The SLICK haplotype (http://omia.angis.org.au/OMIA001372/9913/) in cattle confers animals with a short and sleek hair coat. Originally identified in Senepol cattle, the gene has been introduced into Holsteins. The objectives of the current study were to determine (1) whether lactating Holsteins with the slick hair phenotype have superior ability for thermoregulation compared with wild-type cows or relatives not inheriting the SLICK haplotype, and (2) whether seasonal depression in milk yield would be reduced in SLICK cows. In experiment 1, diurnal variation in vaginal temperature in the summer was monitored for cows housed in a freestall barn with fans and sprinklers. Vaginal temperatures were lower in slick-haired cows than in relatives and wild-type cows. In experiment 2, acute responses to heat stress were monitored after cows were moved to a dry lot in which the only heat abatement was shade cloth. The increases in rectal temperature and respiration rate caused by heat stress during the day were lower for slick cows than for relatives or wild-type cows. Moreover, sweating rate was higher for slick cows than for cows of the other 2 types. In experiment 3, effects of season of calving (summer vs. winter) on milk yield and composition were determined. Compared with milk yield of cows calving in winter, milk yield during the first 90 d in milk was lower for cows calving in the summer. However, this reduction was less pronounced for slick cows than for wild-type cows. In conclusion, Holsteins with slick hair have superior thermoregulatory ability compared with non-slick animals and experience a less drastic depression in milk yield during the summer.

Advanced actuarial techniques are used to analyze late results in 912 patients who had isolated mitral or aortic valve replacement with ball valve prostheses from 1965 to 1974. Experience with noncloth-covered and cloth-covered valves is compared in terms of late survival, rate of thromboembolic complications and reoperation and the influence of anticoagulation. The cloth-covered prostheses have substantially reduced the incidence of emboli after mitral valve replacement (1.9 vs. 6 emboli per 100 patient years) and have thus far eliminated emboli after aortic valve replacement in patients receiving warfarin. Patients with a cloth-covered aortic valve who did not receive warfarin had nine emboli per 100 patient years. The safety of cloth-covered valves is clearly enhanced by warfarin therapy; the efficacy of anti-platelet drugs is still uncertain. Strut cloth wear was found at reoperation in 10 patients. This should be prevented in the new model 2400 composite strut ("track") valve by a narrow metal track on the inner surface of each strut. The substantial recent reductions in operative mortality and in prosthesis-related complications pose important questions regarding timing of operations and selection of prostheses. These decisions must be individualized for each patient on the basis of a thorough analysis of late results using modern statistical methods.

Coronavirus Disease 2019 (COVID-19) may spread through respiratory droplets released by infected individuals during coughing, sneezing, or speaking. Given the limited supply of professional respirators and face masks, the U.S. Centers for Disease Control and Prevention (CDC) has recommended home-made cloth face coverings for use by the general public. While there have been several studies on aerosol filtration performance of household fabrics, their effectiveness at blocking larger droplets has not been investigated. Here, we ascertained the performance of 11 common household fabrics at blocking large, high-velocity droplets, using a commercial medical mask as a benchmark. We also assessed the breathability (air permeability), texture, fiber composition, and water absorption properties of the fabrics. We found that most fabrics have substantial blocking efficiency (median values >70%). In particular, two layers of highly permeable fabric, such as T-shirt cloth, blocks droplets with an efficiency (>94%) similar to that of medical masks, while being approximately twice as breathable. The first layer allows about 17% of the droplet volume to transmit, but it significantly reduces their velocity. This allows the second layer to trap the transmitted droplets resulting in high blocking efficacy. Overall, our study suggests that cloth face coverings, especially with multiple layers, may help reduce droplet transmission of respiratory infections. Furthermore, face coverings made from materials such as cotton fabrics allow washing and reusing, and can help reduce the adverse environmental effects of widespread use of commercial disposable and non-biodegradable facemasks.

Keywords: Breathability; COVID-19; Cloth face covering; Droplet blocking; Face mask; Respiratory droplets; SARS-CoV-2.

