Two distinct c-ski cDNAs of fish, tilapia (Oreochromis aurea)

Two classes of tilapia c-ski cDNA (accession nos. AJ012011, AJ012012), designated as tski1 and tski2, respectively encoded a 687 and a 714 AA protein and shared a 57% AA identity. Comparison with the Ski proteins of chickens, humans and Xenopus, tilapia TSki polypeptides shared a 60, 57, and 57% (TSki1) and 67, 63, and 61% (TSki2) AA identity, respectively. The most and the least abundant c-ski mRNAs are located in the brain and the skeletal muscle, respectively. Both tski1 and tski2 were widely expressed in the adult tissues examined, but tski2 transcripts were at higher levels except in the ovary and oocytes: tski1 transcripts were predominant in the ovary, whereas tski2 transcripts were predominant in the testes. In the oocytes, the tski1 mRNA was a maternally-inherited stockpile that subsequently was degraded, so that the expression ratio of tski1 to tski2 transcripts declined gradually as the fish developed from oocyte to 4-cm fry. Mol. Reprod. Dev. 54:223- 231.

Subcutaneous leiomyosarcoma on the face

BACKGROUND

Cutaneous leiomyosarcoma is a rare soft tissue sarcoma with a predilection for the lower extremities. Leiomyosarcoma of the face is very rare. Subcutaneous leiomyosarcoma has a higher likelihood of recurrence and metastases than that of the superficial dermal type.

OBJECTIVE

The dermatologic surgeon and pathologist should be familiar with the characters of subcutaneous leiomyosarcoma.

METHODS

We report a case of subcutaneous leiomyosarcoma on the face with the results of histologic examination and immunohistochemical studies.

RESULTS

Leiomyosarcoma of the face is exceedingly rare. The deep subcutaneous type is thought to arise from the smooth muscle of the vascular wall. The neoplasm we report here has deep tumor invasion, high malignancy grade (3B), and large tumor size. Wide excision and postoperative radiotherapy were performed.

CONCLUSION

Subcutaneous leiomyosarcoma has a higher likelihood of recurrence and metastases than that of the superficial dermal type. The most effective treatment is wide excision with 3-5 cm lateral margins and a depth that includes subcutaneous tissue and fascia.

Purification, characterization and molecular cloning of trichoanguin, a novel type I ribosome-inactivating protein from the seeds of Trichosanthes anguina

The seeds of the plant Trichosanthes anguina contain a type I ribosome-inactivating protein (RIP), designated trichoanguin, which was purified to apparent homogeneity by the combined use of ion-exchange chromatographies, i.e. first with DE-52 cellulose and then with CM-52 cellulose. The protein was found to be a glycoprotein with a molecular mass of 35 kDa and a pI of 9.1. It strongly inhibits the protein synthesis of rabbit reticulocyte lysate, with an IC50 of 0.08 nM, but only weakly that of HeLa cells, with an IC50 of 6 microM. Trichoanguin cleaves at the A4324 site of rat 28 S rRNA by its N-glycosidase activity. The cDNA of trichoanguin consists of 1039 nt and encodes an open reading frame coding for a polypeptide of 294 amino acid residues. The first 19 residues of this polypeptide encode a signal peptide sequence and the last 30 residues comprise an extension at its C-terminus. There are four potential glycosylation sites, located at Asn-51, Asn-65, Asn-201 and Asn-226. A comparison of the amino acid sequence of trichoanguin with those of RIPs such as trichosanthin, alpha-momorcharin, ricin A-chain and abrin A-chain reveals 55%, 48%, 36% and 34% identity respectively. Molecular homology modelling of trichoanguin indicates that its tertiary structure closely resembles those of trichosanthin and alpha-momorcharin. The large structural similarities might account for their common biological effects such as an abortifacient, an anti-tumour agent and anti-HIV-1 activities. Trichoanguin contains two cysteine residues, Cys-32 and Cys-155, with the former being likely to be located on the protein surface, which is directly amenable for conjugation with antibodies to form immunoconjugates. It is therefore conceivable that trichoanguin might be a better type I RIP than any other so far examined for the preparation of immunotoxins, with a great potential for application as an effective chemotherapeutic agent for the treatment of cancer.

