Evaluation of ChatGPT for Pelvic Floor Surgery Counseling

IMPORTANCE

Large language models are artificial intelligence applications that can comprehend and produce human-like text and language. ChatGPT is one such model. Recent advances have increased interest in the utility of large language models in medicine. Urogynecology counseling is complex and time-consuming. Therefore, we evaluated ChatGPT as a potential adjunct for patient counseling.

OBJECTIVE

Our primary objective was to compare the accuracy and completeness of ChatGPT responses to information in standard patient counseling leaflets regarding common urogynecological procedures.

STUDY DESIGN

Seven urogynecologists compared the accuracy and completeness of ChatGPT responses to standard patient leaflets using 5-point Likert scales with a score of 3 being "equally accurate" and "equally complete," and a score of 5 being "much more accurate" and much more complete, respectively. This was repeated 3 months later to evaluate the consistency of ChatGPT. Additional analysis of the understandability and actionability was completed by 2 authors using the Patient Education Materials Assessment Tool. Analysis was primarily descriptive. First and second ChatGPT queries were compared with the Wilcoxon signed rank test.

RESULTS

The median (interquartile range) accuracy was 3 (2-3) and completeness 3 (2-4) for the first ChatGPT query and 3 (3-3) and 4 (3-4), respectively, for the second query. Accuracy and completeness were significantly higher in the second query (P < 0.01). Understandability and actionability of ChatGPT responses were lower than the standard leaflets.

CONCLUSIONS

ChatGPT is similarly accurate and complete when compared with standard patient information leaflets for common urogynecological procedures. Large language models may be a helpful adjunct to direct patient-provider counseling. Further research to determine the efficacy and patient satisfaction of ChatGPT for patient counseling is needed.

Pathologic, immunologic, and clinical analysis of the microsatellite instability phenotype in endometrial carcinoma

The objective of this study was to determine if quantifying the microsatellite instability (MSI) phenotype could serve as a biomarker for clinical and immunologic features of deficient mismatch repair (dMMR) endometrial cancer (EC). Patients with EC undergoing hysterectomy whose tumors demonstrated dMMR were included. Immunohistochemistry (IHC) of mismatch repair proteins and polymerase chain reaction analysis of NR27, BAT25, BAT26, NR24, and NR21 microsatellite loci were performed on each case. The MSI phenotype was quantified by subtracting the number of nucleotides of each microsatellite in tumor tissue from the corresponding microsatellite in paired normal tissue and summing the absolute differences. This was termed marker sum (MS) and is a novel quantification. Tumor-infiltrating lymphocytes (TILs) were identified by IHC for CD3, CD4, and CD8 and quantified with digital image analysis. Tumor infiltration of lymphocytes and clinical characteristics were stratified by MS. Four hundred fifty-nine consecutive patients with dMMR EC were analyzed. MS ranged from 1 to 32. Post hoc, 2 cohorts were defined using receiver operating characteristic curves (MS less than 13 and MS greater than 12). With the exception of tumor grade, all clinical and pathologic features, all tumor characteristics, and the numbers of TILs were similar between cohorts. The MSI phenotype is highly variable in dMMR EC, and no correlation between the immune profile and the severity of the MSI phenotype was observed.

Background concentrations of Argon-39 in shallow soil gas

While radioisotopes of noble gases are known to be indicators of underground nuclear explosions (UNE), McIntyre et al. (2017) was the first to report the presence of ³⁹Ar in shallow soil gas in association with a decades old UNE. While this finding hinted at the potential application of ³⁹Ar to be used as an indicator of a UNE, doing so would also require an understanding of the natural concentrations of ³⁹Ar present in soil gas. Without knowing the expected range and variability of naturally occurring concentrations of ³⁹Ar, it is difficult to determine what measured concentrations would be indicative of an elevated concentration. This paper presents results from 16 soil gas samples and three atmospheric air samples collected from various locations across the western United States. Shallow soil gas samples were collected into self-contained underwater breathing apparatus (SCUBA) tanks using a custom-built soil gas sampling system and then processed and analyzed for ³⁹Ar. The measured concentrations of ³⁹Ar varied from atmospheric air concentrations to about 3.5 times atmospheric air concentrations (58 mBq/m³). The results presented here represent the first measurements of natural background ³⁹Ar concentrations in shallow soil gas. This data will be necessary if ³⁹Ar is to be used as an indicator of UNE.

Three-dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules

A time-lapse study of thermomechanical fatigue damage has been undertaken using three-dimensional X-ray computer tomography. Morphologies were extracted from tomography data and integrated with data from microscopy modalities at different resolution levels. This enables contextualization of some of the fine-scale properties which underpin the large-scale damage observed via tomography. Lateral views of crack development are presented, which show networks analogous to mud-cracks. Crack fronts which develop in the most porous regions within the sintered attachment layer travel across the boundary into the copper substrate. The propagation characteristics of these cracks within the substrate are analysed. Evidence is provided of heterogeneous densification within the sintered joint under power cycling, and this is shown to play a major role in driving the initiation and propagation of the cracks. Examination of the texture (differing levels of X-ray absorption) of virtual cross-sectional images reveals the origins of the nonuniformity of densification. Finally, cracks within the sintered joint are shown to have a negligible impact on the conduction pathway of the joint due to their aspect ratio and orientation with respect to the assembly. LAY DESCRIPTION: This paper concerns the use of three-dimensional (3D) X-ray tomography, a nondestructive technique, to perform cradle-to-grave studies of sintered nanosilver die-attachments under operation. Sintered nanosilver die-attachments have been proposed as a more reliable and environmentally friendly alternative to solder alloy joints for emerging power electronics module designs. However, their degradation mechanisms are not as well understood. This same sample-study is about observing how the fine-scale structure of a sintered attachment evolves and degrades over time. Using 3D tomography affords otherwise infeasible perspectives, such as virtual cross-sections in the lateral plane of the attachment. These perspectives provide qualitative information which elucidates the degradation mechanisms. They demonstrate, for example, that the structure of the sintered attachment densifies under operation, and a consequence of this is the formation of shrinkage cracks in the most porous regions, much like mud-cracks. Other imaging techniques (metallographic etching and scanning electron microscopy) have been used in correlation with 3D renderings of these cracks to analyse their propagation and reveal their relationship both with the internal structure of the sintered attachment itself, and the structure of the substrate to which it is joined. It is shown that the cracks develop within the sintered attachment layer and eventually cross over into the substrate. A comparison of two sintered attachments with contrasting bulk porosities allows the effect of initial bond quality on crack development to be examined.

Expression of myxovirus-resistance protein A: a possible marker of muscle disease activity and autoantibody specificities in juvenile dermatomyositis

Aims

To evaluate the relationship between expression of myxovirus‐resistance protein A (MxA) protein on muscle biopsies by immunohistochemistry and disease activity in juvenile dermatomyositis (JDM) patients. Also, another aim was to investigate whether the expression of MxA is related with myositis‐specific autoantibodies (MSA) status in JDM patients.

