The dual functions of Tetrahymena citrate synthase are due to the polymorphism of its isoforms

Previous studies have shown that Tetrahymena citrate synthase and the Tetrahymena 14-nm filament protein are encoded by a single gene and translated from one species of mRNA, and that they are identical in terms of molecular weight, antigenicity, and some enzymatic properties. In this study, using two-dimensional gel electrophoresis, we demonstrated that the citrate synthase comprised pI 7.7 and 8.0 isoforms, while the 14-nm filament protein comprised three isoforms with isoelectric points of 7.7, 8.0, and 8.4. The amino acid sequences of the NH2-terminal portions of all isoforms were identical and the peptide maps with V8 protease were almost the same. In addition, when the citrate synthase activity of each isoform was measured after separation by non-urea isoelectric focusing without denaturing treatment, the pI 7.7 and/or pI 8.0 isoforms exhibited the citrate synthase activity, but the pI 8.4 isoform only found for the 14-nm filament protein did not possess this activity. These results suggest that the polymorphism of these isoforms is caused by some posttranslational modifications, and that it may have resulted in the different compartmentalization and functions of Tetrahymena citrate synthase and the 14-nm filament protein.

Idiopathic CD4+ T-lymphocytopenia with Bowen's disease

A 39-year-old man with Bowen's disease was troubled with multiple molluscum contagiosum over the trunk and lower extremities. Subsequently oral candidiasis was complicated. Laboratory examination revealed lymphocytopenia and a decrease in the CD4/CD8 ratio. His CD4+ T-lymphocyte count was only 187 cells/microl one time and 222 cells/microl another time. No evidence for human immunodeficiency virus (HIV) infection was found. He had no family history of immunodeficiencies.

Purification and characterization of the human interleukin-18 receptor

Interleukin (IL)-18 was identified as a molecule that induces IFN-gamma production and enhances NK cell cytotoxicity. In this paper, we report upon the purification and characterization of human IL-18 receptor (hIL-18R). We selected the Hodgkin's disease cell line, L428, as the most strongly hIL-18R-expressing cell line based on the results of binding assays. This binding was inhibited by IL-18 but not by IL-1beta. The dissociation constant (Kd) of 125I-IL-18 binding to L428 cells was about 18.5 nM, with 18,000 binding sites/cell. After immunizing mice with L428 cells and cloning, a single monoclonal antibody (mAb) against hIL-18R was obtained (mAb 117-10C). Sequentially, hIL-18R was purified from 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid (CHAPS)-extracted L428 cells by wheat germ lectin-Sepharose 4B chromatography and mAb 117-10C-Sepharose chromatography. The internal amino acid sequences of hIL-18R all matched those of human IL-1 receptor-related protein (IL-1Rrp), the ligand of which was unknown to date. When expressed in COS-1 cells, the cDNA of IL-1Rrp conferred IL-18 binding properties on the cells and the capacity for signal transduction. From these results, we conclude that a functional IL-18 receptor component is IL-1Rrp.

Memory of extracellular adenosine A2A purinergic receptor-mediated signaling in murine T cells

Accumulation of extracellular and intracellular adenosine (Ado) under hypoxic conditions or in the absence of adenosine deaminase results in lymphocyte depletion and in severe combined immunodeficiency, which are currently explained by direct intracellular lymphotoxicity of Ado metabolites. In support of the alternative, "signaling" mechanism, we show that extracellular Ado (extAdo) suppresses all tested T cell receptor (TCR)-triggered effector functions of T lymphocytes including the TCR-triggered FasL mRNA up-regulation in cytotoxic T lymphocytes. Strong evidence against the intracellular lymphotoxicity of Ado (and in support of the signaling model) is provided by abrogation of TCR-triggered growth inhibition in Ado-exposed T cells. The brief exposure to Ado was sufficient to observe inhibition of TCR-triggered effector functions. The "memory" of T cells to exposure to extAdo is best explained by sustained increases in cAMP. Selective agonist (CGS21680) and antagonist (ZM241385) of A2A adenosine receptor were used in functional assays and cDNA probes for different sybtypes of adenosine receptors were used in Northern blot studies. A2A receptors are identified as the predominantly expressed subtype of Gs-coupled Ado receptors in T cells. The demonstration of cross-talk between the A2A receptors and TCR in both directions support the possible role of A2A receptors in mechanisms of extAdo-mediated immunosuppression in vivo under adenosine deaminase deficiency and hypoxic conditions in, e.g., solid tumors.

