Microbiological quality of irrigation water on highly diverse fresh produce smallholder farms: elucidating environmental routes of contamination.

AIM: To evaluate the microbiological safety, potential multidrug-resistant bacterial presence and genetic relatedness (DNA fingerprints) of Escherichia coli isolated from the water-soil-plant nexus on highly diverse fresh produce smallholder farms. METHODS AND RESULTS: Irrigation water (n = 44), soil (n = 85), and fresh produce (n = 95) samples from six smallholder farms with different production systems were analysed for hygiene indicator bacterial counts and the presence of shigatoxigenic E. coli and Salmonella spp. using standard microbiological methods. Identities of isolates were confirmed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and the genetic relatedness of the E. coli isolates determined using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) analysis. Irrigation water E. coli levels ranged between 0 and 3.45 log MPN/100 ml-1 with five farms having acceptable levels according to the World Health Organization limit (3 log MPN/100 ml-1). Fresh produce samples on four farms (n = 65) harboured E. coli at low levels (<1 log CFU/g-1) except for one sample from kale, spring onion, green pepper, onion, and two tomato samples, which exceeded international acceptable limits (100 CFU/g-1). Only one baby carrot fresh produce sample tested positive for Salmonella spp. Of the 224 samples, E. coli isolates were identified in 40% (n = 90) of all water, soil, and fresh produce types after enrichment. Additionally, the DNA fingerprints of E. coli isolates from the water-soil-plant nexus of each respective farm clustered together at high similarity values (>90%), with all phenotypically characterized as multidrug-resistant. CONCLUSIONS: The clustering of E. coli isolated throughout the water-soil-plant nexus, implicated irrigation water in fresh produce contamination. Highlighting the importance of complying with irrigation water microbiological quality guidelines to limit the spread of potential foodborne pathogens throughout the fresh produce supply chain.

Life Cycle Assessment of an Avocado: Grown in South Africa-Enjoyed in Europe.

Food production is known to have significant environmental impacts, with the main contributors residing in the farming and transportation life cycle phases. Of the various food products transported around the world, avocados have increasingly gained attention as a high-commodity superfood. Avocados require specific climatic and agricultural conditions for farming, with the most fertile land and conditions located outside Europe. Consequently, most avocados consumed in Europe are imported over vast geographical distances, with little information available to quantify the environmental impacts of this imported superfood. This paper aims to present the most detailed life cycle assessment results of an avocado cultivated, grown and harvested in the Limpopo Province of South Africa and exported to the European market for sale and consumption. A life cycle assessment was developed for the farming, harvesting, handling, packaging, ripening, transportation, and carbon sequestration potential of the avocado, and it was used to conduct a holistic life cycle assessment. Input data was obtained through an 18-month data collection campaign across the relevant stakeholders. A baseline 'business-as-usual' scenario is focused on throughout this study, and scope for optimisation is identified for each life cycle phase where applicable, accompanied by uncertainty analyses. Results show a total carbon input of 904.85 kg CO2e/tonne. Mitigating this, 521.88 kg CO2e/tonne is offset, resulting in a net carbon footprint of 382.97 kg CO2e/tonne with uncertainty ranges of -23.22 to +58.69 kg CO2e/tonne, normalised to 57.45 g CO2e/avocado grown in South Africa and sold in Europe. The environmental impacts of the avocado industry under consideration are largely mitigated by the "nature first" philosophy of the farming and logistics enterprises, which have made significant investments in reducing emissions. Sensitivity analyses indicate that implementing large-scale renewable energy, using alternative packaging instead of cardboard, and selling avocados unripened could further enable the farming enterprise to achieve Net Zero objectives. These measures could reduce baseline emissions from 382.97 kg CO2e/tonne to a theoretical -68.54 kg CO2e/tonne, representing a 117.9% decrease. Although this study does not quantify climate change impacts, qualitative analyses suggest that climate change will have a net negative effect on the avocado industry in South Africa. These regions, typically located in micro-climates, are projected to become wetter and warmer, adversely affecting crop phenology, pest control, road conditions, management complexity, farmer livelihoods, and food security. The study recommends large-scale implementation of the optimisation strategies identified to achieve Net Zero objectives and the development of proactive climate change mitigation strategies to enhance the resilience of avocado supply chains to future stressors. These insights are crucial for policymakers, industry stakeholders, and consumers aiming to promote sustainability in the avocado market.

