The Long-Term Impact of 5-alpha Reductase Inhibitors on the Development of Bladder Cancer and the Need for Radical Cystectomy: A Nationwide Observational Study

PURPOSE

To investigate the long-term effects of taking 5-alpha reductase inhibitors (5ARIs) on the development of bladder cancer (BC) and the implementation of radical cystectomy (RC), a standard procedure for advanced BC.

MATERIALS AND METHODS

From the National Health Insurance Sharing Service database, males aged over 40 years who underwent serum prostate-specific antigen testing from 2006 through 2017 were identified, which is required for the prescription of 5ARIs. The association between the administration duration of 5ARIs and the practice for BC was analyzed.

RESULTS

Of the 3,843,968 subjects, 1,514,713 (39.4%) took 5ARIs for an average of 1.53 years, remaining 2,329,255 (60.6%) as non-5ARI counterparts. The incidence of BC was higher in the non-5ARI than in the 5ARI group (1.25% vs. 0.87%, p<0.001), as was the implementation rate of RC (11.1% vs. 10.4%, p=0.037). In a multivariate analysis, the non-5ARI group had a significant risk of BC (hazard ratio [HR]=2.289, 95% confidence interval [CI]=2.241-2.338) and RC (HR=2.199, 95% CI=2.061-2.348) than the 5ARI group. Among the 5ARIs group, though the incidence of BC was maintained (slope=-0.002 per year, p=0.79) after an initial increase for two years, the rate of RC decreased (slope=-1.1, p<0.001) consistently for ten years during the administration.

CONCLUSIONS

Compared to the untreated group, 5ARIs use was associated with lower rates of BC and RC. In contrast to the increase in BC seen with short-term use of less than two years, long-term use of 5ARIs decreased the rate of RC in a duration-dependent manner for ten years, suggesting a strategy to prevent disease progression.

The role of ambulatory blood pressure monitoring in enhancing medication adherence among patients with newly diagnosed hypertension: an analysis of the National Health Insurance cohort database

BACKGROUND

Improving adherence to antihypertensive medication (AHM) is a key challenge in hypertension management. This study aimed to assess the impact of ambulatory blood pressure monitoring (ABPM) on AHM adherence.

METHODS

We utilized the Korean National Health Insurance Service database. Among patients newly diagnosed with hypertension who started AHM between July 2010 and December 2013, we compared clinical characteristics and adherence between 28,116 patients who underwent ABPM prior to starting AHM and 118,594 patients who did not undergo ABPM. Good adherence was defined as a proportion of days covered (PDC) of 0.8 or higher.

RESULTS

The total study population was 146,710, with a mean age of 50.5 ± 6.4 years; 44.3% were female. Co-morbidities were noted in 4.2%. About a third of patients (33.1%) showed good adherence. The ABPM group had a notably higher PDC (total PDC: 0.64 ± 0.35 vs. 0.45 ± 0.39; P < 0.001), irrespective of the number of medications, dosing frequency, or prescription duration. After adjusting for significant clinical variables, ABPM was still closely linked with good adherence (odds ratio, 2.35; 95% confidence interval, 2.28-2.41; P < 0.001).

CONCLUSIONS

In newly diagnosed hypertension, undergoing ABPM prior to AHM prescription appears to enhance adherence to AHM. The exact mechanisms driving this association warrant further exploration.

Weight maintenance and gain were significantly associated with lower risk of all-cause and cancer-related mortality in Korean adults who were newly diagnosed with cancer based on the Korean NHIS-HEALS cohort

The burden of malignant neoplasms is increasing worldwide. Healthy lifestyles such as maintaining a healthy body weight are important to improve survival rate in cancer patients. This study was aimed to test the hypothesis that weight change affects mortality in patients newly diagnosed with cancer. This study was retrospectively designed based on the National Health Insurance Service-National Health Screening Cohort. A total of 1856 subjects aged at least 40 years who received a national health checkup within 6 months before cancer diagnosis was included. Study subjects were classified into 3 categories based on weight change before and after cancer diagnosis: weight loss, maintenance, and gain. Cox proportional hazards regression models were adopted to examine the association between weight change and mortality after adjusting for confounders. Compared to those experiencing weight loss, the adjusted hazards ratios (HRs) (95% confidence intervals [CIs]) for those experiencing weight maintenance were 0.327 (0.189-0.568) for all-cause mortality and 0.431 (0.215-0.867) for cancer-related mortality. The adjusted HRs (95% CIs) for those experiencing weight gain were 0.149 (0.044-0.505) for all-cause mortality and 0.289 (0.080-1.045) for cancer-related mortality. After stratifying according to baseline body mass index (BMI), weight maintenance and gain were negatively associated with all-cause mortality (0.286 [0.138-0.592] for weight maintenance and 0.119 [0.027-0.533] for weight gain) among those with a BMI < 25 kg/m2. Weight maintenance and gain reduced the risk of all-cause mortality in patients newly diagnosed with any cancer. In addition, weight maintenance was significantly related to cancer-related mortality.

