Morphology of cardiac muscle in septic shock. Observations with a porcine septic shock model

The morphology of cardiac muscle was investigated in a porcine model of septic shock, created by intermitted application of Escherichia coli-endotoxin. The earliest lesions, found after 18 h of septic shock, were endothelial cell swelling, marked leucostasis and slight ischaemic alterations of the muscle fibres. At the end point of the experiments, after 48 h, some fibrin thrombi were found associated with more pronounced ischaemic alterations of cardiac muscle cells and some necrotic fibres. Comparing these findings with the severe endothelial and muscle fibre lesions found in skeletal muscle, the endothelial cells of the heart microvasculature, are clearly more resistant to the attack of the endotoxins and mediators liberated in septic shock.     

A photoetched cell relocation matrix for long-term, quantitative observations of selected individual neurons in culture

A photoetched matrix of indium tin oxide (ITO) on glass has been developed and tested as a tool to assist in the relocation and identification of individual neuronal cells in culture. The matrix is formed by 10-15 micron wide and 300 A thick ITO lines which subdivide a 1-cm2 area into 625 smaller squares. Each of the smaller squares measures 400 micron on a side and contains a photoetched two-letter "address". The address code allows precise relocation of specific regions of a culture as well as verification of the identities of individual neurons selected for repeated observation. Marks at 50 micron intervals along the sides of the address squares permit quantitative analysis of morphological changes, cell migration, reaggregation, etc. The ITO is transparent and does not interfere with visualization of even fine details of cells with high power microscopy.     

Swine flu vaccine and multiple sclerosis

Using age-specific rates for multiple sclerosis (MS) based on a national survey, the number of "naturally occurring" new cases of MS among the 45 million swine flu vaccine recipients in the United States is estimated as 1,624 during the year after vaccination, or 31 cases per week. Information from available reports and publications indicates no excess over the expected frequencies. Analyses of admissions for MS before, during, and after the immunization program showed no increase to the US Army hospitals or to the Mayo Clinic. Three independent controlled clinical investigations performed on patients with MS showed no increase in the frequency of exacerbations among those receiving swine flu vaccine as compared with those receiving placebo. Epidemiologic features of MS do not implicate killed virus vaccine as an etiologic factor in onset or exacerbations of the disease. There is no indication from these analyses of any association or cause-and-effect relationship between swine flu vaccine and MS.     

Food insecurity among Canadian youth and young adults: insights from the Canada Food Study

ObjectiveThis study explored associations between socio-demographic characteristics, self-reported health, and household food security among young adults.MethodsNational cohort study participants from Toronto, Montreal, Vancouver, Edmonton, and Halifax, Canada, aged 16–30 years (n = 2149) completed online surveys. Multinomial logistic regression, weighted to reflect age and sex proportions from the 2016 census, was conducted to examine associations between food security status and covariates.ResultsAlmost 30% of respondents lived in food-insecure households, with 19% in “moderately” food-insecure and 10% in “severely” food-insecure households. Respondents identifying as Black or Indigenous were more likely to live in moderately (AOR = 1.96, CI: 1.10, 3.50; AOR = 3.15, CI: 1.60, 6.20) and severely (AOR = 4.25, CI: 2.07, 8.74; AOR = 6.34, CI: 2.81, 14.30) food-insecure households compared with those identifying as mixed/other ethnicity. Respondents who found it “very difficult” to make ends meet were more likely to be moderately (AOR = 20.37, CI: 11.07, 37.46) and severely (AOR = 101.33, CI: 41.11, 249.77) food insecure. Respondents classified as “normal” weight (AOR = 0.64, CI: 0.43, 0.96) or overweight (AOR = 0.53, CI: 0.34, 0.83) were less likely to be moderately food insecure compared with those affected by obesity. Compared with “very good or excellent,” “poor” health, diet quality, and mental health were each positively associated with severe food insecurity (AOR = 7.09, CI: 2.44, 20.61; AOR = 2.63, CI: 1.08, 6.41; AOR = 2.09, CI: 1.03, 4.23, respectively).ConclusionThe high prevalence of correlates of food insecurity among young adults suggests the need for policies that consider the unique challenges (e.g., precarious income) and vulnerability associated with this life stage.     

