Establishment of Bacteroides succinogenes and measurement of the main digestive parameters in the rumen of gnotoxenic lambs

1988 ◽  
Vol 34 (8) ◽  
pp. 938-946 ◽  
Author(s):  
G. Fonty ◽  
P. Gouet ◽  
Harinirina Ratefiarivelo ◽  
J. P. Jouany
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Group Iv ◽  
Cellulolytic Bacteria ◽  
Bacterial Strains ◽  
Group Iii ◽  
Volatile Fatty Acid Concentration ◽  
Group I ◽  
Group Ii ◽  
And Function

We attempted to determine the degree of diversification of the microflora that allow the establishment of Bacteroides succinogenes S85 in the rumen of gnotoxenic lambs. Four lambs (group I) received an inoculum orally, composed of 182 noncellulolytic bacterial strains (inoculum 1) previously isolated from the rumen of conventional young lambs. Two lambs (group II) were inoculated with 32 strains (inoculum 2) selected among the 182 strains of inoculum 1. Two lambs (group III) received an inoculum (inoculum 3) composed of 106 noncellulolytic bacterial strains previously isolated from the rumen of meroxenic lambs. Two lambs (group IV) were inoculated with 16 strains (inoculum 4) chosen among the 106 strains of inoculum 3. All lambs were inoculated from birth except two lambs of group I, which were inoculated from 1 month of age. Each lamb then received orally a pure culture of B. succinogenes. This strain became established more easily in the rumen of lambs that had received complex inocula (group I). Its population reached a level close to that generally observed in conventional lambs (107–108 bacteria mL−1). In contrast, B. succinogenes became established in only one lamb of group II, but bacterial numbers varied considerably. In group III, repeated inoculations were necessary to obtain its definitive establishment (107–108 bacteria mL−1 after weaning). In spite of several inoculations, this cellulolytic species failed to establish in the rumen of lambs of group IV, which had received the less complex inoculum. The volatile fatty acid levels were very different from one lamb group to another. The more complex the inoculum administered to the animals, the higher the concentration. In those that received inoculum 1, the volatile fatty acid concentration was similar to that measured in conventional lambs fed the same diet (approximately 80 mmol L−1 after feeding). In lambs inoculated with only 16 strains there were almost no fermentations (30 mmol L−1 of volatile fatty acid). These results demonstrate that the establishment of cellulolytic bacteria, functions of the rumen, and the stability of the ecosystem depend on the complexity and diversity of the microflora. In the light of present knowledge, it is not possible to determine accurately the operative composition of the minimum flora enabling rumen development and function.

scholarly journals Microbiome dysbiosis regulates the level of energy production under anaerobic condition

2021 ◽  
Author(s):  
M. Shaminur Rahman ◽  
M. Nazmul Hoque ◽  
Joynob Akter Puspo ◽  
M. Rafiul Islam ◽  
Niloy Das ◽  
...  
Keyword(s):  
Indicator Species ◽  
Energy Production ◽  
Biogas Production ◽  
Group Iv ◽  
Methanosarcina Barkeri ◽  
Bacterial Strains ◽  
Group Iii ◽  
Group I ◽  
Production Group ◽  
Group Ii

