A novel class of murine POU gene predominantly expressed in central nervous system

A mouse gene (referred to as Emb) encoding a novel class of POU domain is described. The Emb POU domain shares only 40-50% homology to that of any other POU proteins. Nonetheless, the Emb POU domain can bind to the octamer sequence like other POU domains. Emb is a single-copy gene, located on the distal region of mouse chromosome 15. It is expressed in embryo throughout post-implantation stages, where the most prominent expression is seen in developing central nervous system. In the adult, it is highly expressed in brain, whereas weaker expression can be detected in other organs such as testis, skeletal muscle, and kidney. The expression in adult brain is most evident in neurons of hypocampus formation. Two types of Emb mRNA are expressed in brain; one type encodes a protein of 301 amino acids residues, whereas the other codes for a protein with two extra amino acids residues added at the amino-terminal end of POU domain. These two mRNA species are generated by alternative splicing by utilizing an unusual splice acceptor site: CCTCCCTCTG/. Emb mRNA expressed in testis, on the other hand, encodes a smaller protein lacking most of the amino-terminal region.

A mutation in the Pax-6 gene in rat small eye is associated with impaired migration of midbrain crest cells

The rat small eye strain (rSey) lacks eyes and nose in the homozygote, and is similar to the mouse Sey strain with mutations in the Pax-6 gene. We isolated Pax-6 cDNA clones from an rSey homozygote library, and found an internal deletion of about 600 basepairs in the serine/threonine-rich domain. At the genomic level, a single base (G) insertion in an exon generates an abnormal 5' donor splice site, thereby producing the truncated mRNA. Anterior midbrain crest cells in the homozygous rSey embryos reached the eye rudiments but did not migrate any further to the nasal rudiments, suggesting that the Pax-6 gene is involved in conducting migration of neural crest cells from the anterior midbrain.

Cooperative activation of Chox-4 homeobox genes by factors from the polarizing region and the apical ridge in chick limb morphogenesis

When a mouse zone of polarizing activity (ZPA) at the posterior margin of the limb bud was grafted at the anterior margin of the chick limb bud, we found that expression of the chick homeobox genes, Chox-4.7 and -4.8, was induced prior to the formation of chick extra digits. The induction was observed in the restricted domain close to both grafted mouse ZPA and the chick apical ectodermal ridge (AER). When the posterior half of the AER was removed, the normal expression was diminished in the posterodistal region. Thus, it is likely that at least two distinct factors, one from the ZPA and the other from the AER, provide positional information to induce cooperatively the sequential expression of the Chox-4 genes.

Expression pattern of the activin receptor type IIA gene during differentiation of chick neural tissues, muscle and skin

To elucidate target cells of activins during embryogenesis we isolated cDNAs of chick activin receptor type II (cActR-II) and studied expression patterns of the cActR-II gene by in situ hybridization. Transcripts of cActR-II were observed in neuroectoderm developing to spinal cord, brain and eyes, in surface ectoderm differentiating to epidermis, and in myotomes differentiating to muscles. The expression patterns of cActR-II suggest that activin and its receptor are involved in differentiation of chick neural tissues, muscle and skin after inducing the dorsal mesoderm.

Social desirability and irritable bowel syndrome

The Marlowe-Crowne Social Desirability Scale, a 33-item self-report questionnaire, was administered to an age-matched sample of twenty-five irritable bowel syndrome (IBS) patients, twenty-four psychiatric patients meeting a diagnosis of major depression, and nineteen controls. As predicted, planned comparisons analysis showed a significant group effect: IBS group scores were significantly higher than both depressed and control group scores (p less than .05). Implications of this social desirability response set for the psychological assessment and treatment of IBS are discussed.

Morphogenetic Roles of Retinoic Acid

We integrated our information on morphogenetic roles of retinoic acid, focusing on development of chick limb. Retinoic acid has been considered to be a putative morphogen released from the ZPA. However, since exogenous retinoic acid induces expression of RAR beta, but not grafted ZPA, the ZPA is unlikely to produce retinoic acid. From the result that retinoic acid-treated cells induce digit duplication, retinoic acid converts anterior cells into ZPA cells. We found that retinoic acid also induces expression of homeobox genes indirectly and that bFGF enhances expression of the homeobox genes. Thus, we considered that retinoic acid and growth factors cooperate with each other to activate homeobox genes. A morphogenetic role of retinoic acid is to coordinate developmental stage of each cells by controlling expression of homeobox genes.

