An Emergent Theory Depicting Patients' Fortitude Through the Healing and Recovering Process of Depression

BACKGROUND

Depression is a common mental disorder. Literature has explored patients' perspectives of the recovering process of depression. However, there is a lack of research to explore both patients' and caregivers' perspectives of the healing process and develop a theory to support patients with depression.

AIMS

The purpose of this study is to develop a substantive theory that depicts patients with depression toward healing and recovering.

METHODS

This study used a grounded theory approach and collected data between 2019 and 2020 in a medical center in Taiwan. A theoretical sampling was performed after interviewing 29 participants, including 20 patients who had recovered from depression and nine caregivers; data saturation was achieved. Data analysis was conducted with open, axial, and selective coding and used NVivo Version 11 to aid the process of coding.

RESULTS

A substantive theory was developed and the core category was "Patients' fortitude through the healing and recovering process of depression." Other main categories interrelated in this core category were reframing negative thinking and cultivating positive thinking, rebuilding a positive self-worth by embracing self-compassion, and learning to cope with everyday stress.

CONCLUSIONS

This theory could help health care professionals to work therapeutically with patients and commend their fortitude while experiencing depression and engaging them with the care they planned together; and find some joy in life. Educators and researchers could use this theory to advance nursing care.

The Morbidity and Associated Factors of Depression in Caregivers of Patients with Depressive Disorder

Objective

Depressive disorder significantly impacts patients' daily living activities and quality of life. Caregivers of patients with depression may also suffer from psychological distress related to the chronic burden of caring for the patient's mood changes. The purpose of this study was to evaluate the morbidity and associated factors of depression in caregivers of patients with depressive disorder.

Methods

In this study, we used a cross-sectional design with consecutive sampling. Study subjects were recruited from the psychiatric outpatient clinic of a medical center from August 2021 to June 2022. Caregivers of depressive disorder patients were enrolled and assessed using the Mini International Neuropsychiatric Interview, Hospital Anxiety and Depression Scale (HADS), Suicide Assessment Scale (SAS), Stigma Scale of the Explanatory Model Interview Catalogue (EMIC), and Family APGAR Index.

Results

Of the 120 caregivers that completed the study, 59.2% (n=71) were females. The most common psychiatric diagnosis was depressive disorders (25.8%), followed by anxiety disorders (17.5%) and insomnia disorder (15.8%); 54.2% of the caregivers had a psychiatric diagnosis. Using logistic regression analysis, we found that anxiolytics/hypnotics use (OR=5.58; 95% CI, 1.84-16.96; p<0.01), higher suicide risk (SAS) (OR=1.10; 95% CI, 1.05-1.16; p<0.001), and lower family support (APGAR scores) (OR=0.82; 95% CI, 0.71-0.94; p<0.01) were three significant associated factors.

Conclusion

Depression was the most prevalent psychiatric diagnosis in caregivers of patients with depressive disorder. Early psychiatric diagnosis for caregivers of patients with depression is crucial to offering suitable support and treatment and may improve caregivers' quality of life.

Management for A Depressive Patient with Femoral Neck Fracture by Electroconvulsive Therapy during COVID-19 Pandemic: A Case Report and Literature Review

Electroconvulsive therapy (ECT) is an effective treatment for refractory major depressive disorder with suicidal ideation. The most common adverse medical events are transient retrograde amnesia, falls and pneumonia. Hip fractures, associated with high-energy trauma by convulsions, were occasionally reported in western countries, in the period before the COVID-19 pandemic. Strict COVID-19 regulations influenced the course and further investigation of the treatment of post-ECT complications. A 33-year-old man, previously diagnosed with major depressive disorder, had a history of nine successful sessions of ECT treatment for depression five years ago. He was hospitalized again for 12 sessions of ECT for recurrent depression. Unfortunately, an ECT-induced right hip-neck fracture was noted after the ninth session of ECT, in March 2021. After receiving close reduction and internal fixation of the right femoral neck fracture, with three screws, his original daily function was restored. His treatment was regularly followed up at the outpatient clinic for 20 months; he achieved partial remission with three combined antidepressants. This case of ECT-induced right hip-neck fracture informed psychiatric staff to be aware of this rare adverse complication and ensure its appropriate management, especially during the COVID-19 pandemic.

