O-GlcNAc expression in developing and ageing mouse brain.

In order to understand whether there is a specific role for the posttranslational N-acetylglucosamine modification linked O-glycosidically (O-GlcNAc) to serine and threonine residues of proteins during development and/or ageing of the brain, we investigated the O-GlcNAc expression of early postnatal cerebellar neurons as well as of mouse brain of different ages. In all cells either in culture or of cryosections mainly the nuclei and nuclear membranes were stained with an O-GlcNAc specific monoclonal antibody. In cerebellar neurons in culture the level of expression could be manipulated by directly interfering with either the biosynthesis of GlcNAc or the removal of O-GlcNAc from proteins confirming the dynamic nature of this protein modification. O-GlcNAc was ubiquitously expressed in mouse brains from embryonic day 10 until late adulthood with some variations in expression strength from cell to cell. In addition, no significant difference in O-GlcNAc expression of subcellular fractions from brains of mice which age at an accelerated rate could be detected compared to normal mice. Taken together these observations support the view that the O-GlcNAc modification has important functional roles for physiological processes of neural cell throughout development, in adulthood and ageing.

Fluoxetine for depression in diabetes: a randomized double-blind placebo-controlled trial.

OBJECTIVE: Depression is prevalent in patients with diabetes. It is associated with poor glycemic control and is linked to an increased risk for diabetic complications. In this study, we assessed the efficacy of fluoxetine for depression in patients with diabetes. RESEARCH DESIGN AND METHODS: Sixty patients with diabetes (type 1, n = 26; type 2, n = 34) and major depressive disorder entered an 8-week randomized placebo-controlled double-blind trial. Patients were given daily doses of fluoxetine (up to 40 mg/day). The Beck Depression Inventory (BDI) and Hamilton Rating Scale for Depression (HAMD) were used to measure the severity of depression and to determine the percentage of patients who achieved substantial improvement or complete remission. GHb levels were obtained to monitor glycemic control. RESULTS: Reduction in depression symptoms was significantly greater in patients treated with fluoxetine compared with those receiving placebo (BDI, -14.0 vs. -8.8, P = 0.03; HAMD, -10.7 vs. -5.2, P = 0.01). The percentage of patients achieving a significant improvement in depression per the BDI was also higher in the fluoxetine group (66.7 vs. 37.0%, P = 0.03). Additionally, trends toward a greater rate of depression remission (48.1 vs. 25.9%, P = 0.09 per the HAMD) and greater reduction in GHb (-0.40 vs. -0.07%, P = 0.13) were observed in the fluoxetine group. CONCLUSIONS: Fluoxetine effectively reduces the severity of depression in diabetic patients. Our study demonstrated that after only 8 weeks, this treatment also produced a trend toward better glycemic control.

O-linked N-acetylglucosamine levels in cerebellar neurons respond reciprocally to pertubations of phosphorylation.

The novel intracellular carbohydrate O-linked N-acetylglucosamine (O-GlcNAc) is present on proteins ranging from those of viruses to those of humans and include cytosolic, nuclear and plasma-membrane proteins. In this report we have examined the effect of manipulation of phosphorylation on the levels of O-GlcNAc in cerebellar neurons from early postnatal mice. Our results indicate a reciprocal response of O-GlcNAc levels to phosphorylation. Activation of protein kinase A or C, for example, results in reduced levels of O-GlcNAc specifically in the fraction of cytoskeletal and cytoskeleton-associated proteins, while inhibition of the same kinases results in increased levels of O-GlcNAc. These data are in keeping with a reciprocal action of O-GlcNAc with respect to phosphorylation and suggest that this modification may have a role in signal transduction.

Predicting response to cognitive behavior therapy of depression in type 2 diabetes.

