Optogenetics Sheds Light on Brown and Beige Adipocytes

Excessive food intake leads to lipid accumulation in white adipose tissue, triggering inflammation, cellular stress, insulin resistance, and metabolic syndrome. In contrast, the dynamic energy expenditure and heat generation of brown and beige adipose tissue, driven by specialized mitochondria, render it an appealing candidate for therapeutic strategies aimed at addressing metabolic disorders. This review examines the therapeutic potential of brown and beige adipocytes for obesity and metabolic disorders, focusing on recent studies that employ optogenetics for thermogenesis control in these cells. The findings delve into the mechanisms underlying UCP1-dependent and UCP1-independent thermogenesis and how optogenetic approaches can be used to precisely modulate energy expenditure and induce thermogenesis. The convergence of adipocyte biology and optogenetics presents an exciting frontier in combating metabolic disorders and advancing our understanding of cellular regulation and energy balance.

Restoring Carboxylates on Highly Modified Alginates Improves Gelation, Tissue Retention and Systemic Capture

Alginate hydrogels are gaining traction for use in drug delivery, regenerative medicine, and as tissue engineered scaffolds due to their physiological gelation conditions, high tissue biocompatibility, and wide chemical versatility. Traditionally, alginate is decorated at the carboxyl group to carry drug payloads, peptides, or proteins. While low degrees of substitution do not cause noticeable mechanical changes, high degrees of substitution can cause significant losses to alginate properties including complete loss of calcium cross-linking. While most modifications used to decorate alginate deplete the carboxyl groups, we propose that alginate modifications that replenish the carboxyl groups could overcome the loss in gel integrity and mechanics. In this report, we demonstrate that restoring carboxyl groups during functionalization maintains calcium cross-links as well as hydrogel shear-thinning and self-healing properties. In addition, we demonstrate that alginate hydrogels modified to a high degree with azide modifications that restore the carboxyl groups have improved tissue retention at intramuscular injection sites and capture blood-circulating cyclooctynes better than alginate hydrogels modified with azide modifications that deplete the carboxyl groups. Taken together, alginate modifications that restore carboxyl groups could significantly improve alginate hydrogel mechanics for clinical applications. STATEMENT OF SIGNIFICANCE: Chemical modification of hydrogels provides a powerful tool to regulate cellular adhesion, immune response, and biocompatibility with local tissues. Alginate, due to its biocompatibility and easy chemical modification, is being explored for tissue engineering and drug delivery. Unfortunately, modifying alginate to a high degree of substitution consumes carboxyl group, which are necessary for ionic gelation, leading to poor hydrogel crosslinking. We introduce alginate modifications that restore the alginate's carboxyl groups. We demonstrate that modifications that reintroduce carboxyl groups restore gelation and improve gel mechanics and tissue retention. In addition to contributing to a basic science understanding of hydrogel properties, we anticipate our approach will be useful to create tissue engineered scaffolds and drug delivery platforms.

Manipulating twisted electrons in strong-field ionization

We investigate the discrete orbital angular momentum (OAM) of photoelectrons freed in strong-field ionization. We use these 'twisted' electrons to provide an alternative interpretation on existing experimental work of vortex interferences caused by strong field ionization mediated by two counter-rotating circularly polarized pulses separated by a delay. Using the strong field approximation, we derive an interference condition for the vortices. In computations for a neon target we find very good agreement of the vortex condition with photoelectron momentum distributions computed with the strong field approximation, as well as with the time-dependent methods Qprop and R-Matrix. For each of these approaches we examine the OAM of the photoelectrons, finding a small number of vortex states localized in separate energy regions. We demonstrate that the vortices arise from the interference of pairs of twisted electron states. The OAM of each twisted electron state can be directly related to the number of arms of the spiral in that region. We gain further understanding by recreating the vortices with pairs of twisted electrons and use this to determine a semiclassical relation for the OAM. A discussion is included on measuring the OAM in strong field ionization directly or by employing specific laser pulse schemes as well as utilizing the OAM in time-resolved imaging of photo-induced dynamics.

Ultrasonic Microplotting of Microgel Bioinks

Material scaffolds that mimic the structure, function, and bioactivity of native biological tissues are in constant development. Recently, material scaffolds composed of microgel particles have shown promise for applications ranging from bone regeneration to spheroid cell growth. Previous studies with poly N-isopropylacrylamide microgel scaffolds utilized a layer-by-layer (LBL) technique where individual, uniform microgel layers are built on top of each other resulting in a multilayer scaffold. However, this technique is limited in its applications due to the inability to control microscale deposition or patterning of multiple particle types within a microgel layer. In this study, an ultrasonic microplotting technique is used to address the limitations of LBL fabrication to create patterned microgel films. Printing parameters, such as bioink formulation, surface contact angle, and print head diameter, are optimized to identify the ideal parameters needed to successfully print microgel films. It was found that bioinks composed of 2 mg/mL of microgels and 20% polyethylene glycol by volume (v/v), on bovine serum albumin-coated glass, with a print head diameter of 50 μm resulted in the highest quality prints. Patterned films were created with a maximum resolution of 50 μm with the potential for finer resolutions to be achieved with alternative bioink compositions and printing parameters. Overall, ultrasonic microplotting can be used to create more complex microgel films than is possible with LBL techniques and offers the possibility of greater printing resolution in 3D with further technology development.

