in 23 patients. The intraclass correlation (ri) for the SGRQ Total score was 0.97. The SGRQ component scores correlated well with relevant markers of disease activity. Examples include: SGRQ Symptoms score versus MRC Wheeze score, r = 0.634, p < 0.0001; Activity score versus shuttle walking test, r = -0.659, p < 0.0001; and impacts score versus physical fatigue, r = 0.610, p < 0.0001. Changes in the SGRQ Total score from entry to follow-up also correlated with changes in other measures of the patients' health. There were significant differences in the SGRQ total score between patients who improved and those who deteriorated over the 6 mo in respect to wheeze (F = 5.6, p < 0.01) and breathlessness (F = 6.05, p < 0.01). We conclude that the SGRQ reflects impaired health in bronchiectasis patients.

Functionally differentiating two neuronal nitric oxide synthase isoforms through antisense mapping: evidence for opposing NO actions on morphine analgesia and tolerance

Several isoforms of neuronal nitric oxide synthase (nNOS) have been identified. Antisense approaches have been developed which can selectively down-regulate nNOS-1, which corresponds to the full-length nNOS originally cloned from the brain, and nNOS-2, a truncated form lacking two exons which is generated by alternative splicing, as demonstrated by decreases in mRNA levels. Antisense treatment also lowers nNOS enzymatic activity. Down-regulation of nNOS-1 prevents the development of morphine tolerance. Whereas morphine analgesia is lost in control and mismatch-treated mice given daily morphine injections for 5 days, mice treated with antisense probes targeting nNOS-1 show no decrease in their morphine sensitivity over the same time period. Conversely, an antisense probe selectively targeting nNOS-2 blocks morphine analgesia, shifting the morphine dose-response curve over 2-fold to the right. Both systems are active at the spinal and the supraspinal levels. An antisense targeting inducible NOS is inactive. Studies with NG-nitro-L-arginine, which does not distinguish among NOS isoforms, indicate that the facilitating nNOS-2 system predominates at the spinal level while the inhibitory nNOS-1 system is the major supraspinal nNOS system. Thus, antisense mapping distinguishes at the functional level two isoforms of nNOS with opposing actions on morphine actions. The ability to selectively down-regulate splice variants opens many areas in the study of nNOS and other proteins.

Analysis of a meiosis-specific URS1 site: sequence requirements and involvement of replication protein A

URS1 is a transcriptional repressor site found in the promoters of a wide variety of yeast genes that are induced under stress conditions. In the context of meiotic promoters, URS1 sites act as repressor sequences during mitosis and function as activator sites during meiosis. We have investigated the sequence requirements of the URS1 site of the meiosis-specific HOP1 gene (URS1H) and have found differences compared with a URS1 site from a nonmeiotic gene. We have also observed that the sequence specificity for meiotic activation at this site differs from that for mitotic repression. Base pairs flanking the conserved core sequence enhance meiotic induction but are not required for mitotic repression of HOP1. Electrophoretic mobility shift assays of mitotic and meiotic cell extracts show a complex pattern of DNA-protein complexes, suggesting that several different protein factors bind specifically to the site. We have determined that one of the complexes of URS1H is formed by replication protein A (RPA). Although RPA binds to the double-stranded URS1H site in vitro, it has much higher affinity for single-stranded than for double-stranded URS1H, and one-hybrid assays suggest that RPA does not bind to this site at detectable levels in vivo. In addition, conditional-lethal mutations in RPA were found to have no effect on URS1H-mediated repression. These results suggest that although RPA binds to URS1H in vitro, it does not appear to have a functional role in transcriptional repression through this site in vivo.

Fringe modulates Notch-ligand interactions

The Notch family of transmembrane receptor proteins mediate developmental cell-fate decisions, and mutations in mammalian Notch genes have been implicated in leukaemia, breast cancer, stroke and dementia. During wing development in Drosophila, the Notch receptor is activated along the border between dorsal and ventral cells, leading to the specification of specialized cells that express Wingless (Wg) and organize wing growth and patterning. Three genes, fringe (fng), Serrate (Ser) and Delta (Dl), are involved in the cellular interactions leading to Notch activation. Ser and Dl encode transmembrane ligands for Notch, whereas fng encodes a pioneer protein. We have investigated the relationship between these genes by a combination of expression and coexpression studies in the Drosophila wing. We found that Ser and Dl maintain each other's expression by a positive feedback loop. fng is expressed specifically by dorsal cells and functions to position and restrict this feedback loop to the developing dorsal-ventral boundary. This is achieved by fng through a cell-autonomous mechanism that inhibits a cell's ability to respond to Serrate protein and potentiates its ability to respond to Delta protein.