Single-unit activity of dorsomedial arcuate neurons and diurnal changes of tuberoinfundibular dopaminergic neuron activity in female rats with neonatal monosodium glutamate treatment

Neonatal monosodium glutamate (MSG)-treated rats were used in this study to answer two questions: (1) whether or not the dopamine-responsive dorsomedial arcuate (dm-ARN) neurons are tuberoinfundibular dopaminergic (TIDA) neurons, and (2) whether or not the remaining TIDA neurons in MSG-treated rats are functioning normally. MSG (4 mg/g b. wt., subcutaneously [s.c.]) or saline was given to neonatal Sprague-Dawley rats on days 1, 3, 5, 7, and 9 after birth. The female rats were ovariectomized at 50 days of age and treated with estrogen for 1 week before they were used between 65-90 days of age. The tyrosine hydroxylase-immunoreactive (TH-ir) neurons located in the dm and ventrolateral (vl) parts of the ARN were significantly reduced in MSG-treated rats, as determined by immunohistochemical method. Some TH-ir cells, however, were visible along the border of the third ventricle. Using single-unit recording in brain slices, we found that dopamine inhibited significantly fewer percentage of dm-ARN neurons in MSG-treated (28.2%, n = 39) than in saline-treated rats (73.3%, n = 15). In contrast, bombesin exhibited similar effects (over 70% excitation) in both groups. Using neurochemical means, neonatal MSG treatment produced significant decreases of both 3,4-dihydroxyphenylacetic acid and dopamine levels, but not their ratios, in the median eminence. Moreover, the diurnal change of TIDA neuronal activity persisted in the MSG-treated rats; so did the estrogen-induced afternoon prolactin surge. All these results indicate that neonatal MSG-treatment reduced the number and altered the location of TIDA and dopamine-responsive dm-ARN neurons. The remaining TIDA neurons seemed to be able to maintain their basal activities and diurnal rhythm.

The anti-herpes simplex virus activity of n-docosanol includes inhibition of the viral entry process

n-Docosanol-treated cells resist infection by a variety of lipid-enveloped viruses including the herpesviruses. Previous studies of the mechanism of action demonstrated that n-docosanol inhibits an event prior to the expression of intermediate early gene products but subsequent to HSV attachment. The studies reported here indicate that n-docosanol inhibits fusion of the HSV envelope with the plasma membrane. Evidence suggests that antiviral activity requires a time-dependent metabolic conversion of the compound. Cellular resistance to infection declines after removal of the drug with a t1/2 of approximately 3 h. Reduced expression of viral genes in n-docosanol-treated cells was confirmed by a 70% reduction in expression of a reporter gene regulated by a constitutive promoter inserted into the viral genome. Inhibited release in treated cells of virion-associated regulatory proteins--an immediate post entry event--was indicated by a 75% reduction in the expression of beta-galactosidase in target cells carrying a stably transfected lacZ gene under control of an HSV immediate--early promoter. Finally, the fusion-dependent dequenching of a lipophilic fluorescent probe, octadecyl rhodamine B chloride, inserted into the HSV envelope was significantly inhibited in treated cells. Inhibition of fusion between the plasma membrane and the HSV envelope, and the subsequent lack of replicative events, may be the predominant mechanism for the anti-HSV activity of n-docosanol.

Microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system

To investigate the microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system, aluminum alloys A356, AA 5052, AA 5083 and AA 6061 were chosen as the test alloys and Cladosporium and several fuel-oil contaminated microbes isolated in Taiwan were used as test organisms. Aluminum alloy AA 5083 in fuel-oil/aqueous system was the most susceptible material for microbial corrosion, then followed by aluminum alloys AA 5052 and A356, and AA 6061 was more resistant to microbial aggression. Mixed culture had high capability of corrosion, then followed by Penicillium sp. AM-F5, Fusarium sp. AM-F1, Pseudomonas aeruginosa AM-B5, Ps. fluorescens AM-B9, C. resinae ATCC 22712, Penicillium sp. AM-F2, Candida sp. AM-Y1 and Ps. aeruginosa AM-B11. From energy dispersive spectrometer analysis, aluminum and magnesium contents decreased in the corrosion area, while chlorine and sulfur contents increased. The major organic acid produced in fuel-oil/aqueous system was acetic acid, and the total organic acids content had a positive correlation with the degree of microbial corrosion.

