Ultrasonographic features of gallbladder wall thickening in dogs with hypoalbuminemia

Hypoalbuminemia has been considered as a cause of gallbladder wall thickening in humans and dogs. Recent study revealed that gallbladder wall thickening in dogs with hypoalbuminemia may not be associated with serum albumin/plasma levels within 48 h of ultrasound study. However, gallbladder wall edema may change within 48 h, and the ultrasonographic features of gallbladder wall thickening in dogs with hypoalbuminemia have not been reported. The purpose of this study is to describe the relationship between serum albumin levels within 24 h of ultrasound and gallbladder wall thickening, and to describe the ultrasonographic features of thickened gallbladder walls in dogs with hypoalbuminemia. 37 hypoalbuminemic dogs with gallbladder ultrasound images were retrospectively included. Ultrasound studies were reviewed, and gallbladder wall thickness, layering appearance, echogenicity, echotexture, distribution, evidence of gallbladder mucocele, and presence of peritoneal effusion were recorded. Additionally, serum albumin levels within 24 h of ultrasound study and the administerd sedation were recorded. The prevalence of gallbladder wall thickening in dogs with hypoalbuminemia was 13.5%. The 3-layer appearance of the gallbladder wall was observed in 4 dogs, and a single-layer gallbladder wall thickening in one dog. Diffuse thickening was observed in all 5 dogs. The serum albumin level of dogs with gallbladder wall thickening was not different (p = 0.14) from dogs without thickening. Gallbladder wall thickening was not common, occurring only with mild hypoalbuminemia, and was commonly associated with a 3-layer appearance and considered as gallbladder wall subserosal edema. Causes other than hypoalbuminemia may be responsible for thickening of the gallbladder wall in dogs with hypoalbuminemia.

Concentrations and kinetics of renal biomarkers in dogs with gastric dilatation-volvulus with and without 24-h intravenous lidocaine

Background

Gastric dilatation volvulus (GDV) can lead to organ failure including acute kidney injury (AKI). Due to its cytoprotective, antioxidant and anti-inflammatory effects, lidocaine has a potential to prevent AKI in dogs with GDV.

Design and setting

Prospective, observational cohort study in client-owned dogs with GDV.

Objective

To determine concentrations of renal biomarkers for AKI in dogs with GDV with and without intravenous (IV) lidocaine therapy.

Methods

Thirty-two dogs were randomized to receive either IV lidocaine (2 mg/kg, followed by a lidocaine constant rate infusion at a dose of 50 μg/kg/min over 24 h; n = 17) or no lidocaine (n = 15). Blood and urine samples were taken at admission (T 0) (only blood), during or immediately after surgery (T 1), and 24 (T 24) and 48 (T 48) h after surgery. Plasma creatinine (pCr), plasma neutrophil gelatinase-associated lipocalin (pNGAL), urinary NGAL (uNGAL), uNGAL to creatinine ratio (UNCR), and urinary gamma-glutamyl transferase to creatinine ratio (uGGT/uCr) were evaluated. Biomarker concentrations were compared between dogs with and without IV lidocaine and the course of each marker was determined in comparison to its admission value.

Results

In the entire population, a significantly higher pCr at T 0 (median, 95 μmol/L, interquartile range, 82-105) compared with T 1 (69 μmol/L, 60-78), T 24 (63 μmol/L, 52-78), and T 48 (78 μmol/L, 65-87) (P < 0.001) was found. Plasma NGAL increased significantly between T 0 (5.66 ng/mL, 3.58-7.43) and T 24 (7.50 ng/mL, 4.01-11.89) (P = 0.006) and T 48 (9.86 ng/mL, 5.52-13.92) (P < 0.001), respectively. Urinary NGAL increased significantly between T 1 (0.61 ng/mL, 0.30-2.59) and T 24 (2.62 ng/mL, 1.86-10.92) (P = 0.001) and T 48 (4.79 ng/mL, 1.96-34.97 (P < 0.001), respectively. UNCR increased significantly between T 1 (0.15 μg/mmol, 0.09-0.54) and T 24 (1.14 μg/mmol, 0.41-3.58) (P = 0.0015) and T 48 (1.34 μg/mmol, 0.30-7.42) (P < 0.001), respectively. Concentrations of uGGT/uCr increased significantly from T 0 highest at T 24 (6.20 U/mmol, 3.90-9.90) and significantly decreased at T 48 (3.76 U/mmol, 2.84-6.22) (P < 0.001). No significant differences in any renal biomarker concentration were found between dogs with and without IV lidocaine therapy.

Conclusion and clinical relevance

Plasma NGAL, uNGAL and UNCR remained increased up to 48 h post-surgery. No evidence of lidocaine-associated renoprotection was found.