Analysis of the structural and mechanical effects of procoagulant agents on neonatal fibrin networks following cardiopulmonary bypass

Essentials The standard of care (SOC) for treating neonatal bleeding is transfusion of adult blood products. We compared neonatal clots formed with cryoprecipitate (SOC) to two procoagulant therapies. The current SOC resulted in clots with increased stiffness and decreased fibrinolytic properties. Procoagulant therapies may be a viable alternative to SOC treatment for neonatal bleeding. SUMMARY: Background Bleeding is a serious complication of neonates undergoing cardiopulmonary bypass (CPB) and associated with substantial morbidity and mortality. Bleeding is addressed through the transfusion of adult blood products, including platelets and cryoprecipitate. However, significant differences exist between neonatal and adult clotting components, specifically fibrinogen. Our recent ex vivo studies have shown that neonatal fibrinogen does not fully integrate with adult fibrinogen, leading to decreased susceptibility to fibrinolysis. These differences may contribute to ineffective clot formation and/or an increased risk of thrombosis. A need exists to identify more effective and safer methods to promote clotting in neonates. Objectives Procoagulant agents, such as prothrombin complex concentrates (PCCs) and recombinant activated factor VII (rFVIIa), are being used off-label to treat excessive bleeding in neonates after CPB. Because these agents stimulate endogenous fibrin formation, we hypothesize that their addition to post-CPB neonatal plasma will better recapitulate native clot properties than cryoprecipitate. Methods We analyze the structural, mechanical and degradation properties of fibrin matrices formed by neonatal plasma collected after CPB in the presence of an activated four-factor (F) PCC (FEIBA), rFVIIa, or cryoprecipitate using confocal microscopy, atomic force microscopy and a fluidics-based degradation assay. Results The ex vivo addition of FEIBA and rFVIIa to post-CPB neonatal plasma resulted in enhanced clot networks with differences in fibrin alignment, mechanics and degradation properties. Conclusions Our results suggest that these procoagulant agents could be used as an alternative to the transfusion of adult fibrinogen for the treatment of bleeding after CPB in neonates.

Extreme-Ultraviolet-Initated High-Order Harmonic Generation: Driving Inner-Valence Electrons Using Below-Threshold-Energy Extreme-Ultraviolet Light

We propose a novel scheme for resolving the contribution of inner- and outer-valence electrons in extreme-ultraviolet (XUV)-initiated high-harmonic generation in neon. By probing the atom with a low-energy (below the 2s ionization threshold) ultrashort XUV pulse, the 2p electron is steered away from the core, while the 2s electron is enabled to describe recollision trajectories. By selectively suppressing the 2p recollision trajectories, we can resolve the contribution of the 2s electron to the high-harmonic spectrum. We apply the classical trajectory model to account for the contribution of the 2s electron, which allows for an intuitive understanding of the process.

Effect of castration timing and oral meloxicam administration on growth performance, inflammation, behavior, and carcass quality of beef calves

Beef bull calves (n = 62) were assigned randomly, within sire breed, to 1 of 4 treatments at birth. Treatments were 1) surgical castration near birth, 2) surgical castration near birth with oral administration of meloxicam (1 mg/kg BW), 3) surgical castration at weaning (WNG), or 4) surgical castration at weaning with oral administration of meloxicam (1 mg/kg BW; WMX). A subset of calves (n = 7/treatment group) were selected randomly near birth for blood collection, behavioral analyses, and rectal temperature (RT) records for a 7-d postcastration period on d 0 (birth), 1, 3, and 7, and on d 214 (weaning), 214 + 6 h, 215, 217, 221, and 228. Calf standing and lying activity were monitored from the same subsets by recording x- and y-axis positions of an accelerometer attached to the right metatarsus for 7 d postcastration. Calf BW was recorded throughout the entire production cycle, and carcass data were collected at slaughter. For statistical analyses, bulls left intact at birth were considered a positive control (BUL) for observations that occurred before their treatment application at weaning; likewise, bulls castrated at birth were considered a negative control (STR) during postweaning observations. No difference (P > 0.88) occurred in ADG between treatments throughout the preweaning period (d 0 to 214); however, 56-d postweaning ADG was greatest ( P= 0.02) in STR, intermediate in WMX, and least in WNG. At weaning, haptoglobin (Hp) was greater (P ≤ 0.005) for WNG and WMX compared to STR on d 214+6 h, 215, and 217, and Hp was greater (P = 0.05) in WNG compared to WMX on d 217. Neutrophils increased (P < 0.001) and red blood cells decreased (P ≤ 0.03) for WNG and WMX on d 214+6 h and 217, respectively. Postweaning behavior observations indicated that STR calves spent the least proportion of time standing (P = 0.002) when compared to WNG and WMX. Furthermore, WMX calves exhibited a greater proportion of time spent standing (P = 0.03) compared to WNG. Grazing and finishing phase ADG and carcass measurements did not differ (P ≥ 0.24) across treatments. In this study, surgical castration at weaning, but not near birth, altered the acute phase response, behavior, and growth performance. Oral meloxicam reduced serum Hp and improved ADG briefly when administered to calves castrated at weaning. Oral administration of meloxicam may be efficacious for mitigating some of the stress and inflammation associated with castration of weaning-age bull calves.

Mucosal production of uric acid by airway epithelial cells contributes to particulate matter-induced allergic sensitization

Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM10-induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma.

Inhibition of LtxA toxicity by blocking cholesterol binding with peptides

The leukotoxin (LtxA) produced by Aggregatibacter actinomycetemcomitans kills host immune cells, allowing the bacterium to establish an ecological niche in the upper aerodigestive tract of its human host. The interaction of LtxA with human immune cells is both complex and multifaceted, involving membrane lipids as well as cell-surface proteins. In the initial encounter with the host cell, LtxA associates with lymphocyte function-associated antigen-1, a cell surface adhesion glycoprotein. However, we have also demonstrated that the toxin associates strongly with the plasma membrane lipids, specifically cholesterol. This association with cholesterol is regulated by a cholesterol recognition amino acid consensus (CRAC) motif, with a sequence of (334) LEEYSKR(340), in the N-terminal region of the toxin. Here, we have demonstrated that removal of cholesterol from the plasma membrane or mutation of the LtxA CRAC motif inhibits the activity of the toxin in THP-1 cells. To inhibit LtxA activity, we designed a short peptide corresponding to the CRAC(336) motif of LtxA (CRAC(336WT)). This peptide binds to cholesterol and thereby inhibits the toxicity of LtxA in THP-1 cells. Previously, we showed that this peptide inhibits LtxA toxicity against Jn.9 (Jurkat) cells, indicating that peptides derived from the cholesterol-binding site of LtxA may have a potential clinical applicability in controlling infections of repeats-in-toxin-producing organisms.

