Depression of long term potentiation in gerbil hippocampus following postischemic hypothermia

To investigate the mechanism of chronic cell death following postischemic hypothermia, the change of N-methyl-D-aspartate receptor (NMDAR) were examined by immunohistochemistry of NMDAR1 and long-term potentiation (LTP) in the CA1 subfield of the gerbil hippocampus. At 1 week following postischemic hypothermia (32 degrees Cx4 h), all CA1 neurons survived; however, immunoreactivity of NMDAR1 increased in neuronal perikarya whereas decreased in dendrites in the CA1 neurons. The abnormality was still observed in remaining CA1 neurons at 1 month after hypothermia. LTP was also significantly depressed at 1 week after hypothermia. These results suggest that some abnormalities in the glutamate receptor may be caused by ischemia; such abnormality would persist in spite of hypothermia treatment, resulting in the depression of LTP.

Effects of luteinizing hormone, follicle-stimulating hormone, and epidermal growth factor on expression and kinase activity of cyclin-dependent kinase 5 in Leydig TM3 and Sertoli TM4 cell lines

We examined the effects of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and epidermal growth factor (EGF) on the expression and kinase activity of cyclin-dependent kinase 5 (Cdk5) in Leydig TM3 and Sertoli TM4 cell lines. Hormonal regulation of the expression and activity of Cdk5 by using normal and hypophysectomized rat testes was also investigated to elucidate its role. Cdk5 levels and kinase activity were significantly elevated in TM3 cells that were grown in the presence of 7.5% serum, EGF, or LH and were associated with an increase in testosterone production compared with controls. These increases were accompanied by an increase in proliferation of TM3 cells after treatment with serum or EGF but not with LH suggest that Cdk5 may be involved in cellular differentiation that is induced with LH treatment. In contrast, the presence of neither serum, EGF, nor FSH had a significant effect on Cdk5 activity levels in the Sertoli TM4 cell line, and there was no correlation with proliferative activity or transferrin levels. A significant decrease in Cdk5 expression and activity were noted in rat testis after hypophysectomy compared with normal rat testis and is associated with a simultaneous decrease in testosterone and transferrin levels. Immunohistochemical analysis revealed that Cdk5 was strongly expressed in the nuclei and cytoplasm of Leydig cells, Sertoli cells, spermatogonia, and peritubular cells of normal adult rat testis. After hypophysectomy, the pattern of Cdk5 staining differed markedly from that in normal rat testis and a profound reduction in staining of Cdk5 was observed in each tubule. Our results suggest that LH and EGF influence and modulate Cdk5 expression and activity in Leydig TM3 cells and may, conceivably, be involved in signal transduction cascades that are initiated by hormones or growth factors. Cdk5 in Sertoli TM4 cells is likely to possess some constitutive functions that are not affected by the cells' proliferation state. Moreover, Cdk5 is probably involved in the constitutive and hormonally stimulated activities of the rat testis, in addition to its involvement in cell proliferation.

Sequential changes of KL-6 in sera of patients with interstitial pneumonia associated with polymyositis/dermatomyositis

OBJECTIVE

KL-6 is a mucin-like high molecular weight glycoprotein, which is strongly expressed on type II alveolar pneumocytes and bronchiolar epithelial cells. It has been demonstrated that the KL-6 antigen is a useful marker for estimating the activity of interstitial pneumonia. In this study, it is hypothesised that serum KL-6 is a useful marker to evaluate the activity of interstitial pneumonia associated with polymyositis/dermatomyositis (PM/DM).

METHODS

KL-6 was measured in sera in 16 patients diagnosed with PM/DM. Five had non-specific interstitial pneumonia (NSIP), three had diffuse alveolar damage (DAD), and eight had no pulmonary involvement, and 10 were normal non-smokers as a control group. The correlation was also evaluated between the KL-6 level and each clinical course in patients with pulmonary involvement associated with PM/DM. Immunohistochemical analysis using monoclonal anti-KL-6 antibody was also performed.

RESULTS

KL-6 concentrations in sera of patients with interstitial pneumonia associated with PM/DM were significantly high compared with those of PM/DM without interstitial pneumonia, and normal non-smokers. KL-6 concentrations in sera in patients with DAD significantly increased compared with those of other groups. KL-6 values in sera changed according to the progression or improvement of interstitial pneumonia. Immunohistochemical study using pulmonary tissues obtained from patients with DAD demonstrated that the hyaline membrane, proliferating type II pneumocytes, bronchial epithelial cells and some endothelial cells in pulmonary veins were stained by antihuman KL-6 antibody.

