Five cases of complications due to cloth wear in cloth-covered composite-seat Starr-Edwards aortic and mitral valvular prostheses are described. The complications of cloth wear were recurrent systemic emboli in three patients, two with aortic and one with mitral prosthesis, and severe hemolytic anemia in two patients with aortic prosthesis. The over-all incidence of clinically significant complications due to cloth wear in aortic and mitral valve prosthesis was 2.5 per cent. The diagnosis of cloth wear is impossible before reoperation and it was made by exclusion of other causes of recurrent transient cerebral ischemic attacks or systemic emboli and by exclusion of other causes of hemolytic anemia. Clinical and laboratory findings suggestive of cloth wear are described. Aggressive management of complications of cloth wear by reoperation is likely to prevent disabling or lethal consequences. Porcine xenograft aortic and mitral bioprostheses were used in these patients to replace the cloth-covered valvular prostheses. The symptoms due to cloth wear were abolished in all patients by reoperation, and all patients are off anticoagulants postoperatively. The operative mortality rate for reoperation in this small group of patients was zero.

BACKGROUND

Inadequate hand-washing facilities have been reported as a barrier to hand washing. This study aimed to evaluate the availability and accessibility of hand-washing facilities and supplies of hand-washing agents in the outpatient department (OPD) complex of a tertiary care teaching hospital.

METHODS

A checklist containing 13 variables was prepared and all rooms of direct patient care in the OPD were assessed on one occasion.

RESULTS

Out of 211 rooms surveyed, a hand-washing facility was available in 209 (99.05%) rooms. Among these, 206 (98.56%) sinks were easily accessible and were placed close to users. Almost all sinks (99.5%) had hand-operated taps. Thirty-five (16.75%) sinks had no soap stand, and at 21 (10.5%) sinks, soap stands were found to be broken. At 14 (6.70%) sinks, soap bars were not available, while an antiseptic agent was available at 6 (2.87%) sinks. Four (1.91%) sinks had no towel stand, and at 8 (3.83%) sinks the towel stands were broken. At 43 (20.57%) sinks no towel was available, and at 23 (11%) sinks the towels provided were dirty. No sink drain was found to be blocked. No sink had hand-washing instructions displayed demonstrating the correct technique of hand washing.

CONCLUSIONS

Physical facilities required for hand washing were adequate though not perfect. There is a need to shift from hand-operated taps to non-manual taps and from cloth towels to paper towels. Hospital managers in developing countries should continuously strive to provide the best possible hand-washing facilities within their financial resources.

Two new field bioassay methods were developed to compare the repellent activity of BioUD(®) (containing 7.75% 2-undecanone), 98.1% DEET and 0.5% permethrin against natural populations of nymphal Amblyomma americanum (L.) (Acari: Ixodidae). In a cloth sheet assay, pieces of material measuring 41 × 58 cm, separately treated with one of the test materials or the appropriate solvent carrier, were placed at random on the ground and baited with dry ice for 1 h. Mean numbers of ticks on repellent-treated sheets were significantly lower than on control sheets. There was no significant difference in the number of ticks collected between sheets treated with BioUD(®) and those treated with DEET. However, significantly fewer ticks were found on sheets treated with BioUD(®) or DEET than on permethrin-treated sheets. In a sock test, over-the-calf tube socks were treated with one of the test materials or the appropriate solvent carrier. Human volunteers wore a repellent-treated and a corresponding carrier-treated sock on either leg and walked randomly over an area of approximately 4000 m(2) for 15 min. Significantly fewer ticks were collected from socks treated with BioUD(®) or DEET than from socks treated with the carrier and there was no significant difference in repellency between these two agents. No difference in the mean number of ticks collected was found between permethrin-treated and corresponding carrier-treated socks. To examine the mechanism of repellency of BioUD(®) , a four-choice olfactometer was used to assess spatial repellency against adult A. americanum. As expected in the absence of a repellent, when all choices were represented by water-treated filter paper, ticks were equally distributed among the choices. When one choice consisted of BioUD(®) -treated filter paper and the remaining choices of water-treated paper, the distribution of ticks on the repellent-treated paper was significantly lower than might be expected to occur by chance, suggesting that repellency is at least partly achieved by an olfactory mechanism.

