Dynamical ground state in the XY pyrochlore Yb2GaSbO7

The magnetic ground state of the pyrochlore Yb2GaSbO7 has remained an enigma for nearly a decade. The persistent spin fluctuations observed by muon spin relaxation measurements at low temperatures have not been adequately explained for this material using existing theories for quantum magnetism. Here we report on the synthesis and characterisation of Yb2GaSbO7 to elucidate the central physics at play. Through DC and AC magnetic susceptibility, heat capacity, and neutron scattering experiments, we observe evidence for a dynamical ground state that makes Yb2GaSbO7 a promising candidate for disorder-induced spin-liquid or spin-singlet behaviour. This state is quite fragile, being tuned to a splayed ferromagnet in a modest magnetic field μ 0 H c ∼ 1.5 T .

Cation, magnetic, and charge ordering in MnFe3O5

The recently-discovered high pressure material MnFe3O5 displays a rich variety of magnetically ordered states on cooling. Fe spins order antiferromagnetically below a Néel transition at 350 K. A second transition at 150 K marks Mn spin order that leads to spin canting of some of the Fe spins and ferrimagnetism. A further transition at 60 K is driven by charge ordering of Fe2+ and Fe3+ over two inequivalent Fe sites, with further canting of all spins. Electrical resistivity measurements reveal semiconducting behaviour in MnFe3O5 with a change in activation energy at 285 K.

The influence of urine volume on body impedance measurement

Bio-signal has some characteristics that the signal is so weak. So, it is good that the factors to influence measured electrical signal are eliminated as much as they can. So, in this paper we will show the influence of urine in bladder on measuring human body impedance. Human urine has different conductivity from other human tissues. Therefore, if the volume of the urine changed, the measured body impedance data also changed.So, in this paper, we will show the influence of urine in bladder with foot-to-foot and thigh-to-thigh current paths. As a result, if the current flows through human bladder, the influence of urine in the bladder must be considered when the body impedance is measured

Platelet count evaluation using three automated haematology analysers compared with the immunoplatelet reference method, and estimation of possible inadequate platelet transfusion

The accuracy of three automated haematology analysers [Sysmex XE-2100 (both optical and impedance mode), Bayer Advia 120, and Beckman Coulter LH-750] was compared with the immunoplatelet reference method for platelet measurement. A total of 165 blood specimens were obtained from patients and platelet counts were determined using the four-automated haematology analyser methods and the immunoplatelet reference method. The coefficients of determination (R(2)) between the automated haematology analyser methods and the immunoplatelet reference method for the overall platelet range were >0.98. A bias study, however, showed some disagreement. The use of a coincidence correction calculation for the immunoplatelet method did not improve the correlation between the immunoplatelet method and the automated haematology analyser methods. To estimate the possibility of inadequate platelet transfusion, the number of prophylactic platelet transfusion indications determined by the automated haematology analyser platelet counts were compared with the number of transfusion indications according to the platelet counts determined by the immunoplatelet method. An additional 48 blood specimens were included in this analysis. All of the automated haematology analysers showed some disagreement in the transfusion indications when compared with the immunoplatelet method, suggesting the possibility of inadequate platelet transfusion.

Coherent control of high-order harmonics with chirped femtosecond laser pulses

High-order harmonics were coherently controlled using chirped femtosecond laser pulses for the production of sharp and strong harmonics. As the laser intensity was increased above the saturation intensity for optical-field ionization, the laser chirp needed to suppress harmonic chirp in the plateau region changed from positive to negative. We showed that the modification of a laser chirp condition in a rapidly ionizing medium should be included for the proper coherent control of high-order harmonics, necessitating the integral treatment of the interaction between atoms and a driving laser pulse.

The role of the pars recta and pars oblique of cricothyroid muscle in speech production

To evaluate the functional difference of the pars recta and pars oblique during speech production, the electromyographic activities of these muscles were measured in thyroidectomized patients. The hooked wire electrodes were inserted into the normal side of the bellies of the pars recta and pars oblique bundles. Two kinds of sentences were used to obtain pitch changes, a simple interrogative sentence and a complex sentence with stress contrasts. The pars recta and pars oblique were simultaneously activated for initial lengthening and tensing of vocal folds to produce speech. The pars oblique might be initially more active than the pars recta at the initial task of speech and the pars recta might be more active at the pitch elevation in the interrogative sentence and the stress contrast of the complex sentence. The maximum electromyographic activity range of the pars recta and pars oblique seemed to be nearly equal. These results demonstrated that the patterns of electrical activities of the two bellies are different during speech and the combined activities of the pars recta and pars oblique are important in the adjustment of the vocal fold length during speech.

