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1.
Encephale ; 46(3): 193-201, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32370982

ABSTRACT

OBJECTIVE: The lack of resources and coordination to face the coronavirus epidemic raises concerns for the health of patients with mental disorders in a country where we still have memories of the dramatic experience of famine in psychiatric hospitals during the Second World War. This article aims to propose guidance to ensure mental health care during the SARS-CoV epidemic in France. METHODS: The authors performed a narrative review identifying relevant results in the scientific and medical literature and in local initiatives in France. RESULTS: We identified four types of major vulnerabilities among patients with mental disorders during this pandemic: (1) medical comorbidities that are more frequently found among patients with mental disorders (cardiovascular and pulmonary pathologies, diabetes, obesity, etc.) which are risk factors for severe covid-19 infection; (2) age (the elderly form the population most vulnerable to the coronavirus); (3) cognitive and behavioural disorders, which can hamper compliance with confinement and hygiene measures and finally and (4) psychosocial vulnerability as a result of stigmatization and/or socio-economic difficulties. Furthermore, the mental health healthcare system is more vulnerable than other healthcare systems. Current government plans are poorly suited to psychiatric establishments in a context of major shortages of organizational, material and human resources. In addition, a certain number of structural aspects make the psychiatric institution particularly vulnerable: many beds have been closed, wards have high densities of patients, mental health community facilities are closed, and medical teams are understaffed and poorly trained to face infectious diseases. There are also major issues when referring patients with acute mental disorders to intensive care units. To maintain the continuity of psychiatric care in this pandemic situation, several directions can be considered, in particular with the creation of "COVID+ units". These units are under the dual supervision of a psychiatrist and an internist/infectious disease specialist; all new entrants are placed in quarantine for 14 days; the nursing staff receives specific training, daily medical check-ups and close psychological support. Family visits are prohibited and replaced by videoconference. At the end of hospitalization, in particular for the population of patients in compulsory ambulatory care situations, specific case-management are organized with the possibility of home visits, in order to support patients when they get back home and to help them cope with the experience of confinement, which is liable to induce recurrences of mental disorders. The total or partial closure of community mental health facilities is particularly disturbing for patients, but a regular follow-up is possible with telemedicine and should include the monitoring of suicide risk and psycho-education strategies; developing support platforms could also be very helpful in this context. Private practice psychiatrists also have a crucial role of information towards their patients on confinement and barrier measures, and also on measures to prevent the psychological risks inherent in confinement: maintenance of regular sleep r, physical exercise, social interactions, stress management and coping strategies, prevention of addictions, etc. They should also be trained to prevent, detect and treat early warning symptoms of post-traumatic stress disorder, because their prevalence was high in the regions of China most affected by the pandemic. DISCUSSION: French mental healthcare is now facing a great and urgent need for reorganization and must also prepare in the coming days and weeks to face an epidemic of emotional disorders due to the confinement of the general population.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Coronavirus Infections/psychology , Mental Disorders/therapy , Mental Health , Pneumonia, Viral/epidemiology , Pneumonia, Viral/psychology , Aged , Aged, 80 and over , COVID-19 , Epidemics , France/epidemiology , Hospitals, Psychiatric/organization & administration , Hospitals, Psychiatric/standards , Hospitals, Psychiatric/statistics & numerical data , Humans , Mental Disorders/epidemiology , Mental Disorders/prevention & control , Pandemics , Psychotic Disorders/epidemiology , Psychotic Disorders/therapy , Quarantine/psychology , Quarantine/statistics & numerical data , Risk Factors , SARS-CoV-2 , Stress Disorders, Post-Traumatic/epidemiology , Stress Disorders, Post-Traumatic/etiology , Stress Disorders, Post-Traumatic/therapy , Suicide/statistics & numerical data , Suicide Prevention
2.
Encephale ; 46(3S): S81-S84, 2020 Jun.
Article in French | MEDLINE | ID: mdl-32471705