The microbiome of the anaerobic digester (AD) regulates the level of energy production. To assess the microbiome dysbiosis in different stages of anaerobic digestion, we analyzed 16 samples dividing into four groups (Group-I = 2; Group-II = 5; Group-III = 5 and Group-IV = 4) through whole metagenome sequencing (WMS). The physicochemical analysis revealed that highest CH 4 production (74.1%, on Day 35 of digestion) was associated with decreased amount of non-metal (phosphorus and sulfur) and heavy metals (chromium, lead and nickel). The WMS generated 380.04 million reads mapped to ~ 2800 distinct bacterial, archaeal and viral genomes through PathoScope (PS) and MG-RAST (MR) analyses. The PS analysis detected 768, 1421, 1819 and 1774 bacterial strains in Group-I, Group-II, Group-III and Group-IV, respectively which were represented by Firmicutes , Bacteroidetes , Proteobacteria , Actinobacteria , Spirochaetes and Fibrobacteres (> 93.0% of the total abundances). The archaeal fraction of the AD microbiomes was represented by 343 strains, of which 95.90% strains shared across these metagenomes. The indicator species analysis showed that Methanosarcina vacuolate , Dehalococcoides mccartyi , Methanosarcina sp. Kolksee and Methanosarcina barkeri were the highly specific for energy production in Group-III and Group-IV. However, most of the indicator phylotypes displayed reduced abundance in the initial stage of biogas production (Group-I and Group-II) compared to their increased relative abundances in Group-IV (Day 35). The correlation network analysis showed that different strains of Euryarcheota and Firmicutes phyla were associated with highest level (74.1%) of energy production (Group-IV). In addition to taxonomic dysbiosis, top CH 4 producing microbiomes showed increased genomic functional activities related to one carbon and biotin metabolism, oxidative stress, proteolytic pathways, MT1-MMP pericellular network, acetyl-CoA production, motility and chemotaxis. This study reveals distinct changes in composition and diversity of the AD microbiomes including different indicator species, and their genomic features that are highly specific for energy production.

scholarly journals Effect and mechanisms of reproductive tract infection on oxidative stress parameters, sperm DNA fragmentation, and semen quality in infertile males

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kang-Sheng Liu ◽  
Xiao-Dong Mao ◽  
Feng Pan ◽  
Rui Fang An
Keyword(s):  
Reproductive Medicine ◽  
Reproductive Tract ◽  
Group Iv ◽  
Semen Parameters ◽  
Group Iii ◽  
Reproductive Tract Infection ◽  
Group I ◽  
Sperm Dna ◽  
Group Ii ◽  
Elastase Level

AbstractRecent years have seen a rising incidence of male infertility, mostly caused by the decline of sperm quality. The ratio of infertile males to infertile females has escalated from 3:7 in 2013 to current 5:5, which turns male infertility into the research focus of reproductive medicine. This study aimed to clarify the effect of reproductive tract infection by ureaplasma urealyticum (UU) and chlamydia trachomatis (CT) on the DNA integrity and routine semen parameters of infertile males. A retrospective study was performed. A total of 259 infertile males who were treated at the Andrological Laboratory Examination and Reproductive Medicine Center in our hospital were analyzed. qRT-PCR was used to examine the infection status of CT and UU. According to the eligibility criteria, we evaluated the semen parameters and biochemical data of 253 men. Based on the results of PCR, the subjects were divided into four groups: Group I (CT positive, 63 cases), Group II (UU positive, 60 cases), Group III (CT positive and UU positive, 62 cases), and Group IV (no infection, 68 cases). DNA fragmentation index (DFI), sperm count, vitality and morphology, elastase level, seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) were assessed. Compared to Group IV, three groups (Group I, Group II and Group III) showed difference in semen volume, proportion of sperm with normal morphology, sperm motility, progressive motility, and vitality (P < 0.05). Compared to Group IV, Group II and Group III showed difference in DFI (P < 0.05). Compared to Group IV, Group II and Group III showed difference in elastase level (P < 0.05). VCL, VSL, VAP, WOB, ROS, TM, HDS showed differences between groups of abnormal/normal WBC (*P < 0.01).UU infection significantly increased the level of seminal leukocytes only in Group II, but not in the other three groups, indicating that UU is a factor to increase the level of seminal leukocytes. Compared with the normal leukocyte group, there were significant differences in total motility, forward motility and normal sperm ratio between the two groups. The proportion of sperm with abnormal morphology (mostly in the head) showed obvious difference between groups of high and normal seminal leukocytic levels. At the same time, in this study, SCGE and SCD verified that leukocytes could damage sperm DNA by increasing ROS, which ultimately affects male fertility.

