Clinical features and outcomes in adults with COVID-19 during the pre-Omicron and Omicron waves.

OBJECTIVES: We conducted a single-center retrospective study to compare patient characteristics and death rates during the Omicron (O, December 01, 2021, to September 30, 2022) and pre-Omicron (PO, March 01, 1920, to October 31, 2021) periods. PATIENTS AND METHODS: We retrospectively analyzed the data of 2932 patients (1242 (O) and 1690 (PO)) hospitalized (>24 h) with laboratory-confirmed COVID. RESULTS: Compared to the PO period, O period patients were less frequently men, had a lower body mass index and fewer comorbidities except for immunosuppression and pregnancy. Nosocomial COVID-19 accounted for 18.2 % (O) and 15.4 % (PO) of cases (p = 0.05). Patient mortality rates during the O and PO periods were 11.0 % and 16.9 % (p < 0.001), respectively. Unvaccinated status (p < 0.001), existence of comorbidities, (p < 0.001) and high LDH value at baseline (p = 0.015), but not the period, were identified as factors likely to explain death. CONCLUSION: During the Omicron period, the inpatient death rate remained > 10 %, especially among unvaccinated and comorbid patients. Nosocomial cases were more frequent.

Characteristic and outcome changes in inpatients with COVID-19 during the four pre - Omicron waves.

Background: Four waves of Coronavirus disease 2019 (COVID-19) occurred in France between March 2020 and September 2021. COVID-19 inpatient characteristics change because of the influence of numerous parameters, especially immunization and circulating severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) variants. Methods: This retrospective single-center study analyzed patients with laboratory-proven COVID-19 admitted from 1/3/2020 to 30/6/2020 (wave one), 1/7/2020 to 31/12/2020 (wave two), 1/1/2021 to 30/6/2021 (wave three), and 1/7/2021 to 30/11/2021 (wave four). We compared the outcomes and baseline characteristics between these waves. Results: In our center, 1,762 patients were hospitalized for COVID-19: 666 (37.8 %), 425 (24.1 %), 482 (27.3 %), and 189 (10.7 %) during waves 1, 2, 3, and 4, respectively. Patients during the first wave were hospitalized later after the onset of COVID-19 symptoms, had more severe disease conditions at baseline, and suffered higher intensive care unit (ICU) hospitalization rates. Most patients from waves 1-3 were >70 years old, with 88-93 % having ≥1 comorbidity, whereas those from wave four were younger (68.0 years) with less comorbidities. The first two waves showed higher mortality rates (16.8 % and 20.0 %) than the latter (16.6 % and 9.5 %). Conclusion: Patients during the first wave had more severe disease conditions at baseline and higher mortality and ICU hospitalization rates. Despite the more virulent circulating Delta variant during wave four, the death and hospitalization rates were markedly decreased during wave four. HIPPOKRATIA 2023, 27 (1):1-6.

Evolution of baseline characteristics and severe outcomes in COVID-19 inpatients during the first and second waves in Northeastern France.

OBJECTIVES: Two COVID-19 epidemic waves occurred in France in 2020. This single-center retrospective study compared patients' characteristics and outcomes. PATIENTS AND METHODS: We included all patients with confirmed COVID-19 admitted to Colmar Hospital in March (n=600) and October/November (n=205) 2020. RESULTS: Median ages, sex ratio, body mass index, and number of comorbidities were similar in wave 1 and 2 patients. Significant differences were found for temperature (38°C vs. 37.2), need for oxygen (38.6% vs. 26.8%), high-flow cannula (0% vs. 8.3%), and steroid use (6.3% vs. 54.1%). Intensive care unit (ICU) hospitalizations (25.5% vs. 15.1%, OR: 0.44, 95% CI [0.28; 0.68], P=0.002) and deaths (19.2% vs. 12.7%, OR: 0.61, 95% CI [0.37; 0.98], P=0.04) decreased during the second wave. Except for cardiovascular events (5.5% vs. 10.2%), no change was observed in extrapulmonary events. CONCLUSIONS: Deaths and ICU hospitalizations were significantly reduced during the second epidemic wave.

Protection of protein from ruminal degradation by alkali-induced oxidation of chlorogenic acid in sunflower meal.

