Search PubMed⌕ Search

Biomedical subjects

M Becker

Publications and source records attributed to M Becker.

At least 145 records · Page 8Linked to original sources
PubMed1997

Use of concurrent chemotherapy, accelerated fractionation radiation, and surgery for patients with esophageal carcinoma.

BACKGROUND: The results of a Phase II study of concurrent chemotherapy and accelerated fractionation radiation therapy followed by surgical resection for patients with both adenocarcinoma and squamous cell carcinoma of the esophagus are presented. Pretreatment and postinduction staging were correlated with pathologic findings at surgery to assess the role of surgical resection and the predictive value of noninvasive staging techniques. METHODS: Patients received 2 induction courses with 4-day continuous intravenous infusions of cisplatin (20 mg/m2/day) and 5-fluorouracil (1000 mg/m2/day) beginning on Day 1 and Day 21, concurrent with a split course of accelerated fractionation radiation (1.5 grays [Gy] twice daily, to a total dose of 45 Gy). All patients were subsequently referred for surgical resection. A single, identical postoperative course of chemotherapy and 24 Gy accelerated fractionation radiation was planned for patients with residual tumor at surgery. RESULTS: Seventy-four patients were entered on this study; 72 patients were considered eligible and evaluable. Induction toxicity included nausea (85%), increased dysphagia (90%), neutropenia (<1000/mm3) (43%), thrombocytopenia (<20,000/mm3) (10%), and reversible nephrotoxicity (8%). Sixty-seven patients (93%) underwent surgery, and 65 (90%) were found to have resectable tumors. Twelve of these patients (18%) died perioperatively, and 18 (27%) had no residual pathologic evidence of disease. Resolution of symptoms and normalization of radiographic studies, endoscopy, or esophageal ultrasound did not identify pathologic complete responders accurately. No patient completing induction therapy and surgery experienced a locoregional recurrence. The Kaplan-Meier 4-year projected recurrence free and overall survival rates were 49% and 44%, respectively. CONCLUSIONS: Although this regimen is feasible, there was significant preoperative toxicity and perioperative mortality. Nonetheless, the recurrence free and overall survival rates were encouraging. However, no staging tool can predict a pathologic complete response after induction therapy accurately, suggesting a continued need for surgical resection.

Adenocarcinoma↗
PubMed1997

Cloning and sequencing of ribosomal protein L27a and a gene similar to human GS1 in Drosophila.

Two closely linked genes were identified and characterized in the 24F region on the left arm of chromosome 2 in Drosophila. One cDNA predicts a protein of 231 amino acids, with a molecular mass of 25.7 kDa. The predicted amino-acid sequence of this protein is 47.2% identical to that of the previously reported human GS1 protein, which is encoded by a gene that is of interest because it is one of the few X-linked genes that escapes X-inactivation. We have accordingly named our gene GS1like (GS1l). The second cDNA begins 383 bp proximal to the first. This cDNA encodes a protein of a predicted 149 amino acids and a molecular mass of 17.0 kDa. This protein represents a homolog of ribosomal protein L27a; thus, we have named the gene RpL27a. This gene might be responsible for the Minute mutation located at 24F. An rpL27a gene was previously localized to 87F/88A; thus, this gene might be present in two locations in Drosophila.

Amino Acid Sequence↗
PubMed1997

Detection and characterization of phospholipase D by flow injection analysis.

A precisely working automated system for the investigation of phospholipases D (PLDs, EC 3.1.4.4) from plant and microbial sources with flow injection analysis (FIA) has been developed. The two versions of the FIA setup described are based on the oxidation of choline liberated from phosphatidylcholine by PLD action and catalyzed by choline oxidase and the chemiluminescence detection of hydrogen peroxide produced by this reaction. The correlation between this chemiluminescence signal and the PLD activity was linear in the range between 1 and 100 mU/ml PLD. The sampling frequency was 12 samples per hour. This method was used to compare three different PLDs from cabbage and microbial sources with respect to their pH optima, temperature stability, effectors, and v/[S]-characteristics.

Calcium↗
PubMed1997

Pretherapeutic staging of hypopharyngeal carcinoma. Clinical findings, computed tomography, and magnetic resonance imaging compared with histopathologic evaluation.