ARTEC-A furnace module for directional solidification and quenching experiments in microgravity

A new experimental design for directional solidification experiments with high cooling rates under microgravity conditions is presented. The aerogel-based furnace module ARTEC (AeRogel TEchnology for Cast alloys) developed at DLR extends the earlier presented sounding rocket facility ARTEX by enabling a transition from low to high solidification velocities and a simultaneous operation of five independent furnaces in the same sounding rocket module. The furnaces for directional solidification are equipped with thermally insulating aerogels as a crucible material. Their optical transparency allows the control of the solidification parameters (velocity and temperature gradient) with optical methods in the lab. In ARTEC, a drastically increased solidification velocity is achieved by contacting the sample with a movable cooling-rod during processing. Therefore, a better theoretical understanding of the influence of a sudden change in solidification velocity on microstructure formation is obtained. Carrying out experiments in microgravity gives access to purely diffusive solidification conditions. Hence, convection free-growth can be compared with growth subject to natural (earth) and/or forced-convection (earth and space). Furthermore, alloys with high density differences in their alloy components and, hence, also between the primary solidifying phase and the surrounding liquid can be studied without the negative influence of fluid-flow or macrosegregation being present.

Clinical and histopathologic findings in dogs with the ultrasonographic appearance of gastric muscularis unorganized hyperechoic striations

Background

Ultrasonographic appearance of unorganized hyperechoic striations (UHS) has been observed in the canine gastric muscularis layer. The purpose of the study was to determine the prevalence, sonographic and postmortem histologic features, and to determine the clinical significance of canine gastric muscularis UHS. In the prospective study, 72 dogs were included. The presence of gastric muscularis UHS were reviewed to determine its distribution and location. In the retrospective study, 167 dogs that had both abdominal ultrasonography and necropsy were included.

Results

The prevalence of gastric muscularis UHS in dogs was 37.5% in the prospective and 5.4% in the retrospective studies respectively. The higher prevalence in prospective study was due to greater anticipation by the radiologists in search for gastric muscularis UHS. In the ventral gastric wall, the muscularis UHS were better defined when the gastric lumen was empty or non-distended, and were mostly parallel with the serosa when the gastric wall was distended (with gas or fluid). Visualization of the dorsal gastric wall was often obscured by gas shadowing from luminal gas. Histopathology was performed on eight dogs with gastric muscularis UHS, three of which had fibrous tissue observed with Masson’s trichrome stain.

Conclusion

Presence of gastric muscularis UHS in dogs may have been attributable to presence of incomplete interfaces between the inner oblique, middle circular and outer longitudinal layers of the gastric tunica muscularis or due to presence of fibrous tissue within the gastric muscularis layer. The clinical significance of canine gastric muscularis UHS is uncertain.

Extrahepatic biliary atresia in a 4-week-old Pug

OBJECTIVE

To report diagnosis and surgical therapy of extrahepatic biliary atresia in a dog.

STUDY DESIGN

Clinical report.

ANIMAL

Dog (n = 1).

METHODS

A 4-week-old female intact Pug presented with acholic feces, lethargy, and poor weight gain. On the basis of the stool color and abdominal ultrasonography findings, extrahepatic biliary atresia was suspected. Intraoperatively, no major duodenal papilla was identified and cholecystoduodenostomy was performed.

RESULTS

One day postoperatively the stool color was considered normal. On ultrasonographic examinations up to 6 months after surgery, the gall bladder remained small and the stoma was functional. Serum biochemical profile after 10 months had a mild increase in alanine-aminotransferase (149 U/L; reference interval [RI], 0-85 U/L) whereas alkaline phosphatase and glutamate dehydrogenase were within normal limits. At 15 months, clinical examination was normal and blood ammonia concentration was within normal limits (43 µmol/L; RI: <100 µmol/L) but bile acid concentrations were still markedly elevated (fasting, 95 µmol/L [RI: <20 µmol/L] to postprandial, 127 µmol/L [RI: <35 µmol/L]).

CONCLUSIONS

Ultrasonography and stool color can be helpful noninvasive diagnostic evidence in extrahepatic biliary atresia. Surgical correction with cholecystoduodenostomy with a good clinical outcome is possible even in very young dogs. Long-term prognosis in dogs with extrahepatic biliary atresia is unknown.

A pilot study to assess the feasibility of transcutaneous glomerular filtration rate measurement using fluorescence-labelled sinistrin in dogs and cats

