Impact of Baseline Stroke Risk and Bleeding Risk on Warfarin International Normalized Ratio Control in Atrial Fibrillation (from the TREAT-AF Study)

Warfarin prevents stroke and prolongs survival in patients with atrial fibrillation and flutter (AF, collectively) but can cause hemorrhage. The time in international normalized ratio (INR) therapeutic range (TTR) mediates stroke reduction and bleeding risk. This study sought to determine the relation between baseline stroke, bleeding risk, and TTR. Using data from The Retrospective Evaluation and Assessment of Therapies in Atrial Fibrillation (TREAT-AF) retrospective cohort study, national Veterans Health Administration records were used to identify patients with newly diagnosed AF from 2003 to 2012 and subsequent initiation of warfarin. Baseline stroke and bleeding risk was determined by calculating CHA₂DS₂-VASc and HAS-BLED scores, respectively. Main outcomes were first-year and long-term TTR and INR monitoring rate. In 167,190 patients, the proportion of patients with TTR (>65%) decreased across increasing strata of CHA₂DS₂-VASc and HAS-BLED. After covariate adjustment, odds of achieving TTR >65% were significantly associated with high CHA₂DS₂-VASc or HAS-BLED score. INR monitoring rate was similar across risk strata. In conclusion, increased baseline stroke and bleeding risk is associated with poor INR control, despite similar rates of INR monitoring. These findings may paradoxically limit warfarin's efficacy and safety in high-risk patients and may explain observed increased bleeding and stroke rates in this cohort.

Diagnostic performance of contrast-enhanced ultrasound in the evaluation of renal masses in patients with renal impairment

OBJECTIVE

To evaluate the performance of contrastenhanced ultrasound (CEUS) in the risk stratification of indeterminate renal lesions picked up incidentally on abdominal imaging, in patients with renal impairment.

METHODS

A retrospective study was performed of nonconsecutive patients who underwent CEUS at our tertiary care centre for indeterminate renal lesions between March 2010 and September 2014. A total of 63 patients with 74 nodules were assessed with CEUS and stratified into either benign (Bosniak I, II, IIF) or suspicious for malignancy (Bosniak III, IV or hypervascular solid lesions). Diagnostic accuracy was determined by comparing these findings to subsequent histological diagnoses, temporal change after at least 20 months follow-up or after a diagnostic computer tomography / magnetic resonance imaging study.

RESULTS

CEUS correctly identified 49/52 (94.2%) of benign lesions and 21/22 (95.5%) of malignant lesions, resulting in a sensitivity of 95.5% (95% CI 77.2-99.9%), specificity of 94.2% (95% CI 84.1-98.8%), positive predictive value (PPV) 87.5% (95% CI 67.6-97.3) and negative predictive value (NPV) 98.0% (95% CI 89.4-100%).

CONCLUSION

CEUS has high diagnostic performance in predicting the benignity of a renal lesion in patients with renal impairment, showing sensitivity and NPV approaching 100%.

Racial Differences in Quality of Anticoagulation Therapy for Atrial Fibrillation (from the TREAT-AF Study)

The influence of race on quality of anticoagulation control is not well described. We examined the association between race, international normalized ratio (INR) monitoring intensity, and INR control in warfarin-treated patients with atrial fibrillation (AF). Using data from the Veterans Health Administration (VHA), we performed a retrospective cohort study of 184,161 patients with a new diagnosis of AF/flutter from 2004 to 2012 who received any VHA prescription within 90 days of diagnosis. The primary predictor was race, ascertained from multiple VHA and linked Medicare demographic files. The primary outcome was first-year and long-term time in therapeutic range (TTR) of INR 2.0 to 3.0. Secondary outcomes were INR monitoring intensity and warfarin persistence. Of the 116,021 patients who received warfarin in the cohort, INR monitoring intensity was similar across racial groups. However, TTR was lowest in blacks and highest in whites (first year 0.49 ± 0.23 vs 0.57 ± 0.21, p <0.001; long term 0.52 ± 0.20 vs 0.59 ± 0.18, p <0.001); 64% of whites and 49% of blacks had long-term TTR >55% (p <0.001). After adjusting for site and patient-level covariates, black race was associated with lower first-year and long-term TTRs (4.2% and 4.1% below the conditional mean, relative to whites; p <0.0001 for both). One-year warfarin persistence was slightly lower in blacks compared to whites (58% vs 60%, p <0.0001). In conclusion, in patients with AF anticoagulated with warfarin, differences in INR control are most evident among blacks, underscoring the need to determine if other types of intensive management or warfarin alternatives may be necessary to improve anticoagulation among vulnerable AF populations.