A comparative study of 2',3'-cyclic-nucleotide 3'-phosphodiesterase in vertebrates: cDNA cloning and amino acid sequences for chicken and bullfrog enzymes

In mammalian brain, two 2',3'-cyclic-nucleotide 3'-phosphodiesterase (EC 3.1.4.37) isoforms, CNP1 and CNP2, are translated, respectively, from the two mRNAs, which have been transcribed and processed by alternative use of the two transcription start points and by differential splicing. In the present study, the cDNAs encoding chicken CNP2 and bullfrog CNP1, respectively, were isolated, and the amino acid sequences of chicken CNP2 and bullfrog CNP1 were deduced. Western blot analysis showed that chicken brain contains a major CNP2-type protein together with a minor unidentified isoform, and bullfrog brain contains only a CNP1-type protein. All available amino acid sequences of vertebrate 2',3'-cyclic-nucleotide 3'-phosphodiesterases were aligned and compared. Three conserved motif sequences were noted: (a) an ATP-binding site near the amino terminus, (b) an isoprenylation site at the carboxyl terminus, and (c) a probable catalytic site resembling the active site of beta-ketoacyl synthase (EC 2.3.1.41). The second and the third motifs are conserved also in goldfish RICH (regeneration-induced 2',3'-cyclic-nucleotide 3'-phosphodiesterase homologue), which has been shown recently to have 2',3'-cyclic-nucleotide 3'-phosphodiesterase activity. The third motif (probably catalytic site) was assigned for the first time in the present report.

Mechanics of single kinesin molecules measured by optical trapping nanometry

We have analyzed the mechanics of individual kinesin molecules by optical trapping nanometry. A kinesin molecule was adsorbed onto a latex bead, which was captured by an optical trap and brought into contact with an axoneme that was bound to a glass surface. The displacement of kinesin during force generation was determined by measuring the position of the beads with nanometer accuracy. As the displacement of kinesin was attenuated because of the compliance of the kinesin-to-bead and kinesin-to-microtubule linkages, the compliance was monitored during force generation and was used to correct the displacement of kinesin. Thus the velocity and the unitary steps could be obtained accurately over a wide force range. The force-velocity curves were linear from 0 to a maximum force at 10 microM and 1 mM ATP, and the maximum force was approximately 7 pN, which is larger by approximately 30% than values previously reported. Kinesin exhibited forward and occasionally backward stepwise displacements with a size of approximately 8 nm. The histograms of step dwell time show a monotonic decrease with time. Model calculations indicate that each kinesin head steps by 16-nm, whereas kinesin molecule steps by 8-nm.

Real-time measurement of nitric oxide production in rat brain by the combination of luminol-H2O2 chemiluminescence and microdialysis

A chemiluminescence method of detecting nitric oxide (NO) in combination with a microdialysis technique was employed for the real-time measurement of NO production in living rat brain. This method based on the luminol-H2O2 system has a detection limit of 1 nM, and is the most sensitive method currently available for measuring NO. We applied this new technique to rat cerebellum to record the increase of chemiluminescence intensity arising from NO production after the injection of N-methyl-D-aspartate or kainic acid around the microdialysis probe. This highly sensitive method should be useful for the direct clarification of the functions of NO in the central nervous system.

Adenovirus-mediated transduction with human glial cell line-derived neurotrophic factor gene prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopamine depletion in striatum of mouse brain

As a novel trial of neuroprotective therapy of neurodegenerative diseases, we have constructed a recombinant adenovirus vector (rAdv) bearing a neurotrophic factor gene to deliver the factor to rescue neurons in vivo. In the present study, human glial cell line-derived neurotrophic factor (hGDNF) was chosen to examine the applicability of our strategy to a mouse model of Parkinson's disease. During the construction of the rAdv, we found that the strong constitutive hGDNF expression unit somehow inhibited the appearance of the rAdv. Therefore we adopted a self-contained tetracycline-regulated expression system to acquire an rAdv expressing hGDNF. By analyzing the condition medium of SH-SY5Y cells infected with our constructed virus vector, we confirmed that biologically active GDNF was successfully expressed in vitro. For an animal study, we delivered this virus vector directly to the C57 black mouse brain and then exposed the animal to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to injure the nigrostriatal dopaminergic neurons. One week after the MPTP exposure, the neuroprotective effect of the virus vector was estimated by measurement of the dopamine content in the striatum of the mouse brain. The mice that had received our constructed virus had significantly higher dopamine levels in their striatum, demonstrating that our rAdv expressing hGDNF has therapeutic potential to protect the nigrostriatal dopaminergic neurons in vivo.

