Effect of TNFα blockade on UVB-induced inflammatory cell migration and collagen loss in mice

UVB irradiation induces pro-inflammatory cytokines including interleukin-1 (IL-1) and tumor necrosis factor-α (TNFα) in the skin. TNFα stimulates the chemotaxis of inflammatory cells to the skin. These cells secrete metalloproteinases (MMPs) and other enzymes that damage the cutaneous matrix. Therefore, blocking TNFα activity could be effective in preventing the influx of inflammatory cells and subsequent collagen degradation in the skin. In addition, TNFα downregulates procollagen mRNA, and thus blockade may be beneficial to production of type I collagen. Female C57BL/6 J mice were treated with etanercept (TNFα blocker, 4 mg/kg/day) for 4 days 1 h prior to UVB irradiation (100 mJ/cm²/day for 5 days). On the 5th day mice were sacrificed 3 h after UVB exposure. Blocking TNFα significantly inhibited UVB-induced recruitment of macrophages, mast cells, and neutrophils. UVB-irradiated mice skin contained more mature collagen compared to etanercept and UVB + etanercept-treated mice. Skin from UVB + etanercept-treated mice had more collagen fragments relative to UVB-irradiated mice. Procollagen protein was lower in UVB-irradiated and UVB + etanercept-treated mice. TNFα blockade decreased decorin and TGF-β1 in UVB-irradiated mice compared to UVB alone. MMP13 was inhibited by etanercept in UVB-irradiated mice (p < 0.01). In conclusion, blockade of TNFα significantly decreased mature collagen in UVB-irradiated mice, while increasing collagen fragmentation and decreasing procollagen.

Direct-Acting Antiviral Therapy Not Associated With Recurrence of Hepatocellular Carcinoma in a Multicenter North American Cohort Study

BACKGROUND & AIMS

There is controversy over the effects of direct-acting antiviral (DAA) therapies for hepatitis C virus (HCV) infection on hepatocellular carcinoma (HCC) recurrence and tumor aggressiveness. We compared HCC recurrence patterns between DAA-treated and untreated HCV-infected patients who had achieved a complete response to HCC treatment in a North American cohort.

METHODS

We conducted a retrospective cohort study of patients with HCV-related HCC with a complete response to resection, local ablation, transarterial chemo- or radioembolization, or radiation therapy from January 2013 through December 2017 at 31 health systems throughout the United States and Canada. Cox regression was used to examine the association between DAA therapy and time to recurrence after a complete response, with DAA therapy analyzed as a time-varying exposure. We also estimated the association between DAA therapy and risk of early HCC recurrence (defined as 365 days after complete response).

RESULTS

Of 793 patients with HCV-associated HCC, 304 (38.3%) received DAA therapy and 489 (61.7%) were untreated. HCC recurred in 128 DAA-treated patients (42.1%; early recurrence in 52 patients) and 288 untreated patients (58.9%; early recurrence in 227 patients). DAA therapy was not associated with HCC recurrence (hazard ratio 0.90, 95% confidence interval 0.70-1.16) or early HCC recurrence (hazard ratio 0.96, 95% confidence interval 0.70-1.34) after we adjusted for study site, age, sex, Child-Pugh score, α-fetoprotein level, tumor burden, and HCC treatment modality. In DAA-treated and untreated patients, most recurrences were within the Milan criteria (74.2% vs 78.8%; P = .23). A larger proportion of DAA-treated than untreated patients received potentially curative HCC therapy for recurrent HCC (32.0% vs 24.6%) and achieved a complete or partial response (45.3% vs 41.0%) but this did not achieve statistical significance.

CONCLUSION

In a large cohort of North American patients with complete response to HCC treatment, DAA therapy was not associated with increased overall or early HCC recurrence. HCC recurrence patterns, including treatment response, were similar in DAA-treated and untreated patients.

