Colonial morphology of Burkholderia cepacia complex genomovar III: implications in exopolysaccharide production,pilus expression,and persistence in the mouse

The purpose of this study was to determine the role of colonial morphology of Burkholderia cepacia complex (BCC) organisms in pathogenicity in a mouse model of pulmonary infection. BCC strain C1394 was rapidly cleared by leukopenic mice after intranasal challenge, whereas a spontaneous variant (C1394mp2) that was indistinguishable from the parent strain by genetic typing persisted in the lungs and differed in colonial morphology. The parent strain had a matte colonial phenotype, made scant exopolysaccharide (EPS), and was lightly piliated. The variant had a shiny phenotype, produced abundant EPS, and was heavily piliated. Matte to shiny colonial transformation was induced by growth at 42 degrees C. Colonial morphology in the BCC strain variant was associated with persistence after pulmonary challenge and appeared to be correlated with the elaboration of putative virulence determinants.     

Interaction of hepatitis B surface antigen (Australia antigen) with membrane vesicles of Pseudomonas aeruginosa.

A lysogenic strain of Pseudomonas aeruginosa was cultured from the dialysis fluid of a patient on chronic hemodialysis treatment whose blood contained hepatitis B surface antigen (HB8Ag). When this bacterium was incubated for 4 to 7 days with serum containing HB8Ag or with purified HB8Ag, a loss of the HB8Ag-specific immunological reactivity was observed. Bacteriophages can be induced from the isolated P. aeruginosa with mitomycin C; the phages, after purification on CsCl gradients, also lyse P. aeruginosa strain 25102 (ATCC). Subsequent to gradient centrifugation of the lysate, a fraction was found with a density around 1.40 g/ml that inactivated HB8Ag after a 4-h incubation at 37 C as determined by counterelectrophoresis and hemagglutination inhibition. The activity was not found in appreciable amounts in other gradient fractions. The electron microscope shows that the active fraction contains envelope vesicles of 45 to 60 nm in diameter. In spite of their loss in HB8Ag activity, the HB8Ag particles (22nm) appeared morphologically intact. These findings suggest that an enzyme(s) is present in the vesicle fraction which inactivates antigenic determinants on HB8Ag particles. Thus, the presence of these bacteria in environments such as feces, dialysis tanks, and contaminated drinking water may prevent the detection of HB8Ag.     

Cytotoxic T cell responses to haptenated cells III. Isolation and specificity analysis of continuously growing clones

Various procedures were used to derive continuously growing cytotoxic T lymphocyte (CTL) clones from a primary culture containing responder cells from immunized mice and 3-(p-sulfophenyldiazo)-4-hydroxylphenyl acetic acid (SP)-or fluorescein isothiocyanate (FL)-coupled stimulator cells. It seems likely that CTL have to undergo some change, possibly genetic, to be able to grow continuously in T cell growth factor conditioned medium in the absence of any stimulator or filler cells. The most convenient and reliable procedure to generate CTL clones with different specificities was to establish from several aliquots of a primary culture cell populations continuously growing in medium conditioned with T cell growth factor(s). Clones with different specificities segregated in the different populations. SP-and FL-specific CTL clones restricted to H-2K^k, and H-2D^d and two FL-specific CTL clones with no apparent H-2 restriction are described.     

Comparison of the QUANTIPLEX HIV-1 RNA 2.0 Assay with the AMPLICOR HIV-1 MONITOR 1.0 Assay for Quantitation of Levels of Human Immunodeficiency Virus Type 1 RNA in Plasma of Patients Receiving Stavudine-Didanosine Combination Therapy

We compared the QUANTIPLEX HIV-1 RNA 2.0 assay with the AMPLICOR HIV-1 MONITOR 1.0 assay for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma in the Stadi trail, which evaluated a stavudine plus didanosine combination therapy in 52 patients. HIV-1 RNA baseline values measured with AMPLICOR HIV-1 MONITOR 1.0 were significantly higher than those measured with QUANTIPLEX HIV-1 RNA 2.0, and decreases in HIV-1 RNA levels from baseline were also found to be significantly higher when measured with the AMPLICOR HIV-1 MONITOR 1.0 assay. The frequency of HIV-1 RNA levels below the lower limit of quantitation was significantly higher with QUANTIPLEX HIV-1 RNA 2.0 than with AMPLICOR HIV-1 MONITOR 1.0. Reanalysis of these results by an ultrasensitive procedure of AMPLICOR HIV-1 MONITOR 1.0 or by a modified version of the test that included additional primers adapted for non-B HIV-1 clades yielded greater differences between the QUANTIPLEX HIV-1 RNA 2.0 assay and the AMPLICOR HIV-1 MONITOR 1.0 assay. Our results indicate that a valid comparison of the virological efficacies obtained with different antiretroviral drug regimens requires the use of the same viral load quantitation procedure; further standardization between the different HIV-1 RNA quantitation kits is therefore needed.     

