Diltiazem reduces levels of NT-proBNP and improves symptoms compared with metoprolol in patients with permanent atrial fibrillation

AIMS

Short-term treatment with calcium channel blockers lowers levels of N-terminal pro B-type natriuretic peptide (NT-proBNP) and reduces rhythm-related symptoms compared to treatment with beta-blockers. The aim of this study was to compare the longer-term effects of metoprolol and diltiazem for rate control in patients with permanent atrial fibrillation after six months.

METHODS AND RESULTS

Men and women with permanent atrial fibrillation and preserved left ventricular systolic function were randomised to receive either diltiazem 360 mg or metoprolol 100 mg once daily. The primary endpoint was the level of NT-proBNP after a six-month treatment period. Secondary endpoints included heart rate, rhythm-related symptoms and exercise capacity. A total of 93 patients (mean age 71 ±7 years, 28 women) were randomised. After six months' treatment, mean levels of NT-proBNP decreased in the diltiazem group and increased in the metoprolol group, with a significant between-group difference (409.8 pg/mL, 95% CI: 230.6 - 589.1, P<0.001). Treatment with diltiazem significantly reduced rhythm-related symptoms compared to baseline, but no change was observed in the metoprolol group. Diltiazem and metoprolol had similar effects on heart rate and exercise capacity.

CONCLUSION

Diltiazem reduced NT-proBNP levels and improved rhythm-related symptoms. Metoprolol increased peptide levels but had no impact on symptoms despite similar heart rate reduction. Non-dihydropyridine calcium channel blockers should be considered more often for rate control in permanent atrial fibrillation.

Epidemiology and surgical management of 184 obturator hernias: a nationwide registry-based cohort study

PURPOSE

We aimed describe the patient characteristics, surgical details, postoperative outcomes, and prevalence and incidence of obturator hernias. Obturator hernias are rare with high mortality and no consensus on the best surgical approach. Given their rarity, substantial data is lacking, especially related to postoperative outcomes.

METHODS

The study was based on data from the nationwide Danish Hernia Database. All adults who underwent obturator hernia surgery in Denmark during 1998-2023 were included. The primary outcomes were demographic characteristics, surgical details, postoperative outcomes, and the prevalence and incidence of obturator hernias.

RESULTS

We included 184 obturator hernias in 167 patients (88% females) with a median age of 77 years. Emergency surgeries constituted 42% of repairs, and 72% were laparoscopic. Mesh was used in 77% of the repairs, with sutures exclusively used in emergency repairs. Concurrent groin hernias were found in 57% of cases. Emergency surgeries had a 30-day mortality of 14%, readmission rate of 21%, and median length of stay of 6 days. Elective surgeries had a 30-day mortality of 0%, readmission rate of 10%, and median length of stay of 0 days. The prevalence of obturator hernias in hernia surgery was 0.084% (95% CI: 0.071%-0.098%), with an incidence of one per 400,000 inhabitants annually.

CONCLUSIONS

This was the largest cohort study to date on obturator hernias. They were rare, affected primarily elderly women. The method of repair depends on whether the presentation is acute, and emergency repair is associated with higher mortality.

Left ventricular mechanical dispersion by speckle tracking echocardiography is a predictor of atrioventricular block after transcatheter aortic valve implantation

Background

Transcatheter Aortic Valve Implantation (TAVI) is an effective therapy for patients with severe aortic stenosis (AS). Complete atrioventricular block (AVB) that requires permanent pacemaker implantation is a common complication of TAVI. Direct mechanical effect of the prosthetic valve, QRS duration and underlying myocardial fibrosis are proposed mechanisms of AVB after TAVI. Left ventricular mechanical dispersion (LVMD) by Speckle Tracking Echocardiography (STE) is an index of contraction heterogeneity and a marker of myocardial fibrosis.

Purpose

We aimed to evaluate the association between LVMD, QRS duration and AVB to assess markers used to predict AVB after TAVI.

