An AI-empowered indoor digital contact tracing system for COVID-19 outbreaks in residential care homes

An AI-empowered indoor digital contact-tracing system was developed using a centralized architecture and advanced low-energy Bluetooth technologies for indoor positioning, with careful preservation of privacy and data security. We analyzed the contact pattern data from two RCHs and investigated a COVID-19 outbreak in one study site. To evaluate the effectiveness of the system in containing outbreaks with minimal contacts under quarantine, a simulation study was conducted to compare the impact of different quarantine strategies on outbreak containment within RCHs. The significant difference in contact hours between weekdays and weekends was observed for some pairs of RCH residents and staff during the two-week data collection period. No significant difference between secondary cases and uninfected contacts was observed in a COVID-19 outbreak in terms of their demographics and contact patterns. Simulation results based on the collected contact data indicated that a threshold of accumulative contact hours one or two days prior to diagnosis of the index case could dramatically increase the efficiency of outbreak containment within RCHs by targeted isolation of the close contacts. This study demonstrated the feasibility and efficiency of employing an AI-empowered system in indoor digital contact tracing of outbreaks in RCHs in the post-pandemic era.

COVID-19 and cardiovascular manifestations

OBJECTIVE

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, a viral outbreak that started in December 2019, eventually lead to a worldwide pandemic. COVID-19 usually presents with flu-like symptoms, such as headaches, dry cough, fever, fatigue, myalgia, shortness of breath, diarrhea and loss of smell or taste. However, it can also have major effects on the cardiovascular system. Based on the available relevant literature, we aimed to elaborate the possible mechanisms influencing cardiovascular damage, myocardial injury and thromboembolic disease process in particular.

MATERIALS AND METHODS

After considering our inclusion and exclusion criteria, the systematic review included 8 studies in total.

RESULTS

In general, underlying cardiovascular diseases were associated with poorer clinical outcomes. This may be due to immunological dysregulation. The disease outcomes were also positively correlated with the severity of the disease, especially with myocardial injury. Thus, cardiac biomarkers, such as Troponin T, CK-MB and myoglobin could be utilized in prediction algorithms for deciphering the clinical outcome in COVID-19 patients.

CONCLUSIONS

Venous thromboembolisms were commonly encountered complications despite the administration of thromboprophylaxis, and they mostly presented as pulmonary embolisms, warranting the need for relevant investigations in hemodynamically unstable patients. However, more studies need to be conducted to better understand the mechanisms at play and the ensuing complications, to better treat COVID-19 patients.

Study protocol for 'the effects of multimodal training of cognitive and/or physical functions on cognition and physical fitness of older adults: a cluster randomized controlled trial'

Background

The elderly population worldwide is increasing exponentially which will be associated with more people suffering from cognition and fitness declines. The well-established benefits of exercise training for the elderly’s cognitive and physical functioning have been observed. However, the amalgamated effect of combining cognitive and physical exercises on the older adults’ cognitive functions, physical fitness, or psycho-related health remains unclear. Thus, this study protocol was planned to conduct different combinations of cognitive and/or physical training interventions to community-dwelling older adults and expected to see the multifaceted effects of the varied combination of training on their health.

Methods

This study is a cluster randomized controlled trial (CRCT). A total of 285 older adults (age ≥ 60) from twenty elderly centres as clusters will be randomly selected and assigned to intervention groups (IGs, n = 16) or control groups (CGs, n = 4). Each IG will be randomly assigned to one of the four combinations of three training modes that include cognitive (A), physical (B), and combined cognitive and physical training (CCPT, i.e. C), namely Mixed ABC, A + B, C + A, B + C. The intervention will last for 4 months in which the training is conducted for 16 sessions, 2 sessions per week, and 60 min per session. Four repeated assessments (pre-test, two post-training tests after 2 months and 4 months, and a follow-up test) will be conducted. The CG will only receive the four repeated assessments but no intervention. The outcome measures include cognitive tests (tests of execution, memory, and psych-social status), physical fitness, and dynamic balance tests.

Discussion

This study will provide substantial evidence that the integrated format of cognitive and physical exercises training will have higher cognition and fitness impact than the single training modes, and all these mixed modalities will have greater positive outcomes than the control condition. If the effectiveness is proven, the intervention can be further explored and extended to the nation so that many more elderly would be benefited.

Trial registration

The trial has been registered in the ClinicalTrials.gov in U.S. NIH (ID: NCT04727450, date: January 27, 2021).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03031-5.