Chloroplast DNA phylogeography of Cunninghamia konishii (Cupressaceae), an endemic conifer of Taiwan

In this study, we investigated the genetic structure and phylogeographic pattern of the genus Cunninghamia, a member of the Cupressaceae restricted to mainland China and Taiwan, based on sequences of the trnD-trnT noncoding spacer of the chloroplast DNA. Maternal inheritance of chloroplasts was determined experimentally. No paternal leakage was detected. Both parsimony and neighbor-joining analyses revealed the polyphyly of Cunninghamia konishii, populations of which were nested in clades of C. lanceolata from mainland China. The nucleotide diversity of chloroplast DNA sequences within C. konishii (0.0118) was higher than that between species (0.0104), which agrees with a previous allozyme investigation. Based on mutational differences between sequences, a minimum spanning network consisting of five clades was constructed. Significant genetic differentiation (phiST = 0.130, P < 0.001) was detected between the clades based on AMOVA analyses. We infer several possible refugia in the Yunnan, Zhejiang, and Guangdong provinces of south China, all located in the minimum network as interior nodes. We also infer possible migration routes of Cunninghamia populations. The phylogeographic pattern shown in the reconstructed network suggests that the present-day Cunninghamia populations in Taiwan were derived from six different sources in continental Asia via long-distance seed dispersal. A migrant-pool model explains the heterogeneous composition of the organelle DNA in Taiwan's populations and the low differentiation between populations of Taiwan and China (phiCT = 0.012, P = 0.454). In contrast with the genetic heterogeneity within geographic populations, many local populations have attained coalescence at the trnD-trnT alleles, which has led to significant differentiation at the population level.

In vitro development of reconstructed bovine embryos and fate of donor mitochondria following nuclear injection of cumulus cells

In this study we examined the developmental potential of reconstructed embryos and the fate of donor mitochondria during preimplantation development after nuclear transfer in cattle. Isolated cumulus cells were used as donor cells in nuclear transfer. Cumulus cells labelled with MitoTracker Green FM fluorochrome were injected into enucleated bovine MII oocytes and cultured in vitro. MitoTracker labelling on donor cells did not have a detrimental effect on blastocyst formation following nuclear transfer. Cleavage rate was about 69% (56/81) and blastocyst formation rate was 6.2% (5/81) at 7 days after nuclear transfer. The labelled mitochondria dispersed to the cytoplasm and became distributed between blastomeres and could be identified up to the 8- to 15-cell stage. Small patches of mitochondria were detected in some 8- to 15-cell stage embryos (5/20). However, donor mitochondria were not detected in embryos at the 16-cell stage and subsequent developmental stages. In the control group, mitochondria could be identified in arrested 1-cell embryos up to 7 days after nuclear transfer. These results suggest that disappearance of the labelled donor mitochondria in nuclear transfer bovine embryos is not due to fading of the fluorochrome marker, but is rather an as yet undefined cytoplasmic event.

Anterior and posterior medialization (APM) thyroplasty

OBJECTIVE

In unilateral vocal fold paralysis with dysphonia, most of the paralyzed vocal folds may be medialized effectively by medialization laryngoplasty. However, if the posterior glottal gap is wide, these procedures may sometimes have a limit to medialize the posterior glottis and cannot be effective for acceptable voice quality. The objective of this study is to introduce a new surgical technique for medializing the membranous and cartilaginous portions of the paralyzed vocal fold: anterior and posterior medialization (APM) thyroplasty.

METHOD

Six patients underwent APM thyroplasty. They completed preoperative and postoperative evaluation with acoustic analysis and video laryngoscopy.

RESULTS

All patients satisfied their voice subjectively after surgery. The paralyzed vocal folds, membranous and cartilaginous parts, were medialized well, and the paralyzed arytenoid showed less anterior tipping postoperatively. On voice analysis all patients showed prolonged phonation times and decreased perturbations after surgery.

CONCLUSION

The advantages of this procedure are to medialize the membranous and cartilaginous portions of the paralyzed vocal fold directly and to correct vertical mismatch between two vocal folds. This procedure might be especially indicated in the lateralized position of the paralyzed vocal fold but not in the higher paralyzed vocal fold compared with the normal vocal fold.

4-Acetyl-12,13-epoxyl-9-trichothecene-3,15-diol isolated from the fruiting bodies of Isariajaponica Yasuda induces apoptosis of human leukemia cells (HL-60)

The fruiting bodies of Isaria fungi have been traditionally used in Korea to treat cancer. An apoptosis-inducing compound, 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol, was isolated from the methanol extract of fruiting bodies of Isaria japonica Yasuda by bioassay-guided fractionation. The apoptosis of the human leukemia cells (HL-60) by the compound was accessed by propidium iodide-staining flow cytometric analysis, and apoptosis-inducing activity at IC50 concentration (10 nmol/l) was further confirmed by a nuclear morphological change, a ladder pattern of internucleosomal DNA fragmentation, and an activation of caspase-3.

Revisiting the role of Ca2+ in Shaker K+ channel gating

Shaker K+ channels were expressed in outside-out macropatches excised from Xenopus oocytes, and the effects on gating of removal of extracellular Ca2+ were examined in the complete absence of intracellular divalent cations. Removal of extracellular Ca2+ by perfusion with EDTA-containing solution caused a small negative shift in the channel's voltage-activation curve and led to an increased nonselective leak, but did not otherwise alter or disrupt the channels. The results contradict the proposal that Ca2+ is an essential component required for maintenance of ion selectivity and proper gating of Kv-type K+ channels. The large nonselective leak in Ca2+-free conditions was found to be a patch-seal phenomenon related to F- ion in the recording pipette.