Differential expression of two MSH-related homeobox genes Chox-7 and Chox-8 during chick limb development

We have isolated two closely related cDNAs, Chox-7 and Chox-8, encoding homeodomain-containing proteins homologous to Drosophila msh. The Chox-7 and Chox-8 genes are chicken cognates of mouse Hox-7.1 and Hox-8.1, respectively. In situ hybridization using 3' regions of the cDNAs as probes revealed that the Chox-7 gene is highly expressed in the mesenchyme subjacent to the apical ectodermal ridge whereas Chox-8 expression is localized in the anterodistal mesenchymal region at early stages of limb formation, suggesting different roles during limb development. At later stages, both genes are expressed in the anterior and posterior mesenchymes and in the interdigital mesenchyme where programmed cell death occurs.

Involvement of retinoic acid and its receptor beta in differentiation of motoneurons in chick spinal cord

Retinoic acid is known to play an important role during development of central nervous system. In order to clarify function of retinoic acid during the development, we investigated expression pattern of the chick retinoic acid receptor subtype beta gene by an in situ hybridization method. We found that expression of the beta gene is localized in neural tube at stages 16-20, then is turned to be restricted to developing motoneurons at stages 23-29. These results suggested that retinoic acid and its receptor beta are involved in differentiation of the motoneurons in spinal cord.

A random walk method for percutaneous drug absorption pharmacokinetics: application to repeated administration of a therapeutic timolol patch

A random walk method for predicting percutaneous drug absorption pharmacokinetics was proposed. The profiles predicted by this method were compatible with those predicted by the analytical method. The random walk method is particularly useful for predicting complex processes such as repeated topical application of a drug. The amount of a drug released into skin from four therapeutic timolol patches was measured when the patches were serially applied for 2.5 h each on the same site of six healthy male volunteers. On the average, 33.2, 23.4, 15.1, and 16.5% of the applied dose was released into skin from the first, second, third, and fourth patches, respectively. This pattern was comparable with the predicted profiles (43.9, 30.2, 24.4, and 21.1%) of amounts of drug which were expected to be released from the first to fourth patches into skin, respectively. The estimation method for the normalized skin-capillary boundary clearance is also described and applied in examining the percutaneous absorption of timolol. The estimated value for this parameter was much greater than the diffusion parameter, indicating that the removal process of timolol by the local circulation is much faster than the diffusion process through skin.

Prevention of Postanesthetic Shivering with Intravenous Administration of Aspirin

There have been many reports of postanesthetic shivering (PAS); however, the causes have not been defined clearly, and the reported methods of inhibiting PAS are not always available clinically. In the present study, we assessed the effect of the intravenous administration of aspirin on the prevention of PAS in 62 patients undergoing oral or maxillofacial surgery, anesthetized with enflurane-nitrous oxide. Thirty of the patients were randomly selected, and received intravenous aspirin DL-lysine 900 mg (equivalent to aspirin 495 mg) before the end of surgery. No significant differences were noted in the rectal temperatures between the group given aspirin and the control group. Shivering was observed in 17 of the 32 patients of control group. In contrast, shivering was observed in 5 of the 30 patients who received aspirin. This was a statistically significant difference ( P < 0.01). These data indicate that intravenous administration of aspirin significantly inhibited PAS. The finding suggests that PAS is related to prostaglandin synthesis or to the formation of derivatives of arachidonic acid, since aspirin inhibits both the synthesis of prostaglandins and the formation of derivatives of arachidonic acid.