In dogs and cats an assessment of renal function is often needed, however, existing methods including urine and plasma clearances are invasive, cumbersome and time consuming. This pilot study evaluated the feasibility of a transcutaneous glomerular filtration rate (GFR) measurement in dogs and cats. Additionally the optimal dose and location for the transcutaneous measurement device were investigated. Renal elimination of fluorescein-isothiocyanate-labelled sinistrin (FITC-S) was measured transcutaneously for 4 hours. The procedures were performed in awake, freely moving animals using escalating doses of FITC-S (10 mg/kg, 30 mg/kg, 50 mg/kg) with a wash-out period of at least 24 h in between. Multiple devices were placed on each animal. The resulting FITC-S disappearance curves were visually assessed to determine the most suitable location and the appropriate dose to reach an adequate transcutaneous peak signal for kinetic analysis. In both species 30 mg/kg were adequate for kinetic calculation. The most suitable place for the device was the lateral thoracic wall in dogs and the ventral abdominal wall in cats, respectively. Transcutaneous FITC-S clearance was then repeated using the optimal dose and location and in parallel with an additional plasma sinistrin clearance. Plasma elimination half-lives [min] were 26, 31 and 35, and corresponding transcutaneous elimination half-lives [min] were 26, 34 and 55, respectively in the dogs. Plasma elimination half-lives [min] were 51, 60 and 61, and corresponding transcutaneous elimination half-lives [min] were 75, 96 and 83, respectively in the cats. In conclusion, transcutaneous FITC-S clearance is a feasible method for the assessment of GFR in awake dogs and cats. It is noninvasive, well tolerated and easy to perform even in a clinical setting with results being readily available. A dose of 30 mg/kg of FITC-S seems adequate for kinetic assessment. Further studies are now needed to establish reference values and evaluate transcutaneous renal clearance in various conditions.

Gustatory and olfactory function in patients with granulomatosis with polyangiitis (Wegener's)

OBJECTIVES

Recent findings suggest that autoimmune disorders predispose to a diminished capacity to taste and smell. This has been shown for patients with systemic lupus erythematosus as well as for patients with rheumatoid arthritis (RA). Granulomatosis with polyangiitis (GPA), with its particular manifestations in the upper respiratory tract, may therefore have an even higher impact on these senses. The aims of this study were to evaluate the gustatory and olfactory function in patients with GPA, to compare them to sex- and age-matched healthy controls, and to correlate these findings with their GPA disease severity.

METHOD

Patients with established GPA were analysed by standardized assessments for gustatory and olfactory functions and examined for disease activity, stage of disease, and treatment.

RESULTS

Forty-four GPA patients were tested for their chemosensory functions. Compared to age- and sex-matched healthy controls, GPA patients showed significantly decreased olfactory scores along with diminished scores for their gustatory functions. The diminished sense of smell in GPA patients correlated significantly with elevated C-reactive protein (CRP) values whereas the gustatory impairment correlated with the duration and extent of the disease.

CONCLUSIONS

Our results indicate that olfactory and gustatory functions are significantly decreased in GPA. As the olfactory function of these patients was comparable to patients with RA, chemosensory impairment may not simply be a consequence of the involvement of the upper respiratory tract, but rather a common complication of systemic autoimmune diseases.

Plasma and urine neutrophil gelatinase-associated lipocalin (NGAL) in dogs with acute kidney injury or chronic kidney disease

Background

Neutrophil gelatinase–associated lipocalin (NGAL) is a protein that is used in human medicine as a real‐time indicator of acute kidney injury (AKI).

Hypothesis

Dogs with AKI have significantly higher plasma NGAL concentration and urine NGAL‐to‐creatinine ratio (UNCR) compared with healthy dogs and dogs with chronic kidney disease (CKD).

Animals

18 healthy control dogs, 17 dogs with CKD, and 48 dogs with AKI.

Methods

Over a period of 1 year, all dogs with renal azotemia were prospectively included. Urine and plasma samples were collected during the first 24 hours after presentation or after development of renal azotemia. Plasma and urine NGAL concentrations were measured with a commercially available canine NGAL Elisa Kit (Bioporto® Diagnostic) and UNCR was calculated. A single‐injection plasma inulin clearance was performed in the healthy dogs.

Results

Median (range) NGAL plasma concentration in healthy dogs, dogs with CKD, and AKI were 10.7 ng/mL (2.5–21.2), 22.0 ng/mL (7.7–62.3), and 48.3 ng/mL (5.7–469.0), respectively. UNCR was 2 × 10⁻⁸ (0–46), 1,424 × 10⁻⁸ (385–18,347), and 2,366 × 10⁻⁸ (36–994,669), respectively. Dogs with renal azotemia had significantly higher NGAL concentrations and UNCR than did healthy dogs (P < .0001 for both). Plasma NGAL concentration was significantly higher in dogs with AKI compared with dogs with CKD (P = .027).

Conclusions and Clinical Importance

Plasma NGAL could be helpful to differentiate AKI from CKD in dogs with renal azotemia.

