Prediction model for pheochromocytoma/paraganglioma using nCounter assay

BACKGROUND

World Health Organization defined pheochromocytomas/paragangliomas (PPGL) as malignant tumors in 2017 because the existing classification system could not reflect locally aggressive behavior sufficiently. However, predicting the likelihood of metastasis remains a crucial part of the treatment strategy.

METHODS

From one tertiary care hospital and one secondary hospital, 97 PPGL cases were selected. Medical records of PPGL cases with the presence of formalin-fixed and paraffin-embedded (FFPE) tissue of primary lesion were reviewed. For FFPE tissues, a nCounter assay was conducted to determine differently expressed genes between metastatic and non-metastatic PPGL groups. Performances of prediction models for the likelihood of metastasis were calculated.

RESULTS

Of a total of 97 PPGL cases, 39, 20, and 38 were classified as benign, malignant, and validation, respectively. In the nCounter assay, CDK1, TYMS, and TOP2A genes showed significant differences in expression. Tumor size was positively correlated with CDK1 expression level. The Lasso regression model showed supreme performance of sensitivity 91.7% and specificity 95.5% when those significant factors were considered.

CONCLUSION

Machine learning of multi-modal classifiers can be used to create a prediction model for metastasis of PPGL with high sensitivity and specificity using nCounter assay. Moreover, CDK1 inhibitors could be considered for developing drug treatment.

The Risk of Venous Thromboembolism in Korean Patients with Breast Cancer: A Single-Center Experience

The relationship between cancer and venous thromboembolism (VTE) has long been described. The risk of VTE in Asian patients with breast cancer remains largely unknown. This study described the incidence and risk factors of VTE in Korean patients with breast cancer. Data were collected from a retrospective database of patients who underwent breast cancer surgery between 2011 and 2020 at a single institution. The Cox proportional-hazards model was used to identify factors associated with VTE occurrences. Among the 2246 patients with breast cancer, 48 (2.1%) developed VTE during a median follow-up period of 53 months. The average incidence of VTE was 459 per 100,000 person-years. Age ≥ 60 years, male sex, chronic kidney disease, reconstructive procedures, and stage II or higher were independent predictive factors for VTE. VTE was associated with poor disease-free survival (hazard ratio (HR), 6.140; 95% confidence interval (CI), 3.480-10.835), and overall survival (HR, 8.842; 95% CI 4.386-17.824). Most VTE events were manageable with anticoagulation; three (6.3%) patients died of VTE, despite intensive care. The incidence of VTE was significantly elevated in Korean patients with breast cancer. Since VTE has a negative effect on oncologic outcomes of breast cancer, clinicians should manage its risk throughout their lifetime.

Assessment of aortic valve area on cardiac computed tomography and doppler echocardiography: differences and clinical significance in symptomatic bicuspid aortic stenosis

Backgrounds

This study aimed to investigate the differences and clinical significance of effective orifice area (EOA) on Doppler echocardiography and geometric orifice area (GOA) on cardiac computed tomography (CT) in bicuspid aortic stenosis (AS).

Methods

One-hundred sixty-three consecutive patients (age 64±10 years, 56.4% men) with symptomatic bicuspid AS who were referred for surgery and underwent both cardiac CT and echocardiography within 3 months were studied. For the aortic valve area, GOACT was measured by multiplanar CT planimetry, and EOAEcho was calculated by continuity equation with Doppler echocardiography. The associations of GOACT and EOAEcho with the patients' symptom scale, biomarkers, and left ventricular (LV) functional variables were comprehensively analyzed.

Results

There was a significant but modest correlation between EOAEcho and GOACT (r=0.604, p<0.001). Both EOAEcho and GOACT revealed significant correlations with mean pressure gradient and peak transaortic velocity and the coefficients were higher in EOAEcho than GOACT. EOAEcho of 1.05 cm2 and GOACT of 1.25 cm2 correspond to the hemodynamic cut-off values for diagnosing severe AS. EOAEcho was well correlated with patients' symptom scale and log NT-pro BNP, but GOACT was not. In addition, EOAEcho showed higher correlation coefficient with estimated LV filling pressure and LV global longitudinal strain than GOACT.

Conclusions

Both EOAEcho and GOACT can be used to evaluate the severity of bicuspid AS, however, the threshold for GOACT for diagnosing severe AS should be applied higher than that for EOAEcho. EOAEcho tends to be more correlated with the patients' symptom degree, biomarkers, and LV functional variables than GOACT.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Korean Cardiac Research Foundation

Analyses of the association between breast cancer and osteoporosis/fracture history: a cross-sectional study using KoGES HEXA data

We performed a nationwide, population-based cohort study to evaluate the risk of osteoporosis and osteoporotic fracture in patients with breast cancer using the data from Korean Genome and Epidemiology Study (KoGES) and concluded that Korean women with breast cancer had a higher risk of osteoporosis than healthy women, regardless of age.

PURPOSE

This study aimed to evaluate the association between breast cancer and the occurrence of osteoporosis and osteoporotic fracture using data from the Korean Genome and Epidemiology Study (KoGES).

METHODS

Using the national KoGES health examinee (HEXA) data consisting of data from urban resident participants ≥ 40 years old, we extracted data for patients with breast cancer (n = 1080) and for control participants (n = 106,993); we then analyzed the occurrence of osteoporosis and osteoporotic fracture at baseline from 2004 to 2013 and during follow-up from 2012 to 2016. A logistic regression model was used to analyze the odds ratios (ORs) and the 95% confidence intervals (CIs). Subgroup analysis was performed based on age (younger group aged ≤ 51 years old; older group aged ≥ 52 years old).

RESULTS

The ORs (95% CIs) for osteoporosis and osteoporotic fracture were 1.54 (95% CI = 1.28-1.84, P < 0.001) and 1.01 (95% CI = 0.82-1.23, P = 0.949), respectively, in the breast cancer group. In the subgroup analysis based on age, the ORs (95% CIs) for osteoporosis were 2.41 (95% CI = 1.70-3.43, P < 0.001) in the younger group and 1.33 (95% CI = 1.08-1.64, P = 0.007) in the older group of breast cancer patients. The ORs (95% CIs) for osteoporotic fracture were 1.15 (95% CI = 0.81-1.63, P = 0.441) in the younger group and 0.95 (95% CI = 0.74-1.21, P = 0.661) in the older group of breast cancer patients.

CONCLUSION

We concluded that Korean women with breast cancer had a higher risk of osteoporosis than healthy women, but the same finding was not observed for osteoporotic fracture, regardless of age.

A Multicenter, Randomized, Controlled Trial for Assessing the Usefulness of Suppressing Thyroid Stimulating Hormone Target Levels after Thyroid Lobectomy in Low to Intermediate Risk Thyroid Cancer Patients (MASTER): A Study Protocol

BACKGROUND

Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy.

METHODS

This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years.