Methods

A total of 163 consecutive TAVI patients were enrolled in the study. Echocardiograms andelectrocardiograms were recorded the day before TAVI procedure to assess global longitudinal strain (GLS), LVMD and QRS duration. AVB and pacemaker (PM) implantation information was obtained by telephone interviews three months after TAVI.

Results

Ten patients were excluded due to poor image quality. Of the 153 patients analyzed, 45% were female. Mean age was 80±7 years. In our patient cohort 15.7% of the patients received PM within three months after TAVI. GLS and QRS duration was not different between AVB group and No-AVB group (−15.8±4.5% vs −16.9±4.4%, p=0.26 and 107±31ms vs 102±18ms, p=0.24 respectively). LVMD was prolonged in patients with subsequent AVB compared to patients with No-AVB (60±19ms vs 48±13ms, p&lt;0.001) (Figure 1). LVMD predicted AVB after TAVI with area under the curve 0.71. LVMD predicted AVB independently of QRS duration (odds ratio 1.68; 95% confidence interval 1.23–2.3; p=0.001 by 10ms increments) (Table 1).

Conclusion

LVMD predicted AVB after TAVI independent of QRS duration. LVMD may be of added value as a myocardial functional echocardiographic predictor of this important and frequent complication of TAVI.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): EACVI Research Grant 2020

No signs of diffuse myocardial fibrosis by T1 mapping in male elite endurance athletes

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): Oslo University Hospital Rikshospitalet, Department of Cardiology, Oslo, Norway.

Background/Introduction: Observational data indicating increased prevalence of focal myocardial fibrosis in endurance athletes have raised concerns regarding the potential detrimental cardiac consequences of long-term athleticism. Cumulative exercise and competitive exposure has been associated with focal myocardial fibrosis visualised as late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. Reports of higher extracellular volume (ECV) in the remote myocardium of athletes with LGE have suggested that this fibrotic process may affect the entire myocardium. However, detailed data on exercise exposure and possible associations with diffuse myocardial fibrosis in endurance athletes are scarce.

Purpose

Our aim was to investigate the association between cumulative exercise exposure and diffuse myocardial fibrosis in male elite endurance athletes.

Methods

In this cross-sectional observational study we evaluated 27 healthy adult male elite endurance athletes age 41 ± 9 years and 16 healthy controls age 41 ± 12 years. All subjects underwent 3 T CMR including LGE and T1 mapping. The athletes detailed their exercise history from 12 years of age in a structured interview.

Results

Athletes had lower resting heart rate, enlarged cardiac chambers and increased left ventricular mass compared to controls, in accordance with the athlete’s heart phenotype (table 1). In contrast to what would have been expected in diffuse myocardial fibrosis, athletes had shorter native T1 time than controls (1214 ± 24 vs. 1268 ± 48 ms, p &lt; 0.001). The native T1 time fell with increasing yearly exercise dose, accumulated exercise duration and accumulated exercise dose (r=-0.46, -0.51 and -0.53, p &lt; 0.05 for all). In a stepwise multiple linear regression model, only the accumulated exercise dose was independently associated with native T1 time as shown in figure 1 (r = 0.53, p = 0.01). There was no clear difference in ECV between athletes and controls (22.5 ± 3.1 vs. 23.8 ± 2.0 %, p = 0.16), indicating that increased left ventricular mass in the athletes was balanced without disproportionate extracellular expansion. There was no association between exercise exposure and ECV. LGE was observed in 5 (19 %) of the athletes and none of the controls (p = 0.14). There was no difference in native T1 time (1220 ± 4 vs. 1212 ± 27 ms, p = 0.56) or ECV (22.0 ± 1.2 vs. 22.7 ± 3.4 %, p = 0.69) between athletes with or without LGE.

Conclusion(s): We did not observe signs of diffuse myocardial fibrosis in healthy elite endurance athletes. These results indicate that diffuse myocardial fibrosis is not highly prevalent in healthy athletes with extreme exercise exposure. Abstract Figure.  Abstract Figure.

