Retrospective evaluation of surgical technique, complications and long-term outcome of lateral and medial humeral condylar fractures in 80 dogs.

CASE HISTORY: Medical records from a single veterinary teaching hospital in Giessen, Germany were retrospectively reviewed for dogs presenting with medial or lateral humeral condylar fractures (HCF) between 2007 and 2019. Data regarding surgical technique and complications were collected from the medical records. These were supplemented through information obtained from telephone interviews with referral veterinarians and from an owner questionnaire completed ≥12 months after surgical repair, which also provided data regarding the outcome. CLINICAL FINDINGS: Eighty dogs with 85 HCF were identified: 13 (15.3%) HCF were medial (bilateral in two dogs) and 72 (84.7%) were lateral (bilateral in three dogs). French Bulldogs (n = 19/80; 23.8%) were most commonly affected. Patients were predominantly skeletally immature and light-weight, with a median age at the time of presentation of 3 (min 2, max 118) months and with a median body weight of 6.4 (min 1, max 46) kg. There were 38 female (47.5%) and 42 male (52.5%) dogs. Fractures developed most frequently secondary to minor trauma (67/77; 87.0%). Dogs were presented in 35/84 (41.7%) cases more than 24 hours after fracture occurrence. TREATMENT AND OUTCOME: Surgical treatment was performed in 80/85 (94.1%) HCF. An open reduction and internal fixation approach was chosen in all cases. A transcondylar screw (TS) combined with a supracondylar (SC) K-wire (67/80; 83.8%) was the most frequently used fixation technique. Considering all fracture fixation methods, complications (26/80; 32.5%) were classed as minor in 10 (12.5%), major in 14 (17.5%) and catastrophic in two (2.5%) of the 80 surgically treated HCF. Long-term outcome was excellent in 68.6% (24/35 HCF) and very good in 22.9% (8/35 HCF) of the cases for which follow-up information was obtained. Additionally, owner information revealed that 85.7% of dogs (30/35 HCF) were free of lameness in the long-term. CLINICAL RELEVANCE: This case series demonstrates that surgical repair of lateral and medial HCF with a TS and SC K-wire is a viable option to consider in skeletally immature and light-weight patients. Complications occur frequently after surgical fixation of HCF, but owners can expect a very good to excellent long-term outcome in the majority of cases.

Repeat ablation for paroxysmal atrial fibrillation - Does adenosine play a role in predicting pulmonary vein reconnection patterns?

BACKGROUND: Pulmonary vein (PV) reconduction after PV isolation (PVI) unmasked by adenosine is associated with a higher risk for paroxysmal atrial fibrillation (PAF) recurrence. It is unknown if the reconnected PVs after adenosine testing and immediate re-ablation can predict reconnection and reconnection patterns of PVs at repeat procedures. We assessed reconnection of PVs with and without dormant-conduction (DC) during the first and the repeat procedure. METHODS: We included 67 patients undergoing PVI for PAF and a second procedure for PAF recurrence. DC during adenosine administration at first procedure was seen in 31 patients (46%). 264 PVs were tested with adenosine; DC was found in 48 PVs (18%) and re-ablated during first procedure. During the second procedure, all PVs where checked for reconnection. RESULTS: Fifty-eight patients (87%) showed PV reconnection during the second procedure. Reconnection was found in 152/264 PVs (58%). Of 216 PVs without reconnection during adenosine testing at the first ablation, 116 PVs (53.7%) showed reconnection at the repeat procedure. Overall, 14.9% of patients showed the same PV reconnection pattern in the first and second procedure, expected statistical probability of encountering the same reconnection pattern was only 6.6%(p = 0.012). CONCLUSIONS: In repeat procedures PVs showed significantly more often the same reconnection pattern as during first procedure than statistically expected. More than 50% of initial isolated PVs without reconnection during adenosine testing showed a reconnection during repeat ablation. Techniques to detect susceptibility for PV re-connection like prolonged waiting-period should be applied. Elimination of DC should be expanded from segmental to circumferential re-isolation or vaster RF application.