OBJECTIVES: To assess the accuracy of preoperative computed tomography (CT), magnetic resonance imaging (MRI), and clinical and endoscopic tumor evaluation and to analyze the impact of these diagnostic modalities on pretherapeutic staging of hypopharyngeal carcinoma. DESIGNS: Prospective study of 44 consecutive patients with hypopharyngeal carcinoma undergoing surgical resection. SETTING: Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Bern, Switzerland. METHODS: All patients underwent contrast-enhanced CT, MRI at 1.5 T, indirect laryngoscopy, and direct laryngoscopy. The surgical specimens were cut in whole-organ slices parallel to the plane of the axial CT and MRI scans. The histologic findings were compared with the findings of the different diagnostic modalities. RESULTS: The main tumor site was misdiagnosed by endoscopy in 7 (16%) of 44 patients and by CT and MRI in 16 (36%) of 44 patients. Neoplastic invasion of cartilage was present in 21 (48%) of 44 laryngectomy specimens. Magnetic resonance imaging was more sensitive in detecting neoplastic invasion of cartilage than CT (97% vs 68%; P = .002). Magnetic resonance imaging was less specific than CT (62% vs 84%; P = .02), taking into account the thyroid and cricoid cartilages. There was no difference between the overall accuracy of CT and MRI in detecting neoplastic invasion of cartilage (78% vs 75%). Clinical and endoscopic evaluation failed to correctly stage 16 (36%) of 44 patients. Combined clinical and CT evaluation and combined clinical and MRI evaluation failed to correctly stage 12 and 13 of 44 patients, respectively. CONCLUSIONS: The assessment of tumor site is more accurate using endoscopic evaluation than CT or MRI. Magnetic resonance imaging is more sensitive in detecting neoplastic cartilage invasion than CT, whereas CT is more specific. Clinical and endoscopic evaluation of tumor stage alone fails to identify invasion of the laryngeal framework. Therefore, many tumors staged pT4 are clinically understaged. The preoperative staging accuracy was improved by combining the information gained using both clinical evaluation and CT or MRI. However, there was no difference in the staging accuracy between CT and MRI.

Adult↗
PubMed1997

Staging of laryngeal cancer: endoscopy, computed tomography and magnetic resonance versus histopathology.

An accurate pretherapeutic staging of laryngeal cancer is required for optimal treatment planning and for evaluation and comparison of the results of different treatment modalities. In this study, 45 consecutive patients with neoplasms of the larynx, treated surgically, were included in a prospective pretherapeutic staging protocol that included indirect laryngoscopy, direct microlaryngoscopy, contrast-enhanced computed tomography (CT) and Gd-DTPA-enhanced magnetic resonance imaging (MRI). The surgical specimens were cut in whole-organ slices parallel to the plane of the axial CT and MR images. The histologic findings were then compared with clinical findings, CT and MRI. These findings showed that clinical evaluation failed to identify tumor invasion of the laryngeal cartilages and extralaryngeal soft tissues, resulting in a low staging accuracy (55%). Many pT4 tumors were clinically understaged. The combination of clinical/endoscopic evaluation and either CT or MRI resulted in a significantly improved staging accuracy (80% vs 87%, respectively). MRI was significantly more sensitive but less specific than CT in detecting neoplastic cartilage invasion. MRI tended to overestimate neoplastic cartilage invasion to possibly result in overtreatment, while CT was found to underestimate neoplastic cartilage invasion and could lead to inadequate therapeutic decisions.

Adult↗
PubMed1997

In vitro release of eosinophil cationic protein from peripheral eosinophils reflects disease activity in childhood Crohn disease and ulcerative colitis.

UNLABELLED: The aim of this study was to compare in vitro release of eosinophil cationic protein (ECP) from peripheral blood eosinophils during active phases of childhood Crohn disease (CD) and ulcerative colitis with phases of remission. Ten children with CD and nine children with ulcerative colitis were investigated during 55 and 56 clinical visits, respectively. Each patient was investigated during at least one phase of clinically active disease and one phase of remission. Disease activity was assessed by means of the Paediatric Crohn Disease Activity Index (PCDAI) in Crohn disease and according to the clinical activity index of Rachmilewitz in ulcerative colitis. On an intra-individual basis, in vitro ECP release was significantly higher (P < 0.001) during active phases of CD and ulcerative colitis than in phases of remission (CD:median: 24.5 microg/l, range 16.0-61.2 versus median: 5.7 microg/l, range 2.0-16.7; ulcerative colitis: 14.8 microg/l, 8.3-39.8 versus 4.9 microg/l, 2.0-9.9). On an inte-individual basis, in CD and ulcerative colitis a strong and highly significant correlation was observed between disease activity indices and in vitro release of ECP from peripheral eosinophils (r = 0.89, P < 0.0001 and r = 0.82, P < 0.0001, respectively). CONCLUSION: These results show that in vitro ECP release from peripheral eosinophils reflects disease activity in both CD and ulcerative colitis and therefore can be used as a new appropriate laboratory parameter for assessment of disease activity in chronic inflammatory bowel disease.

Adolescent↗
PubMed1997

Immediate function of temporomandibular joint after total resection and reconstruction.

