PubMed Health⌕ Search

Biomedical subjects

C Becker

Publications and source records attributed to C Becker.

At least 199 records · Page 11Linked to original sources
PubMed2000

[CT-assisted volumetry and densitometry of distraction osteogenesis lengthened mandibular areas].

Gradual callus distraction in the correction of hypoplastic areas in the viscerocranial skeleton is an established method due to its efficacy. Whereas functional and esthetical improvements can be seen easily, it is impossible to get the increase of the bony mass right using the distractor scale or by clinical investigation. Only in animal studies can volumetric and densitometric measurements be done directly. By permission of the local ethics commission, in a clinical study, CT data of 24 children (12 unilateral and bilateral hypoplasias each) taken before and after mandibular distraction osteogenesis were used to get information on the amount of created bone and the grade of ossification of the callus at the time of the distractor removal. The CT data were prepared for computer evaluation using software which had been especially developed for this investigation. The quality of the investigation was influenced by disturbed data acquisition (insufficient sedation, Gantry deviation, different axial cuts). Therefore, the estimation of the real increase of bone was not possible, but all in all an increase of the volume could be seen. Using a grey scale analysis, the grade of new bone ossification was over 90% at the time of distractor removal. In our opinion, these results argue against the use of CT scans for the validation of a mandibular distraction. The estimation of the volume is very imprecise, the grade of ossification of the new bone very constant.

Absorptiometry, Photon↗
PubMed2000

[Diagnostic imaging in cardiac diagnosis].

PURPOSE: Cardiac imaging includes determination of the size and structure of the cardiac chambers, valves, great vessels and the coronary arteries, chamber and valvular function, myocardial perfusion, viability and metabolism. MATERIAL AND METHODS: Chest roentgenography, angiography, echocardiography and nuclear imaging are commonly used but computed tomography and magnetic resonance imaging also offer a promising potential. RESULTS: Coronary angiography is the gold standard in assessing coronary anatomy. Fast CT technologies such as electron-beam and multi-low-CT are promising non-invasive imaging modalities in the assessment of coronary artery disease. With intravascular ultrasound early stages of coronary atherosclerosis can be detected. For the assessment of myocardial perfusion and viability as well as cardiac function, scintigraphic methods are widely accepted. However, MRI methods have also reached a high degree of accuracy. Evaluation of chamber and valvular function is, due to its wide availability, the field of echocardiography. CONCLUSIONS: In clinical routine chest roentgenography, angiography, echocardiography and nuclear imaging are well established. The value of computed tomography and magnetic resonance imaging in the evaluation of coronary artery disease, myocardial perfusion, viability and metabolism is yet to be defined.

Coronary Disease↗
PubMed2000

[Cardiac imaging with rapid, retrospective ECG synchronized multilevel spiral CT].

PURPOSE: In this paper a method for cardiac imaging with fast multi-slice CT and retrospectively ECG-gated spiral acquisition is presented. METHODS: A fast multi-slice CT system with 4 simultaneously acquired slices and 0.5 s rotation time is used (Siemens Somatom VolumeZoom). Continuous spiral data of the entire heart volume is acquired together with the patient's ECG and reconstructed with dedicated spiral algorithms providing 250 ms temporal resolution. Three-dimensional image data sets are built up from overlapping slices that are reconstructed in an arbitrary, user-defined phase of the heart cycle (e.g. diastolic phase). To evaluate the capability of the method for functional imaging complete three-dimensional image volumes are reconstructed from the same spiral data set in different phases of the heart cycle. RESULTS: A spiral data set of the entire heart volume may be acquired within a single breath-hold. Typical scan times for standard examinations with 3 mm slice width are 10-15 s, and for high-resolution CT angiographies of the coronary arteries with 1.25 mm slice width about 30-35 s. Motion-free reconstruction of the heart and coronary arteries with high spatial resolution is possible in the diastolic phase of the heart cycle. Multi-phase reconstructions from the same spiral scan data set are possible, however, motion artifacts in heart phases with fast cardiac motion may not be completely avoided. CONCLUSION: Fast multi-slice spiral CT with retrospectively ECG-gated spiral reconstruction is well suited for three-dimensional and functional imaging of the heart, especially for high-resolution imaging of calcified coronary plaques and CT-angiography of the coronary arteries.