Effect of amino acid infusion on renal hemodynamics in humans: a dose-response study

1994 ◽  
Vol 267 (5) ◽  
pp. F703-F708 ◽  
Author(s):  
M. Giordano ◽  
P. Castellino ◽  
E. L. McConnell ◽  
R. A. DeFronzo
Keyword(s):  
Amino Acid ◽  
Dose Response ◽  
Renal Hemodynamics ◽  
Group Iv ◽  
Group V ◽  
Group Iii ◽  
Amino Acid Infusion ◽  
Group I ◽  
Basal Plasma ◽  
Group Ii

We evaluated the dose-response relationship between the plasma amino acid (AA) concentration and renal hemodynamics in eight normal subjects. After an overnight fast, a balanced 10% AA solution was infused for 180 min at five separate infusion rates: 0.5 (group I), 1.0 (group II), 2.0 (group III), 4.0 (group IV), and 6.0 (group V) ml.kg-1.min-1 on separate days. Basal plasma AA concentration was 1.87 +/- 0.1 mmol/l and increased to 2.26 +/- 0.1 (group I), 2.66 +/- 0.2 (group II), 3.79 +/- 0.5 (group III), 5.81 +/- 0.4 (group IV), and 7.41 +/- 0.4 mmol/l (group V). Basal glomerular filtration rate (GFR) and renal plasma flow (RPF) averaged 95 +/- 4 and 476 +/- 29 ml.1.73 m-2.min-1, respectively, and rose to 98 +/- 5 and 506 +/- 40 (group I) [P = not significant (NS)], 102 +/- 3 and 533 +/- 30 (group II) (P < 0.05 vs. basal), 110 +/- 4 and 567 +/- 29 (group III), 115 +/- 7 and 610 +/- 55 (group IV), and 117 +/- 7 and 614 +/- 66 ml.1.73 m-2.min-1 (group V) (P = NS vs. group IV). Basal plasma glucagon concentration averaged 68 +/- 10 pg/ml and increased to 74 +/- 10 (group I), 83 +/- 11 (group II) (P < 0.05 vs. basal), 100 +/- 14 (group III), 121 +/- 14 (group IV), and 229 +/- 35 pg/ml (group V) (P < 0.01 vs. basal). Increases in plasma growth hormone (GH) and insulin levels were observed only during groups IV and V.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Pathomechanism of Insulin Resistance in Men with Central Obesity: Correlation of GGT, GPx, hs-CRP and Plasma Total Cysteine

2013 ◽  
Vol 5 (2) ◽  
pp. 101 ◽  
Author(s):  
Ritawaty Ritawaty ◽  
Indriyanti Rafi Sukmawati ◽  
Ilhamjaya Patellongi ◽  
Ferry Sandra
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Amino Acid ◽  
Fatty Liver ◽  
Central Obesity ◽  
Group Iv ◽  
Group Iii ◽  
Group I ◽  
Group Ii ◽  
Hs Crp

BACKGROUND: Gamma glutamyltransferase (GGT) was reported recently to be associated with inflammation, oxidative stress and increased amino acid. However, role of GGT in insulin resistance pathomechanism is not exactly known. Therefore correlation of GGT with inflammation, oxidative stress and elevated amino acid, in men with central obesity need to be confirmed.METHODS: A cross-sectional study was designed. Men with central obesity were recruited and selected. Anthropometric parameters, creatinine, hs-CRP, fasting glucose, fasting insulin, glutathione peroxidase (GPx) activity, GGT, plasma total cysteine (tCys) and fatty liver were measured. Subjects were then divided in 4 groups based on waist circumference (WC) and fatty liver: Group I: WC ≤100 cm, without fatty liver; Group II: WC ≤100 cm, with fatty liver; Group III: WC >100 cm, without fatty liver; Group IV: WC >100 cm, with fatty liver. All biochemical characteristics in each group were then statistically analyzed.RESULTS: Seventy-two men with central obesity were selected. Numbers of subjects in each group were: Group I: n=33; Group II: n=5; Group III: n=17; Group IV: n=17. We found significant difference of HOMA-IR between Group I and IV, significant correlation between GGT and HOMAIR, and significant negative correlation between tCys with HOMA-IR in Group IV.CONCLUSION: GGT was significantly correlated with HOMA-IR in men with WC >100 cm and fatty liver. Further investigation with more subjects is necessary to determine clear GGT cut-off to distinguish subjects with fatty liver and insulin resistance.KEYWORDS: GGT, hs-CRP, GPx, tCys, HOMA-IR, insulin resistance