Methods

103 patients (median aged 6.3, interquartile range 0.5–15.9) enrolled in the Juvenile Dermatomyositis Cohort and Biomarker Study (JDCBS). Muscle biopsies were stained with MxA and scored. Clinical data at initial presentation were collected and autoantibodies were analysed. Multiple linear regression analysis was performed to estimate the association between MxA expression on muscle fibres and muscle disease activity, and MSA status.

Results

Expression of MxA protein on JDM samples was identified in 61.2%. There was a significant association between MxA scores and Childhood Myositis Assessment Scale (CMAS) (P = 0.002), and Manual Muscle Testing of Eight Muscles (MMT8) (P = 0.026). CMAS and MMT8 scores were significantly lower in the group of patients with strong MxA expression. MxA scores differed according to MSA subgroups (P = 0.002). Patients with positive nuclear matrix protein 2 autoantibodies had strong MxA expression, whereas anti‐melanoma differentiation‐associated gene 5 positive patients had no or weak MxA expression.

Conclusions

This study reveals the significant association between level of MxA expression on muscle fibres and clinical measures of muscular disease activity in JDM patients and MSA status. This confirms type I interferonopathies in muscle fibres of JDM patients which could help with improving treatment outcome in JDM patients and underscoring the distinct pathophysiological pathways in different MSA status.

Observed parent-child feeding dynamics in relation to child body mass index and adiposity

BACKGROUND

Restrictive feeding is associated with child overweight; however, the majority of studies used parent-report questionnaires.

OBJECTIVES

The relationship between child adiposity measures and directly observed parent and child behaviours were tested using a novel behavioural coding system (BCS).

METHODS

Data from 109 children, participants in a twin study and their mothers, were analyzed. Parent-child dyads were video-recorded twice in the laboratory, while children ate ad libitum from a buffet lunch. Mother and child behaviours were assessed using the BCS. Height, body weight and body fat were directly measured for each child. Associations between child adiposity measures and average BCS behaviour (i.e. pooled across visits) were tested using partial correlations adjusting for child age.

RESULTS

Regarding discouragement prompts, child body mass index (BMI) z-score was significantly associated with a greater rate of total discouragements (per minute, min^-1 ), nonverbal discouragements (min^-1 ) and temporary (delay) discouragements (min^-1 ) (p < 0.05). Child percent body fat was associated with greater nonverbal discouragements (min^-1 ). Regarding encouragement prompts, child BMI z-score was significantly associated with a greater rate of total encouragements (min^-1 ), nonverbal encouragements (min^-1 ) and reward encouragements (min^-1 ). Child BMI z-score and percent body fat were both positively associated with greater maternal health encouragements (min^-1 ). Associations with encouragement to eat prompts were no longer significant when accounting for the dependence among twins (being part of the same family).

CONCLUSIONS

Heavier children received greater maternal discouragements to eat and, with qualifications, encouragements to eat. The role of nonverbal parenting cues warrants further research regarding child eating regulation and obesity.

Mutualism between co-occurring plant species in South Africa's Mediterranean climate heathland is mediated by birds

Interactions among plant species via pollinators vary from competitive to mutualistic and can influence the probability of stable coexistence of plant species. We aimed to determine the nature of the interaction via flower visitors between Leucospermum conocarpodendron and Mimetes fimbriifolius, two shrubs in the Proteaceae that share many ecological traits and coexist on the Cape Peninsula, South Africa. To assess the extent of pollinator sharing we analysed nectar properties and recorded the pollinator fauna, their behaviour and contribution to seed set. To test for competition via interspecific pollen transfer, we recorded the movement patterns of pollinators and quantified pollen loads. To determine the effect of co-flowering on visitation rates we recorded visits in stands that varied in the density of the two species. We found that the species produce similar rewards and share pollinating Cape Sugarbirds (Promerops cafer). Interspecific pollen transfer is avoided by placing pollen on different parts of the bird. Both species are visited by nectar-thieving Orange-breasted Sunbirds (Anthobaphes violacea). Insects and autonomous self-pollination contributed little to seed set. Pollinator visits increased with conspecific density in both species, and the slope of the increase was steepest in the presence of high densities of the co-occurring plant species. Nectar thief visits also increased with conspecific density in both species, but the slope declined with increasing density of the co-occurring species. Co-occurrence enhanced pollinator visits and alleviated nectar robbing in both plant species, consistent with mutualisms. Mutualism within a trophic level is unusual, but may help to explain the stable coexistence of ecologically similar species.

Oncoidal granular iron formation in the Mesoarchaean Pongola Supergroup, southern Africa: Textural and geochemical evidence for biological activity during iron deposition

We document the discovery of the first granular iron formation (GIF) of Archaean age and present textural and geochemical results that suggest these formed through microbial iron oxidation. The GIF occurs in the Nconga Formation of the ca. 3.0-2.8 Ga Pongola Supergroup in South Africa and Swaziland. It is interbedded with oxide and silicate facies micritic iron formation (MIF). There is a strong textural control on iron mineralization in the GIF not observed in the associated MIF. The GIF is marked by oncoids with chert cores surrounded by magnetite and calcite rims. These rims show laminated domal textures, similar in appearance to microstromatolites. The GIF is enriched in silica and depleted in Fe relative to the interbedded MIF. Very low Al and trace element contents in the GIF indicate that chemically precipitated chert was reworked above wave base into granules in an environment devoid of siliciclastic input. Microbially mediated iron precipitation resulted in the formation of irregular, domal rims around the chert granules. During storm surges, oncoids were transported and deposited in deeper water environments. Textural features, along with positive δ⁵⁶ Fe values in magnetite, suggest that iron precipitation occurred through incomplete oxidation of hydrothermal Fe²⁺ by iron-oxidizing bacteria. The initial Fe³⁺ -oxyhydroxide precipitates were then post-depositionally transformed to magnetite. Comparison of the Fe isotope compositions of the oncoidal GIF with those reported for the interbedded deeper water iron formation (IF) illustrates that the Fe²⁺ pathways and sources for these units were distinct. It is suggested that the deeper water IF was deposited from the evolved margin of a buoyant Fe²⁺_aq -rich hydrothermal plume distal to its source. In contrast, oncolitic magnetite rims of chert granules were sourced from ambient Fe²⁺_aq -depleted shallow ocean water beyond the plume.

Effect of Intravenous or Perivascular Injection of Synthetic Adrenocorticotropic Hormone on Stimulation Test Results in Dogs

Background

Standard protocols for adrenocorticotropic hormone (ACTH) stimulation testing (ACTHst) often involve intravenous (IV) injection of corticotropin. ACTH might be unintentionally injected into the perivascular (PV) space.

Objective

To compare stimulation test results after IV and PV injections of ACTH.

Animals

Twenty privately owned dogs were studied: 10 healthy and 10 with trilostane‐treated naturally occurring hyperadrenocorticism (HAC).

