Synthesis of N-labeled peptidyl AMP

This paper deals with the synthesis of a new type of N-labeled peptidyl AMP, which would be used as a good substrate for analysis of the peptidyl transfer reaction on ribosome and for co-crystallization with ribosome. 4-(Dimethylamino)azobenzene-4'-sulfonyl (Dabsyl) was selected as the labeling group. (N-Dabsylglycyl)-L-leucyl AMP was synthesized from glycyl-L-leucine via a three-step procedure.

Combined submental flap with toe web for reconstruction of the lip with oral commissure

We present a new method employing a combined submental island flap and dorsalis pedis flap with the first toe web for reconstruction of a large lip defect including the oral commissure. The advantages of this method are: there is an excellent colour match; an anatomical structure similar to that of the oral commissure produces excellent results; there is superb function of the oral commissure; a donor-scar deformity can be avoided, since both flaps come from concealed areas; and good lining by the thin dorsal skin of the foot and submental skin results in a single-stage operation. The disadvantages are that complicated microvascular anastomoses may be required and there is a possibility of venous congestion of the submental flap in cases with a hypoplastic venous system. The use of the anterior jugular vein within the flap may be a key to overcoming this problem.

New multilobe "accordion" flaps for three-dimensional reconstruction of wide, full-thickness defects in the oral floor

When reconstructing a wide, full-thickness intraoral defect, the following principles are necessary for active food transport and improved swallowing and speech. First, the flap should touch the palate and obliterate the oral cavity. Second, jaw or flap excursion should not be hindered by tethering of the flap in the neck. And third, all surfaces of the tongue and oral floor, and the dead space of the floor should be reconstructed. To accomplish these goals, two new designs, similar to an accordion, using an anterolateral thigh flap and a deep inferior epigastric perforator flap have been developed. The outlines of multilobe flaps create an accordion-type structure of the tongue and oral floor complex. The advantages of the new designs using anterior thigh or deep inferior epigastric perforator flaps are follows: First, three-dimensional intraoral reconstitution allows maximal movement postoperatively of the reconstructed tongue. Second, the donor sites are so far from the tongue that simultaneous flap elevation is possible for tumor resectioning. Third, even in obese patients, totally or partially thin flaps are available. And fourth, in most patients the donor defects can be closed directly.

[A case of posttraumatic severe ventriculitis treated by intraventricular lavage]

A 44-year-old male was admitted in a state of semicoma, tonic convulsion and elevated body temperature nine days after sustaining head injury. He had severe nuchal rigidity. Computed tomography revealed dilation of ventricles and swelling of the brain parenchyma. We performed cerebrospinal fluid (CSF) drainage of both lateral ventricles immediately. The fluid drained from both ventricles was just like pus. We diagnosed the patient's condition as posttraumatic ventriculitis and meningitis. We performed intraventricular lavage (IL) which was our ventricular irrigating technique. IL was repeated until the 7th day postoperatively. The CSF data improved immediately. Continuous spinal drainage (CSD) also was used for CSF drainage from the 7th day postoperatively. The patient recovered without the need for CSF shunt. Some authors have reported the usefulness of continuous intraventricular irrigation (CIVI) for treatment of severe ventriculitis. However, their patients required CSF shunt surgeries. Such shunts are likely to become infected more frequently than routine shunting. Our IL was able to drain pus and inflammatory products in the ventricles before the formation of septations in the ventricles. We emphasize that IL in combination with CSD is able to bring about good results for patients with severe ventriculitis.

Supermicrosurgical lymphaticovenular anastomosis for the treatment of lymphedema in the upper extremities

Over the last eight years, the authors analyzed obstructive lymphedema of a unilateral upper extremity in a total of 27 females, comparing the use of supramicrosurgical lymphaticovenule anastomoses and/or conservative treatment. The most common cause of edema was mastectomy, with or without subsequent radiation therapy for breast cancer. As an objective assessment of the extent of edema, the circumferences of the affected and opposite normal forearms were measured at 10 cm below the olecranon of the arm. Twelve of these patients received continual bandaging. In these patients, the average excess circumference of the affected arm was 6.4 cm over that of the normal forearm; the average duration of edema before treatment was 3.5 years; the average period for conservative treatment was 10.6 months; and the average decrease in circumference was 0.8 cm (11.7 percent of the preoperative excess). Twelve patients underwent surgery and postoperative continual bandaging. In these patients, the average excess circumference was 8.9 cm; the average duration of edema before surgery was 8.2 years; the average follow-up after surgery was 2.2 years; and the average decrease in circumference was 4.1 cm (47.3 percent of the preoperative excess). These results indicated that supermicrolymphaticovenular anastomoses with postoperative bandaging have a valuable place in the treatment of obstructive lymphedema.

Synthesis of nucleotide antibiotics having N-acyl phosphoramidate linkages

This paper reports the synthesis of nucleotide antibiotics having N-acyl phosphoramidate linkages. The key reaction, the construction of the N-acyl phosphoramidate linkage was achieved by the reaction of nucleoside 5'-phosphoramidite derivatives with carboxamide derivatives in the presence of 5-(3,5-dinitrophenyl)-1H-tetrazole as a very effective activator. By use of this activator, Phosmidosine was synthesized by condensation of an appropriately protected 8-oxoadenosine 5'-O-phosphoramidite derivative with an N-protected prolinamide derivative. In the case of Agrocin 84, the two P-N bonds were constructed progressively. The N-acyl phosphoramidate linkage at the 5'-position of the ribose moiety was similarly synthesized. After phosphorylation of the amino group of the adenine moiety, a fully protected Agrocin 84 derivative, which would be converted to Agrocin 84, was successfully synthesized.

Deep inferior epigastric perforator dermal-fat or adiposal flap for correction of craniofacial contour deformities

Craniofacial contour deformities are difficult to reconstruct. This article summarizes the authors' use of deep inferior epigastric perforator dermal-fat or adiposal flaps in eight patients with such deformities. Of these patients, three had traumatic craniofacial or facial deformities, one had congenital craniofacial deformity, two had hemifacial atrophy (one because of radiation), one had hemifacial microsomia, and one had localized frontonasal lipodystrophy. Stable restoration of the facial contour was achieved in all eight patients. The advantages of this flap are numerous. It has minimal donor-site morbidity, because the rectus abdominis muscle is preserved as a whole, and it accommodates pregnancy in female patients. Simultaneous elevation of this flap during preparation of the recipient site makes it possible to complete surgery in a shorter time than with the scapular flap. Furthermore, a considerable amount of the superficial or deep fatty layer can be removed primarily, making a bulky flap into a thinner one. This flap also allows the use of a large transverse abdominal ellipse of skin, fat, and Scarpa's fascia with abdominoplasty closure. Conversely, it requires a technically difficult dissection of the muscle perforator and skin grafting of donor defects in patients with a large dermal-fat flap. Also, additional minor operations may be necessary to reduce fat volume around the perforator. Ultimately, the deep inferior epigastric perforator adiposal flap seems to be suitable for craniofacial contouring surgery. It is especially indicated for use in children and female patients who are expecting to have children.

