Intrasac pressure changes and vascular remodeling after endovascular repair of abdominal aortic aneurysms: review and biomechanical model simulation.

In this paper, we review existing clinical research data on post-endovascular repair (EVAR) intrasac pressure and relation with abdominal aortic aneurysm (AAA) size changes. Based on the review, we hypothesize that intrasac pressure has a significant impact on post-EVAR AAA size changes, and post-EVAR remodeling depends also on how the pressure has changed over a period of time. The previously developed model of an AAA based on a constrained mixture approach is extended to include vascular adaptation after EVAR using an idealized geometry. Computational simulation shows that the same mechanism of collagen stress-mediated remodeling in AAA expansion induces the aneurysm wall to shrink in a reduced sac-pressure after post-EVAR. Computational simulation suggests that the intrasac pressure of 60 mm Hg is a critical value. At this value, the AAA remains stable, while values above cause the AAA to expand and values below cause the AAA to shrink. There are, however, variations between individuals due to different cellular sensitivities in stress-mediated adaptation. Computer simulation also indicates that an initial decrease in intrasac pressure helps the AAA shrink even if the pressure increases after some time. The presented study suggests that biomechanics has a major effect on initial adaptation after EVAR and also illustrates the utility of a computational model of vascular growth and remodeling in predicting diameter changes during the progression and after the treatment of AAAs.

The development of rapid real-time PCR detection system for Vibrio parahaemolyticus in raw oyster.

AIMS: To develop a new rapid real-time polymerase chain reaction (PCR) based detection system for Vibrio parahaemolyticus (V. parahaemolyticus) applicable to raw oyster samples. METHODS AND RESULTS: V. parahaemolyticus cells were artificially inoculated to oysters. Samples were homogenized in 100 ml of sterile saline water and serially diluted to 1.5 CFU ml(-1) level. One millilitre of diluents was centrifuged and the pellet was resuspended with 100 microl of de-ionized water. DNA was extracted by boiling for 20 min, and 0.5 microl was used as a template for PCR reaction. Real-time PCR was performed with TMC-1000 system (1 microl PCR system). The detection system was found to achieve detection limit of 1.5 CFU g(-1) for V. parahaemolyticus. Furthermore, the specificities of these assay systems were confirmed with more than 20 bacterial strains, including various Vibrio species. CONCLUSIONS: Rapid and sensitive food-borne pathogen detection techniques for V. parahaemolyticus is important to the food industry and consumers. The direct detection of V. parahaemolyticus from food is possible with micro real-time PCR system. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that oyster samples can be tested for V. parahaemolyticus with a rapid, specific and simple procedure.

[New techniques for surgical treatment of postoperative male stress incontinence]. / Neue Verfahren zur operativen Therapie der postoperativen Belastungsinkontinenz beim Mann.

The impact of minimally invasive techniques for the treatment of postoperative male incontinence has significantly improved in recent years. These techniques are based on the continuous increase in urethral resistance. This resistance can be readjusted with balloons placed paraurethrally or with readjustable suburethral slings. The success rates depend on the preoperative degree of incontinence. With bulking agents that are transurethrally injected into the submucosa of the sphincter, continence rates between 12 and 90% can be seen. Severe complications are rare. The impact of the studies is often limited due to a short follow-up. After implantation of adjustable balloons that are placed paraurethrally close to the bladder neck, continence rates up to 70% can be seen. The overall improvement of incontinence is observed in up to 90% of the treated patients. Complications such as balloon migration or mechanical disorders can cause operative revision. Suburethral sling systems are available as bone-anchored slings or as readjustable slings. Continence can be seen in up to 90% of the patients postoperatively. Severe complications such as sling erosion or sling infection are rare. In cases of mild and moderate incontinence, these minimally invasive techniques are good alternatives to the fascial sling or alloplastic sphincter implantation. To improve the evaluation and to compare these techniques with the conventional methods, further investigations with a longer follow-up are necessary.

[The role of perineal ultrasound compared to lateral cysturethrogram in urogynecological evaluations]. / Die Perinealsonographie im Vergleich zum lateralen Zysturethrogramm bei der Inkontinenzdiagnostik der Frau.