Little is known about which factors may adversely affect response to psychotherapy in diabetic patients with major depression. We studied the relationship of various demographic, diabetes, and depression characteristics to change in depression in 42 patients with type 2 diabetes who completed a randomized clinical trial of cognitive behavior therapy (CBT). Depression remitted in a significantly greater percentage of the patients treated with CBT than with the control intervention (85.0% vs 27.3%, p < 0.001). In the sample as a whole, nonremission of depression was associated with lower compliance with blood glucose monitoring, higher glycated hemoglobin (GHb) levels, higher weight, and a history of previous treatment for depression. In the group treated with CBT, the presence of diabetes complications and lower compliance with blood glucose monitoring were significant independent predictors of diminished response. These findings show that factors related to the medical illness, such as the presence of diabetes complications, may negatively influence the prognosis for recovery from depression. Specific coverage of these issues during psychotherapy may optimize the likelihood of treatment success in patients with diabetes.

Cognitive behavior therapy for depression in type 2 diabetes mellitus. A randomized, controlled trial.

BACKGROUND: Psychotherapy is the principal nonpharmacologic method for the management of depression, but its usefulness for depressed patients with diabetes remains unknown. OBJECTIVE: To assess the efficacy of cognitive behavior therapy (CBT) for depression in patients with diabetes. DESIGN: Randomized, controlled trial. SETTING: Referral-based academic medical center. PATIENTS: 51 patients with type 2 diabetes and major depression. INTERVENTION: Patients were assigned either to a group that received 10 weeks of individual CBT or to a control group that received no specific antidepressant treatment. All patients participated in a diabetes education program to control for the effects of supportive attention and the possible influence of enhanced diabetes control on mood. MEASUREMENTS: Degree of depression was measured by using the Beck Depression Inventory; glycemic control was measured by using glycosylated hemoglobin levels. Outcomes were assessed immediately after treatment and 6 months after treatment. RESULTS: The percentage of patients achieving remission of depression (Beck Depression Inventory score < or = 9) was greater in the CBT group than in the control group: posttreatment, 85.0% of patients in the CBT group (17 of 20) compared with 27.3% of controls (6 of 22) achieved remission (difference, 57.7 percentage points [95% CI, 33 to 82 percentage points]) (P < 0.001); at follow-up, 70.0% of patients in the CBT group (14 of 20) compared with 33.3% of controls (7 of 21) achieved remission (difference, 36.7 percentage points [CI, 9 to 65 percentage points]) (P = 0.03). Post-treatment glycosylated hemoglobin levels were not different in the two groups, but follow-up mean glycosylated hemoglobin levels were significantly better in the CBT group than in the control group (9.5% compared with 10.9%; P = 0.03). CONCLUSIONS: The combination of CBT and supportive diabetes education is an effective nonpharmacologic treatment for major depression in patients with type 2 diabetes. It may also be associated with improved glycemic control.

Tyrosine and serine phosphorylation of the neural cell adhesion molecule L1 is implicated in its oligomannosidic glycan dependent association with NCAM and neurite outgrowth.

We have previously shown that a cis interaction between the cell adhesion molecules L1 and NCAM is mediated by N-linked oligomannosidic glycans carried by L1 and that this L1/NCAM association is involved in basal neurite outgrowth from early postnatal cerebellar neurons of mouse brain [R. Horstkorte et al., J. Cell Biol. 121, 1409-1421 (1993)]. Extending these earlier studies we investigated signal transduction mechanisms elicited by this molecular interaction. We show here that phosphorylation of L1 is reduced concomitant with reduced neurite outgrowth when the L1/NCAM interaction is inhibited by oligomannosidic glycopeptides. Similarly, when a peptide of the 4th immunoglobulin (Ig)-like domain of NCAM - representing part of NCAM's carbohydrate-binding site - was added to the culture medium of the cells, neurite outgrowth and phosphorylation of L1 was strongly reduced. No effect on neurite outgrowth and phosphorylation of L1 was observed when cells were maintained in the presence of a peptide comprising part of the 1st Ig-like domain of NCAM or in the presence of the peptide encoded by the variable alternative spliced exon (VASE), which is also located in the 4th Ig-like domain of NCAM. Furthermore, phosphorylation of tyrosine and serine residues of L1 is reduced when the L1/NCAM interaction at the cell surface of cerebellar neurons is perturbed. Our observations suggest that a signal transduction mechanism is implicated in basal neurite outgrowth in which both tyrosine and serine phosphorylation of L1 represent a possible proximal step. Some of these results were presented at the International Glycoconjugate Symposium in Seattle, USA [P. C. Heiland et al., Glycoconj. J. 12, 521(1995)].

