Effects of raised-intensity phonation on inflammatory mediator gene expression in normal rabbit vocal fold

OBJECTIVE

To investigate the hypothesis that a transient episode of raised-intensity phonation causes a significant increase in vocal fold inflammatory messenger RNA (mRNA) expression in vivo.

STUDY DESIGN

Prospective animal study.

SETTING

Laboratory.

SUBJECTS AND METHODS

Ten New Zealand White breeder rabbits received 30 minutes of experimentally induced modal or raised-intensity phonation, followed by a 30-minute recovery period. A separate group of five rabbits served as sham controls. Real-time polymerase chain reaction was performed to investigate the mRNA expression of interleukin 1beta (IL-1beta), transforming growth factor beta-1 (TGFbeta1), and cyclooxygenase-2 (COX-2). Separate one-way analysis of variance (ANOVA) tests were used to investigate differences in gene expression across groups, with an appropriate alpha correction of 0.016 to control for type I error. Significant main effects were further examined using Fisher's least significant difference.

RESULTS

ANOVA revealed that there were differences for IL-1beta, TGFbeta1, and COX-2 between sham control, modal phonation, and raised-intensity phonation (P 0.0001). Pairwise comparisons revealed that the expression of IL-1beta, COX-2, and TGFbeta1 increased significantly during raised-intensity phonation, compared to modal phonation and sham control (P 0.0001).

CONCLUSION

Results provided support for the hypothesis that a transient episode of raised-intensity phonation causes a significant increase in vocal fold inflammatory mRNA expression. Future studies will investigate the signal transduction pathways and mechanisms regulating the vocal fold inflammatory response. The long-term goal of these studies is to advance understanding of the molecular and cellular events underlying phonation-related tissue alterations.

Uranium stabilization of c28: a tetravalent fullerene

Laser vaporization experiments with graphite in a supersonic cluster beam apparatus indicate that the smallest fullerene to form in substantial abundance is C(28). Although ab initio quantum chemical calculations predict that this cluster will favor a tetrahedral cage structure, it is electronically open shell. Further calculations reveal that C(28) in this structure should behave as a sort of hollow superatom with an effective valence of 4. This tetravalence should be exhibited toward chemical bonding both on the outside and on the inside of the cage. Thus, stable closed-shell derivatives of C(28) with large highest occupied molecular orbital-lowest unoccupied molecular orbital gaps should be attainable either by reacting at the four tetrahedral vertices on the outside of the C(28) cage to make, for example, C(28)H(4), or by trapping a tetravalent atom inside the cage to make endothedral fullerenes such as Ti@C(28). An example of this second, inside route to C(28) stabilization is reported here: the laser and carbon-arc production of U@C(28).

In situ tissue engineering of canine skull with guided bone regeneration

CONCLUSION

Calcium alginate (CA) membrane prevents excessive fibrous tissue intrusion and/or dislocation of a bone scaffold. However, CA membrane did not always accelerate cranial bone regeneration.

OBJECTIVE

We previously reported skull regeneration using a bone substitute material (BSM), which consisted of collagen-coated beta-tricalcium phosphate and autologous bone fragments, and bone marrow-derived stromal cells (BSCs). However, excessive fibrous tissue intrusion or dislocation of the BSM occasionally interrupted bone regeneration. To avoid such problems, we examined CA membrane, which is useful for guided bone regeneration (GBR), to investigate whether this material maintains the bone regenerative space.

MATERIALS AND METHODS

Bone defects (2x2 cm) were created in the skulls of 12 adult beagle dogs using the same clinical procedure. Four experimental models were tested with or without BSM plus BSCs or CA membrane. In group I, the original free bone flap was replaced at the defect. In group II, after replacing the bone flap, the defect was covered with CA membrane. In group III, BSM plus BSCs were used as a gap filler. In group IV, BSM plus BSCs and CA membrane were applied. Histological examinations were performed 3 and 6 months after the operation.