p53 expression in Barrett's oesophagus,dysplasia, and adenocarcinoma using antibody DO-7

Barrett's oesophagus has a well-recognized association with oesophageal adenocarcinoma, with phenotypic progression through dysplasia to malignancy. The nuclear phosphoprotein p53 is a putative tumour suppressor with mutations resulting in both loss of negative growth regulatory function and possible gain of oncogene function. Many mutant forms have a prolonged half-life and are demonstrable with immunohistochemical techniques. We examined 62 endoscopic oesophageal biopsies and 36 oesophageal resections for p53 overexpression using the monoclonal antibody DO-7 on paraffin-embedded tissue. The series included 40 cases of Barrett's metaplasia, 13 cases of dysplasia, and 81 cases of adenocarcinoma. None of the cases of metaplasia was p53-positive, compared with 4/13 cases of dysplasia and 52/81 cases of adenocarcinoma. There was no association between the degree of dysplasia and p53 expression, although a trend emerged of increasing p53 expression with higher tumour grade. We conclude that p53 overexpression is frequent in oesophageal adenocarcinoma and may be related to tumour grade. p53 overexpression is not restricted to neoplastic lesions and mutation of this tumour suppressor may occur early in the malignant progression of Barrett's oesophagus.     

The proximal border of the human respiratory unit,as shown by scanning and transmission electron microscopy and light microscopical cytochemistry

The muscles of the pectoral girdle in domestic animals attach the forelimbs to the trunk and function as the suspensory apparatus. In the present study the composition of the pectoral girdle musculature of sheep by myofiber types was examined. Myofibers showing a strong reaction for alkali-stable myosin ATPase were classified into fast-twitch/glycolytic (FG) myofibers with a weak activity for NADH tetrazolium reductase (NADH-TR) and fast-twitch/oxidative/glycolytic (FOG) myofibers with a moderate and strong NADH-TR activity. Myofibers showing a weak reaction for alkali-stable myosin ATPase and a strong activity for NADH-TR were classified as slow-twitch/oxidative (SO) myofibers. The SO myofibers that showed a granular and striped pattern of diformazan deposits in NADH-TR activity were classified as SO-1 myofibers, whereas the SO myofibers characterized by a reticular pattern of diformazan deposits were classified as SO-2 myofibers. The trapezius, rhomboideus cervicis, and pectoralis descendens muscles situated superficially in the cranial regions of the back and chest had about 50% SO (SO-1 plus SO-2) myofibers. The deeply situated serratus ventralis cervicis and thoracis muscles had 37.5% SO myofibers. These five muscles included more SO-2 myofibers with large diameters than did all other muscles, and had about 50% and more cross-sectional area of SO myofibers. The other muscles had less than 32% SO myofibers and fewer SO-2 myofibers. The FOG and FG myofibers accounted for 50% or less in the muscles examined. Many muscles of the pectoral girdle had many fast-twitch (FOG plus FG) myofibers; they seem to meet locomotory requirements. In the pectoral girdle musculature, the SO myofibers were not necessarily distributed more in the deep regions than in the superficial regions. The distribution of SO myofibers appears to meet postural requirements for stabilizing the shoulder and brachium and for supporting the trunk.     