New microsurgical breast reconstruction using free paraumbilical perforator adiposal flaps

Pedicled transverse rectus abdominis musculocutaneous (TRAM) flaps have generally been used for bilateral breast losses. The major disadvantages of this method are the total or partial loss of the rectus abdominis muscles and various resulting postoperative complications, such as abdominal bulging and lumbar pain. With the recent development of perforator flaps and supermicrosurgery with anastomosis of 0.5-mm caliber vessels, these serious complications can be overcome with a paraumbilical perforator adiposal flap, without sacrificing the rectus abdominis muscle. The breasts of a 57-year-old woman who had undergone a bilateral subcutaneous mastectomy, including silicone prostheses, were repaired simultaneously with this new method using free paraumbilical perforator adiposal flaps. This new method of breast augmentation with a vascularized adiposal flap and without any muscle component is minimally invasive; its advantages are the preservation of the rectus abdominis muscles and the short time elevation for the adiposal flap.

[Intravascular lymphomatosis diagnosed by bone marrow biopsy]

Intravascular lymphomatosis (IVL) is a rare malignancy characterized by neoplastic proliferation of lymphoid cells within the lumina of small vessels. We report a case of IVL in a 69-year-old woman, who presented with pancytopenia and elevation of the serum LDH level. There was no skin eruption or neurological abnormalities. Clusters of abnormal lymphoid cells were barely evident in a peripheral blood smear. Laboratory examinations revealed high levels of LDH (2,602 IU/l) and sIL-2R (5,640 U/ml). Bone marrow aspiration revealed a normal cellular marrow with mild hemophagocytosis, but no tumor cells were detected. After admission, respiratory failure due to multiple pulmonary embolisms progressed, and continuous infusion of heparin had no apparent effect. Bone marrow vessels filled with lymphoma cells were observed in a biopsy specimen, thus establishing a diagnosis of IVL. Chemotherapy with the CHOP regimen was immediately instituted. The respiratory failure was dramatically improved, resulting in disappearance of the abnormal lymphoid cells from the bone marrow. After eight courses of CHOP, low-dose etoposide therapy was administered, and no symptoms of relapse were noticed. The diagnosis of IVL is difficult because it does not form masses of tumor cells. Bone marrow biopsy may be helpful for early diagnosis of IVL if the disease is suspected and searched for.

Activation of mitogen-activated protein kinases after transient forebrain ischemia in gerbil hippocampus

We investigated the expression, activation, and distribution of c-Jun N-terminal kinases (JNKs), p38 mitogen-activated protein kinases (p38s) and extracellular signal-regulated kinases (ERKs) using Western blotting and immunohistochemistry in gerbil hippocampus after transient forebrain ischemia to clarify the role of these kinases in delayed neuronal death (DND) in the CA1 subfield. Immunoblot analysis demonstrated that activities of JNK, p38, and ERK in whole hippocampus were increased after 5 min of global ischemia. We used an immunohistochemical study to elucidate the temporal and spatial expression of these kinases after transient global ischemia. The immunohistochemical study showed that active JNK and p38 immunoreactivities were enhanced at 15 min of reperfusion and then gradually reduced and disappeared in the hippocampal CA1 region. On the other hand, in CA3 neurons, active JNK and p38 immunoreactivities were enhanced at 15 min of reperfusion and peaked at 6 hr of reperfusion and then gradually reduced but was continuously detected 72 hr after ischemia. Active ERK immunoreactivity was observed transiently in CA3 fibers and dentate gyrus. Pretreatment with SB203580, a p38 inhibitor, but not with PD98059, an ERK kinase 1/2 inhibitor, reduced ischemic cell death in the CA1 region after transient global ischemia by inhibiting the activity of p38. These findings indicate that the p38 pathway may play an important role in DND during brain ischemia in gerbil. Components of the pathway are important target molecules for clarifying the mechanism of neuronal death.

The evi-1 oncoprotein inhibits c-Jun N-terminal kinase and prevents stress-induced cell death

Evi-1 encodes a nuclear protein involved in leukemic transformation of hematopoietic cells. Evi-1 possesses two sets of zinc finger motifs separated into two domains, and its characteristics as a transcriptional regulator have been described. Here we show that Evi-1 acts as an inhibitor of c-Jun N-terminal kinase (JNK), a class of mitogen-activated protein kinases implicated in stress responses of cells. Evi-1 physically interacts with JNK, although it does not affect its phosphorylation. This interaction is required for inhibition of JNK. Evi-1 protects cells from stress-induced cell death with dependence on the ability to inhibit JNK. These results reveal a novel function of Evi-1, which provides evidence for inhibition of JNK by a nuclear oncogene product. Evi-1 blocks cell death by selectively inhibiting JNK, thereby contributing to oncogenic transformation of cells.

Changes in the levels of mRNAs for putative cell growth-related genes in the albedo and flavedo during citrus fruit development

 Changes in mRNA levels for the seven gene homologues to endoxyloglucan transferase-related protein, expansin, extensin, β-1,3 glucanase, glycine-rich protein, pectinacetylesterase and pectinesterase, which were obtained by random sequencing studies, were investigated in relation to rind development in citrus (Citrus unshiu Marc.) fruit. Expression patterns in the albedo and flavedo were classified into four types: Type-I, transcript levels low in early fruit development but increased at the ripening stage; Type-II, transcript levels high until mid-development and then decreased towards ripening; Type-III, detectable transcript limited to fruitlets at 26 days after flowering (DAF); Type-IV, ubiquitous during the development. Based on the expression patterns, we discuss the possible roles of these genes in rind development.

Fingertip reconstructions using partial-toe transfers

Fifty-six partial toes were transferred to reconstruct fingertip deficits. The transfers from the big toe mainly consisted of 3 trimmed big toetips, 3 vascularized nail grafts, 3 onychocutaneous flaps, 19 thin osteo-onychocutaneous flaps, and 2 hemipulp flaps. The transfers from the second toe mainly consisted of 8 trimmed second toetips, 5 reduced second toes, and 9 whole distal phalanges. The average values of postoperative sensory recovery of the osteo-onychocutaneous flaps including the vascularized nail grafts were 3.1 (Semmes-Weinstein test) and 6.3 mm (moving two-point discrimination) at 2.6 years after the transfer; those of the thin osteo-onychocutaneous flaps were 3.1 and 7.2 mm at 2.0 years after surgery; those of the trimmed big toe tip transfers were 3.61 and 6.5 mm at 1.8 years after surgery; and those of the trimmed second toetip transfers were 3.37 and 6.3 mm at 2.6 years after transfer. Those of the distal phalanx of the second toe were 3.41 and 7.9 mm at 1.2 years after surgery, and those of the reduced second toe were 3.2 and 6.7 mm at 10.6 months after surgery.

