Altered expression of glutamate transporter-1 and water channel protein aquaporin-4 in human temporal cortex with Alzheimer's disease.

AIMS: Glutamate neurotoxicity plays an important role in the pathogenesis of various neurodegenerative disorders. Many studies have demonstrated that glutamate transporter-1 (GLT-1), the dominant astrocytic glutamate transporter, is significantly reduced in the cerebral cortex of patients with Alzheimer's disease (AD), suggesting that glutamate-mediated excitotoxicity might contribute to the pathogenesis of AD. In a previous study, we have demonstrated marked alterations in the expression of the astrocytic water channel protein aquaporin-4 (AQP4) in relation to amyloid ß deposition in human AD brains. As a functional complex, GLT-1 and AQP4 in astrocytes may play a neuroprotective role in the progression of AD pathology. However, few studies have examined the correlation between the expression of GLT-1 and that of AQP4 in human AD brain. METHODS: Here, using immunohistochemistry with antibodies against GLT-1 and AQP4, we studied the expression levels and distribution patterns of GLT-1 in areas showing various patterns of AQP4 expression in autopsied temporal lobes from eight patients with AD and five controls without neurological disorders. RESULTS: GLT-1 staining in the control group was present throughout the neocortex as uniform neuropil staining with co-localized AQP4. The AD group showed a significant reduction in GLT-1 expression, whereas cortical AQP4 immunoreactivity was more intense in the AD group than in the control group. There were two different patterns of GLT-1 and AQP4 expression in the AD group: (i) uneven GLT-1 expression in the neuropil where diffuse but intense AQP4 expression was evident, and (ii) senile plaque-like co-expression of GLT-1 and AQP4. CONCLUSIONS: These findings suggest disruption of glutamate/water homoeostasis in the AD brain.

A case of bilateral parietal cortical laminar necrosis with a loss of vertiginous sensation.

BACKGROUND: Animal experiments demonstrated that there are vestibular cortical areas at the parietal cortex. Moreover, in humans, recent functional neuroimaging studies revealed that caloric stimulation activated the parietoinsular vestibular cortex and optokinetic stimulation activated the parieto-occipital cortex. These activations indicate that the parietal vestibular areas play some role in nystagmus generation or in spatial information processing in the eye movement tasks. AIMS OF THE STUDY: The aim of this communication was to present a patient giving some information about parietal cortical function in nystagmus production and vertigo. CASE: We report a 51-year-old, heavy alcoholic man with Bálint syndrome, constructional disability, limb-kinetic apraxia and ideo-motor apraxia. Brain magnetic resonance imaging demonstrated bilateral parietal cortical laminar necrosis anterior to the parieto-occipital sulci without any involvement of the primary sensory and parietoinsular cortices. Optokinetic nystagmus (OKN) was not elicited whereas cold caloric stimulation fully evoked nystagmus toward the opposite side with oscillopsia when eyes opened. However, he did not feel vertiginous sensation when the eyes were closed. CONCLUSIONS: These findings suggest that the parietal cortices are indispensable for OKN production and vertiginous sensation.

Cloning and characterization of the antigenic membrane protein (Amp) gene and in situ detection of Amp from malformed flowers infected with Japanese hydrangea phyllody phytoplasma.

A Japanese hydrangea phyllody (JHP) disease found throughout Japan causes economic damage to the horticultural industry. JHP phytoplasma-infected Japanese hydrangea plants show several disease symptoms involved in floral malformations, such as virescence, phyllody and proliferation. Here, we cloned and characterized the antigenic membrane protein (Amp) gene homolog from the JHP phytoplasma (JHP-amp), expressed the JHP-Amp protein in Escherichia coli cells, and then obtained an antibody against JHP-Amp. The antibody against JHP-Amp had no cross-reactions with the antibody against the Amp protein from a closely related onion yellows phytoplasma. This serologic specificity is probably due to the high diversity of the hydrophilic domains in the Amp proteins. The in situ detection of the JHP-Amp protein revealed that the JHP phytoplasma was localized to the phloem tissues in the malformed flower. This study shows that the JHP-Amp protein is indeed a membrane protein, which is expressed at detectable level in the JHP phytoplasma-infected hydrangea.