PURPOSE: The aim of this study was to evaluate prospectively whether perineal ultrasound is comparable to the lateral cysturethrogram in the evaluation of incontinent women. PATIENTS AND METHODS: Following urodynamic investigations, a lateral cysturethrogram and perineal ultrasound (5 MHz probe, bladder filling 300 mL) were performed in 98 incontinent women. In women with detrusor overactivity and consecutively reduced bladder capacity, ultrasound was performed at maximum capacity. To evaluate differences between perineal ultrasound and the cysturethrogram, the difference between bladder neck and lower border of symphysis and the retrovesicle angle beta were determined at rest and during the Valsalva manoeuvre. RESULTS: Using perineal ultrasound, the differences between bladder neck and symphysis could be determined at rest and during the Valsalva manoeuvre in all patients. The determination of the retrovesical angle beta was possible in all patients at rest and in 89 of the 98 women during the Valsalva manoeuvre. The lateral cysturethrogram enabled the determination of difference between bladder neck and symphysis and the retrovesicle angle beta at rest in 81 of 98 women. During the Valsalva manoeuvre, the difference between bladder neck and symphysis and retrovesicle angle beta could be determined in 72 of the 98 women. In the 26 remaining women, the determination was impossible due to severe adiposity or cystoceles of the second or third degree. CONCLUSIONS: Perineal ultrasound provides comparable data to the lateral cysturethrogram. In patients with adiposity, perineal ultrasound seems to be superior. Within the routine evaluation of women suffering from incontinence, the lateral cysturethrogram can be replaced by perineal ultrasound without any limitations of the diagnostic value.

Hans Christian Jacobaeus: Inventor of human laparoscopy and thoracoscopy.

Hans Christian Jacobaeus performed the first clinical laparoscopic surgery in Stockholm. This pioneering procedure was based on the animal experiments of Georg Kelling (1866-1945), a German physician from Dresden, who performed the first laparoscopic intervention in 1901 using a Nitz cystoscope in a dog. In 1910, Jacobaeus published his initial experiences with laparoscopic surgery in the Münchner Medizinischen Wochenschrift under the title "The Possibilities for Performing Cystoscopy in Examinations of Serous Cavities." He used this technique for diagnostic purposes in undefined abdominal complaints and functional impairment. Jacobaeus was the first who pointed out the possibility of injuring organs, especially the intestines, by inserting the trocar. In 1910, Jacobaeus recognized the immense diagnostic and therapeutic possibilities of laparoscopic surgery, as well as its difficulties and limits. He also was the first to realize the need for initial endoscopic training in animals and corpses. He promoted the development of special laparoscopic instruments to optimize and simplify the procedure.

Proteolytic modification of raw-starch-digesting amylase from Bacillus circulans F-2 with subtilisin: separation of the substrate-hydrolytic domain and the raw substrate-adsorbable domain.

Raw starch-digesting amylase (BF-2A, 93,000 Da) from Bacillus circulans F-2 was converted into two components during digestion with subtilisin. The two components were separated and designated BF-2A' (63 kDa) and BF-2B (30 kDa), respectively. BF-2A' exhibited the same hydrolysis curve for soluble starch as the original amylase (BF-2A). Moreover, the catalytic activities of original and modified enzymes were indistinguishable in Km, Vmax and in their specific activity for soluble starch hydrolysis. However, its absorbability and digestibility on raw starch was greatly decreased. Furthermore, the enzymatic action pattern on soluble starch was differed greatly from that of BF-2A. The stability of the enzymes decreased below pH 5.5 and at 50 degrees C, while it was quite stable even at pH 12. On the other hand, the smaller peptide (BF-2B) could be adsorbed onto raw starch. From these results, it is suggested that the larger peptide (BF-2A') has a region responsible for the expression of the enzyme activity to hydrolyze soluble substrate, and the smaller peptide (BF-2B) plays a role on raw starch adsorption and also contributes to the original enzyme-to-enzyme stabilization. A proposed model of the raw-starch-digesting enzyme from this strain is extensively discussed.

Determination of the positions of the disulfide bonds in aqualysin I (a thermophilic alkaline serine protease) of Thermus aquaticus YT-1.

Aqualysin I is a heat-stable alkaline serine protease produced by Thermus aquaticus YT-1. Aqualysin I comprises 281 amino acid residues and contains four cysteine residues. The cysteine residues seemed to form disulfide bonds in the molecule. Thus, the positions of the disulfide bonds were investigated. Disulfide bond-containing peptides were identified by peptide mapping with HPLC before and after carboxymethylation of chymotryptic peptides of aqualysin I. The disulfide bond-containing peptides were isolated and then carboxymethylated. Carboxymethylcysteine-containing peptides were purified, and their amino acid compositions and sequences were determined. Based on the data obtained and the primary structure of aqualysin I, it was concluded that two disulfide bonds were formed between Cys67 and Cys99, and between Cys163 and Cys194.

