Development of Automated Delivery Quality Assurance Analysis Software for Helical Tomotherapy

BACKGROUND

To develop a fully automated in-house gamma analysis software for the "Cheese" phantom-based delivery quality assurance (QA) of helical tomotherapy plans.

METHODS

The developed in-house software was designed to automate several procedures, which need to be manually performed using commercial software packages. The region of interest for the analysis was automatically selected by cropping out film edges and thresholding dose values (>10% of the maximum dose). The film-measured dose was automatically aligned to the computed dose using an image registration algorithm. An optimal film scaling factor was determined to maximize the percentage of pixels passing gamma (gamma passing rate) between the measured and computed doses (3%/3 mm criteria). This gamma analysis was repeated by introducing setup uncertainties in the anterior-posterior direction. For 73 tomotherapy plans, the gamma analysis results using the developed software were compared to those analyzed by medical physicists using a commercial software package.

RESULTS

The developed software successfully automated the gamma analysis for the tomotherapy delivery quality assurance. The gamma passing rate (GPR) calculated by the developed software was higher than that by the clinically used software by 3.0%, on average. While, for 1 of the 73 plans, the GPR by the manual gamma analysis was higher than 90% (pass/fail criteria), the gamma analysis using the developed software resulted in fail (GPR < 90%).

CONCLUSIONS

The use of automated and standardized gamma analysis software can improve both the clinical efficiency and veracity of the analysis results. Furthermore, the gamma analyses with various film scaling factors and setup uncertainties will provide clinically useful information for further investigations.

Intravascular ultrasound-guided optimization for chronic total occlusion-percutaneous coronary intervention with multiple drug-eluting stents

Background

Multiple stenting in the chronic total occlusion (CTO) lesions is frequently required, however associated with poorer clinical outcomes. It is demonstrated that intravascular ultrasound (IVUS)-guided CTO-percutaneous coronary intervention (PCI) is related to a lower risk of adverse clinical events.

Purpose

We aimed to evaluate the clinical impact of stent optimization under IVUS guidance for multiple stenting, comparing with single stenting.

Methods

A total of 916 patients receiving drug-eluting stent (DES) under IVUS guidance were classified into two groups (stent optimization and non-optimization) according to optimization criteria (an absolute expansion criteria; minimal stent area ≥4.9 mm2 and a relative expansion criteria; 80% of mean reference lumen area). Of total population, 314 patients (34.3%) were treated with single stent and 575 patients (62.7%) were treated with multiple stents, respectively. Ischemic-driven target-lesion revascularization (TLR)/reocclusion was evaluated.

Results

Under IVUS guidance, 316 patients (34.5%) met IVUS criteria for stent optimization The achieving rates were 53% in the single stent group and 24% in the multiple stents group, respectively, (p&lt;0.001). During a median of 4.7 years, the multiple stent group showed a significantly higher TLR/reocclusion rate, compared with the single stent group (12.8% vs. 5.2%, adjusted hazard ratio [HR] 2.51, 95% confidence interval [CI] 1.20–5.25, p=0.01). (Figure 1) Meeting both the absolute and relative expansion criteria was associated with a significantly low rate of TLR/reocclusion rate (12.5% vs. 5.2%, adjusted HR 0.34, 95% CI: 0.15–0.79, p=0.01). Under IVUS-guidance, there was no significant difference between multiple stenting and single stenting in case of achieving the optimization criteria (6.5% vs. 4.2%, p=0.11), whereas non-optimization group in the patients with multiple stenting showed a significantly higher rate of TLR/reocclusion, compared with IVUS-optimization group in the patients with single stenting (14.5% vs. 4.2%, p=0.002). (Figure 2)

Conclusions

In CTO-PCI with DES, multiple stenting significantly increased the risk of TLR/reocclusion. IVUS-guided optimization for multiple stenting showed a comparable long-term risk of TLR/reocclusion to single stenting with IVUS optimization. Hence, achieving IVUS expansion criteria may help to reduce the risk of TLR/reocclusion in CTO-PCI with multiple DES overlapping.

Funding Acknowledgement

Type of funding sources: None.

Heart Rate Variability Measurement in Sepsis Patients

Objectives

Inflammation makes an influence on autonomic nervous system and a change in autonomic nervous activity affects heart rate. Heart rate variability (HRV) test can quantify the autonomous nervous activity. In this study, we evaluated the meaning of heart rate variability in sepsis patients.

Methods

Heart rate variability test was performed for sepsis patients and healthy volunteers. Normalised low frequency power, reflecting sympathetic activity, was compared to acute physiology and chronic health evaluation II (APACHE II) score and mortality in emergency department sepsis (MEDS) score in sepsis patients. Then the patients were divided into four groups: 1) severe sepsis patients, 2) sepsis patients admitted to general ward, 3) sepsis patients discharged within 24 hours and 4) healthy volunteers. We obtained averages for the HRV results in all four groups. The receiver operating characteristics curve was examined to determine whether or not HRV variables could be used to triage sepsis patients.

Results

Correlations between normalised low frequency power (LFnu) with APACHE II score and MEDS score were −0.595 and −0.514, respectively. Low frequency power (LF) and LFnu values decreased in sepsis patients with the higher scores observed in the discharged sepsis patients and healthy volunteers. The areas under the curve for the values of LF and LFnu in the admission and discharge groups were 0.746 and 0.635, respectively (p<0.05).

Conclusion

Variables related to heart rate variability are significantly correlated with the severity of sepsis patients. Although the HRV test alone cannot accurately predict the disposition of sepsis patients, in the emergency room setting it helps to assign beds to sepsis patients within the triage system, and avoid over-population. (Hong Kong j.emerg.med. 2014;21:73-79)

Recurrent Obturator Hernia as a Cause of Nonspecific Abdominal Pain: A Case Report

Many patients visit the emergency department (ED) with abdominal pain. Sometimes, physicians are faced with diagnostic challenges, particularly for older patients. We recently had an elderly female patient who visited the ED several times with non-specific abdominal pain caused by an unusual hernia. One year before, an 81-year-old female visited our ED complaining of abdominal pain radiating to the right inguinal/femoral area. An incarcerated obturator hernia was found on an abdomino-pelvic computed tomography (CT) scan, and she underwent a laparoscopic hernioplasty. However, 1 year later, she revisited complaining of abdominal pain similar to the previous episode. Eventually, the diagnosis of recurrent obturator hernia was made, and a second operation was performed. An obturator hernia may be the cause of non-specific abdominal pain and small bowel obstruction in elderly emaciated females. Recognising the clinical signs and characteristics of this disease is necessary for a prompt diagnosis and treatment.

