Association of CD26 with CD45RA outside lipid rafts attenuates cord blood T-cell activation

CD26 is a T-cell activation antigen that contains dipeptidyl peptidase IV activity and binds adenosine deaminase. Recent work showed that specialized membrane microdomains, also known as lipid rafts, play a key role in T-cell signaling. In this study, we investigate the role of CD26 in cord blood T-cell activation and signal transduction. We demonstrated that different expression levels of CD26 were observed between cord blood T cells (CBTCs) and peripheral blood T cells (PBTCs) and that CD26(+)CD45RA(+) CBTCs were different compared with CD26(+)CD45RA(+) PBTCs. Moreover, the comitogenic effect of CD26 was not as pronounced in CBTCs as in PBTCs. We also showed that CD26 cross-linking induced less phosphorylation of T-cell receptor-signaling molecules, lymphoid T-cell protein tyrosine kinase (Lck), zeta-associated protein 70 (ZAP-70), T-cell receptor zeta (TCRzeta), and linker for activator of T cells (LAT) in CBTCs than in PBTCs. Furthermore, CD26 molecules associated with CD45RA molecules outside lipid rafts in CBTCs. Our results suggest that strong physical linkage of CD26 with CD45RA outside lipid rafts may be responsible for the attenuation of T-cell activation signaling through CD26, which may be responsible for immature immune response and the low incidence of severe graft-versus-host disease in cord blood transplantation.     

Rapid identification of Candida albicans and its related species Candida stellatoidea and Candida dubliniensis by a single PCR amplification using primers specific for the repetitive sequence (RPS) of Candida albicans

BACKGROUND: Candidiasis is caused by several Candida species, of which Candida stellatoidea and C. dubliniensis are phenotypically close to C. albicans. Although current molecular biology-based techniques can distinguish between C. albicans and C. dubliniensis, a convenient tool that can distinguish C. stellatoidea from C. albicans has not yet been developed. OBJECTIVE: To develop a system that can simply, rapidly and specifically distinguish C. albicans from the related Candida species C. stellatoidea and C. dubliniensis. MATERIALS: Genomic DNAs were purified from various yeast species and amplified by primers specific for the repetitive sequence (RPS) of C. albicans. The PCR products were purified and sequenced in order to test the specificity of the PCR amplification. RESULTS: The PCR primers only amplified several products from C. albicans, C. stellatoidea and C. dubliniensis. Sequence analysis of the products revealed that C. stellatoidea and C. dubliniensis both had RPSs including alt repeats, similar to C. albicans. After the PCR amplification, each of the three Candida species showed a unique amplification profile. Furthermore, RFLP analysis of the PCR products using EcoRI and ClaI produced species-specific restriction profiles. CONCLUSIONS: This PCR-based technique targeting the alt repeats in the RPS is useful as a tool for the rapid identification and distinction of C. albicans, C. stellatoidea and C. dubliniensis.     

Visual field defects after macular hole surgery with indocyanine green-assisted internal limiting membrane peeling

PURPOSE: To report visual field defects after macular hole surgery with indocyanine green (ICG)-assisted internal limiting membrane (ILM) peeling. DESIGN: Interventional consecutive case series. METHODS: A retrospective review of 140 eyes with macular hole after vitrectomy with ILM peeling. The group with 0.25% of ICG for ILM peeling consisted of 96 eyes. The group without ICG consisted of 44 eyes. RESULTS: Nasal visual field defects occurred in 11 eyes, temporal visual field defects in seven eyes, and concentric visual field defects in one eye. In the group with ICG, nasal visual field defects were far higher in the left eye than in the right eye. CONCLUSIONS: We speculate that the postoperative nasal visual field defects were caused by the enhanced toxicity of ICG resulting from the exposure to illumination.     

Study of bronchus-associated lymphoid tissue in patients with diffuse panbronchiolitis.