BACKGROUND

There is evidence that human beings are familiar with use of animals for food, cloth, medicine, etc. since ancient times. Enormous work has been done on ethnobotany and traditional medicine. Like plants, animal and their products are also possessing medicinal properties that can be exploited for the benefit of human beings. In India, many ethnic communities are dispersed all over the country and these people are still totally depended on local traditional medicinal system for their health care. India is gifted with faunal and floral biodiversity, Mount Abu wildlife sanctuary is also one of them, and thus the aim of this work was to take an ethnozoological field survey among Garasiya people (main tribal group of this area) in the adjoining areas of this sanctuary.

METHODS

In order to document the ethnozoological information about animal and their products prevalent among these people in the adjoining area of Mount Abu wildlife sanctuary, a study was carried out from January, 2008 to April, 2008. Data were collected through semi-structured questionnaire and open interview with 25 (16 male and 9 female) selected Garasiya people. The name of animal and other ethnozoological information were documented. Photographs and discussion were also recorded with the help of camera and voice recorder.

RESULTS

A total of 24 animal species were used in 35 different medicinal purposes including asthma, weakness, tuberculosis, cough, paralysis and blister and for other religious purposes. It has been find out that animal used by Garasiya, consist of fourteen mammals, five birds, three reptiles, one arthropods and one amphibian. The meat of Cynopterus sphinx used to relieved fever and cough has the highest FL (96%) although flesh of Sus scrofa and tooth of Elephas maximus have the lowest FL (12%). Some protected species such as Elephas maximus (elephant), Semnopithecus priam (monkey), Cervus unicolor (sambhar) were also mentioned as important medicinal resources. We also found that cough, asthma and other respiratory diseases are the most frequently cited disease, as such, a number of traditional medicine are available for the treatment.

CONCLUSIONS

The present work indicates that 24 animal species were being used to treat 34 various ailments in the surroundings areas of Mount Abu wildlife sanctuary. The results show that ethnozoological practices are an important alternative medicinal practice for the Garasiya people. This study also indicates the very rich ethnozoological knowledge of these people in relation to traditional medicine. So there is an urgent need to properly document to keep a record of the ethnozoological information. We hope that this information will be useful for further research in the field of ethnozoology, ethnopharmacology and conservation point of view.

Introduction Many countries including Pakistan are currently using face masks in their pandemic control plans. Being highly prevalent, the correct use of these masks is particularly important, as an incorrect use and disposal may actually increase the rate of transmission. The purpose of this study was to investigate the knowledge, attitude, and practices of healthcare workers (HCWs) in wearing a surgical face mask to limit the spread of the new coronavirus disease 2019 (COVID-19). Materials and Methods This survey was conducted by interviewing HCWs using a questionnaire consisting of the basic demographic characteristics, and the knowledge, attitude, and practices regarding the use of surgical face mask to limit the new COVID-19 exposure. Each correct answer was scored 1 and each incorrect answer scored 0. The total number of questions was 16, and the final score was calculated and then labeled according to the percentage (out of 16) of correct responses as good (>80%), moderate (60-80%), and poor (<60%). Results A total of 392 participants with a mean age of 42.37 ± 13.34 years (341 males and 51 females) were included in the study. The overall final results were good in 138 (35.2%), moderate in 178 (45.4%), and poor in 76 (19.3%). Around 43.6% of participants knew about the correct method of wearing the masks, 68.9% knew that there are three layers, 53% stated that the middle layer act as a filter media barrier, and 75.5% knew the recommended maximum duration of wearing it. The majority (88.2%) of participants knew that a cloth face mask is not much effective, around 79.8% knew that used face mask cannot be re-used, and 44.8% knew about the yellow-coded bag for disposal. Conclusions Knowledge, attitude, and practice of HCWs regarding the use of face masks were found to be inadequate. Studied HCWs had a positive attitude but moderate-to-poor level of knowledge and practice regarding the use of face mask. HCWs and general public awareness campaigns regarding the proper use of face mask by utilizing all social media available resources would be helpful during this pandemic.