Effect of Topical Mitomycin C on the Healing of Surgical and Laser Wounds: A Hint on Clinical Application

OBJECTIVES: Mitomycin C (MMC) is used in otolaryngological surgery to reduce complications from postoperative scarring. However, the effects of MMC on wound healing at different doses and on different wound types have not been fully described. The aim of this study was to evaluate the effects of topical MMC at 2 different doses on the healing of surgical and laser wounds.

STUDY DESIGN AND SETTING: This was a randomized study using 20 rabbits. Six full-thickness wounds were made by excision or laser vaporization on the flank skin. The wounds were randomly treated by topical MMC of 0.4 or 1.0 mg/mL or saline for 5 minutes.

RESULTS: Re-epithelialization and contraction of the original wounds were significantly delayed by the use of MMC ( P < 0.01). The delayed healing effect of MMC was more prominent in the laser wounds than in the excision wounds. MMC inhibited collagen deposition and fibroblast proliferation of wounds on histological analysis. The 2 different concentrations of MMC showed no difference in gross or histological wound healing characteristics.

CONCLUSION: Our results showed that MMC delays the healing of wounds as a result of the inhibition of fibrosis, especially for laser wounds.

Removal of nonthyroidal neck masses with improved cosmetic outcomes in skin-lifting surgery

Objective

To evaluate the cosmetic benefit of neck skin-lifting surgery for the removal of nonthyroidal neck masses.

Study Design and Setting

Fifty patients with neck masses were divided into the following 2 surgical groups that were matched in age, sex, and the size, location, and pathology of lesions: skin lifting (n = 25) and conventional (n = 25). The operation time, hospital stay, complications, and subjective satisfaction with the incision scar as assessed on a visual analogue scale (VAS) were compared between the 2 groups.

Results

All but 2 lesions (lymphomas) were benign and were removed completely, drained, or biopsied. The surgery time, hospital stay, and complication rates did not differ significantly between the groups. The mean satisfaction score of the patients was 8.2 ± 1.1 in the skin-lifting surgery group and 4.8 ± 2.5 in the controls ( P < 0.001). The incision scars were commonly hidden by natural hair or collars in the patients who received skin-lifting surgery.

Conclusion

This surgical technique can be safely applied to most benign masses in the entire neck excluding the thyroid region, especially in patients who prefer neck scars to be invisible. EBM rating: B-2b

Decision support for ecological river rehabilitation using fish habitat database

After the recent success of several river rehabilitation projects including the Cheong-gye river case, a large number of local governments have been promoting their own projects in Korea. Most of the projects are aimed at securing the soundness of aquatic ecosystems according to the guidelines presented by the Korea Ministry of Environment. However, there is no clear guidance for the management goals of water quality and quantity. In this study, we have made an attempt to construct a habitat database (DB) for each domestic freshwater fish species. The fish population, and physical and physicochemical properties of the habitat of 70 domestic freshwater fish species were investigated using field monitoring data. After the statistical processing, the inhabitable range and optimal range of each species were suggested. Furthermore, based on the DB, a decision support system for ecological river restoration and rehabilitation has been developed, and applied for field tests. It became clear that the decision support procedure based on the fish habitat DB is useful in the planning stage of river rehabilitation projects to select the flagship fish, to decide the restoration goals considering their appropriate habitat and to suggest the optimum quantitative combination of each available water resource.

Prediction of occult central lymph node metastasis in papillary thyroid carcinoma by preoperative BRAF analysis using fine-needle aspiration biopsy: a prospective study

CONTEXT

Few reports have determined whether preoperative detection of the BRAF V600E mutation in fine-needle aspiration biopsy (FNAB) may influence determination of surgical extent such as prophylactic central lymph node dissection (CLND) in patients with papillary thyroid carcinoma (PTC).

OBJECTIVES

Our objectives were to investigate whether preoperative BRAF analysis may assist determination of surgical extent, including prophylactic CLND with variable clinicopathological risk factors for central lymph node metastasis, in patients with PTC and clinically node-negative neck.

PATIENTS AND METHODS

From July 2009 to May 2011, we prospectively enrolled 148 PTC patients with clinically node-negative neck who received a total thyroidectomy and prophylactic CLND. BRAF mutation by pyrosequencing was tested on preoperative FNAB specimens. The relationships between occult central lymph node metastasis and preoperative BRAF mutation or clinicopathological factors were analyzed. Additionally, we assessed the associations between preoperative BRAF mutation status and various clinicopathological characteristics of PTC revealed postoperatively.

RESULTS

The prevalence of the BRAF V600E mutation was 53.4%, and the rate of occult central lymph node metastasis was 25.7%. Multivariate analysis showed that tumor size over 1 cm [P = 0.006; odds ratio (OR) = 3.559], perithyroidal invasion (P = 0.023; OR = 2.893), and preoperative positive BRAF mutation (P = 0.029; OR = 2.727) were independent risk factors for the presence of occult central lymph node metastasis. BRAF mutation examined in FNAB specimens, compared with the wild-type allele, strongly predicted perithyroidal invasion (48 vs. 29%; P = 0.017), extracapsular spread (65 vs. 45%; P = 0.017), occult central lymph node metastasis (35 vs. 15%; P = 0.004), and advanced TNM stage (44 vs. 28%; P = 0.035). In the multivariate analysis, patients with preoperative positive BRAF mutation were significantly more likely (P = 0.023; OR = 2.848) to have occult central lymph node metastasis.