Sustained Virological Response Is Associated with a Decreased Risk of Posttransplant Diabetes Mellitus in Liver Transplant Recipients with Hepatitis C-Related Liver Disease

Posttransplant diabetes mellitus (PTDM), an increasingly recognized complication of solid organ transplantation, is associated with increased morbidity and mortality following liver transplantation (LT). Hepatitis C virus (HCV) infection is a consistent and modifiable risk factor for PTDM. Prior studies have demonstrated improvement in glucose metabolism following sustained virological response (SVR). However, the effect of SVR on the incidence of PTDM has not been previously investigated in a large cohort of LT recipients. We performed a single-center retrospective cohort study of LT recipients with HCV from January 1, 2010 to June 30, 2015 to compare the risk of sustained posttransplant diabetes mellitus (s-PTDM) prior to and following SVR. SVR was treated as a discrete time varying exposure. The s-PTDM was defined as de novo diabetes mellitus following LT of a >6-month duration. Univariate and multivariate Cox proportional hazards models were used to compare crude and adjusted time to s-PTDM prior to and following SVR. There were 256 eligible LT recipients analyzed. Median follow-up was 41.2 months. Overall, 31 (12.1%) and 178 (69.5%) patients achieved SVR prior to LT and following LT, respectively. During follow-up, 71 (27.7%) patients developed s-PTDM. The incidence of s-PTDM was greatest in the first year after LT. After adjustment for potential confounders, SVR was associated with a significantly reduced risk of s-PTDM (HR, 0.40; P = 0.048). In conclusion, eradication of HCV is independently associated with a reduced incidence of s-PTDM. This benefit appears to be most influenced by pre-LT SVR and persists throughout the post-LT period. Given the association between PTDM and posttransplant morbidity and mortality, these data provide another motivator for pre-LT or early post-LT treatment of HCV.

Neutrophil-to-Lymphocyte Ratio Associates Independently With Mortality in Hospitalized Patients With Cirrhosis

BACKGROUND & AIMS

The neutrophil to lymphocyte ratio (NLR) is a biomarker of immune dysregulation in patients with cirrhosis and is inexpensive to measure. We investigated the association between NLR and mortality in hospitalized patients with cirrhosis at 4 liver transplant centers, controlling for severity of acute-on-chronic liver failure (ACLF).

METHODS

We performed a retrospective study using data from the North American Consortium for the Study of End-stage Liver Disease on patients with index hospitalizations for cirrhosis from December 2011 through December 2016. We collected data on patient demographics, NLR, model for end-stage liver disease (MELD) scores, serum levels of Na, cirrhosis stages, infections, hepatocellular carcinomas, and ACLF severity (based on number of organ failures). Competing risk regression analysis evaluated mortality within 1 year after hospital discharge, accounting for competing events (liver transplant).

RESULTS

At admission, the patients' mean age was 57 years, mean MELD score was 21, and mean serum level of Na was 134 mmol/L. Sixty-eight patients had no organ failure, 21 patients had 1 organ failures, 7 patients had 2 organ failures, 4 patients had 3 organ failures, and 1 patient had 4 organ failures; 36% of the patients had confirmed or suspected infections. In univariate models, risk of death associated with increasing NLR, up to a value of 8 (hazard ratio [HR]= 1.14; 95% CI, 1.07-1.20; P < .001), and NLR quartile (for NLR range of 3-5, HR = 2.17; for NLR range of >5-9, HR=2.46; for NLR quartile >9, HR=2.84 vs the lowest quartile [NLR<3]) (P ≤ .001). The NLR remained statistically significant in multivariable models, adjusting for age, MELD score, hepatocellular carcinoma, and ACLF severity. Additionally, NLR was a statistically significant independent predictor of length of index hospital stay and mortality within 90 days after discharge.

CONCLUSION

In a retrospective analysis of patients with cirrhosis, we found NLR to associate with death within 1 year after non-elective hospitalization. In these patients, the risk of death associated with acute immune dysregulation persists long after their initial hospitalization.

Advances in HCV and Cryoglobulinemic Vasculitis in the Era of DAAs: Are We at the End of the Road?

Hepatitis C Virus (HCV)-related Mixed Cryoglobulinemia (MC) is a unique condition with complex pathogenesis that involves HCV antigen-driven B-lymphocyte clonal proliferation and mutagenesis. Clinical spectrum of MC ranges from asymptomatic state to clinically-apparent vasculitis involving multiple organs. In the era of Direct-Acting Antiviral (DAA) therapy, patients with HCV-related MC achieve high rates of viral clearance that is commonly accompanied by an improvement in clinical symptoms as well as immunological profiles. Rituximab, either alone or in combination with DAA, has also been shown to be effective. Nevertheless, there have been limited and somewhat conflicting data, particularly over the long-term, regarding the rate and degree of clinical response of MC following DAA therapy. It appears that we have come quite a long way in the last decade with this condition. As with non-MC related HCV, undoubtedly long term outcome data will be forthcoming over the next few years. As we move forward successful therapy of HCV is not likely to be a challenge in contrast to access to therapy.

