Towards estimating the carbon footprint of external beam radiotherapy

PURPOSE

The National Health Service (NHS) in the United Kingdom (UK) is aiming to be carbon net zero by 2040 to help limit the dangerous effects of climate change. Radiotherapy contributes to this with potential sources quantified here.

METHOD

Activity data for 42 patients from within the breast IMRT and prostate VMAT pathways were collected. Data for 20 prostate patients was also collected from 3 other centres to enable cross centre comparison. A process-based, bottom-up approach was used to calculate the carbon footprint. Additionally, patients were split into pre-COVID and COVID groups to assess the impact of protocol changes due to the pandemic.

RESULTS

The calculated carbon footprint for prostate and breast pre-COVID were 148 kgCO2e and 101 kgCO2e respectively, and 226 kgCO2e and 75 kgCO2e respectively during COVID. The energy usage by the linac during treatment for a total course of radiotherapy for prostate treatments was 2-3 kWh and about 1 kWh for breast treatments. Patient travel made up the largest proportion (70-80%) of the calculated carbon footprint, with linac idle power second with ∼ 10% and PPE and SF6 leakage were both between 2 and 4%.

CONCLUSION

These initial findings highlight that the biggest contributor to the external beam radiotherapy carbon footprint was patient travel, which may motivate increased used of hypofractionation. Many assumptions and boundaries have been set on the data gathered, which limit the wider application of these results. However, they provide a useful foundation for future more comprehensive life cycle assessments.

David (Dave) Charles Fork (1929-2020): a gentle human being, a great experimenter, and a passionate researcher

We provide here an overview of the remarkable life and outstanding research of David (Dave) Charles Fork (March 4, 1929-December 13, 2021) in oxygenic photosynthesis. In the words of the late Jack Edgar Myers, he was a top 'photosynthetiker'. His research dealt with novel findings on light absorption, excitation energy distribution, and redistribution among the two photosystems, electron transfer, and their relation to dynamic membrane change as affected by environmental changes, especially temperature. David was an attentive listener and a creative designer of experiments and instruments, and he was also great fun to work with. He is remembered here by his family, coworkers, and friends from around the world including Australia, France, Germany, Japan, Sweden, Israel, and USA.

Characteristics of heterosexually-acquired compared to homosexually-acquired HIV and implications for clinical practice: results from the Australian HIV Observational Database

Heterosexuals living with HIV report feeling additional HIV stigma compared to homosexual men, which may affect clinical outcomes. Yet, beyond routinely collected surveillance data, little is known about the characteristics of individuals who acquire HIV heterosexually and clinical outcomes by mode of sexual acquisition have not been directly compared. Using data from the Australian HIV Observational Database, we compared clinical characteristics of those with heterosexually-acquired (Het-HIV) to homosexually-acquired HIV (Hom-HIV) to investigate any differences and their implications for clinical management. 513 Het-HIV and 1467 Hom-HIV patients were included and contributed 3,127 and 9,457 person-years of follow-up, respectively. Compared with Hom-HIV, Het-HIV were more often born outside Australia (62.5% vs 39.9%, p<0.001), less likely to have Hepatitis C (4.8% vs 7.8%, p=0.029) and had lower median CD4 counts at diagnosis (292 vs 450 cells/µL, p<0.001) and cART initiation (270 vs 340 cells/µL, p<0.001). Despite these lower CD4 counts, there were no significant differences between groups for time to the major clinical endpoints of cART initiation, viral suppression, virological failure or all-cause mortality. Het-HIV had a lower risk of loss-to-follow-up than Hom-HIV (aHR 0.78; 95% CI 0.64-0.95). Further studies examining factors associated with, and interventions to inform retention in care are required.

