The molecular structure of the fastest myosin from green algae, Chara

Chara myosin in green algae, Chara corallina, is the fastest myosin of all those observed so far. To shed light on the molecular mechanism of this fast sliding, we determined the primary structure of Chara myosin heavy chain (hc). It has a motor domain, six IQ motifs for calmodulin binding, a coiled-coil structure to dimerize, and a globular tail. Chara myosin hc is very similar to some plant myosins and has been predicted to belong to the class XI. Short loop 1 and loop 2 may account for the characteristics of mechanochemical properties of Chara myosin.

Canine leptin: cDNA cloning, expression and activity of recombinant protein

Leptin, the product of the ob gene, is one of the key molecules for the regulation of appetite and whole-body energy balance, and thereby for the pathogenesis of obesity. In an attempt to clarify the roles of leptin in obesity and/or related diseases in companion animals, canine leptin c DNA was cloned by amplifying reverse-transcriptase products of RNA extracted from the adipose tissue of the beagle. A c DNA clone of about 3 kbp contained a 501 bp open reading frame coding a 167-amino acid protein with a 21-amino acid signal peptide. The sequence of a 146-amino acid mature leptin was more than 79 per cent identical to those of other mammals. Northern blot analysis revealed abundant expression of leptin m RNA in adipose tissue, but not in other tissues, in adult beagles. When Chinese hamster ovary cells expressing the rat leptin receptor were stimulated with recombinant canine leptin produced by E. coli, some intracellular signal transduction proteins were phosphorylated, indicating that the recombinant leptin was biologically active. The data reported herein will be helpful for further studies of leptin of the dog in health and disease.

Botulinum C3 enzyme changes the lactate dehydrogenase isozyme pattern of primary culture of neurons

Changes in the lactate dehydrogenase (LDH) isozyme pattern of primary culture of neurons treated with botulinum C3 enzyme were examined in order to elucidate the functional changes accompanying the morphological change that follows ADP-ribosylation of Rho protein. Primary neurons were prepared from the cerebrum of ICR mouse embryos on day 15. Neurons were cultured in MEM with 10% fetal calf serum at 37 degrees C. In the neurons treated with C3 enzyme, a typical morphological change was observed after 24 hr, and the LDH isozyme pattern was changed after 72 hr. The ratio of H-subunit to M-subunit in LDH was decreased by C3 treatment, suggesting the induction of a state of lower intracellular oxygen consumption in neurons in the primary cultures.

Mutated human beta3-adrenergic receptor (Trp64Arg) lowers the response to beta3-adrenergic agonists in transfected 3T3-L1 preadipocytes

Wild-type or mutated human beta3-adrenergic receptor (Trp64Arg) cDNAs were stably expressed in mouse 3T3-L1 cells. Saturation binding study using a beta-adrenergic ligand revealed that there was no significant difference in the receptor density and the equilibrium dissociation constant between the two cell lines. However, the ability of the mutant beta3-adrenergic receptor to accumulate cyclic AMP (cAMP) in response to isoproterenol was much reduced and Kact for cAMP accumulation was lowered as compared to the wild type receptor. The amount of alpha subunit of stimulatory GTP-binding protein (GSalpha) and adenylyl cyclase activity in response to forskolin were not different in the two cell lines. The responses of the mutant receptor to epinephrine, norepinephrine and L-755,507, a highly specific agonist for human beta3-adrenergic receptor, were also reduced, but the reduction of Kact for L-755,507 was more evident than other agonists tested. The cAMP accumulation in response to some conventional beta3 agonists was less than 10% of that to isoproterenol even in the cells expressing the wild type receptor. These results suggest that the Trp64Arg mutant beta3-adrenergic receptor has less ability to stimulate adenylyl cyclase, and that lipolytic activity through the beta3-adrenergic receptor by catecholamines in subjects carrying this mutation might be suppressed.

Benign hot bath-related headache

We describe three cases of women with hot bath-related headache who reported that their severe paroxysmal headache could be provoked by pouring hot water over themselves or by soaking in a hot bath. In one patient, the headache was also brought on by exposure to cold wind. Another patient had headaches after she dived into a pool and started swimming. Neurological examination, routine laboratory tests, electroencephalography, and brain imaging showed no abnormality in any of the patients. Hot bath-related headache is a benign headache unassociated with a structural lesion.

