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Biomedical subjects

M Becker

Publications and source records attributed to M Becker.

At least 163 records · Page 9Linked to original sources
PubMed1997

Neoplastic invasion of the laryngeal cartilage: reassessment of criteria for diagnosis at CT.

PURPOSE: To evaluate eight different diagnostic criteria to help detect neoplastic invasion of laryngeal cartilage at computed tomography (CT). MATERIALS AND METHODS: In a prospective series, 111 patients with carcinoma of the larynx or hypopharynx underwent thin-section, contrast material-enhanced CT before total or partial laryngectomy. The following CT criteria were evaluated: extralaryngeal tumor, sclerosis, tumor adjacent to nonossified cartilage, serpiginous contour, erosion or lysis, obliteration of marrow space, cartilaginous blowout, and bowing. Histologic findings were correlated with findings on CT scans obtained at each level. RESULTS: Histologically, 122 of 412 cartilages were invaded. Depending on the diagnostic criteria and each specific cartilage, there was great variation in sensitivity (7%-83%) and specificity (40%-100%). Sclerosis was the most sensitive criteria in all cartilages but often corresponded to reactive inflammation in the thyroid cartilage. Extralaryngeal tumor and erosion or lysis yielded the highest specificity. Tumor adjacent to nonossified cartilage, serpiginous contour, and obliteration of marrow space were specific although not sensitive signs of invasion in the arytenoid and cricoid cartilage and were nonspecific in the thyroid cartilage. Blowout and bowing were not useful. Selection of the appropriate combination of criteria enabled an overall sensitivity of 91% (associated specificity, 68%) or an overall specificity of 79% (associated sensitivity, 82%). CONCLUSION: Detection of neoplastic cartilage invasion with CT greatly depended on the appropriate use of individual and combined CT criteria.

Adult↗
PubMed1997

Choledocholithiasis and bile duct stenosis: diagnostic accuracy of MR cholangiopancreatography.

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) cholangiopancreatography for detecting bile duct calculi and stenosis. MATERIALS AND METHODS: At MR cholangiopancreatography, 108 patients suspected of having bile duct calculi or stenosis were examined with two-dimensional fast spin-echo MR sequences and respiratory gating. On the basis of findings at surgery and/or intraoperative, endoscopic retrograde, and/or percutaneous cholangiography, final diagnoses were normal bile ducts (n = 38), choledocholithiasis (n = 23), Mirizzi syndrome (n = 3), benign or malignant bile duct stenosis (n = 40), choledochal cyst (n = 1), and bile duct dilatation without calculi or stenosis (n = 3). MR cholangiopancreatographic images were analyzed retrospectively by three reviewers who were unaware of final diagnoses. RESULTS: Choledocholithiasis was diagnosed with a sensitivity of 88%-92% and a specificity of 91%-98%. False-negative readings occurred because small or impacted calculi at the distal common bile duct or ampulla were difficult to detect or distinguish from stenosis. Bile duct stenosis was diagnosed with a sensitivity of 93%-100% and a specificity of 98%. Presence or absence of bile duct abnormality was assessed with a sensitivity of 97%-99% and a specificity of 95%-97%. Interobserver agreement was very good (kappa = 0.86-0.96). CONCLUSION: With MR cholangiopancreatography, bile duct calculi and stenoses can be diagnosed with high accuracy and good interobserver agreement.

Adult↗
PubMed1997

Attitudes of physical therapists who possess sports specialist certification.

Physical therapists contemplating sports specialist certification need research-based information to facilitate their decision-making process. The purpose of this study was to investigate the attitudes of physical therapists who have received sports specialist certification. These attitudes encompass the physical therapists' sense of fulfillment and their feelings of satisfaction or dissatisfaction with the certification process. Factors contributing to the therapist's decision to become sports specialist certified have also been investigated. Physical therapists who are sports certified specialists (N = 110) participated in this study. Questionnaires were mailed to the entire population of physical therapists who are sports certified specialists (N = 148). Frequency distributions and percentages were used on qualitative data, and mode was calculated for quantitative data. One hundred ten surveys were returned, for a response rate of 74.3%. Analysis of responses from the subject group suggests that physical therapists feel a high level of satisfaction with their decision to specialize, and that continued professional growth, development, and personal achievement are the major contributing factors in their decision to specialize. Based on these findings, physical therapists appeared to display overall satisfaction in their attitudes toward sports specialist certification. Further research may be warranted to further examine sports certified therapists' attitudes toward the specialization process.