A monoclonal antibody (100C5) to the Lyt-2− T cell population expanding in MRL/Mp-lpr/lpr mice detects a surface antigen normally expressed on Lyt-2+ cells and B cells

MRL/Mp-lpr/lpr (MRL-lpr) mice develop a generalized lymphadenopathy reflecting the expansion of a Lyt-2^? T cell population. The present report describes the pattern of reactivity of a xenogeneic monoclonal antibody (mAb 100C5) directed against this T cell population. By single- and two-color flow cytofluorometry analysis this mAb was found to stain brightly 80–90% of T cells in enlarged MRL-lpr lymph nodes. In contrast lymph node T cells from congenic MRL-MP-+/+ (MRL-+) mice were either unstained (70%) or weakly stained (30%), these latter cells being mostly Lyt-2⁺. Unexpectedly, all lymph node B cells from MRL-+ or MRL-lpr mice were as strongly 100C5⁺ as MRL-lpr T cells. Similar observations were made in C57BL/6-lpr/lpr and C57BL/6-+/+ mice. Molecular weight determination suggested that the 100C5 mAb binds to the same molecule (M_r = 220000) on MRL-lpr T cells and normal B cells.     

Theophylline and fibrocystic breast disease

After literature reports linking fibrocystic breast disease (FBD) to methylxanthine ingestion, a pilot study was undertaken to investigate the possible contribution of theophylline to this effect. The major goal of this project was to measure the effect of theophylline therapy on FBD in asthmatic women. All women attending an allergy clinic or an obstetrics/gynecology clinic over a 9-month period were examined to clinically assess FBD and were asked to complete a detailed questionnaire covering health history, other risk factors, and drug and dietary methylxanthines. The sample included 62 asthmatic women, 66 allergic but not asthmatic women, and 72 nonallergic and nonasthmatic women. By use of the FBD clinical taxonomy with its 19-point scale going from 0 to 18 that was developed for this study, the three groups did not differ significantly in terms of mean severity of FBD. On analyzing the effect of each of the methylxanthines on FBD severity, there is clear evidence that total methylxanthines was a contributing factor in FBD severity with or without adjustment for relevant variables, such as age, menopause, pregnancies, and groups. Theophylline was significant only when adjustments were made for age, pregnancy, and menopause in contrast to caffeine that was only significant with no adjustments.     

Coping strategies,hostility, and depressive symptoms: A path model

Previous studies of coping, hostility, and depressive symptoms have highlighted the significant relations between all possible pairs of these 3 variables. To more completely explore the nature of depressive symptoms, we link them all together in this study by testing a coping→hostility→depressive symptoms path model. One hundred forty participants completed psychological questionnaires measuring coping strategies, hostility, and depressive symptoms. While controlling age and social class as covariates, SPSS stepwise regression analyses were used to examine relations among these 3 constructs. Results suggest that coping has a direct relation with depressive symptoms as well as an indirect relation mediated by hostility. Passive coping may lead to increased hostility, resulting in depressive symptoms. Active coping may have the opposite effect. These findings suggest that the inclusion of measures of both coping strategies and hostility yields a more thorough understanding of concomitants of depressive symptoms. From a clinical perspective, knowing what coping strategies a person uses and how much anger they experience and express may be useful in guiding the management of depressive symptoms.     

Blood pressure in adults with short stature skeletal dysplasias

Hypertension, compounded by obesity, contributes to cardiovascular disease and mortality. Data describing hypertension prevalence in adults with short stature skeletal dysplasias are lacking, perhaps due to poor fit of typical adult blood pressure cuffs on rhizomelic or contracted upper extremities. Through health screening research, blood pressure was measured in short stature adults attending support group meetings and skeletal dysplasia clinics. Blood pressure was measured with a commercially available, narrower adult cuff on the upper and/or lower segment of the arm. Height, weight, age, gender, diagnosis, exercise, and medications were collected. Subjects were classified as normotensive, prehypertensive, or hypertensive for group analysis; no individual clinical diagnoses were made. In 403 short stature adults, 42% were hypertensive (systolic >140, diastolic >90 OR taking antihypertensive medications). For every BMI unit and 1 kg weight increase in males, there was a 9% and an 8% increase, respectively, in the odds of hypertension versus normotension. In females, the increase was 10% and 6%, respectively. In those with achondroplasia, the most common short stature dysplasia, males (n = 106) had 10% greater odds of hypertension versus normotension for every BMI unit and kilogram increase. In females with achondroplasia (n = 128), the odds of hypertension versus normotension was 8% greater for each BMI unit and 7% for each additional kilogram. These data suggest a high population prevalence of hypertension among short stature adults. Blood pressure must be monitored as part of routine medical care, and measuring at the forearm may be the only viable clinical option in rhizomelic short stature adults with elbow contractures.