A family of mammalian Fringe genes implicated in boundary determination and the Notch pathway

The formation of boundaries between groups of cells is a universal feature of metazoan development. Drosophila fringe modulates the activation of the Notch signal transduction pathway at the dorsal-ventral boundary of the wing imaginal disc. Three mammalian fringe-related family members have been cloned and characterized: Manic, Radical and Lunatic Fringe. Expression studies in mouse embryos support a conserved role for mammalian Fringe family members in participation in the Notch signaling pathway leading to boundary determination during segmentation. In mammalian cells, Drosophila fringe and the mouse Fringe proteins are subject to posttranslational regulation at the levels of differential secretion and proteolytic processing. When misexpressed in the developing Drosophila wing imaginal disc the mouse Fringe genes exhibit conserved and differential effects on boundary determination.

Nocturnal ophthalmic arterial hemodynamics in primary open-angle glaucoma

PURPOSE

Recent studies have found nocturnal reductions in systemic arterial blood pressure associated with progressive visual field loss in glaucoma. Although ocular ischemia has been hypothesized to link these two phenomena, it remains unknown if perfusion of the eye is reduced during the night in patients with glaucoma.

PATIENTS AND METHODS

Nine patients with primary open-angle glaucoma (POAG) and stable visual fields who were free from systemic hypertension, as well as nine age- and gender-matched controls, were studied at 9:00 P.M., and then during sleep at 12:00, 3:00, and 6:00 A.M. Systemic blood pressure, intraocular pressure (IOP), and color Doppler imaging (CDI) of the ophthalmic artery were measured at each time.

RESULTS

Arterial blood pressure and ophthalmic artery peak systolic and end-diastolic velocities were similar and were unchanged over time, in both groups. In contrast, the ophthalmic arterial resistance index decreased as the night progressed (p < 0.05), identically in controls and patients. In patients with glaucoma, CDI indices were independent of changes in arterial pressure, IOP, or calculated ocular perfusion pressure.

CONCLUSION

Patients with POAG characterized by stable visual fields who were free from systemic hypertension exhibited normal ophthalmic arterial hemodynamics at night; there was no evidence of ocular ischemia or vasoconstriction.

Resolution of acylated dipeptide stereoisomers by capillary electrophoresis using sulfobutylether derivatized beta-cyclodextrin

The separation of enantiomerically and diastereomerically related stereoisomers of acylated Asp-Phe dipeptides was explored using capillary electrophoresis (CE). This series of dipeptides included the alpha-L,L parent compound and the three other potential Asp containing stereoisomers (alpha-D,D, alpha-L,D, and alpha-D,L), as well the four possible isoAsp containing stereoisomers (beta-L,L, beta-D,D, beta-L,D and beta-D,L). The separation of these substances was explored using both neutral and charged cyclodextrins as the stereoisomer selector added to the running electrolyte. The major experimental parameters investigated included pH, the cyclodextrin type, and the cyclodextrin concentration. Due to differences in the pKa values of the carboxylic acid groups, adjustment of the separation buffer to between pH 3.0 and 4.0 provided for sufficient electrophoretic mobility differences to result in excellent separations of the diastereomerically related peptides in this pH region. The resolution of the enantiomerically related peptide stereoisomers was accomplished using low concentrations (1 mM) of the anionic cyclodextrin derivative, sulfobutylether-beta-cyclodextrin (SBE-beta-CD). This negatively charged cyclodextrin was found to be superior for the resolution of the enantiomerically related peptides as compared to native beta-cyclodextrin or the neutral derivatives, dimethyl beta-cyclodextrin and hydroxypropyl beta-cyclodextrin. An alternative approach using anionic or neutral surfactants in conjunction with the SBE-beta-CDs was also explored and found to be successful but problematic.

Quantitative gas chromatography-mass spectrometry isomer-specific measurement of hydroxy fatty acids in biological samples and food as a marker of lipid peroxidation

