Differential effect of phorbol esters and interleukin-3 on protein kinase C isoform content and kinase activity in the FDC-P1 cell line

FD/PMA is a subclone of the interleukin-3 (IL-3)-dependent, FDC-P1 cell line, which proliferates in response to either 12-O- tetradecanoylphorbol-13 acetate (PMA) or IL-3. While several endogenous substrates were phosphorylated in response to protein kinase C (PKC) activation in FDC-P1, phospholipid-dependent phosphorylation in the FD/PMA grown in PMA was not observed. Basal, phosphatidylserine- independent, and diolein-independent phosphorylation of cytosolic substrates with molecular weights of 17, 52, 57, and 105 Kd were enhanced in FD/PMA cells grown in PMA as compared with FDC-P1 cells cultured in IL-3. Phosphorylation of a 105-Kd substrate was enhanced in the particulate fraction of FD/PMA cells maintained in PMA. The 17-Kd substrate in FD/PMA cells comigrated with a substrate phosphorylated in a PKC-dependent manner in FDC-P1 cells. Phosphorylation of the 52- and 57-Kd substrates, but not of the 17-Kd substrate, was inhibited by H-7 and staurosporine. A portion of the PMA-induced cytosolic kinase activity coeluted with PKC on diethyl aminoethyl chromatography. While FD/PMA cells cultured in PMA contained negligible PKC-dependent phosphorylation of endogenous substrates or histone, alpha and epsilon PKC isoforms were detected by Western blot analysis. PKC phosphotransferase activity was observed in FD/PMA cells grown in PMA when peptides corresponding to residues 720 to 737 of PKC-epsilon or residues 4 to 14 of myelin basic protein were used as substrates. These data indicate that maintenance of FD/PMA cells in PMA stimulates proliferation and markedly alters PKC substrate specificity. Generation of at least two phospholipid-independent kinases occurs in PMA-treated cells.     

Factors Associated With Microalbuminuria in 7,549 Children and Adolescents With Type 1 Diabetes in the T1D Exchange Clinic Registry

OBJECTIVE

To examine factors associated with clinical microalbuminuria (MA) diagnosis in children and adolescents in the T1D Exchange clinic registry.

RESEARCH DESIGN AND METHODS

T1D Exchange participants <20 years of age with type 1 diabetes ≥1 year and urinary albumin-to-creatinine ratio (ACR) measured within the prior 2 years were included in the analysis. MA diagnosis required all of the following: 1) a clinical diagnosis of sustained MA or macroalbuminuria, 2) confirmation of MA diagnosis by either the most recent ACR being ≥30 mg/g or current treatment with an ACE inhibitor (ACEI) or angiotensin receptor blocker (ARB), and 3) no known cause for nephropathy other than diabetes. Logistic regression was used to assess factors associated with MA.

RESULTS

MA was present in 329 of 7,549 (4.4%) participants, with a higher frequency associated with longer diabetes duration, higher mean glycosylated hemoglobin (HbA_1c) level, older age, female sex, higher diastolic blood pressure (BP), and lower BMI (P ≤ 0.01 for each in multivariate analysis). Older age was most strongly associated with MA among participants with HbA_1c ≥9.5% (≥80 mmol/mol). MA was uncommon (<2%) among participants with HbA_1c <7.5% (<58 mmol/mol). Of those with MA, only 36% were receiving ACEI/ARB treatment.

CONCLUSIONS

Our results emphasize the importance of good glycemic and BP control, particularly as diabetes duration increases, in order to reduce the risk of nephropathy. Since age and diabetes duration are important nonmodifiable factors associated with MA, the importance of routine screening is underscored to ensure early diagnosis and timely treatment of MA.Elevated urinary albumin excretion is an early sign of diabetic kidney disease (DKD). The American Diabetes Association (ADA) recommends screening for microalbuminuria (MA) annually in people with type 1 diabetes after 10 years of age and 5 years of diabetes duration, with a diagnosis of MA requiring two of three tests to be abnormal (1). Early diagnosis of MA is important because effective treatments exist to limit the progression of DKD (1). However, although reduced rates of MA have been reported over the past few decades in some (2–4) but not all (5,6) studies, it has been suggested that the development of proteinuria has not been prevented but, rather, has been delayed by ∼10 years and that further improvements in care are needed (7).Limited data exist on the frequency of a clinical diagnosis of MA in the pediatric population with type 1 diabetes in the U.S. Our aim was to use the data from the T1D Exchange clinic registry to assess factors associated with MA in 7,549 children and adolescents with type 1 diabetes.     