CONCLUSION

Preoperative BRAF analysis by FNAB and primary tumor size based on ultrasonography may assist in predicting occult central lymph node metastasis in patients with PTC and clinically node-negative neck.

Pattern of expression of cyclooxygenase-2 in malignant transformation of sinonasal inverted papilloma

OBJECTIVE

Cyclooxygenases (COXs) are enzymes that catalyze the conversion of arachidonic acid to prostaglandins. Many studies have suggested that COX-2, the inducible form of COX, is important in carcinogenesis. However, little is known about the pattern of expression of COX-2 in a multistep process of malignant transformation of sinonasal inverted papilloma (IP). In this study, we investigated COX-2 expression in IPs, IPs with dysplasia, IPs with squamous cell carcinoma (SCC), and primary SCCs of sinonasal tract.

STUDY DESIGN

A retrospective study was conducted.

SETTING

The setting was a tertiary care referral center.

SUBJECTS AND METHODS

The expression of COX-2 was evaluated by immunohistochemistry in 56, 7, 18, and 17 cases of IPs, IPs with dysplasia, IPs with SCC, and primary SCCs, respectively. Furthermore, we investigated the possible correlation between the expression of COX-2 and clinicopathologic variables in patients with IPs with SCC and primary SCC patients.

RESULTS

Positive immunoreactivity for COX-2 was observed in 3 (5.4%) of 56 IPs, 7 (38.9%) of 18 IPs with SCC, and 7 (41.2%) of 17 primary SCCs, whereas it was not observed in IPs with dysplasia. The percentage of tumors with COX-2-positive immunostaining was significantly higher in IPs with SCC and primary SCCs compared with benign IPs. There was no significant correlation between the expression of COX-2 and clinicopathologic variables, such as tumor stage, histologic differentiation, and the proportion of malignant areas in patients with IPs with SCC.

CONCLUSION

Cyclooxygenase-2 may play an important role in the process of malignant transformation from IP to SCC.

Expression of matrix metalloproteinase-12 is correlated with extracapsular spread of tumor from nodes with metastasis in head and neck squamous cell carcinoma

Matrix metalloproteinases (MMPs) play an important role in tumor invasiveness and metastasis. The aim of this study was to investigate the expression pattern of MMPs in the primary tumor of head and neck squamous cell carcinomas (HNSCC) with cervical node metastasis and to correlate the expression of MMP in the primary tumor with the presence of extracapsular spread (ECS) in nodes with metastasis. A retrospective study was conducted. Paraffin blocks were obtained from 40 HNSCC patients with cervical node metastasis who underwent surgery as an initial treatment between 2004 and 2011. Expressions of MMP-2, MMP-3, MMP-12, and MMP-14 were investigated immunohistochemically. MMP-2, MMP-3, MMP-12, and MMP-14 were expressed in 27, 47.5, 55, and 57.5 % of cases, respectively. MMP-12 expression was found to be significantly associated with ECS and correlated with nodal metastasis (p = 0.024, 0.011). No relation was found between MMP expression and survival. MMP-12 expressed in the primary tumor is a molecular marker that may be useful for predicting ECS in HNSCC patients with metastatic nodal disease.

Is there any synergic effect for coadministration of mitomycin C and halofuginone on the skin wound healing?

OBJECTIVE

This study compared the potencies of the antifibrotic agents mitomycin C (MMC) and halofuginone (HFN) and investigated whether coadministration of these agents produces synergic effects in an animal skin wound model.

SUBJECTS AND METHODS

Twenty male Sprague-Dawley rats were used for this study. After a full-thickness excisional wound was made on the dorsum of each rat, each rat was treated with topical mitomycin, intraperitoneal HFN, or both. Wound surface areas were measured over time, and histologic analysis was performed after wounds healed completely.

RESULTS

The groups treated with MMC alone, HFN alone, and a combination of the two all exhibited delayed wound healing compared with the untreated group. Histologically, fibrosis and matrix metalloproteinase-2 expression were significantly inhibited in the treated groups. However, there were no gross or histologic differences between the MMC-treated group, the HFN-treated group, and the combination-treatment group.

CONCLUSIONS

Both MMC and HFN inhibited excessive fibrosis. However, there was no significant difference in the antifibrotic effects of MMC and HFN on surgically induced skin wounds. Moreover, combination treatment with both MMC and HFN failed to confer an additional antifibrotic effect on skin wounds when compared with treatment with MMC or HFN alone.

Medium-induced radiationless transitions and effect of solvent on radiationless transitions

The purpose of this paper has been to investigate the effect of solvent on radiationless transitions. Two types of the solvent effect have been studied: one is the so-called medium-induced radiationless transition, i.e., the radiationless transition induced by the interaction between the solute and solvent, and the other is the effect of solvent on the radiationless transition through the change in energy gap induced by the solute-solvent interaction.

Occult contralateral carcinoma in patients with unilateral papillary thyroid microcarcinoma

BACKGROUND

The optimal resection extent for papillary thyroid microcarcinoma (PTMC) confined within a unilateral lobe remains controversial.

MATERIALS AND METHODS

We reviewed the medical records of 132 consecutive patients who underwent total thyroidectomy for the treatment of clinically unilateral PTMC between March 2005 and March 2009. The frequency, pattern, and predictive factors for occult contralateral carcinoma in these patients were analyzed with respect to the following variables: age, gender, tumor size, multifocality of primary tumor, presence of perithyroidal invasion, lymphovascular invasion or capsular invasion, presence of central lymph node metastasis, and the presence of coexistent benign nodules in the contralateral lobe based on preoperative evaluation and final pathology.

RESULTS

A total of 22 patients (16.7%) had occult PTMC in the contralateral lobe. In multivariate analysis, multifocality of the primary tumor (P = 0.026, odds ratio = 7.714) and the presence of coexistent benign nodule in the contralateral lobe by preoperative evaluation (P = 0.036, odds ratio = 3.500) were independent predictive factors for occult contralateral PTMC presence. However, there were no significant differences between the presence of occult contralateral carcinomas and age, gender, tumor size, perithyroidal invasion, lymphovascular invasion, capsular invasion, central lymph node metastasis, and coexistent benign nodules by final pathology.