scholarly journals Analyses of the results in the treatment of locally advanced hypopharyngeal carcinoma with different therapeutic approach

2009 ◽  
Vol 56 (1) ◽  
pp. 35-40 ◽  
Author(s):  
A. Mikic ◽  
I. Pendjer ◽  
Z. Dudvarski ◽  
A. Trivic ◽  
M. Kreacic
Keyword(s):  
Neoadjuvant Chemotherapy ◽  
Postoperative Radiotherapy ◽  
Locally Advanced ◽  
Group Iv ◽  
Hypopharyngeal Carcinoma ◽  
Group Iii ◽  
Group I ◽  
Primary Radiotherapy ◽  
Group Ii ◽  
Number Of Authors

Introduction: treatment of locoregional advanced hypopharyngeal cancers of grades III and IV would be surgery and/or radiotherapy. An increasing number of authors has emphasized favorable effects of neoadjuvant chemotherapy and radiotherapy with potentiation. The aim: the authors presented therapeutical results of three-year survived patients with squamocellular cancers of the hypopharynx (SCC Hy), grades III and IV, in relation to specific modalities of therapeutical approach. Methods: a series of 207 patients with grades III and IV of SCC Hy, treated in the period 1982 to 2002, was analyzed. Group I consisted of 131 patients who had surgery and postoperative radiotherapy (SUR-RT). Group II included 16 patients who underwent induction chemotherapy, surgery and postoperative radiotherapy (IC-SURRT). Group III consisted of 60 patients, who had primary radiotherapy (RT). Group IV involved 29 patients who were treated, in the period 2003-2006, by neoadjuvant chemotherapy followed by radiotherapy with potentiation (CHT-RT). Results: three-year survival in Group I was 67.94%, Group II - 50%, Group III - 30%, and in Group IV was 51.72%. Five-year survival was analyzed only in group IIII. The longest survival was observed in Group I - 33.59%. Conclusion: the best therapeutical results were achieved in patient group that was primarily operated on and then had postoperative radiotherapy, while the worst survival was recorded in patients who had primary radiotherapy.

scholarly journals Microbiome signature and diversity regulates the level of energy production under anaerobic condition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Shaminur Rahman ◽  
M. Nazmul Hoque ◽  
Joynob Akter Puspo ◽  
M. Rafiul Islam ◽  
Niloy Das ◽  
...  
Keyword(s):  
Indicator Species ◽  
Energy Production ◽  
Environmental Temperature ◽  
Group Iv ◽  
Methanosarcina Barkeri ◽  
Spearman Correlation ◽  
Positive Correlation ◽  
Group Iii ◽  
Group I ◽  
Group Ii