Takayansu's Arteritis Associated with Anterior Uveitis and Cutaneous Extravascular Necrotizing Granuloma.

We describe a case of Takayasu's arteritis (TA) associated with two unusual complications: 1) granulomatous anterior uveitis, and 2) skin nodules demonstrating a cutaneous extravascular necrotizing granuloma. This is the first report of uveitis attributed to TA and the second report of this skin lesion (associated with a small vessel vasculitis) occurring in this disorder. Although an ocular finding was central to the initial description of TA in 1908, eye abnormalities in this disorder are frequently overshadowed by other consequences of vasculitis in large vessels. In this case, correct interpretation of the skin biopsy findings in the context of the known great vessel abnormalities might have led to a more timely diagnosis of TA. Finally, although TA is the prototype of large vessel vascu-litides, this case illustrates the range in the size of blood vessels involved by this form of arteritis. Once the diagnosis was made, the patient responded promptly to a treatment regimen of prednisone and methotrex-ate.

Effects of nortriptyline on depression and glycemic control in diabetes: results of a double-blind, placebo-controlled trial.

OBJECTIVE: Depression is a prevalent and chronic condition in diabetes and is associated with poor glucose regulation and poor compliance with diabetes treatment. This investigation evaluated the effects of nortriptyline on depression and glycemic control to see whether depression in diabetes is treatable and whether restoring mental health contributes to improved medical outcome. METHOD: Sixty-eight diabetic patients with poor glycemic control, 28 of whom had active major depression (DSM-IIIR), completed a randomized, placebo-controlled, double-blind trial involving 8 weeks of treatment with nortriptyline targeted to therapeutic plasma levels (50-150 ng/ml). Depression improvement was determined with the Beck Depression Inventory; glucose control was measured by glycated hemoglobin levels. Compliance behavior was assessed using medication dispensing devices and glucometers equipped with electronic memory. RESULTS: The reduction in depression symptoms was significantly greater in depressed patients treated with nortriptyline compared with those receiving placebo (-10.2 vs -5.8, p = .03). Nortriptyline was not statistically superior to placebo in reducing glycated hemoglobin of the depressed subjects (p = .5). However, path analysis indicated that the direct effect of nortriptyline was to worsen glycemic control whereas depression improvement had an independent beneficial effect on glycated hemoglobin. These findings were not explained by the relationships of nortriptyline treatment to weight change (r = -0.21, p = .31) or depression improvement to compliance with the protocol for self-monitoring of blood glucose (r = 0.01, p = .97). CONCLUSIONS: Major depression in diabetic patients can be effectively treated with nortriptyline at the expense of a direct hyperglycemic effect. Path analysis demonstrated a treatment-independent effect of depression improvement on glycemic control, suggesting that a more ideal antidepressant agent may both restore mental health and improve medical outcome.

The course of major depression in diabetes.

The course of depression in patients with comorbid medical illness is poorly understood. We report a 5-year follow-up study of 25 diabetic patients who had participated in an 8-week depression treatment trial. When a patient completed the trial, primary physicians were informed of patient outcomes and advised to monitor for relapse and treat those with ongoing depression. At the 5-year reevaluation depression was assessed using DSM-III-R criteria, and a depression severity scale was formed that reflected the presence, severity, frequency, and duration of depression episodes as well as a global assessment of functioning. Recurrence or persistence of depression occurred in 23 (92%) of the patients with an average of 4.8 depression episodes over the 5-year follow-up period. The duration of the longest episode averaged 16 +/- 4 months. Reversion to major depression occurred frequently and rapidly also in the subset that remitted during the treatment trial: 58.3% were depressed again within the first year. At the time of the follow-up interview, major depression was evident in 16 (64%) of the subjects, and glycemic control was significantly worse in this group compared with those without depression (gHb: 13.3% +/- 2.6% vs 11.1% +/- 1.9%, P = 0.03). Severity of depression over follow-up was related to the presence of neuropathy at entry and to incomplete remission during the initial treatment trial. Nineteen patients (82.6% of those who relapsed) received additional courses of antidepressant therapy, but none was treated continuously for depression prophylaxis. In this diabetic sample, depression was a recurrent condition in the vast majority of cases, and initial treatment response did not confer lasting euthymia. Whether maintenance antidepressant medication would be useful in preventing depression recurrence and promoting better glycemic control in diabetes remains to be studied.