Voltage- and use-dependent inhibition by amphetamine of field potentials and Na+ current in rat nucleus accumbens neurons

The psychostimulant amphetamine (AMPH) is known to act as an indirect dopamine agonist by promoting dopamine release. Here we demonstrate direct AMPH inhibition of field potentials and Na+ currents in rat nucleus accumbens (NAc) neurons. The experiments were done with field potential recordings from NAc slices and whole-cell recordings from isolated NAc neurons. In NAc slices, AMPH inhibited the field potentials. The inhibition increased when the NAc neurons were depolarized with higher extracellular K+ or when the field potentials were evoked at a higher rate. In isolated NAc neurons, AMPH inhibited the Na+ currents. The inhibition increased when Na+ currents were activated from more depolarized holding potentials or were activated more frequently. The voltage- and use-dependent inhibition of field potentials and Na+ currents by AMPH suggests a similar mechanism of AMPH action with local anesthetics and antiarrhythmic drugs.

TGF-beta2 inhibits growth of uveal melanocytes at physiological concentrations

The effect of TGF-beta2 on growth of uveal melanocytes in vitro was studied and the dose-dependent inhibitory effect of TGF-beta2 was compared with the known concentration of TGF-beta2 in aqueous humor. Uveal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor. The uveal melanocytes were plated into multi-well plates. After 24 hr, TGF-beta2 was added to the medium in various concentrations. After 5 days, the cells were detached, counted and compared to the controls. The effect of TGF-beta2 on DNA synthesis (as evaluated by uptake of bromodeoxyuridine) were also tested. TGF-beta2 inhibited growth and DNA synthesis of cultured uveal melanocytes in a dose-dependent manner at concentrations from 0.03-10.0 ng ml-1. The growth-inhibition of TGF-beta2 was present even in serum-free medium. TGF-beta2 had little or no effect on melanogenesis of cultured uveal melanocytes. The serum used for cultivation did not contain active TGF-beta1 or TGF-beta2 as measured by immunoassay. The known amount of active TGF-beta2 in aqueous humor (0.2-0.4 ng ml-1) is sufficient to inhibit the growth of uveal melanocytes. It indicates that TGF-beta2 is a potent growth inhibit factor of uveal melanocytes and may play an important role in maintaining the non-proliferative, relatively quiescence status of uveal melanocytes in vivo.

Sechiumin, a ribosome-inactivating protein from the edible gourd, Sechium edule Swartz--purification, characterization, molecular cloning and expression

A new ribosome-inactivating protein (RIP), sechiumin, was purified from the seeds of edible gourd, Sechium edule Swartz by gel-filtration and ion-exchange chromatography, with an apparent relative molecular mass of 27 kDa. It inhibits the protein synthesis of rabbit reticulocyte lysate strongly with a concentration causing 50% inhibition (IC50) of 0.7 nM, but has a much lower inhibitory effect on intact HeLa cells, with an IC50 of 5000 nM. Sechiumin has a highly specific RNA N-glycosidase activity towards 28S rRNA, as does the A-chain of abrin. It suggests that sechiumin is one of the type-I ribosome-inactivating proteins. The cDNA of sechiumin has been cloned and expressed using a pET expression system in Escherichia coli. The sechiumin cDNA has 951 nucleotides, encoding a protein with 285 amino acids. The amino acid sequence deduced from the cDNA reveals that the first 21 N-terminal amino acid residues constitutes a signal peptide. Sechiumin has nearly 60% similarity to several type-I RIPs purified from the Cucurbitaceae family, such as luffin-a (62.5%) and trichosanthin (64.8%), but less similarity to other type-I RIPs. Two amino acid residues, Glu160 and Arg163, at the putative active site of sechiumin, are known to be catalytically active in ricin and abrin. The N-terminal amino acid sequence of sechiumin is very similar to that of trichosanthin. The recombinant sechiumin was obtained as an insoluble protein, and the preparation of the active soluble form was achieved by renaturing the denatured protein. These studies suggest that the recombinant sechiumin could be used for the preparation of immunotoxin as a potential cancer chemotherapeutic agent.