Two patients with recurrent parotid gland carcinoma required subtotal petrosectomy and infratemporal fossa type C approach. To achieve en bloc resection, the ascending mandibular ramus and the entire temporomandibular joint, including the adjacent temporal bone, were removed. An original technique for immediate reconstruction of the infratemporal region, including the glenoid fossa and the ramus of the mandible, is described. Rigid fixation, as well as good functional and aesthetic results, was achieved with autologous calvarial bone and full-thickness rib grafts, allowing the patients to mobilize their jaw very rapidly.

Adenocarcinoma↗
PubMed1997

Effects of amifostine (WR-2721, ethyol) on tumor growth and pharmacology of cytotoxic drugs in human xenotransplanted neuroblastomas.

Amifostine was developed as a radio- and chemoprotective agent. It has shown protection against whole-body irradiation, and myelo- and nephrotoxicity of cytotoxic agents both in experimental and clinical studies. Some experimental trials revealed an influence of amifostine on tumor growth or the activity of cytotoxic drugs under certain circumstances. Therefore, it was the aim of our work to evaluate the pharmacological potential of amifostine in a preclinical in vivo situation with human xenotransplanted neuroblastomas. Human neuroblastoma cells (IMR5-75 and Kelly) were grown s.c. as xenografts in nude mice to palpable sizes (approximately 4 x 5 mm). Then the animals received 200 mg/kg amifostine i.p. and were treated 30 min later with one of the following cytotoxic drugs: cyclophosphamide, doxorubicin, cisplatin, ifosfamide, vincristine and etoposide. Amifostine as the only treatment did not influence the growth of the neuroblastomas IMR5-75 and Kelly. We observed no side effects of the compound itself. In no case did amifostine interact significantly with the antitumor effect of any cytostatic used in combination. However, amifostine mitigated the body weight loss induced by vicristine and the leukopenia induced by cyclophosphamide, cisplatin or ifosfamide, respectively. The side effects of the remaining cytostatics were--if observed at all--unchanged. We conclude that amifostine did not influence the tumor growth of xenotransplanted neuroblastomas and did not reduce the antineoplastic activity of the tested cytostatic drugs. Further investigation of amifostine as a protectant from side effects of chemotherapy in a clinical setting is warranted.

Amifostine↗
PubMed1997

Assessing medical students' perceptions of mistreatment in their second and third years.

PURPOSE: To study medical students' perceptions of mistreatment in their second and third years of training. METHOD: A questionnaire was distributed at Wayne State University School of Medicine to the class of 1993 at the end of its third year and to the class of 1994 at the end of its second and third years. The students were asked if they had been subjected to various forms of mistreatment; the third-year students were asked to rate their perceptions of each clinical department's response to them on the basis of gender and race-ethnicity, as well as their overall treatment. The students also completed demographic information about age, gender, and marital status, number of children, and race-ethnicity. Results were analyzed using chi-square statistics, multivariate statistical analyses, analyses of variance, and Duncan's post-hoc comparisons. RESULTS: The response rate for the class of 1993 was 71.5%; response for the class of 1994 were 66.9% in their second year and 75.2% in their third year; 41.7% were women, and the racial-ethnic breakdown was 71.2% white/Caucasian, 11.7% black/African American and 16.8% other. There was a significant difference between the percentages of second-year and third-year students reporting any experience of mistreatment (37.2% vs 75.8%, p < .001). Canonical correlation analysis revealed bias in the third year based on gender (p < .0001) and race-ethnicity (p < .0002); both variates were related to sexual humor. The students' perceptions of mistreatment were lowest for family medicine and highest for obstetrics-gynecology and surgery. Perceptions of mistreatment in departments varied significantly by gender and race-ethnicity. The nonwhite males reported the least favorable treatment in most departments. CONCLUSION: Marked variability in the students' perceptions of mistreatment within departments suggest that a variety of approaches will be required to improve the medical training environment.

Education, Medical, Undergraduate↗
PubMed1997

Prevalence of Helicobacter pylori infection in Nicaraguan children with persistent diarrhea, diagnosed by the 13C-urea breath test.

BACKGROUND: The impairment of gastric acid barrier caused by Helicobacter pylori (H. pylori) at the onset of infection may predispose to small bowel bacterial overgrowth, which could contribute to persistent diarrhea. METHODS: Using the 13C-urea breath test, we determined the prevalence of H. pylori infection in 123 Nicaraguan children from Tipitapa, aged 1 to 65 months, from a low socioeconomic background. RESULTS: The overall prevalence of H. pylori infection was 77.2% (95/123). The prevalence varied with age and was significantly (p < 0.001) higher in infants < or = 12 months than in children aged 13-65 months, 91% (57/63) as against 63% (38/60). H. pylori infection was present in 44 of 59 (75%) children suffering from persistent diarrhea compared with 51 of 64 (80%) age-matched asymptomatic controls. In the diarrheal group, 20 of 59 (34%) children presented with malnutrition, and 16 (80%) of them showed H. pylori infection. In the control group, 20 of 64 (31%) were malnourished, and 14 (70%) of them showed H. pylori infection. CONCLUSIONS: In Nicaragua, H. pylori is acquired in early infancy. The high prevalence among children in the first 12 months of life and the lower infection rate between 1 and 5 years of age suggest a loss or clearance of infection, also an occasional finding in adults. H. pylori infection appears to be not a risk factor for persistent diarrhea or malnutrition in Nicaraguan children.