Metabolic fate on 1-hexylcarbamoyl-5-fluorouracil and 5-fluorouracil in mice bearing ascites sarcoma 180.

Patterns of metabolism and disposition in plasma of tumor-bearing mice after oral administration of [6(-14)C]1-hexylcarbamoyl-5-fluorouracil ([6(-14)C]HCFU) resembled those in plasma of normal mice, but elimination of [6(-14)C]HCFU and 5-fluorouracil (FUra) was slower in tumor-bearing mice. The level of 1-(5-hydroxyhexylcarbamoyl)-5-fluorouracil (HHCFU) was lower in tumor-bearing mice. Also detected in plasma were [6(-14)C]HCFU, HHCFU, 1-(3-carboxypropylcarbamoyl)-5-fluorouracil, FUra, 5,6-dihydro-5-fluorouracil, and alpha-fluoro-beta-alanine. FUra originating from [6(-14)C]HCFU was retained over 6 hours, whereas intact FUra after [6(-14)C]FUra administration disappeared within 2 hours. The pattern of metabolism in ascitic fluid was similar to that in plasma after [6(-14)C]HCFU and [6(-14)C]FUra administration, but FUra was retained for a longer period in ascitic fluid. In sarcoma 180 cells, the maximum concentration of total radioactivity was observed 1 or 2 hours after [6(-14)C]FUra or [6(-14)C]HCFU administration, respectively, and the level of intact HCFU was very low. The principal metabolites were nucleotides that were maintained for a long period after administration of both compounds. The pattern of other metabolites after [6(-14)C]HCFU administration was also similar to that after [6(-14)C]FUra administration.

Murine lymphoma L5178Y cells resistant to purine antagonists: differences in cross-resistance to thioguanine-platinum(II) and selenoguanine-platinum(II).

To determine whether the antitumor activities of thioguanine-platinum(II) [TG-Pt(II)] and selenoguanine-platinum(II) [SeG-Pt(II)] are due to direct actions of these compounds or to the actions of their hydrolysis products, studies were made on a purine antagonist-resistant, murine lymphoma L5178Y/MP subline that lacked the anabolic enzyme hypoxanthine-guanine phosphoribosyltransferase necessary for tumor inhibition. The L5178Y/MP subline proved to be highly resistant to both TG-Pt(II) and thioguanine; the resistance ratios to the two compounds were almost identical. The subline showed high resistance to selenoguanine, but the cross-resistance to SeG-Pt(II) was negligible. Whether the compounds exhibit the delayed cytotoxicity characteristic of purine antagonists was also investigated. Delayed cytotoxicity was demonstrated for TG-Pt(II) as well as for thioguanine and other purine antagonists but not for SeG-Pt(II) or cis-dichlorodiammineplatinum(II). Experiments on cross-resistance and delayed cytotoxicity showed differences in the cytotoxicities of TG-Pt(II) and SeG-Pt(II): TG-Pt(II) exerted its activity through its hydrolysis product thioguanine, whereas SeG-Pt(II) compound was cytotoxic itself.

Relationship between antitumor effect and metabolites of 5-fluorouracil in combination treatment with 5-fluorouracil and guanosine in ascites sarcoma 180 tumor system.

