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PubMed2003

Efficacy of antimicrobial filter treatments on microbial colonization of air panel filters.

AIMS: To assess the activity of biostatic agents on the microbial colonization of panel filters. METHODS AND RESULTS: Microfibre glass acrylic filters, both used and unused, were examined for the presence of microorganisms. Test strains were used to verify microbial colonization of filter media. Antimicrobial agents were applied to the filter media and tested for their ability to reduce microbial colonization. The integrity of the panel filters and the antimicrobial activity trends of the filter media treated with antimicrobials were verified. A filtration efficiency test was carried out on the treated filters to evaluate filtration performance. Filters treated with antimicrobials demonstrated markedly less microbial colonization (density and varieties of species), higher filtration efficiency and delayed deterioration of the filter. CONCLUSIONS: The most important results of this study are the demonstration of preservation of the integrity of the filters and the lower release of microorganisms from treated filters. SIGNIFICANCE AND IMPACT OF THE STUDY: These results contribute to the resolution of problems concerning the microbial contamination of panel filters in the heating, ventilating and air-conditioning systems commonly used in the electronic industry, pharmaceutical industry, hospitals and other environments where the absence of contaminating particles and microorganisms is required.

Air Conditioning↗
PubMed2004

Indoor air climate requirements for Russian churches and cathedrals.

UNLABELLED: In the article a verification of indoor climate requirements for Russian churches and cathedrals and recommendations on maintenance are given. From the point of view of building physics and longevity of building materials, frescos, icons, wood, paper, leather, parchment and natural textiles are regarded as capillary-porous physical bodies partly filled with moisture which includes dissolved salts. Porosity can be divided into three groups: large, moderate and small. What happens with these physical bodies when the indoor temperature and humidity changes is that deformation occurs and this may lead to breakage. Research to determine the dependence of deformation on the humidity of the surrounding structural materials of the cathedrals was carried out by a holographic interferometer. Diagrams of humidity and temperature deformation show the following results: the graphics of humidity and temperature are alike, the temperature deformations are not extensive, deformation due to humidity is more serious than deformation caused by temperature. The investigations of temperature and humidity deformation made it possible to give recommendations for the level of indoor air temperature and humidity in cathedrals. On the basis of these investigations, the Russian standard "Orthodox temples. Heating, ventilation, air conditioning" was developed (ABOK, 2002). PRACTICAL IMPLICATIONS: Temperature and humidity changes can affect building materials and the building structure. In the case of Russian cathedrals and churches, traditional artefacts are also affected.

Air Conditioning↗
PubMed1987

Nosocomial legionellosis associated with use of oxygen bubble humidifiers and underwater chest drains.

In 1 year 12 of 48 patients who developed fatal pneumonia following admission with non-respiratory disorders to the Hospital Molinette, Torino, yielded Legionella pneumophila serogroup 1 from lung at autopsy. Patients were hospitalized on seven different wards for different conditions; only two of the wards had air conditioning but legionellas were not isolated from these. All patients were in poor health or immunocompromised. Some patients had inhaled humidified oxygen from piped supplies and three had undergone surgery. Legionella pneumophila serogroup 1 was detected in the water of oxygen bubble humidifiers and an underwater chest drain. The contaminated devices had been filled with tap or distilled water and the hospital water supply was found to be contaminated with L. pneumophila serogroup 1. Our findings suggest that filling bubble humidifiers or underwater chest drains with tap water is a potential hazard and should be avoided.

Cross Infection↗
PubMed2006

Saliva as a viable alternative source of human genomic DNA in genetic epidemiology.

