Application of a barometer for assessment of oral functions: Donders space.

We developed a barometer applicable to a small space, to assess oral and pharyngeal functions. Negative oral pressure during rest and pressure changes during swallowing were measured in a space between the palate and tongue (STP). Twenty volunteers were asked to sit in a chair in a relaxed upright position. A sensor was placed on the posterior midline of hard palate. Recording commenced just before subjects closed their lips and continued. Subjects were asked to swallow saliva and keep the apposition. Finally, subjects were asked to open their mouth. Recordings were performed five times, and 5 s of continuous data in each phase was averaged. To verify the reliability of the system, the same procedure was accomplished with twin sensors. When the jaw and lips were closed, the pressure slightly decreased from atmospheric pressure (-0·17 ± 0·24-kPa). After swallowing, the pressure in STP showed more negative value (-0·50 ± 0·59-kPa). There is a significant difference between the values in open condition and after swallowing (P < 0·001) and between values after swallowing and final open condition (P < 0·05). Twin sensor showed almost the same trajectories of pressure changes for all the recordings. Obtained negative pressure might generate about 0·71-N of force and would be enough to keep the tongue in the palatal fossa at rest. The system detected large negative/positive pressure changes during swallowing. We conclude this system may be a tool to evaluate oral functions.

Mucormycosis in an immunocompetent patient: follow-up of 1 year after treatment.

Mucormycosis is a rare acute fatal fungal infection. It is typically observed in diabetic or immunocompromised patients but not in systemically healthy individuals. Here, we describe an unusual mucormycosis case in an immunocompetent patient who had clinical signs of a maxillary sinusitis and associated osteomyelitis at the first examination. He was treated by surgery and removal of the necrotic bone and amphotericin B medication. At 1-year follow-up he shows complete recovery.

Conformation changes of cuttlefish (Euprymna morsei) rhodopsin following photoconversion.

Cuttlefish (Euprymna morsei) rhodopsin solubilized in lauryl ester of sucrose and its photoproduct, acid metarhodopsin, were examined by small-angle X-ray scattering and chromatofocusing to investigate the conformation changes of visual pigment following photoconversion. From spectroscopic studies, it was found that more than 93% of Euprymna rhodopsin could be converted to meta form under the condition of red light irradiation at neutral pH. Since almost pure acid metarhodopsin solution was prepared without changing the specimen concentration, the small-angle X-ray scattering intensities of both pigment-detergent complexes were directly compared. The radius of gyration increased on going from rhodopsin to acid metarhodopsin by approximately 1.5%. There were also discernible changes in the secondary peak intensities. The distribution function, derived by the Fourier transformation of intensity data, showed a significant change around 55 A. The maximum linear dimension of the rhodopsin-detergent complex was about 95 A and hardly changed after illumination. Intensity at zero angle did not change after illumination, suggesting that the aggregation did not occur. The change of the intensity profile could be due to the conformational change of the pigment-detergent monomers. The pI value of rhodopsin determined by chromatofocusing was 5.32 and that of acid metarhodopsin was 5.06, indicating that a few carboxyl groups are newly dissociated. The shift of the protein mass and the charge redistribution were observed following photoconversion.

Amino acid sequence of the retinal binding site of squid visual pigment.

The retinylpeptides of visual pigments of two species of squid were identified in invertebrate visual pigments. Their primary structures were identical: H-Phe-Ala-Lys-Ala-Ser-Ala-Ile-His-Asn-pro-Hse(Met)-OH. The sequence was homologous to those of the corresponding region of other visual pigments, but the eighth amino acid, His, was found in squid visual pigments. In this experiment the retinylpeptides of eleven amino acid residues were isolated by monitoring the absorbance spectrum of the reduced retinal Schiff base without using radio-active [3H]retinal. This method is valid for the isolation and identification of retinylpeptides of other invertebrate visual pigments in which the chromophore is not exchangeable.

Formation of the two-dimensional hexagonal lattice of bacteriorhodopsin in reconstituted brown membrane.

The aggregation state of reconstituted bacteriorhodopsin molecules in the brown membrane has been investigated by X-ray diffraction and CD spectra. It has been confirmed that reconstituted bacteriorhodopsin molecules form the hexagonal lattice spontaneously whereas bacterioopsin molecules do not.

Volatile anesthetics cause conformational changes of bacteriorhodopsin in purple membrane.

We examined the effects of volatile anesthetics on the structure of the bacteriorhodopsin in the purple membrane by measurements of the absorption spectrum and the visible circular dichroism (CD) spectrum and assay of the retinal composition. As the concentrations of halothane, enflurane and methoxyflurane were increased, the absorption at 560 nm decreased but that at 480 nm increased with an isosbestic point around 510 nm. These anesthetic-induced spectroscopic changes were reversible. The CD spectrum showed the biphasic pattern with a positive and a negative band. As the concentration of halothane was increased from 4 mM to 8mM, the negative band reversibly diminished more drastically than the positive band, and at 8 mM of halothane the positive band shifted to around 480 nm. These results show that halothane disturbed the exciton coupling among bacteriorhodopsin molecules. The retinal isomer composition was analyzed using high performance liquid chromatography. The ratio of 13-cis- to all-trans-retinal was 47:53, 34:66 and 19:81 at control, 7.4 mM and 14.9 mM enflurane, respectively. After elimination of enflurane, the ratio returned to the control value. These findings indicate that volatile anesthetic directly affect a bacteriorhodopsin in the purple membrane and induce conformational changes in it.

