scholarly journals Giardia intestinalis Incorporates Heme into Cytosolic Cytochromeb5

2013 ◽  
Vol 13 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Jan Pyrih ◽  
Karel Harant ◽  
Eva Martincová ◽  
Robert Sutak ◽  
Emmanuel Lesuisse ◽  
...  

ABSTRACTThe anaerobic intestinal pathogenGiardia intestinalisdoes not possess enzymes for heme synthesis, and it also lacks the typical set of hemoproteins that are involved in mitochondrial respiration and cellular oxygen stress management. Nevertheless,G. intestinalismay require heme for the function of particular hemoproteins, such as cytochromeb5(cytb5). We have analyzed the sequences of eukaryotic cytb5proteins and identified three distinct cytb5groups: group I, which consists of C-tail membrane-anchored cytb5proteins; group II, which includes soluble cytb5proteins; and group III, which comprises the fungal cytb5proteins. The majority of eukaryotes possess both group I and II cytb5proteins, whereas threeGiardiaparalogs belong to group II. We have identified a fourthGiardiacytb5paralog (gCYTb5-IV) that is rather divergent and possesses an unusual 134-residue N-terminal extension. RecombinantGiardiacytb5proteins, including gCYTb5-IV, were expressed inEscherichia coliand exhibited characteristic UV-visible spectra that corresponded to heme-loaded cytb5proteins. The expression of the recombinant gCYTb5-IV inG. intestinalisresulted in the increased import of extracellular heme and its incorporation into the protein, whereas this effect was not observed when gCYTb5-IV containing a mutated heme-binding site was expressed. The electrons forGiardiacytb5proteins may be provided by the NADPH-dependent Tah18-like oxidoreductase GiOR-1. Therefore, GiOR-1 and cytb5may constitute a novel redox system inG. intestinalis. To our knowledge,G. intestinalisis the first anaerobic eukaryote in which the presence of heme has been directly demonstrated.

2000 ◽  
Vol 93 (2) ◽  
pp. 305-314 ◽  
Author(s):  
Susan A. Stern ◽  
Brian J. Zink ◽  
Michelle Mertz ◽  
Xu Wang ◽  
Steven C. Dronen

Object. Studies of isolated uncontrolled hemorrhage have indicated that initial limited resuscitation improves survival. Limited resuscitation has not been studied in combined traumatic brain injury and uncontrolled hemorrhage. In this study the authors evaluated the effects of limited resuscitation on outcome in combined fluid-percussion injury (FPI) and uncontrolled hemorrhage.Methods. Twenty-four swine weighing 17 to 24 kg each underwent FPI (3 atm) and hemorrhage to a mean arterial pressure (MAP) of 30 mm Hg in the presence of a 4-mm aortic tear. Group I (nine animals) was initially resuscitated to a goal MAP of 60 mm Hg; Group II (nine animals) was resuscitated to a goal MAP of 80 mm Hg; and Group III (control; six animals) was not resuscitated. After 60 minutes, the aortic hemorrhage was controlled and the animals were resuscitated to baseline physiological parameters and observed for 150 minutes.Mortality rates were 11%, 50%, and 100% for Groups I, II, and III, respectively (Fisher's exact test; p = 0.002). The total hemorrhage volume was greater in Group II (69 ± 32 ml/kg), as compared with Group I (41 ± 18 ml/kg) and Group III (37 ± 3 ml/kg) according to analysis of variance (p < 0.05). In surviving animals, cerebral perfusion pressure, cerebral blood flow (CBF), cerebral venous O2 saturation (ScvO2), and cerebral metabolic rate of O2 did not differ among groups. Although CBF was approximately 50% of baseline during the period of limited resuscitation in Group I, ScvO2 remained greater than 60%, and arteriovenous O2 differences remained within normal limits.Conclusions. In this model of FPI and uncontrolled hemorrhage, early aggressive resuscitation, which is currently recommended, resulted in increased hemorrhage and failure to optimize cerebrovascular parameters. In addition, a 60-minute period of moderate hypotension (MAP = 60 mm Hg) was well tolerated and did not compromise cerebrovascular hemodynamics, as evidenced by physiological parameters that remained within the limits of cerebral autoregulation.


2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Pradeep Neupane ◽  
Sindhura Sevala ◽  
Nandhakumar Balakrishnan ◽  
Henry Marr ◽  
James Wilson ◽  
...  