CONCLUSIONS

Based on our findings, total thyroidectomy, including the contralateral lobe, should be considered for the treatment of unilateral PTMC if it presents as a multifocal tumor in the unilateral lobe and/or if nodules are found in the contralateral lobe during preoperative evaluation.

Submitral left ventricular aneurysm of ischemic origin: report of two surgical cases

Submitral left ventricular aneurysm has been exclusively recognized in the young African population and its occurrence in other than black Africans is rarely reported. Here we describe two surgical cases of submitral left ventricular aneurysm in Asian elderly persons. Although the aneurysms were typically located beneath the posterior mitral valve leaflet, we could identify diseased coronary arteries as well, unlike the reports in the literature asserting that this type of aneurysm occurs in the absence of coronary disease. The possible racial difference with regard to the etiology is addressed.

Occult lymph node metastases in neck level V in papillary thyroid carcinoma

BACKGROUND

The extent of lateral neck dissection for clinically evident nodal metastases in the lateral neck in a patient with papillary thyroid cancer (PTC) continues to remain controversial.

METHODS

We reviewed retrospectively the medical records between March 2005 and March 2008 of 70 patients with PTC who underwent therapeutic lateral neck dissections (level II-V) to establish indications for omission of a level V lymphadenectomy. No patient in the study had a clinically positive level V lymph node. Neck dissection specimens were obtained for histologic analysis for node metastasis with respect to the individual neck levels.

RESULTS

Thirty-four (49%), 52 (74%), and 48 (69%) patients had histologically positive lymph nodes in levels II, III, and IV, respectively. Occult metastases in level V were observed in 11 (16%) patients. Isolated positive level V lymph nodes were never found, while all patients with positive level V lymph nodes had simultaneous positive level IV lymph nodes. In addition, there was no instance of a pathologically positive lymph node in level V without a suspicious metastatic lymph node in level IV by preoperative ultrasonography. In multivariate analysis, simultaneous multilevel involvement (level II, III, and IV) of lymphatic metastases was associated with level V metastasis.

CONCLUSION

Level V lymphadenectomy may be omitted in the treatment of PTC patients if positive nodes are not found on histologic exam (frozen section analysis) or by ultrasonography in level IV.

Iatrogenic ear lobule ischemic injury from pressure dressing as an unusual complication of parotidectomy

The use of compressive dressing is usually spread to enhance neovascularization of the dissected facial flap by elimination of dead space between the flap and the dermis in parotid surgery through facelift incision. The author reports a clinical case of compressive dressing after parotidectomy that was inappropriately performed to folding of the ear lobule, leading to ischemic injury. This iatrogenic complication resulted in the development of contracture of ear lobule and deformity of auricle. Consequently, careful compressive dressing after parotidectomy through facelift incision must be applied; and the wound must be inspected daily for early detection and prompt treatment of local complications.

Sialectasis of Stensen's duct: an unusual case of recurrent cheek swelling

Sialectasis of Stensen's duct is an uncommon condition of the salivary gland featuring dilation of the parotid duct. Various surgical and non-surgical treatment modalities have been reported as treatment for Stensen's duct stenosis. In this report, a rare case of sialectasis with fusiform dilatation of the parotid duct is presented, which was corrected by a simple and easy surgical technique creating a new opening in the buccal mucosa.

Cervical sensory preservation during neck dissection

Although the practice of neck dissection has greatly advanced from radical to function-preserving surgery, the impact of the sensory nerve-preserving neck surgery on the pain and quality of life (QOL) of patients has received little study. We evaluated neck morbidity and its impact on QOL associated with selective or modified radical neck dissection with or without preservation of cervical root branches. We conducted a retrospective cohort study comparing 24 patients who had their cervical root branches preserved to 29 patients whose root branches were removed during neck dissection. The spinal accessory nerve was preserved and sex, age, pathologic status, side and extent of neck dissection, and radiotherapy were comparable between groups. The groups were compared based on sensory and motor functions of the neck and shoulder and questionnaires on depression and QOL at follow-up of mean 18.7 (range 12-34) months after surgery. The nerve-preserved patients showed a low incidence and severity of neck and shoulder pain compared to the nerve-removed subjects (p<.05). Loss of sensation was more frequently experienced in the nerve-removed group on the earlobe and the lateral neck of the operated side (p<.05). Depression and QOL scores were higher in the nerve-removed group and significantly correlated with pain intensity. Preservation of the cervical root branches reduces postoperative pain as well as permanent anesthetic areas of the neck. This may also improve the mental state and QOL of patients undergoing neck dissection.

Effect of Acid and Pepsin on Glottic Wound Healing

OBJECTIVE

To evaluate the effects of acid and pepsin on the healing of traumatized vocal folds in a simulated reflux model. Gastroesophageal reflux is related to various laryngeal manifestations. However, there is a lack of established reflux animal models that would ensure longer observation periods.

DESIGN

A prospective randomized animal study.

INTERVENTIONS

Forty-two rabbits underwent a stripping procedure of the unilateral glottis and catheter insertion under transoral endoscopic guidance. The animals were randomly assigned to a control group (n = 21; isotonic sodium chloride was used) or a reflux group (n = 21, acid and pepsin were used). They received intrapharyngeal catheter irrigation with 3 mL of isotonic sodium chloride or a solution of acid with a pH of 3 and pepsin, 0.3 mg/mL, twice daily for 4 or 8 weeks after surgery.

MAIN OUTCOME MEASURES

Gross and histologic findings of the preinjured glottides of the 2 groups were compared.

RESULTS

The catheter extrusion rate was significantly low (6%), and any catheter problems were immediately solved by reinsertion or reconnection. The extent of glottic scarring and frequency of granulation formation were higher in the reflux group compared with the control group (P<.05). Histologic inflammation scores and collagen deposition were significantly greater in the reflux group compared with the control group (P<.05).

CONCLUSIONS

Our data suggest that glottic wound healing is significantly affected by acid and pepsin. Antireflux treatment can be advocated to minimize further injury caused by gastroesophageal reflux in patients who undergo laryngeal surgery.