Justification of an introductory electrocardiogram teaching mnemonic by demonstration of its prognostic value

OBJECTIVES

With diminishing time afforded to electrocardiography in the medical curriculum, we have found Sibbitt's simple mnemonic, the Diagonal Line Lead Rule, for a pattern recognition approach to 12-lead electrocardiogram (ECG) interpretation to be appreciated by students. However, it still lacks universal acceptance because its clinical utility has not been documented. The study objective was to demonstrate the clinical utility of the Diagonal Line Lead ECG Teaching Rule.

METHODS

After excluding ECGs of high-risk patients with Wolff-Parkinson-White syndrome and QRS durations greater than 120 ms, the initial ECGs of the remaining 43,798 patients were scored according to the Diagonal Line Lead Rule. A total of 45,497 patients from the Veterans Affairs Palo Alto Healthcare System were referred for a routine initial resting ECG from 1987 to 1999. We determined cardiovascular mortality with 8 years of follow-up.

RESULTS

In patients with normal QRS duration, diagnostic Q-wave or T-wave inversions isolated to the diagonal line leads showed no increased risk of cardiovascular death. Q-wave or T-wave inversion in any other lead was significantly associated with cardiovascular death with an age-adjusted Cox hazard of 2.6 (confidence interval, 2.4-2.8; P < .0001) and an annual cardiovascular mortality rate of 3.0%. Leads V4-V6, I, and aVL were especially significant predictors of cardiovascular death, with a Cox hazard greater than 3.

CONCLUSIONS

Our analysis demonstrates the prognostic power and clinical utility of a simple mnemonic for 12-lead ECG interpretation that can facilitate ECG teaching and interpretation.

A Case of Primitive Trigeminal Artery-Cavernous Fistula: Embolization, Complications and Strategy

A 22-year-old man with primitive trigeminal artery-cavernous fistula was admitted to our hospital. Embolization with Guglielmi detachable coils and microcoils was attempted on the fistula from the internal carotid artery. The last microcoil was incorrectly released to the basilar artery through the primitive trigeminal artery. The misplaced microcoil was eventually retrieved by goose-neck snare. There was no related complication in the follow-up period.

Safety of cardiac catheterization in patients with end-stage liver disease awaiting liver transplantation

Patients with end-stage liver disease (ESLD) are predisposed to bleeding complications due to thrombocytopenia, reduced synthesis of coagulation factors, and increased fibrinolytic activity. The exact incidence of vascular access site and bleeding complications related to cardiac catheterization in this group remains unknown. Eighty-eight consecutive patients with ESLD who underwent left-sided cardiac catheterization from August 2004 to February 2007 were identified. Eighty-one patients without known liver disease matched for age, gender, and body mass index who underwent left-sided cardiac catheterization during the same period were chosen as the control group. Vascular complications were defined as hematoma >5 cm, pseudoaneurysm, arteriovenous fistula, or retroperitoneal bleeding. Patients with ESLD had lower baseline mean hematocrit (32.3 +/- 6.0% vs 39.2 +/- 6.2%, p <0.001) and mean platelet count (90.1 +/- 66.3 vs 236.1 +/- 77.1 x 10(9)/L, p <0.001) compared with controls. They also had higher mean serum creatinine (1.9 +/- 1.7 vs 1.2 +/- 0.8 mg/dl, p = 0.002) and mean international normalized ratio (1.6 +/- 0.7 vs 1.1 +/- 0.2, p <0.001). There were more complicated pseudoaneurysms in the patients with liver failure (5.7% [5 of 88]), compared with 0% in controls (p = 0.029). Patients with ESLD had lower starting hemoglobin levels and greater reductions in hemoglobin after cardiac catheterization, resulting in greater need for packed red blood cell transfusion (16% vs 4%, p = 0.008), fresh frozen plasma (51.7% vs 1.2%, p <0.001), and platelet transfusions (48.3% vs 1.2%, p <0.001). Major bleeding was higher in the ESLD group (14.8% vs 3.7%, p = 0.014), driven mainly by the need for blood transfusion. In conclusion, despite severe coagulopathy, left-sided cardiac catheterization may be performed safely in this patient population, with correction of coagulopathy and meticulous attention to procedural technique.

