KORRIGAN, an Arabidopsis endo-1,4-beta-glucanase, localizes to the cell plate by polarized targeting and is essential for cytokinesis

The formation of the cell plate, a unique structure in dividing plant cells, is pivotal for cytokinesis. A mutation in the Arabidopsis KORRIGAN (KOR) gene causes the formation of aberrant cell plates, incomplete cell walls, and multinucleated cells, leading to severely abnormal seedling morphology. The mutant, designed kor1-2, was identified as a stronger allele than the previously identified kor1-1, which appears to be defective only in cell elongation. KOR1 encodes an endo-1,4-beta-d-glucanase with a transmembrane domain and two putative polarized targeting signals in the cytosolic tail. When expressed in tobacco BY2 cells, a KOR1-GFP (green fluorescence protein) fusion protein was localized to growing cell plates. Substitution mutations in the polarized targeting motifs of KOR1 caused the fusion proteins to localize to the plasma membrane as well. Expression of these mutant genes in kor1-2 plants complemented only the cell elongation defect but not the cytokinesis defect, indicating that polarized targeting of KOR1 to forming cell plates is essential for cytokinesis. Our results suggest that KOR1 plays a critical role during cytokinesis.

KORRIGAN, an Arabidopsis endo-1,4-beta-glucanase, localizes to the cell plate by polarized targeting and is essential for cytokinesis

The formation of the cell plate, a unique structure in dividing plant cells, is pivotal for cytokinesis. A mutation in the Arabidopsis KORRIGAN (KOR) gene causes the formation of aberrant cell plates, incomplete cell walls, and multinucleated cells, leading to severely abnormal seedling morphology. The mutant, designed kor1-2, was identified as a stronger allele than the previously identified kor1-1, which appears to be defective only in cell elongation. KOR1 encodes an endo-1,4-beta-d-glucanase with a transmembrane domain and two putative polarized targeting signals in the cytosolic tail. When expressed in tobacco BY2 cells, a KOR1-GFP (green fluorescence protein) fusion protein was localized to growing cell plates. Substitution mutations in the polarized targeting motifs of KOR1 caused the fusion proteins to localize to the plasma membrane as well. Expression of these mutant genes in kor1-2 plants complemented only the cell elongation defect but not the cytokinesis defect, indicating that polarized targeting of KOR1 to forming cell plates is essential for cytokinesis. Our results suggest that KOR1 plays a critical role during cytokinesis.

Myasthenia gravis with membranous nephropathy, successfully treated with extended total thymectomy

A 46-year-old woman showed proteinuria and hematuria after left blepharoptosis, and revealed a histopathology of membranous nephropathy (MN) at renal biopsy. She was diagnosed as having myasthenia gravis (MG) because of a positive edrophonium test and anti-acetylcholine receptor (AchR) antibodies in serum. We found a decrease in anti-AchR antibodies after extended total thymectomy, in parallel with an improvement in both urinary findings and myasthenic symptoms. In this case, MG preceded MN and the thymectomy was effective for both diseases, suggesting that the thymus might play an important role in the pathogenesis of MN.

Inner ear abnormalities in Kabuki make-up syndrome: report of three cases

Three patients, a female and two males, 28, 15, and 14 years of age, with Kabuki make-up syndrome (KMS) were studied for middle and inner ear abnormalities by using CT scanning of the petrous bones. All three patients had bilateral dysplasia of the inner ear, i.e., hypodysplasia of the cochlea, vestibule, and semicircular canals (so-called Mondini dysplasia), whereas their middle ears had no abnormalities. Audiometry demonstrated a sharp decrease in hearing of the high tone range, bilateral in one and unilateral in another, while the third patient was noncooperative. In view of these findings, it would be advisable to study each individual with KMS and hearing impairment for possible inner ear abnormalities.