Adherence and clinical outcomes for twice-daily versus once-daily dosing of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: Is dosing frequency important?

BACKGROUND

Twice-daily dosing of non-vitamin K antagonist oral anticoagulants (NOACs) may reduce drug adherence compared with once-daily dosing of NOACs in patients with atrial fibrillation (AF), thus worsening clinical outcomes. We evaluated adherence to apixaban and dabigatran requiring twice-daily dosing compared with edoxaban or rivaroxaban with a once-daily dosing regimen and the subsequent clinical outcomes in patients with AF.

METHODS

Adherence to each NOAC and outcomes were compared between patients who were diagnosed with AF and initiated NOACs between 2016 and 2017 using Korean claims data. High adherence was defined as the proportion of days covered (PDC) of the index NOAC ≥80%. The clinical outcomes included stroke, acute myocardial infarction, death, and composite outcome.

RESULTS

A total of 33,515 patients were analyzed (mean follow-up, 1.7 ± 1.3 years). The proportion of patients with high adherence to NOACs was 95%, which did not significantly differ according to the dosing regimen. The mean PDC for NOACs was as high as ~96%, which was the highest for apixaban users, intermediate for edoxaban or rivaroxaban users, and lowest for dabigatran users, regardless of the dosing regimen. Adverse outcomes in low adherence patients for each NOAC were higher than that of high adherence patients, regardless of the dosing frequency.

CONCLUSIONS

Adherence between once- and twice-daily dosing NOACs in patients with AF was high and similar among both dosing regimens. Patients with low NOAC adherence had poorer clinical outcomes, regardless of the dosing frequency.

Severe hypoglycemia and risk of hospitalization for heart failure in adults with diabetes treated with oral medications with or without insulin: A population-based study

AIMS

We aimed to determine if severe hypoglycemia (SH) independently increases the risk of hospitalization for heart failure (hHF) in type 2 diabetes, regardless of the prevalent or incident cardiovascular disease (CVD).

METHODS

This was a nationwide population-based propensity score-matched study using Korean National Health Insurance Service data (2002-2018). The hazards of hHF were compared in individuals who experienced SH (n = 8,965) and 1:3 matched controls, among adults with diabetes using oral anti-diabetes medications (OADs) with or without insulin and without previous hHF at baseline.

RESULTS

During 236,417 person-years, 1,189 cases of hHF occurred. The hazard of hHF was higher in individuals with SH compared to matched controls (adjusted hazard ratio [aHR] 1.503, 95 % confidence interval [CI] 1.324-1.707). The increase in aHR remained significant when excluding participants with prevalent or incident major adverse cardiovascular events (MACE; aHR 1.352, 95 % CI 1.228-1.622) and any CVD (aHR 1.342, 95 % CI 1.025-1.756). Two or more SH events were associated with further increase in hHF risk.

CONCLUSION

SH was associated with increased risks of hHF among adults with diabetes using OAD with or without insulin. The increased risk was attenuated but remained significant in those without prevalent or incident MACE or CVDs.

Metformin Use May Increase Risk of Pancreatic Cancer in Diabetic Women: An Analysis of the Korean National Health Insurance Service-National Health Screening Cohort Database