Adult↗
PubMed1997

Timing of free microsurgical tissue transfer for the acute phase of hand injuries.

Because of favourable survival rates in replantation surgery and a high standard of free tissue transfer the interval between injury and microsurgical reconstruction has become gradually shorter. The acute phase can be defined as the interval ranging from emergency procedures within 24 hours to urgent procedures done within 72 hours. Bearing in mind the infection rates that have been reported of 1.5% for the acute phase and 17.5% for the late phase, we should encourage emergency reconstructions. However, in most cases of upper extremity injuries, reconstruction with conventional flaps is possible. Between 1981 and 1995 we did 72 acute post-traumatic free tissue transfers to the upper extremity in our unit within 72 hours (urgently). There were no significant differences in the incidence of infections when acute were compared with urgent procedures. As a result we support the concept of urgent operations. The following advantages are to be considered: urgent operations allow a second look operation, the viability of the extremity can be assessed, and the reconstructive procedure can be planned more precisely. Last but not least, the procedure is done during the day time with better operating conditions.

Hand Injuries↗
PubMed1997

Liver transplantation: treatment of choice for hepatic and neurological manifestation of Wilson's disease.

Liver transplantation (LTX) is an approved method to treat patients with end-stage liver cirrhosis and acute liver failure due to Wilson's disease. Initially, there was some consideration about the indication for LTX in the case of Wilson's disease with severe neurological impairment but normal liver function. From 1988 until 1995, 13 out of 700 LTX (1.9%) were performed for Wilson's disease. Indications for LTX were (I) intractable neurological impairment with normal liver function (n = 4; including one patient with Child A cirrhosis), (II) fulminant hepatic failure (n = 3), and (III) end-stage liver cirrhosis (n = 6) (Child B, n = 1; Child C, n = 5). There were 8 females and 5 males with a mean age of 27 yr (range 15-34 yr). All patients of group I required continuous nursing care before LTX, in spite of pretreatment with d-penicillamine and zinc. The most frequent symptoms in these patients were dysphagia (n = 4), dysarthria (n = 4), tremor (n = 4), sialorrhea (n = 3), ataxia (n = 3), dystonia (n = 3) and handwriting difficulties (n = 3). All patients of group II presented with hemolytic anemia. The survival rate was 100%, and all patients were doing well after a mean follow-up period of 32.8 months (range 8-68 months). The postoperative course was without severe infectious and other complications. All patients of group I revealed the first signs of improvement for all types of neurological symptoms 4-6 wk after LTX. One patient has been without any symptoms from 18 months until 5.5 yr after LTX. Two patients with short-term follow-up also had noticeable improvement of neurological impairment, but residual symptoms are still present. One patient showed only slight improvement. We conclude that Wilson's disease may be a good indication for LTX for both neurological manifestation with stable liver function and hepatic manifestation with cirrhosis or acute liver failure.

Adolescent↗
PubMed1996

A neurotransmitter transporter encoded by the Drosophila inebriated gene.

Behavioral and electrophysiological studies on mutants defective in the Drosophila inebriated (ine) gene demonstrated increased excitability of the motor neuron. In this paper, we describe the cloning and sequence analysis of ine. Mutations in ine were localized on cloned DNA by restriction mapping and restriction fragment length polymorphism (RFLP) mapping of ine mutants. DNA from the ine region was then used to isolate an ine cDNA. In situ hybridization of ine transcripts to developing embryos revealed expression of this gene in several cell types, including the posterior hindgut, Malpighian tubules, anal plate, garland cells, and a subset of cells in the central nervous system. The ine cDNA contains an open reading frame of 658 amino acids with a high degree of sequence similarity to members of the Na+/Cl(-)-dependent neurotransmitter transporter family. Members of this family catalyze the rapid reuptake of neurotransmitters released into the synapse and thereby play key roles in controlling neuronal function. We conclude that ine mutations cause increased excitability of the Drosophila motor neuron by causing the defective reuptake of the substrate neurotransmitter of the ine transporter and thus overstimulation of the motor neuron by this neurotransmitter. From this observation comes a unique opportunity to perform a genetic dissection of the regulation of excitability of the Drosophila motor neuron.