BACKGROUND: Saliva is a potentially useful but untapped source of genomic DNA for genetic epidemiological studies. However, current commercial methods are mainly concerned with DNA extraction and do not address important issues concerning saliva preservation and storage. As such, we evaluated how various saliva storage conditions affected DNA yield and quality obtained using a new commercially available method that proposes to integrate these aspects in a single kit. METHODS: The conditions involved the extraction of the DNA immediately after saliva collection (condition 1) or when stored at air-conditioned room temperature (20 degrees C) for 1 month (condition 2) and 6 months (condition 3) as well as at -80 degrees C for 6 months (condition 4). The effect of incorporating an additional incubation of saliva samples at 30 degrees C for 2 weeks was also examined. RESULTS: Overall average DNA yield from 2 ml of saliva was 35.5 microg (8.5-85.2 microg). DNA yield was unaffected by incubation of saliva at 30 degrees C but DNA yield under condition 3 was significantly higher compared to conditions 1 and 2. OD260/280 values were acceptable and comparable across all conditions. Differences in storage conditions did not impact DNA quality in real time PCR experiments and genotyping fidelity remained undiminished. CONCLUSION: Saliva is a viable alternative source of human genomic DNA for genetic epidemiological studies and that this new commercial method and possibly other related techniques can be effective means towards this end.

DNA↗
PubMed1998

Cloning and characterization of high-CO2-specific cDNAs from a marine microalga, Chlorococcum littorale, and effect of CO2 concentration and iron deficiency on the gene expression.

Two cDNA clones exclusively induced under an extremely high-CO2 concentration (20%) were isolated from Chlorococcum littorale by differential screening and named HCR (high-CO2 response) 1 and 2, respectively. The amino acid sequence of the protein encoded by HCR2 exhibited homology to the gp91-phox protein, a critical component of a human phagocyte oxidoreductase, and to the yeast ferric reductases, Saccharomyces cerevisiae FRE1 and FRE2 and Schizosaccharomyces pombe Frp1. The induction of both HCR mRNAs required extremely high-CO2 conditions and iron deficiency, being suppressed under air conditions and by iron sufficiency, suggesting that the expression of these two HCR genes required extremely high-CO2 conditions and iron deficiency in combination. The HCR2 protein was detected in the membrane fractions of cells grown under conditions which would favor the induction of HCR2-mRNA and the protein level was lowered when the cells were transferred from iron deficient to 10 microM FeSO4 conditions (with 20% CO2).

Algal Proteins↗
PubMed1985

Dry air-induced constriction in lung periphery: a canine model of exercise-induced asthma.

We studied the effects of the flow of dry air on collateral tone in the lung periphery. A bronchoscope was wedged in sublobar segments of anesthetized dogs, and measurements of collateral resistance (Rcs) were recorded before and after flow was increased from 200 to 2,000 ml/min for a 5-min period. Five minutes after exposure was completed, Rcs increased by an average of 117 +/- 25.2% (SE) over control. Maximum Rcs occurred 5 min after the challenge was concluded and required 48 +/- 10.5 min to return to base line. When flow rate was held constant and exposure period varied, Rcs increased with increased stimulus duration. With exposure times held constant, the response of the collateral system was positively associated with changes in stimulus strength (flow rate). No refractory period was observed with repetitive challenges. Finally, when dry air (delivered at 22 degrees C) and conditioned air (i.e., delivered at 28 degrees C; relative humidity = 80%) challenges were alternated in the same wedged segment, dry air produced a mean increase in Rcs of 93.2%, whereas challenge with warm moist air increased Rcs only 33.5%. Regardless of which challenge was presented first, dry air consistently produced a greater constrictor response. This response is similar to that observed in cold air- and exercise-induced asthma and indicates that the lung periphery in dogs, like larger airways in asthmatic subjects, has the potential to increase tone when exposed to dry air. Peripheral airways in dogs thus constitute a model that can be used for the investigation of exercise-induced asthma.

Air↗
PubMed1991

Seasonal changes in the in-vivo activity of the luteinizing hormone-releasing hormone (LHRH) neural apparatus of male rabbits monitored with push-pull cannulae.

