Functional requirements of a desktop clinical image display application

The requirements for a clinical viewing station have some similarities to requirements of an interpretation workstation, but have some important differences. The user base is a heterogeneous group, and the tasks the clinicians perform vary substantially, increasing the variation in the requirements. However, it is possible to determine a list of requirements that satisfy most clinicians under most circumstances. In addition to the standard image manipulation tools, we have found that integration with the other clinical tools is essential to maintaining or increasing their efficiency. Providing for varying levels of functionality/complexity is also useful, because of the variation in the user base.

Effects of Na-K-2Cl cotransport regulators on outflow facility in calf and human eyes in vitro

PURPOSE

Cultured human trabecular meshwork (TM) cells possess substantial Na-K-Cl activity, which is involved in the regulation of TM cell volume. The hypothesis in the present study was that drugs that affect the cotransporter might alter aqueous humor outflow facility (C) in the intact eye. The effects of agents and conditions known to modulate Na-K-CI cotransport activity and/or TM cell volume on C in perfused anterior segments were investigated.

METHODS

Human and calf eyes were dissected and perfused, and C was determined according to standard published methods. Perfusates with modified osmolarity were used to cause alterations in TM cell volume. Cl-free perfusate and/or bumetanide (10(-5) M) was used to inhibit Na-K-Cl cotransport activity, and vasopressin (10(-7) M, 10(-8) M) was used to stimulate cotransport activity.

RESULTS

In human eyes, hypo-osmotic perfusate decreased C 12%, whereas hyper-osmotic perfusate increased C 44%. These changes lasted approximately 30 minutes, after which C began to normalize. Inhibition of Na-K-Cl cotransport using Cl-free medium or bumetanide resulted in facility increases of 27% and 22%, respectively. There was an additive increase in C with bumetanide plus Cl-free media. Stimulating Na-K-Cl cotransport with 10(-8)M and 10(-7)M vasopressin resulted in 28% and 35% decreases in C, respectively. The results were similar in calf eyes: Cl-free medium or bumetanide resulted in 41% and 52% increases in C, whereas 10(-8) M and 10(-7) M vasopressin resulted in 14% and 19% decreases in C, respectively.

CONCLUSIONS

Modulation of Na-K-Cl cotransport results in changes in C that may be mediated in part by cell volume changes.

An investigation into the structural determinants of cannabinoid receptor ligand efficacy

1. A number of side-chain analogues of delta8-THC were tested in GTPgammaS binding assay in rat cerebellar membranes. O-1125, a saturated side-chain compound stimulated GTPgammaS binding with an Emax of 165.0%, and an EC50 of 17.4 nM. 2. O-1236, O-1237 and O-1238, three-enyl derivatives containing a cis carbon-carbon double bond in the side-chain, stimulated GTPgammaS binding, acting as partial agonists with Emax values ranging from 51.3-87.5% and EC50 values between 4.4 and 29.7 nM. 3. The stimulatory effects of O-1125, O-1236, O-1237 and O-1238 on GTPgammaS binding were antagonized by the CB1 receptor antagonist SR 141716A. The K(B) values obtained ranged from 0.11-0.21 mM, suggesting an action at CB1 receptors. 4. Five-ynyl derivatives (O-584, O-806, O-823, O-1176 and O-1184), each containing a carbon-carbon triple bond in the side-chain, did not stimulate GTPgammaS binding and were tested as potential cannabinoid receptor antagonists. 5. Each -ynyl compound antagonized the stimulatory effects of four cannabinoid receptor agonists on GTPgammaS binding. The K(B) values obtained, all found to be in the nanomolar range, did not differ between agonists or from cerebellar binding affinity. 6. In conclusion, alterations of the side-chain of the classical cannabinoid structure may exert a large influence on affinity and efficacy at the CB1 receptor. 7. Furthermore, this study confirms the ability of the GTPgammaS binding assay to assess discrete differences in ligand efficacies which potentially may not be observed using alternative functional assays, thus providing a unique tool for the assessment of the molecular mechanisms underlying ligand efficacies.

