Willingness to vaccinate children against COVID-19 declined during the pandemic

OBJECTIVES

To document the level of vaccine hesitancy in caregivers' of children younger than 12 years of age over the course of the pandemic in Pediatric Emergency Departments (ED). Study design Ongoing multicenter, cross-sectional survey of caregivers presenting to 19 pediatric EDs in the USA, Canada, Israel, and Switzerland during first months of the pandemic (phase1), when vaccines were approved for adults (phase2) and most recently when vaccines were approved for children (phase3).

RESULTS

Willingness to vaccinate rate declined over the study period (59.7%, 56.1% and 52.1% in the three phases). Caregivers who are fully vaccinated, who have higher education, and those worried their child had COVID-19 upon arrival to the ED, were more likely to plan to vaccinate in all three phases. Mothers were less likely to vaccinate early in the pandemic, but this hesitancy attenuated in later phases. Older caregivers were more willing to vaccinate, and caregivers of older children were less likely to vaccinate their children in phase 3. During the last phase, willingness to vaccinate was lowest in those who had a primary care provider but did not rely on their advice for medical decisions (34%). Those with no primary care provider and those who do and rely on their medical advice, had similar rates of willingness to vaccinate (55.1% and 52.1%, respectively).

CONCLUSIONS

COVID-19 vaccine hesitancy is widespread and growing over time, and public health measures should further try to leverage identified factors associated with hesitancy in order to enhance vaccination rates among children.

Heme protects Pseudomonas aeruginosa and Staphylococcus aureus from calprotectin-induced iron starvation

Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic bacterial pathogens that cause severe infections in immunocompromised individuals and patients with cystic fibrosis. Both P. aeruginosa and S. aureus require iron to infect the mammalian host. To obtain iron, these pathogens may rely on siderophore-mediated ferric iron uptake, ferrous iron uptake, or heme uptake at different points during infection. The preferred iron source depends on environmental conditions, including the presence of iron-sequestering host-defense proteins. Here, we investigate how the presence of heme, a highly relevant iron source during infection, affects bacterial responses to iron withholding by the innate immune protein calprotectin (CP). Prior work has shown that P. aeruginosa is starved of iron in the presence of CP. We report that P. aeruginosa upregulates expression of heme uptake machinery in response to CP. Furthermore, we show that heme protects P. aeruginosa from CP-mediated inhibition of iron uptake and iron-starvation responses. We extend our study to a second bacterial pathogen, S. aureus, and demonstrate that CP also inhibits iron uptake and induces iron-starvation responses by this pathogen. Similarly to P. aeruginosa, we show that heme protects S. aureus from CP-mediated inhibition of iron uptake and iron-starvation responses. These findings expand our understanding of microbial responses to iron sequestration by CP and highlight the importance of heme utilization for bacterial adaptation to host iron-withholding strategies.

Retrograde signaling by a mtDNA-encoded non-coding RNA preserves mitochondrial bioenergetics

Alveolar epithelial type II (AETII) cells are important for lung epithelium maintenance and function. We demonstrate that AETII cells from mouse lungs exposed to cigarette smoke (CS) increase the levels of the mitochondria-encoded non-coding RNA, mito-RNA-805, generated by the control region of the mitochondrial genome. The protective effects of mito-ncR-805 are associated with positive regulation of mitochondrial energy metabolism, and respiration. Levels of mito-ncR-805 do not relate to steady-state transcription or replication of the mitochondrial genome. Instead, CS-exposure causes the redistribution of mito-ncR-805 from mitochondria to the nucleus, which correlated with the increased expression of nuclear-encoded genes involved in mitochondrial function. These studies reveal an unrecognized mitochondria stress associated retrograde signaling, and put forward the idea that mito-ncRNA-805 represents a subtype of small non coding RNAs that are regulated in a tissue- or cell-type specific manner to protect cells under physiological stress.

Report of the 2018-2019 Research and Graduate Affairs Committee

The 2018-2019 Research and Graduate Affairs Committee (RGAC) was charged with critically evaluating the leadership development support necessary for pharmacy researchers, including postdoctoral trainees, to develop the skills needed to build and sustain successful research programs and analyzing how well those needs are being met by existing programs both within AACP and at other organizations. The RGAC identified a set of skills that could reasonably be expected to provide the necessary foundation to successfully lead a research team and mapped these skills to the six domains of graduate education in the pharmaceutical sciences established by the 2016-2017 RGAC (Table 1). In addition, the RGAC identified competency in team science and the bench-to-bedside-to-beyond translational spectrum as being critical elements of research leadership. The universality of these skills and their value prompted the RGAC to make two related recommendations to AACP: [Table: see text] Recommendation 1: AACP should promote the development and use of strategies to ensure intentional and ongoing professional development, such as Individual Development Plans. Recommendation 2: AACP should explore collaborative research leadership development opportunities between faculty at research-intensive institutions and faculty at non-research-intensive institutions. The RGAC also examined programs available at AACP and other national organizations that could help pharmacy faculty develop foundational skills for research leadership (Table 2). The RGAC administered two surveys, one to administrators responsible for research at colleges and schools of pharmacy and one to faculty members at pharmacy schools, to gather information about training needs, programming and support available for research leadership development. Administrators and faculty agreed that research is important for career advancement for faculty, and almost all administrators reported their schools provide funds, release time and mentoring for participation in research career development. However, a lack of faculty awareness regarding programs and available support may be a barrier to participation. The RGAC therefore makes two recommendations and one suggestion related to AACP programming: [Table: see text] Recommendation 3: AACP should expand research leadership development opportunities building from existing programs such as ALFP and AACP Catalyst, with consideration placed on developing programs that promote collaborative research. Recommendation 4: AACP should collaborate with other professional organizations to expand research leadership development opportunities across the academy. Suggestion 1: Colleges and schools of pharmacy should take a proactive role in promoting and facilitating research leadership development for faculty. The RGAC separately examined the research leadership development needs of postdoctoral trainees, recognizing the distinct needs of trainees along the PhD or PhD/PharmD, PharmD/fellowship, and PharmD/residency paths. A review of organizational resources and opportunities for post-doctoral trainees available from national organizations, including AACP, was undertaken (Table 5). The RGAC sees an opportunity for AACP to foster research development of those trainees whose career track will likely be in clinical practice and makes one recommendation and one suggestion related to postdoctoral trainees: Recommendation 5: AACP should support and/or develop programs and activities for pharmacy residents seeking to transition into faculty positions to acquire the skills necessary to develop and lead research programs. Suggestion 2: Colleges and schools of pharmacy should include postdoctoral trainees with academic interests in research leadership development opportunities available to junior faculty. In addition, the RGAC proposed one policy statement that was adopted July 2019 by the AACP House of Delegates: Policy Statement: AACP recognizes the positive role that research leadership development can play in the success of early and mid-career faculty.

