Non-binary gender, vulnerable populations and mental health during the COVID-19 pandemic: Data from the COVID-19 MEntal health inTernational for the general population (COMET-G) study

BACKGROUND

The COVID-19 pandemic has brought significant mental health challenges, particularly for vulnerable populations, including non-binary gender individuals. The COMET international study aimed to investigate specific risk factors for clinical depression or distress during the pandemic, also in these special populations.

METHODS

Chi-square tests were used for initial screening to select only those variables which would show an initial significance. Risk Ratios (RR) were calculated, and a Multiple Backward Stepwise Linear Regression Analysis (MBSLRA) was followed with those variables given significant results at screening and with the presence of distress or depression or the lack of both of them.

RESULTS

The most important risk factors for depression were female (RR = 1.59-5.49) and non-binary gender (RR = 1.56-7.41), unemployment (RR = 1.41-6.57), not working during lockdowns (RR = 1.43-5.79), bad general health (RR = 2.74-9.98), chronic somatic disorder (RR = 1.22-5.57), history of mental disorders (depression RR = 2.31-9.47; suicide attempt RR = 2.33-9.75; psychosis RR = 2.14-10.08; Bipolar disorder RR = 2.75-12.86), smoking status (RR = 1.15-5.31) and substance use (RR = 1.77-8.01). The risk factors for distress or depression that survived MBSLRA were younger age, being widowed, living alone, bad general health, being a carer, chronic somatic disorder, not working during lockdowns, being single, self-reported history of depression, bipolar disorder, self-harm, suicide attempts and of other mental disorders, smoking, alcohol, and substance use.

CONCLUSIONS

Targeted preventive interventions are crucial to safeguard the mental health of vulnerable groups, emphasizing the importance of diverse samples in future research.

LIMITATIONS

Online data collection may have resulted in the underrepresentation of certain population groups.

Somatic multicomorbidity and disability in patients with psychiatric disorders in comparison to the general population: a quasi-epidemiological investigation in 54,826 subjects from 40 countries (COMET-G study)

BACKGROUND

The prevalence of medical illnesses is high among patients with psychiatric disorders. The current study aimed to investigate multi-comorbidity in patients with psychiatric disorders in comparison to the general population. Secondary aims were to investigate factors associated with metabolic syndrome and treatment appropriateness of mental disorders.

METHODS

The sample included 54,826 subjects (64.73% females; 34.15% males; 1.11% nonbinary gender) from 40 countries (COMET-G study). The analysis was based on the registration of previous history that could serve as a fair approximation for the lifetime prevalence of various medical conditions.

RESULTS

About 24.5% reported a history of somatic and 26.14% of mental disorders. Mental disorders were by far the most prevalent group of medical conditions. Comorbidity of any somatic with any mental disorder was reported by 8.21%. One-third to almost two-thirds of somatic patients were also suffering from a mental disorder depending on the severity and multicomorbidity. Bipolar and psychotic patients and to a lesser extent depressives, manifested an earlier (15-20 years) manifestation of somatic multicomorbidity, severe disability, and probably earlier death. The overwhelming majority of patients with mental disorders were not receiving treatment or were being treated in a way that was not recommended. Antipsychotics and antidepressants were not related to the development of metabolic syndrome.

CONCLUSIONS

The finding that one-third to almost two-thirds of somatic patients also suffered from a mental disorder strongly suggests that psychiatry is the field with the most trans-specialty and interdisciplinary value and application points to the importance of teaching psychiatry and mental health in medical schools and also to the need for more technocratically oriented training of psychiatric residents.

Setting Families Up for Success: A Pilot Study of a Toolkit to Enhance the Autism Spectrum Disorder Diagnostic Evaluation Process

Families of children with autism spectrum disorder (ASD) face challenges engaging in services following diagnosis. This study: (1) developed and implemented a toolkit to tailor ASD evaluation feedback to families' needs, and (2) evaluated caregiver and provider perceptions of the toolkit. Focus groups with providers (N = 11) informed toolkit development. Seven providers participated in pilot training and implementation. Provider and caregiver toolkit perceptions were assessed using interviews, surveys, and a fidelity checklist. Toolkit strategies reflect focus group themes. Provider and caregiver ratings suggest the initial feasibility, acceptability, and utility of the toolkit. This toolkit may be feasible to implement in community settings and may increase caregiver satisfaction, though further refinements are needed to support service connection.

Results of the COVID-19 mental health international for the health professionals (COMET-HP) study: depression, suicidal tendencies and conspiracism

INTRODUCTION

The current study aimed to investigate the rates of anxiety, clinical depression, and suicidality and their changes in health professionals during the COVID-19 outbreak.