Hyphal network whole field imaging allows for accurate estimation of anastomosis rates and branching dynamics of the filamentous fungus Podospora anserina

The success of filamentous fungi in colonizing most natural environments can be largely attributed to their ability to form an expanding interconnected network, the mycelium, or thallus, constituted by a collection of hyphal apexes in motion producing hyphae and subject to branching and fusion. In this work, we characterize the hyphal network expansion and the structure of the fungus Podospora anserina under controlled culture conditions. To this end, temporal series of pictures of the network dynamics are produced, starting from germinating ascospores and ending when the network reaches a few centimeters width, with a typical image resolution of several micrometers. The completely automated image reconstruction steps allow an easy post-processing and a quantitative analysis of the dynamics. The main features of the evolution of the hyphal network, such as the total length L of the mycelium, the number of “nodes” (or crossing points) N and the number of apexes A, can then be precisely quantified. Beyond these main features, the determination of the distribution of the intra-thallus surfaces (S_i) and the statistical analysis of some local measures of N, A and L give new insights on the dynamics of expanding fungal networks. Based on these results, we now aim at developing robust and versatile discrete/continuous mathematical models to further understand the key mechanisms driving the development of the fungus thallus.

Sildenafil, pulmonary hypertension and bronchopulmonary dysplasia

Pulmonary hypertension (PH) secondary to bronchopulmonary dysplasia (BPD) in infants remains a serious concern and continues to cause significant morbidity despite improvements in both quality of life and survival for patients. One of the potential agents that might help is sildenafil citrate, a phosphodiesterase-V inhibitor used a first line therapy for idiopathic PH. However, only limited evidence exists for its use as either monotherapy or part of a combination approach towards the management of PH in BPD. The evidence and current knowledge is presented for sildenafil alone and in combination with other disease modifying agents to treat PH in the presence of BPD. We have previously suggested that sildenafil appears to be safe and possibly effective in this condition. We present the evidence that if continued until PH resolution, there might be reduced mortality in this debilitating disease.

Energy expenditure on recreational visits to different natural environments

Physical inactivity poses a significant challenge to physical and mental health. Environmental approaches to tackle physical inactivity have identified natural environments as potentially important public health resources. Despite this, little is known about characteristics of the activity involved when individuals visit different types of natural environment. Using Natural England's Monitor of Engagement with the Natural Environment Survey, we examined 71,603 English respondents' recreational visits to natural environments in the past week. Specifically, we examined the intensity of the activities they undertook on the visits (METs), the duration of their visit, and the associated total energy expenditure (MET minutes). Visits to countryside and urban greenspace environments were associated with more intense activities than visits to coastal environments. However, visits to coastal environments were associated with the most energy expenditure overall due to their relatively long duration. Results differed by the urbanity or rurality of the respondent's residence and also how far respondents travelled to their destination. Knowledge of what types of natural environment afford the highest volumes and intensities of physical activity could inform landscape architecture and exercise prescriptions. Isolating activity-supporting characteristics of natural environments that can be translated into urban design is important in providing physical activity opportunities for those less able to access expansive environments.

Abstract P6-08-06: Sexual function, sexual activity and quality of life in women with breast cancer

Background: Breast cancer (BC) is generally assumed to have an impact on sexual function and activity. Although there are several studies addressing the issue, case control studies are currently limited.

Methods: We performed a cross-sectional investigation of sexual function and activity utilizing the sexual activity questionnaire, the female sexual function index, and parts of the EORTC QLQ C30. Patients with breast cancer (BC) were compared with a control group (C) of non-cancer patients. Inclusion of BC was only allowed if treatment was completed ≥ 12 months previously and patients were disease-free. This study was approved by the ethical committee of the Landesärztekammer Hessen. All consecutive patients with breast cancer who were treated at our hospital were prospectively documented in a clinical tumor registry since 2001. All patients’ records are updated annually. The control sample without any oncologic disease of 392 age-matched females was recruited in the Department of Prosthodontics, University Hospital Mainz.

Results: Between December 2009 and May 2010 the questionnaires were sent out to 790 women (398 x BC and 392 x C), 21.6% of which responded. Response rates in both groups were equivalent (84 patients with BC [21.2%] and 87 control subjects [22.2%]). Median age was 57 years (C) and 62 years (BC), respectively (p = 0.005). 51.5% (C) and 60% (BC) were not sexually active, mainly owing to lack of a partner (39%) or lack of interest (21%) in controls and lack of interest (48%, p&lt;0.05), self-reported physical problems (34%, p&lt;0.05), and physical problems of the partner (22%, p&lt;0.05) in breast cancer patients. There were significant differences between both groups in the SAQ discomfort score (p&lt;0.05). We did not observe significant differences in quality of life or other scores regarding sexuality.