Algorithms↗
PubMed2000

Treatment of arterial hypertension with diuretics, beta- and calcium channel blockers in old patients.

Hypertension increases in prevalence with age. Population based studies suggest that more than 50% of people over the age of 65 years may have chronic hypertension. Hypertension, especially systolic hypertension, is the single most common, powerful, however, treatable risk factor for cardiovascular morbidity and mortality in the elderly. In order to assess the effectiveness of antihypertensive drug therapy among the elderly, with diuretics, beta-blockers and calcium channel blockers, a literature search was performed at the Cochrane Library, Medline and Excerpta medica. The Cochrane Hypertension Group identified 14 randomised controlled trials of at least one year duration with 21,785 elderly subjects where diuretics, beta-blockers or calcium channel blockers were used in the treatment group as first line drugs. In their meta-analysis (including one small trial with a central acting antiadrenergic drug) there was a decrease in total mortality (111 vs 129 deaths) and cardiovascular morbidity and mortality (126 vs 177 events) within the treatment group. The three trials restricted to persons with isolated systolic hypertension indicated beneficial effects in the treatment group with regard to cardiovascular morbidity and mortality (104 vs 157 events). Trial data on adverse effects is limited. In three studies, where adverse effects were reported, no substantial differences between treatment and control groups in measures of physical, cognitive and emotional function were found. Cardiovascular benefits of treatment with low dose diuretics or beta-blockers are cleared for elderly subjects with either diastolic or isolated systolic hypertension. Treatment with a long-acting dihydropyridine calcium channel blocker shows beneficial effects in reducing cardiovascular morbidity and mortality for elderly people with isolated systolic hypertension. Due to inconsistent findings in a subgroup meta-analysis of antihypertensive drug treatment in very old people, the efficacy of antihypertensive treatment in these subjects still remains unclear.

Adrenergic beta-Antagonists↗
PubMed2000

[Pseudoaneurysm after Bentall's procedure in acute aortic dissection type A: diagnosis using electron beam tomography].

Pseudoaneurysms are a rare complication following replacement of the ascending aorta or aorto-coronary bypass surgery. We report a case with replacement of the aorta ascendens, the aortic valve, and venous aorto-coronary bypass grafting, in whom a pseudoaneurysm developed at the site of one proximal bypass anastomosis. For the preoperative diagnosis, an ultrafast-CT (Electron Beam Tomography, EBT) was done, as neither the pseudoaneurysm, nor the venous graft could be visualized by selective coronary angiography.

Adult↗
PubMed2000

Human glandular kallikrein 2: a potential serum marker for predicting the organ confined versus non-organ confined growth of prostate cancer.

PURPOSE: We measured serum levels of human glandular kallikrein 2 (hK2) in patients with prostate cancer treated with radical retropubic prostatectomy for clinically localized prostate cancer to determine whether preoperative hK2 levels discriminate stage pT2a/b from pathological stage T3a or greater cancer. This finding would help to predict preoperatively the organ confined versus non-organ confined growth of prostate cancer. MATERIALS AND METHODS: A total of 68 consecutive men underwent radical retropubic prostatectomy for clinically localized prostate cancer. Serum was obtained 1 day preoperatively before prostatic manipulation. hK2, and total and free prostate specific antigen (PSA) were measured using immunofluorometric assays. Mean, median and range of hK2, total and free PSA, and the ratio of free-to-total PSA (percent free PSA) were calculated. Each analyte or combination of analytes was evaluated to determine whether it significantly contributed to enhance the discrimination of organ confined from non-organ confined cancer. We calculated the statistical significance of observed differences using the Mann-Whitney U and Kruskal-Wallis tests. Sensitivity and specificity calculations were performed for hK2, total PSA and the algorithm, (hK2) x (total PSA/free PSA) in addition to receiver operating characteristics curves and the respective areas under the curves. Multivariate logistic regression analysis was done for hK2, and total and free PSA RESULTS: Disease was organ and non-organ (extraprostatic extension) confined in 38 and 30 men, respectively. In organ confined cancer mean hK2 was significantly lower than in non-organ confined cancer (0.09 ng./ml., range less than 0.03 to 0.23 versus 0.30, range 0.04 to 0.94, p <0.0001). In addition, there was significantly higher free and total but not percent free PSA in non-organ than in organ confined cases. There were also statistically significant differences in hK2, free PSA and total PSA at each pathological disease stage (p <0.001, <0.01 and <0.05, respectively). Sensitivity for detecting organ confined disease was 37% at 100% specificity (correct identification of all non-organ confined cancer) using hK2 measurements compared with a sensitivity of 14% for total PSA. At a specificity of 95%, sensitivity was 40% for hK2 versus 23% for total PSA, which was a statistically significant gain in sensitivity (p <0.05). Receiver operating characteristics curves demonstrated that hK2 had the largest area under the curve, followed by the algorithm, (hK2) x (total PSA/free PSA), and total PSA (0.76, 0.75 and 0.72, respectively). However, none of area under the curve differences was statistically significant. CONCLUSIONS: Compared with total and free PSA hK2 testing improved the preoperative evaluation of patients who underwent radical retropubic prostatectomy due to the superior discrimination of organ from non-organ confined cancer.