The human innate immune protein calprotectin induces iron starvation responses in Pseudomonas aeruginosa

Most microbial pathogens have a metabolic iron requirement, necessitating the acquisition of this nutrient in the host. In response to pathogen invasion, the human host limits iron availability. Although canonical examples of nutritional immunity are host strategies that limit pathogen access to Fe(III), little is known about how the host restricts access to another biologically relevant oxidation state of this metal, Fe(II). This redox species is prevalent at certain infection sites and is utilized by bacteria during chronic infection, suggesting that Fe(II) withholding by the host may be an effective but unrecognized form of nutritional immunity. Here, we report that human calprotectin (CP; S100A8/S100A9 or MRP8/MRP14 heterooligomer) inhibits iron uptake and induces an iron starvation response in Pseudomonas aeruginosa cells by sequestering Fe(II) at its unusual His₆ site. Moreover, under aerobic conditions in which the Fe(III) oxidation state is favored, Fe(II) withholding by CP was enabled by (i) its ability to stabilize this redox state in solution and (ii) the production and secretion of redox-active, P. aeruginosa-produced phenazines, which reduce Fe(III) to Fe(II). Analyses of the interplay between P. aeruginosa secondary metabolites and CP indicated that Fe(II) withholding alters P. aeruginosa physiology and expression of virulence traits. Lastly, examination of the effect of CP on cell-associated metal levels in diverse human pathogens revealed that CP inhibits iron uptake by several bacterial species under aerobic conditions. This work implicates CP-mediated Fe(II) sequestration as a component of nutritional immunity in both aerobic and anaerobic milieus during P. aeruginosa infection.

In vitro and in vivo characterization of three Cellvibrio japonicus glycoside hydrolase family 5 members reveals potent xyloglucan backbone-cleaving functions

BACKGROUND

Xyloglucan (XyG) is a ubiquitous and fundamental polysaccharide of plant cell walls. Due to its structural complexity, XyG requires a combination of backbone-cleaving and sidechain-debranching enzymes for complete deconstruction into its component monosaccharides. The soil saprophyte Cellvibrio japonicus has emerged as a genetically tractable model system to study biomass saccharification, in part due to its innate capacity to utilize a wide range of plant polysaccharides for growth. Whereas the downstream debranching enzymes of the xyloglucan utilization system of C. japonicus have been functionally characterized, the requisite backbone-cleaving endo-xyloglucanases were unresolved.

RESULTS

Combined bioinformatic and transcriptomic analyses implicated three glycoside hydrolase family 5 subfamily 4 (GH5_4) members, with distinct modular organization, as potential keystone endo-xyloglucanases in C. japonicus. Detailed biochemical and enzymatic characterization of the GH5_4 modules of all three recombinant proteins confirmed particularly high specificities for the XyG polysaccharide versus a panel of other cell wall glycans, including mixed-linkage beta-glucan and cellulose. Moreover, product analysis demonstrated that all three enzymes generated XyG oligosaccharides required for subsequent saccharification by known exo-glycosidases. Crystallographic analysis of GH5D, which was the only GH5_4 member specifically and highly upregulated during growth on XyG, in free, product-complex, and active-site affinity-labelled forms revealed the molecular basis for the exquisite XyG specificity among these GH5_4 enzymes. Strikingly, exhaustive reverse-genetic analysis of all three GH5_4 members and a previously biochemically characterized GH74 member failed to reveal a growth defect, thereby indicating functional compensation in vivo, both among members of this cohort and by other, yet unidentified, xyloglucanases in C. japonicus. Our systems-based analysis indicates distinct substrate-sensing (GH74, GH5E, GH5F) and attack-mounting (GH5D) functions for the endo-xyloglucanases characterized here.

CONCLUSIONS

Through a multi-faceted, molecular systems-based approach, this study provides a new insight into the saccharification pathway of xyloglucan utilization system of C. japonicus. The detailed structural-functional characterization of three distinct GH5_4 endo-xyloglucanases will inform future bioinformatic predictions across species, and provides new CAZymes with defined specificity that may be harnessed in industrial and other biotechnological applications.

Comprehensive functional characterization of the glycoside hydrolase family 3 enzymes from Cellvibrio japonicus reveals unique metabolic roles in biomass saccharification

Lignocellulose degradation is central to the carbon cycle and renewable biotechnologies. The xyloglucan (XyG), β(1→3)/β(1→4) mixed-linkage glucan (MLG) and β(1→3) glucan components of lignocellulose represent significant carbohydrate energy sources for saprophytic microorganisms. The bacterium Cellvibrio japonicus has a robust capacity for plant polysaccharide degradation, due to a genome encoding a large contingent of Carbohydrate-Active enZymes (CAZymes), many of whose specific functions remain unknown. Using a comprehensive genetic and biochemical approach, we have delineated the physiological roles of the four C. japonicus glycoside hydrolase family 3 (GH3) members on diverse β-glucans. Despite high protein sequence similarity and partially overlapping activity profiles on disaccharides, these β-glucosidases are not functionally equivalent. Bgl3A has a major role in MLG and sophorose utilization, and supports β(1→3) glucan utilization, while Bgl3B underpins cellulose utilization and supports MLG utilization. Bgl3C drives β(1→3) glucan utilization. Finally, Bgl3D is the crucial β-glucosidase for XyG utilization. This study not only sheds the light on the metabolic machinery of C. japonicus, but also expands the repertoire of characterized CAZymes for future deployment in biotechnological applications. In particular, the precise functional analysis provided here serves as a reference for informed bioinformatics on the genomes of other Cellvibrio and related species.

Cascading influence of inorganic nitrogen sources on DOM production, composition, lability and microbial community structure in the open ocean

Nitrogen frequently limits oceanic photosynthesis and the availability of inorganic nitrogen sources in the surface oceans is shifting with global change. We evaluated the potential for abrupt increases in inorganic N sources to induce cascading effects on dissolved organic matter (DOM) and microbial communities in the surface ocean. We collected water from 5 m depth in the central North Pacific and amended duplicate 20 liter polycarbonate carboys with nitrate or ammonium, tracking planktonic carbon fixation, DOM production, DOM composition and microbial community structure responses over 1 week relative to controls. Both nitrogen sources stimulated bulk phytoplankton, bacterial and DOM production and enriched Synechococcus and Flavobacteriaceae; ammonium enriched for oligotrophic Actinobacteria OM1 and Gammaproteobacteria KI89A clades while nitrate enriched Gammaproteobacteria SAR86, SAR92 and OM60 clades. DOM resulting from both N enrichments was more labile and stimulated growth of copiotrophic Gammaproteobacteria (Alteromonadaceae and Oceanospirillaceae) and Alphaproteobacteria (Rhodobacteraceae and Hyphomonadaceae) in weeklong dark incubations relative to controls. Our study illustrates how nitrogen pulses may have direct and cascading effects on DOM composition and microbial community dynamics in the open ocean.

