THE SOLVENT ACTION OF ANTISEPTICS ON NECROTIC TISSUE

1. Dakin''s hypochlorite solution has the power of dissolving necrotic tissue, pus, and plasma clot in the concentration and reaction used clinically. 2. Chloramine-T and dichloramine-T do not exhibit this action. 3. The solvent action of Dakin''s hypochlorite solution of the degree of alkalinity used clinically is due primarily to its hypochlorite content, but its slight alkalinity, while in itself without solvent action, enhances the effectiveness of the hypochlorite. 4. In the degree of alkalinity used clinically, the solvent action of hypochlorite is absent below about 0.2 per cent sodium hypochlorite concentration. 5. The hypochlorite concentration at which the solvent action ceases is lower the more alkaline the solution, and vice versa. 6. None of the antiseptics studied had demonstrable solvent action on blood clot.     

THE RELATION OF THE SPLEEN TO BLOOD DESTRUCTION AND REGENERATION AND TO HEMOLYTIC JAUNDICE : XII. THE IMPORTANCE IN THE PRODUCTION OF HEMOLYTIC JAUNDICE OF THE PATH OF HEMOGLOBIN TO THE LIVER.

These experiments indicate, therefore, that when hemoglobin is set free in the portal circulation a larger amount is held by the liver and converted rapidly into bile pigment than is the case when it is set free in the general circulation, and that, under the former condition, over-loading of the liver with bile pigment more readily occurs and jaundice is more apt to develop. This mechanical influence must, therefore, be a factor in the lessened tendency after splenctomy to the jaundice which follows blood destruction due to hemolytic agents, for whether the spleen be an active factor in destroying the erythrocytes or whether it plays merely a passive part as a place for the deposition of the disintegrating cells, there can be no question that in this organ, when it is present, a large number of cells undergo their final disintegration after the action of hemolytic poisons, and that the hemoglobin there liberated passes by the portal system directly to the liver. When the spleen is removed, this disintegration occurs in other organs, notably in the lymph nodes and bone marrow, and the hemoglobin from these organs passes not into the portal but into the general circulation, from which it reaches the liver more gradually and in a more dilute form.     

THE RELATION OF THE SPLEEN TO BLOOD DESTRUCTION AND REGENERATION AND TO HEMOLYTIC JAUNDICE : V. CHANGES IN THE ENDOTHELIAL CELLS OF THE LYMPH NODES AND LIVER IN SPLENECTOMIZED ANIMALS RECEIVING HEMOLYTIC SERUM.

In a large proportion of dogs that have been splenectomized for periods of two weeks or more, one finds a great increase in the number of endothelial cells of the lymph nodes. In most splenectomized dogs that succumb to an injection of hemolytic immune serum within forty-eight hours, the sinuses of the lymph nodes contain large numbers of endothelial cells, phagocytic for red cells. This is not seen in normal dogs receiving hemolytic serum. Likewise a similar power of phagocytosis is seen frequently in the stellate cells of the capillaries of the liver. Both in the lymph nodes and the liver these cells appear to be formed in situ; we find no evidence that they have been transported to these organs. Such findings suggest the development of a compensatory function on the part of the lymph nodes and possibly of the liver. Normally the spleen contains cells which have the power to engulf and presumably to destroy the red blood corpuscles. In certain pathological conditions this function is frequently greatly augmented and may sometimes be shared by the lymph nodes, for example, in typhoid fever, as was first clearly shown by Mallory. Our observations suggest that in the absence of the spleen, this function of forming red blood corpuscle-phagocyting cells, normally a minor activity of the lymph nodes, becomes highly developed in the latter organs, and that these cells, and the stellate cells of the liver, thus assume, in part at least, the function of destroying red blood corpuscles by phagocytosis. In view of the somewhat limited material at our disposal, we offer this, not as definitely conclusive, but as evidence which, in connection with the work of others, is highly suggestive of the possibility of the lymph nodes assuming some of the function of the spleen. Whether this activity of the endothelial cells of the lymph nodes and the liver has any bearing on the anemia that follows splenectomy and on the occurrence of spontaneous jaundice in the late periods after splenectomy, is not yet clear.     

Comparing the performance of propensity score methods in healthcare database studies with rare outcomes

Nonrandomized studies of treatments from electronic healthcare databases are critical for producing the evidence necessary to making informed treatment decisions, but often rely on comparing rates of events observed in a small number of patients. In addition, studies constructed from electronic healthcare databases, for example, administrative claims data, often adjust for many, possibly hundreds, of potential confounders. Despite the importance of maximizing efficiency when there are many confounders and few observed outcome events, there has been relatively little research on the relative performance of different propensity score methods in this context. In this paper, we compare a wide variety of propensity‐based estimators of the marginal relative risk. In contrast to prior research that has focused on specific statistical methods in isolation of other analytic choices, we instead consider a method to be defined by the complete multistep process from propensity score modeling to final treatment effect estimation. Propensity score model estimation methods considered include ordinary logistic regression, Bayesian logistic regression, lasso, and boosted regression trees. Methods for utilizing the propensity score include pair matching, full matching, decile strata, fine strata, regression adjustment using one or two nonlinear splines, inverse propensity weighting, and matching weights. We evaluate methods via a ‘plasmode’ simulation study, which creates simulated datasets on the basis of a real cohort study of two treatments constructed from administrative claims data. Our results suggest that regression adjustment and matching weights, regardless of the propensity score model estimation method, provide lower bias and mean squared error in the context of rare binary outcomes. Copyright © 2017 John Wiley & Sons, Ltd.     