Deletion of cytosolic phospholipase A(2) suppresses Apc(Min)-induced tumorigenesis

Although nonsteroidal antiinflammatory drugs (NSAIDs) show great promise as therapies for colon cancer, a dispute remains regarding their mechanism of action. NSAIDs are known to inhibit cyclooxygenase (COX) enzymes, which convert arachidonic acid (AA) to prostaglandins (PGs). Therefore, NSAIDs may suppress tumorigenesis by inhibiting PG synthesis. However, various experimental studies have suggested the possibility of PG-independent mechanisms. Notably, disruption of the mouse group IIA secretory phospholipase A(2) locus (Pla2g2a), a potential source of AA for COX-2, increases tumor number despite the fact that the mutation has been predicted to decrease PG production. Some authors have attempted to reconcile the results by suggesting that the level of the precursor (AA), not the products (PGs), is the critical factor. To clarify the role of AA in tumorigenesis, we have examined the effect of deleting the group IV cytosolic phospholipase A(2) (cPLA(2)) locus (Pla2g4). We report that Apc(Min/+), cPLA(2)(-/-) mice show an 83% reduction in tumor number in the small intestine compared with littermates with genotypes Apc(Min/+), cPLA(2)(+/-) and Apc(Min/+), cPLA(2)(+/+). This tumor phenotype parallels that of COX-2 knockout mice, suggesting that cPLA(2) is the predominant source of AA for COX-2 in the intestine. The protective effect of cPLA(2) deletion is thus most likely attributed to a decrease in the AA supply to COX-2 and a resultant decrease in PG synthesis. The tumorigenic effect of sPLA(2) mutations is likely to be through a completely different pathway.

Simultaneous measurement of 89Sr and 90Sr in aqueous samples by liquid scintillation counting using the spectrum unfolding method

Two radiostrontium isotopes, 89Sr and 90Sr, were measured simultaneously by liquid scintillation counter coupling with a full spectrum DPM counting protocol. Strontium was separated from the aqueous media by extraction chromatography using Sr-spec resin. Individual count rates were evaluated from quench correlation curves for 89Sr and 90Sr related with SIS and tSIE quench indicators. The method exhibited a counting efficiency of 95% for 89Sr and 92% for 90Sr within their full energy channels and gave highly precise results when the sample was counted within 4 h after strontium separation. Lower limits of detection were 37 mBq/l for 90Sr and 32 mBq/l for 89Sr with a 60 min counting time.

Arytenoid appearance and vertical level difference between the paralyzed and innervated vocal cords

OBJECTIVES/HYPOTHESIS

In unilateral vocal fold paralysis, it has been generally accepted that the paralyzed vocal fold presents at a higher level than a normally innervated vocal fold. In this study, we correlate the appearances of the paralyzed arytenoid and the differences in level between the paralyzed and innervated vocal folds.

STUDY DESIGN

Retrospective review using video-recorded images of larynx.

METHODS

A total of 38 patients were selected for this study who reported symptoms of voice change attributable to a paralyzed vocal fold unilaterally. Video recordings were obtained using the laryngeal telescope. The heights were assessed according to the paralyzed positions, status (inspiration or phonation), and appearances of the paralyzed arytenoid. The appearances of paralyzed arytenoid were further clarified as the portions of the medial surface of the arytenoid that were visualized.

RESULTS

In medial paralysis, the paralyzed vocal fold appeared mainly as being at an equal vertical level or as having no distinct difference from normal vocal fold during phonation. However, a few cases of medial paralysis showed a lower than normal or higher than normal vocal fold during phonation, depending on the appearance of the paralyzed arytenoid. In lateral paralysis, most of the paralyzed vocal folds were not higher than the innervated vocal folds during phonation.

CONCLUSIONS

The heights of paralyzed vocal folds were variable depending on the paralyzed positions, the status of the larynx, and appearances of the paralyzed arytenoid. The fact that the paralyzed vocal fold is at a higher level than the normal vocal fold should be reconsidered.

Soft-x-ray emission from small-sized Ne clusters heated by intense, femtosecond laser pulses

Soft-x-ray emission from a cryogenically cooled Ne jet irradiated by intense, 25-fs laser pulses was measured. The Ne spectrum started to drastically change in emitting ions from Ne5+ to Ne7+ below the preexpansion temperature of -120 degrees C. The significant change in the spectrum is attributed to the collisional heating of small-sized Ne clusters formed in the cooled jet. The increase of the laser pulse length from 25 fs to 100 fs resulted in further increase of x-ray emission from Ne7+ states.

Intravascular papillary endothelial hyperplasia in a vascular lesion of the paranasal sinus

Intravascular papillary endothelial hyperplasia (IPEH) is usually a cutaneous lesion thought to represent a peculiar manifestation of an organizing thrombus. The principal significance of IPEH is its microscopic resemblance to angiosarcoma and possible misinterpretation as such. The occurrence of IPEH in the paranasal sinus is exceedingly rare. In this article, we report the first case to our knowledge of IPEH in a vascular lesion that originated from the ethmoid sinus and extended into the sphenoid sinus and sella. Despite the benign nature of this lesion, it could have been mistaken for a malignant tumor because of its clinical course and radiologic findings.

