Influence of tidal volume on histamine-induced bronchoconstriction in guinea pigs

1990 ◽  
Vol 68 (4) ◽  
pp. 1634-1639 ◽  
Author(s):  
M. Benichou ◽  
A. M. Lorino ◽  
H. Lorino ◽  
I. Macquin-Mavier ◽  
N. Istin ◽  
...  

The effects of tidal volume amplitude on bronchopulmonary reactivity were investigated in three groups of 14 anesthetized paralyzed mechanically ventilated guinea pigs. Animals of group 1 served as control; in animals of group 2, both the sympathetic and parasympathetic nervous systems were blocked; in animals of group 3, only the parasympathetic system was blocked. In each group, the animals were randomly divided into two subgroups characterized by their ventilatory pattern: rate of 60/min with a 6-ml/kg tidal volume or rate of 40/min with a 9-ml/kg tidal volume. Bronchopulmonary reactivity to infused histamine was assessed by the respiratory compliance and conductance values measured during bronchoconstriction and expressed as a percentage of the corresponding basal values. In group 1 the animals ventilated with a 9-ml/kg tidal volume were found significantly less reactive than those ventilated with a 6-ml/kg tidal volume. This difference was abolished in groups 2 and 3. These results demonstrate that the effects of increased tidal volume on bronchopulmonary reactivity are vagally mediated and suggest that the decrease observed in histamine-induced bronchoconstriction is mainly due to reflex effects evoked by stretch receptor stimulation.

1969 ◽  
Vol 47 (12) ◽  
pp. 993-997 ◽  
Author(s):  
Omer Pelletier

To elucidate the mode of action of D-isoascorbic acid (IAA) in exerting vitamin C activity for guinea pigs, it was necessary to determine the turnover rate of this ascorbic acid in their organs as well as its effect on the turnover of L-ascorbic acid (AA). Guinea pigs were saturated with either IAA or AA, and the organ contents of the isomers were determined at different intervals of depletion. In a second experiment, guinea pigs previously saturated with AA were injected intraperitoneally with L-ascorbic-1-14C acid. Twenty-four hours after injection, L-ascorbic-1-14C acid was measured in the organs of some of the animals; three groups were formed with the other animals: group 1 was fed with a diet deficient in vitamin C, group 2 with the diet plus 0.1% AA, and group 3 with the diet plus 2% IAA. The L-ascorbic-1-14C acid content of the organs was determined on different days. It was found that the rate of IAA turnover was much more rapid than that of AA in all organs. Furthermore, IAA increased rather than decreased the turnover of AA.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Stephanie Klinzing ◽  
Federica Stretti ◽  
Alberto Pagnamenta ◽  
Markus Bèchir ◽  
Giovanna Brandi

Abstract Background The investigation of CO2 reactivity (CO2-CVR) is used in the setting of, e.g., traumatic brain injury (TBI). Transcranial color-coded duplex sonography (TCCD) is a promising bedside tool for monitoring cerebral hemodynamics. This study used TCCD to investigate CO2-CVR in volunteers, in sedated and mechanically ventilated patients without TBI and in sedated and mechanically ventilated patients in the acute phase after TBI. Methods This interventional investigation was performed between March 2013 and February 2016 at the surgical ICU of the University Hospital of Zurich. Ten volunteers (group 1), ten sedated and mechanically ventilated patients (group 2), and ten patients in the acute phase (12–36 h) after severe TBI (group 3) were included. CO2-CVR to moderate hyperventilation (∆ CO2 -5.5 mmHg) was assessed by TCCD. Results CO2-CVR was 2.14 (1.20–2.70) %/mmHg in group 1, 2.03 (0.15–3.98) %/mmHg in group 2, and 3.32 (1.18–4.48)%/mmHg in group 3, without significant differences among groups. Conclusion Our data did not yield evidence for altered CO2-CVR in the early phase after TBI examined by TCCD. Trial registration Part of this trial was performed as preparation for the interventional trial in TBI patients (clinicaltrials.gov NCT03822026, 30.01.2019, retrospectively registered).


