scholarly journals Venomotion modulates lymphatic pumping in the bat wing

2009 ◽  
Vol 296 (6) ◽  
pp. H2015-H2021 ◽  
Author(s):  
Ranjeet M. Dongaonkar ◽  
Randolph H. Stewart ◽  
Glen A. Laine ◽  
Michael J. Davis ◽  
David C. Zawieja ◽  
...  
Keyword(s):  
Time Delays ◽  
Lymphatic Vessels ◽  
Separate Experiment ◽  
Surgical Trauma ◽  
Cross Sectional ◽  
Lymphatic Microvessels ◽  
Close Proximity ◽  
Pallid Bats ◽  
Bat Wing ◽  
Lymphatic Pumping

In skin, it is believed that lymph must be pumped by intrinsic contraction of lymphatic muscle, since investigators have not considered that cyclical dilation of venules could compress adjacent lymphatic microvessels. Because lymphatic vessels are sensitive to stretch, we hypothesized that venomotion not only can cause extrinsic pumping of lymph in nearby lymphatic vessels, but also can stimulate intrinsic contractions. Bat wing venules have pronounced venomotion and are in close proximity to lymphatic microvessels, and can be studied noninvasively without the confounding effects of anesthesia, surgical trauma, or contrast agents. Therefore, the interaction between venules and their paired lymphatic vessels in unanesthetized Pallid bats ( n = 8) was evaluated by recording the diameters of both vessels. Four sets of observations suggested that lymphatic and venous contractions were partially coupled. First, venous dilation and contraction produced a significant change in lymphatic microvascular cross-sectional area. Second, lymphatic microvascular contractions were immediately preceded by a change in venular diameter. Third, venular and lymphatic vessel contraction frequencies were positively correlated ( r = 0.75). Fourth, time delays between peak venular systole and onset of lymphatic microvascular contraction were negatively correlated with venomotion magnitude ( r = −0.55) and velocity ( r = −0.64). In a separate experiment, inhibiting venomotion resulted in a 54.3 ± 20.0% ( n = 8) decrease in lymphatic contraction frequency. Furthermore, 85.7% ( n = 56) of lymphatic vessels switch sides and lie adjacent to arterioles when venules were too small to exhibit venomotion. These results are consistent with both extrinsic pumping of lymph and stretch-induced lymphatic contraction and imply that intrinsic and extrinsic pumping can be coupled.

Spontaneous contractions of isolated bat wing venules are inhibited by luminal flow

1993 ◽  
Vol 264 (4) ◽  
pp. H1174-H1186 ◽  
Author(s):  
M. J. Davis
Keyword(s):  
Contractile Function ◽  
Exact Nature ◽  
Cross Sectional ◽  
Contraction Frequency ◽  
In Series ◽  
Luminal Flow ◽  
Pallid Bats ◽  
Spontaneous Contractions ◽  
Bat Wing

The hypothesis that spontaneous contractions of bat wing venules could be modulated by luminal flow was tested. Single venules (114 +/- 5 microns diam) from the wings of anesthetized pallid bats were dissected, cannulated, and pressurized in vitro. A dual reservoir system was used to independently control luminal pressure and flow. In the absence of flow, and with pressure set to 10 cmH2O, all venules contracted spontaneously at rates between 20 and 40 cycles/min. Pressure elevation over the range of 3-10 cmH2O caused a rapid increase in contraction frequency and decrease in amplitude; pressure reduction caused a rapid decrease in contraction frequency and increase in amplitude. In contrast, initiation of flow resulted in a delayed and gradual reduction of contraction amplitude and/or frequency (sometimes to zero). The net effect of flow was to increase mean diameter and decrease the product of frequency x cross-sectional area. Flow-induced inhibition of venular contraction was eliminated by endothelial denudation but persisted in the presence of NG-monomethyl-L-arginine (10(-4) M) or indomethacin (10(-5) M) in concentrations that blocked the effects of exogenously applied ATP or arachidonic acid, respectively. The flow-induced venular response also persisted in the presence of superoxide dismutase (55 U/ml). Denuded venules responded to flow when placed downstream (i.e., perfused in series) from venules with intact endothelium. These results indicate that luminal flow can modulate the contractile function of bat wing venules via release of a transferable substance from the endothelium. The exact nature of the substance is not yet known but it does not appear to be classical endothelium-derived relaxing factor, a prostaglandin, or an oxygen radical.