Leukocyte function-associated antigen-1-dependent lysis of Fas+ (CD95+/Apo-1+) innocent bystanders by antigen-specific CD8+ CTL

Exquisite specificity toward Ag-bearing cells (cognate targets) is one of the most important properties of CD8+ CTL-mediated cytotoxicity. Using highly Ag-specific CD8+ CTL lines and clones, which spare noncognate, Ag-free targets, we found that in the presence of Ag-bearing targets the CTL acquire the ability to lyse noncognate target cells (bystanders). It is shown that the unexpectedly rapid and efficient lysis of bystanders by Ag-activated CTL is mediated by a Fas ligand (FasL)/Fas-based mechanism and does not depend on perforin. The CTL lysed Fas-expressing bystanders, but spared the Fas-negative or anti-Fas mAb-resistant bystander cells. Accordingly, the FasL-deficient gld/gld CTL did not kill bystanders, while perforin-deficient CTL did. Unlike anti-Fas mAb-induced cell death, the lysis of bystanders was not only FasL/Fas dependent but also required adhesion molecule LFA-1 on the surface of the activated CTL. Lysis of bystanders is viewed as acceptable "collateral" damage, but the persistent presence of activated CTL could result in immunopathologies involving functional Fas-expressing tissues.

Leukocyte function-associated antigen-1-dependent lysis of Fas+ (CD95+/Apo-1+) innocent bystanders by antigen-specific CD8+ CTL

Exquisite specificity toward Ag-bearing cells (cognate targets) is one of the most important properties of CD8+ CTL-mediated cytotoxicity. Using highly Ag-specific CD8+ CTL lines and clones, which spare noncognate, Ag-free targets, we found that in the presence of Ag-bearing targets the CTL acquire the ability to lyse noncognate target cells (bystanders). It is shown that the unexpectedly rapid and efficient lysis of bystanders by Ag-activated CTL is mediated by a Fas ligand (FasL)/Fas-based mechanism and does not depend on perforin. The CTL lysed Fas-expressing bystanders, but spared the Fas-negative or anti-Fas mAb-resistant bystander cells. Accordingly, the FasL-deficient gld/gld CTL did not kill bystanders, while perforin-deficient CTL did. Unlike anti-Fas mAb-induced cell death, the lysis of bystanders was not only FasL/Fas dependent but also required adhesion molecule LFA-1 on the surface of the activated CTL. Lysis of bystanders is viewed as acceptable "collateral" damage, but the persistent presence of activated CTL could result in immunopathologies involving functional Fas-expressing tissues.

[Cortical status marmoratus in a patient with a sequela of postnatal anoxic encephalopathy]

Status marmoratus (ST) of the basal ganglia and thalamus has been observed in cases of perinatal hypoxic ischemic encephalopathy and rarely of postnatal encephalopathy. In occasional cases, the cerebral cortex is also involved. Here, we reported a 22-year-old male with a sequela of postnatal anoxic encephalopathy. He had been bedridden with severe mental retardation since he suffered anoxic encephalopathy at 3 months of age. ST was found in the cerebral cortex as well as basal ganglia and thalamus. In addition to ST, the cerebral cortex and white matter were remarkably devastated. We also performed a preliminary immunohistochemical study to investigate the process of ST formation, using antibodies against glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and synaptophysin. MBP-positive abnormal myelinated fibers were identified in the ST areas, which were not colocalized with GFAP-immunopositivity. Synaptophysin was positive in the areas of ST, which were not stained with Holzer method. These results suggest that the myelination in the early infancy damage of basal ganglia and cerebral cortex could be implicated in the formation of ST.