The Mom1AKR intestinal tumor resistance region consists of Pla2g2a and a locus distal to D4Mit64

The Mom1 (Modifier of Min-1) region of distal chromosome 4 was identified during a screen for polymorphic modifiers of intestinal tumorigenesis in ApcMin/+ mice. Here, we demonstrate that the Mom1AKR allele consists of two genetic components. These include the secretory phospholipase Pla2g2a, whose candidacy as a Mom1 resistance modifier has now been tested with several transgenic lines. A second region, distal to Pla2g2a, has also been identified using fine structure recombinants. Pla2g2aAKR transgenic mice demonstrate a modest resistance to tumorigenesis in the small intestine and a very robust resistance in the large intestine. Moreover, the tumor resistance in the colon of Pla2g2aAKR animals is dosage-dependent, a finding that is consistent with our observation that Pla2g2a is expressed in goblet cells. By contrast, mice carrying the distal Mom1 modifier demonstrate a modest tumor resistance that is confined to the small intestine. Thus, the phenotypes of these two modifier loci are complementary, both in their quantitative and regional effects. The additive effects and tight linkage of these modifiers may have been necessary for the initial identification of the Mom1 region.

Intraoral Removal of the Submandibular Gland: A New Surgical Approach

The transcervical procedure used for treating sialolithiasis in the submandibular gland has been generally accepted by head and neck surgeons. However, several clinical problems after surgery through the transcervical approach have been described. We introduce a new surgical approach for excision of the submandibular gland indicated in the chronically inflamed salivary gland with or without calculus and benign mixed tumor of the submandibular gland. Thirty-one cases of submandibular gland excision through the intraoral approach were reviewed, analyzing surgical technique and morbidity. Early postoperative discomforts developed, such as a temporary lack of function of lingual nerve and a temporary limitation of tongue movement, but recovery was within a short period of time in all patients involved. No symptomatic late complications appeared, such as residual inflammation of Wharton's duct and neurologic sequelae. We suggest that this approach can be extended to the excision of the submandibular gland as an alternative to the transcervical approach. The major advantages of this approach are the avoidance of an external scar and injury to the marginal mandibular nerve or the hypoglossal nerve.

Germline mutations of the dpc4 gene in Korean juvenile polyposis patients

Juvenile polyposis is an uncommon condition characterized by the development of multiple (usually more than 5) juvenile polyps in the gastrointestinal tract, especially in the colon. This disease usually occurs during childhood, and is inherited in an autosomal dominant fashion. It has been suggested that the dpc4 (deleted in pancreatic carcinoma, locus 4) gene, which is located on chromosome 18q21.1, might cause juvenile polyposis. The dpc4 (smad4) gene is a candidate tumor-suppressor gene and may play a role in the TGF-beta-signaling pathway. To confirm the idea that alterations of the dpc4 gene may result in juvenile polyposis, we screened 5 Korean juvenile-polyposis patients by PCR-SSCP (single-strand conformation polymorphism) analysis and bi-directional sequencing. There were germline mutations of the dpc4 gene in 3 out of the 5 patients: 2 had a genetic alteration in exon 9 and the third had a mutation in exon 8. These germline mutations occurred in the C-terminus of the dpc4 gene, similar to most published mutations. One patient exhibited a non-sense mutation (codon 388), which changed a glutamine codon (CAG) to a stop codon (TAG). The second patient harbored a mis-sense mutation (codon 390), causing a non-conservative amino-acid change <glutamate (GAA) to lysine (AAA)>. The third patient had a mis-sense mutation in exon 8 (codon 361), which altered an arginine codon (CGC) into a histidine codon (CAC).

Effects of dietary zinc deficiency on homocysteine and folate metabolism in rats

In rats, zinc deficiency has been reported to result in elevated hepatic methionine synthase activity and alterations in folate metabolism. We investigated the effect of zinc deficiency on plasma homocysteine concentrations and the distribution of hepatic folates. Weanling male rats were fed ad libitum a zinc-sufficient control diet (382.0 nmol zinc/g diet), a low-zinc diet (7.5 nmol zinc/g diet), or a control diet pair-fed to the intake of the zinc-deficient rats. After 6 weeks, the body weights of the zinc-deficient and pair-fed control groups were lower than those of controls, and plasma zinc concentrations were lowest in the zinc-deficient group. Plasma homocysteine concentrations in the zinc-deficient group (2.3 +/- 0.2 micromol/L) were significantly lower than those in the ad libitum-fed and pair-fed control groups (6.7 +/- 0.5 and 3.2 +/- 0.4 micromol/L, respectively). Hepatic methionine synthase activity in the zinc-deficient group was higher than in the other two groups. Low mean percentage of 5-methyltetrahydrofolate in total hepatic folates and low plasma folate concentration were observed in the zinc-deficient group compared with the ad libitum-fed and pair-fed control groups. The reduced plasma homocysteine and folate concentrations and reduced percentage of hepatic 5-methyltetrahydrofolate are probably secondary to the increased activity of hepatic methionine synthase in zinc deficiency.