Molecular cloning and characterization of a novel gene encoding limonoid UDP-glucosyltransferase in Citrus

We isolated a cDNA clone encoding limonoid UDP-glucosyltransferase (limonoid GTase) from the albedo of Satsuma mandarin (Citrus unshiu Marc.) and investigated the contribution to limonoid glucoside accumulation in fruit. The isolated cDNA clone (CitLGT) was 1732 bp in length encoding 511 deduced amino acids with a predicted molecular mass of 57.5 kDa. The products of in vitro translation from an expression vector had the limonoid GTase activity. Southern blot analysis of genomic DNA indicated that CitLGT was present as a single copy gene in the Citrus genome. The amount of transcript corresponding to CitLGT mRNA changed the same way as the fluctuation of limonin glucoside content during fruit development of navel orange (Citrus sinensis Osb.). This indicates that the transcription of CitLGT regulates the conversion of limonoid aglycones to glucosides in citrus fruit.

A conserved docking motif in MAP kinases common to substrates, activators and regulators

Mitogen-activated protein kinases (MAPKs) are specifically phosphorylated and activated by the MAPK kinases, phosphorylate various targets such as MAPK-activated protein kinases and transcription factors, and are inactivated by specific phosphatases. Recently, docking interactions via the non-catalytic regions of MAPKs have been suggested to be important in regulating these reactions. Here we identify docking sites in MAPKs and in MAPK-interacting enzymes. A docking domain in extracellular-signal-regulated kinase (ERK), a MAPK, serves as a common site for binding to the MAPK kinase MEK1, the MAPK-activated protein kinase MNK1 and the MAPK phosphatase MKP3. Two aspartic acids in this domain are essential for docking, one of which is mutated in the sevenmaker mutant of Drosophila ERK/Rolled. A corresponding domain in the MAPKs p38 and JNK/SAPK also serves as a common docking site for their MEKs, MAPK-activated protein kinases and MKPs. These docking interactions increase the efficiency of the enzymatic reactions. These findings reveal a hitherto unidentified docking motif in MAPKs that is used in common for recognition of their activators, substrates and regulators.

Molecular cloning of a homologue of dad-1 gene in citrus: distinctive expression during fruit development

A cDNA homologue to the human defender against apoptotic death gene (dad-1), which is involved in programmed cell death, was isolated from satsuma mandarin (Citrus unshiu Marc.) fruit. It (Citdad-1-1) was 345 bp long, with a deduced protein sequence of 115 amino acids. Southern hybridization suggests that dad-1-related sequences are present as a small gene family in the citrus genome. Expression of Citdad-1-1 was progressively down-regulated in leaves as they matured, but not in juice sac/segment epidermis (edible part) towards fruit ripening. The role of dad-1 during citrus development is also discussed.

Distinct domains of mouse dishevelled are responsible for the c-Jun N-terminal kinase/stress-activated protein kinase activation and the axis formation in vertebrates

Recent studies have shown that Drosophila Dishevelled (Dsh), an essential component of the wingless signal transduction, is also involved in planar polarity signaling through the c-Jun N-terminal kinase (JNK)/stress-activated protein kinase (SAPK) pathway in Drosophila. Here, we show that expression of a mouse homolog of Dsh (mDvl-1) in NIH3T3 cells activates JNK/SAPK, and its activator MKK7. A C-terminal half of mDvl-1 which contains the DEP domain was sufficient for the activation of JNK/SAPK, whereas an N-terminal half of mDvl-1 as well as the DEP domain is required for stimulation of the TCF/LEF-1-dependent transcriptional activation, a beta-catenin-dependent process. A single amino acid substitution (Met for Lys) within the DEP domain (mDvl-1 (KM)) abolished the JNK/SAPK-activating activity of mDvl-1, but did not affect the activity to activate the LEF-1-dependent transcription. Ectopic expression of mDvl-1 (KM) or an N-terminal half of mDvl-1, but not the C-terminal, was able to induce secondary axis in Xenopus embryos. Because the secondary axis formation is dependent on the Wnt/beta-catenin signaling pathway, these results suggest that distinct domains of mDvl-1 are responsible for the two downstream signaling pathways, the beta-catenin pathway and the JNK/SAPK pathway in vertebrates.

Activation of the protein kinase ERK5/BMK1 by receptor tyrosine kinases. Identification and characterization of a signaling pathway to the nucleus

ERK5 (also known as BMK1), a member of the mitogen-activated protein kinase (MAPK) superfamily, was known to be activated strongly by oxidant and osmotic stresses. Here we have found that ERK5 is strongly activated by epidermal growth factor and nerve growth factor, whose receptors are tyrosine kinases. The activation of ERK5 was inhibited by expression of dominant-negative Ras and induced by expression of active Ras in PC12 cells, indicating a requirement for Ras in ERK5 activation. The epidermal growth factor-induced activation of ERK5 was found to be inhibited by PD98059 and U0126 inhibitors, which were previously thought to act specifically on classical MAPK kinase (also known as MEK1) and readily reversed by CL100 and MKP-3 dual-specificity phosphatases for which classical MAPKs were previously shown to serve as preferred substrates. The reporter assays demonstrated that the serum-induced enhancement of transcription from serum response element was significantly inhibited by expression of a dominant-negative form of MEK5, which was a direct and specific activator for ERK5 and that transcription from serum response element mediated by the Ets-domain transcription factor Sap1a, but not by Elk1, was stimulated by coexpression of ERK5 and active MEK5. In addition, Sap1a was shown to be phosphorylated by ERK5 in vitro and by the activation of the ERK5 pathway in cells. Moreover, the serum-induced c-Fos expression was markedly inhibited by expression of dominant-negative MEK5. These results reveal a novel signaling pathway to the nucleus mediated by ERK5 that functions downstream of receptor tyrosine kinases to induce immediate early genes, in parallel with the classical MAPK cascade.

[Supramicrosurgical lymphaticovenular anastomosis for the treatment of lymphedema in the extremities]

During the past eight years, we treated obstructive lymphedema of a unilateral upper extremity in 27 females and of a unilateral or bilateral lower extremity in 35 males and females with supramicrosurgical lymphaticovenular anastomoses and/or conservative treatment. The most common cause of upper limb edema was mastectomy with or without subsequent radiation therapy for breast cancer, and that of lower limb edema was hysterectomy with radiation. As an objective assessment of edema, the circumferences of the affected and opposite normal forearms or lower legs were measured 10 cm below the olecranon of the arm or the lower border of the patella. In patients who received conservative treatment (12 arms and 12 legs), the average excess circumferential length of the affected arm and leg was 6.4 and 7.1 cm over that of normal extremities, average duration of edema before treatment was 3.5 and 5.2 years, average period for conservative treatment was 10.6 months and 1.5 years, and average decreased circumferential length was 0.8 and 0.6 cm, respectively. The rate of circumferential decrease over 4 cm was none in arm and 16.7% in leg edema. In patients who underwent surgery (12 arms and 16 legs), the average excess circumferencial length was 8.9 and 9.8 cm, average duration of edema before surgery was 8.2 and 8.9 years, average follow-up after surgery was 2.2 and 3.3 years, and average decrease in excess circumference was 4.1 and 2.7 cm, respectively. The rate of circumferential decrease over 4 cm was 58.3% in arms and 50% in legs. These results indicate that supramicrolymphaticovenular anastomoses have a valuable place in the treatment of obstructive lymphedema.