ABSTRACT Bartonella spp. are etiological agents of life-threatening zoonotic diseases in dogs worldwide. Due to the poor sensitivity of immunofluorescent-antibody assays (IFAs), a reliable serodiagnostic test for canine bartonelloses is of clinical importance. The utility of Western blotting (WB) for the serodiagnosis of canine bartonelloses has not been critically investigated. The objective of this study was to characterize WB immunodominant proteins that could be used to confirm a serodiagnosis of bartonelloses. Using agar-grown Bartonella henselae San Antonio type 2 (SA2) whole-cell proteins, sera derived from four dog groups were tested by WB to assess immunodominant protein recognition patterns: group I consisted of 92 serum samples (10 preexposure and 82 postexposure serum samples) from 10 adult beagles experimentally inoculated with Bartonella spp., group II consisted of 36 serum samples from Bartonella PCR-positive naturally infected dogs, group III consisted of 26 serum samples from Bartonella PCR-negative and IFA-negative dogs, and group IV consisted of serum samples from 8 Brucella canis IFA-positive and 10 Rickettsia rickettsii IFA-positive dogs. Following experimental inoculation, 9 (90%) group I dogs were variably seroreactive to one or more of six specific immunodominant proteins (13, 17, 29, 50, 56, and 150 kDa). There was a strong but variable recognition of these proteins among 81% of group II dogs. In contrast, 24/26 group III dogs were not reactive to any immunodominant protein. In this study, the sensitivity and diagnostic accuracy of B. henselae SA2 WB were higher than those of B. henselae SA2 IFA testing. Some B. henselae SA2 immunodominant proteins were recognized by dogs experimentally and naturally infected with Bartonella spp. other than B. henselae. Additional research is necessary to more fully define the utility of WB for the serodiagnosis of canine bartonelloses.


2005 ◽  
Vol 103 (6) ◽  
pp. 1046-1051 ◽  
Author(s):  
Mohammad A. Jamous ◽  
Shinji Nagahiro ◽  
Keiko T. Kitazato ◽  
Junichiro Satomi ◽  
Koichi Satoh

Object. Estrogen has been shown to play a central role in vascular biology. Although it may exert beneficial vascular effects, its role in the pathogenesis of cerebral aneurysms remains to be determined. To elucidate the role of hormones further, the authors examined the effects of bilateral oophorectomy on the formation and progression of cerebral aneurysms in rats. Methods. Forty-five female, 7-week-old Sprague—Dawley rats were divided into three equal groups. Group I consisted of intact rats (controls). To induce cerebral aneurysms, the animals in Groups II and III were subjected to ligation of the right common carotid and bilateral posterior renal arteries. One month later, the rats in Group II underwent bilateral oophorectomy. Three months after the experiment began all animals were killed and cerebral vascular corrosion casts were prepared and screened for cerebral aneurysms by using a scanning electron microscope. Plasma was used to determine the level of estradiol and the gelatinase activity. Hypertension developed in all rats except those in the control group. The estradiol level was significantly lower in Group II than in the other groups (p < 0.01). The incidence of cerebral aneurysm formation in Group II (60%) was three times higher than that in Group III (20%), and the mean size of aneurysms in Group II (76 ± 27 µm, mean ± standard deviation) was larger than that in Group III (28 ± 4.6 µm) (p < 0.05). No aneurysm developed in control animals (Group I), and there was no significant difference in plasma gelatinase activity among the three groups. Conclusions. The cerebral aneurysm model was highly reproducible in rats. Bilateral oophorectomy increased the susceptibility of rats to aneurysm formation, indicating that hormones play a role in the pathogenesis of cerebral aneurysms.


1989 ◽  
Vol 71 (6) ◽  
pp. 923-928 ◽  
Author(s):  
Toshio Matsushima ◽  
Satoshi O. Suzuki ◽  
Masashi Fukui ◽  
Albert L. Rhoton ◽  
Evandro de Oliveira ◽  
...  