Hearing Outcome of Stapes Surgery in NIENT, Bangladesh

2020 ◽  
Vol 26 (1) ◽  
pp. 31-36
Author(s):  
Md Zakaria Sarkar ◽  
AHM Ferdows Nur ◽  
Utpal Kumar Dutta ◽  
Muhammad Rafiqul Islam ◽  
Debabrota Roy ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cross Sectional Study ◽  
Surgical Trauma ◽  
Group 14 ◽  
Progressive Hearing Loss ◽  
Cross Sectional ◽  
Hearing Gain ◽  
Hearing Outcome

Objective: The aim of this study was to evaluate hearing outcome after stapedotomy in patients with Otosclerosis. Methods: This cross sectional study was carried out from July 2017 to January 2019 in National Institute of ENT, Unit V. About 22 patients with Otosclerosis were included in this study. Diagnosis of Otosclerosis was based on the history, medical status with Otoscopy, Tuning fork tests and Audiometric tests. We compiled data on the pre and post operative air-bone gap (ABG) at 0.5, 1, 2 KHZ. The ABG was Calculated using AC and BC thresholds on the same audiogram. Post operative hearing gain was then Calculated from the ABG before the operation minus the ABG of the last follow up examination Results: In this study most of the cases were age group 14-30 years (72.7%), female (54.5%). Most common symptoms was progressive hearing loss, tinnitus (77.8%).The average preoperative hearing loss in this study was (AC) was 48.31±7.68. The average post opt. hearing (AC) at follow up was 28.95±10.30 with an average hearing gain of 15.40±8.53 dB which was significant. The average pre-operative ABG was 28.99 dB ± 8.10. The average post opt. ABG was analyzed at 1 follow up showed ABG 13.18±8.09 dB which was found to be significant. Conclusion: Stapedotomy is an effective surgical procedure for the treatment of otosclerosis which leads to improvement in patient’s quality of life. A favorable hearing outcome can be obtained by the combination of experienced hands with minimal surgical trauma and appropriate surgical technique. Bangladesh J Otorhinolaryngol; April 2020; 26(1): 31-36

A Cross Sectional Analysis of Tourism Development and Social Development

2021 ◽  
Vol 12 (2) ◽  
pp. 487
Author(s):  
Tauseef AMAN ◽  
Mussawar SHAH ◽  
Humera JAMAL ◽  
Younas KHAN ◽  
Muhammad ARIF ◽  
...  
Keyword(s):  
Social Development ◽  
Local Community ◽  
Tourism Development ◽  
Chi Square ◽  
Cross Sectional ◽  
Close Proximity ◽  
Chi Square Test ◽  
The Government ◽  
Sectional Analysis ◽  
The Relationship

The major objective of this study was to measure the association between various interventions and Chitral Gole National Park (CGNP) role in preservation of bio-diversity and socio-economic uplift. A sample size of 346 respondents was randomly selected from total population of 3326 from the 4 selected villages on the basis of close proximity. A conceptual framework including dependent variable social development and independent variable tourism development were taken. The data were analyzed through frequency and percentage distribution. Moreover, Chi-square test was applied to know the relationship between dependent and independent variables at bi-variate level. In bi-variate analysis a highly significant (P=0.000) relation was found between CGNP is main source of promoting tourism in Chitral,tourists do any impacts upon local community in terms of increased business activities, local culture is safeguarded despite influx of tourists in the area, tourism produced employment opportunities, and social development. Qualitative data supported the empirical findings, however tourism brings economic opportunities at micro and macro level, but unfortunately CGNP is not as satisfactory regarding generating income since its establishment. The government should ensure to make such polices pertaining to the entrance fee, provides accommodation services on payment to the tourists and to reserve the entrance fee or any other form of taxes to ensure CGNP to spend on self-sustaining basis by ensuring refinement in the procedures as well.

scholarly journals Clinical and Epidemiological Profile of Herpes Zoster; A Cross-Sectional Study from Tertiary Hospital