Intact sexually mature New Zealand White male rabbits, raised under natural lighting and temperature conditions, were isolated and housed in air-conditioned quarters, in a 12-h light:12-h dark cycle. Push-pull cannulae were implanted towards the tuberal region of the hypothalamus, and animals were perfused with modified Krebs'-Ringer phosphate medium for an average period of 4 h. Most rabbits were repetitively perfused over an average period of 3.7 months. Perfusions were grouped into seasonal periods of about 40 or 80 days through the entire 1-year cycle: (A) 23 November to 31 December (winter solstice period: N = 6), (B) 1 January to 23 March (winter: N = 10), (C) 24 March to 13 June (spring: N = 9), (D) 14 June to 23 July (summer solstice period: N = 23), (E) 24 July to 13 October (late summer-early fall: N = 7) and (F) 14 October to 22 November (fall: N = 4). Maximal and minimal values of mean release, mean amplitude and mean frequency from every animal in each block were obtained. In the summer solstice group (D), maximal mean (+/- s.e.) LHRH release levels were significantly greater (14.42 +/- 6.62 pg/10 min) than for all groups (A, 0.76 +/- 0.27; B, 1.59 +/- 0.39; C, 1.34 +/- 0.22; E, 1.33 +/- 0.33; and F, 1.18 +/- 0.11) while during the winter solstice period (A), minimal mean LHRH release levels (0.48 +/- 0.04 pg/10 min) were significantly lower than in all other groups (B, 1.43 +/- 0.41; C, 0.96 +/- 0.11; D, 7.25 +/- 4.12; E, 1.18 +/- 0.37; and F, 1.18 +/- 0.11). Maximal values were highest during the summer solstice period while the minimal values were lowest during the winter solstice period. The amplitude and frequency of the LHRH pulses showed changes similar to those observed with the mean LHRH release. For 1 year, an estimated left testis weight was measured in 4-7 rabbits every 2-5 weeks. The percentage estimated testis weight peaked in early August and reached minimal levels during the winter months. These data demonstrate that the rabbit LHRH neural apparatus is very sensitive to seasonal influences although animals remained in a fixed photoperiod during the entire duration of the experiment.

Animals↗
PubMed1995

[Halothane concentration inhaled by anesthesiologists during anesthesia through face masks].

Exposure to low concentrations of anesthetics is still an important medical concern. We measured halothane concentrations in air inspired by anesthesiologists practicing inhalational anesthesia through face masks (10 cases, 200 sampling points). Halothane concentrations were 0 to 15 ppm (mean 4.89 ppm), higher than the safety level recommended by National Institute for Occupational Safety and Health (NISOH). However, these concentrations were clearly low in a room air-conditioned with vertical laminar flow providing total air exchange rate of 30 per hour (0.55 +/- 0.53 ppm, n = 40) compared to those in the rooms with horizontal laminar flow of 25 (5.98 +/- 3.80 ppm, n = 80, P < 0.001). These observations indicate the importance of ventilation systems of operating rooms for avoiding anesthetic gas exposure to anesthesiologists during inhalational anesthesia through face masks.

Anesthesia, Inhalation↗
PubMed1992

[Health status and prevention of disorders in people performing intensive visual work].

Electronic industry workers, whose work involves visual strain were examined. The work appeared to be characterized by a plenty of unfavourable factors: high visual and emotional intensity, considerable strain of the locomotor apparatus in supporting a fixed sitting posture. The micromountain workers were exposed to poor ionized and ozonized air conditions combined with high bacterial contamination and lack of the UV rays in the air. Examinees showed markedly changed health and functional status of the main body systems. A complex of hygienic, prophylactic, physiological, technological and medical measures yielded remarkable results. Working conditions of electron industry workers are to be regulated.

Adult↗
PubMed1996

Heat-related deaths during the July 1995 heat wave in Chicago.

BACKGROUND: During a record-setting heat wave in Chicago in July 1995, there were at least 700 excess deaths, most of which were classified as heat-related. We sought to determine who was at greatest risk for heat-related death. METHODS: We conducted a case-control study in Chicago to identify risk factors associated with heat-related death and death from cardiovascular causes from July 14 through July 17, 1995. Beginning on July 21, we interviewed 339 relatives, neighbors, or friends of those who died and 339 controls matched to the case subjects according to neighborhood and age. RESULTS: The risk of heat-related death was increased for people with known medical problems who were confined to bed (odds ratio as compared with those who were not confined to bed, 5.5) or who were unable to care for themselves (odds ratio, 4.1). Also at increased risk were those who did not leave home each day (odds ratio, 6.7), who lived alone (odds ratio, 2.3), or who lived on the top floor of a building (odds ratio, 4.7). Having social contacts such as group activities or friends in the area was protective. In a multivariate analysis, the strongest risk factors for heat-related death were being confined to bed (odds ratio, 8.2) and living alone (odds ratio, 2.3); the risk of death was reduced for people with working air conditioners (odds ratio, 0.3) and those with access to transportation (odds ratio, 0.3). Deaths classified as due to cardiovascular causes had risk factors similar to those for heat-related death. CONCLUSIONS: In this study of the 1995 Chicago heat wave, those at greatest risk of dying from the heat were people with medical illnesses who were socially isolated and did not have access to air conditioning. In future heat emergencies, interventions directed to such persons should reduce deaths related to the heat.