The pitch of a mistuned harmonic: evidence for a template model

A harmonic of a periodic complex tone can be heard out as a separate entity if the harmonic is slightly mistuned from its correct frequency. Pitch matching experiments show that the pitch of such a mistuned harmonic differs systematically from its frequency. The shift in pitch is found to be an exaggeration of the frequency mistuning. This article considers two classes of model for the pitch shift. In the first class are tonotopically local interaction models which attribute the pitch shift to interactions between the mistuned harmonic and neighboring harmonics, where the neighborhood is established by peripheral filtering. The second class of model attributes the pitch shift to a contrast between the mistuned harmonic and a broadband harmonic template. This article describes six pitch matching experiments using complex tones having spectral gaps, strategically chosen to compare local interaction and template models. The results show that when a competition is set up between local interactions and a template, the template proves to be dominant. A parallel between the pitch shifts of mistuned harmonics and periodicity pitch, also attributed to a harmonic template, is seen as the frequency range of the mistuned harmonic is changed. Tonotopically local influences are evident in several experiments, but they are of secondary importance.

Bioactive kaurane diterpenoids from Annona glabra

Phytochemical analysis of the fruits of Annona glabra yielded two new kaurane diterpenoids, annoglabasin A (methyl-16 beta-acetoxy-19-al-ent-kauran-17-oate)(1) and annoglabasin B (16 alpha-hydro-19-acetoxy-ent-kauran-17-oic acid)(2), along with 11 known kaurane derivatives (3-13). The structures of the new compounds were established by spectral and chemical evidence. Among these, methyl-16 alpha-hydro-19-al-ent-kauran-17-oate (11) exhibited mild activity against HIV replication in H9 lymphocyte cells, and 16 alpha-17-dihydroxy-ent-kauran-19-oic acid (4) showed significant inhibition of HIV-reverse transcriptase.

Evidence for the ability of nucleophosmin/B23 to bind ATP

By taking advantage of its ability to be retained by ATP-agarose, we have demonstrated that nucleophosmin/B23 is capable of binding ATP. The specificity of the binding was confirmed by the absence of significant binding to AMP-agarose and by its loss when nucleophosmin/B23 in nuclear extracts was preincubated with ATP. Preincubation of the nuclear extracts with other ribonucleotide triphosphates (GTP, CTP, UTP) did not compete for the binding of nucleophosmin/B23 to ATP-agarose. The purified recombinant nucleophosmin/B23 was also able to be retained by ATP-agarose. The Kd for binding of ATP to the purified recombinant nucleophosmin/B23, on the basis of retention on a nitrocellulose membrane, was 86.5+/-8.3 microM; the number of binding sites was 0.68 per nucleophosmin/B23 protein molecule. To determine the possible ATP-binding site of nucleophosmin/B23, various deletion clones including the two mutants in which the putative ATP-binding sequence had been deleted were constructed. Deletion of the portions of the molecule (residues 83-152 and 185-240) had little effect on the ATP binding. The C-terminal deleted mutant (residue 242 to the C-terminus deleted) lost most of its ability to be retained by ATP-agarose and to bind [alpha-32P]ATP on a nitrocellulose membrane. The results indicate that the C-terminal portion (residues 242-294) contains the essential ATP-binding site of nucleophosmin/B23.