Coordinate regulation of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 expression in human vascular smooth muscle cells

The expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) by human vascular smooth muscle cells (SMC) was monitored as a function of the phenotypic modulation in vitro. Cell phenotype was manipulated by varying serum concentration and cell density. Synthetic phenotype was characterized by a minimum expression of the contractile proteins and a maximal proliferation rate. Contractile phenotype was quiescent and expressed a maximal level of contractile proteins. Synthetic cells expressed the highest levels of both MMP-1 and TIMP-1 and displayed maximal collagenolytic activity. No significant change was detected in MMP-2 expression or catalytic activity. Enzyme immunoassays revealed that MMP-1 expression fell by 77+/-2.4-95+/-0.5%, and that of TIMP-1 by 34+/-0.5-59+/-1.9%, as the cells acquired a contractile phenotype. The level of the MMP-1/TIMP-1 complex was similarly reduced by 78+/-2.9-85+/-1.6%. These data demonstrate that the expression of MMP-1 and TIMP-1 are coordinately regulated with SMC phenotype.

Modulation of fas-mediated apoptosis in osteosarcoma cell lines

Fas/APO-1 (or CD95) is a 45-kDa cell surface glycoprotein that transduces cellular death signals for apoptosis upon cross-linking with the Fas ligand, which is experimentally replaced by anti-Fas antibodies. We examined the Fas expression at the protein and mRNA levels, and susceptibility to anti-Fas-mediated apoptosis, in 14 osteosarcoma cell lines. Ten of 14 ostesarcoma cell lines constitutively expressed detectable levels of Fas on the cell surface with positive cell rates ranging from 10.2 to 72.4%. Four other cell lines expressed Fas almost exclusively in the cytoplasm. An antibody against Fas was able to induce Fas-mediated cell death only in two cell lines with high levels of surface Fas. In the presence of the protein synthesis inhibitor cyclohexamide, antibody to Fas led to an induction of apoptosis in ten of the osteosarcoma cell lines antibody-concentration dependently. These data suggest that Fas is a potential protein related to apoptosis in osteosarcomas when the sensitizing activity of cyclohexamide on anti-Fas-mediated cytotoxicity was exerted.

Pineal malignant rhabdoid tumor with chondroid formation in an adult

A pineal tumour in a 27-year-old male is presented with the characteristic histological features of a pineal malignant rhabdoid tumor (MRT) with chondroid formation. Occasionally, tumor cells contained a single well-demarcated hyaline globular inclusion within the cytoplasm adjacent to the nucleus. The stroma of these tumors tends to be densely hyalinized and become chondroid. Immunohistochemical staining was positive for vimentin, epithelial membrane antigen, chromogranin A, synaptophysin, neuron-specific enolase, S-100 protein, and muscle actin. Despite surgery and radiochemotherapy, the tumor recurred in the pineal region and metastasized to the lower lobe of right lung. The patient died 2 years after the initial diagnosis. This is the second published case of central nervous system-MRT appearing in an adult. The clinical and pathological features of pineal MRT in this patient are presented.

Expression of the cyclin-dependent kinase inhibitor, p21Waf-1/Cip-1/Sdi-1, in human vascular smooth muscle cells in the proliferating state

Excess proliferation of vascular smooth muscle cells (SMC) is an important aspect of atherogenesis. Cell-cycle regulatory proteins such as cyclin and cyclin-dependent kinases are vital for cell-cycle progression. To understand the role of the cyclin-dependent kinase inhibitor, p21Waf-1/Cip-1/Sdi-1 (p21Waf-1), on human atherogenesis, we tested p21Waf-1 expression in human atherosclerotic lesions and cultured SMC. Immunohistochemical staining revealed that SMC in neointimal lesions expressed p21Waf-1. No evidence of the p53 protein could be detected. By Western blotting, cultured SMC obtained from a neonate revealed that a higher level of p21Waf-1 expression correlated with a higher expression of proliferating cell nuclear antigen and a lower expression of the contractile protein than that observed in cells obtained from aged donors. When the phenotypes of SMC were changed by modification of serum concentration and cell densities, p21Waf- expression was maximal in serum-stimulated SMC at low cell densities despite the low expression of p53. Furthermore, serum stimulation transiently increased the p21Waf-1 expression of quiescent SMC, which was synchronized with the transition from the G0/G1 to the S phase as well as with cyclin D1 expression. These results may suggest that the negative regulator of cell-cycle progression also plays a role in regulating the appropriate cell-cycle progression in SMC. Growth stimuli may induce both growth-promoting and growth-inhibitory factors in SMC. The balance between these two opposing factors may play an important role in the determination of cell-cycle progression.