Conclusions: About half of the women in both groups were not sexually active. However, reasons for non-activity differ. Quality of sexuality tends to be impaired in BC patients, but this seems not to influence quality of life. A shift of priority caused by substantial anxiety regarding cancer specific survival might explain our findings.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-08-06.

Sorption of antibiotic sulfamethoxazole varies with biochars produced at different temperatures

Sorption of sulfonamides on biochars is poorly understood, thus sulfamethoxazole (SMX) sorption on biochars produced at 300-600 °C was determined as a function of pH and SMX concentration, as well as the inorganic fractions in the biochars. Neutral SMX molecules (SMX(0)) were dominant for sorption at pH 1.0-6.0. Above pH 7.0, although biochars surfaces were negatively-charged, anionic SMX species sorption increased with pH and is regulated via charge-assisted H-bonds. SMX(0) sorption at pH 5.0 was nonlinear and adsorption-dominant for all the biochars via hydrophobic interaction, π-π electron donor-acceptor interaction and pore-filling. The removal of inorganic fraction reduced SMX sorption by low-temperature biochars (e.g., 300 °C), but enhanced the sorption by high-temperature biochars (e.g., 600 °C) due to the temperature-dependent inorganic fractions in the biochars. These observations are useful for producing designer biochars as engineered sorbents to reduce the bioavailability of antibiotics and/or predict the fate of sulfonamides in biochar-amended soils.

Avascular necrosis in HIV patients: a case-control study

This study investigates the association of avascular necrosis (AVN) in human immunodeficiency virus (HIV)-positive individuals with possible risk factors, including antiretroviral therapy. Clinic records of all AVN cases diagnosed up to July 2009 in HIV-positive patients attending North Middlesex Hospital, London, UK were retrospectively reviewed. For each case, one control was randomly selected, matched for gender, age, nadir CD4 count and date of HIV diagnosis. Of 15 symptomatic AVN cases identified, eight were in women. Univariate analysis demonstrated significant associations between AVN and a history of systemic steroid use (p = 0.004) and cumulative exposure to protease inhibitor (p = 0.03). Physicians should be aware of the risk of AVN with steroid use, the importance of early diagnosis and avoidance of other risk factors in order to prevent further joint involvement if possible.

Characterization and influence of biochars on nitrous oxide emission from agricultural soil

Extensive use of biochar to mitigate N(2)O emission is limited by the lack of understanding on the exact mechanisms altering N(2)O emissions from biochar-amended soils. Biochars produced from giant reed were characterized and used to investigate their influence on N(2)O emission. Responses of N(2)O emission varied with pyrolysis temperature, and the reduction order of N(2)O emission by biochar (BC) was: BC200 ≈ BC600 > BC500 ≈ BC300 ≈ BC350 > BC400. The reduced emission was attributed to enhanced N immobilization and decreased denitrification in the biochar-amended soils. The remaining polycyclic aromatic hydrocarbons (PAHs) in low-temperature biochars (300-400 °C) played a major role in reducing N(2)O emission, but not for high-temperature biochars (500-600 °C). Removal of phenolic compounds from low-temperature (200-400 °C) biochars resulted in a surprising reduction of N(2)O emission, but the mechanism is still unknown. Overall, adding giant reed biochars could reduce N(2)O evolution from agricultural soil, thus possibly mitigating global warming.

Characteristics and nutrient values of biochars produced from giant reed at different temperatures

To investigate the effect of pyrolysis temperature on properties and nutrient values, biochars were produced from giant reed (Arundo donax L.) at 300-600°C and their properties such as elemental and mineral compositions, release of N, P and K, and adsorption of N and P were determined. With increasing temperatures, more N was lost and residual N was transformed into heterocyclic-N, whereas no P and K losses were observed. P was transformed to less soluble minerals, resulting in a reduction in available-P in high-temperature biochars. A pH of⩽5 favored release of NH(4)(+), PO(4)(3-) and K(+) into water. Low-temperature biochars (⩽ 400°C) showed appreciable NH(4)(+) adsorption (2102mgkg(-1)). These results indicate that low-temperatures may be optimal for producing biochar from giant reed to improve the nutrient availability.