CONCLUSION

These data demonstrate that measurement of serum KL-6 was a useful marker to evaluate the activity of acute interstitial pneumonia associated with PM/DM.

Purification, identification and phosphorylation of annexin I from rat liver mitochondria

Annexin was purified from rat liver mitochondria to an apparent homogeneity with a molecular weight of 35 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified mitochondrial annexin (AXmito) was identified as annexin I by an immunoblot analysis using anti-annexin I antibody. The inhibitory effect of AXmito I on porcine pancreatic phospholipase A2 activity was as potent as that of bovine lung annexin I. The presence of annexin I in mitochondria was confirmed by an electron-microscopic study. AXmito I was shown to be phosphorylated by intrinsic protein tyrosine kinases on its tyrosine residues. This annexin was also phosphorylated by protein kinase C.

Echocardiographic observation of acute myocarditis with systemic lupus erythematosus

Although myocarditis from a series of autopsies of patients with systemic lupus erythematosus was frequently observed, the incidence of clinically apparent myocardial dysfunction was low. A 30-year-old woman with systemic lupus erythematosus was examined by echocardiography. An acoustic densitometry was followed at the left ventricular posterior wall throughout the clinical course. A decrease in the magnitude of cyclic variation of integrated backscatter (IB) was observed before treatment. Following the combined treatment, steroid and cyclophosphamide, a repeated ultrasonic tissue characterization showed an increase in the magnitude of cyclic variation of IB. It is thought that ultrasonic tissue characterization may be a useful method to evaluate the impairment of contraction, and to follow up the clinical course of myocardial involvement in systemic lupus erythematosus.

Presenilin-1 protein specifically expressed in Leydig cells with its expression level increased during rat testis development

Presenilin-1, mutations of which cause the early-onset of Alzheimer's disease, was shown to be abundantly expressed in the testis as well as the brain. In spite of the high expression level of this protein in the testis, no further analysis has been undertaken. We aimed to study the distribution and developmental changes in presenilin-1 protein, and to provide clues so as to elucidate the role of this protein in the rat testis. To evaluate the specificity of the anti presenilin-1 antibody, rat presenilin-1 protein was expressed in COS-7 cells and the recombinant protein was used for western blot analysis. A positive band of approximately 20 kDa corresponding to the C-terminal fragment of proteolyzed presenilin-1 protein was observed. Using testis and brain tissue samples, a 20 kDa band was detected in both tissues suggesting a similar proteolytic process, but the expression level in the testis was higher than that in the brain. The expression level increased significantly during postnatal testis development. By an immunohistochemical analysis of the rat testis, a strong signal was observed in interstitial cells and further study with cultured TM3 murine Leydig cells revealed an abundant expression of presenilin-1 in Leydig cells. Our study suggests that presenilin-1 expression in Leydig cells may play an important role in Leydig cell function and testis development.

A possible novel src-related tyrosine kinase in cancer cells of LEC rats that develop hepatocellular carcinoma

BACKGROUNDS/AIMS

Src-related protein tyrosine kinase is known to be related to cell transformation. In this study, we report a possible novel src-related tyrosine kinase of 100 kDa specifically expressed in the nuclei of hepatocytes and/or cancer cells in Long-Evans Cinnamon rats, one of the experimental models of hepatocellular carcinoma.

METHODS

Src-related protein tyrosine kinase in hepatocytes of Long-Evans Cinnamon rats was analyzed by using immunohistochemistry and Western blot and in vitro tyrosine kinase assay using a specific antibody (src antibody) against a synthetic peptide corresponding to the conserved autophosphorylation site of src family tyrosine kinases.

RESULTS

Src-related protein was found to be expressed in the nuclei of hepatocytes and/or cancer cells in Long-Evans Cinnamon rat liver, exhibiting tyrosine kinase activity, and migrated to the position of 100 kDa. The protein quantity and activity of this 100-kDa src-related protein tyrosine kinase significantly increased with the progress of chronic hepatitis to hepatocellular carcinoma, especially in the tumorous portion of the liver. On the other hand, the 100-kDa src-protein tyrosine kinase was not observed in the nuclei of hepatocytes and/or cancer cells in normal age-matched control Wistar rats.

