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B Kramer

Publications and source records attributed to B Kramer.

At least 73 records · Page 4Linked to original sources
PubMed1996

High-level expression of tree pollen isoallergens in Escherichia coli.

cDNAs coding for the major allergen of alder (Alnus glutinosa) pollen Aln g 1, for nine isoforms of Bet v 1, the major birch (Betula verrucosa) pollen allergen, and for four isoforms of Cor a 1, the major allergen of hazel (Corylus avellana) pollen, were inserted into the plasmid pMW175 or pMW 172 and expressed in Escherichia coli as recombinant non-fusion proteins. These constructs produced between 20 and 160 mg protein/l. The recombinant tree pollen isoallergens were tested in immunoblots for their antibody binding properties. For this purpose, we used two monoclonal antibodies (BIP 1 and BIP 4) raised against natural Bet v 1, a polyclonal rabbit anti-recombinant Bet v 1a, as well as serum IgE from allergic patients. Our results show that this expression system is suitable for the production of milligram amounts of tree pollen isoallergens which can be used for the characterization of allergenic epitopes recognized by T and B cells.

Allergens↗
PubMed1996

Results of a program to improve the process of inpatient care of adult asthmatics.

OBJECTIVE: To assess the effectiveness of a program to improve care of adult patients hospitalized for asthma. DESIGN: Retrospective analysis of patient and house staff education, patterns of medication use, spacer use, peak flowmeter use, and length of stay before and after team intervention. SETTING: A 960-bed teaching hospital in New York City. PATIENTS: All patients admitted to the hospital with a primary diagnosis of acute asthma exacerbation for 2 separate similar calendar periods, 1 year apart, before and after program intervention. We excluded patients who were hospitalized for less than 24 h or greater than 10 days. The preintervention group comprised 61 patients and the postintervention group 65 patients, well matched in their demographic characteristics and severity of disease. INTERVENTIONS: Using a team approach, we analyzed the process of inpatient treatment of asthma exacerbation, identified root causes for quality deficiency, and implemented specific improvements in the process. These included dedicated nurses who focused on the education of care providers and patients, a personalized attending-intern educational approach, and improvement in the supply and delivery of spacers, peak flowmeters, and medications to the patients. RESULTS: There was a significant increase in use of spacers, peak flowmeters, and inhaled corticosteroids. Systemic corticosteroid and methylxanthine use declined. Length of stay was reduced without increasing early hospital readmission rates. CONCLUSIONS: This program improved the treatment process of adults hospitalized for asthma.

Acute Disease↗
PubMed1996

[Evaluation of psychiatric treatment teams by relatives].

262 members of the Austrian relatives' self-help organisation HPE evaluated their experience with 12 types of psychiatric professionals and judged their satisfaction with the behaviour of these professionals on a 5-point scale corresponding to the Austrian school mark system (1 = the best mark, 5 = the worst mark). Overall the core group of psychiatric professionals-psychiatrists, psychologists and nurses-had the worst rating, while non-core professionals like occupational therapists, social workers and ambulance aids received the highest satisfaction ratings. One possible explanation for the dissatisfaction with the core psychiatric professionals is the unmet needs of the relatives for information, which 93% complained of. It is suggested to teach professionals systematically how to evaluate the needs of relatives and how to communicate with them in a more satisfying way.

Adult↗
PubMed1996

A radiographic analysis of the mandibular canal of the edentulous mandible in different racial and gender groups.

Studies on the mandibular canal in the edentulous mandible have rarely been correlated with mandibular canal position, mandibular body width, mandibular canal width, thickness of bony plates, gender and race. The aim of this investigation was to examine the above parameters by studying the bucco-lingual relationship of the mandibular canal in dry edentulous mandibles of Black and White, males and females (n = 13 in each group), of similar age (mean 58, 17 yrs). The mandibles were radiographed cross-sectionally. The position of the mandibular canal in relation to the buccal and lingual cortical plates, and the widths of the mandibular canal and mandibular body, measured at selected distances, were recorded and the values statistically analysed. Race and gender do not seem to influence the position of the mandibular canal in the bucco-lingual plane. The location of the canal is predominantly closer to the lingual cortex in the bucco-lingual plane. It was found that the widths of the left and right halves of the mandibular body are not statistically significantly different but widths of the left and right mandibular canal are significantly different.

Adult↗
PubMed1995

Characterization of a 100-kilodalton binding protein for the six serotypes of coxsackie B viruses.