Are biters sick? Health status of tail biters in comparison to control pigs.

BACKGROUND: Tail biting is a multifactorial problem. As the health status is one of the factors commonly linked to tail biting, this study focuses on the health of identified biters. 30 (obsessive) biters are compared to 30 control animals by clinical and pathological examination as well as blood and cerebrospinal fluid samples. In that way, altogether 174 variables are compared between the groups. Moreover, connections between the variables are analysed. RESULTS: In the clinical examination, 6 biters, but only 2 controls (P = 0.019) were noticeably agitated in the evaluation of general behaviour, while 8 controls were noticeably calmer (2 biters, P = 0.02). Biters had a lower body weight (P = 0.0007) and 13 biters had overlong bristles (4 controls, P = 0.008). In the pathological examination, 5 biters, but none of the controls had a hyperceratosis or inflammation of the pars proventricularis of the stomach (P = 0.018). However, 7 controls and only 3 biters were affected by gut inflammation (P = 0.03). In the blood sample, protein and albumin levels were below normal range for biters (protein: 51.6 g/l, albumin: 25.4 g/l), but not for controls (protein: 53.7 g/l, albumin: 27.4 g/l), (protein: P = 0.05, albumin: P = 0.02). Moreover, 14 biters, but only 8 controls had poikilocytosis (P = 0.05). Although not statistically different between groups, many animals (36/60) were affected by hypoproteinemia and hyponatremia as well as by hypokalemia (53/60) and almost all animals (58/60) had hypomagnesemia. For hypomagnesemia, significant connections with variables linked to tail damage and ear necrosis were detected (rs/V/ρ ≥ 0.4, P ≤ 0.05). CONCLUSION: The results suggest that behavioural tests might be helpful in identifying biters. Moreover, cornification and inflammation of the pars proventricularis is linked to becoming a biter. Furthermore, the results highlight the need for appropriate and adjusted nutrient and mineral supply, especially with regard to magnesium.

Systemic serum amyloid A in early (<24 h) diagnosis of acute synovial structure involvement in horses with penetrating limb injuries.

Synovial structure involvement secondary to limb injury is a common emergency in equine practice, requiring an accurate initial diagnosis for immediate treatment. This study aimed to investigate the clinical usefulness of Serum amyloid A (SAA) in the initial diagnosis of synovial structure involvement caused by acute (<24 h) penetrating limb injuries in horses and to correlate SAA with standard diagnostic parameters. Fifty-five horses with acute limb injuries were divided into two groups: Group 1 (G1, n = 26) with a diagnosis of penetrating synovial trauma and Group 2 (G2, n = 29) without synovial structure penetration. Serum SAA, white blood cell (WBC) count and fibrinogen as well as clinical criteria and synovial fluid parameters were assessed on admission. The two groups were compared using a two-sample t-test (metric parameters) or a Wilcoxon-Mann-Whitney test (ordinal parameters). Correlation was determined between serum SAA and the following parameters: WBC count, fibrinogen, synovial total nucleated cell count (TNCC) and percentage of neutrophils (% N), body temperature and the degree of lameness. Serum SAA concentrations were not different between G1 and G2; however, there were statistically significant differences in general health, the degree of lameness, and synovial fluid parameters. In G1, serum SAA concentrations positively correlated with fibrinogen concentrations and synovial fluid % N. Nonetheless, SAA cannot be used as a sole tool to diagnose synovial structure involvement caused by limb injuries. Synovial fluid parameters remain the most important tool in the diagnosis of synovial penetration. In cases where synoviocentesis fails or is not possible, serum SAA might support diagnosis.

Social network analysis in pigs: impacts of significant dyads on general network and centrality parameters.

