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Biomedical subjects

H D Becker

Publications and source records attributed to H D Becker.

At least 19 recordsLinked to original sources
PubMed1999

[Diagnosis and therapy of tumor of Vater's ampulla].

BACKGROUND AND OBJECTIVE: Complete removal of tumours of the ampulla (papilla) of Vater is generally recommended, because of the known adenoma-carcinoma sequence yet the uncertainty regarding diagnosis of dignity of such tumours. The aim of this study was tho analyse different treatment concepts on the basis of data from a personal series of cases. PATIENTS AND METHODS: Clinical, laboratory and histological data as well as treatment and course in nine patients (three women, six men; mean age 62 [46-82] years) with ampulla of Vater adenoma, treated at one hospital, were analysed retrospectively. The patients had been followed for 6-36 months. RESULTS: All tumours had been removed endoscopically. Partial duodenopancreatectomy had subsequently been performed in two patients because of severe dysplasia. One tumour with moderately severe dysplasia had recurred locally within two months of endoscopic removal and was resected transduodenally. There had been no further recurrences 3 to 36 months later. CONCLUSION: If there is no evidence of malignity and frequent follow-up can be ensured, endoscopic removal of a tumour of the ampulla of Vater is justified. Otherwise transduodenal excision of the ampulla or partial duodenopancreatectomy should be undertaken.

Adenoma↗
PubMed1999

[The wound care center in surgery: an interdisciplinary concept for diagnostic and treatment of chronic wounds].

In Germany there is no standardized wound care for patients with chronic wounds in specialized centers. We have established a wound care unit for the past 6 years. The principal concept of therapy was characterized by standardized local surgery, moist wound dressings and concomitant treatment of the underlying disease. We performed local therapy, coordinated the interdisciplinary treatment and developed a new wound documentation system for quality control. We established a close network, integrating general practitioners and home care organizations to realize a mainly outpatient treatment supported by short hospital therapy. Exclusive outpatient treatment was performed in 42% of all patients. According to our prospective data, we achieved an improvement in wound care: 69% of the wounds resistant to therapy for a mean of 30 months healed within 12 months after therapy according to our protocol. Our data strongly supported the importance of local surgery: neither wound depth nor wound infection had any influence on the healing rate, presumably due to radical excisional debridement of necrotic tissue. The presented data justify on medical and economic grounds the establishment of such wound care centers in Germany.

Ambulatory Care↗
PubMed1999

[Immune regulation of wound healing].

Wound healing is a complex cascade of biochemical and cellular events designed to achieve restoration of tissue integrity following injury. Immune cells are critical for the outcome of healing. Much has been learned about the individual events that are involved in this process. Knowledge is scant, however, about the spatial and temporal interweaving of these events and how one step sets the stage for subsequent observed phenomena. Imbalance of stimulating and inhibiting factors causes failure of healing. Immunosuppressive states interfere with a normal immune response and impair wound repair. Clinically, new therapeutic approaches to modulate impaired healing are based on a knowledge of immune regulation of wound healing.

Animals↗
PubMed1999

Introducing fluorine-18 fluoromisonidazole positron emission tomography for the localisation and quantification of pig liver hypoxia.

Fluorine-18 labelled fluoromisonidazole ([18F]FMISO) has been shown to accumulate in hypoxic tissue in inverse proportion to tissue oxygenation. In order to evaluate the potential of [18F]FMISO as a possible positron emission tomography (PET) tracer for imaging of liver tissue hypoxia, we measured the [18F]FMISO uptake in 13 domestic pigs using dynamic PET scanning. Hypoxia was induced by segmental arterial hepatic occlusion. During the experimental procedure the fractional concentration of inspired oxygen (FiO2) was set to 0.67 in group A (n=6) and to 0.21 in group B (n=7) animals. Before and after arterial occlusion, the partial pressure of O2 in tissue (TPO2) and the arterial blood flow were determined in normal flow and flow-impaired liver segments. Standardised uptake values [SUV=kBq tissue (in g) / body weight (in kg) x injected dose (in kBq)] for [18F]FMISO were calculated from PET images obtained 3 hours after injection of about 10 MBq/kg body weight [18F]FMISO. Immediately before PET scanning, the mean arterial blood flow was significantly decreased in arterially occluded segments [group A: 0. 41 (0.32-0.52); group B: 0.24 (0.16-0.33) ml min-1 g-1] compared with normal flow segments [group A: 1.05 (0.76-1.46); group B: 1.14 (0.83-1.57) ml min-1 g-1; geometric mean (95% confidence limits); P<0.001 for both groups]. After PET scanning, the TPO2 of occluded segments (group A: 5.1 (4.1-6.4); group B: 3.5 (2.6-4.9) mmHg] was significantly decreased compared with normal flow segments [group A: 26.4 (21.2-33.0); group B: 18.2 (13.3-25.1) mmHg; P<0.001 for both groups]. During the 3-h PET scan, the mean [18F]FMISO SUV determined in occluded segments increased significantly to 3.84 (3.12-4.72) in group A and 5.7 (4.71-6.9) in group B, while the SUV remained unchanged in corresponding normal liver tissue [group A: 1.4 (1.14-1. 71); group B: 1.31 (1.09-1.57); P<0.001 for both groups]. Regardless of ventilation conditions, a significant inverse exponential relationship was found between the TPO2 and the [18F]FMISO SUV (r2=0. 88, P<0.001). Our results suggest that because tracer delivery to hypoxic tissues was maintained by the portal circulation, the [18F]FMISO accumulation in the liver was found to be directly related to the severity of tissue hypoxia. Thus, [18F]FMISO PET allows in vivo quantification of pig liver hypoxia using simple SUV analysis as long as tracer delivery is not critically reduced.

