Search PubMed⌕ Search

Biomedical subjects

M Ziegler

Publications and source records attributed to M Ziegler.

At least 73 records · Page 4Linked to original sources
PubMed1999

Effects of sleep and sleep deprivation on catecholamine and interleukin-2 levels in humans: clinical implications.

The objective of this study was to evaluate the effects of nocturnal sleep, partial night sleep deprivation, and sleep stages on catecholamine and interleukin-2 (IL-2) levels in humans. Circulating levels of catecholamines and IL-2 were sampled every 30 min during 2 nights: undisturbed, baseline sleep and partial sleep deprivation-late night (PSD-L; awake from 0300-0600 h) in 17 healthy male volunteers. Sleep was monitored somnopolygraphically. Sleep onset was associated with a significant (P < 0.05) decline of circulating concentrations of norepinephrine and epinephrine, with a nocturnal nadir that occurred 1 h after nocturnal sleep. On the PSD-L night, levels of norepinephrine and epinephrine significantly (P < 0.05) increased in association with nocturnal awakening. During stage 3-4 sleep, levels of norepinephrine, but not epinephrine, were significantly lower (P < 0.05) compared to average levels during the awake period, stages 1-2 sleep, and rapid eye movement sleep. Nocturnal levels of circulating IL-2 did not change with sleep onset or in relation to PSD-L or the various sleep stages. We conclude that sleep onset is associated with changes in levels of circulating catecholamines. Loss of sleep and disordered sleep with decreases in slow wave sleep may serve to elevate nocturnal catecholamine levels and contribute to cardiovascular disease.

Adult↗
PubMed1999

Translocation trisomy dup(21q) and free trisomy 21 can be distinguished by interphase-FISH.

The possibility of distinguishing in routine diagnostics translocation trisomy dup(21q) from disomy 21 as well as from free trisomy 21 using interphase fluorescence in situ hybridization (FISH) with a single copy probe (LSI 21) localized on chromosome 21q22.13-q22.2 is described. In free trisomy 21 and translocation trisomy dup(21q) 94%-98% of the nuclei exhibit 3 specific signals, while in disomy 21 only up to 6% of them have 3 false positive signals. Furthermore, reliable differentiation between free and translocation trisomy dup(21q) can be achieved by evaluating the percentage of nuclei with one single and two co-localized chromosome 21q22.13-q22.2 specific signals in 50-100 interphase nuclei. While in translocation trisomy 75+/-4.3% are co-localized due to a chromosomal rearrangement, in free trisomy 21 only 40+/-2.83% of the nuclei have two co-localized signals by chance. No differences in interphase signal distribution could be detected in two cases with a dicentric chromosome dup(21q) compared to one case with a monocentric one, a comparison not previously carried out. In addition, the single copy probe LSI 21 was compared with the alphoid probe D13Z1/D21Z1 which was found to be unsuitable for such assays due to polymorphisms in the á satellite regions of chromosome 21.

Amniotic Fluid↗
PubMed1999

[Urologic importance of interventional radiology techniques].

In radiology several therapeutical methods were developed and introduced into clinical routine in the last 10 to 15 years. In part these techniques are in competition with established surgical procedures although their main advantage is significantly less invasion. For the urologist diagnostic radiological procedures like selective blood sampling from renal or suprarenal vessels for hormone determination or CT-guided biopsy of retroperitoneal tumors are of special interest as well as procedures with therapeutic aims such as placement of drainage-tubes, percutaneous therapy of varicoceles and arterial endovascular interventions for hemorrhage or vascular wall stenosis. The role of these interventional techniques relevant for urology is described and critically discussed.

Angioplasty, Balloon↗
PubMed1998

Regulation of RNA polymerase II-dependent transcription by poly(ADP-ribosyl)ation of transcription factors.