Assessment of herbicide sorption by biochars and organic matter associated with soil and sediment

Sorption of two herbicides, fluridone (FLUN) and norflurazon (NORO), by two types of biochars, whole sediment, and various soil/sediment organic matter (OM) fractions including nonhydrolyzable carbon (NHC), black carbon (BC) and humic acid (HA) was examined. The single-point organic carbon (OC)-normalized distribution coefficients (K(OC)) of FLUN and NORO at low solution concentration (C(e)=0.01S(W), solubility) for HA, NHC, and BC were about 3, 14, and 24 times and 3, 16, and 36 times larger than their bulk sediments, respectively, indicating the importance of different OM fractions in herbicide sorption. This study revealed that aliphatic moieties of the hydrothermal biochars and aromatic moieties of NHC samples, respectively, were possibly responsible for herbicide sorption. The hydrothermal biochar and condensed OM (i.e., NHC and BC) showed relatively high or similar herbicide sorption efficiency compared to the thermal biochar, suggesting that the hydrothermal biochar may serve as an amendment for minimizing off-site herbicide movement.

Continuous electrical stimulation as a helpful adjunct during intraoperative facial nerve monitoring

Routine intraoperative monitoring of facial function has been used since 1985. An adaptor has been developed for continuous stimulation (SACS) to be used with the new WR-S8, Monitor/Stimulation The SACS allows the microsurgical instruments and air drills to be electrified and to function as probe tips during surgical dissection. The new WR-S8 Monitor/Stimulator has an ultrasensitive strain gauge that detects facial movement before it is palpable. The remote probe allows an assistant to adjust the current easily. The routine use of facial nerve monitoring with SACS has decreased surgical time, has helped prevent iatrogenic injuries, and has improved our ability to save the facial nerve during otologic and neuro-otologic surgery.

Falciparum malaria as a cause of fever in adult travellers returning to the United Kingdom: observational study of risk by geographical area

BACKGROUND

The probability that a returned traveller with a history of fever has malaria is likely to vary by geographical area, but this has not been quantified in travellers.

AIM

To collect data on prevalence of malaria in outpatients returning with a fever or history of fever from malaria-endemic countries, at the point of presentation for a malaria test.

DESIGN

Observational retrospective study. Consecutive patients presenting to an unselected 'walk-in' clinic for returned travellers.

RESULTS

Of 2867 patients meeting inclusion criteria, 337 (11.8%) had malaria, 89.5% originating in sub-Saharan Africa. Of travellers returning from sub-Saharan Africa excluding South Africa with fever/history of fever, 291/1497 had malaria (19.4%, 95% CI 17-21%). A high proportion was visiting friends and relatives. In those from other areas the proportions were: 16/707 (2.3%, 95% CI 1.5-3.8) from Indian subcontinent/Southeast Asia; 2/143 (1.4%) from Southern America; 4/129 (3.1%) from South Africa; 1/44 (2.3%) from North Africa; and 8/41 (19.5%) from Oceania. Compared to other malaria-endemic regions, African travel gave an adjusted odds ratio of 7.8 (95% CI 5.4-11.2, P < 0.0001). Only 45.1% of malaria cases had a fever (> or =37.5 degrees C) at the time of presentation. Only 3% of all diagnoses of malaria had no history of fever. In 28% of cases parasite count increased in the initial 24 h of antimalarial treatment.

CONCLUSION

The likelihood that a patient with fever returning from Africa has malaria is high (around 1 in 5), and is significantly lower from other areas. Absence of fever at presentation does not exclude malaria.