Induction of oxidatively modified proteins in skeletal muscle by electrical stimulation and its suppression by dietary supplementation of (-)-epigallocatechin gallate

The oxidative stress produced by electrical stimulation-induced muscle contraction was examined in the skeletal muscle proteins of rats that had been fed on the dietary flavonoid, (-)-epigallocatechin gallate (EGCg). Electrical stimulation of the rat leg muscle every second day for a two-week period resulted in an increased (p < 0.05) muscle weight and accumulation of oxidatively induced modified proteins. Similar stimulation conducted every day for only one week had no effect on the muscle weight or protein oxidation, although the rate of protein degradation increased. Rats fed on a 20% casein diet supplemented with 0.1% EGCg for 2 weeks responded to the electrical stimulation of muscle contraction by reducing the increased muscle protein carbonyl content when compared to their counterparts fed on a control diet. There was no change in activity of antioxidative enzymes in muscle tissue of the EGCg-fed rats receiving electrical stimulation. The results of this study show that the antioxidative property of EGCg was effective for suppressing oxidative modification of the skeletal muscle protein induced by electrical stimulation. This finding demonstrates that EGCg has a beneficial effect in vivo on the free radical-mediated oxidative damage to muscle proteins.

The effect of ketamine isomers on both mice behavioral responses and c-Fos expression in the posterior cingulate and retrosplenial cortices

Ketamine, a non-competitive NMDA receptor antagonist, is a racemic mixture. S(+) ketamine is presumed to be more potent as an anesthetic than R(-) ketamine, and causes less postanesthetic stimulation of locomotor activity than R(-) ketamine in animals at equihypnotic doses. In the present study, we investigated the effect of S(+), R(-), and racemic ketamines on mice behavioral responses and c-Fos expression in the posterior cingulate and retrosplenial cortices (PC/RS), which are suggested to be the brain regions responsible for NMDA-receptor-antagonist-induced psychotomimetic activity. Ataxia and head weaving and c-Fos expression in the PC/RS were significantly more induced by both S(+) and racemic ketamines than by R(-) ketamine at the same dose. S(+) ketamine induced significantly more potent ataxia than racemic ketamine at the same dose. Ketamine-induced c-Fos expression in the PC/RS correlated well with the intensity of behavioral responses. These results imply that R(-) ketamine is weaker than both S(+) and racemic ketamines in a psychotomimetic effect. Also, S(+) ketamine is more potent than racemic ketamine in a psychotomimetic effect and possibly in an anesthetic effect. They also indicate that PC/RS is at least one of the specific brain regions responsible for ketamine-induced behavioral responses in animals and a psychotomimetic activity in humans.

Polypeptide compositions and NH2-terminal amino acid sequences of proteins in foxtail and proso millets

Seed protein of foxtail and proso millets were fractionated into polypeptides that were analyzed for their major protein, prolamin, and the NH2-terminal amino acid sequences of the proteins were determined. The proteins extracted from foxtail and proso millets were 64.1% and 80.0% prolamin, respectively. The polypeptides of the prolamins were classified into two groups. The major polypeptides of 27-19 kDa were rich in leucine and alanine, whereas the 17-14 kDa polypeptides were rich in methionine and cysteine. Glutelin-like proteins that were extracted with a reducing reagent were high in proline content, the major polypeptides being 17 and 20 kDa. The NH2-terminal amino acid sequence showed that the major polypeptides of prolamin were homologous to alpha-zein and a glutelin-like protein containing the Pro-Pro-Pro sequence, like the repetitive sequence of gamma-zein. Although the prolamin consisted of a similar subunit to that of zein, polypeptides with various pI values were found among them.

