Downregulation of T cell receptor expression by CD8(+) lymphocytes in kidney allografts.

Allospecific CD8(+) T lymphocytes are an important component of the cellular response in allograft rejection. These cells recognize and engage MHC class I antigens, leading to allospecific cytolytic responses and graft rejection. In mouse kidney allografts that survive to 3 wk after transplantation, we noted that the majority of CD8(+) cells do not express surface alpha/beta T cell receptor alpha/beta(TCR), gamma/deltaTCR, or CD3. However, these CD8(+)TCR- cells did express surface markers characteristic of T cells, including Thy1.2, CD2, and CD5. In addition, the CD8(+)TCR- cells expressed mRNA for TCR Vbeta gene families, and nearly half stained positive for cytoplasmic Vbeta8 protein, suggesting that they are T cells that have downregulated alpha/betaTCR protein expression from their cell surfaces. When these surface TCR- cells were isolated from kidney allografts by flow cytometry and cultured in the presence of either allogeneic or syngeneic stimulators, nearly 100% of cells reacquired normal levels of alpha/betaTCR expression with disproportionate usage of Vbeta8 chains. After recovery of their surface TCR expression, the CD8(+)TCR- population demonstrated strong alloreactivity in culture. These results suggest that the substantial number of CD8(+)TCR- cells found in long-term surviving mouse kidney allografts are alpha/beta-T cells that have downregulated their cell surface expression of TCR. While in other systems this phenotype may identify cells that have engaged antigen, our results indicate that loss of TCR expression by CD8(+) kidney graft-infiltrating cells may not depend on antigen engagement and that elements in the microenvironment of the kidney graft play a key role in this process. Factors that modulate expression of TCR by graft-infiltrating lymphocytes may have an important role in regulating rejection responses.     

Impact of clinical history on fracture detection with radiography

The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information.     

Lymph node infarction – a rare complication associated with disseminated intra vascular coagulation in a case of dengue fever

Background  

Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature.     

Clinical and genetic features of variegate porphyria in a Chinese patient

Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.     

Bladder pheochromocytoma encountered on sonography

Pheochromocytomas of the bladder are rare neoplasms, constituting <0.06% of all vesical tumours. Common presenting features of this tumour include episodes of sweating, hypertension, haematuria and postmicturition syncope. We describe a case of bladder pheochromocytoma in a 66‐year‐old man whose only symptom of macroscopic haematuria was initially assessed with ultrasonography. Clinical presentation highlights the need for a high index of suspicion during sonographic evaluation of bladder neoplasms because such tumours might present without symptoms of adrenergic excess.     

腺病毒载体介导的PML生长抑制因子对前列腺癌细胞生长和致瘤能力的抑制效果

为探讨用腺病毒载体携带ＰＭＬ（ＰｒｏｍｙｅｌｏｃｙｔｉｃＬｅｕｋｅｍｉａ）基因作为前列腺癌基因治疗的可能性，应用重组人携带ＰＭＬ基因腺病毒（ＡｄＰＭＬ）感染培养的前列腺癌细胞，观察表达ＰＭＬ蛋白的癌细胞与对照组癌细胞的体外生长和裸鼠体内致瘤能力变化，对荷瘤裸鼠瘤体周围注射ＡｄＰＭＬ，观察治疗组和对照组肿瘤生长的变化。结果显示，感染ＡｄＰＭＬ的前列腺癌细胞体外生长和裸鼠体内致瘤能力明显下降，荷瘤裸鼠瘤体周围注射ＡｄＰＭＬ后肿瘤生长速度明显减慢。证实了ＰＭＬ是一种生长抑制因子，提示其可能被应用于前列腺癌的基因治疗研究     

Health and Poverty: Global Health Problems and Solutions

Poor outcomes from behavioral treatments of severe obesity have led to a dependence on invasive medical interventions, including surgery for morbidly obese individuals. Improved methods to self-regulate eating will be required to reduce obesity. The use of self-regulation methods for completing physical activity may carry over to increased self-regulation for eating through improved feelings of competence (self-efficacy) and mood. The study recruited women (Mean_age = 43 years) with morbid obesity (Mean_BMI = 44 kg/m²) to participate in 26 weeks of cognitive-behavioral support of physical activity paired with either nutrition education (n = 51) or cognitive-behavioral nutrition (n = 51) methods. Data collected were from 2011 and 2012. Significant improvements in self-regulation for physical activity, self-regulation for eating, overall mood, and self-efficacy for eating, with greater improvement in self-regulation for eating, were observed in the cognitive-behavioral nutrition group. Changes in mood and self-efficacy for eating significantly mediated the relationship between changes in self-regulation for physical activity and self-regulation for eating. When subscales of overall mood and self-efficacy were entered into separate regression equations as mediators, the only significant mediators were vigor, and controlling eating when socially pressured and when increased cues to overeat were present.     

Acute coronary syndromes

The first 150 words of the full text of this article appear below. Key points Coronary artery disease accounts for >30% ofdeaths in Western society. The diagnosis of myocardial infarctionshould be qualified by size, causation and time from occurrence. Mortalityis reduced by immediate or ‘primary’ percutaneouscoronary intervention or thrombolysis within the first 24 hof onset of ST-segment elevation myocardial infarction. Strategiesto reduce platelet activation (glycoprotein IIb/IIIa receptorantagonists, or clopidogrel) are now recommended in the treatmentof high-risk non-ST-segment myocardial infarction/unstable angina. Elevatedserum troponins may be the result of non-ischaemic myocardialdamage, especially in critical illness.