✓ Variations of the tentorial sinus of cadaver cerebellar tentoria were examined under a surgical microscope. The tentorial sinuses were classified into four groups: Group I, in which the sinus receives venous blood from the cerebral hemisphere; Group II, in which the sinus drains the cerebellum; Group III, in which the sinus originates in the tentorium itself; and Group IV, in which the sinus originates from a vein bridging to the tentorial free edge. The tentorial sinuses of Groups I and II were frequently located in the posterior portion of the tentorium. The sinuses of Group I were short and most frequently present in the lateral portion of the tentorium. The tentorial sinuses of Group II, which were usually large and drained into the dural sinuses near the torcular, were separated into five subtypes according to the draining veins and direction of termination. The tentorial sinuses of Groups III and IV were located near the tentorial free edge or the straight sinus. The draining patterns of the tentorial sinuses and their draining veins (so-called “bridging veins”) were present in most cases. Knowledge of this anatomy can benefit the neurosurgeon carrying out repair near or on the cerebellar tentorium.


1986 ◽  
Vol 65 (6) ◽  
pp. 745-750 ◽  
Author(s):  
Ann R. Stroink ◽  
Harold J. Hoffman ◽  
E. Bruce Hendrick ◽  
Robin P. Humphreys

✓ The authors reviewed the cases of 49 children, ranging in age from 9 months to 15 years, who were diagnosed by computerized tomography (CT) as having brain-stem glioma. Four distinct groups of brain-stem gliomas were identified based on CT scan characteristics: Group I included isodense contrast-enhancing tumors that were dorsally exophytic into the fourth ventricle; Group II(a) included hypodense nonenhancing intrinsic tumors of the brain stem; Group II(b) included intrinsic tumors of the brain stem with hyperdense exophytic components extending ventrally and laterally into the cerebellopontine and prepontine cisterns; Group III included intrinsic cystic tumors with contrast-enhancing capsules; and Group IV included focally intrinsic tumors of the brain stem that were isodense and enhanced brightly on administration of contrast medium. The clinical presentation, efficacy of surgical intervention, pathology, and prognosis of these tumors were correlated within these groupings. Eleven patients had Group I tumors, all of which were surgically resected; 10 of the 11 lesions were proven to be low-grade gliomas. These patients had an excellent prognosis; 10 of the 11 survived, with a mean follow-up period of 4.5 years. There were 18 patients with Group II(a) tumors; although tumor biopsy was attempted on eight of these, pathological diagnosis at the time of surgery was made in only one case. These patients did poorly; the mean survival time was 6.2 months. The seven Group II(b) tumor patients demonstrated a similarly poor prognosis: all of them died within 23 months of diagnosis, with a mean survival time of 12 months. Only two of six patients undergoing biopsy had sufficient tissue for histological verification. Three of the four patients with Group III tumors died; their mean survival time was 11.5 months. Successful histological examination was carried out in all four cases. The nine Group IV tumor patients did reasonably well; seven of these patients remain alive, with a mean follow-up period of 2.3 years. Histological diagnosis was obtained in three of the seven patients who were explored in this group. This classification system has proven to be of value in determining prognosis and efficacy of surgical intervention.


Author(s):  
K.K. SEKHRI ◽  
C.S. ALEXANDER ◽  
H.T. NAGASAWA

C57BL male mice (Jackson Lab., Bar Harbor, Maine) weighing about 18 gms were randomly divided into three groups: group I was fed sweetened liquid alcohol diet (modified Schenkl) in which 36% of the calories were derived from alcohol; group II was maintained on a similar diet but alcohol was isocalorically substituted by sucrose; group III was fed regular mouse chow ad lib for five months. Liver and heart tissues were fixed in 2.5% cacodylate buffered glutaraldehyde, post-fixed in 2% osmium tetroxide and embedded in Epon-araldite.


1998 ◽  
Vol 80 (09) ◽  
pp. 393-398 ◽  
Author(s):  
V. Regnault ◽  
E. Hachulla ◽  
L. Darnige ◽  
B. Roussel ◽  
J. C. Bensa ◽  
...  