Animals↗
PubMed1999

Allogenic bone graft viability after hip revision arthroplasty assessed by dynamic [18F]fluoride ion positron emission tomography.

The biological fate of allogenic bone grafts in the acetabular cavity and their metabolic activity after acetabular augmentation is uncertain but is most important for the stability of hip implants after hip revision arthroplasty. The aim of this study was to quantify regional bone metabolism after hip replacement operations. Dynamic [18F]fluoride ion positron emission tomography (PET) was used to investigate the metabolic activity of acetabular allogenic bone grafts and genuine bone, either 3-6 weeks (short-term group, n = 9) or 5 months to 9 years (long-term group, n = 10) after hip revision arthroplasty. Applying a three-compartment model, the fluoride influx constant was calculated from individually fitted rate constants (Knlf) and by Patlak graphical analysis (Kpat). The results were compared with genuine cancellous and cortical acetabular bone of contralateral hips without surgical trauma (n = 7). In genuine cortical bone, Knlf was significantly increased in short- (+140.9%) and long-term (+100.0%) groups compared with contralateral hips. Allogenic bone grafts were characterised by a significantly increased Knlf in the short-term group (+190.9%) compared with contralateral hips, but decreased almost to the baseline levels of contralateral hips (+45.5%) in the long-term. Values of Knlf cor-related with the rate constant K1 in genuine (r = 0.89, P<0.001) and allogenic bone regions (r = 0.79, P<0.001), indicating a coupling between bone blood flow and bone metabolism in genuine bone as well as allogenic bone grafts. Kpat values were highly correlated with Knlf measurements in all regions. In conclusion, [18F]fluoride ion PET revealed the presence of an increased host bone formation in allogenic bone grafts early after hip revision arthroplasty. In contrast to genuine cortical bone, allogenic bone graft metabolism decreased over time, possibly due to a reduced ability to respond to the same extent as genuine bone to elevated metabolic demands after surgery.

Aged↗
PubMed1999

Correlation of imaging techniques to histopathology in patients with diabetic foot syndrome and clinical suspicion of chronic osteomyelitis. The role of high-resolution ultrasound.

OBJECTIVE: To investigate the role of ultrasound in the diagnosis of osteomyelitis in the diabetic foot compared with magnetic resonance imaging (MRI), bone scintigraphy (BS), and plain film radiography (PFR). RESEARCH DESIGN AND METHODS: We investigated 19 consecutive diabetic patients (2 women, 17 men, age 60.7 +/- 9.8 years, BMI 27.0 +/- 3.8 kg/m2) with clinical suspicion of bone infection of the foot. A high-resolution ultrasound system (Esaote/Biosound, Munich) with a linear array transducer up to 13.0 MHz was used. The prospective and blinded results of each method were compared with histopathology as the reference method after metatarsal resection. RESULTS: In 14 of 19 patients, histopathology confirmed osteomyelitis. Ultrasound showed a sensitivity of 79% (PFR, 69%; BS, 83%; MRI, 100%), a specificity of 80% (PFR, 80%; BS, 75%; MRI, 75%), a positive predictive value of 92% (PFR, 90%; BS, 91%; MRI, 93%), and a negative predictive value of 57% (PFR, 50%; BS, 60%; MRI, 100%). CONCLUSIONS: Our data indicate that ultrasound might have a better diagnostic power for detecting chronic osteomyelitis in the diabetic foot than PFR and has similar sensitivity and specificity as BS. MRI is superior to the other three methods. We conclude that the use of ultrasound in the management of the diabetic foot is worthy of further investigation.