Prevention of hypopharyngeal stenosis with silastic sheeting following transoral resection

Hypopharyngeal stenosis following transoral laser microresection (TLM) of hypopharyngeal carcinomas is a rare but devastating complication. Early oral intake and insertion of a nasogastric feeding tube have been thought to prevent stenosis after surgery. However, though rare, severe dysphagia can be caused by hypopharyngeal stenosis following TLM despite preventive efforts. We suggest a new way to prevent hypopharyngeal stenosis by using silastic sheeting with a feeding tube. This stent was inserted in three patients who underwent extensive TLM of hypopharyngeal carcinomas. This technique will help in the treatment and prevention of hypopharyngeal stenosis following TLM in selected patients with wide or circumferential hypopharyngeal tumors.

Prevention of Anterior Glottic Stenosis After Bilateral Vocal Fold Stripping With Mitomycin C

OBJECTIVE

To examine the effects of immediate application of topical mitomycin C (MMC) on the prevention of anterior glottic stenosis (AGS) after microsurgical stripping of both vocal folds, including the anterior commissure, in a canine model.

DESIGN

Prospective randomized experimental study.

INTERVENTIONS

Twelve canine larynges were injured by a stripping procedure of both entire membranous vocal folds. The dogs were randomly divided into 2 groups for treatment with 1.0 mg/mL of MMC or with isotonic sodium chloride solution (control) for 5 minutes immediately after surgery. Three and 6 weeks after surgery, the glottic webs were lysed and repeatedly treated with MMC or isotonic sodium chloride solution. The glottic wound healing and AGS formation were examined every week. Ten weeks after the initial surgery, all larynges were collected and examined histologically.

RESULTS

The stripping procedure induced AGS, affecting 58% to 86% (mean, 72%) of the length from the anterior commissure to the vocal process in the control group. The application of MMC at the time of initial surgery significantly lowered the incidence and extent of the web formation (P = .004). The AGS lesions were resolved by web lysis and treatment with MMC, without significant local adverse effects. Histological staining for collagen and elastin revealed that MMC treatment did not induce excessive fibrotic or atrophic changes in the lamina propria of the vocal folds.

CONCLUSION

Bilateral stripping of the membranous vocal folds induces significant AGS, which can be minimized by use of MMC at initial surgery.

Prevention of Anterior Glottic Stenosis after Transoral Microresection of Glottic Lesions Involving the Anterior Commissure with Mitomycin C

OBJECTIVE

To evaluate the effectiveness of topical mitomycin C (MMC) in preventing anterior glottic stenosis (AGS) after transoral microresection of glottic lesions involving the anterior commissure (AC).

STUDY DESIGN

Prospective clinical study.

METHODS

Sixteen patients with benign or malignant glottic lesions involving the AC were studied. The lesions were removed by transoral microsurgery using a CO2 laser or cold microinstruments. In all patients, the anterior glottis was treated topically with 0.4 mg/mL MMC for 5 minutes at the end of surgery. The postoperative vocal folds and voice quality of patients were evaluated using video strobolaryngoscopy and voice recordings.

RESULTS

Four patients had local recurrences after surgery and were treated with repeat microsurgery. Postoperatively, five patients (31%) developed acceptable small webs in the anterior glottis; one resolved with web lysis and a second with topical MMC. Postoperative vocal quality was affected mainly by the extent of vocal fold resection and the subsequent wide glottal gaps and extensive scarring, rather than by MMC use per se. Significant local side effects or atrophy of the vocal folds owing to MMC were not found.

CONCLUSION

Topical MMC may be useful for preventing AGS and subsequent dysphonia after transoral microresection of glottic lesions involving the AC.

The distribution of soiling by coarse particulate matter in the museum environment

Soiling measurements are needed to address strategies to control dust and determine its sources. There is no widely recognized method for dust monitoring in museums, but we used sticky samplers to collect deposited coarse particulate matter, and both manual microscopic observations and image analysis for determining soiling potential in the museum environment. We adopt fractional area covered by deposited particles as a surrogate for soiling and the covering rate (unit: s-1) as a measure of the rate of soiling. It was clear that visitor flow was a major contributor to soiling, such that soiling mechanisms in different museums could be compared after measurements were normalised on a per capita basis. The proximity of visitors to objects was another important factor with the soiling declining with distance from visitor pathways (a half-distance of about 0.5 m), which suggests soiling of objects on open display could be reduced by increasing the distance from visitors.

Reconstruction of basement membrane in skin equivalent; role of laminin-1

To reconstruct the basement membrane in a skin equivalent, the epidermodermal interface was coated with porcine type IV collagen and mouse laminin-1 at various ratios before keratinocyte seeding. Laminin-1, a component of the basement membrane, induced massive infiltration of keratinocytes into the dermal equivalent, while type IV collagen induced discrete demarcation between dermal and epidermal compartments without any infiltrating cells. Immunohistochemical staining indicated that the laminin-induced infiltrating cells expressed endogenous type IV collagens at the cell periphery, which were not incorporated into the basement membrane structure. The infiltrating cells did not express fibronectin receptor alpha5beta1 integrin but showed MMP-9 secretion and cell surface associated MMP-2. However, when laminin-1 was preincubated with type IV collagen, laminin-1-induced keratinocyte infiltration as well as MMP-9 induction were almost completely suppressed to basal levels. Therefore, replenishment of the type IV collagen lattice seemed to cause laminin-stimulated cells to anchor to the lattice, in a similar manner to the basal cells on the basement membrane of normal skin. Our study suggests that the molar ratio of basement membrane components may determine the behavior of basal cells within the wound healing microenvironment, which is probably regulated either by extracellular matrix deposition or degradation.

Depletion of intracellular zinc and copper with TPEN results in apoptosis of cultured human retinal pigment epithelial cells

PURPOSE

Although zinc deficiency may contribute to the pathogenesis of age-related macular degeneration, how it leads to retinal pigment epithelium (RPE) degeneration is unknown. To investigate this, cultured human RPE cells were rendered zinc depleted with a membrane-permeant metal chelator, N,N,N',N-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), and the resultant cytopathic changes were examined.