Skin irritation induced by topically applied timolol

1. Erythema induced by topically applied timolol, a non-selective beta-adrenoceptor blocker, was assessed in six male volunteers. Intensity of erythema developed on the inner surface of the left forearm where timolol free base was applied for 10 h was measured by a visual score, laser doppler flowmeter and reflectance spectrophotometry. Plasma timolol concentrations collected from the left and right arms were also measured. 2. The mean values for blood volume and blood flow per unit volume of tissue both of which were assessed by a laser doppler flowmeter, haemoglobin index measured by reflectance spectrophotometry, and magnitude of erythema graded by a visual score significantly increased after the application of an acrylic co-polymer adhesive patch containing 20% (w/v) timolol free base. 3. Plasma timolol concentrations collected from the left antecubital vein were 2.4 to 10.7 times greater than those from the right arm and had significant correlations (rs = 0.55 to 0.76) with the parameters indicating the extent of erythema developed where a patch containing timolol was applied. 4. The inter-individual variation of timolol was attributed to that of the diffusivity of timolol through skin rather than that of the skin reactivity to topically applied timolol because the plasma timolol concentrations drawn from the left arm in the subjects who did not develop erythema were very low.(ABSTRACT TRUNCATED AT 250 WORDS)

Involvement of the Chox-4 chicken homeobox genes in determination of anteroposterior axial polarity during limb development

We have isolated and identified four chicken homeobox genes in the upstream region of the Chox-4 complex. The Chox-4g and -4f genes, at the 5' extremity of the complex, were expressed locally in the vicinity of the zone of polarizing activity (ZPA) at early stages of limb development, substantiating the involvement of the genes in anteroposterior axis determination. To confirm their function, we implanted a bead containing retinoic acid, or the ZPA itself, in the anterior margin of the limb bud, leading to formation of mirror-image duplicated digits, and observed the resultant change in gene expression. Expression of the Chox-4g and -4f genes was induced in the new digit-forming region. Those results suggest that positional information assigned by a ZPA morphogen is imprinted on cellular memory by expression of the Chox-4 genes to maintain positional signaling along the anteroposterior axis in the limb field.

Bacterial endotoxin-induced expression of metallothionein genes in rat brain, as revealed by in situ hybridization

In order to clarify acute-phase response in brain, we investigated induction of metallothionein (MT) genes by administrating an endotoxin (lipopolysaccharide) in rat intraperitoneum. We performed in situ hybridization on the serial brain sections to identify the cells expressing the MT genes in acute-phase. After endotoxin administration, transcripts of MT genes were detected in the arachnoideal, ependymal cells and glial cells around the Purkinje cells of the cerebellum, while no significant induction of the MT genes by zinc ion was observed in brain. These results suggest that the acute-phase response occurs specifically in at least these 3 non-neuronal cells.

Retinoic acid induces polarizing activity but is unlikely to be a morphogen in the chick limb bud

Retinoic acid is a putative morphogen in limb formation in the chick and other vertebrates. In chick limb formation, it is thought that retinoic acid is released from the zone of polarizing activity (ZPA) and the concentration gradient of retinoic acid formed from the posterior to the anterior provides positional cues for digit formation. Implantation of a bead containing retinoic acid at the anterior margin of the limb bud induces a mirror-image symmetrical duplication of the digit pattern similar to that observed when the ZPA is grafted into the anterior margin of the host limb bud. Also, the level of endogenous retinoic acid (25 nM on average) is higher in the posterior one third of the limb bud. We found that when the bead containing either retinoic acid or an analogue but not the ZPA, was implanted in the anterior margin of the chick limb bud, expression of the retinoic acid receptor type-beta gene was induced around the bead within 4 h. These results indicate that exogenous retinoic acid is not identical with the ZPA morphogen. As the anterior tissue exposed to retinoic acid has polarizing activity, we conclude that the primary function of exogenous retinoic acid is to induce polarizing activity in the limb bud.

Diurnal regulation of per repeat mRNA in the suprachiasmatic nucleus in rat brain

'Per repeat is a rodent genomic DNA fragment which is homologous to the Gly-Thr repetitive amino acid sequence of the Drosophila clock gene period'. This study examined the temporal and spatial expression of the per repeat mRNA in rat brain. Northern blot analysis showed that the level of per repeat mRNA species fluctuates under light-dark cycle conditions in rat brain. Furthermore, the fluctuation of per repeat mRNA was clearly observed in the suprachiasmatic nucleus, but not so in other regions including the hippocampus as shown by in situ hybridization. The above results suggest that the Gly-Thr repetitive sequence also plays an important role in the circadian rhythm of mammals.

