Pediatric human nose organoids demonstrate greater susceptibility, epithelial responses, and cytotoxicity than adults during RSV infection

Respiratory syncytial virus (RSV) is a common cause of respiratory infections, causing significant morbidity and mortality, especially in young children. Why RSV infection in children is more severe as compared to healthy adults is not fully understood. In the present study, we infect both pediatric and adult human nose organoid-air liquid interface (HNO-ALIs) cell lines with two contemporary RSV isolates and demonstrate how they differ in virus replication, induction of the epithelial cytokine response, cell injury, and remodeling. Pediatric HNO-ALIs were more susceptible to early RSV replication, elicited a greater overall cytokine response, demonstrated enhanced mucous production, and manifested greater cellular damage compared to their adult counterparts. Adult HNO-ALIs displayed enhanced mucus production and robust cytokine response that was well controlled by superior regulatory cytokine response and possibly resulted in lower cellular damage than in pediatric lines. Taken together, our data suggest substantial differences in how pediatric and adult upper respiratory tract epithelium responds to RSV infection. These differences in epithelial cellular response can lead to poor mucociliary clearance and predispose infants to a worse respiratory outcome of RSV infection.

The human nose organoid respiratory virus model: an ex-vivo human challenge model to study RSV and SARS-CoV-2 pathogenesis and evaluate therapeutics

There is an unmet need for pre-clinical models to understand the pathogenesis of human respiratory viruses; and predict responsiveness to immunotherapies. Airway organoids can serve as an ex-vivo human airway model to study respiratory viral pathogenesis; however, they rely on invasive techniques to obtain patient samples. Here, we report a non-invasive technique to generate human nose organoids (HNOs) as an alternate to biopsy derived organoids. We made air liquid interface (ALI) cultures from HNOs and assessed infection with two major human respiratory viruses, respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Infected HNO-ALI cultures recapitulate aspects of RSV and SARS-CoV-2 infection, including viral shedding, ciliary damage, innate immune responses, and mucus hyper-secretion. Next, we evaluated the feasibility of the HNO-ALI respiratory virus model system to test the efficacy of palivizumab to prevent RSV infection. Palivizumab was administered in the basolateral compartment (circulation) while viral infection occurred in the apical ciliated cells (airways), simulating the events in infants. In our model, palivizumab effectively prevented RSV infection in a concentration dependent manner. Thus, the HNO-ALI model can serve as an alternate to lung organoids to study respiratory viruses and testing therapeutics.

Accuracy and Reliability of Imaging Modalities for the Diagnosis and Quantification of Hill-Sachs Lesions: A Systematic Review

PURPOSE

To determine the reliability and accuracy of different imaging modalities in assessing Hill-Sachs lesions within the setting of anterior shoulder instability.

METHODS

A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines using the PubMed, Scopus, Embase, and Cochrane Library databases. The inclusion criteria were clinical trials or cadaveric studies that assessed the accuracy of humeral head bone loss imaging or reliability and English-language articles. The exclusion criteria were animal studies; imaging studies without measures of accuracy, reliability, or clinical predictive power; studies of shoulder injuries without humeral head bone loss; editorials; abstracts; reviews; case reports; and surveys. The search terms included "imaging" OR "radiographic" OR "CT" OR "MRI" AND "Hill-Sachs" OR "humeral head bone loss." Assessment of the methodologic quality of the included studies was performed using the original Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool.

RESULTS

Forty studies (2,560 shoulders) met the inclusion criteria and were assessed. For diagnosing the presence of Hill-Sachs lesions, computed tomography (CT) arthrography had the highest reported accuracy (median, 91%; range, 66%-100%). For the same assessment, CT arthrography also had the greatest reported sensitivity (median, 94%; range, 50%-100%). For the quantification of Hill-Sachs lesion parameters, reported intraobserver reliabilities were highest for 3-dimensional (3D) CT (intraclass correlation coefficient [ICC] range, 0.916-0.999), followed by 2-dimensional CT (ICC range, 0.858-0.861) and magnetic resonance imaging (MRI) (ICC range, 0.28-0.97). For the same quantification parameters, interobserver reliabilities were also reported for 3D CT (ICC range, 0.772-0.996), 2-dimensional CT (ICC range, 0.721-0.879), and MRI (κ range, 0.444-0.700). Intraobserver reliabilities for determining glenoid tracking were only reported for 3D CT (κ range, 0.730-1.00; ICC range, 0.803-0.901) and MRI (ICC range, 0.770-0.790).

CONCLUSIONS

This study shows that the current literature supports a variety of different imaging modalities that provide clinically acceptable accuracy in diagnosing and quantifying Hill-Sachs lesions, as well as determining whether they will cause persistent anterior shoulder instability. Furthermore, this systematic review justifies that further research is needed to help develop a treatment algorithm on the proper imaging modalities needed to help treat patients with anterior shoulder instability that is both reliable and financially acceptable.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through IV studies.

