Protective effect of the tunneling nanotube-TNFAIP2/M-sec system on podocyte autophagy in diabetic nephropathy.

Podocyte injury leading to albuminuria is a characteristic feature of diabetic nephropathy (DN). Hyperglycemia and advanced glycation end products (AGEs) are major determinants of DN. However, the underlying mechanisms of podocyte injury remain poorly understood. The cytosolic protein TNFAIP2/M-Sec is required for tunneling nanotubes (TNTs) formation, which are membrane channels that transiently connect cells, allowing organelle transfer. Podocytes express TNFAIP2 and form TNTs, but the potential relevance of the TNFAIP2-TNT system in DN is unknown. We studied TNFAIP2 expression in both human and experimental DN and the renal effect of tnfaip2 deletion in streptozotocin-induced DN. Moreover, we explored the role of the TNFAIP2-TNT system in podocytes exposed to diabetes-related insults. TNFAIP2 was overexpressed by podocytes in both human and experimental DN and exposre of podocytes to high glucose and AGEs induced the TNFAIP2-TNT system. In diabetic mice, tnfaip2 deletion exacerbated albuminuria, renal function loss, podocyte injury, and mesangial expansion. Moreover, blockade of the autophagic flux due to lysosomal dysfunction was observed in diabetes-injured podocytes both in vitro and in vivo and exacerbated by tnfaip2 deletion. TNTs allowed autophagosome and lysosome exchange between podocytes, thereby ameliorating AGE-induced lysosomal dysfunction and apoptosis. This protective effect was abolished by tnfaip2 deletion, TNT inhibition, and donor cell lysosome damage. By contrast, Tnfaip2 overexpression enhanced TNT-mediated transfer and prevented AGE-induced autophagy and lysosome dysfunction and apoptosis. In conclusion, TNFAIP2 plays an important protective role in podocytes in the context of DN by allowing TNT-mediated autophagosome and lysosome exchange and may represent a novel druggable target.Abbreviations: AGEs: advanced glycation end products; AKT1: AKT serine/threonine kinase 1; AO: acridine orange; ALs: autolysosomes; APs: autophagosomes; BM: bone marrow; BSA: bovine serum albumin; CTSD: cathepsin D; DIC: differential interference contrast; DN: diabetic nephropathy; FSGS: focal segmental glomerulosclerosis; HG: high glucose; KO: knockout; LAMP1: lysosomal-associated membrane protein 1; LMP: lysosomal membrane permeabilization; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; PI3K: phosphoinositide 3-kinase; STZ: streptozotocin; TNF: tumor necrosis factor; TNFAIP2: tumor necrosis factor, alpha-induced protein 2; TNTs: tunneling nanotubes; WT: wild type.

Induction of tolerance to an allogeneic skin flap transplant in a preclinical large animal model.

Clinical composite tissue allotransplantation can adequately reconstruct defects that are not possible by other means. However, immunosuppressant toxicity limits the use of these techniques. Clinical attempts to reduce the amount of immunosuppression required by induction of an immunologically permissive state have so far been unsuccessful. The aim of this study was to induce tolerance in a preclinical large animal model. Donor hematopoietic stem cell (HSC) engraftment was induced by T-cell depletion, irradiation, and a short course of cyclosporine administered to the recipient, along with a hematopoietic cell infusion from a single haplotype major histocompatibility complex (MHC) mismatched donor. Skin was then allotransplanted from the donor. Both primarily vascularized skin flaps and secondarily vascularized conventional skin grafts were allotransplanted to investigate if the mode of transplantation affected outcome. Control animals received the skin allotransplants without conditioning. Tolerance was defined as no evidence of rejection at 90 days following transplantation. Conventional skin grafts only achieved prolonged survival (<65 days) in HSC-engrafted animals (P < .01). In contrast, there was indefinite skin flap survival with the achievement of tolerance in HSC-engrafted animals; this was confirmed on histology with donor-specific unresponsiveness on MLR and CML. Furthermore, a conventional skin donor graft subsequently applied to an animal tolerant to a skin flap was not rejected and did not trigger skin flap rejection. To our knowledge, this is the first time skin tolerance has been achieved across a MHC barrier in a large animal model. This is a significant step toward the goal of clinical skin tolerance induction.

Strategic navigation of two-dimensional alley mazes: comparing capuchin monkeys and chimpanzees.