Expression of hepatocyte growth factor gene in endothelial and Kupffer cells of damaged rat livers, as revealed by in situ hybridization

Hepatocyte growth factor (HGF) has been demonstrated to be synthesized and secreted by non-parenchymal liver cells for liver regeneration after hepatic injury. We performed in situ hybridization to identify HGF-producing cell types in rat liver hepatitis induced by administrating carbon tetrachloride as a hepatotoxin. We found that transcripts of the HGF gene are localized in the Kupffer and endothelial cells in normal livers and increased remarkably in the Kupffer cells of the damaged livers. Thus, HGF is concluded to be synthesized in the Kupffer and endothelial cells to repair the liver tissue in paracrine fashion. No significant increase in the transcripts of the HGF gene was observed in livers after partial hepatectomy, indicating that a mechanism on liver regeneration after the hepatectomy differs from that on liver repairs. Since the HGF gene expression was also found in lung and kidney, HGF may be a ubiquitous factor for tissue repairs.

Expression of retinoic acid receptor genes in neural crest-derived cells during mouse facial development

Retinoic acid (RA) is known as a teratogen that induces abnormalities in facial structures which are made up mainly of neural crest-derived mesenchyme. We investigated expression patterns of RA receptor (RAR) genes (subtypes alpha, beta, gamma) during mouse facial development. The expression of the RAR beta gene is specific for the mesenchyme around developing eyes and nose, whereas the RAR gamma gene is expressed in the mesenchyme differentiating to facial cartilages and bones. In contrast, the RAR alpha gene is expressed weakly and uniformly over the facial region. These results suggest that crucial roles of endogenous RA in facial development depend on differential functions of the RAR subtypes.

Expression pattern of acidic and basic fibroblast growth factor genes in adult rat eyes

Although the retinal angiogenic and mitogenic factors have been identified to be acidic and basic fibroblast growth factors (aFGF and bFGF), little information has so far been available about the cells producing them and their function in retinal tissues. We found, by in situ hybridization, that the expression pattern of the aFGF gene differed remarkably from that of the bFGF gene in adult rat eyes. Our results demonstrated that the aFGF gene was produced by photoreceptor visual cells, neuronal cells in the inner nuclear layer and ganglion cells of the retina, in addition to pigment epithelial cells of the choroid, iris and ciliary body, and epithelial cells of the cornea, conjunctiva and lens, while bFGF was synthesized solely by the photoreceptor visual cells.

Expression of retinoic acid receptor genes in keratinizing front of skin

We found, by an in situ hybridization method with riboprobes synthesized from human cDNA of the retinoic acid receptor (RAR), that the RAR genes (predominantly gamma-subtype) are intensively expressed in the epidermis of normal and psoriasic human skins, and also in keratinizing fronts of 4-day-old mouse skins, nail matrices and hair follicles. Thus, target cells of retinoic acid in the skins are concluded to be keratinocytes, which is quite consistent with the fact that retinoic acid regulates keratinization of epidermis in vivo and also modulates expression of the keratin gene in vitro.

Spatial and temporal expression pattern of retinoic acid receptor genes during mouse bone development

Spatial and temporal expression pattern of retinoic acid receptor (RAR) genes was investigated in mouse finger bones during development by an in situ hybridization method with riboprobes synthesized from a human cDNA of the RAR-alpha. We found that the RAR genes are expressed intensively and specifically in calcifying fronts of the mouse finger bones, whereas the expression pattern is rather uniform in the limb buds and cartilage matrices of the embryonic fingers. Our findings are consistent with the fact that vitamin A is essential for normal mammalian bone development.