Exploring the main and moderating effects of individual-level characteristics on consumer responses to sugar taxes and front-of-pack nutrition labels in an experimental marketplace

InterventionThis study examined whether the impacts of sugar taxes and front-of-pack (FOP) nutrition labels differ across socio-demographic subgroups.Research questionWhat are the main and moderating effects of individual-level characteristics on the nutrient content of participants’ purchases in response to varying taxation levels and FOP labels?MethodsData from an experimental marketplace were analyzed. A sample of 3584 Canadians aged 13 years and older received $5 to purchase an item from a selection of 20 beverages and 20 snack foods. Participants were shown products with one of five FOP labels and completed eight within-subject purchasing tasks with different tax conditions. Linear mixed models were used to estimate the main and moderating effects of 11 individual-level variables on the sugars, sodium, saturated fats, and calorie content of participants’ purchases.ResultsParticipants who were younger, male, and more frequent consumers of sugary drinks purchased products containing more sugars, sodium, saturated fats, and calories. Sex and age moderated the relationship between tax condition and sugars or calories purchased: female participants were more responsive than males to a tax that included fruit juice, and younger participants were more responsive to all sugar tax conditions than older participants. Reported thirst and education level also moderated the relationship between tax condition and calories purchased. No individual-level characteristics moderated the effects of FOP labels.ConclusionA small proportion (7 of 176) of the moderating effects tested in this study were significant. Sugar taxes and FOP labelling policies may therefore produce similar effects across key socio-demographic groups.Supplementary InformationThe online version contains supplementary material available at 10.17269/s41997-021-00475-x.     

Anhedonia and the deficit syndrome of schizophrenia

Schizophrenic outpatients with and without the deficit syndrome were administered Chapman's "psychosis proneness" scales. As hypothesized, deficit syndrome patients had higher scores on Social Anhedonia and Physical Anhedonia, but did not differ from nondeficit patients on Perceptual Aberration, Magical Ideation, or Impulsive Nonconformity. The differences between the two groups were not related to race, gender, age, socioeconomic status of family of origin, or drug treatment. These results support the validity of the deficit syndrome, and suggest that the Social Anhedonia and Physical Anhedonia scales may be useful in future studies of schizophrenia.     

Late-systolic pumping properties of the left ventricle. Deviation from elastance-resistance behavior

Elastance-resistance [E(t)-R] representations of the left ventricle (LV) were evaluated for their ability to reproduce instantaneous pressure [P(t)] and outflow [Q(t)]. Experiments were performed in open-chest rats. P(t) and Q(t) were measured during steady-state ejecting beats and during a beat in which the aorta was suddenly clamped. The degree of clamping varied from partial to total occlusion. The total occlusion beat was considered an isovolumic beat that generated an isovolumic pressure [Piso(t)] with a characteristic time to maximal Piso(t) [Tpisomax]. In ejecting beats, 34% of stroke volume was delivered after Tpisomax. P(t) and Q(t) from the steady-state ejecting beats and Piso(t) from the clamped beat were then used to estimate parameters of an E(t)-R model. Components of P(t) and Q(t) not accounted for by E(t)-R were identified and termed extra-pressure [Pext(t)] and extra-outflow [Qext(t)]. Pext(t) and Qext(t) were near-zero valued until Tpisomax; then they became systematically positive and finally negative valued after end ejection. During partial aortic occlusion, P(t) was elevated and Q(t) was reduced. However, the time of ejection was extended, and the fraction of stroke volume delivered after Tpisomax increased as P(t) was made higher. Partial occlusion also prolonged the positive phase of Pext(t) and Qext(t). Elements possessing "active" and "deactive" properties were added to the E(t)-R model in an attempt to account for Pext(t) and Qext(t) during partial occlusion. Optional forms of these elements were considered. These expanded E(t)-R models were fitted to basal ejecting data and then asked to predict data from a partial occlusion beat. All expanded models failed to adequately predict the partial occlusion pressure and/or outflow. It was concluded that 1) late ejection was quantitatively important to LV pumping, 2) behavior during late ejection was inconsistent with E(t)-R, and 3) ad hoc modification of E(t)-R models was not likely to yield LV pumping models that could satisfactorily reproduce instantaneous P(t) and Q(t) behavior over the entire ejection period.     