Diabetic Foot↗
PubMed1999

[Standardized wound documentation of chronic wounds].

Owing to the long periods of treatment and multi-factoral etiology of chronic wounds, standardized wound documentation is necessary to enable judgement of the course of healing. We have developed a documentation system which permits a standardized assessment of chronic wounds by means of defined parameters and graded divisions. Besides containing the diagnostic and therapeutic measures which have been carried out, the documentation should also contain parameters of wound healing. These are the following: wound localisation, size of wound, degree of injury, infection, and wound morphology. Planimetry and photographic documentation complete the documentation. Thus a documented course of healing can be presented, which enables rapid retrospective analysis and, if needed, a change in therapeutic approach at an early stage. This complete, exact documentation is required by modern administration of justice and is a protection against the reversal of the onus of proof in lawsuits. The extent of documentation can be adapted to the individual needs of the institution responsible for treatment. However, a minimal amount of documentation should always include localisation of the wound, size, the diagnostic and therapeutic measures, and complications if any.

Chronic Disease↗
PubMed1999

[Temporary expression pattern in wound secretions and peripheral wound biopsies].

The local availability of growth factors and oxygen plays an important role in the healing of cutaneous lesions. We were able to quantify the ischemia in a standardized ischemic full-wall flap by measuring the ptiO2, and investigate the healing of defined wounds. The analysis of the immune histochemical section showed a significantly reduced expression of IGF-I in the wound edge of ischemic wounds. Simultaneously the rate of proliferation was reduced here. Probably the local chronic hypoxia leads to reduced IGF-I synthesis and thus to reduced proliferation and delayed wound healing. Further investigation is necessary to confirm this hypothesis. In a clinical study of wounds which had been treated with vacuum sealing we could establish no difference in the concentration of IGF-I in the wound fluid of seriously contaminated wounds in comparison to primary fasciotomy wounds. We therefore postulate a primary endocrinal secretion for IGF-I in cases of cutaneous wound healing; higher local consumption or reduced serum levels could stimulate the autocrinal local secretion of IGF-I. Further investigation is, however, needed in order to confirm this hypothesis.

Animals↗
PubMed1998

Thermus thermophilus: a link in evolution of the tRNA-dependent amino acid amidation pathways.

Thermus thermophilus possesses an aspartyl-tRNA synthetase (AspRS2) able to aspartylate efficiently tRNAAsp and tRNAAsn. Aspartate mischarged on tRNAAsn then is converted into asparagine by an omega amidase that differs structurally from all known asparagine synthetases. However, aspartate is not misincorporated into proteins because the binding capacity of aminoacylated tRNAAsn to elongation factor Tu is only conferred by conversion of aspartate into asparagine. T. thermophilus additionally contains a second aspartyl-tRNA synthetase (AspRS1) able to aspartylate tRNAAsp and an asparaginyl-tRNA synthetase able to charge tRNAAsn with free asparagine, although the organism does not contain a tRNA-independent asparagine synthetase. In contrast to the duplicated pathway of tRNA asparaginylation, tRNA glutaminylation occurs in the thermophile via the usual pathway by using glutaminyl-tRNA synthetase and free glutamine synthesized by glutamine synthetase that is unique. T. thermophilus is able to ensure tRNA aminoacylation by alternative routes involving either the direct pathway or by conversion of amino acid mischarged on tRNA. These findings shed light on the interrelation between the tRNA-dependent and tRNA-independent pathways of amino acid amidation and on the processes involved in fidelity of the aminoacylation systems.

Amino Acid Sequence↗
PubMed1998

[Achalasia: botulinus toxin, interventional balloon dilatation, myotomy?].

67 patients with achalasia were treated either medically, endoscopically or surgically from 1987 to 1997 in the Department of Surgery of the University of Tübingen. 27/67 (40%) of the patients, who were pneumatically dilatated, had a very successful therapy within the first year after dilatations. 12/67 (17%) of the patients had good results with a dysphagia score less than 1 after dilatations within the first year. The perforation rate of interventionally treated patients was 1.4% without any surgical procedure. Open myotomy according to Heller was performed in 28 of 67 patients (41%); after 1993 a laparoscopic procedure was performed in all patients. The average hospitalization for MIC was 5.4 days. The manometric control investigations showed a decrease of the basal LES pressure from preoperative values. When evaluated manometrically 87% showed good results in the follow up time of at least 24 months. 14% of those who underwent surgery had to be endoscopically dilatated after surgery.