Methods

Prospective study. Each of 20 dogs underwent 2 ACTHst not <4 nor more than 14 days apart. Five healthy and 5 HAC dogs had an IV ACTHst first and PV second; 5 healthy and 5 HAC dogs had a PV ACTHst first and IV second. Blood samples for measurement of serum cortisol concentration were collected before and 1 hour after ACTH administration.

Results

No significant difference in results was demonstrated when comparing serum cortisol concentrations after IV and PV ACTH administration in all 20 dogs (median μg/dL; interval μg/dL: 8.2; 1.4–17.4 versus 7.8; 0.9–16.9; P = .23). No significant difference in results was demonstrated when comparing serum cortisol concentrations after IV and PV ACTH administration in the 10 healthy dogs (median μg/dL; interval μg/dL: 10.9; 7.3–17.4 versus 10.6; 7.1–16.9; P = .54) or in the 10 HAC dogs (median μg/dL; interval μg/dL: 6.3; 1.4–8.6 versus 5.2; 0.9–8.7; P = .061).

Conclusions and Clinical Importance

Perivascular administration of ACTH does not significantly alter stimulation test results in healthy dogs or in dogs with HAC undergoing therapy with trilostane.

Microbial Fe(III) oxide reduction potential in Chocolate Pots hot spring, Yellowstone National Park

Chocolate Pots hot springs (CP) is a unique, circumneutral pH, iron-rich, geothermal feature in Yellowstone National Park. Prior research at CP has focused on photosynthetically driven Fe(II) oxidation as a model for mineralization of microbial mats and deposition of Archean banded iron formations. However, geochemical and stable Fe isotopic data have suggested that dissimilatory microbial iron reduction (DIR) may be active within CP deposits. In this study, the potential for microbial reduction of native CP Fe(III) oxides was investigated, using a combination of cultivation dependent and independent approaches, to assess the potential involvement of DIR in Fe redox cycling and associated stable Fe isotope fractionation in the CP hot springs. Endogenous microbial communities were able to reduce native CP Fe(III) oxides, as documented by most probable number enumerations and enrichment culture studies. Enrichment cultures demonstrated sustained DIR driven by oxidation of acetate, lactate, and H2 . Inhibitor studies and molecular analyses indicate that sulfate reduction did not contribute to observed rates of DIR in the enrichment cultures through abiotic reaction pathways. Enrichment cultures produced isotopically light Fe(II) during DIR relative to the bulk solid-phase Fe(III) oxides. Pyrosequencing of 16S rRNA genes from enrichment cultures showed dominant sequences closely affiliated with Geobacter metallireducens, a mesophilic Fe(III) oxide reducer. Shotgun metagenomic analysis of enrichment cultures confirmed the presence of a dominant G. metallireducens-like population and other less dominant populations from the phylum Ignavibacteriae, which appear to be capable of DIR. Gene (protein) searches revealed the presence of heat-shock proteins that may be involved in increased thermotolerance in the organisms present in the enrichments as well as porin-cytochrome complexes previously shown to be involved in extracellular electron transport. This analysis offers the first detailed insight into how DIR may impact the Fe geochemistry and isotope composition of a Fe-rich, circumneutral pH geothermal environment.

A methacrylate-based polymeric imidazole ligand yields quantum dots with low cytotoxicity and low nonspecific binding

This paper assesses the biocompatibility for fluorescence imaging of colloidal nanocrystal quantum dots (QDs) coated with a recently-developed multiply-binding methacrylate-based polymeric imidazole ligand. The QD samples were purified prior to ligand exchange via a highly repeatable gel permeation chromatography (GPC) method. A multi-well plate based protocol was used to characterize nonspecific binding and toxicity of the QDs toward human endothelial cells. Nonspecific binding in 1% fetal bovine serum was negligible compared to anionically-stabilized QD controls, and no significant toxicity was detected on 24h exposure. The nonspecific binding results were confirmed by fluorescence microscopy. This study is the first evaluation of biocompatibility in QDs initially purified by GPC and represents a scalable approach to comparison among nanocrystal-based bioimaging scaffolds.

Effectiveness of Diabetes Prevention Program translations among African Americans

The Diabetes Prevention Program (DPP) demonstrated risk reduction for incident diabetes through weight loss among all participants, including African Americans. Several DPP translations have been conducted in less controlled settings, including primary care practices and communities; however, there is no detailed compilation of how effective these translations have been for African Americans. This systematic literature review evaluated DPP translations from 2003 to 2012. Eligible records were retrieved using a search strategy of relevant databases and gray literature. Retrieved records (n=1,272) were screened using a priori criteria, which resulted in 21 full-text studies for review. Seventeen studies were included in the full-text qualitative synthesis. Seven studies had 100% African American samples and 10 studies had mixed samples with African American subgroups. African American participants' average weight loss was roughly half of that achieved in the DPP intervention. However, with few higher-quality studies, small sample sizes and differences in intervention designs and implementation, comparisons across interventions were difficult. The suboptimal effectiveness of DPP translations among African American adults, particularly women, signals the need for enhancements to existing evidence-based interventions and more high-quality research that includes other at-risk African American subgroups such as men and younger adults of lower socioeconomic status.

Physical limitations in meal preparation and consumption are associated with lower musculoskeletal nutrient (calcium, vitamin D, magnesium, and phosphorus) intakes in homebound older adults

OBJECTIVES

Although homebound older adults are at increased risk for poor nutritional health and adverse nutrition-related outcomes, little attention has focused on the tasks involved in meal preparation and consumption and the influence of those tasks on dietary intake.

METHODS

We examined the self-reported dietary intake from 3, 24-h dietary recalls and physical limitations in meal preparation and consumption (LMPC) activities from a randomly recruited sample of 345 homebound older men and women. Ordered logistic regression was used to examine the correlation of demographic characteristics and 6 activities with relative intakes of key musculoskeletal nutrients (calcium, vitamin D, magnesium, and phosphorus).

RESULTS

At least 70% reported not meeting ⅔ recommended intakes for calcium and vitamin D; 12.5% failed to achieve ⅔ recommended intakes in at least three of the four nutrients. More than 12% of the sample reported it was very difficult or they were unable to perform at least 3 LMPC tasks. Regression results indicated that reporting the greatest LMPC increased the odds for lower intake of musculoskeletal nutrients.

CONCLUSION

Independent of sociodemographic characteristics, self-reported difficulty in meal preparation and consumption was associated with lower dietary intakes of musculoskeletal nutrients. These results suggest the need to assess difficulty in meal preparation and consumption for the growing population of homebound older adults who participate in supplemental nutrition programs. This brief, 6-item measure may help identify older adults at risk of poor nutritional health and declining function.