METHODS

RPE cell degeneration was examined with light microscopy, TdT-mediated dUTP nick end labeling (TUNEL) staining, Hoechst dye staining, and electron microscopy and quantified with cell counting or lactate dehydrogenase release assay. The effect of sublethal zinc depletion on the vulnerability of RPE cells to UV irradiation or hydrogen peroxide (H(2)O(2)) exposure, was studied in cultures without or with pretreatment with low-concentration TPEN.

RESULTS

Exposure to 1 to 4 microM TPEN for 48 hours induced RPE cell death in a concentration-dependent manner. Features of apoptosis such as membrane blebbing, chromatin condensation, nuclear fragmentation, and caspase-3 activation, accompanied the TPEN-induced cell death. Addition of equimolar zinc or copper completely reversed TPEN-induced apoptosis, whereas addition of iron had no effect. As in apoptosis of several other cell types including neurons, a protein synthesis inhibitor as well as caspase inhibitors blocked TPEN-induced apoptosis. On the contrary, at sublethal concentrations, TPEN increased the vulnerability of RPE cells to subsequent UV irradiation but not to H(2)O(2) exposure.

CONCLUSIONS

The present results suggest that depletion of intracellular zinc and copper, but not copper alone, may be harmful to RPE cells, directly inducing apoptosis or indirectly increasing vulnerability of RPE cells to UV injury. The present culture model may be useful for gaining insights into the mechanisms of zinc depletion-associated RPE cell degeneration.

Comparison of diameter and perimeter methods for tumor volume calculation

PURPOSE

Lesion volume is often used as an end point in clinical trials of oncology therapy. We sought to compare the common method of using orthogonal diameters to estimate lesion volume (the diameter method) with a computer-assisted planimetric technique (the perimeter method).

METHODS

Radiologists reviewed 825 magnetic resonance imaging studies from 219 patients with glioblastoma multiforme. Each study had lesion volume independently estimated via the diameter and perimeter methods. Cystic areas were subtracted out or excluded from the outlined lesion. Inter- and intrareader variability was measured by using multiple readings on 48 cases. Where serial studies were available in noncystic cases, a mock response analysis was used.

RESULTS

The perimeter method had a reduced interreader and intrareader variability compared with the diameter method (using SD of differences): intrareader, 1.76 mL v 7.38 mL (P < .001); interreader, 2.51 mL v 9.07 mL (P < .001) for perimeter and diameter results, respectively. Of the 121 noncystic cases, 23 had serial data. In six (26.1%) of those 23, a classification difference occurred when the perimeter method was used versus the diameter method.

CONCLUSION

Variability of measurements was reduced with the computer-assisted perimeter method compared with the diameter method, which suggests that changes in volume can be detected more accurately with the perimeter method. The differences between these techniques seem large enough to have an impact on grading the response to therapy.

Increases in intraocular pressure during hemodialysis in eyes during early postvitrectomy period

BACKGROUND AND OBJECTIVES

To identify risk factors for intraocular pressure (IOP) increases during hemodialysis (HD) in the early postoperative period following pars plana vitrectomy (PPV).

PATIENTS AND METHODS

Comparisons of 36 vitrectomized eyes of 22 diabetics undergoing maintenance HD with those of 138 eyes of 69 nonoperated patients. Serial IOPs were measured before PPV, after PPV/before dialysis, and during dialysis. Serum osmolarity and blood pressure were also recorded.

RESULTS

In 20 of 36 operated eyes (55.6%) and 18 of 138 nonoperated eyes (13.0%) IOP was increased (> or =4 mm Hg) during HD. In the operated group, marked increases (> or =7 mm Hg) were noted in 9 eyes and ocular pain in 5 eyes. Eyes with pre-existing outflow obstruction and/or acute postoperative outflow compromise carried high risks. No correlation with changes in serum osmolarity or blood pressure was found.

CONCLUSION

Monitoring of IOP during HD seems warranted when diabetics with pre-existing outflow obstruction and/or postoperative outflow compromise, undergo HD following PPV.

Myositis ossificans of the chest wall simulating malignant neoplasm

Myositis ossificans originating from the chest wall is extremely rare. We report a case of myositis ossificans occurring in a young woman with progressive painful swelling in the chest wall. Preoperative examination suggested a malignant neoplasm originating from soft tissue. Although rare, myositis ossificans is one of the potential causes of painful swelling in the chest wall, and can be mistaken for a malignant neoplasm.

Management of persistent or recurrent pneumothorax with a two millimeter mini-videothoracoscope

The aim of this study was to assess whether a 2 mm mini-videothoracoscope could be used as a conventional videothoracoscope in the management of pneumothorax. Thirty patients of ages from 15 to 35 years with recurrent or persistent pneumothorax were involved in this study. The subjects consisted of 27 males and three females. The indications for videothoracoscopic surgery were ipsilateral recurrent pneumothorax in 12 (40%), persistent air leakage in 15 (50%), visible bullae in 2 (6%), and 1 bilateral pneumothorax (3%). The mean operation time was 42.9+/-12.9 min. The average number of uses for Endo-GIA was 1.9+/-1.3 times and chest tube indwelling time was 3.8+/-2.7 days. The average amount of keptoprofen (100 mg/2 mL/ampule) used on the first postoperative day was 1.2+/-1.1 ampules. No parenteral opioids were given to the patients for pain control after the procedures. After a follow up of 8 to 20 months, there was only one recurrence among the patients. In conclusion, a 2 mm videothoracoscope, in selective cases, can be successfully used as conventional videothoracoscope to manage persistent or recurrent pneumothorax with cosmetically excellent results.