ABSTRACT

OBJECTIVES: The sudden changes of healthcare system due to COVID-19 particularly affect the organization of psychiatry. The objective of this review is to examine the adaptations of psychiatric care in France during this pandemic. METHOD: This narrative review is based on the observation of changes made in French psychiatric hospitals and on an analysis of the literature. RESULTS: Regarding psychiatric hospitalization, the COVID-19 epidemic required rapid measures that profoundly modified the conditions of patients' reception, forcing the medical staffs to adapt their methods of care. The authors noted the creation of at least 89 wards specifically dedicated to patients with COVID-19 needing psychiatric hospitalization, allowing dual care of general medicine and psychiatry. Regarding ambulatory care, maintaining patients with long-term follow-up was a priority. Patients recalling and teleconsultation have been precious resources but cannot entirely replace face-to-face consultations. DISCUSSION: COVID-19 epidemic created unprecedented situation of large-scale upheavals in the healthcare system and in society. Despite the absence of previous recommendations on the subject, French psychiatry has shown great adaptability. Some changes could inspire post-COVID-19 care.


Subject(s)
Betacoronavirus , Coronavirus Infections , Hospital Restructuring , Hospitals, Psychiatric/organization & administration , Mental Health Services/organization & administration , Pandemics , Pneumonia, Viral , Psychotherapy/organization & administration , Ambulatory Care/organization & administration , Bed Conversion , COVID-19 , France/epidemiology , Health Personnel/psychology , Health Services Accessibility , Humans , Mental Disorders/epidemiology , Mental Disorders/therapy , Mental Health Services/statistics & numerical data , Mental Health Services/supply & distribution , Occupational Health , Patients' Rooms , Psychotherapy/statistics & numerical data , SARS-CoV-2 , Social Change , Stress, Psychological/etiology , Stress, Psychological/therapy , Telemedicine
3.
Encephale ; 46(3S): S3-S13, 2020 Jun.
Article in French | MEDLINE | ID: mdl-32312567

ABSTRACT

OBJECTIVE: The lack of ressources and coordination to face the epidemic of coronavirus raises concerns for the health of patients with mental disorders in a country where we keep in memory the dramatic experience of famine in psychiatric hospitals during the Second World War. This article aims at proposing guidance to ensure mental health care during the SARS-CoV epidemy in France. METHODS: Authors performed a narrative review identifying relevant results in the scientific and medical literature and local initiatives in France. RESULTS: We identified four types of major vulnerabilities in patients suffering from mental disorders during this pandemic: (1) medical comorbidities that are more frequently found in patients suffering from mental disorders (cardiovascular and pulmonary pathologies, diabetes, obesity, etc.) which represent risk factors for severe infections with Covid-19; (2) age (the elderly constituting the population most vulnerable to coronavirus); (3) cognitive and behavioral troubles which can hamper compliance with confinement and hygiene measures and finally and (4) psychosocial vulnerability due to stigmatization and/or socio-economic difficulties. Furthermore, the mental health healthcare system is more vulnerable than other healthcare systems. Current government plans are poorly adapted to psychiatric establishments in a context of major shortage of organizational, material and human resources. In addition, a certain number of structural aspects make the psychiatric institution particularly vulnerable: many beds are closed, wards have a high density of patients, mental health community facilities are closed, medical teams are understaffed and poorly trained to face infectious diseases. We could also face major issues in referring patients with acute mental disorders to intensive care units. To maintain continuity of psychiatric care in this pandemic situation, several directions can be considered, in particular with the creation of Covid+ units. These units are under the dual supervision of a psychiatrist and of an internist/infectious disease specialist; all new entrants should be placed in quarantine for 14 days; the nurse staff should benefit from specific training, from daily medical check-ups and from close psychological support. Family visits would be prohibited and replaced by videoconference. At the end of hospitalization, in particular for the population of patients in compulsory ambulatory care situations, specific case-management should be organized with the possibility of home visits, in order to support them when they get back home and to help them to cope with the experience of confinement, which is at risk to induce recurrences of mental disorders. The total or partial closure of mental health community facilities is particularly disturbing for patients but a regular follow-up is possible with telemedicine and should include the monitoring of the suicide risk and psychoeducation strategies; developing support platforms could also be very helpful in this context. Private psychiatrists have also a crucial role of information with their patients on confinement and barrier measures, but also on measures to prevent the psychological risks inherent to confinement: maintenance of sleep regularity, physical exercise, social interactions, stress management and coping strategies, prevention of addictions, etc. They should also be trained to prevent, detect and treat early warning symptoms of post-traumatic stress disorder, because their prevalence was high in the regions of China most affected by the pandemic. DISCUSSION: French mental healthcare is now in a great and urgent need for reorganization and must also prepare in the coming days and weeks to face an epidemic of emotional disorders due to the containment of the general population.