Poly(ADP-ribosyl) transferase (ADPRT) is a nuclear protein that modifies proteins by forming and attaching to them poly(ADP-ribose) chains. Poly(ADP-ribosyl)ation represents an event of major importance in perturbed cell nuclei and participates in the regulation of fundamental processes including DNA repair and transcription. Although ADPRT serves as a positive cofactor of transcription, initiation of its catalytic activity may cause repression of RNA polymerase II-dependent transcription. It is demonstrated here that ADPRT-dependent silencing of transcription involves ADP-ribosylation of the TATA-binding protein. This modification occurs only if poly(ADP-ribosyl)ation is initiated before TATA-binding protein has bound to DNA and thereby prevents formation of active transcription complexes. Specific DNA binding of other transcription factors including Yin Yang 1, p53, NFkappaB, Sp1, and CREB but not c-Jun or AP-2 is similarly affected. After assembly of transcription complexes initiation of poly(ADP-ribosyl)ation does not influence DNA binding of transcription factors. Accordingly, if bound to DNA, transcription factors are inaccessible to poly(ADP-ribosyl)ation. Thus, poly(ADP-ribosyl)ation prevents binding of transcription factors to DNA, whereas binding to DNA prevents their modification. Considering its ability to detect DNA strand breaks and stimulate DNA repair, it is proposed that ADPRT serves as a molecular switch between transcription and repair of DNA to avoid expression of damaged genes.

ADP Ribose Transferases↗
PubMed1998

Enzymic, cysteine-specific ADP-ribosylation in bovine liver mitochondria.

NAD+ glycohydrolase (NADase) and non-enzymic ADP-ribosylation have been thought to be involved in the regulation of mitochondrial Ca2+ fluxes. In this study it was found that several conditions (5 mM nicotinamide, 5 mM 3-aminobenzamide, 2 mM EDTA, 1 mM ATP, 10 mM dithiothreitol) known to strongly inhibit the NADase decreased ADP-ribosylation in bovine liver mitochondrial membranes with [32P]NAD+ as substrate to only a limited extent, if at all. The reaction led to the specific modification of two proteins with apparent molecular masses of approx. 26 and 53 kDa. An excess of added free ADP-ribose diminished the incorporation of label from [32P]NAD+ only slightly. Dithiothreitol inactivated the NADase, whereas ADP-ribosylation was unaffected. At low concentrations (25 microM) ADP-ribosylation was efficient with NAD+, but not ADP-ribose, as substrate. Under these conditions mitochondrial ADP-ribosylation seems to occur as an enzymic reaction rather than a non-enzymic transfer of ADP-ribose previously liberated from NAD+ by NAD+ glycohydrolase. The chemical stability of the protein-ADP-ribose bonds in the mitochondrial membranes indicated that cysteine residues are the predominant acceptors. Moreover, yeast aldehyde dehydrogenase, known to be a substrate for thiol-associated ADP-ribosylation, was efficiently ADP-ribosylated by using the mitochondrial activity and NAD+ as substrate. The modification of a cysteine residue in the aldehyde dehydrogenase was verified by the observation that pretreatment of this acceptor protein with N-ethylmaleimide substantially decreased its modification. It is therefore concluded that bovine liver mitochondria contain a cysteine-specific ADP-ribosyltransferase.

Adenosine Diphosphate Ribose↗
PubMed1998

A novel function of poly(ADP-ribosyl)ation: silencing of RNA polymerase II-dependent transcription.

Poly(ADP-ribosyl) transferase (ADPRT) is a nuclear enzyme that catalyzes the synthesis of ADP-ribose polymers from NAD+ as well as the transfer of these polymers onto acceptor proteins. The predominant acceptor of the poly(ADP-ribose) chains appears to be the enzyme itself. The function of ADPRT is thought to be related to a number of nuclear processes, including DNA repair and transcription. In this study, it was found that polymerase II-dependent transcription in nuclear HeLa extracts was repressed in the presence of NAD+ at concentrations as low as 1 microM. This repression was strictly dependent on the activity of ADPRT and correlated with the auto(ADP-ribosyl)ation of the enzyme. Subsequent degradation of the ADP-ribose polymers by enzymatic activities present in the nuclear extracts restored transcriptional activity. It would appear from these results that poly(ADP-ribosyl)ation represents the key event of the mechanism underlying NAD(+)-dependent silencing of transcription. Importantly, ADPRT- and NAD(+)-dependent silencing was observed only if poly(ADP-ribosyl)ation had taken place before formation of the transcription complex was completed. That is, if the nuclear extract was preincubated for more than 15 min in the presence of template DNA, transcription was rendered entirely insensitive to NAD+. These results suggest that poly(ADP-ribosyl)ation may prevent polymerase II-dependent transcription, but does not interfere with ongoing transcription. Taking into account the known function of ADPRT, this enzyme may facilitate recovery from DNA damage by stimulating DNA repair and silencing transcription.