Comparison of the molecular properties of retinitis pigmentosa P23H and N15S amino acid replacements in rhodopsin

Mutations in the RHO gene encoding for the visual pigment protein, rhodopsin, are among the most common cause of autosomal dominant retinitis pigmentosa (ADRP). Previous studies of ADRP mutations in different domains of rhodopsin have indicated that changes that lead to more instability in rhodopsin structure are responsible for more severe disease in patients. Here, we further test this hypothesis by comparing side-by-side and therefore quantitatively two RHO mutations, N15S and P23H, both located in the N-terminal intradiscal domain. The in vitro biochemical properties of these two rhodopsin proteins, expressed in stably transfected tetracycline-inducible HEK293S cells, their UV-visible absorption, their Fourier transform infrared, circular dichroism and Metarhodopsin II fluorescence spectroscopy properties were characterized. As compared to the severely impaired P23H molecular function, N15S is only slightly defective in structure and stability. We propose that the molecular basis for these structural differences lies in the greater distance of the N15 residue as compared to P23 with respect to the predicted rhodopsin folding core. As described previously for WT rhodopsin, addition of the cytoplasmic allosteric modulator chlorin e6 stabilizes especially the P23H protein, suggesting that chlorin e6 may be generally beneficial in the rescue of those ADRP rhodopsin proteins whose stability is affected by amino acid replacement.

Keratin 6a reorganization for ubiquitin-proteasomal processing is a direct antimicrobial response

Chan et al. show that epithelial cells respond to bacterial components in the environment by releasing subunits of the keratin 6a (K6a) filament network to the cytosol for degradation by the ubiquitin–proteasome system. This generates antimicrobial peptides from K6a that are important for innate defense of the mucosal surface.

Skin and mucosal epithelia deploy antimicrobial peptides (AMPs) to eliminate harmful microbes. We reported that the intermediate filament keratin 6a (K6a) is constitutively processed into antimicrobial fragments in corneal epithelial cells. In this study, we show that K6a network remodeling is a host defense response that directly up-regulates production of keratin-derived AMPs (KAMPs) by the ubiquitin–proteasome system (UPS). Bacterial ligands trigger K6a phosphorylation at S19, S22, S37, and S60, leading to network disassembly. Mutagenic analysis of K6a confirmed that the site-specific phosphorylation augmented its solubility. K6a in the cytosol is ubiquitinated by cullin-RING E3 ligases for subsequent proteasomal processing. Without an appreciable increase in K6a gene expression and proteasome activity, a higher level of cytosolic K6a results in enhanced KAMP production. Although proteasome-mediated proteolysis is known to produce antigenic peptides in adaptive immunity, our findings demonstrate its new role in producing AMPs for innate immune defense. Manipulating K6a phosphorylation or UPS activity may provide opportunities to harness the innate immunity of epithelia against infection.

Prospective Memory Performance in Persons With Schizophrenia and Bipolar Disorder and Healthy Persons

PURPOSE

There is a paucity of studies comparing prospective memory (PM) impairment between persons with schizophrenia and bipolar disorder. The aim of this study was to directly compare PM performances of these two groups and healthy controls.

DESIGN AND METHODS

A total of 44 persons with schizophrenia and 76 with bipolar disorder, and 44 healthy controls formed the study sample.

FINDINGS

Patients were found to be impaired in PM relative to controls and the two patient groups showed similar level of PM performance after controlling confounding sociodemographic and clinical variables.

PRACTICE IMPLICATIONS

The findings add to the evidence concerning the neurocognitive similarity between cohorts of schizophrenia and bipolar disorder with respect to PM. Rehabilitative effort in PM remedies for both patient groups is warranted.

Longitudinal changes in prospective memory and their clinical correlates at 1-year follow-up in first-episode schizophrenia

This study aimed to investigate prospective memory (PM) and the association with clinical factors at 1-year follow-up in first-episode schizophrenia (FES). Thirty-two FES patients recruited from a university-affiliated psychiatric hospital in Beijing and 17 healthy community controls (HCs) were included. Time- and event-based PM (TBPM and EBPM) performances were measured with the Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) at baseline and at one-year follow-up. A number of other neurocognitive tests were also administered. Remission was determined at the endpoint according to the PANSS score ≤ 3 for selected items. Repeated measures analysis of variance revealed a significant interaction between time (baseline vs. endpoint) and group (FES vs. HCs) for EBPM (F(1, 44) = 8.8, p = 0.005) and for all neurocognitive components. Paired samples t-tests showed significant improvement in EBPM in FES (13.1±3.7 vs. 10.3±4.8; t = 3.065, p = 0.004), compared to HCs (15.7±3.6 vs. 16.5±2.3; t = -1.248, p = 0.230). A remission rate of 59.4% was found in the FES group. Analysis of covariance revealed that remitters performed significantly better on EBPM (14.9±2.6 vs. 10.4±3.6; F(1, 25) = 12.2, p = 0.002) than non-remitters at study endpoint. The association between EBPM and 12-month clinical improvement in FES suggests that EBPM may be a potential neurocognitive marker for the effectiveness of standard pharmacotherapy. Furthermore, the findings also imply that PM may not be strictly a trait-related endophenotype as indicated in previous studies.

Prospective memory performance in non-psychotic first-degree relatives of patients with schizophrenia: a controlled study

Objective

We aimed at investigating prospective memory and its socio-demographic and neurocognitive correlates in non-psychotic, first-degree relatives (FDRs) of patients with schizophrenia compared to patients with first episode schizophrenia (FES), and healthy controls (HCs).

Methods

Forty-seven FES patients, 50 non-psychotic FDRs (23 offspring and 27 siblings) of patients with chronic schizophrenia (unrelated to the FES group) and 51 HCs were studied. The Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) was used to measure time-based prospective memory (TBPM) and event-based prospective memory (EBPM) performance. Other cognitive functions (involving respective memory and executive functions) were evaluated with standardized tests.