Subject(s)
Betacoronavirus , Continuity of Patient Care/organization & administration , Coronavirus Infections/epidemiology , Mental Disorders/therapy , Mental Health Services/organization & administration , Pandemics , Pneumonia, Viral/epidemiology , Aftercare , Age Factors , Aged, 80 and over , Antiviral Agents/pharmacokinetics , Antiviral Agents/therapeutic use , COVID-19 , Child , Cognition Disorders/epidemiology , Cognition Disorders/therapy , Comorbidity , Coronavirus Infections/psychology , Drug Interactions , France/epidemiology , Hospital Units/organization & administration , Hospitals, Psychiatric/organization & administration , Humans , Infection Control/methods , Mental Disorders/epidemiology , Mental Disorders/etiology , Mental Health Services/supply & distribution , Patient Care Team , Patient Compliance , Pneumonia, Viral/psychology , Prisoners/psychology , SARS-CoV-2 , Stress Disorders, Post-Traumatic/etiology , Stress Disorders, Post-Traumatic/therapy , Stress, Psychological/etiology , Stress, Psychological/therapy , Substance-Related Disorders/epidemiology , Substance-Related Disorders/therapy , Vulnerable Populations , Suicide Prevention
4.
Vox Sang ; 75(1): 7-11, 1998.
Article in English | MEDLINE | ID: mdl-9745147

ABSTRACT

BACKGROUND: International regulations for blood donation recommend a maximum donor age of 65 years. As the average population age is steadily rising in western societies, a considerable group of volunteers is lost to the donor base. STUDY DESIGN AND METHODS: In a prospective study we investigated the effect of a 450-ml whole blood donation on the physical fitness and hemorheology of regular elderly allogeneic blood donors (n = 24, aged 63-69 years, mean = 65). Results were compared with a younger group of regular donors (n = 23, aged 55-62 years, mean = 58) and a group of elderly subjects (n = 7, aged 63-66 years, mean = 65), who did not donate blood for this study. Assessing the physical fitness, we determined the submaximal physical working capacity at a heart rate of 130 min-1 (PWC 130) and the maximal working capacity (MWC) by treadmill exercise testing the day before (day -1) and after donation (d +1). The impact of the blood loss on hemorheology was examined by analyzing the plasma viscosity before, during and after donation. RESULTS: We found an increase of mean values of PWC 130 and MWC on day +1 in all study groups, but increases were only significant in the younger group (PWC 130 p = 0.03; MWC p = 0.04). Values did not differ significantly between the three groups. Plasma viscosity decreased significantly directly after donation in both groups of donors. CONCLUSION: A single blood donation did not alter the physical fitness of otherwise healthy elderly people. The older blood donors and the younger controls showed a similar compensation mechanism to blood loss. We found no general reason for disqualifying blood donors aged 65 years from donating.