Screening for depression in diabetes using the Beck Depression Inventory.

OBJECTIVE: The purpose of this study was to determine the utility of the Beck Depression Inventory (BDI) as a screening tool for major depression in diabetes. METHOD: One hundred seventy-two diabetic outpatients (insulin-dependent diabetes mellitus [IDDM] = 59, or non-insulin-dependent diabetes mellitus [NIDDM] = 113) being evaluated for a treatment trial were studied. BDI scores were calculated for the complete 21-item measure as well as for the cognitive (13 items) and somatic (eight items) symptom subgroups. The presence of depression was determined using the National Institute of Mental Health Diagnostic Interview Schedule in accordance with the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Receiver operating characteristic (ROC) analyses were used to evaluate the performance of the screening test in relation to the diagnostic standard. RESULTS: Depressed subjects were effectively discriminated from nondepressed subjects by using the full 21-item BDI, the cognitive items alone, or the somatic items alone (p < .001 for each comparison), although the cognitive items were more effective than the somatic items (p < .0005). BDI total scores between 12 and 14 inclusive displayed the best balance between sensitivity (0.90-0.82) and specificity (0.84-0.89), but a cutoff score > or = 16 for the entire 21-item measure exhibited the best balance between sensitivity and positive predictive value when prediction values were extrapolated to a diabetic population with a depression prevalence rate of 20%. This cutoff score would capture > 70% of the patients diagnosed with major depression yet provide > 70% certainty that a person screening positive actually has the psychiatric disorder. CONCLUSION: The BDI is an effective screening test for major depression in diabetic patients. Prospective studies are needed to confirm the test's precise performance characteristics in the general clinical setting.

The neural adhesion molecule L1 is phosphorylated on tyrosine and serine residues.

The neural cell adhesion molecule L1 is highly homologous in its extracellular domain between species and completely identical in its cytoplasmic domain. We report here that tyrosine residues of L1 are phosphorylated in addition to serine residues, as determined by monoclonal phosphotyrosine antibodies and phosphoamino acid analysis. This result supports the suggestion that the cytoplasmic domain of L1 might be involved in signal transduction.

Effects of alprazolam on glucose regulation in diabetes. Results of double-blind, placebo-controlled trial.

OBJECTIVE: To determine the effects of alprazolam on glucose regulation in anxious and nonanxious patients with poor glycemic control and establish whether regulatory benefits are related to anxiolytic effects of the medication. RESEARCH DESIGN AND METHODS: Fifty-eight patients with poor glycemic control, 16 (27.6%) of whom had a symptomatic generalized anxiety disorder, were entered into a randomized, double-blind, placebo-controlled, 8-week trial using alprazolam (up to 2 mg/day) as the active agent. Generalized anxiety disorder was determined in accordance with Diagnostic and Statistical Manual of Mental Disorders criteria, and anxiety symptoms were measured using the Hopkins Symptom Checklist. Glycated hemoglobin levels were used to determine glucose regulation. Compliance behavior was assessed using glucometers and medication monitors equipped with electronic memory. RESULTS: A statistically significant reduction in glycated hemoglobin level was observed in patients treated with alprazolam compared with those receiving placebo (-1.1 vs. -0.3%, P = 0.04). This treatment effect was not a function of differences in compliance behaviors. Anxiety symptoms decreased in both alprazolam- and placebo-treated patients with generalized anxiety disorder, but reduction in glycated hemoglobin level was not dependent on alleviation of anxiety. CONCLUSIONS: A short course of alprazolam improved glucose regulation in patients with a history of poor diabetes control. This effect was not directly related to concomitant changes in anxiety. Alprazolam treatment of anxious patients with poorly controlled diabetes may result in decreased anxiety and improved glucose regulation through independent mechanisms.