In general, one animal is considered dominant over another animal if it has won more fights than its opponent. Whether this difference in won and lost fights is significant is neglected in most studies. Thus, the present study evaluates the impact of two different calculation methods for dyadic interactions with a significant asymmetric outcome on the results of social network analysis regarding agonistic interactions of pigs in three different mixing events (weaned piglets, fattening pigs and gilts). Directly after mixing, all animals were video recorded for 17 (fattening pigs, gilts) and 28 h (weaned piglets), documenting agonistic interactions. Two calculation methods for significant dyads, that is, dyadic interactions with a clear dominant subordinate relationship in which one animal has won significantly more fights than its encounter, were proposed: pen individual limits were calculated by a sign test considering the differences of won and lost fights of all dyadic interactions in each pen; dyad individual limits were determined by a one-sided sign test for each individual dyad. For all data sets (ALL, including all dyadic interactions; PEN or DYAD, including only significant dyads according to pen or dyad individual limits), networks were built based on the information of initiator and receiver with the pigs as nodes and the edges between them illustrating attacks. General network parameters describing the whole network structure and centrality parameters describing the position of each animal in the network were calculated. Both pen and dyad individual limits revealed only a small percentage of significant dyads for weaned piglets (12.4% or 8.8%), fattening pigs (4.2% or 0.6%) and gilts (3.6% or 0.4%). The comparison between the data sets revealed only high Spearman's rank correlation coefficients (rS) for the density, that is, percentage of possible edges that were actually present in the network, whereas the centrality parameters showed only moderate rS values (0.37 to 0.75). Thus, the rank order of the animals changed due to the exclusion of insignificant dyads, which shows that the results obtained from social network analysis are clearly influenced if insignificant dyads are excluded from the analyses. Due to the fact that the pen individual limits consider the overall level of agonistic interactions within each pen, this calculation method should be preferred over the dyad individual limits. Otherwise, too many animals in the group became isolated nodes with zero centrality for which no statement about their position within the network can be made.

Tail and ear postures of growing pigs in two different housing conditions.

This study analyses tail and ear postures of growing pigs in two different housing systems throughout the growing period. On one farm, 168 undocked pigs (84: barren housing, 84: enriched housing) were observed individually at three time periods: beginning, middle and end of the growing period. By scan sampling, the tail (curled-up, raised, hanging, tucked under, wagging) and ear posture (forwards, sidewards, backwards, mixed) was noted. Scans were performed hourly during the activity periods by direct observation. Moreover, the body posture (standing, feeding, lying (eyes open), lying (eyes closed) and tail lesions were noted. Data were analysed using the GLIMMIX procedure in SAS. Results revealed significant differences between the enriched and barren group especially for curled-up tails, tucked under tails and ears directed forwards. More curled-up tails and ears directed forwards occurred in the enriched and more tucked under tails in the barren habitat. The time period of observation also had significant influences. Tail lesions had significant effects on most tail postures. Most ear postures were influenced by the body posture of the pigs. Overall, this study contributes to the understanding of body language, specifically tail and ear postures in pigs.

An Easy and Fast Protocol for Affinity Bead-Based Protein Enrichment and Storage of Proteome Samples.

Analysis of dilute protein samples is a challenging task for scientific and industrial labs all over the world. Although there are different methods available that allow for protein enrichment from various biological sources, all of them have serious limitations apart from their advantages. In order to perform highly reproducible and sensitive protein analysis of lowest concentrated samples, we optimized a method to enrich proteins on affinity beads (StrataClean) recently. This chapter describes the general protocol of this strategy, thereby discussing the power as well as the limits of this technique for qualitative and quantitative proteomic studies. Moreover, additional application and protocol variants will be discussed, expanding the number of compatible up- and downstream processing techniques compared to the originally published method. Hence, we evaluated the reduction of time for sample preparation by use of preprimed affinity beads and shorter incubation durations as well as the influence of high concentration of salts or urea in the sample buffer.

Epidemic Spreading in an Animal Trade Network - Comparison of Distance-Based and Network-Based Control Measures.