Caspase-3-mediated cleavage of protein kinase C theta in induction of apoptosis

Protein kinase C theta (PKCtheta) is a member of the novel or nPKC family. A functional role for PKCtheta is unknown. The present studies demonstrate that PKCtheta is cleaved in the third variable region (V3) in apoptosis induced by diverse agents. PKCtheta cleavage is blocked in cells that overexpress the anti-apoptotic Bcl-xL or the baculovirus p35 protein. PKCtheta is cleaved by Caspase-3 and by apoptotic cell lysates at a DEVD354/K site. We also show that overexpression of the cleaved kinase-active PKCtheta fragment, but not full-length PKCtheta or a kinase-inactive fragment, results in induction of sub-G1 phase DNA, nuclear fragmentation, and lethality. These findings indicate that proteolytic cleavage of PKCtheta by Caspase-3 induces events characteristic of apoptosis.

Temporal Phase Affects Spatial Binding in Depth Perception

The temporal linking of spatial information is essential for coherent space perception. We investigated the effect of the temporal phase of flickering ‘inducers’ in depth perception. Stereo half-images were generated on the left and right halves of a large-screen video monitor and viewed through a mirror stereoscope. The half-images portrayed a solid-black vertically oriented bar seen against a white background. Two brackets immediately flanking this bar could be placed in crossed or uncrossed disparity relative to the bar. A pair of thin white ‘bridging lines’ could appear on the black bar, always at zero disparity. Brackets and bridging lines could be flickered either in-phase or out-of-phase. Observers judged whether the brackets appeared in front of or behind the black bar, with disparity varied over trials according to a method of constant stimuli.

We found that when bridging lines were absent, the depth location of the brackets was predictably dependent on disparity sign, with a small bias for “behind” judgements owing to occlusion. When bridging lines and brackets flashed in temporal phase, depth judgements were markedly biased toward “in front”; when the bridging lines and brackets flashed out of phase, this bias was much reduced. This biasing effect also depended on the spatial offset of lines and brackets. We conclude that depth perception is strongly influenced by the temporal phase of the spatial information.

[Retrograde radical cystectomy. Advantages of our "vesico-rectal tunnel" method]

BACKGROUND

The facilitation of dissecting the vesical pedicles and undisturbed preservation of the membranous urethra were investigated during radical cystectomy using the retrograde technique.

METHODS

First, just as with radical prostatectomy, the prostate and the rectum were separated by blunt digital dissection. After the deep dorsal vein complex and the urethra were cut, the bladder and the rectum were also separated in a retrograde manner towards the Denonvillier's fascia. Then the peritoneum was opened and its lowest part was incised above the cul-de-sac. A tunnel was made beginning at the cut-end of the urethra to the cul-de-sac. Consequently, the bladder was lifted up by hand inserted this "vesico-rectal tunnel" and the bilateral remaining lateral pedicles were ligated and transsected without difficulty.

RESULTS

Fourteen patients underwent radical cystectomy using this technique. Among them, the average operating time and blood loss in 4 patients received retrograde radical cystectomy accompanied with ileal conduit were 5 hours 15 minutes and 1606 ml, respectively. These in 9 patients received retrograde radical cystectomy followed by bowel orthotopic urinary reservoir were 7 hours and 6 minutes and 1086 ml, respectively. Another patient received ureterocutaneoustomy.

CONCLUSION

Creating a "vesico-rectal tunnel" during radical cystectomy primarily by the retrograde extraperitoneal technique can afford to preserve the urethral sphincter and to ligate the pedicles easily. This method is fundamentally familiar to us because retrograde radical prostatectomy is now widely adopted and it may help to reduce the operating time even when there is a shortage of manpower.

Effect of selenium on human phospholipid hydroperoxide glutathione peroxidase expression and host cell susceptibility to lipid hydroperoxide-mediated injury

We recently isolated stable transfectants expressing human phospholipid hydroperoxide glutathione peroxidase (PHGPx) from the cells of guinea pig cell line 104C1 (Biochem. Biophys. Res. Commun. 219, 486-491, 1996). Among them, one transfectant, designated 104C1/O4C, expressed high glutathione peroxidase activity toward dilinoleoyl phosphatidylcholine hydroperoxide (PCOOH); and another one, 104C1/O2D, moderate activity. In the present study, we investigated the effect of selenium on the PHGPx activity and on the lipid hydroperoxide-mediated cell injury in the transfectants to clarify further the action of PHGPx in preventing oxidative injury of the cells. When transfectant 104C1/O2D cells were cultured in the medium added with 250 nM selenium, glutathione peroxidase activity toward PCOOH increased 8-fold. Western blot analysis also revealed an increase in the amount of protein immunoreactive against anti-rat PHGPx antibody in this transfectant. Lipid hydroperoxide-mediated cell injury to the transfectant 104C1/O2D was significantly suppressed in accordance with the increase in the enzyme activity when the cells were cultured in the medium added with selenium. On the contrary, neither glutathione peroxidase activity toward PCOOH nor susceptibility to the injury was affected by selenium addition to the medium of the parental 104C1 cells, which have no selenium-dependent glutathione peroxidase. These results clearly support our previous conclusion that expression of PHGPx is responsible for the protection of host cells from lipid hydroperoxide-mediated injury.