Dynamic reconstruction of the abdominal wall using a reinnervated free rectus femoris muscle transfer

Dynamic reconstruction of the abdominal wall using a free reinnervated rectus femoris muscle and an island tensor fascia lata transfer was performed for a large herniation with loss of the bilateral rectus abdominis muscles of the abdominal wall. The tensor fascia lata transfer was used to close an inner side of the abdominal defect, and the rectus femoris muscle replaced the rectus abdominis muscle deficit. The motor nerve of the rectus femoris muscle was sutured to the motor branch of the intercostal nerve. Postoperatively, the transferred rectus femoris muscle was reinnervated via electromyography, and there was no abdominal protrusion and no hernia recurrence.

Molecular cloning and characterization of a novel dual specificity phosphatase, MKP-5

A group of dual specificity protein phosphatases negatively regulates members of the mitogen-activated protein kinase (MAPK) superfamily, which consists of three major subfamilies, MAPK/extracellular signal-regulated kinase (ERK), stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), and p38. Nine members of this group of dual specificity phosphatases have previously been cloned. They show distinct substrate specificities for MAPKs, different tissue distribution and subcellular localization, and different modes of inducibility of their expression by extracellular stimuli. Here we have cloned and characterized a novel dual specificity phosphatase, which we have designated MKP-5. MKP-5 is a protein of 482 amino acids with a calculated molecular mass of 52.6 kDa and consists of 150 N-terminal amino acids of unknown function, two Cdc25 homology 2 regions in the middle, and a C-terminal catalytic domain. MKP-5 binds to p38 and SAPK/JNK, but not to MAPK/ERK, and inactivates p38 and SAPK/JNK, but not MAPK/ERK. p38 is a preferred substrate. The subcellular localization of MKP-5 is unique; it is present evenly in both the cytoplasm and the nucleus. MKP-5 mRNA is widely expressed in various tissues and organs, and its expression in cultured cells is elevated by stress stimuli. These results suggest that MKP-5 is a novel type of dual specificity phosphatase specific for p38 and SAPK/JNK.

Structure and function of human prepro-orexin gene

Orexin-A and -B are recently identified potent orexigenic peptides that are derived from the same precursor peptide and are highly specifically localized in neurons located in the lateral hypothalamic area, a region classically implicated in feeding behavior. We cloned the whole length of the human prepro-orexin gene and corresponding cDNA. The human prepro-orexin mRNA was predicted to encode a 131-residue precursor peptide (prepro-orexin). The human prepro-orexin gene consists of two exons and one intron distributed over 1432 base pairs. The 143-base pair first exon includes the 5'-untranslated region and a small part of the coding region that encodes the first seven residues of the secretory signal sequence. The second exon contains the remaining portion of the open reading frame and 3'-untranslated region. The 3.2 kilobase pairs of the 5'-upstream region from a cloned human prepro-orexin gene promoter is sufficient to direct the expression of the Escherichia coli beta-galactosidase (lacZ) gene in transgenic mice to neurons in the lateral hypothalamic area and adjacent regions. The lacZ-positive neurons were positively stained with anti-orexin antibody but not with anti-melanin-concentrating hormone antibody. These findings suggest that this genomic fragment contains all the necessary elements for appropriate expression of the gene and will be useful for the targeted expression of the exogenous gene in orexin-containing neurons. These mice might also be useful for examining the molecular mechanisms by which orexin gene expression is regulated.

Ear helix flap for reconstruction of total loss of the upper eyelid

We present a patient with a recurrent carcinoma of the right upper eyelid who underwent resection of the subtotal upper eyelid resulting in a full-thickness defect. The eyelid was reconstructed with advanced conjunctival lining and an ascending helix chondrocutaneous flap from the right auricle. This flap was nourished with a reverse flow of the frontal branch of the superficial temporal vessels. A superficial temporal vein of the flap was anastomosed to the zygomaticofacial branch of the superficial temporal vein at the lateral canthal region to ensure adequate drainage. The flap survived without any congestion. An ascending helix flap is the best candidate for total loss of the upper eyelid.

[Usefulness of percutaneous sclerosing treatment for low-flow vascular lesions]

Peripheral vascular lesions may occur as a result of various clinical problems, cosmetic or dysfunctional causes, or bleeding. In severe cases, coagulopathy and congestive heart failure may occur. Although the efficacy of transarterial embolization (TAE) for arterial vascular lesions is well known, TAE has no effect on low-flow vascular lesions (venous malformations, venous angiomas, and venous components of arteriovenous malformation). Therefore, in such cases, a percutaneous approach is the best method, and we consider sclerotherapy to be the most useful conservative treatment. The primary objective of this study was to confirm the efficacy of percutaneous sclerosing treatment for peripheral low-flow vascular lesions. Lesions were classified on the basis of state of blood flow and morphologic features, and infiltration was classified on the basis of angiographic features and magnetic resonance imaging (MRI) findings. In sclerosing treatment, we used 5% solutions of polidocanol, absolute ethanol, and N-butyl-2-cyanoacrylate (NBCA) as sclerosing agents. Each type of lesion, static or slow-flow, cystic, or localized, showed remarkable improvement after sclerosing treatment with only polidocanol. However, for moderate-to-fast-flow lesions, another sclerosing agent (absolute ethanol/NBCA) was needed. With diffuse infiltrative lesions, surgical repair might be needed, but we recognize the usefulness of sclerosing treatment for functional or cosmetic improvement in these cases.

One type of chalcone synthase gene expressed during embryogenesis regulates the flavonoid accumulation in citrus cell cultures

To elucidate the relationship between the expression of chalcone synthase (CHS) genes and the production of flavonoid in citrus cell cultures, two cDNA clones encoding CHS were isolated (CitCHS1 and CitCHS2) from the citrus. The accumulation of CitCHS2 mRNA was notably induced by embryogenesis but CitCHS1 mRNA was not. There was no detectable accumulation of flavonoid in the undifferentiated calli, but flavonoid accumulated after the morphological changes to embryoids. These results indicate that two CHS genes differentially expressed during citrus somatic embryogenesis and CitCHS2 may regulate the accumulation of flavonoid in citrus cell cultures.