Subject(s)
Aged/physiology , Blood Donors , Hemorheology , Physical Fitness , Exercise Test , Female , Hematocrit , Humans , Male , Middle Aged , Prospective Studies , Work Capacity Evaluation
5.
Article in German | MEDLINE | ID: mdl-8974710

ABSTRACT

European regulations for blood donation recommend a maximum donor age of 65 years. On the other hand, the percentage of the population in this age group is rapidly increasing in Western countries, and in autologous blood donation programs this limitation has already been abandoned. In a prospective study we examined blood donation in elderly donors (18 male and 5 female; mean age 65 years, range 64-69) in comparison to a younger control group (15/9; 58, 55-63). All donors were regular blood donors and had donated for at least 3 years. We investigated the exercise capacity before and after donation of 450 ml whole blood by examination of the physical working capacity (PWC) at heart rates of 110/min and 130/min through treadmill exercise testing and determined the blood viscosity. Additionally, whole-blood count, hemoglobin, plasma-ferritin levels and total iron binding capacity were measured immediately after donation and on days 7, 28 and 49. We found a decrease in whole-blood viscosity and a moderate increase in PWC at heart rates of 110/min and 130/min after donation in both groups. Red cell count and values of hemoglobin and ferritin were significantly lower in both groups after donation and returned to pre-donation values by day 49 in the younger control group. We detected no deterioration in exercise capacity after whole-blood donation in elderly blood donors over 65 years when compared with a younger control group. We suggest that blood donation in otherwise healthy persons aged over 65 years should be accepted.


Subject(s)
Blood Donors/legislation & jurisprudence , Physical Fitness/physiology , Aged , Blood Donors/statistics & numerical data , Blood Pressure/physiology , Blood Viscosity/physiology , Erythrocyte Count , Female , Geriatric Assessment , Germany , Heart Rate/physiology , Humans , Male , Middle Aged
6.
Eur J Biochem ; 220(2): 477-84, 1994 Mar 01.
Article in English | MEDLINE | ID: mdl-8125106

ABSTRACT

Formylmethanofuran dehydrogenases, which are found in methanogenic Archaea, are molybdenum or tungsten iron-sulfur proteins containing a pterin cofactor. We report here on differences in substrate specificity, EPR properties and susceptibility towards cyanide inactivation of the enzymes from Methanosarcina barkeri, Methanobacterium thermoautotrophicum and Methanobacterium wolfei. The molybdenum enzyme from M. barkeri (relative activity with N-formylmethanofuran = 100%) was found to catalyze, albeit at considerably reduced apparent Vmax, the dehydrogenation of N-furfurylformamide (11%), N-methylformamide (0.2%), formamide (0.1%) and formate (1%). The molybdenum enzyme from M. wolfei could only use N-furfurylformamide (1%) and formate (3%) as pseudosubstrates. The molybdenum enzyme from M. thermoautotrophicum and the tungsten enzymes from M. thermoautotrophicum and M. wolfei were specific for N-formylmethanofuran. The molybdenum formylmethanofuran dehydrogenases exhibited at 77 K two rhombic EPR signals, designated FMDred and FMDox, both derived from Mo as shown by isotopic substitution with 97Mo. The FMDred signal was only displayed by the active enzyme in the reduced form and was lost upon enzyme oxidation; the FMDox signal was displayed by an inactive form and was not quenched by O2. The tungsten isoenzymes were EPR silent. The molybdenum formylmethanofuran dehydrogenases were found to be inactivated by cyanide whereas the tungsten isoenzymes, under the same conditions, were not inactivated. Inactivation was associated with a characteristic change in the molybdenum-derived EPR signal. Reactivation was possible in the presence of sulfide.


Subject(s)
Aldehyde Oxidoreductases/metabolism , Iron-Sulfur Proteins/metabolism , Methanobacterium/enzymology , Methanosarcina barkeri/enzymology , Aldehyde Oxidoreductases/antagonists & inhibitors , Aldehyde Oxidoreductases/chemistry , Cyanides/pharmacology , Electron Spin Resonance Spectroscopy , Iron-Sulfur Proteins/antagonists & inhibitors , Iron-Sulfur Proteins/chemistry , Kinetics , Molybdenum/metabolism , Protein Conformation , Substrate Specificity , Tungsten/metabolism
7.
Eur J Biochem ; 217(2): 587-95, 1993 Oct 15.
Article in English | MEDLINE | ID: mdl-8223602