This work demonstrates that deltamethrin in low doses produces an excito-repellency effect on triatomines, as already observed for mosquitoes. A wooden box covered with a cloth impregnated with deltamethrin at doses of 2.5 and 5mg ai/m2 was utilized for the experiment. The triatomine species studied were Triatoma infestans, Panstrongylus megistus, Rhodnius neglectus and Triatoma sordida. Adults were released in one of the sides of the box and their position was noted in subsequent periods. The observations were realized on the day the cloth was impregnated and subsequently repeated at 30 and 60 days for T. sordida; on day 120, the remaining species were included. Insect mortality and attempts at flight from the box were also observed. Excito-repellency was evident for all species and doses up to day 120. The only species that attempted to fly was P. megistus. The excito-repellency effect may be considered as an additional advantage to the insecticide power, as it should be able to prevent the installation of new colonies by females that fly into the homes, and at the moment of the spraying, it should promote the flushing out of triatomines from the wall crevices and from other shelters.

Three groups of premises (butchers' shops, supermarkets and general dealers) which sell raw and cooked meats were compared. Salmonellas were not detected, but Escherichia coli, and to a lesser degree Staphylococcus aureus and Streptococcus faecalis, were widely distributed in all three groups of premises. Contamination of hands, towels and nail brushes was related to poor working practices. The presence of E. coli or Str. faecalis on slicing machines was associated with contamination of meat samples. A number of wiping cloths were heavily contaminated with E. coli, and many also contained Clostridium perfringens. Fewer premises provided written cleaning plans, and in many cases staff did not receive an adequate training in food hygiene. The use of disinfectants as part of the cleaning process did not necessarily reduce the level of bacterial contamination. In general there was poor correlation between microbiological results and a visual inspection made by an environmental health officer. The possible reasons for this finding are discussed.

Between 1967 and 1979, 411 patients underwent surgical treatment of isolated mitral stenosis at our institution. Open radical mitral commissurotomy was performed in 150 patients (1967-1978; mean follow-up, 46 months; range, 4 to 116 months). Mitral valve replacement using a porcine prosthesis was performed in 74 patients (1976-1979; mean follow-up, 23 months; range, 2 to 48 months). Mitral valve replacement with a cloth-covered Starr-Edwards prosthesis was performed in 187 patients (1967-1975; mean follow-up, 45 months; range, 2 to 106 months). Preoperative characteristics were similar in the three groups. The open commissurotomy and Starr-Edwards groups were followed up to 9 years and the porcine valve group up to 4 years, with 97% follow-up in each group. Life-table analysis (6-month intervals) of all postoperative complications revealed significantly greater complication-free survival for patients who had open radical commissurotomy compared with Starr-Edwards (p less than 0.05) valve replacement. Similar analysis of thromboembolic and warfarin-related complications revealed significantly fewer complications in commissurotomy patients. No significant differences were found (p greater than 0.05) when comparing the need for subsequent reoperation in each group. Operative mortality following open radical mitral commissurotomy (0%; 0 out of 150) was significantly less (p less than 0.05) than after mitral valve replacement in both porcine (8.1%; 6 out of 74) and Starr-Edwards (11.2%; 21 out out 187) groups. Life-table analysis of late cardiac-related mortality revealed a significantly greater cumulative survival rate for the commissurotomy versus the Starr-Edwards groups at all intervals from 12 to 108 months (100 versus 84 +/- 5%, p less than 0.05). No significant differences were noted between commissurotomy and porcine valve groups during the 4-year follow-up period (100 +/- 0% versus 96 +/- 3%, p greater than 0.05). Based on these findings, we conclude that when the anatomy is favorable, the surgical treatment of choice for isolated mitral stenosis is open radical mitral commissurotomy.