Denervation of Pacinian corpuscles: electron microscopic observations in the rat following nerve transection

Nerve transection using rat sciatic nerves was employed to observe morphologic changes in the periodic denervation of Pacinian corpuscles. During periods of from 1 to 20 weeks after surgery, a total of 15 corpuscles were obtained under the operating microscope and processed for morphologic analysis using light and electron microscopes. Based on the morphologic findings, normal corpuscles were composed of an axon terminal and inner and outer core cells. Following nerve transection, the axon terminal immediately disappeared at 1 week, but the original inner and outer core cells were preserved, with macrophage migration occurring in the outer core. After 8 weeks, the circular regularity of the inner and outer core lamellae was occasionally broken. The lamellae had wavy courses and there were many empty spaces in the inner core. Even at 20 weeks after denervation, there was interruption in the continuity of the outer core cells; the membranous structure of the outer core and the lamellar structure of the inner core were well-preserved; the outer and inner core cells were still present. Simultaneously, a small number of collagen fibrils were observed between the inner and outer core cells from the earliest postoperative stage. These fibrils increased in number in later stages. The results suggest that, immediately after destruction of axon terminals, macrophages migrate into the interlamellar spaces where they engulf the debris of the degenerated axon terminals. The degeneration of the corpuscles seems to be similar to that of denervated nerve axons; therefore, the inner core cells, which are continuous with the Schwann cells, maintain their original condition for at least 20 weeks after corpuscle denervation. The outer core cells, which are continuous with the perineurial nerve cells, are assumed to be the main cells producing the collagen fibrils in the denervated Pacinian corpuscles.

Neurons containing orexin in the lateral hypothalamic area of the adult rat brain are activated by insulin-induced acute hypoglycemia

Orexin-A and -B (also known as hypocretin-1 and -2) are neuropeptides which stimulate food intake when administered intracerebroventricularly. Orexins are specifically localized in neurons within and around the lateral hypothalamic area (LHA). Previous electrophysiological studies have demonstrated that some neurons in the LHA are activated by hypoglycemia, and are therefore termed 'glucose-sensitive neurons'. In the present study, we examined whether orexin-containing neurons are activated in the hypoglycemic states, using Fos-like immunoreactivity (FLI) as a marker of neuronal activation. We observed that FLI was induced in the LHA by acute insulin treatment. Double staining with anti-Fos and anti-orexin antibodies revealed that up to 33% of the orexin-containing neurons in the LHA also expressed FLI under the hypoglycemic condition. These results suggest that some populations of neurons which contain orexins are activated under hypoglycemic conditions.

Flow-through thin latissimus dorsi perforator flap for repair of soft-tissue defects in the legs

Flow-through thin latissimus dorsi perforator flaps were used in six cases with complicated defects of the legs. This flap has a small amount of latissimus dorsi muscle with a considerable amount of fatty tissue removed to make a thin flap. In addition, the flap has several branches of the subscapular vessel, which are interposed to the recipient vessels of the legs. The advantages of this thin flap are: (1) flow-through vascular reconstruction can preserve the main vessels of the damaged legs; (2) the double arterial inflows and venous drainage systems of the flap ensure safe vascularization of the flap; (3) a flow-through venous drainage system from the distal extremities can also be established to prevent congestion of the affected legs; (4) this flap is versatile (it can be either thin or large); and (5) even in emergent ischemic legs, simultaneous elevation of the flap is possible with preparation of the legs. This flow-through flap is indicated for: (1) cases with a large skin defect and obstruction of the main vessels in the leg; (2) cases with a possibility of tumor recurrence in the legs; and (3) young women or girls with a large defect in the legs, rather than the rectus abdominis musculocutaneous flap.

Free vascularized appendix transfer for reconstruction of penile urethras with severe fibrosis

Despite the development of newer techniques with a free radial forearm tube flaps for phallus reconstruction, severe urethral strictures are still seen in such cases after irradiation or repeated infection because of the paucity of healthy, well-vascularized tissue. For urethral reconstruction in cases with poorly vascularized tissue as well as for total penile creation, a new technique involving a free vascularized appendix transfer combined with a radial forearm osteocutaneous flap was successfully used in two cases. The appendix provides a normal tube structure composed of a muscular tubular layer lined with mucosal epithelium. It has no hair and has rich vascularization. This results in little stricture at the junction with the original urethra, no occurrence of urethral stones, and possible postoperative enlargement of the diameter with changes in catheters. This method will allow a patient with severe fibrosis around the urethra to undergo one-stage phallus reconstruction with minimal complications.

Isolation of Biopterin-alpha-glucoside from Spirulina (Arthrospira) platensis and Its Physiologic Function

: A fluorescent substance was isolated from the cyanobacterium with a yield of 4.5 mg per 10 g of dried Spirulina (Arthrospira) platensis cells by gentle extraction and ethanol fractionation followed by column chromatography. The fluorescent substance, which has absorption maxima at 256 nm and 362 nm (pH 8.4), was identified as biopterin-alpha-glucoside by spectrophotometry and nuclear magnetic resonance spectroscopy. Biopterin-alpha-glucoside prevented decolorization of the photosynthetic pigments, chlorophyll a, phycocyanin, and carotenoids in photosynthetic vesicles of Spirulina platensis cells, by ultraviolet irradiation.

Functional relationship between age-related immunodeficiency and learning deterioration

Disordered immune responses are supposed to alter the function of the central nervous system through the neuroendocrine immunomodulation network. In this paper, we studied the influence of the immune function on learning performances from the angle of pharmacology using aged garlic extract (AGE), an immunomodulator. Splenocyte proliferation, induced by concanavalin A or lipopolysaccharide, and the antibody production response were declined in senescence accelerated mouse-prone 8 (SAMP8) aged 12 months compared with age-matched SAMR1 (SAM-resistant 1). Chronic oral administration of AGE-containing food (2%, w/w) significantly enhanced the immune responses of both SAMP8 and SAMR1. Male ddY mice were thymectomized 4 weeks after birth and fed AGE-containing food after the operation until the experiments were finished. Learning performances, brain monoamine content and choline acetyltransferase (ChAT) activity, as well as the immune response were evaluated 10 months after the operation. Thymectomy resulted in not only immunodeficiency, but also deteriorated learning ability. AGE treatment prevented the reduction of the antibody production response induced by thymectomy and improved the thymectomy-induced deterioration of learning behaviours in passive avoidance performance and in a spatial memory task. The contents of hypothalamic noradrenaline, 3,4-dihydroxyphenylacetic acid and homovanillic acid, and the hypothalamic ChAT activity were increased in thymectomized mice compared to those of sham-operated control, while AGE treatment restored them to the control levels. These results suggest that the improvement of immune function is closely related to the amelioration of age-associated deterioration of learning and memory.