Diplophonia in unilateral vocal fold paralysis and intracordal cyst

Diplophonia is the production by the voice of 2 separate tones through quasiperiodic variations in the vocal fold vibration (Ward PH, Moore GP. Ann Otol Rhinol Laryngol 1969;78:771-7). Clinically, diplophonia can be observed in patients with unilateral vocal fold paralysis with incomplete glottal closure and a mass lesion of the vocal fold, intracordal cyst, and granuloma (Kiritani S, et al. Ann Bull RILP 1991;25:55-62; Hirano M, et al. Ann Otol Rhinol Laryngol 1989;98:791-5). In this study we report 16 subjects with unilateral vocal cord paralysis or an intracordal cyst characterized perceptually by diplophonia. Diplophonia during tension imbalance may occur after surgery and is characterized by an improved perceptual score, a reduced number of vibratory cycles in each quasiperiodic waveform, and a reduced occurrence rate of the diplophonic waveform. During mass imbalance, no diplophonia occurred after surgery. Regarding the relationship of diplophonia with glottal condition at production of stops, in our study diplophonia varied significantly according to the different phonologic environments of stops during tension imbalance. We presume that there is a close relationship between the occurrence of diplophonia and the glottal conditions in tension imbalance, but not in mass imbalance.

Radiological appearance of primary branchial cleft cyst carcinoma

The hypothesis that primary branchiogenic carcinoma originates from a branchial cleft cyst is controversial. Many reports regarding primary branchiogenic carcinoma failed to provide sufficient evidence to distinguish it from metastatic cervical lymph nodes arising from previously unrecognized primary tumours. The radiological appearance of malignant transformation from a branchial cleft cyst has not been reported previously in the English literature. A radiological study is presented that confirms the primary branchiogenic carcinoma. The management in suspected cases would be wide surgical excision of the tumour including ipsilateral radical neck dissection followed by radiation therapy.

Folate and homocysteine metabolism in copper-deficient rats

To investigate the effect of copper deficiency on folate and homocysteine metabolism, we measured plasma, red-cell and hepatic folate, plasma homocysteine and vitamin B-12 concentrations, and hepatic methionine synthase activities in rats. Two groups of male Sprague-Dawley rats were fed semi-purified diets containing either 0. 1 mg (copper-deficient group) or 9.2 mg (control group) of copper per kg. After 6 weeks of dietary treatment, copper deficiency was established as evidenced by markedly decreased plasma and hepatic copper concentrations in rats fed the low-copper diet. Plasma, red-cell, hepatic folate, and plasma vitamin B-12 concentrations were similar in both groups, whereas plasma homocysteine concentrations in the copper-deficient group were significantly higher than in the control group (P<0.05). Copper deficiency resulted in a 21% reduction in hepatic methionine synthase activity as compared to the control group (P<0.01). This change most likely caused the increased hepatic 5-methyltetrahydrofolate and plasma homocysteine concentrations in the copper-deficient group. Our results indicate that hepatic methionine synthase may be a cuproenzyme, and plasma homocysteine concentrations are influenced by copper nutriture in rats. These data support the concept that copper deficiency can be a risk factor for cardiovascular disease.

Functional differences between the two bellies of the cricothyroid muscle

The contraction of the cricothyroid (CT) muscle, which results in a decrease in the distance between the thyroid and cricoid cartilages, is considered to be the main factor in lengthening the vocal folds. This is achieved by rotation of the CT joint. The CT muscle is composed of two distinct bellies, the pars recta and the pars obliqua. The function of each subunit is not clearly understood, although it is believed that they act differently because their fibers run in different directions. To clarify the function of the two bellies in phonation, the fundamental frequency (F0), vocal intensity, subglottic pressure, vocal fold length, and CT distance were measured using an in vivo canine laryngeal model. On the basis of these measurements, we demonstrated that the two bellies are varied in their effect on raising the pitch, rotation, and forward translation of the CT joint. The stimulation of the pars recta nerve resulted in a greater increase in the F0 value compared with that of pars obliqua. The combined activity of the pars recta and pars obliqua is important in adjustment of the vocal fold length. The CT approximations directed parallel to the pars recta and pars obliqua simultaneously were more effective in elevation of the pitch than the approximation placed parallel to the pars recta only. This finding may be clinically significant with regard to CT approximation thyroplasty in human trails.

