3-Dimensional Cervical Movement Characteristics and the Influence of Thoracic Treatment on a Subgroup of Acute Neck Pain Patients

Objective

The purpose of this study was to investigate the influence of thoracic high-velocity low-amplitude thrust (HVLAT) manipulation on quantitative and qualitative 3-dimensional cervical spine kinematic patterns in a subgroup of patients with acute neck pain.

P-R interval in relation to heart rate during exercise and the influence of posture and autonomic tone

P-R interval (PR) in relation to heart rate (HR) during exercise was studied in healthy men. When subjects were in a recumbent position, mean PR between HR 90–140 beats/min (bpm) decreased linearly from 167±8 ms to 136±5 ms. (Regression line: PR=0.287 HR +182.9, r=0.40). PR did not decrease further at HR up to 180 bpm. When subjects were in a sitting position, a further decrease occurred after HR 150–160 bpm. The shortest PR observed during exercise was 100 ms. The decrease of PR between HR 90–140 bpm was affected by atropine but not by propranolol. Higher HR was not achieved after propranolol, and after atropine there was no difference in PR in either exercise position compared to the two exercises without any drug. Thus, exercise induces a decrease in PR which is for the most part completed at HR 140–150 bpm and is mainly achieved by a withdrawal of the parasympathetic tone. PR at HR 90 bpm was correlated to body surface area, indicating that the PR duration is related to the body and heart dimensions.     

Changes in the microvasculature with age

The microvasculature of various organs of the rat and of the mesentery of the cat were examined for histochemical changes as a function of age, using the periodic acid-Schiff (PAS) reaction. Arterioles, minute arteries, and nonmuscular venules were histochemically unchanged to approximately 17 months of age in the rat and 8 years in the cat. Subsequently, focal areas of PAS-positive material developed in the media of arterioles and small arteries and increased in extent and severity with age. The adventitia of nonmuscular venules normally stains slightly positive due to the mucopolysaccharide coating of collagen fibers. With age this adventitial layer becomes more intensely PAS-positive. In the 26-month-old rat and 19-year-old cat, the media of arterioles and small arteries were extensively hyalinized. Lesions of arteriosclerosis were not present. These observations, in consort with prior observations of others in various mammals, indicate that there is a regular systematic alteration of various elements of the microcirculation with age. A possible relationship between these anatomical changes and tissue exchange is considered.     

Urinary excretion and efflux from the leg of 3-methylhistidine before and after major surgical operation

Changes in the effluxes from the leg of 3-methylhistidine and tyrosine were studied in relation to alterations in the 24-hour excretion of 3-methylhistidine and total nitrogen in 11 patients before and after undergoing major surgical operation. On the first day after operation, efflux of 3-methylhistidine from the leg was significantly decreased by 40% compared to preoperative values. In contrast, tyrosine efflux was doubled at the same time as a transient 20% increase in oxygen uptake of the leg and a marked increase in catecholamine excretion were observed. These changes coincided with a 40% elevation in the excretion of both 3-methylhistidine and nitrogen. Leg metabolism returned to the preoperative pattern within a week. These results suggest that the loss of amino acids from the lean tissues of the leg is the result of a fall in protein synthesis accompanied by an adaptive fall in protein breakdown. Although the increase in nitrogen excretion in response to major surgical trauma reflects the negative amino acid balance of skeletal muscle, the changes in urinary 3-methylhistidine do not correlate with changes in efflux of 3-methylhistidine from the leg. These results suggest that the use of 3-methylhistidine excretion as a specific index of skeletal muscle protein breakdown in postoperative patients may be invalid. Tissues other than skeletal muscle appear to make a substantial contribution to the 3-methylhistidine excretion postoperatively.     

Risk factors for 28-day mortality in patients with sepsis-related myocardial injury in intensive care units

ObjectiveThis study aimed to identify the risk factors for death in patients with sepsis-related myocardial injury.MethodsA retrospective study was conducted in 158 patients with sepsis-related myocardial injury in a mixed medical intensive care unit from January 2009 to March 2020. The patients were divided into those who survived and those who died on the basis of whether they survived after 28 days. Demographic and clinical parameters were collected. Multivariate logistic regression was performed.ResultsSixty-nine (43.7%) patients died within 28 days after admission to the intensive care unit. Multivariate logistic regression analysis showed that the oxygenation index (odds ratio [OR]: 0.979, 95% confidence interval [CI]: 0.970–0.989), acute kidney injury (OR: 4.787, 95% CI: 1.674–13.693), norepinephrine dose (OR: 1.706, 95% CI: 1.375–2.117), and abdominopelvic cavity infection (OR: 0.257, 95% CI: 0.076–0.866) were significantly associated with mortality within 28 days after admission in patients with sepsis-related myocardial injury.ConclusionsPatients with sepsis-related myocardial injury have a high mortality rate. A high oxygenation index, occurrence of acute kidney injury, high norepinephrine dose, and occurrence of abdominopelvic cavity infection are independent risk factors for 28-day mortality in patients with sepsis-related myocardial injury.     