Membrane association and destabilization by Aggregatibacter actinomycetemcomitans leukotoxin requires changes in secondary structures

Aggregatibacter actinomycetemcomitans is a common inhabitant of the upper aerodigestive tract of humans and non-human primates and is associated with disseminated infections, including lung and brain abscesses, pediatric infective endocarditis, and localized aggressive periodontitis. Aggregatibacter actinomycetemcomitans secretes a repeats-in-toxin protein, leukotoxin, which exclusively kills lymphocyte function-associated antigen-1-bearing cells. The toxin's pathological mechanism is not fully understood; however, experimental evidence indicates that it involves the association with and subsequent destabilization of the target cell's plasma membrane. We have long hypothesized that leukotoxin secondary structure is strongly correlated with membrane association and destabilization. In this study, we tested this hypothesis by analysing lipid-induced changes in leukotoxin conformation. Upon incubation of leukotoxin with lipids that favor leukotoxin-membrane association, we observed an increase in leukotoxin α-helical content that was not observed with lipids that favor membrane destabilization. The change in leukotoxin conformation after incubation with these lipids suggests that membrane binding and membrane destabilization have distinct secondary structural requirements, suggesting that they are independent events. These studies provide insight into the mechanism of cell damage that leads to disease progression by A. actinomycetemcomitans.

The effects of temperature and dissolved oxygen on antioxidant defences and oxidative damage in the fathead minnow Pimephales promelas

Fathead minnows Pimephales promelas maintained at 25° C for 6 h had significantly higher superoxide dismutase (SOD) activity than fish maintained at 7 or 32° C, but hypoxic conditions (3 mg l(-1) O2 ) over the same time period did not affect SOD activity. Fish in better body condition (length-adjusted mass) had higher SOD activity. In a separate experiment, P. promelas maintained at three water temperatures (7, 23 and 32° C) for 31 days did not differ in liver acrolein, a biomarker of oxidative stress.

Interference between competing pathways in atomic harmonic generation

We investigate the influence of the autoionizing 3s3p(6)nℓ resonances on the fifth harmonic generated by 200-240 nm laser fields interacting with Ar. To determine the influence of a multielectron response we develop the capability within time-dependent R-matrix theory to determine the harmonic spectra generated. The fifth harmonic is affected by interference between the response of a 3s electron and the response of a 3p electron, as demonstrated by the asymmetric profiles in the harmonic yields as functions of wavelength.

Aggregatibacter actinomycetemcomitans leukotoxin is post-translationally modified by addition of either saturated or hydroxylated fatty acyl chains

Aggregatibacter actinomycetemcomitans, a common inhabitant of the human upper aerodigestive tract, produces a repeat in toxin (RTX), leukotoxin (LtxA). The LtxA is transcribed as a 114-kDa inactive protoxin with activation being achieved by attachment of short chain fatty acyl groups to internal lysine residues. Methyl esters of LtxA that were isolated from A. actinomycetemcomitans strains JP2 and HK1651 and subjected to gas chromatography/mass spectrometry contained palmitoyl (C16:0, 27-29%) and palmitolyl (C16:1 cis Δ9, 43-44%) fatty acyl groups with smaller quantities of myristic (C14:0, 14%) and stearic (C18:0, 12-14%) fatty acids. Liquid chromatography/mass spectrometry of tryptic peptides from acylated and unacylated recombinant LtxA confirmed that Lys(562) and Lys(687) are the sites of acyl group attachment. During analysis of recombinant LtxA peptides, we observed peptide spectra that were not observed as part of the RTX acylation schemes of either Escherichia coliα-hemolysin or Bordetella pertussis cyclolysin. Mass calculations of these spectra suggested that LtxA was also modified by the addition of monohydroxylated forms of C14 and C16 acyl groups. Multiple reaction monitoring mass spectrometry identified hydroxymyristic and hydroxypalmitic acids in wild-type LtxA methyl esters. Single or tandem replacement of Lys(562) and Lys(687) with Arg blocks acylation, resulting in a >75% decrease in cytotoxicity when compared with wild-type toxin, suggesting that these post-translational modifications are playing a critical role in LtxA-mediated target cell cytotoxicity.

Characterization of HKE2: an ancient antigen encoded in the major histocompatibility complex

Genes at the centromeric end of the human leukocyte antigen region influence adaptive autoimmune diseases and cancer. In this study, we characterized protein expression of HKE2, a gene located in the centromeric portion of the class II region of the major histocompatibility complex encoding subunit 6 of prefoldin. Immunohistochemical analysis using an anti-HKE2 antibody indicated that HKE2 protein expression is dramatically upregulated as a consequence of activation. In a tissue microarray and in several tumors, HKE2 was overexpressed in certain cancers compared with normal counterparts. The localization of the HKE2 gene to the class II region, its cytoplasmic expression and putative protein-binding domain suggest that HKE2 may function in adaptive immunity and cancer.

Pooling and PCR as a method to combat low frequency gene targeting in mouse embryonic stem cells

The introduction of germ line modifications by gene targeting in mouse embryonic stem (ES) cells has proven a fundamental technology to relate genes to mammalian biology. Critical aspects required for successful gene targeting have traditionally been experimental enhancements that increase the frequency or detection of homologous recombination within ES cells; however, the utilization of such methods may still result in the failed isolation of a positively targeted ES cell clone. In this study, we discuss the current enhancement methods and describe an ES cell pooling strategy that maximizes the ability to detect properly targeted ES cells regardless of an inherent low targeting efficiency. The sensitivity required to detect correctly targeted events out of a pool of ES cell clones is provided by polymerase chain reaction (PCR), and only those pools containing positives need to be expanded and screened to find individually targeted clones. This method made it possible to identify targeted clones from a screen of approximately 2,300 ES cell colonies by performing only 123 PCR reactions. This technically streamlined approach bypasses the need to troubleshoot and re-engineer an existing targeting construct that is functionally suitable despite its low targeting frequency.