Planning is an important component of cognition that contributes, for example, to efficient movement through space. In the current study we presented novel two-dimensional alley mazes to four chimpanzees and three capuchin monkeys to identify the nature and efficiency of planning in relation to varying task parameters. All the subjects solved more mazes without error than expected by chance, providing compelling evidence that both species planned their choices in some manner. The probability of making a correct choice on mazes designed to be more demanding and presented later in the testing series was higher than on earlier, simpler mazes (chimpanzees), or unchanged (capuchin monkeys), suggesting microdevelopment of strategic choice. Structural properties of the mazes affected both species' choices. Capuchin monkeys were less likely than chimpanzees to take a correct path that initially led away from the goal but that eventually led to the goal. Chimpanzees were more likely to make an error by passing a correct path than by turning onto a wrong path. Chimpanzees and one capuchin made more errors on choices farther in sequence from the goal. Each species corrected errors before running into the end of an alley in approximately 40% of cases. Together, these findings suggest nascent planning abilities in each species, and the prospect for significant development of strategic planning capabilities on tasks presenting multiple simultaneous or sequential spatial relations. The computerized maze paradigm appears well suited to investigate movement planning and spatial perception in human and nonhuman primates alike.

Bilateral focal polymicrogyria in Ehlers-Danlos syndrome.

BACKGROUND: Ehlers-Danlos syndrome (EDS) is a heterogeneous group of generalized connective tissue disorders that has been described in association with epilepsy and cerebral cortical dysplasia, mostly gray matter heterotopias, in 3 reports. However, to our knowledge, association of EDS with another type of cortical cerebral dysplasia, bilateral focal polymicrogyria, has never previously been described. SETTING: Two research-oriented hospitals. PATIENTS: We describe 2 patients with EDS and bilateral polymicrogyria. The first, a 29-year-old black man, presented with EDS of unspecified type, seizures, and bilateral frontocentral and frontoposterior polymicrogyria with hypoplasia of the inferior part of the cerebellar vermis. The second, a 20-year-old woman, had type III EDS, seizures and congenital bilateral perisylvian syndrome with polymicrogyria. CONCLUSIONS: The association of bilateral focal polymicrogyria and EDS in these 2 patients suggests that extracellular matrix proteins implicated in the pathogenesis of EDS, such as collagen and tenascin, may play an important role in cerebral cortical formation and organization. In a clinical setting, the association of EDS with these cortical structural lesions has implications for diagnosis and management.

Strategies used to combine seriated cups by chimpanzees (Pan troglodytes), bonobos (Pan paniscus), and capuchins (Cebus apella).

The authors investigated strategies used to combine seriated cups by apes (Pan troglodytes and P. paniscus) and monkeys (Cebus apella) using a protocol reported in P. M. Greenfield, K. Nelson, and E. Saltzman's (1972) study with children. It was hypothesized that apes would exhibit more hierarchical combinations of cups than monkeys, given apes' language capacity, and that apes would seriate the cups more efficiently than monkeys. As predicted, apes made many structures with the cups using a variety of strategies, and monkeys rarely combined the cups. After a training phase to orient monkeys to the task, the 2 genera did not differ in the strategies used to combine the cups or in efficiency in seriating the cups. Success in this task suggests that sensorimotor versions of hierarchically organized combinatorial activity are well within apes' and monkeys' abilities.

Psychosocial adjustment and mental health two months after coronary artery bypass surgery: a multisystemic analysis of patients' resources.

Resources related to cardiac patients' sense of self, marital quality, and social support were assessed before their first planned bypass surgery to determine their relationship with later psychosocial functioning. Six female and 45 male cardiac patients, 45-70 years old, answered self-report instruments 1 week before and 8-10 weeks after the operation. Regression analyses indicated that only the marital relationship variables made independent contributions to the prediction of functioning. Since self-report measures of resources can be affected by negative affectivity, a second level of analysis predicted change scores while controlling for initial levels of functioning. Marital flexibility and support were found to make an independent contribution to recovery. These results highlight the importance of marital resources in coping with the acute phase following bypass surgery and have implications for prevention and clinical practice.

Vertebral osteomyelitis due to Roseomonas species: case report and review of the evaluation of vertebral osteomyelitis.