A 1 log N parallel algorithm for detecting convex hulls on image boards

By finding the maximum and minimum of {yi-mxi|1=or<i=or<N} for certain slopes m, we propose here a simple and fast parallel algorithm to obtain the convex hull of N arbitrarily given points on an image board, The mathematical theory needed is included, and computation time is 1 log N.

Regional gene mapping using mixed radiation hybrids and reverse chromosome painting

We describe a new approach for low-resolution physical mapping using pooled DNA probe from mixed (non-clonal) populations of human-CHO cell hybrids and reverse chromosome painting. This mapping method is based on a process in which the human chromosome fragments bearing a complementing gene were selectively retained in a large non-clonal population of CHO-human hybrid cells during a series of 12- to 15-Gy gamma irradiations each followed by continuous growth selection. The location of the gene could then be identified by reverse chromosome painting on normal human metaphase spreads using biotinylated DNA from this population of "enriched" hybrid cells. We tested the validity of this method by correctly mapping the complementing human HPRT gene, whose location is well established. We then demonstrated the method's usefulness by mapping the chromosome location of a human gene which complemented the defect responsible for the hypersensitivity to ionizing radiation in CHO irs-20 cells. This method represents an efficient alternative to conventional concordance analysis in somatic cell hybrids where detailed chromosome analysis of numerous hybrid clones is necessary. Using this approach, it is possible to localize a gene for which there is no prior sequence or linkage information to a subchromosomal region, thus facilitating association with known mapping landmarks (e.g. RFLP, YAC or STS contigs) for higher-resolution mapping.

Dimerization of the N-terminal amphipathic alpha-helix domain of the fungal immunomodulatory protein from Ganoderma tsugae (Fip-gts) defined by a yeast two-hybrid system and site-directed mutagenesis

A fungal immunomodulatory protein (Fip-gts) was purified from Ganoderma tsugae. The DNA encoding Fip-gts was isolated from a cDNA library of G. tsugae by reverse transcriptase-polymerase chain reaction. The complete amino acid sequence of Fip-gts, deduced from the nucleotide sequence of the cDNA, was the same as LZ-8 isolated from Ganodermn lucidum. Recombinant Fip-gts was expressed as a glutathione S-transferase fusion protein in Escherichia coli with a yield of 20 mg/liter of culture. Recombinant Fip-gts, purified to homogeneity, had the same blast formation stimulatory activity to human peripheral blood lymphocytes as native Fip-gts. The yeast two-hybrid system and site-directed mutagenesis were used to determine whether dimerization of Fip-gts occurred. Deletion analysis of the N-terminal amphipathic alpha-helix domain of Fip-gts identified a sequence of about 10 amino acids responsible for inducing immunomodulatory activity. Non-functional Fip-gts deletion mutants did not form dimers, whereas wild type Fip-gts did as determined by gel filtration. A mutant with deletions at Leu-5, Phe-7, and Leu-9 lost the amphipathic characteristics of the N-terminal domain and the ability to form dimers as well as its immunomodulatory activity. Fusion of Fip-gts with the DNA binding and the transactivation domains of GAL4 resulted in the activation of the lacZ activator gene, indicating the interaction of Fip-gts with it itself. The dimerization domain was further defined by analyzing the ability of the N-terminal 13 amino acids or Leu-5, Phe-7, and Leu-9 deletion mutants of Fip-gts to interact with the wild type Fip-gts. These experiments confirmed the N-terminal amphipathic alpha-helix as the dimerization domain and suggest that the dimerization of Fip-gts may play an important role in Fip-gts immunomodulatory activity.