Results

After controlling for basic demographic characteristics including age, gender and educational level, there was a significant difference between FDRs, FES and HCs with respect to both TBPM (F_(2,142) = 10.4, p<0.001) and EBPM (F_(2,142) = 10.8, p<0.001). Multiple linear regression analyses revealed that lower scores of the Hopkins Verbal Learning Test-Revised (HVLT-R) and the STROOP Word-Color Test (SWCT) contributed to TBPM impairment, while lower educational level and higher scores of the Color Trails Test-2 (CTT-2) contributed to EBPM deficit in FDRs.

Conclusions

FDRs share similar but attenuated prospective memory impairments with schizophrenia patients, suggesting that prospective memory deficits may represent an endophenotype of schizophrenia.

Prospective memory predicts the level of community living skills in schizophrenia

Schizophrenia patients are known to have prospective memory (PM) deficits. There is no robust evidence showing that PM deficits have a major impact on community living skills in schizophrenia. The aim of this study was to examine the association between PM and community living skills in schizophrenia. Forty-four individuals with schizophrenia formed the study sample. Participants׳ psychopathology, prospective and retrospective memory, level of intelligence, and community living skills were measured with standardized instruments. In bivariate analyses, community living skills overall but not self-care correlated with PM total and subscales scores. In multivariate analyses, event-based PM was more predictive than time-based PM of the level of community living skills. In conclusion, PM has a significant impact on community living skills in schizophrenia and attention should be paid to this type of memory disturbance in rehabilitation of schizophrenia.

Predictive value of prospective memory for remission in first-episode schizophrenia

PURPOSE

The study examined the rate of remission in individuals experiencing a first episode of schizophrenia (FES) in China and explored predictors of remission in the acute phase of the illness.

DESIGN AND METHODS

Fifty-five FES patients were randomly treated with risperidone, olanzapine, or aripiprazole at therapeutic doses for 8 weeks, and their clinical profiles and cognition were assessed using standardized assessment instruments at entry and the end of the study.

FINDINGS

Of the 55 patients, 30 (54.5%) remitted by the end of the 8-week study. In univariate analyses, shorter duration of untreated psychosis, higher scores on both the time-based prospective memory (TBPM) and event-based prospective memory tasks and the Hopkins Verbal Learning Test-revised, and less severe negative symptoms were significantly associated with remission. In stepwise multiple logistic regression analyses, only higher scores on the TBPM significantly predicted remission. Individuals having higher scores reflecting better TBPM at baseline were more likely to achieve remission after 8 weeks of optimized antipsychotic treatment.

PRACTICE IMPLICATIONS

TPBM may be useful in helping clinicians identify those FES patients most likely to achieve a favorable treatment response.

Assessment of prospective memory in schizophrenia using the Chinese version of the Cambridge Prospective Memory Test: a controlled study

INTRODUCTION

Data on the psychometric assessment of prospective memory (PM) are limited. The Cambridge Prospective Memory Test (CAMPROMPT) and its Chinese version (CAMPROMPT-C) have been applied to a variety of clinical conditions except for chronic schizophrenia. This controlled study explored the clinical utility of the CAMPROMPT-C in patients with schizophrenia by comparing their PM performance with that of normal controls.

METHODS

Forty-four schizophrenia patients and 44 normal controls formed the study sample. Sociodemographic characteristics, PM, retrospective memory, and intelligence were measured in all subjects. Patients' psychopathology was rated with a standardized instrument.

RESULTS

Patients performed worse than normal controls on both the sum and subscale scores of the CAMPROMPT-C. Patients had comparable performances in PM subtypes. Bivariate analyses revealed that education level, intelligence, and retrospective memory were associated with PM functions.

DISCUSSION

The study supports the clinical utility of the CAMPROMPT-C in chronic schizophrenia and corroborated the significant relationship between PM and education, intelligence, and retrospective memory.

Evaluation of a virtual reality prospective memory task for use with individuals with severe traumatic brain injury

The current study aimed to evaluate the sensitivity, convergent validity and ecological validity of a newly developed virtual reality prospective memory (PM) task (i.e., the Virtual Reality Shopping Task; VRST) for use with individuals with traumatic brain injury (TBI). Thirty individuals with severe TBI and 24 uninjured adults matched on age, gender and education level were administered the VRST, a lexical decision PM task (LDPMT), an index of task-friendliness and a cognitive assessment battery. Significant others rated disruptions in the TBI participants' occupational activities, interpersonal relationships and independent living skills. The performance of the TBI group was significantly poorer than that of controls on event-based PM as measured by the LDPMT, and on time- and event-based PM as measured by the VRST. Performance on the VRST significantly predicted significant others' ratings of patients' occupational activities and independent living skills. The VRST was rated as significantly more reflective of an everyday activity, interesting and was afforded a higher recommendation than the LDPMT. For the TBI group, event and total PM performance on the VRST significantly correlated with performance on measures of mental flexibility and verbal fluency, and total PM performance correlated with verbal memory. These results provide preliminary but promising evidence of the sensitivity, as well as the convergent and ecological validity of the VRST.