Potent cyano and carboxamido side-chain analogues of 1', 1'-dimethyl-delta8-tetrahydrocannabinol

The synthesis and pharmacological profile of several cyano (1a-e) and carboxamido (2a-h) side-chain-substituted analogues of 1', 1'-dimethyl-Delta8-THC are described. Commercially available cyano compound 3 was transformed to the resorcinol 6 in a three-step sequence. Condensation of 6 with p-menth-2-ene-1,8-diol formed the THC 7a which, with sodium cyanide/DMSO, gave 1b. Protection of the phenol in 7a as the MOM derivative provided the common intermediate 8 for the synthesis of 1a,c,e. Compound 1d was also synthesized from 7a via the aldehyde 9a. Base hydrolysis of 1b gave the acid 10 which, via its acid chloride and subsequent treatment with the appropriate amine, formed the target compounds 2a-h. The pharmacological profile indicated that the cyano analogues 1a-e had very high CB1 binding affinity (0.36-13 nM) and high in vivo potency as agonists. Two analogues (1a,b) had extremely high potency in the mouse tetrad tests. The dimethylcarboxamido analogue 2a showed a similar profile to 1a,b. The high potency was also retained in analogue 2c. In contrast the sulfonamide analogue 2d was unique as it had greater affinity than Delta9-THC, yet it was practically devoid of agonist effects. This study suggests that the incorporation of a cyano or an amide substituent in the side chain of Delta8-THC-DMH can enhance potency and can also lead to compounds with a unique profile which have high binding affinity and are practically devoid of agonist effects.

Evaluation of cannabimimetic effects of structural analogs of anandamide in rats

Arachidonylethanolamide (anandamide), an endogenous ligand for the cannabinoid receptor, binds competitively to brain cannabinoid receptors and shares many, but not all, of the in vivo effects of delta9-tetrahydrocannabinol. In this study, the cannabinoid effects of anandamide analogs in which the anandamide molecule was altered were assessed in a drug discrimination model. Structural manipulations of the anandamide molecule included saturation of the arachidonyl moiety with fluorination (O-586), substitution for either the ethanolamide moiety (O-612 and O-595) or C2' hydroxyl (O-585), and addition of a methyl group at various positions (O-610, O-680, and O-689). Despite the low binding affinities of the non-methylated compounds (Ki values > 2000 nM), all of the analogs had previously shown cannabinoid activity in mice. In the present study, these analogs were tested in a more pharmacologically specific delta9-tetrahydrocannabinol discrimination procedure in rats. This animal model is predictive of the subjective effects of marijuana intoxication in humans. Whereas delta9-tetrahydrocannabinol and an aminoakylindole fully substituted for the training dose of 3 mg/kg delta9-tetrahydrocannabinol, anandamide and its non-methylated analogs were not cannabimimetic in this procedure. Methylation appeared to increase binding affinity (Ki values < 150 nM) and efficacy; however, the greatest substitution produced by the methylated analogs occurred only at doses that decreased overall rates of responding, suggesting that these analogs are not fully delta9-tetrahydrocannabinol-like. The rapid metabolism of anandamide and some of its analogs undoubtedly contribute to the differences between the pharmacological profiles of the anandamides and classical cannabinoids. These results support the prediction that the subjective effects of anandamide analogs that have been developed thus far would not be cannabimimetic except at high doses.

Clinician usage patterns of a desktop radiology information display application

We developed a system for delivering radiologic images and reports to desktop computers used for the electronic medical record (EMR). This system was used by both primary care physicians and specialists primarily in the out-patient setting. The system records all physician interactions with the application to a database. This usage information was then studied in order to understand the value and requirements of an application that could display radiology information (reports and images) on EMR workstations. In this report we describe some of the differences and similarities in usage patterns for the two physician groups. A very high percentage of physicians indicated that having image display capabilities on the workstations was very valuable.

A preliminary report: a new scale to identify the pseudodementia syndrome

BACKGROUND

The literature was reviewed to abstract items which were claimed to distinguish organic dementia from pseudodementia. Their discriminating powers were tested in a prospective study. Eighteen of these items were selected to create a questionnaire which should distinguish organic dementia from pseudodementia. The gold standard was the final diagnosis given by a consultant psychiatrist 12-14 months later.

METHOD

One hundred and twenty-eight patients referred to our service with a differential diagnosis of depressive pseudodementia were screened using a checklist of 44 characteristic features (in the form of questions with 'yes' or 'no' answers) which were claimed in the literature of differentiate between organic dementia and depressive pseudodementia. This checklist covers the areas of history, clinical data, insight and performance.

