Dense core vesicle proteins IA-2 and IA-2beta: metabolic alterations in double knockout mice

IA-2 and IA-2beta are members of the transmembrane protein tyrosine phosphatase family located in dense core vesicles of neuroendocrine cells, including the beta-cells of pancreatic islets. In the present study, by mating C57BL/6Nci IA-2(+/-) with IA-2beta(+/-) mice, we generated double knockout mice (IA-2(-/-)/IA-2beta(-/-)) to study the effect of the combined deletion of these two proteins on insulin secretion and blood glucose levels. The double knockout mice appeared healthy at birth and showed normal growth and development. Histological examination and immunostaining for insulin, glucagon, somatostatin, and pancreatic polypeptide revealed no difference between the double knockout and wild-type mice. Nonfasting blood glucose and insulin levels also were within the normal range. However, compared with the wild-type mice, the double knockout mice showed glucose intolerance and an absent first-phase insulin release curve. No evidence of insulin resistance was observed nor were there alterations in fasting blood glucose, insulin, or leptin levels in the double knockout mice maintained on a high-fat diet compared with the wild-type mice maintained on the same diet. In addition, to determine whether the combined deletion of IA-2 and IA-2beta played any role in the development of diabetes in NOD mice, we generated double knockout mice on the NOD/LtJ background. The incidence of diabetes in these mice was not significantly different than that in the wild-type mice. Taken together, our experiments show that the dense core vesicle proteins IA-2 and IA-2beta, alone or in combination, are involved in insulin secretion, but neither alone nor in combination are they required for the development of diabetes in NOD mice.     

Inositol (1,4,5)-trisphosphate dynamics and intracellular calcium oscillations in pancreatic beta-cells

Glucose-stimulated insulin secretion is associated with transients of intracellular calcium concentration ([Ca2+]i) in the pancreatic beta-cell. We tested the hypothesis that inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] [Ca2+]i release is incorporated in glucose-induced [Ca2+]i oscillations in mouse islets and MIN6 cells. We found that depletion of intracellular Ca2+ stores with thapsigargin increased the oscillation frequency by twofold and inhibited the slow recovery phase of [Ca2+]i oscillations. We employed a pleckstrin homology domain-containing fluorescent biosensor, phospholipase C partial differential pleckstrin homology domain-enhanced green fluorescent protein, to visualize Ins(1,4,5)P3 dynamics in insulin-secreting MIN6 cells and mouse islets in real time using a video-rate confocal system. In both types of cells, stimulation with carbamoylcholine (CCh) and depolarization with KCl results in an increase in Ins(1,4,5)P3 accumulation in the cytoplasm. When stimulated with glucose, the Ins(1,4,5)P3 concentration in the cytoplasm oscillates in parallel with oscillations of [Ca2+]i. Maximal accumulation of Ins(1,4,5)P3 in these oscillations coincides with the peak of [Ca2+]i and tracks changes in frequencies induced by the voltage-gated K+ channel blockade. We show that Ins(1,4,5)P3 release in insulin-secreting cells can be stimulated by depolarization-induced Ca2+ flux. We conclude that Ins(1,4,5)P3 concentration oscillates in parallel with [Ca2+]i in response to glucose stimulation, but it is not the driving force for [Ca2+]i oscillations.     

Small cell carcinoma of epididymis: multimodal therapy

Extrapulmonary small cell carcinoma is an infrequent tumor that can occur in various organs. Although a few sporadic reports about extrapulmonary small cell carcinoma have been published, much remains to be uncovered about the clinical features, optimal treatment, and natural history. We present a case of small cell carcinoma of the epididymis with retroperitoneal recurrence, an exceedingly rare tumor with behavior and treatment not well characterized. Multimodal therapy with chemotherapy and retroperitoneal lymph node dissection was necessary to manage this aggressive disease.     

Desmoplastic nested spindle cell tumor of liver: report of four cases of a proposed new entity

We describe a distinctive tumor of the liver in four children composed of nested spindled and epithelioid cells with extensive desmoplasia that we have termed "desmoplastic nested spindle cell tumor of the liver." All four patients were previously healthy. One patient had a presumptive diagnosis of hepatic hemangioma 11 years prior to presentation. Grossly, the tumors were well circumscribed, lobular white masses, ranging from 2.8 to 15 cm in diameter. These tumors were characterized by the presence of cohesive nests of plump, bland spindle cells arranged in short fascicles with an accompanying desmoplastic stroma. Epithelioid areas ranging from palisading epithelioid cells at the periphery of some nests to pseudoglandular and polygonal cells with intercellular bridges were invariably present. Mitotic activity was low. Calcification and ossification were present. Non-neoplastic bile ducts and hepatic elements were seen both within and surrounding the tumor cell nests. Each tumor displayed cytoplasmic reactivity for vimentin, pan-cytokeratin, CD57, and nuclear staining for WT1. Neuroendocrine markers were negative. Ultrastructurally, the tumor cells showed focally well-developed cell junctions, basal lamina, and few cytoplasmic organelles. All tumors were confined to the liver and were resected without complication. Two patients received postoperative adjuvant therapy for presumed hepatoblastoma. The patients are doing well without recurrence at 7.5 years, 7 years, 5 years, and 8 months post-surgery. The morphologic appearance and immunohistochemical profile of these lesions are unique in our experience and represent a new category of pediatric liver tumor.     

