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Biomedical subjects

R Graf

Publications and source records attributed to R Graf.

At least 217 records · Page 12Linked to original sources
PubMed1987

[Does the IIa hip need treatment? Results of a longitudinal study of sonographically controlled hips of infants less than 3 months of age].

In a randomized retrospective study we followed hips classified as Type II a by ultrasound. The classification as "Type IIa" only was found inadequate. It is important to further differentiate the so-called physiologically immature hip, namely to distinguish between joints that, while immature, are appropriate for age [Type IIa(+)], and those hips with a maturation deficit exceeding a tolerable degree [Type IIa(-)]. The follow-up showed that hips classified as Type IIa(-) and treated before the age of 6 weeks had a clearly better healing result than the hips treated only after the sixth week. Thus, to achieve optimal healing and to keep to a minimum the dysplasias requiring treatment after 3 months' age, an ultrasound study of the hip should be done as early as possible. The total percentage of ultrasonically recognized abnormal joints requiring treatment (independently of the patient's age) was 6.6%. This corresponds to the regional average before the advent of ultrasound. However, because of extensive very early screening in our area, we found not a single hip dislocation later then at the age of 10 weeks during the last 2 years.

Hip Dislocation, Congenital↗
PubMed1987

[Replacement of the head of the humerus as a rescue operation following dislocated compound fractures of the shoulder joint].

Results after conservative or surgical treatment of comminuted fractures of the head of the humerus are often unsatisfactory and complicated by pain and a severely decreased range of motion. In these patients good results have been obtained by replacement of the humeral head with the Isoelastic Humeral Head Prosthesis. Fourteen cases are reported and their results discussed.

Adult↗
PubMed1986

Mosquito trypsin: immunocytochemical localization in the midgut of blood-fed Aedes aegypti (L.).

A polyclonal antibody was raised against trypsin purified from the midgut of blood-fed Aedes aegypti. Using this antibody and our modification of the peroxidase-antiperoxidase immunocytochemical reaction, strong activity was found in the lumen of the midgut at the light-microscopical level. The activity was localized mainly in the posterior part of the distensible, abdominal midgut, along the periphery of the blood bolus and within the peritrophic membrane. Immunoreactivity appeared 8 h after the blood meal and was most prominent around 24 h, coinciding with our previous spectrophotometric determinations of trypsin. At the electron-microscopical level, secretory granules, immunocytochemically labelled with anti-trypsin antibody and protein A-colloidal gold, were first detected about 12 h after the blood meal. At 18 h, the secretory pathway could be followed immunocytochemically from the formation of granules in the Golgi complex until their release by exocytosis in the midgut lumen. By 24 h, there was a reduction in secretory granules, and large lysosomes appeared. The process of secretion described for this mosquito is comparable to similar events in vertebrate secretory systems and the presence of an intracellular trypsinogen is suggested.

Aedes↗
PubMed1986

Protease cytochemistry in the murine rodent, guinea-pig and marmoset placenta.

Plasma membrane and lysosomal proteases, gamma-glutamyl transferase and extracellular matrix proteases were investigated by qualitative cytochemical means in the mature placenta of mice, rats, guinea-pigs and marmosets. These studies revealed similarities, which concerned primarily the lysosomal proteases in different structures of the placenta and all proteases and gamma-glutamyl transferases in the zone of placental shedding. However, species differences predominated. They were observed especially for amino-peptidase A and M, dipeptidyl peptidase IV and gamma-glutamyl transferase in the plasma membranes and extracellular matrix of the placental barrier and decidual cells of all species and the cells of the basal zone in rats and mice. Plasma membrane and extracellular matrix proteases in other parts of the placenta, e.g. the placenta stem of guinea-pigs and basal plate, amniotic and chorionic plate of marmosets occurred only in these species. Elastase substrates hydrolysing endopeptidase I and kallikrein-, thrombin-, plasmin-, plasminogen- and cathepsin B substrates hydrolysing endopeptidase II were not observed in any of these species. A general comparison of the species revealed similarities for the mouse, rat and guinea-pig placental barrier, but not for that of marmosets. The proteases of this zone in the marmoset placenta are more similar to the human situation, but do not correspond to it completely.

Animals↗
PubMed1986

Comparative hydrolase cytochemistry of the mature guinea-pig and marmoset yolk sac with special reference to proteases.

Proteases and gamma-glutamyl transferase linked to plasma membranes, lysosomes and secretion granules were investigated cytochemically together with phosphatases, glycosidases and non-specific esterases in the mature guinea-pig and marmoset yolk sac. Species-independently, the yolk sac epithelial cells showed high activities of lysosomal proteases, glycosidases and non-specific esterases and phosphatases, whereas species-dependent patterns were found for plasma membrane proteases, gamma-glutamyl transferase and phosphatases. Furthermore, the guinea-pig yolk sac epithelium showed marked regional differences and that of both species intercellular differences, which allowed the subdivision of yolk sac epithelial cells in various types. The high activities of all lysosomal enzymes suggests their general importance for the yolk sac function in guinea-pigs and marmosets. The different equipment of the plasma membrane with proteases, gamma-glutamyl transferase and phosphatases indicates a more species-specific physiological role of this part of the yolk sac epithelial cells.

Aging↗
PubMed1986

Cortical deafferentation in cat focal ischemia: disturbance and recovery of sensory functions in cortical areas with different degrees of cerebral blood flow reduction.