CONCLUSIONS

Since the src-family tyrosine kinases have been observed at a molecular weight of 55 to 62 kDa and located in the hepatocellular membrane and/or cytoplasm, the 100-kDa src-related protein tyrosine kinase observed in the present study may be novel, and closely related to the pre-cancerous and cancerous process in Long-Evans Cinnamon rat liver.

[A case of amyopathic dermatomyositis presenting blister and oral ulcer]

An 84-year old man was admitted to Mitoyo General Hospital because of progressive malaise and edematous erythema on both eyelids (Heliotrope erythema). He also noted blister on his neck as well as erythema on the extensor surface of finger joints (Gottron's sign), elbows and knees. Neither weakness nor pain of his proximal muscle was elicited on physical examination on admission. His blood test disclosed positive inflammatory signs (i.e., mild elevation of ESR and positive CRP) without elevated value of muscle enzymes. Electromyogram showed normal pattern. Infiltration of inflammatory cells was not revealed by histological examination of biopsied muscle. A diagnosis of 'amyopathic dermatomyositis' was made based on these observations. Computed tomography of his chest disclosed interstitial pneumonia spreading over both lower lung fields. Colon fiberscopy revealed a polyp in his descending colon, which was classified into group I on cytological examination. He was treated with two sets of methylprednisolone (mPSL) pulse therapy (500 mg/day, 3 consecutive days, intravenously) followed by 30 mg/day of oral prednisolone (PSL). His skin lesions responded well to the above treatment and the dose of oral PSL was tapered. One month after the initiation of treatment, severe stomatitis as well as a large ulcer beneath his tongue developed accompanying an intractable pain. Mucosal biopsy revealed necrotizing vasculitis in medium-sizedartery at the bottom of ulcer. Another set of mPSL pulse therapy brought a prompt relief of his symptom and prohibited the recurrence of oral lesion. It should be noted that our patient did not fulfill the diagnostic criteria for DM because of the lack of muscular symptoms whereas he had characteristic skin lesions. Regarding the frustration possibly encountered at the time of diagnosing amyopathic DM, both sensitivity and specificity of the skin lesion for the diagnosis of DM were investigated. Moreover, the rarity of blister as a skin manifestation of DM was discussed as well.

Detection of anti-ADAM 10 antibody in serum of a patient with pulmonary fibrosis associated with dermatomyositis

OBJECTIVES

It has been suggested that the humoral immune system plays a part in the pathogenesis of pulmonary fibrosis. Although circulating autoantibodies to lung protein(s) have been suggested, few lung proteins have been characterised. The purpose of this study is to determine the antigen recognised by serum of a patient with pulmonary fibrosis associated with dermatomyositis.

METHODS

To accomplish this, anti-small airway epithelial cell (SAEC) antibody in a patient's serum was evaluated using a western immunoblot.

RESULTS

An autoantibody against SAEC was found, and the antigen had a molecular weight of 62 kDa. Using the patient's serum, clones from the normal lung cDNA library were screened and demonstrated that anti-SAEC antibody in the patient's serum was against ADAM (A disintegrin and metalloprotease) 10.

CONCLUSION

This is the first report that demonstrates the existence of anti-ADAM 10 antibody in a patient with pulmonary fibrosis associated with dermatomyositis.

Elevation of cytokeratin 19 fragment in patients with interstitial pneumonia associated with polymyositis/dermatomyositis

OBJECTIVE

Cytokeratin 19 fragment (CK19) levels in serum have been documented as a useful tumor marker for lung cancer. We hypothesize that CK19 may increase in serum in patients with interstitial pneumonia associated with polymyositis/dermatomyositis (PM/DM) and CK19 might be a useful variable to evaluate the activity of lung injury.

METHODS

1. We measured CK19 in sera in 15 patients diagnosed with PM/DM; 6 had nonspecific interstitial pneumonia (NIP), 4 had acute interstitial pneumonia (AIP), and 5 had no pulmonary involvement. We also measured CK19 in 10 healthy nonsmokers serving as a control group. 2. We evaluated the correlation between CK19 level and individual clinical course in patients with pulmonary involvement associated with PM/DM.