Lower reoperation rates after open and laparoscopic groin hernia repair when performed by high-volume surgeons: a nationwide register-based study

PURPOSE

Previous studies have shown a correlation between surgeons with high annual volume and better outcomes after various surgical procedures. However, the preexisting literature regarding groin hernia repair and annual surgeon volume is limited. The aim was to investigate how annual surgeon volume affected the reoperation rates for recurrence after primary groin hernia repair.

METHODS

This nationwide cohort study was based on data from the Danish Hernia Database and the Danish Patient Safety Authority's Online Register. Patients ≥ 18 years undergoing laparoscopic or Lichtenstein primary groin hernia repair between November 2011 and January 2020 were included. Annual surgeon volume was divided into five categories: ≤ 10, 11-25, 26-50, 51-100, and > 100 cases/year.

RESULTS

We included 25,262 groin hernia repairs performed in 23,088 patients. The risk of reoperation for recurrence after Lichtenstein repair was significantly higher for the volume categories of ≤ 10 (HR 4.02), 11-25 (HR 3.64), 26-50 (HR 3.93), or 51-100 (HR 4.30), compared with the > 100 category. The risk of reoperation for recurrence after laparoscopic repair was significantly increased for the volume categories of ≤ 10 (HR 1.89), 11-25 (HR 2.08), 26-50 (HR 1.80), and 51-100 (HR 1.58) compared with the > 100 category.

CONCLUSION

The risk of reoperation for recurrence was significantly higher after Lichtenstein and laparoscopic repairs performed by surgeons with < 100 cases/year compared with > 100 cases/year. This indicates that higher surgeon volume minimizes the risk of reoperation for recurrence after groin hernia repair.

Mortality and Urological Complications After Open Groin Hernia Repair in Local, General, and Regional Anesthesia: A Nationwide Linked Register Study

BACKGROUND AND AIMS

The choice of anesthesia method may influence mortality and postoperative urological complications after open groin hernia repair. We aimed to investigate the association between type of anesthesia and incidence of urinary retention, urethral stricture, prostate surgery, and 1-year mortality after open groin hernia repair.

MATERIALS AND METHODS

Data were linked from the Danish Hernia Database, the national patient register, and the register of causes of death. We investigated data on male adult patients receiving open groin hernia repair from 1999 to 2013 with either local anesthesia, regional anesthesia, or general anesthesia. In relation to the type of anesthesia, we compared mortality and urological complications up to 1 year postoperatively. We adjusted for covariates in a logistic regression assessing urological complications and with the Cox regression assessing mortality.

RESULTS

We included 113,069 open groin hernia repairs in local anesthesia, regional anesthesia, or general anesthesia. The risk of urinary retention adjusted for covariates was higher after both general anesthesia (adjusted odds ratio = 1.64, 95% confidence interval = 1.05-2.57, p = 0.031) and regional anesthesia (odds ratio = 2.99, 95% confidence interval = 1.67-5.34, p < 0.0005) compared with local anesthesia. The adjusted risk of prostate surgery was also higher for both general anesthesia (odds ratio = 1.58, 95% confidence interval = 1.23-2.03, p < 0.0005) and regional anesthesia (odds ratio = 1.90, 95% confidence interval = 1.40-2.58, p < 0.0005) compared with local anesthesia. Type of anesthesia did not influence 1-year mortality or the risk for urethral stricture.

CONCLUSION

Patients undergoing open groin hernia repair in local anesthesia experience the lowest rate of urological complications and have equally low mortality compared with patients undergoing repair in general anesthesia or regional anesthesia.

Network meta-analysis of urinary retention and mortality after Lichtenstein repair of inguinal hernia under local, regional or general anaesthesia

BACKGROUND

Urinary retention and mortality after open repair of inguinal hernia may depend on the type of anaesthesia. The aim of this study was to investigate possible differences in urinary retention and mortality in adults after Lichtenstein repair under different types of anaesthesia.

METHODS

Systematic searches were conducted in the Cochrane, PubMed and Embase databases, with the last search on 1 August 2018. Eligible studies included adult patients having elective unilateral inguinal hernia repair by the Lichtenstein technique under local, regional or general anaesthesia. Outcomes were urinary retention and mortality, which were compared between the three types of anaesthesia using meta-analyses and a network meta-analysis.