BACKGROUND

Governments, multinational organisations, and charities have commenced the distribution of sanitary products to address current deficits in girls' menstrual management. The few effectiveness studies conducted have focused on health and education outcomes but have failed to provide quantitative assessment of girls' preferences, experiences of absorbents, and comfort. Objectives of the study were, first, to quantitatively describe girls' experiences with, and ratings of reliability and acceptability of different menstrual absorbents. Second, to compare ratings of freely-provided reusable pads (AFRIpads) to other existing methods of menstrual management. Finally, to assess differences in self-reported freedom of activity during menses according to menstrual absorbent.

METHODS

Cross-sectional, secondary analysis of data from the final survey of a controlled trial of reusable sanitary padand puberty education provision was undertaken. Participants were 205 menstruating schoolgirls from eight schools in rural Uganda. 72 girls who reported using the intervention-provided reusable pads were compared to those using existing improvised methods (predominately new or old cloth).

RESULTS

Schoolgirls using reusable pads provided significantly higher ratings of perceived absorbent reliability across activities, less difficulties changing absorbents, and less disgust with cleaning absorbents. There were no significant differences in reports of outside garment soiling (OR 1.00 95%CI 0.51-1.99), or odour (0.84 95%CI 0.40-1.74) during the last menstrual period. When girls were asked if menstruation caused them to miss daily activities there were no differences between those using reusable pads and those using other existing methods. However, when asked about activities avoided during menstruation, those using reusable pads participated less in physical sports, working in the field, fetching water, and cooking.

CONCLUSIONS

Reusable pads were rated favourably. This translated into some benefits for self-reported involvement in daily activities, although reports of actual soiling and missing activities due to menstruation did not differ. More research is needed comparing the impact of menstrual absorbents on girls' daily activities, and validating outcome measures for menstrual management research.

A high-performance liquid chromatographic method was developed for trace analysis of complex air mixtures containing 2,6- and 2,4-toluenediisocyanates and related aminoisocyanates and diamines. The accuracy was tested at isocyanate concentrations of 2-1000 microg/m3 in air. The method is based on derivatization in the sampling step of isocyanate functions to corresponding urethane groups, with alkaline ethanol as the sampling and reacting medium. The derivatives formed, toluenediurethanes and tolueneaminourethanes, and unreacted diamines were detected by UV or electrochemically, the electrochemical detection being one order of magnitude more sensitive. Using an enrichment column, detection limits of ca. 0.05 pg/microl were obtained with electrochemical detection at a potential of 950 mV, which corresponds to air concentrations of 0.1 microg/m3 with 5 min sampling time at a rate of 11/min. The precision in the measurements were ca. 4% at concentrations of 6 microg/m3. A field measurement was performed concerning flame lamination of toluenediisocyanate-based polyurethane and cloth. Isocyanates, aminoisocyanates and diamines were found at air concentrations of 1-100 microg/m3.

A common method for sampling tick populations is flagging, which is a method of dragging a white cloth over a plant substrate for a fixed distance along a transect. Flagging over rough physical surfaces or using long subtransect lengths could lead to the underestimation of tick densities. Using estimates of the drop-off rates of adult Ixodes pacificus in flag sampling, optimal sampling schemes (the length and number of subtransects) were examined using the relationships between the tick drop-off rates (c), the tick density and distribution patterns and the roughness of the sampled plant substrate. It was found that the optimal number of subtransects and Lmax, the longest subtransect length which did not significantly underestimate the tick density from c, were affected by the tick density, substrate roughness and tick distribution pattern. This study also showed that the density and distribution of I. pacificus and Dermacentor occidentalis varied greatly over time in the populations sampled, while the Dermacentor variabilis densities were low and showed no significant changes over time. Both I. pacificus and D. occidentalis had clumped distributions along trails and these clumps were aggregated. However, the clump sizes (or individual clump areas) changed significantly over time because of density fluctuation or the movement of ticks. Finally, a positive association between the number of I. pacificus and D. occidentalis adults was observed from 2 m subtransect flag collections in March 1995; no relationship was found in 1994.