Lactating ruminants require an adequate supply of absorbable amino acids for the synthesis of milk protein from two sources, that is crude protein (CP) synthesized microbially in the rumen and ruminally undegraded CP (RUP) from feed which can both be digested in the small intestine. Several chemical and physical methods have been identified as being effective in increasing the proportion of RUP of total CP of a feedstuff, yet there is a continuing need for developing and establishing methods which protect feed protein from ruminal degradation with acceptable expenditure of labour and other costs. The objective of this study was to identify and quantify effects of and interactions between chlorogenic acid and protein in solvent-extracted sunflower meal (SFM) as induced by alkali treatment. Response surface methodology was employed to investigate the influence of pH, reaction time and drying temperature on the resulting SFM and, subsequently, its protein value for ruminants estimated from laboratory values. For this purpose, alkali-treated SFM was subjected to a fractionation of feed CP according to the Cornell net carbohydrate and protein system as a basis for estimating RUP at different assumed ruminal passage rates (Kp ). To estimate the intestinal digestibility of the treated SFM and its RUP, a three-step enzymatic in vitro procedure was applied. Alkaline treatment of SFM increased RUP values with factors ranging from approximately 3 (Kp =.08/hr) to 12 (Kp =.02/hr). Furthermore, the intestinal digestibility of the alkali-treated SFM was enhanced by approximately 10% compared to untreated SFM. Increasing pH and reaction time led to both increasing RUP values and intestinal digestibility. In conclusion, a targeted alkaline treatment of naturally occurring compounds in feedstuffs might be a promising approach to provide high-RUP feeds for ruminants which, at the same time, have improved intestinal digestibility values.

Antifungal activity of secondary plant metabolites from potatoes (Solanum tuberosum L.): Glycoalkaloids and phenolic acids show synergistic effects.

AIMS: To study the antifungal effects of the potato secondary metabolites α-solanine, α-chaconine, solanidine and caffeic acid, alone or combined. METHODS AND RESULTS: Resistance to glycoalkaloids varied among the fungal species tested, as derived from minimum inhibitory concentrations assays. Synergistic antifungal activity between glycoalkaloids and phenolic compounds was found. Changes in the fluidity of fungal membranes caused by potato secondary plant metabolites were determined by calculation of the generalized polarization values. The results partially explained the synergistic effect between caffeic acid and α-chaconine and supported findings on membrane disruption mechanisms from previous studies on artificial membranes. LC/MS analysis was used to determine variability and relative amounts of sterols in the different fungal species. Results suggested that the sterol pattern of fungi is related to their resistance to potato glycoalkaloids and to their taxonomy. CONCLUSION: Fungal resistance to α-chaconine and possibly other glycoalkaloids is species dependent. α-Chaconine and caffeic acid show synergistic antifungal activity. The taxonomic classification and the sterol pattern play a role in fungal resistance to glycoalkaloids. SIGNIFICANCE AND IMPACT OF THE STUDY: Results improve the understanding of the antifungal mode of action of potato secondary metabolites, which is essential for their potential utilization as antifungal agents in nonfood systems.

Structure-function relationships of the antibacterial activity of phenolic acids and their metabolism by lactic acid bacteria.

AIMS: To determine structure-function relationships of antibacterial phenolic acids and their metabolites produced by lactic acid bacteria (LAB). METHODS AND RESULTS: Minimum inhibitory concentrations (MICs) of 6 hydroxybenzoic and 6 hydroxycinnamic acids were determined with Lactobacillus plantarum, Lactobacillus hammesii, Escherichia coli and Bacillus subtilis as indicator strains. The antibacterial activity of phenolic acids increased at lower pH. A decreasing number of hydroxyl groups enhanced the activity of hydroxybenzoic acids, but had minor effects on hydroxycinnamic acids. Substitution of hydroxyl groups with methoxy groups increased the activity of hydroxybenzoic, but not of hydroxycinnamic, acid. Metabolism of chlorogenic, caffeic, p-coumaric, ferulic, protocatechuic or p-hydroxybenzoic acids by L. plantarum, L. hammesii, Lactobacillus fermentum and Lactobacillus reuteri was analysed by LC-DAD-MS. Furthermore, MICs of substrates and metabolites were compared. Decarboxylated and/or reduced metabolites of phenolic acids had a lower activity than the substrates. Strain-specific metabolism of phenolic acids generally corresponded to resistance. CONCLUSIONS: The influence of lipophilicity on the antibacterial activity of hydroxybenzoic acids is stronger than that of hydroxycinnamic acids. Metabolism of phenolic acids by LAB detoxifies phenolic acids. SIGNIFICANCE AND IMPACT OF THE STUDY: Results allow the targeted selection of plant extracts for food preservation, and selection of starter cultures for fermented products.