Background: In addition to its antidiabetic effects, metformin has pleiotropic effects, such as the inhibition of carcinogenesis. This study aimed to investigate the association between metformin use and pancreatic cancer risk in the Korean National Health Insurance Service (NHIS)-National Health Screening Cohort (HEALS).Methods: Of the individuals in the Korean NHIS-HEALS, 29,271 men and 19,091 women were included in the final analysis after propensity score matching based on age, body mass index, and smoking status. The study population was categorized into three groups: metformin non-users with diabetes mellitus (DM), metformin users with DM, and non-diabetic users. A Cox proportional hazards regression model was used to examine the association between metformin use and pancreatic cancer.Results: The median follow-up period was 12.9 years. The estimated pancreatic cancer incidence was highest in metformin users with DM, regardless of sex (P<0.001), and lowest in non-diabetic men and female metformin non-users (P=0.053). The hazard ratios (95% confidence interval) for pancreatic cancer incidence in metformin users and non-diabetic individuals were 1.116 (0.648–1.923) and 0.447 (0.259–0.771) in men and 2.769 (1.003–7.642) and 1.451 (0.529–3.984) in women, respectively, after full adjustment.Conclusion: Women with diabetes using metformin are at a higher risk of pancreatic cancer than women with diabetes not using metformin. Meanwhile, men with DM using metformin have a similar risk of pancreatic cancer as men with DM not using metformin.

Increased Risk of Cardio-Cerebrovascular Diseases in Migraine Patients: A Nationwide Population-Based, Longitudinal Follow-Up Study in South Korea

Background and Purpose

Migraine is reportedly associated with several cardio-cerebrovascular diseases (CCDs), but some of these diseases have not received sufficient attention. We thus attempted to determine the associations of migraine with peripheral arterial disease (PAD), ischemic heart disease (IHD), atrial fibrillation/flutter (AF), ischemic stroke (IS), and hemorrhagic stroke (HS).

Methods

The study population was recruited by applying International Classification of Diseases, Tenth Revision (ICD-10) codes to the database of the Korean National Health Insurance Service from 2002 to 2018. Cumulative incidence curves were plotted to compare the incidence rates of CCDs between the migraine (ICD-10 code G43; n=130,050) and nonmigraine (n=130,050) groups determined using 1:1 propensity-score matching. Cox proportional-hazards regression models were used to obtain adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for CCDs in patients with any migraine, migraine with aura (n=99,751), and migraine without aura (n=19,562) compared with nonmigraine controls.

Results

For all CCDs, the cumulative incidence rates were higher in the migraine group than the nonmigraine group (p<0.001 in log-rank test). Any migraine, irrespective of the presence of aura, was associated with PAD (aHR 2.29, 95% CI 2.06–2.53), IHD (aHR 2.17, 95% CI 2.12–2.23), AF (aHR 1.84, 95% CI 1.70–1.99), IS (aHR 2.91, 95% CI 2.67–3.16), and HS (aHR 2.46, 95% CI 2.23–2.71). aHR was higher in female than in male migraineurs for all of the CCDs.

Conclusions

Associations of migraine with CCDs have been demonstrated, which are stronger in females than in males.

Body mass index at baseline directly predicts new-onset diabetes and to a lesser extent incident cardio-cerebrovascular events, but has a J-shaped relationship to all-cause mortality

OBJECTIVE

The prevalence of diabetes mellitus (DM), cardio-cerebrovascular diseases (CCVDs) has increased during recent decades. We aimed to investigate the relationship between body mass index (BMI) and each of several outcomes (DM, CCVDs, or mortality) based on the Korean National Health Insurance Service-Health Screening cohort.

METHODS

BMI was categorized as appropriate for Asian populations, into underweight (< 18.5 kg/m²), normal (18.5-< 23 kg/m²), overweight (23-< 25 kg/m²), grade 1 obesity (25-< 30 kg/m²), grade 2 obesity (30-< 35 kg/m²), and grade 3 obesity (≥35 kg/m²). In addition, BMI was further stratified into one unit. Multivariate Cox proportional hazards regression analyses were conducted to examine the association between BMI category and the primary outcomes (DM, CCVDs, or mortality).

RESULTS

A total of 311,416 individuals were included. The median follow-up was 12.5 years. Compared to normal BMI, underweight, overweight, and grade 1-3 obese individuals had a higher risk of the primary outcomes (hazard ratio [95% confidence intervals] 1.293 [1.224-1.365], 1.101 [1.073-1.129], 1.320 [1.288-1.353], 1.789 [1.689-1.897], and 2.376 [2.019-2.857], respectively, in men and 1.084 [1.010-1.163], 1.150 [1.116-1.185], 1.385 [1.346-1.425], 1.865 [1.725-2.019], and 2.472 [2.025-3.028], respectively, in women). Setting the reference BMI to 20-< 21 kg/m² and categorizing into one unit increment, BMI was associated with the primary outcomes in a J-shaped manner in both sexes. The risk of DM increased with higher BMI in both sexes, while all-cause mortality decreased in men with a BMI 21-< 31 kg/m² and women with BMI 22-< 30 kg/m².

