Human Diaphragm Research Articles

Guanidine and Neuromuscular Transmission

The effect of guanidine on the neuromuscular transmission in human intercostal and mouse diaphragm muscle in vitro during repetitive nerve stimulation was studied. The drug greatly increased the release of acetylcholine (ACh) quanta by nerve impulses at low frequencies of nerve stimulation and at the beginning of tetani at high frequencies of stimulation. The effect was shown to be produced by an increase in fractional release from an unchanged store of ACh quanta available fro immediate release. This seems to explain why guanidine has a poor therapeutic effect in myasthenia gravis but a good effect in the myasthenic syndrome.

The isoporous substructure of the human glomerular slit diaphragm

The substructure of the human glomerular slit diaphragm is examined after perfusion fixation of a human kidney with tannic acid-glutaraldehyde. The present study shows that the substructure of the slit diaphragm in man is very similar to that described in rats and mice, and that the dimensions of the contained pores (50 times 120 A) in the human differ only slightly from those reported for the murine kidney. It is unlikely that rectangular pores of the dimensions of those measured in the human kidney would permit, under physiological conditions, the penetration of significant quantities of serum protein molecules. It is possible, therefore, that the slit diaphragm in the human glomerulus could function as a fine filter for serum proteins, although this remains to be definitely proved.

Effect of posture on the ventilatory response to CO2.

ArticleEffect of posture on the ventilatory response to CO2.J R Rigg, A S Rebuck, and E J CampbellJ R Rigg, A S Rebuck, and E J CampbellPublished Online:01 Oct 1974https://doi.org/10.1152/jappl.1974.37.4.487MoreSectionsPDF (879 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByThe effects of head-up and head-down tilt on central respiratory chemoreflex loop gain tested by hyperoxic rebreathingEffect of body position on ventilatory responses in anaesthetised miceComparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, Vol. 141, No. 2Effects of body position on the ventilatory response following an impulse exercise in humansPhilippe Haouzi, Bruno Chenuel, and Bernard Chalon1 April 2002 | Journal of Applied Physiology, Vol. 92, No. 4Discharge frequencies of single motor units in human diaphragm and parasternal muscles in lying and standingJ. E. Butler, D. K. McKenzie, and S. C. Gandevia1 January 2001 | Journal of Applied Physiology, Vol. 90, No. 1Posture effects on timing of abdominal muscle activity during stimulated ventilationTadashi Abe, Takumi Yamada, Tomoyuki Tomita, and Paul A. Easton1 June 1999 | Journal of Applied Physiology, Vol. 86, No. 6Carbon dioxide recruitment threshold as a predictor of successful weaning in chronic obstructive pulmonary disease patients: A pilot studyRespirology, Vol. 2, No. 2The Physiology of Bed Rest1 January 2011Effect of posture on inspiratory muscle electromyogram response to hypercapniaEuropean Journal of Applied Physiology and Occupational Physiology, Vol. 64, No. 3A new method for studying the ventilatory response in patientsActa Anaesthesiologica Scandinavica, Vol. 34, No. 6Ventilation and Breathing Pattern during Progressive Hypercapnia and Hypoxia after Human Heart-Lung TransplantationAmerican Review of Respiratory Disease, Vol. 140, No. 1Effect of posture on ventilatory response to steady-state hypoxia and hypercapniaRespiration Physiology, Vol. 58, No. 1Ventilatory and Mental Effects of Alfentanil and FentanylActa Anaesthesiologica Scandinavica, Vol. 28, No. 1Physiological variationChemical regulation of ventilation during isoflurane sedation and anaesthesia in humansCanadian Anaesthetists’ Society Journal, Vol. 30, No. 6Variable effects of anaesthetics on the ventilatory response to hypoxaemia in manCanadian Anaesthetists’ Society Journal, Vol. 29, No. 2The effect of posture on the ventilatory response to hypoxiaCanadian Anaesthetists’ Society Journal, Vol. 27, No. 5Ventilation and chemoreflexes during enflurane sedation and anaesthesia in manCanadian Anaesthetists’ Society Journal, Vol. 26, No. 5Hypoxic ventilatory responses during thiopentone sedation and anaesthesia in manCanadian Anaesthetists’ Society Journal, Vol. 25, No. 5Conference SummaryChest, Vol. 73, No. 2Recovery of ventilatory response to carbon dioxide after thiopentone, morphine and fentanyl in manCanadian Anaesthetists’ Society Journal, Vol. 23, No. 4Measurement of Ventilatory Response to CO2 by RebreathingChest, Vol. 70, No. 1Occlusion Pressure As A Technique In Evaluating Respiratory ControlChest, Vol. 70, No. 1 More from this issue > Volume 37Issue 4October 1974Pages 487-90 https://doi.org/10.1152/jappl.1974.37.4.487PubMed4413080History Published online 1 October 1974 Published in print 1 October 1974 Metrics