Apelin, the natural ligand of the orphan receptor APJ, is abundantly secreted in the colostrum

By using a strategy that we have developed to search for the ligands of orphan seven-transmembrane-domain receptors [S. Hinuma et al., Nature 393 (1998) 272-276], we have recently identified a natural ligand, apelin, for the orphan 7TMR, APJ [K. Tatemoto et al., Biochem. Biophys. Res. Commun. 251 (1998) 471-476]. In this paper, we isolated rat and mouse apelin cDNAs, and analyzed the tissue distribution of apelin mRNA in rats. Although apelin mRNA was widely detected in a variety of tissues, the highest expression of apelin mRNA was detected in the mammary gland of pregnant rats. In the mammary gland, biologically active apelin and its mRNA considerably increased during pregnancy and lactation, and reached a maximal level around parturition. Moreover, a large amount of apelin (14-93 pmol/ml) was found to be secreted in the bovine colostrum, and it was still detectable even in commercial bovine milk. Since apelin partially suppressed cytokine production by mouse spleen cells in response to T cell receptor/CD3 cross-linking, the oral intake of apelin in the colostrum and milk might modulate immune responses in neonates.

[Primary ciliary dyskinesia treated with living-donor lobar lung transplantation]

We report a case of primary ciliary dyskinesia in which a living-donor lobar lung transplant was performed. A 24-year-old woman with a diagnosis of primary ciliary dyskinesia and bronchiectasis was admitted to Shinshu University Hospital because of persistent dyspnea and pyrexia over a period of 4 months. Although she was given various antibiotics, neutrophilia, elevated plasma C-reactive protein (CRP) levels, and respiratory failure persisted. Chest roentgenograms and computed tomography disclosed severe bronchiectasis and diffuse infiltrative shadows in both lung fields. Pseudomonas aeruginosa was detected in a sputum culture. Although a variety of conventional therapies were administered, the patient's oxygenation progressively deteriorated. She was intubated and assisted by mechanical ventilation. The patient and her family proposed lung transplantation, and we concluded that a living-donor lobar lung transplant would be a suitable treatment for her disease. We transported the patient to Okayama University Hospital by helicopter 10 days after intubation. A living-donor lobar lung transplant was successfully performed with lung tissues donated by the patient's mother and sister for each transplant site.

Lung cancer incidence rates by histologic type in high- and low-risk areas; a population-based study in Osaka, Okinawa, and Saku Nagano, Japan

We investigated lung cancer incidence by histologic type using the data from population-based cancer registries in high-risk (Osaka and Okinawa) and low-risk (Saku Nagano) areas. Since the proportion of cases with histologic types identified was not sufficiently high, sex- and age-specific incidence rates by histologic type were estimated assuming that the distribution of histologic types was the same across the same sex and age groups regardless of reporting status. Compared to Saku in Nagano Prefecture, the cumulative risk of lung cancer incidence rates in Osaka and Okinawa were 1.3 and 1.5 times higher for males and 1.3 and 1.2 times higher for females, respectively. When divided by histologic type, male adenocarcinoma and small cell carcinoma were 1.6-2.1 times higher in Osaka and Okinawa, while squamous cell carcinoma was 1.6 times higher only in Okinawa compared to Saku Nagano. In females, squamous cell carcinoma and small cell carcinoma were 2.5-3.3 times higher in Osaka and Okinawa compared to Saku Nagano, while adenocarcinoma was almost equal in the 3 areas. These results indicate that the pattern of incidence of lung cancer by histologic type may differ between high- and low- risk areas.

Enhancing effect of dietary vinegar on the intestinal absorption of calcium in ovariectomized rats

We studied the effect of dietary vinegar on calcium absorption by using ovariectomized rats fed on a low-calcium diet. The apparent absorption of calcium was higher when the rats were fed on a diet containing 1.6% vinegar for 32 days than when fed on a diet without vinegar (P < 0.05). The calcium content in the femur of the rats given diets containing 0.4% and 1.6% vinegar were also higher (P < 0.05). The serum parathyroid hormone level was lower and the crypt depth of the duodenum thicker in the rats fed on a diet containing 1.6% vinegar (P < 0.05). These results suggest that dietary vinegar enhanced intestinal calcium absorption by improving calcium solubility and by the trophic effect of the acetic acid contained in vinegar, which would reduce the bone turnover caused by ovariectomy and be helpful in preventing osteoporosis.