Initiation of Antiretroviral Therapy Before Pregnancy Reduces the Risk of Infection-related Hospitalization in Human Immunodeficiency Virus-exposed Uninfected Infants Born in a High-income Country

BACKGROUND

Epidemiological studies conducted in low- and high-income countries showed that infants exposed to maternal human immunodeficiency virus (HIV) have a high risk of severe infections. Immune alterations during fetal life have been proposed as a possible mechanism.

METHODS

This prospective study assessed the relative risk of hospitalization for infection in HIV-exposed uninfected (HEU) infants as compared to HIV-unexposed (HU) infants born in a high-income country (HIC). Markers of monocyte activation and levels of pathogen-specific antibodies were measured at birth to identify correlates of infant susceptibility.

RESULTS

There were 27 of 132 HEU infants and 14 of 123 HU infants hospitalized for infection during the first year of life (adjusted hazard ratio [aHR] 2.33, 95% confidence interval [CI] 1.10-4.97). Most of this increased risk was associated with the time of initiation of maternal antiretroviral therapy (ART). As compared to HU infants, the risk of hospitalization for infection of HEU infants was 4-fold higher when mothers initiated ART during pregnancy (aHR 3.84, 95% CI 1.69-8.71) and was not significantly increased when ART was initiated before pregnancy (aHR 1.42, 95% CI 0.58-3.48). The activation of newborn monocytes and the reduced transfer of maternal antibodies were most intense following ART initiation during pregnancy, and predicted the risk of infant hospitalization.

CONCLUSIONS

These observations indicate that initiation of maternal ART before pregnancy reduces the susceptibility of HEU infants born in a HIC to severe infections, and that this effect could be related to the prevention of immune alterations during fetal life.

Clinical characteristics and outcomes of respiratory syncytial virus infection in pregnant women

OBJECTIVE

To describe the clinical presentation and laboratory diagnosis of pregnant women with respiratory syncytial virus (RSV) infection.

METHODS

Pregnant women in their second and third trimester were enrolled during the course of routine prenatal care visits when they were asymptomatic within the preceding two weeks (healthy controls) or when they reported symptoms of acute respiratory illness (ARI) of ≤7 days of duration (cases). Clinical outcomes were assessed at enrollment and two weeks after. Re-enrollment was allowed. Nasal-pharyngeal secretions were evaluated for respiratory pathogens by real-time reverse transcription polymerase chain reaction (PCR). Sera were tested for RSV-specific antibody responses by Western Blot, microneutralization assay, and palivizumab competitive antibody assay.

RESULTS

During the 2015-2016 respiratory virus season, 7 of 65 (11%) pregnant women with ARI at their initial enrollment and 8 of 77 (10%) pregnant women with ARI during the study period (initial or re-enrollment) had PCR-confirmed RSV infection. Four (50%) PCR-confirmed RSV ARI cases reported symptoms of a lower respiratory tract illness (LRTI), one was hospitalized. Combining PCR and serology data, the RSV attack rate at initial enrollment was 12% (8 of 65), and 13% (10 of 77) based on ARI episodes. Among healthy controls, 28 of 88 (32%) had a Western Blot profile suggestive of a recent RSV infection either in the prior and/or current season.

CONCLUSION

RSV had an attack rate of 10-13% among ambulatory pregnant women receiving routine prenatal care during the respiratory virus season. The serology results of healthy controls suggest a potentially higher attack rate. Future studies should be aware of the combined diagnostic strength of PCR and serology to identify RSV infection. As maternal RSV vaccine candidates are evaluated to protect young infants, additional priority should be placed on outcomes of pregnant women.

Comparison of Visual Analog Pain Score Reported to Physician vs Nurse in Nonoperatively Treated Foot and Ankle Patients

BACKGROUND:

Patient-reported outcome measures (PROMs) are taking a more prominent role in orthopedics as health care seeks to define treatment outcomes. The visual analog scale (VAS) is considered a reliable measure of acute pain. A previous study found that operative candidates' VAS pain score was significantly higher when reported to the surgeon compared to the nurse. This study's aim is to examine whether this phenomenon occurs in patients that do not undergo an operative procedure. We hypothesized that patients' VAS pain scores reported to the surgeon vs the nurse would be the same.

METHODS:

This study is a retrospective cohort of 201 consecutive nonoperative foot and ankle patients treated by a single surgeon. Patients were asked to rate pain intensity by a nurse followed by the surgeon using a horizontal VAS, 0 "no pain" to 10 "worst pain." Differences in reported pain levels were compared with data from the previous cohort of 201 consecutive operative foot and ankle patients.