Ascertainment of D-amino acids in germ-free, gnotobiotic and normal laboratory rats.

Free D-amino acids were ascertained in the blood serum, urine and aqueous ethanolic extracts of feces of germ-free laboratory rats and a rat made gnotobiotic (tetra-associated) with species of Streptococcus, Lactobacillus and Clostridium. D-Amino acids were also determined in the brains of two germ-free rats. For comparison, D-amino acids were also measured in the blood serum of normal rats and the blood plasma, urine and feces of normal white mice. D-Enantiomers of most protein L-amino acids were detected in all physiological samples of animals. Quantities of free D-amino acids were determined as N(O)-pentafluoropropionyl-(2)-propyl esters by enantioselective gas chromatography and mass spectrometry. Stereoisomers of the bacterial marker 2,6-diaminopimelic acid, analyzed as N-trifluoroacetyl-(2)-propyl esters, were detected in feces of the gnotobiotic but not of the germ-free rat.

Determination of amino acid enantiomers in human urine and blood serum by gas chromatography-mass spectrometry.

Amino acid (AA) enantiomers were determined as N(O)-pentafluoropropionyl-(2)-propyl esters by chiral gas chromatography-mass spectrometry (GC-MS) in 24 h samples of the urine of three healthy volunteers and in their blood sera. In urine the largest amounts were determined for D-Ser (64-199 micromol/day) and D-Ala (24-138 micromol/day). In blood sera, D-Ala (2.3-4.2 micromol/L) and D-Ser (1.0-2.9 micromol/L) were most abundant. Varying amounts of the D-enantiomers of Thr, Pro, Asx, Glx, Phe, Tyr, Orn and Lys were also found, albeit not in all urines and sera. Further, enantiomers were quantified in urine samples of two volunteers fasting for 115 h. Quantities of renally excreted D-AAs decreased in fasting, although amounts of D-Ser (69 and 77 micromol/L urine) as well as other D-AAs were still detectable. Time-dependent analyses of urine showed that D-AAs are continuously excreted.

Determination of phenolic acids and flavonoids of apple and pear by high-performance liquid chromatography.

A new HPLC stationary phase has been applied to the analysis of phenolic acids and flavonoids with diode array and mass spectrometric detection. The separation of 26 standard compounds was achieved within 1 h. The stationary phase displayed excellent resolution especially of flavonol glycosides. The analytical system has been used for the determination of phenolic compounds in apple pomace and apple juice, and in extracts of pear fruits of different cultivars. Apple pomace was found to be a promising source of phenolics. However, yields are affected by the drying conditions applied. Furthermore, the applicability of the analytical system for the authenticity control of apple and pear juice was demonstrated by determination of characteristic quercetin and isorhamnetin glycosides, and dihydrochalcones, respectively. Since isorhamnetin-3-glucoside was present in all pear cultivars investigated, the usefulness of arbutin as a specific marker of pear products appears to be doubtful.

Local administration of ramiprilat is less effective than oral ramipril in preventing restenosis after balloon angioplasty in an animal model.

PURPOSE: To test the hypothesis that local administration of angiotensin converting enzyme (ACE) inhibitor via a microporous balloon catheter would be more effective than oral administration of ACE inhibitor in preventing neointima formation after balloon angioplasty. MATERIALS AND METHODS: Neointima formation was induced by balloon denudation followed by 0.5% cholesterol diet in 29 New Zealand White rabbits. Directly after denudation, local administration of 1.8 mg of ramiprilat (n = 7) or saline (n = 7) with a microporous balloon catheter at a pressure of 3 atm was performed. Both groups additionally received ramipril orally (1 mg/d). Seven animals were treated exclusively with oral ramipril. The control group was fed a 0.5% cholesterol diet and given no medication (n = 8). Six weeks after intervention, the animals were killed and morphometric and immunohistologic analyses were performed. RESULTS: Oral administration of ramipril resulted in a significant reduction of placque area (-66%, P < .05). Oral and local administration of the ACE inhibitor was followed by a nonsignificant reduction of the neointimal area (-17%). Local administration of saline combined with oral ramipril failed to prevent neointimal formation (reduction of 6%, NS). CONCLUSION: Oral administration of ramipril resulted in a significant reduction of neointimal proliferation in New Zealand White rabbits. The possible benefit of an additional administration of local ramiprilat was diminished by an excessive neointimal hyperplasia, which was most likely caused by the inherent vessel trauma with use of the microporous balloon catheter.