1962 ◽  
Vol 203 (1) ◽  
pp. 151-154 ◽  
Author(s):  
R. H. Rech ◽  
L. E. McCarthy ◽  
H. L. Borison

Two types of experiments were performed on unanesthetized guinea pigs: a) acute parabiotic union with common peritoneal cavity; and b) continuous cross circulation. Three combinations of animal pairs were employed in each type of experiment, grouped as follows: group 1, both partners were not vagotomized; group 2, both partners were vagotomized; group 3, one partner was vagotomized and its mate was not vagotomized. Lung-to-body weight ratio served as the index of pulmonary edema. In the parabiosis series, the vagotomized partner of group 3 was protected from edema by being joined with a nonvagotomized animal. In the cross-circulation series, the nonvagotomized partner of group 3 developed pulmonary edema as a result of being cross-perfused with a vagotomized animal. In both series, survival time of vagotomized animals was prolonged by their being juxtaposed to nonvagotomized animals. Interaction between vagotomized and nonvagotomized partners in parabiosis as well as in cross-circulation experiments is best explained by exchange of an edemagenic substance.


2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Rahmi Sofiana ◽  
Anak A.G.P. Wiraguna ◽  
Wimpie Pangkahila

Abstract: Ultraviolet B (UVB) ray may cause skin hyperpigmentation due to increased melanin level. Noni seeds (Morinda citrifolia) extract was a strong candidate as an antioxidant and whitening agent. This study was aimed to prove the effect of noni seeds extract cream in prevention the increase of melanin in UVB-exposed guinea pig (Cavia porcellus). This was a true experimental study using posttest only control group design. Subjects were 30 guinea pigs divided into 3 groups, each of 10 guinea pigs. Group 1, the control group, was treated with UVB exposure and basic cream; group 2 was treated with UVB and 4% noni seed cream; and group 3 was treated with UVB and 4% hydroquinone cream. A total of 390 mJ/cm2 ultraviolet B dosage was given for 2 weeks. Histopathological examination with Masson-Fontana staining was performed to evaluate the melanin areas with black color. The amount of melanin was calculated by the percentage of pixel areas of melanin and was compared with the pixels of all epidermal tissues. The results showed that the highest number of melanin was in group 1 (10.61±5.33%), while in group 2 was 1.4±0.65%, and in group 3 was 0.45±0.23%. There was a significant difference between the control group and group 2 as well as group 3 (P <0.05) whereas no significant difference was found between group 2 and group 3 (P >0.05). Conclusion: The 4% noni seeds extract (Morinda citrifolia) cream could prevent the increase of skin melanin in UVB-exposed guinea pig as effective as 4% hydroquinone cream.Keywords: noni seeds extract cream, melanin, ultraviolet B, guinea pigs Abstrak: Paparan sinar ultraviolet B (UVB) mengakibatkan terjadinya kelainan hiperpigmentasi yang ditandai dengan peningkatan jumlah melanin. Ekstrak biji mengkudu memiliki kombinasi zat aktif yang dapat bekerja sinergis dalam mencegah peningkatan jumlah melanin. Penelitian ini bertujuan untuk membuktikan efek pemberian krim ekstrak biji mengkudu (Morinda citrifolia) dalam mencegah peningkatan jumlah melanin kulit marmut (Cavia porcellus) yang dipapar sinar UVB. Jenis penelitian ialah eksperimental dengan randomized posttest only control group design menggunakan 30 ekor marmut jantan yang dibagi atas 3 kelompok, masing-masing 10 ekor. Kelompok 1 yaitu kelompok kontrol, diberi paparan sinar UVB dan diolesi krim dasar. Kelompok 2 diberi paparan sinar UVB dan krim ekstrak biji mengkudu 4%. Kelompok 3 diberi paparan sinar UVB dan krim hidrokuinon 4%. Dosis total UVB yaitu 390 mJ/cm2 diberikan selama 2 minggu. Pemeriksaan histopatologik jaringan kulit dengan pewarnaan Masson- Fontana. Jumlah melanin dihitung dengan persentase pixel luas area melanin dibandingkan dengan pixel seluruh jaringan epidermis. Hasil penelitian menunjukkan jumlah melanin pada Kelompok 1 sebesar 10,61±5,33%; pada kelompok 2 sebesar 1.4±0.65%, dan pada kelompok 3 sebesar 0,45±0,23%. Terdapat perbedaan bermakna antara kelompok 1 dengan kelompok 2 dan 3 (P <0,05). Perbandingan antara kelompok 2 dan 3 tidak berbeda bermakna dalam mencegah peningkatan jumlah melanin (P >0,05). Simpulan: Krim ekstrak biji mengkudu 4% dapat mencegah peningkatan jumlah melanin kulit marmut yang dipapar sinar UVB, dan memiliki efektifitas yang sama dengan krim hidrokuinon 4%. Kata kunci: krim ekstrak biji mengkudu, melanin, ultraviolet B, marmut