Induction of luciferase activity under the control of an hsp70 promoter using high-intensity focused ultrasound: combination of bioluminescence and MRI imaging in three different tumour models

The in vivo temporal changes of luciferase activity were investigated under the control of an hsp70 promoter in three tumour models after the application of different intensities of high-intensity focused ultrasound (HIFU). Three cell lines, SCCVII, NIH3T3 and M21 were stably transfected with a plasmid containing the hsp70 promoter and luciferase reporter gene, and tumours were subcutaneously initiated into mice. At a size of 1300 ± 234 mm(3), the tumours were exposed to five intensities of continuous HIFU (802-1401-2157-3067-4133 W/cm(2)) for 20 sec. Bioluminescence and MR imaging were performed to assess luciferase activity and signal intensity changes in the tissue. The MRI scan protocol was pre- and post-contrast T1-wt-SE, T2-wt-FSE, DCE-MRI, diffusion-wt STEAM sequence, T2 relaxation time determination obtained on a 1.5-T GE MRI scanner. The NIH3T3 tumours showed the highest luciferase activity of 328.1 ± 7.1 fold at 24 h at a HIFU intensity of 3067 W/cm(2), the M21 tumours of 3.2 ± 0.6 fold 8 hours and the SCCVII tumours 2.9 ± 0.9 fold 4 hours post-HIFU at 2157 W/cm(2). The greatest increase in T2 signal intensity and T2 relaxation time of 20.7 ± 3.4% was seen in the SCCVII tumours. The highest contrast medium uptake of 10.1 ± 1.1% was noted in the M21 tumours, and 14.8 ± 1.9% in the SCCVII tumours. In all tumours, a significant increase in the diffusion coefficient was seen with increased HIFU intensity, the highest of which was 40.3 ± 4.1% in the SCCVII tumours. The three tumour cell lines stably transfected with the hsp70/luciferase gene showed differential luciferase activity, which peaked at different times after the application of HIFU and was dependant on tumour type and HIFU energy deposition.

Gustatory and olfactory function in rheumatoid arthritis

OBJECTIVES

To evaluate the gustatory and olfactory functions of patients with rheumatoid arthritis (RA) compared to sex- and age-matched healthy subjects and to investigate a potential relationship between disease activity [using the 28-joint Disease Activity Score (DAS28)] and chemosensory capacity. Furthermore, to dissect possible impacts of standard anti-inflammatory medications on the gustatory and olfactory functions.

METHODS

Patients with established RA underwent standardized assessment of their gustatory and olfactory functions. The patients were also examined for their disease activity, had their specific blood-test results analysed, and were asked to answer a standardized questionnaire about their quality of life, the negative effects of their disease, and about comorbidities.

RESULTS

A total of 101 RA patients (75 women, 26 men, mean age: 57.9 ± 13.8 and 64.2 ± 10.9 years, respectively) were analysed. In relation to age- and sex-related subjects, both female and male RA patients had a significantly decreased taste score (p < 0.001) and also a significantly decreased olfactory score (p < 0.05), indicating that a substantial number of patients suffer from hypogeusia or hyposmia. This abnormality did not correlate with disease activity, the duration of the disease, disease-modifying anti-rheumatic drug (DMARD) or tumour necrosis factor (TNF) inhibitor use, and the loss of the chemosensory functions, together indicating that hypogeusia and hyposmia are frequent clinical manifestations in RA patients independent of the inflammatory activity of their disease.

CONCLUSION

The results indicate that there is a significant decrease in the olfactory and gustatory function in RA patients compared to those of healthy controls, which can seriously and substantially affect the quality of the patients' life.

[Loss of olfaction with aging: a frequent disorder receiving little attention]

Loss of olfaction in old age is a frequent problem, which occurs at the same frequency as diabetes or severe sensorineural hearing loss. Problems caused by loss of the sense of smell may include weight loss due to loss of appetite, intake of rotten foods, social isolation and depression. Until now the loss of olfactory function has received relatively little attention compared to diabetes or hearing loss. In this article we review the loss of the sense of smell with age. Possible therapies are discussed to improve the quality of life in older people.

Paclitaxel and carboplatin vs gemcitabine and vinorelbine in patients with adeno- or undifferentiated carcinoma of unknown primary: a randomised prospective phase II trial

Platinum/taxane combinations are widely used in patients with carcinoma of unknown primary (CUP), yielding response rates of 30% and median overall survival of 9-11 months in selected patients. Yet these combinations have not been subject to a randomised trial to overcome selection bias, a major problem in CUP. We randomised 92 patients to either paclitaxel/carboplatin (arm A) or the non-platinum non-taxane regimen gemcitabine/vinorelbine (arm B). The primary endpoint was rate of practicability as defined: application of >or=2 cycles of therapy (1) with a maximal delay of 1 week (2) and survival of >or=8 months (3). Practicability was shown in 52.4% (95% CI 36-68%) in arm A and in 42.2% (95% CI 28-58%) in arm B, respectively. The median overall survival, 1-year survival -rate and response rate of patients treated in arm A was 11.0 months, 38, and 23.8%, arm B 7.0 months, 29, and 20%. In conclusion, the paclitaxel/carboplatin regimen showed clinically meaningful activity in this randomised trial (Clinical trial registration number 219, 'Deutsches KrebsStudienRegister', German Cancer Society.)