Aged↗
PubMed2000

[A boy with summer onset paroxysmal cold hemoglobinuria induced by Donath-Landsteiner antibody with anti-I specificity].

We encountered 4-year-old boy who developed paroxysmal cold hemoglobinuria (PCH) in the middle of August. He was admitted due to progressive jaundice and pallor following fever and nausea. Laboratory data revealed severe anemia, increased serum indirect bilirubin and LDH, and decreased serum haptoglobin. Direct/indirect Coombs tests were positive. These findings yielded a diagnosis of autoimmune hemolytic anemia. Serological test for syphilis was negative. The patient's symptoms and signs promptly subsided after treatment with prednisolone, which was started on the 2nd hospital day. The patient has been in a disease-free state for 16 months without any medication. After discharge, he was finally given a diagnosis of PCH because a Donath-Landsteiner test was positive. The antibody belonged to an IgM subclass and showed anti-I specificity. Considering that development of PCH is common in winter, this case was unique because it developed in August. We speculated that exposure to a cool air-conditioned atmosphere prior to hospitalization and the cooling mechanism of the body after admission were involved in the summer onset of PCH and its prolonged clinical course.

Air Conditioning↗
PubMed1988

Comparison of intraairway temperatures in normal and asthmatic subjects after hyperpnea with hot, cold, and ambient air.

To determine how the inhalation of hot dry, frigid, and room temperature air influences airway heat transfers, we obtained single-breath temperature washout curves in eight asthmatic and eight normal subjects before and during periods of hyperpnea. The order of study was randomly determined, and the thermal events with each inspirate were correlated with their effects on lung function. Each inspired air condition produced significant airway cooling in both groups. Cold air evoked the greatest response, followed thereafter by hot dry and then room air. Only the asthmatic subjects developed airway obstruction. These data demonstrate that hot dry gases facilitate evaporative cooling and do not keep the airways warm as has been previously suggested. It appears the airway cooling is a normal part of respiration and develops whenever air is inhaled that requires the transfer of heat and/or water to bring the inspirate to body conditions.

Adult↗
PubMed2002

Dermatitis caused by physical irritants.

BACKGROUND: Although physical irritant contact dermatitis (PICD) is a common occupational dermatosis, it is one of the least well understood because of its multiple types, lack of diagnostic test, and the many mechanisms involved in its production. OBJECTIVES: To characterize the materials and mechanisms of physical irritation of the skin. METHODS: We did a retrospective analysis over the past 20 years of all patients with a diagnosis of PICD at St John's Institute of Dermatology Contact Dermatitis Clinic. RESULTS: Of the 29,000 patients who attended the clinic over the study period, 392 patients were diagnosed with PICD and of these, 335 files were analysed. CONCLUSIONS: Our findings show that PICD accounted for 1.15% of all patients attending the contact clinic over the study period. Diverse occupations and materials were implicated. The most common cause of PICD was low humidity due to air-conditioning, which caused dermatitis of the face and neck in office workers due to drying out of the skin.

Adolescent↗
PubMed1979

The Vermont epidemic of Legionnaires' disease.

Sixty-nine laboratory-documented cases of Legionnaires' disease occurred in Vermont between 1 May and 31 December 1977. Clinical manifestations were similar to those in the 1976 Philadelphia epidemic. Case-control studies suggested that Legionnaires' disease patients were more likely to present with headache or diarrhea than were patients with pneumonia of presumed nonbacterial cause. The case-fatality ratio for patients treated with erythromycin was 4%, compared with 17% in patients not treated with erythromycin. Thirteen patients had been hospitalized throughout the 10 days preceding onset of illness, equaling the maximal known incubation period. This suggests either acquisition or reactivation of infection in the hospital. However, even during the week of peak disease activity, cases occurred in patients with no recent hospital contact. The only community factor possibly associated with acquisition was home air conditioning. This prevalence of seroreactivity to the Legionnaires' disease bacterium in various community populations was as high as 26%, suggesting a possible endemic area.