Enzyme Activation↗
PubMed1998

Clinical assessment of olfactory dysfunction in Parkinson's disease.

We used two simple tasks to test the capacities of patients with Parkinson's disease to discriminate and identify olfactory stimuli. The patients presented defective odor identification abilities whereas their capacity to discriminate between odors was apparently unaffected. This raises a question about the nature of olfactory dysfunction in Parkinson's disease. Further clinical data is required for analysis of this dysfunction. We therefore propose simple and rapid tests appropriate for clinical use with Parkinson's disease patients.

Adult↗
PubMed1998

[Amputation or reconstruction of IIIB and IIIC open tibial fracture. Decision criteria in the acute phase and late functional outcome].

In IIIB and IIIC type open tibial fractures (according to Gustilo) the primary decision that has to be made regarding therapy is wether or not the limb can be salvaged. To standardize the criteria for amputation different salvage scores have been established in recent years. In this study the Hannover Fracture Scale (HFS), the Predictive Salvage Index (PSI), the Mangled Extremity Severity Score (MESS) and the NISSSA score were evaluated regarding their clinical relevance. When ROC Analysis was performed for all these scores in our patients the HFS revealed the highest sensitivity (0.91), but low specificity (0.71). The highest specificity was noted for the MESS (0.97), which in parallel showed the lowest sensitivity (0.59). In general it seems to be essential to make the right decision initially in order to avoid secondary amputation. All the scores mentioned here appear to be helpful in decision making. Salvaged limbs in IIIB and IIIC fractures presented a comparable good outcome, whereas salvaged IIIC injuries with a high score presented an outcome which was as bad as in secondary amputations. Secondary amputated patients required not only significant longer hospitalization but also resulted in poor outcome compared with the patients having received reconstruction or primary amputation.

Adult↗
PubMed1998

[Diagnosis of non-palpable testis in childhood: laparoscopy or magnetic resonance tomography?].

Laparoscopy and magnetic resonance imaging (MRI) are competetive tools in the diagnostic of non-palpable testis. Advantages and disadvantages of this methods will be demonstrate. 29 boys investigated for this indication with MRI. In case MRI failed to locate the testis laparoscopy was performed with a new miniaturized set of pediatric instruments (1.9 mm optic). The aim of laparoscopy was the identification of the spermatic duct and vessels and their topographic relation to the internal inguinal ring. All findings were verified by open surgical procedures. MRI revealed 10 inguinal and 7 abdominal testis. There was no false positive finding. In 12 boys MRI showed no testis. 4 cases were correct negative, 8 cases were false negative (32%). In these 8 MRI-negative patients laparoscopy revealed 7 inguinal and 1 abdominal testis. The optical quality of the mini-telescope was sufficient for a 100% correct diagnosis. Laparoscopy related complications did not occur. Laparoscopy proved to be a powerful low risk diagnostic method in non-palpable testis with high sensitivity and specifity (100% correct positive, 0% false negative). Therefore lapraroscopy is recommended as primary diagnostic access for this indication. In the same anesthesia a optimal therapy is possible. Nevertheless a positive MRI-finding locates the testis reliably, whereas a negative finding always needs further exploration because testis might have been missed.

Adolescent↗
PubMed1998

Pediatric laparoscopy for nonpalpable testes with new miniaturized instruments.

New miniaturized pediatric telescopes (1.9 or 3.5 mm) and reusable instruments (3.5-mm trocars, scissors, graspers) were used for the first time in a prospective study to evaluate handling safety and efficacy in laparoscopic diagnosis of unilateral nonpalpable testes. The results were confirmed during the same anesthesia by open operation for either orchiopexy or removal of rudimentary spermatic cord structures. Laparoscopy in 13 boys revealed one abdominal testis, 5 vanishing testes, and 7 cases of inguinal retention associated with an open inner inguinal ring. The illumination and detail resolution of the minitelescope were excellent. The 3.5-mm instruments were fully functioning with regard to tissue dissection. No complications occurred. Without technical disadvantages but with increased safety for the patient, the new miniaturized pediatric laparocopic instruments indeed realize a step forward to minimal invasion in infants and children.