Systems analysis in Cellvibrio japonicus resolves predicted redundancy of β-glucosidases and determines essential physiological functions

Degradation of polysaccharides forms an essential arc in the carbon cycle, provides a percentage of our daily caloric intake, and is a major driver in the renewable chemical industry. Microorganisms proficient at degrading insoluble polysaccharides possess large numbers of carbohydrate active enzymes (CAZymes), many of which have been categorized as functionally redundant. Here we present data that suggests that CAZymes that have overlapping enzymatic activities can have unique, non-overlapping biological functions in the cell. Our comprehensive study to understand cellodextrin utilization in the soil saprophyte Cellvibrio japonicus found that only one of four predicted β-glucosidases is required in a physiological context. Gene deletion analysis indicated that only the cel3B gene product is essential for efficient cellodextrin utilization in C. japonicus and is constitutively expressed at high levels. Interestingly, expression of individual β-glucosidases in Escherichia coli K-12 enabled this non-cellulolytic bacterium to be fully capable of using cellobiose as a sole carbon source. Furthermore, enzyme kinetic studies indicated that the Cel3A enzyme is significantly more active than the Cel3B enzyme on the oligosaccharides but not disaccharides. Our approach for parsing related CAZymes to determine actual physiological roles in the cell can be applied to other polysaccharide-degradation systems.

Structural and Functional Analysis of a Lytic Polysaccharide Monooxygenase Important for Efficient Utilization of Chitin in Cellvibrio japonicus

Cellvibrio japonicusis a Gram-negative soil bacterium that is primarily known for its ability to degrade plant cell wall polysaccharides through utilization of an extensive repertoire of carbohydrate-active enzymes. Several putative chitin-degrading enzymes are also found among these carbohydrate-active enzymes, such as chitinases, chitobiases, and lytic polysaccharide monooxygenases (LPMOs). In this study, we have characterized the chitin-active LPMO,CjLPMO10A, a tri-modular enzyme containing a catalytic family AA10 LPMO module, a family 5 chitin-binding module, and a C-terminal unclassified module of unknown function. Characterization of the latter module revealed tight and specific binding to chitin, thereby unraveling a new family of chitin-binding modules (classified as CBM73). X-ray crystallographic elucidation of theCjLPMO10A catalytic module revealed that the active site of the enzyme combines structural features previously only observed in either cellulose or chitin-active LPMO10s. Analysis of the copper-binding site by EPR showed a signal signature more similar to those observed for cellulose-cleaving LPMOs. The full-length LPMO shows no activity toward cellulose but is able to bind and cleave both α- and β-chitin. Removal of the chitin-binding modules reduced LPMO activity toward α-chitin compared with the full-length enzyme. Interestingly, the full-length enzyme and the individual catalytic LPMO module boosted the activity of an endochitinase equally well, also yielding similar amounts of oxidized products. Finally, gene deletion studies show thatCjLPMO10A is needed byC. japonicusto obtain efficient growth on both purified chitin and crab shell particles.

Sexual dimorphism in catasetum orchids: forcible pollen emplacement and male flower competition

Orchids of the Neotropical genus Catasetum have sexually dimorphic flowers; that is, male and female flowers are distinctly different in shape and color. Male flowers forcibly attach a large pollinarium onto euglossine bees. Euglossa bees leave the male flower in response to pollinarium emplacement by Catasetum ochraceum and subsequently avoid male but not female flowers. This evidence suggests that sexual dimorphism promotes pollination. The aversion of the bee to pollinarium attachment and its avoidance of male flowers thereafter apparently reflect competition among male flowers that probably evolved concurrently with sexual dimorphism. Among Catasetum species, the extent of dimorphism is correlated with the degree of apparent aversion caused by the male flower (weight of the pollinarium). Thus, aversive pollinarium emplacement can account for widespread sexual dimorphism in Catasetum and for interspecific variations in its expression.

In vitro synthesis of pre-proteins of vacuolar compartmented proteinase inhibitors that accumulate in leaves of wounded tomato plants

Two proteinase inhibitor proteins that are compartmented in leaf vacuoles (lysosomes) were synthesized in vitro. mRNA was isolated from 17-day-old expanding tomato leaves by extraction with chaotropic buffers followed by chromatography on oligo(dT)-cellulose and was translated with a rabbit reticulocyte lysate system. Preparations of mRNA from leaves of both wounded plants and unwounded plants directed the incorporation of equivalent amounts of label into trichloroacetic acid-precipitable proteins. Only mRNA from leaves of wounded plants directed label into proteins that could be immunoprecipitated with rabbit IgG specific for either inhibitor I or inhibitor II. These results indicate that the wound-induced accumulation of proteinase inhibitors I and II in leaf vacuoles is a result of the presence of translatable mRNA species not present in leaves of unwounded plants. Gel electrophoresis of the immunoprecipitates in NaDodSO(4)/urea/polyacrylamide gels revealed that inhibitors I and II were translated in vitro as precursors about 2000 daltons larger than the inhibitors found in leaves. The presence of the additional polypeptide sequences in the newly synthesized inhibitors indicates that the inhibitors are processed either during or after synthesis, and the presequences may be signal peptides that are part of the process of inhibitor transport into the vacuolar compartments of tomato leaf cells.

Control of a genetic regulatory network by a selector gene

The formation of many complex structures is controlled by a special class of transcription factors encoded by selector genes. It is shown that SCALLOPED, the DNA binding component of the selector protein complex for the Drosophila wing field, binds to and directly regulates the cis-regulatory elements of many individual target genes within the genetic regulatory network controlling wing development. Furthermore, combinations of binding sites for SCALLOPED and transcriptional effectors of signaling pathways are necessary and sufficient to specify wing-specific responses to different signaling pathways. The obligate integration of selector and signaling protein inputs on cis-regulatory DNA may be a general mechanism by which selector proteins control extensive genetic regulatory networks during development.