AbstractThe microbiome of the anaerobic digester (AD) regulates the level of energy production. To assess the microbiome diversity and composition in different stages of anaerobic digestion, we collected 16 samples from the AD of cow dung (CD) origin. The samples were categorized into four groups (Group-I, Group-II, Group-III and Group-IV) based on the level of energy production (CH4%), and sequenced through whole metagenome sequencing (WMS). Group-I (n = 2) belonged to initial time of energy production whereas Group-II (n = 5), Group-III (n = 5), and Group-IV (n = 4) had 21–34%, 47–58% and 71–74% of CH4, respectively. The physicochemical analysis revealed that level of energy production (CH4%) had significant positive correlation with digester pH (r = 0.92, p < 0.001), O2 level (%) (r = 0.54, p < 0.05), and environmental temperature (°C) (r = 0.57, p < 0.05). The WMS data mapped to 2800 distinct bacterial, archaeal and viral genomes through PathoScope (PS) and MG-RAST (MR) analyses. We detected 768, 1421, 1819 and 1774 bacterial strains in Group-I, Group-II, Group-III and Group-IV, respectively through PS analysis which were represented by Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Spirochaetes and Fibrobacteres phyla (> 93.0% of the total abundances). Simultaneously, 343 archaeal strains were detected, of which 95.90% strains shared across four metagenomes. We identified 43 dominant species including 31 bacterial and 12 archaeal species in AD microbiomes, of which only archaea showed positive correlation with digester pH, CH4 concentration, pressure and temperature (Spearman correlation; r > 0.6, p < 0.01). The indicator species analysis showed that the species Methanosarcina vacuolate, Dehalococcoides mccartyi, Methanosarcina sp. Kolksee and Methanosarcina barkeri were highly specific for energy production. The correlation network analysis showed that different strains of Euryarcheota and Firmicutes phyla exhibited significant correlation (p = 0.021, Kruskal–Wallis test; with a cutoff of 1.0) with the highest level (74.1%) of energy production (Group-IV). In addition, top CH4 producing microbiomes showed increased genomic functional activities related to one carbon and biotin metabolism, oxidative stress, proteolytic pathways, membrane-type-1-matrix-metalloproteinase (MT1-MMP) pericellular network, acetyl-CoA production, motility and chemotaxis. Importantly, the physicochemical properties of the AD including pH, CH4 concentration (%), pressure, temperature and environmental temperature were found to be positively correlated with these genomic functional potentials and distribution of ARGs and metal resistance pathways (Spearman correlation; r > 0.5, p < 0.01). This study reveals distinct changes in composition and diversity of the AD microbiomes including different indicator species, and their genomic features that are highly specific for energy production.

scholarly journals Assessment of Outcome of Intrathecal Analgesia in Multiparous Women Undergoing Vaginal Delivery

2020 ◽  
Vol 5 (1) ◽  
pp. 153-155
Author(s):  
Sanjay Melville Masih ◽  
Rakesh Kumar Gupta
Keyword(s):  
Vaginal Delivery ◽  
Group Iv ◽  
Normal Vaginal Delivery ◽  
Secondary Outcome ◽  
Group Iii ◽  
Group I ◽  
Significant Difference ◽  
Multiparous Women ◽  
Group Ii ◽  
Intrathecal Analgesia

Background: The present study was conducted to assess the outcome of intrathecal analgesia in multiparous women undergoing vaginal delivery. Subjects and Methods: The present study was conducted among 80 multiparous women ages ranged 18- 40 years. All patients received 0.5 ml of intrathecal injection of 2.5 mg bupivacaine 0.5% and 1 ml dexamethasone 4 mg plus a 0.5 ml adjuvant. The adjuvants in group I patients were 100 μg morphine, 25 μg fentanyl in group II, 5 μg dexmedetomidine in group III and normal saline in group IV (control group). The primary and secondary outcome was the duration of pain relief, the analgesia onset time, the maximum level of sensory block, the visual analogue scale (VAS) was recorded. Results: The mean duration of analgesia in group I was 182.4 minutes, in group II was 170.5 minutes, in group III was 200.4 minutes and in group, IV was 140.2 minutes. The onset of analgesia was 3.9 minutes, 2.8 minutes, 2.7 minutes and 4.5 minutes in group I, II, III and IV respectively. S1 sensory regression time (minutes) was 181.4, 157.4, 185.3 and 130.6 in group I, II, III and IV respectively. Modified Bromage scale 5 minutes, 15 minutes and 30 minutes after IT in all groups was 0.0. VAS was 1.3, 1.6, 1.6 and 3.1 with significant differences in all groups (P< 0.05). There was non- significant difference in mean age, weight, height and gestational age between all groups (P> 0.05). There was a non- significant difference in APGAR 1, 5, umbilical pH immediately after delivery, neonatal HR after 5minute, 15 minutes and 30 minutes in all groups (P> 0.05). Conclusion: The authors found that dexmedetomidine is a safe and effective adjuvant to intrathecal bupivacaine-dexamethasone in multiparous women undergoing normal vaginal delivery.