Primary amebic meningoencephalitis due to Naegleria fowleri: an autopsy case in Japan

Free-living amebas represented by Naegleria fowleri, Acanthamoeba and Balamutia have been known to cause fatal meningoencephalitis since Fowler and Carter (1965) reported the first four human cases. An autopsy case of a 25-year-old female with primary amebic meningoencephalitis (PAM) due to Naegleria fowleri is described. Headache, lethargy and coma developed in this patient, and her condition progressed to death 8 days after the onset of clinical symptoms. Cerebral spinal fluid examination confirmed clusters of amebas, which were grown in culture and identified as Naegleria fowleri. At autopsy, lesions were seen in the central nervous system (CNS) and the ethmoid sinus. The CNS had severe, suppurative meningoencephalitis with amebic trophozoites mingled with macrophages. This case is the first report of PAM due to Naegleria fowleri in Japan.

Movement velocity dependent muscle strength in Parkinson's disease

We measured isokinetic muscle strength of knee extension and flexion in 18 patients with Parkinson's disease who showed marked laterality in symptom severity and compared strength between the sides in the same patient. In all patient groups, the maximum peak torque of the more affected side was significantly less than for the less affected side at 15 revolutions per minute (r.p.m.) and 30 r.p.m. with the difference between the sides being larger at 30 r.p.m. than at 15 r.p.m., while at 5 r.p.m. there were no significant differences between sides. In the Yahr stage I group, the maximum peak torque in both extension and flexion at each velocity showed no significant difference between the sides. In contrast, in the stage II and III groups the maximum peak torque at 5 r.p.m. showed no significant difference between the sides, while at 15 r.p.m. and 30 r.p.m. these values showed a tendency and a significant difference between the sides, respectively, with the more affected side being weaker. These results suggest that muscle weakness in patients with Parkinson's disease increases with performance velocity, especially as the disease progresses.

A comparison of tau protein in cerebrospinal fluid between corticobasal degeneration and progressive supranuclear palsy

Many clinical and pathological discussions have been focused on the difficulty of differential diagnosis between corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) in recent years. This study was conducted to evaluate the usefulness of tau proteins in cerebrospinal fluid (CSF) for the differentiation of these two diseases. Subjects consisted of 10 patients with CBD (four males and six females with a mean age of 67.9+/-5.8 years), 12 patients with PSP (eight males and four females with a mean age of 62.6+/-5.8 years) and 36 control subjects (CTL) (16 males and 20 females with a mean age of 65.8+/-9.9 years). The CBD group included patients with probable CBD, while all the patients in the PSP group satisfied the diagnostic criteria developed by the National Institute of Neurological Disorders and Stroke and Society for PSP (NINDS-SPSP). CSF tau proteins were measured with the sandwich ELISA method (Innogenetics, Belgium). The CSF tau protein level was 320.1+/-86.5 pg/ml in the CBD group, 151.5+/-52.7 pg/ml in the PSP group and 128.7+/-91.7 pg/ml in the CTL group. Significant differences were noted in tau protein levels between the CBD group and both the PSP group (P<0.001) and the CTL group (P<0.005). We suggested that the measurement of CSF tau proteins may be useful for the differentiation between CBD and PSP.

Fibroblast growth factor-9 (glia-activating factor) stimulates proliferation and production of glial fibrillary acidic protein in human gliomas either in the presence or in the absence of the endogenous growth factor expression

We tested fibroblast growth factor-9 (FGF-9) expression in human glioma cells (U251MG, T98G, U87MG, KALS-1, NMC-G1) and only NMC-G1 expressed endogenous FGF-9. All cells expressed bFGF and high affinity receptors for FGFs (FGFR1 and FGFR3). Exogenously supplied bFGF and FGF-9 both showed mitogenic activities in all cells. Neutralizing antibody against bFGF inhibited the proliferation in U251MG and NMC-G1, however that against FGF-9 inhibited the proliferation only in NMC-G1. GFAP expression was stimulated by both FGFs in these cells. FGF-9 potentially regulates proliferation and GFAP expression in human gliomas either in the presence or in the absence of the endogenous growth factor expression.

Adenovirus-mediated over-expression of p21Waf-1 differentially affects the proliferation, telomerase activity, and expression of glial fibrillary acidic protein in human glioma cells

Over-expression of p21Waf-1 was performed in 5 human glioma cell lines (U251MG, U87MG, T98G, NMC-G1, and KALS-1). p53 gene status was examined by PCR-SSCP and direct sequence method. The endogenous p21Waf-1 expression was evaluated by RT-PCR. Adenovirus-mediated over-expression of p21Waf-1 inhibited the proliferation of human glioma cells expressing wild-type p53 (U87MG, NMC-G1, KALS-1) irrespective of endogenous p21Waf-1 expression. Telomerase activity was also reduced in these cells. In U87MG, GFAP expression was stimulated by the transfection with p21Waf-1, but was reduced in NMC-G1. Over-expression of p21Waf-1 thus affects the cellular behavior of human glioma cells in a cell-type specific manner.