Myofibrillar protein catabolism is rapidly suppressed following protein feeding

The immediate response of protein degradation to food intake and the factors for its regulation in rat skeletal muscle were examined. The concentration of N tau-methylhistidine (MeHis) in serum and the rates of MeHis release from isolated soleus and extensor digitorum longus muscles were reduced in the period from 3 to 6 h after refeeding, indicating that the rate of myofibrillar protein degradation in the rat decreased immediately after refeeding. Changes in the serum concentration of insulin and corticosterone were not synchronized with those in the myofibrillar protein degradation. When rats were fed on a protein-free diet, no reduction of serum MeHis concentration or of the rate of MeHis release from isolated muscles after refeeding was apparent. Furthermore, there was a tendency toward suppressing myofibrillar protein degradation with a higher protein content of the diet. These results suggest that the suppression of myofibrillar protein degradation by food intake was regulated by dietary proteins.

A fiberscopic analysis of velopharyngeal movement before and after primary palatoplasty in cleft palate infants

There have been few studies done on the abnormal function of velopharyngeal muscles in unrepaired cleft palate infants. To examine and assess velopharyngeal movement before primary palatoplasty offers supposedly any valuable information for the successful operation and the restoration of excellent velopharyngeal function. We designed to investigate and analyze velopharyngeal movement before and after primary palatoplasty in 26 cleft palate infants with a fine nasopharyngeal fiberscope. We found three different patterns of velopharyngeal movement in unrepaired cleft palate infants when crying or strangulation reflex occurred: (1) posterior movement type (10 cases, 38.5 percent), where the soft palates moved only posteriorly and cephalically and did not move medially; (2) medial movement type (10 cases, 38.5 percent), where the soft palates moved only medially and did not move posteriorly or cephalically; and (3) posteromedial movement type (6 cases, 23.0 percent), where the soft palates moved both posteriorly and cephalically as well as medially. Postoperative velopharyngeal closure was classified into three patterns: (1) the soft palate type, in which the soft palate mainly operates; (2) the lateral wall type, in which compensational medial movement of the lateral pharyngeal wall is mainly observed; and (3) the mixed type, in which both the soft palate and the lateral pharyngeal wall operate. Also, we demonstrated a close relationship between velopharyngeal movement before and after primary palatoplasty in cleft palate infants. In total, 10 of 16 cleft palate infants with the posterior movement type or posteromedial movement type, in which posterior movement of the soft palates was observed before primary palatoplasty, postoperatively showed the soft palate type of velopharyngeal closure. On the other hand, only 2 of 10 cleft palate infants with the medial movement type, in which the soft palates did not move posteriorly but medially before primary palatoplasty, postoperatively showed the soft palate type of velopharyngeal closure. The Fisher's exact probability test clarified that cleft palate infants with the posterior movement type or posteromedial movement type were more likely to show postoperatively the soft palate type of the velopharyngeal closure compared with those with the medial movement type (p = 0.051). This is the first trial to examine velopharyngeal movement in unrepaired cleft palate infants. Our findings indicate the probability that velopharyngeal closure mechanism in repaired cleft palate infants is able to be predicted by velopharyngeal movement behavior before primary palatoplasty. Next, we must clarify a correlation between preoperative velopharyngeal movement and postoperative velopharyngeal function and speech outcome.

