Plasma electron acceleration driven by a long-wave-infrared laser

Laser-driven plasma accelerators provide tabletop sources of relativistic electron bunches and femtosecond x-ray pulses, but usually require petawatt-class solid-state-laser pulses of wavelength λL ~ 1 μm. Longer-λL lasers can potentially accelerate higher-quality bunches, since they require less power to drive larger wakes in less dense plasma. Here, we report on a self-injecting plasma accelerator driven by a long-wave-infrared laser: a chirped-pulse-amplified CO2 laser (λL ≈ 10 μm). Through optical scattering experiments, we observed wakes that 4-ps CO2 pulses with <  1/2 terawatt (TW) peak power drove in hydrogen plasma of electron density down to 4 × 1017 cm-3 (1/100 atmospheric density) via a self-modulation (SM) instability. Shorter, more powerful CO2 pulses drove wakes in plasma down to 3 × 1016 cm-3 that captured and accelerated plasma electrons to relativistic energy. Collimated quasi-monoenergetic features in the electron output marked the onset of a transition from SM to bubble-regime acceleration, portending future higher-quality accelerators driven by yet shorter, more powerful pulses.

Identifying physiological measures of lifetime welfare status in pigs: exploring the usefulness of haptoglobin, C- reactive protein and hair cortisol sampled at the time of slaughter

BACKGROUND

Physiological measures indicative of the welfare status of animals during rearing could form part of an abattoir-based animal health and welfare assessment tool. A total of 66 pigs were used in this study, the aim of which was to assess how serum concentrations of haptoglobin (Hp) and C-reactive protein (CRP) (assessed in 51 pigs), and hair concentrations of cortisol (assessed in 65 pigs), measured at or close to slaughter, reflected welfare-related indicators recorded from the animal during its lifetime. These indicators were recorded at intervals between 7 and 21 weeks of age and included assigning scores for levels of tail and skin lesions, recording the presence or absence of certain health issues, and conducting qualitative behavioural assessments (QBA).

RESULTS

Pigs recorded as having tail lesions during their lifetime had higher hair cortisol levels than those with no tail lesions (tail lesions: 47.87 ± 3.34 pg/mg, no tail lesions: 42.20 ± 3.29 pg/mg, P = 0.023), and pigs recorded as having moderate or severe tail lesions had higher Hp levels than those with no or mild tail lesions (moderate/severe: 1.711 mg/ml ± 0.74, none/mild: 0.731 mg/ml ±0.10, P = 0.010). Pigs recorded as being lame during their lifetime tended to have higher hair cortisol levels than non-lame pigs (lame: 52.72 pg/mg ± 3.83, not lame: 43.07 pg/mg ± 2.69, P = 0.062). QBA scores were not associated with any of the physiological measures (P > 0.05). Receiver Operator Curve (ROC) analysis was also carried out to get a better understanding of the usefulness of the physiological measures in discriminating animals that had had welfare-related issues recorded during their lifetime from those that had not. Hair cortisol was determined as having 'moderate' accuracy in discriminating pigs that were tail bitten on-farm from unbitten pigs (AUC: 0.748) while Hp and CRP were determined to have no meaningful discriminatory ability (AUC < 0.600).

CONCLUSION

This research should be repeated on a larger scale, but the results suggest that hair cortisol measured at slaughter could provide insight into the welfare status of pigs during their lifetime. Hp may be a useful indicator of tail lesions in pigs. However, further research utilising a greater proportion of severely bitten pigs is required before conclusions can be drawn.