Iron isotope fractionation during microbial dissimilatory iron oxide reduction in simulated Archaean seawater

The largest Fe isotope excursion yet measured in marine sedimentary rocks occurs in shales, carbonates, and banded iron formations of Neoarchaean and Paleoproterozoic age. The results of field and laboratory studies suggest a potential role for microbial dissimilatory iron reduction (DIR) in producing this excursion. However, most experimental studies of Fe isotope fractionation during DIR have been conducted in simple geochemical systems, using pure Fe(III) oxide substrates that are not direct analogues to phases likely to have been present in Precambrian marine environments. In this study, Fe isotope fractionation was investigated during microbial reduction of an amorphous Fe(III) oxide-silica coprecipitate in anoxic, high-silica, low-sulphate artificial Archaean seawater at 30 °C to determine if such conditions alter the extent of reduction or isotopic fractionations relative to those observed in simple systems. The Fe(III)-Si coprecipitate was highly reducible (c. 80% reduction) in the presence of excess acetate. The coprecipitate did not undergo phase conversion (e.g. to green rust, magnetite or siderite) during reduction. Iron isotope fractionations suggest that rapid and near-complete isotope exchange took place among all Fe(II) and Fe(III) components, in contrast to previous work on goethite and hematite, where exchange was limited to the outer few atom layers of the substrate. Large quantities of low-δ(56)Fe Fe(II) (aqueous and solid phase) were produced during reduction of the Fe(III)-Si coprecipitate. These findings shed new light on DIR as a mechanism for producing Fe isotope variations observed in Neoarchaean and Paleoproterozoic marine sedimentary rocks.

Microbial production of isotopically light iron(II) in a modern chemically precipitated sediment and implications for isotopic variations in ancient rocks

The inventories and Fe isotope composition of aqueous Fe(II) and solid-phase Fe compounds were quantified in neutral-pH, chemically precipitated sediments downstream of the Iron Mountain acid mine drainage site in northern California, USA. The sediments contain high concentrations of amorphous Fe(III) oxyhydroxides [Fe(III)(am)] that allow dissimilatory iron reduction (DIR) to predominate over Fe-S interactions in Fe redox transformation, as indicated by the very low abundance of Cr(II)-extractable reduced inorganic sulfur compared with dilute HCl-extractable Fe. delta(56)Fe values for bulk HCl- and HF-extractable Fe were approximately 0. These near-zero bulk delta(56)Fe values, together with the very low abundance of dissolved Fe in the overlying water column, suggest that the pyrite Fe source had near-zero delta(56)Fe values, and that complete oxidation of Fe(II) took place prior to deposition of the Fe(III) oxide-rich sediment. Sediment core analyses and incubation experiments demonstrated the production of millimolar quantities of isotopically light (delta(56)Fe approximately -1.5 to -0.5 per thousand) aqueous Fe(II) coupled to partial reduction of Fe(III)(am) by DIR. Trends in the Fe isotope composition of solid-associated Fe(II) and residual Fe(III)(am) are consistent with experiments with synthetic Fe(III) oxides, and collectively suggest an equilibrium Fe isotope fractionation between aqueous Fe(II) and Fe(III)(am) of approximately -2 per thousand. These Fe(III) oxide-rich sediments provide a model for early diagenetic processes that are likely to have taken place in Archean and Paleoproterozoic marine sediments that served as precursors for banded iron formations. Our results suggest pathways whereby DIR could have led to the formation of large quantities of low-delta(56)Fe minerals during BIF genesis.

In vivo endothelial cell infection by Anaplasma marginale

Anaplasma marginale has recently been shown to infect endothelial cells in vitro, but it remains unknown as to whether endothelial infection also occurs in vivo. In this report, we demonstrate through dual fluorescence microscopy that A marginale, detected by the monoclonal antibody ANAF16C1, co-localizes with the endothelial cell marker, von Willebrand factor, in tissue sections from an experimentally inoculated calf. The results indicate that A marginale infection includes endothelial cells and has implications for both pathogenesis and immune mechanisms.

Analysis of the BTNL2 truncating splice site mutation in tuberculosis, leprosy and Crohn's disease

The region on chromosome 6 encoding the major histocompatibility complex (MHC) is associated with a number of autoimmune and infectious diseases. Primary susceptibility to many of these has been localized to a region containing the human leukocyte antigen (HLA)-DR and -DQ genes. A recent study of sarcoidosis has provided evidence of an independent effect, associated with a truncating single nucleotide polymorphism (SNP) of a nearby gene, BTNL2. This gene may encode an immune receptor involved in costimulation. Sarcoidosis, tuberculoid leprosy, tuberculosis (TB) and Crohn's disease all have similar immunological features, including a Th1 response with granuloma formation. In addition mycobacteria have been identified or suggested to be causative pathogens in such conditions. We genotyped the truncating BTNL2 SNP in 92 TB and 72 leprosy families from Brazil and carried out family-based association studies. We could not find evidence of overtransmission of the truncating allele in TB. There was an association with susceptibility to leprosy (P=0.04), however, this is most likely due to linkage disequilibrium with HLA-DR. We also genotyped 476 UK Caucasian cases of Crohn's disease with 760 geographically matched controls and found no evidence of a disease association. We conclude that the truncating BTNL2 SNP is not important in this group of Th1 dominated granulomatous diseases.

Identification of novel VHL targets that are associated with the development of renal cell carcinoma

von Hippel-Lindau (VHL) disease is a dominantly inherited family cancer syndrome characterized by the development of retinal and central nervous system haemangioblastomas, renal cell carcinoma (RCC) and phaeochromocytoma. Specific germline VHL mutations may predispose to haemangioblastomas, RCC and phaeochromocytoma to a varying extent. Although dysregulation of the hypoxia-inducible transcription factor-2 and JunB have been linked to the development of RCC and phaeochromocytoma, respectively, the precise basis for genotype-phenotype correlations in VHL disease have not been defined. To gain insights into the pathogenesis of RCC in VHL disease we compared gene expression microarray profiles in a RCC cell line expressing a Type 1 or Type 2B mutant pVHL (RCC-associated) to those of a Type 2A or 2C mutant (not associated with RCC). We identified 19 differentially expressed novel VHL target genes linked to RCC development. Eight targets were studied in detail by quantitative real-time polymerase chain reaction (three downregulated and five upregulated by wild-type VHL) and for six genes the effect of VHL inactivation was mimicked by hypoxia (but hypoxic-induction of smooth muscle alpha-actin 2 was specific for a RCC cell line). The potential role of four RCC-associated VHL target genes was assessed in vitro. NB thymosin beta (TMSNB) and proteinase-activated receptor 2 (PAR2) (both downregulated by wt pVHL) increased cell growth and motility in a RCC cell line, but aldehyde dehydrogenase (ALDH)1 and ALDH7 had no effect. These findings implicate TMSNB and PAR2 candidate oncogenes in the pathogenesis of VHL-associated RCC.

