The limited memory of value following value directed encoding

Items associated with higher values during encoding are later recognized and recalled better than are lower valued items. During recall paradigms, these value directed encoding (VDE) effects heavily depend upon learned strategies acquired during repeated testing with earnings feedback. However, because VDE effects also occur in single test recognition designs, precluding such learning, it has been suggested that high value may automatically induce good encoding. We tested this by manipulating encoding instructions (Experiments 1a and 1b) and manipulating concurrent levels of processing (LOP) requirements during encoding (Experiment 2a and 2b). Two main findings emerged. First, subject initiated strategies played a dominant role in VDE effects with little evidence for automaticity. This was demonstrated in Experiment 1 by a more than three-fold increase in the VDE recognition effect when instructions specifically encouraged selective elaboration of high-value items. It was also shown by the complete elimination of VDE recognition effects in Experiment 2 when LOP tasks were concurrently performed during encoding. Critically, the blocking of VDE effects occurred even though a catch trial procedure verified that value was being processed during encoding and remained even when subjects had unlimited time to process the materials during encoding. Second, the data showed, for the first time, that when subjects attempted to specify the value of recognized items, they heavily depended upon a recognition heuristic in which increases in recognition strength, even when nondiagnostic, were inferred to reflect high encoding value. The tendency for subjects to conflate recognition strength and value may have important implications for behavioral economics.

NTS Catecholamine Neurons Mediate Hypoglycemic Hunger via Medial Hypothalamic Feeding Pathways

Glucose is the essential energy source for the brain, whose deficit, triggered by energy deprivation or therapeutic agents, can be fatal. Increased appetite is the key behavioral defense against hypoglycemia; however, the central pathways involved are not well understood. Here, we describe a glucoprivic feeding pathway by tyrosine hydroxylase (TH)-expressing neurons from nucleus of solitary tract (NTS), which project densely to the hypothalamus and elicit feeding through bidirectional adrenergic modulation of agouti-related peptide (AgRP)- and proopiomelanocortin (POMC)-expressing neurons. Acute chemogenetic inhibition of arcuate nucleus (ARC)-projecting NTS^TH neurons or their target, AgRP neurons, impaired glucoprivic feeding induced by 2-Deoxy-D-glucose (2DG) injection. Neuroanatomical tracing results suggested that ARC-projecting orexigenic NTS^TH neurons are largely distinct from neighboring catecholamine neurons projecting to parabrachial nucleus (PBN) that promotes satiety. Collectively, we describe a circuit organization in which an ascending pathway from brainstem stimulates appetite through key hunger neurons in the hypothalamus in response to hypoglycemia.

MCH Neuron Activity Is Sufficient for Reward and Reinforces Feeding

BACKGROUND

Melanin-concentrating hormone (MCH)-expressing neurons have been implicated in regulation of energy homeostasis and reward, yet the role of their electrical activity in short-term appetite and reward modulation has not been fully understood.

OBJECTIVES

We investigated short-term behavioral and physiological effects of MCH neuron activity manipulations.

METHODS

We used optogenetic and chemogenetic approaches in Pmch-cre transgenic mice to acutely stimulate/inhibit MCH neuronal activity while probing feeding, locomotor activity, anxiety-like behaviors, glucose homeostasis, and reward.

RESULTS

MCH neuron activity is neither required nor sufficient for short-term appetite unless stimulation is temporally paired with consumption. MCH neuronal activation does not affect short-term locomotor activity, but inhibition improves glucose tolerance and is mildly anxiolytic. Finally, using two different operant tasks, we showed that activation of MCH neurons alone is sufficient to induce reward.

CONCLUSIONS

Our results confirm diverse behavioral/physiological functions of MCH neurons and suggest a direct role in reward function.

Reduction in tumour cell invasion by pigment epithelium-derived factor is mediated by membrane type-1 matrix metalloproteinase downregulation

Prostate cancer and breast cancer are major killers among males and females respectively. In this study, pigment epithelium-derived factor (PEDF) was examined for its effect on commonly used human prostate cancer and human breast cancer cell lines. PEDF increased adhesion of cells to collagen-I, with decreased expression of phosphorylated focal adhesion kinase (p-Fak) consistent between the two cell types. Invasion of both tumour cell types through collagen-I was also reduced by PEDF, with decreased expression of membrane type-1 matrix metalloproteinase (MT1-MMP). These results were confirmed with specific antibodies to MT-MMP1. This study provides some vital clues as to which molecular players are perturbed by PEDF treatment of human prostate and breast cancer cells, raising hope that PEDF can in future be trialled against these major cancers in attempts to procure safer yet effective therapies for cancer.