RESULTS:

The mean VAS score reported to the nurse was 3.2 whereas the mean VAS score reported to the surgeon was 4.2 ( P < .001). The mean difference in VAS scores reported for operative patients was 2.9, whereas the mean difference for nonoperative patients was 1.0 ( P < .001).

CONCLUSION:

This study found statistically significant differences between VAS pain scores reported to the surgeon vs the nurse in nonoperative patients. These results support the trend found in our previous study, where operative patients reported significantly higher pain scores to the surgeon vs the nurse. The mean difference between reported pain scores was significantly higher for operative patients compared to nonoperative patients.

LEVEL OF EVIDENCE:

Level III, comparative study.

Comparison of Visual Analog Pain Score Reported to Physician vs. Nurse, Part II

Category:

Ankle

Introduction/Purpose:

Patient reported outcome measures (PROMs) are taking a more prominent role in Orthopedics as researchers and health care networks seek to define treatment outcomes. However, interpretation and clinical applications of PROMs are still under investigation. The visual analogue scale (VAS) is considered a reliable and validated measure of acute pain. In a previous study, it was found that in surgical candidates the VAS pain score was significantly higher when reporting to the surgeon as opposed to the nurse. The aim of this current study is to examine whether this phenomenon occurs in patients that do not ultimately go on to have a surgical procedure. We hypothesize that there will be no difference in patient reporting to the surgeon versus the nursing staff.

Methods:

This study is a retrospective cohort of 201 consecutive non-surgical foot and ankle patients treated by a single surgeon. The patients were asked to rate their pain intensity by the nursing staff and then by the surgeon using a standard horizontal VAS 0 to 10, from “no pain” to worst pain.” Differences in reported pain levels were analyzed.

Results:

The mean VAS score reported to the nurse was 3.2 whereas the mean VAS score reported to the Surgeon was 4.2 (p<.001). Contrary to our hypothesis, there was a statistically significant difference in pain scores reported to the surgeon compared to the nurse. We then analyzed the mean difference of pain scores reported to surgeon and nurse for surgical versus non-surgical patients. The mean difference in VAS scores reported to physician and nurse for surgical patients was 2.87 whereas the mean difference for non-surgical patients was 1.00 (p < .001).

Conclusion:

The current study found statistically significant differences between VAS pain scores reported to the surgeon versus the nurse in non-surgical patients. These results support the trend found in our previous study which demonstrated discrepancies in patient pain reporting, with surgical patients reporting significantly higher pain scores to the surgeon versus the nurse. However, the mean difference between reported pain scores, to the providers, is significantly higher for surgical patients as compared to non-surgical patients. The cause of this phenomenon remains unclear, however, this study provides more information regarding patient reported VAS pain scores in an outpatient clinical setting.

Readability of Online Sources Regarding Meniscal Tears

Meniscal injuries are extremely common, with an incidence of 8.3 per 1,000 person/years in young, active individuals. Patients often turn to the internet to glean information about their injuries, and even to guide decision making about treatment. Much research has been done demonstrating that a reading level of eighth grade or lower is appropriate for accurately communicating written information to patients, yet medical practitioners often fail to meet this requirement. To better examine the information patients receive about meniscal injuries, we set out to evaluate the reading level and content of three commonly used search terms on the three search engines with the largest market share. The authors examined the keywords "meniscus tear," "meniscus tear treatment," and "knee pain meniscus" on the three highest market share search engines. The top 10 results from each search were included, and redundancies identified. Unique Web sites were evaluated for source, word count, reading level, and content including advertisements, diagrams, photographs, nonoperative and operative options, and accurate medical information. A total of 23 unique Web sites were identified in our search, including 13 public education sources, 6 academic institutions, and 4 private physicians/groups. Average grade levels of articles ranged from 9.4 to 14.2 (mean, 11.14; standard deviation [SD] 1.46), and Flesch-Kincaid reading ease scores ranged from 23.9 to 68.7 (mean, 55.31; SD, 10.11). Pages from public sources required the highest level of readability (11.6, 95% confidence interval [CI]: 9.8-13.2), which was significantly higher than private (11.0, 95% CI: 9.3, 12.7]) and academic (10.9, 95% CI: 8.9-12.9), p = 0.007 and p = 0.002, respectively. Further efforts to make appropriate health information available to patients are needed.

Stakeholders' perceptions of ways to support decisions about health insurance marketplace enrollment: a qualitative study

Background

Approximately 29 million individuals are expected to enroll in health insurance using the Patient Protection and Affordable Care Act (ACA) Marketplace by 2022. Those seeking health insurance struggle to understand insurance options and choose a plan that best suits their needs.