Linking bacteriophage infection to quorum sensing signalling and bioluminescent bioreporter monitoring for direct detection of bacterial agents

AIM

To incorporate into the lambda phage genome, a luxI-based acyl-homoserine lactone (AHL) synthase genetic construct and exploit the autoamplified power of quorum sensing to translate a phage infection event into a chemical signature detectable by a lux-based bioluminescent bioreporter, with focus towards facile detection of microbial pathogens.

METHODS AND RESULTS

The luxI gene from Vibrio fischeri was inserted into the lambda phage genome to construct a model phage-based biosensor system for the general detection of Escherichia coli. The AHL signalling molecules synthesized upon phage infection are detected by an AHL-specific bioluminescent bioreporter based on the luxCDABE gene cassette of V. fischeri. The assay generates target-specific visible light signals with no requisite addition of extraneous substrate. This binary reporter system was able to autonomously respond to lambda phage infection events at target E. coli concentrations ranging from 1 x 10(8) to 1 CFU ml(-1) within 1.5-10.3 h, respectively, in pure culture. When assayed against artificially contaminated lettuce leaf washings, detection within an E. coli inoculum range from 1 x 10(8) to 130 CFU ml(-1) was achieved within 2.6-22.4 h, respectively.

CONCLUSIONS

The initial feasibility of binary phage-based reporter assays indicates that quorum sensing can be used to translate a phage infection event into an autoamplified chemical signature.

SIGNIFICANCE AND IMPACT OF STUDY

With further modification, binary phage-based reporter assays may be capable of rapidly and cost effectively detecting pathogenic agents at very low population densities.

Effect of nutrient ingestion on total-body and splanchnic cortisol production in humans

The splanchnic bed produces cortisol at rates approximating extraadrenal tissues by converting cortisone to cortisol via the 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 pathway. It is not known whether splanchnic cortisol production is regulated by nutrient ingestion and/or by the accompanying changes in hormone secretion. To address this question, 18 healthy humans were randomized to ingest either a mixed meal or to receive an intravenous saline infusion while total-body, splanchnic, and D3 cortisol production (an index of 11beta-HSD type 1 activity) were measured using the combined hepatic catheterization and D4 cortisol infusion methods. Fasting glucose and insulin concentrations did not differ on the meal and saline study days. Glucose and insulin concentrations increased after meal ingestion, peaking at 11.0 +/- 1.0 mmol/l and 451 +/- 64 pmol/l, respectively, at 45 min, then fell to baseline thereafter. In contrast, glucose and insulin concentrations slowly fell to 5.1 +/- 0.1 mmol/l and 27 +/- 6 pmol/l during the 6 h of observation on the saline study day. Fasting cortisol concentration did not differ on the meal and saline study days. Cortisol increased (P < 0.05) to a peak of 353 +/- 55 nmol/l after meal ingestion but did not change after saline infusion. The increase in cortisol after meal ingestion was associated with an increase in both total body cortisol (from 748 +/- 63 to 1,620 +/- 235 nmol/min; P < 0.01) and total body D3 cortisol (from 99 +/- 11 to 143 +/- 11 nmol/min; P < 0.01) production, whereas there was no change in either on the saline study day. The increase in total-body cortisol and D3 cortisol production after meal ingestion originated in extrasplanchnic tissues since splanchnic cortisol production (mean 0-360 min: 254 +/- 83 vs. 262 +/- 36 nmol/min) and splanchnic D3 cortisol production (mean 0-360 min: 72 +/- 22 vs. 77 +/- 14 nmol/min) did not differ on the meal and saline study days. We conclude that ingestion of a mixed meal does not alter either splanchnic cortisol production or the conversion of D4 cortisol to D3 cortisol or, therefore by implication, flux via the splanchnic 11beta-HSD type 1 pathway.

Characterization of surface interleukin-2 receptor expression on gated populations of peripheral blood mononuclear cells from manatees, Trichechus manatus latirostris

An in vitro system to determine surface interleukin-2 receptor (IL-2R) expression on mitogen-stimulated peripheral blood mononuclear cells (PBMC) from free-ranging manatees, Trichechus manatus latirostris was developed. Human recombinant IL-2, conjugated with a fluorescein dye was used in conjunction with flow cytometric analysis to determine changes in surface expression of IL-2R at sequential times over a 48-h period of in vitro stimulation. Surface expression of IL-2R was detected on manatee PBMC, which also cross-reacted with an anti-feline pan T-cell marker. An expression index (EI) was calculated by comparing mitogen-activated and non-activated PBMC. Based on side- and forward-scatter properties, flow cytometric analysis showed an increase in the number of larger, more granular "lymphoblasts" following concanavalin A (Con A) stimulation. The appearance of lymphoblasts was correlated with an increase in their surface expression of IL-2 receptors. Surface IL-2R expression, in Con A-stimulated PBMC, was detected at 16 h, peaked at 24-36 h, and began to decrease by 48 h. Characterization of the IL-2R expression should provide additional information on the health status of manatees, and the effect of their sub lethal exposure to brevetoxin.

Presence of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) in southern Kettle Moraine State Forest, Wisconsin, and characterization of strain W97F51

Lyme disease, caused by Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt & Brenner; babesiosis, caused by Babesia microti Franca; and human granulocytic ehrlichiosis, caused by Anaplasma phagocytophilum Bakken & Dumler have been reported in Wisconsin, mainly in the endemic areas of the northwestern part of the state. People exposed to blacklegged ticks, Ixodes scapularis Say, from this region can potentially contract one or all of these diseases concurrently. Within the past several years, there have been cases of Lyme disease reported from southeastern Wisconsin, an area that contains deer, mice, and similar vegetation found at regions with high endemicity. However, past white-tailed deer surveys suggested no existence of I. scapularis in southeastern Wisconsin. However, in 1996, we identified questing adult I. scapularis in the southernmost part of the Southern Kettle Moraine State Forest, Walworth County. To determine whether an established population of I. scapularis exists in this region, we performed a detailed survey of the abundance of host-seeking I. scapularis adults and the presence and abundance of subadults feeding on white-footed mice, Peromyscus leucopus Rafinesque. We also tested for possible infections of B. burgdorferi, Ba. microti, and A. phagocytophilum in ticks and B. burgdorferi harbored by mice. In 1997 and 1998, a total of 249 P. leucopus mice and 118 questing adult I. scapularis ticks, in addition to 157 larvae and seven nymphs feeding on mice, were collected and their locations were recorded from the Nordic trails of the Southern Kettle Moraine State Forest. Only one P. leucopus and its attached engorged I. scapularis nymph were infected with B. burgdorferi, whereas none of the engorged larvae attached to mice were infected. However, 4.2% of questing adult I. scapularis were infected with B. burgdorferi. The abundance of questing adult I. scapularis was 1.6 ticks per hour. The prevalence of subadult ticks on mice was 27%, with a mean intensity on infested mice of 2.0. I. scapularis adults were not infected with either Ba. microti or A. phagocytophilum. A unique strain of B. burgdorferi s.l. (W97F51) was discovered, showing 33 nucleotide substitutions and one codon insertion in a 567-bp fragment of the OspB gene, compared with Borrelia bissettii (strain Ca389). The sequences of ospA, ospB, ospC,fla, and rrs genes and the rrf-rrl intergenic spacer region were compared between W97F51 and other B. burgdorferi s.l. species. Although W97F51 was most genetically related to B. bissettii, the genetic identity of W97F51 was less than that of B. bissettii conspecifics. This study documents the existence of an established population of I. scapularis and the presence of B. burgdorferi with a novel strain in southeastern Wisconsin.