RESULTS

In groups I and II, bone regeneration was not observed but fibrous tissue intrusion was prevented in group II. Bone neogenesis was more observed in group III than in group IV at 3 months (p<0.05). At 6 months, the regenerated areas were larger than those observed at 3 months, but the differences between groups III and IV were not statistically significant.

Age-associated changes in the expression and deposition of vocal fold collagen and hyaluronan

OBJECTIVES

We investigated age-associated changes in the expression and deposition of collagen and hyaluronan (hyaluronic acid; HA) in aged vocal folds.

METHODS

Thirty Sprague-Dawley rats were involved in this study. For gene expression analyses, 15 animals were divided into 3 age groups of young (2 month), adult (9 month), and elderly (18 month) rats. Real-time polymerase chain reaction testing was used to quantify the messenger RNA expression of procollagen types I and III, matrix metalloproteinases 2 and 9, and HA synthases 1, 2, and 3. The remaining 15 animals were divided into 3 similar age groups and underwent histologic analyses designed to investigate age-associated changes in the deposition of collagen and HA.

RESULTS

The results revealed down-regulated expression of procollagen types I and III, matrix metalloproteinases 2 and 9, and HA synthases 1, 2, and 3 in adult and elderly vocal folds, compared to young vocal folds. Histologically, staining of collagen was dense in the vocal folds of adult and elderly rats, and HA was less dense in the vocal folds of adult and elderly rats than in young rats.

CONCLUSIONS

A slowdown in the expression of procollagens and matrix metalloproteinases was associated with dense collagen in aged vocal folds, as observed in elderly humans. A similar decrease in the expression of genes that code for HA synthase was consistent with a low density of extracellular matrix HA in the vocal folds of elderly rats.

Identification of independent APP locus duplication in Japanese patients with early-onset Alzheimer disease

BACKGROUND

The occurrence of duplications of the amyloid precursor protein gene (APP) has been described in European families with early-onset familial Alzheimer disease (EO-FAD) and cerebral amyloid angiopathy. However, the contribution of APP duplication to the development of AD in other ethnic populations remains undetermined.

METHODS

The occurrence of APP duplication in probands from 25 families with FAD and 11 sporadic EO-AD cases in the Japanese population was examined by quantitative PCR and microarray-based comparative genomic hybridisation analyses. APP expression level was determined by real-time quantitative reverse-transcription (RT) PCR analysis using mRNA extracted from the peripheral blood of the patients.

RESULTS

We identified APP locus duplications in two unrelated EO-FAD families. The duplicated genomic regions in two patients of these families differed from each other. No APP duplication was found in the late-onset FAD families or sporadic EO-AD patients. The patients with APP duplication developed insidious memory disturbance in their fifties without intracerebral haemorrhage and epilepsy. Quantitative RT-PCR analysis showed the increased APP mRNA expression levels in these patients compared with those in age- and sex-matched controls.

CONCLUSIONS

Our results suggest that APP duplication should be considered in patients with EO-FAD in various ethnic groups, and that increased APP mRNA expression level owing to APP duplication contributes to AD development.

Regeneration of aged rat vocal folds using hepatocyte growth factor therapy

OBJECTIVES/HYPOTHESIS

We investigated acute changes in extracellular matrix gene expression and histologic changes in the deposition of collagen and hyaluronan (HA) from hepatocyte growth factor (HGF) treatment of the aged rat vocal fold. We hypothesized that: 1) HGF induces matrix metalloproteinase gene expression, which might contribute to the downregulation of collagen; and 2) HGF induces hyaluronan synthase (HAS) gene expression, which might play a role in the upregulation of extracellular matrix HA.

STUDY DESIGN

Prospective animal study.

METHODS

Fifteen, 18-month-old, Sprague-Dawley rats were involved in this study. For gene expression analyses, 10 rats were divided into two groups and received serial injections of sham (saline) or HGF (2 ng/microL) and sacrificed 2 weeks after the initial injection to investigate acute changes in extracellular matrix gene expression. A separate group of five animals received the above treatment and were sacrificed 4 weeks after the initial injection to investigate histologic changes in the deposition of collagen and HA.