Partial hepatectomy and subsequent radiation facilitates engraftment of mouse embryonic stem cells in the liver

For liver-targeted regenerative medicine, embryonic stem (ES) cell-derived hepatocyte-like cells proffer great expectation. In vitro exposure to a combination of various growth factors, such as hepatocyte growth factor and fibroblast growth factor-4, as well as cytokines, leads to differentiation of ES cells into hepatocyte-like cells. We sought to determine the in vivo environment that allowed engraftment of ES cells transplanted to the liver. Thus, we examined the effect of partial hepatectomy (50%) (PHT) and subsequent radiation (RT) of the male Balb/c mouse host liver on ES cell engraftment. ES cells (5 x 10(6)) derived from 129Sv mice were transplanted into the residual liver. The controls were ES cells transplanted into a normal liver. Bromo-deoxy-residine (BrdU)-uptake was performed to evaluate the effect of hepatectomy and RT on hepatocyte regeneration. Mouse ES cells engrafted, forming teratomas in the normal liver without showing any mononuclear infiltration. A liver modified by PHT and RT facilitated engraftment of mouse ES cells compared with a normal liver. Hepatic RT significantly suppressed hepatocytic uptake of BrdU.

Macroscopic dynamics in separable neural networks

Parallel dynamics of neural networks with separable coupling is given starting from Coolen-Sherrington theory. Away from saturation, it is shown that this parallel retrieve dynamics is equivalent to the sequential dynamics for finite temperature. But the finite-size effects were found to be governed by a homogeneous Markov process, not by a time-dependent Ornstein-Uhlenbeck process in sequential dynamics.

A molecular clone of simian-human immunodeficiency virus (DeltavpuSHIV(KU-1bMC33)) with a truncated, non-membrane-bound vpu results in rapid CD4(+) T cell loss and neuro-AIDS in pig-tailed macaques

We report on the role of vpu in the pathogenesis of a molecularly cloned simian-human immunodeficiency virus (SHIV(KU-1bMC33)), in which the tat, rev, vpu, env, and nef genes derived from the uncloned SHIV(KU-1b) virus were inserted into the genetic background of parental nonpathogenic SHIV-4. A mutant was constructed (DeltavpuSHIV(KU-1bMC33)) in which 42 of 82 amino acids of Vpu were deleted. Phase partitioning studies revealed that the truncated Vpu was not an integral membrane protein, and pulse-chase culture studies revealed that cells inoculated with DeltavpuSHIV(KU-1bMC33) released viral p27 into the culture medium with slightly reduced kinetics compared with cultures inoculated with SHIV(KU-1bMC33). Inoculation of DeltavpuSHIV(KU-1bMC33) into two pig-tailed macaques resulted in a severe decline of CD4(+) T cells and neurological disease in one macaque and a more moderate decline of CD4(+) T cells in the other macaque. These results indicate that a membrane-bound Vpu is not required for the CD4(+) T cell loss and neurological disease in SHIV-inoculated pig-tailed macaques. Furthermore, because the amino acid substitutions in the Tat and Rev were identical to those previously reported for the nonpathogenic SHIV(PPc), our results indicate that amino acid substitutions in the Env and/or Nef were responsible for the observed CD4(+) T cell loss and neurological disease after inoculation with this molecular clone.

