Electrophysiology of pig distal colon measured during early post‐natal development.

Cremaschi, D.; James, P S; Meyer, Gerd; Smith, M. W.

doi:10.1113/jphysiol.1981.sp013696

Cited by 8 publications

(4 citation statements)

References 23 publications

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“…Additionally, UV–vis spectrophotometric measurements of 100 μM PYO, 3:1 (v/v) 100 μM PYO:50 μM NO • , 1:1 (v/v) 100 μM PYO:50 μM NO • , and 50 μM NO • were obtained (Figure S6). The pure PYO spectrum shows characteristic peak maxima at wavelengths of 249, 307, 370, and 697 nm, which have been observed in prior studies. , The pure NO • spectrum shows a distinct absorption peak at 220 nm, associated previously with sσ, pπ, σ, and dδ transitions . Accordingly, as the ratio of PYO to NO • increases, the absorbance of the 220 nm band disappears.…”

Section: Resultssupporting

confidence: 72%

Electrochemical Detection of Multianalyte Biomarkers in Wound Healing Efficacy

2020

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The targeted diagnosis and effective treatments of chronic skin wounds remain a healthcare burden, requiring the development of sensors for real-time monitoring of wound healing activity. Herein, we describe an adaptable method for the fabrication of carbon ultramicroelectrode arrays (CUAs) on flexible substrates with the goal to utilize this sensor as a wearable device to monitor chronic wounds. As a proof-of-concept study, we demonstrate the electrochemical detection of three electroactive analytes as biomarkers for wound healing state in simulated wound media on flexible CUAs. Notably, to follow pathogenic responses, we characterize analytical figures of merit for identification and monitoring of bacterial warfare toxin pyocyanin (PYO) secreted by the opportunistic human pathogen Pseudomonas aeruginosa. We also demonstrate the detection of uric acid (UA) and nitric oxide (NO•), which are signaling molecules indicative of wound healing and immune responses, respectively. The electrochemically determined limit of detection (LOD) and linear dynamic range (LDR) for PYO, UA, and NO• fall within the clinically relevant concentrations. Additionally, we demonstrate the successful use of flexible CUAs for quantitative, electrochemical detection of PYO from P. aeruginosa strains and cellular NO• from immune cells in the wound matrix. Moreover, we present an electrochemical examination of the interaction between PYO and NO•, providing insight into pathogen–host responses. Finally, the effects of the antimicrobial agent, silver (Ag+), on P. aeruginosa PYO production rates are investigated on flexible CUAs. Our electrochemical results show that the addition of Ag+ to P. aeruginosa in wound simulant decreases PYO secretion rates.

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Section: Resultssupporting

confidence: 72%

Electrochemical Detection of Multianalyte Biomarkers in Wound Healing Efficacy

2020

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“…The explanation put forward to describe similar findings in the colon of neonatal pigs is that some sodium transport is directly coupled to that of chloride (Bentley & Smith, 1975;Cremaschi et al 1979). An alternative explanation, which agrees with measurements of brush-border chloride conductivity in pig distal colon, is that these colons possess an electrogenic active transport process for chloride (Cremaschi et al 1981). There is no way to distinguish between these two possibilities at the present time.…”

Section: Discussionsupporting

confidence: 60%

Sodium transport by lamb proximal colon measured during early postnatal development

Smith

James

1982

J. Agric. Sci.

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SUMMARYProximal colons taken from lambs up to 3 weeks after birth were shown to transport both sodium and chloride from lumen to blood when incubated in vitro.Sodium transport fell into three phases during postnatal development. The first covered the period from birth to 3 days of age when sodium transport was high and equal to that calculated from measurement of short-circuit current. The second was seen in 5- and 7-day-old lambs where the short-circuit current was low and the net transport of sodium was negligible. The third was seen in 2-3-week-old lambs where sodium transport was high, but the short-circuit current was low.Chloride absorption by colons taken from 1-day-old lambs appeared to be in exchange for an anion, possibly bicarbonate. Chloride absorption by colons taken from 3-week-old lambs appeared to be electrogenie or coupled directly to the transport of sodium.A possible explanation for the failure of electrolyte absorption by colons taken from 5- and 7-day-old lambs is discussed.

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“…On the other hand, the amiloride action in other tissues (e.g. in rabbit and pig colon) is also not as immediate as in frog skin and toad urinary bladder (Schultz, Frizzell & Nellans, 1977; Cremaschi, James, Meyer & Smith, 1981). Moreover, the quite low dose with which maximal effects are evoked in gall-bladder, completely comparable with the doses effective in tight epithelia, seems to indicate a similarity of action, directly pointing to Na+ channels.…”

Section: Amiloride-senstive Na+ Channelmentioning

confidence: 99%

Amiloride‐sensitive sodium channels in rabbit and guinea‐pig gall‐bladder.

Cremaschi¹,

Meyer²

1982

The Journal of Physiology

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1. The effects of low amiloride concentrations (less than 2.5 x 10(-5) M) on the apical membrane (Vm) and transepithelial (Vms) potential differences, transepithelial resistance (Rep) and apical/basolateral membrane resistance ratio (Rm/Rs) have been determined in the gall-bladders of the rabbit and guinea-pig. 2. Vm was hyperpolarized, Vms decreased towards negative values, Rm/Rs increased, but Rep remained unchanged. 3. K+ selectivity of the apical membrane was also checked by increasing luminal K+ concentration from 5.9 to 29.4 mM; the corresponding change in the apical electromotive force was much higher in the rabbit than in the guinea-pig. 4. Pre-incubations with Cl--and HCO3--free salines did not modify K+ selectivity in the rabbit, but nearly doubled it in the guinea-pig. 5. Pre-incubations with control solutions containing 10(-5) M-amiloride in the lumen converted the apical membrane of rabbit gall-bladder into a perfectly K+-perm-selective membrane; the same results were obtained in the guinea-pig only on bathing the tissue with Cl-- and HCO3--free salines together with 10(-5) M-amiloride. 6. It is suggested that in the apical membrane of rabbit gall-bladder K+ and Na+ conductances exist, whereas in guinea-pig gall-bladder both K+, Na+ and anion (Cl- and/or HCO3-) conductances are present; in both species conductive Na+ pathways are inhibited by amiloride. .

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Electrophysiology of pig distal colon measured during early post‐natal development.

Cited by 8 publications

References 23 publications

Electrochemical Detection of Multianalyte Biomarkers in Wound Healing Efficacy

Electrochemical Detection of Multianalyte Biomarkers in Wound Healing Efficacy

Sodium transport by lamb proximal colon measured during early postnatal development

Amiloride‐sensitive sodium channels in rabbit and guinea‐pig gall‐bladder.

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