Adenocarcinoma↗
PubMed2000

Clinical value of human glandular kallikrein 2 and free and total prostate-specific antigen in serum from a population of men with prostate-specific antigen levels 3.0 ng/mL or greater.

OBJECTIVES: To investigate the clinical value of human glandular kallikrein 2 (hK2) compared with free (f) and total (t) prostate-specific antigen (PSA) in the early detection of prostate cancer (PCa). METHODS: In PCa screening conducted in 1995 to 1996 in Göteborg, Sweden, 5853 of 9811 randomly selected men (aged 50 to 66 years; median 61) accepted PSA testing; those with tPSA levels of 3. 0 ng/mL or greater were offered digital rectal examination, transrectal ultrasound, and sextant biopsies. Serum from 604 of 611 biopsied men (18% with positive digital rectal examinations, tPSA range 3.0 to 220 ng/mL, 144 men with PCa) was analyzed for hK2 (research assay) and tPSA and fPSA (Prostatus). Sera were stored at -20 degrees C for a maximum of 2 weeks for tPSA and fPSA and 3 years for hK2. RESULTS: hK2 levels and hK2 x tPSA/fPSA values were significantly elevated in men with PCa. Receiver operating characteristic data revealed that the area under the curve for hK2 x tPSA/fPSA was significantly greater than that for tPSA and greater, but not significantly greater, than that for percent fPSA. Also, the cancer-detecting sensitivity was significantly improved (P <0.05) using hK2 x tPSA/fPSA compared with tPSA and percent fPSA at specificity levels of 75% to 90%. At 75% specificity, a sensitivity of 74% was obtained compared with 64% or 54% using percent fPSA or tPSA; at 90% specificity, the corresponding sensitivity level was 55%, 41%, and 36%, respectively. CONCLUSIONS: Discrimination of men with and without PCa in a randomly selected population was improved by measuring hK2 in addition to tPSA and fPSA.

Aged↗
PubMed2000

Association of concentration of asbestos and asbestos-like fibers with the patient's survival and the binding capacity of lung parenchyma to galectin-1 and natural alpha-galactoside- and alpha-mannoside-binding immunoglobulin G subfractions from human serum.

Our aim in this study was to search for lung parenchyma alterations associated with asbestos and/or asbestos-like fiber concentration. This was done by means of immuno- or glycohistochemistry. The hot-ashing technique determined the asbestos and asbestos-like fiber concentrations in the lung tissues of 100 patients of whom 52 were treated for primary lung and 25 for secondary lung tumors; fiber concentration was also measured for 23 patients whose disease was benign. The results were correlated to smoking habits, survival of the patients, and expression of binding capacities for endogenous lectins, natural carbohydrate-binding and lectin-specific antibodies. The cohort with proven asbestos exposure revealed a mean fiber concentration 114 f/g compared to 95 f/g in the non-exposed group. An increased asbestos fiber concentration was correlated to galectin-1-binding and the presence of epitopes for natural immunoglobulin G subfractions with selectivity to alpha-galactosides and alpha-mannosides. The survival of patients with primary and secondary lung tumors was negatively associated with the fiber concentration. The data indicate that increased presence of asbestos is correlated with an alteration of defined glycohistochemical features of alveolar lining cells.