Registered Replication Report: Schooler and Engstler-Schooler (1990)

Trying to remember something now typically improves your ability to remember it later. However, after watching a video of a simulated bank robbery, participants who verbally described the robber were 25% worse at identifying the robber in a lineup than were participants who instead listed U.S. states and capitals-this has been termed the "verbal overshadowing" effect (Schooler & Engstler-Schooler, 1990). More recent studies suggested that this effect might be substantially smaller than first reported. Given uncertainty about the effect size, the influence of this finding in the memory literature, and its practical importance for police procedures, we conducted two collections of preregistered direct replications (RRR1 and RRR2) that differed only in the order of the description task and a filler task. In RRR1, when the description task immediately followed the robbery, participants who provided a description were 4% less likely to select the robber than were those in the control condition. In RRR2, when the description was delayed by 20 min, they were 16% less likely to select the robber. These findings reveal a robust verbal overshadowing effect that is strongly influenced by the relative timing of the tasks. The discussion considers further implications of these replications for our understanding of verbal overshadowing.

Stream insect occupancy-frequency patterns and metapopulation structure

An understanding of the distribution patterns of organisms and the underlying factors is a fundamental goal of ecology. One commonly applied approach to visualize these is the analysis of occupancy-frequency patterns. We used data sets describing stream insect distributions from different regions of North America to analyze occupancy-frequency patterns and assess the effects of spatial scale, sampling intensity, and taxonomic resolution on these patterns. Distributions were dominated by satellite taxa (those occurring in <or=10% of sites), whereas the occurrence of core taxa (occurring in >or=90% of sites) determined the overall modality of occupancy-frequency patterns. The proportions of satellite taxa increased with spatial scale and showed positive relationships with sampling intensity (r2=0.74-0.96). Furthermore, analyses of data sets from New York (USA) showed that generic-level assessments underestimated the satellite class and occasionally shifted occupancy-frequency distributions from unimodal to bimodal. Our results indicate that, regardless of species- or generic-level taxonomy, stream insect communities are characterized by satellite species and that the proportion of satellite species increases with spatial scale and sampling intensity. Thus, niche-based models of occupancy-frequency patterns better characterize stream insect communities than metapopulation models such as the core-satellite species hypothesis.

Eradication of ovine footrot by repeated daily footbathing in a solution of zinc sulphate with surfactant

OBJECTIVE

To investigate the effect on ovine footrot of repeated daily footbathing in a solution of zinc sulphate with surfactant.

DESIGN

Merino sheep were allocated to control and treatment groups of 119 sheep each at week 0. The sheep had a history of S1, U1, T and/or U6 types of Dichelobacter nodosus in interdigital and underrunning footrot lesions. Feet were not pared prior to treatment.

PROCEDURE

Treatment sheep were footbathed in a 15 to 18% (w/v) solution of zinc sulphate with surfactant for 10 min on five consecutive days during week 1. At week 2, and fortnightly to week 52, all feet were inspected, lesion scores were recorded and samples were taken for laboratory tests. At week 53, all feet with no lesions at week 52, but with underrunning lesions prior to week 1, were pared and samples were taken.

RESULTS

After footbathing, there were no lesions in any treatment sheep at any inspection to week 52. The percentage of feet of control sheep with lesions increased from 9% (391 of 4,284) between weeks 20 and 36, to 14% (593 of 4,284) between weeks 36 and 52. Ninety-five of 96 control sheep with no lesions at week 20 were still asymptomatic at week 52. D nodosus was not isolated from samples taken from 99 and 87 pared feet of treatment and control sheep, respectively.

CONCLUSION

Repeated daily footbathing combined with prolonged exposure to a dry environment eradicated footrot in sheep with both interdigital and underrunning lesions in feet that were not pared prior to treatment.