The effects of logotherapy on meaning in life, depression, hopelessness, and suicidal ideation, in patients with depression: An intervention study

PURPOSE

To evaluate the efficacy of logotherapy on meaning in life, depression, hopelessness, and suicide ideation in patients with depression.

DESIGN AND METHODS

A quasi-experimental approach was used and 86 participants were recruited from a psychiatric department in Taiwan. The experimental group received logotherapy for 12 weeks. The control group received depression education as usual.

FINDINGS

The results revealed significant differences between and within the groups for meaning in life, depression, hopelessness, and suicide ideation.

PRACTICE IMPLICATIONS

Logotherapy was an effective method for increasing meaning in life, reducing the degree of depression, hopelessness, and suicidal ideation for patients with depression.

Psychological Reactions of Hospital Workers to a Pandemic: A Comparison of SARS-CoV-2 in 2020 and SARS in 2003

Epidemic viral infections, including the outbreak of severe acute respiratory syndrome (SARS) in 2003 and SARS-CoV-2 in 2019, have brought tremendous loss to people across the nations. The aim of this study was to compare the psychological impact of the SARS-CoV-2 pandemic in 2020 and the SARS pandemic in 2003 on hospital workers. Hospital workers at a medical center in Southern Taiwan (n = 1816) were invited to complete questionnaires (SARS-CoV-2 Exposure Experience, the Impact of Event Scale, the Chinese Health Questionnaire, and the Distress Thermometer). The current data were compared to the data collected from hospital workers (n = 1257) at the same medical center during the SARS pandemic in 2003. We found the psychological impact on hospital workers during the SARS-CoV-2 pandemic was significantly lower than that during the previous SARS period. During the SARS-CoV-2 pandemic period, hospital workers with SARS experience were more accepting of the risk, felt a greater responsibility to take care of the SARS-CoV-2 patients, and were more likely to perceive the danger of becoming infected. The associated factors of psychiatric morbidity in hospital workers with SARS experience were being female, the degree of intrusion severity, and severity of psychological distress. Proper management strategies and lessons learned from the SARS experience might have led to low psychiatric morbidity during the SARS-CoV-2 pandemic.

Exploring the meaning of life from the perspective of patients with depression: A phenomenological study

This study explored the perceptions of meaning of life for patients with depression. A qualitative phenomenology approach was used. Patients with depression (n = 20) were recruited until data saturation occurred. Findings revealed four themes all related to their value of: (1) accepting depression; (2) appreciating work (paid and non-paid); (3) embodying love and taking on responsibilities; (4) receiving spiritual comfort. Healthcare professionals could facilitate patients with depression to explore their meaning of life while enduring and transforming the emotional pain that accompanies depression, hence, perhaps, decreasing their suicidal ideations.

Successful Electroconvulsive Therapy for a 74-year-old Female with Major Depressive Disorder and Tardive Tremor: A Case Report and Literature Review

Tardive tremor is an infrequently form of tardive syndrome that is developed from prolonged treatment with dopamine receptor blocking agents. This condition presents as a prominent tremor that may cause significant distress but currently lacks effective treatment. Electroconvulsive therapy (ECT) has been applied to treat tardive syndrome. In this study, we report a 74-year-old female patient with major depressive disorder, whose tardive tremor and depressive symptoms showed remarkable improvement after receiving 10 sessions of ECT treatment.

The effects of alpha asymmetry and high-beta down-training neurofeedback for patients with the major depressive disorder and anxiety symptoms

BACKGROUND

Alpha-asymmetry neurofeedback (ALAY) was applied to patients with major depressive disorder (MDD) based on the theory of frontal alpha asymmetry. Neurophysiological studies have found a higher high-beta activity of electroencephalography (EEG) at the posterior cortex among patients with comorbid MDD and anxiety symptoms. The present study examined the effects of ALAY and high-beta down-training (Beta) neurofeedback in symptoms of depression and anxiety and EEG parameters.