Quantitative gene expression profiling implicates genes for susceptibility and resistance to alveolar bone loss

Periodontal disease is one of the most prevalent chronic inflammatory diseases. There is a genetic component to susceptibility and resistance to this disease. Using a mouse model, we investigated the progression of alveolar bone loss by gene expression profiling of susceptible and resistant mouse strains (BALB/cByJ and A/J, respectively). We employed a novel and sensitive quantitative real-time PCR method to compare basal RNA transcription of a 48-gene set in the gingiva and the spleen and the subsequent changes in gene expression due to Porphyromonas gingivalis oral infection. Basal expression of interleukin-1 beta (Il1b) and tumor necrosis factor alpha (Tnf) mRNA was higher in the gingiva of the susceptible BALB/cByJ mice than in the gingiva of resistant A/J mice. Gingival Il1b gene expression increased further and Stat6 gene expression was turned on after P. gingivalis infection in BALB/cByJ mice but not in A/J mice. The basal expression of interleukin-15 (Il15) in the gingiva and the basal expression of p-selectin (Selp) in the spleen were higher in the resistant A/J mice than in the susceptible BALB/cByJ mice. In the resistant A/J mice the expression of no genes detectably changed in the gingiva after infection. These results suggest a molecular phenotype in which discrete sets of differentially expressed genes are associated with genetically determined susceptibility (Il1b, Tnf, and Stat6) or resistance (Il15 and Selp) to alveolar bone loss, providing insight into the genetic etiology of this complex disease.

Allergic reactions to isosulfan blue during sentinel node biopsy--a common event

BACKGROUND

Sentinel lymph node (SLN) dissection in the management of high-risk melanoma and other cancers, such as breast cancer, has recently increased in use. The procedure identifies an SLN by intradermal or intraparenchymal injection of an isosulfan blue dye, a radiocolloid, or both around the primary malignancy.

METHODS

At the time of selective SLN mapping, 3 to 5 mL of isosulfan blue was injected either intradermally or intraparenchymally around the primary malignancy. From October 1997 to May 2000, 267 patients underwent intraoperative lymphatic mapping with the use of both isosulfan 1% blue dye and radiocolloid injection. Five cases with adverse reactions to isosulfan blue were reviewed.

RESULTS

We report 2 cases of anaphylaxis and 3 cases of "blue hives" after injection with isosulfan blue of 267 patients who had intraoperative lymphatic mapping by the procedure described above. The 2 patients with anaphylaxis experienced cardiovascular collapse, erythema, perioral edema, urticaria, and uvular edema. The blue hives in 3 patients resolved and transformed to blue patches during the course of the procedures.

CONCLUSIONS

The incidence of allergic reactions in our series was 2.0%. As physicians expand the role of SLN mapping, they should consider the use of histamine blockers as prophylaxis and have emergency treatment readily available to treat the life- threatening complication of anaphylactic reaction.

An assessment of various household food security measures in Hawaiì has implications for national food security research and monitoring

The Core Food Security Module (CFSM), the national food security monitoring tool, requires three affirmative responses to categorize households as food insecure. If this tool is unreliable or inaccurate, vulnerable segments of our population may be adversely affected. The objectives of the present study were to assess the credibility of applying the CFSM categorical measure to a population sample from Hawaiì and to assess the concurrent validity of the CFSM, the new face-valid measure and measures adapted from the Radimer/Cornell (RC) measure and Community Childhood Hunger Identification Project. The sample included 1469 respondents gathered through a statewide telephone sample and 144 food pantry recipients. Responses to the 18 CFSM questions were used to create all four measures. The credibility of the CFSM categorical measure was also assessed via comparisons with individual items and with the 1995 national modal CFSM response pattern. Categorical measures were compared across food security prevalence estimates and indices of income and vegetable intake and with the CFSM scale measure. Differences in the modal response pattern between samples affected CFSM categorization. Only 36% of households followed the Hawaiì modal response pattern, and categorization was not consistent with the content of key items. Although 85% of the households were classified as food secure by the CFSM, only 78% were classified as food secure with each of the other food security measures. Concurrent validity of all measures was confirmed. A reassessment of the national CFSM categorical measure appears warranted.

The Hawaii Diet: ad libitum high carbohydrate, low fat multi-cultural diet for the reduction of chronic disease risk factors: obesity, hypertension, hypercholesterolemia, and hyperglycemia

OBJECTIVE

The purpose of this study was to determine the health effects of a high carbohydrate, low fat multi-cultural traditional diet, The Hawaii Diet, fed ad libitum to an adult population.

METHODS

Twenty-two adults recruited from various cultural backgrounds in Hawaii were fed, without calorie or portion size restriction, the Hawaii Diet for 21 days. The Hawaii Diet, based on familiar traditional foods from different cultures, is high in complex carbohydrate (77% of calories), low in fat (12% of calories), and moderate in protein (11% of calories). Participants were encouraged to eat to satiety.

RESULTS

There was a significant weight loss on The Hawaii Diet averaging 10.8 lbs (23.8 kg) (P < .0001). Blood pressure was decreased from an average of 136.0/82.7 mm Hg to 125.5/78.9 mm Hg yielding a significant decrease of 10.4 mm Hg for systolic (P < .01). Beginning diastolic levels were normal so decreases in these values were not significant. Average lipid values also decreased with total serum cholesterol being significantly reduced from 205.3 to 156.9 mg/dl (P < .0001); LDL from 125.9 to 94.9 mg/dl (P < .001); and HDL from 38.3 to 31.3 mg/dl (P < .0005). Triglycerides (238.7 to 152.2 mg/dl) and the Chol:HDL ratio (5.8 to 5.2) improved at marginally significant levels (P < .08). There was also a significant reduction in blood glucose levels from 112.2 to 91.5 mg/dL (P < .01).