[Localization of epidermal growth factor and nerve growth factor mRNAs in mouse submandibular gland by a simplified in situ hybridization with riboprobes]

We simplified procedures of in situ hybridization with riboprobes on serial sections of paraffin-embedded tissues. We found that when tissues were fixed with 4% paraformaldehyde, embedded in paraffin, and cut serial sections with 5 microns thick, excellent results were obtained without proteolytic, heat, or HCl treatment. With our simplified method, both EGF and NGF mRNAs were detected intensively and specifically in granular convoluted tubule (GCT) cells of a male mouse submandibular gland, but not detected in either the acini or ducts other than the GCT. Accumulation of the silver grains was localized in the basal side of the GCT cells. No significant hybridization was observed in those cells with the sense probe and in the parotid and sublingual gland even with the anti-sense probe. Since our results were not only very consistent with other data, but also much more excellent than other results obtained by in situ hybridization on the similar tissues, our simplified method should be very useful to study gene expression on tissue sections.

Simultaneous determination of four monoamine metabolites and serotonin in cerebrospinal fluid by "high-performance" liquid chromatography with electrochemical detection; application for patients with Alzheimer's disease

We describe an optimized, sensitive assay procedure for simultaneously determining 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxyphenylacetic acid, and serotonin in human lumbar cerebrospinal fluid. The assay is based on liquid chromatography with an electrochemical detection system equipped with a newly developed, highly sensitive graphite electrode. Before assay, samples are deproteinized with perchloric acid, 0.2 mol/L. The within- and between-day CVs were less than 2.5% and 6.7%, respectively, for all compounds. The lower limits of detection for 3-methoxy-4-hydroxyphenylglycol and 3,4-dihydroxyphenylacetic acid were 0.5 pg and for the other three analytes 1.5 pg per injection. Preliminary data on monoaminergic metabolites by the current assay showed that concentrations of dopaminergic and serotonergic metabolites were significantly (P less than 0.05) lower in patients with Alzheimer's disease than in the age-matched controls. In addition, the concentration of 3,4-dihydroxyphenylacetic acid correlated significantly (P less than 0.01) with that of homovanillic acid, suggesting that monitoring either of these metabolites in cerebrospinal fluid can be used as an index of central dopaminergic activity.

Simultaneous determination of four monoamine metabolites and serotonin in cerebrospinal fluid by "high-performance" liquid chromatography with electrochemical detection; application for patients with Alzheimer's disease

We describe an optimized, sensitive assay procedure for simultaneously determining 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxyphenylacetic acid, and serotonin in human lumbar cerebrospinal fluid. The assay is based on liquid chromatography with an electrochemical detection system equipped with a newly developed, highly sensitive graphite electrode. Before assay, samples are deproteinized with perchloric acid, 0.2 mol/L. The within- and between-day CVs were less than 2.5% and 6.7%, respectively, for all compounds. The lower limits of detection for 3-methoxy-4-hydroxyphenylglycol and 3,4-dihydroxyphenylacetic acid were 0.5 pg and for the other three analytes 1.5 pg per injection. Preliminary data on monoaminergic metabolites by the current assay showed that concentrations of dopaminergic and serotonergic metabolites were significantly (P less than 0.05) lower in patients with Alzheimer's disease than in the age-matched controls. In addition, the concentration of 3,4-dihydroxyphenylacetic acid correlated significantly (P less than 0.01) with that of homovanillic acid, suggesting that monitoring either of these metabolites in cerebrospinal fluid can be used as an index of central dopaminergic activity.

Vascular loops in internal auditory canal as possible cause of Menière's disease

Vascular loops were found in 2 patients diagnosed clinically as having Ménière's disease. A vascular loop was suspected of being present within the internal auditory canal in another patient who complained of tinnitus and vertigo. Diagnosis was performed by air CT cisternography in the former patients and by CT with contrast enhancement in the latter patient. In Case No. 1, the attacks of vertigo disappeared after endolymphatic sac decompression. In Case No. 2, hearing loss progressed despite remission of vertigo. In Case No. 3, the patient had only tinnitus and dizziness. Although it was difficult to definitely conclude that there was a causal relationship between the vascular loop and the clinical symptoms, we felt that there was a need to investigate the vascular loop as a possible cause of vertigo, tinnitus, and progression of sensorineural hearing loss.