Identification of a novel Salmonella invasion locus homologous to Shigella ipgDE

Genes essential for Salmonella typhimurium invasion have been localized to Salmonella pathogenicity island 1 (SPI1) on the chromosome. However, it is clear that other genes are required for the invasion process. Mutations that abolish the SPI1 invasion type III secretion system do not significantly reduce invasion into Chinese hamster ovary tissue culture cells. Two invasion defective mutants were isolated by screening 2,500 Tn10dTc insertion mutants of S. typhimurium in the tissue culture invasion assay. One of the invasion mutants, SVM167, has an insertion between centisomes 24.5 and 25.5 in an operon homologous to the ipgDEF operon of the Shigella flexneri and Shigella sonnei virulence plasmid. A second mutant, SVM168, has an insertion in an IS3-type element with homology to the Salmonella enteritidis IS1351 element and Yersinia enterocolitica IS1400 element from a high-pathogenicity island. Further characterization of SVM167 showed that culture supernatants from this mutant lack a previously uncharacterized protein that is also missing from culture supernatants of a SPI1 mutant, suggesting it can be secreted by the SPI1 type III secretion system. In addition, transcription of this operon, sigDE (Salmonella invasion gene), is dependent on the presence of sirA, an activator of hilA expression. HilA activates transcription of several of the SPI1 genes but does not appear to have a major role in activation of transcription from the sigDE promoter.

Chondrolipoma of the nasopharynx

Lipoma is the commonest soft-tissue tumour arising anywhere in the body, but its occurrence in the nasopharynx is extremely rare. Only four cases in adults have been previously reported in the English literature. We describe a 63-year-old woman with a nasopharyngeal mass that was removed transorally and verified histopathologically as chondrolipoma, that is a lipoma with chondroid metaplasia.

Extended canine laryngeal preservation for transplantation

The goal of successfully transplanting the larynx has motivated researchers since the 1960s. Early laryngeal transplant techniques limited the donor larynx to 45 minutes of ischemia. In this study, a method of prolonged laryngeal preservation is employed in three canines. In vivo cold laryngeal perfusion with University of Wisconsin Solution (UWS) was performed. The larynx was removed and placed into cold storage in 4 degrees C UWS. After 24 hours of storage, the same canines underwent laryngeal reimplantation. The animals were sacrificed 7 days after reimplantation. No evidence of necrosis or vascular insufficiency was identified histologically. The results indicate that canine larynges can be successfully reimplanted after 24 hours of preservation. Future studies will assess the application of this technique to laryngeal transplantation.

Electroglottography and laryngeal articulation in speech

Electroglottography (EGG) has been used for investigating the functioning of the vocal folds during vibration. EGG is related to the patterns of vocal fold vibration during phonation and characterizes the temporal patterns of each vibratory cycle. The purpose of this study was to investigate the dynamic changes in EGG waveforms during continuous speech. Aerodynamic signals, air pressure and airflow were evaluated simultaneously with EGG waveforms. Fundamental frequency (F0), open quotient (OQ) and baseline shift of the EGG during speech production were measured for three types of Korean consonants using EGG waveforms. The glottal airway resistance during speech production was measured using aerodynamic waveforms, and evaluated for the relationship with F0, OQ and baseline shift. The results indicated that the EGG waveforms seem to be significantly affected by the articulatory activities of the larynx, airflow and subglottic pressure, and may be a useful method to describe dynamic laryngeal articulatory activity during continuous speech.

The assessment of nasality with a nasometer and sound spectrography in patients with nasal polyposis

With the development of computerized acoustic analysis systems, an objective measure of nasal speech has become readily available by means of a simple, noninvasive technique. In this study, we assessed the nasality in patients with multiple nasal polyposis before and after endoscopic sinus surgery. With the nasometer, we measured nasalance, which reflects the ratio of acoustic energy output of nasal sounds from the nasal and oral cavities, and the slope score of the nasogram curve. The nasalance scores of nasal sentences and the slope scores of the nasogram curves for all nasal consonants were significantly lower in patients with nasal polyposis than in healthy subjects. After surgery, however, the nasalance and slope scores increased significantly to the normal range. On the sound spectrographic analysis, the frequencies of the first nasal formant decreased slightly and the sound intensity increased slightly for all nasal consonants after surgery. However, no significant change was noticed in the frequencies of the second nasal formant. In conclusion, nasometric and sound spectrographic analyses are considered to be useful tools for objectively assessing the extent of nasality in patients with nasal airway obstruction.

Phonatory characteristics of patients undergoing thyroidectomy without laryngeal nerve injury

Complications that arise after thyroid surgery may be associated with infection, hemorrhage, hormonal problems, and laryngeal nerve injury. Voice alteration after thyroidectomy is usually caused by recurrent or superior laryngeal nerve injury. This voice dysfunction may also be associated with laryngotracheal fixation with impairment of vertical movement or by temporary malfunction of the strap muscles after surgery. In this study, we evaluated the voice function phonetically before and after thyroidectomy in 54 patients, although function of the recurrent and superior laryngeal nerves was normal. During surgery, the superior and recurrent laryngeal nerves were identified and protected, and after surgery electromyographic testing of the cricothyroid muscle was performed. Typical voice symptoms after surgery were easy fatigue during phonation and difficulty with high pitch and singing voice. Acoustic analysis revealed that the phonation time and fundamental frequency were not changed after surgery, but the speaking fundamental frequency, range of speaking fundamental frequency, and vocal range were significantly diminished after surgery. These data allowed us to suggest that the cause of voice dysfunction is not seen in neural lesions, but in a disturbance of the extralaryngeal skeleton. These voice changes emphasize the importance of the extralaryngeal mechanism for pitch control.