Hepatitis C virus therapy with peg-interferon and ribavirin in Myanmar: A resource-constrained country

AIM

To investigate peg-interferon (peg-IFN) and ribavirin (RBV) therapy in Myanmar and to predict sustained virologic response (SVR).

METHODS

This single-center, open-label, study was conducted in Myanmar between 2009 and 2014. A total of 288 patients infected with HCV genotypes 1, 2, 3 and 6 were treated with peg-IFN alpha-2a (180 μg/wk) or alpha-2b (50 to 100 μg as a weight-based dose) and RBV as a weight-based dose (15 mg/kg/d). Treatment duration was 48 wk for genotypes 1 and 6, 24 wk for genotype 2, and 24 or 48 wk for genotype 3 based on rapid virologic response (RVR). Those co-infected with hepatitis B received 48 wk of therapy.

RESULTS

Overall, SVR was achieved for 82% of patients and the therapy was well tolerated. All patients achieved SVR at equivalent rates regardless of HCV genotype (P = 0.314). Low fibrosis scores (P < 0.001), high baseline albumin levels (P = 0.028) and low baseline viral loads (P = 0.029) all independently predicted SVR. On the other hand, IL-28B TT and CC genotypes were not found to significantly predict SVR (P = 0.634; P = 0.618). Among those who completed treatment, the occurrence of RVR showed a > 96% positive predictive value for achieving SVR. Treatment duration did not significantly impact the likelihood of achieving SVR for patients infected with genotype 3 HCV (P = 0.371). The most common adverse events were fatigue (71%) and poor appetite (60%). Among patients with genotype 3 HCV, more patients in the 48-wk treatment group required erythropoietin than in the 24-wk treatment group (61.1% vs 49.2%).

CONCLUSION

SVR rates were high with peg-IFN and RBV therapy in Myanmar. Fibrosis scores, baseline albumin, HCV RNA levels and RVR independently predicted SVR.

Alternative uses of a visible light-polymerized material

Three different procedures that involve the use of Triad gel are described. This light-polymerized resin material is versatile and easy to use in the dental clinic and laboratory. The procedures described include the transfer of ridge topography for ovate pontic sites, implant lab analog fixation, and solid/soft tissue cast fabrication.

Alternative uses of a visible light-polymerized material

Three different procedures that involve the use of Triad gel are described. This light-polymerized resin material is versatile and easy to use in the dental clinic and laboratory. The procedures described include the transfer of ridge topography for ovate pontic sites, implant lab analog fixation, and solid/soft tissue cast fabrication.

Accuracy of electronic implant torque controllers following time in clinical service

Tightening of the screws in implant-supported restorations has been reported to be problematic, in that if the applied torque is too low, screw loosening occurs. If the torque is too high, then screw fracture can take place. Thus, accuracy of the torque driver is of the utmost importance. This study evaluated 4 new electronic torque drivers (controls) and 10 test electronic torque drivers, which had been in clinical service for a minimum of 5 years. Torque values of the test drivers were measured and were compared with the control values using a 1-way analysis of variance. Torque delivery accuracy was measured using a technique that simulated the clinical situation. In vivo, the torque driver turns the screw until the selected tightening torque is reached. In this laboratory experiment, an implant, along with an attached abutment and abutment gold screw, was held firmly in a Tohnichi torque gauge. Calibration accuracy for the Tohnichi is +/- 3% of the scale value. During torque measurement, the gold screw turned a minimum of 180 degrees before contact was made between the screw and abutment. Three torque values (10, 20, and 32 N-cm) were evaluated, at both high- and low-speed settings. The recorded torque measurements indicated that the 10 test electronic torque drivers maintained a torque delivery accuracy equivalent to the 4 new (unused) units. Judging from the torque output values obtained from the 10 test units, the clinical use of the electronic torque driver suggests that accuracy did not change significantly over the 5-year period of clinical service.

Implant management for comprehensive occlusal reconstruction

Implant prosthodontics is a predictable treatment modality for patients who require occlusal reconstruction. Specific indications include lack of distal abutment, long span segment, compromised natural abutments, and occlusal dysfunction. With proper treatment planning and an understanding of the occlusion and biomechanics of implant prosthodontics, the restorative team can predictably fabricate a functional, esthetic, and comfortable prosthesis.