The antitumor activity of 5-fluorouracil (FUra) against ascites Sarcoma 180 was significantly enhanced by coadministration of guanosine, and slightly by adenosine, but not by cytidine or uridine. In advanced ascites Sarcoma 180, guanosine also enhanced the action of FUra, but adenosine, uridine, and cytidine did not. The potentiation of antitumor activity by guanosine was reversed by addition of cytidine. The antitumor activity of FUra was significantly potentiated when guanosine was administered either 0 to 15 min before or 5 min after FUra. Changes in metabolites of FUra after potentiation by guanosine were investigated. Total radioactivity in the plasma was significantly decreased 10 min after the combined administration of [6-14C]FUra (3 mg/kg i.p.) and guanosine (100 mg/kg i.p.) in comparison with that of [6-14C]FUra alone and was slightly decreased by coadministration of [6-14C]FUra and adenosine. Conversely, it was significantly increased by uridine or cytidine. The decrease in total radioactivity in the plasma caused by guanosine was completely reversed by addition of cytidine. FUra, 5-fluorouridine, alpha-fluoro-beta-ureidopropionic acid, and alpha-fluoro-beta-alanine were found in the plasma. Intact FUra accounted for about 55% of the total radioactivity. The proportion of metabolites of [6-14C]FUra was not changed by coadministration of [6-14C]FUra and guanosine, adenosine, or cytidine, but the proportion of FUrd was increased by uridine. In the ascitic fluid, the total radioactivity derived from [6-14C]FUra was decreased by its combined administration with guanosine, and it was reversed by addition of cytidine. This pattern was similar to that in the plasma. The main FUra compound was intact FUra itself (90%), and 5-fluorouridine accounted for 1% of the total radioactivity in the ascitic fluid. On the other hand, total radioactivity of [6-14C]FUra in the tumor cells was significantly and slightly increased by guanosine and adenosine, respectively. Total radioactivity after [6-14C]FUra in combination with uridine or cytidine was less than that after [6-14C]FUra alone. Incorporation of [6-14C]FUra into RNA was increased about 3.7 times by its combination with guanosine in comparison with FUra alone, and it was increased 2.0, 0.6, and 0.7 times by adenosine, uridine, and cytidine, respectively. Moreover, FUra-nucleotides were significantly increased by guanosine. The increased radioactivity in RNA and FUra-nucleotides of tumor cells caused by guanosine was completely reversed by cytidine. These changes in incorporation into tumor cells were comparable to those in antitumor activity against ascites Sarcoma 180. The potentiation of antitumor activity of FUra by guanosine was considered to be due to an increase in incorporation of FUra into FUra-nucleotides and RNA in the tumor cells.

In vivo antitumor activity of multiple injections of recombinant interleukin 2, alone and in combination with three different types of recombinant interferon, on various syngeneic murine tumors.

We have used several transplantable experimental murine tumors to evaluate the potentiation of antitumor activity by a combination of human recombinant interleukin 2 (rHIL2) and recombinant interferons (rIFNs). The combination of rHIL2 and either human hybrid recombinant alpha-interferon A/D (rIFN-alpha A/D) or mouse recombinant beta-interferon (rIFN-beta) induced the s.c. adenocarcinoma 755, which had been established for 8 days, to regress, although rHIL2 or the rIFNs alone hardly inhibited the tumor's growth. Eight injections of the rHIL2-rIFN-alpha A/D combination cured 38% of the tumor-bearing mice. The rHIL2-rIFN-beta combination achieved a complete cure only when given in more than 13 injections. The administration of rHIL2 and mouse recombinant gamma-interferon (rIFN-gamma) markedly inhibited tumor growth of the s.c. established adenocarcinoma 755, but did not cure any of the mice. Other tumors, B16-F10 melanoma, and colon tumors 38 and 26 responded almost as well to a rHIL2-rIFN-alpha A/D or -beta combination, but not to a rHIL2-rIFN-gamma combination. The growth of Lewis lung carcinoma was inhibited to a lesser extent by all combinations, for which there were no long-term survivors. The combination therapy of rHIL2 and rIFN-beta produced a marked regression of the tumor in beige mice which have low natural killer activity, suggesting the activated natural killer cells not to be responsible for the therapeutic effect. And T-cell immunity may be important in the regression of s.c. established tumors, because of the lesser potentiation of antitumor activity in athymic mice. These results demonstrate that combination therapies of rHIL2 and rIFN-alpha A/D or -beta can function synergistically in the various s.c. established murine tumor systems and give further evidence in support of their clinical potential.

Mutagenicity of several classes of antitumor agents to Salmonella typhimurium TA98, TA100, and TA92.

The mutagenic activities of antitumor agents, including 5 antibiotics, 19 antimetabolites, 5 alkylating agents, 2 alkaloids, 1 enzyme, and 1 adrenal steroid hormone, were tested on Salmonella tyhimurium TA100, TA98, and TA92. Four of these, busulfan, carbazilquinone, 1-(4-amino-2-methylpyrimidine-5-yl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride, and pipobroman were shown for the first time to be mutagenic. Further, the known mutagenicities of five others, daunomycin hydrochloride, Adriamycin hydrochloride, mitomycin C, 6-mercaptopurine, and cyclophosphamide, were confirmed.

Amino acid sequence of an amyloidogenic Bence Jones protein in myeloma-associated systemic amyloidosis.