CONCLUSION

The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Clinicopathological Characteristics and Recurrence-Free Survival of Rare Variants of Papillary Thyroid Carcinomas in Korea: A Retrospective Study

BACKGROUND

We aimed to evaluate the clinicopathological features and biological behaviors of Korean thyroid cancer patients with rare variants of papillary thyroid carcinoma (PTC) to address the ambiguity regarding the prognostic consequences of these variants.

METHODS

We retrospectively reviewed the medical records of 5,496 patients who underwent thyroid surgery for PTC, between January and December 2012, in nine tertiary hospitals. Rare PTC variants included tall cell (TCV), columnar cell (CCV), diffuse sclerosing (DSV), cribriform-morular (CMV), solid (SV), hobnail, and Warthin-like variants. Recurrence-free survival (RFS) was defined as the time from the date of thyroidectomy until recurrence.

RESULTS

Rare variants accounted for 1.1% (n=63) of the PTC patients; with 0.9% TCV, 0.02% CCV, 0.1% DSV, 0.1% CMV, and 0.1% SV. The mean age of patients and primary tumor size were 42.1±13.1 years and 1.3±0.9 cm, respectively. Extrathyroidal extension and cervical lymph node metastasis were observed in 38 (60.3%) and 37 (58.7%) patients, respectively. Ultrasonographic findings revealed typical malignant features in most cases. During a median follow-up of 7 years, 6.3% of patients experienced a locoregional recurrence. The 5-year RFS rates were 71.4% in patients with DSV or SV, 95.9% for TCV, or CCV, and 100% for other variants. DSV emerged an independent risk factor associated with shorter RFS.

CONCLUSION

In this multicenter Korean cohort, rare variants accounted for 1.1% of all PTC cases, with TCV being the most frequent subtype. DSV emerged as a significant prognostic factor for RFS.

Does Thyroidectomy Impact Quality of Life: Retrospective Case-Control Study of Post-Thyroidectomy Patients and Matched Individuals from the General Population

Background and objectives: The study assesses quality of life (QoL) in patients who underwent thyroidectomy compared to the general population. Materials and Methods: QoL data from post-thyroidectomy patients and individuals with no subjective health concerns, who had attended a routine health screening visit, were evaluated. QoL was assessed using the modified version of Korean Short Form 12 questionnaire (SF-12). Patients and controls were matched using the propensity score approach and a ratio of 1:4. Results: Data from a total of 105 patients and 420 controls were analyzed. For five SF-12 items, lower QoL was found in patients (p < 0.05). Multivariate analysis revealed that a follow-up duration of <1-year, female sex, and an age of >50 years were independent risk factors. No significant difference was found between controls and patients who were >1-year post-surgery. Conclusions: For specific SF-12 items, QoL was lower in post-thyroidectomy patients than in controls. No intergroup difference in QoL was found >1-year post-surgery.

Automated Breast Cancer Detection in Digital Mammograms of Various Densities via Deep Learning

Mammography plays an important role in screening breast cancer among females, and artificial intelligence has enabled the automated detection of diseases on medical images. This study aimed to develop a deep learning model detecting breast cancer in digital mammograms of various densities and to evaluate the model performance compared to previous studies. From 1501 subjects who underwent digital mammography between February 2007 and May 2015, craniocaudal and mediolateral view mammograms were included and concatenated for each breast, ultimately producing 3002 merged images. Two convolutional neural networks were trained to detect any malignant lesion on the merged images. The performances were tested using 301 merged images from 284 subjects and compared to a meta-analysis including 12 previous deep learning studies. The mean area under the receiver-operating characteristic curve (AUC) for detecting breast cancer in each merged mammogram was 0.952 ± 0.005 by DenseNet-169 and 0.954 ± 0.020 by EfficientNet-B5, respectively. The performance for malignancy detection decreased as breast density increased (density A, mean AUC = 0.984 vs. density D, mean AUC = 0.902 by DenseNet-169). When patients’ age was used as a covariate for malignancy detection, the performance showed little change (mean AUC, 0.953 ± 0.005). The mean sensitivity and specificity of the DenseNet-169 (87 and 88%, respectively) surpassed the mean values (81 and 82%, respectively) obtained in a meta-analysis. Deep learning would work efficiently in screening breast cancer in digital mammograms of various densities, which could be maximized in breasts with lower parenchyma density.

Strategy to reduce unnecessary surgeries in thyroid nodules with cytology of Bethesda category III (AUS/FLUS): a retrospective analysis of 667 patients diagnosed by surgery

PURPOSE

Fine-needle aspiration (FNA) is widely used for the diagnosis of thyroid nodules detected by ultrasonography. However, the cytology of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) often leads to unnecessary thyroid surgery. This study aimed to identify a strategy to reduce unnecessary surgeries in patients with AUS/FLUS nodules.

METHODS

Medical records of 667 patients with the cytology of AUS/FLUS who underwent surgery from January 2007 to December 2017 were retrospectively reviewed. Clinicopathological data were analyzed to identify malignant factors in thyroid nodules with AUS/FLUS. Factors were compared between patients with thyroid cancer and those with benign thyroid nodules, using stepwise multivariate logistic regression and decision tree model.

RESULTS

Pathological thyroid cancer was identified in 193 (43.3%) patients. There was a significant difference in malignancy incidence with respect to family history, number of nodules, number of FNAs, ultrasonographic finding, lymphocytic thyroiditis, and BRAFV600E mutation. Multivariate analysis showed that ultrasonography (K-TIRADS 5) was the most influential independent predictor of malignancy in AUS/FLUS (odds ratio = 11.02, p < 0.001), followed by possessing BRAFV600E mutation (odds ratio = 4.54, p < 0.001). This strategy enabled 226 (89.3%) patients to avoid unnecessary surgeries based on the decision tree model. There was no node of repeated FNA in the decision tree model, which reduced the risk of malignancy (odds ratio = 0.35, p = 0.029).

CONCLUSION

K-TIRADS 5 and BRAFV600E mutation were predictive of malignancy in nodules of AUS/FLUS. These factors should be considered in strategies to reduce unnecessary surgeries for AUS/FLUS.

Extrapleural solitary fibrous tumor of the thyroid gland: A case report and review of literature

BACKGROUND

Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm that arises from the pleura. A few SFTs have also been described in extrapleural sites. However, SFT of the thyroid gland is rare. Here, we report a case of extrapleural SFT on the thyroid gland, in addition to a literature review.

