Search PubMed⌕ Search

Biomedical subjects

H Winter

Publications and source records attributed to H Winter.

At least 163 records · Page 9Linked to original sources
PubMed1987

Assessment of contractility changes in humans by transoesophageal echocardiography: the peak-systolic pressure end-systolic diameter relationship (PSPESDRS).

The peak-systolic pressure end-systolic diameter relationship (PSPESDRS) was determined in ten healthy subjects under general anaesthesia by using the radial artery pressure tracing (peak-systolic pressure) and transoesophageal 2d-and m-mode echocardiography (left ventricular diameters) without blocking of autonomic reflexes. Left ventricular load was changed by injection of a single intravenous dose of 0.2 mg nitroglycerin (NTG). Linear regression analysis showed a close linear relationship during the pressure decrease between peak-systolic pressures and end-systolic diameters. During infusion of dobutamine 5 micrograms/kg/min there was also a close linear relationship during pressure decrease with increased slope and unchanged Do (D0 = diameter at theoretical pressure zero). Values taken during pressure returning to control level were shifted leftward indicating transient increased contractility. We conclude, that the PSPESDRS can reliably be measured in humans without autonomic blockade during the decrease of arterial pressure after NTG, where reflex changes in inotropy are not yet present. This relationship increases in slope with dobutamine, reflecting the increased contractile state.

Blood Pressure↗
PubMed1987

Selective suppression of two postnatally acquired 70 kD and 65 kD keratin proteins during continuous treatment of adult mouse tail epidermis with vitamin A.

Using mouse tail epidermis as a model system we have studied the morphologic and biochemical effects of continuous topical treatment with vitamin A acid. Normal tail epidermis shows a regular pattern of parakeratotic scale regions and orthokeratotic interscale regions which arise postnatally from a uniformly orthokeratinizing neonatal epidermis. Daily treatment of tail epidermis with vitamin A acid for 14 days results in the induction of hyperplasia and the orthokeratotic conversion of the scale regions. The degree of these alterations is dose-dependent and maximally brought about by repetitive 30-microgram doses of the vitamin. To correlate morphologic with biochemical alterations, we have analyzed the keratin patterns of normal and vitamin A acid-treated epidermis by one- and two-dimensional gel electrophoresis. The results indicate that repetitive vitamin A treatment leads to the selective suppression of two postnatally acquired 70 kD and 65 kD type II keratin proteins. Again the minimum repetitive dose required for their complete suppression is 30 micrograms vitamin A acid. Kinetic studies reveal an initial lag phase of 6 days of apparent nonresponsiveness, followed by a 5-day period during which the adult pattern is gradually replaced by the neonatal pattern. Repetitive treatment of tail epidermis with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate leads to a strong hyperplasia; however, it strictly maintains the scale parakeratosis. Under these conditions only the 70 kD keratin subunit is suppressed. This indicates that the suppression of the 70 kD keratin is generally linked to the induction of hyperproliferation, whereas the suppression of the scale-associated 65 kD subunit is due to the metaplastic potency of vitamin A. We provide evidence that this vitamin A-specific in vivo effect can be used to determine the biologic activity of synthetic retinoids relative to vitamin A acid.

Animals↗
PubMed1987

An unusual type-II 70-kilodalton keratin protein of mouse epidermis exhibiting postnatal body-site specificity and sensitivity to hyperproliferation.