Adaptive dose response pilot study of intravaginal Prostaglandin E2 application in free farrowing sows during parturition

2020 ◽  
Author(s):  
Ramona Bill ◽  
Heiko Nathues ◽  
Alexander Grahofer
Keyword(s):  
Prostaglandin E2 ◽  
Total Duration ◽  
Group Iv ◽  
Control Group ◽  
Birth Process ◽  
Group Iii ◽  
Beneficial Effects ◽  
Group I ◽  
Group Ii ◽  
Meconium Staining

Abstract Background The duration of birth is an important factor influencing the survival of piglets and the health of sows. A prolonged parturition is usually treated with oxytocin, even though several undesirable side effects are described. Therefore, the aim of this study was to evaluate the safety and efficacy of Prostaglandin E2 (PGE2) of different concentrations as an intravaginal applied gel in sows. MethodsTwelve sows were randomly allocated to one of four treatment groups: Group I (control group) application of placebo gel; Group II application of 2.0 mg PGE2; Group III application of 1.0 mg PGE2; Group IV application of 0.5 mg PGE2. The gel was administered intravaginal after the birth of the fourth piglet. Total duration of birth (time between first piglet and last placenta), piglet interval and placenta expulsion duration (time between first and last placenta) were recorded, and each piglet was scored for meconium staining and vitality. Furthermore, stillborn piglets were categorized into ante-partum and intra-partum deaths. Results Although no significant differences between the groups were detected, a beneficial tendency in several parameters was observed in group III. The duration of birth was 284 min (average of 14.3 piglets per litter), whereas in all other groups it was more than 400 min (average of 18.0 piglets per litter). The piglet interval was 10.1 min in group II compared to 10.2 min in group III, 16 min in group IV and 21.4 min in group I. In group III the placenta expulsion duration was 119 min in contrast to the other groups with more than 266 min. Severe meconium staining in more than 10% of piglets was observed in group II and IV. Moreover, piglets of group II showed oedematous and haemorrhagic umbilical cords, lethargy and anoxia, and intra-partum deaths were recorded. Conclusion Although the sample size is limited in this study, it is assumed that an application of 1mg PGE2 intra-partum instead of lower or higher dosages has the most beneficial effects on the birth process in sows and on the vitality of piglets. Further investigation is necessary to confirm the positive effect of PGE2 in daily practise.

scholarly journals Alteration of the Fatty Acid Metabolism in the Rat Kidney Caused by the Injection of Serum from Patients with Collapsing Glomerulopathy

Biomedicines ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 388
Author(s):  
Elizabeth Soria-Castro ◽  
Verónica Guarner-Lans ◽  
María Elena Soto ◽  
María del Carmen Avila-Casado ◽  
Linaloe Manzano Pech ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Acid Metabolism ◽  
Rat Kidney ◽  
Group Iv ◽  
Sprague Dawley ◽  
Group Iii ◽  
Collapsing Glomerulopathy ◽  
Fa Composition ◽  
Group I ◽  
Sprague Dawley Rats

