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Biomedical subjects

H Becker

Publications and source records attributed to H Becker.

At least 163 records · Page 9Linked to original sources
PubMed1998

Involvement of the mevalonic acid pathway and the glyceraldehyde-pyruvate pathway in terpenoid biosynthesis of the liverworts Ricciocarpos natans and Conocephalum conicum.

The incorporation of 13C-labeled glucose into borneol, bornyl acetate, the sesquiterpenes cubebanol and ricciocarpin A, phytol, and stigmasterol has been studied in axenic cultures of the liverworts Ricciocarpos natans and Conocephalum conicum. Quantitative 13C NMR spectroscopic analysis of the resulting labeling patterns showed that the isoprene building blocks of the sesquiterpenes and stigmasterol are built up via the mevalonic acid pathway, whereas the isoprene units of the monoterpenes and the diterpene phytol are exclusively derived from the glyceraldehyde-pyruvate pathway. These results indicate the involvement of both isopentenyl diphosphate biosynthetic pathways in different cellular compartments.

Camphanes↗
PubMed1998

[Remission ratio of chronic urticaria--"spontaneous" healing or result of eradication of Helicobacter pylori?].

Helicobacter pylori infection has been assumed to be the underlying cause of some dermatological diseases such as, chronic urticaria. In order to investigate this problem we interviewed 55 patients with chronic urticaria concerning the state of the disease approximately 10 months after being discharged from hospital. After an additional six months we interviewed them for a second time and thus determined the remission ratio. There was no significant evidence showing that a link exists between urticaria and proven Helicobacter pylori infection (chi 2-Test). There was also no significant correlation in the remission ratio between patients treated with a triple therapy and non-treated patients (exact Fisher-Test).

Chronic Disease↗
PubMed1998

The role of spinal angiography in operations on the thoracic aorta: myth or reality?

BACKGROUND: The importance of preserving the artery of Adamkiewicz during replacement of the thoracoabdominal aorta is debated. We report our experience with the use of preoperative spinal angiography and modification of the surgical technique. METHODS: Between September 1993 and March 1996, 46 patients (mean age, 57 years; range, 25 to 73 years) underwent spinal angiography at our institution, 23 for an aneurysm and 23 for chronic dissection. Localization of the artery of Adamkiewicz between T-9 and L-3 was successful in 30 (65%) patients: T-9, left = 2, right = 1; T-10, left = 4; T-11, left = 10, right = 2; T-12, left = 3, right = 1; L-1, left = 1, right = 2; L-2, left = 2, right = 1; and L-3, left = 1. Thirty-one patients subsequently underwent replacement of the descending thoracic aorta and 13 underwent replacement of the thoracoabdominal aorta. Left atrial-femoral artery bypass was used in 23 patients and full extracorporeal circulation was used in 20 patients. Twelve procedures included the reimplantation of crucial intercostal/lumbar branches. RESULTS: The operative mortality rate was 6.8% (3 of 44 patients) and 1 (2.27%) patient had paraparesis. In addition to the 12 patients who underwent targeted reimplantation of the intercostal branches, evaluation of the spinal cord blood supply influenced the operative technique in 19 other patients. CONCLUSIONS: Selective angiography can demonstrate the spinal cord blood supply even in patients with complex aortic pathology. It is a helpful tool for planning extensive replacement of the thoracic and thoracoabdominal aorta.

Adult↗
PubMed1998

[Window width as a dosage-relevant factor in high-contrast structures in CT].

PURPOSE: To establish the relationship between window width and dose to be applied in low-dose high-resolution (HR) computed tomography (CT). MATERIAL AND METHODS: Low-dose HR CT-scans of the petrous bone displayed with different window values were analyzed for identification of osseous details. For two homogeneous phantoms, standard deviation of CT-numbers were measured in order to calculate the fraction of pixels not displayed within the correct grey level. RESULTS: The broadest window used (4000 HU) allowed the best distinction of osseous structures. Standard deviation of CT-numbers in the phantoms varied between 28.5 and 43.2 (mean = 33.6) HU. Thus, only 26.6% of all pixels are displayed in the correct grey level for a 1000 HU-window, but 82.3% for a 4000 HU-window. CONCLUSION: When using low doses and HR-reconstruction algorithms, large window widths allow for an optimal assessment of high-contrast structures. Under these conditions, even high standard deviations of the CT-numbers will not compromise image evaluation. Due to the restricted number of grey-levels that can be distinguished by the human eye, image noise is compressed into a smaller number of discernable grey-levels. Because of the inverse square root function between dose to be applied and window width used (derived in the article), an even minor enlargement of window permits considerable reductions of patient exposure while the discernable image noise remains constant.

