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Biomedical subjects

H Braun

Publications and source records attributed to H Braun.

At least 55 records · Page 3Linked to original sources
PubMed1996

A vicilin-like seed protein of cycads: similarity to sucrose-binding proteins.

Seed storage globulins of the 7S and 11S type are synthesized in the seeds of angiosperms and gymnosperms. We have isolated and characterized a vicilin-like gene expressed in the cycad Zamia furfuraceae. Sequence comparisons reveal clear similarities to a sucrose-binding protein isolated from soybean. We suggest the existence of a superfamily of related genes including both vicilin-like and legumin-like seed globulin genes as well as genes coding for spherulins, germins and sucrose-binding-proteins.

Amino Acid Sequence↗
PubMed1996

Patient controlled analgesia for shock wave lithotripsy: the effect of self-administered alfentanil on pain intensity and drug requirement.

PURPOSE: Second generation lithotriptors offer immersion-free treatment and a decrease in shock wave induced pain. Pain sensations caused by advanced lithotriptors vary widely and have a significant impact on clinical management. We tested patient controlled analgesia during extracorporeal shock wave lithotripsy (ESWL) and quantified analgesic requirements by means of patient controlled analgesia during ESWL of renal stones. MATERIALS AND METHODS: Patients with renal stone disease undergoing ESWL were randomized prospectively to receive an alfentanil infusion titrated by 4 different anesthesiologists not otherwise involved in the study (22 controls) or to self-administer alfentanil via a patient controlled infusion pump (22 patients). As a measure of individual pain sensitivity the detection, pain and tolerance thresholds of electrocutaneous sensitivity were determined in all patients. RESULTS: Alfentanil was used more often in the patient controlled analgesia group than in the control patients (12 versus 8 required the narcotic, respectively, p = 0.226). Patients using patient controlled analgesia needed less drug (0.5 versus 2.15 mg., p = 0.005, median values), tolerated higher discharge voltages and pain intensities, needed significantly fewer shock waves to complete stone fragmentation (1,612 versus 2,105, p = 0.014) and had shorter treatment times (36.9 versus 46.2 minutes, p = 0.069). There was a significant correlation between the duration of shock wave exposure tolerated without analgesia, and pain (p = 0.0009) and tolerance (p = 0.0020) thresholds but not with regard to detection thresholds (p = 0.1400). Male patients showed significantly higher tolerance thresholds to electrocutaneous stimulation (10.2 versus 6.9 mA., p = 0.0238), which corresponded to longer analgesia-free treatment times in male versus female patients (31.7 versus 19.4 minutes, p = 0.0510). CONCLUSIONS: Patient controlled analgesia increases pain tolerance, decreases narcotic requirements, simplifies ESWL as an outpatient procedure and can be used to quantify analgesic requirements during lithotripsy. Pain and tolerance thresholds of electrocutaneous sensitivity are sensitive markers of pain tolerance during lithotripsy, which may be more pronounced in male patients.

Alfentanil↗
PubMed1996

Ultrafast computed tomography and three-dimensional image processing of CT sialography in patients with parotid masses poorly defined by magnetic resonance imaging.

The purpose of this study was to determine the efficacy of ultrafast computed tomography (UF CT) in patients with parotid masses poorly defined by magnetic resonance imaging (MRI) and to evaluate the diagnostic potential of three-dimensional (3-D) UF CT sialography when compared with conventional CT sialograms. Thirteen patients with clinical suspicion of a parotid mass, in whom MRI was degraded by motion, underwent UF CT of the parotid region. Two radiologists independently assessed the CT and MR with respect to tumor localization, intraglandular tumor location, tumor margin characteristics, and infiltration of surrounding tissue. In 9 patients, CT sialography was performed using 3-D image processing. Anatomical details and pathologic findings were assessed by three readers using a numerical grad and compared with the findings derived from conventional CT sialography. Histopathologic specimens were obtained in all cases and correlated with the radiographic findings in a consensus manner following the blinded interpretations. UF CT and (suboptimal) MRI provided the same diagnostic information for the evaluation of tumor localization, and intraglandular location. UF CT was superior to MRI in the detection of tumor infiltration, and definition of tumor margins in 2 cases (15%), resulting in a substantial difference in treatment. Three-dimensional CT sialography offered significant improvement in demonstration of anatomic detail (2.5 +/- 0.2 vs 1.5 +/- 0.1, respectively) and pathologic findings (2.6 +/- 0.1 vs 1.3 +/- 0.2, respectively) when compared with conventional CT sialography. UF CT is a viable alternative in uncooperative patients with parotid masses. UF CT 3-D sialography has the potential to allow more precise pre-surgical planning and contributes to the diagnosis and therapy planning of parotid masses.