METHOD

Eighty-seven patients with comorbid MDD and anxiety symptoms were allocated to the ALAY, Beta, or control groups. Both neurofeedback groups received ten-session neurofeedback. All participants completed the Beck Depression Inventory II (BDI-II), Beck Anxiety Inventory (BAI), and five minutes resting EEG recording at pre-test and post-test. EEG raw signals were transformed into an A1 score [log (F4 alpha) - log (F3 alpha)], P3 and P4 high-beta power.

RESULTS

BDI-II and BAI scores decreased at post-test in both ALAY and Beta groups, but no significant difference between the two groups. No significant interaction effect in A1 score at pre-test and post-test between the ALAY, Beta, and control groups. The P3 high-beta was significantly decreased in the Beta group, an increase in the control group, and no change in the ALAY group at post-test compared to the pre-test.

CONCLUSIONS

Both neurofeedback groups decreased symptoms of depression and anxiety. The Beta group was more effective in decreasing high-beta power at the parietal cortex compared to other groups. This non-invasive psychological intervention can be used in the future for patients with comorbid MDD and anxiety symptoms.

Anxiety and depression in patients with head and neck cancer: 6-month follow-up study

OBJECTIVE

We aimed to assess psychiatric morbidities of patients with head and neck cancer (HNC) in a prospective study at pretreatment, and 3 and 6 months after treatment, and to compare their health-related quality of life (HRQL) between those with and without depressive disorders (depression).

MATERIALS AND METHODS

Patients with newly diagnosed HNC from a tertiary hospital were recruited into the study. They were assessed for psychiatric morbidities using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Their HRQL was simultaneously evaluated using the quality of life questionnaire of the European Organisation for Research and Treatment of Cancer with a specific module for head and neck cancer; and depressed and nondepressed HNC patients were compared by using the generalized mixed-effect model for repeated measurements.

RESULTS

A total of 106 patients were recruited into this study. High rates of anxiety were found at pretreatment, but steadily declined over time (from 27.3% to 6.4%, and later 3.3%). A skew pattern of depression was observed, with prevalence rates from 8.5% at pretreatment to 24.5% and 14% at 3 and 6 months, respectively, after treatment. We found that loss of sense (P=0.001), loss of speech (P<0.001), low libido (P=0.001), dry mouth (P<0.001), and weight loss (P=0.001) were related to depression over time. The depressed patients had a higher consumption of painkillers (P=0.001) and nutrition supplements (P<0.001). The results showed that depression was predicted by sticky saliva (P<0.001) and trouble with social contact (P<0.001) at 3 months, and trouble with social eating (P<0.001) at 6 months.

CONCLUSION

Patients with HNC experienced different changes in anxiety and depression in the first 6 months of treatment. Dysfunction in salivation, problems with eating, and problems with social contacts were major risk factors for depression.

Prevalence and related factors of psychological distress among cancer inpatients using routine Distress Thermometer and Chinese Health Questionnaire screening

BACKGROUND

Clinical practice guidelines suggest routine screening for distress among cancer patients for immediate early psychiatric care. However, previous studies focusing on routine screening for psychological distress among cancer inpatients in Taiwan are scant. Thus, the aim of this study was to evaluate the prevalence and related factors of psychological distress and mental illness among cancer inpatients in Taiwan.

PATIENTS AND METHODS

This study was conducted as a retrospective chart review in a general hospital in southern Taiwan. Cancer inpatients were regularly screened by nursing staff using the Distress Thermometer and the 12-item Chinese Health Questionnaire. Positive screening results on either instrument were followed by a non-commanded referral to psychiatrists for clinical psychiatric diagnosis and treatment.