Biologic response to subcutaneous and intranasal therapy with desmopressin in a large Amish kindred with Type 2M von Willebrand disease

The aim of this study was to characterize the adequacy and longevity of biological response to desmopressin (DDAVP) in a large Amish kindred of Type 2M von Willebrand disease (VWD) possessing C-to-T transition at nucleotide 4120 in exon 28 of A1 domain of von Willebrand factor (VWF) gene. Response to both intranasal (Stimate) and subcutaneous DDAVP administration was assessed. Rise in ristocetin cofactor activity (VWF:RCo) > or = 40% at 90-min post-Stimate and 1-2 h after subcutaneous DDAVP was defined as initial response; response longevity was assessed only after subcutaneous dosing by measuring VWF:RCo levels at time-points 1, 2, 4 and 6 h. Eleven patients (five males, six females; age range: 20-56 years) participated in intranasal and 9/11 (four males, five females) in subcutaneous testing. Baseline haemostatic profiles included: VWF:RCo < 15%, VWF:Ag < 40% and normal VWF multimers. Initial response was comparable by both intranasal (6/11; 54.5%) and subcutaneous (4/9; 44%) routes; sustained response (VWF:RCo > 40% for 2 h) was observed in only one in nine (11%) patients tested. Median VWF:RCo peak levels after intranasal (40%) and subcutaneous (39%) routes were equivalent. Peak VWF:Ag levels were significantly higher after subcutaneous than intranasal DDAVP (94% vs. 54%; P = 0.03). Area under the curve for VWF:RCo was significantly decreased (170 microg h mL(-1)) compared with VWF:Ag (471 microg h mL(-1)) and FVIII:C (624.60 microg h mL(-1)). This study suggests that in this population: (i) intra-individual DDAVP response is consistent with subcutaneous and intranasal administration; and (ii) extending DDAVP challenge test up to at least 6 h is required to characterize adequacy and longevity of biologic response prior to using DDAVP as a sole haemostatic intervention.

Chronic Hepatitis C: Viral Clearance Several Months after Discontinuation of Therapy in Two Non-responders

When hepatitis C virus (HCV) infection becomes chronic, spontaneous viral eradication is a rare event. We report two patients with chronic hepatitis C, non-responders to standard interferon alone. They were treated with Pegylated interferon plus ribavirin. At the end of therapy, HCV RNA was still detectable. Several months after stopping treatment, aminotransferase level normalized and HCV RNA became undetectable. No case of sustained viral response happening several months after therapy has been yet described. During long-term follow-up of non-responders, when a persistent normalization of aminotransferase level is observed after stopping treatment, viral clearance could be suspected.

Long-term tillage effects on soil metolachlor sorption and desorption behavior

Sorption and desorption are two important processes that influence the amount of pesticides retained by soils. However, the detailed sorption mechanisms as influenced by soil tillage management are unclear. This study examined the sorption and desorption characteristics of metolachlor [2-chloro-N-(2-ethyl-6-methyphenyl)-N-(2-methoxy-1-methylethyl)-acetamide] using the soil samples collected from the long-term conservation tillage (CnT) and conventional tillage (CT) research plots established in 1979 in Darlinton, SC. Humic acid (HA) and humin were extracted from the soils and used in the sorption experiments along with the whole soil samples. The sorption experiments were conducted using a batch-equilibration method. Three sequential desorption rinses were carried out following the sorption experiments. By comparing metolachlor sorption and desorption results we observed hysteresis for all soil samples and their organic matter fractions. Sorption nonlinearity (N) and hysteresis were dependent on the structure and composition of soil organic matter (SOM), e.g., Freundlich isotherm exponents (N) of HA and humin from CnT were higher than those of CT treatment, which may be related to high aromaticity of SOM fractions in CT treatment. Sorption capacity (K'f) was positively correlated with soil organic carbon (SOC) content. These results show that long-term tillage management can greatly affect metolachlor sorption and desorption behavior probably by qualitative differences in the structural characteristics of the humic substances.