Septischer Schock und multiples Organversagen in der chirurgischen Intensivmedizin

Zusammenfassung Beschrieben wird ein tierexperimentelles Sepsismodell, das der Problematik chirurgischer Intensivpatienten entspricht. Nach rezidivierender Applikation von E.-coli-Endotoxin W0111:134 unter standardisierten Bedingungen konnten spezifische hämodynamische, biochemische (TNF, TXA₂, PG I₂, IL-6, PAF) und morphologische Veränderungen (pulmonales Endothel) nachgewiesen werden. Die sepsisinduzierten ARDS-Veränderungen werden mit einer Hochfrequenzdruck-und-flowmessung mit 385 Meßpunkten fiber einem Atemzyklus analysiert. Die Rolle des Darms in der Sepsis wurde mit ionenselektivem Kaliummonitoring vergleichend auf der Mukosa and Serosa untersucht. Jede Endotoxingabe wurde vom Dünndarm mit selektiven Anstiegen der Kaliumaktivität als Ausdruck einer Endotoxin-induzierten relativen Ischämie beantwortet. Das Profil der Oberflächenkaliumwerte korreliert sowohl mit dem cardiaco output als auch mit den Prostazyklinspiegeln. Die während der Versuchsdauer kontinuierlich abnehmende Mukosa-Serosa-Kaliumdifferenz kann als Nachweis einer die Sepsis katalysierenden intestinalen Permeabilitätsstörung interpretiert werden.

---

Septic shock and multiple organ failure during surgical intensive care. Evaluation of pulmonary and intestinal dysfunction assessment in a porcine model

The study deals with an animal model for the problems of surgical intensive care patients. Following repeated applications of E. coli endotoxin W0111:134 under standard conditions, specific hemodynamic and biochemical (TNF, TXA₂, PGI₂, IL-6, PAF) and morphological (endothelium of the lung) alterations were detected. ARDS patterns induced by the sepsis were analyzed by high-frequency measurement of pressure and flow (385 measurements per breathing cycle). The role of the intestine in sepsis was investigated by ion-selective monitoring of surface potassium activity comparing mucosa and serosa. Every injection of endotoxin was followed by a selective increase of the potassium activity revealing relative ischemia induced by the endotoxin. The profile of the potassium levels on the surface correlates both with the cardiac output and with the prostacyclin levels. The continuous narrowing of the difference between mucosa and serosa, potassium during the period of investigation can be regarded as evidence for pathologic change in permeability fostering the septic course.

     

Alterations in respiratory mechanics after laparoscopic and open surgical procedures

Objective

To compare the effects of laparoscopic and open surgical procedures on postoperative strength and respiratory mechanics.

Design

Prospective cohort study.

Setting

Adult university hospital.

Participants

Fifty-one women aged 21 to 62 years scheduled to undergo elective cholecystectomy or hysterectomy (or related procedures), otherwise in good health.

Intervention

Open or laparoscopic cholecystectomy or hysterectomy (or related procedures).

Main Outcome Measures

Maximum voluntary handgrip strength (HGS), forced vital capacity (VC), forced expiratory volume in 1 second (FEV₁), and maximal inspiratory pressure (MIP) were each measured preoperatively and on the first postoperative morning. A visual analogue pain scale score was evaluated in relation to performance of the postoperative strength and respiratory measurements.

Results

VC, FEV₁ and MIP, but not HGS, were decreased after surgery. Postoperative VC, FEV₁ and MIP were lower after open procedures than after laparoscopic procedures and after cholecystectomy than after hysterectomy (all p < 0.001). Pain scores were lower after laparoscopic than after open procedures (p < 0.005) and could account in part for differences in postoperative respiratory mechanics.

Conclusions

Cholecystectomy and hysterectomy do not result in generalized muscle weakness, unlike more major abdominal procedures. Postoperative alterations in respiratory mechanics are related to the site of the surgery, the use of an open versus a laparoscopic approach and postoperative pain.     

Back to the future for wound care?

The European Renaissance was a time of enormous change and rapid progress in the arts, sciences, and medicine. A glimpse of wound care in the last phase of the European Renaissance is provided by the analysis of work by Wilhelm Fabry, the "father of German surgery," as provided in his book De Combustionibus ("Burns") which details his range of treatments for the burn wound, as well as his approach to the later problems of scarring and contracture. We describe some of the historic events which may have stimulated Fabry's writings, in particular, the influences passed down from the medical school of Padua which thereby advanced the cause of wound care and surgery. Finally, we briefly explore the potential of such an approach to the works of our medical forefathers.