Ventral otic cell lines as developmental models of auditory epithelial and neural precursors

Conditionally immortal cell lines were established from the ventral otocyst of the Immortomouse at embryonic day 10.5 and selected to represent precursors of auditory sensory neural and epithelial cells. Selection was based upon dissection, tissue-specific markers, and expression of the transcription factor GATA3. Two cell lines expressed GATA3 but possessed intrinsically different genetic programs under differentiating conditions. US/VOT-E36 represented epithelial progenitors with potential to differentiate into sensory and nonsensory epithelial cells. US/VOT-N33 represented migrating neuroblasts. Under differentiating conditions in vitro the cell lines expressed very different gene expression profiles. Expression of several cell- and tissue-specific markers, including the transcription factors Pax2, GATA3, and NeuroD, differed between the cell lines in a pattern consistent with that observed between their counterparts in vivo. We suggest that these and other conditionally immortal cell lines can be used to study transient events in development against different backgrounds of cell competence.

Glaucoma studies in the eyeless worm: stress responsiveness and temporal expression of the Caenorhabditis elegans myocilin-like gene, cof-2

Prolonged exposure to stress and the resulting over-stimulation of the HPA system are often detrimental to the homeostasis of an organism. In fact, chronic stress is believed to affect the pathology of several disease states including coronary heart disease and hypertension, diabetes and obesity. In humans, mutations in the GLC1A gene have been associated with primary open angle glaucoma. Previous studies on this gene have suggested that its expression is also affected by the same factors that mediate the stress response. With the ultimate goal of using the nematode, Caenorhabditis elegans, as an invertebrate model for glaucoma, we have measured the stress responsiveness of the cof-2 gene, one of two C. elegans proteins with significant homology to the myocilin olfactomedin domain. We show that both cof-2 mRNA and protein expression are developmentally regulated and that both are affected by heat shock stress.

The DNA sequence and analysis of human chromosome 6

Chromosome 6 is a metacentric chromosome that constitutes about 6% of the human genome. The finished sequence comprises 166,880,988 base pairs, representing the largest chromosome sequenced so far. The entire sequence has been subjected to high-quality manual annotation, resulting in the evidence-supported identification of 1,557 genes and 633 pseudogenes. Here we report that at least 96% of the protein-coding genes have been identified, as assessed by multi-species comparative sequence analysis, and provide evidence for the presence of further, otherwise unsupported exons/genes. Among these are genes directly implicated in cancer, schizophrenia, autoimmunity and many other diseases. Chromosome 6 harbours the largest transfer RNA gene cluster in the genome; we show that this cluster co-localizes with a region of high transcriptional activity. Within the essential immune loci of the major histocompatibility complex, we find HLA-B to be the most polymorphic gene on chromosome 6 and in the human genome.

An analysis of music therapy student practicum behaviors and their relationship to clinical effectiveness: an exploratory investigation

The purpose of the present study was to investigate specific clinical behaviors exhibited by music therapy students in their 1st through 4th semesters of practicum. A secondary purpose of the study was to determine if a relationship exists between therapy students' behaviors and their assessed clinical success. Participants were instructed to submit 20-minutes of videotape from one practicum session, chosen at random from the current practicum semester. Two trained observers then viewed the videotapes and simultaneously recorded the occurrence and duration of practicum student behaviors using SCRIBE, a data collection computer program. The SCRIBE program was configured to include 5 broad categories of therapist behaviors: musical behaviors (singing, playing, listening), physical behaviors (such as hand-over-hand assistance, cueing, or clapping), verbal behaviors (therapy-related verbal interactions or other), a combination of two of the above, and other nonspecified behaviors. The percentage of time practicum students exhibited behaviors within in each category was calculated for all session segments. These same videotapes were also evaluated by 2 professional board certified music therapists who were unfamiliar with the practicum students. Students were assigned an overall rating for clinical effectiveness. Evaluators were also asked to provide comments related to their ratings. A descriptive analysis of clinical behaviors indicate that students spend nearly 40% of their practicum time engaged in musical behaviors and over 50% of their time engaged in verbal behaviors. No significant differences were found in the behaviors exhibited by students in the various practicum levels; however, behavioral differences were found for individual student therapists. Additionally, no relationship was found between students' behaviors and their clinical effectiveness. An analysis of comments by the evaluators indicates that the quantity of musical behaviors does not affect clinical effectiveness as much as the quality of the musical behaviors. Evaluator comments also indicate that students identified as personable or as having rapport with their clients were also more effective in the practicum setting.

The face lift: technical considerations

The approach to the aging face patient must maintain the goal of a consistent, lasting, and natural result. The deep plane rhytidectomy technique satisfies these criteria and allows the surgeon to address the key issues of neck, jawline, and midface aging in a reliable and predictable fashion. This approach offers the advantages of (1) greater anatomic appeal for the operating surgeon with a cleaner plane of dissection, (2) stronger flaps for soft tissue redraping, (3) decreased complications with less risk of undue skin tension, (4) improved aging midface and melolabial fold correction, and (5) the ability to better revise previous face lift attempts and achieve a more consistent facial symmetry and balance. Our technique has evolved from previous superficial musculo-aponeurotic system (SMAS) flap rhytidectomy and is described in a step-by-step fashion in this article. This approach appears to achieve excellent results while minimizing complications and may be more appealing than some other, less proven, alternatives to the aging face patient.

The DNA sequence and comparative analysis of human chromosome 20

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

Heat does not come in different colours: entropy-enthalpy compensation, free energy windows, quantum confinement, pressure perturbation calorimetry, solvation and the multiple causes of heat capacity effects in biomolecular interactions

Modern techniques in microcalorimetry allow us to measure directly the heat changes and associated thermodynamics for biomolecular processes in aqueous solution at reasonable concentrations. All these processes involve changes in solvation/hydration, and it is natural to assume that the heats for these processes should reflect, in some way, such changes in solvation. However, the interpretation of data is still somewhat ambiguous, since different non-covalent interactions may have similar thermodynamic signatures, and analysis is frustrated by large entropy-enthalpy compensation effects. Changes in heat capacity (Delta C(p)) have been related to changes in hydrophobic hydration and non-polar accessible surface areas, but more recent empirical and theoretical work has shown how this need not always be the case. Entropy-enthalpy compensation is a natural consequence of finite Delta C(p) values and, more generally, can arise as a result of quantum confinement effects, multiple weak interactions, and limited free energy windows, giving rise to thermodynamic homeostasis that may be of evolutionary and functional advantage. The new technique of pressure perturbation calorimetry (PPC) has enormous potential here as a means of probing solvation-related volumetric changes in biomolecules at modest pressures, as illustrated with preliminary data for a simple protein-inhibitor complex.