Keywords: coronavirus; covid-19; face mask; healthcare workers.

OBJECTIVE

To assess the impact of a school-based menstrual education programme on: (1) menstrual knowledge, beliefs and practices, (2) menstrual disorders experienced, and (3) restrictions on menstruating adolescents.

METHODS

Intervention study.

METHODS

Araihazar area, Bangladesh.

METHODS

416 adolescent female students aged 11-16 years, in grade 6-8, and living with their parents.

METHODS

A school-based health education study conducted from April 2012 to April 2013.

METHODS

We randomly selected 3 of 26 high schools in the study area. We delivered 6 months of educational intervention by trained (by an obstetrician and gynaecologist) research assistants (RAs) on menstrual hygiene among school girls. RAs read the questionnaire and participants answered. The changes in knowledge, beliefs and practices regarding menstruation, menstrual disorders experienced, and the restrictions and behaviours practiced by menstruating adolescents were compared between the baseline and the follow-up assessments.

RESULTS

After health education, participants reported a significant improvement (p<0.001) in 'high knowledge and beliefs' scores compared to baseline (51% vs 82.4%). Significant improvement was also observed in overall good menstrual practices (28.8% vs 88.9%), including improvements in using sanitary pads (22.4% change after the intervention), frequency of changing pads/cloths per day (68.8%), drying the used absorbent (77.6%), methods of disposing of the used absorbent (25.5%), and cleaning of genitalia (19.2%). During the follow-up, the participants reported significant improvements in the regularity of their menstrual cycle (94.5% vs 99.5%) and fewer complications during menstruation (78.6% vs 59.6%).

CONCLUSIONS

The programme produced significant changes in the knowledge, beliefs and practices of menstrual hygiene, complications from lack of hygiene, and the behaviour and restrictions of the menstruating adolescents. These results demonstrate the feasibility of implementing a health education programme for adolescents on menstrual hygiene in secondary schools serving rural Bangladesh.

The objective was to understand how the amount of shade (shade cloth blocking 99% of solar radiation) influenced the behavior and physiology of Holstein-Friesian dairy cattle managed on pasture. We compared behavior, body temperature, and respiration rate of cattle provided with 1 of 3 treatments for 5 d: access to 2.4m(2) or 9.6m(2) shade/cow, or no shade (n=4 groups/treatment, 10 animals/group). Behavioral observations were carried out between 1000 and 1550h. Cows spent more than twice as much time in the larger shade (24 vs. 50% of observations for 2.4m(2) and 9.6m(2) shade/cow, respectively, SED: 1.7%) and engaged in fewer aggressive interactions when more shade was provided (10.7 vs. 3.2 aggressive interactions/m(2) during 5.8h of observation for 2.4m(2) and 9.6m(2) shade/cow, respectively, SED: 3.16 interactions/m(2)). Time around the water trough increased when little or no shade was provided (11, 5, and 2% of observations within 4.5m of water trough for no shade, 2.4m(2), and 9.6m(2) shade/cow, SED: 2.4%). Respiration rate was higher when cows had less shade available (62, 57, and 51 breaths/min for no shade, 2.4m(2), and 9.6m(2) shade/cow, respectively, SED: 2.1 breaths/min). All cows used the shade more when 9.6m(2) shade/cow was provided; simultaneous use was observed in 15 versus 0% of observations in the 9.6m(2) and 2.4m(2) treatments on the warmest day, respectively. Weather conditions influenced both the behavioral and physiological responses, and these changes were more pronounced when less or no shade was available. Cows spent more time in shade and less time lying with increasing heat load. In addition, aggressive interactions in the shade, time around the water trough, mean body temperature, and respiration rate increased with environmental heat load. Our findings highlight the importance of determining and providing an effective amount of shade to cattle.