Methods

We interviewed stakeholders to identify the challenges associated with the ACA Marketplace health insurance enrollment and elicited feedback about what to include in health insurance decision support tools. Interviews were transcribed and themes were identified using inductive thematic analysis.

Results

Stakeholders stated that consumers felt frustrated by unclear terminology, high plan costs, and complex calculations required to assess costs. Consumers felt anxious about making the wrong choice and being unable to change plans within a calendar year. Stakeholders recommended using plain language tables defining complex terms, grouping information, and using engaging graphics to communicate information about health insurance. Stakeholders thought that narratives of how others made decisions about insurance might be helpful to consumers, but recommended that they be tailored to the needs of specific consumers.

Conclusion

Strategies that clarify health insurance terms using plain language and graphics, acknowledge concern associated with making the wrong choice, calculate and enable cost comparison, and tailor information to consumers’ unique needs could benefit those enrolling in ACA Marketplace plans, Narratives developed should be simple and inclusive enough for diverse populations.

Comment on: Hip fractures: public perceptions--are we jumping the gun?

McBride TJ, Panrucker S, Clothier JC Hip fractures: public perceptions. Ann R Coll Surg Engl 2011; 93: 67–70 doi: 10.1308/003588411X12851639107034

Rare digital tumours: two case reports and mini review

Masses within the fingers and hands are a common occurrence affecting patients of all ages. Although most will be benign conditions, rarer more aggressive tumours also occur. Two cases of rare hand tumours, a digital myofibroma and an aggressive digital papillary adenocarcinoma are reported here including a mini-review of the literature. Although these two cases are quite different they highlight the importance of having a high index of suspicion for the presence of malignant change in masses that have been quiescent for considerable periods of time and thus the need for histological diagnosis in masses resected from the hands. The myofibroma, like other conditions such as giant cell tumours, although benign can have very worrying clinical features, most notably bony destruction. The aggressive digital papillary adenocarcinoma conversely can appear benign clinically but biologically is very aggressive with a high propensity for local and distant spread.

Functional quantification of cyclosporine A and FK506 in human whole blood by flow cytometry, using the green fluorescent protein as an interleukin-2 reporter gene

The concentration of the immunosuppressive drugs cyclosporine A (CSA) and FK506 in biological fluids is routinely determined by antibody-based assays, which for several reasons do not give accurate information on the actual level of immunosuppression in the patient. To alleviate this problem, we developed a functional reporter gene assay which uses the enhancer fragment of the interleukin-2 promoter region driving the expression of the green fluorescent protein (GFP). This construct was stably transfected in the Jurkat human T lymphoblastoid cell line. Upon stimulation of the cell recipient, the GFP was produced and evaluated by flow cytometry. Immunosuppressants acting via inhibition of interleukin-2 synthesis, such as CSA or FK506, inhibited the production of GFP in a dose-dependent manner. This assay can be performed within a working day with a good reproducibility and was more sensitive than the antibody-based assays, since its detection limit was as low as 10 ng/ml for CSA and 0.5 ng/ml for FK506. We used it for the follow up of drug level present in the blood of transplanted patients, and compared the results with those obtained with the antibody-based assay routinely carried out in our hospital. The conclusions suggest that this assay is a valuable alternative to the presently available assays for the measurement of the immunosuppressive activity found in body fluids.

Development of perfluorocarbon tracer technology for underground leak location

A method has been developed for the atmospheric sampling and analysis of four perfluorocarbon tracer (PFT) compounds simultaneously at the parts per trillion (ppt) level. PFTs were pre-concentrated using adsorbent tube air sampling. Analysis was achieved by thermal desorption (TD) and gas chromatography (GC) with electron capture detection (ECD). Efficient separation of the PFTs from the other sample constituents was achieved by use of a capillary porous layer open tubular (PLOT) GC column without the need to cool the GC oven to sub-ambient temperatures using liquid coolants (M. de Bortoli and E. Pecchio, J. High Resolut. Chromatogr., 1985, 8, 422) or for a catalytic destruction step to remove interferents (T. W. D'Ottavio, R. W. Goodrich and R. N. Dietz, Environ. Sci. Technol., 1986, 20, 100). Results from test field trials with two volatile PFTs that were buried to simulate an underground leaking cable were successful. The PFTs were detected above ground level to pinpoint the leak position. The highest tracer concentrations were detected within 1 m of the simulated leak positions 2 days after tracer burial. The developed technology was applied to an oil leaking high voltage electricity cable. One PFT was added to the cable oil which enabled detection of the oil leak to within 3 m. The reported method has many advantages over currently used leak detection methods and could, in the future, be applied to the detection of underground leaks in a variety of cables and pipes.