Adolescent↗
PubMedDate not supplied

The effect of an 18-hour electrical power outage on an urban emergency medical services system.

OBJECTIVES: To describe the experience of an urban, commercial ambulance provider during the multistate August 2003 electrical power outage (EPO) and to identify how such an event can affect an emergency medical services (EMS) system. METHODS: Data were abstracted from all dispatch and prehospital medical records generated during the 18-hour EPO. An hour-by-hour comparison was made between the median number of hourly EMS dispatches during the month of August 2003 and the total number of hourly EMS dispatches during the EPO. Presenting complaints were categorized, and all calls related to the EPO were identified. RESULTS: During the first ten hours of the EPO, hourly call volume increased an average of 250% (range 50%-500%) as compared with all of August 2003. The greatest increase in call volume occurred during the first seven hours of the EPO. During the EPO, 16% (n = 13) of patients presented with a heat-related complaint precipitated by the failure of air conditioning. In the same period, 37% (n = 31) of patients presented with a respiratory-related complaint, 52% (n = 16) of which were precipitated by the failure of home respiratory equipment such as ventilators, nebulizers, and oxygen concentrators. During the EPO, the average time spent on scene with patients increased 63%, from 11 to 18 minutes, when compared with the time spent 16 hours immediately prior and 14 hours immediately after the EPO. Average response and transport times did not change. CONCLUSION: Loss of power can cause a dramatic but short-term increase in call volume and lead to a disaster-like situation. EMS resources may be conserved by proactively assisting patients with home medical devices before they develop emergent conditions. Such a patient population might benefit, for example, from home deliveries of portable oxygen tanks or from the creation of temporary facilities that provide a climate-controlled environment and electrically powered medical devices.

Air Conditioning↗
PubMed1992

Temperature and humidity control system in a lunar base.

An increasing number of lunar base construction programs are in the process of developing lunar resources such as helium 3. The objective of the present work is to evaluate the temperature and humidity control system, which will allow man to live and work on the moon while developing lunar resources. The results of thermal load calculation show that the load of electric lighting is a 80 to 90% of the cooling load in the habitat module and that only the cooling function is required for temperature control. Due to this, a fluorocarbon refrigerant heat pump system was selected to satisfy reliability, energy consumption, size and weight requirements for the lunar base equipment. According to the load calculation, occupants will feel discomfort due to radiant heat from lighting fixtures. To resolve this problem, an air conditioning system, used in combination with forced convective cooling and panel cooling on the ceiling, was adopted in the living space. Moreover, the experiment on the ground was carried out to evaluate the effects of panel cooling.

Air Conditioning↗
PubMed1991

Isolation of Legionella pneumophila from patients of respiratory tract disease & environmental samples.

In this preliminary study 45 patients suffering from pneumonia were screened for L. pneumophila. Also 17 random environmental samples viz., water from cooling system used for air-conditioning units and samples from respirator-humidifier were screened. Four of 45 (9%) clinical specimens and 13 of 17 (76%) environmental samples showed presence of L. pneumophila. This is the first report from India of the isolation on L. pneumophila.

Air Conditioning↗
PubMed1980

Exclusion of particulate allergens by window air conditioners.

Effects of window air-conditioner operation on intramural particle levels were assessed in the bedrooms of 20 homes and in 10 outpatient clinic examining rooms during late summer periods. At each site, pollen and spore collections in the mechanically cooled room and a normally ventilated counterpart were compared using volumetric impactors. Substantially lower particle recoveries (median = 16/m3) were found in air-conditioned rooms than in those with open windows alone (median = 253 particles/m3). Furthermore, substantial exclusion of small (e.g., Ganoderma spores) as well as large (ragweed pollens) aerosol components were found by window units. Control studies within normally ventilated rooms and outside their open windows showed a marked but variable inward flux of particles. Window units appear to substantially reduce indoor allergan levels by maintaining the isolation of enclosed spaces from particle-bearing outdoor air.

Air Conditioning↗