Characterization of a cDNA homologous to carotenoid-associated protein in citrus fruits

A cDNA (CitPAP) homologous to a gene encoding for Cucumis sativus carotenoid-associated protein (CHRC) has been isolated from satsuma mandarin (Citrus unshiu Marc.). Unlike ChrC whose expression was limited only in mature fruits (containing chromoplasts), CitPAP transcripts were detected in all the tissues examined including fruits, flowers and leaves. In this respect, CitPAP was rather close to a gene encoding for pepper plastid-lipid-associated protein (PAP), which exhibits ubiquitous expression in bell pepper organs containing chloroplasts or chromoplasts. CitPAP, however, differed from PAP in the magnitude and pattern of RNA accumulation. These results might indicate a novel function of CitPAP.

Free combined anterolateral thigh flap and vascularized fibula for wide, through-and-through oromandibular defects

Through-and-through oromandibular defects require the greatest amount of soft-tissue volume among the transfers for head and neck defects. A new method, a large anterolateral thigh flap combined with a vascularized fibula graft in a chimera fashion, has been used for two patients with wide through-and-through oromandibular defects. Among the candidates for such a large skin flap, the anterolateral thigh flap seems to be the best, for the following reasons. (1) Its pedicle, the lateral circumflex femoral system, has several major branches of equal size of anastomosis of the peroneal vessels. (2) As the majority of such patients with multiple previous surgery have lost recipient vessels near the mandible, the longest vascular pedicle is required. (3) There is no need for positional changes, and simultaneous flap elevation with the tumor resectioning is possible. (4) Use of the fibula allows for reconstruction of the entire mandible, if necessary. (5) Some of the shortcomings of individual donor sites for massive composite osteocutaneous flaps are minimized, because each component consists of two donor sites. (6) Operating time for this flap elevation is minimized, compared to that for massive composite osteocutaneous flaps, because the individual components can be obtained simultaneously by two teams.

Flow-through vascularized toe-joint transfer for reconstruction of segmental loss of an amputated finger

A segmental finger defect was reconstructed in a 46-year-old woman with a free flow-through vascularized toe-joint, including the proximal interphalangeal joint, the plantar digital nerve, and tendons of the second toe. The advantages of this composite flap are: (1) The segmental loss of the finger can be easily reconstructed to achieve a normal anatomic structure. (2) Excellent cosmesis is achieved, compared with conventional flaps such as the groin flap. (3) The distal segment of the donor toe can be preserved. (4) The transected digital arteries of the amputated finger can be simultaneously reconstructed with a flow-through arterial interposition. (5) The digital nerve can be repaired with a vascularized plantar digital nerve graft.

Differential roles of ERK and p38 MAP kinase pathways in positive and negative selection of T lymphocytes

Clonal selection of T lymphocytes is essential for establishing self/non-self discrimination of immune recognition. It is known that cell surface signals such as avidity and valency of TCR-ligand interactions influence the fate of individual thymocytes, founding a primary repertoire of T cells. However, intracellular signals that govern positive and negative selection in the thymus have been unclear. The present study using the retroviral gene transfer technique shows that MKK1 activation in developing T cells is sufficient for providing positive selection signals. We also show that the MKK6-p38 signaling pathway is critically involved in inducing negative selection of thymocytes. These results suggest that intracellular signals through different MAP kinase cascades selectively guide positive and negative selection of T lymphocytes.

Paraumbilical perforator flap without deep inferior epigastric vessels

With the introduction of supramicrosurgery, a new paraumbilical perforator flap without a deep inferior epigastric vessel and with very small perforator anastomoses was used for nine patients. The abdominal defects of two patients, the lower leg or foot defects of five patients, and the scalp defects of two patients were repaired with an island perforator flap. The advantages of the paraumbilical perforator flap are as follows: (1) there is a very short operating time for flap elevation; (2) there is no invasion or sacrifice of any rectus abdominis muscle; (3) for middle-aged, obese patients, the donor site may be the best from the cosmetic point of view; (4) many small recipient vessels to anastomose the perforator exist throughout the body; (5) a thin skin flap with adequate thickness can be created easily with simultaneous removal of fatty tissue; (6) secondary defatting around the perforator can be done by minor surgery under local anesthesia; and (7) a vascularized adiposal flap with adequate thickness can be created easily. This flap seems to be indicated for female patients with defects in the abdominal wall and the lower leg. The island flap can easily resurface abdominal skin defects, such as intestinal fistula or radiation ulcers. The free flap is suitable for covering defects in the lower leg, foot, and scalp temporarily before administration of a tissue expander.

[Efficacy and safety of two methods of administration of granisetron injection for nausea and vomiting induced by chemotherapy for tumors in hematopoietic organs--a randomized crossover comparison between intravenous drip infusion and intravenous bolus injection]

We investigated the efficacy and safety of two methods of granisetron injection to treat nausea and vomiting induced by chemotherapy for tumors in hematopoietic organs. The methods of administration were intravenous drip infusion over 30 minutes, which is the conventional method, and intravenous bolus injection. In this study, 89.5% of patients in both groups (17/19 for each) were free from vomiting. No serious adverse events were observed in either administration group. Abnormal laboratory test values suspected to be related to granisetron were observed in 3 cases in the bolus injection group and in 2 cases in the drip infusion group. but did not pose any clinical problem. These results demonstrated the safety of both methods of administration. In conclusion, it is considered that granisetron intravenous bolus injection can be considered as the method of choice for the prevention of nausea and vomiting induced by chemotherapy for tumors in hematopoietic organs.

Nuclear export of cyclin B1 and its possible role in the DNA damage-induced G2 checkpoint

M-phase-promoting factor (MPF), a complex of cdc2 and a B-type cyclin, is a key regulator of the G2/M cell cycle transition. Cyclin B1 accumulates in the cytoplasm through S and G2 phases and translocates to the nucleus during prophase. We show here that cytoplasmic localization of cyclin B1 during interphase is directed by its nuclear export signal (NES)-dependent transport mechanism. Treatment of HeLa cells with leptomycin B (LMB), a specific inhibitor of the NES-dependent transport, resulted in nuclear accumulation of cyclin B1 in G2 phase. Disruption of an NES which has been identified in cyclin B1 here abolished the nuclear export of this protein, and consequently the NES-disrupted cyclin B1 when expressed in cells accumulated in the nucleus. Moreover, we show that expression of the NES-disrupted cyclin B1 or LMB treatment of the cells is able to override the DNA damage-induced G2 checkpoint when combined with caffeine treatment. These results suggest a role of nuclear exclusion of cyclin B1 in the DNA damage-induced G2 checkpoint.