[Detection of Chlamydia trachomatis from urine sediment by PCR diagnostic reagent kit]

Chlamydia trachomatis detection by both swab CHLAMYDIAZYME and urine sediment AMPLICOR were performed on 61 males and 54 females who were suspected to have C. trachomatis genital infection (CTGI). Positive agreement between swab CHLAMYDIAZYME and urine sediment AMPLICOR was good, 96.9% in males and 96.6% in females. Negative agreement was 100% in males and 84.0% in females. "Swab CHLAMYDIAZYME positive-Urine sediment AMPLICOR negative specimen" were not obtained. "Swab CHLAMYDIAZYME negative-urine sediment AMPLICOR positive" resulted in four females who were finally diagnosed to have CTGI by repeated specimens on CHLAMYDIAZYME. Positive result by AMPLICOR was obtained on un-spun urine specimen that was in agreement with the laboratory result that the sensitivity of AMPLICOR reaches one thousand fold of CHLAMYDIAZYME. Detection on every separately collected urine specimen of one urination showed AMPLICOR positive all through the last cup specimen in both male and female. Those results seem to certify the reliability of C. trachomatis detection by urine sediment AMPLICOR. False negative by interference substance in urine and false positive by contamination were not experienced. On asymptomatic young male and female, positive rates of urine sediment AMPLICOR were 7.5% in male and 12.1% in female which are far more than the positive rate obtained by CHLAMYDIAZYME. Non invasive C. trachomatis detection method applicable to asymptomatic female is needed for control of CTGI. C. trachomatis detection could be facilitated by non invasive urine sediment AMPLICOR.

Diabetic lipemia with maturity-onset diabetes of the young

A 19-year-old woman with diabetic lipemia and maturity-onset diabetes of the young (MODY) is reported. Though her insulin secretory activity was preserved, she fell into mild diabetic ketoacidosis (DKA) and showed type V hyperlipidemia. Post-heparin plasma activity of lipoprotein lipase (LPL) was decreased even 10 days after initiating insulin injection but not deficient. The abnormalities in lipid metabolism were improved by long-term insulin treatment. Though the contribution of the genetic background to the lipid abnormalities is not clear, the characteristics of MODY in this patient including insulin secretory capacity under stress conditions such as DKA might play a role in the development of diabetic lipemia.

Aprotinin inhibits plasmin-induced platelet activation during cardiopulmonary bypass

BACKGROUND

In the past few years, aprotinin has been used in cardiac surgery with impressive results of reducing blood loss, but several adverse effects of aprotinin also have been reported. One of the most likely mechanisms is the inhibition of plasmin by aprotinin, although this indirect effect has not been reproduced in all experimental studies.

METHODS AND RESULTS

We evaluated the platelet function and fibrinolytic activity during human cardiac surgery, with or without aprotinin. During cardiopulmonary bypass (CPB) in humans without aprotinin (n=16), decrease of platelet aggregation induced by thrombin, increase of alpha-granule secretion of platelet and microparticle formation, and increase of plasmin/alpha2-antiplasmin complex (PIC) were observed. In contrast, low-dose aprotinin (1.0 x 10(6) KIU), which was administered only into the priming fluid of extracorporeal circuits (n=10), maintained platelet aggregation induced by thrombin and reduced alpha-granule secretion and microparticle formation of platelets during CPB. In vitro, plasmin (0.8 CU/mL) released alpha-granules of washed platelets, and this activation was completely inhibited by aprotinin (10 KIU/mL).