Age Factors↗
PubMed1997

Replantation of the complete external genitals.

Most cases of genital amputation represent an isolated penile amputation; the combined amputation of both penile and testes is reported very seldom. We describe a case of complete amputation of the external genitals with successful replantation and good functional outcome. The problem is analyzed with respect to operative strategy, ischemic periods, postoperative management, and psychiatric background. For the replantation of the testes, time frames are comparable to those for macroreplantations.

Adult↗
PubMed1997

The fasciocutaneous supraclavicular artery island flap for releasing postburn mentosternal contractures.

Mentosternal contractures represent a surgical challenge to the plastic and reconstructive surgeon. We add the supraclavicular artery island flap to the armamentarium of surgical procedures to improve the function and cosmesis of disfigured patients. Since July of 1994, the supraclavicular artery island flap has been used at our institution for releasing postburn mentosternal contractures in eight patients. The flap was planned to be 4 to 10 cm in width and 20 to 30 cm in length with the supraclavicular vessels running axially. All donor defects could be closed primarily without significant postoperative complications in seven of the eight patients. All flaps healed primarily, achieving a good functional result by complete removal of contracting scar tissue for all patients; one donor site healed by secondary intention. We found the supraclavicular artery island flap both reliable and safe for immediate resurfacing after resection of cervical scars. The anatomy, operative procedure, and postoperative results of the supraclavicular artery island flap are outlined in this paper.

Adult↗
PubMed1997

Scanning laser fundus perimetry before laser photocoagulation of well defined choroidal neovascularisation.

AIM: To assess the centre of fixation before laser photocoagulation of well defined juxtafoveal or extrafoveal choroidal neovascularisation (CNV) secondary to age related macular degeneration (AMD), and to better predict visual function after treatment using scanning laser ophthalmoscope (SLO) fundus perimetry. METHODS: 19 consecutive eyes with juxtafoveal or extrafoveal CNV were examined by fundus perimetry before and after laser treatment with documentation of the fixation point using the SLO. The stability of fixation was defined as standard deviation around the mean fixation point. Overlays of fluorescein angiographic pictures and fundus perimetry were obtained using image analysis software. RESULTS: Fundus perimetry allowed accurate determination of the centre of fixation. Overlays demonstrated the precise geographic relation of the angiographically detectable foveal margin of the CNV and the centre of fixation. Thereby, prediction of the visual outcome with regard to reading ability was facilitated. Stability of fixation did not change significantly after treatment. CONCLUSIONS: Fundus perimetry using the SLO was helpful in patients who underwent laser treatment for juxtafoveal or extrafoveal CNV secondary to AMD and may aid the pretreatment counselling of such patients.

Aged↗
PubMed1997

Necrotizing fasciitis of the head and neck: role of CT in diagnosis and management.

PURPOSE: To determine the characteristic diagnostic features of necrotizing fasciitis and to evaluate the role of computed tomography (CT) in its management. MATERIALS AND METHODS: Fourteen patients with surgically proved necrotizing fasciitis of the extracranial head and neck were examined with contrast material-enhanced CT. Clinical, radiologic, surgical, pathologic, and anatomic findings at admission and after initial treatment were analyzed retrospectively. RESULTS: Constant CT features of necrotizing fasciitis were diffuse thickening and infiltration of the cutis and subcutis (cellulitis); diffuse enhancement and/or thickening of the superficial and deep cervical fasciae (fasciitis); enhancement and thickening of the platysma, sternocleidomastoid muscle, or strap muscles (myositis); and fluid collections in multiple neck compartments. Inconstant CT features included gas collections, mediastinitis, and pleural or pericardial effusions. All patients underwent extensive surgical debridement. Follow-up CT scans in 11 patients revealed clinically unsuspected progression of the inflammatory process in previously unaffected areas, a finding that warranted additional surgery in nine patients. Twelve patients survived, and two patients died of septic shock and aspiration pneumonia despite intensive surgical and medical treatment. CONCLUSION: Early recognition of necrotizing fasciitis with CT enables appropriate surgical treatment. CT may also be a useful guide in further patient treatment after initial surgical debridement.

Adolescent↗