Concentrations of steroid hormones in layers and biopsies of chelonian egg yolks

The actions of circulating hormones, although relatively well understood for adults, are largely unknown for their developing embryos. Transfer of maternal hormones to the egg is known to occur in oviparous species, and recently the presence of hormonally heterogeneous yolk layers has been described in two avian species. To investigate the possibility of a similar phenomenon occurring in chelonian species, egg yolk layers were analyzed in the painted turtle (Chrysemys picta marginata) and the red-eared slider turtle (Trachemys scripta elegans), two species that exhibit temperature-dependent sex determination. There was a similar pattern of hormonally heterogeneous yolk layers in both species: concentrations of progesterone and testosterone were significantly higher in the external yolk layer while concentrations of 17beta-estradiol were significantly higher in the intermediate and internal layers. This pattern of hormone deposition concurs with previously published studies of plasma hormone profiles from females of temperate-zone turtle species. Yolks of freshly laid eggs were also sampled using a biopsy technique to examine the concordance of early yolk hormone concentrations and offspring sex. No relationship was found between yolk hormone concentrations and individual offspring sex. Previous work showing that maternally derived yolk estradiol concentrations are correlated with female-biased sex ratios was, however, replicated. These findings suggest that offspring sex is influenced, in part, by the maternal hormone environment.

Environmental sex determination in a reptile varies seasonally and with yolk hormones

Most hypotheses that have been put forward in order to explain the persistence of environmental sex determination (ESD) in reptiles assume a relatively fixed association of sex with temperature-induced phenotype and no maternal influence on offspring sex. Here we demonstrate the association of maternally derived yolk hormone levels with the offspring sex ratio and describe two new aspects of temperature-dependent sex determination (TSD), i.e. seasonal variation in both thermal response and yolk steroid levels. Eggs from painted turtles (Chrysemys picta) were incubated at 28 degrees C. The hatchling sex ratio at 28 degrees C (i.e. the phenotypic reaction norm for sex at 28 degrees C) shifted seasonally from ca. 72% male to ca. 76% female. Yolk oestradiol (E2) increased seasonally while testosterone (T) decreased. The proportion of males in a clutch decreased as E2 levels increased and the E2:T ratio increased. These new findings are discussed in relation to heritability and adaptive explanations for the persistence of ESD in reptiles. Maternally derived yolk hormones may provide a mechanism for the seasonal shift in the sex ratio which in turn may help explain the persistence of ESD in reptiles. They may also explain those clutches of other reptiles with TSD that fail to yield only males at maximally masculinizing conditions.

The effect of isoniazid on BCG-induced toxicity in patients with superficial bladder cancer

The use of bacillus Calmette-Guérin in the treatment of transitional cell cancer of the bladder has caused concern because of its associated adverse effects. We conducted a randomized prospective, double-blind, multicentre study to determine whether isoniazid prophylaxis could reduce BCG-induced toxicity without compromising its immunotherapeutic effects. Patients (n = 160) with histologically documented urothelial cancer (pTa-T1, pTis, G1-3) were treated with 6 weekly instillations of BCG Connaught strain, 81 mg, administered concomitantly with a 3-day course of isoniazid (300 mg o.d.) or placebo. Side-effects were recorded with each treatment and at follow-up. Of the patients treated with isoniazid, 19% remained free from side-effects, compared with 16% of the placebo group. Local side-effects confined to the bladder were significantly lower among those receiving isoniazid (35% vs. 48%, p < 0.01). Local side-effects together with systemic adverse effects such as fever, nausea or skin rash were experienced by 30% of patients in each arm. There were no differences in tumour recurrence between the two patient groups. Concomitant isoniazid reduces the local, but not the systemic side-effects of topically applied BCG without compromising the antitumour effect on superficial, transitional cell cancer of the bladder during a follow-up period that now exceeds 2 years.

Effects of testosterone on locomotor performance and growth in field-active northern fence lizards, Sceloporus undulatus hyacinthinus

The role of steroids in locomotor performance and growth was examined in free-living lizards. Male northern fence lizards (Sceloporus undulatus hyacinthinus) with experimentally elevated plasma testosterone concentrations had greater sprint speed (+24%) and burst stamina (+17%) than sham-implanted males after 14-23 d in the field. This enhanced performance was associated with significant energetic costs, as the testosterone-implanted lizards had reduced growth rates, and, in a companion experiment, field-active testosterone-implanted lizards had smaller fat-body masses than controls after just 3-4 wk. These results suggest that, in addition to influencing a variety of behavioral and morphological traits, testosterone may play an important role in the regulation of locomotor performance. Also, natural levels of locomotor performance may be constrained, in part, by associated costs of elevated plasma testosterone concentrations.

The challenge hypothesis and seasonal changes in aggression and steroids in male northern fence lizards (Sceloporus undulatus hyacinthinus)

The challenge hypothesis has been very successful in explaining patterns of testosterone secretion in response to social stimuli in avian species. However, there have been few studies in nonavian vertebrates. We tested the challenge hypothesis in male northern fence lizards (Sceloporus undulatus hyacinthinus). These males are highly territorial and nonparental. Consequently, the challenge hypothesis predicts that plasma testosterone concentrations will be insensitive to aggressive interactions. Testosterone concentrations indeed were not significantly affected by either a short (3-15 min) simulated territorial intrusion ("challenge") in June or a longer (50-60 min) intrusion in July. Levels of corticosterone were elevated in challenged males in the long, but not the short, intrusion. Challenged males displayed significantly more intense territorial behaviors than did unchallenged control males. The intensity of territorial behavior changed significantly across the active season and was positively related to testosterone concentrations. Thus, while testosterone concentrations do not appear to be involved in rapid changes in aggressive behavior in the fence lizard, they probably are important in larger-scale behavioral changes throughout the season.

Amlodipine overdose

OBJECTIVE

To report a nonfatal intentional overdose of amlodipine.

CASE SUMMARY

A 42-year-old woman with a history of hypertension reported ingesting 50-100 mg amlodipine besylate and at least 40 ounces of beer in a suicide attempt. The patient's symptoms were mild; BP ranged from 79/50 to 113/76 mm Hg and HR from 92 to 129 beats/min (sinus tachycardia). Laboratory studies revealed normoglycemia, mild metabolic acidosis, mild hypocalcemia, blood ethanol concentration of 263 mmol/L, and a serum amlodipine concentration of 88 ng/mL (normal 3-11) 2.5 hours after ingestion. Therapy included activated charcoal, whole bowel irrigation, and intravenous NaCl 0.9%. After receiving 1.5 L of NaCl 0.9%, the patient developed signs of mild pulmonary edema that resolved over several hours without intervention. A serum amlodipine concentration obtained 35 hours later was 79 mg/mL. The patient was discharged on day 2 in good condition.