This study considered a simple SIR model for the spread of epidemics amongst holdings of a producer community in Northern Germany, based on the directed network of animal movements. The aim of this study was to evaluate the efficiency of different control measures to reduce the epidemic size substantially. The currently applied control measures based on the distance to an infected holding were compared with the control measures based on the specific network-based centrality parameters. We found that network-based measures led to a more efficient control of epidemics with a much smaller number of removed holdings. To assess the impact of different holding types, the analysed control measures were implemented by both including and excluding these holding types. The comparison revealed a crucial role of multipliers in the spread of an epidemic. The network-based control measures depending on the removal by out-degree, outgoing infection chain, betweenness centrality and outgoing closeness centrality showed the best results: In the three-year network, on average, 2.75, 4.15, 3.73 and 3.43 times more holdings had to be removed by the control measures based on the 1, 3, 5 and 10 km radius to reduce the epidemic to the same size compared with the network-based control measures. In an area with a higher holding density, the improvement of the network-based control measures may become even more obvious. The removal of holdings based on the above-mentioned centrality parameters did thus not only rapidly decompose the network into fragments, but also reduced the epidemic size most efficiently.

Interobserver reliability of the 'Welfare Quality(®) Animal Welfare Assessment Protocol for Growing Pigs'.

The present paper focuses on evaluating the interobserver reliability of the 'Welfare Quality(®) Animal Welfare Assessment Protocol for Growing Pigs'. The protocol for growing pigs mainly consists of a Qualitative Behaviour Assessment (QBA), direct behaviour observations (BO) carried out by instantaneous scan sampling and checks for different individual parameters (IP), e.g. presence of tail biting, wounds and bursitis. Three trained observers collected the data by performing 29 combined assessments, which were done at the same time and on the same animals; but they were carried out completely independent of each other. The findings were compared by the calculation of Spearman Rank Correlation Coefficients (RS), Intraclass Correlation Coefficients (ICC), Smallest Detectable Changes (SDC) and Limits of Agreements (LoA). There was no agreement found concerning the adjectives belonging to the QBA (e.g. active: RS: 0.50, ICC: 0.30, SDC: 0.38, LoA: -0.05 to 0.45; fearful: RS: 0.06, ICC: 0.0, SDC: 0.26, LoA: -0.20 to 0.30). In contrast, the BO showed good agreement (e.g. social behaviour: RS: 0.45, ICC: 0.50, SDC: 0.09, LoA: -0.09 to 0.03 use of enrichment material: RS: 0.75, ICC: 0.68, SDC: 0.06, LoA: -0.03 to 0.03). Overall, observers agreed well in the IP, e.g. tail biting (RS: 0.52, ICC: 0.88; SDC: 0.05, LoA: -0.01 to 0.02) and wounds (RS: 0.43, ICC: 0.59, SDC: 0.10, LoA: -0.09 to 0.10). The parameter bursitis showed great differences (RS: 0.10, ICC: 0.0, SDC: 0.35, LoA: -0.37 to 0.40), which can be explained by difficulties in the assessment when the animals moved around quickly or their legs were soiled. In conclusion, the interobserver reliability was good in the BO and most IP, but not for the parameter bursitis and the QBA.

The amphipathic helix concept: length effects on ideally amphipathic LiKj(i=2j) peptides to acquire optimal hemolytic activity.