RESULTS

Of the 810 participants in this study, 179 (22.1%) were recognized as having psychological distress. Younger age (odds ratio [OR] =1.82), having head and neck cancer (OR =2.43), and having not received chemotherapy (OR =1.58) were significantly related to psychological distress. Among the 56 patients (31.3%) with psychological distress who were referred to psychiatrists, the most common mental illness was adjustment disorder (n=22, 39.2%), followed by major depressive disorder (n=13, 23.2%), depressive disorder not otherwise specified (n=6, 10.7%), and anxiety disorder not otherwise specified (n=4, 7.1%).

CONCLUSION

Our study indicated that cancer inpatients with psychological distress were more likely to be younger in age, have head and neck cancer, and have not received chemotherapy. The most common psychiatric disorder was adjustment disorder. Early detection of psychological distress and prompt psychiatric consultation and management are very important for cancer inpatients.

Electroconvulsive therapy without consent from patients: one-year follow-up study

INTRODUCTION

No previous study has been designed to analyze the reasons for electroconvulsive therapy (ECT) without patients' consent. In the present study we compared the clinical characteristics and one-year outcomes between patients with refusal to undergo ECT and patients without competency for ECT consent.

METHODS

In a retrospective cohort study, 29 patients were treated with ECT without providing consent between 1 January 2006 and 31 August 2010. A surrogate family member gave informed consent for ECT to meet current legal requirements. Patients were assigned to one of two groups: a consent-refusal group comprising patients who refused to give consent for ECT and could clearly say "no" or argue with psychiatric staff about receiving ECT; and a consent-incompetent group comprising patients who were incompetent for consent but underwent ECT passively or reluctantly without argument.

RESULTS

The patients were clinically diagnosed with schizoaffective disorder (n = 6), psychotic disorder (n = 12), bipolar I disorder (n = 8) and major depressive disorder with psychotic features (n = 3). The consent-incompetent patients had longer hospital stays and more recurrence in one year than the consent-refusal patients, which may be because the former group had more psychotic disorders and fewer mood disorders. All patients improved rapidly and efficiently. However, remission was temporal in two-thirds of patients and the rehospitalization rate in one year was 66% (n = 19).

DISCUSSION

ECT can be applied early, emergently and successfully to patients who have a wide range of psychiatric disorders and life-threatening conditions without threat of lawsuits, even during their first hospitalization.

Escitalopram-induced word finding difficulty

Escitalopram is the most selective serotonin reuptake inhibitor used for treatment of major depressive disorder and generalized anxiety disorder. No available report indicating escitalopram may induce word finding difficulty. Here we are presenting a 50-year-old patient who suffered from escitalopram-induced word finding difficulty and the symptom resolved after replacing with bupropion. Carefully monitoring word finding difficulty and speech fluency during antidepressant treatment is important in clinical practice when using selective serotonin reuptake inhibitors, especially escitalopram.

Psychiatric consultation for post-liver-transplantation patients

AIM

This report describes the clinical characteristics of referral inpatients who received liver transplantation and the surgeon's concordance with the psychiatric consultation.

METHODS

During a 4-year period, psychiatric consultation was arranged for 30 post-liver-transplantation inpatients at Kaohsiung Chang Gung Memorial Hospital. A psychiatrist assessed these patients and made psychiatric diagnoses according to the Diagnostic and Statistical Manual, 4th edition. The clinical data were routinely collected via modified MICRO-CARES software. At the end of the 4-year study period, all the medical records of these 30 inpatients were reviewed.

RESULTS

Psychiatric diagnosis was made in 70% of the patients (n = 21) in three major categories, including delirious state (n = 8), depressive disorder (n = 5), and anxiety/dyssomnia (n = 8). All these conditions were improved by psychiatric management. We found that the consultee's concordance with recommended drug prescriptions was high with antidepressants in depressive patients and low with antipsychotics in patients with delirium. Moreover, anxiolytics were frequently prescribed in post-transplant inpatients before psychiatric consultation.