Effects of environmental noise on computer-derived voice estimates from female speakers

The purpose of this study was to examine the influence of noise on voice profile statistics from female samples. Six young adult females served as subjects. Five had normal voices; one had a pathological voice with accompanying bilateral vocal nodules. Each female subject was required to match a generated 235 Hz tone (+/- 2 Hz) while maintaining a constant output level of 70 dB SPL (+/- 5 dB). Data collected from a previous study involving a normal male subject were included for comparative purposes. Noise was generated from a personal computer fan which had a strong center frequency component at 235 Hz. Six different A-weighted signal-to-noise [S/N(A)] conditions were created, ranging in 5 dB increments from 25 to 0 dB. Results revealed that fundamental frequency was reasonably resistant to the effects of noise and to the effects of the noisy (pathological) voice signal. Jitter and shimmer estimates generally increased as noise floors elevated. The greatest amount of measurement error was found for the pathological female voice when captured in the presence of environmental noise. Findings are discussed relative to clinical issues surrounding measurement error.

Occurrence of different strains of Dichelobacter nodosus in new clinical lesions in sheep exposed to footrot associated with multi-strain infections

OBJECTIVE

To investigate the occurrence of S1, U1 and T strains of Dichelobacter nodosus in new clinical lesions in sheep exposed to footrot associated with multi-strain infections.

DESIGN

Seventy-seven donor sheep were grazed with 84 recipients for 33 weeks. The donor sheep were Merinos with a history of clinically virulent footrot associated with protease type S1, U1 and T strains of D nodosus that hybridised with gene sequences pJIR314B, pJIR318 and/or pB645-335. The recipient sheep were Merinos with no history of footrot.

PROCEDURE

Each fortnight, all feet were examined, their lesion scores were recorded and samples of lesion material were taken for laboratory tests.

RESULTS

Eighty-nine percent (299 of 336) of feet of recipient sheep developed new clinical lesions. S1, U1 and T strains of D nodosus were recovered from 58%, 22% and 18%, respectively, of these lesions at a ratio that remained constant during two apparent peaks in footrot transmission. Gene sequences homologous to pJIR314B and pB645-335 were detected in 56% (93 of 166) and 29% (48 of 166), respectively, of S1 strains of D nodosus at a ratio that was not constant during the experiment.

CONCLUSIONS

S1 was the dominant protease type of D nodosus in new clinical lesions. The occurrence of S1 strains did not increase relative to U1 and T strains of D nodosus during the experiment. S1, U1 and T strains of D nodosus remained in equilibrium despite changes in environment, genetic types in the population of S1 strains, and host resistance to footrot.

Severity and persistence of footrot in Merino sheep experimentally infected with a protease thermostable strain of Dichelobacter nodosus at five sites

OBJECTIVE

To test the hypothesis that ovine footrot associated with a thermostable protease strain of Dichelobacter nodosus undergoes self cure or is sustained as an annually recurring disease, depending on the environment.

DESIGN AND PROCEDURE

Forty Merino sheep from a single blood line were infected with a protease thermostable strain of D nodosus at each of five sites in Western Australia. Footrot lesions and microscopic evidence of D nodosus were recorded every fortnight for 2.5 years, supplemented by laboratory culture. Rainfall, soil and air temperature, pasture quantity and composition and soil types were also recorded. Flocks that apparently self cured were relocated to a more favourable site for footrot in the final spring season.

RESULTS

The maximum prevalence of feet with clinical footrot lesions was 80.6, 1.3, 14.4, 3.8 and 88.1% at the five sites. Severe footrot occurred for three consecutive spring seasons at one site that had clay loam soil and at least 3500 kg/ha total pasture dry matter annually. However, the infection was asymptomatic for up to 10 weeks between outbreaks. D nodosus was isolated from flocks for 2.5 years at only two sites, although there was microscopic evidence of the organism at other sites in the final year. A thermolabile variant (strain U6) of D nodosus was isolated from the two sites where footrot persisted.

CONCLUSION

Depending on time and location, ovine footrot induced by a protease thermostable strain of D nodosus either self cured or persisted as annual outbreaks interspersed with periods of asymptomatic infection.