Quality of life of patients with euthymic bipolar disorder and its associations with demographic and clinical characteristics, psychopathology, and cognitive deficits

PURPOSE

Little is known about quality of life (QOL) in Chinese patients with bipolar disorder (BD) in remission (euthymia). This study examined the QOL of such a cohort of BD patients and its demographic, clinical, and cognitive correlates.

DESIGN AND METHODS

Forty-seven euthymic BD patients and 47 matched healthy controls formed the study sample. Socio-demographic characteristics, prospective memory, retrospective memory, intelligence quotient, and executive functioning were measured in all participants together with patients’ psychopathology ratings.

FINDINGS

Multivariate analyses revealed that compared to controls, euthymic BD patients had significantly lower satisfaction with physical QOL domain. Only subthreshold depressive symptoms independently contributed to reduced satisfaction with physical and environmental QOL domains, whereas no variable predicted its psychological and social domains.

PRACTICE IMPLICATIONS

Contrary to findings from Western settings, demographic variables and cognitive deficits had no associations with any QOL domain in euthymic Chinese BD patients. Control of subthreshold depressive symptoms in euthymic BD patients might enhance their QOL.

Prospective memory impairment and its implications for community living skills in bipolar disorder

OBJECTIVE

Prospective memory (PM) refers to the ability to undertake intended actions in the future. The functional significance of PM in bipolar disorder (BD) has not yet been investigated. This study examined PM impairment and its role in community living skills in clinically stable individuals with BD.

METHODS

Seventy-six individuals with BD and 44 healthy individuals were assessed with the Chinese version of the Cambridge Prospective Memory Test. Socio-demographic characteristics, retrospective memory (RM; the ability to recall or recognize past information), and intelligence were also measured in all participants. The clinical condition and community living skills of patients with BD were rated independently with standardized instruments.

RESULTS

Patients with BD showed PM impairment and their PM total scores independently predicted the level of community living skills in regression analyses. In follow-up analyses, the contribution was found to be accounted for by the time-based PM scores.

CONCLUSIONS

Given the expanding body of research on the utility of PM in predicting functioning, these findings further support the role of PM in community living skills in individuals with BD. The results suggest that PM training might be an integral part of clinical rehabilitation devised for individuals with BD.

Prospective memory deficits in euthymic bipolar disorder patients: a preliminary study

INTRODUCTION

Prospective memory refers to the ability to remember to do something in the future. To date, little is known about prospective memory deficits in bipolar disorder (BD) in remission (euthymia). This study examined the nature and correlates of prospective memory in these patients.

METHODS

Forty-seven euthymic BD patients and 47 matched healthy controls formed the study sample. Socio-demographic and basic clinical characteristics, prospective memory (Cambridge Prospective Memory Test [CAMPROMPT]), retrospective memory (immediate Logical Memory subtests of the Wechsler Memory Scales-Revised [WMS-R]), IQ (Raven's Progressive Matrices) and executive functioning (Wisconsin Card Sorting Test) were measured in all participants; patients' symptoms were rated with the 17-item Hamilton Depression Rating Scale and the 11-item Young Mania Rating Scale.

RESULTS

Patients performed significantly worse on time-based prospective memory compared to controls. Multivariate analyses revealed that patients' lower score on Raven's Progressive Matrices significantly contributed to poor performance on time-based prospective memory, whereas lower scores on WMS-R Logical Memory subtest contributed to poor performance on event-based prospective memory; in controls, lower education level and older age significantly contributed to poor performance on time-based and event-based prospective memory, respectively.

DISCUSSION

Prospective memory deficits persist in remitted BD patients suggesting that prospective memory impairment constitutes a trait deficit in BD.

Characteristics and clinical correlates of prospective memory performance in first-episode schizophrenia

OBJECTIVE

The aim of this study was to examine prospective memory (PM) and its socio-demographic, clinical, and neurocognitive correlates in first episode schizophrenia (FES).

METHODS

Fifty-one FES patients and 42 healthy controls formed the study sample. Time- and event-based PM (TBPM and EBPM) performance were measured with the Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT). A battery of neuropsychological tests was also administered. Patients' clinical symptoms were evaluated with the Positive and Negative Symptom Scale (PANSS).

RESULTS

Patients performed significantly worse in both TBPM (8.7 ± 5.3 vs. 14.8 ± 3.5) and EBPM (11.3 ± 4.7 vs. 15.7 ± 2.7) than the controls. After controlling for age, gender, education level and neurocognitive test score, the difference in performance on the two types of PM tasks between patients and controls was no longer present. In multiple linear regression analyses, longer duration of untreated psychosis (DUP), lower scores of the Hopkins Verbal Learning Test-Revised (HVLT-R) and the categories completed of the Wisconsin Card Sorting Test (WCST-CC) and higher score of the Color Trails Test-2 (CTT-2) contributed to poorer TBPM performance, while lower score of HVLT-R, higher score of the perseverative errors of the Wisconsin Card Sorting Test (WCST-PE) and longer DUP contributed to worse performance on EBPM.