CONCLUSIONS

BMI was associated with all-cause mortality in a J-shaped manner in both sexes, while it was associated with risk of DM in a dose-response relationship. The relationship between BMI and the primary outcomes was J-shaped.

The ratio of triglycerides to high-density lipoprotein cholesterol is associated with the risk of chronic kidney disease in Korean men

Dyslipidemia is nephrotoxic and can result in the development of chronic kidney disease (CKD). The ratio of triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) (TG/HDL-C ratio) is well-correlated with insulin resistance and cardiovascular events. The aim of this study is to examine the association between the TG/HDL-C ratio and CKD in Korean adults. This study was retrospectively designed based on the National Health Insurance Service-National Health Screening cohort. Seventy three thousand and fifty-two participants aged between 40 and 79 years old at baseline (2009-2010) were included in the final analyses. The study population was classified into three tertile groups (T₁ , T₂ , and T₃ ) according to the TG/HDL-C ratio by sex. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for CKD were calculated using Cox proportional hazard regression models. The median follow-up duration was 5.9 years. Higher tertile groups of the TG/HDL-C ratio had lower estimated glomerular filtration rates in both sexes. The cumulative incidence of CKD of T₁ , T₂ , and T₃ was 11.89%, 12.90%, and 12.91%, respectively, in men and 10.17%, 10.61%, and 14.87%, respectively, in women (all p values < 0.001). Compared with T₁ of the TG/HDL-C ratio, the HRs (95% CIs) of T₂ and T₃ for CKD were 1.212 (1.118-1.315) and 1.183 (1.087-1.287), respectively, in men and 0.895 (0.806-0.994) and 1.038 (0.937-1.150), respectively, in women after being fully adjusted. Higher TG/HDL-C ratios were positively associated with CKD development in men, while middle levels of TG/HDL ratios reduced the CKD incidence in women.

Determining the Degree of Dopaminergic Denervation Based on the Loss of Nigral Hyperintensity on SMWI in Parkinsonism

BACKGROUND AND PURPOSE

Nigrostriatal dopaminergic function in patients with Parkinson disease can be assessed using ¹²³I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropan dopamine transporter (¹²³I-FP-CIT) SPECT, and a good correlation has been demonstrated between nigral status on SWI and dopaminergic denervation on ¹²³I-FP-CIT SPECT. Here, we aim to correlate quantified dopamine transporter attenuation on ¹²³I-FP-CIT SPECT with nigrosome-1 status using susceptibility map-weighted imaging (SMWI).

MATERIALS AND METHODS

Between May 2017 and January 2018, consecutive patients with idiopathic Parkinson disease (n = 109) and control participants (n = 29) who underwent ¹²³I-FP-CIT SPECT with concurrent 3T SWI were included. SMWI was generated from SWI. Two neuroradiologists evaluated nigral hyperintensity from nigrosome-1 on each side of the substantia nigra. Using consensus reading, we compared the ¹²³I-FP-CIT-specific binding ratio according to nigral hyperintensity status and the ¹²³I-FP-CIT specific binding ratio threshold to confirm the loss of nigral hyperintensity was determined using receiver operating characteristic curve analysis.

RESULTS

The concordance rate between SMWI and ¹²³I-FP-CIT SPECT was 65.9%. The ¹²³I-FP-CIT-specific binding ratios in the striatum, caudate nucleus, and putamen were significantly lower when nigral hyperintensity in the ipsilateral substantia nigra was absent than when present (all, P < .001). The ¹²³I-FP-CIT-specific binding ratio threshold values for the determination of nigral hyperintensity loss were 2.56 in the striatum (area under the curve, 0.890), 3.07 in the caudate nucleus (0.830), and 2.36 in the putamen (0.887).

CONCLUSIONS

Nigral hyperintensity on SMWI showed high positive predictive value and low negative predictive value with dopaminergic degeneration on ¹²³I-FP-CIT SPECT. In patients with Parkinson disease, the loss of nigral hyperintensity is prominent in patients with lower striatal specific binding ratios.