In a minimalist approach to modeling lytic toxins, amphipathic peptides of LiKj with i=2j composition and whose length varies from 5 to 22 residues were studied for their ability to induce hemolysis and lipid vesicle leakage. Their sequences were designed to generate ideally amphipathic alpha helices with a single K residue per putative turn. All the peptides were lytic, their activities varying by more than a factor of 103 from the shortest 5-residue-long peptide (5-mer) to the longest 22-mer. However, there was no monotonous increase versus length. The 15-mer was as active as the 22-mer and even more than melittin which is used as standard. Partition coefficients from the buffer to the membrane increased in relation to length up to 12 residues, then weakly decreased to reach a plateau, while they were expected to increase monotonously with peptide length and hydrophobicity as revealed from HPLC retention times. Fluorescence labeling by a dansyl group at the N-terminus, or by a W near the CO-terminus, show that up to 12 residues, the peptides were essentially monomeric while longer peptides strongly aggregated in the solution. Lipid affinity was then controlled by peptide length and was found to be limited by folding and self-association in buffer. The lytic activity resulted both from lipid affinity, which varied by a factor of 20-fold, and from efficiency in disturbing the membrane when bound, the latter steeply and monotonously increasing with length. The 15-residue-long peptide, KLLKLLLKLLLKLLK, had the optimal size for highest lytic activity. The shallow location of the fluorescent labels in the lipids is further evidence for a model of peptides remaining flat at the interface.

Vascular extracellular superoxide dismutase activity in patients with coronary artery disease: relation to endothelium-dependent vasodilation.

BACKGROUND: Increased inactivation of nitric oxide by oxygen free radicals contributes to endothelial dysfunction in patients with coronary artery disease (CAD). We therefore determined the activity of extracellular superoxide dismutase (EC-SOD), the major antioxidant enzyme system of the vessel wall, and its relation to flow-dependent, endothelium-mediated dilation (FDD) in patients with CAD. METHODS AND RESULTS: SOD isoenzyme activity was determined in coronary arteries from 10 patients with CAD and 10 control subjects. In addition, endothelium-bound EC-SOD activity (eEC-SOD), released by heparin bolus injection, and FDD of the radial artery were measured in 35 patients with CAD and 15 control subjects. FDD, determined by high-resolution ultrasound, was assessed at baseline, after intra-arterial infusion of vitamin C, N-monomethyl-L-arginine, and combination of both. EC-SOD activity in coronary arteries (control subjects: 126+/-14; CAD: 63+/-11 U/mg protein; P<0.01) and eEC-SOD activity in vivo (control subjects: 14.5+/-1.1; CAD: 3.8+/-1.1 U. mL(-1). min(-1); P<0.01) were reduced in patients with CAD. Activity of eEC-SOD was positively correlated with FDD (r=0.47; P<0. 01) and negatively with the effect of the antioxidant vitamin C on FDD (r=-0.59; P<0.01). In young individuals with hypercholesterolemia, however, eEC-SOD activity was increased (21. 0+/-1.2 U. mL(-1). min(-1); n=10; P<0.05). CONCLUSIONS: In patients with CAD, vascular EC-SOD activity is substantially reduced. The close relation between endothelium-bound EC-SOD activity and FDD suggests that reduced EC-SOD activity contributes to endothelial dysfunction in patients with CAD. In young hypercholesterolemic individuals, however, endothelium-bound EC-SOD activity is increased and may, in part, counteract impairment of endothelial function as the result of increased formation of oxygen free radicals.

Characterization of contact structures for the spread of infectious diseases in a pork supply chain in northern Germany by dynamic network analysis of yearly and monthly networks.

A major risk factor in the spread of diseases between holdings is the transport of live animals. This study analysed the animal movements of the pork supply chain of a producer group in Northern Germany. The parameters in-degree and out-degree, ingoing and outgoing infection chain, betweenness and ingoing and outgoing closeness were measured using dynamic network analysis to identify holdings with central positions in the network and to characterize the overall network topology. The potential maximum epidemic size was also estimated. All parameters were calculated for three time periods: the 3-yearly network, the yearly and the monthly networks. The yearly and the monthly networks were more fragmented than the 3-yearly network. On average, one-third of the holdings were isolated in the yearly networks and almost three quarters in the monthly networks. This represented an immense reduction in the number of holdings participating in the trade of the monthly networks. The overall network topology showed right-skewed distributions for all calculated centrality parameters indicating that network resilience was high concerning the random removal of holdings. However, for a targeted removal of holdings according to their centrality, a rapid fragmentation of the trade network could be expected. Furthermore, to capture the real importance of holdings for disease transmission, indirect trade contacts (infection chain) should be considered. In contrast to the parameters regarding direct trade contacts (degree), the infection chain parameter did not underestimate the potential risk of disease transmission. This became more obvious, the longer the observed time period was. For all three time periods, the results for the estimation of the potential maximum epidemic size illustrated that the outgoing infection chain should be chosen. It considers the chronological order and the directed nature of the contacts and has no restrictions such as the strongly connected components of a cyclic network.