GC-MS analysis of diaminopimelic acid stereoisomers and amino acid enantiomers in rumen bacteria.

The amounts and the configuration of the stereoisomers of 2,6-diaminopimelic acid (Dap) and the enantiomeric content of other amino acids were determined in five individual species (Fibrobacter succinogenes, Streptococcus bovis, Selenomonas ruminantium, Prevotella ruminicola and Anaerovibrio lipolytica) of rumen bacteria, and in samples of mixed rumen bacteria isolated from sheep. The separation and quantification of the Dap stereoisomers was achieved by gas chromatography (GC) of trifluoroacetyl 2-propyl esters on a Chirasil-L-Val fused silica column, and detection was achieved by selected ion monitoring mass spectrometry (SIM-MS). No isomers of Dap were detected in S. bovis and P. ruminicola, two of the bacterial isolates. LL- and DD-Dap were not detected in any of the bacterial samples. As only the meso-isomer of Dap was detected in these microorganisms, it was quantified by adding LL-Dap as an internal standard before the bacteria were acid-hydrolyzed. Amounts of between 4.8 and 12.0 mg meso-Dap per gram of bacterial dry matter (DM) were determined. The presence in the rumen bacteria of free amino acid enantiomers, extractable with 70% aqueous ethanol, were determined by GC-SIM-MS; the D-amino acids were predominantly Ala, Asp and Glu, but there was considerable variation between the species.

Amino acid composition and betaxanthin formation in fruits from Opuntia ficus-indica.

In contrast to earlier reports high levels of taurine (2-aminoethanesulfonic acid) were found in fruit juices of three cultivars of Opuntia ficus-indica (L.) Mill. Whereas the occurrence of taurine in plant tissue was thought to be restricted to algae, fungi, and the endosperm of some higher plants, prickly pear proved to be a rich source of dietary taurine. Using L-taurine as the amino compound, a new betaxanthin was synthesized by partial synthesis. On the basis of chemical and spectral evidence its structure was determined to be the taurine-immonium-conjugate of betalamic acid. Also betalamic acid could be detected in yellow and orange coloured cultivars of Opuntia ficus-indica for the first time. In spite of the high levels of L-taurine accompanied by the occurrence of betalamic acid, the corresponding betaxanthin could not be detected in the fruit tissue.

[Intra-arterial application of the ACE inhibitor ramipril using a microperforated catheter for the prevention of neointimal proliferation after angioplasty in an animal model]. / Intraarterielle Applikation des ACE-Hemmers Ramipril über mikroperforierte Katheter zur Prävention der Neointimaproliferation nach Angioplastie am Tiermodell.

PURPOSE: To evaluate the safety and benefit of a high-dose local drug administration via a microporous balloon catheter to prevent neointimal formation after balloon angioplasty. MATERIALS AND METHODS: In New Zealand white rabbits (n = 29) neointima formation was induced by balloon denudation. Additionally, the animals were fed a 0.5% cholesterol diet for 6 weeks. Directly after the denudation, local application of 1.8 mg ramipril (n = 7) or saline (n = 7) via a microporous balloon catheter was performed. Other animals (n = 7) were treated with a systemic ramipril administration. One control group were exclusively fed with a cholesterol diet (n = 8). 6 weeks after intervention the animals were sacrificed and morphometry of the vessels was performed. RESULTS: Local administration of ramipril resulted in a non-significant reduction of 17%. The local administration mode was combined with a significant increase in neointima formation. Systemic ramipril administration resulted in a 66% reduction of plaque area. CONCLUSIONS: The benefit of the local ramipril administration was diminished by the inherent vessel trauma. Systemic ramipril administration resulted in a significant reduction of neointimal proliferation in New Zealand white rabbits.

Evidence for peptide synthesis in the course of in vitro proteolysis.

The present paper reports on studies concerned with furnishing evidence for peptide synthesis in the course of in vitro proteolysis. To this end, the oxidized chain B from insulin (INS) (S = 5% in demineralized water) was subjected to tryptic proteolysis (E/S = 1/50; pH 5; 37 degrees C; 24 h). HPLC-as well as amino acid-and sequence analytical studies have shown that the heptapeptide INS 23-29 (Gly-Phe-Phe-Tyr-Thr-Pro-Lys) liberated by way of hydrolysis is linked by tryptic synthesis via transpeptidation or condensation to form a dimer which accounts for 15% of the amount of monomer. The results of the model trials show clearly that during in vitro proteolysis chemical reactions beyond hydrolytic cleavage of peptide bonds take place. In principle, plastein-like reactions (transpeptidation, condensation) can occur during each in vitro proteolysis.