Regulation of Staphylococcus aureus type 5 and type 8 capsular polysaccharides by CO(2)

Staphylococcus aureus expression of capsular polysaccharide type 5 (CP5) has been shown to be downregulated by CO(2). Here we show that CO(2) reduces CP5 expression at the transcriptional level and that CO(2) regulates CP8 expression depending on the genetic background of the strains. Growth in the presence of air supplemented with 5% CO(2) caused a significant decrease in CP8 expression in four S. aureus strains, a marginal effect in four strains, and higher CP8 expression in strain Becker. Absolute CP8 expression in the nine S. aureus strains differed largely from strain to strain. Four groups of strains were established due to sequence variations in the promoter region of cap5 and cap8. To test whether these sequence variations are responsible for the different responses to CO(2), promoter regions from selected strains were fused to the reporter gene xylE in pLC4, and the plasmids were electrotransformed into strains Becker and Newman. XylE activity was negatively regulated by CO(2) in all derivatives of strain Newman and was always positively regulated by CO(2) in all derivatives of strain Becker. Differences in promoter sequences did not influence the pattern of CP8 expression. Therefore, the genetic background of the strains rather than differences in the promoter sequence determines the CO(2) response. trans-acting regulatory molecules may be differentially expressed in strain Becker versus strain Newman. The strain dependency of the CP8 expression established in vitro was also seen in lung tissue sections of patients with cystic fibrosis infected with CP8-positive S. aureus strains.

Subinhibitory clindamycin differentially inhibits transcription of exoprotein genes in Staphylococcus aureus

It has long been known that certain antibiotics, at subinhibitory concentrations, differentially inhibit the synthesis of alpha-hemolysin and other staphylococcal virulence factors. In this report, we show that subinhibitory clindamycin (SBCL) eliminates production of nearly all exoproteins by Staphylococcus aureus but has virtually no effect on cytoplasmic proteins. The effect was abolished by a gene conferring resistance to macrolides-lincosamides-streptogramin B, showing that differential inhibition of protein synthesis is responsible; remarkably, however, subinhibitory clindamycin blocked production of several of the individual exoprotein genes, including spa (encoding protein A), hla (encoding alpha-hemolysin), and spr (encoding serine protease), at the level of transcription, suggesting that the primary effect must be differential inhibition of the synthesis of one or more regulatory proteins. In contrast to earlier reports, however, we found that subinhibitory clindamycin stimulates synthesis of coagulase and fibronectin binding protein B, also at the level of transcription. agr and sar expression was minimally affected by subinhibitory clindamycin. These effects varied from strain to strain and do not seem to be responsible for the effects of subinhibitory clindamycin on the overall exoprotein pattern.

Mitochondrial FtsZ in a chromophyte alga

A homolog of the bacterial cell division gene ftsZ was isolated from the alga Mallomonas splendens. The nuclear-encoded protein (MsFtsZ-mt) was closely related to FtsZs of the alpha-proteobacteria, possessed a mitochondrial targeting signal, and localized in a pattern consistent with a role in mitochondrial division. Although FtsZs are known to act in the division of chloroplasts, MsFtsZ-mt appears to be a mitochondrial FtsZ and may represent a mitochondrial division protein.

Policy instruments for reducing toxic releases. The effectiveness of state information and enforcement actions

This article analyzes the extent to which different policy instruments explain toxic reductions among the states. Data from the Toxics Release Inventory (TRI) and other sources are used to assess the effect of various policy instruments, while holding economic factors constant. State TRI information programs, enforcement action, and direct regulation all matter in reducing toxic releases. Interestingly, the informational tool seems to matter more than both authoritative tools. The findings also support the idea that the interaction of policy instruments as well as the match between policy tools and policy context may account for a portion of the results.

Localization of Staphylococcus aureus in infected airways of patients with cystic fibrosis and in a cell culture model of S. aureus adherence

Staphylococcus aureus causes chronic respiratory tract infections in patients with cystic fibrosis (CF). Using immunofluorescence and scanning and transmission electron microscopy we located S. aureus in lung specimens of three infected CF patients, in a nasal polyp of one CF patient, and in a suspension cell culture system of primary nasal epithelial cells in vitro. Very little of S. aureus was attached to the lung epithelium, whereas abundant S. aureus was detectable in the mucus of obstructed airways. Similarly, S. aureus adhered to components of secreted mucus on primary nasal epithelial cells of CF patients and healthy control subjects, grown as cell balls in vitro (bacteria/cell +/- SD: CF: 21.9 +/- 1.5; controls: 22. 0 +/- 5.8). Mucus depletion of cell balls prior to incubation with S. aureus resulted in a significantly reduced binding (bacteria/cell +/- SD: CF: 4.2 +/- 0.3; P < 0.001; controls: 5.0 +/- 1.3; P < 0. 007). Binding of S. aureus to cell balls from CF patients or control subjects did not differ significantly. When cell balls were treated with human neutrophil elastase, hypersecretion caused removal of S. aureus from cell-associated mucus. The results suggest that S. aureus adheres primarily to mucus components of the respiratory epithelium and that significant differences do not exist in binding of S. aureus to CF or non-CF cells.