We report what we believe is the first case of vertebral osteomyelitis caused by Roseomonas species. The diagnosis of vertebral osteomyelitis can be difficult. The case illustrates the importance of the establishment of an etiologic diagnosis in vertebral osteomyelitis. The features of Roseomonas species and the evaluation of cases of vertebral osteomyelitis are reviewed.

N-terminal degradation of low molecular weight opioid peptides in human cerebrospinal fluid.

Opioid peptides are present in human cerebrospinal fluid (CSF), and their levels are reported to change in some pathologic conditions. However, less is known about their degradation in CSF. In the present study, human CSF was found to contain aminopeptidase activity which hydrolyzed alanyl-, leucyl- and arginyl-naphthylamides in a ratio of 100:28:27. Twelve CSF samples hydrolyzed alanyl-2-naphthylamide and degraded Met5-enkephalin (N-terminal hydrolysis) at rates of 188 +/- 38 and 420 +/- 79 pmol/min/mL respectively. Further, the distribution of alanyl-naphthylamidase activity in individual samples (39-437 pmol/min/mL) was closely correlated with that of Met5-enkephalin degradation (37-833 pmol/min/mL). Both alanyl-naphthylamidase and enkephalin degradation were optimal at pH 7.0 to 7.5 and were inhibited by aminopeptidase inhibitors amastatin (IC50 = 20 nM), bestatin (4-7 microM) and puromycin (30-35 microM). Conversely, degradation was unaffected by inhibitors of neutral endopeptidase (phosphoramidon), carboxypeptidase N (MERGETPA) or angiotensin converting enzyme (captopril). The Km of Met5-enkephalin for the CSF aminopeptidase activity was 201 +/- 19 microM (N = 4). Rates of hydrolysis of the Tyr1-Gly2 bond of larger opioid peptides decreased with increasing peptide length. Pooled, concentrated CSF hydrolyzed Leu5-enkephalin, dynorphin A fragments [1-7], [1-10] and [1-13] and dynorphin A at rates of 2.05 +/- 0.27, 1.27 +/- 0.18, 0.94 +/- 0.06, 0.55 +/- 0.14 and 0.16 +/- 0.03 nmol/min/mL respectively. When analyzed by rocket-immunoelectrophoresis against antisera to aminopeptidase M (EC 3.4.11.2), the concentrated CSF formed an immunoprecipitate which could be stained histochemically for alanyl-naphthylamidase activity. These data are consistent with a significant role for aminopeptidase M activity in the degradation of low molecular weight opioid peptides in human CSF.

Selenium deficiency with total parenteral nutrition: reversal of biochemical and functional abnormalities by selenium supplementation: a case report.

A patient with multiple intestinal fistulae maintained on total parenteral nutrition for 18 months developed low serum selenium. Erythrocyte glutathione peroxidase activity was 6% of normal. Erythrocytes were not able to metabolize H2O2 as well as those from controls, although the hexose monophosphate shunt itself was intact. Granulocytes from this patient had 15% of the erythrocyte glutathione peroxidase activity found in normals. Patient granulocytes were not able to metabolize H2O2 as well as controls, although the hexose monophosphate shunt was intact. Erythrocyte glutathione peroxidase-deficient granulocytes incubated with a respiratory burst stimulant, phorbol myristate acetate, had only 60% of the hexose monophosphate shunt activity present in control granulocytes. These abnormalities were reversed with selenium supplementation. Bacterial killing of Staphylococcus aureus 502A and cardiac function were not affected by selenium deficiency. Thus, selenium deficiency resulted in biochemical and functional abnormalities of erythrocytes and granulocytes. These abnormalities were reversed with selenium supplementation.

Epinephrine induced myocardial necrosis: effects of aminophylline and adrenergic blockade.

The pathogenesis of myocardial necrosis produced in the albino rat by a single large dose of the potent alpha and beta adrenergic agonist epinephrine was investigated. In confirmation and extension of earlier observations with the alpha adrenergic antagonist tolazoline, it was found that alpha adrenergic blockade with phenoxybenzamine or beta adrenergic blockade with propranolol only partially attenuated the cardiotoxic effect of epinephrine while complete prevention of myocardial injury was achieved with the combined use of the two antagonists. In the presence of alpha adrenergic blockade alone, phosphodiesterase inhibition (aminophylline) caused a dramatic increase of epinephrine cardiotoxicity, demonstrating the importance of unopposed beta adrenergic activation. These results are consistent with the assumption that, in the rat, a cardiotoxic dose of epinephrine produces powerful alpha adrenergic activation which overshadows the effects of the beta adrenergic component of this catecholamine. It is concluded that in epinephrine induced myocardial necrosis, excessive alpha-adrenergic receptor activation in the cardiovascular system is clearly dominant in the initial phases. However, the contribution of the beta-adrenergic component of this catecholamine is of considerable importance for the eventual full development of the injury.

