PubMed Health⌕ Search

Biomedical subjects

K Albrecht

Publications and source records attributed to K Albrecht.

At least 19 recordsLinked to original sources
PubMed2006

Comparative in vivo mucoadhesion studies of thiomer formulations using magnetic resonance imaging and fluorescence detection.

The aim of this study was to compare different oral delivery systems based on the thiolated polymer polycarbophil-cysteine (PCP-Cys) and to provide evidence for the validity of the hypothesis that unhydrated polymers provide better mucoadhesion in vivo. To achieve dry polymer application, a new, experimental dosage form named Eutex (made of Eudragit L100-55 and latex) capsule has been developed. Magnetic resonance imaging was used to localize the point of release of the thiolated polymer from the application forms via the positive magnetic resonance signal from a gadolinium complex (Gd-DTPA). In vivo mucoadhesion was determined by ascertaining the residence time of the fluorescence-tagged thiomer on intestinal mucosa after 3 h. Results showed that in comparison to conventional application forms the Eutex capsules led to 1.9-fold higher mucoadhesive properties of PCP-Cys when compared to application with a conventional enteric-coated capsule, and to 1.4-fold higher mucoadhesion when compared to administration with an enteric-coated tablet of the thiomer. The findings of this study should contribute to the understanding of mucoadhesion and mucoadhesion influencing parameters in vivo and should therefore be of considerable interest for the development of future mucoadhesive oral drug delivery dosage forms.

Animals↗
PubMed2006

Tibial press-fit fixation of the hamstring tendons for ACL-reconstruction.

Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary to achieve fixation. Up till the present point, there is no biomechanical data available for the tibial press-fit fixation of the hamstring tendons. Hamstring tendons of 21 human cadavers (age: 41.9 +/- 13.1 years) were used. A press-fit fixation with looped semitendinosus and gracilis tendons secured by a tape (T) over a bone bridge, or by a baseball-stitched suture (S), was compared with degradable interference screw fixation (I) in 21 porcine tibiae. The constructs were cyclically strained and subsequently loaded to failure. The maximum load to failure, stiffness, and elongation during cyclical loading were measured. The maximum load to failure was highest for the T-fixation at 970 +/- 83 N, followed by the I-fixation with 544 +/- 109 N, and the S-fixation with 402 +/- 78 N (P < 0.03). Stiffness of the constructs averaged 78 +/- 13 N/mm for T, 108 +/- 18 N/mm for S, and 162 +/- 27 N/mm for I (P < 0.03). Elongation during initial cyclical loading was 2.0 +/- 0.6 mm for T, 3.3 +/- 1.1 mm for S, and 1.4 +/- 0.5 mm for I (S inferior to I and T, P<0.05). Elongation between the 20th and 1,500th loading cycle was lower for T (2.2 +/- 0.7 mm) compared with I (4.1 +/- 2.7 mm) and S (4.8 +/- 0.7 mm; P < 0.001). The T-fixation technique exhibited a significantly higher failure load than the S-, and I- techniques. All techniques exhibited larger elongation during initial cyclical loading than is reported in the literature for grafts with bone blocks. Only one technique (T) showed satisfactory elongation behavior during long-term cyclic loading. Interference screw fixation demonstrated significantly higher stiffness. Only one of the investigated techniques (T) seemed to exhibit adequate mechanical properties necessary for early aggressive rehabilitation programs.

Adolescent↗
PubMed2006

Stapled transanal rectal resection (STARR): a new option in the treatment of obstructive defecation syndrome.

BACKGROUND: Rectocele and distal intussusception are organic causes of outlet obstruction. A new surgical option called the stapled transanal rectal resection (STARR) is described within a prospective study. PATIENTS AND METHODS: Fourteen patients with symptomatic rectocele (four females), rectocele with coexistent intussusception (eight females), and intussusception (two males) underwent STARR procedure. The symptoms were measured by means of a defecation score (0-20 points). RESULTS: Complications included local bleeding postoperatively in two cases, and temporary ischuria in four cases. The subjective sense of pain was low; from day 1 postoperatively five patients did not need any analgetics. Only one female patient had prolonged pelvic pain, without any organic reason. All patients showed improvement in rectal evacuation. The mean score of defecation (0-20 points) decreased from 13+/-3 to 4+/-3 after 1 month (p<0.05) and remained low. The overall follow-up was 19+/-9 months. Only one male patient with intussusception had defecation disorder again 6 months after surgery. Three patients had temporary urge incontinence. CONCLUSION: STARR is an effective therapy for obstructive defecation disorder due to a symptomatic rectocele and/or a distal intussusception.