During and after 15-min occlusion of the middle cerebral artery (MCA) in cats, local CBF and neuronal activity were measured in cortical areas varying in the degree of CBF reduction. In an area within the ischemic center (primary auditory cortex, middle ectosylvian gyrus), CBF was severely suppressed. Click-induced auditory evoked potentials and evoked as well as spontaneous single-unit activity ceased within 1 min after occlusion. Recirculation resulted in a recovery of the different neurophysiological parameters with a time delay ranging from several minutes to 2 h. In two areas surrounding the ischemic focus (a visual area in the marginal gyrus and the forelimb representation area in the primary somatosensory cortex), CBF was reduced but remained above 30 ml/100 g/min during MCA occlusion. Visual flash-induced evoked potentials and somatosensory evoked potentials induced by median nerve electrical stimulation ceased in the corresponding areas with a somewhat slower time course as compared to the auditory responses and they recovered faster after recirculation. In another somatosensory area (hindlimb projection area in the primary somatosensory cortex), CBF stayed nearly at control levels during occlusion. Evoked potentials and single-unit activity induced by tibial nerve electrical stimulation decreased approximately 5 min after occlusion and were abolished approximately 5 min later. At that time, single-unit activity had changed to a nonresponsive pattern but persisted. However, potentials evoked transcallosally by electrical stimulation of the contralateral hemisphere were still recorded. After reopening the MCA, the recovery of neuronal functions was usually complete and occurred within approximately 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Rapid development of coronary arterial stenosis following valve replacement: an unusual cause of myocardial ischemia.

A 56-year-old woman had unstable angina pectoris 3 months after aortic and mitral valve replacement for rheumatic heart disease. Repeat coronary arteriography revealed critical proximal left anterior descending and circumflex artery stenoses in previously normal coronary arteries. This case emphasizes the need for thorough evaluation of postoperative valvular patients, despite normal preoperative coronary arteriograms.

Journal Article↗
PubMed1985

[Sonographically monitored hip dysplasia].

A report is presented of the possibilities that sonography offers in the investigation of the hip joint in newborn babies and infants. On the basis of experience gained over the past 6 years in the investigation of over 5000 infant hips, it is possible to produce an exact classification of disorders of hip maturation. Sonography renders possible the early recognition of hip maturation disorders, selection of optimal form of treatment and control of the adopted therapy. Sonography is, therefore, not limited to a mere depiction of the hip joint, but renders possible direct control of the therapeutic procedure. However, an introduction to the examination and measurement technique is indispensable.

Child Development↗
PubMed1985

Enzyme cytochemistry combined with electron microscopy, pharmacokinetics, and clinical chemistry for the evaluation of the effects of steady-state valproic acid concentrations on the mouse.

A number of organs from adult female mice were investigated after continuous application of the anticonvulsant drug valproic acid (VPA) by enzyme cytochemistry, light and electron microscopy, pharmacokinetics and clinical chemistry. VPA plasma levels were maintained between 55 micrograms/ml and 67 micrograms/ml for three days following subcutaneous implantation of drug reservoirs. Effects detectable by enzyme cytochemical or electron microscopical means were mainly observed in liver, kidney, thymus and spleen. A strict concentration-dependency of drug effects could not be found. In the liver, the activities of some surface-membrane hydrolases were increased at the biliary pole; the activities of other hydrolases were decreased or unchanged. Electron microscopically, number and length of microvilli of hepatocytes were increased and many of them showed fat inclusions, mitochondrial swellings and autophagic vacuoles. In some of the proximal convoluted tubules of the kidney, the reaction product originating from microvillous and lysosomal hydrolases was diffusely distributed and its amount lowered. This was paralleled by tubular cells with an increased number of fat droplets and swollen mitochondria or destroyed tubular cells, as demonstrated by electron microscopy. Additionally, peritubular endothelial cells were arranged in a garland-like pattern. Alkaline phosphatase was activated in the straight portion of the proximal tubules. Increased glucose, creatinine and total protein concentrations and increased gamma-glutamyl transpeptidase and alkaline phosphatase activities in the urine reflected well the damage of the proximal renal tubules. Cortical and medullary morphology varied considerably in the thymus. In extreme cases, the cortical zone was either reduced in size or the medulla showed a cortex-like structure or vice versa (inverted type of thymus). The thymic cortical reticular cells showed increased aminopeptidase A activity accompanied by a generalized aminopeptidase M and alkaline phosphatase reaction. Our data indicate that--in addition to the liver--also the kidney, thymus and spleen are target organs of VPA-induced toxicity in the mouse.

Alkaline Phosphatase↗
PubMed1985

[Possibilities, problems and present status of hip sonography of infant hips].

The author reports on hip-joint examinations in 16 000 infants, using sonography (age: 1 day up to 12-15 months). Particular attention is given to the classification of disturbances of maturation of the hip joint described. The use of angles and the possibility of making mistakes during measurement are demonstrated. The ultrasonographic traces are compared with X-rays to demonstrate the accuracy of ultrasonic investigation of infant hip joints. Determination of hip-joint maturity using the "sonometer" is described.

Hip Dislocation, Congenital↗
PubMed1984

Classification of hip joint dysplasia by means of sonography.

Our report relates to our experimental investigations and clinical experience gained with the sonography of infant hips. On the basis of over 3,000 sonograms we were able to carry out a standardization of dysplasia forms from the sonographic point of view. It is possible to recognize disturbed hip maturation already after birth and to continuously control the further development. New sonographic findings and details permit to take up a more differentiated therapy as applied so far.

Hip Dislocation, Congenital↗
PubMed1984

[Lumbar intervertebral disk prolapse in adolescence. I. Clinical observations].

Twenty-five cases of intervertebral disc herniation in young people between 15 and 25 years old are reported. They have been operated in the Neurosurgical Clinic of Basle between July 1978 and July 1982. The clinical and radiological findings, the operative procedure and the results are described. The postoperative courses were generally more complicated in the young than in a comparative group of elder patients. The importance of strict, restrictive indications for this operation is pointed out.

Adolescent↗