Viral infection of host cells primarily depends on binding of the virus to a specific cell surface protein. In order to characterize the binding protein for group B coxsackieviruses (CVB), detergent-solubilized membrane proteins of different cell lines were tested in virus overlay protein-binding assays. A prominent virus-binding protein with a molecular mass of 100 kDa was detected in various CVB-permissive human and monkey cell lines but was not detected in nonpermissive cell lines. The specificity of CVB binding to the 100-kDa protein on permissive human cells was substantiated by binding of all six serotypes of CVB and by competition experiments. In contrast, poliovirus and Sendai virus did not bind to the 100-kDa CVB-specific protein. A fraction of HeLa membrane proteins enriched in the range of 100 kDa showed functional activity by transforming infectious CVB (160S) into A-particles (135S). In order to purify this CVB-binding protein, solubilized membrane proteins from HeLa cells were separated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by elution of the 100-kDa protein. Amino acid sequence analysis of tryptic fragments of the CVB-binding protein indicated that this 100-kDa CVB-specific protein is a cell surface protein related to nucleolin. These results were confirmed by immunoprecipitations of the CVB-binding protein with nucleolin-specific antibodies, suggesting that a nucleolin-related membrane protein acts as a specific binding protein for the six serotypes of CVB.

Amino Acid Sequence↗
PubMed1995

Geographic, age, and racial variation in the treatment of local/regional carcinoma of the prostate.

PURPOSE: Prostate cancer is one of the most common cancers in men. Incidence rates increase with age and are substantially higher in black men than white men. This study examines the variations in the use of radical prostatectomy and radiation by geographic area, age, and race. MATERIALS AND METHODS: Data from the National Cancer Institute's Surveillance, Epidemiology, and End-Results Program (SEER) were used to examine treatment differences. Current treatments generally consist of prostatectomy, radiation, or careful observation for clinically localized or regional disease. RESULTS: The age-adjusted proportion of men, age 50 and older, who received radical prostatectomy increased sharply between 1984 and 1991, from 11.0% to 32.3% among men with local/regional disease. The choice of treatment varied widely by geographic regions. In 1991, the proportion that received prostatectomy was highest in Utah (47.8%) and lowest in Connecticut (22.5%) among men with localized and regional disease. The increase in radical prostatectomy was not limited to younger men. Although the rates increased for blacks, black men had lower age-adjusted rates of prostatectomy than whites in all years of the study. CONCLUSION: The SEER data show a clear trend toward more aggressive treatment, especially prostatectomy. However, the proportion of black men who received prostatectomy was substantially lower than that of white men and this disparity does not appear to be changing.

Black or African American↗
PubMed1995

Electrosensory stimulus-intensity thresholds in the weakly electric knifefish Eigenmannia: reduced sensitivity at harmonics of its own organ discharge

The South American knifefish Eigenmannia sp. can detect the electric organ discharges (EODs; 250­600 Hz) of conspecifics when they are superimposed over its own EOD. This study investigates the minimum frequency difference necessary for such signal perception, using the application of sine-wave stimuli. Electrosensory stimulus-intensity thresholds were determined for trained fish using stimuli associated with food rewards. These sine-wave stimuli were 'clamped' to the EOD frequency of the fish. Electrosensory thresholds were also determined for the spontaneous jamming avoidance response (JAR; a change in EOD frequency evoked by a stimulus of sufficiently similar frequency), in this case using unclamped stimuli. Over the wide frequency range investigated (0.3­3.01 times EOD frequency), the lowest stimulus-intensity thresholds of 0.6 µV cm-1 (peak-to-peak) (0 dB) at a water conductivity of 100 µS cm-1 were found close to (but not exactly at) the EOD fundamental frequency. At exact frequency identity between the EOD and the stimulus, the stimulus-intensity response threshold rose abruptly by more than 10 dB compared with slightly higher or lower stimulus frequencies. A similar 'needle-like' threshold increase was found at exactly two and three times the EOD frequency, but neither at harmonic ratios between stimulus and EOD frequency that represent fractions (e.g. at 5:4=1.25, 4:3=1.33, 3:2=1.5 or 5:3=1.67 times EOD frequency) nor at subharmonics such as half or two-thirds of the EOD frequency. The steepest increase of stimulus-intensity response threshold was in the range 0.998­1.002 times EOD frequency, corresponding to a threshold change, or electrosensory filter slope, of 5000 dB per octave. For the spontaneous JAR, a similar stimulus-intensity threshold increase was observed when EOD frequency equalled stimulus frequency. Because of the longer rise time for the stimulus amplitude (400 ms rather than 35 ms) the stimulus intensity threshold was higher (up to 32 dB; mean, 20 dB) than in the other experiments (up to 15 dB; mean, 13 dB). A difference in frequency between the EOD and the applied stimulus as small as 1 Hz (that is, 0.2 % of the EOD frequency) was sufficient for good signal perception in Eigenmannia sp. The JAR appears to be useful in avoiding insensitivity at exact integer harmonics of the EOD frequency.