Anal Canal↗
PubMed2006

[The male genital in legal medicine].

Pathomorphological findings for the male genital are an exception among forensic cases. In earlier publications they were usually published as individual cases. A significant percentage are the so-called fertility- and potency medical certificates, which are usually commissioned for doubtful paternity cases. Old forensic writings about genital injuries distinguish--apart from the necessity of a complete dissection--between "deadly as such" and "accidentally deadly" injuries. Another group consists of reports about self-inflicted genital mutilation, e.g. among prison inmates or soldiers of the last world wars to become an invalid. When it was necessary to identify a corpse, e.g. in cases of progressive decomposition, Merkel recommended in 1945 the representation of the so-called "Schnepfenkopf" (snipe head; colliculus seminalis) in the lesser pelvis. In this article a medical and forensic review of forensically relevant findings of the male genital is presented and illustrated with historical cases.

Forensic Medicine↗
PubMed2006

Imbalance of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases: a novel approach for explaining the parenchymal liquefaction of the septic spleen?

OBJECTIVE: The causal pathophysiological mechanisms involved in the parenchymal liquefaction of the septic spleen are still far from clear. The balance between matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), is largely responsible for the remodelling of tissues. Deregulation of this balance is a characteristic of extensive tissue degradation in certain chronic inflammatory diseases. METHODS: This study focuses on a search for alterations in the balance between MMP-1 (interstitial collagenase) and TIMP-1 by means of immunostaining, by immunoblotting, and by gel zymography. RESULTS: We found a deregulation of the balance between MMP-1 and TIMP-1 in the septic spleen in favor of the active form of MMP-1. CONCLUSION: Our findings suggest that active MMP-1 is involved in collagenolytic extracellular matrix breakdown in the septic spleen.

Aged↗
PubMed2006

[Spontaneous ruptures of the urinary bladder in the routine forensic examination].

This article analyses three cases of death following a spontaneous rupture of the urinary bladder. One case is based on an extensive tamponade of the bladder eight days after a transurethral resection of the prostate gland. Two other cases of death by spontaneous rupture resulted from increased alcohol consumption. The paper presents an overview of pathomorphological findings such as the typical intraperitoneal rupture localisation at the posterior wall of the urinary bladder or bladder dome and the subsequent diagnosed causes of death. In addition predisposing (anamnestic) influencing factors such as chronic alcoholism are highlighted and their relevance for the clinical urologist and the forensic pathologist are discussed.

Adult↗
PubMed2005

Evaluation of the correlation between time corpses spent in in-ground graves and findings at exhumation.

To determine how long pathological findings persist after burial and which factors play a role in decomposition of a corpse, we evaluated all bodies exhumed under the auspices of the Institute of Legal Medicine at the Hannover Medical School between 1978 and 1997. A total of 87 exhumations (54 men, 33 women) were performed in this period. The time bodies remained buried varied between 5 days and 16.8 years (mean 1.5 years, median 2.3 months). Fifty-six percent of the bodies were exhumed after at most 3 months, 10% remained buried for greater than 3 years. Pathomorphological changes of the soft tissues and the internal organs remained evident after several months, in some cases after several years of burial. Overall, it was possible to evaluate internal organs after 5 years of burial. Bodies became mostly decomposed after approximately 8 years at the earliest, although it was still possible to evaluate some soft tissue remnants after 16.8 years. In stepwise logistic regression, both the length of time the body was buried (p < 0.00005) and the time of year (p < 0.0019) clearly affected the rate of physical change. The variables of sex (p = 0.33), age (p = 0.61) and changes in the integrity of the body before burial (trauma, autopsy before burial; p = 0.15) did not influence the physical state of the body after exhumation. Our data show that much information may be gained from an exhumation even after significant time has passed since burial.

Adolescent↗
PubMed2005

[The development and biomechanical testing of a femoral press fit fixation for hamstring tendons].