Isolation and transformation of uracil auxotrophs of the edible basidiomycete Pleurotus ostreatus.

Uracil auxotrophs of Pleurotus ostreatus were isolated using the selectable marker, resistance to 5'-fluoro-orotic acid (5'-FOA). Two of the nine uracil auxotrophs obtained were transformed to prototrophy using plasmid pTRura 3-2 that contains the orotidine monophosphate decarboxylase (ura3) gene from Trichoderma reesei. Southern blot analyses of the transformants showed that the transforming DNA had integrated into the genome of the protoplasts. Using 2 x 10(7) protoplasts, this system gave a transformation efficiency of about 30 transformants per microg of DNA. Normal fruiting bodies were induced in the transformants by crossing them with wild-type monokaryons, and the basidiospores collected from these fruiting bodies showed a biased segregation rate to prototrophy. These results indicate the integrated DNA was stably inherited.

Nucleotide sequence of the gene for alkaline phosphatase of Thermus caldophilus GK24 and characteristics of the deduced primary structure of the enzyme.

The gene encoding Thermus caldophilus GK24 (Tca) alkaline phosphatase was cloned into Escherichia coli. The primary structure of Tca alkaline phosphatase was deduced from its nucleotide sequence. The Tca alkaline phosphatase precursor, including the signal peptide sequence, was comprised of 501 amino acid residues. Its molecular mass was determined to be 54¿ omitted¿760 Da. On the alignment of the amino acid sequence, Tca alkaline phosphatase showed sequence homology with the microbial alkaline phosphatases, 20% identity with E. coli alkaline phosphatase and 22% Bacillus subtilis (Bsu) alkaline phosphatases. High sequence identity was observed in the regions containing the Ser-102 residue of the active site, the zinc and magnesium binding sites of E. coli alkaline phosphatase. Comparison of Tca alkaline phosphatase and E. coli alkaline phosphatase structures suggests that the reduced activity of the Tca alkaline phosphatase, in the presence of zinc, is directly involved in some of the different metal binding sites. Heat-stable Tca alkaline phosphatase activity was detected in E. coli YK537, harboring pJRAP.

Purification and properties of Aquifex aeolicus DNA polymerase expressed in Escherichia coli.

The gene encoding Aquifex aeolicus (Aae) DNA polymerase was expressed under the control of the trp promoter on a high-copy plasmid, pTRPNS, in Escherichia coli. The expressed enzyme was purified 11-fold with a 13.8% yield and a specific activity of 2268.3 U mg(-1). The optimum pH of the enzyme was 6.8-7.2. The optimal concentrations of KCl and Mg(2+) were 20-30 mM and 4-5 mM, respectively. Aae DNA polymerase contained a double-strand-dependent 3'-->5' proofreading exonuclease activity but lacked any detectable 5'-->3' exonuclease activity.

Cloning, nucleotide sequence, and expression of the DNA ligase-encoding gene from Thermus filiformis.

The gene encoding Thermus filiformis (Tfi) DNA ligase was cloned and its nucleotide sequence was determined by the chain-termination method. The primary structure of Tfi DNA ligase was deduced from its nucleotide sequence. The Tfi DNA ligase comprises of 667 amino acid residues and its molecular mass was determined to be 75,936 Da. The deduced amino acid sequence of Tfi DNA ligase showed a 86.5% homology to Tth DNA ligase and 43.5% to E. coli DNA ligase. The Lys-116 of Lys-Val-Asp-Gly motif was proposed to be the active residue of Tfi DNA ligase. In comparison with the amino acid composition of DNA ligase, Tfi DNA ligase showed a significant increase in the proportion of charged residues, Arg and Glu, compared to E. coli DNA ligase. The G + C content in the first, second, and third positions of the codons used were 70.3%, 40.3%, and 90.3%, respectively. Codon usage in Tfi DNA ligase was heavily biased towards the use of G + C in the third position. Under tac promoter control, Tfi DNA ligase was overproduced to greater than 9% of E. coli BL26Blue cellular proteins.

Cloning and analysis of the DNA polymerase-encoding gene from Thermus filiformis.