The complete amino acid sequence of an amyloidogenic Bence Jones protein (NIG-84) from an individual with myeloma-associated systemic amyloidosis has been determined. The protein, with a blocked N-terminus, represents a complete light chain consisting of 217 residues and it has a structural feature characteristic of the V lambda II subgroup. In addition to a two-residue insertion at positions 28 and 29, it has an additional rare insertion of alanine at position 100. NIG-84 is an example of the first complete sequence presented for the amyloidogenic Bence Jones protein of the V lambda II subgroup.

Specific detections of the early process of the glycation reaction by fructose and glucose in diabetic rat lens.

The glycation reaction by fructose, as well as that by glucose, in control and diabetic rat lens was analyzed by using antibodies which specifically recognize adducts of lysine with fructose and with glucose. Levels of fructose adducts in diabetic rat lens were 2.5 times that of the control, and correlated with sorbitol levels. This was mainly due to enhanced glycation of beta- and gamma-crystallins by fructose under diabetic conditions. These data suggest that glycation by fructose may also play a role in cataract formation under conditions of diabetes and aging.

Effect of (E)-5-(2-bromovinyl)-2'-deoxyuridine on life-span and 5-fluorouracil metabolism in mice with hepatic metastases.

5-Fluorouracil (5FU) is rapidly metabolised in the liver by dihydrouracil dehydrogenase. Bromovinyluracil is formed in the liver from (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) by pyrimidine nucleoside phosphorylase and is a potent inhibitor of dihydrouracil dehydrogenase. The co-administration of 5FU (intravenously) and BVDU (orally) was investigated in normal BDF1 mice and in those bearing liver metastases of Lewis lung carcinoma. 5FU alone rapidly disappeared from plasma and liver within 60 min of dosing. Administered with BVDU, 5FU persisted in plasma and liver for 60-180 min. The combination also significantly enhanced the life-span of tumour-bearing mice. 5FU plus BVDU may have therapeutic potential in the treatment of primary and secondary liver tumours.

Factors affecting mandibular complications in low dose rate brachytherapy for oral tongue carcinoma with special reference to spacer.

PURPOSE: To evaluate the efficacy of a spacer in the prevention of mandibular complications in low dose rate (LDR) brachytherapy (BRT) for oral tongue carcinoma. METHODS AND MATERIALS: A retrospective analysis was conducted using 103 patients with T1 or T2 tongue carcinoma treated by a single plane implantation of iridium (192Ir) pins between 1979-1994. Of these patients, 60 were treated by BRT alone, and the rest were combined with external irradiation (Ext) and/or chemotherapy (CHT). Forty-eight and 55 patients were given BRT with and without a spacer, respectively. Spacers were individually made of acrylic resin according to a prosthetic technique so as to obtain the thickness of 7-10 mm at the lingual part of the implanted side. Variables, including a spacer, which may be associated with the development of osteoradionecrosis (ORN) of the mandible, were analyzed by the Cox proportional hazards regression analysis. RESULTS: Our spacer reduced about 50% of the absorbed dose at the lingual side surface of the lower gingiva (LSG) to that in the absence of a spacer. Absolute incidence of ORN was 2.1% (1 of 48) and 40.0% (22 of 55), with and without a spacer, respectively, and the difference was statistically significant by univariate analysis (p = 0.0004). It was revealed by the Cox analysis that the spacer (p = 0.0247), combined CHT (p = 0.0295), and combined Ext (p = 0.0279) were significant independent factors associated with the development of ORN. The spacer was shown to be a significant factor by univariate analysis (p = 0.0037), but not by multivariate analysis when analysis was restricted to the patients who did not receive CHT. The absorbed dose, dose rate, and biological effective dose (BED) reflecting early or late response were estimated at the LSG, and prognosticators associated with the incidence of ORN were also determined by the Cox analysis. Particularly, BED for late response by BRT, the total absorbed dose, and any BED by Ext plus BRT were highly significant factors in the whole population. Essentially similar results were obtained in the patients without receiving CHT. CONCLUSIONS: It was clarified that our spacer effectively prevents mandibular complications in LDR BRT by 192Ir for oral tongue carcinoma. Furthermore, introduction of a spacer provided novel information concerning the development of ORN, where BED particularly for late response given by BRT, the total absorbed dose, and any BED by Ext plus BRT could be good prognostic factors only when estimated at the LSG.