The seasonal temporal and spatial distribution and emergence of overwintering and summer cohorts of host-seeking American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae), adults were examined for 5 years in the Bluegrass region of Kentucky. Weekly drag cloth sampling was conducted from early March until late September 1992-1995 and early March until the end of May 1996. Overwintering adult cohorts became active in early to mid-April followed by bimodal host-seeking activity each year, with the duration and intensity of the first activity period being related to the previous year's summer cohort activity. The first activity peak extended from mid-April through late May and the second activity peak occurred in July. All host-seeking activity ceased by early August, except in 1995, when activity ended on 22 August. Laboratory survival of adults, collected weekly during 1993-1996, was used to estimate the emergence of summer adult cohorts. Summer adult cohorts became active in late May or early June and overlapped with overwintering adult host-seeking activity. The termination of host-seeking activity in overwintering adults could not be determined using the methods employed in this study and is most likely to have continued for the entire season. Host-seeking adults displayed contagious distribution patterns along trails bordering ecotone habitats, as determined by fitting a negative binomial frequency distribution to weekly sampling data. These patterns did not vary from year to year. In addition, the location of D. variabilis activity did not change from year to year, which suggests that microhabitats within apparently homogeneous environments enhance adult survival and lead to 'hot spots' of tick activity despite the ability of vertebrate hosts to disperse D. variabilis populations more widely. These data better define our understanding of D. variabilis adult seasonal and spatial host-seeking activity, estimate for the first time the intensity of summer cohort host-seeking activity, and relate summer cohort activity with spring activity the following year.

BACKGROUND

A total environmental cleaning system based on microfiber technology was implemented within 2 intensive care units (ICUs). The efficacy of this modified cleaning program was assessed using adenosine triphosphate (ATP) bioluminescence.

METHODS

A team of trained hygiene technicians cleaned all near-patient furniture and equipment twice a day using ultramicrofiber cloths. Every week for 40 weeks, 10 surfaces within a randomly selected bed area were sampled using the 3M Clean-Trace Clinical Hygiene Monitoring System (3M Health Care Ltd, Loughborough, United Kingdom). The ability of the modified cleaning program to reduce surface contamination to "acceptable" levels was measured against previously proposed benchmark ATP values.

RESULTS

In comparison with normal cleaning procedures routinely carried out by the nurses, the modified cleaning program significantly reduced (P < .001) the ATP readings obtained from surfaces within the near-patient environment. In both ICUs, 95% of surfaces sampled after modified cleaning had relative light unit values of <500 and were deemed "clean." Almost 90% of the surfaces could also be "passed" using the more stringent benchmark value of 250 relative light units. However, regardless of benchmark value used, the majority of surfaces sampled could also be considered adequately clean prior to them being cleaned by the hygiene technicians.

CONCLUSIONS

The use of ATP bioluminescence has been proposed as a means to improve the management of hospital cleaning. Use of benchmark values can help continually monitor the efficacy of existing cleaning programs. However, when evaluating novel or new cleaning practices, baseline cleanliness (ie, the level of cleanliness routinely achieved using normal cleaning procedures) must also be taken into consideration, or the efficacy of modified cleaning will be overestimated.

This was a cross-sectional study which aimed to determine associations between hematologic indices such as red blood cell cholinesterase (RBC) and mean corpuscular volume (MCV), with illnesses related to pesticide exposure among cutflower farmers in La Trinidad, Benguet. One hundred two (102) randomly selected cutflower farmers underwent comprehensive, personal physical health and laboratory examinations and answered a questionnaire on work practices and illness. Majority were males (52%) and most belonged to the 20-35 age group (45%). Majority of exposed farmers were symptomatic, with most common complaints being headache (48%), easy fatigability (46.1%) and cough (40.2%). Analysis showed that RBC cholinesterase levels were positively associated with age (p = 0.02), and selling pesticide containers (p = 0.008). number of years of using pesticides (p = 0.022), use of contaminated cloth (p = 0.033), incorrect mixing of pesticides (p = 0.041), sex (p = 0.002) and illness due to pesticides (p = 0.005) were correlated with abnormal MCV. Significant associations were also found for hemoglobin, hematocrit, RBC, white blood cell (WBC) and platelet count. Predictors of RBC cholinesterase were years of pesticide use (p = 0.037) and abnormalities on health (p = 0.029). The findings of the study can be used for information dissemination and pesticide reduction programs for the cutflower farmers.