Comparison of gene probe and conventional methods for the differentiation of ovine footrot isolates of Dichelobacter nodosus

In a collaborative study that involved four Australian veterinary diagnostic laboratories a gene probe test based on the recombinant plasmids pJIR318, pJIR314B, and pJIR313, which contain genomic vap or vrl regions, was compared with conventional tests used for the differential diagnosis of ovine footrot. A total of 771 clinical dichelobacter nodosus isolates were tested and designated as belonging to one of several gene probe categories. The results showed that 87% of the virulent isolates belonged to gene probe category 1, compared to only 6% of the benign isolates. It was concluded that there was good correlation between the gene probe test and the virulence designation of these isolates as well as the results of elastase, gelatin-gel and protease isoenzyme tests. Furthermore, the gene probe test was converted to a polymerase chain reaction (PCR)-based test. It is suggested that diagnostic laboratories consider carrying out both this PCR test and tests based on the extracellular proteases of D. nodosus.

FGF suppresses apoptosis and induces differentiation of fibre cells in the mouse lens

To determine whether fibroblast growth factor (FGF) has a role in lens development, we have generated transgenic mice expressing a dominant-negative form of the murine FGF receptor-1 (FGFRDN) in the lens. Using the fibre cell-specific alpha A-crystallin promoter to express the FGFRDN, we have asked whether FGF is required for fibre cell differentiation. The transgenic mice display diminished differentiation of fibre cells as indicated by their reduced elongation. In addition, transgenic lenses have an unusual refractile anomaly that morphological and biochemical data show results from the apoptosis of fibre cells in the central region of the lens. These results show that lens fibre cells are dependent on FGF for their survival and differentiation, and demonstrate that growth factor deprivation in vivo can lead to apoptosis.

Seasonal characteristics of ragweed pollen dispersal in the United States

BACKGROUND

The most definitive reports concerning the seasonal characteristics of ragweed (Ambrosia spp) pollen dispersal in the United States date back 60 years to work conducted with gravity slide samples.

OBJECTIVE

Volumetric pollen data from 23 sampling sites were used to study the ragweed pollen season.

METHODS

The date of first and final pollen capture and the date with maximum airborne pollen concentration (the "peak date") were used to compare the pollen seasons at locations ranging from approximately 30 degrees N to 45 degrees N latitude.

RESULTS

Sixteen cities located north of 38 degrees N possessed similar peak dates (P = 1), generally achieving maximum airborne pollen concentration in late August or early September. Four cities located south of 38 degrees N experienced later peak dates, with the most southerly city reaching maximum pollen levels in mid-October. Three cities located in the Northwest did not recover ragweed pollen in air samples.

CONCLUSION

This study confirms earlier reports and suggests what time of year source avoidance is most critical for ragweed sensitive individuals in various locations.

The laboratory culture of Dichelobacter nodosus in a footrot eradication program

As part of a program to eradicate virulent footrot from Western Australia, 2745 isolates of Dichelobacter nodosus were isolated from 5263 specimens from 1883 submissions. The virulence of each isolate was assessed using protease thermostability and isoenzyme zymogram. We describe changes to the materials and methods required to handle these specimens and to reduce the interval between submission and report to 8 days.

Simultaneous measurement of urethral opening pressure and urethral cross-sectional area during voiding cystometry

OBJECTIVE

To assess a new technique for measuring urethral opening pressure and urethral cross-sectional area during the course of routine voiding cystometry.

PATIENTS AND METHODS

Twenty-eight male patients were studied, 24 of whom had cystometric evidence of bladder outlet obstruction, the other four being unobstructed. Urethral opening pressure was measured using an adapted fluid bridge test and urethral cross-sectional area was measured using the method described in the preceding paper.

RESULTS

The mean urethral opening pressure in the obstructed patients was 68 cm/H2O (range 38-124) against a mean of 19 cm/H2O (range 16-22) in the unobstructed group. The mean urethral cross-sectional area in the obstructed group was 2.6 mm2 (range 0.9-7.9) compared with a mean of 14.2 mm2 (range 10.8-19.9) in the unobstructed patients.