ABSTRACT

Methyl-coenzyme M reductase (MCR) catalyses the methane-forming step in the energy metabolism of methanogenic Archaea. It brings about the reduction of methyl-coenzyme M (CH3-S-CoM) by 7-mercaptoheptanoylthreonine phosphate (H-S-HTP). Methanobacterium thermoautotrophicum contains two isoenzymes of MCR, designated MCR I and MCR II, which are expressed differentially under different conditions of growth. These two isoenzymes have been separated, purified and their catalytic and spectroscopic properties determined. Initial-velocity measurements of the two-substrate reaction showed that the kinetic mechanism for both isoenzymes involved ternary-complex formation. Double reciprocal plots of initial rates versus the concentration of either one of the two substrates at different constant concentrations of the other substrate were linear and intersected on the abcissa to the left of the 1/v axis. The two purified isoenzymes differed in their Km values for H-S-HTP and for CH3-S-CoM and in Vmax. MCR I displayed a Km for H-S-HTP of 0.1-0.3 mM, a Km for CH3-S-CoM of 0.6-0.8 mM and a Vmax of about 6 mumol.min-1 x mg-1 (most active preparation). MCR II showed a Km for H-S-HTP of 0.4-0.6 mM, a Km for CH3-S-CoM of 1.3-1.5 mM and a Vmax of about 21 mumol.min-1 x mg-1 (most active preparation). The pH optimum of MCR I was 7.0-7.5 and that of MCR II 7.5-8.0. Both isoenzymes exhibited very similar temperature activity optima and EPR properties. The location of MCR I and of MCR II within the cell, determined via immunogold labeling, was found to be essentially identical. The possible basis for the existence of MCR isoenzymes in M. thermoautotrophicum is discussed.


Subject(s)
Isoenzymes/metabolism , Methane/metabolism , Methanobacterium/enzymology , Oxidoreductases/metabolism , Catalysis , Electron Spin Resonance Spectroscopy , Immunohistochemistry , Isoenzymes/chemistry , Isoenzymes/isolation & purification , Kinetics , Mesna/analogs & derivatives , Mesna/metabolism , Methanobacterium/growth & development , Oxidation-Reduction , Oxidoreductases/chemistry , Oxidoreductases/isolation & purification , Phosphothreonine/analogs & derivatives , Phosphothreonine/metabolism , Spectrophotometry, Ultraviolet
8.
Eur J Biochem ; 205(2): 759-65, 1992 Apr 15.
Article in English | MEDLINE | ID: mdl-1315276

ABSTRACT

Both components, E and S, of the adenosylcobalamin-(coenzyme B12)-dependent glutamate mutase from Clostridium cochlearium were purified. Component S (16 kDa) must be added to component E to obtain activity, although the latter contains substoichiometric amounts of component S besides the major 50-kDa subunit. The enzyme proved to be very similar to that of C. tetanomorphum as described by Barker et al. [Barker, H. A., Rooze, V., Suzuki, F. & Iodice, A. A. (1964) J. Biol. Chem. 239, 3260-3266] but component E of C. cochlearium was more stable and led to the first pure preparation. The pink component E showed a cobamide-like absorbance spectrum with a characteristic maximum at 470 nm indicating the presence of a cob(II)amide, probably Co alpha-[alpha-(aden-9-yl)]-cob(II)amide. A typical cob(II)amide signal at g = 2.23 with hyperfine and superhyperfine splitting was observed by EPR spectroscopy. A cobamide content of about 0.43 mol/mol 50-kDa subunit was determined by cyanolysis. Substitution of the migrating hydrogen at C-4 of glutamate by fluorine yielded the potent competitive inhibitor (2S,4S)-4-fluoroglutamate (Ki = 70 microM). (2R,3RS)-3-Fluoroglutamate (Ki = 600 microM) was also inhibitory. The competitive inhibition by 2-methyleneglutarate (Ki = 400 microM) and (S)-3-methylitaconate (Ki = 100 microM) but not by (RS)-2-methylglutarate suggested the transient formation of an sp2 center during catalysis. However, the presence of an N-terminal pyruvoyl residue was excluded and no evidence for the participation of another electrophilic center in the reaction was obtained.