Child↗
PubMed1998

Cytokines and adhesion molecules in elective and accidental trauma-related ischemia/reperfusion.

BACKGROUND: The major pathophysiologic role of cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and IL-6, as well as of the (soluble) adhesion molecules ICAM-1 and E-selectin, has been identified using different experimental models of ischemia/reperfusion injury. Moreover, in intensive care management, evaluation of these agents as diagnostic or prognostic tools is of great interest in ischemia/reperfusion injury caused by surgical or accidental trauma. For this reason, inflammatory mediators including those mentioned above were investigated in three different groups of surgical patients. METHODS: The first group (A, n = 13) comprised patients undergoing elective limb surgery without a tourniquet. The second group (B, n = 36) included patients subjected to limb surgery with a tourniquet. The third group (C, n = 30) was composed of accidental trauma patients who were retrospectively divided into those with and without multiple organ dysfunction (+MOD and -MOD, respectively) as defined by the Denver Score. Serial blood samples were taken during a 5-day (elective surgery) or 14-day (accidental trauma) observation period for monitoring of cytokines and soluble adhesion molecules. The clinical course and the degree of MOD were recorded daily. RESULTS: Only when a tourniquet was applied for a mean time of 105 minutes did elective limb surgery result in significantly increased serum levels of IL-6, IL,-1ra, and IL-10 but not TNF-RII. Yet, the increase in cytokine levels was not sufficient to cause an enhanced shedding of adhesion molecules, and both soluble ICAM-1 and soluble E-selectin remained unchanged in groups A and B throughout the 5-day observation period. In patients with multiple injuries (group C), all parameters increased early after trauma up to 10- to 20-fold in comparison with the elective limb surgery patients in groups A and B. When the accidental trauma patients were divided according to the Denver Score for +MOD (n = 8, mean Injury Severity Score = 33.8) and -MOD (n = 22, mean Injury Severity Score = 31.2), a clear difference became evident in serum IL-6 and IL-1ra levels within the first 4 days and in serum IL-10 levels for the first 2 days after trauma, with cytokine levels being significantly higher in the +MOD patients 3 to 4 days before the onset of MOD. Although highly elevated, TNF-RII levels did not differentiate between +MOD and -MOD at any time. The increase in serum cytokine levels was associated with a remarkable expression and shedding of ICAM-1 and E-selectin made obvious by significantly increased soluble serum ICAM-1 levels in +MOD patients compared with the -MOD group between days 3 and 5 after trauma and increased soluble serum E-selectin levels between days 2 and 4 after trauma. CONCLUSION: The release of cytokines and soluble adhesion molecules into the circulation correlates well with the degree of trauma (elective surgery vs. accidental multiple trauma), depending on the extent of the associated ischemia/reperfusion injury. Both groups of mediators are also clearly related to the development of MOD in patients with multiple injuries with generalized ischemia/reperfusion injury caused by hemorrhagic shock. They may be predictive of patients at risk for MOD when measured early in the posttraumatic period.

Adult↗
PubMed1998

Treatment of erectile dysfunction by an external ischiocavernous muscle stimulator.

OBJECTIVE: The aim of the present study was to evaluate the therapeutic potency of an electrotherapy of striated ischiocavernous muscles in patients with erectile dysfunction. PATIENTS AND METHODS: Transcutaneous electrostimulation of striated ischiocavernous muscles by self-adhesive penile or perineal skin electrodes was performed in 48 patients with erectile dysfunction. 6/48 patients (R) responded to intracavernous pharmacotherapy while 42/48 (NR) did not show significant penile rigidity even to intracavernous papaverine/phentolamine/PGE1 triple drug medication. RESULTS: Within the observation time of 3 months, 10/48 patients dropped out. 22/38 patients reported a penile rigidity for sufficient sexual intercourse whereby 3/22 NR required additional intracavernous pharmacotherapy. Penile rigidity could be objectivated by triple drug medicaton in 12/14 NR after ischiocavernous muscle stimulation (EIS) therapy. 5/6 R were treated successfully for premature erection loss. During EIS treatment neither discomfort nor complications could be observed. CONCLUSION: Transcutaneous electrostimulation of ischiocavernous muscles is a new, noninvasive therapy for the improvement of penile rigidity. The clinical results underline the importance of the striated ischiocavernous muscles for penile rigidity.