CONCLUSION

This technique allows measurement of the parameters of bladder outlet obstruction described by Schäfer during routine voiding cystometry, without specialized equipment. This provides a simple method for quantification of urinary outflow obstruction and should prove useful in the assessment of new treatment modalities.

Elimination of the influence of intravesical pressure on the micturitional urethral pressure profile by calculation of urethral cross-sectional area: an experimental study

OBJECTIVE

To determine whether it is possible to eliminate the influence of intravesical pressure on the pressure drop recorded between the bladder and prostatic urethra during the micturitional urethral pressure profile (MUPP).

MATERIALS AND METHODS

An experimental study using an artificial bladder/urethral model and computerized urethral pressure profile measurement system.

RESULTS

By simultaneous measurement of the flow rate and MUPP it is possible to calculate a theoretical cross-sectional area, based on Griffiths' theory of flow through distensible tubes. The calculated cross-sectional area for a given constriction remains the same despite changes in the driving pressure.

CONCLUSION

The effect of changes in intravesical pressure on the MUPP can be eliminated by calculation of the urethral cross-sectional area. This parameter forms part of the Schäfer model of obstruction and this technique may therefore be useful in quantifying bladder outlet obstruction.

Quantification of bladder outlet obstruction by measurement of urethral opening pressure using an adapted fluid bridge test

A new technique for measuring urethral opening pressure above the distal sphincter is described, based on the fluid bridge test. This test eliminates many of the inaccuracies produced when using standard pressure flow studies. Nineteen males were studied, 15 of whom had cystometric evidence of bladder outlet obstruction, the other 4 being unobstructed. The mean urethral opening pressure in the obstructed group was 69 cm H2O (range 44-124) and in the unobstructed group 19 cm H2O (range 16-22). The test is simple to perform and is not affected by muscular activity in the pelvic floor or the time lag between detrusor pressure and flow rate measurement.

Routine estimation of prostate specific antigen prior to clinic attendance in patients with symptoms of bladder outlet obstruction

We report the use of serum prostate specific antigen (PSA) estimations prior to clinic attendance in 234 patients referred with symptoms of bladder outlet obstruction to a general urology clinic. Ninety-three patients with PSA levels > 10 ng/ml were seen earlier than planned and offered transurethral resection or transrectal biopsy of the prostate gland. Forty-six patients (49%) proved to have carcinoma of the prostate, compared with 10 of 141 (7%) patients who had PSA values < 10 ng/ml. With a decision value of 10 ng/ml, the sensitivity for detecting carcinoma was 82% and specificity 73.5%. Using a decision value of 7 ng/ml improved the sensitivity to 95% without significantly affecting the specificity (70%). Twenty-four patients with prostatic cancer had bone metastases; the sensitivity of PSA for predicting a positive bone scan using a decision value of 25 ng/ml was 92%, but the specificity was only 31%.

A gelatin test to detect activity and stability of proteases produced by Dichelobacter (Bacteroides) nodosus

Previously reported tests to distinguish thermostable and thermolabile proteases of Dichelobacter nodosus used hide powder azure as a test substrate. This paper describes an alternative test for protease stability using gelatin, an inexpensive and convenient substrate. The test required less equipment and time than the hide powder tests, and simplified the testing of multiple samples. Proteases from 2965 isolates of D. nodosus from samples collected as part of a footrot eradication scheme were tested using the gelatin method, 1707 produced thermostable, and 1258 produced thermolabile protease. Production of thermostable protease was used to identify isolates of D. nodosus which had the potential to cause the virulent form of ovine footrot. Comparisons were made with a hide powder test on 47 isolates. Further characterisation of all proteases was undertaken using polyacrylamide gel electrophoresis. Isoenzyme patterns of thermostable protease producing isolates were identified as S1 (1688 isolates) and S2 (19) whilst thermolabile protease producing isolates showed patterns U1 (1104 isolates), U2 (40), U3 (32), U4 (47), U5 (6), U6 (28) and S1 (1).