DISCUSSION

In this case, an amlodipine overdose was associated with sustained hypotension and sinus tachycardia, as well as transient pulmonary edema following relatively low-volume fluid replacement. A previously published report described an amlodipine overdose that was fatal due to refractory hypotension and was complicated by concomitant oxazepam overdose.

CONCLUSIONS

Amlodipine overdose produces prolonged hemodynamic effects and may lead to pulmonary edema. Due to a long elimination half-life and delayed onset of effects, patients with amlodipine overdose should receive aggressive decontamination therapy and may require extended clinical monitoring and supportive care if they are hemodynamically unstable.

Comparison of the test-retest reliability of the Work Box using three administrative methods

OBJECTIVE

The purpose of this study was to compare the test-retest reliability of three administrative methods of the Work Box: (a) the original instructions, (b) a revised version of the original instructions, and (c) another revised version that was based on suggestions made by authors of the first two versions of the instructions.

METHOD

Sixty subjects without disabilities were randomly grouped so that 20 subjects were tested per administrative method. The assessment was administered to each subject on two occasions, with a 7-day to 14-day period between tests. Scores were recorded as time in seconds, and intraclass correlation coefficients (ICCs) were used to calculate the reliability.

RESULTS

The ICCs for assembly, disassembly, and total scores were .589, .604, and .654, respectively, for the original instructions; .424, .572, and .545 for the revised instructions; and .781, .579, .717 for the second revised instructions. Reliability was found to be higher for men than for women and for subjects who claimed to have more rather than less experience in similar manual dexterity tasks.

CONCLUSIONS

On the basis of the reliability of each administrative method and comments made by subjects about their understanding of the instructions, the second revised version of the instructions is recommended as the standard method. The results also indicate that the assessment is most appropriate for a population of men with manual dexterity experience. With further standardization, the Work Box could be a valuable assessment tool for therapists working in industrial rehabilitation settings.

The planning process in occupational therapy: perceptions of adult rehabilitation patients

OBJECTIVES

The purpose of this study was to learn about (a) adult physical rehabilitation patients' perceptions of their involvement in the treatment planning process (goal setting, treatment planning, outcome evaluation), (b) their valuation of occupational therapy, and (c) how they would describe their interpersonal relationships with their occupational therapists.

METHOD

Fifteen subjects who had received occupational therapy were interviewed. The transcripts were independently and jointly reviewed by the authors to answer five research questions.

RESULTS

Most of the subjects indicated that they had been involved in occupational therapy goal setting; treatment planning; and outcome evaluation, albeit this indication was weak. They also valued the occupational therapy services they received. Eight described positive interpersonal interactions with their therapists, and seven provided no information.

CONCLUSION

Patients receiving occupational therapy services are involved in goal setting, treatment planning, and outcome evaluations; however, their involvement varies and can be difficult for them to identify and describe. Because of increasing societal emphasis on patient rights and participation (e.g., consumerism, health professions standards, health care accreditation criteria, health care legislation) and the likelihood that health care funding will be used for services linked to patient goals, occupational therapy practitioners could become more overt and systematic in involving patients in the planning process. Increasing patient involvement in planning may result in more individualized treatment and more effective use of health care dollars.

Analysis of Hox gene expression in the chick limb bud

The vertebrate Hox genes have been shown to be important for patterning the primary and secondary axes of the developing vertebrate embryo. The function of these genes along the primary axis of the embryo has been generally interpreted in the context of positional specification and homeotic transformation of axial structures. The way in which these genes are expressed and function during the development of the secondary axes, particularly the limb, is less clear. In order to provide a reference for understanding the role of the Hox genes in limb patterning, we isolated clones of 23 Hox genes expressed during limb development, characterized their expression patterns and analyzed their regulation by the signalling centers which pattern the limb. The expression patterns of the Abd-B-related Hoxa and Hoxd genes have previously been partially characterized; however, our study reveals that these genes are expressed in patterns more dynamic and complex than generally appreciated, only transiently approximating simple, concentric, nested domains. Detailed analysis of these patterns suggests that the expression of each of the Hoxa and Hoxd genes is regulated in up to three independent phases. Each of these phases appears to be associated with the specification and patterning of one of the proximodistal segments of the limb (upper arm, lower arm and hand). Interestingly, in the last of these phases, the expression of the Hoxd genes violates the general rule of spatial and temporal colinearity of Hox gene expression with gene order along the chromosome. In contrast to the Abd-B-related Hoxa and Hoxd genes, which are expressed in both the fore and hind limbs, different sets of Hoxc genes are expressed in the two limbs. There is a correlation between the relative position of these genes along the chromosome and the axial level of the limb bud in which they are expressed. The more 3′ genes are expressed in the fore limb bud while the 5′ genes are expressed in the hind limb bud; intermediate genes are transcribed in both limbs. However, there is no clear correlation between the relative position of the genes along the chromosome and their expression domains within the limb. With the exception of Hoxc-11, which is transcribed in a posterior portion of the hind limb, Hoxc gene expression is restricted to the anterior/proximal portion of the limb bud. Importantly, comparison of the distributions of Hoxc-6 RNA and protein products reveals posttranscriptional regulation of this gene, suggesting that caution must be exercised in interpreting the functional significance of the RNA distribution of any of the vertebrate Hox genes. To understand the genesis of the complex patterns of Hox gene expression in the limb bud, we examined the propagation of Hox gene expression relative to cell proliferation. We find that shifts in Hox gene expression cannot be attributed to passive expansion due to cell proliferation. Rather, phase-specific Hox gene expression patterns appear to result from a context-dependent response of the limb mesoderm to Sonic hedgehog. Sonic hedgehog (the patterning signal from the Zone of Polarizing Activity) is known to be able to activate Hoxd gene expression in the limb. Although we find that Sonic hedgehog is capable of initiating and polarizing Hoxd gene expression during both of the latter two phases of Hox gene expression, the specific patterns induced are not determined by the signal, but depend upon the temporal context of the mesoderm receiving the signal. Misexpression of Sonic hedgehog also reveals that Hoxb-9, which is normally excluded from the posterior mesenchyme of the leg, is negatively regulated by Sonic hedgehog and that Hoxc-11, which is expressed in the posterior portion of the leg, is not affected by Sonic hedgehog and hence is not required to pattern the skeletal elements of the lower leg.