Phosphate buffer solution has been commonly used in MFC studiesto maintain a suitable pH for electricity-generating bacteria and/or to increase the solution conductivity. However, addition of a high concentration of phosphate buffer in MFCs could be expensive, especially for wastewater treatment. In this study, the performances of MFCs with cloth electrode assemblies (CEA) were evaluated using bicarbonate buffer solutions. A maximum power density of 1550 W/m3 (2770 mW/ m2) was obtained at a current density of 0.99 mA/cm2 using a pH 9 bicarbonate buffer solution. Such a power density was 38.6% higher than that using a pH 7 phosphate buffer at the same concentration of 0.2 M. Based on the quantitative comparison of free proton transfer rates, diffusion rates of pH buffer species, and the current generated, a facilitated proton transfer mechanism was proposed for MFCs in the presence of the pH buffers. The excellent performance of MFCs using bicarbonate as pH buffer and proton carrier indicates that bicarbonate buffer could be served as a low-cost and effective pH buffer for practical applications, especially for wastewater treatment.

Squirrel monkeys were exposed to brief tail-pinches in the presence of a cloth-covered ball. Attack was elicited against the ball as a direct function of the force of the tail-pinch. This finding in conjunction with previous findings regarding electric shock and intense heat demonstrates that several types of aversive stimulation can elicit aggression.

In a control scheme for enzootic-pneumonia-free herds, run by the Pig Health Control Association, a detailed study was made of 55 herds that developed enzootic pneumonia without a simple explanation. These herds were compared with 57 herds that were still free from enzootic pneumonia in mid-1984. A high standard of precautions against the risk of infection being transferred by people and fomites seemed to confer no obvious benefit. This observation was in keeping with in vitro studies which showed that, although Mycoplasma hyopneumoniae could survive for a long time in favourable liquid medium, it could not be recovered from material such as cloth, once the culture had become dry. Under field conditions, the organism would probably cease to be infective within 48 hours. The organism survived particularly well in rain water at lower temperatures, however, and transmission via moist cold air seemed a possibility. There was a tendency for breakdowns to start in the autumn and winter, particularly in highly secure units, and several farmers associated colder misty conditions with the arrival of infection. One herd was probably infected by an imported boar and the very close proximity of foreign pigs, such as in slaughterhouse transport, seemed the most likely explanation in 15 other herds. One herd was replaced without this danger being attended to and it soon broke down again, whereas the three herds in this category that have survived after replacement all had this risk eliminated. Data was available on 37 of the 39 remaining herds to compare them with the 57 surviving herds, using a risk index based on the proximity of other pig units.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloth diapers, cellulose core diapers (conventional disposable diapers), and cellulose core diapers containing absorbent gelling material were examined for their effects on diaper rash and skin microbiology of normal infants and infants with atopic dermatitis in a 26-week double-blind clinical trial. Infants with atopic dermatitis wearing the diapers containing absorbent gelling material had significantly lower diaper rash grades than infants with atopic dermatitis wearing cloth diapers at five of eight grading visits. Infants with atopic dermatitis wearing conventional cellulose core diapers had statistically less rash at one of eight visits. There was no statistically significant difference between diaper types at three of the eight visits. At no time did the cloth group have less diaper rash than the conventional cellulose or absorbent gelling material disposable diaper group. A statistical correlation between the severity of general atopic dermatitis outside the diaper area and the diaper rash condition under the diaper occurred only in the atopic dermatitis group wearing cloth diapers. Isolation of microorganisms from the intact, uninvolved skin surface both inside and outside the diaper showed no biologically significant changes in the presence or numbers of selected skin organisms. Repeated isolation, at multiple grading visits of Staphylococcus aureus from uncompromised skin inside the diaper area was infrequent but correlated with the diagnosis of atopic dermatitis when observed.