Secretory phospholipase Pla2g2a confers resistance to intestinal tumorigenesis

Individuals inheriting the same mutation predisposing to cancer may show very different outcomes, ranging from early aggressive cancer to disease-free survival. Experimental mouse models can provide a powerful tool to identify factors in the environment and genetic background that account for such modifications. The Min mouse strain, in which the ApcMin mutation disrupts the mouse homologue of the human familial polyposis gene, develops intestinal neoplasms whose multiplicity is strongly affected by genetic background. We previously mapped a strong modifier locus, Mom1 (modifier of Min-1), to a 4-cM region on mouse chromosome 4 containing a candidate gene Pla2g2a encoding a secretory phospholipase. Here, we report that a cosmid transgene overexpressing Pla2g2a caused a reduction in tumour multiplicity and size, comparable to that conferred by a single copy of the resistance allele of Mom1. These results offer strong evidence that this secretory phospholipase can provide active tumour resistance. The association of Pla2g2a with Mom1 thus withstands a strong functional test and is likely to represent the successful identification of a polymorphic quantitative trait locus in mammals.

The role of strap muscles in phonation--in vivo canine laryngeal model

In spite of the presumed importance of the strap muscles on laryngeal valving and speech production, there is little research concerning the physiological role and the functional differences among the strap muscles. Generally, the strap muscles have been shown to cause a decrease in the fundamental frequency (F0) of phonation during contraction. In this study, an in vivo canine laryngeal model was used to show the effects of strap muscles on the laryngeal function by measuring the F0, subglottic pressure, vocal intensity, vocal fold length, cricothyroid distance, and vertical laryngeal movement. Results demonstrated that the contraction of sternohyoid and sternothyroid muscles corresponded to a rise in subglottic pressure, shortened cricothyroid distance, lengthened vocal fold, and raised F0 and vocal intensity. The thyrohyoid muscle corresponded to lowered subglottic pressure, widened cricothyroid distance, shortened vocal fold, and lowered F0 and vocal intensity. We postulate that the mechanism of altering F0 and other variables after stimulation of the strap muscles is due to the effects of laryngotracheal pulling, upward or downward, and laryngotracheal forward bending, by the external forces during strap muscle contraction.

Influence of dietary folic acid on the developmental toxicity of methanol and the frequency of chromosomal breakage in the CD-1 mouse

The proposed increased use of methanol (MeOH)-based fuels raises the concern for an increased risk for MeOH toxicity. MeOH, which is detoxified in part via a folate-dependent pathway, is known to be teratogenic in rodents. Previous observations have implicated maternal folate status as a critical modulator for the developmental toxicity of MeOH. The current study extends these findings, examining the effect of maternal dietary folate intake on fetal folate stores, as well as identifying a possible marker for the prediction of the developmental toxicity of MeOH. Virgin female CD-1 mice were assigned to diets containing either 400 (marginal) or 1200 (control) nmol folic acid (FA)/kg, and and 1% succinylsulfathiazole for 5 weeks prior to mating and throughout breeding and gestation. From gestation day (GD) 6 through 10 dams were given by gavage deionized, distilled water (dH2O) or MeOH at 2.5 g/kg body weight, twice daily. On GD 18, mice were weighed and killed and the liver, kidneys, and gravid uteri removed and weighed. Implantation sites, live and dead fetuses, and resorptions were counted; fetuses were weighed individually and examined for cleft palate and exencephaly. The marginal FA dietary treatment resulted in low maternal liver (50% reduction) and red cell folate (30% reduction) concentrations, as well as low fetal tissue folate concentrations (60 to 70% reduction) relative to the adequate FA dietary groups. Marginal FA treatment alone resulted in cleft palate in 13% of the litters; there were no litters affected with cleft palate in the adequate FA-control group. Marginal FA-MeOH treatment resulted in a further increase in the litters affected by cleft palate (72% of litters affected). The percent of litters affected by exencephaly was highest in the marginal FA-MeOH group. The frequency of micronuclei in maternal and fetal reticulocytes, a marker for chromosomal abnormalities, was not influenced by either the marginal FA diet or by MeOH treatment. These results show that marginal folate deficiency in pregnant dams significantly increases the teratogenicity of MeOH.

Comparison of the effects of the laryngeal mask airway and endotracheal intubation on vocal function

We have compared changes in vocal function produced after insertion of a laryngeal mask airway (LMA) with those produced by tracheal intubation in 20 patients. Using acoustic waveform analysis, we computed amplitude variability (AV), pitch variability (PV), harmonics-to-noise ratio (HNR) and additive noise level (ANL) before anaesthesia and at 1, 4, and 24 h after tracheal extubation. There were no significant changes in vocal function after extubation except for HNR ratio (P = 0.046) at 4 h in the LMA group. There were differences in all four variables at 1 h, 4 h, or both, after tracheal extubation compared with baseline in the tracheal tube group. In both groups, all variables were the same as baseline values 24 h after extubation. We observed significant differences in AV (4 h), PV and ANL (1, 4 h) values between the two groups. These observations suggest that the LMA causes less vocal change than tracheal intubation.