RESULTS

Forty points (questions) out of the 44 in the checklist showed significant discriminating power to differentiate dementia from depressive pseudodementia (p < 0.01). A principal component and factor analysis was performed from which 18 questions were extracted. The shortened questionnaire was able to classify (43/44 cases) 98% of dementia cases and (60/63) 95% of depression correctly. A new definition has been introduced for 'pseudodementia' as a syndrome of reversible subjective or objective cognitive problems caused by non-organic disorder. Thus depressive pseudodementia may be classified into two subtypes. Type I is a group of patients who have depressive symptoms with subject complaint of dysmnesia without measurable intellectual deficits. Type II is a group of patients who have depressive symptoms and show poor cognitive performance based on poor concentration not due to organic disorder.

Tracheoesophageal speech: predictors of success and social validity ratings

PURPOSE

The purpose of this study was to examine long-term success rates and predictors of success for patients who had undergone either primary or secondary tracheoesophageal puncture. An additional aim was to compare judgments of communication effectiveness made by a speech-language pathologist with those made by the patient or significant other.

PATIENTS AND METHODS

Thirty-six laryngectomees were initially rated on a 5-point functional communication scale. These ratings resulted in the formation of two distinct groups that were identified as "successful" and "unsuccessful." The groups were compared on the basis of age at time of surgery and 10 categorical variables that have been implicated in the success or failure of tracheoesophageal puncture surgery.

RESULTS

Results indicated that nearly two thirds of the patients had successful communication at an average of approximately 4 years posttracheoesophageal puncture. For the 13 patients judged as "unsuccessful," reduced vision, limited arm/hand movement, and history of radiotherapy were found in significantly greater numbers. When communication profile ratings made by a speech-language pathologist were compared with those made by the patient or significant other (P/SO), approximately one-third varied by at least "1" scale value, with the vast majority resulting in comparatively higher ratings by the speech-language pathologist.

CONCLUSION

The findings of this study are in general agreement with previously published success rates for tracheoesophageal puncture and attest to the long-term nature of these success rates in a majority of patients. Additional investigation is necessary to identify factors that may contribute to discrepancies between clinician expectations and those of the patient or significant other.

Evaluation of cannabimimetic discriminative stimulus effects of anandamide and methylated fluoroanandamide in rhesus monkeys

In previous research arachidonylethanolamide (anandamide) has been shown to produce behavioral effects in mice characteristic of psychoactive cannabinoids, including antinociception, catalepsy, hypothermia, and hypomotility. However, differences have also been found between anandamide and delta9-tetrahydrocannabinol (delta9-THC), with anandamide having lower potency, a more rapid onset, and shorter duration of action than delta9-THC. Although it can produce delta9-THC like discriminative stimulus effects in rats, anandamide also produces concomitant response rate decreasing effects, whereas with delta9-THC there is a better separation of these two behavioral effects. The present study was designed to examine the discriminative stimulus effects of anandamide in rhesus monkeys trained to discriminate delta9-THC from vehicle. While anandamide failed to produce reliable substitution for delta9-THC and did not reduce response rates at doses up to 10 mg/kg, 2-methylarachidonyl-2'-fluoroethylamide (methylated fluoroanandamide), a putative stable analog of anandamide, produced full dose-dependent substitution for delta9-THC at doses that caused no significant changes in response rates. These results suggest that systemically administered anandamide may be metabolized in monkeys before behaviorally active concentrations could reach the brain and further suggest that the metabolically more stable analog of anandamide, methylated fluoroanandamide, may aid in the discovery of functional properties of the endogenous cannabinoid system.

Potent anandamide analogs: the effect of changing the length and branching of the end pentyl chain

To examine the effect of changing the length and branching of the end pentyl chain (C5H11) of anandamide (AN), various analogs 1a-h and 2a-f were synthesized from either the known aldehyde ester 6a or from the alcohol 6b and tested for their pharmacological activity. A reproducible procedure was developed for the conversion of arachidonic acid to 6a or 6b in gram quantities (overall yield 15%). The appropriate tetraene esters 7 were prepared by carrying out a Witting reaction, between 6a and the ylide generated from the phosphonium salt of the appropriate alkyl halide or between the ylide of 6d (prepared from 6a-->6b-->6c-->6d) and the appropriate alkyl aldehydes. They were then hydrolyzed to the corresponding acids and transformed into AN analogs 1 via their acid chlorides then treated with excess ethanolamine. alpha-Alkylation of esters 7 gave compounds 8 which were hydrolyzed to the corresponding acids. These acids via their acid chlorides and subsequent treatment with excess fluoroethylamine gave the target compounds 2. In this way analogs 1e and 2a-c were synthesized from 6d while all the remaining analogs were prepared from 6a. In order to assess the optimal length of the alkyl terminus, analogs 1a-d were prepared and showed moderately high affinities (18-55 nM). However analogs 1a-c failed to produce significant pharmacological effects at doses up to 30 mg/kg. Analog 1d was found to be a weak partial agonist. The reason for the lack of activity in 1a-c is presently not clear. Like the THCs, the branching of the end pentyl chain in AN (1e-h) increased potency both in in vitro and in vivo activities; the dimethylheptyl (DMH) analog 1e was the most potent in the series. Similar alkyl substitutions were carried out in the fluoro-2-methylanandamide series (2a-f), and all of these analogs had high receptor affinities (1-14 nM), the DMH analog 2a being the most potent. With a few exceptions they showed robust pharmacological effects, and AN-like profiles. It was shown that the SAR of the end pentyl chain in AN is very similar to that of THCs. However, the magnitude of enhanced potency observed when the side chain of THC was changed from straight to branched was not observed when the end chain of AN was similarly changed.