Orthotopic cardiac transplantation: evaluation with CT

As cardiac transplantation has become widely available, computed tomography (CT) of the chest has played a useful role in the examination of patients after heart transplantation. To determine anatomic features related to the procedure, the authors evaluated 59 scans in 46 patients who had undergone orthotopic cardiac transplantation. Aortic anastomosis (seen in 98% of scans) and altered spacing between the great vessels (83%) proved to be the most common and most reliable findings. Other features including atrial anastomosis, high main pulmonary artery segment, remnant superior vena cava, and cardiac reorientation were also seen. Accurate interpretation of adenopathy, mediastinal abscess, and pericardial effusion will be enhanced in these patients through a better understanding of the cardiovascular-pericardial complex, which is afforded by CT.     

Population response of midbrain dopaminergic neurons to neuroleptics: further studies on time course and nondopaminergic neuronal influences

In the present study, we examined the effects of the cholecystokinin receptor antagonist, proglumide, on the depolarization-induced inactivation of A9 and A10 dopaminergic neurons produced by repeated administration of a classical antipsychotic drug (dopamine receptor antagonist). In addition, we studied the nature of the effects of acute (1-48 hr) and long-term (7 month) treatment with the butyrophenone neuroleptic haloperidol on both the basal firing rate and population response of dopamine-containing neurons in these 2 regions. Acute oral administration of haloperidol (0.5 mg/kg) results, within 1 hr of administration, in an increase in both the firing rate and number of spontaneously active dopamine neurons encountered in both A9 and A10 regions. These effects of a single treatment persist for a minimum of 6 hr and, with respect to firing rate, are not completely normalized for at least 24 hr. In contrast, 7 month continuous treatment with haloperidol reduces the number of spontaneously active DA neurons encountered in both regions in a manner similar to that observed at 21 d. This effect is inferred to be due to the induction of depolarization-induced inactivation of these neurons, since the acute administration of the normally hyperpolarizing, direct-acting dopamine receptor agonist apomorphine (64 micrograms/kg) immediately reverses this reduced number of cells per track to near control levels. This effect appears to be dependent on the continued presence of haloperidol since, when animals treated for 7 months are sampled 14 d after the cessation of drug administration, spontaneous activity is no different from that observed in age-matched controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mechanisms of action of atypical antipsychotic drugs. Implications for novel therapeutic strategies for schizophrenia.

The mechanisms which contribute to the actions of atypical antipsychotic drugs, such as clozapine and the putative atypical agents remoxipride and raclopride, are reviewed. Examination of available preclinical and clinical data leads to two hypotheses concerning the mode of action of atypical antipsychotic drugs. The first hypothesis is that antagonism of the dopamine D2 receptor is both necessary and sufficient for the atypical profile, but that interaction with subtypes of the D2 receptor differentiates typical from atypical antipsychotic drugs. The second hypothesis has been previously advanced, and suggests that a relatively high ratio of serotonin 5-HT2:dopamine D2 receptor antagonism may subserve the atypical profile. It seems likely that the atypical antipsychotic drug profile may be achieved in more than one way.     

Efficacy and tolerability of pantoprazole 40 mg versus 80 mg in patients with reflux oesophagitis.

BACKGROUND: Pantoprazole is a substituted benzimidazole which is a potent inhibitor of gastric acid secretion by its action upon H+, K+- ATPase. METHODS: Pantoprazole 40 mg and 80 mg were compared in a randomized double-blind study in 192 out-patients with stage II or III (Savary-Miller classification) reflux oesophagitis. Patients received either pantoprazole 40 mg (n = 97) or pantoprazole 80 mg (n = 95), once daily before breakfast for 4 weeks. Treatment was extended for a further 4 weeks if the oesophagitis had not healed. RESULTS: After 4 weeks complete healing of the reflux oesophagitis was seen in 78% of protocol-correct patients given pantoprazole 40 mg daily (n = 86), and in 72% in the 80 mg (n = 87) group. The cumulative healing rates after 8 weeks were 95 and 94%, respectively (P > 0.05, Cochran-Mantel- Haenszel), and time until healing of oesophagitis comparable in both groups. Differences between doses were also not significant in an intention-to-treat analysis. Both dosing schedules were well tolerated and the patients experienced remarkable symptom relief. No adverse event or changes in laboratory values of clinical significance could definitely be ascribed to the trial medication. CONCLUSION: The 40 mg pantoprazole dosage is comparable to 80 mg in reflux oesophagitis, both in efficacy and tolerability.