Artifacts↗
PubMed1998

Impact of a theory based intervention to increase bicycle helmet use in low income children.

OBJECTIVE: While community interventions to increase bicycle helmet use have increased markedly, few of these studies are theoretically based. The purpose of this study was to determine relationships among PRECEDE model predictors and self reported helmet use among 407 fourth graders from nine low income, non-urban schools. SETTING: Low income schools, with high minority populations in eight nonmetropolitan Central Texas counties were chosen. METHODS: Schools were randomly assigned in a repeated measures design to either classroom only, parent-child, or control groups. School nurses were educated by the researchers to present a head injury prevention program in all but the experimental schools. Researchers made contact by phone with the parents of children in the parent-child group. RESULTS AND CONCLUSIONS: Participation in either of the educational interventions, followed by belief that helmets protect your head (a predisposing factor), and participation in the parent intervention condition, added significant unique variance to the prediction of helmet use after helmet ownership is accounted. These four variables, taken together, account for 72% of the variance in predicting bicycle helmet use.

Accident Prevention↗
PubMed1998

Serous adenoma of the pancreas with multiple microcysts communicating with the pancreatic duct.

The rare neoplastic cystic adenomas of the pancreas form two groups of tumors: macrocystic mucinous and microcystic serous adenomas. Both entities show specific radiologic and histologic features. Several recent case reports, however, suggest some diversity within the group of microcystic serous adenomas. We present the case of a young man operated because of epigastric pain for 12 months and a palpable microcystic tumor of the pancreatic head. Multiple cysts communicating with branches of the pancreatic duct in an alveolar-like pattern were demonstrated on endoscopic retrograde cholangiopancreatography. Histologic examination of the specimen confirmed the diagnosis of a serous adenoma of the pancreas. The tumor morphology in this case may suggest a ductal origin of microcystic serous adenomas.

Adenoma↗
PubMed1998

Cushing's syndrome due to ectopic adrenocorticotropic hormone production by a non-metastatic gastrinoma after long-term conservative treatment of Zollinger-Ellison syndrome.

This report concerns a case of a Cushing's syndrome 10 years after first diagnosis of a Zollinger-Ellison syndrome within the same patient. In a 69-year-old female patient symptoms of hypergastrinaemia have been successfully treated with a proton pump inhibitor. Cushing's syndrome was the result of ectopic adrenocorticotropic hormone production by a large cystic gastrin-producing tumour of the pancreatic tail. After resection by subtotal pancreatectomy serum adrenocorticotropic hormone, cortisol, gastrin levels and secretin infusion test returned to normal. In contrast to all other previously published cases of ectopic adrenocorticotropic hormone syndrome associated with Zollinger-Ellison syndrome, this tumour had not metastasized into the liver and did not show local invasive growth.

Adrenocorticotropic Hormone↗
PubMed1998

[Detection of disseminated carcinoma cells in bone marrow and peripheral blood in primary breast cancer with RT/PCR of parathyroid hormone-related protein (PTHrP)].

The analysis of tissue specific gene expression by reverse transcription based RT/PCR methods is currently evaluated as a method for the detection of tumor cell dissemination in patients with cancer. Breast cancer tissues express PTHrP and the level of PTHrP expression in the primary tumor correlates with the incidence of metastases in the bone. We applied a RT/PCR assay of PTHrP to detect tumor cells in the mononuclear cell fraction of peripheral blood (pb) and bone marrow (bm) of patients with newly diagnosed breast cancer. PTHrP positivity was found in 18/67 pb and 20/71 bm samples. In a median follow up of 23 months there were 7 metastatic relapses (4 osseous, 2 hepatic, 1 pulmonary) and 9 local relapses in patients with primary lymph node positive breast cancer. The hepatic and pulmonary relapses had been both PTHrP-PCR negative in pb and in bm. Of the 4 patients with metastatic relapses to the bone the samples of bm had been initially negative in all cases, the pb had been positive in 2 cases. Of the 9 patients with local recurrences the pb alone had been positive in 4 patients, 5 patients had been negative in both the pb and the bm. During the period of observation there was no local and metastatic relapse detectable in the group of patients with primary lymph node negative breast cancer. In summary the increased risk for local or systemic relapse would have been predictable by RT/PCR of PTHrP alone in pb in 4 of the 9 local and in 2 of the 7 early metastatic relapses. Further follow-up of the patient cohort analysed is needed to assess the value of the RT/PCR of PTHrP as a prognostic and predictive marker in patients with breast cancer.