CASE SUMMARY

A 59-year-old man visited our hospital in July 2017 complaining of a large mass in his neck. His thyroid function test results, including antibody levels, were within the normal limits. Ultrasonography showed a 4.7 cm × 4.0 cm × 3.2 cm solitary mass of intermediate suspicion in the left thyroid lobe. A fine-needle aspiration biopsy was subsequently performed. The pathologist reported a benign follicular lesion. However, the size of this nodule increased to 5.5 cm × 5.0 cm × 3.4 cm by April 2018. After a multidisciplinary discussion, a left lobectomy was performed in May 2018. The specimen showed a well-demarcated, partly encapsulated, soft nodule of whitish and tan/brown color on the cut surface. Light microscopy revealed high cellularity with moderate cytologic atypia. The mitotic count was 5/10 high-power fields. There was no tumor necrosis or lymphovascular invasion. The tumor was CD34-positive and signal transducer and activator of transcription 6-positive. Neither thyroid transcription factor-1 nor cytokeratin expression was detected. The Ki-67 showed intermediate proliferative activity. The final diagnosis was extrapleural SFT of the thyroid gland with a clear resection margin. The patient was discharged without complication three days after the surgery.

CONCLUSION

In the literature, extrapleural SFT of the thyroid gland has been reported to behave indolently with the capacity for recurrence and rare metastasis, although surgical resection is the treatment of choice. Understanding this disease entity is important for accurate diagnosis and proper management.

A Novel Technique for Performing Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA): A Single-port Platform

During transoral endoscopic thyroidectomy vestibular approach (TOETVA), the mental nerve can be injured by the lateral ports. Mental nerve injury is a worrisome complication, which can be minimized by using the single-port platform. A 56-year-old woman was diagnosed with a 5-mm sized papillary thyroid carcinoma on the isthmus. A horizontal 21-mm incision was made on the mucosa at the lower lip, followed by vertical dissection from the mentalis muscles down to the mandibular area. Subsequent hydrodissection widened the working space. For the single-port procedure, the KeyPort system was applied. After inserting the endoscopic instruments, the thyroid isthmus was resected as usual. The patient was discharged without any complications. To our knowledge, this is the first report of single-port TOETVA. Although the indications are limited, a single-port platform can be utilized for TOETVA. This will minimize the risk of mental nerve injury.

Retrograde installation of percutaneous transhepatic negative-pressure biliary drainage stabilizes pancreaticojejunostomy after pancreaticoduodenectomy: a retrospective cohort study

BACKGROUND

Leakage from the pancreatoenteric anastomosis has been one of the major complications of pancreaticoduodenectomy (PD). The aim of this study was to investigate the feasibility of retrograde installation of percutaneous transhepatic negative-pressure biliary drainage (RPTNBD), as part of which the drainage tube is intraoperatively inserted into the bile duct and afferent loop by surgical guidance to reduce pancreaticoenteric leakage after PD.

METHODS

We retrospectively reviewed the medical records of the patients who underwent pylorus-preserving PD or Whipple's operation for a malignant disease between June 2012 and August 2016. We performed intraoperative RPTNBD to decompress the biliopancreatic limb in all patients and compared their clinical outcomes with those of internal controls.

RESULTS

Twenty-one patients were enrolled in this study. The operation time was 412.0 ± 92.8 min (range, 240-600 min). The duration of postoperative hospital stay was 39.4 ± 26.4 days (range, 13-105 days). Ten patients (47.6%) experienced morbidities of Clavien-Dindo grade > II, and 2 patients (9.5%) experienced pancreaticojejunostomy-related complications. The internal controls showed a higher incidence rate of pancreaticojejunostomy-related complications than the study participants (P = 0.020). Mortality occurred only in the internal controls.

CONCLUSION

For stabilizing the pancreaticoenteric anastomosis after PD for a malignant disease, RPTNBD is a feasible and effective procedure. When PD is combined with technically demanding procedures, including hepatectomy or vascular reconstruction, RPTNBD could prevent fulminant anastomotic failure.

Biocompatibility of n-butyl-2-cyanoacrylate (Histoacryl) in cervical structures of rats: prospective in vivo study

Purpose

We investigated the biocompatibility of n-butyl-2-cyanoacrylate (NBCA) in the cervical deep tissues of rats to assess its biocompatibility.

Methods

A total of 30 Sprague-Dawley rats were injected with NBCA. After 30, 90, 180, and 360 days, cubes of tissue (1 cm × 1 cm × 1 cm) surrounding the NBCA and normal tissue from the other side of the neck were excised from each rat. The adhesion of NBCA to adjacent structures was examined histologically. Cells were counted per high-power field (HPF), and fibrosis was graded with the measurement of fibrotic thickening.

Results

All animals displayed normal behavior without any symptoms of distress throughout the study. There was no recognizable inflammatory reaction, foreign body reaction, or fibrosis in the 30 control samples. The analyses of experimental samples showed significantly decreased inflammatory cell counts over time (lymphoplasma cell count decreased from 100 (range, 70–100) to 30 (range, 30–50) per HPF, P = 0.010; neutrophil count decreased from 2 (range, 2–30) to 0 (range, 0–2) per HPF, P = 0.017). However, there was no significant difference in the number of multinuclear giant cells throughout the study period (a decrease from 22 [range, 16–34] to 16 [range, 12–22] per HPF, P = 0.287). The level of fibrosis was Common Toxicity Criteria ver. 4.0 Grade 1 without further thickening (P = 0.600). However, maturation of fibrosis progressed gradually.

Conclusion

NBCA was biologically tolerable in the cervical deep tissues of rats. However, precautions are needed with respect to preventing a sustained foreign body reaction and fibrosis.

Transcriptome Analysis Reveals Significant Differences in Gene Expression of Malignant Pheochromocytoma or Paraganglioma

Prediction of malignant behavior of pheochromocytoma (PC) or paraganglioma (PG) is of limited value. The Cancer Genome Atlas (TCGA) and the French 'Cortico et Médullosurrénale: les Tumeurs Endocrines' (COMETE) network in Paris (France) facilitate accurate differentiation of malignant PC/PG based on genetic information. Therefore, the objective of this transcriptome analysis is to identify the prognostic genes underlying the differentiation of malignant PC/PG in the TCGA and COMETE databases. TCGA carries data pertaining to multigenomic analysis of 173 PC/PG surgical resection samples while the COMETE cohort contains data involving 188 PC/PG surgical resection samples. Clinical information and mRNA expression datasets were downloaded from TCGA and COMETE databases. Based on eligibility criteria, 58 of 173 PC/PG samples in TCGA and 171 of 188 PC/PG samples collected by the COMETE network were selected. Using Ingenuity Pathway Analysis, the mRNA expression of malignant and benign PC/PG was compared. The 58 samples in TCGA included 11 malignant and 47 benign cases. Among the 171 samples obtained from the COMETE cohort, 19 were malignant and 152 were benign. A comparative analysis of the mRNA expression data of the two databases revealed that 11 up/downregulated pathways involved in malignant PC/PG were related to cancer signaling, metabolic alteration, and prominent mitosis, whereas 6 upregulated genes and 1 downregulated gene were significantly enriched in the functional annotation pathways. The TCGA and COMETE databases showed differences in mRNA expression associated with malignant and benign PC/PG. Improved recognition of prognostic genes facilitates the diagnosis and treatment of PC/PG.