The gene encoding Thermus filiformis (Tfi) DNA polymerase was cloned and its nucleotide sequence was determined. The primary structure of Tfi DNA polymerase was deduced from its nucleotide sequence. Tfi DNA polymerase is comprised of 833 amino acid residues and its molecular mass was determined to be 93,890 Da. The deduced amino acid sequence of Tfi DNA polymerase showed a high sequence homology to E. coli DNA polymerase I-like DNA polymerases: 78.5% homology to Taq DNA polymerase, 78.4% to Tca DNA polymerase, and 41.8% to E. coli DNA polymerase I. An extremely high sequence identity was observed in the region containing polymerase activity. The G + C content of the coding region for the Tfi DNA polymerase gene was 68.5%, which was higher than that of the chromosomal DNA (65%). The G + C contents in the first, second, and third positions of the codons used were 71.8%, 40.9%, and 92.7% respectively. Codon usage in Tfi DNA polymerase was heavily biased towards the use of G + C in the third position. Rare codons with U or A as the third base were sometimes used to avoid using GA(A/T) TC and TCGA sequences, as they are recognition sites for the restriction endonucleases TfiI and TaqI.

Cloning and analysis of the DNA polymerase-encoding gene from Thermus caldophilus GK24.

The gene encoding Thermus caldophilus GK24 (Tca) DNA polymerase was cloned into Escherichia coli using the structural gene coding for Thermus aquaticus YT-1 (Taq) DNA polymerase as a hybridization probe. The nucleotide sequence of the cloned DNA was determined. The primary structure of the Tca DNA polymerase was deduced from the nucleotide sequence. The Tca DNA polymerase comprised 834 amino acid residues and its molecular mass was determined to be 93,810. On alignment of the whole amino acid sequence, Tca DNA polymerase showed a high sequence homology with the E. coli DNA polymerase I-like DNA polymerases, and 86% identity with Taq DNA polymerase, 38% with E. coli and Streptococcus pneumoniae (Spn) DNA polymerase I. An extremely high sequence identity was observed in the region containing the polymerase activity. The codon usage in the Tca DNA polymerase gene was in fact similar to the characteristic usages in the genes for proteins from bacteria of genus Thermus: the G+C content in the third position of the codons was as high as 93%. The Tca DNA polymerase gene was expressed under the control of tac promoter on a high copy plasmid, pTCA in E. coli.

Top DNA polymerase from Thermus thermophilus HB27: gene cloning, sequence determination, and physicochemical properties.

A gene, top encoding Thermus thermophilus HB27 (Top) DNA polymerase, was cloned in E. coli and its nucleotide sequence was determined. Based on its deduced amino acid sequence, Top DNA polymerase is a 93.8 kDa protein comprising 834 amino acid residues. Top DNA polymerase showed high amino acid homology with those of other DNA polymerases from the Thermus sp., for example, 87.3% identity with Taq DNA polymerase. Codon usage in the top gene was similar to those of the proteins from other Thermus strains. The G + C content in the third position of the codons was as high as 93%. The top gene under the control of the tac promoter was expressed in E. coli [plasmid pTOP9]. DNA amplification using the recombinant Top DNA polymerase performed the same as other thermostable DNA polymerases from Thermus strains. The optimum temperature for its reaction was 76 degrees C. An interesting observation was that the recombinant Top DNA polymerase was slowly cleaved into two fragments of about 60 kDa and 35 kDa at 4 degrees C and -20 degrees C. The larger fragment possessed polymerase activity like the Klenow fragment of E. coli DNA polymerase I. To prevent the cleavage of the Top DNA polymerase, a variety of protecting agents were examined. Among those examined, (NH4)2SO4 (100 mM) solution demonstrated an outstanding ability to block its cleavage for a prolonged period.

Production of fructo-oligosaccharides from molasses by Aureobasidium pullulans cells.

Three different strains of Aureobasidium pullulans were grown in batch cultures to compare their abilities for the production of fructo-oligosaccharides. Specific intracellular enzyme activity was the highest with strain KCCM 12017 and enzyme production was closely coupled to growth. Using A. pullulans cells, 166 g/l fructo-oligosaccharides was produced from 360 g/l molasses sugar as sucrose equivalent at 55 degrees C and pH 5.5 after 24 h incubation.

Spine needle biopsy simulator using visual and force feedback.

OBJECTIVE: Biopsy with an inserted needle is an important procedure for lesion detection in the spine, but is difficult to perform due to the presence of many critical organs near the spine. This article presents a spine needle biopsy simulator, based on visual and force feedback, which can be used to plan the optimal path of a needle and to practice the procedure without risk. MATERIALS AND METHODS: The simulator is composed of a 3D human model, a visual-feedback component, a force-feedback component, and an evaluation module. The human model is based on 3D CT data. The visual-feedback component provides an oblique section, multiplanar reformatting images, and a volume-rendered image. Of these, the oblique section display is very useful for planning a 3D path for the needle. During simulation, the force-feedback component generates and provides realistic forces acting on the biopsy needle in real time by synchronizing them to visual feedback. After each simulation, the evaluation module provides a performance analysis for the trainee. RESULTS: For an XCT abdomen volume data set of 256 x 256 x 256, the update rate of image rendering due to needle movement is over 25 Hz, with a force-feedback rate of 1 kHz. This performance proved to be good enough for the trainee to learn the relationship between visual and force feedback. CONCLUSIONS: The simulator is useful for the planning of and training in complicated 3D spine needle biopsy procedures. It may be used as an educational tool for beginners, a practice tool to increase expertise, or a test bed for new procedures.