Outcomes of Chronically Anticoagulated Patients Undergoing Split-Thickness Skin Grafting for Diabetic Foot Ulcers.

OBJECTIVE: Split-thickness skin grafting (STSG) is commonly used for wound closure in diabetic foot ulcers (DFUs). In many cases, patients with diabetes present on long-term anticoagulation therapy. The complications associated with anticoagulants can be discouraging to surgeons considering STSG. The goal of this study was to evaluate STSG outcomes in the setting of chronic anticoagulation across a large, multicenter database. METHODS: The authors queried the TriNetX Network, which provides access to electronic medical records for more than 75 million patients, to search for patients with a history of DFUs treated with STSG. They divided those found into two groups: long-term anticoagulant use prior to grafting and no long-term anticoagulant use. After matching, the researchers evaluated outcomes following STSG after 1 month and 5 years. RESULTS: The authors identified 722 patients on chronic anticoagulation with DFUs who were treated with STSG; 446 of these patients were matched to 446 patients with no prior anticoagulation. One month following STSG, the anticoagulated group showed no significant increase in death, graft failure, or regrafting. At 5 years, there was no significant increase in mortality, graft failure, regrafting, or lower extremity amputation rates. CONCLUSIONS: Chronic anticoagulation therapy does not lead to increased short- or long-term postoperative complications such as graft failure, regrafting, or increased amputation rates following STSG for wound closure. Negative outcomes following STSG for DFUs in chronically anticoagulated individuals are minimal, and grafting should be performed without hesitation.

The Ins and Outs of IV Fluids in Hemodynamic Resuscitation.

OBJECTIVES: Concise definitive review of the physiology of IV fluid (IVF) use in critically ill patients. DATA SOURCES: Available literature on PubMed and MEDLINE databases. STUDY SELECTION: Basic physiology studies, observational studies, clinical trials, and reviews addressing the physiology of IVF and their use in the critically ill were included. DATA EXTRACTION: None. DATA SYNTHESIS: We combine clinical and physiologic studies to form a framework for understanding rational and science-based use of fluids and electrolytes. CONCLUSIONS: IVF administration is among the most common interventions for critically ill patients. IVF can be classified as crystalloids or colloids, and most crystalloids are sodium salts. They are frequently used to improve hemodynamics during shock states. Many recent clinical trials have sought to understand which kind of IVF might lead to better patient outcomes, especially in sepsis. Rational use of IVF rests on understanding the physiology of the shock state and what to expect IVF will act in those settings. Many questions remain unanswered, and future research should include a physiologic understanding of IVF in study design.

The highs and lows of blood pressure: toward meaningful clinical targets in patients with shock.

OBJECTIVE: Measurement of blood pressure is fundamental for the management of patients in shock, yet the physiological basis and meaning of blood pressure measurements are complex and often not well understood. This article is in two parts: part 1 deals with the mechanical and physiological aspects of blood pressure and its measurement and part 2 deals with the role of changes in regional resistances in the determination of tissue perfusion and bedside approaches to management of shock. DATA SOURCE AND SELECTION: This review is based on physiological principles from texts and experimental studies which elucidate some of the key principles. The views expressed are the author's synthesis of the views of others and his own opinions. DATA SYNTHESIS: Arterial blood pressure is a major determinant of regional flow and is often used as a surrogate indicator of tissue perfusion, but in reality, it is a poor indicator of blood flow. Blood pressure is determined by cardiac output (total flow) and total vascular resistance. Distribution of flow for a given blood pressure is dependent on the relative values of resistances in different vascular beds. If this distribution of resistances were known, this would be the ideal guide to therapy. Unfortunately, regional resistances cannot be assessed in the clinical setting, and so we are left with blood pressure as a guide to therapy. CONCLUSIONS: This article discusses the implications of these points and explores factors that need to be taken into account when designing empiric trials to determine appropriate blood pressure targets for patients in shock. Even if well-studied empirically developed guidelines become available, it likely still will be important to individualize patient management and approaches for this are discussed too.