RESULTS

CK19 levels in sera of patients with NIP associated with PM/DM were significantly higher versus patients with PM/DM without interstitial pneumonia and healthy nonsmokers. CK19 levels in sera in patients with AIP associated with PM/DM were significantly higher compared with the other groups. CK19 values in sera changed according to the progression or improvement of interstitial pneumonia. Immunohistochemical studies using pulmonary tissues obtained at autopsy from patients with AIP associated with PM/DM revealed that the hyaline membrane was mostly stained by anti-human cytokeratin 19 monoclonal antibody as well as the strong positivity of proliferating type II pneumocytes.

CONCLUSION

These results suggest that the measurement of CK19 was a useful variable to evaluate the activity of lung injury in interstitial pneumonia associated with PM/DM.

Molecular cloning of EDG-3 and N-Shc genes from the puffer fish, Fugu rubripes, and conservation of synteny with the human genome

EDG-3 is a receptor for sphingosine-1-phosphate mapped on human chromosome 9q22.1-q22.2. We used the compact Fugu genome for its linkage analysis. The Fugu EDG-3 was composed of one intron and two exons, encoding a 384 amino acid protein that has 56.9% homology with the human EDG-3. Approximately 3 kb apart, a neuronal Shc (N-Shc) gene was identified. It spans 7 kb containing 12 coding exons, and has an overall 53.4% similarity with the human protein. We mapped the human N-Shc gene to chromosome 9q21.3-q22.2. This is the first report of the genomic structure and the linkage of these two genes conserved between Fugu and human.

The expression of Ca2+/calmodulin-dependent protein kinase I in rat retina is regulated by light stimulation

Ca2+/calmodulin-dependent protein kinase I (CaM-kinase I) in rat retina was analyzed by immunohistochemical analysis, Western blot analysis and kinase activity assay. Western blot analysis revealed two immunoreactive bands similar to those detected in the brain. Developmental studies revealed that CaM-kinase I expression increased in accordance with postnatal development. Expression of CaM-kinase I in the retinas of rats raised in the complete darkness markedly decreased. CaM-kinase I activity assay supported these findings. Synapsin I was shown to be a possible intrinsic substrate of CaM-kinase I in rat retina. These results elucidated that CaM-kinase I is expressed in the retina and may play an important role in the retinal functions and that the expression of CaM-kinase I is regulated by light stimulation.

Vectorcardiographic evaluation of myocardial infarct size: comparisons with thallium myocardial scintigraphy

OBJECTIVE

To determine the usefulness of vectorcardiography (VCG) in assessing myocardial infarct size.

METHODS

The correlation of spatial and scalar parameters of VCG with the percent defect volume (%DV) of thallium myocardial single photon emission computed tomography (SPECT) was investigated in 63 patients with first-onset myocardial infarction (MI). VCG parameters included: (1) spatial parameters: magnitude, azimuth and elevation of the maximal vector, vectors at 20 ms and 30 ms, and (2) scalar parameters: amplitudes of 20 ms and 30 ms vectors at X, Y, and Z scalar leads abbreviated as X20, Y20, Z20, X30, Y30 and Z30, respectively.

RESULTS

For anteroseptal MI, the azimuth of 30 ms vector and Z20 showed a significant correlation with %DV (r = 0.572, P < 0.05 and r = 0.832, P < 0.001) while in anteroseptal MI with involvement of lateral wall, the azimuth of 30 ms vector and X30 were correlated with %DV significantly (r = 0.775, and r = 0.780, P < 0.01). For inferior and inferoposterior MI, the elevation of 30 ms vector and Y30 were correlated well with %DV (r = 0.871, P < 0.01, r = 0.928, P < 0.001 for inferior MI and r = 0.678, P < 0.01, r = 0.760, P < 0.001 for inferoposterior MI).

CONCLUSION

VCG parameters, especially scalar parameters, can be used to evaluate myocardial infarct size easily and non-invasively with remarkable accuracy.