Image display for clinicians on medical record workstations

Image display on electronic medical record (EMR) workstations is an important step in widespread implementation of picture archiving and communications systems (PACS). We describe a pilot project for implementing image display capability that is integrated with the EMR software, and will allow display of images on the physician's workstation. We believe this pilot will provide valuable information about usage patterns in image display needs, which will be valuable in planning further expansion of PACS in our institution.

READS: a radiology-oriented electronic analysis and display station

READS is a picture archiving and communications system (PACS) display program that is tailored to allow a radiologist to efficiently perform image review tasks. In this study, the image review process was observed and functional patterns were identified. These were used to define a design that was considered to represent the optimal balance of compromises for a low-cost review station that also allowed easy addition of new functionality. As a result, a program was designed and implemented that has been found to be acceptable for image review and for special image processing function development.

Bullatacin--in vivo and in vitro experience in an ovarian cancer model

The cytotoxicity and antitumor effects of the acetogenin Bullatacin were evaluated in vitro in multiple ovarian cancer cell lines and in vivo in a murine ovarian teratocarcinoma (MOT) model in C3HeB/FeJ mice. The in vitro cytotoxicity of Bullatacin against four human ovarian epithelial tumor cell lines (OC-194, OC-222, OVCAR-3, and A-2780) was assessed in 48- and 72-h tetrazolium-dye (MTT) cytotoxicity assays. The percentage of cytotoxicity was determined on the basis of the mean optical density of the respective untreated cells and the dose effective against 50% of the cells (ED50) was calculated for each cell line. In vivo experiments were performed on adult female C3HeB/FeJ mice, which were injected i.p. with 10(5) MOT cells and varying amounts of Bullatacin given either in a single dose or in 5 subsequent doses over 72 h. All mice were observed for survival relative to that of the control groups, which were injected either with 10(5) MOT cells with or without serial injections of vehicle or with vehicle only. All four epithelial ovarian cancer cell lines displayed sensitivity to Bullatacin. The relative cytotoxic effects were very heterogeneous, with the ED50 value ranging between 10(-7) micrograms/ml for OC-194 and 4 micrograms/ml for the cisplatin-resistant cell line OVCAR-3 in a 72-h MTT cytotoxicity assay. All mice that had been injected i.p. with 10(5) MOT cells and 1.4 mg/kg or more of Bullatacin died within the first 24 h after injection, whereas all mice that had received 600 micrograms/kg of Bullatacin or less survived equally as long as the controls that had been injected with MOT only (21.1 +/- 0.9 days). Mice that had received Bullatacin at a dose ranging from 600 micrograms/kg to 1.4 mg/kg either died during the 1st day postinjection or survived, but not longer than the MOT control group. Serial i.p. injections of Bullatacin again either led to death of the mice within 24-48 h of the last dose of Bullatacin or did not have any effect on the survival of the mice as compared with the respective control groups, which had been injected with the tumor and serial injections of vehicle (22.5 +/- 2.2 days). In summary, Bullatacin showed no effect on MOT-caused animal death in C3HeB/FeJ mice at nonlethal dose ranges, whether it was given as a single i.p. dose or serially over 72 h. In vitro, however, it proved to be a very potent cytotoxic agent in a variety of ovarian cancer cell lines.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterization of a human alpha 1-antitrypsin null allele involving aberrant mRNA splicing