PURPOSE: The purpose of this study was to investigate press fit femoral fixation of hamstring tendons and to compare the mechanical properties with press fit patellar tendon bone (PTB) fixation. METHODS: The PTB and hamstring tendons of 30 human cadavers (age: 55.8+/-18.0 years) were used as grafts. An outside-in press fit fixation with a knot in the semitendinosus and gracilis graft (SG-K) and an inside-out (SG-BI) and an outside-in fixation (SG-BO) with the tendons looped over a bone block were compared with a bone-patellar tendon (PT) press fit fixation in 30 bovine femora. The angle between the direction of force and bone tunnel was 60 degrees. The constructs underwent 20 cycles of loading between 60 and 260 N. Constructs were loaded until failure at a speed of 1 mm/sec. Graft fixation was analyzed in terms of maximum load to failure, stiffness and elongation during cyclic stretching. A video analysis of length changes was investigated. RESULTS: There was a significant difference in the maximum load to failure. The SG-BI fixation was inferior to the other three techniques (Mann-WhitneyU-test, P<0.01). There was no difference in stiffness between the techniques. Length changes of PT-fixation from the first to the fifth loading cycle were significantly smaller compared with all other groups (0.73+/-0.58 mm). There was no significant difference between the groups from the 15th to the 20th cycle of cyclic loading. CONCLUSIONS: Press fit fixation of hamstring grafts is technically challenging. However, pull-out forces for SG-O and SG-K were equivalent to BPT-graft fixation. Adequate preconditioning for all hamstring tendon press fit techniques is crucial.

Anterior Cruciate Ligament↗
PubMed2005

[Sperm stains in legal medicine. An historical review of forensic authentication methods].

Furnishing proof of human seminal stains is part of daily forensic work in investigations of sexual crimes. In the last two centuries different methods have been described for confirming putative sperm traces. These methods ranged from identification of the smell and appearance of the stain, to simple chemical reactions such as precipitation of crystals and enzymatic proof of acid phosphatase, which are now enhanced by analytic methods of modern molecular biology. This discourse gives a review of the development of different forensic methods for detection of sperm traces, illustrated with historical case studies.

Forensic Medicine↗
PubMed2004

Polymorphisms of genes involved in innate immunity: association with preterm delivery.

An altered inflammatory activity due to functionally relevant polymorphisms of the innate immune system may influence pathways leading to labour and, therefore, impact on the frequency of preterm birth. We examined five polymorphisms of the innate immune system in a large cohort of preterm very-low-birth-weight (VLBW, n = 909) and term-born infants (n = 491) and their mothers (n = 747). The primary outcome was preterm versus term birth. Frequencies of polymorphisms in mothers of term-born infants versus mothers of VLBW infants and term infants versus preterm VLBW infants (singletons) are given. Homozygous CD14-159T: 18.5 versus 21.8% (mothers) and 19.6 versus 21.2% (infants). Homozygous interleukin IL-6-174G: 28.8 versus 38% (P = 0.018, mothers) and 30 versus 32.7% (infants). Homozygous or heterozygous nuclear oligomerization domain NOD2-3020insC: 6.9 versus 6.1% (mothers) and 5.7 versus 5.1% (infants). Heterozygous or homozygous toll-like-receptor TLR2-Arg753Gln: 6.9 versus 6.1% (mothers) and 5.7 versus 5.1% (infants). Homozygous or heterozygous TLR4-896G: 8.1 versus 11.5% (mothers) and 11.6 versus 10.5% (infants). Although the homozygous maternal IL-6-174G genotype was found to be independently associated with preterm delivery in multivariate regression analysis, the incidence of intrauterine infection was not significantly increased in mothers of preterm VLBW-infants, carrying this or other polymorphisms of the innate immune system. The overall influence of the investigated polymorphisms on the development of preterm delivery seems moderate, since only the maternal IL6-174G genotype was associated with preterm birth and none of the polymorphisms were associated with intrauterine infection as the cause of preterm birth.

Adult↗
PubMed2004

[The relevance of urinary bladder filling in suprapubic bladder catheterization].

Suprapubic punction of the urinary bladder (cystostomy) may cause typical, sometimes lethal injuries of pelvic organs especially in cases of an insufficient bladder filling. Some of these cases were described in the literature of legal medicine. To verify the importance of the cranial displacement of the vulnerable intestine by a filled bladder, the distances between the upper end of the symphysis and apex vesicae were measured in 76 forensic autopsies in situ and correlated with the filling volume of the urinary bladder. 69,2% of cases with a bladder filling volume up to 200 ml showed a suprapubic distance of only < or =4 cm. However, this distance collides with the preferred clinical intervention point, 2 fingers above the symphysis. In all cases with a bladder filling volume > or =300 ml, the distances were > or =5 cm. Based on our measurements, we recommend a preoperative bladder filling of > or =300 ml for an uncomplicated insertion of a suprapubic catheter.