Thoracic recurrence in patients with curatively-resected colorectal cancer: incidence, risk factors, and value of chest CT as a postoperative surveillance tool

OBJECTIVE

To investigate the incidence of thoracic recurrence and the diagnostic value of chest CT for postoperative surveillance in curatively-resected colorectal cancer (CRC) patients.

METHODS

This retrospective study consisted of 648 CRC patients (M:F, 393:255; mean age, 66.2 years) treated with curative surgery between January 2010 and December 2012. The presence of CRC recurrence over follow-ups was analysed and recurrence-free survival and risk factors of recurrence were assessed using Kaplan-Meier analysis with log-rank test and Cox-regression analysis, respectively.

RESULTS

Over a median follow-up of 57 months, thoracic recurrence occurred in 8.0% (52/648) of patients with a median recurrence-free survival rate of 19.5 months. Among the 52 patients with thoracic recurrence, 18 (2.7%) had isolated thoracic recurrence, and only five (0.8%) were diagnosed through chest CT. Risk factors of overall thoracic recurrence included age, positive resection margin, presence of venous invasion, positive pathologic N-class, and presence of abdominal recurrence (odds ratio [OR] = 1.78, 19.691, 2.993, 2.502, and 31.137; p = 0.045, 0.004, 0.001, 0.005, and p < 0.001, respectively). As for isolated thoracic recurrence, serum carcinoembryonic antigen level ≥ 5 ng/mL during postoperative follow-up (OR = 9.112; p < 0.001) was demonstrated to be the only predictive factor. There were no thoracic recurrences in patients with CRC stages 0 and I.

CONCLUSION

In patients with curatively-resected CRCs, routine surveillance using chest CT may be of limited value, particularly in those with CRC stages 0 or I, as recurrence only detectable through chest CT was shown to be rare.

KEY POINTS

• Postoperative thoracic recurrence only detectable through chest CT was shown to be rare. • There were no thoracic recurrences in colorectal cancers stage 0 and I. • Postoperative surveillance chest CT is of limited value in patients with curatively resected colorectal cancers.

Safety of medial dissection of the thyroid gland along the trachea based on anatomic constancy of the laryngeal entry point of the recurrent laryngeal nerve

Purpose

The purpose of this study was to determine the extent of safety of medial dissection of the thyroid gland along the trachea. Medial to lateral dissection of the thyroid gland along the trachea after early division of the isthmus has been known to be a useful technique in thyroid surgery, especially for difficult cases, but the risk of injury of the recurrent laryngeal nerve (RLN) has constrained thyroid surgeons from utilizing this technique to its full extent.

Methods

Distances of the laryngeal entry point (LEP) of 134 RLNs of 71 patients from the midline of the trachea, and some other anatomical distances, were measured intraoperatively. The relationships of the intraoperatively measured data with circumferences of the cartilaginous portion of the trachea (CCT) around LEP measured preoperatively by CT scan were evaluated.

Results

LEP was always located within 2 mm vertically from the horizontally extended line of the inferior border of the cricoid cartilage and was the closest point from the midline in the whole course of the RLN. The distance between LEP and the midline was very closely correlated with CCT measured on preoperative CT scan, and it can be accurately calculated with a regression equation; Distance between LEP and the midline = (0.42 × CCT) + (1.2 × sex) + 3.2 (mm) (sex: female=0, male=1; R² = 0.85).

Conclusion

Early division of the isthmus and dissecting the thyroid off the trachea to the calculated extent is a safe and effective procedure.

Malignancy in Pheochromocytoma or Paraganglioma: Integrative Analysis of 176 Cases in TCGA

Methods of diagnosing malignant pheochromocytoma (PCC) or paraganglioma (PGL) are needed. However, there are no reliable histopathologic criteria to distinguish malignant PCC/PGLs. The recent genomic analysis of The Cancer Genome Atlas (TCGA) provides in-depth information enabling more accurate diagnosis of disease entities. Therefore, we investigated genomic expression differences and mutational differences of malignant PCC/PGLs with TCGA. As of December 2014, TCGA had acquired multigenomic analysis of 176 PCC/PGL samples. Clinical information, mutation status, and 20,531 gene messenger RNA (mRNA) expression dataset of normalized RNA-sequencing mRNA read counts were downloaded from TCGA, and integrated into a table. Of the 176 PCC/PGL samples in the dataset, 14 had metastasis and 162 exhibited no metastasis. mRNA expression and mutations were compared in these two groups. There were 76 males in the dataset of 176 TCGA samples. Mean age was 47.6 ± 15.2 years (19-83 years). There was no significant gender or race difference between metastatic and non-metastatic groups. mRNA expression of malignant PCC/PGLs was upregulated in five pathways of cell cycle (BUB1, BUB1B, CCNB2, CDC2, ESPL1), calcium signaling (CCNB2, CDC2, PRKCB1), regulation of actin cytoskeleton (DIAPH3, FGF18, IQGAP3), gap junction (CDC2, PRKCB1), and phosphatidylinositol (PRKCB1, TTK). Disease-free survival rates were significantly correlated with the presence or absence of mutations, such as RP11-798G7.5, HERC2, SETD2, TGDS, TRHDE, FKBP9, and BMS1. TCGA showed differences in mRNA expression and mutations between metastatic and non-metastatic PCC/PGLs. The improved recognition of genetic causes can help to achieve proper diagnosis and provide appropriate treatment of PCC/PGL.

Preoperative flap-site injection with ropivacaine and epinephrine in BABA robotic and endoscopic thyroidectomy safely reduces postoperative pain: A CONSORT-compliant double-blinded randomized controlled study (PAIN-BREKOR trial)

BACKGROUND

Clinical trials on bilateral axillo-breast approach (BABA) thyroidectomy show that levobupivacaine and ropivacaine significantly reduce postoperative pain, but they focused on BABA robotic thyroidectomy only and did not identify specific sites of significant pain relief. Our objective was to assess the pain reduction at various sites and safety of ropivacaine-epinephrine flap injection in BABA thyroidectomy.

METHODS

This prospective double-blinded randomized controlled trial was conducted in compliance with the revised CONSORT statement (ClinicalTrials.gov registration no. NCT02112370). Patients were randomized into the ropivacaine-epinephrine arm or control (normal saline) arm.

RESULTS

From January 2014 to May 2016, 148 patients participated. The primary endpoint was site-specific pain, as measured by numeric rating scale 12 hours after surgery. The ropivacaine-epinephrine group exhibited significantly less swallowing difficulty (P = .008), anterior neck pain (P = .016), and right (P = .019) and left (P = .035) chest pain. Secondary endpoints were systolic (P = .402), diastolic (P = .827) blood pressure, and pulse rate (P = .397) after injection before incision and during surgery. The vital signs of the groups just after injection did not differ. During surgery, the ropivacaine-epinephrine patients had higher pulse rates (99 ± 13.3 vs 88 ± 16.1, P < .001) but within normal range. There were no adverse events such as postoperative nausea and vomiting. There was no significant difference in pain scores in either patient group between patients who underwent robotic or endoscopic interventions.

