Biomedical subjects

B Bock

Publications and source records attributed to B Bock.

At least 19 recordsLinked to original sources

PubMed2006

Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam.

This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).

Journal Article↗

PubMed2003

[Familial versus sporadic prostate cancer in the German population. Clinical and pathological characteristics in patients after radical prostatectomy].

Family history is one of the strongest epidemiological risk factors for the development of prostate cancer. The impact on the clinical presentation and prognosis, however, is controversial. In the present study, we analyzed 464 familial and 492 sporadic prostate cancer patients following radical prostatectomy. The average age at onset was 62.1 years in the familial group and 64.2 years in the sporadic controls (p<0.001). The screening attitude, DRE findings and the PSA values at diagnosis the pT- and pN-stages, and the tumor grade did not differ between both groups. With a median follow-up of 3.3 years, the 5- and 10-year progression-free survival rates were 76.2% and 56.5% in familial and 70.8% and 55.5% in sporadic patients, respectively (n.s.). A multiple logistic regression analysis revealed that family history did not have an influence on disease recurrence. In our population there was no association between a familial predisposition and clinical features or clinical course of the disease. Whether hereditary prostate cancer is distinct from sporadic forms cannot be determined before the underlying genetic alterations are identified.

Adult↗

PubMed2003

Association between the clinical presentation and epidemiological features of familial prostate cancer in patients selected for radical prostatectomy.

OBJECTIVE: We evaluated if epidemiological features of familial prostate cancer are associated with certain clinical or histopathological characteristics of the disease. METHODS: 463 German patients with familial prostate cancer who underwent radical prostatectomy were stratified according to several epidemiological criteria: (1). the apparent mode of disease transmission, (2). the average age of onset and (3). number of affected relatives/family, (4). whether or not they met the Johns Hopkins criteria of hereditary prostate cancer. The variables analysed included the Prostate Specific Antigen (PSA) and the digital rectal examination at diagnosis, histopathological characteristics of the prostatectomy specimen and relapse free 5-year survival rates. These characteristics were compared within the subsets of familial patients and compared to 492 control patients with sporadic prostate cancer. RESULTS: Age of onset was the only clinical parameter differentiating familial and sporadic prostate cancer. Otherwise there was no association between epidemiological features of familial predisposition and the clinical presentation or outcome of the disease. CONCLUSIONS: Familial and sporadic prostate cancer seem to be the same disease. Alternatively it may be concluded that the common epidemiological features of familial prostate cancer are not useful to tell tumours that are based on inherited susceptibility apart from those that are not. Whether hereditary prostate cancer is clinically distinct from sporadic forms cannot be determined before the underlying genetic alterations are identified.

Age of Onset↗

PubMed2001

Maternal transmission of nicotine dependence: psychiatric, neurocognitive and prenatal factors.

This paper reviews the literature on maternal influences on smoking behaviors of offspring from the perspective of neuropsychiatric deficits that may be transmitted from mother to child. In particular, we review what is known regarding associations between: (1) in-utero exposure to smoking, (2) adolescent neurocognitive functioning and psychiatric comorbidity, and (3) the patterns of smoking and progression of nicotine dependence. Furthering our knowledge of these differences in susceptibility to nicotine dependence among youth will provide additional avenues for prevention and intervention efforts targeted toward those at high risk for dependence.

Adolescent↗

PubMed2000

ECG scores for a triage of patients with acute myocardial infarction transported by the emergency medical system.

Prehospital triage of cardiac patients for bypass from community hospitals to cardiac centers may improve survival. This article determines if electrocardiogram (ECG)-based scoring triage methods (Aldrich MI scoring, QRS distortion, and the TIMI classification) and location of infarct (via 12 lead ECG) are associated with mortality before and after adjusting for age, sex, and race. It is a retrospective study of 291 AMI adult patients transported by ambulance to community hospitals or cardiac centers. Patients with an ED chief complaint of chest pain or dyspnea, presence of MI as defined by ECG findings of 0.1 mV of ST segment elevation in two leads or positive CPK-MB were eligible for the study. The primary outcome variable was 2-year mortality as determined with a metropolitan Detroit tri-county death index. Logistic regression was used to calculate the unadjusted and adjusted odds ratios (with 95% CIs) of the predictor variables with mortality. Of the initial population selected for the study (n = 291), 229 patients were eligible for the analysis. The mean age was 66 years (SD of 14.4) with 63.8% being male and 54% being white. The overall mortality point estimate was 21.3% (95% CI of 15.2 to 27.3%). Aldrich scores and QRS distortion (yes/no) were not associated with mortality. Patients classified as a "high risk" for AMI per TIMI status were almost 3 times more likely to die than those at "low risk" and reached borderline statistical significance (P = .06) after adjusting for the covariates. Having an anterior infarct, as opposed to an inferior infarct, was significantly associated with death before and after adjusting for the covariates (Unadjusted OR = 2.6, Adjusted OR = 2.8). Properly training emergency medical system professionals in this area may prove useful for identifying higher risk AMI patients in the prehospital setting.