An Arabidopsis mutant hypersensitive to red and far-red light signals

A new mutant called psi2 (for phytochrome signaling) was isolated by screening for elevated activity of a chlorophyll a/b binding protein-luciferase (CAB2-LUC) transgene in Arabidopsis. This mutant exhibited hypersensitive induction of CAB1, CAB2, and the small subunit of ribulose-1,5-bisphosphate carboxylase (RBCS) promoters in the very low fluence range of red light and a hypersensitive response in hypocotyl growth in continuous red light of higher fluences. In addition, at high- but not low-light fluence rates, the mutant showed light-dependent superinduction of the pathogen-related protein gene PR-1a and developed spontaneous necrotic lesions in the absence of any pathogen. Expression of genes responding to various hormone and environmental stress pathways in the mutant was not significantly different from that of the wild type. Analysis of double mutants demonstrated that the effects of the psi2 mutation are dependent on both phytochromes phyA and phyB. The mutation is recessive and maps to the bottom of chromosome 5. Together, our results suggest that PSI2 specifically and negatively regulates both phyA and phyB phototransduction pathways. The induction of cell death by deregulated signaling pathways observed in psi2 is reminiscent of retinal degenerative diseases in animals and humans.

Protein synthesis and degradation change rapidly in response to food intake in muscle of food-deprived mice

The short-term changes in muscle protein synthesis and degradation after food intake are unclear. We investigated muscle protein metabolism after food intake in mice that were starved for 18 h and refed for 1 h. Protein synthesis activity was estimated by the polysome profiles, and protein degradation was estimated by plasma N tau-methylhistidine (MeHis) concentration, reflecting translational activity and myofibrillar protein degradation, respectively. MeHis is an index of myofibrillar protein degradation because it is not reused for protein synthesis and it is not metabolized. Stimulation of protein synthesis (polysome profile) and the reduction of protein degradation (plasma N tau-methylhistidine concentration) were observed immediately after feeding began. Protein synthesis returned to the prefeeding level by 6 h after refeeding, whereas protein degradation remained at a low level. The decreased plasma MeHis concentration after refeeding was not due to a decrease in MeHis release from muscle cells and an increase in the free MeHis pool size, because the changes in free MeHis concentration in muscle were similar to that of plasma. Plasma insulin concentration immediately rose with feeding and it returned to the prefeeding level by 3 h after refeeding. These results suggest that responses of postprandial protein metabolism are very rapid and that protein synthesis is regulated by insulin, whereas degradation is regulated by insulin and other dietary factors. Thus the ability of skeletal muscle to use nutrients more effectively by stimulating protein synthesis and reducing protein degradation may cause the accelerated rate of protein accretion in skeletal muscle during the short postprandial period.

Simple in-office closure of small intractable tympanic membrane perforations after myringoplasty

Perforations produced following myringoplasty are very difficult to close by ordinary cautery or patching even if they are small. Therefore we decided to close these intractable perforations with a skin graft from the cartilaginous ear canal. Our method is an in-office operation under local anesthesia. After the removal of epithelium from around the perforation a skin graft was placed by the over-lay method. A total of 11 patients were treated, of which 81.8% (9/11) demonstrated successful closure in the initial surgery and two re-perforations were successfully closed by a second and third operation, respectively. The technique used in this surgery is relatively easy and appropriate for in-office operations. The method's advantages include decreased invasiveness with minimal anesthesia and no requirement for ear canal packing or fixatives, and cosmetic benefit. This method also can be applied to perforations caused by chronic otitis media, traumatic perforations, and perforations after inserting tubes.

Proso millet protein elevates plasma level of high-density lipoprotein: a new food function of proso millet

We examined the effects of dietary proso-millet protein on plasma levels of high-density lipoprotein (HDL) cholesterol in different rats from animals reported in our previous studies. The results showed also, in this animal, that the ingestion of the millet protein elevates plasma levels of HDL-cholesterol like our earlier works. Taking into account the anti-atherogenic function of HDL, therefore, the millet protein would be useful as a new food ingredient which has the function that regulates cholesterol metabolism.