O-linked N-acetylglucosamine is upregulated in Alzheimer brains.

We present evidence that the expression of the novel intracellular carbohydrate modification of proteins--O-glycosidically linked N-acetylglucosamine (O-GlcNAc)--is significantly upregulated in Alzheimer brains over that of age matched control brains. This increase is specific for proteins associated with the detergent insoluble cytoskeleton and not for proteins of the detergent soluble fraction and is not due to an increase in protein expression in this fraction. The possible involvement of abnormal phosphorylation in the disease state and the interplay between phosphorylation and the O-GlcNAc modification suggests that the increased level of intracellular O-GlcNAc expression may be implicated in the pathogenesis of Alzheimer's disease.

Beta-amyloid precursor protein is modified with O-linked N-acetylglucosamine.

The beta-amyloid precursor protein (APP) has been implicated in the etiology of Alzheimer's disease (Kang et al.: Nature 325:733-736, 1987; Selkoe: Science 248:1058-1060, 1990; Selkoe: In Cowan et al. (eds): "Annual Review of Neuroscience." Palo Alto, CA: Annual Reviews, Inc., pp 489-519, 1994) and numerous studies have shown that beta-amyloid is involved in amyloid plaque formation (Rumble et al.: N Engl J Med 320:1446-1452, 1989; Sisodia et al.: Science 248: 492-495, 1990). Evidence is presented that APP is modified with N-acetylglucosamine linked to cytoplasmic serine or threonine residues (O-GlcNAc). This is the first report of a plasma membrane protein modified with this carbohydrate. It has been postulated that this modification, which is ubiquitous in all organisms studied to date except bacteria (Haltiwanger et al.: Biochem Soc Trans 20:264-269, 1992; Dong et al.: J Biol Chem 268:16679-16687, 1993; Elliot et al.: J Neurosci 13:2424-2429, 1993; Kelly et al.: J Biol Chem 268:10416-10424, 1993), may function as an alternative to phosphorylation (Dong et al., 1993) and is involved in the multimerization of proteins (Haltiwanger et al., 1992; Dong et al., 1993). O-GlcNAc occurs at "PEST" sequences (Rogers et al.: Science 234:364-368, 1986) and it has been suggested that this modification within such a sequence leads to increased proteolytic stability of the molecule (Dong et al., 1993).(ABSTRACT TRUNCATED AT 250 WORDS)

L2/HNK-1 carbohydrate and protein-protein interactions mediate the homophilic binding of the neural adhesion molecule P0.

The neural adhesion molecule P0, the most abundant glycoprotein in peripheral myelin of mammals, is a member of the immunoglobulin superfamily and expresses the L2/HNK-1 and L3 oligosaccharides at a single N-glycosylation site. It acts in both homophilic and heterophilic binding mechanisms. To investigate the molecular requirements for homophilic interaction, we have used P0 from human sciatic nerve and the extracellular domain of P0 expressed in bacteria to determine binding of P0 to P0 in solid phase and bead aggregation assays. The binding of P0 to P0 could be partially inhibited in both assays by antibodies to the L2/HNK-1 epitope and by the L2/HNK-1 carbohydrate, but not by L3 antibodies or other carbohydrates. Inhibition of binding was also seen with polyclonal antibodies reacting with the protein backbone of P0. These observations indicate that both carbohydrate and protein structures are involved in the binding of P0 to P0 and that P0 acts as a presenter of and a receptor for a functionally important carbohydrate.

Depression in adults with diabetes.