alpha 1-Antitrypsin (alpha 1AT) is a major protease inhibitor present in high concentrations in the plasma. Inheritance of alpha 1AT deficiency or null alleles (alleles associated with no detectable serum alpha 1AT) is associated with an increased risk for emphysema. In contrast to beta zero-thalassemia variants in which RNA splicing and promoter mutations constitute more than 40% of beta zero-thalassemia variants, all nine alpha 1AT null variants identified are the result of mutations involving the protein coding region of the alpha 1AT gene. During routine screening of individuals applying for enrollment in the USA alpha 1AT Deficiency Registry we identified an individual with emphysema and a Protease Inhibitor (PI*) type heterozygous for a novel alpha 1AT null allele. Direct DNA sequencing of this individual's alpha 1AT alleles demonstrated one normal and one novel allele, designated PI*QOwest, characterized by a single G-->T base substitution at position 1 of intron II, a highly conserved nucleotide position in vertebrate splice donor sites. Metabolic labeling of NIH-3T3 cells transfected with a plasmid vector containing an alpha 1AT minigene with the QOwest mutation demonstrated an absence of detectable immunoprecipitable alpha 1AT confirming that the G-->T mutation is responsible for the observed null phenotype. QOwest alpha 1AT minigene transfected cells expressed 25-100 fold less alpha 1AT mRNA than a normal control. DNA sequencing of polymerase chain reaction amplified mRNA obtained from transfected cells demonstrated the use of a cryptic splice site 84 bases upstream from the normal splice site.(ABSTRACT TRUNCATED AT 250 WORDS)

Compensatory growth in sheep and cattle. 1. Growth pattern and feed intake

Sheep and cattle often exhibit compensatory growth following nutritional restriction. Complete compensation, that is the same weight at the same age as non-restricted contemporaries, has often been observed in sheep but not in cattle. In this experiment the compensatory growth of sheep and cattle was measured after their nutrition had been restricted sufficiently to induce losses in body weight. The growth, feed intake and feed conversion efficiency of the compensating sheep and cattle, measured during re-alimentation, was compared to control animals fed ad libitium throughout the experiment. A high-quality diet was used to maximize the opportunity for compensatory growth. The cattle exhibited compensatory growth for the 11 months between re-alimentation and the end of the experiment, and were able to compensate completely. Compensatory growth did not persist as long in the sheep as in the cattle, and they remained lighter than the controls at the end of the experiment. During the first 12 weeks of re-alimentation there was no difference in the feed intake of the compensating and control animals in both species. Compensatory growth during this time was due to the greater efficiency of the compensating animals. After this initial 12 weeks the feed intake of the compensating animals increased, and the subsequent compensatory growth could be fully accounted for by greater feed intake. The greater persistence of compensatory growth in the cattle was due to their intake remaining elevated longer.

Compensatory growth in sheep and cattle. II. Changes in body composition and tissue weights

Compensatory growth can be due to increased protein deposition, reduced maintenance and greater feed intake. However, the contribution to and interaction between these mechanisms during compensatory growth is not clear. It was hypothesized that initial compensatory growth was due to reduced maintenance requirement and greater deposition of protein, after which compensatory growth was due to greater feed intake. Changes in the composition of sheep and cattle were measured during nutritional restriction and subsequent compensatory growth, and compared with the changes in control animals fed ad libitum throughout. At the end of the experiment the restricted cattle had compensated completely, and there was no difference in the body composition of the restricted and the control cattle. The restricted sheep did not compensate completely and were leaner than the control sheep. During nutritional restriction there was differential weight loss of carcase tissues in both the sheep and the cattle. The greatest losses were in the liver and the digestive tract in both species and in the skin of the sheep. It was concluded that the loss of these tissues reduced the maintenance requirement of the restricted animals and that the lowered maintenance requirement persisted during re-alimentation until these tissues had been fully repleted. Further, the repletion of these tissues required an increase in protein deposition, and it was a combination of these two mechanisms that was responsible for compensatory growth during the first 12 weeks of re-alimentation.

Comparative anti-inflammatory efficacy of topical corticosteroids with low glaucoma-inducing potential

Fluorometholone and clobetasone butyrate have been developed as ophthalmic corticosteroids because of their lesser potential to elevate intraocular pressure. Nevertheless, their primary use is the inhibition of an inflammatory response. Quantification of their anti-inflammatory effect in the rabbit cornea indicates that 0.1% fluorometholone and 0.1% clobetasone butyrate are effective, but weak, anti-inflammatory agents. An increase in concentration of fluorometholone to 0.25% failed to enhance its anti-inflammatory effectiveness significantly, while an increase in concentration of clobetasone butyrate to 0.5% did significantly increase its anti-inflammatory effect. As with all other corticosteroid bases studied to date, formulation of fluorometholone as an acetate derivative significantly increased its effectiveness, rendering it as effective as 1.0% prednisolone acetate, the most effective of commercially available ophthalmic corticosteroids.