Journal Article↗
PubMed1995

Electrosensory thresholds in larvae of the weakly electric fish Pollimyrus isidori (Mormyridae, Teleostei) during ontogeny

Electrosensory thresholds and tuning were determined from behavioural studies in larvae of Pollimyrus isidori using the stop response of their electric organ discharge to weak electrical stimuli. Two age groups were studied: (1) 10- to 15-day-old larvae in which the electric organ discharge (EOD), produced by a distinct larval electric organ, had just stabilized; (2) 54- to 60-day-old larvae, just before the advent of the adult EOD (an adult electric organ functionally replaces that of the larva between about 60 and 80 days). Three stimulus pulse waveforms were used: (1) single-cycle, bipolar sine-wave pulses; (2) single-cycle, monopolar sine-wave pulses and (3) monopolar square-wave pulses. The younger larvae were exceedingly sensitive to weak electrical stimuli, down to the 10 µVp­p cm-1 range. Stimulus pulse duration had a significant effect on threshold for all three pulse waveforms, but the shapes of the tuning curves were quite different. Thresholds at the 'best' pulse duration were lower and the tuning sharper (with a V-shaped curve) with monopolar sine-wave pulses than with bipolar sine-wave pulses. The 'best' pulse duration was 1 ms for both sine-wave pulses, corresponding well to the spectral peak amplitude of larval EODs (964±22 Hz). The threshold curve for monopolar sine-wave pulses appeared to be perfectly adapted for sensing larval rather than adult EODs. With square-pulse stimuli, thresholds increased monotonically with duration and there was no evidence of tuning for this kind of stimulus. These results suggest that both conventional spectral tuning and 'tuning' to a particular pulse waveform (with a monopolar sine-wave pulse best approximating the waveform of a larval discharge) are found in young larvae. In the older age group, larvae were more sensitive to all three kinds of stimuli than those of the younger age group. The sensitivity increase varied from 10 dB to 29 dB; at stimuli of 2.4 µVp­p cm-1, larvae just 18 mm long displayed adult sensitivity. No tuning was seen for square-wave pulses and, as in younger larvae, their effectiveness increased monotonically with duration, so that for neither age group are square-wave pulses a good model for larval EODs. The threshold curves for both types of sine-wave pulse were similar and resembled the broadband tuning curves of Knollenorgan electroreceptors. Tuning was present but weak, with sensitivity for the high-frequency range much greater than for younger larvae. This change is adaptive for sensing both larval and adult EODs and occurred before the larvae developed an adult EOD. The mechanism for a change in tuning that has been established for electroreceptors in adult mormyrids and gymnotiforms, where the spectral properties of the EOD of a fish entrain its electroreceptors, is not found in the larvae of Pollimyrus isidori, which 'anticipate' the tuning necessary for the reception of their own, future adult EOD.

Journal Article↗
PubMed1995

Time-efficient docking of flexible ligands into active sites of proteins.

We present an algorithm for placing flexible molecules in active sites of proteins. The two major goals in the development of our docking program, called FLEXX, are the explicit exploitation of molecular flexibility of the ligand and the development of a model of the docking process that includes the physico-chemical properties of the molecules. The algorithm consists of three phases: The selection of a base fragment, the placement of the base fragment in the active site, and the incremental construction of the ligand inside the active site. Except for the selection of the base fragment, the algorithm runs without manual intervention. The algorithm is tested by reproducing 11 receptor-ligand complexes known from X-ray crystallography. In all cases, the algorithm predicts a placement of the ligand which is similar to the crystal structure (about 1.5 A RMS deviation or less) in a few minutes on a workstation, assuming that the receptor is given in the bound conformation.

Algorithms↗
PubMed1995

Superovulation affects glucosamine trisaccharides in the glycocalyx of the rat endometrium at the time of implantation.

The presence of glucosamine trisaccharides in the glycocalyx of surface epithelial cells of the endometrium of hyperstimulated pregnant rats was compared with that of normal pregnant animals by means of lectin-avidin-ferritin histochemistry. The lectin Phytolacca americana was used. A statistically significant reduction in ferritin particles and hence, glucosamine trisaccharides, was found in the glycocalyx of the hyperstimulated animals when compared with that of the controls. This reduction could contribute to the failure of implantation in hyperstimulated animals.

Animals↗