BACKGROUND

Coronary artery bypass grafting (CABG) without the heart lung machine has been possible for easily accessible targets such as the anterior descending or proximal right coronary. Until now technical difficulty in reaching lateral and inferior wall targets imposed significant barriers to multivessel off-pump grafting. To expand the potential for off-pump CABG the authors have devised new exposure and stabilization techniques suitable for all target vessels. In this report we relate our experience with these new techniques and demonstrate that multivessel coronary bypass can be safely performed without cardiopulmonary bypass (CPB).

METHODS

From February 8, 1993 to December 16, 1997 a total of 280 patients underwent myocardial revascularization on the beating heart via median sternotomy. Until May 20, 1997 only patients with high preoperative risk factors for CPB were considered for this approach (Group A; N = 122). After this date any patients with favorable anatomy were included (Group B; N = 158) and were subsequently compared with patients operated on using CPB during the same time interval (Group C; N = 114). In Group B patients lateral and/or inferior wall targets were exposed by means of 4 cloth slings (2 through the transverse sinus and 2 behind the inferior vena cava) and by positioning the patients in Trendelenburg with rightward rotation of the table. Regional stabilization of the target artery was obtained with a commercial stabilizing foot plate.

RESULTS

Thirty day hospital mortality was only 2 patients (1.6%) in Group A, 3 patients (1.9%) in Group B, and 3 patients (2.6%) in Group C (NS). Postoperative complications were low in both Group A and B. When Group B was compared with a similar cohort in whom CPB was used (Group C), there were statistically significant improvements in ICU and hospital stay demonstrated when CPB was not used (16.8+/-10.7 vs 26.3+/-38.6 hours respectively; p = 0.007, and 4.1+/-1.5 vs 5.5+/-2.4 days respectively, p<0.001). Angiographic followup was available for 78 patients in Groups A and B with a global patency rate (all grafts) of 98.6%, including a patency rate of 96.7% for 60 grafts to obtuse marginal branches of the circumflex).

CONCLUSIONS

Multivessel CABG without CPB is possible with results similar to those obtained with pump-oxygenator support using simple exposure and stabilization techniques.

In vitro studies established that neither cloth nor disposable diapers demonstrably contributed to the growth of Escherichia coli, Proteus vulgaris, Staphylococcus aureus, or Candida albicans when urine was present as a growth medium. In a clinical study of 166 children, the microbial skin flora of children with atopic dermatitis was compared with the flora of children with normal skin to determine the influence of diaper type. No biologically significant differences were detected between groups wearing disposable or cloth diapers in terms of frequency of isolation or log mean recovery of selected skin flora. Repeated isolation of S. aureus correlated with atopic dermatitis. The log mean recovery of S. aureus was higher in the atopic groups. The effects of each diaper type on skin microflora were equivalent in the normal and atopic populations.

BACKGROUND

Dyeing is an age-old process and forms an integral part of textile industries. Tying is a process by which a particular part of cloth is prevented from the process of dyeing. The skin diseases in workers engaged in the 'tie and dye' industry have not been extensively studied.

OBJECTIVE

To study the prevalence of contact dermatitis among workers engaged in the 'tie and dye' industries in and around Jodhpur (Western Rajasthan).

METHODS

One thousand three hundred workers engaged in 'tie and dye' work were evaluated for occupation-related dermatitis. Those with skin lesions were subjected to patch tests using 2% aqueous solution of the dyes and chemicals commonly used by them. These included direct dyes, VAT dyes, sulfur dyes and azo dyes. Fifty workers without skin lesions served as controls.

RESULTS

One hundred patients (7.69%) had dermatitis involving the exposed sites, mainly the hands and forearms. Eighty-one patients showed positive reactions to one or more dyes, most commonly Red RC base (azo dye), followed by naphthol.

CONCLUSIONS

Red RC base and naphthol were the commonest allergens in the 'tie and dye' industry.