Sequence and chromosomal localization of two PET genes required for cytochrome c oxidase assembly in Saccharomyces cerevisiae

The nuclear genes PET117 and PET191 are required for the assembly of active cytochrome c oxidase in S. cerevisiae, yet their gene products are not subunits of the final assembled cytochrome c oxidase complex. Plasmids bearing PET117 or PET191 were isolated by their ability to complement the pet117-1 or pet191-1 mutations, respectively. By restriction mapping, subcloning, and deletion analysis of yeast DNA fragments that complement these mutations, the PET117 and PET191 genes were localized to smaller regions of DNA, which were then sequenced from both strands. The PET117 open reading frame is of 107 codons and the PET191 open reading frame is of 108 codons. Neither the PET191 nor PET117 DNA sequences have been reported previously, and the derived amino-acid sequences of the PET191 and PET117 open reading frames exhibit no significant primary amino-acid sequence similarity to other protein sequences available in the NBRF data base, or from translated Genbank sequences. By hybridization of PET117 or PET191 probes first to a chromosome blot and next to a library of physically mapped fragments of yeast genomic DNA, the map locations of the PET191 and PET117 genes were determined. PET117 is located on chromosome V near the HIS1 gene and PET191 is located on chromosome X near the CYC1 gene.

Characterization of Pseudomonas fluorescens carboxylesterase: cloning and expression of the esterase gene in Escherichia coli

The Pseudomonas fluorescens gene (estB) that encodes a novel esterase (esterase II) was cloned into Escherichia coli JM83. DNA sequencing found a single open reading frame of 654 nucleotides. The open reading frame was confirmed by N-terminal amino acid sequence analysis of the esterase protein. A potential Shine-Dalgarno sequence is followed by the coding sequence of the estB gene. The amino acid sequence deduced from the nucleotide sequence contains the consensus active site sequence, G-X-S-X-G, of serine esterases. The enzyme expressed in an E. coli clone was purified by ion-exchange chromatography and gel filtration. Homogeneity of the purified enzyme was confirmed using SDS-polyacrylamide gel electrophoresis. The native enzyme exists as a dimer consisting of two identical subunits, each with a molecular weight of 23,000. The results of the experiments for identifying substrate specificity and the inhibitor studies suggest that this enzyme is a carboxylesterase (EC 3.1.1.1) and a serine residue is present at the active site of the esterase, as in the esterases of animal tissues.

Early predictor of the efficacy of immunoprophylaxis against perinatal hepatitis B transmission: analysis of prophylaxis failure

To research early predictors of the efficacy of the ongoing mass immunoprophylaxis against perinatal hepatitis B virus (HBV) transmission in Taiwan and to analyse the possible causes of immunoprophylaxis failure, 52 hepatitis Be antigen (HBeAg)-positive carrier mothers were recruited for the study. Maternal blood samples were taken at the first and third trimesters and delivery. Umbilical blood was collected and venous blood samples were taken at 4, 7, 11 and 14 months of age. Serum hepatitis B surface antigen (HBsAg) and antibody titres, HBeAg titre and HBV-DNA concentration were analysed. All the umbilical cord blood samples were negative for HBsAg. Among the 52 vaccinated infants, four were poor responders (anti-HBs less than 10 mIU ml-1 before vaccine booster). Another five infants became HBsAg-positive by 4 months of age and remained carriers. All these five carrier mothers were HBV-DNA-positive and three of them had risk factors related to maternal-fetal haemorrhage during pregnancy or delivery. The remaining 43 infants showed protective anti-HBs level (greater than 10 mIU ml-1) by 4 months of age. Three mothers out of these 43 cases also had the same haemorrhage risk factors during pregnancy or delivery, but were HBV-DNA-negative. Therefore, the anti-HBs level at 4 months is a predictor of the success of immunoprophylaxis. It may be helpful to distinguish HBV-DNA-positive carrier mothers among HBeAg-positive ones, to avoid inducing more maternal-fetal haemorrhage in such cases during pregnancy or delivery. Otherwise, additional hepatitis B immune globulin may be indicated in such cases to raise the successful prevention rate.

Enhancement of accuracy in OTF measurement

A knife-edge scanning method was developed to enhance the accuracy in OTF measurement. A slit image formed by the lens under test was scanned by a knife-edge which was moved by a stepping motor. It was possible to increase the signal-to-noise ratio with averaging 4-32 data at each point through a scan. The standard deviation was decreased to under 0.25% in the MTF unit.

Effect of aperture modulation on the MTF of a binocular objective having off-axis aberrations

Aperture modulation effects have been investigated in a Korean binocular objective lens in isolation from the rest of the system. The off-axis aberrations are derived from the design data. The MTFs are measured for the same modulated aperture and compared by the same method, in the presence of off-axis aberrations, as the rotationally symmetric aberrations presented in the previous paper [Appl. Opt. 22, 1812 (1983)]. The MTF of the lens was found to be improved by proper aperture modulation.