Evaluation of D-amino acid levels in rat by gas chromatography-selected ion monitoring mass spectrometry: no evidence for subacute toxicity of orally fed D-proline and D-aspartic acid.

Sprague-Dawley rats received deionized water (controls) during 28 days or drinking water with added D-proline, L-proline, D-aspartic acid or L-aspartic acid corresponding to a mean daily load of approximately 50 mg amino acid enantiomer kg-1 body weight. Parameters indicating the physiological status (food intake and body weight, glutamic-oxalic-transaminase, glutamic-pyruvic-transaminase, alkaline phosphatase, urea and creatinine in serum, and creatine and osmomolality of urine) were determined. After 28 days the weights of the supposed target organs of toxicity (kidney, liver, brain, thymus) were determined and organs were inspected for macroscopic and microscopic alterations. No pathological changes in the organs were observed and no signs of subacute toxicity (liver, kidney) were found. In serum, homogenates of liver, kidney and brain, and in part, in urine, the amounts of D-amino acids (D-AAs) were quantitatively determined using chiral phase capillary gas chromatography-selected ion monitoring mass spectrometry. Significant levels of certain D-AAs (Ala, Pro, Ser, Asx, Glx, Orn and Lys) were already detectable in kidney and liver homogenates and serum of controls. In brain homogenates the highest amounts among the D-AAs were found for D-Ser (up to 382 nmol g-1), moderate amounts for D-Ala, D-Asx and D-Glx, and, in a few cases, trace amounts for D-Orn and D-Lys (1-2 nmol g-1). D-Pro was not detected either in the brains of controls or in the brains of animals loaded with D-Pro. Feeding with D-Pro resulted in a 20-30 fold increased renal excretion of D-Pro at the end of the experiment. Continuous feeding with D-Asp did not increase renal excretion of this enantiomer, but in the serum, higher amounts (0.8-4.0 mumol-1) were determined in comparison to the control group (0.3-0.9 mumol-1). Feeding with D-Pro led to an increase of this enantiomer in serum (1.3-10.5 mumol-1). Feeding with D-Asp did not increase its amounts in brain homogenates (38 and 43 nmol g-1) in comparison to controls.

[Characterization of pancreatic casein plasteins]. / Charakterisierung pankreatischer Casein-Plasteine.

Characterization of pancreatic casein plasteins. In the course of the plastein reaction hydrophobic peptides concentrate mainly in the aggregates (plasteins), whilst hydrophilic peptides remain in solution (supernatant). Liquid chromatographic and sequence analytical studies of pancreatic casein plasteins have shown that the aggregates consist mainly of the free amino acids tyrosine, phenylalanine and tryptophan. Plasteins contain, in addition, short-chain peptides, particularly from the C-terminal of beta-casein. Characterization of the functional properties of the plasteins has shown clearly that aggregation of the short-chain peptides and free amino acids is brought by non-covalent, hydrophobic and ionogenic interactions. In the supernatants resulting from the plastein reaction caseinophosphopeptide sequences, in particular from alpha s-casein, were determined.

Hexokinase autophosphorylation: identification of a new dual specificity protein kinase.

Hexokinase 1 (HK1) purified from rat brain exhibits protein kinase activity, including autophosphorylation and phosphorylation of other protein substrates. The amino acid specificity of rat brain autophosphorylation was analyzed with monoclonal antibodies directed against phosphotyrosine and by acid hydrolysis of the phosphorylated enzyme. The results show that serine, threonine, and tyrosine residues are phosphorylated after incubation with ATP. The stoichiometry of this phosphorylation was 0.2 mole phosphate per mole hexokinase after 30 min of incubation. Evaluation of freshly isolated HK1 with monoclonal anti-phosphotyrosine antibody indicates that the enzyme is phosphorylated at a basal level in its native state. We concluded that rat brain HK1 is a dual specificity protein kinase that is phosphorylated physiologically.

Studies on the induction and phosphorylation of xanthine dehydrogenase in cultured chick embryo hepatocytes.