[The sense of smell in daily life]

An intact olfactory system affects all areas of life including the creation of new life, partner selection, daily hygiene, food intake, and the perception of danger from gas and smoke. The olfactory system is most effective from adolescence to middle age. With advancing age the regeneration of olfactory receptor cells decreases, often resulting in an increasing loss of smell. Functional anosmia affects 5% of the general population and 10% of those over 65. Therefore, olfactory dysfunctions are not uncommon. The following provides an overview of the physiology of smell, olfactory testing, special olfactory dysfunctions as well as treatment and general recommendations.

[Correction of ear malformations with autologous rib cartilage]

INTRODUCTION

Ear malformations are mainly isolated deformations but exist also in combination with various syndromes. A visible malformation in cases of microtia is a problem for the entire family. Auricular reconstruction with autologous cartilage has been well established in the last decade. Optimization of the technique has led to improved and reliable results.

OPERATION AND RESULTS

Based on the experience of 120 cases we developed a concept that allows total ear reconstruction in two operative steps. In the first operation autologous rib cartilage is harvested and a natural framework is created following the template from the opposite ear. The ear remnant is transposed and the framework placed in a subcutaneous pocket on the mastoid plane. After a healing period of around 6 weeks the second operation reconstructs the auricular projection and the retroauricular fold.

CONCLUSION

Based on an individualized surgical treatment, auricular reconstruction with autologous rib cartilage are possible from the age of around 8 to the advanced period of life with reproducibly good results.

Comparison of multiple environmental factors for asthmatic children in public housing

Nine families of a public housing development in Boston were enrolled in a pilot asthma intervention program designed to gather dense environmental data and generate hypotheses about the relative importance of different contaminants and the viability of interventions. Despite formidable challenges working with this inner-city population, the project team succeeded in gaining active support for the project by forming a partnership with a community-based organization and by building positive relationships between the field team and the residents. Families were provided with physical interventions such as air filters, industrial cleaning and mattress covers to each apartment. Indoor temperature was high and relative humidity low during winter. Insulation of exposed steam pipes did not lower temperature. Cockroach, mouse and pet antigen levels were variable and frequently high in settled dust. Viable fungal spore levels were variable and high in some apartments. Dust-mite allergen levels were below the level of concern. Industrial cleaning led to transient reduction in mouse and cockroach antigen burden. Mattress and pillow covers lowered dust-mite antigen in bedrooms, but not living rooms. Nitrogen dioxide (NO2) levels exceeded ambient concentrations due to use of gas stoves and concentrations of particulate matter with aerodynamic diameter <2.5 microm (PM2.5) were above ambient levels because of smoking. Air filtering systems did not reduce PM levels. Several volatile organic compounds (VOCs) were above adverse risk concentrations. We hypothesize that our findings are consistent with a multifactorial model for exacerbation of asthma in this population and that no single problem dominates.

The coxBAC operon encodes a cytochrome c oxidase required for heterotrophic growth in the cyanobacterium Anabaena variabilis strain ATCC 29413

Three genes, coxB, coxA, and coxC, found in a clone from a gene library of the cyanobacterium Anabaena variabilis strain ATCC 29413, were identified by hybridization with an oligonucleotide specific for aa(3)-type cytochrome c oxidases. Deletion of these genes from the genome of A. variabilis strain ATCC 29413 FD yielded strain CSW1, which displayed no chemoheterotrophic growth and an impaired cytochrome c oxidase activity. Photoautotrophic growth of CSW1, however, was unchanged, even with dinitrogen as the nitrogen source. A higher cytochrome c oxidase activity was detected in membrane preparations from dinitrogen-grown CSW1 than from nitrate-grown CSW1, but comparable activities of respiratory oxygen uptake were found in the wild type and in CSW1. Our data indicate that the identified cox gene cluster is essential for fructose-dependent growth in the dark, but not for growth on dinitrogen, and that other terminal respiratory oxidases are expressed in this cyanobacterium. Transcription analysis showed that coxBAC constitutes an operon which is expressed from two transcriptional start points. The use of one of them was stimulated by fructose.

Environmental management of asthma at Massachusetts managed care organizations

Asthma management staff at eight Massachusetts managed care organizations (MCOs) were interviewed to learn the extent of inclusion of environmental prevention strategies in their asthma disease management policies. Six of the plans had formal asthma disease management programs, all reported to be based on the National Heart Lung and Blood Institute guidelines, but none followed these guidelines in their entirety. Three MCOs provided for home visits that included addressing environmental factors for severe asthmatics. Despite the limited role that MCOs appear to play in environmental prevention of asthma, the authors identify opportunities and encourage efforts to expand these programs.