Adult↗
PubMed1995

Evolution of seed storage protein genes: legumin genes of Ginkgo biloba.

Legumin-like seed storage proteins have been intensively studied in crop plants. However, little is known about the molecular evolution of these proteins and their genes and it was assumed that they originated from an ancestral gene that already existed at the beginning of angiosperm evolution. We have evidence for the ubiquitous occurrence of homologous proteins in gymnosperms as well. We have characterized the major seed storage globulin from Ginkgo biloba by amino acid sequencing, which reveals clear homology to legumin-like proteins from angiosperms. The Ginkgo legumin is encoded by a gene family; we describe two of its members. The promoter regions contain sequence motifs which are known to function as regulatory elements involved in seed-specific expression of angiosperm legumins, although the tissues concerned are different in gymnosperms and angiosperms. The Ginkgo legumin gene structure is divergent from that of angiosperms and suggests that the evolution of legumin genes implicated loss of introns. From our data and from functional approaches recently described it becomes obvious that the posttranslational processing site of legumin precursors is less conserved than hitherto assumed. Finally, we present a phylogenetic analysis of legumin encoding sequences and discuss their utility as molecular markers for the reconstruction of seed plant evolution.

Amino Acid Sequence↗
PubMed1995

Legumin-like and vicilin-like seed storage proteins: evidence for a common single-domain ancestral gene.

Legumin-like 11S and vicilin-like 7S globulins are the main storage proteins of most angiosperms and gymnosperms. The subunits of the hexameric legumin are synthesized as a precursor comprising a N-terminal acidic alpha- and a C-terminal basic beta-chain. The trimeric vicilin molecule consists of subunits composed of two symmetrical N- and C-terminal structural domains. In a multiple alignment we have compared the N-terminal and C-terminal domains of 11 legumins and seven vicilins of several dicot, monocot, and gymnosperm species. The comparisons using all six possible pairwise combinations reveal that the N-terminal and C-terminal domains of both protein families are similar to each other. These results together with data on the distribution of variable and conserved regions, on the positions of susceptible sites for proteolytic attack, as well as on the published 7S protein tertiary structure suggest that both protein families share a common single-domain ancestor molecule and lead to the hypothesis that a triplication event has occurred during the evolution of a putative legumin/vicilin ancestor gene. Moreover, the comparison of the intron/exon pattern reveals that at least three out of five intron positions are precisely conserved between the genes of both protein families, further supporting the idea of a common evolutionary origin of recent legumin and vicilin encoding genes.

Amino Acid Sequence↗
PubMed1995

Seed storage proteins of spermatophytes share a common ancestor with desiccation proteins of fungi.

The legumin- and vicilin-like seed storage globulins of spermatophytes are specifically accumulated during embryogenesis and seed development. Previous studies have shown that a precursor common to both legumin and vicilin genes might have evolved by duplication from a single-domain ancestral gene. We here report that amino acid sequences of legumin and vicilin domains share statistically significant similarity to the germination-specific germins of wheat as well as to the spherulation-specific spherulins of myxomycetes. This conclusion is further supported by the derived intron-exon structure of a spherulin gene. Spherulins are thought to be involved in tissue desiccation or hydration. It is suggested that the present-day seed globulins of spermatophytes have evolved from a group of ancient proteins functional in cellular desiccation/hydration processes.

Amino Acid Sequence↗
PubMed1995

High water intake combined with low sodium intake abolishes the antidiuretic effect of angiotensin II in conscious dogs.

1. We studied post-prandial changes in renal function in dogs adapted to either low or high sodium intake with and without concomitant post-prandial infusion of angiotensin II. Six trained dogs were exposed to diets containing either 0.5 or 14.5 mmol Na+ day-1 kg-1 body weight (low or high sodium respectively). They were studied from 20 min before to 4 h after food intake. In half of the experiments a physiological dose of angiotensin II (4 ng min-1 kg-1 body weight) was administered after food intake for four post-prandial hours. The water intake was high and equal on both diets (91 ml day-1 kg-1 body weight). 2. On a high-salt diet post-prandial sodium excretion and urine volume increased considerably above fasting values. This post-prandial increase was attenuated when angiotensin II was infused (post-prandial sodium excretion was 31% +/- 3% of intake without versus 10% +/- 1% with angiotensin II, post-prandial urine volume was 22% +/- 2% without versus 8% +/- 1% with angiotensin II, P < 0.05). Post-prandial increases in glomerular filtration rate and fractional sodium excretion were attenuated during angiotensin II infusion in dogs on a high-salt diet. 3. On a low-salt diet post-prandial sodium excretion remained low with or without angiotensin II infusion, whereas urine volume increased post-prandially, and this increase was greater when angiotensin II was administered (40% +/- 3% versus 34% +/- 2% of intake, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1995

Three-dimensional processing of ultrafast CT sialography for parotid masses.