In this study, the survival of Salmonella, Campylobacter and Escherichia coli O157: H7, when exposed to a range of constant temperatures (47-60 degrees C), in hard or soft water, in the presence/absence of detergent (0-0.3%) and organic matter, and during drying, was investigated. Further experiments used a washing-up process simulation, where soiled dishes contaminated with bacteria were washed in a bowl of warm water containing detergent. In addition, this study considered the risk of bacterial transfer onto (1) sterile dishes and sponges via contaminated water, (2) kitchen surfaces wiped with a contaminated sponge, (3) items placed in direct contact with a contaminated kitchen surface, (4) food placed on a contaminated dish or (5) dishes from contaminated food. A proportion of dishes remained contaminated with all pathogen types after a typical washing-up. Water hardness did not appear to affect survival. E. coli, and to a lesser extent Salmonella, survived towel- or air-drying on dishes and after towel-drying the cloth became contaminated on every occasion, regardless of the test organism. A proportion of sterile dishes washed after contaminated dishes became contaminated with pathogens but transfer from dishes onto food was rare. Washing-up sponges frequently became contaminated with pathogens. The results of this study highlight the potential for survival and cross contamination of food borne pathogens in the kitchen environment.

Groups of villagers, the care groups, are involved in prevention and treatment of trachoma within their own communities. The effect of the scheme on standards of hygiene and prevalence of trachoma has been evaluated by randomised cluster sampling methods. The number of households who were digging refuse pits, acquired individual face cloths and were aware of the role of good hygiene in the prevention of trachoma exceeded significantly those in (control) villages without a care group, in contrast the acquisition of pit latrines showed an insignificant increase. The prevalence and intensity of active trachoma was found to be significantly reduced as a result of the intervention of the care groups. This scheme has been totally integrated into the primary health care system of the area.

Cardiovascular and muscle load levels were evaluated during floor cleaning. A group of 12 experienced female cleaners participated in the study. Of the subjects 6 used a mopping method and 6 a traditional scrub and cloth method. Heart rate, oxygen consumption, rating of perceived exertion, electromyography from the trapezius muscle and video recordings were obtained during floor cleaning. With respect to relative heart rate and oxygen consumption the two groups did not differ. The results revealed a high cardiovascular load corresponding on average to 53 percent of the individual maximal oxygen uptake. In addition 65 percent of the observed period was spent with the back in a position forward flexed more than 20 degrees C. The time spent in extreme forward back flexion was shorter for the mopping group. Both groups exhibited high static, median and peak shoulder muscle load levels of 10 percent, 25 percent and 54 percent maximal voluntary contraction, respectively. At the same time, however, the mopping group tended to have a higher shoulder load than the group using the scrub and cloth method. Furthermore, electromyographic signs of fatigue in the trapezius muscle indicated a more stereotype activation of the shoulder muscles during mopping than during scrubbing. Based on these results, it was concluded that mopping cannot be recommended as less strenuous than scrubbing.

Disease detection in historical samples currently relies on DNA extraction and amplification, or immunoassays. These techniques only establish pathogen presence rather than active disease. We report the first use of shotgun proteomics to detect the protein expression profile of buccal swabs and cloth samples from two 500-year-old Andean mummies. The profile of one of the mummies is consistent with immune system response to severe pulmonary bacterial infection at the time of death. Presence of a probably pathogenic Mycobacterium sp. in one buccal swab was confirmed by DNA amplification, sequencing, and phylogenetic analyses. Our study provides positive evidence of active pathogenic infection in an ancient sample for the first time. The protocol introduced here is less susceptible to contamination than DNA-based or immunoassay-based studies. In scarce forensic samples, shotgun proteomics narrows the range of pathogens to detect using DNA assays, reducing cost. This analytical technique can be broadly applied for detecting infection in ancient samples to answer questions on the historical ecology of specific pathogens, as well as in medico-legal cases when active pathogenic infection is suspected.