Investigations on the innervation of the human diaphragm.

AbstractIn 2 dogs, 5 cats and 30 human cadavers the diaphragmatic innervation has been studied macroscopically and microscopically. General findings of previous authors regarding phrenic and intercostal nerve contributions have been confirmed and subdiaphragmatic connections from the coeliac plexus to the diaphragm have been clearly demonstrated. The presence of this viscerosomatic interconnection in half of the human subjects studied, highlights the possible importance of autonomic control of diaphragmatic musculature. The finding of comparable autonomic connections in dogs raises the possibility of pursuing the question experimentally by carrying out nerve degeneration studies. In addition the matter of surgical incisions in the diaphragm has been reconsidered and the suggested placements have been illustrated.

Performance and histochemical composition of guinea pig and human diaphragm.

Performance and histochemical composition of guinea pig and human diaphragm.

Mechanical relaxation behavior of collagen, polyglycine I, and nylon 6 in the range from 77° to 420°K

Abstract The dynamic mechanical relaxation behavior of human diaphragm tendon collagen was investigated in the region from 77° to 420°K using an inverted, free oscillating, torsion pendulum. Three relaxation processes, termed α, β, and γ peaks, which strongly depend on the water content and age of the specimens, were observed. Increasing amounts of absorbed water intensify the relaxation strength of all three loss maxima; whereas the α peak shifts to lower temperatures, the β peak remains constant, and the γ peak shifts to higher temperatures. The height of the α, β, and γ relaxations also diminish considerably with increasing age of the tendon donor. Internal friction spectra of collagen are compared as a function of water and crystallinity with the mechanical relaxation properties of polyglycine I and nylon 6. In general, certain similarities were detected for these results, thereby suggesting that the α, β, and γ internal friction maxima of all three materials may originate from similar types of molecu...

An EMG electrode for the diaphragm.

A new electrode for sensing the electrical activity of the human diaphragm is described. The electrode is a bipolar surface unit employed in an esophageal approach to the fibers of the diaphragm comprising the esophageal hiatus. Procedures for its use in human subject are discussed.