Patients with collapsing glomerulopathy (CG) have marked proteinuria that rapidly progresses to chronic renal failure. In this study, we investigated if the nephropathy produced in a rat model by the injection of serum from CG patients induced alterations in fatty acid (FA) metabolism. Twenty-four female Sprague-Dawley rats were divided into four groups of six rats each: Group I, control rats (C); Group II, rats that received injections of 1 mL of 0.9% NaCl saline solution (SS); Group III, rats injected with 25 mg/mL of serum from healthy subjects (HS); and Group IV, rats injected with 25 mg/mL of serum from CG patients. In all groups, the systolic blood pressure (SBP), proteinuria, creatinine clearance (CC), cholesterol and total FA composition in the kidney and serum were evaluated. The administration of serum from CG patients to rats induced glomerular collapse, proteinuria, reduced CC and elevated SBP (p ≤ 0.01) in comparison with the C, SS and HS rats. The FA composition of the serum of rats that received the CG serum showed an increase in palmitic acid (PA) and a decrease in arachidonic acid (AA) when compared to serum from HS (p ≤ 0.02). In rats receiving the CG serum, there was also a decrease in the AA in the kidney but there was an increase in the PA in the serum and kidney (p ≤ 0.01). These results suggest that the administration of serum from CG patients to rats induces alterations in FA metabolism including changes in PA and in AA, which are precursors for the biosynthesis of the prostaglandins that are involved in the elevation of SBP and in renal injury. These changes may contribute to collapsing glomerulopathy disease.

scholarly journals Anaesthesia Circuits, Humidity Output, and Mucociliary Structure and Function

1998 ◽  
Vol 26 (2) ◽  
pp. 178-183 ◽  
Author(s):  
R. D. Branson ◽  
R. S. Campbell ◽  
K. Davis ◽  
D. T. Porembka
Keyword(s):  
Minute Ventilation ◽  
Absolute Humidity ◽  
Tracheobronchial Tree ◽  
Open Circuit ◽  
Structure And Function ◽  
Group Iii ◽  
Group I ◽  
Group Ii ◽  
And Function ◽  
Circuit Technique

We compared the effects of humidity delivered by the circle system at low fresh gas flows (FGF) with a conventional two-limb and coaxial circuit on the structure and function of the tracheobronchial epithelium in dogs. Animals were anaesthetized and mechanically ventilated using an anaesthesia ventilator to maintain normocarbia. Group I (control) animals received a FGF equal to the required minute ventilation mimicking an open circuit technique. Group II and III animals had FGF set at 20% of the required minute ventilation. Group II used a two-limb circuit and Group III used a coaxial circuit. Relative humidity and temperature of inspired gases were measured at baseline and hourly afterwards. In the first experiment, biopsies of the tracheobronchial tree were obtained bronchoscopically at baseline and then hourly for six hours. Microscopic examination of these samples allowed calculation of mean ciliary length. In the second experiment, tracheal mucus flow velocity (TMFV) was measured at baseline and hourly afterward, using a cinebroncho-fibrescopic method. Delivered absolute humidity was greatest with low FGF and the coaxial circuit, followed by low FGF and a conventional circuit, and high FGF (15±1.4 vs 9±0.8 vs 5±0.4 mg H2O, P<0.01) after two hours. Mean cilia length (μ m) and TMFV (mm/min) fell during the first hour in all three groups. At hour two TMFV returned to baseline in Group III and was significantly greater than Groups I and II (0.8±0.4 vs 8.6±1.1 vs 15.4±2.1, P<0.001). Mean ciliary length demonstrated a similar pattern with reductions from baseline in all three groups for the first two hours. Groups II and III had an increase in cilia length beginning at hour three and were both significantly greater than Group I at hours 3 through 6 (1.3±0.5 vs 3.2±1.1 vs 4.2±0.8, P <0.001). Alterations in tracheobronchial structure and function result from exposure to dry gases and are amplified by the duration of exposure. Our findings suggest a minimum of 12 to 15 mg H2O/l is necessary to prevent these alterations. In this study, the combination of low FGF and a coaxial anaesthesia circuit reached this minimum threshold more quickly than a conventional two-limb circuit.

Sign in / Sign up

Export Citation Format

Share Document