The amphipathic alpha-helix concept. Application to the de novo design of ideally amphipathic Leu, Lys peptides with hemolytic activity higher than that of melittin.

An original series of 12- to 22-residue-long peptides was developed, they are only constituted by apolar Leu and charged Lys residues periodically located in the sequence in order to general ideal highly amphipathic alpha-helices. By circular dichroism, the peptides are proven to be mainly alpha-helical in organic and aqueous solvents and in the presence of lipids. The peptides are highly hemolytic, their activity varies according to the peptide length. The 15-, 20-, and 22-residue-long-peptides have LD50 approximately 5 x 10(-8) M for 10(7) erythrocytes, i.e. they are 5-10 times more active than melittin, and are indeed several orders of magnitude more active than magainin or mastoparan.

Steam sterilization: a suitable alternative?

Extracorporeal blood-circuit devices can be sterilized by ethylene oxide (EtO), irradiation, or steam. The majority of these devices are sterilized by the first two processes, and the use of steam sterilization seems to be limited. This article compares the different processes, discusses their advantages and disadvantages, and makes a case for sterilizing these products by steam.

[Inpatient rehabilitation measures in the early phase following surgery of intervertebral disk displacement as an effective alternative to ambulatory after-care]. / Stationäre Rehabilitationsmassnahmen in der Frühphase nach Bandscheibenoperation als wirksame Alternative zur ambulanten Nachsorge.

Between 1983 and 1986, a total of 1012 patients were treated in our rehabilitation clinic after intervertebral disc surgery, either admitted shortly post op, or at a later time. Males outweighed females in proportion by 56 vs. 44%; the average age at surgery was 44 yrs. for male, and 42 yrs for female patients. 966 patients (95%) had undergone lumbar surgery, 46 (5%) surgery in the cervical region; 12% of the patients were operated twice and 2% for a third time. Except for those admitted shortly post-surgery, an average period of 6 to 7 months elapsed between the family doctor's, or specialist's, application for a rehabilitation measure and admission to the rehabilitation clinic. Average duration of incapacity for work totalled 6.2 months (males 5.6 months, females 6.8 months). Of the 228 patients with "incapable for work" status on admission to the clinic, 160 were discharged home capable for work, another 34 were recommended for work trial. The remaining 34 patients were referred back to the acute clinics for further diagnosis, or renewed surgery. The advantages of in-patient rehabilitation measures, among them post-surgery postural etc. training ("back training"), are set out, along with ways how the rehabilitative procedures should be dovetailed with the course of management.

Detection of a 2 mu derivative yeast plasmid with altered properties.

The Saccharomyces cerevisiae (Sacch. cerevisiae) strain RXII, like many others, harbours plasmid DNAs. and one category of them is homologous to the 2 mu plasmid of yeast. DNA-DNA hybridization experiments indicated altered structures of this species as regards the number and distribution of the restriction sites. The efforts made to clone either the whole plasmid in pBR328 or its fragments in pBR322 vectors remained unsuccessful, since deleted plasmids were isolated without insert DNA, and even the loss of vector sequences was observed. The data suggest, that the 2 mu derivative plasmid in strain RXII represent an unique category of this extrachromosomal genetic element.