Using flexible loop mimetics to extend phi-value analysis to secondary structure interactions

Chemical synthesis allows the incorporation of nonnatural amino acids into proteins that may provide previously untried probes of their folding pathway and thermodynamic stability. We have used a flexible thioether linker as a loop mimetic in the human yes kinase-associated protein (YAP 65) WW domain, a three-stranded, 44-residue, beta-sheet protein. This linkage avoids problems of incorporating sequences that constrain loops to the extent that they significantly change the nature of the denatured state with concomitant effects on the folding kinetics. An NMR solution structure shows that the thioether linker had little effect on the global fold of the domain, although the loop is apparently more dynamic. The thioether variants are destabilized by up to 1.4 kcal/mol (1 cal = 4.18 J). Preliminary Phi-value analysis showed that the first loop is highly structured in the folding transition state, and the second loop is essentially unstructured. These data are consistent with results from simulated unfolding and detailed protein-engineering studies of structurally homologous WW domains. Previously, Phi-value analysis was limited to studying side-chain interactions. The linkers used here extend the protein engineering method directly to secondary-structure interactions.

Ultrafast folding of WW domains without structured aromatic clusters in the denatured state

Ultrafast-folding proteins are important for combining experiment and simulation to give complete descriptions of folding pathways. The WW domain family comprises small proteins with a three-stranded antiparallel beta-sheet topology. Previous studies on the 57-residue YAP 65 WW domain indicate the presence of residual structure in the chemically denatured state. Here we analyze three minimal core WW domains of 38-44 residues. There was little spectroscopic or thermodynamic evidence for residual structure in either their chemically or thermally denatured states. Folding and unfolding kinetics, studied by using rapid temperature-jump and continuous-flow techniques, show that each domain folds and unfolds very rapidly in a two-state transition through a highly compact transition state. Folding half-times were as short as 17 micros at 25 degrees C, within an order of magnitude of the predicted maximal rate of loop formation. The small size and topological simplicity of these domains, in conjunction with their very rapid two-state folding, may allow us to reduce the difference in time scale between experiment and theoretical simulation.

Tissue dynamics of CD8 lymphocytes that suppress viral replication in cats infected neonatally with feline immunodeficiency virus

The purpose of this study was to determine the tissue distribution and antiviral activity of the CD8 lymphocytes that suppress the replication of feline immunodeficiency virus (FIV). Cell-associated FIV load, CD8alpha(+)beta(low) cells, and CD8 cell-mediated suppression of FIV were measured serially in the blood, thymus, and peripheral lymph nodes after neonatal inoculation. Between 6 and 10 weeks, relative numbers of CD8alpha(+)beta(low) cells increased, whereas CD8alpha(+)beta(high) cells declined in the thymus and blood of infected cats. By 12-16 weeks, the lymph nodes were enlarged because of an absolute expansion of all CD8beta subpopulations. The strength of CD8 cell-mediated FIV suppression in vitro, but not CD8alpha(+)beta(low) cell content, was correlated inversely with virus load in the thymus and blood. Thus, after neonatal FIV inoculation, CD8alpha(+)beta(low) cells first occupy the thymus and blood, where strong CD8 cell-mediated antiviral activity is linked to reduced virus load in multiple lymphoid tissues.

Infant sleep: resident recommendations and socioeconomic status differences in patient practices

BACKGROUND

Although much research has focused on parental report of infant sleep position since the 1992 American Academy of Pediatrics (AAP) recommendation for non-prone placement, few studies have examined physician recommendations regarding infant sleep. This study examined differences between resident recommendations for infant sleep position and cosleeping (bed sharing) and parental report of practice. We also assessed socioeconomic differences in parent practice, awareness, and acceptability of AAP guidelines.

METHODS

We conducted a telephone survey of parents of 2-, 4-, 8-, and 12-month-old infants from two family practice centers. All 27 residents at both centers completed a paper and pencil survey.

RESULTS

Resident recommendations and parental practices differed significantly for both sleep positioning and cosleeping. Parents of 165 infants participated, revealing that higher socioeconomic families were more aware of compliant with, and more accepting of AAP recommendations for supine positioning.

CONCLUSIONS

Parents consistently report that their physician or nurse is the primary source of information for infant sleep. Results of this study, however, indicate significant differences between physician recommendation and parental practice and acceptability of AAP guidelines. Physicians need to continue to discuss this information past the newborn period.

Thymic lesions in cats infected with a pathogenic molecular clone or an ORF-A/2-deficient molecular clone of feline immunodeficiency virus

Previous studies using feline immunodeficiency virus (FIV) molecular clones lacking the putative transactivator gene (ORF-A/2) failed to address the issue of thymus pathogenesis or investigate the levels of viral replication in separate lymphoid compartments (Y. Inoshima, et al., J. Virol. 70:8518-8526, 1996; E. E. Sparger, et al., Virology 205:546-553, 1994). Using a highly pathogenic molecular clone of FIV, JSY3, and an ORF-A/2-deficient mutant, JSY3DeltaORF-A/2, we compared viral replication and the extent of thymic dysfunction as measured by the formation of lymphoid follicles and alteration of the thymocyte subsets. Viral replication was reduced in JSY3DeltaORF-A/2-infected cats as measured by lymphocyte coculture, immunohistochemistry, and quantitative PCR. Cell-associated viral load measured by lymphocyte coculture varied in a tissue-dependent manner with replication highest in lymphocytes isolated from the thymus, lower in those from the peripheral blood, and lowest in those from lymph node. Thymic proviral load and the number of viral p24 Gag-positive cells within the thymus detected by immunohistochemistry were also reduced. In addition, the onset of a reduced peripheral blood CD4/CD8 ratio was delayed in JSY3DeltaORF-A/2-infected cats. The formation and extent of thymic lymphoid follicular hyperplasia were similar in JSY3 and JSY3DeltaORF-A/2-infected cats as measured by anticytokeratin immunohistochemistry and flow cytometry for percent pan T-negative, immunoglobulin G-positive cells within the thymus. In contrast, comparison of thymocyte subpopulations demonstrated a reduced expansion of single-positive CD4(-) CD8(+) thymocytes in JSY3DeltaORF-A/2-infected cats. Level of viral replication, therefore, may not correlate with the formation of thymic lymphoid follicles but may correlate with the expansion of the single-positive CD4(-) CD8(+) thymocyte subpopulation.

Organ donation: a statewide survey of trauma surgeons

PURPOSE

Organ procurement organizations (OPOs) operate under the premise that Americans would donate organs and/or tissue if placed in appropriate circumstances. This study evaluated opinions of Pennsylvania trauma surgeons regarding OPOs and organ donation.

