Coregistration of quantitative proton magnetic resonance spectroscopic imaging with neuropathological and neurophysiological analyses defines the extent of neuronal impairments in murine human immunodeficiency virus type-1 encephalitis

Relatively few immune-activated and virus-infected mononuclear phagocytes (MP; perivascular macrophages and microglia) may affect widespread neuronal dysfunction during human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD). Indeed, histopathological evidence of neuronal dropout often belies the extent of cognitive impairment. To define relationships between neuronal function and histopathology, proton magnetic resonance spectroscopic imaging (1H MRSI) and hippocampal long-term potentiation (LTP) were compared with neuronal and glial immunohistology in a murine model of HIV-1 encephalitis (HIVE). HIV-1(ADA)-infected human monocyte-derived macrophages (MDM) were stereotactically injected into the subcortex of severe combined immunodeficient (SCID) mice. Sham-operated and unmanipulated mice served as controls. Seven days after cell injection, brain histological analyses revealed a focal giant cell encephalitis, with reactive astrocytes, microgliosis, and neuronal dropout. Strikingly, significant reductions in N-acetyl aspartate concentration ([NAA]) and LTP levels in HIVE mice were in both injected and contralateral hemispheres and in brain subregions, including the hippocampus, where neuropathology was limited or absent. The data support the importance of 1H MRSI as a tool for assessing neuronal function for HAD. The data also demonstrate that a highly focal encephalitis can produce global deficits for neuronal function and metabolism.

Microbiological, molecular biological and stable isotopic evidence for nitrogen fixation in the open waters of Lake Michigan

We have used a combination of microbiological, molecular biological and stable isotope methods to relate specific microbial populations to elemental cycling at an offshore site in Lake Michigan. Several lines of evidence suggest that atmospheric N2 may be a significant source of nitrogen to the lake. Particulate organic nitrogen (PON) at approximately equals 10-15m depth in July and October had a delta15N of 0.5-1.5%o. These values closely reflect the 15N composition of atmospheric N2, suggesting biological nitrogen fixation. Historical data show a developing late-summer N:P minimum at approximately equals 15 m; low abundance of inorganic nitrogen relative to phosphorus favours species able to acquire atmospheric nitrogen. Microscopic examination of October water samples revealed abundant heterocystous cyanobacteria, including Nodularia sp. Potentially nitrogen-fixing Anabaena spp. have been found in Lake Michigan before but, to our knowledge, this is the first report of Nodularia. Finally, we have amplified both cyanobacterial and non-cyanobacterial nifH sequences (encoding the nitrogenase iron protein) from lakewater samples, evidence for the presence of bacteria capable of nitrogen fixation. The surface waters of Lake Michigan are considered to be phosphate limited in the stratified season and, under these conditions, energetically expensive nitrogen fixation is expected to be uncompetitive with assimilation of combined nitrogen. Our results suggest that, from both microbiological and biogeochemical perspectives, this may be an oversimplification.

Comparable efficacy of administration with face mask or mouthpiece of nebulized budesonide inhalation suspension for infants and young children with persistent asthma

A randomized, double-blind, placebo-controlled, parallel-group study including 481 children at 37 centers in the United States demonstrated the efficacy and safety of budesonide inhalation suspension in doses of 0.25 mg once daily, 0.25 mg twice daily, 0.5 mg twice daily, and 1.0 mg daily in infants and young children with persistent asthma. The retrospective analysis presented here compares the efficacy of treatment with the suspension administered through a face mask or mouthpiece. All patients receiving budesonide inhalation suspension via face mask or mouthpiece showed clinical improvements in nighttime and daytime asthma symptoms as compared with administration of a placebo. The improvements were of similar magnitude as those observed in an analysis of all patients treated. Improvements in nighttime asthma symptoms were statistically significant with budesonide at 0.25 mg daily (p = 0.040), 0.25 mg twice daily (p = 0.008), and 0.5 mg twice daily (p = 0.046) delivered by face mask. In patients using mouthpieces, nighttime asthma symptoms improved significantly in the 0.25-mg twice-daily (p = 0.005) and 1.0-mg daily (p = 0.035) groups. Patients receiving budesonide at 0.5 mg twice daily via a face mask improved significantly in daytime asthma symptoms (p = 0.009). The use of breakthrough medication was reduced in patients receiving budesonide via face masks or mouthpieces relative to placebo, and treatment was well tolerated in all study groups. This retrospective analysis suggests that nebulized budesonide inhalation suspension can be administered effectively by either face mask or mouthpiece to young children with persistent asthma.