Keratin extracts from the epidermis of adult mouse ears, footpads, and tail contain large amounts of a 70-kilodalton (kDa) protein which has not been detected in any other body site of the adult mouse or in the epidermis of neonatal mice. Two-dimensional immunoblotting using an antiserum which recognizes both type-I and type-II murine keratins revealed that the 70-kDa protein is indeed a keratin belonging to the type-II subfamily. Its postnatal induction occurs during the first 2 weeks after birth, being first observed in tail epidermis, then in footpad epidermis, and only rather late in ear epidermis. Although in vitro translation experiments with polyA+-RNA from adult tail and footpad epidermis consistently failed to reveal the 70-kDa protein among the translation products, we obtained evidence using a specific cDNA clone that, in vivo, the protein is encoded by a discrete mRNA. This clone, termed pke70, was isolated from a cDNA library of footpad epidermal mRNA. Homology comparisons with a variety of known keratin cDNAs indicated that pke70 contains sequence information for a type-II keratin that is substantially larger than the mouse 67-kDa keratin protein. Northern-blot analysis with a specific 3'-fragment of pke70 demonstrated a single 2.8 +/- 0.1 kb mRNA species exclusively in adult ear, footpad, and tail epidermis. In situ hybridization with the same fragment revealed the presence of the pke70-hybridizing mRNA in both basal and suprabasal cells of ear and footpad epidermis as well as in the orthokeratinizing parts of the tail epidermis; however in the epidermis covering the balls of the feet, labeling was restricted to suprabasal cells at the base of these nodular elevations. Continuous treatment of adult tail or ear epidermis with hyperplasiogenic agents, e.g., vitamin A acid and the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), leads to a gradual disappearance of the 70-kDa protein. We obtained evidence using in situ hybridization that the loss of the 70-kDa keratin is preceded by a specific suppression of the transcription of its putative mRNA in basal cells, whereas initially suprabasal cells are apparently still able to complete their original commitment. The particular properties of the 70-kDa keratin protein, i.e., its topological restriction, its postnatal and time-dependent acquisition, and its pronounced sensitivity to hyperplasiogenic stimuli, make this keratin subunit an especially suitable candidate for studies concerning the regulation of keratin expression and morphogenesis in general, as well as for studies of the factors that control its expression so specifically.

Amino Acid Sequence↗
PubMed1986

Nonepidermal members of the keratin multigene family: cDNA sequences and in situ localization of the mRNAs.

A keratin set which consists of a type I 47kd and a type II 57kd protein occurs as a major constituent of the keratin patterns of various internal stratified epithelia of the mouse. We have isolated specific cDNA clones of the two complementary keratin subunits from a cDNA library constructed with polyA+RNA of mouse tongue epithelium and present the complete nucleotide and deduced amino acid sequences of the 57kd protein and about 75% of the corresponding data of the 47kd protein. The comparison of the sequence data with those of known epidermal keratin mRNAs coding for the two types of keratin proteins reveals a fundamentally identical and type-specific organization of the mRNAs into both highly conserved and variable domains. In order to avoid cross-reactions with other members of the keratin multigene family, appropriately taylored 35S-labeled cDNA probes comprising the low and non-homologous 3' coding and noncoding domains of the mRNAs were used for in situ hybridization to tissue sections. The localization and distribution of the corresponding transcripts indicates a strongly compartmentalized keratin expression in mouse tongue epithelium.

Amino Acid Sequence↗
PubMed1986

Aminoalkylsilane-treated glass slides as support for in situ hybridization of keratin cDNAs to frozen tissue sections under varying fixation and pretreatment conditions.

Attempts to investigate the cellular localization of keratin mRNAs by in situ hybridization with specific [35S]-labelled cDNA probes to mouse epithelia have been seriously impeded by the uncontrollable detachment of frozen tissue sections on conventionally coated glass slides (i.e. those coated with egg white, gelatin, collagen). Similarly, a variety of other coating and attachment devices have proved to be unsatisfactory or impracticable for large scale investigations. These difficulties were completely overcome and in situ hybridization was possible after a short immersion of the glass slides in a 2% solution of 3-aminopropyltriethoxysilane in acetone. This treatment provides the glass surface with aminoalkyl groups which are apparently able to react covalently with aldehyde or ketone functions of frozen tissue sections. The resulting firm adhesion of the sections enabled us to investigate the influence of different fixation and prehybridization procedures on the quality of the in situ hybridization. It was found that especially harsh prehybridization, involving hydrochloric acid, heat and proteinase K treatment, drastically reduces the morphological integrity of the sections, thus rendering a reliable assignment of the label difficult. In contrast, a mild prehybridization, consisting mainly of a rehydration of the sections in phosphate-buffered saline and equilibration in 0.1 M glycine, leaves the morphology intact and leads to a highly efficient and specific in situ hybridization.

Animals↗
PubMed1986

Differential localization of distinct keratin mRNA-species in mouse tongue epithelium by in situ hybridization with specific cDNA probes.