Quantification of stromal destruction in the inflamed cornea

An intrastromal injection of endotoxin lipopolysaccharide (LPS) in one eye of New Zealand albino rabbits induced a prominent keratitis characterized clinically and microscopically by edema and infiltration. Polymorphonuclear leukocytes (PMNs) constituted the primary invading leukocytic element. Collagen synthesis was measured by pulsing the corneas with 3H-proline before inducing inflammation. The invasion of the cornea by leukocytes did not alter the conversion of proline to hydroxyproline significantly in the stroma during the 14-day observation period, signifying that there were only negligible changes in the rate of collagen synthesis. However, the percentage of total stromal protein represented by collagen (ie, collagen/total protein) was only 50% of that in comparable corneas receiving an injection of phosphate-buffered saline. Some animals were rendered leukopenic by intravenous nitrogen mustard before intrastromal LPS injection caused a less severe corneal inflammatory response, characterized microscopically by fewer infiltrating leukocytes. Similarly, in nonleukopenic rabbits, topical therapy with 1% prednisolone acetate markedly reduced the corneal inflammatory response which also was characterized by fewer invading leukocytes. In neither instance was there extreme collagen loss, suggesting that the loss of stromal collagen is related to PMN infiltration.

Effects of position changes on mixed venous oxygen saturation in patients after coronary revascularization

The purpose of this study was to investigate the effects of position changes on mixed venous oxygen saturation (SvO2) and to describe the mechanisms responsible for SvO2 changes reported to occur with position changes. The study was done from 4 to 8 hours after surgery in 34 patients after coronary artery bypass grafting. Subjects were put through a series of six position changes, including head of bed elevations and right and left lateral decubitus with return to supine between each. Each position was maintained for 30 minutes. SvO2, arterial oxygen saturation (SaO2), and oxygen consumption (VO2) were measured before and after each position change. Overall mean subject data demonstrated a decrease in SvO2 with each of the lateral position changes. The SvO2 did not drop below 60% in these mean data, and this drop returned to baseline by 5 minutes. There were no significant changes in the mean data for VO2 or SaO2. No significant correlation was found in the mean data between SvO2 and VO2 or SvO2 and SaO2 measurements. Trends were demonstrated in five specific cases that suggested a correlation between changes in SvO2 and changes in VO2 and SaO2. In conclusion, this study demonstrated that subjects were able to tolerate position changes with no clinically significant changes in SvO2, SaO2, or VO2.

Evaluation of the patient having cardiac surgery in the postoperative rewarming period

Ensuring adequate oxygen delivery to the tissues with respect to oxygen demand is the treatment goal in patients undergoing coronary artery surgery (CAS). In this study we examined changes in temperature, arterial oxygen saturation (SaO2), cardiac index (CI), oxygen consumption (VO2), and mixed venous oxygen saturation (SvO2) over the initial 4-hour rewarming period in 36 patients having CAS. When patients were admitted to the intensive care unit the mean temperature was 36.27 degrees C, and it increased to 37.50 degrees C; SaO2 was 97.67% at the beginning and end of the 4-hour period; CI was 2.88 L/min/m2 and rose to 3.00 L/min/m2; VO2 was high at 0.320 L/min on admission and remained high at 0.290 L/min at the end of the 4-hour rewarming period; and SvO2 was 70.83% initially and declined to 66.53% in the same period of time. Continuous SvO2 monitoring was valuable in the ongoing assessment and management of the patients in stable, mildly hypothermic condition after CAS during the 4-hour postoperative rewarming period.

The access of relevant information for solving problems

Two issues were investigated concerning the retrieval of recently acquired relevant information for solving riddle problems. First, although earlier research indicated that problem solvers often fail to retrieve relevant information unless they are explicitly informed of its relevance, Bowden (1985) suggested that uninformed subjects would benefit greatly from additional problem-solving time. In two experiments, we found that uninformed subjects solved more problems than did subjects who did not receive the information, but a simple model attributed this difference to these uninformed subjects "catching on" to the information's relevance after solving some problems. Second, the retrieval characteristics were examined by varying the proportion of problems for which clues were given. Informed subjects given clues for only half of the problems benefited (though perhaps not fully) from being informed, without incurring any cost from being misdirected on the unclued problems. The discussion focuses on some ways in which accessing relevant information may affect problem solving.