VASA ◽  
2020 ◽  
Vol 49 (4) ◽  
pp. 281-284
Author(s):  
Atıf Yolgosteren ◽  
Gencehan Kumtepe ◽  
Melda Payaslioglu ◽  
Cuneyt Ozakin

Summary. Background: Prosthetic vascular graft infection (PVGI) is a complication with high mortality. Cyanoacrylate (CA) is an adhesive which has been used in a number of surgical procedures. In this in-vivo study, we aimed to evaluate the relationship between PVGI and CA. Materials and methods: Thirty-two rats were equally divided into four groups. Pouch was formed on back of rats until deep fascia. In group 1, vascular graft with polyethyleneterephthalate (PET) was placed into pouch. In group 2, MRSA strain with a density of 1 ml 0.5 MacFarland was injected into pouch. In group 3, 1 cm 2 vascular graft with PET piece was placed into pouch and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. In group 4, 1 cm 2 vascular graft with PET piece impregnated with N-butyl cyanoacrylate-based adhesive was placed and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. All rats were scarified in 96th hour, culture samples were taken where intervention was performed and were evaluated microbiologically. Bacteria reproducing in each group were numerically evaluated based on colony-forming unit (CFU/ml) and compared by taking their average. Results: MRSA reproduction of 0 CFU/ml in group 1, of 1410 CFU/ml in group 2, of 180 200 CFU/ml in group 3 and of 625 300 CFU/ml in group 4 was present. A statistically significant difference was present between group 1 and group 4 (p < 0.01), between group 2 and group 4 (p < 0.01), between group 3 and group 4 (p < 0.05). In terms of reproduction, no statistically significant difference was found in group 1, group 2, group 3 in themselves. Conclusions: We observed that the rate of infection increased in the cyanoacyrylate group where cyanoacrylate was used. We think that surgeon should be more careful in using CA in vascular surgery.


1984 ◽  
Vol 52 (03) ◽  
pp. 253-255 ◽  
Author(s):  
C Isles ◽  
G D O Lowe ◽  
B M Rankin ◽  
C D Forbes ◽  
N Lucie ◽  
...  

SummaryWe have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thrombo- globulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.