CONCLUSION

The Hawaii Diet consisting of high carbohydrate, low fat ethnic meals appears to have a beneficial influence on weight loss and in decreasing systolic blood pressure, total cholesterol, LDL, and blood glucose values. Marginal improvement occurred for triglyceride levels. There was also a significant drop in HDL levels, however, the Chol:HDL was ratio did not increase. Further studies of longer duration with a control group should be conducted to test the effectiveness of The Hawaii Diet in maintaining these health benefits over a longer period of time.

Lupus erythematosus and nutrition: a review of the literature

The purpose of this review was to search the scientific literature for dietary compounds that alleviate or exacerbate symptoms of lupus erythematosus (LE) in both animal and human models. A detailed literature review was undertaken to find articles showing a relationship between LE and nutrition by using MEDLINE/INDEX MEDICUS (1950-March 2000) for English-language articles, followed by cross-referencing. Aggravating substances appear to include excess calories, excess protein, high fat (especially saturated and omega-6 polyunsaturated fatty acids), zinc, iron, and L-canavanine found in alfalfa tablets. Possible beneficial dietary compounds include vitamin E, vitamin A (beta-carotene), selenium, fish oils (omega-3 polyunsaturated fatty acids), evening primrose oil, flaxseed, a plant herb (Tripterygium wilfordii), dehydroepiandrosterone, and calcium plus vitamin D (if taking corticosteroids). Some people with systemic LE placed on food allergy elimination diets reported improvement in their LE symptoms; however, this may be related to a decrease of other substances in the diet. Also, although no direct evidence was reported on the beneficial effects of either bromelain or a vegetarian diet (possibly allowing fish), it is suggested that they might be beneficial. Limitations to this research are that the findings are based on relatively few studies, many of which were without control groups or extrapolated from animal models. No large-scale studies have been performed with LE patients to substantiate the benefit, if any, of these individual dietary interventions, and if they were conducted, the remission and exacerbation pattern of LE may interfere with elucidating their effectiveness. Also, dietary changes should not be attempted without a physician's approval/monitoring.

Facial frequency manipulation normalizes face discrimination in AD

People with AD have deficient contrast sensitivity and impaired face discrimination. The authors presented photographs of unfamiliar faces of three different sizes to enhance the low, middle, or high facial frequency information (cycles per face). Patients with AD demonstrated normal discrimination of small faces only, indicating that impaired contrast sensitivity at low facial frequencies contributes to their poor face discrimination.

Fragile self-esteem in children and its associations with perceived patterns of parent-child communication

We examined the extent to which 11- to 12-year-old children's (N = 174) self-esteem (SE) stability and level related to their perceptions of various aspects of parent-child communication. Compared to children with stable SE, children with unstable SE reported that their fathers were more critical and psychologically controlling, and less likely to acknowledge their positive behaviors or to show their approval in value-affirming ways. Likewise, children with low SE reported that their fathers exhibited these qualities to a greater extent than did children with high SE. In addition, fathers of children with stable high SE were viewed as especially good at problem solving. Children's SE level related to perceptions of mothers' communication styles very similarly to how it did with fathers'; with respect to SE stability, however, relationships were generally less consistent and frequently absent. Discussion centered on the role of parent-child communication in promoting unstable SE.

Behavioural and emotional difficulties in students attending schools for children and adolescents with severe intellectual disability

BACKGROUND

For several decades, researchers and clinicians have been aware of an increased prevalence of psychiatric disorder in children with intellectual disability. However, there are few research studies exploring this issue.

METHODS

The parents of 123 children attending schools for children with 'severe learning difficulties' completed the Developmental Behaviour Checklist (DBC) in order to identify those children with clinically significant behavioural and emotional problems. Comparisons were made with norms for the DBC and a range of child variables were investigated as possible correlates of disorder.

RESULTS

Some 50.4% of the children scored above the cut-off on the DBC for psychiatric disorder. The child's severity of physical disability was related most strongly to parental ratings of behavioural and emotional problems. There were also effects for the child's age and the absence of Down's syndrome.

CONCLUSIONS

The present study confirms previous research findings of a high prevalence of behavioural and emotional difficulties amongst children with intellectual disability, and identifies a number of correlates of disorder which require further investigation.

Familial eosinophilic cellulitis, dysmorphic habitus, and mental retardation

BACKGROUND

Eosinophilic cellulitis is a polymorphous, chronic disease characterized by eosinophil infiltration and granulomatous inflammation.

OBJECTIVE

Our purpose was to describe the clinical, histologic, and immunohistologic findings in three family members who have had eosinophilic cellulitis since childhood associated with mental retardation and abnormal body habitus.

METHODS

Family members were evaluated. Multiple skin biopsy specimens were obtained and examined after hematoxylin-and-eosin staining, by immunofluorescence and by electron microscopy. Blood specimens were analyzed by immunoassays for eosinophil granule proteins and eosinophil active cytokines.

RESULTS

Three short-statured, mentally retarded family members with abnormal body habitus in at least two generations had recurrent eosinophilic cellulitis. Peripheral blood and bone marrow eosinophilia was present. Plasma eosinophil granule major basic protein and eosinophil-derived neurotoxin levels were elevated with normal plasma eosinophil cationic protein levels. Eosinophil survival in culture was increased by patients' plasma and was blocked with monoclonal interleukin-5 antibody. The level of plasma interleukin-5 was elevated. Lesional skin biopsy specimens showed massive staining for three eosinophil granule proteins. Electron microscopy showed eosinophil disruption.

CONCLUSION

Eosinophilic cellulitis, mental retardation, and abnormal body habitus were likely inherited as a dominant syndrome in this family in which eosinophil involvement was striking.