A questionnaire and observational study was conducted to determine the problems associated with construction, design and hygiene methods used to maintain pit latrines in a high-density urban township in Malawi. The survey comprised 100 randomly selected households and the person responsible for the latrine maintenance was interviewed. Eighty-seven percent of householders used traditional latrines, 67% with earthen and 20% with concrete (i.e. sanitation platform, also known as San-plats) floors. A variety of makeshift squat-hole covers (e.g. iron sheets, rocks, cardboard) are used by those who cannot afford San-plats to reduce fly and odour problems. Most squat-hole covers were fouled with faecal matter and some presented risk of invasive injury due to sharp edges. Five households used ventilated improved latrines whilst the remaining eight per cent made use of their neighbour's latrine. Ownership of property, poverty and theft in the area significantly influenced the type and structural condition of the latrine. Walls, ceilings and doors of the superstructure comprised a mixture of miscellaneous materials (i.e. cardboard, paper, cloth, brick) making the hygienic upkeep of the latrine difficult. Cloth doors were often used for hand drying. Geographical location, such as rocky terrain with inadequate soil consolidation, and environmental conditions, such as heavy rains and floods, exacerbate structural defects. Coupled with the lack of attention afforded to the disposal of young children's faeces, wash-water and pit surcharging, the potential exists for widespread contamination of the surrounding environment and transmission of faecal-oral disease. More than half of the respondents stressed that they had not received any information regarding health education and hygienic maintenance of the latrine. As such, there is need for a hygiene education programme to promote awareness of appropriate sanitation and behavioural change. Cultural and religious factors were found not to influence latrine use.

Y-chromosome detection by way of fluorescence microscopy in biological materials has made sex determination possible in various areas of investigation. The present report describes the results of sex determination on hairs and blood stains. Significant differences were found between the Y-body count for female and male materials. In blind trials it was demonstrated that a reliable sex determination of hairs was possible for at least 27 weeks and of blood stains on cotton cloth and glass for 6 weeks. There were no false positive findings, but there was one male with a "female" blood smear count, who revealed an abnormally small fluorescent region on his Y-chromosome. The existence of such variants calls for caution when evaluating a low count.

Animals on farms may be a potential reservoir and environmental source of methicillin-resistant Staphylococcus aureus (MRSA). Expanded surveillance methods for animal-associated MRSA are needed. To develop an environmental sampling method and to determine the correlation between animal and environmental MRSA positivity in the farm setting, we sampled horses, cattle, and their local environments at several farms in the mid-Atlantic United States. We obtained nasal swabs from 13 racehorses at first visit, and 11 racehorses at the same farm eight weeks later. We also sampled 26 pleasure horses and 26 beef cattle from two additional farm sites. Sterilized electrostatic cloths were used to collect dry dust samples from environmental surfaces in proximity to animals; cloths were cultured using a broth enrichment protocol. We described isolates by genotype and antimicrobial susceptibility phenotype. None of the samples (nasal or environmental) were positive from the pleasure horse farm or the cattle farm. On the racehorse farm, 8/13 (61%) nasal and 5/7 (71%) environmental samples were positive for MRSA at the first visit. Isolates found were indistinguishable by pulsed-field gel electrophoresis (PFGE) genotype. We observed significant positive correlation between nasal carriage of MRSA in animals and our ability to isolate MRSA from dry surface samples of their local environments. The methods presented here may aid in surveillance efforts for equine and other animal MRSA. This study successfully applies existing MRSA surveillance methods for indoor, high animal density settings to outdoor and low-density farms.

BACKGROUND

Current literature has shown the mechanism of how indirect fractures occur but has not determined what factors increase the risks of such fractures. The objective of this study is thus to determine the effect of clothing and soft tissue thickness on the risk of indirect fracture formation.

METHODS

Twenty-five fresh red deer femora embedded in ballistic gelatine were shot with varying distances off their medial cortex with a 5.56 × 45 mm North Atlantic Treaty Organization (NATO) bullet while being filmed with a slow-motion video. We compared the effect of two different gelatine depths and the effect of denim cloth laid onto the impact surface of the moulds.

RESULTS

Bullet passage in thinner moulds failed to cause fracture because the bullet exited the mould before a large expanding temporary cavity was produced. Clothing dramatically altered the size and depth of the expanding cavity, as well as increased lateral pressures, resulting in more severe fractures with greater bullet distances from the bone that can cause fracture.