The inflammatory action of CD40 ligand (CD154) expressed on activated human platelets is temporally limited by coexpressed CD40

Recently, we have demonstrated that human platelets carry preformed CD40 ligand (CD154) molecules, which rapidly appear on the platelet surface following stimulation by thrombin. Once on the surface, platelet CD154 induces an inflammatory reaction of CD40-bearing endothelial cells. This study shows that strong platelet agonists other than thrombin also lead to the expression of CD154 on the platelet surface. At the same time, several lines of evidence are presented that together indicate that thrombotic events in the vasculature are generally accompanied by activation of the inflammatory potential of platelet CD154. This study also reports the constitutive expression of CD40, the receptor for CD154, on platelets. The binding of CD154 to coexpressed CD40 in the platelet aggregate leads within minutes to hours to the cleavage of membrane-bound surface CD154 and the release of an 18-kd soluble form of the molecule. Soluble CD154 (sCD154), in contrast to transmembrane CD154, can no longer induce an inflammatory reaction of endothelial cells. These findings indicate that the interaction of platelet CD154 with CD40 on neighboring cells is temporally limited to prevent an uncontrolled inflammation at the site of thrombus formation. Thus, similar to the very tight regulation of the CD154-CD40 interaction in the immune system, an effective mechanism controls the inflammatory potential of platelet CD154 in the vascular system. (Blood. 2001;98:1047-1054)

Respiratory diseases in the first year of life in children born to HIV-1-infected women

Our objective was to describe the respiratory complications, clinical findings, and chest radiographic changes in the first year of life in infected and uninfected children born to HIV-1-infected women. We prospectively followed a cohort of 600 infants born to HIV-1-infected women from birth to 12 months in a multicenter study. Of these, 93 infants (15.5%) were HIV-1-infected, 463 were uninfected, and 44 were of unknown status prior to death or loss to follow-up. The cumulative incidence ( +/- SE) of an initial pneumonia episode at 12 months was 24.1 +/- 4.7% in HIV-1-infected children compared to 1.4 +/- 0.6% in HIV-1-uninfected children (P < 0.001). The rate of Pneumocystis carinii pneumonia (PCP) was 9.5 per 100 child-years. The HIV-1 RNA load was not higher in the group that developed pneumonia in the first year vs. those who did not. Children who developed lower respiratory tract infections or PCP had increased rates of decline of CD4 cell counts during the first 6 months of life. Lower maternal CD4 cell counts were associated with higher rates of pneumonia, and upper and lower respiratory tract infections. The rates of upper respiratory tract infection and bronchiolitis/reactive airway disease in infected children were not significantly different than in uninfected children. At 12 months, significantly more HIV-1-infected than uninfected children had tachypnea and chest radiographs with nodular and reticular densities. There was no relationship between cytomegalovirus infection in the first year of life and radiographic changes or occurrences of pneumonia. In conclusion, despite a low incidence of PCP, rates of pneumonia remain high in HIV-infected children in the first year of life. The incidence of pneumonia in uninfected infants born to HIV-1-infected mothers is low. Chest X-ray abnormalities and tachypnea suggest that subacute disease is present in infected infants. Further follow-up is warranted to determine its nature.

Forced expiratory flow in uninfected infants and children born to HIV-infected mothers

The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV (P(2)C(2) HIV) Study is a multicenter study examining pulmonary and cardiac outcomes in offspring of HIV-infected mothers. This portion of the P(2)C(2) study tests the hypothesis that infants exposed to, but uninfected by, maternal HIV have normal maximal expiratory flow at functional residual capacity (V'max,(FRC)). We obtained 500 measurements of V'max,(FRC) by rapid thoracic compression in 285 children ages 6-30 mo in five U.S. centers. The data were compared with those from a healthy cohort of children described elsewhere. V'max,(FRC) rose with height in a linear relationship. The slope of the regression line in the exposed infants did not differ statistically from the slope in the comparison group, but the intercept was about 20% lower (p < 0.001). Height and weight were comparable in the two cohorts, and the differences between intercepts persisted after adjusting for birth weight and gestational age. However, maternal HIV infection cannot be assumed to be the cause as the cohorts may have differed in other variables, such as socioeconomic status and frequency of maternal smoking and drug use. Also, measurements varied substantially within and between our five centers, probably in part because of different racial and ethnic distributions. In summary, maternal HIV infection probably has only a modest effect, if any, on maximal expiratory flow at functional residual capacity in uninfected infants.

Beliefs about diagnosing asthma in young children

OBJECTIVES

To determine what factors primary care pediatricians believe are important in establishing the initial diagnosis of childhood asthma and to identify variations in physicians' beliefs concerning this clinical decision.

STUDY DESIGN

Massachusetts American Academy of Pediatrics Fellows were surveyed about their beliefs concerning the importance of 20 clinical factors associated with establishing the initial diagnosis of asthma.