Aged↗

PubMed2000

A prediction model for prehospital triage of patients with suspected cardiac ischemia.

The American College of Cardiology recommends that patients with high risk acute myocardial infarction (AMI) be triaged to hospitals with percutaneous transluminal coronary angioplasty capability. However, there are no prehospital triage criteria to select candidates for bypassing community hospitals and being taken directly to "cardiac centers." This article assesses which independent variables predict death within 7 days in patients with suspected AMI transported by EMS. This is a retrospective study of 291 AMI patients transported by ambulance to 3 hospitals during 1996-1997. Included were patients who were (n = 244) > or =18 years of age, had a ED chief complaint of chest pain or dyspnea for whom we had mortality data. Mortality at 7 days, our primary outcome measure, was obtained by using a metropolitan Detroit tricounty death index records. Differences between the survivors and nonsurvivors were assessed using the Student's t-test and chi-square tests. Multiple triage criteria were assessed for optimal identification of high risk patients by constructing a logistic multivariate model. Among the study population, 15% died within 7 days (95% confidence interval (CI) 10.3-19.2), and this group represented 63.2% of all deaths over a 2 year surveillance period. Survivors, compared to nonsurvivors, were 14.1 years younger (P < or = .001) and more often men (P < or = 0.001). The dispatch time to ED arrival was less among survivors than nonsurvivors (42.8 vs. 50.6 min, P < or = .01). EMS vital signs differed by survivor status. Among survivors, HR was lower (-11.9 bpm; P < or = 0.01), RR was lower (-6.7 rpm; P < or = .001), SBP was higher (+14.5 mmHg; P < or = 0.05) and DBP was higher (+13.2 mm Hg; P < or = .01). A multivariate model identified the following as independent predictors of early mortality: female gender (OR = 2.3; P < or = .05), age > or =65 (OR = 5.9; P < or = .01), RR > or = 20 (OR = 4.6; P < or = .001), SBP < 120 (OR = 2.4; P < or = .05). The overall model was 86% sensitive and 53% specific with an area under the receiving operating characteristic curve of 0.8 (P < or = .001). A triage rule based on a multivariate model can identify the group at high risk of early cardiac death. This decision rule needs to be prospectively validated.

Aged↗

PubMed1997

Efficient downstream processing of maltodextrin phosphorylase from Escherichia coli and stabilization of the enzyme by immobilization onto hydroxyapatite.

Downstream processing by biospecific chromatography of maltodextrin phosphorylase from Escherichia coli, overexpressed in E. coli, was substantially improved by a novel approach using ceramic hydroxyapatite. Wild-type and a less active mutant enzyme were purified from crude bacterial cell extracts in one efficient separation step that yielded phosphorylase in purity > 95% in at least 90% recoveries. At pH 6.9 and 25 degrees C, wild-type and mutant phosphorylases eluted from the hydroxyapatite column at a phosphate concentration of 0.4 M whereas calcium ions failed to displace the enzymes. The dynamic capacity for phosphorylase binding in the presence of bulk proteins was approximately 3 mg enzyme ml-1 matrix. The interaction of E. coli phosphorylase with hydroxyapatite seems to be mediated by surface amino groups, so that the bound enzyme retained almost full catalytic activity. Compared to the soluble enzyme, immobilization onto hydroxyapatite resulted in a more than 30-fold stabilization of wild-type phosphorylase against thermal and proteolytic inactivation and thus could improve the operational stability of phosphorylase during conversion of polysaccharide to glucose 1-phosphate.

Chromatography↗

PubMed1995

Urinary schistosomiasis in Nebraska.

Urinary schistosomiasis, a disease caused by the blood fluke Schistosoma haematobium, is seen in residents of endemic areas of Africa and Southwest Asia. Two cases are described, one in a twelve year old boy and another in a forty-four year old man. This type of infection is often indolent but can have significant long-term sequelae such as urinary obstruction and bladder cancer. The recent increases in U.S. immigration of persons from the areas endemic to schistosomiasis behoove physicians to remember this disease when dealing with patients native to these lands.

Adolescent↗

PubMed1991

[Obstetric and ethical-legal problems in a twin pregnancy with anencephalus and polyhydramnios of the leading twin beyond the 28th week of pregnancy].