A two-centre experience of tonsil biopsies in the investigation of patients with tonsillar asymmetry.

INTRODUCTION: We aim to evaluate our experience of tonsil biopsies in the investigation of patients presenting with asymmetrical tonsils. METHODS: A two-centre retrospective analysis of all patients who underwent histology sampling of the palatine tonsils between 1 January 2013 and 31 December 2018 was completed. Data collected included patient demographics, method of obtaining tonsil tissue, histological diagnosis and need for repeat tissue sampling. A follow-up period of 36 months was allowed to establish whether any patients re-presented with missed diagnoses. RESULTS: In total, 937 patients were included for analysis: 375 (40.0%) had a biopsy, of which 191 (50.9%) were performed in clinic. The mean duration from initial appointment with the ear, nose and throat clinic to tissue sample collection was 17.6 days (range 0-327 days) for all biopsies, reducing to 0.2 days (range 0-17 days) for biopsies performed in clinic. This was significantly shorter than for tonsillectomies (mean 38.9 days, range 0-444 days; p<0.05). Of the patients who underwent tonsil biopsy, six (1.6%) had malignancy that was not unequivocally diagnosed on initial biopsy. In all six patients, prior clinical suspicion was high, and repeat tissue sampling was undertaken on receipt of negative histology results. CONCLUSIONS: Tonsil biopsy is a viable alternative to tonsillectomy for histology in the assessment of tonsil asymmetry. Tonsil biopsy in the outpatient setting has reduced surgical morbidity, significantly less delay in diagnosis, less inconvenience for patients and lower healthcare costs compared with formal tonsillectomy. Although tonsil biopsies should not be used in isolation, they can be useful in the investigation of patients presenting with tonsillar asymmetry.

Preventing Iatrogenic Fibula Fractures Using the Push-Pull Technique: A Biomechanical Comparison of Unicortical Versus Bicortical Post Screws.

BACKGROUND: Displaced diaphyseal fractures can be reduced using the push-pull technique, wherein a plate is affixed to the distal fragment of the fracture, a post screw is placed proximal to the plate, and a lamina spreader creates distraction. This study evaluated the load to failure and mechanism of failure of bicortical and unicortical post screws during reduction. MATERIALS AND METHODS: Four matched pairs of cadaver legs were subjected to a 2-cm oblique osteotomy simulating a displaced, oblique diaphyseal fracture. A 6-hole compression plate was affixed to the distal fragment with 2 unicortical locking screws, and a 12-mm unicortical or 20-mm bicortical screw was inserted as a post screw proximal to the plate. A lamina bone spreader was used to exert a distraction force between the plate and the post screw. A mechanical actuator simulated the distraction procedure until failure. Maximum applied load, displacement, and absorbed energy were recorded and compared across unicortical and bicortical groups by paired t tests. RESULTS: At maximum load, we found statistically significant differences in displacement (P=.003) and energy absorbed (P=.022) between the two groups. All unicortical screws failed through screw toggle and bone cut-out. Bicortical screws failed through bending, with no visible damage to the bone at the screw site. CONCLUSION: When diaphyseal fractures are significantly shortened and require a greater distraction force to achieve reduction, bicortical screws demonstrate a higher mechanical load to failure and increased bone loss from the screw-removal site. A unicortical post screw may be used if minimal distraction is needed. [Orthopedics. 2024;47(5):308-312.].

The ups and downs of heart rate.

OBJECTIVE: To review the physiology of the regulation and determinants of heart rate and the significance in the management of critically ill patients. DATA SOURCES: The MEDLINE database, references from selected articles, and the author's personal database. DATA SYNTHESIS: This review begins with the regulation of cardiac output and heart rate during exercise because this demonstrates the range of physiological responses in the normal human. This analysis shows that change in heart rate is a major component of the cardiovascular system's ability to adjust cardiac output and a number of regulatory systems control heart rate. When heart rate responses are limited because of disease or pharmacologic reasons, changes in stroke volume must compensate, but the capacity to do so is limited by the passive filling characteristics of the ventricles. On the other side, high heart rates increase myocardial oxygen demand, which can be a problem in patients with fixed coronary artery disease. CONCLUSION: Heart rate must be interpreted in the context of the patient's overall hemodynamic condition. The prudent physician must ask why is the heart rate high, what will be achieved by lowering the heart rate, and, finally, what are the consequences of lowering the heart rate?