CONCLUSIONS

Both subtypes of PM are impaired in first-episode schizophrenia suggesting that PM deficits are an integral part of the cognitive dysfunction in the disease process.

Prospective memory deficits in patients with bipolar disorder: a preliminary study

Prospective memory (PM) is the ability to remember to do something in the future without explicit prompts. To date, little has been known about PM deficits in bipolar disorder (BD). This study examined the nature and correlates of PM in patients with BD. Forty clinically stable BD patients and 40 matched healthy controls formed the study sample. Socio-demographic characteristics, PM, psychosocial functioning, retrospective memory (RM), and IQ were measured in all participants, whereas clinical condition was measured in patients with standardized assessment instruments. Patients performed significantly more poorly on the time-based PM task than controls (10.6 ± 5.0 vs. 14.6 ± 3.0, p < .001). In correlation analyses, older age, lower education, more severe depressive and manic symptoms, poor psychosocial functioning, poor RM, and lower scores in IQ were significantly associated with poor performance in the time-based PM task, whereas poor RM and lower scores in IQ associated with poorer performance in the event-based PM task in patients. In multivariate analyses, severity of depression and older age significantly contributed to poor performance in the time-based PM task, whereas poor RM contributed to poor performance in the event-based PM task in patients. The time-based PM is impaired in BD patients. Depressive symptoms, age, and RM were determinants of certain aspects of impaired PM performance in BD patients.

Systematic prediction of human membrane receptor interactions

Membrane receptor-activated signal transduction pathways are integral to cellular functions and disease mechanisms in humans. Identification of the full set of proteins interacting with membrane receptors by high-throughput experimental means is difficult because methods to directly identify protein interactions are largely not applicable to membrane proteins. Unlike prior approaches that attempted to predict the global human interactome, we used a computational strategy that only focused on discovering the interacting partners of human membrane receptors leading to improved results for these proteins. We predict specific interactions based on statistical integration of biological data containing highly informative direct and indirect evidences together with feedback from experts. The predicted membrane receptor interactome provides a system-wide view, and generates new biological hypotheses regarding interactions between membrane receptors and other proteins. We have experimentally validated a number of these interactions. The results suggest that a framework of systematically integrating computational predictions, global analyses, biological experimentation and expert feedback is a feasible strategy to study the human membrane receptor interactome.

Constitutive activation of signal transducer and activator of transcription 5 contributes to tumor growth, epithelial-mesenchymal transition, and resistance to epidermal growth factor receptor targeting

PURPOSE

Signal transducer and activator of transcription 5 (STAT5) is activated in squamous cell carcinoma of the head and neck (SCCHN), where targeting of STAT5 inhibits tumor growth in vitro and in vivo. The role of STAT5 activation in carcinogenesis, tumor progression, and response to therapy remains incompletely understood. In this study, we investigated the effects of STAT5 activation on squamous epithelial carcinogenesis and response to therapy.

EXPERIMENTAL DESIGN

The functional consequences of STAT5 activation in squamous epithelial carcinogenesis were examined using cells derived from normal (Het-1A) and transformed mucosal epithelial cells engineered to express constitutive-active mutants of STAT5.

RESULTS

The growth rate of stable clones derived from both normal and transformed squamous epithelial cells expressing the constitutive-active STAT5 was increased. In SCCHN xenografts, tumor volumes were increased in constitutive-active STAT5 mutant cells compared with vector-transfected controls. Constitutive activation of STAT5 significantly increased cell migration and invasion through Matrigel, as well as the transforming efficiency of SCCHN cells in vitro, as assessed by soft agar assays. The constitutive-active STAT5 clones derived from SCCHN cells showed changes consistent with an epithelial-mesenchymal transition including decreased expression of E-cadherin and increased vimentin in comparison with control transfectants. In these cells, STAT5 activation was associated with resistance to cisplatin-mediated apoptosis and growth inhibition induced by the epidermal growth factor receptor tyrosine kinase inhibitor, erlotinib.

CONCLUSIONS

These results suggest that constitutive STAT5 signaling enhances tumor growth, invasion, and epithelial-to-mesenchymal transition in squamous epithelial carcinogenesis and may contribute to resistance to epidermal growth factor receptor tyrosine kinase inhibitor and chemotherapy.

Retinitis pigmentosa associated with rhodopsin mutations: Correlation between phenotypic variability and molecular effects

Similar retinitis pigmentosa (RP) phenotypes can result from mutations affecting different rhodopsin regions, and distinct amino acid substitutions can cause different RP severity and progression rates. Specifically, both the R135L and R135W mutations (cytoplasmic end of H3) result in diffuse, severe disease (class A), but R135W causes more severe and more rapidly progressive RP than R135L. The P180A and G188R mutations (second intradiscal loop) exhibit a mild phenotype with regional variability (class B1) and diffuse disease of moderate severity (class B2), respectively. Computational and in vitro studies of these mutants provide molecular insights into this phenotypic variability.