MATERIALS AND METHODS

The data came from the larger COMET-G study. The study sample includes 12,792 health professionals from 40 countries (62.40% women aged 39.76 ± 11.70; 36.81% men aged 35.91 ± 11.00 and 0.78% non-binary gender aged 35.15 ± 13.03). Distress and clinical depression were identified with the use of a previously developed cut-off and algorithm, respectively.

STATISTICAL ANALYSIS

Descriptive statistics were calculated. Chi-square tests, multiple forward stepwise linear regression analyses, and Factorial Analysis of Variance (ANOVA) tested relations among variables.

RESULTS

Clinical depression was detected in 13.16% with male doctors and 'non-binary genders' having the lowest rates (7.89 and 5.88% respectively) and 'non-binary gender' nurses and administrative staff had the highest (37.50%); distress was present in 15.19%. A significant percentage reported a deterioration in mental state, family dynamics, and everyday lifestyle. Persons with a history of mental disorders had higher rates of current depression (24.64% vs. 9.62%; p < 0.0001). Suicidal tendencies were at least doubled in terms of RASS scores. Approximately one-third of participants were accepting (at least to a moderate degree) a non-bizarre conspiracy. The highest Relative Risk (RR) to develop clinical depression was associated with a history of Bipolar disorder (RR = 4.23).

CONCLUSIONS

The current study reported findings in health care professionals similar in magnitude and quality to those reported earlier in the general population although rates of clinical depression, suicidal tendencies, and adherence to conspiracy theories were much lower. However, the general model of factors interplay seems to be the same and this could be of practical utility since many of these factors are modifiable.

The effect of different degrees of lockdown and self-identified gender on anxiety, depression and suicidality during the COVID-19 pandemic: Data from the international COMET-G study

INTRODUCTION

During the COVID-19 pandemic various degrees of lockdown were applied by countries around the world. It is considered that such measures have an adverse effect on mental health but the relationship of measure intensity with the mental health effect has not been thoroughly studied. Here we report data from the larger COMET-G study pertaining to this question.

MATERIAL AND METHODS

During the COVID-19 pandemic, data were gathered with an online questionnaire from 55,589 participants from 40 countries (64.85% females aged 35.80 ± 13.61; 34.05% males aged 34.90±13.29 and 1.10% other aged 31.64±13.15). Anxiety was measured with the STAI, depression with the CES-D and suicidality with the RASS. Distress and probable depression were identified with the use of a previously developed cut-off and algorithm respectively.

STATISTICAL ANALYSIS

It included the calculation of Relative Risk (RR), Factorial ANOVA and Multiple backwards stepwise linear regression analysis RESULTS: Approximately two-thirds were currently living under significant restrictions due to lockdown. For both males and females the risk to develop clinical depression correlated significantly with each and every level of increasing lockdown degree (RR 1.72 and 1.90 respectively). The combined lockdown and psychiatric history increased RR to 6.88 The overall relationship of lockdown with severity of depression, though significant was small.

CONCLUSIONS

The current study is the first which reports an almost linear relationship between lockdown degree and effect in mental health. Our findings, support previous suggestions concerning the need for a proactive targeted intervention to protect mental health more specifically in vulnerable groups.

Results of the COVID-19 mental health international for the general population (COMET-G) study

INTRODUCTION

There are few published empirical data on the effects of COVID-19 on mental health, and until now, there is no large international study.

MATERIAL AND METHODS

During the COVID-19 pandemic, an online questionnaire gathered data from 55,589 participants from 40 countries (64.85% females aged 35.80 ± 13.61; 34.05% males aged 34.90±13.29 and 1.10% other aged 31.64±13.15). Distress and probable depression were identified with the use of a previously developed cut-off and algorithm respectively.

STATISTICAL ANALYSIS

Descriptive statistics were calculated. Chi-square tests, multiple forward stepwise linear regression analyses and Factorial Analysis of Variance (ANOVA) tested relations among variables.

RESULTS

Probable depression was detected in 17.80% and distress in 16.71%. A significant percentage reported a deterioration in mental state, family dynamics and everyday lifestyle. Persons with a history of mental disorders had higher rates of current depression (31.82% vs. 13.07%). At least half of participants were accepting (at least to a moderate degree) a non-bizarre conspiracy. The highest Relative Risk (RR) to develop depression was associated with history of Bipolar disorder and self-harm/attempts (RR = 5.88). Suicidality was not increased in persons without a history of any mental disorder. Based on these results a model was developed.