Antimicrobial use on Canadian dairy farms.

Antimicrobial use (AMU) data are critical for formulating policies for containing antimicrobial resistance. The present study determined AMU on Canadian dairy farms and characterized variation in AMU based on herd-level factors such as milk production, somatic cell count, herd size, geographic region and housing type. Drug use data were collected on 89 dairy herds in 4 regions of Canada, Alberta, Ontario, Québec, and the Maritime provinces (Prince Edward Island, New Brunswick, and Nova Scotia) for an average of 540 d per herd. Dairy producers and farm personnel were asked to deposit empty drug containers into specially provided receptacles. Antimicrobial use was measured as antimicrobial drug use rate (ADUR), with the unit being number of animal defined-daily doses (ADD)/1,000 cow-days. Antimicrobial drug use rates were determined at farm, region, and national level. Combined ADUR of all antimicrobial classes was 14.35 ADD/1,000 cow-days nationally. National level ADUR of the 6 most commonly used antimicrobial drug classes, cephalosporins, penicillins, penicillin combinations, tetracyclines, trimethoprim-sulfonamide combinations, and lincosamides were 3.05, 2.56, 2.20, 1.83, 0.87, and 0.84 ADD/1,000 cow-days, respectively. Dairy herds in Ontario were higher users of third-generation cephalosporins (ceftiofur) than in Québec. Alberta dairy herds were higher users of tetracyclines in comparison to Maritimes. Antimicrobial drug use rate was higher via systemic route as compared with intramammary and other routes of administration (topical, oral, and intrauterine). The ADUR of antimicrobials used intramammarily was higher for clinical mastitis treatment than dry cow therapy. For dry cow therapy, penicillin ADUR was greater than ADUR of first-generation cephalosporins. For clinical mastitis treatment, ADUR of intramammary penicillin combinations was greater than ADUR of cephapirin. Herd-level milk production was positively associated with overall ADUR, ADUR of systemically administered ceftiofur, cephapirin administered for dry cow therapy, and pirlimycin administered for clinical mastitis treatment. Herd size and ADUR of systemically administered ceftiofur were also positively associated. In conclusion, ß-lactams were most commonly used on Canadian dairy farms. Among antimicrobials of very high importance in human medicine, the use of fluoroquinolones was rare, whereas third-generation cephalosporins and penicillin combinations containing colistin were used very frequently on Canadian dairy farms.

Trainee-trainer outcomes in mastoid surgery: a comparative study.

BACKGROUND: Mastoid exploration remains an advanced, mainstay operation within ENT, in which the surgical trainees' role has been debated. This audit compares mastoid exploration outcomes between trainees and consultants. METHODS: Cortical mastoidectomy, atticotomy, atticoantrostomy, modified radical mastoidectomy, combined-approach tympanoplasty and revision mastoidectomy operations performed between 2009 and 2020 were reviewed. Complications assessed were: facial palsy, labyrinth injury, dead ear, disease recurrence and time to recurrence. The chi-square test was used to determine significant associations. RESULTS: A total of 118 operations were surveyed. Thirty-five per cent of procedures (n = 41) were performed by trainees under supervision, and 65 per cent (n = 77) were carried out solely by consultants. Patients from 5 per cent of trainees' operations (n = 2) developed recurrence, compared with 7.8 per cent of consultants' (n = 6) (p = 0.55). No other complications developed in either group. CONCLUSION: The results corroborate those of other studies, indicating no significant increase in complication rate from consultants to trainees. Trainees likely completed less complicated cases. The stepwise incorporation of trainees did not compromise patient safety.

Exposure of construction workers to hazardous emissions in highway rehabilitation projects measured with low-cost sensors.