CONCLUSIONS

Clothing increases the risk of indirect fracture and results in larger, more superficial temporary cavities, with greater lateral pressures than are seen in unclothed specimens, resulting in more comminuted fractures. Greater tissue depth affords the 5.56 × 45 mm NATO a chance to yaw and thus develop an enlarging temporary cavity that is sufficient to cause fracture.

Streptokinase is an extracellular protein, extracted from certain strains of beta hemolytic streptococcus. It is a non-protease plasminogen activator that activates plasminogen to plasmin, the enzyme that degrades fibrin cloth through its specific lysine binding site; it is used therefore as a drug in thrombolytic therapy. The rate of bacterial growth and streptokinase production was studied in condition of excess glucose addition to culture media and its pH maintenance. The streptokinase product of the bacterial culture was preliminary extracted by salt precipitation and then purified by affinity chromatography on plasminogen substituted sepharose-4B in a condition that the plasminogen active site was protected from streptokinase-induced activation. The purity of streptokinase was confirmed by SDS-PAGE and its biological activity determined in a specific streptokinase assay. The results showed that in the fed-batch culture, the rate of streptokinase production increased over two times as compared with the batch culture while at the same time, shortening the streptokinase purification to a single step increased the yield over 95% at the chromatography stage.

This is a quasi-experimental study that aimed to compare the use of alcohol and traditional methods for newborn's cord care with a no-treatment approach, natural drying. The study also aimed to identify the factors associated with the occurrence of cord infection and time of cord separation. A convenient sample of 70 women with vaginal delivery, full-term and healthy babies was selected from postpartum departments of two university hospitals in Alexandria and Minia. A specially designed interview schedule was developed and utilized to collect data. Swabs were taken from the newborns' umbilical stumps on zero and 3rd day of birth to detect bacterial colonization. Follow-up was carried-out at home to assess methods used for cord care, babies' hygiene, cord infection and time of cord separation. The study revealed that traditional methods of cord care were used by women with higher mean age (30.8 +/- 7.8 years), from Minia (100%) or rural areas (71.4%), while alcohol and natural drying were used by women with lower mean age (27.7 +/- 4.8 and 24.8 +/- 6.5 years) respectively, from Alexandria (76% and 100%) respectively or urban areas (56% and 64.7%) respectively. Alcohol was used for male babies (76%), while traditional methods and natural drying were used for female babies (71.4% & 64.7%) respectively. Incidence of cord infection was significantly lower among natural drying group (35.3%), and no signs of systemic infection were observed among them. Rate of increase of bacterial colonization (from 0-3rd day of birth) was significantly higher in alcohol group (44%). It was relatively similar with presence or absence of cord infection (33.3 & 32.1) respectively. Mean time of cord separation was longer among alcohol group (6.4 +/- 2.4 days), as compared with natural drying group (4.7 +/- 1.9 days) and traditional methods group (3.4 +/- 0.7 days). Bathing baby while cord was attached was carried-out by all women of alcohol and natural drying groups, compared to only 28.6% of traditional methods group. Breast-feeding was significantly related to less incidence of cord infection (P= 0.008) and shorter time of cord separation (P= 0.002). Incidence of cord infection was significantly related to using cloth diaper (P= 0.015), using dry method for skin care (X(2) 2= 7.2917), giving tub bath (X(1)2 = 4.1788) and delaying the bath to the 7th day of birth (P= 0.050). Time of cord separation was significantly shorter with closed cord dressing (X(2)2= 20.4028), in Minia, during spring, among male babies (X(2)2= 15.0352), and in rural areas (X(2)2 = 9.7608). It was significantly longer with bathing the baby while cord was attached (X(2)2 = 27.9354), giving 2-3 baths/week or delaying the bath to the 7th day of birth (P= 0.049) and with using cloth diaper (P= 0.0467). So, moving from an intervention to a non- intervention, particularly in a healthy population should be applied to the healthy naturalistic approach to care advocated in nursing. Also, only through continuing efforts done to examine our assumptions about historic health care routines, will we be able to demonstrate evidence-based practice and to advance nursing care.