CONCLUSIONS

The final model revealed multiple vulnerabilities and an interplay leading from simple anxiety to probable depression and suicidality through distress. This could be of practical utility since many of these factors are modifiable. Future research and interventions should specifically focus on them.

Downregulation of polymeric immunoglobulin receptor and secretory IgA antibodies in eosinophilic upper airway diseases

BACKGROUND

Immunoglobulin (Ig) A represents a first-line defence mechanism in the airways, but little is known regarding its implication in upper airway disorders. This study aimed to address the hypothesis that polymeric Ig receptor (pIgR)-mediated secretory IgA immunity could be impaired in chronic upper airway diseases.

METHODS

Nasal and ethmoidal biopsies, as well as nasal secretions, were collected from patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) or without nasal polyps (CRSsNP), allergic rhinitis (AR) and controls, and assayed for IgA1/IgA2 synthesis, pIgR expression, production of secretory component (SC), IgA and relevant IgA antibodies, and correlated with local eosinophils and inflammatory features (IL-12, IL-13 and ECP).

RESULTS

pIgR expression was decreased in the ethmoidal mucosa in patients with CRSwNP (P = 0.003) and in AR (P = 0.006). This pIgR defect was associated with reduced levels of SC (P = 0.007) and IgA antibodies to Staphylococcus aureus enterotoxin B (SAEB) (P = 0.003) in nasal secretions from patients with CRSwNP, and with increased IgA deposition in subepithelial areas. pIgR downregulation was selectively observed in patients with tissue eosinophilia, whilst no clear relation to smoking history was observed.

CONCLUSION

Epithelial pIgR expression is decreased in patients with CRSwNP and AR and results in decreased SC and IgA antibodies to certain bacterial antigens (SAEB) in nasal secretions of patients with CRSwNP in parallel to subepithelial accumulation of IgA. This defect in mucosal immunity is associated with eosinophilic, Th2-related inflammation.

Calcaneal ultrasound reference ranges for Australian men and women: the Geelong Osteoporosis Study

Heel ultrasound is a more portable modality for assessing fracture risk than dual-energy X-ray absorptiometry and does not use ionising radiation. Fracture risk assessment requires appropriate reference data to enable comparisons. This study reports the first heel ultrasound reference ranges for the Australian population.

INTRODUCTION

This study aimed to develop calcaneal (heel) ultrasound reference ranges for the Australian adult population using a population-based random sample.

METHODS

Men and women aged≥20 years were randomly selected from the Barwon Statistical Division in 2001-2006 and 1993-1997, respectively, using the electoral roll. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were measured at the heel using a Lunar Achilles Ultrasonometer. Gender-specific means and standard deviations for BUA, SOS and SI were calculated for the entire sample (men 20-93 years, n=1,104; women 20-92 years, n=914) and for participants aged 20-29 years (men, n=157; women, n=151). Associations between ultrasound measures and age were examined using linear regression.

RESULTS

For men, mean±standard deviation BUA, SOS and SI were 118.7±15.8 dB/MHz, 1,577.0±43.7 m/s and 100.5±20.7, respectively; values for women were consistently lower (111.0±16.4 dB/MHz, P<0.001; 1,571.0±39.0 m/s, P=0.001; and 93.7±20.3, P<0.001, respectively). BUA was higher in young men compared with young women (124.5±14.4 vs 121.0±15.1 dB/MHz), but SOS (1,590.1±43.1 vs 1,592.5±35.0 m/s) and SI (108.0±19.9 vs 106.3±17.7) were not. The relationships between age and each ultrasound measure were linear and negative across the age range in men; associations were also negative in women but non-linear.

CONCLUSION

These data provide reference standards to facilitate the assessment of fracture risk in an Australian population using heel ultrasound.

Mucosal tissue polyclonal IgE is functional in response to allergen and SEB

BACKGROUND

Staphylococcus aureus may modify airway disease by inducing local formation of polyclonal IgE antibodies (abs), the role of which is unknown.

METHODS

Nasal mucosal tissue and serum was obtained from 12 allergic rhinitis (AR) and 14 nasal polyp (NP) subjects. Skin prick tests were performed, and total and specific IgE abs to inhalant allergens and enterotoxin B were determined in serum and tissue. Tissue fragments were stimulated with anti-IgE, enterotoxin B, or grass and house dust mite allergens in different concentrations for 30 min. RBL SX38 cells were sensitized with NP homogenates containing IgE and stimulated with grass pollen extracts.