CONCLUSIONS

Aprotinin has indirect effects to inhibit platelet activation, and this may partly explain the reduction of blood loss during cardiac surgery. To prevent the adverse effects, a single and minimal use of aprotinin is important. The results of in vivo and in vitro studies suggest that platelet preservation was demonstrated by the lower concentration of aprotinin (1.0 x 10(6) KIU per patient or 10 KIU/mL) compared with the concentration that inhibits plasma fibrinolysis.

Cortical processing mechanism for vocalization with auditory verbal feedback

To investigate the relationship between motor and sensory speech center, cortical activity was examined using PET while normal subjects perceived their own voice which sounded different to the articulated one. The results showed significant activation in the superior temporal gyri with absence of activity in the supplementary motor area (SMA). In a previous study we found significant activation in SMA with no activity in the superior temporal gyrus when normal subjects simply vocalized. Thus, two different cortical pathways for vocalization were delineated: programmed pathway in SMA, and pathway with auditory verbal feedback. The former is thought to be the mature system in the adult, and the latter may be related to speech acquisition.

The role of the temporal coding system in the auditory cortex on speech recognition

To elucidate the temporal coding system for speech recognition, we synthesized stimulation sounds which do not contain formant information but do contain temporal information by transforming original sound wave to click sequences. Using this stimulation sound, we performed a recognition test and used PET to examine the cortical activities in normal subjects listening to this sound. The results of the recognition test showed a good perception of the sounds made from sequential speech. The PET study demonstrated significant activation of the superior temporal gyri while listening to the stimulation speech sounds. Our results imply that these stimulation sounds were processed semantically in the auditory cortices. The temporal processing system is thought to make an important contribution to speech recognition.

Use of hydroxyapatite for reconstruction after surgical removal of intraosseous hemangioma in the zygomatic bone

Two rare cases of intraosseous hemangiomas in the zygomatic bone that were repaired after surgical removal of the tumor with hydroxyapatite implants are reported. Case 1 is a 42-year-old woman, and case 2 is a 46-year-old man. They complained of swelling in the right cheek. An intraosseous tumor in the right zygomatic bone was observed in both patients. The tumor was resected, and hydroxyapatite was employed to repair the defect caused by removal. After 4 years since the operation in case 1 and 8 months in case 2, the patients show satisfactory cosmetic appearance. Hydroxyapatite implant was useful for reconstruction of the defect after surgical removal of hemangiomas in the zygomatic bone.

Characterization of a second lysine decarboxylase isolated from Escherichia coli

We report here on the existence of a new gene for lysine decarboxylase in Escherichia coli K-12. The hybridization experiments with a cadA probe at low stringency showed that the homologous region of cadA was located in lambda Kohara phage clone 6F5 at 4.7 min on the E. coli chromosome. We cloned the 5.0-kb HindIII fragment of this phage clone and sequenced the homologous region of cadA. This region contained a 2,139-nucleotide open reading frame encoding a 713-amino-acid protein with a calculated molecular weight of 80,589. Overexpression of the protein and determination of its N-terminal amino acid sequence defined the translational start site of this gene. The deduced amino acid sequence showed 69.4% identity to that of lysine decarboxylase encoded by cadA at 93.7 min on the E. coli chromosome. In addition, the level of lysine decarboxylase activity increased in strains carrying multiple copies of the gene. Therefore, the gene encoding this lysine decarboxylase was designated Idc. Analysis of the lysine decarboxylase activity of strains containing cadA, ldc, or cadA ldc mutations indicated that ldc was weakly expressed under various conditions but is a functional gene in E. coli.

Vocal fold atrophy: quantitative glottic measurement and vocal function

Videostroboscopic glottic measurements and vocal function were evaluated in 41 vocal fold atrophy patients with bowed vocal folds. The amount of bowing in the resting position and the glottal gap area and vibratory amplitude during phonation were measured from digitized videostroboscopic images. Vibratory amplitude was not decreased on atrophic vocal folds. With the same amount of total bowing, the glottal gap area for bilateral atrophy was smaller than for unilateral atrophy. These results suggest that vocal fold atrophy is not disadvantageous to thyroplasty type I, and that bilateral procedures may produce a better outcome than a unilateral procedure in the treatment of bilateral atrophy. Acoustic, aerodynamic, and perceptual parameters of vocal function were measured. The acoustic high-frequency power ratio and the H-index correlated with the glottal gap area. The mean flow rate correlated with the amount of bowing. The degree of dysphonia was related to the size of the glottal gap and bowing.