Elevation of anti-cytokeratin 19 antibody in sera of the patients with idiopathic pulmonary fibrosis and pulmonary fibrosis associated with collagen vascular disorders

It has been suggested that cytokeratin 19 is expressed in regenerated bronchoepithelial cells in patients with pulmonary fibrosis, and serum cytokeratin 19 fragment is elevated in patients with pulmonary fibrosis. We hypothesized that serum antibodies to cytokeratin 19 may be formed in patients with pulmonary fibrosis. To prove the existence of anti-cytokeratin 19 antibodies in patients' sera, human recombinant cytokeratin 19 was stained with patients' sera by a Western immunoblot. Then, we tried to establish an enzyme-linked immunosorbent assay to quantitate anti-cytokeratin 19 antibody in the sera of patients with idiopathic pulmonary fibrosis (IPF) and pulmonary fibrosis associated with collagen vascular disorders (PF-CVD). We demonstrated the anti-cytokeratin 19 antibody in patient' sera by a Western immunoblot. In patients with IPF and PF-CVD, significantly high anti-cytokeratin 19 antibody was demonstrated compared with normal volunteers, patients with chronic bronchitis, and patients with pneumonia. These results suggest that anti-cytokeratin 19 antibody may have played a role in the process of lung injury in pulmonary fibrosis.

[Asymptomatic pneumatosis cystoides intestinalis in a patient with systemic lupus erythematosus]

Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by the presence of gas-filled cysts in the submucosa or subserosa of gastrointestinal tract. PCI has been widely recognized as a late manifestation of systemic sclerosis but seldom reported to take place in patients with systemic lupus erythematosus (SLE). We reported here a 13-year-old female who had been diagnosed to have SLE based on the following findings; malar rash, discoid erythema, proteinuria, positive antinuclear antibody and anti-DNA antibody. She had been treated with various immunosuppressive drugs including pulse use of corticosteroid, cyclophosphamide and cyclosporin A. She was referred to our hospital because of proteinuria and numbness on her right fifth toe, refractory to above treatment. On admission, the activity of her disease was already low and she had no abdominal symptoms. Plain X-ray film showed multiple round translucencies along the wall of the ascending and transverse colon. Colonoscopy revealed multiple firm-walled cysts distributing in the terminal ileum as well. A diagnosis of PCI was made and she was successfully treated with oral antibiotics and laxatives. The association of PCI with SLE is reviewed briefly.

The concurrent expression of p27(kip1) and cyclin D1 in epithelial ovarian tumors

Mammalian cell-cycle progression is regulated by the combined action of cyclins/cyclin-dependent kinases (cdks) and cdk inhibitors. Abnormal expression as well as interaction of these proteins may result in malignant transformation of cells. To further address alterations and roles of these cell-cycle proteins in the development of epithelial ovarian carcinomas, we analyzed the expression of the p27(kip1), cyclin D1, cyclin E, and cdk2. A panel of 79 epithelial ovarian tumors was selected. Immunohistochemical staining of serial paraffin sections was performed using antibodies to p27(kip1), cyclin D1, cyclin E, and cdk2. The results showed that p27(kip1) and cyclin D1 were concurrently expressed in epithelial ovarian tumors, and the expression was down-regulated in ovarian carcinomas. There was an inverse relationship between the expression level of p27(kip1) and cyclin D1 and the histological tumor grades. On the other hand, the expression of cyclin E and cdk2 was enhanced in ovarian carcinomas. The results suggest that low expression of p27(kip1) and cyclin D1 as well as high expression of cyclin E and cdk2 promotes the development of ovarian tumors. p27(kip1) and cyclin D1 expression are negatively correlated with the malignant degree of epithelial ovarian tumors. Thus, the ovarian tumors with high p27(kip1) and cyclin D1 expression may generally have a somewhat better prognosis, while those with low p27(kip1) and cyclin D1 expression may have a worse prognosis.

The reversible change of GluR2 RNA editing in gerbil hippocampus in course of ischemic tolerance

The ischemic tolerance is known to show protective effects on the neurons and the restricted Ca2+ influx through Ca2+ channels might be involved. In alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor, ribonucleic acid (RNA) editing of the GluR2 subunit determines receptor desensitization and Ca2+ permeability. The authors investigated the effect of ischemic tolerance on the messenger RNA editing of Q/R and R/G sites of GluR2 subunit in hippocampus. It was found that the rate of RNA editing in Q/R site showed no change (100% edited), whereas that in R/G site decreased significantly (83.3% normal editing level to 60.4%) at day 3 (preconditioning period) and returned to normal level at day 14 (after preconditioning period). Further investigation revealed that the decrease of editing rate in ischemic tolerance resulted mainly from the decrease of editing in CA1 area.