Solution structure of the C-terminal domain of the ciliary neurotrophic factor (CNTF) receptor and ligand free associations among components of the CNTF receptor complex

The functional receptor complex of ciliary neurotrophic factor (CNTF), a member of the gp130 family of cytokines, is composed of CNTF, the CNTF receptor alpha (CNTFR), gp130, and the leukemia inhibitory factor receptor (LIFR). However, the nature of the receptor-mediated interactions in this complex has not yet been resolved. To address this issue we have determined the solution structure of the C-terminal or BC domain of CNTFR and studied the interactions of CNTFR with LIFR and gp130. We reported previously that the membrane distal cytokine-binding domain (CBD1) of LIFR could interact in vitro with soluble CNTFR (sCNTFR) in the absence of CNTF. Here we show that the CBD of human gp130 can also bind in vitro to sCNTFR in the absence of CNTF. In addition, the gp130 CBD could compete with the LIFR CBD1 for the binding of sCNTFR. Substitution of residues in the gp130 CBD, the LIFR CBD1, and the CNTFR BC domain that are expected to be involved in receptor-receptor interactions significantly reduced their interactions. An NMR chemical shift perturbation study of the interaction between the BC domains of CNTFR and gp130 further mapped the interaction surface. These data suggest that both the gp130 CBD and the LIFR CBD1 interact with CNTFR in a similar way and provide insights into the nature of the CNTF receptor complex.

Interaction between calcium-free calmodulin and IQ motif of neurogranin studied by nuclear magnetic resonance spectroscopy

The interaction of Ca(2+)-free calmodulin (apoCaM) with the IQ motif corresponding to the calmodulin-binding domain of neurogranin has been studied by nuclear magnetic resonance (NMR) methods. The NMR spectra of uncomplexed apoCaM and apoCaM in complex with the IQ motif recorded at 750 MHz were studied and the backbone assignments of the protein in both forms were obtained by triple-resonance multidimensional NMR experiments. Chemical shift perturbations were used to map the binding surfaces. Only a single set of resonances was observed throughout the titration, indicating that the binding interaction is under fast exchange. Analysis of chemical shift changes indicates that (a) the main interaction and conformational changes occur in the C-terminal domain of calmodulin and (b) linker-1 (residues 40-44) between EF-1 and EF-2, linker-3 (residues 112-117) between EF-3 and EF-4, and the end of the alpha-helix H (residues 145-148) may be involved in the binding process. The dissociation constant (K(d)), estimated by fitting the chemical shift changes against the IQ peptide concentration, ranged from about 1.2 x 10(-5) to 8.8 x 10(-5) M. This result demonstrates that the interaction falls into the weak binding regime.

Computer simulations of the electric interactions between the phospholipid head-groups and ionic admixtures in the membrane surface

Some phospholipids (e.g. lecithin) form a system of electric dipoles on the membrane surface layer. In the case of lecithin the positive dipole charge is located on the choline and the negative one on the phosphoric molecule group. These dipoles are arranged almost parallel to the membrane surface. Taking the dipole membrane structure as a base for further investigations, a computer model of the electrostatic interaction between the dipole system and the ionic admixture was investigated. The model presumes hexagonal centered or a rectangular flat geometry of the 121 dipoles distribution. The dipoles may rotate freely around round the motionless symmetry axis perpendicular to the system surface. The initial state is given by fixing the geometry of the dipole matrix and ionic admixture distribution. Subsequently this system underwent a computer simulation which consisted of a calculation of resultant force moments acting on each dipole caused by other dipoles and ions. These force moments lead the system to the equilibrium state (minimum of the binding energy). The minimum energy value of the dipoles system depends on concentration and charge of the admixtured ions. The results of repeated simulations indicate that the system achieve the least of all binding energy (the most stable equilibrium state) at 1.5% concentration of admixtured ions in case of ion charge equal to 1Q (where Q denotes arbitrary unit of ion charge) and at 2.5% concentration of admixtured ions in case of ion charge equal to 2Q. The calculated results are in a good agreement with the experimental.

3D H(aro)-NOESY-CH3NH and C(aro)-NOESY-CH3NH experiments for double labeled proteins

Precision in the determination of the 3D structures of proteins by NMR depends on obtaining an adequate number of NOE restraints. Ambiguity in the assignment of NOE cross peaks between aromatic and other protons is an impediment to high quality structure determination. Two pulse sequences, 3D H(aro)-NOESY-CH3NH and 3D C(aro)-NOESY-CH3NH, based on a modification of a technique for simultaneous detection of 13C-1H (of CH3) and 15N-1H correlations in one measurement, are proposed in the present work. These 3D experiments, which are optimized for resolution in the 13C and 15N dimensions, provide NOE information between aromatic protons and methyl or amide protons. CH2 moieties are filtered out and the CH groups in aromatic rings are selected, allowing their NOE cross peaks to be unambiguously assigned. Unambiguous NOEs connecting aromatic and methyl or amide protons will provide important restraints for protein structure calculations.