The tongue of the adult mouse is covered by a multilayered squamous epithelium which is continuous on the ventral surface, however interrupted on the dorsal surface by many filiform and few fungiform papillae. The filiform papillae themselves are subdivided into an anterior and posterior unit exhibiting different forms of keratinization. Thus, the entire epithelium shows a pronounced morphological diversity of well recognizable tissue units. We have used a highly sensitive in situ hybridization technique to investigate the differential expression of keratin mRNAs in the tongue epithelium. The hybridization probes used were cDNA restriction fragments complementary to the most specific 3'-regions of any given keratin mRNA. We could show that independent of the morphologically different tongue regions, all basal cells uniformly express the mRNA of a type I 52-kD keratin, typical also for basal cells of the epidermis. Immediately above the homogenous basal layer a vertically oriented specialization of the keratin expression occurs within the morphological tissue units. Thus the dorsal interpapillary and ventral epithelium express the mRNAs of a type II 57-kD and a type I 47-kD keratin pair. In contrast, in the anterior unit of the filiform papillae, only the 47-kD mRNA is present, indicating that this keratin may be coexpressed in tongue epithelium with different type II partners. In suprabasal cells of both, the fungiform papillae and the posterior unit of the filiform papillae, a mRNA of a type I 59-kD keratin could be detected; however, its type II 67-kD epidermal counterpart seems not to be present in these cells. Most surprisingly, in distinct cells of both types of papillae, a type I 50-kD keratin mRNA could be localized which usually is associated with epidermal hyperproliferation. In conclusion, the in situ hybridization technique applied has been proved to be a powerful method for detailed studies of differentiation processes, especially in morphologically complex epithelia.

Animals↗
PubMed1986

Genetic characterisation of the mithun (Bos frontalis) and studies of spermatogenesis, blood groups and haemoglobins of its hybrids with Bos indicus.

The mithun (Bos frontalis) and its hybrids with Bos indicus were studied to provide further cytogenetic information which might throw light on the mechanisms of the male hybrid infertility and facilitate the establishment of a stable crossbreed. It was shown that compared with conventional cattle the mithun has a homozygous, species specific 2/27 centric fusion which reduced the diploid chromosome number from 60 to 58. This provided further proof that Robertson translocation-type rearrangements have been the major source of interspecies karyotype differences in the evolution of the Bovidae. In the mithun there was also significant polymorphism between centromeres of non-homologous chromosomes and there was heteromorphism between several homologous chromosomes which could possibly serve as useful genetic markers for breeding programmes. In F1 hybrids spermatogenesis progressed to a relatively advanced stage, without going so far as to produce spermatozoa. In back crosses to B indicus spermatogenesis progressed further so that spermatozoa could be seen, though not as numerous as in normal bulls. In most hybrids there were haemoglobin bands which corresponded either to Hb A or Hb B of cattle but were much wider. It was shown that these were a combination of Hb Mi derived from the mithun and Hb A or Hb B derived from B indicus. In a few hybrids there were only Hb Mi. In these cases Hb Mi had been present in both parents and proved that the dam was not a pure siri. The possible mechanism of hybrid male infertility is discussed including faults in the epistatic gene effect between chromosomes and changes in the degree of association of centromeric regions in interspecies hybrids. It is suggested that additional cytogenetic examination of blood lymphocytes and especially of testicles would help the understanding of the fertility barriers of hybrid males and would make a breeding programme for a stable crossbreed possible.

Animals↗
PubMed1986

[Comparative echocardiographic studies on the negative inotropic effect of halothane, enflurane and isoflurane].

Using the afterload-independent end-systolic pressure-dimension-relationship a study was performed in order to investigate whether there are differences in the negative inotropic effects of halothane, enflurane and isoflurane at 1 MAC in 70% N2O. 30 patients of ASA-groups I and II were studied. Using transoesophageal 2d- and m-mode echocardiography the end-systolic-pressure-dimension-relationship was established and the slope (parameter of contractility) determined. The slope decreased significantly (paired Wilcoxon-test 2 alpha less than 0.01) with halothane (68.5/46.5 mmHg/cm), enflurane (56/48 mm Hg/cm) and isoflurane (63/35 mmHg/cm). There is no difference between the three groups (Kruskal-Wallis-test 2 alpha greater than 0.05). The negative inotropic effects of halothane, enflurane and isoflurane at 1 MAC in 70% N2O are the same. The vasodilation caused by isoflurane enables better pump function compared to halothane and enflurane, but may cause severe hypotension. We conclude that for cardiac risk patients isoflurane has no outstanding advantages in comparison to halothane and enflurane.