PURPOSE: To evaluate the diagnostic potential of three-dimensional image processing of ultrafast CT sialography in comparison with conventional CT sialography in patients with parotid masses. METHODS: In nine patients, CT sialography was done with three-dimensional image processing. The visibility of anatomic details and pathologic findings, derived from three-dimensional images, were graded numerically by three observers and compared with the findings obtained from conventional CT sialograms. Histopathologic specimens were obtained in all cases. RESULTS: Ultrafast CT images showed no motion artifact. Three-dimensional CT sialography offered significant improvement in demonstration of ductal anatomy (2.5 +/- 0.2 versus 1.5 +/- 0.1, respectively) and ductal pathology (2.6 +/- 0.1 versus 1.1 +/- 0.2, respectively) over conventional CT sialography. In two cases, the therapeutic regimen was altered substantially. CONCLUSION: Ultrafast CT three-dimensional sialography has the potential to allow more precise presurgical planning and contributes to the diagnosis and therapy planning of parotid masses, especially in patients in whom MR image quality is degraded by motion artifact.

Adult↗
PubMed1994

The sphenoid sinus during childhood: establishment of normal developmental standards by MRI.

To obtain baseline standards of normal age-related development of the sphenoid sinus during childhood magnetic resonance images of the sphenoid sinus in 401 patients less than 15 years old were reviewed. T1-weighted sagittal and T2-weighted axial scans were evaluated for bone marrow conversion, development of pneumatization, spatial enlargement and septation of the sphenoid sinus. The sphenoid sinus had a uniformly low signal intensity (red bone marrow) on T1-weighted images in all children less than 4 months old. Signal intensity changes from hypo- to hyperintense (bone marrow conversion) started at age of 4 months. Onset of pneumatization was observed in 12% of the patients at age 13-15 months. By age 43-48 months, 85% of the patients showed pneumatization of the anterior part of the sphenoid bone. Pneumatization was complete in all patients older than 10 years. Enlargement of the sinus showed a characteristic profile in each dimension. Median septation was observed irregularly with age, with a maximum of 77%. Septum variants were noticed between 4.5% and 20%. The recognition of this phenomenon may serve as a reference for evaluating normal and abnormal development of the sphenoid sinus and may be of great value for diagnostic and therapeutic management of pathologic conditions of the child's sphenoid sinus and its surrounds.

Adolescent↗
PubMed1994

A convenient synthesis of nucleoside monophosphate-N-acetylneuraminic acids (NMP-Neu5Ac).

Reaction of sialyl phosphites 2a,b with acetyl-protected ribonucleoside monophosphates 3C, 3U, 3A and 3G furnished without addition of a catalyst directly the corresponding beta-configurated sialyl ribonucleoside monophosphates 4C, 4U, 4A and 4G, respectively. Treatment of these compounds with sodium methanolate in methanol and sodium hydroxide afforded the disodium salts of CMP-Neu5Ac (1C), UMP-Neu5Ac (1U), AMP-Neu5Ac (1A), and GMP-Neu5Ac (1G).

Cytidine Monophosphate N-Acetylneuraminic Acid↗
PubMed1994

Magnetic resonance assessment of age-related development of the sphenoid sinus.

Magnetic resonance images of the sphenoid sinus in 401 patients under 15 years old were reviewed to establish normal age-related standards. T1-weighted sagittal and T2-weighted axial scans were evaluated for bone marrow conversion, development of pneumatization, spatial enlargement and septation of the sphenoid sinus. The sphenoid sinus had a uniformly low signal intensity (red bone marrow) on T1-weighted images in all children less than 4 months old. Signal intensity changes from hypointense to hyperintense (bone marrow conversion) started at the age of 4 months. Onset of pneumatization was observed in 12% of the patients at age 13-15 months. By age 43-48 months, 85% of the patients showed pneumatization of the anterior part of the sphenoid bone. Pneumatization was complete in all patients older than 10 years. Enlargement of the sinus showed a characteristic profile in each dimension. Median septation was observed irregularly with age, with a maximum of 77%. Septum variants were noticed between 4.5% and 20%. Because paediatric sinus disease is a challenging problem in children, these results may be useful as baseline standards of normal age-related development of the sphenoid sinus during childhood.