A phase I feasibility and pharmacokinetic study of intrapleural paclitaxel in patients with malignant pleural effusions

To evaluate the feasibility and pharmacology of intrapleural (IP(L)) administration of paclitaxel, 18 patients with malignant pleural effusions were entered onto a phase I clinical study, 13 were caused by lung cancer. Following an effusion drainage rate of less than 100 ml/24 h and full expansion of the lung, patients were treated with a single instillation of pacilitaxel administered IP(L) in 500 ml of normal saline and retained for a maximum of 96h when tolerated. No systemic chemotherapy or ipsilateral thoracic irradiation was given for 4 weeks before and after the IP(L) treatment. The starting dose was 82.5 mg/m2 with the dose escalation schedule of 125, 175, 225 and 300 mg/m2. There were minimal local or systemic toxicities, such as local chest pain or myelosuppression, even when the paclitaxel dose reached 225 mg/m2. The pharmacological advantages of the IP(L) administration of paclitaxel were demonstrated by the mean exposure of the pleural cavity (area under the concentration time curve) to paclitaxel after IP(L) delivery exceeding that of the plasma by approximately 370-fold (range 55-684) and by the extraordinarily slow IP(L) clearance of paclitaxel (mean +/- SE 0.49 +/- 0.07 l/m2/day; range 0.08-1.16 l/m2/day) with significant concentrations of paclitaxel persisting within the cavity for more than 48-96 h after a single IP(L) instillation. In patients with detectable plasma paclitaxel levels, the plasma levels achieved exceed the minimal concentrations that are required to induce cytotoxic effects in vitro. Four patients had progressive dyspnea during IP(L) retention of paclitaxel solution because of treatment failure and needed drainage of effusion. One of these patients who was at the dose level of 225 mg/m2 originally had severely chronic obstructive lung disease, developed acute respiratory failure, refused mechanical ventilation support and succumbed to respiratory failure. No further patients were included after this event. Antitumor effect was shown by four of the 15 evaluable patients having no recurrence of effusion on chest radiograph at 1 month. Most of these responders had a good performance status, normal pretreatment pleural pH and/or glucose compared with the non-responders. We conclude that paclitaxel at a dose level of 175 or 225 mg/m2 is feasible for use intrapleurally. It could be considered for incorporation into treatment programs for patients with less advanced thoracic tumors with carcinomatous pleuritis or with IP(L) tumors following surgical debulking.

Molecular cloning and expression of a fungal immunomodulatory protein, FIP-fve, from Flammulina velutipes

FIP-fve, a fungal immunomodulatory protein, was isolated from the fruiting bodies of the edible mushroom, Flammulina velutipes. FIP-fve was shown to stimulate blast-forming activity of human peripheral blood lymphocytes and gene expression of interleukin-2, interferon-gamma and tumor necrosis factor-alpha. Repeated administration of FIP-fve to mice inhibits the Arthur and systemic anaphylaxis reactions. FIP-fve cDNA was cloned and sequenced, and the amino acid sequence of FIP-fve deduced from the nucleotide sequence is identical to that previously determined by protein sequencing. FIP-fve cDNA was amplified by polymerase chain reaction, ligated into the expression vector, pGEX-2T, and expressed in Escherichia coli as a fusion protein of glutathione S-transferase (GST) and FIP-fve. The GST-FIP-fve fusion protein was soluble, and the yield of recombinant FIP-fve was about 5 mg/L of induced culture. The recombinant FIP-fve was obtained by cleaving the GST-FIP-fve fusion protein with thrombin and purifing to homogeneity. The recombinant FIP-fve had about 50% of the immunomodulatory activity of the native FIP-fve.

Identification of amino acid residues of abrin-a A chain is essential for catalysis and reassociation with abrin-a B chain by site-directed mutagenesis

Abrin is a toxic protein consisting of two subunits, an enzymatic A chain (ABRaA) and a lectin-active B chain (ABRaB), linked by a disulfide bond. Site-directed mutagenesis was performed using PCR to study how the conserved amino acid residues, Tyr74, Tyr113, Glu164 and Trp198, around the active site of ABRaA are involved in enzyme catalysis, enzyme-substrate recognition and reassociation of ABRaA with ABRaB. The protein biosynthesis inhibitory activities of Y74F, Y113F and W198F were decreased moderately to that of wild type reABRaA, while that of E164Q decreased dramatically. Kinetic analysis showed that the kat of Y74F, Y113F and W198F resembled that of wild type, while the Km increased significantly. W198F did not reassociate with ABRaB to form heterodimers, while Y74F, Y113F and E164Q did. SDS-PAGE analysis of ABRaA treated with trypsin showed that reABRaA, Y74F, Y113F and E164Q survived digestion, whereas W198F was not protected from digestion. CD spectra revealed that W198F showed significant conformational changes. These observations suggest that E164 is directly involved in catalysis, and Tyr74, Tyr113 and Trp198 in substrate binding, while Trp198 also plays an important role in maintaining the conformation of ABRaA required for its reassociation with ABRaB.