CONCLUSION

These findings suggest that psychiatric consultation is beneficial to inpatients after liver transplantation, especially those with depression and delirium.

Development of a Taiwanese computerized database for psychiatric consultation in a general hospital

OBJECTIVE

The aim of this study was to evaluate the applicability of a modified questionnaire in psychiatric consultation and a new computerized software at one general hospital in Taiwan.

METHOD

The Micro-Cares Clinical Information System for Consultation/Liaison Psychiatry (CISCL), an English language-based patient management application, has multiple clinical variables that were translated into Mandarin Chinese. The Mandarin Chinese version of the Micro-Cares Questionnaire (MCMQ) was further modified after extensive testing and clinical use by two staff psychiatrists and eight senior resident doctors. In addition, the structure of the Mandarin Chinese version of the Micro-Cares CISCL Program (MCMP) was created for direct information entry through a specialized Microsoft Access-based support module.

RESULTS

The MCMQ has been adapted to regular medical practice. Up to 66% of the consultation cases (618/913 patients) were recorded in 2003. Among those registered, 519 (84%) received psychiatric diagnoses. Eight of the 10 participants evaluated agreed that the MCMQ was clinically applicable.

CONCLUSION

MCMQ and MCMP have been routinely applied in the clinical, administrative, research and educational services of our psychiatric consultation.

Psychological impact of severe acute respiratory syndrome on health workers in a tertiary hospital

BACKGROUND

The sudden emergence of severe acute respiratory syndrome (SARS) caused international anxiety owing to its highly contagious and pandemic transmission. Health workers are vulnerable and are at high risk of infection.

AIMS

To assess SARS-related stress and its immediate psychological impact and responses among health workers.

METHOD

Health workers in a tertiary hospital affected by SARS were invited to complete a questionnaire designed to evaluate exposure experience, psychological impact and psychiatric morbidity. The risk and rates of psychiatric morbidity were estimated for exposure experience.

RESULTS

Altogether, 1257 health workers successfully completed the survey. In the initial phase of the outbreak, when the infection was spreading rapidly, feelings of extreme vulnerability, uncertainty and threat to life were perceived, dominated by somatic and cognitive symptoms of anxiety. During the 'repair' phase, when the infection was being brought under control, depression and avoidance were evident. The estimated prevalence of psychiatric morbidity measured by the Chinese Health Questionnaire was about 75%.

CONCLUSIONS

The outbreak of SARS could be regarded as an acute episode of a bio-disaster, leading to a significantly high rate of psychiatric morbidity.

Mindfulness meditation training combined with eye movement desensitization and reprocessing in psychotherapy of an elderly patient

We present our experiences with an elderly patient with depression that was attributed to a surge of physical ailments who also had trauma-derived fear of having to undergo a tracheotomy. He refused pharmacotherapy and was offered intensive training in Mindfulness Meditation (MM) plus Eye Movement Desensitization and Reprocessing (EMDR) therapy during the 2 weeks of hospitalization. This treatment combination had not been used previously. We suggest that EMDR eliminated his fear of surgery, whereas MM relieved his depression and attendant anxiety. However, the two techniques appeared to work synergistically. Following his discharge, he continued to practice MM, which prevented the recurrence of emotional distress, and even helped to reduce its causative physical symptoms. We offer an explanation for the success of our combined treatments and discuss the potential usefulness in specific psychotherapeutic situations. We also propose a place for MM within general geriatric care, and point out the reluctance to consider the therapeutic value of meditation.