Two commercially available all-in-one swab rapid detection systems for Listeria spp. (InSite Listeria Test and Path-Chek hygiene Listeria) were tested for performance in cheese production environments and salmon processing facilities. Sampling was conducted both on clean surfaces and during production. A total of 338 samples were taken using the swabs (175 in cheese environments, 163 in salmon environments). Conventional sampling using sterile cloths and standardized qualitative detection of Listeria spp. according to NMKL method no. 136 was performed in parallel from 64 sampling sites in the salmon processing facilities and 40 sampling sites in the cheese production facilities. Results showed that both rapid swab tests detected Listeria spp.; however, they returned significant amounts of false positives. Presence of Listeria spp. was indicated in 47% and 41% of all swabs in the cheese and salmon environments, respectively. Enrichment followed by selective plating and Listeria specific PCR confirmed none of the 82 presumptive positive swabs from the cheese environment and 16 of 67 presumptive positive swabs from the salmon environments, respectively. Further analysis showed that several other bacteria, including Enterococcus spp. and Carnobacterium maltaromaticum, were the source of false positive swab results. From salmon processing facilities, using cloth sampling and standard analyses, 22% Listeria positive sampling sites were confirmed compared to 9% and 11% positives obtained using InSite or Path-Chek detection systems. From the cheese production environments, no Listeria positive sites were confirmed using either swab or cloth sampling. In conclusion, the use of these rapid detection methods was not suited in the selected environments due to large numbers of false positives, caused by the background flora.

In areas where respirators are not routinely used, emergencies (such as fires) may occur in which protection from airborne particles is necessary. The following readily available materials were tested on a manikin connected to a breathing simulator to determine the fraction of an approximately 2-micron diameter aerosol that would leak around the seal between the materials and the manikin's face: cotton/polyester shirt material, cotton handkerchief material, toweling (a wash cloth), a surgical mask (Johnson & Johnson Co., Model HRI 8137), and a NIOSH-approved disposable face mask (3M Corp., Model #8710). The leakage tests were done to supplement the measurements of penetration through the materials reported previously. Leakage fractions were determined by comparing the penetration of the same aerosol for the materials held to the face versus being fully taped to the face. At a breathing rate of 37 liters per minute, mean leakages for the materials ranged from 0.0 percent to 63 percent, depending on the material. Mean penetrations exclusive of leakage ranged from 0.6 percent to 39 percent. Use of nylon hosiery material ("panty hose") to hold the handkerchief material or the disposable face mask to the face was found to be very effective in preventing leakage. Such a combination could be expected to reduce leakage around the handkerchief to about 10 percent or less in practice, and around the mask to less than one percent, which suggests the adaptation and use of such an approach for industrial hygiene.

Reduction of the initial bioburden on instruments, prior to sterilization, is believed to reduce transmission risks of iatrogenic Creutzfeldt-Jakob disease. Endodontic files are used in the preparation of root canals and are likely to have close contact and become contaminated with neural material from branches of the maxillary and mandibular cranial nerves. This study examined methods used by 22 dental practices to clean endodontic files, and scored visible debris and residual protein levels adhering to 220 dental endodontic files that had been used, cleaned, autoclaved and were deemed ready for re-use. Visible debris was scored after examination under a dissecting light microscope. Residual protein was quantified using a fluorescent assay based on reaction of proteins with o-phthaldialdehyde/N-acetyl cysteine. There was wide variation in the methods used by practices to clean endodontic files. The cleaning process varied from a wipe with an alcohol-impregnated cloth to hand scrubbing and/or use of an ultrasonic bath. Surface debris was visually detected on 98% of files. Residual protein was detected on all the files examined (median amount: 5.4 microg; range: 0.5-63.2 microg). These results demonstrate that the cleaning of some instruments reprocessed routinely in primary care is incomplete, and such instruments cannot be excluded as a potential source of cross-infection.