Increased depolarization, prolonged recovery and reduced adaptation of the resting membrane potential in aged rat skeletal muscles following eccentric contractions

Previously it was shown in young-adult muscles that eccentric contractions (EC) produce a significant (24 h) depolarization of the resting membrane potential (RMP), and that in-vitro (Gd(3+)) and in-vivo (streptomycin) blockade of stretch activated ion channels (SAC) result in a partial repolarization of the RMP. The portion of the depolarization not restored by SAC blockade is believed to be from sarcolemmal injury. A second exposure to EC results in less depolarization and a more rapid recovery of the RMP. Aged muscles were subjected to the same EC protocol to test the hypotheses that: (1) Aged muscles will experience a more significant and prolonged depolarization of the RMP following EC. (2) The depolarization in aged muscles will occur by a greater contribution from membrane damage, rather than the opening of SAC. (3) The aged muscles will demonstrate a reduced capacity to adapt to EC, and will experience a similar degree of depolarization following repeated exposures to EC. The results indicate a significantly greater and longer lasting depolarization in aged compared to young-adult muscles. Blocking SAC did not produce a repolarization of the RMP in aged muscles. Aged muscles had a significantly reduced adaptive response to EC compared to young-adult. It is speculated that the different response in aged muscles results from a reduced number of functional SAC.

Adaptation of pregnant ewes to an exclusive onion diet

A diet consisting entirely of cull onions fed to pregnant ewes produced Heinz body hemolytic anemia in all sheep after 21 d. After 28 d of daily consumption of 20 kg of onions/ewe, the anemia stabilized, and for the remaining 74 d the packed cell volume increased in the majority of sheep, although it did not return to normal. Compared to control ewes fed an alfalfa and grain diet, the onion-fed ewes had comparable body condition scores and fleece weights. There was no significant difference (alpha = 0.05) in pregnancy or lambing rate, number of lambs born/ewe exposed, or number of lambs born/ewe lambing. Greater numbers of sulfate-reducing bacteria (Desulfovibrio spp) and more ruminal hydrogen sulfide were present in onion-fed sheep compared to controls. Although an average 27% reduction in packed cell volume and Heinz body anemia developed in the onion-fed ewes, on the basis of this study it appears that pregnant ewes may be fed a pure onion diet with minimal detrimental effects. This adaptation to a pure onion diet is in part likely due to the apparent ability of the sheep's rumen to quickly develop a population of sulfate-reducing bacteria that decrease the toxicity of onion disulfides.

The changing landscape of health care financing and delivery: how are rural communities and providers responding?

Rural communities have not kept pace with the recent dramatic changes in health care financing and organization. However, the Medicare provisions in the Balanced Budget Act of 1997 will require rural providers to participate in the new systems. Case studies revealed the degree of readiness for change in six rural communities and charted their progress along a continuum, as reflected in three sets of activities: the development of networking; the creation of new strategies for managing patient care; and the adoption of new methods for contracting with health insurers. Some communities had constructed highly integrated systems, whereas others were just beginning to change their billing practices; a few were signing contracts for capitated care, in contrast to those that were resisting discounts in current fee structures. These six rural areas still have considerable ground to cover before their health care organization and financing reach the levels achieved by urban communities.

A comparative volumetric analysis of the prefrontal cortex in human and baboon MRI

The proportion of prefrontal cortex in humans was compared to the proportion of prefrontal cortex in baboons (Papio anubis). Prefrontal cortex, dorsal prefrontal, orbital prefrontal cortex and total brain volumes were determined from magnetic resonance images of 20 healthy adult human females and 5 adult female baboons. Results showed that the proportion of prefrontal cortex volume relative to total brain volume in humans was significantly larger in humans than in baboons. The percentage of prefrontal cortex relative to total brain volume was 12.51 for humans and 10.68 for baboons. Similarly, the proportion of both dorsal and orbital prefrontal cortex volumes is larger in human brains. Relative to total brain volume, the percentages of dorsal and orbital prefrontal cortex was 8.22% and 4.29% respectively in humans and 7.21% and 3.47% in baboons. A regression analysis showed that the human prefrontal cortex was larger than would be predicted for a baboon of equal total brain volume. These results suggest that increased prefrontal lobe volume could underlie some of the differences between human and hominoid primates. On the other hand, the small magnitude of the difference might underlie similarities between the species and should encourage a search for other structures that are disproportionately larger in humans.

Total anorectal and partial vaginal reconstruction with dynamic graciloplasty and colonic vaginoplasty after extended abdominoperineal resection: report of a case

PURPOSE

Quality of life is altered after abdominoperineal resection, because of permanent iliac colostomy. Psychological rehabilitation is even more difficult after extended abdominoperineal resection to the vagina, because of the loss of both continence and sexual functions. We report the first case of total anorectal and vaginal reconstruction using dynamic graciloplasty and colonic vaginoplasty after extended abdominoperineal resection.