Amino Acid Sequence↗
PubMed1996

Stimulation of GLUT1 glucose transporter expression in response to inhibition of oxidative phosphorylation: role of reduced sulfhydryl groups.

Treatment of Clone 9 cells incubated in the absence of serum with 5 mM azide for 24 h results in an 8- and 3-fold induction in GLUT1 mRNA and GLUT1 protein, respectively. To explore the pathways mediating the induction of GLUT1 mRNA, we first examined whether inhibition of oxidative phosphorylation by other agents results to a similar response. Exposure of cells to 5 microM carbonyl cyanide m-chlorophenylhydrazone (CCCP), 0.15 microM oligomycin B, or 5 mM azide resulted in near-equivalent increases in GLUT1 mRNA content. The inhibition of oxidative phosphorylation is associated with increased cell lactate content and in extracellular lactate to pyruvate ratio, reflecting a rise in cytosolic NADH/NAD+ ratio. We next tested the possibility that an increase in cell SH/SS ratio mediates the enhancement of GLUT1 mRNA in response to azide. We show that treatment of cells with 10 mM mercaptoethanol, an agent that increases cell SH/SS ratio, results in a approximately 6-fold increase in GLUT1 mRNA content. Moreover, incubation of cells in the presence of 0.3 mM diamide, a known intracellular sulfhydryl oxidizing agent, completely abolishes the induction of GLUT1 mRNA by azide. The results suggest that an increase in cell SH/SS ratio plays a critical role in the induction of GLUT1 mRNA in response to inhibition of oxidative phosphorylation.

Animals↗
PubMed1996

Pretherapeutic staging of laryngeal carcinoma. Clinical findings, computed tomography, and magnetic resonance imaging compared with histopathology.

BACKGROUND: An accurate pretherapeutic staging of laryngeal carcinoma is required for most treatment planning as well as for evaluation and comparison of the results of different treatment modalities. Neoplastic invasion of the laryngeal cartilage may have important therapeutic implications. To our knowledge, no data are available comparing the impact of endoscopic examination, computed tomography (CT), and magnetic resonance (MR) imaging on pretherapeutic staging accuracy. The purpose of our study was to determine which imaging should be used as an adjunct to other clinical examinations in the pretherapeutic staging of laryngeal carcinoma. METHODS: In this study, 40 consecutive patients with neoplasms of the larynx, who were treated surgically, were included in a prospective pretherapeutic staging protocol that included indirect laryngoscopy, direct microlaryngoscopy, contrast-enhanced CT, and gadolinium-diethylenetriamine pentaacetic acid-enhanced MR imaging at 1.5 Tesla. The surgical specimens were cut in whole-organ slices parallel to the plane of the axial CT and MR images. The histologic findings were compared with the clinical findings including the CT and MR images. The impact of each diagnostic method on pretherapeutic staging was analyzed. RESULTS: Clinical/endoscopic evaluation failed to correctly stage 17 tumors due to invasion of the paraglottic space (1 tumor), preepiglottic space (2 tumors), and extralaryngeal soft tissues (14 tumors), resulting in a pretherapeutic staging accuracy of 57.5%. Neoplastic invasion of cartilage was present in 28 patients and absent in 12 patients. Although MR imaging was more sensitive in detecting neoplastic invasion of cartilage than CT (94% vs. 67%; P = 0.001), MR imaging was less specific than CT (74% vs. 87%; P = 0.007). There was no difference between the overall accuracy of CT and MR imaging in detecting neoplastic invasion of cartilage (80% vs. 82%). The accuracy of combined clinical/endoscopic examination and CT staging was 80% and the accuracy of combined clinical/endoscopic examination and MR imaging staging was 87.5%; the difference was not statistically significant. CONCLUSIONS: Clinical/endoscopic examination alone failed to identify tumor invasion of the laryngeal cartilages and of the extralaryngeal soft tissues, resulting in a low staging accuracy (57.5%). Many pT4 (according to the International Union against Cancer TNM Staging System) tumors were clinically unrecognized. The combination of clinical/endoscopic evaluation and an additional radiologic examination, either CT or MR imaging, resulted in significantly improved staging accuracy (80% vs. 87.5%). MR imaging is significantly more sensitive but less specific than CT in detecting neoplastic cartilage invasion. Therefore, MR imaging tends to overestimate neoplastic cartilage invasion and may result in overtreatment, whereas CT tends to underestimate neoplastic cartilage invasion and may lead to inadequate therapy.