Restorative dentistry using a multidisciplinary approach

Multidisciplinary treatment was essential for this patient to optimally manage the occlusion and missing teeth. When the space distribution was completed, ridge management procedures for pontic site development were accomplished. The final restorative treatment required was actually minimized to a 7-unit fixed partial denture. It was apparent the multidisciplinary treatment was essential to predictably manage this patient by decreasing risk and ensuring a long-term strategy for enhanced patient satisfaction.

Measurement of heart rate variability: a clinical tool or a research toy?

The objectives of this review are to discuss the diversity of mechanisms that may explain the association between heart rate (HR) variability and mortality, to appraise the clinical applicability of traditional and new measures of HR variability and to propose future directions in this field of research. There is a large body of data demonstrating that abnormal HR variability measured over a 24-h period provides information on the risk of subsequent death in subjects with and without structural heart disease. However, the mechanisms responsible for this association are not completely established. Therefore, no specific therapy is currently available to improve the prognosis for patients with abnormal HR variability. Reduced HR variability has been most commonly associated with a risk of arrhythmic death, but recent data suggest that abnormal variability also predicts vascular causes of death, progression of coronary atherosclerosis and death due to heart failure. A consensus is also lacking on the best HR variability measure for clinical purposes. Time and frequency domain measures of HR variability have been most commonly used, but recent studies show that new analysis methods based on nonlinear dynamics may be more powerful in terms of risk stratification. Before the measurement of HR variability can be applied to clinical practice and used to direct therapy, more precise insight into the pathophysiological link between HR variability and mortality are needed. Further studies should also address the issue of which of the HR variability indexes, including the new nonlinear measures, is best for clinical purposes in various patient populations.

Cycling of inducibility of paroxysmal supraventricular tachycardia in women and its implications for timing of electrophysiologic procedures

Arrhythmias in women may be affected by phases of the menstrual cycle. This study was designed to determine the prevalence of perimenstrual clustering of spontaneous episodes of paroxysmal supraventricular tachycardia (SVT) in women. It also tested the hypothesis that women with this temporal pattern of events have an altered probability of induction of paroxysmal SVT during electrophysiologic testing at higher estrogen states (midcycle or with estrogen replacement therapy) than at low estrogen states (perimenstrual or without estrogen replacement). A structured history of the relation of spontaneous paroxysmal SVTs to phases of the menstrual cycle was obtained prospectively among 42 women referred during a 3-year period. Patients with cyclical patterns of spontaneous tachycardias, who had had negative electrophysiologic studies at midcycle or while receiving estrogen replacement therapy, had repeat procedures (1) when premenstrual or at the onset of menses, or (2) after stopping estrogen replacement therapy. Seventeen of 42 consecutive female patients (40%) had histories of perimenstrual clustering of arrhythmias. Six women (4 with normal menstrual cycles, 2 on estrogen replacement therapy), who qualified for paired electrophysiologic studies because of a negative initial electrophysiologic study that included provocation with isoproterenol, had inducibility into SVTs during the second study. All 6 had dual atrioventricular (AV) nodal pathway physiology, 4 had AV nodal reentrant tachycardia (AVNRT) induced, 1 had both AVNRT and reciprocating AV tachycardias, and 1 had nonsustained AVNRT and an atrial tachycardia induced. Successful ablation procedures were performed in 5 of the 6 patients. Thus, among women with a history of perimenstrual clustering of paroxysmal SVT and among those receiving estrogen replacement therapy, scheduling of elective electrophysiologic procedures at times of low estrogen levels (premenstrual or off estrogen replacement therapy) may facilitate the probability of a successful procedure.

The effects of ionizing radiation on the dividing cells of the conjunctival epithelium

The influence of an X-ray dose of 10 Gy (1000 rads) on mitosis in the rat conjunctival epithelium was assessed. A mitotic inhibition began 1 hour postirradiation and continued for 4 days. The mitotic index was depressed to 10% of control values. After 5 days postirradiation, the mitotic index surpassed the control values peaking at 7 days postirradiation. The spindle axes of cells in telophase of the perilimbal rat conjunctival epithelium assume a characteristic, three dimensional orientation relative to the limbus. Ionizing radiation did not disrupt this organization at any time postirradiation. In fact, the frequency of mitotic figures preferentially aligned in irradiated tissue was enhanced during the mitotic rebound.