RESULTS

Real-time polymerase chain reaction revealed significantly upregulated matrix metalloproteinase(MMP)-2, -9, and HAS-3 messenger RNA (mRNA) expression and significantly downregulated procollagen type I mRNA expression in the HGF-treatment group, compared to the sham-treatment group. Histologic staining revealed significantly reduced collagen deposition and increased deposition of HA in the HGF-treated vocal fold, compared to the sham-treated vocal fold.

CONCLUSIONS

HGF induced the upregulation of MMP-2, -9, and HAS-3, and downregulated the expression of procollagen type I. Histologically, aged vocal folds treated with HGF revealed decreased collagen deposition, and increased deposition of HA, compared to sham-treated vocal folds.

Characterization of raised phonation in an evoked rabbit phonation model

OBJECTIVES/HYPOTHESIS

Our laboratory has developed an in vivo rabbit model to investigate the effects of phonation on expression and turnover of the vocal fold extracellular matrix. As a logical outgrowth of this research to include phonotrauma in the present study, we investigated the hypothesis that an increase in airflow rate delivered to the glottis produces a change in glottal configuration and an increase in mean phonation intensity.

STUDY DESIGN

Prospective animal study.

METHODS

Six New Zealand white breeder rabbits weighing 3 to 5 kg were used in this study. A rigid endoscope and camera were used to document glottal configuration. Acoustic signals of modal and raised phonation were recorded and digitized. Two separate one-way repeated measures analysis of variance (ANOVA) tests were used to investigate within subject differences in phonation intensity and fundamental frequency between modal and raised phonation.

RESULTS

Phonation intensity was 54.19 dB SPL (6.21 standard deviations [SD]) during modal phonation, and 60.31 dB SPL (5.68 SD) during raised phonation. Endoscopic images revealed a convergent glottis, with greater separation of the vocal folds during raised phonation. Results of ANOVA revealed a significant within subjects effect for phonation intensity (P = .011). Pairwise comparisons revealed that phonation intensity increased significantly during raised phonation, compared to modal phonation (P = .008). No differences in mean fundamental frequency were observed between phonation conditions.

CONCLUSIONS

Improved understanding of factors that control phonation output in the in vivo rabbit model will result in improved capabilities to match phonation dose across animals and provide immediate direction to future biochemical studies.

[Surgical treatment for infective endocarditis]

OBJECTIVE

Surgery for infective endocarditis (IE) is technically demanding, especially the one for active IE.

METHODS

Operations were performed in 21 patients with a mean age of 52.2 +/- 18.8 years. Fifteen patients were male, and 6 were female. There were 15 patients with active IE and 6 patients with healed IE. Isolated pathogens were Streptococcus in 8 cases, Staphylococcus in 3, and Enterococcus in 2. Two patients had prosthetic valve endocarditis. When the lesions affected the aortic valve, aortic valve replacement (AVR) was performed. When the lesions affected the mitral or tricuspid valves, valve repair was the treatment of choice.

RESULTS

Six patients underwent AVR and 15 patients underwent a mitral valve operation (mitral valve repair in 13, replacement in 2). In 2 patients, mitral valve repair was changed to replacement, judged by intraoperative transesophageal echocardiogram. One patient underwent isolated tricuspid valve repair. Total survival and survival free of reoperation at 45 months was 95.2%. The grade of mitral regurgitation (MR) decreased from 3.7 +/- 0.1 to 0.2 +/- 0.1, and that of tricuspid valve regurgitation (TR) recovered from 3.5 +/- 0.5 to 1.0 +/- 1.0 at 21 +/- 15 months after the operation.

CONCLUSIONS

Valve repair operations were useful in the mitral and tricuspid valve positions, even in the presence of active IE. Both mechanical valve and bioprosthesis showed good results after AVR for IE.