Risky Party and Nightclub Attendance during the COVID-19 Nightlife Shutdown in New York City

From March 2020 through May 2021, nightlife venues were shut down and large gatherings were deemed illegal in New York City (NYC) due to COVID-19. This study sought to determine the extent of risky party attendance during the COVID-19 shutdown among people who attend electronic dance music parties in NYC. During the first four months that venues were permitted to reopen (June through September 2021), time–space sampling was used to survey adults (n = 278) about their party attendance during the first year of the shutdown (March 2020–March 2021). We examined prevalence and correlates of attendance and mask-wearing at such parties. A total of 43.9% attended private parties with more than 10 people, 27.3% attended nightclubs, and 20.5% attended other parties such as raves. Among those who attended any, 32.3% never wore a mask and 19.3% reported attending parties in which no one wore a mask. Past-year ecstasy use was associated with increased risk for attending private (aPR = 1.51, 95% CI: 1.00–2.28) or other parties (aPR = 2.75, 95% CI: 1.48–5.13), and use of 2C series drugs was associated with increased risk for attending nightclubs (aPR = 2.67, 95% CI: 1.24–5.77) or other parties (aPR = 2.50, 95% CI: 1.06–5.87). Attending >10 parties was associated with increased risk for never wearing a mask (aPR = 2.74, 95% CI: 1.11–6.75) and for no other attendees wearing masks (aPR = 4.22, 95% CI: 1.26–14.07). Illegal dance parties continued in NYC during the COVID-19 shutdown. Prevention and harm reduction efforts to mitigate risk of COVID-19 transmission during such shutdowns are sorely needed.     

Efficiency of neuromuscular electrical stimulation: A comparison of elicited force and subject tolerance using three electrical waveforms

Objective: Efficacy of neuromuscular electrical stimulation (NMES) is limited by the discomfort of electrically elicited contractions. Most studies of tolerance to NMES have examined stimulation to maximal tolerance. NMES efficiency is the amount of elicited force at a specific level of tolerance. This study is the first to describe and examine such. Design: A repeated measures design was used. Electrically elicited force (EEF) was measured using three waveforms: burst-modulated alternating current (BMAC), pulsed current (PC), and burst-modulated pulsed current (BMPC). EEF at a tolerance rating of 5/10 on a visual analog scale (VAS) was recorded. The dependent variables were EEF up to 5/10 VAS, current amplitude at 5/10, and percent maximal isometric force at 5/10. Results: EEF and percent maximal voluntary isometric force were significantly greater with BMPC versus BMAC (p = 0.001 and 0.004). No differences were noted between PC and BMAC or BMPC and PC. Amplitude was significantly greater with BMAC compared to BMPC and PC (p = 0.003 and 0.015). No difference in amplitude was noted between PC and BMPC. Conclusion: For the same level of discomfort, BMPC yielded one-third greater muscle force than BMAC and at a lesser current amplitude. These data evidence a greater efficiency for BMPC than BMAC.     

Increasing dietary EPA and DHA influence estimated fatty acid desaturase activity in systemic organs which is reflected in the red blood cell in mice

Delta-5 (D5D) and delta-6 (D6D) desaturase are key enzymes in fatty acid (FA) metabolism. Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may alter tissue FA composition via D5D and D6D. The purpose was to determine the relationship between dietary EPA?+?DHA, estimated desaturase activities of various tissues and the reflection of desaturase activity in the red blood cell (RBC). Mice were fed diets with increasing percent of energy from EPA?+?DHA. Phospholipid FA composition of heart, muscle, spleen, lung, adipose tissues and RBC were analysed. D5D and D6D enzyme activity estimates (EAE) were calculated as the ratio of 20:4/20:3 and 20:3/18:2, respectively. D5D EAE decreased in all tissues, except muscle, with increasing dietary EPA?+?DHA. RBC D5D EAE positively correlated with D5D EAE in all tissues. RBC D6D EAE positively correlated with muscle and inversely correlated with adipose D6D EAE. Our findings suggest differential influence of dietary EPA?+?DHA upon tissue desaturase activities.     

Antidepressant Use is Associated with Increased Energy Intake and Similar Levels of Physical Activity

Antidepressants have been associated with weight gain, but the causes are unclear. The aims of this study were to assess the association of antidepressant use with energy intake, macronutrient diet composition, and physical activity. We used data on medication use, energy intake, diet composition, and physical activity for 3073 eligible adults from the 2005–2006 National Health and Nutrition Examination Survey (NHANES). Potential confounding variables, including depression symptoms, were included in the models assessing energy intake, physical activity, and sedentary behavior. Antidepressant users reported consuming an additional (mean ± S.E.) 215 ± 73 kcal/day compared to non-users (p = 0.01). There were no differences in percent calories from sugar, fat, or alcohol between the two groups. Antidepressant users had similar frequencies of walking or biking, engaging in muscle-strengthening activities, and engaging in moderate or vigorous physical activity. Antidepressant users were more likely to use a computer for ≥2 h/day (OR 1.77; 95% CI: 1.09–2.90), but TV watching was similar between the two groups. These results suggest increased energy intake and sedentary behavior may contribute to weight gain associated with antidepressant use. Focusing on limiting food intake and sedentary behaviors may be important in mitigating the weight gain associated with antidepressant use.