Botulinum Toxins↗
PubMed1998

Tacrolimus impairs wound healing: a possible role of decreased nitric oxide synthesis.

BACKGROUND: The effect of the immunosuppressant tacrolimus on wound healing is not known. Tacrolimus has been shown to decrease nitric oxide synthesis. The systemic inhibition of wound nitric oxide synthesis leads to impaired healing. METHODS: We studied the effect of systemic tacrolimus treatment on wound-breaking strength and collagen deposition 10 days after wounding in rats and to correlate the outcome of healing with wound nitric oxide synthesis. Beginning at the day of wounding, rats were treated once daily by intraperitoneal injections with 0.5, 1.0, or 2.0 mg tacrolimus/kg body weight. Nitrite and nitrate were measured in wound fluid as an index of wound nitric oxide synthesis. Expression of inducible nitric oxide synthase in the wound was investigated by immunohistochemistry. Splenic lymphocytes were tested for proliferative activity. Tacrolimus levels in blood and wound fluid were measured by enzyme-linked immunosorbent assay. RESULTS: Systemic tacrolimus treatment was well tolerated by all rats. Tacrolimus accumulated in wound fluid. Tacrolimus levels in wound fluid were found to be approximately 10-fold higher than blood levels (P < 0.001). Tacrolimus (2.0 mg/kg/day) reduced wound-breaking strength (P < 0.01) and collagen deposition (P < 0.05). This was paralleled by decreased wound nitrite + nitrate levels (P < 0.001) and wound-inducible nitric oxide synthase expression. Splenic lymphocyte proliferative activity was significantly decreased by 1.0 and 2.0 mg tacrolimus/kg body weight/day (P < 0.05), indicating that the tacrolimus doses used were immunosuppressive. CONCLUSION: Our data show for the first time that tacrolimus impairs wound healing, and this is reflected by diminished wound nitric oxide synthesis.

Animals↗
PubMed1998

A model to investigate postoperative ileus with strain gauge transducers in awake rats.

BACKGROUND: Postoperative ileus influences patients well-being, hospital stay, and health cost, and postoperative inhibition of colonic motility is a major contributor to postoperative ileus. Experimental models for investigating postoperative ileus are needed. In particular, recording of postoperative colonic motility in awake rats has not been described yet. MATERIAL AND METHODS: Gastric, small intestinal, and colonic motility were recorded with strain gauge transducers in awake rats, and the effects of anesthesia and abdominal surgery on gastrointestinal motility were investigated. RESULTS: Ether anesthesia increased gastric motility and inhibited small intestinal motility, while enflurane anesthesia had only minor effects on gastrointestinal motility. Abdominal surgery inhibited gastric, small intestinal, and colonic motility, and a detailed analysis of gastrointestinal motility in our postoperative ileus model is given. CONCLUSIONS: We established a model to record gastric, small intestinal, and colonic motility in awake rats postoperatively. We could demonstrate that enflurane anesthesia had little effect on gastrointestinal motility, while laparotomy and short manipulation of the cecum produced a prolonged inhibition of gastrointestinal motility. Our model could be used to investigate postoperative ileus, particularly of the colon, in awake rats.

Abdomen↗
PubMed1998

Diagnosis and management of metastatic gastrinoma by multimodality treatment including liver transplantation: report of a case.

Neuroendocrine tumors of the pancreas are being recognized with increasing frequency, not because the incidence has increased, but as a result of improvements in diagnostic tools such as radioimmunoassays for a variety of circulating peptides, and imaging methods that include positron emission tomography (PET) and immunoscintigraphy. Nevertheless, establishing the diagnosis of a neuroendocrine tumor is always a challenge to the clinician from both diagnostic and therapeutic perspectives. Liver transplantation as the ultimate therapeutic, or at least palliative, option for hepatic metastases has produced contradictory results over the past decade. We report herein the case of a 23-year-old woman who, after being diagnosed with gastrinoma in 1989, underwent the complete therapeutic array including liver transplantation for hepatic metastases in 1991. Although an extrahepatic tumor recurred 2 years later, for which double chemotherapy with 5-FU and streptozotocin was given, she is currently leading a normal life with a full-time job. This case prompted a critical review of the current literature on diagnosis and medical and surgical treatment.