METHODS

A 46-year-old female underwent extended abdominoperineal resection with posterior colpectomy for a low rectal adenocarcinoma infiltrating the anal sphincter and vagina. Anorectal reconstruction was performed with coloperineal anastomosis and double dynamic graciloplasty. Vaginal reconstruction was performed using a 10-cm, isolated, rotated sigmoid loop. The procedure was performed in three stages, including abdominoperineal resection with reconstruction, implantation of the stimulator, and closure of the temporary ileostomy.

RESULTS

Resting and electrostimulated pressures of the neosphincter were 40 and 110 cm H2O respectively. Continence was achieved for formed stools two months after closure of the stoma, with spontaneous defecations (30-90 minutes). The patient experienced regular sexual activity six months after closure of the stoma.

CONCLUSION

This new original technique can be proposed in selected young females after extended abdominoperineal resection, to preserve continence, sexual activity, and body image.

Comparison of imaging geometries for diffuse optical tomography of tissue

Images produced in six different geometries with diffuse optical tomography simulations of tissue have been compared using a finite element-based algorithm with iterative refinement provided by the Newton-Raphson approach. The source-detector arrangements studied include (i) fan-beam tomography, (ii) full reflectance and transmittance tomography, as well as (iii) sub-surface imaging, where each of these three were examined in a circular and a flat slab geometry. The algorithm can provide quantitatively accurate results for all of the tomographic geometries investigated under certain circumstances. For example, quantitatively accurate results occur with sub-surface imaging only when the object to be imaged is fully contained within the diffuse projections. In general the diffuse projections must sample all regions around the target to be characterized in order for the algorithm to recover quantitatively accurate results. Not only is it important to sample the whole space, but maximal angular sampling is required for optimal image reconstruction. Geometries which do not maximize the possible sampling angles cause more noise artifact in the reconstructed images. Preliminary simulations using a mesh of the human brain confirm that optimal images are produced from circularly symmetric source-detector distributions, but that quantitatively accurate images can be reconstructed even with a sub-surface imaging, although spatial resolution is modest.

Instrumentation and design of a frequency-domain diffuse optical tomography imager for breast cancer detection

The instrument development and design of a prototype frequency-domain optical imaging device for breast cancer detection is described in detail. This device employs radio-frequency intensity modulated near-infrared light to image quantitatively both the scattering and absorption coefficients of tissue. The functioning components of the system include a laser diode and a photomultiplier tube, which are multiplexed automatically through 32 large core fiber optic bundles using high precision linear translation stages. Image reconstruction is based on a finite element solution of the diffusion equation. This tool for solving the forward problem of photon migration is coupled to an iterative optical property estimation algorithm, which uses a Levenberg-Marquardt routine with total variation minimization. The result of this development is an automated frequency-domain optical imager for computed tomography which produces quantitatively accurate images of the test phantoms used to date. This paper is a description and characterization of an automated frequency-domain computed tomography scanner, which is more quantitative than earlier systems used in diaphanography because of the combination of intensity modulated signal detection and iterative image reconstruction.

Expectations of nursing home use in the Health and Retirement Study: the role of gender, health, and family characteristics

Economic models of life cycle behavior suggest that expectations about future events may affect savings, insurance, and retirement planning. This article uses data from the first wave of the Health and Retirement Survey (HRS) to examine how personal characteristics and health conditions influence expectations of nursing home use. Subjective expectations of nursing home use are quite close to known probabilities of lifetime use. There are marked differences in the determinants of expectations for women and men that also conform to actual behavior. There is strong evidence that women and men incorporate what is known about nursing home risk into their own expectations, even many years prior to the time when they are most likely to need long-term care.

Prenatal auditory experience directs species-typical perceptual responsiveness in bobwhite quail chicks (Colinus virginianus)

The present study examined the role of the relationship between pre- and postnatal stimulus cues in directing perceptual preferences of bobwhite quail chicks. Bobwhite quail were exposed to either prenatal auditory or prenatal auditory-visual stimulation. Both prenatal auditory and auditory-visual stimulation resulted in accelerated responsiveness to combined postnatal auditory-visual cues. However, whether or not subjects displayed accelerated perceptual responsiveness depended on the relationship between the nature of the pre- and postnatal auditory stimuli used. These results demonstrate the salience of auditory cues in directing early postnatal perceptual behavior in precocial birds and help to explicate why prior research in this area has found that augmented prenatal sensory stimulation can result in either accelerated or decelerated patterns of perceptual functioning.