CONCLUSION

BABA flap-site injection with ropivacaine and epinephrine mix before incision effectively and safely reduced postoperative pain. Future studies should focus on tailoring ropivacaine and epinephrine dosage for individuals.

Missing the target: including perspectives of women with overweight and obesity to inform stigma-reduction strategies

OBJECTIVE

Pervasive weight stigma and discrimination have led to ongoing calls for efforts to reduce this bias. Despite increasing research on stigma-reduction strategies, perspectives of individuals who have experienced weight stigma have rarely been included to inform this research. The present study conducted a systematic examination of women with high body weight to assess their perspectives about a broad range of strategies to reduce weight-based stigma.

METHODS

Women with overweight or obesity (N = 461) completed an online survey in which they evaluated the importance, feasibility and potential impact of 35 stigma-reduction strategies in diverse settings. Participants (91.5% who reported experiencing weight stigma) also completed self-report measures assessing experienced and internalized weight stigma.

RESULTS

Most participants assigned high importance to all stigma-reduction strategies, with school-based and healthcare approaches accruing the highest ratings. Adding weight stigma to existing anti-harassment workplace training was rated as the most impactful and feasible strategy. The family environment was viewed as an important intervention target, regardless of participants' experienced or internalized stigma.

CONCLUSION

These findings underscore the importance of including people with stigmatized identities in stigma-reduction research; their insights provide a necessary and valuable contribution that can inform ways to reduce weight-based inequities and prioritize such efforts.

BRAF(V600E) Is Correlated with Recurrence of Papillary Thyroid Microcarcinoma: A Systematic Review, Multi-Institutional Primary Data Analysis, and Meta-Analysis

BACKGROUND

Given the increasing incidence of papillary thyroid carcinoma despite stable disease-specific mortality rates, the potential for the disease to reoccur is a key outcome to predict. The BRAF(V600E) mutation has been associated with recurrent disease in larger tumors. However, its correlation in papillary thyroid microcarcinoma (PTMC) is not clear in individual series.

METHODS

The MEDLINE, EMBASE, Web of Science, and Cochrane databases were searched for studies including patients with PTMC undergoing initial surgical treatment. Studies with at least two years of follow-up, BRAF genotyping (the comparator), and recurrence as an outcome were included, as were unpublished primary data on 485 patients from two institutions. The metameter analyzed was odds ratio (OR) for recurrence between patients with BRAF(V600E) versus BRAF wild type (BRAFwt).

RESULTS

The initial search identified 431 references. After screening of the abstracts for inclusion, 44 manuscripts were reviewed in full by two independent reviewers. Four published studies and primary data from two institutional cohorts were included in the final analysis. A meta-analysis of 2247 PTMC patients revealed that patients with a BRAF(V600E) mutation had a higher likelihood for recurrence (odds ratio 2.09 [confidence interval 1.31-3.33], p = 0.002).

CONCLUSIONS

This meta-analysis shows that BRAF mutational status correlates with recurrence of PTMCs, highlighting the potential utility of genotyping in preoperative and postoperative planning. BRAF mutation may be helpful in risk-stratifying patients with PTMC for surgical management versus observation.

Comparison of 4D CT, ultrasonography, and 99mTc sestamibi SPECT/CT in localizing single-gland primary hyperparathyroidism

OBJECTIVE

The present study was designed to evaluate 4D computerized tomography (CT) as a means of localizing abnormal parathyroid glands in primary hyperparathyroidism (HPT).

STUDY DESIGN

Case series with expertized image review.

SETTING

Tertiary care hospital.

SUBJECTS AND METHODS

A total of 38 patients were recruited for study, all of whom had undergone focused parathyroidectomy for single-lesion primary HPT between June 2011 and September 2013. In each patient, 3 imaging procedures were performed: cervical ultrasonography (US), 99mTc-sestamibi SPECT/CT (SeS), and 4D CT. Collective imaging data were blindly reviewed and compared.

RESULTS

4D CT outperformed US and SeS in terms of sensitivity (P=.27), specificity (P=.01), positive predictive value (PPV) (P<.01), negative predictive value (NPV) (P=.19), and accuracy (P<.01). In 7.9% (3/38) of patients, 4D CT provided specific anatomic information that was unaffordable by US and SeS. Localization by 4D CT correlated with tissue parathyroid hormone level (P=.02), maximum diameter (P=.01), and volume (P<.01) of abnormal parathyroid glands.

CONCLUSION

4D CT proved helpful in localizing target parathyroid glands of primary HPT that were missed by traditional imaging.

Indocyanine green as a near-infrared fluorescent agent for identifying parathyroid glands during thyroid surgery in dogs

BACKGROUND

Surgical procedures involving the thyroid gland require identification of the parathyroid glands. Indocyanine green (ICG) is a near-infrared (NIR) fluorescent contrast agent used for a variety of procedures such as intraoperative angiography, extrahepatic cholangiography, and lymph node mapping. In this study, we used a canine model to evaluate ICG for NIR fluorescent imaging of the parathyroid gland.

METHODS

Three dogs were used for the study. The dogs were administered general anesthesia, and after surgical dissection, each dog received a series of intravenous ICG doses ranging from 12.5 to 100 µg/kg ICG. The excitation light source used to illuminate the operating field was a NIR laser (λ = 785 nm). Intravascular ICG fluorescence (λ = 835/45 nm) was recorded using a charge-coupled device that employed optical filtering to block ambient and laser light. Fluorescent imaging was assessed after injection of each dose of ICG.

RESULTS

NIR fluorescent imaging visualized the parathyroid glands. The intensity curves showing the peak and plateau of fluorescence are similar regardless of the concentration of ICG. The time to peak fluorescent intensity was 50.2 ± 2.0 s after injection of ICG. Taking into consideration background fluorescent intensity, the estimated optimal dose of ICG was 18.75 µg/kg. At 106.7 ± 5.8 s, the parathyroid glands lost much of their fluorescence, although they remained sufficiently fluorescent to be distinguishable. There was a positive correlation of fluorescent intensity with ICG dose escalation up to 25 µg/kg.

CONCLUSIONS

ICG NIR fluorescent imaging was useful in detecting the parathyroid glands of dogs. By allowing detection of parathyroid glands, the current technique shows promise for use by endocrine surgeons performing thyroidectomies.

A beneficial effect of purse-string skin closure after ileostomy takedown: a retrospective cohort study

OBJECTIVES

The aim of this study was to investigate the clinical benefits of purse-string skin closure (PS) in daily practice compared with conventional linear skin closure (CL) after ileostomy takedown in Korean population.