OBJECTIVE

To describe 'dry sex' practices intended to decrease vaginal secretions and to determine whether these practices are related to HIV infection.

METHODS

A cross-sectional study was conducted in a sexually transmitted diseases clinic in a teaching hospital in Lusaka, Zambia. The subjects comprised 329 women aged 15-50 years presenting consecutively for an initial evaluation of sexually transmitted disease symptoms. Dry sex practices were assessed by questionnaire, and serological testing for HIV antibodies was performed.

RESULTS

Fifty percent of women had engaged in at least one dry sex practice. The most common practices were drinking 'porridge' (a liquid or suspension believed to cause drying of the vagina; 28%), removing vaginal secretions with a cloth (22%) and placing leaves in the vagina (11%). The most frequent reasons given for drinking porridge were to increase the partner's sexual enjoyment and to tighten the vagina, while cleaning the vagina was mentioned often by those using cloth or leaves. Swelling or peeling of the vagina was reported by approximately 10% of women using cloth or leaves. Overall, the HIV seroprevalence in the sample was 58%. In bivariate analysis, no practice was statistically significantly associated with HIV infection. Multiple logistic regression had little impact on these findings.

CONCLUSIONS

Although a variety of practices with potential relevance to HIV transmission were reported, there was no evidence in this study population of a strong relationship between these practices and HIV infection. Women should be counseled about the potential risks of these practices, but prevention efforts should continue to emphasize measures of known effectiveness, particularly limiting the numbers of sexual partners, consistently using condoms and obtaining appropriate treatment for sexually transmitted diseases.

Patients surviving a Fontan operation experience dramatic symptomatic improvement, but concern remains about the long-term results of this operation. The clinical course and postoperative hemodynamic findings in 5 long-term survivors of the Fontan procedure from our institution are presented. Attention is drawn to 3 patients who required reoperation: 1 immediately for residual mild pulmonary stenosis, 1 for late onset complete heart block, and 1 for conduit valve stenosis. Review of our patients and those described in the literature reveals that all have ascites and pleural effusions as a results of high venous pressures but that this is usually a temporary problem. Late onset of obstruction to right atrial emptying has been reported in several patients in addition to ours. This raises serious concerns about the long-term fate of cloth conduits and porcine valves in this application. Although normal sinus rhythm has been thought to be essential for adequate pulmonary perfusion in these patients, it is interesting that several patients have tolerated atrial tachyarrhythmias, junctional rhythms, and even complete heart block without serious ill effects. We conclude that the Fontan procedure is extremely effective in relieving symptoms at an operative risk that is now acceptable, but these patients require very careful long-term follow-up because they are subject to a number of long-term complications.

Films of human cytochrome P450 1A2 (cyt P450 1A2) and polystyrene sulfonate were constructed on carbon cloth electrodes using layer-by-layer alternate absorption and evaluated for electrochemical- and H(2)O(2)-driven enzyme-catalyzed oxidation of styrene to styrene oxide. At -0.6 V vs. saturated calomel reference electrode in an electrochemical cell, epoxidation of styrene was mediated by initial catalytic reduction of dioxygen to H(2)O(2) which activates the enzyme for the catalytic oxidation. Slightly larger turnover rates for cyt P450 1A2 were found for the electrolytic and H(2)O(2) (10 mM) driven reactions compared to conventional enzymatic reactions using cyt P450s, reductases, and electron donors for cytochromes P450 1A2. Cyt P450(cam) gave comparable turnover rates in film electrolysis and solution reactions. Results demonstrate that cyt P450 1A2 catalyzes styrene epoxidation faster than cyt P450(cam), and suggests the usefulness of this thin-film electrolytic method for relative turnover rate studies of cyt P450s.