Using pharmacy data to identify those with chronic conditions in Emilia Romagna, Italy

BACKGROUND AND OBJECTIVES: Automated pharmacy data have been used to develop a measure of chronic disease status in the general population. The objectives of this project were to refine and apply a model of chronic disease identification using Italian automated pharmacy data; to describe how this model may identify patterns of morbidity in Emilia Romagna, a large Italian region; and to compare estimated prevalence rates using pharmacy data with those available from a 2000 Emilia Romagna disease surveillance study. METHODS: Using the Chronic Disease Score, a list of chronic conditions related to the consumption of drugs under the Italian pharmaceutical dispensing system was created. Clinical review identified medication classes within the Italian National Therapeutic Formulary that were linked to the management of each chronic condition. Algorithms were then tested on pharmaceutical claims data from Emilia Romagna for 2001 to verify the applicability of the classification scheme. RESULTS: Thirty-one chronic condition drug groups (CCDGs) were identified. Applying the model to the pharmacy data, approximately 1.5 million individuals (37.1%) of the population were identified as having one or more of the 31 CCDGs. The 31 CCDGs accounted for 77% (E556 million) of 2001 pharmaceutical expenditures. Cardiovascular diseases, rheumatological conditions, chronic respiratory illness, gastrointestinal diseases and psychiatric diseases were the most frequent chronic conditions. External validation comparing rates of the diseases found through using pharmacy data with those of a 2000 Emilia Romagna disease surveillance study showed similar prevalence of illness. CONCLUSIONS: Using Italian automated pharmacy data, a measure of population-based chronic disease status was developed. Applying the model to pharmaceutical claims from Emilia Romagna 2001, a large proportion of the population was identified as having chronic conditions. Pharmacy data may be a valuable alternative to survey data to assess the extent to which large populations are affected by chronic conditions.     

Managing disruptive behaviors with neuroleptics: treatment options for older adults in nursing homes

Disruptive behaviors are frequent among elderly individuals in long-term care centers. Neuroleptics remain the most common pharmacological treatment for controlling these challenging behavioral manifestations. However, their effectiveness is a subject of controversy and it is unclear what specific behaviors are more likely to be managed with neuroleptic medications. The objective of this study was to identify the types of disruptive behaviors for which neuroleptics are given to elderly individuals in long-term care facilities and determine if the frequency of these behaviors increases the risk of being prescribed neuroleptics. A cross-sectional study was conducted with 2,332 participants ages 65 or older living in 28 long-term care facilities. Among them, 27.8% had taken at least one neuroleptic drug in the prior week. The administration of neuroleptics was not linked to the presence of any one specific disruptive behavior. However, a significant finding was that the greater the frequency of disruptive behavior exhibited by an elderly individual, the greater the risk of them being administered a neuroleptic medication. A multi-dimensional approach to the assessment of disruptive behaviors is recommended to facilitate the identification of the underlying causes of those behaviors. Accordingly, it is suggested that non-pharmacological treatment plans be adapted to each situation and then implemented to potentially reduce the use of neuroleptics.     

The cartilage thickness distribution in the tibiofemoral joint and its correlation with cartilage-to-cartilage contact

OBJECTIVE: The objective of this study was to investigate whether regions of cartilage in the tibiofemoral joint where cartilage-to-cartilage contact occurred was thicker than other regions. DESIGN: In vivo human subjects. BACKGROUND: The thickness of the cartilage in the knee has been investigated in various studies. However, the factors that influence the thickness distribution within the joint remain unclear. METHODS: Six healthy living knees (5 male, 1 female, average age = 27) were scanned using magnetic resonance imaging. Three-dimensional models of the tibial and femoral cartilage layers were created. The cartilage thickness distribution was compared between regions where cartilage-to-cartilage contact was observed during in vivo weightbearing flexion and regions with no contact. RESULTS: The regions with cartilage-to-cartilage contact were significantly thicker than the regions without cartilage-to-cartilage contact (P < 0.05). On the medial condyle, the cartilage-to-cartilage contact regions were up to 40% thicker than regions with no contact. On the lateral femoral condyle, the maximum difference between these regions was 20%. On the tibial plateau, the maximal differences between regions with and without cartilage-to-cartilage contact were found to be 40% on the medial side and 50% on the lateral side. CONCLUSIONS: The data suggested that in normal knees, the cartilage was thicker in regions where cartilage-to-cartilage contact was present. Future studies should investigate the effects of in vivo loading on cartilage maintenance and growth. Relevance Injuries that alter knee kinematics might load regions of the joint where the cartilage is thinner. This might alter the stress distributions within the cartilage.