The phenomenon of neurotransmitter-stimulated incorporation of 32Pi into phosphatidic acid and inositol phosphatides (neurotransmitter effect) in developing brain was studied in vitro as a possible measure of synaptogenesis. While the neurotransmitter effect was not observed with brain homogenates, highly consistent and significant effects were noted with brain tissue suspensions obtained by passing the tissue through nylon bolting cloth. The magnitude of the effect decreased with the increase in mesh number. Maximum stimulations obtained with the 33 mesh adult brain cortex preparations (mean +/- S.E.M. of 6 experiments) were 203 +/- 8%, 316 +/- 17% and 150 +/- 8% with 10(-3) M acetylcholine (ACh) + 10(-3) M eserine; 10(-2) M norepinephrine (NE) and 10(-2) M serotonin (5-HT), respectively. Experiments with developing rat brain at 7, 14 and 21 days of age showed that the neurotransmitter effects due to ACh, NE and 5-HT increase progressively in different regions of the brain but that there are marked regional differences. It is suggested that the neurotransmitter effect is a valid biochemical correlate of synaptogenesis. In rats undernourished from birth to 21 days of age, by increasing the litter size, the neurotransmitter effect with ACh, NE or 5-HT was not altered in the cortex but was significantly reduced in the brain stem. In cerebellum the effects due to ACh and NE were significantly altered, while that with 5-HT was unaffected. It is concluded that cholinergic, adrenergic and serotonergic synapses are relatively unaffected in the cortex but are significantly affected in the brain stem by undernutrition. In the cerebellum of undernourished rats the adrenergic and cholinergic, but not serotonergic systems, are altered.

Forensic genetic analysis of items possibly handled by a suspect or a victim is frequently inquired by the law enforcement authorities, since DNA left on touched objects can often be linked to an individual. Due to technical improvement, even poor traces, which seemed to be unsuitable for DNA analysis a few years ago, may be amplified successfully today. Yet, DNA can be transferred to a crime scene artificially or unintentionally without any primary contact between the individual and the object found at the crime scene, the so-called secondary transfer or indirect transfer in general. In this study, "secondary transfer" scenarios with cells and DNA of different origins under wet conditions were investigated. Transfer was simulated as either "washing by hand" in a washtub or as "machine laundry" in a washing machine. As expected, major differences were seen between blood stains and epithelial abrasions. DNA from blood donors could be detected clearly both on the donor and on the acceptor textile, regardless of washing method. Regarding epithelial abrasions, simulating worn clothes, after washing by hand, only little residual DNA was found, and partial profiles were displayed on the donor textile, while transfer to the acceptor textile occurred even less and not in noteworthy amount and quality. Single alleles could be found both on donor textiles and acceptor textiles after simulated machine wash, but no reliable DNA profile could be verified after laundry in machine. Therefore, a DNA transfer from one worn cloth (without blood stains) to another textile in the washing machine seems to be extremely unlikely.

Theory predicts that variation in plant traits will modify both the direct interactions between plants and herbivores and the indirect impacts of predators of those herbivores. Light has strong effects on leaf quality, so the impacts of herbivores and predators may differ between plants grown in sun and shade. However, past experiments have often been unable to separate the effects of light environment on plant traits and herbivory from direct effects on herbivores and predators. We first manipulated light availability in an open habitat using a shade cloth pre-treatment to produce oak saplings with different leaf qualities. Leaves on plants exposed to high light were thicker and tougher and had lower nitrogen and water contents, and higher carbon and phenolic contents than leaves on plants under a shade cloth. Then, in the main experiment, we moved all plants to a common shade environment where bird predators were excluded in a factorial design. We measured insect herbivore abundance and leaf damage. Herbivores were significantly more abundant and caused greater leaf damage on sun trees, although these leaf characteristics are usually associated with low-quality food. Bird exclusion did not change herbivore abundance but did increase leaf damage. Contrary to our predictions, the effects of birds did not differ between trees grown in sun and shade conditions. Thus, differences in effects of predators on herbivores and plants between light habitats, when observed, might be due to variation in predator abundance and not bottom-up effects of host plant quality.