RESULTS

In total, 53 studies covering 11 683 patients were included. Crude rates of urinary retention were 0·1 (95 per cent c.i. 0 to 0·2) per cent for local anaesthesia, 8·6 (6·6 to 10·5) per cent for regional anaesthesia and 1·4 (0·6 to 2·2) per cent for general anaesthesia. No death related to the type of anaesthesia was reported. The network meta-analysis showed a higher risk of urinary retention after both regional (odds ratio (OR) 15·73, 95 per cent c.i. 5·85 to 42·32; P < 0·001) and general (OR 4·07, 1·07 to 15·48; P = 0·040) anaesthesia compared with local anaesthesia, and a higher risk after regional compared with general anaesthesia (OR 3·87, 1·10 to 13·60; P = 0·035). Meta-analyses showed a higher risk of urinary retention after regional compared with local anaesthesia (P < 0·001), but no difference between general and local anaesthesia (P = 0·08).

CONCLUSION

Local or general anaesthesia had significantly lower risks of urinary retention than regional anaesthesia. Differences in mortality could not be assessed as there were no deaths after elective Lichtenstein repair. Registration number: CRD42018087115 ( https://www.crd.york.ac.uk/prospero).

Dealing with the round ligament of uterus in laparoscopic groin hernia repair: a nationwide survey among experienced surgeons

PURPOSE

Our aim was to investigate how often a national cohort of experienced groin hernia surgeons transected the round ligament of uterus in laparoscopic groin hernia repair. Furthermore, we wished to explore the surgeons' personal opinions and knowledge on the function and importance of the ligament.

METHODS

An electronic questionnaire was sent to all surgeons in Denmark performing laparoscopic groin hernia repair on a regular basis. The questionnaire consisted of demographic details, estimated incidence of transection of the round ligament of uterus, information about transection to the patients, documentation of transection in the medical records, and the surgeons' personal opinions and knowledge of the importance of the ligament.

RESULTS

A total of 71 surgeons met our eligibility criteria and 61 (86%) provided complete responses. We estimated that the round ligament of uterus was transected in 395 of 813 (49%) herniorrhaphies during the past 12 months. Personal opinions and knowledge on the function of the ligament and the importance of preserving it varied greatly among the surgeons.

CONCLUSIONS

Transection of the round ligament of uterus in laparoscopic groin hernia repair is common. The consequences of transecting the round ligament of uterus are not well described, and opinions and knowledge on the issue vary widely among experienced hernia surgeons.

Systematic review and network meta-analysis of methods of mesh fixation during laparoscopic ventral hernia repair

BACKGROUND

Ventral hernia repairs are common and have high recurrence rates. They are usually repaired laparoscopically with an intraperitoneal mesh, which can be fixed in various ways. The aim was to evaluate the recurrence rates for the different fixation techniques.

METHODS

This systematic review included studies with human adults with a ventral hernia repaired with an intraperitoneal onlay mesh. The outcome was recurrence at least 6 months after operation. Cohort studies with 50 or more participants and all RCTs were included. PubMed, Embase and the Cochrane Library were searched on 22 September 2016. RCTs were assessed with the Cochrane risk-of-bias assessment tool and cohort studies with the Newcastle-Ottawa scale. Studies comparing fixation techniques were included in a network meta-analysis, which allowed comparison of more than two fixation techniques.

RESULTS

Fifty-one studies with a total of 6553 participants were included. The overall crude recurrence rates with the various fixation techniques were: absorbable tacks, 17·5 per cent (2 treatment groups); absorbable tacks with sutures, 0·7 per cent (3); permanent tacks, 7·7 per cent (20); permanent tacks with sutures, 6·0 per cent (25); and sutures, 1·5 per cent (6). Six studies were included in a network meta-analysis, which favoured fixation with sutures. Although statistical significance was not achieved, there was a 93 per cent chance of sutures being better than one of the other methods.

CONCLUSION

Both crude recurrence rates and the network meta-analysis favoured fixation with sutures during laparoscopic ventral hernia repair.

