Development of an animal model for neuroleptic malignant syndrome: heat-exposed rabbits with haloperidol and atropine administration exhibit increased muscle activity, hyperthermia, and high serum creatine phosphokinase level

The neuroleptic malignant syndrome (NMS) is a life-threatening complication of neuroleptic treatment. To elucidate the pathogenesis of NMS, an animal model has been developed. Experimental rabbits treated with haloperidol (1 mg/kg) by intramuscular injection, were studied for the diagnostic symptoms of increased muscle rigidity, elevated body temperature, and high serum creatine phosphokinase (CPK) level. Administration of haloperidol (1 mg/kg) and atropine (0.4 mg/kg), and exposure to high ambient temperature (35°C) induced a significant increase in electromyographic activity with muscle rigidity similar to that observed in patients with NMS. Such rabbits also showed elevated body temperature and serum CPK value. In addition to the similarity of the signs and symptoms, all parameters measured (muscle rigidity, body temperature, and serum CPK level) were normalized by dantrolene treatment. The effectiveness of dantrolene in the experimental animal partially confirms the validity of this animal model for NMS. This experimental animal model for NMS may be useful to elucidate the pathogenesis of NMS.     

Traf6 is essential for murine tooth cusp morphogenesis.

Ectodermal appendages such as skin, hair, teeth, and sweat glands are affected in patients with hypohidrotic (anhydrotic) ectodermal dysplasia (HED). It has been established that mutations in the tumor necrosis factor (TNF) superfamily of molecules, i.e., ectodysplasin (EDA), EDA receptor (EDAR), and EDAR-associated death domain (EDARADD; the intracellular adaptor for EDAR), are responsible for several forms of HED in humans and mice. We show here by in situ hybridisation that another TNF family (orphan) receptor, TROY (also known TAJ, TAJ-alpha, TRADE, and TNFRSF19), is strongly coexpressed with Edar in the epithelial enamel knot signalling centres that are believe to regulate cuspal morphogenesis during murine tooth development. Traf6 is known to function as an intracellular adaptor protein for Troy and examination of Traf6 mutant mice revealed abnormalities in molar teeth that are similar but more severe than those produced by mutations in Eda signalling molecules. This finding suggests that, in additional to ectodysplasin, another TNF pathway involving Troy/Traf6 is involved in molar tooth cusp formation and identifies an essential role for a Traf in tooth development. Developmental Dynamics 229:131-135, 2004.     

Aberrant actin cytoskeleton leads to accelerated proliferation of corneal epithelial cells in mice deficient for destrin (actin depolymerizing factor)

Corneal disease is the most common cause of bilateral blindness in the world. Visual loss in this condition is often due to changes in morphology and function of the corneal epithelial surface. Corneal disease-1 (corn1) and corn1(2J) are spontaneous mouse mutants that develop irregular thickening of the corneal epithelium, similar to that observed in human corneal surface disease. These autosomal-recessive mutations cause an increase in the rate of proliferation of the corneal epithelial cells. Here, we report that the phenotypes in both mutants are caused by mutations within the destrin gene (also known as actin-depolymerizing factor). By positional cloning, we identified a deletion encompassing the entire coding sequence of the destrin gene in corn1 mice, and a point mutation (Pro106Ser) in the coding sequence of destrin in corn1(2J) mice. In situ analysis showed that destrin is highly expressed in the corneal epithelium. Consistent with the cellular roles for destrin, an essential regulator of actin filament turnover that acts by severing and enhancing depolymerization of actin filament, we observed that the corn1 mutations increased the content of filamentous actin in corneal epithelial cells. Our results suggest an in vivo connection between remodeling of the actin cytoskeleton and the control of cell proliferation, and a new pathway through which an aberrant actin cytoskeleton can cause epithelial hyperproliferation.     

The Structural Transformation of Gardenoside and Its Related Iridoid Compounds by Acid and beta-Glucosidase

In the course of studies on the metabolism of iridoid compounds, three new compounds derived from 6alpha-hydroxygeniposide and 6beta-hydroxygeniposide, obtained from gardenoside by the hydrochloric acid treatment, were isolated after the hydrolysis with beta-glucosidase. The aglycone of 6beta-hydroxygeniposide was elucidated as 6beta-hydroxygenipin. On the other hand, the aglycones of 6alpha-hydroxygeniposide were identified as the mixture of stereoisomers, 6alpha-hydroxygenipin and 6alpha-hydroxy-1- EPI-genipin.     

The urinary excretion of pyridinium cross-links as markers of bone metastasis in breast cancer

The collagen cross-links, pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) excreted in urine have recently been suggested as new markers of bone metastasis. In a pilot study we measured Pyr and D-Pyr in 61 patients with breast cancer, 16 with known bone metastasis and 45 with no recognized metastasis in bone. Twenty healthy female subjects were also measured as controls. The mean values (+/-SD) of Pyr and D-Pyr in the group with bone metastasis were significantly higher (Pyr: p<0.01, D-Pyr: p <0.05) than those in the group without bone metastasis and in the control group. The mean (+/-SD) values of postmenopausal women were significantly higher than those of premenopausal in the group without bone metastasis (p<0.05) and in the control group (p<0.01). Therefore, the effect of menopause should be taken into account in the diagnosis of bone metastasis by assays of Pyr and D-Pyr. Setting the cut-off values (mean + 2SD of the values of control) for pre and postmenopausal patients, the accuracy for Pyr was 71.4% in premenopausal and 75.8% in postmenopausal patients; and for D-Pyr it was 71.4% and 78.8% respectively. We consider that measurement of urinary collagen cross-links assays can contribute to the early detection of metastatic spread to bone in breast cancer.     