Med Phoenix ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 60-65
Author(s):  
Vikash Paudel ◽  
Buddhi Raj Pandey ◽  
Richa Tripathee ◽  
Rishabh Dev Tripathee ◽  
Shreema Sitaula ◽  
...  
Keyword(s):  
Herpes Zoster ◽  
Tertiary Hospital ◽  
Cross Sectional Study ◽  
Traditional Healers ◽  
Surgical Trauma ◽  
Cross Sectional ◽  
Varicella Zoster ◽  
Duration Of Disease ◽  
Epidemiological Profile ◽  
Time Of Presentation

Background: Herpes zoster is dermatomal neuropathic disease caused by reactivation of varicella zoster virus, characterized by vesicobullous eruptions. Although, being a common cause of morbidity, there are few clinicepidemiological studies and the studies regarding the knowledge and practice among the patients are nominal.Methods: This was descriptive observational study which included 100 consecutive patients with herpes zoster who presented to Department of Dermatology and Venereology in a Teaching Hospital, Kathmandu during the period from July 2014 to June 2015.Results: The annual incidence was 0.55%. Seventy two percent were males and 28 percent were females with the M: F=2.5:1. The average age of patients and mean duration of disease was 40.4 years and 5.5 days respectively. Ninety five percent were managed at OPD and 5 % of them needed hospitalization. Most common dermatome involved was thoracic (50%) followed by cervical (20%). Twelve percent had one or more provocative features including diabetes, steroid use, chemotherapy, surgical trauma etc. Twenty patients had definite history chicken pox. Twenty-five percent had local complication at the time of presentation. Fifty two percent had themselves identified the lesion as herpes zoster. However, only 10 had some knowledge about it. Twelve percent had visited traditional healers prior to hospital arrival.Conclusions: The results show varied clinicoepidemiologic patterns of herpes zoster. Major patient have less knowledge about it. A larger study would be necessary for better clinical, epidemiological and social behavioral data. Because of ignorance and tradition, awareness program should be conducted to reduce potential complications. Med Phoenix. Vol. 3, Issue. 1, 2018, Page: 60-65                                             

Modulation of bat wing venule contraction by transmural pressure changes

1992 ◽  
Vol 262 (3) ◽  
pp. H625-H634 ◽  
Author(s):  
M. J. Davis ◽  
X. Shi ◽  
P. J. Sikes
Keyword(s):  
Venous Pressure ◽  
Transmural Pressure ◽  
The Body ◽  
Intraluminal Pressure ◽  
Positive Pressure ◽  
Cross Sectional ◽  
Series Of Experiments ◽  
Pressure Changes ◽  
Bat Wing

We tested the hypothesis that the frequency and amplitude of spontaneous venular contractions in the bat wing could be modulated by changes in transmural pressure. In one series of experiments, venous pressure in the wing was elevated by pressurizing a box containing the body of the animal while the wing was exposed to atmospheric pressure. During this time, venular diameters were continuously recorded using intravital microscopic techniques while venular pressures were measured through servo-null micropipettes. In another series of experiments, single venular segments were dissected from the wing, cannulated, and pressurized in vitro. The results from both experimental protocols were qualitatively similar; alterations in venous pressure over a narrow range (+/- 5 cmH2O from control) produced substantial changes in contraction frequency and amplitude. The product of frequency and cross-sectional area was maximal over the venous pressure range between 10 and 15 cmH2O. Venules demonstrated a rate-sensitive component in their reaction to rapid pressure changes, because contraction bursts occurred immediately after positive pressure steps and quiescent periods often occurred after negative pressure steps. We conclude that venular vasomotion in the bat wing is modulated by intraluminal pressure and involves a bidirectional, rate-sensitive mechanism. In addition, comparisons with arteriolar vasomotion studies suggest that venules are more sensitive to luminal pressure changes than arterioles.

scholarly journals Mesquite bugs and other insects in the diet of pallid bats in southeastern Arizona

2018 ◽  
Author(s):  
Nicholas J Czaplewski ◽  
Katrina L Menard ◽  
William D Peachey
Keyword(s):  
United States ◽  
Behavioral Plasticity ◽  
Late Summer ◽  
Southwestern United States ◽  
Dietary Flexibility ◽  
Soil Piping ◽  
The Face ◽  
Pallid Bats ◽  
Small Vertebrate ◽  
Bat Wing