Metformin use in cancer survivors with diabetes reduces all-cause mortality, based on the Korean National Health Insurance Service between 2002 and 2015

Malignant neoplasms are the leading cause of death in Korea. We aimed to examine if metformin use in cancer survivors reduces all-cause mortality. This study was retrospectively designed based on data from the Korean National Health Insurance Service-National Health Screening Cohort (HEALS) between 2002 and 2015. The Kaplan-Meier estimator and log-rank test was performed to estimate the survival function according to metformin usage (3721 metformin non-users with diabetes, 5580 metformin users with diabetes, and 24,483 non-diabetic individuals). Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality were calculated using Cox proportional hazards regression models.The median follow-up duration was 4.2 years. The HRs (95% CIs) for all-cause mortality of metformin users and the non-diabetic group were 0.762 (0.683-0.850) and 1.055 (0.966-1.152) in men and 0.805 (0.649-0.999), and 1.049 (0.873-1.260) in women, respectively, compared with metformin non-users among diabetic cancer survivors, in a fully adjusted model. After stratifying metformin users into pre- and post-diagnosis of cancers, adjusted HRs (95% CIs) of pre- and post-diagnosis metformin users for all-cause mortality were 0.948 (0.839-1.071) and 0.530 (0.452-0.621) in men and 1.163 (0.921-1.469) and 0.439 (0.323-0.596) in women, respectively.Metformin use in cancer survivors with diabetes reduced overall mortality rates. In particular, metformin use after cancer diagnosis, not before cancer diagnosis, was inversely associated with overall mortality.Active treatment with metformin for diabetic cancer survivors after cancer diagnosis can improve their survival rates.

Metformin use in elderly population with diabetes reduced the risk of dementia in a dose-dependent manner, based on the Korean NHIS-HEALS cohort

AIMS

The aim of this study is to investigate the association between metformin usage and dementia in an elderly Korean population.

METHODS

Participants were divided into five groups: metformin non-users with diabetes mellitus (DM), metformin users with DM (low-, mid-, and high-users), and non-diabetic Individuals. Dementia was defined with primary diagnostic dementia codes according to the 10th edition of the International Classification of Diseases. To compare the incidence rate of dementia among the five groups, Kaplan-Meier estimates and log-rank test were employed. Also, to control the confounding factors, Cox proportional hazards regression models were fitted in a sequential adjustment.

RESULTS

The median follow-up was 12.4 years. The overall incidence rate of dementia was 11.3% (8.4% in men and 13.9% in women). Compared with metformin non-users, hazard ratios (95% confidence intervals) of low-, mid-, and high-users and non-diabetic individuals for dementia were 0.97 (0.73-1.28), 0.77 (0.58-1.01), 0.48 (0.35-0.67), and 0.98 (0.84-1.15), respectively, in men, respectively, and 0.90 (0.65-0.98), 0.61 (0.50-0.76), 0.46 (0.36-0.58), and 0.92 (0.81-1.04), respectively, in women, after full adjustment of confounding variables.

CONCLUSIONS

Metformin use in an elderly population with DM reduced dementia risk in a dose-response manner.

MRI-Based Assessment of the Pharyngeal Constrictor Muscle as a Predictor of Surgical Margin after Transoral Robotic Surgery in HPV-Positive Tonsillar Cancer

BACKGROUND AND PURPOSE

Transoral robotic surgery is an emerging strategy for treating human papillomavirus-positive cancers, but the role of MR imaging in predicting the surgical outcome has not been established. We aimed to identify preoperative MR imaging characteristics that predispose the outcome of transoral robotic surgery toward an insecure (positive or close) surgical margin in human papillomavirus-positive tonsillar squamous cell carcinoma.

MATERIALS AND METHODS

Between December 2012 and May 2019, sixty-nine patients underwent transoral robotic surgery at our institution. Among these, 29 who were diagnosed with human papillomavirus-positive tonsillar squamous cell carcinoma, did not receive neoadjuvant treatment, underwent preoperative 3T MR imaging, and had postoperative pathologic reports and were included in this retrospective study. Two neuroradiologists evaluated the preoperative MR imaging scans to determine the tumor spread through the pharyngeal constrictor muscle using a 5-point scale: 1, normal constrictor; 2, bulging constrictor; 3, thinning constrictor; 4, obscured constrictor; and 5, tumor protrusion into the parapharyngeal fat. The risk of an insecure surgical margin (involved or <1 mm) according to the MR imaging scores was predicted using logistic regression with the Firth correction.