T lymphocyte activation signals for interleukin-2 production involve activation of MKK6-p38 and MKK7-SAPK/JNK signaling pathways sensitive to cyclosporin A

p38/CSBP, a subgroup member of mitogen-activated protein kinase (MAPK) superfamily molecules, is known to be activated by proinflammatory cytokines and environmental stresses. We report here that p38 is specifically activated by signals that lead to interleukin-2 (IL-2) production in T lymphocytes. A p38 activator MKK6 was also markedly activated by the same stimulation. Pretreatment of cells with SB203580, a specific inhibitor of p38, as well as expression of a dominant-negative mutant of MKK6, suppressed the transcriptional activation of the IL-2 promoter. We also demonstrated that MKK7, a recently described MAPK kinase family member, plays a major role in the activation of stress-activated protein kinase (SAPK)/c-Jun NH2-terminal kinase (JNK) in T lymphocytes. Moreover, a dominant-negative mutant of MKK7 abrogated the transcriptional activation of the distal nuclear factor of activated T cells response element in the IL-2 promoter. Cyclosporin A, a potent immunosuppressant, inhibited activation of both p38 and SAPK/JNK pathways but not the MAPK/extracellular signal-regulated kinase (ERK) pathway. Our results indicate that both MKK6 to p38 and MKK7 to SAPK/JNK signaling pathways are activated in a cyclosporin A-sensitive manner and contribute to IL-2 gene expression in T lymphocytes.

Characterization of gene repertoires at mature stage of citrus fruits through random sequencing and analysis of redundant metallothionein-like genes expressed during fruit development

We carried out a random sequencing of cDNA library derived from mature citrus fruit (Citrus unshiu Marc.) for identifying the gene repertoires expressed at the mature stage. Among 297 clones analyzed, 195 cDNA clones (65.7%) were putatively identified to previously characterized genes with optimized (OPT) scores of >/=200 through a homology search to DNA database, whereas 102 clones (34.3%) resulted in low OPT scores (<200) and did not show any significant sequence identity with previously published genes. Among them, clones homologous to metallothionein (MT)-like genes appeared 62 times, being mostly redundant, and accounting for about 20.9% of the total 297 clones. To gain a better understanding of the MT-like genes, two types of cDNA clones were isolated. One clone (CitMT36) resembled the type 2 MT gene containing Cys-X-Cys motifs in both N- and C-terminal, but the consensus sequence in the N-terminal domain, Cys-Cys and Cys-X-X-Cys was modified in CitMT36 to X-Cys and Cys-X-X-X, respectively. We suggest that these form a 'novel type 2' group of MT-like clones. The other clone (CitMT45) showed homology to type 3 MT-like genes, which have been found in mostly fruit tissues so far. By Southern blot analysis, both clones showed one or two bands, suggesting that both CitMT36 and CitMT45 are present in single or a few copies in the citrus genome. Transcripts of CitMT36 were evenly detected in all tissues examined, whereas those of CitMT45 were detected primarily in fruit during the developmental phase. Neither of the MT-like genes was induced in leaves by Zn and Cu. Collectively, MT-like genes from citrus would be regulated differentially depending on the fruit developmental stage and organs, indicating a change in their expression under the different physiological and molecular environment of fruit cells.

Activation of the protein kinase p38 in the spindle assembly checkpoint and mitotic arrest

The mitogen-activated protein kinase (MAPK) superfamily comprises classical MAPK (also called ERK), c-Jun amino-terminal or stress-activated protein kinase (JNK or SAPK), and p38. Although MAPK is essential for meiotic processes in Xenopus oocytes and the spindle assembly checkpoint in Xenopus egg extracts, the role of members of the MAPK superfamily in M phase or the spindle assembly checkpoint during somatic cell cycles has not been elucidated. The kinase p38, but not MAPK or JNK, was activated in mammalian cultured cells when the cells were arrested in M phase by disruption of the spindle with nocodazole. Addition of activated recombinant p38 to Xenopus cell-free extracts caused arrest of the extracts in M phase, and injection of activated p38 into cleaving embryos induced mitotic arrest. Treatment of NIH 3T3 cells with a specific inhibitor of p38 suppressed activation of the checkpoint by nocodazole. Thus, p38 functions as a component of the spindle assembly checkpoint in somatic cell cycles.

Differential activation of two JNK activators, MKK7 and SEK1, by MKN28-derived nonreceptor serine/threonine kinase/mixed lineage kinase 2

MKN28-derived nonreceptor type of serine/threonine kinase/mixed lineage kinase 2 (MST/MLK2) directly phosphorylates and activates SEK1/MKK4/JNKK1/SKK1 in vitro, thereby acting as a mitogen-activated protein (MAP) kinase kinase kinase in the JNK/SAPK pathway (Hirai, S. -i., Katoh, M., Terada, M., Kyriakis, J. M., Zon, L. I., Rana, A., Avruch, J., and Ohno, S. (1997) J. Biol. Chem. 272, 15167-15173). The in vitro reconstitution system for the kinase cascade allowed us now to identify JNK/SAPK activators involved in the MST/MLK2-dependent activation of JNK/SAPK in vivo. We show that at least two distinct MST/MLK2-dependent JNK/SAPK activators are present in the fractionated COS-1 cell lysate, and that they appear to be SEK1/MKK4/JNKK1/SKK1 and MKK7/JNKK2/SKK4 by Western blot analysis. Notably, a majority of the MST/MLK2-dependent JNK/SAPK-activating activity is found in MKK7-containing fractions, whereas the MEKK1-dependent activity is comparably distributed in SEK1- and MKK7-containing fractions. Moreover, MST/MLK2 activates recombinant MKK7 more effectively than recombinant SEK1, whereas MEKK1 activates both to a similar extent. In addition, the deletion analysis on MST/MLK2 showed that the kinase domain is responsible for the determination of substrate specificity. These results provide a molecular aspect to the differential regulation of the two JNK activators by a variety of cellular stimuli.

A novel SAPK/JNK kinase, MKK7, stimulated by TNFalpha and cellular stresses

Stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), a member of the MAP kinase (MAPK) superfamily, is thought to play a key role in a variety of cellular responses. To date, SEK1/MKK4, one of the MAP kinase kinase (MAPKK) family of molecules, is the only SAPK/JNK kinase that has been cloned. Here we have cloned, identified and characterized a novel member of the mammalian MAPKKs, designated MKK7. MKK7 is most similar to the mediator of morphogenesis, hemipterous (hep), in Drosophila. Immunochemical studies have identified MKK7 as one of the major SAPK/JNK-activating kinases in osmotically shocked cells. While SEK1/MKK4 can activate both the SAPK/JNK and p38 subgroups of the MAPK superfamily, MKK7 is specific for the SAPK/JNK subgroup. MKK7 is activated strongly by tumour necrosis factor alpha (TNFalpha) as well as by environmental stresses, whereas SEK1/MKK4 is not activated by TNFalpha. Column fractionation studies have shown that MKK7 is a major activator for SAPK/JNK in the TNFalpha-stimulated pathway. Moreover, we have found that overexpression of MKK7 enhances transcription from an AP-1-dependent reporter construct. Thus, MKK7 is an evolutionarily conserved MAPKK isoform which is specific for SAPK/JNK, is involved in AP-1-dependent transcription and may be a crucial mediator of TNFalpha signalling.