The initial experience of introducing the Onstep technique for inguinal hernia repair in a general surgical department

Background and Aims:

A new technique for the repair of inguinal hernia, called Onstep, has been described. This technique places the mesh in the preperitoneal space medially and between the internal and external oblique muscles laterally. The Onstep technique has not yet been described outside the inventors’ departments. This study was based on the first 80 patients operated by the Onstep technique in a general surgical department. The objective of the study was to investigate postoperative pain and complications following the Onstep repair of inguinal hernia.

Material and Methods:

A total of 80 patients, operated in our department, were followed up in the medical files and contacted by letter. Patients were asked to fill out the Inguinal Pain Questionnaire, Carolinas Comfort Scale, and the Activity Assessment Scale, in order to assess postoperative pain.

Results:

No perioperative complications occurred. The response rate was 85% on the mailed questionnaires. No patients had any activities they were not able to perform. Activity Assessment Scale results: 80.3% did not have substantial pain-related impairment of daily function. Carolinas Comfort Scale results: 94.8% did not have a symptomatic repair. Inguinal Pain Questionnaire results: 95.5% reported no pain or pain that was easily ignored.

Conclusions:

It seems from this study that the Onstep technique is a safe method for inguinal hernia repair regarding perioperative and postoperative complications. The postoperative pain seems to be equal to or lower than after the Lichtenstein technique.

Aerococcus urinae: polyphasic characterization of the species

A polyphasic characterization of Aerococcus urinae is presented. In this study the intraspecies relationships between 26 strains of varying geographical origin were examined by phenotypic tests, ribotyping and multilocus enzyme electrophoresis. The results demonstrated two main phenotypic patterns that could be distinguished in tests for hydrolysis of aesculin, and acid production from amygdalin and salicin. Strains were either negative (n=19) or positive (n=6) in these tests. One strain had a deviating pattern. Heterogeneity within the 19 pattern I strains was demonstrated especially by phenotypic tests (acid production from ribose, mannitol, sorbitol, sucrose and D-arabitol) and by multilocus enzyme electrophoresis. However, DNA sequence analysis of the 16S rRNA (n=7) and gyrB genes (n=3) from strains representing the two main patterns showed no variation in sequences among strains. Comparison of A. urinae and representatives of related taxa by 16S rDNA sequence analysis showed that the taxon is related to, but distinct from, other Aerococcus spp.

Demonstration by PCR and DNA sequencing of Corynebacterium pseudodiphtheriticum as a cause of joint infection and isolation of the same organism from a surface swab specimen from the patient

A case of infectious arthritis following arthroscopy is described. Real-time PCR, using universal bacterial primers targeting the 16S rRNA gene, and subsequent DNA sequencing of the PCR product demonstrated the presence of DNA from Corynebacterium pseudodiphtheriticum in the synovial fluid from the affected knee. Culture from a surface swab from the site of purulent discharge from the knee was initially reported as growing normal skin microbiota. Knowing the result of the DNA analysis, the specimen was re-examined and a diphtheroid bacterium was isolated. The DNA sequence of the isolated bacterium was identical to that of the DNA in the joint. The isolated bacterium was tested for susceptibility to relevant antibiotics. Demonstration and identification of bacterial DNA by PCR and gene sequencing may not by itself give information on important characteristics such as susceptibility to antibiotics of the infecting bacterium. The present case illustrates that the results obtained by the method can be used to isolate the relevant bacterium in culture from other sites and thereby characterize it. It furthermore demonstrates that C. pseudodiphtheriticum can cause severe arthritis when inoculated into joints.

Spatial distribution of competing ions around DNA in solution

The competition of monovalent and divalent cations for proximity to negatively charged DNA is of biological importance and can provide strong constraints for theoretical treatments of polyelectrolytes. Resonant x-ray scattering experiments have allowed us to monitor the number and distribution of each cation in a mixed ion cloud around DNA. These measurements provide experimental evidence to support a general theoretical prediction: the normalized distribution of each ion around polyelectrolytes remains constant when ions are mixed at different ratios. In addition, the amplitudes of the scattering signals throughout the competition provide a measurement of the surface concentration parameter that predicts the competition behavior of these cations. The data suggest that ion size needs to be taken into account in applying Poisson-Boltzmann treatments to polyelectrolytes such as DNA.