Chronic intestinal pseudo-obstruction.

Intestinal pseudo-obstruction (IP) is an uncommon disorder of gut motility which must be differentiated from mechanical intestinal obstruction. We have seen 11 such patients over the last 5 years. Characteristic symptoms, shared by mechanical obstruction, include abdominal distention and pain, nausea, and vomiting. Radiologic studies reveal dilated loops of bowel with air fluid levels. In most patients a major differentiating feature from obstruction may be the presence of diarrhea rather than obstipation. Steatorrhea is secondary to an overgrowth of anaerobic bacteria in the motionless dilated loops of bowel. IP has been associated with various disorders: in our series two patients had scleroderma, one multiple small bowel diverticula, one systemic amyloidosis, one celiac disease, and one spinal cord injury; in only two patients was the disorder considered "idiopathic." Three patients had previously undergone a jejuno--ileal bypass for morbid obesity. During the acute episode, the patients were treated symptomatically with decompression by nasogastric or rectal tube with fluid and electrolyte replacement. Malabsorption treated with broad spectrum antibiotics reversing the steatorrhea but not episodes of pseudo-obstruction. Magnesium deficiency was present in seven patients and its correction resulted in amelioration of the symptom complex. In two patients episodes of pseudo-obstruction were markedly reduced by metoclopramide which was not effective in two others.

Anorectal manometry in the diagnosis of Hirschsprung's disease in adults.

Anorectal manometry is a useful tool in evaluating the cause of chronic constipation and is reliable in the diagnosis of Hirschsprung's disease. Two adult patients ages 35 and 69 with constipation since birth underwent anorectal manometry. Balloons positioned at the internal and external anal sphincters were connected to pressure transducers and their responses to a distention of rectal balloon were recorded. Both patients demonstrated failure of relaxation of the internal anal sphincter which is characteristic of Hirschsprung's disease. This diagnosis was confirmed at surgery by histologic examination failing to show ganglia. Anorectal manometry is a useful adjunct in the differential diagnosis of adult patients with megacolon.

Acquired hypomegakaryocytic thrombocytopenic purpura. Occurrence in a patient with absent thrombopoietic stimulating factor.

A 49-year-old woman had purpura and thrombocytopenia not associated with drugs or identifiable underlying disease. The platelet survival was normal and the marrow showed a sharp reduction in megakaryocytes with preservation of other cell lines. There was no response to steroids or infusion of fresh frozen plasma. Lithium carbonate therapy similarly had no effect. Thrombopoietic activity was absent in serum and urine samples. Erythropoietin activity was normal. In vitro formation of granulocyte-macrophage colonies in soft agar was normal. The case represents a unique incidence of selective megakaryocytic hypoplasia, though to result from a failure in stem cell differentiation.

Hepatic infarction in ulcerative colitis during pregnancy.

Acute hepatic failure developed at the time of parturition in a 27-yr-old woman. Liver biopsy demonstrated disseminated hepatic infarctions which were confined to the distal segments of the hepatic microcirculatory units. This episode of hepatic infarction was followed by persistent fever and cutaneous vasculitis, which resolved on prednisone therapy. The diagnosis of ulcerative colitis was made 5 mo after recovery from severe hepatic failure.

Acute calcific quadriceps tendinitis.

Acute calcific quadriceps tendinitis can be the cause of acute periarthritis of the knee. Physical examination can detect cellulitis and a tender tendon sheath. Lateral roentgenograms of soft tissues show thickening of the tendon and sometimes small flecks of amorphous calcification within the body of the tendon near the attachment. Although hyperostosis of the patella near the tendon attachment is often present, it is well defined ossification and not associated with the acute symptoms. The amorphous calcium deposits quickly disappear during the acute tendinitis and are not detected on follow-up radiologic examination.