Fip-vvo, a new fungal immunomodulatory protein isolated from Volvariella volvacea

A new fungal immunomodulatory protein (Fip) has been purified from the edible mushroom, Volvariella volvacea, and designated Fip-vvo. Analysis of the purified protein by SDS/PAGE followed by Coomassie Blue staining demonstrated that Fip-vvo is a single polypeptide with an apparent molecular mass of 15 kDa. Periodic acid/Schiff staining showed that this single polypeptide lacks carbohydrates. Using an in vitro bioassay measuring blast-formation stimulatory activity, Fip-vvo was shown to stimulate the maximum proliferation of human peripheral blood lymphocytes at a concentration of 5 microg/ml. Fip-vvo was capable of agglutinating rat red blood cells. Neither haemagglutination nor mitogenic activities were inhibited by mono- or dimeric sugars. In vivo, repeat administration of Fip-vvo greatly reduced the production of BSA-induced Arthus reaction in mice, whereas little effect was observed on the prevention of systemic anaphylaxis reactions. The selectively enhanced transcriptional expression of interleukin (IL)-2, IL-4, interferon-gamma, tumour necrosis factor-alpha, lymphotoxin and IL-2 receptor by Fip-vvo was also demonstrated by reverse transcriptase-PCR. This finding suggests that Fip-vvo exerts its immunomodulatory effects via cytokine regulation. In addition, the complete amino acid sequence of Fip-vvo was obtained by direct protein sequencing. This protein consists of 112 amino acid residues with a blocked N-terminal end and has a calculated molecular mass of 12667 Da not including the N-terminal blocking group. By gel filtration analysis, Fip-vvo exhibited a molecular mass of 26 kDa for the native molecules in PBS. This result indicates that native Fip-vvo is most likely a non-covalently associated homodimeric molecule.

On the Duifhuis pitch effect

An effect discovered by Duifhuis [J. Acoust. Soc. Am. 48, 888-893 (1970)], wherein an omitted high harmonic of a periodic complex tone is found to have an audible pitch, is extended to a variety of new broadband signal conditions. The effect is found to exist for flat spectra and spectra decreasing at 6 dB/octave, independent of phases as long as they are constant. The effect exists for alternating phases and Schroeder phases. It can generate a missing-fundamental pitch. Pitch and loudness matching experiments support the status of the omitted harmonic as an objective tone in the signal. Further experiments using narrower bands challenge the traditional explanation for the effect, which attributes it to short-term frequency analysis by peripheral auditory filters. Instead, the experiments suggest that different peripheral channels must be combined, maintaining some phase information, to generate the effect.

An ionizing radiation-sensitive CHO mutant cell line: irs-20. IV. Genetic complementation, V(D)J recombination and the scid phenotype

The genetic defect responsible for hypersensitivity of Chinese hamster ovary (CHO) irs-20 cells to ionizing radiation was found to be recessive in nature and could be complemented to produce wild-type radiosensitivity in irs-20/human hybrids. The radiosensitivities of six hybrid clones were determined based on their colony-forming ability under continuous irradiation at 6 cGy/h. A parallel cytogenetic analysis revealed a concordance between the presence or absence of human chromosome 8 and the resistant or sensitive phenotype. Confirming evidence was obtained using human chromosome 8-specific PCR primers. Positive amplification was obtained in hybrids with wild-type radiosensitivity, while no amplification was obtained in sensitive hybrids. Complementation analysis between radiosensitive CHO irs-20 and murine scid cell lines was carried out to determine whether the defects leading to their ionizing radiation hypersensitivity could be corrected by genetic complementation in the hybrids. Complementation did not occur. A transient V(D)J recombination assay after the introduction of the RAG1 and RAG2 genes indicated that the V(D)J recombination ability of the CHO irs-20 cells was about 10% of that for the CHO wild-type cells for signal join formation with an 80% joining fidelity and only 3% of the parental level for coding join formation. These data show that murine scid and irs-20 mutant hamster cells fall into the same complementation group and show similar defects in V(D)J recombination.