RESULTS

In AR patients, degranulation of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens corresponded in almost all cases. Total IgE concentrations in serum and mucosal tissue homogenates highly correlated. In contrast, in NP patients, reactivity of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens or Staphylococcus aureus enterotoxin B corresponded for tissue, but not for serum. Total IgE was significantly higher in tissue compared to serum and failed to show correlation. Tissue IgE to grass pollen was functional to degranulate RBL cells.

CONCLUSION

We here demonstrate that mucosal IgE abs in NP tissue are functional and able to activate mast cells; specific IgE abs in NP tissue can be found independently of their presence in serum. We postulate that superantigen-induced polyclonal IgE in airway disease contributes to chronic inflammation by continuously activating mast cells.

AllergoOncology: the role of IgE-mediated allergy in cancer

Epidemiological studies have suggested inverse associations between allergic diseases and malignancies. As a proof of concept for the capability of immunoglobulin E (IgE) to destruct tumor cells, several experimental strategies have evolved to specifically target this antibody class towards relevant tumor antigens. It could be demonstrated that IgE antibodies specific to overexpressed tumor antigens have been superior to any other immunoglobulin class with respect to antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) reactions. In an alternative approach, IgE nonspecifically attached to tumor cells proved to be a powerful adjuvant establishing tumor-specific immune memory. Active Th2 immunity could also be achieved by applying an oral immunization regimen using mimotopes, i.e. epitope mimics of tumor antigens. The induced IgE antibodies could be cross-linked by live tumor cells leading to tumoricidic mediator release. Thus, IgE antibodies may not only act in natural tumor surveillance, but could possibly also be exploited for tumor control in active and passive immunotherapy settings. Thereby, eosinophils, mast cells and macrophages can be armed with the cytophilic IgE and become potent anti-tumor effectors, able to trace viable tumor cells in the tissues. It is strongly suggested that the evolving new field AllergoOncology will give new insights into the role of IgE-mediated allergy in malignancies, possibly opening new avenues for tumor therapy.

Clusters and fluctuations at mean-field critical points and spinodals

We show that the structure of the fluctuations close to spinodals and mean-field critical points is qualitatively different from the structure close to non-mean-field critical points. This difference has important implications for many areas including the formation of glasses in supercooled liquids. In particular, the divergence of the measured static structure function in near-mean-field systems close to the glass transition is suppressed relative to the mean-field prediction in systems for which a spatial symmetry is broken.

Cluster monte carlo study of multicomponent fluids of the stillinger-helfand and widom-rowlinson type

Phase transitions of fluid mixtures of the type introduced by Stillinger and Helfand are studied using a continuum version of the invaded cluster algorithm. Particles of the same species do not interact, but particles of different types interact with each other via a repulsive potential. Examples of interactions include the Gaussian molecule potential and a repulsive step potential. Accurate values of the critical density, fugacity, and magnetic exponent are found in two and three dimensions for the two-species model. The effect of varying the number of species and of introducing quenched impurities is also investigated. In all the cases studied, mixtures of q species are found to have properties similar to q-state Potts models.

Local synthesis of epsilon germline gene transcripts, IL-4, and IL-13 in allergic nasal mucosa after ex vivo allergen exposure

BACKGROUND

The production of epsilon germline gene transcripts (Iepsilon(+)/Cepsilon(+) RNA) precedes class switch recombination to IgE and is induced by IL-4 and/or IL-13. Although Iepsilon and Cepsilon RNA(+) B cells have been identified within nasal tissue after in vivo allergen exposure, suggesting local germline transcription, whether these were resident or infiltrating B lymphocytes was not clear.

OBJECTIVE

We sought to examine whether B cells resident to the nasal mucosa undergo epsilon germline transcription.

METHODS

Nasal mucosal biopsy specimens were obtained from asymptomatic patients with seasonal allergic rhinitis and exposed to allergen ex vivo. Using immunocytochemistry, B lymphocytes were enumerated; with in situ hybridization, the number of cells expressing Iepsilon, Cepsilon, IL-4, and IL-13 messenger (m)RNA(+) cells was examined.

RESULTS

Tissue cultured in medium containing specific allergen exhibited significantly more Iepsilon and Cepsilon RNA(+) cells compared with medium alone (P <.05). IL-4 and IL-13 mRNA synthesis also resulted from ex vivo allergen exposure; there were significantly more cells expressing transcripts for these cytokines within allergic nasal mucosal tissue cultured with allergen than medium alone (P <.05). Within allergen-stimulated tissue obtained from allergic patients, 30% of total B cells were Iepsilon RNA(+), and the majority of IL-4 and IL-13 mRNA(+) cells were T cells (68% and 44%, respectively) and mast cells (32% and 19%, respectively).