Sonic hedgehog is an endodermal signal inducing Bmp-4 and Hox genes during induction and regionalization of the chick hindgut

Reciprocal inductive signals between the endoderm and mesoderm are critical to vertebrate gut development. Sonic hedgehog encodes a secreted protein known to act as an inductive signal in several regions of the developing embryo. In this report, we provide evidence to support the role of Sonic hedgehog and its target genes Bmp-4 and the Abd-B-related Hox genes in the induction and patterning the chick hindgut. Sonic is expressed in the definitive endoderm at the earliest stage of chick gut formation. Immediately subjacent to Sonic expression in the caudal endoderm is undifferentiated mesoderm, later to become the visceral mesoderm of the hindgut. Genes expressed within this tissue include Bmp-4 (a TGF-beta relative implicated in proper growth of visceral mesoderm) and members of the Abd-B class of Hox genes (known regulators of pattern in many aspects of development). Using virally mediated misexpression, we show that Sonic hedgehog is sufficient to induce ectopic expression of Bmp-4 and specific Hoxd genes within the mesoderm. Sonic therefore appears to act as a signal in an epithelial-mesenchymal interaction in the earliest stages of chick hindgut formation. Gut pattern is evidenced later in gut morphogenesis with the presence of anatomic boundaries reflecting phenotypically and physiologically distinct regions. The expression pattern of the Abd-b-like Hox genes remains restricted in the hindgut and these Hox expression domains reflect gut morphologic boundaries. This finding strongly supports a role for these genes in determining the adult gut phenotype. Our results provide the basis for a model to describe molecular controls of early vertebrate hindgut development and patterning. Expression of homologous genes in Drosophila suggest that aspects of gut morphogenesis may be regulated by similar inductive networks in the two organisms.

Involvement of adult rehabilitation patients in setting occupational therapy goals

OBJECTIVE

This preliminary study was designed to determine whether occupational therapists involve patients and their families in a goal-setting process and, if so, to identify the methods used.

METHOD

Thirty registered occupational therapists practicing in adult physical rehabilitation settings were audiotaped during an initial evaluation. Researchers reviewed corresponding documentation and interviewed each subject. Twenty-three patient and family involvement criteria were generated from standards developed by accreditation commissions and health care professions.

RESULTS

Data revealed that although subjects did involve patients and families in a goal-setting process, a number of criteria were not attempted, thus much potential for involvement was unrealized. Subjects with scores above and below one standard deviation from the mean were identified to determine which patient participation criteria had the highest discrepancies. Discrepancies included (a) verbal preparation of the patient and family for initial and ongoing treatment, purposes and procedures of evaluation and treatment, and potential outcomes of treatment, (b) attempts to elicit the patient's concerns, and (c) collaboration with the patient to establish treatment goals.

CONCLUSION

Factors that might have influenced subjects' use of a patient participation approach included the application of a specific theory or technique, time constraints, patient's age, and assumptions about the patient's cognitive status.

Hox genes and the evolution of vertebrate axial morphology

A common form of evolutionary variation between vertebrate taxa is the different numbers of segments that contribute to various regions of the anterior-posterior axis; cervical vertebrae, thoracic vertebrae, etc. The term ‘transposition’ is used to describe this phenomenon. Genetic experiments with homeotic genes in mice have demonstrated that Hox genes are in part responsible for the specification of segmental identity along the anterior-posterior axis, and it has been proposed that an axial Hox code determines the morphology of individual vertebrae (Kessel, M. and Gruss, P. (1990) Science 249, 347–379). This paper presents a comparative study of the developmental patterns of homeobox gene expression and developmental morphology between animals that have homologous regulatory genes but different morphologies. The axial expression boundaries of 23 Hox genes were examined in the paraxial mesoderm of chick, and 16 in mouse embryos by in situ hybridization and immunolocalization techniques. Hox gene anterior expression boundaries were found to be transposed in concert with morphological boundaries. This data contributes a mechanistic level to the assumed homology of these regions in vertebrates. The recognition of mechanistic homology supports the historical homology of basic patterning mechanisms between all organisms that share these genes.

Sonic hedgehog and Fgf-4 act through a signaling cascade and feedback loop to integrate growth and patterning of the developing limb bud

Proper limb growth and patterning requires signals from the zone of polarizing activity in the posterior mesoderm and from the overlying apical ectodermal ridge (AER). Sonic hedgehog and Fgf-4, respectively, have recently been identified as candidates for these signals. We have dissected the roles of these secreted proteins in early limb development by ectopically regulating their activities in a number of surgical contexts. Our results indicate that Sonic hedgehog initiates expression of secondary signaling molecules, including Bmp-2 in the mesoderm and Fgf-4 in the ectoderm. The mesoderm requires ectodermally derived competence factors, which include Fgf-4, to activate target gene expression in response to Sonic hedgehog. The expression of Sonic hedgehog and Fgf-4 is coordinately regulated by a positive feedback loop operating between the posterior mesoderm and the overlying AER. Taken together, these data provide a basis for understanding the integration of growth and patterning in the developing limb.

Research note: the effect of organic acids on Salmonella contamination originating from mouse fecal pellets

Laboratory mice were inoculated with a nalidixic acid and novobiocin-resistant strain of Salmonella typhimurium. Contaminated fecal pellets were harvested 2 days postinoculation. Each half of a fecal pellet was found to contain equal numbers of Salmonella on a per weight basis. When separate halves were placed into a poultry feed, either treated or untreated, with an organic acid mixture (SAL CURB), the treatment was able to significantly (P < .001) reduce Salmonella contamination of the feed by almost two log orders per gram when compared with the untreated control.

Temperature-dependent sex determination in the leopard gecko, Eublepharis macularius

The leopard gecko, Eublepharis macularius, has temperature-dependent sex determination (TSD). Previous reports have shown that females are produced predominantly at cool incubation temperatures and males are produced predominantly at warm incubation temperatures (Pattern Ib). We report here that incubation at even higher temperatures (34 and 35 degrees C) produces mostly females (Pattern II). The lethal maximum constant incubation temperature for this species appears to be just above 35 degrees C. Although a previous study indicated that females from a warm incubation temperature (32 degrees C) failed to lay eggs, we found that 12 of 14 mature females incubated at 32.5 degrees C, and 5 of 6 mature females incubated at 34 degrees C produced fertile eggs and viable hatchlings.

Strategies of mold control in dairy feeds

Mold growth can occur in dairy feeds only when nutrients are available, correct temperatures exist, oxygen is present, and unbound water is available. Because elimination of any one of these four factors prevents mold growth, management of feed that accounts for these elements is essential. Use of multiple ingredient mold inhibitors recently has become another tool for affecting successful microbiological control of feed.