Trichiniasis in Man and Animals in Cincinnati, Ohio

Human diaphragms, swine diaphragms, pork products, and wild animals obtained in Cincinnati, Ohio, were examined for the presence of Trichinella spiralis. Larvae were found by means of standard methods of direct microscopic observation and artificial digestion. Of 332 human diaphragms obtained at necropsy 16 proved positive for the presence of T. spiralis, and five of 700 grainand garbage-fed hogs were infected. No evidence of T. spiralis infection was found in either the pork products or wild animals examined. Many studies on the incidence of Trichinella spiralis in man and swine have been conducted in the United States, but none have been done in the Cincinnati area. Most (1965) reviewed studies on human trichiniasis and reported an apparently significant reduction in incidence, mortality, and density of infection in man since 1944, and stated that the adult infection rate in the U. S. is probably 4% or less. Zimmermann and Brandly (1965) reviewed studies on the incidence of T. spiralis in swine, and noted a decline in incidence during the period of their study. Bachman and Rodriguez-Molina (1933) stated that T. spiralis is among the most euryxenous of nematodes. A great deal of controversy has arisen with respect to the importance of reservoir hosts in the epidemiology of the parasite. Among others, Most (1965), Gould (1943), and Wright (1940) discount the possibility of reservoir hosts as a source of infection for swine. On the other hand, Schwartz (1960) considered the role of reservoir hosts as uncertain, and several workers, including Spindler (1953), Olson and Robinson (1958), and Zimmermann et al. (1959), have demonstrated transmission of T. spiralis through the feces of infected animals to clean animals. In view of this experimental evidence of transmission through fecal contamination, and the availability of infected wild animal carcasses to swine, reservoir hosts remain an important possible factor in the epidemiology of T. spiralis. In an attempt to demonstrate a relationship between infected swine and wild animals, Martin et al. (1968) studied two Illinois swine farms. The swine from one farm were fed garbage, and had a history of T. spiralis infection, while the swine Received for publication 16 October 1968. of the other farm were fed grain. Since only two wild animals from each farm were found infected with T. spiralis, no conclusions were drawn regarding the effects of wild animals on the epidemiology of the parasite. MATERIALS AND METHODS Fresh human diaphragm samples were obtained from four Cincinnati hospitals and the Hamilton County Coroner's Office from October 1966 to August 1967. About one-half a diaphragm was collected from randomly selected cadavers at each hospital and data on age, sex, and race were obtained from hospital records whenever possible. All samples were examined by microscopic observation of pressed muscle, and by artificial digestion in 1% pepsin, 1% HC1 in 0.85% NaCl. The sediment from each digested sample was examined under a dissecting microscope. Swine diaphragm samples were obtained from a Cincinnati meat-packing company from January 1966 to September 1966. The swine used by this concern are a mixture of garbage-fed and grainfed animals, but it was not possible to divide the samples on the basis of feed. Swine diaphragm tissue was examined by artificial digestion only. Pork sausage was obtained from the company that provided the diaphragm samples, and from another Cincinnati meat-packing company. The pork products were examined by artificial digestion. A limited number of local animals were examined for T. spiralis larvae. More than 40 rats were trapped at the Cincinnati Zoo, and some commercially valuable fur-bearing animals were obtained from a Cincinnati furrier. The latter animals were taken from nearby areas, but exact collection data were not available. All animals collected were examined by artificial digestion of the diaphragm, tongue, and leg muscles.

Contribution to the knowledge of the development of the human diaphragm : M. Muntener. Z. K. Chir. 5:350–366, 1968

Contribution to the knowledge of the development of the human diaphragm : M. Muntener. Z. K. Chir. 5:350–366, 1968

Quantification of electrical activity in the human diaphragm.

Quantification of electrical activity in the human diaphragm.

Measurement of the separate volume changes of rib cage and abdomen during breathing.

Measurement of the separate volume changes of rib cage and abdomen during breathing.

Re-evaluation of the effect of estrogen on thyroid activity in the rat and its mechanism.

Estradiol benzoate (EB) was injected sc daily for 14 days into male and female rats. EB, over a wide dose range, produced an increase of thyroid weight and thyroidal radioiodine uptake. The increase in these indices was roughly proportional to the doses of EB used. By similar treatment, thyroidal radioiodine release was increased. In hypophysectomized animals, EB stimulated thyroidal radioiodine uptake slightly, but had no effect on thyroid weight. The EB-induced increase of thyroid weight and thyroidal radioiodine uptake of intact animals decreased progressively with the administration of increasing doses of thyroxine, but, at all levels of thyroxine dosage, thyroid weight and thyroidal radioiodine uptake were greater in EB-treated animals than in the controls. EB caused a statistically significant increase in the uptake of labeled thyroxine from plasma by human red blood cells and rat diaphragm. EB lowered plasma PBI in thyroidectomized, thyroxine-maintained animals. It is concluded that EB augments thy...