CONCLUSION

These results demonstrate that the nasal mucosa is a site of epsilon germline gene transcription and suggest that local T cell and mast cell production of IL-4 and IL-13 may regulate this event.

A conceptual model for the recruitment of diverse women into research studies

Researchers' understanding of recruitment and retention of study subjects is in its infancy. To address the dearth of information on the underrepresentation of diverse populations of women in research studies relating to health issues, the University of California, San Francisco (UCSF) National Center of Excellence in Women's Health completed a comprehensive examination of issues related to recruitment. By synthesizing data from literature reviews, focus groups, surveys, one-on-one interviews, and direct experience recruiting diverse populations of women for research, a conceptual model was developed. This model outlines the interplay of three factors found to be relevant to the recruitment of diverse populations of women into research studies: awareness, acceptance, and access. Practical examples of cost-effective recruitment strategies to be considered for implementation to increase the presence of awareness, acceptability, and access are included in this report.

Does laser trabeculoplasty prevent steroid glaucoma?

OBJECTIVE

To investigate the effect of laser trabeculoplasty in the normal myopic eye on steroid intraocular pressure responsiveness in patients undergoing radial keratotomy.

MATERIALS AND METHODS

Diode laser trabeculoplasty was performed on 94 patients with myopia undergoing radial keratotomy who were then started on dexamethasone drops. Intraocular pressures were measured by applanation tonometry compensated for corneal flattening.

RESULTS

Twenty-eight percent of patients had an intraocular pressure increase of 6 mm Hg or more by the fourth week.

CONCLUSION

Laser trabeculoplasty does not prevent steroid intraocular pressure increase in patients with myopia.

Expression of CD21 is developmentally regulated during thymic maturation of human T lymphocytes

CD21, the C3d/CD23/Epstein-Barr virus (EBV), receptor is expressed at low density on cells of the T lineage. Immature thymocytes express CD21 with high density. In the present study, we have analyzed the expression of CD21 during intrathymic maturation of T cells. An intense staining for CD21 was observed at the double-negative stage and at the stage of early acquisition of CD4. CD21 expression was decreased at the double-positive and single-positive stages, to then reach levels similar to those of peripheral blood T cells. Staining of thymus sections showed a bright fluorescent signal on thymocytes entering the thymus in the cortical region. Taking advantage of the immature phenotype of cells expressing high amounts of CD21 (CD21(++)), we depleted thymocyte suspensions in CD3(+) and CD8(+) cells to study the properties of CD21 on this cell subset. Triggering of CD21 with its ligands iC3b, CD23 and anti-CD21 mAb did not alter the proliferative response of thymocytes to IL-7, and did not induce the differentiation of early cells into CD4(+)CD8(+) thymocytes. Immunoprecipitation did not reveal any molecule associated with CD21 that could play a signaling role in thymocytes. Finally, EBV induced a down-regulation of CD21 and an up-regulation of CD1 in CD21(++) thymocytes. Taken together, our observations demonstrate a regulated expression of CD21 on human thymocytes and suggest that the CD21(++) subset may be a target for EBV. We further suggest that CD21 on early thymocytes acts as a ligand for CD23-expressing cells in the thymus.

Alternate promoters and developmental modulation of expression of the chicken GATA-2 gene in hematopoietic progenitor cells

We have isolated and characterized the chicken GATA-2 (cGATA-2) gene. We show that, as in the case of some other members of the GATA gene family, the gene is expressed from alternative first exons. One of the resulting mRNAs represents only a minor form of the GATA-2 mRNA in the cells and tissues we analyzed; the other is ubiquitously expressed. We have defined the minimal promoter that controls expression of this most abundant mRNA and that is necessary for full activity in hematopoietic progenitor cells. The activity of this promoter in transient assays is consistent with developmental differences of expression levels in these cells. We identify within the promoter a previously unrecognized extended CCAAT motif essential for its activity. The organization of the cGATA-2 gene, with alternative first exons and a CCAAT box in the proximal promoter, is similar to that recently described for mouse GATA-2, and the proximal promoter also resembles the only promoter so far described in Xenopus. Nonetheless, the roles of the promoters in development and tissue-specific expression are quite different in these organisms, most strikingly in the mouse, which assigns developmental roles to its proximal and distal promoters that are quite different from those in the chicken. We suggest that although the overall organization may remain the same, the role assigned to each promoter varies among organisms. We identify distant upstream regulatory elements in the cGATA-2 gene that modulate expression from the proximal promoter and that may be responsible for this variation.