[Determination of free L-triiodothyronine (FT3) in serum. Comparative tests of 2 FT3 radioimmunoassays]. / Die Bestimmung des freien L-Trijodthyronins (FT3) im Serum. Ein Testvergleich zweier FT3-Radioimmunoassays.

A trial of the routine use of two test procedures for the evaluation of free L-triiodothyronine (FT3) was carried out (1070 patients). The normal values given by the manufacturers are not correct with respect to our patient group. In order to avoid false hyperthyroid (FT3-Amerlex) or false hypothyroid (FT3-DPC) values, the normal spectrum was redetermined for each. Under these conditions, both tests could show a definite difference between normal and overfunctioning of the thyroid. In substitution therapy with L-thyroxine, the quality of adjustment may be assessed according to the FT3 value. An extension of the normal spectrum, as for FT4, is not necessary. Since any additional assessment of the carrier protein concentration becomes irrelevant, the FT3 test is advisable also for economic reasons.

BCG immunostimulation in primary pulmonary cancer (a clinical, immunological and radiological study).

The authors reported the results of a clinical, radiological and immunological study of 147 primary pulmonary cancer cases who were immunostimulated with BCG vaccine over a period of three years between 01.01.76 and 31.12.78. Compared with the same number and stage of cancerous patients treated with the same cytostatic drugs and/or surgically without BCG immunostimulation, the survival rate of the immunostimulated group was higher than that of the control group. The radiological picture did not change during the study time in 45% of the patients, regression was observed in 34%, and progression in 21% in the Stage I vaccinated group, while in the control Stage I group regression was only noticed in 21%, and progression was observed in 50%. In the Stage II vaccinated group regression was noted in 48%, in the control group in 23%. No favourable changes were noted in Stage III groups, neither in the vaccinated nor in the nonvaccinated cases. The more favourable prognosis of the immunostimulated group was reflected in the results of the skin tests and in the cellular and humoral immunological responses too. The modification of the BCG immunostimulated pulmonary cancer patients gives a statistically significant prolongation of survival time and a beneficial improvement of life quality and expectation.

Evaluation of peptide-peptide interactions using reversed-phase high-performance liquid chromatography.

The separation of peptides during RP-HPLC depends mainly upon differential hydrophobic interactions of the individual peptides being separated with the C18 group of the stationary phase. We have examined the behavior of dimeric disulfide-linked model peptides during RP-HPLC in order to study self-induced conformational effects. A set of 18 analogues of the amphipathic alpha-helical sequence Ac-LKLLKKLLKKLKKLLKKL-NH2 was used for this study. These analogues differed only by the successive replacement of each position with a cysteine. Strong peptide-peptide interactions, occurring through interchain hydrophobic forces, resulted in a presenting face to the C18 group, consisting primarily of lysine residues and, in turn, in early retention times. Three homo-dimers were also found to be strongly alpha-helical in water as determined by circular dichroism spectroscopy.

Dual channel imaging of two-dimensional electropherograms in Bacillus subtilis.

The allocation of proteins to stimulons and regulons is an essential step towards the understanding of the global regulation of the expression of entire genomes. The computer-aided evaluation and matching of two-dimensional protein gels loaded with radioactively labeled proteins from exponentially growing or stressed cells is a useful but time-consuming procedure for the description of stimulons and regulons. This paper describes the dual-channel image analysis that offers the opportunity to visualize the content and synthesis rate of a whole set of bacterial proteins on a single electropherogram. By pulse-labeling with L-[35S]methionine, the protein synthesis pattern (red color) can be directly compared with the protein level pattern (green color). Because matching of other gels can be avoided, this new technique is useful for the rapid search for proteins that belong to different stimulons or regulons. This approach was tested for the identification of proteins of heat stress or oxidative stress stimulons. Proteins that were induced by heat or oxidative stress colored red while proteins whose synthesis was switched off by the stress factor colored green. Proteins that were continuously synthesized before and after the imposition of stress retained their yellow color. The advantages and possible pitfalls of the technique are discussed.