SummaryMost anticardiolipin antibodies (ACA) associated with antiphospholipid syndrome (APS) are directed against epitopes expressed on β2-glycoprotein I (β2GPI). Despite a good correlation between standard ACA assays and those using purified human β2GPI as the sole antigen, some sera from APS patients only react in the latter. This is indicative of heterogeneity in anti-β2GPI antibodies. To characterize their reactivity profiles, human and bovine β2GPI were immobilized on γ-irradiated plates (β2GPI-ELISA), plain polystyrene precoated with increasing cardiolipin concentrations (CL/β2GPI-ELISA), and affinity columns. Fluid-phase inhibition experiments were also carried out with both proteins. Of 56 selected sera, restricted recognition of bovine or human β2GPI occurred respectively in 10/29 IgA-positive and 9/22 IgM-positive samples, and most of the latter (8/9) were missed by the standard ACA assay, as expected from a previous study. Based on species specificity and ACA results, IgG-positive samples (53/56) were categorized into three groups: antibodies reactive to bovine β2GPI only (group I) or to bovine and human β2GPI, group II being ACA-negative, and group III being ACA-positive. The most important group, group III (n = 33) was characterized by (i) binding when β2GPI was immobilized on γ-irradiated polystyrene or cardiolipin at sufficient concentration (regardless of β2GPI density, as assessed using 125I-β2GPI); (ii) and low avidity binding to fluid-phase β2GPI (Kd in the range 10–5 M). In contrast, all six group II samples showed (i) ability to bind human and bovine β2GPI immobilized on non-irradiated plates; (ii) concentration-dependent blockade of binding by cardiolipin, suggesting epitope location in the vicinity of the phospholipid binding site on native β2GPI; (iii) and relative avidities approximately 100-fold higher than in group III. Group I patients were heterogeneous with respect to CL/β2GPI-ELISA and ACA results (6/14 scored negative), possibly reflecting antibody differences in terms of avidity and epitope specificity. Affinity fractionation of 23 sera showed the existence, in individual patients, of various combinations of antibody subsets solely reactive to human or bovine β2GPI, together with cross-species reactive subsets present in all samples with dual reactivity namely groups III and II, although the latter antibodies were poorly purified on either column. Therefore, the mode of presentation of β2GPI greatly influences its recognition by anti-β2GPI antibodies with marked inter-individual heterogeneity, in relation to ACA quantitation and, possibly, disease presentation and pathogenesis.


2015 ◽  
Vol 18 (3) ◽  
pp. 098
Author(s):  
Cem Arıtürk ◽  
Serpil Ustalar Özgen ◽  
Behiç Danışan ◽  
Hasan Karabulut ◽  
Fevzi Toraman

<p class="p1"><span class="s1"><strong>Background:</strong> The inspiratory oxygen fraction (FiO<sub>2</sub>) is usually set between 60% and 100% during conventional extracorporeal circulation (ECC). However, this strategy causes partial oxygen pressure (PaO<sub>2</sub>) to reach hyperoxemic levels (&gt;180 mmHg). During anesthetic management of cardiothoracic surgery it is important to keep PaO<sub>2</sub> levels between 80-180 mmHg. The aim of this study was to assess whether adjusting FiO<sub>2</sub> levels in accordance with body temperature and body surface area (BSA) during ECC is an effective method for maintaining normoxemic PaO<sub>2</sub> during cardiac surgery.</span></p><p class="p1"><span class="s1"><strong>Methods:</strong> After approval from the Ethics Committee of the University of Acıbadem, informed consent was given from 60 patients. FiO<sub>2</sub> adjustment strategies applied to the patients in the groups were as follows: FiO<sub>2</sub> levels were set as 0.21 × BSA during hypothermia and 0.21 × BSA + 10 during rewarming in Group I; 0.18 × BSA during hypothermia and 0.18 × BSA + 15 during rewarming in Group II; and 0.18 × BSA during hypothermia and variable with body temperature during rewarming in Group III. Arterial blood gas values and hemodynamic parameters were recorded before ECC (T1); at the 10th minute of cross clamp (T2); when the esophageal temperature (OT) reached 34°C (T3); when OT reached 36°C (T4); and just before the cessation of ECC (T5).</span></p><p class="p1"><span class="s1"><strong>Results:</strong> Mean PaO<sub>2</sub> was significantly higher in Group I than in Group II at T2 and T3 (<em>P</em> = .0001 and <em>P</em> = .0001, respectively); in Group I than in Group III at T1 (<em>P</em> = .02); and in Group II than in Group III at T2, T3, and T4 <br /> (<em>P</em> = .0001 for all). </span></p><p class="p1"><span class="s1"><strong>Conclusion: </strong>Adjustment of FiO<sub>2</sub> according to BSA rather than keeping it at a constant level is more appropriate for keeping PaO<sub>2</sub> between safe level limits. However, since oxygen consumption of cells vary with body temperature, it would be appropriate to set FiO<sub>2</sub> levels in concordance with the body temperature in the <br /> rewarming period.</span></p>