[Value of computerized tomography in diagnosis of small intestine injuries after blunt abdominal trauma]

Intestinal injury is increasing in frequency among persons sustaining blunt abdominal trauma, and the consequences of delayed recognition of intestinal injuries are serious. This critical retrospective analysis evaluates the role for CT in the diagnosis of blunt abdominal trauma, including hollow visceral injury. CT scan, when used in conjunction with a history emphasizing the mechanism of injury and a careful physical examination, is highly accurate in detecting small bowel injuries. CT is less helpful in distinguishing between different types of small bowel injury. Intestinal wall thickening with low-density fluid in the abdominal cavity strongly suggests rupture. Until further experience is gained with CT, free intraperitoneal fluid in the absence of solid organ injury should be regarded as an indication for exploratory laparotomy.

Tube thoracostomy for occult pneumothorax: a prospective randomized study of its use

Occult pneumothorax is defined as a pneumothorax that is detected by abdominal computed tomographic (CT) scanning, but not routine supine screening chest roentgenograms. Forty trauma patients with occult pneumothorax were prospectively randomized to management with tube thoracostomy (n = 19) or observation (n = 21) without regard to the possible need for positive pressure ventilation, to test the hypothesis that tube thoracostomy is unnecessary in this entity. Eight of the 21 patients observed had progression of their pneumothoraces on positive pressure ventilation, with three developing tension pneumothorax. None of the patients with tube thoracostomy suffered major complications as a result of the procedure. Hospital and ICU lengths of stay were not increased by tube thoracostomy. Patients with occult pneumothorax who require positive pressure ventilation should undergo tube thoracostomy.

Developmental regulation of globin gene expression

We have used the globin family of genes in chicken to study developmental regulation of gene expression, both at the level of individual interaction of trans-acting factors with local promoters and enhancers, and at the level of chromatin structure. Regulation of all members of the alpha- and beta-globin clusters is affected by the erythroid regulatory factor GATA-1. Separate mechanisms exist for regulation of individual members of the family. As an example, we describe the control mechanisms that play a role in the expression of the rho-globin gene, which is expressed only in primitive lineage erythroid cells. In addressing the involvement of chromatin structure in gene activation, we have examined the role of locus control elements, and also considered the way in which RNA polymerase molecules might accommodate to the presence of nucleosomes on transcribed genes.

Structure and promoter activity of the gene for the erythroid transcription factor GATA-1

We have cloned the gene for the chicken erythroid transcription factor GATA-1 (formerly Eryf1, NF-E1, or GF-1). The gene is composed of six exons, two of which encode the two finger domains of the protein. Transcription of GATA-1 in chicken embryonic erythroid cells initiates from multiple sites clustered approximately 200 base pairs upstream from the start of protein-coding sequence. A number of sequence motifs for known DNA-binding proteins are found to be protected in DNase I-footprinting experiments by either erythroid or brain nuclear extracts or by both. Notably, a cluster of three GATA-1 sites is protected by the erythroid extract, as well as by purified GATA-1. We find that the upstream region of the gene functions as a powerful promoter when transfected into embryonic erythroid cells. In primary chicken embryo fibroblasts the promoter exhibits lower activity, which is increased when the cells are cotransfected with a second plasmid expressing the GATA-1 cDNA. The results suggest that GATA-1 protein plays an autoregulatory role in its own expression.

Purification and characterization of Ku-2, an octamer-binding protein related to the autoantigen Ku

The octamer motif (ATTTGCAT) is an important regulatory element in eukaryotic gene expression. A previously unidentified protein that recognizes this motif has been isolated from the human B cell line, Daudi. The protein, which we term Ku-2, bears a close resemblance to the DNA-binding autoantigen Ku. Like Ku, it is a heterodimer with subunits of 83 and 72 kDa; antisera raised against either subunit of Ku cross-react with Ku-2. Two peptides have been sequenced and show a strong similarity to regions in the corresponding subunits of Ku. The sequences are not identical, however, suggesting that Ku-2 may be a B cell homologue of Ku. Both Ku and Ku-2 bind to the termini of DNA duplexes, but Ku-2 also binds to an internal octamer motif. It is not known whether Ku shares the latter property or whether the octamer binding is a consequence of sequence differences between the two proteins. Ku-2 does not react with antisera against the POU domain of the octamer-binding protein Oct-2, indicating that the DNA binding domains of the two proteins are dissimilar despite the ability of both to bind to the octamer motif. We discuss the evidence for the existence of a family of octamer-binding proteins related to Ku.