Adult↗
PubMed1998

A monoclonal antibody-based characterization of autoantibodies against glutamic acid decarboxylase in adults with latent autoimmune diabetes.

Autoantibodies to glutamic acid decarboxylase (GAD) are an important marker of the autoimmune-mediated beta-cell destruction in insulin-dependent (Type I) diabetes. However, these autoantibodies are also found in patients with Stiff-man syndrome (SMS) without onset of diabetes and some diabetic patients who initially present as non-insulin dependent (Type II) diabetes later becoming insulin-dependent, called as latent autoimmune diabetes in adults (LADA). To study the immune response to GAD in these LADA patients a competitive radiobinding assay based on murine monoclonal antibodies recognizing three different GAD regions was performed. The monoclonal antibodies against GAD recognize two different linear epitopes localized at the N- (amino acids 4-17) and C-terminus (amino acids 572-585) and one conformation-dependent epitope region (amino acids 221-442 IDDM-E1) known to be immunodominant for diabetes-associated autoantibodies. All LADA sera (20/20) reduced substantially the 125I-GAD binding of the monoclonal antibodies reactive with the conformation-dependent epitope region IDDM-E1 and only 20% of these sera additionally diminished the 125I-GAD65 binding by those monoclonals reactive with the both linear epitopes. The SMS sera completely abolished the GAD binding of all three monoclonals, reflecting a broader repertoire including an immune response against the IDDM-E1, a conformation-dependent GAD65 epitope region, also revealed if the SMS sera are diluted to equivalent antibody concentrations. In summary, our results show that diabetes-associated GAD autoantibodies even in adult patients with a late autoimmune process preferentially recognize a conformation-dependent middle GAD65 region. An immune response to all three GAD epitope regions is seldom in these LADA patients and only detectable in association with high antibody titres.

Adult↗
PubMed1997

Identification of bovine liver mitochondrial NAD+ glycohydrolase as ADP-ribosyl cyclase.

The present investigation identifies bovine liver mitochondrial NADase (NAD+ glycohydrolase) as a member of the class of bifunctional ADP-ribosyl cyclases/cyclic ADP-ribose hydrolases, known to be potential second messenger enzymes. These enzymes catalyse the synthesis and degradation of cyclic ADP-ribose, a potent intracellular calcium-mobilizing agent. The mitochondrial enzyme utilized the NAD+ analogues nicotinamide guanine dinucleotide (NGD+) and nicotinamide hypoxanthine dinucleotide (NHD+) to form fluorescent cyclic purine nucleoside diphosphoriboses. ADP-ribosyl cyclase activity was also demonstrated using 32P-labelled NAD+ as substrate. The identity of NADase and ADP-ribosyl cyclase was supported by their co-migration in SDS/polyacrylamide gels. Cyclase activity was visualized directly within the gel by detecting the formation of fluorescent cyclic IDP-ribose from NHD+. The enzyme catalysed the hydrolysis of cyclic ADP-ribose to ADP-ribose. Moreover, in the presence of nicotinamide and cyclic ADP-ribose the enzyme synthesized NAD+. Both the ADP-ribosyl cyclase and NADase activities of the enzyme were strongly inhibited by reducing agents. Treatment of the NADase with dithiothreitol caused the apparent inactivation of the enzyme. Subsequent removal of the reducing agent and addition of oxidized glutathione led to a partial recovery of enzymic activity. The results support a model for pro-oxidant-induced calcium release from mitochondria involving cyclic ADP-ribose as a specific messenger, rather than the non-enzymic modification of proteins by ADP-ribose.

ADP-ribosyl Cyclase↗
PubMed1997

Detection and identification of NAD-catabolizing activities in rat tissue homogenates.