Reliability of filter-strip sampling of gingival crevicular fluid for volume determination using the Periotron

This study explored gingival cervicular fluid (GCF) volumes as measured by the Periotron in an attempt to find a more objective measure of gingival inflammation that could be used in dental compliance studies. The first step in this process was to assess the reliability of the method of collecting and determining GCF volumes as described by the manufacturer. Collections of GCF from both the buccal and lingual surfaces of 6 teeth from 18 subjects with good to moderate plaque accumulation was accomplished. At a later time these same surfaces were retested for a comparison with the initial value for reliability determination. We found that only 23% of the tooth surface pairs varied by less than 20% and 57% of these pairs differed by at least 50%. These values were similar for both good and moderate plaque accumulation subjects. In these subjects, reliability measurements at individual tooth surfaces did not approach acceptable levels of reliability. However, when the GCF values from the 12 tooth surfaces were averaged for each subject, differences between the two measurements improved markedly. Sixty-one percent of these subject pairs differed by less than 20%. Therefore, the average GCF value from subjects with good to moderate plaque accumulations may be compared with reasonable accuracy.

Spontaneous regression of metastatic renal cell carcinoma

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Biosynthetic thiolase from Zoogloea ramigera. Mutagenesis of the putative active-site base Cys-378 to Ser-378 changes the partitioning of the acetyl S-enzyme intermediate

The proposed active-site base Cys-378 of thiolase, responsible for deprotonation of acetyl-CoA, has been converted to a less acidic residue Ser-378 by mutagenesis. Comparison of the CD spectra and dimethyl suberimidate cross-linking experiments of the wild type, mutant Ser-378, and Gly-378 enzymes indicated that there have been no major conformational changes. The Ser-378 enzyme retains 0.1% of the Vmax of wild type in the direction of acetoacetyl-CoA thiolytic cleavage and 0.07% of the Vmax in the Claisen condensation direction. Analysis of the acetyl S-enzyme intermediate partitioning, that is capture of the acetyl enzyme by 1) the thiolate of coenzyme A relative to 2) the C-2 carbanion of acetyl-CoA, is changed to favor reaction 2 in the case of the Ser-378 mutant enzyme.

Biosorption of metal ions by Armillaria rhizomorphs

Armillaria rhizomorphs consist of differentiated hyphae with a melanized outer cortex. Melanin is known to prevent lysis of fungal structures by hydrolytic enzymes and may protect against antagonistic microorganisms. Our studies indicate that melanized rhizomorphs also adsorb high concentrations of cations from the surrounding soil environment. Rhizomorphs of four Armillaria species (A. ostoyae (Romagn.) Herink, A. calvescens Bérubé & Dessureault, A. gemina Bérubé & Dessureault, and A. sinapina Bérubé & Dessureault) collected from Minnesota, New Hampshire, and Oregon had substantially elevated levels of metal ions compared with the soil from which they were collected. With some elements, ions were 50–100 times more concentrated on rhizomorphs than in soil. Concentrations of Al, Zn, Fe, Cu, and Pb on rhizomorphs ranged up to 3440, 1930, 1890, 15, and 680 μg/g, respectively. Energy dispersive X-ray microanalysis showed that metal ions were located only on the outer portions of the rhizomorphs and not concentrated in the interior. A coating of metal ions may play a key role in the longevity and survival of rhizomorphs in soil. Key words: Armillaria, rhizomorphs, metals, fungal antagonism.