Thyroplasty type I with ceramic shim

To prevent side effects from a silicone shim in Isshiki thyroplasty type I, we used a ceramic shim in 10 patients with unilateral recurrent laryngeal nerve paralysis. No published reports have described the use of ceramic in this type of surgery. According to the degree of glottic insufficiency, ceramic shims of various heights were inserted into the fenestration made in the thyroid ala. All patients experienced subjective improvement of voice postoperatively. Laryngoscopies in most cases showed that glottic insufficiency improved postoperatively. In the postoperative examination, the maximum phonation time improved an average of 3.7 s, and the mean flow rate improved an average of 331 ml/s. We have analyzed the relationship of these improvements to the degree of glottic insufficiency and have compared our results with those of other investigators.

Plasma N tau-methylhistidine concentration is a sensitive index of myofibrillar protein degradation during starvation in rats

Urinary excretion of N tau-methylhistidine (MeHis) in rats was linearly elevated by starvation for 2 days. Plasma concentration of MeHis on day 1 and day 2 of starvation were increased 2.4- and 2.6-fold, respectively. The amount of released MeHis from the isolated muscles into medium during a 2-h incubation period was increased with starvation corresponded to the plasma MeHis concentration. The results of this study suggest that plasma MeHis is a sensitive index of myofibrillar protein degradation.

The elevation of plasma concentration of high-density lipoprotein cholesterol in mice fed with protein from proso millet

We examined the effects of dietary proso-millet protein on plasma concentration of high-density lipoprotein (HDL) cholesterol in mice. The results confirmed also, in this animal, the elevation of plasma concentration of HDL cholesterol without the involvement in raising the concentration of low-density lipoprotein cholesterol like those with rats reported in our previous paper. This would suggest a beneficial effect of millet protein on cholesterol metabolism.

The DIMINUTO gene of Arabidopsis is involved in regulating cell elongation

We have isolated a recessive mutation named diminuto (dim) from T-DNA transformed lines of Arabidopsis thaliana. Under normal growth conditions, the dim mutant has very short hypocotyls, petioles, stems, and roots because of the reduced size of cells along the longitudinal axes of these organs. In addition, dim results in the development of open cotyledons and primary leaves in dark-grown seedlings. The gene for DIM was cloned by T-DNA tagging. DIM encodes a novel protein of 561 amino acids that possesses bipartite sequence domains characteristic of nuclear localization signals. Molecular and physiological studies indicate that the loss-of-function mutant allele does not abolish the response of seedlings to light or phytohormones, although the inhibitory effect of light on hypocotyl elongation is greater in the mutant than in wild type. Moreover, the dim mutation affects the expression of a beta-tubulin gene, TUB1, which is thought to be important for plant cell growth. Our results suggest that the DIM gene product plays a critical role in the general process of plant cell elongation.

Symmetric and asymmetric fiber loop mirrors for observing guided-acoustic-wave Brillouin scattering in polarization-maintaining fibers

A new scheme of symmetric and asymmetric fiber loop mirrors is proposed to identify clearly the polarized guided-acoustic-wave Brillouin scattering spectra with multimode laser sources. The guided-acoustic-wave Brillouin scattering spectra in PANDA fibers in the low-frequency region are unambiguously confirmed with this scheme.

[Esophageal speech and TE shunt speech--a comparison using the same subjects]

The behaviors of esophageal speech and tracheoesophageal shunt (TE shunt) speech were compared using two laryngectomized subjects who were able to perform both phonation methods. Through X-ray fluorography and fiberscopic observation of the PE segment, it was confirmed that the location and the shape of the vibrating PE segment (pseudoglottis) were consistent during esophageal speech and TE shunt speech in each patient. It was suggested that the mechanism of formation of the pseudoglottis does not differ between the two phonation methods. The aerodynamics were examined using one of the two subjects. There was a positive relationship between subpseudoglottic pressure and vocal pitch and also between subpseudoglottic pressure and pseudoglottic resistance. The vocal pitch and pseudoglottic resistance were significantly higher in esophageal speech than TE shunt speech, when compared within the same subpseudoglottic pressure range. It was suggested that the tension and the effective mass of the pseudoglottis was modulated differently between the two phonation methods.