Adult↗
PubMed2000

The families of papain- and legumain-like cysteine proteinases from embryonic axes and cotyledons of Vicia seeds: developmental patterns, intracellular localization and functions in globulin proteolysis.

Families of papain- and legumain-like cysteine proteinases (CPR) were found in Vicia seeds. cDNAs and antibodies were used to follow organ specificity and the developmental course of CPR-specific mRNAs and polypeptides. Four papain-like cysteine proteinases (CPR1, CPR2, proteinase A and CPR4) from vetch seeds (Vicia sativa L.) were analysed. CPR2 and its mRNA were already found in dry embryonic axes. CPR1 was only detected there during early germination. Both CPR1 and CPR2 strongly increased later during germination. In cotyledons, both CPR1 and CPR2 were only observed one to two days later than in the axis. Proteinase A was not found in axes. In cotyledons it could only be detected several days after seeds had germinated. CPR4 mRNA and polypeptide were already present in embryonic axes and cotyledons during seed maturation and decreased in both organs during germination. Purified CPR1, CPR2 and proteinase A exhibited partially different patterns of globulin degradation products in vitro. Although the cDNA-deduced amino acid sequence of the precursor of proteinase A has an N-terminal signal peptide, the enzyme was not found in vacuoles whereas the other papain-like CPRs showed vacuolar localization. Four different legumain-like cysteine proteinases (VsPB2, proteinase B, VnPB1 and VnPB2) of Vicia species were analysed. Proteinase B and VnPB1 mRNAs were detected in cotyledons and seedling organs after seeds had germinated. Proteinase B degraded globulins isolated from mature vetch seeds in vitro. VsPB2 and proteinase B are localized to protein bodies of maturing seeds and seedlings, respectively, of V. sativa. Like VsPB2 from V sativa, also VnPB2 of V. narbonensis corresponds to vacuolar processing enzymes (betaVPE). Based on these results different functions in molecular maturation and mobilization of storage proteins could be attributed to the various members of the CPR families.

Chemical Fractionation↗
PubMed2000

Blockade of interleukin 6 trans signaling suppresses T-cell resistance against apoptosis in chronic intestinal inflammation: evidence in crohn disease and experimental colitis in vivo.

The pro-inflammatory cytokine interleukin (IL)-6 (refs. 1-5) can bind to cells lacking the IL-6 receptor (IL-6R) when it forms a complex with the soluble IL-6R (sIL-6R) (trans signaling). Here, we have assessed the contribution of this system to the increased resistance of mucosal T cells against apoptosis in Crohn disease (CD), a chronic inflammatory disease of the gastrointestinal tract. A neutralizing antibody against IL-6R suppressed established experimental colitis in various animal models of CD mediated by type 1 T-helper cells, by inducing apoptosis of lamina propria T cells. Similarly, specific neutralization of sIL-6R in vivo by a newly designed gp130-Fc fusion protein caused suppression of colitis activity and induction of apoptosis, indicating that sIL-6R prevents mucosal T-cell apoptosis. In patients with CD, mucosal T cells showed strong evidence for IL-6 trans signaling, with activation of signal transducer and activator of transcription 3, bcl-2 and bcl-xl. Blockade of IL-6 trans signaling caused T-cell apoptosis, indicating that the IL-6-sIL-6R system mediates the resistance of T cells to apoptosis in CD. These data indicate that a pathway of T-cell activation driven by IL-6-sIL-6R contributes to the perpetuation of chronic intestinal inflammation. Specific targeting of this pathway may be a promising new approach for the treatment of CD.

Adult↗
PubMed2000

Would prostate cancer detected by screening with prostate-specific antigen develop into clinical cancer if left undiagnosed? A comparison of two population-based studies in Sweden.