Efficacy of budesonide inhalation suspension in infants and young children with persistent asthma. Budesonide Inhalation Suspension Study Group

This paper reviews the results from 3 randomized, double-blind, placebo-controlled, multicenter studies that assessed the efficacy and safety of once- and twice-daily dosing of budesonide inhalation suspension (BIS) in infants and young children with persistent asthma. In children with mild persistent asthma that was previously treated with bronchodilators or noncorticosteroid anti-inflammatory agents (study A), nighttime and daytime asthma symptoms were significantly improved in 0.25-mg once daily, 0.5-mg once daily, and 1.0-mg once daily BIS treatment groups compared with placebo (P </=. 05). Rescue medications were used significantly less in all BIS groups (approximately 2 days of every 14 days) compared with placebo (P <.05). The proportion of patients who discontinued this therapy because of worsening asthma was greater in the placebo group than in the BIS groups, with the difference between placebo (23%) and the 1. 0-mg BIS group (13%) being statistically significant (P =.020). All BIS doses except 0.5 mg once daily showed nonsignificant numeric improvement in morning and evening peak expiratory flow (PEF) compared with placebo. In children with asthma that was previously treated with inhaled corticosteroids (study B), BIS doses of 0.25 mg, 0.5 mg, and 1.0 mg twice daily resulted in significant improvements in nighttime symptoms scores versus placebo (P </=.026). Rescue medications were used significantly less in all BIS groups (approximately 2.5 to 3.5 days of every 14 days) compared with placebo (P </=.032). The proportion of patients receiving placebo who discontinued therapy because of worsening asthma symptoms (36%) was significantly greater compared with the BIS groups (9%; P </=. 015). Morning PEF levels were significantly greater in each BIS group compared with placebo (P </=.03). For evening PEF levels, all BIS treatment groups showed numeric improvements compared with placebo; the 0.25-mg twice daily budesonide group showed statistically significant improvement (P <.05). In children with moderate persistent asthma that was previously maintained either on bronchodilators or inhaled corticosteroids (study C), nighttime asthma symptoms significantly improved in the 0.25-mg twice daily, 0. 5-mg twice daily, and 1.0-mg once daily BIS groups compared with placebo (P <.01); there was a numeric improvement for the 0.25-mg once daily treatment group. Rescue medications were used significantly less in all BIS groups (approximately 2 to 3 days of every 14 days) compared with placebo (P </=.014). The proportion of patients who discontinued treatment because of worsening of asthma symptoms was greater in the placebo group than in the BIS groups; the difference between 0.25-mg twice daily group (13%) and the placebo group (26%) was statistically significant (P =.029). All BIS doses showed numeric improvement in morning PEF levels, and statistically significant improvements were observed in the 0.25-mg twice daily, 0.5-mg twice daily, and 1.0-mg once daily groups compared with placebo (P <.03). Significant improvements in evening PEF levels were observed for each BIS treatment group (P </=.034), except for the 1.0-mg once daily group. Overall, the 3 studies show that once- and twice-daily dosing of BIS effectively relieves asthma symptoms and improves pulmonary function in infants and young children with mild-to-severe persistent asthma.

A multiple-dosing, placebo-controlled study of budesonide inhalation suspension given once or twice daily for treatment of persistent asthma in young children and infants

RATIONALE

Topical antiinflammatory medications such as inhaled corticosteroids are recommended for therapy of asthma, but no formulation suitable for administration to infants and young children is available in the United States.

METHODS

This was a 12-week, multicenter, double-blind, randomized, parallel-group study comparing the efficacy and safety of four dosing regimens of bude-sonide inhalation suspension (BIS) or placebo in 480 asthmatic infants and children (64% boys), ages 6 months to 8 years, with moderate persistent asthma. Approximately 30% of children were previously on inhaled corticosteroids that were discontinued before the study. Active treatments were comprised of BIS 0.25 mg once daily (QD), 0.25 mg twice a day (BID), 0.5 mg BID, or 1.0 mg QD. Efficacy was assessed by twice daily recording at home of asthma symptom scores and use of rescue medication, and discontinuation from the study because of worsening asthma and/or a requirement for systemic steroids. Peak flow measurements were recorded twice daily on diary and spirometry was recorded at clinic visits for those children able to perform these tests. Safety was assessed by reported adverse events and by cortisol testing (adrenocorticotropic hormone stimulation) in a subset of patients.