Biosynthetic thiolase from Zoogloea ramigera. Evidence for a mechanism involving Cys-378 as the active site base

Biosynthetic thiolase from Zoogloea ramigera was inactivated with a mechanism-based inactivator, 3-pentynoyl-S-pantetheine-11-pivalate (3-pentynoyl-SPP) where K1 = 1.25 mM and kinact = 0.26 min-1, 2,3-pentadienoyl-SPP obtained from nonenzymatic rearrangement of 3-pentynoyl-SPP where K1 = 1.54 mM and kinact = 1.9 min-1 and an affinity labeling reagent, acryl-SPP. The results obtained with the alkynoyl and allenoyl inactivators are taken as evidence that thiolase from Z. ramigera is able to catalyze proton abstraction uncoupled from carbon-carbon bond formation. The inactivator, 3-pentynoyl-SPP and the affinity labeling reagent, acryl-SPP, trap the same active site cysteine residue, Cys-378. To assess if Cys-378 is the active site residue involved in deprotonation of the second molecule of acetyl-CoA, a Gly-378 mutant enzyme was studied. In the thiolysis direction the Gly-378 mutant was more than 50,000-fold slower than wild type and over 100,000-fold slower in the condensation direction. However, the mutant enzyme was still capable of forming the acetyl-enzyme intermediate and incorporated 0.81 equivalents of 14C-label after incubation with [14C]Ac-CoA for 60 min. The reversible exchange of 32P-label from [32P]CoASH into Ac-CoA, catalyzed by the Gly-378 mutant enzyme, proceeded with a Vmax (exchange) 8,000-fold less than the wild type enzyme but at least 10-fold faster than the overall condensation reaction. These data provide evidence that Cys-378 is the active site base.

Inferior vena cava occlusion secondary to aortic aneurysm

A case of inferior vena caval thrombosis secondary to aortic aneurysm is presented with management guidelines. CT scanning, as well as conventional venography and arteriography, is very useful in understanding this process preoperatively. Intraoperative management should prevent pulmonary embolism and should anticipate the possibility of blood loss in excess of that which usually occurs with an uncomplicated aneurysm repair. Detailed review of the literature reveals this is a rare complication of aneurysm disease and a potentially lethal one.

Successful control of endemic MRSA in a cardiothoracic surgical unit

After a substantial increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the Cardiothoracic Surgical Unit at St. Vincent's Hospital, Sydney, a prospective study was undertaken in early 1986 to ascertain the carrier status of all patients entering the Unit. Of 84 patients, 27.4% were found to carry MRSA and the perineum was the major site of carriage, with 69.6% of MRSA positive cases carrying the organism in this site. As a result of these findings, the period of perioperative antibiotic cover was shortened, whole-body washing of patients with a 1% triclosan preparation was instituted and routine postoperative perineal swabs were taken. During the 18 months after implementation of these policies, a highly significant reduction in the number of MRSA carriers and infections was observed. The monitoring of perineal colonization proved to be a useful marker for increases in MRSA in the Unit.

Comparison of regional and general anesthesia for carotid endarterectomy

Two hundred twenty-one patients undergoing carotid endarterectomy were studied for morbidity and mortality. Thirty-seven had general anesthesia and 138 had regional anesthesia. The two groups were similar in preoperative risk factors and were operated on by a single surgeon and similar operative teams. Patient selection was prospective in the sense that the first 37 procedures were performed with general anesthesia and the next 184, with regional anesthesia. No significant difference in incidences of death, myocardial infarction, stroke, or transient ischemic attack was found. Hospital lengths of stay were similar. The type of anesthetic used for carotid endarterectomy should be the choice of the surgeon and operative team.