2020 ◽  
pp. 64-75
Author(s):  
E. Burleva ◽  
O. Smirnov ◽  
S. Tyurin

The purpose of the study was to conduct a comparative assessment of the course of the postoperative period after phlebectomy and thermal ablation in patients with varicose veins of the lower extremities in the system of the great saphenous vein (GSV) with class C2 of chronic venous insufficiency (CVI) — CEAP class C2. Materials and methods: 455 patients (455 limbs) with CEAP class C2. Group 1 (n = 154) received stripping + minimally invasive phlebectomy; Group 2 — endovenous laser ablation (EVLA) of GSV trunk + sclerotherapy of varicose veins; 3 group (n = 150) — radiofrequency ablation (RFA) of the GSV + sclerotherapy. All patients were united by a single tactical solution — the elimination of pathological vertical reflux in GSV. In each group, patients were with similar hemodynamic profile were selected (Group 1 = 63; Group 2 = 61; Group 3 = 61). The course of the postoperative period (from 2 days to 2 months) was compared for pain (visual analog scale — VAS), clinical symptoms of chronic venous insufficiency, degree of satisfaction (Darvall questionnaire), and duration of disability. Statistical processing was carried out using Excel programs for Windows XP, MedCalc® (version 11.4.2.0., Mariakerke, Belgium). Results: Postoperative pain is more pronounced (during day 1 for Group 1–4.0, Group 2–3.0, Group 3–2.0) and more prolonged (up to 4 days) after open surgeries (p < 0.05). The dynamics of the clinical symptoms of CVI (including varicose syndrome and use of compression therapy) could not be fully evaluated in connection with the ongoing sclerotherapy procedures for patients of Groups 2 and 3. Satisfaction of patients with aesthetic aspects was higher than expected in all groups. Reliable statistical differences proved decrease in days of disability (Group 1–14; Group 2–4; Group 3–3) and earlier return to physical activities and work in patients after thermal ablation in comparison with phlebectomy. Conclusion: The study shows that all three methods for eliminating vertical reflux in the GSV can be proposed for a large category of patients with CEAP of class C3 and C2. Medical and social rehabilitation of patients using endovascular thermal ablation technologies proceeds faster, which is beneficial both for the patients and for society.


To identify the prevalence of early pathology of cardiovascular diseases, a survey of 400 200 girls) in the age group 15 and 17 years old was conducted as a part of routine medical of the level of blood pressure (BP) was carried out, with the calculation of the average level pressure on the basis of three separate measurements estimated by percentile tables for a registration of a standard resting ECG in 12 leads. According to the results of the survey, into 3 groups: with an increase in blood pressure above 95 ‰ (group 1 – 16 people), which recorded in males (p<0,05); Group 2 (67 people) – adolescents with a normal blood pressure level and group 3 of adolescents with a decrease in blood pressure below 5 ‰ changes in the form of rhythm and conduction disturbances were noted in almost every a predominance of sinus tachycardia in the first group. In the third group of adolescents, form of ectopic rhythm and pacemaker migration were significantly more frequently only 78 % of adolescents were referred for consultation and in-depth examination by a pediatric cardiologist.


2019 ◽  
Vol 17 (4) ◽  
pp. 354-364
Author(s):  
Hassan Al-Thani ◽  
Moamena El-Matbouly ◽  
Maryam Al-Sulaiti ◽  
Noora Al-Thani ◽  
Mohammad Asim ◽  
...  

Background: We hypothesized that perioperative HbA1c influenced the pattern and outcomes of Lower Extremity Amputation (LEA). Methods: A retrospective analysis was conducted for all patients who underwent LEA between 2000 and 2013. Patients were categorized into 5 groups according to their perioperative HbA1c values [Group 1 (<6.5%), Group 2 (6.5-7.4%), Group 3 (7.5-8.4%), Group 4 (8.5-9.4%) and Group 5 (≥9.5%)]. We identified 848 patients with LEA; perioperative HbA1c levels were available in 547 cases (Group 1: 18.8%, Group 2: 17.7%, Group 3: 15.0%, Group 4: 13.5% and Group 5: 34.9%). Major amputation was performed in 35%, 32%, 22%, 10.8% and 13.6%, respectively. Results: The overall mortality was 36.5%; of that one quarter occurred during the index hospitalization. Mortality was higher in Group 1 (57.4%) compared with Groups 2-5 (46.9%, 38.3%, 36.1% and 31.2%, respectively, p=0.001). Cox regression analysis showed that poor glycemic control (Group 4 and 5) had lower risk of mortality post-LEA [hazard ratio 0.57 (95% CI 0.35-0.93) and hazard ratio 0.46 (95% CI 0.31-0.69)]; this mortality risk persisted even after adjustment for age and sex but was statistically insignificant. The rate of LEA was greater among poor glycemic control patients; however, the mortality was higher among patients with tight control. Conclusion: The effects of HbA1c on the immediate and long-term LEA outcomes and its therapeutic implications need further investigation.