Regulation of vascular tone,molecular mechanisms

The goal of this survey was to review briefly the molecular mechanisms that regulate vascular smooth muscle function. Components of the machinery involved in the contraction and relaxation of vascular smooth muscle include the following.Contractile proteins. The force generated by vascular smooth muscle is the result of thin (actin) and thick (myosin) filaments being pulled by one another so that the cell tends to shorten. The processes by which this intereaction is regulated are a matter of some debate. However, most observations indicate that the process that initiates contraction is a calcium-dependent phosphorylation of the myosin light chain.Cellular sites for the regulation of myoplasmic calcium concentration. The final event that initiates the contractile process is an increase in the intracellular concentration of ionized calcium. Cellular sites that may contribute to the raising and lowering of ionized calcium include the following: (A) cell membrane, (B) sarcoplasmic reticulum, and (C) mitochondria.Membrane electrical events. The electrical state of the cell membrane influences contractile responses of vascular smooth muscle. Over the physiologic range, an elevation in the membrane potential has a reciprocal influence on muscle excitability. The membrane potential is the sum of the diffusion potentials and the electrogenic pump.Excitation-contraction coupling. The excitatory events of the cell membrane (changes in membrane potential and the generation of action potentials) are coupled to the interaction of the contractile proteins by an increase in myoplasmic ionized calcium.Cyclic nucleotides and calcium. Cyclic AMP and cyclic GMP may link contraction and relaxation to the release and uptake of activator calcium by subcellular organelles. These nucleotides also influence the level of phosphorylation of the myosin light chain.Energy metabolism and hypoxia. The chemical energy source for cellular processes in vascular smooth muscle is ATP. Vascular tone, or maintenance of a contractile force, in this muscle is a relatively efficient process that may reflect a special noncycling link between myosin and actin. Current evidence suggests that hypoxic conditions influence vascular tone by altering the activity of the electrogenic sodium pump.This listing of statements is by no means the final word in molecular mechanisms that govern vascular tone. Indeed, vascular smooth muscle remains to be a constant source of surprises for the interested investigator.     

锌指蛋白ZBTB20生物学功能的研究进展

锌指蛋白ZBTB20是ZBTB锌指蛋白亚家族的新成员,与已知的BCL6和PLZF同源.通过基因打靶小鼠和疾病人群研究,学者们发现ZBTB20在肝脏、胰岛、神经系统和免疫系统等多个器官与系统中具有重要生理学功能,是个体发育、学习记忆、痛觉感受、糖脂代谢等正常生理过程所必需的调节分子.ZBTB20表达或功能异常可导致个体发育障碍,与智障、肿瘤和代谢性疾病等多种重大疾病的病理生理过程密切相关.作为甲胎蛋白基因的主要转录抑制因子,ZBTB20在出生后肝脏甲胎蛋白基因的表达失活中发挥了关键性作用,且与肝癌预后密切相关.人群中ZBTB20基因的缺失与多种肿瘤有关,其点突变可导致Primrose综合征.本文就ZBTB20的生物学功能研究进展作一综述.     

Hypotheses actuelles concernant le role physiologique du glucagon

Resume Parmi les nombreuses actions du glucagon, celles qui sont supposées avoir une signification physiologique sont discutées. Il en est ainsi des effets du glucagon sur le foie, sur le tissu adipeux et sur l'insulino-sécrétion. L'A. discute ensuite le rôle physiologique du glucagon: 1) dans la répartition des substrats énergétiques lors du jeûne ou de l'hypoglycémie; 2) en période post-prandiale. Il en arrive à la conclusion que la conception uniciste du glucagon doit être réformée et qu'il convient de distinguer d'une part le glucagon d'origine pancréatique et d'autre part le ou les glucagons d'origine digestive.

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Summary Among the numerous actions of glucagon those of probable physiological significance are here discussed. These are the effects of glucagon on the liver, adipose tissue and insulin secretion. The A. discusses afterwards the physiological role of glucagon: 1) in the distribution of energy substrates in a fasting or hypoglycaemic state; 2) during the postprandial period. He reaches the conclusion that the unitarian concept of glucagon must be changed and that we have to distinguish on one hand glucagon of pancreatic origin and glucagon or glucagons of intestinal origin on the other hand.

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Zusammenfassung Von den durch Glukagon bewirkten Effekten werden nur die erörtert, die vermutlich von physiologischer Bedeutung sind. Dasselbe gilt für die durch Glukagon auf Leber, Fettgewebe und Insulin-Sekretion erbrachten Wirkungen. Der Verfasser bespricht danach die physiologische Rolle von Glukagon: 1) bei der Verteilung der Energie-Substrate im Falle von Nüchternheit und Hypoglykämie; 2) nach dem Essen. Der A. schließt daraus, daß die einheitliche Auffassung über Glukagon einer Erneuerung bedarf und deshalb die Unterscheidung der Glukagon-Produktion einerseits durch die Bauchspeicheldrüse und andererseits durch den Verdauungskanal angeraten ist.

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Resumen Entre las numerosas acciones del glucagón, se discuten aquellas que — según se cree — tengan un significado patológico. De tal manera, se obtienen efectos del glucagón sobre el hígado, el tejido adiposo y la secreción de insulina. El A. discute luego el papel fisiológico del glucagón: 1) en la repartición de los substratos energéticos en ayunas y en hipoglucemia; 2) en períodopost-prandium. Se llega a la conclusión que el concepto unitario del glucagón debe ser modificado, y que cabe distinguir por una parte el glucagón de origen pancreática, y por la otra el (o los) glucagón de origen digestiva.

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Riassunto Tra le numerose azioni del glucagone vengono discusse quelle che si suppone abbiano un significato fisiologico. Si hanno così degli effetti del glucagone sul fegato, sul tessuto adiposo e sulla secrezione insulinica. L'A. discute poi il ruolo fisiologico del glucagone: 1) nella ripartizione dei substrati energetici in caso di digiuno o di ipoglicemia; 2) nel periodo post-prandiale. Egli giunge alla conclusione che il concetto unitario del glucagone deve essere modificato e che occorre distinguere da una parte il glucagone di origine pancreatica e dall'altra il o i glucagoni di origine digestiva.