Cadaver↗
PubMed2004

[The proof of paternity. An andrological-forensic challenge in historical perspective].

For centuries, difficulties have occurred in determining unresolved paternities. In addition to the modern standard methods, such as the examination of DNA or serological proof, expert opinion on fertility once played an important role. The andrological difference between incapability to fertilise and the inability to participate in sexual intercourse was also distinguished historically. Of special significance was the discovery of spermatozoa by the medical student Johan Ham in 1677 and their further investigation by Antoni van Leeuwenhoek.Recently, modern DNA methods have also been applied for historical investigations. Illustrious examples are the DNA analysis in the case of Kaspar Hauser of Ansbach and the dispute about Thomas Jefferson, President of the U.S., fathering a child by one of his slaves. In this discourse, a medicinal-forensic review of the development of expert opinion, illustrated with historical case studies, is given.

Andrology↗
PubMed2004

Proof of paternity: historical reflections on an andrological-forensic challenge.

Throughout the history of medicine, there have been difficulties in forensic proving of unsolved paternities, making this a major andrological-forensic challenge. In the Roman empire, children procreated by incest, called 'incestuosi', had no rights at all and other illegitimates, e.g. children born of prostitutes or as a result of adultery, could not assert rights towards the father. Only through the 'corpus iuris civilis' of the Roman Emperor Justinian I (6th century ad) could claims of alimony be made in some cases. In later times, evidence of presumable impotence of a potential father was determined by the congressus, where defined juristical 'sexual fights' had to be held before official matrons, surgeons and priests. Men had to demonstrate their erectile and ejaculatory function. A special significance must be attributed to the microscopical discovery of spermatozoa by the medical student Johann Ham in 1677 and the further investigation by Antoni van Leeuwenhoek. After centuries of personally biased and scientifically incorrect concepts of paternity determination, the discovery of the blood grouping system by Karl Landsteiner at the beginning of the 20th century paved the way for sophisticated techniques to prove or rather to disprove paternity. In 1921, Reuben Ottenberg from New York was the first to suggest the application of the system to medico-legal questions, but it was not before the 1950s that legal courts accepted this method. A famous example of disregarding clear blood grouping results was the case of the movie star Charles Chaplin in California in 1946. Modern DNA techniques, today the golden standard in forensic medicine, have also been applied recently for historical investigations. One of the very illustrious examples is the dispute about Thomas Jefferson, third President of the US, fathering a child of one of his slaves.

Andrology↗
PubMed2004

[Cricothyroidotomy training on cadavers - experiences in the education of medical students, anaesthetists, and emergency physicians].

OBJECTIVE: Should the technique of surgical cricothyroidotomy be practiced on cadavers and should it be a compulsory part of the teaching curriculum? Is it wise to use a speculum for the insertion of the endotracheal tube? What is the optimum size of the tube? METHODS: A surgical cricothyroidotomy with a speculum was carried out on 30 cadavers from the Institute of Legal Medicine, Medical School Hannover. This took place as part of a official and voluntary course for students of advanced semesters, anaesthetists and emergency doctors with the subjects "cricothyroidotomy, chest drainage and venous cut-down". The surgical cricothyroidotomy without the use of a speculum was carried out on 5 cadavers by two clinicians well practiced in this technique. The elapsed time between skin incision and the insertion of the endotracheal tube was measured on all five subjects. After the course the participants were asked if they were able to carry out a cricothyroidotomy in an emergency. They were also asked whether this course should be a compulsory part of their curriculum and whether practical sessions should take place. During autopsies at the Institute of Legal Medicine the length of the ligamentum conicum was measured on 40 corpses with reclined and non-reclined heads. RESULTS: The average time of storage of the cadavers was 4.2 days +/- 1.9 days. The cricothyroidotomy was possible on all 35 cadavers. In one case (3,3 %) the result was a complete rupture of the cricoid cartilage. In 5 cases (16.7 %) the horizontal incision was torn due to prising with the speculum. Difficult situations always occured when the skin incision was not exactly in the midline. The average time to place the endotracheal tube into the trachea by the surgical procedure of cricothyroidotomy was 22.4 seconds +/- 3.1 seconds (minimum 18 seconds, maximum 26 seconds). 10 % of the medical students and 50 % of the anaesthetists and emergency doctors felt they would be prepared to carry out a cricothyroidotomy in an emergency. 90 % of the students and respectively 80 % of the anaesthetists and emergency doctors stated that they would like to practice the technique on a cadaver again. Almost all participants were of the opinion that the course should be integrated as a compulsory course in a future educational curriculum. The average distance between the thyroid cartilage and the cricoid cartilage was 9.5 mm +/- 1.9 mm with non-reclined head (minimum 6 mm, maximum 14 mm) and 11.9 mm +/- 2.5 mm with reclined head (minimum 7 mm, maximum 18 mm). The average difference of distances was 2.4 mm +/- 1.2 mm (minimum 1 mm, maximum 6 mm) in reclined and non-reclined heads. CONCLUSIONS: In our opinion it is highly recommended that the technique of cricothyroidotomy should be practiced on cadavers and that the course should become a compulsory part in a future educational curriculum. In addition the incision of the ligamentum conicum using dilators or a speculum is not to be recommended from the point of view of this study. The tracheal tube used in this study (reinforced wire tube, ID 6.0) was best suited for surgical cricothyroidotomy.