RESULTS

Most clinicians considered recurrent wheeze (96%), symptomatic improvement with a bronchodilator (90%), recurrent cough (89%), exclusion of alternative diagnoses (87%), and suggestive peak flow findings (82%) as important in diagnosing asthma. However, there was substantial heterogeneity among clinicians as to which combinations of factors they each considered relevant; for example, only 60% identified all 5 of the above factors to be necessary or important. Further, <50% identified presence of any of the 20 factors as necessary. Although national guidelines cite objective assessment of pulmonary function as essential, spirometry and peak expiratory flow testing were identified as necessary by only 8% and 10%, respectively. Two factors believed to contribute to establishing the asthma diagnosis contradicted the National Asthma Education and Prevention Program guidelines and expert opinion (age >2 years and absence of fever during episodes) and these beliefs were more likely held by those clinicians in practice for >5 years.

CONCLUSIONS

The majority of pediatricians believe several common clinical factors establish a diagnosis of childhood asthma, but disagree over what combinations of these factors are important. Some misconceptions persist despite wide dissemination of clinical practice guidelines. We believe that future asthma guidelines will need to organize diagnostic criteria in an easily understood format, like a decision tree, to facilitate early recognition of asthma in young children.

Identification of aquaporin 5 (AQP5) within the cochlea: cDNA cloning and in situ localization

Dysfunction of fluid and electrolyte homeostasis is considered to cause variety of inner ear disorders. One group of candidate proteins that may play a critical role in the inner ear fluid homeostasis is the aquaporins, a family of proteins whose members have well defined roles in fluid transport in variety of organs. This study reports the identification of AQP5, a member of the aquaporin family, within the rat inner ear and its in situ localization. AQP5 was initially identified within rat cochlear RNA via RT-PCR and sequence analysis of the amplified fragments. Immunoblot of cochlear homogenate yielded a predominant AQP5-immunoreactive band of M(r) 35 kDa. The anti-AQP5 immunoreactivity, indicating expression of the AQP5 polypeptide, was localized within the cochlea in situ to the cell types that form the lateral wall of the cochlear duct-the external sulcus (ES) cells and the cells of the spiral prominence. Expression of AQP5 was observed in the apical turn but not the basal turn of the cochlea; nor was it observed in the vestibular neuroepithelia or its supporting cells. The restricted expression of AQP5 to the apical turns of the cochlea suggests its potential role in low frequency hearing.

A telecommunications system to manage patients with chronic disease

The care of patients with chronic disease is a large and growing problem in the United States and other industrialized countries.' it is expensive, and the quality of care received by patients is often sub-optimal, resulting in poor health outcomes. We developed a totally automated computer-controlled telecommunications system, called TLC, that provides--frequent, close monitoring of patients with chronic disease and reports the results to the patients' physicians on a timely basis, so that they can intervene appropriately. TLC also monitors the patients' important self care activities, such as medication-taking, and provides education and counseling to improve the patients' performance of these activities. The system operates through regularly scheduled telephone conversations with patients' in their homes. An evaluation of a TLC chronic disease application for patients with hypertension demonstrated that use of the system was associated with significant improvement of the patients' adherence to their medication regimens and significantly improved blood pressure control. These results show that it is possible to design an information science-based health care delivery system that performs functions usually performed only by health care professionals, and suggests that information science will become an important means of delivering health care services in the next millennium.

An epidemic of burkholderia cepacia transmitted between patients with and without cystic fibrosis

Burkholderia cepacia is an important pathogen in cystic fibrosis (CF) and an infrequent cause of nosocomial infection in non-CF patients. This report describes a large hospital outbreak that appeared to involve both patient groups, a previously unrecognized phenomenon. Ribotype restriction fragment length polymorphism (RFLP) profiles and pulsed-field gel electrophoresis-resolved macrochromosomal RFLPs were analyzed, a ribotype-based phylogenic tree was constructed, and case-control and cohort studies were performed. A single dominant clone was found in both CF and non-CF groups. Phylogenic analysis suggests that it has evolved independently and that such highly transmissible strains can emerge rapidly and randomly. Acquisition risk in the CF patients was linked to hospitalization (odds ratio=5.47, P=.0158, confidence interval=1. 28-26.86) and was associated with significantly increased mortality rates. Infection control policies must now consider this threat of transmission between non-CF and CF patients.