Construction workers on highway rehabilitation projects can be exposed to a combination of traffic- and construction-related emissions. To assess the personal exposure a worker experiences, a portable battery-operated Air Quality Device (AQD) was utilised to measure emissions during normal construction operations of a major road rehabilitation project. Emissions measured were nitrogen dioxide (NO2), Total Volatile Organic Compounds (TVOCs) and Particulate Matter (PM10, PM2.5, and PM1). The objective of the paper is to document the hazardous emissions that construction workers may be exposed to and allow for a basis of informed decision making to mitigate the risks of a road construction project. Most critically, this article is designed to raise awareness of the potential impact to a worker's wellbeing as well as highlight the need for further research. Through statistical analysis, asphalt paving was identified as the most hazardous activity in terms of exposure relative to other activities. This activity was further assessed using discrete-time Markov chain Monte Carlo simulations with results indicating a high probability that workers may be exposed to greater hazardous emission concentrations than measured. Limiting the distance to the source of emissions, large-scale use of warm-mix asphalt and reducing the idling times of construction vehicles were identified as practical mitigation measures to reduce exposure and aid in achieving zero-harm objectives. Finally, it is found that males are more susceptible to long-term implications of hazardous emission inhalation and should be more aware if the scenarios they might work in expose them to this.

A phase II study of two topotecan regimens evaluated in recurrent platinum-sensitive ovarian, fallopian tube or primary peritoneal cancer: a Gynecologic Oncology Group Study (GOG 146Q).

OBJECTIVE: To evaluate the efficacy and safety of topotecan in patients with recurrent ovarian, primary peritoneal, and fallopian tube carcinomas. METHODS: A randomized phase II analysis of platinum-sensitive patients with measurable disease was performed independently assessing intravenous topotecan 1.25 mg/m2 daily×5 every 21 days (regimen I) and topotecan 4.0 mg/m2/day on days 1, 8, and 15 of a 28-day cycle (regimen II). All patients were treated until disease progression, unmanageable toxicity, or patient refusal. Insufficient accrual related to regimen I resulted in a redesign of the study as a single arm phase II trial assessing only regimen II. More complete efficacy data is presented for regimen II as enrollment on regimen I was insufficient for some analyses. RESULTS: A total of 81 patients were enrolled. One patient was ineligible. Fifteen patients received regimen I, while 65 patients were treated with regimen II. The response rate on regimen I (daily×5) was 27% (90% CI: 10-51%) and 12% (90% CI: 6-21%) on regimen II (weekly). The median PFS and OS were 4.8 and 27.8 months, respectively, for regimen II. Grade 3/4 neutropenia rate was 93% with daily×5 dosing and 28% for weekly treatment. Febrile neutropenia was very low in both groups. CONCLUSION: The weekly regimen of topotecan appeared less active but resulted in less toxicity than the daily regimen in platinum-sensitive recurrent ovarian cancer patients.

Surgeons' and anesthesiologists' perceptions of turnover times.

BACKGROUND: Perception of turnovers may be influenced less by actual turnover times per se than by a mental model of factors influencing turnover times. METHODS: A survey was performed at a U.S. academic hospital in 2010. Each of the 78 subjects estimated characteristics of his/her turnover times in 2009. Responses were compared with the actual times. RESULTS: Numbers of comments were not proportional to actual total waiting times experienced. Surgeons with 2 or more comments (n = 10) averaged the same numbers of turnovers as did surgeons who made 1 or no comments (n = 13) (P = 0.62). Four of the 10 surgeons with 2 or more comments averaged <2 turnovers per month ("very few turnovers"). Perceptions of turnover times were influenced by opinion about team activity during shift change. Most (>79%) subjects thought that the time of the day with the subject's largest number of prolonged (>45 minutes) turnovers was at least 2 hours later than actual (P < 0.0001). Although most prolonged turnovers occurred around noon, 8 surgeons mentioned shift change qualitatively, and most (68%, P = 0.002) subjects estimated a time overlapping with shift change. Surgeons overall overestimated their observed percentage of prolonged turnovers (P = 0.020), and anesthesiologists' estimates were overall unbiased. Surgeons' bias cannot be explained by knowing times of a longer interval such as "skin to skin," because the other surgeons, with very few turnovers, had responses that were essentially identical (P ≥ 0.87). When we corrected for each subject's actual mean turnover time, surgeons' estimates for their averages were longer than were anesthesiologists' estimates (P = 0.002). Responses were again essentially indistinguishable from those of subjects with very few turnovers (P ≥ 0.23). CONCLUSIONS: Managers should not rely on surgeons or anesthesiologists for their expert judgment on turnover times. Managers should also not interpret comments about turnover times as literally referring to the time, but instead as factors perceived as contributing to the time (e.g., attitude about the facility and the activity of its personnel).