Reading against the lines: resisting foreclosure in therapy discourse

In this article, it is noted that poststructural ideas can be useful tools in fostering reflexivity and creativity for clinicians. By examining the process of meaning construction, clinicians can detach from repetitive interpretations of therapy discourse that lead to conversational closure. Four strategies for guiding a reading of family therapy interaction are presented: incitement to discourse, deconstruction, normativity, and the cultural grid of intelligibility. These strategies are used to describe examples of marital therapy discourse. By learning to read therapy as discourse, clinicians may critically examine how meaning is constructed and use that awareness to foster therapeutic conversations.

Is routine drainage of pelvic anastomosis necessary?

The routine use of drains for pelvic anastomosis is controversial. This study was undertaken to determine whether drainage alters leak rate, aids in diagnosing a leak, and/or prevents the need for laparotomy when a leak occurs. Records of 156 consecutive patients who underwent elective resection and pelvic anastomosis for cancer from 1986 to 1994 were retrospectively reviewed. The patients were stratified into two parent groups, I and II. One hundred and eleven Group I patients who routinely had Jackson-Pratt 10-mm drains inserted were subdivided into subgroup I-A (n = 24) with proximal intraoperative diversion and subgroup I-B (n = 87), without diversion. Forty-five Group II patients routinely did not have drains inserted. They were also subdivided, into II-A (n = 3) and II-B (n = 42), i.e., with and without simultaneous diversion, respectively. The overall leak rate was 5.1 per cent (8/156). Subgroups I-A and II-A had leak rates of 8.33 per cent (2/24) and 0 per cent (0/3), respectively. The leak rates were 4.6 per cent (4/87) in subgroup I-B and 4.8 per cent (2/42) in subgroup II-B, with no significant difference (P > 0.05). Also, no significant difference was noted when the overall leak rate for diverted cases was compared with nondiverted ones. Of the four leaks in I-B, three occurred after the drains were removed; two of these required laparotomy, drainage, and diversion. The fourth occurred with the drain in place, but failed to demonstrate feces or pus in the drainage fluid or prevent the need for laparotomy. The presence of a drain did not affect the leak rate (P > 0.10). Drain contents did not aid in diagnosing anastomotic dehiscence. Routine prophylactic use of Jackson-Pratt drains seems unjustified because leaks either occurred after the drains were removed or failed to prevent the need for laparotomy.

Sweet's syndrome after splenic irradiation for chronic myelogenous leukemia

Sweet's syndrome is defined as acute febrile neutrophilic dermatosis. Characteristic features are fever; peripheral neutrophilia; and painful cutaneous nodules and plaques on the face, neck, trunk, and limbs. Biopsy specimens of these lesions show a mature neutrophilic infiltrate of the dermis. Vasculitis is absent. Sweet's syndrome is associated with malignancy in approximately 20% of reported cases. The pathogenesis is unknown. The authors describe Sweet's syndrome in a 39-year-old man 5 weeks after splenic irradiation for chronic myelogenous leukemia. Treatment with parenteral corticosteroids resulted in dramatic improvement of the patient's condition. The authors discuss the diagnosis of Sweet's syndrome and the fact that it is thought to be cytokine-induced.

Cadmium-binding proteins from a tunicate, Pyura stolonifera

The determination of cadmium levels in tissues of the tunicate Pyura stolonifera collected from uncontaminated sites revealed highest concentrations in the liver. After keeping P. stolonifera under laboratory conditions in Cd-containing water for 15 days, cadmium accumulated most markedly in liver tissue. Liver tissue of Cd-exposed specimens was used for the isolation of Cd-binding proteins. Five Cd-binding proteins, which differ in their chromatographic properties, could be purified. At least four of these Cd-binding proteins are heat stable and cysteine-rich. The N-terminal sequence (Met-Asp-Pro-Cys-Asn-Cys-Ala-Glu...) of at least two of these peptides resembles fish (plaice) metallothionein. Unlike vertebrate metallothioneins, P. stolonifera Cd-binding proteins are not N-terminally blocked by acetylation of methionine.

A method based on PCR for the construction of cDNA libraries and probes from small amounts of tissue

A PCR-based method is described for the production of cDNA libraries and total cDNA probes from a few milligrams of tissue. Using a model system, we show how a PCR library and PCR probes can be used to identify genes expressed at different levels in two tissues. Small amounts of tissue derived from two plants, one infected with arabis mosaic virus and the other uninfected, were used to make a library and probes. This library and the probes were used to identify viral genes expressed only in the infected plant.

Dietary survey of Hopi Native American elementary students

OBJECTIVE

The purpose of this study was to evaluate the diets of 96 Hopi fifth- and sixth-grade students on the Hopi reservation in Arizona.

DESIGN

Dietary food intakes were collected using a 3-day dietary record and were analyzed with a computer software program to obtain information on the intake of energy, protein, carbohydrate, total fat, saturated fat, cholesterol, fiber, 10 vitamins, and six minerals.

SETTING

The survey was conducted during the health class or homeroom period in the elementary schools located on the Hopi reservation in Arizona.

SUBJECTS

The survey population consisted of 96 fifth- and sixth-grade Hopi elementary students attending the five schools on the Hopi reservation.

MAIN OUTCOME

Before data collection we hypothesized the average diet of Hopi elementary students did not meet dietary recommendations (eg, Dietary Goals, Recommended Dietary Allowances (RDAs), and/or National Cancer Institute recommendations).

STATISTICS

The nutrient analyses and demographic data were analyzed for frequencies and percentages of responses. Descriptive and inferential statistics were calculated where appropriate.

RESULTS

Results of the analysis revealed a mean daily dietary intake of 2,123 kcal consisting of 35% fat (84 g), 48% carbohydrate (261 g; 38% from sugar), and 17% protein (89 g), with 27 g saturated fat, 442 mg cholesterol, 11 g fiber, and 2,477 mg sodium. At least 97% or 100% of the RDA was met for all analyzed vitamins and minerals except for vitamin D (146 IU; 37% RDA), calcium (874 mg; 82% RDA), and zinc (12 mg; 94% RDA).