Chemical characterization of the parasitophorous vacuole membrane antigen QF 116 from Plasmodium falciparum

On the basis of amino acid sequencing and immunological cross-reactivity, the Plasmodium falciparum parasitophorous vacuole antigens QF116 and exp-1/CRA are apparently identical. The epitope recognized by an inhibitory monoclonal antibody directed against QF116 is located proximal to the C-terminus of the protein. The QF116 protein is processed during maturation by the cleavage of a 22-amino-acid signal peptide and acylated as measured by labeling with myristic acid.

Blocking of passive sensitization of human mast cells and basophil granulocytes with IgE antibodies by a recombinant human epsilon-chain fragment of 76 amino acids

The recombinant peptide corresponding to residues 301-376 at the junction of constant regions 2 and 3 of the human IgE epsilon chain blocked the in vivo passive sensitization of human skin mast cells and in vitro sensitization of human basophil granulocytes with human IgE antibodies. An injection of the recombinant peptide or E myeloma protein into normal skin sites 1 hr before sensitization with an allergic serum blocked passive sensitization. In this system, approximately 10-fold higher molar concentration of the recombinant peptide than E myeloma protein was required for 50% inhibition of Prausnitz-Küstner reactions. When the mononuclear cells of two normal individuals were preincubated with the recombinant peptide or E myeloma protein for 15 min before passive sensitization with the same allergic serum and the cells were challenged with an optimal concentration of an antigen, approximately 11- to 13-fold higher concentration of the recombinant peptide than E myeloma protein was required for 50% inhibition of antigen-induced histamine release. Further studies with several recombinant peptides indicated that amino acid resides 363-376 in the Fc epsilon-chain fragment are not essential for binding of the peptide to Fc epsilon-chain receptor I.

Immune response to a synthetic peptide corresponding to an epitope of a parasitophorous vacuole membrane antigen from Plasmodium falciparum

The parasitophorous vacuole membrane antigen QF 116 from Plasmodium falciparum contains a defined epitope, DNNLVSGP, proximal to the carboxyl-terminus which binds to the inhibitory monoclonal antibody 8E7/55. A synthetic peptide containing this epitope was constructed and coupled to diphtheria toxoid as carrier. Mice and rabbits were inoculated with this conjugate using CFA, SAF-1, or aluminum phosphate as adjuvants. The peptide conjugate was highly immunogenic in both animal species, giving rise to polyclonal antibodies with a similar epitope specificity as the original mAb. Antibody titers were dependent on the route of immunization. Rabbit antibodies produced in sufficient quantity for biologic assays inhibited parasite growth in vitro. This synthetic peptide thus shows promise as an immunogen for use in synthetic vaccine design.

Immune response to a synthetic peptide corresponding to an epitope of a parasitophorous vacuole membrane antigen from Plasmodium falciparum

The parasitophorous vacuole membrane antigen QF 116 from Plasmodium falciparum contains a defined epitope, DNNLVSGP, proximal to the carboxyl-terminus which binds to the inhibitory monoclonal antibody 8E7/55. A synthetic peptide containing this epitope was constructed and coupled to diphtheria toxoid as carrier. Mice and rabbits were inoculated with this conjugate using CFA, SAF-1, or aluminum phosphate as adjuvants. The peptide conjugate was highly immunogenic in both animal species, giving rise to polyclonal antibodies with a similar epitope specificity as the original mAb. Antibody titers were dependent on the route of immunization. Rabbit antibodies produced in sufficient quantity for biologic assays inhibited parasite growth in vitro. This synthetic peptide thus shows promise as an immunogen for use in synthetic vaccine design.

The B-cell binding site on human immunoglobulin E

Immunoglobulin E comprises the main immunoglobulin class associated with allergy. Its multifarious activities are mediated by two types of Fc receptors found on different cell populations, Fc epsilon R1 on mast cells and basophils, and Fc epsilon R2 on inflammatory cells (monocytes, eosinophils and platelets) and B lymphocytes. Recombinant epsilon-chain fragments synthesized in Escherichia coli have provided the means of mapping the receptor-binding sites on human IgE, and blocking IgE-receptor interactions. We have previously shown that the Fc epsilon R1 binding site is contained within a sequence (Gln 301-Arg 376) spanning the C epsilon 2 and C epsilon 3 domains. Here we show that Fc epsilon R2 can recognize a motif in the C epsilon 3 domain that is formed on dimerization of one or both of the flanking (C epsilon 2 and C epsilon 4) domains. Glycosylation of IgE is not required for the activity of either receptor.