The pallid bat (Antrozous pallidus) is a species of arid and semiarid western North America, inhabiting ecoregions ranging from desert to oak and pine forest. Considered primarily insectivorous predators on large arthropods but taking occasional small vertebrate prey, pallid bats were recently shown to be at least seasonally omnivorous; they demonstrate unusual dietary flexibility and opportunism in certain parts of their geographic range and at different times of year. In a few areas they take nectar from cactus flowers and eat cactus fruit pulp and seeds. Until recently mesquite bugs were primarily tropical-subtropical inhabitants of Mexico and Central America but have since occupied the southwestern United States where mesquite trees occur. Pallid bats regularly use night roosts as temporary shelters in which to process and consume large arthropods caught near their foraging areas. Using a noninvasive method, we investigated the bats’ diet by collecting food parts discarded by the bats beneath three night roosts in soil-piping cavities at the Cienega Creek Natural Preserve, Arizona. We also made phenological and behavioral observations of the mesquite bugs, Thasus neocalifornicus, and their interactions with the mesquite trees. The bats discarded inedible parts of at least 36 species in 8 orders of mainly large-bodied and nocturnal insects below the night-roosts. In addition, one partial bat wing represents predation upon a phyllostomid bat, Choeronycteris mexicana. About 17 of the insect taxa are newly reported as prey for pallid bats, as is the bat C. mexicana. The large majority of culled insect parts (88.8%) were from adult mesquite bugs. As nymphs, mesquite bugs are aposematically colored and secrete noxious pheromones; nymphs did not appear in the bat-culled insect parts. Adult mesquite bugs are darkly colored and secrete different noxious pheromones than the nymphs. During daytime hours in the summer adult bugs are abundant, flying around the canopy and alighting on the edges of the trees. In late summer and early fall they breed and lay eggs that overwinter on the mesquite branches to hatch in January. Soon after breeding, the adult bugs die. When summer heat diminishes and nighttime low temperatures drop below 21°C, the adult bugs become immobile on the periphery of the trees where they probably make easy prey for foliage-gleaning pallid bats. The historically subtropical-tropical mesquite bugs may have moved into the southwestern United States with the spread of cattle and mesquites. In this area of Arizona, pallid bats provide an important natural control on the local mesquite bug population. The high diversity of other insect remains and the remains of another species of bat provide additional supportive evidence of a diet for pallid bats that reflects their plasticity across a variety of habitats. This behavioral plasticity probably enhances the bats’ survival across their range in the face of climate change.

scholarly journals Carriage of ESBL-producing Enterobacterales in wastewater treatment plant workers and surrounding residents - The AWARE Study

2021 ◽  
Author(s):  
Daloha Rodriguez-Molina ◽  
Fanny Berglund ◽  
Hetty Blaak ◽  
Marcela Popa ◽  
Carl-Fredrik Flach ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Wastewater Treatment Plant ◽  
Reference Group ◽  
Treatment Plant ◽  
Cross Sectional Study ◽  
Sensitivity Analyses ◽  
Cross Sectional ◽  
Increased Risk ◽  
Close Proximity

Purpose. To investigate whether wastewater treatment plant (WWTP) workers and residents living in close proximity to a WWTP have elevated carriage rates of ESBL-producing Enterobacterales, as compared to the general population. Methods. From 2018 to 2020, we carried out a cross-sectional study in Germany, the Netherlands, and Romania among WWTP workers (N=344), nearby residents (living ≤ 300 meters away from WWTPs; N=431) and distant residents (living ≥ 1000 meters away = reference group; N=1165). We collected information on potential confounders via questionnaire. Culture of participants' stool samples was performed with ChromID®-ESBL agar plates and species identification with MALDI-TOF-MS. We used logistic regression to estimate the odds ratio (OR) for carrying ESBL-producing E. coli (ESBL- EC). Sensitivity analyses included stratification by country and interaction models using country as secondary exposure. Results. Prevalence of ESBL-EC was 11% (workers), 29% (nearby residents), and 7% (distant residents), and higher in Romania (28%) than in Germany (7%) and the Netherlands (6%). Models stratified by country showed that within the Romanian population, WWTP workers are about twice as likely (aOR = 2.34, 95% CI: 1.22-4.5) and nearby residents about three times as likely (aOR = 3.17, 95% CI: 1.8-5.59) to be ESBL-EC carriers, when compared with distant residents. Conclusions. In stratified analyses by country, we found an increased risk for carriage of ESBL-EC in Romanian workers and nearby residents. This effect was higher for nearby residents than for workers, which suggests that, for nearby residents, factors other than the local WWTP could contribute to the increased carriage.