We have developed a capillary gas chromatography-mass spectrometry method for the quantitative analysis of individual positional isomers of monohydroxy fatty acids derived from linoleic, arachidonic, eicosapentaenoic, or docosahexaenoic acid. Peroxidation of a particular polyunsaturated fatty acid results already in a complex mixture of positional isomers of hydroperoxy and hydroxy fatty acids. Catalytic hydrogenation of lipid extracts produces stable saturated hydroxy lipids from the complex mixtures typical of oxidized biological samples, simultaneously simplifying the analytical problem and eliminating oxidation artifacts. After saponification and methylation, monohydroxy fatty acid methyl esters are purified by solid-phase extraction and partially resolved using a CP Sil 19 column following on-column derivatization of the hydroxy groups with tetramethylammonium hydroxide. The resulting methoxy fatty acid methyl esters are subjected to electron impact mass spectroscopy. Two characteristic ions are produced for each positional isomer. Quantitative measurements were achieved by using odd chain C17 and C19 monohydroxy fatty acids as internal standards. The limit of detection of individual hydroxy fatty acid isomers is dependent on the total number of ions monitored. Monitoring 11 pairs of ions simultaneously gives limits of detection of 10 ng. Sensitivity is much higher by monitoring fewer ions and as little as 0.2 ng of a single isomer can be detected. The method has been applied for the quantitative analysis of hydroxy (plus hydroperoxy) fatty acids in plasma, adipose tissue, oils, and foods. To date over 1000 samples have been analyzed using the method described in this paper.

Roles of replication protein-A subunits 2 and 3 in DNA replication fork movement in Saccharomyces cerevisiae

Replication Protein-A, the eukaryotic SSB, consists of a large subunit (RPA1) with strong ssDNA binding activity and two smaller subunits (RPA2 and 3) that may cooperate with RPA1 to bind ssDNA in a higher-order mode. To determine the in vivo function of the two smaller subunits and the potential role of higher-order ssDNA binding, we isolated an assortment of heat-lethal mutations in the genes encoding RPA2 and RPA3. At the permissive temperature, the mutants show a range of effects on DNA replication fidelity and sensitivities to UV and MMS. At the nonpermissive temperature, four out of five RPA2 mutants show a fast-stop DNA synthesis phenotype typical of a replication fork block. In contrast, the fifth RPA2 mutant and all RPA3 mutants are able to complete at least one round of DNA replication at the nonpermissive temperature. The effect of these mutations on the stability of the RPA complex was tested using a coprecipitation assay. At the nonpermissive temperature, we find that RPA1 and RPA2 are dissociated in the fast-stop mutants, but not in the slow-stop mutants. Thus, replication fork movement in vivo requires the association of at least two subunits of RPA. This result is consistent with the hypothesis that RPA functions in vivo by binding ssDNA in a higher-order mode.

Mathematics instruction for secondary students with learning disabilities

Secondary students with learning disabilities generally make inadequate progress in mathematics. Their achievement is often limited by a variety of factors, including prior low achievement, low expectations for success, and inadequate instruction. This article will discuss techniques that have been demonstrated to be effective with secondary students who have learning disabilities in mathematics.

Blockade of morphine-induced hindlimb myoclonic seizures in mice by ketamine

Morphine administration can lead to a variety of side-effects, including myoclonus. In an animal model, high morphine doses given intrathecally elicit hindlimb myoclonic seizures which are not influenced by traditional opioid receptor antagonists, such as naloxone. Ketamine prevents this seizure-like activity in a dose-dependent manner. The response is stereoselective, with S-ketamine far more potent than R-ketamine. A competitive NMDA antagonist, NPC17742, also prevents the seizures, although less potently than ketamine. Dextromethorphan has limited activity in this model, while haloperidol and pentothal are without any effect.

Bacterial infections of the bronchial tree

In health, bacteria colonize the upper respiratory tract, but the lower respiratory tract defenses keep the lung sterile from the first bronchial division, despite being regularly challenged by bacteria from the nasopharynx and the environment. Bronchial infections reflect a failure that can be ascribed either to the virulence of the bacterium or to a deficiency of one or more of these defenses. An abnormality of the airway defenses, which may be inherited (e.g., cystic fibrosis) or acquired (e.g., following a viral infection or cigarette smoking), is present in most patients with bronchial infection, and this fact should be considered when planning investigation.