2016 ◽  
pp. 108-111
Author(s):  
T.F. Tatarchuk ◽  
◽  
D.G. German ◽  

The article presents the comparative analysis of the state of the cervix in women with endometrial polyps and micropolyps. Patients and methods. The study involved 130 patients aged 18-35 years: 70 patients with endometrial polyps (group I), 30 patients with micropolyps (group II) and 30 patients of the control group (group III). Results. According to the anamnesis of women in the I group were significantly more frequent diseases of the cervix, which corrected physical surgery methods, in particular cryodestruction. In group II, the representatives of these indicators were similar to healthy. Normal colposcopic picture met significantly less frequently in patients and I, and II group. The differences in the incidence of HPV high oncogenic risk in all groups were not statistically significant. Conclusion. Destructive methods used in the detection of any changes in the cervix are often overly aggressive, form scars and contributing to inflamaciones process. In the chain of events leading to the formation of PE, cervical pathology and its correction can take the basic place. Key words: endometrial polyp, micropolyps, chronic endometritis, uterine cervix, colposcopy.


Author(s):  
Г.В. ШИРЯЕВ ◽  
Ю.Г. ТУРЛОВА ◽  
Г.С. НИКИТИН

Изучено влияние кормовой добавки в форме индивидуальных болюсов Метраболь на возможность снижения негативного влияния субклинического кетоза (СКК) и результативность искусственного осеменения высокопродуктивных молочных коров в посттранзитный период. Животные были подобраны по принципу условных аналогов и разделены на 3 группы в зависимости от концентрации β-оксимасляной кислоты в их крови. В I группе (n=18) у коров не было СКК, концентрация кислоты составляла <1,0 ммоль/л, во II группе (n=21) у животных зарегистрирован СКК, концентрация кислоты — 1,0…1,4 ммоль/л. С целью поиска решения по снижению негативного влияния СКК на репродуктивные показатели была сформирована III группа коров, переболевших СКК (n=24) с концентрацией β-оксимасляной кислоты в крови 1,0…1,4 ммоль/л, но с использованием болюсов, применяемых для ускоренного восстановления репродуктивной функции коров после отела. Важной составляющей опыта явилось то, что к моменту гормональной синхронизации у коров всех 3 групп фиксировалось отсутствие СКК (снижение β-оксимасляной кислоты до уровня <1,0 ммоль/л). Для синхронизации полового цикла выбрана схема Пресинх-овсинх. Установлено, что гормональная синхронизация животных, перенесших СКК, в сравнении со здоровыми, не позволяет снизить негативное влияние данного нарушения обмена веществ. Во II группе у животных зафиксированы самые низкие репродуктивные показатели (количество использованных доз; индекс осеменения, сервис-период; время от первого до успешного осеменения; результат первичного осеменения; количество животных, осемененных 3 и более раз). В III группе применение болюсов позволило, в сравнении с животными II группы, не только избежать отрицательного воздействия СКК, но и превзойти по изучаемым параметрам животных из I группы. The effect of the feed additive in the form of individual boluses Metrabol on the possibility of reducing the negative effect of subclinical ketosis (CCK) and the effectiveness of artificial insemination of highly productive dairy cows in the post-transit period was studied. The animals were selected according to the principle of conditional analogs and divided into 3 groups depending on the concentration of β-hydroxybutyric acid in their blood. In group I (n=18), the cows did not have SSC, the acid concentration was <1.0 mmol/L, in group II (n=21), SSC was registered in animals — 1.0...1.4 mmol / L. In order to find a solution to reduce the negative effect of CCB on reproductive indices, a group III of cows was formed who had CCB (n = 24) with a concentration of β-hydroxybutyric acid in their blood of 1.0...1.4 mmol/L, but using boluses, used to accelerate the restoration of the reproductive function of cows after calving. An important component of the experiment was that by the time of hormonal synchronization, cows of all 3 groups had no SSC (decrease in β-hydroxybutyric acid to a level of <1.0 mmol/L). To synchronize the sexual cycle, the Pressinh-ovsinh scheme was chosen. It was found that hormonal synchronization of animals that underwent SSC, in comparison with healthy ones, does not allow reducing the negative effect of this metabolic disorder. In group II, animals had the lowest reproductive indices (number of doses used; insemination index, service period; time from first to successful insemination; result of primary insemination; number of animals inseminated 3 or more times). In group III, the use of boluses made it possible, in comparison with animals of group II, not only to avoid the negative effect of SSC, but also to surpass the animals from group I in terms of the studied parameters.


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