RESULTS

The interobserver agreement for the MR imaging scores was excellent (κ = 0.955, P < .001). A score of ≥4 could predict an insecure margin with 87.5% sensitivity and 92.3% specificity (area under the curve = 0.899) and was the only significant factor associated with an insecure margin in the multivariable analysis (OR, 6.59; 95% CI, 3.11-22.28; P < .001).

CONCLUSIONS

The pre-transoral robotic surgery MR imaging scoring system for the pharyngeal constrictor muscle is a promising predictor of the surgical margin in human papillomavirus-positive tonsillar squamous cell carcinoma.

Metformin use reduced the overall risk of cancer in diabetic patients: A study based on the Korean NHIS-HEALS cohort

BACKGROUND AND AIM

Several studies have reported the preventive effect of metformin on cancer development. This study aimed to investigate the relationship between use of metformin and risk of cancer in Koreans.

METHODS AND RESULTS

This study was designed retrospectively using the National Health Insurance Service-National Health Screening Cohort conducted between 2002 and 2015. 40 to 69-year-old subjects who received a health screening examination from 2002 to 2003 were enrolled. Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer were estimated in a multivariate Cox proportional regression analysis. A total of 323,430 subjects was enrolled (301,905 individuals without diabetes [No DM], 8643 diabetic patients with metformin treatment [metformin users], and 12,882 diabetic patients without metformin treatment [metformin non-users]). The median follow-up period was 12.7 years. Cumulative incidence of overall cancer was 7.9% (7.7, 10.3, and 11.1% in No DM, metformin users and non-users, respectively). Compared to metformin non-users, the fully adjusted HRs (95% CIs) of metformin users and No DM for overall cancer incidence were 0.73 (0.66-0.81) and 0.75 (0.64-0.88), respectively, in men and 0.83 (0.78-0.89) and 0.81 (0.72-0.92) in women.

CONCLUSIONS

Diabetic patients receiving metformin treatment, and individuals without diabetes were at lower risk for cancer incidence than diabetic patients without metformin treatment.

Feasibility of Permanent Stenting with Solitaire FR as a Rescue Treatment for the Reperfusion of Acute Intracranial Artery Occlusion

BACKGROUND AND PURPOSE

The Solitaire FR can be used not only as a tool for mechanical thrombectomy but also as a detachable permanent stent. Our aim was to assess the feasibility and safety of permanent stent placement with the Solitaire FR compared with other self-expanding stents for intracranial artery recanalization for acute ischemic stroke.

MATERIALS AND METHODS

From January 2011 through January 2016, we retrospectively selected 2979 patients with acute ischemic stroke. Among them, 27 patients who underwent permanent stent placement (13 patients with the Solitaire FR [Solitaire group] and 14 patients with other self-expanding stents [other stent group]) were enrolled. The postprocedural modified TICI grade and angiographic and clinical outcomes were assessed. The safety and efficacy of permanent stent placement of the Solitaire FR for acute large-artery occlusion were evaluated.

RESULTS

Stent placement was successful in all cases. Modified TICI 2b-3 reperfusion was noted in 84.6% of the Solitaire group and in 78.6% of the other stent group. Procedural time was significantly shorter in the Solitaire group than in the other stent group (P = .022). Shorter procedural time was correlated with favorable outcome (ρ = 0.46, P = .035). No significant differences were found in the modified TICI grade, NIHSS score, mRS, and hemorrhagic transformation rate between the 2 groups. The acute in-stent thrombosis rate at discharge was significantly lower when a glycoprotein IIb/IIIa inhibitor was injected during the procedure (P = .013).

CONCLUSIONS

Permanent stent placement with the Solitaire FR compared with other self-expanding stents appears to be feasible and safe as a rescue tool for refractory intra-arterial therapy.

Diffusion-Weighted Imaging of the Head and Neck: Influence of Fat-Suppression Technique and Multishot 2D Navigated Interleaved Acquisitions

BACKGROUND AND PURPOSE

DWI of the head and neck can reveal valuable information, but the effects of fat suppression and multishot acquisition on image quality have not been thoroughly investigated. We aimed to comprehensively compare the quality of head and neck DWI at 3T using 2 fat-suppression techniques, STIR, and spectral presaturation with inversion recovery, which were used with both single- and multishot EPI.