The effects of dietary boron on bone strength in rats

Previous studies from our laboratory found that when boric acid (BA) was administered in the diet to rats, boron levels in bone were approximately fourfold greater than serum levels. The current studies were undertaken to determine if these elevations produced adverse effects on several bone-related measures, including serum electrolyte levels, bone structure, and bone strength. Data from two studies are presented: in the first study, young adult male rats consumed a powdered diet containing 0, 3000, 4500, 6000, or 9000 ppm BA for 9 weeks. Endpoints were serum calcium, phosphorous, potassium, and chloride, as well as blood and bone boron concentrations ([B]) measured weekly during the 9-week exposure period, and at 8, 16, 24, and 32 weeks after the end of exposure. In the second study, the male and female young adult rats diet contained 0, 200, 1000, 3000, or 9000 ppm BA for 12 weeks; endpoints measured weekly were serum levels of calcium, phosphorous, and magnesium, bone [B], and bone structure (humerus) and strength (tibia, femur, and lumbar vertebrae). In treated rats, calcium was reduced in the first study but not the second. Serum phosphorous was reduced in both studies; potassium was unchanged, chloride was increased by 1%, and magnesium was reduced in all BA-exposed groups in the second study, to a maximal 19% reduction. Bone [B] was consistently increased in all treated groups, to concentrations approximately fourfold those of serum. After cessation of exposure, serum and urinary boron concentrations dropped to within control values within a week. However, even 32 weeks after the end of exposure, bone [B] remained threefold greater than controls. Male tibia and femur resistance to bending was unchanged. However, vertebral strength in compression was significantly increased by 5-10% in all dose groups (200 to 9000 ppm). The pattern was substantially similar in females. Only the humerus was examined by light microscopy and was found to be unchanged at any level of BA consumption. These data show that, despite a reduction in some serum electrolyte levels, BA consumption increased vertebral resistance to crush force, without detectably altering the microscopic structure of the humerus or the resistance of femur and tibia to a bending load. This increase in compression resistance occurred at exposure levels substantially below those that were previously reported to be reproductively toxic.

Architectural and mechanical properties of the rat adductor longus: response to weight-lifting training

BACKGROUND

The primary objective of this study was to determine the effects of an 8 week weight-lifting program on the mechanical, histochemical, and architectural properties of the rat adductor longus muscle, a predominantly slow adductor muscle.

METHODS

The weight-lifting program was progressive such that the rats were performing three bouts of ten lifts with 300% body weight load every other day during the last 3 weeks of training. The in situ mechanical properties, fiber type composition, and architectural characteristics of the muscle were determined in control and weight-trained rats. Intramuscular electromyographic recordings were used to verify the recruitment of the adductor longus during the lifting task.

RESULTS

The adductor longus was composed predominantly of slow fibers (approximately 80% slow oxidative) and had a relatively simple architectural design, i.e., one motor end-plate band near the center of the muscle, virtually no angle of pinnation of the fibers from the line of pull, and a fiber length:muscle length ratio of 0.72. The mean fiber type composition and fiber size, the total fiber number, and the mean physiological cross-sectional area of the adductor longus were similar in the two groups of rats. The mean body weight of weight-lifting rats was significantly less than control. The weight of the adductor longus relative to body weight and its fatigue resistance were higher and the maximum rate of shortening was slower in weight-lifting than in control rats. No other mechanical property was significantly affected by the training program.

CONCLUSIONS

The results indicate that approximately 1 minute of over-load every other day by physiological recruitment of motor units can induce remodeling of the adductor longus of growing rats; i.e., the trained muscles were slower and less fatigable than control. Given that the effects on the architectural or force-generating properties of the muscles were small, the marked improvement in the ability to lift heavier loads as the training progressed appears to be more attributable to neurally related than to muscle-related phenomena.

Ovarian luteal cell toxicity of ethylene glycol monomethyl ether and methoxy acetic acid in vivo and in vitro

These studies define the site and mechanisms of reproductive toxicity of ethylene glycol monomethyl ether (EGME) in a nongravid female animal model using in vivo and in vitro methods. In vivo studies assessed vaginal cytology and histology, ovarian histology, and serum hormones in 80- to 90-day-old, adult, regularly cycling, female Sprague-Dawley rats treated daily with EGME or vehicle by oral gavage. Dose-response and time-course studies (four to nine rats per group per treatment) determined that 300 mg/kg EGME suppressed cyclicity without systemic toxicity within 3 to 8 days, and doses less than 100 mg/kg had no effect. Pathogenesis studies (six to nine rats per time and treatment) determined that 300 mg/kg EGME elevated serum progesterone within 32 hr after dosing, while serum estradiol, FSH, LH, and prolactin remained at baseline levels. In EGME-treated rats, cyclicity was suppressed, ovulation was inhibited, and corpora lutea were hypertrophied. Thus, EGME appeared to target the ovarian luteal cell. To further examine the toxicity in vitro, luteal cells were recovered from 23-day-old, hCG-primed Sprague-Dawley rats and treated with 0-10 mM methoxy acetic acid (MAA), the proximate toxic metabolite of EGME. MAA (1-10 mM) maintained elevated progesterone levels as production declined in untreated cells at 24 and 48 hr of culture. Progesterone production was maintained independent of LH-stimulated cAMP levels. MAA decreased ATP, but only at 48 hr and at 2.5 mM or greater concentrations. Thus, these studies establish that the ovarian luteal cell is a target of EGME and MAA in vivo and in vitro and that the effect on luteal cell progesterone production is likely independent of LH-stimulated cAMP pathways.