RESULTS

Patients enrolled had an average duration of asthma of 34 months; the mean asthma symptom score was approximately 1.3 (scale of 0-3). All dosing regimens with BIS produced statistically significant improvement in various clinical efficacy measures for asthma control compared with placebo. The lowest dose used, 0.25 mg QD, was efficacious but with fewer efficacy parameters than seen with the other doses administered. Separation between active treatment and placebo in daytime and nighttime symptom scores were observed by week 2 of treatment for all BIS treatment regimens. A significant increase in peak flow measurement was observed in most active treatment groups compared with placebo in the subset of children able to do pulmonary function testing. All treatment groups showed numerical improvement in forced expiratory volume in 1 second but only the 0.5-mg BID dose was significantly different from placebo. Adverse events for the entire group and response to adrenocorticotropic hormone in a subgroup of children who underwent cortisol testing before and at the end of the treatment period were no different in budesonide-treated patients in comparison to placebo.

CONCLUSION

Results of this study demonstrate that BIS is effective and safe for infants and young children with moderate persistent asthma in a multiple dose range, and that QD dosing is an important option to be considered by the prescribing physician.

Diversity of heterotrophic nitrogen fixation genes in a marine cyanobacterial mat

The diversity of nitrogenase genes in a marine cyanobacterial mat was investigated through amplification of a fragment of nifH, which encodes the Fe protein of the nitrogenase complex. The amplified nifH products were characterized by DNA sequencing and were compared with the sequences of nitrogenase genes from cultivated organisms. Phylogenetic analysis showed that similar organisms clustered together, with the exception that anaerobic bacteria clustered together, even though they represented firmicutes, (delta)-proteobacteria, and (gamma)-proteobacteria. Mat nifH sequences were most closely related to those of the anaerobes, with a few being most closely related to the cluster of (gamma)-proteobacteria containing Klebsiella and Azotobacter species. No cyanobacterial nifH sequences were found from the mat collected in November when Microcoleus chthonoplastes was the dominant cyanobacterium, but sequences closely related to the cyanobacterium Lyngbya lagerheimeii were found during summer, when a Lyngbya strain was dominant. The results indicate that there is a high diversity of heterotrophic nitrogen-fixing organisms in marine cyanobacterial mats.

Identification of a zinc finger protein that inhibits IL-2 gene expression

Transient activation of the interleukin-2 (IL-2) gene after antigen recognition by T lymphocytes is crucial for subsequent T cell proliferation and differentiation. Several IL-2 gene regulatory elements and binding factors necessary for activation of the IL-2 gene have been defined. However, little is known about negative regulation of IL-2 expression, which is likely to be important in the rapid shut-off of IL-2 transcription. A nucleotide sequence element (NRE-A) that negatively regulates IL-2 expression has been identified within the IL-2 gene. T cell nuclear extracts contained an NRE-A binding activity. A complementary DNA was isolated that encodes a zinc finger-containing protein that suppressed IL-2 gene expression. The observation of negative regulation of the immunoglobulin heavy chain gene enhancer by an element similar to NRE-A suggests that related proteins may regulate multiple immune response genes.

DNA sequencing in HydroLink matrices: extension of reading ability to greater than 600 nucleotides

All the systems for optimizing DNA sequencing published so far have introduced modifications regarding: (i) linearization of band migration via ionic strength gradients or wedge-shaped gels; (ii) automatization of band reading via introduction of fluorescent probes; (iii) direct blotting analysis; (iv) pulsed electric fields and (v) discontinuous buffer systems. In all these systems, DNA sequence reading with an accuracy of ca. 98% rarely exceeds a length of 350 bases. We have chosen, in order to increase the reading ability of a single gel, to manipulate the characteristics of the gel matrix. The Seq-HydroLink gel formation here reported allows optimal reading, from a single gel run, of at least 600 bases. In order to guarantee this reading ability in a single run, the upper and lower ends of the ladder are time-resolved, i.e. the same sample is applied to the gel matrix at three different time intervals. The present system represents an increase of at least 30% in reading ability as compared with any type of polyacrylamide gel formulation so far reported.