METHODS

Ninety-six Pennsylvania trauma surgeons were surveyed and descriptive results calculated.

RESULTS

Ninety percent were familiar with criteria for organ donation, and about 76% would invoke their institution's brain death policy even if families did not desire to donate organs. A small portion did not routinely pronounce patients brain dead that met criteria. One fourth indicated trauma surgeons should have no role in requesting organs. A majority believed trauma surgeons should have a role in organ donation requests, either alone or with an OPO representative, and most indicated that they could influence a family's decision.

CONCLUSION

Requestor attitude is important, and our results show an overall positive attitude toward donation and a solid level of knowledge regarding donor eligibility. Hospital development programs to improve donation consent should emphasize decoupling of brain death discussion and donation request, work to improve staff attitudes about approaching patients, and address donor eligibility criteria.

Measuring cosmetic facial plastic surgery outcomes: a pilot study

OBJECTIVE

To test 4 previously published outcomes instruments (the Facelift Outcomes Evaluation, the Rhinoplasty Outcomes Evaluation, the Blepharoplasty Outcomes Evaluation, and the Skin Rejuvenation Outcomes Evaluation) in terms of their reliability and validity in assessing patient-related outcomes of surgical intervention.

DESIGN

A prospective pilot study of 78 patients in 3 similar private cosmetic surgery centers undergoing a total of 100 face-lift, rhinoplasty, blepharoplasty, and skin rejuvenation procedures. Patients were evaluated at 2 preoperative and 1 postoperative time points and the instruments were analyzed with regard to their test-retest reliability, internal consistency, and responsiveness to change.

RESULTS

All 4 outcomes instruments had excellent reliability, consistency, and validity scores. Test-retest reliability was 0.74 to 0.83 (Pearson correlation coefficients), internal consistency scores were.83 to.88 (Cronbach alpha), and responsiveness to change was statistically significant for each instrument tested (P< or =.001). In addition, patients experienced significant quality of life improvement, with overall satisfaction increasing on average from 37% to more than 84% after these procedures.

CONCLUSIONS

These 4 instruments are reliable and valid and can be used to accurately assess patient-related satisfaction in studies of face-lift, rhinoplasty, blepharoplasty, and skin resurfacing outcomes. These brief questionnaires provide the cosmetic surgeon with quantitative tools to evaluate otherwise subjective and purely qualitative outcomes and are recommended for use in future prospective studies.

Type 2 diabetes impairs splanchnic uptake of glucose but does not alter intestinal glucose absorption during enteral glucose feeding: additional evidence for a defect in hepatic glucokinase activity

We have previously reported that splanchnic glucose uptake, hepatic glycogen synthesis, and hepatic glucokinase activity are decreased in people with type 2 diabetes during intravenous glucose infusion. To determine whether these defects are also present during more physiological enteral glucose administration, we studied 11 diabetic and 14 nondiabetic volunteers using a combined organ catheterization-tracer infusion technique. Glucose was infused into the duodenum at a rate of 22 micromol. kg(-1). min(-1) while supplemental glucose was given intravenously to clamp glucose at approximately 10 mmol/l in both groups. Endogenous hormone secretion was inhibited with somatostatin, and insulin was infused to maintain plasma concentrations at approximately 300 pmol/l (i.e., twofold higher than our previous experiments). Total body glucose disappearance, splanchnic, and leg glucose extractions were markedly lower (P < 0.01) in the diabetic subjects than in the nondiabetic subjects. UDP-glucose flux, a measure of glycogen synthesis, was approximately 35% lower (P < 0.02) in the diabetic subjects than in the nondiabetic subjects. This was entirely accounted for by a decrease (P < 0.01) in the contribution of extracellular glucose because the contribution of the indirect pathway to hepatic glycogen synthesis was similar between groups. Neither endogenous and splanchnic glucose productions nor rates of appearance of the intraduodenally infused glucose in the portal vein differed between groups. In summary, both muscle and splanchnic glucose uptake are impaired in type 2 diabetes during enteral glucose administration. The defect in splanchnic glucose uptake appears to be due to decreased uptake of extracellular glucose, implying decreased glucokinase activity. Thus, abnormal hepatic and muscle (but not gut) glucose metabolism are likely to contribute to postprandial hyperglycemia in people with type 2 diabetes.

Unique susceptibility of the fetal thymus to feline immunodeficiency virus infection: an animal model for HIV infection in utero

PROBLEM

Human infants infected in utero with HIV develop thymus insufficiency and progress to AIDS sooner than infants infected peripartum. However, direct analysis of the thymus is difficult due to limited tissue access and variable timing of vertical transmission.

METHOD OF STUDY

Fetal and neonatal cats were inoculated with feline immunodeficiency virus (FIV) at an equivalent infectious dose. The thymus, blood, and lymph nodes were harvested and compared at 23 and 46 days post-inoculation (p.i.) and also compared to sham-inoculated, age-matched controls. Lymphocyte phenotypes were analyzed by flow cytometry and virus burden was quantified in histologic sections and by virus isolation from plasma.

RESULTS

Fetal cats inoculated with FIV had acute thymus atrophy at birth, which coincided with peak viremia. At 46 days p.i., thymus size and cell composition rebounded and supported increased productive infection. In contrast, neonatal cats inoculated with FIV developed chronic thymus atrophy and degeneration, which was associated with decreasing productive infection and low-level viremia.

CONCLUSIONS

The fetal thymus is uniquely vulnerable to acute, transient depletion and high-level productive infection. The neonatal thymus is less vulnerable to acute changes, and responds through progressive atrophy and declining productive infection. Reduced immune competence, as reflected by the failure to control virus replication, may contribute to the accelerated progression of FIV and HIV infections in utero.

Pseudohyperkalemia secondary to postsplenectomy thrombocytosis

Hyperkalemia is a regularly encountered electrolyte abnormality. Less commonly recognized is pseudohyperkalemia. In vitro clotting results in the release of potassium from the formed elements of blood; this falsely elevates the serum potassium concentration. Usually attributed to thrombocytosis, leukocytosis, or hemolysis it is rarely reported in the postsplenectomy trauma patient. A 49-year-old man underwent splenectomy for a grade IV splenic injury. He developed an elevated serum potassium on postoperative day 16. His renal function remained normal, and an active search for causes of hyperkalemia failed to delineate a source for his elevated potassium. Pseudohyperkalemia was proposed as an etiology and confirmed by analyzing simultaneous serum (5.9 mEq/L) and plasma potassium levels (3.9 mEq/L). The serum potassium showed a concomitant rise with the evolution of the patient's postsplenectomy thrombocytosis. This is a case report of our patient and a literature review of this rarely reported and underestimated cause of a potentially serious electrolyte abnormality. We found through our patient that pseudohyperkalemia does occur in the postsplenectomy population and that this should be included in the differential diagnosis of any patient with an elevated serum potassium level and thrombocytosis.