Antitumor activity of 1,2-diaminocyclohexane--platinum complexes against sarcoma-180 ascites form.

Platinum complexes derived from three isomers of 1,2-diaminocyclohexane have been synthesized and their antitumor activities were evaluated against ascites Sarcoma-180. All the platinum complexes had high antitumor activity. Platinum complexes derived from cis-1,2-diaminocyclohexane were more effective than those derived from trans-l-and trans-d-1,2-diaminocyclohexane. Among the platinum complexes tested, oxalato(cis-1,2-diminocyclohexane)platinum had a remarkably high therapeutic index. Modification of the nonleaving group as well as that of the leaving group is important in order to find better antitumor platinum complexes.

Queuine analogues. Their synthesis and inhibition of growth of mouse L5178Y cells in vitro.

A variety of analogues of queuine (7-[(3S,4R,5S)-4,5-dihydroxycyclopent-1-en-3-ylaminomethyl]- 7 -deazaguanine), i.e., those with 7-N-substituted aminomethyl side chains and those in which the oxygen function at the 6 position of the 7-deazaguanine ring was replaced by sulfur, were synthesized and tested for ability to act as substrates for tRNA-guanine transglycosylase and for inhibitory effects on growth of mouse L5178Y leukemic cells in vitro. Of the compounds tested, analogues with sulfur at the 6 position of the 7-deazaguanine ring in place of oxygen or with an N-o-hydroxyphenyl, N-m-hydroxyphenyl, or iodoacetyl group in the 7-aminomethyl side chain in place of the naturally occurring cyclopentene diol moiety markedly inhibited the growth of cells at concentrations of 1-10 micrograms/mL, although queuine itself had practically no effect at a concentration of 100 micrograms/mL.

Improved colony formation of cultured retinoblastoma cells.

The effect of various components of three semi-solid media on colony formation in two representative retinoblastoma cell lines, Y-79 and WERI, was determined. Diethylaminoethyl dextran was found to be toxic to the cells, and was deleted from the medium. Horse serum was also used without heat treatment. In the most improved culture medium, plating efficiency was 28% for Y-79 cells and 14% for WERI cells, an increase of more than 10 times that of the original formula. In the new medium, both Y-79 and WERI cells showed relatively constant plating efficiency within a certain range, showing that the medium is useful for quantitative clonogenic study of retinoblastoma cells.

Effect of bis(bilato)-1,2-cyclohexanediammineplatinum(II) complexes on lung metastasis of B16-F10 melanoma cells in mice.

New platinum(II) complexes, bis(bilato)-1,2-cyclohexanediammineplatinum(II) which were lipophilic and water-miscible, were tested for antitumor activity against lung nodules from intravenously injected B16-F10 melanoma cells in C57BL/6 mice by intravenous administration of the complexes in water suspension form. Among them, DACHP(litho)2 and DACHP(urso)2 had high antitumor activity but others had no activity. The antitumor activity of DACHP(urso)2 was increased significantly by injecting it three times; T/C was over 280% with 100-day survivors of 3 of 6 mice tested. Large amounts of total platinum were found in lung and liver tissues by atomic absorption spectroscopy after single intravenous injection of DACHP(urso)2 suspension in ICR mice.

Antitumor activity and tissue distribution of bis(bilato)-1,2-cyclohexanediammineplatinum(II) complexes in BDF1 mice with murine reticulum cell sarcoma (M5076).

Murine reticulum cell sarcoma (M5076) was subcutaneously implanted into BDF1 mice and then the antitumor activity of seven micelle-forming type platinum complexes was tested. The antitumor activity of bis(hyodeoxycholato)-trans-(+/-)-1,2-cyclohexanediammineplatinu m(II)(t-DACHP (hyo)2) was highest (95% inhibition of growth), and it was dose dependent with a large therapeutic index. This was followed by bis-(chenodeoxycholato)-trans(+/-)(cis)-1, 2-cyclohexanediammineplatinum(II)(t(c)-DACHP-(cheno)2) (49% inhibition) and bis(ursodeoxy-cholato)-trans(+/-)-1,2-cyclohexanediammine platinum (II) (t-DACHP(urso)2) (48% inhibition). t-DACHP(hyo)2 and t-DACHP(urso)2 inhibited sarcoma 180 growth (63% and 33%, respectively). The organ distribution of the complex with the highest antitumor activity was compared with that of a complex with negligible antitumor activity. The total Pt levels were significantly higher in tumor tissue from mice given the more active complex than in tumor tissue from mice given the less active complex. Pt levels in the kidney and the spleen showed a similar pattern, but the lung tissue Pt levels were significantly higher in mice given the less active complex.