A system for involving patients in program planning

Although standards exist that require occupational therapists and other health care professionals to include patients in the treatment planning process, our observations lead us to believe that patient involvement is not being maximized. The Patient Participation System allows therapists to actively involve patients in a systematic goal-setting process. The initial results of the use of this system indicate that patients can be effectively involved in establishing personalized, specific goals; identifying outcomes; and evaluating treatment effectiveness.

Use of a most probable number method modified with a deoxyribonucleic probe to monitor control by food preservatives of natural Salmonella contamination in animal meat meals

A most probable number (MPN) technique using a DNA probe was developed for determination of Salmonella in naturally contaminated meat meals. The method eliminated the need for 180 selective plates and 75 selective tubes and saved 27 h when compared with a traditional technique; yet it still yielded identical MPN of Salmonella per 100 g in five naturally contaminated samples. The method was used to monitor the effect of a commercial food preservative (Sal Curb) at 0, .25, .50, 1.0, and 2.0% in meat meals with initial contaminations of 1,100, 93, or 7 MPN organisms/100 g. The preservative greatly reduced MPN in the 1,100 and 93 MPN samples in a time and dose-dependent manner, but in the sample with 7 MPN organisms/100 g of material, it resulted in 0 MPN organisms per 100 g after 24 h at all levels tested.

Incidence of molds and mycotoxins in commercial animal feed mills in seven midwestern states, 1988-1989

A total of 82 feed manufacturers located within seven midwestern states (Iowa, Nebraska, Minnesota, Illinois, Indiana, Ohio, Michigan) participated in a survey of mold and mycotoxin contamination of corn. Samples were submitted from a composite of the grading samples taken from each incoming load of corn. The survey was initiated in July 1988. During the 12-mo period, moisture content of the corn samples upon receipt at the laboratory ranged from 10.5 to 13.3%. The greatest variation occurred in the springtime. Iowa's corn samples were driest (11.2%), and samples submitted from Ohio were wettest (12.8%). Mold counts averaged 2.63 x 10(4) per gram during the year. The predominant mold found was Fusarium sp. Samples were checked by black light and averaged 25.4% positive during the period. When assayed for mycotoxins, 19.5% of the samples were positive for at least one of the following: aflatoxin, zearalenone, T2 toxin and deoxynivalenol (vomitoxin). Aflatoxin and T2 toxin made up the majority of these samples containing toxin. The highest incidence of mycotoxin-contaminated corn (48%) occurred in samples submitted in July of 1988. Over the 12-mo period, the highest mycotoxin contamination occurred in Iowa, Illinois and Michigan. When samples were subjected to 90% relative humidity and 32 degrees C, an average of 3.9 d was required for mold growth to appear. After incubation, 24.7% of the samples contained one of the four toxins. The data indicate that mold and mycotoxin contamination of mixed samples of corn is widespread, even in the midwestern corn belt of the U.S.

Adult physical dysfunction content in professional curricula

This study examined the content of occupational therapy professional curricula as it pertains to adult physical dysfunction and the opinions and perceptions of faculty responsible for this content area. Survey results from 28 of 66 academic institutions offering professional-level education were received and analyzed. A great diversity in content and emphasis was reflected in the areas of medical conditions, general approaches to evaluation and treatment, specific evaluations, and specific treatment techniques and modalities. Most of the respondents were pleased with students' performances in physical dysfunction Level II fieldwork, believed that course work was applicable to local clinical settings, and agreed that courses were constantly changing to reflect evolving occupational therapy theory. Approximately 30% of the respondents believed that they had inadequate time to prepare students for entry-level practice, and about half agreed that their department had the necessary equipment to teach evaluation and treatment content.

Germ line p53 mutations in a familial syndrome of breast cancer, sarcomas, and other neoplasms

Familial cancer syndromes have helped to define the role of tumor suppressor genes in the development of cancer. The dominantly inherited Li-Fraumeni syndrome (LFS) is of particular interest because of the diversity of childhood and adult tumors that occur in affected individuals. The rarity and high mortality of LFS precluded formal linkage analysis. The alternative approach was to select the most plausible candidate gene. The tumor suppressor gene, p53, was studied because of previous indications that this gene is inactivated in the sporadic (nonfamilial) forms of most cancers that are associated with LFS. Germ line p53 mutations have been detected in all five LFS families analyzed. These mutations do not produce amounts of mutant p53 protein expected to exert a trans-dominant loss of function effect on wild-type p53 protein. The frequency of germ line p53 mutations can now be examined in additional families with LFS, and in other cancer patients and families with clinical features that might be attributed to the mutation.

p53 functions as a cell cycle control protein in osteosarcomas

Mutations in the p53 gene have been associated with a wide range of human tumors, including osteosarcomas. Although it has been shown that wild-type p53 can block the ability of E1a and ras to cotransform primary rodent cells, it is poorly understood why inactivation of the p53 gene is important for tumor formation. We show that overexpression of the gene encoding wild-type p53 blocks the growth of osteosarcoma cells. The growth arrest was determined to be due to an inability of the transfected cells to progress into S phase. This suggests that the role of the p53 gene as an antioncogene may be in controlling the cell cycle in a fashion analogous to the check-point control genes in Saccharomyces cerevisiae.

The dosimetric properties of an intraoperative radiation therapy applicator system for a Mevatron-80

An applicator system for intraoperative radiation therapy has been fabricated which does not require physical docking with the accelerator. A dosimetric study has been completed which documents the properties of this system for a variety of electron beam energies, applicator sizes, collimator settings, both primary and secondary, and source-surface distance (SSD) settings. Sensitivity of the system to common misalignment errors was also determined. Results indicate (a) applicator leakage of less than 5%, (b) beam flatness to within plus or minus 5% at the dMAX with a single primary collimator setting, (c) smooth changes in output with cone size, beam energy and SSD, and (d) negligible changes in dose distributions within alignment errors permitted by the system.

Effect of chemical treatment of poultry feed on survival of Salmonella

After treatment with a chemical preservative [Myco Curb (Kemin Industries, Des Moines, IA) at .25, .5, .75, or 1.0%], sterilized commercial poultry feed was contaminated with either Salmonella typhimurium ATCC 6994 or with a strain isolated from commercial broiler carcasses. All treatments resulted in the elimination of detectable Salmonella from heavily contaminated feed within 72 h and from lightly contaminated feed within 24 h. Nonsterilized feed showed similar results. Commercial feed fed to broilers for 56 days and inoculated with Salmonella daily for Days 35 to 56 was treated with the chemical preservative at .5 and 1.0% for the last 7 days. Treatment resulted in a reduction of the number of fecal and intestinal samples positive for Salmonella, demonstrating elimination of Salmonella in the feed by use of the feed preservative.