METHODS

These retrospectively collected data were based on 157 consecutive patients who underwent ileostomy takedown between November 2010 and September 2011. Before March, 2011, CL was performed in 79 patients. Thereafter, PS was performed in 78 patients. The medical records including pain score recorded daily were reviewed and the postoperative outcomes, including SSI, were analyzed.

RESULTS

PS group had a significantly lower overall complication rate than the CL group (8.97% vs. 25.32%, p = 0.010). Among complications, PS group had a significantly lower SSI rate than the CL group (0% vs. 11.39%, p = 0.003). After adjusted for other risk factors (smoking, body mass index, anastomosis method), PS method was associated significantly and independently with a lower SSI rate than CL method (adjusted odds ratio: 26.63, 95% confidence interval: 3.02-267.70, p = 0.001). And the two groups did not differ in terms of postoperative pain (p = 0.323) or pain pattern (p = 0.548).

CONCLUSION

In daily practice, PS had a beneficial effect on SSI in patients who underwent ileostomy takedown in the Korean population.

Rectal perforation caused by anal stricture after hemorrhoid treatment

Inappropriate therapies for hemorrhoids can lead to various complications including anorectal stricture. We report a patient presenting with catastrophic rectal perforation due to severe anal stricture after inappropriate hemorrhoid treatment. A 67-years old man with perianal pain visited the emergency room. The hemorrhoids accompanied by constipation, had tortured him since his youth. Thus he had undergone injection sclerotherapy several times by an unlicensed therapist and hemorrhoidectomy twice at the clinics of private practitioners. His body temperature was as high as 38.5℃. The computed tomographic scan showed a focal perforation of posterior rectal wall. The emergency operation was performed. The fibrotic tissues of the anal canal were excised. And then a sigmoid loop colostomy was constructed. The patient was discharged four days following the operation. This report calls attention to the enormous risk of unlicensed injection sclerotherapy and overzealous hemorrhoidectomy resulting in scarring, progressive stricture, and eventual rectal perforation.

Comparison of the underestimation rate in cases with ductal carcinoma in situ at ultrasound-guided core biopsy: 14-gauge automated core-needle biopsy vs 8- or 11-gauge vacuum-assisted biopsy

OBJECTIVE

The objective of this study was to compare the underestimation rate of invasive carcinoma in cases with ductal carcinoma in situ (DCIS) at percutaneous ultrasound-guided core biopsies of breast lesions between 14-gauge automated core-needle biopsy (ACNB) and 8- or 11-gauge vacuum-assisted biopsy (VAB), and to determine the relationship between the lesion type (mass or microcalcification on radiological findings) and the DCIS underestimation rate.

METHODS

We retrospectively reviewed imaging-guided biopsies of breast lesions performed from February 2003 to August 2008. 194 lesions were diagnosed as DCIS at ultrasound-guided core biopsy: 138 lesions in 132 patients by 14-gauge ACNB, and 56 lesions in 56 patients by 8- or 11-gauge VAB. The histological results of the core biopsy samples were correlated with surgical specimens. The clinical and radiological findings were also reviewed. The histological DCIS underestimation rates were compared between the two groups and were analysed for differences according to the clinical and radiological characteristics of the lesions.

RESULTS

The DCIS underestimation rate was 47.8% (66/138) for 14-gauge ACNB and 16.1% (9/56) for VAB (p<0.001). According to the lesion type on sonography, DCIS underestimation was 43.4% (63/145) in masses (47.6% using ACNB and 15.8% using VAB; p=0.012) and 24.5% (12/49) in microcalcifications (50.0% using ACNB and 16.2% using VAB; p=0.047).

CONCLUSION

The underestimation rate of invasive carcinoma in cases with DCIS at ultrasound-guided core biopsies was significantly higher for ACNB than for VAB. Furthermore, this difference does not change according to the lesion type on ultrasound. Therefore, ultrasound-guided VAB can be a useful method for the diagnosis of DCIS lesions presented as either mass or microcalcification.

Comparison of surgical-site infection between open and laparoscopic appendectomy

Purpose

An inflamed appendix can be removed either openly (open appendectomy [OA]) or laparoscopically (laparoscopic appendectomy [LA]). Surgical-site infection (SSI) is a representative healthcare-associated infection and can impose serious economic burdens on patients as well as affect morbidity and mortality rates. The aim of this study was to compare LA with OA in terms of SSI.

Methods

The medical records of 749 patients (420 males; mean age, 33 years) who underwent appendectomy (OA, 431; LA, 318) between September 1, 2008 and April 29, 2010 were retrospectively reviewed for demographic and pathologic characteristics, recovery of bowel movement, length of hospital stay, and postoperative complications.

Results

The frequency of purulent/gangrenous or perforated appendicitis was not significantly different between LA and OA groups (83% [263/318 cases] vs. 83% [359/431 cases], P = 0.183). The time to first flatus after surgery was not significantly different between the two groups (1.38 ± 1.07 days for LA, 1.33 ± 0.90 days for OA, P = 0.444), but the length of hospital stay was significantly shorter in LA group than in OA group (3.37 ± 0.12 days vs. 3.83 ± 0.12 days, P = 0.006). The frequency of overall SSI was not significantly different between the two groups (2.8% for LA, 4.6% for OA, P = 0.204), but that of superficial incisional SSI was significantly lower in LA group (0.6% vs. 3.9%, P = 0.016).

Conclusion

The results of this study suggest that LA may lead to a shorter length of hospital stay and may have a lower risk of superficial incisional SSI than OA.

Natural nanocontainer for the controlled delivery of glycerol as a moisturizing agent

Natural halloysite nanotubes with a 15-nm internal lumen and a 50 nm outer diameter were investigated as a nanocontainer for the loading and extended release of glycerol for cosmetic applications. Cytotoxicity testing of the halloysite was conducted on 3T3 and MCF-7 cells, and the tubules showed no toxic effect on the cells for over 48 h. The capability of halloysite for loading glycerol was higher with the USA halloysite than with the New Zealand's, being approximately 20% and 2.3% by weight, respectively. The total elapsed time for releasing glycerol from the nanotubes exceeded 20 h. To further retard the glycerol release rate, the halloysite samples filled with glycerol were coated with several alternate layers of polyethyleneimine and polyacrylic acid. The release rate remained at the same level, however, probably due to the low molecular weight of the polyelectrolytes and the high solubility of glycerol in water.

Diagnostic accuracy of mini-mental status examination and revised hasegawa dementia scale for Alzheimer's disease

To compare the diagnostic accuracies of the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental Status Examination (MMSE) for Alzheimer's diseases (AD), we administered them simultaneously to 82 AD patients and 82 age- and sex-matched nondemented control subjects. The area under the receiver operator curve (AUC) for AD of the HDS-R (AUC(HDS-R)) and MMSE (AUC(MMSE)) were bigger than 0.90 indicating that both tests are useful for detecting AD. However, AUC(HDS-R) (0.952) was significantly larger than that of the AUC(MMSE )(0.902) regardless of the educational level of the subjects, indicating that the HDS-R is more accurate than MMSE in diagnosing AD. Moreover, the superiority of the HDS-R (AUC(HDS-R) = 0.894) to the MMSE (AUC(MMSE) = 0.704) remained significant in mild AD patients alone, who are the focus of screening. In conclusion, the HDS-R is better than the MMSE as a screening instrument for AD.