Subject(s)
Amino Acid Isomerases/isolation & purification , Bacterial Proteins/isolation & purification , Clostridium/enzymology , Cobamides/analysis , Intramolecular Transferases , Amino Acid Isomerases/chemistry , Amino Acid Sequence , Bacterial Proteins/chemistry , Chromatography, Gel , Chromatography, Ion Exchange , Electron Spin Resonance Spectroscopy , Electrophoresis, Polyacrylamide Gel , Glutamates/pharmacology , Kinetics , Molecular Sequence Data , Protein Conformation , Spectrophotometry , Structure-Activity Relationship
9.
FEBS Lett ; 291(2): 371-5, 1991 Oct 21.
Article in English | MEDLINE | ID: mdl-1657649

ABSTRACT

The study of the nickel enzyme methyl-coenzyme M reductase from methanogenic bacteria has been hampered until now by the fact that upon cell rupture the activity of the enzyme always dropped to at best only a few percent of its in vivo activity. We describe here that when Methanobacterium thermoautotrophicum cells were preincubated with 100% H2 before disintegration methyl-coenzyme M reductase activity stayed high. The cell extracts with a specific activity of 2 U/mg protein exhibited two nickel-derived EPR signals, designated MCR-red1 and MCR-red2, previously only observed in intact cells. The enzyme was purified 10-fold to a specific activity of 20 U/mg in the presence of methyl-coenzyme M, which stabilized both the activity and the EPR signal MCR-red1. The enzyme preparation displayed an UV/Vis spectrum with an absorption maximum at 386 nm and a shoulder at 420 nm. Upon inactivation of the enzyme with O2 or CHCl3, the maximum at 386 nm and the EPR signals MCR-red1 and MCR-red2 disappeared.


Subject(s)
Hydrogen/pharmacology , Methanobacterium/enzymology , Oxidoreductases/chemistry , Electron Spin Resonance Spectroscopy , Enzyme Activation , Oxidoreductases/isolation & purification , Substrate Specificity
10.
Anat Anz ; 170(3-4): 189-97, 1990.
Article in German | MEDLINE | ID: mdl-2375498

ABSTRACT

The paper gives in a series of 3 parts a survey, quantitative statements and conclusions on the healing process of denatured orthotopic osteoresections with the initial bone obtained by, polarization optical measurements (this first part), morphological evaluation method (part II), (in these cases the collagen polymorphism served as indicator for the regeneration course) and, semiquantitative method of observation after conventionally histological treatment as well (part III). The investigations were carried out on the mandible of pigs depending on the treatment of the resected bone parts (chemical or hyperthermal denaturation in comparison with the native state). Samples of osteoreimplantions were taken in intervals of one week up to the 70th postoperative day. Histological sections were used from the different regions (contact region, gap region, border and internal regions of the resections) and investigated by the methods mentioned above. The results of the first part (polarization microscopical measurements) revealed the regular course of differentiation in the bone regeneration process: The resection is fully integrated into the initial bone after a mean duration of 112 +/- 25 days. The fastest regeneration takes place in the contact region, the slowest is found within the resection (in the case of chemical denaturation investigated).


Subject(s)
Bone Transplantation/physiology , Mandible/physiology , Wound Healing , Animals , Mandible/surgery , Mathematics , Microscopy, Polarization , Regression Analysis , Swine
11.
Article in German | MEDLINE | ID: mdl-2095646

ABSTRACT

In animal experiments on domestic pigs the behaviour of hyperthermically denatured autogenic compact bone grafts after orthotopic replantation was investigated histologically. It was shown that the inductive osteogenetic celldifferentiation of the lair tissue caused by the autogenetic osteoimplantation depends on the location relationship of the replanted bone grafts to the lair bone tissue. This differentiation had progressed after 14 and 21 days further in the upper indifference area than in the contact and fissure healing area.