Specific postnatal auditory stimulation interferes with species-typical visual responsiveness in bobwhite quail chicks

The effects that a manipulation of sensory experience may have on perceptual development are likely to depend on a number of factors, including the amount and the type of stimulation provided. To examine the relative influence of these stimulation factors on early perceptual organization, this study exposed bobwhite quail hatchlings to augmented amounts of bobwhite chick distress calls, bobwhite chick contentment calls, domestic chicken distress calls, or no additional auditory stimulation during the first 72 hr following hatching. Results showed that bobwhite hatchlings exposed to bobwhite chick distress calls do not exhibit species-typical visual responsiveness to maternal cues. In contrast, bobwhite hatchlings exposed to bobwhite chick contentment calls, domestic chicken hatchling distress calls, or no augmented auditory stimulation exhibited species-typical auditory and visual responsiveness to maternal cues. These results demonstrate intermodal effects of postnatal sensory stimulation and suggest that specific types of postnatal auditory stimulation, rather than simply increased amount of stimulation, are necessary to interfere with species-typical intersensory functioning.

Risk of entering nursing homes for long versus short stays

Research on the risk of nursing home use has generally not distinguished between risk for long versus short stays. This paper presents an analysis of data from the 1982-84 National Long-Term Care Surveys to identify characteristics of disabled persons that predicted one or the other type of stay. Measures that are recognized to be strong predictors of nursing home use in general, such as dependencies in activities of daily living and cognitive impairment, were not significantly associated with admission for short stays. Results from the multivariate analysis were also used to make projections of lifetime risk of long and short stays. Approximately one-third of lifetime nursing home risk applies to stays of 90 days or less.

Lysosomes as key organelles in the pathogenesis of prion encephalopathies

The causation, structural origin, and mechanism of formation of spongiform lesions in transmissible encephalopathies are unknown. We have used immunogold electron microscopy to locate ubiquitin conjugates, hsp 70, and beta-glucuronidase (markers of the lysosomal compartment) and prion protein (PrP) in both control and scrapie-infected mouse brain. In scrapie-infected brain, lysosomes and lysosome-related structures (multivesicular and tubulovesicular dense bodies) are present in abnormally high numbers in neuronal cell processes. These structures contain PrP, together with the lysosomal markers ubiquitin conjugates, hsp 70, and beta-glucuronidase, which could also be identified spilling from tubulovesicular dense bodies into areas of early rarefaction in neuronal processes; we suggest that these areas of rarefaction are the precursor lesions of spongiform change. We advance the hypothesis that spongiform change is brought about by cytoskeletal disruption in neuronal processes caused by liberation of hydrolytic enzymes from lysosomes overloaded with the abnormal isoform of PrP (PrPsc). We suggest that the lysosomal system is probably acting as the bioreactor for processing of normal PrP to the abnormal isoform. The continuous production of increasing quantities of abnormal PrPsc in lysosome-related bodies will eventually cause disruption of the lysosomal membrane with destruction of the neuronal cytoskeleton and the initiation of vacuolation. Later, death of the cell will be associated with release of the PrPsc isoform into the extracellular environment. Repeated rounds of phagocytosis, lysosomal biogenesis of PrPsc, lysosomal membrane rupture, hydrolytic enzyme release, and neuronal lysis will lead to an exponential increase in cell damage and cell death.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutation spectrum of copper-induced DNA damage

The ability of metal ions to damage DNA and cause mutagenesis has been analyzed with reversion and forward mutation assays using single-stranded DNA templates. We previously reported that incubation of phi X174 am3 DNA with Fe2+ in vitro results in mutagenesis when the treated DNA is transfected into Escherichia coli spheroplasts (Loeb, L. A., James, E. A., Waltersdorph, A. M., and Klebanoff, S. J. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 3918-3922, 1988). We now extend these studies to other metal ions. Of the metal ions tested, copper ions were the most mutagenic; the frequency of mutants produced was equal to or greater than that produced by Fe2+. Mutagenesis by Cu+ was diminished by catalase, mannitol, and superoxide dismutase suggesting the involvement of H2O2, hydroxyl ions, and superoxide, respectively. However, the findings that Cu+ and Cu2+ are nearly equally mutagenic and that the mutagenic activities are not completely inhibited by oxygen free radical scavengers make it unlikely that the mechanism for mutagenesis is simply the production of hydroxyl free radicals. The spectra of mutations produced by either copper ion using the lacZ gene as a target are very similar and differ from those reported with other agents. The predominant mutagenic sequence changes are single-base substitutions, the most frequent being replacement of a template C by a T. This transition presumably results from mispairing of an altered C with deoxyadenosine. Copper-induced mutations are not randomly distributed. Instead, they are found predominantly in clusters suggesting direct interaction of copper ions with specific nucleotide sequences in DNA. Evidence is considered that the high frequency of C----T transitions may be a common manifestation of DNA damage by oxygen radicals.