Prognostic significance of the expression of MUC1 and collagen type IV in advanced gastric carcinoma

Background

Scirrhous gastric carcinoma is characterized by excessive deposition of collagen in the stroma. However, the clinical significance of this fibrosis of the stomach has not been clarified. The aim of this study was to examine the fibrotic mechanism in several histological types of gastric carcinoma, and the combination of MUC1 and collagen type IV as a possible predictor of patient survival.

Methods

One hundred and two paraffin-embedded specimens of gastric carcinoma were examined by immunohistochemical staining using monoclonal antibodies against collagen type IV and MUC1.

Results

Collagen type IV-positive expression was significantly associated with depth of wall penetration (P = 0·025) and stage (P = 0·023). There was a significant relationship between MUC1-positive expression and interstitial collagen type IV-positive expression (P = 0·035). Survival was shorter for patients with the combination of MUC1-positive expression and interstitial collagen type IV-negative expression than for those with other expression patterns.

Conclusion

In patients with differentiated-type advanced gastric carcinoma, the combination of MUC1-positive and interstitial collagen type IV-negative expression may be a marker of unfavourable prognosis.

Investigation of new cytogenetic biomarkers specific to high-LET radiation usingin vivoandin vitroexposed human lymphocytes

PURPOSE

To find detectable cytogenetic biomarkers that can offer information about the radiation quality of in vivo exposure retrospectively.

MATERIALS AND METHODS

Chromosome-type aberrations of peripheral lymphocytes of uterine cancer patients that received internal gamma- and external X-ray therapy or carbon beam therapy and of victims severely exposed to neutrons and gamma-rays in a criticality accident that occurred in Tokai-mura, Japan were analysed. Data obtained from in vitro irradiation experiments using 60Co gamma-rays and 10 MeV neutrons were compared with the in vivo exposure data.

RESULTS

The ratio of acentric rings to dicentric chromosomes (termed RaD ratio) and that of excess fragments to dicentrics (termed EfD ratio) showed significant (p < 0.05) differences between the two groups of cancer patients, and these ratios for accidental victims were in between the values of the two groups of cancer patients. The in vitro studies using doses equivalent to 1 - 3 Gy of gamma-rays have confirmed that the EfD ratios were increased with the high LET (linear energy transfer) and RaD ratios decreased.

CONCLUSION

The present data show that the RaD and EfD ratios can be used as cytogenetic biomarkers of exposure to high-LET radiation at least within a few years of exposure.

Carbon ion radiotherapy for malignant melanoma of female genital organs

e16548

Background: Malignant melanoma of the female genital organs is a very rare tumor and resistant to conventional photon radiotherapy. We report six cases of female genital malignant melanoma those were well controlled locally by carbon ion radiotherapy (CIRT). Methods: Between November 2004 and October 2008, six patients with unresectable female genital malignant melanoma were treated with CIRT. Age of the patients ranged from 55 to 80 years (median; 69 years). Four patients had previously untreated locally invasive tumors and other two had locally recurrent tumors after surgery and adjuvant chemotherapy. The tumor located in the vagina (4 patients), both the cervix and the vagina (1 patient), or both the vagina and the vulva (1 patient). Two patients had inguinal lymph node metastasis and two had distant metastases at CIRT. All patients received a total dose of 57.6 gray equivalent (GyE) in 16 fractions over 4 weeks of CIRT. Three patients received chemotherapy using dacarbazine, ACNU, and vincristine after CIRT. Results: The follow-up durations after CIRT were from 9 to 20 months (median; 13 months). No patient developed severe acute toxicity during CIRT. No late toxicity of greater Grade 2 was experienced, while Grade 1 proctitis was observed in a patient. All tumors completely responded to CIRT. No patient developed in-field recurrence. The four patients without distant metastasis were alive with no evidence of disease for 9–20 months after CIRT. The two patients with distant metastases died from metastatic disease 13 and 18 months after CIRT, respectively. Conclusions: CIRT achieved favorable local tumor control without developing severe acute and late toxicity in the treatment of unresectable malignant melanoma of the female genital organs.