The use of autologous platelet-rich plasma (platelet gel) and autologous platelet-poor plasma (fibrin glue) in cosmetic surgery

The purpose of this study was to evaluate a new technique of harvesting and preparing autologous platelet gel and autologous fibrin glue (body glue) and to evaluate their effectiveness in stopping capillary bleeding in the surgical flaps of patients undergoing cosmetic surgery. A convenience sample of 20 patients ranging from 25 to 76 years of age undergoing cosmetic surgery involving the creation of a surgical flap were included in the study. The types of surgical procedures included face lifts, breast augmentations, breast reductions, and neck lifts. Platelet-poor and platelet-rich plasma were prepared during the procedure from autologous blood using a compact, tabletop, automated autologous platelet concentrate system (SmartPReP, Harvest Autologous Hemobiologics, Norwell, Mass.). The platelet-poor and platelet-rich plasma were combined with a thrombin-calcium chloride solution to produce autologous fibrin glue and autologous platelet gel, respectively. Capillary bed bleeding was present in all cases and effectively sealed within 3 minutes following the application of platelet gel and fibrin glue. The technique for making the solution and for evaluating its effectiveness in achieving and maintaining hemostasis during cosmetic surgical procedures is described. Autologous platelet gel and fibrin glue prepared by the automated concentrate system are compared with autotransfusor-prepared platelet gel and Tisseel (Baxter Healthcare Corp.), a commercially prepared fibrin sealant preparation.

Sensitivity enhancement of HCACO by using an HMQC magnetization transfer scheme

Previous theoretical calculations have demonstrated that the multiquantum relaxation rate of (1)H(alpha)-(13)C(alpha)(R(MQ)) is, on average, 1.3 +/- 0.4 or 1.7 +/- 0.6 times slower than the single-quantum relaxation rate of (13)C(alpha)(R(C)) for a sample with or without, respectively, amide protons. By taking advantage of this fact and by using the PEP sensitivity enhancement scheme, an HMQC version of the HCACO experiment has been developed. We demonstrate that this new experiment is 23 and 55% more sensitive than the original HSQC version of the HCACO experiment, at constant times of 7 and 27 ms, respectively, for a sample of the BC domain of the ciliary neurotrophic factor receptor protein dissolved in D(2)O at 20 degrees C.

The influence of permanent magnetic field therapy on wound healing in suction lipectomy patients: a double-blind study

The authors present their experience with the healing influence of permanent magnets on postoperative wounds. The responses of 20 patients who underwent suction lipectomy and postoperative negative magnetic field therapy were studied in a double-blind fashion. Magnets in the form of patches (10 patients) or sham magnet patches (10 patients) were placed over the operative region in each of the patients. Pain, edema, and discoloration (ecchymosis) were evaluated at 1, 2, 3, 4, 7, and 14 days postoperatively. Our results show that the treatment group had significant reductions in pain on postoperative days 1 through 7, in edema on days 1 through 4, and in discoloration on days 1 through 3 when compared with the control group. These results demonstrated that commercially available magnets have a positive influence on the postoperative healing process in suction lipectomy patients.

Community-based empowerment programme for families with a brain injured survivor: an outcome study

Rehabilitation of brain injured persons has been one of the challenges of the modern health care team. Brain injured persons' problems are termed complex and multiple, and may persist long after the acute management stage. Families caring for their brain-injured members are, however, ill prepared to face this long-term rehabilitation process. A previous study of an empowerment framework applicable among these Hong Kong Chinese families resulted in the development of a 52-item empowerment questionnaire with four interpretable factors (efficacy, knowledge, support and aspiration). This can also serve as a valid and reliable outcome measure of their empowerment efforts. As a follow-up of this development, an 8-week community-based empowerment programme was thus designed and implemented for a total of 50 family members in six repeated groups. Outcome indicators including empowerment questionnaire, psychological well-being, self-efficacy, subjective experience of the burdens in care-giving, and support systems were used to monitor changes in empowerment status during the periods of pre- and post-programme, and during the 3 month follow-up. The programmes were found to be effective in empowering family members in the four postulated empowering dimensions, and improving all other outcome measures. The follow-up studies reflect stability in empowerment, though there were no further improvement. From regression analysis, it was suggested that, for optimum empowerment to take place, important predictors included careers' education levels, age ranges and work status.

ESR study of the liposome membrane physical parameters in the heating-cooling cycles

Changes of dynamic and structural parameters of egg yolk lecithin (EYL) liposome membranes in the heating-cooling cycles have been studied using the ESR spin probe method. The investigations were conducted in the range of temperatures from -18 degrees C to +60 degrees C. It has been found that in the range of temperatures -15 degrees C to +45 degrees C in both the heating and the cooling run the spectroscopic parameters changed practically along the same curve (reversible changes). However, after exceeding this range of temperatures one of the parameters (partition coefficient of the spin probe 2,2,6,6--tetramethylpiperidine -1-oxyl; TEMPO) changed along a closed curve, showing the phenomenon of thermal hysteresis. In the heating process the TEMPO content in liposome membranes was smaller than this in the cooling process. We assume that during the heating, the lipid molecules of the outer liposome layers dissolve in the aqueous medium. In the cooling process they can aggregate and form new liposomes, what in turn increases the surface of liposome membranes, accessible for the TEMPO probe (active surface).