Pulmonary function studies in a newborn with congenital laryngeal atresia

Congenital laryngeal atresia is a rare cause of upper airway obstruction that leads to death unless a surgical airway is immediately established. We were able to resuscitate a baby boy with laryngeal atresia by the placement of an 18-gauge plastic intravenous cannula into the trachea, connected in turn to a 3-mL syringe without the plunger, and then to the connector to a 7.0-mm endotracheal tube. This arrangement allowed hand ventilation and sufficient gas exchange until a formal tracheotomy was established minutes later. The baby boy had deficient abdominal musculature (without cryptorchidism or obstructive uropathy), bilateral inguinal hernias, and idiopathic hypercalcemia (since spontaneously resolved), but no other major anomalies. His survival allowed measurements of pulmonary function in lungs distal to an obstructed upper airway, an arrangement that mimics experiments that examine the influence of lung fluid volume and pressure on developing lungs. The baby's lungs had a forced vital capacity (FVC) in the upper limits of normal (not grossly enlarged lungs seen in newborn animals undergoing ligation of the trachea in utero). Maximal expiratory flow at 25% of FVC from residual volume (MEF25) was decreased, indicating airway obstruction involving smaller airways. Although direct laryngoscopy failed to find a opening in the larynx, some communication probably existed during development to allow some drainage of lung fluid. This opening, in the form of a persistent pharyngoglottic duct, prevented gross distention of the developing lung, but provided an insufficient airway at birth.

A randomized controlled trial of glucocorticoid prophylaxis against experimental rhinovirus infection

The effects of combined intranasal and systemic glucocorticoid steroids on the local inflammatory response, and symptoms due to experimental rhinovirus infection were studied in 45 adults randomized to prophylaxis with either placebo or steroids. Intranasal beclomethasone (168 micrograms twice a day) was begun 4 days before viral challenge and continued 5 days after challenge. Oral prednisone (30 mg twice daily) was given for 3 days beginning 1 day before challenge. During the first 48 h after viral inoculation, nasal obstruction, nasal mucus weights, and kinin concentrations in nasal lavages were lower in steroid recipients, but subsequent increases in these variables in the steroid group resulted in no significant cumulative differences between treatment groups. These data suggest that steroid prophylaxis may suppress nasal inflammation and cold symptoms during the first 2 days in experimental rhinovirus colds.

Lingual thyroid in a young infant presenting as airway obstruction: report of a case

A case of lingual thyroid causing airway obstruction in a 3-month-old infant is reported. Endoscopic examination for stridor disclosed an obstructing 4 X 3 cm base of tongue lesion. Nuclear isotope scanning confirmed this to be the only thyroid tissue present in this patient. A transoral excision using the CO2 laser was performed without complication. Only one other case of airway obstruction in the young infant secondary to lingual thyroid has been reported, that being the original case description in 1869. A review of the embryology and discussion of the suggested therapies is presented. The rationale for use of the CO2 laser for this lesion is discussed.

An assessment of preoperative coagulation screening for tonsillectomy and adenoidectomy

Preoperative coagulation studies are commonly employed in order to try to identify the 2-4% of all patients undergoing tonsillectomy/adenoidectomy surgery who experience hemorrhagic complications. In an atmosphere of increasing cost consciousness, evaluation of the efficacy of screening tests is warranted. The records of 994 out of 1050 patients consecutively scheduled for tonsillectomy, adenoidectomy or T&A over a 2.5-year period were retrospectively reviewed in order to determine the usefulness of partial thromboplastin (PTT) and prothrombin time (PT) screening in predicting surgical and postsurgical bleeding. For patients with no history or clinical signs indicating possible bleeding disorder, preoperative PT and PTT failed to predict bleeding as an outcome. Also no patients were identified in this series to have previously undiagnosed coagulopathies on the basis of screening PT/PTT. The purpose of any screening test is to identify disease early enough for therapeutic intervention to be effective. Although preoperative PT/PTT will occasionally identify an unsuspected von Willebrand's or other coagulopathy, the prevalence of bleeding disorders in patients with negative history and examination is low enough that PT/PTT has essentially a zero predictive value for surgical bleeding. Screening PT/PTT should therefore be reserved for patients with known or suspected coagulopathies.

Pseudotumor of the pterygomaxillary space presenting as anesthesia of the mandibular nerve

Pseudotumor is a term used to describe a space occupying inflammatory lesion which mimics a true neoplastic process in its clinical presentation. In this paper, we report a pseudotumor of the pterygomaxillary space that presented with anesthesia and paralysis of the mandibular nerve. The importance of this case is to call attention to pseudotumors as a clinical entity and to document a case of an extraordinarily aggressive variant that required a surgical approach usually reserved for malignant tumors.