scholarly journals Mesquite bugs, other insects, and a bat in the diet of pallid bats in southeastern Arizona

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6065
Author(s):  
Nicholas J. Czaplewski ◽  
Katrina L. Menard ◽  
William D. Peachey
Keyword(s):  
Late Summer ◽  
Geographic Range ◽  
Western North America ◽  
Noninvasive Method ◽  
Antrozous Pallidus ◽  
Soil Piping ◽  
Pallid Bats ◽  
Small Vertebrate ◽  
Bat Wing ◽  
Pallid Bat

The pallid bat (Antrozous pallidus) is a species of western North America, inhabiting ecoregions ranging from desert to oak and pine forest. They are primarily insectivorous predators on large arthropods that occasionally take small vertebrate prey, and are at least seasonally omnivorous in certain parts of their geographic range where they take nectar from cactus flowers and eat cactus fruit pulp and seeds. Until recently, mesquite bugs were primarily tropical-subtropical inhabitants of Mexico and Central America but have since occupied the southwestern United States where mesquite trees occur. Using a noninvasive method, we investigated the bats’ diet at the Cienega Creek Natural Preserve, Arizona, by collecting food parts discarded beneath three night roosts in soil-piping cavities in a mesquite bosque. We also made phenological and behavioral observations of mesquite bugs, Thasus neocalifornicus, and their interactions with the mesquite trees. We determined that the bats discarded inedible parts of 36 species in 8 orders of mainly large-bodied and nocturnal insects below the night-roosts. In addition, one partial bat wing represents probable predation upon a phyllostomid bat, Choeronycteris mexicana. About 17 of the insect taxa are newly reported as prey for pallid bats, as is the bat C. mexicana. The majority of culled insect parts (88%) were from adult mesquite bugs. Mesquite bug nymphs did not appear in the culled insect parts. After breeding in late summer, when nighttime low temperatures dropped below 21 °C, the adult bugs became immobile on the periphery of trees where they probably make easy prey for opportunistic foliage-gleaning pallid bats. Proximity of night-roosts to mesquite bug habitat probably also enhances the bats’ exploitation of these insects in this location.

Modulation of lymphatic pumping by lymph-borne factors after endotoxin administration in sheep

1990 ◽  
Vol 68 (1) ◽  
pp. 199-208 ◽  
Author(s):  
R. M. Elias ◽  
M. G. Johnston
Keyword(s):  
Potent Inhibitor ◽  
Lymphatic Vessels ◽  
Transmural Pressure ◽  
Test Animal ◽  
Indwelling Catheter ◽  
Endotoxin Administration ◽  
Lymphatic Pumping ◽  
Pumping Activity

The purpose of this study was to test the hypothesis that endotoxin administration to sheep results in host-derived lymph-borne factors that modulate lymphatic pumping activity. To achieve this, two sheep were used for each experiment. In the test animal, a segment of intestinal lymphatic was isolated from all lymph input and provided with lymph from a reservoir. Pumping activity was initiated with a fixed transmural pressure applied to the test vessel, and the only input to this duct was provided by lymph from an indwelling catheter in a second donor sheep. The intravenous administration of endotoxin to the donor animals (33 micrograms/kg) generally resulted in increased pumping in the test vessels over the 1st h, but this was followed by reductions in pumping until flow stopped in all preparations. In control experiments (no endotoxin administered) pumping was unaffected. Further investigation revealed that these activities were relatively unstable and, in the case of the inhibitory material, appeared to act by decreasing the sensitivity of the vessel to changes in transmural pressure, because flow could be reestablished in the test vessels by elevating transmural pressures above the level originally chosen for the experiment. Endotoxin itself had no direct effect on sheep lymphatics in vivo or on bovine lymphatic vessels in vitro. However, the appearance of erythrocyte hemolysate (erythrolysate) in lymph was regularly observed after endotoxin infusion, and we demonstrated that erythrolysate (diluted to contain 10(-5) M hemoglobin) was a potent inhibitor of lymphatic pumping in vivo and in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

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