Alternative turnoff strategies for Kimberley beef cattle. 1. Live animal performance and carcass characteristics

In June 1980, 190 Kimberley Shorthorn steers from five properties in the Kimberley were divided into three age categories. Half were sent to Chapman Research Station (CRS) in the agricultural area of Western Australia and the remainder stayed at Ord Regeneration Research Station (ORRS) in the Kimberley. Animals in both locations grazed for either one or two pasture growing seasons and a third group was fed a concentrate ration based on grain after the first growing season. Cattle lost between 20-30 kg in handling and transport south which, together with the reduced initial grazing season, led to gains of only 50 kg while those in the north gained around 100 kg. In the second grazing season at both locations animals gained around 140 kg. Animals at ORRS laid down more fat than those at CRS. Animals fed on concentrate rations in the agricultural area grew significantly faster, but had poorer food conversion and were leaner compared with those fed in the Kimberley.

Effect of concurrent topical corticosteroid and NSAID therapy of experimental keratitis

The ability of suprofen, a nonsteroidal anti-inflammatory drug, and prednisolone acetate, a corticosteroid, to suppress polymorphonuclear leukocyte invasion of the rabbit cornea during an experimental keratitis was evaluated following topical ophthalmic administration of either drug alone or both drugs concurrently. Suprofen therapy initiated immediately after induction of inflammation was ineffective. However, if suprofen therapy was begun 48 hr prior to the induction of inflammation, the drug was effective. In contrast, prednisolone acetate therapy begun after the induction of inflammation was effective; 48 hr of pretreatment with the corticosteroid produced a marked increase in its therapeutic effect. When administered according to the same regimen, concurrent therapy with suprofen and prednisolone acetate was significantly more effective than treatment with either drug alone. This result was obtained irrespective of whether concurrent therapy was initiated prior to or after the inflammatory event.

Bioavailability and corneal anti-inflammatory effect of topical suprofen

The bioavailability in rabbit cornea and aqueous humor of an ophthalmic formulation of suprofen, a nonsteroidal anti-inflammatory drug, was evaluated following topical administration of a single dose to the eye. The drug penetrated rapidly into the uninflamed cornea with intact epithelium; highest levels occurred during the first 30 to 45 min after instillation and decreased thereafter. The bioavailability of suprofen in cornea and aqueous humor following administration of a 1.0% concentration was twice that produced by a 0.5% concentration of the drug. Topical application of multiple doses of suprofen failed to suppress polymorphonuclear leukocyte invasion of the cornea if treatment was started after the induction of inflammation. Suprofen therapy initiated prior to the induction of corneal inflammation and maintained into the post-inflammation period did produce a significant (P less than 0.01) decrease in the numbers of PMNs that invaded the inflamed cornea. There was no significant difference (P greater than 0.05) in the corneal anti-inflammatory effect achieved by the 0.5% and 1.0% concentrations of suprofen when administered according to this regimen.

Sandplain lupins (Lupinus cosentinii) as a summer feed for yearling steers

The response of 9-month-old Angus steers, grazing sandplain lupins during summer and autumn and fed oat and oat plus urea supplements, or grazing hay made from the lupins and fed no supplement, was studied in two experiments. In the first experiment there were 3.3 t DM/ha present at the start of grazing. Average daily weight changes over 84 days were -0.548, -0.274 and 0.333 kg/day (P<0.05) for steers fed 0, 1 and 2 kg oats/steer.day respectively. The steers grazing lupin hay averaged -0.417 kg/day. There were 8.4 t DM/ha present at the start of the second experiment and the daily weight changes by steers fed 0, 2 and 6 kg oats plus urea/head.day were - 0.012, 0.524 and 0.952 kg/day (P<0.05), respectively. The steers grazing lupin hay gained 0.215 kg/day. No obvious clinical signs of lupinosis were observed in either experiment. However, in the first experiment the lupins were toxic, liver damage occurred and lupinosis may have contributed to the lower growth rates. In both experiments steers not fed a supplement made compensatory weight gains during winter and spring, when all steers were run together on mixed clover-grass pasture.