Specific immunoglobulin E for staphylococcal enterotoxins in nasal polyps from patients with aspirin-intolerant asthma

BACKGROUND

Nasal polyps infiltrated with eosinophils are commonly found in chronic asthmatic patients, more frequently in those with aspirin-intolerant asthma (AIA) than aspirin-tolerant asthma (ATA). Some studies have suggested a contribution of superantigens derived from Staphylococcus sp to nasal polyposis and eosinophilia, but their relative importance in AIA and ATA subjects is unknown.

OBJECTIVE

We investigated whether local production of specific IgE to staphylococcal enterotoxins A and B (SEA and SEB) and relationships with markers of eosinophilic inflammation differ in the nasal polyps of AIA and ATA subjects.

METHODS

Fifteen AIA subjects with positive responses to lysine-aspirin bronchoprovocation and 15 ATA subjects underwent polypectomy. Immunoassays were used to quantify eosinophil cationic protein (ECP), IL-5, mast cell tryptase, soluble IL-2 receptors (sIL-2R), total IgE, and specific IgE for SEA and SEB.

RESULTS

ECP levels in nasal polyp homogenates were higher in AIA subjects than in ATA subjects (P < 0.02), with no significant differences in tryptase, IL-5 or sIL-2R. Total IgE, and specific IgE to both SEA and SEB, were detectable in some nasal polyps from both subject groups, but median levels were markedly higher in AIA subjects than in ATA subjects (P = 0.04, 0.01, 0.05, respectively). Levels of specific IgE to SEA and SEB correlated significantly with levels of ECP and IL-5, but not those of tryptase or sIL-2R.

CONCLUSION

These findings suggest that staphylococcal superantigens may drive local eosinophilic inflammation in nasal polyp tissue, and that this is exacerbated in subjects with AIA.

Application of a Bayesian method for optimal subset regression to linkage analysis of Q1 and Q2

We explore an approach that allows us to consider a trait for which we wish to determine the optimal subset of markers out of a set of p > or = 3 candidate markers being considered in a linkage analysis. The most effective analysis would find the model that only includes the q markers closest to the q major genes which determine the trait. Finding this optimal model using classical "frequentist" multiple regression techniques would require consideration of all 2p possible subsets. We apply the work of George and McCulloch [J Am Stat Assoc 88:881-9, 1993], who have developed a Bayesian approach to optimal subset selection regression, to a modification of the Haseman-Elston linkage statistic [Elston et al., Genet Epidemiol 19:1-17, 2000] in the analysis of the two quantitative traits simulated in Problem 2. The results obtained using this Bayesian method are compared to those obtained using (1) multiple regression and (2) the modified Haseman-Elston method (single variable regression analysis). We note upon doing this that for both Q1 and Q2, (1) we have extremely low power with all methods using the samples as given and have to resort to combining several simulated samples in order to have power of 50%, (2) the multivariate analysis does not have greater power than the univariate analysis for these traits, and (3) the Bayesian approach identifies the correct model more frequently than the frequentist approaches but shows no clear advantage over the multivariate approach.

Clinical and immunologic changes after allergen immunotherapy with Hop Japanese pollen

BACKGROUND AND OBJECTIVE

Hop Japanese (Hop J) pollen has been reported as one of the major causative pollen allergens in the autumn season. There have been no published data regarding the clinical and immunologic effects of Hop J pollen immunotherapy in sensitized patients. In this study, we evaluated clinical and immunologic effects of Hop J immunotherapy.

PATIENTS AND METHODS

Pollens were collected in our area, and "Depo-Hop J" was prepared in the laboratory of Allergopharma (Reinbek, Germany). Fifteen asthmatic patients who had Hop J immunotherapy for > 1 year were enrolled. Their clinical parameters, such as asthma symptom scores, were monitored. Skin reactivity to Hop J and degree of airway hyperresponsiveness to methacholine were measured before and 1 year after the immunotherapy. Sera were collected before the immunotherapy, at the end of initial therapy, and 1 year after the therapy. Serum total IgE levels were compared by radioimmunoassay. Serum-specific IgE, IgG1, and IgG4 levels to Hop J were compared by ELISA. To evaluate the changes of cellular mechanisms, soluble CD30 (sCD30), soluble interleukin (IL)-2 receptor (sIL-2R), soluble CD23 (sCD23), and IL-10 levels were measured by ELISA.

RESULTS

Specific IgG1 and IgG4 levels began to increase at the end of the initial therapy (P < 0.05) with significant decreases in symptom scores (P < 0.05), whereas total and specific IgE levels showed variable responses during the immunotherapy with no statistical significance (P > 0.05). Serum sIL-2R and sCD30 levels decreased significantly (P < 0.05) 1 year after immunotherapy. No significant changes were noted in sCD23, IL-10, skin reactivity to Hop J, or airway responsiveness to methacholine (P > 0.05).

CONCLUSIONS

We are certain that Hop J allergen immunotherapy, if carried out properly according to suitable indications, can favorably influence asthma. Thus, an increase in specific IgG4 and IgG1 antibodies and reduction of a possible Th2 lymphocyte marker (sCD30) may be associated with symptomatic improvements.

Inhibition of phospholipase D by a protein factor from bovine brain cytosol. Partial purification and characterization of the inhibition mechanism

A specific protein inhibitor of partially purified bovine brain phospholipase D (PLD) was identified from bovine brain cytosol. The PLD inhibitor has been enriched through several chromatographic steps and characterized with respect to size and mechanism of inhibition. The inhibitor showed an apparent molecular mass of 30 kDa by Superose 12 gel exclusion chromatography and inhibited PLD activity with an IC50 of 7 nM. The inhibitor had neither proteolytic activity nor phospholipid-hydrolyzing activity. Because phosphatidylinositol 4,5-bisphosphate (PIP2), which is included in substrate vesicles, is an essential cofactor for PLD, we examined whether the inhibition might be mediated by sequestration of PIP2. PIP2 hydrolysis by phospholipase C (PLC)-beta1 was not affected by the inhibitor and the inhibitor did not bind to substrate vesicles containing PIP2. In contrast, a PH domain derived from PLC-delta1, which could bind to PIP2, showed a nearly identical inhibition of both PLC-beta1 and PLD activities. Thus, the PLD inhibition by the inhibitor is due to the specific interaction with not PIP2 but PLD. The suppression of PLD activity by the inhibitor was largely eliminated by the addition of ADP-ribosylation factor (ARF) and GTPgammaS. We propose that the inhibitor plays a negative role in regulation of PLD activity by PIP2 and ARF.