High-signal basal ganglia on T1-weighted images in a patient with Sydenham's chorea

We report a 16-year-old girl with Sydenham's chorea. Choreiform movements involved both sides of her body. MRI 2 months after the onset revealed abnormal increased signal on T2-weighted images and enlargement of the caudate and putamen bilaterally. MRI 5 months later showed resolution of the swelling, but with increased signal on T1-weighted images in the putamen, globus pallidus and the head of the caudate nucleus bilaterally, with slightly increased signal intensity on T2-weighted images.

Cells deleted for Brca2 COOH terminus exhibit hypersensitivity to gamma-radiation and premature senescence

The putative Brca2-MmRad51 interaction is analyzed in mouse cells deleted for the COOH terminus of Brca2 (amino acids 3140-3328), which contains a region that associates with MmRad51 by yeast two-hybrid. These cells are hypersensitive to gamma-radiation (suggesting defective recombinational repair) but not UV light (suggesting intact nucleotide excision repair) and maintain the G1-S and G2-M checkpoints after exposure to gamma-irradiation. Cells deleted for the COOH terminus of Brca2 progress through the cell cycle at a similar rate as wild-type cells but undergo senescence more rapidly. These data support the hypothesis that deletion of Brca2 stimulates cancer by defective MmRad51-mediated DNA repair and not by defective cell cycle regulation.

IL-6 in a pleomorphic type of malignant fibrous histiocytoma presenting high fever

We describe a rare case of pleomorphic type of malignant fibrous histiocytoma (MFH) in the buttock that presented a systemic involvement. The case was of a 58-year-old woman presenting hepatic dysfunction and inflammatory reactions including fever, positive C-reactive protein (CRP), an elevated erythrocyte sedimentation rate, and high levels of platelets and ferritin. The fever of 3 months duration subsided on the first postoperative day. The MFH resection also brought rapid normalization in CRP, platelets, and leukocytes. The local and systemic productions of cytokines induced by this tumor were evaluated. In vivo and in vitro production of interleukin (IL)-6, IL-1beta, and tumor necrosis factor alpha by tumor cells were measured using enzyme-linked immunosorbent assay. Blood samples taken preoperatively, tumor tissues, and the primary culture medium showed extraordinarily high IL-6 levels. The plasma IL-6 level was normalized postoperatively. Immunohistochemistry showed the positivity of tumor cells for IL-6. The IL-6 produced by the tumor was concluded to have been responsible for the systemic illness.

Is IgG anti-GT1a antibody associated with pharyngeal-cervical-brachial weakness or oropharyngeal palsy in Guillain-Barré syndrome?

The pharyngeal-cervical-brachial variant (PCB) of Guillain-Barré syndrome (GBS) has clinical features similar to those of botulism and diphtheria. Mizoguchi et al. (1994) [Mizoguchi, K., Hase, A., Obi, T., Matsuoka, H., Takatsu, M., Nishimura, Y., Irie, F., Seyama, Y., Hirabayashi, Y., 1994. Two species of antiganglioside antibodies in a patient with a pharyngeal-cervical-brachial variant of Guillain-Barré syndrome. J. Neurol. Neurosurg. Psychiatry 57, 1121-1123] reported a patient with PCB-like symptoms who had serum IgG anti-GT1a antibodies which did not cross-react with GQ1b. We assumed that PCB is associated with anti-GT1a antibodies that do not have reactivity to GQ1b and made a serological study of a PCB patient. We searched for PCB patients prospectively and found one with PCB. This patient had IgG anti-GT1a antibodies which were not absorbed with GQ1b in an absorption study, whereas IgG anti-GT1a antibodies from Fisher's syndrome patients were. The frequency of positive IgG anti-GT1a antibody did not differ in patients with and without bulbar palsy. Our findings indicate that IgG anti-GT1a antibodies which do not cross-react with GQ1b are specifically detectable in PCB and can be used as a diagnostic marker of PCB.

Comparison of amino acid sequence of the C-terminal domain of insulin-responsive glucose transporter (GLUT4) in livestock mammals

The nucleotide sequence of cDNA coding the 38-amino acid of the C-terminal domain of insulin-responsive glucose transporter (GLUT4) was determined by the method of reverse transcription-polymerase chain reaction in the sheep, goat and pig, and compared with that of bovine which have been shown to have a unique amino acid conversion of Asn508 to His. The deduced amino acid sequence was completely identical in the three species, and did not have the amino acid conversion at position 508. Western blot analysis confirmed that an antiserum raised against a rat C-terminal peptide cross-reacted efficiently with GLUT4 of these livestock mammals.