Depletion of intracellular zinc induces macromolecule synthesis- and caspase-dependent apoptosis of cultured retinal cells

Although zinc deficiency may contribute to age-related macular degeneration (ARMD), the pathogenic mechanism is as yet uncertain. In light of evidence that cellular zinc depletion induces apoptosis in cortical neurons and thymocytes, in the present study, we examined the possibility that the same phenomenon occurs also in retinal cells. Exposure of primary retinal cell cultures to 1-3 microM of a cell membrane-permeant zinc chelator TPEN for 24 h induced concentration-dependent death of neurons, photoreceptor cells, and astrocytes. Addition of zinc or copper reversed TPEN toxicity to all cell components, indicating the particular involvement of zinc chelation in cell death. Consistent with apoptosis, oligonucleosomal DNA fragmentation and chromatin condensation accompanied, and the protein synthesis inhibitor cycloheximide blocked the TPEN-induced retinal cell death. During TPEN-induced retinal cell apoptosis, cleavage/activation of procaspase-1, but little of procaspase-3, was observed. Consistent with this finding, a broad-spectrum caspase inhibitor (zVAD-fmk) was significantly more protective than a caspase-3-selective inhibitor (DEVD-fmk). The present study has demonstrated that depletion of intracellular zinc is sufficient to induce macromolecule synthesis- and caspase-dependent apoptosis of cultured retinal cells. In light of the possibility that zinc depletion may contribute to the pathogenesis of ARMD, the current culture model may be a useful tool for the investigation of the mechanism of zinc depletion-induced retinal cell death.

Ethambutol-induced vacuolar changes and neuronal loss in rat retinal cell culture: mediation by endogenous zinc

Ethambutol is an efficacious antituberculosis agent. However, its use has been limited by the occurrence of ocular toxicity. To investigate characteristics and possible mechanisms of ethambutol ocular toxicity, we used primary rat retinal cultures as a model. Primary rat retinal cultures were obtained from newborn Sprague-Dawley rats and used for experiments after maturation (DIV > or = 10). Cytopathologic changes were examined under light and electron microscopes. Thy-1 (a membrane glycoprotein expressed by retinal ganglion neurons)-containing neurons and gamma-aminobutyric acid (GABA)-ergic neurons were identified immunocytochemically. Exposure of retinal cultures for 24-48 h to ethambutol induced cytoplasmic vacuolar changes and neuronal loss. Vacuolar changes were partially reversible with the termination of ethambutol exposure. Of neurons, Thy-1(+) ganglion neurons were more vulnerable than GABA(+) neurons. Glutamate antagonists, an antioxidant (trolox), or cycloheximide, did not attenuate either vacuolar changes or neuronal loss. A cell-permeant zinc chelator N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) markedly attenuated vacuolar degeneration and neuronal loss, while the addition of zinc augmented both. In rat retinal cultures, ethambutol induces reversible vacuolar degeneration as well as irreversible neuronal loss, more preferentially of Thy-1(+) ganglion neurons. Contrary to the current theories, ethambutol-induced retinal cytotoxicity in the present study is mediated not by excitotoxicity or zinc deficiency but by a mechanism requiring intracellular zinc. In addition, features of the ethambutol-induced cell death were not consistent with those of apoptosis.

Needle thoracic sympathectomy for essential hyperhidrosis: intermediate-term follow-up

BACKGROUND

Essential hyperhidrosis is a condition with excessive sweating localized to certain part of the body. A definitive cure can be obtained by upper thoracic sympathectomy.

METHOD

Between June and October 1997, 117 patients with essential hyperhidrosis underwent needle thoracoscopic sympathectomy. Of the 94 patients, 42 were men and 52 women. Their ages ranged from 14 to 63 years, with a mean age of 23 years.

RESULTS

There were no mortality or life-threatening complications. Symptomatic improvement was found in 95.7%. Compensatory hyperhidrosis was found in 71.2% of the patients, but in these compensatory hyperhidrosis were mostly tolerable.

CONCLUSIONS

This therapeutic procedure is minimally invasive and very effective. Further development of the new device and surgical technique are expected to follow.

An unusual type of cancer-associated retinopathy in a patient with ovarian cancer

We studied a case of unusual retinopathy in a 35-year-old woman who presented with bilateral visual deterioration due to retinal pigmentary mottling and serous elevation in the posterior pole. Two years before, she had undergone hysterectomy and bilateral salphingo-oophorectomy for ovarian cancer. Her electroretinogram became subnormal, and her fluorescein angiogram exhibited multiple deep retinal pigment epithelial leakages and subretinal dye pooling in both eyes. Corticosteroid therapy failed to prevent visual loss. She was found to possess antibodies against retinal 45 kd protein. This led to a diagnosis of cancer-associated retinopathy with atypical protein profile. We report a rare variety of cancer-associated retinopathy in a patient with-ovarian cancer.

High vulnerability of GABA-immunoreactive neurons to kainate in rat retinal cultures: correlation with the kainate-stimulated cobalt uptake

Like other areas of the central nervous system, the retina is highly vulnerable to ischemia. In particular, neurons in the inner nuclear layer, including gamma-amino butyric acid (GABA)-ergic amacrine neurons, are highly vulnerable. Since excitotoxicity is likely a major mechanism of ischemic retinal injury, using rat retinal cell culture, we examined whether GABAergic retinal neurons are differentially vulnerable to particular excitotoxins. The neuronal population as a whole, identified by anti-microtubule associated protein-2 (MAP-2) immunocytochemistry, was equally vulnerable to kainate, but more resistant to N-methyl-d-aspartate (NMDA) than cultured cortical neurons. Compared to Thy-1 immunoreactive neurons, GABA immunoreactive neurons were more vulnerable to kainate, but more resistant to NMDA neurotoxicity. Double staining of cultures with anti-GABA immunocytochemistry and the kainate-stimulated cobalt uptake method, revealed a close correlation between the two. However, unlike in other neuronal cells, there was no clear correlation between GluR2 immunoreactivity and the cobalt staining. The heightened vulnerability of GABAergic neurons to kainate, as compared to the general neuronal population, may be due to the calcium-permeable AMPA/kainate receptors they have, as identified functionally by the kainate-stimulated cobalt uptake staining. Since these neurons are preferentially injured in ischemia, AMPA/kainate receptor-mediated neurotoxicity may contribute significantly to ischemic retinal injury.