Mechanism of inhibition of phosphoribosylation of 5-fluorouracil by purines.

The mechanism of the abolishment of the cytotoxicity of 5-flurouracil by purines in L5178Y cells was determined by using phosphoribosylation enzymes for both 5-fluorouracil and hypoxanthine. Hypoxanthine inhibited the phosphoribosylation of 5-fluorouracil in the presence of both enzymes, but no inhibition by hypoxanthine was found without hypoxanthine phosphoribosyltransferase or at a high concentration of 5-phosphoribosyl 1-pyrophosphate (PRPP). Hypoxanthine, adenine and inosine decreased the intracellular concentration of PRPP to less than one-tenth of that of the control. These results suggest that 5-fluorouracil is activated directly to its nucleotide, 5-fluorouridine 5'-monophosphate, by the phosphoribosylation enzyme and that the inhibition of activation by purines is due to depletion of PRPP.

Enhancing effect of bromovinyldeoxyuridine on antitumor activity of 5-fluorouracil against adenocarcinoma 755 in mice. Increased therapeutic index and correlation with increased plasma 5-fluorouracil levels.

A marked inhibition of the growth of solid tumor adenocarcinoma 755 was achieved by the combination of 5-fluorouracil (5-FU) with bromovinyldeoxyuridine (BVDU). The therapeutic index (LD50/ED50) for the combination of BVDU plus 5-FU was 8.1 and 3.9 upon intraperitoneal (i.p.) or oral (p.o.) administration, respectively. The therapeutic index of i.p. 5-FU given alone was 2.3, whereas for p.o. 5-FU given alone no therapeutic index could be established because of insufficient activity of the compound. Thus, the therapeutic index of 5-FU increased significantly when combined with BVDU. Pharmacokinetic studies revealed that upon i.p. or p.o. 5-FU administration plasma 5-FU levels rapidly declined, but that, in the combination with BVDU, the plasma clearance of 5-FU, especially following p.o. administration, was slowed down considerably. Antitumor activity of 5-FU correlated with AUC (area under the concentration x time curve), within the plasma 5-FU concentration range from 0.02 to 0.4 microgram/ml.

Enhancing effect of bromovinyldeoxyuridine on antitumor activity of 5'-deoxy-5-fluorouridine against adenocarcinoma 755 in mice. Correlation with pharmacokinetics of plasma 5-fluorouracil levels.

5'-Deoxy-5-fluorouridine (DFUR), whether or not combined with (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) was pursued in BDF1 mice from both a pharmacokinetic viewpoint, following a single oral dose administration, and an anticancer viewpoint, following 5 daily oral doses in mice inoculated subcutaneously with adenocarcinoma 755 tumor cells. Half-life (t1/2) values for the elimination of DFUR and 5-fluorouracil (5-FU) from plasma following DFUR (100 mg/kg) administration were about 0.80 and 0.39 hr, respectively. Plasma 5-FU AUC (area under the curve) values following oral DFUR (100 mg/kg) was 0.224 micrograms.hr/ml. If DFUR (100 mg/kg) was combined with BVDU (10 mg/kg) the t1/2 and AUC values for 5-FU increased from 0.39 to 1.24 hr, and from 0.224 to 1.699 micrograms.hr/ml, respectively. Thus, BVDU significantly increased the plasma levels of 5-FU. It had no effect on the plasma levels of DFUR. At 100 mg/kg, DFUR did not show a significant antitumor activity. At 500 mg/kg it effected a 90% inhibition in tumor growth. When combined with BVDU (10 mg/kg), DFUR at 100, 200 and 300 mg/kg reduced tumor growth by 96, 100 and 100%, respectively. The antitumor activity achieved by DFUR, in the presence or absence of BVDU, correlated highly significantly with the AUC values for plasma 5-FU.