Clinical implication of preoperative oral cholecystogram for laparoscopic cholecystectomy

BACKGROUND

The aim of this study was to retrospectively assess the usefulness of the preoperative oral cholecystogram (OCG) as an index to the feasibility of laparoscopic cholecystectomy (LC) and the operative pathologic findings. Laparoscopic cholecystectomy has become the standard treatment for symptomatic gallbladder (GB) disease. However, no definite diagnostic modality that can predict the feasibility of LC and severity of pathologic anatomy has been proposed.

METHODS

Retrospective data were collected on 240 consecutive patients undergoing LC at St. Vincent Hospital, Catholic University Medical College, from October 1991 until December 1993. Radiologic interpretations of OCG were standardized according to the method of Koehler and Kyaw--from grade 0 to 4. And the operative findings--pericholecystic adhesion, color of GB, and thickness of the GB wall--were evaluated simultaneously.

RESULTS

The analysis showed that preoperative OCG can predict intraoperative GB perforation (p = 0.022), intraoperative controllable bleeding (p = 0.034), and operating time (p = 0.0001) according to the grade of visualization of GB. Grade 2- or -better visualized groups had more patients who had blue-colored GB (p = 0.000) and who had thin GB wall (p = 0.000).

CONCLUSIONS

Preoperative oral cholecystogram may be an accurate index of the feasibility of laparoscopic cholecystectomy--represented by operating time and important intraoperative minor complications related to the operative pathological findings.

The axonal gamma-aminobutyric acid transporter GAT-1 is sorted to the apical membranes of polarized epithelial cells

Recent studies suggest that epithelial cells and neurons employ similar mechanisms to target proteins to the distinct subdomains of their polarized cell surface membranes. We have examined the sorting behavior of the neuronal gamma-aminobutyric acid (GABA) transporter GAT-1 expressed by transfection in the polarized epithelial Madin-Darby canine kidney (MDCK) cell line. We find that the GABA transporters endogenously expressed by polarized hippocampal neurons in culture are restricted to axonal plasma membranes. In transfected MDCK cells, the GABA transporter is found to be localized primarily to the apical cell surface when examined by immunocytochemistry, cell surface biotinylation, and transport assay. MDCK cells exposed to hyperosmotic stress express a close relative of GAT-1, the betaine transporter (BGT-1). We find that BGT-1 expressed by transfection in MDCK cells accumulates predominantly at the basolateral cell surface. These observations suggest that the sorting information required for axonal targeting may be similar to that which mediates apical localization in epithelia. Furthermore, it would appear that despite their high degree of homology, the BGT-1 and GAT-1 transporters manifest sorting signals which specify their targeting to distinct cell surface domains.

Expression of a cloned gamma-aminobutyric acid transporter in mammalian cells

The cDNA clone GAT-1, which encodes a Na(+)- and Cl(-)-coupled GABA transporter from rat brain, has been expressed in mammalian cells using three different systems: (1) transient expression upon transfection of mouse Ltk- cells with a eukaryotic expression vector containing GAT-1; (2) stable expression in L-cells transfected with the same vector; (3) transfection of HeLa cells infected with a recombinant vaccinia virus expressing T7 RNA polymerase. Similar results both qualitatively and quantitatively were obtained with all systems. The GABA transporter expressed in HeLa and L-cells retains all the properties described previously for GABA transport into synaptosomes and synaptic plasma membrane vesicles. It was fully inhibited by cis-3-aminocyclohexanecarboxylic acid (ACHC) and not by beta-alanine. The KM for GABA transport and the IC50 for ACHC inhibition were similar to the presynaptic transporter. Accumulated [3H]GABA was released from transfected cells by dissipating the transmembrane Na+ gradient with nigericin or by exchange with unlabeled external GABA. Accumulation was stimulated by both Na+ and Cl- in the external medium. However, in the absence of external Cl-, a small amount of GABA transport remained which was dependent on GAT-1 transfection. Functional expression of the GABA transporter was abolished by tunicamycin. An antitransporter antibody specifically immunoprecipitates a polypeptide with an apparent molecular mass of about 70 kDa from GAT-1-transfected cells. When cells were grown in the presence of tunicamycin, only a faint band of apparent mass of about 60 kDa was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical and transient state kinetic studies on the formation and decomposition of horseradish peroxidase compounds XI and XII

Previous studies on the chlorination reaction catalyzed by horseradish peroxidase using chlorite as the source of chlorine detected the formation of a chlorinating intermediate that was termed Compound X (Shahangian, S., and Hager, L.P. (1982) J. Biol. Chem. 257, 11529-11533). These studies indicated that at pH 10.7, the optical absorption spectrum of Compound X was similar to the spectrum of horseradish peroxidase Compound II. Compound X was shown to be quite stable at alkaline pH values. This study was undertaken to examine the relationship between the oxidation state of the iron protoporphyrin IX heme prosthetic group in Compound X and the chemistry of the halogenating intermediate. The experimental results show that the optical absorption properties and the oxidation state of the heme prosthetic group in horseradish peroxidase are not directly related to the presence of the activated chlorine atom in the intermediate. The oxyferryl porphyrin heme group in alkaline Compound X can be reduced to a ferric heme species that still retains the activated chlorine atom. Furthermore, the reaction of chlorite with horseradish peroxidase at acidic pH leads to the secondary formation of a green intermediate that has the spectral properties of horseradish peroxidase Compound I (Theorell, H. (1941) Enzymologia 10, 250-252). The green intermediate also retains the activated chlorine atom. By analogy to peroxidase Compound I chemistry, the heme prosthetic group in the green chlorinating intermediate must be an oxyferryl porphyrin pi-cation radical species (Roberts, J. E., Hoffman, B. M., Rutter, R. J., and Hager, L. P. (1981) J. Am. Chem. Soc. 103, 7654-7656). To be consistent with traditional peroxidase nomenclature, the red alkaline form of Compound X has been renamed Compound XII, and the green acidic form has been named Compound XI. The transfer of chlorine from the chlorinating intermediate to an acceptor molecule follows an electrophilic (rather than a free radical) path. A mechanism for the reaction is proposed in which the activated chlorine atom is bonded to a heteroatom on an active-site amino acid side chain. Transient state kinetic studies show that the initial intermediate, Compound XII, is formed in a very fast reaction. The second-order rate constant for the formation of Compound XII is approximately 1.1 x 10(7) M-1 s-1. The rate of formation of Compound XII is strongly pH-dependent. At pH 9, the second-order rate constant for the formation of Compound XII drops to 1.5 M-1 s-1. At acidic pH values, Compound XII undergoes a spontaneous first-order decay to yield Compound XI.(ABSTRACT TRUNCATED AT 400 WORDS)