Chick embryo hepatocytes, cultured in a chemically defined medium, were used to investigate hormonal requirements for xanthine-dehydrogenase induction and to determine whether the enzyme is phosphorylated. Triiodothyronine is found to be required to induce the synthesis of active enzyme. Inclusion of sodium tungstate in the medium resulted in the complete loss of enzyme activity but no decrease of immunochemically detectable levels of enzyme. Immunoprecipitated xanthine dehydrogenase from cell extracts migrates with enzyme purified from adult chicken liver on SDS/PAGE. Both the native 150-kDa subunit and the 130-kDa form of the enzyme is observed. N-terminal sequence analysis of the 150-kDa subunit shows the following; Ala-Pro-Pro-Glu-Thr-Gly-Asp-Glu-Leu-Val-Phe-Phe-Val-Asn-Gly-Lys-Lys-Val- Val which is similar to the published N-terminal sequences of rat, mouse and insect xanthine dehydrogenases. Autoradiography of denaturing gels of xanthine dehydrogenase isolated from 32P(i)-labeled hepatocytes demonstrates that the 150-kDa and the 130-kDa forms of the enzyme are phosphorylated. Chemical phosphate analysis of acid-precipitated, electrophoretically pure chicken liver xanthine dehydrogenase also shows the presence of covalently bound phosphate. Phosphoamino acid analysis of both 32P-labeled forms of the enzyme demonstrates the presence of phosphoserine. Thus, chicken liver xanthine dehydrogenase contains a phosphoserine residue as found previously in bovine milk xanthine oxidase [Davis, M. D., Edmondson, D. E. & Müller, F. (1984) Eur. J. Biochem. 145, 237-250].

Purification and properties of prostaglandin 9-ketoreductase from pig and human kidney. Identity with human carbonyl reductase.

Prostaglandin 9-ketoreductase (PG-9-KR) was purified from pig kidney to homogeneity, as judged by SDS/PAGE using an improved procedure. The enzyme is pro-S stereoselective with regard to hydrogen transfer from NADPH with prostaglandin E2 as substrate and reduces its 9-keto group with approximately 90% stereoselectivity to form prostaglandin F2 alpha. Approximately 8% of the prostaglandin F formed has the beta-configuration. In addition to catalyzing the interconversion of prostaglandin E2 to F2 alpha, PG-9-KR also oxidizes prostaglandin E2, F2 alpha and D2 to their corresponding, biologically inactive, 15-keto metabolites. Incubation of PG-9-KR with prostaglandin F2 alpha and NAD+ leads to the preferential formation of 15-keto prostaglandin F2 alpha rather than prostaglandin E2. This suggests that the prostaglandin E2/prostaglandin F2 alpha ratio is not determined by the NADP+/NADPH redox couple. The enzyme also reduces various other carbonyl compounds (e.g. 9,10-phenanthrenequinone) with high efficiency. The catalytic properties measured for PG-9-KR suggest that its in vivo function is unlikely to be to catalyze formation of prostaglandin F2 alpha. The monomeric enzyme has a molecular mass of 32 kDa and exists as four isoforms, as judged by isoelectric focusing. PG-9-KR contains 1.9 mol Zn2+/mol enzyme and no other cofactors. Human kidney PG-9-KR was also purified to homogeneity. The human enzyme has a molecular mass of 34 kDa and also exists as four isoforms. Polyclonal antibodies raised against pig kidney PG-9-KR cross-react with human kidney PG-9-KR and also with human brain carbonyl reductase, as demonstrated by Western blot analysis. Sequence data of tryptic peptides from pig kidney PG-9-KR show greater than 90% identity with human placenta carbonyl reductase. From comparison of several properties (catalytical, structural and immunological properties), it is concluded that PG-9-KR and carbonyl reductase are identical enzymes.

Prostaglandin 9-ketoreductase from pig and human kidney: purification, properties and identity with human carbonyl reductase.

Prostaglandin 9-ketoreductase has been purified to apparent homogeneity from pig and human kidney with an overall yield of 6%. The enzyme has a molecular mass of 34 kDa, it is present as an active monomer in diluted solution and contains approx. 2 equivalents Zn++/mole enzyme. It is stereoselective for the pro(S) hydrogen of NADPH and reduces the prostaglandin 9-keto group to yield 90% prostaglandin F2 alpha and 8% of the beta-form. An extensive study of the catalytic properties was carried out, which leads to the conclusion that the enzyme function in vivo is unlikely a catalysis of oxidation/reduction at the prostaglandin 9-position. Five peptides from the pig kidney enzyme were sequenced and compared with the sequence of carbonyl reductase from human placenta. The identity is > 90% and this, together with the immunological cross-reactivity with human brain carbonyl reductase, most strongly suggests that prostaglandin 9-ketoreductase and carbonyl reductase are the same enzyme.