Rectal v. intravenous administration of indomethacin in the treatment of renal colic

Rectal administration of 100 mg indomethacin in solution had as good, and almost as rapid, an effect on renal colic as 50 mg given intravenously. Side effects were significantly fewer with the rectal than with the intravenous route.

Priapism in a patient with endometrioid prostatic carcinoma. A case report

A case of endometrioid carcinoma of the prostate is reported in which the initial symptom was hematuria. The patient slowly developed a painless priapism, and the tumor ultimately became generalized despite orchiectomy.

Ornithine decarboxylase activity and polyamine content in normal renal tissue and in renal carcinoma

Ornithine decarboxylase (ODC) activity and contents of putrescine, spermidine and spermine were determined in cortical and medullary tissue and clear cell tumours in human kidneys. Medullary ODC activity was 75 +/- 9% (n = 6; p less than 0.05) of the respective cortical value. The ODC activity in renal tumours varied considerably but did not differ significantly from the respective cortical values. Similar concentrations of putrescine were found in cortex and medulla, but a 5-fold increase was found in the tumours (p less than 0.02). Significantly lower values (p less than 0.01) of spermidine and spermine were found in medulla when compared to cortex. No significant change was found for these amines in the carcinomas when compared with corresponding cortical tissue.

Automatic prediction of platelet utilization by time series analysis in a large tertiary care hospital

The authors investigated the potential of various time series models to aid in the prediction of platelet utilization patterns at the authors' institution. During a seven-week feasibility study, prediction accuracy of time series models was slightly inferior to that of an experienced platelet transfusion coordinator. The models that adjusted for day-of-the-week variability were superior to simpler models in a prospective evaluation over a three-month period. Conversion to a time series model for platelet utilization prediction has resulted in significant savings in personnel costs for management of platelet concentrate inventory in the blood bank. Outdate rates have been lower than those achieved by the platelet transfusion coordinator, with no sacrifice in availability occurring during the evaluation period.

Analytic calculation of electron beam isodose distributions

Analytical techniques have been developed to generate electron beam isodose distributions from a modest set of experimental data. These techniques include (1) development of a compact yet powerful linear least-squares optimization program with a graphic display of the results, (2) coordinate transformations to allow straightforward fitting of the isodose distributions with simple polynomial functions, and (3) accurate interpolation methods to allow production of treatment planning dose matrices. The program, written in FORTRAN, has been implemented on a minicomputer and uses the standard peripherals of a commercially available treatment planning system (AECL TP-11). The computer-generated isodose and central-axis distributions correspond very closely with the data for electron energies from 5 to 20 MeV and for all field sizes.

Regulation of Proteinase Inhibitor Synthesis in Tomato Leaves : IN VITRO SYNTHESIS OF INHIBITORS I AND II WITH mRNA FROM EXCISED LEAVES INDUCED WITH PIIF (PROTEINASE INHIBITOR INDUCING FACTOR)

Messenger RNA was isolated from young excised tomato leaves, induced to accumulate proteinase Inhibitors I and II with the proteinase inhibitor inducing factor (PIIF), and translated in vitro in a rabbit reticulocyte lysate system. Translatable messenger RNAs specific for Inhibitors I and II were present in PIIF-induced leaves but were not present without PIIF induction. The nascent in vitro-synthesized inhibitors migrated with an apparent molecular weight 2,000 to 3,000 daltons larger than that of the two inhibitors isolated from leaves. The molecular weights of the preinhibitors were identical whether translated from mRNA from PIIF-induced leaves or translated from mRNA isolated from wounded leaves. Incubation of excised PIIF-induced plants in CO(2)-free air doubled the rate of in vivo synthesis of Inhibitor I over that in normal air (Ryan CA 1977 Biochem Biophys Res Commun 77: 1004-1008) but did not affect the rate of in vivo Inhibitor II accumulation. The rate of incorporation of (35)SO(4) (2-) into soluble proteins was 70% less when leaves were incubated in CO(2)-free air rather than normal air. Messenger RNA isolated from PIIF-induced plants incubated in the presence or absence of CO(2) was translated in vitro. The amount of in vitro-translatable mRNA present for each inhibitor (per microgram total mRNA) was the same in leaves incubated in either atmosphere. Therefore, the increased rate of synthesis and accumulation of Inhibitor I in a CO(2)-free atmosphere does not appear to result from an increased level of mRNA but appears to be controlled at a posttranscriptional level.

N-acetyltransferase phenotype and risk in urinary bladder cancer: approaches in molecular epidemiology. Preliminary results in Sweden and Denmark

A variable but often significant proportion of urinary bladder cancer in urban areas can be attributed to occupational and cultural (cigarette smoking) situations associated with exposures to various arylamines. The variable N-acetylation of carcinogenic arylamines by human hepatic enzyme systems, the known genetic regulation and polymorphic distribution of this enzyme activity in humans, and the known enhanced susceptibility of individuals with the genetically-distinct "slow acetylator" phenotype to various arylamine toxicities, has prompted examination of possible correlations between N-acetyltransferase phenotype and urinary bladder cancer risk in rural and urban populations. In this context, N-acetylation is viewed as a component of detoxication pathways with respect to arylamine bladder carcinogenesis. In preliminary utilizations of this approach, a population of urban urinary bladder cancer patients from Copenhagen, Denmark displayed a 13% excess (p = 0.065) of individuals with the slow acetylator phenotype (46/71 = 64.8%) when compared to a Danish control population (38/74 = 51.4%). These data are consistent with the possibility that arylamines may play an etiological role in bladder cancer in this locale and that slow acetylator individuals may be at higher relative risk (1.74) than rapid acetylator individuals. As 95% of patients reported histories of smoking, it was not possible to isolate and examine smoking factors. In contrast, a population of rural urinary bladder cancer patients from Lund, Sweden, where bladder cancer incidence (20/100,000) (1971) is lower than in Copenhagen (43.8/100,000) (1968-72), no difference in slow acetylator distribution was observed between bladder cancer (80/115 = 69.6%) and Swedish control (79/118 = 66.9%) populations, indicating a relative lack of involvement of arylamines in the etiology of rural bladder cancer. Populations of "spontaneous" bladder cancer patients would be expected to contain variable portions of disease related to arylamine exposure and would be less likely to display a detectable correlation than would an industrial population with documentable arylamine exposure. Consequently, confirmation of this hypothesis is being pursued by examination of industrial populations in an effort to obtain an empirical estimate of relative risk for slow and rapid acetylator phenotypes. These studies involve exposure-matched workmen both with and without bladder cancer.