Malformations are found twice as often in twins than in singletons. In the following case, we report on a twin pregnancy with anencephaly and polyhydramnion of the leading twin I, which was first diagnosed after 28 weeks of pregnancy. The foetal disease of twin I led to an appreciable dyspnoea of the mother that exacerbated to an incipient respiratory failure by the thirty-second week of pregnancy. The projected termination of pregnancy by Caesarean section based on a maternal indication was not performed, but instead a selective foetocide of the diseased twin. The live twin was delivered spontaneously without complications after thirty-eight weeks of pregnancy. The obstetric and legal ethical problems are discussed.

Anencephaly↗

PubMed1991

Hepatitis B and human immunodeficiency virus infection in street youths in Toronto, Canada.

Hepatitis B and human immunodeficiency virus are transmitted by venereal contact or by the sharing of used needles during drug use. A questionnaire was administered to street youths admitting to prostitution and to a group denying prostitution, as well as to sexually active adolescents who lived with their family and were attending an adolescent medical clinic. The age, gender, race, number of sexual partners, condom use, illicit drug use, anal intercourse and admission to prostitution were recorded for each of the subjects. Serology was obtained for hepatitis B markers and human immunodeficiency virus antibody. Multiple regression analysis was performed to determine the factors which might predict hepatitis B serologic status. A single subject, who admitted to prostitution, was found to be human immunodeficiency virus-seropositive. Seven of 43 (16%) admitted prostitutes compared with 1 of 44 (2%) other street youth and none of 27 controls demonstrated anti-hepatitis B surface antibodies. The higher rate of seropositivity in admitted prostitutes was statistically significant (P less than 0.0097). Two seropositive prostitutes had IgM hepatitis B core antibody suggesting recent infection. Two factors, number of partners (P less than 0.0007) and practice of anal intercourse (P less than 0.05), were identified in the multiple regression analysis as predictive of seropositivity. Thus adolescents who live on the street are at increased risk for becoming infected with hepatitis B virus. The difficulty in ensuring vaccine coverage in this population would support calls for including hepatitis B vaccination as part of childhood immunization.

Adolescent↗

PubMed1990

[Prenatal diagnosis of a sacrococcygeal teratoma with hydrops fetalis and placental hypertrophy--consequences for the further course of pregnancy].

A fetal sacrococcygeal teratoma may cause hypertrophy of the placenta and fetal hydrops. This is dangerous for the fetus and also for the mother. The maternal risk results from preeclampsia and respiratory insufficiency, associated with elevated beta-HCG. In that case, pregnancy should be terminated by caesarean section due to maternal reasons.

Adult↗

PubMed1990

Epithelial tumor cells in bone marrow of patients with colorectal cancer: immunocytochemical detection, phenotypic characterization, and prognostic significance.

A monoclonal antibody (mAb) directed against the cytokeratin (CK) polypeptide no. 18 specifically expressed in cells derived from simple epithelia was used to detect epithelial tumor cells in bone marrow aspirates. Of 156 patients with colorectal carcinoma, 42 presented with cells at the time of primary surgery. The incidence of positive findings varied considerably with the size and the localization of the primary tumor, the involvement of regional lymph nodes, and the presence of clinically manifest metastases. Applying a sensitive double-staining procedure, we could demonstrate that epithelial cells in bone marrow showed a heterogeneic expression of receptors for epidermal growth factor (EGF-R) and transferrin (Tf-R) as well as of the proliferation-associated Ki67 antigen. Also human leukocyte antigen (HLA) class I antigens differed widely in their expression on the CK-positive cells. Clinical follow-up studies on 85 patients showed a significantly higher relapse rate in patients presenting with CK-positive cells in their bone marrow at the time of primary surgery. Twenty-three patients were monitored for the presence or absence of CK-positive cells in bone marrow over time. The majority of monitored patients (18 of 23) exhibited a constant pattern of immunocytochemical findings during the time of observation. Thus, the technique may be useful in identifying high-risk patients as well as in monitoring adjuvant therapeutic trials.

Antibodies, Monoclonal↗

PubMed1988

[Monoclonal antibodies--new probes for diagnosis and therapy. Their use as an example of the micrometastasizing of solid tumors].

Monoclonal antibody CK2, recognizing component No. 18, appeared to be the most suitable reagent for the detection of epithelial tumor cells in bone marrow. Its specificity was confirmed in a double-marker staining procedure (combination of APAAP-technique and radioautography). CK2 positive cells were demonstrated not to reveal any cross-reactivity with an antibody directed against the "leucocyte common antigen". A significant correlation between the presence of epithelial tumor cells in bone marrow and certain conventional risk factors was found. A more detailed phenotypic characterisation could demonstrate the expression of proliferation associated antigens on these cells. Furthermore in an immunotherapeutic approach with monoclonal antibody 17-1A, labelling of the disseminated tumor cells in bone marrow after infusion of the antibody was shown.

Antibodies, Monoclonal↗

PubMed1985