Depression in diabetes is a prevalent and chronic condition. The etiology is unknown but is probably complex; and biological, genetic, and psychological factors remain as potential contributors. Several neuroendocrine and neurotransmitter abnormalities common to both depression and diabetes have been identified, adding to etiological speculations. Pharmacotherapy of depression may improve both mood and glucose regulation in diabetes, although controlled studies of the efficacy of psychotherapy and pharmacotherapy for depression in diabetes are not yet available. Depression has potential interactions with diabetes on multiple levels and remains an important clinical focus independent of the medical disease.

Role of Fc gamma RII in platelet activation by monoclonal antibodies.

mAb are being widely used to probe the function of cell-surface proteins. The cell stimulation that may be produced is often dependent on mAb interaction with both the target Ag and FcR. However, it remains unclear whether these interactions take place on the same cell or between adjacent cells and whether the FcR plays an anchoring or signaling role. Using the model of platelet activation, we demonstrate that two different Fc-dependent mAb, LeoA1 and ALB6, both activate the cell by forming intercellular links between Ag on one cell and FcR on the opposing platelet. We also show that the mAb differ with respect to the relative roles of target Ag vs FcR in provision of the stimulation signal. Thus Fc gamma RII played a mainly anchorage role in LeoA1 stimulation, whereas its role in ALB6 stimulation was mainly signaling. Therefore the precise contribution of each of these roles to the overall effect of a stimulatory antibody should be determined before the antibody is used as a specific functional probe.

Long-term follow-up of patients with nonischemic dilated cardiomyopathy and ventricular tachyarrhythmias treated with implantable cardioverter defibrillators.

We analyzed our 10-year cumulative experience of 40 consecutive patients with idiopathic dilated cardiomyopathy and associated ventricular tachyarrhythmias, treated with implantable cardioverter defibrillators. Dilated cardiomyopathy was defined as left ventricular ejection fraction (EF) less than or equal to 50% with no defineable etiology. Patient characteristics included: 24 male, mean age 52 years, mean EF = 33%, New York Heart Association Class I-III, presenting syndrome--cardiac arrest (n = 28), syncope/near syncope (n = 12). At 2.5 years mean follow-up, there were 16 deaths: one operative, three sudden, two incessant ventricular tachycardia/ventricular fibrillation (VT/VF), six heart failure, and four noncardiac. The actuarial mortality at 1 and 4 years was 0% and 14% for sudden death, 11% and 34% for cardiac death. The projected mortality was 52% and 78% for same time intervals (P less than 0.01). No useful baseline variable predicted who would or would not receive an ICD shock in follow-up. ICD therapy appears effective in reducing sudden death mortality in this high risk population.

Predictors of first discharge and subsequent survival in patients with automatic implantable cardioverter-defibrillators.

BACKGROUND: Two hundred eighteen patients were evaluated in a two-phase approach (time to first appropriate discharge, survival after discharge) to identify factors that may be related to maximal benefit derived from use of an automatic implantable cardioverter-defibrillator (AICD). METHODS AND RESULTS: One hundred ninety-seven patients survived implantation of AICD, with or without concomitant cardiac surgery. One hundred five patients had an AICD discharge associated with syncope, presyncope, documented sustained ventricular tachycardia or fibrillation, or sleep at 9.1 +/- 11.1 months after implantation. Patients survived 23.8 +/- 18.0 months after AICD discharge. Left ventricular dysfunction (p = 0.008 for ejection fraction less than 25%) was associated with earlier AICD discharge and shortened survival after AICD discharge (p = 0.008 for ejection fraction less than 25%; p = 0.01 for New York Heart Association functional class III and IV). beta-Blocker administration (p = 0.006) and coronary bypass surgery (p = 0.06) were associated with later AICD discharge. Coronary bypass surgery (p = 0.035) but not beta-blockers was associated with more prolonged survival after AICD discharge. CONCLUSIONS: These data suggest that a relatively easy algorithm can be applied to predict which patient will benefit most from AICD implantation.

Mexiletine-associated left ventricular dysfunction: a case study.

Mexiletine is a lidocaine analogue used in the treatment of symptomatic ventricular arrhythmias. However, in selected individuals with baseline diminished left ventricular function, it may possess clinically significant negative inotropic effects.