Establishment and characterization of an abrin-resistant cell line

An abrin-resistant cell line, CHOR 3-4, was isolated from CHOK1 cells which were resistant to a high concentration of abrin (160 ng/ml), and had a 1,000-fold higher resistance to abrin that of CHOK1 cells. CHOR 3-4 cells were about 25-fold more resistant than CHOK1 cells to the N-glycosidase activity of abrin, which was measured by hydrolyzing the N-glycosidic bond of adenine 4324 nucleotide from 3' end of mammalian 28S rRNA. However, the isolated polysomes of CHOR 3-4 cells had the same sensitivity to abrin as those of CHOK1 cells. On measuring the binding of 125I-abrin to CHOR 3-4 cells, it was decreased to about 20% that of CHOK1 cells. This indicates that the mechanism of the resistance of CHOR 3-4 to abrin is due to the alteration of glycoproteins or glycolipids of cell membrane.

Inhibitory effect of dopamine on dorsomedial arcuate neurons in rat brain slices: potentiation by coadministration of cocaine

Whether dopamine (DA) can have a direct effect on the tuberoinfundibular dopaminergic neurons has been a controversial issue. The present report used single-unit recording of neurons in dorsomedial region of the arcuate nucleus, where most tuberoinfundibular dopaminergic neurons are located, to study this question. By focusing our recording in this region, we found that DA in 25-250 nmol ranges inhibited a significant number of arcuate neurons tested (74.2% of 182 units). The inhibitory effect of DA was not only prominent in most cases, it also persisted in low Ca2+, high Mg2+ solution in several trials. Cocaine, a drug of abuse whose main effect is due to its inhibition of DA transporters and increasing the DA concentration in synaptic clefts, also inhibited a significant number of arcuate neurons by itself (51.5% of 97 units), although its effects were lesser than those of DA. Nevertheless, when coadministered with DA, cocaine significantly potentiated the inhibitory effect of DA in 82% of DA-responsive units (n = 39). These results clearly demonstrate that DA exhibits a predominantly inhibitory effect on presumed DA neurons in dorsomedial arcuate nucleus. The effects of cocaine further support this notion.

Endoscopic sympathectomy treatment for craniofacial hyperhidrosis

OBJECTIVE

To present endoscopic T-2 sympathectomy as a minimally invasive therapy for craniofacial hyperhidrosis (CH).

DESIGN

Follow-up study of 30 patients with CH treated by the new method in a 4-year period. The duration of follow-up was from 8 to 44 months (mean, 15 months).

SETTING

University hospital.

PATIENTS

Thirty consecutive patients with CH (18 men, 12 women) treated by the new method. All patients were essentially in good health except that they suffered from distressing CH to the extent that their daily activities were often disturbed. Their ages ranged from 7 to 63 years (mean age, 42.8 years).

INTERVENTION

Endoscopic sympathectomy on both sides was carried out in a 1-stage operation for all patients.

MAIN OUTCOME MEASURES

The patients were interviewed 1 week and then 3 months after surgery and then followed up by telephone interview about the alleviation or recurrence of CH and complications.

RESULTS

All of the treated patients obtained a satisfactory alleviation of CH. One case was complicated by a mild and transient ptosis of the left eye. No recurrence of CH was noticed during the follow-up period.

CONCLUSIONS

This therapeutic procedure is minimally invasive and effective. It causes minimal discomfort and was associated with no major complications in this series. The patients require only an overnight hospital stay and the operation scars are small. Endoscopic sympathectomy has proven to be an effective method in treating patients with distressing CH.