Effect of a lysyl hydroxylase inhibitor,minoxidil, on ultrastructure and behavior of cultured rabbit subconjunctival fibroblasts

Background: Minoxidil is an inhibitor of lysyl hydroxylase, an enzyme involved in collagen production, and decreases collagen production in vitro. We investigated the in vitro effects of minoxidil on behavior such as proliferation and migration of rabbit subconjunctival fibroblasts (SCFs). The ultrastructural effect of the drug on SCFs was also examined. Methods: Proliferation of SCFs and closure of the defect produced in monolayer cultures in the presence or absence of minoxidil was studied. The ultrastructure of SCFs treated with minoxidil was also examined. Results: Minoxidil inhibited SCF proliferation and the closure of the defect produced in monolayer cell sheets. Ultrastructural observations revealed extensive areas of irregularly dilated endoplasmic reticulum in cells treated with minoxidil, indicating the accumulation of protein, probably underhydroxylated collagen precursors, in the cisternae of endoplasmic reticulum. Conclusions: The results indicated that minoxidil attenuated cellular activities of SCFs such as proliferation and migration in vitro. The exact mechanism of the inhibitory effects of minoxidil on these cellular activities is unknown. The findings suggest that the drug might help to prevent bleb scarring after glaucoma filtering surgery.     

Vergence disorders in patients with spinocerebellar ataxia 3/Machado-Joseph disease: a synoptophore study

Diplopia, a common symptom in spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD) cases, is not always due to asymmetric ophthalmoplegia. We found a Japanese SCA3/MJD family, in which three patients clearly had an impairment of divergence eye movement. We thus quantitatively examined the vergence ranges in eight Japanese SCA3/MJD cases using the synoptophore test. An impairment of the vergence eye movements was found in all patients, and the vergence impairment pattern, but not the ophthalmoplegia pattern, was found to be compatible with the diplopia pattern. The diplopia in SCA3/MJD cases is, therefore, attributed, at least in part, to the impairment of the vergence eye movements.     

Metastasis to the iris in squamous cell lung cancer

A 72-year-old Japanese woman, suffering from squamous cell lung cancer with brain metastasis, underwent 2 courses of combination chemotherapy, consisting of cisplatin and vindesine. Although both the primary tumor and the brain metastasis regressed markedly, she developed left ocular pain with blurred vision. An abnormal mass was found in the left iris, and cytologic examination of the aqueous aspirate revealed a few malignant cells, which, when examined by electron microscopy, were considered to be derived from squamous cell carcinoma of the lung.     

Three-dimensional analysis of benign paroxysmal positional nystagmus in a patient with anterior semicircular canal variant.

OBJECTIVE: To show the positional nystagmus in a patient who had suffered from benign paroxysmal positional vertigo (BPPV) that was thought to be caused by involvement of the anterior semicircular canal (ASCC) (A-BPPV). STUDY DESIGN: Retrospective case report. SETTING: City hospital. PATIENT: The present study reports a rare case of A-BPPV in a 41-year-old woman. CASE REPORT: The patient is 41-year-old woman who developed a positional vertigo after playing volleyball on March 22, 2005 and consulted our hospital the next day. When left Dix-Hallpike maneuver was performed, she showed a positional nystagmus of which fast phase direction of the torsional component was clockwise while that of the vertical component was downward. We plotted the slow phase eye velocity of the positional nystagmus during the left Dix-Hallpike maneuver on three-dimensional coordinates that showed the axis of the positional nystagmus to be perpendicular to the plane of the right ASCC. CONCLUSION: These results suggested that the patient was suffering from A-BPPV.     

Erk pathways negatively regulate matrix mineralization

Skeletal mineralization is an important step regulating the mechanical properties of the calcified tissues, but molecular events underlying mineralization still remain elusive. We examined the role of extracellular signal-regulated kinase (Erk) pathways in matrix mineralization of osteogenic cells both in vitro and in vivo. Matrix mineralization by preosteocytic MLO-A5 cells and osteoblastic MC3T3-E1 cells was increased by either PD98059 Mek inhibitor treatment or adenovirus vector-mediated dominant negative Ras (Ras(DN)) expression and was suppressed by Erk activation by platelet-derived growth factor (PDGF) treatment or constitutively active Mek1 (Mek(CA)) expression. Administration of adenovirus vectors carrying Ras(DN) gene onto the calvaria of 1-day-old mice increased the mineralization of the tissues, while that of the Mek(CA) adenovirus suppressed it. These results suggest that the Erk pathway is a negative regulator of the matrix mineralization both in vitro and in vivo.