[Regulation of Staphylococcus aureus capsular polysaccharide type 5: in vitro and in vivo inhibition by CO2]

Staphylococcus aureus capsular polysaccharide type 5 (CP5) expression was investigated in lung tissue and nasal polyps of two cystic fibrosis (CF) patients, in rats and in vitro using ELISA and immunofluorescence. In CF tissues, S. aureus expressed protein A and teichoic acid but only 1-5% of cells expressed CP5. When rats were challenged with CP5-positive S. aureus in the granuloma pouch model, only 1-5% CP5-positive cells were detectable in pouch exsudates. CF and pouch isolates, however, re-expressed CP5 (70-90% of cells) when grown in vitro with air. Addition of 1% CO2 or more to air or to O2/N2 gas mixtures reduced CP5 expression significantly (p < 0.001) in a dose-dependent manner (1-6% CP5-positive cells). The results show that S. aureus does not produce CP5 in CF airways and in rat granuloma pouches and that CO2 is an environmental signal which regulates CP5 expression.

Regulation of Staphylococcus aureus capsular polysaccharide type 5: CO2 inhibition in vitro and in vivo

Staphylococcus aureus capsular polysaccharide type 5 (CP5) expression was investigated in lung tissue and nasal polyps of two cystic fibrosis (CF) patients, in rats, and in vitro using ELISA and IFA. In CF tissues, S. aureus expressed protein A and teichoic acid but only 1%-5% of cells expressed CP5. When rats were challenged with CP5-positive S. aureus in the granuloma pouch model, only 1%-5% of CP5-positive cells were detectable in pouch exudates. CF and pouch isolates, however, reexpressed CP5 (70%-90% of cells) when grown in vitro with air. Addition of > or = 1% CO2 to air or to O2/N2 gas mixtures reduced CP5 expression significantly (P < .001) in a dose-dependent manner (6%-1% CP5-positive cells). The results show that S. aureus does not produce CP5 in CF airways and in rat granuloma pouches and that CO2 is an environmental signal that regulates CP5 expression.

Adverse perinatal outcome in parturients who use crack cocaine

OBJECTIVE

To determine the risk of adverse pregnancy outcome among crack cocaine users in a large homogeneous prenatal population with objective documentation of drug use.

METHODS

A retrospective cohort study was performed on a population of inner-city women who were offered routine voluntary urine drug screening and who delivered between January and December 1992 at a large county hospital. The study population consisted of 483 users (positive drug screens) and 3158 non-users (negative drug screens). Univariate analysis and multiple logistic regression were used to identify the relation between crack cocaine use and adverse perinatal outcome.

RESULTS

Users were significantly more likely than nonusers to deliver low birth weight (LBW) infants (31.3% versus 14.9%; crude odds ratio [OR] 2.6; 95% confidence interval [CI] 2.1, 3.2), growth-restricted infants (29.0% versus 13.0%; crude OR 2.7; 95% CI 2.2, 3.4), and preterm infants (28.2% versus 17.1%; crude OR 1.9; 95% CI 1.5, 2.4). In addition, users were more likely to have abruptions (3.3% versus 1.1%; crude OR 3.0; 95% CI 1.6, 5.6) and infants with low 5-minute Apgar scores (7.9% versus 4.5%; crude OR 1.8; 95% CI 1.2, 2.7). After adjusting for confounders (including alcohol use and smoking), only the risks of LBW and fetal growth restriction (FGR) remained significant, with adjusted OR 1.6 (95% CI 1.03, 2.4) and adjusted OR 1.7 (95% CI 1.2, 2.3), respectively. Although there was no significant difference in the rate of low 5-minute Apgar scores between users and non-users after controlling for confounders, users with a positive urine drug screen within 1 week of delivery were significantly more likely than non-users to deliver infants with low 5-minute Apgar scores: crude OR 2.4; adjusted OR 2.0 (95% CI 1.1, 3.7).