Anesthesia↗
PubMed2004

[Laparoscopic therapy of appendicovesical fistula -- two case reports].

Two cases of appendicovesical fistula are reported. One case was caused by Crohn's disease, the second case by a chronical appendicitis. The guiding symptoms in both cases were coprosuria and pneumaturia, with chronical infection of the urinary tract. No diagnostic imaging method was able to detect the fistula. The correct diagnosis was finally made by laparoscopy followed by laparoscopical appendicectomy and fistula closure. The clinical symptoms alone seem to be sufficient for indication to operate. Thus, an early laparoscopic operation significantly can shorten the length of disease.

Adult↗
PubMed2004

[Pilonidal Sinus -- Primary Closure also in Case of Abscess?].

After excision of pilonidal sinus treatment consists either in open procedure or primary closure. We present the results of 45 consecutive patients (male 29, female 16, age 32 +/- 13 years), who underwent surgery between September 2001 and December 2002. Fourteen patients had simple fistula without infection, 18 had fistulas with putride secretion and 13 had abscess. Primary closure with direct suture was performed in 34 patients (76 %: 13 x simple fistula, 13 x fistula with putride secretion, 8 x abscess). Eleven patients were treated by layopen procedure and secondary wound healing. Wound infection occurred in 13 patients (7 x superficial, 6 x deep). Mean time of postoperative treatment was 15 +/- 3 days after closure and primary healing and 66 +/- 15 days after open proce dure or secondary healing. Mean time out of work was 19 +/- 10 respectively 52 +/- 19 days. A recurrence of fistula occurred in eight patients after primary closure (18 %) and none after open procedure. Also in cases of pilonidal sinus with infection, primary wound closure can be carried out even though the rate of recurrences is higher than after open procedure. A successful primary closure significantly reduces time of illness and time out of work.

Abscess↗
PubMed2004

Applied anatomy of the superior vena cava-the carina as a landmark to guide central venous catheter placement.

BACKGROUND: Cardiac tamponade is a serious complication of central venous catheter (CVC) insertion. Current guidelines strongly advise that the CVC tip should be located in the superior vena cava (SVC) and outside the pericardial sac. This may be difficult to verify as the exact location of the pericardium cannot be seen on a normal chest x-ray. The carina is an alternative radiographic marker for correct CVC placement, suggested on the basis of studies of embalmed cadavers. METHODS: We set out to confirm this radiographic landmark in 39 fresh cadavers (age 58.4 (3.4) (mean and SE) yr) and to compare the results with those from ethanol-formalin-fixed cadavers. RESULTS: We found that the carina was 0.8 (0.05) cm above the pericardial sac as it transverses the SVC. In no case was the carina inferior to the pericardial reflection and our study confirmed the previous findings. All the measured distances were significantly greater in fresh cadavers. CONCLUSIONS: We confirm that the carina is a reliable, simple anatomical landmark that can be identified in vivo for the correct placement of CVCs outside the boundaries of the pericardial sac.

Adult↗