CONCLUSIONS

Given the health problems relatively new to Native Americans, such as diabetes, obesity, liver cirrhosis, hypertension, fetal alcohol syndrome, and increasing rates of heart disease and cancer, dietary modification may benefit them in their adult life. Modifications to meet current recommended dietary goals would include reducing fat to below 30% of energy; cholesterol to less than 250 mg; sodium to lower levels but not below 500 mg/day; and decreasing refined sugars. Carbohydrates would be increased to at least 58% energy; fiber to 20 to 30 g; and vitamin D, calcium, and, possibly, zinc to RDA levels.

Exogenous lipoid pneumonia due to nasal application of petroleum jelly

We describe a patient who presented with a history of unexplained exertional dyspnea and pulmonary infiltrates. She was evaluated for interstitial lung disease, presumed to be idiopathic and underwent an open lung biopsy. The pathologic findings were compatible with exogenous lipoid pneumonia and her history revealed longstanding use of intranasal petroleum jelly (Vaseline) at bedtime.

Anterior resection for the treatment of rectal prolapse: a 20-year experience

Between 1971 and 1991, 41 patients underwent anterior resection for the treatment of complete rectal prolapse. Anterior resection was performed after full rectal mobilization to the levator ani muscles with reanastomosis (39 hand-sewn and two stapled) carried out to peritonealized distal rectum. The 41 patients comprised 35 women and six men with an average age of 56 years (range, 7-88 years). Postoperative follow-up averaged 6 years (range, 6 months to 18 years). Three patients (7%) suffered recurrent prolapse in 2, 2.5, and 5.5 years, respectively. Mortality was 0 per cent; morbidity was 15 per cent including three incisional herniae, two small bowel obstructions, and one stroke. No pelvic sepsis, abscess, or anastomotic dehiscence occurred. Anal incontinence was a preoperative finding in 21 patients (51%) with rectal prolapse. Nineteen of these patients (90%) noted either improvement or no change in postoperative continence. Anterior resection is a familiar, frequently performed operation that does not require a foreign body or rectal suspension. We believe this to be the procedure of choice for patients with complete rectal prolapse. Anterior resection withstands long-term scrutiny both in terms of recurrence rate and associated complications.

Day-night variation of airways status in sympathomimetic- and theophylline-treated asthma patients

Eleven diurnally active asthma patients having a history of nocturnal asthma and treated regularly with albuterol or metaproterenol alone or with twice-daily sustained-release theophylline were evaluated for day-night pattern in peak expiratory flow (PEF) and use of supplemental beta-agonist aerosol for relief of acute asthma. Overall, significant day-night variation was observed in the supplemental use of beta-agonist medication and in airway patency. The patients managed by albuterol or metaproterenol alone used supplemental beta-agonist medication significantly more between 4 AM and 8 AM and also 8 PM and midnight in comparison to 4 PM to 8 PM; this was not true for those treated with both theophylline and beta-agonist aerosol. In patients taking a beta-agonist bronchodilator, the 24-hour mean PEF was greater than in those who also took theophylline, but the day-night variation in PEF was comparable. Supplemental isoproterenol use was significantly correlated with circadian amplitude of the PEF rhythm, but not with the 24-hour mean PEF. The greater the day-night variation in PEF, the greater the reliance on a supplemental beta-agonist bronchodilator.

Differential induction of heme oxygenase in the hepatocarcinoma cell line (Hep3B) by environmental agents

In situ hybridization and Northern analysis of heme oxygenase (HO) mRNA was used to determine the induction and expression of HO by various environmental agents. Exposure of Hep3B cells to hemin (10 microM) for as little as 5 min resulted in significant production of HO transcripts and mRNA expression as seen by in situ hybridization. We followed the pattern of HO transcript accumulation by heme and results indicate that the peak of induction of HO by heme was reached between 10 and 20 minutes. Other metalloporphyrins were all effective in inducing HO mRNA after 1 h exposure. On the other hand, CoCl2 caused accumulation of HO mRNA at a later time than seen with the metalloporphyrins. However, lipopolysaccharide (LPS) gave a more immediate effect on HO induction which was somewhat similar to heme in its time course. Direct measurements of HO activity revealed that enzyme activity could be detected after about 20 min exposure to hemin, and this activity was inhibited by tin protoporphyrin (SnPP). The different pattern of HO mRNA induction by LPS as contrasted with CoCl2 suggests that LPS may act through a different translational factor, or stimulate free radical formation and the subsequent release of heme and induction of HO. These results indicate that heme causes accumulation of HO mRNA by a different mechanism than that of CoCl2. Finally, LPS shares a concomitant effect on induction of HO as an acute phase reactant type protein.

Modulation of neurally mediated airway microvascular leakage in guinea-pig airways by beta 2-adrenoceptor agonists

The effect of two beta 2-adrenoceptor agonists, salbutamol (100 micrograms/kg i.v.) and broxaterol (100 micrograms/kg i.v.), on airway microvascular leakage induced by vagal stimulation was studied in anaesthetised guinea pigs. Airway microvascular leakage was measured by Evans blue extravasation. Broxaterol, but not salbutamol, inhibited Evans blue dye extravasation at all airway levels, an effect prevented by pretreatment with propranolol (1 mg/kg). Neither of the beta 2-agonists had any effect on substance P-induced Evans blue dye extravasation. Broxaterol inhibits the prejunctional release of tachykinins from airway sensory nerves by stimulation of beta-receptors. The mechanism by which beta-adrenoceptor agonists prevent airway microvascular leakage deserves further study.