Comparison of three methods for identifying medical drug-psychotropic drug interactions

Three methods for examining drug-drug interactions were compared to understand advantages and disadvantages of each: ePocrates; Interact; The Mount Sinai multiple source for the evaluation of drug-drug interactions (MS). ePocrates is a commonly employed software system utilized in a hand held computer, the PalmPilot. Interact is on a CD-ROM, and promoted by the American Psychiatric Association Press. The MS system was developed by the authors and utilizes six separate references sources to ascertain the presence and significance of drug-drug interactions. Commonly prescribed neurology and psychotropic medication interactions were compared using the three systems. ePocrates did not list the significance level of the interaction, e.g., (major, moderate, minor), often did not include a mechanism of action, and several commonly employed medications were not included. It did permit examining several drugs at the same time, and was easily carried on the person of the physician. Interact often contained old references, several drugs were not included, was not adapted to a hand held computer format, and had no update since 1999. The MS system listed level of significance, provided mechanism of action, and advice to the practitioner including recommendations. It is not portable, requiring a laptop or desk top computer or hard copy, and only searches one drug at a time. It is hoped that the advantages of each of these three systems may be incorporated into systems of the future.

Mindfulness meditation in the control of severe headache

In the West, the use of the methods of alternative medicine, including meditation, has been on the rise. In the US, Kabat-Zinn and associates have pioneered the extensive use of mindfulness meditation (MM) for the treatment of people facing pain and illness. Among the essentials of MM is the observation of bodily sensations, including pain. In Taiwan, despite the deep cultural roots of meditation, its therapeutic use has received little attention from institutionalized medicine. We report on the case of a man who was prone to developing severe headaches due to activities requiring extreme concentration. He learned to control his pain and discomfort through mindfulness meditation, although this practice in fact induced headaches initially. It is suggested that training in MM may be a medically superior and cost-effective alternative to pain medication for the control of headaches with no underlying organic causes in highly motivated patients.

Cerebrotendinous xanthomatosis with psychiatric disorders: report of three siblings and literature review

Cerebrotendinous xanthomatosis (CTX), a rare familial lipid metabolic disease inherited via an autosomal recessive trait, is caused by mutations of the sterol 27-hydroxylase gene. Psychiatric disorders may occur in patients with CTX. In Taiwan, Chang et al presented patients with CTX. However, there has not been a case presented about CTX with psychiatric disorders in Taiwan. We present three siblings in one family with CTX combined with moderate mental retardation. One of the siblings had long-term depressed mood, irritability, poor appetite, insomnia, fatigability, and pessimistic thinking and was diagnosed as dysthymic disorder. After 2.5 years of antidepressant treatment at our outpatient clinic, the depressive symptoms of the dysthymic sibling improved greatly. However, the results of the IQ tests of the three siblings did not change after effective treatments for physical manifestations of CTX. In addition, the authors reviewed the literature of CTX combined with psychiatric disorders.

Clinical characteristics of outpatients at a psycho-oncology clinic in a radiation oncology department

BACKGROUND

Psychosocial care in cancer medicine has become increasingly important. The first psychiatric consultation-liaison (C-L) outpatient clinic in Taiwan was established in a department of radiation oncology in a medical center in Oct. 1998.

METHODS

From October 1998 through January 2000, 121 patients were referred for psychosocial evaluation. Six referred patients were excluded because of cerebral complications of malignant disease or coincidental psychiatric disorder. The remaining 115 patients were referred because of psychological problems related to their malignant disease. These patients were divided into 'depression related disorder' and 'anxiety related disorder' groups according to psychiatric standard diagnoses. The records of these referred patients were retrospectively analyzed based on the psychiatric diagnoses.

RESULTS

The outpatient utilization rate for psychiatric consultation escalated from 0% to 5.92% after the C-L clinic was established. Patients with nasopharynx, breast, and head and neck cancer had higher referral, rates (over 10%) than patients with other types of cancer. There were significant differences in major subjective psychiatric problems and psychological reactions between patients with psychiatric diagnosis and those without psychiatric diagnosis. Cancer patients who were diagnosed with 'depression related disorder' visited this clinic more times than those with 'anxiety related disorder'. The former received antidepressant drugs more frequently than the latter. There were also more multiple visits in the former group than the latter group.

CONCLUSION

Locating a C-L clinic in a radiation oncology department improves access to psychiatric evaluation, early detection and continuous intervention can then be offered to cancer patients with anxiety or depression, especially those with 'depression related disorder'.