Adult↗
PubMed1998

Functional results after transanal rectal advancement flap repair of trans-sphincteric fistula.

BACKGROUND: Transanal rectal advancement flap repair is an operation to treat trans-sphincteric fistula which leaves the external sphincter muscle essentially untouched. Anal sphincter function was evaluated prospectively before and after this procedure. METHODS: Anorectal manometry was performed in 24 patients before operation and 3 months after surgery. A detailed standardized questionnaire on faecal continence was answered before surgery, then at 3 and 48 months after surgery. RESULTS: No significant differences were seen between mean(s.e.m.) preoperative and postoperative values for maximum squeeze pressure (100.0(9.7) versus 118.0(12.7) mmHg), maximum resting pressure (56.6(4.3) versus 52.8(4.1) mmHg), rectal compliance (4.4(0.6) versus 3.5(0.5) ml/mmHg) or any other parameter of anorectal manometry. The questionnaire revealed the occurrence of minor incontinence in two patients following surgery, which remained unchanged for 4 years. Three other patients had continence disturbances 4 years after surgery which were probably unrelated to the procedure. CONCLUSION: In addition to high success rates, transanal rectal advancement flap repair also yields excellent functional results. This procedure should be performed for trans-sphincteric fistula in place of alternative treatments whenever feasible.

Adult↗
PubMed1998

Lower esophageal sphincter measurement in four different quadrants in normals and patients with achalasia.

In order to determine the endoluminal pressure force distribution, the pressure in the lower esophageal sphincter (LES) and esophageal body was recorded in healthy volunteers and patients with achalasia, using a new waterperfused circular four-channel-sleeve (FCS) manometry catheter. The median lower esophageal sphincter pressure (LESP) and interquartile range in healthy control subjects (group 1) was significantly higher in the left lateral quadrant: 37 (28-43) mmHg (channel III) (P < 0.001), in comparison to the right lateral: 24 (20-25) mmHg (channel I), anterior: 22 (18-30) mmHg (channel II), and posterior quadrant: 24 (22-28) mmHg (channel IV). The median LESP in achalasic patients (group 2) was significantly increased in channel I: 31 (27-36) mmHg, channel II: 35 (28-39) mmHg, and in channel IV: 29 (26-237) mmHg (P < 0.001) when compared to controls. The detected pressure of the left lateral quadrant of the LES was not found to be significantly different from controls: 38 (29-39) mmHg. The median contraction amplitude of healthy subjects was significantly higher when compared with achalasic patients (P < 0.001). In patients with achalasia (group 2) the median contraction amplitude of the proximal esophagus was significantly higher than the distal contraction amplitude. In contrast, healthy volunteers showed a reverse relationship. No asymmetric pressure force was detected with the FCS in the proximal or distal esophageal body in either group. In conclusion, the abolition of the normal manometric LES asymmetry in patients with achalasia might indicate regional variations of muscle functions in the high pressure zone of the gastroesophageal junction (GEJ).

Adult↗
PubMed1998

Parathyroid hormone after adenectomy for primary hyperparathyroidism. A study of peptide hormone elimination kinetics in humans.

The study of the elimination kinetics of peptide hormones in humans is limited, because determining hormone levels in different compartments is difficult. We calculated the elimination kinetics of intact PTH (1-84) after adenoma removal in primary hyperparathyroidism, based on a 2-compartment model. In 12 patients, blood samples were drawn in short intervals preoperatively, during surgery, and up to 4 days postoperatively. Plasma levels of PTH (1-84), calcium (Ca), and inorganic phosphate were determined. PTH (1-84) levels remained constant before surgery and during adenoma preparation; 2.5 min after clamping of the adenoma's blood supply, PTH (1-84) decreased (34.9 +/- 4.8 vs. 23.3 +/- 2.9 pmol/L, mean +/- SEM, P < 0.001) and then reached a minimum of 0.96 +/- 0.06 pmol/L at 5 h. The elimination half-lives for PTH (1-84) were 3.43 +/- 0.1 min and 81.7 +/- 12.7 min. Ionized Ca started to decrease 30 min after adenoma removal (1.58 +/- 0.04 vs. 1.56 +/- 0.04 pmol/L, P < 0.001). This decrease was paralleled by a decrease in total Ca. Inorganic phosphate increased 24 h after adenoma removal. In conclusion, PTH (1-84) elimination after adenectomy is characterized by a rapid initial decrease and a subsequent prolonged period with a lower elimination rate. This elimination pattern may also apply to other human peptide hormones.

Adenoma↗