Adult↗
PubMed1998

[HNPCC-associated stomach carcinomas display aggressive growth in orthotopic transplantation to the SCID mouse].

The accumulation of malignant tumors in a single family, as well as the early onset of the disease, are highly suggestive of a hereditary condition. The evidence of microsatellite instabilities suggest a disease that might be associated with the HNPCC-syndromee. In contrary to the favourable prognosis of colorectal cancer associated with the HNPCC-syndromee we found in our animal model a far more aggressive progression of the disease in patients with HNPCC-associated gastric carcinomas than in patients with sporadic gastric carcinomas. This observation is consistent with the clinical course. Therefore, gastric carcinomas that are associated with the HNPCC-syndromee seem to represent a separate group of HNPCC-associated carcinomas and may even represent another hereditary disease.

Animals↗
PubMed1998

Clinical data for use in assessing quality: lessons learned from the Texas Nurses' Association Report Card Project.

The purpose of this report is to describe the Texas Nurses' Association Report Card Project. As part of ANA's Safety and Quality Initiative, the project was designed as a feasibility study to determine whether clinically based quality indicator data could be collected in standard ways across acute care agencies in Texas. Clinicians from 12 agencies, under leadership of the professional association (Texas Nurses' Association), participated in this initial effort to reach consensus on clinical indicator definitions and on how to collect clinical data for each indicator. Data were collected for falls and injuries, bacteremias, pressure ulcers, skill mix, nursing hours per patient day, patient satisfaction (with nursing, hospital stay, education, and pain management), and nurse satisfaction. The process used is described, as well as the findings and the lessons learned. The importance of standard definitions and precise and standard primary sources for the data are emphasized for the phase II report card efforts to follow.

Data Interpretation, Statistical↗
PubMed1998

[Ambulatory co-disciplinary risk-adjusted preoperative care].

Routine preoperative studies in asymptomatic patients are not helpful for perioperative risk evaluation, and the cost is considerable. The decision regarding the status of a patient for elective surgery can be accurately predicted in 95% of cases on the basis of a complete history and physical examination alone; selective testing should be preferred. Interdisciplinary outpatient premedication is suitable for an individual risk evaluation, and a significant reduction in cost and inpatient treatment.

Adult↗
PubMed1998

[Cause-oriented prevention of nosocomial pneumonia: the HI-LO EVAC tube].

Surgical high-risk patients were studied in a prospective randomized trial regarding nosocomial pneumonia (NP) using a subglottic lavage (SL). A total of 100 patients were investigated, in whom the primary infection was localized in the oropharynx. Independent of the kind of stress ulcer prophylaxis, intermittent subglottic lavage reduces the incidence of NP drastically to 3%, which is however, without statistical significance.

Critical Care↗
PubMed1998

[Effect of ultrasonic diagnosis and incidence of appendectomy and laparoscopy].

A total of 330 of 409 patients with suspected acute appendicitis were examined by ultrasound, and an appendectomy was performed in 146 patients. The negative appendectomy rate was 7% with preoperative ultrasound (n = 72) compared with 31% without (n = 74). Laparoscopy did not reduce the negative appendectomy rate, but was useful in patients with opposing clinical and sonographical findings.

Abdomen, Acute↗
PubMed1998

[Effect of MR mammography on surgical procedure in operative treatment of breast cancer].

In addition to conventional imaging techniques, magnetic resonance (MR) mammography is an important tool in the diagnosis of breast cancer. It has proved to be the method of choice especially for the differential diagnosis of discrepant findings between mammography and ultrasound as well as the detection of multifocal and multicentric disease. In this context MR mammography is a meaningful method for the planning of breast preserving surgery and seems likely to become routine practice as long as the preconditions for high quality performance are guaranteed.