Development of comprehensive two-dimensional liquid chromatography for investigating aging of plastic bonded explosives.

The feasibility of measuring the aging and degradation of PBX 9501 via online two dimensional liquid chromatography (LC × LC) is investigated, and a preliminary instrumental setup and method is developed. Plastic-Bonded eXplosive (PBX) 9501 is nominally composed of 94.9 wt% HMX, 2.5 wt% Estane® 5703 (poly (ester urethane)), 2.5 wt% BDNPA/F (nitroplasticizer), 0.1 wt% Irganox 1010 and PBNA (N-phenyl-naphthylamine) at low concentrations. When exposed to various environmental conditions, PBX 9501 will degrade through different pathways. Because PBX 9501 is composed of both low molecular weight compounds (BDNPA/F, Irganox 1010, PBNA, and potential degradation products) and high molecular weight compounds (Estane® 5703), analysis is normally performed via two independent analyses. The low molecular weight species are analyzed via high pressure liquid chromatography (HPLC) and the high molecular weight species via size exclusion chromatography (SEC). While these individual techniques yield information about the aging of PBX 9501, the combination of HPLC and SEC (i.e. HPLC × SEC) can simplify and streamline the analyses while also providing additional chemical information. A simplified sample preparation method is proposed for LC × LC analysis. Various SEC columns and HPLC column selection, flow rate, and gradient ramps were investigated for their application of measuring aged PBX 9501. Finally, two LC × LC separations of a library standard of PBX 9501 and a sample of aged PBX 9501 are compared.

Predicting orthopedic surgeons' preferences for peripheral nerve blocks for their patients.

BACKGROUND: A 2002 survey of 468 Canadian orthopedic surgeons found that the "two principal reasons regional anesthesia is not favored" are "delays in operating rooms" and "unpredictable success." We reanalyzed the data from the study to evaluate whether these concerns were the best predictors of an individual surgeon's willingness to use peripheral nerve blocks for their patients. METHODS: Of the five procedures included in the survey, three had relevant questions for our reanalysis of the results: arthroscopic shoulder surgery, arthroscopic anterior cruciate ligament reconstruction, and total knee replacement. RESULTS: A surgeon's preference for peripheral nerve block for him or herself strongly predicted his or her anesthetic preference for patients (all P < 0.001). Concordance rates were 89% for arthroscopic shoulder surgery, 87% for anterior cruciate ligament reconstruction, and 93% for total knee replacement. There was almost no incremental predictive value for the surgeon's preference for patients from the surgeon's perception of the times to perform a block (P > or = 0.27) or perception of block success rate (P > or = 0.30). There was also almost no direct predictive value for the surgeon's preference for patients from the surgeon's perception of the times to perform a block (Kendall's tau < or = 0.04, P > or = 0.28) or perception of block success rate (Kendall's tau < or = 0.02, P > or = 0.24). An economically important percentage of surgeons (37%, 95% confidence interval: 32%-41%) would choose a peripheral nerve block for their own surgery for some, but not all, of the procedures (i.e., for 1 or 2 versus 0 or 3). CONCLUSIONS: A surgeon's preference for peripheral nerve blocks for his or her own surgery predicted a surgeon's preference for his or her patients. Perceptions of delays and success rate did not add sufficient incremental information to the surgeon's preferences to be of economic importance. These results are important to better forecast the net economic impact on an anesthesia group of a regional block team.