Subject(s)
Bone Transplantation/methods , Osteogenesis , Animals , Bone Transplantation/pathology , Bone and Bones/cytology , Bone and Bones/physiology , Cell Differentiation , Swine , Time Factors , Wound Healing
12.
Eur J Biochem ; 172(3): 669-77, 1988 Mar 15.
Article in English | MEDLINE | ID: mdl-3350018

ABSTRACT

Methyl-coenzyme M reductase (= component C) from Methanobacterium thermoautotrophicum (strain Marburg) was highly purified via anaerobic fast protein liquid chromatography on columns of Mono Q and Superose 6. The enzyme was found to catalyze the reduction of methylcoenzyme M (CH3-S-CoM) with N-7-mercaptoheptanoylthreonine phosphate (H-S-HTP = component B) to CH4. The mixed disulfide of H-S-CoM and H-S-HTP (CoM-S-S-HTP) was the other major product formed. The specific activity was up to 75 nmol min-1 mg protein-1. In the presence of dithiothreitol and of reduced corrinoids or titanium(III) citrate the specific rate of CH3-S-CoM reduction to CH4 with H-S-HTP increased to 0.5-2 mumol min-1 mg protein-1. Under these conditions the CoM-S-S-HTP formed from CH3-S-CoM and H-S-HTP was completely reduced to H-S-CoM and H-S-HTP. Methyl-CoM reductase was specific for H-S-HTP as electron donor. Neither N-6-mercaptohexanoylthreonine phosphate (H-S-HxoTP) nor N-8-mercaptooctanoylthreonine phosphate (H-S-OcoTP) nor any other thiol compound could substitute for H-S-HTP. On the contrary, H-S-HxoTP (apparent Ki = 0.1 microM) and H-S-OcoTP (apparent Ki = 15 microM) were found to be effective inhibitors of methyl-CoM reductase, inhibition being non-competitive with CH3-S-CoM and competitive with H-S-HTP.


Subject(s)
Euryarchaeota/metabolism , Methane/biosynthesis , Oxidoreductases/metabolism , Disulfides/biosynthesis , Euryarchaeota/enzymology , Oxidation-Reduction/drug effects , Oxidoreductases/antagonists & inhibitors , Oxidoreductases/isolation & purification , Sulfhydryl Compounds/pharmacology
13.
FEBS Lett ; 213(1): 123-7, 1987 Mar 09.
Article in English | MEDLINE | ID: mdl-3104083

ABSTRACT

Purified methyl-CoM reductase of Methanobacterium thermoautotrophicum (strain Marburg) catalyzed the reduction of methyl-CoM to methane with reduced cobalamin, when either synthetic 7-mercaptoheptanoylthreonine phosphate (HS-HTP) or naturally occurring component B was present. With both compounds the same maximal specific activity was obtained and ATP was neither required nor stimulatory. These findings indicate that HS-HTP functions as component B and do not support the idea that HS-HT is only active in an adenosine monophosphorylated form.


Subject(s)
Adenosine Triphosphate/metabolism , Mercaptoethanol/analogs & derivatives , Mesna/analogs & derivatives , Methane/metabolism , Phosphothreonine/analogs & derivatives , Threonine/analogs & derivatives , Vitamin B 12/metabolism , Euryarchaeota , Kinetics , Magnesium/metabolism , Mesna/metabolism , Phosphothreonine/metabolism
18.
Article in German | MEDLINE | ID: mdl-3909673

ABSTRACT

The re-use of resident bone transplants after hyperthermic denaturalization is demonstrated in radiologically, clinically, and histologically in the lower jaw of the domestic pig. Periosteal and enosteal osteogenic effect is induced.


Subject(s)
Bone Plates , Bone Transplantation , Mandible/surgery , Wound Healing , Animals , Mandible/pathology , Swine
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