Molecular characterization of a Leishmania donovanii cDNA clone with similarity to human 20S proteasome a-type subunit

Using plasma from patients infected or previously infected with Leishmania donovanii, we isolated a L. donovanii cDNA clone with similarity to the proteasome a-type subunit from humans and other eukaryotes. The cDNA clone, designated LePa, was DNA sequenced and Northern blot analysis of L. donovanii poly(A(+))mRNA indicated the isolation of a full length cDNA clone with a transcript size of 1.9 kb. The expressed recombinant LePa fusion protein induced proliferation of peripheral blood mononuclear cells in one out of seven patients who had suffered from visceral leishmaniasis. Plasma from 16 out of 25 patients with visceral leishmaniasis and four out of 18 patients with cutaneous leishmaniasis contained IgG antibodies which reacted with the purified LePa fusion protein as evaluated in an ELISA. The LePa DNA sequence was inserted into an eukaryotic expression vector and Balb/c mice were vaccinated. DNA vaccination of Balb/c mice with LePa generated an initial significant reduction in lesion size after challenge.

Diagnosis of visceral leishmaniasis by the polymerase chain reaction using blood, bone marrow and lymph node samples from patients from the Sudan

We have evaluated the sensitivity of the polymerase chain reaction (PCR) as a diagnostic tool for Leishmania donovani using blood, bone marrow and lymph node samples from Sudanese patients with a confirmed infection. Forty patients were diagnosed by microscopic examination of bone marrow or lymph node samples. The PCR was able to detect parasite DNA in 37 out of 40 blood samples. In bone marrow and lymph node samples, the PCR was able to detect parasite DNA in all 7 and 6 samples, respectively. We suggest that the PCR should be considered as a valuable and sensitive tool for the diagnosis of L. donovani infection. However, if PCR diagnosis is to supplement or even replace microscopic diagnosis in developing countries, a large number of patients with no apparent signs of infection and patients with other diseases have to be tested in order to evaluate its true potential.

Noise-free normalized fringe patterns and local pixel transforms for strain extraction

Noise reduction is one of the most exciting problems in automatic fringe processing. We propose a two-dimensional (2-D) envelope transform for normalization of fringe patterns, coupled with spin filtering, to construct so-called noise-free normalized fringe patterns. The 2-D envelope transform uses correct fringe intensity envelopes for normalization of fringe patterns, i.e., for making the fringe background and amplitude constant over the whole field. Spin filtering is applied to fringe patterns for removal of random noise taking into account fringe flow. With spin filtering and the 2-D envelope transform, a noise-free normalized fringe pattern is constructed for postprocessing. Based on this improved fringe pattern, two local pixel transforms for strain extraction from a single moiré pattern are developed, in which the digital pure secondary moiré method is improved and the strain-field image method with division is developed.

Evaluation of the polymerase chain reaction in the diagnosis of cutaneous leishmaniasis due to Leishmania major: a comparison with direct microscopy of smears and sections from lesions

We have compared the sensitivity of the polymerase chain reaction (PCR) as a diagnostic tool against conventional microscopical diagnostic techniques in patients with cutaneous leishmaniasis from the Sudan. Twenty-eight patients were diagnosed according to clinical criteria followed by microscopical examination of histological sections and slit or impression smears. The PCR had a sensitivity of 86% when used alone, and 93% when combined with Southern blotting. In contrast, microscopy of histological sections had a sensitivity of 76% and slit and impression smears of only 55% and 48%, respectively. The PCR should be considered as a valuable and sensitive diagnostic tool in the diagnosis of cutaneous leishmaniasis; it has the added advantage of identification of the species of Leishmania causing the lesion.