Bronchus-associated lymphoid tissue (BALT) is thought to affect local immunologic defense mechanisms. Studies of BALT, however, have mainly been focused on animals, and information detailing the BALT structure and functions in humans is scanty. Therefore, the purpose of this study is to clarify BALT morphology and immunologic findings in patients with diffuse panbronchiolitis (DPB) and compare them with BALT findings in animals. Thus, in 17 patients diagnosed with DPB, open-lung biopsy specimens were reviewed, and lymphoid follicles with a lymphoepithelium that was determined as BALT were identified in 12 patients. BALT was found mostly at bifurcations from nonrespiratory bronchioles to respiratory bronchioles. This lymphoepithelium was devoid of cilia and was diffusely infiltrated with CD4-positive (helper/inducer) T cells. The majority of T cells were confined to the parafollicular area with a predominance of helper T cells. Also, a few high endothelial venules were recognized in the parafollicular area. Further, in a follicular area situated in the center of the BALT, a number of sigM-positive cells were found to be heavily distributed, suggesting that this follicular area has the characteristics of a B cell zone equivalent to a germinal center of the peripheral lymph nodes. These observations are comparable with BALT findings in animals and suggest that BALT is at least partially related to the local immune response.     

Near-fatal cerebral edema associated with adenovirus type 2 infection in a previously healthy infant

We report a near-fatal case of cerebral edema associated with adenovirus type 2 infection in a previously healthy 19-month-old boy. After 3 to 4 d of high fever and a series of seizures, he developed persistent loss of consciousness and irreversible respiratory arrest. Adenovirus type 2 infection was diagnosed by virus isolation from his stool and serology.     

Left ventricular oozing rupture following acute myocardial infarction

We describe the case of an 85-year-old woman in whom pericardiocentesis, prolonged bed rest and blood pressure control were performed without surgery to successfully treat an oozing-type myocardial rupture due to myocardial infarction.     

Extended resection of primary lung cancer directly invading the liver

Abstract:   A 61-year-old woman presented with chest pain. Chest CT revealed a mass of 6 cm diameter in the right lower lobe. Bronchoscopic biopsy showed squamous cell carcinoma. Video-assisted thoracotomy revealed that the main tumour was directly invading the liver through the diaphragm. To alleviate local symptoms and for possible cure with adjuvant chemotherapy and radiotherapy, standard right lower lobectomy and mediastinal dissection were carried out, followed by combined resection of the diaphragm and posterior superior segmentectomy of the liver. Eleven months postoperatively, the patient was alive but had a metastatic lesion in the other lobe of the liver which reduced in size following chemotherapy.     

Reduced Insulin Sensitivity Is Related to Less Endogenous Dopamine at D2/3 Receptors in the Ventral Striatum of Healthy Nonobese Humans

Background:

Food addiction is a debated topic in neuroscience. Evidence suggests diabetes is related to reduced basal dopamine levels in the nucleus accumbens, similar to persons with drug addiction. It is unknown whether insulin sensitivity is related to endogenous dopamine levels in the ventral striatum of humans. We examined this using the agonist dopamine D_2/3 receptor radiotracer [¹¹C]-(+)-PHNO and an acute dopamine depletion challenge. In a separate sample of healthy persons, we examined whether dopamine depletion could alter insulin sensitivity.

Methods:

Insulin sensitivity was estimated for each subject from fasting plasma glucose and insulin using the Homeostasis Model Assessment II. Eleven healthy nonobese and nondiabetic persons (3 female) provided a baseline [¹¹C]-(+)-PHNO scan, 9 of which provided a scan under dopamine depletion, allowing estimates of endogenous dopamine at dopamine D_2/3 receptor. Dopamine depletion was achieved via alpha-methyl-para-tyrosine (64mg/kg, P.O.). In 25 healthy persons (9 female), fasting plasma and glucose was acquired before and after dopamine depletion.

Results:

Endogenous dopamine at ventral striatum dopamine D_2/3 receptor was positively correlated with insulin sensitivity (r(7)=.84, P=.005) and negatively correlated with insulin levels (r(7)=-.85, P=.004). Glucose levels were not correlated with endogenous dopamine at ventral striatum dopamine D_2/3 receptor (r(7)=-.49, P=.18). Consistently, acute dopamine depletion in healthy persons significantly decreased insulin sensitivity (t(24)=2.82, P=.01), increased insulin levels (t(24)=-2.62, P=.01), and did not change glucose levels (t(24)=-0.93, P=.36).

Conclusion:

In healthy individuals, diminished insulin sensitivity is related to less endogenous dopamine at dopamine D_2/3 receptor in the ventral striatum. Moreover, acute dopamine depletion reduces insulin sensitivity. These findings may have important implications for neuropsychiatric populations with metabolic abnormalities.