Changes in blood flow during one stage lengthening of bone: an experimental study in rats.

Distraction osteogenesis is a well-accepted method of bone lengthening. Its disadvantages, however, are that it requires an external fixator and takes a long time. One-stage lengthening therefore offers certain advantages. A first point of reference for the safe limits of this procedure might be the changes of blood flow, and this is also the crucial factor in deciding on the appropriate method of lengthening, particularly where the hand or foot is involved. Using a laser Doppler flowmeter we measured blood flow in the dorsum of the foot after using bilateral minimonofixators to lengthen the tibias of 15 Sprague-Dawley rats. They were lengthened in four stages: stage 0 (before lengthening); stage I--12.5%; stage II--25%; and stage III--31.25% of lengthening. The blood flow during stage I decreased to 79% compared to that of stage 0; 16% during stage II; and 1% during stage III. This study suggests that the maximal permissible extent of lengthening might be less than a quarter according to the blood flow as suggested by this animal model.

Comparison of MR imaging findings between extraligamentous and subligamentous disk herniations in the lumbar spine.

BACKGROUND AND PURPOSE: The method of treating an HIVD in the lumbar spine may depend on the integrity of the PLL. The purpose of this study was to analyze and compare the MR imaging findings of extraligamentous and subligamentous HIVDs in the lumbar spine. MATERIAL AND METHODS: One hundred seventeen patients (M/F = 71:46; mean age, 47 years; age range, 15-79 years) underwent lumbar spine MR imaging and disk surgery (extraligamentous/subligamentous = 66:51) from May 2003 to November 2006. Two radiologists in consensus retrospectively reviewed all MR images, focusing on 10 criteria. RESULTS: The following 5 criteria are suggestive of extraligamentous HIVD in the lumbar spine: 1) spinal canal compromised for more than half its dimension, 2) internal signal difference in the HIVD, 3) an ill-defined margin of the HIVD, 4) disruption of the continuous low-signal-intensity line covering the HIVD, and 5) the presence of an internal dark line in the HIVD (P < .05). When we combined these 5 MR imaging criteria, the sensitivity, specificity, accuracy, and odds ratio were 77.3%, 74.5%, 76.1%, and 9.93 (P < .0001). CONCLUSIONS: Our proposed 5 MR imaging criteria will be helpful in differentiating extraligamentous and subligamentous HIVDs in the lumbar spine.

Characteristic radiographic features of the central ray in Apert syndrome.

We reviewed retrospectively seven patients with Apert acrosyndactyly and measured the size of the capitate ossification centre relative to that of the hamate and determined the relative position of the middle finger metacarpal relative to the ring finger metacarpal. We then compared those parameters in 197 normal children. In all patients, the middle finger metacarpal bone had migrated proximally relative to the ring finger metacarpal and the size of the capitate ossification centre was smaller than that of the hamate. After surgical release of the middle finger, relative proximal migration of the middle finger metacarpal was partially relieved and catch-up growth of the capitate was observed within several months. As fusion of the distal phalanges creates a diamond-shaped configuration, bone growth is markedly impaired in the middle finger ray. Therefore, early separation of the middle finger may be as important as early separation of the border digits.

Assisted procreation in cases of hepatitis B, hepatitis C or human immunodeficiency virus infection of the male partner.

Guidelines for assisted procreation impose a special responsibility upon physicians for the health of the expected child because of their active role in inducing pregnancy. Therefore, careful clinical evaluation of both partners has to precede every application of these methods. Risks for the mother's health or the development of the child count as a relative contraindication for a treatment. To balance these relative contraindications, the existing risk factors have to be recognized through screening examination. If a chronic infection occurs in the male partner, prevention for the female partner is theoretically possible by using a condom. As this inhibits a pregnancy, at least in cases of human immunodeficiency virus and hepatitis C virus infections, realization of a pregnancy requires assisted procreation. The main question in these cases is whether infectious particles can be eliminated by sperm processing to ensure the safe treatment of the healthy female partner.