A multicenter evaluation of the clinical benefits of cromolyn sodium aerosol by metered-dose inhaler in the treatment of asthma

The efficacy and safety of cromolyn sodium by metered-dose inhaler (MDI) (1 mg per actuation) was evaluated with a double-blind, placebo-controlled, parallel-study design. Subjects with asthma, aged 8 to 58 years, whose asthma was well controlled taking cromolyn sodium capsules by Spinhaler turboinhaler, plus beta 2-agonists, entered the study after being maintained with cromolyn sodium capsules for a minimum of 4 weeks. The investigation began with a 2-week control interval with cromolyn sodium capsules followed by a 4-week single-blind period with placebo capsules. Subjects whose asthma significantly worsened while they were receiving placebo therapy were then randomized to a 10-week double-blind phase in which they received either active cromolyn sodium or placebo by MDI. Efficacy variables included diary data, physician evaluation, and spirometry. Comparisons were made between baseline period scores and each assessment variable over time. Of 155 subjects entered, 93 qualified for the double-blind, randomized phase. Eighty-three subjects completed the study and were analyzed. At baseline there existed no significant differences between the active-treatment and placebo-treatment groups. Significant differences (p less than 0.05) in favor of the cromolyn sodium-treatment group, however, were noted at all time points for daily diary symptoms (cough, breathlessness, and overall asthma severity), physician's assessments at each clinic visit, physician's and patient's overall final assessments, FEV1 at each clinic visit, and FVC and peak expiratory flow rate at the final visit. Concomitant bronchodilator medication use was less in the cromolyn sodium-treatment group. Cromolyn sodium by MDI is highly effective for (1) controlling asthmatic symptoms, (2) improving lung functions, and (3) decreasing the need for concomitant bronchodilators.

Long-term studies in prevention of food allergy: patterns of IgG anti-cow's milk antibody responses

Over the past 7 years we have enrolled several hundred families in a study of the prophylaxis of atopic allergy. Initially, control and study patients were at different institutions, but more recently a true double-blind random assignment to control or study group has been instituted. Nevertheless, all of the infants from these highly atopic families can be utilized to obtain the data reported; that is, the rate of change of IgE levels, the appearance of food sensitization (food-specific IgE), the signs and symptoms of atopic allergy diseases and the changes in cow's milk-specific IgG antibody during the first 2 years of life. Some aspects of the first three of these parameters have been presented in the eight references to this paper, but only preliminary data on the use of IgG anti-cow's milk antibody as a measure of compliance has been available. In this paper an analysis is presented of the various patterns of IgG antibody levels in the first 60 infants of the over 200 who have been studied to date. Both the age of onset and the subsequent changes in the foregoing immunologic measurements provide fundamental data with which to measure the success rate of any prophylactic or therapeutic regimen and may improve our capacity to predict the future course of infants and children with a strong familial tendency to allergy.

The effectiveness of nalbuphine and hydroxyzine for the emergency treatment of severe headache

The present treatment for acute attacks of headache is empiric. Intramuscular nalbuphine (Nubain) and hydroxyzine (Vistaril) were assessed for pain relief in a prospective, double-blind clinical trial. Ninety-four patients were assigned randomly to treatment groups receiving nalbuphine 10 mg, nalbuphine 10 mg plus hydroxyzine 50 mg, hydroxyzine 50 mg, or placebo. The treatment groups were found to be adequately homogenous with regard to age, sex, type and duration of headaches, and history of prior narcotic use. All data were analyzed by one-way analysis of variance. Patients who had headaches diagnosed as other than classic migraine had significantly greater pain relief with nalbuphine compared to placebo (P less than .01). The combination of nalbuphine and hydroxyzine was not significantly more effective than other treatment groups. In 20 patients with classic migraine, none of the treatment regimens significantly outperformed placebo. There were no clinically significant adverse effects attributed to the study drugs. These findings are similar to others that showed a lack of efficacy of kappa receptor agonists in classic migraineurs. Nalbuphine appears to be clinically useful in other types of severe headache. This study does not support the routine addition of hydroxyzine for presumed synergistic effect.