Development of terfenadine-pseudoephedrine double-layer tablet dissolution-equivalent to core tablet

The terfenadine-pseudoephedrine dosage form discussed here is the sustained-release core tablet composed of outer (fast-release) and inner (sustained-release) layers. To develop the double-layer tablet dissolution-equivalent to a core tablet, the fast-release and sustained-release layers were prepared using various disintegrants and polymers, respectively. The layer composed of terfenadine/pseudoephedrine/lactose/cornstarch/sodium bicarbonate/hydroxypropylcellulose (HPC)/sodium lauryl sulfate/microcrystalline cellulose (60/10/90/30/20/1/40/1/293 mg), which gave the fast disintegration time and high dissolved amounts of drugs, was selected as the fast-release layer. The dissolved amounts of pseudoephedrine from sustained-release layers increased more with a smaller ratio of ethylcellulose and hydroxypropylmethylcellulose (HPMC). Dissolution mechanism analysis showed the release of pseudoephedrine was proportional to the square root of time, indicating that drug might be released from the layers by Fickian diffusion. The layer composed of pseudoephedrine/ethylcellulose/HPMC (110/30/155 mg), which had similar dissolution amounts of pseudoephedrine as the inner layer of a core tablet, was selected as the sustained-release layer. Furthermore, the dissolved amounts of drugs from the core and double-layer tablets had deviations of less than 5% against the average dissolved amounts of drugs at each time. There was no significant difference between the dissolved amounts of drugs from these tablets at each time in pH 1.2, 4.0, and 6.8 (P > .05). Our results suggest that this double-layer tablet was a dissolution equivalent to the core tablet.

Two regulators of Ste12p inhibit pheromone-responsive transcription by separate mechanisms

The yeast Saccharomyces cerevisiae transcription factor Ste12p is responsible for activating genes in response to MAP kinase cascades controlling mating and filamentous growth. Ste12p is negatively regulated by two inhibitor proteins, Dig1p (also called Rst1p) and Dig2p (also called Rst2p). The expression of a C-terminal Ste12p fragment (residues 216 to 688) [Ste12p(216-688)] from a GAL promoter causes FUS1 induction in a strain expressing wild-type STE12, suggesting that this region can cause the activation of endogenous Ste12p. Residues 262 to 594 are sufficient to cause STE12-dependent FUS1 induction when overexpressed, and this region of Ste12p was found to bind Dig1p but not Dig2p in yeast extracts. In contrast, recombinant glutathione S-transferase-Dig2p binds to the Ste12p DNA-binding domain (DBD). Expression of DIG2, but not DIG1, from a GAL promoter inhibits transcriptional activation by an Ste12p DBD-VP16 fusion. Furthermore, disruption of dig1, but not dig2, causes elevated transcriptional activation by a LexA-Ste12p(216-688) fusion. Ste12p has multiple regions within the C terminus (flanking residue 474) that can promote multimerization in vitro, and we demonstrate that these interactions can contribute to the activation of endogenous Ste12p by overproduced C-terminal fragments. These results demonstrate that Dig1p and Dig2p do not function by redundant mechanisms but rather inhibit pheromone-responsive transcription through interactions with separate regions of Ste12p.