Neurotrophic activity of organosulfur compounds having a thioallyl group on cultured rat hippocampal neurons

Several organosulfur compounds found in garlic extract promoted the survival of rat hippocampal neurons in vitro. From the analysis of structure-activity relationship, thioallyl group in these compounds is essential for the manifestation of neurotrophic activity. S-Allyl-L-cysteine (SAC), one of the organosulfur compounds having thioallyl group in garlic extract, also promoted the axonal branching of cultured neurons. These results suggest that thioallyl compounds make a unique group of neurotrophic factors.

Fas induces cytoplasmic apoptotic responses and activation of the MKK7-JNK/SAPK and MKK6-p38 pathways independent of CPP32-like proteases

IL-1beta converting enzyme (ICE) family cysteine proteases are subdivided into three groups; ICE-, CPP32-, and Ich-1-like proteases. In Fas-induced apoptosis, activation of ICE-like proteases is followed by activation of CPP32-like proteases which is thought to be essential for execution of the cell death. It was recently reported that two subfamily members of the mitogen-activated protein kinase superfamily, JNK/SAPK and p38, are activated during Fas-induced apoptosis. Here, we have shown that MKK7, but not SEK1/ MKK4, is activated by Fas as an activator for JNK/ SAPK and that MKK6 is a major activator for p38 in Fas signaling. Then, to dissect various cellular responses induced by Fas, we used several peptide inhibitors for ICE family proteases in Fas-treated Jurkat cells and KB cells. While Z-VAD-FK which inhibited almost all the Fas-induced cellular responses blocked the activation of JNK/SAPK and p38, Ac-DEVD-CHO and Z-DEVD-FK, specific inhibitors for CPP32-like proteases, which inhibited the Fas-induced chromatin condensation and DNA fragmentation did not block the activation of JNK/SAPK and p38. Interestingly, these DEVD-type inhibitors did not block the Fas-induced morphological changes (cell shrinkage and surface blebbing), induction of Apo2.7 antigen, or the cell death (as assessed by the dye exclusion ability). These results suggest that the Fas-induced activation of the JNK/SAPK and p38 signaling pathways does not require CPP32-like proteases and that CPP32-like proteases, although essential for apoptotic nuclear events (such as chromatin condensation and DNA fragmentation), are not required for other apoptotic events in the cytoplasm or the cell death itself. Thus, the Fas signaling pathway diverges into multiple, separate processes, each of which may be responsible for part of the apoptotic cellular responses.

Allixin, a phytoalexin produced by garlic, and its analogues as novel exogenous substances with neurotrophic activity

Effects of allixin, a phytoalexin of garlic, and its analogues were studied on the survival and morphology of primary cultured neurons from fetal rat brain. Addition of allixin (1-100 ng/ml) to medium significantly promoted the survival of neurons derived from various regions of brain and increased the number of branching points per axon in hippocampal neurons. Allixin, however, was cytotoxic at higher concentrations (>1 microg/ml). Among the analogues of allixin, 2,6-dimethyl-3-hydroxy-4H-pyran-4-one (DHP) possessed potent neurotrophic activity at concentrations over 10 ng/ml without any obvious cytotoxicity up to 10 microg/ml. DHP also retained the activity to promote axonal branching. These results indicate that DHP is a novel exogenous low molecular weight neurotrophic substance without apparent cytotoxicity. This compound may be a useful prototype leading chemical for developing therapeutic and/or prophylactic drugs for neurodegenerative disorders.

Chromosome markers and alterations in mitotic cells from interspecific Citrus somatic hybrids analysed by fluorochrome staining

Mitotic cells from Rough lemon (Citrus jambhiri Lush.), Ohta ponkan (C. reticulata Blanco) and two somatic hybrid plants obtained from protoplast fusion were analysed by double staining with chromomycin A₃ (CMA) and 4'-6-diamidino-2-phenylindole. Only CMA-positive bands were observed in metaphasic chromosomes. The two parental karyotypes (2n=2x=18) were heteromorphic, yielding some marker chromosomes that could be identified in the somatic hybrids. One of the somatic hybrids had 2n=37 chromosomes, and the possible extra chromosome was distinguishable. The second somatic hybrid was tetraploid (2n=4x=36), with one of the chromosomes bearing a putative structural alteration. Furthermore, aneusomaty and some mitotic abnormalities were also observed in this latter plant. Such irregularities are reported for the first time for citrus somatic hybrids, and their possible causes and implications are discussed.

LOK is a novel mouse STE20-like protein kinase that is expressed predominantly in lymphocytes

We have identified a new gene, designated lok (lymphocyte-oriented kinase), that encodes a 966-amino acid protein kinase whose catalytic domain at the N terminus shows homology to that of the STE20 family members involved in mitogen-activated protein (MAP) kinase cascades. The non-catalytic domain of LOK does not have any similarity to that of other known members of the family. There is a proline-rich motif with Src homology region 3 binding potential, followed by a long coiled-coil structure at the C terminus. LOK is expressed as a 130-kDa protein, which was detected predominantly in lymphoid organs such as spleen, thymus, and bone marrow, in contrast to other mammalian members of the STE20 family. LOK phosphorylated itself as well as substrates such as myelin basic protein and histone IIA on serine and threonine residues but not on tyrosine residues, establishing LOK as a novel serine/threonine kinase. When coexpressed in COS7 cells with the known MAP kinase isoforms (ERK, JNK, and p38), LOK activated none of them in contrast to PAK- and GCK-related kinases. These results suggest that LOK could be involved in a novel signaling pathway in lymphocytes, which is distinct from the known MAP kinase cascades.

Activation of p38 MAP kinase pathway by erythropoietin and interleukin-3

Activation of p38 MAP kinase (p38) as well as JNK/SAPK has been described as being induced by a variety of environmental stresses such as osmotic shock, ultraviolet radiation, and heat shock, or the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-1 (IL-1). We found that the hematopoietic cytokines erythropoietin (Epo) and IL-3, which regulate growth and differentiation of erythroids and hematopoietic progenitors, respectively, also activate a p38 cascade. Immunoblot analyses and in vitro kinase assay clearly showed that Epo and IL-3 rapidly and transiently phosphorylated and activated p38 in Epo- or IL-3-dependent mouse hematopoietic progenitor cells. p38 can generally be activated by the upstream kinase MKK3 or MKK6. However, in vitro kinase assays in the immunoprecipitates with anti-MKK6 antibody and anti-phosphorylated MKK3/MKK6 antibody showed that activation of neither MKK3 nor MKK6 was detected after Epo or IL-3 stimulation, while osmotic shock clearly induced activation of both MKK3/MKK6 and p38. Together with previous observations, these results suggest that both p38 and JNK cascades play an important role not only in stress and proinflammatory cytokine responses but also in hematopoietic cytokine actions.