Effectiveness of dietary manipulation in the prevention of food allergy in infants

The desire to alter the natural incidence of atopic illness has piqued physicians' imaginations for decades. Specifically, the phenotypic expression of IgE-mediated disorders, which appears regulated by multiple genetic factors and modulated by environmental experiences (allergen exposure, infection, and smoking), has been a target for preventive medicine since the 1920s when dietary intervention was espoused in infancy. To be successful, such intervention must overcome many patient factors that in concert markedly increase the risk for development of atopic disease (Table XII). During the past 60 years, much controversy has emerged from multiple clinical studies designed to evaluate the effect of dietary and other environmental exclusions on the subsequent manifestation of atopy. One may conservatively conclude, from critical evaluation of these conflicting studies, that sole breast feeding for about 6 months combined with delayed introduction of solid foods for at least 6 months may reduce atopic dermatitis and food allergy in early infancy. A randomized, prospective study of allergy prophylaxis during infancy is mandatory to determine definitely the benefits and feasibility of such a regimen and its long-term effects on the development of atopy. From our recent findings, which demonstrate the development of atopy in infants entered in a strict prophylactic protocol, it becomes apparent that monumental obstacles confront preventive efforts to overcome the strength of the allergic constitution. In the very near future, results from our prospective study of prenatally randomized allergy prophylaxis should be available for critical scrutiny of the effectiveness and feasibility of allergy prevention during infancy.

Management of acute severe asthma

Discussed in this article are the pathophysiology of acute asthma and its differential diagnosis and management, placing special emphasis on rapid assessment, prompt and decisive therapeutic intervention, and on recognition of the severity of the disease.

Intranasal flunisolide in the treatment of perennial rhinitis: Correlation with immunologic parameters

The effectiveness and safety of 200 micrograms/day of intranasal flunisolide in the treatment of perennial rhinitis was studied in 56 patients in a 6 wk double-blind parallel vehicle controlled clinical trial. In addition, patients failing to respond to placebo were entered into a 6 wk open trial with the active drug. Forty-six percent of the flunisolide-treated patients achieved total or substantial control of their nasal symptoms compared to 11% of the placebo-treated group in the double-blind study (p = 0.031). Eighty percent of patients achieved total or substantial control of their nasal symptoms in the 6 wk open study. No adverse effects attributable to flunisolide were observed. Parameters of IgE-mediated reactivity, including immediate-type skin test reactivity, total serum and nasal secretion IgE, specific serum and nasal secretion IgE, and nasal eosinophilia, were also assessed in these patients. Although benefit from flunisolide significantly correlated with all of these parameters except specific serum IgE, the absence of these findings did not preclude significant benefit from the drug. This study demonstrates the efficacy and safety of intranasal flunisolide in the treatment of perennial rhinitis, especially but not exclusively in those patients with evidence of IgE-mediated reactivity.

Cyclic nucleotides, thioldisulfide status of proteins, and cellular control processes

It is shown that cyclic nucleotides can have a variety of effects on cell division, cell shape, cell adhesion, and cell movement, depending on the cells selected and the conditions under which they are used. For example, while CHO cells elongate under the influence of exogenous dibutyryl CAMP, Y-1 adrenal tumor cells round up and polyoma-transformed 3T3 cells show no change in shape. The totality of experience with cyclic nucleotides suggests that where they have been used by cells as control elements involving the four processes listed above, they are superimposed on basic cellular processes that progress in their absence--that is, they must be acting indirectly. In attempting to understand the inhibitory action of methyl xanthines on egg development, we were forced to abandon the idea that they acted through cyclic nucleotides. We found that methyl xanthines inhibited the activation of glutathione reductase and that glutathione oxidizing agents act as mitotic inhibitors. Further, we found that tubulin polymerizability, NAD-kinase activity, and a mitotic apparatus associated Ca+2-ATP-ase were all inhibited by oxidation of some of their sulfhydryls and were activated by reduction of the resulting disulfides. These results are discussed in terms of reported cycles and activations of glutathione reductase (GR) in cells and reports that mixed disulfides of glutathione and proteins can act as substrates for GR. Using the fact that a CAMP-dependent protein kinase has been reported to be activated by glutathione, we have suggested potential sites where sulfhydryl control processes and cyclic nucleotide control processes and cyclic nucleotide control processes may interact in certain restricted cases.