MATERIALS AND METHODS

Sixty-five study participants underwent 3 DWI sequences of single-shot EPI-STIR, single-shot EPI-spectral presaturation with inversion recovery, and multishot EPI-spectral presaturation with inversion recovery of the head and neck. In multiple anatomic regions, 2 independent readers assessed 5-point visual scores for fat-suppression uniformity and image distortion, and 1 reader measured the contrast-to-noise ratio and ADC.

RESULTS

The mean visual score for fat-suppression uniformity was higher in single-shot EPI-STIR than in other sequences (all regions except for the orbital region, P < .05). The mean visual score for image distortion was higher in multishot EPI-spectral presaturation with inversion recovery than in single-shot EPI sequences (all regions, P < .001). Contrast-to-noise ratio was mostly lower in single-shot EPI-STIR than in other sequences (P < .001), and ADC was significantly higher in multishot EPI-spectral presaturation with inversion recovery than in single-shot EPI sequences (P ≤ .001).

CONCLUSIONS

Overall, multishot EPI-spectral presaturation with inversion recovery provided the best image quality, with relatively homogeneous fat suppression, less image distortion than single-shot EPI sequences, and higher contrast-to-noise ratio than single-shot EPI-STIR. The measured ADC values can be higher in multishot EPI-spectral presaturation with inversion recovery, which necessitates cautious application of the previously reported ADC values to clinical settings.

The Role of MRI in Diagnosing Neurovascular Compression of the Cochlear Nerve Resulting in Typewriter Tinnitus

BACKGROUND AND PURPOSE

Typewriter tinnitus, a symptom characterized by paroxysmal attacks of staccato sounds, has been thought to be caused by neurovascular compression of the cochlear nerve, but the correlation between radiologic evidence of neurovascular compression of the cochlear nerve and symptom presentation has not been thoroughly investigated. The purpose of this study was to examine whether radiologic evidence of neurovascular compression of the cochlear nerve is pathognomonic in typewriter tinnitus.

MATERIALS AND METHODS

Fifteen carbamazepine-responding patients with typewriter tinnitus and 8 control subjects were evaluated with a 3D T2-weighted volume isotropic turbo spin-echo acquisition sequence. Groups 1 (16 symptomatic sides), 2 (14 asymptomatic sides), and 3 (16 control sides) were compared with regard to the anatomic relation between the vascular loop and the internal auditory canal and the presence of neurovascular compression of the cochlear nerve with/without angulation/indentation.

RESULTS

The anatomic location of the vascular loop was not significantly different among the 3 groups (all, P > .05). Meanwhile, neurovascular compression of the cochlear nerve on MR imaging was significantly higher in group 1 than in group 3 (P = .032). However, considerable false-positive (no symptoms with neurovascular compression of the cochlear nerve on MR imaging) and false-negative (typewriter tinnitus without demonstrable neurovascular compression of the cochlear nerve) findings were also observed.

CONCLUSIONS

Neurovascular compression of the cochlear nerve was more frequently detected on the symptomatic side of patients with typewriter tinnitus compared with the asymptomatic side of these patients or on both sides of control subjects on MR imaging. However, considering false-positive and false-negative findings, meticulous history-taking and the response to the initial carbamazepine trial should be regarded as more reliable diagnostic clues than radiologic evidence of neurovascular compression of the cochlear nerve.

Potential for the use of the Solitaire stent for recanalization of middle cerebral artery occlusion without a susceptibility vessel sign

BACKGROUND AND PURPOSE

Absence of the MCA susceptibility vessel sign (negative MCA susceptibility vessel sign) on gradient recalled-echo MR imaging in acute stroke is commonly associated with in situ stenosis and thrombotic occlusion. We evaluated the effectiveness and safety of the Solitaire stent as the first-line device for the recanalization of MCA occlusion with a negative MCA susceptibility vessel sign.

MATERIALS AND METHODS

Thirty-eight consecutive patients presenting with acute ischemic stroke due to MCA occlusion were treated by using the Solitaire AB stent alone or combined with thrombolytic drugs. Among these patients, 11 (7 men and 4 women; median age, 70 years; range, 49-89 years) who underwent multimodal stroke MR imaging before the endovascular procedure and had no MCA susceptibility vessel sign on the initial gradient recalled-echo MR imaging were included in this study. The primary end point was the recanalization of the occluded artery evaluated by the arterial occlusive lesion score. Clinical outcome was assessed at discharge and 90 days, as was the degree of residual MCA stenosis or reocclusion.