Adult↗
PubMed1997

Anti-carcinoembryonic antigen antibodies versus somatostatin analogs in the detection of metastatic medullary thyroid carcinoma: are carcinoembryonic antigen and somatostatin receptor expression prognostic factors?

BACKGROUND: Surgery is currently the only potentially curative approach in the treatment of medullary thyroid carcinoma (MTC). In many instances however, postsurgically elevated or rising plasma calcitonin and/or carcinoembryonic antigen (CEA) levels indicate persistent metastatic disease, although conventional diagnostic procedures (computed tomography (CT), magnetic resonance imaging (MRI), and invasive venous catheterization) fail to localize the responsible lesions. Recently, anti-CEA antibodies and somatostatin analogs have shown promising results in the staging of MTC. The aim of this study was to compare the sensitivity of both methodologies, especially for the detection of occult MTC, and to assess whether there may be correlations between the scintigraphic behavior and the patients' prognosis. METHODS: A total of 26 patients with medullary thyroid carcinoma were examined at our institution between 1977 and 1996. Ten of them had known disease, 14 had occult metastatic MTC, and 2 were free of disease at the time of presentation. Fourteen patients were investigated with anti-CEA monoclonal antibodies (MAbs) (receiving a total of 35 injections: clones BW431/26, BW431/31, IMACIS, or F023C5, labeled with 99mTc, (111)In or (131)I), and 8 patients were studied with (111)In-labeled octreotide. Two patients received potentially therapeutic doses of (131)I-labeled anti-CEA antibodies. All patients underwent conventional radiologic evaluation (ultrasonography, CT, and MRI) and/or biopsy within 4 weeks. Additional imaging was performed with 99mTc-(V)-DMSA, (131)I-metaiodobenzylguanidine, 201thallium chloride, 99mTc-methylene diphosphate, and/or 18F-fluorodeoxyglucose-positron emission tomography. Clinical follow-up was obtained. RESULTS: All patients with established disease had elevated plasma CEA (range, 6.8-345 ng/mL; calcitonin levels between 92 and 11,497 pg/mL), whereas in 9 of 14 occult cases, levels were < or = 5 ng/mL (range, 0.6-829 ng/mL; calcitonin, 72-2920 pg/mL). In patients with known disease, the overall lesion-based sensitivity was 86% for the anti-CEA MAbs, whereas octreotide was unable to target any tumor in patients with rapidly progressing disease or distant metastases (overall sensitivity, 47%). In all patients with occult MTC, anti-CEA MAbs and octreotide were able to localize at least one lesion (patient-based sensitivity, virtually 100%). In patients with postsurgically persistent hypercalcitoninemia, cervical lymph nodes were identified as the most frequent site of metastases, whereas in patients with occult and slowly progressing disease several years after primary surgery, anti-CEA MAbs and octreotide showed bilateral involvement of mediastinal lymph nodes; however, tumor to nontumor ratios were usually higher with octreotide in these cases. With anti-CEA Mabs, the highest tumor to nontumor ratios were observed in clinically aggressive, rapidly progressing disease. The sensitivity of all other diagnostic modalities was, at < or = 50%, significantly lower. Indication for antitumor effects was observed in a patient receiving 65 mCi of (111)I-labeled F(ab')2 fragments of the clone F023C5. CONCLUSIONS: For the detection of occult MTC, anti-CEA MAbs and octreotide seem to have a sensitivity that is superior to conventional diagnostic modalities, especially also when used in combination. Better detectability with anti-CEA antibodies (which may result in higher CEA expression) seems to be associated with more aggressively growing forms of MTC, whereas somatostatin receptor expression at normal CEA plasma levels and weaker MAb targeting may be associated with a more benign clinical course. This is in accordance with the study of Busnardo et al. (Cancer 1984; 53:278-85), who showed higher CEA serum levels to be associated with a worse prognosis, as well as with the in vitro findings of Reubi et al. (Lab Invest 1991;64:567-73), who demonstrated lower somatostatin receptor expression in less differentiated MTC. Fu

Adult↗