Adult↗
PubMed1996

[Palliative surgical treatment of bone metastases. Improved quality of life by early intervention?].

OBJECTIVE: To find out to what extent early operative treatment of osteolysis or pathological fractures, resulting from improved interdisciplinary treatment of malignant tumours, affects quality of life. PATIENTS AND METHOD: Using a standardised scheme of self-evaluation in a retrospective study, quality of life was assessed in 67 patients (18 men, 49 women; mean age 64.5 +/- 11.6 years) who were operated for osteolyses or pathological limb fractures due to malignant tumour metastases. RESULTS: Interlocking osteosynthesis was performed in 37 patients, endoprosthetic joint replacement in 30. Duration of operation and hospital stay were significantly shorter in those 17 patients operated for osteolysis than those 50 patients with a pathological fracture (P < 0.01 and P < 0.07, respectively). There were seven hospital deaths. Postoperative survival time averaged 13.4 months. 41 of the 60 patients discharged to outpatient follow-up were again capable of leading a normal life, 13 were clearly impaired, six required nursing care, 46 patients did not or only sporadically require analgesics postoperatively. CONCLUSION: Early operative treatment of osteolysis before the occurrence of fractures is justified by the low operative mortality and complication rates and the better quality of life that is achieved.

Aged↗
PubMed1996

Technetium-99m human immunoglobulin (HIG): a new substance for scintigraphic detection of bone and joint infections.

Technetium (99m-Tc)-labelled, polyclonal human immunoglobulin (HIG) has been described as a new agent to detect local infection and inflammation. In this study, we tested 99m-Tc HIG in 55 patients with suspected chronic (n = 42) and acute (n = 13) skeletal infection. Diagnosis was proven operatively (n = 44) and clinically (n = 11), including microbiological culture tests (n = 46). A gamma camera scan was performed 4 and 24 hours after I.v. injection of 500 MBq 99m-Tc-HIG. 99m-Tc-HIG scanning achieved a sensitivity of 91% and a specificity of 93%. We found one false negative and five false positive scintigraphic results in 55 patients. No clinical or biochemical side effects were encountered after 99m-Tc-HIG injection. We recommend this technique especially for localisation of low-grade, chronic osteomyelitis. The mechanisms and kinetics of 99m-Tc-HIG, however, are worth investigating more extensively.

Acute Disease↗
PubMed1996

Impact of cartilage invasion on treatment and prognosis of laryngeal cancer.

Invasion of laryngeal cartilage has long been considered as a contraindication to radiation treatment and to all types of conservation surgery. With the advent of axial imaging techniques clarification of the submucosal extent of disease became possible. However, controversies regarding diagnosis (preferred modality, accuracy of detection of cartilage invasion) and treatment of cartilage invasion (Is cartilage invasion really a contraindication for irradiation treatment?) arose. Based on currently accepted criteria, CT appears to be more specific in detecting neoplastic cartilage invasion than MRI, but tends to underestimate invasion and may therefore result in undertreatment. Magnetic resonance has a higher sensitivity than CT for detection of cartilage invasion. The superiority of MRI lies in its ability to detect intracartilaginous tumor spread. Unfortunately, MR findings suggesting neoplastic cartilage invasion may be false positive in a considerable number of instances. Two MRI-dependent parameters appear to be significant as a prognostic factor for success of radiation therapy: tumor volume and abnormal MR signal pattern in cartilage. Minimal abnormal MR signal patterns in cartilage in patients with small tumors (under 5 cc) does not appear to be a very ominous finding for tumor recurrence after radiation therapy. On the other hand, abnormal MR signal pattern in cartilage combined with large tumor volume (above 5 cc) appears to worsen the prognosis significantly. If voice conservation surgery is being considered, MR imaging is useful for assessing those structures (such as cartilages) whose involvement would contraindicate partial laryngectomy. Magnetic resonance imaging appears to be the optimal method of examination in cooperative patients. If MRI fails or if it is contra-indicated, CT may still be recommended. The radiologist's experience with CT or MRI also determines the choice between the two modalities.