NAD may be degraded in several ways. A large number of investigations have shown that at least those catabolic routes which involve the formation of ADP-ribose are related to regulatory processes. In this study a rapid assay was utilized that permits identification of NAD-degrading enzymes directly in sodium dodecylsulfate polyacrylamide gels. Enzymatic activities were recovered by washing the gels in the presence of mild detergents such as lauryl dimethylamine N-oxide or Triton X-100. Subsequent incubation of the gels in the presence of the fluorescent analog 1,N6 etheno-NAD visualized NAD-degrading enzymes. Following excision of the fluorescent bands from the gels, the actual activity of the proteins was established by incubating the gel slices with 14C-labeled NAD and subsequent product analysis by thin layer chromatography (TLC). Homogenates from rat renal cortex and spleen were analyzed by this procedure. While in the spleen homogenate only a single band could be 'activity-stained', in the kidney three bands were detected. Kidney proteins with apparent molecular masses of about 210,000 and 105,000 Da were identified as phosphodiesterase and NAD pyrophosphatase (alkaline phosphodiesterase I), respectively. The third protein exhibited an apparent molecular mass of 41,000. The spleen protein (apparent molecular mass 45,000 Da) cleaved NAD to nicotinamide and ADP-ribose identifying it as NAD glycohydrolase. The procedure is suitable to screen for NAD-converting activities in crude extracts. It is specific for proteins which function as monomers or homo-oligomers.

Adenosine Diphosphate Ribose↗
PubMed1997

Protein-protein interaction of the human poly(ADP-ribosyl)transferase depends on the functional state of the enzyme.

Poly(ADP-ribosyl)transferase (pADPRT) is a nuclear protein which catalyzes the polymerization of ADP-ribose using NAD+ as substrate, as well as the transfer of ADP-ribose polymers to itself and other protein acceptors. The catalytic activity of pADPRT strictly depends on the presence of DNA single-strand breaks. In this report, protein-protein interaction of pADPRT was found to depend on both the extent of automodification with poly(ADP-ribose) and the presence of DNA. Specific binding of radiolabeled pADPRT to transblotted proteins was first tested in blot overlay experiments. For radiolabeling, use was made of the ability of the enzyme to incorporate [32P]ADP-ribose from [32P]NAD+. Varying the concentration of NAD+, two different forms of automodified pADPRT were obtained: oligo(ADP-ribosyl)ated pADPRT with less than 20 ADP-ribose units per chain, and poly(ADP-ribosyl)ated pADPRT with polymer lengths of up to 200 ADP-ribose residues. Interaction of these probes with transblotted HeLa nuclear extracts, purified histones, and distinct regions of recombinant pADPRT was investigated. While the oligo(ADP-ribosyl)ated enzyme associated preferentially with transblotted purified histones, or pADPRT present in HeLa nuclear extracts, poly(ADP-ribosyl)ated pADPRT bound to a variety of transblotted proteins in the nuclear extracts. In the presence of DNA, both the oligo- and the poly(ADP-ribosyl)ated enzymes bound to the transblotted recombinant zinc finger domain of pADPRT even at high salt concentrations. In the absence of DNA, the transblotted automodification domain of pADPRT appeared to be the region involved in self-association. In another set of experiments, unmodified or poly(ADP-ribosyl)ated pADPRT was immobilized on Sepharose. Affinity precipitation of recombinant pADPRT domains confirmed the specific interaction of pADPRT with its zinc finger region and the automodification domain, whereas no interaction was observed with the NAD+ binding domain. Affinity precipitation of HeLa nuclear extracts with poly(ADP-ribosyl)ated pADPRT-Sepharose led to the enrichment of a number of proteins, whereas nuclear proteins bound to the unmodified pADPRT-Sepharose in a smaller extent. The results suggest that protein-protein interaction of the human pADPRT is governed by its functional state.

Adenosine Diphosphate Ribose↗
PubMed1997

Characterization of hydrosoluble and detergent-solubilized forms of mitochondrial NAD+ glycohydrolase from bovine liver.

Treatment of isolated bovine liver mitochondria with either detergents or a crude pancreatic lipase, steapsin, resulted in solubilization of NAD+ glycohydrolase (NADase) activity. The two forms of this enzyme can be visualized directly in SDS-polyacrylamide gels (PAGs) by a fluorescence assay utilizing 1,N6-etheno-NAD+ (epsilon-NAD+) as substrate. Only a slight difference of about 2,000 in the apparent molecular masses was detected. Values of 28,000 and 30,000 for the steapsin- and detergent-solubilized enzyme, respectively, were estimated. The catalytic properties as well as the dependence on temperature, pH, and ionic strength were found to be similar for both forms of the enzyme. One important difference regarding their sensitivity against bivalent metal ions was observed. While the detergent-solubilized NADase was activated in the presence of, for example, Zn++, and inhibited by EDTA, the truncated enzyme seemed to be unaffected under these conditions.

Animals↗