Simultaneous occurrence of synchronous and metachronous tumors with gastrointestinal stromal tumors

OBJECTIVE

To examine the frequency and clinicopathological features of synchronous and metachronous tumors which occur simultaneously with gastrointestinal stromal tumors (GIST).

METHODS

Clinical and pathologic records of 78 patients diagnosed with primary GIST and treated at our institution between 1997 and 2009 were reviewed.

RESULTS

GIST occurred simultaneously with other primary GI malignancies in 16.1 % (n = 13) of all patients with GIST. Of the simultaneous secondary tumors, 69.2 % (n = 9) were gastrointestinal tumors, and the remaining were biliary system and breast tumors. GIST most frequently had gastric localization (n = 6, 46.1%).

CONCLUSION

Although GIST are uncommon neoplasms, their synchronous and metachronous coexistence with other tumors is rather frequent, mostly as incidental tumors accompanying a gastrointestinal neoplasm. Therefore, during surgery on cases with gastrointestinal neoplasms, the surgeon needs to be careful about a synchronous GIST. At the same time, more detailed studies are needed about the carcinogenesis of dual tumors coexisting with GIST (Tab. 1, Ref. 14).

Significance of nm23 Immunoexpression in the Prognosis of Renal Cell Carcinoma

Non-metastatic gene 23 (nm23) is a metastasis suppressor gene that is expressed in all tissues and decreased nm23 expression may be linked to poor prognosis. By immunohistochemical staining of nm23 protein antibodies this study examined the prognostic value of nm23 protein expression in 54 renal cell carcinoma (RCC) patients and analysed its relationship with tumour, node, metastases (TNM) surgical stage, Fuhrman nuclear grade, lymph node involvement and survival. Of the 54 RCC cases studied, 11 (20.4%) showed positive lymph node involvement while 43 (79.6%) were lymph node negative. There was no difference in nm23 protein expression between cases with and without lymph node involvement. In addition, nm23 protein expression was not related to TNM stage, Fuhrman nuclear grade or survival. More extensive studies are required to understand the effect of nm23 protein expression on the biological behaviour of RCC.

An Unusual Cause of Ureteral Obstruction in a Renal Transplant Recipient: Ureteric Aspergilloma

Mycotic infections in various organ transplant recipients represent severe and often fatal complications. Aspergillosis isolated from the urinary tract occurs quite infrequently in renal transplant recipients. Besides, fungus balls are rare causes of ureteral obstruction. We report a 51-year-old patient with the diagnosis of ureteral obstruction caused by aspergillosis in the early post-renal transplant period, who unfortunately died with the clinical picture of disseminated infection and its complications.

A family with IgA nephropathy and hereditary lymphoedema praecox

Immunoglobulin A (IgA) nephropathy is the most common primary glomerulonephritis worldwide. The pathogenesis is still unknown and treatment has not yet been established. Rarely it can be associated with other disorders. Its association with hereditary lymphoedema is not reported before. We report four patients, a 60-year-old father, his two sons and his daughter, with hereditary lymphoedema. The family had nine members and in four of them lymphoedema was evident. The other members had neither lymphoedema nor IgA nephropathy. This is the first report of IgA nephropathy in association with hereditary lymphoedema.

High expression of multidrug resistance-1 (MDR-1) and its relationship with multiple prognostic factors in gastric carcinomas in patients in Turkey

Drug resistance remains a major problem in the treatment of gastric cancer. In Turkey, gastric carcinoma is the second most common cancer and, because the rate of early diagnosis is low, chemotherapy plays an important role in the treatment of the disease. We aimed to investigate expression of the multidrug resistance-1 gene (MDR-1) and its relationship with multiple prognostic factors in gastric cancers. Between 1996 and 1998, a total of 55 patients (37 men and 19 women; median age 55 years) were studied. Sections from specimens of gastric carcinomas were immunohistochemically stained to detect P-glycoprotein (which is associated with MDR-1 expression). We found MDR-1 expression in 48 (87%) of the patients. None of the multiple prognostic factors, including histological type of tumour, correlated with expression of MDR-1. Patients who had low MDR-1 expression had better survival. We conclude that the expression of MDR-1 in gastric cancer is high in Turkey, and this may be related to poor prognosis.