High serum lipoprotein(a) levels in Korean type 2 diabetic patients with proliferative diabetic retinopathy

OBJECTIVE

To examine the possible association between serum lipoprotein(a) [Lp(a)] concentration and proliferative diabetic retinopathy (PDR) in Korean patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 412 Korean outpatients with type 2 diabetes were examined. Diabetic retinopathy was determined by an ophthalmologist using fundoscopic examination. Serum Lp(a) levels were measured by two-site sandwich enzyme-linked immunosorbent assay.

RESULTS

The patients with PDR had higher serum Lp(a) levels than those with no diabetic retinopathy or with nonproliferative diabetic retinopathy (NPDR). Multiple logistic regression analysis showed that high serum Lp(a) levels and the presence of diabetic nephropathy were independent variables having a statistically significant association with PDR.

CONCLUSIONS

Korean type 2 diabetic patients with PDR had higher serum Lp(a) levels versus those with no diabetic retinopathy or with NPDR. Although these results suggest that Lp(a) might play a role in the occlusion of retinal capillaries leading to PDR, further prospective studies are required to prove the causal relationship.

Iron-induced cytotoxicity in cultured rat retinal neurons

Oxidative stress has been proposed as a major injury mechanism in the central nervous system including the retina. In this study, as an initial attempt to study the mechanism of oxidative injury in the retina, we developed a cell culture model by utilizing the iron exposure paradigm. Exposure of rat retinal cultures for 24 hours to 10-40 MicroM ferrous or ferric chloride induced a concentration-dependent death of retinal neurons but not of photoreceptors or astrocytes. An antioxidant, trolox effectively attenuated the iron-induced death of neurons and photoreceptors in a dose-dependent manner whereas neither glutamate receptor antagonists nor cycloheximide were protective. Of retinal interneurons, GABAergic neurons were more vulnerable to the iron toxicity than calbindin (+) horizontal neurons. These findings show that iron exposure induces anti-oxidant-sensitive neuronal injury in retinal culture, independent of the excitotoxic or the apoptotic mechanisms. Of retinal neurons, different cell types exhibit differential vulnerabilities to the iron-induced oxidative injury. This simplified culture model system may be useful in elucidating mechanisms of oxidative injury in the retina.

The effects of solutes on the freezing properties of and hydration forces in lipid lamellar phases

Quantitative deuterium nuclear magnetic resonance is used to study the freezing behavior of the water in phosphatidylcholine lamellar phases, and the effect upon it of dimethylsulfoxide (DMSO), sorbitol, sucrose, and trehalose. When sufficient solute is present, an isotropic phase of concentrated aqueous solution may coexist with the lamellar phase at freezing temperatures. We determine the composition of both unfrozen phases as a function of temperature by using the intensity of the calibrated free induction decay signal (FID). The presence of DMSO or sorbitol increases the hydration of the lamellar phase at all freezing temperatures studied, and the size of the increase in hydration is comparable to that expected from their purely osmotic effect. Sucrose and trehalose increase the hydration of the lamellar phase, but, at concentrations of several molal, the increase is less than that which their purely osmotic effect would be expected to produce. A possible explanation is that very high volume fractions of sucrose and trehalose disrupt the water structure and thus reduce the repulsive hydration interaction between membranes. Because of their osmotic effect, all of the solutes studied reduced the intramembrane mechanical stresses produced in lamellar phases by freezing. Sucrose and trehalose at high concentrations produce a greater reduction than do the other solutes.

Development and progression of diabetic retinopathy in Koreans with NIDDM

OBJECTIVE

To determine the incidence and risk factors for the development and progression of diabetic retinopathy in Korean patients with NIDDM.

RESEARCH DESIGN AND METHODS

A total of 186 patients with NIDDM who did not have proliferative diabetic retinopathy (PDR) at baseline were prospectively studied for 5.3 +/- 1.0 years in an outpatient clinic of a university hospital. The incidence and progression of diabetic retinopathy was determined by annual funduscopic examination by an ophthalmologist.

RESULTS

Of the 130 patients who were free of diabetic retinopathy at baseline, 30 developed it, giving an incidence of 44.4/1,000 person-years. Age and known duration of diabetes, mean fasting plasma glucose, and HbA1 levels during the follow-up period were higher in the patients who developed diabetic retinopathy. Of the 56 patients who had nonproliferative diabetic retinopathy at baseline, 11 developed PDR, giving an incidence of 37.5/1,000 person-years. The patients who progressed to PDR during follow-up (progressors) had a higher change of BMI and urinary albumin excretion rate at baseline and a higher mean HbA1 during the follow-up period than the nonprogressors. Cox proportional hazards analysis revealed that mean HbA1 was the only independent risk factor for both the development and progression of diabetic retinopathy.

CONCLUSIONS

The incidence of PDR in Korean NIDDM patients is comparable to that reported in other populations. Poor glycemic control is the most important risk factor for both the development and progression of diabetic retinopathy in NIDDM patients.

Construction of a Helicobacter pylori-Escherichia coli shuttle vector for gene transfer in Helicobacter pylori

In this study, a Helicobacter pylori-Escherichia coli shuttle vector was constructed for transferring DNA into H. pylori. The smallest cryptic plasmid (1.2 kb), pHP489, among those harbored by 77 H. pylori isolates was selected as a base replicon for constructing vectors. HindIII-digested pHP489 was ligated with a kanamycin resistance gene [aph(3')-III], which originated from Campylobacter jejuni, to produce the recombinant plasmid pHP489K. pHP489K was efficiently transformed into and stably maintained in H. pylori strains. The shuttle vector pBHP489K (3.6 kb) was constructed by the recombination of pHP489, ColE1, and aph(3')-III sequences. pBHP489K was reciprocally transformed into and maintained in both H. pylori and E. coli. Introduction of the shuttle vector clone DNA (pBHP489K/AB; 6.7 kb), containing the ureA and ureB genes of H. pylori, into urease-negative mutants of H. pylori led to the restoration of their urease activity. The transformants were confirmed to contain the incoming plasmid DNA. pBHP489K satisfied the requirements for an H. pylori-E. coli shuttle vector, implying that it might be a useful vector for investigating pathogenicity and restriction-modification systems of H. pylori.