Adult↗
PubMed1985

Scintigraphy of lymphatic vessels in malignant melanoma of the skin before operation (en bloc excision).

An injection of 99mTc-labelled antimony sulphide colloid was used to show the lymphatic pathways in patients with malignant melanoma of the trunk skin. Using a gamma camera, optimal visualisation was obtained 15-30 min postinjection. Surprising deviations of the lymphatic pathways were found; therefore, this method makes it possible to plan continuity dissection appropriate to individual cases. Two examples are presented.

Antimony↗
PubMed1985

[Expert testimony on rotator cuff rupture].

In giving an expert opinion, it is difficult to differentiate between the two possible causes of damage of the rotator cup, degeneration and trauma. After description of the anatomical problems, different causes for degenerative changes, especially of the supraspinatus tendon, are discussed. Various possibilities of accidents are analysed if they can cause damage of the rotator cup. The special conditions of the private accident insurance are discussed.

Accidents↗
PubMed1985

[Transesophageal 2-dimensional echocardiography in hip endoprostheses].

Previous studies indicate that during total hip replacement intraoperative pulmonary embolization of air and medullary bone marrow occurs. This was based on histological examination of lung tissue obtained during animal investigations and postmortem in human tissue. In vivo proof of this embolization has not as yet been found because of the methodological problems involved. Using transoesophageal two-dimensional echocardiography continuously direct imaging of the right atrium and the right ventricle can be carried out and the embolization thus visualized. In a prospective randomized study in 26 patients having to undergo total hip replacement operation the right atrium and right ventricle were continuously scanned. Endexpiratory CO2-partial pressure was simultaneously recorded. A venting hole in the femur is said to prevent the pressure rising in the medullary space and therefore prevents embolization. In 13 patients therefore, a 4.5 mm lateral drill hole 4 cm distal the tip of the prosthesis was made in order to vent the medullary space. Transoesophageal two-dimensional echocardiography revealed air bubbles in 12 of 13 patients in the control group during implantation of the femoral prosthesis. This is significantly different to the group of vented patients where bubbles were only seen in 4 cases (p less than 0.01). Emboli were visible in 8 patients in the control group in contrast to only 2 cases in the vented group (p less than 0.05). The endexpiratory CO2-pressure of the control group fell from 35 mmHg to 33 mm Hg (Median, p less than 0.001). The CO2 of the vented patients remained constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Characterization of gamma-linolenic acid in Ribes seed.

The total lipid content of fruit seeds of the Ribes family ranges by weight from 18.3% in goose-berries (Ribes uva crispa) to 30.5% in black currants (Ribes nigrum). Isolation procedures and analytical methods (gas chromatography, mass spectrometry, high performance thin layer chromatography and stereospecific analysis) demonstrate that the oils from Ribes seeds contain up to 19% by weight of gamma-linolenic acid (gamma-LA, C18:3, n-6) in black currant oil. This last Ribes species thus constitutes one of the richest natural sources in gamma-LA yet described. These oils appear promising for critically ill patients who seem unable to convert linoleic acid into subsequent EFA fractions.

Chromatography, Gas↗
PubMed1984

Sequential expression of mRNA-encoded keratin sets in neonatal mouse epidermis: basal cells with properties of terminally differentiating cells.

The keratin pattern of newborn mouse epidermis was investigated during terminal differentiation. In highly pure fractions of basal and suprabasal cells, obtained by Percoll density gradient centrifugation, we identified two sets of mRNA-encoded proteins: a basal set of 58.5, 52, and 47 kd subunits and a suprabasal set of 67 and 60 kd subunits. The large subunits of each set were alkaline to neutral, while the small subunits were acidic. Polyclonal antibodies against the suprabasal, acidic 60 kd protein and the basal, alkaline 58.5 kd protein selectively recognized their antigens in immunoblots of NEPHGE -resolved keratins and decorated the corresponding epidermal compartments in frozen sections. The antibody to the suprabasal 60 kd protein also recognized distinct cells in the basal cell layer. Quantification of this cell population revealed a 10% cell fraction, morphologically indistinguishable from the total cell population, that, in addition to expressing basal keratin proteins, was already synthesizing suprabasal keratin subunits.

Animals↗