[Amantadine usage for influenza A during an influenza outbreak in a nursing home]

An outbreak of an influenza like illness was found in a nursing home in Fukuoka in January, 1999. Results of hemagglutinin inhibition tests with paired sera of patients and rapid diagnosis kit for influenza A indicated that an influenza A (H3N2) outbreak had occurred. A total of 15 patients with influenza like illness from one residential area of the nursing home were administered amantadine, 100 mg per day for five days. Clinical records of 264 residents were surveyed retrospectively from the tenth to the thirty-first of January, 1999. Influenza like illness was found in 112 residents (42.4%). The incidence of influenza like illness differed by residential area, ranging from 27.6% to 54.0%. The mean duration of fever was 3.6 days among patients administered amantadine. The mean duration was 4.4 days for patients not administered amantadine. The incidence of influenza like illness decreased rapidly after amantadine administration in the residential area where amantadine administration was done. These results suggest that amantadine is effective in mitigating influenza symptoms in the elderly. Amantadine may be useful for diminishing the influence of influenza A outbreaks in nursing homes.

[The efficacy of influenza vaccine among geriatric inpatients]

To investigate the efficacy of influenza vaccine in the elderly, hemagglutination inhibition (HI) antibody titer for the three types of influenza viruses were measured and the influenza infection rate was determined serologically in geriatric inpatients. Influenza vaccination was done for inpatients. For patients who had influenza vaccination in the year prior to the study, influenza vaccine was administered once or twice, and the number of injections were determined randomly. Influenza vaccine was injected twice to those had not received influenza vaccine in the previous year. Serum samples were collected from 166 vaccinated and 104 unvaccinated patients before and after 1996/1997 influenza season. In the vaccinees who had been vaccinated the previous year, 56 patients were injected once and 58 patient were injected twice. Fifty-two patients had not been vaccinated the previous year. Serologically diagnosed influenza infection rate in the 104 unvaccinated patients was 16.3% for influenza A/H3N2 and 8.7% for influenza B. The infection rate was 3.0% for influenza A/H3N2 and 0.6% for influenza B in the 166 vaccinated patients. The infection rates were significantly lower in the vaccinees than in the unvaccinated patients (p < 0.001 with A/H3N2 and p < 0.01 with B). There was no significant difference in the infection rate among the three vaccinated groups. These results suggest that the influenza vaccination had significant protective efficacy for influenza infection in the elderly. Prior vaccination did not diminish the efficacy of the influenza vaccine. The efficacy of a single influenza vaccine injection was equivalent to that of two injection.

Microglial activation and neurological symptoms in the SIV model of NeuroAIDS: association of MHC-II and MMP-9 expression with behavioral deficits and evoked potential changes

HIV-1 causes cognitive and motor deficits and HIV encephalitis (HIVE) in a significant proportion of AIDS patients. Neurological impairment and HIVE are thought to result from release of cytokines and other harmful substances from infected, activated microglia. In this study, the quantitative relationship between microglial activation and neurological impairment was examined in the simian immunodeficiency model of HIVE. Macaque monkeys were infected with a passaged, neurovirulent strain of simian immunodeficiency virus, SIV(mac)239(R71/17E). In concurrent studies, functional impairment was assessed by motor and auditory brainstem evoked potentials and by measurements of cognitive and motor behavioral deficits. Brain tissue was examined by immunohistochemistry using two markers of microglia activation, MHC-II and matrix metalloproteinase-9 (MMP-9). The inoculated animals formed two groups: rapid progressors, which survived 6-14 weeks postinoculation, and slow progressors, which survived 87-109 weeks. In the rapid progressors, two patterns of MHC-II expression were present: (1) a widely disseminated pattern of MHC-II expressing microglia and microglial nodules in cortical gray matter and subcortical white matter, and (2) a more focal pattern in which MHC-II expressing microglia were concentrated into white matter. Animals exhibiting both patterns of microglial activation showed mild to severe changes in cognitive and motor behavior and evoked potentials. All rapid progressors showed expression of MMP-9 in microglia located in subcortical white matter. In the slow progressors MHC-II and MMP-9 staining was similar to uninoculated control macaques, and there was little or no evidence of HIVE. These animals showed behavioral deficits at the end of the disease course, but little changes in evoked potentials. Thus, increases in MHC-II and MMP-9 expression are associated with development of cognitive and motor deficits, alterations in evoked potentials, and rapid disease progression.