Development of the Taiwanese Depression Questionnaire

BACKGROUND

Previous studies have shown that different cultures have various modes for emotional expression which suggest that Western scales have certain limitations. The purpose of this study was to develop a culturally relevant depression screening questionnaire: the "Taiwanese Depression Questionnaire" (TDQ) which can be used to conduct epidemiological surveys in Taiwanse society.

METHODS

Based on the results of previous studies and related references, a draft of the TDQ was constructed. After several research group discussions, the first version of a 20-item draft was developed. By purposive sampling, 48 patients, from depressive disorder and anxiety disorder groups of Chang Gung Memorial Hospital's psychiatric clinics, self-rated the draft to test the wording, sequences, and its concurrent validity. After item analysis, a meeting of experts, and draft modification, an 18-item second version of the draft was established. Afterwards, 107 community subjects, recruited from Jenwu Township of Kaohsiung County, were sampled for the receiver operating characteristic (ROC) curve analysis, conventional validity index, and internal consistency of reliability.

RESULTS

The results demonstrate that Cronbach's alpha coefficient (0.90), concurrent validity, and the area under the ROC curves (0.92) are all quite satisfactory. The 18-item TDQ had a sensitivity of 0.89 and a specificity of 0.92 at a cutoff score of 19.

CONCLUSIONS

The TDQ is a culturally relevant questionnaire, which is adaptable for screening depressive people in the local communities.

Tissue distribution, regulation and intracellular localization of murine CD1 molecules

CD1 molecules are MHC-unlinked class Ib molecules consisting of classical (human CD 1a-c) and non-classical subsets (human CD1d and murine CD1). The characterization of non-classical subsets of CD1 is limited due to the lack of reagents. In this study, we have generated two new anti-mouse CD1 monoclonal antibodies, 3H3 and 5C6, by immunization of hamsters with purified CD1 protein. These antibodies recognize CD1-transfected cells and have no reactivity to cells isolated from CD1-/- mice. Both antibodies precipitate the 52 kDa heavy chain and 12 kDa beta2m from thymocytes and splenocytes by radio-immunoprecipitation. Deglycosylation of CD1 reduces molecular mass of the heavy chain by 7.5 kDa, which can be detected by 3H3 but not 5C6. 3H3 and 5C6 detect surface CD1 expression on cells from the thymus, spleen, lymph node and bone marrow, but not on intestinal epithelial cells. Developmentally, CD1 is expressed on thymocytes prior to TCR rearrangement and remains constant throughout thymic development. CD1 is expressed early in the fetal liver (day 14) and remains expressed in hepatocytes postnatally. These data support evidence of a role for CD1 in the selection and/or expansion of NK1- T cells of both thymic origin and extrathymic origin. Unlike classical class I molecules, murine CD1 levels are not affected by IFN-gamma, but like human CD1b can be up-regulated by IL-4 and GM-CSF although only moderately. Similar to human CD1b, murine CD1 is found by immunofluorescence microscopy on the cell surface, and in various intracellular vesicles, including early and late endosomes. Localization in endocytic compartments indicates that murine CD1 may be capable of binding endocytosed antigens.

Impaired NK1+ T cell development and early IL-4 production in CD1-deficient mice

The MHC class lb molecule, CD1, has been conserved throughout mammalian evolution. To assess the function of CD1 in lymphocyte development, we generated mice with targeted disruption of the CD1.1 and CD1.2 genes. CD1-deficient mice have normal numbers of CD4+ and CD8+ T cells but marked reduction in NK1.1-bearing T cells, particularly those with a canonical gene rearrangement of V alpha14-J alpha281. CD1-deficient mice are unable to generate a rapid IL-4 response following systemic T cell activation but can generate effective antigen-specific Th2 responses. Thus, CD1 is required for the development of a specialized subset of T lymphocytes with a monomorphic antigen receptor. The rapid effector cytokine secretion of these T cells suggests that CD1 educates adaptive immune cells to subserve functions of innate immunity.