OBJECTIVE: To assess the risk of over-diagnosing and over-treating prostate cancer if population-based screening with serum prostate-specific antigen (PSA) is instituted. PATIENTS AND METHODS: From a serum bank stored in 1980, PSA was analysed in 658 men with no previously known prostate cancer from a well-defined cohort from Göteborg, Sweden (men born in 1913); the incidence of clinical prostate cancer was registered until 1995. From the same area, and with the same selection criteria, another cohort of 710 men born in 1930-31, who in 1995 accepted an invitation for PSA screening, was also analysed. RESULTS: Of men born in 1913, 18 (2.7%) had died from prostate cancer and the cumulative probability of being diagnosed with clinical prostate cancer was 11.1% (5.0% in those with a PSA level of < 3 ng/mL vs 32.9% in those with a PSA level of > 3 ng/mL, P < 0.01). The mean lead-time from increased PSA (> 3 ng/mL) to clinical diagnosis was 7 years. The prostate cancer detection rate in men born in 1930-31 was 4.4% (22% among those with increased PSA levels) and 30 of 31 detected cancers were clinically localized. CONCLUSIONS: Screening and sextant biopsies resulted in a lower detection rate (22%) than the cumulative risk of having clinical prostate cancer (33%) in men with increased PSA levels, indicating that under-diagnosis rather than over-diagnosis is the case at least with 'one-time' screening. Even if the stage distribution in screening-detected cancers seems promising (and thus may result in reduced mortality) it is notable that screening 67-year-old men will result in treatment a mean of 7 years before clinical symptoms occur and only one in four men anticipated to develop prostate cancer will die from the disease within 15 years. Large randomized screening trials seem mandatory to further explore the benefits and hazards of PSA screening.

Aged↗
PubMed2000

Quantitative impact of pediatric sinus surgery on facial growth.

OBJECTIVE/HYPOTHESIS: To quantitatively evaluate the long-term impact of sinus surgery on paranasal sinus development in the pediatric patient. STUDY DESIGN: Longitudinal review of eight pediatric patients treated with unilateral sinus surgery for periorbital or orbital cellulitis with an average follow-up of 6.9 years. Control subjects consisted of two groups, 9 normal adult patients with no computed tomographic evidence of sinusitis and 10 adult patients with scans consistent with sinusitis and a history of sinus-related symptoms extending to childhood. METHODS: Application of computed tomography (CT) volumetrics, a technique allowing for precise calculation of volumes using thinly cut CT images, to the study and control groups. RESULTS: Paired Student t test analyses of side-to-side volume comparisons in the normal patients, patients with sinusitis, and patients who had surgery revealed no statistically significant differences. Comparisons between the orbital volumes of patients who did and did not have surgery revealed a statistically significant increase in orbital volume in patients who had surgery. CONCLUSIONS: Only minimal changes in facial volume measurements have been found, confirming clinical impressions that sinus surgery in children is safe and without significant cosmetic sequelae.

Adolescent↗
PubMed2000

Cardiac imaging by means of electrocardiographically gated multisection spiral CT: initial experience.

The authors introduce a method for cardiac investigations by using electrocardiographically gated spiral scanning with a four-section computed tomographic system. Three-dimensional images were reconstructed by means of a 250-msec temporal resolution and continuous volume coverage by using a dedicated multisection cardiac volume reconstruction algorithm. Motion-free thin-section volume images were acquired with thin sections and overlapping image increments within a single breath hold. Data segment shifts in time allowed for multiphase imaging.

Calcinosis↗
PubMed2000

Discrimination of men with prostate cancer from those with benign disease by measurements of human glandular kallikrein 2 (HK2) in serum.

PURPOSE: To investigate the clinical value of measuring human glandular kallikrein 2 (hK2) compared with free and total prostate specific antigen (PSA-F and PSA-T) in serum from patients with prostate disease. MATERIALS AND METHODS: Serum from healthy controls, from men with benign prostate hyperplasia (BPH), clinically localized prostate cancer (PCa), and advanced PCa were analyzed for hK2 (using an in-house-research assay with detection limit of 0.05 ng./mL and <0.1% cross-reaction with PSA) and for PSA-F and PSA-T (using the Dual Prostatus assay from EG&G Wallac). RESULTS: HK2 concentrations were <0.05 ng./mL in 50/50 healthy volunteers but significantly higher (p <0.0001) and > or =0.05 ng./mL in 28/54 (52%) patients with BPH. In comparison to these men, the hK2 levels were significantly higher (p <0.0001, median 0.085 ng./mL) and > or =0.05 ng./mL in 100/136 (74%) men with clinically localized PCa. Compared with localized PCa, the hK2 levels were significantly higher (p <0.0001, median 0.57 ng./mL) and > or =0.05 ng./mL in 55/57 (96%) patients with advanced PCa. The median hK2 levels ranged from 1.3 to 1.6% of those of PSA-T in all three patient groups, whereas percent hK2/PSA-F and hK2 x PSA-T/PSA-F levels were significantly higher in cancer patients compared with those with BPH. In the discrimination of clinically localized PCa from BPH, hK2 x PSA-T/PSA-F gave the largest area under the receiver operating curve (AUC = 0.81) and significantly (p = 0.025) larger AUC than PSA-T alone (0.70). Further, at 95% sensitivity there was significant gain in specificity, and at specificity levels of 90 to 95% there was significant gain in sensitivity using the measurements of PSA-T+PSA-F+hK2 compared with analysis of PSA-T and/or percent free PSA. CONCLUSIONS: Discrimination of patients with benign prostate disease from those with prostate cancer was significantly enhanced using measurements of hK2 in addition to those of PSA-T and PSA-F. Percent hK2/PSA-F was higher in PCa than in BPH, a phenomena not yet understood.