CONCLUSION

In this inner-city population, crack cocaine use is associated with adverse pregnancy outcomes, as noted by increased risks of LBW and FGR.

A team approach to the treatment of dysphagia

This paper looks at dysphagia and the difficulties it causes for patients and those caring for them. It describes an initiative developed to ensure a consistent multidisciplinary approach to management of patients with dysphagia.

Cleavage of lymphocyte surface antigens CD2, CD4, and CD8 by polymorphonuclear leukocyte elastase and cathepsin G in patients with cystic fibrosis

Polymorphonuclear leukocytes (PMN) accumulating in airways of patients with cystic fibrosis (CF) as a response to chronic endobronchial bacterial lung infection, release lysosomal serine proteinases such as PMN-elastase at concentrations of approximately 0.5 microM to 5 microM into the airway lumen. Immunohistology of CF lung material and fluorescence activated cell sorter analysis of sequential CF bronchoalveolar lavages demonstrated loss of the CD4 and CD8 Ag on CD3+ T lymphocytes in sputum-filled airways. In 10 CF sputum samples 1.0%, 19.1%, and 15.7% of all CD3+ T lymphocytes expressed CD4, CD8, and CD2, respectively. Incubation of CF sputum supernatant fluids with peripheral blood T lymphocytes resulted in total reduction of CD4 and CD8 but not CD2. Addition of alpha 1-proteinase inhibitor abolished surface Ag cleavage completely. Purified PMN-elastase and cathepsin G cleaved CD2, CD4, and CD8 on peripheral blood T lymphocytes at proteinase concentrations of 0.83 to 8.3 microM in a dose-dependent manner. Cleaved CD4 and CD8 were reexpressed on the surface of T lymphocytes after 24 h in the absence of PMN-elastase. Incubation of a CD4+ T cell clone with PMN-elastase lead to a significant reduction of cytotoxicity toward target cells and significantly reduced IL-2 and IL-4 production. The results suggest a temporary functional impairment of T lymphocytes in foci of high inflammation characterized by stimulated PMN, which may lower tissue destruction.

Cleavage of lymphocyte surface antigens CD2, CD4, and CD8 by polymorphonuclear leukocyte elastase and cathepsin G in patients with cystic fibrosis

Polymorphonuclear leukocytes (PMN) accumulating in airways of patients with cystic fibrosis (CF) as a response to chronic endobronchial bacterial lung infection, release lysosomal serine proteinases such as PMN-elastase at concentrations of approximately 0.5 microM to 5 microM into the airway lumen. Immunohistology of CF lung material and fluorescence activated cell sorter analysis of sequential CF bronchoalveolar lavages demonstrated loss of the CD4 and CD8 Ag on CD3+ T lymphocytes in sputum-filled airways. In 10 CF sputum samples 1.0%, 19.1%, and 15.7% of all CD3+ T lymphocytes expressed CD4, CD8, and CD2, respectively. Incubation of CF sputum supernatant fluids with peripheral blood T lymphocytes resulted in total reduction of CD4 and CD8 but not CD2. Addition of alpha 1-proteinase inhibitor abolished surface Ag cleavage completely. Purified PMN-elastase and cathepsin G cleaved CD2, CD4, and CD8 on peripheral blood T lymphocytes at proteinase concentrations of 0.83 to 8.3 microM in a dose-dependent manner. Cleaved CD4 and CD8 were reexpressed on the surface of T lymphocytes after 24 h in the absence of PMN-elastase. Incubation of a CD4+ T cell clone with PMN-elastase lead to a significant reduction of cytotoxicity toward target cells and significantly reduced IL-2 and IL-4 production. The results suggest a temporary functional impairment of T lymphocytes in foci of high inflammation characterized by stimulated PMN, which may lower tissue destruction.