Comparison of bioelectrical impedance analysis and dual energy X-ray absorptiometry for assessment of body composition in children

BACKGROUND

There are a variety of methods for assessing body composition. Bioelectrical impedance analysis (BIA) is an easy and non-invasive technique, but has limitations in underweight and overweight subjects. Few reports have investigated the validity of BIA in children. In this report, the characteristics of BIA, especially in overweight and underweight children, are assessed and the results are compared with those of dual energy X-ray absorptiometry (DXA), as a reliable method for assessing body composition.

METHODS

Determination of the fat-free mass (FFM), body fat content and percent body fat (%fat) was carried out using both BIA and DXA. The subjects (60 males and 44 females) were divided into five groups according to the percentage of ideal bodyweight (%IBW). Ten obese children, who were treated with exercise and a low-energy diet for 1 month, were also enrolled in this study.

RESULTS

The %fat, FFM and body fat content showed a close correlation when measured by BIA and DXA with the correlation coefficients being 0.90, 0.95, and 0.95, respectively. In the underweight group, the %fat value determined by BIA tended to be greater than that determined by DXA, while in the overweight group, the BIA value was lower than the DXA value. The same trend was also seen in obese children before and after therapy with exercise and diet.

CONCLUSION

Bioelectrical impedance analysis seems to be a reasonable method for daily clinical use, but attention should be paid to the interpretation of %fat values in underweight and overweight children.

A unique primary structure, cDNA cloning and function of a galactose-specific lectin from ascidian plasma

The complete amino acid sequence of a galactose-specific lectin from the plasma of the ascidian Halocynthia roretzi has been determined by sequential Edman degradation analysis of peptide fragments derived by proteolytic fragmentation and chemical cleavage of the reductive S-pyridylethylated lectin. Peptide fragments were separated by reverse-phase HPLC. The N-terminal and C-terminal amino acid sequences were determined by Edman degradation and enzymatic digestion. The H. roretzi plasma lectin is a single-chain protein consisting of 327 amino acids and four disulfide bonds, one of which was found to be cross-linked intramolecularly. A comparison of the amino acid sequence of the H. roretzi plasma lectin with the sequences of other proteins reveals that the H. roretzi lectin has a structure consisting of a twice-repeated sequence, a fibrinogen-related sequence and a C-type lectin-homologous sequence. The above amino acid sequence was verified by cDNA cloning of this lectin. Three cDNA clones that have single ORFs encoding the lectin precursor were isolated from an H. roretzi hepatopancreas cDNA library. The deduced amino acid sequences in the three cDNA clones contain the same sequence of the mature lectin molecule and the same putative signal sequence. In addition, it was demonstrated that this lectin can enhance phagocytosis by H. roretzi hemocytes. Thus, the plasma lectin is constructed into an oligomer structure via intermolecular disulfide bonds and plays a role in the biological defense of H. roretzi as a defense molecule.

Calbrain, a novel two EF-hand calcium-binding protein that suppresses Ca2+/calmodulin-dependent protein kinase II activity in the brain

A cDNA clone that encodes a novel Ca2+-binding protein was isolated from a human brain cDNA library. The gene for this clone, termed calbrain, encodes a 70-amino acid polypeptide with a predicted molecular mass of 8.06 kDa. The analysis of deduced amino acid sequence revealed that calbrain contains two putative EF-hand motifs that show significantly high homology to those of the calmodulin (CaM) family rather than two EF-hand protein families. By Northern hybridization analysis, an approximate 1.5-kilobase pair transcript of calbrain was detected exclusively in the brain, and in situ hybridization study revealed its abundant expression in the hippocampus, habenular area in the epithalamus, and in the cerebellum. A recombinant calbrain protein showed a Ca2+ binding capacity, suggesting the functional potency as a regulator of Ca2+-mediated cellular processes. Ca2+/calmodulin-dependent kinase II, the most abundant protein kinase in the hippocampus and strongly implicated in the basic neuronal functions, was used to evaluate the physiological roles of calbrain. Studies in vitro revealed that calbrain competitively inhibited CaM binding to Ca2+/calmodulin-dependent kinase II (Ki = 129 nM) and reduced its kinase activity and autophosphorylation.