Quantitation of herpes simplex virus in rabbit corneal epithelium

The authors have developed an objective method for quantitation of herpes simplex virus in the corneal epithelium of rabbits. At appropriate times postinfection, full-thickness rabbit corneas were removed by trephination and subjected to one cycle of freezing and thawing. The corneal epithelium was then disrupted by sonication. The amount of infectious virus recovered from sonicated specimens was determined by an in vitro plaque assay, providing a measure of the quantity of virus present during the acute stage of herpetic keratitis. Using this technique, the authors found that the mean virus titer was reduced from 1.5 X 10(5) plaque forming units (pfu) per cornea in control rabbits to less than 200 pfu per cornea in rabbits treated topically for 2 days with 1% trifluridine. In contrast, instillation of 1% prednisolone acetate resulted in the persistence of higher levels of virus (275 pfu) than those observed in control rabbits (3 pfu) 4 days after the cessation of therapy.

Prolongation of anti-inflammatory effect of prednisolone acetate. Influence of formulation in high-viscosity gel

Prednisolone acetate was formulated in a high-viscosity carboxypolymethylene gel at concentrations of 0.125% and 1.0%. The ability of these gel preparations to suppress inflammation in the cornea was assessed and compared with the antiinflammatory capabilities of conventional commercially available prednisolone acetate ophthalmic suspensions. When administered hourly, the gel formulations produced no greater anti-inflammatory effect than the conventional suspensions. However, the gel formulations were equal in effect to the suspensions and maintained their effects considerably longer than did the suspensions. When applied at intervals up to and including four hours, there was no falloff in effect; the gel demonstrated a level of anti-inflammatory effectiveness that could not be distinguished from hourly administration of the suspension.

Route of antibiotic administration in bacterial keratitis

The in vivo antibacterial effectiveness in the rabbit cornea of several antibiotics delivered by topical application, by periocular injection, and by intravenous (IV) inoculation was determined against Staphylococcus aureus and Pseudomonas aeruginosa. Topical instillation of antibiotic was highly effective in eliminating these organisms from the cornea. In contrast, despite a considerable increase in the quantity of antibiotic administered, we could demonstrate no statistically significant reduction in the number of viable staphylococcal or Pseudomonas organisms in the cornea when the antibiotic was given by periocular or by IV injection.

Metabolism of infused L(+)-lactate during exercise

1. The ability to metabolize lactate at rest and during exercise was studied in six male subjects by using a constant infusion of sodium l(+)-lactate at a rate of 0·05 mmol min−1 kg−1. Twenty minute periods of rest and exercise at two work rates were used, amounting to 25% and 50% of maximal O2 uptake (V̇o2 max.) in four subjects and 50% and 66% of V̇o2 max. in two subjects. Control measurements were made with saline infusion. In all studies a steady state in blood lactate was achieved.

2. At rest lactate infusion was associated with an increase of 3·51 mmol/l (± sd 0·70) in plasma lactate. The increase was smaller in exercise and in a given subject was the same at both work rates; plasma lactate was on average 1·21 mmol/l (±sd 1·11) higher during lactate infusion than the control measurement at the same power output. In one subject lactate values in exercise were unchanged by lactate infusion.

3. At rest lactate infusion was associated with an increase in O2 intake and CO2 output, the respiratory exchange ratio was unchanged, and plasma HCO−3 rose by 1·85 mmol/l.

4. During exercise lactate infusion was associated with a smaller and variable increase in O2 intake. CO2 output was less, the respiratory exchange ratio fell, and plasma HCO−3 rose by 6·1 mmol/l.

5. Exercise is accompanied by an increased capacity to metabolize lactate aerobically. Decreasing lactate metabolism appears to play no part in the increase in plasma lactate concentration with increasing exercise, at least to 66% of the maximal O2 intake.

Cyclic AMP formation and release by cultured bone cells stimulated with prostaglandin E2

PGE2 produced a marked and dose-related increase in cAMP content of cultured bone cells and in the release of cAMP into the incubation medium. The amount of cAMP released from the cells by PGE2 was proportional to the cellular concentration, and was dependent upon the time of incubation with PGE2. The cAMP levels released into the media increased slowly at a linear rate during a 60 min treatment with PGE2. This release was blocked by theophylline, probenecid, ouabain and dinitrophenol, suggesting that the release of cAMP was not a simple diffusive process and required energy. SC-19220 reduced the formation of cAMP more than the release, suggesting that the formation and the release may arise from separate events. Inability of D600 to inhibit PGE2-induced release of cAMP indicates that the release does not require calcium.