2018 ◽  
Vol 46 (1) ◽  
Author(s):  
Ricardo Christ ◽  
Aleksandro Schafer Da Silva ◽  
Mateus Eloir Grabriel ◽  
Luan Cleber Henker ◽  
Renan Augusto Cechin ◽  
...  

  Background: Nitrate and nitrite poisoning is associated with pasture intake that has high nitrate levels and leads to acute methemoglobinemia. Pasture may accumulate nitrate under certain conditions, such as excessively fertilized soil or en­vironmental conditions that enhance the N absorption (rain preceded by a period of drought). After ingestion of plants, this substrate reaches the rumen and, in physiological conditions, is reduced to nitrite and afterward to ammonia. The aim of this study was to evaluate changes in cholinesterase activities and oxidative stress caused by subclinical poisoning for nitrate and nitrite in cattle fed with Pennisetum glaucum in three different fertilization schemes. Materials, Methods & Results: In order to perform the experimental poisoning, the pasture was cultivated in three dif­ferent paddocks: with nitrogen topdressing (urea; group 1), organic fertilizer (group 2) or without fertilizer (group 3; control). Nitrate accumulation in forage was evaluated by the diphenylamine test. After food fasting of 12 h, nine bovine were randomly allocated to one of the experimental groups and fed with fresh forage (ad libitum) from respective pad­dock. In different time points from beginning of pasture intake (0, 2, 4, 6 and 9 h) heart rate and respiratory frequency were assessed, as well as mucous membrane color and behavioral changes. Blood samples from jugular vein into vials with and without anticoagulant were collected. From blood samples, serum nitrite levels, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme activity were evaluated, as well as oxidative stress through the following param­eters: levels of nitrate/nitrite (NOx), thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS), beyond the antioxidant system by enzyme activity measurement of catalase (CAT) and superoxide dismutase (SOD). The diphenylamine test was positive to group 1 and 2, so that the pasture presented 3.16 mg/kg, 2.98 mg/kg and 1.67 mg/kg of nitrate for group 1, 2 and 3, respectively. In addition, cows from group 1 demonstrated increased (P < 0.05) nitrite levels in serum, compared to other groups, and greater heart rate after 9 h (P < 0.05). The AChE and BChE activity in group 1 showed significant increase (P < 0.05) at 4 and 6 h (AChE), and 4 and 9 h (BChE) compared to group 3. Also, NOx levels were lower at 6 and 9 h (P < 0.05) and at 9 h (P < 0.05) for animals of group 1 and 2, respectively, when compared to group 3. Furthermore, in the group 1 levels of ROS and TBARS were significantly higher (P < 0.05) after 2 and 4 h, and 6 and 9 h compared to other groups, respectively. The CAT activity increased significantly (P < 0.05) with 2 and 4 h of the experiment, but on the other hand, decreased at 6 and 9 h in group 1. Nevertheless, the animals from group 2 presented only a significant reduction in this enzyme activity at 9 h. Furthermore, SOD activity was reduced in animals of groups 1 (P < 0.05) at 4, 6 and 9 h, compared to other groups. Discussion: It was concluded that the nitrate and nitrite poisoning by pasture intake cultivated and fertilized with urea leads to increased levels of serum nitrite, as well as the cholinesterase activity and causes oxidative stress in cattle. It is conjectured that the cholinesterase activity and oxidative stress may assist in understanding the pathophysiology of changes caused by poisoning.Keywords: plant toxicology, poisoning, methemoglobin, cholinergic system, oxidative stress.


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