Contraindications↗
PubMed1996

Elevated serum aminoterminal procollagen type-III-peptide parallels collagen accumulation in rats with secondary biliary fibrosis.

BACKGROUND/AIMS: The aminoterminal procollagen type-III-peptide, which can be released during collagen type III deposition, has been suggested as a serum marker of fibrogenesis in patients with chronic liver disease. However, longitudinal studies correlating procollagen type-III-peptide concentrations in serum with the evolution of liver fibrosis are still needed. The purpose of the present study was to prove the significance of procollagen type-III-peptide concentrations in serum as a non-invasive marker of liver fibrogenesis in an animal model that best resembles progressive human liver fibrosis. METHODS: In 88 female Wistar rats the biliary system was occluded by double ligation of the choledochal duct followed by retrograde injection of a mixture of prolamine/ethanole (Ethibloc). Sixteen rats served as controls. Groups of 8-10 rats were sacrificed at days 2, 7, 14, 21, 30, 32, 35, 60 and 90 after bile duct occlusion. In the groups histological staging (fibrosis score), determination of total liver hydroxyproline, measurement of serum procollagen type-III-peptide and routine liver function tests were performed. RESULTS: First histological signs of liver fibrosis were seen as early as 7 days after bile duct occlusion. Progressive fibrosis was paralleled by an increase of serum procollagen type-III-peptide. There was a significant correlation between serum procollagen type-III-peptide and histological stages of fibrosis (r = 0.80; p < 0.0001) as well as between serum procollagen type-III-peptide and hydroxyproline in total liver tissue (r = 0.85; p < 0.0001) CONCLUSIONS: These results indicate that: (1) complete bile duct occlusion in rats produces progressive hepatic fibrosis resembling human secondary biliary fibrosis, and (2) procollagen type-III-peptide concentrations in serum reflect ongoing collagen formation in the liver unrelated to serum markers of cholestasis and inflammation.

Animals↗
PubMed1996

Changing the way we practice: how to thrive and not just survive in veterinary medicine.

Today's veterinarians face unprecedented competition such as veterinary clinics on every corner; hobby veterinarians who "give it away;" human pharmacies promoting do-it-yourself pet vaccinations; and corporate megastores with sophisticated management, overpowering marketing, and veterinary wellness clinics. Many veterinarians are experiencing flat or decreasing practice growth and are facing a severe financial squeeze. So, what's the answer? Give up? Take whatever comes? Accept less? Swing blindly at the problems? Remain blinded to the opportunities? No! We have got to fight back "to win" with better skills, increased attention to detail, and the sense-of-urgency that comes from being threatened! Start "competing to win" by building on our traditional strengths with the latest tools! This article offers a look forward at the demographics, trends, problems, and opportunities that face veterinarians in these ultracompetitive, fast-changing, yet opportunity-laden times. It's your choice--"To Thrive Or To Survive." This article shares the ideas, principles, emotions and winning tactics used by the great achievers in veterinary medicine. These are not anecdotal "pie-in-the-sky" schemes. These are proven "in-the-trenches" techniques and systems that have helped craft several million dollar practices. Follow the leaders!

Animals↗
PubMed1996

Generation and analysis of 280,000 human expressed sequence tags.

We report the generation of 319,311 single-pass sequencing reactions (known as expressed sequence tags, or ESTs) obtained from the 5' and 3' ends of 194,031 human cDNA clones. Our goal has been to obtain tag sequences from many different genes and to deposit these in the publicly accessible Data Base for Expressed Sequence Tags. Highly efficient automatic screening of the data allows deposition of the annotated sequences without delay. Sequences have been generated from 26 oligo(dT) primed directionally cloned libraries, of which 18 were normalized. The libraries were constructed using mRNA isolated from 17 different tissues representing three developmental states. Comparisons of a subset of our data with nonredundant human mRNA and protein data bases show that the ESTs represent many known sequences and contain many that are novel. Analysis of protein families using Hidden Markov Models confirms this observation and supports the contention that although normalization reduces significantly the relative abundance of redundant cDNA clones, it does not result in the complete removal of members of gene families.

Adult↗