Developmental Changes in Ionic and Osmotic Regulation in the Dungeness Crab, Cancer magister

The ontogeny of osmoregulation and specific ion regulation was studied in the megalopa, 1st instar juvenile, 5th instar juvenile and adult of Cancer magister. Hemolymph Na+, Cl-, K+, Mg++, and Ca++ concentrations and osmolality were measured after 8-h exposure to 100%, 75%, and 50% seawater at 10°C and 20°C. The ability to hyperosmotically regulate is present in the megalopa, and ontogenic changes occur in both ionic and osmotic regulation. First instar juvenile crabs, which are exposed to the greatest extremes of salinity and temperature in the field, are less able to osmoregulate than are the other three stages examined. Changes in Na+, Cl-, and K+ concentrations parallel total osmolality in all four stages. Hemolymph Mg++ concentrations in megalopa and juveniles acclimated to 100% seawater are more than twice that of the concentration in the adult; after 8 h in 50% seawater, the megalopa and juvenile Mg++ concentrations decrease to the level of the strongly regulated adult Mg++ concentration. Ca++ is strongly regulated by megalopas and adult crabs exposed to reduced salinity compared to the two juvenile stages. Diminished predation pressure and high food availability are proximate factors that may outweigh short-term osmoregulatory stress encountered on the tideflats during development of the juvenile crab.

Body Mass Index and perceived weight status in young adults

Body Mass Index (BMI) was calculated from self-reported height and weight for 1,123 university students who returned a questionnaire mailed to a 10 percent random sample of the entire undergraduate population of a large midwestern university. Seventeen percent of the females and 20 percent of the males were determined to be in excess of normal BMI standards. However, significantly more women (40%) considered themselves overweight in comparison to men (24%). Also, significantly more women (53%) than men (20%) reported experiencing discomfort due to excessive weight. Inaccurate perceptions of body image are common among individuals with eating disorders. There is a higher incidence of eating disorders among college-age women than among their male peers. A distorted body image as reflected by perceived overweight may serve as a marker for individuals at risk for eating disorders.

Evaluating the patient with a difficult airway for anesthesia

Patients with difficult airways present a challenge when they must undergo anesthesia. This article examines the problems inherent in evaluating patients with difficult airways for surgery. The authors believe that these patients are best evaluated in a Difficult Airway Clinic. The structure and organization of such clinics are examined.

Actigraphy: a means of assessing circadian patterns in human activity

Twenty-three diurnally active (0705-2333), healthy persons between 22 and 54 years of age and without history of sleep abnormality were monitored continuously for 120 consecutive hr (five days) by wrist actigraphy. Circadian rhythms of high amplitude were detected by cosinor analysis for each participant and for the groups of 10 males and 13 females with the average span of heightened activity timed between approximately 1330 and 1605. The circadian peak-trough difference in wrist movement was marked, equalling approximately 75% of the 24-hr mean level. In 19 of 23 participants, the 24-hr mean of wrist activity varied between 140-180 movements/min, with four persons exhibiting lesser means of 110-140 movements/min. With respect to the daytime span of activity, the mean wrist movement of individual participants ranged from 155-265 movements/min, with the majority (20/23) varying between 185-245 movements/min. During nocturnal sleep the mean wrist activity level was quite low, varying between individuals from 5 to 25 movements/min for 21 of 23 persons. Wrist actigraphy proved to be well-accepted and was a most reliable means of monitoring aspects of body movement during activity and sleep in ambulatory persons adhering to usual life habits and pursuits.

Tropospheric lifetimes of halogenated anaesthetics

Concern has been expressed over the use of the halogenated anaesthetics halothane (CF3CClBrH), enflurane (CF2HOCF2CFClH) and isoflurane (CF2HOCHClCF3) because of their potential for stratospheric ozone destruction. Halogenated species also contribute to global warming. The significance of the anaesthetics in stratospheric ozone loss or in 'greenhouse' heating depends on their atmospheric lifetimes. Because reaction with hydroxyl (OH) radicals is likely to be the main homogeneous sink for these species in the troposphere, we have measured absolute rates of reaction with OH. Comparison with a one-dimensional model indicates that the lifetimes of halothane, enflurane and isoflurane with respect to this reaction are 2, 6 and 5 years, respectively. Thus the small production of the anaesthetics is not offset by anomalously long atmospheric lifetimes to give a large atmospheric burden of the compounds. The anaesthetics will contribute at most a fraction of approximately 5 x 10(-4) to the total atmospheric content of chlorine-containing species.

Permeability of apical barriers

The purpose of this work was to measure the permeability (hydraulic conductance) of root canal apical barriers in vitro. In 30 extracted teeth, the pulp tissue was removed and the apical opening standardized and enlarged using endodontic files. One-millimeter thick barriers of either autogenous dentin chips, calcium hydroxide powder, or durapatite particles were placed just inside the apical opening. The prepared teeth were mounted in a special chamber, fluid pressure applied, and the resultant flow measured. The permeability of dentin chip barriers in 10 additional teeth with nonstandardized apical openings was measured also. The standardized canals with the autogenous dentin chip barriers had a mean permeability of 0.0010 microliter/s/psi at 20 psi applied pressure. Teeth with calcium hydroxide barriers averaged 0.0012 microliter/s/psi. The durapatite particle barriers were much more permeable and averaged 0.0220 microliter/s/psi. It was concluded that this technique is useful in evaluating the effectiveness of apical barrier materials. For the materials tested, autogenous dentin chips and calcium hydroxide barriers have significantly lower permeability than durapatite barriers (p = 0.05).

Histopathology of the internal anal sphincter in chronic anal fissure

A prospective study of 18 consecutive patients undergoing unilateral, partial-thickness, distal, internal sphincterotomy for the treatment of chronic anal fissure was performed. Biopsies were taken from the base of the fissure and from the lateral muscle before division. Normal specimens were taken from the internal anal sphincter of patients undergoing abdominoperineal resection. Specimens confirmed the presence of fibrosis throughout the internal anal sphincter in patients with anal fissures, but none in controls.