Adolescent↗
PubMed1993

[Haller's cells: morphologic evaluation and clinico-surgical relevance].

Ethmoidal cells that have developed into the floor of the orbit or into the roof of the maxillary sinus, respectively, are known as Haller's cells. 528 patients, in whom functional endoscopic sinus surgery was performed, were explored regarding the presence of Haller's cells. 43 patients presented with Haller's cells at least on one side (8.14%). CT scans of these patients were evaluated morphometrically measuring the dimensions of the Haller's cells as well as of the maxillary sinus. Further anatomical variations of the paranasal sinuses (concha bullosa, supraorbital cell, agger nasi cell) and the keros type of the ethmoid sinus roof were seen. A highly significant difference could be demonstrated between the incidence of Haller's cells in men (4.9%) and women (11.9%). For the first time it was possible to demonstrate a frequency distribution between Haller's cells deriving from the anterior ethmoidal cells (88%) and those originating from the posterior ethmoidal cells (12%). In 56% Haller's cells were opacified on CT-scan showing a mucosal swelling respectively a retention of secretion during endoscopic surgery.

Adolescent↗
PubMed1991

Combined resting-postural tremor of the head with a changing axis.

When essential tremor involves the head, it produces a rhythmic, periodic movement with a certain fixed frequency and a variable amplitude. The axis of the tremor has been described as either horizontal (no-no) or vertical (yes-yes) and is present when the head is in an action or postural position. Seven patients who differ in symptoms are described; one subgroup exhibited a combined resting-postural tremor of the head, sometimes with a changing axis; three patients had only postural head tremor with a changing axis.

Aged↗
PubMed1991

Antihypertensive monotherapy with nitrendipine in general practice.

Efficacy and tolerability of antihypertensive monotherapy with the calcium antagonist nitrendipine were investigated in a 6-month open trial in 495 patients with mild to moderate essential hypertension from 101 practicing internists and general practitioners. Previous antihypertensive therapy (57.4%) was stopped for 1 week and therapy then started with nitrendipine, 20 mg once daily. Sixty-one patients discontinued therapy prematurely because of unwanted effects, mostly characteristic with dihydropyridines (headaches, flushing, and ankle edema), and 23 patients because of insufficient efficacy. In 75% of the remaining 411 patients, the goal blood pressure was achieved by nitrendipine monotherapy (10 mg in 17.6%, 20 mg in 73.3%, and 20 mg b.i.d. in 8%) and diastolic blood pressure was between 90 and 95 mm Hg in another 6%. The reduction in blood pressure did not result in changes of heart rate or weight. Nitrendipine was effective in patients of all age groups but patients older than 60 years of age showed a significantly greater fall in systolic pressure than middle-aged or young patients. At the end of the study, 15 patients still reported side effects. Nitrendipine appears to be well suited for first-line therapy of mild to moderate essential hypertension.

Adult↗
PubMed1989

A mobile traction device for MR and CT imaging.

The development of a spinal traction device for use in Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) imaging is described. Such a device has arisen from the need to apply continuous traction to patients having suffered acute cervical spine trauma. Previous traction techniques have proven unsuitable for use in the MRI scanner, particularly as they lack stability, are awkward to implement and prove quite cumbersome to manage. Traction may be applied to a patient for periods of time in excess of 1 hour with a minimum of discomfort. Materials are used which have a negligible proton density and a low atomic number, yielding no detectable magnetic resonance and very small x-ray cross sections respectively. Calibrated traction may be applied to patients via tongs or a head harness, the latter rendering the device suitable for general transport of injured patients with traction applied. The device is compact, light and strong and contains no ferrometallic parts. Thus far in excess of 40 patients have been scanned, most in a FONAR beta-3000M .3 Tesla electromagnetic MR imager and some also in a GE 9800 Quickscan CT scanner. No artefact has been demonstrated in any of the images to date for any of the MR pulse sequences or CT kVp. Modifications likely include refinement of the tensioning mechanism, inclusion of x-ray cassette facilities and improvement of aesthetic design.

Equipment Design↗