RESULTS

Successful recanalization (arterial occlusive lesion score ≥ II) without balloon angioplasty was obtained in 9 patients (81.8%). Six patients (54.5%) had an mRS score of ≤2 at 90 days. After a median of 147 days, no patient showed reocclusion on follow-up imaging. There were no symptomatic intracerebral hemorrhages.

CONCLUSIONS

The Solitaire stent is a feasible tool as the first-line device for multimodal endovascular recanalization therapy in acute ischemic stroke with a negative MCA susceptibility vessel sign. It has a good rate of successful and complete recanalization and is a fast yet safe procedure.

Cloning and sequence analysis of Gpdh in Callosobruchus chinensis (Coleoptera: Bruchidae)

The Sn-Glycerol-3-phosphate dehydrogenase (GPDH: NAD+ 2-oxidoreductase, EC 1.1.1.8) gene of C. chinensis was cloned and its nucleotide sequence was analyzed. The gene was obtained by screening a genomic library with Drosophila melanogaster Gpdh and PCR amplification. The 5,126 bp gene obtained is comprised of one 5' untranslated region, eight exons, seven introns, and three 3' untranslated regions. Comparison of Gpdh of D. melanogaster with that of C. chinensis showed a 89.9% identity in the coding region, 70% in the intron, 79% in the entire nucleotide sequence, and 83.2% in the deduced amino acid sequence. The transcription initiation site is located 33 nucleotides upstream of the initiation codon, and the sequence analysis of the promoter region showed TATA and CAAT boxes at the 5' end. The stop codon (TAA) and polyadenylation signal (AATAAA) are located at the 3' end of each of the exons 6 to 8. These findings show that GPDH isozymes in C. chinensis are produced by the alternative processing of 3' exons. The occurrence of the three transcripts was proven by RT-PCR using synthetic oligonucleotides complementary to the predicted unique 3' regions. Compared to the D. melanogaster GPDH isozymes, GPDH-1, -2, and -3, C. chinensis GPDH showed 83.6%, 83%, and 84% identities, respectively.

Anomalous insertion of the medial menisci

Many types of meniscal anomalies have been reported. The authors encountered two cases of anomalous insertion of the anterior horn of the medial menisci to the lateral femoral condyle, which ran up along the course of the anterior cruciate ligament (ACL), but was independent of the ACL. These anomalies were noted during arthroscopic examination and surgery of the ipsilateral knee for a torn discoid meniscus and a patellar fracture. A 34-year-old woman had a horizontal tear of the lateral discoid meniscus. We performed arthroscopic partial meniscectomy of the inner torn portion of the lateral discoid meniscus and contoured it to resemble a normal meniscus. An anomalous insertion of the medial meniscus was found on examination of the joint during surgery. A 32-year-old man had a patellar fracture and we performed reduction under arthroscopy and internal fixation with cannulated screws. The same anomalous insertion of the medial meniscus was also found on examination of the joint during surgery. We report the cases with a review of the literature.

Patterns of human tumor-infiltrating lymphocytes in 120 human cancers

Tumor-infiltrating lymphocytes from 120 samples of human cancers, including melanoma, renal cell carcinoma, breast cancer, sarcoma, and colon cancer, were examined. The percentage of lymphocytes recovered from the cancer varied widely; that of renal cell carcinoma was higher than that of breast or colon cancer (65% vs 45%), which was higher than that of melanomas or sarcomas (30% to 35%). The types of lymphocytes before and after interleukin 2 activation showed specific patterns. CD4+ helper T cells predominated in all tumors except melanomas, which had more CD8+ cytotoxic T cells. CD16+ natural killer cells were recovered in renal cell carcinoma and sarcomas. Three different cytotoxic lymphocytes were identified among interleukin 2-activated tumor-infiltrating lymphocytes: (1) CD3+ CD16- cytotoxic T lymphocytes with cytotoxicity restricted to autologous tumor cells in melanomas, (2) CD3-CD16+ natural killer cells with vigorous major histocompatibility complex-nonrestricted cytotoxicity in renal cell carcinoma, and (3) CD3+ CD16- T cells with modest levels of major histocompatibility complex-nonstricted cytotoxicity in all cancers except melanomas. Thus, there was considerable diversity of tumor-infiltrating lymphocytes among these histologically distinct tumors with respect to magnitude of lymphocyte infiltration, phenotypic expression, and functional capacity.