Comparison of the identifiability of the low intensity ABR and MLR in the mentally handicapped patient

The auditory brain stem response and the middle latency response were recorded from low intensity click stimuli in 48 patients with mental handicaps. In the 23 patients (45 ears) with normal hearing thresholds, the ABR was found to have a lower test-retest variability than the MLR. This lower variability will correspond to higher identifiability at threshold. In the 25 patients with a hearing loss, four had MLRs recorded in ears with absent ABRs. In five of these ears no auditory response would have been detected if ABRs alone were recorded. Based on the above findings, the following recommendations can be made. Recording the ABR with open filters is the desired method for threshold detection in most subjects. If no response is obtained it is desirable to record a MLR. The recording of a MLR is probably more important in laboratories recording responses with steep filter slopes, since a greater portion of the slow wave activity, P phi (V) complex, will be phase shifted into the later portion of the time base.

Effect of monoclonal antihuman IgE on recombinant IgE(301-376) inhibition of specific IgE histamine release

To explore the binding domains of rCIgE(301-376) necessary for inhibition of passive transfer of rye grass and Chinese elm IgE to human basophils, we employed monoclonal antibodies known to bind to IgE(301-336), M-272, and to IgE(367-376), M-27. By preincubating M-272, but not M-27, with rCIgE(301-376), passive transfer of specific IgE to basophils was partially inhibited. This implies that M-272 recognizes a binding site on rCIgE(301-376) or sterically interferes with the rCIgE(301-376) high-affinity binding domains on human basophils.

An erythrocyte-specific protein that binds to the poly(dG) region of the chicken beta-globin gene promoter

The promoter region of the chicken adult beta-globin gene contains a sequence of 16 deoxyguanosine residues located at a nucleosome boundary in tissues where the gene is inactive. In definitive erythrocytes that express the beta-globin gene, the nucleosome is displaced, the G-string and adjacent sequences are occupied by sequence-specific DNA-binding proteins, and a nuclease hypersensitive domain is generated in this region. To gain insight into the role of the G-string in this series of events, we have examined the proteins that bind to it. Using the gel mobility shift assay and a monoclonal antibody that blocks specific binding to the G-string, we have identified a specific protein, BGP1, that is found only in chicken erythroid cells and appears at the same time, or shortly before, the changes in chromatin structure. The antibody interacts strongly with BGP1 and cross-reacts weakly with Sp1. Although both BGP1 and Sp1 require Zn2+ for their DNA-binding activity, these proteins differ in their binding-site specificities, chromatographic properties, and molecular weights. In contrast to Sp1, which is found in a wide variety of cell types, BGP1 is restricted to erythrocytes and is most abundant in definitive erythrocytes. Thus, its presence corresponds to the tissue- and stage-specific occupancy of the G-string in vivo.

The mast cell binding site on human immunoglobulin E

Antibodies of the immunoglobulin E isotype sensitize mast cells and basophils for antigen-induced mediator release by binding through the Fc portion to a high-affinity receptor (Fc epsilon R1, Ka = 10(9)M-1) on the cell surface causing the clinical manifestations of type I hypersensitivity. As the amino acid sequence of the human epsilon chain is now known, attempts have been made to map the Fc epsilon R1 binding site on IgE to a fragment smaller than Fc epsilon using proteolytic cleavage products, none of which proved to be active. Cleavage between the C epsilon 2 and C epsilon 3 domains released two inactive fragments, suggesting that the junction between these segments could be important in receptor binding. This region is protected against protease digestion in the rat IgE complex with the receptor of rat basophilic leukaemia cells. Here we report the mapping of the mast cell receptor binding site on human IgE to a sequence of 76 amino acids at the C epsilon 2/C epsilon 3 junction. Recombinant peptides containing this sequence inhibit passive sensitization of skin mast cells in vivo and sensitize mast cells to degranulation by anti-IgE in vitro almost as efficiently as a myeloma IgE. Fragments containing the separate domains are inactive. Additional sequences are required for rapid assembly of fragments into disulphide-linked dimers, suggesting that a single chain can form the active site. In a three-dimensional model of the human Fc epsilon, the two identical segments are far apart. Each folds to generate a cleft between the C epsilon 2 and C epsilon 3 domains on the surface of the Fc epsilon. The docking of IgE on to mast cells could take place within this cleft.