Assembly of adeno-associated virus type 2 capsids in vitro

Capsid proteins VP1, VP2 and VP3 of adeno-associated virus type 2 (AAV-2) were separately expressed by recombinant baculoviruses, purified under denaturing conditions and renatured in the presence of 0.5 M arginine, followed by dialysis against buffers of physiological ionic strength. At a protein concentration of 0.05 mg/ml, the three capsid proteins predominantly formed monomers and, to a lesser extent, oligomers, as determined by sedimentation analysis. Oligomerization increased at higher protein concentrations. The capsid protein oligomers consisted of globular, non-capsid-like structures, as detected by electron microscopy. Addition of a HeLa cell extract significantly stimulated oligomerization of the capsid proteins, probably due to interactions with HeLa cell proteins. Characterization of structures sedimenting around 60S by immunoprecipitation and electron microscopy showed that, in addition to other aggregates, empty capsid-like structures were formed in vitro. The identity of these structures as empty AAV capsids was verified by immunoelectron microscopy. Analysis of capsid formation in HeLa cells by transfection of VP expression constructs allowing separate expression of VP1, VP2 and VP3 showed that they were able to form capsids, although with a reduced efficiency as compared to VP proteins expressed from the wt cap gene. This finding suggests that the mutations introduced to allow separate capsid protein expression reduced the efficiency of capsid assembly in vivo and might also explain the reduced recovery of empty capsids employing the in vitro assembly procedure.

The emergence of a highly transmissible lineage of cbl+ Pseudomonas (Burkholderia) cepacia causing CF centre epidemics in North America and Britain

The rapid increase in Pseudomonas (Burkholderia) cepacia infection in cystic fibrosis (CF) patients suggests epidemic transmission, but the degree of transmissibility remains controversial as conflicting conclusions have been drawn from studies at different CF centres. This report provides the first DNA sequence-based documentation of a divergent evolutionary lineage of P. cepacia associated with CF centre epidemics in North America (Toronto) and Europe (Edinburgh). The involved epidemic clone encoded and expressed novel cable (Cbl) pili that bind to CF mucin. The sequence of the cblA pilin subunit gene carried by the epidemic isolates proved to be invariant. Although it remains to be determined how many distinct, highly transmissible lineages exist, our results provide both a DNA sequence and chromosomal fingerprint that can be used to screen for one such particularly infectious, transatlantic clone.

Transmissibility of Pseudomonas cepacia infection in clinic patients and lung-transplant recipients with cystic fibrosis

BACKGROUND

In patients with cystic fibrosis, infection with Pseudomonas cepacia is associated with poor outcomes. However, the extent of person-to-person transmission and the source of P. cepacia infection after lung transplantation are not well defined. Using DNA-based typing systems, we sought to determine the genetic relatedness of P. cepacia infection at one cystic fibrosis center.

METHODS

We analyzed 65 P. cepacia isolates gathered over a period of eight years at a single cystic fibrosis center from 17 clinic patients and from 5 patients who underwent double-lung transplantation. The isolates were analyzed by ribotyping and chromosomal fingerprinting based on pulsed-field gel electrophoresis.

RESULTS

Analyses of serial isolates revealed that each clinic patient and transplant recipient harbored a different P. cepacia clone that was persistent. In the transplant recipients, the preoperative and postoperative isolates were identical. In the two patients with disseminated infection after lung transplantation, isolates from multiple sites were identical and indicated clonal expansion of the previous respiratory P. cepacia strain. Pulsed-field gel electrophoresis proved both more discriminative and more practical than ribotyping as a means of defining the genetic relatedness of the P. cepacia isolates.

CONCLUSIONS

Our serial analyses in patients with cystic fibrosis at one center found distinct strains of P. cepacia persistently infecting each patient and no evidence of person-to-person transmission of this organism. P. cepacia infection after lung transplantation was due to the persistence of the strain present before transplantation.

Conservation of the gene for outer membrane protein OprF in the family Pseudomonadaceae: sequence of the Pseudomonas syringae oprF gene

The conservation of the oprF gene for the major outer membrane protein OprF was determined by restriction mapping and Southern blot hybridization with the Pseudomonas aeruginosa oprF gene as a probe. The restriction map was highly conserved among 16 of the 17 serotype strains and 42 clinical isolates of P. aeruginosa. Only the serotype 12 isolate and one clinical isolate showed small differences in restriction pattern. Southern probing of PstI chromosomal digests of 14 species from the family Pseudomonadaceae revealed that only the nine members of rRNA homology group I hybridized with the oprF gene. To reveal the actual extent of homology, the oprF gene and its product were characterized in Pseudomonas syringae. Nine strains of P. syringae from seven different pathovars hybridized with the P. aeruginosa gene to produce five different but related restriction maps. All produced an OprF protein in their outer membranes with the same apparent molecular weight as that of P.aeruginosa OprF. In each case the protein reacted with monoclonal antibody MA4-10 and was similarly heat and 2-mercaptoethanol modifiable. The purified OprF protein of the type strain P. syringae pv. syringae ATCC 19310 reconstituted small channels in lipid bilayer membranes. The oprF gene from this latter strain was cloned and sequenced. Despite the low level of DNA hybridization between P. aeruginosa and P. syringae DNA, the OprF gene was highly conserved between the species with 72% DNA sequence identity and 68% amino acid sequence identity overall. The carboxy terminus-encoding region of P. syringae oprF showed 85 and 33% identity, respectively, with the same regions of the P. aeruginosa oprF and Escherichia coli ompA genes.