Nervous output from the respiratory center during obstructed breathing.

Nervous output from the respiratory center during obstructed breathing.

Incidence of Trichinosis

To the Editor:— In Facets of Trichinosis, an editorial in the April 6 issue ofThe Journal( 184 :56), it is stated that 1 of every 6 Americans harbors Trichinella spiralis . A recent study (summer, 1962) conducted here at the University of Pittsburgh, in which 100 human diaphragm specimens were examined microscopically for T spiralis larvae, indicated that the prevalence of trichinosis may be considerably lower than has been suggested by prevalence studies conducted during the 1940's. In the study mentioned, larvae were detected in five of the 100 specimens. This decreased prevalence of trichinosis is in part attributable to the use of grain or cooked garbage in the feeding of hogs, and also to thorough cooking of pork products by a better-informed public.

Utilization of free fatty acids by diaphragm in vitro.

Human and rat diaphragm and rat gastrocnemius muscle oxidize and esterify palmitate-1-C14. Incorporation of C14 was found to be in proportion to the palmitate present in the medium over a range of concentrations from 0.8 to 2.9 µEq/ml. Fasting increased C14O2 production but had no effect on esterification. Iodoacetate or an atmosphere of nitrogen inhibited esterification of palmitate but increased the amount of free fatty acid in the tissue. Insulin increased esterification, and this was enhanced by the addition of glucose. Glucose and insulin exerted a sparing action on the oxidation of glycerides by a tissue previously charged with palmitate-1-C14. Growth hormone administered in vivo over a period of 1 week or in vitro during incubation had no effect on esterification or metabolism of palmitate-1-C14.

Relationship of age to swelling properties of human diaphragm tendon in acid and alkaline solutions.

Relationship of age to swelling properties of human diaphragm tendon in acid and alkaline solutions.

An Electron Microscopic Study of the Muscle-fibres of the Diaphragm

ABSTRACT Myofibrils of rat diaphragm of various ages, in different states of activity, after denervation, and after acetyl choline contracture, were studied by electron microscopy. A comparative study of other rodent diaphragms and of human diaphragm was also made. Myofibrils from diaphragm are similar to those of other striated muscles. The differentiation into A and I bands is due to differences in the substance present round the actomyosin filaments in those regions. The Z disk is extra-sarcomere; it-appears even before any differentiation of the fibril into A and I bands is recognizable. At the age of about 42 days, the myofibrils in rat diaphragm are completely differentiated and conform to the adult type. The sarcomere length in adult rat diaphragm is between 2 and 3 μ. The adult rat diaphragm contains two types of fibrils which differ, though not sharply, in their extensibility and thickness. The A and I bands react differently to a variety of stimuli. Thus, passive stretching affects the I band almost exclusively, while contraction affects both bands; here, again, the effect depends on the type of contraction; isotonic contraction shortens both A and I, whereas isometric contraction shortens A and lengthens I. In the denervated muscle the A band is shortened. On the whole, the A band seems to play the major role in contraction. The H disk is intra-sarcomere and appears during contraction, especially when the muscle is stimulated in the stretched state. The M and N lines also are intra-sarcomere. Evidence regarding their nature and appearance is discussed.

Movements of Human Diaphragm During Cardiac Cycle in Respiratory Pause

SummaryIn man during respiratory pause there are changes in the position of the diaphragm during the cardiac cycle so that in ventricular systole the total thoracic volume is smaller than in diastole. Calculation of the net thoracic changes involved integration of measurements of both vertical and horizontal components of motion in posterior-anterior and lateral projections. The reduction in thoracic volume amounts to a large and apparently rather constant fraction of the cardiac stroke output.