No significant financial relationships to disclose.

Gene expression of transforming growth factor-beta1 and hepatocyte growth factor during wound healing of injured rat vocal fold

OBJECTIVES/HYPOTHESIS

To investigate the expression of genes coding transforming growth factor (TGF)-beta1, hepatocyte growth factor (HGF), and c-Met, its membrane-spanning tyrosine kinase receptor, during the inflammatory, proliferative, and remodeling phases of wound healing in the injured rat vocal fold.

STUDY DESIGN

Prospective animal study.

METHODS

Thirty five rats were involved in this study. Bilateral vocal fold wounds were created in 30 rats. Injured vocal fold specimens were harvested on postinjury day 1, 3, 7, 14, 28, and 56. Real-time polymerase chain reaction (PCR) was used to quantify mRNA expression of TGF-beta1, HGF, and c-Met. Five uninjured rats were used to establish PCR control.

RESULTS

Results of analysis of variance revealed a significant main effect for TGF-beta1 (P = .000), HGF (P = .000), and c-Met (P = .000) expression across time points. Post-hoc testing revealed that TGF-beta1 expression increased significantly on postinjury day 7 (P = .001) compared to control. HGF expression decreased significantly on postinjury day 1 (P = .001), and increased significantly on postinjury day 14 (P = .000). c-Met expression decreased significantly on postinjury day 1 (P = .000), day 3 (P = .000), and day 56 (P = .000), and increased significantly on postinjury day 28 (P = .000).

CONCLUSIONS

Results revealed time-dependent changes in the regulation of genes coding TGF-beta1, HGF, and c-Met during wound healing in the injured rat vocal fold. These patterns of gene expression correspond well with previously reported histologic changes of the rat vocal fold after injury.

Model of evoked rabbit phonation

OBJECTIVES

We describe a method for eliciting phonation in an in vivo rabbit preparation using low-frequency, bipolar pulsed stimulation of the cricothyroid muscles with airflow delivered to the glottis.

METHODS

Ten New Zealand White breeder rabbits weighing 3 to 5 kg were used in this study. The cricothyroid muscles were isolated bilaterally, and separate pairs of anode-cathode hooked-wire electrodes were inserted into each muscle. A Grass S-88 stimulator and 2 constant-current PSIU6 isolation units were used to deliver bipolar square wave pulses to each cricothyroid muscle, with airflow delivered to the glottis through a cuffed endotracheal tube.

RESULTS

Phonation was evoked with a 50-Hz, 4-mA stimulus train of 1-ms pulses delivered to each cricothyroid muscle. The pulse trains were on for 2 seconds and were repeated every 5 seconds over a period of 180 minutes. Airflow was delivered at 143 cm3/s, producing phonation measuring 71 to 85 dB sound pressure level.

CONCLUSIONS

Evoked phonation is feasible in rabbits by use of bipolar stimulation of the cricothyroid muscles with airflow delivered to the glottis. The in vivo rabbit preparation described may provide a useful small animal option for studies of evoked phonation. From the level and consistency of the adduction observed, we hypothesize that current spreading to the underlying adductor muscles and nerves resulted in neural pathway involvement beyond discrete activation of the cricothyroid muscle, providing sufficient approximation of the vocal folds for phonation.

Fluorine diffusion assisted by diffusing silicon on the Si(111)-(7x7) surface

The diffusion process of fluorine (F) atoms on the Si(111)-(7x7) surface is investigated using high-temperature scanning tunneling microscopy. The kinetic parameters of F hopping agree well with those of the diffusing silicon (Si) atoms, which implies that of all reaction processes, the Si diffusion serves as the rate-determining one. Deposition of Si on the surface is found to enhance F hopping, which supports the above-mentioned observation. Theory reveals that the replacement of F adsorption sites by diffusing Si atoms is the key process in the diffusion mechanism.