Adult↗
PubMed2000

Sensitive and specific immunodetection of human glandular kallikrein 2 in serum.

BACKGROUND: Human glandular kallikrein 2 (hK2) is expressed in the prostate and is present in serum from men with prostate cancer. Specific detection in serum is difficult mainly because of low concentrations and immunological cross-reactivity with prostate-specific antigen (PSA). Our objectives were to design an assay with improved analytical detection and functional sensitivity and nonsignificant cross-reactivity with PSA, and to characterize different immunoreactive forms of hK2. METHODS: In the assay, critical PSA epitopes were blocked with four monoclonal antibodies (MAbs) specific for PSA. Subsequently, hK2 was captured using a MAb against hK2 (5% cross-reactivity with PSA), and after washing, hK2 was detected by a europium-labeled MAb with identical affinity for hK2 and PSA. RESULTS: The analytical detection limit was <10 ng/L, and functional sensitivity was 30 ng/L. Cross-reaction with PSA was <0.01%. Between-assay imprecision was 3.1% for 1600 ng/L hK2 and 4. 8% for 160 ng/L hK2; corresponding values for within-assay precision were 1.9% and 4.5%, respectively. Complexes of hK2-alpha(1)-antichymotrypsin (ACT) were detected in vitro with -6% bias compared with the free form of hK2. Gel filtration of patient samples showed that hK2 correlated in size mainly with free hK2; only 4-19% corresponded to hK2 possibly complexed with ACT or protein C inhibitor. CONCLUSIONS: Our assay had extremely low cross-reactivity with PSA, provided a very low detection limit, and allowed close to equimolar detection of the free and complexed forms of hK2. Moreover, we found that free hK2 is the predominant immunoreactive form of hK2 in serum.

Adolescent↗
PubMed2000

Comparison of globulin mobilization and cysteine proteinases in embryonic axes and cotyledons during germination and seedling growth of vetch (Vicia sativa L.).

Vicilin and legumin, the storage globulins of mature dry vetch (Vicia sativa L.) seeds, are found in protein bodies which are present not only in the cotyledons, but also in the radicle, axis and shoot (together, for reasons of simplicity, here called axis). When at 24 h after the start of imbibition (hai) the radicle breaks through the seed coat a major part of the globulins in the axis has already been degraded, whereas in the cotyledons globulin breakdown cannot yet be detected. Globulin mobilization starts with the degradation of vicilin. At 48 hai when globulin mobilization in the cotyledons just begins, the axis is already nearly depleted of globulins. Mobilization of storage globulin is probably brought about by a complex of different cysteine proteinases (CPRs). The papain-like CPR2 and CPR4, and the legumain-like VsPB2, together with their mRNAs, are already present in axes and cotyledons of dry seeds. This means that they must have been formed during seed maturation. Additional papain-like CPRs are formed later during germination and seedling growth. CPR4 and VsPB2 together with their corresponding mRNAs become undetectable as germination and seedling growth proceed. VsPB2 and VsPB2-mRNA are substituted by the homologous legumain-like proteinase B and its mRNA. The composition of stored and newly formed CPRs undergoes developmental changes which differ between axes and cotyledons. It is concluded that storage globulin mobilization in germinating vetch seeds is started by stored CPRs, whereas the mobilization of the bulk of globulin is predominantly mediated by CPRs which are formed de novo.

Cotyledon↗