Fringe-orientation maps and fringe skeleton extraction by the two-dimensional derivative-sign binary-fringe method

The fringe-orientation information of an interferometric fringe pattern is provided in the form of a fringe-orientation map by spin filtering. The fringe-orientation information is an important feature of fringe patterns and is helpful in many fringe-pattern processing algorithms. With the help of a fringe-orientation map the two-dimensional derivative-sign binary-fringe method is developed to extract fringe skeletons from a fringe pattern with an arbitrary fringe distribution. This fringe skeleton extraction method does not require thresholds and a thinning process. It is relatively robust and highly accurate.

New spin filters for interferometric fringe patterns and grating patterns

The basic spin filter for interferometric fringe patterns is improved and developed into several new versions for different applications. These spin filters can filter off random noise efficiently and have almost no blurring effect and phase distortion for the fringe patterns. First, they find the local fringe tangent direction, and then they apply a one-dimensional low-pass filter on this direction. In this way the spin filters can separate easily and clearly high-frequency noise from a real fringe signal with nearly zero frequency. The new spin filters are suitable not only for various fringe patterns but also for wrapped-phase, line-grating, and cross-grating patterns, which are impossible by common filters.

Digital pure shear-strain moiré patterns

A method of constructing digital shear-strain moiré patterns with pure shear-strain fringes is proposed here with the help of digital image processing techniques and moiré carrier patterns of rotation. This method is developed from a digital pure secondary moiré pattern method. The pure shear-strain moiré patterns do not require a high fringe density of primary moiré patterns. It can give the shear-strain values at every point over the whole field and give the visible distribution of the shear-strain field.

Characterization of cDNA clones encoding a novel calcium-activated neutral proteinase from Schistosoma mansoni

To identify and characterize Schistosoma mansoni proteins that are recognized by infected hosts, we have used a pool of sera from infected humans to screen cDNA libraries constructed from poly(A)+ mRNA of adult S. mansoni. The deduced amino acid sequences of the three isolated clones showed a high degree of similarity to the large subunit of calcium-activated neutral proteinase (CANP) from humans and chicken. These overlapping clones, which include a nearly full-length clone with an open reading frame of 758 amino acid residues, together encode the entire large subunit of CANP. The deduced sequence of this S. mansoni protein can be divided into four domains (I-IV) that include the two domains characteristic of other large subunits of CANP: a thiol-protease domain (II) and a calcium-binding domain (IV) containing EF hand motifs. However, the schistosome protein is unique in having only three EF hand motifs in the calcium-binding domain and in having an additional EF hand motif that is shared between domains II and III. We have shown that these EF hand motifs are capable of binding 45Ca2+. Furthermore, the large subunit is S. mansoni contains an NH2-terminal sequence of 28 residues that is absent from the mammalian CANPs and has a high degree of similarity to the presumed receptor binding sequence of colicin Ia and Ib.

Echinostoma caproni in mice: shedding of antigens from the surface of an intestinal trematode

The surface antigens, which induce a serum antibody response during infection of mice with the intestinal trematode Echinostoma caproni, were examined. It was demonstrated that antigens are shed from the surface of juvenile and 4-week old adult E. caproni during in vitro culture. SDS-PAGE and Western blot analysis of in vitro shed and detergent solubilized surface antigens indicated that the four major antigens released from the surface of adult parasites had molecular masses of approximately 26,000, 66,000, 75,000 and 88,000. A modified ELISA technique showed the in vitro turn-over rate of the surface antigens to be very high, with a half-life of 8-15 min in both juvenile and adult E. caproni trematodes. Transmission electron microscopy of the surface of adult parasites revealed a highly active secreting tegument which was densely packed with membrane-bound vesicles, reflecting the high rate of shedding of the surface antigens. An attempt to immunize mice with detergent solubilized adult surface antigens failed to induce resistance to infection with metacercariae of E. caproni.

Displacement and strain calculations by the phase shift method

The phase shift method, well known in holographic interferometry, is applied to the deformation of line gratings. The method uses the moire effect but it determines local displacement or strain from the grey values of three shifted images instead of the coordinates of the fringes. The basic equations are derived from the transmittance function. The theoretical error with respect to a given displacement field is calculated by simulation. Real errors are investigated by related plotter-generated line gratings. The phase shift method is especially suitable for automatic digital image processing.