Bimodal effect of amphiphilic biocide concentrations on fluidity of lipid membranes

Using the spin label method (ESR) it has been shown that biologically active, amphiphilic compounds (quaternary ammonium salts (AS) containing polar heads with single and double positive charge caused, at low concentrations, decrease fluidity of liposome membranes formed with egg yolk lecithin (EYL). At higher concentrations an increase in fluidity was observed. With compounds having a single positive charge minimum fluidity of membrane structure occurs in the range of 1 to 3%, with compounds containing double positive charge-in the range of 4-6%. That effect does not depend on polar head size and length of alkyl chains of the AS used. Analysis of the electrostatic interaction between positive charges and dipole system suggest that at low ion concentrations the binding energy of the system increases, while it decreases at high concentrations. For the model presented, maximum of binding energy of the system occurs at 3% of positive monovalent ions and at 6% of positive divalent ions admixed.

A new addition to face lift surgery: the argon gas surgical unit

In the quest to improve the technique of performing face lift surgery, we have encountered a device, the argon gas surgical unit, that offers a number of advantages over current techniques. These advantages include significant reductions in the amount of both intraoperative and postoperative blood loss, depth of tissue damage, amount of postoperative swelling, and amount of postoperative pain. This paper describes our experience with the use of the argon gas surgical unit compared with conventional electrocautery in 30 patients undergoing face lift. On histologic examination of the skin specimens, there was a consistent decrease in the depth of tissue damage with the argon gas surgical unit. With regard to blood loss, as a whole there was a marked decrease in the argon gas surgical unit group. Additionally, there is a clinically significant decrease in postoperative swelling in the patients in whom the argon gas surgical unit was employed that contributes to improved wound healing and an overall improved postoperative course.

Stretching and tissue expansion for rhytidectomy: an improved approach

Intraoperative expansion of the skin of the face supplies additional tissue that permits closure of the face lift incision with minimal tension. This paper presents the findings in rhytidectomy patients over the last 3 years using both intraoperative stretching and intraoperative stretching combined with tissue expansion utilizing the Man face lift expander. Sixty-seven patients underwent rhytidectomy surgery, of whom 50 were treated with stretching techniques alone and 17 were treated with the combined stretching and expansion method. The patients' ages ranged from 28 to 78 years. Results indicate that the patients treated with combined stretching and expansion had significantly more skin removed. This new technique appears to offer significant clinical advantages over usual face lifts.

Neutral and acidic species of human intestinal mucin. Evidence for different core peptides

Highly purified human mucins from postmortem intestinal tissue were fractionated on anion exchange columns to generate separate neutral and acidic species. The neutral mucin (less than 1.0 mol % sialic acid) was the major species (greater than 80% by weight) and contained a higher molar proportion of fucose, galactose, and N-acetylglucosamine, and a lower proportion of sialic acid and N-acetylgalactosamine than the acidic species (greater than 10 mol % sialic acid). Amino acid analyses revealed a highly significant enrichment in serine, aspartate, and alanine in the neutral species and proline, threonine, and glycine in the acidic species. Thiol reduction of each species to remove their integral 118,000-dalton component did not alter the essential interspecies differences. Differences in threonine, proline, and serine also remained after removal of all "naked" or pronase-susceptible peptide regions from each species. These results indicate that neutral and acidic mucins contain glycopeptide segments exclusive of their 118,000-dalton and naked peptide components, which differ in amino acid composition. The key amino acid markers are similar to those observed for fuco- and sialoglycopeptides obtained after proteolytic digestion of human colonic mucin by Gold et al. (Gold, D.V., Schochat, D., and Miller, F. (1981) J. Biol. Chem. 256, 6354-6358). The oligosaccharide composition of small intestinal and colonic mucin may therefore depend upon transcriptional control of the synthesis of specific mucin peptides as well as the post-translational activity of glycosyltransferases. These findings may have significance for the quality and functions of mucus produced in a variety of pathological states.

Drug allergy: incidence in terms of age and some drug allergens

The authors studied the incidence of drug allergy in 3 groups of subjects. In the first group the incidence was established in terms of the subjects' age: 1.8% in children up to 14 years old (323 subjects), 5.8% in middle-aged subjects (389 subjects) and 2.9% in the elderly (243 subjects). In the second partly selected group, drug allergy was studied in patients admitted to the 3rd Medical Clinic--Craiova between 2 Jan. 1981 and 31 Dec. 1982; 103 of the 8,760 patients admitted presented allergic reactions, a relatively high incidence rate (1.01%) as compared to other published reports. The third group of previously selected cases consisted of 197 patients who had come to the allergology service with complaints of present or past sensitivity to drugs. The total number of patients was 336 selected or preselected from about 10,000 subjects, to which 17 patients with a diagnosis of "asthmatic triad" must be added. Drug allergy in terms of the drug used was dominated by penicillin, pyramidon-algocalmin, aspirin, iodine preparations, etc.; foremost among the clinical syndrome were the dermatologic syndromes types I, III and IV; syndromes of the "anaphylactic shock" type, "serum sickeness" bronchial asthma, angioneurotic oedema.