Sepsis-induced depression of phagocytosis in experimental canine peritonitis

Experimental canine peritonitis was produced in 14 dogs by appendiceal ligation. Phagocytic activity in blood and peritoneal fluid was examined during the peritonitis and following surgical intervention. In nine dogs, the gangrenous appendix was resected after 43 hours, the peritoneal cavity was irrigated, and fibrinous exudate debrided. The remaining five dogs were not tested. Leukocytes in blood and peritoneal fluid were counted preligation and at 24, 43, 46, and 55 hours postligation. Polymorphonuclear leukocytes (PMNs) predominated. Phagocytosis and killing of Candida tropicalis by blood and peritoneal PMNs were assayed by a coverslip method. As sepsis progressed, phagocytosis by blood PMNs declined and at 43 hours was 60 per cent of the preoperative level. After resection of the gangrenous appendix, phagocytic activity returned to 90 per cent of preoperative levels at 12 hours postresection. Peritoneal PMNs exhibited a similar, but more depressed pattern of phagocytic activity. Phagocytosis in five sham-operated dogs was unchanged. Thus, phagocytosis by blood and peritoneal PMNs was depressed in peritonitis and was restored following surgical treatment.

Unreported adverse drug reactions determined by screening physician orders for diphenhydramine

According to the standards developed by the Joint Commission on the Accreditation of Hospitals, all adverse drug reactions should be reported following written procedures. An Adverse Drug Reaction Reporting Program is conducted by the Department of Pharmacy Services under the direction of the Pharmacy and Therapeutics Committee. However, many of the adverse drug reactions that occur go unreported. The purpose of the study was to determine whether patients can be screened for particular adverse drug reactions by reviewing the charts of patients having medication orders for diphenhydramine. While 48% of the patients included in the study had received diphenhydramine for treatment of an allergic reaction to a medication, none of the cases involving these reactions were reported according to the written procedures governing the Adverse Drug Reaction Reporting Program. The results of the study indicate that by auditing the prescribing of certain medications one can identify patients having complications due to their drug therapy. A more comprehensive study program could be developed which would screen for many types of adverse drug reactions and audit all of the drugs used to treat these drug-induced illnesses.

Intracranial pressure monitoring in the acute neurologic assessment of multi-injured patients

The trauma victim with a severe closed head injury, who requires general anesthesia for emergency repair of concomitant exigent major injuries, poses a clinical dilemma. During general anesthesia and during the immediate postoperative period, the status of the patient's central nervous system cannot be clinically monitored, and emergency cerebral arteriograms and/or CAT scans are not easily obtained. Under these circumstances, delays in the diagnosis of intracranial blood accumulations frequently occur, and occult cerebral edema often goes untreated. In an attempt to avoid these management problems, we have employed intraoperative intracranial pressure (ICP) monitoring in such patients, using a subarachnoid screw. Following placement of this screw, several clinical courses may occur: 1) The patient maintains a normal pressure; thus a significant mass lesion and/or cerebral edema requiring decompression is unlikely. 2) The patient's ICP is elevated but controlled by medical management. 3) The patient's ICP cannot be controlled below 20 to 25 mm Hg using medical management, and exploratory burr holes are made. 4) If intracranial blood is encountered during placement of the ICP monitor, immediate exploratory craniotomy is indicated.

Release of rabbit aorta contracting substance (RCS) and prostaglandins induced by chemical or mechanical stimulation of guinea-pig lungs

1. Rabbit aorta contracting substance (RCS) and prostaglandins were released from guinea-pig isolated perfused lungs by gentle massage and also by infusion of Prosparol.2. RCS and prostaglandins were also released by infusion into the pulmonary artery of bradykinin, arachidonic and dihomo-gamma-linolenic acids or shock perfusate (containing RCS-releasing factor).3. Arachidonic and dihomo-gamma-linolenic acids caused a prolonged release of RCS and prostaglandins whereas bradykinin and shock perfusate gave a short-lasting output.4. RCS and prostaglandins, together with histamine were released when superfused chopped lung tissue was agitated.5. Challenge of sensitized guinea-pigs in vivo led to the release of an RCS-like substance into the carotid arterial blood.6. Intravenous injection of bradykinin into guinea-pigs also released an RCS-like substance.7. The release of RCS and prostaglandins was inhibited by aspirin or indomethacin in all experiments.8. RCS contracted all vascular tissues investigated and also rat stomach strip.9. The half-life of RCS was estimated as 1-2 minutes.