Mutant clones of Chinese hamster ovary (CHO) cells defective in the base-exchange reaction of phospholipids with choline were isolated by using an in situ enzymatic assay for the reaction in cell colonies immobilized on polyester cloth. The specific activities of the choline-exchange reaction in extracts of one of the mutants (designated 64) grown at 33 degrees C and 40 degrees C were 13% and 6% of those in parental (CHO-K1) cells, respectively. The choline-exchange activity in the mutant was more thermolabile in cell extracts than that in the parent, suggesting that a mutation in the structural gene for the choline-exchange enzyme might have been induced in this mutant. In culture medium supplemented with lipoprotein-deficient serum, mutant 64 grew almost normally at 33 degrees C but divided only twice at 40 degrees C and then stopped growing. Labeling of intact cells with [32P]Pi showed that mutant 64 was also strikingly defective in the biosynthesis of phosphatidylserine at 40 degrees C but was normal at 33 degrees C. Most temperature-resistant revertants of mutant 64 exhibited nearly normal ability to synthesize phosphatidylserine at 40 degrees C and also showed choline-exchange activity similar to that in parental cells. The addition of phosphatidylserine to medium supplemented with newborn calf serum, in which mutant 64 grew more slowly than parental cells at 40 degrees C, restored the growth rate of the mutant to the parental level. Our findings suggest that the choline-exchange enzyme functions as the major route for the formation of phosphatidylserine and that the temperature-sensitive growth of mutant 64 is due to a defect in phosphatidylserine biosynthesis at 40 degrees C.

Although not laying claim to being the inventor of the light microscope, Antonj van Leeuwenhoek (1632-1723) was arguably the first person to bring this new technological wonder of the age properly to the attention of natural scientists interested in the study of living things (people we might now term 'biologists'). He was a Dutch draper with no formal scientific training. From using magnifying glasses to observe threads in cloth, he went on to develop over 500 simple single lens microscopes (Baker & Leeuwenhoek 1739 Phil. Trans. 41, 503-519. (doi:10.1098/rstl.1739.0085)) which he used to observe many different biological samples. He communicated his finding to the Royal Society in a series of letters (Leeuwenhoek 1800 The select works of Antony Van Leeuwenhoek, containing his microscopical discoveries in many of the works of nature, vol. 1) including the one republished in this edition of Open Biology. Our review here begins with the work of van Leeuwenhoek before summarizing the key developments over the last ca 300 years, which has seen the light microscope evolve from a simple single lens device of van Leeuwenhoek's day into an instrument capable of observing the dynamics of single biological molecules inside living cells, and to tracking every cell nucleus in the development of whole embryos and plants.

BACKGROUND

Most cases of human African trypanosomiasis (HAT) start with a bite from one of the subspecies of Glossina fuscipes. Tsetse use a range of olfactory and visual stimuli to locate their hosts and this response can be exploited to lure tsetse to insecticide-treated targets thereby reducing transmission. To provide a rational basis for cost-effective designs of target, we undertook studies to identify the optimal target colour.

RESULTS

On the Chamaunga islands of Lake Victoria , Kenya, studies were made of the numbers of G. fuscipes fuscipes attracted to targets consisting of a panel (25 cm square) of various coloured fabrics flanked by a panel (also 25 cm square) of fine black netting. Both panels were covered with an electrocuting grid to catch tsetse as they contacted the target. The reflectances of the 37 different-coloured cloth panels utilised in the study were measured spectrophotometrically. Catch was positively correlated with percentage reflectance at the blue (460 nm) wavelength and negatively correlated with reflectance at UV (360 nm) and green (520 nm) wavelengths. The best target was subjectively blue, with percentage reflectances of 3%, 29%, and 20% at 360 nm, 460 nm and 520 nm respectively. The worst target was also, subjectively, blue, but with high reflectances at UV (35% reflectance at 360 nm) wavelengths as well as blue (36% reflectance at 460 nm); the best low UV-reflecting blue caught 3× more tsetse than the high UV-reflecting blue.

CONCLUSIONS

Insecticide-treated targets to control G. f. fuscipes should be blue with low reflectance in both the UV and green bands of the spectrum. Targets that are subjectively blue will perform poorly if they also reflect UV strongly. The selection of fabrics for targets should be guided by spectral analysis of the cloth across both the spectrum visible to humans and the UV region.