Variations in pulmonary artery occlusion pressure to estimate changes in pleural pressure.

OBJECTIVE: A readily available assessment of changes in pleural pressure would be useful for ventilator and fluid management in critically ill patients. We examined whether changes in pulmonary artery occlusion pressure (Ppao) adequately reflect respiratory changes in pleural pressure as assessed by changes in intraesophageal balloon pressure (Peso). We studied patients who had a pulmonary catheter and esophageal balloon surrounding a nasogastric tube as part of their care (n=24). We compared changes in Ppao (dPpao) to changes in Peso (dPeso) by Bland-Altman and regression analysis. Adequacy of balloon placement was assessed by performing Mueller maneuvers and adjusting the position to achieve a ratio of dPeso to change in tracheal pressure (dPtr) of 0.85 or higher. This was achieved in only 14 of the 24 subjects. We also compared dCVP to dPeso. The dPpao during spontaneous breaths and positive pressure breaths gave a good estimate of Peso but generally underestimated dPeso (bias=2.2 +8.2 and -3.9 cmH2O for the whole group). The dCVP was not as good a predictor (bias=2.9 +10.3 and -4.6). In patients who have a pulmonary artery catheter in place dPpao gives a lower estimate of changes in pleural pressure and may be more reliable than dPeso. The dCVP is a less reliable predictor than changes in pleural pressure.

Diversity in smooth muscle thin filament composition.

Two classes of smooth muscle thin filament can be identified and separated based on their interaction with antibodies specific either to filamin or to caldesmon. One type is composed of actin, tropomyosin and filamin and the other of actin, tropomyosin and caldesmon.

Inner ear histopathology in "nervous Pointer dogs" with severe hearing loss.

Ten puppy dogs (82, 131 or 148 days-old) from a Pointer cross-colony, exhibiting a juvenile severe hearing loss transmitted as an autosomal recessive trait, were used for histopathological characterization of the inner ear lesion. Immunostaining with calbindin, Na,K-ATPase, cytokeratins, S100, S100A1 and S100A6 antisera were helpful in identifying the different cell types in the degenerated cochleae. Lesions, restricted to the Corti's organ and spiral ganglion, were bilateral but sometimes slightly asymmetrical. Mild to severe lesions of the Corti's organ were unevenly distributed among the different parts of the middle and basal cochlear turns while the apical turn remained unaffected at 148 days. In 82 day-old puppies (n = 2), severe lesions of the Corti's organ, meaning that it was replaced by a layer of unidentifiable cells, involved the lower middle and upper basal turns junction area, extending in the upper basal turn. Mild lesions of the Corti's organ, with both hair and supporting cells abnormalities, involved the lower middle turn and extended from the rest of upper basal turn into the lower basal turn. The outer hair cells (ohc) were more affected than the inner hair cell (ihc). The lesions extended towards the basal end of the cochlea in the 131 (n = 5) and 148 (n = 3) day-old puppies. Additionally, the number of spiral ganglion neurons was reduced in the 131 and 148 day-old puppies; it is earlier than observed in most other canine hereditary deafness. These lesions were interpreted as a degeneration of the neuroepithelial type. This possible animal model might provide information about progressive juvenile hereditary deafness and neuronal retrograde degeneration investigations in human.

Coexpression of IL-2 receptor p55 and p75 by circulating blood lymphocytes.

By using high-sensitivity fluorescence and flow cytometry, it is possible to show that 30-40% of lymphocytes from PBL express the p55 chain of the IL-2 receptor, whereas the p75 chain is expressed at low concentrations on most lymphocytes without in vitro activation. The availability of a second fluorochrome capable of high sensitivity allows simultaneous analysis of p55 and p75, albeit with some sacrifice in sensitivity. Two-color analysis shows that a small proportion of cells (1-6%) coexpress measurable concentrations of both chains of the IL-2 receptor, and three-color studies show that these cells are predominantly CD4-positive T cells and express the CD45R0 isoform of the leucocyte-common antigen, i.e., have the phenotype of activated helper T cells. These cells may be a useful indicator of immune activation.