4-Hydroxyretinal, a new visual pigment chromophore found in the bioluminescent squid, Watasenia scintillans.

The bioluminescent squid, Watasenia scintillans has three visual pigments. The major pigment, based on retinal (lambda max 484 nm), is distributed over the whole retina. Another pigment based on 3-dehydroretinal (lambda max approximately 500 nm) and the third pigment (lambda max approximately 470 nm) are localized in the specific area of the ventral retina just receiving the downwelling light. Visual pigment was extracted and purified from the dissected retina. The chromophores were then extracted and analyzed with HPLC, NMR, infrared and mass spectroscopy, being compared with the synthetic 4-hydroxyretinal. A new retinal derivative, 11-cis-4-hydroxyretinal, is identified as the chromophore of the third visual pigment of the squid.

A mechanistic account of the mirror effect for word frequency: a computational model of remember-know judgments in a continuous recognition paradigm.

A theoretical account of the mirror effect for word frequency and of dissociations in the pattern of responding Remember vs. Know (R vs. K) for low- and high-frequency words was tested both empirically and computationally by comparing predicted with observed data theory in 3 experiments. The SAC (Source of Activation Confusion) theory of memory makes the novel prediction of more K responses for high- than for low-frequency words, for both old and new items. Two experiments used a continuous presentation and judgment paradigm that presented words up to 10 times. The computer simulation closely modeled the pattern of results, fitting new Know and Remember patterns of responding at each level of experimental presentation and for both levels of word frequency for each participant. Experiment 3 required list discrimination after each R response (Group 1) or after an R or K response (Group 2). List accuracy was better following R responses. All experiments were modeled using the same parameter values.

Effect of sodium dodecyl sulfate on immuno-electrosyneresis between normal human erythrocyte membrane and sera of systemic lupus erythematosus patients.

An anti-membrane antibody was present in the sera of systemic lupus erythematosus patients in immunoelectrosyneresis with sodium dodecyl sulfate (SDS) solubilized erythrocyte membrane as antigen. The SDS bound to protein was detected by chromatography at 10(-3)M concentration under U.V. light, at 10(-5)M concentration by the distilled water spray method and at 10(-6)M concentration by using rosaniline hydrochloride colorimetry. SDS was removed from the membrane protein at a concentration of 10(-3)M by the first gel filtration of Sephadex G-25 column and at a concentration of 10(-6)M by rechromatography of the same column. More than 99% of SDS in the solubilized erythrocyte membrane was removed by gel filtration. The antigenicity was still positive in the refiltrated fractions of systemic lupus erythematosus patients. Therefore, all precipitates in the gels were antigen-antibody aggregates.

Vitamin B12 levels of cerebrospinal fluid in patients with a variety of neurological disorders.

The vitamin B12 levels of cerebrospinal fluid were assayed microbiologically (Lactobacillus leichmannii method) using samples from 44 patients with various neurological disorders, 4 patients with megaloblastic anemia and 34 controls. Twenty-seven controls that did not receive vitamin B12 showed a mean cerebrospinal fluid vitamin B12 level of 21.5 pg/ml (range: 0-60). No decrease in cerebrospinal fluid vitamin B12 level was seen in patients with subacute myelo-optico-neuropathy (SMON). High levels of cerebrospinal fluid vitamin B12 were observed only in the patients receiving long term administration of the vitamin. Intrathecal administration of vitamin B12 caused only a slight increase in serum vitamin B12 level after four hours. The existence of blood brain barrier for vitamin B12 was suggested.

Relation between maximum phonation time and exercise capacity in chronic heart failure patients.

BACKGROUND: Patients with chronic heart failure (CHF) commonly fatigue easily due to low peak oxygen uptake (peak VO(2)), an important index of exercise capacity. Maximum phonation time (MPT) is widely used to evaluate maximum vocal capabilities because it is non-invasive, quick, and inexpensive. AIM: The aim of this study was to determine the relation between MPT and exercise capacity, and MPT required to attain an exercise capacity of ≥5 metabolic equivalents (METs) in CHF outpatients. DESIGN: Cross-sectional study. SETTING: Outpatient cardiac rehabilitation unit. POPULATION: We enrolled 111 CHF outpatients (mean age 54.2±10.1 years). METHODS: Peak VO(2) was assessed during cardiopulmonary exercise testing (CPX) as the index of exercise capacity. After CPX, we divided the patients into two groups according to exercise capacity: ≥5 METs group (N.=68) and <5 METs group (N.=43). Measurements of MPT were taken in the seated position. All patients were asked to produce a sustained vowel /a:/ for as long as possible and were verbally encouraged during respiratory effort. RESULTS: After adjustment for patient clinical characteristics, MPT in the CHF patients was found to be significantly higher in the ≥5 METs group than in the <5 METs group (22.1±8.4 vs. 17.0±11.6 s, F=13.5, P<0.001). Receiver-operating characteristic curve analysis of exercise capacity of ≥5 METs extracted a cutoff value for MPT of 18.27 s, with a sensitivity of 0.76, 1-specificity of 0.33, and AUC value of 0.81 (95% CI: 0.70-0.87, P<0.001). CONCLUSION: There were differences in MPT in relation to an exercise capacity threshold of ≥5 METs in CHF outpatients. A MPT of 18.27 sec may be the best cutoff value to identify people with or without exercise capacity of ≥5 METs. CLINICAL REHABILITATION IMPACT: Measurement of MPT may be a useful method for estimating exercise capacity in CHF outpatients.